From: Christian Brauner <christian.brauner@xxxxxxxxxx>
Test that the new cgroup.kill feature works as intended.
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: cgroups@xxxxxxxxxxxxxxx
Acked-by: Roman Gushchin <guro@xxxxxx>
Signed-off-by: Christian Brauner <christian.brauner@xxxxxxxxxx>
---
/* v2 */
- Christian Brauner <christian.brauner@xxxxxxxxxx>:
- Remove debug logging (It wasn't very helpful in the first place.).
---
tools/testing/selftests/cgroup/.gitignore | 3 +-
tools/testing/selftests/cgroup/Makefile | 2 +
tools/testing/selftests/cgroup/test_kill.c | 291 +++++++++++++++++++++
3 files changed, 295 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/cgroup/test_kill.c
diff --git a/tools/testing/selftests/cgroup/.gitignore b/tools/testing/selftests/cgroup/.gitignore
index 84cfcabea838..be9643ef6285 100644
--- a/tools/testing/selftests/cgroup/.gitignore
+++ b/tools/testing/selftests/cgroup/.gitignore
@@ -2,4 +2,5 @@
test_memcontrol
test_core
test_freezer
-test_kmem
\ No newline at end of file
+test_kmem
+test_kill
diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile
index f027d933595b..59e222460581 100644
--- a/tools/testing/selftests/cgroup/Makefile
+++ b/tools/testing/selftests/cgroup/Makefile
@@ -9,6 +9,7 @@ TEST_GEN_PROGS = test_memcontrol
TEST_GEN_PROGS += test_kmem
TEST_GEN_PROGS += test_core
TEST_GEN_PROGS += test_freezer
+TEST_GEN_PROGS += test_kill
include ../lib.mk
@@ -16,3 +17,4 @@ $(OUTPUT)/test_memcontrol: cgroup_util.c ../clone3/clone3_selftests.h
$(OUTPUT)/test_kmem: cgroup_util.c ../clone3/clone3_selftests.h
$(OUTPUT)/test_core: cgroup_util.c ../clone3/clone3_selftests.h
$(OUTPUT)/test_freezer: cgroup_util.c ../clone3/clone3_selftests.h
+$(OUTPUT)/test_kill: cgroup_util.c ../clone3/clone3_selftests.h ../pidfd/pidfd.h
diff --git a/tools/testing/selftests/cgroup/test_kill.c b/tools/testing/selftests/cgroup/test_kill.c
new file mode 100644
index 000000000000..3e1132deed33
--- /dev/null
+++ b/tools/testing/selftests/cgroup/test_kill.c
@@ -0,0 +1,291 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include <errno.h>
+#include <linux/limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "../kselftest.h"
+#include "../pidfd/pidfd.h"
+#include "cgroup_util.h"
+
+/*
+ * Kill the given cgroup and wait for the inotify signal.
+ * If there are no events in 10 seconds, treat this as an error.
+ * Then check that the cgroup is in the desired state.
+ */
+static int cg_kill_wait(const char *cgroup)
+{
+ int fd, ret = -1;
+
+ fd = cg_prepare_for_wait(cgroup);
+ if (fd < 0)
+ return fd;
+
+ ret = cg_write(cgroup, "cgroup.kill", "1");
+ if (ret)
+ goto out;
+
+ ret = cg_wait_for(fd);
+ if (ret)
+ goto out;
+
+ ret = cg_read_strcmp(cgroup, "cgroup.events", "populated 0\n");
+out:
+ close(fd);
+ return ret;
+}
+
+/*
+ * A simple process running in a sleep loop until being
+ * re-parented.
+ */
+static int child_fn(const char *cgroup, void *arg)
+{
+ int ppid = getppid();
+
+ while (getppid() == ppid)
+ usleep(1000);
+
+ return getppid() == ppid;
+}
+
+static int test_cgkill_simple(const char *root)
+{
+ pid_t pids[100];
+ int ret = KSFT_FAIL;
+ char *cgroup = NULL;
+ int i;
+
+ cgroup = cg_name(root, "cg_test_simple");
+ if (!cgroup)
+ goto cleanup;
+
+ if (cg_create(cgroup))
+ goto cleanup;
+
+ for (i = 0; i < 100; i++)
+ pids[i] = cg_run_nowait(cgroup, child_fn, NULL);
+
+ if (cg_wait_for_proc_count(cgroup, 100))
+ goto cleanup;
+
+ if (cg_write(cgroup, "cgroup.kill", "1"))
+ goto cleanup;
+
+ if (cg_read_strcmp(cgroup, "cgroup.events", "populated 1\n"))
+ goto cleanup;
+
+ if (cg_kill_wait(cgroup))
+ goto cleanup;
+
+ if (cg_read_strcmp(cgroup, "cgroup.events", "populated 0\n"))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ for (i = 0; i < 100; i++)
+ wait_for_pid(pids[i]);
+
+ if (cgroup)
+ cg_destroy(cgroup);
+ free(cgroup);
+ return ret;
+}
+
+/*
+ * The test creates the following hierarchy:
+ * A
+ * / / \ \
+ * B E I K
+ * /\ |
+ * C D F
+ * |
+ * G
+ * |
+ * H
+ *
+ * with a process in C, H and 3 processes in K.
+ * Then it tries to kill the whole tree.
+ */
+static int test_cgkill_tree(const char *root)
+{
+ pid_t pids[5];
+ char *cgroup[10] = {0};
+ int ret = KSFT_FAIL;
+ int i;
+
+ cgroup[0] = cg_name(root, "cg_test_tree_A");
+ if (!cgroup[0])
+ goto cleanup;
+
+ cgroup[1] = cg_name(cgroup[0], "B");
+ if (!cgroup[1])
+ goto cleanup;
+
+ cgroup[2] = cg_name(cgroup[1], "C");
+ if (!cgroup[2])
+ goto cleanup;
+
+ cgroup[3] = cg_name(cgroup[1], "D");
+ if (!cgroup[3])
+ goto cleanup;
+
+ cgroup[4] = cg_name(cgroup[0], "E");
+ if (!cgroup[4])
+ goto cleanup;
+
+ cgroup[5] = cg_name(cgroup[4], "F");
+ if (!cgroup[5])
+ goto cleanup;
+
+ cgroup[6] = cg_name(cgroup[5], "G");
+ if (!cgroup[6])
+ goto cleanup;
+
+ cgroup[7] = cg_name(cgroup[6], "H");
+ if (!cgroup[7])
+ goto cleanup;
+
+ cgroup[8] = cg_name(cgroup[0], "I");
+ if (!cgroup[8])
+ goto cleanup;
+
+ cgroup[9] = cg_name(cgroup[0], "K");
+ if (!cgroup[9])
+ goto cleanup;
+
+ for (i = 0; i < 10; i++)
+ if (cg_create(cgroup[i]))
+ goto cleanup;
+
+ pids[0] = cg_run_nowait(cgroup[2], child_fn, NULL);
+ pids[1] = cg_run_nowait(cgroup[7], child_fn, NULL);
+ pids[2] = cg_run_nowait(cgroup[9], child_fn, NULL);
+ pids[3] = cg_run_nowait(cgroup[9], child_fn, NULL);
+ pids[4] = cg_run_nowait(cgroup[9], child_fn, NULL);
+
+ /*
+ * Wait until all child processes will enter
+ * corresponding cgroups.
+ */
+
+ if (cg_wait_for_proc_count(cgroup[2], 1) ||
+ cg_wait_for_proc_count(cgroup[7], 1) ||
+ cg_wait_for_proc_count(cgroup[9], 3))
+ goto cleanup;
+
+ /*
+ * Kill A and check that we get an empty notification.
+ */
+ if (cg_kill_wait(cgroup[0]))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ for (i = 0; i < 5; i++)
+ wait_for_pid(pids[i]);
+
+ for (i = 9; i >= 0 && cgroup[i]; i--) {
+ cg_destroy(cgroup[i]);
+ free(cgroup[i]);
+ }
+
+ return ret;
+}
+
+static int forkbomb_fn(const char *cgroup, void *arg)
+{
+ int ppid;
+
+ fork();
+ fork();
+
+ ppid = getppid();
+
+ while (getppid() == ppid)
+ usleep(1000);
+
+ return getppid() == ppid;
+}
+
+/*
+ * The test runs a fork bomb in a cgroup and tries to kill it.
+ */
+static int test_cgkill_forkbomb(const char *root)
+{
+ int ret = KSFT_FAIL;
+ char *cgroup = NULL;
+ pid_t pid = -ESRCH;
+
+ cgroup = cg_name(root, "cg_forkbomb_test");
+ if (!cgroup)
+ goto cleanup;
+
+ if (cg_create(cgroup))
+ goto cleanup;
+
+ pid = cg_run_nowait(cgroup, forkbomb_fn, NULL);
+ if (pid < 0)
+ goto cleanup;
+
+ usleep(100000);
+
+ if (cg_kill_wait(cgroup))
+ goto cleanup;
+
+ if (cg_wait_for_proc_count(cgroup, 0))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (cgroup)
+ cg_destroy(cgroup);
+ if (pid > 0)
+ wait_for_pid(pid);
+ free(cgroup);
+ return ret;
+}
+
+#define T(x) { x, #x }
+struct cgkill_test {
+ int (*fn)(const char *root);
+ const char *name;
+} tests[] = {
+ T(test_cgkill_simple),
+ T(test_cgkill_tree),
+ T(test_cgkill_forkbomb),
+};
+#undef T
+
+int main(int argc, char *argv[])
+{
+ char root[PATH_MAX];
+ int i, ret = EXIT_SUCCESS;
+
+ if (cg_find_unified_root(root, sizeof(root)))
+ ksft_exit_skip("cgroup v2 isn't mounted\n");
+ for (i = 0; i < ARRAY_SIZE(tests); i++) {
+ switch (tests[i].fn(root)) {
+ case KSFT_PASS:
+ ksft_test_result_pass("%s\n", tests[i].name);
+ break;
+ case KSFT_SKIP:
+ ksft_test_result_skip("%s\n", tests[i].name);
+ break;
+ default:
+ ret = EXIT_FAILURE;
+ ksft_test_result_fail("%s\n", tests[i].name);
+ break;
+ }
+ }
+
+ return ret;
+}
--
2.27.0
