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-exception 6 // 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/macros/config.h" 15 #include "src/errno/libc_errno.h" 16 #include <linux/param.h> // For EXEC_PAGESIZE. 17 #include <stdarg.h> 18 #include <sys/syscall.h> // For syscall numbers. 19 20 namespace LIBC_NAMESPACE_DECL { 21 22 LLVM_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_DECL 46