diff options
author | Jiri Kosina <jkosina@suse.cz> | 2023-11-01 02:07:35 +0300 |
---|---|---|
committer | Jiri Kosina <jkosina@suse.cz> | 2023-11-01 02:07:35 +0300 |
commit | 20cd569d7ee8fce24e8753f0f43af6c420557b1f (patch) | |
tree | f559cfda594846795aa51c99d96f92d8c912851a /tools/testing/selftests/cgroup/test_cpuset.c | |
parent | 62cc9c3cb3ec1bf31cc116146185ed97b450836a (diff) | |
parent | eeebfe6259ba2d5b0980eb7b0df384eb77e9e4f5 (diff) | |
download | linux-20cd569d7ee8fce24e8753f0f43af6c420557b1f.tar.xz |
Merge branch 'for-6.7/config_pm' into for-linus
- #ifdef CONFIG_PM removal from HID code (Thomas Weißschuh)
Diffstat (limited to 'tools/testing/selftests/cgroup/test_cpuset.c')
-rw-r--r-- | tools/testing/selftests/cgroup/test_cpuset.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/tools/testing/selftests/cgroup/test_cpuset.c b/tools/testing/selftests/cgroup/test_cpuset.c new file mode 100644 index 000000000000..b061ed1e05b4 --- /dev/null +++ b/tools/testing/selftests/cgroup/test_cpuset.c @@ -0,0 +1,275 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/limits.h> +#include <signal.h> + +#include "../kselftest.h" +#include "cgroup_util.h" + +static int idle_process_fn(const char *cgroup, void *arg) +{ + (void)pause(); + return 0; +} + +static int do_migration_fn(const char *cgroup, void *arg) +{ + int object_pid = (int)(size_t)arg; + + if (setuid(TEST_UID)) + return EXIT_FAILURE; + + // XXX checking /proc/$pid/cgroup would be quicker than wait + if (cg_enter(cgroup, object_pid) || + cg_wait_for_proc_count(cgroup, 1)) + return EXIT_FAILURE; + + return EXIT_SUCCESS; +} + +static int do_controller_fn(const char *cgroup, void *arg) +{ + const char *child = cgroup; + const char *parent = arg; + + if (setuid(TEST_UID)) + return EXIT_FAILURE; + + if (!cg_read_strstr(child, "cgroup.controllers", "cpuset")) + return EXIT_FAILURE; + + if (cg_write(parent, "cgroup.subtree_control", "+cpuset")) + return EXIT_FAILURE; + + if (cg_read_strstr(child, "cgroup.controllers", "cpuset")) + return EXIT_FAILURE; + + if (cg_write(parent, "cgroup.subtree_control", "-cpuset")) + return EXIT_FAILURE; + + if (!cg_read_strstr(child, "cgroup.controllers", "cpuset")) + return EXIT_FAILURE; + + return EXIT_SUCCESS; +} + +/* + * Migrate a process between two sibling cgroups. + * The success should only depend on the parent cgroup permissions and not the + * migrated process itself (cpuset controller is in place because it uses + * security_task_setscheduler() in cgroup v1). + * + * Deliberately don't set cpuset.cpus in children to avoid definining migration + * permissions between two different cpusets. + */ +static int test_cpuset_perms_object(const char *root, bool allow) +{ + char *parent = NULL, *child_src = NULL, *child_dst = NULL; + char *parent_procs = NULL, *child_src_procs = NULL, *child_dst_procs = NULL; + const uid_t test_euid = TEST_UID; + int object_pid = 0; + int ret = KSFT_FAIL; + + parent = cg_name(root, "cpuset_test_0"); + if (!parent) + goto cleanup; + parent_procs = cg_name(parent, "cgroup.procs"); + if (!parent_procs) + goto cleanup; + if (cg_create(parent)) + goto cleanup; + + child_src = cg_name(parent, "cpuset_test_1"); + if (!child_src) + goto cleanup; + child_src_procs = cg_name(child_src, "cgroup.procs"); + if (!child_src_procs) + goto cleanup; + if (cg_create(child_src)) + goto cleanup; + + child_dst = cg_name(parent, "cpuset_test_2"); + if (!child_dst) + goto cleanup; + child_dst_procs = cg_name(child_dst, "cgroup.procs"); + if (!child_dst_procs) + goto cleanup; + if (cg_create(child_dst)) + goto cleanup; + + if (cg_write(parent, "cgroup.subtree_control", "+cpuset")) + goto cleanup; + + if (cg_read_strstr(child_src, "cgroup.controllers", "cpuset") || + cg_read_strstr(child_dst, "cgroup.controllers", "cpuset")) + goto cleanup; + + /* Enable permissions along src->dst tree path */ + if (chown(child_src_procs, test_euid, -1) || + chown(child_dst_procs, test_euid, -1)) + goto cleanup; + + if (allow && chown(parent_procs, test_euid, -1)) + goto cleanup; + + /* Fork a privileged child as a test object */ + object_pid = cg_run_nowait(child_src, idle_process_fn, NULL); + if (object_pid < 0) + goto cleanup; + + /* Carry out migration in a child process that can drop all privileges + * (including capabilities), the main process must remain privileged for + * cleanup. + * Child process's cgroup is irrelevant but we place it into child_dst + * as hacky way to pass information about migration target to the child. + */ + if (allow ^ (cg_run(child_dst, do_migration_fn, (void *)(size_t)object_pid) == EXIT_SUCCESS)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (object_pid > 0) { + (void)kill(object_pid, SIGTERM); + (void)clone_reap(object_pid, WEXITED); + } + + cg_destroy(child_dst); + free(child_dst_procs); + free(child_dst); + + cg_destroy(child_src); + free(child_src_procs); + free(child_src); + + cg_destroy(parent); + free(parent_procs); + free(parent); + + return ret; +} + +static int test_cpuset_perms_object_allow(const char *root) +{ + return test_cpuset_perms_object(root, true); +} + +static int test_cpuset_perms_object_deny(const char *root) +{ + return test_cpuset_perms_object(root, false); +} + +/* + * Migrate a process between parent and child implicitely + * Implicit migration happens when a controller is enabled/disabled. + * + */ +static int test_cpuset_perms_subtree(const char *root) +{ + char *parent = NULL, *child = NULL; + char *parent_procs = NULL, *parent_subctl = NULL, *child_procs = NULL; + const uid_t test_euid = TEST_UID; + int object_pid = 0; + int ret = KSFT_FAIL; + + parent = cg_name(root, "cpuset_test_0"); + if (!parent) + goto cleanup; + parent_procs = cg_name(parent, "cgroup.procs"); + if (!parent_procs) + goto cleanup; + parent_subctl = cg_name(parent, "cgroup.subtree_control"); + if (!parent_subctl) + goto cleanup; + if (cg_create(parent)) + goto cleanup; + + child = cg_name(parent, "cpuset_test_1"); + if (!child) + goto cleanup; + child_procs = cg_name(child, "cgroup.procs"); + if (!child_procs) + goto cleanup; + if (cg_create(child)) + goto cleanup; + + /* Enable permissions as in a delegated subtree */ + if (chown(parent_procs, test_euid, -1) || + chown(parent_subctl, test_euid, -1) || + chown(child_procs, test_euid, -1)) + goto cleanup; + + /* Put a privileged child in the subtree and modify controller state + * from an unprivileged process, the main process remains privileged + * for cleanup. + * The unprivileged child runs in subtree too to avoid parent and + * internal-node constraing violation. + */ + object_pid = cg_run_nowait(child, idle_process_fn, NULL); + if (object_pid < 0) + goto cleanup; + + if (cg_run(child, do_controller_fn, parent) != EXIT_SUCCESS) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (object_pid > 0) { + (void)kill(object_pid, SIGTERM); + (void)clone_reap(object_pid, WEXITED); + } + + cg_destroy(child); + free(child_procs); + free(child); + + cg_destroy(parent); + free(parent_subctl); + free(parent_procs); + free(parent); + + return ret; +} + + +#define T(x) { x, #x } +struct cpuset_test { + int (*fn)(const char *root); + const char *name; +} tests[] = { + T(test_cpuset_perms_object_allow), + T(test_cpuset_perms_object_deny), + T(test_cpuset_perms_subtree), +}; +#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"); + + if (cg_read_strstr(root, "cgroup.subtree_control", "cpuset")) + if (cg_write(root, "cgroup.subtree_control", "+cpuset")) + ksft_exit_skip("Failed to set cpuset controller\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; +} |