/src/elfutils/backends/aarch64_unwind.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* Get previous frame state for an existing frame state. |
2 | | Copyright (C) 2016 The Qt Company Ltd. |
3 | | This file is part of elfutils. |
4 | | |
5 | | This file is free software; you can redistribute it and/or modify |
6 | | it under the terms of either |
7 | | |
8 | | * the GNU Lesser General Public License as published by the Free |
9 | | Software Foundation; either version 3 of the License, or (at |
10 | | your option) any later version |
11 | | |
12 | | or |
13 | | |
14 | | * the GNU General Public License as published by the Free |
15 | | Software Foundation; either version 2 of the License, or (at |
16 | | your option) any later version |
17 | | |
18 | | or both in parallel, as here. |
19 | | |
20 | | elfutils is distributed in the hope that it will be useful, but |
21 | | WITHOUT ANY WARRANTY; without even the implied warranty of |
22 | | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
23 | | General Public License for more details. |
24 | | |
25 | | You should have received copies of the GNU General Public License and |
26 | | the GNU Lesser General Public License along with this program. If |
27 | | not, see <http://www.gnu.org/licenses/>. */ |
28 | | |
29 | | #ifdef HAVE_CONFIG_H |
30 | | # include <config.h> |
31 | | #endif |
32 | | |
33 | | #define BACKEND aarch64_ |
34 | 0 | #define FP_REG 29 |
35 | 0 | #define LR_REG 30 |
36 | 0 | #define SP_REG 31 |
37 | 0 | #define FP_OFFSET 0 |
38 | 0 | #define LR_OFFSET 8 |
39 | 0 | #define SP_OFFSET 16 |
40 | | |
41 | | #include "libebl_CPU.h" |
42 | | |
43 | | /* There was no CFI. Maybe we happen to have a frame pointer and can unwind from that? */ |
44 | | |
45 | | bool |
46 | | EBLHOOK(unwind) (Ebl *ebl __attribute__ ((unused)), Dwarf_Addr pc __attribute__ ((unused)), |
47 | | ebl_tid_registers_t *setfunc, ebl_tid_registers_get_t *getfunc, |
48 | | ebl_pid_memory_read_t *readfunc, void *arg, |
49 | | bool *signal_framep __attribute__ ((unused))) |
50 | 0 | { |
51 | 0 | Dwarf_Word fp, lr, sp; |
52 | |
|
53 | 0 | if (!getfunc(LR_REG, 1, &lr, arg)) |
54 | 0 | return false; |
55 | | |
56 | 0 | if (lr == 0 || !setfunc(-1, 1, &lr, arg)) |
57 | 0 | return false; |
58 | | |
59 | 0 | if (!getfunc(FP_REG, 1, &fp, arg)) |
60 | 0 | fp = 0; |
61 | |
|
62 | 0 | if (!getfunc(SP_REG, 1, &sp, arg)) |
63 | 0 | sp = 0; |
64 | |
|
65 | 0 | Dwarf_Word newLr, newFp, newSp; |
66 | |
|
67 | 0 | if (!readfunc(fp + LR_OFFSET, &newLr, arg)) |
68 | 0 | newLr = 0; |
69 | |
|
70 | 0 | if (!readfunc(fp + FP_OFFSET, &newFp, arg)) |
71 | 0 | newFp = 0; |
72 | |
|
73 | 0 | newSp = fp + SP_OFFSET; |
74 | | |
75 | | // These are not fatal if they don't work. They will just prevent unwinding at the next frame. |
76 | 0 | setfunc(LR_REG, 1, &newLr, arg); |
77 | 0 | setfunc(FP_REG, 1, &newFp, arg); |
78 | 0 | setfunc(SP_REG, 1, &newSp, arg); |
79 | | |
80 | | // If the fp is invalid, we might still have a valid lr. |
81 | | // But if the fp is valid, then the stack should be moving in the right direction. |
82 | 0 | return fp == 0 || newSp > sp; |
83 | 0 | } |