1 /*
2 * Copyright (C) 2014 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 #include <ctype.h>
18 #include <sys/types.h>
19 #include <unistd.h>
20
21 #include <string>
22 #include <vector>
23
24 #include <backtrace/backtrace_constants.h>
25 #include <backtrace/BacktraceMap.h>
26 #include <log/log.h>
27
28 #include "thread_utils.h"
29 #include "BacktraceImpl.h"
30
BacktraceMap(pid_t pid)31 BacktraceMap::BacktraceMap(pid_t pid) : pid_(pid) {
32 if (pid_ < 0) {
33 pid_ = getpid();
34 }
35 }
36
~BacktraceMap()37 BacktraceMap::~BacktraceMap() {
38 }
39
Find(uintptr_t addr)40 const backtrace_map_t* BacktraceMap::Find(uintptr_t addr) {
41 for (BacktraceMap::const_iterator it = begin();
42 it != end(); ++it) {
43 if (addr >= it->start && addr < it->end) {
44 return &*it;
45 }
46 }
47 return NULL;
48 }
49
ParseLine(const char * line,backtrace_map_t * map)50 bool BacktraceMap::ParseLine(const char* line, backtrace_map_t* map) {
51 unsigned long int start;
52 unsigned long int end;
53 char permissions[5];
54 int name_pos;
55
56 #if defined(__APPLE__)
57 // Mac OS vmmap(1) output:
58 // __TEXT 0009f000-000a1000 [ 8K 8K] r-x/rwx SM=COW /Volumes/android/dalvik-dev/out/host/darwin-x86/bin/libcorkscrew_test\n
59 // 012345678901234567890123456789012345678901234567890123456789
60 // 0 1 2 3 4 5
61 if (sscanf(line, "%*21c %lx-%lx [%*13c] %3c/%*3c SM=%*3c %n",
62 &start, &end, permissions, &name_pos) != 3) {
63 #else
64 // Linux /proc/<pid>/maps lines:
65 // 6f000000-6f01e000 rwxp 00000000 00:0c 16389419 /system/lib/libcomposer.so\n
66 // 012345678901234567890123456789012345678901234567890123456789
67 // 0 1 2 3 4 5
68 if (sscanf(line, "%lx-%lx %4s %*x %*x:%*x %*d%n",
69 &start, &end, permissions, &name_pos) != 3) {
70 #endif
71 return false;
72 }
73
74 map->start = start;
75 map->end = end;
76 map->flags = PROT_NONE;
77 if (permissions[0] == 'r') {
78 map->flags |= PROT_READ;
79 }
80 if (permissions[1] == 'w') {
81 map->flags |= PROT_WRITE;
82 }
83 if (permissions[2] == 'x') {
84 map->flags |= PROT_EXEC;
85 }
86
87 while (isspace(line[name_pos])) {
88 name_pos += 1;
89 }
90 map->name = line+name_pos;
91 if (!map->name.empty() && map->name[map->name.length()-1] == '\n') {
92 map->name.erase(map->name.length()-1);
93 }
94
95 ALOGV("Parsed map: start=%p, end=%p, flags=%x, name=%s",
96 reinterpret_cast<void*>(map->start), reinterpret_cast<void*>(map->end),
97 map->flags, map->name.c_str());
98 return true;
99 }
100
101 bool BacktraceMap::Build() {
102 #if defined(__APPLE__)
103 char cmd[sizeof(pid_t)*3 + sizeof("vmmap -w -resident -submap -allSplitLibs -interleaved ") + 1];
104 #else
105 char path[sizeof(pid_t)*3 + sizeof("/proc//maps") + 1];
106 #endif
107 char line[1024];
108
109 #if defined(__APPLE__)
110 // cmd is guaranteed to always be big enough to hold this string.
111 snprintf(cmd, sizeof(cmd), "vmmap -w -resident -submap -allSplitLibs -interleaved %d", pid_);
112 FILE* fp = popen(cmd, "r");
113 #else
114 // path is guaranteed to always be big enough to hold this string.
115 snprintf(path, sizeof(path), "/proc/%d/maps", pid_);
116 FILE* fp = fopen(path, "r");
117 #endif
118 if (fp == NULL) {
119 return false;
120 }
121
122 while(fgets(line, sizeof(line), fp)) {
123 backtrace_map_t map;
124 if (ParseLine(line, &map)) {
125 maps_.push_back(map);
126 }
127 }
128 #if defined(__APPLE__)
129 pclose(fp);
130 #else
131 fclose(fp);
132 #endif
133
134 return true;
135 }
136
137 #if defined(__APPLE__)
138 // Corkscrew and libunwind don't compile on the mac, so create a generic
139 // map object.
140 BacktraceMap* BacktraceMap::Create(pid_t pid, bool uncached) {
141 BacktraceMap* map = new BacktraceMap(pid);
142 if (!map->Build()) {
143 delete map;
144 return NULL;
145 }
146 return map;
147 }
148 #endif
149