platform_system_core/libbacktrace/BacktraceMap.cpp

147 lines
4.0 KiB
C++

/*
* Copyright (C) 2014 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <ctype.h>
#include <stdint.h>
#include <sys/types.h>
#include <unistd.h>
#include <backtrace/backtrace_constants.h>
#include <backtrace/BacktraceMap.h>
#include <log/log.h>
#include "thread_utils.h"
BacktraceMap::BacktraceMap(pid_t pid) : pid_(pid) {
if (pid_ < 0) {
pid_ = getpid();
}
}
BacktraceMap::~BacktraceMap() {
}
void BacktraceMap::FillIn(uintptr_t addr, backtrace_map_t* map) {
for (BacktraceMap::const_iterator it = begin();
it != end(); ++it) {
if (addr >= it->start && addr < it->end) {
*map = *it;
return;
}
}
*map = {};
}
bool BacktraceMap::ParseLine(const char* line, backtrace_map_t* map) {
unsigned long int start;
unsigned long int end;
char permissions[5];
int name_pos;
#if defined(__APPLE__)
// Mac OS vmmap(1) output:
// __TEXT 0009f000-000a1000 [ 8K 8K] r-x/rwx SM=COW /Volumes/android/dalvik-dev/out/host/darwin-x86/bin/libcorkscrew_test\n
// 012345678901234567890123456789012345678901234567890123456789
// 0 1 2 3 4 5
if (sscanf(line, "%*21c %lx-%lx [%*13c] %3c/%*3c SM=%*3c %n",
&start, &end, permissions, &name_pos) != 3) {
#else
// Linux /proc/<pid>/maps lines:
// 6f000000-6f01e000 rwxp 00000000 00:0c 16389419 /system/lib/libcomposer.so\n
// 012345678901234567890123456789012345678901234567890123456789
// 0 1 2 3 4 5
if (sscanf(line, "%lx-%lx %4s %*x %*x:%*x %*d%n",
&start, &end, permissions, &name_pos) != 3) {
#endif
return false;
}
map->start = start;
map->end = end;
map->flags = PROT_NONE;
if (permissions[0] == 'r') {
map->flags |= PROT_READ;
}
if (permissions[1] == 'w') {
map->flags |= PROT_WRITE;
}
if (permissions[2] == 'x') {
map->flags |= PROT_EXEC;
}
while (isspace(line[name_pos])) {
name_pos += 1;
}
map->name = line+name_pos;
if (!map->name.empty() && map->name[map->name.length()-1] == '\n') {
map->name.erase(map->name.length()-1);
}
ALOGV("Parsed map: start=%p, end=%p, flags=%x, name=%s",
reinterpret_cast<void*>(map->start), reinterpret_cast<void*>(map->end),
map->flags, map->name.c_str());
return true;
}
bool BacktraceMap::Build() {
#if defined(__APPLE__)
char cmd[sizeof(pid_t)*3 + sizeof("vmmap -w -resident -submap -allSplitLibs -interleaved ") + 1];
#else
char path[sizeof(pid_t)*3 + sizeof("/proc//maps") + 1];
#endif
char line[1024];
#if defined(__APPLE__)
// cmd is guaranteed to always be big enough to hold this string.
snprintf(cmd, sizeof(cmd), "vmmap -w -resident -submap -allSplitLibs -interleaved %d", pid_);
FILE* fp = popen(cmd, "r");
#else
// path is guaranteed to always be big enough to hold this string.
snprintf(path, sizeof(path), "/proc/%d/maps", pid_);
FILE* fp = fopen(path, "r");
#endif
if (fp == nullptr) {
return false;
}
while(fgets(line, sizeof(line), fp)) {
backtrace_map_t map;
if (ParseLine(line, &map)) {
maps_.push_back(map);
}
}
#if defined(__APPLE__)
pclose(fp);
#else
fclose(fp);
#endif
return true;
}
#if defined(__APPLE__)
// Corkscrew and libunwind don't compile on the mac, so create a generic
// map object.
BacktraceMap* BacktraceMap::Create(pid_t pid, bool uncached) {
BacktraceMap* map = new BacktraceMap(pid);
if (!map->Build()) {
delete map;
return nullptr;
}
return map;
}
#endif