#include "evlist.h"
#include "evsel.h"
#include "thread_map.h"
#include "cpumap.h"
#include "tests.h"

#include <signal.h>

static int exited;
static int nr_exit;

static void sig_handler(int sig __maybe_unused)
{
	exited = 1;
}

/*
 * perf_evlist__prepare_workload will send a SIGUSR1 if the fork fails, since
 * we asked by setting its exec_error to this handler.
 */
static void workload_exec_failed_signal(int signo __maybe_unused,
					siginfo_t *info __maybe_unused,
					void *ucontext __maybe_unused)
{
	exited	= 1;
	nr_exit = -1;
}

/*
 * This test will start a workload that does nothing then it checks
 * if the number of exit event reported by the kernel is 1 or not
 * in order to check the kernel returns correct number of event.
 */
int test__task_exit(int subtest __maybe_unused)
{
	int err = -1;
	union perf_event *event;
	struct perf_evsel *evsel;
	struct perf_evlist *evlist;
	struct target target = {
		.uid		= UINT_MAX,
		.uses_mmap	= true,
	};
	const char *argv[] = { "true", NULL };
	char sbuf[STRERR_BUFSIZE];
	struct cpu_map *cpus;
	struct thread_map *threads;

	signal(SIGCHLD, sig_handler);

	evlist = perf_evlist__new_default();
	if (evlist == NULL) {
		pr_debug("perf_evlist__new_default\n");
		return -1;
	}

	/*
	 * Create maps of threads and cpus to monitor. In this case
	 * we start with all threads and cpus (-1, -1) but then in
	 * perf_evlist__prepare_workload we'll fill in the only thread
	 * we're monitoring, the one forked there.
	 */
	cpus = cpu_map__dummy_new();
	threads = thread_map__new_by_tid(-1);
	if (!cpus || !threads) {
		err = -ENOMEM;
		pr_debug("Not enough memory to create thread/cpu maps\n");
		goto out_free_maps;
	}

	perf_evlist__set_maps(evlist, cpus, threads);

	cpus	= NULL;
	threads = NULL;

	err = perf_evlist__prepare_workload(evlist, &target, argv, false,
					    workload_exec_failed_signal);
	if (err < 0) {
		pr_debug("Couldn't run the workload!\n");
		goto out_delete_evlist;
	}

	evsel = perf_evlist__first(evlist);
	evsel->attr.task = 1;
	evsel->attr.sample_freq = 0;
	evsel->attr.inherit = 0;
	evsel->attr.watermark = 0;
	evsel->attr.wakeup_events = 1;
	evsel->attr.exclude_kernel = 1;

	err = perf_evlist__open(evlist);
	if (err < 0) {
		pr_debug("Couldn't open the evlist: %s\n",
			 str_error_r(-err, sbuf, sizeof(sbuf)));
		goto out_delete_evlist;
	}

	if (perf_evlist__mmap(evlist, 128, true) < 0) {
		pr_debug("failed to mmap events: %d (%s)\n", errno,
			 str_error_r(errno, sbuf, sizeof(sbuf)));
		goto out_delete_evlist;
	}

	perf_evlist__start_workload(evlist);

retry:
	while ((event = perf_evlist__mmap_read(evlist, 0)) != NULL) {
		if (event->header.type == PERF_RECORD_EXIT)
			nr_exit++;

		perf_evlist__mmap_consume(evlist, 0);
	}

	if (!exited || !nr_exit) {
		perf_evlist__poll(evlist, -1);
		goto retry;
	}

	if (nr_exit != 1) {
		pr_debug("received %d EXIT records\n", nr_exit);
		err = -1;
	}

out_free_maps:
	cpu_map__put(cpus);
	thread_map__put(threads);
out_delete_evlist:
	perf_evlist__delete(evlist);
	return err;
}
tp_core.h?id=433e19cf33d34bb6751c874a9c00980552fe508c'>l2tp_core.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='433e19cf33d34bb6751c874a9c00980552fe508c'/><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>Dexuan Cui &lt;decui@microsoft.com&gt;</td><td class='right'>2017-01-28 11:46:02 -0700</td></tr>
<tr><th>committer</th><td>Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;</td><td class='right'>2017-01-31 10:59:48 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/l2tp/l2tp_core.h?id=433e19cf33d34bb6751c874a9c00980552fe508c'>433e19cf33d34bb6751c874a9c00980552fe508c</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/l2tp/l2tp_core.h?id=433e19cf33d34bb6751c874a9c00980552fe508c'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=433e19cf33d34bb6751c874a9c00980552fe508c'>ce6547ef2987fbb289fa28f03536328a42781651</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/l2tp/l2tp_core.h?id=433e19cf33d34bb6751c874a9c00980552fe508c'>net/l2tp/l2tp_core.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/l2tp/l2tp_core.h?id=191e885a2e130e639bb0c8ee350d7047294f2ce6'>191e885a2e130e639bb0c8ee350d7047294f2ce6</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/l2tp/l2tp_core.h?id=433e19cf33d34bb6751c874a9c00980552fe508c&amp;id2=191e885a2e130e639bb0c8ee350d7047294f2ce6'>diff</a>)</td></tr></table>
<div class='commit-subject'>Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()</div><div class='commit-msg'>Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
added the proper mb(), but removed the test "prev_write_sz &lt; pending_sz"
when making the signal decision.

As a result, the guest can signal the host unnecessarily,
and then the host can throttle the guest because the host
thinks the guest is buggy or malicious; finally the user
running stress test can perceive intermittent freeze of
the guest.

This patch brings back the test, and properly handles the
in-place consumption APIs used by NetVSC (see get_next_pkt_raw(),
put_pkt_raw() and commit_rd_index()).

Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")

Signed-off-by: Dexuan Cui &lt;decui@microsoft.com&gt;
Reported-by: Rolf Neugebauer &lt;rolf.neugebauer@docker.com&gt;
Tested-by: Rolf Neugebauer &lt;rolf.neugebauer@docker.com&gt;
Cc: "K. Y. Srinivasan" &lt;kys@microsoft.com&gt;
Cc: Haiyang Zhang &lt;haiyangz@microsoft.com&gt;
Cc: Stephen Hemminger &lt;sthemmin@microsoft.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: K. Y. Srinivasan &lt;kys@microsoft.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=433e19cf33d34bb6751c874a9c00980552fe508c'>Diffstat</a> (limited to 'net/l2tp/l2tp_core.h')</div><table summary='diffstat' class='diffstat'>