Load namespace configuration from ld.config.txt
This change allows customization of default namespace
configuration for different executables. It also enables
target_sdk_version setup for binaries (note that this
option should explicitly be enabled in ld.config.txt).
Bug: http://b/30706810
Bug: http://b/30435785
Test: run linker-unit-tests/bionic-unit-tests, boot angler
Change-Id: Ibbe87209acf1538fc9cec04944f3d22a190c38f1
diff --git a/linker/linker_config.cpp b/linker/linker_config.cpp
new file mode 100644
index 0000000..33616f7
--- /dev/null
+++ b/linker/linker_config.cpp
@@ -0,0 +1,487 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ * 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.
+ *
+ * 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.
+ */
+
+#include "linker_config.h"
+
+#include "linker_globals.h"
+#include "linker_debug.h"
+#include "linker_utils.h"
+
+#include <android-base/file.h>
+#include <android-base/strings.h>
+
+#include <private/ScopeGuard.h>
+
+#include <stdlib.h>
+
+#include <string>
+#include <unordered_map>
+
+class ConfigParser {
+ public:
+ enum {
+ kProperty,
+ kSection,
+ kEndOfFile,
+ kError,
+ };
+
+ explicit ConfigParser(std::string&& content)
+ : content_(content), p_(0), lineno_(0), was_end_of_file_(false) {}
+
+ /*
+ * Possible return values
+ * kProperty: name is set to property name and value is set to property value
+ * kSection: name is set to section name.
+ * kEndOfFile: reached end of file.
+ * kError: error_msg is set.
+ */
+ int next_token(std::string* name, std::string* value, std::string* error_msg) {
+ std::string line;
+ while(NextLine(&line)) {
+ size_t found = line.find('#');
+ line = android::base::Trim(line.substr(0, found));
+
+ if (line.empty()) {
+ continue;
+ }
+
+ if (line[0] == '[' && line[line.size() - 1] == ']') {
+ *name = line.substr(1, line.size() - 2);
+ return kSection;
+ }
+
+ found = line.find('=');
+ if (found == std::string::npos) {
+ *error_msg = std::string("invalid format: ") +
+ line +
+ ", expected \"name = property\" or \"[section]\"";
+ return kError;
+ }
+
+ *name = android::base::Trim(line.substr(0, found));
+ *value = android::base::Trim(line.substr(found + 1));
+ return kProperty;
+ }
+
+ // to avoid infinite cycles when programmer makes a mistake
+ CHECK(!was_end_of_file_);
+ was_end_of_file_ = true;
+ return kEndOfFile;
+ }
+
+ size_t lineno() const {
+ return lineno_;
+ }
+
+ private:
+ bool NextLine(std::string* line) {
+ if (p_ == std::string::npos) {
+ return false;
+ }
+
+ size_t found = content_.find('\n', p_);
+ if (found != std::string::npos) {
+ *line = content_.substr(p_, found - p_);
+ p_ = found + 1;
+ } else {
+ *line = content_.substr(p_);
+ p_ = std::string::npos;
+ }
+
+ lineno_++;
+ return true;
+ }
+
+ std::string content_;
+ size_t p_;
+ size_t lineno_;
+ bool was_end_of_file_;
+
+ DISALLOW_IMPLICIT_CONSTRUCTORS(ConfigParser);
+};
+
+class PropertyValue {
+ public:
+ PropertyValue() = default;
+
+ PropertyValue(std::string&& value, size_t lineno)
+ : value_(value), lineno_(lineno) {}
+
+ const std::string& value() const {
+ return value_;
+ }
+
+ size_t lineno() const {
+ return lineno_;
+ }
+
+ private:
+ std::string value_;
+ size_t lineno_;
+};
+
+static std::string create_error_msg(const char* file,
+ size_t lineno,
+ const std::string& msg) {
+ char buf[1024];
+ __libc_format_buffer(buf, sizeof(buf), "%s:%zu: error: %s", file, lineno, msg.c_str());
+
+ return std::string(buf);
+}
+
+static bool parse_config_file(const char* ld_config_file_path,
+ const char* binary_realpath,
+ std::unordered_map<std::string, PropertyValue>* properties,
+ std::string* error_msg) {
+ std::string content;
+ if (!android::base::ReadFileToString(ld_config_file_path, &content)) {
+ if (errno != ENOENT) {
+ *error_msg = std::string("error reading file \"") +
+ ld_config_file_path + "\": " + strerror(errno);
+ }
+ return false;
+ }
+
+ ConfigParser cp(std::move(content));
+
+ std::string section_name;
+
+ while(true) {
+ std::string name;
+ std::string value;
+ std::string error;
+
+ int result = cp.next_token(&name, &value, &error);
+ if (result == ConfigParser::kError) {
+ DL_WARN("error parsing %s:%zd: %s (ignoring this line)",
+ ld_config_file_path,
+ cp.lineno(),
+ error.c_str());
+ continue;
+ }
+
+ if (result == ConfigParser::kSection || result == ConfigParser::kEndOfFile) {
+ return false;
+ }
+
+ if (result == ConfigParser::kProperty) {
+ if (!android::base::StartsWith(name, "dir.")) {
+ DL_WARN("error parsing %s:%zd: unexpected property name \"%s\", "
+ "expected format dir.<section_name> (ignoring this line)",
+ ld_config_file_path,
+ cp.lineno(),
+ name.c_str());
+ continue;
+ }
+
+ // remove trailing '/'
+ while (value[value.size() - 1] == '/') {
+ value = value.substr(0, value.size() - 1);
+ }
+
+ if (value.empty()) {
+ DL_WARN("error parsing %s:%zd: property value is empty (ignoring this line)",
+ ld_config_file_path,
+ cp.lineno());
+ continue;
+ }
+
+ if (file_is_under_dir(binary_realpath, value)) {
+ section_name = name.substr(4);
+ break;
+ }
+ }
+ }
+
+ // skip everything until we meet a correct section
+ while (true) {
+ std::string name;
+ std::string value;
+ std::string error;
+
+ int result = cp.next_token(&name, &value, &error);
+
+ if (result == ConfigParser::kSection && name == section_name) {
+ break;
+ }
+
+ if (result == ConfigParser::kEndOfFile) {
+ *error_msg = create_error_msg(ld_config_file_path,
+ cp.lineno(),
+ std::string("section \"") + section_name + "\" not found");
+ return false;
+ }
+ }
+
+ // found the section - parse it
+ while (true) {
+ std::string name;
+ std::string value;
+ std::string error;
+
+ int result = cp.next_token(&name, &value, &error);
+
+ if (result == ConfigParser::kEndOfFile || result == ConfigParser::kSection) {
+ break;
+ }
+
+ if (result == ConfigParser::kProperty) {
+ if (properties->find(name) != properties->end()) {
+ DL_WARN("%s:%zd: warning: property \"%s\" redefinition",
+ ld_config_file_path,
+ cp.lineno(),
+ name.c_str());
+ }
+
+ (*properties)[name] = PropertyValue(std::move(value), cp.lineno());
+ }
+
+ if (result == ConfigParser::kError) {
+ DL_WARN("error parsing %s:%zd: %s (ignoring this line)",
+ ld_config_file_path,
+ cp.lineno(),
+ error.c_str());
+ continue;
+ }
+ }
+
+ return true;
+}
+
+static Config g_config;
+
+static constexpr const char* kDefaultConfigName = "default";
+static constexpr const char* kPropertyAdditionalNamespaces = "additional.namespaces";
+#if defined(__LP64__)
+static constexpr const char* kLibParamValue = "lib64";
+#else
+static constexpr const char* kLibParamValue = "lib";
+#endif
+
+class Properties {
+ public:
+ explicit Properties(std::unordered_map<std::string, PropertyValue>&& properties)
+ : properties_(properties), target_sdk_version_(__ANDROID_API__) {}
+
+ std::vector<std::string> get_strings(const std::string& name, size_t* lineno = nullptr) const {
+ auto it = find_property(name, lineno);
+ if (it == properties_.end()) {
+ // return empty vector
+ return std::vector<std::string>();
+ }
+
+ std::vector<std::string> strings = android::base::Split(it->second.value(), ",");
+
+ for (size_t i = 0; i < strings.size(); ++i) {
+ strings[i] = android::base::Trim(strings[i]);
+ }
+
+ return strings;
+ }
+
+ bool get_bool(const std::string& name, size_t* lineno = nullptr) const {
+ auto it = find_property(name, lineno);
+ if (it == properties_.end()) {
+ return false;
+ }
+
+ return it->second.value() == "true";
+ }
+
+ std::string get_string(const std::string& name, size_t* lineno = nullptr) const {
+ auto it = find_property(name, lineno);
+ return (it == properties_.end()) ? "" : it->second.value();
+ }
+
+ std::vector<std::string> get_paths(const std::string& name, size_t* lineno = nullptr) {
+ std::string paths_str = get_string(name, lineno);
+
+ std::vector<std::string> paths;
+ split_path(paths_str.c_str(), ":", &paths);
+
+ std::vector<std::pair<std::string, std::string>> params;
+ params.push_back({ "LIB", kLibParamValue });
+ if (target_sdk_version_ != 0) {
+ char buf[16];
+ __libc_format_buffer(buf, sizeof(buf), "%d", target_sdk_version_);
+ params.push_back({ "SDK_VER", buf });
+ }
+
+ for (auto&& path : paths) {
+ format_string(&path, params);
+ }
+
+ std::vector<std::string> resolved_paths;
+
+ // do not remove paths that do not exist
+ resolve_paths(paths, &resolved_paths);
+
+ return resolved_paths;
+ }
+
+ void set_target_sdk_version(int target_sdk_version) {
+ target_sdk_version_ = target_sdk_version;
+ }
+
+ private:
+ std::unordered_map<std::string, PropertyValue>::const_iterator
+ find_property(const std::string& name, size_t* lineno) const {
+ auto it = properties_.find(name);
+ if (it != properties_.end() && lineno != nullptr) {
+ *lineno = it->second.lineno();
+ }
+
+ return it;
+ }
+ std::unordered_map<std::string, PropertyValue> properties_;
+ int target_sdk_version_;
+
+ DISALLOW_IMPLICIT_CONSTRUCTORS(Properties);
+};
+
+bool Config::read_binary_config(const char* ld_config_file_path,
+ const char* binary_realpath,
+ bool is_asan,
+ const Config** config,
+ std::string* error_msg) {
+ g_config.clear();
+
+ std::unordered_map<std::string, PropertyValue> property_map;
+ if (!parse_config_file(ld_config_file_path, binary_realpath, &property_map, error_msg)) {
+ return false;
+ }
+
+ Properties properties(std::move(property_map));
+
+ auto failure_guard = make_scope_guard([] {
+ g_config.clear();
+ });
+
+ std::unordered_map<std::string, NamespaceConfig*> namespace_configs;
+
+ namespace_configs[kDefaultConfigName] = g_config.create_namespace_config(kDefaultConfigName);
+
+ std::vector<std::string> additional_namespaces = properties.get_strings(kPropertyAdditionalNamespaces);
+ for (const auto& name : additional_namespaces) {
+ namespace_configs[name] = g_config.create_namespace_config(name);
+ }
+
+ bool versioning_enabled = properties.get_bool("enable.target.sdk.version");
+ int target_sdk_version = __ANDROID_API__;
+ if (versioning_enabled) {
+ std::string version_file = dirname(binary_realpath) + "/.version";
+ std::string content;
+ if (!android::base::ReadFileToString(version_file, &content)) {
+ if (errno != ENOENT) {
+ *error_msg = std::string("error reading version file \"") +
+ version_file + "\": " + strerror(errno);
+ return false;
+ }
+ } else {
+ content = android::base::Trim(content);
+ errno = 0;
+ char* end = nullptr;
+ const char* content_str = content.c_str();
+ int result = strtol(content_str, &end, 10);
+ if (errno == 0 && *end == '\0' && result > 0) {
+ target_sdk_version = result;
+ properties.set_target_sdk_version(target_sdk_version);
+ } else {
+ *error_msg = std::string("invalid version \"") + version_file + "\": \"" + content +"\"";
+ return false;
+ }
+ }
+ }
+
+ g_config.set_target_sdk_version(target_sdk_version);
+
+ for (auto ns_config_it : namespace_configs) {
+ auto& name = ns_config_it.first;
+ NamespaceConfig* ns_config = ns_config_it.second;
+
+ std::string property_name_prefix = std::string("namespace.") + name;
+
+ size_t lineno = 0;
+ std::vector<std::string> linked_namespaces =
+ properties.get_strings(property_name_prefix + ".links", &lineno);
+
+ for (const auto& linked_ns_name : linked_namespaces) {
+ if (namespace_configs.find(linked_ns_name) == namespace_configs.end()) {
+ *error_msg = create_error_msg(ld_config_file_path,
+ lineno,
+ std::string("undefined namespace: ") + linked_ns_name);
+ return false;
+ }
+
+ std::string shared_libs = properties.get_string(property_name_prefix +
+ ".link." +
+ linked_ns_name +
+ ".shared_libs", &lineno);
+
+ if (shared_libs.empty()) {
+ *error_msg = create_error_msg(ld_config_file_path,
+ lineno,
+ std::string("list of shared_libs for ") +
+ name +
+ "->" +
+ linked_ns_name +
+ " link is not specified or is empty.");
+ return false;
+ }
+
+ ns_config->add_namespace_link(linked_ns_name, shared_libs);
+ }
+
+ ns_config->set_isolated(properties.get_bool(property_name_prefix + ".isolated"));
+
+ // these are affected by is_asan flag
+ if (is_asan) {
+ property_name_prefix += ".asan";
+ }
+
+ ns_config->set_search_paths(properties.get_paths(property_name_prefix + ".search.paths"));
+ ns_config->set_permitted_paths(properties.get_paths(property_name_prefix + ".permitted.paths"));
+ }
+
+ failure_guard.disable();
+ *config = &g_config;
+ return true;
+}
+
+NamespaceConfig* Config::create_namespace_config(const std::string& name) {
+ namespace_configs_.push_back(std::unique_ptr<NamespaceConfig>(new NamespaceConfig(name)));
+ NamespaceConfig* ns_config_ptr = namespace_configs_.back().get();
+ namespace_configs_map_[name] = ns_config_ptr;
+ return ns_config_ptr;
+}
+
+void Config::clear() {
+ namespace_configs_.clear();
+ namespace_configs_map_.clear();
+}