1 /* libunwind - a platform-independent unwind library
2 Copyright (C) 2008 CodeSourcery
3
4 This file is part of libunwind.
5
6 Permission is hereby granted, free of charge, to any person obtaining
7 a copy of this software and associated documentation files (the
8 "Software"), to deal in the Software without restriction, including
9 without limitation the rights to use, copy, modify, merge, publish,
10 distribute, sublicense, and/or sell copies of the Software, and to
11 permit persons to whom the Software is furnished to do so, subject to
12 the following conditions:
13
14 The above copyright notice and this permission notice shall be
15 included in all copies or substantial portions of the Software.
16
17 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
18 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
20 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
21 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
22 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
23 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
24
25 #include "unwind_i.h"
26 #include "offsets.h"
27
28 PROTECTED int
unw_handle_signal_frame(unw_cursor_t * cursor)29 unw_handle_signal_frame (unw_cursor_t *cursor)
30 {
31 struct cursor *c = (struct cursor *) cursor;
32 unw_word_t sc_addr, sp, sp_addr = c->dwarf.cfa;
33 unw_word_t ra, fp;
34 int ret;
35
36 /* FIXME (simon): Save the SP and PC to be able to return execution
37 at this point later in time (unw_resume). */
38 // c->sigcontext_sp = c->dwarf.cfa;
39 // c->sigcontext_pc = c->dwarf.ip;
40
41 switch (unw_is_signal_frame (cursor)) {
42 case 1:
43 sc_addr = sp_addr + LINUX_SF_TRAMP_SIZE + sizeof (siginfo_t) +
44 LINUX_UC_MCONTEXT_OFF;
45 break;
46 case 2:
47 sc_addr = sp_addr + LINUX_UC_MCONTEXT_OFF;
48 break;
49 default:
50 return -UNW_EUNSPEC;
51 }
52
53 if (tdep_big_endian(c->dwarf.as))
54 sc_addr += 4;
55
56 c->sigcontext_addr = sc_addr;
57
58 /* Update the dwarf cursor. */
59 c->dwarf.loc[UNW_MIPS_R0] = DWARF_LOC (sc_addr + LINUX_SC_R0_OFF, 0);
60 c->dwarf.loc[UNW_MIPS_R1] = DWARF_LOC (sc_addr + LINUX_SC_R1_OFF, 0);
61 c->dwarf.loc[UNW_MIPS_R2] = DWARF_LOC (sc_addr + LINUX_SC_R2_OFF, 0);
62 c->dwarf.loc[UNW_MIPS_R3] = DWARF_LOC (sc_addr + LINUX_SC_R3_OFF, 0);
63 c->dwarf.loc[UNW_MIPS_R4] = DWARF_LOC (sc_addr + LINUX_SC_R4_OFF, 0);
64 c->dwarf.loc[UNW_MIPS_R5] = DWARF_LOC (sc_addr + LINUX_SC_R5_OFF, 0);
65 c->dwarf.loc[UNW_MIPS_R6] = DWARF_LOC (sc_addr + LINUX_SC_R6_OFF, 0);
66 c->dwarf.loc[UNW_MIPS_R7] = DWARF_LOC (sc_addr + LINUX_SC_R7_OFF, 0);
67 c->dwarf.loc[UNW_MIPS_R8] = DWARF_LOC (sc_addr + LINUX_SC_R8_OFF, 0);
68 c->dwarf.loc[UNW_MIPS_R9] = DWARF_LOC (sc_addr + LINUX_SC_R9_OFF, 0);
69 c->dwarf.loc[UNW_MIPS_R10] = DWARF_LOC (sc_addr + LINUX_SC_R10_OFF, 0);
70 c->dwarf.loc[UNW_MIPS_R11] = DWARF_LOC (sc_addr + LINUX_SC_R11_OFF, 0);
71 c->dwarf.loc[UNW_MIPS_R12] = DWARF_LOC (sc_addr + LINUX_SC_R12_OFF, 0);
72 c->dwarf.loc[UNW_MIPS_R13] = DWARF_LOC (sc_addr + LINUX_SC_R13_OFF, 0);
73 c->dwarf.loc[UNW_MIPS_R14] = DWARF_LOC (sc_addr + LINUX_SC_R14_OFF, 0);
74 c->dwarf.loc[UNW_MIPS_R15] = DWARF_LOC (sc_addr + LINUX_SC_R15_OFF, 0);
75 c->dwarf.loc[UNW_MIPS_R16] = DWARF_LOC (sc_addr + LINUX_SC_R16_OFF, 0);
76 c->dwarf.loc[UNW_MIPS_R17] = DWARF_LOC (sc_addr + LINUX_SC_R17_OFF, 0);
77 c->dwarf.loc[UNW_MIPS_R18] = DWARF_LOC (sc_addr + LINUX_SC_R18_OFF, 0);
78 c->dwarf.loc[UNW_MIPS_R19] = DWARF_LOC (sc_addr + LINUX_SC_R19_OFF, 0);
79 c->dwarf.loc[UNW_MIPS_R20] = DWARF_LOC (sc_addr + LINUX_SC_R20_OFF, 0);
80 c->dwarf.loc[UNW_MIPS_R21] = DWARF_LOC (sc_addr + LINUX_SC_R21_OFF, 0);
81 c->dwarf.loc[UNW_MIPS_R22] = DWARF_LOC (sc_addr + LINUX_SC_R22_OFF, 0);
82 c->dwarf.loc[UNW_MIPS_R23] = DWARF_LOC (sc_addr + LINUX_SC_R23_OFF, 0);
83 c->dwarf.loc[UNW_MIPS_R24] = DWARF_LOC (sc_addr + LINUX_SC_R24_OFF, 0);
84 c->dwarf.loc[UNW_MIPS_R25] = DWARF_LOC (sc_addr + LINUX_SC_R25_OFF, 0);
85 c->dwarf.loc[UNW_MIPS_R26] = DWARF_LOC (sc_addr + LINUX_SC_R26_OFF, 0);
86 c->dwarf.loc[UNW_MIPS_R27] = DWARF_LOC (sc_addr + LINUX_SC_R27_OFF, 0);
87 c->dwarf.loc[UNW_MIPS_R28] = DWARF_LOC (sc_addr + LINUX_SC_R28_OFF, 0);
88 c->dwarf.loc[UNW_MIPS_R29] = DWARF_LOC (sc_addr + LINUX_SC_R29_OFF, 0);
89 c->dwarf.loc[UNW_MIPS_R30] = DWARF_LOC (sc_addr + LINUX_SC_R30_OFF, 0);
90 c->dwarf.loc[UNW_MIPS_R31] = DWARF_LOC (sc_addr + LINUX_SC_R31_OFF, 0);
91 c->dwarf.loc[UNW_MIPS_PC] = DWARF_LOC (sc_addr + LINUX_SC_PC_OFF, 0);
92
93 /* Set SP/CFA and PC/IP. */
94 dwarf_get (&c->dwarf, c->dwarf.loc[UNW_MIPS_R29], &c->dwarf.cfa);
95 //dwarf_get (&c->dwarf, c->dwarf.loc[UNW_MIPS_R31], &c->dwarf.ip);
96
97 if ((ret = dwarf_get(&c->dwarf, DWARF_LOC(sc_addr + LINUX_SC_PC_OFF, 0),
98 &c->dwarf.ip)) < 0)
99 return ret;
100
101 if ((ret = dwarf_get(&c->dwarf, DWARF_LOC(sc_addr + LINUX_SC_R31_OFF, 0),
102 &ra)) < 0)
103 return ret;
104 if ((ret = dwarf_get(&c->dwarf, DWARF_LOC(sc_addr + LINUX_SC_R30_OFF, 0),
105 &fp)) < 0)
106 return ret;
107
108 Debug (2, "SH (ip=0x%016llx, ra=0x%016llx, sp=0x%016llx, fp=0x%016llx)\n",
109 (unsigned long long)c->dwarf.ip, (unsigned long long)ra,
110 (unsigned long long)c->dwarf.cfa, (unsigned long long)fp);
111
112 c->dwarf.pi_valid = 0;
113 c->dwarf.use_prev_instr = 0;
114
115 return 1;
116 }
117
118 PROTECTED int
unw_step(unw_cursor_t * cursor)119 unw_step (unw_cursor_t *cursor)
120 {
121 struct cursor *c = (struct cursor *) cursor;
122 int ret;
123
124 unw_word_t old_ip = c->dwarf.ip;
125 unw_word_t old_cfa = c->dwarf.cfa;
126
127 ret = unw_handle_signal_frame (cursor);
128 if (ret < 0)
129 /* Not a signal frame, try DWARF-based unwinding. */
130 ret = dwarf_step (&c->dwarf);
131
132 if (unlikely (ret == -UNW_ESTOPUNWIND))
133 return ret;
134
135 /* Dwarf unwinding didn't work, stop. */
136 if (unlikely (ret < 0))
137 return 0;
138
139 /* If the decode yields the exact same ip/cfa as before, then indicate
140 the unwind is complete. */
141 if (c->dwarf.ip == old_ip && c->dwarf.cfa == old_cfa)
142 {
143 Dprintf ("%s: ip and cfa unchanged; stopping here (ip=0x%lx)\n",
144 __FUNCTION__, (long) c->dwarf.ip);
145 return -UNW_EBADFRAME;
146 }
147
148 return (c->dwarf.ip == 0) ? 0 : 1;
149 }
150