selftests/fchmodat2: clean up temporary files and directories

Patch series "selftests/fchmodat2: Error handling and general", v4.

I looked at the fchmodat2() tests since I've been experiencing some random
intermittent segfaults with them in my test systems, while doing so I
noticed these two issues.  Unfortunately I didn't figure out the original
yet, unless I managed to fix it unwittingly.


This patch (of 2):

The fchmodat2() test program creates a temporary directory with a file and
a symlink for every test it runs but never cleans these up, resulting in
${TMPDIR} getting left with stale files after every run.  Restructure the
program a bit to ensure that we clean these up, this is more invasive than
it might otherwise be due to the extensive use of ksft_exit_fail_msg() in
the program.

As a side effect this also ensures that we report a consistent test name
for the tests and always try both tests even if they are skipped.

Link: https://lkml.kernel.org/r/20260226-selftests-fchmodat2-v4-0-a6419435f2e8@kernel.org
Link: https://lkml.kernel.org/r/20260226-selftests-fchmodat2-v4-1-a6419435f2e8@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Alexey Gladkov <legion@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 111 insertions, 50 deletions

diff --git a/tools/testing/selftests/fchmodat2/fchmodat2_test.c b/tools/testing/selftests/fchmodat2/fchmodat2_test.c
index e397339495f6..e03430c4675c 100644
--- a/tools/testing/selftests/fchmodat2/fchmodat2_test.c
+++ b/tools/testing/selftests/fchmodat2/fchmodat2_test.c
@@ -9,6 +9,11 @@
 
 #include "kselftest.h"
 
+struct testdir {
+	char *dirname;
+	int dfd;
+};
+
 int sys_fchmodat2(int dfd, const char *filename, mode_t mode, int flags)
 {
 	int ret = syscall(__NR_fchmodat2, dfd, filename, mode, flags);
@@ -16,9 +21,9 @@ int sys_fchmodat2(int dfd, const char *filename, mode_t mode, int flags)
 	return ret >= 0 ? ret : -errno;
 }
 
-int setup_testdir(void)
+static void setup_testdir(struct testdir *testdir)
 {
-	int dfd, ret;
+	int ret, dfd;
 	char dirname[] = "/tmp/ksft-fchmodat2.XXXXXX";
 
 	/* Make the top-level directory. */
@@ -26,21 +31,48 @@ int setup_testdir(void)
 		ksft_exit_fail_msg("%s: failed to create tmpdir\n", __func__);
 
 	dfd = open(dirname, O_PATH | O_DIRECTORY);
-	if (dfd < 0)
-		ksft_exit_fail_msg("%s: failed to open tmpdir\n", __func__);
+	if (dfd < 0) {
+		ksft_perror("failed to open tmpdir");
+		goto err;
+	}
 
 	ret = openat(dfd, "regfile", O_CREAT | O_WRONLY | O_TRUNC, 0644);
-	if (ret < 0)
-		ksft_exit_fail_msg("%s: failed to create file in tmpdir\n",
-				__func__);
+	if (ret < 0) {
+		ksft_perror("failed to create file in tmpdir");
+		goto err;
+	}
 	close(ret);
 
 	ret = symlinkat("regfile", dfd, "symlink");
-	if (ret < 0)
-		ksft_exit_fail_msg("%s: failed to create symlink in tmpdir\n",
-				__func__);
+	if (ret < 0) {
+		ksft_perror("symlinkat() failed");
+		goto err_regfile;
+	}
+
+	testdir->dirname = strdup(dirname);
+	if (!testdir->dirname) {
+		ksft_perror("Out of memory");
+		goto err_symlink;
+	}
+	testdir->dfd = dfd;
+
+	return;
+
+err_symlink:
+	unlinkat(testdir->dfd, "symlink", 0);
+err_regfile:
+	unlinkat(testdir->dfd, "regfile", 0);
+err:
+	unlink(dirname);
+	ksft_exit_fail();
+}
 
-	return dfd;
+static void cleanup_testdir(struct testdir *testdir)
+{
+	unlinkat(testdir->dfd, "regfile", 0);
+	unlinkat(testdir->dfd, "symlink", 0);
+	rmdir(testdir->dirname);
+	free(testdir->dirname);
 }
 
 int expect_mode(int dfd, const char *filename, mode_t expect_mode)
@@ -48,61 +80,80 @@ int expect_mode(int dfd, const char *filename, mode_t expect_mode)
 	struct stat st;
 	int ret = fstatat(dfd, filename, &st, AT_SYMLINK_NOFOLLOW);
 
-	if (ret)
-		ksft_exit_fail_msg("%s: %s: fstatat failed\n",
-				__func__, filename);
+	if (ret) {
+		ksft_perror("fstatat() failed\n");
+		return 0;
+	}
 
 	return (st.st_mode == expect_mode);
 }
 
 void test_regfile(void)
 {
-	int dfd, ret;
-
-	dfd = setup_testdir();
+	struct testdir testdir;
+	int ret;
 
-	ret = sys_fchmodat2(dfd, "regfile", 0640, 0);
+	setup_testdir(&testdir);
 
-	if (ret < 0)
-		ksft_exit_fail_msg("%s: fchmodat2(noflag) failed\n", __func__);
-
-	if (!expect_mode(dfd, "regfile", 0100640))
-		ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2\n",
-				__func__);
+	ret = sys_fchmodat2(testdir.dfd, "regfile", 0640, 0);
 
-	ret = sys_fchmodat2(dfd, "regfile", 0600, AT_SYMLINK_NOFOLLOW);
+	if (ret < 0) {
+		ksft_perror("fchmodat2(noflag) failed");
+		goto out;
+	}
 
-	if (ret < 0)
-		ksft_exit_fail_msg("%s: fchmodat2(AT_SYMLINK_NOFOLLOW) failed\n",
+	if (!expect_mode(testdir.dfd, "regfile", 0100640)) {
+		ksft_print_msg("%s: wrong file mode bits after fchmodat2\n",
 				__func__);
-
-	if (!expect_mode(dfd, "regfile", 0100600))
-		ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2 with nofollow\n",
-				__func__);
-
-	ksft_test_result_pass("fchmodat2(regfile)\n");
+		ret = 1;
+		goto out;
+	}
+
+	ret = sys_fchmodat2(testdir.dfd, "regfile", 0600, AT_SYMLINK_NOFOLLOW);
+
+	if (ret < 0) {
+		ksft_perror("fchmodat2(AT_SYMLINK_NOFOLLOW) failed");
+		goto out;
+	}
+
+	if (!expect_mode(testdir.dfd, "regfile", 0100600)) {
+		ksft_print_msg("%s: wrong file mode bits after fchmodat2 with nofollow\n",
+			       __func__);
+		ret = 1;
+	}
+
+out:
+	ksft_test_result(ret == 0, "fchmodat2(regfile)\n");
+	cleanup_testdir(&testdir);
 }
 
 void test_symlink(void)
 {
-	int dfd, ret;
+	struct testdir testdir;
+	int ret;
 
-	dfd = setup_testdir();
+	setup_testdir(&testdir);
 
-	ret = sys_fchmodat2(dfd, "symlink", 0640, 0);
+	ret = sys_fchmodat2(testdir.dfd, "symlink", 0640, 0);
 
-	if (ret < 0)
-		ksft_exit_fail_msg("%s: fchmodat2(noflag) failed\n", __func__);
+	if (ret < 0) {
+		ksft_perror("fchmodat2(noflag) failed");
+		goto err;
+	}
 
-	if (!expect_mode(dfd, "regfile", 0100640))
-		ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2\n",
-				__func__);
+	if (!expect_mode(testdir.dfd, "regfile", 0100640)) {
+		ksft_print_msg("%s: wrong file mode bits after fchmodat2\n",
+			       __func__);
+		goto err;
+	}
 
-	if (!expect_mode(dfd, "symlink", 0120777))
-		ksft_exit_fail_msg("%s: wrong symlink mode bits after fchmodat2\n",
-				__func__);
+	if (!expect_mode(testdir.dfd, "symlink", 0120777)) {
+		ksft_print_msg("%s: wrong symlink mode bits after fchmodat2\n",
+			       __func__);
+		goto err;
+	}
 
-	ret = sys_fchmodat2(dfd, "symlink", 0600, AT_SYMLINK_NOFOLLOW);
+	ret = sys_fchmodat2(testdir.dfd, "symlink", 0600, AT_SYMLINK_NOFOLLOW);
 
 	/*
 	 * On certain filesystems (xfs or btrfs), chmod operation fails. So we
@@ -111,18 +162,28 @@ void test_symlink(void)
 	 *
 	 * https://sourceware.org/legacy-ml/libc-alpha/2020-02/msg00467.html
 	 */
-	if (ret == 0 && !expect_mode(dfd, "symlink", 0120600))
-		ksft_exit_fail_msg("%s: wrong symlink mode bits after fchmodat2 with nofollow\n",
+	if (ret == 0 && !expect_mode(testdir.dfd, "symlink", 0120600)) {
+		ksft_print_msg("%s: wrong symlink mode bits after fchmodat2 with nofollow\n",
 				__func__);
+		ret = 1;
+		goto err;
+	}
 
-	if (!expect_mode(dfd, "regfile", 0100640))
-		ksft_exit_fail_msg("%s: wrong file mode bits after fchmodat2 with nofollow\n",
-				__func__);
+	if (!expect_mode(testdir.dfd, "regfile", 0100640)) {
+		ksft_print_msg("%s: wrong file mode bits after fchmodat2 with nofollow\n",
+			       __func__);
+	}
 
 	if (ret != 0)
 		ksft_test_result_skip("fchmodat2(symlink)\n");
 	else
 		ksft_test_result_pass("fchmodat2(symlink)\n");
+	cleanup_testdir(&testdir);
+	return;
+
+err:
+	ksft_test_result_fail("fchmodat2(symlink)\n");
+	cleanup_testdir(&testdir);
 }
 
 #define NUM_TESTS 2