summaryrefslogtreecommitdiffstats
path: root/tools/testing/selftests/cgroup/test_freezer.c
diff options
context:
space:
mode:
Diffstat (limited to 'tools/testing/selftests/cgroup/test_freezer.c')
-rw-r--r--tools/testing/selftests/cgroup/test_freezer.c848
1 files changed, 848 insertions, 0 deletions
diff --git a/tools/testing/selftests/cgroup/test_freezer.c b/tools/testing/selftests/cgroup/test_freezer.c
new file mode 100644
index 000000000..ff519029f
--- /dev/null
+++ b/tools/testing/selftests/cgroup/test_freezer.c
@@ -0,0 +1,848 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <stdbool.h>
+#include <linux/limits.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/wait.h>
+
+#include "../kselftest.h"
+#include "cgroup_util.h"
+
+#define DEBUG
+#ifdef DEBUG
+#define debug(args...) fprintf(stderr, args)
+#else
+#define debug(args...)
+#endif
+
+/*
+ * Check if the cgroup is frozen by looking at the cgroup.events::frozen value.
+ */
+static int cg_check_frozen(const char *cgroup, bool frozen)
+{
+ if (frozen) {
+ if (cg_read_strstr(cgroup, "cgroup.events", "frozen 1") != 0) {
+ debug("Cgroup %s isn't frozen\n", cgroup);
+ return -1;
+ }
+ } else {
+ /*
+ * Check the cgroup.events::frozen value.
+ */
+ if (cg_read_strstr(cgroup, "cgroup.events", "frozen 0") != 0) {
+ debug("Cgroup %s is frozen\n", cgroup);
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Freeze the given cgroup.
+ */
+static int cg_freeze_nowait(const char *cgroup, bool freeze)
+{
+ return cg_write(cgroup, "cgroup.freeze", freeze ? "1" : "0");
+}
+
+/*
+ * Attach a task to the given cgroup and wait for a cgroup frozen event.
+ * All transient events (e.g. populated) are ignored.
+ */
+static int cg_enter_and_wait_for_frozen(const char *cgroup, int pid,
+ bool frozen)
+{
+ int fd, ret = -1;
+ int attempts;
+
+ fd = cg_prepare_for_wait(cgroup);
+ if (fd < 0)
+ return fd;
+
+ ret = cg_enter(cgroup, pid);
+ if (ret)
+ goto out;
+
+ for (attempts = 0; attempts < 10; attempts++) {
+ ret = cg_wait_for(fd);
+ if (ret)
+ break;
+
+ ret = cg_check_frozen(cgroup, frozen);
+ if (ret)
+ continue;
+ }
+
+out:
+ close(fd);
+ return ret;
+}
+
+/*
+ * Freeze 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_freeze_wait(const char *cgroup, bool freeze)
+{
+ int fd, ret = -1;
+
+ fd = cg_prepare_for_wait(cgroup);
+ if (fd < 0)
+ return fd;
+
+ ret = cg_freeze_nowait(cgroup, freeze);
+ if (ret) {
+ debug("Error: cg_freeze_nowait() failed\n");
+ goto out;
+ }
+
+ ret = cg_wait_for(fd);
+ if (ret)
+ goto out;
+
+ ret = cg_check_frozen(cgroup, freeze);
+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;
+}
+
+/*
+ * A simple test for the cgroup freezer: populated the cgroup with 100
+ * running processes and freeze it. Then unfreeze it. Then it kills all
+ * processes and destroys the cgroup.
+ */
+static int test_cgfreezer_simple(const char *root)
+{
+ 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++)
+ cg_run_nowait(cgroup, child_fn, NULL);
+
+ if (cg_wait_for_proc_count(cgroup, 100))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup, false))
+ goto cleanup;
+
+ if (cg_freeze_wait(cgroup, true))
+ goto cleanup;
+
+ if (cg_freeze_wait(cgroup, false))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ 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 freeze and unfreeze the whole tree.
+ */
+static int test_cgfreezer_tree(const char *root)
+{
+ 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;
+
+ cg_run_nowait(cgroup[2], child_fn, NULL);
+ cg_run_nowait(cgroup[7], child_fn, NULL);
+ cg_run_nowait(cgroup[9], child_fn, NULL);
+ cg_run_nowait(cgroup[9], child_fn, NULL);
+ 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;
+
+ /*
+ * Freeze B.
+ */
+ if (cg_freeze_wait(cgroup[1], true))
+ goto cleanup;
+
+ /*
+ * Freeze F.
+ */
+ if (cg_freeze_wait(cgroup[5], true))
+ goto cleanup;
+
+ /*
+ * Freeze G.
+ */
+ if (cg_freeze_wait(cgroup[6], true))
+ goto cleanup;
+
+ /*
+ * Check that A and E are not frozen.
+ */
+ if (cg_check_frozen(cgroup[0], false))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup[4], false))
+ goto cleanup;
+
+ /*
+ * Freeze A. Check that A, B and E are frozen.
+ */
+ if (cg_freeze_wait(cgroup[0], true))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup[1], true))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup[4], true))
+ goto cleanup;
+
+ /*
+ * Unfreeze B, F and G
+ */
+ if (cg_freeze_nowait(cgroup[1], false))
+ goto cleanup;
+
+ if (cg_freeze_nowait(cgroup[5], false))
+ goto cleanup;
+
+ if (cg_freeze_nowait(cgroup[6], false))
+ goto cleanup;
+
+ /*
+ * Check that C and H are still frozen.
+ */
+ if (cg_check_frozen(cgroup[2], true))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup[7], true))
+ goto cleanup;
+
+ /*
+ * Unfreeze A. Check that A, C and K are not frozen.
+ */
+ if (cg_freeze_wait(cgroup[0], false))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup[2], false))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup[9], false))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ for (i = 9; i >= 0 && cgroup[i]; i--) {
+ cg_destroy(cgroup[i]);
+ free(cgroup[i]);
+ }
+
+ return ret;
+}
+
+/*
+ * A fork bomb emulator.
+ */
+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 freeze it.
+ * Then it kills all processes and checks that cgroup isn't populated
+ * anymore.
+ */
+static int test_cgfreezer_forkbomb(const char *root)
+{
+ int ret = KSFT_FAIL;
+ char *cgroup = NULL;
+
+ cgroup = cg_name(root, "cg_forkbomb_test");
+ if (!cgroup)
+ goto cleanup;
+
+ if (cg_create(cgroup))
+ goto cleanup;
+
+ cg_run_nowait(cgroup, forkbomb_fn, NULL);
+
+ usleep(100000);
+
+ if (cg_freeze_wait(cgroup, true))
+ goto cleanup;
+
+ if (cg_killall(cgroup))
+ goto cleanup;
+
+ if (cg_wait_for_proc_count(cgroup, 0))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (cgroup)
+ cg_destroy(cgroup);
+ free(cgroup);
+ 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
+ * remains frozen and it's possible to create a new child
+ * without unfreezing. The new child is frozen too.
+ */
+static int test_cgfreezer_rmdir(const char *root)
+{
+ int ret = KSFT_FAIL;
+ char *parent, *child = NULL;
+
+ parent = cg_name(root, "cg_test_rmdir_A");
+ if (!parent)
+ goto cleanup;
+
+ child = cg_name(parent, "cg_test_rmdir_B");
+ if (!child)
+ goto cleanup;
+
+ if (cg_create(parent))
+ goto cleanup;
+
+ if (cg_create(child))
+ goto cleanup;
+
+ if (cg_freeze_wait(parent, true))
+ goto cleanup;
+
+ if (cg_destroy(child))
+ goto cleanup;
+
+ if (cg_check_frozen(parent, true))
+ goto cleanup;
+
+ if (cg_create(child))
+ goto cleanup;
+
+ if (cg_check_frozen(child, 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 cgroups: A and B, runs a process in A
+ * and performs several migrations:
+ * 1) A (running) -> B (frozen)
+ * 2) B (frozen) -> A (running)
+ * 3) A (frozen) -> B (frozen)
+ *
+ * On each step it checks the actual state of both cgroups.
+ */
+static int test_cgfreezer_migrate(const char *root)
+{
+ int ret = KSFT_FAIL;
+ char *cgroup[2] = {0};
+ int pid;
+
+ cgroup[0] = cg_name(root, "cg_test_migrate_A");
+ if (!cgroup[0])
+ goto cleanup;
+
+ cgroup[1] = cg_name(root, "cg_test_migrate_B");
+ if (!cgroup[1])
+ goto cleanup;
+
+ if (cg_create(cgroup[0]))
+ goto cleanup;
+
+ if (cg_create(cgroup[1]))
+ goto cleanup;
+
+ pid = cg_run_nowait(cgroup[0], child_fn, NULL);
+ if (pid < 0)
+ goto cleanup;
+
+ if (cg_wait_for_proc_count(cgroup[0], 1))
+ goto cleanup;
+
+ /*
+ * Migrate from A (running) to B (frozen)
+ */
+ if (cg_freeze_wait(cgroup[1], true))
+ goto cleanup;
+
+ if (cg_enter_and_wait_for_frozen(cgroup[1], pid, true))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup[0], false))
+ goto cleanup;
+
+ /*
+ * Migrate from B (frozen) to A (running)
+ */
+ if (cg_enter_and_wait_for_frozen(cgroup[0], pid, false))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup[1], true))
+ goto cleanup;
+
+ /*
+ * Migrate from A (frozen) to B (frozen)
+ */
+ if (cg_freeze_wait(cgroup[0], true))
+ goto cleanup;
+
+ if (cg_enter_and_wait_for_frozen(cgroup[1], pid, true))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup[0], true))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (cgroup[0])
+ cg_destroy(cgroup[0]);
+ free(cgroup[0]);
+ if (cgroup[1])
+ cg_destroy(cgroup[1]);
+ free(cgroup[1]);
+ return ret;
+}
+
+/*
+ * The test checks that ptrace works with a tracing process in a frozen cgroup.
+ */
+static int test_cgfreezer_ptrace(const char *root)
+{
+ int ret = KSFT_FAIL;
+ char *cgroup = NULL;
+ siginfo_t siginfo;
+ int pid;
+
+ cgroup = cg_name(root, "cg_test_ptrace");
+ if (!cgroup)
+ goto cleanup;
+
+ if (cg_create(cgroup))
+ goto cleanup;
+
+ pid = cg_run_nowait(cgroup, child_fn, NULL);
+ if (pid < 0)
+ goto cleanup;
+
+ if (cg_wait_for_proc_count(cgroup, 1))
+ goto cleanup;
+
+ if (cg_freeze_wait(cgroup, true))
+ goto cleanup;
+
+ if (ptrace(PTRACE_SEIZE, pid, NULL, NULL))
+ goto cleanup;
+
+ if (ptrace(PTRACE_INTERRUPT, pid, NULL, NULL))
+ goto cleanup;
+
+ waitpid(pid, NULL, 0);
+
+ /*
+ * Cgroup has to remain frozen, however the test task
+ * is in traced state.
+ */
+ if (cg_check_frozen(cgroup, true))
+ goto cleanup;
+
+ if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo))
+ goto cleanup;
+
+ if (ptrace(PTRACE_DETACH, pid, NULL, NULL))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup, true))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (cgroup)
+ cg_destroy(cgroup);
+ free(cgroup);
+ return ret;
+}
+
+/*
+ * Check if the process is stopped.
+ */
+static int proc_check_stopped(int pid)
+{
+ char buf[PAGE_SIZE];
+ int len;
+
+ len = proc_read_text(pid, 0, "stat", buf, sizeof(buf));
+ if (len == -1) {
+ debug("Can't get %d stat\n", pid);
+ return -1;
+ }
+
+ if (strstr(buf, "(test_freezer) T ") == NULL) {
+ debug("Process %d in the unexpected state: %s\n", pid, buf);
+ return -1;
+ }
+
+ return 0;
+}
+
+/*
+ * Test that it's possible to freeze a cgroup with a stopped process.
+ */
+static int test_cgfreezer_stopped(const char *root)
+{
+ int pid, ret = KSFT_FAIL;
+ char *cgroup = NULL;
+
+ cgroup = cg_name(root, "cg_test_stopped");
+ if (!cgroup)
+ goto cleanup;
+
+ if (cg_create(cgroup))
+ goto cleanup;
+
+ pid = cg_run_nowait(cgroup, child_fn, NULL);
+
+ if (cg_wait_for_proc_count(cgroup, 1))
+ goto cleanup;
+
+ if (kill(pid, SIGSTOP))
+ goto cleanup;
+
+ if (cg_check_frozen(cgroup, false))
+ goto cleanup;
+
+ if (cg_freeze_wait(cgroup, true))
+ goto cleanup;
+
+ if (cg_freeze_wait(cgroup, false))
+ goto cleanup;
+
+ if (proc_check_stopped(pid))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (cgroup)
+ cg_destroy(cgroup);
+ free(cgroup);
+ return ret;
+}
+
+/*
+ * Test that it's possible to freeze a cgroup with a ptraced process.
+ */
+static int test_cgfreezer_ptraced(const char *root)
+{
+ int pid, ret = KSFT_FAIL;
+ char *cgroup = NULL;
+ siginfo_t siginfo;
+
+ cgroup = cg_name(root, "cg_test_ptraced");
+ if (!cgroup)
+ goto cleanup;
+
+ if (cg_create(cgroup))
+ goto cleanup;
+
+ pid = cg_run_nowait(cgroup, child_fn, NULL);
+
+ if (cg_wait_for_proc_count(cgroup, 1))
+ goto cleanup;
+
+ if (ptrace(PTRACE_SEIZE, pid, NULL, NULL))
+ goto cleanup;
+
+ if (ptrace(PTRACE_INTERRUPT, pid, NULL, NULL))
+ goto cleanup;
+
+ waitpid(pid, NULL, 0);
+
+ if (cg_check_frozen(cgroup, false))
+ goto cleanup;
+
+ if (cg_freeze_wait(cgroup, true))
+ goto cleanup;
+
+ /*
+ * cg_check_frozen(cgroup, true) will fail here,
+ * because the task in in the TRACEd state.
+ */
+ if (cg_freeze_wait(cgroup, false))
+ goto cleanup;
+
+ if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo))
+ goto cleanup;
+
+ if (ptrace(PTRACE_DETACH, pid, NULL, NULL))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (cgroup)
+ cg_destroy(cgroup);
+ free(cgroup);
+ return ret;
+}
+
+static int vfork_fn(const char *cgroup, void *arg)
+{
+ int pid = vfork();
+
+ if (pid == 0)
+ while (true)
+ sleep(1);
+
+ return pid;
+}
+
+/*
+ * Test that it's possible to freeze a cgroup with a process,
+ * which called vfork() and is waiting for a child.
+ */
+static int test_cgfreezer_vfork(const char *root)
+{
+ int ret = KSFT_FAIL;
+ char *cgroup = NULL;
+
+ cgroup = cg_name(root, "cg_test_vfork");
+ if (!cgroup)
+ goto cleanup;
+
+ if (cg_create(cgroup))
+ goto cleanup;
+
+ cg_run_nowait(cgroup, vfork_fn, NULL);
+
+ if (cg_wait_for_proc_count(cgroup, 2))
+ goto cleanup;
+
+ if (cg_freeze_wait(cgroup, true))
+ goto cleanup;
+
+ ret = KSFT_PASS;
+
+cleanup:
+ if (cgroup)
+ cg_destroy(cgroup);
+ free(cgroup);
+ return ret;
+}
+
+#define T(x) { x, #x }
+struct cgfreezer_test {
+ int (*fn)(const char *root);
+ const char *name;
+} tests[] = {
+ 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),
+ T(test_cgfreezer_stopped),
+ T(test_cgfreezer_ptraced),
+ T(test_cgfreezer_vfork),
+};
+#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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-03 19:06:55 +0000