* [PATCH 4.19 09/41] tracepoint: Use __idx instead of idx in DO_TRACE macro to make it unique
[not found] <20181206142949.757402551@linuxfoundation.org>
@ 2018-12-06 14:38 ` Greg Kroah-Hartman
0 siblings, 0 replies; only message in thread
From: Greg Kroah-Hartman @ 2018-12-06 14:38 UTC (permalink / raw)
To: linux-kernel
Cc: Greg Kroah-Hartman, stable, Joel Fernandes, Wang Haibin,
linux-trace-devel, Zenghui Yu, Steven Rostedt (VMware)
4.19-stable review patch. If anyone has any objections, please let me know.
------------------
From: Zenghui Yu <yuzenghui@huawei.com>
commit 0c7a52e4d4b5c4d35b31f3c3ad32af814f1bf491 upstream.
After enabling KVM event tracing, almost all of trace_kvm_exit()'s
printk shows
"kvm_exit: IRQ: ..."
even if the actual exception_type is NOT IRQ. More specifically,
trace_kvm_exit() is defined in virt/kvm/arm/trace.h by TRACE_EVENT.
This slight problem may have existed after commit e6753f23d961
("tracepoint: Make rcuidle tracepoint callers use SRCU"). There are
two variables in trace_kvm_exit() and __DO_TRACE() which have the
same name, *idx*. Thus the actual value of *idx* will be overwritten
when tracing. Fix it by adding a simple prefix.
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Wang Haibin <wanghaibin.wang@huawei.com>
Cc: linux-trace-devel@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: e6753f23d961 ("tracepoint: Make rcuidle tracepoint callers use SRCU")
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
include/linux/tracepoint.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -166,7 +166,7 @@ static inline struct tracepoint *tracepo
struct tracepoint_func *it_func_ptr; \
void *it_func; \
void *__data; \
- int __maybe_unused idx = 0; \
+ int __maybe_unused __idx = 0; \
\
if (!(cond)) \
return; \
@@ -182,7 +182,7 @@ static inline struct tracepoint *tracepo
* doesn't work from the idle path. \
*/ \
if (rcuidle) { \
- idx = srcu_read_lock_notrace(&tracepoint_srcu); \
+ __idx = srcu_read_lock_notrace(&tracepoint_srcu);\
rcu_irq_enter_irqson(); \
} \
\
@@ -198,7 +198,7 @@ static inline struct tracepoint *tracepo
\
if (rcuidle) { \
rcu_irq_exit_irqson(); \
- srcu_read_unlock_notrace(&tracepoint_srcu, idx);\
+ srcu_read_unlock_notrace(&tracepoint_srcu, __idx);\
} \
\
preempt_enable_notrace(); \
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