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-rw-r--r--libc/sysdeps/linux/alpha/brk.S87
1 files changed, 87 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/alpha/brk.S b/libc/sysdeps/linux/alpha/brk.S
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+++ 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