Eric Lee / smarc-ti-linux-kernel

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Commit 9fcb663be42e4727c1beabc7c80e2d839199e6b1

Authored by Anton Ivanov
Committed by Richard Weinberger
1 parent 0d71832e30

um: Missing pipe handling 

UML does not handle sigpipe. As a result when running it under
expect or redirecting the IO from the console to an external program
it will crash if the program stops or exits.

Signed-off-by: Anton Ivanov <antivano@cisco.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

Showing 1 changed file with 1 additions and 0 deletions Inline Diff

arch/um/os-Linux/main.c
Diff comments   View file @ 9fcb663
1 /* 1 /*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL 3 * Licensed under the GPL
4 */ 4 */
5 5
6 #include <stdio.h> 6 #include <stdio.h>
7 #include <stdlib.h> 7 #include <stdlib.h>
8 #include <unistd.h> 8 #include <unistd.h>
9 #include <errno.h> 9 #include <errno.h>
10 #include <signal.h> 10 #include <signal.h>
11 #include <string.h> 11 #include <string.h>
12 #include <sys/resource.h> 12 #include <sys/resource.h>
13 #include <as-layout.h> 13 #include <as-layout.h>
14 #include <init.h> 14 #include <init.h>
15 #include <kern_util.h> 15 #include <kern_util.h>
16 #include <os.h> 16 #include <os.h>
17 #include <um_malloc.h> 17 #include <um_malloc.h>
18 18
19 #define PGD_BOUND (4 * 1024 * 1024) 19 #define PGD_BOUND (4 * 1024 * 1024)
20 #define STACKSIZE (8 * 1024 * 1024) 20 #define STACKSIZE (8 * 1024 * 1024)
21 #define THREAD_NAME_LEN (256) 21 #define THREAD_NAME_LEN (256)
22 22
23 long elf_aux_hwcap; 23 long elf_aux_hwcap;
24 24
25 static void set_stklim(void) 25 static void set_stklim(void)
26 { 26 {
27 struct rlimit lim; 27 struct rlimit lim;
28 28
29 if (getrlimit(RLIMIT_STACK, &lim) < 0) { 29 if (getrlimit(RLIMIT_STACK, &lim) < 0) {
30 perror("getrlimit"); 30 perror("getrlimit");
31 exit(1); 31 exit(1);
32 } 32 }
33 if ((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)) { 33 if ((lim.rlim_cur == RLIM_INFINITY) || (lim.rlim_cur > STACKSIZE)) {
34 lim.rlim_cur = STACKSIZE; 34 lim.rlim_cur = STACKSIZE;
35 if (setrlimit(RLIMIT_STACK, &lim) < 0) { 35 if (setrlimit(RLIMIT_STACK, &lim) < 0) {
36 perror("setrlimit"); 36 perror("setrlimit");
37 exit(1); 37 exit(1);
38 } 38 }
39 } 39 }
40 } 40 }
41 41
42 static __init void do_uml_initcalls(void) 42 static __init void do_uml_initcalls(void)
43 { 43 {
44 initcall_t *call; 44 initcall_t *call;
45 45
46 call = &__uml_initcall_start; 46 call = &__uml_initcall_start;
47 while (call < &__uml_initcall_end) { 47 while (call < &__uml_initcall_end) {
48 (*call)(); 48 (*call)();
49 call++; 49 call++;
50 } 50 }
51 } 51 }
52 52
53 static void last_ditch_exit(int sig) 53 static void last_ditch_exit(int sig)
54 { 54 {
55 uml_cleanup(); 55 uml_cleanup();
56 exit(1); 56 exit(1);
57 } 57 }
58 58
59 static void install_fatal_handler(int sig) 59 static void install_fatal_handler(int sig)
60 { 60 {
61 struct sigaction action; 61 struct sigaction action;
62 62
63 /* All signals are enabled in this handler ... */ 63 /* All signals are enabled in this handler ... */
64 sigemptyset(&action.sa_mask); 64 sigemptyset(&action.sa_mask);
65 65
66 /* 66 /*
67 * ... including the signal being handled, plus we want the 67 * ... including the signal being handled, plus we want the
68 * handler reset to the default behavior, so that if an exit 68 * handler reset to the default behavior, so that if an exit
69 * handler is hanging for some reason, the UML will just die 69 * handler is hanging for some reason, the UML will just die
70 * after this signal is sent a second time. 70 * after this signal is sent a second time.
71 */ 71 */
72 action.sa_flags = SA_RESETHAND | SA_NODEFER; 72 action.sa_flags = SA_RESETHAND | SA_NODEFER;
73 action.sa_restorer = NULL; 73 action.sa_restorer = NULL;
74 action.sa_handler = last_ditch_exit; 74 action.sa_handler = last_ditch_exit;
75 if (sigaction(sig, &action, NULL) < 0) { 75 if (sigaction(sig, &action, NULL) < 0) {
76 printf("failed to install handler for signal %d - errno = %d\n", 76 printf("failed to install handler for signal %d - errno = %d\n",
77 sig, errno); 77 sig, errno);
78 exit(1); 78 exit(1);
79 } 79 }
80 } 80 }
81 81
82 #define UML_LIB_PATH ":" OS_LIB_PATH "/uml" 82 #define UML_LIB_PATH ":" OS_LIB_PATH "/uml"
83 83
84 static void setup_env_path(void) 84 static void setup_env_path(void)
85 { 85 {
86 char *new_path = NULL; 86 char *new_path = NULL;
87 char *old_path = NULL; 87 char *old_path = NULL;
88 int path_len = 0; 88 int path_len = 0;
89 89
90 old_path = getenv("PATH"); 90 old_path = getenv("PATH");
91 /* 91 /*
92 * if no PATH variable is set or it has an empty value 92 * if no PATH variable is set or it has an empty value
93 * just use the default + /usr/lib/uml 93 * just use the default + /usr/lib/uml
94 */ 94 */
95 if (!old_path || (path_len = strlen(old_path)) == 0) { 95 if (!old_path || (path_len = strlen(old_path)) == 0) {
96 if (putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH)) 96 if (putenv("PATH=:/bin:/usr/bin/" UML_LIB_PATH))
97 perror("couldn't putenv"); 97 perror("couldn't putenv");
98 return; 98 return;
99 } 99 }
100 100
101 /* append /usr/lib/uml to the existing path */ 101 /* append /usr/lib/uml to the existing path */
102 path_len += strlen("PATH=" UML_LIB_PATH) + 1; 102 path_len += strlen("PATH=" UML_LIB_PATH) + 1;
103 new_path = malloc(path_len); 103 new_path = malloc(path_len);
104 if (!new_path) { 104 if (!new_path) {
105 perror("couldn't malloc to set a new PATH"); 105 perror("couldn't malloc to set a new PATH");
106 return; 106 return;
107 } 107 }
108 snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path); 108 snprintf(new_path, path_len, "PATH=%s" UML_LIB_PATH, old_path);
109 if (putenv(new_path)) { 109 if (putenv(new_path)) {
110 perror("couldn't putenv to set a new PATH"); 110 perror("couldn't putenv to set a new PATH");
111 free(new_path); 111 free(new_path);
112 } 112 }
113 } 113 }
114 114
115 extern void scan_elf_aux( char **envp); 115 extern void scan_elf_aux( char **envp);
116 116
117 int __init main(int argc, char **argv, char **envp) 117 int __init main(int argc, char **argv, char **envp)
118 { 118 {
119 char **new_argv; 119 char **new_argv;
120 int ret, i, err; 120 int ret, i, err;
121 121
122 set_stklim(); 122 set_stklim();
123 123
124 setup_env_path(); 124 setup_env_path();
125 125
126 setsid(); 126 setsid();
127 127
128 new_argv = malloc((argc + 1) * sizeof(char *)); 128 new_argv = malloc((argc + 1) * sizeof(char *));
129 if (new_argv == NULL) { 129 if (new_argv == NULL) {
130 perror("Mallocing argv"); 130 perror("Mallocing argv");
131 exit(1); 131 exit(1);
132 } 132 }
133 for (i = 0; i < argc; i++) { 133 for (i = 0; i < argc; i++) {
134 new_argv[i] = strdup(argv[i]); 134 new_argv[i] = strdup(argv[i]);
135 if (new_argv[i] == NULL) { 135 if (new_argv[i] == NULL) {
136 perror("Mallocing an arg"); 136 perror("Mallocing an arg");
137 exit(1); 137 exit(1);
138 } 138 }
139 } 139 }
140 new_argv[argc] = NULL; 140 new_argv[argc] = NULL;
141 141
142 /* 142 /*
143 * Allow these signals to bring down a UML if all other 143 * Allow these signals to bring down a UML if all other
144 * methods of control fail. 144 * methods of control fail.
145 */ 145 */
146 install_fatal_handler(SIGINT); 146 install_fatal_handler(SIGINT);
147 install_fatal_handler(SIGTERM); 147 install_fatal_handler(SIGTERM);
148 148
149 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA 149 #ifdef CONFIG_ARCH_REUSE_HOST_VSYSCALL_AREA
150 scan_elf_aux(envp); 150 scan_elf_aux(envp);
151 #endif 151 #endif
152 152
153 do_uml_initcalls(); 153 do_uml_initcalls();
154 change_sig(SIGPIPE, 0);
154 ret = linux_main(argc, argv); 155 ret = linux_main(argc, argv);
155 156
156 /* 157 /*
157 * Disable SIGPROF - I have no idea why libc doesn't do this or turn 158 * Disable SIGPROF - I have no idea why libc doesn't do this or turn
158 * off the profiling time, but UML dies with a SIGPROF just before 159 * off the profiling time, but UML dies with a SIGPROF just before
159 * exiting when profiling is active. 160 * exiting when profiling is active.
160 */ 161 */
161 change_sig(SIGPROF, 0); 162 change_sig(SIGPROF, 0);
162 163
163 /* 164 /*
164 * This signal stuff used to be in the reboot case. However, 165 * This signal stuff used to be in the reboot case. However,
165 * sometimes a SIGVTALRM can come in when we're halting (reproducably 166 * sometimes a SIGVTALRM can come in when we're halting (reproducably
166 * when writing out gcov information, presumably because that takes 167 * when writing out gcov information, presumably because that takes
167 * some time) and cause a segfault. 168 * some time) and cause a segfault.
168 */ 169 */
169 170
170 /* stop timers and set SIGVTALRM to be ignored */ 171 /* stop timers and set SIGVTALRM to be ignored */
171 disable_timer(); 172 disable_timer();
172 173
173 /* disable SIGIO for the fds and set SIGIO to be ignored */ 174 /* disable SIGIO for the fds and set SIGIO to be ignored */
174 err = deactivate_all_fds(); 175 err = deactivate_all_fds();
175 if (err) 176 if (err)
176 printf("deactivate_all_fds failed, errno = %d\n", -err); 177 printf("deactivate_all_fds failed, errno = %d\n", -err);
177 178
178 /* 179 /*
179 * Let any pending signals fire now. This ensures 180 * Let any pending signals fire now. This ensures
180 * that they won't be delivered after the exec, when 181 * that they won't be delivered after the exec, when
181 * they are definitely not expected. 182 * they are definitely not expected.
182 */ 183 */
183 unblock_signals(); 184 unblock_signals();
184 185
185 /* Reboot */ 186 /* Reboot */
186 if (ret) { 187 if (ret) {
187 printf("\n"); 188 printf("\n");
188 execvp(new_argv[0], new_argv); 189 execvp(new_argv[0], new_argv);
189 perror("Failed to exec kernel"); 190 perror("Failed to exec kernel");
190 ret = 1; 191 ret = 1;
191 } 192 }
192 printf("\n"); 193 printf("\n");
193 return uml_exitcode; 194 return uml_exitcode;
194 } 195 }
195 196
196 extern void *__real_malloc(int); 197 extern void *__real_malloc(int);
197 198
198 void *__wrap_malloc(int size) 199 void *__wrap_malloc(int size)
199 { 200 {
200 void *ret; 201 void *ret;
201 202
202 if (!kmalloc_ok) 203 if (!kmalloc_ok)
203 return __real_malloc(size); 204 return __real_malloc(size);
204 else if (size <= UM_KERN_PAGE_SIZE) 205 else if (size <= UM_KERN_PAGE_SIZE)
205 /* finding contiguous pages can be hard*/ 206 /* finding contiguous pages can be hard*/
206 ret = uml_kmalloc(size, UM_GFP_KERNEL); 207 ret = uml_kmalloc(size, UM_GFP_KERNEL);
207 else ret = vmalloc(size); 208 else ret = vmalloc(size);
208 209
209 /* 210 /*
210 * glibc people insist that if malloc fails, errno should be 211 * glibc people insist that if malloc fails, errno should be
211 * set by malloc as well. So we do. 212 * set by malloc as well. So we do.
212 */ 213 */
213 if (ret == NULL) 214 if (ret == NULL)
214 errno = ENOMEM; 215 errno = ENOMEM;
215 216
216 return ret; 217 return ret;
217 } 218 }
218 219
219 void *__wrap_calloc(int n, int size) 220 void *__wrap_calloc(int n, int size)
220 { 221 {
221 void *ptr = __wrap_malloc(n * size); 222 void *ptr = __wrap_malloc(n * size);
222 223
223 if (ptr == NULL) 224 if (ptr == NULL)
224 return NULL; 225 return NULL;
225 memset(ptr, 0, n * size); 226 memset(ptr, 0, n * size);
226 return ptr; 227 return ptr;
227 } 228 }
228 229
229 extern void __real_free(void *); 230 extern void __real_free(void *);
230 231
231 extern unsigned long high_physmem; 232 extern unsigned long high_physmem;
232 233
233 void __wrap_free(void *ptr) 234 void __wrap_free(void *ptr)
234 { 235 {
235 unsigned long addr = (unsigned long) ptr; 236 unsigned long addr = (unsigned long) ptr;
236 237
237 /* 238 /*
238 * We need to know how the allocation happened, so it can be correctly 239 * We need to know how the allocation happened, so it can be correctly
239 * freed. This is done by seeing what region of memory the pointer is 240 * freed. This is done by seeing what region of memory the pointer is
240 * in - 241 * in -
241 * physical memory - kmalloc/kfree 242 * physical memory - kmalloc/kfree
242 * kernel virtual memory - vmalloc/vfree 243 * kernel virtual memory - vmalloc/vfree
243 * anywhere else - malloc/free 244 * anywhere else - malloc/free
244 * If kmalloc is not yet possible, then either high_physmem and/or 245 * If kmalloc is not yet possible, then either high_physmem and/or
245 * end_vm are still 0 (as at startup), in which case we call free, or 246 * end_vm are still 0 (as at startup), in which case we call free, or
246 * we have set them, but anyway addr has not been allocated from those 247 * we have set them, but anyway addr has not been allocated from those
247 * areas. So, in both cases __real_free is called. 248 * areas. So, in both cases __real_free is called.
248 * 249 *
249 * CAN_KMALLOC is checked because it would be bad to free a buffer 250 * CAN_KMALLOC is checked because it would be bad to free a buffer
250 * with kmalloc/vmalloc after they have been turned off during 251 * with kmalloc/vmalloc after they have been turned off during
251 * shutdown. 252 * shutdown.
252 * XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so 253 * XXX: However, we sometimes shutdown CAN_KMALLOC temporarily, so
253 * there is a possibility for memory leaks. 254 * there is a possibility for memory leaks.
254 */ 255 */
255 256
256 if ((addr >= uml_physmem) && (addr < high_physmem)) { 257 if ((addr >= uml_physmem) && (addr < high_physmem)) {
257 if (kmalloc_ok) 258 if (kmalloc_ok)
258 kfree(ptr); 259 kfree(ptr);
259 } 260 }
260 else if ((addr >= start_vm) && (addr < end_vm)) { 261 else if ((addr >= start_vm) && (addr < end_vm)) {
261 if (kmalloc_ok) 262 if (kmalloc_ok)
262 vfree(ptr); 263 vfree(ptr);
263 } 264 }
264 else __real_free(ptr); 265 else __real_free(ptr);
265 } 266 }
266 267