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-rw-r--r--tools/perf/util/cloexec.c35
1 files changed, 26 insertions, 9 deletions
diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c
index c5d05ec1722..47b78b3f032 100644
--- a/tools/perf/util/cloexec.c
+++ b/tools/perf/util/cloexec.c
@@ -1,7 +1,9 @@
+#include <sched.h>
#include "util.h"
#include "../perf.h"
#include "cloexec.h"
#include "asm/bug.h"
+#include "debug.h"
static unsigned long flag = PERF_FLAG_FD_CLOEXEC;
@@ -9,15 +11,30 @@ static int perf_flag_probe(void)
{
/* use 'safest' configuration as used in perf_evsel__fallback() */
struct perf_event_attr attr = {
- .type = PERF_COUNT_SW_CPU_CLOCK,
+ .type = PERF_TYPE_SOFTWARE,
.config = PERF_COUNT_SW_CPU_CLOCK,
+ .exclude_kernel = 1,
};
int fd;
int err;
+ int cpu;
+ pid_t pid = -1;
+ char sbuf[STRERR_BUFSIZE];
- /* check cloexec flag */
- fd = sys_perf_event_open(&attr, 0, -1, -1,
- PERF_FLAG_FD_CLOEXEC);
+ cpu = sched_getcpu();
+ if (cpu < 0)
+ cpu = 0;
+
+ while (1) {
+ /* check cloexec flag */
+ fd = sys_perf_event_open(&attr, pid, cpu, -1,
+ PERF_FLAG_FD_CLOEXEC);
+ if (fd < 0 && pid == -1 && errno == EACCES) {
+ pid = 0;
+ continue;
+ }
+ break;
+ }
err = errno;
if (fd >= 0) {
@@ -25,17 +42,17 @@ static int perf_flag_probe(void)
return 1;
}
- WARN_ONCE(err != EINVAL,
+ WARN_ONCE(err != EINVAL && err != EBUSY,
"perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error %d (%s)\n",
- err, strerror(err));
+ err, strerror_r(err, sbuf, sizeof(sbuf)));
/* not supported, confirm error related to PERF_FLAG_FD_CLOEXEC */
- fd = sys_perf_event_open(&attr, 0, -1, -1, 0);
+ fd = sys_perf_event_open(&attr, pid, cpu, -1, 0);
err = errno;
- if (WARN_ONCE(fd < 0,
+ if (WARN_ONCE(fd < 0 && err != EBUSY,
"perf_event_open(..., 0) failed unexpectedly with error %d (%s)\n",
- err, strerror(err)))
+ err, strerror_r(err, sbuf, sizeof(sbuf))))
return -1;
close(fd);