diff options
Diffstat (limited to 'tools/perf/util/cloexec.c')
| -rw-r--r-- | tools/perf/util/cloexec.c | 35 |
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); |