This is a note to let you know that I've just added the patch titled
perf tools: Fix trigger class trigger_on()
to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
perf-tools-fix-trigger-class-trigger_on.patch
and it can be found in the queue-4.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From de19e5c3c51fdb1ff20d0f61d099db902ff7494b Mon Sep 17 00:00:00 2001
From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Date: Wed, 28 Feb 2018 10:39:04 +0200
Subject: perf tools: Fix trigger class trigger_on()
From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
commit de19e5c3c51fdb1ff20d0f61d099db902ff7494b upstream.
trigger_on() means that the trigger is available but not ready, however
trigger_on() was making it ready. That can segfault if the signal comes
before trigger_ready(). e.g. (USR2 signal delivery not shown)
$ perf record -e intel_pt//u -S sleep 1
perf: Segmentation fault
Obtained 16 stack frames.
/home/ahunter/bin/perf(sighandler_dump_stack+0x40) [0x4ec550]
/lib/x86_64-linux-gnu/libc.so.6(+0x36caf) [0x7fa76411acaf]
/home/ahunter/bin/perf(perf_evsel__disable+0x26) [0x4b9dd6]
/home/ahunter/bin/perf() [0x43a45b]
/lib/x86_64-linux-gnu/libc.so.6(+0x36caf) [0x7fa76411acaf]
/lib/x86_64-linux-gnu/libc.so.6(__xstat64+0x15) [0x7fa7641d2cc5]
/home/ahunter/bin/perf() [0x4ec6c9]
/home/ahunter/bin/perf() [0x4ec73b]
/home/ahunter/bin/perf() [0x4ec73b]
/home/ahunter/bin/perf() [0x4ec73b]
/home/ahunter/bin/perf() [0x4eca15]
/home/ahunter/bin/perf(machine__create_kernel_maps+0x257) [0x4f0b77]
/home/ahunter/bin/perf(perf_session__new+0xc0) [0x4f86f0]
/home/ahunter/bin/perf(cmd_record+0x722) [0x43c132]
/home/ahunter/bin/perf() [0x4a11ae]
/home/ahunter/bin/perf(main+0x5d4) [0x427fb4]
Note, for testing purposes, this is hard to hit unless you add some sleep()
in builtin-record.c before record__open().
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 3dcc4436fa6f ("perf tools: Introduce trigger class")
Link: http://lkml.kernel.org/r/1519807144-30694-1-git-send-email-adrian.hunter@xxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/perf/util/trigger.h | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
--- a/tools/perf/util/trigger.h
+++ b/tools/perf/util/trigger.h
@@ -12,7 +12,7 @@
* States and transits:
*
*
- * OFF--(on)--> READY --(hit)--> HIT
+ * OFF--> ON --> READY --(hit)--> HIT
* ^ |
* | (ready)
* | |
@@ -27,8 +27,9 @@ struct trigger {
volatile enum {
TRIGGER_ERROR = -2,
TRIGGER_OFF = -1,
- TRIGGER_READY = 0,
- TRIGGER_HIT = 1,
+ TRIGGER_ON = 0,
+ TRIGGER_READY = 1,
+ TRIGGER_HIT = 2,
} state;
const char *name;
};
@@ -50,7 +51,7 @@ static inline bool trigger_is_error(stru
static inline void trigger_on(struct trigger *t)
{
TRIGGER_WARN_ONCE(t, TRIGGER_OFF);
- t->state = TRIGGER_READY;
+ t->state = TRIGGER_ON;
}
static inline void trigger_ready(struct trigger *t)
Patches currently in stable-queue which might be from adrian.hunter@xxxxxxxxx are
queue-4.15/perf-tools-fix-trigger-class-trigger_on.patch