1/* $OpenBSD: brk.S,v 1.5 2023/12/10 16:45:52 deraadt 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 _end 22 23 .data 24 .align 3 25__minbrk: 26 .dword _end 27 28 29ENTRY_NB(brk) 30 RETGUARD_SETUP(brk, t6) 31 lla t1, __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, __curbrk 39 40 li t0, SYS_break 4199: ecall 42 PINSYSCALL(SYS_break, 99b) 43 44 /* check for error */ 45 beqz t0, .L_brk_ok 46 47 sw a0, TP_OFFSET_ERRNO(tp) 48 li a0, -1 49 j .L_done 50 51 /* update, __curbrk and return */ 52.L_brk_ok: 53 sd a2, 0(t1) 54 li a0, 0 /* # return 0 */ 55.L_done: 56 RETGUARD_CHECK(brk, t6); 57 ret 58END(brk) 59 .weak brk 60