aosp12/art/libartbase/base/file_utils.cc

659 lines
25 KiB
C++

/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "file_utils.h"
#include <inttypes.h>
#include <sys/stat.h>
#include <sys/types.h>
#ifndef _WIN32
#include <sys/wait.h>
#endif
#include <unistd.h>
// We need dladdr.
#if !defined(__APPLE__) && !defined(_WIN32)
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#define DEFINED_GNU_SOURCE
#endif
#include <dlfcn.h>
#include <libgen.h>
#ifdef DEFINED_GNU_SOURCE
#undef _GNU_SOURCE
#undef DEFINED_GNU_SOURCE
#endif
#endif
#include <memory>
#include <sstream>
#include "android-base/file.h"
#include "android-base/stringprintf.h"
#include "android-base/strings.h"
#include "base/bit_utils.h"
#include "base/globals.h"
#include "base/os.h"
#include "base/stl_util.h"
#include "base/unix_file/fd_file.h"
#if defined(__APPLE__)
#include <crt_externs.h>
#include <sys/syscall.h>
#include "AvailabilityMacros.h" // For MAC_OS_X_VERSION_MAX_ALLOWED
#endif
#if defined(__linux__)
#include <linux/unistd.h>
#endif
namespace art {
using android::base::StringPrintf;
static constexpr const char* kClassesDex = "classes.dex";
static constexpr const char* kAndroidRootEnvVar = "ANDROID_ROOT";
static constexpr const char* kAndroidRootDefaultPath = "/system";
static constexpr const char* kAndroidSystemExtRootEnvVar = "ANDROID_SYSTEM_EXT";
static constexpr const char* kAndroidSystemExtRootDefaultPath = "/system_ext";
static constexpr const char* kAndroidDataEnvVar = "ANDROID_DATA";
static constexpr const char* kAndroidDataDefaultPath = "/data";
static constexpr const char* kAndroidArtRootEnvVar = "ANDROID_ART_ROOT";
static constexpr const char* kAndroidConscryptRootEnvVar = "ANDROID_CONSCRYPT_ROOT";
static constexpr const char* kAndroidI18nRootEnvVar = "ANDROID_I18N_ROOT";
static constexpr const char* kApexDefaultPath = "/apex/";
static constexpr const char* kArtApexDataEnvVar = "ART_APEX_DATA";
// Get the "root" directory containing the "lib" directory where this instance
// of the libartbase library (which contains `GetRootContainingLibartbase`) is
// located:
// - on host this "root" is normally the Android Root (e.g. something like
// "$ANDROID_BUILD_TOP/out/host/linux-x86/");
// - on target this "root" is normally the ART Root ("/apex/com.android.art").
// Return the empty string if that directory cannot be found or if this code is
// run on Windows or macOS.
static std::string GetRootContainingLibartbase() {
#if !defined( _WIN32) && !defined(__APPLE__)
// Check where libartbase is from, and derive from there.
Dl_info info;
if (dladdr(reinterpret_cast<const void*>(&GetRootContainingLibartbase), /* out */ &info) != 0) {
// Make a duplicate of the fname so dirname can modify it.
UniqueCPtr<char> fname(strdup(info.dli_fname));
char* dir1 = dirname(fname.get()); // This is the lib directory.
char* dir2 = dirname(dir1); // This is the "root" directory.
if (OS::DirectoryExists(dir2)) {
std::string tmp = dir2; // Make a copy here so that fname can be released.
return tmp;
}
}
#endif
return "";
}
std::string GetAndroidRootSafe(std::string* error_msg) {
#ifdef _WIN32
UNUSED(kAndroidRootEnvVar, kAndroidRootDefaultPath, GetRootContainingLibartbase);
*error_msg = "GetAndroidRootSafe unsupported for Windows.";
return "";
#else
// Prefer ANDROID_ROOT if it's set.
const char* android_root_from_env = getenv(kAndroidRootEnvVar);
if (android_root_from_env != nullptr) {
if (!OS::DirectoryExists(android_root_from_env)) {
*error_msg =
StringPrintf("Failed to find %s directory %s", kAndroidRootEnvVar, android_root_from_env);
return "";
}
return android_root_from_env;
}
// On host, libartbase is currently installed in "$ANDROID_ROOT/lib"
// (e.g. something like "$ANDROID_BUILD_TOP/out/host/linux-x86/lib". Use this
// information to infer the location of the Android Root (on host only).
//
// Note that this could change in the future, if we decided to install ART
// artifacts in a different location, e.g. within an "ART APEX" directory.
if (!kIsTargetBuild) {
std::string root_containing_libartbase = GetRootContainingLibartbase();
if (!root_containing_libartbase.empty()) {
return root_containing_libartbase;
}
}
// Try the default path.
if (!OS::DirectoryExists(kAndroidRootDefaultPath)) {
*error_msg =
StringPrintf("Failed to find default Android Root directory %s", kAndroidRootDefaultPath);
return "";
}
return kAndroidRootDefaultPath;
#endif
}
std::string GetAndroidRoot() {
std::string error_msg;
std::string ret = GetAndroidRootSafe(&error_msg);
if (ret.empty()) {
LOG(FATAL) << error_msg;
UNREACHABLE();
}
return ret;
}
static const char* GetAndroidDirSafe(const char* env_var,
const char* default_dir,
bool must_exist,
std::string* error_msg) {
const char* android_dir = getenv(env_var);
if (android_dir == nullptr) {
if (!must_exist || OS::DirectoryExists(default_dir)) {
android_dir = default_dir;
} else {
*error_msg = StringPrintf("%s not set and %s does not exist", env_var, default_dir);
return nullptr;
}
}
if (must_exist && !OS::DirectoryExists(android_dir)) {
*error_msg = StringPrintf("Failed to find directory %s", android_dir);
return nullptr;
}
return android_dir;
}
static const char* GetAndroidDir(const char* env_var,
const char* default_dir,
bool must_exist = true) {
std::string error_msg;
const char* dir = GetAndroidDirSafe(env_var, default_dir, must_exist, &error_msg);
if (dir != nullptr) {
return dir;
} else {
LOG(FATAL) << error_msg;
UNREACHABLE();
}
}
static std::string GetArtRootSafe(bool must_exist, /*out*/ std::string* error_msg) {
#ifdef _WIN32
UNUSED(kAndroidArtRootEnvVar, kAndroidArtApexDefaultPath, GetRootContainingLibartbase);
UNUSED(must_exist);
*error_msg = "GetArtRootSafe unsupported for Windows.";
return "";
#else
// Prefer ANDROID_ART_ROOT if it's set.
const char* android_art_root_from_env = getenv(kAndroidArtRootEnvVar);
if (android_art_root_from_env != nullptr) {
if (must_exist && !OS::DirectoryExists(android_art_root_from_env)) {
*error_msg = StringPrintf("Failed to find %s directory %s",
kAndroidArtRootEnvVar,
android_art_root_from_env);
return "";
}
return android_art_root_from_env;
}
// On target, libartbase is normally installed in
// "$ANDROID_ART_ROOT/lib(64)" (e.g. something like
// "/apex/com.android.art/lib(64)". Use this information to infer the
// location of the ART Root (on target only).
if (kIsTargetBuild) {
// *However*, a copy of libartbase may still be installed outside the
// ART Root on some occasions, as ART target gtests install their binaries
// and their dependencies under the Android Root, i.e. "/system" (see
// b/129534335). For that reason, we cannot reliably use
// `GetRootContainingLibartbase` to find the ART Root. (Note that this is
// not really a problem in practice, as Android Q devices define
// ANDROID_ART_ROOT in their default environment, and will instead use
// the logic above anyway.)
//
// TODO(b/129534335): Re-enable this logic when the only instance of
// libartbase on target is the one from the ART APEX.
if ((false)) {
std::string root_containing_libartbase = GetRootContainingLibartbase();
if (!root_containing_libartbase.empty()) {
return root_containing_libartbase;
}
}
}
// Try the default path.
if (must_exist && !OS::DirectoryExists(kAndroidArtApexDefaultPath)) {
*error_msg = StringPrintf("Failed to find default ART root directory %s",
kAndroidArtApexDefaultPath);
return "";
}
return kAndroidArtApexDefaultPath;
#endif
}
std::string GetArtRootSafe(std::string* error_msg) {
return GetArtRootSafe(/* must_exist= */ true, error_msg);
}
std::string GetArtRoot() {
std::string error_msg;
std::string ret = GetArtRootSafe(&error_msg);
if (ret.empty()) {
LOG(FATAL) << error_msg;
UNREACHABLE();
}
return ret;
}
std::string GetArtBinDir() {
// Environment variable `ANDROID_ART_ROOT` is defined as
// `$ANDROID_HOST_OUT/com.android.art` on host. However, host ART binaries are
// still installed in `$ANDROID_HOST_OUT/bin` (i.e. outside the ART Root). The
// situation is cleaner on target, where `ANDROID_ART_ROOT` is
// `$ANDROID_ROOT/apex/com.android.art` and ART binaries are installed in
// `$ANDROID_ROOT/apex/com.android.art/bin`.
std::string android_art_root = kIsTargetBuild ? GetArtRoot() : GetAndroidRoot();
return android_art_root + "/bin";
}
std::string GetAndroidDataSafe(std::string* error_msg) {
const char* android_dir = GetAndroidDirSafe(kAndroidDataEnvVar,
kAndroidDataDefaultPath,
/* must_exist= */ true,
error_msg);
return (android_dir != nullptr) ? android_dir : "";
}
std::string GetAndroidData() {
return GetAndroidDir(kAndroidDataEnvVar, kAndroidDataDefaultPath);
}
std::string GetArtApexData() {
return GetAndroidDir(kArtApexDataEnvVar, kArtApexDataDefaultPath, /*must_exist=*/false);
}
static std::string GetFirstBootClasspathExtensionJar(const std::string& android_root) {
DCHECK(kIsTargetBuild);
// This method finds the first non-APEX DEX file in the boot class path as defined by the
// DEX2OATBOOTCLASSPATH environment variable. This corresponds to the first boot classpath
// extension (see IMAGE SECTION documentation in image.h). When on-device signing is used the
// boot class extensions are compiled together as a single image with a name derived from the
// first extension. This first boot classpath extension is usually
// '/system/framework/framework.jar'.
//
// DEX2OATBOOTCLASSPATH is generated at build time by in the init.environ.rc.in:
// ${ANDROID_BUILD_TOP}/system/core/rootdir/Android.mk
// and initialized on Android by init in init.environ.rc:
// ${ANDROID_BUILD_TOP}/system/core/rootdir/init.environ.rc.in.
// It is used by installd too.
const char* bcp = getenv("DEX2OATBOOTCLASSPATH");
const std::string kDefaultBcpExtensionJar = android_root + "/framework/framework.jar";
if (bcp != nullptr) {
for (std::string_view component : SplitString(bcp, ':')) {
if (component.empty()) {
continue;
}
if (!LocationIsOnApex(component)) {
return std::string{component};
}
}
}
return kDefaultBcpExtensionJar;
}
std::string GetDefaultBootImageLocation(const std::string& android_root,
bool deny_art_apex_data_files) {
constexpr static const char* kJavalibBootArt = "javalib/boot.art";
constexpr static const char* kEtcBootImageProf = "etc/boot-image.prof";
// Boot image consists of two parts:
// - the primary boot image in the ART APEX (contains the Core Libraries)
// - the boot image extensions (contains framework libraries) on the system partition, or
// in the ART APEX data directory, if an update for the ART module has been been installed.
if (kIsTargetBuild && !deny_art_apex_data_files) {
// If the ART APEX has been updated, the compiled boot image extension will be in the ART APEX
// data directory (assuming there is space and we trust the artifacts there). Otherwise, for a factory installed ART APEX it is
// under $ANDROID_ROOT/framework/.
const std::string first_extension_jar{GetFirstBootClasspathExtensionJar(android_root)};
const std::string boot_extension_image = GetApexDataBootImage(first_extension_jar);
const std::string boot_extension_filename =
GetSystemImageFilename(boot_extension_image.c_str(), kRuntimeISA);
if (OS::FileExists(boot_extension_filename.c_str(), /*check_file_type=*/true)) {
return StringPrintf("%s/%s:%s!%s/%s",
kAndroidArtApexDefaultPath,
kJavalibBootArt,
boot_extension_image.c_str(),
android_root.c_str(),
kEtcBootImageProf);
} else if (errno == EACCES) {
// Additional warning for potential SELinux misconfiguration.
PLOG(ERROR) << "Default boot image check failed, could not stat: " << boot_extension_image;
}
}
return StringPrintf("%s/%s:%s/framework/boot-framework.art!%s/%s",
kAndroidArtApexDefaultPath,
kJavalibBootArt,
android_root.c_str(),
android_root.c_str(),
kEtcBootImageProf);
}
std::string GetDefaultBootImageLocation(std::string* error_msg) {
std::string android_root = GetAndroidRootSafe(error_msg);
if (android_root.empty()) {
return "";
}
return GetDefaultBootImageLocation(android_root, /*deny_art_apex_data_files=*/false);
}
static std::string GetDalvikCacheDirectory(std::string_view root_directory,
std::string_view sub_directory = {}) {
static constexpr std::string_view kDalvikCache = "dalvik-cache";
std::stringstream oss;
oss << root_directory << '/' << kDalvikCache;
if (!sub_directory.empty()) {
oss << '/' << sub_directory;
}
return oss.str();
}
void GetDalvikCache(const char* subdir, const bool create_if_absent, std::string* dalvik_cache,
bool* have_android_data, bool* dalvik_cache_exists, bool* is_global_cache) {
#ifdef _WIN32
UNUSED(subdir);
UNUSED(create_if_absent);
UNUSED(dalvik_cache);
UNUSED(have_android_data);
UNUSED(dalvik_cache_exists);
UNUSED(is_global_cache);
LOG(FATAL) << "GetDalvikCache unsupported on Windows.";
#else
CHECK(subdir != nullptr);
std::string unused_error_msg;
std::string android_data = GetAndroidDataSafe(&unused_error_msg);
if (android_data.empty()) {
*have_android_data = false;
*dalvik_cache_exists = false;
*is_global_cache = false;
return;
} else {
*have_android_data = true;
}
const std::string dalvik_cache_root = GetDalvikCacheDirectory(android_data);
*dalvik_cache = dalvik_cache_root + '/' + subdir;
*dalvik_cache_exists = OS::DirectoryExists(dalvik_cache->c_str());
*is_global_cache = (android_data == kAndroidDataDefaultPath);
if (create_if_absent && !*dalvik_cache_exists && !*is_global_cache) {
// Don't create the system's /data/dalvik-cache/... because it needs special permissions.
*dalvik_cache_exists = ((mkdir(dalvik_cache_root.c_str(), 0700) == 0 || errno == EEXIST) &&
(mkdir(dalvik_cache->c_str(), 0700) == 0 || errno == EEXIST));
}
#endif
}
bool GetDalvikCacheFilename(const char* location, const char* cache_location,
std::string* filename, std::string* error_msg) {
if (location[0] != '/') {
*error_msg = StringPrintf("Expected path in location to be absolute: %s", location);
return false;
}
std::string cache_file(&location[1]); // skip leading slash
if (!android::base::EndsWith(location, ".dex") &&
!android::base::EndsWith(location, ".art") &&
!android::base::EndsWith(location, ".oat")) {
cache_file += "/";
cache_file += kClassesDex;
}
std::replace(cache_file.begin(), cache_file.end(), '/', '@');
*filename = StringPrintf("%s/%s", cache_location, cache_file.c_str());
return true;
}
static std::string GetApexDataDalvikCacheDirectory(InstructionSet isa) {
if (isa != InstructionSet::kNone) {
return GetDalvikCacheDirectory(GetArtApexData(), GetInstructionSetString(isa));
}
return GetDalvikCacheDirectory(GetArtApexData());
}
static std::string GetApexDataDalvikCacheFilename(std::string_view dex_location,
InstructionSet isa,
bool encode_location,
std::string_view file_extension) {
if (LocationIsOnApex(dex_location)) {
return {};
}
std::string apex_data_dalvik_cache = GetApexDataDalvikCacheDirectory(isa);
if (encode_location) {
// Arguments: "/system/framework/xyz.jar", "arm", true, "odex"
// Result:
// "/data/misc/apexdata/com.android.art/dalvik-cache/arm/system@framework@xyz.jar@classes.odex"
std::string result, unused_error_msg;
GetDalvikCacheFilename(std::string{dex_location}.c_str(),
apex_data_dalvik_cache.c_str(),
&result,
&unused_error_msg);
return ReplaceFileExtension(result, file_extension);
} else {
// Arguments: "/system/framework/xyz.jar", "x86_64", false, "art"
// Results: "/data/misc/apexdata/com.android.art/dalvik-cache/x86_64/boot-xyz.jar@classes.art"
std::string basename = android::base::Basename(std::string{dex_location});
return apex_data_dalvik_cache + "/boot-" + ReplaceFileExtension(basename, file_extension);
}
}
std::string GetApexDataOatFilename(std::string_view location, InstructionSet isa) {
return GetApexDataDalvikCacheFilename(location, isa, /*encode_location=*/false, "oat");
}
std::string GetApexDataOdexFilename(std::string_view location, InstructionSet isa) {
return GetApexDataDalvikCacheFilename(location, isa, /*encode_location=*/true, "odex");
}
std::string GetApexDataBootImage(std::string_view dex_location) {
return GetApexDataDalvikCacheFilename(dex_location,
InstructionSet::kNone,
/*encode_location=*/false,
kArtImageExtension);
}
std::string GetApexDataImage(std::string_view dex_location) {
return GetApexDataDalvikCacheFilename(dex_location,
InstructionSet::kNone,
/*encode_location=*/true,
kArtImageExtension);
}
std::string GetApexDataDalvikCacheFilename(std::string_view dex_location,
InstructionSet isa,
std::string_view file_extension) {
return GetApexDataDalvikCacheFilename(
dex_location, isa, /*encode_location=*/true, file_extension);
}
std::string GetVdexFilename(const std::string& oat_location) {
return ReplaceFileExtension(oat_location, "vdex");
}
static void InsertIsaDirectory(const InstructionSet isa, std::string* filename) {
// in = /foo/bar/baz
// out = /foo/bar/<isa>/baz
size_t pos = filename->rfind('/');
CHECK_NE(pos, std::string::npos) << *filename << " " << isa;
filename->insert(pos, "/", 1);
filename->insert(pos + 1, GetInstructionSetString(isa));
}
std::string GetSystemImageFilename(const char* location, const InstructionSet isa) {
// location = /system/framework/boot.art
// filename = /system/framework/<isa>/boot.art
std::string filename(location);
InsertIsaDirectory(isa, &filename);
return filename;
}
std::string ReplaceFileExtension(std::string_view filename, std::string_view new_extension) {
const size_t last_ext = filename.find_last_of("./");
std::string result;
if (last_ext == std::string::npos || filename[last_ext] != '.') {
result.reserve(filename.size() + 1 + new_extension.size());
result.append(filename).append(".").append(new_extension);
} else {
result.reserve(last_ext + 1 + new_extension.size());
result.append(filename.substr(0, last_ext + 1)).append(new_extension);
}
return result;
}
bool LocationIsOnArtApexData(std::string_view location) {
const std::string art_apex_data = GetArtApexData();
return android::base::StartsWith(location, art_apex_data);
}
bool LocationIsOnArtModule(std::string_view full_path) {
std::string unused_error_msg;
std::string module_path = GetArtRootSafe(/* must_exist= */ kIsTargetBuild, &unused_error_msg);
if (module_path.empty()) {
return false;
}
return android::base::StartsWith(full_path, module_path);
}
static bool StartsWithSlash(const char* str) {
DCHECK(str != nullptr);
return str[0] == '/';
}
static bool EndsWithSlash(const char* str) {
DCHECK(str != nullptr);
size_t len = strlen(str);
return len > 0 && str[len - 1] == '/';
}
// Returns true if `full_path` is located in folder either provided with `env_var`
// or in `default_path` otherwise. The caller may optionally provide a `subdir`
// which will be appended to the tested prefix.
// `default_path` and the value of environment variable `env_var`
// are expected to begin with a slash and not end with one. If this ever changes,
// the path-building logic should be updated.
static bool IsLocationOn(std::string_view full_path,
const char* env_var,
const char* default_path,
const char* subdir = nullptr) {
std::string unused_error_msg;
const char* path = GetAndroidDirSafe(env_var,
default_path,
/* must_exist= */ kIsTargetBuild,
&unused_error_msg);
if (path == nullptr) {
return false;
}
// Build the path which we will check is a prefix of `full_path`. The prefix must
// end with a slash, so that "/foo/bar" does not match "/foo/barz".
DCHECK(StartsWithSlash(path)) << path;
std::string path_prefix(path);
if (!EndsWithSlash(path_prefix.c_str())) {
path_prefix.append("/");
}
if (subdir != nullptr) {
// If `subdir` is provided, we assume it is provided without a starting slash
// but ending with one, e.g. "sub/dir/". `path_prefix` ends with a slash at
// this point, so we simply append `subdir`.
DCHECK(!StartsWithSlash(subdir) && EndsWithSlash(subdir)) << subdir;
path_prefix.append(subdir);
}
return android::base::StartsWith(full_path, path_prefix);
}
bool LocationIsOnSystemFramework(std::string_view full_path) {
return IsLocationOn(full_path,
kAndroidRootEnvVar,
kAndroidRootDefaultPath,
/* subdir= */ "framework/");
}
bool LocationIsOnSystemExtFramework(std::string_view full_path) {
return IsLocationOn(full_path,
kAndroidSystemExtRootEnvVar,
kAndroidSystemExtRootDefaultPath,
/* subdir= */ "framework/") ||
// When the 'system_ext' partition is not present, builds will create
// '/system/system_ext' instead.
IsLocationOn(full_path,
kAndroidRootEnvVar,
kAndroidRootDefaultPath,
/* subdir= */ "system_ext/framework/");
}
bool LocationIsOnConscryptModule(std::string_view full_path) {
return IsLocationOn(
full_path, kAndroidConscryptRootEnvVar, kAndroidConscryptApexDefaultPath);
}
bool LocationIsOnI18nModule(std::string_view full_path) {
return IsLocationOn(
full_path, kAndroidI18nRootEnvVar, kAndroidI18nApexDefaultPath);
}
bool LocationIsOnApex(std::string_view full_path) {
return android::base::StartsWith(full_path, kApexDefaultPath);
}
bool LocationIsOnSystem(const std::string& location) {
#ifdef _WIN32
UNUSED(location);
LOG(FATAL) << "LocationIsOnSystem is unsupported on Windows.";
return false;
#else
UniqueCPtr<const char[]> full_path(realpath(location.c_str(), nullptr));
return full_path != nullptr &&
android::base::StartsWith(full_path.get(), GetAndroidRoot().c_str());
#endif
}
bool LocationIsTrusted(const std::string& location, bool trust_art_apex_data_files) {
if (LocationIsOnSystem(location)) {
return true;
}
return LocationIsOnArtApexData(location) & trust_art_apex_data_files;
}
bool ArtModuleRootDistinctFromAndroidRoot() {
std::string error_msg;
const char* android_root = GetAndroidDirSafe(kAndroidRootEnvVar,
kAndroidRootDefaultPath,
/* must_exist= */ kIsTargetBuild,
&error_msg);
const char* art_root = GetAndroidDirSafe(kAndroidArtRootEnvVar,
kAndroidArtApexDefaultPath,
/* must_exist= */ kIsTargetBuild,
&error_msg);
return (android_root != nullptr)
&& (art_root != nullptr)
&& (std::string_view(android_root) != std::string_view(art_root));
}
int DupCloexec(int fd) {
#if defined(__linux__)
return fcntl(fd, F_DUPFD_CLOEXEC, 0);
#else
return dup(fd);
#endif
}
} // namespace art