rtld.h revision 142645
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 142645 2005-02-27 12:55:40Z dfr $ 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 9362801Sjdp/* Lock object */ 9462801Sjdptypedef struct Struct_LockInfo { 9562801Sjdp void *context; /* Client context for creating locks */ 9662801Sjdp void *thelock; /* The one big lock */ 9762801Sjdp /* Debugging aids. */ 9862801Sjdp volatile int rcount; /* Number of readers holding lock */ 9962801Sjdp volatile int wcount; /* Number of writers holding lock */ 10062801Sjdp /* Methods */ 10162801Sjdp void *(*lock_create)(void *context); 10262801Sjdp void (*rlock_acquire)(void *lock); 10362801Sjdp void (*wlock_acquire)(void *lock); 10462801Sjdp void (*rlock_release)(void *lock); 10562801Sjdp void (*wlock_release)(void *lock); 10662801Sjdp void (*lock_destroy)(void *lock); 10762801Sjdp void (*context_destroy)(void *context); 10862801Sjdp} LockInfo; 10962801Sjdp 11034192Sjdp/* 11134192Sjdp * Shared object descriptor. 11234192Sjdp * 11334192Sjdp * Items marked with "(%)" are dynamically allocated, and must be freed 11434192Sjdp * when the structure is destroyed. 11550977Sjdp * 11650977Sjdp * CAUTION: It appears that the JDK port peeks into these structures. 11750977Sjdp * It looks at "next" and "mapbase" at least. Don't add new members 11850977Sjdp * near the front, until this can be straightened out. 11934192Sjdp */ 12034192Sjdptypedef struct Struct_Obj_Entry { 12134192Sjdp /* 12234192Sjdp * These two items have to be set right for compatibility with the 12334192Sjdp * original ElfKit crt1.o. 12434192Sjdp */ 12538467Sjb Elf_Word magic; /* Magic number (sanity check) */ 12638467Sjb Elf_Word version; /* Version number of struct format */ 12734192Sjdp 12834192Sjdp struct Struct_Obj_Entry *next; 12934192Sjdp char *path; /* Pathname of underlying file (%) */ 130116511Smdodd char *origin_path; /* Directory path of origin file */ 13134192Sjdp int refcount; 13234192Sjdp int dl_refcount; /* Number of times loaded by dlopen */ 13334192Sjdp 13434192Sjdp /* These items are computed by map_object() or by digest_phdr(). */ 13534192Sjdp caddr_t mapbase; /* Base address of mapped region */ 13634192Sjdp size_t mapsize; /* Size of mapped region in bytes */ 13734192Sjdp size_t textsize; /* Size of text segment in bytes */ 13838467Sjb Elf_Addr vaddrbase; /* Base address in shared object file */ 13934192Sjdp caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 14038467Sjb const Elf_Dyn *dynamic; /* Dynamic section */ 14134192Sjdp caddr_t entry; /* Entry point */ 14238467Sjb const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 14334192Sjdp size_t phsize; /* Size of program header in bytes */ 14450610Sjdp const char *interp; /* Pathname of the interpreter, if any */ 14534192Sjdp 146133063Sdfr /* TLS information */ 147133063Sdfr int tlsindex; /* Index in DTV for this module */ 148133063Sdfr void *tlsinit; /* Base address of TLS init block */ 149133063Sdfr size_t tlsinitsize; /* Size of TLS init block for this module */ 150133063Sdfr size_t tlssize; /* Size of TLS block for this module */ 151133063Sdfr size_t tlsoffset; /* Offset of static TLS block for this module */ 152133063Sdfr size_t tlsalign; /* Alignment of static TLS block */ 153133063Sdfr 15434192Sjdp /* Items from the dynamic section. */ 15545501Sjdp Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ 15638467Sjb const Elf_Rel *rel; /* Relocation entries */ 15734192Sjdp unsigned long relsize; /* Size in bytes of relocation info */ 15838816Sdfr const Elf_Rela *rela; /* Relocation entries with addend */ 15938816Sdfr unsigned long relasize; /* Size in bytes of addend relocation info */ 16038467Sjb const Elf_Rel *pltrel; /* PLT relocation entries */ 16134192Sjdp unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ 16238816Sdfr const Elf_Rela *pltrela; /* PLT relocation entries with addend */ 16338816Sdfr unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ 16438467Sjb const Elf_Sym *symtab; /* Symbol table */ 16534192Sjdp const char *strtab; /* String table */ 16634192Sjdp unsigned long strsize; /* Size in bytes of string table */ 16734192Sjdp 16885004Sdfr const Elf_Hashelt *buckets; /* Hash table buckets array */ 16934192Sjdp unsigned long nbuckets; /* Number of buckets */ 17085004Sdfr const Elf_Hashelt *chains; /* Hash table chain array */ 17134192Sjdp unsigned long nchains; /* Number of chains */ 17234192Sjdp 17334192Sjdp const char *rpath; /* Search path specified in object */ 17434192Sjdp Needed_Entry *needed; /* Shared objects needed by this one (%) */ 17534192Sjdp 17685677Speter Elf_Addr init; /* Initialization function to call */ 17785677Speter Elf_Addr fini; /* Termination function to call */ 17834192Sjdp 17934192Sjdp bool mainprog; /* True if this is the main program */ 18034192Sjdp bool rtld; /* True if this is the dynamic linker */ 18134192Sjdp bool textrel; /* True if there are relocations to text seg */ 18234192Sjdp bool symbolic; /* True if generated with "-Bsymbolic" */ 183116511Smdodd bool bind_now; /* True if all relocations should be made first */ 18438740Sjdp bool traced; /* Already printed in ldd trace output */ 18556780Sjdp bool jmpslots_done; /* Already have relocated the jump slots */ 18663870Sjdp bool init_done; /* Already have added object to init list */ 187133063Sdfr bool tls_done; /* Already allocated offset for static TLS */ 18835529Sdfr 189110804Skan struct link_map linkmap; /* for GDB and dlinfo() */ 19050977Sjdp Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 19150977Sjdp Objlist dagmembers; /* DAG has these members (%) */ 19250977Sjdp dev_t dev; /* Object's filesystem's device */ 19350977Sjdp ino_t ino; /* Object's inode number */ 19485004Sdfr void *priv; /* Platform-dependant */ 19534192Sjdp} Obj_Entry; 19634192Sjdp 19734192Sjdp#define RTLD_MAGIC 0xd550b87a 19834192Sjdp#define RTLD_VERSION 1 19934192Sjdp 200133063Sdfr#define RTLD_STATIC_TLS_EXTRA 64 201133063Sdfr 20276296Sjdp/* 20376296Sjdp * Symbol cache entry used during relocation to avoid multiple lookups 20476296Sjdp * of the same symbol. 20576296Sjdp */ 20676296Sjdptypedef struct Struct_SymCache { 20776296Sjdp const Elf_Sym *sym; /* Symbol table entry */ 20876296Sjdp const Obj_Entry *obj; /* Shared object which defines it */ 20976296Sjdp} SymCache; 21076296Sjdp 21148871Sjdpextern void _rtld_error(const char *, ...) __printflike(1, 2); 21250609Sjdpextern Obj_Entry *map_object(int, const char *, const struct stat *); 21334192Sjdpextern void *xcalloc(size_t); 21434192Sjdpextern void *xmalloc(size_t); 21534192Sjdpextern char *xstrdup(const char *); 21638816Sdfrextern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 21734192Sjdp 218116563Smdoddextern void dump_relocations (Obj_Entry *); 219116563Smdoddextern void dump_obj_relocations (Obj_Entry *); 220116563Smdoddextern void dump_Elf_Rel (Obj_Entry *, const Elf_Rel *, u_long); 221116563Smdoddextern void dump_Elf_Rela (Obj_Entry *, const Elf_Rela *, u_long); 222116563Smdodd 22338816Sdfr/* 22438816Sdfr * Function declarations. 22538816Sdfr */ 22638816Sdfrunsigned long elf_hash(const char *); 22766056Sjdpconst Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, 22876296Sjdp const Obj_Entry **, bool, SymCache *); 22945501Sjdpvoid init_pltgot(Obj_Entry *); 230116557Smdoddvoid lockdflt_init(void); 23150608Sjdpvoid obj_free(Obj_Entry *); 23250608SjdpObj_Entry *obj_new(void); 23345501Sjdpvoid _rtld_bind_start(void); 23438816Sdfrconst Elf_Sym *symlook_obj(const char *, unsigned long, 23538816Sdfr const Obj_Entry *, bool); 236133063Sdfrvoid *tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset); 237133063Sdfrvoid *allocate_tls(Obj_Entry *, void *, size_t, size_t); 238133063Sdfrvoid free_tls(void *, size_t, size_t); 239133063Sdfrvoid *allocate_module_tls(int index); 240133063Sdfrbool allocate_tls_offset(Obj_Entry *obj); 241142645Sdfrvoid free_tls_offset(Obj_Entry *obj); 24238816Sdfr 243116558Smdodd/* 244116558Smdodd * MD function declarations. 245116558Smdodd */ 246116558Smdoddint do_copy_relocations(Obj_Entry *); 247116558Smdoddint reloc_non_plt(Obj_Entry *, Obj_Entry *); 248116558Smdoddint reloc_plt(Obj_Entry *); 249116558Smdoddint reloc_jmpslots(Obj_Entry *); 250133063Sdfrvoid allocate_initial_tls(Obj_Entry *); 251116558Smdodd 25234192Sjdp#endif /* } */ 253