Steven Rostedt (Red Hat) f1bb130708 tracing: Have branch tracer use recursive field of task struct ... commit 6224beb12e190ff11f3c7d4bf50cb2922878f600 upstream. Fengguang Wu's tests triggered a bug in the branch tracer's start up test when CONFIG_DEBUG_PREEMPT set. This was because that config adds some debug logic in the per cpu field, which calls back into the branch tracer. The branch tracer has its own recursive checks, but uses a per cpu variable to implement it. If retrieving the per cpu variable calls back into the branch tracer, you can see how things will break. Instead of using a per cpu variable, use the trace_recursion field of the current task struct. Simply set a bit when entering the branch tracing and clear it when leaving. If the bit is set on entry, just don't do the tracing. There's also the case with lockdep, as the local_irq_save() called before the recursion can also trigger code that can call back into the function. Changing that to a raw_local_irq_save() will protect that as well. This prevents the recursion and the inevitable crash that follows. Link: http://lkml.kernel.org/r/20150630141803.GA28071@wfg-t540p.sh.intel.com Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2015-08-03 09:29:45 -07:00
..
cpu	sched, idle: Fix the idle polling state logic	2013-11-29 11:11:42 -08:00
debug	kdb: fix incorrect counts in KDB summary command output	2015-03-06 14:40:52 -08:00
events	perf: Fix irq_work 'tail' recursion	2015-04-13 14:02:12 +02:00
gcov	…
irq	genirq: Sanitize spurious interrupt detection of threaded irqs	2014-06-30 20:09:45 -07:00
power	PM / QoS: remove duplicate call to pm_qos_update_target	2015-03-18 13:22:28 +01:00
sched	printk: rename printk_sched to printk_deferred	2014-08-07 14:30:26 -07:00
time	ntp: Fixup adjtimex freq validation on 32-bit systems	2015-03-06 14:40:52 -08:00
trace	tracing: Have branch tracer use recursive field of task struct	2015-08-03 09:29:45 -07:00
.gitignore	kernel/hz.bc: ignore.	2013-04-22 07:09:06 -07:00
Kconfig.freezer	…
Kconfig.hz	…
Kconfig.locks	locking/mutex: Disable optimistic spinning on some architectures	2014-07-28 08:00:07 -07:00
Kconfig.preempt	…
Makefile	We get rid of the general module prefix confusion with a binary config option,	2013-05-05 10:58:06 -07:00
acct.c	fs: Fix hang with BSD accounting on frozen filesystem	2013-05-04 14:57:58 -04:00
async.c	…
audit.c	CAPABILITIES: remove undefined caps from all processes	2014-09-17 09:03:57 -07:00
audit.h	audit: fix mq_open and mq_unlink to add the MQ root as a hidden parent audit_names record	2013-12-04 10:57:03 -08:00
audit_tree.c	audit: keep inode pinned	2014-11-21 09:22:52 -08:00
audit_watch.c	…
auditfilter.c	auditfilter.c: fix kernel-doc warnings	2013-05-24 16:22:52 -07:00
auditsc.c	auditsc: audit_krule mask accesses need bounds checking	2014-06-16 13:42:53 -07:00
backtracetest.c	…
bounds.c	…
capability.c	CAPABILITIES: remove undefined caps from all processes	2014-09-17 09:03:57 -07:00
cgroup.c	move d_rcu from overlapping d_child to overlapping d_alias	2015-04-29 10:34:00 +02:00
cgroup_freezer.c	…
compat.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal	2013-05-01 07:21:43 -07:00
configs.c	proc: Supply PDE attribute setting accessor functions	2013-05-01 17:29:18 -04:00
context_tracking.c	Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2013-06-20 08:18:35 -10:00
cpu.c	sched: Fix hotplug vs. set_cpus_allowed_ptr()	2014-06-11 12:03:24 -07:00
cpu_pm.c	…
cpuset.c	cpuset,mempolicy: fix sleeping function called from invalid context	2014-07-17 15:58:00 -07:00
crash_dump.c	…
cred.c	…
delayacct.c	…
dma.c	…
elfcore.c	…
exec_domain.c	…
exit.c	introduce for_each_thread() to replace the buggy while_each_thread()	2014-10-05 14:54:15 -07:00
extable.c	extable: Flip the sorting message	2013-04-15 13:25:16 +02:00
fork.c	perf: fix perf bug in fork()	2014-10-09 12:18:42 -07:00
freezer.c	freezer: Do not freeze tasks killed by OOM killer	2014-11-14 08:47:58 -08:00
futex.c	futex: Make lookup_pi_state more robust	2014-06-07 13:25:41 -07:00
futex_compat.c	…
groups.c	userns: Don't allow setgroups until a gid mapping has been setablished	2015-01-08 09:58:16 -08:00
hrtimer.c	hrtimer: Set expiry time before switch_hrtimer_base()	2014-06-07 13:25:31 -07:00
hung_task.c	…
irq_work.c	…
itimer.c	…
jump_label.c	…
kallsyms.c	kernel: kallsyms: memory override issue, need check destination buffer length	2013-04-15 15:17:26 +09:30
kcmp.c	kcmp: fix standard comparison bug	2014-10-05 14:54:13 -07:00
kexec.c	PCI: Disable Bus Master only on kexec reboot	2013-12-20 07:45:08 -08:00
kmod.c	usermodehelper: check subprocess_info->path != NULL	2013-05-16 12:01:11 -07:00
kprobes.c	kprobes: Fix to free gone and unused optprobes	2013-05-28 10:37:59 +02:00
ksysfs.c	…
kthread.c	kthread: implement probe_kthread_data()	2013-04-30 17:04:02 -07:00
latencytop.c	…
lglock.c	…
lockdep.c	Merge branch 'for-3.10/drivers' of git://git.kernel.dk/linux-block	2013-05-08 11:51:05 -07:00
lockdep_internals.h	…
lockdep_proc.c	…
lockdep_states.h	…
modsign_certificate.S	CONFIG_SYMBOL_PREFIX: cleanup.	2013-03-15 15:09:43 +10:30
modsign_pubkey.c	…
module-internal.h	…
module.c	modules, lock around setting of MODULE_STATE_UNFORMED	2014-11-14 08:47:55 -08:00
module_signing.c	…
mutex-debug.c	…
mutex-debug.h	…
mutex.c	mutex: Back out architecture specific check for negative mutex count	2013-04-19 09:33:36 +02:00
mutex.h	…
notifier.c	…
nsproxy.c	proc: Split the namespace stuff out into linux/proc_ns.h	2013-05-01 17:29:39 -04:00
padata.c	…
panic.c	dump_stack: implement arch-specific hardware description in task dumps	2013-04-30 17:04:02 -07:00
params.c	params: Fix potential memory leak in add_sysfs_param()	2013-03-18 11:40:21 +00:00
pid.c	exit: pidns: alloc_pid() leaks pid_namespace if child_reaper is exiting	2015-01-08 09:58:17 -08:00
pid_namespace.c	pid_namespace: pidns_get() should check task_active_pid_ns() != NULL	2014-04-26 17:15:34 -07:00
posix-cpu-timers.c	posix_timers: Fix pre-condition to stop the tick on full dynticks	2013-04-22 19:59:25 +02:00
posix-timers.c	posix-timers: Fix stack info leak in timer_create()	2014-11-14 08:48:00 -08:00
printk.c	console: Fix console name size mismatch	2015-04-19 10:10:51 +02:00
profile.c	proc: Supply PDE attribute setting accessor functions	2013-05-01 17:29:18 -04:00
ptrace.c	__ptrace_may_access() should not deny sub-threads	2015-07-03 19:48:08 -07:00
range.c	range: Do not add new blank slot with add_range_with_merge	2013-06-18 11:32:10 -05:00
rcu.h	…
rcupdate.c	…
rcutiny.c	…
rcutiny_plugin.h	…
rcutorture.c	…
rcutree.c	rcu: Fix deadlock with CPU hotplug, RCU GP init, and timer migration	2013-06-10 13:37:12 -07:00
rcutree.h	rcu: Don't call wakeup() with rcu_node structure ->lock held	2013-06-10 13:37:11 -07:00
rcutree_plugin.h	rcu: Don't allocate bootmem from rcu_init()	2013-05-15 10:41:12 -07:00
rcutree_trace.c	rcutrace: single_open() leaks	2013-05-05 00:16:35 -04:00
relay.c	Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-block	2013-05-08 10:13:35 -07:00
res_counter.c	…
resource.c	mem hotunplug: fix kfree() of bootmem memory	2013-04-29 15:54:40 -07:00
rtmutex-debug.c	…
rtmutex-debug.h	rtmutex: Handle deadlock detection smarter	2014-07-17 15:58:04 -07:00
rtmutex-tester.c	locking/rtmutex/tester: Set correct permissions on sysfs files	2013-04-10 14:48:37 +02:00
rtmutex.c	rtmutex: Plug slow unlock race	2014-07-17 15:58:04 -07:00
rtmutex.h	rtmutex: Handle deadlock detection smarter	2014-07-17 15:58:04 -07:00
rtmutex_common.h	…
rwsem.c	Revert "rw_semaphore: remove up/down_read_non_owner"	2013-03-23 15:53:52 -07:00
seccomp.c	seccomp: allow BPF_XOR based ALU instructions.	2013-03-26 11:07:19 +11:00
semaphore.c	semaphore: use `bool' type for semaphore_waiter's up	2013-04-30 17:04:08 -07:00
signal.c	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next	2013-05-01 14:08:52 -07:00
smp.c	kernel/smp.c:on_each_cpu_cond(): fix warning in fallback path	2014-09-17 09:03:57 -07:00
smpboot.c	smpboot: Add missing get_online_cpus() in smpboot_register_percpu_thread()	2015-02-11 14:48:17 +08:00
smpboot.h	…
softirq.c	revert "softirq: Add support for triggering softirq work on softirqs"	2015-05-17 09:51:33 -07:00
spinlock.c	…
srcu.c	…
stacktrace.c	…
stop_machine.c	…
sys.c	reboot: rigrate shutdown/reboot to boot cpu	2013-06-12 16:29:44 -07:00
sys_ni.c	unify compat fanotify_mark(2), switch to COMPAT_SYSCALL_DEFINE	2013-05-09 13:46:38 -04:00
sysctl.c	perf: Enforce 1 as lower limit for perf_event_max_sample_rate	2014-06-11 12:03:27 -07:00
sysctl_binary.c	switch compat_sys_sysctl to COMPAT_SYSCALL_DEFINE	2013-05-09 14:53:20 -04:00
task_work.c	…
taskstats.c	…
test_kprobes.c	kernel/: rename random32() to prandom_u32()	2013-04-29 18:28:42 -07:00
time.c	time: settimeofday: Validate the values of tv from user	2015-01-29 17:40:56 -08:00
timeconst.bc	…
timer.c	timer: Prevent overflow in apply_slack	2014-06-07 13:25:30 -07:00
tracepoint.c	tracepoint: Do not waste memory on mods with no tracepoints	2014-05-30 21:52:11 -07:00
tsacct.c	…
uid16.c	groups: Consolidate the setgroups permission checks	2015-01-08 09:58:16 -08:00
up.c	…
user-return-notifier.c	…
user.c	userns: Add a knob to disable setgroups on a per user namespace basis	2015-01-08 09:58:16 -08:00
user_namespace.c	userns: Allow setting gid_maps without privilege when setgroups is disabled	2015-01-08 09:58:17 -08:00
utsname.c	proc: Split the namespace stuff out into linux/proc_ns.h	2013-05-01 17:29:39 -04:00
utsname_sysctl.c	…
wait.c	…
watchdog.c	watchdog: Add comments to explain the watchdog_disabled variable	2013-03-14 08:24:05 +01:00
workqueue.c	workqueue: fix hang involving racing cancel[_delayed]_work_sync()'s for PREEMPT_NONE	2015-03-26 15:00:58 +01:00
workqueue_internal.h	workqueue: include workqueue info when printing debug dump of a worker task	2013-04-30 17:04:02 -07:00