21 Nov, 2015
1 commit
-
sigsuspend() is nowhere used except in signal.c itself, so we can mark it
static do not pollute the global namespace.But this patch is more than a boring cleanup patch, it fixes a real issue
on UserModeLinux. UML has a special console driver to display ttys using
xterm, or other terminal emulators, on the host side. Vegard reported
that sometimes UML is unable to spawn a xterm and he's facing the
following warning:WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0()
It turned out that this warning makes absolutely no sense as the UML
xterm code calls sigsuspend() on the host side, at least it tries. But
as the kernel itself offers a sigsuspend() symbol the linker choose this
one instead of the glibc wrapper. Interestingly this code used to work
since ever but always blocked signals on the wrong side. Some recent
kernel change made the WARN_ON() trigger and uncovered the bug.It is a wonderful example of how much works by chance on computers. :-)
Fixes: 68f3f16d9ad0f1 ("new helper: sigsuspend()")
Signed-off-by: Richard Weinberger
Reported-by: Vegard Nossum
Tested-by: Vegard Nossum
Acked-by: Oleg Nesterov
Cc: [3.5+]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Oct, 2014
1 commit
-
Kill _NSIG_WORDS_is_unsupported_size(), use BUILD_BUG() instead. This
simplifies the code, avoids the nested-externs warnings, and this way we
do not defer the problem to linker.Also, fix the indentation in _SIG_SET_BINOP() and _SIG_SET_OP().
Note: this patch assumes that the code like "if (0) BUILD_BUG();" is
valid. If not (say __compiletime_error() is not defined and thus
__compiletime_error_fallback() uses a negative array) we should fix
BUILD_BUG() and/or BUILD_BUG_ON_MSG(). This code should be fine by
definition, this is the documented purpose of BUILD_BUG().[sfr@canb.auug.org.au: fix powerpc build failures]
Signed-off-by: Oleg Nesterov
Reported-by: Jeff Kirsher
Reviewed-by: Josh Triplett
Signed-off-by: Stephen Rothwell
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Aug, 2014
2 commits
-
Now we can turn get_signal() to the main function.
Signed-off-by: Richard Weinberger
-
- Pass a ksignal struct to it
- Remove unused regs parameter
- Make it private as it's nowhere outside of kernel/signal.c is usedSigned-off-by: Richard Weinberger
07 Jun, 2014
3 commits
-
Now that allow_signal() is really trivial we can unify it with
disallow_signal(). Add the new helper, kernel_sigaction(), and
reimplement allow_signal/disallow_signal as a trivial wrappers.This saves one EXPORT_SYMBOL() and the new helper can have more users.
Signed-off-by: Oleg Nesterov
Cc: Peter Zijlstra
Cc: Al Viro
Cc: David Woodhouse
Cc: Frederic Weisbecker
Cc: Geert Uytterhoeven
Cc: Ingo Molnar
Cc: Mathieu Desnoyers
Cc: Richard Weinberger
Cc: Steven Rostedt
Cc: Tejun Heo
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Move the declaration/definition of allow_signal/disallow_signal to
signal.h/signal.c. The new place is more logical and allows to use the
static helpers in signal.c (see the next changes).While at it, make them return void and remove the valid_signal() check.
Nobody checks the returned value, and in-kernel users must not pass the
wrong signal number.Signed-off-by: Oleg Nesterov
Cc: Peter Zijlstra
Cc: Al Viro
Cc: David Woodhouse
Cc: Frederic Weisbecker
Cc: Geert Uytterhoeven
Cc: Ingo Molnar
Cc: Mathieu Desnoyers
Cc: Richard Weinberger
Cc: Steven Rostedt
Cc: Tejun Heo
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It has no users and it doesn't look useful. I do not know why/when it was
introduced, I can't even find any user in the git history.Signed-off-by: Oleg Nesterov
Acked-by: Geert Uytterhoeven
Cc: Peter Zijlstra
Cc: Al Viro
Cc: David Woodhouse
Cc: Frederic Weisbecker
Cc: Ingo Molnar
Cc: Mathieu Desnoyers
Cc: Richard Weinberger
Cc: Steven Rostedt
Cc: Tejun Heo
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Sep, 2013
1 commit
-
For performance reasons, when SMAP is in use, SMAP is left open for an
entire put_user_try { ... } put_user_catch(); block, however, calling
__put_user() in the middle of that block will close SMAP as the
STAC..CLAC constructs intentionally do not nest.Furthermore, using __put_user() rather than put_user_ex() here is bad
for performance.Thus, introduce new [compat_]save_altstack_ex() helpers that replace
__[compat_]save_altstack() for x86, being currently the only
architecture which supports put_user_try { ... } put_user_catch().Reported-by: H. Peter Anvin
Signed-off-by: Al Viro
Signed-off-by: H. Peter Anvin
Cc: # v3.8+
Link: http://lkml.kernel.org/n/tip-es5p6y64if71k8p5u08agv9n@git.kernel.org
02 May, 2013
2 commits
-
Pull VFS updates from Al Viro,
Misc cleanups all over the place, mainly wrt /proc interfaces (switch
create_proc_entry to proc_create(), get rid of the deprecated
create_proc_read_entry() in favor of using proc_create_data() and
seq_file etc).7kloc removed.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits)
don't bother with deferred freeing of fdtables
proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h
proc: Make the PROC_I() and PDE() macros internal to procfs
proc: Supply a function to remove a proc entry by PDE
take cgroup_open() and cpuset_open() to fs/proc/base.c
ppc: Clean up scanlog
ppc: Clean up rtas_flash driver somewhat
hostap: proc: Use remove_proc_subtree()
drm: proc: Use remove_proc_subtree()
drm: proc: Use minor->index to label things, not PDE->name
drm: Constify drm_proc_list[]
zoran: Don't print proc_dir_entry data in debug
reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show()
proc: Supply an accessor for getting the data from a PDE's parent
airo: Use remove_proc_subtree()
rtl8192u: Don't need to save device proc dir PDE
rtl8187se: Use a dir under /proc/net/r8180/
proc: Add proc_mkdir_data()
proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h}
proc: Move PDE_NET() to fs/proc/proc_net.c
... -
Move some bits from linux/proc_fs.h to linux/of.h, signal.h and tty.h.
Also move proc_tty_init() and proc_device_tree_init() to fs/proc/internal.h as
they're internal to procfs.Signed-off-by: David Howells
Acked-by: Greg Kroah-Hartman
Acked-by: Grant Likely
cc: devicetree-discuss@lists.ozlabs.org
cc: linux-arch@vger.kernel.org
cc: Greg Kroah-Hartman
cc: Jri Slaby
Signed-off-by: Al Viro
20 Mar, 2013
1 commit
-
MIPS's siginfo handling has been broken since this commit:
commit 574c4866e33d648520a8bd5bf6f573ea6e554e88
Author: Al Viro
Date: Sun Nov 25 22:24:19 2012 -0500
consolidate kernel-side struct sigaction declarationsfor 64-bit BE MIPS CPUs.
The UAPI variant looks like this:
struct sigaction {
unsigned int sa_flags;
__sighandler_t sa_handler;
sigset_t sa_mask;
};but the core kernel's variant looks like this:
struct sigaction {
#ifndef __ARCH_HAS_ODD_SIGACTION
__sighandler_t sa_handler;
unsigned long sa_flags;
#else
unsigned long sa_flags;
__sighandler_t sa_handler;
#endif
#ifdef __ARCH_HAS_SA_RESTORER
__sigrestore_t sa_restorer;
#endif
sigset_t sa_mask;
};The problem is that sa_flags has been changed from an unsigned int to an
unsigned long.Fix this by making sa_flags unsigned int if __ARCH_HAS_ODD_SIGACTION is
defined.Whilst we're at it, rename __ARCH_HAS_ODD_SIGACTION to
__ARCH_HAS_IRIX_SIGACTION.Signed-off-by: David Howells
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Acked-by: Al Viro
Signed-off-by: Ralf Baechle
04 Feb, 2013
7 commits
-
usual "call force_sigsegv or signal_delivered" logics. Takes
ksignal instead of separate siginfo/k_sigaction.Signed-off-by: Al Viro
-
On success get_signal_to_deliver() fills k_sigaction and siginfo.
_All_ users pass it addresses of the local variables sitting in
the same function. Then they proceed to pass those addresses
pretty much in tandem to a bunch of helper functions; again, all
callers of those helpers are passing them such a pair, and one that
had been through get_signal_to_deliver() at that.The obvious cleanup: introduce a new type that would contain a
pair (struct ksignal) and begin switching to
using it. Turns out that it's convenient to store the signal number
in the same object.New helper, taking that sucker is a wrapper for get_signal_to_deliver();
takes struct ksignal * and returns bool. On success fills ksignal
with the information for signal handler to be invoked.For now it's a macro (to avoid header ordering headache), but eventually
it'll be a function in kernel/signal.c, with get_signal_to_deliver()
folded into it.Signed-off-by: Al Viro
-
conditional on OLD_SIGACTION/COMPAT_OLD_SIGACTION
Signed-off-by: Al Viro
-
Signed-off-by: Al Viro
-
Only alpha and sparc are unusual - they have ka_restorer in it.
And nobody needs that exposed to userland.Signed-off-by: Al Viro
-
C ABI violations on sparc, ppc and mips
Signed-off-by: Al Viro
-
conditional on GENERIC_COMPAT_RT_SIGPENDING; by the end of that series
it will become the same thing as COMPAT and conditional will die out.Signed-off-by: Al Viro
20 Dec, 2012
2 commits
-
note that they are relying on access_ok() already checked by caller.
Signed-off-by: Al Viro
-
to be used by rt_sigreturn instances
Signed-off-by: Al Viro
13 Oct, 2012
1 commit
-
Signed-off-by: David Howells
Acked-by: Arnd Bergmann
Acked-by: Thomas Gleixner
Acked-by: Michael Kerrisk
Acked-by: Paul E. McKenney
Acked-by: Dave Jones
02 Jun, 2012
2 commits
-
Does block_sigmask() + tracehook_signal_handler(); called when
sigframe has been successfully built. All architectures converted
to it; block_sigmask() itself is gone now (merged into this one).I'm still not too happy with the signature, but that's a separate
story (IMO we need a structure that would contain signal number +
siginfo + k_sigaction, so that get_signal_to_deliver() would fill one,
signal_delivered(), handle_signal() and probably setup...frame() -
take one).Signed-off-by: Al Viro
-
Only 3 out of 63 do not. Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.Signed-off-by: Al Viro
22 May, 2012
1 commit
-
guts of saved_sigmask-based sigsuspend/rt_sigsuspend. Takes
kernel sigset_t *.Open-coded instances replaced with calling it.
Signed-off-by: Al Viro
11 Jan, 2012
1 commit
-
Abstract the code sequence for adding a signal handler's sa_mask to
current->blocked because the sequence is identical for all architectures.
Furthermore, in the past some architectures actually got this code wrong,
so introduce a wrapper that all architectures can use.Signed-off-by: Matt Fleming
Signed-off-by: Oleg Nesterov
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: H. Peter Anvin
Cc: Tejun Heo
Cc: "David S. Miller"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 May, 2011
1 commit
-
* 'ptrace' of git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc: (41 commits)
signal: trivial, fix the "timespec declared inside parameter list" warning
job control: reorganize wait_task_stopped()
ptrace: fix signal->wait_chldexit usage in task_clear_group_stop_trapping()
signal: sys_sigprocmask() needs retarget_shared_pending()
signal: cleanup sys_sigprocmask()
signal: rename signandsets() to sigandnsets()
signal: do_sigtimedwait() needs retarget_shared_pending()
signal: introduce do_sigtimedwait() to factor out compat/native code
signal: sys_rt_sigtimedwait: simplify the timeout logic
signal: cleanup sys_rt_sigprocmask()
x86: signal: sys_rt_sigreturn() should use set_current_blocked()
x86: signal: handle_signal() should use set_current_blocked()
signal: sigprocmask() should do retarget_shared_pending()
signal: sigprocmask: narrow the scope of ->siglock
signal: retarget_shared_pending: optimize while_each_thread() loop
signal: retarget_shared_pending: consider shared/unblocked signals only
signal: introduce retarget_shared_pending()
ptrace: ptrace_check_attach() should not do s/STOPPED/TRACED/
signal: Turn SIGNAL_STOP_DEQUEUED into GROUP_STOP_DEQUEUED
signal: do_signal_stop: Remove the unneeded task_clear_group_stop_pending()
...
20 May, 2011
1 commit
-
This fixes these build errors on powerpc:
In file included from arch/powerpc/mm/fault.c:18:
include/linux/signal.h:239: error: 'struct task_struct' declared inside parameter list
include/linux/signal.h:239: error: its scope is only this definition or declaration, which is probably not what you want
include/linux/signal.h:240: error: 'struct task_struct' declared inside parameter list
..Exposed by commit e66eed651fd1 ("list: remove prefetching from regular
list iterators"), which removed the include of from
.Without that, linux/signal.h no longer accidentally got the declaration
of 'struct task_struct'.Fix by properly declaring the struct, rather than introducing any new
header file dependency.Signed-off-by: Stephen Rothwell
Signed-off-by: Linus Torvalds
18 May, 2011
1 commit
-
Fix the compile warning, do_sigtimedwait(struct timespec *) in signal.h
needs the forward declaration of timespec.Reported-and-acked-by: Mike Frysinger
Signed-off-by: Oleg Nesterov
28 Apr, 2011
3 commits
-
As Tejun and Linus pointed out, "nand" is the wrong name for "x & ~y",
it should be "andn". Rename signandsets() as suggested.Suggested-by: Tejun Heo
Signed-off-by: Oleg Nesterov
Acked-by: Tejun Heo -
Factor out the common code in sys_rt_sigtimedwait/compat_sys_rt_sigtimedwait
to the new helper, do_sigtimedwait().Add the comment to document the extra tick we add to timespec_to_jiffies(ts),
thanks to Linus who explained this to me.Perhaps it would be better to move compat_sys_rt_sigtimedwait() into
signal.c under CONFIG_COMPAT, then we can make do_sigtimedwait() static.Signed-off-by: Oleg Nesterov
Acked-by: Tejun Heo
Reviewed-by: Matt Fleming -
In short, almost every changing of current->blocked is wrong, or at least
can lead to the unexpected results.For example. Two threads T1 and T2, T1 sleeps in sigtimedwait/pause/etc.
kill(tgid, SIG) can pick T2 for TIF_SIGPENDING. If T2 calls sigprocmask()
and blocks SIG before it notices the pending signal, nobody else can handle
this pending shared signal.I am not sure this is bug, but at least this looks strange imho. T1 should
not sleep forever, there is a signal which should wake it up.This patch moves the code which actually changes ->blocked into the new
helper, set_current_blocked() and changes this code to call
retarget_shared_pending() as exit_signals() does. We should only care about
the signals we just blocked, we use "newset & ~current->blocked" as a mask.We do not check !sigisemptyset(newblocked), retarget_shared_pending() is
cheap unless mask & shared_pending.Note: for this particular case we could simply change sigprocmask() to
return -EINTR if signal_pending(), but then we should change other callers
and, more importantly, if we need this fix then set_current_blocked() will
have more callers and some of them can't restart. See the next patch as a
random example.Signed-off-by: Oleg Nesterov
Reviewed-by: Matt Fleming
Acked-by: Tejun Heo
13 Mar, 2010
1 commit
-
Extern declarations in sysctl.c should be moved to their own header file,
and then include them in relavant .c files.Move print_fatal_signals extern declaration to linux/signal.h
Signed-off-by: Dave Young
Cc: Oleg Nesterov
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Sep, 2009
1 commit
-
Introduce do_send_sig_info() and convert group_send_sig_info(),
send_sig_info(), do_send_specific() to use this helper.Hopefully it will have more users soon, it allows to specify
specific/group behaviour via "bool group" argument.Shaves 80 bytes from .text.
Signed-off-by: Oleg Nesterov
Cc: Peter Zijlstra
Cc: stephane eranian
Cc: Ingo Molnar
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 May, 2009
1 commit
-
sys_kill has the per thread counterpart sys_tgkill. sigqueueinfo is
missing a thread directed counterpart. Such an interface is important
for migrating applications from other OSes which have the per thread
delivery implemented.Signed-off-by: Thomas Gleixner
Reviewed-by: Oleg Nesterov
Acked-by: Roland McGrath
Acked-by: Ulrich Drepper
30 Apr, 2008
1 commit
-
Previously handle_stop_signal(SIGCONT) could drop ->siglock. That is why
kill_pid_info(SIGCONT) takes tasklist_lock to make sure the target task can't
go away after unlock. Not needed now.Signed-off-by: Oleg Nesterov
Cc: Roland McGrath
Cc: Jiri Kosina
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Feb, 2008
1 commit
-
do_signal_stop() counts all sub-thread and sets ->group_stop_count
accordingly. Every thread should decrement ->group_stop_count and stop,
the last one should notify the parent.However a sub-thread can exit before it notices the signal_pending(), or it
may be somewhere in do_exit() already. In that case the group stop never
finishes properly.Note: this is a minimal fix, we can add some optimizations later. Say we
can return quickly if thread_group_empty(). Also, we can move some signal
related code from exit_notify() to exit_signals().Signed-off-by: Oleg Nesterov
Acked-by: Davide Libenzi
Cc: Ingo Molnar
Cc: Roland McGrath
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Feb, 2008
1 commit
-
Add a proper prototype for signals_init() in include/linux/signal.h
Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Jul, 2007
1 commit
-
This patch makes the i386 behave the same way that x86_64 does when a
segfault happens. A line gets printed to the kernel log so that tools
that need to check for failures can behave more uniformly between
debug.show_unhandled_signals sysctl variable to 0 (or by doing echo 0 >
/proc/sys/debug/exception-trace)Also, all of the lines being printed are now using printk_ratelimit() to
deny the ability of DoS from a local user with a program like the
following:main()
{
while (1)
if (!fork()) *(int *)0 = 0;
}This new revision also includes the fix that Andrew did which got rid of
new sysctl that was added to the system in earlier versions of this.
Also, 'show-unhandled-signals' sysctl has been renamed back to the old
'exception-trace' to avoid breakage of people's scripts.AK: Enabling by default for i386 will be likely controversal, but let's see what happens
AK: Really folks, before complaining just fix your segfaults
AK: I bet this will find a lot of silent issuesSigned-off-by: Masoud Sharbiani
Signed-off-by: Andi Kleen
[ Personally, I've found the complaints useful on x86-64, so I'm all for
this. That said, I wonder if we could do it more prettily.. -Linus ]
Signed-off-by: Linus Torvalds
17 Jul, 2007
1 commit
-
Remove the obviously unnecessary includes of under the
include/linux/ directory, and fix the couple errors that are introduced as
a result of that.Signed-off-by: Robert P. J. Day
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 May, 2007
1 commit
-
This patch series implements the new signalfd() system call.
I took part of the original Linus code (and you know how badly it can be
broken :), and I added even more breakage ;) Signals are fetched from the same
signal queue used by the process, so signalfd will compete with standard
kernel delivery in dequeue_signal(). If you want to reliably fetch signals on
the signalfd file, you need to block them with sigprocmask(SIG_BLOCK). This
seems to be working fine on my Dual Opteron machine. I made a quick test
program for it:http://www.xmailserver.org/signafd-test.c
The signalfd() system call implements signal delivery into a file descriptor
receiver. The signalfd file descriptor if created with the following API:int signalfd(int ufd, const sigset_t *mask, size_t masksize);
The "ufd" parameter allows to change an existing signalfd sigmask, w/out going
to close/create cycle (Linus idea). Use "ufd" == -1 if you want a brand new
signalfd file.The "mask" allows to specify the signal mask of signals that we are interested
in. The "masksize" parameter is the size of "mask".The signalfd fd supports the poll(2) and read(2) system calls. The poll(2)
will return POLLIN when signals are available to be dequeued. As a direct
consequence of supporting the Linux poll subsystem, the signalfd fd can use
used together with epoll(2) too.The read(2) system call will return a "struct signalfd_siginfo" structure in
the userspace supplied buffer. The return value is the number of bytes copied
in the supplied buffer, or -1 in case of error. The read(2) call can also
return 0, in case the sighand structure to which the signalfd was attached,
has been orphaned. The O_NONBLOCK flag is also supported, and read(2) will
return -EAGAIN in case no signal is available.If the size of the buffer passed to read(2) is lower than sizeof(struct
signalfd_siginfo), -EINVAL is returned. A read from the signalfd can also
return -ERESTARTSYS in case a signal hits the process. The format of the
struct signalfd_siginfo is, and the valid fields depends of the (->code &
__SI_MASK) value, in the same way a struct siginfo would:struct signalfd_siginfo {
__u32 signo; /* si_signo */
__s32 err; /* si_errno */
__s32 code; /* si_code */
__u32 pid; /* si_pid */
__u32 uid; /* si_uid */
__s32 fd; /* si_fd */
__u32 tid; /* si_fd */
__u32 band; /* si_band */
__u32 overrun; /* si_overrun */
__u32 trapno; /* si_trapno */
__s32 status; /* si_status */
__s32 svint; /* si_int */
__u64 svptr; /* si_ptr */
__u64 utime; /* si_utime */
__u64 stime; /* si_stime */
__u64 addr; /* si_addr */
};[akpm@linux-foundation.org: fix signalfd_copyinfo() on i386]
Signed-off-by: Davide Libenzi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
