rtld.h revision 190543
134192Sjdp/*- 255687Sjdp * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. 334192Sjdp * All rights reserved. 434192Sjdp * 534192Sjdp * Redistribution and use in source and binary forms, with or without 634192Sjdp * modification, are permitted provided that the following conditions 734192Sjdp * are met: 834192Sjdp * 1. Redistributions of source code must retain the above copyright 934192Sjdp * notice, this list of conditions and the following disclaimer. 1034192Sjdp * 2. Redistributions in binary form must reproduce the above copyright 1134192Sjdp * notice, this list of conditions and the following disclaimer in the 1234192Sjdp * documentation and/or other materials provided with the distribution. 1334192Sjdp * 1434192Sjdp * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 1534192Sjdp * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 1634192Sjdp * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 1734192Sjdp * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 1834192Sjdp * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 1934192Sjdp * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 2034192Sjdp * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 2134192Sjdp * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 2234192Sjdp * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 2334192Sjdp * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 2434192Sjdp * 2550476Speter * $FreeBSD: head/libexec/rtld-elf/rtld.h 190543 2009-03-30 08:47:28Z kib $ 2634192Sjdp */ 2734192Sjdp 2834192Sjdp#ifndef RTLD_H /* { */ 2934192Sjdp#define RTLD_H 1 3034192Sjdp 3176224Sobrien#include <machine/elf.h> 3234192Sjdp#include <sys/types.h> 3350608Sjdp#include <sys/queue.h> 3434192Sjdp 3576224Sobrien#include <elf-hints.h> 3635529Sdfr#include <link.h> 3734192Sjdp#include <stddef.h> 3834192Sjdp 39115396Skan#include "rtld_lock.h" 4045501Sjdp#include "rtld_machdep.h" 4145501Sjdp 42127250Speter#ifdef COMPAT_32BIT 43127250Speter#undef STANDARD_LIBRARY_PATH 44127250Speter#undef _PATH_ELF_HINTS 45127250Speter#define _PATH_ELF_HINTS "/var/run/ld-elf32.so.hints" 46127250Speter/* For running 32 bit binaries */ 47127250Speter#define STANDARD_LIBRARY_PATH "/lib32:/usr/lib32" 48127250Speter#define LD_ "LD_32_" 49127250Speter#endif 50127250Speter 5134192Sjdp#ifndef STANDARD_LIBRARY_PATH 52119013Sgordon#define STANDARD_LIBRARY_PATH "/lib:/usr/lib" 5334192Sjdp#endif 54127250Speter#ifndef LD_ 55127250Speter#define LD_ "LD_" 56127250Speter#endif 5734192Sjdp 5834192Sjdp#define NEW(type) ((type *) xmalloc(sizeof(type))) 5934192Sjdp#define CNEW(type) ((type *) xcalloc(sizeof(type))) 6034192Sjdp 6134192Sjdp/* We might as well do booleans like C++. */ 6234192Sjdptypedef unsigned char bool; 6334192Sjdp#define false 0 6434192Sjdp#define true 1 6534192Sjdp 66133063Sdfrextern size_t tls_last_offset; 67133063Sdfrextern size_t tls_last_size; 68133063Sdfrextern size_t tls_static_space; 69133063Sdfrextern int tls_dtv_generation; 70133063Sdfrextern int tls_max_index; 71133063Sdfr 7250609Sjdpstruct stat; 7334192Sjdpstruct Struct_Obj_Entry; 7434192Sjdp 7555687Sjdp/* Lists of shared objects */ 7650608Sjdptypedef struct Struct_Objlist_Entry { 7760938Sjake STAILQ_ENTRY(Struct_Objlist_Entry) link; 7850608Sjdp struct Struct_Obj_Entry *obj; 7950608Sjdp} Objlist_Entry; 8050608Sjdp 8160938Sjaketypedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 8250608Sjdp 8363870Sjdp/* Types of init and fini functions */ 8455687Sjdptypedef void (*InitFunc)(void); 8555687Sjdp 8655687Sjdp/* Lists of shared object dependencies */ 8734192Sjdptypedef struct Struct_Needed_Entry { 8834192Sjdp struct Struct_Needed_Entry *next; 8934192Sjdp struct Struct_Obj_Entry *obj; 9034192Sjdp unsigned long name; /* Offset of name in string table */ 9134192Sjdp} Needed_Entry; 9234192Sjdp 93153515Skantypedef struct Struct_Name_Entry { 94153515Skan STAILQ_ENTRY(Struct_Name_Entry) link; 95153515Skan char name[1]; 96153515Skan} Name_Entry; 97153515Skan 9862801Sjdp/* Lock object */ 9962801Sjdptypedef struct Struct_LockInfo { 10062801Sjdp void *context; /* Client context for creating locks */ 10162801Sjdp void *thelock; /* The one big lock */ 10262801Sjdp /* Debugging aids. */ 10362801Sjdp volatile int rcount; /* Number of readers holding lock */ 10462801Sjdp volatile int wcount; /* Number of writers holding lock */ 10562801Sjdp /* Methods */ 10662801Sjdp void *(*lock_create)(void *context); 10762801Sjdp void (*rlock_acquire)(void *lock); 10862801Sjdp void (*wlock_acquire)(void *lock); 10962801Sjdp void (*rlock_release)(void *lock); 11062801Sjdp void (*wlock_release)(void *lock); 11162801Sjdp void (*lock_destroy)(void *lock); 11262801Sjdp void (*context_destroy)(void *context); 11362801Sjdp} LockInfo; 11462801Sjdp 115153515Skantypedef struct Struct_Ver_Entry { 116153515Skan Elf_Word hash; 117153515Skan unsigned int flags; 118153515Skan const char *name; 119153515Skan const char *file; 120153515Skan} Ver_Entry; 121153515Skan 122153515Skan#define VER_INFO_HIDDEN 0x01 123153515Skan 12434192Sjdp/* 12534192Sjdp * Shared object descriptor. 12634192Sjdp * 12734192Sjdp * Items marked with "(%)" are dynamically allocated, and must be freed 12834192Sjdp * when the structure is destroyed. 12950977Sjdp * 13050977Sjdp * CAUTION: It appears that the JDK port peeks into these structures. 13150977Sjdp * It looks at "next" and "mapbase" at least. Don't add new members 13250977Sjdp * near the front, until this can be straightened out. 13334192Sjdp */ 13434192Sjdptypedef struct Struct_Obj_Entry { 13534192Sjdp /* 13634192Sjdp * These two items have to be set right for compatibility with the 13734192Sjdp * original ElfKit crt1.o. 13834192Sjdp */ 139153504Smarcel Elf_Size magic; /* Magic number (sanity check) */ 140153504Smarcel Elf_Size version; /* Version number of struct format */ 14134192Sjdp 14234192Sjdp struct Struct_Obj_Entry *next; 14334192Sjdp char *path; /* Pathname of underlying file (%) */ 144116511Smdodd char *origin_path; /* Directory path of origin file */ 14534192Sjdp int refcount; 14634192Sjdp int dl_refcount; /* Number of times loaded by dlopen */ 14734192Sjdp 14834192Sjdp /* These items are computed by map_object() or by digest_phdr(). */ 14934192Sjdp caddr_t mapbase; /* Base address of mapped region */ 15034192Sjdp size_t mapsize; /* Size of mapped region in bytes */ 15134192Sjdp size_t textsize; /* Size of text segment in bytes */ 15238467Sjb Elf_Addr vaddrbase; /* Base address in shared object file */ 15334192Sjdp caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 15438467Sjb const Elf_Dyn *dynamic; /* Dynamic section */ 15534192Sjdp caddr_t entry; /* Entry point */ 15638467Sjb const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 15734192Sjdp size_t phsize; /* Size of program header in bytes */ 15850610Sjdp const char *interp; /* Pathname of the interpreter, if any */ 15934192Sjdp 160133063Sdfr /* TLS information */ 161133063Sdfr int tlsindex; /* Index in DTV for this module */ 162133063Sdfr void *tlsinit; /* Base address of TLS init block */ 163133063Sdfr size_t tlsinitsize; /* Size of TLS init block for this module */ 164133063Sdfr size_t tlssize; /* Size of TLS block for this module */ 165133063Sdfr size_t tlsoffset; /* Offset of static TLS block for this module */ 166133063Sdfr size_t tlsalign; /* Alignment of static TLS block */ 167133063Sdfr 16834192Sjdp /* Items from the dynamic section. */ 16945501Sjdp Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ 17038467Sjb const Elf_Rel *rel; /* Relocation entries */ 17134192Sjdp unsigned long relsize; /* Size in bytes of relocation info */ 17238816Sdfr const Elf_Rela *rela; /* Relocation entries with addend */ 17338816Sdfr unsigned long relasize; /* Size in bytes of addend relocation info */ 17438467Sjb const Elf_Rel *pltrel; /* PLT relocation entries */ 17534192Sjdp unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ 17638816Sdfr const Elf_Rela *pltrela; /* PLT relocation entries with addend */ 17738816Sdfr unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ 17838467Sjb const Elf_Sym *symtab; /* Symbol table */ 17934192Sjdp const char *strtab; /* String table */ 18034192Sjdp unsigned long strsize; /* Size in bytes of string table */ 181177924Simp#ifdef __mips__ 182177924Simp Elf_Word local_gotno; /* Number of local GOT entries */ 183177924Simp Elf_Word symtabno; /* Number of dynamic symbols */ 184177924Simp Elf_Word gotsym; /* First dynamic symbol in GOT */ 185177924Simp#endif 18634192Sjdp 187153515Skan const Elf_Verneed *verneed; /* Required versions. */ 188153515Skan Elf_Word verneednum; /* Number of entries in verneed table */ 189153515Skan const Elf_Verdef *verdef; /* Provided versions. */ 190153515Skan Elf_Word verdefnum; /* Number of entries in verdef table */ 191153515Skan const Elf_Versym *versyms; /* Symbol versions table */ 192153515Skan 19385004Sdfr const Elf_Hashelt *buckets; /* Hash table buckets array */ 19434192Sjdp unsigned long nbuckets; /* Number of buckets */ 19585004Sdfr const Elf_Hashelt *chains; /* Hash table chain array */ 19634192Sjdp unsigned long nchains; /* Number of chains */ 19734192Sjdp 198189959Skib char *rpath; /* Search path specified in object */ 19934192Sjdp Needed_Entry *needed; /* Shared objects needed by this one (%) */ 20034192Sjdp 201153515Skan STAILQ_HEAD(, Struct_Name_Entry) names; /* List of names for this object we 202153515Skan know about. */ 203153515Skan Ver_Entry *vertab; /* Versions required /defined by this object */ 204153515Skan int vernum; /* Number of entries in vertab */ 205153515Skan 20685677Speter Elf_Addr init; /* Initialization function to call */ 20785677Speter Elf_Addr fini; /* Termination function to call */ 20834192Sjdp 209168312Skan bool mainprog : 1; /* True if this is the main program */ 210168312Skan bool rtld : 1; /* True if this is the dynamic linker */ 211168312Skan bool textrel : 1; /* True if there are relocations to text seg */ 212168312Skan bool symbolic : 1; /* True if generated with "-Bsymbolic" */ 213168312Skan bool bind_now : 1; /* True if all relocations should be made first */ 214168312Skan bool traced : 1; /* Already printed in ldd trace output */ 215168312Skan bool jmpslots_done : 1; /* Already have relocated the jump slots */ 216168312Skan bool init_done : 1; /* Already have added object to init list */ 217168312Skan bool tls_done : 1; /* Already allocated offset for static TLS */ 218168312Skan bool phdr_alloc : 1; /* Phdr is allocated and needs to be freed. */ 219189959Skib bool z_origin : 1; /* Process rpath and soname tokens */ 220190543Skib bool z_nodelete : 1; /* Do not unload the object and dependencies */ 221190543Skib bool ref_nodel : 1; /* refcount increased to prevent dlclose */ 22235529Sdfr 223110804Skan struct link_map linkmap; /* for GDB and dlinfo() */ 22450977Sjdp Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 22550977Sjdp Objlist dagmembers; /* DAG has these members (%) */ 22650977Sjdp dev_t dev; /* Object's filesystem's device */ 22750977Sjdp ino_t ino; /* Object's inode number */ 22885004Sdfr void *priv; /* Platform-dependant */ 22934192Sjdp} Obj_Entry; 23034192Sjdp 23134192Sjdp#define RTLD_MAGIC 0xd550b87a 23234192Sjdp#define RTLD_VERSION 1 23334192Sjdp 234133063Sdfr#define RTLD_STATIC_TLS_EXTRA 64 235133063Sdfr 236153515Skan/* Flags to be passed into symlook_ family of functions. */ 237153515Skan#define SYMLOOK_IN_PLT 0x01 /* Lookup for PLT symbol */ 238153515Skan#define SYMLOOK_DLSYM 0x02 /* Return newes versioned symbol. Used by 239153515Skan dlsym. */ 240153515Skan 24176296Sjdp/* 24276296Sjdp * Symbol cache entry used during relocation to avoid multiple lookups 24376296Sjdp * of the same symbol. 24476296Sjdp */ 24576296Sjdptypedef struct Struct_SymCache { 24676296Sjdp const Elf_Sym *sym; /* Symbol table entry */ 24776296Sjdp const Obj_Entry *obj; /* Shared object which defines it */ 24876296Sjdp} SymCache; 24976296Sjdp 25048871Sjdpextern void _rtld_error(const char *, ...) __printflike(1, 2); 25150609Sjdpextern Obj_Entry *map_object(int, const char *, const struct stat *); 25234192Sjdpextern void *xcalloc(size_t); 25334192Sjdpextern void *xmalloc(size_t); 25434192Sjdpextern char *xstrdup(const char *); 25538816Sdfrextern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 25634192Sjdp 257116563Smdoddextern void dump_relocations (Obj_Entry *); 258116563Smdoddextern void dump_obj_relocations (Obj_Entry *); 259116563Smdoddextern void dump_Elf_Rel (Obj_Entry *, const Elf_Rel *, u_long); 260116563Smdoddextern void dump_Elf_Rela (Obj_Entry *, const Elf_Rela *, u_long); 261116563Smdodd 26238816Sdfr/* 26338816Sdfr * Function declarations. 26438816Sdfr */ 26538816Sdfrunsigned long elf_hash(const char *); 26666056Sjdpconst Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, 267153515Skan const Obj_Entry **, int, SymCache *); 26845501Sjdpvoid init_pltgot(Obj_Entry *); 269116557Smdoddvoid lockdflt_init(void); 27050608Sjdpvoid obj_free(Obj_Entry *); 27150608SjdpObj_Entry *obj_new(void); 27245501Sjdpvoid _rtld_bind_start(void); 273153515Skanconst Elf_Sym *symlook_obj(const char *, unsigned long, const Obj_Entry *, 274153515Skan const Ver_Entry *, int); 275133063Sdfrvoid *tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset); 276133063Sdfrvoid *allocate_tls(Obj_Entry *, void *, size_t, size_t); 277133063Sdfrvoid free_tls(void *, size_t, size_t); 278133063Sdfrvoid *allocate_module_tls(int index); 279133063Sdfrbool allocate_tls_offset(Obj_Entry *obj); 280142645Sdfrvoid free_tls_offset(Obj_Entry *obj); 281153515Skanconst Ver_Entry *fetch_ventry(const Obj_Entry *obj, unsigned long); 28238816Sdfr 283116558Smdodd/* 284116558Smdodd * MD function declarations. 285116558Smdodd */ 286116558Smdoddint do_copy_relocations(Obj_Entry *); 287116558Smdoddint reloc_non_plt(Obj_Entry *, Obj_Entry *); 288116558Smdoddint reloc_plt(Obj_Entry *); 289116558Smdoddint reloc_jmpslots(Obj_Entry *); 290133063Sdfrvoid allocate_initial_tls(Obj_Entry *); 291116558Smdodd 29234192Sjdp#endif /* } */ 293