Thomas Gleixner
f2530dc71c
kthread: Prevent unpark race which puts threads on the wrong cpu
...
The smpboot threads rely on the park/unpark mechanism which binds per
cpu threads on a particular core. Though the functionality is racy:
CPU0 CPU1 CPU2
unpark(T) wake_up_process(T)
clear(SHOULD_PARK) T runs
leave parkme() due to !SHOULD_PARK
bind_to(CPU2) BUG_ON(wrong CPU)
We cannot let the tasks move themself to the target CPU as one of
those tasks is actually the migration thread itself, which requires
that it starts running on the target cpu right away.
The solution to this problem is to prevent wakeups in park mode which
are not from unpark(). That way we can guarantee that the association
of the task to the target cpu is working correctly.
Add a new task state (TASK_PARKED) which prevents other wakeups and
use this state explicitly for the unpark wakeup.
Peter noticed: Also, since the task state is visible to userspace and
all the parked tasks are still in the PID space, its a good hint in ps
and friends that these tasks aren't really there for the moment.
The migration thread has another related issue.
CPU0 CPU1
Bring up CPU2
create_thread(T)
park(T)
wait_for_completion()
parkme()
complete()
sched_set_stop_task()
schedule(TASK_PARKED)
The sched_set_stop_task() call is issued while the task is on the
runqueue of CPU1 and that confuses the hell out of the stop_task class
on that cpu. So we need the same synchronizaion before
sched_set_stop_task().
Reported-by: Dave Jones <davej@redhat.com>
Reported-and-tested-by: Dave Hansen <dave@sr71.net>
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Acked-by: Peter Ziljstra <peterz@infradead.org>
Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: dhillf@gmail.com
Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1304091635430.21884@ionos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-04-12 14:18:43 +02:00
..
debug
KGDB/KDB fixes and cleanups
2013-03-02 08:31:39 -08:00
events
perf: Generate EXIT event only once per task context
2013-03-18 09:47:33 +01:00
gcov
kernel/gcov: remove depends on CONFIG_EXPERIMENTAL
2013-01-11 11:39:33 -08:00
irq
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2013-02-26 20:16:07 -08:00
power
Driver core patches for 3.9-rc1
2013-02-21 12:05:51 -08:00
sched
Merge branch 'for-3.9/core' of git://git.kernel.dk/linux-block
2013-02-28 12:52:24 -08:00
time
clockevents: Don't allow dummy broadcast timers
2013-03-07 17:16:11 +01:00
trace
tracing: Fix double free when function profile init failed
2013-04-09 18:54:04 -04:00
.gitignore
acct.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2013-02-26 20:16:07 -08:00
async.c
Merge branch 'for-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2013-02-19 22:01:33 -08:00
audit.c
kernel/audit.c: avoid negative sleep durations
2013-01-11 14:54:56 -08:00
audit.h
audit: optimize audit_compare_dname_path
2012-10-12 00:32:02 -04:00
audit_tree.c
audit: catch possible NULL audit buffers
2013-01-11 14:54:55 -08:00
audit_watch.c
audit: catch possible NULL audit buffers
2013-01-11 14:54:55 -08:00
auditfilter.c
audit: fix auditfilter.c kernel-doc warnings
2013-01-10 14:35:23 -08:00
auditsc.c
audit: catch possible NULL audit buffers
2013-01-11 14:54:55 -08:00
backtracetest.c
bounds.c
capability.c
cgroup.c
hlist: drop the node parameter from iterators
2013-02-27 19:10:24 -08:00
cgroup_freezer.c
cgroup: rename ->create/post_create/pre_destroy/destroy() to ->css_alloc/online/offline/free()
2012-11-19 08:13:38 -08:00
compat.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
2013-02-23 18:50:11 -08:00
configs.c
context_tracking.c
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-02-19 18:19:48 -08:00
cpu.c
Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-02-19 19:04:55 -08:00
cpu_pm.c
cpuset.c
Merge branch 'for-3.9-cpuset' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
2013-02-20 09:18:31 -08:00
crash_dump.c
cred.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
2012-12-18 10:55:28 -08:00
delayacct.c
cputime: Use accessors to read task cputime stats
2013-01-27 19:23:31 +01:00
dma.c
elfcore.c
exec_domain.c
exit.c
Revert "lockdep: check that no locks held at freeze time"
2013-03-31 11:38:33 -07:00
extable.c
fork.c
userns: Don't allow CLONE_NEWUSER | CLONE_FS
2013-03-13 15:00:20 -07:00
freezer.c
freezer: change ptrace_stop/do_signal_stop to use freezable_schedule()
2012-10-26 14:27:49 -07:00
futex.c
futex: fix kernel-doc notation and spello
2013-03-12 20:42:10 -07:00
futex_compat.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
2013-02-23 18:50:11 -08:00
groups.c
hrtimer.c
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-02-19 19:05:45 -08:00
hung_task.c
irq_work.c
Merge branch 'nohz/printk-v8' into irq/core
2013-02-05 00:48:46 +01:00
itimer.c
jump_label.c
jump_label: Export jump_label_rate_limit()
2012-08-06 19:00:35 +03:00
kallsyms.c
kcmp.c
kcmp: include linux/ptrace.h
2012-12-20 17:40:19 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
locking: Adjust spin lock inlining Kconfig options
2012-09-13 17:56:13 +02:00
Kconfig.preempt
kexec.c
kexec: avoid freeing NULL pointer in image_crash_alloc()
2013-02-27 19:10:12 -08:00
kmod.c
Merge branch 'master' into for-3.9-async
2013-01-23 09:31:01 -08:00
kprobes.c
hlist: drop the node parameter from iterators
2013-02-27 19:10:24 -08:00
ksysfs.c
Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2012-12-11 18:10:49 -08:00
kthread.c
kthread: Prevent unpark race which puts threads on the wrong cpu
2013-04-12 14:18:43 +02:00
latencytop.c
lglock.c
lockdep.c
Revert "lockdep: check that no locks held at freeze time"
2013-03-31 11:38:33 -07:00
lockdep_internals.h
lockdep_proc.c
lockdep: Use KSYM_NAME_LEN'ed buffer for __get_key_name()
2012-10-24 12:39:09 +02:00
lockdep_states.h
Makefile
Merge branch 'akpm' (final batch from Andrew)
2013-02-27 20:58:09 -08:00
modsign_certificate.S
MODSIGN: Avoid using .incbin in C source
2012-12-14 13:06:44 +10:30
modsign_pubkey.c
keys: use keyring_alloc() to create module signing keyring
2012-12-20 17:40:21 -08:00
module-internal.h
MODSIGN: Move the magic string to the end of a module and eliminate the search
2012-10-19 17:30:40 -07:00
module.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2013-02-26 20:16:07 -08:00
module_signing.c
MODSIGN: Don't use enum-type bitfields in module signature info block
2012-12-05 11:27:24 +10:30
mutex-debug.c
mutex-debug.h
mutex.c
sched/rt: Move rt specific bits into new header file
2013-02-07 20:51:08 +01:00
mutex.h
notifier.c
nsproxy.c
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
2013-02-26 20:16:07 -08:00
padata.c
padata: use __this_cpu_read per-cpu helper
2012-12-06 17:16:23 +08:00
panic.c
taint: add explicit flag to show whether lock dep is still OK.
2013-01-21 17:17:57 +10:30
params.c
pid.c
hlist: drop the node parameter from iterators
2013-02-27 19:10:24 -08:00
pid_namespace.c
pid: Handle the exit of a multi-threaded init.
2013-03-26 03:41:23 -07:00
posix-cpu-timers.c
Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-02-19 19:05:45 -08:00
posix-timers.c
posix-timers: convert to idr_alloc()
2013-02-27 19:10:19 -08:00
printk.c
printk: Provide a wake_up_klogd() off-case
2013-03-22 16:41:20 -07:00
profile.c
profiling: Remove unused timer hook
2013-01-24 15:37:26 +01:00
ptrace.c
uprobes: Add exports for module use
2013-02-08 17:47:13 +01:00
range.c
rcu.h
rcu: Provide RCU CPU stall warnings for tiny RCU
2013-01-28 22:06:21 -08:00
rcupdate.c
Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD
2013-01-28 22:25:21 -08:00
rcutiny.c
Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD
2013-01-28 22:25:21 -08:00
rcutiny_plugin.h
rcu: Provide RCU CPU stall warnings for tiny RCU
2013-01-28 22:06:21 -08:00
rcutorture.c
rcu: Allow rcutorture to be built at low optimization levels
2013-02-04 12:18:20 -08:00
rcutree.c
Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD
2013-01-28 22:25:21 -08:00
rcutree.h
Merge branches 'doctorture.2013.01.29a', 'fixes.2013.01.26a', 'tagcb.2013.01.24a' and 'tiny.2013.01.29b' into HEAD
2013-01-28 22:25:21 -08:00
rcutree_plugin.h
rcu: Make rcu_nocb_poll an early_param instead of module_param
2013-01-08 14:12:19 -08:00
rcutree_trace.c
rcu: Separate accounting of callbacks from callback-free CPUs
2012-11-16 10:05:57 -08:00
relay.c
new helper: file_inode(file)
2013-02-22 23:31:31 -05:00
res_counter.c
res_counter: return amount of charges after res_counter_uncharge()
2012-12-18 15:02:12 -08:00
resource.c
kernel/resource.c: fix stack overflow in __reserve_region_with_split()
2012-10-06 03:05:31 +09:00
rtmutex-debug.c
sched/rt: Move rt specific bits into new header file
2013-02-07 20:51:08 +01:00
rtmutex-debug.h
rtmutex-tester.c
sched/rt: Move rt specific bits into new header file
2013-02-07 20:51:08 +01:00
rtmutex.c
sched/rt: Move rt specific bits into new header file
2013-02-07 20:51:08 +01:00
rtmutex.h
rtmutex_common.h
rwsem.c
lockdep, rwsem: provide down_write_nest_lock()
2013-01-11 14:54:55 -08:00
seccomp.c
seccomp: Make syscall skipping and nr changes more consistent
2012-10-02 21:14:29 +10:00
semaphore.c
signal.c
kernel/signal.c: use __ARCH_HAS_SA_RESTORER instead of SA_RESTORER
2013-03-13 15:21:45 -07:00
smp.c
smp: make smp_call_function_many() use logic similar to smp_call_function_single()
2013-02-21 17:22:20 -08:00
smpboot.c
kthread: Prevent unpark race which puts threads on the wrong cpu
2013-04-12 14:18:43 +02:00
smpboot.h
smpboot: Provide infrastructure for percpu hotplug threads
2012-08-13 17:01:07 +02:00
softirq.c
Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-03-05 18:10:04 -08:00
spinlock.c
srcu.c
srcu: use ACCESS_ONCE() to access sp->completed in srcu_read_lock()
2013-02-07 15:19:36 -08:00
stacktrace.c
stop_machine.c
stop_machine: Mark per cpu stopper enabled early
2013-02-26 22:25:17 +01:00
sys.c
PM / reboot: call syscore_shutdown() after disable_nonboot_cpus()
2013-04-08 22:10:40 +02:00
sys_ni.c
module: add syscall to load module from fd
2012-12-14 13:05:22 +10:30
sysctl.c
Initial ARC Linux port with some fixes on top for 3.9-rc1
2013-03-02 07:58:56 -08:00
sysctl_binary.c
sysctl: fix null checking in bin_dn_node_address()
2013-02-27 19:10:21 -08:00
task_work.c
task_work: task_work_add() should not succeed after exit_task_work()
2012-09-13 16:47:34 +02:00
taskstats.c
taskstats: cgroupstats_user_cmd() may leak on error
2012-10-06 03:05:31 +09:00
test_kprobes.c
time.c
time: don't inline EXPORT_SYMBOL functions
2013-02-21 17:22:19 -08:00
timeconst.bc
kernel: Replace timeconst.pl with a bc script
2013-02-16 23:17:25 +01:00
timer.c
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-02-19 18:19:48 -08:00
tracepoint.c
hlist: drop the node parameter from iterators
2013-02-27 19:10:24 -08:00
tsacct.c
cputime: Use accessors to read task cputime stats
2013-01-27 19:23:31 +01:00
uid16.c
up.c
user-return-notifier.c
hlist: drop the node parameter from iterators
2013-02-27 19:10:24 -08:00
user.c
userns: Restrict when proc and sysfs can be mounted
2013-03-27 07:50:08 -07:00
user_namespace.c
userns: Restrict when proc and sysfs can be mounted
2013-03-27 07:50:08 -07:00
utsname.c
kernel/utsname.c: fix wrong comment about clone_uts_ns()
2013-02-27 19:10:22 -08:00
utsname_sysctl.c
kernel/utsname_sysctl.c: put get/get_uts() into CONFIG_PROC_SYSCTL code block
2013-02-27 19:10:22 -08:00
wait.c
propagate name change to comments in kernel source
2012-12-06 10:39:54 +01:00
watchdog.c
Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
2013-02-22 19:25:09 -08:00
workqueue.c
Merge branch 'for-3.9-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
2013-03-18 18:47:07 -07:00
workqueue_internal.h
workqueue: rename cpu_workqueue to pool_workqueue
2013-02-13 19:29:12 -08:00