xref: /netbsd-src/sys/compat/linux32/arch/aarch64/linux32_sigcode.S (revision 90313c06e62e910bf0d1bb24faa9d17dcefd0ab6)
1/*	$NetBSD: linux32_sigcode.S,v 1.2 2024/02/07 04:20:28 msaitoh Exp $	*/
2
3/*-
4 * Copyright (c) 2021 Ryo Shimizu
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
17 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
25 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <machine/asm.h>
30
31RCSID("$NetBSD: linux32_sigcode.S,v 1.2 2024/02/07 04:20:28 msaitoh Exp $")
32
33#include <compat/linux32/linux32_syscall.h>
34
35/*
36 * linux aarch32 Signal trampoline code
37 */
38	.text
39	.section .rodata
40	.align 12
41
42	.global	_C_LABEL(linux32_sigcode)
43_C_LABEL(linux32_sigcode):
44	/* mov r7, #LINUX32_SYS_sigreturn */
45	.word	0xe3a07000 + LINUX32_SYS_sigreturn
46	.word	0xef000000	/* svc 0   */
47	/* NOTREACHED */
48	.word	0xe7f000f0	/* udf #0  */
49
50	.global	_C_LABEL(linux32_rt_sigcode)
51_C_LABEL(linux32_rt_sigcode):
52	/* mov r7, #LINUX32_SYS_rt_sigreturn */
53	.word	0xe3a07000 + LINUX32_SYS_rt_sigreturn
54	.word	0xef000000	/* svc 0   */
55	/* NOTREACHED */
56	.word	0xe7f000f0	/* udf #0  */
57
58/*
59 * linux/arm kuser_helper
60 *   - should be mapped on userspace vaddr 0xffff0f60
61 *   - https://www.kernel.org/doc/Documentation/arm/kernel_user_helpers.txt
62 */
63
64.kuser_helper_pad:
65#define KUSER_HELPER_START	0x00000f60
66	.space	KUSER_HELPER_START - (.kuser_helper_pad - _C_LABEL(linux32_sigcode))
67
68/*
69 * 0xffff0f60
70 * int __kuser_cmpxchg64(const int64_t *oldval, const int64_t *newval, volatile int64_t *ptr);
71 */
72.__kuser_cmpxchg64:
73	.word	0xe92d00f0	/* push {r4, r5, r6, r7}  */
74	.word	0xf57ff05f	/* dmb sy                 */
75	.word	0xe1c040d0	/* ldrd r4, [r0]          */
76	.word	0xe1c160d0	/* ldrd r6, [r1]          */
77	.word	0xe1b20f9f	/* ldrexd r0, [r2]        */
78	.word	0xe0500004	/* subs r0, r0, r4        */
79	.word	0xe0c11005	/* sbc r1, r1, r5         */
80	.word	0xe1900001	/* orrs r0, r0, r1        */
81	.word	0x01a20f96	/* strexdeq r0, r6, [r2]  */
82	.word	0xf57ff05f	/* dmb sy                 */
83	.word	0xe8bd00f0	/* pop {r4, r5, r6, r7}   */
84	.word	0xe12fff1e	/* bx lr                  */
85
86	.align	5
87/*
88 * 0xffff0fa0
89 * void __kuser_memory_barrier(void);
90 */
91.__kuser_memory_barrier:
92	.word	0xf57ff05f	/* dmb sy  */
93	.word	0xe12fff1e	/* bx lr   */
94
95	.align	5
96/*
97 * 0xffff0fc0
98 * int __kuser_cmpxchg(int32_t oldval, int32_t newval, volatile int32_t *ptr);
99 */
100.__kuser_cmpxchg:
101	.word	0xf57ff05f	/* dmb sy                */
102	.word	0xe1923f9f	/* ldrex r3, [r2]        */
103	.word	0xe0530000	/* subs r0, r3, r0       */
104	.word	0x01820f91	/* strexeq r0, r1, [r2]  */
105	.word	0xf57ff05f	/* dmb sy                */
106	.word	0xe12fff1e	/* bx lr                 */
107
108
109	.align	5
110/* 0xffff0fe0 */
111.__kuser_get_tls:
112	.word	0xee1d0f70	/* mrc p15, 0, r0, c13, c0, 3  */
113	.word	0xe12fff1e	/* bx lr                       */
114
115	.align	4
116/* 0xffff0ff0 */
117	.word	0
118/* 0xffff0ff4 */
119	.word	0
120/* 0xffff0ff8 */
121	.word	0
122
123/* 0xffff0ffc */
124.__kuser_helper_version:
125	.word	2
126
127
128	.global	_C_LABEL(linux32_esigcode)
129_C_LABEL(linux32_esigcode):
130