When debug preempt or preempt tracer is enabled, preempt_count_add/sub()
can be traced by function and function graph tracing, and
preempt_disable/enable() would call preempt_count_add/sub(), so
we should use preempt_disable/enable_notrace in Ftrace subsystem.
The function this_cpu_read() started being used by function graph tracing
after the commit 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the
bitmap like events do"), so it has to use preempt_disable/enable_notrace
instead now.
Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
---
include/asm-generic/percpu.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h
index 4d9f233..70fefec 100644
--- a/include/asm-generic/percpu.h
+++ b/include/asm-generic/percpu.h
@@ -108,9 +108,9 @@ do { \
#define this_cpu_generic_read(pcp) \
({ \
typeof(pcp) __ret; \
- preempt_disable(); \
+ preempt_disable_notrace(); \
__ret = *this_cpu_ptr(&(pcp)); \
- preempt_enable(); \
+ preempt_enable_notrace(); \
__ret; \
})
--
2.7.4
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