1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28 #include <unwind.h>
29 #include <sys/types.h>
30
31 // =============================================================================
32 // stack trace functions
33 // =============================================================================
34
35 typedef struct
36 {
37 size_t count;
38 intptr_t* addrs;
39 } stack_crawl_state_t;
40
41
42 /* depends how the system includes define this */
43 #ifdef HAVE_UNWIND_CONTEXT_STRUCT
44 typedef struct _Unwind_Context __unwind_context;
45 #else
46 typedef _Unwind_Context __unwind_context;
47 #endif
48
trace_function(__unwind_context * context,void * arg)49 static _Unwind_Reason_Code trace_function(__unwind_context *context, void *arg)
50 {
51 stack_crawl_state_t* state = (stack_crawl_state_t*)arg;
52 if (state->count) {
53 intptr_t ip = (intptr_t)_Unwind_GetIP(context);
54 if (ip) {
55 state->addrs[0] = ip;
56 state->addrs++;
57 state->count--;
58 return _URC_NO_REASON;
59 }
60 }
61 /*
62 * If we run out of space to record the address or 0 has been seen, stop
63 * unwinding the stack.
64 */
65 return _URC_END_OF_STACK;
66 }
67
68 __LIBC_HIDDEN__
get_backtrace(intptr_t * addrs,size_t max_entries)69 int get_backtrace(intptr_t* addrs, size_t max_entries)
70 {
71 stack_crawl_state_t state;
72 state.count = max_entries;
73 state.addrs = (intptr_t*)addrs;
74 _Unwind_Backtrace(trace_function, (void*)&state);
75 return max_entries - state.count;
76 }
77