1 /* libunwind - a platform-independent unwind library
2 Copyright (C) 2008 CodeSourcery
3 Copyright 2011 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 #if defined(__ANDROID__)
28 #include <asm/sigcontext.h>
29 #endif
30
31 #include "unwind_i.h"
32 #include "offsets.h"
33
34 #ifndef UNW_REMOTE_ONLY
35
36 HIDDEN inline int
arm_local_resume(unw_addr_space_t as,unw_cursor_t * cursor,void * arg)37 arm_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
38 {
39 #ifdef __linux__
40 struct cursor *c = (struct cursor *) cursor;
41 unw_tdep_context_t *uc = c->dwarf.as_arg;
42
43 if (c->sigcontext_format == ARM_SCF_NONE)
44 {
45 /* Since there are no signals involved here we restore the non scratch
46 registers only. */
47 unsigned long regs[10];
48 regs[0] = uc->regs[4];
49 regs[1] = uc->regs[5];
50 regs[2] = uc->regs[6];
51 regs[3] = uc->regs[7];
52 regs[4] = uc->regs[8];
53 regs[5] = uc->regs[9];
54 regs[6] = uc->regs[10];
55 regs[7] = uc->regs[11]; /* FP */
56 regs[8] = uc->regs[13]; /* SP */
57 regs[9] = uc->regs[14]; /* LR */
58
59 struct regs_overlay {
60 char x[sizeof(regs)];
61 };
62
63 asm __volatile__ (
64 "ldmia %0, {r4-r12, lr}\n"
65 "mov sp, r12\n"
66 "bx lr\n"
67 : : "r" (regs),
68 "m" (*(struct regs_overlay *)regs)
69 );
70 }
71 else
72 {
73 /* In case a signal frame is involved, we're using its trampoline which
74 calls sigreturn. */
75 struct sigcontext *sc = (struct sigcontext *) c->sigcontext_addr;
76 sc->arm_r0 = uc->regs[0];
77 sc->arm_r1 = uc->regs[1];
78 sc->arm_r2 = uc->regs[2];
79 sc->arm_r3 = uc->regs[3];
80 sc->arm_r4 = uc->regs[4];
81 sc->arm_r5 = uc->regs[5];
82 sc->arm_r6 = uc->regs[6];
83 sc->arm_r7 = uc->regs[7];
84 sc->arm_r8 = uc->regs[8];
85 sc->arm_r9 = uc->regs[9];
86 sc->arm_r10 = uc->regs[10];
87 sc->arm_fp = uc->regs[11]; /* FP */
88 sc->arm_ip = uc->regs[12]; /* IP */
89 sc->arm_sp = uc->regs[13]; /* SP */
90 sc->arm_lr = uc->regs[14]; /* LR */
91 sc->arm_pc = uc->regs[15]; /* PC */
92 /* clear the ITSTATE bits. */
93 sc->arm_cpsr &= 0xf9ff03ffUL;
94
95 /* Set the SP and the PC in order to continue execution at the modified
96 trampoline which restores the signal mask and the registers. */
97 asm __volatile__ (
98 "mov sp, %0\n"
99 "bx %1\n"
100 : : "r" (c->sigcontext_sp), "r" (c->sigcontext_pc)
101 );
102 }
103 unreachable();
104 #else
105 printf ("%s: implement me\n", __FUNCTION__);
106 #endif
107 return -UNW_EINVAL;
108 }
109
110 #endif /* !UNW_REMOTE_ONLY */
111
112 static inline void
establish_machine_state(struct cursor * c)113 establish_machine_state (struct cursor *c)
114 {
115 unw_addr_space_t as = c->dwarf.as;
116 void *arg = c->dwarf.as_arg;
117 unw_fpreg_t fpval;
118 unw_word_t val;
119 int reg;
120
121 Debug (8, "copying out cursor state\n");
122
123 for (reg = 0; reg <= UNW_REG_LAST; ++reg)
124 {
125 Debug (16, "copying %s %d\n", unw_regname (reg), reg);
126 if (unw_is_fpreg (reg))
127 {
128 if (tdep_access_fpreg (c, reg, &fpval, 0) >= 0)
129 as->acc.access_fpreg (as, reg, &fpval, 1, arg);
130 }
131 else
132 {
133 if (tdep_access_reg (c, reg, &val, 0) >= 0)
134 as->acc.access_reg (as, reg, &val, 1, arg);
135 }
136 }
137 }
138
139 PROTECTED int
unw_resume(unw_cursor_t * cursor)140 unw_resume (unw_cursor_t *cursor)
141 {
142 struct cursor *c = (struct cursor *) cursor;
143
144 Debug (1, "(cursor=%p)\n", c);
145
146 if (!c->dwarf.ip)
147 {
148 /* This can happen easily when the frame-chain gets truncated
149 due to bad or missing unwind-info. */
150 Debug (1, "refusing to resume execution at address 0\n");
151 return -UNW_EINVAL;
152 }
153
154 establish_machine_state (c);
155
156 return (*c->dwarf.as->acc.resume) (c->dwarf.as, (unw_cursor_t *) c,
157 c->dwarf.as_arg);
158 }
159