GitHub-Mirror/linux-bl808
2
0
Fork 0
mirror of https://github.com/Fishwaldo/linux-bl808.git synced 2025-06-17 20:25:19 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

lockdep: Fix lockdep recursion

Browse source 
Steve reported that lockdep_assert*irq*(), when nested inside lockdep
itself, will trigger a false-positive.

One example is the stack-trace code, as called from inside lockdep,
triggering tracing, which in turn calls RCU, which then uses
lockdep_assert_irqs_disabled().

Fixes: a21ee6055c ("lockdep: Change hardirq{s_enabled,_context} to per-cpu variables")
Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2020-10-02 11:04:21 +02:00 • committed by Ingo Molnar
parent 2bb8945bcc
commit 4d004099a6
2 changed files with 67 additions and 45 deletions
Download patch file Download diff file Expand all files Collapse all files

13
include/linux/lockdep.h
View file

@ -534,6 +534,7 @@ do { \
DECLARE_PER_CPU(int, hardirqs_enabled);
DECLARE_PER_CPU(int, hardirq_context);
DECLARE_PER_CPU(unsigned int, lockdep_recursion);
/*
* The below lockdep_assert_*() macros use raw_cpu_read() to access the above
@ -543,25 +544,27 @@ DECLARE_PER_CPU(int, hardirq_context);
* read the value from our previous CPU.
*/
#define __lockdep_enabled (debug_locks && !raw_cpu_read(lockdep_recursion))
#define lockdep_assert_irqs_enabled() \
do { \
WARN_ON_ONCE(debug_locks && !raw_cpu_read(hardirqs_enabled)); \
WARN_ON_ONCE(__lockdep_enabled && !raw_cpu_read(hardirqs_enabled)); \
} while (0)
#define lockdep_assert_irqs_disabled() \
do { \
WARN_ON_ONCE(debug_locks && raw_cpu_read(hardirqs_enabled)); \
WARN_ON_ONCE(__lockdep_enabled && raw_cpu_read(hardirqs_enabled)); \
} while (0)
#define lockdep_assert_in_irq() \
do { \
WARN_ON_ONCE(debug_locks && !raw_cpu_read(hardirq_context)); \
WARN_ON_ONCE(__lockdep_enabled && !raw_cpu_read(hardirq_context)); \
} while (0)
#define lockdep_assert_preemption_enabled() \
do { \
WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT) && \
debug_locks && \
__lockdep_enabled && \
(preempt_count() != 0 || \
!raw_cpu_read(hardirqs_enabled))); \
} while (0)
@ -569,7 +572,7 @@ do { \
#define lockdep_assert_preemption_disabled() \
do { \
WARN_ON_ONCE(IS_ENABLED(CONFIG_PREEMPT_COUNT) && \
debug_locks && \
__lockdep_enabled && \
(preempt_count() == 0 && \
raw_cpu_read(hardirqs_enabled))); \
} while (0)