1 | /* Return backtrace of current program state. |
2 | Copyright (C) 2008-2022 Free Software Foundation, Inc. |
3 | This file is part of the GNU C Library. |
4 | |
5 | The GNU C Library is free software; you can redistribute it and/or |
6 | modify it under the terms of the GNU Lesser General Public |
7 | License as published by the Free Software Foundation; either |
8 | version 2.1 of the License, or (at your option) any later version. |
9 | |
10 | The GNU C Library is distributed in the hope that it will be useful, |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
13 | Lesser General Public License for more details. |
14 | |
15 | You should have received a copy of the GNU Lesser General Public |
16 | License along with the GNU C Library. If not, see |
17 | <https://www.gnu.org/licenses/>. */ |
18 | |
19 | #include <execinfo.h> |
20 | #include <stdlib.h> |
21 | #include <unwind-link.h> |
22 | |
23 | struct trace_arg |
24 | { |
25 | void **array; |
26 | struct unwind_link *unwind_link; |
27 | int cnt, size; |
28 | }; |
29 | |
30 | #ifdef SHARED |
31 | /* This function is identical to "_Unwind_GetGR", except that it uses |
32 | "unwind_vrs_get" instead of "_Unwind_VRS_Get". */ |
33 | static inline _Unwind_Word |
34 | unwind_getgr (struct unwind_link *unwind_link, |
35 | _Unwind_Context *context, int regno) |
36 | { |
37 | _uw val; |
38 | UNWIND_LINK_PTR (unwind_link, _Unwind_VRS_Get) |
39 | (context, _UVRSC_CORE, regno, _UVRSD_UINT32, &val); |
40 | return val; |
41 | } |
42 | |
43 | /* This macro is identical to the _Unwind_GetIP macro, except that it |
44 | uses "unwind_getgr" instead of "_Unwind_GetGR". */ |
45 | #define unwind_getip(context) \ |
46 | (unwind_getgr (arg->unwind_link, context, 15) & ~(_Unwind_Word)1) |
47 | |
48 | #else /* !SHARED */ |
49 | # define unwind_getip _Unwind_GetIP |
50 | #endif |
51 | |
52 | static _Unwind_Reason_Code |
53 | backtrace_helper (struct _Unwind_Context *ctx, void *a) |
54 | { |
55 | struct trace_arg *arg = a; |
56 | |
57 | /* We are first called with address in the __backtrace function. |
58 | Skip it. */ |
59 | if (arg->cnt != -1) |
60 | arg->array[arg->cnt] = (void *) unwind_getip (ctx); |
61 | if (++arg->cnt == arg->size) |
62 | return _URC_END_OF_STACK; |
63 | return _URC_NO_REASON; |
64 | } |
65 | |
66 | int |
67 | __backtrace (void **array, int size) |
68 | { |
69 | struct trace_arg arg = |
70 | { |
71 | .array = array, |
72 | .unwind_link = __libc_unwind_link_get (), |
73 | .size = size, |
74 | .cnt = -1 |
75 | }; |
76 | |
77 | if (size <= 0 || arg.unwind_link == NULL) |
78 | return 0; |
79 | |
80 | UNWIND_LINK_PTR (arg.unwind_link, _Unwind_Backtrace) |
81 | (backtrace_helper, &arg); |
82 | |
83 | if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL) |
84 | --arg.cnt; |
85 | return arg.cnt != -1 ? arg.cnt : 0; |
86 | } |
87 | weak_alias (__backtrace, backtrace) |
88 | libc_hidden_def (__backtrace) |
89 | |