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/*
* Copyright (C) 2016 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 <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>
#include <android-base/unique_fd.h>
#include <cctype>
#include <memory>
#include <string>
#include <vector>
#include <unwindstack/Elf.h>
#include <unwindstack/Maps.h>
#include <unwindstack/Memory.h>
namespace unwindstack {
MapInfo* Maps::Find(uint64_t pc) {
if (maps_.empty()) {
return nullptr;
}
size_t first = 0;
size_t last = maps_.size();
while (first < last) {
size_t index = (first + last) / 2;
MapInfo* cur = maps_[index];
if (pc >= cur->start && pc < cur->end) {
return cur;
} else if (pc < cur->start) {
last = index;
} else {
first = index + 1;
}
}
return nullptr;
}
// Assumes that line does not end in '\n'.
static MapInfo* InternalParseLine(const char* line) {
// Do not use a sscanf implementation since it is not performant.
// Example linux /proc/<pid>/maps lines:
// 6f000000-6f01e000 rwxp 00000000 00:0c 16389419 /system/lib/libcomposer.so
char* str;
const char* old_str = line;
uint64_t start = strtoull(old_str, &str, 16);
if (old_str == str || *str++ != '-') {
return nullptr;
}
old_str = str;
uint64_t end = strtoull(old_str, &str, 16);
if (old_str == str || !std::isspace(*str++)) {
return nullptr;
}
while (std::isspace(*str)) {
str++;
}
// Parse permissions data.
if (*str == '\0') {
return nullptr;
}
uint16_t flags = 0;
if (*str == 'r') {
flags |= PROT_READ;
} else if (*str != '-') {
return nullptr;
}
str++;
if (*str == 'w') {
flags |= PROT_WRITE;
} else if (*str != '-') {
return nullptr;
}
str++;
if (*str == 'x') {
flags |= PROT_EXEC;
} else if (*str != '-') {
return nullptr;
}
str++;
if (*str != 'p' && *str != 's') {
return nullptr;
}
str++;
if (!std::isspace(*str++)) {
return nullptr;
}
old_str = str;
uint64_t offset = strtoull(old_str, &str, 16);
if (old_str == str || !std::isspace(*str)) {
return nullptr;
}
// Ignore the 00:00 values.
old_str = str;
(void)strtoull(old_str, &str, 16);
if (old_str == str || *str++ != ':') {
return nullptr;
}
if (std::isspace(*str)) {
return nullptr;
}
// Skip the inode.
old_str = str;
(void)strtoull(str, &str, 16);
if (old_str == str || !std::isspace(*str++)) {
return nullptr;
}
// Skip decimal digit.
old_str = str;
(void)strtoull(old_str, &str, 10);
if (old_str == str || (!std::isspace(*str) && *str != '\0')) {
return nullptr;
}
while (std::isspace(*str)) {
str++;
}
if (*str == '\0') {
return new MapInfo(start, end, offset, flags, "");
}
// Save the name data.
std::string name(str);
// Mark a device map in /dev/ and not in /dev/ashmem/ specially.
if (name.substr(0, 5) == "/dev/" && name.substr(5, 7) != "ashmem/") {
flags |= MAPS_FLAGS_DEVICE_MAP;
}
return new MapInfo(start, end, offset, flags, name);
}
bool Maps::Parse() {
int fd = open(GetMapsFile().c_str(), O_RDONLY | O_CLOEXEC);
if (fd == -1) {
return false;
}
bool return_value = true;
char buffer[2048];
size_t leftover = 0;
while (true) {
ssize_t bytes = read(fd, &buffer[leftover], 2048 - leftover);
if (bytes == -1) {
return_value = false;
break;
}
if (bytes == 0) {
break;
}
bytes += leftover;
char* line = buffer;
while (bytes > 0) {
char* newline = static_cast<char*>(memchr(line, '\n', bytes));
if (newline == nullptr) {
memmove(buffer, line, bytes);
break;
}
*newline = '\0';
MapInfo* map_info = InternalParseLine(line);
if (map_info == nullptr) {
return_value = false;
break;
}
maps_.push_back(map_info);
bytes -= newline - line + 1;
line = newline + 1;
}
leftover = bytes;
}
close(fd);
return return_value;
}
Maps::~Maps() {
for (auto& map : maps_) {
delete map;
}
}
bool BufferMaps::Parse() {
const char* start_of_line = buffer_;
do {
std::string line;
const char* end_of_line = strchr(start_of_line, '\n');
if (end_of_line == nullptr) {
line = start_of_line;
} else {
line = std::string(start_of_line, end_of_line - start_of_line);
end_of_line++;
}
MapInfo* map_info = InternalParseLine(line.c_str());
if (map_info == nullptr) {
return false;
}
maps_.push_back(map_info);
start_of_line = end_of_line;
} while (start_of_line != nullptr && *start_of_line != '\0');
return true;
}
const std::string RemoteMaps::GetMapsFile() const {
return "/proc/" + std::to_string(pid_) + "/maps";
}
bool OfflineMaps::Parse() {
// Format of maps information:
// <uint64_t> StartOffset
// <uint64_t> EndOffset
// <uint64_t> offset
// <uint16_t> flags
// <uint16_t> MapNameLength
// <VariableLengthValue> MapName
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(file_.c_str(), O_RDONLY)));
if (fd == -1) {
return false;
}
std::vector<char> name;
while (true) {
uint64_t start;
ssize_t bytes = TEMP_FAILURE_RETRY(read(fd, &start, sizeof(start)));
if (bytes == 0) {
break;
}
if (bytes == -1 || bytes != sizeof(start)) {
return false;
}
uint64_t end;
bytes = TEMP_FAILURE_RETRY(read(fd, &end, sizeof(end)));
if (bytes == -1 || bytes != sizeof(end)) {
return false;
}
uint64_t offset;
bytes = TEMP_FAILURE_RETRY(read(fd, &offset, sizeof(offset)));
if (bytes == -1 || bytes != sizeof(offset)) {
return false;
}
uint16_t flags;
bytes = TEMP_FAILURE_RETRY(read(fd, &flags, sizeof(flags)));
if (bytes == -1 || bytes != sizeof(flags)) {
return false;
}
uint16_t len;
bytes = TEMP_FAILURE_RETRY(read(fd, &len, sizeof(len)));
if (bytes == -1 || bytes != sizeof(len)) {
return false;
}
if (len > 0) {
name.resize(len);
bytes = TEMP_FAILURE_RETRY(read(fd, name.data(), len));
if (bytes == -1 || bytes != len) {
return false;
}
maps_.push_back(new MapInfo(start, end, offset, flags, std::string(name.data(), len)));
} else {
maps_.push_back(new MapInfo(start, end, offset, flags, ""));
}
}
return true;
}
} // namespace unwindstack