From 5bd3cf8cbc8a286308ef3f40656659d5abc89995 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 13 Dec 2023 17:11:03 +0100 Subject: [PATCH] add selftest for statmount/listmount Initial selftest for the new statmount() and listmount() syscalls. Signed-off-by: Miklos Szeredi Link: https://lore.kernel.org/r/20231213161104.403171-1-mszeredi@redhat.com Signed-off-by: Christian Brauner --- tools/testing/selftests/Makefile | 1 + .../filesystems/statmount/.gitignore | 2 + .../selftests/filesystems/statmount/Makefile | 6 + .../filesystems/statmount/statmount_test.c | 612 ++++++++++++++++++ 4 files changed, 621 insertions(+) create mode 100644 tools/testing/selftests/filesystems/statmount/.gitignore create mode 100644 tools/testing/selftests/filesystems/statmount/Makefile create mode 100644 tools/testing/selftests/filesystems/statmount/statmount_test.c diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 3b2061d1c1a5..da2e1b0e4dd8 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -26,6 +26,7 @@ TARGETS += filesystems TARGETS += filesystems/binderfs TARGETS += filesystems/epoll TARGETS += filesystems/fat +TARGETS += filesystems/statmount TARGETS += firmware TARGETS += fpu TARGETS += ftrace diff --git a/tools/testing/selftests/filesystems/statmount/.gitignore b/tools/testing/selftests/filesystems/statmount/.gitignore new file mode 100644 index 000000000000..82a4846cbc4b --- /dev/null +++ b/tools/testing/selftests/filesystems/statmount/.gitignore @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0-only +/*_test diff --git a/tools/testing/selftests/filesystems/statmount/Makefile b/tools/testing/selftests/filesystems/statmount/Makefile new file mode 100644 index 000000000000..07a0d5b545ca --- /dev/null +++ b/tools/testing/selftests/filesystems/statmount/Makefile @@ -0,0 +1,6 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +CFLAGS += -Wall -O2 -g $(KHDR_INCLUDES) +TEST_GEN_PROGS := statmount_test + +include ../../lib.mk diff --git a/tools/testing/selftests/filesystems/statmount/statmount_test.c b/tools/testing/selftests/filesystems/statmount/statmount_test.c new file mode 100644 index 000000000000..3eafd7da58e2 --- /dev/null +++ b/tools/testing/selftests/filesystems/statmount/statmount_test.c @@ -0,0 +1,612 @@ +// SPDX-License-Identifier: GPL-2.0-or-later + +#define _GNU_SOURCE + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "../../kselftest.h" + +static const char *const known_fs[] = { + "9p", "adfs", "affs", "afs", "aio", "anon_inodefs", "apparmorfs", + "autofs", "bcachefs", "bdev", "befs", "bfs", "binder", "binfmt_misc", + "bpf", "btrfs", "btrfs_test_fs", "ceph", "cgroup", "cgroup2", "cifs", + "coda", "configfs", "cpuset", "cramfs", "cxl", "dax", "debugfs", + "devpts", "devtmpfs", "dmabuf", "drm", "ecryptfs", "efivarfs", "efs", + "erofs", "exfat", "ext2", "ext3", "ext4", "f2fs", "functionfs", + "fuse", "fuseblk", "fusectl", "gadgetfs", "gfs2", "gfs2meta", "hfs", + "hfsplus", "hostfs", "hpfs", "hugetlbfs", "ibmasmfs", "iomem", + "ipathfs", "iso9660", "jffs2", "jfs", "minix", "mqueue", "msdos", + "nfs", "nfs4", "nfsd", "nilfs2", "nsfs", "ntfs", "ntfs3", "ocfs2", + "ocfs2_dlmfs", "ocxlflash", "omfs", "openpromfs", "overlay", "pipefs", + "proc", "pstore", "pvfs2", "qnx4", "qnx6", "ramfs", "reiserfs", + "resctrl", "romfs", "rootfs", "rpc_pipefs", "s390_hypfs", "secretmem", + "securityfs", "selinuxfs", "smackfs", "smb3", "sockfs", "spufs", + "squashfs", "sysfs", "sysv", "tmpfs", "tracefs", "ubifs", "udf", + "ufs", "v7", "vboxsf", "vfat", "virtiofs", "vxfs", "xenfs", "xfs", + "zonefs", NULL }; + +static int statmount(uint64_t mnt_id, uint64_t mask, struct statmount *buf, + size_t bufsize, unsigned int flags) +{ + struct mnt_id_req req = { + .size = MNT_ID_REQ_SIZE_VER0, + .mnt_id = mnt_id, + .param = mask, + }; + + return syscall(__NR_statmount, &req, buf, bufsize, flags); +} + +static struct statmount *statmount_alloc(uint64_t mnt_id, uint64_t mask, unsigned int flags) +{ + size_t bufsize = 1 << 15; + struct statmount *buf = NULL, *tmp = alloca(bufsize); + int tofree = 0; + int ret; + + for (;;) { + ret = statmount(mnt_id, mask, tmp, bufsize, flags); + if (ret != -1) + break; + if (tofree) + free(tmp); + if (errno != EOVERFLOW) + return NULL; + bufsize <<= 1; + tofree = 1; + tmp = malloc(bufsize); + if (!tmp) + return NULL; + } + buf = malloc(tmp->size); + if (buf) + memcpy(buf, tmp, tmp->size); + if (tofree) + free(tmp); + + return buf; +} + +static void write_file(const char *path, const char *val) +{ + int fd = open(path, O_WRONLY); + size_t len = strlen(val); + int ret; + + if (fd == -1) + ksft_exit_fail_msg("opening %s for write: %s\n", path, strerror(errno)); + + ret = write(fd, val, len); + if (ret == -1) + ksft_exit_fail_msg("writing to %s: %s\n", path, strerror(errno)); + if (ret != len) + ksft_exit_fail_msg("short write to %s\n", path); + + ret = close(fd); + if (ret == -1) + ksft_exit_fail_msg("closing %s\n", path); +} + +static uint64_t get_mnt_id(const char *name, const char *path, uint64_t mask) +{ + struct statx sx; + int ret; + + ret = statx(AT_FDCWD, path, 0, mask, &sx); + if (ret == -1) + ksft_exit_fail_msg("retrieving %s mount ID for %s: %s\n", + mask & STATX_MNT_ID_UNIQUE ? "unique" : "old", + name, strerror(errno)); + if (!(sx.stx_mask & mask)) + ksft_exit_fail_msg("no %s mount ID available for %s\n", + mask & STATX_MNT_ID_UNIQUE ? "unique" : "old", + name); + + return sx.stx_mnt_id; +} + + +static char root_mntpoint[] = "/tmp/statmount_test_root.XXXXXX"; +static int orig_root; +static uint64_t root_id, parent_id; +static uint32_t old_root_id, old_parent_id; + + +static void cleanup_namespace(void) +{ + fchdir(orig_root); + chroot("."); + umount2(root_mntpoint, MNT_DETACH); + rmdir(root_mntpoint); +} + +static void setup_namespace(void) +{ + int ret; + char buf[32]; + uid_t uid = getuid(); + gid_t gid = getgid(); + + ret = unshare(CLONE_NEWNS|CLONE_NEWUSER); + if (ret == -1) + ksft_exit_fail_msg("unsharing mountns and userns: %s\n", + strerror(errno)); + + sprintf(buf, "0 %d 1", uid); + write_file("/proc/self/uid_map", buf); + write_file("/proc/self/setgroups", "deny"); + sprintf(buf, "0 %d 1", gid); + write_file("/proc/self/gid_map", buf); + + ret = mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL); + if (ret == -1) + ksft_exit_fail_msg("making mount tree private: %s\n", + strerror(errno)); + + if (!mkdtemp(root_mntpoint)) + ksft_exit_fail_msg("creating temporary directory %s: %s\n", + root_mntpoint, strerror(errno)); + + old_parent_id = get_mnt_id("parent", root_mntpoint, STATX_MNT_ID); + parent_id = get_mnt_id("parent", root_mntpoint, STATX_MNT_ID_UNIQUE); + + orig_root = open("/", O_PATH); + if (orig_root == -1) + ksft_exit_fail_msg("opening root directory: %s", + strerror(errno)); + + atexit(cleanup_namespace); + + ret = mount(root_mntpoint, root_mntpoint, NULL, MS_BIND, NULL); + if (ret == -1) + ksft_exit_fail_msg("mounting temp root %s: %s\n", + root_mntpoint, strerror(errno)); + + ret = chroot(root_mntpoint); + if (ret == -1) + ksft_exit_fail_msg("chroot to temp root %s: %s\n", + root_mntpoint, strerror(errno)); + + ret = chdir("/"); + if (ret == -1) + ksft_exit_fail_msg("chdir to root: %s\n", strerror(errno)); + + old_root_id = get_mnt_id("root", "/", STATX_MNT_ID); + root_id = get_mnt_id("root", "/", STATX_MNT_ID_UNIQUE); +} + +static int setup_mount_tree(int log2_num) +{ + int ret, i; + + ret = mount("", "/", NULL, MS_REC|MS_SHARED, NULL); + if (ret == -1) { + ksft_test_result_fail("making mount tree shared: %s\n", + strerror(errno)); + return -1; + } + + for (i = 0; i < log2_num; i++) { + ret = mount("/", "/", NULL, MS_BIND, NULL); + if (ret == -1) { + ksft_test_result_fail("mounting submount %s: %s\n", + root_mntpoint, strerror(errno)); + return -1; + } + } + return 0; +} + +static ssize_t listmount(uint64_t mnt_id, uint64_t last_mnt_id, + uint64_t list[], size_t num, unsigned int flags) +{ + struct mnt_id_req req = { + .size = MNT_ID_REQ_SIZE_VER0, + .mnt_id = mnt_id, + .param = last_mnt_id, + }; + + return syscall(__NR_listmount, &req, list, num, flags); +} + +static void test_listmount_empty_root(void) +{ + ssize_t res; + const unsigned int size = 32; + uint64_t list[size]; + + res = listmount(LSMT_ROOT, 0, list, size, 0); + if (res == -1) { + ksft_test_result_fail("listmount: %s\n", strerror(errno)); + return; + } + if (res != 1) { + ksft_test_result_fail("listmount result is %zi != 1\n", res); + return; + } + + if (list[0] != root_id) { + ksft_test_result_fail("listmount ID doesn't match 0x%llx != 0x%llx\n", + (unsigned long long) list[0], + (unsigned long long) root_id); + return; + } + + ksft_test_result_pass("listmount empty root\n"); +} + +static void test_statmount_zero_mask(void) +{ + struct statmount sm; + int ret; + + ret = statmount(root_id, 0, &sm, sizeof(sm), 0); + if (ret == -1) { + ksft_test_result_fail("statmount zero mask: %s\n", + strerror(errno)); + return; + } + if (sm.size != sizeof(sm)) { + ksft_test_result_fail("unexpected size: %u != %u\n", + sm.size, (uint32_t) sizeof(sm)); + return; + } + if (sm.mask != 0) { + ksft_test_result_fail("unexpected mask: 0x%llx != 0x0\n", + (unsigned long long) sm.mask); + return; + } + + ksft_test_result_pass("statmount zero mask\n"); +} + +static void test_statmount_mnt_basic(void) +{ + struct statmount sm; + int ret; + uint64_t mask = STATMOUNT_MNT_BASIC; + + ret = statmount(root_id, mask, &sm, sizeof(sm), 0); + if (ret == -1) { + ksft_test_result_fail("statmount mnt basic: %s\n", + strerror(errno)); + return; + } + if (sm.size != sizeof(sm)) { + ksft_test_result_fail("unexpected size: %u != %u\n", + sm.size, (uint32_t) sizeof(sm)); + return; + } + if (sm.mask != mask) { + ksft_test_result_skip("statmount mnt basic unavailable\n"); + return; + } + + if (sm.mnt_id != root_id) { + ksft_test_result_fail("unexpected root ID: 0x%llx != 0x%llx\n", + (unsigned long long) sm.mnt_id, + (unsigned long long) root_id); + return; + } + + if (sm.mnt_id_old != old_root_id) { + ksft_test_result_fail("unexpected old root ID: %u != %u\n", + sm.mnt_id_old, old_root_id); + return; + } + + if (sm.mnt_parent_id != parent_id) { + ksft_test_result_fail("unexpected parent ID: 0x%llx != 0x%llx\n", + (unsigned long long) sm.mnt_parent_id, + (unsigned long long) parent_id); + return; + } + + if (sm.mnt_parent_id_old != old_parent_id) { + ksft_test_result_fail("unexpected old parent ID: %u != %u\n", + sm.mnt_parent_id_old, old_parent_id); + return; + } + + if (sm.mnt_propagation != MS_PRIVATE) { + ksft_test_result_fail("unexpected propagation: 0x%llx\n", + (unsigned long long) sm.mnt_propagation); + return; + } + + ksft_test_result_pass("statmount mnt basic\n"); +} + + +static void test_statmount_sb_basic(void) +{ + struct statmount sm; + int ret; + uint64_t mask = STATMOUNT_SB_BASIC; + struct statx sx; + struct statfs sf; + + ret = statmount(root_id, mask, &sm, sizeof(sm), 0); + if (ret == -1) { + ksft_test_result_fail("statmount sb basic: %s\n", + strerror(errno)); + return; + } + if (sm.size != sizeof(sm)) { + ksft_test_result_fail("unexpected size: %u != %u\n", + sm.size, (uint32_t) sizeof(sm)); + return; + } + if (sm.mask != mask) { + ksft_test_result_skip("statmount sb basic unavailable\n"); + return; + } + + ret = statx(AT_FDCWD, "/", 0, 0, &sx); + if (ret == -1) { + ksft_test_result_fail("stat root failed: %s\n", + strerror(errno)); + return; + } + + if (sm.sb_dev_major != sx.stx_dev_major || + sm.sb_dev_minor != sx.stx_dev_minor) { + ksft_test_result_fail("unexpected sb dev %u:%u != %u:%u\n", + sm.sb_dev_major, sm.sb_dev_minor, + sx.stx_dev_major, sx.stx_dev_minor); + return; + } + + ret = statfs("/", &sf); + if (ret == -1) { + ksft_test_result_fail("statfs root failed: %s\n", + strerror(errno)); + return; + } + + if (sm.sb_magic != sf.f_type) { + ksft_test_result_fail("unexpected sb magic: 0x%llx != 0x%lx\n", + (unsigned long long) sm.sb_magic, + sf.f_type); + return; + } + + ksft_test_result_pass("statmount sb basic\n"); +} + +static void test_statmount_mnt_point(void) +{ + struct statmount *sm; + + sm = statmount_alloc(root_id, STATMOUNT_MNT_POINT, 0); + if (!sm) { + ksft_test_result_fail("statmount mount point: %s\n", + strerror(errno)); + return; + } + + if (strcmp(sm->str + sm->mnt_point, "/") != 0) { + ksft_test_result_fail("unexpected mount point: '%s' != '/'\n", + sm->str + sm->mnt_point); + goto out; + } + ksft_test_result_pass("statmount mount point\n"); +out: + free(sm); +} + +static void test_statmount_mnt_root(void) +{ + struct statmount *sm; + const char *mnt_root, *last_dir, *last_root; + + last_dir = strrchr(root_mntpoint, '/'); + assert(last_dir); + last_dir++; + + sm = statmount_alloc(root_id, STATMOUNT_MNT_ROOT, 0); + if (!sm) { + ksft_test_result_fail("statmount mount root: %s\n", + strerror(errno)); + return; + } + mnt_root = sm->str + sm->mnt_root; + last_root = strrchr(mnt_root, '/'); + if (last_root) + last_root++; + else + last_root = mnt_root; + + if (strcmp(last_dir, last_root) != 0) { + ksft_test_result_fail("unexpected mount root last component: '%s' != '%s'\n", + last_root, last_dir); + goto out; + } + ksft_test_result_pass("statmount mount root\n"); +out: + free(sm); +} + +static void test_statmount_fs_type(void) +{ + struct statmount *sm; + const char *fs_type; + const char *const *s; + + sm = statmount_alloc(root_id, STATMOUNT_FS_TYPE, 0); + if (!sm) { + ksft_test_result_fail("statmount fs type: %s\n", + strerror(errno)); + return; + } + fs_type = sm->str + sm->fs_type; + for (s = known_fs; s != NULL; s++) { + if (strcmp(fs_type, *s) == 0) + break; + } + if (!s) + ksft_print_msg("unknown filesystem type: %s\n", fs_type); + + ksft_test_result_pass("statmount fs type\n"); + free(sm); +} + +static void test_statmount_string(uint64_t mask, size_t off, const char *name) +{ + struct statmount *sm; + size_t len, shortsize, exactsize; + uint32_t start, i; + int ret; + + sm = statmount_alloc(root_id, mask, 0); + if (!sm) { + ksft_test_result_fail("statmount %s: %s\n", name, + strerror(errno)); + goto out; + } + if (sm->size < sizeof(*sm)) { + ksft_test_result_fail("unexpected size: %u < %u\n", + sm->size, (uint32_t) sizeof(*sm)); + goto out; + } + if (sm->mask != mask) { + ksft_test_result_skip("statmount %s unavailable\n", name); + goto out; + } + len = sm->size - sizeof(*sm); + start = ((uint32_t *) sm)[off]; + + for (i = start;; i++) { + if (i >= len) { + ksft_test_result_fail("string out of bounds\n"); + goto out; + } + if (!sm->str[i]) + break; + } + exactsize = sm->size; + shortsize = sizeof(*sm) + i; + + ret = statmount(root_id, mask, sm, exactsize, 0); + if (ret == -1) { + ksft_test_result_fail("statmount exact size: %s\n", + strerror(errno)); + goto out; + } + errno = 0; + ret = statmount(root_id, mask, sm, shortsize, 0); + if (ret != -1 || errno != EOVERFLOW) { + ksft_test_result_fail("should have failed with EOVERFLOW: %s\n", + strerror(errno)); + goto out; + } + + ksft_test_result_pass("statmount string %s\n", name); +out: + free(sm); +} + +static void test_listmount_tree(void) +{ + ssize_t res; + const unsigned int log2_num = 4; + const unsigned int step = 3; + const unsigned int size = (1 << log2_num) + step + 1; + size_t num, expect = 1 << log2_num; + uint64_t list[size]; + uint64_t list2[size]; + size_t i; + + + res = setup_mount_tree(log2_num); + if (res == -1) + return; + + num = res = listmount(LSMT_ROOT, 0, list, size, 0); + if (res == -1) { + ksft_test_result_fail("listmount: %s\n", strerror(errno)); + return; + } + if (num != expect) { + ksft_test_result_fail("listmount result is %zi != %zi\n", + res, expect); + return; + } + + for (i = 0; i < size - step;) { + res = listmount(LSMT_ROOT, i ? list2[i - 1] : 0, list2 + i, step, 0); + if (res == -1) + ksft_test_result_fail("short listmount: %s\n", + strerror(errno)); + i += res; + if (res < step) + break; + } + if (i != num) { + ksft_test_result_fail("different number of entries: %zu != %zu\n", + i, num); + return; + } + for (i = 0; i < num; i++) { + if (list2[i] != list[i]) { + ksft_test_result_fail("different value for entry %zu: 0x%llx != 0x%llx\n", + i, + (unsigned long long) list2[i], + (unsigned long long) list[i]); + } + } + + ksft_test_result_pass("listmount tree\n"); +} + +#define str_off(memb) (offsetof(struct statmount, memb) / sizeof(uint32_t)) + +int main(void) +{ + int ret; + uint64_t all_mask = STATMOUNT_SB_BASIC | STATMOUNT_MNT_BASIC | + STATMOUNT_PROPAGATE_FROM | STATMOUNT_MNT_ROOT | + STATMOUNT_MNT_POINT | STATMOUNT_FS_TYPE; + + ksft_print_header(); + + ret = statmount(0, 0, NULL, 0, 0); + assert(ret == -1); + if (errno == ENOSYS) + ksft_exit_skip("statmount() syscall not supported\n"); + + setup_namespace(); + + ksft_set_plan(14); + test_listmount_empty_root(); + test_statmount_zero_mask(); + test_statmount_mnt_basic(); + test_statmount_sb_basic(); + test_statmount_mnt_root(); + test_statmount_mnt_point(); + test_statmount_fs_type(); + test_statmount_string(STATMOUNT_MNT_ROOT, str_off(mnt_root), "mount root"); + test_statmount_string(STATMOUNT_MNT_POINT, str_off(mnt_point), "mount point"); + test_statmount_string(STATMOUNT_FS_TYPE, str_off(fs_type), "fs type"); + test_statmount_string(all_mask, str_off(mnt_root), "mount root & all"); + test_statmount_string(all_mask, str_off(mnt_point), "mount point & all"); + test_statmount_string(all_mask, str_off(fs_type), "fs type & all"); + + test_listmount_tree(); + + + if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0) + ksft_exit_fail(); + else + ksft_exit_pass(); +}