glibc/sysdeps/unix/sysv/linux/alpha/brk.S
Roland McGrath d663482017 Wed May 29 00:57:37 1996 David Mosberger-Tang <davidm@azstarnet.com>
* sysdeps/unix/bsd/osf/alpha/brk.S,
 	sysdeps/unix/sysv/linux/alpha/brk.S (__curbrk): Store the entire
 	break value, not just the low 32 bits to accomodate large
 	memories.
Tue May 28 10:46:04 1996  Richard Henderson  <rth@tamu.edu>

	* sysdeps/unix/sysv/linux/alpha/brk.S: Rather than attempt to
	dynamically resolve _end for initializing __curbrk, support the
	brk(0) query idiom.
1996-06-02 18:48:36 +00:00

54 lines
1.5 KiB
ArmAsm

/* Copyright (C) 1993, 1995 Free Software Foundation, Inc.
Contributed by Brendan Kehoe (brendan@zen.org).
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
/* __brk is a special syscall under Linux since it never returns an
error. Instead, the error condition is indicated by returning the old
break value (instead of the new, requested one). */
#include <sysdep.h>
#include <errnos.h>
.comm __curbrk, 8
.text
LEAF(__brk, 0)
ldgp gp, 0(t12)
.prologue 1
ldi v0, __NR_brk
call_pal PAL_callsys
/* Correctly handle the brk(0) query case. */
cmoveq a0, v0, a0
subq a0, v0, t0
bne t0, error
/* Update __curbrk and return cleanly. */
stq a0, __curbrk
mov zero, v0
ret
/* What a horrible way to die. */
error: ldi v0, ENOMEM
jmp zero, syscall_error
END(__brk)
weak_alias (__brk, brk)