xref: /llvm-project/libc/src/unistd/linux/syscall.cpp (revision 5ff3ff33ff930e4ec49da7910612d8a41eb068cb)
11801c356SMichael Jones //===-- Linux implementation of syscall -----------------------------------===//
21801c356SMichael Jones //
31801c356SMichael Jones // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
41801c356SMichael Jones // See https://llvm.org/LICENSE.txt for license information.
51801c356SMichael Jones // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
61801c356SMichael Jones //
71801c356SMichael Jones //===----------------------------------------------------------------------===//
81801c356SMichael Jones 
91801c356SMichael Jones #include "src/unistd/syscall.h"
101801c356SMichael Jones 
111801c356SMichael Jones #include "src/__support/OSUtil/syscall.h" // For internal syscall function.
121801c356SMichael Jones #include "src/__support/common.h"
131801c356SMichael Jones 
14*5ff3ff33SPetr Hosek #include "src/__support/macros/config.h"
15803437dbSMichael Jones #include "src/errno/libc_errno.h"
161801c356SMichael Jones #include <stdarg.h>
171801c356SMichael Jones 
18*5ff3ff33SPetr Hosek namespace LIBC_NAMESPACE_DECL {
191801c356SMichael Jones 
20d4041301Salfredfo LLVM_LIBC_FUNCTION(long, __llvm_libc_syscall,
211801c356SMichael Jones                    (long number, long arg1, long arg2, long arg3, long arg4,
221801c356SMichael Jones                     long arg5, long arg6)) {
23b6bc9d72SGuillaume Chatelet   long ret = LIBC_NAMESPACE::syscall_impl<long>(number, arg1, arg2, arg3, arg4,
24f0a3954eSMichael Jones                                                 arg5, arg6);
251801c356SMichael Jones   // Syscalls may return large positive values that overflow, but will never
261801c356SMichael Jones   // return values between -4096 and -1
271801c356SMichael Jones   if (static_cast<unsigned long>(ret) > -4096UL) {
28f0a3954eSMichael Jones     libc_errno = static_cast<int>(-ret);
291801c356SMichael Jones     return -1;
301801c356SMichael Jones   }
311801c356SMichael Jones   return ret;
321801c356SMichael Jones }
331801c356SMichael Jones 
34*5ff3ff33SPetr Hosek } // namespace LIBC_NAMESPACE_DECL
35