Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

User visible changes:

  - Warn if given uprobe event accesses memory on older kernel (Masami Hiramatsu)

  - 'perf record' Documentation fixes (Namhyung Kim)

  - Report unsupported events properly in 'perf stat' (Suzuki K. Poulose)

Infrastructure changes:

  - Avoid FORK after COMM when synthesizing records for pre-existing threads (Arnaldo Carvalho de Melo)

  - Reference count struct thread (Arnaldo Carvalho de Melo)

  - Don't keep the session around in 'perf sched', thread refcounting removes that need (Arnaldo Carvalho de Melo)

  - Initialize cpu set in pthread_attr_setaffinity_np() feature test (Adrian Hunter)

  - Only include tsc file for x86 (David Ahern)

  - Compare JOBS to 0 after grep (David Ahern)

  - Improve feature detection messages (Ingo Molnar)

  - Revert "perf: Remove the extra validity check on nr_pages" (Kan Liang)

  - Remove bias offset to find probe point by address (Masami Hiramatsu)

  - Fix build error on ARCH=i386/x86_64/sparc64 (Namhyung Kim)

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 15 insertions, 3 deletions

diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c
index 47b78b3f0325..6da965bdbc2c 100644
--- a/tools/perf/util/cloexec.c
+++ b/tools/perf/util/cloexec.c
@@ -25,6 +25,10 @@ static int perf_flag_probe(void)
 	if (cpu < 0)
 		cpu = 0;
 
+	/*
+	 * Using -1 for the pid is a workaround to avoid gratuitous jump label
+	 * changes.
+	 */
 	while (1) {
 		/* check cloexec flag */
 		fd = sys_perf_event_open(&attr, pid, cpu, -1,
@@ -47,16 +51,24 @@ static int perf_flag_probe(void)
 		  err, strerror_r(err, sbuf, sizeof(sbuf)));
 
 	/* not supported, confirm error related to PERF_FLAG_FD_CLOEXEC */
-	fd = sys_perf_event_open(&attr, pid, cpu, -1, 0);
+	while (1) {
+		fd = sys_perf_event_open(&attr, pid, cpu, -1, 0);
+		if (fd < 0 && pid == -1 && errno == EACCES) {
+			pid = 0;
+			continue;
+		}
+		break;
+	}
 	err = errno;
 
+	if (fd >= 0)
+		close(fd);
+
 	if (WARN_ONCE(fd < 0 && err != EBUSY,
 		      "perf_event_open(..., 0) failed unexpectedly with error %d (%s)\n",
 		      err, strerror_r(err, sbuf, sizeof(sbuf))))
 		return -1;
 
-	close(fd);
-
 	return 0;
 }