Merge patch series "selftests: openat2: migrate to kselftest harness"

Aleksa Sarai <aleksa@amutable.com> says:

These tests were written in the early days of selftests' TAP support,
the more modern kselftest harness is much easier to follow and maintain.
The actual contents of the tests are unchanged by this change.

* patches from https://patch.msgid.link/20260401-openat2-selftests-kunit-v2-0-ad153a07da0c@amutable.com:
  selftests: openat2: migrate to kselftest harness
  selftests: openat2: switch from custom ARRAY_LEN to ARRAY_SIZE
  selftests: openat2: move helpers to header
  selftests: move openat2 tests to selftests/filesystems/

Link: https://patch.msgid.link/20260401-openat2-selftests-kunit-v2-0-ad153a07da0c@amutable.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

1 files changed, 313 insertions, 0 deletions

diff --git a/tools/testing/selftests/filesystems/openat2/openat2_test.c b/tools/testing/selftests/filesystems/openat2/openat2_test.c
new file mode 100644
index 000000000000..5ea3eebb7b59
--- /dev/null
+++ b/tools/testing/selftests/filesystems/openat2/openat2_test.c
@@ -0,0 +1,313 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Author: Aleksa Sarai <cyphar@cyphar.com>
+ * Copyright (C) 2018-2019 SUSE LLC.
+ */
+
+#define _GNU_SOURCE
+#define __SANE_USERSPACE_TYPES__ // Use ll64
+#include <fcntl.h>
+#include <sched.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/mount.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include "helpers.h"
+#include "kselftest_harness.h"
+
+/*
+ * O_LARGEFILE is set to 0 by glibc.
+ * XXX: This is wrong on {mips, parisc, powerpc, sparc}.
+ */
+#undef	O_LARGEFILE
+#ifdef __aarch64__
+#define	O_LARGEFILE 0x20000
+#else
+#define	O_LARGEFILE 0x8000
+#endif
+
+struct open_how_ext {
+	struct open_how inner;
+	uint32_t extra1;
+	char pad1[128];
+	uint32_t extra2;
+	char pad2[128];
+	uint32_t extra3;
+};
+
+struct struct_test {
+	const char *name;
+	struct open_how_ext arg;
+	size_t size;
+	int err;
+};
+
+struct flag_test {
+	const char *name;
+	struct open_how how;
+	int err;
+};
+
+FIXTURE(openat2) {};
+
+FIXTURE_SETUP(openat2)
+{
+	if (!openat2_supported)
+		SKIP(return, "openat2(2) not supported");
+}
+
+FIXTURE_TEARDOWN(openat2) {}
+
+/*
+ * Verify that the struct size and misalignment handling for openat2(2) is
+ * correct, including that is_zeroed_user() works.
+ */
+TEST_F(openat2, struct_argument_sizes)
+{
+	int misalignments[] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 17, 87 };
+	struct struct_test tests[] = {
+		/* Normal struct. */
+		{ .name = "normal struct",
+		  .arg.inner.flags = O_RDONLY,
+		  .size = sizeof(struct open_how) },
+		/* Bigger struct, with zeroed out end. */
+		{ .name = "bigger struct (zeroed out)",
+		  .arg.inner.flags = O_RDONLY,
+		  .size = sizeof(struct open_how_ext) },
+
+		/* TODO: Once expanded, check zero-padding. */
+
+		/* Smaller than version-0 struct. */
+		{ .name = "zero-sized 'struct'",
+		  .arg.inner.flags = O_RDONLY, .size = 0, .err = -EINVAL },
+		{ .name = "smaller-than-v0 struct",
+		  .arg.inner.flags = O_RDONLY,
+		  .size = OPEN_HOW_SIZE_VER0 - 1, .err = -EINVAL },
+
+		/* Bigger struct, with non-zero trailing bytes. */
+		{ .name = "bigger struct (non-zero data in first 'future field')",
+		  .arg.inner.flags = O_RDONLY, .arg.extra1 = 0xdeadbeef,
+		  .size = sizeof(struct open_how_ext), .err = -E2BIG },
+		{ .name = "bigger struct (non-zero data in middle of 'future fields')",
+		  .arg.inner.flags = O_RDONLY, .arg.extra2 = 0xfeedcafe,
+		  .size = sizeof(struct open_how_ext), .err = -E2BIG },
+		{ .name = "bigger struct (non-zero data at end of 'future fields')",
+		  .arg.inner.flags = O_RDONLY, .arg.extra3 = 0xabad1dea,
+		  .size = sizeof(struct open_how_ext), .err = -E2BIG },
+	};
+
+	for (int i = 0; i < ARRAY_SIZE(tests); i++) {
+		struct struct_test *test = &tests[i];
+		struct open_how_ext how_ext = test->arg;
+
+		for (int j = 0; j < ARRAY_SIZE(misalignments); j++) {
+			int fd, misalign = misalignments[j];
+			void *copy = NULL, *how_copy = &how_ext;
+			char *fdpath = NULL;
+
+			if (misalign) {
+				/*
+				 * Explicitly misalign the structure copying it with the given
+				 * (mis)alignment offset. The other data is set to be non-zero to
+				 * make sure that non-zero bytes outside the struct aren't checked
+				 *
+				 * This is effectively to check that is_zeroed_user() works.
+				 */
+				copy = malloc(misalign + sizeof(how_ext));
+				how_copy = copy + misalign;
+				memset(copy, 0xff, misalign);
+				memcpy(how_copy, &how_ext, sizeof(how_ext));
+			}
+
+			fd = raw_openat2(AT_FDCWD, ".", how_copy, test->size);
+			if (fd >= 0) {
+				fdpath = fdreadlink(_metadata, fd);
+				close(fd);
+			}
+
+			if (test->err >= 0) {
+				EXPECT_GE(fd, 0) {
+					TH_LOG("openat2 with %s [misalign=%d] should succeed, got %d (%s)",
+					       test->name, misalign,
+					       fd, strerror(-fd));
+				}
+			} else {
+				EXPECT_EQ(test->err, fd) {
+					if (fdpath)
+						TH_LOG("openat2 with %s [misalign=%d] should fail with %d (%s), got %d['%s']",
+						       test->name, misalign,
+						       test->err,
+						       strerror(-test->err),
+						       fd, fdpath);
+					else
+						TH_LOG("openat2 with %s [misalign=%d] should fail with %d (%s), got %d (%s)",
+						       test->name, misalign,
+						       test->err,
+						       strerror(-test->err),
+						       fd, strerror(-fd));
+				}
+			}
+
+			free(copy);
+			free(fdpath);
+		}
+	}
+}
+
+/* Verify openat2(2) flag and mode validation. */
+TEST_F(openat2, flag_validation)
+{
+	struct flag_test tests[] = {
+		/* O_TMPFILE is incompatible with O_PATH and O_CREAT. */
+		{ .name = "incompatible flags (O_TMPFILE | O_PATH)",
+		  .how.flags = O_TMPFILE | O_PATH | O_RDWR, .err = -EINVAL },
+		{ .name = "incompatible flags (O_TMPFILE | O_CREAT)",
+		  .how.flags = O_TMPFILE | O_CREAT | O_RDWR, .err = -EINVAL },
+
+		/* O_PATH only permits certain other flags to be set ... */
+		{ .name = "compatible flags (O_PATH | O_CLOEXEC)",
+		  .how.flags = O_PATH | O_CLOEXEC },
+		{ .name = "compatible flags (O_PATH | O_DIRECTORY)",
+		  .how.flags = O_PATH | O_DIRECTORY },
+		{ .name = "compatible flags (O_PATH | O_NOFOLLOW)",
+		  .how.flags = O_PATH | O_NOFOLLOW },
+		/* ... and others are absolutely not permitted. */
+		{ .name = "incompatible flags (O_PATH | O_RDWR)",
+		  .how.flags = O_PATH | O_RDWR, .err = -EINVAL },
+		{ .name = "incompatible flags (O_PATH | O_CREAT)",
+		  .how.flags = O_PATH | O_CREAT, .err = -EINVAL },
+		{ .name = "incompatible flags (O_PATH | O_EXCL)",
+		  .how.flags = O_PATH | O_EXCL, .err = -EINVAL },
+		{ .name = "incompatible flags (O_PATH | O_NOCTTY)",
+		  .how.flags = O_PATH | O_NOCTTY, .err = -EINVAL },
+		{ .name = "incompatible flags (O_PATH | O_DIRECT)",
+		  .how.flags = O_PATH | O_DIRECT, .err = -EINVAL },
+		{ .name = "incompatible flags (O_PATH | O_LARGEFILE)",
+		  .how.flags = O_PATH | O_LARGEFILE, .err = -EINVAL },
+
+		/* ->mode must only be set with O_{CREAT,TMPFILE}. */
+		{ .name = "non-zero how.mode and O_RDONLY",
+		  .how.flags = O_RDONLY, .how.mode = 0600, .err = -EINVAL },
+		{ .name = "non-zero how.mode and O_PATH",
+		  .how.flags = O_PATH,   .how.mode = 0600, .err = -EINVAL },
+		{ .name = "valid how.mode and O_CREAT",
+		  .how.flags = O_CREAT,  .how.mode = 0600 },
+		{ .name = "valid how.mode and O_TMPFILE",
+		  .how.flags = O_TMPFILE | O_RDWR, .how.mode = 0600 },
+		/* ->mode must only contain 0777 bits. */
+		{ .name = "invalid how.mode and O_CREAT",
+		  .how.flags = O_CREAT,
+		  .how.mode = 0xFFFF, .err = -EINVAL },
+		{ .name = "invalid (very large) how.mode and O_CREAT",
+		  .how.flags = O_CREAT,
+		  .how.mode = 0xC000000000000000ULL, .err = -EINVAL },
+		{ .name = "invalid how.mode and O_TMPFILE",
+		  .how.flags = O_TMPFILE | O_RDWR,
+		  .how.mode = 0x1337, .err = -EINVAL },
+		{ .name = "invalid (very large) how.mode and O_TMPFILE",
+		  .how.flags = O_TMPFILE | O_RDWR,
+		  .how.mode = 0x0000A00000000000ULL, .err = -EINVAL },
+
+		/* ->resolve flags must not conflict. */
+		{ .name = "incompatible resolve flags (BENEATH | IN_ROOT)",
+		  .how.flags = O_RDONLY,
+		  .how.resolve = RESOLVE_BENEATH | RESOLVE_IN_ROOT,
+		  .err = -EINVAL },
+
+		/* ->resolve must only contain RESOLVE_* flags. */
+		{ .name = "invalid how.resolve and O_RDONLY",
+		  .how.flags = O_RDONLY,
+		  .how.resolve = 0x1337, .err = -EINVAL },
+		{ .name = "invalid how.resolve and O_CREAT",
+		  .how.flags = O_CREAT,
+		  .how.resolve = 0x1337, .err = -EINVAL },
+		{ .name = "invalid how.resolve and O_TMPFILE",
+		  .how.flags = O_TMPFILE | O_RDWR,
+		  .how.resolve = 0x1337, .err = -EINVAL },
+		{ .name = "invalid how.resolve and O_PATH",
+		  .how.flags = O_PATH,
+		  .how.resolve = 0x1337, .err = -EINVAL },
+
+		/* currently unknown upper 32 bit rejected. */
+		{ .name = "currently unknown bit (1 << 63)",
+		  .how.flags = O_RDONLY | (1ULL << 63),
+		  .how.resolve = 0, .err = -EINVAL },
+	};
+
+	for (int i = 0; i < ARRAY_SIZE(tests); i++) {
+		int fd, fdflags = -1;
+		char *path, *fdpath = NULL;
+		struct flag_test *test = &tests[i];
+
+		path = (test->how.flags & O_CREAT) ? "/tmp/ksft.openat2_tmpfile" : ".";
+		unlink(path);
+
+		fd = sys_openat2(AT_FDCWD, path, &test->how);
+		if (fd < 0 && fd == -EOPNOTSUPP) {
+			/*
+			 * Skip the testcase if it failed because not supported
+			 * by FS. (e.g. a valid O_TMPFILE combination on NFS)
+			 */
+			TH_LOG("openat2 with %s not supported by FS -- skipping",
+			       test->name);
+			continue;
+		}
+
+		if (test->err >= 0) {
+			EXPECT_GE(fd, 0) {
+				TH_LOG("openat2 with %s should succeed, got %d (%s)",
+				       test->name, fd, strerror(-fd));
+			}
+			if (fd >= 0) {
+				int otherflags;
+
+				fdpath = fdreadlink(_metadata, fd);
+				fdflags = fcntl(fd, F_GETFL);
+				otherflags = fcntl(fd, F_GETFD);
+				close(fd);
+
+				ASSERT_GE(fdflags, 0);
+				ASSERT_GE(otherflags, 0);
+
+				/* O_CLOEXEC isn't shown in F_GETFL. */
+				if (otherflags & FD_CLOEXEC)
+					fdflags |= O_CLOEXEC;
+				/* O_CREAT is hidden from F_GETFL. */
+				if (test->how.flags & O_CREAT)
+					fdflags |= O_CREAT;
+				if (!(test->how.flags & O_LARGEFILE))
+					fdflags &= ~O_LARGEFILE;
+
+				EXPECT_EQ(fdflags, (int)test->how.flags) {
+					TH_LOG("openat2 with %s: flags mismatch %X != %llX",
+					       test->name, fdflags,
+					       (unsigned long long)test->how.flags);
+				}
+			}
+		} else {
+			EXPECT_EQ(test->err, fd) {
+				if (fd >= 0) {
+					fdpath = fdreadlink(_metadata, fd);
+					TH_LOG("openat2 with %s should fail with %d (%s), got %d['%s']",
+					       test->name, test->err,
+					       strerror(-test->err),
+					       fd, fdpath);
+				} else {
+					TH_LOG("openat2 with %s should fail with %d (%s), got %d (%s)",
+					       test->name, test->err,
+					       strerror(-test->err),
+					       fd, strerror(-fd));
+				}
+			}
+			if (fd >= 0)
+				close(fd);
+		}
+
+		free(fdpath);
+	}
+}
+
+TEST_HARNESS_MAIN