diff options
Diffstat (limited to 'linker/linker.h')
| -rw-r--r-- | linker/linker.h | 286 |
1 files changed, 217 insertions, 69 deletions
diff --git a/linker/linker.h b/linker/linker.h index fa38c7f..dae3972 100644 --- a/linker/linker.h +++ b/linker/linker.h @@ -39,6 +39,9 @@ #include "private/libc_logging.h" #include "linked_list.h" +#include <string> +#include <vector> + #define DL_ERR(fmt, x...) \ do { \ __libc_format_buffer(linker_get_error_buffer(), linker_get_error_buffer_size(), fmt, ##x); \ @@ -87,11 +90,16 @@ #define FLAG_LINKED 0x00000001 #define FLAG_EXE 0x00000004 // The main executable #define FLAG_LINKER 0x00000010 // The linker itself +#define FLAG_GNU_HASH 0x00000040 // uses gnu hash #define FLAG_NEW_SOINFO 0x40000000 // new soinfo format -#define SOINFO_VERSION 0 +#define SUPPORTED_DT_FLAGS_1 (DF_1_NOW | DF_1_GLOBAL | DF_1_NODELETE) + +#define SOINFO_VERSION 2 +#if defined(__arm__) #define SOINFO_NAME_LEN 128 +#endif typedef void (*linker_function_t)(); @@ -103,91 +111,147 @@ typedef void (*linker_function_t)(); struct soinfo; class SoinfoListAllocator { -public: + public: static LinkedListEntry<soinfo>* alloc(); static void free(LinkedListEntry<soinfo>* entry); -private: + + private: // unconstructable DISALLOW_IMPLICIT_CONSTRUCTORS(SoinfoListAllocator); }; +class SymbolName { + public: + explicit SymbolName(const char* name) + : name_(name), has_elf_hash_(false), has_gnu_hash_(false), + elf_hash_(0), gnu_hash_(0) { } + + const char* get_name() { + return name_; + } + + uint32_t elf_hash(); + uint32_t gnu_hash(); + + private: + const char* name_; + bool has_elf_hash_; + bool has_gnu_hash_; + uint32_t elf_hash_; + uint32_t gnu_hash_; + + DISALLOW_IMPLICIT_CONSTRUCTORS(SymbolName); +}; + +struct version_info { + version_info() : elf_hash(0), name(nullptr), target_si(nullptr) {} + + uint32_t elf_hash; + const char* name; + const soinfo* target_si; +}; + +// Class used construct version dependency graph. +class VersionTracker { + public: + VersionTracker() = default; + bool init(const soinfo* si_from); + + const version_info* get_version_info(ElfW(Versym) source_symver) const; + private: + bool init_verneed(const soinfo* si_from); + bool init_verdef(const soinfo* si_from); + void add_version_info(size_t source_index, ElfW(Word) elf_hash, + const char* ver_name, const soinfo* target_si); + + std::vector<version_info> version_infos; + + DISALLOW_COPY_AND_ASSIGN(VersionTracker); +}; + struct soinfo { public: typedef LinkedList<soinfo, SoinfoListAllocator> soinfo_list_t; +#if defined(__arm__) + private: + char old_name_[SOINFO_NAME_LEN]; +#endif public: - char name[SOINFO_NAME_LEN]; const ElfW(Phdr)* phdr; size_t phnum; ElfW(Addr) entry; ElfW(Addr) base; size_t size; -#ifndef __LP64__ +#if defined(__arm__) uint32_t unused1; // DO NOT USE, maintained for compatibility. #endif ElfW(Dyn)* dynamic; -#ifndef __LP64__ +#if defined(__arm__) uint32_t unused2; // DO NOT USE, maintained for compatibility uint32_t unused3; // DO NOT USE, maintained for compatibility #endif soinfo* next; - unsigned flags; - private: - const char* strtab; - public: - ElfW(Sym)* symtab; + uint32_t flags_; - size_t nbucket; - size_t nchain; - unsigned* bucket; - unsigned* chain; + const char* strtab_; + ElfW(Sym)* symtab_; + + size_t nbucket_; + size_t nchain_; + uint32_t* bucket_; + uint32_t* chain_; #if defined(__mips__) || !defined(__LP64__) // This is only used by mips and mips64, but needs to be here for // all 32-bit architectures to preserve binary compatibility. - ElfW(Addr)** plt_got; + ElfW(Addr)** plt_got_; #endif #if defined(USE_RELA) - ElfW(Rela)* plt_rela; - size_t plt_rela_count; + ElfW(Rela)* plt_rela_; + size_t plt_rela_count_; - ElfW(Rela)* rela; - size_t rela_count; + ElfW(Rela)* rela_; + size_t rela_count_; #else - ElfW(Rel)* plt_rel; - size_t plt_rel_count; + ElfW(Rel)* plt_rel_; + size_t plt_rel_count_; - ElfW(Rel)* rel; - size_t rel_count; + ElfW(Rel)* rel_; + size_t rel_count_; #endif - linker_function_t* preinit_array; - size_t preinit_array_count; + linker_function_t* preinit_array_; + size_t preinit_array_count_; - linker_function_t* init_array; - size_t init_array_count; - linker_function_t* fini_array; - size_t fini_array_count; + linker_function_t* init_array_; + size_t init_array_count_; + linker_function_t* fini_array_; + size_t fini_array_count_; - linker_function_t init_func; - linker_function_t fini_func; + linker_function_t init_func_; + linker_function_t fini_func_; #if defined(__arm__) + public: // ARM EABI section used for stack unwinding. - unsigned* ARM_exidx; + uint32_t* ARM_exidx; size_t ARM_exidx_count; + private: #elif defined(__mips__) - unsigned mips_symtabno; - unsigned mips_local_gotno; - unsigned mips_gotsym; -#endif + uint32_t mips_symtabno_; + uint32_t mips_local_gotno_; + uint32_t mips_gotsym_; + bool mips_relocate_got(const soinfo_list_t& global_group, const soinfo_list_t& local_group); - size_t ref_count; +#endif + size_t ref_count_; + public: link_map link_map_head; bool constructors_called; @@ -201,73 +265,157 @@ struct soinfo { #endif bool has_DT_SYMBOLIC; - soinfo(const char* name, const struct stat* file_stat, off64_t file_offset); + public: + soinfo(const char* name, const struct stat* file_stat, off64_t file_offset, int rtld_flags); - void CallConstructors(); - void CallDestructors(); - void CallPreInitConstructors(); - bool PrelinkImage(); - bool LinkImage(const android_dlextinfo* extinfo); + void call_constructors(); + void call_destructors(); + void call_pre_init_constructors(); + bool prelink_image(); + bool link_image(const soinfo_list_t& global_group, const soinfo_list_t& local_group, + const android_dlextinfo* extinfo); void add_child(soinfo* child); void remove_all_links(); - ino_t get_st_ino(); - dev_t get_st_dev(); - off64_t get_file_offset(); + ino_t get_st_ino() const; + dev_t get_st_dev() const; + off64_t get_file_offset() const; + + uint32_t get_rtld_flags() const; + uint32_t get_dt_flags_1() const; + void set_dt_flags_1(uint32_t dt_flags_1); soinfo_list_t& get_children(); + const soinfo_list_t& get_children() const; + soinfo_list_t& get_parents(); - ElfW(Addr) resolve_symbol_address(ElfW(Sym)* s); + bool find_symbol_by_name(SymbolName& symbol_name, + const version_info* vi, + const ElfW(Sym)** symbol) const; + + ElfW(Sym)* find_symbol_by_address(const void* addr); + ElfW(Addr) resolve_symbol_address(const ElfW(Sym)* s) const; const char* get_string(ElfW(Word) index) const; + bool can_unload() const; + bool is_gnu_hash() const; - bool inline has_min_version(uint32_t min_version) const { - return (flags & FLAG_NEW_SOINFO) != 0 && version >= min_version; - } - private: - void CallArray(const char* array_name, linker_function_t* functions, size_t count, bool reverse); - void CallFunction(const char* function_name, linker_function_t function); -#if defined(USE_RELA) - int Relocate(ElfW(Rela)* rela, unsigned count); + bool inline has_min_version(uint32_t min_version __unused) const { +#if defined(__arm__) + return (flags_ & FLAG_NEW_SOINFO) != 0 && version_ >= min_version; #else - int Relocate(ElfW(Rel)* rel, unsigned count); + return true; #endif + } + + bool is_linked() const; + bool is_main_executable() const; + + void set_linked(); + void set_linker_flag(); + void set_main_executable(); + + void increment_ref_count(); + size_t decrement_ref_count(); + + soinfo* get_local_group_root() const; + + const char* get_soname() const; + const char* get_realpath() const; + const ElfW(Versym)* get_versym(size_t n) const; + ElfW(Addr) get_verneed_ptr() const; + size_t get_verneed_cnt() const; + ElfW(Addr) get_verdef_ptr() const; + size_t get_verdef_cnt() const; + + bool find_verdef_version_index(const version_info* vi, ElfW(Versym)* versym) const; + + private: + bool elf_lookup(SymbolName& symbol_name, const version_info* vi, uint32_t* symbol_index) const; + ElfW(Sym)* elf_addr_lookup(const void* addr); + bool gnu_lookup(SymbolName& symbol_name, const version_info* vi, uint32_t* symbol_index) const; + ElfW(Sym)* gnu_addr_lookup(const void* addr); + + void call_array(const char* array_name, linker_function_t* functions, size_t count, bool reverse); + void call_function(const char* function_name, linker_function_t function); + template<typename ElfRelIteratorT> + bool relocate(ElfRelIteratorT&& rel_iterator, const soinfo_list_t& global_group, + const soinfo_list_t& local_group); private: // This part of the structure is only available // when FLAG_NEW_SOINFO is set in this->flags. - uint32_t version; + uint32_t version_; // version >= 0 - dev_t st_dev; - ino_t st_ino; + dev_t st_dev_; + ino_t st_ino_; // dependency graph - soinfo_list_t children; - soinfo_list_t parents; + soinfo_list_t children_; + soinfo_list_t parents_; // version >= 1 - off64_t file_offset; - int rtld_flags; - size_t strtab_size; + off64_t file_offset_; + uint32_t rtld_flags_; + uint32_t dt_flags_1_; + size_t strtab_size_; + + // version >= 2 + + size_t gnu_nbucket_; + uint32_t* gnu_bucket_; + uint32_t* gnu_chain_; + uint32_t gnu_maskwords_; + uint32_t gnu_shift2_; + ElfW(Addr)* gnu_bloom_filter_; + + soinfo* local_group_root_; + + uint8_t* android_relocs_; + size_t android_relocs_size_; + + const char* soname_; + std::string realpath_; + + const ElfW(Versym)* versym_; + + ElfW(Addr) verdef_ptr_; + size_t verdef_cnt_; + + ElfW(Addr) verneed_ptr_; + size_t verneed_cnt_; friend soinfo* get_libdl_info(); }; -extern soinfo* get_libdl_info(); +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); + +enum RelocationKind { + kRelocAbsolute = 0, + kRelocRelative, + kRelocCopy, + kRelocSymbol, + kRelocMax +}; + +void count_relocation(RelocationKind kind); + +soinfo* get_libdl_info(); void do_android_get_LD_LIBRARY_PATH(char*, size_t); void do_android_update_LD_LIBRARY_PATH(const char* ld_library_path); soinfo* do_dlopen(const char* name, int flags, const android_dlextinfo* extinfo); void do_dlclose(soinfo* si); -ElfW(Sym)* dlsym_linear_lookup(const char* name, soinfo** found, soinfo* start); +const ElfW(Sym)* dlsym_linear_lookup(const char* name, soinfo** found, soinfo* caller, void* handle); soinfo* find_containing_library(const void* addr); -ElfW(Sym)* dladdr_find_symbol(soinfo* si, const void* addr); -ElfW(Sym)* dlsym_handle_lookup(soinfo* si, soinfo** found, const char* name); +const ElfW(Sym)* dlsym_handle_lookup(soinfo* si, soinfo** found, const char* name); void debuggerd_init(); extern "C" abort_msg_t* g_abort_message; |