[libc-commits] [libc] [libc] add ioctl (PR #141393)
via libc-commits
libc-commits at lists.llvm.org
Sat May 24 20:15:25 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-libc
Author: ~cowtools (cowtoolz)
<details>
<summary>Changes</summary>
Closes #<!-- -->85275
Closes #<!-- -->90317
---
Full diff: https://github.com/llvm/llvm-project/pull/141393.diff
13 Files Affected:
- (modified) libc/config/linux/aarch64/entrypoints.txt (+3)
- (modified) libc/config/linux/arm/entrypoints.txt (+3)
- (modified) libc/config/linux/riscv/entrypoints.txt (+3)
- (modified) libc/config/linux/x86_64/entrypoints.txt (+3)
- (modified) libc/src/sys/CMakeLists.txt (+1)
- (added) libc/src/sys/ioctl/CMakeLists.txt (+10)
- (added) libc/src/sys/ioctl/ioctl.h (+21)
- (added) libc/src/sys/ioctl/linux/CMakeLists.txt (+12)
- (added) libc/src/sys/ioctl/linux/ioctl.cpp (+40)
- (modified) libc/test/src/sys/CMakeLists.txt (+1)
- (added) libc/test/src/sys/ioctl/CMakeLists.txt (+3)
- (added) libc/test/src/sys/ioctl/linux/CMakeLists.txt (+14)
- (added) libc/test/src/sys/ioctl/linux/ioctl_test.cpp (+34)
``````````diff
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index 520046f768b5d..fcf1278eae723 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -245,6 +245,9 @@ set(TARGET_LIBC_ENTRYPOINTS
# https://github.com/llvm/llvm-project/issues/80060
# libc.src.sys.epoll.epoll_pwait2
+ # sys/ioctl.h entrypoints
+ libc.src.sys.ioctl.ioctl
+
# sys/mman.h entrypoints
libc.src.sys.mman.madvise
libc.src.sys.mman.mincore
diff --git a/libc/config/linux/arm/entrypoints.txt b/libc/config/linux/arm/entrypoints.txt
index 7432a7e912e81..1161ae260be2e 100644
--- a/libc/config/linux/arm/entrypoints.txt
+++ b/libc/config/linux/arm/entrypoints.txt
@@ -172,6 +172,9 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.stdlib.free
libc.src.stdlib.malloc
+ # sys/ioctl.h entrypoints
+ libc.src.sys.ioctl.ioctl
+
# sys/mman.h entrypoints
libc.src.sys.mman.mmap
libc.src.sys.mman.munmap
diff --git a/libc/config/linux/riscv/entrypoints.txt b/libc/config/linux/riscv/entrypoints.txt
index 0b645a2d2fb8b..050fc2672a57e 100644
--- a/libc/config/linux/riscv/entrypoints.txt
+++ b/libc/config/linux/riscv/entrypoints.txt
@@ -246,6 +246,9 @@ set(TARGET_LIBC_ENTRYPOINTS
# https://github.com/llvm/llvm-project/issues/80060
# libc.src.sys.epoll.epoll_pwait2
+ # sys/ioctl.h entrypoints
+ libc.src.sys.ioctl.ioctl
+
# sys/mman.h entrypoints
libc.src.sys.mman.madvise
libc.src.sys.mman.mincore
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index 9f447dd0d35d2..07ebf51f70774 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -246,6 +246,9 @@ set(TARGET_LIBC_ENTRYPOINTS
# https://github.com/llvm/llvm-project/issues/80060
# libc.src.sys.epoll.epoll_pwait2
+ # sys/ioctl.h entrypoints
+ libc.src.sys.ioctl.ioctl
+
# sys/mman.h entrypoints
libc.src.sys.mman.madvise
libc.src.sys.mman.mincore
diff --git a/libc/src/sys/CMakeLists.txt b/libc/src/sys/CMakeLists.txt
index 9a73b80d35d2f..0fa11e9eee696 100644
--- a/libc/src/sys/CMakeLists.txt
+++ b/libc/src/sys/CMakeLists.txt
@@ -13,3 +13,4 @@ add_subdirectory(utsname)
add_subdirectory(wait)
add_subdirectory(prctl)
add_subdirectory(uio)
+add_subdirectory(ioctl)
diff --git a/libc/src/sys/ioctl/CMakeLists.txt b/libc/src/sys/ioctl/CMakeLists.txt
new file mode 100644
index 0000000000000..099a1b96389fc
--- /dev/null
+++ b/libc/src/sys/ioctl/CMakeLists.txt
@@ -0,0 +1,10 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+ add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+endif()
+
+add_entrypoint_object(
+ ioctl
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.ioctl
+)
diff --git a/libc/src/sys/ioctl/ioctl.h b/libc/src/sys/ioctl/ioctl.h
new file mode 100644
index 0000000000000..91d6bb7f7abe7
--- /dev/null
+++ b/libc/src/sys/ioctl/ioctl.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for ioctl ---------------------------*-C++-*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_IOCTL_IOCTL_H
+#define LLVM_LIBC_SRC_SYS_IOCTL_IOCTL_H
+
+#include "src/__support/macros/config.h"
+#include <sys/ioctl.h>
+
+namespace LIBC_NAMESPACE_DECL {
+
+int ioctl(int fd, unsigned long request, ...);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_IOCTL_IOCTL_H
diff --git a/libc/src/sys/ioctl/linux/CMakeLists.txt b/libc/src/sys/ioctl/linux/CMakeLists.txt
new file mode 100644
index 0000000000000..876f35aaee66c
--- /dev/null
+++ b/libc/src/sys/ioctl/linux/CMakeLists.txt
@@ -0,0 +1,12 @@
+add_entrypoint_object(
+ ioctl
+ SRCS
+ ioctl.cpp
+ HDRS
+ ../ioctl.h
+ DEPENDS
+ libc.include.sys_ioctl
+ libc.include.sys_syscall
+ libc.src.__support.OSUtil.osutil
+ libc.src.errno.errno
+)
diff --git a/libc/src/sys/ioctl/linux/ioctl.cpp b/libc/src/sys/ioctl/linux/ioctl.cpp
new file mode 100644
index 0000000000000..898385027105c
--- /dev/null
+++ b/libc/src/sys/ioctl/linux/ioctl.cpp
@@ -0,0 +1,40 @@
+//===---------- Linux implementation of the ioctl function ----------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/sys/ioctl/ioctl.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+#include "src/errno/libc_errno.h"
+#include <stdarg.h>
+#include <sys/syscall.h> // For syscall numbers.
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(int, ioctl, (int fd, unsigned long request, ...)) {
+ va_list vargs;
+ va_start(vargs, request);
+ void *data_pointer = va_arg(vargs, void *);
+ int ret =
+ LIBC_NAMESPACE::syscall_impl<int>(SYS_ioctl, fd, request, data_pointer);
+ va_end(vargs);
+
+ // From `man ioctl`:
+ // "Usually, on success zero is returned. A few ioctl() operations
+ // use the return value as an output parameter and return a
+ // nonnegative value on success. On error, -1 is returned, and errno
+ // is set to indicate the error."
+ if (ret < 0) {
+ libc_errno = -ret;
+ return -1;
+ }
+
+ return ret;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/test/src/sys/CMakeLists.txt b/libc/test/src/sys/CMakeLists.txt
index 224cc7905ad31..13bf91eef04be 100644
--- a/libc/test/src/sys/CMakeLists.txt
+++ b/libc/test/src/sys/CMakeLists.txt
@@ -13,3 +13,4 @@ add_subdirectory(auxv)
add_subdirectory(epoll)
add_subdirectory(uio)
add_subdirectory(time)
+add_subdirectory(ioctl)
diff --git a/libc/test/src/sys/ioctl/CMakeLists.txt b/libc/test/src/sys/ioctl/CMakeLists.txt
new file mode 100644
index 0000000000000..b4bbe81c92ff2
--- /dev/null
+++ b/libc/test/src/sys/ioctl/CMakeLists.txt
@@ -0,0 +1,3 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+ add_subdirectory(${LIBC_TARGET_OS})
+endif()
diff --git a/libc/test/src/sys/ioctl/linux/CMakeLists.txt b/libc/test/src/sys/ioctl/linux/CMakeLists.txt
new file mode 100644
index 0000000000000..1466453fe08aa
--- /dev/null
+++ b/libc/test/src/sys/ioctl/linux/CMakeLists.txt
@@ -0,0 +1,14 @@
+add_custom_target(libc_sys_ioctl_unittests)
+
+add_libc_unittest(
+ ioctl_test
+ SUITE
+ libc_sys_ioctl_unittests
+ SRCS
+ ioctl_test.cpp
+ DEPENDS
+ libc.include.sys_ioctl
+ libc.include.sys_filio
+ libc.src.sys.ioctl.ioctl
+ libc.src.errno.errno
+)
diff --git a/libc/test/src/sys/ioctl/linux/ioctl_test.cpp b/libc/test/src/sys/ioctl/linux/ioctl_test.cpp
new file mode 100644
index 0000000000000..1752db8a57ce7
--- /dev/null
+++ b/libc/test/src/sys/ioctl/linux/ioctl_test.cpp
@@ -0,0 +1,34 @@
+//===-- Unittests for ioctl -----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/errno/libc_errno.h"
+#include "src/sys/ioctl/ioctl.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include <sys/filio.h>
+#include <sys/ioctl.h>
+
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+
+TEST(LlvmLibcSysIoctlTest, StdinFIONREAD) {
+ LIBC_NAMESPACE::libc_errno = 0;
+
+ // FIONREAD reports the number of readable bytes for fd
+ int bytes;
+ int ret = LIBC_NAMESPACE::ioctl(0, FIONREAD, &bytes);
+ ASSERT_ERRNO_SUCCESS();
+}
+
+TEST(LlvmLibcSysIoctlTest, InvalidCommandENOTTY) {
+ LIBC_NAMESPACE::libc_errno = 0;
+
+ // 0xDEADBEEF is just a random nonexistent command;
+ // calling this should always fail with ENOTTY
+ int ret = LIBC_NAMESPACE::ioctl(3, 0xDEADBEEF, NULL);
+ ASSERT_TRUE(ret == -1 && errno == ENOTTY);
+}
``````````
</details>
https://github.com/llvm/llvm-project/pull/141393
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