linux-security-module.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH v5] selftests/landlock: Skip overlayfs tests not supported
@ 2022-08-24  1:58 jeffxu
  2022-08-25  8:23 ` Mickaël Salaün
  0 siblings, 1 reply; 4+ messages in thread
From: jeffxu @ 2022-08-24  1:58 UTC (permalink / raw)
  To: mic; +Cc: jorgelo, keescook, linux-security-module, groeck, Jeff Xu

From: Jeff Xu <jeffxu@chromium.org>

overlayfs can be disabled in the kernel configuration (which is the case
for chromeOS), causing related tests to fail.  Skip such tests when an
overlayfs mount operation failed because the running kernel doesn't
support this file system.

Signed-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
---
 tools/testing/selftests/landlock/fs_test.c | 54 ++++++++++++++++++++--
 1 file changed, 51 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/landlock/fs_test.c b/tools/testing/selftests/landlock/fs_test.c
index 21a2ce8fa739..645304d9fe98 100644
--- a/tools/testing/selftests/landlock/fs_test.c
+++ b/tools/testing/selftests/landlock/fs_test.c
@@ -11,6 +11,7 @@
 #include <fcntl.h>
 #include <linux/landlock.h>
 #include <sched.h>
+#include <stdio.h>
 #include <string.h>
 #include <sys/capability.h>
 #include <sys/mount.h>
@@ -169,6 +170,42 @@ static int remove_path(const char *const path)
 	return err;
 }
 
+static bool fgrep(FILE *file, const char *str)
+{
+	char line[32];
+	int str_len = strlen(str);
+
+	while (!feof(file)) {
+		if (!fgets(line, sizeof(line), file))
+			break;
+		if (strncmp(line, str, str_len))
+			continue;
+
+		return true;
+	}
+
+	return false;
+}
+
+static bool supports_overlayfs(void)
+{
+	bool ret;
+	FILE *file = fopen("/proc/filesystems", "r");
+
+	/*
+	 * A failed attempt to open /proc/filesystems
+	 * implies that the file system is supported (default
+	 * behavior). This can help detect such unattended issue
+	 * (which should not happen)."
+	 */
+	if (!file)
+		return true;
+
+	ret = fgrep(file, "nodev\toverlay\n");
+	fclose(file);
+	return ret;
+}
+
 static void prepare_layout(struct __test_metadata *const _metadata)
 {
 	disable_caps(_metadata);
@@ -3404,6 +3441,8 @@ FIXTURE(layout2_overlay) {};
 
 FIXTURE_SETUP(layout2_overlay)
 {
+	int ret, err;
+
 	prepare_layout(_metadata);
 
 	create_directory(_metadata, LOWER_BASE);
@@ -3431,11 +3470,20 @@ FIXTURE_SETUP(layout2_overlay)
 	create_directory(_metadata, MERGE_DATA);
 	set_cap(_metadata, CAP_SYS_ADMIN);
 	set_cap(_metadata, CAP_DAC_OVERRIDE);
-	ASSERT_EQ(0, mount("overlay", MERGE_DATA, "overlay", 0,
-			   "lowerdir=" LOWER_DATA ",upperdir=" UPPER_DATA
-			   ",workdir=" UPPER_WORK));
+
+	ret = mount("overlay", MERGE_DATA, "overlay", 0,
+		   "lowerdir=" LOWER_DATA ",upperdir=" UPPER_DATA
+		   ",workdir=" UPPER_WORK);
+	err = errno;
 	clear_cap(_metadata, CAP_DAC_OVERRIDE);
 	clear_cap(_metadata, CAP_SYS_ADMIN);
+
+	if (ret == -1) {
+		ASSERT_EQ(ENODEV, err);
+		ASSERT_FALSE(supports_overlayfs());
+		SKIP(return, "overlayfs is not supported");
+	}
+	ASSERT_EQ(0, ret);
 }
 
 FIXTURE_TEARDOWN(layout2_overlay)

base-commit: 50cd95ac46548429e5bba7ca75cc97d11a697947
-- 
2.37.1.595.g718a3a8f04-goog


^ permalink raw reply related	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2022-09-27 16:49 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2022-08-24  1:58 [PATCH v5] selftests/landlock: Skip overlayfs tests not supported jeffxu
2022-08-25  8:23 ` Mickaël Salaün
2022-09-26 14:23   ` Jeff Xu
2022-09-27 16:47     ` Mickaël Salaün

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).