[tip:perf/urgent] perf tools: Fix trigger class trigger_on()

[tip-bot for Adrian Hunter]

Commit-ID:  de19e5c3c51fdb1ff20d0f61d099db902ff7494b
Gitweb: https://git.kernel.org/tip/de19e5c3c51fdb1ff20d0f61d099db902ff7494b
Author: Adrian Hunter 
AuthorDate: Wed, 28 Feb 2018 10:39:04 +0200
Committer:  Arnaldo Carvalho de Melo 
CommitDate: Tue, 6 Mar 2018 11:31:14 -0300

perf tools: Fix trigger class trigger_on()

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 
Acked-by: Jiri Olsa 
Cc: Wang Nan 
Cc: sta...@vger.kernel.org
Fixes: 3dcc4436fa6f ("perf tools: Introduce trigger class")
Link: 
http://lkml.kernel.org/r/1519807144-30694-1-git-send-email-adrian.hun...@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
---
 tools/perf/util/trigger.h | 9 +
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/trigger.h b/tools/perf/util/trigger.h
index 370138e7e35c..88223bc7c82b 100644
--- 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(struct trigger *t)
 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)

[tip:perf/urgent] perf tools: Fix trigger class trigger_on()

[tip-bot for Adrian Hunter]

Commit-ID:  de19e5c3c51fdb1ff20d0f61d099db902ff7494b
Gitweb: https://git.kernel.org/tip/de19e5c3c51fdb1ff20d0f61d099db902ff7494b
Author: Adrian Hunter 
AuthorDate: Wed, 28 Feb 2018 10:39:04 +0200
Committer:  Arnaldo Carvalho de Melo 
CommitDate: Tue, 6 Mar 2018 11:31:14 -0300

perf tools: Fix trigger class trigger_on()

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 
Acked-by: Jiri Olsa 
Cc: Wang Nan 
Cc: sta...@vger.kernel.org
Fixes: 3dcc4436fa6f ("perf tools: Introduce trigger class")
Link: 
http://lkml.kernel.org/r/1519807144-30694-1-git-send-email-adrian.hun...@intel.com
Signed-off-by: Arnaldo Carvalho de Melo 
---
 tools/perf/util/trigger.h | 9 +
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tools/perf/util/trigger.h b/tools/perf/util/trigger.h
index 370138e7e35c..88223bc7c82b 100644
--- 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(struct trigger *t)
 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)