#include <sched.h>
#include "util.h"
#include "../perf.h"
#include "cloexec.h"
#include "asm/bug.h"
#include "debug.h"
#include <unistd.h>
#include <asm/unistd.h>
#include <sys/syscall.h>

static unsigned long flag = PERF_FLAG_FD_CLOEXEC;

int __weak sched_getcpu(void)
{
#ifdef __NR_getcpu
	unsigned cpu;
	int err = syscall(__NR_getcpu, &cpu, NULL, NULL);
	if (!err)
		return cpu;
#else
	errno = ENOSYS;
#endif
	return -1;
}

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, str_error_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, str_error_r(err, sbuf, sizeof(sbuf))))
		return -1;

	return 0;
}

unsigned long perf_event_open_cloexec_flag(void)
{
	static bool probed;

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

	return flag;
}
uthor'>author</option>
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/log/'>root</a>/<a href='/cgit.cgi/linux/net-next.git/log/sound'>sound</a>/<a href='/cgit.cgi/linux/net-next.git/log/sound/core'>core</a>/<a href='/cgit.cgi/linux/net-next.git/log/sound/core/sound.c'>sound.c</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/cgit.cgi/linux/net-next.git/log/sound/core/sound.c?showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
rs?id=5906374446386fd16fe562b042429d905d231ec3'>drivers</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='5906374446386fd16fe562b042429d905d231ec3'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-27 12:41:46 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-27 12:41:46 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers?id=5906374446386fd16fe562b042429d905d231ec3'>5906374446386fd16fe562b042429d905d231ec3</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers?id=5906374446386fd16fe562b042429d905d231ec3'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=5906374446386fd16fe562b042429d905d231ec3'>8e8a9f367d1aeba25c644d3fcf096ffc443c4c5a</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers?id=5906374446386fd16fe562b042429d905d231ec3'>drivers</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers?id=2fb78e89405f4321b86274a0c24b30896dd50529'>2fb78e89405f4321b86274a0c24b30896dd50529</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers?id=5906374446386fd16fe562b042429d905d231ec3&amp;id2=2fb78e89405f4321b86274a0c24b30896dd50529'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers?id=57b59ed2e5b91e958843609c7884794e29e6c4cb'>57b59ed2e5b91e958843609c7884794e29e6c4cb</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers?id=5906374446386fd16fe562b042429d905d231ec3&amp;id2=57b59ed2e5b91e958843609c7884794e29e6c4cb'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs</div><div class='commit-msg'>Pull btrfs updates from Chris Mason:
 "Some fixes that we've collected from the list.

  We still have one more pending to nail down a regression in lzo
  compression, but I wanted to get this batch out the door"

* 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: remove -&gt;{get, set}_acl() from btrfs_dir_ro_inode_operations
  Btrfs: disable xattr operations on subvolume directories
  Btrfs: remove old tree_root case in btrfs_read_locked_inode()
  Btrfs: fix truncate down when no_holes feature is enabled
  Btrfs: Fix deadlock between direct IO and fast fsync
  btrfs: fix false enospc error when truncating heavily reflinked file
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=5906374446386fd16fe562b042429d905d231ec3'>Diffstat</a> (limited to 'drivers')</div><table summary='diffstat' class='diffstat'>