Commit-ID: e041e328c4b41e1db79bfe5ba9992c2ed771ad19 Gitweb: http://git.kernel.org/tip/e041e328c4b41e1db79bfe5ba9992c2ed771ad19 Author: Peter Zijlstra <pet...@infradead.org> AuthorDate: Wed, 21 May 2014 17:32:19 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Fri, 6 Jun 2014 07:54:02 +0200
perf: Fix perf_event_comm() vs. exec() assumption perf_event_comm() assumes that set_task_comm() is only called on exec(), and in particular that its only called on current. Neither are true, as Dave reported a WARN triggered by set_task_comm() being called on !current. Separate the exec() hook from the comm hook. Reported-by: Dave Jones <da...@redhat.com> Signed-off-by: Peter Zijlstra <pet...@infradead.org> Cc: Alexander Viro <v...@zeniv.linux.org.uk> Cc: Arnaldo Carvalho de Melo <a...@kernel.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: linux-fsde...@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20140521153219.gh5...@laptop.programming.kicks-ass.net [ Build fix. ] Signed-off-by: Ingo Molnar <mi...@kernel.org> --- fs/exec.c | 1 + include/linux/perf_event.h | 4 +++- kernel/events/core.c | 28 ++++++++++++++++------------ 3 files changed, 20 insertions(+), 13 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index 238b7aa..a038a41 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1110,6 +1110,7 @@ void setup_new_exec(struct linux_binprm * bprm) else set_dumpable(current->mm, suid_dumpable); + perf_event_exec(); set_task_comm(current, kbasename(bprm->filename)); /* Set the new mm task size. We have to do that late because it may diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 3ef6ea1..9b5cd19 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -695,6 +695,7 @@ extern struct perf_guest_info_callbacks *perf_guest_cbs; extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); extern int perf_unregister_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks); +extern void perf_event_exec(void); extern void perf_event_comm(struct task_struct *tsk); extern void perf_event_fork(struct task_struct *tsk); @@ -772,7 +773,7 @@ extern void perf_event_enable(struct perf_event *event); extern void perf_event_disable(struct perf_event *event); extern int __perf_event_disable(void *info); extern void perf_event_task_tick(void); -#else +#else /* !CONFIG_PERF_EVENTS: */ static inline void perf_event_task_sched_in(struct task_struct *prev, struct task_struct *task) { } @@ -802,6 +803,7 @@ static inline int perf_unregister_guest_info_callbacks (struct perf_guest_info_callbacks *callbacks) { return 0; } static inline void perf_event_mmap(struct vm_area_struct *vma) { } +static inline void perf_event_exec(void) { } static inline void perf_event_comm(struct task_struct *tsk) { } static inline void perf_event_fork(struct task_struct *tsk) { } static inline void perf_event_init(void) { } diff --git a/kernel/events/core.c b/kernel/events/core.c index 440eefc..647698f 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2970,6 +2970,22 @@ out: local_irq_restore(flags); } +void perf_event_exec(void) +{ + struct perf_event_context *ctx; + int ctxn; + + rcu_read_lock(); + for_each_task_context_nr(ctxn) { + ctx = current->perf_event_ctxp[ctxn]; + if (!ctx) + continue; + + perf_event_enable_on_exec(ctx); + } + rcu_read_unlock(); +} + /* * Cross CPU call to read the hardware event */ @@ -5057,18 +5073,6 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event) void perf_event_comm(struct task_struct *task) { struct perf_comm_event comm_event; - struct perf_event_context *ctx; - int ctxn; - - rcu_read_lock(); - for_each_task_context_nr(ctxn) { - ctx = task->perf_event_ctxp[ctxn]; - if (!ctx) - continue; - - perf_event_enable_on_exec(ctx); - } - rcu_read_unlock(); if (!atomic_read(&nr_comm_events)) return; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
