Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a7f89616 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-5.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 

Pull cgroup fix from Tejun Heo:
 "Roman found and fixed a bug in the cgroup2 freezer which allows new
  child cgroup to escape frozen state"

* 'for-5.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: freezer: fix frozen state inheritance
  kselftests: cgroup: add freezer mkdir test
parents 1b304a1a 97a61369

kernel/cgroup/cgroup.c

+9 −1
Original line number Diff line number Diff line
@@ -5255,8 +5255,16 @@ static struct cgroup *cgroup_create(struct cgroup *parent) 
	 * if the parent has to be frozen, the child has too.

	 */

	cgrp->freezer.e_freeze = parent->freezer.e_freeze;

	if (cgrp->freezer.e_freeze)

	if (cgrp->freezer.e_freeze) {

		/*

		 * Set the CGRP_FREEZE flag, so when a process will be

		 * attached to the child cgroup, it will become frozen.

		 * At this point the new cgroup is unpopulated, so we can

		 * consider it frozen immediately.

		 */

		set_bit(CGRP_FREEZE, &cgrp->flags);

		set_bit(CGRP_FROZEN, &cgrp->flags);

	}



	spin_lock_irq(&css_set_lock);

	for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp)) {

tools/testing/selftests/cgroup/test_freezer.c

+54 −0
Original line number Diff line number Diff line
@@ -447,6 +447,59 @@ static int test_cgfreezer_forkbomb(const char *root) 
	return ret;

}



/*

 * The test creates a cgroups and freezes it. Then it creates a child cgroup

 * and populates it with a task. After that it checks that the child cgroup

 * is frozen and the parent cgroup remains frozen too.

 */

static int test_cgfreezer_mkdir(const char *root)

{

	int ret = KSFT_FAIL;

	char *parent, *child = NULL;

	int pid;



	parent = cg_name(root, "cg_test_mkdir_A");

	if (!parent)

		goto cleanup;



	child = cg_name(parent, "cg_test_mkdir_B");

	if (!child)

		goto cleanup;



	if (cg_create(parent))

		goto cleanup;



	if (cg_freeze_wait(parent, true))

		goto cleanup;



	if (cg_create(child))

		goto cleanup;



	pid = cg_run_nowait(child, child_fn, NULL);

	if (pid < 0)

		goto cleanup;



	if (cg_wait_for_proc_count(child, 1))

		goto cleanup;



	if (cg_check_frozen(child, true))

		goto cleanup;



	if (cg_check_frozen(parent, true))

		goto cleanup;



	ret = KSFT_PASS;



cleanup:

	if (child)

		cg_destroy(child);

	free(child);

	if (parent)

		cg_destroy(parent);

	free(parent);

	return ret;

}



/*

 * The test creates two nested cgroups, freezes the parent

 * and removes the child. Then it checks that the parent cgroup
@@ -815,6 +868,7 @@ struct cgfreezer_test { 
	T(test_cgfreezer_simple),

	T(test_cgfreezer_tree),

	T(test_cgfreezer_forkbomb),

	T(test_cgfreezer_mkdir),

	T(test_cgfreezer_rmdir),

	T(test_cgfreezer_migrate),

	T(test_cgfreezer_ptrace),