android_kernel_samsung_msm8226/arch
Al Viro 494486a1d2 alpha: deal with multiple simultaneously pending signals
Unlike the other targets, alpha sets _one_ sigframe and
buggers off until the next syscall/interrupt, even if
more signals are pending.  It leads to quite a few unpleasant
inconsistencies, starting with SIGSEGV potentially arriving
not where it should and including e.g. mess with sigsuspend();
consider two pending signals blocked until sigsuspend()
unblocks them.  We pick the first one; then, if we are hit
by interrupt while in the handler, we process the second one
as well.  If we are not, and if no syscalls had been made,
we get out of the first handler and leave the second signal
pending; normally sigreturn() would've picked it anyway, but
here it starts with restoring the original mask and voila -
the second signal is blocked again.  On everything else we
get both delivered consistently.

It's actually easy to fix; the only thing to watch out for
is prevention of double syscall restart.  Fortunately, the
idea I've nicked from arm fix by rmk works just fine...

Testcase demonstrating the behaviour in question; on alpha
we get one or both flags set (usually one), on everything
else both are always set.
	#include <signal.h>
	#include <stdio.h>
	int had1, had2;
	void f1(int sig) { had1 = 1; }
	void f2(int sig) { had2 = 1; }
	main()
	{
		sigset_t set1, set2;
		sigemptyset(&set1);
		sigemptyset(&set2);
		sigaddset(&set2, 1);
		sigaddset(&set2, 2);
		signal(1, f1);
		signal(2, f2);
		sigprocmask(SIG_SETMASK, &set2, NULL);
		raise(1);
		raise(2);
		sigsuspend(&set1);
		printf("had1:%d had2:%d\n", had1, had2);
	}

Tested-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Matt Turner <mattst88@gmail.com>
2010-09-18 23:08:29 -04:00
..
alpha alpha: deal with multiple simultaneously pending signals 2010-09-18 23:08:29 -04:00
arm arm: fix really nasty sigreturn bug 2010-09-17 10:22:18 -07:00
avr32 Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
blackfin Blackfin: bf52x/bf54x boards: drop unused nand page size 2010-08-27 16:08:43 -04:00
cris Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
frv Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
h8300 h8300: Fix missing consts in kernel_execve() 2010-09-07 13:52:28 -07:00
ia64 Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6 2010-09-16 12:58:44 -07:00
m32r Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
m68k m68k,m68knommu: Wire up fanotify_init, fanotify_mark, and prlimit64 2010-09-13 20:28:45 +02:00
m68knommu m68k,m68knommu: Wire up fanotify_init, fanotify_mark, and prlimit64 2010-09-13 20:28:45 +02:00
microblaze Merge branch 'merge-devicetree' of git://git.secretlab.ca/git/linux-2.6 2010-08-18 09:26:17 -07:00
mips compat: Make compat_alloc_user_space() incorporate the access_ok() 2010-09-14 16:08:45 -07:00
mn10300 MN10300: Fix up the IRQ names for the on-chip serial ports 2010-09-14 17:06:28 -07:00
parisc compat: Make compat_alloc_user_space() incorporate the access_ok() 2010-09-14 16:08:45 -07:00
powerpc compat: Make compat_alloc_user_space() incorporate the access_ok() 2010-09-14 16:08:45 -07:00
s390 compat: Make compat_alloc_user_space() incorporate the access_ok() 2010-09-14 16:08:45 -07:00
score Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
sh Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
sparc compat: Make compat_alloc_user_space() incorporate the access_ok() 2010-09-14 16:08:45 -07:00
tile Merge branch 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2010-09-16 12:54:54 -07:00
um Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2010-08-28 13:55:31 -07:00
x86 Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-09-16 19:38:08 -07:00
xtensa Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
.gitignore
Kconfig Merge branch 'perf/nmi' into perf/core 2010-08-05 08:45:05 +02:00