diff options
Diffstat (limited to 'tools/perf/util/cloexec.c')
| -rw-r--r-- | tools/perf/util/cloexec.c | 24 |
1 files changed, 21 insertions, 3 deletions
diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c index 47b78b3f0325..85b523885f9d 100644 --- a/tools/perf/util/cloexec.c +++ b/tools/perf/util/cloexec.c @@ -7,6 +7,12 @@ static unsigned long flag = PERF_FLAG_FD_CLOEXEC; +int __weak sched_getcpu(void) +{ + errno = ENOSYS; + return -1; +} + static int perf_flag_probe(void) { /* use 'safest' configuration as used in perf_evsel__fallback() */ @@ -25,6 +31,10 @@ 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 +57,24 @@ 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; } |