linux-stable/kernel
Steven Rostedt (Red Hat) a2d7629048 tracing: Have stack tracer force RCU to be watching
The stack tracer was triggering the WARN_ON() in module.c:

 static void module_assert_mutex_or_preempt(void)
 {
 #ifdef CONFIG_LOCKDEP
	if (unlikely(!debug_locks))
		return;

	WARN_ON(!rcu_read_lock_sched_held() &&
		!lockdep_is_held(&module_mutex));
 #endif
 }

The reason is that the stack tracer traces all function calls, and some of
those calls happen while exiting or entering user space and idle. Some of
these functions are called after RCU had already stopped watching, as RCU
does not watch userspace or idle CPUs.

If a max stack is hit, then the save_stack_trace() is called, which will
check module addresses and call module_assert_mutex_or_preempt(), and then
trigger the warning. Sad part is, the warning itself will also do a stack
trace and tigger the same warning. That probably should be fixed.

The warning was added by 0be964be0d "module: Sanitize RCU usage and
locking" but this bug has probably been around longer. But it's unlikely to
cause much harm, but the new warning causes the system to lock up.

Cc: stable@vger.kernel.org # 4.2+
Cc: Peter Zijlstra <peterz@infradead.org>
Cc:"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-10-20 11:38:08 -04:00
..
bpf bpf: fix out of bounds access in verifier log 2015-09-09 14:11:55 -07:00
configs kconfig: add xenconfig defconfig helper 2015-06-16 11:04:29 +01:00
debug
events perf: Fix races in computing the header sizes 2015-09-18 09:20:26 +02:00
gcov gcov: add support for GCC 5.1 2015-06-30 19:44:57 -07:00
irq genirq/msi: Do not use pci_msi_[un]mask_irq as default methods 2015-10-16 12:40:43 +02:00
livepatch livepatch: Improve error handling in klp_disable_func() 2015-07-14 22:48:06 +02:00
locking locking/lockdep: Fix hlock->pin_count reset on lock stack rebuilds 2015-09-23 09:48:53 +02:00
power Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-block 2015-09-02 13:10:25 -07:00
printk kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
rcu rcu: Suppress lockdep false positive for rcp->exp_funnel_mutex 2015-09-20 21:01:22 -07:00
sched sched/core: Fix TASK_DEAD race in finish_task_switch() 2015-10-06 17:05:17 +02:00
time timekeeping: Increment clock_was_set_seq in timekeeping_init() 2015-10-16 15:50:22 +02:00
trace tracing: Have stack tracer force RCU to be watching 2015-10-20 11:38:08 -04:00
.gitignore
acct.c
async.c
audit.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-09-08 13:34:59 -07:00
audit.h Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-09-08 13:34:59 -07:00
audit_fsnotify.c audit: clean simple fsnotify implementation 2015-08-06 16:14:53 -04:00
audit_tree.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-09-08 13:34:59 -07:00
audit_watch.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-09-08 13:34:59 -07:00
auditfilter.c audit: implement audit by executable 2015-08-06 16:17:25 -04:00
auditsc.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-09-08 13:34:59 -07:00
backtracetest.c
bounds.c
capability.c
cgroup.c Revert "sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem" 2015-09-16 11:51:12 -04:00
cgroup_freezer.c cgroup: allow a cgroup subsystem to reject a fork 2015-07-14 17:29:23 -04:00
cgroup_pids.c cgroup: pids: fix invalid get/put usage 2015-08-25 14:19:25 -04:00
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
cpu.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-08-31 20:26:22 -07:00
cpu_pm.c kernel/cpu_pm: fix cpu_cluster_pm_exit comment 2015-09-03 02:42:20 +02:00
cpuset.c cpuset: use trialcs->mems_allowed as a temp variable 2015-08-10 11:18:41 -04:00
crash_dump.c
cred.c kernel/cred.c: remove unnecessary kdebug atomic reads 2015-09-10 13:29:01 -07:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c kernel: exit: fix typo in comment 2015-08-07 13:59:49 +02:00
extable.c kernel/extable.c: remove duplicated include 2015-09-10 13:29:01 -07:00
fork.c Revert "sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem" 2015-09-16 11:51:12 -04:00
freezer.c
futex.c futex: Make should_fail_futex() static 2015-07-20 21:43:54 +02:00
futex_compat.c
groups.c
hung_task.c
irq_work.c
jump_label.c locking/static_keys: Add selftest 2015-08-03 11:34:16 +02:00
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
kexec_core.c kexec: export KERNEL_IMAGE_SIZE to vmcoreinfo 2015-09-10 13:29:01 -07:00
kexec_file.c kexec: split kexec_file syscall code to kexec_file.c 2015-09-10 13:29:01 -07:00
kexec_internal.h kexec: split kexec_file syscall code to kexec_file.c 2015-09-10 13:29:01 -07:00
kmod.c kmod: handle UMH_WAIT_PROC from system unbound workqueue 2015-09-10 13:29:01 -07:00
kprobes.c perf/x86/hw_breakpoints: Disallow kernel breakpoints unless kprobe-safe 2015-08-04 10:16:54 +02:00
ksysfs.c kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
kthread.c kernel/kthread.c:kthread_create_on_node(): clarify documentation 2015-09-04 16:54:41 -07:00
latencytop.c
Makefile sys_membarrier(): system-wide memory barrier (generic, x86) 2015-09-11 15:21:34 -07:00
membarrier.c sys_membarrier(): system-wide memory barrier (generic, x86) 2015-09-11 15:21:34 -07:00
memremap.c add devm_memremap_pages 2015-08-27 19:40:58 -04:00
module-internal.h
module.c module: weaken locking assertion for oops path. 2015-07-29 06:13:22 +09:30
module_signing.c PKCS#7: Appropriately restrict authenticated attributes and content type 2015-08-12 17:01:01 +01:00
notifier.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-09-01 08:40:25 -07:00
nsproxy.c
padata.c
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.c rcu: Rename rcu_lockdep_assert() to RCU_LOCKDEP_WARN() 2015-07-22 15:27:32 -07:00
pid_namespace.c
profile.c mm: rename alloc_pages_exact_node() to __alloc_pages_node() 2015-09-08 15:35:28 -07:00
ptrace.c seccomp: add ptrace options for suspend/resume 2015-07-15 11:52:52 -07:00
range.c
reboot.c kexec: split kexec_load syscall from kexec core code 2015-09-10 13:29:01 -07:00
relay.c kernel/relay.c: use kvfree() in relay_free_page_array() 2015-06-30 19:44:59 -07:00
resource.c mm: enhance region_is_ram() to region_intersects() 2015-08-10 23:07:05 -04:00
seccomp.c Merge tag 'seccomp-next' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux into next 2015-07-20 17:19:19 +10:00
signal.c signal: fix information leak in copy_siginfo_to_user 2015-08-07 04:39:40 +03:00
smp.c
smpboot.c smpboot: allow passing the cpumask on per-cpu thread registration 2015-09-04 16:54:41 -07:00
smpboot.h
softirq.c
stacktrace.c
stop_machine.c stop_machine: Remove cpu_stop_work's from list in cpu_stop_park() 2015-08-03 12:21:28 +02:00
sys.c vfs: Commit to never having exectuables on proc and sysfs. 2015-07-10 10:39:25 -05:00
sys_ni.c sys_membarrier(): system-wide memory barrier (generic, x86) 2015-09-11 15:21:34 -07:00
sysctl.c sysctl: fix int -> unsigned long assignments in INT_MIN case 2015-09-10 13:29:01 -07:00
sysctl_binary.c
task_work.c task_work: remove fifo ordering guarantee 2015-09-05 13:46:58 -07:00
taskstats.c
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-return-notifier.c
user.c
user_namespace.c capabilities: ambient capabilities 2015-09-04 16:54:41 -07:00
utsname.c
utsname_sysctl.c
watchdog.c watchdog: rename watchdog_suspend() and watchdog_resume() 2015-09-04 16:54:41 -07:00
workqueue.c workqueue: make sure delayed work run in local cpu 2015-09-30 13:06:46 -04:00
workqueue_internal.h