diff options
Diffstat (limited to 'tools')
36 files changed, 5485 insertions, 0 deletions
diff --git a/tools/relocation_packer/BUILD.gn b/tools/relocation_packer/BUILD.gn new file mode 100644 index 0000000..0b29c91 --- /dev/null +++ b/tools/relocation_packer/BUILD.gn @@ -0,0 +1,148 @@ +# Copyright 2014 The Chromium Authors. All rights reserved. +# Use of this source code is governed by a BSD-style license that can be +# found in the LICENSE file. + +import("config.gni") +import("//testing/test.gni") + +assert(relocation_packing_supported) + +if (target_arch == "arm") { + target_define = "TARGET_ARM" +} else if (target_arch == "arm64") { + target_define = "TARGET_ARM64" +} + +if (current_toolchain == host_toolchain) { + # GYP: //tools/relocation_packer/relocation_packer.gyp:lib_relocation_packer + source_set("lib_relocation_packer") { + defines = [ target_define ] + deps = [ + "//third_party/elfutils:libelf", + ] + configs -= [ "//build/config/compiler:chromium_code" ] + configs += [ "//build/config/compiler:no_chromium_code" ] + sources = [ + "src/debug.cc", + "src/delta_encoder.cc", + "src/elf_file.cc", + "src/leb128.cc", + "src/packer.cc", + "src/sleb128.cc", + "src/run_length_encoder.cc", + ] + } + + # GYP: //tools/relocation_packer/relocation_packer.gyp:relocation_packer + executable("relocation_packer") { + defines = [ target_define ] + deps = [ + ":lib_relocation_packer", + "//third_party/elfutils:libelf", + ] + sources = [ + "src/main.cc", + ] + } + + # GYP: //tools/relocation_packer/relocation_packer.gyp:relocation_packer_unittests + test("relocation_packer_unittests") { + sources = [ + "src/debug_unittest.cc", + "src/delta_encoder_unittest.cc", + "src/elf_file_unittest.cc", + "src/leb128_unittest.cc", + "src/packer_unittest.cc", + "src/sleb128_unittest.cc", + "src/run_length_encoder_unittest.cc", + "src/run_all_unittests.cc", + ] + rebased_test_data = rebase_path("test_data", root_build_dir) + data = [ + "test_data/elf_file_unittest_relocs_arm32.so", + "test_data/elf_file_unittest_relocs_arm32_packed.so", + "test_data/elf_file_unittest_relocs_arm64.so", + "test_data/elf_file_unittest_relocs_arm64_packed.so", + ] + defines = [ + target_define, + "INTERMEDIATE_DIR=\"$rebased_test_data\"", + ] + include_dirs = [ "//" ] + deps = [ + ":lib_relocation_packer", + ":relocation_packer_test_data", + "//testing:gtest", + ] + } +} + +if (current_toolchain == default_toolchain && + (target_arch == "arm" || target_arch == "arm64")) { + # Targets to build test data. These participate only in building test + # data for use with elf_file_unittest.cc, and are not part of the main + # relocation packer build. Unit test data files are checked in to the + # source tree as 'golden' data, and are not generated 'on the fly' by + # the build. + # + # See test_data/generate_elf_file_unittest_relocs.sh for instructions. + + # GYP: //tools/relocation_packer/relocation_packer.gyp:relocation_packer_test_data + shared_library("relocation_packer_test_data") { + cflags = [ + "-O0", + "-g0", + ] + sources = [ + "test_data/elf_file_unittest_relocs.cc", + ] + } + + # GYP: //tools/relocation_packer/relocation_packer.gyp:relocation_packer_unittests_test_data + action("relocation_packer_unittests_test_data") { + script = "test_data/generate_elf_file_unittest_relocs.py" + test_file = "$root_build_dir/librelocation_packer_test_data.so" + if (target_arch == "arm") { + added_section = ".android.rel.dyn" + packed_output = "elf_file_unittest_relocs_arm32_packed.so" + unpacked_output = "elf_file_unittest_relocs_arm32.so" + } else if (target_arch == "arm64") { + added_section = ".android.rela.dyn" + packed_output = "elf_file_unittest_relocs_arm64_packed.so" + unpacked_output = "elf_file_unittest_relocs_arm64.so" + } else { + assert(false, "Unsupported target arch for relocation packer") + } + + packed_output = "$root_build_dir/$packed_output" + unpacked_output = "$root_build_dir/$unpacked_output" + + inputs = [ + test_file, + ] + + deps = [ + ":relocation_packer_test_data", + ":relocation_packer($host_toolchain)", + ] + + outputs = [ + packed_output, + unpacked_output, + ] + + args = [ + "--android-pack-relocations", + rebase_path(relocation_packer_exe, root_build_dir), + "--android-objcopy", + rebase_path(android_objcopy, root_build_dir), + "--added-section=$added_section", + "--test-file", + rebase_path(test_file, root_build_dir), + "--packed-output", + rebase_path(packed_output, root_build_dir), + "--unpacked-output", + rebase_path(unpacked_output, root_build_dir), + ] + } +} diff --git a/tools/relocation_packer/LICENSE b/tools/relocation_packer/LICENSE new file mode 100644 index 0000000..972bb2e --- /dev/null +++ b/tools/relocation_packer/LICENSE @@ -0,0 +1,27 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/tools/relocation_packer/README.TXT b/tools/relocation_packer/README.TXT new file mode 100644 index 0000000..071ab5d --- /dev/null +++ b/tools/relocation_packer/README.TXT @@ -0,0 +1,135 @@ +Introduction: +------------- + +Relative relocations are the bulk of dynamic relocations (the .rel.dyn +or .rela.dyn sections) in libchrome.<version>.so. The ELF standard +representation of them is wasteful. + +Packing uses a combination of run length encoding, delta encoding, and LEB128 +encoding to store them more efficiently. Packed relocations are placed in +a new .android.rel.dyn or .android.rela.dyn section. Packing reduces +the footprint of libchrome.<version>.so in the filesystem, in APK downloads, +and in memory when loaded on the device. + +A packed libchrome.<version>.so is designed so that it can be loaded directly +on Android, but requires the explicit support of a crazy linker that has been +extended to understand packed relocations. Packed relocations are currently +only supported on ARM. + +A packed libchrome.<version>.so cannot currently be used with the standard +Android runtime linker. + +See src/*.h for design and implementation notes. + + +Notes: +------ + +Packing does not adjust debug data. An unstripped libchrome.<version>.so +can be packed and will run, but may no longer be useful for debugging. + +Unpacking on the device requires the explicit support of an extended crazy +linker. Adds the following new .dynamic tags, used by the crazy linker to +find the packed .android.rel.dyn or .android.rela.dyn section data: + + DT_ANDROID_REL_OFFSET = DT_LOOS (Operating System specific: 0x6000000d) + - The offset of packed relocation data in libchrome.<version>.so + DT_ANDROID_REL_SIZE = DT_LOOS + 1 (Operating System Specific: 0x6000000e) + - The size of packed relocation data in bytes + +32 bit ARM libraries use relocations without addends. 64 bit ARM libraries +use relocations with addends. The packing strategy necessarily differs for +the two relocation types. + +Where libchrome.<version>.so contains relocations without addends, the format +of .android.rel.dyn data is: + + "APR1" identifier + N: the number of count-delta pairs in the encoding + A: the initial offset + N * C,D: N count-delta pairs + +Where libchrome.<version>.so contains relocations with addends, the format +of .android.rela.dyn data is: + + "APA1" identifier + N: the number of addr-addend delta pairs in the encoding + N * A,V: N addr-addend delta pairs + +All numbers in the encoding stream are stored as LEB128 values. For details +see http://en.wikipedia.org/wiki/LEB128. + +The streaming unpacking algorithm for 32 bit ARM is: + + skip over "APR1" + pairs, addr = next leb128 value, next leb128 value + emit R_ARM_RELATIVE relocation with r_offset = addr + while pairs: + count, delta = next leb128 value, next leb128 value + while count: + addr += delta + emit R_ARM_RELATIVE relocation with r_offset = addr + count-- + pairs-- + +The streaming unpacking algorithm for 64 bit ARM is: + + skip over "APA1" + pairs = next signed leb128 value + addr, addend = 0, 0 + while pairs: + addr += next signed leb128 value + addend += next signed leb128 value + emit R_AARCH64_RELATIVE relocation with r_offset = addr, r_addend = addend + pairs-- + + +Usage instructions: +------------------- + +To pack relocations, add an empty .android.rel.dyn or .android.rela.dyn and +then run the tool: + + echo -n 'NULL' >/tmp/small + if file libchrome.<version>.so | grep -q 'ELF 32'; then + arm-linux-androideabi-objcopy + --add-section .android.rel.dyn=/tmp/small + libchrome.<version>.so libchrome.<version>.so.packed + else + aarch64-linux-android-objcopy + --add-section .android.rela.dyn=/tmp/small + libchrome.<version>.so libchrome.<version>.so.packed + fi + rm /tmp/small + relocation_packer libchrome.<version>.so.packed + +To unpack and restore the shared library to its original state: + + cp libchrome.<version>.so.packed unpackable + relocation_packer -u unpackable + if file libchrome.<version>.so | grep -q 'ELF 32'; then + arm-linux-androideabi-objcopy \ + --remove-section=.android.rel.dyn unpackable libchrome.<version>.so + else + aarch64-linux-android-objcopy \ + --remove-section=.android.rela.dyn unpackable libchrome.<version>.so + endif + rm unpackable + + +Bugs & TODOs: +------------- + +Requires two free slots in the .dynamic section. Uses these to add data that +tells the crazy linker where to find the packed relocation data. Fails +if insufficient free slots exist (use gold --spare-dynamic-slots to increase +the allocation). + +Requires libelf 0.158 or later. Earlier libelf releases may be buggy in +ways that prevent the packer from working correctly. + + +Testing: +-------- + +Unittests run under gtest, on the host system. diff --git a/tools/relocation_packer/config.gni b/tools/relocation_packer/config.gni new file mode 100644 index 0000000..90e3979 --- /dev/null +++ b/tools/relocation_packer/config.gni @@ -0,0 +1,21 @@ +# Copyright 2014 The Chromium Authors. All rights reserved. +# Use of this source code is governed by a BSD-style license that can be +# found in the LICENSE file. + +relocation_packing_supported = target_arch == "arm" || target_arch == "arm64" + +if (relocation_packing_supported) { + relocation_packer_target = "//tools/relocation_packer($host_toolchain)" + relocation_packer_dir = + get_label_info("$relocation_packer_target", "root_out_dir") + relocation_packer_exe = "${relocation_packer_dir}/relocation_packer" + + if (target_arch == "arm") { + relocations_have_addends = 0 + } else if (target_arch == "arm64") { + relocations_have_addends = 1 + } +} else { + relocations_have_addends = 0 + relocation_packer_exe = "" +} diff --git a/tools/relocation_packer/relocation_packer.gyp b/tools/relocation_packer/relocation_packer.gyp new file mode 100644 index 0000000..1e9c1b9 --- /dev/null +++ b/tools/relocation_packer/relocation_packer.gyp @@ -0,0 +1,161 @@ +# Copyright 2014 The Chromium Authors. All rights reserved. +# Use of this source code is governed by a BSD-style license that can be +# found in the LICENSE file. + +{ + 'variables': { + 'target_define%': 'TARGET_UNSUPPORTED', + 'conditions': [ + [ 'target_arch == "arm"', { + 'target_define': 'TARGET_ARM', + }], + [ 'target_arch == "arm64"', { + 'target_define': 'TARGET_ARM64', + }], + ], + }, + 'targets': [ + { + # GN: //tools/relocation_packer:lib_relocation_packer + 'target_name': 'lib_relocation_packer', + 'toolsets': ['host'], + 'type': 'static_library', + 'defines': [ + '<(target_define)', + ], + 'dependencies': [ + '../../third_party/elfutils/elfutils.gyp:libelf', + ], + 'sources': [ + 'src/debug.cc', + 'src/delta_encoder.cc', + 'src/elf_file.cc', + 'src/leb128.cc', + 'src/packer.cc', + 'src/sleb128.cc', + 'src/run_length_encoder.cc', + ], + }, + { + # GN: //tools/relocation_packer:relocation_packer + 'target_name': 'relocation_packer', + 'toolsets': ['host'], + 'type': 'executable', + 'defines': [ + '<(target_define)', + ], + 'dependencies': [ + '../../third_party/elfutils/elfutils.gyp:libelf', + 'lib_relocation_packer', + ], + 'sources': [ + 'src/main.cc', + ], + }, + { + # GN: //tools/relocation_packer:relocation_packer_unittests + 'target_name': 'relocation_packer_unittests', + 'toolsets': ['host'], + 'type': 'executable', + 'defines': [ + '<(target_define)', + ], + 'cflags': [ + '-DINTERMEDIATE_DIR="<(INTERMEDIATE_DIR)"', + ], + 'dependencies': [ + '../../testing/gtest.gyp:gtest', + 'lib_relocation_packer', + ], + 'include_dirs': [ + '../..', + ], + 'sources': [ + 'src/debug_unittest.cc', + 'src/delta_encoder_unittest.cc', + 'src/elf_file_unittest.cc', + 'src/leb128_unittest.cc', + 'src/packer_unittest.cc', + 'src/sleb128_unittest.cc', + 'src/run_length_encoder_unittest.cc', + 'src/run_all_unittests.cc', + ], + 'copies': [ + { + 'destination': '<(INTERMEDIATE_DIR)', + 'files': [ + 'test_data/elf_file_unittest_relocs_arm32.so', + 'test_data/elf_file_unittest_relocs_arm32_packed.so', + 'test_data/elf_file_unittest_relocs_arm64.so', + 'test_data/elf_file_unittest_relocs_arm64_packed.so', + ], + }, + ], + }, + + # Targets to build test data. These participate only in building test + # data for use with elf_file_unittest.cc, and are not part of the main + # relocation packer build. Unit test data files are checked in to the + # source tree as 'golden' data, and are not generated 'on the fly' by + # the build. + # + # See test_data/generate_elf_file_unittest_relocs.sh for instructions. + { + # GN: //tools/relocation_packer:relocation_packer_test_data + 'target_name': 'relocation_packer_test_data', + 'toolsets': ['target'], + 'type': 'shared_library', + 'cflags': [ + '-O0', + '-g0', + ], + 'sources': [ + 'test_data/elf_file_unittest_relocs.cc', + ], + }, + { + # GN: //tools/relocation_packer:relocation_packer_unittests_test_data + 'target_name': 'relocation_packer_unittests_test_data', + 'toolsets': ['target'], + 'type': 'none', + 'actions': [ + { + 'variables': { + 'test_file': '<(SHARED_LIB_DIR)/librelocation_packer_test_data.so', + 'conditions': [ + [ 'target_arch == "arm"', { + 'added_section': '.android.rel.dyn', + 'unpacked_output': 'elf_file_unittest_relocs_arm32.so', + 'packed_output': 'elf_file_unittest_relocs_arm32_packed.so', + }], + [ 'target_arch == "arm64"', { + 'added_section': '.android.rela.dyn', + 'unpacked_output': 'elf_file_unittest_relocs_arm64.so', + 'packed_output': 'elf_file_unittest_relocs_arm64_packed.so', + }], + ], + }, + 'action_name': 'generate_relocation_packer_test_data', + 'inputs': [ + 'test_data/generate_elf_file_unittest_relocs.py', + '<(PRODUCT_DIR)/relocation_packer', + '<(test_file)', + ], + 'outputs': [ + '<(INTERMEDIATE_DIR)/<(unpacked_output)', + '<(INTERMEDIATE_DIR)/<(packed_output)', + ], + 'action': [ + 'python', 'test_data/generate_elf_file_unittest_relocs.py', + '--android-pack-relocations=<(PRODUCT_DIR)/relocation_packer', + '--android-objcopy=<(android_objcopy)', + '--added-section=<(added_section)', + '--test-file=<(test_file)', + '--unpacked-output=<(INTERMEDIATE_DIR)/<(unpacked_output)', + '--packed-output=<(INTERMEDIATE_DIR)/<(packed_output)', + ], + }, + ], + }, + ], +} diff --git a/tools/relocation_packer/src/debug.cc b/tools/relocation_packer/src/debug.cc new file mode 100644 index 0000000..29d7ab0 --- /dev/null +++ b/tools/relocation_packer/src/debug.cc @@ -0,0 +1,55 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "debug.h" + +#include <stdlib.h> +#include <iostream> +#include <string> + +namespace relocation_packer { + +// Construct a new message logger. Prints if level is less than or equal to +// the level set with SetVerbose() and predicate is true. +Logger::Logger(Severity severity, int level, bool predicate) { + severity_ = severity; + level_ = level; + predicate_ = predicate; +} + +// On destruction, flush and print the strings accumulated. Abort if FATAL. +Logger::~Logger() { + if (predicate_) { + if (level_ <= max_level_) { + std::ostream* log = severity_ == INFO ? info_stream_ : error_stream_; + std::string tag; + switch (severity_) { + case INFO: tag = "INFO"; break; + case WARNING: tag = "WARNING"; break; + case ERROR: tag = "ERROR"; break; + case FATAL: tag = "FATAL"; break; + } + stream_.flush(); + *log << tag << ": " << stream_.str() << std::endl; + } + if (severity_ == FATAL) + abort(); + } +} + +// Reset to initial state. +void Logger::Reset() { + max_level_ = -1; + info_stream_ = &std::cout; + error_stream_ = &std::cerr; +} + +// Verbosity. Not thread-safe. +int Logger::max_level_ = -1; + +// Logging streams. Not thread-safe. +std::ostream* Logger::info_stream_ = &std::cout; +std::ostream* Logger::error_stream_ = &std::cerr; + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/debug.h b/tools/relocation_packer/src/debug.h new file mode 100644 index 0000000..48be6c1 --- /dev/null +++ b/tools/relocation_packer/src/debug.h @@ -0,0 +1,115 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Logging and checks. Avoids a dependency on base. +// +// LOG(tag) prints messages. Tags are INFO, WARNING, ERROR and FATAL. +// INFO prints to stdout, the others to stderr. FATAL aborts after printing. +// +// LOG_IF(tag, predicate) logs if predicate evaluates to true, else silent. +// +// VLOG(level) logs INFO messages where level is less than or equal to the +// verbosity level set with SetVerbose(). +// +// VLOG_IF(level, predicate) logs INFO if predicate evaluates to true, +// else silent. +// +// CHECK(predicate) logs a FATAL error if predicate is false. +// NOTREACHED() always aborts. +// Log streams can be changed with SetStreams(). Logging is not thread-safe. +// + +#ifndef TOOLS_RELOCATION_PACKER_SRC_DEBUG_H_ +#define TOOLS_RELOCATION_PACKER_SRC_DEBUG_H_ + +#include <limits.h> +#include <ostream> +#include <sstream> + +namespace relocation_packer { + +class Logger { + public: + enum Severity {INFO = 0, WARNING, ERROR, FATAL}; + + // Construct a new message logger. Prints if level is less than or + // equal to the level set with SetVerbose() and predicate is true. + // |severity| is an enumerated severity. + // |level| is the verbosity level. + // |predicate| controls if the logger prints or is silent. + Logger(Severity severity, int level, bool predicate); + + // On destruction, flush and print the strings accumulated in stream_. + ~Logger(); + + // Return the stream for this logger. + std::ostream& GetStream() { return stream_; } + + // Set verbosity level. Messages with a level less than or equal to + // this level are printed, others are discarded. Static, not thread-safe. + static void SetVerbose(int level) { max_level_ = level; } + + // Set info and error logging streams. Static, not thread-safe. + static void SetStreams(std::ostream* info_stream, + std::ostream* error_stream) { + info_stream_ = info_stream; + error_stream_ = error_stream; + } + + // Reset to initial state. + static void Reset(); + + private: + // Message severity, verbosity level, and predicate. + Severity severity_; + int level_; + bool predicate_; + + // String stream, accumulates message text. + std::ostringstream stream_; + + // Verbosity for INFO messages. Not thread-safe. + static int max_level_; + + // Logging streams. Not thread-safe. + static std::ostream* info_stream_; + static std::ostream* error_stream_; +}; + +} // namespace relocation_packer + +// Make logging severities visible globally. +typedef relocation_packer::Logger::Severity LogSeverity; +using LogSeverity::INFO; +using LogSeverity::WARNING; +using LogSeverity::ERROR; +using LogSeverity::FATAL; + +// LOG(severity) prints a message with the given severity, and aborts if +// severity is FATAL. LOG_IF(severity, predicate) does the same but only if +// predicate is true. INT_MIN is guaranteed to be less than or equal to +// any verbosity level. +#define LOG(severity) \ + (relocation_packer::Logger(severity, INT_MIN, true).GetStream()) +#define LOG_IF(severity, predicate) \ + (relocation_packer::Logger(severity, INT_MIN, (predicate)).GetStream()) + +// VLOG(level) prints its message as INFO if level is less than or equal to +// the current verbosity level. +#define VLOG(level) \ + (relocation_packer::Logger(INFO, (level), true).GetStream()) +#define VLOG_IF(level, predicate) \ + (relocation_packer::Logger(INFO, (level), (predicate)).GetStream()) + +// CHECK(predicate) fails with a FATAL log message if predicate is false. +#define CHECK(predicate) (LOG_IF(FATAL, !(predicate)) \ + << __FILE__ << ":" << __LINE__ << ": " \ + << __FUNCTION__ << ": CHECK '" #predicate "' failed") + +// NOTREACHED() always fails with a FATAL log message. +#define NOTREACHED(_) (LOG(FATAL) \ + << __FILE__ << ":" << __LINE__ << ": " \ + << __FUNCTION__ << ": NOTREACHED() hit") + +#endif // TOOLS_RELOCATION_PACKER_SRC_DEBUG_H_ diff --git a/tools/relocation_packer/src/debug_unittest.cc b/tools/relocation_packer/src/debug_unittest.cc new file mode 100644 index 0000000..1b65cd1 --- /dev/null +++ b/tools/relocation_packer/src/debug_unittest.cc @@ -0,0 +1,122 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "debug.h" + +#include <sstream> +#include "testing/gtest/include/gtest/gtest.h" + +namespace relocation_packer { + +TEST(Debug, Log) { + Logger::Reset(); + std::ostringstream info; + std::ostringstream error; + Logger::SetStreams(&info, &error); + + LOG(INFO) << "INFO log message"; + LOG(WARNING) << "WARNING log message"; + LOG(ERROR) << "ERROR log message"; + + EXPECT_EQ("INFO: INFO log message\n", info.str()); + EXPECT_EQ("WARNING: WARNING log message\n" + "ERROR: ERROR log message\n", error.str()); + Logger::Reset(); +} + +TEST(Debug, LogIf) { + Logger::Reset(); + std::ostringstream info; + std::ostringstream error; + Logger::SetStreams(&info, &error); + + LOG_IF(INFO, true) << "INFO log message"; + LOG_IF(INFO, false) << "INFO log message, SHOULD NOT PRINT"; + LOG_IF(WARNING, true) << "WARNING log message"; + LOG_IF(WARNING, false) << "WARNING log message, SHOULD NOT PRINT"; + LOG_IF(ERROR, true) << "ERROR log message"; + LOG_IF(ERROR, false) << "ERROR log message, SHOULD NOT PRINT"; + LOG_IF(FATAL, false) << "FATAL log message, SHOULD NOT PRINT"; + + EXPECT_EQ("INFO: INFO log message\n", info.str()); + EXPECT_EQ("WARNING: WARNING log message\n" + "ERROR: ERROR log message\n", error.str()); + Logger::Reset(); +} + +TEST(Debug, Vlog) { + Logger::Reset(); + std::ostringstream info; + std::ostringstream error; + Logger::SetStreams(&info, &error); + + VLOG(0) << "VLOG 0 INFO log message, SHOULD NOT PRINT"; + VLOG(1) << "VLOG 1 INFO log message, SHOULD NOT PRINT"; + VLOG(2) << "VLOG 2 INFO log message, SHOULD NOT PRINT"; + + EXPECT_EQ("", info.str()); + EXPECT_EQ("", error.str()); + + Logger::SetVerbose(1); + + VLOG(0) << "VLOG 0 INFO log message"; + VLOG(1) << "VLOG 1 INFO log message"; + VLOG(2) << "VLOG 2 INFO log message, SHOULD NOT PRINT"; + + EXPECT_EQ("INFO: VLOG 0 INFO log message\n" + "INFO: VLOG 1 INFO log message\n", info.str()); + EXPECT_EQ("", error.str()); + Logger::Reset(); +} + +TEST(Debug, VlogIf) { + Logger::Reset(); + std::ostringstream info; + std::ostringstream error; + Logger::SetStreams(&info, &error); + + VLOG_IF(0, true) << "VLOG 0 INFO log message, SHOULD NOT PRINT"; + VLOG_IF(1, true) << "VLOG 1 INFO log message, SHOULD NOT PRINT"; + VLOG_IF(2, true) << "VLOG 2 INFO log message, SHOULD NOT PRINT"; + + EXPECT_EQ("", info.str()); + EXPECT_EQ("", error.str()); + + Logger::SetVerbose(1); + + VLOG_IF(0, true) << "VLOG 0 INFO log message"; + VLOG_IF(0, false) << "VLOG 0 INFO log message, SHOULD NOT PRINT"; + VLOG_IF(1, true) << "VLOG 1 INFO log message"; + VLOG_IF(1, false) << "VLOG 1 INFO log message, SHOULD NOT PRINT"; + VLOG_IF(2, true) << "VLOG 2 INFO log message, SHOULD NOT PRINT"; + VLOG_IF(2, false) << "VLOG 2 INFO log message, SHOULD NOT PRINT"; + + EXPECT_EQ("INFO: VLOG 0 INFO log message\n" + "INFO: VLOG 1 INFO log message\n", info.str()); + EXPECT_EQ("", error.str()); + Logger::Reset(); +} + +TEST(DebugDeathTest, Fatal) { + ::testing::FLAGS_gtest_death_test_style = "threadsafe"; + Logger::Reset(); + EXPECT_DEATH(LOG(FATAL) << "FATAL log message", "FATAL: FATAL log message"); + EXPECT_DEATH( + LOG_IF(FATAL, true) << "FATAL log message", "FATAL: FATAL log message"); +} + +TEST(DebugDeathTest, Check) { + ::testing::FLAGS_gtest_death_test_style = "threadsafe"; + Logger::Reset(); + CHECK(0 == 0); + EXPECT_DEATH(CHECK(0 == 1), "FATAL: .*:.*: .*: CHECK '0 == 1' failed"); +} + +TEST(DebugDeathTest, NotReached) { + ::testing::FLAGS_gtest_death_test_style = "threadsafe"; + Logger::Reset(); + EXPECT_DEATH(NOTREACHED(), "FATAL: .*:.*: .*: NOTREACHED\\(\\) hit"); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/delta_encoder.cc b/tools/relocation_packer/src/delta_encoder.cc new file mode 100644 index 0000000..69cc91a --- /dev/null +++ b/tools/relocation_packer/src/delta_encoder.cc @@ -0,0 +1,72 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "delta_encoder.h" + +#include <vector> + +#include "debug.h" +#include "elf_traits.h" + +namespace relocation_packer { + +// Encode relative relocations with addends into a delta encoded (packed) +// representation. Represented as simple r_offset and r_addend delta pairs, +// with an implicit neutral element at the start. +void RelocationDeltaCodec::Encode(const std::vector<ELF::Rela>& relocations, + std::vector<ELF::Sxword>* packed) { + // One relocation is sufficient for delta encoding. + if (relocations.size() < 1) + return; + + // Start with the element count, then append the delta pairs. + packed->push_back(relocations.size()); + + ELF::Addr offset = 0; + ELF::Sxword addend = 0; + + for (size_t i = 0; i < relocations.size(); ++i) { + const ELF::Rela* relocation = &relocations[i]; + CHECK(ELF_R_TYPE(relocation->r_info) == ELF::kRelativeRelocationCode); + + packed->push_back(relocation->r_offset - offset); + offset = relocation->r_offset; + packed->push_back(relocation->r_addend - addend); + addend = relocation->r_addend; + } +} + +// Decode relative relocations with addends from a delta encoded (packed) +// representation. +void RelocationDeltaCodec::Decode(const std::vector<ELF::Sxword>& packed, + std::vector<ELF::Rela>* relocations) { + // We need at least one packed pair after the packed pair count to be + // able to unpack. + if (packed.size() < 3) + return; + + // Ensure that the packed data offers enough pairs. There may be zero + // padding on it that we ignore. + CHECK(static_cast<size_t>(packed[0]) <= (packed.size() - 1) >> 1); + + ELF::Addr offset = 0; + ELF::Sxword addend = 0; + + // The first packed vector element is the pairs count. Start uncondensing + // pairs at the second, and finish at the end of the pairs data. + const size_t pairs_count = packed[0]; + for (size_t i = 1; i < 1 + (pairs_count << 1); i += 2) { + offset += packed[i]; + addend += packed[i + 1]; + + // Generate a relocation for this offset and addend pair. + ELF::Rela relocation; + relocation.r_offset = offset; + relocation.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode); + relocation.r_addend = addend; + relocations->push_back(relocation); + } +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/delta_encoder.h b/tools/relocation_packer/src/delta_encoder.h new file mode 100644 index 0000000..498b6d1 --- /dev/null +++ b/tools/relocation_packer/src/delta_encoder.h @@ -0,0 +1,80 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Delta encode and decode relative relocations with addends. +// +// Relative relocations are the bulk of dynamic relocations (the +// .rel.dyn or .rela.dyn sections) in libchrome.<version>.so, and the ELF +// standard representation of them is wasteful. .rel.dyn contains +// relocations without addends, .rela.dyn relocations with addends. +// +// A relocation with an addend is 12 bytes on 32 bit platforms and 24 bytes +// on 64 bit plaforms. It is split into offset, info, and addend fields. +// Offsets strictly increase, and each is commonly a few bytes different +// from its predecessor. Addends are less well behaved. The info field is +// constant. Example, from 'readelf -x4 libchrome.<version>.so' 64 bit: +// +// offset info +// 80949303 00000000 03040000 00000000 ................ +// addend offset +// fc015b00 00000000 88949303 00000000 ..[............. +// info addend +// 03040000 00000000 24025b00 00000000 ........$.[..... +// offset info +// 90949303 00000000 03040000 00000000 ................ +// addend offset +// 3c025b00 00000000 98949303 00000000 <.[............. +// info addend +// 03040000 00000000 50025b00 00000000 ........P.[..... +// +// The offset strictly increases, but the addend is unpredictable, so run +// length encoding will not work well with this data. We can however pack +// with delta encoding. The upper four bytes of the eight byte offset and +// addend are invariably zeroes. The difference between adjacent offsets +// is almost always small, and between adjacent addends is often small. And +// info is constant and can be eliminated. +// +// Delta encoding reduces the size of the data modestly, so that the first +// three relocations above can be represented as: +// +// initial offset initial addend offset delta addend delta +// 00000000 03939480 00000000 005b01fc 00000000 00000008 00000000 00000028 +// offset delta addend delta ... +// 00000000 00000008 00000000 0000009f +// +// The addend delta can be negative as well as positive, but overall the +// deltas have a much smaller range than the input data. When encoded as +// signed LEB128 the total data reduction becomes useful. + +#ifndef TOOLS_RELOCATION_PACKER_SRC_DELTA_ENCODER_H_ +#define TOOLS_RELOCATION_PACKER_SRC_DELTA_ENCODER_H_ + +#include <vector> + +#include "elf.h" +#include "elf_traits.h" + +namespace relocation_packer { + +// A RelocationDeltaCodec packs vectors of relative relocations with +// addends into more compact forms, and unpacks them to reproduce the +// pre-packed data. +class RelocationDeltaCodec { + public: + // Encode relative relocations with addends into a more compact form. + // |relocations| is a vector of relative relocation with addend structs. + // |packed| is the vector of packed words into which relocations are packed. + static void Encode(const std::vector<ELF::Rela>& relocations, + std::vector<ELF::Sxword>* packed); + + // Decode relative relocations with addends from their more compact form. + // |packed| is the vector of packed relocations. + // |relocations| is a vector of unpacked relative relocations. + static void Decode(const std::vector<ELF::Sxword>& packed, + std::vector<ELF::Rela>* relocations); +}; + +} // namespace relocation_packer + +#endif // TOOLS_RELOCATION_PACKER_SRC_DELTA_ENCODER_H_ diff --git a/tools/relocation_packer/src/delta_encoder_unittest.cc b/tools/relocation_packer/src/delta_encoder_unittest.cc new file mode 100644 index 0000000..b9bf39a --- /dev/null +++ b/tools/relocation_packer/src/delta_encoder_unittest.cc @@ -0,0 +1,150 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "delta_encoder.h" + +#include <vector> +#include "elf.h" +#include "elf_traits.h" +#include "testing/gtest/include/gtest/gtest.h" + +namespace { + +void AddRelocation(ELF::Addr addr, + ELF::Sxword addend, + std::vector<ELF::Rela>* relocations) { + ELF::Rela relocation; + relocation.r_offset = addr; + relocation.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode); + relocation.r_addend = addend; + relocations->push_back(relocation); +} + +bool CheckRelocation(ELF::Addr addr, + ELF::Sxword addend, + const ELF::Rela& relocation) { + return relocation.r_offset == addr && + ELF_R_SYM(relocation.r_info) == 0 && + ELF_R_TYPE(relocation.r_info) == ELF::kRelativeRelocationCode && + relocation.r_addend == addend; +} + +} // namespace + +namespace relocation_packer { + +TEST(Delta, Encode) { + std::vector<ELF::Rela> relocations; + std::vector<ELF::Sxword> packed; + + RelocationDeltaCodec codec; + + packed.clear(); + codec.Encode(relocations, &packed); + + EXPECT_EQ(0, packed.size()); + + // Initial relocation. + AddRelocation(0xf00d0000, 10000, &relocations); + + packed.clear(); + codec.Encode(relocations, &packed); + + EXPECT_EQ(3, packed.size()); + // One pair present. + EXPECT_EQ(1, packed[0]); + // Delta from the neutral element is the initial relocation. + EXPECT_EQ(0xf00d0000, packed[1]); + EXPECT_EQ(10000, packed[2]); + + // Add a second relocation, 4 byte offset delta, 12 byte addend delta. + AddRelocation(0xf00d0004, 10012, &relocations); + + packed.clear(); + codec.Encode(relocations, &packed); + + EXPECT_EQ(5, packed.size()); + // Two pairs present. + EXPECT_EQ(2, packed[0]); + // Delta from the neutral element is the initial relocation. + EXPECT_EQ(0xf00d0000, packed[1]); + EXPECT_EQ(10000, packed[2]); + // 4 byte offset delta, 12 byte addend delta. + EXPECT_EQ(4, packed[3]); + EXPECT_EQ(12, packed[4]); + + // Add a third relocation, 4 byte offset delta, 12 byte addend delta. + AddRelocation(0xf00d0008, 10024, &relocations); + + // Add three more relocations, 8 byte offset deltas, -24 byte addend deltas. + AddRelocation(0xf00d0010, 10000, &relocations); + AddRelocation(0xf00d0018, 9976, &relocations); + AddRelocation(0xf00d0020, 9952, &relocations); + + packed.clear(); + codec.Encode(relocations, &packed); + + EXPECT_EQ(13, packed.size()); + // Six pairs present. + EXPECT_EQ(6, packed[0]); + // Initial relocation. + EXPECT_EQ(0xf00d0000, packed[1]); + EXPECT_EQ(10000, packed[2]); + // Two relocations, 4 byte offset deltas, 12 byte addend deltas. + EXPECT_EQ(4, packed[3]); + EXPECT_EQ(12, packed[4]); + EXPECT_EQ(4, packed[5]); + EXPECT_EQ(12, packed[6]); + // Three relocations, 8 byte offset deltas, -24 byte addend deltas. + EXPECT_EQ(8, packed[7]); + EXPECT_EQ(-24, packed[8]); + EXPECT_EQ(8, packed[9]); + EXPECT_EQ(-24, packed[10]); + EXPECT_EQ(8, packed[11]); + EXPECT_EQ(-24, packed[12]); +} + +TEST(Delta, Decode) { + std::vector<ELF::Sxword> packed; + std::vector<ELF::Rela> relocations; + + RelocationDeltaCodec codec; + codec.Decode(packed, &relocations); + + EXPECT_EQ(0, relocations.size()); + + // Six pairs. + packed.push_back(6); + // Initial relocation. + packed.push_back(0xc0de0000); + packed.push_back(10000); + // Two relocations, 4 byte offset deltas, 12 byte addend deltas. + packed.push_back(4); + packed.push_back(12); + packed.push_back(4); + packed.push_back(12); + // Three relocations, 8 byte offset deltas, -24 byte addend deltas. + packed.push_back(8); + packed.push_back(-24); + packed.push_back(8); + packed.push_back(-24); + packed.push_back(8); + packed.push_back(-24); + + relocations.clear(); + codec.Decode(packed, &relocations); + + EXPECT_EQ(6, relocations.size()); + // Initial relocation. + EXPECT_TRUE(CheckRelocation(0xc0de0000, 10000, relocations[0])); + // Two relocations, 4 byte offset deltas, 12 byte addend deltas. + EXPECT_TRUE(CheckRelocation(0xc0de0004, 10012, relocations[1])); + EXPECT_TRUE(CheckRelocation(0xc0de0008, 10024, relocations[2])); + // Three relocations, 8 byte offset deltas, -24 byte addend deltas. + EXPECT_TRUE(CheckRelocation(0xc0de0010, 10000, relocations[3])); + EXPECT_TRUE(CheckRelocation(0xc0de0018, 9976, relocations[4])); + EXPECT_TRUE(CheckRelocation(0xc0de0020, 9952, relocations[5])); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/elf_file.cc b/tools/relocation_packer/src/elf_file.cc new file mode 100644 index 0000000..3ffccec --- /dev/null +++ b/tools/relocation_packer/src/elf_file.cc @@ -0,0 +1,1283 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Implementation notes: +// +// We need to remove a piece from the ELF shared library. However, we also +// want to ensure that code and data loads at the same addresses as before +// packing, so that tools like breakpad can still match up addresses found +// in any crash dumps with data extracted from the pre-packed version of +// the shared library. +// +// Arranging this means that we have to split one of the LOAD segments into +// two. Unfortunately, the program headers are located at the very start +// of the shared library file, so expanding the program header section +// would cause a lot of consequent changes to files offsets that we don't +// really want to have to handle. +// +// Luckily, though, there is a segment that is always present and always +// unused on Android; the GNU_STACK segment. What we do is to steal that +// and repurpose it to be one of the split LOAD segments. We then have to +// sort LOAD segments by offset to keep the crazy linker happy. +// +// All of this takes place in SplitProgramHeadersForHole(), used on packing, +// and is unraveled on unpacking in CoalesceProgramHeadersForHole(). See +// commentary on those functions for an example of this segment stealing +// in action. + +#include "elf_file.h" + +#include <stdlib.h> +#include <sys/types.h> +#include <unistd.h> +#include <algorithm> +#include <string> +#include <vector> + +#include "debug.h" +#include "elf_traits.h" +#include "libelf.h" +#include "packer.h" + +namespace relocation_packer { + +// Stub identifier written to 'null out' packed data, "NULL". +static const uint32_t kStubIdentifier = 0x4c4c554eu; + +// Out-of-band dynamic tags used to indicate the offset and size of the +// android packed relocations section. +static const ELF::Sword DT_ANDROID_REL_OFFSET = DT_LOOS; +static const ELF::Sword DT_ANDROID_REL_SIZE = DT_LOOS + 1; + +// Alignment to preserve, in bytes. This must be at least as large as the +// largest d_align and sh_addralign values found in the loaded file. +// Out of caution for RELRO page alignment, we preserve to a complete target +// page. See http://www.airs.com/blog/archives/189. +static const size_t kPreserveAlignment = 4096; + +namespace { + +// Get section data. Checks that the section has exactly one data entry, +// so that the section size and the data size are the same. True in +// practice for all sections we resize when packing or unpacking. Done +// by ensuring that a call to elf_getdata(section, data) returns NULL as +// the next data entry. +Elf_Data* GetSectionData(Elf_Scn* section) { + Elf_Data* data = elf_getdata(section, NULL); + CHECK(data && elf_getdata(section, data) == NULL); + return data; +} + +// Rewrite section data. Allocates new data and makes it the data element's +// buffer. Relies on program exit to free allocated data. +void RewriteSectionData(Elf_Scn* section, + const void* section_data, + size_t size) { + Elf_Data* data = GetSectionData(section); + CHECK(size == data->d_size); + uint8_t* area = new uint8_t[size]; + memcpy(area, section_data, size); + data->d_buf = area; +} + +// Verbose ELF header logging. +void VerboseLogElfHeader(const ELF::Ehdr* elf_header) { + VLOG(1) << "e_phoff = " << elf_header->e_phoff; + VLOG(1) << "e_shoff = " << elf_header->e_shoff; + VLOG(1) << "e_ehsize = " << elf_header->e_ehsize; + VLOG(1) << "e_phentsize = " << elf_header->e_phentsize; + VLOG(1) << "e_phnum = " << elf_header->e_phnum; + VLOG(1) << "e_shnum = " << elf_header->e_shnum; + VLOG(1) << "e_shstrndx = " << elf_header->e_shstrndx; +} + +// Verbose ELF program header logging. +void VerboseLogProgramHeader(size_t program_header_index, + const ELF::Phdr* program_header) { + std::string type; + switch (program_header->p_type) { + case PT_NULL: type = "NULL"; break; + case PT_LOAD: type = "LOAD"; break; + case PT_DYNAMIC: type = "DYNAMIC"; break; + case PT_INTERP: type = "INTERP"; break; + case PT_PHDR: type = "PHDR"; break; + case PT_GNU_RELRO: type = "GNU_RELRO"; break; + case PT_GNU_STACK: type = "GNU_STACK"; break; + case PT_ARM_EXIDX: type = "EXIDX"; break; + default: type = "(OTHER)"; break; + } + VLOG(1) << "phdr[" << program_header_index << "] : " << type; + VLOG(1) << " p_offset = " << program_header->p_offset; + VLOG(1) << " p_vaddr = " << program_header->p_vaddr; + VLOG(1) << " p_paddr = " << program_header->p_paddr; + VLOG(1) << " p_filesz = " << program_header->p_filesz; + VLOG(1) << " p_memsz = " << program_header->p_memsz; + VLOG(1) << " p_flags = " << program_header->p_flags; + VLOG(1) << " p_align = " << program_header->p_align; +} + +// Verbose ELF section header logging. +void VerboseLogSectionHeader(const std::string& section_name, + const ELF::Shdr* section_header) { + VLOG(1) << "section " << section_name; + VLOG(1) << " sh_addr = " << section_header->sh_addr; + VLOG(1) << " sh_offset = " << section_header->sh_offset; + VLOG(1) << " sh_size = " << section_header->sh_size; + VLOG(1) << " sh_addralign = " << section_header->sh_addralign; +} + +// Verbose ELF section data logging. +void VerboseLogSectionData(const Elf_Data* data) { + VLOG(1) << " data"; + VLOG(1) << " d_buf = " << data->d_buf; + VLOG(1) << " d_off = " << data->d_off; + VLOG(1) << " d_size = " << data->d_size; + VLOG(1) << " d_align = " << data->d_align; +} + +} // namespace + +// Load the complete ELF file into a memory image in libelf, and identify +// the .rel.dyn or .rela.dyn, .dynamic, and .android.rel.dyn or +// .android.rela.dyn sections. No-op if the ELF file has already been loaded. +bool ElfFile::Load() { + if (elf_) + return true; + + Elf* elf = elf_begin(fd_, ELF_C_RDWR, NULL); + CHECK(elf); + + if (elf_kind(elf) != ELF_K_ELF) { + LOG(ERROR) << "File not in ELF format"; + return false; + } + + ELF::Ehdr* elf_header = ELF::getehdr(elf); + if (!elf_header) { + LOG(ERROR) << "Failed to load ELF header: " << elf_errmsg(elf_errno()); + return false; + } + if (elf_header->e_machine != ELF::kMachine) { + LOG(ERROR) << "ELF file architecture is not " << ELF::Machine(); + return false; + } + if (elf_header->e_type != ET_DYN) { + LOG(ERROR) << "ELF file is not a shared object"; + return false; + } + + // Require that our endianness matches that of the target, and that both + // are little-endian. Safe for all current build/target combinations. + const int endian = elf_header->e_ident[EI_DATA]; + CHECK(endian == ELFDATA2LSB); + CHECK(__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__); + + // Also require that the file class is as expected. + const int file_class = elf_header->e_ident[EI_CLASS]; + CHECK(file_class == ELF::kFileClass); + + VLOG(1) << "endian = " << endian << ", file class = " << file_class; + VerboseLogElfHeader(elf_header); + + const ELF::Phdr* elf_program_header = ELF::getphdr(elf); + CHECK(elf_program_header); + + const ELF::Phdr* dynamic_program_header = NULL; + for (size_t i = 0; i < elf_header->e_phnum; ++i) { + const ELF::Phdr* program_header = &elf_program_header[i]; + VerboseLogProgramHeader(i, program_header); + + if (program_header->p_type == PT_DYNAMIC) { + CHECK(dynamic_program_header == NULL); + dynamic_program_header = program_header; + } + } + CHECK(dynamic_program_header != NULL); + + size_t string_index; + elf_getshdrstrndx(elf, &string_index); + + // Notes of the dynamic relocations, packed relocations, and .dynamic + // sections. Found while iterating sections, and later stored in class + // attributes. + Elf_Scn* found_relocations_section = NULL; + Elf_Scn* found_android_relocations_section = NULL; + Elf_Scn* found_dynamic_section = NULL; + + // Notes of relocation section types seen. We require one or the other of + // these; both is unsupported. + bool has_rel_relocations = false; + bool has_rela_relocations = false; + + Elf_Scn* section = NULL; + while ((section = elf_nextscn(elf, section)) != NULL) { + const ELF::Shdr* section_header = ELF::getshdr(section); + std::string name = elf_strptr(elf, string_index, section_header->sh_name); + VerboseLogSectionHeader(name, section_header); + + // Note relocation section types. + if (section_header->sh_type == SHT_REL) { + has_rel_relocations = true; + } + if (section_header->sh_type == SHT_RELA) { + has_rela_relocations = true; + } + + // Note special sections as we encounter them. + if ((name == ".rel.dyn" || name == ".rela.dyn") && + section_header->sh_size > 0) { + found_relocations_section = section; + } + if ((name == ".android.rel.dyn" || name == ".android.rela.dyn") && + section_header->sh_size > 0) { + found_android_relocations_section = section; + } + if (section_header->sh_offset == dynamic_program_header->p_offset) { + found_dynamic_section = section; + } + + // Ensure we preserve alignment, repeated later for the data block(s). + CHECK(section_header->sh_addralign <= kPreserveAlignment); + + Elf_Data* data = NULL; + while ((data = elf_getdata(section, data)) != NULL) { + CHECK(data->d_align <= kPreserveAlignment); + VerboseLogSectionData(data); + } + } + + // Loading failed if we did not find the required special sections. + if (!found_relocations_section) { + LOG(ERROR) << "Missing or empty .rel.dyn or .rela.dyn section"; + return false; + } + if (!found_android_relocations_section) { + LOG(ERROR) << "Missing or empty .android.rel.dyn or .android.rela.dyn " + << "section (to fix, run with --help and follow the " + << "pre-packing instructions)"; + return false; + } + if (!found_dynamic_section) { + LOG(ERROR) << "Missing .dynamic section"; + return false; + } + + // Loading failed if we could not identify the relocations type. + if (!has_rel_relocations && !has_rela_relocations) { + LOG(ERROR) << "No relocations sections found"; + return false; + } + if (has_rel_relocations && has_rela_relocations) { + LOG(ERROR) << "Multiple relocations sections with different types found, " + << "not currently supported"; + return false; + } + + elf_ = elf; + relocations_section_ = found_relocations_section; + dynamic_section_ = found_dynamic_section; + android_relocations_section_ = found_android_relocations_section; + relocations_type_ = has_rel_relocations ? REL : RELA; + return true; +} + +namespace { + +// Helper for ResizeSection(). Adjust the main ELF header for the hole. +void AdjustElfHeaderForHole(ELF::Ehdr* elf_header, + ELF::Off hole_start, + ssize_t hole_size) { + if (elf_header->e_phoff > hole_start) { + elf_header->e_phoff += hole_size; + VLOG(1) << "e_phoff adjusted to " << elf_header->e_phoff; + } + if (elf_header->e_shoff > hole_start) { + elf_header->e_shoff += hole_size; + VLOG(1) << "e_shoff adjusted to " << elf_header->e_shoff; + } +} + +// Helper for ResizeSection(). Adjust all section headers for the hole. +void AdjustSectionHeadersForHole(Elf* elf, + ELF::Off hole_start, + ssize_t hole_size) { + size_t string_index; + elf_getshdrstrndx(elf, &string_index); + + Elf_Scn* section = NULL; + while ((section = elf_nextscn(elf, section)) != NULL) { + ELF::Shdr* section_header = ELF::getshdr(section); + std::string name = elf_strptr(elf, string_index, section_header->sh_name); + + if (section_header->sh_offset > hole_start) { + section_header->sh_offset += hole_size; + VLOG(1) << "section " << name + << " sh_offset adjusted to " << section_header->sh_offset; + } + } +} + +// Helper for ResizeSection(). Adjust the offsets of any program headers +// that have offsets currently beyond the hole start. +void AdjustProgramHeaderOffsets(ELF::Phdr* program_headers, + size_t count, + ELF::Phdr* ignored_1, + ELF::Phdr* ignored_2, + ELF::Off hole_start, + ssize_t hole_size) { + for (size_t i = 0; i < count; ++i) { + ELF::Phdr* program_header = &program_headers[i]; + + if (program_header == ignored_1 || program_header == ignored_2) + continue; + + if (program_header->p_offset > hole_start) { + // The hole start is past this segment, so adjust offset. + program_header->p_offset += hole_size; + VLOG(1) << "phdr[" << i + << "] p_offset adjusted to "<< program_header->p_offset; + } + } +} + +// Helper for ResizeSection(). Find the first loadable segment in the +// file. We expect it to map from file offset zero. +ELF::Phdr* FindFirstLoadSegment(ELF::Phdr* program_headers, + size_t count) { + ELF::Phdr* first_loadable_segment = NULL; + + for (size_t i = 0; i < count; ++i) { + ELF::Phdr* program_header = &program_headers[i]; + + if (program_header->p_type == PT_LOAD && + program_header->p_offset == 0 && + program_header->p_vaddr == 0 && + program_header->p_paddr == 0) { + first_loadable_segment = program_header; + } + } + LOG_IF(FATAL, !first_loadable_segment) + << "Cannot locate a LOAD segment with address and offset zero"; + + return first_loadable_segment; +} + +// Helper for ResizeSection(). Find the PT_GNU_STACK segment, and check +// that it contains what we expect so we can restore it on unpack if needed. +ELF::Phdr* FindUnusedGnuStackSegment(ELF::Phdr* program_headers, + size_t count) { + ELF::Phdr* unused_segment = NULL; + + for (size_t i = 0; i < count; ++i) { + ELF::Phdr* program_header = &program_headers[i]; + + if (program_header->p_type == PT_GNU_STACK && + program_header->p_offset == 0 && + program_header->p_vaddr == 0 && + program_header->p_paddr == 0 && + program_header->p_filesz == 0 && + program_header->p_memsz == 0 && + program_header->p_flags == (PF_R | PF_W) && + program_header->p_align == ELF::kGnuStackSegmentAlignment) { + unused_segment = program_header; + } + } + LOG_IF(FATAL, !unused_segment) + << "Cannot locate the expected GNU_STACK segment"; + + return unused_segment; +} + +// Helper for ResizeSection(). Find the segment that was the first loadable +// one before we split it into two. This is the one into which we coalesce +// the split segments on unpacking. +ELF::Phdr* FindOriginalFirstLoadSegment(ELF::Phdr* program_headers, + size_t count) { + const ELF::Phdr* first_loadable_segment = + FindFirstLoadSegment(program_headers, count); + + ELF::Phdr* original_first_loadable_segment = NULL; + + for (size_t i = 0; i < count; ++i) { + ELF::Phdr* program_header = &program_headers[i]; + + // The original first loadable segment is the one that follows on from + // the one we wrote on split to be the current first loadable segment. + if (program_header->p_type == PT_LOAD && + program_header->p_offset == first_loadable_segment->p_filesz) { + original_first_loadable_segment = program_header; + } + } + LOG_IF(FATAL, !original_first_loadable_segment) + << "Cannot locate the LOAD segment that follows a LOAD at offset zero"; + + return original_first_loadable_segment; +} + +// Helper for ResizeSection(). Find the segment that contains the hole. +Elf_Scn* FindSectionContainingHole(Elf* elf, + ELF::Off hole_start, + ssize_t hole_size) { + Elf_Scn* section = NULL; + Elf_Scn* last_unholed_section = NULL; + + while ((section = elf_nextscn(elf, section)) != NULL) { + const ELF::Shdr* section_header = ELF::getshdr(section); + + // Because we get here after section headers have been adjusted for the + // hole, we need to 'undo' that adjustment to give a view of the original + // sections layout. + ELF::Off offset = section_header->sh_offset; + if (section_header->sh_offset >= hole_start) { + offset -= hole_size; + } + + if (offset <= hole_start) { + last_unholed_section = section; + } + } + LOG_IF(FATAL, !last_unholed_section) + << "Cannot identify the section before the one containing the hole"; + + // The section containing the hole is the one after the last one found + // by the loop above. + Elf_Scn* holed_section = elf_nextscn(elf, last_unholed_section); + LOG_IF(FATAL, !holed_section) + << "Cannot identify the section containing the hole"; + + return holed_section; +} + +// Helper for ResizeSection(). Find the last section contained in a segment. +Elf_Scn* FindLastSectionInSegment(Elf* elf, + ELF::Phdr* program_header, + ELF::Off hole_start, + ssize_t hole_size) { + const ELF::Off segment_end = + program_header->p_offset + program_header->p_filesz; + + Elf_Scn* section = NULL; + Elf_Scn* last_section = NULL; + + while ((section = elf_nextscn(elf, section)) != NULL) { + const ELF::Shdr* section_header = ELF::getshdr(section); + + // As above, 'undo' any section offset adjustment to give a view of the + // original sections layout. + ELF::Off offset = section_header->sh_offset; + if (section_header->sh_offset >= hole_start) { + offset -= hole_size; + } + + if (offset < segment_end) { + last_section = section; + } + } + LOG_IF(FATAL, !last_section) + << "Cannot identify the last section in the given segment"; + + return last_section; +} + +// Helper for ResizeSection(). Order loadable segments by their offsets. +// The crazy linker contains assumptions about loadable segment ordering, +// and it is better if we do not break them. +void SortOrderSensitiveProgramHeaders(ELF::Phdr* program_headers, + size_t count) { + std::vector<ELF::Phdr*> orderable; + + // Collect together orderable program headers. These are all the LOAD + // segments, and any GNU_STACK that may be present (removed on packing, + // but replaced on unpacking). + for (size_t i = 0; i < count; ++i) { + ELF::Phdr* program_header = &program_headers[i]; + + if (program_header->p_type == PT_LOAD || + program_header->p_type == PT_GNU_STACK) { + orderable.push_back(program_header); + } + } + + // Order these program headers so that any PT_GNU_STACK is last, and + // the LOAD segments that precede it appear in offset order. Uses + // insertion sort. + for (size_t i = 1; i < orderable.size(); ++i) { + for (size_t j = i; j > 0; --j) { + ELF::Phdr* first = orderable[j - 1]; + ELF::Phdr* second = orderable[j]; + + if (!(first->p_type == PT_GNU_STACK || + first->p_offset > second->p_offset)) { + break; + } + std::swap(*first, *second); + } + } +} + +// Helper for ResizeSection(). The GNU_STACK program header is unused in +// Android, so we can repurpose it here. Before packing, the program header +// table contains something like: +// +// Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align +// LOAD 0x000000 0x00000000 0x00000000 0x1efc818 0x1efc818 R E 0x1000 +// LOAD 0x1efd008 0x01efe008 0x01efe008 0x17ec3c 0x1a0324 RW 0x1000 +// DYNAMIC 0x205ec50 0x0205fc50 0x0205fc50 0x00108 0x00108 RW 0x4 +// GNU_STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RW 0 +// +// The hole in the file is in the first of these. In order to preserve all +// load addresses, what we do is to turn the GNU_STACK into a new LOAD entry +// that maps segments up to where we created the hole, adjust the first LOAD +// entry so that it maps segments after that, adjust any other program +// headers whose offset is after the hole start, and finally order the LOAD +// segments by offset, to give: +// +// Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align +// LOAD 0x000000 0x00000000 0x00000000 0x14ea4 0x14ea4 R E 0x1000 +// LOAD 0x014ea4 0x00212ea4 0x00212ea4 0x1cea164 0x1cea164 R E 0x1000 +// DYNAMIC 0x1e60c50 0x0205fc50 0x0205fc50 0x00108 0x00108 RW 0x4 +// LOAD 0x1cff008 0x01efe008 0x01efe008 0x17ec3c 0x1a0324 RW 0x1000 +// +// We work out the split points by finding the .rel.dyn or .rela.dyn section +// that contains the hole, and by finding the last section in a given segment. +// +// To unpack, we reverse the above to leave the file as it was originally. +void SplitProgramHeadersForHole(Elf* elf, + ELF::Off hole_start, + ssize_t hole_size) { + CHECK(hole_size < 0); + const ELF::Ehdr* elf_header = ELF::getehdr(elf); + CHECK(elf_header); + + ELF::Phdr* elf_program_header = ELF::getphdr(elf); + CHECK(elf_program_header); + + const size_t program_header_count = elf_header->e_phnum; + + // Locate the segment that we can overwrite to form the new LOAD entry, + // and the segment that we are going to split into two parts. + ELF::Phdr* spliced_header = + FindUnusedGnuStackSegment(elf_program_header, program_header_count); + ELF::Phdr* split_header = + FindFirstLoadSegment(elf_program_header, program_header_count); + + VLOG(1) << "phdr[" << split_header - elf_program_header << "] split"; + VLOG(1) << "phdr[" << spliced_header - elf_program_header << "] new LOAD"; + + // Find the section that contains the hole. We split on the section that + // follows it. + Elf_Scn* holed_section = + FindSectionContainingHole(elf, hole_start, hole_size); + + size_t string_index; + elf_getshdrstrndx(elf, &string_index); + + ELF::Shdr* section_header = ELF::getshdr(holed_section); + std::string name = elf_strptr(elf, string_index, section_header->sh_name); + VLOG(1) << "section " << name << " split after"; + + // Find the last section in the segment we are splitting. + Elf_Scn* last_section = + FindLastSectionInSegment(elf, split_header, hole_start, hole_size); + + section_header = ELF::getshdr(last_section); + name = elf_strptr(elf, string_index, section_header->sh_name); + VLOG(1) << "section " << name << " split end"; + + // Split on the section following the holed one, and up to (but not + // including) the section following the last one in the split segment. + Elf_Scn* split_section = elf_nextscn(elf, holed_section); + LOG_IF(FATAL, !split_section) + << "No section follows the section that contains the hole"; + Elf_Scn* end_section = elf_nextscn(elf, last_section); + LOG_IF(FATAL, !end_section) + << "No section follows the last section in the segment being split"; + + // Split the first portion of split_header into spliced_header. + const ELF::Shdr* split_section_header = ELF::getshdr(split_section); + spliced_header->p_type = split_header->p_type; + spliced_header->p_offset = split_header->p_offset; + spliced_header->p_vaddr = split_header->p_vaddr; + spliced_header->p_paddr = split_header->p_paddr; + CHECK(split_header->p_filesz == split_header->p_memsz); + spliced_header->p_filesz = split_section_header->sh_offset; + spliced_header->p_memsz = split_section_header->sh_offset; + spliced_header->p_flags = split_header->p_flags; + spliced_header->p_align = split_header->p_align; + + // Now rewrite split_header to remove the part we spliced from it. + const ELF::Shdr* end_section_header = ELF::getshdr(end_section); + split_header->p_offset = spliced_header->p_filesz; + CHECK(split_header->p_vaddr == split_header->p_paddr); + split_header->p_vaddr = split_section_header->sh_addr; + split_header->p_paddr = split_section_header->sh_addr; + CHECK(split_header->p_filesz == split_header->p_memsz); + split_header->p_filesz = + end_section_header->sh_offset - spliced_header->p_filesz; + split_header->p_memsz = + end_section_header->sh_offset - spliced_header->p_filesz; + + // Adjust the offsets of all program headers that are not one of the pair + // we just created by splitting. + AdjustProgramHeaderOffsets(elf_program_header, + program_header_count, + spliced_header, + split_header, + hole_start, + hole_size); + + // Finally, order loadable segments by offset/address. The crazy linker + // contains assumptions about loadable segment ordering. + SortOrderSensitiveProgramHeaders(elf_program_header, + program_header_count); +} + +// Helper for ResizeSection(). Undo the work of SplitProgramHeadersForHole(). +void CoalesceProgramHeadersForHole(Elf* elf, + ELF::Off hole_start, + ssize_t hole_size) { + CHECK(hole_size > 0); + const ELF::Ehdr* elf_header = ELF::getehdr(elf); + CHECK(elf_header); + + ELF::Phdr* elf_program_header = ELF::getphdr(elf); + CHECK(elf_program_header); + + const size_t program_header_count = elf_header->e_phnum; + + // Locate the segment that we overwrote to form the new LOAD entry, and + // the segment that we split into two parts on packing. + ELF::Phdr* spliced_header = + FindFirstLoadSegment(elf_program_header, program_header_count); + ELF::Phdr* split_header = + FindOriginalFirstLoadSegment(elf_program_header, program_header_count); + + VLOG(1) << "phdr[" << spliced_header - elf_program_header << "] stack"; + VLOG(1) << "phdr[" << split_header - elf_program_header << "] coalesce"; + + // Find the last section in the second segment we are coalescing. + Elf_Scn* last_section = + FindLastSectionInSegment(elf, split_header, hole_start, hole_size); + + size_t string_index; + elf_getshdrstrndx(elf, &string_index); + + const ELF::Shdr* section_header = ELF::getshdr(last_section); + std::string name = elf_strptr(elf, string_index, section_header->sh_name); + VLOG(1) << "section " << name << " coalesced"; + + // Rewrite the coalesced segment into split_header. + const ELF::Shdr* last_section_header = ELF::getshdr(last_section); + split_header->p_offset = spliced_header->p_offset; + CHECK(split_header->p_vaddr == split_header->p_paddr); + split_header->p_vaddr = spliced_header->p_vaddr; + split_header->p_paddr = spliced_header->p_vaddr; + CHECK(split_header->p_filesz == split_header->p_memsz); + split_header->p_filesz = + last_section_header->sh_offset + last_section_header->sh_size; + split_header->p_memsz = + last_section_header->sh_offset + last_section_header->sh_size; + + // Reconstruct the original GNU_STACK segment into spliced_header. + spliced_header->p_type = PT_GNU_STACK; + spliced_header->p_offset = 0; + spliced_header->p_vaddr = 0; + spliced_header->p_paddr = 0; + spliced_header->p_filesz = 0; + spliced_header->p_memsz = 0; + spliced_header->p_flags = PF_R | PF_W; + spliced_header->p_align = ELF::kGnuStackSegmentAlignment; + + // Adjust the offsets of all program headers that are not one of the pair + // we just coalesced. + AdjustProgramHeaderOffsets(elf_program_header, + program_header_count, + spliced_header, + split_header, + hole_start, + hole_size); + + // Finally, order loadable segments by offset/address. The crazy linker + // contains assumptions about loadable segment ordering. + SortOrderSensitiveProgramHeaders(elf_program_header, + program_header_count); +} + +// Helper for ResizeSection(). Rewrite program headers. +void RewriteProgramHeadersForHole(Elf* elf, + ELF::Off hole_start, + ssize_t hole_size) { + // If hole_size is negative then we are removing a piece of the file, and + // we want to split program headers so that we keep the same addresses + // for text and data. If positive, then we are putting that piece of the + // file back in, so we coalesce the previously split program headers. + if (hole_size < 0) + SplitProgramHeadersForHole(elf, hole_start, hole_size); + else if (hole_size > 0) + CoalesceProgramHeadersForHole(elf, hole_start, hole_size); +} + +// Helper for ResizeSection(). Locate and return the dynamic section. +Elf_Scn* GetDynamicSection(Elf* elf) { + const ELF::Ehdr* elf_header = ELF::getehdr(elf); + CHECK(elf_header); + + const ELF::Phdr* elf_program_header = ELF::getphdr(elf); + CHECK(elf_program_header); + + // Find the program header that describes the dynamic section. + const ELF::Phdr* dynamic_program_header = NULL; + for (size_t i = 0; i < elf_header->e_phnum; ++i) { + const ELF::Phdr* program_header = &elf_program_header[i]; + + if (program_header->p_type == PT_DYNAMIC) { + dynamic_program_header = program_header; + } + } + CHECK(dynamic_program_header); + + // Now find the section with the same offset as this program header. + Elf_Scn* dynamic_section = NULL; + Elf_Scn* section = NULL; + while ((section = elf_nextscn(elf, section)) != NULL) { + ELF::Shdr* section_header = ELF::getshdr(section); + + if (section_header->sh_offset == dynamic_program_header->p_offset) { + dynamic_section = section; + } + } + CHECK(dynamic_section != NULL); + + return dynamic_section; +} + +// Helper for ResizeSection(). Adjust the .dynamic section for the hole. +template <typename Rel> +void AdjustDynamicSectionForHole(Elf_Scn* dynamic_section, + ELF::Off hole_start, + ssize_t hole_size) { + Elf_Data* data = GetSectionData(dynamic_section); + + const ELF::Dyn* dynamic_base = reinterpret_cast<ELF::Dyn*>(data->d_buf); + std::vector<ELF::Dyn> dynamics( + dynamic_base, + dynamic_base + data->d_size / sizeof(dynamics[0])); + + for (size_t i = 0; i < dynamics.size(); ++i) { + ELF::Dyn* dynamic = &dynamics[i]; + const ELF::Sword tag = dynamic->d_tag; + + // DT_RELSZ or DT_RELASZ indicate the overall size of relocations. + // Only one will be present. Adjust by hole size. + if (tag == DT_RELSZ || tag == DT_RELASZ) { + dynamic->d_un.d_val += hole_size; + VLOG(1) << "dynamic[" << i << "] " << dynamic->d_tag + << " d_val adjusted to " << dynamic->d_un.d_val; + } + + // DT_RELCOUNT or DT_RELACOUNT hold the count of relative relocations. + // Only one will be present. Packing reduces it to the alignment + // padding, if any; unpacking restores it to its former value. The + // crazy linker does not use it, but we update it anyway. + if (tag == DT_RELCOUNT || tag == DT_RELACOUNT) { + // Cast sizeof to a signed type to avoid the division result being + // promoted into an unsigned size_t. + const ssize_t sizeof_rel = static_cast<ssize_t>(sizeof(Rel)); + dynamic->d_un.d_val += hole_size / sizeof_rel; + VLOG(1) << "dynamic[" << i << "] " << dynamic->d_tag + << " d_val adjusted to " << dynamic->d_un.d_val; + } + + // DT_RELENT and DT_RELAENT do not change, but make sure they are what + // we expect. Only one will be present. + if (tag == DT_RELENT || tag == DT_RELAENT) { + CHECK(dynamic->d_un.d_val == sizeof(Rel)); + } + } + + void* section_data = &dynamics[0]; + size_t bytes = dynamics.size() * sizeof(dynamics[0]); + RewriteSectionData(dynamic_section, section_data, bytes); +} + +// Resize a section. If the new size is larger than the current size, open +// up a hole by increasing file offsets that come after the hole. If smaller +// than the current size, remove the hole by decreasing those offsets. +template <typename Rel> +void ResizeSection(Elf* elf, Elf_Scn* section, size_t new_size) { + ELF::Shdr* section_header = ELF::getshdr(section); + if (section_header->sh_size == new_size) + return; + + // Note if we are resizing the real dyn relocations. + size_t string_index; + elf_getshdrstrndx(elf, &string_index); + const std::string section_name = + elf_strptr(elf, string_index, section_header->sh_name); + const bool is_relocations_resize = + (section_name == ".rel.dyn" || section_name == ".rela.dyn"); + + // Require that the section size and the data size are the same. True + // in practice for all sections we resize when packing or unpacking. + Elf_Data* data = GetSectionData(section); + CHECK(data->d_off == 0 && data->d_size == section_header->sh_size); + + // Require that the section is not zero-length (that is, has allocated + // data that we can validly expand). + CHECK(data->d_size && data->d_buf); + + const ELF::Off hole_start = section_header->sh_offset; + const ssize_t hole_size = new_size - data->d_size; + + VLOG_IF(1, (hole_size > 0)) << "expand section size = " << data->d_size; + VLOG_IF(1, (hole_size < 0)) << "shrink section size = " << data->d_size; + + // Resize the data and the section header. + data->d_size += hole_size; + section_header->sh_size += hole_size; + + // Add the hole size to all offsets in the ELF file that are after the + // start of the hole. If the hole size is positive we are expanding the + // section to create a new hole; if negative, we are closing up a hole. + + // Start with the main ELF header. + ELF::Ehdr* elf_header = ELF::getehdr(elf); + AdjustElfHeaderForHole(elf_header, hole_start, hole_size); + + // Adjust all section headers. + AdjustSectionHeadersForHole(elf, hole_start, hole_size); + + // If resizing the dynamic relocations, rewrite the program headers to + // either split or coalesce segments, and adjust dynamic entries to match. + if (is_relocations_resize) { + RewriteProgramHeadersForHole(elf, hole_start, hole_size); + + Elf_Scn* dynamic_section = GetDynamicSection(elf); + AdjustDynamicSectionForHole<Rel>(dynamic_section, hole_start, hole_size); + } +} + +// Find the first slot in a dynamics array with the given tag. The array +// always ends with a free (unused) element, and which we exclude from the +// search. Returns dynamics->size() if not found. +size_t FindDynamicEntry(ELF::Sword tag, + std::vector<ELF::Dyn>* dynamics) { + // Loop until the penultimate entry. We exclude the end sentinel. + for (size_t i = 0; i < dynamics->size() - 1; ++i) { + if (dynamics->at(i).d_tag == tag) + return i; + } + + // The tag was not found. + return dynamics->size(); +} + +// Replace the first free (unused) slot in a dynamics vector with the given +// value. The vector always ends with a free (unused) element, so the slot +// found cannot be the last one in the vector. +void AddDynamicEntry(const ELF::Dyn& dyn, + std::vector<ELF::Dyn>* dynamics) { + const size_t slot = FindDynamicEntry(DT_NULL, dynamics); + if (slot == dynamics->size()) { + LOG(FATAL) << "No spare dynamic array slots found " + << "(to fix, increase gold's --spare-dynamic-tags value)"; + } + + // Replace this entry with the one supplied. + dynamics->at(slot) = dyn; + VLOG(1) << "dynamic[" << slot << "] overwritten with " << dyn.d_tag; +} + +// Remove the element in the dynamics vector that matches the given tag with +// unused slot data. Shuffle the following elements up, and ensure that the +// last is the null sentinel. +void RemoveDynamicEntry(ELF::Sword tag, + std::vector<ELF::Dyn>* dynamics) { + const size_t slot = FindDynamicEntry(tag, dynamics); + CHECK(slot != dynamics->size()); + + // Remove this entry by shuffling up everything that follows. + for (size_t i = slot; i < dynamics->size() - 1; ++i) { + dynamics->at(i) = dynamics->at(i + 1); + VLOG(1) << "dynamic[" << i + << "] overwritten with dynamic[" << i + 1 << "]"; + } + + // Ensure that the end sentinel is still present. + CHECK(dynamics->at(dynamics->size() - 1).d_tag == DT_NULL); +} + +// Construct a null relocation without addend. +void NullRelocation(ELF::Rel* relocation) { + relocation->r_offset = 0; + relocation->r_info = ELF_R_INFO(0, ELF::kNoRelocationCode); +} + +// Construct a null relocation with addend. +void NullRelocation(ELF::Rela* relocation) { + relocation->r_offset = 0; + relocation->r_info = ELF_R_INFO(0, ELF::kNoRelocationCode); + relocation->r_addend = 0; +} + +// Pad relocations with the given number of null entries. Generates its +// null entry with the appropriate NullRelocation() invocation. +template <typename Rel> +void PadRelocations(size_t count, std::vector<Rel>* relocations) { + Rel null_relocation; + NullRelocation(&null_relocation); + std::vector<Rel> padding(count, null_relocation); + relocations->insert(relocations->end(), padding.begin(), padding.end()); +} + +} // namespace + +// Remove relative entries from dynamic relocations and write as packed +// data into android packed relocations. +bool ElfFile::PackRelocations() { + // Load the ELF file into libelf. + if (!Load()) { + LOG(ERROR) << "Failed to load as ELF"; + return false; + } + + // Retrieve the current dynamic relocations section data. + Elf_Data* data = GetSectionData(relocations_section_); + + if (relocations_type_ == REL) { + // Convert data to a vector of relocations. + const ELF::Rel* relocations_base = reinterpret_cast<ELF::Rel*>(data->d_buf); + std::vector<ELF::Rel> relocations( + relocations_base, + relocations_base + data->d_size / sizeof(relocations[0])); + + LOG(INFO) << "Relocations : REL"; + return PackTypedRelocations<ELF::Rel>(relocations); + } + + if (relocations_type_ == RELA) { + // Convert data to a vector of relocations with addends. + const ELF::Rela* relocations_base = + reinterpret_cast<ELF::Rela*>(data->d_buf); + std::vector<ELF::Rela> relocations( + relocations_base, + relocations_base + data->d_size / sizeof(relocations[0])); + + LOG(INFO) << "Relocations : RELA"; + return PackTypedRelocations<ELF::Rela>(relocations); + } + + NOTREACHED(); + return false; +} + +// Helper for PackRelocations(). Rel type is one of ELF::Rel or ELF::Rela. +template <typename Rel> +bool ElfFile::PackTypedRelocations(const std::vector<Rel>& relocations) { + // Filter relocations into those that are relative and others. + std::vector<Rel> relative_relocations; + std::vector<Rel> other_relocations; + + for (size_t i = 0; i < relocations.size(); ++i) { + const Rel& relocation = relocations[i]; + if (ELF_R_TYPE(relocation.r_info) == ELF::kRelativeRelocationCode) { + CHECK(ELF_R_SYM(relocation.r_info) == 0); + relative_relocations.push_back(relocation); + } else { + other_relocations.push_back(relocation); + } + } + LOG(INFO) << "Relative : " << relative_relocations.size() << " entries"; + LOG(INFO) << "Other : " << other_relocations.size() << " entries"; + LOG(INFO) << "Total : " << relocations.size() << " entries"; + + // If no relative relocations then we have nothing packable. Perhaps + // the shared object has already been packed? + if (relative_relocations.empty()) { + LOG(ERROR) << "No relative relocations found (already packed?)"; + return false; + } + + // If not padding fully, apply only enough padding to preserve alignment. + // Otherwise, pad so that we do not shrink the relocations section at all. + if (!is_padding_relocations_) { + // Calculate the size of the hole we will close up when we rewrite + // dynamic relocations. + ssize_t hole_size = + relative_relocations.size() * sizeof(relative_relocations[0]); + const ssize_t unaligned_hole_size = hole_size; + + // Adjust the actual hole size to preserve alignment. We always adjust + // by a whole number of NONE-type relocations. + while (hole_size % kPreserveAlignment) + hole_size -= sizeof(relative_relocations[0]); + LOG(INFO) << "Compaction : " << hole_size << " bytes"; + + // Adjusting for alignment may have removed any packing benefit. + if (hole_size == 0) { + LOG(INFO) << "Too few relative relocations to pack after alignment"; + return false; + } + + // Find the padding needed in other_relocations to preserve alignment. + // Ensure that we never completely empty the real relocations section. + size_t padding_bytes = unaligned_hole_size - hole_size; + if (padding_bytes == 0 && other_relocations.size() == 0) { + do { + padding_bytes += sizeof(relative_relocations[0]); + } while (padding_bytes % kPreserveAlignment); + } + CHECK(padding_bytes % sizeof(other_relocations[0]) == 0); + const size_t padding = padding_bytes / sizeof(other_relocations[0]); + + // Padding may have removed any packing benefit. + if (padding >= relative_relocations.size()) { + LOG(INFO) << "Too few relative relocations to pack after padding"; + return false; + } + + // Add null relocations to other_relocations to preserve alignment. + PadRelocations<Rel>(padding, &other_relocations); + LOG(INFO) << "Alignment pad : " << padding << " relocations"; + } else { + // If padding, add NONE-type relocations to other_relocations to make it + // the same size as the the original relocations we read in. This makes + // the ResizeSection() below a no-op. + const size_t padding = relocations.size() - other_relocations.size(); + PadRelocations<Rel>(padding, &other_relocations); + } + + // Pack relative relocations. + const size_t initial_bytes = + relative_relocations.size() * sizeof(relative_relocations[0]); + LOG(INFO) << "Unpacked relative: " << initial_bytes << " bytes"; + std::vector<uint8_t> packed; + RelocationPacker packer; + packer.PackRelativeRelocations(relative_relocations, &packed); + const void* packed_data = &packed[0]; + const size_t packed_bytes = packed.size() * sizeof(packed[0]); + LOG(INFO) << "Packed relative: " << packed_bytes << " bytes"; + + // If we have insufficient relative relocations to form a run then + // packing fails. + if (packed.empty()) { + LOG(INFO) << "Too few relative relocations to pack"; + return false; + } + + // Run a loopback self-test as a check that packing is lossless. + std::vector<Rel> unpacked; + packer.UnpackRelativeRelocations(packed, &unpacked); + CHECK(unpacked.size() == relative_relocations.size()); + CHECK(!memcmp(&unpacked[0], + &relative_relocations[0], + unpacked.size() * sizeof(unpacked[0]))); + + // Make sure packing saved some space. + if (packed_bytes >= initial_bytes) { + LOG(INFO) << "Packing relative relocations saves no space"; + return false; + } + + // Rewrite the current dynamic relocations section to be only the ARM + // non-relative relocations, then shrink it to size. + const void* section_data = &other_relocations[0]; + const size_t bytes = other_relocations.size() * sizeof(other_relocations[0]); + ResizeSection<Rel>(elf_, relocations_section_, bytes); + RewriteSectionData(relocations_section_, section_data, bytes); + + // Rewrite the current packed android relocations section to hold the packed + // relative relocations. + ResizeSection<Rel>(elf_, android_relocations_section_, packed_bytes); + RewriteSectionData(android_relocations_section_, packed_data, packed_bytes); + + // Rewrite .dynamic to include two new tags describing the packed android + // relocations. + Elf_Data* data = GetSectionData(dynamic_section_); + const ELF::Dyn* dynamic_base = reinterpret_cast<ELF::Dyn*>(data->d_buf); + std::vector<ELF::Dyn> dynamics( + dynamic_base, + dynamic_base + data->d_size / sizeof(dynamics[0])); + // Use two of the spare slots to describe the packed section. + ELF::Shdr* section_header = ELF::getshdr(android_relocations_section_); + { + ELF::Dyn dyn; + dyn.d_tag = DT_ANDROID_REL_OFFSET; + dyn.d_un.d_ptr = section_header->sh_offset; + AddDynamicEntry(dyn, &dynamics); + } + { + ELF::Dyn dyn; + dyn.d_tag = DT_ANDROID_REL_SIZE; + dyn.d_un.d_val = section_header->sh_size; + AddDynamicEntry(dyn, &dynamics); + } + const void* dynamics_data = &dynamics[0]; + const size_t dynamics_bytes = dynamics.size() * sizeof(dynamics[0]); + RewriteSectionData(dynamic_section_, dynamics_data, dynamics_bytes); + + Flush(); + return true; +} + +// Find packed relative relocations in the packed android relocations +// section, unpack them, and rewrite the dynamic relocations section to +// contain unpacked data. +bool ElfFile::UnpackRelocations() { + // Load the ELF file into libelf. + if (!Load()) { + LOG(ERROR) << "Failed to load as ELF"; + return false; + } + + // Retrieve the current packed android relocations section data. + Elf_Data* data = GetSectionData(android_relocations_section_); + + // Convert data to a vector of bytes. + const uint8_t* packed_base = reinterpret_cast<uint8_t*>(data->d_buf); + std::vector<uint8_t> packed( + packed_base, + packed_base + data->d_size / sizeof(packed[0])); + + if (packed.size() > 3 && + packed[0] == 'A' && + packed[1] == 'P' && + packed[2] == 'R' && + packed[3] == '1') { + // Signature is APR1, unpack relocations. + CHECK(relocations_type_ == REL); + LOG(INFO) << "Relocations : REL"; + return UnpackTypedRelocations<ELF::Rel>(packed); + } + + if (packed.size() > 3 && + packed[0] == 'A' && + packed[1] == 'P' && + packed[2] == 'A' && + packed[3] == '1') { + // Signature is APA1, unpack relocations with addends. + CHECK(relocations_type_ == RELA); + LOG(INFO) << "Relocations : RELA"; + return UnpackTypedRelocations<ELF::Rela>(packed); + } + + LOG(ERROR) << "Packed relative relocations not found (not packed?)"; + return false; +} + +// Helper for UnpackRelocations(). Rel type is one of ELF::Rel or ELF::Rela. +template <typename Rel> +bool ElfFile::UnpackTypedRelocations(const std::vector<uint8_t>& packed) { + // Unpack the data to re-materialize the relative relocations. + const size_t packed_bytes = packed.size() * sizeof(packed[0]); + LOG(INFO) << "Packed relative: " << packed_bytes << " bytes"; + std::vector<Rel> relative_relocations; + RelocationPacker packer; + packer.UnpackRelativeRelocations(packed, &relative_relocations); + const size_t unpacked_bytes = + relative_relocations.size() * sizeof(relative_relocations[0]); + LOG(INFO) << "Unpacked relative: " << unpacked_bytes << " bytes"; + + // Retrieve the current dynamic relocations section data. + Elf_Data* data = GetSectionData(relocations_section_); + + // Interpret data as relocations. + const Rel* relocations_base = reinterpret_cast<Rel*>(data->d_buf); + std::vector<Rel> relocations( + relocations_base, + relocations_base + data->d_size / sizeof(relocations[0])); + + std::vector<Rel> other_relocations; + size_t padding = 0; + + // Filter relocations to locate any that are NONE-type. These will occur + // if padding was turned on for packing. + for (size_t i = 0; i < relocations.size(); ++i) { + const Rel& relocation = relocations[i]; + if (ELF_R_TYPE(relocation.r_info) != ELF::kNoRelocationCode) { + other_relocations.push_back(relocation); + } else { + ++padding; + } + } + LOG(INFO) << "Relative : " << relative_relocations.size() << " entries"; + LOG(INFO) << "Other : " << other_relocations.size() << " entries"; + + // If we found the same number of null relocation entries in the dynamic + // relocations section as we hold as unpacked relative relocations, then + // this is a padded file. + const bool is_padded = padding == relative_relocations.size(); + + // Unless padded, report by how much we expand the file. + if (!is_padded) { + // Calculate the size of the hole we will open up when we rewrite + // dynamic relocations. + ssize_t hole_size = + relative_relocations.size() * sizeof(relative_relocations[0]); + + // Adjust the hole size for the padding added to preserve alignment. + hole_size -= padding * sizeof(other_relocations[0]); + LOG(INFO) << "Expansion : " << hole_size << " bytes"; + } + + // Rewrite the current dynamic relocations section to be the relative + // relocations followed by other relocations. This is the usual order in + // which we find them after linking, so this action will normally put the + // entire dynamic relocations section back to its pre-split-and-packed state. + relocations.assign(relative_relocations.begin(), relative_relocations.end()); + relocations.insert(relocations.end(), + other_relocations.begin(), other_relocations.end()); + const void* section_data = &relocations[0]; + const size_t bytes = relocations.size() * sizeof(relocations[0]); + LOG(INFO) << "Total : " << relocations.size() << " entries"; + ResizeSection<Rel>(elf_, relocations_section_, bytes); + RewriteSectionData(relocations_section_, section_data, bytes); + + // Nearly empty the current packed android relocations section. Leaves a + // four-byte stub so that some data remains allocated to the section. + // This is a convenience which allows us to re-pack this file again without + // having to remove the section and then add a new small one with objcopy. + // The way we resize sections relies on there being some data in a section. + ResizeSection<Rel>( + elf_, android_relocations_section_, sizeof(kStubIdentifier)); + RewriteSectionData( + android_relocations_section_, &kStubIdentifier, sizeof(kStubIdentifier)); + + // Rewrite .dynamic to remove two tags describing packed android relocations. + data = GetSectionData(dynamic_section_); + const ELF::Dyn* dynamic_base = reinterpret_cast<ELF::Dyn*>(data->d_buf); + std::vector<ELF::Dyn> dynamics( + dynamic_base, + dynamic_base + data->d_size / sizeof(dynamics[0])); + RemoveDynamicEntry(DT_ANDROID_REL_OFFSET, &dynamics); + RemoveDynamicEntry(DT_ANDROID_REL_SIZE, &dynamics); + const void* dynamics_data = &dynamics[0]; + const size_t dynamics_bytes = dynamics.size() * sizeof(dynamics[0]); + RewriteSectionData(dynamic_section_, dynamics_data, dynamics_bytes); + + Flush(); + return true; +} + +// Flush rewritten shared object file data. +void ElfFile::Flush() { + // Flag all ELF data held in memory as needing to be written back to the + // file, and tell libelf that we have controlled the file layout. + elf_flagelf(elf_, ELF_C_SET, ELF_F_DIRTY); + elf_flagelf(elf_, ELF_C_SET, ELF_F_LAYOUT); + + // Write ELF data back to disk. + const off_t file_bytes = elf_update(elf_, ELF_C_WRITE); + CHECK(file_bytes > 0); + VLOG(1) << "elf_update returned: " << file_bytes; + + // Clean up libelf, and truncate the output file to the number of bytes + // written by elf_update(). + elf_end(elf_); + elf_ = NULL; + const int truncate = ftruncate(fd_, file_bytes); + CHECK(truncate == 0); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/elf_file.h b/tools/relocation_packer/src/elf_file.h new file mode 100644 index 0000000..6550274 --- /dev/null +++ b/tools/relocation_packer/src/elf_file.h @@ -0,0 +1,134 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// ELF shared object file updates handler. +// +// Provides functions to remove relative relocations from the .rel.dyn +// or .rela.dyn sections and pack into .android.rel.dyn or .android.rela.dyn, +// and unpack to return the file to its pre-packed state. +// +// Files to be packed or unpacked must include an existing .android.rel.dyn +// or android.rela.dyn section. A standard libchrome.<version>.so will not +// contain this section, so the following can be used to add one: +// +// echo -n 'NULL' >/tmp/small +// if file libchrome.<version>.so | grep -q 'ELF 32'; then +// arm-linux-androideabi-objcopy +// --add-section .android.rel.dyn=/tmp/small +// libchrome.<version>.so libchrome.<version>.so.packed +// else +// aarch64-linux-android-objcopy +// --add-section .android.rela.dyn=/tmp/small +// libchrome.<version>.so libchrome.<version>.so.packed +// fi +// rm /tmp/small +// +// To use, open the file and pass the file descriptor to the constructor, +// then pack or unpack as desired. Packing or unpacking will flush the file +// descriptor on success. Example: +// +// int fd = open(..., O_RDWR); +// ElfFile elf_file(fd); +// bool status; +// if (is_packing) +// status = elf_file.PackRelocations(); +// else +// status = elf_file.UnpackRelocations(); +// close(fd); +// +// SetPadding() causes PackRelocations() to pad .rel.dyn or .rela.dyn with +// NONE-type entries rather than cutting a hole out of the shared object +// file. This keeps all load addresses and offsets constant, and enables +// easier debugging and testing. +// +// A packed shared object file has all of its relative relocations +// removed from .rel.dyn or .rela.dyn, and replaced as packed data in +// .android.rel.dyn or .android.rela.dyn respectively. The resulting file +// is shorter than its non-packed original. +// +// Unpacking a packed file restores the file to its non-packed state, by +// expanding the packed data in .android.rel.dyn or .android.rela.dyn, +// combining the relative relocations with the data already in .rel.dyn +// or .rela.dyn, and then writing back the now expanded section. + +#ifndef TOOLS_RELOCATION_PACKER_SRC_ELF_FILE_H_ +#define TOOLS_RELOCATION_PACKER_SRC_ELF_FILE_H_ + +#include <string.h> +#include <vector> + +#include "elf.h" +#include "libelf.h" +#include "packer.h" + +namespace relocation_packer { + +// An ElfFile reads shared objects, and shuttles relative relocations +// between .rel.dyn or .rela.dyn and .android.rel.dyn or .android.rela.dyn +// sections. +class ElfFile { + public: + explicit ElfFile(int fd) + : fd_(fd), is_padding_relocations_(false), elf_(NULL), + relocations_section_(NULL), dynamic_section_(NULL), + android_relocations_section_(NULL), relocations_type_(NONE) {} + ~ElfFile() {} + + // Set padding mode. When padding, PackRelocations() will not shrink + // the .rel.dyn or .rela.dyn section, but instead replace relative with + // NONE-type entries. + // |flag| is true to pad .rel.dyn or .rela.dyn, false to shrink it. + inline void SetPadding(bool flag) { is_padding_relocations_ = flag; } + + // Transfer relative relocations from .rel.dyn or .rela.dyn to a packed + // representation in .android.rel.dyn or .android.rela.dyn. Returns true + // on success. + bool PackRelocations(); + + // Transfer relative relocations from a packed representation in + // .android.rel.dyn or .android.rela.dyn to .rel.dyn or .rela.dyn. Returns + // true on success. + bool UnpackRelocations(); + + private: + // Load a new ElfFile from a filedescriptor. If flushing, the file must + // be open for read/write. Returns true on successful ELF file load. + // |fd| is an open file descriptor for the shared object. + bool Load(); + + // Templated packer, helper for PackRelocations(). Rel type is one of + // ELF::Rel or ELF::Rela. + template <typename Rel> + bool PackTypedRelocations(const std::vector<Rel>& relocations); + + // Templated unpacker, helper for UnpackRelocations(). Rel type is one of + // ELF::Rel or ELF::Rela. + template <typename Rel> + bool UnpackTypedRelocations(const std::vector<uint8_t>& packed); + + // Write ELF file changes. + void Flush(); + + // File descriptor opened on the shared object. + int fd_; + + // If set, pad rather than shrink .rel.dyn or .rela.dyn. Primarily for + // debugging, allows packing to be checked without affecting load addresses. + bool is_padding_relocations_; + + // Libelf handle, assigned by Load(). + Elf* elf_; + + // Sections that we manipulate, assigned by Load(). + Elf_Scn* relocations_section_; + Elf_Scn* dynamic_section_; + Elf_Scn* android_relocations_section_; + + // Relocation type found, assigned by Load(). + enum { NONE = 0, REL, RELA } relocations_type_; +}; + +} // namespace relocation_packer + +#endif // TOOLS_RELOCATION_PACKER_SRC_ELF_FILE_H_ diff --git a/tools/relocation_packer/src/elf_file_unittest.cc b/tools/relocation_packer/src/elf_file_unittest.cc new file mode 100644 index 0000000..37abd0d --- /dev/null +++ b/tools/relocation_packer/src/elf_file_unittest.cc @@ -0,0 +1,164 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "elf_file.h" + +#include <limits.h> +#include <stdio.h> +#include <unistd.h> +#include <string> +#include <vector> +#include "debug.h" +#include "elf_traits.h" +#include "testing/gtest/include/gtest/gtest.h" + +// Macro stringification. +// https://gcc.gnu.org/onlinedocs/cpp/Stringification.html +#define XSTR(S) STR(S) +#define STR(S) #S + +namespace { + +void GetDataFilePath(const char* name, std::string* path) { + std::string data_dir; + + const char* bindir = getenv("bindir"); + if (bindir) { + data_dir = std::string(bindir); + } else { + // Test data is in the gyp INTERMEDIATE_DIR subdirectory of the directory + // that contains the current binary. + char path[PATH_MAX]; + memset(path, 0, sizeof(path)); + ASSERT_NE(-1, readlink("/proc/self/exe", path, sizeof(path) - 1)); + + data_dir = std::string(path); + size_t pos = data_dir.rfind('/'); + ASSERT_NE(std::string::npos, pos); + + data_dir.erase(pos + 1); + data_dir += std::string(XSTR(INTERMEDIATE_DIR)); + } + + *path = data_dir + "/" + name; +} + +void OpenRelocsTestFile(const char* name, FILE** stream) { + std::string path; + GetDataFilePath(name, &path); + + FILE* testfile = fopen(path.c_str(), "rb"); + ASSERT_FALSE(testfile == NULL); + + FILE* temporary = tmpfile(); + ASSERT_FALSE(temporary == NULL); + + static const size_t buffer_size = 4096; + unsigned char buffer[buffer_size]; + + size_t bytes; + do { + bytes = fread(buffer, 1, sizeof(buffer), testfile); + ASSERT_EQ(bytes, fwrite(buffer, 1, bytes, temporary)); + } while (bytes > 0); + + ASSERT_EQ(0, fclose(testfile)); + ASSERT_EQ(0, fseek(temporary, 0, SEEK_SET)); + ASSERT_EQ(0, lseek(fileno(temporary), 0, SEEK_SET)); + + *stream = temporary; +} + +void OpenRelocsTestFiles(FILE** relocs_so, FILE** packed_relocs_so) { + const char* arch = NULL; + if (ELF::kMachine == EM_ARM) { + arch = "arm32"; + } else if (ELF::kMachine == EM_AARCH64) { + arch = "arm64"; + } + ASSERT_FALSE(arch == NULL); + + const std::string base = std::string("elf_file_unittest_relocs_") + arch; + const std::string relocs = base + ".so"; + const std::string packed_relocs = base + "_packed.so"; + + OpenRelocsTestFile(relocs.c_str(), relocs_so); + OpenRelocsTestFile(packed_relocs.c_str(), packed_relocs_so); +} + +void CloseRelocsTestFile(FILE* temporary) { + fclose(temporary); +} + +void CloseRelocsTestFiles(FILE* relocs_so, FILE* packed_relocs_so) { + CloseRelocsTestFile(relocs_so); + CloseRelocsTestFile(packed_relocs_so); +} + +void CheckFileContentsEqual(FILE* first, FILE* second) { + ASSERT_EQ(0, fseek(first, 0, SEEK_SET)); + ASSERT_EQ(0, fseek(second, 0, SEEK_SET)); + + static const size_t buffer_size = 4096; + unsigned char first_buffer[buffer_size]; + unsigned char second_buffer[buffer_size]; + + do { + size_t first_read = fread(first_buffer, 1, sizeof(first_buffer), first); + size_t second_read = fread(second_buffer, 1, sizeof(second_buffer), second); + + EXPECT_EQ(first_read, second_read); + EXPECT_EQ(0, memcmp(first_buffer, second_buffer, first_read)); + } while (!feof(first) && !feof(second)); + + EXPECT_TRUE(feof(first) && feof(second)); +} + +} // namespace + +namespace relocation_packer { + +TEST(ElfFile, PackRelocations) { + ASSERT_NE(EV_NONE, elf_version(EV_CURRENT)); + + FILE* relocs_so = NULL; + FILE* packed_relocs_so = NULL; + OpenRelocsTestFiles(&relocs_so, &packed_relocs_so); + if (HasFatalFailure()) + return; + + ElfFile elf_file(fileno(relocs_so)); + + // Ensure unpacking fails (not packed). + EXPECT_FALSE(elf_file.UnpackRelocations()); + + // Pack relocations, and check files are now identical. + EXPECT_TRUE(elf_file.PackRelocations()); + CheckFileContentsEqual(relocs_so, packed_relocs_so); + + CloseRelocsTestFiles(relocs_so, packed_relocs_so); +} + +TEST(ElfFile, UnpackRelocations) { + ASSERT_NE(EV_NONE, elf_version(EV_CURRENT)); + + FILE* relocs_so = NULL; + FILE* packed_relocs_so = NULL; + OpenRelocsTestFiles(&relocs_so, &packed_relocs_so); + if (HasFatalFailure()) + return; + + ElfFile elf_file(fileno(packed_relocs_so)); + + // Ensure packing fails (already packed). + EXPECT_FALSE(elf_file.PackRelocations()); + + // Unpack golden relocations, and check files are now identical. + EXPECT_TRUE(elf_file.UnpackRelocations()); + CheckFileContentsEqual(packed_relocs_so, relocs_so); + + CloseRelocsTestFiles(relocs_so, packed_relocs_so); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/elf_traits.h b/tools/relocation_packer/src/elf_traits.h new file mode 100644 index 0000000..f099bab --- /dev/null +++ b/tools/relocation_packer/src/elf_traits.h @@ -0,0 +1,105 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Target-specific ELF type traits. + +#ifndef TOOLS_RELOCATION_PACKER_SRC_ELF_TRAITS_H_ +#define TOOLS_RELOCATION_PACKER_SRC_ELF_TRAITS_H_ + +#include "elf.h" +#include "libelf.h" + +// The TARGET_ macro controls which Elf types we expect and handle. +// Either TARGET_ARM or TARGET_ARM64 must be defined, but not both. + +#if !defined(TARGET_ARM) && !defined(TARGET_ARM64) +# error "Unsupported target, define one of TARGET_ARM or TARGET_ARM64" +#elif defined(TARGET_ARM) && defined(TARGET_ARM64) +# error "Define one of TARGET_ARM or TARGET_ARM64, but not both" +#endif + +// TODO(simonb): Eliminate these once AARCH64 appears reliably in elf.h. +#ifndef EM_AARCH64 +#define EM_AARCH64 183 +#endif +#ifndef R_AARCH64_RELATIVE +#define R_AARCH64_RELATIVE 1027 +#endif +#ifndef R_AARCH64_NONE +#define R_AARCH64_NONE 0 +#endif + +// ELF is a traits structure used to provide convenient aliases for +// 32/64 bit Elf types and functions, depending on the target specified. + +#if defined(TARGET_ARM) +struct ELF { + typedef Elf32_Addr Addr; + typedef Elf32_Dyn Dyn; + typedef Elf32_Ehdr Ehdr; + typedef Elf32_Off Off; + typedef Elf32_Phdr Phdr; + typedef Elf32_Rel Rel; + typedef Elf32_Rela Rela; + typedef Elf32_Shdr Shdr; + typedef Elf32_Sword Sword; + typedef Elf32_Sxword Sxword; + typedef Elf32_Sym Sym; + typedef Elf32_Word Word; + typedef Elf32_Xword Xword; + + static inline Ehdr* getehdr(Elf* elf) { return elf32_getehdr(elf); } + static inline Phdr* getphdr(Elf* elf) { return elf32_getphdr(elf); } + static inline Shdr* getshdr(Elf_Scn* scn) { return elf32_getshdr(scn); } + + enum { kMachine = EM_ARM }; + enum { kFileClass = ELFCLASS32 }; + enum { kRelativeRelocationCode = R_ARM_RELATIVE }; + enum { kNoRelocationCode = R_ARM_NONE }; + enum { kGnuStackSegmentAlignment = 0 }; + + static inline const char* Machine() { return "ARM"; } + +# define ELF_R_SYM(val) ELF32_R_SYM(val) +# define ELF_R_TYPE(val) ELF32_R_TYPE(val) +# define ELF_R_INFO(sym, type) ELF32_R_INFO(sym, type) +# define ELF_ST_TYPE(val) ELF32_ST_TYPE(val) +}; + +#elif defined(TARGET_ARM64) +struct ELF { + typedef Elf64_Addr Addr; + typedef Elf64_Dyn Dyn; + typedef Elf64_Ehdr Ehdr; + typedef Elf64_Off Off; + typedef Elf64_Phdr Phdr; + typedef Elf64_Rel Rel; + typedef Elf64_Rela Rela; + typedef Elf64_Shdr Shdr; + typedef Elf64_Sword Sword; + typedef Elf64_Sxword Sxword; + typedef Elf64_Sym Sym; + typedef Elf64_Word Word; + typedef Elf64_Xword Xword; + + static inline Ehdr* getehdr(Elf* elf) { return elf64_getehdr(elf); } + static inline Phdr* getphdr(Elf* elf) { return elf64_getphdr(elf); } + static inline Shdr* getshdr(Elf_Scn* scn) { return elf64_getshdr(scn); } + + enum { kMachine = EM_AARCH64 }; + enum { kFileClass = ELFCLASS64 }; + enum { kRelativeRelocationCode = R_AARCH64_RELATIVE }; + enum { kNoRelocationCode = R_AARCH64_NONE }; + enum { kGnuStackSegmentAlignment = 16 }; + + static inline const char* Machine() { return "ARM64"; } + +# define ELF_R_SYM(val) ELF64_R_SYM(val) +# define ELF_R_TYPE(val) ELF64_R_TYPE(val) +# define ELF_R_INFO(sym, type) ELF64_R_INFO(sym, type) +# define ELF_ST_TYPE(val) ELF64_ST_TYPE(val) +}; +#endif + +#endif // TOOLS_RELOCATION_PACKER_SRC_ELF_TRAITS_H_ diff --git a/tools/relocation_packer/src/leb128.cc b/tools/relocation_packer/src/leb128.cc new file mode 100644 index 0000000..b48739c --- /dev/null +++ b/tools/relocation_packer/src/leb128.cc @@ -0,0 +1,69 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "leb128.h" + +#include <stdint.h> +#include <vector> + +#include "elf_traits.h" + +namespace relocation_packer { + +// Empty constructor and destructor to silence chromium-style. +Leb128Encoder::Leb128Encoder() { } +Leb128Encoder::~Leb128Encoder() { } + +// Add a single value to the encoding. Values are encoded with variable +// length. The least significant 7 bits of each byte hold 7 bits of data, +// and the most significant bit is set on each byte except the last. +void Leb128Encoder::Enqueue(ELF::Xword value) { + do { + const uint8_t byte = value & 127; + value >>= 7; + encoding_.push_back((value ? 128 : 0) | byte); + } while (value); +} + +// Add a vector of values to the encoding. +void Leb128Encoder::EnqueueAll(const std::vector<ELF::Xword>& values) { + for (size_t i = 0; i < values.size(); ++i) + Enqueue(values[i]); +} + +// Create a new decoder for the given encoded stream. +Leb128Decoder::Leb128Decoder(const std::vector<uint8_t>& encoding) { + encoding_ = encoding; + cursor_ = 0; +} + +// Empty destructor to silence chromium-style. +Leb128Decoder::~Leb128Decoder() { } + +// Decode and retrieve a single value from the encoding. Read forwards until +// a byte without its most significant bit is found, then read the 7 bit +// fields of the bytes spanned to re-form the value. +ELF::Xword Leb128Decoder::Dequeue() { + ELF::Xword value = 0; + + size_t shift = 0; + uint8_t byte; + + // Loop until we reach a byte with its high order bit clear. + do { + byte = encoding_[cursor_++]; + value |= static_cast<ELF::Xword>(byte & 127) << shift; + shift += 7; + } while (byte & 128); + + return value; +} + +// Decode and retrieve all remaining values from the encoding. +void Leb128Decoder::DequeueAll(std::vector<ELF::Xword>* values) { + while (cursor_ < encoding_.size()) + values->push_back(Dequeue()); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/leb128.h b/tools/relocation_packer/src/leb128.h new file mode 100644 index 0000000..6cc2d7c --- /dev/null +++ b/tools/relocation_packer/src/leb128.h @@ -0,0 +1,74 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// LEB128 encoder and decoder for packed relative relocations. +// +// Run-length encoded relative relocations consist of a large number +// of pairs of relatively small positive integer values. Encoding these as +// LEB128 saves space. +// +// For more on LEB128 see http://en.wikipedia.org/wiki/LEB128. + +#ifndef TOOLS_RELOCATION_PACKER_SRC_LEB128_H_ +#define TOOLS_RELOCATION_PACKER_SRC_LEB128_H_ + +#include <stdint.h> +#include <vector> + +#include "elf_traits.h" + +namespace relocation_packer { + +// Encode packed words as a LEB128 byte stream. +class Leb128Encoder { + public: + // Explicit (but empty) constructor and destructor, for chromium-style. + Leb128Encoder(); + ~Leb128Encoder(); + + // Add a value to the encoding stream. + // |value| is the unsigned int to add. + void Enqueue(ELF::Xword value); + + // Add a vector of values to the encoding stream. + // |values| is the vector of unsigned ints to add. + void EnqueueAll(const std::vector<ELF::Xword>& values); + + // Retrieve the encoded representation of the values. + // |encoding| is the returned vector of encoded data. + void GetEncoding(std::vector<uint8_t>* encoding) { *encoding = encoding_; } + + private: + // Growable vector holding the encoded LEB128 stream. + std::vector<uint8_t> encoding_; +}; + +// Decode a LEB128 byte stream to produce packed words. +class Leb128Decoder { + public: + // Create a new decoder for the given encoded stream. + // |encoding| is the vector of encoded data. + explicit Leb128Decoder(const std::vector<uint8_t>& encoding); + + // Explicit (but empty) destructor, for chromium-style. + ~Leb128Decoder(); + + // Retrieve the next value from the encoded stream. + ELF::Xword Dequeue(); + + // Retrieve all remaining values from the encoded stream. + // |values| is the vector of decoded data. + void DequeueAll(std::vector<ELF::Xword>* values); + + private: + // Encoded LEB128 stream. + std::vector<uint8_t> encoding_; + + // Cursor indicating the current stream retrieval point. + size_t cursor_; +}; + +} // namespace relocation_packer + +#endif // TOOLS_RELOCATION_PACKER_SRC_LEB128_H_ diff --git a/tools/relocation_packer/src/leb128_unittest.cc b/tools/relocation_packer/src/leb128_unittest.cc new file mode 100644 index 0000000..bd607b7 --- /dev/null +++ b/tools/relocation_packer/src/leb128_unittest.cc @@ -0,0 +1,111 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "leb128.h" + +#include <vector> +#include "testing/gtest/include/gtest/gtest.h" + +namespace relocation_packer { + +TEST(Leb128, Encoder) { + std::vector<ELF::Xword> values; + values.push_back(624485); + values.push_back(0); + values.push_back(1); + values.push_back(127); + values.push_back(128); + + Leb128Encoder encoder; + encoder.EnqueueAll(values); + + encoder.Enqueue(4294967295); + encoder.Enqueue(18446744073709551615ul); + + std::vector<uint8_t> encoding; + encoder.GetEncoding(&encoding); + + EXPECT_EQ(23, encoding.size()); + // 624485 + EXPECT_EQ(0xe5, encoding[0]); + EXPECT_EQ(0x8e, encoding[1]); + EXPECT_EQ(0x26, encoding[2]); + // 0 + EXPECT_EQ(0x00, encoding[3]); + // 1 + EXPECT_EQ(0x01, encoding[4]); + // 127 + EXPECT_EQ(0x7f, encoding[5]); + // 128 + EXPECT_EQ(0x80, encoding[6]); + EXPECT_EQ(0x01, encoding[7]); + // 4294967295 + EXPECT_EQ(0xff, encoding[8]); + EXPECT_EQ(0xff, encoding[9]); + EXPECT_EQ(0xff, encoding[10]); + EXPECT_EQ(0xff, encoding[11]); + EXPECT_EQ(0x0f, encoding[12]); + // 18446744073709551615 + EXPECT_EQ(0xff, encoding[13]); + EXPECT_EQ(0xff, encoding[14]); + EXPECT_EQ(0xff, encoding[15]); + EXPECT_EQ(0xff, encoding[16]); + EXPECT_EQ(0xff, encoding[17]); + EXPECT_EQ(0xff, encoding[18]); + EXPECT_EQ(0xff, encoding[19]); + EXPECT_EQ(0xff, encoding[20]); + EXPECT_EQ(0xff, encoding[21]); + EXPECT_EQ(0x01, encoding[22]); +} + +TEST(Leb128, Decoder) { + std::vector<uint8_t> encoding; + // 624485 + encoding.push_back(0xe5); + encoding.push_back(0x8e); + encoding.push_back(0x26); + // 0 + encoding.push_back(0x00); + // 1 + encoding.push_back(0x01); + // 127 + encoding.push_back(0x7f); + // 128 + encoding.push_back(0x80); + encoding.push_back(0x01); + // 4294967295 + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0x0f); + // 18446744073709551615 + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0x01); + + Leb128Decoder decoder(encoding); + + EXPECT_EQ(624485, decoder.Dequeue()); + + std::vector<ELF::Xword> dequeued; + decoder.DequeueAll(&dequeued); + + EXPECT_EQ(6, dequeued.size()); + EXPECT_EQ(0, dequeued[0]); + EXPECT_EQ(1, dequeued[1]); + EXPECT_EQ(127, dequeued[2]); + EXPECT_EQ(128, dequeued[3]); + EXPECT_EQ(4294967295, dequeued[4]); + EXPECT_EQ(18446744073709551615ul, dequeued[5]); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/main.cc b/tools/relocation_packer/src/main.cc new file mode 100644 index 0000000..28f5b04 --- /dev/null +++ b/tools/relocation_packer/src/main.cc @@ -0,0 +1,175 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Tool to pack and unpack relative relocations in a shared library. +// +// Packing removes relative relocations from .rel.dyn and writes them +// in a more compact form to .android.rel.dyn. Unpacking does the reverse. +// +// Invoke with -v to trace actions taken when packing or unpacking. +// Invoke with -p to pad removed relocations with R_*_NONE. Suppresses +// shrinking of .rel.dyn. +// See PrintUsage() below for full usage details. +// +// NOTE: Breaks with libelf 0.152, which is buggy. libelf 0.158 works. + +#include <errno.h> +#include <fcntl.h> +#include <getopt.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/types.h> +#include <unistd.h> +#include <string> + +#include "debug.h" +#include "elf_file.h" +#include "libelf.h" + +namespace { + +void PrintUsage(const char* argv0) { + std::string temporary = argv0; + const size_t last_slash = temporary.find_last_of("/"); + if (last_slash != temporary.npos) { + temporary.erase(0, last_slash + 1); + } + const char* basename = temporary.c_str(); + + printf( + "Usage: %s [-u] [-v] [-p] file\n\n" + "Pack or unpack relative relocations in a shared library.\n\n" + " -u, --unpack unpack previously packed relative relocations\n" + " -v, --verbose trace object file modifications (for debugging)\n" + " -p, --pad do not shrink relocations, but pad (for debugging)\n\n", + basename); + + if (ELF::kMachine == EM_ARM) { + printf( + "Extracts relative relocations from the .rel.dyn section, packs them\n" + "into a more compact format, and stores the packed relocations in\n" + ".android.rel.dyn. Expands .android.rel.dyn to hold the packed\n" + "data, and shrinks .rel.dyn by the amount of unpacked data removed\n" + "from it.\n\n" + "Before being packed, a shared library needs to be prepared by adding\n" + "a null .android.rel.dyn section.\n\n" + "To pack relocations in a shared library:\n\n" + " echo -n 'NULL' >/tmp/small\n" + " arm-linux-androideabi-objcopy \\\n" + " --add-section .android.rel.dyn=/tmp/small \\\n" + " libchrome.<version>.so\n" + " rm /tmp/small\n" + " %s libchrome.<version>.so\n\n" + "To unpack and restore the shared library to its original state:\n\n" + " %s -u libchrome.<version>.so\n" + " arm-linux-androideabi-objcopy \\\n" + " --remove-section=.android.rel.dyn libchrome.<version>.so\n\n", + basename, basename); + } else if (ELF::kMachine == EM_AARCH64) { + printf( + "Extracts relative relocations from the .rela.dyn section, packs them\n" + "into a more compact format, and stores the packed relocations in\n" + ".android.rela.dyn. Expands .android.rela.dyn to hold the packed\n" + "data, and shrinks .rela.dyn by the amount of unpacked data removed\n" + "from it.\n\n" + "Before being packed, a shared library needs to be prepared by adding\n" + "a null .android.rela.dyn section.\n\n" + "To pack relocations in a shared library:\n\n" + " echo -n 'NULL' >/tmp/small\n" + " aarch64-linux-android-objcopy \\\n" + " --add-section .android.rela.dyn=/tmp/small \\\n" + " libchrome.<version>.so\n" + " rm /tmp/small\n" + " %s libchrome.<version>.so\n\n" + "To unpack and restore the shared library to its original state:\n\n" + " %s -u libchrome.<version>.so\n" + " aarch64-linux-android-objcopy \\\n" + " --remove-section=.android.rela.dyn libchrome.<version>.so\n\n", + basename, basename); + } else { + NOTREACHED(); + } + + printf( + "Debug sections are not handled, so packing should not be used on\n" + "shared libraries compiled for debugging or otherwise unstripped.\n"); +} + +} // namespace + +int main(int argc, char* argv[]) { + bool is_unpacking = false; + bool is_verbose = false; + bool is_padding = false; + + static const option options[] = { + {"unpack", 0, 0, 'u'}, {"verbose", 0, 0, 'v'}, {"pad", 0, 0, 'p'}, + {"help", 0, 0, 'h'}, {NULL, 0, 0, 0} + }; + bool has_options = true; + while (has_options) { + int c = getopt_long(argc, argv, "uvph", options, NULL); + switch (c) { + case 'u': + is_unpacking = true; + break; + case 'v': + is_verbose = true; + break; + case 'p': + is_padding = true; + break; + case 'h': + PrintUsage(argv[0]); + return 0; + case '?': + LOG(INFO) << "Try '" << argv[0] << " --help' for more information."; + return 1; + case -1: + has_options = false; + break; + default: + NOTREACHED(); + return 1; + } + } + if (optind != argc - 1) { + LOG(INFO) << "Try '" << argv[0] << " --help' for more information."; + return 1; + } + + if (elf_version(EV_CURRENT) == EV_NONE) { + LOG(WARNING) << "Elf Library is out of date!"; + } + + LOG(INFO) << "Configured for " << ELF::Machine(); + + const char* file = argv[argc - 1]; + const int fd = open(file, O_RDWR); + if (fd == -1) { + LOG(ERROR) << file << ": " << strerror(errno); + return 1; + } + + if (is_verbose) + relocation_packer::Logger::SetVerbose(1); + + relocation_packer::ElfFile elf_file(fd); + elf_file.SetPadding(is_padding); + + bool status; + if (is_unpacking) + status = elf_file.UnpackRelocations(); + else + status = elf_file.PackRelocations(); + + close(fd); + + if (!status) { + LOG(ERROR) << file << ": failed to pack/unpack file"; + return 1; + } + + return 0; +} diff --git a/tools/relocation_packer/src/packer.cc b/tools/relocation_packer/src/packer.cc new file mode 100644 index 0000000..29bec1e --- /dev/null +++ b/tools/relocation_packer/src/packer.cc @@ -0,0 +1,124 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "packer.h" + +#include <vector> + +#include "debug.h" +#include "delta_encoder.h" +#include "elf_traits.h" +#include "leb128.h" +#include "run_length_encoder.h" +#include "sleb128.h" + +namespace relocation_packer { + +// Pack relative relocations into a run-length encoded packed +// representation. +void RelocationPacker::PackRelativeRelocations( + const std::vector<ELF::Rel>& relocations, + std::vector<uint8_t>* packed) { + // Run-length encode. + std::vector<ELF::Xword> packed_words; + RelocationRunLengthCodec codec; + codec.Encode(relocations, &packed_words); + + // If insufficient data to run-length encode, do nothing. + if (packed_words.empty()) + return; + + // LEB128 encode, with "APR1" prefix. + Leb128Encoder encoder; + encoder.Enqueue('A'); + encoder.Enqueue('P'); + encoder.Enqueue('R'); + encoder.Enqueue('1'); + encoder.EnqueueAll(packed_words); + + encoder.GetEncoding(packed); + + // Pad packed to a whole number of words. This padding will decode as + // LEB128 zeroes. Run-length decoding ignores it because encoding + // embeds the pairs count in the stream itself. + while (packed->size() % sizeof(ELF::Word)) + packed->push_back(0); +} + +// Unpack relative relocations from a run-length encoded packed +// representation. +void RelocationPacker::UnpackRelativeRelocations( + const std::vector<uint8_t>& packed, + std::vector<ELF::Rel>* relocations) { + // LEB128 decode, after checking and stripping "APR1" prefix. + std::vector<ELF::Xword> packed_words; + Leb128Decoder decoder(packed); + CHECK(decoder.Dequeue() == 'A' && + decoder.Dequeue() == 'P' && + decoder.Dequeue() == 'R' && + decoder.Dequeue() == '1'); + decoder.DequeueAll(&packed_words); + + // Run-length decode. + RelocationRunLengthCodec codec; + codec.Decode(packed_words, relocations); +} + +// Pack relative relocations with addends into a delta encoded packed +// representation. +void RelocationPacker::PackRelativeRelocations( + const std::vector<ELF::Rela>& relocations, + std::vector<uint8_t>* packed) { + // Delta encode. + std::vector<ELF::Sxword> packed_words; + RelocationDeltaCodec codec; + codec.Encode(relocations, &packed_words); + + // If insufficient data to delta encode, do nothing. + if (packed_words.empty()) + return; + + // Signed LEB128 encode, with "APA1" prefix. ASCII does not encode as + // itself under signed LEB128, so we have to treat it specially. + Sleb128Encoder encoder; + encoder.EnqueueAll(packed_words); + std::vector<uint8_t> encoded; + encoder.GetEncoding(&encoded); + + packed->push_back('A'); + packed->push_back('P'); + packed->push_back('A'); + packed->push_back('1'); + packed->insert(packed->end(), encoded.begin(), encoded.end()); + + // Pad packed to a whole number of words. This padding will decode as + // signed LEB128 zeroes. Delta decoding ignores it because encoding + // embeds the pairs count in the stream itself. + while (packed->size() % sizeof(ELF::Word)) + packed->push_back(0); +} + +// Unpack relative relocations with addends from a delta encoded +// packed representation. +void RelocationPacker::UnpackRelativeRelocations( + const std::vector<uint8_t>& packed, + std::vector<ELF::Rela>* relocations) { + // Check "APA1" prefix. + CHECK(packed.at(0) == 'A' && + packed.at(1) == 'P' && + packed.at(2) == 'A' && + packed.at(3) == '1'); + + // Signed LEB128 decode, after stripping "APA1" prefix. + std::vector<ELF::Sxword> packed_words; + std::vector<uint8_t> stripped(packed.begin() + 4, packed.end()); + Sleb128Decoder decoder(stripped); + decoder.DequeueAll(&packed_words); + + // Delta decode. + RelocationDeltaCodec codec; + codec.Decode(packed_words, relocations); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/packer.h b/tools/relocation_packer/src/packer.h new file mode 100644 index 0000000..db09ce8 --- /dev/null +++ b/tools/relocation_packer/src/packer.h @@ -0,0 +1,78 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Pack relative relocations into a more compact form. +// +// +// For relative relocations without addends (32 bit platforms) +// ----------------------------------------------------------- +// +// Applies two packing strategies. The first is run-length encoding, which +// turns a large set of relative relocations into a much smaller set +// of delta-count pairs, prefixed with a two-word header comprising the +// count of pairs and the initial relocation offset. The second is LEB128 +// encoding, which compresses the result of run-length encoding. +// +// Once packed, data is prefixed by an identifier that allows for any later +// versioning of packing strategies. +// +// A complete packed stream of relocations without addends might look +// something like: +// +// "APR1" pairs init_offset count1 delta1 count2 delta2 ... +// 41505231 f2b003 b08ac716 e001 04 01 10 ... +// +// +// For relative relocations with addends (64 bit platforms) +// -------------------------------------------------------- +// +// Applies two packing strategies. The first is delta encoding, which +// turns a large set of relative relocations into a smaller set +// of offset and addend delta pairs, prefixed with a header indicating the +// count of pairs. The second is signed LEB128 encoding, which compacts +// the result of delta encoding. +// +// Once packed, data is prefixed by an identifier that allows for any later +// versioning of packing strategies. +// +// A complete packed stream might look something like: +// +// "APA1" pairs offset_d1 addend_d1 offset_d2 addend_d2 ... +// 41505232 f2b018 04 28 08 9f01 ... + +#ifndef TOOLS_RELOCATION_PACKER_SRC_PACKER_H_ +#define TOOLS_RELOCATION_PACKER_SRC_PACKER_H_ + +#include <stdint.h> +#include <vector> + +#include "elf.h" +#include "elf_traits.h" + +namespace relocation_packer { + +// A RelocationPacker packs vectors of relative relocations into more +// compact forms, and unpacks them to reproduce the pre-packed data. +class RelocationPacker { + public: + // Pack relative relocations into a more compact form. + // |relocations| is a vector of relative relocation structs. + // |packed| is the vector of packed bytes into which relocations are packed. + static void PackRelativeRelocations(const std::vector<ELF::Rel>& relocations, + std::vector<uint8_t>* packed); + static void PackRelativeRelocations(const std::vector<ELF::Rela>& relocations, + std::vector<uint8_t>* packed); + + // Unpack relative relocations from their more compact form. + // |packed| is the vector of packed relocations. + // |relocations| is a vector of unpacked relative relocation structs. + static void UnpackRelativeRelocations(const std::vector<uint8_t>& packed, + std::vector<ELF::Rel>* relocations); + static void UnpackRelativeRelocations(const std::vector<uint8_t>& packed, + std::vector<ELF::Rela>* relocations); +}; + +} // namespace relocation_packer + +#endif // TOOLS_RELOCATION_PACKER_SRC_PACKER_H_ diff --git a/tools/relocation_packer/src/packer_unittest.cc b/tools/relocation_packer/src/packer_unittest.cc new file mode 100644 index 0000000..de5be79 --- /dev/null +++ b/tools/relocation_packer/src/packer_unittest.cc @@ -0,0 +1,250 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "packer.h" + +#include <vector> +#include "elf.h" +#include "elf_traits.h" +#include "testing/gtest/include/gtest/gtest.h" + +namespace { + +void AddRelocation(ELF::Addr addr, std::vector<ELF::Rel>* relocations) { + ELF::Rel relocation; + relocation.r_offset = addr; + relocation.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode); + relocations->push_back(relocation); +} + +bool CheckRelocation(ELF::Addr addr, const ELF::Rel& relocation) { + return relocation.r_offset == addr && + ELF_R_SYM(relocation.r_info) == 0 && + ELF_R_TYPE(relocation.r_info) == ELF::kRelativeRelocationCode; +} + +void AddRelocation(ELF::Addr addr, + ELF::Sxword addend, + std::vector<ELF::Rela>* relocations) { + ELF::Rela relocation; + relocation.r_offset = addr; + relocation.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode); + relocation.r_addend = addend; + relocations->push_back(relocation); +} + +bool CheckRelocation(ELF::Addr addr, + ELF::Sxword addend, + const ELF::Rela& relocation) { + return relocation.r_offset == addr && + ELF_R_SYM(relocation.r_info) == 0 && + ELF_R_TYPE(relocation.r_info) == ELF::kRelativeRelocationCode && + relocation.r_addend == addend; +} + +} // namespace + +namespace relocation_packer { + +TEST(Packer, PackRel) { + std::vector<ELF::Rel> relocations; + std::vector<uint8_t> packed; + + RelocationPacker packer; + + // Initial relocation. + AddRelocation(0xd1ce0000, &relocations); + // Two more relocations, 4 byte deltas. + AddRelocation(0xd1ce0004, &relocations); + AddRelocation(0xd1ce0008, &relocations); + // Three more relocations, 8 byte deltas. + AddRelocation(0xd1ce0010, &relocations); + AddRelocation(0xd1ce0018, &relocations); + AddRelocation(0xd1ce0020, &relocations); + + packed.clear(); + packer.PackRelativeRelocations(relocations, &packed); + + EXPECT_EQ(16, packed.size()); + // Identifier. + EXPECT_EQ('A', packed[0]); + EXPECT_EQ('P', packed[1]); + EXPECT_EQ('R', packed[2]); + EXPECT_EQ('1', packed[3]); + // Count-delta pairs count. + EXPECT_EQ(2, packed[4]); + // 0xd1ce0000 + EXPECT_EQ(128, packed[5]); + EXPECT_EQ(128, packed[6]); + EXPECT_EQ(184, packed[7]); + EXPECT_EQ(142, packed[8]); + EXPECT_EQ(13, packed[9]); + // Run of two relocations, 4 byte deltas. + EXPECT_EQ(2, packed[10]); + EXPECT_EQ(4, packed[11]); + // Run of three relocations, 8 byte deltas. + EXPECT_EQ(3, packed[12]); + EXPECT_EQ(8, packed[13]); + // Padding. + EXPECT_EQ(0, packed[14]); + EXPECT_EQ(0, packed[15]); +} + +TEST(Packer, UnpackRel) { + std::vector<uint8_t> packed; + std::vector<ELF::Rel> relocations; + + RelocationPacker packer; + + // Identifier. + packed.push_back('A'); + packed.push_back('P'); + packed.push_back('R'); + packed.push_back('1'); + // Count-delta pairs count. + packed.push_back(2); + // 0xd1ce0000 + packed.push_back(128); + packed.push_back(128); + packed.push_back(184); + packed.push_back(142); + packed.push_back(13); + // Run of two relocations, 4 byte deltas. + packed.push_back(2); + packed.push_back(4); + // Run of three relocations, 8 byte deltas. + packed.push_back(3); + packed.push_back(8); + // Padding. + packed.push_back(0); + packed.push_back(0); + + relocations.clear(); + packer.UnpackRelativeRelocations(packed, &relocations); + + EXPECT_EQ(6, relocations.size()); + // Initial relocation. + EXPECT_TRUE(CheckRelocation(0xd1ce0000, relocations[0])); + // Two relocations, 4 byte deltas. + EXPECT_TRUE(CheckRelocation(0xd1ce0004, relocations[1])); + EXPECT_TRUE(CheckRelocation(0xd1ce0008, relocations[2])); + // Three relocations, 8 byte deltas. + EXPECT_TRUE(CheckRelocation(0xd1ce0010, relocations[3])); + EXPECT_TRUE(CheckRelocation(0xd1ce0018, relocations[4])); + EXPECT_TRUE(CheckRelocation(0xd1ce0020, relocations[5])); +} + +TEST(Packer, PackRela) { + std::vector<ELF::Rela> relocations; + std::vector<uint8_t> packed; + + RelocationPacker packer; + + // Initial relocation. + AddRelocation(0xd1ce0000, 10000, &relocations); + // Two more relocations, 4 byte offset deltas, 12 byte addend deltas. + AddRelocation(0xd1ce0004, 10012, &relocations); + AddRelocation(0xd1ce0008, 10024, &relocations); + // Three more relocations, 8 byte deltas, -24 byte addend deltas. + AddRelocation(0xd1ce0010, 10000, &relocations); + AddRelocation(0xd1ce0018, 9976, &relocations); + AddRelocation(0xd1ce0020, 9952, &relocations); + + packed.clear(); + packer.PackRelativeRelocations(relocations, &packed); + + EXPECT_EQ(24, packed.size()); + // Identifier. + EXPECT_EQ('A', packed[0]); + EXPECT_EQ('P', packed[1]); + EXPECT_EQ('A', packed[2]); + EXPECT_EQ('1', packed[3]); + // Delta pairs count. + EXPECT_EQ(6, packed[4]); + // 0xd1ce0000 + EXPECT_EQ(128, packed[5]); + EXPECT_EQ(128, packed[6]); + EXPECT_EQ(184, packed[7]); + EXPECT_EQ(142, packed[8]); + EXPECT_EQ(13, packed[9]); + // 10000 + EXPECT_EQ(144, packed[10]); + EXPECT_EQ(206, packed[11]); + EXPECT_EQ(0, packed[12]); + // 4, 12 + EXPECT_EQ(4, packed[13]); + EXPECT_EQ(12, packed[14]); + // 4, 12 + EXPECT_EQ(4, packed[15]); + EXPECT_EQ(12, packed[16]); + // 8, -24 + EXPECT_EQ(8, packed[17]); + EXPECT_EQ(104, packed[18]); + // 8, -24 + EXPECT_EQ(8, packed[19]); + EXPECT_EQ(104, packed[20]); + // 8, -24 + EXPECT_EQ(8, packed[21]); + EXPECT_EQ(104, packed[22]); + // Padding. + EXPECT_EQ(0, packed[23]); +} + +TEST(Packer, UnpackRela) { + std::vector<uint8_t> packed; + std::vector<ELF::Rela> relocations; + + RelocationPacker packer; + + // Identifier. + packed.push_back('A'); + packed.push_back('P'); + packed.push_back('A'); + packed.push_back('1'); + // Delta pairs count. + packed.push_back(6); + // 0xd1ce0000 + packed.push_back(128); + packed.push_back(128); + packed.push_back(184); + packed.push_back(142); + packed.push_back(13); + // 10000 + packed.push_back(144); + packed.push_back(206); + packed.push_back(0); + // 4, 12 + packed.push_back(4); + packed.push_back(12); + // 4, 12 + packed.push_back(4); + packed.push_back(12); + // 8, -24 + packed.push_back(8); + packed.push_back(104); + // 8, -24 + packed.push_back(8); + packed.push_back(104); + // 8, -24 + packed.push_back(8); + packed.push_back(104); + // Padding. + packed.push_back(0); + + relocations.clear(); + packer.UnpackRelativeRelocations(packed, &relocations); + + EXPECT_EQ(6, relocations.size()); + // Initial relocation. + EXPECT_TRUE(CheckRelocation(0xd1ce0000, 10000, relocations[0])); + // Two more relocations, 4 byte offset deltas, 12 byte addend deltas. + EXPECT_TRUE(CheckRelocation(0xd1ce0004, 10012, relocations[1])); + EXPECT_TRUE(CheckRelocation(0xd1ce0008, 10024, relocations[2])); + // Three more relocations, 8 byte offset deltas, -24 byte addend deltas. + EXPECT_TRUE(CheckRelocation(0xd1ce0010, 10000, relocations[3])); + EXPECT_TRUE(CheckRelocation(0xd1ce0018, 9976, relocations[4])); + EXPECT_TRUE(CheckRelocation(0xd1ce0020, 9952, relocations[5])); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/run_all_unittests.cc b/tools/relocation_packer/src/run_all_unittests.cc new file mode 100644 index 0000000..4122be1 --- /dev/null +++ b/tools/relocation_packer/src/run_all_unittests.cc @@ -0,0 +1,10 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "testing/gtest/include/gtest/gtest.h" + +int main(int argc, char** argv) { + testing::InitGoogleTest(&argc, argv); + return RUN_ALL_TESTS(); +} diff --git a/tools/relocation_packer/src/run_length_encoder.cc b/tools/relocation_packer/src/run_length_encoder.cc new file mode 100644 index 0000000..2f2e1c3 --- /dev/null +++ b/tools/relocation_packer/src/run_length_encoder.cc @@ -0,0 +1,144 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "run_length_encoder.h" + +#include <vector> + +#include "debug.h" +#include "elf_traits.h" + +namespace relocation_packer { + +namespace { + +// Generate a vector of deltas between the r_offset fields of adjacent +// relative relocations. +void GetDeltas(const std::vector<ELF::Rel>& relocations, + std::vector<ELF::Addr>* deltas) { + CHECK(relocations.size() >= 2); + + for (size_t i = 0; i < relocations.size() - 1; ++i) { + const ELF::Rel* first = &relocations[i]; + CHECK(ELF_R_TYPE(first->r_info) == ELF::kRelativeRelocationCode); + + const ELF::Rel* second = &relocations[i + 1]; + CHECK(ELF_R_TYPE(second->r_info) == ELF::kRelativeRelocationCode); + + // Requires that offsets are 'strictly increasing'. The packing + // algorithm fails if this does not hold. + CHECK(second->r_offset > first->r_offset); + deltas->push_back(second->r_offset - first->r_offset); + } +} + +// Condense a set of r_offset deltas into a run-length encoded packing. +// Represented as count-delta pairs, where count is the run length and +// delta the common difference between adjacent r_offsets. +void Condense(const std::vector<ELF::Addr>& deltas, + std::vector<ELF::Xword>* packed) { + CHECK(!deltas.empty()); + size_t count = 0; + ELF::Addr current = deltas[0]; + + // Identify spans of identically valued deltas. + for (size_t i = 0; i < deltas.size(); ++i) { + const ELF::Addr delta = deltas[i]; + if (delta == current) { + count++; + } else { + // We reached the end of a span of identically valued deltas. + packed->push_back(count); + packed->push_back(current); + current = delta; + count = 1; + } + } + + // Write the final span. + packed->push_back(count); + packed->push_back(current); +} + +// Uncondense a set of r_offset deltas from a run-length encoded packing. +// The initial address for uncondensing, the start index for the first +// condensed slot in packed, and the count of pairs are provided. +void Uncondense(ELF::Addr addr, + const std::vector<ELF::Xword>& packed, + size_t start_index, + size_t end_index, + std::vector<ELF::Rel>* relocations) { + // The first relocation is just one created from the initial address. + ELF::Rel initial; + initial.r_offset = addr; + initial.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode); + relocations->push_back(initial); + + // Read each count and delta pair, beginning at the start index and + // finishing at the end index. + for (size_t i = start_index; i < end_index; i += 2) { + size_t count = packed[i]; + const ELF::Addr delta = packed[i + 1]; + CHECK(count > 0 && delta > 0); + + // Generate relocations for this count and delta pair. + while (count) { + addr += delta; + ELF::Rel relocation; + relocation.r_offset = addr; + relocation.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode); + relocations->push_back(relocation); + count--; + } + } +} + +} // namespace + +// Encode relative relocations into a run-length encoded (packed) +// representation. +void RelocationRunLengthCodec::Encode(const std::vector<ELF::Rel>& relocations, + std::vector<ELF::Xword>* packed) { + // If we have zero or one relocation only then there is no packing + // possible; a run-length encoding needs a run. + if (relocations.size() < 2) + return; + + std::vector<ELF::Addr> deltas; + GetDeltas(relocations, &deltas); + + // Reserve space for the element count. + packed->push_back(0); + + // Initialize the packed data with the first offset, then follow up with + // the condensed deltas vector. + packed->push_back(relocations[0].r_offset); + Condense(deltas, packed); + + // Fill in the packed pair count. + packed->at(0) = (packed->size() - 2) >> 1; +} + +// Decode relative relocations from a run-length encoded (packed) +// representation. +void RelocationRunLengthCodec::Decode(const std::vector<ELF::Xword>& packed, + std::vector<ELF::Rel>* relocations) { + // We need at least one packed pair after the packed pair count and start + // address to be able to unpack. + if (packed.size() < 4) + return; + + // Ensure that the packed data offers enough pairs. There may be zero + // padding on it that we ignore. + CHECK(packed[0] <= (packed.size() - 2) >> 1); + + // The first packed vector element is the pairs count and the second the + // initial address. Start uncondensing pairs at the third, and finish + // at the end of the pairs data. + const size_t pairs_count = packed[0]; + const ELF::Addr addr = packed[1]; + Uncondense(addr, packed, 2, 2 + (pairs_count << 1), relocations); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/run_length_encoder.h b/tools/relocation_packer/src/run_length_encoder.h new file mode 100644 index 0000000..f3a80e6 --- /dev/null +++ b/tools/relocation_packer/src/run_length_encoder.h @@ -0,0 +1,81 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Run-length encode and decode relative relocations. +// +// Relative relocations are the bulk of dynamic relocations (the +// .rel.dyn or .rela.dyn sections) in libchrome.<version>.so, and the ELF +// standard representation of them is wasteful. .rel.dyn contains +// relocations without addends, .rela.dyn relocations with addends. +// +// A relocation with no addend is 8 bytes on 32 bit platforms and 16 bytes +// on 64 bit plaforms, split into offset and info fields. Offsets strictly +// increase, and each is commonly a few bytes different from its predecessor. +// There are long runs where the difference does not change. The info field +// is constant. Example, from 'readelf -x4 libchrome.<version>.so' 32 bit: +// +// offset info offset info +// 808fef01 17000000 848fef01 17000000 ................ +// 888fef01 17000000 8c8fef01 17000000 ................ +// 908fef01 17000000 948fef01 17000000 ................ +// +// Run length encoding packs this data more efficiently, by representing it +// as a delta and a count of entries each differing from its predecessor +// by this delta. The above can be represented as a start address followed +// by an encoded count of 6 and offset difference of 4: +// +// start count diff +// 01ef8f80 00000006 00000004 +// +// Because relative relocation offsets strictly increase, the complete +// set of relative relocations in libchrome.<version>.so can be +// represented by a single start address followed by one or more difference +// and count encoded word pairs: +// +// start run1 count run1 diff run2 count run2 diff +// 01ef8f80 00000006 00000004 00000010 00000008 ... +// +// Decoding regenerates relative relocations beginning at address +// 'start' and for each encoded run, incrementing the address by 'difference' +// for 'count' iterations and emitting a new relative relocation. +// +// Once encoded, data is prefixed by a single word count of packed delta and +// count pairs. A final run-length encoded relative relocations vector +// might therefore look something like: +// +// pairs start run 1 run 2 ... run 15 +// 0000000f 01ef8f80 00000006 00000004 00000010 00000008 ... +// Interpreted as: +// pairs=15 start=.. count=6,delta=4 count=16,delta=8 + +#ifndef TOOLS_RELOCATION_PACKER_SRC_RUN_LENGTH_ENCODER_H_ +#define TOOLS_RELOCATION_PACKER_SRC_RUN_LENGTH_ENCODER_H_ + +#include <vector> + +#include "elf.h" +#include "elf_traits.h" + +namespace relocation_packer { + +// A RelocationRunLengthCodec packs vectors of relative relocations +// into more compact forms, and unpacks them to reproduce the pre-packed data. +class RelocationRunLengthCodec { + public: + // Encode relative relocations into a more compact form. + // |relocations| is a vector of relative relocation structs. + // |packed| is the vector of packed words into which relocations are packed. + static void Encode(const std::vector<ELF::Rel>& relocations, + std::vector<ELF::Xword>* packed); + + // Decode relative relocations from their more compact form. + // |packed| is the vector of packed relocations. + // |relocations| is a vector of unpacked relative relocation structs. + static void Decode(const std::vector<ELF::Xword>& packed, + std::vector<ELF::Rel>* relocations); +}; + +} // namespace relocation_packer + +#endif // TOOLS_RELOCATION_PACKER_SRC_RUN_LENGTH_ENCODER_H_ diff --git a/tools/relocation_packer/src/run_length_encoder_unittest.cc b/tools/relocation_packer/src/run_length_encoder_unittest.cc new file mode 100644 index 0000000..83370f2 --- /dev/null +++ b/tools/relocation_packer/src/run_length_encoder_unittest.cc @@ -0,0 +1,124 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "run_length_encoder.h" + +#include <vector> +#include "elf.h" +#include "elf_traits.h" +#include "testing/gtest/include/gtest/gtest.h" + +namespace { + +void AddRelocation(ELF::Addr addr, std::vector<ELF::Rel>* relocations) { + ELF::Rel relocation; + relocation.r_offset = addr; + relocation.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode); + relocations->push_back(relocation); +} + +bool CheckRelocation(ELF::Addr addr, const ELF::Rel& relocation) { + return relocation.r_offset == addr && + ELF_R_SYM(relocation.r_info) == 0 && + ELF_R_TYPE(relocation.r_info) == ELF::kRelativeRelocationCode; +} + +} // namespace + +namespace relocation_packer { + +TEST(RunLength, Encode) { + std::vector<ELF::Rel> relocations; + std::vector<ELF::Xword> packed; + + RelocationRunLengthCodec codec; + + packed.clear(); + codec.Encode(relocations, &packed); + + EXPECT_EQ(0, packed.size()); + + // Add one relocation (insufficient data to encode). + AddRelocation(0xf00d0000, &relocations); + + packed.clear(); + codec.Encode(relocations, &packed); + + EXPECT_EQ(0, packed.size()); + + // Add a second relocation, 4 byte delta (minimum data to encode). + AddRelocation(0xf00d0004, &relocations); + + packed.clear(); + codec.Encode(relocations, &packed); + + EXPECT_EQ(4, packed.size()); + // One count-delta pair present. + EXPECT_EQ(1, packed[0]); + // Initial relocation. + EXPECT_EQ(0xf00d0000, packed[1]); + // Run of a single relocation, 4 byte delta. + EXPECT_EQ(1, packed[2]); + EXPECT_EQ(4, packed[3]); + + // Add a third relocation, 4 byte delta. + AddRelocation(0xf00d0008, &relocations); + + // Add three more relocations, 8 byte deltas. + AddRelocation(0xf00d0010, &relocations); + AddRelocation(0xf00d0018, &relocations); + AddRelocation(0xf00d0020, &relocations); + + packed.clear(); + codec.Encode(relocations, &packed); + + EXPECT_EQ(6, packed.size()); + // Two count-delta pairs present. + EXPECT_EQ(2, packed[0]); + // Initial relocation. + EXPECT_EQ(0xf00d0000, packed[1]); + // Run of two relocations, 4 byte deltas. + EXPECT_EQ(2, packed[2]); + EXPECT_EQ(4, packed[3]); + // Run of three relocations, 8 byte deltas. + EXPECT_EQ(3, packed[4]); + EXPECT_EQ(8, packed[5]); +} + +TEST(RunLength, Decode) { + std::vector<ELF::Xword> packed; + std::vector<ELF::Rel> relocations; + + RelocationRunLengthCodec codec; + codec.Decode(packed, &relocations); + + EXPECT_EQ(0, relocations.size()); + + // Two count-delta pairs. + packed.push_back(2); + // Initial relocation. + packed.push_back(0xc0de0000); + // Run of two relocations, 4 byte deltas. + packed.push_back(2); + packed.push_back(4); + // Run of three relocations, 8 byte deltas. + packed.push_back(3); + packed.push_back(8); + + relocations.clear(); + codec.Decode(packed, &relocations); + + EXPECT_EQ(6, relocations.size()); + // Initial relocation. + EXPECT_TRUE(CheckRelocation(0xc0de0000, relocations[0])); + // Two relocations, 4 byte deltas. + EXPECT_TRUE(CheckRelocation(0xc0de0004, relocations[1])); + EXPECT_TRUE(CheckRelocation(0xc0de0008, relocations[2])); + // Three relocations, 8 byte deltas. + EXPECT_TRUE(CheckRelocation(0xc0de0010, relocations[3])); + EXPECT_TRUE(CheckRelocation(0xc0de0018, relocations[4])); + EXPECT_TRUE(CheckRelocation(0xc0de0020, relocations[5])); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/sleb128.cc b/tools/relocation_packer/src/sleb128.cc new file mode 100644 index 0000000..a10bd79 --- /dev/null +++ b/tools/relocation_packer/src/sleb128.cc @@ -0,0 +1,95 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "sleb128.h" + +#include <limits.h> +#include <stdint.h> +#include <vector> + +#include "elf_traits.h" + +namespace relocation_packer { + +// Empty constructor and destructor to silence chromium-style. +Sleb128Encoder::Sleb128Encoder() { } +Sleb128Encoder::~Sleb128Encoder() { } + +// Add a single value to the encoding. Values are encoded with variable +// length. The least significant 7 bits of each byte hold 7 bits of data, +// and the most significant bit is set on each byte except the last. The +// value is sign extended up to a multiple of 7 bits (ensuring that the +// most significant bit is zero for a positive number and one for a +// negative number). +void Sleb128Encoder::Enqueue(ELF::Sxword value) { + static const size_t size = CHAR_BIT * sizeof(value); + + bool more = true; + const bool negative = value < 0; + + while (more) { + uint8_t byte = value & 127; + value >>= 7; + + // Sign extend if encoding a -ve value. + if (negative) + value |= -(static_cast<ELF::Sxword>(1) << (size - 7)); + + // The sign bit of byte is second high order bit. + const bool sign_bit = byte & 64; + if ((value == 0 && !sign_bit) || (value == -1 && sign_bit)) + more = false; + else + byte |= 128; + encoding_.push_back(byte); + } +} + +// Add a vector of values to the encoding. +void Sleb128Encoder::EnqueueAll(const std::vector<ELF::Sxword>& values) { + for (size_t i = 0; i < values.size(); ++i) + Enqueue(values[i]); +} + +// Create a new decoder for the given encoded stream. +Sleb128Decoder::Sleb128Decoder(const std::vector<uint8_t>& encoding) { + encoding_ = encoding; + cursor_ = 0; +} + +// Empty destructor to silence chromium-style. +Sleb128Decoder::~Sleb128Decoder() { } + +// Decode and retrieve a single value from the encoding. Consume bytes +// until one without its most significant bit is found, and re-form the +// value from the 7 bit fields of the bytes consumed. +ELF::Sxword Sleb128Decoder::Dequeue() { + ELF::Sxword value = 0; + static const size_t size = CHAR_BIT * sizeof(value); + + size_t shift = 0; + uint8_t byte; + + // Loop until we reach a byte with its high order bit clear. + do { + byte = encoding_[cursor_++]; + value |= (static_cast<ELF::Sxword>(byte & 127) << shift); + shift += 7; + } while (byte & 128); + + // The sign bit is second high order bit of the final byte decoded. + // Sign extend if value is -ve and we did not shift all of it. + if (shift < size && (byte & 64)) + value |= -(static_cast<ELF::Sxword>(1) << shift); + + return value; +} + +// Decode and retrieve all remaining values from the encoding. +void Sleb128Decoder::DequeueAll(std::vector<ELF::Sxword>* values) { + while (cursor_ < encoding_.size()) + values->push_back(Dequeue()); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/src/sleb128.h b/tools/relocation_packer/src/sleb128.h new file mode 100644 index 0000000..3544543 --- /dev/null +++ b/tools/relocation_packer/src/sleb128.h @@ -0,0 +1,75 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// SLEB128 encoder and decoder for packed relative relocations. +// +// Delta encoded relative relocations consist of a large number +// of pairs signed integer values, many with small values. Encoding these +// as signed LEB128 saves space. +// +// For more on LEB128 see http://en.wikipedia.org/wiki/LEB128. + +#ifndef TOOLS_RELOCATION_PACKER_SRC_SLEB128_H_ +#define TOOLS_RELOCATION_PACKER_SRC_SLEB128_H_ + +#include <stdint.h> +#include <unistd.h> +#include <vector> + +#include "elf_traits.h" + +namespace relocation_packer { + +// Encode packed words as a signed LEB128 byte stream. +class Sleb128Encoder { + public: + // Explicit (but empty) constructor and destructor, for chromium-style. + Sleb128Encoder(); + ~Sleb128Encoder(); + + // Add a value to the encoding stream. + // |value| is the signed int to add. + void Enqueue(ELF::Sxword value); + + // Add a vector of values to the encoding stream. + // |values| is the vector of signed ints to add. + void EnqueueAll(const std::vector<ELF::Sxword>& values); + + // Retrieve the encoded representation of the values. + // |encoding| is the returned vector of encoded data. + void GetEncoding(std::vector<uint8_t>* encoding) { *encoding = encoding_; } + + private: + // Growable vector holding the encoded LEB128 stream. + std::vector<uint8_t> encoding_; +}; + +// Decode a LEB128 byte stream to produce packed words. +class Sleb128Decoder { + public: + // Create a new decoder for the given encoded stream. + // |encoding| is the vector of encoded data. + explicit Sleb128Decoder(const std::vector<uint8_t>& encoding); + + // Explicit (but empty) destructor, for chromium-style. + ~Sleb128Decoder(); + + // Retrieve the next value from the encoded stream. + ELF::Sxword Dequeue(); + + // Retrieve all remaining values from the encoded stream. + // |values| is the vector of decoded data. + void DequeueAll(std::vector<ELF::Sxword>* values); + + private: + // Encoded LEB128 stream. + std::vector<uint8_t> encoding_; + + // Cursor indicating the current stream retrieval point. + size_t cursor_; +}; + +} // namespace relocation_packer + +#endif // TOOLS_RELOCATION_PACKER_SRC_SLEB128_H_ diff --git a/tools/relocation_packer/src/sleb128_unittest.cc b/tools/relocation_packer/src/sleb128_unittest.cc new file mode 100644 index 0000000..60a5d0d --- /dev/null +++ b/tools/relocation_packer/src/sleb128_unittest.cc @@ -0,0 +1,166 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#include "sleb128.h" + +#include <vector> +#include "elf_traits.h" +#include "testing/gtest/include/gtest/gtest.h" + +namespace relocation_packer { + +TEST(Sleb128, Encoder) { + std::vector<ELF::Sxword> values; + values.push_back(624485); + values.push_back(0); + values.push_back(1); + values.push_back(63); + values.push_back(64); + values.push_back(-1); + values.push_back(-624485); + + Sleb128Encoder encoder; + encoder.EnqueueAll(values); + + encoder.Enqueue(2147483647); + encoder.Enqueue(-2147483648); + encoder.Enqueue(9223372036854775807ll); + encoder.Enqueue(-9223372036854775807ll - 1); + + std::vector<uint8_t> encoding; + encoder.GetEncoding(&encoding); + + EXPECT_EQ(42u, encoding.size()); + // 624485 + EXPECT_EQ(0xe5, encoding[0]); + EXPECT_EQ(0x8e, encoding[1]); + EXPECT_EQ(0x26, encoding[2]); + // 0 + EXPECT_EQ(0x00, encoding[3]); + // 1 + EXPECT_EQ(0x01, encoding[4]); + // 63 + EXPECT_EQ(0x3f, encoding[5]); + // 64 + EXPECT_EQ(0xc0, encoding[6]); + EXPECT_EQ(0x00, encoding[7]); + // -1 + EXPECT_EQ(0x7f, encoding[8]); + // -624485 + EXPECT_EQ(0x9b, encoding[9]); + EXPECT_EQ(0xf1, encoding[10]); + EXPECT_EQ(0x59, encoding[11]); + // 2147483647 + EXPECT_EQ(0xff, encoding[12]); + EXPECT_EQ(0xff, encoding[13]); + EXPECT_EQ(0xff, encoding[14]); + EXPECT_EQ(0xff, encoding[15]); + EXPECT_EQ(0x07, encoding[16]); + // -2147483648 + EXPECT_EQ(0x80, encoding[17]); + EXPECT_EQ(0x80, encoding[18]); + EXPECT_EQ(0x80, encoding[19]); + EXPECT_EQ(0x80, encoding[20]); + EXPECT_EQ(0x78, encoding[21]); + // 9223372036854775807 + EXPECT_EQ(0xff, encoding[22]); + EXPECT_EQ(0xff, encoding[23]); + EXPECT_EQ(0xff, encoding[24]); + EXPECT_EQ(0xff, encoding[25]); + EXPECT_EQ(0xff, encoding[26]); + EXPECT_EQ(0xff, encoding[27]); + EXPECT_EQ(0xff, encoding[28]); + EXPECT_EQ(0xff, encoding[29]); + EXPECT_EQ(0xff, encoding[30]); + EXPECT_EQ(0x00, encoding[31]); + // -9223372036854775808 + EXPECT_EQ(0x80, encoding[32]); + EXPECT_EQ(0x80, encoding[33]); + EXPECT_EQ(0x80, encoding[34]); + EXPECT_EQ(0x80, encoding[35]); + EXPECT_EQ(0x80, encoding[36]); + EXPECT_EQ(0x80, encoding[37]); + EXPECT_EQ(0x80, encoding[38]); + EXPECT_EQ(0x80, encoding[39]); + EXPECT_EQ(0x80, encoding[40]); + EXPECT_EQ(0x7f, encoding[41]); +} + +TEST(Sleb128, Decoder) { + std::vector<uint8_t> encoding; + // 624485 + encoding.push_back(0xe5); + encoding.push_back(0x8e); + encoding.push_back(0x26); + // 0 + encoding.push_back(0x00); + // 1 + encoding.push_back(0x01); + // 63 + encoding.push_back(0x3f); + // 64 + encoding.push_back(0xc0); + encoding.push_back(0x00); + // -1 + encoding.push_back(0x7f); + // -624485 + encoding.push_back(0x9b); + encoding.push_back(0xf1); + encoding.push_back(0x59); + // 2147483647 + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0x07); + // -2147483648 + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x78); + // 9223372036854775807 + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0xff); + encoding.push_back(0x00); + // -9223372036854775808 + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x80); + encoding.push_back(0x7f); + + Sleb128Decoder decoder(encoding); + + EXPECT_EQ(624485, decoder.Dequeue()); + + std::vector<ELF::Sxword> dequeued; + decoder.DequeueAll(&dequeued); + + EXPECT_EQ(10u, dequeued.size()); + EXPECT_EQ(0, dequeued[0]); + EXPECT_EQ(1, dequeued[1]); + EXPECT_EQ(63, dequeued[2]); + EXPECT_EQ(64, dequeued[3]); + EXPECT_EQ(-1, dequeued[4]); + EXPECT_EQ(-624485, dequeued[5]); + EXPECT_EQ(2147483647, dequeued[6]); + EXPECT_EQ(-2147483648, dequeued[7]); + EXPECT_EQ(9223372036854775807ll, dequeued[8]); + EXPECT_EQ(-9223372036854775807ll - 1, dequeued[9]); +} + +} // namespace relocation_packer diff --git a/tools/relocation_packer/test_data/elf_file_unittest_relocs.cc b/tools/relocation_packer/test_data/elf_file_unittest_relocs.cc new file mode 100644 index 0000000..5e1fa74 --- /dev/null +++ b/tools/relocation_packer/test_data/elf_file_unittest_relocs.cc @@ -0,0 +1,1014 @@ +// Copyright 2014 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +// Test data for packing/unpacking. When compiled, creates a run of +// relative relocations. +// +// See generate_elf_file_unittest_relocs.sh for instructions on how to build +// unit test data from this source file. + +const int i = 0; + +// Generator: +// python -c 'for i in xrange(0,1000):print"const void* pointer_%d = &i;"%i' +const void* pointer_0 = &i; +const void* pointer_1 = &i; +const void* pointer_2 = &i; +const void* pointer_3 = &i; +const void* pointer_4 = &i; +const void* pointer_5 = &i; +const void* pointer_6 = &i; +const void* pointer_7 = &i; +const void* pointer_8 = &i; +const void* pointer_9 = &i; +const void* pointer_10 = &i; +const void* pointer_11 = &i; +const void* pointer_12 = &i; +const void* pointer_13 = &i; +const void* pointer_14 = &i; +const void* pointer_15 = &i; +const void* pointer_16 = &i; +const void* pointer_17 = &i; +const void* pointer_18 = &i; +const void* pointer_19 = &i; +const void* pointer_20 = &i; +const void* pointer_21 = &i; +const void* pointer_22 = &i; +const void* pointer_23 = &i; +const void* pointer_24 = &i; +const void* pointer_25 = &i; +const void* pointer_26 = &i; +const void* pointer_27 = &i; +const void* pointer_28 = &i; +const void* pointer_29 = &i; +const void* pointer_30 = &i; +const void* pointer_31 = &i; +const void* pointer_32 = &i; +const void* pointer_33 = &i; +const void* pointer_34 = &i; +const void* pointer_35 = &i; +const void* pointer_36 = &i; +const void* pointer_37 = &i; +const void* pointer_38 = &i; +const void* pointer_39 = &i; +const void* pointer_40 = &i; +const void* pointer_41 = &i; +const void* pointer_42 = &i; +const void* pointer_43 = &i; +const void* pointer_44 = &i; +const void* pointer_45 = &i; +const void* pointer_46 = &i; +const void* pointer_47 = &i; +const void* pointer_48 = &i; +const void* pointer_49 = &i; +const void* pointer_50 = &i; +const void* pointer_51 = &i; +const void* pointer_52 = &i; +const void* pointer_53 = &i; +const void* pointer_54 = &i; +const void* pointer_55 = &i; +const void* pointer_56 = &i; +const void* pointer_57 = &i; +const void* pointer_58 = &i; +const void* pointer_59 = &i; +const void* pointer_60 = &i; +const void* pointer_61 = &i; +const void* pointer_62 = &i; +const void* pointer_63 = &i; +const void* pointer_64 = &i; +const void* pointer_65 = &i; +const void* pointer_66 = &i; +const void* pointer_67 = &i; +const void* pointer_68 = &i; +const void* pointer_69 = &i; +const void* pointer_70 = &i; +const void* pointer_71 = &i; +const void* pointer_72 = &i; +const void* pointer_73 = &i; +const void* pointer_74 = &i; +const void* pointer_75 = &i; +const void* pointer_76 = &i; +const void* pointer_77 = &i; +const void* pointer_78 = &i; +const void* pointer_79 = &i; +const void* pointer_80 = &i; +const void* pointer_81 = &i; +const void* pointer_82 = &i; +const void* pointer_83 = &i; +const void* pointer_84 = &i; +const void* pointer_85 = &i; +const void* pointer_86 = &i; +const void* pointer_87 = &i; +const void* pointer_88 = &i; +const void* pointer_89 = &i; +const void* pointer_90 = &i; +const void* pointer_91 = &i; +const void* pointer_92 = &i; +const void* pointer_93 = &i; +const void* pointer_94 = &i; +const void* pointer_95 = &i; +const void* pointer_96 = &i; +const void* pointer_97 = &i; +const void* pointer_98 = &i; +const void* pointer_99 = &i; +const void* pointer_100 = &i; +const void* pointer_101 = &i; +const void* pointer_102 = &i; +const void* pointer_103 = &i; +const void* pointer_104 = &i; +const void* pointer_105 = &i; +const void* pointer_106 = &i; +const void* pointer_107 = &i; +const void* pointer_108 = &i; +const void* pointer_109 = &i; +const void* pointer_110 = &i; +const void* pointer_111 = &i; +const void* pointer_112 = &i; +const void* pointer_113 = &i; +const void* pointer_114 = &i; +const void* pointer_115 = &i; +const void* pointer_116 = &i; +const void* pointer_117 = &i; +const void* pointer_118 = &i; +const void* pointer_119 = &i; +const void* pointer_120 = &i; +const void* pointer_121 = &i; +const void* pointer_122 = &i; +const void* pointer_123 = &i; +const void* pointer_124 = &i; +const void* pointer_125 = &i; +const void* pointer_126 = &i; +const void* pointer_127 = &i; +const void* pointer_128 = &i; +const void* pointer_129 = &i; +const void* pointer_130 = &i; +const void* pointer_131 = &i; +const void* pointer_132 = &i; +const void* pointer_133 = &i; +const void* pointer_134 = &i; +const void* pointer_135 = &i; +const void* pointer_136 = &i; +const void* pointer_137 = &i; +const void* pointer_138 = &i; +const void* pointer_139 = &i; +const void* pointer_140 = &i; +const void* pointer_141 = &i; +const void* pointer_142 = &i; +const void* pointer_143 = &i; +const void* pointer_144 = &i; +const void* pointer_145 = &i; +const void* pointer_146 = &i; +const void* pointer_147 = &i; +const void* pointer_148 = &i; +const void* pointer_149 = &i; +const void* pointer_150 = &i; +const void* pointer_151 = &i; +const void* pointer_152 = &i; +const void* pointer_153 = &i; +const void* pointer_154 = &i; +const void* pointer_155 = &i; +const void* pointer_156 = &i; +const void* pointer_157 = &i; +const void* pointer_158 = &i; +const void* pointer_159 = &i; +const void* pointer_160 = &i; +const void* pointer_161 = &i; +const void* pointer_162 = &i; +const void* pointer_163 = &i; +const void* pointer_164 = &i; +const void* pointer_165 = &i; +const void* pointer_166 = &i; +const void* pointer_167 = &i; +const void* pointer_168 = &i; +const void* pointer_169 = &i; +const void* pointer_170 = &i; +const void* pointer_171 = &i; +const void* pointer_172 = &i; +const void* pointer_173 = &i; +const void* pointer_174 = &i; +const void* pointer_175 = &i; +const void* pointer_176 = &i; +const void* pointer_177 = &i; +const void* pointer_178 = &i; +const void* pointer_179 = &i; +const void* pointer_180 = &i; +const void* pointer_181 = &i; +const void* pointer_182 = &i; +const void* pointer_183 = &i; +const void* pointer_184 = &i; +const void* pointer_185 = &i; +const void* pointer_186 = &i; +const void* pointer_187 = &i; +const void* pointer_188 = &i; +const void* pointer_189 = &i; +const void* pointer_190 = &i; +const void* pointer_191 = &i; +const void* pointer_192 = &i; +const void* pointer_193 = &i; +const void* pointer_194 = &i; +const void* pointer_195 = &i; +const void* pointer_196 = &i; +const void* pointer_197 = &i; +const void* pointer_198 = &i; +const void* pointer_199 = &i; +const void* pointer_200 = &i; +const void* pointer_201 = &i; +const void* pointer_202 = &i; +const void* pointer_203 = &i; +const void* pointer_204 = &i; +const void* pointer_205 = &i; +const void* pointer_206 = &i; +const void* pointer_207 = &i; +const void* pointer_208 = &i; +const void* pointer_209 = &i; +const void* pointer_210 = &i; +const void* pointer_211 = &i; +const void* pointer_212 = &i; +const void* pointer_213 = &i; +const void* pointer_214 = &i; +const void* pointer_215 = &i; +const void* pointer_216 = &i; +const void* pointer_217 = &i; +const void* pointer_218 = &i; +const void* pointer_219 = &i; +const void* pointer_220 = &i; +const void* pointer_221 = &i; +const void* pointer_222 = &i; +const void* pointer_223 = &i; +const void* pointer_224 = &i; +const void* pointer_225 = &i; +const void* pointer_226 = &i; +const void* pointer_227 = &i; +const void* pointer_228 = &i; +const void* pointer_229 = &i; +const void* pointer_230 = &i; +const void* pointer_231 = &i; +const void* pointer_232 = &i; +const void* pointer_233 = &i; +const void* pointer_234 = &i; +const void* pointer_235 = &i; +const void* pointer_236 = &i; +const void* pointer_237 = &i; +const void* pointer_238 = &i; +const void* pointer_239 = &i; +const void* pointer_240 = &i; +const void* pointer_241 = &i; +const void* pointer_242 = &i; +const void* pointer_243 = &i; +const void* pointer_244 = &i; +const void* pointer_245 = &i; +const void* pointer_246 = &i; +const void* pointer_247 = &i; +const void* pointer_248 = &i; +const void* pointer_249 = &i; +const void* pointer_250 = &i; +const void* pointer_251 = &i; +const void* pointer_252 = &i; +const void* pointer_253 = &i; +const void* pointer_254 = &i; +const void* pointer_255 = &i; +const void* pointer_256 = &i; +const void* pointer_257 = &i; +const void* pointer_258 = &i; +const void* pointer_259 = &i; +const void* pointer_260 = &i; +const void* pointer_261 = &i; +const void* pointer_262 = &i; +const void* pointer_263 = &i; +const void* pointer_264 = &i; +const void* pointer_265 = &i; +const void* pointer_266 = &i; +const void* pointer_267 = &i; +const void* pointer_268 = &i; +const void* pointer_269 = &i; +const void* pointer_270 = &i; +const void* pointer_271 = &i; +const void* pointer_272 = &i; +const void* pointer_273 = &i; +const void* pointer_274 = &i; +const void* pointer_275 = &i; +const void* pointer_276 = &i; +const void* pointer_277 = &i; +const void* pointer_278 = &i; +const void* pointer_279 = &i; +const void* pointer_280 = &i; +const void* pointer_281 = &i; +const void* pointer_282 = &i; +const void* pointer_283 = &i; +const void* pointer_284 = &i; +const void* pointer_285 = &i; +const void* pointer_286 = &i; +const void* pointer_287 = &i; +const void* pointer_288 = &i; +const void* pointer_289 = &i; +const void* pointer_290 = &i; +const void* pointer_291 = &i; +const void* pointer_292 = &i; +const void* pointer_293 = &i; +const void* pointer_294 = &i; +const void* pointer_295 = &i; +const void* pointer_296 = &i; +const void* pointer_297 = &i; +const void* pointer_298 = &i; +const void* pointer_299 = &i; +const void* pointer_300 = &i; +const void* pointer_301 = &i; +const void* pointer_302 = &i; +const void* pointer_303 = &i; +const void* pointer_304 = &i; +const void* pointer_305 = &i; +const void* pointer_306 = &i; +const void* pointer_307 = &i; +const void* pointer_308 = &i; +const void* pointer_309 = &i; +const void* pointer_310 = &i; +const void* pointer_311 = &i; +const void* pointer_312 = &i; +const void* pointer_313 = &i; +const void* pointer_314 = &i; +const void* pointer_315 = &i; +const void* pointer_316 = &i; +const void* pointer_317 = &i; +const void* pointer_318 = &i; +const void* pointer_319 = &i; +const void* pointer_320 = &i; +const void* pointer_321 = &i; +const void* pointer_322 = &i; +const void* pointer_323 = &i; +const void* pointer_324 = &i; +const void* pointer_325 = &i; +const void* pointer_326 = &i; +const void* pointer_327 = &i; +const void* pointer_328 = &i; +const void* pointer_329 = &i; +const void* pointer_330 = &i; +const void* pointer_331 = &i; +const void* pointer_332 = &i; +const void* pointer_333 = &i; +const void* pointer_334 = &i; +const void* pointer_335 = &i; +const void* pointer_336 = &i; +const void* pointer_337 = &i; +const void* pointer_338 = &i; +const void* pointer_339 = &i; +const void* pointer_340 = &i; +const void* pointer_341 = &i; +const void* pointer_342 = &i; +const void* pointer_343 = &i; +const void* pointer_344 = &i; +const void* pointer_345 = &i; +const void* pointer_346 = &i; +const void* pointer_347 = &i; +const void* pointer_348 = &i; +const void* pointer_349 = &i; +const void* pointer_350 = &i; +const void* pointer_351 = &i; +const void* pointer_352 = &i; +const void* pointer_353 = &i; +const void* pointer_354 = &i; +const void* pointer_355 = &i; +const void* pointer_356 = &i; +const void* pointer_357 = &i; +const void* pointer_358 = &i; +const void* pointer_359 = &i; +const void* pointer_360 = &i; +const void* pointer_361 = &i; +const void* pointer_362 = &i; +const void* pointer_363 = &i; +const void* pointer_364 = &i; +const void* pointer_365 = &i; +const void* pointer_366 = &i; +const void* pointer_367 = &i; +const void* pointer_368 = &i; +const void* pointer_369 = &i; +const void* pointer_370 = &i; +const void* pointer_371 = &i; +const void* pointer_372 = &i; +const void* pointer_373 = &i; +const void* pointer_374 = &i; +const void* pointer_375 = &i; +const void* pointer_376 = &i; +const void* pointer_377 = &i; +const void* pointer_378 = &i; +const void* pointer_379 = &i; +const void* pointer_380 = &i; +const void* pointer_381 = &i; +const void* pointer_382 = &i; +const void* pointer_383 = &i; +const void* pointer_384 = &i; +const void* pointer_385 = &i; +const void* pointer_386 = &i; +const void* pointer_387 = &i; +const void* pointer_388 = &i; +const void* pointer_389 = &i; +const void* pointer_390 = &i; +const void* pointer_391 = &i; +const void* pointer_392 = &i; +const void* pointer_393 = &i; +const void* pointer_394 = &i; +const void* pointer_395 = &i; +const void* pointer_396 = &i; +const void* pointer_397 = &i; +const void* pointer_398 = &i; +const void* pointer_399 = &i; +const void* pointer_400 = &i; +const void* pointer_401 = &i; +const void* pointer_402 = &i; +const void* pointer_403 = &i; +const void* pointer_404 = &i; +const void* pointer_405 = &i; +const void* pointer_406 = &i; +const void* pointer_407 = &i; +const void* pointer_408 = &i; +const void* pointer_409 = &i; +const void* pointer_410 = &i; +const void* pointer_411 = &i; +const void* pointer_412 = &i; +const void* pointer_413 = &i; +const void* pointer_414 = &i; +const void* pointer_415 = &i; +const void* pointer_416 = &i; +const void* pointer_417 = &i; +const void* pointer_418 = &i; +const void* pointer_419 = &i; +const void* pointer_420 = &i; +const void* pointer_421 = &i; +const void* pointer_422 = &i; +const void* pointer_423 = &i; +const void* pointer_424 = &i; +const void* pointer_425 = &i; +const void* pointer_426 = &i; +const void* pointer_427 = &i; +const void* pointer_428 = &i; +const void* pointer_429 = &i; +const void* pointer_430 = &i; +const void* pointer_431 = &i; +const void* pointer_432 = &i; +const void* pointer_433 = &i; +const void* pointer_434 = &i; +const void* pointer_435 = &i; +const void* pointer_436 = &i; +const void* pointer_437 = &i; +const void* pointer_438 = &i; +const void* pointer_439 = &i; +const void* pointer_440 = &i; +const void* pointer_441 = &i; +const void* pointer_442 = &i; +const void* pointer_443 = &i; +const void* pointer_444 = &i; +const void* pointer_445 = &i; +const void* pointer_446 = &i; +const void* pointer_447 = &i; +const void* pointer_448 = &i; +const void* pointer_449 = &i; +const void* pointer_450 = &i; +const void* pointer_451 = &i; +const void* pointer_452 = &i; +const void* pointer_453 = &i; +const void* pointer_454 = &i; +const void* pointer_455 = &i; +const void* pointer_456 = &i; +const void* pointer_457 = &i; +const void* pointer_458 = &i; +const void* pointer_459 = &i; +const void* pointer_460 = &i; +const void* pointer_461 = &i; +const void* pointer_462 = &i; +const void* pointer_463 = &i; +const void* pointer_464 = &i; +const void* pointer_465 = &i; +const void* pointer_466 = &i; +const void* pointer_467 = &i; +const void* pointer_468 = &i; +const void* pointer_469 = &i; +const void* pointer_470 = &i; +const void* pointer_471 = &i; +const void* pointer_472 = &i; +const void* pointer_473 = &i; +const void* pointer_474 = &i; +const void* pointer_475 = &i; +const void* pointer_476 = &i; +const void* pointer_477 = &i; +const void* pointer_478 = &i; +const void* pointer_479 = &i; +const void* pointer_480 = &i; +const void* pointer_481 = &i; +const void* pointer_482 = &i; +const void* pointer_483 = &i; +const void* pointer_484 = &i; +const void* pointer_485 = &i; +const void* pointer_486 = &i; +const void* pointer_487 = &i; +const void* pointer_488 = &i; +const void* pointer_489 = &i; +const void* pointer_490 = &i; +const void* pointer_491 = &i; +const void* pointer_492 = &i; +const void* pointer_493 = &i; +const void* pointer_494 = &i; +const void* pointer_495 = &i; +const void* pointer_496 = &i; +const void* pointer_497 = &i; +const void* pointer_498 = &i; +const void* pointer_499 = &i; +const void* pointer_500 = &i; +const void* pointer_501 = &i; +const void* pointer_502 = &i; +const void* pointer_503 = &i; +const void* pointer_504 = &i; +const void* pointer_505 = &i; +const void* pointer_506 = &i; +const void* pointer_507 = &i; +const void* pointer_508 = &i; +const void* pointer_509 = &i; +const void* pointer_510 = &i; +const void* pointer_511 = &i; +const void* pointer_512 = &i; +const void* pointer_513 = &i; +const void* pointer_514 = &i; +const void* pointer_515 = &i; +const void* pointer_516 = &i; +const void* pointer_517 = &i; +const void* pointer_518 = &i; +const void* pointer_519 = &i; +const void* pointer_520 = &i; +const void* pointer_521 = &i; +const void* pointer_522 = &i; +const void* pointer_523 = &i; +const void* pointer_524 = &i; +const void* pointer_525 = &i; +const void* pointer_526 = &i; +const void* pointer_527 = &i; +const void* pointer_528 = &i; +const void* pointer_529 = &i; +const void* pointer_530 = &i; +const void* pointer_531 = &i; +const void* pointer_532 = &i; +const void* pointer_533 = &i; +const void* pointer_534 = &i; +const void* pointer_535 = &i; +const void* pointer_536 = &i; +const void* pointer_537 = &i; +const void* pointer_538 = &i; +const void* pointer_539 = &i; +const void* pointer_540 = &i; +const void* pointer_541 = &i; +const void* pointer_542 = &i; +const void* pointer_543 = &i; +const void* pointer_544 = &i; +const void* pointer_545 = &i; +const void* pointer_546 = &i; +const void* pointer_547 = &i; +const void* pointer_548 = &i; +const void* pointer_549 = &i; +const void* pointer_550 = &i; +const void* pointer_551 = &i; +const void* pointer_552 = &i; +const void* pointer_553 = &i; +const void* pointer_554 = &i; +const void* pointer_555 = &i; +const void* pointer_556 = &i; +const void* pointer_557 = &i; +const void* pointer_558 = &i; +const void* pointer_559 = &i; +const void* pointer_560 = &i; +const void* pointer_561 = &i; +const void* pointer_562 = &i; +const void* pointer_563 = &i; +const void* pointer_564 = &i; +const void* pointer_565 = &i; +const void* pointer_566 = &i; +const void* pointer_567 = &i; +const void* pointer_568 = &i; +const void* pointer_569 = &i; +const void* pointer_570 = &i; +const void* pointer_571 = &i; +const void* pointer_572 = &i; +const void* pointer_573 = &i; +const void* pointer_574 = &i; +const void* pointer_575 = &i; +const void* pointer_576 = &i; +const void* pointer_577 = &i; +const void* pointer_578 = &i; +const void* pointer_579 = &i; +const void* pointer_580 = &i; +const void* pointer_581 = &i; +const void* pointer_582 = &i; +const void* pointer_583 = &i; +const void* pointer_584 = &i; +const void* pointer_585 = &i; +const void* pointer_586 = &i; +const void* pointer_587 = &i; +const void* pointer_588 = &i; +const void* pointer_589 = &i; +const void* pointer_590 = &i; +const void* pointer_591 = &i; +const void* pointer_592 = &i; +const void* pointer_593 = &i; +const void* pointer_594 = &i; +const void* pointer_595 = &i; +const void* pointer_596 = &i; +const void* pointer_597 = &i; +const void* pointer_598 = &i; +const void* pointer_599 = &i; +const void* pointer_600 = &i; +const void* pointer_601 = &i; +const void* pointer_602 = &i; +const void* pointer_603 = &i; +const void* pointer_604 = &i; +const void* pointer_605 = &i; +const void* pointer_606 = &i; +const void* pointer_607 = &i; +const void* pointer_608 = &i; +const void* pointer_609 = &i; +const void* pointer_610 = &i; +const void* pointer_611 = &i; +const void* pointer_612 = &i; +const void* pointer_613 = &i; +const void* pointer_614 = &i; +const void* pointer_615 = &i; +const void* pointer_616 = &i; +const void* pointer_617 = &i; +const void* pointer_618 = &i; +const void* pointer_619 = &i; +const void* pointer_620 = &i; +const void* pointer_621 = &i; +const void* pointer_622 = &i; +const void* pointer_623 = &i; +const void* pointer_624 = &i; +const void* pointer_625 = &i; +const void* pointer_626 = &i; +const void* pointer_627 = &i; +const void* pointer_628 = &i; +const void* pointer_629 = &i; +const void* pointer_630 = &i; +const void* pointer_631 = &i; +const void* pointer_632 = &i; +const void* pointer_633 = &i; +const void* pointer_634 = &i; +const void* pointer_635 = &i; +const void* pointer_636 = &i; +const void* pointer_637 = &i; +const void* pointer_638 = &i; +const void* pointer_639 = &i; +const void* pointer_640 = &i; +const void* pointer_641 = &i; +const void* pointer_642 = &i; +const void* pointer_643 = &i; +const void* pointer_644 = &i; +const void* pointer_645 = &i; +const void* pointer_646 = &i; +const void* pointer_647 = &i; +const void* pointer_648 = &i; +const void* pointer_649 = &i; +const void* pointer_650 = &i; +const void* pointer_651 = &i; +const void* pointer_652 = &i; +const void* pointer_653 = &i; +const void* pointer_654 = &i; +const void* pointer_655 = &i; +const void* pointer_656 = &i; +const void* pointer_657 = &i; +const void* pointer_658 = &i; +const void* pointer_659 = &i; +const void* pointer_660 = &i; +const void* pointer_661 = &i; +const void* pointer_662 = &i; +const void* pointer_663 = &i; +const void* pointer_664 = &i; +const void* pointer_665 = &i; +const void* pointer_666 = &i; +const void* pointer_667 = &i; +const void* pointer_668 = &i; +const void* pointer_669 = &i; +const void* pointer_670 = &i; +const void* pointer_671 = &i; +const void* pointer_672 = &i; +const void* pointer_673 = &i; +const void* pointer_674 = &i; +const void* pointer_675 = &i; +const void* pointer_676 = &i; +const void* pointer_677 = &i; +const void* pointer_678 = &i; +const void* pointer_679 = &i; +const void* pointer_680 = &i; +const void* pointer_681 = &i; +const void* pointer_682 = &i; +const void* pointer_683 = &i; +const void* pointer_684 = &i; +const void* pointer_685 = &i; +const void* pointer_686 = &i; +const void* pointer_687 = &i; +const void* pointer_688 = &i; +const void* pointer_689 = &i; +const void* pointer_690 = &i; +const void* pointer_691 = &i; +const void* pointer_692 = &i; +const void* pointer_693 = &i; +const void* pointer_694 = &i; +const void* pointer_695 = &i; +const void* pointer_696 = &i; +const void* pointer_697 = &i; +const void* pointer_698 = &i; +const void* pointer_699 = &i; +const void* pointer_700 = &i; +const void* pointer_701 = &i; +const void* pointer_702 = &i; +const void* pointer_703 = &i; +const void* pointer_704 = &i; +const void* pointer_705 = &i; +const void* pointer_706 = &i; +const void* pointer_707 = &i; +const void* pointer_708 = &i; +const void* pointer_709 = &i; +const void* pointer_710 = &i; +const void* pointer_711 = &i; +const void* pointer_712 = &i; +const void* pointer_713 = &i; +const void* pointer_714 = &i; +const void* pointer_715 = &i; +const void* pointer_716 = &i; +const void* pointer_717 = &i; +const void* pointer_718 = &i; +const void* pointer_719 = &i; +const void* pointer_720 = &i; +const void* pointer_721 = &i; +const void* pointer_722 = &i; +const void* pointer_723 = &i; +const void* pointer_724 = &i; +const void* pointer_725 = &i; +const void* pointer_726 = &i; +const void* pointer_727 = &i; +const void* pointer_728 = &i; +const void* pointer_729 = &i; +const void* pointer_730 = &i; +const void* pointer_731 = &i; +const void* pointer_732 = &i; +const void* pointer_733 = &i; +const void* pointer_734 = &i; +const void* pointer_735 = &i; +const void* pointer_736 = &i; +const void* pointer_737 = &i; +const void* pointer_738 = &i; +const void* pointer_739 = &i; +const void* pointer_740 = &i; +const void* pointer_741 = &i; +const void* pointer_742 = &i; +const void* pointer_743 = &i; +const void* pointer_744 = &i; +const void* pointer_745 = &i; +const void* pointer_746 = &i; +const void* pointer_747 = &i; +const void* pointer_748 = &i; +const void* pointer_749 = &i; +const void* pointer_750 = &i; +const void* pointer_751 = &i; +const void* pointer_752 = &i; +const void* pointer_753 = &i; +const void* pointer_754 = &i; +const void* pointer_755 = &i; +const void* pointer_756 = &i; +const void* pointer_757 = &i; +const void* pointer_758 = &i; +const void* pointer_759 = &i; +const void* pointer_760 = &i; +const void* pointer_761 = &i; +const void* pointer_762 = &i; +const void* pointer_763 = &i; +const void* pointer_764 = &i; +const void* pointer_765 = &i; +const void* pointer_766 = &i; +const void* pointer_767 = &i; +const void* pointer_768 = &i; +const void* pointer_769 = &i; +const void* pointer_770 = &i; +const void* pointer_771 = &i; +const void* pointer_772 = &i; +const void* pointer_773 = &i; +const void* pointer_774 = &i; +const void* pointer_775 = &i; +const void* pointer_776 = &i; +const void* pointer_777 = &i; +const void* pointer_778 = &i; +const void* pointer_779 = &i; +const void* pointer_780 = &i; +const void* pointer_781 = &i; +const void* pointer_782 = &i; +const void* pointer_783 = &i; +const void* pointer_784 = &i; +const void* pointer_785 = &i; +const void* pointer_786 = &i; +const void* pointer_787 = &i; +const void* pointer_788 = &i; +const void* pointer_789 = &i; +const void* pointer_790 = &i; +const void* pointer_791 = &i; +const void* pointer_792 = &i; +const void* pointer_793 = &i; +const void* pointer_794 = &i; +const void* pointer_795 = &i; +const void* pointer_796 = &i; +const void* pointer_797 = &i; +const void* pointer_798 = &i; +const void* pointer_799 = &i; +const void* pointer_800 = &i; +const void* pointer_801 = &i; +const void* pointer_802 = &i; +const void* pointer_803 = &i; +const void* pointer_804 = &i; +const void* pointer_805 = &i; +const void* pointer_806 = &i; +const void* pointer_807 = &i; +const void* pointer_808 = &i; +const void* pointer_809 = &i; +const void* pointer_810 = &i; +const void* pointer_811 = &i; +const void* pointer_812 = &i; +const void* pointer_813 = &i; +const void* pointer_814 = &i; +const void* pointer_815 = &i; +const void* pointer_816 = &i; +const void* pointer_817 = &i; +const void* pointer_818 = &i; +const void* pointer_819 = &i; +const void* pointer_820 = &i; +const void* pointer_821 = &i; +const void* pointer_822 = &i; +const void* pointer_823 = &i; +const void* pointer_824 = &i; +const void* pointer_825 = &i; +const void* pointer_826 = &i; +const void* pointer_827 = &i; +const void* pointer_828 = &i; +const void* pointer_829 = &i; +const void* pointer_830 = &i; +const void* pointer_831 = &i; +const void* pointer_832 = &i; +const void* pointer_833 = &i; +const void* pointer_834 = &i; +const void* pointer_835 = &i; +const void* pointer_836 = &i; +const void* pointer_837 = &i; +const void* pointer_838 = &i; +const void* pointer_839 = &i; +const void* pointer_840 = &i; +const void* pointer_841 = &i; +const void* pointer_842 = &i; +const void* pointer_843 = &i; +const void* pointer_844 = &i; +const void* pointer_845 = &i; +const void* pointer_846 = &i; +const void* pointer_847 = &i; +const void* pointer_848 = &i; +const void* pointer_849 = &i; +const void* pointer_850 = &i; +const void* pointer_851 = &i; +const void* pointer_852 = &i; +const void* pointer_853 = &i; +const void* pointer_854 = &i; +const void* pointer_855 = &i; +const void* pointer_856 = &i; +const void* pointer_857 = &i; +const void* pointer_858 = &i; +const void* pointer_859 = &i; +const void* pointer_860 = &i; +const void* pointer_861 = &i; +const void* pointer_862 = &i; +const void* pointer_863 = &i; +const void* pointer_864 = &i; +const void* pointer_865 = &i; +const void* pointer_866 = &i; +const void* pointer_867 = &i; +const void* pointer_868 = &i; +const void* pointer_869 = &i; +const void* pointer_870 = &i; +const void* pointer_871 = &i; +const void* pointer_872 = &i; +const void* pointer_873 = &i; +const void* pointer_874 = &i; +const void* pointer_875 = &i; +const void* pointer_876 = &i; +const void* pointer_877 = &i; +const void* pointer_878 = &i; +const void* pointer_879 = &i; +const void* pointer_880 = &i; +const void* pointer_881 = &i; +const void* pointer_882 = &i; +const void* pointer_883 = &i; +const void* pointer_884 = &i; +const void* pointer_885 = &i; +const void* pointer_886 = &i; +const void* pointer_887 = &i; +const void* pointer_888 = &i; +const void* pointer_889 = &i; +const void* pointer_890 = &i; +const void* pointer_891 = &i; +const void* pointer_892 = &i; +const void* pointer_893 = &i; +const void* pointer_894 = &i; +const void* pointer_895 = &i; +const void* pointer_896 = &i; +const void* pointer_897 = &i; +const void* pointer_898 = &i; +const void* pointer_899 = &i; +const void* pointer_900 = &i; +const void* pointer_901 = &i; +const void* pointer_902 = &i; +const void* pointer_903 = &i; +const void* pointer_904 = &i; +const void* pointer_905 = &i; +const void* pointer_906 = &i; +const void* pointer_907 = &i; +const void* pointer_908 = &i; +const void* pointer_909 = &i; +const void* pointer_910 = &i; +const void* pointer_911 = &i; +const void* pointer_912 = &i; +const void* pointer_913 = &i; +const void* pointer_914 = &i; +const void* pointer_915 = &i; +const void* pointer_916 = &i; +const void* pointer_917 = &i; +const void* pointer_918 = &i; +const void* pointer_919 = &i; +const void* pointer_920 = &i; +const void* pointer_921 = &i; +const void* pointer_922 = &i; +const void* pointer_923 = &i; +const void* pointer_924 = &i; +const void* pointer_925 = &i; +const void* pointer_926 = &i; +const void* pointer_927 = &i; +const void* pointer_928 = &i; +const void* pointer_929 = &i; +const void* pointer_930 = &i; +const void* pointer_931 = &i; +const void* pointer_932 = &i; +const void* pointer_933 = &i; +const void* pointer_934 = &i; +const void* pointer_935 = &i; +const void* pointer_936 = &i; +const void* pointer_937 = &i; +const void* pointer_938 = &i; +const void* pointer_939 = &i; +const void* pointer_940 = &i; +const void* pointer_941 = &i; +const void* pointer_942 = &i; +const void* pointer_943 = &i; +const void* pointer_944 = &i; +const void* pointer_945 = &i; +const void* pointer_946 = &i; +const void* pointer_947 = &i; +const void* pointer_948 = &i; +const void* pointer_949 = &i; +const void* pointer_950 = &i; +const void* pointer_951 = &i; +const void* pointer_952 = &i; +const void* pointer_953 = &i; +const void* pointer_954 = &i; +const void* pointer_955 = &i; +const void* pointer_956 = &i; +const void* pointer_957 = &i; +const void* pointer_958 = &i; +const void* pointer_959 = &i; +const void* pointer_960 = &i; +const void* pointer_961 = &i; +const void* pointer_962 = &i; +const void* pointer_963 = &i; +const void* pointer_964 = &i; +const void* pointer_965 = &i; +const void* pointer_966 = &i; +const void* pointer_967 = &i; +const void* pointer_968 = &i; +const void* pointer_969 = &i; +const void* pointer_970 = &i; +const void* pointer_971 = &i; +const void* pointer_972 = &i; +const void* pointer_973 = &i; +const void* pointer_974 = &i; +const void* pointer_975 = &i; +const void* pointer_976 = &i; +const void* pointer_977 = &i; +const void* pointer_978 = &i; +const void* pointer_979 = &i; +const void* pointer_980 = &i; +const void* pointer_981 = &i; +const void* pointer_982 = &i; +const void* pointer_983 = &i; +const void* pointer_984 = &i; +const void* pointer_985 = &i; +const void* pointer_986 = &i; +const void* pointer_987 = &i; +const void* pointer_988 = &i; +const void* pointer_989 = &i; +const void* pointer_990 = &i; +const void* pointer_991 = &i; +const void* pointer_992 = &i; +const void* pointer_993 = &i; +const void* pointer_994 = &i; +const void* pointer_995 = &i; +const void* pointer_996 = &i; +const void* pointer_997 = &i; +const void* pointer_998 = &i; +const void* pointer_999 = &i; diff --git a/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm32.so b/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm32.so Binary files differnew file mode 100755 index 0000000..6ce6d0c --- /dev/null +++ b/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm32.so diff --git a/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm32_packed.so b/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm32_packed.so Binary files differnew file mode 100755 index 0000000..7cfdd60 --- /dev/null +++ b/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm32_packed.so diff --git a/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm64.so b/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm64.so Binary files differnew file mode 100755 index 0000000..945b450 --- /dev/null +++ b/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm64.so diff --git a/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm64_packed.so b/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm64_packed.so Binary files differnew file mode 100755 index 0000000..532beac --- /dev/null +++ b/tools/relocation_packer/test_data/elf_file_unittest_relocs_arm64_packed.so diff --git a/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.py b/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.py new file mode 100755 index 0000000..e71b5cb --- /dev/null +++ b/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.py @@ -0,0 +1,88 @@ +#!/usr/bin/env python +# +# Copyright 2014 The Chromium Authors. All rights reserved. +# Use of this source code is governed by a BSD-style license that can be +# found in the LICENSE file. + +"""Build relocation packer unit test data. + +Uses a built relocation packer to generate 'golden' reference test data +files for elf_file_unittests.cc. +""" + +import optparse +import os +import shutil +import subprocess +import sys +import tempfile + +def PackArmLibraryRelocations(android_pack_relocations, + android_objcopy, + added_section, + input_path, + output_path): + # Copy and add a 'NULL' .android.rel.dyn section for the packing tool. + with tempfile.NamedTemporaryFile() as stream: + stream.write('NULL') + stream.flush() + objcopy_command = [android_objcopy, + '--add-section', '%s=%s' % (added_section, stream.name), + input_path, output_path] + subprocess.check_call(objcopy_command) + + # Pack relocations. + pack_command = [android_pack_relocations, output_path] + subprocess.check_call(pack_command) + + +def UnpackArmLibraryRelocations(android_pack_relocations, + input_path, + output_path): + shutil.copy(input_path, output_path) + + # Unpack relocations. We leave the .android.rel.dyn or .android.rela.dyn + # in place. + unpack_command = [android_pack_relocations, '-u', output_path] + subprocess.check_call(unpack_command) + + +def main(): + parser = optparse.OptionParser() + + parser.add_option('--android-pack-relocations', + help='Path to the ARM relocations packer binary') + parser.add_option('--android-objcopy', + help='Path to the toolchain\'s objcopy binary') + parser.add_option('--added-section', + choices=['.android.rel.dyn', '.android.rela.dyn'], + help='Section to add, one of ".android.rel.dyn" or ".android.rela.dyn"') + parser.add_option('--test-file', + help='Path to the input test file, an unpacked ARM .so') + parser.add_option('--unpacked-output', + help='Path to the output file for reference unpacked data') + parser.add_option('--packed-output', + help='Path to the output file for reference packed data') + + options, _ = parser.parse_args() + + for output in [options.unpacked_output, options.packed_output]: + directory = os.path.dirname(output) + if not os.path.exists(directory): + os.makedirs(directory) + + PackArmLibraryRelocations(options.android_pack_relocations, + options.android_objcopy, + options.added_section, + options.test_file, + options.packed_output) + + UnpackArmLibraryRelocations(options.android_pack_relocations, + options.packed_output, + options.unpacked_output) + + return 0 + + +if __name__ == '__main__': + sys.exit(main()) diff --git a/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.sh b/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.sh new file mode 100755 index 0000000..f90a2f6 --- /dev/null +++ b/tools/relocation_packer/test_data/generate_elf_file_unittest_relocs.sh @@ -0,0 +1,35 @@ +#!/bin/bash +# +# Copyright 2014 The Chromium Authors. All rights reserved. +# Use of this source code is governed by a BSD-style license that can be +# found in the LICENSE file. + +# Generates elf_file_unittest_relocs_arm{32,64}{,_packed}.so test data files +# from elf_file_unittest_relocs.cc. Run once to create these test data +# files; the files are checked into the source tree. +# +# To use: +# ./generate_elf_file_unittest_relocs.sh +# git add elf_file_unittest_relocs_arm{32,64}{,_packed}.so + +function main() { + local '-r' test_data_directory="$(pwd)" + cd '../../..' + + source tools/cr/cr-bash-helpers.sh + local arch + for arch in 'arm32' 'arm64'; do + cr 'init' '--platform=android' '--type=Debug' '--architecture='"${arch}" + cr 'build' 'relocation_packer_unittests_test_data' + done + + local '-r' packer='out_android/Debug/obj/tools/relocation_packer' + local '-r' gen="${packer}/relocation_packer_unittests_test_data.gen" + + cp "${gen}/elf_file_unittest_relocs_arm"{32,64}{,_packed}'.so' \ + "${test_data_directory}" + + return 0 +} + +main |