1 /* libunwind - a platform-independent unwind library
2    Copyright (C) 2008 CodeSourcery
3    Copyright (C) 2011-2013 Linaro Limited
4    Copyright (C) 2012 Tommi Rantala <tt.rantala@gmail.com>
5 
6 This file is part of libunwind.
7 
8 Permission is hereby granted, free of charge, to any person obtaining
9 a copy of this software and associated documentation files (the
10 "Software"), to deal in the Software without restriction, including
11 without limitation the rights to use, copy, modify, merge, publish,
12 distribute, sublicense, and/or sell copies of the Software, and to
13 permit persons to whom the Software is furnished to do so, subject to
14 the following conditions:
15 
16 The above copyright notice and this permission notice shall be
17 included in all copies or substantial portions of the Software.
18 
19 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
23 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
24 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
25 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
26 
27 #include "unwind_i.h"
28 #include "offsets.h"
29 
30 #ifndef UNW_REMOTE_ONLY
31 
32 HIDDEN inline int
aarch64_local_resume(unw_addr_space_t as,unw_cursor_t * cursor,void * arg)33 aarch64_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
34 {
35 #ifdef __linux__
36   struct cursor *c = (struct cursor *) cursor;
37   unw_tdep_context_t *uc = c->dwarf.as_arg;
38 
39   if (c->sigcontext_format == AARCH64_SCF_NONE)
40     {
41       /* Since there are no signals involved here we restore the non scratch
42 	 registers only.  */
43       unsigned long regs[11];
44       regs[0] = uc->uc_mcontext.regs[19];
45       regs[1] = uc->uc_mcontext.regs[20];
46       regs[2] = uc->uc_mcontext.regs[21];
47       regs[3] = uc->uc_mcontext.regs[22];
48       regs[4] = uc->uc_mcontext.regs[23];
49       regs[5] = uc->uc_mcontext.regs[24];
50       regs[6] = uc->uc_mcontext.regs[25];
51       regs[7] = uc->uc_mcontext.regs[26];
52       regs[8] = uc->uc_mcontext.regs[27];
53       regs[9] = uc->uc_mcontext.regs[28];
54       regs[10] = uc->uc_mcontext.regs[30]; /* LR */
55       unsigned long sp = uc->uc_mcontext.sp;
56 
57       struct regs_overlay {
58         char x[sizeof(regs)];
59       };
60 
61       asm volatile (
62         "ldp x19, x20, [%0]\n"
63         "ldp x21, x22, [%0,16]\n"
64         "ldp x23, x24, [%0,32]\n"
65         "ldp x25, x26, [%0,48]\n"
66         "ldp x27, x28, [%0,64]\n"
67         "ldr x30, [%0,80]\n"
68         "mov sp, %1\n"
69         "ret \n"
70         :
71         : "r" (regs),
72           "r" (sp),
73           "m" (*(struct regs_overlay *)regs)
74       );
75     }
76   else
77     {
78       struct sigcontext *sc = (struct sigcontext *) c->sigcontext_addr;
79 
80       if (c->dwarf.eh_valid_mask & 0x1) sc->regs[0] = c->dwarf.eh_args[0];
81       if (c->dwarf.eh_valid_mask & 0x2) sc->regs[1] = c->dwarf.eh_args[1];
82       if (c->dwarf.eh_valid_mask & 0x4) sc->regs[2] = c->dwarf.eh_args[2];
83       if (c->dwarf.eh_valid_mask & 0x8) sc->regs[3] = c->dwarf.eh_args[3];
84 
85       sc->regs[4] = uc->uc_mcontext.regs[4];
86       sc->regs[5] = uc->uc_mcontext.regs[5];
87       sc->regs[6] = uc->uc_mcontext.regs[6];
88       sc->regs[7] = uc->uc_mcontext.regs[7];
89       sc->regs[8] = uc->uc_mcontext.regs[8];
90       sc->regs[9] = uc->uc_mcontext.regs[9];
91       sc->regs[10] = uc->uc_mcontext.regs[10];
92       sc->regs[11] = uc->uc_mcontext.regs[11];
93       sc->regs[12] = uc->uc_mcontext.regs[12];
94       sc->regs[13] = uc->uc_mcontext.regs[13];
95       sc->regs[14] = uc->uc_mcontext.regs[14];
96       sc->regs[15] = uc->uc_mcontext.regs[15];
97       sc->regs[16] = uc->uc_mcontext.regs[16];
98       sc->regs[17] = uc->uc_mcontext.regs[17];
99       sc->regs[18] = uc->uc_mcontext.regs[18];
100       sc->regs[19] = uc->uc_mcontext.regs[19];
101       sc->regs[20] = uc->uc_mcontext.regs[20];
102       sc->regs[21] = uc->uc_mcontext.regs[21];
103       sc->regs[22] = uc->uc_mcontext.regs[22];
104       sc->regs[23] = uc->uc_mcontext.regs[23];
105       sc->regs[24] = uc->uc_mcontext.regs[24];
106       sc->regs[25] = uc->uc_mcontext.regs[25];
107       sc->regs[26] = uc->uc_mcontext.regs[26];
108       sc->regs[27] = uc->uc_mcontext.regs[27];
109       sc->regs[28] = uc->uc_mcontext.regs[28];
110       sc->regs[29] = uc->uc_mcontext.regs[29];
111       sc->regs[30] = uc->uc_mcontext.regs[30];
112       sc->sp = uc->uc_mcontext.sp;
113       sc->pc = uc->uc_mcontext.pc;
114       sc->pstate = uc->uc_mcontext.pstate;
115 
116       asm volatile (
117         "mov sp, %0\n"
118         "ret %1\n"
119         : : "r" (c->sigcontext_sp), "r" (c->sigcontext_pc)
120       );
121    }
122   unreachable();
123 #else
124   printf ("%s: implement me\n", __FUNCTION__);
125 #endif
126   return -UNW_EINVAL;
127 }
128 
129 #endif /* !UNW_REMOTE_ONLY */
130 
131 static inline void
establish_machine_state(struct cursor * c)132 establish_machine_state (struct cursor *c)
133 {
134   unw_addr_space_t as = c->dwarf.as;
135   void *arg = c->dwarf.as_arg;
136   unw_fpreg_t fpval;
137   unw_word_t val;
138   int reg;
139 
140   Debug (8, "copying out cursor state\n");
141 
142   for (reg = 0; reg <= UNW_AARCH64_PSTATE; ++reg)
143     {
144       Debug (16, "copying %s %d\n", unw_regname (reg), reg);
145       if (unw_is_fpreg (reg))
146 	{
147 	  if (tdep_access_fpreg (c, reg, &fpval, 0) >= 0)
148 	    as->acc.access_fpreg (as, reg, &fpval, 1, arg);
149 	}
150       else
151 	{
152 	  if (tdep_access_reg (c, reg, &val, 0) >= 0)
153 	    as->acc.access_reg (as, reg, &val, 1, arg);
154 	}
155     }
156 }
157 
158 PROTECTED int
unw_resume(unw_cursor_t * cursor)159 unw_resume (unw_cursor_t *cursor)
160 {
161   struct cursor *c = (struct cursor *) cursor;
162 
163   Debug (1, "(cursor=%p)\n", c);
164 
165   if (!c->dwarf.ip)
166     {
167       /* This can happen easily when the frame-chain gets truncated
168 	 due to bad or missing unwind-info.  */
169       Debug (1, "refusing to resume execution at address 0\n");
170       return -UNW_EINVAL;
171     }
172 
173   establish_machine_state (c);
174 
175   return (*c->dwarf.as->acc.resume) (c->dwarf.as, (unw_cursor_t *) c,
176 				     c->dwarf.as_arg);
177 }
178