@@ -12828,6 +12828,7 @@ S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux.git
F: samples/pidfd/
F: tools/testing/selftests/pidfd/
+F: tools/testing/selftests/clone3/
K: (?i)pidfd
K: (?i)clone3
K: \b(clone_args|kernel_clone_args)\b
@@ -4,6 +4,7 @@ TARGETS += bpf
TARGETS += breakpoints
TARGETS += capabilities
TARGETS += cgroup
+TARGETS += clone3
TARGETS += cpufreq
TARGETS += cpu-hotplug
TARGETS += drivers/dma-buf
new file mode 100644
@@ -0,0 +1 @@
+clone3_clear_sighand
new file mode 100644
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0-only
+CFLAGS += -g -I../../../../usr/include/
+
+TEST_GEN_PROGS := clone3_clear_sighand
+
+include ../lib.mk
+
new file mode 100644
@@ -0,0 +1,172 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <linux/sched.h>
+#include <linux/types.h>
+#include <sys/syscall.h>
+#include <sys/wait.h>
+
+#include "../kselftest.h"
+
+#ifndef CLONE_CLEAR_SIGHAND
+#define CLONE_CLEAR_SIGHAND 0x100000000ULL
+#endif
+
+#ifndef __NR_clone3
+#define __NR_clone3 -1
+struct clone_args {
+ __aligned_u64 flags;
+ __aligned_u64 pidfd;
+ __aligned_u64 child_tid;
+ __aligned_u64 parent_tid;
+ __aligned_u64 exit_signal;
+ __aligned_u64 stack;
+ __aligned_u64 stack_size;
+ __aligned_u64 tls;
+};
+#endif
+
+static pid_t sys_clone3(struct clone_args *args, size_t size)
+{
+ return syscall(__NR_clone3, args, size);
+}
+
+static void test_clone3_supported(void)
+{
+ pid_t pid;
+ struct clone_args args = {};
+
+ if (__NR_clone3 < 0)
+ ksft_exit_skip("clone3() syscall is not supported\n");
+
+ /* Set to something that will always cause EINVAL. */
+ args.exit_signal = -1;
+ pid = sys_clone3(&args, sizeof(args));
+ if (!pid)
+ exit(EXIT_SUCCESS);
+
+ if (pid > 0) {
+ wait(NULL);
+ ksft_exit_fail_msg(
+ "Managed to create child process with invalid exit_signal\n");
+ }
+
+ if (errno == ENOSYS)
+ ksft_exit_skip("clone3() syscall is not supported\n");
+
+ ksft_print_msg("clone3() syscall supported\n");
+}
+
+static void nop_handler(int signo)
+{
+}
+
+static int wait_for_pid(pid_t pid)
+{
+ int status, ret;
+
+again:
+ ret = waitpid(pid, &status, 0);
+ if (ret == -1) {
+ if (errno == EINTR)
+ goto again;
+
+ return -1;
+ }
+
+ if (!WIFEXITED(status))
+ return -1;
+
+ return WEXITSTATUS(status);
+}
+
+static void test_clone3_clear_sighand(void)
+{
+ int ret;
+ pid_t pid;
+ struct clone_args args = {};
+ struct sigaction act;
+
+ /*
+ * Check that CLONE_CLEAR_SIGHAND and CLONE_SIGHAND are mutually
+ * exclusive.
+ */
+ args.flags |= CLONE_CLEAR_SIGHAND | CLONE_SIGHAND;
+ args.exit_signal = SIGCHLD;
+ pid = sys_clone3(&args, sizeof(args));
+ if (pid > 0)
+ ksft_exit_fail_msg(
+ "clone3(CLONE_CLEAR_SIGHAND | CLONE_SIGHAND) succeeded\n");
+
+ act.sa_handler = nop_handler;
+ ret = sigemptyset(&act.sa_mask);
+ if (ret < 0)
+ ksft_exit_fail_msg("%s - sigemptyset() failed\n",
+ strerror(errno));
+
+ act.sa_flags = 0;
+
+ /* Register signal handler for SIGUSR1 */
+ ret = sigaction(SIGUSR1, &act, NULL);
+ if (ret < 0)
+ ksft_exit_fail_msg(
+ "%s - sigaction(SIGUSR1, &act, NULL) failed\n",
+ strerror(errno));
+
+ /* Register signal handler for SIGUSR2 */
+ ret = sigaction(SIGUSR2, &act, NULL);
+ if (ret < 0)
+ ksft_exit_fail_msg(
+ "%s - sigaction(SIGUSR2, &act, NULL) failed\n",
+ strerror(errno));
+
+ /* Check that CLONE_CLEAR_SIGHAND works. */
+ args.flags = CLONE_CLEAR_SIGHAND;
+ pid = sys_clone3(&args, sizeof(args));
+ if (pid < 0)
+ ksft_exit_fail_msg("%s - clone3(CLONE_CLEAR_SIGHAND) failed\n",
+ strerror(errno));
+
+ if (pid == 0) {
+ ret = sigaction(SIGUSR1, NULL, &act);
+ if (ret < 0)
+ exit(EXIT_FAILURE);
+
+ if (act.sa_handler != SIG_DFL)
+ exit(EXIT_FAILURE);
+
+ ret = sigaction(SIGUSR2, NULL, &act);
+ if (ret < 0)
+ exit(EXIT_FAILURE);
+
+ if (act.sa_handler != SIG_DFL)
+ exit(EXIT_FAILURE);
+
+ exit(EXIT_SUCCESS);
+ }
+
+ ret = wait_for_pid(pid);
+ if (ret)
+ ksft_exit_fail_msg(
+ "Failed to clear signal handler for child process\n");
+
+ ksft_test_result_pass("Cleared signal handlers for child process\n");
+}
+
+int main(int argc, char **argv)
+{
+ ksft_print_header();
+ ksft_set_plan(1);
+
+ test_clone3_supported();
+ test_clone3_clear_sighand();
+
+ return ksft_exit_pass();
+}
Test that CLONE_CLEAR_SIGHAND resets signal handlers to SIG_DFL for the child process and that CLONE_CLEAR_SIGHAND and CLONE_SIGHAND are mutually exclusive. Cc: Florian Weimer <fweimer@redhat.com> Cc: libc-alpha@sourceware.org Cc: linux-api@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> --- /* v1 */ Link: https://lore.kernel.org/r/20191010133518.5420-2-christian.brauner@ubuntu.com /* v2 */ Link: https://lore.kernel.org/r/20191011102537.27502-2-christian.brauner@ubuntu.com - Christian Brauner <christian.brauner@ubuntu.com>: - remove unused variable - reuse variable in child process instead od declaring a new one - move check for mutual exclusivity of CLONE_SIGHAND and CLONE3_CLEAR_SIGHAND to top of test before setting up signal handlers - rename variables /* v3 */ - Christian Brauner <christian.brauner@ubuntu.com>: - s/CLONE3_CLEAR_SIGHAND/CLONE_CLEAR_SIGHAND/g --- MAINTAINERS | 1 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/clone3/.gitignore | 1 + tools/testing/selftests/clone3/Makefile | 7 + .../selftests/clone3/clone3_clear_sighand.c | 172 ++++++++++++++++++ 5 files changed, 182 insertions(+) create mode 100644 tools/testing/selftests/clone3/.gitignore create mode 100644 tools/testing/selftests/clone3/Makefile create mode 100644 tools/testing/selftests/clone3/clone3_clear_sighand.c