| xf.li | bdd93d5 | 2023-05-12 07:10:14 -0700 | [diff] [blame] | 1 | /* Return backtrace of current program state. Generic version. |
| 2 | Copyright (C) 1998-2016 Free Software Foundation, Inc. |
| 3 | This file is part of the GNU C Library. |
| 4 | Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. |
| 5 | |
| 6 | The GNU C Library is free software; you can redistribute it and/or |
| 7 | modify it under the terms of the GNU Lesser General Public |
| 8 | License as published by the Free Software Foundation; either |
| 9 | version 2.1 of the License, or (at your option) any later version. |
| 10 | |
| 11 | The GNU C Library is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | Lesser General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU Lesser General Public |
| 17 | License along with the GNU C Library; if not, see |
| 18 | <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include <execinfo.h> |
| 21 | #include <signal.h> |
| 22 | #include <frame.h> |
| 23 | #include <sigcontextinfo.h> |
| 24 | #include <ldsodefs.h> |
| 25 | |
| 26 | /* This implementation assumes a stack layout that matches the defaults |
| 27 | used by gcc's `__builtin_frame_address' and `__builtin_return_address' |
| 28 | (FP is the frame pointer register): |
| 29 | |
| 30 | +-----------------+ +-----------------+ |
| 31 | FP -> | previous FP --------> | previous FP ------>... |
| 32 | | | | | |
| 33 | | return address | | return address | |
| 34 | +-----------------+ +-----------------+ |
| 35 | |
| 36 | */ |
| 37 | |
| 38 | /* Get some notion of the current stack. Need not be exactly the top |
| 39 | of the stack, just something somewhere in the current frame. */ |
| 40 | #ifndef CURRENT_STACK_FRAME |
| 41 | # define CURRENT_STACK_FRAME ({ char __csf; &__csf; }) |
| 42 | #endif |
| 43 | |
| 44 | /* By default we assume that the stack grows downward. */ |
| 45 | #ifndef INNER_THAN |
| 46 | # define INNER_THAN < |
| 47 | #endif |
| 48 | |
| 49 | /* By default assume the `next' pointer in struct layout points to the |
| 50 | next struct layout. */ |
| 51 | #ifndef ADVANCE_STACK_FRAME |
| 52 | # define ADVANCE_STACK_FRAME(next) ((struct layout *) (next)) |
| 53 | #endif |
| 54 | |
| 55 | /* By default, the frame pointer is just what we get from gcc. */ |
| 56 | #ifndef FIRST_FRAME_POINTER |
| 57 | # define FIRST_FRAME_POINTER __builtin_frame_address (0) |
| 58 | #endif |
| 59 | |
| 60 | int |
| 61 | __backtrace (void **array, int size) |
| 62 | { |
| 63 | struct layout *current; |
| 64 | void *top_frame; |
| 65 | void *top_stack; |
| 66 | int cnt = 0; |
| 67 | |
| 68 | top_frame = FIRST_FRAME_POINTER; |
| 69 | top_stack = CURRENT_STACK_FRAME; |
| 70 | |
| 71 | /* We skip the call to this function, it makes no sense to record it. */ |
| 72 | current = ((struct layout *) top_frame); |
| 73 | while (cnt < size) |
| 74 | { |
| 75 | if ((void *) current INNER_THAN top_stack |
| 76 | || !((void *) current INNER_THAN __libc_stack_end)) |
| 77 | /* This means the address is out of range. Note that for the |
| 78 | toplevel we see a frame pointer with value NULL which clearly is |
| 79 | out of range. */ |
| 80 | break; |
| 81 | |
| 82 | array[cnt++] = current->return_address; |
| 83 | |
| 84 | current = ADVANCE_STACK_FRAME (current->next); |
| 85 | } |
| 86 | |
| 87 | return cnt; |
| 88 | } |
| 89 | weak_alias (__backtrace, backtrace) |
| 90 | libc_hidden_def (__backtrace) |