1/* Copyright (C) 2001-2024 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <sysdep.h>
19
20/* Please consult the file sysdeps/unix/sysv/linux/x86-64/sysdep.h for
21 more information about the value -4095 used below. */
22
23/* Usage: long syscall (syscall_number, arg1, arg2, arg3, arg4, arg5, arg6)
24 We need to do some arg shifting, the syscall_number will be in
25 rax. */
26
27
28 .text
29ENTRY (syscall)
30 movq %rdi, %rax /* Syscall number -> rax. */
31 movq %rsi, %rdi /* shift arg1 - arg5. */
32 movq %rdx, %rsi
33 movq %rcx, %rdx
34 movq %r8, %r10
35 movq %r9, %r8
36 movq 8(%rsp),%r9 /* arg6 is on the stack. */
37 syscall /* Do the system call. */
38 cmpq $-4095, %rax /* Check %rax for error. */
39 jae SYSCALL_ERROR_LABEL /* Jump to error handler if error. */
40 ret /* Return to caller. */
41
42PSEUDO_END (syscall)
43

source code of glibc/sysdeps/unix/sysv/linux/x86_64/syscall.S