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Merge "Move out the code to parse block map in MemMap"

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This commit is contained in:
Tianjie Xu
2019-03-26 21:52:40 +00:00
committed by Gerrit Code Review
parent 6287253eb4 625c588c0f
commit f1cbd2f7f2
3 changed files with 192 additions and 71 deletions
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51
otautil/include/otautil/sysutil.h
View File

@@ -22,6 +22,57 @@
#include <string>
#include <vector>
#include "rangeset.h"
// This class holds the content of a block map file.
class BlockMapData {
public:
// A "block map" which looks like this (from uncrypt/uncrypt.cpp):
//
// /dev/block/platform/msm_sdcc.1/by-name/userdata # block device
// 49652 4096 # file size in bytes, block size
// 3 # count of block ranges
// 1000 1008 # block range 0
// 2100 2102 # ... block range 1
// 30 33 # ... block range 2
//
// Each block range represents a half-open interval; the line "30 33" reprents the blocks
// [30, 31, 32].
static BlockMapData ParseBlockMapFile(const std::string& block_map_path);
explicit operator bool() const {
return !path_.empty();
}
std::string path() const {
return path_;
}
uint64_t file_size() const {
return file_size_;
}
uint32_t block_size() const {
return block_size_;
}
RangeSet block_ranges() const {
return block_ranges_;
}
private:
BlockMapData() = default;
BlockMapData(const std::string& path, uint64_t file_size, uint32_t block_size,
RangeSet block_ranges)
: path_(path),
file_size_(file_size),
block_size_(block_size),
block_ranges_(std::move(block_ranges)) {}
std::string path_;
uint64_t file_size_ = 0;
uint32_t block_size_ = 0;
RangeSet block_ranges_;
};
/*
* Use this to keep track of mapped segments.
*/

151
otautil/sysutil.cpp
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@@ -18,12 +18,13 @@
#include <errno.h> // TEMP_FAILURE_RETRY
#include <fcntl.h>
#include <stdint.h> // SIZE_MAX
#include <inttypes.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <algorithm>
#include <limits>
#include <string>
#include <vector>
@@ -34,6 +35,68 @@
#include <android-base/unique_fd.h>
#include <cutils/android_reboot.h>
BlockMapData BlockMapData::ParseBlockMapFile(const std::string& block_map_path) {
std::string content;
if (!android::base::ReadFileToString(block_map_path, &content)) {
LOG(ERROR) << "Failed to read " << block_map_path;
return {};
}
std::vector<std::string> lines = android::base::Split(android::base::Trim(content), "\n");
if (lines.size() < 4) {
LOG(ERROR) << "Block map file is too short: " << lines.size();
return {};
}
const std::string& block_dev = lines[0];
uint64_t file_size;
uint32_t blksize;
if (sscanf(lines[1].c_str(), "%" SCNu64 "%" SCNu32, &file_size, &blksize) != 2) {
LOG(ERROR) << "Failed to parse file size and block size: " << lines[1];
return {};
}
if (file_size == 0 || blksize == 0) {
LOG(ERROR) << "Invalid size in block map file: size " << file_size << ", blksize " << blksize;
return {};
}
size_t range_count;
if (sscanf(lines[2].c_str(), "%zu", &range_count) != 1) {
LOG(ERROR) << "Failed to parse block map header: " << lines[2];
return {};
}
uint64_t blocks = ((file_size - 1) / blksize) + 1;
if (blocks > std::numeric_limits<uint32_t>::max() || range_count == 0 ||
lines.size() != 3 + range_count) {
LOG(ERROR) << "Invalid data in block map file: size " << file_size << ", blksize " << blksize
<< ", range_count " << range_count << ", lines " << lines.size();
return {};
}
RangeSet ranges;
uint64_t remaining_blocks = blocks;
for (size_t i = 0; i < range_count; ++i) {
const std::string& line = lines[i + 3];
uint64_t start, end;
if (sscanf(line.c_str(), "%" SCNu64 "%" SCNu64, &start, &end) != 2) {
LOG(ERROR) << "failed to parse range " << i << ": " << line;
return {};
}
uint64_t range_blocks = end - start;
if (end <= start || range_blocks > remaining_blocks) {
LOG(ERROR) << "Invalid range: " << start << " " << end;
return {};
}
ranges.PushBack({ start, end });
remaining_blocks -= range_blocks;
}
return BlockMapData(block_dev, file_size, blksize, std::move(ranges));
}
bool MemMapping::MapFD(int fd) {
struct stat sb;
if (fstat(fd, &sb) == -1) {
@@ -55,115 +118,61 @@ bool MemMapping::MapFD(int fd) {
return true;
}
// A "block map" which looks like this (from uncrypt/uncrypt.cpp):
//
// /dev/block/platform/msm_sdcc.1/by-name/userdata # block device
// 49652 4096 # file size in bytes, block size
// 3 # count of block ranges
// 1000 1008 # block range 0
// 2100 2102 # ... block range 1
// 30 33 # ... block range 2
//
// Each block range represents a half-open interval; the line "30 33" reprents the blocks
// [30, 31, 32].
bool MemMapping::MapBlockFile(const std::string& filename) {
std::string content;
if (!android::base::ReadFileToString(filename, &content)) {
PLOG(ERROR) << "Failed to read " << filename;
auto block_map_data = BlockMapData::ParseBlockMapFile(filename);
if (!block_map_data) {
return false;
}
std::vector<std::string> lines = android::base::Split(android::base::Trim(content), "\n");
if (lines.size() < 4) {
LOG(ERROR) << "Block map file is too short: " << lines.size();
return false;
}
size_t size;
size_t blksize;
if (sscanf(lines[1].c_str(), "%zu %zu", &size, &blksize) != 2) {
LOG(ERROR) << "Failed to parse file size and block size: " << lines[1];
return false;
}
size_t range_count;
if (sscanf(lines[2].c_str(), "%zu", &range_count) != 1) {
LOG(ERROR) << "Failed to parse block map header: " << lines[2];
return false;
}
size_t blocks;
if (blksize != 0) {
blocks = ((size - 1) / blksize) + 1;
}
if (size == 0 || blksize == 0 || blocks > SIZE_MAX / blksize || range_count == 0 ||
lines.size() != 3 + range_count) {
LOG(ERROR) << "Invalid data in block map file: size " << size << ", blksize " << blksize
<< ", range_count " << range_count << ", lines " << lines.size();
if (block_map_data.file_size() > std::numeric_limits<size_t>::max()) {
LOG(ERROR) << "File size is too large for mmap " << block_map_data.file_size();
return false;
}
// Reserve enough contiguous address space for the whole file.
uint32_t blksize = block_map_data.block_size();
uint64_t blocks = ((block_map_data.file_size() - 1) / blksize) + 1;
void* reserve = mmap(nullptr, blocks * blksize, PROT_NONE, MAP_PRIVATE | MAP_ANON, -1, 0);
if (reserve == MAP_FAILED) {
PLOG(ERROR) << "failed to reserve address space";
return false;
}
const std::string& block_dev = lines[0];
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(block_dev.c_str(), O_RDONLY)));
android::base::unique_fd fd(TEMP_FAILURE_RETRY(open(block_map_data.path().c_str(), O_RDONLY)));
if (fd == -1) {
PLOG(ERROR) << "failed to open block device " << block_dev;
PLOG(ERROR) << "failed to open block device " << block_map_data.path();
munmap(reserve, blocks * blksize);
return false;
}
ranges_.clear();
unsigned char* next = static_cast<unsigned char*>(reserve);
auto next = static_cast<unsigned char*>(reserve);
size_t remaining_size = blocks * blksize;
bool success = true;
for (size_t i = 0; i < range_count; ++i) {
const std::string& line = lines[i + 3];
size_t start, end;
if (sscanf(line.c_str(), "%zu %zu\n", &start, &end) != 2) {
LOG(ERROR) << "failed to parse range " << i << ": " << line;
success = false;
break;
}
for (const auto& [start, end] : block_map_data.block_ranges()) {
size_t range_size = (end - start) * blksize;
if (end <= start || (end - start) > SIZE_MAX / blksize || range_size > remaining_size) {
LOG(ERROR) << "Invalid range: " << start << " " << end;
success = false;
break;
}
void* range_start = mmap(next, range_size, PROT_READ, MAP_PRIVATE | MAP_FIXED, fd,
static_cast<off_t>(start) * blksize);
if (range_start == MAP_FAILED) {
PLOG(ERROR) << "failed to map range " << i << ": " << line;
success = false;
break;
PLOG(ERROR) << "failed to map range " << start << ": " << end;
munmap(reserve, blocks * blksize);
return false;
}
ranges_.emplace_back(MappedRange{ range_start, range_size });
next += range_size;
remaining_size -= range_size;
}
if (success && remaining_size != 0) {
if (remaining_size != 0) {
LOG(ERROR) << "Invalid ranges: remaining_size " << remaining_size;
success = false;
}
if (!success) {
munmap(reserve, blocks * blksize);
return false;
}
addr = static_cast<unsigned char*>(reserve);
length = size;
length = block_map_data.file_size();
LOG(INFO) << "mmapped " << range_count << " ranges";
LOG(INFO) << "mmapped " << block_map_data.block_ranges().size() << " ranges";
return true;
}

61
tests/unit/sysutil_test.cpp
View File

@@ -17,8 +17,10 @@
#include <string>
#include <android-base/file.h>
#include <android-base/strings.h>
#include <gtest/gtest.h>
#include "otautil/rangeset.h"
#include "otautil/sysutil.h"
TEST(SysUtilTest, InvalidArgs) {
@@ -28,6 +30,65 @@ TEST(SysUtilTest, InvalidArgs) {
ASSERT_FALSE(mapping.MapFile(""));
}
TEST(SysUtilTest, ParseBlockMapFile_smoke) {
std::vector<std::string> content = {
"/dev/abc", "49652 4096", "3", "1000 1008", "2100 2102", "30 33",
};
TemporaryFile temp_file;
ASSERT_TRUE(android::base::WriteStringToFile(android::base::Join(content, '\n'), temp_file.path));
auto block_map_data = BlockMapData::ParseBlockMapFile(temp_file.path);
ASSERT_EQ("/dev/abc", block_map_data.path());
ASSERT_EQ(49652, block_map_data.file_size());
ASSERT_EQ(4096, block_map_data.block_size());
ASSERT_EQ(RangeSet(std::vector<Range>{
{ 1000, 1008 },
{ 2100, 2102 },
{ 30, 33 },
}),
block_map_data.block_ranges());
}
TEST(SysUtilTest, ParseBlockMapFile_invalid_line_count) {
std::vector<std::string> content = {
"/dev/abc", "49652 4096", "2", "1000 1008", "2100 2102", "30 33",
};
TemporaryFile temp_file;
ASSERT_TRUE(android::base::WriteStringToFile(android::base::Join(content, '\n'), temp_file.path));
auto block_map_data1 = BlockMapData::ParseBlockMapFile(temp_file.path);
ASSERT_FALSE(block_map_data1);
}
TEST(SysUtilTest, ParseBlockMapFile_invalid_size) {
std::vector<std::string> content = {
"/dev/abc",
"42949672950 4294967295",
"1",
"0 9",
};
TemporaryFile temp_file;
ASSERT_TRUE(android::base::WriteStringToFile(android::base::Join(content, '\n'), temp_file.path));
auto block_map_data = BlockMapData::ParseBlockMapFile(temp_file.path);
ASSERT_EQ("/dev/abc", block_map_data.path());
ASSERT_EQ(42949672950, block_map_data.file_size());
ASSERT_EQ(4294967295, block_map_data.block_size());
content[1] = "42949672950 4294967296";
ASSERT_TRUE(android::base::WriteStringToFile(android::base::Join(content, '\n'), temp_file.path));
auto large_block_size = BlockMapData::ParseBlockMapFile(temp_file.path);
ASSERT_FALSE(large_block_size);
content[1] = "4294967296 1";
ASSERT_TRUE(android::base::WriteStringToFile(android::base::Join(content, '\n'), temp_file.path));
auto too_many_blocks = BlockMapData::ParseBlockMapFile(temp_file.path);
ASSERT_FALSE(too_many_blocks);
}
TEST(SysUtilTest, MapFileRegularFile) {
TemporaryFile temp_file1;
std::string content = "abc";