From e63f3085709e92bd876e2977a07099d56bbda1c2 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Sun, 28 Jul 2019 00:22:30 +0200 Subject: pidfd: add pidfd_wait tests Add tests for pidfd_wait() and CLONE_WAIT_PID: - test that waitid(P_PIDFD) fails on /proc/ - test that waitid(P_PIDFD) fails on /dev/null - test that waitid(P_PIDFD) can wait on a pidfd - test that waitid(P_PIDFD) can wait on a pidfd and return siginfo_t - test that waitid(P_PIDFD) works with WEXITED - test that waitid(P_PIDFD) works with WSTOPPED - test that waitid(P_PIDFD) works with WUNTRACED - test that waitid(P_PIDFD) works with WCONTINUED - test that waitid(P_PIDFD) works with WNOWAIT - test that waitid(P_PIDFD)works with WNOHANG Signed-off-by: Christian Brauner Reviewed-by: Kees Cook Cc: Arnd Bergmann Cc: "Eric W. Biederman" Cc: Joel Fernandes (Google) Cc: Thomas Gleixner Cc: David Howells Cc: Jann Horn Cc: Andy Lutomirsky Cc: Andrew Morton Cc: Oleg Nesterov Cc: Aleksa Sarai Cc: Linus Torvalds Cc: Al Viro Link: https://lore.kernel.org/r/20190727222229.6516-3-christian@brauner.io --- tools/testing/selftests/pidfd/.gitignore | 1 + tools/testing/selftests/pidfd/Makefile | 2 +- tools/testing/selftests/pidfd/pidfd.h | 25 +++ tools/testing/selftests/pidfd/pidfd_test.c | 14 -- tools/testing/selftests/pidfd/pidfd_wait.c | 271 +++++++++++++++++++++++++++++ 5 files changed, 298 insertions(+), 15 deletions(-) create mode 100644 tools/testing/selftests/pidfd/pidfd_wait.c (limited to 'tools/testing/selftests/pidfd') diff --git a/tools/testing/selftests/pidfd/.gitignore b/tools/testing/selftests/pidfd/.gitignore index 16d84d117bc0..730ef9dc08cc 100644 --- a/tools/testing/selftests/pidfd/.gitignore +++ b/tools/testing/selftests/pidfd/.gitignore @@ -1,2 +1,3 @@ pidfd_open_test pidfd_test +pidfd_wait diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile index 720b2d884b3c..7c97e890f353 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/ -lpthread -TEST_GEN_PROGS := pidfd_test pidfd_open_test +TEST_GEN_PROGS := pidfd_test pidfd_open_test pidfd_wait include ../lib.mk diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h index 8452e910463f..7d7d0ca05e0b 100644 --- a/tools/testing/selftests/pidfd/pidfd.h +++ b/tools/testing/selftests/pidfd/pidfd.h @@ -16,6 +16,26 @@ #include "../kselftest.h" +#ifndef P_PIDFD +#define P_PIDFD 3 +#endif + +#ifndef CLONE_PIDFD +#define CLONE_PIDFD 0x00001000 +#endif + +#ifndef __NR_pidfd_open +#define __NR_pidfd_open -1 +#endif + +#ifndef __NR_pidfd_send_signal +#define __NR_pidfd_send_signal -1 +#endif + +#ifndef __NR_clone3 +#define __NR_clone3 -1 +#endif + /* * The kernel reserves 300 pids via RESERVED_PIDS in kernel/pid.c * That means, when it wraps around any pid < 300 will be skipped. @@ -53,5 +73,10 @@ again: return WEXITSTATUS(status); } +static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, + unsigned int flags) +{ + return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags); +} #endif /* __PIDFD_H */ diff --git a/tools/testing/selftests/pidfd/pidfd_test.c b/tools/testing/selftests/pidfd/pidfd_test.c index 7eaa8a3de262..42e3eb494d72 100644 --- a/tools/testing/selftests/pidfd/pidfd_test.c +++ b/tools/testing/selftests/pidfd/pidfd_test.c @@ -21,20 +21,12 @@ #include "pidfd.h" #include "../kselftest.h" -#ifndef __NR_pidfd_send_signal -#define __NR_pidfd_send_signal -1 -#endif - #define str(s) _str(s) #define _str(s) #s #define CHILD_THREAD_MIN_WAIT 3 /* seconds */ #define MAX_EVENTS 5 -#ifndef CLONE_PIDFD -#define CLONE_PIDFD 0x00001000 -#endif - static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *)) { size_t stack_size = 1024; @@ -47,12 +39,6 @@ static pid_t pidfd_clone(int flags, int *pidfd, int (*fn)(void *)) #endif } -static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, - unsigned int flags) -{ - return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags); -} - static int signal_received; static void set_signal_received_on_sigusr1(int sig) diff --git a/tools/testing/selftests/pidfd/pidfd_wait.c b/tools/testing/selftests/pidfd/pidfd_wait.c new file mode 100644 index 000000000000..7079f8eef792 --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_wait.c @@ -0,0 +1,271 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pidfd.h" +#include "../kselftest.h" + +#define ptr_to_u64(ptr) ((__u64)((uintptr_t)(ptr))) + +static pid_t sys_clone3(struct clone_args *args) +{ + return syscall(__NR_clone3, args, sizeof(struct clone_args)); +} + +static int sys_waitid(int which, pid_t pid, siginfo_t *info, int options, + struct rusage *ru) +{ + return syscall(__NR_waitid, which, pid, info, options, ru); +} + +static int test_pidfd_wait_simple(void) +{ + const char *test_name = "pidfd wait simple"; + int pidfd = -1, status = 0; + pid_t parent_tid = -1; + struct clone_args args = { + .parent_tid = ptr_to_u64(&parent_tid), + .pidfd = ptr_to_u64(&pidfd), + .flags = CLONE_PIDFD | CLONE_PARENT_SETTID, + .exit_signal = SIGCHLD, + }; + int ret; + pid_t pid; + siginfo_t info = { + .si_signo = 0, + }; + + pidfd = open("/proc/self", O_DIRECTORY | O_RDONLY | O_CLOEXEC); + if (pidfd < 0) + ksft_exit_fail_msg("%s test: failed to open /proc/self %s\n", + test_name, strerror(errno)); + + pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + if (pid == 0) + ksft_exit_fail_msg( + "%s test: succeeded to wait on invalid pidfd %s\n", + test_name, strerror(errno)); + close(pidfd); + pidfd = -1; + + pidfd = open("/dev/null", O_RDONLY | O_CLOEXEC); + if (pidfd == 0) + ksft_exit_fail_msg("%s test: failed to open /dev/null %s\n", + test_name, strerror(errno)); + + pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + if (pid == 0) + ksft_exit_fail_msg( + "%s test: succeeded to wait on invalid pidfd %s\n", + test_name, strerror(errno)); + close(pidfd); + pidfd = -1; + + pid = sys_clone3(&args); + if (pid < 0) + ksft_exit_fail_msg("%s test: failed to create new process %s\n", + test_name, strerror(errno)); + + if (pid == 0) + exit(EXIT_SUCCESS); + + pid = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + if (pid < 0) + ksft_exit_fail_msg( + "%s test: failed to wait on process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + if (!WIFEXITED(info.si_status) || WEXITSTATUS(info.si_status)) + ksft_exit_fail_msg( + "%s test: unexpected status received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + close(pidfd); + + if (info.si_signo != SIGCHLD) + ksft_exit_fail_msg( + "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_signo, parent_tid, pidfd, + strerror(errno)); + + if (info.si_code != CLD_EXITED) + ksft_exit_fail_msg( + "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_code, parent_tid, pidfd, + strerror(errno)); + + if (info.si_pid != parent_tid) + ksft_exit_fail_msg( + "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_pid, parent_tid, pidfd, + strerror(errno)); + + ksft_test_result_pass("%s test: Passed\n", test_name); + return 0; +} + +static int test_pidfd_wait_states(void) +{ + const char *test_name = "pidfd wait states"; + int pidfd = -1, status = 0; + pid_t parent_tid = -1; + struct clone_args args = { + .parent_tid = ptr_to_u64(&parent_tid), + .pidfd = ptr_to_u64(&pidfd), + .flags = CLONE_PIDFD | CLONE_PARENT_SETTID, + .exit_signal = SIGCHLD, + }; + int ret; + pid_t pid; + siginfo_t info = { + .si_signo = 0, + }; + + pid = sys_clone3(&args); + if (pid < 0) + ksft_exit_fail_msg("%s test: failed to create new process %s\n", + test_name, strerror(errno)); + + if (pid == 0) { + kill(getpid(), SIGSTOP); + kill(getpid(), SIGSTOP); + exit(EXIT_SUCCESS); + } + + ret = sys_waitid(P_PIDFD, pidfd, &info, WSTOPPED, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to wait on WSTOPPED process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + if (info.si_signo != SIGCHLD) + ksft_exit_fail_msg( + "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_signo, parent_tid, pidfd, + strerror(errno)); + + if (info.si_code != CLD_STOPPED) + ksft_exit_fail_msg( + "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_code, parent_tid, pidfd, + strerror(errno)); + + if (info.si_pid != parent_tid) + ksft_exit_fail_msg( + "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_pid, parent_tid, pidfd, + strerror(errno)); + + ret = sys_pidfd_send_signal(pidfd, SIGCONT, NULL, 0); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to send signal to process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + ret = sys_waitid(P_PIDFD, pidfd, &info, WCONTINUED, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to wait WCONTINUED on process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + if (info.si_signo != SIGCHLD) + ksft_exit_fail_msg( + "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_signo, parent_tid, pidfd, + strerror(errno)); + + if (info.si_code != CLD_CONTINUED) + ksft_exit_fail_msg( + "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_code, parent_tid, pidfd, + strerror(errno)); + + if (info.si_pid != parent_tid) + ksft_exit_fail_msg( + "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_pid, parent_tid, pidfd, + strerror(errno)); + + ret = sys_waitid(P_PIDFD, pidfd, &info, WUNTRACED, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to wait on WUNTRACED process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + if (info.si_signo != SIGCHLD) + ksft_exit_fail_msg( + "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_signo, parent_tid, pidfd, + strerror(errno)); + + if (info.si_code != CLD_STOPPED) + ksft_exit_fail_msg( + "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_code, parent_tid, pidfd, + strerror(errno)); + + if (info.si_pid != parent_tid) + ksft_exit_fail_msg( + "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_pid, parent_tid, pidfd, + strerror(errno)); + + ret = sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to send SIGKILL to process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + ret = sys_waitid(P_PIDFD, pidfd, &info, WEXITED, NULL); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: failed to wait on WEXITED process with pid %d and pidfd %d: %s\n", + test_name, parent_tid, pidfd, strerror(errno)); + + if (info.si_signo != SIGCHLD) + ksft_exit_fail_msg( + "%s test: unexpected si_signo value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_signo, parent_tid, pidfd, + strerror(errno)); + + if (info.si_code != CLD_KILLED) + ksft_exit_fail_msg( + "%s test: unexpected si_code value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_code, parent_tid, pidfd, + strerror(errno)); + + if (info.si_pid != parent_tid) + ksft_exit_fail_msg( + "%s test: unexpected si_pid value %d received after waiting on process with pid %d and pidfd %d: %s\n", + test_name, info.si_pid, parent_tid, pidfd, + strerror(errno)); + + close(pidfd); + + ksft_test_result_pass("%s test: Passed\n", test_name); + return 0; +} + +int main(int argc, char **argv) +{ + ksft_print_header(); + ksft_set_plan(2); + + test_pidfd_wait_simple(); + test_pidfd_wait_states(); + + return ksft_exit_pass(); +} -- cgit v1.2.3-59-g8ed1b From 2ec2f99abd2c75b507410c5def731fe1b483271b Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Fri, 26 Jul 2019 09:22:25 -0700 Subject: tests: move common definitions and functions into pidfd.h Move definitions and functions used across different pidfd tests into pidfd.h header. Signed-off-by: Suren Baghdasaryan Reviewed-by: Christian Brauner Link: https://lore.kernel.org/r/20190726162226.252750-1-surenb@google.com Signed-off-by: Christian Brauner --- tools/testing/selftests/pidfd/pidfd.h | 5 +++++ tools/testing/selftests/pidfd/pidfd_open_test.c | 5 ----- 2 files changed, 5 insertions(+), 5 deletions(-) (limited to 'tools/testing/selftests/pidfd') diff --git a/tools/testing/selftests/pidfd/pidfd.h b/tools/testing/selftests/pidfd/pidfd.h index 7d7d0ca05e0b..c6bc68329f4b 100644 --- a/tools/testing/selftests/pidfd/pidfd.h +++ b/tools/testing/selftests/pidfd/pidfd.h @@ -73,6 +73,11 @@ again: return WEXITSTATUS(status); } +static inline int sys_pidfd_open(pid_t pid, unsigned int flags) +{ + return syscall(__NR_pidfd_open, pid, flags); +} + static inline int sys_pidfd_send_signal(int pidfd, int sig, siginfo_t *info, unsigned int flags) { diff --git a/tools/testing/selftests/pidfd/pidfd_open_test.c b/tools/testing/selftests/pidfd/pidfd_open_test.c index 0377133dd6dc..b9fe75fc3e51 100644 --- a/tools/testing/selftests/pidfd/pidfd_open_test.c +++ b/tools/testing/selftests/pidfd/pidfd_open_test.c @@ -22,11 +22,6 @@ #include "pidfd.h" #include "../kselftest.h" -static inline int sys_pidfd_open(pid_t pid, unsigned int flags) -{ - return syscall(__NR_pidfd_open, pid, flags); -} - static int safe_int(const char *numstr, int *converted) { char *err = NULL; -- cgit v1.2.3-59-g8ed1b From aed5a8df3dbbd804409d40f821e0768891cfd5ab Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Fri, 26 Jul 2019 09:22:26 -0700 Subject: tests: add pidfd poll tests This adds testing for polling on pidfd of a process being killed. Test runs 10000 iterations by default to stress test pidfd polling functionality. It accepts an optional command-line parameter to override the number or iterations to run. Specifically, it tests for: - pidfd_open on a child process succeeds - pidfd_send_signal on a child process succeeds - polling on pidfd succeeds and returns exactly one event - returned event is POLLIN - event is received within 3 secs of the process being killed 10000 iterations was chosen because of the race condition being tested which is not consistently reproducible but usually is revealed after less than 2000 iterations. Reveals race fixed by commit b191d6491be6 ("pidfd: fix a poll race when setting exit_state") Signed-off-by: Suren Baghdasaryan Link: https://lore.kernel.org/r/20190726162226.252750-2-surenb@google.com Signed-off-by: Christian Brauner --- tools/testing/selftests/pidfd/.gitignore | 1 + tools/testing/selftests/pidfd/Makefile | 2 +- tools/testing/selftests/pidfd/pidfd_poll_test.c | 117 ++++++++++++++++++++++++ 3 files changed, 119 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/pidfd/pidfd_poll_test.c (limited to 'tools/testing/selftests/pidfd') diff --git a/tools/testing/selftests/pidfd/.gitignore b/tools/testing/selftests/pidfd/.gitignore index 730ef9dc08cc..8d069490e17b 100644 --- a/tools/testing/selftests/pidfd/.gitignore +++ b/tools/testing/selftests/pidfd/.gitignore @@ -1,3 +1,4 @@ pidfd_open_test +pidfd_poll_test pidfd_test pidfd_wait diff --git a/tools/testing/selftests/pidfd/Makefile b/tools/testing/selftests/pidfd/Makefile index 7c97e890f353..464c9b76148f 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/ -lpthread -TEST_GEN_PROGS := pidfd_test pidfd_open_test pidfd_wait +TEST_GEN_PROGS := pidfd_test pidfd_open_test pidfd_poll_test pidfd_wait include ../lib.mk diff --git a/tools/testing/selftests/pidfd/pidfd_poll_test.c b/tools/testing/selftests/pidfd/pidfd_poll_test.c new file mode 100644 index 000000000000..4b115444dfe9 --- /dev/null +++ b/tools/testing/selftests/pidfd/pidfd_poll_test.c @@ -0,0 +1,117 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "pidfd.h" +#include "../kselftest.h" + +static bool timeout; + +static void handle_alarm(int sig) +{ + timeout = true; +} + +int main(int argc, char **argv) +{ + struct pollfd fds; + int iter, nevents; + int nr_iterations = 10000; + + fds.events = POLLIN; + + if (argc > 2) + ksft_exit_fail_msg("Unexpected command line argument\n"); + + if (argc == 2) { + nr_iterations = atoi(argv[1]); + if (nr_iterations <= 0) + ksft_exit_fail_msg("invalid input parameter %s\n", + argv[1]); + } + + ksft_print_msg("running pidfd poll test for %d iterations\n", + nr_iterations); + + for (iter = 0; iter < nr_iterations; iter++) { + int pidfd; + int child_pid = fork(); + + if (child_pid < 0) { + if (errno == EAGAIN) { + iter--; + continue; + } + ksft_exit_fail_msg( + "%s - failed to fork a child process\n", + strerror(errno)); + } + + if (child_pid == 0) { + /* Child process just sleeps for a min and exits */ + sleep(60); + exit(EXIT_SUCCESS); + } + + /* Parent kills the child and waits for its death */ + pidfd = sys_pidfd_open(child_pid, 0); + if (pidfd < 0) + ksft_exit_fail_msg("%s - pidfd_open failed\n", + strerror(errno)); + + /* Setup 3 sec alarm - plenty of time */ + if (signal(SIGALRM, handle_alarm) == SIG_ERR) + ksft_exit_fail_msg("%s - signal failed\n", + strerror(errno)); + alarm(3); + + /* Send SIGKILL to the child */ + if (sys_pidfd_send_signal(pidfd, SIGKILL, NULL, 0)) + ksft_exit_fail_msg("%s - pidfd_send_signal failed\n", + strerror(errno)); + + /* Wait for the death notification */ + fds.fd = pidfd; + nevents = poll(&fds, 1, -1); + + /* Check for error conditions */ + if (nevents < 0) + ksft_exit_fail_msg("%s - poll failed\n", + strerror(errno)); + + if (nevents != 1) + ksft_exit_fail_msg("unexpected poll result: %d\n", + nevents); + + if (!(fds.revents & POLLIN)) + ksft_exit_fail_msg( + "unexpected event type received: 0x%x\n", + fds.revents); + + if (timeout) + ksft_exit_fail_msg( + "death notification wait timeout\n"); + + close(pidfd); + /* Wait for child to prevent zombies */ + if (waitpid(child_pid, NULL, 0) < 0) + ksft_exit_fail_msg("%s - waitpid failed\n", + strerror(errno)); + + } + + ksft_test_result_pass("pidfd poll test: pass\n"); + return ksft_exit_pass(); +} -- cgit v1.2.3-59-g8ed1b