1 /* Return backtrace of current program state.
2 Copyright (C) 2003-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
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.
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.
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/>. */
22 #include <unwind-link.h>
27 struct unwind_link *unwind_link;
33 static _Unwind_Reason_Code
34 backtrace_helper (struct _Unwind_Context *ctx, void *a)
36 struct trace_arg *arg = a;
38 /* We are first called with address in the __backtrace function.
43 = (void *) UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetIP) (ctx);
46 = unwind_arch_adjustment (arg->array[arg->cnt - 1],
47 arg->array[arg->cnt]);
49 /* Check whether we make any progress. */
51 = UNWIND_LINK_PTR (arg->unwind_link, _Unwind_GetCFA) (ctx);
53 if (arg->cnt > 0 && arg->array[arg->cnt - 1] == arg->array[arg->cnt]
55 return _URC_END_OF_STACK;
58 if (++arg->cnt == arg->size)
59 return _URC_END_OF_STACK;
60 return _URC_NO_REASON;
64 __backtrace (void **array, int size)
66 struct trace_arg arg =
69 .unwind_link = __libc_unwind_link_get (),
75 if (size <= 0 || arg.unwind_link == NULL)
78 UNWIND_LINK_PTR (arg.unwind_link, _Unwind_Backtrace)
79 (backtrace_helper, &arg);
81 /* _Unwind_Backtrace seems to put NULL address above
82 _start. Fix it up here. */
83 if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL)
85 return arg.cnt != -1 ? arg.cnt : 0;
87 weak_alias (__backtrace, backtrace)
88 libc_hidden_def (__backtrace)