This adds basic tests for the new close_range() syscall. - test that no invalid flags can be passed - test that a range of file descriptors is correctly closed - test that a range of file descriptors is correctly closed if there there are already closed file descriptors in the range - test that max_fd is correctly capped to the current fdtable maximum

Signed-off-by: Christian Brauner christian.brauner@ubuntu.com Cc: Arnd Bergmann arnd@arndb.de Cc: Jann Horn jannh@google.com Cc: David Howells dhowells@redhat.com Cc: Dmitry V. Levin ldv@altlinux.org Cc: Oleg Nesterov oleg@redhat.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Florian Weimer fweimer@redhat.com Cc: Shuah Khan shuah@kernel.org Cc: linux-api@vger.kernel.org Cc: linux-kselftest@vger.kernel.org --- /* v2 */ unchanged

/* v3 */ - Christian Brauner christian@brauner.io: - verify that close_range() correctly closes a single file descriptor

/* v4 */ - Christian Brauner christian@brauner.io: - add missing Cc for Shuah - add missing Cc for linux-kselftest

/* v5 */ - Michael Ellerman mpe@ellerman.id.au: - remove include of unexported kernel headers - Christian Brauner christian.brauner@ubuntu.com: - add missing SPDX header to Makefile --- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/core/.gitignore | 1 + tools/testing/selftests/core/Makefile | 7 + .../testing/selftests/core/close_range_test.c | 149 ++++++++++++++++++ 4 files changed, 158 insertions(+) create mode 100644 tools/testing/selftests/core/.gitignore create mode 100644 tools/testing/selftests/core/Makefile create mode 100644 tools/testing/selftests/core/close_range_test.c

diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index c3feccb99ff5..b0b754b9aa62 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -4,6 +4,7 @@ TARGETS += bpf TARGETS += breakpoints TARGETS += capabilities TARGETS += cgroup +TARGETS += core TARGETS += cpufreq TARGETS += cpu-hotplug TARGETS += drivers/dma-buf diff --git a/tools/testing/selftests/core/.gitignore b/tools/testing/selftests/core/.gitignore new file mode 100644 index 000000000000..6e6712ce5817 --- /dev/null +++ b/tools/testing/selftests/core/.gitignore @@ -0,0 +1 @@ +close_range_test diff --git a/tools/testing/selftests/core/Makefile b/tools/testing/selftests/core/Makefile new file mode 100644 index 000000000000..f6f2d6f473c6 --- /dev/null +++ b/tools/testing/selftests/core/Makefile @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: GPL-2.0-only +CFLAGS += -g -I../../../../usr/include/ + +TEST_GEN_PROGS := close_range_test + +include ../lib.mk + diff --git a/tools/testing/selftests/core/close_range_test.c b/tools/testing/selftests/core/close_range_test.c new file mode 100644 index 000000000000..6d92e239a228 --- /dev/null +++ b/tools/testing/selftests/core/close_range_test.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE +#include <errno.h> +#include <fcntl.h> +#include <linux/kernel.h> +#include <limits.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <syscall.h> +#include <unistd.h> + +#include "../kselftest.h" + +#ifndef __NR_close_range +#define __NR_close_range -1 +#endif + +static inline int sys_close_range(unsigned int fd, unsigned int max_fd, + unsigned int flags) +{ + return syscall(__NR_close_range, fd, max_fd, flags); +} + +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#endif + +int main(int argc, char **argv) +{ + const char *test_name = "close_range"; + int i, ret; + int open_fds[101]; + int fd_max, fd_mid, fd_min; + + ksft_set_plan(9); + + for (i = 0; i < ARRAY_SIZE(open_fds); i++) { + int fd; + + fd = open("/dev/null", O_RDONLY | O_CLOEXEC); + if (fd < 0) { + if (errno == ENOENT) + ksft_exit_skip( + "%s test: skipping test since /dev/null does not exist\n", + test_name); + + ksft_exit_fail_msg( + "%s test: %s - failed to open /dev/null\n", + strerror(errno), test_name); + } + + open_fds[i] = fd; + } + + fd_min = open_fds[0]; + fd_max = open_fds[99]; + + ret = sys_close_range(fd_min, fd_max, 1); + if (!ret) + ksft_exit_fail_msg( + "%s test: managed to pass invalid flag value\n", + test_name); + if (errno == ENOSYS) + ksft_exit_skip("%s test: close_range() syscall not supported\n", test_name); + + ksft_test_result_pass("do not allow invalid flag values for close_range()\n"); + + fd_mid = open_fds[50]; + ret = sys_close_range(fd_min, fd_mid, 0); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: Failed to close range of file descriptors from %d to %d\n", + test_name, fd_min, fd_mid); + ksft_test_result_pass("close_range() from %d to %d\n", fd_min, fd_mid); + + for (i = 0; i <= 50; i++) { + ret = fcntl(open_fds[i], F_GETFL); + if (ret >= 0) + ksft_exit_fail_msg( + "%s test: Failed to close range of file descriptors from %d to %d\n", + test_name, fd_min, fd_mid); + } + ksft_test_result_pass("fcntl() verify closed range from %d to %d\n", fd_min, fd_mid); + + /* create a couple of gaps */ + close(57); + close(78); + close(81); + close(82); + close(84); + close(90); + + fd_mid = open_fds[51]; + /* Choose slightly lower limit and leave some fds for a later test */ + fd_max = open_fds[92]; + ret = sys_close_range(fd_mid, fd_max, 0); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: Failed to close range of file descriptors from 51 to 100\n", + test_name); + ksft_test_result_pass("close_range() from %d to %d\n", fd_mid, fd_max); + + for (i = 51; i <= 92; i++) { + ret = fcntl(open_fds[i], F_GETFL); + if (ret >= 0) + ksft_exit_fail_msg( + "%s test: Failed to close range of file descriptors from 51 to 100\n", + test_name); + } + ksft_test_result_pass("fcntl() verify closed range from %d to %d\n", fd_mid, fd_max); + + fd_mid = open_fds[93]; + fd_max = open_fds[99]; + /* test that the kernel caps and still closes all fds */ + ret = sys_close_range(fd_mid, UINT_MAX, 0); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: Failed to close range of file descriptors from 51 to 100\n", + test_name); + ksft_test_result_pass("close_range() from %d to %d\n", fd_mid, fd_max); + + for (i = 93; i < 100; i++) { + ret = fcntl(open_fds[i], F_GETFL); + if (ret >= 0) + ksft_exit_fail_msg( + "%s test: Failed to close range of file descriptors from 51 to 100\n", + test_name); + } + ksft_test_result_pass("fcntl() verify closed range from %d to %d\n", fd_mid, fd_max); + + ret = sys_close_range(open_fds[100], open_fds[100], 0); + if (ret < 0) + ksft_exit_fail_msg( + "%s test: Failed to close single file descriptor\n", + test_name); + ksft_test_result_pass("close_range() closed single file descriptor\n"); + + ret = fcntl(open_fds[100], F_GETFL); + if (ret >= 0) + ksft_exit_fail_msg( + "%s test: Failed to close single file descriptor\n", + test_name); + ksft_test_result_pass("fcntl() verify closed single file descriptor\n"); + + return ksft_exit_pass(); +}