[libc-commits] [libc] [libc] Return errno from OFD failure paths in fcntl. (PR #166252)
Jackson Stogel via libc-commits
libc-commits at lists.llvm.org
Wed Nov 5 13:20:01 PST 2025
https://github.com/jtstogel updated https://github.com/llvm/llvm-project/pull/166252
>From c405238598ca0a84efec136ed27c4d552e8de068 Mon Sep 17 00:00:00 2001
From: Jackson Stogel <jtstogel at gmail.com>
Date: Mon, 3 Nov 2025 22:48:55 +0000
Subject: [PATCH 1/3] Return errno from F_OFD_SETLKW failure path in fcntl.
---
libc/src/__support/OSUtil/linux/fcntl.cpp | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libc/src/__support/OSUtil/linux/fcntl.cpp b/libc/src/__support/OSUtil/linux/fcntl.cpp
index bb76eee90efd2..08db4859c6417 100644
--- a/libc/src/__support/OSUtil/linux/fcntl.cpp
+++ b/libc/src/__support/OSUtil/linux/fcntl.cpp
@@ -66,7 +66,7 @@ ErrorOr<int> fcntl(int fd, int cmd, void *arg) {
LIBC_NAMESPACE::syscall_impl<int>(FCNTL_SYSCALL_ID, fd, cmd, &flk64);
// On failure, return
if (ret < 0)
- return Error(-1);
+ return Error(-ret);
// Check for overflow, i.e. the offsets are not the same when cast
// to off_t from off64_t.
if (static_cast<off_t>(flk64.l_len) != flk64.l_len ||
>From 0a403ccf22c8fb423024bc65d8d1797f7131fb74 Mon Sep 17 00:00:00 2001
From: Jackson Stogel <jtstogel at gmail.com>
Date: Wed, 5 Nov 2025 19:43:33 +0000
Subject: [PATCH 2/3] Include OFD variants in existing fcntl lock tests.
---
libc/test/src/fcntl/fcntl_test.cpp | 164 ++++++++++++++++-------------
1 file changed, 92 insertions(+), 72 deletions(-)
diff --git a/libc/test/src/fcntl/fcntl_test.cpp b/libc/test/src/fcntl/fcntl_test.cpp
index 84feb34e537a0..d66b969c7e70b 100644
--- a/libc/test/src/fcntl/fcntl_test.cpp
+++ b/libc/test/src/fcntl/fcntl_test.cpp
@@ -94,78 +94,98 @@ TEST_F(LlvmLibcFcntlTest, FcntlSetFl) {
ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
}
-TEST_F(LlvmLibcFcntlTest, FcntlGetLkRead) {
- using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
- constexpr const char *TEST_FILE_NAME = "testdata/fcntl_getlkread.test";
- auto TEST_FILE = libc_make_test_file_path(TEST_FILE_NAME);
-
- struct flock flk, svflk;
- int retVal;
- int fd =
- LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_TRUNC | O_RDONLY, S_IRWXU);
- ASSERT_ERRNO_SUCCESS();
- ASSERT_GT(fd, 0);
-
- flk.l_type = F_RDLCK;
- flk.l_start = 0;
- flk.l_whence = SEEK_SET;
- flk.l_len = 50;
-
- // copy flk into svflk
- svflk = flk;
-
- retVal = LIBC_NAMESPACE::fcntl(fd, F_GETLK, &svflk);
- ASSERT_ERRNO_SUCCESS();
- ASSERT_GT(retVal, -1);
- ASSERT_NE((int)flk.l_type, F_WRLCK); // File should not be write locked.
-
- retVal = LIBC_NAMESPACE::fcntl(fd, F_SETLK, &svflk);
- ASSERT_ERRNO_SUCCESS();
- ASSERT_GT(retVal, -1);
-
- ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
-}
-
-TEST_F(LlvmLibcFcntlTest, FcntlGetLkWrite) {
- using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
- constexpr const char *TEST_FILE_NAME = "testdata/fcntl_getlkwrite.test";
- auto TEST_FILE = libc_make_test_file_path(TEST_FILE_NAME);
-
- struct flock flk, svflk;
- int retVal;
- int fd = LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_TRUNC | O_RDWR, S_IRWXU);
- ASSERT_ERRNO_SUCCESS();
- ASSERT_GT(fd, 0);
-
- flk.l_type = F_WRLCK;
- flk.l_start = 0;
- flk.l_whence = SEEK_SET;
- flk.l_len = 0;
-
- // copy flk into svflk
- svflk = flk;
-
- retVal = LIBC_NAMESPACE::fcntl(fd, F_GETLK, &svflk);
- ASSERT_ERRNO_SUCCESS();
- ASSERT_GT(retVal, -1);
- ASSERT_NE((int)flk.l_type, F_RDLCK); // File should not be read locked.
-
- retVal = LIBC_NAMESPACE::fcntl(fd, F_SETLK, &svflk);
- ASSERT_ERRNO_SUCCESS();
- ASSERT_GT(retVal, -1);
-
- ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
-}
-
-TEST_F(LlvmLibcFcntlTest, UseAfterClose) {
- using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
- constexpr const char *TEST_FILE_NAME = "testdata/fcntl_use_after_close.test";
- auto TEST_FILE = libc_make_test_file_path(TEST_FILE_NAME);
- int fd = LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_TRUNC | O_RDWR, S_IRWXU);
- ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
- ASSERT_EQ(-1, LIBC_NAMESPACE::fcntl(fd, F_GETFL));
- ASSERT_ERRNO_EQ(EBADF);
-}
+/* Tests that are common between OFD and traditional variants of fcntl locks. */
+template <int GETLK_CMD, int SETLK_CMD>
+class LibcFcntlCommonLockTests : public LlvmLibcFcntlTest {
+public:
+ void GetLkRead() {
+ using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+ constexpr const char *TEST_FILE_NAME = "testdata/fcntl_getlkread.test";
+ const auto TEST_FILE = libc_make_test_file_path(TEST_FILE_NAME);
+
+ struct flock flk = {};
+ struct flock svflk = {};
+ int retVal;
+ int fd =
+ LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_TRUNC | O_RDONLY, S_IRWXU);
+ ASSERT_ERRNO_SUCCESS();
+ ASSERT_GT(fd, 0);
+
+ flk.l_type = F_RDLCK;
+ flk.l_start = 0;
+ flk.l_whence = SEEK_SET;
+ flk.l_len = 50;
+
+ // copy flk into svflk
+ svflk = flk;
+
+ retVal = LIBC_NAMESPACE::fcntl(fd, GETLK_CMD, &svflk);
+ ASSERT_ERRNO_SUCCESS();
+ ASSERT_GT(retVal, -1);
+ ASSERT_NE((int)svflk.l_type, F_WRLCK); // File should not be write locked.
+
+ retVal = LIBC_NAMESPACE::fcntl(fd, SETLK_CMD, &svflk);
+ ASSERT_ERRNO_SUCCESS();
+ ASSERT_GT(retVal, -1);
+
+ ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
+ }
+
+ void GetLkWrite() {
+ using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+ constexpr const char *TEST_FILE_NAME = "testdata/fcntl_getlkwrite.test";
+ const auto TEST_FILE = libc_make_test_file_path(TEST_FILE_NAME);
+
+ struct flock flk = {};
+ struct flock svflk = {};
+ int retVal;
+ int fd =
+ LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_TRUNC | O_RDWR, S_IRWXU);
+ ASSERT_ERRNO_SUCCESS();
+ ASSERT_GT(fd, 0);
+
+ flk.l_type = F_WRLCK;
+ flk.l_start = 0;
+ flk.l_whence = SEEK_SET;
+ flk.l_len = 0;
+
+ // copy flk into svflk
+ svflk = flk;
+
+ retVal = LIBC_NAMESPACE::fcntl(fd, GETLK_CMD, &svflk);
+ ASSERT_ERRNO_SUCCESS();
+ ASSERT_GT(retVal, -1);
+ ASSERT_NE((int)svflk.l_type, F_RDLCK); // File should not be read locked.
+
+ retVal = LIBC_NAMESPACE::fcntl(fd, SETLK_CMD, &svflk);
+ ASSERT_ERRNO_SUCCESS();
+ ASSERT_GT(retVal, -1);
+
+ ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
+ }
+
+ void UseAfterClose() {
+ using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+ constexpr const char *TEST_FILE_NAME =
+ "testdata/fcntl_use_after_close.test";
+ const auto TEST_FILE = libc_make_test_file_path(TEST_FILE_NAME);
+ int fd =
+ LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_TRUNC | O_RDWR, S_IRWXU);
+ ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
+ ASSERT_EQ(-1, LIBC_NAMESPACE::fcntl(fd, GETLK_CMD));
+ ASSERT_ERRNO_EQ(EBADF);
+ }
+};
+
+#define COMMON_LOCK_TESTS(NAME, GETLK, SETLK) \
+ using NAME = LibcFcntlCommonLockTests<GETLK, SETLK>; \
+ TEST_F(NAME, GetLkRead) { GetLkRead(); } \
+ TEST_F(NAME, GetLkWrite) { GetLkWrite(); } \
+ TEST_F(NAME, UseAfterClose) { UseAfterClose(); }
+
+COMMON_LOCK_TESTS(LlvmLibcFcntlProcessAssociatedLockTest, F_GETLK, F_SETLK)
+COMMON_LOCK_TESTS(LlvmLibcFcntlOpenFileDescriptionLockTest, F_OFD_GETLK,
+ F_OFD_SETLK)
TEST_F(LlvmLibcFcntlTest, SetGetOwnerTest) {
using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
>From 75918bb9957d456c7a1bdc79effb1b2d7d39a328 Mon Sep 17 00:00:00 2001
From: Jackson Stogel <jtstogel at gmail.com>
Date: Wed, 5 Nov 2025 21:19:43 +0000
Subject: [PATCH 3/3] Allow COMMON_LOCK_TESTS macro to be suffixed with a
semicolon.
---
libc/test/src/fcntl/fcntl_test.cpp | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/libc/test/src/fcntl/fcntl_test.cpp b/libc/test/src/fcntl/fcntl_test.cpp
index d66b969c7e70b..d6aaccddd76ee 100644
--- a/libc/test/src/fcntl/fcntl_test.cpp
+++ b/libc/test/src/fcntl/fcntl_test.cpp
@@ -181,11 +181,12 @@ class LibcFcntlCommonLockTests : public LlvmLibcFcntlTest {
using NAME = LibcFcntlCommonLockTests<GETLK, SETLK>; \
TEST_F(NAME, GetLkRead) { GetLkRead(); } \
TEST_F(NAME, GetLkWrite) { GetLkWrite(); } \
- TEST_F(NAME, UseAfterClose) { UseAfterClose(); }
+ TEST_F(NAME, UseAfterClose) { UseAfterClose(); } \
+ static_assert(true, "Require semicolon.")
-COMMON_LOCK_TESTS(LlvmLibcFcntlProcessAssociatedLockTest, F_GETLK, F_SETLK)
+COMMON_LOCK_TESTS(LlvmLibcFcntlProcessAssociatedLockTest, F_GETLK, F_SETLK);
COMMON_LOCK_TESTS(LlvmLibcFcntlOpenFileDescriptionLockTest, F_OFD_GETLK,
- F_OFD_SETLK)
+ F_OFD_SETLK);
TEST_F(LlvmLibcFcntlTest, SetGetOwnerTest) {
using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
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