1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * Signal trampolines for 32 bits processes in a ppc64 kernel for
4 * use in the vDSO
5 *
6 * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp.
7 * Copyright (C) 2004 Alan Modra (amodra@au.ibm.com)), IBM Corp.
8 */
9#include <asm/processor.h>
10#include <asm/ppc_asm.h>
11#include <asm/unistd.h>
12#include <asm/vdso.h>
13
14 .text
15
16/* The nop here is a hack. The dwarf2 unwind routines subtract 1 from
17 the return address to get an address in the middle of the presumed
18 call instruction. Since we don't have a call here, we artificially
19 extend the range covered by the unwind info by adding a nop before
20 the real start. */
21 nop
22V_FUNCTION_BEGIN(__kernel_sigtramp32)
23.Lsig_start = . - 4
24 li r0,__NR_sigreturn
25 sc
26.Lsig_end:
27V_FUNCTION_END(__kernel_sigtramp32)
28
29.Lsigrt_start:
30 nop
31V_FUNCTION_BEGIN(__kernel_sigtramp_rt32)
32 li r0,__NR_rt_sigreturn
33 sc
34.Lsigrt_end:
35V_FUNCTION_END(__kernel_sigtramp_rt32)
36
37 .section .eh_frame,"a",@progbits
38
39/* Register r1 can be found at offset 4 of a pt_regs structure.
40 A pointer to the pt_regs is stored in memory at the old sp plus PTREGS. */
41#define cfa_save \
42 .byte 0x0f; /* DW_CFA_def_cfa_expression */ \
43 .uleb128 9f - 1f; /* length */ \
441: \
45 .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \
46 .byte 0x06; /* DW_OP_deref */ \
47 .byte 0x23; .uleb128 RSIZE; /* DW_OP_plus_uconst */ \
48 .byte 0x06; /* DW_OP_deref */ \
499:
50
51/* Register REGNO can be found at offset OFS of a pt_regs structure.
52 A pointer to the pt_regs is stored in memory at the old sp plus PTREGS. */
53#define rsave(regno, ofs) \
54 .byte 0x10; /* DW_CFA_expression */ \
55 .uleb128 regno; /* regno */ \
56 .uleb128 9f - 1f; /* length */ \
571: \
58 .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \
59 .byte 0x06; /* DW_OP_deref */ \
60 .ifne ofs; \
61 .byte 0x23; .uleb128 ofs; /* DW_OP_plus_uconst */ \
62 .endif; \
639:
64
65/* If msr bit 1<<25 is set, then VMX register REGNO is at offset REGNO*16
66 of the VMX reg struct. The VMX reg struct is at offset VREGS of
67 the pt_regs struct. This macro is for REGNO == 0, and contains
68 'subroutines' that the other macros jump to. */
69#define vsave_msr0(regno) \
70 .byte 0x10; /* DW_CFA_expression */ \
71 .uleb128 regno + 77; /* regno */ \
72 .uleb128 9f - 1f; /* length */ \
731: \
74 .byte 0x30 + regno; /* DW_OP_lit0 */ \
752: \
76 .byte 0x40; /* DW_OP_lit16 */ \
77 .byte 0x1e; /* DW_OP_mul */ \
783: \
79 .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \
80 .byte 0x06; /* DW_OP_deref */ \
81 .byte 0x12; /* DW_OP_dup */ \
82 .byte 0x23; /* DW_OP_plus_uconst */ \
83 .uleb128 33*RSIZE; /* msr offset */ \
84 .byte 0x06; /* DW_OP_deref */ \
85 .byte 0x0c; .long 1 << 25; /* DW_OP_const4u */ \
86 .byte 0x1a; /* DW_OP_and */ \
87 .byte 0x12; /* DW_OP_dup, ret 0 if bra taken */ \
88 .byte 0x30; /* DW_OP_lit0 */ \
89 .byte 0x29; /* DW_OP_eq */ \
90 .byte 0x28; .short 0x7fff; /* DW_OP_bra to end */ \
91 .byte 0x13; /* DW_OP_drop, pop the 0 */ \
92 .byte 0x23; .uleb128 VREGS; /* DW_OP_plus_uconst */ \
93 .byte 0x22; /* DW_OP_plus */ \
94 .byte 0x2f; .short 0x7fff; /* DW_OP_skip to end */ \
959:
96
97/* If msr bit 1<<25 is set, then VMX register REGNO is at offset REGNO*16
98 of the VMX reg struct. REGNO is 1 thru 31. */
99#define vsave_msr1(regno) \
100 .byte 0x10; /* DW_CFA_expression */ \
101 .uleb128 regno + 77; /* regno */ \
102 .uleb128 9f - 1f; /* length */ \
1031: \
104 .byte 0x30 + regno; /* DW_OP_lit n */ \
105 .byte 0x2f; .short 2b - 9f; /* DW_OP_skip */ \
1069:
107
108/* If msr bit 1<<25 is set, then VMX register REGNO is at offset OFS of
109 the VMX save block. */
110#define vsave_msr2(regno, ofs) \
111 .byte 0x10; /* DW_CFA_expression */ \
112 .uleb128 regno + 77; /* regno */ \
113 .uleb128 9f - 1f; /* length */ \
1141: \
115 .byte 0x0a; .short ofs; /* DW_OP_const2u */ \
116 .byte 0x2f; .short 3b - 9f; /* DW_OP_skip */ \
1179:
118
119/* VMX register REGNO is at offset OFS of the VMX save area. */
120#define vsave(regno, ofs) \
121 .byte 0x10; /* DW_CFA_expression */ \
122 .uleb128 regno + 77; /* regno */ \
123 .uleb128 9f - 1f; /* length */ \
1241: \
125 .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \
126 .byte 0x06; /* DW_OP_deref */ \
127 .byte 0x23; .uleb128 VREGS; /* DW_OP_plus_uconst */ \
128 .byte 0x23; .uleb128 ofs; /* DW_OP_plus_uconst */ \
1299:
130
131/* This is where the pt_regs pointer can be found on the stack. */
132#define PTREGS 64+28
133
134/* Size of regs. */
135#define RSIZE 4
136
137/* This is the offset of the VMX regs. */
138#define VREGS 48*RSIZE+34*8
139
140/* Describe where general purpose regs are saved. */
141#define EH_FRAME_GEN \
142 cfa_save; \
143 rsave ( 0, 0*RSIZE); \
144 rsave ( 2, 2*RSIZE); \
145 rsave ( 3, 3*RSIZE); \
146 rsave ( 4, 4*RSIZE); \
147 rsave ( 5, 5*RSIZE); \
148 rsave ( 6, 6*RSIZE); \
149 rsave ( 7, 7*RSIZE); \
150 rsave ( 8, 8*RSIZE); \
151 rsave ( 9, 9*RSIZE); \
152 rsave (10, 10*RSIZE); \
153 rsave (11, 11*RSIZE); \
154 rsave (12, 12*RSIZE); \
155 rsave (13, 13*RSIZE); \
156 rsave (14, 14*RSIZE); \
157 rsave (15, 15*RSIZE); \
158 rsave (16, 16*RSIZE); \
159 rsave (17, 17*RSIZE); \
160 rsave (18, 18*RSIZE); \
161 rsave (19, 19*RSIZE); \
162 rsave (20, 20*RSIZE); \
163 rsave (21, 21*RSIZE); \
164 rsave (22, 22*RSIZE); \
165 rsave (23, 23*RSIZE); \
166 rsave (24, 24*RSIZE); \
167 rsave (25, 25*RSIZE); \
168 rsave (26, 26*RSIZE); \
169 rsave (27, 27*RSIZE); \
170 rsave (28, 28*RSIZE); \
171 rsave (29, 29*RSIZE); \
172 rsave (30, 30*RSIZE); \
173 rsave (31, 31*RSIZE); \
174 rsave (67, 32*RSIZE); /* ap, used as temp for nip */ \
175 rsave (65, 36*RSIZE); /* lr */ \
176 rsave (70, 38*RSIZE) /* cr */
177
178/* Describe where the FP regs are saved. */
179#define EH_FRAME_FP \
180 rsave (32, 48*RSIZE + 0*8); \
181 rsave (33, 48*RSIZE + 1*8); \
182 rsave (34, 48*RSIZE + 2*8); \
183 rsave (35, 48*RSIZE + 3*8); \
184 rsave (36, 48*RSIZE + 4*8); \
185 rsave (37, 48*RSIZE + 5*8); \
186 rsave (38, 48*RSIZE + 6*8); \
187 rsave (39, 48*RSIZE + 7*8); \
188 rsave (40, 48*RSIZE + 8*8); \
189 rsave (41, 48*RSIZE + 9*8); \
190 rsave (42, 48*RSIZE + 10*8); \
191 rsave (43, 48*RSIZE + 11*8); \
192 rsave (44, 48*RSIZE + 12*8); \
193 rsave (45, 48*RSIZE + 13*8); \
194 rsave (46, 48*RSIZE + 14*8); \
195 rsave (47, 48*RSIZE + 15*8); \
196 rsave (48, 48*RSIZE + 16*8); \
197 rsave (49, 48*RSIZE + 17*8); \
198 rsave (50, 48*RSIZE + 18*8); \
199 rsave (51, 48*RSIZE + 19*8); \
200 rsave (52, 48*RSIZE + 20*8); \
201 rsave (53, 48*RSIZE + 21*8); \
202 rsave (54, 48*RSIZE + 22*8); \
203 rsave (55, 48*RSIZE + 23*8); \
204 rsave (56, 48*RSIZE + 24*8); \
205 rsave (57, 48*RSIZE + 25*8); \
206 rsave (58, 48*RSIZE + 26*8); \
207 rsave (59, 48*RSIZE + 27*8); \
208 rsave (60, 48*RSIZE + 28*8); \
209 rsave (61, 48*RSIZE + 29*8); \
210 rsave (62, 48*RSIZE + 30*8); \
211 rsave (63, 48*RSIZE + 31*8)
212
213/* Describe where the VMX regs are saved. */
214#ifdef CONFIG_ALTIVEC
215#define EH_FRAME_VMX \
216 vsave_msr0 ( 0); \
217 vsave_msr1 ( 1); \
218 vsave_msr1 ( 2); \
219 vsave_msr1 ( 3); \
220 vsave_msr1 ( 4); \
221 vsave_msr1 ( 5); \
222 vsave_msr1 ( 6); \
223 vsave_msr1 ( 7); \
224 vsave_msr1 ( 8); \
225 vsave_msr1 ( 9); \
226 vsave_msr1 (10); \
227 vsave_msr1 (11); \
228 vsave_msr1 (12); \
229 vsave_msr1 (13); \
230 vsave_msr1 (14); \
231 vsave_msr1 (15); \
232 vsave_msr1 (16); \
233 vsave_msr1 (17); \
234 vsave_msr1 (18); \
235 vsave_msr1 (19); \
236 vsave_msr1 (20); \
237 vsave_msr1 (21); \
238 vsave_msr1 (22); \
239 vsave_msr1 (23); \
240 vsave_msr1 (24); \
241 vsave_msr1 (25); \
242 vsave_msr1 (26); \
243 vsave_msr1 (27); \
244 vsave_msr1 (28); \
245 vsave_msr1 (29); \
246 vsave_msr1 (30); \
247 vsave_msr1 (31); \
248 vsave_msr2 (33, 32*16+12); \
249 vsave (32, 32*16)
250#else
251#define EH_FRAME_VMX
252#endif
253
254.Lcie:
255 .long .Lcie_end - .Lcie_start
256.Lcie_start:
257 .long 0 /* CIE ID */
258 .byte 1 /* Version number */
259 .string "zRS" /* NUL-terminated augmentation string */
260 .uleb128 4 /* Code alignment factor */
261 .sleb128 -4 /* Data alignment factor */
262 .byte 67 /* Return address register column, ap */
263 .uleb128 1 /* Augmentation value length */
264 .byte 0x1b /* DW_EH_PE_pcrel | DW_EH_PE_sdata4. */
265 .byte 0x0c,1,0 /* DW_CFA_def_cfa: r1 ofs 0 */
266 .balign 4
267.Lcie_end:
268
269 .long .Lfde0_end - .Lfde0_start
270.Lfde0_start:
271 .long .Lfde0_start - .Lcie /* CIE pointer. */
272 .long .Lsig_start - . /* PC start, length */
273 .long .Lsig_end - .Lsig_start
274 .uleb128 0 /* Augmentation */
275 EH_FRAME_GEN
276 EH_FRAME_FP
277 EH_FRAME_VMX
278 .balign 4
279.Lfde0_end:
280
281/* We have a different stack layout for rt_sigreturn. */
282#undef PTREGS
283#define PTREGS 64+16+128+20+28
284
285 .long .Lfde1_end - .Lfde1_start
286.Lfde1_start:
287 .long .Lfde1_start - .Lcie /* CIE pointer. */
288 .long .Lsigrt_start - . /* PC start, length */
289 .long .Lsigrt_end - .Lsigrt_start
290 .uleb128 0 /* Augmentation */
291 EH_FRAME_GEN
292 EH_FRAME_FP
293 EH_FRAME_VMX
294 .balign 4
295.Lfde1_end:
296

source code of linux/arch/powerpc/kernel/vdso/sigtramp32.S