[libc-commits] [libc] 5a6cc50 - [libc] add mremap (#112804)
via libc-commits
libc-commits at lists.llvm.org
Wed Nov 6 10:25:53 PST 2024
Author: Jingyu Qiu
Date: 2024-11-06T10:25:50-08:00
New Revision: 5a6cc509215b62e94de3b798ea26944a375ce6cb
URL: https://github.com/llvm/llvm-project/commit/5a6cc509215b62e94de3b798ea26944a375ce6cb
DIFF: https://github.com/llvm/llvm-project/commit/5a6cc509215b62e94de3b798ea26944a375ce6cb.diff
LOG: [libc] add mremap (#112804)
Added:
libc/src/sys/mman/linux/mremap.cpp
libc/src/sys/mman/mremap.h
libc/test/src/sys/mman/linux/mremap_test.cpp
Modified:
libc/config/linux/aarch64/entrypoints.txt
libc/config/linux/x86_64/entrypoints.txt
libc/newhdrgen/yaml/sys/mman.yaml
libc/spec/linux.td
libc/src/sys/mman/CMakeLists.txt
libc/src/sys/mman/linux/CMakeLists.txt
libc/test/src/sys/mman/linux/CMakeLists.txt
Removed:
################################################################################
diff --git a/libc/config/linux/aarch64/entrypoints.txt b/libc/config/linux/aarch64/entrypoints.txt
index bf60d6f000529f..571527426de31b 100644
--- a/libc/config/linux/aarch64/entrypoints.txt
+++ b/libc/config/linux/aarch64/entrypoints.txt
@@ -245,6 +245,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.sys.mman.mlock2
libc.src.sys.mman.mlockall
libc.src.sys.mman.mmap
+ libc.src.sys.mman.mremap
libc.src.sys.mman.mprotect
libc.src.sys.mman.msync
libc.src.sys.mman.munlock
diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index b8c2a82a4d5b2f..9a4a0ff9e75a40 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -244,6 +244,7 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.sys.mman.mlock2
libc.src.sys.mman.mlockall
libc.src.sys.mman.mmap
+ libc.src.sys.mman.mremap
libc.src.sys.mman.mprotect
libc.src.sys.mman.msync
libc.src.sys.mman.munlock
diff --git a/libc/newhdrgen/yaml/sys/mman.yaml b/libc/newhdrgen/yaml/sys/mman.yaml
index 7c4fb1ef09e791..962ca3591917f7 100644
--- a/libc/newhdrgen/yaml/sys/mman.yaml
+++ b/libc/newhdrgen/yaml/sys/mman.yaml
@@ -55,6 +55,16 @@ functions:
- type: int
- type: int
- type: off_t
+ - name: mremap
+ standards:
+ - POSIX
+ return_type: void *
+ arguments:
+ - type: void *
+ - type: size_t
+ - type: size_t
+ - type: int
+ - type: '...'
- name: mprotect
standards:
- POSIX
diff --git a/libc/spec/linux.td b/libc/spec/linux.td
index c8604e8184f681..9b5dc8e30c95e4 100644
--- a/libc/spec/linux.td
+++ b/libc/spec/linux.td
@@ -103,7 +103,7 @@ def Linux : StandardSpec<"Linux"> {
ArgSpec<UnsignedIntType>,
]
>,
- FunctionSpec<
+ FunctionSpec<
"remap_file_pages",
RetValSpec<IntType>,
[
@@ -114,6 +114,17 @@ def Linux : StandardSpec<"Linux"> {
ArgSpec<IntType>,
]
>,
+ FunctionSpec<
+ "mremap",
+ RetValSpec<VoidPtr>,
+ [
+ ArgSpec<VoidPtr>,
+ ArgSpec<SizeTType>,
+ ArgSpec<SizeTType>,
+ ArgSpec<IntType>,
+ ArgSpec<VarArgType>,
+ ]
+ >,
] // Functions
>;
diff --git a/libc/src/sys/mman/CMakeLists.txt b/libc/src/sys/mman/CMakeLists.txt
index 4ea43e14be0297..4d4c2ad376050e 100644
--- a/libc/src/sys/mman/CMakeLists.txt
+++ b/libc/src/sys/mman/CMakeLists.txt
@@ -106,3 +106,10 @@ add_entrypoint_object(
DEPENDS
.${LIBC_TARGET_OS}.shm_unlink
)
+
+add_entrypoint_object(
+ mremap
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.mremap
+)
diff --git a/libc/src/sys/mman/linux/CMakeLists.txt b/libc/src/sys/mman/linux/CMakeLists.txt
index 47c16f79bc8d58..89a0ad1527a065 100644
--- a/libc/src/sys/mman/linux/CMakeLists.txt
+++ b/libc/src/sys/mman/linux/CMakeLists.txt
@@ -24,6 +24,19 @@ add_entrypoint_object(
libc.src.errno.errno
)
+add_entrypoint_object(
+ mremap
+ SRCS
+ mremap.cpp
+ HDRS
+ ../mremap.h
+ DEPENDS
+ libc.include.sys_mman
+ libc.include.sys_syscall
+ libc.src.__support.OSUtil.osutil
+ libc.src.errno.errno
+)
+
add_entrypoint_object(
munmap
SRCS
diff --git a/libc/src/sys/mman/linux/mremap.cpp b/libc/src/sys/mman/linux/mremap.cpp
new file mode 100644
index 00000000000000..38bcfce833d3d9
--- /dev/null
+++ b/libc/src/sys/mman/linux/mremap.cpp
@@ -0,0 +1,45 @@
+//===---------- Linux implementation of the POSIX mremap 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/mman/mremap.h"
+
+#include "src/__support/OSUtil/syscall.h" // For internal syscall function.
+#include "src/__support/common.h"
+
+#include "src/__support/macros/config.h"
+#include "src/errno/libc_errno.h"
+#include <linux/param.h> // For EXEC_PAGESIZE.
+#include <stdarg.h>
+#include <sys/syscall.h> // For syscall numbers.
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(void *, mremap,
+ (void *old_address, size_t old_size, size_t new_size,
+ int flags, ... /* void *new_address */)) {
+
+ long ret = 0;
+ void *new_address = nullptr;
+ if (flags & MREMAP_FIXED) {
+ va_list varargs;
+ va_start(varargs, flags);
+ new_address = va_arg(varargs, void *);
+ va_end(varargs);
+ }
+ ret = LIBC_NAMESPACE::syscall_impl<long>(SYS_mremap, old_address, old_size,
+ new_size, flags, new_address);
+
+ if (ret < 0 && ret > -EXEC_PAGESIZE) {
+ libc_errno = static_cast<int>(-ret);
+ return MAP_FAILED;
+ }
+
+ return reinterpret_cast<void *>(ret);
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/sys/mman/mremap.h b/libc/src/sys/mman/mremap.h
new file mode 100644
index 00000000000000..208946bc58a2e3
--- /dev/null
+++ b/libc/src/sys/mman/mremap.h
@@ -0,0 +1,22 @@
+//===-- Implementation header for mremap 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_MMAN_MREMAP_H
+#define LLVM_LIBC_SRC_SYS_MMAN_MREMAP_H
+
+#include "src/__support/macros/config.h"
+#include <sys/mman.h> // For size_t and off_t
+
+namespace LIBC_NAMESPACE_DECL {
+
+void *mremap(void *old_address, size_t old_size, size_t new_size, int flags,
+ ... /* void *new_address */);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_MMAN_MREMAP_H
diff --git a/libc/test/src/sys/mman/linux/CMakeLists.txt b/libc/test/src/sys/mman/linux/CMakeLists.txt
index 69263986cc574c..44ed11aadfe8b7 100644
--- a/libc/test/src/sys/mman/linux/CMakeLists.txt
+++ b/libc/test/src/sys/mman/linux/CMakeLists.txt
@@ -14,6 +14,21 @@ add_libc_unittest(
libc.test.UnitTest.ErrnoSetterMatcher
)
+add_libc_unittest(
+ mremap_test
+ SUITE
+ libc_sys_mman_unittests
+ SRCS
+ mremap_test.cpp
+ DEPENDS
+ libc.include.sys_mman
+ libc.src.errno.errno
+ libc.src.sys.mman.mmap
+ libc.src.sys.mman.mremap
+ libc.src.sys.mman.munmap
+ libc.test.UnitTest.ErrnoSetterMatcher
+)
+
if (NOT LLVM_USE_SANITIZER)
add_libc_unittest(
mprotect_test
diff --git a/libc/test/src/sys/mman/linux/mremap_test.cpp b/libc/test/src/sys/mman/linux/mremap_test.cpp
new file mode 100644
index 00000000000000..12e4485588421d
--- /dev/null
+++ b/libc/test/src/sys/mman/linux/mremap_test.cpp
@@ -0,0 +1,68 @@
+//===-- Unittests for mremap ----------------------------------------------===//
+//
+// 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/mman/mmap.h"
+#include "src/sys/mman/mremap.h"
+#include "src/sys/mman/munmap.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/Test.h"
+
+#include <sys/mman.h>
+
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Fails;
+using LIBC_NAMESPACE::testing::ErrnoSetterMatcher::Succeeds;
+
+TEST(LlvmLibcMremapTest, NoError) {
+ size_t initial_size = 128;
+ size_t new_size = 256;
+ LIBC_NAMESPACE::libc_errno = 0;
+
+ // Allocate memory using mmap.
+ void *addr =
+ LIBC_NAMESPACE::mmap(nullptr, initial_size, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ ASSERT_ERRNO_SUCCESS();
+ EXPECT_NE(addr, MAP_FAILED);
+
+ int *array = reinterpret_cast<int *>(addr);
+ // Writing to the memory should not crash the test.
+ array[0] = 123;
+ EXPECT_EQ(array[0], 123);
+
+ // Re-map the memory using mremap with an increased size.
+ void *new_addr =
+ LIBC_NAMESPACE::mremap(addr, initial_size, new_size, MREMAP_MAYMOVE);
+ ASSERT_ERRNO_SUCCESS();
+ EXPECT_NE(new_addr, MAP_FAILED);
+ EXPECT_EQ(reinterpret_cast<int *>(new_addr)[0],
+ 123); // Verify data is preserved.
+
+ // Clean up memory by unmapping it.
+ EXPECT_THAT(LIBC_NAMESPACE::munmap(new_addr, new_size), Succeeds());
+}
+
+TEST(LlvmLibcMremapTest, Error_InvalidSize) {
+ size_t initial_size = 128;
+ LIBC_NAMESPACE::libc_errno = 0;
+
+ // Allocate memory using mmap.
+ void *addr =
+ LIBC_NAMESPACE::mmap(nullptr, initial_size, PROT_READ | PROT_WRITE,
+ MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ ASSERT_ERRNO_SUCCESS();
+ EXPECT_NE(addr, MAP_FAILED);
+
+ // Attempt to re-map the memory with an invalid new size (0).
+ void *new_addr =
+ LIBC_NAMESPACE::mremap(addr, initial_size, 0, MREMAP_MAYMOVE);
+ EXPECT_THAT(new_addr, Fails(EINVAL, MAP_FAILED));
+
+ // Clean up the original mapping.
+ EXPECT_THAT(LIBC_NAMESPACE::munmap(addr, initial_size), Succeeds());
+}
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