rtld.h revision 346156
140939Sdes/*- 240939Sdes * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 340939Sdes * All rights reserved. 440939Sdes * 540939Sdes * Redistribution and use in source and binary forms, with or without 640939Sdes * modification, are permitted provided that the following conditions 740939Sdes * are met: 840939Sdes * 1. Redistributions of source code must retain the above copyright 940939Sdes * notice, this list of conditions and the following disclaimer. 1040939Sdes * 2. Redistributions in binary form must reproduce the above copyright 1140939Sdes * notice, this list of conditions and the following disclaimer in the 1240939Sdes * documentation and/or other materials provided with the distribution. 1340939Sdes * 1440939Sdes * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1540939Sdes * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1640939Sdes * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1740939Sdes * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1840939Sdes * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 1940939Sdes * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2040939Sdes * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2140939Sdes * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2240939Sdes * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2340939Sdes * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2440939Sdes * 2540939Sdes * $FreeBSD: stable/11/libexec/rtld-elf/rtld.h 346156 2019-04-12 15:15:27Z kib $ 2640939Sdes */ 2740939Sdes 2850476Speter#ifndef RTLD_H /* { */ 2940939Sdes#define RTLD_H 1 3040939Sdes 3141862Sdes#include <machine/elf.h> 3240939Sdes#include <sys/types.h> 3355557Sdes#include <sys/queue.h> 3462981Sdes 3540939Sdes#include <elf-hints.h> 3640939Sdes#include <link.h> 3740939Sdes#include <stdarg.h> 3840939Sdes#include <setjmp.h> 3960924Sdes#include <stddef.h> 4041862Sdes 4141862Sdes#include "rtld_lock.h" 4240939Sdes#include "rtld_machdep.h" 4340939Sdes 4440939Sdes#define NEW(type) ((type *) xmalloc(sizeof(type))) 4540939Sdes#define CNEW(type) ((type *) xcalloc(1, sizeof(type))) 4640939Sdes 4740939Sdes/* We might as well do booleans like C++. */ 4840975Sdestypedef unsigned char bool; 4940939Sdes#define false 0 5040939Sdes#define true 1 5140939Sdes 5240939Sdesextern size_t tls_last_offset; 5340939Sdesextern size_t tls_last_size; 5440939Sdesextern size_t tls_static_space; 5560737Sumeextern int tls_dtv_generation; 5660737Sumeextern int tls_max_index; 5760737Sume 5860737Sumeextern int npagesizes; 5940975Sdesextern size_t *pagesizes; 6040939Sdes 6140939Sdesextern int main_argc; 6262981Sdesextern char **main_argv; 6362981Sdesextern char **environ; 6440939Sdes 6562981Sdesstruct stat; 6640939Sdesstruct Struct_Obj_Entry; 6740939Sdes 6840939Sdes/* Lists of shared objects */ 6940939Sdestypedef struct Struct_Objlist_Entry { 7040939Sdes STAILQ_ENTRY(Struct_Objlist_Entry) link; 7160924Sdes struct Struct_Obj_Entry *obj; 7240975Sdes} Objlist_Entry; 7340939Sdes 7460924Sdestypedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 7560924Sdes 7660924Sdes/* Types of init and fini functions */ 7740939Sdestypedef void (*InitFunc)(void); 7840939Sdestypedef void (*InitArrFunc)(int, char **, char **); 7940939Sdes 8040939Sdes/* Lists of shared object dependencies */ 8140939Sdestypedef struct Struct_Needed_Entry { 8240939Sdes struct Struct_Needed_Entry *next; 8340939Sdes struct Struct_Obj_Entry *obj; 8440939Sdes unsigned long name; /* Offset of name in string table */ 8560924Sdes} Needed_Entry; 8660924Sdes 8760924Sdestypedef struct Struct_Name_Entry { 8840939Sdes STAILQ_ENTRY(Struct_Name_Entry) link; 8940939Sdes char name[1]; 9040939Sdes} Name_Entry; 9140939Sdes 9240939Sdes/* Lock object */ 9340939Sdestypedef struct Struct_LockInfo { 9440939Sdes void *context; /* Client context for creating locks */ 9540939Sdes void *thelock; /* The one big lock */ 9641862Sdes /* Debugging aids. */ 9741862Sdes volatile int rcount; /* Number of readers holding lock */ 9840975Sdes volatile int wcount; /* Number of writers holding lock */ 9940975Sdes /* Methods */ 10040975Sdes void *(*lock_create)(void *context); 10141862Sdes void (*rlock_acquire)(void *lock); 10240975Sdes void (*wlock_acquire)(void *lock); 10340975Sdes void (*rlock_release)(void *lock); 10440975Sdes void (*wlock_release)(void *lock); 10540975Sdes void (*lock_destroy)(void *lock); 10640975Sdes void (*context_destroy)(void *context); 10740975Sdes} LockInfo; 10841862Sdes 10940975Sdestypedef struct Struct_Ver_Entry { 11040975Sdes Elf_Word hash; 11140975Sdes unsigned int flags; 11241862Sdes const char *name; 11340975Sdes const char *file; 11440975Sdes} Ver_Entry; 11541862Sdes 11640975Sdestypedef struct Struct_Sym_Match_Result { 11740975Sdes const Elf_Sym *sym_out; 11840975Sdes const Elf_Sym *vsymp; 11941862Sdes int vcount; 12040975Sdes} Sym_Match_Result; 12140975Sdes 12241862Sdes#define VER_INFO_HIDDEN 0x01 12340975Sdes 12440975Sdes/* 12541862Sdes * Shared object descriptor. 12640975Sdes * 12740975Sdes * Items marked with "(%)" are dynamically allocated, and must be freed 12840975Sdes * when the structure is destroyed. 12940975Sdes * 13040975Sdes * CAUTION: It appears that the JDK port peeks into these structures. 13140975Sdes * It looks at "next" and "mapbase" at least. Don't add new members 13240975Sdes * near the front, until this can be straightened out. 13341862Sdes */ 13440975Sdestypedef struct Struct_Obj_Entry { 13540975Sdes /* 13640975Sdes * These two items have to be set right for compatibility with the 13741862Sdes * original ElfKit crt1.o. 13840975Sdes */ 13940975Sdes Elf_Size magic; /* Magic number (sanity check) */ 14041862Sdes Elf_Size version; /* Version number of struct format */ 14140975Sdes 14240975Sdes TAILQ_ENTRY(Struct_Obj_Entry) next; 14340975Sdes char *path; /* Pathname of underlying file (%) */ 14441862Sdes char *origin_path; /* Directory path of origin file */ 14540975Sdes int refcount; /* DAG references */ 14640975Sdes int holdcount; /* Count of transient references */ 14741862Sdes int dl_refcount; /* Number of times loaded by dlopen */ 14840975Sdes 14960924Sdes /* These items are computed by map_object() or by digest_phdr(). */ 15040939Sdes caddr_t mapbase; /* Base address of mapped region */ 15140939Sdes size_t mapsize; /* Size of mapped region in bytes */ 15240939Sdes size_t textsize; /* Size of text segment in bytes */ 15341862Sdes Elf_Addr vaddrbase; /* Base address in shared object file */ 15441862Sdes caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 15541862Sdes const Elf_Dyn *dynamic; /* Dynamic section */ 15660924Sdes caddr_t entry; /* Entry point */ 15741862Sdes const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 15841862Sdes size_t phsize; /* Size of program header in bytes */ 15941862Sdes const char *interp; /* Pathname of the interpreter, if any */ 16041862Sdes Elf_Word stack_flags; 16141862Sdes 16260924Sdes /* TLS information */ 16341862Sdes int tlsindex; /* Index in DTV for this module */ 16460928Sdes void *tlsinit; /* Base address of TLS init block */ 16541862Sdes size_t tlsinitsize; /* Size of TLS init block for this module */ 16641862Sdes size_t tlssize; /* Size of TLS block for this module */ 16741862Sdes size_t tlsoffset; /* Offset of static TLS block for this module */ 16840939Sdes size_t tlsalign; /* Alignment of static TLS block */ 16940939Sdes 17040939Sdes caddr_t relro_page; 17140939Sdes size_t relro_size; 17240939Sdes 17340939Sdes /* Items from the dynamic section. */ 17460737Sume Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ 17540939Sdes const Elf_Rel *rel; /* Relocation entries */ 17660737Sume unsigned long relsize; /* Size in bytes of relocation info */ 17760737Sume const Elf_Rela *rela; /* Relocation entries with addend */ 17860737Sume unsigned long relasize; /* Size in bytes of addend relocation info */ 17940939Sdes const Elf_Rel *pltrel; /* PLT relocation entries */ 18062964Sdes unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ 18141862Sdes const Elf_Rela *pltrela; /* PLT relocation entries with addend */ 18241862Sdes unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ 18341862Sdes const Elf_Sym *symtab; /* Symbol table */ 18440939Sdes const char *strtab; /* String table */ 18560737Sume unsigned long strsize; /* Size in bytes of string table */ 18660737Sume#ifdef __mips__ 18760737Sume Elf_Word local_gotno; /* Number of local GOT entries */ 18860737Sume Elf_Word symtabno; /* Number of dynamic symbols */ 18960737Sume Elf_Word gotsym; /* First dynamic symbol in GOT */ 19060737Sume#endif 19160737Sume#ifdef __powerpc64__ 19260737Sume Elf_Addr glink; /* GLINK PLT call stub section */ 19340939Sdes#endif 19440939Sdes 19540939Sdes const Elf_Verneed *verneed; /* Required versions. */ 19641862Sdes Elf_Word verneednum; /* Number of entries in verneed table */ 19741862Sdes const Elf_Verdef *verdef; /* Provided versions. */ 19841862Sdes Elf_Word verdefnum; /* Number of entries in verdef table */ 19940939Sdes const Elf_Versym *versyms; /* Symbol versions table */ 20062981Sdes 20160737Sume const Elf_Hashelt *buckets; /* Hash table buckets array */ 20262981Sdes unsigned long nbuckets; /* Number of buckets */ 20360737Sume const Elf_Hashelt *chains; /* Hash table chain array */ 20462981Sdes unsigned long nchains; /* Number of entries in chain array */ 20560737Sume 20660737Sume Elf32_Word nbuckets_gnu; /* Number of GNU hash buckets*/ 20760737Sume Elf32_Word symndx_gnu; /* 1st accessible symbol on dynsym table */ 20840939Sdes Elf32_Word maskwords_bm_gnu; /* Bloom filter words - 1 (bitmask) */ 20962911Sume Elf32_Word shift2_gnu; /* Bloom filter shift count */ 21062981Sdes Elf32_Word dynsymcount; /* Total entries in dynsym table */ 21140939Sdes Elf_Addr *bloom_gnu; /* Bloom filter used by GNU hash func */ 21240939Sdes const Elf_Hashelt *buckets_gnu; /* GNU hash table bucket array */ 21340939Sdes const Elf_Hashelt *chain_zero_gnu; /* GNU hash table value array (Zeroed) */ 21440939Sdes 21540939Sdes char *rpath; /* Search path specified in object */ 21640939Sdes char *runpath; /* Search path with different priority */ 21741989Sdes Needed_Entry *needed; /* Shared objects needed by this one (%) */ 21841989Sdes Needed_Entry *needed_filtees; 21955557Sdes Needed_Entry *needed_aux_filtees; 22055557Sdes 22155557Sdes STAILQ_HEAD(, Struct_Name_Entry) names; /* List of names for this object we 22255557Sdes know about. */ 22355557Sdes Ver_Entry *vertab; /* Versions required /defined by this object */ 22455557Sdes int vernum; /* Number of entries in vertab */ 22555557Sdes 22655557Sdes Elf_Addr init; /* Initialization function to call */ 22755557Sdes Elf_Addr fini; /* Termination function to call */ 22855557Sdes Elf_Addr preinit_array; /* Pre-initialization array of functions */ 22955557Sdes Elf_Addr init_array; /* Initialization array of functions */ 23055557Sdes Elf_Addr fini_array; /* Termination array of functions */ 23155557Sdes int preinit_array_num; /* Number of entries in preinit_array */ 23255557Sdes int init_array_num; /* Number of entries in init_array */ 23355557Sdes int fini_array_num; /* Number of entries in fini_array */ 23455557Sdes 23555557Sdes int32_t osrel; /* OSREL note value */ 23655557Sdes 23755557Sdes bool mainprog : 1; /* True if this is the main program */ 23855557Sdes bool rtld : 1; /* True if this is the dynamic linker */ 23955557Sdes bool relocated : 1; /* True if processed by relocate_objects() */ 24055557Sdes bool ver_checked : 1; /* True if processed by rtld_verify_object_versions */ 24155557Sdes bool textrel : 1; /* True if there are relocations to text seg */ 24255557Sdes bool symbolic : 1; /* True if generated with "-Bsymbolic" */ 24355557Sdes bool bind_now : 1; /* True if all relocations should be made first */ 24455557Sdes bool traced : 1; /* Already printed in ldd trace output */ 24555557Sdes bool jmpslots_done : 1; /* Already have relocated the jump slots */ 24655557Sdes bool init_done : 1; /* Already have added object to init list */ 24755557Sdes bool tls_done : 1; /* Already allocated offset for static TLS */ 24855557Sdes bool phdr_alloc : 1; /* Phdr is allocated and needs to be freed. */ 24955557Sdes bool z_origin : 1; /* Process rpath and soname tokens */ 25055557Sdes bool z_nodelete : 1; /* Do not unload the object and dependencies */ 25155557Sdes bool z_noopen : 1; /* Do not load on dlopen */ 25255557Sdes bool z_loadfltr : 1; /* Immediately load filtees */ 25355557Sdes bool z_interpose : 1; /* Interpose all objects but main */ 25455557Sdes bool z_nodeflib : 1; /* Don't search default library path */ 25555557Sdes bool z_global : 1; /* Make the object global */ 25655557Sdes bool static_tls : 1; /* Needs static TLS allocation */ 25755557Sdes bool static_tls_copied : 1; /* Needs static TLS copying */ 25855557Sdes bool ref_nodel : 1; /* Refcount increased to prevent dlclose */ 25955557Sdes bool init_scanned: 1; /* Object is already on init list. */ 26055557Sdes bool on_fini_list: 1; /* Object is already on fini list. */ 26155557Sdes bool dag_inited : 1; /* Object has its DAG initialized. */ 26255557Sdes bool filtees_loaded : 1; /* Filtees loaded */ 26355557Sdes bool irelative : 1; /* Object has R_MACHDEP_IRELATIVE relocs */ 26455557Sdes bool gnu_ifunc : 1; /* Object has references to STT_GNU_IFUNC */ 26563334Sdes bool non_plt_gnu_ifunc : 1; /* Object has non-plt IFUNC references */ 26655557Sdes bool ifuncs_resolved : 1; /* Object ifuncs were already resolved */ 26755557Sdes bool crt_no_init : 1; /* Object' crt does not call _init/_fini */ 26855557Sdes bool valid_hash_sysv : 1; /* A valid System V hash hash tag is available */ 26955557Sdes bool valid_hash_gnu : 1; /* A valid GNU hash tag is available */ 27055557Sdes bool dlopened : 1; /* dlopen()-ed (vs. load statically) */ 27155557Sdes bool marker : 1; /* marker on the global obj list */ 27255557Sdes bool unholdfree : 1; /* unmap upon last unhold */ 27355557Sdes bool doomed : 1; /* Object cannot be referenced */ 27455557Sdes 27555557Sdes struct link_map linkmap; /* For GDB and dlinfo() */ 27655557Sdes Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 27763334Sdes Objlist dagmembers; /* DAG has these members (%) */ 27855557Sdes dev_t dev; /* Object's filesystem's device */ 27955557Sdes ino_t ino; /* Object's inode number */ 28055557Sdes void *priv; /* Platform-dependent */ 28155557Sdes} Obj_Entry; 28255557Sdes 28355557Sdes#define RTLD_MAGIC 0xd550b87a 28455557Sdes#define RTLD_VERSION 1 28555557Sdes 28655557SdesTAILQ_HEAD(obj_entry_q, Struct_Obj_Entry); 28755557Sdes 28855557Sdes#define RTLD_STATIC_TLS_EXTRA 128 28955557Sdes 29055557Sdes/* Flags to be passed into symlook_ family of functions. */ 29155557Sdes#define SYMLOOK_IN_PLT 0x01 /* Lookup for PLT symbol */ 29255557Sdes#define SYMLOOK_DLSYM 0x02 /* Return newest versioned symbol. Used by 29355557Sdes dlsym. */ 29455557Sdes#define SYMLOOK_EARLY 0x04 /* Symlook is done during initialization. */ 29555557Sdes#define SYMLOOK_IFUNC 0x08 /* Allow IFUNC processing in 29662964Sdes reloc_non_plt(). */ 29755557Sdes 29855557Sdes/* Flags for load_object(). */ 29955557Sdes#define RTLD_LO_NOLOAD 0x01 /* dlopen() specified RTLD_NOLOAD. */ 30055557Sdes#define RTLD_LO_DLOPEN 0x02 /* Load_object() called from dlopen(). */ 30162981Sdes#define RTLD_LO_TRACE 0x04 /* Only tracing. */ 30262981Sdes#define RTLD_LO_NODELETE 0x08 /* Loaded object cannot be closed. */ 30362981Sdes#define RTLD_LO_FILTEES 0x10 /* Loading filtee. */ 30462981Sdes#define RTLD_LO_EARLY 0x20 /* Do not call ctors, postpone it to the 30562981Sdes initialization during the image start. */ 30662981Sdes 30762981Sdes/* 30862981Sdes * Symbol cache entry used during relocation to avoid multiple lookups 30962981Sdes * of the same symbol. 31062981Sdes */ 31162981Sdestypedef struct Struct_SymCache { 31262981Sdes const Elf_Sym *sym; /* Symbol table entry */ 31362981Sdes const Obj_Entry *obj; /* Shared object which defines it */ 31462981Sdes} SymCache; 31562981Sdes 31662981Sdes/* 31762981Sdes * This structure provides a reentrant way to keep a list of objects and 31862981Sdes * check which ones have already been processed in some way. 31962981Sdes */ 32062981Sdestypedef struct Struct_DoneList { 32162981Sdes const Obj_Entry **objs; /* Array of object pointers */ 32241989Sdes unsigned int num_alloc; /* Allocated size of the array */ 32341989Sdes unsigned int num_used; /* Number of array slots used */ 32441989Sdes} DoneList; 32541989Sdes 32641989Sdesstruct Struct_RtldLockState { 32741989Sdes int lockstate; 32841989Sdes sigjmp_buf env; 32941989Sdes}; 33041989Sdes 33141989Sdesstruct fill_search_info_args { 33241989Sdes int request; 33341989Sdes unsigned int flags; 33441989Sdes struct dl_serinfo *serinfo; 33541989Sdes struct dl_serpath *serpath; 33641989Sdes char *strspace; 33741989Sdes}; 33841989Sdes 33941989Sdes/* 34041989Sdes * The pack of arguments and results for the symbol lookup functions. 34141989Sdes */ 34241989Sdestypedef struct Struct_SymLook { 34341989Sdes const char *name; 34441989Sdes unsigned long hash; 34541989Sdes uint32_t hash_gnu; 34641989Sdes const Ver_Entry *ventry; 34741989Sdes int flags; 34841989Sdes const Obj_Entry *defobj_out; 34941989Sdes const Elf_Sym *sym_out; 35041989Sdes struct Struct_RtldLockState *lockstate; 35141989Sdes} SymLook; 35241989Sdes 35341989Sdesvoid _rtld_error(const char *, ...) __printflike(1, 2) __exported; 35441989Sdesvoid rtld_die(void) __dead2; 35541989Sdesconst char *rtld_strerror(int); 35641989SdesObj_Entry *map_object(int, const char *, const struct stat *); 35741989Sdesvoid *xcalloc(size_t, size_t); 35841989Sdesvoid *xmalloc(size_t); 35941989Sdeschar *xstrdup(const char *); 36041989Sdesvoid *malloc_aligned(size_t size, size_t align); 36141989Sdesvoid free_aligned(void *ptr); 362extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 363extern Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 364extern bool ld_bind_not; 365 366void dump_relocations(Obj_Entry *); 367void dump_obj_relocations(Obj_Entry *); 368void dump_Elf_Rel(Obj_Entry *, const Elf_Rel *, u_long); 369void dump_Elf_Rela(Obj_Entry *, const Elf_Rela *, u_long); 370 371/* 372 * Function declarations. 373 */ 374unsigned long elf_hash(const char *); 375const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, 376 const Obj_Entry **, int, SymCache *, struct Struct_RtldLockState *); 377void lockdflt_init(void); 378void digest_notes(Obj_Entry *, Elf_Addr, Elf_Addr); 379Obj_Entry *globallist_curr(const Obj_Entry *obj); 380Obj_Entry *globallist_next(const Obj_Entry *obj); 381void obj_free(Obj_Entry *); 382Obj_Entry *obj_new(void); 383void _rtld_bind_start(void); 384void *rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def); 385void symlook_init(SymLook *, const char *); 386int symlook_obj(SymLook *, const Obj_Entry *); 387void *tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset); 388void *allocate_tls(Obj_Entry *, void *, size_t, size_t); 389void free_tls(void *, size_t, size_t); 390void *allocate_module_tls(int index); 391bool allocate_tls_offset(Obj_Entry *obj); 392void free_tls_offset(Obj_Entry *obj); 393const Ver_Entry *fetch_ventry(const Obj_Entry *obj, unsigned long); 394int convert_prot(int elfflags); 395 396/* 397 * MD function declarations. 398 */ 399int do_copy_relocations(Obj_Entry *); 400int reloc_non_plt(Obj_Entry *, Obj_Entry *, int flags, 401 struct Struct_RtldLockState *); 402int reloc_plt(Obj_Entry *); 403int reloc_jmpslots(Obj_Entry *, int flags, struct Struct_RtldLockState *); 404int reloc_iresolve(Obj_Entry *, struct Struct_RtldLockState *); 405int reloc_gnu_ifunc(Obj_Entry *, int flags, struct Struct_RtldLockState *); 406void ifunc_init(Elf_Auxinfo[__min_size(AT_COUNT)]); 407void pre_init(void); 408void init_pltgot(Obj_Entry *); 409void allocate_initial_tls(Obj_Entry *); 410 411#endif /* } */ 412