Michael Holzheu 93e13a360b kdump: fix crash_kexec()/smp_send_stop() race in panic() ... When two CPUs call panic at the same time there is a possible race condition that can stop kdump. The first CPU calls crash_kexec() and the second CPU calls smp_send_stop() in panic() before crash_kexec() finished on the first CPU. So the second CPU stops the first CPU and therefore kdump fails: 1st CPU: panic()->crash_kexec()->mutex_trylock(&kexec_mutex)-> do kdump 2nd CPU: panic()->crash_kexec()->kexec_mutex already held by 1st CPU ->smp_send_stop()-> stop 1st CPU (stop kdump) This patch fixes the problem by introducing a spinlock in panic that allows only one CPU to process crash_kexec() and the subsequent panic code. All other CPUs call the weak function panic_smp_self_stop() that stops the CPU itself. This function can be overloaded by architecture code. For example "tile" can use their lower-power "nap" instruction for that. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Acked-by: Chris Metcalf <cmetcalf@tilera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2012-01-12 20:13:11 -08:00
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debug	kdb: Make KDB use the new is_idle_task() API	2011-12-11 10:31:52 -08:00
events	Merge branch 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2012-01-09 12:59:24 -08:00
gcov	…
irq	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2012-01-08 13:21:22 -08:00
power	PM/Hibernate: do not count debug pages as savable	2012-01-10 16:30:42 -08:00
sched	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2012-01-11 22:52:48 -08:00
time	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial	2012-01-08 13:21:22 -08:00
trace	Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2012-01-08 12:19:57 -08:00
.gitignore	…
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	…
Kconfig.preempt	…
Makefile	…
acct.c	Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2012-01-08 12:19:57 -08:00
async.c	…
audit.c	audit: always follow va_copy() with va_end()	2012-01-08 14:15:21 -08:00
audit.h	…
audit_tree.c	…
audit_watch.c	…
auditfilter.c	…
auditsc.c	auditsc: propage umode_t	2012-01-03 22:55:17 -05:00
backtracetest.c	…
bounds.c	…
capability.c	…
cgroup.c	Merge branch 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2012-01-09 12:59:24 -08:00
cgroup_freezer.c	Merge branch 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2012-01-09 12:59:24 -08:00
compat.c	…
configs.c	…
cpu.c	Merge branch 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm	2012-01-08 13:10:57 -08:00
cpu_pm.c	…
cpuset.c	Merge branch 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2012-01-09 12:59:24 -08:00
crash_dump.c	…
cred.c	…
delayacct.c	…
dma.c	…
elfcore.c	…
exec_domain.c	…
exit.c	treewide: remove useless NORET_TYPE macro and uses	2012-01-12 20:13:03 -08:00
extable.c	…
fork.c	Merge branch 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux	2012-01-10 16:59:59 -08:00
freezer.c	freezer: kill unused set_freezable_with_signal()	2011-11-23 09:28:17 -08:00
futex.c	futex: Fix uninterruptible loop due to gate_area	2011-12-31 11:48:28 -08:00
futex_compat.c	…
groups.c	…
hrtimer.c	Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2011-11-28 08:43:52 -08:00
hung_task.c	hung_task: fix false positive during vfork	2012-01-03 16:14:32 -08:00
irq_work.c	…
itimer.c	[S390] cputime: add sparse checking and cleanup	2011-12-15 14:56:19 +01:00
jump_label.c	Merge remote-tracking branch 'tip/perf/core' into kvm-updates/3.3	2011-12-27 11:22:24 +02:00
kallsyms.c	…
kexec.c	kdump: crashk_res init check for /sys/kernel/kexec_crash_size	2012-01-12 20:13:11 -08:00
kfifo.c	…
kmod.c	Merge branch 'pm-sleep' into pm-for-linus	2011-12-25 23:42:20 +01:00
kprobes.c	kprobes: silence DEBUG_STRICT_USER_COPY_CHECKS=y warning	2012-01-12 20:13:02 -08:00
ksysfs.c	…
kthread.c	freezer: kill unused set_freezable_with_signal()	2011-11-23 09:28:17 -08:00
latencytop.c	…
lockdep.c	Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2012-01-06 08:02:58 -08:00
lockdep_internals.h	…
lockdep_proc.c	…
lockdep_states.h	…
module.c	…
mutex-debug.c	…
mutex-debug.h	…
mutex.c	…
mutex.h	…
notifier.c	…
nsproxy.c	…
padata.c	…
panic.c	kdump: fix crash_kexec()/smp_send_stop() race in panic()	2012-01-12 20:13:11 -08:00
params.c	…
pid.c	…
pid_namespace.c	…
posix-cpu-timers.c	[S390] cputime: add sparse checking and cleanup	2011-12-15 14:56:19 +01:00
posix-timers.c	…
printk.c	Merge branch 'core-printk-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2012-01-06 08:01:59 -08:00
profile.c	…
ptrace.c	ptrace: ensure JOBCTL_STOP_SIGMASK is not zero after detach	2012-01-04 15:01:59 -08:00
range.c	…
rcu.h	rcu: Deconfuse dynticks entry-exit tracing	2011-12-11 10:31:42 -08:00
rcupdate.c	rcu: Detect illegal rcu dereference in extended quiescent state	2011-12-11 10:31:30 -08:00
rcutiny.c	rcu: Augment rcu_batch_end tracing for idle and callback state	2011-12-11 10:32:22 -08:00
rcutiny_plugin.h	rcu: Apply ACCESS_ONCE() to rcu_boost() return value	2011-12-11 10:33:19 -08:00
rcutorture.c	rcu: Add rcutorture tests for srcu_read_lock_raw()	2011-12-11 10:32:21 -08:00
rcutree.c	rcu: Augment rcu_batch_end tracing for idle and callback state	2011-12-11 10:32:22 -08:00
rcutree.h	rcu: Keep invoking callbacks if CPU otherwise idle	2011-12-11 10:32:09 -08:00
rcutree_plugin.h	rcu: Apply ACCESS_ONCE() to rcu_boost() return value	2011-12-11 10:33:19 -08:00
rcutree_trace.c	rcu: Track idleness independent of idle tasks	2011-12-11 10:31:24 -08:00
relay.c	switch debugfs to umode_t	2012-01-03 22:54:56 -05:00
res_counter.c	resource cgroups: remove bogus cast	2011-12-13 07:43:08 -08:00
resource.c	…
rtmutex-debug.c	lockdep, rtmutex, bug: Show taint flags on error	2011-12-06 08:16:49 +01:00
rtmutex-debug.h	…
rtmutex-tester.c	rtmutex-tester: convert sysdev_class to a regular subsystem	2011-12-14 14:54:22 -08:00
rtmutex.c	Revert "rcu: Permit rt_mutex_unlock() with irqs disabled"	2011-12-11 10:33:18 -08:00
rtmutex.h	…
rtmutex_common.h	…
rwsem.c	…
seccomp.c	…
semaphore.c	…
signal.c	user namespace: make signal.c respect user namespaces	2012-01-10 16:30:54 -08:00
smp.c	…
softirq.c	rcu: Fix early call to rcu_idle_enter()	2011-12-11 10:31:38 -08:00
spinlock.c	…
srcu.c	…
stacktrace.c	…
stop_machine.c	…
sys.c	[S390] cputime: add sparse checking and cleanup	2011-12-15 14:56:19 +01:00
sys_ni.c	…
sysctl.c	x86: Panic on detection of stack overflow	2011-12-05 11:37:47 +01:00
sysctl_binary.c	binary_sysctl(): fix memory leak	2011-12-20 10:25:04 -08:00
sysctl_check.c	…
taskstats.c	…
test_kprobes.c	…
time.c	…
timeconst.pl	…
timer.c	Merge branch 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2012-01-06 07:53:34 -08:00
tracepoint.c	…
tsacct.c	[S390] cputime: add sparse checking and cleanup	2011-12-15 14:56:19 +01:00
uid16.c	…
up.c	…
user-return-notifier.c	…
user.c	…
user_namespace.c	…
utsname.c	…
utsname_sysctl.c	…
wait.c	lockdep/waitqueues: Add better annotation	2011-12-21 10:07:39 +01:00
watchdog.c	…
workqueue.c	workqueue: make alloc_workqueue() take printf fmt and args for name	2012-01-10 16:30:54 -08:00
workqueue_sched.h	…