From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752045AbaFFMVr (ORCPT ); Fri, 6 Jun 2014 08:21:47 -0400 Received: from terminus.zytor.com ([198.137.202.10]:60939 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751317AbaFFMUd (ORCPT ); Fri, 6 Jun 2014 08:20:33 -0400 Date: Fri, 6 Jun 2014 05:19:27 -0700 From: tip-bot for Adrian Hunter Message-ID: Cc: paulus@samba.org, linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, torvalds@linux-foundation.org, peterz@infradead.org, acme@kernel.org, davej@redhat.com, viro@zeniv.linux.org.uk, jolsa@redhat.com, dsahern@gmail.com, adrian.hunter@intel.com, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, paulus@samba.org, torvalds@linux-foundation.org, peterz@infradead.org, davej@redhat.com, acme@kernel.org, viro@zeniv.linux.org.uk, jolsa@redhat.com, adrian.hunter@intel.com, dsahern@gmail.com, tglx@linutronix.de In-Reply-To: <537D9EBE.7030806@intel.com> References: <537D9EBE.7030806@intel.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf: Differentiate exec() and non-exec() comm events Git-Commit-ID: 82b897782d10fcc4930c9d4a15b175348fdd2871 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 82b897782d10fcc4930c9d4a15b175348fdd2871 Gitweb: http://git.kernel.org/tip/82b897782d10fcc4930c9d4a15b175348fdd2871 Author: Adrian Hunter AuthorDate: Wed, 28 May 2014 11:45:04 +0300 Committer: Ingo Molnar CommitDate: Fri, 6 Jun 2014 07:56:22 +0200 perf: Differentiate exec() and non-exec() comm events perf tools like 'perf report' can aggregate samples by comm strings, which generally works. However, there are other potential use-cases. For example, to pair up 'calls' with 'returns' accurately (from branch events like Intel BTS) it is necessary to identify whether the process has exec'd. Although a comm event is generated when an 'exec' happens it is also generated whenever the comm string is changed on a whim (e.g. by prctl PR_SET_NAME). This patch adds a flag to the comm event to differentiate one case from the other. In order to determine whether the kernel supports the new flag, a selection bit named 'exec' is added to struct perf_event_attr. The bit does nothing but will cause perf_event_open() to fail if the bit is set on kernels that do not have it defined. Signed-off-by: Adrian Hunter Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/537D9EBE.7030806@intel.com Cc: Paul Mackerras Cc: Dave Jones Cc: Arnaldo Carvalho de Melo Cc: David Ahern Cc: Jiri Olsa Cc: Alexander Viro Cc: Linus Torvalds Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar --- fs/exec.c | 6 +++--- include/linux/perf_event.h | 4 ++-- include/linux/sched.h | 6 +++++- include/uapi/linux/perf_event.h | 9 +++++++-- kernel/events/core.c | 4 ++-- 5 files changed, 19 insertions(+), 10 deletions(-) diff --git a/fs/exec.c b/fs/exec.c index a038a41..a3d33fe 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1046,13 +1046,13 @@ EXPORT_SYMBOL_GPL(get_task_comm); * so that a new one can be started */ -void set_task_comm(struct task_struct *tsk, const char *buf) +void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec) { task_lock(tsk); trace_task_rename(tsk, buf); strlcpy(tsk->comm, buf, sizeof(tsk->comm)); task_unlock(tsk); - perf_event_comm(tsk); + perf_event_comm(tsk, exec); } int flush_old_exec(struct linux_binprm * bprm) @@ -1111,7 +1111,7 @@ void setup_new_exec(struct linux_binprm * bprm) set_dumpable(current->mm, suid_dumpable); perf_event_exec(); - set_task_comm(current, kbasename(bprm->filename)); + __set_task_comm(current, kbasename(bprm->filename), true); /* Set the new mm task size. We have to do that late because it may * depend on TIF_32BIT which is only updated in flush_thread() on diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index b4c1d46..707617a 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -707,7 +707,7 @@ extern int perf_register_guest_info_callbacks(struct perf_guest_info_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_comm(struct task_struct *tsk, bool exec); extern void perf_event_fork(struct task_struct *tsk); /* Callchains */ @@ -815,7 +815,7 @@ static inline int perf_unregister_guest_info_callbacks 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_comm(struct task_struct *tsk, bool exec) { } static inline void perf_event_fork(struct task_struct *tsk) { } static inline void perf_event_init(void) { } static inline int perf_swevent_get_recursion_context(void) { return -1; } diff --git a/include/linux/sched.h b/include/linux/sched.h index 221b2bd..ad86e1d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2379,7 +2379,11 @@ extern long do_fork(unsigned long, unsigned long, unsigned long, int __user *, i struct task_struct *fork_idle(int); extern pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); -extern void set_task_comm(struct task_struct *tsk, const char *from); +extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec); +static inline void set_task_comm(struct task_struct *tsk, const char *from) +{ + __set_task_comm(tsk, from, false); +} extern char *get_task_comm(char *to, struct task_struct *tsk); #ifdef CONFIG_SMP diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h index d9cd853..5312fae 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -302,8 +302,8 @@ struct perf_event_attr { exclude_callchain_kernel : 1, /* exclude kernel callchains */ exclude_callchain_user : 1, /* exclude user callchains */ mmap2 : 1, /* include mmap with inode data */ - - __reserved_1 : 40; + comm_exec : 1, /* flag comm events that are due to an exec */ + __reserved_1 : 39; union { __u32 wakeup_events; /* wakeup every n events */ @@ -502,7 +502,12 @@ struct perf_event_mmap_page { #define PERF_RECORD_MISC_GUEST_KERNEL (4 << 0) #define PERF_RECORD_MISC_GUEST_USER (5 << 0) +/* + * PERF_RECORD_MISC_MMAP_DATA and PERF_RECORD_MISC_COMM_EXEC are used on + * different events so can reuse the same bit position. + */ #define PERF_RECORD_MISC_MMAP_DATA (1 << 13) +#define PERF_RECORD_MISC_COMM_EXEC (1 << 13) /* * Indicates that the content of PERF_SAMPLE_IP points to * the actual instruction that triggered the event. See also diff --git a/kernel/events/core.c b/kernel/events/core.c index 8fac205..7da5e56 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -5090,7 +5090,7 @@ static void perf_event_comm_event(struct perf_comm_event *comm_event) NULL); } -void perf_event_comm(struct task_struct *task) +void perf_event_comm(struct task_struct *task, bool exec) { struct perf_comm_event comm_event; @@ -5104,7 +5104,7 @@ void perf_event_comm(struct task_struct *task) .event_id = { .header = { .type = PERF_RECORD_COMM, - .misc = 0, + .misc = exec ? PERF_RECORD_MISC_COMM_EXEC : 0, /* .size */ }, /* .pid */