]> git.ipfire.org Git - thirdparty/linux.git/commitdiff
selftests: add a test for the foreign mnt ns extensions
authorJosef Bacik <josef@toxicpanda.com>
Mon, 24 Jun 2024 15:49:51 +0000 (11:49 -0400)
committerChristian Brauner <brauner@kernel.org>
Fri, 28 Jun 2024 12:36:42 +0000 (14:36 +0200)
This tests both statmount and listmount to make sure they work with the
extensions that allow us to specify a mount ns to enter in order to find
the mount entries.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/2d1a35bc9ab94b4656c056c420f25e429e7eb0b1.1719243756.git.josef@toxicpanda.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
tools/testing/selftests/filesystems/statmount/Makefile
tools/testing/selftests/filesystems/statmount/statmount.h [new file with mode: 0644]
tools/testing/selftests/filesystems/statmount/statmount_test.c
tools/testing/selftests/filesystems/statmount/statmount_test_ns.c [new file with mode: 0644]

index 07a0d5b545ca9aa9c5c750ccb059f71521d5118d..3af3136e35a4bc3671c292ab6abe41832a2be85d 100644 (file)
@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0-or-later
 
 CFLAGS += -Wall -O2 -g $(KHDR_INCLUDES)
-TEST_GEN_PROGS := statmount_test
+TEST_GEN_PROGS := statmount_test statmount_test_ns
 
 include ../../lib.mk
diff --git a/tools/testing/selftests/filesystems/statmount/statmount.h b/tools/testing/selftests/filesystems/statmount/statmount.h
new file mode 100644 (file)
index 0000000..f4294ba
--- /dev/null
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __STATMOUNT_H
+#define __STATMOUNT_H
+
+#include <stdint.h>
+#include <linux/mount.h>
+#include <asm/unistd.h>
+
+static inline int statmount(uint64_t mnt_id, uint64_t mnt_ns_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,
+       };
+
+       if (mnt_ns_id) {
+               req.size = MNT_ID_REQ_SIZE_VER1;
+               req.mnt_ns_id = mnt_ns_id;
+       }
+
+       return syscall(__NR_statmount, &req, buf, bufsize, flags);
+}
+
+static ssize_t listmount(uint64_t mnt_id, uint64_t mnt_ns_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,
+       };
+
+       if (mnt_ns_id) {
+               req.size = MNT_ID_REQ_SIZE_VER1;
+               req.mnt_ns_id = mnt_ns_id;
+       }
+
+       return syscall(__NR_listmount, &req, list, num, flags);
+}
+
+#endif /* __STATMOUNT_H */
index e6d7c4f1c85b50503c90056cae2d537b80710dd0..4f7023c2de772c28debe15712ddc3189cd3e6c3c 100644 (file)
@@ -4,17 +4,15 @@
 
 #include <assert.h>
 #include <stddef.h>
-#include <stdint.h>
 #include <sched.h>
 #include <fcntl.h>
 #include <sys/param.h>
 #include <sys/mount.h>
 #include <sys/stat.h>
 #include <sys/statfs.h>
-#include <linux/mount.h>
 #include <linux/stat.h>
-#include <asm/unistd.h>
 
+#include "statmount.h"
 #include "../../kselftest.h"
 
 static const char *const known_fs[] = {
@@ -36,18 +34,6 @@ static const char *const known_fs[] = {
        "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;
@@ -56,7 +42,7 @@ static struct statmount *statmount_alloc(uint64_t mnt_id, uint64_t mask, unsigne
        int ret;
 
        for (;;) {
-               ret = statmount(mnt_id, mask, tmp, bufsize, flags);
+               ret = statmount(mnt_id, 0, mask, tmp, bufsize, flags);
                if (ret != -1)
                        break;
                if (tofree)
@@ -122,7 +108,6 @@ 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);
@@ -138,7 +123,7 @@ static void setup_namespace(void)
        uid_t uid = getuid();
        gid_t gid = getgid();
 
-       ret = unshare(CLONE_NEWNS|CLONE_NEWUSER);
+       ret = unshare(CLONE_NEWNS|CLONE_NEWUSER|CLONE_NEWPID);
        if (ret == -1)
                ksft_exit_fail_msg("unsharing mountns and userns: %s\n",
                                   strerror(errno));
@@ -208,25 +193,13 @@ static int setup_mount_tree(int log2_num)
        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);
+       res = listmount(LSMT_ROOT, 0, 0, list, size, 0);
        if (res == -1) {
                ksft_test_result_fail("listmount: %s\n", strerror(errno));
                return;
@@ -251,7 +224,7 @@ static void test_statmount_zero_mask(void)
        struct statmount sm;
        int ret;
 
-       ret = statmount(root_id, 0, &sm, sizeof(sm), 0);
+       ret = statmount(root_id, 0, 0, &sm, sizeof(sm), 0);
        if (ret == -1) {
                ksft_test_result_fail("statmount zero mask: %s\n",
                                      strerror(errno));
@@ -277,7 +250,7 @@ static void test_statmount_mnt_basic(void)
        int ret;
        uint64_t mask = STATMOUNT_MNT_BASIC;
 
-       ret = statmount(root_id, mask, &sm, sizeof(sm), 0);
+       ret = statmount(root_id, 0, mask, &sm, sizeof(sm), 0);
        if (ret == -1) {
                ksft_test_result_fail("statmount mnt basic: %s\n",
                                      strerror(errno));
@@ -337,7 +310,7 @@ static void test_statmount_sb_basic(void)
        struct statx sx;
        struct statfs sf;
 
-       ret = statmount(root_id, mask, &sm, sizeof(sm), 0);
+       ret = statmount(root_id, 0, mask, &sm, sizeof(sm), 0);
        if (ret == -1) {
                ksft_test_result_fail("statmount sb basic: %s\n",
                                      strerror(errno));
@@ -498,14 +471,14 @@ static void test_statmount_string(uint64_t mask, size_t off, const char *name)
        exactsize = sm->size;
        shortsize = sizeof(*sm) + i;
 
-       ret = statmount(root_id, mask, sm, exactsize, 0);
+       ret = statmount(root_id, 0, 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);
+       ret = statmount(root_id, 0, mask, sm, shortsize, 0);
        if (ret != -1 || errno != EOVERFLOW) {
                ksft_test_result_fail("should have failed with EOVERFLOW: %s\n",
                                      strerror(errno));
@@ -533,7 +506,7 @@ static void test_listmount_tree(void)
        if (res == -1)
                return;
 
-       num = res = listmount(LSMT_ROOT, 0, list, size, 0);
+       num = res = listmount(LSMT_ROOT, 0, 0, list, size, 0);
        if (res == -1) {
                ksft_test_result_fail("listmount: %s\n", strerror(errno));
                return;
@@ -545,7 +518,7 @@ static void test_listmount_tree(void)
        }
 
        for (i = 0; i < size - step;) {
-               res = listmount(LSMT_ROOT, i ? list2[i - 1] : 0, list2 + i, step, 0);
+               res = listmount(LSMT_ROOT, 0, i ? list2[i - 1] : 0, list2 + i, step, 0);
                if (res == -1)
                        ksft_test_result_fail("short listmount: %s\n",
                                              strerror(errno));
@@ -577,11 +550,11 @@ 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;
+               STATMOUNT_MNT_POINT | STATMOUNT_FS_TYPE | STATMOUNT_MNT_NS_ID;
 
        ksft_print_header();
 
-       ret = statmount(0, 0, NULL, 0, 0);
+       ret = statmount(0, 0, 0, NULL, 0, 0);
        assert(ret == -1);
        if (errno == ENOSYS)
                ksft_exit_skip("statmount() syscall not supported\n");
diff --git a/tools/testing/selftests/filesystems/statmount/statmount_test_ns.c b/tools/testing/selftests/filesystems/statmount/statmount_test_ns.c
new file mode 100644 (file)
index 0000000..e044f5f
--- /dev/null
@@ -0,0 +1,364 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#define _GNU_SOURCE
+
+#include <assert.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <sched.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <linux/nsfs.h>
+#include <linux/stat.h>
+
+#include "statmount.h"
+#include "../../kselftest.h"
+
+#define NSID_PASS 0
+#define NSID_FAIL 1
+#define NSID_SKIP 2
+#define NSID_ERROR 3
+
+static void handle_result(int ret, const char *testname)
+{
+       if (ret == NSID_PASS)
+               ksft_test_result_pass("%s\n", testname);
+       else if (ret == NSID_FAIL)
+               ksft_test_result_fail("%s\n", testname);
+       else if (ret == NSID_ERROR)
+               ksft_exit_fail_msg("%s\n", testname);
+       else
+               ksft_test_result_skip("%s\n", testname);
+}
+
+static inline int wait_for_pid(pid_t pid)
+{
+       int status, ret;
+
+again:
+       ret = waitpid(pid, &status, 0);
+       if (ret == -1) {
+               if (errno == EINTR)
+                       goto again;
+
+               ksft_print_msg("waitpid returned -1, errno=%d\n", errno);
+               return -1;
+       }
+
+       if (!WIFEXITED(status)) {
+               ksft_print_msg(
+                      "waitpid !WIFEXITED, WIFSIGNALED=%d, WTERMSIG=%d\n",
+                      WIFSIGNALED(status), WTERMSIG(status));
+               return -1;
+       }
+
+       ret = WEXITSTATUS(status);
+       return ret;
+}
+
+static int get_mnt_ns_id(const char *mnt_ns, uint64_t *mnt_ns_id)
+{
+       int fd = open(mnt_ns, O_RDONLY);
+
+       if (fd < 0) {
+               ksft_print_msg("failed to open for ns %s: %s\n",
+                              mnt_ns, strerror(errno));
+               sleep(60);
+               return NSID_ERROR;
+       }
+
+       if (ioctl(fd, NS_GET_MNTNS_ID, mnt_ns_id) < 0) {
+               ksft_print_msg("failed to get the nsid for ns %s: %s\n",
+                              mnt_ns, strerror(errno));
+               return NSID_ERROR;
+       }
+       close(fd);
+       return NSID_PASS;
+}
+
+static int get_mnt_id(const char *path, uint64_t *mnt_id)
+{
+       struct statx sx;
+       int ret;
+
+       ret = statx(AT_FDCWD, path, 0, STATX_MNT_ID_UNIQUE, &sx);
+       if (ret == -1) {
+               ksft_print_msg("retrieving unique mount ID for %s: %s\n", path,
+                              strerror(errno));
+               return NSID_ERROR;
+       }
+
+       if (!(sx.stx_mask & STATX_MNT_ID_UNIQUE)) {
+               ksft_print_msg("no unique mount ID available for %s\n", path);
+               return NSID_ERROR;
+       }
+
+       *mnt_id = sx.stx_mnt_id;
+       return NSID_PASS;
+}
+
+static int 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_print_msg("opening %s for write: %s\n", path, strerror(errno));
+               return NSID_ERROR;
+       }
+
+       ret = write(fd, val, len);
+       if (ret == -1) {
+               ksft_print_msg("writing to %s: %s\n", path, strerror(errno));
+               return NSID_ERROR;
+       }
+       if (ret != len) {
+               ksft_print_msg("short write to %s\n", path);
+               return NSID_ERROR;
+       }
+
+       ret = close(fd);
+       if (ret == -1) {
+               ksft_print_msg("closing %s\n", path);
+               return NSID_ERROR;
+       }
+
+       return NSID_PASS;
+}
+
+static int setup_namespace(void)
+{
+       int ret;
+       char buf[32];
+       uid_t uid = getuid();
+       gid_t gid = getgid();
+
+       ret = unshare(CLONE_NEWNS|CLONE_NEWUSER|CLONE_NEWPID);
+       if (ret == -1)
+               ksft_exit_fail_msg("unsharing mountns and userns: %s\n",
+                                  strerror(errno));
+
+       sprintf(buf, "0 %d 1", uid);
+       ret = write_file("/proc/self/uid_map", buf);
+       if (ret != NSID_PASS)
+               return ret;
+       ret = write_file("/proc/self/setgroups", "deny");
+       if (ret != NSID_PASS)
+               return ret;
+       sprintf(buf, "0 %d 1", gid);
+       ret = write_file("/proc/self/gid_map", buf);
+       if (ret != NSID_PASS)
+               return ret;
+
+       ret = mount("", "/", NULL, MS_REC|MS_PRIVATE, NULL);
+       if (ret == -1) {
+               ksft_print_msg("making mount tree private: %s\n",
+                              strerror(errno));
+               return NSID_ERROR;
+       }
+
+       return NSID_PASS;
+}
+
+static int _test_statmount_mnt_ns_id(void)
+{
+       struct statmount sm;
+       uint64_t mnt_ns_id;
+       uint64_t root_id;
+       int ret;
+
+       ret = get_mnt_ns_id("/proc/self/ns/mnt", &mnt_ns_id);
+       if (ret != NSID_PASS)
+               return ret;
+
+       ret = get_mnt_id("/", &root_id);
+       if (ret != NSID_PASS)
+               return ret;
+
+       ret = statmount(root_id, 0, STATMOUNT_MNT_NS_ID, &sm, sizeof(sm), 0);
+       if (ret == -1) {
+               ksft_print_msg("statmount mnt ns id: %s\n", strerror(errno));
+               return NSID_ERROR;
+       }
+
+       if (sm.size != sizeof(sm)) {
+               ksft_print_msg("unexpected size: %u != %u\n", sm.size,
+                              (uint32_t)sizeof(sm));
+               return NSID_FAIL;
+       }
+       if (sm.mask != STATMOUNT_MNT_NS_ID) {
+               ksft_print_msg("statmount mnt ns id unavailable\n");
+               return NSID_SKIP;
+       }
+
+       if (sm.mnt_ns_id != mnt_ns_id) {
+               ksft_print_msg("unexpected mnt ns ID: 0x%llx != 0x%llx\n",
+                              (unsigned long long)sm.mnt_ns_id,
+                              (unsigned long long)mnt_ns_id);
+               return NSID_FAIL;
+       }
+
+       return NSID_PASS;
+}
+
+static void test_statmount_mnt_ns_id(void)
+{
+       pid_t pid;
+       int ret;
+
+       pid = fork();
+       if (pid < 0)
+               ksft_exit_fail_msg("failed to fork: %s\n", strerror(errno));
+
+       /* We're the original pid, wait for the result. */
+       if (pid != 0) {
+               ret = wait_for_pid(pid);
+               handle_result(ret, "test statmount ns id");
+               return;
+       }
+
+       ret = setup_namespace();
+       if (ret != NSID_PASS)
+               exit(ret);
+       ret = _test_statmount_mnt_ns_id();
+       exit(ret);
+}
+
+static int validate_external_listmount(pid_t pid, uint64_t child_nr_mounts)
+{
+       uint64_t list[256];
+       uint64_t mnt_ns_id;
+       uint64_t nr_mounts;
+       char buf[256];
+       int ret;
+
+       /* Get the mount ns id for our child. */
+       snprintf(buf, sizeof(buf), "/proc/%lu/ns/mnt", (unsigned long)pid);
+       ret = get_mnt_ns_id(buf, &mnt_ns_id);
+
+       nr_mounts = listmount(LSMT_ROOT, mnt_ns_id, 0, list, 256, 0);
+       if (nr_mounts == (uint64_t)-1) {
+               ksft_print_msg("listmount: %s\n", strerror(errno));
+               return NSID_ERROR;
+       }
+
+       if (nr_mounts != child_nr_mounts) {
+               ksft_print_msg("listmount results is %zi != %zi\n", nr_mounts,
+                              child_nr_mounts);
+               return NSID_FAIL;
+       }
+
+       /* Validate that all of our entries match our mnt_ns_id. */
+       for (int i = 0; i < nr_mounts; i++) {
+               struct statmount sm;
+
+               ret = statmount(list[i], mnt_ns_id, STATMOUNT_MNT_NS_ID, &sm,
+                               sizeof(sm), 0);
+               if (ret < 0) {
+                       ksft_print_msg("statmount mnt ns id: %s\n", strerror(errno));
+                       return NSID_ERROR;
+               }
+
+               if (sm.mask != STATMOUNT_MNT_NS_ID) {
+                       ksft_print_msg("statmount mnt ns id unavailable\n");
+                       return NSID_SKIP;
+               }
+
+               if (sm.mnt_ns_id != mnt_ns_id) {
+                       ksft_print_msg("listmount gave us the wrong ns id: 0x%llx != 0x%llx\n",
+                                      (unsigned long long)sm.mnt_ns_id,
+                                      (unsigned long long)mnt_ns_id);
+                       return NSID_FAIL;
+               }
+       }
+
+       return NSID_PASS;
+}
+
+static void test_listmount_ns(void)
+{
+       uint64_t nr_mounts;
+       char pval;
+       int child_ready_pipe[2];
+       int parent_ready_pipe[2];
+       pid_t pid;
+       int ret, child_ret;
+
+       if (pipe(child_ready_pipe) < 0)
+               ksft_exit_fail_msg("failed to create the child pipe: %s\n",
+                                  strerror(errno));
+       if (pipe(parent_ready_pipe) < 0)
+               ksft_exit_fail_msg("failed to create the parent pipe: %s\n",
+                                  strerror(errno));
+
+       pid = fork();
+       if (pid < 0)
+               ksft_exit_fail_msg("failed to fork: %s\n", strerror(errno));
+
+       if (pid == 0) {
+               char cval;
+               uint64_t list[256];
+
+               close(child_ready_pipe[0]);
+               close(parent_ready_pipe[1]);
+
+               ret = setup_namespace();
+               if (ret != NSID_PASS)
+                       exit(ret);
+
+               nr_mounts = listmount(LSMT_ROOT, 0, 0, list, 256, 0);
+               if (nr_mounts == (uint64_t)-1) {
+                       ksft_print_msg("listmount: %s\n", strerror(errno));
+                       exit(NSID_FAIL);
+               }
+
+               /*
+                * Tell our parent how many mounts we have, and then wait for it
+                * to tell us we're done.
+                */
+               write(child_ready_pipe[1], &nr_mounts, sizeof(nr_mounts));
+               read(parent_ready_pipe[0], &cval, sizeof(cval));
+               exit(NSID_PASS);
+       }
+
+       close(child_ready_pipe[1]);
+       close(parent_ready_pipe[0]);
+
+       /* Wait until the child has created everything. */
+       if (read(child_ready_pipe[0], &nr_mounts, sizeof(nr_mounts)) !=
+           sizeof(nr_mounts))
+               ret = NSID_ERROR;
+
+       ret = validate_external_listmount(pid, nr_mounts);
+
+       if (write(parent_ready_pipe[1], &pval, sizeof(pval)) != sizeof(pval))
+               ret = NSID_ERROR;
+
+       child_ret = wait_for_pid(pid);
+       if (child_ret != NSID_PASS)
+               ret = child_ret;
+       handle_result(ret, "test listmount ns id");
+}
+
+int main(void)
+{
+       int ret;
+
+       ksft_print_header();
+       ret = statmount(0, 0, 0, NULL, 0, 0);
+       assert(ret == -1);
+       if (errno == ENOSYS)
+               ksft_exit_skip("statmount() syscall not supported\n");
+
+       ksft_set_plan(2);
+       test_statmount_mnt_ns_id();
+       test_listmount_ns();
+
+       if (ksft_get_fail_cnt() + ksft_get_error_cnt() > 0)
+               ksft_exit_fail();
+       else
+               ksft_exit_pass();
+}