Milton Miller 02c85f0701 smp_call_function_many: handle concurrent clearing of mask ... commit 723aae25d5 upstream. Mike Galbraith reported finding a lockup ("perma-spin bug") where the cpumask passed to smp_call_function_many was cleared by other cpu(s) while a cpu was preparing its call_data block, resulting in no cpu to clear the last ref and unlock the block. Having cpus clear their bit asynchronously could be useful on a mask of cpus that might have a translation context, or cpus that need a push to complete an rcu window. Instead of adding a BUG_ON and requiring yet another cpumask copy, just detect the race and handle it. Note: arch_send_call_function_ipi_mask must still handle an empty cpumask because the data block is globally visible before the that arch callback is made. And (obviously) there are no guarantees to which cpus are notified if the mask is changed during the call; only cpus that were online and had their mask bit set during the whole call are guaranteed to be called. Reported-by: Mike Galbraith <efault@gmx.de> Reported-by: Jan Beulich <JBeulich@novell.com> Acked-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>		2011-03-23 13:16:55 -07:00
..
gcov	gcov: fix null-pointer dereference for certain module types	2010-09-20 13:17:53 -07:00
irq	genirq: Disable the SHIRQ_DEBUG call in request_threaded_irq for now	2011-03-02 09:46:55 -05:00
power	PM / Hibernate: Return error code when alloc_image_page() fails	2011-03-02 09:46:50 -05:00
time	clockevents: Prevent oneshot mode when broadcast device is periodic	2011-03-07 15:17:54 -08:00
trace	ftrace: Fix memory leak with function graph and cpu hotplug	2011-03-23 13:16:39 -07:00
.gitignore
acct.c	bsdacct: fix uid/gid misreporting	2009-12-18 14:03:52 -08:00
async.c
audit_tree.c	fix more leaks in audit_tree.c tag_chunk()	2010-01-18 10:19:50 -08:00
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c	sched: Remove remaining USER_SCHED code	2011-02-17 15:37:19 -08:00
cgroup_freezer.c	Freezer: Fix buggy resume test for tasks frozen with cgroup freezer	2010-04-26 07:41:17 -07:00
cgroup.c	cgroups: fix 2.6.32 regression causing BUG_ON() in cgroup_diput()	2010-01-18 10:19:32 -08:00
compat.c	compat: Make compat_alloc_user_space() incorporate the access_ok()	2010-09-20 13:17:57 -07:00
configs.c
cpu.c	sched: _cpu_down(): Don't play with current->cpus_allowed	2010-09-20 13:18:08 -07:00
cpuset.c	cpuset: add a missing unlock in cpuset_write_resmask()	2011-03-14 14:29:52 -07:00
cred.c	CRED: Fix memory and refcount leaks upon security_prepare_creds() failure	2011-03-02 09:46:39 -05:00
delayacct.c
dma.c
exec_domain.c
exit.c	sched: Remove remaining USER_SCHED code	2011-02-17 15:37:19 -08:00
extable.c
fork.c	sched: Fix fork vs hotplug vs cpuset namespaces	2010-09-20 13:18:02 -07:00
freezer.c
futex_compat.c
futex.c	futex: Fix errors in nested key ref-counting	2010-11-22 10:47:31 -08:00
groups.c	kernel/groups.c: fix integer overflow in groups_search	2010-09-20 13:17:54 -07:00
hrtimer.c	hrtimer: Preserve timer state in remove_hrtimer()	2010-10-28 21:44:01 -07:00
hung_task.c
itimer.c
kallsyms.c
Kconfig.freezer
Kconfig.hz
Kconfig.preempt
kexec.c
kfifo.c
kgdb.c
kmod.c
kprobes.c	const: constify remaining file_operations	2009-10-01 16:11:11 -07:00
ksysfs.c	sched: Remove USER_SCHED	2011-02-17 15:37:19 -08:00
kthread.c	cpuset: fix the problem that cpuset_mem_spread_node() returns an offline node	2010-04-01 15:58:46 -07:00
latencytop.c	latencytop: fix per task accumulator	2010-12-09 13:26:51 -08:00
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c	Revert "lockdep: fix incorrect percpu usage"	2010-06-01 09:45:46 -07:00
Makefile	SLOW_WORK: Move slow_work's proc file to debugfs	2009-12-01 08:20:31 -08:00
module.c	dynamic debug: move ddebug_remove_module() down into free_module()	2010-08-02 10:20:47 -07:00
mutex-debug.c	headers: remove sched.h from interrupt.h	2009-10-11 11:20:58 -07:00
mutex-debug.h
mutex.c	mutex: Fix optimistic spinning vs. BKL	2010-07-05 11:10:31 -07:00
mutex.h
notifier.c
ns_cgroup.c
nsproxy.c
panic.c	Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2009-10-08 12:16:35 -07:00
params.c	param: fix setting arrays of bool	2009-10-29 08:56:20 +10:30
perf_event.c	perf: Handle stopped state with tracepoints	2011-03-23 13:16:52 -07:00
pid_namespace.c
pid.c
pm_qos_params.c
posix-cpu-timers.c
posix-timers.c	posix_timer: Fix error path in timer_create	2010-07-05 11:10:30 -07:00
printk.c	nohz: Fix printk_needs_cpu() return value on offline cpus	2011-01-07 14:43:03 -08:00
profile.c	profile: fix stats and data leakage	2010-05-26 14:29:18 -07:00
ptrace.c	ptrace: use safer wake up on ptrace_detach()	2011-02-17 15:37:03 -08:00
rcupdate.c	rcu: Move rcu_barrier() to rcutree	2009-10-07 08:11:20 +02:00
rcutorture.c
rcutree_plugin.h	rcu: Remove inline from forward-referenced functions	2009-12-18 14:03:04 -08:00
rcutree_trace.c	rcu: Make hot-unplugged CPU relinquish its own RCU callbacks	2009-10-07 08:11:20 +02:00
rcutree.c	rcu: Fix note_new_gpnum() uses of ->gpnum	2009-12-18 14:03:01 -08:00
rcutree.h	rcu: Remove inline from forward-referenced functions	2009-12-18 14:03:04 -08:00
relay.c
res_counter.c	memcg: some modification to softlimit under hierarchical memory reclaim.	2009-10-01 16:11:13 -07:00
resource.c
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_clock.c	sched: Fix cpu_clock() in NMIs, on !CONFIG_HAVE_UNSTABLE_SCHED_CLOCK	2010-01-22 15:18:30 -08:00
sched_cpupri.c
sched_cpupri.h
sched_debug.c	sched: Remove remaining USER_SCHED code	2011-02-17 15:37:19 -08:00
sched_fair.c	sched: Fix wake_affine() vs RT tasks	2011-02-17 15:37:30 -08:00
sched_features.h	sched: Remove irq time from available CPU power	2011-02-17 15:37:27 -08:00
sched_idletask.c	sched: Fix TASK_WAKING vs fork deadlock	2010-09-20 13:18:09 -07:00
sched_rt.c	sched: Do not account irq time to current task	2011-02-17 15:37:26 -08:00
sched_stats.h
sched.c	ftrace: Fix memory leak with function graph and cpu hotplug	2011-03-23 13:16:39 -07:00
seccomp.c
semaphore.c
signal.c	signals: check_kill_permission(): don't check creds if same_thread_group()	2010-07-05 11:10:56 -07:00
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	slow-work: use get_ref wrapper instead of directly calling get_ref	2010-08-10 10:20:45 -07:00
slow-work.h	SLOW_WORK: Move slow_work's proc file to debugfs	2009-12-01 08:20:31 -08:00
smp.c	smp_call_function_many: handle concurrent clearing of mask	2011-03-23 13:16:55 -07:00
softirq.c	sched: Call tick_check_idle before __irq_enter	2011-02-17 15:37:27 -08:00
softlockup.c	softlockup: Stop spurious softlockup messages due to overflow	2010-04-01 15:58:47 -07:00
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c	sched: Remove USER_SCHED	2011-02-17 15:37:19 -08:00
sysctl_check.c	NET: fix oops at bootime in sysctl code	2010-02-09 04:51:02 -08:00
sysctl.c	kernel/sysctl.c: fix stable merge error in NOMMU mmap_min_addr	2010-01-18 10:19:49 -08:00
taskstats.c
test_kprobes.c
time.c
timeconst.pl
timer.c	nohz: Fix get_next_timer_interrupt() vs cpu hotplug	2011-01-07 14:43:03 -08:00
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c
user.c	kernel/user.c: add lock release annotation on free_user()	2011-02-17 15:37:31 -08:00
utsname_sysctl.c
utsname.c
wait.c
workqueue.c	workqueue: fix race condition in schedule_on_each_cpu()	2009-11-17 17:40:33 -08:00