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c5ed5145591774bd9a2960ba4ca45a02fc70aad1
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Peter Zijlstra c5ed514559 perf: Fix contexted inheritance 
Linus reported that the RCU lockdep annotation bits triggered for this
rcu_dereference() because we're not holding rcu_read_lock().

Going over the code I cannot convince myself its correct:

 - holding a ref on the parent_ctx, doesn't avoid it being uncloned
   concurrently (as the comment says), so we can race with a free.

 - holding parent_ctx->mutex doesn't avoid the above free from taking
   place either, it would at best avoid parent_ctx from being freed.

I.e. the warning is correct. To fix the bug, serialize against the
unclone_ctx() call by extending the reach of the parent_ctx->lock.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-18 15:10:35 +01:00
..
debug
kdb: fix crash when KDB_BASE_CMD_MAX is exceeded
2010-11-17 13:54:57 -06:00
gcov
llseek: automatically add .llseek fop
2010-10-15 15:53:27 +02:00
irq
Merge branch 'linus' into sched/core
2010-12-08 20:15:29 +01:00
power
perf: Add calls to suspend trace point
2011-01-05 21:25:28 +01:00
time
hrtimers: Convert hrtimers to use timerlist infrastructure
2010-12-10 11:54:35 -08:00
trace
tracing: Remove syscall_exit_fields
2011-01-14 18:06:35 -05:00
.gitignore
…
acct.c
pass a struct path to vfs_statfs
2010-08-09 16:48:42 -04:00
async.c
async: use workqueue for worker pool
2010-07-14 11:29:46 +02:00
audit_tree.c
in untag_chunk() we need to do alloc_chunk() a bit earlier
2010-10-30 02:18:32 -04:00
audit_watch.c
audit: make functions static
2010-10-30 01:42:19 -04:00
audit.c
audit: Use rcu for task lookup protection
2010-10-30 08:45:42 -04:00
audit.h
audit: make functions static
2010-10-30 01:42:19 -04:00
auditfilter.c
Audit: add support to match lsm labels on user audit messages
2010-10-30 01:41:57 -04:00
auditsc.c
audit mmap
2010-10-30 08:45:43 -04:00
backtracetest.c
…
bounds.c
…
capability.c
…
cgroup_freezer.c
cgroup_freezer: update_freezer_state() does incorrect state transitions
2010-10-27 18:03:08 -07:00
cgroup.c
convert cgroup and cpuset
2010-10-29 04:17:06 -04:00
compat.c
compat: Make compat_alloc_user_space() incorporate the access_ok()
2010-09-14 16:08:45 -07:00
configs.c
llseek: automatically add .llseek fop
2010-10-15 15:53:27 +02:00
cpu.c
Merge branches 'x86-alternatives-for-linus', 'x86-fpu-for-linus', 'x86-hwmon-for-linus', 'x86-paravirt-for-linus', 'core-locking-for-linus' and 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2011-01-06 11:11:50 -08:00
cpuset.c
convert cgroup and cpuset
2010-10-29 04:17:06 -04:00
cred.c
signals: move cred_guard_mutex from task_struct to signal_struct
2010-10-27 18:03:12 -07:00
delayacct.c
…
dma.c
…
elfcore.c
…
exec_domain.c
sys_personality: remove the bogus checks in sys_personality()->__set_personality() path
2010-08-09 20:45:05 -07:00
exit.c
perf_events: Move code around to prepare for cgroup
2011-01-07 15:08:50 +01:00
extable.c
…
fork.c
Merge commit 'v2.6.37' into sched/core
2011-01-05 14:14:46 +01:00
freezer.c
…
futex_compat.c
futex: Address compiler warnings in exit_robust_list
2010-11-10 13:27:50 +01:00
futex.c
futex: Add futex_q static initializer
2010-11-10 15:01:34 +01:00
groups.c
kernel/groups.c: fix integer overflow in groups_search
2010-09-09 18:57:24 -07:00
hrtimer.c
Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2011-01-06 10:42:43 -08:00
hung_task.c
lockup detector: Fix grammar by adding a missing "to" in the comments
2010-08-17 09:11:52 +02:00
hw_breakpoint.c
perf: Dynamic pmu types
2010-12-16 11:36:43 +01:00
irq_work.c
irq_work: Drop cmpxchg() result
2010-11-18 13:18:47 +01:00
itimer.c
…
jump_label.c
jump label: Make arch_jump_label_text_poke_early() optional
2010-10-29 12:56:13 -04:00
kallsyms.c
Revert "kernel: make /proc/kallsyms mode 400 to reduce ease of attacking"
2010-11-19 11:54:40 -08:00
Kconfig.freezer
…
Kconfig.hz
…
Kconfig.locks
…
Kconfig.preempt
…
kexec.c
use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages
2010-10-26 16:52:13 -07:00
kfifo.c
kfifo: fix scatterlist usage
2010-10-01 10:50:58 -07:00
kmod.c
Make do_execve() take a const filename pointer
2010-08-17 18:07:43 -07:00
kprobes.c
kprobes: Use text_poke_smp_batch for unoptimizing
2010-12-06 17:59:32 +01:00
ksysfs.c
…
kthread.c
Merge commit 'v2.6.37' into sched/core
2011-01-05 14:14:46 +01:00
latencytop.c
latencytop: fix per task accumulator
2010-11-12 07:55:31 -08:00
lockdep_internals.h
…
lockdep_proc.c
locking, lockdep: Convert sprintf_symbol to %pS
2010-11-10 10:23:58 +01:00
lockdep_states.h
…
lockdep.c
lockdep: Check the depth of subclass
2010-10-18 18:44:26 +02:00
Makefile
tracing: Fix TRACE_EVENT power tracepoint creation
2011-01-07 23:26:29 -05:00
module.c
module: Move RO/NX module protection to after ftrace module update
2010-12-23 09:56:00 -05:00
mutex-debug.c
…
mutex-debug.h
…
mutex.c
mutexes, sched: Introduce arch_mutex_cpu_relax()
2010-11-26 15:05:34 +01:00
mutex.h
…
notifier.c
…
ns_cgroup.c
cgroup: notify ns_cgroup deprecated
2010-10-27 18:03:09 -07:00
nsproxy.c
…
padata.c
Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
2010-08-04 15:23:14 -07:00
panic.c
lib/bug.c: add oops end marker to WARN implementation
2010-08-11 08:59:22 -07:00
params.c
param: locking for kernel parameters
2010-08-11 23:04:20 +09:30
perf_event.c
perf: Fix contexted inheritance
2011-01-18 15:10:35 +01:00
pid_namespace.c
…
pid.c
Add RCU check for find_task_by_vpid().
2010-08-19 17:18:02 -07:00
pm_qos_params.c
PM / PM QoS: Fix reversed min and max
2010-11-15 22:45:22 +01:00
posix-cpu-timers.c
posix-cpu-timers: Rcu_read_lock/unlock protect find_task_by_vpid call
2010-11-10 13:07:06 +01:00
posix-timers.c
posix-timers: Annotate lock_timer()
2010-10-21 17:30:06 +02:00
printk.c
printk: Use this_cpu_{read|write} api on printk_pending
2010-12-08 20:16:01 +01:00
profile.c
llseek: automatically add .llseek fop
2010-10-15 15:53:27 +02:00
ptrace.c
signals: move cred_guard_mutex from task_struct to signal_struct
2010-10-27 18:03:12 -07:00
range.c
kernel/range.c: fix clean_sort_range() for the case of full array
2010-11-12 07:55:31 -08:00
rcupdate.c
Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-2.6-rcu into core/rcu
2010-10-07 09:43:11 +02:00
rcutiny_plugin.h
rcu: Distinguish between boosting and boosted
2010-11-29 22:01:56 -08:00
rcutiny.c
rcu: add tracing for TINY_RCU and TINY_PREEMPT_RCU
2010-11-29 22:01:55 -08:00
rcutorture.c
rcu: add priority-inversion testing to rcutorture
2010-10-07 10:41:08 -07:00
rcutree_plugin.h
rcu: increase synchronize_sched_expedited() batching
2010-12-17 12:34:08 -08:00
rcutree_trace.c
rcu,cleanup: simplify the code when cpu is dying
2010-11-29 22:01:58 -08:00
rcutree.c
rcu: reduce __call_rcu()-induced contention on rcu_node structures
2010-12-17 12:34:49 -08:00
rcutree.h
rcu: limit rcu_node leaf-level fanout
2010-12-17 12:34:20 -08:00
relay.c
Clean up relay_alloc_page_array() slightly by using vzalloc rather than vmalloc and memset
2010-11-05 08:21:34 -07:00
res_counter.c
…
resource.c
resources: add arch hook for preventing allocation in reserved areas
2010-12-17 10:01:09 -08:00
rtmutex_common.h
…
rtmutex-debug.c
…
rtmutex-debug.h
…
rtmutex-tester.c
rtmutex-tester: make it build without BKL
2010-10-19 11:29:56 +02:00
rtmutex.c
…
rtmutex.h
…
rwsem.c
…
sched_autogroup.c
sched, autogroup: Fix potential access to freed memory
2011-01-04 15:10:34 +01:00
sched_autogroup.h
sched: Add 'autogroup' scheduling feature: automated per session task groups
2010-11-30 16:03:35 +01:00
sched_clock.c
sched: Add some clock info to sched_debug
2010-11-23 10:29:08 +01:00
sched_cpupri.c
sched: No need for bootmem special cases
2010-07-17 12:06:22 +02:00
sched_cpupri.h
sched: No need for bootmem special cases
2010-07-17 12:06:22 +02:00
sched_debug.c
sched: Add 'autogroup' scheduling feature: automated per session task groups
2010-11-30 16:03:35 +01:00
sched_fair.c
sched: Fix interactivity bug by charging unaccounted run-time on entity re-weight
2010-12-19 16:36:30 +01:00
sched_features.h
sched: Rewrite tg_shares_up)
2010-11-18 13:27:46 +01:00
sched_idletask.c
…
sched_rt.c
sched: Implement on-demand (active) cfs_rq list
2010-11-18 13:27:47 +01:00
sched_stats.h
sched_stat: Update sched_info_queue/dequeue() code comments
2010-10-24 13:29:01 +02:00
sched_stoptask.c
sched: Fix cross-sched-class wakeup preemption
2010-11-11 14:37:23 +01:00
sched.c
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2011-01-06 10:23:33 -08:00
seccomp.c
…
semaphore.c
…
signal.c
signals: annotate lock context change on ptrace_stop()
2010-10-27 18:03:12 -07:00
smp.c
Typedef SMP call function pointer
2010-10-27 17:28:36 +01:00
softirq.c
Merge commit 'v2.6.37-rc2' into sched/core
2010-11-18 13:22:26 +01:00
spinlock.c
…
srcu.c
rcu: Make synchronize_srcu_expedited() fast if running readers
2010-11-29 22:02:40 -08:00
stacktrace.c
…
stop_machine.c
stop_machine: convert cpu notifier to return encapsulate errno value
2010-10-26 16:52:15 -07:00
sys_ni.c
powerpc: define a compat_sys_recv cond_syscall
2010-09-23 17:03:55 +10:00
sys.c
sched: Add 'autogroup' scheduling feature: automated per session task groups
2010-11-30 16:03:35 +01:00
sysctl_binary.c
x86, NMI: Add back unknown_nmi_panic and nmi_watchdog sysctls
2010-12-10 00:01:06 +01:00
sysctl_check.c
sysctl: min/max bounds are optional
2010-10-15 14:42:24 -07:00
sysctl.c
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2011-01-06 10:23:33 -08:00
taskstats.c
taskstats: pad taskstats netlink response for aligment issues on ia64
2010-12-22 19:43:34 -08:00
test_kprobes.c
kprobes: Fix selftest to clear flags field for reusing probes
2010-10-14 08:55:27 +02:00
time.c
time: Kill off CONFIG_GENERIC_TIME
2010-07-27 12:40:54 +02:00
timeconst.pl
…
timer.c
Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2011-01-06 10:42:43 -08:00
tracepoint.c
jump_label: Use more consistent naming
2010-10-18 19:58:56 +02:00
tsacct.c
taskstats: use real microsecond granularity for CPU times
2010-10-27 18:03:17 -07:00
uid16.c
…
up.c
…
user_namespace.c
user_ns: Introduce user_nsmap_uid and user_ns_map_gid.
2010-06-16 14:55:34 -07:00
user-return-notifier.c
…
user.c
fix freeing user_struct in user cache
2010-12-29 11:31:38 -08:00
utsname_sysctl.c
…
utsname.c
…
wait.c
docbook: add more wait/wake/completion to device-drivers docbook
2010-10-26 17:32:41 -07:00
watchdog.c
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
2011-01-06 10:23:33 -08:00
workqueue_sched.h
workqueue: implement concurrency managed dynamic worker pool
2010-06-29 10:07:14 +02:00
workqueue.c
workqueue: It is likely that WORKER_NOT_RUNNING is true
2010-12-14 15:05:54 +01:00