Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
+63
-1
+9
-1
kernel/cgroup/cgroup.c
+9
-1
kernel/cgroup/cgroup.c
···
5255
5255
* if the parent has to be frozen, the child has too.
5256
5256
*/
5257
5257
cgrp->freezer.e_freeze = parent->freezer.e_freeze;
5258
-
if (cgrp->freezer.e_freeze)
5258
+
if (cgrp->freezer.e_freeze) {
5259
+
/*
5260
+
* Set the CGRP_FREEZE flag, so when a process will be
5261
+
* attached to the child cgroup, it will become frozen.
5262
+
* At this point the new cgroup is unpopulated, so we can
5263
+
* consider it frozen immediately.
5264
+
*/
5265
+
set_bit(CGRP_FREEZE, &cgrp->flags);
5259
5266
set_bit(CGRP_FROZEN, &cgrp->flags);
5267
+
}
5260
5268
5261
5269
spin_lock_irq(&css_set_lock);
5262
5270
for (tcgrp = cgrp; tcgrp; tcgrp = cgroup_parent(tcgrp)) {
+54
tools/testing/selftests/cgroup/test_freezer.c
+54
tools/testing/selftests/cgroup/test_freezer.c
···
448
448
}
449
449
450
450
/*
451
+
* The test creates a cgroups and freezes it. Then it creates a child cgroup
452
+
* and populates it with a task. After that it checks that the child cgroup
453
+
* is frozen and the parent cgroup remains frozen too.
454
+
*/
455
+
static int test_cgfreezer_mkdir(const char *root)
456
+
{
457
+
int ret = KSFT_FAIL;
458
+
char *parent, *child = NULL;
459
+
int pid;
460
+
461
+
parent = cg_name(root, "cg_test_mkdir_A");
462
+
if (!parent)
463
+
goto cleanup;
464
+
465
+
child = cg_name(parent, "cg_test_mkdir_B");
466
+
if (!child)
467
+
goto cleanup;
468
+
469
+
if (cg_create(parent))
470
+
goto cleanup;
471
+
472
+
if (cg_freeze_wait(parent, true))
473
+
goto cleanup;
474
+
475
+
if (cg_create(child))
476
+
goto cleanup;
477
+
478
+
pid = cg_run_nowait(child, child_fn, NULL);
479
+
if (pid < 0)
480
+
goto cleanup;
481
+
482
+
if (cg_wait_for_proc_count(child, 1))
483
+
goto cleanup;
484
+
485
+
if (cg_check_frozen(child, true))
486
+
goto cleanup;
487
+
488
+
if (cg_check_frozen(parent, true))
489
+
goto cleanup;
490
+
491
+
ret = KSFT_PASS;
492
+
493
+
cleanup:
494
+
if (child)
495
+
cg_destroy(child);
496
+
free(child);
497
+
if (parent)
498
+
cg_destroy(parent);
499
+
free(parent);
500
+
return ret;
501
+
}
502
+
503
+
/*
451
504
* The test creates two nested cgroups, freezes the parent
452
505
* and removes the child. Then it checks that the parent cgroup
453
506
* remains frozen and it's possible to create a new child
···
868
815
T(test_cgfreezer_simple),
869
816
T(test_cgfreezer_tree),
870
817
T(test_cgfreezer_forkbomb),
818
+
T(test_cgfreezer_mkdir),
871
819
T(test_cgfreezer_rmdir),
872
820
T(test_cgfreezer_migrate),
873
821
T(test_cgfreezer_ptrace),