linux-stable.git/kernel/signal.c, branch v3.16.6

signals: introduce kernel_sigaction()

2014-06-06T23:08:12+00:00

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

signals: disallow_signal() should flush the potentially pending signal

2014-06-06T23:08:12+00:00

disallow_signal() simply sets SIG_IGN, this is not enough and
recalc_sigpending() is simply pointless because in can never change the
state of TIF_SIGPENDING.

If we ignore a signal, we also need to do flush_sigqueue_mask() for the
case when this signal is pending, this way recalc_sigpending() can
actually clear TIF_SIGPENDING and we do not "leak" the allocated
siginfo's.

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

signals: kill the obsolete sigdelset() and recalc_sigpending() in allow_signal()

2014-06-06T23:08:11+00:00

allow_signal() does sigdelset(current->blocked) due to historic reason,
previously it could be called by a daemonize()'ed kthread, and
daemonize() played with current->blocked.

Now that daemonize() has gone away we can remove sigdelset() and
recalc_sigpending().  If a user really wants to unblock a signal, it
must use sigprocmask() or set_current_block() explicitely.

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

signals: mv {dis,}allow_signal() from sched.h/exit.c to signal.[ch]

2014-06-06T23:08:11+00:00

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

signals: cleanup the usage of t/current in do_sigaction()

2014-06-06T23:08:11+00:00

The usage of "task_struct *t" and "current" in do_sigaction() looks really
annoying and chaotic.  Initially "t" is used as a cached value of current
but not consistently, then it is reused as a loop variable and we have to
use "current" again.

Clean up this mess and also convert the code to use for_each_thread().

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

signals: rename rm_from_queue_full() to flush_sigqueue_mask()

2014-06-06T23:08:11+00:00

"rm_from_queue_full" looks ugly and misleading, especially now that
rm_from_queue() has gone away.  Rename it to flush_sigqueue_mask(), this
matches flush_sigqueue() we already have.

Also remove the obsolete comment which explains the difference with
rm_from_queue() we already killed.

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

signals: kill rm_from_queue(), change prepare_signal() to use for_each_thread()

2014-06-06T23:08:11+00:00

rm_from_queue() doesn't make sense.  The only caller, prepare_signal(),
can use rm_from_queue_full() with the same effect.

While at it, change prepare_signal() to use for_each_thread() instead of
do/while_each_thread.

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

signals: s/siginitset/sigemptyset/ in do_sigtimedwait()

2014-06-06T23:08:11+00:00

Cosmetic, but siginitset(0) looks a bit strange, sigemptyset() is what
do_sigtimedwait() needs.

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

ptrace: task_clear_jobctl_trapping()->wake_up_bit() needs mb()

2014-06-06T23:08:11+00:00

__wake_up_bit() checks waitqueue_active() and thus the caller needs mb()
as wake_up_bit() documents, fix task_clear_jobctl_trapping().

Signed-off-by: Oleg Nesterov 
Cc: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

sys_sgetmask/sys_ssetmask: add CONFIG_SGETMASK_SYSCALL

2014-06-04T23:54:14+00:00

sys_sgetmask and sys_ssetmask are obsolete system calls no longer
supported in libc.

This patch replaces architecture related __ARCH_WANT_SYS_SGETMAX by expert
mode configuration.That option is enabled by default for those
architectures.

Signed-off-by: Fabian Frederick 
Cc: Steven Miao 
Cc: Mikael Starvik 
Cc: Jesper Nilsson 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: Koichi Yasutake 
Cc: "James E.J. Bottomley" 
Cc: Helge Deller 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Greg Ungerer 
Cc: Heiko Carstens 
Cc: Oleg Nesterov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds