Repository files (latest commit first)

Filename	Latest commit message	Latest commit date
Paul Mackerras 220b140b52 perf_event: Fix oops triggered by cpu offline/online ... Anton Blanchard found that he could reliably make the kernel hit a BUG_ON in the slab allocator by taking a cpu offline and then online while a system-wide perf record session was running. The reason is that when the cpu comes up, we completely reinitialize the ctx field of the struct perf_cpu_context for the cpu. If there is a system-wide perf record session running, then there will be a struct perf_event that has a reference to the context, so its refcount will be 2. (The perf_event has been removed from the context's group_entry and event_entry lists by perf_event_exit_cpu(), but that doesn't remove the perf_event's reference to the context and doesn't decrement the context's refcount.) When the cpu comes up, perf_event_init_cpu() gets called, and it calls __perf_event_init_context() on the cpu's context. That resets the refcount to 1. Then when the perf record session finishes and the perf_event is closed, the refcount gets decremented to 0 and the context gets kfreed after an RCU grace period. Since the context wasn't kmalloced -- it's part of a per-cpu variable -- bad things happen. In fact we don't need to completely reinitialize the context when the cpu comes up. It's sufficient to initialize the context once at boot, but we need to do it for all possible cpus. This moves the context initialization to happen at boot time. With this, we don't trash the refcount and the context never gets kfreed, and we don't hit the BUG_ON. Reported-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org> Tested-by: Anton Blanchard <anton@samba.org> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>		2010-03-11 12:43:51 +01:00
..
gcov
irq	sparseirq: Use radix_tree instead of ptrs array	2010-02-17 17:27:20 -08:00
power	mm/pm: force GFP_NOIO during suspend/hibernation and resume	2010-03-06 11:26:26 -08:00
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	perf: Drop the obsolete profile naming for trace events	2010-03-10 14:47:18 +01:00
.gitignore
acct.c	bsdacct: fix uid/gid misreporting	2009-12-15 08:53:10 -08:00
async.c
audit.c
audit.h
audit_tree.c	new helper: iterate_mounts()	2010-03-03 14:07:57 -05:00
audit_watch.c
auditfilter.c
auditsc.c	Lose the first argument of audit_inode_child()	2010-02-08 14:38:36 -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	kernel/cpu.c: delete deprecated definition in cpu_up()	2010-03-06 11:26:28 -08:00
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
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
elfcore.c	elf coredump: add extended numbering support	2010-03-06 11:26:46 -08:00
exec_domain.c
exit.c	kernel/exit.c: fix shadows sparse warning	2010-03-06 11:26:32 -08:00
extable.c
fork.c	kernel core: use helpers for rlimits	2010-03-06 11:26:33 -08:00
freezer.c
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	Merge branch 'perf/core' into perf/urgent	2010-03-04 11:47:52 +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: Jump optimization sysctl interface	2010-02-25 17:49:25 +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	lockdep: Move lock events under lockdep recursion protection	2010-03-10 14:26:07 +01:00
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
Makefile	elf coredump: replace ELF_CORE_EXTRA_* macros by functions	2010-03-06 11:26:45 -08:00
module.c	sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on module dynamic attributes	2010-03-07 17:04:51 -08:00
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: Allocate the cpumask for the padata instance	2010-03-04 13:30:22 +08:00
panic.c	panic: fix panic_timeout accuracy when running on a hypervisor	2010-03-06 11:26:33 -08:00
params.c	sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on dynamic attributes	2010-03-07 17:04:51 -08:00
perf_event.c	perf_event: Fix oops triggered by cpu offline/online	2010-03-11 12:43:51 +01:00
pid.c	kernel/pid.c: update comment on find_task_by_pid_ns	2010-03-06 11:26:33 -08:00
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	kernel core: use helpers for rlimits	2010-03-06 11:26:33 -08:00
posix-timers.c	posix-timers.c: Don't export local functions	2010-02-05 14:54:10 +01:00
printk.c	printk: avoid warning when CONFIG_PRINTK is disabled	2010-03-06 11:26:33 -08:00
profile.c
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	splice: comparing unsigned int < 0	2010-03-06 11:26:32 -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	sysdev: Pass attribute in sysdev_class attributes show/store	2010-03-07 17:04:47 -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	bitops: rename for_each_bit() to for_each_set_bit()	2010-03-06 11:26:23 -08:00
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	kernel core: use helpers for rlimits	2010-03-06 11:26:33 -08:00
sched_stats.h
seccomp.c
semaphore.c
signal.c	kernel core: use helpers for rlimits	2010-03-06 11:26:33 -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	kernel core: use helpers for rlimits	2010-03-06 11:26:33 -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	Merge branch 'perf-probes-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip	2010-03-05 10:50:22 -08:00
sysctl_binary.c	Switch may_open() and break_lease() to passing O_...	2010-03-03 13:00:21 -05:00
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
tsacct.c	mm: clean up mm_counter	2010-03-06 11:26:23 -08:00
uid16.c
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
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