diff options
Diffstat (limited to 'linker/linker.cpp')
| -rw-r--r-- | linker/linker.cpp | 531 |
1 files changed, 410 insertions, 121 deletions
diff --git a/linker/linker.cpp b/linker/linker.cpp index 31ed1ec19..32e3063fd 100644 --- a/linker/linker.cpp +++ b/linker/linker.cpp @@ -70,11 +70,55 @@ extern void __libc_init_AT_SECURE(KernelArgumentBlock&); #undef ELF_ST_TYPE #define ELF_ST_TYPE(x) (static_cast<uint32_t>(x) & 0xf) +struct android_namespace_t { + public: + android_namespace_t() : name_(nullptr), is_isolated_(false) {} + + const char* get_name() const { return name_; } + void set_name(const char* name) { name_ = name; } + + bool is_isolated() const { return is_isolated_; } + void set_isolated(bool isolated) { is_isolated_ = isolated; } + + const std::vector<std::string>& get_ld_library_paths() const { + return ld_library_paths_; + } + void set_ld_library_paths(std::vector<std::string>&& library_paths) { + ld_library_paths_ = library_paths; + } + + const std::vector<std::string>& get_default_library_paths() const { + return default_library_paths_; + } + void set_default_library_paths(std::vector<std::string>&& library_paths) { + default_library_paths_ = library_paths; + } + + soinfo::soinfo_list_t& soinfo_list() { return soinfo_list_; } + + // For isolated namespaces - checks if the file is on the search path; + // always returns true for not isolated namespace. + bool is_accessible(const std::string& path); + + private: + const char* name_; + bool is_isolated_; + std::vector<std::string> ld_library_paths_; + std::vector<std::string> default_library_paths_; + soinfo::soinfo_list_t soinfo_list_; + + DISALLOW_COPY_AND_ASSIGN(android_namespace_t); +}; + +android_namespace_t g_default_namespace; + static ElfW(Addr) get_elf_exec_load_bias(const ElfW(Ehdr)* elf); static LinkerTypeAllocator<soinfo> g_soinfo_allocator; static LinkerTypeAllocator<LinkedListEntry<soinfo>> g_soinfo_links_allocator; +static LinkerTypeAllocator<android_namespace_t> g_namespace_allocator; + static soinfo* solist; static soinfo* sonext; static soinfo* somain; // main process, always the one after libdl_info @@ -107,14 +151,15 @@ static const char* const kAsanDefaultLdPaths[] = { static const ElfW(Versym) kVersymNotNeeded = 0; static const ElfW(Versym) kVersymGlobal = 1; -static const char* const kZipFileSeparator = "!/"; static const char* const* g_default_ld_paths; -static std::vector<std::string> g_ld_library_paths; static std::vector<std::string> g_ld_preload_names; static std::vector<soinfo*> g_ld_preloads; +static bool g_public_namespace_initialized; +static soinfo::soinfo_list_t g_public_namespace; + __LIBC_HIDDEN__ int g_ld_debug_verbosity; __LIBC_HIDDEN__ abort_msg_t* g_abort_message = nullptr; // For debuggerd. @@ -247,6 +292,26 @@ void notify_gdb_of_libraries() { rtld_db_dlactivity(); } +bool android_namespace_t::is_accessible(const std::string& file) { + if (!is_isolated_) { + return true; + } + + for (const auto& dir : ld_library_paths_) { + if (file_is_in_dir(file, dir)) { + return true; + } + } + + for (const auto& dir : default_library_paths_) { + if (file_is_in_dir(file, dir)) { + return true; + } + } + + return false; +} + LinkedListEntry<soinfo>* SoinfoListAllocator::alloc() { return g_soinfo_links_allocator.alloc(); } @@ -255,18 +320,22 @@ void SoinfoListAllocator::free(LinkedListEntry<soinfo>* entry) { g_soinfo_links_allocator.free(entry); } -static soinfo* soinfo_alloc(const char* name, struct stat* file_stat, - off64_t file_offset, uint32_t rtld_flags) { +static soinfo* soinfo_alloc(android_namespace_t* ns, const char* name, + struct stat* file_stat, off64_t file_offset, + uint32_t rtld_flags) { if (strlen(name) >= PATH_MAX) { DL_ERR("library name \"%s\" too long", name); return nullptr; } - soinfo* si = new (g_soinfo_allocator.alloc()) soinfo(name, file_stat, file_offset, rtld_flags); + soinfo* si = new (g_soinfo_allocator.alloc()) soinfo(ns, name, file_stat, + file_offset, rtld_flags); sonext->next = si; sonext = si; + ns->soinfo_list().push_back(si); + TRACE("name %s: allocated soinfo @ %p", name, si); return si; } @@ -307,33 +376,130 @@ static void soinfo_free(soinfo* si) { sonext = prev; } + // remove from the namespace + si->get_namespace()->soinfo_list().remove_if([&](soinfo* candidate) { + return si == candidate; + }); + si->~soinfo(); g_soinfo_allocator.free(si); } -static void parse_path(const char* path, const char* delimiters, +// For every path element this function checks of it exists, and is a directory, +// and normalizes it: +// 1. For regular path it converts it to realpath() +// 2. For path in a zip file it uses realpath on the zipfile +// normalizes entry name by calling normalize_path function. +static void resolve_paths(std::vector<std::string>& paths, + std::vector<std::string>* resolved_paths) { + resolved_paths->clear(); + for (const auto& path : paths) { + char resolved_path[PATH_MAX]; + const char* original_path = path.c_str(); + if (realpath(original_path, resolved_path) != nullptr) { + struct stat s; + if (stat(resolved_path, &s) == 0) { + if (S_ISDIR(s.st_mode)) { + resolved_paths->push_back(resolved_path); + } else { + DL_WARN("Warning: \"%s\" is not a directory (excluding from path)", resolved_path); + continue; + } + } else { + DL_WARN("Warning: cannot stat file \"%s\": %s", resolved_path, strerror(errno)); + continue; + } + } else { + std::string zip_path; + std::string entry_path; + + std::string normalized_path; + + if (!normalize_path(original_path, &normalized_path)) { + DL_WARN("Warning: unable to normalize \"%s\"", original_path); + continue; + } + + if (parse_zip_path(normalized_path.c_str(), &zip_path, &entry_path)) { + if (realpath(zip_path.c_str(), resolved_path) == nullptr) { + DL_WARN("Warning: unable to resolve \"%s\": %s", zip_path.c_str(), strerror(errno)); + continue; + } + + ZipArchiveHandle handle = nullptr; + if (OpenArchive(resolved_path, &handle) != 0) { + DL_WARN("Warning: unable to open zip archive: %s", resolved_path); + continue; + } + + // 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) { - paths->clear(); if (path != nullptr) { *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) { - parse_path(path, ":", &g_ld_library_paths); + 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(2)) { + if (!has_min_version(3)) { return; } - parse_path(path, ":", &dt_runpath_); + std::vector<std::string> runpaths; + + split_path(path, ":", &runpaths); std::string origin = dirname(get_realpath()); // FIXME: add $LIB and $PLATFORM. std::pair<std::string, std::string> substs[] = {{"ORIGIN", origin}}; - for (auto&& s : dt_runpath_) { + for (auto&& s : runpaths) { size_t pos = 0; while (pos < s.size()) { pos = s.find("$", pos); @@ -356,11 +522,16 @@ void soinfo::set_dt_runpath(const char* path) { ++pos; } } + + resolve_paths(runpaths, &dt_runpath_); } static void parse_LD_PRELOAD(const char* path) { - // We have historically supported ':' as well as ' ' in LD_PRELOAD. - parse_path(path, " :", &g_ld_preload_names); + 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) { @@ -688,8 +859,9 @@ bool soinfo::elf_lookup(SymbolName& symbol_name, return true; } -soinfo::soinfo(const char* realpath, const struct stat* file_stat, - off64_t file_offset, int rtld_flags) { +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) { @@ -706,6 +878,7 @@ soinfo::soinfo(const char* realpath, const struct stat* file_stat, } this->rtld_flags_ = rtld_flags; + this->namespace_ = ns; } @@ -857,6 +1030,7 @@ class ProtectedDataGuard { 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_; @@ -1096,7 +1270,7 @@ const ElfW(Sym)* dlsym_handle_lookup(soinfo* si, soinfo** found, const char* nam // 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(name, found, nullptr, RTLD_DEFAULT); + return dlsym_linear_lookup(&g_default_namespace, name, found, nullptr, RTLD_DEFAULT); } SymbolName symbol_name(name); @@ -1108,24 +1282,29 @@ const ElfW(Sym)* dlsym_handle_lookup(soinfo* si, soinfo** found, const char* nam beginning of the global solist. Otherwise the search starts at the specified soinfo (for RTLD_NEXT). */ -const ElfW(Sym)* dlsym_linear_lookup(const char* name, +const ElfW(Sym)* dlsym_linear_lookup(android_namespace_t* ns, + const char* name, soinfo** found, soinfo* caller, void* handle) { SymbolName symbol_name(name); - soinfo* start = solist; + 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 { - start = caller->next; + soinfo::soinfo_list_t::iterator it = soinfo_list.find(caller); + CHECK (it != soinfo_list.end()); + start = ++it; } } const ElfW(Sym)* s = nullptr; - for (soinfo* si = start; si != nullptr; si = si->next) { + 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 @@ -1337,35 +1516,13 @@ static bool format_path(char* buf, size_t buf_size, const char* path, const char return true; } -static int open_library_on_default_path(const char* name, off64_t* file_offset, std::string* realpath) { - for (size_t i = 0; g_default_ld_paths[i] != nullptr; ++i) { - char buf[512]; - if (!format_path(buf, sizeof(buf), g_default_ld_paths[i], name)) { - continue; - } - - int 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; - } - return fd; - } - } - - return -1; -} - 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_str : paths) { + for (const auto& path : paths) { char buf[512]; - const char* const path = path_str.c_str(); - if (!format_path(buf, sizeof(buf), path, name)) { + if (!format_path(buf, sizeof(buf), path.c_str(), name)) { continue; } @@ -1393,39 +1550,49 @@ static int open_library_on_paths(ZipArchiveCache* zip_archive_cache, return -1; } -static int open_library(ZipArchiveCache* zip_archive_cache, +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) { - int fd = open_library_in_zipfile(zip_archive_cache, name, file_offset, realpath); + 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) { - return fd; + *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; + } } } - int 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; - } + if (fd != -1 && !ns->is_accessible(*realpath)) { + fd = -1; } return fd; } - // Otherwise we try LD_LIBRARY_PATH first, and fall back to the built-in well known paths. - int fd = open_library_on_paths(zip_archive_cache, name, file_offset, g_ld_library_paths, realpath); + // 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_default_path(name, file_offset, realpath); + fd = open_library_on_paths(zip_archive_cache, name, file_offset, ns->get_default_library_paths(), realpath); } return fd; @@ -1464,7 +1631,8 @@ static void for_each_dt_needed(const ElfReader& elf_reader, F action) { } } -static bool load_library(LoadTask* task, +static bool load_library(android_namespace_t* ns, + LoadTask* task, LoadTaskList* load_tasks, int rtld_flags, const std::string& realpath) { @@ -1495,18 +1663,30 @@ static bool load_library(LoadTask* task, // 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) { - for (soinfo* si = solist; si != nullptr; si = si->next) { - if (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) { - 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; + 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) { @@ -1514,7 +1694,7 @@ static bool load_library(LoadTask* task, return false; } - soinfo* si = soinfo_alloc(realpath.c_str(), &file_stat, file_offset, rtld_flags); + soinfo* si = soinfo_alloc(ns, realpath.c_str(), &file_stat, file_offset, rtld_flags); if (si == nullptr) { return false; } @@ -1550,7 +1730,8 @@ static bool load_library(LoadTask* task, } -static bool load_library(LoadTask* task, +static bool load_library(android_namespace_t* ns, + LoadTask* task, ZipArchiveCache* zip_archive_cache, LoadTaskList* load_tasks, int rtld_flags) { @@ -1574,11 +1755,11 @@ static bool load_library(LoadTask* task, task->set_fd(extinfo->library_fd, false); task->set_file_offset(file_offset); - return load_library(task, load_tasks, rtld_flags, realpath); + return load_library(ns, task, load_tasks, rtld_flags, realpath); } // Open the file. - int fd = open_library(zip_archive_cache, name, needed_by, &file_offset, &realpath); + 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; @@ -1587,14 +1768,15 @@ static bool load_library(LoadTask* task, task->set_fd(fd, true); task->set_file_offset(file_offset); - return load_library(task, load_tasks, rtld_flags, realpath); + return load_library(ns, task, load_tasks, rtld_flags, realpath); } // Returns true if library was found and false in 2 cases -// 1. The library was found but loaded under different target_sdk_version -// (*candidate != nullptr) +// 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(const char* name, soinfo** candidate) { +static bool find_loaded_library_by_soname(android_namespace_t* ns, + const char* name, soinfo** candidate) { *candidate = nullptr; // Ignore filename with path. @@ -1604,7 +1786,7 @@ static bool find_loaded_library_by_soname(const char* name, soinfo** candidate) uint32_t target_sdk_version = get_application_target_sdk_version(); - for (soinfo* si = solist; si != nullptr; si = si->next) { + 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 @@ -1614,36 +1796,52 @@ static bool find_loaded_library_by_soname(const char* name, soinfo** candidate) // 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) { + !si->is_linked() || si->get_target_sdk_version() == target_sdk_version || + ns != &g_default_namespace) { *candidate = si; - return true; + return false; } else if (*candidate == nullptr) { - // for the different sdk version - remember the first library. + // for the different sdk version in the default namespace + // remember the first library. *candidate = si; } } - } - return false; + return true; + }); } -static bool find_library_internal(LoadTask* task, +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(task->get_name(), &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(task, zip_archive_cache, load_tasks, rtld_flags)) { + 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 @@ -1667,13 +1865,13 @@ static void soinfo_unload(soinfo* si); // // 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() { +static soinfo::soinfo_list_t make_global_group(android_namespace_t* ns) { soinfo::soinfo_list_t global_group; - for (soinfo* si = somain; si != nullptr; si = si->next) { + 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; } @@ -1690,7 +1888,8 @@ static void shuffle(std::vector<LoadTask*>* v) { // 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(soinfo* start_with, +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, @@ -1707,7 +1906,7 @@ static bool find_libraries(soinfo* start_with, } // Construct global_group. - soinfo::soinfo_list_t global_group = make_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 @@ -1749,7 +1948,7 @@ static bool find_libraries(soinfo* start_with, bool is_dt_needed = needed_by != nullptr && (needed_by != start_with || add_as_children); task->set_extinfo(is_dt_needed ? nullptr : extinfo); - if(!find_library_internal(task, &zip_archive_cache, &load_tasks, rtld_flags)) { + if(!find_library_internal(ns, task, &zip_archive_cache, &load_tasks, rtld_flags)) { return false; } @@ -1850,14 +2049,15 @@ static bool find_libraries(soinfo* start_with, return linked; } -static soinfo* find_library(const char* name, int rtld_flags, +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(needed_by, &name, 1, &si, nullptr, 0, rtld_flags, + } else if (!find_libraries(ns, needed_by, &name, 1, &si, nullptr, 0, rtld_flags, extinfo, /* add_as_children */ false)) { return nullptr; } @@ -1920,7 +2120,9 @@ static void soinfo_unload(soinfo* root) { TRACE("deprecated (old format of soinfo): %s needs to unload %s", si->get_realpath(), library_name); - soinfo* needed = find_library(library_name, RTLD_NOLOAD, nullptr, nullptr); + 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. @@ -1992,6 +2194,9 @@ soinfo* do_dlopen(const char* name, int flags, const android_dlextinfo* extinfo, DL_ERR("invalid flags to dlopen: %x", flags); return nullptr; } + + android_namespace_t* ns = caller->get_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); @@ -2011,13 +2216,22 @@ soinfo* do_dlopen(const char* name, int flags, const android_dlextinfo* extinfo, "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(name, flags, extinfo, caller); + soinfo* si = find_library(ns, name, flags, extinfo, caller); if (si != nullptr) { si->call_constructors(); } + return si; } @@ -2026,6 +2240,67 @@ void do_dlclose(soinfo* si) { soinfo_unload(si); } +bool init_public_namespace(const char* libs) { + CHECK(libs != nullptr); + if (g_public_namespace_initialized) { + DL_ERR("Public namespace has already been initialized."); + return false; + } + + std::vector<std::string> sonames = android::base::Split(libs, ":"); + + ProtectedDataGuard guard; + + auto failure_guard = make_scope_guard([&]() { + g_public_namespace.clear(); + }); + + soinfo* candidate; + for (const auto& soname : sonames) { + if (!find_loaded_library_by_soname(&g_default_namespace, soname.c_str(), &candidate)) { + 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); + } + + failure_guard.disable(); + g_public_namespace_initialized = true; + return true; +} + +android_namespace_t* create_namespace(const char* name, + const char* ld_library_path, + const char* default_library_path, + bool is_isolated) { + if (!g_public_namespace_initialized) { + DL_ERR("Cannot create namespace: public namespace is not initialized."); + return nullptr; + } + + ProtectedDataGuard guard; + std::vector<std::string> ld_library_paths; + std::vector<std::string> default_library_paths; + + parse_path(ld_library_path, ":", &ld_library_paths); + parse_path(default_library_path, ":", &default_library_paths); + + android_namespace_t* ns = new (g_namespace_allocator.alloc()) android_namespace_t(); + ns->set_name(name); + ns->set_isolated(is_isolated); + ns->set_ld_library_paths(std::move(ld_library_paths)); + ns->set_default_library_paths(std::move(default_library_paths)); + + // TODO(dimtiry): Should this be global group of caller's namespace? + auto global_group = make_global_group(&g_default_namespace); + 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); @@ -2694,6 +2969,10 @@ void soinfo::set_dt_flags_1(uint32_t 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)) { @@ -2760,13 +3039,21 @@ soinfo::soinfo_list_t& soinfo::get_parents() { static std::vector<std::string> g_empty_runpath; const std::vector<std::string>& soinfo::get_dt_runpath() const { - if (has_min_version(2)) { + 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); @@ -3464,7 +3751,8 @@ static soinfo* linker_soinfo_for_gdb = nullptr; * 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(LINKER_PATH, nullptr, 0, 0); + 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; @@ -3481,14 +3769,25 @@ static void init_linker_info_for_gdb(ElfW(Addr) linker_base) { insert_soinfo_into_debug_map(linker_soinfo_for_gdb); } -static void init_default_ld_library_path() { +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)) + if (bname && (strcmp(bname, "linker_asan") == 0 || strcmp(bname, "linker_asan64") == 0)) { g_default_ld_paths = kAsanDefaultLdPaths; - else + } 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); @@ -3529,7 +3828,7 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW( INFO("[ android linker & debugger ]"); - soinfo* si = soinfo_alloc(args.argv[0], nullptr, 0, RTLD_GLOBAL); + soinfo* si = soinfo_alloc(&g_default_namespace, args.argv[0], nullptr, 0, RTLD_GLOBAL); if (si == nullptr) { exit(EXIT_FAILURE); } @@ -3581,11 +3880,10 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW( somain = si; - init_default_ld_library_path(); + init_default_namespace(); if (!si->prelink_image()) { - __libc_format_fd(2, "CANNOT LINK EXECUTABLE: %s\n", linker_get_error_buffer()); - exit(EXIT_FAILURE); + __libc_fatal("CANNOT LINK EXECUTABLE: %s", linker_get_error_buffer()); } // add somain to global group @@ -3613,15 +3911,13 @@ static ElfW(Addr) __linker_init_post_relocation(KernelArgumentBlock& args, ElfW( needed_library_name_list.copy_to_array(needed_library_names, needed_libraries_count); if (needed_libraries_count > 0 && - !find_libraries(si, needed_library_names, needed_libraries_count, nullptr, - &g_ld_preloads, ld_preloads_count, RTLD_GLOBAL, nullptr, + !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_format_fd(2, "CANNOT LINK EXECUTABLE: %s\n", linker_get_error_buffer()); - exit(EXIT_FAILURE); + __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_format_fd(2, "CANNOT LINK EXECUTABLE: %s\n", linker_get_error_buffer()); - exit(EXIT_FAILURE); + __libc_fatal("CANNOT LINK EXECUTABLE: %s", linker_get_error_buffer()); } si->increment_ref_count(); } @@ -3730,7 +4026,7 @@ extern "C" ElfW(Addr) __linker_init(void* raw_args) { 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, 0, 0); + 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 @@ -3739,7 +4035,7 @@ extern "C" ElfW(Addr) __linker_init(void* raw_args) { // 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.\n", args.argv[0]); + __libc_fatal("This is %s, the helper program for shared library executables.", args.argv[0]); } linker_so.base = linker_addr; @@ -3757,15 +4053,7 @@ extern "C" ElfW(Addr) __linker_init(void* raw_args) { // 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))) { - // It would be nice to print an error message, but if the linker - // can't link itself, there's no guarantee that we'll be able to - // call write() (because it involves a GOT reference). We may as - // well try though... - const char* msg = "CANNOT LINK EXECUTABLE: "; - write(2, msg, strlen(msg)); - write(2, __linker_dl_err_buf, strlen(__linker_dl_err_buf)); - write(2, "\n", 1); - _exit(EXIT_FAILURE); + __libc_fatal("CANNOT LINK EXECUTABLE: %s", linker_get_error_buffer()); } __libc_init_main_thread(args); @@ -3781,6 +4069,7 @@ extern "C" ElfW(Addr) __linker_init(void* raw_args) { // 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. |