1 /* backtrace.c -- Entry point for stack backtrace library. 2 Copyright (C) 2012-2018 Free Software Foundation, Inc. 3 Written by Ian Lance Taylor, Google. 4 5 Redistribution and use in source and binary forms, with or without 6 modification, are permitted provided that the following conditions are 7 met: 8 9 (1) Redistributions of source code must retain the above copyright 10 notice, this list of conditions and the following disclaimer. 11 12 (2) Redistributions in binary form must reproduce the above copyright 13 notice, this list of conditions and the following disclaimer in 14 the documentation and/or other materials provided with the 15 distribution. 16 17 (3) The name of the author may not be used to 18 endorse or promote products derived from this software without 19 specific prior written permission. 20 21 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 23 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 24 DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, 25 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 26 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 27 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 29 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 30 IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 31 POSSIBILITY OF SUCH DAMAGE. */ 32 33 #include "config.h" 34 35 #include <sys/types.h> 36 37 #include "unwind.h" 38 #include "backtrace.h" 39 #include "internal.h" 40 41 /* The main backtrace_full routine. */ 42 43 /* Data passed through _Unwind_Backtrace. */ 44 45 struct backtrace_data 46 { 47 /* Number of frames to skip. */ 48 int skip; 49 /* Library state. */ 50 struct backtrace_state *state; 51 /* Callback routine. */ 52 backtrace_full_callback callback; 53 /* Error callback routine. */ 54 backtrace_error_callback error_callback; 55 /* Data to pass to callback routines. */ 56 void *data; 57 /* Value to return from backtrace_full. */ 58 int ret; 59 /* Whether there is any memory available. */ 60 int can_alloc; 61 }; 62 63 /* Unwind library callback routine. This is passed to 64 _Unwind_Backtrace. */ 65 66 static _Unwind_Reason_Code 67 unwind (struct _Unwind_Context *context, void *vdata) 68 { 69 struct backtrace_data *bdata = (struct backtrace_data *) vdata; 70 uintptr_t pc; 71 int ip_before_insn = 0; 72 73 #ifdef HAVE_GETIPINFO 74 pc = _Unwind_GetIPInfo (context, &ip_before_insn); 75 #else 76 pc = _Unwind_GetIP (context); 77 #endif 78 79 if (bdata->skip > 0) 80 { 81 --bdata->skip; 82 return _URC_NO_REASON; 83 } 84 85 if (!ip_before_insn) 86 --pc; 87 88 if (!bdata->can_alloc) 89 bdata->ret = bdata->callback (bdata->data, pc, NULL, 0, NULL); 90 else 91 bdata->ret = backtrace_pcinfo (bdata->state, pc, bdata->callback, 92 bdata->error_callback, bdata->data); 93 if (bdata->ret != 0) 94 return _URC_END_OF_STACK; 95 96 return _URC_NO_REASON; 97 } 98 99 /* Get a stack backtrace. */ 100 101 int 102 backtrace_full (struct backtrace_state *state, int skip, 103 backtrace_full_callback callback, 104 backtrace_error_callback error_callback, void *data) 105 { 106 struct backtrace_data bdata; 107 void *p; 108 109 bdata.skip = skip + 1; 110 bdata.state = state; 111 bdata.callback = callback; 112 bdata.error_callback = error_callback; 113 bdata.data = data; 114 bdata.ret = 0; 115 116 /* If we can't allocate any memory at all, don't try to produce 117 file/line information. */ 118 p = backtrace_alloc (state, 4096, NULL, NULL); 119 if (p == NULL) 120 bdata.can_alloc = 0; 121 else 122 { 123 backtrace_free (state, p, 4096, NULL, NULL); 124 bdata.can_alloc = 1; 125 } 126 127 _Unwind_Backtrace (unwind, &bdata); 128 return bdata.ret; 129 } 130