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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/cgroup/test_freezer.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | tools/testing/selftests/cgroup/test_freezer.c | 905 |
1 files changed, 905 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..23d8fa4a3 --- /dev/null +++ b/tools/testing/selftests/cgroup/test_freezer.c @@ -0,0 +1,905 @@ +/* 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 <poll.h> +#include <stdlib.h> +#include <sys/inotify.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"); +} + +/* + * Prepare for waiting on cgroup.events file. + */ +static int cg_prepare_for_wait(const char *cgroup) +{ + int fd, ret = -1; + + fd = inotify_init1(0); + if (fd == -1) { + debug("Error: inotify_init1() failed\n"); + return fd; + } + + ret = inotify_add_watch(fd, cg_control(cgroup, "cgroup.events"), + IN_MODIFY); + if (ret == -1) { + debug("Error: inotify_add_watch() failed\n"); + close(fd); + fd = -1; + } + + return fd; +} + +/* + * Wait for an event. If there are no events for 10 seconds, + * treat this an error. + */ +static int cg_wait_for(int fd) +{ + int ret = -1; + struct pollfd fds = { + .fd = fd, + .events = POLLIN, + }; + + while (true) { + ret = poll(&fds, 1, 10000); + + if (ret == -1) { + if (errno == EINTR) + continue; + debug("Error: poll() failed\n"); + break; + } + + if (ret > 0 && fds.revents & POLLIN) { + ret = 0; + break; + } + } + + return ret; +} + +/* + * 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; +} |