1/* $OpenBSD: brk.S,v 1.2 2021/10/25 14:38:10 jca Exp $ */ 2/* 3 * Copyright (c) 2021 Dale Rahn <drahn@openbsd.org> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18#include "SYS.h" 19 20 .extern __curbrk 21 .extern _C_LABEL(_end) 22 23 .data 24 .align 3 25__minbrk: 26 .dword _C_LABEL(_end) 27 28 29ENTRY(brk) 30 RETGUARD_SETUP(brk, t6) 31 lla t1, _C_LABEL(__minbrk) 32 ld t5, 0(t1) 33 bgeu a0, t5, .L_brk_call 34 mv a0, t5 35 36.L_brk_call: 37 mv a2, a0 38 lla t1, _C_LABEL(__curbrk) 39 40 li t0, SYS_break 41 ecall 42 43 /* check for error */ 44 beqz t0, .L_brk_ok 45 46 sw a0, TP_OFFSET_ERRNO(tp) 47 li a0, -1 48 j .L_done 49 50 /* update, __curbrk and return */ 51.L_brk_ok: 52 sd a2, 0(t1) 53 li a0, 0 /* # return 0 */ 54.L_done: 55 RETGUARD_CHECK(brk, t6); 56 ret 57END(brk) 58 .weak brk 59