#include "tests.h"
#include "machine.h"
#include "thread.h"
#include "map.h"
#include "debug.h"

int test__thread_mg_share(int subtest __maybe_unused)
{
	struct machines machines;
	struct machine *machine;

	/* thread group */
	struct thread *leader;
	struct thread *t1, *t2, *t3;
	struct map_groups *mg;

	/* other process */
	struct thread *other, *other_leader;
	struct map_groups *other_mg;

	/*
	 * This test create 2 processes abstractions (struct thread)
	 * with several threads and checks they properly share and
	 * maintain map groups info (struct map_groups).
	 *
	 * thread group (pid: 0, tids: 0, 1, 2, 3)
	 * other  group (pid: 4, tids: 4, 5)
	*/

	machines__init(&machines);
	machine = &machines.host;

	/* create process with 4 threads */
	leader = machine__findnew_thread(machine, 0, 0);
	t1     = machine__findnew_thread(machine, 0, 1);
	t2     = machine__findnew_thread(machine, 0, 2);
	t3     = machine__findnew_thread(machine, 0, 3);

	/* and create 1 separated process, without thread leader */
	other  = machine__findnew_thread(machine, 4, 5);

	TEST_ASSERT_VAL("failed to create threads",
			leader && t1 && t2 && t3 && other);

	mg = leader->mg;
	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 4);

	/* test the map groups pointer is shared */
	TEST_ASSERT_VAL("map groups don't match", mg == t1->mg);
	TEST_ASSERT_VAL("map groups don't match", mg == t2->mg);
	TEST_ASSERT_VAL("map groups don't match", mg == t3->mg);

	/*
	 * Verify the other leader was created by previous call.
	 * It should have shared map groups with no change in
	 * refcnt.
	 */
	other_leader = machine__find_thread(machine, 4, 4);
	TEST_ASSERT_VAL("failed to find other leader", other_leader);

	/*
	 * Ok, now that all the rbtree related operations were done,
	 * lets remove all of them from there so that we can do the
	 * refcounting tests.
	 */
	machine__remove_thread(machine, leader);
	machine__remove_thread(machine, t1);
	machine__remove_thread(machine, t2);
	machine__remove_thread(machine, t3);
	machine__remove_thread(machine, other);
	machine__remove_thread(machine, other_leader);

	other_mg = other->mg;
	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&other_mg->refcnt), 2);

	TEST_ASSERT_VAL("map groups don't match", other_mg == other_leader->mg);

	/* release thread group */
	thread__put(leader);
	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 3);

	thread__put(t1);
	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 2);

	thread__put(t2);
	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&mg->refcnt), 1);

	thread__put(t3);

	/* release other group  */
	thread__put(other_leader);
	TEST_ASSERT_EQUAL("wrong refcnt", atomic_read(&other_mg->refcnt), 1);

	thread__put(other);

	machines__exit(&machines);
	return 0;
}
cd12945551b63ecb1a349d50a6d69d1d6feb4a'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>drivers</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>usb</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/musb?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>musb</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/musb/musb_gadget.c?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>musb_gadget.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='07cd12945551b63ecb1a349d50a6d69d1d6feb4a'/><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>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-26 16:47:28 -0500</td></tr>
<tr><th>committer</th><td>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-26 16:47:28 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/musb/musb_gadget.c?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>07cd12945551b63ecb1a349d50a6d69d1d6feb4a</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/musb/musb_gadget.c?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>75f65eba7eac9277971082a2d5a4cf1370562c0c</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/musb/musb_gadget.c?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>drivers/usb/musb/musb_gadget.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/musb/musb_gadget.c?id=7ce7d89f48834cefece7804d38fc5d85382edf77'>7ce7d89f48834cefece7804d38fc5d85382edf77</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/musb/musb_gadget.c?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a&amp;id2=7ce7d89f48834cefece7804d38fc5d85382edf77'>diff</a>)</td></tr></table>
<div class='commit-subject'>cgroup: don't online subsystems before cgroup_name/path() are operational</div><div class='commit-msg'>While refactoring cgroup creation, a5bca2152036 ("cgroup: factor out
cgroup_create() out of cgroup_mkdir()") incorrectly onlined subsystems
before the new cgroup is associated with it kernfs_node.  This is fine
for cgroup proper but cgroup_name/path() depend on the associated
kernfs_node and if a subsystem makes the new cgroup_subsys_state
visible, which they're allowed to after onlining, it can lead to NULL
dereference.

The current code performs cgroup creation and subsystem onlining in
cgroup_create() and cgroup_mkdir() makes the cgroup and subsystems
visible afterwards.  There's no reason to online the subsystems early
and we can simply drop cgroup_apply_control_enable() call from
cgroup_create() so that the subsystems are onlined and made visible at
the same time.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Reported-by: Konstantin Khlebnikov &lt;khlebnikov@yandex-team.ru&gt;
Fixes: a5bca2152036 ("cgroup: factor out cgroup_create() out of cgroup_mkdir()") 
Cc: stable@vger.kernel.org # v4.6+
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=07cd12945551b63ecb1a349d50a6d69d1d6feb4a'>Diffstat</a> (limited to 'drivers/usb/musb/musb_gadget.c')</div><table summary='diffstat' class='diffstat'>