4374 lines
134 KiB
C++
4374 lines
134 KiB
C++
/*
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* Copyright (C) 2008 The Android Open Source Project
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
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* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include <android/api-level.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <inttypes.h>
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#include <pthread.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/mman.h>
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#include <sys/param.h>
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#include <unistd.h>
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#include <new>
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#include <string>
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#include <unordered_map>
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#include <vector>
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// Private C library headers.
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#include "private/bionic_tls.h"
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#include "private/KernelArgumentBlock.h"
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#include "private/ScopedPthreadMutexLocker.h"
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#include "private/ScopeGuard.h"
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#include "linker.h"
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#include "linker_block_allocator.h"
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#include "linker_debug.h"
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#include "linker_dlwarning.h"
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#include "linker_sleb128.h"
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#include "linker_phdr.h"
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#include "linker_relocs.h"
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#include "linker_reloc_iterators.h"
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#include "linker_utils.h"
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#include "android-base/strings.h"
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#include "ziparchive/zip_archive.h"
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extern void __libc_init_globals(KernelArgumentBlock&);
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extern void __libc_init_AT_SECURE(KernelArgumentBlock&);
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// Override macros to use C++ style casts.
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#undef ELF_ST_TYPE
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#define ELF_ST_TYPE(x) (static_cast<uint32_t>(x) & 0xf)
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struct android_namespace_t {
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public:
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android_namespace_t() : name_(nullptr), is_isolated_(false) {}
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const char* get_name() const { return name_; }
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void set_name(const char* name) { name_ = name; }
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bool is_isolated() const { return is_isolated_; }
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void set_isolated(bool isolated) { is_isolated_ = isolated; }
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const std::vector<std::string>& get_ld_library_paths() const {
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return ld_library_paths_;
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}
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void set_ld_library_paths(std::vector<std::string>&& library_paths) {
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ld_library_paths_ = library_paths;
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}
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const std::vector<std::string>& get_default_library_paths() const {
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return default_library_paths_;
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}
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void set_default_library_paths(std::vector<std::string>&& library_paths) {
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default_library_paths_ = library_paths;
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}
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const std::vector<std::string>& get_permitted_paths() const {
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return permitted_paths_;
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}
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void set_permitted_paths(std::vector<std::string>&& permitted_paths) {
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permitted_paths_ = permitted_paths;
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}
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soinfo::soinfo_list_t& soinfo_list() { return soinfo_list_; }
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// For isolated namespaces - checks if the file is on the search path;
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// always returns true for not isolated namespace.
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bool is_accessible(const std::string& path);
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private:
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const char* name_;
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bool is_isolated_;
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std::vector<std::string> ld_library_paths_;
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std::vector<std::string> default_library_paths_;
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std::vector<std::string> permitted_paths_;
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soinfo::soinfo_list_t soinfo_list_;
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DISALLOW_COPY_AND_ASSIGN(android_namespace_t);
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};
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android_namespace_t g_default_namespace;
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android_namespace_t* g_anonymous_namespace = &g_default_namespace;
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static ElfW(Addr) get_elf_exec_load_bias(const ElfW(Ehdr)* elf);
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static LinkerTypeAllocator<soinfo> g_soinfo_allocator;
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static LinkerTypeAllocator<LinkedListEntry<soinfo>> g_soinfo_links_allocator;
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static LinkerTypeAllocator<android_namespace_t> g_namespace_allocator;
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static soinfo* solist;
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static soinfo* sonext;
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static soinfo* somain; // main process, always the one after libdl_info
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static const char* const kDefaultLdPaths[] = {
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#if defined(__LP64__)
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"/system/lib64",
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"/vendor/lib64",
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#else
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"/system/lib",
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"/vendor/lib",
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#endif
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nullptr
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};
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static const char* const kAsanDefaultLdPaths[] = {
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#if defined(__LP64__)
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"/data/lib64",
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"/system/lib64",
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"/data/vendor/lib64",
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"/vendor/lib64",
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#else
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"/data/lib",
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"/system/lib",
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"/data/vendor/lib",
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"/vendor/lib",
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#endif
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nullptr
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};
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static bool is_system_library(const std::string& realpath) {
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for (const auto& dir : g_default_namespace.get_default_library_paths()) {
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if (file_is_in_dir(realpath, dir)) {
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return true;
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}
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}
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return false;
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}
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// TODO(dimitry): This is workaround for http://b/26394120 - it will be removed before the release
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#if defined(__LP64__)
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static const char* const kSystemLibDir = "/system/lib64";
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#else
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static const char* const kSystemLibDir = "/system/lib";
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#endif
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static std::string dirname(const char *path);
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static bool is_greylisted(const char* name, const soinfo* needed_by) {
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static const char* const kLibraryGreyList[] = {
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"libandroid_runtime.so",
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"libbinder.so",
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"libcrypto.so",
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"libcutils.so",
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"libmedia.so",
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"libnativehelper.so",
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"libskia.so",
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"libssl.so",
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"libstagefright.so",
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"libsqlite.so",
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"libui.so",
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"libutils.so",
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nullptr
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};
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// limit greylisting to apps targeting sdk version 23 and below
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if (get_application_target_sdk_version() > 23) {
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return false;
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}
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// if the library needed by a system library - implicitly assume it
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// is greylisted
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if (needed_by != nullptr && is_system_library(needed_by->get_realpath())) {
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return true;
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}
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// if this is an absolute path - make sure it points to /system/lib(64)
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if (name[0] == '/' && dirname(name) == kSystemLibDir) {
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// and reduce the path to basename
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name = basename(name);
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}
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for (size_t i = 0; kLibraryGreyList[i] != nullptr; ++i) {
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if (strcmp(name, kLibraryGreyList[i]) == 0) {
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return true;
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}
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}
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return false;
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}
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// END OF WORKAROUND
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static const ElfW(Versym) kVersymNotNeeded = 0;
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static const ElfW(Versym) kVersymGlobal = 1;
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static const char* const* g_default_ld_paths;
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static std::vector<std::string> g_ld_preload_names;
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static std::vector<soinfo*> g_ld_preloads;
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static bool g_public_namespace_initialized;
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static soinfo::soinfo_list_t g_public_namespace;
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__LIBC_HIDDEN__ int g_ld_debug_verbosity;
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__LIBC_HIDDEN__ abort_msg_t* g_abort_message = nullptr; // For debuggerd.
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static std::string dirname(const char *path) {
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const char* last_slash = strrchr(path, '/');
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if (last_slash == path) return "/";
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else if (last_slash == nullptr) return ".";
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else
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return std::string(path, last_slash - path);
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}
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#if STATS
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struct linker_stats_t {
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int count[kRelocMax];
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};
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static linker_stats_t linker_stats;
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void count_relocation(RelocationKind kind) {
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++linker_stats.count[kind];
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}
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#else
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void count_relocation(RelocationKind) {
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}
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#endif
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#if COUNT_PAGES
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uint32_t bitmask[4096];
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#endif
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static char __linker_dl_err_buf[768];
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char* linker_get_error_buffer() {
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return &__linker_dl_err_buf[0];
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}
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size_t linker_get_error_buffer_size() {
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return sizeof(__linker_dl_err_buf);
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}
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// This function is an empty stub where GDB locates a breakpoint to get notified
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// about linker activity.
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extern "C"
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void __attribute__((noinline)) __attribute__((visibility("default"))) rtld_db_dlactivity();
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static pthread_mutex_t g__r_debug_mutex = PTHREAD_MUTEX_INITIALIZER;
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static r_debug _r_debug =
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{1, nullptr, reinterpret_cast<uintptr_t>(&rtld_db_dlactivity), r_debug::RT_CONSISTENT, 0};
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static link_map* r_debug_tail = 0;
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static void insert_soinfo_into_debug_map(soinfo* info) {
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// Copy the necessary fields into the debug structure.
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link_map* map = &(info->link_map_head);
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map->l_addr = info->load_bias;
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// link_map l_name field is not const.
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map->l_name = const_cast<char*>(info->get_realpath());
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map->l_ld = info->dynamic;
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// Stick the new library at the end of the list.
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// gdb tends to care more about libc than it does
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// about leaf libraries, and ordering it this way
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// reduces the back-and-forth over the wire.
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if (r_debug_tail) {
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r_debug_tail->l_next = map;
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map->l_prev = r_debug_tail;
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map->l_next = 0;
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} else {
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_r_debug.r_map = map;
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map->l_prev = 0;
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map->l_next = 0;
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}
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r_debug_tail = map;
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}
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static void remove_soinfo_from_debug_map(soinfo* info) {
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link_map* map = &(info->link_map_head);
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if (r_debug_tail == map) {
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r_debug_tail = map->l_prev;
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}
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if (map->l_prev) {
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map->l_prev->l_next = map->l_next;
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}
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if (map->l_next) {
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map->l_next->l_prev = map->l_prev;
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}
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}
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static void notify_gdb_of_load(soinfo* info) {
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if (info->is_main_executable()) {
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// GDB already knows about the main executable
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return;
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}
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ScopedPthreadMutexLocker locker(&g__r_debug_mutex);
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_r_debug.r_state = r_debug::RT_ADD;
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rtld_db_dlactivity();
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insert_soinfo_into_debug_map(info);
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_r_debug.r_state = r_debug::RT_CONSISTENT;
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rtld_db_dlactivity();
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}
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static void notify_gdb_of_unload(soinfo* info) {
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if (info->is_main_executable()) {
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// GDB already knows about the main executable
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return;
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}
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ScopedPthreadMutexLocker locker(&g__r_debug_mutex);
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_r_debug.r_state = r_debug::RT_DELETE;
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rtld_db_dlactivity();
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remove_soinfo_from_debug_map(info);
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_r_debug.r_state = r_debug::RT_CONSISTENT;
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rtld_db_dlactivity();
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}
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void notify_gdb_of_libraries() {
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_r_debug.r_state = r_debug::RT_ADD;
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rtld_db_dlactivity();
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_r_debug.r_state = r_debug::RT_CONSISTENT;
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rtld_db_dlactivity();
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}
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bool android_namespace_t::is_accessible(const std::string& file) {
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if (!is_isolated_) {
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return true;
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}
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for (const auto& dir : ld_library_paths_) {
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if (file_is_in_dir(file, dir)) {
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return true;
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}
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}
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for (const auto& dir : default_library_paths_) {
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if (file_is_in_dir(file, dir)) {
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return true;
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}
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}
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for (const auto& dir : permitted_paths_) {
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if (file_is_under_dir(file, dir)) {
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return true;
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}
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}
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return false;
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}
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LinkedListEntry<soinfo>* SoinfoListAllocator::alloc() {
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return g_soinfo_links_allocator.alloc();
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}
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void SoinfoListAllocator::free(LinkedListEntry<soinfo>* entry) {
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g_soinfo_links_allocator.free(entry);
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}
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static soinfo* soinfo_alloc(android_namespace_t* ns, const char* name,
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struct stat* file_stat, off64_t file_offset,
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uint32_t rtld_flags) {
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if (strlen(name) >= PATH_MAX) {
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DL_ERR("library name \"%s\" too long", name);
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return nullptr;
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}
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soinfo* si = new (g_soinfo_allocator.alloc()) soinfo(ns, name, file_stat,
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file_offset, rtld_flags);
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sonext->next = si;
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sonext = si;
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ns->soinfo_list().push_back(si);
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TRACE("name %s: allocated soinfo @ %p", name, si);
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return si;
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}
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static void soinfo_free(soinfo* si) {
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if (si == nullptr) {
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return;
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}
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if (si->base != 0 && si->size != 0) {
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if (!si->is_mapped_by_caller()) {
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munmap(reinterpret_cast<void*>(si->base), si->size);
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} else {
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// remap the region as PROT_NONE, MAP_ANONYMOUS | MAP_NORESERVE
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mmap(reinterpret_cast<void*>(si->base), si->size, PROT_NONE,
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MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS | MAP_NORESERVE, -1, 0);
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}
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}
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soinfo *prev = nullptr, *trav;
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TRACE("name %s: freeing soinfo @ %p", si->get_realpath(), si);
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for (trav = solist; trav != nullptr; trav = trav->next) {
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if (trav == si) {
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break;
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}
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prev = trav;
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}
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if (trav == nullptr) {
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// si was not in solist
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DL_ERR("name \"%s\"@%p is not in solist!", si->get_realpath(), si);
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return;
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}
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// clear links to/from si
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si->remove_all_links();
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// prev will never be null, because the first entry in solist is
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// always the static libdl_info.
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prev->next = si->next;
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if (si == sonext) {
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sonext = prev;
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}
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// remove from the namespace
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si->get_namespace()->soinfo_list().remove_if([&](soinfo* candidate) {
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return si == candidate;
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});
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si->~soinfo();
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g_soinfo_allocator.free(si);
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}
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|
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// For every path element this function checks of it exists, and is a directory,
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// and normalizes it:
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// 1. For regular path it converts it to realpath()
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// 2. For path in a zip file it uses realpath on the zipfile
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// normalizes entry name by calling normalize_path function.
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static void resolve_paths(std::vector<std::string>& paths,
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std::vector<std::string>* resolved_paths) {
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resolved_paths->clear();
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for (const auto& path : paths) {
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char resolved_path[PATH_MAX];
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const char* original_path = path.c_str();
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if (realpath(original_path, resolved_path) != nullptr) {
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struct stat s;
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if (stat(resolved_path, &s) == 0) {
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if (S_ISDIR(s.st_mode)) {
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resolved_paths->push_back(resolved_path);
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} else {
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DL_WARN("Warning: \"%s\" is not a directory (excluding from path)", resolved_path);
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continue;
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}
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} else {
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DL_WARN("Warning: cannot stat file \"%s\": %s", resolved_path, strerror(errno));
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continue;
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}
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} else {
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std::string zip_path;
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std::string entry_path;
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std::string normalized_path;
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|
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if (!normalize_path(original_path, &normalized_path)) {
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DL_WARN("Warning: unable to normalize \"%s\"", original_path);
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continue;
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}
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if (parse_zip_path(normalized_path.c_str(), &zip_path, &entry_path)) {
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if (realpath(zip_path.c_str(), resolved_path) == nullptr) {
|
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DL_WARN("Warning: unable to resolve \"%s\": %s", zip_path.c_str(), strerror(errno));
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continue;
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}
|
|
|
|
ZipArchiveHandle handle = nullptr;
|
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if (OpenArchive(resolved_path, &handle) != 0) {
|
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DL_WARN("Warning: unable to open zip archive: %s", resolved_path);
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continue;
|
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}
|
|
|
|
// Check if zip-file has a dir with entry_path name
|
|
void* cookie = nullptr;
|
|
std::string prefix_str = entry_path + "/";
|
|
ZipString prefix(prefix_str.c_str());
|
|
|
|
ZipEntry out_data;
|
|
ZipString out_name;
|
|
|
|
int32_t error_code;
|
|
|
|
if ((error_code = StartIteration(handle, &cookie, &prefix, nullptr)) != 0) {
|
|
DL_WARN("Unable to iterate over zip-archive entries \"%s\";"
|
|
" error code: %d", zip_path.c_str(), error_code);
|
|
continue;
|
|
}
|
|
|
|
if (Next(cookie, &out_data, &out_name) != 0) {
|
|
DL_WARN("Unable to find entries starting with \"%s\" in \"%s\"",
|
|
prefix_str.c_str(), zip_path.c_str());
|
|
continue;
|
|
}
|
|
|
|
auto zip_guard = make_scope_guard([&]() {
|
|
if (cookie != nullptr) {
|
|
EndIteration(cookie);
|
|
}
|
|
CloseArchive(handle);
|
|
});
|
|
|
|
resolved_paths->push_back(std::string(resolved_path) + kZipFileSeparator + entry_path);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
static void split_path(const char* path, const char* delimiters,
|
|
std::vector<std::string>* paths) {
|
|
if (path != nullptr && path[0] != 0) {
|
|
*paths = android::base::Split(path, delimiters);
|
|
}
|
|
}
|
|
|
|
static void parse_path(const char* path, const char* delimiters,
|
|
std::vector<std::string>* resolved_paths) {
|
|
std::vector<std::string> paths;
|
|
split_path(path, delimiters, &paths);
|
|
resolve_paths(paths, resolved_paths);
|
|
}
|
|
|
|
static void parse_LD_LIBRARY_PATH(const char* path) {
|
|
std::vector<std::string> ld_libary_paths;
|
|
parse_path(path, ":", &ld_libary_paths);
|
|
g_default_namespace.set_ld_library_paths(std::move(ld_libary_paths));
|
|
}
|
|
|
|
void soinfo::set_dt_runpath(const char* path) {
|
|
if (!has_min_version(3)) {
|
|
return;
|
|
}
|
|
|
|
std::vector<std::string> runpaths;
|
|
|
|
split_path(path, ":", &runpaths);
|
|
|
|
std::string origin = dirname(get_realpath());
|
|
// FIXME: add $LIB and $PLATFORM.
|
|
std::pair<std::string, std::string> substs[] = {{"ORIGIN", origin}};
|
|
for (auto&& s : runpaths) {
|
|
size_t pos = 0;
|
|
while (pos < s.size()) {
|
|
pos = s.find("$", pos);
|
|
if (pos == std::string::npos) break;
|
|
for (const auto& subst : substs) {
|
|
const std::string& token = subst.first;
|
|
const std::string& replacement = subst.second;
|
|
if (s.substr(pos + 1, token.size()) == token) {
|
|
s.replace(pos, token.size() + 1, replacement);
|
|
// -1 to compensate for the ++pos below.
|
|
pos += replacement.size() - 1;
|
|
break;
|
|
} else if (s.substr(pos + 1, token.size() + 2) == "{" + token + "}") {
|
|
s.replace(pos, token.size() + 3, replacement);
|
|
pos += replacement.size() - 1;
|
|
break;
|
|
}
|
|
}
|
|
// Skip $ in case it did not match any of the known substitutions.
|
|
++pos;
|
|
}
|
|
}
|
|
|
|
resolve_paths(runpaths, &dt_runpath_);
|
|
}
|
|
|
|
static void parse_LD_PRELOAD(const char* path) {
|
|
g_ld_preload_names.clear();
|
|
if (path != nullptr) {
|
|
// We have historically supported ':' as well as ' ' in LD_PRELOAD.
|
|
g_ld_preload_names = android::base::Split(path, " :");
|
|
}
|
|
}
|
|
|
|
static bool realpath_fd(int fd, std::string* realpath) {
|
|
std::vector<char> buf(PATH_MAX), proc_self_fd(PATH_MAX);
|
|
__libc_format_buffer(&proc_self_fd[0], proc_self_fd.size(), "/proc/self/fd/%d", fd);
|
|
if (readlink(&proc_self_fd[0], &buf[0], buf.size()) == -1) {
|
|
PRINT("readlink('%s') failed: %s [fd=%d]", &proc_self_fd[0], strerror(errno), fd);
|
|
return false;
|
|
}
|
|
|
|
*realpath = &buf[0];
|
|
return true;
|
|
}
|
|
|
|
#if defined(__arm__)
|
|
|
|
// For a given PC, find the .so that it belongs to.
|
|
// Returns the base address of the .ARM.exidx section
|
|
// for that .so, and the number of 8-byte entries
|
|
// in that section (via *pcount).
|
|
//
|
|
// Intended to be called by libc's __gnu_Unwind_Find_exidx().
|
|
//
|
|
// This function is exposed via dlfcn.cpp and libdl.so.
|
|
_Unwind_Ptr dl_unwind_find_exidx(_Unwind_Ptr pc, int* pcount) {
|
|
uintptr_t addr = reinterpret_cast<uintptr_t>(pc);
|
|
|
|
for (soinfo* si = solist; si != 0; si = si->next) {
|
|
if ((addr >= si->base) && (addr < (si->base + si->size))) {
|
|
*pcount = si->ARM_exidx_count;
|
|
return reinterpret_cast<_Unwind_Ptr>(si->ARM_exidx);
|
|
}
|
|
}
|
|
*pcount = 0;
|
|
return nullptr;
|
|
}
|
|
|
|
#endif
|
|
|
|
// Here, we only have to provide a callback to iterate across all the
|
|
// loaded libraries. gcc_eh does the rest.
|
|
int do_dl_iterate_phdr(int (*cb)(dl_phdr_info* info, size_t size, void* data), void* data) {
|
|
int rv = 0;
|
|
for (soinfo* si = solist; si != nullptr; si = si->next) {
|
|
dl_phdr_info dl_info;
|
|
dl_info.dlpi_addr = si->link_map_head.l_addr;
|
|
dl_info.dlpi_name = si->link_map_head.l_name;
|
|
dl_info.dlpi_phdr = si->phdr;
|
|
dl_info.dlpi_phnum = si->phnum;
|
|
rv = cb(&dl_info, sizeof(dl_phdr_info), data);
|
|
if (rv != 0) {
|
|
break;
|
|
}
|
|
}
|
|
return rv;
|
|
}
|
|
|
|
const ElfW(Versym)* soinfo::get_versym(size_t n) const {
|
|
if (has_min_version(2) && versym_ != nullptr) {
|
|
return versym_ + n;
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
ElfW(Addr) soinfo::get_verneed_ptr() const {
|
|
if (has_min_version(2)) {
|
|
return verneed_ptr_;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
size_t soinfo::get_verneed_cnt() const {
|
|
if (has_min_version(2)) {
|
|
return verneed_cnt_;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
ElfW(Addr) soinfo::get_verdef_ptr() const {
|
|
if (has_min_version(2)) {
|
|
return verdef_ptr_;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
size_t soinfo::get_verdef_cnt() const {
|
|
if (has_min_version(2)) {
|
|
return verdef_cnt_;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
template<typename F>
|
|
static bool for_each_verdef(const soinfo* si, F functor) {
|
|
if (!si->has_min_version(2)) {
|
|
return true;
|
|
}
|
|
|
|
uintptr_t verdef_ptr = si->get_verdef_ptr();
|
|
if (verdef_ptr == 0) {
|
|
return true;
|
|
}
|
|
|
|
size_t offset = 0;
|
|
|
|
size_t verdef_cnt = si->get_verdef_cnt();
|
|
for (size_t i = 0; i<verdef_cnt; ++i) {
|
|
const ElfW(Verdef)* verdef = reinterpret_cast<ElfW(Verdef)*>(verdef_ptr + offset);
|
|
size_t verdaux_offset = offset + verdef->vd_aux;
|
|
offset += verdef->vd_next;
|
|
|
|
if (verdef->vd_version != 1) {
|
|
DL_ERR("unsupported verdef[%zd] vd_version: %d (expected 1) library: %s",
|
|
i, verdef->vd_version, si->get_realpath());
|
|
return false;
|
|
}
|
|
|
|
if ((verdef->vd_flags & VER_FLG_BASE) != 0) {
|
|
// "this is the version of the file itself. It must not be used for
|
|
// matching a symbol. It can be used to match references."
|
|
//
|
|
// http://www.akkadia.org/drepper/symbol-versioning
|
|
continue;
|
|
}
|
|
|
|
if (verdef->vd_cnt == 0) {
|
|
DL_ERR("invalid verdef[%zd] vd_cnt == 0 (version without a name)", i);
|
|
return false;
|
|
}
|
|
|
|
const ElfW(Verdaux)* verdaux = reinterpret_cast<ElfW(Verdaux)*>(verdef_ptr + verdaux_offset);
|
|
|
|
if (functor(i, verdef, verdaux) == true) {
|
|
break;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool soinfo::find_verdef_version_index(const version_info* vi, ElfW(Versym)* versym) const {
|
|
if (vi == nullptr) {
|
|
*versym = kVersymNotNeeded;
|
|
return true;
|
|
}
|
|
|
|
*versym = kVersymGlobal;
|
|
|
|
return for_each_verdef(this,
|
|
[&](size_t, const ElfW(Verdef)* verdef, const ElfW(Verdaux)* verdaux) {
|
|
if (verdef->vd_hash == vi->elf_hash &&
|
|
strcmp(vi->name, get_string(verdaux->vda_name)) == 0) {
|
|
*versym = verdef->vd_ndx;
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
);
|
|
}
|
|
|
|
bool soinfo::find_symbol_by_name(SymbolName& symbol_name,
|
|
const version_info* vi,
|
|
const ElfW(Sym)** symbol) const {
|
|
uint32_t symbol_index;
|
|
bool success =
|
|
is_gnu_hash() ?
|
|
gnu_lookup(symbol_name, vi, &symbol_index) :
|
|
elf_lookup(symbol_name, vi, &symbol_index);
|
|
|
|
if (success) {
|
|
*symbol = symbol_index == 0 ? nullptr : symtab_ + symbol_index;
|
|
}
|
|
|
|
return success;
|
|
}
|
|
|
|
static bool is_symbol_global_and_defined(const soinfo* si, const ElfW(Sym)* s) {
|
|
if (ELF_ST_BIND(s->st_info) == STB_GLOBAL ||
|
|
ELF_ST_BIND(s->st_info) == STB_WEAK) {
|
|
return s->st_shndx != SHN_UNDEF;
|
|
} else if (ELF_ST_BIND(s->st_info) != STB_LOCAL) {
|
|
DL_WARN("unexpected ST_BIND value: %d for '%s' in '%s'",
|
|
ELF_ST_BIND(s->st_info), si->get_string(s->st_name), si->get_realpath());
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static const ElfW(Versym) kVersymHiddenBit = 0x8000;
|
|
|
|
static inline bool is_versym_hidden(const ElfW(Versym)* versym) {
|
|
// the symbol is hidden if bit 15 of versym is set.
|
|
return versym != nullptr && (*versym & kVersymHiddenBit) != 0;
|
|
}
|
|
|
|
static inline bool check_symbol_version(const ElfW(Versym) verneed,
|
|
const ElfW(Versym)* verdef) {
|
|
return verneed == kVersymNotNeeded ||
|
|
verdef == nullptr ||
|
|
verneed == (*verdef & ~kVersymHiddenBit);
|
|
}
|
|
|
|
bool soinfo::gnu_lookup(SymbolName& symbol_name,
|
|
const version_info* vi,
|
|
uint32_t* symbol_index) const {
|
|
uint32_t hash = symbol_name.gnu_hash();
|
|
uint32_t h2 = hash >> gnu_shift2_;
|
|
|
|
uint32_t bloom_mask_bits = sizeof(ElfW(Addr))*8;
|
|
uint32_t word_num = (hash / bloom_mask_bits) & gnu_maskwords_;
|
|
ElfW(Addr) bloom_word = gnu_bloom_filter_[word_num];
|
|
|
|
*symbol_index = 0;
|
|
|
|
TRACE_TYPE(LOOKUP, "SEARCH %s in %s@%p (gnu)",
|
|
symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(base));
|
|
|
|
// test against bloom filter
|
|
if ((1 & (bloom_word >> (hash % bloom_mask_bits)) & (bloom_word >> (h2 % bloom_mask_bits))) == 0) {
|
|
TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
|
|
symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(base));
|
|
|
|
return true;
|
|
}
|
|
|
|
// bloom test says "probably yes"...
|
|
uint32_t n = gnu_bucket_[hash % gnu_nbucket_];
|
|
|
|
if (n == 0) {
|
|
TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
|
|
symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(base));
|
|
|
|
return true;
|
|
}
|
|
|
|
// lookup versym for the version definition in this library
|
|
// note the difference between "version is not requested" (vi == nullptr)
|
|
// and "version not found". In the first case verneed is kVersymNotNeeded
|
|
// which implies that the default version can be accepted; the second case results in
|
|
// verneed = 1 (kVersymGlobal) and implies that we should ignore versioned symbols
|
|
// for this library and consider only *global* ones.
|
|
ElfW(Versym) verneed = 0;
|
|
if (!find_verdef_version_index(vi, &verneed)) {
|
|
return false;
|
|
}
|
|
|
|
do {
|
|
ElfW(Sym)* s = symtab_ + n;
|
|
const ElfW(Versym)* verdef = get_versym(n);
|
|
// skip hidden versions when verneed == kVersymNotNeeded (0)
|
|
if (verneed == kVersymNotNeeded && is_versym_hidden(verdef)) {
|
|
continue;
|
|
}
|
|
if (((gnu_chain_[n] ^ hash) >> 1) == 0 &&
|
|
check_symbol_version(verneed, verdef) &&
|
|
strcmp(get_string(s->st_name), symbol_name.get_name()) == 0 &&
|
|
is_symbol_global_and_defined(this, s)) {
|
|
TRACE_TYPE(LOOKUP, "FOUND %s in %s (%p) %zd",
|
|
symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(s->st_value),
|
|
static_cast<size_t>(s->st_size));
|
|
*symbol_index = n;
|
|
return true;
|
|
}
|
|
} while ((gnu_chain_[n++] & 1) == 0);
|
|
|
|
TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p",
|
|
symbol_name.get_name(), get_realpath(), reinterpret_cast<void*>(base));
|
|
|
|
return true;
|
|
}
|
|
|
|
bool soinfo::elf_lookup(SymbolName& symbol_name,
|
|
const version_info* vi,
|
|
uint32_t* symbol_index) const {
|
|
uint32_t hash = symbol_name.elf_hash();
|
|
|
|
TRACE_TYPE(LOOKUP, "SEARCH %s in %s@%p h=%x(elf) %zd",
|
|
symbol_name.get_name(), get_realpath(),
|
|
reinterpret_cast<void*>(base), hash, hash % nbucket_);
|
|
|
|
ElfW(Versym) verneed = 0;
|
|
if (!find_verdef_version_index(vi, &verneed)) {
|
|
return false;
|
|
}
|
|
|
|
for (uint32_t n = bucket_[hash % nbucket_]; n != 0; n = chain_[n]) {
|
|
ElfW(Sym)* s = symtab_ + n;
|
|
const ElfW(Versym)* verdef = get_versym(n);
|
|
|
|
// skip hidden versions when verneed == 0
|
|
if (verneed == kVersymNotNeeded && is_versym_hidden(verdef)) {
|
|
continue;
|
|
}
|
|
|
|
if (check_symbol_version(verneed, verdef) &&
|
|
strcmp(get_string(s->st_name), symbol_name.get_name()) == 0 &&
|
|
is_symbol_global_and_defined(this, s)) {
|
|
TRACE_TYPE(LOOKUP, "FOUND %s in %s (%p) %zd",
|
|
symbol_name.get_name(), get_realpath(),
|
|
reinterpret_cast<void*>(s->st_value),
|
|
static_cast<size_t>(s->st_size));
|
|
*symbol_index = n;
|
|
return true;
|
|
}
|
|
}
|
|
|
|
TRACE_TYPE(LOOKUP, "NOT FOUND %s in %s@%p %x %zd",
|
|
symbol_name.get_name(), get_realpath(),
|
|
reinterpret_cast<void*>(base), hash, hash % nbucket_);
|
|
|
|
*symbol_index = 0;
|
|
return true;
|
|
}
|
|
|
|
soinfo::soinfo(android_namespace_t* ns, const char* realpath,
|
|
const struct stat* file_stat, off64_t file_offset,
|
|
int rtld_flags) {
|
|
memset(this, 0, sizeof(*this));
|
|
|
|
if (realpath != nullptr) {
|
|
realpath_ = realpath;
|
|
}
|
|
|
|
flags_ = FLAG_NEW_SOINFO;
|
|
version_ = SOINFO_VERSION;
|
|
|
|
if (file_stat != nullptr) {
|
|
this->st_dev_ = file_stat->st_dev;
|
|
this->st_ino_ = file_stat->st_ino;
|
|
this->file_offset_ = file_offset;
|
|
}
|
|
|
|
this->rtld_flags_ = rtld_flags;
|
|
this->namespace_ = ns;
|
|
}
|
|
|
|
static uint32_t calculate_elf_hash(const char* name) {
|
|
const uint8_t* name_bytes = reinterpret_cast<const uint8_t*>(name);
|
|
uint32_t h = 0, g;
|
|
|
|
while (*name_bytes) {
|
|
h = (h << 4) + *name_bytes++;
|
|
g = h & 0xf0000000;
|
|
h ^= g;
|
|
h ^= g >> 24;
|
|
}
|
|
|
|
return h;
|
|
}
|
|
|
|
uint32_t SymbolName::elf_hash() {
|
|
if (!has_elf_hash_) {
|
|
elf_hash_ = calculate_elf_hash(name_);
|
|
has_elf_hash_ = true;
|
|
}
|
|
|
|
return elf_hash_;
|
|
}
|
|
|
|
uint32_t SymbolName::gnu_hash() {
|
|
if (!has_gnu_hash_) {
|
|
uint32_t h = 5381;
|
|
const uint8_t* name = reinterpret_cast<const uint8_t*>(name_);
|
|
while (*name != 0) {
|
|
h += (h << 5) + *name++; // h*33 + c = h + h * 32 + c = h + h << 5 + c
|
|
}
|
|
|
|
gnu_hash_ = h;
|
|
has_gnu_hash_ = true;
|
|
}
|
|
|
|
return gnu_hash_;
|
|
}
|
|
|
|
bool soinfo_do_lookup(soinfo* si_from, const char* name, const version_info* vi,
|
|
soinfo** si_found_in, const soinfo::soinfo_list_t& global_group,
|
|
const soinfo::soinfo_list_t& local_group, const ElfW(Sym)** symbol) {
|
|
SymbolName symbol_name(name);
|
|
const ElfW(Sym)* s = nullptr;
|
|
|
|
/* "This element's presence in a shared object library alters the dynamic linker's
|
|
* symbol resolution algorithm for references within the library. Instead of starting
|
|
* a symbol search with the executable file, the dynamic linker starts from the shared
|
|
* object itself. If the shared object fails to supply the referenced symbol, the
|
|
* dynamic linker then searches the executable file and other shared objects as usual."
|
|
*
|
|
* http://www.sco.com/developers/gabi/2012-12-31/ch5.dynamic.html
|
|
*
|
|
* Note that this is unlikely since static linker avoids generating
|
|
* relocations for -Bsymbolic linked dynamic executables.
|
|
*/
|
|
if (si_from->has_DT_SYMBOLIC) {
|
|
DEBUG("%s: looking up %s in local scope (DT_SYMBOLIC)", si_from->get_realpath(), name);
|
|
if (!si_from->find_symbol_by_name(symbol_name, vi, &s)) {
|
|
return false;
|
|
}
|
|
|
|
if (s != nullptr) {
|
|
*si_found_in = si_from;
|
|
}
|
|
}
|
|
|
|
// 1. Look for it in global_group
|
|
if (s == nullptr) {
|
|
bool error = false;
|
|
global_group.visit([&](soinfo* global_si) {
|
|
DEBUG("%s: looking up %s in %s (from global group)",
|
|
si_from->get_realpath(), name, global_si->get_realpath());
|
|
if (!global_si->find_symbol_by_name(symbol_name, vi, &s)) {
|
|
error = true;
|
|
return false;
|
|
}
|
|
|
|
if (s != nullptr) {
|
|
*si_found_in = global_si;
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
});
|
|
|
|
if (error) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// 2. Look for it in the local group
|
|
if (s == nullptr) {
|
|
bool error = false;
|
|
local_group.visit([&](soinfo* local_si) {
|
|
if (local_si == si_from && si_from->has_DT_SYMBOLIC) {
|
|
// we already did this - skip
|
|
return true;
|
|
}
|
|
|
|
DEBUG("%s: looking up %s in %s (from local group)",
|
|
si_from->get_realpath(), name, local_si->get_realpath());
|
|
if (!local_si->find_symbol_by_name(symbol_name, vi, &s)) {
|
|
error = true;
|
|
return false;
|
|
}
|
|
|
|
if (s != nullptr) {
|
|
*si_found_in = local_si;
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
});
|
|
|
|
if (error) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
if (s != nullptr) {
|
|
TRACE_TYPE(LOOKUP, "si %s sym %s s->st_value = %p, "
|
|
"found in %s, base = %p, load bias = %p",
|
|
si_from->get_realpath(), name, reinterpret_cast<void*>(s->st_value),
|
|
(*si_found_in)->get_realpath(), reinterpret_cast<void*>((*si_found_in)->base),
|
|
reinterpret_cast<void*>((*si_found_in)->load_bias));
|
|
}
|
|
|
|
*symbol = s;
|
|
return true;
|
|
}
|
|
|
|
class ProtectedDataGuard {
|
|
public:
|
|
ProtectedDataGuard() {
|
|
if (ref_count_++ == 0) {
|
|
protect_data(PROT_READ | PROT_WRITE);
|
|
}
|
|
}
|
|
|
|
~ProtectedDataGuard() {
|
|
if (ref_count_ == 0) { // overflow
|
|
__libc_fatal("Too many nested calls to dlopen()");
|
|
}
|
|
|
|
if (--ref_count_ == 0) {
|
|
protect_data(PROT_READ);
|
|
}
|
|
}
|
|
private:
|
|
void protect_data(int protection) {
|
|
g_soinfo_allocator.protect_all(protection);
|
|
g_soinfo_links_allocator.protect_all(protection);
|
|
g_namespace_allocator.protect_all(protection);
|
|
}
|
|
|
|
static size_t ref_count_;
|
|
};
|
|
|
|
size_t ProtectedDataGuard::ref_count_ = 0;
|
|
|
|
// Each size has it's own allocator.
|
|
template<size_t size>
|
|
class SizeBasedAllocator {
|
|
public:
|
|
static void* alloc() {
|
|
return allocator_.alloc();
|
|
}
|
|
|
|
static void free(void* ptr) {
|
|
allocator_.free(ptr);
|
|
}
|
|
|
|
private:
|
|
static LinkerBlockAllocator allocator_;
|
|
};
|
|
|
|
template<size_t size>
|
|
LinkerBlockAllocator SizeBasedAllocator<size>::allocator_(size);
|
|
|
|
template<typename T>
|
|
class TypeBasedAllocator {
|
|
public:
|
|
static T* alloc() {
|
|
return reinterpret_cast<T*>(SizeBasedAllocator<sizeof(T)>::alloc());
|
|
}
|
|
|
|
static void free(T* ptr) {
|
|
SizeBasedAllocator<sizeof(T)>::free(ptr);
|
|
}
|
|
};
|
|
|
|
class LoadTask {
|
|
public:
|
|
struct deleter_t {
|
|
void operator()(LoadTask* t) {
|
|
t->~LoadTask();
|
|
TypeBasedAllocator<LoadTask>::free(t);
|
|
}
|
|
};
|
|
|
|
static deleter_t deleter;
|
|
|
|
static LoadTask* create(const char* name, soinfo* needed_by,
|
|
std::unordered_map<const soinfo*, ElfReader>* readers_map) {
|
|
LoadTask* ptr = TypeBasedAllocator<LoadTask>::alloc();
|
|
return new (ptr) LoadTask(name, needed_by, readers_map);
|
|
}
|
|
|
|
const char* get_name() const {
|
|
return name_;
|
|
}
|
|
|
|
soinfo* get_needed_by() const {
|
|
return needed_by_;
|
|
}
|
|
|
|
soinfo* get_soinfo() const {
|
|
return si_;
|
|
}
|
|
|
|
void set_soinfo(soinfo* si) {
|
|
si_ = si;
|
|
}
|
|
|
|
off64_t get_file_offset() const {
|
|
return file_offset_;
|
|
}
|
|
|
|
void set_file_offset(off64_t offset) {
|
|
file_offset_ = offset;
|
|
}
|
|
|
|
int get_fd() const {
|
|
return fd_;
|
|
}
|
|
|
|
void set_fd(int fd, bool assume_ownership) {
|
|
fd_ = fd;
|
|
close_fd_ = assume_ownership;
|
|
}
|
|
|
|
const android_dlextinfo* get_extinfo() const {
|
|
return extinfo_;
|
|
}
|
|
|
|
void set_extinfo(const android_dlextinfo* extinfo) {
|
|
extinfo_ = extinfo;
|
|
}
|
|
|
|
bool is_dt_needed() const {
|
|
return is_dt_needed_;
|
|
}
|
|
|
|
void set_dt_needed(bool is_dt_needed) {
|
|
is_dt_needed_ = is_dt_needed;
|
|
}
|
|
|
|
const ElfReader& get_elf_reader() const {
|
|
CHECK(si_ != nullptr);
|
|
return (*elf_readers_map_)[si_];
|
|
}
|
|
|
|
ElfReader& get_elf_reader() {
|
|
CHECK(si_ != nullptr);
|
|
return (*elf_readers_map_)[si_];
|
|
}
|
|
|
|
std::unordered_map<const soinfo*, ElfReader>* get_readers_map() {
|
|
return elf_readers_map_;
|
|
}
|
|
|
|
bool read(const char* realpath, off64_t file_size) {
|
|
ElfReader& elf_reader = get_elf_reader();
|
|
return elf_reader.Read(realpath, fd_, file_offset_, file_size);
|
|
}
|
|
|
|
bool load() {
|
|
ElfReader& elf_reader = get_elf_reader();
|
|
if (!elf_reader.Load(extinfo_)) {
|
|
return false;
|
|
}
|
|
|
|
si_->base = elf_reader.load_start();
|
|
si_->size = elf_reader.load_size();
|
|
si_->set_mapped_by_caller(elf_reader.is_mapped_by_caller());
|
|
si_->load_bias = elf_reader.load_bias();
|
|
si_->phnum = elf_reader.phdr_count();
|
|
si_->phdr = elf_reader.loaded_phdr();
|
|
|
|
return true;
|
|
}
|
|
|
|
private:
|
|
LoadTask(const char* name, soinfo* needed_by,
|
|
std::unordered_map<const soinfo*, ElfReader>* readers_map)
|
|
: name_(name), needed_by_(needed_by), si_(nullptr),
|
|
fd_(-1), close_fd_(false), file_offset_(0), elf_readers_map_(readers_map),
|
|
is_dt_needed_(false) {}
|
|
|
|
~LoadTask() {
|
|
if (fd_ != -1 && close_fd_) {
|
|
close(fd_);
|
|
}
|
|
}
|
|
|
|
const char* name_;
|
|
soinfo* needed_by_;
|
|
soinfo* si_;
|
|
const android_dlextinfo* extinfo_;
|
|
int fd_;
|
|
bool close_fd_;
|
|
off64_t file_offset_;
|
|
std::unordered_map<const soinfo*, ElfReader>* elf_readers_map_;
|
|
// TODO(dimitry): workaround for http://b/26394120 - will be removed before the release
|
|
bool is_dt_needed_;
|
|
// END OF WORKAROUND
|
|
|
|
DISALLOW_IMPLICIT_CONSTRUCTORS(LoadTask);
|
|
};
|
|
|
|
LoadTask::deleter_t LoadTask::deleter;
|
|
|
|
template <typename T>
|
|
using linked_list_t = LinkedList<T, TypeBasedAllocator<LinkedListEntry<T>>>;
|
|
|
|
typedef linked_list_t<soinfo> SoinfoLinkedList;
|
|
typedef linked_list_t<const char> StringLinkedList;
|
|
typedef std::vector<LoadTask*> LoadTaskList;
|
|
|
|
|
|
// This function walks down the tree of soinfo dependencies
|
|
// in breadth-first order and
|
|
// * calls action(soinfo* si) for each node, and
|
|
// * terminates walk if action returns false.
|
|
//
|
|
// walk_dependencies_tree returns false if walk was terminated
|
|
// by the action and true otherwise.
|
|
template<typename F>
|
|
static bool walk_dependencies_tree(soinfo* root_soinfos[], size_t root_soinfos_size, F action) {
|
|
SoinfoLinkedList visit_list;
|
|
SoinfoLinkedList visited;
|
|
|
|
for (size_t i = 0; i < root_soinfos_size; ++i) {
|
|
visit_list.push_back(root_soinfos[i]);
|
|
}
|
|
|
|
soinfo* si;
|
|
while ((si = visit_list.pop_front()) != nullptr) {
|
|
if (visited.contains(si)) {
|
|
continue;
|
|
}
|
|
|
|
if (!action(si)) {
|
|
return false;
|
|
}
|
|
|
|
visited.push_back(si);
|
|
|
|
si->get_children().for_each([&](soinfo* child) {
|
|
visit_list.push_back(child);
|
|
});
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
static const ElfW(Sym)* dlsym_handle_lookup(soinfo* root, soinfo* skip_until,
|
|
soinfo** found, SymbolName& symbol_name,
|
|
const version_info* vi) {
|
|
const ElfW(Sym)* result = nullptr;
|
|
bool skip_lookup = skip_until != nullptr;
|
|
|
|
walk_dependencies_tree(&root, 1, [&](soinfo* current_soinfo) {
|
|
if (skip_lookup) {
|
|
skip_lookup = current_soinfo != skip_until;
|
|
return true;
|
|
}
|
|
|
|
if (!current_soinfo->find_symbol_by_name(symbol_name, vi, &result)) {
|
|
result = nullptr;
|
|
return false;
|
|
}
|
|
|
|
if (result != nullptr) {
|
|
*found = current_soinfo;
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
});
|
|
|
|
return result;
|
|
}
|
|
|
|
static const ElfW(Sym)* dlsym_linear_lookup(android_namespace_t* ns,
|
|
const char* name,
|
|
const version_info* vi,
|
|
soinfo** found,
|
|
soinfo* caller,
|
|
void* handle);
|
|
|
|
// This is used by dlsym(3). It performs symbol lookup only within the
|
|
// specified soinfo object and its dependencies in breadth first order.
|
|
static const ElfW(Sym)* dlsym_handle_lookup(soinfo* si, soinfo** found,
|
|
const char* name, const version_info* vi) {
|
|
// According to man dlopen(3) and posix docs in the case when si is handle
|
|
// of the main executable we need to search not only in the executable and its
|
|
// dependencies but also in all libraries loaded with RTLD_GLOBAL.
|
|
//
|
|
// Since RTLD_GLOBAL is always set for the main executable and all dt_needed shared
|
|
// libraries and they are loaded in breath-first (correct) order we can just execute
|
|
// dlsym(RTLD_DEFAULT, ...); instead of doing two stage lookup.
|
|
if (si == somain) {
|
|
return dlsym_linear_lookup(&g_default_namespace, name, vi, found, nullptr, RTLD_DEFAULT);
|
|
}
|
|
|
|
SymbolName symbol_name(name);
|
|
return dlsym_handle_lookup(si, nullptr, found, symbol_name, vi);
|
|
}
|
|
|
|
/* This is used by dlsym(3) to performs a global symbol lookup. If the
|
|
start value is null (for RTLD_DEFAULT), the search starts at the
|
|
beginning of the global solist. Otherwise the search starts at the
|
|
specified soinfo (for RTLD_NEXT).
|
|
*/
|
|
static const ElfW(Sym)* dlsym_linear_lookup(android_namespace_t* ns,
|
|
const char* name,
|
|
const version_info* vi,
|
|
soinfo** found,
|
|
soinfo* caller,
|
|
void* handle) {
|
|
SymbolName symbol_name(name);
|
|
|
|
soinfo::soinfo_list_t& soinfo_list = ns->soinfo_list();
|
|
soinfo::soinfo_list_t::iterator start = soinfo_list.begin();
|
|
|
|
if (handle == RTLD_NEXT) {
|
|
if (caller == nullptr) {
|
|
return nullptr;
|
|
} else {
|
|
soinfo::soinfo_list_t::iterator it = soinfo_list.find(caller);
|
|
CHECK (it != soinfo_list.end());
|
|
start = ++it;
|
|
}
|
|
}
|
|
|
|
const ElfW(Sym)* s = nullptr;
|
|
for (soinfo::soinfo_list_t::iterator it = start, end = soinfo_list.end(); it != end; ++it) {
|
|
soinfo* si = *it;
|
|
// Do not skip RTLD_LOCAL libraries in dlsym(RTLD_DEFAULT, ...)
|
|
// if the library is opened by application with target api level <= 22
|
|
// See http://b/21565766
|
|
if ((si->get_rtld_flags() & RTLD_GLOBAL) == 0 && si->get_target_sdk_version() > 22) {
|
|
continue;
|
|
}
|
|
|
|
if (!si->find_symbol_by_name(symbol_name, vi, &s)) {
|
|
return nullptr;
|
|
}
|
|
|
|
if (s != nullptr) {
|
|
*found = si;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// If not found - use dlsym_handle_lookup for caller's
|
|
// local_group unless it is part of the global group in which
|
|
// case we already did it.
|
|
if (s == nullptr && caller != nullptr &&
|
|
(caller->get_rtld_flags() & RTLD_GLOBAL) == 0) {
|
|
return dlsym_handle_lookup(caller->get_local_group_root(),
|
|
(handle == RTLD_NEXT) ? caller : nullptr, found, symbol_name, vi);
|
|
}
|
|
|
|
if (s != nullptr) {
|
|
TRACE_TYPE(LOOKUP, "%s s->st_value = %p, found->base = %p",
|
|
name, reinterpret_cast<void*>(s->st_value), reinterpret_cast<void*>((*found)->base));
|
|
}
|
|
|
|
return s;
|
|
}
|
|
|
|
soinfo* find_containing_library(const void* p) {
|
|
ElfW(Addr) address = reinterpret_cast<ElfW(Addr)>(p);
|
|
for (soinfo* si = solist; si != nullptr; si = si->next) {
|
|
if (address >= si->base && address - si->base < si->size) {
|
|
return si;
|
|
}
|
|
}
|
|
return nullptr;
|
|
}
|
|
|
|
ElfW(Sym)* soinfo::find_symbol_by_address(const void* addr) {
|
|
return is_gnu_hash() ? gnu_addr_lookup(addr) : elf_addr_lookup(addr);
|
|
}
|
|
|
|
static bool symbol_matches_soaddr(const ElfW(Sym)* sym, ElfW(Addr) soaddr) {
|
|
return sym->st_shndx != SHN_UNDEF &&
|
|
soaddr >= sym->st_value &&
|
|
soaddr < sym->st_value + sym->st_size;
|
|
}
|
|
|
|
ElfW(Sym)* soinfo::gnu_addr_lookup(const void* addr) {
|
|
ElfW(Addr) soaddr = reinterpret_cast<ElfW(Addr)>(addr) - load_bias;
|
|
|
|
for (size_t i = 0; i < gnu_nbucket_; ++i) {
|
|
uint32_t n = gnu_bucket_[i];
|
|
|
|
if (n == 0) {
|
|
continue;
|
|
}
|
|
|
|
do {
|
|
ElfW(Sym)* sym = symtab_ + n;
|
|
if (symbol_matches_soaddr(sym, soaddr)) {
|
|
return sym;
|
|
}
|
|
} while ((gnu_chain_[n++] & 1) == 0);
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
ElfW(Sym)* soinfo::elf_addr_lookup(const void* addr) {
|
|
ElfW(Addr) soaddr = reinterpret_cast<ElfW(Addr)>(addr) - load_bias;
|
|
|
|
// Search the library's symbol table for any defined symbol which
|
|
// contains this address.
|
|
for (size_t i = 0; i < nchain_; ++i) {
|
|
ElfW(Sym)* sym = symtab_ + i;
|
|
if (symbol_matches_soaddr(sym, soaddr)) {
|
|
return sym;
|
|
}
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
class ZipArchiveCache {
|
|
public:
|
|
ZipArchiveCache() {}
|
|
~ZipArchiveCache();
|
|
|
|
bool get_or_open(const char* zip_path, ZipArchiveHandle* handle);
|
|
private:
|
|
DISALLOW_COPY_AND_ASSIGN(ZipArchiveCache);
|
|
|
|
std::unordered_map<std::string, ZipArchiveHandle> cache_;
|
|
};
|
|
|
|
bool ZipArchiveCache::get_or_open(const char* zip_path, ZipArchiveHandle* handle) {
|
|
std::string key(zip_path);
|
|
|
|
auto it = cache_.find(key);
|
|
if (it != cache_.end()) {
|
|
*handle = it->second;
|
|
return true;
|
|
}
|
|
|
|
int fd = TEMP_FAILURE_RETRY(open(zip_path, O_RDONLY | O_CLOEXEC));
|
|
if (fd == -1) {
|
|
return false;
|
|
}
|
|
|
|
if (OpenArchiveFd(fd, "", handle) != 0) {
|
|
// invalid zip-file (?)
|
|
close(fd);
|
|
return false;
|
|
}
|
|
|
|
cache_[key] = *handle;
|
|
return true;
|
|
}
|
|
|
|
ZipArchiveCache::~ZipArchiveCache() {
|
|
for (const auto& it : cache_) {
|
|
CloseArchive(it.second);
|
|
}
|
|
}
|
|
|
|
static int open_library_in_zipfile(ZipArchiveCache* zip_archive_cache,
|
|
const char* const input_path,
|
|
off64_t* file_offset, std::string* realpath) {
|
|
std::string normalized_path;
|
|
if (!normalize_path(input_path, &normalized_path)) {
|
|
return -1;
|
|
}
|
|
|
|
const char* const path = normalized_path.c_str();
|
|
TRACE("Trying zip file open from path '%s' -> normalized '%s'", input_path, path);
|
|
|
|
// Treat an '!/' separator inside a path as the separator between the name
|
|
// of the zip file on disk and the subdirectory to search within it.
|
|
// For example, if path is "foo.zip!/bar/bas/x.so", then we search for
|
|
// "bar/bas/x.so" within "foo.zip".
|
|
const char* const separator = strstr(path, kZipFileSeparator);
|
|
if (separator == nullptr) {
|
|
return -1;
|
|
}
|
|
|
|
char buf[512];
|
|
if (strlcpy(buf, path, sizeof(buf)) >= sizeof(buf)) {
|
|
PRINT("Warning: ignoring very long library path: %s", path);
|
|
return -1;
|
|
}
|
|
|
|
buf[separator - path] = '\0';
|
|
|
|
const char* zip_path = buf;
|
|
const char* file_path = &buf[separator - path + 2];
|
|
int fd = TEMP_FAILURE_RETRY(open(zip_path, O_RDONLY | O_CLOEXEC));
|
|
if (fd == -1) {
|
|
return -1;
|
|
}
|
|
|
|
ZipArchiveHandle handle;
|
|
if (!zip_archive_cache->get_or_open(zip_path, &handle)) {
|
|
// invalid zip-file (?)
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
ZipEntry entry;
|
|
|
|
if (FindEntry(handle, ZipString(file_path), &entry) != 0) {
|
|
// Entry was not found.
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
// Check if it is properly stored
|
|
if (entry.method != kCompressStored || (entry.offset % PAGE_SIZE) != 0) {
|
|
close(fd);
|
|
return -1;
|
|
}
|
|
|
|
*file_offset = entry.offset;
|
|
|
|
if (realpath_fd(fd, realpath)) {
|
|
*realpath += separator;
|
|
} else {
|
|
PRINT("warning: unable to get realpath for the library \"%s\". Will use given path.",
|
|
normalized_path.c_str());
|
|
*realpath = normalized_path;
|
|
}
|
|
|
|
return fd;
|
|
}
|
|
|
|
static bool format_path(char* buf, size_t buf_size, const char* path, const char* name) {
|
|
int n = __libc_format_buffer(buf, buf_size, "%s/%s", path, name);
|
|
if (n < 0 || n >= static_cast<int>(buf_size)) {
|
|
PRINT("Warning: ignoring very long library path: %s/%s", path, name);
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static int open_library_on_paths(ZipArchiveCache* zip_archive_cache,
|
|
const char* name, off64_t* file_offset,
|
|
const std::vector<std::string>& paths,
|
|
std::string* realpath) {
|
|
for (const auto& path : paths) {
|
|
char buf[512];
|
|
if (!format_path(buf, sizeof(buf), path.c_str(), name)) {
|
|
continue;
|
|
}
|
|
|
|
int fd = -1;
|
|
if (strstr(buf, kZipFileSeparator) != nullptr) {
|
|
fd = open_library_in_zipfile(zip_archive_cache, buf, file_offset, realpath);
|
|
}
|
|
|
|
if (fd == -1) {
|
|
fd = TEMP_FAILURE_RETRY(open(buf, O_RDONLY | O_CLOEXEC));
|
|
if (fd != -1) {
|
|
*file_offset = 0;
|
|
if (!realpath_fd(fd, realpath)) {
|
|
PRINT("warning: unable to get realpath for the library \"%s\". Will use given path.", buf);
|
|
*realpath = buf;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (fd != -1) {
|
|
return fd;
|
|
}
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
static int open_library(android_namespace_t* ns,
|
|
ZipArchiveCache* zip_archive_cache,
|
|
const char* name, soinfo *needed_by,
|
|
off64_t* file_offset, std::string* realpath) {
|
|
TRACE("[ opening %s ]", name);
|
|
|
|
// If the name contains a slash, we should attempt to open it directly and not search the paths.
|
|
if (strchr(name, '/') != nullptr) {
|
|
int fd = -1;
|
|
|
|
if (strstr(name, kZipFileSeparator) != nullptr) {
|
|
fd = open_library_in_zipfile(zip_archive_cache, name, file_offset, realpath);
|
|
}
|
|
|
|
if (fd == -1) {
|
|
fd = TEMP_FAILURE_RETRY(open(name, O_RDONLY | O_CLOEXEC));
|
|
if (fd != -1) {
|
|
*file_offset = 0;
|
|
if (!realpath_fd(fd, realpath)) {
|
|
PRINT("warning: unable to get realpath for the library \"%s\". Will use given path.", name);
|
|
*realpath = name;
|
|
}
|
|
}
|
|
}
|
|
|
|
return fd;
|
|
}
|
|
|
|
// Otherwise we try LD_LIBRARY_PATH first, and fall back to the default library path
|
|
int fd = open_library_on_paths(zip_archive_cache, name, file_offset, ns->get_ld_library_paths(), realpath);
|
|
if (fd == -1 && needed_by != nullptr) {
|
|
fd = open_library_on_paths(zip_archive_cache, name, file_offset, needed_by->get_dt_runpath(), realpath);
|
|
// Check if the library is accessible
|
|
if (fd != -1 && !ns->is_accessible(*realpath)) {
|
|
fd = -1;
|
|
}
|
|
}
|
|
|
|
if (fd == -1) {
|
|
fd = open_library_on_paths(zip_archive_cache, name, file_offset, ns->get_default_library_paths(), realpath);
|
|
}
|
|
|
|
// TODO(dimitry): workaround for http://b/26394120 - will be removed before the release
|
|
if (fd == -1 && ns != &g_default_namespace && is_greylisted(name, needed_by)) {
|
|
// try searching for it on default_namespace default_library_path
|
|
fd = open_library_on_paths(zip_archive_cache, name, file_offset,
|
|
g_default_namespace.get_default_library_paths(), realpath);
|
|
}
|
|
// END OF WORKAROUND
|
|
|
|
return fd;
|
|
}
|
|
|
|
static const char* fix_dt_needed(const char* dt_needed, const char* sopath __unused) {
|
|
#if !defined(__LP64__)
|
|
// Work around incorrect DT_NEEDED entries for old apps: http://b/21364029
|
|
if (get_application_target_sdk_version() <= 22) {
|
|
const char* bname = basename(dt_needed);
|
|
if (bname != dt_needed) {
|
|
DL_WARN("'%s' library has invalid DT_NEEDED entry '%s'", sopath, dt_needed);
|
|
add_dlwarning(sopath, "invalid DT_NEEDED entry", dt_needed);
|
|
}
|
|
|
|
return bname;
|
|
}
|
|
#endif
|
|
return dt_needed;
|
|
}
|
|
|
|
template<typename F>
|
|
static void for_each_dt_needed(const soinfo* si, F action) {
|
|
for (const ElfW(Dyn)* d = si->dynamic; d->d_tag != DT_NULL; ++d) {
|
|
if (d->d_tag == DT_NEEDED) {
|
|
action(fix_dt_needed(si->get_string(d->d_un.d_val), si->get_realpath()));
|
|
}
|
|
}
|
|
}
|
|
|
|
template<typename F>
|
|
static void for_each_dt_needed(const ElfReader& elf_reader, F action) {
|
|
for (const ElfW(Dyn)* d = elf_reader.dynamic(); d->d_tag != DT_NULL; ++d) {
|
|
if (d->d_tag == DT_NEEDED) {
|
|
action(fix_dt_needed(elf_reader.get_string(d->d_un.d_val), elf_reader.name()));
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool load_library(android_namespace_t* ns,
|
|
LoadTask* task,
|
|
LoadTaskList* load_tasks,
|
|
int rtld_flags,
|
|
const std::string& realpath) {
|
|
off64_t file_offset = task->get_file_offset();
|
|
const char* name = task->get_name();
|
|
const android_dlextinfo* extinfo = task->get_extinfo();
|
|
|
|
if ((file_offset % PAGE_SIZE) != 0) {
|
|
DL_ERR("file offset for the library \"%s\" is not page-aligned: %" PRId64, name, file_offset);
|
|
return false;
|
|
}
|
|
if (file_offset < 0) {
|
|
DL_ERR("file offset for the library \"%s\" is negative: %" PRId64, name, file_offset);
|
|
return false;
|
|
}
|
|
|
|
struct stat file_stat;
|
|
if (TEMP_FAILURE_RETRY(fstat(task->get_fd(), &file_stat)) != 0) {
|
|
DL_ERR("unable to stat file for the library \"%s\": %s", name, strerror(errno));
|
|
return false;
|
|
}
|
|
if (file_offset >= file_stat.st_size) {
|
|
DL_ERR("file offset for the library \"%s\" >= file size: %" PRId64 " >= %" PRId64,
|
|
name, file_offset, file_stat.st_size);
|
|
return false;
|
|
}
|
|
|
|
// Check for symlink and other situations where
|
|
// file can have different names, unless ANDROID_DLEXT_FORCE_LOAD is set
|
|
if (extinfo == nullptr || (extinfo->flags & ANDROID_DLEXT_FORCE_LOAD) == 0) {
|
|
auto predicate = [&](soinfo* si) {
|
|
return si->get_st_dev() != 0 &&
|
|
si->get_st_ino() != 0 &&
|
|
si->get_st_dev() == file_stat.st_dev &&
|
|
si->get_st_ino() == file_stat.st_ino &&
|
|
si->get_file_offset() == file_offset;
|
|
};
|
|
|
|
soinfo* si = ns->soinfo_list().find_if(predicate);
|
|
|
|
// check public namespace
|
|
if (si == nullptr) {
|
|
si = g_public_namespace.find_if(predicate);
|
|
if (si != nullptr) {
|
|
ns->soinfo_list().push_back(si);
|
|
}
|
|
}
|
|
|
|
if (si != nullptr) {
|
|
TRACE("library \"%s\" is already loaded under different name/path \"%s\" - "
|
|
"will return existing soinfo", name, si->get_realpath());
|
|
task->set_soinfo(si);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
if ((rtld_flags & RTLD_NOLOAD) != 0) {
|
|
DL_ERR("library \"%s\" wasn't loaded and RTLD_NOLOAD prevented it", name);
|
|
return false;
|
|
}
|
|
|
|
if (!ns->is_accessible(realpath)) {
|
|
// TODO(dimitry): workaround for http://b/26394120 - will be removed before the release
|
|
const soinfo* needed_by = task->is_dt_needed() ? task->get_needed_by() : nullptr;
|
|
if (is_greylisted(name, needed_by)) {
|
|
// print warning only if needed by non-system library
|
|
if (needed_by == nullptr || !is_system_library(needed_by->get_realpath())) {
|
|
const soinfo* needed_or_dlopened_by = task->get_needed_by();
|
|
const char* sopath = needed_or_dlopened_by == nullptr ? "(unknown)" :
|
|
needed_or_dlopened_by->get_realpath();
|
|
DL_WARN("library \"%s\" (\"%s\") needed or dlopened by \"%s\" is not accessible for the namespace \"%s\""
|
|
" - the access is temporarily granted as a workaround for http://b/26394120",
|
|
name, realpath.c_str(), sopath, ns->get_name());
|
|
add_dlwarning(sopath, "unauthorized access to", name);
|
|
}
|
|
} else {
|
|
// do not load libraries if they are not accessible for the specified namespace.
|
|
const char* needed_or_dlopened_by = task->get_needed_by() == nullptr ?
|
|
"(unknown)" :
|
|
task->get_needed_by()->get_realpath();
|
|
|
|
DL_ERR("library \"%s\" needed or dlopened by \"%s\" is not accessible for the namespace \"%s\"",
|
|
name, needed_or_dlopened_by, ns->get_name());
|
|
|
|
PRINT("library \"%s\" (\"%s\") needed or dlopened by \"%s\" is not accessible for the"
|
|
" namespace: [name=\"%s\", ld_library_paths=\"%s\", default_library_paths=\"%s\","
|
|
" permitted_paths=\"%s\"]",
|
|
name, realpath.c_str(),
|
|
needed_or_dlopened_by,
|
|
ns->get_name(),
|
|
android::base::Join(ns->get_ld_library_paths(), ':').c_str(),
|
|
android::base::Join(ns->get_default_library_paths(), ':').c_str(),
|
|
android::base::Join(ns->get_permitted_paths(), ':').c_str());
|
|
return false;
|
|
}
|
|
}
|
|
|
|
soinfo* si = soinfo_alloc(ns, realpath.c_str(), &file_stat, file_offset, rtld_flags);
|
|
if (si == nullptr) {
|
|
return false;
|
|
}
|
|
|
|
task->set_soinfo(si);
|
|
|
|
// Read the ELF header and some of the segments.
|
|
if (!task->read(realpath.c_str(), file_stat.st_size)) {
|
|
soinfo_free(si);
|
|
task->set_soinfo(nullptr);
|
|
return false;
|
|
}
|
|
|
|
// find and set DT_RUNPATH and dt_soname
|
|
// Note that these field values are temporary and are
|
|
// going to be overwritten on soinfo::prelink_image
|
|
// with values from PT_LOAD segments.
|
|
const ElfReader& elf_reader = task->get_elf_reader();
|
|
for (const ElfW(Dyn)* d = elf_reader.dynamic(); d->d_tag != DT_NULL; ++d) {
|
|
if (d->d_tag == DT_RUNPATH) {
|
|
si->set_dt_runpath(elf_reader.get_string(d->d_un.d_val));
|
|
}
|
|
if (d->d_tag == DT_SONAME) {
|
|
si->set_soname(elf_reader.get_string(d->d_un.d_val));
|
|
}
|
|
}
|
|
|
|
for_each_dt_needed(task->get_elf_reader(), [&](const char* name) {
|
|
load_tasks->push_back(LoadTask::create(name, si, task->get_readers_map()));
|
|
});
|
|
|
|
return true;
|
|
}
|
|
|
|
static bool load_library(android_namespace_t* ns,
|
|
LoadTask* task,
|
|
ZipArchiveCache* zip_archive_cache,
|
|
LoadTaskList* load_tasks,
|
|
int rtld_flags) {
|
|
const char* name = task->get_name();
|
|
soinfo* needed_by = task->get_needed_by();
|
|
const android_dlextinfo* extinfo = task->get_extinfo();
|
|
|
|
off64_t file_offset;
|
|
std::string realpath;
|
|
if (extinfo != nullptr && (extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) != 0) {
|
|
file_offset = 0;
|
|
if ((extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET) != 0) {
|
|
file_offset = extinfo->library_fd_offset;
|
|
}
|
|
|
|
if (!realpath_fd(extinfo->library_fd, &realpath)) {
|
|
PRINT("warning: unable to get realpath for the library \"%s\" by extinfo->library_fd. "
|
|
"Will use given name.", name);
|
|
realpath = name;
|
|
}
|
|
|
|
task->set_fd(extinfo->library_fd, false);
|
|
task->set_file_offset(file_offset);
|
|
return load_library(ns, task, load_tasks, rtld_flags, realpath);
|
|
}
|
|
|
|
// Open the file.
|
|
int fd = open_library(ns, zip_archive_cache, name, needed_by, &file_offset, &realpath);
|
|
if (fd == -1) {
|
|
DL_ERR("library \"%s\" not found", name);
|
|
return false;
|
|
}
|
|
|
|
task->set_fd(fd, true);
|
|
task->set_file_offset(file_offset);
|
|
|
|
return load_library(ns, task, load_tasks, rtld_flags, realpath);
|
|
}
|
|
|
|
// Returns true if library was found and false in 2 cases
|
|
// 1. (for default namespace only) The library was found but loaded under different
|
|
// target_sdk_version (*candidate != nullptr)
|
|
// 2. The library was not found by soname (*candidate is nullptr)
|
|
static bool find_loaded_library_by_soname(android_namespace_t* ns,
|
|
const char* name, soinfo** candidate) {
|
|
*candidate = nullptr;
|
|
|
|
// Ignore filename with path.
|
|
if (strchr(name, '/') != nullptr) {
|
|
return false;
|
|
}
|
|
|
|
uint32_t target_sdk_version = get_application_target_sdk_version();
|
|
|
|
return !ns->soinfo_list().visit([&](soinfo* si) {
|
|
const char* soname = si->get_soname();
|
|
if (soname != nullptr && (strcmp(name, soname) == 0)) {
|
|
// If the library was opened under different target sdk version
|
|
// skip this step and try to reopen it. The exceptions are
|
|
// "libdl.so" and global group. There is no point in skipping
|
|
// them because relocation process is going to use them
|
|
// in any case.
|
|
bool is_libdl = si == solist;
|
|
if (is_libdl || (si->get_dt_flags_1() & DF_1_GLOBAL) != 0 ||
|
|
!si->is_linked() || si->get_target_sdk_version() == target_sdk_version ||
|
|
ns != &g_default_namespace) {
|
|
*candidate = si;
|
|
return false;
|
|
} else if (*candidate == nullptr) {
|
|
// for the different sdk version in the default namespace
|
|
// remember the first library.
|
|
*candidate = si;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
});
|
|
}
|
|
|
|
static bool find_library_internal(android_namespace_t* ns,
|
|
LoadTask* task,
|
|
ZipArchiveCache* zip_archive_cache,
|
|
LoadTaskList* load_tasks,
|
|
int rtld_flags) {
|
|
soinfo* candidate;
|
|
|
|
if (find_loaded_library_by_soname(ns, task->get_name(), &candidate)) {
|
|
task->set_soinfo(candidate);
|
|
return true;
|
|
}
|
|
|
|
if (ns != &g_default_namespace) {
|
|
// check public namespace
|
|
candidate = g_public_namespace.find_if([&](soinfo* si) {
|
|
return strcmp(task->get_name(), si->get_soname()) == 0;
|
|
});
|
|
|
|
if (candidate != nullptr) {
|
|
ns->soinfo_list().push_back(candidate);
|
|
task->set_soinfo(candidate);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// Library might still be loaded, the accurate detection
|
|
// of this fact is done by load_library.
|
|
TRACE("[ '%s' find_loaded_library_by_soname returned false (*candidate=%s@%p). Trying harder...]",
|
|
task->get_name(), candidate == nullptr ? "n/a" : candidate->get_realpath(), candidate);
|
|
|
|
if (load_library(ns, task, zip_archive_cache, load_tasks, rtld_flags)) {
|
|
return true;
|
|
} else {
|
|
// In case we were unable to load the library but there
|
|
// is a candidate loaded under the same soname but different
|
|
// sdk level - return it anyways.
|
|
if (candidate != nullptr) {
|
|
task->set_soinfo(candidate);
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
static void soinfo_unload(soinfo* si);
|
|
|
|
// TODO: this is slightly unusual way to construct
|
|
// the global group for relocation. Not every RTLD_GLOBAL
|
|
// library is included in this group for backwards-compatibility
|
|
// reasons.
|
|
//
|
|
// This group consists of the main executable, LD_PRELOADs
|
|
// and libraries with the DF_1_GLOBAL flag set.
|
|
static soinfo::soinfo_list_t make_global_group(android_namespace_t* ns) {
|
|
soinfo::soinfo_list_t global_group;
|
|
ns->soinfo_list().for_each([&](soinfo* si) {
|
|
if ((si->get_dt_flags_1() & DF_1_GLOBAL) != 0) {
|
|
global_group.push_back(si);
|
|
}
|
|
});
|
|
|
|
return global_group;
|
|
}
|
|
|
|
static void shuffle(std::vector<LoadTask*>* v) {
|
|
for (size_t i = 0, size = v->size(); i < size; ++i) {
|
|
size_t n = size - i;
|
|
size_t r = arc4random_uniform(n);
|
|
std::swap((*v)[n-1], (*v)[r]);
|
|
}
|
|
}
|
|
|
|
// add_as_children - add first-level loaded libraries (i.e. library_names[], but
|
|
// not their transitive dependencies) as children of the start_with library.
|
|
// This is false when find_libraries is called for dlopen(), when newly loaded
|
|
// libraries must form a disjoint tree.
|
|
static bool find_libraries(android_namespace_t* ns,
|
|
soinfo* start_with,
|
|
const char* const library_names[],
|
|
size_t library_names_count, soinfo* soinfos[],
|
|
std::vector<soinfo*>* ld_preloads,
|
|
size_t ld_preloads_count, int rtld_flags,
|
|
const android_dlextinfo* extinfo,
|
|
bool add_as_children) {
|
|
// Step 0: prepare.
|
|
LoadTaskList load_tasks;
|
|
std::unordered_map<const soinfo*, ElfReader> readers_map;
|
|
|
|
for (size_t i = 0; i < library_names_count; ++i) {
|
|
const char* name = library_names[i];
|
|
load_tasks.push_back(LoadTask::create(name, start_with, &readers_map));
|
|
}
|
|
|
|
// Construct global_group.
|
|
soinfo::soinfo_list_t global_group = make_global_group(ns);
|
|
|
|
// If soinfos array is null allocate one on stack.
|
|
// The array is needed in case of failure; for example
|
|
// when library_names[] = {libone.so, libtwo.so} and libone.so
|
|
// is loaded correctly but libtwo.so failed for some reason.
|
|
// In this case libone.so should be unloaded on return.
|
|
// See also implementation of failure_guard below.
|
|
|
|
if (soinfos == nullptr) {
|
|
size_t soinfos_size = sizeof(soinfo*)*library_names_count;
|
|
soinfos = reinterpret_cast<soinfo**>(alloca(soinfos_size));
|
|
memset(soinfos, 0, soinfos_size);
|
|
}
|
|
|
|
// list of libraries to link - see step 2.
|
|
size_t soinfos_count = 0;
|
|
|
|
auto scope_guard = make_scope_guard([&]() {
|
|
for (LoadTask* t : load_tasks) {
|
|
LoadTask::deleter(t);
|
|
}
|
|
});
|
|
|
|
auto failure_guard = make_scope_guard([&]() {
|
|
// Housekeeping
|
|
for (size_t i = 0; i<soinfos_count; ++i) {
|
|
soinfo_unload(soinfos[i]);
|
|
}
|
|
});
|
|
|
|
ZipArchiveCache zip_archive_cache;
|
|
|
|
// Step 1: expand the list of load_tasks to include
|
|
// all DT_NEEDED libraries (do not load them just yet)
|
|
for (size_t i = 0; i<load_tasks.size(); ++i) {
|
|
LoadTask* task = load_tasks[i];
|
|
soinfo* needed_by = task->get_needed_by();
|
|
|
|
bool is_dt_needed = needed_by != nullptr && (needed_by != start_with || add_as_children);
|
|
task->set_extinfo(is_dt_needed ? nullptr : extinfo);
|
|
task->set_dt_needed(is_dt_needed);
|
|
|
|
if(!find_library_internal(ns, task, &zip_archive_cache, &load_tasks, rtld_flags)) {
|
|
return false;
|
|
}
|
|
|
|
soinfo* si = task->get_soinfo();
|
|
|
|
if (is_dt_needed) {
|
|
needed_by->add_child(si);
|
|
}
|
|
|
|
if (si->is_linked()) {
|
|
si->increment_ref_count();
|
|
}
|
|
|
|
// When ld_preloads is not null, the first
|
|
// ld_preloads_count libs are in fact ld_preloads.
|
|
if (ld_preloads != nullptr && soinfos_count < ld_preloads_count) {
|
|
ld_preloads->push_back(si);
|
|
}
|
|
|
|
if (soinfos_count < library_names_count) {
|
|
soinfos[soinfos_count++] = si;
|
|
}
|
|
}
|
|
|
|
// Step 2: Load libraries in random order (see b/24047022)
|
|
LoadTaskList load_list;
|
|
for (auto&& task : load_tasks) {
|
|
soinfo* si = task->get_soinfo();
|
|
auto pred = [&](const LoadTask* t) {
|
|
return t->get_soinfo() == si;
|
|
};
|
|
|
|
if (!si->is_linked() &&
|
|
std::find_if(load_list.begin(), load_list.end(), pred) == load_list.end() ) {
|
|
load_list.push_back(task);
|
|
}
|
|
}
|
|
shuffle(&load_list);
|
|
|
|
for (auto&& task : load_list) {
|
|
if (!task->load()) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// Step 3: pre-link all DT_NEEDED libraries in breadth first order.
|
|
for (auto&& task : load_tasks) {
|
|
soinfo* si = task->get_soinfo();
|
|
if (!si->is_linked() && !si->prelink_image()) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// Step 4: Add LD_PRELOADed libraries to the global group for
|
|
// future runs. There is no need to explicitly add them to
|
|
// the global group for this run because they are going to
|
|
// appear in the local group in the correct order.
|
|
if (ld_preloads != nullptr) {
|
|
for (auto&& si : *ld_preloads) {
|
|
si->set_dt_flags_1(si->get_dt_flags_1() | DF_1_GLOBAL);
|
|
}
|
|
}
|
|
|
|
|
|
// Step 5: link libraries.
|
|
soinfo::soinfo_list_t local_group;
|
|
walk_dependencies_tree(
|
|
(start_with != nullptr && add_as_children) ? &start_with : soinfos,
|
|
(start_with != nullptr && add_as_children) ? 1 : soinfos_count,
|
|
[&] (soinfo* si) {
|
|
local_group.push_back(si);
|
|
return true;
|
|
});
|
|
|
|
// We need to increment ref_count in case
|
|
// the root of the local group was not linked.
|
|
bool was_local_group_root_linked = local_group.front()->is_linked();
|
|
|
|
bool linked = local_group.visit([&](soinfo* si) {
|
|
if (!si->is_linked()) {
|
|
if (!si->link_image(global_group, local_group, extinfo)) {
|
|
return false;
|
|
}
|
|
si->set_linked();
|
|
}
|
|
|
|
return true;
|
|
});
|
|
|
|
if (linked) {
|
|
failure_guard.disable();
|
|
}
|
|
|
|
if (!was_local_group_root_linked) {
|
|
local_group.front()->increment_ref_count();
|
|
}
|
|
|
|
return linked;
|
|
}
|
|
|
|
static soinfo* find_library(android_namespace_t* ns,
|
|
const char* name, int rtld_flags,
|
|
const android_dlextinfo* extinfo,
|
|
soinfo* needed_by) {
|
|
soinfo* si;
|
|
|
|
if (name == nullptr) {
|
|
si = somain;
|
|
} else if (!find_libraries(ns, needed_by, &name, 1, &si, nullptr, 0, rtld_flags,
|
|
extinfo, /* add_as_children */ false)) {
|
|
return nullptr;
|
|
}
|
|
|
|
return si;
|
|
}
|
|
|
|
static void soinfo_unload(soinfo* root) {
|
|
// Note that the library can be loaded but not linked;
|
|
// in which case there is no root but we still need
|
|
// to walk the tree and unload soinfos involved.
|
|
//
|
|
// This happens on unsuccessful dlopen, when one of
|
|
// the DT_NEEDED libraries could not be linked/found.
|
|
if (root->is_linked()) {
|
|
root = root->get_local_group_root();
|
|
}
|
|
|
|
if (!root->can_unload()) {
|
|
TRACE("not unloading '%s' - the binary is flagged with NODELETE", root->get_realpath());
|
|
return;
|
|
}
|
|
|
|
size_t ref_count = root->is_linked() ? root->decrement_ref_count() : 0;
|
|
|
|
if (ref_count == 0) {
|
|
soinfo::soinfo_list_t local_unload_list;
|
|
soinfo::soinfo_list_t external_unload_list;
|
|
soinfo::soinfo_list_t depth_first_list;
|
|
depth_first_list.push_back(root);
|
|
soinfo* si = nullptr;
|
|
|
|
while ((si = depth_first_list.pop_front()) != nullptr) {
|
|
if (local_unload_list.contains(si)) {
|
|
continue;
|
|
}
|
|
|
|
local_unload_list.push_back(si);
|
|
|
|
if (si->has_min_version(0)) {
|
|
soinfo* child = nullptr;
|
|
while ((child = si->get_children().pop_front()) != nullptr) {
|
|
TRACE("%s@%p needs to unload %s@%p", si->get_realpath(), si,
|
|
child->get_realpath(), child);
|
|
|
|
if (local_unload_list.contains(child)) {
|
|
continue;
|
|
} else if (child->is_linked() && child->get_local_group_root() != root) {
|
|
external_unload_list.push_back(child);
|
|
} else {
|
|
depth_first_list.push_front(child);
|
|
}
|
|
}
|
|
} else {
|
|
#if !defined(__work_around_b_24465209__)
|
|
__libc_fatal("soinfo for \"%s\"@%p has no version", si->get_realpath(), si);
|
|
#else
|
|
PRINT("warning: soinfo for \"%s\"@%p has no version", si->get_realpath(), si);
|
|
for_each_dt_needed(si, [&] (const char* library_name) {
|
|
TRACE("deprecated (old format of soinfo): %s needs to unload %s",
|
|
si->get_realpath(), library_name);
|
|
|
|
soinfo* needed = find_library(si->get_namespace(),
|
|
library_name, RTLD_NOLOAD, nullptr, nullptr);
|
|
|
|
if (needed != nullptr) {
|
|
// Not found: for example if symlink was deleted between dlopen and dlclose
|
|
// Since we cannot really handle errors at this point - print and continue.
|
|
PRINT("warning: couldn't find %s needed by %s on unload.",
|
|
library_name, si->get_realpath());
|
|
return;
|
|
} else if (local_unload_list.contains(needed)) {
|
|
// already visited
|
|
return;
|
|
} else if (needed->is_linked() && needed->get_local_group_root() != root) {
|
|
// external group
|
|
external_unload_list.push_back(needed);
|
|
} else {
|
|
// local group
|
|
depth_first_list.push_front(needed);
|
|
}
|
|
});
|
|
#endif
|
|
}
|
|
}
|
|
|
|
local_unload_list.for_each([](soinfo* si) {
|
|
si->call_destructors();
|
|
});
|
|
|
|
while ((si = local_unload_list.pop_front()) != nullptr) {
|
|
notify_gdb_of_unload(si);
|
|
soinfo_free(si);
|
|
}
|
|
|
|
while ((si = external_unload_list.pop_front()) != nullptr) {
|
|
soinfo_unload(si);
|
|
}
|
|
} else {
|
|
TRACE("not unloading '%s' group, decrementing ref_count to %zd",
|
|
root->get_realpath(), ref_count);
|
|
}
|
|
}
|
|
|
|
static std::string symbol_display_name(const char* sym_name, const char* sym_ver) {
|
|
if (sym_ver == nullptr) {
|
|
return sym_name;
|
|
}
|
|
|
|
return std::string(sym_name) + ", version " + sym_ver;
|
|
}
|
|
|
|
void do_android_get_LD_LIBRARY_PATH(char* buffer, size_t buffer_size) {
|
|
// Use basic string manipulation calls to avoid snprintf.
|
|
// snprintf indirectly calls pthread_getspecific to get the size of a buffer.
|
|
// When debug malloc is enabled, this call returns 0. This in turn causes
|
|
// snprintf to do nothing, which causes libraries to fail to load.
|
|
// See b/17302493 for further details.
|
|
// Once the above bug is fixed, this code can be modified to use
|
|
// snprintf again.
|
|
size_t required_len = 0;
|
|
for (size_t i = 0; g_default_ld_paths[i] != nullptr; ++i) {
|
|
required_len += strlen(g_default_ld_paths[i]) + 1;
|
|
}
|
|
if (buffer_size < required_len) {
|
|
__libc_fatal("android_get_LD_LIBRARY_PATH failed, buffer too small: "
|
|
"buffer len %zu, required len %zu", buffer_size, required_len);
|
|
}
|
|
char* end = buffer;
|
|
for (size_t i = 0; g_default_ld_paths[i] != nullptr; ++i) {
|
|
if (i > 0) *end++ = ':';
|
|
end = stpcpy(end, g_default_ld_paths[i]);
|
|
}
|
|
}
|
|
|
|
void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path) {
|
|
parse_LD_LIBRARY_PATH(ld_library_path);
|
|
}
|
|
|
|
soinfo* do_dlopen(const char* name, int flags, const android_dlextinfo* extinfo,
|
|
void* caller_addr) {
|
|
soinfo* const caller = find_containing_library(caller_addr);
|
|
|
|
if ((flags & ~(RTLD_NOW|RTLD_LAZY|RTLD_LOCAL|RTLD_GLOBAL|RTLD_NODELETE|RTLD_NOLOAD)) != 0) {
|
|
DL_ERR("invalid flags to dlopen: %x", flags);
|
|
return nullptr;
|
|
}
|
|
|
|
android_namespace_t* ns = caller != nullptr ? caller->get_namespace() : g_anonymous_namespace;
|
|
|
|
if (extinfo != nullptr) {
|
|
if ((extinfo->flags & ~(ANDROID_DLEXT_VALID_FLAG_BITS)) != 0) {
|
|
DL_ERR("invalid extended flags to android_dlopen_ext: 0x%" PRIx64, extinfo->flags);
|
|
return nullptr;
|
|
}
|
|
|
|
if ((extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD) == 0 &&
|
|
(extinfo->flags & ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET) != 0) {
|
|
DL_ERR("invalid extended flag combination (ANDROID_DLEXT_USE_LIBRARY_FD_OFFSET without "
|
|
"ANDROID_DLEXT_USE_LIBRARY_FD): 0x%" PRIx64, extinfo->flags);
|
|
return nullptr;
|
|
}
|
|
|
|
if ((extinfo->flags & ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS) != 0 &&
|
|
(extinfo->flags & (ANDROID_DLEXT_RESERVED_ADDRESS | ANDROID_DLEXT_RESERVED_ADDRESS_HINT)) != 0) {
|
|
DL_ERR("invalid extended flag combination: ANDROID_DLEXT_LOAD_AT_FIXED_ADDRESS is not "
|
|
"compatible with ANDROID_DLEXT_RESERVED_ADDRESS/ANDROID_DLEXT_RESERVED_ADDRESS_HINT");
|
|
return nullptr;
|
|
}
|
|
|
|
if ((extinfo->flags & ANDROID_DLEXT_USE_NAMESPACE) != 0) {
|
|
if (extinfo->library_namespace == nullptr) {
|
|
DL_ERR("ANDROID_DLEXT_USE_NAMESPACE is set but extinfo->library_namespace is null");
|
|
return nullptr;
|
|
}
|
|
ns = extinfo->library_namespace;
|
|
}
|
|
}
|
|
|
|
ProtectedDataGuard guard;
|
|
soinfo* si = find_library(ns, name, flags, extinfo, caller);
|
|
if (si != nullptr) {
|
|
si->call_constructors();
|
|
}
|
|
|
|
return si;
|
|
}
|
|
|
|
int do_dladdr(const void* addr, Dl_info* info) {
|
|
// Determine if this address can be found in any library currently mapped.
|
|
soinfo* si = find_containing_library(addr);
|
|
if (si == nullptr) {
|
|
return 0;
|
|
}
|
|
|
|
memset(info, 0, sizeof(Dl_info));
|
|
|
|
info->dli_fname = si->get_realpath();
|
|
// Address at which the shared object is loaded.
|
|
info->dli_fbase = reinterpret_cast<void*>(si->base);
|
|
|
|
// Determine if any symbol in the library contains the specified address.
|
|
ElfW(Sym)* sym = si->find_symbol_by_address(addr);
|
|
if (sym != nullptr) {
|
|
info->dli_sname = si->get_string(sym->st_name);
|
|
info->dli_saddr = reinterpret_cast<void*>(si->resolve_symbol_address(sym));
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
bool do_dlsym(void* handle, const char* sym_name, const char* sym_ver,
|
|
void* caller_addr, void** symbol) {
|
|
#if !defined(__LP64__)
|
|
if (handle == nullptr) {
|
|
DL_ERR("dlsym failed: library handle is null");
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
if (sym_name == nullptr) {
|
|
DL_ERR("dlsym failed: symbol name is null");
|
|
return false;
|
|
}
|
|
|
|
soinfo* found = nullptr;
|
|
const ElfW(Sym)* sym = nullptr;
|
|
soinfo* caller = find_containing_library(caller_addr);
|
|
android_namespace_t* ns = caller != nullptr ? caller->get_namespace() : g_anonymous_namespace;
|
|
|
|
version_info vi_instance;
|
|
version_info* vi = nullptr;
|
|
|
|
if (sym_ver != nullptr) {
|
|
vi_instance.name = sym_ver;
|
|
vi_instance.elf_hash = calculate_elf_hash(sym_ver);
|
|
vi = &vi_instance;
|
|
}
|
|
|
|
if (handle == RTLD_DEFAULT || handle == RTLD_NEXT) {
|
|
sym = dlsym_linear_lookup(ns, sym_name, vi, &found, caller, handle);
|
|
} else {
|
|
sym = dlsym_handle_lookup(reinterpret_cast<soinfo*>(handle), &found, sym_name, vi);
|
|
}
|
|
|
|
if (sym != nullptr) {
|
|
uint32_t bind = ELF_ST_BIND(sym->st_info);
|
|
|
|
if ((bind == STB_GLOBAL || bind == STB_WEAK) && sym->st_shndx != 0) {
|
|
*symbol = reinterpret_cast<void*>(found->resolve_symbol_address(sym));
|
|
return true;
|
|
}
|
|
|
|
DL_ERR("symbol \"%s\" found but not global", symbol_display_name(sym_name, sym_ver).c_str());
|
|
return false;
|
|
}
|
|
|
|
DL_ERR("undefined symbol: %s", symbol_display_name(sym_name, sym_ver).c_str());
|
|
return false;
|
|
}
|
|
|
|
void do_dlclose(soinfo* si) {
|
|
ProtectedDataGuard guard;
|
|
soinfo_unload(si);
|
|
}
|
|
|
|
bool init_namespaces(const char* public_ns_sonames, const char* anon_ns_library_path) {
|
|
CHECK(public_ns_sonames != nullptr);
|
|
if (g_public_namespace_initialized) {
|
|
DL_ERR("public namespace has already been initialized.");
|
|
return false;
|
|
}
|
|
|
|
std::vector<std::string> sonames = android::base::Split(public_ns_sonames, ":");
|
|
|
|
ProtectedDataGuard guard;
|
|
|
|
auto failure_guard = make_scope_guard([&]() {
|
|
g_public_namespace.clear();
|
|
});
|
|
|
|
for (const auto& soname : sonames) {
|
|
soinfo* candidate = nullptr;
|
|
|
|
find_loaded_library_by_soname(&g_default_namespace, soname.c_str(), &candidate);
|
|
|
|
if (candidate == nullptr) {
|
|
DL_ERR("error initializing public namespace: \"%s\" was not found"
|
|
" in the default namespace", soname.c_str());
|
|
return false;
|
|
}
|
|
|
|
candidate->set_nodelete();
|
|
g_public_namespace.push_back(candidate);
|
|
}
|
|
|
|
g_public_namespace_initialized = true;
|
|
|
|
// create anonymous namespace
|
|
// When the caller is nullptr - create_namespace will take global group
|
|
// from the anonymous namespace, which is fine because anonymous namespace
|
|
// is still pointing to the default one.
|
|
android_namespace_t* anon_ns =
|
|
create_namespace(nullptr, "(anonymous)", nullptr, anon_ns_library_path,
|
|
ANDROID_NAMESPACE_TYPE_REGULAR, nullptr);
|
|
|
|
if (anon_ns == nullptr) {
|
|
g_public_namespace_initialized = false;
|
|
return false;
|
|
}
|
|
g_anonymous_namespace = anon_ns;
|
|
failure_guard.disable();
|
|
return true;
|
|
}
|
|
|
|
android_namespace_t* create_namespace(const void* caller_addr,
|
|
const char* name,
|
|
const char* ld_library_path,
|
|
const char* default_library_path,
|
|
uint64_t type,
|
|
const char* permitted_when_isolated_path) {
|
|
if (!g_public_namespace_initialized) {
|
|
DL_ERR("cannot create namespace: public namespace is not initialized.");
|
|
return nullptr;
|
|
}
|
|
|
|
soinfo* caller_soinfo = find_containing_library(caller_addr);
|
|
|
|
android_namespace_t* caller_ns = caller_soinfo != nullptr ?
|
|
caller_soinfo->get_namespace() :
|
|
g_anonymous_namespace;
|
|
|
|
ProtectedDataGuard guard;
|
|
std::vector<std::string> ld_library_paths;
|
|
std::vector<std::string> default_library_paths;
|
|
std::vector<std::string> permitted_paths;
|
|
|
|
parse_path(ld_library_path, ":", &ld_library_paths);
|
|
parse_path(default_library_path, ":", &default_library_paths);
|
|
parse_path(permitted_when_isolated_path, ":", &permitted_paths);
|
|
|
|
android_namespace_t* ns = new (g_namespace_allocator.alloc()) android_namespace_t();
|
|
ns->set_name(name);
|
|
ns->set_isolated((type & ANDROID_NAMESPACE_TYPE_ISOLATED) != 0);
|
|
ns->set_ld_library_paths(std::move(ld_library_paths));
|
|
ns->set_default_library_paths(std::move(default_library_paths));
|
|
ns->set_permitted_paths(std::move(permitted_paths));
|
|
|
|
if ((type & ANDROID_NAMESPACE_TYPE_SHARED) != 0) {
|
|
// If shared - clone the caller namespace
|
|
auto& soinfo_list = caller_ns->soinfo_list();
|
|
std::copy(soinfo_list.begin(), soinfo_list.end(), std::back_inserter(ns->soinfo_list()));
|
|
} else {
|
|
// If not shared - copy only the global group
|
|
auto global_group = make_global_group(caller_ns);
|
|
std::copy(global_group.begin(), global_group.end(), std::back_inserter(ns->soinfo_list()));
|
|
}
|
|
|
|
return ns;
|
|
}
|
|
|
|
static ElfW(Addr) call_ifunc_resolver(ElfW(Addr) resolver_addr) {
|
|
typedef ElfW(Addr) (*ifunc_resolver_t)(void);
|
|
ifunc_resolver_t ifunc_resolver = reinterpret_cast<ifunc_resolver_t>(resolver_addr);
|
|
ElfW(Addr) ifunc_addr = ifunc_resolver();
|
|
TRACE_TYPE(RELO, "Called ifunc_resolver@%p. The result is %p",
|
|
ifunc_resolver, reinterpret_cast<void*>(ifunc_addr));
|
|
|
|
return ifunc_addr;
|
|
}
|
|
|
|
const version_info* VersionTracker::get_version_info(ElfW(Versym) source_symver) const {
|
|
if (source_symver < 2 ||
|
|
source_symver >= version_infos.size() ||
|
|
version_infos[source_symver].name == nullptr) {
|
|
return nullptr;
|
|
}
|
|
|
|
return &version_infos[source_symver];
|
|
}
|
|
|
|
void VersionTracker::add_version_info(size_t source_index,
|
|
ElfW(Word) elf_hash,
|
|
const char* ver_name,
|
|
const soinfo* target_si) {
|
|
if (source_index >= version_infos.size()) {
|
|
version_infos.resize(source_index+1);
|
|
}
|
|
|
|
version_infos[source_index].elf_hash = elf_hash;
|
|
version_infos[source_index].name = ver_name;
|
|
version_infos[source_index].target_si = target_si;
|
|
}
|
|
|
|
bool VersionTracker::init_verneed(const soinfo* si_from) {
|
|
uintptr_t verneed_ptr = si_from->get_verneed_ptr();
|
|
|
|
if (verneed_ptr == 0) {
|
|
return true;
|
|
}
|
|
|
|
size_t verneed_cnt = si_from->get_verneed_cnt();
|
|
|
|
for (size_t i = 0, offset = 0; i<verneed_cnt; ++i) {
|
|
const ElfW(Verneed)* verneed = reinterpret_cast<ElfW(Verneed)*>(verneed_ptr + offset);
|
|
size_t vernaux_offset = offset + verneed->vn_aux;
|
|
offset += verneed->vn_next;
|
|
|
|
if (verneed->vn_version != 1) {
|
|
DL_ERR("unsupported verneed[%zd] vn_version: %d (expected 1)", i, verneed->vn_version);
|
|
return false;
|
|
}
|
|
|
|
const char* target_soname = si_from->get_string(verneed->vn_file);
|
|
// find it in dependencies
|
|
soinfo* target_si = si_from->get_children().find_if([&](const soinfo* si) {
|
|
return si->get_soname() != nullptr && strcmp(si->get_soname(), target_soname) == 0;
|
|
});
|
|
|
|
if (target_si == nullptr) {
|
|
DL_ERR("cannot find \"%s\" from verneed[%zd] in DT_NEEDED list for \"%s\"",
|
|
target_soname, i, si_from->get_realpath());
|
|
return false;
|
|
}
|
|
|
|
for (size_t j = 0; j<verneed->vn_cnt; ++j) {
|
|
const ElfW(Vernaux)* vernaux = reinterpret_cast<ElfW(Vernaux)*>(verneed_ptr + vernaux_offset);
|
|
vernaux_offset += vernaux->vna_next;
|
|
|
|
const ElfW(Word) elf_hash = vernaux->vna_hash;
|
|
const char* ver_name = si_from->get_string(vernaux->vna_name);
|
|
ElfW(Half) source_index = vernaux->vna_other;
|
|
|
|
add_version_info(source_index, elf_hash, ver_name, target_si);
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool VersionTracker::init_verdef(const soinfo* si_from) {
|
|
return for_each_verdef(si_from,
|
|
[&](size_t, const ElfW(Verdef)* verdef, const ElfW(Verdaux)* verdaux) {
|
|
add_version_info(verdef->vd_ndx, verdef->vd_hash,
|
|
si_from->get_string(verdaux->vda_name), si_from);
|
|
return false;
|
|
}
|
|
);
|
|
}
|
|
|
|
bool VersionTracker::init(const soinfo* si_from) {
|
|
if (!si_from->has_min_version(2)) {
|
|
return true;
|
|
}
|
|
|
|
return init_verneed(si_from) && init_verdef(si_from);
|
|
}
|
|
|
|
bool soinfo::lookup_version_info(const VersionTracker& version_tracker, ElfW(Word) sym,
|
|
const char* sym_name, const version_info** vi) {
|
|
const ElfW(Versym)* sym_ver_ptr = get_versym(sym);
|
|
ElfW(Versym) sym_ver = sym_ver_ptr == nullptr ? 0 : *sym_ver_ptr;
|
|
|
|
if (sym_ver != VER_NDX_LOCAL && sym_ver != VER_NDX_GLOBAL) {
|
|
*vi = version_tracker.get_version_info(sym_ver);
|
|
|
|
if (*vi == nullptr) {
|
|
DL_ERR("cannot find verneed/verdef for version index=%d "
|
|
"referenced by symbol \"%s\" at \"%s\"", sym_ver, sym_name, get_realpath());
|
|
return false;
|
|
}
|
|
} else {
|
|
// there is no version info
|
|
*vi = nullptr;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
#if !defined(__mips__)
|
|
#if defined(USE_RELA)
|
|
static ElfW(Addr) get_addend(ElfW(Rela)* rela, ElfW(Addr) reloc_addr __unused) {
|
|
return rela->r_addend;
|
|
}
|
|
#else
|
|
static ElfW(Addr) get_addend(ElfW(Rel)* rel, ElfW(Addr) reloc_addr) {
|
|
if (ELFW(R_TYPE)(rel->r_info) == R_GENERIC_RELATIVE ||
|
|
ELFW(R_TYPE)(rel->r_info) == R_GENERIC_IRELATIVE) {
|
|
return *reinterpret_cast<ElfW(Addr)*>(reloc_addr);
|
|
}
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
template<typename ElfRelIteratorT>
|
|
bool soinfo::relocate(const VersionTracker& version_tracker, ElfRelIteratorT&& rel_iterator,
|
|
const soinfo_list_t& global_group, const soinfo_list_t& local_group) {
|
|
for (size_t idx = 0; rel_iterator.has_next(); ++idx) {
|
|
const auto rel = rel_iterator.next();
|
|
if (rel == nullptr) {
|
|
return false;
|
|
}
|
|
|
|
ElfW(Word) type = ELFW(R_TYPE)(rel->r_info);
|
|
ElfW(Word) sym = ELFW(R_SYM)(rel->r_info);
|
|
|
|
ElfW(Addr) reloc = static_cast<ElfW(Addr)>(rel->r_offset + load_bias);
|
|
ElfW(Addr) sym_addr = 0;
|
|
const char* sym_name = nullptr;
|
|
ElfW(Addr) addend = get_addend(rel, reloc);
|
|
|
|
DEBUG("Processing '%s' relocation at index %zd", get_realpath(), idx);
|
|
if (type == R_GENERIC_NONE) {
|
|
continue;
|
|
}
|
|
|
|
const ElfW(Sym)* s = nullptr;
|
|
soinfo* lsi = nullptr;
|
|
|
|
if (sym != 0) {
|
|
sym_name = get_string(symtab_[sym].st_name);
|
|
const version_info* vi = nullptr;
|
|
|
|
if (!lookup_version_info(version_tracker, sym, sym_name, &vi)) {
|
|
return false;
|
|
}
|
|
|
|
if (!soinfo_do_lookup(this, sym_name, vi, &lsi, global_group, local_group, &s)) {
|
|
return false;
|
|
}
|
|
|
|
if (s == nullptr) {
|
|
// We only allow an undefined symbol if this is a weak reference...
|
|
s = &symtab_[sym];
|
|
if (ELF_ST_BIND(s->st_info) != STB_WEAK) {
|
|
DL_ERR("cannot locate symbol \"%s\" referenced by \"%s\"...", sym_name, get_realpath());
|
|
return false;
|
|
}
|
|
|
|
/* IHI0044C AAELF 4.5.1.1:
|
|
|
|
Libraries are not searched to resolve weak references.
|
|
It is not an error for a weak reference to remain unsatisfied.
|
|
|
|
During linking, the value of an undefined weak reference is:
|
|
- Zero if the relocation type is absolute
|
|
- The address of the place if the relocation is pc-relative
|
|
- The address of nominal base address if the relocation
|
|
type is base-relative.
|
|
*/
|
|
|
|
switch (type) {
|
|
case R_GENERIC_JUMP_SLOT:
|
|
case R_GENERIC_GLOB_DAT:
|
|
case R_GENERIC_RELATIVE:
|
|
case R_GENERIC_IRELATIVE:
|
|
#if defined(__aarch64__)
|
|
case R_AARCH64_ABS64:
|
|
case R_AARCH64_ABS32:
|
|
case R_AARCH64_ABS16:
|
|
#elif defined(__x86_64__)
|
|
case R_X86_64_32:
|
|
case R_X86_64_64:
|
|
#elif defined(__arm__)
|
|
case R_ARM_ABS32:
|
|
#elif defined(__i386__)
|
|
case R_386_32:
|
|
#endif
|
|
/*
|
|
* The sym_addr was initialized to be zero above, or the relocation
|
|
* code below does not care about value of sym_addr.
|
|
* No need to do anything.
|
|
*/
|
|
break;
|
|
#if defined(__x86_64__)
|
|
case R_X86_64_PC32:
|
|
sym_addr = reloc;
|
|
break;
|
|
#elif defined(__i386__)
|
|
case R_386_PC32:
|
|
sym_addr = reloc;
|
|
break;
|
|
#endif
|
|
default:
|
|
DL_ERR("unknown weak reloc type %d @ %p (%zu)", type, rel, idx);
|
|
return false;
|
|
}
|
|
} else { // We got a definition.
|
|
#if !defined(__LP64__)
|
|
// When relocating dso with text_relocation .text segment is
|
|
// not executable. We need to restore elf flags before resolving
|
|
// STT_GNU_IFUNC symbol.
|
|
bool protect_segments = has_text_relocations &&
|
|
lsi == this &&
|
|
ELF_ST_TYPE(s->st_info) == STT_GNU_IFUNC;
|
|
if (protect_segments) {
|
|
if (phdr_table_protect_segments(phdr, phnum, load_bias) < 0) {
|
|
DL_ERR("can't protect segments for \"%s\": %s",
|
|
get_realpath(), strerror(errno));
|
|
return false;
|
|
}
|
|
}
|
|
#endif
|
|
sym_addr = lsi->resolve_symbol_address(s);
|
|
#if !defined(__LP64__)
|
|
if (protect_segments) {
|
|
if (phdr_table_unprotect_segments(phdr, phnum, load_bias) < 0) {
|
|
DL_ERR("can't unprotect loadable segments for \"%s\": %s",
|
|
get_realpath(), strerror(errno));
|
|
return false;
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
count_relocation(kRelocSymbol);
|
|
}
|
|
|
|
switch (type) {
|
|
case R_GENERIC_JUMP_SLOT:
|
|
count_relocation(kRelocAbsolute);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO JMP_SLOT %16p <- %16p %s\n",
|
|
reinterpret_cast<void*>(reloc),
|
|
reinterpret_cast<void*>(sym_addr + addend), sym_name);
|
|
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) = (sym_addr + addend);
|
|
break;
|
|
case R_GENERIC_GLOB_DAT:
|
|
count_relocation(kRelocAbsolute);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO GLOB_DAT %16p <- %16p %s\n",
|
|
reinterpret_cast<void*>(reloc),
|
|
reinterpret_cast<void*>(sym_addr + addend), sym_name);
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) = (sym_addr + addend);
|
|
break;
|
|
case R_GENERIC_RELATIVE:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO RELATIVE %16p <- %16p\n",
|
|
reinterpret_cast<void*>(reloc),
|
|
reinterpret_cast<void*>(load_bias + addend));
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) = (load_bias + addend);
|
|
break;
|
|
case R_GENERIC_IRELATIVE:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO IRELATIVE %16p <- %16p\n",
|
|
reinterpret_cast<void*>(reloc),
|
|
reinterpret_cast<void*>(load_bias + addend));
|
|
{
|
|
#if !defined(__LP64__)
|
|
// When relocating dso with text_relocation .text segment is
|
|
// not executable. We need to restore elf flags for this
|
|
// particular call.
|
|
if (has_text_relocations) {
|
|
if (phdr_table_protect_segments(phdr, phnum, load_bias) < 0) {
|
|
DL_ERR("can't protect segments for \"%s\": %s",
|
|
get_realpath(), strerror(errno));
|
|
return false;
|
|
}
|
|
}
|
|
#endif
|
|
ElfW(Addr) ifunc_addr = call_ifunc_resolver(load_bias + addend);
|
|
#if !defined(__LP64__)
|
|
// Unprotect it afterwards...
|
|
if (has_text_relocations) {
|
|
if (phdr_table_unprotect_segments(phdr, phnum, load_bias) < 0) {
|
|
DL_ERR("can't unprotect loadable segments for \"%s\": %s",
|
|
get_realpath(), strerror(errno));
|
|
return false;
|
|
}
|
|
}
|
|
#endif
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) = ifunc_addr;
|
|
}
|
|
break;
|
|
|
|
#if defined(__aarch64__)
|
|
case R_AARCH64_ABS64:
|
|
count_relocation(kRelocAbsolute);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO ABS64 %16llx <- %16llx %s\n",
|
|
reloc, sym_addr + addend, sym_name);
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend;
|
|
break;
|
|
case R_AARCH64_ABS32:
|
|
count_relocation(kRelocAbsolute);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO ABS32 %16llx <- %16llx %s\n",
|
|
reloc, sym_addr + addend, sym_name);
|
|
{
|
|
const ElfW(Addr) min_value = static_cast<ElfW(Addr)>(INT32_MIN);
|
|
const ElfW(Addr) max_value = static_cast<ElfW(Addr)>(UINT32_MAX);
|
|
if ((min_value <= (sym_addr + addend)) &&
|
|
((sym_addr + addend) <= max_value)) {
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend;
|
|
} else {
|
|
DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
|
|
sym_addr + addend, min_value, max_value);
|
|
return false;
|
|
}
|
|
}
|
|
break;
|
|
case R_AARCH64_ABS16:
|
|
count_relocation(kRelocAbsolute);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO ABS16 %16llx <- %16llx %s\n",
|
|
reloc, sym_addr + addend, sym_name);
|
|
{
|
|
const ElfW(Addr) min_value = static_cast<ElfW(Addr)>(INT16_MIN);
|
|
const ElfW(Addr) max_value = static_cast<ElfW(Addr)>(UINT16_MAX);
|
|
if ((min_value <= (sym_addr + addend)) &&
|
|
((sym_addr + addend) <= max_value)) {
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) = (sym_addr + addend);
|
|
} else {
|
|
DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
|
|
sym_addr + addend, min_value, max_value);
|
|
return false;
|
|
}
|
|
}
|
|
break;
|
|
case R_AARCH64_PREL64:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO REL64 %16llx <- %16llx - %16llx %s\n",
|
|
reloc, sym_addr + addend, rel->r_offset, sym_name);
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend - rel->r_offset;
|
|
break;
|
|
case R_AARCH64_PREL32:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO REL32 %16llx <- %16llx - %16llx %s\n",
|
|
reloc, sym_addr + addend, rel->r_offset, sym_name);
|
|
{
|
|
const ElfW(Addr) min_value = static_cast<ElfW(Addr)>(INT32_MIN);
|
|
const ElfW(Addr) max_value = static_cast<ElfW(Addr)>(UINT32_MAX);
|
|
if ((min_value <= (sym_addr + addend - rel->r_offset)) &&
|
|
((sym_addr + addend - rel->r_offset) <= max_value)) {
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend - rel->r_offset;
|
|
} else {
|
|
DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
|
|
sym_addr + addend - rel->r_offset, min_value, max_value);
|
|
return false;
|
|
}
|
|
}
|
|
break;
|
|
case R_AARCH64_PREL16:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO REL16 %16llx <- %16llx - %16llx %s\n",
|
|
reloc, sym_addr + addend, rel->r_offset, sym_name);
|
|
{
|
|
const ElfW(Addr) min_value = static_cast<ElfW(Addr)>(INT16_MIN);
|
|
const ElfW(Addr) max_value = static_cast<ElfW(Addr)>(UINT16_MAX);
|
|
if ((min_value <= (sym_addr + addend - rel->r_offset)) &&
|
|
((sym_addr + addend - rel->r_offset) <= max_value)) {
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) = sym_addr + addend - rel->r_offset;
|
|
} else {
|
|
DL_ERR("0x%016llx out of range 0x%016llx to 0x%016llx",
|
|
sym_addr + addend - rel->r_offset, min_value, max_value);
|
|
return false;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case R_AARCH64_COPY:
|
|
/*
|
|
* ET_EXEC is not supported so this should not happen.
|
|
*
|
|
* http://infocenter.arm.com/help/topic/com.arm.doc.ihi0056b/IHI0056B_aaelf64.pdf
|
|
*
|
|
* Section 4.6.11 "Dynamic relocations"
|
|
* R_AARCH64_COPY may only appear in executable objects where e_type is
|
|
* set to ET_EXEC.
|
|
*/
|
|
DL_ERR("%s R_AARCH64_COPY relocations are not supported", get_realpath());
|
|
return false;
|
|
case R_AARCH64_TLS_TPREL64:
|
|
TRACE_TYPE(RELO, "RELO TLS_TPREL64 *** %16llx <- %16llx - %16llx\n",
|
|
reloc, (sym_addr + addend), rel->r_offset);
|
|
break;
|
|
case R_AARCH64_TLS_DTPREL32:
|
|
TRACE_TYPE(RELO, "RELO TLS_DTPREL32 *** %16llx <- %16llx - %16llx\n",
|
|
reloc, (sym_addr + addend), rel->r_offset);
|
|
break;
|
|
#elif defined(__x86_64__)
|
|
case R_X86_64_32:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO R_X86_64_32 %08zx <- +%08zx %s", static_cast<size_t>(reloc),
|
|
static_cast<size_t>(sym_addr), sym_name);
|
|
*reinterpret_cast<Elf32_Addr*>(reloc) = sym_addr + addend;
|
|
break;
|
|
case R_X86_64_64:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO R_X86_64_64 %08zx <- +%08zx %s", static_cast<size_t>(reloc),
|
|
static_cast<size_t>(sym_addr), sym_name);
|
|
*reinterpret_cast<Elf64_Addr*>(reloc) = sym_addr + addend;
|
|
break;
|
|
case R_X86_64_PC32:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO R_X86_64_PC32 %08zx <- +%08zx (%08zx - %08zx) %s",
|
|
static_cast<size_t>(reloc), static_cast<size_t>(sym_addr - reloc),
|
|
static_cast<size_t>(sym_addr), static_cast<size_t>(reloc), sym_name);
|
|
*reinterpret_cast<Elf32_Addr*>(reloc) = sym_addr + addend - reloc;
|
|
break;
|
|
#elif defined(__arm__)
|
|
case R_ARM_ABS32:
|
|
count_relocation(kRelocAbsolute);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO ABS %08x <- %08x %s", reloc, sym_addr, sym_name);
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
|
|
break;
|
|
case R_ARM_REL32:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO REL32 %08x <- %08x - %08x %s",
|
|
reloc, sym_addr, rel->r_offset, sym_name);
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr - rel->r_offset;
|
|
break;
|
|
case R_ARM_COPY:
|
|
/*
|
|
* ET_EXEC is not supported so this should not happen.
|
|
*
|
|
* http://infocenter.arm.com/help/topic/com.arm.doc.ihi0044d/IHI0044D_aaelf.pdf
|
|
*
|
|
* Section 4.6.1.10 "Dynamic relocations"
|
|
* R_ARM_COPY may only appear in executable objects where e_type is
|
|
* set to ET_EXEC.
|
|
*/
|
|
DL_ERR("%s R_ARM_COPY relocations are not supported", get_realpath());
|
|
return false;
|
|
#elif defined(__i386__)
|
|
case R_386_32:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO R_386_32 %08x <- +%08x %s", reloc, sym_addr, sym_name);
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) += sym_addr;
|
|
break;
|
|
case R_386_PC32:
|
|
count_relocation(kRelocRelative);
|
|
MARK(rel->r_offset);
|
|
TRACE_TYPE(RELO, "RELO R_386_PC32 %08x <- +%08x (%08x - %08x) %s",
|
|
reloc, (sym_addr - reloc), sym_addr, reloc, sym_name);
|
|
*reinterpret_cast<ElfW(Addr)*>(reloc) += (sym_addr - reloc);
|
|
break;
|
|
#endif
|
|
default:
|
|
DL_ERR("unknown reloc type %d @ %p (%zu)", type, rel, idx);
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
#endif // !defined(__mips__)
|
|
|
|
void soinfo::call_array(const char* array_name __unused, linker_function_t* functions,
|
|
size_t count, bool reverse) {
|
|
if (functions == nullptr) {
|
|
return;
|
|
}
|
|
|
|
TRACE("[ Calling %s (size %zd) @ %p for '%s' ]", array_name, count, functions, get_realpath());
|
|
|
|
int begin = reverse ? (count - 1) : 0;
|
|
int end = reverse ? -1 : count;
|
|
int step = reverse ? -1 : 1;
|
|
|
|
for (int i = begin; i != end; i += step) {
|
|
TRACE("[ %s[%d] == %p ]", array_name, i, functions[i]);
|
|
call_function("function", functions[i]);
|
|
}
|
|
|
|
TRACE("[ Done calling %s for '%s' ]", array_name, get_realpath());
|
|
}
|
|
|
|
void soinfo::call_function(const char* function_name __unused, linker_function_t function) {
|
|
if (function == nullptr || reinterpret_cast<uintptr_t>(function) == static_cast<uintptr_t>(-1)) {
|
|
return;
|
|
}
|
|
|
|
TRACE("[ Calling %s @ %p for '%s' ]", function_name, function, get_realpath());
|
|
function();
|
|
TRACE("[ Done calling %s @ %p for '%s' ]", function_name, function, get_realpath());
|
|
}
|
|
|
|
void soinfo::call_pre_init_constructors() {
|
|
// DT_PREINIT_ARRAY functions are called before any other constructors for executables,
|
|
// but ignored in a shared library.
|
|
call_array("DT_PREINIT_ARRAY", preinit_array_, preinit_array_count_, false);
|
|
}
|
|
|
|
void soinfo::call_constructors() {
|
|
if (constructors_called) {
|
|
return;
|
|
}
|
|
|
|
// We set constructors_called before actually calling the constructors, otherwise it doesn't
|
|
// protect against recursive constructor calls. One simple example of constructor recursion
|
|
// is the libc debug malloc, which is implemented in libc_malloc_debug_leak.so:
|
|
// 1. The program depends on libc, so libc's constructor is called here.
|
|
// 2. The libc constructor calls dlopen() to load libc_malloc_debug_leak.so.
|
|
// 3. dlopen() calls the constructors on the newly created
|
|
// soinfo for libc_malloc_debug_leak.so.
|
|
// 4. The debug .so depends on libc, so CallConstructors is
|
|
// called again with the libc soinfo. If it doesn't trigger the early-
|
|
// out above, the libc constructor will be called again (recursively!).
|
|
constructors_called = true;
|
|
|
|
if (!is_main_executable() && preinit_array_ != nullptr) {
|
|
// The GNU dynamic linker silently ignores these, but we warn the developer.
|
|
PRINT("\"%s\": ignoring %zd-entry DT_PREINIT_ARRAY in shared library!",
|
|
get_realpath(), preinit_array_count_);
|
|
}
|
|
|
|
get_children().for_each([] (soinfo* si) {
|
|
si->call_constructors();
|
|
});
|
|
|
|
TRACE("\"%s\": calling constructors", get_realpath());
|
|
|
|
// DT_INIT should be called before DT_INIT_ARRAY if both are present.
|
|
call_function("DT_INIT", init_func_);
|
|
call_array("DT_INIT_ARRAY", init_array_, init_array_count_, false);
|
|
}
|
|
|
|
void soinfo::call_destructors() {
|
|
if (!constructors_called) {
|
|
return;
|
|
}
|
|
TRACE("\"%s\": calling destructors", get_realpath());
|
|
|
|
// DT_FINI_ARRAY must be parsed in reverse order.
|
|
call_array("DT_FINI_ARRAY", fini_array_, fini_array_count_, true);
|
|
|
|
// DT_FINI should be called after DT_FINI_ARRAY if both are present.
|
|
call_function("DT_FINI", fini_func_);
|
|
|
|
// This is needed on second call to dlopen
|
|
// after library has been unloaded with RTLD_NODELETE
|
|
constructors_called = false;
|
|
}
|
|
|
|
void soinfo::add_child(soinfo* child) {
|
|
if (has_min_version(0)) {
|
|
child->parents_.push_back(this);
|
|
this->children_.push_back(child);
|
|
}
|
|
}
|
|
|
|
void soinfo::remove_all_links() {
|
|
if (!has_min_version(0)) {
|
|
return;
|
|
}
|
|
|
|
// 1. Untie connected soinfos from 'this'.
|
|
children_.for_each([&] (soinfo* child) {
|
|
child->parents_.remove_if([&] (const soinfo* parent) {
|
|
return parent == this;
|
|
});
|
|
});
|
|
|
|
parents_.for_each([&] (soinfo* parent) {
|
|
parent->children_.remove_if([&] (const soinfo* child) {
|
|
return child == this;
|
|
});
|
|
});
|
|
|
|
// 2. Once everything untied - clear local lists.
|
|
parents_.clear();
|
|
children_.clear();
|
|
}
|
|
|
|
dev_t soinfo::get_st_dev() const {
|
|
if (has_min_version(0)) {
|
|
return st_dev_;
|
|
}
|
|
|
|
return 0;
|
|
};
|
|
|
|
ino_t soinfo::get_st_ino() const {
|
|
if (has_min_version(0)) {
|
|
return st_ino_;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
off64_t soinfo::get_file_offset() const {
|
|
if (has_min_version(1)) {
|
|
return file_offset_;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
uint32_t soinfo::get_rtld_flags() const {
|
|
if (has_min_version(1)) {
|
|
return rtld_flags_;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
uint32_t soinfo::get_dt_flags_1() const {
|
|
if (has_min_version(1)) {
|
|
return dt_flags_1_;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void soinfo::set_dt_flags_1(uint32_t dt_flags_1) {
|
|
if (has_min_version(1)) {
|
|
if ((dt_flags_1 & DF_1_GLOBAL) != 0) {
|
|
rtld_flags_ |= RTLD_GLOBAL;
|
|
}
|
|
|
|
if ((dt_flags_1 & DF_1_NODELETE) != 0) {
|
|
rtld_flags_ |= RTLD_NODELETE;
|
|
}
|
|
|
|
dt_flags_1_ = dt_flags_1;
|
|
}
|
|
}
|
|
|
|
void soinfo::set_nodelete() {
|
|
rtld_flags_ |= RTLD_NODELETE;
|
|
}
|
|
|
|
const char* soinfo::get_realpath() const {
|
|
#if defined(__work_around_b_24465209__)
|
|
if (has_min_version(2)) {
|
|
return realpath_.c_str();
|
|
} else {
|
|
return old_name_;
|
|
}
|
|
#else
|
|
return realpath_.c_str();
|
|
#endif
|
|
}
|
|
|
|
void soinfo::set_soname(const char* soname) {
|
|
#if defined(__work_around_b_24465209__)
|
|
if (has_min_version(2)) {
|
|
soname_ = soname;
|
|
}
|
|
strlcpy(old_name_, soname_, sizeof(old_name_));
|
|
#else
|
|
soname_ = soname;
|
|
#endif
|
|
}
|
|
|
|
const char* soinfo::get_soname() const {
|
|
#if defined(__work_around_b_24465209__)
|
|
if (has_min_version(2)) {
|
|
return soname_;
|
|
} else {
|
|
return old_name_;
|
|
}
|
|
#else
|
|
return soname_;
|
|
#endif
|
|
}
|
|
|
|
// This is a return on get_children()/get_parents() if
|
|
// 'this->flags' does not have FLAG_NEW_SOINFO set.
|
|
static soinfo::soinfo_list_t g_empty_list;
|
|
|
|
soinfo::soinfo_list_t& soinfo::get_children() {
|
|
if (has_min_version(0)) {
|
|
return children_;
|
|
}
|
|
|
|
return g_empty_list;
|
|
}
|
|
|
|
const soinfo::soinfo_list_t& soinfo::get_children() const {
|
|
if (has_min_version(0)) {
|
|
return children_;
|
|
}
|
|
|
|
return g_empty_list;
|
|
}
|
|
|
|
soinfo::soinfo_list_t& soinfo::get_parents() {
|
|
if (has_min_version(0)) {
|
|
return parents_;
|
|
}
|
|
|
|
return g_empty_list;
|
|
}
|
|
|
|
static std::vector<std::string> g_empty_runpath;
|
|
|
|
const std::vector<std::string>& soinfo::get_dt_runpath() const {
|
|
if (has_min_version(3)) {
|
|
return dt_runpath_;
|
|
}
|
|
|
|
return g_empty_runpath;
|
|
}
|
|
|
|
android_namespace_t* soinfo::get_namespace() {
|
|
if (has_min_version(3)) {
|
|
return namespace_;
|
|
}
|
|
|
|
return &g_default_namespace;
|
|
}
|
|
|
|
ElfW(Addr) soinfo::resolve_symbol_address(const ElfW(Sym)* s) const {
|
|
if (ELF_ST_TYPE(s->st_info) == STT_GNU_IFUNC) {
|
|
return call_ifunc_resolver(s->st_value + load_bias);
|
|
}
|
|
|
|
return static_cast<ElfW(Addr)>(s->st_value + load_bias);
|
|
}
|
|
|
|
const char* soinfo::get_string(ElfW(Word) index) const {
|
|
if (has_min_version(1) && (index >= strtab_size_)) {
|
|
__libc_fatal("%s: strtab out of bounds error; STRSZ=%zd, name=%d",
|
|
get_realpath(), strtab_size_, index);
|
|
}
|
|
|
|
return strtab_ + index;
|
|
}
|
|
|
|
bool soinfo::is_gnu_hash() const {
|
|
return (flags_ & FLAG_GNU_HASH) != 0;
|
|
}
|
|
|
|
bool soinfo::can_unload() const {
|
|
return (get_rtld_flags() & (RTLD_NODELETE | RTLD_GLOBAL)) == 0;
|
|
}
|
|
|
|
bool soinfo::is_linked() const {
|
|
return (flags_ & FLAG_LINKED) != 0;
|
|
}
|
|
|
|
bool soinfo::is_main_executable() const {
|
|
return (flags_ & FLAG_EXE) != 0;
|
|
}
|
|
|
|
void soinfo::set_linked() {
|
|
flags_ |= FLAG_LINKED;
|
|
}
|
|
|
|
void soinfo::set_linker_flag() {
|
|
flags_ |= FLAG_LINKER;
|
|
}
|
|
|
|
void soinfo::set_main_executable() {
|
|
flags_ |= FLAG_EXE;
|
|
}
|
|
|
|
void soinfo::increment_ref_count() {
|
|
local_group_root_->ref_count_++;
|
|
}
|
|
|
|
size_t soinfo::decrement_ref_count() {
|
|
return --local_group_root_->ref_count_;
|
|
}
|
|
|
|
soinfo* soinfo::get_local_group_root() const {
|
|
return local_group_root_;
|
|
}
|
|
|
|
|
|
void soinfo::set_mapped_by_caller(bool mapped_by_caller) {
|
|
if (mapped_by_caller) {
|
|
flags_ |= FLAG_MAPPED_BY_CALLER;
|
|
} else {
|
|
flags_ &= ~FLAG_MAPPED_BY_CALLER;
|
|
}
|
|
}
|
|
|
|
bool soinfo::is_mapped_by_caller() const {
|
|
return (flags_ & FLAG_MAPPED_BY_CALLER) != 0;
|
|
}
|
|
|
|
// This function returns api-level at the time of
|
|
// dlopen/load. Note that libraries opened by system
|
|
// will always have 'current' api level.
|
|
uint32_t soinfo::get_target_sdk_version() const {
|
|
if (!has_min_version(2)) {
|
|
return __ANDROID_API__;
|
|
}
|
|
|
|
return local_group_root_->target_sdk_version_;
|
|
}
|
|
|
|
bool soinfo::prelink_image() {
|
|
/* Extract dynamic section */
|
|
ElfW(Word) dynamic_flags = 0;
|
|
phdr_table_get_dynamic_section(phdr, phnum, load_bias, &dynamic, &dynamic_flags);
|
|
|
|
/* We can't log anything until the linker is relocated */
|
|
bool relocating_linker = (flags_ & FLAG_LINKER) != 0;
|
|
if (!relocating_linker) {
|
|
INFO("[ Linking '%s' ]", get_realpath());
|
|
DEBUG("si->base = %p si->flags = 0x%08x", reinterpret_cast<void*>(base), flags_);
|
|
}
|
|
|
|
if (dynamic == nullptr) {
|
|
if (!relocating_linker) {
|
|
DL_ERR("missing PT_DYNAMIC in \"%s\"", get_realpath());
|
|
}
|
|
return false;
|
|
} else {
|
|
if (!relocating_linker) {
|
|
DEBUG("dynamic = %p", dynamic);
|
|
}
|
|
}
|
|
|
|
#if defined(__arm__)
|
|
(void) phdr_table_get_arm_exidx(phdr, phnum, load_bias,
|
|
&ARM_exidx, &ARM_exidx_count);
|
|
#endif
|
|
|
|
// Extract useful information from dynamic section.
|
|
// Note that: "Except for the DT_NULL element at the end of the array,
|
|
// and the relative order of DT_NEEDED elements, entries may appear in any order."
|
|
//
|
|
// source: http://www.sco.com/developers/gabi/1998-04-29/ch5.dynamic.html
|
|
uint32_t needed_count = 0;
|
|
for (ElfW(Dyn)* d = dynamic; d->d_tag != DT_NULL; ++d) {
|
|
DEBUG("d = %p, d[0](tag) = %p d[1](val) = %p",
|
|
d, reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
|
|
switch (d->d_tag) {
|
|
case DT_SONAME:
|
|
// this is parsed after we have strtab initialized (see below).
|
|
break;
|
|
|
|
case DT_HASH:
|
|
nbucket_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[0];
|
|
nchain_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[1];
|
|
bucket_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr + 8);
|
|
chain_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr + 8 + nbucket_ * 4);
|
|
break;
|
|
|
|
case DT_GNU_HASH:
|
|
gnu_nbucket_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[0];
|
|
// skip symndx
|
|
gnu_maskwords_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[2];
|
|
gnu_shift2_ = reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[3];
|
|
|
|
gnu_bloom_filter_ = reinterpret_cast<ElfW(Addr)*>(load_bias + d->d_un.d_ptr + 16);
|
|
gnu_bucket_ = reinterpret_cast<uint32_t*>(gnu_bloom_filter_ + gnu_maskwords_);
|
|
// amend chain for symndx = header[1]
|
|
gnu_chain_ = gnu_bucket_ + gnu_nbucket_ -
|
|
reinterpret_cast<uint32_t*>(load_bias + d->d_un.d_ptr)[1];
|
|
|
|
if (!powerof2(gnu_maskwords_)) {
|
|
DL_ERR("invalid maskwords for gnu_hash = 0x%x, in \"%s\" expecting power to two",
|
|
gnu_maskwords_, get_realpath());
|
|
return false;
|
|
}
|
|
--gnu_maskwords_;
|
|
|
|
flags_ |= FLAG_GNU_HASH;
|
|
break;
|
|
|
|
case DT_STRTAB:
|
|
strtab_ = reinterpret_cast<const char*>(load_bias + d->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_STRSZ:
|
|
strtab_size_ = d->d_un.d_val;
|
|
break;
|
|
|
|
case DT_SYMTAB:
|
|
symtab_ = reinterpret_cast<ElfW(Sym)*>(load_bias + d->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_SYMENT:
|
|
if (d->d_un.d_val != sizeof(ElfW(Sym))) {
|
|
DL_ERR("invalid DT_SYMENT: %zd in \"%s\"",
|
|
static_cast<size_t>(d->d_un.d_val), get_realpath());
|
|
return false;
|
|
}
|
|
break;
|
|
|
|
case DT_PLTREL:
|
|
#if defined(USE_RELA)
|
|
if (d->d_un.d_val != DT_RELA) {
|
|
DL_ERR("unsupported DT_PLTREL in \"%s\"; expected DT_RELA", get_realpath());
|
|
return false;
|
|
}
|
|
#else
|
|
if (d->d_un.d_val != DT_REL) {
|
|
DL_ERR("unsupported DT_PLTREL in \"%s\"; expected DT_REL", get_realpath());
|
|
return false;
|
|
}
|
|
#endif
|
|
break;
|
|
|
|
case DT_JMPREL:
|
|
#if defined(USE_RELA)
|
|
plt_rela_ = reinterpret_cast<ElfW(Rela)*>(load_bias + d->d_un.d_ptr);
|
|
#else
|
|
plt_rel_ = reinterpret_cast<ElfW(Rel)*>(load_bias + d->d_un.d_ptr);
|
|
#endif
|
|
break;
|
|
|
|
case DT_PLTRELSZ:
|
|
#if defined(USE_RELA)
|
|
plt_rela_count_ = d->d_un.d_val / sizeof(ElfW(Rela));
|
|
#else
|
|
plt_rel_count_ = d->d_un.d_val / sizeof(ElfW(Rel));
|
|
#endif
|
|
break;
|
|
|
|
case DT_PLTGOT:
|
|
#if defined(__mips__)
|
|
// Used by mips and mips64.
|
|
plt_got_ = reinterpret_cast<ElfW(Addr)**>(load_bias + d->d_un.d_ptr);
|
|
#endif
|
|
// Ignore for other platforms... (because RTLD_LAZY is not supported)
|
|
break;
|
|
|
|
case DT_DEBUG:
|
|
// Set the DT_DEBUG entry to the address of _r_debug for GDB
|
|
// if the dynamic table is writable
|
|
// FIXME: not working currently for N64
|
|
// The flags for the LOAD and DYNAMIC program headers do not agree.
|
|
// The LOAD section containing the dynamic table has been mapped as
|
|
// read-only, but the DYNAMIC header claims it is writable.
|
|
#if !(defined(__mips__) && defined(__LP64__))
|
|
if ((dynamic_flags & PF_W) != 0) {
|
|
d->d_un.d_val = reinterpret_cast<uintptr_t>(&_r_debug);
|
|
}
|
|
#endif
|
|
break;
|
|
#if defined(USE_RELA)
|
|
case DT_RELA:
|
|
rela_ = reinterpret_cast<ElfW(Rela)*>(load_bias + d->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_RELASZ:
|
|
rela_count_ = d->d_un.d_val / sizeof(ElfW(Rela));
|
|
break;
|
|
|
|
case DT_ANDROID_RELA:
|
|
android_relocs_ = reinterpret_cast<uint8_t*>(load_bias + d->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_ANDROID_RELASZ:
|
|
android_relocs_size_ = d->d_un.d_val;
|
|
break;
|
|
|
|
case DT_ANDROID_REL:
|
|
DL_ERR("unsupported DT_ANDROID_REL in \"%s\"", get_realpath());
|
|
return false;
|
|
|
|
case DT_ANDROID_RELSZ:
|
|
DL_ERR("unsupported DT_ANDROID_RELSZ in \"%s\"", get_realpath());
|
|
return false;
|
|
|
|
case DT_RELAENT:
|
|
if (d->d_un.d_val != sizeof(ElfW(Rela))) {
|
|
DL_ERR("invalid DT_RELAENT: %zd", static_cast<size_t>(d->d_un.d_val));
|
|
return false;
|
|
}
|
|
break;
|
|
|
|
// ignored (see DT_RELCOUNT comments for details)
|
|
case DT_RELACOUNT:
|
|
break;
|
|
|
|
case DT_REL:
|
|
DL_ERR("unsupported DT_REL in \"%s\"", get_realpath());
|
|
return false;
|
|
|
|
case DT_RELSZ:
|
|
DL_ERR("unsupported DT_RELSZ in \"%s\"", get_realpath());
|
|
return false;
|
|
|
|
#else
|
|
case DT_REL:
|
|
rel_ = reinterpret_cast<ElfW(Rel)*>(load_bias + d->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_RELSZ:
|
|
rel_count_ = d->d_un.d_val / sizeof(ElfW(Rel));
|
|
break;
|
|
|
|
case DT_RELENT:
|
|
if (d->d_un.d_val != sizeof(ElfW(Rel))) {
|
|
DL_ERR("invalid DT_RELENT: %zd", static_cast<size_t>(d->d_un.d_val));
|
|
return false;
|
|
}
|
|
break;
|
|
|
|
case DT_ANDROID_REL:
|
|
android_relocs_ = reinterpret_cast<uint8_t*>(load_bias + d->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_ANDROID_RELSZ:
|
|
android_relocs_size_ = d->d_un.d_val;
|
|
break;
|
|
|
|
case DT_ANDROID_RELA:
|
|
DL_ERR("unsupported DT_ANDROID_RELA in \"%s\"", get_realpath());
|
|
return false;
|
|
|
|
case DT_ANDROID_RELASZ:
|
|
DL_ERR("unsupported DT_ANDROID_RELASZ in \"%s\"", get_realpath());
|
|
return false;
|
|
|
|
// "Indicates that all RELATIVE relocations have been concatenated together,
|
|
// and specifies the RELATIVE relocation count."
|
|
//
|
|
// TODO: Spec also mentions that this can be used to optimize relocation process;
|
|
// Not currently used by bionic linker - ignored.
|
|
case DT_RELCOUNT:
|
|
break;
|
|
|
|
case DT_RELA:
|
|
DL_ERR("unsupported DT_RELA in \"%s\"", get_realpath());
|
|
return false;
|
|
|
|
case DT_RELASZ:
|
|
DL_ERR("unsupported DT_RELASZ in \"%s\"", get_realpath());
|
|
return false;
|
|
|
|
#endif
|
|
case DT_INIT:
|
|
init_func_ = reinterpret_cast<linker_function_t>(load_bias + d->d_un.d_ptr);
|
|
DEBUG("%s constructors (DT_INIT) found at %p", get_realpath(), init_func_);
|
|
break;
|
|
|
|
case DT_FINI:
|
|
fini_func_ = reinterpret_cast<linker_function_t>(load_bias + d->d_un.d_ptr);
|
|
DEBUG("%s destructors (DT_FINI) found at %p", get_realpath(), fini_func_);
|
|
break;
|
|
|
|
case DT_INIT_ARRAY:
|
|
init_array_ = reinterpret_cast<linker_function_t*>(load_bias + d->d_un.d_ptr);
|
|
DEBUG("%s constructors (DT_INIT_ARRAY) found at %p", get_realpath(), init_array_);
|
|
break;
|
|
|
|
case DT_INIT_ARRAYSZ:
|
|
init_array_count_ = static_cast<uint32_t>(d->d_un.d_val) / sizeof(ElfW(Addr));
|
|
break;
|
|
|
|
case DT_FINI_ARRAY:
|
|
fini_array_ = reinterpret_cast<linker_function_t*>(load_bias + d->d_un.d_ptr);
|
|
DEBUG("%s destructors (DT_FINI_ARRAY) found at %p", get_realpath(), fini_array_);
|
|
break;
|
|
|
|
case DT_FINI_ARRAYSZ:
|
|
fini_array_count_ = static_cast<uint32_t>(d->d_un.d_val) / sizeof(ElfW(Addr));
|
|
break;
|
|
|
|
case DT_PREINIT_ARRAY:
|
|
preinit_array_ = reinterpret_cast<linker_function_t*>(load_bias + d->d_un.d_ptr);
|
|
DEBUG("%s constructors (DT_PREINIT_ARRAY) found at %p", get_realpath(), preinit_array_);
|
|
break;
|
|
|
|
case DT_PREINIT_ARRAYSZ:
|
|
preinit_array_count_ = static_cast<uint32_t>(d->d_un.d_val) / sizeof(ElfW(Addr));
|
|
break;
|
|
|
|
case DT_TEXTREL:
|
|
#if defined(__LP64__)
|
|
DL_ERR("text relocations (DT_TEXTREL) found in 64-bit ELF file \"%s\"", get_realpath());
|
|
return false;
|
|
#else
|
|
has_text_relocations = true;
|
|
break;
|
|
#endif
|
|
|
|
case DT_SYMBOLIC:
|
|
has_DT_SYMBOLIC = true;
|
|
break;
|
|
|
|
case DT_NEEDED:
|
|
++needed_count;
|
|
break;
|
|
|
|
case DT_FLAGS:
|
|
if (d->d_un.d_val & DF_TEXTREL) {
|
|
#if defined(__LP64__)
|
|
DL_ERR("text relocations (DF_TEXTREL) found in 64-bit ELF file \"%s\"", get_realpath());
|
|
return false;
|
|
#else
|
|
has_text_relocations = true;
|
|
#endif
|
|
}
|
|
if (d->d_un.d_val & DF_SYMBOLIC) {
|
|
has_DT_SYMBOLIC = true;
|
|
}
|
|
break;
|
|
|
|
case DT_FLAGS_1:
|
|
set_dt_flags_1(d->d_un.d_val);
|
|
|
|
if ((d->d_un.d_val & ~SUPPORTED_DT_FLAGS_1) != 0) {
|
|
DL_WARN("%s: unsupported flags DT_FLAGS_1=%p", get_realpath(), reinterpret_cast<void*>(d->d_un.d_val));
|
|
}
|
|
break;
|
|
#if defined(__mips__)
|
|
case DT_MIPS_RLD_MAP:
|
|
// Set the DT_MIPS_RLD_MAP entry to the address of _r_debug for GDB.
|
|
{
|
|
r_debug** dp = reinterpret_cast<r_debug**>(load_bias + d->d_un.d_ptr);
|
|
*dp = &_r_debug;
|
|
}
|
|
break;
|
|
case DT_MIPS_RLD_MAP2:
|
|
// Set the DT_MIPS_RLD_MAP2 entry to the address of _r_debug for GDB.
|
|
{
|
|
r_debug** dp = reinterpret_cast<r_debug**>(
|
|
reinterpret_cast<ElfW(Addr)>(d) + d->d_un.d_val);
|
|
*dp = &_r_debug;
|
|
}
|
|
break;
|
|
|
|
case DT_MIPS_RLD_VERSION:
|
|
case DT_MIPS_FLAGS:
|
|
case DT_MIPS_BASE_ADDRESS:
|
|
case DT_MIPS_UNREFEXTNO:
|
|
break;
|
|
|
|
case DT_MIPS_SYMTABNO:
|
|
mips_symtabno_ = d->d_un.d_val;
|
|
break;
|
|
|
|
case DT_MIPS_LOCAL_GOTNO:
|
|
mips_local_gotno_ = d->d_un.d_val;
|
|
break;
|
|
|
|
case DT_MIPS_GOTSYM:
|
|
mips_gotsym_ = d->d_un.d_val;
|
|
break;
|
|
#endif
|
|
// Ignored: "Its use has been superseded by the DF_BIND_NOW flag"
|
|
case DT_BIND_NOW:
|
|
break;
|
|
|
|
case DT_VERSYM:
|
|
versym_ = reinterpret_cast<ElfW(Versym)*>(load_bias + d->d_un.d_ptr);
|
|
break;
|
|
|
|
case DT_VERDEF:
|
|
verdef_ptr_ = load_bias + d->d_un.d_ptr;
|
|
break;
|
|
case DT_VERDEFNUM:
|
|
verdef_cnt_ = d->d_un.d_val;
|
|
break;
|
|
|
|
case DT_VERNEED:
|
|
verneed_ptr_ = load_bias + d->d_un.d_ptr;
|
|
break;
|
|
|
|
case DT_VERNEEDNUM:
|
|
verneed_cnt_ = d->d_un.d_val;
|
|
break;
|
|
|
|
case DT_RUNPATH:
|
|
// this is parsed after we have strtab initialized (see below).
|
|
break;
|
|
|
|
default:
|
|
if (!relocating_linker) {
|
|
DL_WARN("%s: unused DT entry: type %p arg %p", get_realpath(),
|
|
reinterpret_cast<void*>(d->d_tag), reinterpret_cast<void*>(d->d_un.d_val));
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
#if defined(__mips__) && !defined(__LP64__)
|
|
if (!mips_check_and_adjust_fp_modes()) {
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
DEBUG("si->base = %p, si->strtab = %p, si->symtab = %p",
|
|
reinterpret_cast<void*>(base), strtab_, symtab_);
|
|
|
|
// Sanity checks.
|
|
if (relocating_linker && needed_count != 0) {
|
|
DL_ERR("linker cannot have DT_NEEDED dependencies on other libraries");
|
|
return false;
|
|
}
|
|
if (nbucket_ == 0 && gnu_nbucket_ == 0) {
|
|
DL_ERR("empty/missing DT_HASH/DT_GNU_HASH in \"%s\" "
|
|
"(new hash type from the future?)", get_realpath());
|
|
return false;
|
|
}
|
|
if (strtab_ == 0) {
|
|
DL_ERR("empty/missing DT_STRTAB in \"%s\"", get_realpath());
|
|
return false;
|
|
}
|
|
if (symtab_ == 0) {
|
|
DL_ERR("empty/missing DT_SYMTAB in \"%s\"", get_realpath());
|
|
return false;
|
|
}
|
|
|
|
// second pass - parse entries relying on strtab
|
|
for (ElfW(Dyn)* d = dynamic; d->d_tag != DT_NULL; ++d) {
|
|
switch (d->d_tag) {
|
|
case DT_SONAME:
|
|
set_soname(get_string(d->d_un.d_val));
|
|
break;
|
|
case DT_RUNPATH:
|
|
set_dt_runpath(get_string(d->d_un.d_val));
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Before M release linker was using basename in place of soname.
|
|
// In the case when dt_soname is absent some apps stop working
|
|
// because they can't find dt_needed library by soname.
|
|
// This workaround should keep them working. (applies only
|
|
// for apps targeting sdk version <=22). Make an exception for
|
|
// the main executable and linker; they do not need to have dt_soname
|
|
if (soname_ == nullptr && this != somain && (flags_ & FLAG_LINKER) == 0 &&
|
|
get_application_target_sdk_version() <= 22) {
|
|
soname_ = basename(realpath_.c_str());
|
|
DL_WARN("%s: is missing DT_SONAME will use basename as a replacement: \"%s\"",
|
|
get_realpath(), soname_);
|
|
// Don't call add_dlwarning because a missing DT_SONAME isn't important enough to show in the UI
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool soinfo::link_image(const soinfo_list_t& global_group, const soinfo_list_t& local_group,
|
|
const android_dlextinfo* extinfo) {
|
|
|
|
local_group_root_ = local_group.front();
|
|
if (local_group_root_ == nullptr) {
|
|
local_group_root_ = this;
|
|
}
|
|
|
|
if ((flags_ & FLAG_LINKER) == 0 && local_group_root_ == this) {
|
|
target_sdk_version_ = get_application_target_sdk_version();
|
|
}
|
|
|
|
VersionTracker version_tracker;
|
|
|
|
if (!version_tracker.init(this)) {
|
|
return false;
|
|
}
|
|
|
|
#if !defined(__LP64__)
|
|
if (has_text_relocations) {
|
|
// Fail if app is targeting sdk version > 22
|
|
if (get_application_target_sdk_version() > 22) {
|
|
PRINT("%s: has text relocations", get_realpath());
|
|
DL_ERR("%s: has text relocations", get_realpath());
|
|
return false;
|
|
}
|
|
// Make segments writable to allow text relocations to work properly. We will later call
|
|
// phdr_table_protect_segments() after all of them are applied.
|
|
DL_WARN("%s has text relocations. This is wasting memory and prevents "
|
|
"security hardening. Please fix.", get_realpath());
|
|
add_dlwarning(get_realpath(), "text relocations");
|
|
if (phdr_table_unprotect_segments(phdr, phnum, load_bias) < 0) {
|
|
DL_ERR("can't unprotect loadable segments for \"%s\": %s",
|
|
get_realpath(), strerror(errno));
|
|
return false;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
if (android_relocs_ != nullptr) {
|
|
// check signature
|
|
if (android_relocs_size_ > 3 &&
|
|
android_relocs_[0] == 'A' &&
|
|
android_relocs_[1] == 'P' &&
|
|
android_relocs_[2] == 'S' &&
|
|
android_relocs_[3] == '2') {
|
|
DEBUG("[ android relocating %s ]", get_realpath());
|
|
|
|
bool relocated = false;
|
|
const uint8_t* packed_relocs = android_relocs_ + 4;
|
|
const size_t packed_relocs_size = android_relocs_size_ - 4;
|
|
|
|
relocated = relocate(
|
|
version_tracker,
|
|
packed_reloc_iterator<sleb128_decoder>(
|
|
sleb128_decoder(packed_relocs, packed_relocs_size)),
|
|
global_group, local_group);
|
|
|
|
if (!relocated) {
|
|
return false;
|
|
}
|
|
} else {
|
|
DL_ERR("bad android relocation header.");
|
|
return false;
|
|
}
|
|
}
|
|
|
|
#if defined(USE_RELA)
|
|
if (rela_ != nullptr) {
|
|
DEBUG("[ relocating %s ]", get_realpath());
|
|
if (!relocate(version_tracker,
|
|
plain_reloc_iterator(rela_, rela_count_), global_group, local_group)) {
|
|
return false;
|
|
}
|
|
}
|
|
if (plt_rela_ != nullptr) {
|
|
DEBUG("[ relocating %s plt ]", get_realpath());
|
|
if (!relocate(version_tracker,
|
|
plain_reloc_iterator(plt_rela_, plt_rela_count_), global_group, local_group)) {
|
|
return false;
|
|
}
|
|
}
|
|
#else
|
|
if (rel_ != nullptr) {
|
|
DEBUG("[ relocating %s ]", get_realpath());
|
|
if (!relocate(version_tracker,
|
|
plain_reloc_iterator(rel_, rel_count_), global_group, local_group)) {
|
|
return false;
|
|
}
|
|
}
|
|
if (plt_rel_ != nullptr) {
|
|
DEBUG("[ relocating %s plt ]", get_realpath());
|
|
if (!relocate(version_tracker,
|
|
plain_reloc_iterator(plt_rel_, plt_rel_count_), global_group, local_group)) {
|
|
return false;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#if defined(__mips__)
|
|
if (!mips_relocate_got(version_tracker, global_group, local_group)) {
|
|
return false;
|
|
}
|
|
#endif
|
|
|
|
DEBUG("[ finished linking %s ]", get_realpath());
|
|
|
|
#if !defined(__LP64__)
|
|
if (has_text_relocations) {
|
|
// All relocations are done, we can protect our segments back to read-only.
|
|
if (phdr_table_protect_segments(phdr, phnum, load_bias) < 0) {
|
|
DL_ERR("can't protect segments for \"%s\": %s",
|
|
get_realpath(), strerror(errno));
|
|
return false;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/* We can also turn on GNU RELRO protection */
|
|
if (phdr_table_protect_gnu_relro(phdr, phnum, load_bias) < 0) {
|
|
DL_ERR("can't enable GNU RELRO protection for \"%s\": %s",
|
|
get_realpath(), strerror(errno));
|
|
return false;
|
|
}
|
|
|
|
/* Handle serializing/sharing the RELRO segment */
|
|
if (extinfo && (extinfo->flags & ANDROID_DLEXT_WRITE_RELRO)) {
|
|
if (phdr_table_serialize_gnu_relro(phdr, phnum, load_bias,
|
|
extinfo->relro_fd) < 0) {
|
|
DL_ERR("failed serializing GNU RELRO section for \"%s\": %s",
|
|
get_realpath(), strerror(errno));
|
|
return false;
|
|
}
|
|
} else if (extinfo && (extinfo->flags & ANDROID_DLEXT_USE_RELRO)) {
|
|
if (phdr_table_map_gnu_relro(phdr, phnum, load_bias,
|
|
extinfo->relro_fd) < 0) {
|
|
DL_ERR("failed mapping GNU RELRO section for \"%s\": %s",
|
|
get_realpath(), strerror(errno));
|
|
return false;
|
|
}
|
|
}
|
|
|
|
notify_gdb_of_load(this);
|
|
return true;
|
|
}
|
|
|
|
/*
|
|
* This function add vdso to internal dso list.
|
|
* It helps to stack unwinding through signal handlers.
|
|
* Also, it makes bionic more like glibc.
|
|
*/
|
|
static void add_vdso(KernelArgumentBlock& args __unused) {
|
|
#if defined(AT_SYSINFO_EHDR)
|
|
ElfW(Ehdr)* ehdr_vdso = reinterpret_cast<ElfW(Ehdr)*>(args.getauxval(AT_SYSINFO_EHDR));
|
|
if (ehdr_vdso == nullptr) {
|
|
return;
|
|
}
|
|
|
|
soinfo* si = soinfo_alloc(&g_default_namespace, "[vdso]", nullptr, 0, 0);
|
|
|
|
si->phdr = reinterpret_cast<ElfW(Phdr)*>(reinterpret_cast<char*>(ehdr_vdso) + ehdr_vdso->e_phoff);
|
|
si->phnum = ehdr_vdso->e_phnum;
|
|
si->base = reinterpret_cast<ElfW(Addr)>(ehdr_vdso);
|
|
si->size = phdr_table_get_load_size(si->phdr, si->phnum);
|
|
si->load_bias = get_elf_exec_load_bias(ehdr_vdso);
|
|
|
|
si->prelink_image();
|
|
si->link_image(g_empty_list, soinfo::soinfo_list_t::make_list(si), nullptr);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* This is linker soinfo for GDB. See details below.
|
|
*/
|
|
#if defined(__LP64__)
|
|
#define LINKER_PATH "/system/bin/linker64"
|
|
#else
|
|
#define LINKER_PATH "/system/bin/linker"
|
|
#endif
|
|
|
|
// This is done to avoid calling c-tor prematurely
|
|
// because soinfo c-tor needs memory allocator
|
|
// which might be initialized after global variables.
|
|
static uint8_t linker_soinfo_for_gdb_buf[sizeof(soinfo)] __attribute__((aligned(8)));
|
|
static soinfo* linker_soinfo_for_gdb = nullptr;
|
|
|
|
/* gdb expects the linker to be in the debug shared object list.
|
|
* Without this, gdb has trouble locating the linker's ".text"
|
|
* and ".plt" sections. Gdb could also potentially use this to
|
|
* relocate the offset of our exported 'rtld_db_dlactivity' symbol.
|
|
* Don't use soinfo_alloc(), because the linker shouldn't
|
|
* be on the soinfo list.
|
|
*/
|
|
static void init_linker_info_for_gdb(ElfW(Addr) linker_base) {
|
|
linker_soinfo_for_gdb = new (linker_soinfo_for_gdb_buf) soinfo(nullptr, LINKER_PATH,
|
|
nullptr, 0, 0);
|
|
|
|
linker_soinfo_for_gdb->load_bias = linker_base;
|
|
|
|
/*
|
|
* Set the dynamic field in the link map otherwise gdb will complain with
|
|
* the following:
|
|
* warning: .dynamic section for "/system/bin/linker" is not at the
|
|
* expected address (wrong library or version mismatch?)
|
|
*/
|
|
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_base);
|
|
ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_base + elf_hdr->e_phoff);
|
|
phdr_table_get_dynamic_section(phdr, elf_hdr->e_phnum, linker_base,
|
|
&linker_soinfo_for_gdb->dynamic, nullptr);
|
|
insert_soinfo_into_debug_map(linker_soinfo_for_gdb);
|
|
}
|
|
|
|
static void init_default_namespace() {
|
|
g_default_namespace.set_name("(default)");
|
|
g_default_namespace.set_isolated(false);
|
|
|
|
const char *interp = phdr_table_get_interpreter_name(somain->phdr, somain->phnum,
|
|
somain->load_bias);
|
|
const char* bname = basename(interp);
|
|
if (bname && (strcmp(bname, "linker_asan") == 0 || strcmp(bname, "linker_asan64") == 0)) {
|
|
g_default_ld_paths = kAsanDefaultLdPaths;
|
|
} else {
|
|
g_default_ld_paths = kDefaultLdPaths;
|
|
}
|
|
|
|
std::vector<std::string> ld_default_paths;
|
|
for (size_t i = 0; g_default_ld_paths[i] != nullptr; ++i) {
|
|
ld_default_paths.push_back(g_default_ld_paths[i]);
|
|
}
|
|
|
|
g_default_namespace.set_default_library_paths(std::move(ld_default_paths));
|
|
};
|
|
|
|
extern "C" int __system_properties_init(void);
|
|
|
|
/*
|
|
* This code is called after the linker has linked itself and
|
|
* fixed it's own GOT. It is safe to make references to externs
|
|
* and other non-local data at this point.
|
|
*/
|
|
static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW(Addr) linker_base) {
|
|
#if TIMING
|
|
struct timeval t0, t1;
|
|
gettimeofday(&t0, 0);
|
|
#endif
|
|
|
|
// Sanitize the environment.
|
|
__libc_init_AT_SECURE(args);
|
|
|
|
// Initialize system properties
|
|
__system_properties_init(); // may use 'environ'
|
|
|
|
debuggerd_init();
|
|
|
|
// Get a few environment variables.
|
|
const char* LD_DEBUG = getenv("LD_DEBUG");
|
|
if (LD_DEBUG != nullptr) {
|
|
g_ld_debug_verbosity = atoi(LD_DEBUG);
|
|
}
|
|
|
|
#if defined(__LP64__)
|
|
INFO("[ Android dynamic linker (64-bit) ]");
|
|
#else
|
|
INFO("[ Android dynamic linker (32-bit) ]");
|
|
#endif
|
|
|
|
// These should have been sanitized by __libc_init_AT_SECURE, but the test
|
|
// doesn't cost us anything.
|
|
const char* ldpath_env = nullptr;
|
|
const char* ldpreload_env = nullptr;
|
|
if (!getauxval(AT_SECURE)) {
|
|
ldpath_env = getenv("LD_LIBRARY_PATH");
|
|
if (ldpath_env != nullptr) {
|
|
INFO("[ LD_LIBRARY_PATH set to '%s' ]", ldpath_env);
|
|
}
|
|
ldpreload_env = getenv("LD_PRELOAD");
|
|
if (ldpreload_env != nullptr) {
|
|
INFO("[ LD_PRELOAD set to '%s' ]", ldpreload_env);
|
|
}
|
|
}
|
|
|
|
soinfo* si = soinfo_alloc(&g_default_namespace, args.argv[0], nullptr, 0, RTLD_GLOBAL);
|
|
if (si == nullptr) {
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
/* bootstrap the link map, the main exe always needs to be first */
|
|
si->set_main_executable();
|
|
link_map* map = &(si->link_map_head);
|
|
|
|
map->l_addr = 0;
|
|
map->l_name = args.argv[0];
|
|
map->l_prev = nullptr;
|
|
map->l_next = nullptr;
|
|
|
|
_r_debug.r_map = map;
|
|
r_debug_tail = map;
|
|
|
|
init_linker_info_for_gdb(linker_base);
|
|
|
|
// Extract information passed from the kernel.
|
|
si->phdr = reinterpret_cast<ElfW(Phdr)*>(args.getauxval(AT_PHDR));
|
|
si->phnum = args.getauxval(AT_PHNUM);
|
|
si->entry = args.getauxval(AT_ENTRY);
|
|
|
|
/* Compute the value of si->base. We can't rely on the fact that
|
|
* the first entry is the PHDR because this will not be true
|
|
* for certain executables (e.g. some in the NDK unit test suite)
|
|
*/
|
|
si->base = 0;
|
|
si->size = phdr_table_get_load_size(si->phdr, si->phnum);
|
|
si->load_bias = 0;
|
|
for (size_t i = 0; i < si->phnum; ++i) {
|
|
if (si->phdr[i].p_type == PT_PHDR) {
|
|
si->load_bias = reinterpret_cast<ElfW(Addr)>(si->phdr) - si->phdr[i].p_vaddr;
|
|
si->base = reinterpret_cast<ElfW(Addr)>(si->phdr) - si->phdr[i].p_offset;
|
|
break;
|
|
}
|
|
}
|
|
si->dynamic = nullptr;
|
|
|
|
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(si->base);
|
|
if (elf_hdr->e_type != ET_DYN) {
|
|
__libc_format_fd(2, "error: only position independent executables (PIE) are supported.\n");
|
|
exit(EXIT_FAILURE);
|
|
}
|
|
|
|
// Use LD_LIBRARY_PATH and LD_PRELOAD (but only if we aren't setuid/setgid).
|
|
parse_LD_LIBRARY_PATH(ldpath_env);
|
|
parse_LD_PRELOAD(ldpreload_env);
|
|
|
|
somain = si;
|
|
|
|
init_default_namespace();
|
|
|
|
if (!si->prelink_image()) {
|
|
__libc_fatal("CANNOT LINK EXECUTABLE: %s", linker_get_error_buffer());
|
|
}
|
|
|
|
// add somain to global group
|
|
si->set_dt_flags_1(si->get_dt_flags_1() | DF_1_GLOBAL);
|
|
|
|
// Load ld_preloads and dependencies.
|
|
StringLinkedList needed_library_name_list;
|
|
size_t needed_libraries_count = 0;
|
|
size_t ld_preloads_count = 0;
|
|
|
|
for (const auto& ld_preload_name : g_ld_preload_names) {
|
|
needed_library_name_list.push_back(ld_preload_name.c_str());
|
|
++needed_libraries_count;
|
|
++ld_preloads_count;
|
|
}
|
|
|
|
for_each_dt_needed(si, [&](const char* name) {
|
|
needed_library_name_list.push_back(name);
|
|
++needed_libraries_count;
|
|
});
|
|
|
|
const char* needed_library_names[needed_libraries_count];
|
|
|
|
memset(needed_library_names, 0, sizeof(needed_library_names));
|
|
needed_library_name_list.copy_to_array(needed_library_names, needed_libraries_count);
|
|
|
|
if (needed_libraries_count > 0 &&
|
|
!find_libraries(&g_default_namespace, si, needed_library_names, needed_libraries_count,
|
|
nullptr, &g_ld_preloads, ld_preloads_count, RTLD_GLOBAL, nullptr,
|
|
/* add_as_children */ true)) {
|
|
__libc_fatal("CANNOT LINK EXECUTABLE: %s", linker_get_error_buffer());
|
|
} else if (needed_libraries_count == 0) {
|
|
if (!si->link_image(g_empty_list, soinfo::soinfo_list_t::make_list(si), nullptr)) {
|
|
__libc_fatal("CANNOT LINK EXECUTABLE: %s", linker_get_error_buffer());
|
|
}
|
|
si->increment_ref_count();
|
|
}
|
|
|
|
add_vdso(args);
|
|
|
|
{
|
|
ProtectedDataGuard guard;
|
|
|
|
si->call_pre_init_constructors();
|
|
|
|
/* After the prelink_image, the si->load_bias is initialized.
|
|
* For so lib, the map->l_addr will be updated in notify_gdb_of_load.
|
|
* We need to update this value for so exe here. So Unwind_Backtrace
|
|
* for some arch like x86 could work correctly within so exe.
|
|
*/
|
|
map->l_addr = si->load_bias;
|
|
si->call_constructors();
|
|
}
|
|
|
|
#if TIMING
|
|
gettimeofday(&t1, nullptr);
|
|
PRINT("LINKER TIME: %s: %d microseconds", args.argv[0], (int) (
|
|
(((long long)t1.tv_sec * 1000000LL) + (long long)t1.tv_usec) -
|
|
(((long long)t0.tv_sec * 1000000LL) + (long long)t0.tv_usec)));
|
|
#endif
|
|
#if STATS
|
|
PRINT("RELO STATS: %s: %d abs, %d rel, %d copy, %d symbol", args.argv[0],
|
|
linker_stats.count[kRelocAbsolute],
|
|
linker_stats.count[kRelocRelative],
|
|
linker_stats.count[kRelocCopy],
|
|
linker_stats.count[kRelocSymbol]);
|
|
#endif
|
|
#if COUNT_PAGES
|
|
{
|
|
unsigned n;
|
|
unsigned i;
|
|
unsigned count = 0;
|
|
for (n = 0; n < 4096; n++) {
|
|
if (bitmask[n]) {
|
|
unsigned x = bitmask[n];
|
|
#if defined(__LP64__)
|
|
for (i = 0; i < 32; i++) {
|
|
#else
|
|
for (i = 0; i < 8; i++) {
|
|
#endif
|
|
if (x & 1) {
|
|
count++;
|
|
}
|
|
x >>= 1;
|
|
}
|
|
}
|
|
}
|
|
PRINT("PAGES MODIFIED: %s: %d (%dKB)", args.argv[0], count, count * 4);
|
|
}
|
|
#endif
|
|
|
|
#if TIMING || STATS || COUNT_PAGES
|
|
fflush(stdout);
|
|
#endif
|
|
|
|
TRACE("[ Ready to execute '%s' @ %p ]", si->get_realpath(), reinterpret_cast<void*>(si->entry));
|
|
return si->entry;
|
|
}
|
|
|
|
/* Compute the load-bias of an existing executable. This shall only
|
|
* be used to compute the load bias of an executable or shared library
|
|
* that was loaded by the kernel itself.
|
|
*
|
|
* Input:
|
|
* elf -> address of ELF header, assumed to be at the start of the file.
|
|
* Return:
|
|
* load bias, i.e. add the value of any p_vaddr in the file to get
|
|
* the corresponding address in memory.
|
|
*/
|
|
static ElfW(Addr) get_elf_exec_load_bias(const ElfW(Ehdr)* elf) {
|
|
ElfW(Addr) offset = elf->e_phoff;
|
|
const ElfW(Phdr)* phdr_table =
|
|
reinterpret_cast<const ElfW(Phdr)*>(reinterpret_cast<uintptr_t>(elf) + offset);
|
|
const ElfW(Phdr)* phdr_end = phdr_table + elf->e_phnum;
|
|
|
|
for (const ElfW(Phdr)* phdr = phdr_table; phdr < phdr_end; phdr++) {
|
|
if (phdr->p_type == PT_LOAD) {
|
|
return reinterpret_cast<ElfW(Addr)>(elf) + phdr->p_offset - phdr->p_vaddr;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
extern "C" int __set_tls(void*);
|
|
extern "C" void _start();
|
|
|
|
/*
|
|
* This is the entry point for the linker, called from begin.S. This
|
|
* method is responsible for fixing the linker's own relocations, and
|
|
* then calling __linker_init_post_relocation().
|
|
*
|
|
* Because this method is called before the linker has fixed it's own
|
|
* relocations, any attempt to reference an extern variable, extern
|
|
* function, or other GOT reference will generate a segfault.
|
|
*/
|
|
extern "C" ElfW(Addr) __linker_init(void* raw_args) {
|
|
KernelArgumentBlock args(raw_args);
|
|
|
|
void* tls[BIONIC_TLS_SLOTS];
|
|
__set_tls(tls);
|
|
|
|
ElfW(Addr) linker_addr = args.getauxval(AT_BASE);
|
|
ElfW(Addr) entry_point = args.getauxval(AT_ENTRY);
|
|
ElfW(Ehdr)* elf_hdr = reinterpret_cast<ElfW(Ehdr)*>(linker_addr);
|
|
ElfW(Phdr)* phdr = reinterpret_cast<ElfW(Phdr)*>(linker_addr + elf_hdr->e_phoff);
|
|
|
|
soinfo linker_so(nullptr, nullptr, nullptr, 0, 0);
|
|
|
|
// If the linker is not acting as PT_INTERP entry_point is equal to
|
|
// _start. Which means that the linker is running as an executable and
|
|
// already linked by PT_INTERP.
|
|
//
|
|
// This happens when user tries to run 'adb shell /system/bin/linker'
|
|
// see also https://code.google.com/p/android/issues/detail?id=63174
|
|
if (reinterpret_cast<ElfW(Addr)>(&_start) == entry_point) {
|
|
__libc_fatal("This is %s, the helper program for shared library executables.", args.argv[0]);
|
|
}
|
|
|
|
linker_so.base = linker_addr;
|
|
linker_so.size = phdr_table_get_load_size(phdr, elf_hdr->e_phnum);
|
|
linker_so.load_bias = get_elf_exec_load_bias(elf_hdr);
|
|
linker_so.dynamic = nullptr;
|
|
linker_so.phdr = phdr;
|
|
linker_so.phnum = elf_hdr->e_phnum;
|
|
linker_so.set_linker_flag();
|
|
|
|
// This might not be obvious... The reasons why we pass g_empty_list
|
|
// in place of local_group here are (1) we do not really need it, because
|
|
// linker is built with DT_SYMBOLIC and therefore relocates its symbols against
|
|
// itself without having to look into local_group and (2) allocators
|
|
// are not yet initialized, and therefore we cannot use linked_list.push_*
|
|
// functions at this point.
|
|
if (!(linker_so.prelink_image() && linker_so.link_image(g_empty_list, g_empty_list, nullptr))) {
|
|
__libc_fatal("CANNOT LINK EXECUTABLE: %s", linker_get_error_buffer());
|
|
}
|
|
|
|
__libc_init_main_thread(args);
|
|
|
|
// Initialize the linker's static libc's globals
|
|
__libc_init_globals(args);
|
|
|
|
// Initialize the linker's own global variables
|
|
linker_so.call_constructors();
|
|
|
|
// Initialize static variables. Note that in order to
|
|
// get correct libdl_info we need to call constructors
|
|
// before get_libdl_info().
|
|
solist = get_libdl_info();
|
|
sonext = get_libdl_info();
|
|
g_default_namespace.soinfo_list().push_back(get_libdl_info());
|
|
|
|
// We have successfully fixed our own relocations. It's safe to run
|
|
// the main part of the linker now.
|
|
args.abort_message_ptr = &g_abort_message;
|
|
ElfW(Addr) start_address = __linker_init_post_relocation(args, linker_addr);
|
|
|
|
INFO("[ Jumping to _start (%p)... ]", reinterpret_cast<void*>(start_address));
|
|
|
|
// Return the address that the calling assembly stub should jump to.
|
|
return start_address;
|
|
}
|