This commit adds (and wires in) new test program for checking basic pids controller functionality -- restricting tasks in a cgroup and correct event counting.
Signed-off-by: Michal Koutný mkoutny@suse.com --- tools/testing/selftests/cgroup/.gitignore | 1 + tools/testing/selftests/cgroup/Makefile | 2 + tools/testing/selftests/cgroup/test_pids.c | 178 +++++++++++++++++++++ 3 files changed, 181 insertions(+) create mode 100644 tools/testing/selftests/cgroup/test_pids.c
diff --git a/tools/testing/selftests/cgroup/.gitignore b/tools/testing/selftests/cgroup/.gitignore index ec635a0ef488..952e4448bf07 100644 --- a/tools/testing/selftests/cgroup/.gitignore +++ b/tools/testing/selftests/cgroup/.gitignore @@ -7,5 +7,6 @@ test_hugetlb_memcg test_kill test_kmem test_memcontrol +test_pids test_zswap wait_inotify diff --git a/tools/testing/selftests/cgroup/Makefile b/tools/testing/selftests/cgroup/Makefile index b91f60f3402c..1b897152bab6 100644 --- a/tools/testing/selftests/cgroup/Makefile +++ b/tools/testing/selftests/cgroup/Makefile @@ -15,6 +15,7 @@ TEST_GEN_PROGS += test_hugetlb_memcg TEST_GEN_PROGS += test_kill TEST_GEN_PROGS += test_kmem TEST_GEN_PROGS += test_memcontrol +TEST_GEN_PROGS += test_pids TEST_GEN_PROGS += test_zswap
LOCAL_HDRS += $(selfdir)/clone3/clone3_selftests.h $(selfdir)/pidfd/pidfd.h @@ -29,4 +30,5 @@ $(OUTPUT)/test_hugetlb_memcg: cgroup_util.c $(OUTPUT)/test_kill: cgroup_util.c $(OUTPUT)/test_kmem: cgroup_util.c $(OUTPUT)/test_memcontrol: cgroup_util.c +$(OUTPUT)/test_pids: cgroup_util.c $(OUTPUT)/test_zswap: cgroup_util.c diff --git a/tools/testing/selftests/cgroup/test_pids.c b/tools/testing/selftests/cgroup/test_pids.c new file mode 100644 index 000000000000..9ecb83c6cc5c --- /dev/null +++ b/tools/testing/selftests/cgroup/test_pids.c @@ -0,0 +1,178 @@ +// SPDX-License-Identifier: GPL-2.0 +#define _GNU_SOURCE + +#include <errno.h> +#include <linux/limits.h> +#include <signal.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> + +#include "../kselftest.h" +#include "cgroup_util.h" + +static int run_success(const char *cgroup, void *arg) +{ + return 0; +} + +static int run_pause(const char *cgroup, void *arg) +{ + return pause(); +} + +/* + * This test checks that pids.max prevents forking new children above the + * specified limit in the cgroup. + */ +static int test_pids_max(const char *root) +{ + int ret = KSFT_FAIL; + char *cg_pids; + int pid; + + cg_pids = cg_name(root, "pids_test"); + if (!cg_pids) + goto cleanup; + + if (cg_create(cg_pids)) + goto cleanup; + + if (cg_read_strcmp(cg_pids, "pids.max", "max\n")) + goto cleanup; + + if (cg_write(cg_pids, "pids.max", "2")) + goto cleanup; + + if (cg_enter_current(cg_pids)) + goto cleanup; + + pid = cg_run_nowait(cg_pids, run_pause, NULL); + if (pid < 0) + goto cleanup; + + if (cg_run_nowait(cg_pids, run_success, NULL) != -1 || errno != EAGAIN) + goto cleanup; + + if (kill(pid, SIGINT)) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + cg_enter_current(root); + cg_destroy(cg_pids); + free(cg_pids); + + return ret; +} + +/* + * This test checks that pids.events are counted in cgroup associated with pids.max + */ +static int test_pids_events(const char *root) +{ + int ret = KSFT_FAIL; + char *cg_parent = NULL, *cg_child = NULL; + int pid; + + cg_parent = cg_name(root, "pids_parent"); + cg_child = cg_name(cg_parent, "pids_child"); + if (!cg_parent || !cg_child) + goto cleanup; + + if (cg_create(cg_parent)) + goto cleanup; + if (cg_write(cg_parent, "cgroup.subtree_control", "+pids")) + goto cleanup; + if (cg_create(cg_child)) + goto cleanup; + + if (cg_write(cg_parent, "pids.max", "2")) + goto cleanup; + + if (cg_read_strcmp(cg_child, "pids.max", "max\n")) + goto cleanup; + + if (cg_enter_current(cg_child)) + goto cleanup; + + pid = cg_run_nowait(cg_child, run_pause, NULL); + if (pid < 0) + goto cleanup; + + if (cg_run_nowait(cg_child, run_success, NULL) != -1 || errno != EAGAIN) + goto cleanup; + + if (kill(pid, SIGINT)) + goto cleanup; + + if (cg_read_key_long(cg_child, "pids.events", "max ") != 0) + goto cleanup; + if (cg_read_key_long(cg_parent, "pids.events", "max ") != 1) + goto cleanup; + + + ret = KSFT_PASS; + +cleanup: + cg_enter_current(root); + if (cg_child) + cg_destroy(cg_child); + if (cg_parent) + cg_destroy(cg_parent); + free(cg_child); + free(cg_parent); + + return ret; +} + + + +#define T(x) { x, #x } +struct pids_test { + int (*fn)(const char *root); + const char *name; +} tests[] = { + T(test_pids_max), + T(test_pids_events), +}; +#undef T + +int main(int argc, char **argv) +{ + char root[PATH_MAX]; + + ksft_print_header(); + ksft_set_plan(ARRAY_SIZE(tests)); + if (cg_find_unified_root(root, sizeof(root), NULL)) + ksft_exit_skip("cgroup v2 isn't mounted\n"); + + /* + * Check that pids controller is available: + * pids is listed in cgroup.controllers + */ + if (cg_read_strstr(root, "cgroup.controllers", "pids")) + ksft_exit_skip("pids controller isn't available\n"); + + if (cg_read_strstr(root, "cgroup.subtree_control", "pids")) + if (cg_write(root, "cgroup.subtree_control", "+pids")) + ksft_exit_skip("Failed to set pids controller\n"); + + for (int 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: + ksft_test_result_fail("%s\n", tests[i].name); + break; + } + } + + ksft_finished(); +}