diff --git a/tools/testing/selftests/cgroup/test_kill.c b/tools/testing/selftests/cgroup/test_kill.c index 99cafd9dc013..bac1ddd8cb94 100644 --- a/tools/testing/selftests/cgroup/test_kill.c +++ b/tools/testing/selftests/cgroup/test_kill.c @@ -7,6 +7,7 @@ #include #include #include +#include #include #include "kselftest.h" @@ -261,6 +262,59 @@ static int test_cgkill_forkbomb(const char *root) return ret; } +/* + * Test that a cgroup that was killed in the past can still be the target + * of clone3(CLONE_INTO_CGROUP): writing cgroup.kill must only kill the + * tasks in the cgroup at the time of the write, not tasks cloned into + * it afterwards. + */ +static int test_cgkill_clone_into_killed(const char *root) +{ + pid_t pid; + int cgroup_fd = -EBADF; + int ret = KSFT_FAIL; + char *cgroup = NULL; + + cgroup = cg_name(root, "cg_test_clone_into_killed"); + if (!cgroup) + goto cleanup; + + if (cg_create(cgroup)) + goto cleanup; + + /* Kill the cgroup while it is still empty. */ + if (cg_write(cgroup, "cgroup.kill", "1")) + goto cleanup; + + cgroup_fd = dirfd_open_opath(cgroup); + if (cgroup_fd < 0) + goto cleanup; + + pid = clone_into_cgroup(cgroup_fd); + if (pid < 0) { + if (errno == ENOSYS) + ret = KSFT_SKIP; + goto cleanup; + } + + if (pid == 0) + exit(EXIT_SUCCESS); + + /* The child must not be SIGKILLed; it has to exit cleanly. */ + if (clone_reap(pid, WEXITED) != EXIT_SUCCESS) + goto cleanup; + + ret = KSFT_PASS; + +cleanup: + if (cgroup_fd >= 0) + close(cgroup_fd); + if (cgroup) + cg_destroy(cgroup); + free(cgroup); + return ret; +} + #define T(x) { x, #x } struct cgkill_test { int (*fn)(const char *root); @@ -269,6 +323,7 @@ struct cgkill_test { T(test_cgkill_simple), T(test_cgkill_tree), T(test_cgkill_forkbomb), + T(test_cgkill_clone_into_killed), }; #undef T