/*
 * Test backward bit in event attribute, read ring buffer from end to
 * beginning
 */

#include <perf.h>
#include <evlist.h>
#include <sys/prctl.h>
#include "tests.h"
#include "debug.h"

#define NR_ITERS 111

static void testcase(void)
{
	int i;

	for (i = 0; i < NR_ITERS; i++) {
		char proc_name[10];

		snprintf(proc_name, sizeof(proc_name), "p:%d\n", i);
		prctl(PR_SET_NAME, proc_name);
	}
}

static int count_samples(struct perf_evlist *evlist, int *sample_count,
			 int *comm_count)
{
	int i;

	for (i = 0; i < evlist->nr_mmaps; i++) {
		union perf_event *event;

		perf_mmap__read_catchup(&evlist->backward_mmap[i]);
		while ((event = perf_mmap__read_backward(&evlist->backward_mmap[i])) != NULL) {
			const u32 type = event->header.type;

			switch (type) {
			case PERF_RECORD_SAMPLE:
				(*sample_count)++;
				break;
			case PERF_RECORD_COMM:
				(*comm_count)++;
				break;
			default:
				pr_err("Unexpected record of type %d\n", type);
				return TEST_FAIL;
			}
		}
	}
	return TEST_OK;
}

static int do_test(struct perf_evlist *evlist, int mmap_pages,
		   int *sample_count, int *comm_count)
{
	int err;
	char sbuf[STRERR_BUFSIZE];

	err = perf_evlist__mmap(evlist, mmap_pages, true);
	if (err < 0) {
		pr_debug("perf_evlist__mmap: %s\n",
			 str_error_r(errno, sbuf, sizeof(sbuf)));
		return TEST_FAIL;
	}

	perf_evlist__enable(evlist);
	testcase();
	perf_evlist__disable(evlist);

	err = count_samples(evlist, sample_count, comm_count);
	perf_evlist__munmap(evlist);
	return err;
}


int test__backward_ring_buffer(int subtest __maybe_unused)
{
	int ret = TEST_SKIP, err, sample_count = 0, comm_count = 0;
	char pid[16], sbuf[STRERR_BUFSIZE];
	struct perf_evlist *evlist;
	struct perf_evsel *evsel __maybe_unused;
	struct parse_events_error parse_error;
	struct record_opts opts = {
		.target = {
			.uid = UINT_MAX,
			.uses_mmap = true,
		},
		.freq	      = 0,
		.mmap_pages   = 256,
		.default_interval = 1,
	};

	snprintf(pid, sizeof(pid), "%d", getpid());
	pid[sizeof(pid) - 1] = '\0';
	opts.target.tid = opts.target.pid = pid;

	evlist = perf_evlist__new();
	if (!evlist) {
		pr_debug("Not enough memory to create evlist\n");
		return TEST_FAIL;
	}

	err = perf_evlist__create_maps(evlist, &opts.target);
	if (err < 0) {
		pr_debug("Not enough memory to create thread/cpu maps\n");
		goto out_delete_evlist;
	}

	bzero(&parse_error, sizeof(parse_error));
	/*
	 * Set backward bit, ring buffer should be writing from end. Record
	 * it in aux evlist
	 */
	err = parse_events(evlist, "syscalls:sys_enter_prctl/overwrite/", &parse_error);
	if (err) {
		pr_debug("Failed to parse tracepoint event, try use root\n");
		ret = TEST_SKIP;
		goto out_delete_evlist;
	}

	perf_evlist__config(evlist, &opts, NULL);

	err = perf_evlist__open(evlist);
	if (err < 0) {
		pr_debug("perf_evlist__open: %s\n",
			 str_error_r(errno, sbuf, sizeof(sbuf)));
		goto out_delete_evlist;
	}

	ret = TEST_FAIL;
	err = do_test(evlist, opts.mmap_pages, &sample_count,
		      &comm_count);
	if (err != TEST_OK)
		goto out_delete_evlist;

	if ((sample_count != NR_ITERS) || (comm_count != NR_ITERS)) {
		pr_err("Unexpected counter: sample_count=%d, comm_count=%d\n",
		       sample_count, comm_count);
		goto out_delete_evlist;
	}

	err = do_test(evlist, 1, &sample_count, &comm_count);
	if (err != TEST_OK)
		goto out_delete_evlist;

	ret = TEST_OK;
out_delete_evlist:
	perf_evlist__delete(evlist);
	return ret;
}
2e253&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th><th class='left'>Files</th><th class='left'>Lines</th></tr>
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'>2017-01-24 16:54:39 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-01-24 16:54:39 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ipv6/xfrm6_mode_beet.c?id=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>883af14e67e8b8702b5560aa64c888c0cd0bd66c</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/ipv6/xfrm6_mode_beet.c?id=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>74e3a6b53f5fad9f7848ab1b9f6921b7012940a4</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/ipv6/xfrm6_mode_beet.c?id=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>net/ipv6/xfrm6_mode_beet.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ipv6/xfrm6_mode_beet.c?id=0263d4ebd94b36280608e296cba39b924b6e832b'>0263d4ebd94b36280608e296cba39b924b6e832b</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/ipv6/xfrm6_mode_beet.c?id=883af14e67e8b8702b5560aa64c888c0cd0bd66c&amp;id2=0263d4ebd94b36280608e296cba39b924b6e832b'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ipv6/xfrm6_mode_beet.c?id=aab45453ff5c77200c6da4ac909f7a4392aed17e'>aab45453ff5c77200c6da4ac909f7a4392aed17e</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/ipv6/xfrm6_mode_beet.c?id=883af14e67e8b8702b5560aa64c888c0cd0bd66c&amp;id2=aab45453ff5c77200c6da4ac909f7a4392aed17e'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge branch 'akpm' (patches from Andrew)</div><div class='commit-msg'>Merge fixes from Andrew Morton:
 "26 fixes"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (26 commits)
  MAINTAINERS: add Dan Streetman to zbud maintainers
  MAINTAINERS: add Dan Streetman to zswap maintainers
  mm: do not export ioremap_page_range symbol for external module
  mn10300: fix build error of missing fpu_save()
  romfs: use different way to generate fsid for BLOCK or MTD
  frv: add missing atomic64 operations
  mm, page_alloc: fix premature OOM when racing with cpuset mems update
  mm, page_alloc: move cpuset seqcount checking to slowpath
  mm, page_alloc: fix fast-path race with cpuset update or removal
  mm, page_alloc: fix check for NULL preferred_zone
  kernel/panic.c: add missing \n
  fbdev: color map copying bounds checking
  frv: add atomic64_add_unless()
  mm/mempolicy.c: do not put mempolicy before using its nodemask
  radix-tree: fix private list warnings
  Documentation/filesystems/proc.txt: add VmPin
  mm, memcg: do not retry precharge charges
  proc: add a schedule point in proc_pid_readdir()
  mm: alloc_contig: re-allow CMA to compact FS pages
  mm/slub.c: trace free objects at KERN_INFO
  ...
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>Diffstat</a> (limited to 'net/ipv6/xfrm6_mode_beet.c')</div><table summary='diffstat' class='diffstat'>