39 lines · cpp
1//===---------- Linux implementation of the prctl 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/prctl/prctl.h"10 11#include "src/__support/OSUtil/syscall.h" // For internal syscall function.12 13#include "src/__support/libc_errno.h"14#include "src/__support/macros/config.h"15#include <sys/syscall.h> // For syscall numbers.16 17namespace LIBC_NAMESPACE_DECL {18 19LLVM_LIBC_FUNCTION(int, prctl,20 (int option, unsigned long arg2, unsigned long arg3,21 unsigned long arg4, unsigned long arg5)) {22 long ret =23 LIBC_NAMESPACE::syscall_impl(SYS_prctl, option, arg2, arg3, arg4, arg5);24 // The manpage states that "... return the nonnegative values described25 // above. All other option values return 0 on success. On error,26 // -1 is returned, and errno is set to indicate the error."27 // According to the kernel implementation28 // (https://github.com/torvalds/linux/blob/bee0e7762ad2c6025b9f5245c040fcc36ef2bde8/kernel/sys.c#L2442),29 // return value from the syscall is set to 0 on default so we do not need to30 // set the value on success manually.31 if (ret < 0) {32 libc_errno = static_cast<int>(-ret);33 return -1;34 }35 return static_cast<int>(ret);36}37 38} // namespace LIBC_NAMESPACE_DECL39