From 57480d2cd93579d665e57e144e1e63f7f02ef058 Mon Sep 17 00:00:00 2001 From: Yann Droneaud Date: Mon, 30 Jun 2014 22:28:47 +0200 Subject: perf tools: Enable close-on-exec flag on perf file descriptor In commit a21b0b354d4a ('perf: Introduce a flag to enable close-on-exec in perf_event_open()'), flag PERF_FLAG_FD_CLOEXEC was added to perf_event_open(2) syscall to allows userspace to atomically enable close-on-exec behavor when creating the file descriptor. This patch makes perf tools use the new flag if supported by the kernel, so that the event file descriptors got automatically closed if perf tool exec a sub-command. Signed-off-by: Yann Droneaud Cc: Andi Kleen Cc: Arnaldo Carvalho de Melo Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Link: http://lkml.kernel.org/n/1404160127-7475-1-git-send-email-ydroneaud@opteya.com Signed-off-by: Jiri Olsa --- tools/perf/util/evsel.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'tools/perf/util/evsel.c') diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 90f58cdd0fb0..21a373ebea22 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -29,6 +29,7 @@ static struct { bool sample_id_all; bool exclude_guest; bool mmap2; + bool cloexec; } perf_missing_features; #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y)) @@ -994,7 +995,7 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus, struct thread_map *threads) { int cpu, thread; - unsigned long flags = 0; + unsigned long flags = PERF_FLAG_FD_CLOEXEC; int pid = -1, err; enum { NO_CHANGE, SET_TO_MAX, INCREASED_MAX } set_rlimit = NO_CHANGE; @@ -1003,11 +1004,13 @@ static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus, return -ENOMEM; if (evsel->cgrp) { - flags = PERF_FLAG_PID_CGROUP; + flags |= PERF_FLAG_PID_CGROUP; pid = evsel->cgrp->fd; } fallback_missing_features: + if (perf_missing_features.cloexec) + flags &= ~(unsigned long)PERF_FLAG_FD_CLOEXEC; if (perf_missing_features.mmap2) evsel->attr.mmap2 = 0; if (perf_missing_features.exclude_guest) @@ -1076,7 +1079,10 @@ try_fallback: if (err != -EINVAL || cpu > 0 || thread > 0) goto out_close; - if (!perf_missing_features.mmap2 && evsel->attr.mmap2) { + if (!perf_missing_features.cloexec && (flags & PERF_FLAG_FD_CLOEXEC)) { + perf_missing_features.cloexec = true; + goto fallback_missing_features; + } else if (!perf_missing_features.mmap2 && evsel->attr.mmap2) { perf_missing_features.mmap2 = true; goto fallback_missing_features; } else if (!perf_missing_features.exclude_guest && -- cgit