46 lines · cpp
1//===---------- Linux implementation of the POSIX mremap function----------===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8 9#include "src/sys/mman/mremap.h"10 11#include "src/__support/OSUtil/syscall.h" // For internal syscall function.12#include "src/__support/common.h"13 14#include "src/__support/libc_errno.h"15#include "src/__support/macros/config.h"16#include <linux/param.h> // For EXEC_PAGESIZE.17#include <stdarg.h>18#include <sys/syscall.h> // For syscall numbers.19 20namespace LIBC_NAMESPACE_DECL {21 22LLVM_LIBC_FUNCTION(void *, mremap,23 (void *old_address, size_t old_size, size_t new_size,24 int flags, ... /* void *new_address */)) {25 26 long ret = 0;27 void *new_address = nullptr;28 if (flags & MREMAP_FIXED) {29 va_list varargs;30 va_start(varargs, flags);31 new_address = va_arg(varargs, void *);32 va_end(varargs);33 }34 ret = LIBC_NAMESPACE::syscall_impl<long>(SYS_mremap, old_address, old_size,35 new_size, flags, new_address);36 37 if (ret < 0 && ret > -EXEC_PAGESIZE) {38 libc_errno = static_cast<int>(-ret);39 return MAP_FAILED;40 }41 42 return reinterpret_cast<void *>(ret);43}44 45} // namespace LIBC_NAMESPACE_DECL46