[2/2,v2] selftests/timens: add a test for vfork+exit
Commit Message
From: Andrei Vagin <avagin@gmail.com>
* check that a child process is in parent's time namespace after vfork.
* check that a child process is in the target namespace after exec.
Output on success:
1..4
ok 1 parent before vfork
ok 2 child after exec
ok 3 wait for child
ok 4 parent after vfork
# Totals: pass:4 fail:0 xfail:0 xpass:0 skip:0 error:0
Signed-off-by: Andrei Vagin <avagin@gmail.com>
---
v2: - don't create threads from a vfork-ed process.
- use _exit to exit from a vfork-ed process.
tools/testing/selftests/timens/.gitignore | 1 +
tools/testing/selftests/timens/Makefile | 2 +-
tools/testing/selftests/timens/vfork_exec.c | 139 ++++++++++++++++++++
3 files changed, 141 insertions(+), 1 deletion(-)
create mode 100644 tools/testing/selftests/timens/vfork_exec.c
@@ -8,3 +8,4 @@ procfs
timens
timer
timerfd
+vfork_exec
@@ -1,4 +1,4 @@
-TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec futex
+TEST_GEN_PROGS := timens timerfd timer clock_nanosleep procfs exec futex vfork_exec
TEST_GEN_PROGS_EXTENDED := gettime_perf
CFLAGS := -Wall -Werror -pthread
new file mode 100644
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+#include <string.h>
+#include <pthread.h>
+
+#include "log.h"
+#include "timens.h"
+
+#define OFFSET (36000)
+
+struct thread_args {
+ char *tst_name;
+ struct timespec *now;
+};
+
+static void *tcheck(void *_args)
+{
+ struct thread_args *args = _args;
+ struct timespec *now = args->now, tst;
+ int i;
+
+ for (i = 0; i < 2; i++) {
+ _gettime(CLOCK_MONOTONIC, &tst, i);
+ if (abs(tst.tv_sec - now->tv_sec) > 5) {
+ pr_fail("%s: in-thread: unexpected value: %ld (%ld)\n",
+ args->tst_name, tst.tv_sec, now->tv_sec);
+ return (void *)1UL;
+ }
+ }
+ return NULL;
+}
+
+static int check_in_thread(char *tst_name, struct timespec *now)
+{
+ struct thread_args args = {
+ .tst_name = tst_name,
+ .now = now,
+ };
+ pthread_t th;
+ void *retval;
+
+ if (pthread_create(&th, NULL, tcheck, &args))
+ return pr_perror("thread");
+ if (pthread_join(th, &retval))
+ return pr_perror("pthread_join");
+ return !(retval == NULL);
+}
+
+static int check(char *tst_name, struct timespec *now)
+{
+ struct timespec tst;
+ int i;
+
+ for (i = 0; i < 2; i++) {
+ _gettime(CLOCK_MONOTONIC, &tst, i);
+ if (abs(tst.tv_sec - now->tv_sec) > 5)
+ return pr_fail("%s: unexpected value: %ld (%ld)\n",
+ tst_name, tst.tv_sec, now->tv_sec);
+ }
+ if (check_in_thread(tst_name, now))
+ return 1;
+ ksft_test_result_pass("%s\n", tst_name);
+ return 0;
+}
+
+int main(int argc, char *argv[])
+{
+ struct timespec now;
+ int status;
+ pid_t pid;
+
+ if (argc > 1) {
+ char *endptr;
+
+ ksft_cnt.ksft_pass = 1;
+ now.tv_sec = strtoul(argv[1], &endptr, 0);
+ if (*endptr != 0)
+ return pr_perror("strtoul");
+
+ return check("child after exec", &now);
+ }
+
+ nscheck();
+
+ ksft_set_plan(4);
+
+ clock_gettime(CLOCK_MONOTONIC, &now);
+
+ if (unshare_timens())
+ return 1;
+
+ if (_settime(CLOCK_MONOTONIC, OFFSET))
+ return 1;
+
+ if (check("parent before vfork", &now))
+ return 1;
+
+ pid = vfork();
+ if (pid < 0)
+ return pr_perror("fork");
+
+ if (pid == 0) {
+ char now_str[64];
+ char *cargv[] = {"exec", now_str, NULL};
+ char *cenv[] = {NULL};
+
+ /* Check for proper vvar offsets after execve. */
+ snprintf(now_str, sizeof(now_str), "%ld", now.tv_sec + OFFSET);
+ execve("/proc/self/exe", cargv, cenv);
+ pr_perror("execve");
+ _exit(1);
+ }
+
+ if (waitpid(pid, &status, 0) != pid)
+ return pr_perror("waitpid");
+
+ if (status)
+ ksft_exit_fail();
+ ksft_inc_pass_cnt();
+ ksft_test_result_pass("wait for child\n");
+
+ /* Check that we are still in the source timens. */
+ if (check("parent after vfork", &now))
+ return 1;
+
+ ksft_exit_pass();
+ return 0;
+}