Gitiles
Code Review Sign In
review.shift-gmbh.com / SHIFTPHONES / mainline / linux / d0f38f9130b7683e39611c5a661349e301ee43c8 / . / arch / arm64 / kernel / kuser32.S
blob: 63c48ffdf230125dedea62d631b3067f4d7a28e1 [file] [log] [blame]
Will Deacon3dd681d2012-03-05 11:49:32 +0000[diff] [blame]1/*
2 * Low-level user helpers placed in the vectors page for AArch32.
3 * Based on the kuser helpers in arch/arm/kernel/entry-armv.S.
4 *
5 * Copyright (C) 2005-2011 Nicolas Pitre <nico@fluxnic.net>
6 * Copyright (C) 2012 ARM Ltd.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 *
20 *
21 * AArch32 user helpers.
22 *
23 * Each segment is 32-byte aligned and will be moved to the top of the high
24 * vector page. New segments (if ever needed) must be added in front of
25 * existing ones. This mechanism should be used only for things that are
26 * really small and justified, and not be abused freely.
27 *
28 * See Documentation/arm/kernel_user_helpers.txt for formal definitions.
29 */
Matthew Leacha1d5eba2013-10-11 14:52:14 +0100[diff] [blame]30
31#include <asm/unistd32.h>
32
Will Deacon3dd681d2012-03-05 11:49:32 +0000[diff] [blame]33 .align 5
34 .globl __kuser_helper_start
35__kuser_helper_start:
36
37__kuser_cmpxchg64: // 0xffff0f60
38 .inst 0xe92d00f0 // push {r4, r5, r6, r7}
39 .inst 0xe1c040d0 // ldrd r4, r5, [r0]
40 .inst 0xe1c160d0 // ldrd r6, r7, [r1]
Robin Murphyd0f38f92013-10-07 18:30:34 +0100[diff] [blame^]41 .inst 0xe1b20e9f // 1: ldaexd r0, r1, [r2]
Will Deacon3dd681d2012-03-05 11:49:32 +0000[diff] [blame]42 .inst 0xe0303004 // eors r3, r0, r4
43 .inst 0x00313005 // eoreqs r3, r1, r5
Robin Murphyd0f38f92013-10-07 18:30:34 +0100[diff] [blame^]44 .inst 0x01a23e96 // stlexdeq r3, r6, [r2]
Will Deacon3dd681d2012-03-05 11:49:32 +0000[diff] [blame]45 .inst 0x03330001 // teqeq r3, #1
46 .inst 0x0afffff9 // beq 1b
Will Deacon3dd681d2012-03-05 11:49:32 +0000[diff] [blame]47 .inst 0xe2730000 // rsbs r0, r3, #0
48 .inst 0xe8bd00f0 // pop {r4, r5, r6, r7}
49 .inst 0xe12fff1e // bx lr
50
51 .align 5
52__kuser_memory_barrier: // 0xffff0fa0
Robin Murphyd0f38f92013-10-07 18:30:34 +0100[diff] [blame^]53 .inst 0xf57ff05b // dmb ish
Will Deacon3dd681d2012-03-05 11:49:32 +0000[diff] [blame]54 .inst 0xe12fff1e // bx lr
55
56 .align 5
57__kuser_cmpxchg: // 0xffff0fc0
Robin Murphyd0f38f92013-10-07 18:30:34 +0100[diff] [blame^]58 .inst 0xe1923e9f // 1: ldaex r3, [r2]
Will Deacon3dd681d2012-03-05 11:49:32 +0000[diff] [blame]59 .inst 0xe0533000 // subs r3, r3, r0
Robin Murphyd0f38f92013-10-07 18:30:34 +0100[diff] [blame^]60 .inst 0x01823e91 // stlexeq r3, r1, [r2]
Will Deacon3dd681d2012-03-05 11:49:32 +0000[diff] [blame]61 .inst 0x03330001 // teqeq r3, #1
62 .inst 0x0afffffa // beq 1b
63 .inst 0xe2730000 // rsbs r0, r3, #0
Robin Murphyd0f38f92013-10-07 18:30:34 +0100[diff] [blame^]64 .inst 0xe12fff1e // bx lr
Will Deacon3dd681d2012-03-05 11:49:32 +0000[diff] [blame]65
66 .align 5
67__kuser_get_tls: // 0xffff0fe0
68 .inst 0xee1d0f70 // mrc p15, 0, r0, c13, c0, 3
69 .inst 0xe12fff1e // bx lr
70 .rep 5
71 .word 0
72 .endr
73
74__kuser_helper_version: // 0xffff0ffc
75 .word ((__kuser_helper_end - __kuser_helper_start) >> 5)
76 .globl __kuser_helper_end
77__kuser_helper_end:
Matthew Leacha1d5eba2013-10-11 14:52:14 +0100[diff] [blame]78
79/*
80 * AArch32 sigreturn code
81 *
82 * For ARM syscalls, the syscall number has to be loaded into r7.
83 * We do not support an OABI userspace.
84 *
85 * For Thumb syscalls, we also pass the syscall number via r7. We therefore
86 * need two 16-bit instructions.
87 */
88 .globl __aarch32_sigret_code_start
89__aarch32_sigret_code_start:
90
91 /*
92 * ARM Code
93 */
94 .byte __NR_compat_sigreturn, 0x70, 0xa0, 0xe3 // mov r7, #__NR_compat_sigreturn
95 .byte __NR_compat_sigreturn, 0x00, 0x00, 0xef // svc #__NR_compat_sigreturn
96
97 /*
98 * Thumb code
99 */
100 .byte __NR_compat_sigreturn, 0x27 // svc #__NR_compat_sigreturn
101 .byte __NR_compat_sigreturn, 0xdf // mov r7, #__NR_compat_sigreturn
102
103 /*
104 * ARM code
105 */
106 .byte __NR_compat_rt_sigreturn, 0x70, 0xa0, 0xe3 // mov r7, #__NR_compat_rt_sigreturn
107 .byte __NR_compat_rt_sigreturn, 0x00, 0x00, 0xef // svc #__NR_compat_rt_sigreturn
108
109 /*
110 * Thumb code
111 */
112 .byte __NR_compat_rt_sigreturn, 0x27 // svc #__NR_compat_rt_sigreturn
113 .byte __NR_compat_rt_sigreturn, 0xdf // mov r7, #__NR_compat_rt_sigreturn
114
115 .globl __aarch32_sigret_code_end
116__aarch32_sigret_code_end: