xref: /netbsd-src/external/gpl3/gcc/dist/libgcc/config/sh/linux-unwind.h (revision b7b7574d3bf8eeb51a1fa3977b59142ec6434a55)
1 /* DWARF2 EH unwinding support for SH Linux.
2    Copyright (C) 2004-2013 Free Software Foundation, Inc.
3 
4 This file is part of GCC.
5 
6 GCC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
9 any later version.
10 
11 GCC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 GNU General Public License for more details.
15 
16 Under Section 7 of GPL version 3, you are granted additional
17 permissions described in the GCC Runtime Library Exception, version
18 3.1, as published by the Free Software Foundation.
19 
20 You should have received a copy of the GNU General Public License and
21 a copy of the GCC Runtime Library Exception along with this program;
22 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23 <http://www.gnu.org/licenses/>.  */
24 
25 
26 /* Do code reading to identify a signal frame, and set the frame
27    state data appropriately.  See unwind-dw2.c for the structs.
28    Don't use this at all if inhibit_libc is used.  */
29 
30 #ifndef inhibit_libc
31 
32 #include <signal.h>
33 #include <sys/ucontext.h>
34 #include "insn-constants.h"
35 
36 # if defined (__SH5__)
37 #define SH_DWARF_FRAME_GP0	0
38 #define SH_DWARF_FRAME_FP0	77
39 #define SH_DWARF_FRAME_BT0	68
40 #define SH_DWARF_FRAME_PR_MEDIA	18
41 #define SH_DWARF_FRAME_SR	65
42 #define SH_DWARF_FRAME_FPSCR	76
43 #else
44 #define SH_DWARF_FRAME_GP0	0
45 #define SH_DWARF_FRAME_FP0	25
46 #define SH_DWARF_FRAME_XD0	87
47 #define SH_DWARF_FRAME_PR	17
48 #define SH_DWARF_FRAME_GBR	18
49 #define SH_DWARF_FRAME_MACH	20
50 #define SH_DWARF_FRAME_MACL	21
51 #define SH_DWARF_FRAME_PC	16
52 #define SH_DWARF_FRAME_SR	22
53 #define SH_DWARF_FRAME_FPUL	23
54 #define SH_DWARF_FRAME_FPSCR	24
55 #endif /* defined (__SH5__) */
56 
57 #if defined (__SH5__)
58 
59 #define MD_FALLBACK_FRAME_STATE_FOR shmedia_fallback_frame_state
60 
61 static _Unwind_Reason_Code
62 shmedia_fallback_frame_state (struct _Unwind_Context *context,
63 			      _Unwind_FrameState *fs)
64 {
65   unsigned char *pc = context->ra;
66   struct sigcontext *sc;
67   long new_cfa;
68   int i, r;
69 
70   /* movi 0x10,r9; shori 0x77,r9; trapa	r9; nop (sigreturn)  */
71   /* movi 0x10,r9; shori 0xad,r9; trapa	r9; nop (rt_sigreturn)  */
72   if ((*(unsigned long *) (pc-1)  == 0xcc004090)
73       && (*(unsigned long *) (pc+3)  == 0xc801dc90)
74       && (*(unsigned long *) (pc+7)  == 0x6c91fff0)
75       && (*(unsigned long *) (pc+11)  == 0x6ff0fff0))
76     sc = context->cfa;
77   else if ((*(unsigned long *) (pc-1)  == 0xcc004090)
78 	   && (*(unsigned long *) (pc+3)  == 0xc802b490)
79 	   && (*(unsigned long *) (pc+7)  == 0x6c91fff0)
80 	   && (*(unsigned long *) (pc+11)  == 0x6ff0fff0))
81     {
82       struct rt_sigframe {
83 	siginfo_t *pinfo;
84 	void *puc;
85 	siginfo_t info;
86 	struct ucontext uc;
87       } *rt_ = context->cfa;
88       /* The void * cast is necessary to avoid an aliasing warning.
89          The aliasing warning is correct, but should not be a problem
90          because it does not alias anything.  */
91       sc = (struct sigcontext *) (void *) &rt_->uc.uc_mcontext;
92     }
93   else
94     return _URC_END_OF_STACK;
95 
96   new_cfa = sc->sc_regs[15];
97   fs->regs.cfa_how = CFA_REG_OFFSET;
98   fs->regs.cfa_reg = 15;
99   fs->regs.cfa_offset = new_cfa - (long) context->cfa;
100 
101   for (i = 0; i < 63; i++)
102     {
103       if (i == 15)
104 	continue;
105 
106       fs->regs.reg[i].how = REG_SAVED_OFFSET;
107       fs->regs.reg[i].loc.offset
108 	= (long)&(sc->sc_regs[i]) - new_cfa;
109     }
110 
111   fs->regs.reg[SH_DWARF_FRAME_SR].how = REG_SAVED_OFFSET;
112   fs->regs.reg[SH_DWARF_FRAME_SR].loc.offset
113     = (long)&(sc->sc_sr) - new_cfa;
114 
115   r = SH_DWARF_FRAME_BT0;
116   for (i = 0; i < 8; i++)
117     {
118       fs->regs.reg[r+i].how = REG_SAVED_OFFSET;
119       fs->regs.reg[r+i].loc.offset
120 	= (long)&(sc->sc_tregs[i]) - new_cfa;
121     }
122 
123   r = SH_DWARF_FRAME_FP0;
124   for (i = 0; i < 32; i++)
125     {
126       fs->regs.reg[r+i].how = REG_SAVED_OFFSET;
127       fs->regs.reg[r+i].loc.offset
128 	= (long)&(sc->sc_fpregs[i]) - new_cfa;
129     }
130 
131   fs->regs.reg[SH_DWARF_FRAME_FPSCR].how = REG_SAVED_OFFSET;
132   fs->regs.reg[SH_DWARF_FRAME_FPSCR].loc.offset
133     = (long)&(sc->sc_fpscr) - new_cfa;
134 
135   /* We use the slot for the zero register to save return address.  */
136   fs->regs.reg[63].how = REG_SAVED_OFFSET;
137   fs->regs.reg[63].loc.offset
138     = (long)&(sc->sc_pc) - new_cfa;
139   fs->retaddr_column = 63;
140   fs->signal_frame = 1;
141   return _URC_NO_REASON;
142 }
143 
144 #else /* defined (__SH5__) */
145 
146 #define MD_FALLBACK_FRAME_STATE_FOR sh_fallback_frame_state
147 
148 static _Unwind_Reason_Code
149 sh_fallback_frame_state (struct _Unwind_Context *context,
150 			 _Unwind_FrameState *fs)
151 {
152   unsigned char *pc = context->ra;
153   struct sigcontext *sc;
154   long new_cfa;
155   int i;
156 #if defined (__SH3E__) || defined (__SH4__)
157   int r;
158 #endif
159 
160   /* mov.w 1f,r3; trapa #0x10; 1: .short 0x77  (sigreturn)  */
161   /* mov.w 1f,r3; trapa #0x10; 1: .short 0xad  (rt_sigreturn)  */
162   /* Newer kernel uses pad instructions to avoid an SH-4 core bug.  */
163   /* mov.w 1f,r3; trapa #0x10; or r0,r0; or r0,r0; or r0,r0; or r0,r0;
164      or r0,r0; 1: .short 0x77  (sigreturn)  */
165   /* mov.w 1f,r3; trapa #0x10; or r0,r0; or r0,r0; or r0,r0; or r0,r0;
166      or r0,r0; 1: .short 0xad  (rt_sigreturn)  */
167   if (((*(unsigned short *) (pc+0)  == 0x9300)
168        && (*(unsigned short *) (pc+2)  == 0xc310)
169        && (*(unsigned short *) (pc+4)  == 0x0077))
170       || (((*(unsigned short *) (pc+0)  == 0x9305)
171 	   && (*(unsigned short *) (pc+2)  == 0xc310)
172 	   && (*(unsigned short *) (pc+14)  == 0x0077))))
173     sc = context->cfa;
174   else if (((*(unsigned short *) (pc+0) == 0x9300)
175 	    && (*(unsigned short *) (pc+2)  == 0xc310)
176 	    && (*(unsigned short *) (pc+4)  == 0x00ad))
177 	   || (((*(unsigned short *) (pc+0) == 0x9305)
178 		&& (*(unsigned short *) (pc+2)  == 0xc310)
179 		&& (*(unsigned short *) (pc+14)  == 0x00ad))))
180     {
181       struct rt_sigframe {
182 	siginfo_t info;
183 	struct ucontext uc;
184       } *rt_ = context->cfa;
185       /* The void * cast is necessary to avoid an aliasing warning.
186          The aliasing warning is correct, but should not be a problem
187          because it does not alias anything.  */
188       sc = (struct sigcontext *) (void *) &rt_->uc.uc_mcontext;
189     }
190   else
191     return _URC_END_OF_STACK;
192 
193   new_cfa = sc->sc_regs[15];
194   fs->regs.cfa_how = CFA_REG_OFFSET;
195   fs->regs.cfa_reg = 15;
196   fs->regs.cfa_offset = new_cfa - (long) context->cfa;
197 
198   for (i = 0; i < 15; i++)
199     {
200       fs->regs.reg[i].how = REG_SAVED_OFFSET;
201       fs->regs.reg[i].loc.offset
202 	= (long)&(sc->sc_regs[i]) - new_cfa;
203     }
204 
205   fs->regs.reg[SH_DWARF_FRAME_PR].how = REG_SAVED_OFFSET;
206   fs->regs.reg[SH_DWARF_FRAME_PR].loc.offset
207     = (long)&(sc->sc_pr) - new_cfa;
208   fs->regs.reg[SH_DWARF_FRAME_SR].how = REG_SAVED_OFFSET;
209   fs->regs.reg[SH_DWARF_FRAME_SR].loc.offset
210     = (long)&(sc->sc_sr) - new_cfa;
211   fs->regs.reg[SH_DWARF_FRAME_GBR].how = REG_SAVED_OFFSET;
212   fs->regs.reg[SH_DWARF_FRAME_GBR].loc.offset
213     = (long)&(sc->sc_gbr) - new_cfa;
214   fs->regs.reg[SH_DWARF_FRAME_MACH].how = REG_SAVED_OFFSET;
215   fs->regs.reg[SH_DWARF_FRAME_MACH].loc.offset
216     = (long)&(sc->sc_mach) - new_cfa;
217   fs->regs.reg[SH_DWARF_FRAME_MACL].how = REG_SAVED_OFFSET;
218   fs->regs.reg[SH_DWARF_FRAME_MACL].loc.offset
219     = (long)&(sc->sc_macl) - new_cfa;
220 
221 #if defined (__SH3E__) || defined (__SH4__)
222   r = SH_DWARF_FRAME_FP0;
223   for (i = 0; i < 16; i++)
224     {
225       fs->regs.reg[r+i].how = REG_SAVED_OFFSET;
226       fs->regs.reg[r+i].loc.offset
227 	= (long)&(sc->sc_fpregs[i]) - new_cfa;
228     }
229 
230   r = SH_DWARF_FRAME_XD0;
231   for (i = 0; i < 8; i++)
232     {
233       fs->regs.reg[r+i].how = REG_SAVED_OFFSET;
234       fs->regs.reg[r+i].loc.offset
235 	= (long)&(sc->sc_xfpregs[2*i]) - new_cfa;
236     }
237 
238   fs->regs.reg[SH_DWARF_FRAME_FPUL].how = REG_SAVED_OFFSET;
239   fs->regs.reg[SH_DWARF_FRAME_FPUL].loc.offset
240     = (long)&(sc->sc_fpul) - new_cfa;
241   fs->regs.reg[SH_DWARF_FRAME_FPSCR].how = REG_SAVED_OFFSET;
242   fs->regs.reg[SH_DWARF_FRAME_FPSCR].loc.offset
243     = (long)&(sc->sc_fpscr) - new_cfa;
244 #endif
245 
246   fs->regs.reg[SH_DWARF_FRAME_PC].how = REG_SAVED_OFFSET;
247   fs->regs.reg[SH_DWARF_FRAME_PC].loc.offset
248     = (long)&(sc->sc_pc) - new_cfa;
249   fs->retaddr_column = SH_DWARF_FRAME_PC;
250   fs->signal_frame = 1;
251   return _URC_NO_REASON;
252 }
253 #endif /* defined (__SH5__) */
254 
255 #endif /* inhibit_libc */
256