185c70da7SMichael Jones //===---------- Linux implementation of the POSIX posix_madvise function --===// 285c70da7SMichael Jones // 385c70da7SMichael Jones // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 485c70da7SMichael Jones // See https://llvm.org/LICENSE.txt for license information. 585c70da7SMichael Jones // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 685c70da7SMichael Jones // 785c70da7SMichael Jones //===----------------------------------------------------------------------===// 885c70da7SMichael Jones 985c70da7SMichael Jones #include "src/sys/mman/posix_madvise.h" 1085c70da7SMichael Jones 1185c70da7SMichael Jones #include "src/__support/OSUtil/syscall.h" // For internal syscall function. 1285c70da7SMichael Jones #include "src/__support/common.h" 13*5ff3ff33SPetr Hosek #include "src/__support/macros/config.h" 1485c70da7SMichael Jones 1585c70da7SMichael Jones #include <sys/syscall.h> // For syscall numbers. 1685c70da7SMichael Jones 17*5ff3ff33SPetr Hosek namespace LIBC_NAMESPACE_DECL { 1885c70da7SMichael Jones 1985c70da7SMichael Jones // This function is currently linux only. It has to be refactored suitably if 2085c70da7SMichael Jones // posix_madvise is to be supported on non-linux operating systems also. 2185c70da7SMichael Jones LLVM_LIBC_FUNCTION(int, posix_madvise, (void *addr, size_t size, int advice)) { 2285c70da7SMichael Jones // POSIX_MADV_DONTNEED does nothing because the default MADV_DONTNEED may 2385c70da7SMichael Jones // cause data loss, which the posix madvise does not allow. 2485c70da7SMichael Jones if (advice == POSIX_MADV_DONTNEED) { 2585c70da7SMichael Jones return 0; 2685c70da7SMichael Jones } 27b6bc9d72SGuillaume Chatelet int ret = LIBC_NAMESPACE::syscall_impl<int>( 281801c356SMichael Jones SYS_madvise, reinterpret_cast<long>(addr), size, advice); 29f0a3954eSMichael Jones return ret < 0 ? -ret : 0; 3085c70da7SMichael Jones } 3185c70da7SMichael Jones 32*5ff3ff33SPetr Hosek } // namespace LIBC_NAMESPACE_DECL 33