Release 4.7 tools/perf/util/cloexec.c

#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;

#ifdef __GLIBC_PREREQ
#if !__GLIBC_PREREQ(2, 6)


int __weak sched_getcpu(void)
{
	errno = ENOSYS;
	return -1;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
vinson lee
vinson lee
16
100.00%
1
100.00%
Total
16
100.00%
1
100.00%

#endif
#endif



static int perf_flag_probe(void)
{
	/* use 'safest' configuration as used in perf_evsel__fallback() */
	struct perf_event_attr attr = {
		.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];

	cpu = sched_getcpu();
	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,
					 PERF_FLAG_FD_CLOEXEC);
		if (fd < 0 && pid == -1 && errno == EACCES) {
			pid = 0;
			continue;
		}
		break;
	}
	err = errno;

	if (fd >= 0) {
		close(fd);
		return 1;
	}

	WARN_ONCE(err != EINVAL && err != EBUSY,
		  "perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error %d (%s)\n",
		  err, strerror_r(err, sbuf, sizeof(sbuf)));

	/* not supported, confirm error related to PERF_FLAG_FD_CLOEXEC */
	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;

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
yann droneaud
yann droneaud
123
47.49%
1
12.50%
adrian hunter
adrian hunter
103
39.77%
3
37.50%
masami hiramatsu
masami hiramatsu
22
8.49%
1
12.50%
jiri olsa
jiri olsa
11
4.25%
3
37.50%
Total
259
100.00%
8
100.00%



unsigned long perf_event_open_cloexec_flag(void)
{
	static bool probed;

	if (!probed) {
		if (perf_flag_probe() <= 0)
			flag = 0;
		probed = true;
	}

	return flag;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
yann droneaud
yann droneaud
37
100.00%
1
100.00%
Total
37
100.00%
1
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
yann droneaud
yann droneaud
179
50.71%
1
10.00%
adrian hunter
adrian hunter
106
30.03%
3
30.00%
masami hiramatsu
masami hiramatsu
25
7.08%
1
10.00%
vinson lee
vinson lee
16
4.53%
1
10.00%
srikar dronamraju
srikar dronamraju
16
4.53%
1
10.00%
jiri olsa
jiri olsa
11
3.12%
3
30.00%
Total
353
100.00%
10
100.00%
  
Directory: tools/perf/util

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.