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99dee823 | 1 | /* Copyright (C) 2009-2021 Free Software Foundation, Inc. |
d507e9a3 MS |
2 | Contributed by ARM Ltd. |
3 | ||
4 | This file is free software; you can redistribute it and/or modify it | |
5 | under the terms of the GNU General Public License as published by the | |
6 | Free Software Foundation; either version 3, or (at your option) any | |
7 | later version. | |
8 | ||
9 | This file is distributed in the hope that it will be useful, but | |
10 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | General Public License for more details. | |
13 | ||
14 | Under Section 7 of GPL version 3, you are granted additional | |
15 | permissions described in the GCC Runtime Library Exception, version | |
16 | 3.1, as published by the Free Software Foundation. | |
17 | ||
18 | You should have received a copy of the GNU General Public License and | |
19 | a copy of the GCC Runtime Library Exception along with this program; | |
20 | see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
21 | <http://www.gnu.org/licenses/>. */ | |
22 | ||
aa348be2 JW |
23 | /* Always include AArch64 unwinder header file. */ |
24 | #include "config/aarch64/aarch64-unwind.h" | |
25 | ||
d507e9a3 MS |
26 | #ifndef inhibit_libc |
27 | ||
28 | #include <signal.h> | |
29 | #include <sys/ucontext.h> | |
30 | ||
cceeb9a9 ML |
31 | |
32 | /* Since insns are always stored LE, on a BE system the opcodes will | |
33 | be loaded byte-reversed. Therefore, define two sets of opcodes, | |
34 | one for LE and one for BE. */ | |
35 | ||
36 | #if __AARCH64EB__ | |
37 | #define MOVZ_X8_8B 0x681180d2 | |
38 | #define SVC_0 0x010000d4 | |
39 | #else | |
40 | #define MOVZ_X8_8B 0xd2801168 | |
41 | #define SVC_0 0xd4000001 | |
42 | #endif | |
43 | ||
d507e9a3 MS |
44 | #define MD_FALLBACK_FRAME_STATE_FOR aarch64_fallback_frame_state |
45 | ||
46 | static _Unwind_Reason_Code | |
47 | aarch64_fallback_frame_state (struct _Unwind_Context *context, | |
48 | _Unwind_FrameState * fs) | |
49 | { | |
50 | /* The kernel creates an rt_sigframe on the stack immediately prior | |
51 | to delivering a signal. | |
52 | ||
53 | This structure must have the same shape as the linux kernel | |
54 | equivalent. */ | |
55 | struct rt_sigframe | |
56 | { | |
57 | siginfo_t info; | |
883312dc | 58 | ucontext_t uc; |
d507e9a3 MS |
59 | }; |
60 | ||
61 | struct rt_sigframe *rt_; | |
62 | _Unwind_Ptr new_cfa; | |
63 | unsigned *pc = context->ra; | |
64 | struct sigcontext *sc; | |
65 | struct _aarch64_ctx *extension_marker; | |
66 | int i; | |
67 | ||
68 | /* A signal frame will have a return address pointing to | |
69 | __default_sa_restorer. This code is hardwired as: | |
70 | ||
71 | 0xd2801168 movz x8, #0x8b | |
72 | 0xd4000001 svc 0x0 | |
73 | */ | |
cceeb9a9 | 74 | if (pc[0] != MOVZ_X8_8B || pc[1] != SVC_0) |
d507e9a3 MS |
75 | { |
76 | return _URC_END_OF_STACK; | |
77 | } | |
78 | ||
79 | rt_ = context->cfa; | |
80 | sc = &rt_->uc.uc_mcontext; | |
81 | ||
82 | /* This define duplicates the definition in aarch64.md */ | |
83 | #define SP_REGNUM 31 | |
84 | ||
85 | new_cfa = (_Unwind_Ptr) sc; | |
86 | fs->regs.cfa_how = CFA_REG_OFFSET; | |
53d68b9f | 87 | fs->regs.cfa_reg = __LIBGCC_STACK_POINTER_REGNUM__; |
d507e9a3 MS |
88 | fs->regs.cfa_offset = new_cfa - (_Unwind_Ptr) context->cfa; |
89 | ||
90 | for (i = 0; i < AARCH64_DWARF_NUMBER_R; i++) | |
91 | { | |
92 | fs->regs.reg[AARCH64_DWARF_R0 + i].how = REG_SAVED_OFFSET; | |
93 | fs->regs.reg[AARCH64_DWARF_R0 + i].loc.offset = | |
94 | (_Unwind_Ptr) & (sc->regs[i]) - new_cfa; | |
95 | } | |
96 | ||
97 | /* The core context may be extended with an arbitrary set of | |
98 | additional contexts appended sequentially. Each additional | |
99 | context contains a magic identifier and size in bytes. The size | |
100 | field can be used to skip over unrecognized context extensions. | |
101 | The end of the context sequence is marked by a context with magic | |
102 | 0 or size 0. */ | |
103 | for (extension_marker = (struct _aarch64_ctx *) &sc->__reserved; | |
104 | extension_marker->magic; | |
105 | extension_marker = (struct _aarch64_ctx *) | |
106 | ((unsigned char *) extension_marker + extension_marker->size)) | |
107 | { | |
108 | if (extension_marker->magic == FPSIMD_MAGIC) | |
109 | { | |
110 | struct fpsimd_context *ctx = | |
111 | (struct fpsimd_context *) extension_marker; | |
112 | int i; | |
113 | ||
114 | for (i = 0; i < AARCH64_DWARF_NUMBER_V; i++) | |
115 | { | |
116 | _Unwind_Sword offset; | |
117 | ||
118 | fs->regs.reg[AARCH64_DWARF_V0 + i].how = REG_SAVED_OFFSET; | |
119 | ||
120 | /* sigcontext contains 32 128bit registers for V0 to | |
121 | V31. The kernel will have saved the contents of the | |
122 | V registers. We want to unwind the callee save D | |
123 | registers. Each D register comprises the least | |
124 | significant half of the corresponding V register. We | |
125 | need to offset into the saved V register dependent on | |
126 | our endianness to find the saved D register. */ | |
127 | ||
128 | offset = (_Unwind_Ptr) & (ctx->vregs[i]) - new_cfa; | |
129 | ||
130 | /* The endianness adjustment code below expects that a | |
131 | saved V register is 16 bytes. */ | |
132 | gcc_assert (sizeof (ctx->vregs[0]) == 16); | |
133 | #if defined (__AARCH64EB__) | |
134 | offset = offset + 8; | |
135 | #endif | |
136 | fs->regs.reg[AARCH64_DWARF_V0 + i].loc.offset = offset; | |
137 | } | |
138 | } | |
139 | else | |
140 | { | |
141 | /* There is context provided that we do not recognize! */ | |
142 | } | |
143 | } | |
144 | ||
145 | fs->regs.reg[31].how = REG_SAVED_OFFSET; | |
146 | fs->regs.reg[31].loc.offset = (_Unwind_Ptr) & (sc->sp) - new_cfa; | |
147 | ||
148 | fs->signal_frame = 1; | |
149 | ||
53d68b9f JM |
150 | fs->regs.reg[__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__].how = |
151 | REG_SAVED_VAL_OFFSET; | |
152 | fs->regs.reg[__LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__].loc.offset = | |
d507e9a3 MS |
153 | (_Unwind_Ptr) (sc->pc) - new_cfa; |
154 | ||
53d68b9f | 155 | fs->retaddr_column = __LIBGCC_DWARF_ALT_FRAME_RETURN_COLUMN__; |
d507e9a3 MS |
156 | |
157 | return _URC_NO_REASON; | |
158 | } | |
159 | ||
160 | #endif |