linux-toradex.git/include/uapi/linux/signal.h, branch v4.10-rc5

signals/sigaltstack: Change SS_AUTODISARM to (1U << 31)

2016-05-04T06:34:14+00:00

Using bit 4 divides the space of available bits strangely.  Use bit
31 instead so that we have a better chance of keeping flag and mode
bits separate in the long run.

Signed-off-by: Andy Lutomirski 
Cc: Al Viro 
Cc: Aleksa Sarai 
Cc: Amanieu d'Antras 
Cc: Andrea Arcangeli 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: Eric W. Biederman 
Cc: Frederic Weisbecker 
Cc: H. Peter Anvin 
Cc: Heinrich Schuchardt 
Cc: Jason Low 
Cc: Josh Triplett 
Cc: Konstantin Khlebnikov 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Palmer Dabbelt 
Cc: Paul Moore 
Cc: Pavel Emelyanov 
Cc: Peter Zijlstra 
Cc: Richard Weinberger 
Cc: Sasha Levin 
Cc: Shuah Khan 
Cc: Stas Sergeev 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Vladimir Davydov 
Cc: linux-api@vger.kernel.org
Link: http://lkml.kernel.org/r/bb996508a600af14b406810c3d58fe0e0d0afe0d.1462296606.git.luto@kernel.org
Signed-off-by: Ingo Molnar

signals/sigaltstack: Implement SS_AUTODISARM flag

2016-05-03T06:37:59+00:00

This patch implements the SS_AUTODISARM flag that can be OR-ed with
SS_ONSTACK when forming ss_flags.

When this flag is set, sigaltstack will be disabled when entering
the signal handler; more precisely, after saving sas to uc_stack.
When leaving the signal handler, the sigaltstack is restored by
uc_stack.

When this flag is used, it is safe to switch from sighandler with
swapcontext(). Without this flag, the subsequent signal will corrupt
the state of the switched-away sighandler.

To detect the support of this functionality, one can do:

  err = sigaltstack(SS_DISABLE | SS_AUTODISARM);
  if (err && errno == EINVAL)
	unsupported();

Signed-off-by: Stas Sergeev 
Cc: Al Viro 
Cc: Aleksa Sarai 
Cc: Amanieu d'Antras 
Cc: Andrea Arcangeli 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: Eric W. Biederman 
Cc: Frederic Weisbecker 
Cc: H. Peter Anvin 
Cc: Heinrich Schuchardt 
Cc: Jason Low 
Cc: Josh Triplett 
Cc: Konstantin Khlebnikov 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Palmer Dabbelt 
Cc: Paul Moore 
Cc: Pavel Emelyanov 
Cc: Peter Zijlstra 
Cc: Richard Weinberger 
Cc: Sasha Levin 
Cc: Shuah Khan 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Vladimir Davydov 
Cc: linux-api@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1460665206-13646-4-git-send-email-stsp@list.ru
Signed-off-by: Ingo Molnar

signals/sigaltstack: Prepare to add new SS_xxx flags

2016-05-03T06:37:59+00:00

This patch adds SS_FLAG_BITS - the mask that splits sigaltstack
mode values and bit-flags. Since there is no bit-flags yet, the
mask is defined to 0. The flags are added by subsequent patches.
With every new flag, the mask should have the appropriate bit cleared.

This makes sure if some flag is tried on a kernel that doesn't
support it, the -EINVAL error will be returned, because such a
flag will be treated as an invalid mode rather than the bit-flag.

That way the existence of the particular features can be probed
at run-time.

This change was suggested by Andy Lutomirski:

  https://lkml.org/lkml/2016/3/6/158

Signed-off-by: Stas Sergeev 
Cc: Al Viro 
Cc: Amanieu d'Antras 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Michal Hocko 
Cc: Oleg Nesterov 
Cc: Pavel Emelyanov 
Cc: Peter Zijlstra (Intel) 
Cc: Peter Zijlstra 
Cc: Richard Weinberger 
Cc: Sasha Levin 
Cc: Shuah Khan 
Cc: Thomas Gleixner 
Cc: Vladimir Davydov 
Cc: linux-api@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1460665206-13646-3-git-send-email-stsp@list.ru
Signed-off-by: Ingo Molnar

unify SS_ONSTACK/SS_DISABLE definitions

2012-12-19T23:07:39+00:00

Signed-off-by: Al Viro

UAPI: (Scripted) Disintegrate include/linux

2012-10-13T09:46:48+00:00

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