Commit ada9c93312f7ec49514c68c211595ce2601cebae
Committed by
Linus Torvalds
1 parent
60b8b1de0d
Exists in
master
and in
39 other branches
signal.c: fix kernel-doc notation
Fix kernel-doc warnings in signal.c: Warning(kernel/signal.c:2374): No description found for parameter 'nset' Warning(kernel/signal.c:2374): Excess function parameter 'set' description in 'sys_rt_sigprocmask' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 1 changed file with 1 additions and 1 deletions Inline Diff
kernel/signal.c
1 | /* | 1 | /* |
2 | * linux/kernel/signal.c | 2 | * linux/kernel/signal.c |
3 | * | 3 | * |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | 4 | * Copyright (C) 1991, 1992 Linus Torvalds |
5 | * | 5 | * |
6 | * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson | 6 | * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson |
7 | * | 7 | * |
8 | * 2003-06-02 Jim Houston - Concurrent Computer Corp. | 8 | * 2003-06-02 Jim Houston - Concurrent Computer Corp. |
9 | * Changes to use preallocated sigqueue structures | 9 | * Changes to use preallocated sigqueue structures |
10 | * to allow signals to be sent reliably. | 10 | * to allow signals to be sent reliably. |
11 | */ | 11 | */ |
12 | 12 | ||
13 | #include <linux/slab.h> | 13 | #include <linux/slab.h> |
14 | #include <linux/module.h> | 14 | #include <linux/module.h> |
15 | #include <linux/init.h> | 15 | #include <linux/init.h> |
16 | #include <linux/sched.h> | 16 | #include <linux/sched.h> |
17 | #include <linux/fs.h> | 17 | #include <linux/fs.h> |
18 | #include <linux/tty.h> | 18 | #include <linux/tty.h> |
19 | #include <linux/binfmts.h> | 19 | #include <linux/binfmts.h> |
20 | #include <linux/security.h> | 20 | #include <linux/security.h> |
21 | #include <linux/syscalls.h> | 21 | #include <linux/syscalls.h> |
22 | #include <linux/ptrace.h> | 22 | #include <linux/ptrace.h> |
23 | #include <linux/signal.h> | 23 | #include <linux/signal.h> |
24 | #include <linux/signalfd.h> | 24 | #include <linux/signalfd.h> |
25 | #include <linux/ratelimit.h> | 25 | #include <linux/ratelimit.h> |
26 | #include <linux/tracehook.h> | 26 | #include <linux/tracehook.h> |
27 | #include <linux/capability.h> | 27 | #include <linux/capability.h> |
28 | #include <linux/freezer.h> | 28 | #include <linux/freezer.h> |
29 | #include <linux/pid_namespace.h> | 29 | #include <linux/pid_namespace.h> |
30 | #include <linux/nsproxy.h> | 30 | #include <linux/nsproxy.h> |
31 | #define CREATE_TRACE_POINTS | 31 | #define CREATE_TRACE_POINTS |
32 | #include <trace/events/signal.h> | 32 | #include <trace/events/signal.h> |
33 | 33 | ||
34 | #include <asm/param.h> | 34 | #include <asm/param.h> |
35 | #include <asm/uaccess.h> | 35 | #include <asm/uaccess.h> |
36 | #include <asm/unistd.h> | 36 | #include <asm/unistd.h> |
37 | #include <asm/siginfo.h> | 37 | #include <asm/siginfo.h> |
38 | #include "audit.h" /* audit_signal_info() */ | 38 | #include "audit.h" /* audit_signal_info() */ |
39 | 39 | ||
40 | /* | 40 | /* |
41 | * SLAB caches for signal bits. | 41 | * SLAB caches for signal bits. |
42 | */ | 42 | */ |
43 | 43 | ||
44 | static struct kmem_cache *sigqueue_cachep; | 44 | static struct kmem_cache *sigqueue_cachep; |
45 | 45 | ||
46 | int print_fatal_signals __read_mostly; | 46 | int print_fatal_signals __read_mostly; |
47 | 47 | ||
48 | static void __user *sig_handler(struct task_struct *t, int sig) | 48 | static void __user *sig_handler(struct task_struct *t, int sig) |
49 | { | 49 | { |
50 | return t->sighand->action[sig - 1].sa.sa_handler; | 50 | return t->sighand->action[sig - 1].sa.sa_handler; |
51 | } | 51 | } |
52 | 52 | ||
53 | static int sig_handler_ignored(void __user *handler, int sig) | 53 | static int sig_handler_ignored(void __user *handler, int sig) |
54 | { | 54 | { |
55 | /* Is it explicitly or implicitly ignored? */ | 55 | /* Is it explicitly or implicitly ignored? */ |
56 | return handler == SIG_IGN || | 56 | return handler == SIG_IGN || |
57 | (handler == SIG_DFL && sig_kernel_ignore(sig)); | 57 | (handler == SIG_DFL && sig_kernel_ignore(sig)); |
58 | } | 58 | } |
59 | 59 | ||
60 | static int sig_task_ignored(struct task_struct *t, int sig, | 60 | static int sig_task_ignored(struct task_struct *t, int sig, |
61 | int from_ancestor_ns) | 61 | int from_ancestor_ns) |
62 | { | 62 | { |
63 | void __user *handler; | 63 | void __user *handler; |
64 | 64 | ||
65 | handler = sig_handler(t, sig); | 65 | handler = sig_handler(t, sig); |
66 | 66 | ||
67 | if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && | 67 | if (unlikely(t->signal->flags & SIGNAL_UNKILLABLE) && |
68 | handler == SIG_DFL && !from_ancestor_ns) | 68 | handler == SIG_DFL && !from_ancestor_ns) |
69 | return 1; | 69 | return 1; |
70 | 70 | ||
71 | return sig_handler_ignored(handler, sig); | 71 | return sig_handler_ignored(handler, sig); |
72 | } | 72 | } |
73 | 73 | ||
74 | static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns) | 74 | static int sig_ignored(struct task_struct *t, int sig, int from_ancestor_ns) |
75 | { | 75 | { |
76 | /* | 76 | /* |
77 | * Blocked signals are never ignored, since the | 77 | * Blocked signals are never ignored, since the |
78 | * signal handler may change by the time it is | 78 | * signal handler may change by the time it is |
79 | * unblocked. | 79 | * unblocked. |
80 | */ | 80 | */ |
81 | if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) | 81 | if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig)) |
82 | return 0; | 82 | return 0; |
83 | 83 | ||
84 | if (!sig_task_ignored(t, sig, from_ancestor_ns)) | 84 | if (!sig_task_ignored(t, sig, from_ancestor_ns)) |
85 | return 0; | 85 | return 0; |
86 | 86 | ||
87 | /* | 87 | /* |
88 | * Tracers may want to know about even ignored signals. | 88 | * Tracers may want to know about even ignored signals. |
89 | */ | 89 | */ |
90 | return !tracehook_consider_ignored_signal(t, sig); | 90 | return !tracehook_consider_ignored_signal(t, sig); |
91 | } | 91 | } |
92 | 92 | ||
93 | /* | 93 | /* |
94 | * Re-calculate pending state from the set of locally pending | 94 | * Re-calculate pending state from the set of locally pending |
95 | * signals, globally pending signals, and blocked signals. | 95 | * signals, globally pending signals, and blocked signals. |
96 | */ | 96 | */ |
97 | static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) | 97 | static inline int has_pending_signals(sigset_t *signal, sigset_t *blocked) |
98 | { | 98 | { |
99 | unsigned long ready; | 99 | unsigned long ready; |
100 | long i; | 100 | long i; |
101 | 101 | ||
102 | switch (_NSIG_WORDS) { | 102 | switch (_NSIG_WORDS) { |
103 | default: | 103 | default: |
104 | for (i = _NSIG_WORDS, ready = 0; --i >= 0 ;) | 104 | for (i = _NSIG_WORDS, ready = 0; --i >= 0 ;) |
105 | ready |= signal->sig[i] &~ blocked->sig[i]; | 105 | ready |= signal->sig[i] &~ blocked->sig[i]; |
106 | break; | 106 | break; |
107 | 107 | ||
108 | case 4: ready = signal->sig[3] &~ blocked->sig[3]; | 108 | case 4: ready = signal->sig[3] &~ blocked->sig[3]; |
109 | ready |= signal->sig[2] &~ blocked->sig[2]; | 109 | ready |= signal->sig[2] &~ blocked->sig[2]; |
110 | ready |= signal->sig[1] &~ blocked->sig[1]; | 110 | ready |= signal->sig[1] &~ blocked->sig[1]; |
111 | ready |= signal->sig[0] &~ blocked->sig[0]; | 111 | ready |= signal->sig[0] &~ blocked->sig[0]; |
112 | break; | 112 | break; |
113 | 113 | ||
114 | case 2: ready = signal->sig[1] &~ blocked->sig[1]; | 114 | case 2: ready = signal->sig[1] &~ blocked->sig[1]; |
115 | ready |= signal->sig[0] &~ blocked->sig[0]; | 115 | ready |= signal->sig[0] &~ blocked->sig[0]; |
116 | break; | 116 | break; |
117 | 117 | ||
118 | case 1: ready = signal->sig[0] &~ blocked->sig[0]; | 118 | case 1: ready = signal->sig[0] &~ blocked->sig[0]; |
119 | } | 119 | } |
120 | return ready != 0; | 120 | return ready != 0; |
121 | } | 121 | } |
122 | 122 | ||
123 | #define PENDING(p,b) has_pending_signals(&(p)->signal, (b)) | 123 | #define PENDING(p,b) has_pending_signals(&(p)->signal, (b)) |
124 | 124 | ||
125 | static int recalc_sigpending_tsk(struct task_struct *t) | 125 | static int recalc_sigpending_tsk(struct task_struct *t) |
126 | { | 126 | { |
127 | if ((t->group_stop & GROUP_STOP_PENDING) || | 127 | if ((t->group_stop & GROUP_STOP_PENDING) || |
128 | PENDING(&t->pending, &t->blocked) || | 128 | PENDING(&t->pending, &t->blocked) || |
129 | PENDING(&t->signal->shared_pending, &t->blocked)) { | 129 | PENDING(&t->signal->shared_pending, &t->blocked)) { |
130 | set_tsk_thread_flag(t, TIF_SIGPENDING); | 130 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
131 | return 1; | 131 | return 1; |
132 | } | 132 | } |
133 | /* | 133 | /* |
134 | * We must never clear the flag in another thread, or in current | 134 | * We must never clear the flag in another thread, or in current |
135 | * when it's possible the current syscall is returning -ERESTART*. | 135 | * when it's possible the current syscall is returning -ERESTART*. |
136 | * So we don't clear it here, and only callers who know they should do. | 136 | * So we don't clear it here, and only callers who know they should do. |
137 | */ | 137 | */ |
138 | return 0; | 138 | return 0; |
139 | } | 139 | } |
140 | 140 | ||
141 | /* | 141 | /* |
142 | * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up. | 142 | * After recalculating TIF_SIGPENDING, we need to make sure the task wakes up. |
143 | * This is superfluous when called on current, the wakeup is a harmless no-op. | 143 | * This is superfluous when called on current, the wakeup is a harmless no-op. |
144 | */ | 144 | */ |
145 | void recalc_sigpending_and_wake(struct task_struct *t) | 145 | void recalc_sigpending_and_wake(struct task_struct *t) |
146 | { | 146 | { |
147 | if (recalc_sigpending_tsk(t)) | 147 | if (recalc_sigpending_tsk(t)) |
148 | signal_wake_up(t, 0); | 148 | signal_wake_up(t, 0); |
149 | } | 149 | } |
150 | 150 | ||
151 | void recalc_sigpending(void) | 151 | void recalc_sigpending(void) |
152 | { | 152 | { |
153 | if (unlikely(tracehook_force_sigpending())) | 153 | if (unlikely(tracehook_force_sigpending())) |
154 | set_thread_flag(TIF_SIGPENDING); | 154 | set_thread_flag(TIF_SIGPENDING); |
155 | else if (!recalc_sigpending_tsk(current) && !freezing(current)) | 155 | else if (!recalc_sigpending_tsk(current) && !freezing(current)) |
156 | clear_thread_flag(TIF_SIGPENDING); | 156 | clear_thread_flag(TIF_SIGPENDING); |
157 | 157 | ||
158 | } | 158 | } |
159 | 159 | ||
160 | /* Given the mask, find the first available signal that should be serviced. */ | 160 | /* Given the mask, find the first available signal that should be serviced. */ |
161 | 161 | ||
162 | #define SYNCHRONOUS_MASK \ | 162 | #define SYNCHRONOUS_MASK \ |
163 | (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \ | 163 | (sigmask(SIGSEGV) | sigmask(SIGBUS) | sigmask(SIGILL) | \ |
164 | sigmask(SIGTRAP) | sigmask(SIGFPE)) | 164 | sigmask(SIGTRAP) | sigmask(SIGFPE)) |
165 | 165 | ||
166 | int next_signal(struct sigpending *pending, sigset_t *mask) | 166 | int next_signal(struct sigpending *pending, sigset_t *mask) |
167 | { | 167 | { |
168 | unsigned long i, *s, *m, x; | 168 | unsigned long i, *s, *m, x; |
169 | int sig = 0; | 169 | int sig = 0; |
170 | 170 | ||
171 | s = pending->signal.sig; | 171 | s = pending->signal.sig; |
172 | m = mask->sig; | 172 | m = mask->sig; |
173 | 173 | ||
174 | /* | 174 | /* |
175 | * Handle the first word specially: it contains the | 175 | * Handle the first word specially: it contains the |
176 | * synchronous signals that need to be dequeued first. | 176 | * synchronous signals that need to be dequeued first. |
177 | */ | 177 | */ |
178 | x = *s &~ *m; | 178 | x = *s &~ *m; |
179 | if (x) { | 179 | if (x) { |
180 | if (x & SYNCHRONOUS_MASK) | 180 | if (x & SYNCHRONOUS_MASK) |
181 | x &= SYNCHRONOUS_MASK; | 181 | x &= SYNCHRONOUS_MASK; |
182 | sig = ffz(~x) + 1; | 182 | sig = ffz(~x) + 1; |
183 | return sig; | 183 | return sig; |
184 | } | 184 | } |
185 | 185 | ||
186 | switch (_NSIG_WORDS) { | 186 | switch (_NSIG_WORDS) { |
187 | default: | 187 | default: |
188 | for (i = 1; i < _NSIG_WORDS; ++i) { | 188 | for (i = 1; i < _NSIG_WORDS; ++i) { |
189 | x = *++s &~ *++m; | 189 | x = *++s &~ *++m; |
190 | if (!x) | 190 | if (!x) |
191 | continue; | 191 | continue; |
192 | sig = ffz(~x) + i*_NSIG_BPW + 1; | 192 | sig = ffz(~x) + i*_NSIG_BPW + 1; |
193 | break; | 193 | break; |
194 | } | 194 | } |
195 | break; | 195 | break; |
196 | 196 | ||
197 | case 2: | 197 | case 2: |
198 | x = s[1] &~ m[1]; | 198 | x = s[1] &~ m[1]; |
199 | if (!x) | 199 | if (!x) |
200 | break; | 200 | break; |
201 | sig = ffz(~x) + _NSIG_BPW + 1; | 201 | sig = ffz(~x) + _NSIG_BPW + 1; |
202 | break; | 202 | break; |
203 | 203 | ||
204 | case 1: | 204 | case 1: |
205 | /* Nothing to do */ | 205 | /* Nothing to do */ |
206 | break; | 206 | break; |
207 | } | 207 | } |
208 | 208 | ||
209 | return sig; | 209 | return sig; |
210 | } | 210 | } |
211 | 211 | ||
212 | static inline void print_dropped_signal(int sig) | 212 | static inline void print_dropped_signal(int sig) |
213 | { | 213 | { |
214 | static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10); | 214 | static DEFINE_RATELIMIT_STATE(ratelimit_state, 5 * HZ, 10); |
215 | 215 | ||
216 | if (!print_fatal_signals) | 216 | if (!print_fatal_signals) |
217 | return; | 217 | return; |
218 | 218 | ||
219 | if (!__ratelimit(&ratelimit_state)) | 219 | if (!__ratelimit(&ratelimit_state)) |
220 | return; | 220 | return; |
221 | 221 | ||
222 | printk(KERN_INFO "%s/%d: reached RLIMIT_SIGPENDING, dropped signal %d\n", | 222 | printk(KERN_INFO "%s/%d: reached RLIMIT_SIGPENDING, dropped signal %d\n", |
223 | current->comm, current->pid, sig); | 223 | current->comm, current->pid, sig); |
224 | } | 224 | } |
225 | 225 | ||
226 | /** | 226 | /** |
227 | * task_clear_group_stop_trapping - clear group stop trapping bit | 227 | * task_clear_group_stop_trapping - clear group stop trapping bit |
228 | * @task: target task | 228 | * @task: target task |
229 | * | 229 | * |
230 | * If GROUP_STOP_TRAPPING is set, a ptracer is waiting for us. Clear it | 230 | * If GROUP_STOP_TRAPPING is set, a ptracer is waiting for us. Clear it |
231 | * and wake up the ptracer. Note that we don't need any further locking. | 231 | * and wake up the ptracer. Note that we don't need any further locking. |
232 | * @task->siglock guarantees that @task->parent points to the ptracer. | 232 | * @task->siglock guarantees that @task->parent points to the ptracer. |
233 | * | 233 | * |
234 | * CONTEXT: | 234 | * CONTEXT: |
235 | * Must be called with @task->sighand->siglock held. | 235 | * Must be called with @task->sighand->siglock held. |
236 | */ | 236 | */ |
237 | static void task_clear_group_stop_trapping(struct task_struct *task) | 237 | static void task_clear_group_stop_trapping(struct task_struct *task) |
238 | { | 238 | { |
239 | if (unlikely(task->group_stop & GROUP_STOP_TRAPPING)) { | 239 | if (unlikely(task->group_stop & GROUP_STOP_TRAPPING)) { |
240 | task->group_stop &= ~GROUP_STOP_TRAPPING; | 240 | task->group_stop &= ~GROUP_STOP_TRAPPING; |
241 | __wake_up_sync_key(&task->parent->signal->wait_chldexit, | 241 | __wake_up_sync_key(&task->parent->signal->wait_chldexit, |
242 | TASK_UNINTERRUPTIBLE, 1, task); | 242 | TASK_UNINTERRUPTIBLE, 1, task); |
243 | } | 243 | } |
244 | } | 244 | } |
245 | 245 | ||
246 | /** | 246 | /** |
247 | * task_clear_group_stop_pending - clear pending group stop | 247 | * task_clear_group_stop_pending - clear pending group stop |
248 | * @task: target task | 248 | * @task: target task |
249 | * | 249 | * |
250 | * Clear group stop states for @task. | 250 | * Clear group stop states for @task. |
251 | * | 251 | * |
252 | * CONTEXT: | 252 | * CONTEXT: |
253 | * Must be called with @task->sighand->siglock held. | 253 | * Must be called with @task->sighand->siglock held. |
254 | */ | 254 | */ |
255 | void task_clear_group_stop_pending(struct task_struct *task) | 255 | void task_clear_group_stop_pending(struct task_struct *task) |
256 | { | 256 | { |
257 | task->group_stop &= ~(GROUP_STOP_PENDING | GROUP_STOP_CONSUME | | 257 | task->group_stop &= ~(GROUP_STOP_PENDING | GROUP_STOP_CONSUME | |
258 | GROUP_STOP_DEQUEUED); | 258 | GROUP_STOP_DEQUEUED); |
259 | } | 259 | } |
260 | 260 | ||
261 | /** | 261 | /** |
262 | * task_participate_group_stop - participate in a group stop | 262 | * task_participate_group_stop - participate in a group stop |
263 | * @task: task participating in a group stop | 263 | * @task: task participating in a group stop |
264 | * | 264 | * |
265 | * @task has GROUP_STOP_PENDING set and is participating in a group stop. | 265 | * @task has GROUP_STOP_PENDING set and is participating in a group stop. |
266 | * Group stop states are cleared and the group stop count is consumed if | 266 | * Group stop states are cleared and the group stop count is consumed if |
267 | * %GROUP_STOP_CONSUME was set. If the consumption completes the group | 267 | * %GROUP_STOP_CONSUME was set. If the consumption completes the group |
268 | * stop, the appropriate %SIGNAL_* flags are set. | 268 | * stop, the appropriate %SIGNAL_* flags are set. |
269 | * | 269 | * |
270 | * CONTEXT: | 270 | * CONTEXT: |
271 | * Must be called with @task->sighand->siglock held. | 271 | * Must be called with @task->sighand->siglock held. |
272 | * | 272 | * |
273 | * RETURNS: | 273 | * RETURNS: |
274 | * %true if group stop completion should be notified to the parent, %false | 274 | * %true if group stop completion should be notified to the parent, %false |
275 | * otherwise. | 275 | * otherwise. |
276 | */ | 276 | */ |
277 | static bool task_participate_group_stop(struct task_struct *task) | 277 | static bool task_participate_group_stop(struct task_struct *task) |
278 | { | 278 | { |
279 | struct signal_struct *sig = task->signal; | 279 | struct signal_struct *sig = task->signal; |
280 | bool consume = task->group_stop & GROUP_STOP_CONSUME; | 280 | bool consume = task->group_stop & GROUP_STOP_CONSUME; |
281 | 281 | ||
282 | WARN_ON_ONCE(!(task->group_stop & GROUP_STOP_PENDING)); | 282 | WARN_ON_ONCE(!(task->group_stop & GROUP_STOP_PENDING)); |
283 | 283 | ||
284 | task_clear_group_stop_pending(task); | 284 | task_clear_group_stop_pending(task); |
285 | 285 | ||
286 | if (!consume) | 286 | if (!consume) |
287 | return false; | 287 | return false; |
288 | 288 | ||
289 | if (!WARN_ON_ONCE(sig->group_stop_count == 0)) | 289 | if (!WARN_ON_ONCE(sig->group_stop_count == 0)) |
290 | sig->group_stop_count--; | 290 | sig->group_stop_count--; |
291 | 291 | ||
292 | /* | 292 | /* |
293 | * Tell the caller to notify completion iff we are entering into a | 293 | * Tell the caller to notify completion iff we are entering into a |
294 | * fresh group stop. Read comment in do_signal_stop() for details. | 294 | * fresh group stop. Read comment in do_signal_stop() for details. |
295 | */ | 295 | */ |
296 | if (!sig->group_stop_count && !(sig->flags & SIGNAL_STOP_STOPPED)) { | 296 | if (!sig->group_stop_count && !(sig->flags & SIGNAL_STOP_STOPPED)) { |
297 | sig->flags = SIGNAL_STOP_STOPPED; | 297 | sig->flags = SIGNAL_STOP_STOPPED; |
298 | return true; | 298 | return true; |
299 | } | 299 | } |
300 | return false; | 300 | return false; |
301 | } | 301 | } |
302 | 302 | ||
303 | /* | 303 | /* |
304 | * allocate a new signal queue record | 304 | * allocate a new signal queue record |
305 | * - this may be called without locks if and only if t == current, otherwise an | 305 | * - this may be called without locks if and only if t == current, otherwise an |
306 | * appropriate lock must be held to stop the target task from exiting | 306 | * appropriate lock must be held to stop the target task from exiting |
307 | */ | 307 | */ |
308 | static struct sigqueue * | 308 | static struct sigqueue * |
309 | __sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit) | 309 | __sigqueue_alloc(int sig, struct task_struct *t, gfp_t flags, int override_rlimit) |
310 | { | 310 | { |
311 | struct sigqueue *q = NULL; | 311 | struct sigqueue *q = NULL; |
312 | struct user_struct *user; | 312 | struct user_struct *user; |
313 | 313 | ||
314 | /* | 314 | /* |
315 | * Protect access to @t credentials. This can go away when all | 315 | * Protect access to @t credentials. This can go away when all |
316 | * callers hold rcu read lock. | 316 | * callers hold rcu read lock. |
317 | */ | 317 | */ |
318 | rcu_read_lock(); | 318 | rcu_read_lock(); |
319 | user = get_uid(__task_cred(t)->user); | 319 | user = get_uid(__task_cred(t)->user); |
320 | atomic_inc(&user->sigpending); | 320 | atomic_inc(&user->sigpending); |
321 | rcu_read_unlock(); | 321 | rcu_read_unlock(); |
322 | 322 | ||
323 | if (override_rlimit || | 323 | if (override_rlimit || |
324 | atomic_read(&user->sigpending) <= | 324 | atomic_read(&user->sigpending) <= |
325 | task_rlimit(t, RLIMIT_SIGPENDING)) { | 325 | task_rlimit(t, RLIMIT_SIGPENDING)) { |
326 | q = kmem_cache_alloc(sigqueue_cachep, flags); | 326 | q = kmem_cache_alloc(sigqueue_cachep, flags); |
327 | } else { | 327 | } else { |
328 | print_dropped_signal(sig); | 328 | print_dropped_signal(sig); |
329 | } | 329 | } |
330 | 330 | ||
331 | if (unlikely(q == NULL)) { | 331 | if (unlikely(q == NULL)) { |
332 | atomic_dec(&user->sigpending); | 332 | atomic_dec(&user->sigpending); |
333 | free_uid(user); | 333 | free_uid(user); |
334 | } else { | 334 | } else { |
335 | INIT_LIST_HEAD(&q->list); | 335 | INIT_LIST_HEAD(&q->list); |
336 | q->flags = 0; | 336 | q->flags = 0; |
337 | q->user = user; | 337 | q->user = user; |
338 | } | 338 | } |
339 | 339 | ||
340 | return q; | 340 | return q; |
341 | } | 341 | } |
342 | 342 | ||
343 | static void __sigqueue_free(struct sigqueue *q) | 343 | static void __sigqueue_free(struct sigqueue *q) |
344 | { | 344 | { |
345 | if (q->flags & SIGQUEUE_PREALLOC) | 345 | if (q->flags & SIGQUEUE_PREALLOC) |
346 | return; | 346 | return; |
347 | atomic_dec(&q->user->sigpending); | 347 | atomic_dec(&q->user->sigpending); |
348 | free_uid(q->user); | 348 | free_uid(q->user); |
349 | kmem_cache_free(sigqueue_cachep, q); | 349 | kmem_cache_free(sigqueue_cachep, q); |
350 | } | 350 | } |
351 | 351 | ||
352 | void flush_sigqueue(struct sigpending *queue) | 352 | void flush_sigqueue(struct sigpending *queue) |
353 | { | 353 | { |
354 | struct sigqueue *q; | 354 | struct sigqueue *q; |
355 | 355 | ||
356 | sigemptyset(&queue->signal); | 356 | sigemptyset(&queue->signal); |
357 | while (!list_empty(&queue->list)) { | 357 | while (!list_empty(&queue->list)) { |
358 | q = list_entry(queue->list.next, struct sigqueue , list); | 358 | q = list_entry(queue->list.next, struct sigqueue , list); |
359 | list_del_init(&q->list); | 359 | list_del_init(&q->list); |
360 | __sigqueue_free(q); | 360 | __sigqueue_free(q); |
361 | } | 361 | } |
362 | } | 362 | } |
363 | 363 | ||
364 | /* | 364 | /* |
365 | * Flush all pending signals for a task. | 365 | * Flush all pending signals for a task. |
366 | */ | 366 | */ |
367 | void __flush_signals(struct task_struct *t) | 367 | void __flush_signals(struct task_struct *t) |
368 | { | 368 | { |
369 | clear_tsk_thread_flag(t, TIF_SIGPENDING); | 369 | clear_tsk_thread_flag(t, TIF_SIGPENDING); |
370 | flush_sigqueue(&t->pending); | 370 | flush_sigqueue(&t->pending); |
371 | flush_sigqueue(&t->signal->shared_pending); | 371 | flush_sigqueue(&t->signal->shared_pending); |
372 | } | 372 | } |
373 | 373 | ||
374 | void flush_signals(struct task_struct *t) | 374 | void flush_signals(struct task_struct *t) |
375 | { | 375 | { |
376 | unsigned long flags; | 376 | unsigned long flags; |
377 | 377 | ||
378 | spin_lock_irqsave(&t->sighand->siglock, flags); | 378 | spin_lock_irqsave(&t->sighand->siglock, flags); |
379 | __flush_signals(t); | 379 | __flush_signals(t); |
380 | spin_unlock_irqrestore(&t->sighand->siglock, flags); | 380 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
381 | } | 381 | } |
382 | 382 | ||
383 | static void __flush_itimer_signals(struct sigpending *pending) | 383 | static void __flush_itimer_signals(struct sigpending *pending) |
384 | { | 384 | { |
385 | sigset_t signal, retain; | 385 | sigset_t signal, retain; |
386 | struct sigqueue *q, *n; | 386 | struct sigqueue *q, *n; |
387 | 387 | ||
388 | signal = pending->signal; | 388 | signal = pending->signal; |
389 | sigemptyset(&retain); | 389 | sigemptyset(&retain); |
390 | 390 | ||
391 | list_for_each_entry_safe(q, n, &pending->list, list) { | 391 | list_for_each_entry_safe(q, n, &pending->list, list) { |
392 | int sig = q->info.si_signo; | 392 | int sig = q->info.si_signo; |
393 | 393 | ||
394 | if (likely(q->info.si_code != SI_TIMER)) { | 394 | if (likely(q->info.si_code != SI_TIMER)) { |
395 | sigaddset(&retain, sig); | 395 | sigaddset(&retain, sig); |
396 | } else { | 396 | } else { |
397 | sigdelset(&signal, sig); | 397 | sigdelset(&signal, sig); |
398 | list_del_init(&q->list); | 398 | list_del_init(&q->list); |
399 | __sigqueue_free(q); | 399 | __sigqueue_free(q); |
400 | } | 400 | } |
401 | } | 401 | } |
402 | 402 | ||
403 | sigorsets(&pending->signal, &signal, &retain); | 403 | sigorsets(&pending->signal, &signal, &retain); |
404 | } | 404 | } |
405 | 405 | ||
406 | void flush_itimer_signals(void) | 406 | void flush_itimer_signals(void) |
407 | { | 407 | { |
408 | struct task_struct *tsk = current; | 408 | struct task_struct *tsk = current; |
409 | unsigned long flags; | 409 | unsigned long flags; |
410 | 410 | ||
411 | spin_lock_irqsave(&tsk->sighand->siglock, flags); | 411 | spin_lock_irqsave(&tsk->sighand->siglock, flags); |
412 | __flush_itimer_signals(&tsk->pending); | 412 | __flush_itimer_signals(&tsk->pending); |
413 | __flush_itimer_signals(&tsk->signal->shared_pending); | 413 | __flush_itimer_signals(&tsk->signal->shared_pending); |
414 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); | 414 | spin_unlock_irqrestore(&tsk->sighand->siglock, flags); |
415 | } | 415 | } |
416 | 416 | ||
417 | void ignore_signals(struct task_struct *t) | 417 | void ignore_signals(struct task_struct *t) |
418 | { | 418 | { |
419 | int i; | 419 | int i; |
420 | 420 | ||
421 | for (i = 0; i < _NSIG; ++i) | 421 | for (i = 0; i < _NSIG; ++i) |
422 | t->sighand->action[i].sa.sa_handler = SIG_IGN; | 422 | t->sighand->action[i].sa.sa_handler = SIG_IGN; |
423 | 423 | ||
424 | flush_signals(t); | 424 | flush_signals(t); |
425 | } | 425 | } |
426 | 426 | ||
427 | /* | 427 | /* |
428 | * Flush all handlers for a task. | 428 | * Flush all handlers for a task. |
429 | */ | 429 | */ |
430 | 430 | ||
431 | void | 431 | void |
432 | flush_signal_handlers(struct task_struct *t, int force_default) | 432 | flush_signal_handlers(struct task_struct *t, int force_default) |
433 | { | 433 | { |
434 | int i; | 434 | int i; |
435 | struct k_sigaction *ka = &t->sighand->action[0]; | 435 | struct k_sigaction *ka = &t->sighand->action[0]; |
436 | for (i = _NSIG ; i != 0 ; i--) { | 436 | for (i = _NSIG ; i != 0 ; i--) { |
437 | if (force_default || ka->sa.sa_handler != SIG_IGN) | 437 | if (force_default || ka->sa.sa_handler != SIG_IGN) |
438 | ka->sa.sa_handler = SIG_DFL; | 438 | ka->sa.sa_handler = SIG_DFL; |
439 | ka->sa.sa_flags = 0; | 439 | ka->sa.sa_flags = 0; |
440 | sigemptyset(&ka->sa.sa_mask); | 440 | sigemptyset(&ka->sa.sa_mask); |
441 | ka++; | 441 | ka++; |
442 | } | 442 | } |
443 | } | 443 | } |
444 | 444 | ||
445 | int unhandled_signal(struct task_struct *tsk, int sig) | 445 | int unhandled_signal(struct task_struct *tsk, int sig) |
446 | { | 446 | { |
447 | void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler; | 447 | void __user *handler = tsk->sighand->action[sig-1].sa.sa_handler; |
448 | if (is_global_init(tsk)) | 448 | if (is_global_init(tsk)) |
449 | return 1; | 449 | return 1; |
450 | if (handler != SIG_IGN && handler != SIG_DFL) | 450 | if (handler != SIG_IGN && handler != SIG_DFL) |
451 | return 0; | 451 | return 0; |
452 | return !tracehook_consider_fatal_signal(tsk, sig); | 452 | return !tracehook_consider_fatal_signal(tsk, sig); |
453 | } | 453 | } |
454 | 454 | ||
455 | /* | 455 | /* |
456 | * Notify the system that a driver wants to block all signals for this | 456 | * Notify the system that a driver wants to block all signals for this |
457 | * process, and wants to be notified if any signals at all were to be | 457 | * process, and wants to be notified if any signals at all were to be |
458 | * sent/acted upon. If the notifier routine returns non-zero, then the | 458 | * sent/acted upon. If the notifier routine returns non-zero, then the |
459 | * signal will be acted upon after all. If the notifier routine returns 0, | 459 | * signal will be acted upon after all. If the notifier routine returns 0, |
460 | * then then signal will be blocked. Only one block per process is | 460 | * then then signal will be blocked. Only one block per process is |
461 | * allowed. priv is a pointer to private data that the notifier routine | 461 | * allowed. priv is a pointer to private data that the notifier routine |
462 | * can use to determine if the signal should be blocked or not. | 462 | * can use to determine if the signal should be blocked or not. |
463 | */ | 463 | */ |
464 | void | 464 | void |
465 | block_all_signals(int (*notifier)(void *priv), void *priv, sigset_t *mask) | 465 | block_all_signals(int (*notifier)(void *priv), void *priv, sigset_t *mask) |
466 | { | 466 | { |
467 | unsigned long flags; | 467 | unsigned long flags; |
468 | 468 | ||
469 | spin_lock_irqsave(¤t->sighand->siglock, flags); | 469 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
470 | current->notifier_mask = mask; | 470 | current->notifier_mask = mask; |
471 | current->notifier_data = priv; | 471 | current->notifier_data = priv; |
472 | current->notifier = notifier; | 472 | current->notifier = notifier; |
473 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | 473 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
474 | } | 474 | } |
475 | 475 | ||
476 | /* Notify the system that blocking has ended. */ | 476 | /* Notify the system that blocking has ended. */ |
477 | 477 | ||
478 | void | 478 | void |
479 | unblock_all_signals(void) | 479 | unblock_all_signals(void) |
480 | { | 480 | { |
481 | unsigned long flags; | 481 | unsigned long flags; |
482 | 482 | ||
483 | spin_lock_irqsave(¤t->sighand->siglock, flags); | 483 | spin_lock_irqsave(¤t->sighand->siglock, flags); |
484 | current->notifier = NULL; | 484 | current->notifier = NULL; |
485 | current->notifier_data = NULL; | 485 | current->notifier_data = NULL; |
486 | recalc_sigpending(); | 486 | recalc_sigpending(); |
487 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); | 487 | spin_unlock_irqrestore(¤t->sighand->siglock, flags); |
488 | } | 488 | } |
489 | 489 | ||
490 | static void collect_signal(int sig, struct sigpending *list, siginfo_t *info) | 490 | static void collect_signal(int sig, struct sigpending *list, siginfo_t *info) |
491 | { | 491 | { |
492 | struct sigqueue *q, *first = NULL; | 492 | struct sigqueue *q, *first = NULL; |
493 | 493 | ||
494 | /* | 494 | /* |
495 | * Collect the siginfo appropriate to this signal. Check if | 495 | * Collect the siginfo appropriate to this signal. Check if |
496 | * there is another siginfo for the same signal. | 496 | * there is another siginfo for the same signal. |
497 | */ | 497 | */ |
498 | list_for_each_entry(q, &list->list, list) { | 498 | list_for_each_entry(q, &list->list, list) { |
499 | if (q->info.si_signo == sig) { | 499 | if (q->info.si_signo == sig) { |
500 | if (first) | 500 | if (first) |
501 | goto still_pending; | 501 | goto still_pending; |
502 | first = q; | 502 | first = q; |
503 | } | 503 | } |
504 | } | 504 | } |
505 | 505 | ||
506 | sigdelset(&list->signal, sig); | 506 | sigdelset(&list->signal, sig); |
507 | 507 | ||
508 | if (first) { | 508 | if (first) { |
509 | still_pending: | 509 | still_pending: |
510 | list_del_init(&first->list); | 510 | list_del_init(&first->list); |
511 | copy_siginfo(info, &first->info); | 511 | copy_siginfo(info, &first->info); |
512 | __sigqueue_free(first); | 512 | __sigqueue_free(first); |
513 | } else { | 513 | } else { |
514 | /* | 514 | /* |
515 | * Ok, it wasn't in the queue. This must be | 515 | * Ok, it wasn't in the queue. This must be |
516 | * a fast-pathed signal or we must have been | 516 | * a fast-pathed signal or we must have been |
517 | * out of queue space. So zero out the info. | 517 | * out of queue space. So zero out the info. |
518 | */ | 518 | */ |
519 | info->si_signo = sig; | 519 | info->si_signo = sig; |
520 | info->si_errno = 0; | 520 | info->si_errno = 0; |
521 | info->si_code = SI_USER; | 521 | info->si_code = SI_USER; |
522 | info->si_pid = 0; | 522 | info->si_pid = 0; |
523 | info->si_uid = 0; | 523 | info->si_uid = 0; |
524 | } | 524 | } |
525 | } | 525 | } |
526 | 526 | ||
527 | static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, | 527 | static int __dequeue_signal(struct sigpending *pending, sigset_t *mask, |
528 | siginfo_t *info) | 528 | siginfo_t *info) |
529 | { | 529 | { |
530 | int sig = next_signal(pending, mask); | 530 | int sig = next_signal(pending, mask); |
531 | 531 | ||
532 | if (sig) { | 532 | if (sig) { |
533 | if (current->notifier) { | 533 | if (current->notifier) { |
534 | if (sigismember(current->notifier_mask, sig)) { | 534 | if (sigismember(current->notifier_mask, sig)) { |
535 | if (!(current->notifier)(current->notifier_data)) { | 535 | if (!(current->notifier)(current->notifier_data)) { |
536 | clear_thread_flag(TIF_SIGPENDING); | 536 | clear_thread_flag(TIF_SIGPENDING); |
537 | return 0; | 537 | return 0; |
538 | } | 538 | } |
539 | } | 539 | } |
540 | } | 540 | } |
541 | 541 | ||
542 | collect_signal(sig, pending, info); | 542 | collect_signal(sig, pending, info); |
543 | } | 543 | } |
544 | 544 | ||
545 | return sig; | 545 | return sig; |
546 | } | 546 | } |
547 | 547 | ||
548 | /* | 548 | /* |
549 | * Dequeue a signal and return the element to the caller, which is | 549 | * Dequeue a signal and return the element to the caller, which is |
550 | * expected to free it. | 550 | * expected to free it. |
551 | * | 551 | * |
552 | * All callers have to hold the siglock. | 552 | * All callers have to hold the siglock. |
553 | */ | 553 | */ |
554 | int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) | 554 | int dequeue_signal(struct task_struct *tsk, sigset_t *mask, siginfo_t *info) |
555 | { | 555 | { |
556 | int signr; | 556 | int signr; |
557 | 557 | ||
558 | /* We only dequeue private signals from ourselves, we don't let | 558 | /* We only dequeue private signals from ourselves, we don't let |
559 | * signalfd steal them | 559 | * signalfd steal them |
560 | */ | 560 | */ |
561 | signr = __dequeue_signal(&tsk->pending, mask, info); | 561 | signr = __dequeue_signal(&tsk->pending, mask, info); |
562 | if (!signr) { | 562 | if (!signr) { |
563 | signr = __dequeue_signal(&tsk->signal->shared_pending, | 563 | signr = __dequeue_signal(&tsk->signal->shared_pending, |
564 | mask, info); | 564 | mask, info); |
565 | /* | 565 | /* |
566 | * itimer signal ? | 566 | * itimer signal ? |
567 | * | 567 | * |
568 | * itimers are process shared and we restart periodic | 568 | * itimers are process shared and we restart periodic |
569 | * itimers in the signal delivery path to prevent DoS | 569 | * itimers in the signal delivery path to prevent DoS |
570 | * attacks in the high resolution timer case. This is | 570 | * attacks in the high resolution timer case. This is |
571 | * compliant with the old way of self-restarting | 571 | * compliant with the old way of self-restarting |
572 | * itimers, as the SIGALRM is a legacy signal and only | 572 | * itimers, as the SIGALRM is a legacy signal and only |
573 | * queued once. Changing the restart behaviour to | 573 | * queued once. Changing the restart behaviour to |
574 | * restart the timer in the signal dequeue path is | 574 | * restart the timer in the signal dequeue path is |
575 | * reducing the timer noise on heavy loaded !highres | 575 | * reducing the timer noise on heavy loaded !highres |
576 | * systems too. | 576 | * systems too. |
577 | */ | 577 | */ |
578 | if (unlikely(signr == SIGALRM)) { | 578 | if (unlikely(signr == SIGALRM)) { |
579 | struct hrtimer *tmr = &tsk->signal->real_timer; | 579 | struct hrtimer *tmr = &tsk->signal->real_timer; |
580 | 580 | ||
581 | if (!hrtimer_is_queued(tmr) && | 581 | if (!hrtimer_is_queued(tmr) && |
582 | tsk->signal->it_real_incr.tv64 != 0) { | 582 | tsk->signal->it_real_incr.tv64 != 0) { |
583 | hrtimer_forward(tmr, tmr->base->get_time(), | 583 | hrtimer_forward(tmr, tmr->base->get_time(), |
584 | tsk->signal->it_real_incr); | 584 | tsk->signal->it_real_incr); |
585 | hrtimer_restart(tmr); | 585 | hrtimer_restart(tmr); |
586 | } | 586 | } |
587 | } | 587 | } |
588 | } | 588 | } |
589 | 589 | ||
590 | recalc_sigpending(); | 590 | recalc_sigpending(); |
591 | if (!signr) | 591 | if (!signr) |
592 | return 0; | 592 | return 0; |
593 | 593 | ||
594 | if (unlikely(sig_kernel_stop(signr))) { | 594 | if (unlikely(sig_kernel_stop(signr))) { |
595 | /* | 595 | /* |
596 | * Set a marker that we have dequeued a stop signal. Our | 596 | * Set a marker that we have dequeued a stop signal. Our |
597 | * caller might release the siglock and then the pending | 597 | * caller might release the siglock and then the pending |
598 | * stop signal it is about to process is no longer in the | 598 | * stop signal it is about to process is no longer in the |
599 | * pending bitmasks, but must still be cleared by a SIGCONT | 599 | * pending bitmasks, but must still be cleared by a SIGCONT |
600 | * (and overruled by a SIGKILL). So those cases clear this | 600 | * (and overruled by a SIGKILL). So those cases clear this |
601 | * shared flag after we've set it. Note that this flag may | 601 | * shared flag after we've set it. Note that this flag may |
602 | * remain set after the signal we return is ignored or | 602 | * remain set after the signal we return is ignored or |
603 | * handled. That doesn't matter because its only purpose | 603 | * handled. That doesn't matter because its only purpose |
604 | * is to alert stop-signal processing code when another | 604 | * is to alert stop-signal processing code when another |
605 | * processor has come along and cleared the flag. | 605 | * processor has come along and cleared the flag. |
606 | */ | 606 | */ |
607 | current->group_stop |= GROUP_STOP_DEQUEUED; | 607 | current->group_stop |= GROUP_STOP_DEQUEUED; |
608 | } | 608 | } |
609 | if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) { | 609 | if ((info->si_code & __SI_MASK) == __SI_TIMER && info->si_sys_private) { |
610 | /* | 610 | /* |
611 | * Release the siglock to ensure proper locking order | 611 | * Release the siglock to ensure proper locking order |
612 | * of timer locks outside of siglocks. Note, we leave | 612 | * of timer locks outside of siglocks. Note, we leave |
613 | * irqs disabled here, since the posix-timers code is | 613 | * irqs disabled here, since the posix-timers code is |
614 | * about to disable them again anyway. | 614 | * about to disable them again anyway. |
615 | */ | 615 | */ |
616 | spin_unlock(&tsk->sighand->siglock); | 616 | spin_unlock(&tsk->sighand->siglock); |
617 | do_schedule_next_timer(info); | 617 | do_schedule_next_timer(info); |
618 | spin_lock(&tsk->sighand->siglock); | 618 | spin_lock(&tsk->sighand->siglock); |
619 | } | 619 | } |
620 | return signr; | 620 | return signr; |
621 | } | 621 | } |
622 | 622 | ||
623 | /* | 623 | /* |
624 | * Tell a process that it has a new active signal.. | 624 | * Tell a process that it has a new active signal.. |
625 | * | 625 | * |
626 | * NOTE! we rely on the previous spin_lock to | 626 | * NOTE! we rely on the previous spin_lock to |
627 | * lock interrupts for us! We can only be called with | 627 | * lock interrupts for us! We can only be called with |
628 | * "siglock" held, and the local interrupt must | 628 | * "siglock" held, and the local interrupt must |
629 | * have been disabled when that got acquired! | 629 | * have been disabled when that got acquired! |
630 | * | 630 | * |
631 | * No need to set need_resched since signal event passing | 631 | * No need to set need_resched since signal event passing |
632 | * goes through ->blocked | 632 | * goes through ->blocked |
633 | */ | 633 | */ |
634 | void signal_wake_up(struct task_struct *t, int resume) | 634 | void signal_wake_up(struct task_struct *t, int resume) |
635 | { | 635 | { |
636 | unsigned int mask; | 636 | unsigned int mask; |
637 | 637 | ||
638 | set_tsk_thread_flag(t, TIF_SIGPENDING); | 638 | set_tsk_thread_flag(t, TIF_SIGPENDING); |
639 | 639 | ||
640 | /* | 640 | /* |
641 | * For SIGKILL, we want to wake it up in the stopped/traced/killable | 641 | * For SIGKILL, we want to wake it up in the stopped/traced/killable |
642 | * case. We don't check t->state here because there is a race with it | 642 | * case. We don't check t->state here because there is a race with it |
643 | * executing another processor and just now entering stopped state. | 643 | * executing another processor and just now entering stopped state. |
644 | * By using wake_up_state, we ensure the process will wake up and | 644 | * By using wake_up_state, we ensure the process will wake up and |
645 | * handle its death signal. | 645 | * handle its death signal. |
646 | */ | 646 | */ |
647 | mask = TASK_INTERRUPTIBLE; | 647 | mask = TASK_INTERRUPTIBLE; |
648 | if (resume) | 648 | if (resume) |
649 | mask |= TASK_WAKEKILL; | 649 | mask |= TASK_WAKEKILL; |
650 | if (!wake_up_state(t, mask)) | 650 | if (!wake_up_state(t, mask)) |
651 | kick_process(t); | 651 | kick_process(t); |
652 | } | 652 | } |
653 | 653 | ||
654 | /* | 654 | /* |
655 | * Remove signals in mask from the pending set and queue. | 655 | * Remove signals in mask from the pending set and queue. |
656 | * Returns 1 if any signals were found. | 656 | * Returns 1 if any signals were found. |
657 | * | 657 | * |
658 | * All callers must be holding the siglock. | 658 | * All callers must be holding the siglock. |
659 | * | 659 | * |
660 | * This version takes a sigset mask and looks at all signals, | 660 | * This version takes a sigset mask and looks at all signals, |
661 | * not just those in the first mask word. | 661 | * not just those in the first mask word. |
662 | */ | 662 | */ |
663 | static int rm_from_queue_full(sigset_t *mask, struct sigpending *s) | 663 | static int rm_from_queue_full(sigset_t *mask, struct sigpending *s) |
664 | { | 664 | { |
665 | struct sigqueue *q, *n; | 665 | struct sigqueue *q, *n; |
666 | sigset_t m; | 666 | sigset_t m; |
667 | 667 | ||
668 | sigandsets(&m, mask, &s->signal); | 668 | sigandsets(&m, mask, &s->signal); |
669 | if (sigisemptyset(&m)) | 669 | if (sigisemptyset(&m)) |
670 | return 0; | 670 | return 0; |
671 | 671 | ||
672 | sigandnsets(&s->signal, &s->signal, mask); | 672 | sigandnsets(&s->signal, &s->signal, mask); |
673 | list_for_each_entry_safe(q, n, &s->list, list) { | 673 | list_for_each_entry_safe(q, n, &s->list, list) { |
674 | if (sigismember(mask, q->info.si_signo)) { | 674 | if (sigismember(mask, q->info.si_signo)) { |
675 | list_del_init(&q->list); | 675 | list_del_init(&q->list); |
676 | __sigqueue_free(q); | 676 | __sigqueue_free(q); |
677 | } | 677 | } |
678 | } | 678 | } |
679 | return 1; | 679 | return 1; |
680 | } | 680 | } |
681 | /* | 681 | /* |
682 | * Remove signals in mask from the pending set and queue. | 682 | * Remove signals in mask from the pending set and queue. |
683 | * Returns 1 if any signals were found. | 683 | * Returns 1 if any signals were found. |
684 | * | 684 | * |
685 | * All callers must be holding the siglock. | 685 | * All callers must be holding the siglock. |
686 | */ | 686 | */ |
687 | static int rm_from_queue(unsigned long mask, struct sigpending *s) | 687 | static int rm_from_queue(unsigned long mask, struct sigpending *s) |
688 | { | 688 | { |
689 | struct sigqueue *q, *n; | 689 | struct sigqueue *q, *n; |
690 | 690 | ||
691 | if (!sigtestsetmask(&s->signal, mask)) | 691 | if (!sigtestsetmask(&s->signal, mask)) |
692 | return 0; | 692 | return 0; |
693 | 693 | ||
694 | sigdelsetmask(&s->signal, mask); | 694 | sigdelsetmask(&s->signal, mask); |
695 | list_for_each_entry_safe(q, n, &s->list, list) { | 695 | list_for_each_entry_safe(q, n, &s->list, list) { |
696 | if (q->info.si_signo < SIGRTMIN && | 696 | if (q->info.si_signo < SIGRTMIN && |
697 | (mask & sigmask(q->info.si_signo))) { | 697 | (mask & sigmask(q->info.si_signo))) { |
698 | list_del_init(&q->list); | 698 | list_del_init(&q->list); |
699 | __sigqueue_free(q); | 699 | __sigqueue_free(q); |
700 | } | 700 | } |
701 | } | 701 | } |
702 | return 1; | 702 | return 1; |
703 | } | 703 | } |
704 | 704 | ||
705 | static inline int is_si_special(const struct siginfo *info) | 705 | static inline int is_si_special(const struct siginfo *info) |
706 | { | 706 | { |
707 | return info <= SEND_SIG_FORCED; | 707 | return info <= SEND_SIG_FORCED; |
708 | } | 708 | } |
709 | 709 | ||
710 | static inline bool si_fromuser(const struct siginfo *info) | 710 | static inline bool si_fromuser(const struct siginfo *info) |
711 | { | 711 | { |
712 | return info == SEND_SIG_NOINFO || | 712 | return info == SEND_SIG_NOINFO || |
713 | (!is_si_special(info) && SI_FROMUSER(info)); | 713 | (!is_si_special(info) && SI_FROMUSER(info)); |
714 | } | 714 | } |
715 | 715 | ||
716 | /* | 716 | /* |
717 | * called with RCU read lock from check_kill_permission() | 717 | * called with RCU read lock from check_kill_permission() |
718 | */ | 718 | */ |
719 | static int kill_ok_by_cred(struct task_struct *t) | 719 | static int kill_ok_by_cred(struct task_struct *t) |
720 | { | 720 | { |
721 | const struct cred *cred = current_cred(); | 721 | const struct cred *cred = current_cred(); |
722 | const struct cred *tcred = __task_cred(t); | 722 | const struct cred *tcred = __task_cred(t); |
723 | 723 | ||
724 | if (cred->user->user_ns == tcred->user->user_ns && | 724 | if (cred->user->user_ns == tcred->user->user_ns && |
725 | (cred->euid == tcred->suid || | 725 | (cred->euid == tcred->suid || |
726 | cred->euid == tcred->uid || | 726 | cred->euid == tcred->uid || |
727 | cred->uid == tcred->suid || | 727 | cred->uid == tcred->suid || |
728 | cred->uid == tcred->uid)) | 728 | cred->uid == tcred->uid)) |
729 | return 1; | 729 | return 1; |
730 | 730 | ||
731 | if (ns_capable(tcred->user->user_ns, CAP_KILL)) | 731 | if (ns_capable(tcred->user->user_ns, CAP_KILL)) |
732 | return 1; | 732 | return 1; |
733 | 733 | ||
734 | return 0; | 734 | return 0; |
735 | } | 735 | } |
736 | 736 | ||
737 | /* | 737 | /* |
738 | * Bad permissions for sending the signal | 738 | * Bad permissions for sending the signal |
739 | * - the caller must hold the RCU read lock | 739 | * - the caller must hold the RCU read lock |
740 | */ | 740 | */ |
741 | static int check_kill_permission(int sig, struct siginfo *info, | 741 | static int check_kill_permission(int sig, struct siginfo *info, |
742 | struct task_struct *t) | 742 | struct task_struct *t) |
743 | { | 743 | { |
744 | struct pid *sid; | 744 | struct pid *sid; |
745 | int error; | 745 | int error; |
746 | 746 | ||
747 | if (!valid_signal(sig)) | 747 | if (!valid_signal(sig)) |
748 | return -EINVAL; | 748 | return -EINVAL; |
749 | 749 | ||
750 | if (!si_fromuser(info)) | 750 | if (!si_fromuser(info)) |
751 | return 0; | 751 | return 0; |
752 | 752 | ||
753 | error = audit_signal_info(sig, t); /* Let audit system see the signal */ | 753 | error = audit_signal_info(sig, t); /* Let audit system see the signal */ |
754 | if (error) | 754 | if (error) |
755 | return error; | 755 | return error; |
756 | 756 | ||
757 | if (!same_thread_group(current, t) && | 757 | if (!same_thread_group(current, t) && |
758 | !kill_ok_by_cred(t)) { | 758 | !kill_ok_by_cred(t)) { |
759 | switch (sig) { | 759 | switch (sig) { |
760 | case SIGCONT: | 760 | case SIGCONT: |
761 | sid = task_session(t); | 761 | sid = task_session(t); |
762 | /* | 762 | /* |
763 | * We don't return the error if sid == NULL. The | 763 | * We don't return the error if sid == NULL. The |
764 | * task was unhashed, the caller must notice this. | 764 | * task was unhashed, the caller must notice this. |
765 | */ | 765 | */ |
766 | if (!sid || sid == task_session(current)) | 766 | if (!sid || sid == task_session(current)) |
767 | break; | 767 | break; |
768 | default: | 768 | default: |
769 | return -EPERM; | 769 | return -EPERM; |
770 | } | 770 | } |
771 | } | 771 | } |
772 | 772 | ||
773 | return security_task_kill(t, info, sig, 0); | 773 | return security_task_kill(t, info, sig, 0); |
774 | } | 774 | } |
775 | 775 | ||
776 | /* | 776 | /* |
777 | * Handle magic process-wide effects of stop/continue signals. Unlike | 777 | * Handle magic process-wide effects of stop/continue signals. Unlike |
778 | * the signal actions, these happen immediately at signal-generation | 778 | * the signal actions, these happen immediately at signal-generation |
779 | * time regardless of blocking, ignoring, or handling. This does the | 779 | * time regardless of blocking, ignoring, or handling. This does the |
780 | * actual continuing for SIGCONT, but not the actual stopping for stop | 780 | * actual continuing for SIGCONT, but not the actual stopping for stop |
781 | * signals. The process stop is done as a signal action for SIG_DFL. | 781 | * signals. The process stop is done as a signal action for SIG_DFL. |
782 | * | 782 | * |
783 | * Returns true if the signal should be actually delivered, otherwise | 783 | * Returns true if the signal should be actually delivered, otherwise |
784 | * it should be dropped. | 784 | * it should be dropped. |
785 | */ | 785 | */ |
786 | static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns) | 786 | static int prepare_signal(int sig, struct task_struct *p, int from_ancestor_ns) |
787 | { | 787 | { |
788 | struct signal_struct *signal = p->signal; | 788 | struct signal_struct *signal = p->signal; |
789 | struct task_struct *t; | 789 | struct task_struct *t; |
790 | 790 | ||
791 | if (unlikely(signal->flags & SIGNAL_GROUP_EXIT)) { | 791 | if (unlikely(signal->flags & SIGNAL_GROUP_EXIT)) { |
792 | /* | 792 | /* |
793 | * The process is in the middle of dying, nothing to do. | 793 | * The process is in the middle of dying, nothing to do. |
794 | */ | 794 | */ |
795 | } else if (sig_kernel_stop(sig)) { | 795 | } else if (sig_kernel_stop(sig)) { |
796 | /* | 796 | /* |
797 | * This is a stop signal. Remove SIGCONT from all queues. | 797 | * This is a stop signal. Remove SIGCONT from all queues. |
798 | */ | 798 | */ |
799 | rm_from_queue(sigmask(SIGCONT), &signal->shared_pending); | 799 | rm_from_queue(sigmask(SIGCONT), &signal->shared_pending); |
800 | t = p; | 800 | t = p; |
801 | do { | 801 | do { |
802 | rm_from_queue(sigmask(SIGCONT), &t->pending); | 802 | rm_from_queue(sigmask(SIGCONT), &t->pending); |
803 | } while_each_thread(p, t); | 803 | } while_each_thread(p, t); |
804 | } else if (sig == SIGCONT) { | 804 | } else if (sig == SIGCONT) { |
805 | unsigned int why; | 805 | unsigned int why; |
806 | /* | 806 | /* |
807 | * Remove all stop signals from all queues, wake all threads. | 807 | * Remove all stop signals from all queues, wake all threads. |
808 | */ | 808 | */ |
809 | rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending); | 809 | rm_from_queue(SIG_KERNEL_STOP_MASK, &signal->shared_pending); |
810 | t = p; | 810 | t = p; |
811 | do { | 811 | do { |
812 | task_clear_group_stop_pending(t); | 812 | task_clear_group_stop_pending(t); |
813 | rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); | 813 | rm_from_queue(SIG_KERNEL_STOP_MASK, &t->pending); |
814 | wake_up_state(t, __TASK_STOPPED); | 814 | wake_up_state(t, __TASK_STOPPED); |
815 | } while_each_thread(p, t); | 815 | } while_each_thread(p, t); |
816 | 816 | ||
817 | /* | 817 | /* |
818 | * Notify the parent with CLD_CONTINUED if we were stopped. | 818 | * Notify the parent with CLD_CONTINUED if we were stopped. |
819 | * | 819 | * |
820 | * If we were in the middle of a group stop, we pretend it | 820 | * If we were in the middle of a group stop, we pretend it |
821 | * was already finished, and then continued. Since SIGCHLD | 821 | * was already finished, and then continued. Since SIGCHLD |
822 | * doesn't queue we report only CLD_STOPPED, as if the next | 822 | * doesn't queue we report only CLD_STOPPED, as if the next |
823 | * CLD_CONTINUED was dropped. | 823 | * CLD_CONTINUED was dropped. |
824 | */ | 824 | */ |
825 | why = 0; | 825 | why = 0; |
826 | if (signal->flags & SIGNAL_STOP_STOPPED) | 826 | if (signal->flags & SIGNAL_STOP_STOPPED) |
827 | why |= SIGNAL_CLD_CONTINUED; | 827 | why |= SIGNAL_CLD_CONTINUED; |
828 | else if (signal->group_stop_count) | 828 | else if (signal->group_stop_count) |
829 | why |= SIGNAL_CLD_STOPPED; | 829 | why |= SIGNAL_CLD_STOPPED; |
830 | 830 | ||
831 | if (why) { | 831 | if (why) { |
832 | /* | 832 | /* |
833 | * The first thread which returns from do_signal_stop() | 833 | * The first thread which returns from do_signal_stop() |
834 | * will take ->siglock, notice SIGNAL_CLD_MASK, and | 834 | * will take ->siglock, notice SIGNAL_CLD_MASK, and |
835 | * notify its parent. See get_signal_to_deliver(). | 835 | * notify its parent. See get_signal_to_deliver(). |
836 | */ | 836 | */ |
837 | signal->flags = why | SIGNAL_STOP_CONTINUED; | 837 | signal->flags = why | SIGNAL_STOP_CONTINUED; |
838 | signal->group_stop_count = 0; | 838 | signal->group_stop_count = 0; |
839 | signal->group_exit_code = 0; | 839 | signal->group_exit_code = 0; |
840 | } | 840 | } |
841 | } | 841 | } |
842 | 842 | ||
843 | return !sig_ignored(p, sig, from_ancestor_ns); | 843 | return !sig_ignored(p, sig, from_ancestor_ns); |
844 | } | 844 | } |
845 | 845 | ||
846 | /* | 846 | /* |
847 | * Test if P wants to take SIG. After we've checked all threads with this, | 847 | * Test if P wants to take SIG. After we've checked all threads with this, |
848 | * it's equivalent to finding no threads not blocking SIG. Any threads not | 848 | * it's equivalent to finding no threads not blocking SIG. Any threads not |
849 | * blocking SIG were ruled out because they are not running and already | 849 | * blocking SIG were ruled out because they are not running and already |
850 | * have pending signals. Such threads will dequeue from the shared queue | 850 | * have pending signals. Such threads will dequeue from the shared queue |
851 | * as soon as they're available, so putting the signal on the shared queue | 851 | * as soon as they're available, so putting the signal on the shared queue |
852 | * will be equivalent to sending it to one such thread. | 852 | * will be equivalent to sending it to one such thread. |
853 | */ | 853 | */ |
854 | static inline int wants_signal(int sig, struct task_struct *p) | 854 | static inline int wants_signal(int sig, struct task_struct *p) |
855 | { | 855 | { |
856 | if (sigismember(&p->blocked, sig)) | 856 | if (sigismember(&p->blocked, sig)) |
857 | return 0; | 857 | return 0; |
858 | if (p->flags & PF_EXITING) | 858 | if (p->flags & PF_EXITING) |
859 | return 0; | 859 | return 0; |
860 | if (sig == SIGKILL) | 860 | if (sig == SIGKILL) |
861 | return 1; | 861 | return 1; |
862 | if (task_is_stopped_or_traced(p)) | 862 | if (task_is_stopped_or_traced(p)) |
863 | return 0; | 863 | return 0; |
864 | return task_curr(p) || !signal_pending(p); | 864 | return task_curr(p) || !signal_pending(p); |
865 | } | 865 | } |
866 | 866 | ||
867 | static void complete_signal(int sig, struct task_struct *p, int group) | 867 | static void complete_signal(int sig, struct task_struct *p, int group) |
868 | { | 868 | { |
869 | struct signal_struct *signal = p->signal; | 869 | struct signal_struct *signal = p->signal; |
870 | struct task_struct *t; | 870 | struct task_struct *t; |
871 | 871 | ||
872 | /* | 872 | /* |
873 | * Now find a thread we can wake up to take the signal off the queue. | 873 | * Now find a thread we can wake up to take the signal off the queue. |
874 | * | 874 | * |
875 | * If the main thread wants the signal, it gets first crack. | 875 | * If the main thread wants the signal, it gets first crack. |
876 | * Probably the least surprising to the average bear. | 876 | * Probably the least surprising to the average bear. |
877 | */ | 877 | */ |
878 | if (wants_signal(sig, p)) | 878 | if (wants_signal(sig, p)) |
879 | t = p; | 879 | t = p; |
880 | else if (!group || thread_group_empty(p)) | 880 | else if (!group || thread_group_empty(p)) |
881 | /* | 881 | /* |
882 | * There is just one thread and it does not need to be woken. | 882 | * There is just one thread and it does not need to be woken. |
883 | * It will dequeue unblocked signals before it runs again. | 883 | * It will dequeue unblocked signals before it runs again. |
884 | */ | 884 | */ |
885 | return; | 885 | return; |
886 | else { | 886 | else { |
887 | /* | 887 | /* |
888 | * Otherwise try to find a suitable thread. | 888 | * Otherwise try to find a suitable thread. |
889 | */ | 889 | */ |
890 | t = signal->curr_target; | 890 | t = signal->curr_target; |
891 | while (!wants_signal(sig, t)) { | 891 | while (!wants_signal(sig, t)) { |
892 | t = next_thread(t); | 892 | t = next_thread(t); |
893 | if (t == signal->curr_target) | 893 | if (t == signal->curr_target) |
894 | /* | 894 | /* |
895 | * No thread needs to be woken. | 895 | * No thread needs to be woken. |
896 | * Any eligible threads will see | 896 | * Any eligible threads will see |
897 | * the signal in the queue soon. | 897 | * the signal in the queue soon. |
898 | */ | 898 | */ |
899 | return; | 899 | return; |
900 | } | 900 | } |
901 | signal->curr_target = t; | 901 | signal->curr_target = t; |
902 | } | 902 | } |
903 | 903 | ||
904 | /* | 904 | /* |
905 | * Found a killable thread. If the signal will be fatal, | 905 | * Found a killable thread. If the signal will be fatal, |
906 | * then start taking the whole group down immediately. | 906 | * then start taking the whole group down immediately. |
907 | */ | 907 | */ |
908 | if (sig_fatal(p, sig) && | 908 | if (sig_fatal(p, sig) && |
909 | !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) && | 909 | !(signal->flags & (SIGNAL_UNKILLABLE | SIGNAL_GROUP_EXIT)) && |
910 | !sigismember(&t->real_blocked, sig) && | 910 | !sigismember(&t->real_blocked, sig) && |
911 | (sig == SIGKILL || | 911 | (sig == SIGKILL || |
912 | !tracehook_consider_fatal_signal(t, sig))) { | 912 | !tracehook_consider_fatal_signal(t, sig))) { |
913 | /* | 913 | /* |
914 | * This signal will be fatal to the whole group. | 914 | * This signal will be fatal to the whole group. |
915 | */ | 915 | */ |
916 | if (!sig_kernel_coredump(sig)) { | 916 | if (!sig_kernel_coredump(sig)) { |
917 | /* | 917 | /* |
918 | * Start a group exit and wake everybody up. | 918 | * Start a group exit and wake everybody up. |
919 | * This way we don't have other threads | 919 | * This way we don't have other threads |
920 | * running and doing things after a slower | 920 | * running and doing things after a slower |
921 | * thread has the fatal signal pending. | 921 | * thread has the fatal signal pending. |
922 | */ | 922 | */ |
923 | signal->flags = SIGNAL_GROUP_EXIT; | 923 | signal->flags = SIGNAL_GROUP_EXIT; |
924 | signal->group_exit_code = sig; | 924 | signal->group_exit_code = sig; |
925 | signal->group_stop_count = 0; | 925 | signal->group_stop_count = 0; |
926 | t = p; | 926 | t = p; |
927 | do { | 927 | do { |
928 | task_clear_group_stop_pending(t); | 928 | task_clear_group_stop_pending(t); |
929 | sigaddset(&t->pending.signal, SIGKILL); | 929 | sigaddset(&t->pending.signal, SIGKILL); |
930 | signal_wake_up(t, 1); | 930 | signal_wake_up(t, 1); |
931 | } while_each_thread(p, t); | 931 | } while_each_thread(p, t); |
932 | return; | 932 | return; |
933 | } | 933 | } |
934 | } | 934 | } |
935 | 935 | ||
936 | /* | 936 | /* |
937 | * The signal is already in the shared-pending queue. | 937 | * The signal is already in the shared-pending queue. |
938 | * Tell the chosen thread to wake up and dequeue it. | 938 | * Tell the chosen thread to wake up and dequeue it. |
939 | */ | 939 | */ |
940 | signal_wake_up(t, sig == SIGKILL); | 940 | signal_wake_up(t, sig == SIGKILL); |
941 | return; | 941 | return; |
942 | } | 942 | } |
943 | 943 | ||
944 | static inline int legacy_queue(struct sigpending *signals, int sig) | 944 | static inline int legacy_queue(struct sigpending *signals, int sig) |
945 | { | 945 | { |
946 | return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); | 946 | return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); |
947 | } | 947 | } |
948 | 948 | ||
949 | static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, | 949 | static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, |
950 | int group, int from_ancestor_ns) | 950 | int group, int from_ancestor_ns) |
951 | { | 951 | { |
952 | struct sigpending *pending; | 952 | struct sigpending *pending; |
953 | struct sigqueue *q; | 953 | struct sigqueue *q; |
954 | int override_rlimit; | 954 | int override_rlimit; |
955 | 955 | ||
956 | trace_signal_generate(sig, info, t); | 956 | trace_signal_generate(sig, info, t); |
957 | 957 | ||
958 | assert_spin_locked(&t->sighand->siglock); | 958 | assert_spin_locked(&t->sighand->siglock); |
959 | 959 | ||
960 | if (!prepare_signal(sig, t, from_ancestor_ns)) | 960 | if (!prepare_signal(sig, t, from_ancestor_ns)) |
961 | return 0; | 961 | return 0; |
962 | 962 | ||
963 | pending = group ? &t->signal->shared_pending : &t->pending; | 963 | pending = group ? &t->signal->shared_pending : &t->pending; |
964 | /* | 964 | /* |
965 | * Short-circuit ignored signals and support queuing | 965 | * Short-circuit ignored signals and support queuing |
966 | * exactly one non-rt signal, so that we can get more | 966 | * exactly one non-rt signal, so that we can get more |
967 | * detailed information about the cause of the signal. | 967 | * detailed information about the cause of the signal. |
968 | */ | 968 | */ |
969 | if (legacy_queue(pending, sig)) | 969 | if (legacy_queue(pending, sig)) |
970 | return 0; | 970 | return 0; |
971 | /* | 971 | /* |
972 | * fast-pathed signals for kernel-internal things like SIGSTOP | 972 | * fast-pathed signals for kernel-internal things like SIGSTOP |
973 | * or SIGKILL. | 973 | * or SIGKILL. |
974 | */ | 974 | */ |
975 | if (info == SEND_SIG_FORCED) | 975 | if (info == SEND_SIG_FORCED) |
976 | goto out_set; | 976 | goto out_set; |
977 | 977 | ||
978 | /* | 978 | /* |
979 | * Real-time signals must be queued if sent by sigqueue, or | 979 | * Real-time signals must be queued if sent by sigqueue, or |
980 | * some other real-time mechanism. It is implementation | 980 | * some other real-time mechanism. It is implementation |
981 | * defined whether kill() does so. We attempt to do so, on | 981 | * defined whether kill() does so. We attempt to do so, on |
982 | * the principle of least surprise, but since kill is not | 982 | * the principle of least surprise, but since kill is not |
983 | * allowed to fail with EAGAIN when low on memory we just | 983 | * allowed to fail with EAGAIN when low on memory we just |
984 | * make sure at least one signal gets delivered and don't | 984 | * make sure at least one signal gets delivered and don't |
985 | * pass on the info struct. | 985 | * pass on the info struct. |
986 | */ | 986 | */ |
987 | if (sig < SIGRTMIN) | 987 | if (sig < SIGRTMIN) |
988 | override_rlimit = (is_si_special(info) || info->si_code >= 0); | 988 | override_rlimit = (is_si_special(info) || info->si_code >= 0); |
989 | else | 989 | else |
990 | override_rlimit = 0; | 990 | override_rlimit = 0; |
991 | 991 | ||
992 | q = __sigqueue_alloc(sig, t, GFP_ATOMIC | __GFP_NOTRACK_FALSE_POSITIVE, | 992 | q = __sigqueue_alloc(sig, t, GFP_ATOMIC | __GFP_NOTRACK_FALSE_POSITIVE, |
993 | override_rlimit); | 993 | override_rlimit); |
994 | if (q) { | 994 | if (q) { |
995 | list_add_tail(&q->list, &pending->list); | 995 | list_add_tail(&q->list, &pending->list); |
996 | switch ((unsigned long) info) { | 996 | switch ((unsigned long) info) { |
997 | case (unsigned long) SEND_SIG_NOINFO: | 997 | case (unsigned long) SEND_SIG_NOINFO: |
998 | q->info.si_signo = sig; | 998 | q->info.si_signo = sig; |
999 | q->info.si_errno = 0; | 999 | q->info.si_errno = 0; |
1000 | q->info.si_code = SI_USER; | 1000 | q->info.si_code = SI_USER; |
1001 | q->info.si_pid = task_tgid_nr_ns(current, | 1001 | q->info.si_pid = task_tgid_nr_ns(current, |
1002 | task_active_pid_ns(t)); | 1002 | task_active_pid_ns(t)); |
1003 | q->info.si_uid = current_uid(); | 1003 | q->info.si_uid = current_uid(); |
1004 | break; | 1004 | break; |
1005 | case (unsigned long) SEND_SIG_PRIV: | 1005 | case (unsigned long) SEND_SIG_PRIV: |
1006 | q->info.si_signo = sig; | 1006 | q->info.si_signo = sig; |
1007 | q->info.si_errno = 0; | 1007 | q->info.si_errno = 0; |
1008 | q->info.si_code = SI_KERNEL; | 1008 | q->info.si_code = SI_KERNEL; |
1009 | q->info.si_pid = 0; | 1009 | q->info.si_pid = 0; |
1010 | q->info.si_uid = 0; | 1010 | q->info.si_uid = 0; |
1011 | break; | 1011 | break; |
1012 | default: | 1012 | default: |
1013 | copy_siginfo(&q->info, info); | 1013 | copy_siginfo(&q->info, info); |
1014 | if (from_ancestor_ns) | 1014 | if (from_ancestor_ns) |
1015 | q->info.si_pid = 0; | 1015 | q->info.si_pid = 0; |
1016 | break; | 1016 | break; |
1017 | } | 1017 | } |
1018 | } else if (!is_si_special(info)) { | 1018 | } else if (!is_si_special(info)) { |
1019 | if (sig >= SIGRTMIN && info->si_code != SI_USER) { | 1019 | if (sig >= SIGRTMIN && info->si_code != SI_USER) { |
1020 | /* | 1020 | /* |
1021 | * Queue overflow, abort. We may abort if the | 1021 | * Queue overflow, abort. We may abort if the |
1022 | * signal was rt and sent by user using something | 1022 | * signal was rt and sent by user using something |
1023 | * other than kill(). | 1023 | * other than kill(). |
1024 | */ | 1024 | */ |
1025 | trace_signal_overflow_fail(sig, group, info); | 1025 | trace_signal_overflow_fail(sig, group, info); |
1026 | return -EAGAIN; | 1026 | return -EAGAIN; |
1027 | } else { | 1027 | } else { |
1028 | /* | 1028 | /* |
1029 | * This is a silent loss of information. We still | 1029 | * This is a silent loss of information. We still |
1030 | * send the signal, but the *info bits are lost. | 1030 | * send the signal, but the *info bits are lost. |
1031 | */ | 1031 | */ |
1032 | trace_signal_lose_info(sig, group, info); | 1032 | trace_signal_lose_info(sig, group, info); |
1033 | } | 1033 | } |
1034 | } | 1034 | } |
1035 | 1035 | ||
1036 | out_set: | 1036 | out_set: |
1037 | signalfd_notify(t, sig); | 1037 | signalfd_notify(t, sig); |
1038 | sigaddset(&pending->signal, sig); | 1038 | sigaddset(&pending->signal, sig); |
1039 | complete_signal(sig, t, group); | 1039 | complete_signal(sig, t, group); |
1040 | return 0; | 1040 | return 0; |
1041 | } | 1041 | } |
1042 | 1042 | ||
1043 | static int send_signal(int sig, struct siginfo *info, struct task_struct *t, | 1043 | static int send_signal(int sig, struct siginfo *info, struct task_struct *t, |
1044 | int group) | 1044 | int group) |
1045 | { | 1045 | { |
1046 | int from_ancestor_ns = 0; | 1046 | int from_ancestor_ns = 0; |
1047 | 1047 | ||
1048 | #ifdef CONFIG_PID_NS | 1048 | #ifdef CONFIG_PID_NS |
1049 | from_ancestor_ns = si_fromuser(info) && | 1049 | from_ancestor_ns = si_fromuser(info) && |
1050 | !task_pid_nr_ns(current, task_active_pid_ns(t)); | 1050 | !task_pid_nr_ns(current, task_active_pid_ns(t)); |
1051 | #endif | 1051 | #endif |
1052 | 1052 | ||
1053 | return __send_signal(sig, info, t, group, from_ancestor_ns); | 1053 | return __send_signal(sig, info, t, group, from_ancestor_ns); |
1054 | } | 1054 | } |
1055 | 1055 | ||
1056 | static void print_fatal_signal(struct pt_regs *regs, int signr) | 1056 | static void print_fatal_signal(struct pt_regs *regs, int signr) |
1057 | { | 1057 | { |
1058 | printk("%s/%d: potentially unexpected fatal signal %d.\n", | 1058 | printk("%s/%d: potentially unexpected fatal signal %d.\n", |
1059 | current->comm, task_pid_nr(current), signr); | 1059 | current->comm, task_pid_nr(current), signr); |
1060 | 1060 | ||
1061 | #if defined(__i386__) && !defined(__arch_um__) | 1061 | #if defined(__i386__) && !defined(__arch_um__) |
1062 | printk("code at %08lx: ", regs->ip); | 1062 | printk("code at %08lx: ", regs->ip); |
1063 | { | 1063 | { |
1064 | int i; | 1064 | int i; |
1065 | for (i = 0; i < 16; i++) { | 1065 | for (i = 0; i < 16; i++) { |
1066 | unsigned char insn; | 1066 | unsigned char insn; |
1067 | 1067 | ||
1068 | if (get_user(insn, (unsigned char *)(regs->ip + i))) | 1068 | if (get_user(insn, (unsigned char *)(regs->ip + i))) |
1069 | break; | 1069 | break; |
1070 | printk("%02x ", insn); | 1070 | printk("%02x ", insn); |
1071 | } | 1071 | } |
1072 | } | 1072 | } |
1073 | #endif | 1073 | #endif |
1074 | printk("\n"); | 1074 | printk("\n"); |
1075 | preempt_disable(); | 1075 | preempt_disable(); |
1076 | show_regs(regs); | 1076 | show_regs(regs); |
1077 | preempt_enable(); | 1077 | preempt_enable(); |
1078 | } | 1078 | } |
1079 | 1079 | ||
1080 | static int __init setup_print_fatal_signals(char *str) | 1080 | static int __init setup_print_fatal_signals(char *str) |
1081 | { | 1081 | { |
1082 | get_option (&str, &print_fatal_signals); | 1082 | get_option (&str, &print_fatal_signals); |
1083 | 1083 | ||
1084 | return 1; | 1084 | return 1; |
1085 | } | 1085 | } |
1086 | 1086 | ||
1087 | __setup("print-fatal-signals=", setup_print_fatal_signals); | 1087 | __setup("print-fatal-signals=", setup_print_fatal_signals); |
1088 | 1088 | ||
1089 | int | 1089 | int |
1090 | __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) | 1090 | __group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
1091 | { | 1091 | { |
1092 | return send_signal(sig, info, p, 1); | 1092 | return send_signal(sig, info, p, 1); |
1093 | } | 1093 | } |
1094 | 1094 | ||
1095 | static int | 1095 | static int |
1096 | specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) | 1096 | specific_send_sig_info(int sig, struct siginfo *info, struct task_struct *t) |
1097 | { | 1097 | { |
1098 | return send_signal(sig, info, t, 0); | 1098 | return send_signal(sig, info, t, 0); |
1099 | } | 1099 | } |
1100 | 1100 | ||
1101 | int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, | 1101 | int do_send_sig_info(int sig, struct siginfo *info, struct task_struct *p, |
1102 | bool group) | 1102 | bool group) |
1103 | { | 1103 | { |
1104 | unsigned long flags; | 1104 | unsigned long flags; |
1105 | int ret = -ESRCH; | 1105 | int ret = -ESRCH; |
1106 | 1106 | ||
1107 | if (lock_task_sighand(p, &flags)) { | 1107 | if (lock_task_sighand(p, &flags)) { |
1108 | ret = send_signal(sig, info, p, group); | 1108 | ret = send_signal(sig, info, p, group); |
1109 | unlock_task_sighand(p, &flags); | 1109 | unlock_task_sighand(p, &flags); |
1110 | } | 1110 | } |
1111 | 1111 | ||
1112 | return ret; | 1112 | return ret; |
1113 | } | 1113 | } |
1114 | 1114 | ||
1115 | /* | 1115 | /* |
1116 | * Force a signal that the process can't ignore: if necessary | 1116 | * Force a signal that the process can't ignore: if necessary |
1117 | * we unblock the signal and change any SIG_IGN to SIG_DFL. | 1117 | * we unblock the signal and change any SIG_IGN to SIG_DFL. |
1118 | * | 1118 | * |
1119 | * Note: If we unblock the signal, we always reset it to SIG_DFL, | 1119 | * Note: If we unblock the signal, we always reset it to SIG_DFL, |
1120 | * since we do not want to have a signal handler that was blocked | 1120 | * since we do not want to have a signal handler that was blocked |
1121 | * be invoked when user space had explicitly blocked it. | 1121 | * be invoked when user space had explicitly blocked it. |
1122 | * | 1122 | * |
1123 | * We don't want to have recursive SIGSEGV's etc, for example, | 1123 | * We don't want to have recursive SIGSEGV's etc, for example, |
1124 | * that is why we also clear SIGNAL_UNKILLABLE. | 1124 | * that is why we also clear SIGNAL_UNKILLABLE. |
1125 | */ | 1125 | */ |
1126 | int | 1126 | int |
1127 | force_sig_info(int sig, struct siginfo *info, struct task_struct *t) | 1127 | force_sig_info(int sig, struct siginfo *info, struct task_struct *t) |
1128 | { | 1128 | { |
1129 | unsigned long int flags; | 1129 | unsigned long int flags; |
1130 | int ret, blocked, ignored; | 1130 | int ret, blocked, ignored; |
1131 | struct k_sigaction *action; | 1131 | struct k_sigaction *action; |
1132 | 1132 | ||
1133 | spin_lock_irqsave(&t->sighand->siglock, flags); | 1133 | spin_lock_irqsave(&t->sighand->siglock, flags); |
1134 | action = &t->sighand->action[sig-1]; | 1134 | action = &t->sighand->action[sig-1]; |
1135 | ignored = action->sa.sa_handler == SIG_IGN; | 1135 | ignored = action->sa.sa_handler == SIG_IGN; |
1136 | blocked = sigismember(&t->blocked, sig); | 1136 | blocked = sigismember(&t->blocked, sig); |
1137 | if (blocked || ignored) { | 1137 | if (blocked || ignored) { |
1138 | action->sa.sa_handler = SIG_DFL; | 1138 | action->sa.sa_handler = SIG_DFL; |
1139 | if (blocked) { | 1139 | if (blocked) { |
1140 | sigdelset(&t->blocked, sig); | 1140 | sigdelset(&t->blocked, sig); |
1141 | recalc_sigpending_and_wake(t); | 1141 | recalc_sigpending_and_wake(t); |
1142 | } | 1142 | } |
1143 | } | 1143 | } |
1144 | if (action->sa.sa_handler == SIG_DFL) | 1144 | if (action->sa.sa_handler == SIG_DFL) |
1145 | t->signal->flags &= ~SIGNAL_UNKILLABLE; | 1145 | t->signal->flags &= ~SIGNAL_UNKILLABLE; |
1146 | ret = specific_send_sig_info(sig, info, t); | 1146 | ret = specific_send_sig_info(sig, info, t); |
1147 | spin_unlock_irqrestore(&t->sighand->siglock, flags); | 1147 | spin_unlock_irqrestore(&t->sighand->siglock, flags); |
1148 | 1148 | ||
1149 | return ret; | 1149 | return ret; |
1150 | } | 1150 | } |
1151 | 1151 | ||
1152 | /* | 1152 | /* |
1153 | * Nuke all other threads in the group. | 1153 | * Nuke all other threads in the group. |
1154 | */ | 1154 | */ |
1155 | int zap_other_threads(struct task_struct *p) | 1155 | int zap_other_threads(struct task_struct *p) |
1156 | { | 1156 | { |
1157 | struct task_struct *t = p; | 1157 | struct task_struct *t = p; |
1158 | int count = 0; | 1158 | int count = 0; |
1159 | 1159 | ||
1160 | p->signal->group_stop_count = 0; | 1160 | p->signal->group_stop_count = 0; |
1161 | 1161 | ||
1162 | while_each_thread(p, t) { | 1162 | while_each_thread(p, t) { |
1163 | task_clear_group_stop_pending(t); | 1163 | task_clear_group_stop_pending(t); |
1164 | count++; | 1164 | count++; |
1165 | 1165 | ||
1166 | /* Don't bother with already dead threads */ | 1166 | /* Don't bother with already dead threads */ |
1167 | if (t->exit_state) | 1167 | if (t->exit_state) |
1168 | continue; | 1168 | continue; |
1169 | sigaddset(&t->pending.signal, SIGKILL); | 1169 | sigaddset(&t->pending.signal, SIGKILL); |
1170 | signal_wake_up(t, 1); | 1170 | signal_wake_up(t, 1); |
1171 | } | 1171 | } |
1172 | 1172 | ||
1173 | return count; | 1173 | return count; |
1174 | } | 1174 | } |
1175 | 1175 | ||
1176 | struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, | 1176 | struct sighand_struct *__lock_task_sighand(struct task_struct *tsk, |
1177 | unsigned long *flags) | 1177 | unsigned long *flags) |
1178 | { | 1178 | { |
1179 | struct sighand_struct *sighand; | 1179 | struct sighand_struct *sighand; |
1180 | 1180 | ||
1181 | rcu_read_lock(); | 1181 | rcu_read_lock(); |
1182 | for (;;) { | 1182 | for (;;) { |
1183 | sighand = rcu_dereference(tsk->sighand); | 1183 | sighand = rcu_dereference(tsk->sighand); |
1184 | if (unlikely(sighand == NULL)) | 1184 | if (unlikely(sighand == NULL)) |
1185 | break; | 1185 | break; |
1186 | 1186 | ||
1187 | spin_lock_irqsave(&sighand->siglock, *flags); | 1187 | spin_lock_irqsave(&sighand->siglock, *flags); |
1188 | if (likely(sighand == tsk->sighand)) | 1188 | if (likely(sighand == tsk->sighand)) |
1189 | break; | 1189 | break; |
1190 | spin_unlock_irqrestore(&sighand->siglock, *flags); | 1190 | spin_unlock_irqrestore(&sighand->siglock, *flags); |
1191 | } | 1191 | } |
1192 | rcu_read_unlock(); | 1192 | rcu_read_unlock(); |
1193 | 1193 | ||
1194 | return sighand; | 1194 | return sighand; |
1195 | } | 1195 | } |
1196 | 1196 | ||
1197 | /* | 1197 | /* |
1198 | * send signal info to all the members of a group | 1198 | * send signal info to all the members of a group |
1199 | */ | 1199 | */ |
1200 | int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) | 1200 | int group_send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
1201 | { | 1201 | { |
1202 | int ret; | 1202 | int ret; |
1203 | 1203 | ||
1204 | rcu_read_lock(); | 1204 | rcu_read_lock(); |
1205 | ret = check_kill_permission(sig, info, p); | 1205 | ret = check_kill_permission(sig, info, p); |
1206 | rcu_read_unlock(); | 1206 | rcu_read_unlock(); |
1207 | 1207 | ||
1208 | if (!ret && sig) | 1208 | if (!ret && sig) |
1209 | ret = do_send_sig_info(sig, info, p, true); | 1209 | ret = do_send_sig_info(sig, info, p, true); |
1210 | 1210 | ||
1211 | return ret; | 1211 | return ret; |
1212 | } | 1212 | } |
1213 | 1213 | ||
1214 | /* | 1214 | /* |
1215 | * __kill_pgrp_info() sends a signal to a process group: this is what the tty | 1215 | * __kill_pgrp_info() sends a signal to a process group: this is what the tty |
1216 | * control characters do (^C, ^Z etc) | 1216 | * control characters do (^C, ^Z etc) |
1217 | * - the caller must hold at least a readlock on tasklist_lock | 1217 | * - the caller must hold at least a readlock on tasklist_lock |
1218 | */ | 1218 | */ |
1219 | int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) | 1219 | int __kill_pgrp_info(int sig, struct siginfo *info, struct pid *pgrp) |
1220 | { | 1220 | { |
1221 | struct task_struct *p = NULL; | 1221 | struct task_struct *p = NULL; |
1222 | int retval, success; | 1222 | int retval, success; |
1223 | 1223 | ||
1224 | success = 0; | 1224 | success = 0; |
1225 | retval = -ESRCH; | 1225 | retval = -ESRCH; |
1226 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { | 1226 | do_each_pid_task(pgrp, PIDTYPE_PGID, p) { |
1227 | int err = group_send_sig_info(sig, info, p); | 1227 | int err = group_send_sig_info(sig, info, p); |
1228 | success |= !err; | 1228 | success |= !err; |
1229 | retval = err; | 1229 | retval = err; |
1230 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); | 1230 | } while_each_pid_task(pgrp, PIDTYPE_PGID, p); |
1231 | return success ? 0 : retval; | 1231 | return success ? 0 : retval; |
1232 | } | 1232 | } |
1233 | 1233 | ||
1234 | int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) | 1234 | int kill_pid_info(int sig, struct siginfo *info, struct pid *pid) |
1235 | { | 1235 | { |
1236 | int error = -ESRCH; | 1236 | int error = -ESRCH; |
1237 | struct task_struct *p; | 1237 | struct task_struct *p; |
1238 | 1238 | ||
1239 | rcu_read_lock(); | 1239 | rcu_read_lock(); |
1240 | retry: | 1240 | retry: |
1241 | p = pid_task(pid, PIDTYPE_PID); | 1241 | p = pid_task(pid, PIDTYPE_PID); |
1242 | if (p) { | 1242 | if (p) { |
1243 | error = group_send_sig_info(sig, info, p); | 1243 | error = group_send_sig_info(sig, info, p); |
1244 | if (unlikely(error == -ESRCH)) | 1244 | if (unlikely(error == -ESRCH)) |
1245 | /* | 1245 | /* |
1246 | * The task was unhashed in between, try again. | 1246 | * The task was unhashed in between, try again. |
1247 | * If it is dead, pid_task() will return NULL, | 1247 | * If it is dead, pid_task() will return NULL, |
1248 | * if we race with de_thread() it will find the | 1248 | * if we race with de_thread() it will find the |
1249 | * new leader. | 1249 | * new leader. |
1250 | */ | 1250 | */ |
1251 | goto retry; | 1251 | goto retry; |
1252 | } | 1252 | } |
1253 | rcu_read_unlock(); | 1253 | rcu_read_unlock(); |
1254 | 1254 | ||
1255 | return error; | 1255 | return error; |
1256 | } | 1256 | } |
1257 | 1257 | ||
1258 | int kill_proc_info(int sig, struct siginfo *info, pid_t pid) | 1258 | int kill_proc_info(int sig, struct siginfo *info, pid_t pid) |
1259 | { | 1259 | { |
1260 | int error; | 1260 | int error; |
1261 | rcu_read_lock(); | 1261 | rcu_read_lock(); |
1262 | error = kill_pid_info(sig, info, find_vpid(pid)); | 1262 | error = kill_pid_info(sig, info, find_vpid(pid)); |
1263 | rcu_read_unlock(); | 1263 | rcu_read_unlock(); |
1264 | return error; | 1264 | return error; |
1265 | } | 1265 | } |
1266 | 1266 | ||
1267 | /* like kill_pid_info(), but doesn't use uid/euid of "current" */ | 1267 | /* like kill_pid_info(), but doesn't use uid/euid of "current" */ |
1268 | int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, | 1268 | int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid, |
1269 | uid_t uid, uid_t euid, u32 secid) | 1269 | uid_t uid, uid_t euid, u32 secid) |
1270 | { | 1270 | { |
1271 | int ret = -EINVAL; | 1271 | int ret = -EINVAL; |
1272 | struct task_struct *p; | 1272 | struct task_struct *p; |
1273 | const struct cred *pcred; | 1273 | const struct cred *pcred; |
1274 | unsigned long flags; | 1274 | unsigned long flags; |
1275 | 1275 | ||
1276 | if (!valid_signal(sig)) | 1276 | if (!valid_signal(sig)) |
1277 | return ret; | 1277 | return ret; |
1278 | 1278 | ||
1279 | rcu_read_lock(); | 1279 | rcu_read_lock(); |
1280 | p = pid_task(pid, PIDTYPE_PID); | 1280 | p = pid_task(pid, PIDTYPE_PID); |
1281 | if (!p) { | 1281 | if (!p) { |
1282 | ret = -ESRCH; | 1282 | ret = -ESRCH; |
1283 | goto out_unlock; | 1283 | goto out_unlock; |
1284 | } | 1284 | } |
1285 | pcred = __task_cred(p); | 1285 | pcred = __task_cred(p); |
1286 | if (si_fromuser(info) && | 1286 | if (si_fromuser(info) && |
1287 | euid != pcred->suid && euid != pcred->uid && | 1287 | euid != pcred->suid && euid != pcred->uid && |
1288 | uid != pcred->suid && uid != pcred->uid) { | 1288 | uid != pcred->suid && uid != pcred->uid) { |
1289 | ret = -EPERM; | 1289 | ret = -EPERM; |
1290 | goto out_unlock; | 1290 | goto out_unlock; |
1291 | } | 1291 | } |
1292 | ret = security_task_kill(p, info, sig, secid); | 1292 | ret = security_task_kill(p, info, sig, secid); |
1293 | if (ret) | 1293 | if (ret) |
1294 | goto out_unlock; | 1294 | goto out_unlock; |
1295 | 1295 | ||
1296 | if (sig) { | 1296 | if (sig) { |
1297 | if (lock_task_sighand(p, &flags)) { | 1297 | if (lock_task_sighand(p, &flags)) { |
1298 | ret = __send_signal(sig, info, p, 1, 0); | 1298 | ret = __send_signal(sig, info, p, 1, 0); |
1299 | unlock_task_sighand(p, &flags); | 1299 | unlock_task_sighand(p, &flags); |
1300 | } else | 1300 | } else |
1301 | ret = -ESRCH; | 1301 | ret = -ESRCH; |
1302 | } | 1302 | } |
1303 | out_unlock: | 1303 | out_unlock: |
1304 | rcu_read_unlock(); | 1304 | rcu_read_unlock(); |
1305 | return ret; | 1305 | return ret; |
1306 | } | 1306 | } |
1307 | EXPORT_SYMBOL_GPL(kill_pid_info_as_uid); | 1307 | EXPORT_SYMBOL_GPL(kill_pid_info_as_uid); |
1308 | 1308 | ||
1309 | /* | 1309 | /* |
1310 | * kill_something_info() interprets pid in interesting ways just like kill(2). | 1310 | * kill_something_info() interprets pid in interesting ways just like kill(2). |
1311 | * | 1311 | * |
1312 | * POSIX specifies that kill(-1,sig) is unspecified, but what we have | 1312 | * POSIX specifies that kill(-1,sig) is unspecified, but what we have |
1313 | * is probably wrong. Should make it like BSD or SYSV. | 1313 | * is probably wrong. Should make it like BSD or SYSV. |
1314 | */ | 1314 | */ |
1315 | 1315 | ||
1316 | static int kill_something_info(int sig, struct siginfo *info, pid_t pid) | 1316 | static int kill_something_info(int sig, struct siginfo *info, pid_t pid) |
1317 | { | 1317 | { |
1318 | int ret; | 1318 | int ret; |
1319 | 1319 | ||
1320 | if (pid > 0) { | 1320 | if (pid > 0) { |
1321 | rcu_read_lock(); | 1321 | rcu_read_lock(); |
1322 | ret = kill_pid_info(sig, info, find_vpid(pid)); | 1322 | ret = kill_pid_info(sig, info, find_vpid(pid)); |
1323 | rcu_read_unlock(); | 1323 | rcu_read_unlock(); |
1324 | return ret; | 1324 | return ret; |
1325 | } | 1325 | } |
1326 | 1326 | ||
1327 | read_lock(&tasklist_lock); | 1327 | read_lock(&tasklist_lock); |
1328 | if (pid != -1) { | 1328 | if (pid != -1) { |
1329 | ret = __kill_pgrp_info(sig, info, | 1329 | ret = __kill_pgrp_info(sig, info, |
1330 | pid ? find_vpid(-pid) : task_pgrp(current)); | 1330 | pid ? find_vpid(-pid) : task_pgrp(current)); |
1331 | } else { | 1331 | } else { |
1332 | int retval = 0, count = 0; | 1332 | int retval = 0, count = 0; |
1333 | struct task_struct * p; | 1333 | struct task_struct * p; |
1334 | 1334 | ||
1335 | for_each_process(p) { | 1335 | for_each_process(p) { |
1336 | if (task_pid_vnr(p) > 1 && | 1336 | if (task_pid_vnr(p) > 1 && |
1337 | !same_thread_group(p, current)) { | 1337 | !same_thread_group(p, current)) { |
1338 | int err = group_send_sig_info(sig, info, p); | 1338 | int err = group_send_sig_info(sig, info, p); |
1339 | ++count; | 1339 | ++count; |
1340 | if (err != -EPERM) | 1340 | if (err != -EPERM) |
1341 | retval = err; | 1341 | retval = err; |
1342 | } | 1342 | } |
1343 | } | 1343 | } |
1344 | ret = count ? retval : -ESRCH; | 1344 | ret = count ? retval : -ESRCH; |
1345 | } | 1345 | } |
1346 | read_unlock(&tasklist_lock); | 1346 | read_unlock(&tasklist_lock); |
1347 | 1347 | ||
1348 | return ret; | 1348 | return ret; |
1349 | } | 1349 | } |
1350 | 1350 | ||
1351 | /* | 1351 | /* |
1352 | * These are for backward compatibility with the rest of the kernel source. | 1352 | * These are for backward compatibility with the rest of the kernel source. |
1353 | */ | 1353 | */ |
1354 | 1354 | ||
1355 | int send_sig_info(int sig, struct siginfo *info, struct task_struct *p) | 1355 | int send_sig_info(int sig, struct siginfo *info, struct task_struct *p) |
1356 | { | 1356 | { |
1357 | /* | 1357 | /* |
1358 | * Make sure legacy kernel users don't send in bad values | 1358 | * Make sure legacy kernel users don't send in bad values |
1359 | * (normal paths check this in check_kill_permission). | 1359 | * (normal paths check this in check_kill_permission). |
1360 | */ | 1360 | */ |
1361 | if (!valid_signal(sig)) | 1361 | if (!valid_signal(sig)) |
1362 | return -EINVAL; | 1362 | return -EINVAL; |
1363 | 1363 | ||
1364 | return do_send_sig_info(sig, info, p, false); | 1364 | return do_send_sig_info(sig, info, p, false); |
1365 | } | 1365 | } |
1366 | 1366 | ||
1367 | #define __si_special(priv) \ | 1367 | #define __si_special(priv) \ |
1368 | ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) | 1368 | ((priv) ? SEND_SIG_PRIV : SEND_SIG_NOINFO) |
1369 | 1369 | ||
1370 | int | 1370 | int |
1371 | send_sig(int sig, struct task_struct *p, int priv) | 1371 | send_sig(int sig, struct task_struct *p, int priv) |
1372 | { | 1372 | { |
1373 | return send_sig_info(sig, __si_special(priv), p); | 1373 | return send_sig_info(sig, __si_special(priv), p); |
1374 | } | 1374 | } |
1375 | 1375 | ||
1376 | void | 1376 | void |
1377 | force_sig(int sig, struct task_struct *p) | 1377 | force_sig(int sig, struct task_struct *p) |
1378 | { | 1378 | { |
1379 | force_sig_info(sig, SEND_SIG_PRIV, p); | 1379 | force_sig_info(sig, SEND_SIG_PRIV, p); |
1380 | } | 1380 | } |
1381 | 1381 | ||
1382 | /* | 1382 | /* |
1383 | * When things go south during signal handling, we | 1383 | * When things go south during signal handling, we |
1384 | * will force a SIGSEGV. And if the signal that caused | 1384 | * will force a SIGSEGV. And if the signal that caused |
1385 | * the problem was already a SIGSEGV, we'll want to | 1385 | * the problem was already a SIGSEGV, we'll want to |
1386 | * make sure we don't even try to deliver the signal.. | 1386 | * make sure we don't even try to deliver the signal.. |
1387 | */ | 1387 | */ |
1388 | int | 1388 | int |
1389 | force_sigsegv(int sig, struct task_struct *p) | 1389 | force_sigsegv(int sig, struct task_struct *p) |
1390 | { | 1390 | { |
1391 | if (sig == SIGSEGV) { | 1391 | if (sig == SIGSEGV) { |
1392 | unsigned long flags; | 1392 | unsigned long flags; |
1393 | spin_lock_irqsave(&p->sighand->siglock, flags); | 1393 | spin_lock_irqsave(&p->sighand->siglock, flags); |
1394 | p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; | 1394 | p->sighand->action[sig - 1].sa.sa_handler = SIG_DFL; |
1395 | spin_unlock_irqrestore(&p->sighand->siglock, flags); | 1395 | spin_unlock_irqrestore(&p->sighand->siglock, flags); |
1396 | } | 1396 | } |
1397 | force_sig(SIGSEGV, p); | 1397 | force_sig(SIGSEGV, p); |
1398 | return 0; | 1398 | return 0; |
1399 | } | 1399 | } |
1400 | 1400 | ||
1401 | int kill_pgrp(struct pid *pid, int sig, int priv) | 1401 | int kill_pgrp(struct pid *pid, int sig, int priv) |
1402 | { | 1402 | { |
1403 | int ret; | 1403 | int ret; |
1404 | 1404 | ||
1405 | read_lock(&tasklist_lock); | 1405 | read_lock(&tasklist_lock); |
1406 | ret = __kill_pgrp_info(sig, __si_special(priv), pid); | 1406 | ret = __kill_pgrp_info(sig, __si_special(priv), pid); |
1407 | read_unlock(&tasklist_lock); | 1407 | read_unlock(&tasklist_lock); |
1408 | 1408 | ||
1409 | return ret; | 1409 | return ret; |
1410 | } | 1410 | } |
1411 | EXPORT_SYMBOL(kill_pgrp); | 1411 | EXPORT_SYMBOL(kill_pgrp); |
1412 | 1412 | ||
1413 | int kill_pid(struct pid *pid, int sig, int priv) | 1413 | int kill_pid(struct pid *pid, int sig, int priv) |
1414 | { | 1414 | { |
1415 | return kill_pid_info(sig, __si_special(priv), pid); | 1415 | return kill_pid_info(sig, __si_special(priv), pid); |
1416 | } | 1416 | } |
1417 | EXPORT_SYMBOL(kill_pid); | 1417 | EXPORT_SYMBOL(kill_pid); |
1418 | 1418 | ||
1419 | /* | 1419 | /* |
1420 | * These functions support sending signals using preallocated sigqueue | 1420 | * These functions support sending signals using preallocated sigqueue |
1421 | * structures. This is needed "because realtime applications cannot | 1421 | * structures. This is needed "because realtime applications cannot |
1422 | * afford to lose notifications of asynchronous events, like timer | 1422 | * afford to lose notifications of asynchronous events, like timer |
1423 | * expirations or I/O completions". In the case of POSIX Timers | 1423 | * expirations or I/O completions". In the case of POSIX Timers |
1424 | * we allocate the sigqueue structure from the timer_create. If this | 1424 | * we allocate the sigqueue structure from the timer_create. If this |
1425 | * allocation fails we are able to report the failure to the application | 1425 | * allocation fails we are able to report the failure to the application |
1426 | * with an EAGAIN error. | 1426 | * with an EAGAIN error. |
1427 | */ | 1427 | */ |
1428 | struct sigqueue *sigqueue_alloc(void) | 1428 | struct sigqueue *sigqueue_alloc(void) |
1429 | { | 1429 | { |
1430 | struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0); | 1430 | struct sigqueue *q = __sigqueue_alloc(-1, current, GFP_KERNEL, 0); |
1431 | 1431 | ||
1432 | if (q) | 1432 | if (q) |
1433 | q->flags |= SIGQUEUE_PREALLOC; | 1433 | q->flags |= SIGQUEUE_PREALLOC; |
1434 | 1434 | ||
1435 | return q; | 1435 | return q; |
1436 | } | 1436 | } |
1437 | 1437 | ||
1438 | void sigqueue_free(struct sigqueue *q) | 1438 | void sigqueue_free(struct sigqueue *q) |
1439 | { | 1439 | { |
1440 | unsigned long flags; | 1440 | unsigned long flags; |
1441 | spinlock_t *lock = ¤t->sighand->siglock; | 1441 | spinlock_t *lock = ¤t->sighand->siglock; |
1442 | 1442 | ||
1443 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); | 1443 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
1444 | /* | 1444 | /* |
1445 | * We must hold ->siglock while testing q->list | 1445 | * We must hold ->siglock while testing q->list |
1446 | * to serialize with collect_signal() or with | 1446 | * to serialize with collect_signal() or with |
1447 | * __exit_signal()->flush_sigqueue(). | 1447 | * __exit_signal()->flush_sigqueue(). |
1448 | */ | 1448 | */ |
1449 | spin_lock_irqsave(lock, flags); | 1449 | spin_lock_irqsave(lock, flags); |
1450 | q->flags &= ~SIGQUEUE_PREALLOC; | 1450 | q->flags &= ~SIGQUEUE_PREALLOC; |
1451 | /* | 1451 | /* |
1452 | * If it is queued it will be freed when dequeued, | 1452 | * If it is queued it will be freed when dequeued, |
1453 | * like the "regular" sigqueue. | 1453 | * like the "regular" sigqueue. |
1454 | */ | 1454 | */ |
1455 | if (!list_empty(&q->list)) | 1455 | if (!list_empty(&q->list)) |
1456 | q = NULL; | 1456 | q = NULL; |
1457 | spin_unlock_irqrestore(lock, flags); | 1457 | spin_unlock_irqrestore(lock, flags); |
1458 | 1458 | ||
1459 | if (q) | 1459 | if (q) |
1460 | __sigqueue_free(q); | 1460 | __sigqueue_free(q); |
1461 | } | 1461 | } |
1462 | 1462 | ||
1463 | int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) | 1463 | int send_sigqueue(struct sigqueue *q, struct task_struct *t, int group) |
1464 | { | 1464 | { |
1465 | int sig = q->info.si_signo; | 1465 | int sig = q->info.si_signo; |
1466 | struct sigpending *pending; | 1466 | struct sigpending *pending; |
1467 | unsigned long flags; | 1467 | unsigned long flags; |
1468 | int ret; | 1468 | int ret; |
1469 | 1469 | ||
1470 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); | 1470 | BUG_ON(!(q->flags & SIGQUEUE_PREALLOC)); |
1471 | 1471 | ||
1472 | ret = -1; | 1472 | ret = -1; |
1473 | if (!likely(lock_task_sighand(t, &flags))) | 1473 | if (!likely(lock_task_sighand(t, &flags))) |
1474 | goto ret; | 1474 | goto ret; |
1475 | 1475 | ||
1476 | ret = 1; /* the signal is ignored */ | 1476 | ret = 1; /* the signal is ignored */ |
1477 | if (!prepare_signal(sig, t, 0)) | 1477 | if (!prepare_signal(sig, t, 0)) |
1478 | goto out; | 1478 | goto out; |
1479 | 1479 | ||
1480 | ret = 0; | 1480 | ret = 0; |
1481 | if (unlikely(!list_empty(&q->list))) { | 1481 | if (unlikely(!list_empty(&q->list))) { |
1482 | /* | 1482 | /* |
1483 | * If an SI_TIMER entry is already queue just increment | 1483 | * If an SI_TIMER entry is already queue just increment |
1484 | * the overrun count. | 1484 | * the overrun count. |
1485 | */ | 1485 | */ |
1486 | BUG_ON(q->info.si_code != SI_TIMER); | 1486 | BUG_ON(q->info.si_code != SI_TIMER); |
1487 | q->info.si_overrun++; | 1487 | q->info.si_overrun++; |
1488 | goto out; | 1488 | goto out; |
1489 | } | 1489 | } |
1490 | q->info.si_overrun = 0; | 1490 | q->info.si_overrun = 0; |
1491 | 1491 | ||
1492 | signalfd_notify(t, sig); | 1492 | signalfd_notify(t, sig); |
1493 | pending = group ? &t->signal->shared_pending : &t->pending; | 1493 | pending = group ? &t->signal->shared_pending : &t->pending; |
1494 | list_add_tail(&q->list, &pending->list); | 1494 | list_add_tail(&q->list, &pending->list); |
1495 | sigaddset(&pending->signal, sig); | 1495 | sigaddset(&pending->signal, sig); |
1496 | complete_signal(sig, t, group); | 1496 | complete_signal(sig, t, group); |
1497 | out: | 1497 | out: |
1498 | unlock_task_sighand(t, &flags); | 1498 | unlock_task_sighand(t, &flags); |
1499 | ret: | 1499 | ret: |
1500 | return ret; | 1500 | return ret; |
1501 | } | 1501 | } |
1502 | 1502 | ||
1503 | /* | 1503 | /* |
1504 | * Let a parent know about the death of a child. | 1504 | * Let a parent know about the death of a child. |
1505 | * For a stopped/continued status change, use do_notify_parent_cldstop instead. | 1505 | * For a stopped/continued status change, use do_notify_parent_cldstop instead. |
1506 | * | 1506 | * |
1507 | * Returns -1 if our parent ignored us and so we've switched to | 1507 | * Returns -1 if our parent ignored us and so we've switched to |
1508 | * self-reaping, or else @sig. | 1508 | * self-reaping, or else @sig. |
1509 | */ | 1509 | */ |
1510 | int do_notify_parent(struct task_struct *tsk, int sig) | 1510 | int do_notify_parent(struct task_struct *tsk, int sig) |
1511 | { | 1511 | { |
1512 | struct siginfo info; | 1512 | struct siginfo info; |
1513 | unsigned long flags; | 1513 | unsigned long flags; |
1514 | struct sighand_struct *psig; | 1514 | struct sighand_struct *psig; |
1515 | int ret = sig; | 1515 | int ret = sig; |
1516 | 1516 | ||
1517 | BUG_ON(sig == -1); | 1517 | BUG_ON(sig == -1); |
1518 | 1518 | ||
1519 | /* do_notify_parent_cldstop should have been called instead. */ | 1519 | /* do_notify_parent_cldstop should have been called instead. */ |
1520 | BUG_ON(task_is_stopped_or_traced(tsk)); | 1520 | BUG_ON(task_is_stopped_or_traced(tsk)); |
1521 | 1521 | ||
1522 | BUG_ON(!task_ptrace(tsk) && | 1522 | BUG_ON(!task_ptrace(tsk) && |
1523 | (tsk->group_leader != tsk || !thread_group_empty(tsk))); | 1523 | (tsk->group_leader != tsk || !thread_group_empty(tsk))); |
1524 | 1524 | ||
1525 | info.si_signo = sig; | 1525 | info.si_signo = sig; |
1526 | info.si_errno = 0; | 1526 | info.si_errno = 0; |
1527 | /* | 1527 | /* |
1528 | * we are under tasklist_lock here so our parent is tied to | 1528 | * we are under tasklist_lock here so our parent is tied to |
1529 | * us and cannot exit and release its namespace. | 1529 | * us and cannot exit and release its namespace. |
1530 | * | 1530 | * |
1531 | * the only it can is to switch its nsproxy with sys_unshare, | 1531 | * the only it can is to switch its nsproxy with sys_unshare, |
1532 | * bu uncharing pid namespaces is not allowed, so we'll always | 1532 | * bu uncharing pid namespaces is not allowed, so we'll always |
1533 | * see relevant namespace | 1533 | * see relevant namespace |
1534 | * | 1534 | * |
1535 | * write_lock() currently calls preempt_disable() which is the | 1535 | * write_lock() currently calls preempt_disable() which is the |
1536 | * same as rcu_read_lock(), but according to Oleg, this is not | 1536 | * same as rcu_read_lock(), but according to Oleg, this is not |
1537 | * correct to rely on this | 1537 | * correct to rely on this |
1538 | */ | 1538 | */ |
1539 | rcu_read_lock(); | 1539 | rcu_read_lock(); |
1540 | info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); | 1540 | info.si_pid = task_pid_nr_ns(tsk, tsk->parent->nsproxy->pid_ns); |
1541 | info.si_uid = __task_cred(tsk)->uid; | 1541 | info.si_uid = __task_cred(tsk)->uid; |
1542 | rcu_read_unlock(); | 1542 | rcu_read_unlock(); |
1543 | 1543 | ||
1544 | info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime, | 1544 | info.si_utime = cputime_to_clock_t(cputime_add(tsk->utime, |
1545 | tsk->signal->utime)); | 1545 | tsk->signal->utime)); |
1546 | info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime, | 1546 | info.si_stime = cputime_to_clock_t(cputime_add(tsk->stime, |
1547 | tsk->signal->stime)); | 1547 | tsk->signal->stime)); |
1548 | 1548 | ||
1549 | info.si_status = tsk->exit_code & 0x7f; | 1549 | info.si_status = tsk->exit_code & 0x7f; |
1550 | if (tsk->exit_code & 0x80) | 1550 | if (tsk->exit_code & 0x80) |
1551 | info.si_code = CLD_DUMPED; | 1551 | info.si_code = CLD_DUMPED; |
1552 | else if (tsk->exit_code & 0x7f) | 1552 | else if (tsk->exit_code & 0x7f) |
1553 | info.si_code = CLD_KILLED; | 1553 | info.si_code = CLD_KILLED; |
1554 | else { | 1554 | else { |
1555 | info.si_code = CLD_EXITED; | 1555 | info.si_code = CLD_EXITED; |
1556 | info.si_status = tsk->exit_code >> 8; | 1556 | info.si_status = tsk->exit_code >> 8; |
1557 | } | 1557 | } |
1558 | 1558 | ||
1559 | psig = tsk->parent->sighand; | 1559 | psig = tsk->parent->sighand; |
1560 | spin_lock_irqsave(&psig->siglock, flags); | 1560 | spin_lock_irqsave(&psig->siglock, flags); |
1561 | if (!task_ptrace(tsk) && sig == SIGCHLD && | 1561 | if (!task_ptrace(tsk) && sig == SIGCHLD && |
1562 | (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || | 1562 | (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN || |
1563 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { | 1563 | (psig->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT))) { |
1564 | /* | 1564 | /* |
1565 | * We are exiting and our parent doesn't care. POSIX.1 | 1565 | * We are exiting and our parent doesn't care. POSIX.1 |
1566 | * defines special semantics for setting SIGCHLD to SIG_IGN | 1566 | * defines special semantics for setting SIGCHLD to SIG_IGN |
1567 | * or setting the SA_NOCLDWAIT flag: we should be reaped | 1567 | * or setting the SA_NOCLDWAIT flag: we should be reaped |
1568 | * automatically and not left for our parent's wait4 call. | 1568 | * automatically and not left for our parent's wait4 call. |
1569 | * Rather than having the parent do it as a magic kind of | 1569 | * Rather than having the parent do it as a magic kind of |
1570 | * signal handler, we just set this to tell do_exit that we | 1570 | * signal handler, we just set this to tell do_exit that we |
1571 | * can be cleaned up without becoming a zombie. Note that | 1571 | * can be cleaned up without becoming a zombie. Note that |
1572 | * we still call __wake_up_parent in this case, because a | 1572 | * we still call __wake_up_parent in this case, because a |
1573 | * blocked sys_wait4 might now return -ECHILD. | 1573 | * blocked sys_wait4 might now return -ECHILD. |
1574 | * | 1574 | * |
1575 | * Whether we send SIGCHLD or not for SA_NOCLDWAIT | 1575 | * Whether we send SIGCHLD or not for SA_NOCLDWAIT |
1576 | * is implementation-defined: we do (if you don't want | 1576 | * is implementation-defined: we do (if you don't want |
1577 | * it, just use SIG_IGN instead). | 1577 | * it, just use SIG_IGN instead). |
1578 | */ | 1578 | */ |
1579 | ret = tsk->exit_signal = -1; | 1579 | ret = tsk->exit_signal = -1; |
1580 | if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) | 1580 | if (psig->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) |
1581 | sig = -1; | 1581 | sig = -1; |
1582 | } | 1582 | } |
1583 | if (valid_signal(sig) && sig > 0) | 1583 | if (valid_signal(sig) && sig > 0) |
1584 | __group_send_sig_info(sig, &info, tsk->parent); | 1584 | __group_send_sig_info(sig, &info, tsk->parent); |
1585 | __wake_up_parent(tsk, tsk->parent); | 1585 | __wake_up_parent(tsk, tsk->parent); |
1586 | spin_unlock_irqrestore(&psig->siglock, flags); | 1586 | spin_unlock_irqrestore(&psig->siglock, flags); |
1587 | 1587 | ||
1588 | return ret; | 1588 | return ret; |
1589 | } | 1589 | } |
1590 | 1590 | ||
1591 | /** | 1591 | /** |
1592 | * do_notify_parent_cldstop - notify parent of stopped/continued state change | 1592 | * do_notify_parent_cldstop - notify parent of stopped/continued state change |
1593 | * @tsk: task reporting the state change | 1593 | * @tsk: task reporting the state change |
1594 | * @for_ptracer: the notification is for ptracer | 1594 | * @for_ptracer: the notification is for ptracer |
1595 | * @why: CLD_{CONTINUED|STOPPED|TRAPPED} to report | 1595 | * @why: CLD_{CONTINUED|STOPPED|TRAPPED} to report |
1596 | * | 1596 | * |
1597 | * Notify @tsk's parent that the stopped/continued state has changed. If | 1597 | * Notify @tsk's parent that the stopped/continued state has changed. If |
1598 | * @for_ptracer is %false, @tsk's group leader notifies to its real parent. | 1598 | * @for_ptracer is %false, @tsk's group leader notifies to its real parent. |
1599 | * If %true, @tsk reports to @tsk->parent which should be the ptracer. | 1599 | * If %true, @tsk reports to @tsk->parent which should be the ptracer. |
1600 | * | 1600 | * |
1601 | * CONTEXT: | 1601 | * CONTEXT: |
1602 | * Must be called with tasklist_lock at least read locked. | 1602 | * Must be called with tasklist_lock at least read locked. |
1603 | */ | 1603 | */ |
1604 | static void do_notify_parent_cldstop(struct task_struct *tsk, | 1604 | static void do_notify_parent_cldstop(struct task_struct *tsk, |
1605 | bool for_ptracer, int why) | 1605 | bool for_ptracer, int why) |
1606 | { | 1606 | { |
1607 | struct siginfo info; | 1607 | struct siginfo info; |
1608 | unsigned long flags; | 1608 | unsigned long flags; |
1609 | struct task_struct *parent; | 1609 | struct task_struct *parent; |
1610 | struct sighand_struct *sighand; | 1610 | struct sighand_struct *sighand; |
1611 | 1611 | ||
1612 | if (for_ptracer) { | 1612 | if (for_ptracer) { |
1613 | parent = tsk->parent; | 1613 | parent = tsk->parent; |
1614 | } else { | 1614 | } else { |
1615 | tsk = tsk->group_leader; | 1615 | tsk = tsk->group_leader; |
1616 | parent = tsk->real_parent; | 1616 | parent = tsk->real_parent; |
1617 | } | 1617 | } |
1618 | 1618 | ||
1619 | info.si_signo = SIGCHLD; | 1619 | info.si_signo = SIGCHLD; |
1620 | info.si_errno = 0; | 1620 | info.si_errno = 0; |
1621 | /* | 1621 | /* |
1622 | * see comment in do_notify_parent() about the following 4 lines | 1622 | * see comment in do_notify_parent() about the following 4 lines |
1623 | */ | 1623 | */ |
1624 | rcu_read_lock(); | 1624 | rcu_read_lock(); |
1625 | info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns); | 1625 | info.si_pid = task_pid_nr_ns(tsk, parent->nsproxy->pid_ns); |
1626 | info.si_uid = __task_cred(tsk)->uid; | 1626 | info.si_uid = __task_cred(tsk)->uid; |
1627 | rcu_read_unlock(); | 1627 | rcu_read_unlock(); |
1628 | 1628 | ||
1629 | info.si_utime = cputime_to_clock_t(tsk->utime); | 1629 | info.si_utime = cputime_to_clock_t(tsk->utime); |
1630 | info.si_stime = cputime_to_clock_t(tsk->stime); | 1630 | info.si_stime = cputime_to_clock_t(tsk->stime); |
1631 | 1631 | ||
1632 | info.si_code = why; | 1632 | info.si_code = why; |
1633 | switch (why) { | 1633 | switch (why) { |
1634 | case CLD_CONTINUED: | 1634 | case CLD_CONTINUED: |
1635 | info.si_status = SIGCONT; | 1635 | info.si_status = SIGCONT; |
1636 | break; | 1636 | break; |
1637 | case CLD_STOPPED: | 1637 | case CLD_STOPPED: |
1638 | info.si_status = tsk->signal->group_exit_code & 0x7f; | 1638 | info.si_status = tsk->signal->group_exit_code & 0x7f; |
1639 | break; | 1639 | break; |
1640 | case CLD_TRAPPED: | 1640 | case CLD_TRAPPED: |
1641 | info.si_status = tsk->exit_code & 0x7f; | 1641 | info.si_status = tsk->exit_code & 0x7f; |
1642 | break; | 1642 | break; |
1643 | default: | 1643 | default: |
1644 | BUG(); | 1644 | BUG(); |
1645 | } | 1645 | } |
1646 | 1646 | ||
1647 | sighand = parent->sighand; | 1647 | sighand = parent->sighand; |
1648 | spin_lock_irqsave(&sighand->siglock, flags); | 1648 | spin_lock_irqsave(&sighand->siglock, flags); |
1649 | if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && | 1649 | if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && |
1650 | !(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) | 1650 | !(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) |
1651 | __group_send_sig_info(SIGCHLD, &info, parent); | 1651 | __group_send_sig_info(SIGCHLD, &info, parent); |
1652 | /* | 1652 | /* |
1653 | * Even if SIGCHLD is not generated, we must wake up wait4 calls. | 1653 | * Even if SIGCHLD is not generated, we must wake up wait4 calls. |
1654 | */ | 1654 | */ |
1655 | __wake_up_parent(tsk, parent); | 1655 | __wake_up_parent(tsk, parent); |
1656 | spin_unlock_irqrestore(&sighand->siglock, flags); | 1656 | spin_unlock_irqrestore(&sighand->siglock, flags); |
1657 | } | 1657 | } |
1658 | 1658 | ||
1659 | static inline int may_ptrace_stop(void) | 1659 | static inline int may_ptrace_stop(void) |
1660 | { | 1660 | { |
1661 | if (!likely(task_ptrace(current))) | 1661 | if (!likely(task_ptrace(current))) |
1662 | return 0; | 1662 | return 0; |
1663 | /* | 1663 | /* |
1664 | * Are we in the middle of do_coredump? | 1664 | * Are we in the middle of do_coredump? |
1665 | * If so and our tracer is also part of the coredump stopping | 1665 | * If so and our tracer is also part of the coredump stopping |
1666 | * is a deadlock situation, and pointless because our tracer | 1666 | * is a deadlock situation, and pointless because our tracer |
1667 | * is dead so don't allow us to stop. | 1667 | * is dead so don't allow us to stop. |
1668 | * If SIGKILL was already sent before the caller unlocked | 1668 | * If SIGKILL was already sent before the caller unlocked |
1669 | * ->siglock we must see ->core_state != NULL. Otherwise it | 1669 | * ->siglock we must see ->core_state != NULL. Otherwise it |
1670 | * is safe to enter schedule(). | 1670 | * is safe to enter schedule(). |
1671 | */ | 1671 | */ |
1672 | if (unlikely(current->mm->core_state) && | 1672 | if (unlikely(current->mm->core_state) && |
1673 | unlikely(current->mm == current->parent->mm)) | 1673 | unlikely(current->mm == current->parent->mm)) |
1674 | return 0; | 1674 | return 0; |
1675 | 1675 | ||
1676 | return 1; | 1676 | return 1; |
1677 | } | 1677 | } |
1678 | 1678 | ||
1679 | /* | 1679 | /* |
1680 | * Return non-zero if there is a SIGKILL that should be waking us up. | 1680 | * Return non-zero if there is a SIGKILL that should be waking us up. |
1681 | * Called with the siglock held. | 1681 | * Called with the siglock held. |
1682 | */ | 1682 | */ |
1683 | static int sigkill_pending(struct task_struct *tsk) | 1683 | static int sigkill_pending(struct task_struct *tsk) |
1684 | { | 1684 | { |
1685 | return sigismember(&tsk->pending.signal, SIGKILL) || | 1685 | return sigismember(&tsk->pending.signal, SIGKILL) || |
1686 | sigismember(&tsk->signal->shared_pending.signal, SIGKILL); | 1686 | sigismember(&tsk->signal->shared_pending.signal, SIGKILL); |
1687 | } | 1687 | } |
1688 | 1688 | ||
1689 | /* | 1689 | /* |
1690 | * Test whether the target task of the usual cldstop notification - the | 1690 | * Test whether the target task of the usual cldstop notification - the |
1691 | * real_parent of @child - is in the same group as the ptracer. | 1691 | * real_parent of @child - is in the same group as the ptracer. |
1692 | */ | 1692 | */ |
1693 | static bool real_parent_is_ptracer(struct task_struct *child) | 1693 | static bool real_parent_is_ptracer(struct task_struct *child) |
1694 | { | 1694 | { |
1695 | return same_thread_group(child->parent, child->real_parent); | 1695 | return same_thread_group(child->parent, child->real_parent); |
1696 | } | 1696 | } |
1697 | 1697 | ||
1698 | /* | 1698 | /* |
1699 | * This must be called with current->sighand->siglock held. | 1699 | * This must be called with current->sighand->siglock held. |
1700 | * | 1700 | * |
1701 | * This should be the path for all ptrace stops. | 1701 | * This should be the path for all ptrace stops. |
1702 | * We always set current->last_siginfo while stopped here. | 1702 | * We always set current->last_siginfo while stopped here. |
1703 | * That makes it a way to test a stopped process for | 1703 | * That makes it a way to test a stopped process for |
1704 | * being ptrace-stopped vs being job-control-stopped. | 1704 | * being ptrace-stopped vs being job-control-stopped. |
1705 | * | 1705 | * |
1706 | * If we actually decide not to stop at all because the tracer | 1706 | * If we actually decide not to stop at all because the tracer |
1707 | * is gone, we keep current->exit_code unless clear_code. | 1707 | * is gone, we keep current->exit_code unless clear_code. |
1708 | */ | 1708 | */ |
1709 | static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) | 1709 | static void ptrace_stop(int exit_code, int why, int clear_code, siginfo_t *info) |
1710 | __releases(¤t->sighand->siglock) | 1710 | __releases(¤t->sighand->siglock) |
1711 | __acquires(¤t->sighand->siglock) | 1711 | __acquires(¤t->sighand->siglock) |
1712 | { | 1712 | { |
1713 | bool gstop_done = false; | 1713 | bool gstop_done = false; |
1714 | 1714 | ||
1715 | if (arch_ptrace_stop_needed(exit_code, info)) { | 1715 | if (arch_ptrace_stop_needed(exit_code, info)) { |
1716 | /* | 1716 | /* |
1717 | * The arch code has something special to do before a | 1717 | * The arch code has something special to do before a |
1718 | * ptrace stop. This is allowed to block, e.g. for faults | 1718 | * ptrace stop. This is allowed to block, e.g. for faults |
1719 | * on user stack pages. We can't keep the siglock while | 1719 | * on user stack pages. We can't keep the siglock while |
1720 | * calling arch_ptrace_stop, so we must release it now. | 1720 | * calling arch_ptrace_stop, so we must release it now. |
1721 | * To preserve proper semantics, we must do this before | 1721 | * To preserve proper semantics, we must do this before |
1722 | * any signal bookkeeping like checking group_stop_count. | 1722 | * any signal bookkeeping like checking group_stop_count. |
1723 | * Meanwhile, a SIGKILL could come in before we retake the | 1723 | * Meanwhile, a SIGKILL could come in before we retake the |
1724 | * siglock. That must prevent us from sleeping in TASK_TRACED. | 1724 | * siglock. That must prevent us from sleeping in TASK_TRACED. |
1725 | * So after regaining the lock, we must check for SIGKILL. | 1725 | * So after regaining the lock, we must check for SIGKILL. |
1726 | */ | 1726 | */ |
1727 | spin_unlock_irq(¤t->sighand->siglock); | 1727 | spin_unlock_irq(¤t->sighand->siglock); |
1728 | arch_ptrace_stop(exit_code, info); | 1728 | arch_ptrace_stop(exit_code, info); |
1729 | spin_lock_irq(¤t->sighand->siglock); | 1729 | spin_lock_irq(¤t->sighand->siglock); |
1730 | if (sigkill_pending(current)) | 1730 | if (sigkill_pending(current)) |
1731 | return; | 1731 | return; |
1732 | } | 1732 | } |
1733 | 1733 | ||
1734 | /* | 1734 | /* |
1735 | * If @why is CLD_STOPPED, we're trapping to participate in a group | 1735 | * If @why is CLD_STOPPED, we're trapping to participate in a group |
1736 | * stop. Do the bookkeeping. Note that if SIGCONT was delievered | 1736 | * stop. Do the bookkeeping. Note that if SIGCONT was delievered |
1737 | * while siglock was released for the arch hook, PENDING could be | 1737 | * while siglock was released for the arch hook, PENDING could be |
1738 | * clear now. We act as if SIGCONT is received after TASK_TRACED | 1738 | * clear now. We act as if SIGCONT is received after TASK_TRACED |
1739 | * is entered - ignore it. | 1739 | * is entered - ignore it. |
1740 | */ | 1740 | */ |
1741 | if (why == CLD_STOPPED && (current->group_stop & GROUP_STOP_PENDING)) | 1741 | if (why == CLD_STOPPED && (current->group_stop & GROUP_STOP_PENDING)) |
1742 | gstop_done = task_participate_group_stop(current); | 1742 | gstop_done = task_participate_group_stop(current); |
1743 | 1743 | ||
1744 | current->last_siginfo = info; | 1744 | current->last_siginfo = info; |
1745 | current->exit_code = exit_code; | 1745 | current->exit_code = exit_code; |
1746 | 1746 | ||
1747 | /* | 1747 | /* |
1748 | * TRACED should be visible before TRAPPING is cleared; otherwise, | 1748 | * TRACED should be visible before TRAPPING is cleared; otherwise, |
1749 | * the tracer might fail do_wait(). | 1749 | * the tracer might fail do_wait(). |
1750 | */ | 1750 | */ |
1751 | set_current_state(TASK_TRACED); | 1751 | set_current_state(TASK_TRACED); |
1752 | 1752 | ||
1753 | /* | 1753 | /* |
1754 | * We're committing to trapping. Clearing GROUP_STOP_TRAPPING and | 1754 | * We're committing to trapping. Clearing GROUP_STOP_TRAPPING and |
1755 | * transition to TASK_TRACED should be atomic with respect to | 1755 | * transition to TASK_TRACED should be atomic with respect to |
1756 | * siglock. This hsould be done after the arch hook as siglock is | 1756 | * siglock. This hsould be done after the arch hook as siglock is |
1757 | * released and regrabbed across it. | 1757 | * released and regrabbed across it. |
1758 | */ | 1758 | */ |
1759 | task_clear_group_stop_trapping(current); | 1759 | task_clear_group_stop_trapping(current); |
1760 | 1760 | ||
1761 | spin_unlock_irq(¤t->sighand->siglock); | 1761 | spin_unlock_irq(¤t->sighand->siglock); |
1762 | read_lock(&tasklist_lock); | 1762 | read_lock(&tasklist_lock); |
1763 | if (may_ptrace_stop()) { | 1763 | if (may_ptrace_stop()) { |
1764 | /* | 1764 | /* |
1765 | * Notify parents of the stop. | 1765 | * Notify parents of the stop. |
1766 | * | 1766 | * |
1767 | * While ptraced, there are two parents - the ptracer and | 1767 | * While ptraced, there are two parents - the ptracer and |
1768 | * the real_parent of the group_leader. The ptracer should | 1768 | * the real_parent of the group_leader. The ptracer should |
1769 | * know about every stop while the real parent is only | 1769 | * know about every stop while the real parent is only |
1770 | * interested in the completion of group stop. The states | 1770 | * interested in the completion of group stop. The states |
1771 | * for the two don't interact with each other. Notify | 1771 | * for the two don't interact with each other. Notify |
1772 | * separately unless they're gonna be duplicates. | 1772 | * separately unless they're gonna be duplicates. |
1773 | */ | 1773 | */ |
1774 | do_notify_parent_cldstop(current, true, why); | 1774 | do_notify_parent_cldstop(current, true, why); |
1775 | if (gstop_done && !real_parent_is_ptracer(current)) | 1775 | if (gstop_done && !real_parent_is_ptracer(current)) |
1776 | do_notify_parent_cldstop(current, false, why); | 1776 | do_notify_parent_cldstop(current, false, why); |
1777 | 1777 | ||
1778 | /* | 1778 | /* |
1779 | * Don't want to allow preemption here, because | 1779 | * Don't want to allow preemption here, because |
1780 | * sys_ptrace() needs this task to be inactive. | 1780 | * sys_ptrace() needs this task to be inactive. |
1781 | * | 1781 | * |
1782 | * XXX: implement read_unlock_no_resched(). | 1782 | * XXX: implement read_unlock_no_resched(). |
1783 | */ | 1783 | */ |
1784 | preempt_disable(); | 1784 | preempt_disable(); |
1785 | read_unlock(&tasklist_lock); | 1785 | read_unlock(&tasklist_lock); |
1786 | preempt_enable_no_resched(); | 1786 | preempt_enable_no_resched(); |
1787 | schedule(); | 1787 | schedule(); |
1788 | } else { | 1788 | } else { |
1789 | /* | 1789 | /* |
1790 | * By the time we got the lock, our tracer went away. | 1790 | * By the time we got the lock, our tracer went away. |
1791 | * Don't drop the lock yet, another tracer may come. | 1791 | * Don't drop the lock yet, another tracer may come. |
1792 | * | 1792 | * |
1793 | * If @gstop_done, the ptracer went away between group stop | 1793 | * If @gstop_done, the ptracer went away between group stop |
1794 | * completion and here. During detach, it would have set | 1794 | * completion and here. During detach, it would have set |
1795 | * GROUP_STOP_PENDING on us and we'll re-enter TASK_STOPPED | 1795 | * GROUP_STOP_PENDING on us and we'll re-enter TASK_STOPPED |
1796 | * in do_signal_stop() on return, so notifying the real | 1796 | * in do_signal_stop() on return, so notifying the real |
1797 | * parent of the group stop completion is enough. | 1797 | * parent of the group stop completion is enough. |
1798 | */ | 1798 | */ |
1799 | if (gstop_done) | 1799 | if (gstop_done) |
1800 | do_notify_parent_cldstop(current, false, why); | 1800 | do_notify_parent_cldstop(current, false, why); |
1801 | 1801 | ||
1802 | __set_current_state(TASK_RUNNING); | 1802 | __set_current_state(TASK_RUNNING); |
1803 | if (clear_code) | 1803 | if (clear_code) |
1804 | current->exit_code = 0; | 1804 | current->exit_code = 0; |
1805 | read_unlock(&tasklist_lock); | 1805 | read_unlock(&tasklist_lock); |
1806 | } | 1806 | } |
1807 | 1807 | ||
1808 | /* | 1808 | /* |
1809 | * While in TASK_TRACED, we were considered "frozen enough". | 1809 | * While in TASK_TRACED, we were considered "frozen enough". |
1810 | * Now that we woke up, it's crucial if we're supposed to be | 1810 | * Now that we woke up, it's crucial if we're supposed to be |
1811 | * frozen that we freeze now before running anything substantial. | 1811 | * frozen that we freeze now before running anything substantial. |
1812 | */ | 1812 | */ |
1813 | try_to_freeze(); | 1813 | try_to_freeze(); |
1814 | 1814 | ||
1815 | /* | 1815 | /* |
1816 | * We are back. Now reacquire the siglock before touching | 1816 | * We are back. Now reacquire the siglock before touching |
1817 | * last_siginfo, so that we are sure to have synchronized with | 1817 | * last_siginfo, so that we are sure to have synchronized with |
1818 | * any signal-sending on another CPU that wants to examine it. | 1818 | * any signal-sending on another CPU that wants to examine it. |
1819 | */ | 1819 | */ |
1820 | spin_lock_irq(¤t->sighand->siglock); | 1820 | spin_lock_irq(¤t->sighand->siglock); |
1821 | current->last_siginfo = NULL; | 1821 | current->last_siginfo = NULL; |
1822 | 1822 | ||
1823 | /* | 1823 | /* |
1824 | * Queued signals ignored us while we were stopped for tracing. | 1824 | * Queued signals ignored us while we were stopped for tracing. |
1825 | * So check for any that we should take before resuming user mode. | 1825 | * So check for any that we should take before resuming user mode. |
1826 | * This sets TIF_SIGPENDING, but never clears it. | 1826 | * This sets TIF_SIGPENDING, but never clears it. |
1827 | */ | 1827 | */ |
1828 | recalc_sigpending_tsk(current); | 1828 | recalc_sigpending_tsk(current); |
1829 | } | 1829 | } |
1830 | 1830 | ||
1831 | void ptrace_notify(int exit_code) | 1831 | void ptrace_notify(int exit_code) |
1832 | { | 1832 | { |
1833 | siginfo_t info; | 1833 | siginfo_t info; |
1834 | 1834 | ||
1835 | BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); | 1835 | BUG_ON((exit_code & (0x7f | ~0xffff)) != SIGTRAP); |
1836 | 1836 | ||
1837 | memset(&info, 0, sizeof info); | 1837 | memset(&info, 0, sizeof info); |
1838 | info.si_signo = SIGTRAP; | 1838 | info.si_signo = SIGTRAP; |
1839 | info.si_code = exit_code; | 1839 | info.si_code = exit_code; |
1840 | info.si_pid = task_pid_vnr(current); | 1840 | info.si_pid = task_pid_vnr(current); |
1841 | info.si_uid = current_uid(); | 1841 | info.si_uid = current_uid(); |
1842 | 1842 | ||
1843 | /* Let the debugger run. */ | 1843 | /* Let the debugger run. */ |
1844 | spin_lock_irq(¤t->sighand->siglock); | 1844 | spin_lock_irq(¤t->sighand->siglock); |
1845 | ptrace_stop(exit_code, CLD_TRAPPED, 1, &info); | 1845 | ptrace_stop(exit_code, CLD_TRAPPED, 1, &info); |
1846 | spin_unlock_irq(¤t->sighand->siglock); | 1846 | spin_unlock_irq(¤t->sighand->siglock); |
1847 | } | 1847 | } |
1848 | 1848 | ||
1849 | /* | 1849 | /* |
1850 | * This performs the stopping for SIGSTOP and other stop signals. | 1850 | * This performs the stopping for SIGSTOP and other stop signals. |
1851 | * We have to stop all threads in the thread group. | 1851 | * We have to stop all threads in the thread group. |
1852 | * Returns non-zero if we've actually stopped and released the siglock. | 1852 | * Returns non-zero if we've actually stopped and released the siglock. |
1853 | * Returns zero if we didn't stop and still hold the siglock. | 1853 | * Returns zero if we didn't stop and still hold the siglock. |
1854 | */ | 1854 | */ |
1855 | static int do_signal_stop(int signr) | 1855 | static int do_signal_stop(int signr) |
1856 | { | 1856 | { |
1857 | struct signal_struct *sig = current->signal; | 1857 | struct signal_struct *sig = current->signal; |
1858 | 1858 | ||
1859 | if (!(current->group_stop & GROUP_STOP_PENDING)) { | 1859 | if (!(current->group_stop & GROUP_STOP_PENDING)) { |
1860 | unsigned int gstop = GROUP_STOP_PENDING | GROUP_STOP_CONSUME; | 1860 | unsigned int gstop = GROUP_STOP_PENDING | GROUP_STOP_CONSUME; |
1861 | struct task_struct *t; | 1861 | struct task_struct *t; |
1862 | 1862 | ||
1863 | /* signr will be recorded in task->group_stop for retries */ | 1863 | /* signr will be recorded in task->group_stop for retries */ |
1864 | WARN_ON_ONCE(signr & ~GROUP_STOP_SIGMASK); | 1864 | WARN_ON_ONCE(signr & ~GROUP_STOP_SIGMASK); |
1865 | 1865 | ||
1866 | if (!likely(current->group_stop & GROUP_STOP_DEQUEUED) || | 1866 | if (!likely(current->group_stop & GROUP_STOP_DEQUEUED) || |
1867 | unlikely(signal_group_exit(sig))) | 1867 | unlikely(signal_group_exit(sig))) |
1868 | return 0; | 1868 | return 0; |
1869 | /* | 1869 | /* |
1870 | * There is no group stop already in progress. We must | 1870 | * There is no group stop already in progress. We must |
1871 | * initiate one now. | 1871 | * initiate one now. |
1872 | * | 1872 | * |
1873 | * While ptraced, a task may be resumed while group stop is | 1873 | * While ptraced, a task may be resumed while group stop is |
1874 | * still in effect and then receive a stop signal and | 1874 | * still in effect and then receive a stop signal and |
1875 | * initiate another group stop. This deviates from the | 1875 | * initiate another group stop. This deviates from the |
1876 | * usual behavior as two consecutive stop signals can't | 1876 | * usual behavior as two consecutive stop signals can't |
1877 | * cause two group stops when !ptraced. That is why we | 1877 | * cause two group stops when !ptraced. That is why we |
1878 | * also check !task_is_stopped(t) below. | 1878 | * also check !task_is_stopped(t) below. |
1879 | * | 1879 | * |
1880 | * The condition can be distinguished by testing whether | 1880 | * The condition can be distinguished by testing whether |
1881 | * SIGNAL_STOP_STOPPED is already set. Don't generate | 1881 | * SIGNAL_STOP_STOPPED is already set. Don't generate |
1882 | * group_exit_code in such case. | 1882 | * group_exit_code in such case. |
1883 | * | 1883 | * |
1884 | * This is not necessary for SIGNAL_STOP_CONTINUED because | 1884 | * This is not necessary for SIGNAL_STOP_CONTINUED because |
1885 | * an intervening stop signal is required to cause two | 1885 | * an intervening stop signal is required to cause two |
1886 | * continued events regardless of ptrace. | 1886 | * continued events regardless of ptrace. |
1887 | */ | 1887 | */ |
1888 | if (!(sig->flags & SIGNAL_STOP_STOPPED)) | 1888 | if (!(sig->flags & SIGNAL_STOP_STOPPED)) |
1889 | sig->group_exit_code = signr; | 1889 | sig->group_exit_code = signr; |
1890 | else | 1890 | else |
1891 | WARN_ON_ONCE(!task_ptrace(current)); | 1891 | WARN_ON_ONCE(!task_ptrace(current)); |
1892 | 1892 | ||
1893 | current->group_stop &= ~GROUP_STOP_SIGMASK; | 1893 | current->group_stop &= ~GROUP_STOP_SIGMASK; |
1894 | current->group_stop |= signr | gstop; | 1894 | current->group_stop |= signr | gstop; |
1895 | sig->group_stop_count = 1; | 1895 | sig->group_stop_count = 1; |
1896 | for (t = next_thread(current); t != current; | 1896 | for (t = next_thread(current); t != current; |
1897 | t = next_thread(t)) { | 1897 | t = next_thread(t)) { |
1898 | t->group_stop &= ~GROUP_STOP_SIGMASK; | 1898 | t->group_stop &= ~GROUP_STOP_SIGMASK; |
1899 | /* | 1899 | /* |
1900 | * Setting state to TASK_STOPPED for a group | 1900 | * Setting state to TASK_STOPPED for a group |
1901 | * stop is always done with the siglock held, | 1901 | * stop is always done with the siglock held, |
1902 | * so this check has no races. | 1902 | * so this check has no races. |
1903 | */ | 1903 | */ |
1904 | if (!(t->flags & PF_EXITING) && !task_is_stopped(t)) { | 1904 | if (!(t->flags & PF_EXITING) && !task_is_stopped(t)) { |
1905 | t->group_stop |= signr | gstop; | 1905 | t->group_stop |= signr | gstop; |
1906 | sig->group_stop_count++; | 1906 | sig->group_stop_count++; |
1907 | signal_wake_up(t, 0); | 1907 | signal_wake_up(t, 0); |
1908 | } | 1908 | } |
1909 | } | 1909 | } |
1910 | } | 1910 | } |
1911 | retry: | 1911 | retry: |
1912 | if (likely(!task_ptrace(current))) { | 1912 | if (likely(!task_ptrace(current))) { |
1913 | int notify = 0; | 1913 | int notify = 0; |
1914 | 1914 | ||
1915 | /* | 1915 | /* |
1916 | * If there are no other threads in the group, or if there | 1916 | * If there are no other threads in the group, or if there |
1917 | * is a group stop in progress and we are the last to stop, | 1917 | * is a group stop in progress and we are the last to stop, |
1918 | * report to the parent. | 1918 | * report to the parent. |
1919 | */ | 1919 | */ |
1920 | if (task_participate_group_stop(current)) | 1920 | if (task_participate_group_stop(current)) |
1921 | notify = CLD_STOPPED; | 1921 | notify = CLD_STOPPED; |
1922 | 1922 | ||
1923 | __set_current_state(TASK_STOPPED); | 1923 | __set_current_state(TASK_STOPPED); |
1924 | spin_unlock_irq(¤t->sighand->siglock); | 1924 | spin_unlock_irq(¤t->sighand->siglock); |
1925 | 1925 | ||
1926 | /* | 1926 | /* |
1927 | * Notify the parent of the group stop completion. Because | 1927 | * Notify the parent of the group stop completion. Because |
1928 | * we're not holding either the siglock or tasklist_lock | 1928 | * we're not holding either the siglock or tasklist_lock |
1929 | * here, ptracer may attach inbetween; however, this is for | 1929 | * here, ptracer may attach inbetween; however, this is for |
1930 | * group stop and should always be delivered to the real | 1930 | * group stop and should always be delivered to the real |
1931 | * parent of the group leader. The new ptracer will get | 1931 | * parent of the group leader. The new ptracer will get |
1932 | * its notification when this task transitions into | 1932 | * its notification when this task transitions into |
1933 | * TASK_TRACED. | 1933 | * TASK_TRACED. |
1934 | */ | 1934 | */ |
1935 | if (notify) { | 1935 | if (notify) { |
1936 | read_lock(&tasklist_lock); | 1936 | read_lock(&tasklist_lock); |
1937 | do_notify_parent_cldstop(current, false, notify); | 1937 | do_notify_parent_cldstop(current, false, notify); |
1938 | read_unlock(&tasklist_lock); | 1938 | read_unlock(&tasklist_lock); |
1939 | } | 1939 | } |
1940 | 1940 | ||
1941 | /* Now we don't run again until woken by SIGCONT or SIGKILL */ | 1941 | /* Now we don't run again until woken by SIGCONT or SIGKILL */ |
1942 | schedule(); | 1942 | schedule(); |
1943 | 1943 | ||
1944 | spin_lock_irq(¤t->sighand->siglock); | 1944 | spin_lock_irq(¤t->sighand->siglock); |
1945 | } else { | 1945 | } else { |
1946 | ptrace_stop(current->group_stop & GROUP_STOP_SIGMASK, | 1946 | ptrace_stop(current->group_stop & GROUP_STOP_SIGMASK, |
1947 | CLD_STOPPED, 0, NULL); | 1947 | CLD_STOPPED, 0, NULL); |
1948 | current->exit_code = 0; | 1948 | current->exit_code = 0; |
1949 | } | 1949 | } |
1950 | 1950 | ||
1951 | /* | 1951 | /* |
1952 | * GROUP_STOP_PENDING could be set if another group stop has | 1952 | * GROUP_STOP_PENDING could be set if another group stop has |
1953 | * started since being woken up or ptrace wants us to transit | 1953 | * started since being woken up or ptrace wants us to transit |
1954 | * between TASK_STOPPED and TRACED. Retry group stop. | 1954 | * between TASK_STOPPED and TRACED. Retry group stop. |
1955 | */ | 1955 | */ |
1956 | if (current->group_stop & GROUP_STOP_PENDING) { | 1956 | if (current->group_stop & GROUP_STOP_PENDING) { |
1957 | WARN_ON_ONCE(!(current->group_stop & GROUP_STOP_SIGMASK)); | 1957 | WARN_ON_ONCE(!(current->group_stop & GROUP_STOP_SIGMASK)); |
1958 | goto retry; | 1958 | goto retry; |
1959 | } | 1959 | } |
1960 | 1960 | ||
1961 | /* PTRACE_ATTACH might have raced with task killing, clear trapping */ | 1961 | /* PTRACE_ATTACH might have raced with task killing, clear trapping */ |
1962 | task_clear_group_stop_trapping(current); | 1962 | task_clear_group_stop_trapping(current); |
1963 | 1963 | ||
1964 | spin_unlock_irq(¤t->sighand->siglock); | 1964 | spin_unlock_irq(¤t->sighand->siglock); |
1965 | 1965 | ||
1966 | tracehook_finish_jctl(); | 1966 | tracehook_finish_jctl(); |
1967 | 1967 | ||
1968 | return 1; | 1968 | return 1; |
1969 | } | 1969 | } |
1970 | 1970 | ||
1971 | static int ptrace_signal(int signr, siginfo_t *info, | 1971 | static int ptrace_signal(int signr, siginfo_t *info, |
1972 | struct pt_regs *regs, void *cookie) | 1972 | struct pt_regs *regs, void *cookie) |
1973 | { | 1973 | { |
1974 | if (!task_ptrace(current)) | 1974 | if (!task_ptrace(current)) |
1975 | return signr; | 1975 | return signr; |
1976 | 1976 | ||
1977 | ptrace_signal_deliver(regs, cookie); | 1977 | ptrace_signal_deliver(regs, cookie); |
1978 | 1978 | ||
1979 | /* Let the debugger run. */ | 1979 | /* Let the debugger run. */ |
1980 | ptrace_stop(signr, CLD_TRAPPED, 0, info); | 1980 | ptrace_stop(signr, CLD_TRAPPED, 0, info); |
1981 | 1981 | ||
1982 | /* We're back. Did the debugger cancel the sig? */ | 1982 | /* We're back. Did the debugger cancel the sig? */ |
1983 | signr = current->exit_code; | 1983 | signr = current->exit_code; |
1984 | if (signr == 0) | 1984 | if (signr == 0) |
1985 | return signr; | 1985 | return signr; |
1986 | 1986 | ||
1987 | current->exit_code = 0; | 1987 | current->exit_code = 0; |
1988 | 1988 | ||
1989 | /* | 1989 | /* |
1990 | * Update the siginfo structure if the signal has | 1990 | * Update the siginfo structure if the signal has |
1991 | * changed. If the debugger wanted something | 1991 | * changed. If the debugger wanted something |
1992 | * specific in the siginfo structure then it should | 1992 | * specific in the siginfo structure then it should |
1993 | * have updated *info via PTRACE_SETSIGINFO. | 1993 | * have updated *info via PTRACE_SETSIGINFO. |
1994 | */ | 1994 | */ |
1995 | if (signr != info->si_signo) { | 1995 | if (signr != info->si_signo) { |
1996 | info->si_signo = signr; | 1996 | info->si_signo = signr; |
1997 | info->si_errno = 0; | 1997 | info->si_errno = 0; |
1998 | info->si_code = SI_USER; | 1998 | info->si_code = SI_USER; |
1999 | info->si_pid = task_pid_vnr(current->parent); | 1999 | info->si_pid = task_pid_vnr(current->parent); |
2000 | info->si_uid = task_uid(current->parent); | 2000 | info->si_uid = task_uid(current->parent); |
2001 | } | 2001 | } |
2002 | 2002 | ||
2003 | /* If the (new) signal is now blocked, requeue it. */ | 2003 | /* If the (new) signal is now blocked, requeue it. */ |
2004 | if (sigismember(¤t->blocked, signr)) { | 2004 | if (sigismember(¤t->blocked, signr)) { |
2005 | specific_send_sig_info(signr, info, current); | 2005 | specific_send_sig_info(signr, info, current); |
2006 | signr = 0; | 2006 | signr = 0; |
2007 | } | 2007 | } |
2008 | 2008 | ||
2009 | return signr; | 2009 | return signr; |
2010 | } | 2010 | } |
2011 | 2011 | ||
2012 | int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, | 2012 | int get_signal_to_deliver(siginfo_t *info, struct k_sigaction *return_ka, |
2013 | struct pt_regs *regs, void *cookie) | 2013 | struct pt_regs *regs, void *cookie) |
2014 | { | 2014 | { |
2015 | struct sighand_struct *sighand = current->sighand; | 2015 | struct sighand_struct *sighand = current->sighand; |
2016 | struct signal_struct *signal = current->signal; | 2016 | struct signal_struct *signal = current->signal; |
2017 | int signr; | 2017 | int signr; |
2018 | 2018 | ||
2019 | relock: | 2019 | relock: |
2020 | /* | 2020 | /* |
2021 | * We'll jump back here after any time we were stopped in TASK_STOPPED. | 2021 | * We'll jump back here after any time we were stopped in TASK_STOPPED. |
2022 | * While in TASK_STOPPED, we were considered "frozen enough". | 2022 | * While in TASK_STOPPED, we were considered "frozen enough". |
2023 | * Now that we woke up, it's crucial if we're supposed to be | 2023 | * Now that we woke up, it's crucial if we're supposed to be |
2024 | * frozen that we freeze now before running anything substantial. | 2024 | * frozen that we freeze now before running anything substantial. |
2025 | */ | 2025 | */ |
2026 | try_to_freeze(); | 2026 | try_to_freeze(); |
2027 | 2027 | ||
2028 | spin_lock_irq(&sighand->siglock); | 2028 | spin_lock_irq(&sighand->siglock); |
2029 | /* | 2029 | /* |
2030 | * Every stopped thread goes here after wakeup. Check to see if | 2030 | * Every stopped thread goes here after wakeup. Check to see if |
2031 | * we should notify the parent, prepare_signal(SIGCONT) encodes | 2031 | * we should notify the parent, prepare_signal(SIGCONT) encodes |
2032 | * the CLD_ si_code into SIGNAL_CLD_MASK bits. | 2032 | * the CLD_ si_code into SIGNAL_CLD_MASK bits. |
2033 | */ | 2033 | */ |
2034 | if (unlikely(signal->flags & SIGNAL_CLD_MASK)) { | 2034 | if (unlikely(signal->flags & SIGNAL_CLD_MASK)) { |
2035 | struct task_struct *leader; | 2035 | struct task_struct *leader; |
2036 | int why; | 2036 | int why; |
2037 | 2037 | ||
2038 | if (signal->flags & SIGNAL_CLD_CONTINUED) | 2038 | if (signal->flags & SIGNAL_CLD_CONTINUED) |
2039 | why = CLD_CONTINUED; | 2039 | why = CLD_CONTINUED; |
2040 | else | 2040 | else |
2041 | why = CLD_STOPPED; | 2041 | why = CLD_STOPPED; |
2042 | 2042 | ||
2043 | signal->flags &= ~SIGNAL_CLD_MASK; | 2043 | signal->flags &= ~SIGNAL_CLD_MASK; |
2044 | 2044 | ||
2045 | spin_unlock_irq(&sighand->siglock); | 2045 | spin_unlock_irq(&sighand->siglock); |
2046 | 2046 | ||
2047 | /* | 2047 | /* |
2048 | * Notify the parent that we're continuing. This event is | 2048 | * Notify the parent that we're continuing. This event is |
2049 | * always per-process and doesn't make whole lot of sense | 2049 | * always per-process and doesn't make whole lot of sense |
2050 | * for ptracers, who shouldn't consume the state via | 2050 | * for ptracers, who shouldn't consume the state via |
2051 | * wait(2) either, but, for backward compatibility, notify | 2051 | * wait(2) either, but, for backward compatibility, notify |
2052 | * the ptracer of the group leader too unless it's gonna be | 2052 | * the ptracer of the group leader too unless it's gonna be |
2053 | * a duplicate. | 2053 | * a duplicate. |
2054 | */ | 2054 | */ |
2055 | read_lock(&tasklist_lock); | 2055 | read_lock(&tasklist_lock); |
2056 | 2056 | ||
2057 | do_notify_parent_cldstop(current, false, why); | 2057 | do_notify_parent_cldstop(current, false, why); |
2058 | 2058 | ||
2059 | leader = current->group_leader; | 2059 | leader = current->group_leader; |
2060 | if (task_ptrace(leader) && !real_parent_is_ptracer(leader)) | 2060 | if (task_ptrace(leader) && !real_parent_is_ptracer(leader)) |
2061 | do_notify_parent_cldstop(leader, true, why); | 2061 | do_notify_parent_cldstop(leader, true, why); |
2062 | 2062 | ||
2063 | read_unlock(&tasklist_lock); | 2063 | read_unlock(&tasklist_lock); |
2064 | 2064 | ||
2065 | goto relock; | 2065 | goto relock; |
2066 | } | 2066 | } |
2067 | 2067 | ||
2068 | for (;;) { | 2068 | for (;;) { |
2069 | struct k_sigaction *ka; | 2069 | struct k_sigaction *ka; |
2070 | /* | 2070 | /* |
2071 | * Tracing can induce an artificial signal and choose sigaction. | 2071 | * Tracing can induce an artificial signal and choose sigaction. |
2072 | * The return value in @signr determines the default action, | 2072 | * The return value in @signr determines the default action, |
2073 | * but @info->si_signo is the signal number we will report. | 2073 | * but @info->si_signo is the signal number we will report. |
2074 | */ | 2074 | */ |
2075 | signr = tracehook_get_signal(current, regs, info, return_ka); | 2075 | signr = tracehook_get_signal(current, regs, info, return_ka); |
2076 | if (unlikely(signr < 0)) | 2076 | if (unlikely(signr < 0)) |
2077 | goto relock; | 2077 | goto relock; |
2078 | if (unlikely(signr != 0)) | 2078 | if (unlikely(signr != 0)) |
2079 | ka = return_ka; | 2079 | ka = return_ka; |
2080 | else { | 2080 | else { |
2081 | if (unlikely(current->group_stop & | 2081 | if (unlikely(current->group_stop & |
2082 | GROUP_STOP_PENDING) && do_signal_stop(0)) | 2082 | GROUP_STOP_PENDING) && do_signal_stop(0)) |
2083 | goto relock; | 2083 | goto relock; |
2084 | 2084 | ||
2085 | signr = dequeue_signal(current, ¤t->blocked, | 2085 | signr = dequeue_signal(current, ¤t->blocked, |
2086 | info); | 2086 | info); |
2087 | 2087 | ||
2088 | if (!signr) | 2088 | if (!signr) |
2089 | break; /* will return 0 */ | 2089 | break; /* will return 0 */ |
2090 | 2090 | ||
2091 | if (signr != SIGKILL) { | 2091 | if (signr != SIGKILL) { |
2092 | signr = ptrace_signal(signr, info, | 2092 | signr = ptrace_signal(signr, info, |
2093 | regs, cookie); | 2093 | regs, cookie); |
2094 | if (!signr) | 2094 | if (!signr) |
2095 | continue; | 2095 | continue; |
2096 | } | 2096 | } |
2097 | 2097 | ||
2098 | ka = &sighand->action[signr-1]; | 2098 | ka = &sighand->action[signr-1]; |
2099 | } | 2099 | } |
2100 | 2100 | ||
2101 | /* Trace actually delivered signals. */ | 2101 | /* Trace actually delivered signals. */ |
2102 | trace_signal_deliver(signr, info, ka); | 2102 | trace_signal_deliver(signr, info, ka); |
2103 | 2103 | ||
2104 | if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */ | 2104 | if (ka->sa.sa_handler == SIG_IGN) /* Do nothing. */ |
2105 | continue; | 2105 | continue; |
2106 | if (ka->sa.sa_handler != SIG_DFL) { | 2106 | if (ka->sa.sa_handler != SIG_DFL) { |
2107 | /* Run the handler. */ | 2107 | /* Run the handler. */ |
2108 | *return_ka = *ka; | 2108 | *return_ka = *ka; |
2109 | 2109 | ||
2110 | if (ka->sa.sa_flags & SA_ONESHOT) | 2110 | if (ka->sa.sa_flags & SA_ONESHOT) |
2111 | ka->sa.sa_handler = SIG_DFL; | 2111 | ka->sa.sa_handler = SIG_DFL; |
2112 | 2112 | ||
2113 | break; /* will return non-zero "signr" value */ | 2113 | break; /* will return non-zero "signr" value */ |
2114 | } | 2114 | } |
2115 | 2115 | ||
2116 | /* | 2116 | /* |
2117 | * Now we are doing the default action for this signal. | 2117 | * Now we are doing the default action for this signal. |
2118 | */ | 2118 | */ |
2119 | if (sig_kernel_ignore(signr)) /* Default is nothing. */ | 2119 | if (sig_kernel_ignore(signr)) /* Default is nothing. */ |
2120 | continue; | 2120 | continue; |
2121 | 2121 | ||
2122 | /* | 2122 | /* |
2123 | * Global init gets no signals it doesn't want. | 2123 | * Global init gets no signals it doesn't want. |
2124 | * Container-init gets no signals it doesn't want from same | 2124 | * Container-init gets no signals it doesn't want from same |
2125 | * container. | 2125 | * container. |
2126 | * | 2126 | * |
2127 | * Note that if global/container-init sees a sig_kernel_only() | 2127 | * Note that if global/container-init sees a sig_kernel_only() |
2128 | * signal here, the signal must have been generated internally | 2128 | * signal here, the signal must have been generated internally |
2129 | * or must have come from an ancestor namespace. In either | 2129 | * or must have come from an ancestor namespace. In either |
2130 | * case, the signal cannot be dropped. | 2130 | * case, the signal cannot be dropped. |
2131 | */ | 2131 | */ |
2132 | if (unlikely(signal->flags & SIGNAL_UNKILLABLE) && | 2132 | if (unlikely(signal->flags & SIGNAL_UNKILLABLE) && |
2133 | !sig_kernel_only(signr)) | 2133 | !sig_kernel_only(signr)) |
2134 | continue; | 2134 | continue; |
2135 | 2135 | ||
2136 | if (sig_kernel_stop(signr)) { | 2136 | if (sig_kernel_stop(signr)) { |
2137 | /* | 2137 | /* |
2138 | * The default action is to stop all threads in | 2138 | * The default action is to stop all threads in |
2139 | * the thread group. The job control signals | 2139 | * the thread group. The job control signals |
2140 | * do nothing in an orphaned pgrp, but SIGSTOP | 2140 | * do nothing in an orphaned pgrp, but SIGSTOP |
2141 | * always works. Note that siglock needs to be | 2141 | * always works. Note that siglock needs to be |
2142 | * dropped during the call to is_orphaned_pgrp() | 2142 | * dropped during the call to is_orphaned_pgrp() |
2143 | * because of lock ordering with tasklist_lock. | 2143 | * because of lock ordering with tasklist_lock. |
2144 | * This allows an intervening SIGCONT to be posted. | 2144 | * This allows an intervening SIGCONT to be posted. |
2145 | * We need to check for that and bail out if necessary. | 2145 | * We need to check for that and bail out if necessary. |
2146 | */ | 2146 | */ |
2147 | if (signr != SIGSTOP) { | 2147 | if (signr != SIGSTOP) { |
2148 | spin_unlock_irq(&sighand->siglock); | 2148 | spin_unlock_irq(&sighand->siglock); |
2149 | 2149 | ||
2150 | /* signals can be posted during this window */ | 2150 | /* signals can be posted during this window */ |
2151 | 2151 | ||
2152 | if (is_current_pgrp_orphaned()) | 2152 | if (is_current_pgrp_orphaned()) |
2153 | goto relock; | 2153 | goto relock; |
2154 | 2154 | ||
2155 | spin_lock_irq(&sighand->siglock); | 2155 | spin_lock_irq(&sighand->siglock); |
2156 | } | 2156 | } |
2157 | 2157 | ||
2158 | if (likely(do_signal_stop(info->si_signo))) { | 2158 | if (likely(do_signal_stop(info->si_signo))) { |
2159 | /* It released the siglock. */ | 2159 | /* It released the siglock. */ |
2160 | goto relock; | 2160 | goto relock; |
2161 | } | 2161 | } |
2162 | 2162 | ||
2163 | /* | 2163 | /* |
2164 | * We didn't actually stop, due to a race | 2164 | * We didn't actually stop, due to a race |
2165 | * with SIGCONT or something like that. | 2165 | * with SIGCONT or something like that. |
2166 | */ | 2166 | */ |
2167 | continue; | 2167 | continue; |
2168 | } | 2168 | } |
2169 | 2169 | ||
2170 | spin_unlock_irq(&sighand->siglock); | 2170 | spin_unlock_irq(&sighand->siglock); |
2171 | 2171 | ||
2172 | /* | 2172 | /* |
2173 | * Anything else is fatal, maybe with a core dump. | 2173 | * Anything else is fatal, maybe with a core dump. |
2174 | */ | 2174 | */ |
2175 | current->flags |= PF_SIGNALED; | 2175 | current->flags |= PF_SIGNALED; |
2176 | 2176 | ||
2177 | if (sig_kernel_coredump(signr)) { | 2177 | if (sig_kernel_coredump(signr)) { |
2178 | if (print_fatal_signals) | 2178 | if (print_fatal_signals) |
2179 | print_fatal_signal(regs, info->si_signo); | 2179 | print_fatal_signal(regs, info->si_signo); |
2180 | /* | 2180 | /* |
2181 | * If it was able to dump core, this kills all | 2181 | * If it was able to dump core, this kills all |
2182 | * other threads in the group and synchronizes with | 2182 | * other threads in the group and synchronizes with |
2183 | * their demise. If we lost the race with another | 2183 | * their demise. If we lost the race with another |
2184 | * thread getting here, it set group_exit_code | 2184 | * thread getting here, it set group_exit_code |
2185 | * first and our do_group_exit call below will use | 2185 | * first and our do_group_exit call below will use |
2186 | * that value and ignore the one we pass it. | 2186 | * that value and ignore the one we pass it. |
2187 | */ | 2187 | */ |
2188 | do_coredump(info->si_signo, info->si_signo, regs); | 2188 | do_coredump(info->si_signo, info->si_signo, regs); |
2189 | } | 2189 | } |
2190 | 2190 | ||
2191 | /* | 2191 | /* |
2192 | * Death signals, no core dump. | 2192 | * Death signals, no core dump. |
2193 | */ | 2193 | */ |
2194 | do_group_exit(info->si_signo); | 2194 | do_group_exit(info->si_signo); |
2195 | /* NOTREACHED */ | 2195 | /* NOTREACHED */ |
2196 | } | 2196 | } |
2197 | spin_unlock_irq(&sighand->siglock); | 2197 | spin_unlock_irq(&sighand->siglock); |
2198 | return signr; | 2198 | return signr; |
2199 | } | 2199 | } |
2200 | 2200 | ||
2201 | /* | 2201 | /* |
2202 | * It could be that complete_signal() picked us to notify about the | 2202 | * It could be that complete_signal() picked us to notify about the |
2203 | * group-wide signal. Other threads should be notified now to take | 2203 | * group-wide signal. Other threads should be notified now to take |
2204 | * the shared signals in @which since we will not. | 2204 | * the shared signals in @which since we will not. |
2205 | */ | 2205 | */ |
2206 | static void retarget_shared_pending(struct task_struct *tsk, sigset_t *which) | 2206 | static void retarget_shared_pending(struct task_struct *tsk, sigset_t *which) |
2207 | { | 2207 | { |
2208 | sigset_t retarget; | 2208 | sigset_t retarget; |
2209 | struct task_struct *t; | 2209 | struct task_struct *t; |
2210 | 2210 | ||
2211 | sigandsets(&retarget, &tsk->signal->shared_pending.signal, which); | 2211 | sigandsets(&retarget, &tsk->signal->shared_pending.signal, which); |
2212 | if (sigisemptyset(&retarget)) | 2212 | if (sigisemptyset(&retarget)) |
2213 | return; | 2213 | return; |
2214 | 2214 | ||
2215 | t = tsk; | 2215 | t = tsk; |
2216 | while_each_thread(tsk, t) { | 2216 | while_each_thread(tsk, t) { |
2217 | if (t->flags & PF_EXITING) | 2217 | if (t->flags & PF_EXITING) |
2218 | continue; | 2218 | continue; |
2219 | 2219 | ||
2220 | if (!has_pending_signals(&retarget, &t->blocked)) | 2220 | if (!has_pending_signals(&retarget, &t->blocked)) |
2221 | continue; | 2221 | continue; |
2222 | /* Remove the signals this thread can handle. */ | 2222 | /* Remove the signals this thread can handle. */ |
2223 | sigandsets(&retarget, &retarget, &t->blocked); | 2223 | sigandsets(&retarget, &retarget, &t->blocked); |
2224 | 2224 | ||
2225 | if (!signal_pending(t)) | 2225 | if (!signal_pending(t)) |
2226 | signal_wake_up(t, 0); | 2226 | signal_wake_up(t, 0); |
2227 | 2227 | ||
2228 | if (sigisemptyset(&retarget)) | 2228 | if (sigisemptyset(&retarget)) |
2229 | break; | 2229 | break; |
2230 | } | 2230 | } |
2231 | } | 2231 | } |
2232 | 2232 | ||
2233 | void exit_signals(struct task_struct *tsk) | 2233 | void exit_signals(struct task_struct *tsk) |
2234 | { | 2234 | { |
2235 | int group_stop = 0; | 2235 | int group_stop = 0; |
2236 | sigset_t unblocked; | 2236 | sigset_t unblocked; |
2237 | 2237 | ||
2238 | if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { | 2238 | if (thread_group_empty(tsk) || signal_group_exit(tsk->signal)) { |
2239 | tsk->flags |= PF_EXITING; | 2239 | tsk->flags |= PF_EXITING; |
2240 | return; | 2240 | return; |
2241 | } | 2241 | } |
2242 | 2242 | ||
2243 | spin_lock_irq(&tsk->sighand->siglock); | 2243 | spin_lock_irq(&tsk->sighand->siglock); |
2244 | /* | 2244 | /* |
2245 | * From now this task is not visible for group-wide signals, | 2245 | * From now this task is not visible for group-wide signals, |
2246 | * see wants_signal(), do_signal_stop(). | 2246 | * see wants_signal(), do_signal_stop(). |
2247 | */ | 2247 | */ |
2248 | tsk->flags |= PF_EXITING; | 2248 | tsk->flags |= PF_EXITING; |
2249 | if (!signal_pending(tsk)) | 2249 | if (!signal_pending(tsk)) |
2250 | goto out; | 2250 | goto out; |
2251 | 2251 | ||
2252 | unblocked = tsk->blocked; | 2252 | unblocked = tsk->blocked; |
2253 | signotset(&unblocked); | 2253 | signotset(&unblocked); |
2254 | retarget_shared_pending(tsk, &unblocked); | 2254 | retarget_shared_pending(tsk, &unblocked); |
2255 | 2255 | ||
2256 | if (unlikely(tsk->group_stop & GROUP_STOP_PENDING) && | 2256 | if (unlikely(tsk->group_stop & GROUP_STOP_PENDING) && |
2257 | task_participate_group_stop(tsk)) | 2257 | task_participate_group_stop(tsk)) |
2258 | group_stop = CLD_STOPPED; | 2258 | group_stop = CLD_STOPPED; |
2259 | out: | 2259 | out: |
2260 | spin_unlock_irq(&tsk->sighand->siglock); | 2260 | spin_unlock_irq(&tsk->sighand->siglock); |
2261 | 2261 | ||
2262 | /* | 2262 | /* |
2263 | * If group stop has completed, deliver the notification. This | 2263 | * If group stop has completed, deliver the notification. This |
2264 | * should always go to the real parent of the group leader. | 2264 | * should always go to the real parent of the group leader. |
2265 | */ | 2265 | */ |
2266 | if (unlikely(group_stop)) { | 2266 | if (unlikely(group_stop)) { |
2267 | read_lock(&tasklist_lock); | 2267 | read_lock(&tasklist_lock); |
2268 | do_notify_parent_cldstop(tsk, false, group_stop); | 2268 | do_notify_parent_cldstop(tsk, false, group_stop); |
2269 | read_unlock(&tasklist_lock); | 2269 | read_unlock(&tasklist_lock); |
2270 | } | 2270 | } |
2271 | } | 2271 | } |
2272 | 2272 | ||
2273 | EXPORT_SYMBOL(recalc_sigpending); | 2273 | EXPORT_SYMBOL(recalc_sigpending); |
2274 | EXPORT_SYMBOL_GPL(dequeue_signal); | 2274 | EXPORT_SYMBOL_GPL(dequeue_signal); |
2275 | EXPORT_SYMBOL(flush_signals); | 2275 | EXPORT_SYMBOL(flush_signals); |
2276 | EXPORT_SYMBOL(force_sig); | 2276 | EXPORT_SYMBOL(force_sig); |
2277 | EXPORT_SYMBOL(send_sig); | 2277 | EXPORT_SYMBOL(send_sig); |
2278 | EXPORT_SYMBOL(send_sig_info); | 2278 | EXPORT_SYMBOL(send_sig_info); |
2279 | EXPORT_SYMBOL(sigprocmask); | 2279 | EXPORT_SYMBOL(sigprocmask); |
2280 | EXPORT_SYMBOL(block_all_signals); | 2280 | EXPORT_SYMBOL(block_all_signals); |
2281 | EXPORT_SYMBOL(unblock_all_signals); | 2281 | EXPORT_SYMBOL(unblock_all_signals); |
2282 | 2282 | ||
2283 | 2283 | ||
2284 | /* | 2284 | /* |
2285 | * System call entry points. | 2285 | * System call entry points. |
2286 | */ | 2286 | */ |
2287 | 2287 | ||
2288 | /** | 2288 | /** |
2289 | * sys_restart_syscall - restart a system call | 2289 | * sys_restart_syscall - restart a system call |
2290 | */ | 2290 | */ |
2291 | SYSCALL_DEFINE0(restart_syscall) | 2291 | SYSCALL_DEFINE0(restart_syscall) |
2292 | { | 2292 | { |
2293 | struct restart_block *restart = ¤t_thread_info()->restart_block; | 2293 | struct restart_block *restart = ¤t_thread_info()->restart_block; |
2294 | return restart->fn(restart); | 2294 | return restart->fn(restart); |
2295 | } | 2295 | } |
2296 | 2296 | ||
2297 | long do_no_restart_syscall(struct restart_block *param) | 2297 | long do_no_restart_syscall(struct restart_block *param) |
2298 | { | 2298 | { |
2299 | return -EINTR; | 2299 | return -EINTR; |
2300 | } | 2300 | } |
2301 | 2301 | ||
2302 | static void __set_task_blocked(struct task_struct *tsk, const sigset_t *newset) | 2302 | static void __set_task_blocked(struct task_struct *tsk, const sigset_t *newset) |
2303 | { | 2303 | { |
2304 | if (signal_pending(tsk) && !thread_group_empty(tsk)) { | 2304 | if (signal_pending(tsk) && !thread_group_empty(tsk)) { |
2305 | sigset_t newblocked; | 2305 | sigset_t newblocked; |
2306 | /* A set of now blocked but previously unblocked signals. */ | 2306 | /* A set of now blocked but previously unblocked signals. */ |
2307 | sigandnsets(&newblocked, newset, ¤t->blocked); | 2307 | sigandnsets(&newblocked, newset, ¤t->blocked); |
2308 | retarget_shared_pending(tsk, &newblocked); | 2308 | retarget_shared_pending(tsk, &newblocked); |
2309 | } | 2309 | } |
2310 | tsk->blocked = *newset; | 2310 | tsk->blocked = *newset; |
2311 | recalc_sigpending(); | 2311 | recalc_sigpending(); |
2312 | } | 2312 | } |
2313 | 2313 | ||
2314 | /** | 2314 | /** |
2315 | * set_current_blocked - change current->blocked mask | 2315 | * set_current_blocked - change current->blocked mask |
2316 | * @newset: new mask | 2316 | * @newset: new mask |
2317 | * | 2317 | * |
2318 | * It is wrong to change ->blocked directly, this helper should be used | 2318 | * It is wrong to change ->blocked directly, this helper should be used |
2319 | * to ensure the process can't miss a shared signal we are going to block. | 2319 | * to ensure the process can't miss a shared signal we are going to block. |
2320 | */ | 2320 | */ |
2321 | void set_current_blocked(const sigset_t *newset) | 2321 | void set_current_blocked(const sigset_t *newset) |
2322 | { | 2322 | { |
2323 | struct task_struct *tsk = current; | 2323 | struct task_struct *tsk = current; |
2324 | 2324 | ||
2325 | spin_lock_irq(&tsk->sighand->siglock); | 2325 | spin_lock_irq(&tsk->sighand->siglock); |
2326 | __set_task_blocked(tsk, newset); | 2326 | __set_task_blocked(tsk, newset); |
2327 | spin_unlock_irq(&tsk->sighand->siglock); | 2327 | spin_unlock_irq(&tsk->sighand->siglock); |
2328 | } | 2328 | } |
2329 | 2329 | ||
2330 | /* | 2330 | /* |
2331 | * This is also useful for kernel threads that want to temporarily | 2331 | * This is also useful for kernel threads that want to temporarily |
2332 | * (or permanently) block certain signals. | 2332 | * (or permanently) block certain signals. |
2333 | * | 2333 | * |
2334 | * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel | 2334 | * NOTE! Unlike the user-mode sys_sigprocmask(), the kernel |
2335 | * interface happily blocks "unblockable" signals like SIGKILL | 2335 | * interface happily blocks "unblockable" signals like SIGKILL |
2336 | * and friends. | 2336 | * and friends. |
2337 | */ | 2337 | */ |
2338 | int sigprocmask(int how, sigset_t *set, sigset_t *oldset) | 2338 | int sigprocmask(int how, sigset_t *set, sigset_t *oldset) |
2339 | { | 2339 | { |
2340 | struct task_struct *tsk = current; | 2340 | struct task_struct *tsk = current; |
2341 | sigset_t newset; | 2341 | sigset_t newset; |
2342 | 2342 | ||
2343 | /* Lockless, only current can change ->blocked, never from irq */ | 2343 | /* Lockless, only current can change ->blocked, never from irq */ |
2344 | if (oldset) | 2344 | if (oldset) |
2345 | *oldset = tsk->blocked; | 2345 | *oldset = tsk->blocked; |
2346 | 2346 | ||
2347 | switch (how) { | 2347 | switch (how) { |
2348 | case SIG_BLOCK: | 2348 | case SIG_BLOCK: |
2349 | sigorsets(&newset, &tsk->blocked, set); | 2349 | sigorsets(&newset, &tsk->blocked, set); |
2350 | break; | 2350 | break; |
2351 | case SIG_UNBLOCK: | 2351 | case SIG_UNBLOCK: |
2352 | sigandnsets(&newset, &tsk->blocked, set); | 2352 | sigandnsets(&newset, &tsk->blocked, set); |
2353 | break; | 2353 | break; |
2354 | case SIG_SETMASK: | 2354 | case SIG_SETMASK: |
2355 | newset = *set; | 2355 | newset = *set; |
2356 | break; | 2356 | break; |
2357 | default: | 2357 | default: |
2358 | return -EINVAL; | 2358 | return -EINVAL; |
2359 | } | 2359 | } |
2360 | 2360 | ||
2361 | set_current_blocked(&newset); | 2361 | set_current_blocked(&newset); |
2362 | return 0; | 2362 | return 0; |
2363 | } | 2363 | } |
2364 | 2364 | ||
2365 | /** | 2365 | /** |
2366 | * sys_rt_sigprocmask - change the list of currently blocked signals | 2366 | * sys_rt_sigprocmask - change the list of currently blocked signals |
2367 | * @how: whether to add, remove, or set signals | 2367 | * @how: whether to add, remove, or set signals |
2368 | * @set: stores pending signals | 2368 | * @nset: stores pending signals |
2369 | * @oset: previous value of signal mask if non-null | 2369 | * @oset: previous value of signal mask if non-null |
2370 | * @sigsetsize: size of sigset_t type | 2370 | * @sigsetsize: size of sigset_t type |
2371 | */ | 2371 | */ |
2372 | SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset, | 2372 | SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset, |
2373 | sigset_t __user *, oset, size_t, sigsetsize) | 2373 | sigset_t __user *, oset, size_t, sigsetsize) |
2374 | { | 2374 | { |
2375 | sigset_t old_set, new_set; | 2375 | sigset_t old_set, new_set; |
2376 | int error; | 2376 | int error; |
2377 | 2377 | ||
2378 | /* XXX: Don't preclude handling different sized sigset_t's. */ | 2378 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
2379 | if (sigsetsize != sizeof(sigset_t)) | 2379 | if (sigsetsize != sizeof(sigset_t)) |
2380 | return -EINVAL; | 2380 | return -EINVAL; |
2381 | 2381 | ||
2382 | old_set = current->blocked; | 2382 | old_set = current->blocked; |
2383 | 2383 | ||
2384 | if (nset) { | 2384 | if (nset) { |
2385 | if (copy_from_user(&new_set, nset, sizeof(sigset_t))) | 2385 | if (copy_from_user(&new_set, nset, sizeof(sigset_t))) |
2386 | return -EFAULT; | 2386 | return -EFAULT; |
2387 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); | 2387 | sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
2388 | 2388 | ||
2389 | error = sigprocmask(how, &new_set, NULL); | 2389 | error = sigprocmask(how, &new_set, NULL); |
2390 | if (error) | 2390 | if (error) |
2391 | return error; | 2391 | return error; |
2392 | } | 2392 | } |
2393 | 2393 | ||
2394 | if (oset) { | 2394 | if (oset) { |
2395 | if (copy_to_user(oset, &old_set, sizeof(sigset_t))) | 2395 | if (copy_to_user(oset, &old_set, sizeof(sigset_t))) |
2396 | return -EFAULT; | 2396 | return -EFAULT; |
2397 | } | 2397 | } |
2398 | 2398 | ||
2399 | return 0; | 2399 | return 0; |
2400 | } | 2400 | } |
2401 | 2401 | ||
2402 | long do_sigpending(void __user *set, unsigned long sigsetsize) | 2402 | long do_sigpending(void __user *set, unsigned long sigsetsize) |
2403 | { | 2403 | { |
2404 | long error = -EINVAL; | 2404 | long error = -EINVAL; |
2405 | sigset_t pending; | 2405 | sigset_t pending; |
2406 | 2406 | ||
2407 | if (sigsetsize > sizeof(sigset_t)) | 2407 | if (sigsetsize > sizeof(sigset_t)) |
2408 | goto out; | 2408 | goto out; |
2409 | 2409 | ||
2410 | spin_lock_irq(¤t->sighand->siglock); | 2410 | spin_lock_irq(¤t->sighand->siglock); |
2411 | sigorsets(&pending, ¤t->pending.signal, | 2411 | sigorsets(&pending, ¤t->pending.signal, |
2412 | ¤t->signal->shared_pending.signal); | 2412 | ¤t->signal->shared_pending.signal); |
2413 | spin_unlock_irq(¤t->sighand->siglock); | 2413 | spin_unlock_irq(¤t->sighand->siglock); |
2414 | 2414 | ||
2415 | /* Outside the lock because only this thread touches it. */ | 2415 | /* Outside the lock because only this thread touches it. */ |
2416 | sigandsets(&pending, ¤t->blocked, &pending); | 2416 | sigandsets(&pending, ¤t->blocked, &pending); |
2417 | 2417 | ||
2418 | error = -EFAULT; | 2418 | error = -EFAULT; |
2419 | if (!copy_to_user(set, &pending, sigsetsize)) | 2419 | if (!copy_to_user(set, &pending, sigsetsize)) |
2420 | error = 0; | 2420 | error = 0; |
2421 | 2421 | ||
2422 | out: | 2422 | out: |
2423 | return error; | 2423 | return error; |
2424 | } | 2424 | } |
2425 | 2425 | ||
2426 | /** | 2426 | /** |
2427 | * sys_rt_sigpending - examine a pending signal that has been raised | 2427 | * sys_rt_sigpending - examine a pending signal that has been raised |
2428 | * while blocked | 2428 | * while blocked |
2429 | * @set: stores pending signals | 2429 | * @set: stores pending signals |
2430 | * @sigsetsize: size of sigset_t type or larger | 2430 | * @sigsetsize: size of sigset_t type or larger |
2431 | */ | 2431 | */ |
2432 | SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, set, size_t, sigsetsize) | 2432 | SYSCALL_DEFINE2(rt_sigpending, sigset_t __user *, set, size_t, sigsetsize) |
2433 | { | 2433 | { |
2434 | return do_sigpending(set, sigsetsize); | 2434 | return do_sigpending(set, sigsetsize); |
2435 | } | 2435 | } |
2436 | 2436 | ||
2437 | #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER | 2437 | #ifndef HAVE_ARCH_COPY_SIGINFO_TO_USER |
2438 | 2438 | ||
2439 | int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) | 2439 | int copy_siginfo_to_user(siginfo_t __user *to, siginfo_t *from) |
2440 | { | 2440 | { |
2441 | int err; | 2441 | int err; |
2442 | 2442 | ||
2443 | if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t))) | 2443 | if (!access_ok (VERIFY_WRITE, to, sizeof(siginfo_t))) |
2444 | return -EFAULT; | 2444 | return -EFAULT; |
2445 | if (from->si_code < 0) | 2445 | if (from->si_code < 0) |
2446 | return __copy_to_user(to, from, sizeof(siginfo_t)) | 2446 | return __copy_to_user(to, from, sizeof(siginfo_t)) |
2447 | ? -EFAULT : 0; | 2447 | ? -EFAULT : 0; |
2448 | /* | 2448 | /* |
2449 | * If you change siginfo_t structure, please be sure | 2449 | * If you change siginfo_t structure, please be sure |
2450 | * this code is fixed accordingly. | 2450 | * this code is fixed accordingly. |
2451 | * Please remember to update the signalfd_copyinfo() function | 2451 | * Please remember to update the signalfd_copyinfo() function |
2452 | * inside fs/signalfd.c too, in case siginfo_t changes. | 2452 | * inside fs/signalfd.c too, in case siginfo_t changes. |
2453 | * It should never copy any pad contained in the structure | 2453 | * It should never copy any pad contained in the structure |
2454 | * to avoid security leaks, but must copy the generic | 2454 | * to avoid security leaks, but must copy the generic |
2455 | * 3 ints plus the relevant union member. | 2455 | * 3 ints plus the relevant union member. |
2456 | */ | 2456 | */ |
2457 | err = __put_user(from->si_signo, &to->si_signo); | 2457 | err = __put_user(from->si_signo, &to->si_signo); |
2458 | err |= __put_user(from->si_errno, &to->si_errno); | 2458 | err |= __put_user(from->si_errno, &to->si_errno); |
2459 | err |= __put_user((short)from->si_code, &to->si_code); | 2459 | err |= __put_user((short)from->si_code, &to->si_code); |
2460 | switch (from->si_code & __SI_MASK) { | 2460 | switch (from->si_code & __SI_MASK) { |
2461 | case __SI_KILL: | 2461 | case __SI_KILL: |
2462 | err |= __put_user(from->si_pid, &to->si_pid); | 2462 | err |= __put_user(from->si_pid, &to->si_pid); |
2463 | err |= __put_user(from->si_uid, &to->si_uid); | 2463 | err |= __put_user(from->si_uid, &to->si_uid); |
2464 | break; | 2464 | break; |
2465 | case __SI_TIMER: | 2465 | case __SI_TIMER: |
2466 | err |= __put_user(from->si_tid, &to->si_tid); | 2466 | err |= __put_user(from->si_tid, &to->si_tid); |
2467 | err |= __put_user(from->si_overrun, &to->si_overrun); | 2467 | err |= __put_user(from->si_overrun, &to->si_overrun); |
2468 | err |= __put_user(from->si_ptr, &to->si_ptr); | 2468 | err |= __put_user(from->si_ptr, &to->si_ptr); |
2469 | break; | 2469 | break; |
2470 | case __SI_POLL: | 2470 | case __SI_POLL: |
2471 | err |= __put_user(from->si_band, &to->si_band); | 2471 | err |= __put_user(from->si_band, &to->si_band); |
2472 | err |= __put_user(from->si_fd, &to->si_fd); | 2472 | err |= __put_user(from->si_fd, &to->si_fd); |
2473 | break; | 2473 | break; |
2474 | case __SI_FAULT: | 2474 | case __SI_FAULT: |
2475 | err |= __put_user(from->si_addr, &to->si_addr); | 2475 | err |= __put_user(from->si_addr, &to->si_addr); |
2476 | #ifdef __ARCH_SI_TRAPNO | 2476 | #ifdef __ARCH_SI_TRAPNO |
2477 | err |= __put_user(from->si_trapno, &to->si_trapno); | 2477 | err |= __put_user(from->si_trapno, &to->si_trapno); |
2478 | #endif | 2478 | #endif |
2479 | #ifdef BUS_MCEERR_AO | 2479 | #ifdef BUS_MCEERR_AO |
2480 | /* | 2480 | /* |
2481 | * Other callers might not initialize the si_lsb field, | 2481 | * Other callers might not initialize the si_lsb field, |
2482 | * so check explicitly for the right codes here. | 2482 | * so check explicitly for the right codes here. |
2483 | */ | 2483 | */ |
2484 | if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO) | 2484 | if (from->si_code == BUS_MCEERR_AR || from->si_code == BUS_MCEERR_AO) |
2485 | err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb); | 2485 | err |= __put_user(from->si_addr_lsb, &to->si_addr_lsb); |
2486 | #endif | 2486 | #endif |
2487 | break; | 2487 | break; |
2488 | case __SI_CHLD: | 2488 | case __SI_CHLD: |
2489 | err |= __put_user(from->si_pid, &to->si_pid); | 2489 | err |= __put_user(from->si_pid, &to->si_pid); |
2490 | err |= __put_user(from->si_uid, &to->si_uid); | 2490 | err |= __put_user(from->si_uid, &to->si_uid); |
2491 | err |= __put_user(from->si_status, &to->si_status); | 2491 | err |= __put_user(from->si_status, &to->si_status); |
2492 | err |= __put_user(from->si_utime, &to->si_utime); | 2492 | err |= __put_user(from->si_utime, &to->si_utime); |
2493 | err |= __put_user(from->si_stime, &to->si_stime); | 2493 | err |= __put_user(from->si_stime, &to->si_stime); |
2494 | break; | 2494 | break; |
2495 | case __SI_RT: /* This is not generated by the kernel as of now. */ | 2495 | case __SI_RT: /* This is not generated by the kernel as of now. */ |
2496 | case __SI_MESGQ: /* But this is */ | 2496 | case __SI_MESGQ: /* But this is */ |
2497 | err |= __put_user(from->si_pid, &to->si_pid); | 2497 | err |= __put_user(from->si_pid, &to->si_pid); |
2498 | err |= __put_user(from->si_uid, &to->si_uid); | 2498 | err |= __put_user(from->si_uid, &to->si_uid); |
2499 | err |= __put_user(from->si_ptr, &to->si_ptr); | 2499 | err |= __put_user(from->si_ptr, &to->si_ptr); |
2500 | break; | 2500 | break; |
2501 | default: /* this is just in case for now ... */ | 2501 | default: /* this is just in case for now ... */ |
2502 | err |= __put_user(from->si_pid, &to->si_pid); | 2502 | err |= __put_user(from->si_pid, &to->si_pid); |
2503 | err |= __put_user(from->si_uid, &to->si_uid); | 2503 | err |= __put_user(from->si_uid, &to->si_uid); |
2504 | break; | 2504 | break; |
2505 | } | 2505 | } |
2506 | return err; | 2506 | return err; |
2507 | } | 2507 | } |
2508 | 2508 | ||
2509 | #endif | 2509 | #endif |
2510 | 2510 | ||
2511 | /** | 2511 | /** |
2512 | * do_sigtimedwait - wait for queued signals specified in @which | 2512 | * do_sigtimedwait - wait for queued signals specified in @which |
2513 | * @which: queued signals to wait for | 2513 | * @which: queued signals to wait for |
2514 | * @info: if non-null, the signal's siginfo is returned here | 2514 | * @info: if non-null, the signal's siginfo is returned here |
2515 | * @ts: upper bound on process time suspension | 2515 | * @ts: upper bound on process time suspension |
2516 | */ | 2516 | */ |
2517 | int do_sigtimedwait(const sigset_t *which, siginfo_t *info, | 2517 | int do_sigtimedwait(const sigset_t *which, siginfo_t *info, |
2518 | const struct timespec *ts) | 2518 | const struct timespec *ts) |
2519 | { | 2519 | { |
2520 | struct task_struct *tsk = current; | 2520 | struct task_struct *tsk = current; |
2521 | long timeout = MAX_SCHEDULE_TIMEOUT; | 2521 | long timeout = MAX_SCHEDULE_TIMEOUT; |
2522 | sigset_t mask = *which; | 2522 | sigset_t mask = *which; |
2523 | int sig; | 2523 | int sig; |
2524 | 2524 | ||
2525 | if (ts) { | 2525 | if (ts) { |
2526 | if (!timespec_valid(ts)) | 2526 | if (!timespec_valid(ts)) |
2527 | return -EINVAL; | 2527 | return -EINVAL; |
2528 | timeout = timespec_to_jiffies(ts); | 2528 | timeout = timespec_to_jiffies(ts); |
2529 | /* | 2529 | /* |
2530 | * We can be close to the next tick, add another one | 2530 | * We can be close to the next tick, add another one |
2531 | * to ensure we will wait at least the time asked for. | 2531 | * to ensure we will wait at least the time asked for. |
2532 | */ | 2532 | */ |
2533 | if (ts->tv_sec || ts->tv_nsec) | 2533 | if (ts->tv_sec || ts->tv_nsec) |
2534 | timeout++; | 2534 | timeout++; |
2535 | } | 2535 | } |
2536 | 2536 | ||
2537 | /* | 2537 | /* |
2538 | * Invert the set of allowed signals to get those we want to block. | 2538 | * Invert the set of allowed signals to get those we want to block. |
2539 | */ | 2539 | */ |
2540 | sigdelsetmask(&mask, sigmask(SIGKILL) | sigmask(SIGSTOP)); | 2540 | sigdelsetmask(&mask, sigmask(SIGKILL) | sigmask(SIGSTOP)); |
2541 | signotset(&mask); | 2541 | signotset(&mask); |
2542 | 2542 | ||
2543 | spin_lock_irq(&tsk->sighand->siglock); | 2543 | spin_lock_irq(&tsk->sighand->siglock); |
2544 | sig = dequeue_signal(tsk, &mask, info); | 2544 | sig = dequeue_signal(tsk, &mask, info); |
2545 | if (!sig && timeout) { | 2545 | if (!sig && timeout) { |
2546 | /* | 2546 | /* |
2547 | * None ready, temporarily unblock those we're interested | 2547 | * None ready, temporarily unblock those we're interested |
2548 | * while we are sleeping in so that we'll be awakened when | 2548 | * while we are sleeping in so that we'll be awakened when |
2549 | * they arrive. Unblocking is always fine, we can avoid | 2549 | * they arrive. Unblocking is always fine, we can avoid |
2550 | * set_current_blocked(). | 2550 | * set_current_blocked(). |
2551 | */ | 2551 | */ |
2552 | tsk->real_blocked = tsk->blocked; | 2552 | tsk->real_blocked = tsk->blocked; |
2553 | sigandsets(&tsk->blocked, &tsk->blocked, &mask); | 2553 | sigandsets(&tsk->blocked, &tsk->blocked, &mask); |
2554 | recalc_sigpending(); | 2554 | recalc_sigpending(); |
2555 | spin_unlock_irq(&tsk->sighand->siglock); | 2555 | spin_unlock_irq(&tsk->sighand->siglock); |
2556 | 2556 | ||
2557 | timeout = schedule_timeout_interruptible(timeout); | 2557 | timeout = schedule_timeout_interruptible(timeout); |
2558 | 2558 | ||
2559 | spin_lock_irq(&tsk->sighand->siglock); | 2559 | spin_lock_irq(&tsk->sighand->siglock); |
2560 | __set_task_blocked(tsk, &tsk->real_blocked); | 2560 | __set_task_blocked(tsk, &tsk->real_blocked); |
2561 | siginitset(&tsk->real_blocked, 0); | 2561 | siginitset(&tsk->real_blocked, 0); |
2562 | sig = dequeue_signal(tsk, &mask, info); | 2562 | sig = dequeue_signal(tsk, &mask, info); |
2563 | } | 2563 | } |
2564 | spin_unlock_irq(&tsk->sighand->siglock); | 2564 | spin_unlock_irq(&tsk->sighand->siglock); |
2565 | 2565 | ||
2566 | if (sig) | 2566 | if (sig) |
2567 | return sig; | 2567 | return sig; |
2568 | return timeout ? -EINTR : -EAGAIN; | 2568 | return timeout ? -EINTR : -EAGAIN; |
2569 | } | 2569 | } |
2570 | 2570 | ||
2571 | /** | 2571 | /** |
2572 | * sys_rt_sigtimedwait - synchronously wait for queued signals specified | 2572 | * sys_rt_sigtimedwait - synchronously wait for queued signals specified |
2573 | * in @uthese | 2573 | * in @uthese |
2574 | * @uthese: queued signals to wait for | 2574 | * @uthese: queued signals to wait for |
2575 | * @uinfo: if non-null, the signal's siginfo is returned here | 2575 | * @uinfo: if non-null, the signal's siginfo is returned here |
2576 | * @uts: upper bound on process time suspension | 2576 | * @uts: upper bound on process time suspension |
2577 | * @sigsetsize: size of sigset_t type | 2577 | * @sigsetsize: size of sigset_t type |
2578 | */ | 2578 | */ |
2579 | SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, | 2579 | SYSCALL_DEFINE4(rt_sigtimedwait, const sigset_t __user *, uthese, |
2580 | siginfo_t __user *, uinfo, const struct timespec __user *, uts, | 2580 | siginfo_t __user *, uinfo, const struct timespec __user *, uts, |
2581 | size_t, sigsetsize) | 2581 | size_t, sigsetsize) |
2582 | { | 2582 | { |
2583 | sigset_t these; | 2583 | sigset_t these; |
2584 | struct timespec ts; | 2584 | struct timespec ts; |
2585 | siginfo_t info; | 2585 | siginfo_t info; |
2586 | int ret; | 2586 | int ret; |
2587 | 2587 | ||
2588 | /* XXX: Don't preclude handling different sized sigset_t's. */ | 2588 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
2589 | if (sigsetsize != sizeof(sigset_t)) | 2589 | if (sigsetsize != sizeof(sigset_t)) |
2590 | return -EINVAL; | 2590 | return -EINVAL; |
2591 | 2591 | ||
2592 | if (copy_from_user(&these, uthese, sizeof(these))) | 2592 | if (copy_from_user(&these, uthese, sizeof(these))) |
2593 | return -EFAULT; | 2593 | return -EFAULT; |
2594 | 2594 | ||
2595 | if (uts) { | 2595 | if (uts) { |
2596 | if (copy_from_user(&ts, uts, sizeof(ts))) | 2596 | if (copy_from_user(&ts, uts, sizeof(ts))) |
2597 | return -EFAULT; | 2597 | return -EFAULT; |
2598 | } | 2598 | } |
2599 | 2599 | ||
2600 | ret = do_sigtimedwait(&these, &info, uts ? &ts : NULL); | 2600 | ret = do_sigtimedwait(&these, &info, uts ? &ts : NULL); |
2601 | 2601 | ||
2602 | if (ret > 0 && uinfo) { | 2602 | if (ret > 0 && uinfo) { |
2603 | if (copy_siginfo_to_user(uinfo, &info)) | 2603 | if (copy_siginfo_to_user(uinfo, &info)) |
2604 | ret = -EFAULT; | 2604 | ret = -EFAULT; |
2605 | } | 2605 | } |
2606 | 2606 | ||
2607 | return ret; | 2607 | return ret; |
2608 | } | 2608 | } |
2609 | 2609 | ||
2610 | /** | 2610 | /** |
2611 | * sys_kill - send a signal to a process | 2611 | * sys_kill - send a signal to a process |
2612 | * @pid: the PID of the process | 2612 | * @pid: the PID of the process |
2613 | * @sig: signal to be sent | 2613 | * @sig: signal to be sent |
2614 | */ | 2614 | */ |
2615 | SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) | 2615 | SYSCALL_DEFINE2(kill, pid_t, pid, int, sig) |
2616 | { | 2616 | { |
2617 | struct siginfo info; | 2617 | struct siginfo info; |
2618 | 2618 | ||
2619 | info.si_signo = sig; | 2619 | info.si_signo = sig; |
2620 | info.si_errno = 0; | 2620 | info.si_errno = 0; |
2621 | info.si_code = SI_USER; | 2621 | info.si_code = SI_USER; |
2622 | info.si_pid = task_tgid_vnr(current); | 2622 | info.si_pid = task_tgid_vnr(current); |
2623 | info.si_uid = current_uid(); | 2623 | info.si_uid = current_uid(); |
2624 | 2624 | ||
2625 | return kill_something_info(sig, &info, pid); | 2625 | return kill_something_info(sig, &info, pid); |
2626 | } | 2626 | } |
2627 | 2627 | ||
2628 | static int | 2628 | static int |
2629 | do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) | 2629 | do_send_specific(pid_t tgid, pid_t pid, int sig, struct siginfo *info) |
2630 | { | 2630 | { |
2631 | struct task_struct *p; | 2631 | struct task_struct *p; |
2632 | int error = -ESRCH; | 2632 | int error = -ESRCH; |
2633 | 2633 | ||
2634 | rcu_read_lock(); | 2634 | rcu_read_lock(); |
2635 | p = find_task_by_vpid(pid); | 2635 | p = find_task_by_vpid(pid); |
2636 | if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) { | 2636 | if (p && (tgid <= 0 || task_tgid_vnr(p) == tgid)) { |
2637 | error = check_kill_permission(sig, info, p); | 2637 | error = check_kill_permission(sig, info, p); |
2638 | /* | 2638 | /* |
2639 | * The null signal is a permissions and process existence | 2639 | * The null signal is a permissions and process existence |
2640 | * probe. No signal is actually delivered. | 2640 | * probe. No signal is actually delivered. |
2641 | */ | 2641 | */ |
2642 | if (!error && sig) { | 2642 | if (!error && sig) { |
2643 | error = do_send_sig_info(sig, info, p, false); | 2643 | error = do_send_sig_info(sig, info, p, false); |
2644 | /* | 2644 | /* |
2645 | * If lock_task_sighand() failed we pretend the task | 2645 | * If lock_task_sighand() failed we pretend the task |
2646 | * dies after receiving the signal. The window is tiny, | 2646 | * dies after receiving the signal. The window is tiny, |
2647 | * and the signal is private anyway. | 2647 | * and the signal is private anyway. |
2648 | */ | 2648 | */ |
2649 | if (unlikely(error == -ESRCH)) | 2649 | if (unlikely(error == -ESRCH)) |
2650 | error = 0; | 2650 | error = 0; |
2651 | } | 2651 | } |
2652 | } | 2652 | } |
2653 | rcu_read_unlock(); | 2653 | rcu_read_unlock(); |
2654 | 2654 | ||
2655 | return error; | 2655 | return error; |
2656 | } | 2656 | } |
2657 | 2657 | ||
2658 | static int do_tkill(pid_t tgid, pid_t pid, int sig) | 2658 | static int do_tkill(pid_t tgid, pid_t pid, int sig) |
2659 | { | 2659 | { |
2660 | struct siginfo info; | 2660 | struct siginfo info; |
2661 | 2661 | ||
2662 | info.si_signo = sig; | 2662 | info.si_signo = sig; |
2663 | info.si_errno = 0; | 2663 | info.si_errno = 0; |
2664 | info.si_code = SI_TKILL; | 2664 | info.si_code = SI_TKILL; |
2665 | info.si_pid = task_tgid_vnr(current); | 2665 | info.si_pid = task_tgid_vnr(current); |
2666 | info.si_uid = current_uid(); | 2666 | info.si_uid = current_uid(); |
2667 | 2667 | ||
2668 | return do_send_specific(tgid, pid, sig, &info); | 2668 | return do_send_specific(tgid, pid, sig, &info); |
2669 | } | 2669 | } |
2670 | 2670 | ||
2671 | /** | 2671 | /** |
2672 | * sys_tgkill - send signal to one specific thread | 2672 | * sys_tgkill - send signal to one specific thread |
2673 | * @tgid: the thread group ID of the thread | 2673 | * @tgid: the thread group ID of the thread |
2674 | * @pid: the PID of the thread | 2674 | * @pid: the PID of the thread |
2675 | * @sig: signal to be sent | 2675 | * @sig: signal to be sent |
2676 | * | 2676 | * |
2677 | * This syscall also checks the @tgid and returns -ESRCH even if the PID | 2677 | * This syscall also checks the @tgid and returns -ESRCH even if the PID |
2678 | * exists but it's not belonging to the target process anymore. This | 2678 | * exists but it's not belonging to the target process anymore. This |
2679 | * method solves the problem of threads exiting and PIDs getting reused. | 2679 | * method solves the problem of threads exiting and PIDs getting reused. |
2680 | */ | 2680 | */ |
2681 | SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig) | 2681 | SYSCALL_DEFINE3(tgkill, pid_t, tgid, pid_t, pid, int, sig) |
2682 | { | 2682 | { |
2683 | /* This is only valid for single tasks */ | 2683 | /* This is only valid for single tasks */ |
2684 | if (pid <= 0 || tgid <= 0) | 2684 | if (pid <= 0 || tgid <= 0) |
2685 | return -EINVAL; | 2685 | return -EINVAL; |
2686 | 2686 | ||
2687 | return do_tkill(tgid, pid, sig); | 2687 | return do_tkill(tgid, pid, sig); |
2688 | } | 2688 | } |
2689 | 2689 | ||
2690 | /** | 2690 | /** |
2691 | * sys_tkill - send signal to one specific task | 2691 | * sys_tkill - send signal to one specific task |
2692 | * @pid: the PID of the task | 2692 | * @pid: the PID of the task |
2693 | * @sig: signal to be sent | 2693 | * @sig: signal to be sent |
2694 | * | 2694 | * |
2695 | * Send a signal to only one task, even if it's a CLONE_THREAD task. | 2695 | * Send a signal to only one task, even if it's a CLONE_THREAD task. |
2696 | */ | 2696 | */ |
2697 | SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig) | 2697 | SYSCALL_DEFINE2(tkill, pid_t, pid, int, sig) |
2698 | { | 2698 | { |
2699 | /* This is only valid for single tasks */ | 2699 | /* This is only valid for single tasks */ |
2700 | if (pid <= 0) | 2700 | if (pid <= 0) |
2701 | return -EINVAL; | 2701 | return -EINVAL; |
2702 | 2702 | ||
2703 | return do_tkill(0, pid, sig); | 2703 | return do_tkill(0, pid, sig); |
2704 | } | 2704 | } |
2705 | 2705 | ||
2706 | /** | 2706 | /** |
2707 | * sys_rt_sigqueueinfo - send signal information to a signal | 2707 | * sys_rt_sigqueueinfo - send signal information to a signal |
2708 | * @pid: the PID of the thread | 2708 | * @pid: the PID of the thread |
2709 | * @sig: signal to be sent | 2709 | * @sig: signal to be sent |
2710 | * @uinfo: signal info to be sent | 2710 | * @uinfo: signal info to be sent |
2711 | */ | 2711 | */ |
2712 | SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, | 2712 | SYSCALL_DEFINE3(rt_sigqueueinfo, pid_t, pid, int, sig, |
2713 | siginfo_t __user *, uinfo) | 2713 | siginfo_t __user *, uinfo) |
2714 | { | 2714 | { |
2715 | siginfo_t info; | 2715 | siginfo_t info; |
2716 | 2716 | ||
2717 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) | 2717 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) |
2718 | return -EFAULT; | 2718 | return -EFAULT; |
2719 | 2719 | ||
2720 | /* Not even root can pretend to send signals from the kernel. | 2720 | /* Not even root can pretend to send signals from the kernel. |
2721 | * Nor can they impersonate a kill()/tgkill(), which adds source info. | 2721 | * Nor can they impersonate a kill()/tgkill(), which adds source info. |
2722 | */ | 2722 | */ |
2723 | if (info.si_code >= 0 || info.si_code == SI_TKILL) { | 2723 | if (info.si_code >= 0 || info.si_code == SI_TKILL) { |
2724 | /* We used to allow any < 0 si_code */ | 2724 | /* We used to allow any < 0 si_code */ |
2725 | WARN_ON_ONCE(info.si_code < 0); | 2725 | WARN_ON_ONCE(info.si_code < 0); |
2726 | return -EPERM; | 2726 | return -EPERM; |
2727 | } | 2727 | } |
2728 | info.si_signo = sig; | 2728 | info.si_signo = sig; |
2729 | 2729 | ||
2730 | /* POSIX.1b doesn't mention process groups. */ | 2730 | /* POSIX.1b doesn't mention process groups. */ |
2731 | return kill_proc_info(sig, &info, pid); | 2731 | return kill_proc_info(sig, &info, pid); |
2732 | } | 2732 | } |
2733 | 2733 | ||
2734 | long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) | 2734 | long do_rt_tgsigqueueinfo(pid_t tgid, pid_t pid, int sig, siginfo_t *info) |
2735 | { | 2735 | { |
2736 | /* This is only valid for single tasks */ | 2736 | /* This is only valid for single tasks */ |
2737 | if (pid <= 0 || tgid <= 0) | 2737 | if (pid <= 0 || tgid <= 0) |
2738 | return -EINVAL; | 2738 | return -EINVAL; |
2739 | 2739 | ||
2740 | /* Not even root can pretend to send signals from the kernel. | 2740 | /* Not even root can pretend to send signals from the kernel. |
2741 | * Nor can they impersonate a kill()/tgkill(), which adds source info. | 2741 | * Nor can they impersonate a kill()/tgkill(), which adds source info. |
2742 | */ | 2742 | */ |
2743 | if (info->si_code >= 0 || info->si_code == SI_TKILL) { | 2743 | if (info->si_code >= 0 || info->si_code == SI_TKILL) { |
2744 | /* We used to allow any < 0 si_code */ | 2744 | /* We used to allow any < 0 si_code */ |
2745 | WARN_ON_ONCE(info->si_code < 0); | 2745 | WARN_ON_ONCE(info->si_code < 0); |
2746 | return -EPERM; | 2746 | return -EPERM; |
2747 | } | 2747 | } |
2748 | info->si_signo = sig; | 2748 | info->si_signo = sig; |
2749 | 2749 | ||
2750 | return do_send_specific(tgid, pid, sig, info); | 2750 | return do_send_specific(tgid, pid, sig, info); |
2751 | } | 2751 | } |
2752 | 2752 | ||
2753 | SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, | 2753 | SYSCALL_DEFINE4(rt_tgsigqueueinfo, pid_t, tgid, pid_t, pid, int, sig, |
2754 | siginfo_t __user *, uinfo) | 2754 | siginfo_t __user *, uinfo) |
2755 | { | 2755 | { |
2756 | siginfo_t info; | 2756 | siginfo_t info; |
2757 | 2757 | ||
2758 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) | 2758 | if (copy_from_user(&info, uinfo, sizeof(siginfo_t))) |
2759 | return -EFAULT; | 2759 | return -EFAULT; |
2760 | 2760 | ||
2761 | return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); | 2761 | return do_rt_tgsigqueueinfo(tgid, pid, sig, &info); |
2762 | } | 2762 | } |
2763 | 2763 | ||
2764 | int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) | 2764 | int do_sigaction(int sig, struct k_sigaction *act, struct k_sigaction *oact) |
2765 | { | 2765 | { |
2766 | struct task_struct *t = current; | 2766 | struct task_struct *t = current; |
2767 | struct k_sigaction *k; | 2767 | struct k_sigaction *k; |
2768 | sigset_t mask; | 2768 | sigset_t mask; |
2769 | 2769 | ||
2770 | if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) | 2770 | if (!valid_signal(sig) || sig < 1 || (act && sig_kernel_only(sig))) |
2771 | return -EINVAL; | 2771 | return -EINVAL; |
2772 | 2772 | ||
2773 | k = &t->sighand->action[sig-1]; | 2773 | k = &t->sighand->action[sig-1]; |
2774 | 2774 | ||
2775 | spin_lock_irq(¤t->sighand->siglock); | 2775 | spin_lock_irq(¤t->sighand->siglock); |
2776 | if (oact) | 2776 | if (oact) |
2777 | *oact = *k; | 2777 | *oact = *k; |
2778 | 2778 | ||
2779 | if (act) { | 2779 | if (act) { |
2780 | sigdelsetmask(&act->sa.sa_mask, | 2780 | sigdelsetmask(&act->sa.sa_mask, |
2781 | sigmask(SIGKILL) | sigmask(SIGSTOP)); | 2781 | sigmask(SIGKILL) | sigmask(SIGSTOP)); |
2782 | *k = *act; | 2782 | *k = *act; |
2783 | /* | 2783 | /* |
2784 | * POSIX 3.3.1.3: | 2784 | * POSIX 3.3.1.3: |
2785 | * "Setting a signal action to SIG_IGN for a signal that is | 2785 | * "Setting a signal action to SIG_IGN for a signal that is |
2786 | * pending shall cause the pending signal to be discarded, | 2786 | * pending shall cause the pending signal to be discarded, |
2787 | * whether or not it is blocked." | 2787 | * whether or not it is blocked." |
2788 | * | 2788 | * |
2789 | * "Setting a signal action to SIG_DFL for a signal that is | 2789 | * "Setting a signal action to SIG_DFL for a signal that is |
2790 | * pending and whose default action is to ignore the signal | 2790 | * pending and whose default action is to ignore the signal |
2791 | * (for example, SIGCHLD), shall cause the pending signal to | 2791 | * (for example, SIGCHLD), shall cause the pending signal to |
2792 | * be discarded, whether or not it is blocked" | 2792 | * be discarded, whether or not it is blocked" |
2793 | */ | 2793 | */ |
2794 | if (sig_handler_ignored(sig_handler(t, sig), sig)) { | 2794 | if (sig_handler_ignored(sig_handler(t, sig), sig)) { |
2795 | sigemptyset(&mask); | 2795 | sigemptyset(&mask); |
2796 | sigaddset(&mask, sig); | 2796 | sigaddset(&mask, sig); |
2797 | rm_from_queue_full(&mask, &t->signal->shared_pending); | 2797 | rm_from_queue_full(&mask, &t->signal->shared_pending); |
2798 | do { | 2798 | do { |
2799 | rm_from_queue_full(&mask, &t->pending); | 2799 | rm_from_queue_full(&mask, &t->pending); |
2800 | t = next_thread(t); | 2800 | t = next_thread(t); |
2801 | } while (t != current); | 2801 | } while (t != current); |
2802 | } | 2802 | } |
2803 | } | 2803 | } |
2804 | 2804 | ||
2805 | spin_unlock_irq(¤t->sighand->siglock); | 2805 | spin_unlock_irq(¤t->sighand->siglock); |
2806 | return 0; | 2806 | return 0; |
2807 | } | 2807 | } |
2808 | 2808 | ||
2809 | int | 2809 | int |
2810 | do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp) | 2810 | do_sigaltstack (const stack_t __user *uss, stack_t __user *uoss, unsigned long sp) |
2811 | { | 2811 | { |
2812 | stack_t oss; | 2812 | stack_t oss; |
2813 | int error; | 2813 | int error; |
2814 | 2814 | ||
2815 | oss.ss_sp = (void __user *) current->sas_ss_sp; | 2815 | oss.ss_sp = (void __user *) current->sas_ss_sp; |
2816 | oss.ss_size = current->sas_ss_size; | 2816 | oss.ss_size = current->sas_ss_size; |
2817 | oss.ss_flags = sas_ss_flags(sp); | 2817 | oss.ss_flags = sas_ss_flags(sp); |
2818 | 2818 | ||
2819 | if (uss) { | 2819 | if (uss) { |
2820 | void __user *ss_sp; | 2820 | void __user *ss_sp; |
2821 | size_t ss_size; | 2821 | size_t ss_size; |
2822 | int ss_flags; | 2822 | int ss_flags; |
2823 | 2823 | ||
2824 | error = -EFAULT; | 2824 | error = -EFAULT; |
2825 | if (!access_ok(VERIFY_READ, uss, sizeof(*uss))) | 2825 | if (!access_ok(VERIFY_READ, uss, sizeof(*uss))) |
2826 | goto out; | 2826 | goto out; |
2827 | error = __get_user(ss_sp, &uss->ss_sp) | | 2827 | error = __get_user(ss_sp, &uss->ss_sp) | |
2828 | __get_user(ss_flags, &uss->ss_flags) | | 2828 | __get_user(ss_flags, &uss->ss_flags) | |
2829 | __get_user(ss_size, &uss->ss_size); | 2829 | __get_user(ss_size, &uss->ss_size); |
2830 | if (error) | 2830 | if (error) |
2831 | goto out; | 2831 | goto out; |
2832 | 2832 | ||
2833 | error = -EPERM; | 2833 | error = -EPERM; |
2834 | if (on_sig_stack(sp)) | 2834 | if (on_sig_stack(sp)) |
2835 | goto out; | 2835 | goto out; |
2836 | 2836 | ||
2837 | error = -EINVAL; | 2837 | error = -EINVAL; |
2838 | /* | 2838 | /* |
2839 | * Note - this code used to test ss_flags incorrectly: | 2839 | * Note - this code used to test ss_flags incorrectly: |
2840 | * old code may have been written using ss_flags==0 | 2840 | * old code may have been written using ss_flags==0 |
2841 | * to mean ss_flags==SS_ONSTACK (as this was the only | 2841 | * to mean ss_flags==SS_ONSTACK (as this was the only |
2842 | * way that worked) - this fix preserves that older | 2842 | * way that worked) - this fix preserves that older |
2843 | * mechanism. | 2843 | * mechanism. |
2844 | */ | 2844 | */ |
2845 | if (ss_flags != SS_DISABLE && ss_flags != SS_ONSTACK && ss_flags != 0) | 2845 | if (ss_flags != SS_DISABLE && ss_flags != SS_ONSTACK && ss_flags != 0) |
2846 | goto out; | 2846 | goto out; |
2847 | 2847 | ||
2848 | if (ss_flags == SS_DISABLE) { | 2848 | if (ss_flags == SS_DISABLE) { |
2849 | ss_size = 0; | 2849 | ss_size = 0; |
2850 | ss_sp = NULL; | 2850 | ss_sp = NULL; |
2851 | } else { | 2851 | } else { |
2852 | error = -ENOMEM; | 2852 | error = -ENOMEM; |
2853 | if (ss_size < MINSIGSTKSZ) | 2853 | if (ss_size < MINSIGSTKSZ) |
2854 | goto out; | 2854 | goto out; |
2855 | } | 2855 | } |
2856 | 2856 | ||
2857 | current->sas_ss_sp = (unsigned long) ss_sp; | 2857 | current->sas_ss_sp = (unsigned long) ss_sp; |
2858 | current->sas_ss_size = ss_size; | 2858 | current->sas_ss_size = ss_size; |
2859 | } | 2859 | } |
2860 | 2860 | ||
2861 | error = 0; | 2861 | error = 0; |
2862 | if (uoss) { | 2862 | if (uoss) { |
2863 | error = -EFAULT; | 2863 | error = -EFAULT; |
2864 | if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss))) | 2864 | if (!access_ok(VERIFY_WRITE, uoss, sizeof(*uoss))) |
2865 | goto out; | 2865 | goto out; |
2866 | error = __put_user(oss.ss_sp, &uoss->ss_sp) | | 2866 | error = __put_user(oss.ss_sp, &uoss->ss_sp) | |
2867 | __put_user(oss.ss_size, &uoss->ss_size) | | 2867 | __put_user(oss.ss_size, &uoss->ss_size) | |
2868 | __put_user(oss.ss_flags, &uoss->ss_flags); | 2868 | __put_user(oss.ss_flags, &uoss->ss_flags); |
2869 | } | 2869 | } |
2870 | 2870 | ||
2871 | out: | 2871 | out: |
2872 | return error; | 2872 | return error; |
2873 | } | 2873 | } |
2874 | 2874 | ||
2875 | #ifdef __ARCH_WANT_SYS_SIGPENDING | 2875 | #ifdef __ARCH_WANT_SYS_SIGPENDING |
2876 | 2876 | ||
2877 | /** | 2877 | /** |
2878 | * sys_sigpending - examine pending signals | 2878 | * sys_sigpending - examine pending signals |
2879 | * @set: where mask of pending signal is returned | 2879 | * @set: where mask of pending signal is returned |
2880 | */ | 2880 | */ |
2881 | SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set) | 2881 | SYSCALL_DEFINE1(sigpending, old_sigset_t __user *, set) |
2882 | { | 2882 | { |
2883 | return do_sigpending(set, sizeof(*set)); | 2883 | return do_sigpending(set, sizeof(*set)); |
2884 | } | 2884 | } |
2885 | 2885 | ||
2886 | #endif | 2886 | #endif |
2887 | 2887 | ||
2888 | #ifdef __ARCH_WANT_SYS_SIGPROCMASK | 2888 | #ifdef __ARCH_WANT_SYS_SIGPROCMASK |
2889 | /** | 2889 | /** |
2890 | * sys_sigprocmask - examine and change blocked signals | 2890 | * sys_sigprocmask - examine and change blocked signals |
2891 | * @how: whether to add, remove, or set signals | 2891 | * @how: whether to add, remove, or set signals |
2892 | * @nset: signals to add or remove (if non-null) | 2892 | * @nset: signals to add or remove (if non-null) |
2893 | * @oset: previous value of signal mask if non-null | 2893 | * @oset: previous value of signal mask if non-null |
2894 | * | 2894 | * |
2895 | * Some platforms have their own version with special arguments; | 2895 | * Some platforms have their own version with special arguments; |
2896 | * others support only sys_rt_sigprocmask. | 2896 | * others support only sys_rt_sigprocmask. |
2897 | */ | 2897 | */ |
2898 | 2898 | ||
2899 | SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset, | 2899 | SYSCALL_DEFINE3(sigprocmask, int, how, old_sigset_t __user *, nset, |
2900 | old_sigset_t __user *, oset) | 2900 | old_sigset_t __user *, oset) |
2901 | { | 2901 | { |
2902 | old_sigset_t old_set, new_set; | 2902 | old_sigset_t old_set, new_set; |
2903 | sigset_t new_blocked; | 2903 | sigset_t new_blocked; |
2904 | 2904 | ||
2905 | old_set = current->blocked.sig[0]; | 2905 | old_set = current->blocked.sig[0]; |
2906 | 2906 | ||
2907 | if (nset) { | 2907 | if (nset) { |
2908 | if (copy_from_user(&new_set, nset, sizeof(*nset))) | 2908 | if (copy_from_user(&new_set, nset, sizeof(*nset))) |
2909 | return -EFAULT; | 2909 | return -EFAULT; |
2910 | new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); | 2910 | new_set &= ~(sigmask(SIGKILL) | sigmask(SIGSTOP)); |
2911 | 2911 | ||
2912 | new_blocked = current->blocked; | 2912 | new_blocked = current->blocked; |
2913 | 2913 | ||
2914 | switch (how) { | 2914 | switch (how) { |
2915 | case SIG_BLOCK: | 2915 | case SIG_BLOCK: |
2916 | sigaddsetmask(&new_blocked, new_set); | 2916 | sigaddsetmask(&new_blocked, new_set); |
2917 | break; | 2917 | break; |
2918 | case SIG_UNBLOCK: | 2918 | case SIG_UNBLOCK: |
2919 | sigdelsetmask(&new_blocked, new_set); | 2919 | sigdelsetmask(&new_blocked, new_set); |
2920 | break; | 2920 | break; |
2921 | case SIG_SETMASK: | 2921 | case SIG_SETMASK: |
2922 | new_blocked.sig[0] = new_set; | 2922 | new_blocked.sig[0] = new_set; |
2923 | break; | 2923 | break; |
2924 | default: | 2924 | default: |
2925 | return -EINVAL; | 2925 | return -EINVAL; |
2926 | } | 2926 | } |
2927 | 2927 | ||
2928 | set_current_blocked(&new_blocked); | 2928 | set_current_blocked(&new_blocked); |
2929 | } | 2929 | } |
2930 | 2930 | ||
2931 | if (oset) { | 2931 | if (oset) { |
2932 | if (copy_to_user(oset, &old_set, sizeof(*oset))) | 2932 | if (copy_to_user(oset, &old_set, sizeof(*oset))) |
2933 | return -EFAULT; | 2933 | return -EFAULT; |
2934 | } | 2934 | } |
2935 | 2935 | ||
2936 | return 0; | 2936 | return 0; |
2937 | } | 2937 | } |
2938 | #endif /* __ARCH_WANT_SYS_SIGPROCMASK */ | 2938 | #endif /* __ARCH_WANT_SYS_SIGPROCMASK */ |
2939 | 2939 | ||
2940 | #ifdef __ARCH_WANT_SYS_RT_SIGACTION | 2940 | #ifdef __ARCH_WANT_SYS_RT_SIGACTION |
2941 | /** | 2941 | /** |
2942 | * sys_rt_sigaction - alter an action taken by a process | 2942 | * sys_rt_sigaction - alter an action taken by a process |
2943 | * @sig: signal to be sent | 2943 | * @sig: signal to be sent |
2944 | * @act: new sigaction | 2944 | * @act: new sigaction |
2945 | * @oact: used to save the previous sigaction | 2945 | * @oact: used to save the previous sigaction |
2946 | * @sigsetsize: size of sigset_t type | 2946 | * @sigsetsize: size of sigset_t type |
2947 | */ | 2947 | */ |
2948 | SYSCALL_DEFINE4(rt_sigaction, int, sig, | 2948 | SYSCALL_DEFINE4(rt_sigaction, int, sig, |
2949 | const struct sigaction __user *, act, | 2949 | const struct sigaction __user *, act, |
2950 | struct sigaction __user *, oact, | 2950 | struct sigaction __user *, oact, |
2951 | size_t, sigsetsize) | 2951 | size_t, sigsetsize) |
2952 | { | 2952 | { |
2953 | struct k_sigaction new_sa, old_sa; | 2953 | struct k_sigaction new_sa, old_sa; |
2954 | int ret = -EINVAL; | 2954 | int ret = -EINVAL; |
2955 | 2955 | ||
2956 | /* XXX: Don't preclude handling different sized sigset_t's. */ | 2956 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
2957 | if (sigsetsize != sizeof(sigset_t)) | 2957 | if (sigsetsize != sizeof(sigset_t)) |
2958 | goto out; | 2958 | goto out; |
2959 | 2959 | ||
2960 | if (act) { | 2960 | if (act) { |
2961 | if (copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa))) | 2961 | if (copy_from_user(&new_sa.sa, act, sizeof(new_sa.sa))) |
2962 | return -EFAULT; | 2962 | return -EFAULT; |
2963 | } | 2963 | } |
2964 | 2964 | ||
2965 | ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); | 2965 | ret = do_sigaction(sig, act ? &new_sa : NULL, oact ? &old_sa : NULL); |
2966 | 2966 | ||
2967 | if (!ret && oact) { | 2967 | if (!ret && oact) { |
2968 | if (copy_to_user(oact, &old_sa.sa, sizeof(old_sa.sa))) | 2968 | if (copy_to_user(oact, &old_sa.sa, sizeof(old_sa.sa))) |
2969 | return -EFAULT; | 2969 | return -EFAULT; |
2970 | } | 2970 | } |
2971 | out: | 2971 | out: |
2972 | return ret; | 2972 | return ret; |
2973 | } | 2973 | } |
2974 | #endif /* __ARCH_WANT_SYS_RT_SIGACTION */ | 2974 | #endif /* __ARCH_WANT_SYS_RT_SIGACTION */ |
2975 | 2975 | ||
2976 | #ifdef __ARCH_WANT_SYS_SGETMASK | 2976 | #ifdef __ARCH_WANT_SYS_SGETMASK |
2977 | 2977 | ||
2978 | /* | 2978 | /* |
2979 | * For backwards compatibility. Functionality superseded by sigprocmask. | 2979 | * For backwards compatibility. Functionality superseded by sigprocmask. |
2980 | */ | 2980 | */ |
2981 | SYSCALL_DEFINE0(sgetmask) | 2981 | SYSCALL_DEFINE0(sgetmask) |
2982 | { | 2982 | { |
2983 | /* SMP safe */ | 2983 | /* SMP safe */ |
2984 | return current->blocked.sig[0]; | 2984 | return current->blocked.sig[0]; |
2985 | } | 2985 | } |
2986 | 2986 | ||
2987 | SYSCALL_DEFINE1(ssetmask, int, newmask) | 2987 | SYSCALL_DEFINE1(ssetmask, int, newmask) |
2988 | { | 2988 | { |
2989 | int old; | 2989 | int old; |
2990 | 2990 | ||
2991 | spin_lock_irq(¤t->sighand->siglock); | 2991 | spin_lock_irq(¤t->sighand->siglock); |
2992 | old = current->blocked.sig[0]; | 2992 | old = current->blocked.sig[0]; |
2993 | 2993 | ||
2994 | siginitset(¤t->blocked, newmask & ~(sigmask(SIGKILL)| | 2994 | siginitset(¤t->blocked, newmask & ~(sigmask(SIGKILL)| |
2995 | sigmask(SIGSTOP))); | 2995 | sigmask(SIGSTOP))); |
2996 | recalc_sigpending(); | 2996 | recalc_sigpending(); |
2997 | spin_unlock_irq(¤t->sighand->siglock); | 2997 | spin_unlock_irq(¤t->sighand->siglock); |
2998 | 2998 | ||
2999 | return old; | 2999 | return old; |
3000 | } | 3000 | } |
3001 | #endif /* __ARCH_WANT_SGETMASK */ | 3001 | #endif /* __ARCH_WANT_SGETMASK */ |
3002 | 3002 | ||
3003 | #ifdef __ARCH_WANT_SYS_SIGNAL | 3003 | #ifdef __ARCH_WANT_SYS_SIGNAL |
3004 | /* | 3004 | /* |
3005 | * For backwards compatibility. Functionality superseded by sigaction. | 3005 | * For backwards compatibility. Functionality superseded by sigaction. |
3006 | */ | 3006 | */ |
3007 | SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler) | 3007 | SYSCALL_DEFINE2(signal, int, sig, __sighandler_t, handler) |
3008 | { | 3008 | { |
3009 | struct k_sigaction new_sa, old_sa; | 3009 | struct k_sigaction new_sa, old_sa; |
3010 | int ret; | 3010 | int ret; |
3011 | 3011 | ||
3012 | new_sa.sa.sa_handler = handler; | 3012 | new_sa.sa.sa_handler = handler; |
3013 | new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK; | 3013 | new_sa.sa.sa_flags = SA_ONESHOT | SA_NOMASK; |
3014 | sigemptyset(&new_sa.sa.sa_mask); | 3014 | sigemptyset(&new_sa.sa.sa_mask); |
3015 | 3015 | ||
3016 | ret = do_sigaction(sig, &new_sa, &old_sa); | 3016 | ret = do_sigaction(sig, &new_sa, &old_sa); |
3017 | 3017 | ||
3018 | return ret ? ret : (unsigned long)old_sa.sa.sa_handler; | 3018 | return ret ? ret : (unsigned long)old_sa.sa.sa_handler; |
3019 | } | 3019 | } |
3020 | #endif /* __ARCH_WANT_SYS_SIGNAL */ | 3020 | #endif /* __ARCH_WANT_SYS_SIGNAL */ |
3021 | 3021 | ||
3022 | #ifdef __ARCH_WANT_SYS_PAUSE | 3022 | #ifdef __ARCH_WANT_SYS_PAUSE |
3023 | 3023 | ||
3024 | SYSCALL_DEFINE0(pause) | 3024 | SYSCALL_DEFINE0(pause) |
3025 | { | 3025 | { |
3026 | while (!signal_pending(current)) { | 3026 | while (!signal_pending(current)) { |
3027 | current->state = TASK_INTERRUPTIBLE; | 3027 | current->state = TASK_INTERRUPTIBLE; |
3028 | schedule(); | 3028 | schedule(); |
3029 | } | 3029 | } |
3030 | return -ERESTARTNOHAND; | 3030 | return -ERESTARTNOHAND; |
3031 | } | 3031 | } |
3032 | 3032 | ||
3033 | #endif | 3033 | #endif |
3034 | 3034 | ||
3035 | #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND | 3035 | #ifdef __ARCH_WANT_SYS_RT_SIGSUSPEND |
3036 | /** | 3036 | /** |
3037 | * sys_rt_sigsuspend - replace the signal mask for a value with the | 3037 | * sys_rt_sigsuspend - replace the signal mask for a value with the |
3038 | * @unewset value until a signal is received | 3038 | * @unewset value until a signal is received |
3039 | * @unewset: new signal mask value | 3039 | * @unewset: new signal mask value |
3040 | * @sigsetsize: size of sigset_t type | 3040 | * @sigsetsize: size of sigset_t type |
3041 | */ | 3041 | */ |
3042 | SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize) | 3042 | SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize) |
3043 | { | 3043 | { |
3044 | sigset_t newset; | 3044 | sigset_t newset; |
3045 | 3045 | ||
3046 | /* XXX: Don't preclude handling different sized sigset_t's. */ | 3046 | /* XXX: Don't preclude handling different sized sigset_t's. */ |
3047 | if (sigsetsize != sizeof(sigset_t)) | 3047 | if (sigsetsize != sizeof(sigset_t)) |
3048 | return -EINVAL; | 3048 | return -EINVAL; |
3049 | 3049 | ||
3050 | if (copy_from_user(&newset, unewset, sizeof(newset))) | 3050 | if (copy_from_user(&newset, unewset, sizeof(newset))) |
3051 | return -EFAULT; | 3051 | return -EFAULT; |
3052 | sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP)); | 3052 | sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP)); |
3053 | 3053 | ||
3054 | spin_lock_irq(¤t->sighand->siglock); | 3054 | spin_lock_irq(¤t->sighand->siglock); |
3055 | current->saved_sigmask = current->blocked; | 3055 | current->saved_sigmask = current->blocked; |
3056 | current->blocked = newset; | 3056 | current->blocked = newset; |
3057 | recalc_sigpending(); | 3057 | recalc_sigpending(); |
3058 | spin_unlock_irq(¤t->sighand->siglock); | 3058 | spin_unlock_irq(¤t->sighand->siglock); |
3059 | 3059 | ||
3060 | current->state = TASK_INTERRUPTIBLE; | 3060 | current->state = TASK_INTERRUPTIBLE; |
3061 | schedule(); | 3061 | schedule(); |
3062 | set_restore_sigmask(); | 3062 | set_restore_sigmask(); |
3063 | return -ERESTARTNOHAND; | 3063 | return -ERESTARTNOHAND; |
3064 | } | 3064 | } |
3065 | #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */ | 3065 | #endif /* __ARCH_WANT_SYS_RT_SIGSUSPEND */ |
3066 | 3066 | ||
3067 | __attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma) | 3067 | __attribute__((weak)) const char *arch_vma_name(struct vm_area_struct *vma) |
3068 | { | 3068 | { |
3069 | return NULL; | 3069 | return NULL; |
3070 | } | 3070 | } |
3071 | 3071 | ||
3072 | void __init signals_init(void) | 3072 | void __init signals_init(void) |
3073 | { | 3073 | { |
3074 | sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); | 3074 | sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC); |
3075 | } | 3075 | } |
3076 | 3076 | ||
3077 | #ifdef CONFIG_KGDB_KDB | 3077 | #ifdef CONFIG_KGDB_KDB |
3078 | #include <linux/kdb.h> | 3078 | #include <linux/kdb.h> |
3079 | /* | 3079 | /* |
3080 | * kdb_send_sig_info - Allows kdb to send signals without exposing | 3080 | * kdb_send_sig_info - Allows kdb to send signals without exposing |
3081 | * signal internals. This function checks if the required locks are | 3081 | * signal internals. This function checks if the required locks are |
3082 | * available before calling the main signal code, to avoid kdb | 3082 | * available before calling the main signal code, to avoid kdb |
3083 | * deadlocks. | 3083 | * deadlocks. |
3084 | */ | 3084 | */ |
3085 | void | 3085 | void |
3086 | kdb_send_sig_info(struct task_struct *t, struct siginfo *info) | 3086 | kdb_send_sig_info(struct task_struct *t, struct siginfo *info) |
3087 | { | 3087 | { |
3088 | static struct task_struct *kdb_prev_t; | 3088 | static struct task_struct *kdb_prev_t; |
3089 | int sig, new_t; | 3089 | int sig, new_t; |
3090 | if (!spin_trylock(&t->sighand->siglock)) { | 3090 | if (!spin_trylock(&t->sighand->siglock)) { |
3091 | kdb_printf("Can't do kill command now.\n" | 3091 | kdb_printf("Can't do kill command now.\n" |
3092 | "The sigmask lock is held somewhere else in " | 3092 | "The sigmask lock is held somewhere else in " |
3093 | "kernel, try again later\n"); | 3093 | "kernel, try again later\n"); |
3094 | return; | 3094 | return; |
3095 | } | 3095 | } |
3096 | spin_unlock(&t->sighand->siglock); | 3096 | spin_unlock(&t->sighand->siglock); |
3097 | new_t = kdb_prev_t != t; | 3097 | new_t = kdb_prev_t != t; |
3098 | kdb_prev_t = t; | 3098 | kdb_prev_t = t; |
3099 | if (t->state != TASK_RUNNING && new_t) { | 3099 | if (t->state != TASK_RUNNING && new_t) { |
3100 | kdb_printf("Process is not RUNNING, sending a signal from " | 3100 | kdb_printf("Process is not RUNNING, sending a signal from " |
3101 | "kdb risks deadlock\n" | 3101 | "kdb risks deadlock\n" |
3102 | "on the run queue locks. " | 3102 | "on the run queue locks. " |
3103 | "The signal has _not_ been sent.\n" | 3103 | "The signal has _not_ been sent.\n" |
3104 | "Reissue the kill command if you want to risk " | 3104 | "Reissue the kill command if you want to risk " |
3105 | "the deadlock.\n"); | 3105 | "the deadlock.\n"); |
3106 | return; | 3106 | return; |
3107 | } | 3107 | } |
3108 | sig = info->si_signo; | 3108 | sig = info->si_signo; |
3109 | if (send_sig_info(sig, info, t)) | 3109 | if (send_sig_info(sig, info, t)) |
3110 | kdb_printf("Fail to deliver Signal %d to process %d.\n", | 3110 | kdb_printf("Fail to deliver Signal %d to process %d.\n", |
3111 | sig, t->pid); | 3111 | sig, t->pid); |
3112 | else | 3112 | else |
3113 | kdb_printf("Signal %d is sent to process %d.\n", sig, t->pid); | 3113 | kdb_printf("Signal %d is sent to process %d.\n", sig, t->pid); |
3114 | } | 3114 | } |
3115 | #endif /* CONFIG_KGDB_KDB */ | 3115 | #endif /* CONFIG_KGDB_KDB */ |
3116 | 3116 |