Steven Rostedt (Red Hat) 6224beb12e tracing: Have branch tracer use recursive field of task struct ... 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 Cc: stable@vger.kernel.org # 3.10+ Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>		2015-07-08 11:53:45 -04:00
..
bpf	bpf: allow networking programs to use bpf_trace_printk() for debugging	2015-06-15 15:53:50 -07:00
configs	kconfig: add xenconfig defconfig helper	2015-06-16 11:04:29 +01:00
debug	debug: prevent entering debug mode on panic/exception.	2015-02-19 12:39:03 -06:00
events	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-07-04 19:36:06 -07:00
gcov	gcov: add support for GCC 5.1	2015-06-30 19:44:57 -07:00
irq	Merge branch 'irq/for-x86' into irq/core	2015-06-20 19:14:31 +02:00
livepatch	Merge branches 'for-4.1/upstream-fixes', 'for-4.2/kaslr' and 'for-4.2/upstream' into for-linus	2015-06-22 16:26:56 +02:00
locking	Merge branch 'sched-hrtimers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-06-24 15:09:40 -07:00
power	Power management and ACPI fixes for v4.2-rc1	2015-07-01 14:17:44 -07:00
printk	printk: improve the description of /dev/kmsg line format	2015-06-30 19:44:59 -07:00
rcu	This patch series contains several clean ups and even a new trace clock	2015-06-26 14:02:43 -07:00
sched	Except for the preempt notifiers fix, these are all small bugfixes	2015-07-04 11:29:59 -07:00
time	Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-07-01 15:44:18 -07:00
trace	tracing: Have branch tracer use recursive field of task struct	2015-07-08 11:53:45 -04:00
.gitignore
acct.c	acct: check FMODE_CAN_WRITE	2015-04-11 22:27:55 -04:00
async.c
audit_tree.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs	2015-04-26 17:22:07 -07:00
audit_watch.c	VFS: audit: d_backing_inode() annotations	2015-04-15 15:06:55 -04:00
audit.c	Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit	2015-06-27 13:53:16 -07:00
audit.h	Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit	2015-04-22 14:49:23 -07:00
auditfilter.c	Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit	2015-02-11 20:07:47 -08:00
auditsc.c	Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit	2015-06-27 13:53:16 -07:00
backtracetest.c
bounds.c
capability.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
cgroup_freezer.c
cgroup.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2015-07-03 15:20:57 -07:00
compat.c	compat: cleanup coding in compat_get_bitmap() and compat_put_bitmap()	2015-06-04 23:57:18 +02:00
configs.c
context_tracking.c	context_tracking: Inherit TIF_NOHZ through forks instead of context switches	2015-05-07 12:02:51 +02:00
cpu_pm.c
cpu.c	cpu: Remove new instance of __cpuinit that crept back in	2015-05-27 12:58:39 -07:00
cpuset.c	kernel, cpuset: remove exception for __GFP_THISNODE	2015-04-14 16:49:03 -07:00
crash_dump.c
cred.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
delayacct.c
dma.c
elfcore.c
exec_domain.c	Remove rest of exec domains.	2015-04-12 21:03:31 +02:00
exit.c	exit,stats: /* obey this comment */	2015-06-25 17:00:43 -07:00
extable.c
fork.c	Merge branch 'for-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup	2015-06-26 19:50:04 -07:00
freezer.c
futex_compat.c
futex.c	Merge branch 'sched-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-06-24 14:46:01 -07:00
groups.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
hung_task.c	kernel/hung_task.c: change hung_task.c to use for_each_process_thread()	2015-04-15 16:35:22 -07:00
irq_work.c
jump_label.c	module, jump_label: Fix module locking	2015-05-27 11:09:50 +09:30
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks	locking/qrwlock: Rename QUEUE_RWLOCK to QUEUED_RWLOCKS	2015-05-12 09:46:00 +02:00
Kconfig.preempt
kexec.c	kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path	2015-06-30 19:44:57 -07:00
kmod.c
kprobes.c	kprobes: makes kprobes/enabled works correctly for optimized kprobes.	2015-02-13 21:21:42 -08:00
ksysfs.c
kthread.c
latencytop.c
Makefile	make certificate list change message more useful	2015-07-02 16:42:13 -07:00
module_signing.c
module-internal.h
module.c	Minor merge needed, due to function move.	2015-07-01 10:49:25 -07:00
notifier.c	rcu: Make SRCU optional by using CONFIG_SRCU	2015-01-06 11:04:29 -08:00
nsproxy.c
padata.c	padata: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
panic.c	kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path	2015-06-30 19:44:57 -07:00
params.c	Minor merge needed, due to function move.	2015-07-01 10:49:25 -07:00
pid_namespace.c
pid.c	fork: report pid reservation failure properly	2015-04-17 09:04:06 -04:00
profile.c	profile: use %*pb[l] to print bitmaps including cpumasks and nodemasks	2015-02-13 21:21:38 -08:00
ptrace.c	ptrace: ptrace_detach() can no longer race with SIGKILL	2015-04-17 09:04:06 -04:00
range.c	kernel: avoid overflow in cmp_range	2015-01-17 10:02:23 +13:00
reboot.c	kernel/reboot.c: add orderly_reboot for graceful reboot	2015-04-15 16:35:23 -07:00
relay.c	kernel/relay.c: use kvfree() in relay_free_page_array()	2015-06-30 19:44:59 -07:00
resource.c	kernel/resource.c: remove deprecated __check_region() and friends	2015-04-15 16:35:22 -07:00
seccomp.c	seccomp, filter: add and use bpf_prog_create_from_user from seccomp	2015-05-09 17:35:05 -04:00
signal.c	Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2015-06-27 13:26:03 -07:00
smp.c	smp: Fix error case handling in smp_call_function_*()	2015-04-19 13:19:23 -07:00
smpboot.c	watchdog: add watchdog_cpumask sysctl to assist nohz	2015-06-24 17:49:40 -07:00
smpboot.h
softirq.c	Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip	2015-02-09 15:24:03 -08:00
stacktrace.c
stop_machine.c	sched/stop_machine: Fix deadlock between multiple stop_two_cpus()	2015-06-19 10:03:12 +02:00
sys_ni.c	kernel: conditionally support non-root users, groups and capabilities	2015-04-15 16:35:22 -07:00
sys.c	prctl: more prctl(PR_SET_MM_*) checks	2015-06-25 17:00:37 -07:00
sysctl_binary.c
sysctl.c	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace	2015-07-03 15:20:57 -07:00
system_certificates.S
system_keyring.c
task_work.c
taskstats.c	netlink: make nlmsg_end() and genlmsg_end() void	2015-01-18 01:03:45 -05:00
test_kprobes.c
torture.c	rcu: Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE()	2015-05-27 12:56:15 -07:00
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog.c	watchdog: add watchdog_cpumask sysctl to assist nohz	2015-06-24 17:49:40 -07:00
workqueue_internal.h
workqueue.c	Minor merge needed, due to function move.	2015-07-01 10:49:25 -07:00