diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-13 09:52:01 +0100 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-13 09:52:01 +0100 |
commit | a7f89616b7376495424f682b6086e0c391a89a1d (patch) | |
tree | 55cf3b4ccb41880d6d0282f91370bffddf33c320 | |
parent | 1b304a1ae45de4df7d773f0a39d1100aabca615b (diff) | |
parent | 97a61369830ab085df5aed0ff9256f35b07d425a (diff) |
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
-rw-r--r-- | kernel/cgroup/cgroup.c | 10 | ||||
-rw-r--r-- | tools/testing/selftests/cgroup/test_freezer.c | 54 |
2 files changed, 63 insertions, 1 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index 753afbca549f..8be1da1ebd9a 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -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)) { diff --git a/tools/testing/selftests/cgroup/test_freezer.c b/tools/testing/selftests/cgroup/test_freezer.c index 8219a30853d2..0fc1b6d4b0f9 100644 --- a/tools/testing/selftests/cgroup/test_freezer.c +++ b/tools/testing/selftests/cgroup/test_freezer.c @@ -448,6 +448,59 @@ cleanup: } /* + * 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 * remains frozen and it's possible to create a new child @@ -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), |