linux/kernel
Linus Torvalds a27341cd5f Prioritize synchronous signals over 'normal' signals
This makes sure that we pick the synchronous signals caused by a
processor fault over any pending regular asynchronous signals sent to
use by [t]kill().

This is not strictly required semantics, but it makes it _much_ easier
for programs like Wine that expect to find the fault information in the
signal stack.

Without this, if a non-synchronous signal gets picked first, the delayed
asynchronous signal will have its signal context pointing to the new
signal invocation, rather than the instruction that caused the SIGSEGV
or SIGBUS in the first place.

This is not all that pretty, and we're discussing making the synchronous
signals more explicit rather than have these kinds of implicit
preferences of SIGSEGV and friends.  See for example

	http://bugzilla.kernel.org/show_bug.cgi?id=15395

for some of the discussion.  But in the meantime this is a simple and
fairly straightforward work-around, and the whole

	if (x & Y)
		x &= Y;

thing can be compiled into (and gcc does do it) just three instructions:

	movq    %rdx, %rax
	andl    $Y, %eax
	cmovne  %rax, %rdx

so it is at least a simple solution to a subtle issue.

Reported-and-tested-by: Pavel Vilim <wylda@volny.cz>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-03-03 19:21:10 -08:00
..
gcov microblaze: Enable GCOV_PROFILE_ALL 2009-09-21 14:29:21 +02:00
irq sparseirq: Use radix_tree instead of ptrs array 2010-02-17 17:27:20 -08:00
power PM / Hibernate: Fix preallocating of memory 2010-02-26 20:39:13 +01:00
time Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-01 08:48:25 -08:00
trace Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2010-03-03 07:34:18 -08:00
.gitignore
acct.c bsdacct: fix uid/gid misreporting 2009-12-15 08:53:10 -08:00
async.c
audit.c Audit: send signal info if selinux is disabled 2009-09-24 03:50:26 -04:00
audit.h
audit_tree.c fix more leaks in audit_tree.c tag_chunk() 2009-12-19 09:27:43 -08:00
audit_watch.c Audit: reorganize struct audit_watch to save 8 bytes 2009-09-24 03:50:25 -04:00
auditfilter.c
auditsc.c Sanitize f_flags helpers 2009-12-22 12:27:34 -05:00
backtracetest.c
bounds.c kbuild: move bounds.h to include/generated 2009-12-12 13:08:14 +01:00
capability.c capabilities: Use RCU to protect task lookup in sys_capget 2009-12-10 09:42:48 +11:00
cgroup.c sched, cgroups: Fix module export 2010-02-25 12:02:13 +01:00
cgroup_freezer.c cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time 2009-09-24 07:20:58 -07:00
compat.c
configs.c
cpu.c sched: Correct printk whitespace in warning from cpu down task check 2010-01-28 06:59:55 +01:00
cpuset.c sched: Fix balance vs hotplug race 2009-12-06 21:10:56 +01:00
cred-internals.h
cred.c kernel/cred.c: use kmem_cache_free 2010-02-03 10:21:57 +11:00
delayacct.c headers: taskstats_kern.h trim 2009-09-18 09:48:52 -07:00
dma.c
early_res.c early_res: Need to save the allocation name in drop_range_partial() 2010-03-01 23:23:02 -08:00
exec_domain.c
exit.c sched: Use lockdep-based checking on rcu_dereference() 2010-02-25 10:34:26 +01:00
extable.c
fork.c sched: Use lockdep-based checking on rcu_dereference() 2010-02-25 10:34:26 +01:00
freezer.c sched: fix nr_uninterruptible accounting of frozen tasks really 2009-07-18 14:19:53 +02:00
futex.c futex: Handle futex value corruption gracefully 2010-02-03 15:13:22 +01:00
futex_compat.c futex: Protect pid lookup in compat code with RCU 2009-12-09 14:22:14 +01:00
groups.c
hrtimer.c hrtimers: Convert to raw_spinlocks 2009-12-14 23:55:34 +01:00
hung_task.c softlockup: Fix hung_task_check_count sysctl 2009-11-27 06:21:57 +01:00
hw_breakpoint.c perf: Make bp_len type to u64 generic across the arch 2010-02-04 01:07:12 +01:00
itimer.c itimers: Fix racy writes to cpu_itimer fields 2009-11-18 16:32:12 +01:00
kallsyms.c hw-breakpoints: Fix broken hw-breakpoint sample module 2009-11-10 11:23:29 +01:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks mutex: Better control mutex adaptive spinning config 2009-12-03 11:50:11 +01:00
Kconfig.preempt
kexec.c percpu: add __percpu sparse annotations to core kernel subsystems 2010-02-17 11:17:38 +09:00
kfifo.c kfifo: Don't use integer as NULL pointer 2010-02-16 15:11:08 -08:00
kgdb.c Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-02-04 16:07:41 -08:00
kmod.c kmod: fix resource leak in call_usermodehelper_pipe() 2010-01-11 09:34:04 -08:00
kprobes.c kprobes: Add mcount to the kprobes blacklist 2010-02-15 05:45:49 +01:00
ksysfs.c sched: Remove USER_SCHED 2010-01-21 13:40:18 +01:00
kthread.c kthread, sched: Remove reference to kthread_create_on_cpu 2010-02-09 11:47:39 +01:00
latencytop.c
lockdep.c rcu: Make lockdep_rcu_dereference() message less alarmist 2010-02-26 08:20:46 +01:00
lockdep_internals.h lockdep: BFS cleanup 2009-07-24 10:53:29 +02:00
lockdep_proc.c seq_file: constify seq_operations 2009-09-23 07:39:29 -07:00
lockdep_states.h
Makefile Merge branch 'x86-bootmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-03 08:15:05 -08:00
module.c Merge branch 'master' into percpu 2010-02-02 14:38:15 +09:00
mutex-debug.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
mutex-debug.h locking: Implement new raw_spinlock 2009-12-14 23:55:32 +01:00
mutex.c mutex: Better control mutex adaptive spinning config 2009-12-03 11:50:11 +01:00
mutex.h
notifier.c sched: Use lockdep-based checking on rcu_dereference() 2010-02-25 10:34:26 +01:00
ns_cgroup.c cgroups: let ss->can_attach and ss->attach do whole threadgroups at a time 2009-09-24 07:20:58 -07:00
nsproxy.c
padata.c padata: Generic parallelization/serialization interface 2010-01-06 19:47:10 +11:00
panic.c kmsg_dump: Dump on crash_kexec as well 2009-12-31 19:45:04 +00:00
params.c tree-wide: convert open calls to remove spaces to skip_spaces() lib function 2009-12-15 08:53:32 -08:00
perf_event.c Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-02-28 10:20:25 -08:00
pid.c sched: Use lockdep-based checking on rcu_dereference() 2010-02-25 10:34:26 +01:00
pid_namespace.c pidns: deny CLONE_PARENT|CLONE_NEWPID combination 2009-09-24 07:21:04 -07:00
pm_qos_params.c pm_qos: clean up racy global "name" variable 2009-10-14 15:31:10 +02:00
posix-cpu-timers.c posix-cpu-timers: optimize and document timer_create callback 2009-11-18 12:36:05 +01:00
posix-timers.c posix-timers.c: Don't export local functions 2010-02-05 14:54:10 +01:00
printk.c Merge branch 'next' into for-linus 2010-03-01 09:36:31 +11:00
profile.c kernel/profile.c: Switch /proc/irq/prof_cpu_mask to seq_file 2009-09-20 20:15:40 +02:00
ptrace.c ptrace: Fix ptrace_regset() comments and diagnose errors specifically 2010-02-23 13:45:26 -08:00
range.c x86: Change range end to start+size 2010-02-10 17:47:17 -08:00
rcupdate.c rcu: Export rcu_scheduler_active 2010-02-26 08:20:46 +01:00
rcutiny.c rcu: Eliminate unneeded function wrapping 2009-11-22 18:58:16 +01:00
rcutorture.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2010-03-03 07:34:18 -08:00
rcutree.c rcu: Fix accelerated grace periods for last non-dynticked CPU 2010-02-27 09:53:52 +01:00
rcutree.h rcu: Fix accelerated grace periods for last non-dynticked CPU 2010-02-27 09:53:52 +01:00
rcutree_plugin.h rcu: Fix accelerated GPs for last non-dynticked CPU 2010-02-27 09:53:53 +01:00
rcutree_trace.c rcu: Stop overflowing signed integers 2010-02-25 10:34:57 +01:00
relay.c const: constify remaining pipe_buf_operations 2009-12-16 07:20:05 -08:00
res_counter.c memcg: some modification to softlimit under hierarchical memory reclaim. 2009-10-01 16:11:13 -07:00
resource.c Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-03-03 09:11:02 -08:00
rtmutex-debug.c sched: Convert pi_lock to raw_spinlock 2009-12-14 23:55:33 +01:00
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c rtmutes: Convert rtmutex.lock to raw_spinlock 2009-12-14 23:55:33 +01:00
rtmutex.h
rtmutex_common.h
rwsem.c
sched.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2010-03-03 07:34:18 -08:00
sched_clock.c sched: Fix cpu_clock() in NMIs, on !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK 2009-12-15 09:04:36 +01:00
sched_cpupri.c sched: Use for_each_bit 2010-02-02 06:58:27 +01:00
sched_cpupri.h sched: Convert cpupri lock to raw_spinlock 2009-12-14 23:55:33 +01:00
sched_debug.c sched: Convert rq->lock to raw_spinlock 2009-12-14 23:55:33 +01:00
sched_fair.c sched: Fix SCHED_MC regression caused by change in sched cpu_power 2010-02-26 15:45:13 +01:00
sched_features.h sched: Discard some old bits 2009-12-09 10:03:07 +01:00
sched_idletask.c sched: Remove the sched_class load_balance methods 2010-01-21 13:40:09 +01:00
sched_rt.c sched: Change usage of rt_rq->rt_se to rt_rq->tg->rt_se[cpu] 2010-02-04 09:57:32 +01:00
sched_stats.h
seccomp.c
semaphore.c
signal.c Prioritize synchronous signals over 'normal' signals 2010-03-03 19:21:10 -08:00
slow-work-debugfs.c SLOW_WORK: Move slow_work's proc file to debugfs 2009-12-01 08:20:31 -08:00
slow-work.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/sysctl-2.6 2009-12-08 07:38:50 -08:00
slow-work.h SLOW_WORK: Move slow_work's proc file to debugfs 2009-12-01 08:20:31 -08:00
smp.c generic-ipi: Optimize accesses by using DEFINE_PER_CPU_SHARED_ALIGNED for IPI data 2010-01-18 09:02:59 +01:00
softirq.c hrtimer, softirq: Fix hrtimer->softirq trampoline 2010-02-03 18:17:40 +01:00
softlockup.c softlockup: Add sched_clock_tick() to avoid kernel warning on kgdb resume 2010-02-01 08:22:32 +01:00
spinlock.c locking: Cleanup the name space completely 2009-12-14 23:55:33 +01:00
srcu.c rcu: Introduce lockdep-based checking to RCU read-side primitives 2010-02-25 09:40:59 +01:00
stacktrace.c
stop_machine.c percpu: add __percpu sparse annotations to core kernel subsystems 2010-02-17 11:17:38 +09:00
sys.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2010-02-28 10:31:01 -08:00
sys_ni.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6 2009-12-08 07:55:01 -08:00
sysctl.c sparc: Support show_unhandled_signals. 2010-03-01 00:02:23 -08:00
sysctl_binary.c SYSCTL: Print binary sysctl warnings (nearly) only once 2009-12-23 21:00:20 +01:00
sysctl_check.c ipv4 05/05: add sysctl to accept packets with local source addresses 2009-12-03 12:14:38 -08:00
taskstats.c const: struct nla_policy 2010-02-18 14:30:18 -08:00
test_kprobes.c
time.c Revert "time: Remove xtime_cache" 2009-12-22 14:10:37 -08:00
timeconst.pl
timer.c perf: Fix perf_event_do_pending() fallback callsite 2010-01-21 13:40:39 +01:00
tracepoint.c trivial: fix typo "to to" in multiple files 2009-09-21 15:14:55 +02:00
tsacct.c
uid16.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
up.c
user-return-notifier.c core: Clean up user return notifers use of per_cpu 2009-12-02 10:22:59 +01:00
user.c sched: Remove USER_SCHED 2010-01-21 13:40:18 +01:00
user_namespace.c
utsname.c
utsname_sysctl.c sysctl kernel: Remove binary sysctl logic 2009-11-12 02:04:55 -08:00
wait.c locking, sched: Give waitqueue spinlocks their own lockdep classes 2009-08-10 14:43:09 +02:00
workqueue.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2009-12-10 09:35:44 -08:00