1 //===-- Linux implementation of syscall -----------------------------------===// 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/unistd/syscall.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 <stdarg.h> 17 18 namespace LIBC_NAMESPACE_DECL { 19 20 LLVM_LIBC_FUNCTION(long, __llvm_libc_syscall, 21 (long number, long arg1, long arg2, long arg3, long arg4, 22 long arg5, long arg6)) { 23 long ret = LIBC_NAMESPACE::syscall_impl<long>(number, arg1, arg2, arg3, arg4, 24 arg5, arg6); 25 // Syscalls may return large positive values that overflow, but will never 26 // return values between -4096 and -1 27 if (static_cast<unsigned long>(ret) > -4096UL) { 28 libc_errno = static_cast<int>(-ret); 29 return -1; 30 } 31 return ret; 32 } 33 34 } // namespace LIBC_NAMESPACE_DECL 35