| blob | e04642781917b2be3742388e6cbc1c608e8fb842 |
1 /*
2 * Signal trampolines for 32 bits processes in a ppc64 kernel for
3 * use in the vDSO
4 *
5 * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), IBM Corp.
6 * Copyright (C) 2004 Alan Modra (amodra@au.ibm.com)), IBM Corp.
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13 #include <linux/config.h>
14 #include <asm/processor.h>
15 #include <asm/ppc_asm.h>
16 #include <asm/unistd.h>
17 #include <asm/vdso.h>
19 .text
21 /* The nop here is a hack. The dwarf2 unwind routines subtract 1 from
22 the return address to get an address in the middle of the presumed
23 call instruction. Since we don't have a call here, we artifically
24 extend the range covered by the unwind info by adding a nop before
25 the real start. */
26 nop
27 V_FUNCTION_BEGIN(__kernel_sigtramp32)
28 .Lsig_start = . - 4
29 li r0,__NR_sigreturn
30 sc
31 .Lsig_end:
32 V_FUNCTION_END(__kernel_sigtramp32)
34 .Lsigrt_start:
35 nop
36 V_FUNCTION_BEGIN(__kernel_sigtramp_rt32)
37 li r0,__NR_rt_sigreturn
38 sc
39 .Lsigrt_end:
40 V_FUNCTION_END(__kernel_sigtramp_rt32)
42 .section .eh_frame,"a",@progbits
44 /* Register r1 can be found at offset 4 of a pt_regs structure.
45 A pointer to the pt_regs is stored in memory at the old sp plus PTREGS. */
46 #define cfa_save \
47 .byte 0x0f; /* DW_CFA_def_cfa_expression */ \
48 .uleb128 9f - 1f; /* length */ \
49 1: \
50 .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \
51 .byte 0x06; /* DW_OP_deref */ \
52 .byte 0x23; .uleb128 RSIZE; /* DW_OP_plus_uconst */ \
53 .byte 0x06; /* DW_OP_deref */ \
54 9:
56 /* Register REGNO can be found at offset OFS of a pt_regs structure.
57 A pointer to the pt_regs is stored in memory at the old sp plus PTREGS. */
58 #define rsave(regno, ofs) \
59 .byte 0x10; /* DW_CFA_expression */ \
60 .uleb128 regno; /* regno */ \
61 .uleb128 9f - 1f; /* length */ \
62 1: \
63 .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \
64 .byte 0x06; /* DW_OP_deref */ \
65 .ifne ofs; \
66 .byte 0x23; .uleb128 ofs; /* DW_OP_plus_uconst */ \
67 .endif; \
68 9:
70 /* If msr bit 1<<25 is set, then VMX register REGNO is at offset REGNO*16
71 of the VMX reg struct. The VMX reg struct is at offset VREGS of
72 the pt_regs struct. This macro is for REGNO == 0, and contains
73 'subroutines' that the other macros jump to. */
74 #define vsave_msr0(regno) \
75 .byte 0x10; /* DW_CFA_expression */ \
76 .uleb128 regno + 77; /* regno */ \
77 .uleb128 9f - 1f; /* length */ \
78 1: \
79 .byte 0x30 + regno; /* DW_OP_lit0 */ \
80 2: \
81 .byte 0x40; /* DW_OP_lit16 */ \
82 .byte 0x1e; /* DW_OP_mul */ \
83 3: \
84 .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \
85 .byte 0x06; /* DW_OP_deref */ \
86 .byte 0x12; /* DW_OP_dup */ \
87 .byte 0x23; /* DW_OP_plus_uconst */ \
88 .uleb128 33*RSIZE; /* msr offset */ \
89 .byte 0x06; /* DW_OP_deref */ \
90 .byte 0x0c; .long 1 << 25; /* DW_OP_const4u */ \
91 .byte 0x1a; /* DW_OP_and */ \
92 .byte 0x12; /* DW_OP_dup, ret 0 if bra taken */ \
93 .byte 0x30; /* DW_OP_lit0 */ \
94 .byte 0x29; /* DW_OP_eq */ \
95 .byte 0x28; .short 0x7fff; /* DW_OP_bra to end */ \
96 .byte 0x13; /* DW_OP_drop, pop the 0 */ \
97 .byte 0x23; .uleb128 VREGS; /* DW_OP_plus_uconst */ \
98 .byte 0x22; /* DW_OP_plus */ \
99 .byte 0x2f; .short 0x7fff; /* DW_OP_skip to end */ \
100 9:
102 /* If msr bit 1<<25 is set, then VMX register REGNO is at offset REGNO*16
103 of the VMX reg struct. REGNO is 1 thru 31. */
104 #define vsave_msr1(regno) \
105 .byte 0x10; /* DW_CFA_expression */ \
106 .uleb128 regno + 77; /* regno */ \
107 .uleb128 9f - 1f; /* length */ \
108 1: \
109 .byte 0x30 + regno; /* DW_OP_lit n */ \
110 .byte 0x2f; .short 2b - 9f; /* DW_OP_skip */ \
111 9:
113 /* If msr bit 1<<25 is set, then VMX register REGNO is at offset OFS of
114 the VMX save block. */
115 #define vsave_msr2(regno, ofs) \
116 .byte 0x10; /* DW_CFA_expression */ \
117 .uleb128 regno + 77; /* regno */ \
118 .uleb128 9f - 1f; /* length */ \
119 1: \
120 .byte 0x0a; .short ofs; /* DW_OP_const2u */ \
121 .byte 0x2f; .short 3b - 9f; /* DW_OP_skip */ \
122 9:
124 /* VMX register REGNO is at offset OFS of the VMX save area. */
125 #define vsave(regno, ofs) \
126 .byte 0x10; /* DW_CFA_expression */ \
127 .uleb128 regno + 77; /* regno */ \
128 .uleb128 9f - 1f; /* length */ \
129 1: \
130 .byte 0x71; .sleb128 PTREGS; /* DW_OP_breg1 */ \
131 .byte 0x06; /* DW_OP_deref */ \
132 .byte 0x23; .uleb128 VREGS; /* DW_OP_plus_uconst */ \
133 .byte 0x23; .uleb128 ofs; /* DW_OP_plus_uconst */ \
134 9:
136 /* This is where the pt_regs pointer can be found on the stack. */
137 #define PTREGS 64+28
139 /* Size of regs. */
140 #define RSIZE 4
142 /* This is the offset of the VMX regs. */
143 #define VREGS 48*RSIZE+34*8
145 /* Describe where general purpose regs are saved. */
146 #define EH_FRAME_GEN \
147 cfa_save; \
148 rsave ( 0, 0*RSIZE); \
149 rsave ( 2, 2*RSIZE); \
150 rsave ( 3, 3*RSIZE); \
151 rsave ( 4, 4*RSIZE); \
152 rsave ( 5, 5*RSIZE); \
153 rsave ( 6, 6*RSIZE); \
154 rsave ( 7, 7*RSIZE); \
155 rsave ( 8, 8*RSIZE); \
156 rsave ( 9, 9*RSIZE); \
157 rsave (10, 10*RSIZE); \
158 rsave (11, 11*RSIZE); \
159 rsave (12, 12*RSIZE); \
160 rsave (13, 13*RSIZE); \
161 rsave (14, 14*RSIZE); \
162 rsave (15, 15*RSIZE); \
163 rsave (16, 16*RSIZE); \
164 rsave (17, 17*RSIZE); \
165 rsave (18, 18*RSIZE); \
166 rsave (19, 19*RSIZE); \
167 rsave (20, 20*RSIZE); \
168 rsave (21, 21*RSIZE); \
169 rsave (22, 22*RSIZE); \
170 rsave (23, 23*RSIZE); \
171 rsave (24, 24*RSIZE); \
172 rsave (25, 25*RSIZE); \
173 rsave (26, 26*RSIZE); \
174 rsave (27, 27*RSIZE); \
175 rsave (28, 28*RSIZE); \
176 rsave (29, 29*RSIZE); \
177 rsave (30, 30*RSIZE); \
178 rsave (31, 31*RSIZE); \
179 rsave (67, 32*RSIZE); /* ap, used as temp for nip */ \
180 rsave (65, 36*RSIZE); /* lr */ \
181 rsave (70, 38*RSIZE) /* cr */
183 /* Describe where the FP regs are saved. */
184 #define EH_FRAME_FP \
185 rsave (32, 48*RSIZE + 0*8); \
186 rsave (33, 48*RSIZE + 1*8); \
187 rsave (34, 48*RSIZE + 2*8); \
188 rsave (35, 48*RSIZE + 3*8); \
189 rsave (36, 48*RSIZE + 4*8); \
190 rsave (37, 48*RSIZE + 5*8); \
191 rsave (38, 48*RSIZE + 6*8); \
192 rsave (39, 48*RSIZE + 7*8); \
193 rsave (40, 48*RSIZE + 8*8); \
194 rsave (41, 48*RSIZE + 9*8); \
195 rsave (42, 48*RSIZE + 10*8); \
196 rsave (43, 48*RSIZE + 11*8); \
197 rsave (44, 48*RSIZE + 12*8); \
198 rsave (45, 48*RSIZE + 13*8); \
199 rsave (46, 48*RSIZE + 14*8); \
200 rsave (47, 48*RSIZE + 15*8); \
201 rsave (48, 48*RSIZE + 16*8); \
202 rsave (49, 48*RSIZE + 17*8); \
203 rsave (50, 48*RSIZE + 18*8); \
204 rsave (51, 48*RSIZE + 19*8); \
205 rsave (52, 48*RSIZE + 20*8); \
206 rsave (53, 48*RSIZE + 21*8); \
207 rsave (54, 48*RSIZE + 22*8); \
208 rsave (55, 48*RSIZE + 23*8); \
209 rsave (56, 48*RSIZE + 24*8); \
210 rsave (57, 48*RSIZE + 25*8); \
211 rsave (58, 48*RSIZE + 26*8); \
212 rsave (59, 48*RSIZE + 27*8); \
213 rsave (60, 48*RSIZE + 28*8); \
214 rsave (61, 48*RSIZE + 29*8); \
215 rsave (62, 48*RSIZE + 30*8); \
216 rsave (63, 48*RSIZE + 31*8)
218 /* Describe where the VMX regs are saved. */
219 #ifdef CONFIG_ALTIVEC
220 #define EH_FRAME_VMX \
221 vsave_msr0 ( 0); \
222 vsave_msr1 ( 1); \
223 vsave_msr1 ( 2); \
224 vsave_msr1 ( 3); \
225 vsave_msr1 ( 4); \
226 vsave_msr1 ( 5); \
227 vsave_msr1 ( 6); \
228 vsave_msr1 ( 7); \
229 vsave_msr1 ( 8); \
230 vsave_msr1 ( 9); \
231 vsave_msr1 (10); \
232 vsave_msr1 (11); \
233 vsave_msr1 (12); \
234 vsave_msr1 (13); \
235 vsave_msr1 (14); \
236 vsave_msr1 (15); \
237 vsave_msr1 (16); \
238 vsave_msr1 (17); \
239 vsave_msr1 (18); \
240 vsave_msr1 (19); \
241 vsave_msr1 (20); \
242 vsave_msr1 (21); \
243 vsave_msr1 (22); \
244 vsave_msr1 (23); \
245 vsave_msr1 (24); \
246 vsave_msr1 (25); \
247 vsave_msr1 (26); \
248 vsave_msr1 (27); \
249 vsave_msr1 (28); \
250 vsave_msr1 (29); \
251 vsave_msr1 (30); \
252 vsave_msr1 (31); \
253 vsave_msr2 (33, 32*16+12); \
254 vsave (32, 32*16)
255 #else
256 #define EH_FRAME_VMX
257 #endif
259 .Lcie:
260 .long .Lcie_end - .Lcie_start
261 .Lcie_start:
262 .long 0 /* CIE ID */
263 .byte 1 /* Version number */
264 .string "zR" /* NUL-terminated augmentation string */
265 .uleb128 4 /* Code alignment factor */
266 .sleb128 -4 /* Data alignment factor */
267 .byte 67 /* Return address register column, ap */
268 .uleb128 1 /* Augmentation value length */
269 .byte 0x1b /* DW_EH_PE_pcrel | DW_EH_PE_sdata4. */
270 .byte 0x0c,1,0 /* DW_CFA_def_cfa: r1 ofs 0 */
271 .balign 4
272 .Lcie_end:
274 .long .Lfde0_end - .Lfde0_start
275 .Lfde0_start:
276 .long .Lfde0_start - .Lcie /* CIE pointer. */
277 .long .Lsig_start - . /* PC start, length */
278 .long .Lsig_end - .Lsig_start
279 .uleb128 0 /* Augmentation */
280 EH_FRAME_GEN
281 EH_FRAME_FP
282 EH_FRAME_VMX
283 .balign 4
284 .Lfde0_end:
286 /* We have a different stack layout for rt_sigreturn. */
287 #undef PTREGS
288 #define PTREGS 64+16+128+20+28
290 .long .Lfde1_end - .Lfde1_start
291 .Lfde1_start:
292 .long .Lfde1_start - .Lcie /* CIE pointer. */
293 .long .Lsigrt_start - . /* PC start, length */
294 .long .Lsigrt_end - .Lsigrt_start
295 .uleb128 0 /* Augmentation */
296 EH_FRAME_GEN
297 EH_FRAME_FP
298 EH_FRAME_VMX
299 .balign 4
300 .Lfde1_end: