diff options
Diffstat (limited to 'libc/sysdeps/linux/alpha/brk.S')
-rw-r--r-- | libc/sysdeps/linux/alpha/brk.S | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/alpha/brk.S b/libc/sysdeps/linux/alpha/brk.S new file mode 100644 index 000000000..aa8db2ba9 --- /dev/null +++ b/libc/sysdeps/linux/alpha/brk.S @@ -0,0 +1,87 @@ +/* Copyright (C) 1993, 1995, 1996, 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Brendan Kehoe <brendan@zen.org>, 1993. + + 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, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 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 <features.h> +#define _ERRNO_H +#include <bits/errno.h> + +#ifdef PIC +.section .bss + .align 3 + .globl __curbrk +__curbrk: .skip 8 + .type __curbrk,@object + .size __curbrk,8 +#else +.comm __curbrk, 8 +#endif + + .text +.globl __brk; +.align 3; +.ent __brk , 0; + +__brk: + .frame $30 , 8 , $26 + ldgp $29, 0($27) + subq $30, 8, $30 +#ifdef PROF + .set noat + lda AT, _mcount + jsr AT, (AT), _mcount + .set at +#endif + .prologue 1 + + /* Save the requested brk across the system call. */ + stq $16, 0($30) + + ldiq $0, __NR_brk + call_pal 131 + + ldq $16, 0($30) + + /* Be prepared for an OSF-style brk. */ + bne $19, $err1 + beq $0, $ok + + /* Correctly handle the brk(0) query case. */ + cmoveq $16, $0, $16 + xor $16, $0, $1 + bne $1, $err0 + + /* Update __curbrk and return cleanly. */ + mov $31, $0 +$ok: stq $16, __curbrk + addq $30, 8, $30 + ret + + /* What a horrible way to die. */ +$err0: ldi $0, ENOMEM +$err1: addq $30, 8, $30 + jmp $31, __syscall_error + + .end __brk + +.weak brk; + brk = __brk |