From: Christian Kellner christian@kellner.me

Add tests that check that if pid namespaces are configured the fdinfo file of a pidfd contains an NSpid: entry containing the process id in the current and additionally all nested namespaces.

Signed-off-by: Christian Kellner christian@kellner.me --- tools/testing/selftests/pidfd/Makefile | 2 +- tools/testing/selftests/pidfd/pidfd.h | 12 +++ .../selftests/pidfd/pidfd_fdinfo_test.c | 98 +++++++++++++++++++ tools/testing/selftests/pidfd/pidfd_test.c | 12 --- 4 files changed, 111 insertions(+), 13 deletions(-) create mode 100644 tools/testing/selftests/pidfd/pidfd_fdinfo_test.c

diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile index 7550f08822a3..43db1b98e845 100644 --- a/tools/testing/selftests/pidfd/Makefile +++ b/tools/testing/selftests/pidfd/Makefile @@ -1,7 +1,7 @@ # SPDX-License-Identifier: GPL-2.0-only CFLAGS += -g -I../../../../usr/include/ -pthread

-TEST_GEN_PROGS := pidfd_test pidfd_open_test pidfd_poll_test pidfd_wait +TEST_GEN_PROGS := pidfd_test pidfd_fdinfo_test pidfd_open_test pidfd_poll_test pidfd_wait

include ../lib.mk

diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h index c6bc68329f4b..2946d788645b 100644 --- a/tools/testing/selftests/pidfd/pidfd.h +++ b/tools/testing/selftests/pidfd/pidfd.h @@ -84,4 +84,16 @@ static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags); }

+static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *)) +{ + size_t stack_size = 1024; + char *stack[1024] = { 0 }; + +#ifdef __ia64__ + return __clone2(fn, stack, stack_size, flags | SIGCHLD, NULL, pidfd); +#else + return clone(fn, stack + stack_size, flags | SIGCHLD, NULL, pidfd); +#endif +} + #endif /* __PIDFD_H */ diff --git a/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c new file mode 100644 index 000000000000..fbae502ad8ad --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_fdinfo_test.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include <errno.h> +#include <fcntl.h> +#include <linux/types.h> +#include <sched.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <syscall.h> +#include <sys/wait.h> + +#include "pidfd.h" +#include "../kselftest.h" + +static int child_fdinfo_nspid_test(void *args) +{ + ksft_print_msg("Child: pid %d\n", getpid()); + return 0; +} + +static int compare_fdinfo_nspid(int pidfd, char *expect, size_t len) +{ + char path[512]; + FILE *f; + size_t n = 0; + ssize_t k; + char *line = NULL; + int r = -1; + + snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", pidfd); + + f = fopen(path, "re"); + if (!f) + return -1; + + while ((k = getline(&line, &n, f)) != -1) { + if (strncmp(line, "NSpid:", 6)) + continue; + + line[k - 1] = '\0'; + ksft_print_msg("Child: fdinfo NSpid line: '%s'.\n", line); + r = strncmp(line + 6, expect, len); + break; + } + + free(line); + fclose(f); + + return r; +} + +static void test_pidfd_fdinfo_nspid(void) +{ + char expect[512]; + int pid, pidfd = 0; + int n, r; + const char *test_name = "pidfd check for NSpid information in fdinfo"; + + pid = pidfd_clone(CLONE_PIDFD | CLONE_NEWPID | CLONE_NEWUSER, &pidfd, + child_fdinfo_nspid_test); + if (pid < 0) + ksft_exit_fail_msg( + "%s test: pidfd_clone failed (ret %d, errno %d)\n", + test_name, pid, errno); + + ksft_print_msg("Parent: child-pid: %d\n", pid); + + /* The child will have pid 1 in the new pid namespace, + * so the line must be 'NSPid:\t<pid>\t1' + */ + n = snprintf(expect, sizeof(expect), "\t%d\t%d", pid, 1); + r = compare_fdinfo_nspid(pidfd, expect, n); + + (void)close(pidfd); + + if (wait_for_pid(pid)) + ksft_exit_fail_msg( + "%s test: waitpid failed (ret %d, errno %d)\n", + test_name, r, errno); + + if (r != 0) + ksft_exit_fail_msg("%s test: Failed\n", test_name); + else + ksft_test_result_pass("%s test: Passed\n", test_name); +} + +int main(int argc, char **argv) +{ + ksft_print_header(); + ksft_set_plan(1); + + test_pidfd_fdinfo_nspid(); + + return ksft_exit_pass(); +} diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c index 7aff2d3b42c0..9cf0b6b3e389 100644 --- a/tools/testing/selftests/pidfd/pidfd_test.c +++ b/tools/testing/selftests/pidfd/pidfd_test.c @@ -27,18 +27,6 @@

#define MAX_EVENTS 5

-static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *)) -{ - size_t stack_size = 1024; - char *stack[1024] = { 0 }; - -#ifdef __ia64__ - return __clone2(fn, stack, stack_size, flags | SIGCHLD, NULL, pidfd); -#else - return clone(fn, stack + stack_size, flags | SIGCHLD, NULL, pidfd); -#endif -} - static int signal_received;

static void set_signal_received_on_sigusr1(int sig)