glibc/sysdeps/unix/sysv/linux/alpha/syscall.S
Siddhesh Poyarekar 30891f35fa Remove "Contributed by" lines
We stopped adding "Contributed by" or similar lines in sources in 2012
in favour of git logs and keeping the Contributors section of the
glibc manual up to date.  Removing these lines makes the license
header a bit more consistent across files and also removes the
possibility of error in attribution when license blocks or files are
copied across since the contributed-by lines don't actually reflect
reality in those cases.

Move all "Contributed by" and similar lines (Written by, Test by,
etc.) into a new file CONTRIBUTED-BY to retain record of these
contributions.  These contributors are also mentioned in
manual/contrib.texi, so we just maintain this additional record as a
courtesy to the earlier developers.

The following scripts were used to filter a list of files to edit in
place and to clean up the CONTRIBUTED-BY file respectively.  These
were not added to the glibc sources because they're not expected to be
of any use in future given that this is a one time task:

https://gist.github.com/siddhesh/b5ecac94eabfd72ed2916d6d8157e7dc
https://gist.github.com/siddhesh/15ea1f5e435ace9774f485030695ee02

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2021-09-03 22:06:44 +05:30

70 lines
2.1 KiB
ArmAsm

/* Copyright (C) 1996-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library. If not, see
<https://www.gnu.org/licenses/>. */
#include <sysdep.h>
/*
* This is for COMPATIBILITY with Linux/x86 only. Linux/Alpha system
* calls return an error indication in a3. This allows arbitrary 64bit
* values to be returned in v0 (because negative values are not
* mistaken as error numbers). However, C allows only one value to
* be returned, so the interface below folds the error indication passed in
* a3 back into v0: it sets v0 to -errno if an error occurs. Thus,
* no negative 64bit numbers can be returned. To avoid this problem,
* use assembly stubs wherever possible/convenient.
*
* Usage:
*
* long syscall(syscall_number, arg1, arg2, arg3, arg4, arg5, arg6)
*
* syscall_number = the index of the system call we're invoking
* arg1-arg6 = up to 6 integer arguments to the system call
*
* We need to do some arg shifting: the kernel expects the
* syscall number in v0 and the first six args in a0-a5.
*
*/
LEAF(__syscall, 0)
#ifdef PROF
ldgp gp, 0(pv)
.set noat
lda AT, _mcount
jsr AT, (AT), _mcount
.set at
.prologue 1
#else
.prologue 0
#endif
mov a0, v0 /* Syscall number -> v0 */
mov a1, a0 /* arg1-arg5 -> a0-a4 */
mov a2, a1
mov a3, a2
mov a4, a3
mov a5, a4
ldq a5,0(sp) /* arg6 -> a5 */
call_pal PAL_callsys /* Invoke system call */
bne a3, SYSCALL_ERROR_LABEL
ret
PSEUDO_END(__syscall)
weak_alias (__syscall, syscall)