CallStack.cpp revision f013e1afd1e68af5e3b868c26a653bbfb39538f8 
1/*
2 * Copyright (C) 2007 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define LOG_TAG "CallStack"
18
19#include <string.h>
20#include <stdlib.h>
21#include <stdio.h>
22
23#if HAVE_DLADDR
24#include <dlfcn.h>
25#endif
26
27#if HAVE_CXXABI
28#include <cxxabi.h>
29#endif
30
31#include <unwind.h>
32
33#include <utils/Log.h>
34#include <utils/Errors.h>
35#include <utils/CallStack.h>
36#include <utils/threads.h>
37
38
39/*****************************************************************************/
40namespace android {
41
42
43typedef struct {
44    size_t count;
45    size_t ignore;
46    const void** addrs;
47} stack_crawl_state_t;
48
49static
50_Unwind_Reason_Code trace_function(_Unwind_Context *context, void *arg)
51{
52    stack_crawl_state_t* state = (stack_crawl_state_t*)arg;
53    if (state->count) {
54        void* ip = (void*)_Unwind_GetIP(context);
55        if (ip) {
56            if (state->ignore) {
57                state->ignore--;
58            } else {
59                state->addrs[0] = ip;
60                state->addrs++;
61                state->count--;
62            }
63        }
64    }
65    return _URC_NO_REASON;
66}
67
68static
69int backtrace(const void** addrs, size_t ignore, size_t size)
70{
71    stack_crawl_state_t state;
72    state.count = size;
73    state.ignore = ignore;
74    state.addrs = addrs;
75    _Unwind_Backtrace(trace_function, (void*)&state);
76    return size - state.count;
77}
78
79/*****************************************************************************/
80
81static
82const char *lookup_symbol(const void* addr, void **offset, char* name, size_t bufSize)
83{
84#if HAVE_DLADDR
85    Dl_info info;
86    if (dladdr(addr, &info)) {
87        *offset = info.dli_saddr;
88        return info.dli_sname;
89    }
90#endif
91    return NULL;
92}
93
94static
95int32_t linux_gcc_demangler(const char *mangled_name, char *unmangled_name, size_t buffersize)
96{
97    size_t out_len = 0;
98#if HAVE_CXXABI
99    int status = 0;
100    char *demangled = abi::__cxa_demangle(mangled_name, 0, &out_len, &status);
101    if (status == 0) {
102        // OK
103        if (out_len < buffersize) memcpy(unmangled_name, demangled, out_len);
104        else out_len = 0;
105        free(demangled);
106    } else {
107        out_len = 0;
108    }
109#endif
110    return out_len;
111}
112
113/*****************************************************************************/
114
115class MapInfo {
116    struct mapinfo {
117        struct mapinfo *next;
118        uint64_t start;
119        uint64_t end;
120        char name[];
121    };
122
123    const char *map_to_name(uint64_t pc, const char* def) {
124        mapinfo* mi = getMapInfoList();
125        while(mi) {
126            if ((pc >= mi->start) && (pc < mi->end))
127                return mi->name;
128            mi = mi->next;
129        }
130        return def;
131    }
132
133    mapinfo *parse_maps_line(char *line) {
134        mapinfo *mi;
135        int len = strlen(line);
136        if (len < 1) return 0;
137        line[--len] = 0;
138        if (len < 50) return 0;
139        if (line[20] != 'x') return 0;
140        mi = (mapinfo*)malloc(sizeof(mapinfo) + (len - 47));
141        if (mi == 0) return 0;
142        mi->start = strtoull(line, 0, 16);
143        mi->end = strtoull(line + 9, 0, 16);
144        mi->next = 0;
145        strcpy(mi->name, line + 49);
146        return mi;
147    }
148
149    mapinfo* getMapInfoList() {
150        Mutex::Autolock _l(mLock);
151        if (milist == 0) {
152            char data[1024];
153            FILE *fp;
154            sprintf(data, "/proc/%d/maps", getpid());
155            fp = fopen(data, "r");
156            if (fp) {
157                while(fgets(data, 1024, fp)) {
158                    mapinfo *mi = parse_maps_line(data);
159                    if(mi) {
160                        mi->next = milist;
161                        milist = mi;
162                    }
163                }
164                fclose(fp);
165            }
166        }
167        return milist;
168    }
169    mapinfo*    milist;
170    Mutex       mLock;
171    static MapInfo sMapInfo;
172
173public:
174    MapInfo()
175     : milist(0) {
176    }
177
178    ~MapInfo() {
179        while (milist) {
180            mapinfo *next = milist->next;
181            free(milist);
182            milist = next;
183        }
184    }
185
186    static const char *mapAddressToName(const void* pc, const char* def) {
187        return sMapInfo.map_to_name((uint64_t)pc, def);
188    }
189
190};
191
192/*****************************************************************************/
193
194MapInfo MapInfo::sMapInfo;
195
196/*****************************************************************************/
197
198CallStack::CallStack()
199    : mCount(0)
200{
201}
202
203CallStack::CallStack(const CallStack& rhs)
204    : mCount(rhs.mCount)
205{
206    if (mCount) {
207        memcpy(mStack, rhs.mStack, mCount*sizeof(void*));
208    }
209}
210
211CallStack::~CallStack()
212{
213}
214
215CallStack& CallStack::operator = (const CallStack& rhs)
216{
217    mCount = rhs.mCount;
218    if (mCount) {
219        memcpy(mStack, rhs.mStack, mCount*sizeof(void*));
220    }
221    return *this;
222}
223
224bool CallStack::operator == (const CallStack& rhs) const {
225    if (mCount != rhs.mCount)
226        return false;
227    return !mCount || (memcmp(mStack, rhs.mStack, mCount*sizeof(void*)) == 0);
228}
229
230bool CallStack::operator != (const CallStack& rhs) const {
231    return !operator == (rhs);
232}
233
234bool CallStack::operator < (const CallStack& rhs) const {
235    if (mCount != rhs.mCount)
236        return mCount < rhs.mCount;
237    return memcmp(mStack, rhs.mStack, mCount*sizeof(void*)) < 0;
238}
239
240bool CallStack::operator >= (const CallStack& rhs) const {
241    return !operator < (rhs);
242}
243
244bool CallStack::operator > (const CallStack& rhs) const {
245    if (mCount != rhs.mCount)
246        return mCount > rhs.mCount;
247    return memcmp(mStack, rhs.mStack, mCount*sizeof(void*)) > 0;
248}
249
250bool CallStack::operator <= (const CallStack& rhs) const {
251    return !operator > (rhs);
252}
253
254const void* CallStack::operator [] (int index) const {
255    if (index >= int(mCount))
256        return 0;
257    return mStack[index];
258}
259
260
261void CallStack::clear()
262{
263    mCount = 0;
264}
265
266void CallStack::update(int32_t ignoreDepth, int32_t maxDepth)
267{
268    if (maxDepth > MAX_DEPTH)
269        maxDepth = MAX_DEPTH;
270    mCount = backtrace(mStack, ignoreDepth, maxDepth);
271}
272
273// Return the stack frame name on the designated level
274String8 CallStack::toStringSingleLevel(const char* prefix, int32_t level) const
275{
276    String8 res;
277    char namebuf[1024];
278    char tmp[256];
279    char tmp1[32];
280    char tmp2[32];
281    void *offs;
282
283    const void* ip = mStack[level];
284    if (!ip) return res;
285
286    if (prefix) res.append(prefix);
287    snprintf(tmp1, 32, "#%02d  ", level);
288    res.append(tmp1);
289
290    const char* name = lookup_symbol(ip, &offs, namebuf, sizeof(namebuf));
291    if (name) {
292        if (linux_gcc_demangler(name, tmp, 256) != 0)
293            name = tmp;
294        snprintf(tmp1, 32, "0x%p: <", ip);
295        snprintf(tmp2, 32, ">+0x%p", offs);
296        res.append(tmp1);
297        res.append(name);
298        res.append(tmp2);
299    } else {
300        name = MapInfo::mapAddressToName(ip, "<unknown>");
301        snprintf(tmp, 256, "pc %p  %s", ip, name);
302        res.append(tmp);
303    }
304    res.append("\n");
305
306    return res;
307}
308
309// Dump a stack trace to the log
310void CallStack::dump(const char* prefix) const
311{
312    /*
313     * Sending a single long log may be truncated since the stack levels can
314     * get very deep. So we request function names of each frame individually.
315     */
316    for (int i=0; i<int(mCount); i++) {
317        LOGD("%s", toStringSingleLevel(prefix, i).string());
318    }
319}
320
321// Return a string (possibly very long) containing the complete stack trace
322String8 CallStack::toString(const char* prefix) const
323{
324    String8 res;
325
326    for (int i=0; i<int(mCount); i++) {
327        res.append(toStringSingleLevel(prefix, i).string());
328    }
329
330    return res;
331}
332
333/*****************************************************************************/
334
335}; // namespace android
336