rtld.h revision 216695
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 216695 2010-12-25 08:51:20Z 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> 37216695Skib#include <setjmp.h> 3834192Sjdp#include <stddef.h> 3934192Sjdp 40115396Skan#include "rtld_lock.h" 4145501Sjdp#include "rtld_machdep.h" 4245501Sjdp 43127250Speter#ifdef COMPAT_32BIT 44127250Speter#undef STANDARD_LIBRARY_PATH 45127250Speter#undef _PATH_ELF_HINTS 46127250Speter#define _PATH_ELF_HINTS "/var/run/ld-elf32.so.hints" 47127250Speter/* For running 32 bit binaries */ 48127250Speter#define STANDARD_LIBRARY_PATH "/lib32:/usr/lib32" 49127250Speter#define LD_ "LD_32_" 50127250Speter#endif 51127250Speter 5234192Sjdp#ifndef STANDARD_LIBRARY_PATH 53119013Sgordon#define STANDARD_LIBRARY_PATH "/lib:/usr/lib" 5434192Sjdp#endif 55127250Speter#ifndef LD_ 56127250Speter#define LD_ "LD_" 57127250Speter#endif 5834192Sjdp 5934192Sjdp#define NEW(type) ((type *) xmalloc(sizeof(type))) 6034192Sjdp#define CNEW(type) ((type *) xcalloc(sizeof(type))) 6134192Sjdp 6234192Sjdp/* We might as well do booleans like C++. */ 6334192Sjdptypedef unsigned char bool; 6434192Sjdp#define false 0 6534192Sjdp#define true 1 6634192Sjdp 67133063Sdfrextern size_t tls_last_offset; 68133063Sdfrextern size_t tls_last_size; 69133063Sdfrextern size_t tls_static_space; 70133063Sdfrextern int tls_dtv_generation; 71133063Sdfrextern int tls_max_index; 72133063Sdfr 7350609Sjdpstruct stat; 7434192Sjdpstruct Struct_Obj_Entry; 7534192Sjdp 7655687Sjdp/* Lists of shared objects */ 7750608Sjdptypedef struct Struct_Objlist_Entry { 7860938Sjake STAILQ_ENTRY(Struct_Objlist_Entry) link; 7950608Sjdp struct Struct_Obj_Entry *obj; 8050608Sjdp} Objlist_Entry; 8150608Sjdp 8260938Sjaketypedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 8350608Sjdp 8463870Sjdp/* Types of init and fini functions */ 8555687Sjdptypedef void (*InitFunc)(void); 8655687Sjdp 8755687Sjdp/* Lists of shared object dependencies */ 8834192Sjdptypedef struct Struct_Needed_Entry { 8934192Sjdp struct Struct_Needed_Entry *next; 9034192Sjdp struct Struct_Obj_Entry *obj; 9134192Sjdp unsigned long name; /* Offset of name in string table */ 9234192Sjdp} Needed_Entry; 9334192Sjdp 94153515Skantypedef struct Struct_Name_Entry { 95153515Skan STAILQ_ENTRY(Struct_Name_Entry) link; 96153515Skan char name[1]; 97153515Skan} Name_Entry; 98153515Skan 9962801Sjdp/* Lock object */ 10062801Sjdptypedef struct Struct_LockInfo { 10162801Sjdp void *context; /* Client context for creating locks */ 10262801Sjdp void *thelock; /* The one big lock */ 10362801Sjdp /* Debugging aids. */ 10462801Sjdp volatile int rcount; /* Number of readers holding lock */ 10562801Sjdp volatile int wcount; /* Number of writers holding lock */ 10662801Sjdp /* Methods */ 10762801Sjdp void *(*lock_create)(void *context); 10862801Sjdp void (*rlock_acquire)(void *lock); 10962801Sjdp void (*wlock_acquire)(void *lock); 11062801Sjdp void (*rlock_release)(void *lock); 11162801Sjdp void (*wlock_release)(void *lock); 11262801Sjdp void (*lock_destroy)(void *lock); 11362801Sjdp void (*context_destroy)(void *context); 11462801Sjdp} LockInfo; 11562801Sjdp 116153515Skantypedef struct Struct_Ver_Entry { 117153515Skan Elf_Word hash; 118153515Skan unsigned int flags; 119153515Skan const char *name; 120153515Skan const char *file; 121153515Skan} Ver_Entry; 122153515Skan 123153515Skan#define VER_INFO_HIDDEN 0x01 124153515Skan 12534192Sjdp/* 12634192Sjdp * Shared object descriptor. 12734192Sjdp * 12834192Sjdp * Items marked with "(%)" are dynamically allocated, and must be freed 12934192Sjdp * when the structure is destroyed. 13050977Sjdp * 13150977Sjdp * CAUTION: It appears that the JDK port peeks into these structures. 13250977Sjdp * It looks at "next" and "mapbase" at least. Don't add new members 13350977Sjdp * near the front, until this can be straightened out. 13434192Sjdp */ 13534192Sjdptypedef struct Struct_Obj_Entry { 13634192Sjdp /* 13734192Sjdp * These two items have to be set right for compatibility with the 13834192Sjdp * original ElfKit crt1.o. 13934192Sjdp */ 140153504Smarcel Elf_Size magic; /* Magic number (sanity check) */ 141153504Smarcel Elf_Size version; /* Version number of struct format */ 14234192Sjdp 14334192Sjdp struct Struct_Obj_Entry *next; 14434192Sjdp char *path; /* Pathname of underlying file (%) */ 145116511Smdodd char *origin_path; /* Directory path of origin file */ 14634192Sjdp int refcount; 14734192Sjdp int dl_refcount; /* Number of times loaded by dlopen */ 14834192Sjdp 14934192Sjdp /* These items are computed by map_object() or by digest_phdr(). */ 15034192Sjdp caddr_t mapbase; /* Base address of mapped region */ 15134192Sjdp size_t mapsize; /* Size of mapped region in bytes */ 15234192Sjdp size_t textsize; /* Size of text segment in bytes */ 15338467Sjb Elf_Addr vaddrbase; /* Base address in shared object file */ 15434192Sjdp caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 15538467Sjb const Elf_Dyn *dynamic; /* Dynamic section */ 15634192Sjdp caddr_t entry; /* Entry point */ 15738467Sjb const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 15834192Sjdp size_t phsize; /* Size of program header in bytes */ 15950610Sjdp const char *interp; /* Pathname of the interpreter, if any */ 16034192Sjdp 161133063Sdfr /* TLS information */ 162133063Sdfr int tlsindex; /* Index in DTV for this module */ 163133063Sdfr void *tlsinit; /* Base address of TLS init block */ 164133063Sdfr size_t tlsinitsize; /* Size of TLS init block for this module */ 165133063Sdfr size_t tlssize; /* Size of TLS block for this module */ 166133063Sdfr size_t tlsoffset; /* Offset of static TLS block for this module */ 167133063Sdfr size_t tlsalign; /* Alignment of static TLS block */ 168133063Sdfr 16934192Sjdp /* Items from the dynamic section. */ 17045501Sjdp Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ 17138467Sjb const Elf_Rel *rel; /* Relocation entries */ 17234192Sjdp unsigned long relsize; /* Size in bytes of relocation info */ 17338816Sdfr const Elf_Rela *rela; /* Relocation entries with addend */ 17438816Sdfr unsigned long relasize; /* Size in bytes of addend relocation info */ 17538467Sjb const Elf_Rel *pltrel; /* PLT relocation entries */ 17634192Sjdp unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ 17738816Sdfr const Elf_Rela *pltrela; /* PLT relocation entries with addend */ 17838816Sdfr unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ 17938467Sjb const Elf_Sym *symtab; /* Symbol table */ 18034192Sjdp const char *strtab; /* String table */ 18134192Sjdp unsigned long strsize; /* Size in bytes of string table */ 182177924Simp#ifdef __mips__ 183177924Simp Elf_Word local_gotno; /* Number of local GOT entries */ 184177924Simp Elf_Word symtabno; /* Number of dynamic symbols */ 185177924Simp Elf_Word gotsym; /* First dynamic symbol in GOT */ 186177924Simp#endif 18734192Sjdp 188153515Skan const Elf_Verneed *verneed; /* Required versions. */ 189153515Skan Elf_Word verneednum; /* Number of entries in verneed table */ 190153515Skan const Elf_Verdef *verdef; /* Provided versions. */ 191153515Skan Elf_Word verdefnum; /* Number of entries in verdef table */ 192153515Skan const Elf_Versym *versyms; /* Symbol versions table */ 193153515Skan 19485004Sdfr const Elf_Hashelt *buckets; /* Hash table buckets array */ 19534192Sjdp unsigned long nbuckets; /* Number of buckets */ 19685004Sdfr const Elf_Hashelt *chains; /* Hash table chain array */ 19734192Sjdp unsigned long nchains; /* Number of chains */ 19834192Sjdp 199189959Skib char *rpath; /* Search path specified in object */ 20034192Sjdp Needed_Entry *needed; /* Shared objects needed by this one (%) */ 201216695Skib Needed_Entry *needed_filtees; 202216695Skib Needed_Entry *needed_aux_filtees; 20334192Sjdp 204153515Skan STAILQ_HEAD(, Struct_Name_Entry) names; /* List of names for this object we 205153515Skan know about. */ 206153515Skan Ver_Entry *vertab; /* Versions required /defined by this object */ 207153515Skan int vernum; /* Number of entries in vertab */ 208153515Skan 20985677Speter Elf_Addr init; /* Initialization function to call */ 21085677Speter Elf_Addr fini; /* Termination function to call */ 21134192Sjdp 212168312Skan bool mainprog : 1; /* True if this is the main program */ 213168312Skan bool rtld : 1; /* True if this is the dynamic linker */ 214168312Skan bool textrel : 1; /* True if there are relocations to text seg */ 215168312Skan bool symbolic : 1; /* True if generated with "-Bsymbolic" */ 216168312Skan bool bind_now : 1; /* True if all relocations should be made first */ 217168312Skan bool traced : 1; /* Already printed in ldd trace output */ 218168312Skan bool jmpslots_done : 1; /* Already have relocated the jump slots */ 219168312Skan bool init_done : 1; /* Already have added object to init list */ 220168312Skan bool tls_done : 1; /* Already allocated offset for static TLS */ 221168312Skan bool phdr_alloc : 1; /* Phdr is allocated and needs to be freed. */ 222189959Skib bool z_origin : 1; /* Process rpath and soname tokens */ 223190543Skib bool z_nodelete : 1; /* Do not unload the object and dependencies */ 224199829Skib bool z_noopen : 1; /* Do not load on dlopen */ 225216695Skib bool z_loadfltr : 1; /* Immediately load filtees */ 226194531Skan bool ref_nodel : 1; /* Refcount increased to prevent dlclose */ 227194531Skan bool init_scanned: 1; /* Object is already on init list. */ 228194531Skan bool on_fini_list: 1; /* Object is already on fini list. */ 229214728Skib bool dag_inited : 1; /* Object has its DAG initialized. */ 230216695Skib bool filtees_loaded : 1; /* Filtees loaded */ 23135529Sdfr 232194531Skan struct link_map linkmap; /* For GDB and dlinfo() */ 23350977Sjdp Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 23450977Sjdp Objlist dagmembers; /* DAG has these members (%) */ 23550977Sjdp dev_t dev; /* Object's filesystem's device */ 23650977Sjdp ino_t ino; /* Object's inode number */ 23785004Sdfr void *priv; /* Platform-dependant */ 23834192Sjdp} Obj_Entry; 23934192Sjdp 24034192Sjdp#define RTLD_MAGIC 0xd550b87a 24134192Sjdp#define RTLD_VERSION 1 24234192Sjdp 243192922Sdfr#define RTLD_STATIC_TLS_EXTRA 128 244133063Sdfr 245153515Skan/* Flags to be passed into symlook_ family of functions. */ 246153515Skan#define SYMLOOK_IN_PLT 0x01 /* Lookup for PLT symbol */ 247153515Skan#define SYMLOOK_DLSYM 0x02 /* Return newes versioned symbol. Used by 248153515Skan dlsym. */ 249153515Skan 250199829Skib/* Flags for load_object(). */ 251199877Skib#define RTLD_LO_NOLOAD 0x01 /* dlopen() specified RTLD_NOLOAD. */ 252199877Skib#define RTLD_LO_DLOPEN 0x02 /* Load_object() called from dlopen(). */ 253199877Skib#define RTLD_LO_TRACE 0x04 /* Only tracing. */ 254216695Skib#define RTLD_LO_NODELETE 0x08 /* Loaded object cannot be closed. */ 255216695Skib#define RTLD_LO_FILTEES 0x10 /* Loading filtee. */ 256199829Skib 25776296Sjdp/* 25876296Sjdp * Symbol cache entry used during relocation to avoid multiple lookups 25976296Sjdp * of the same symbol. 26076296Sjdp */ 26176296Sjdptypedef struct Struct_SymCache { 26276296Sjdp const Elf_Sym *sym; /* Symbol table entry */ 26376296Sjdp const Obj_Entry *obj; /* Shared object which defines it */ 26476296Sjdp} SymCache; 26576296Sjdp 266216695Skib/* 267216695Skib * This structure provides a reentrant way to keep a list of objects and 268216695Skib * check which ones have already been processed in some way. 269216695Skib */ 270216695Skibtypedef struct Struct_DoneList { 271216695Skib const Obj_Entry **objs; /* Array of object pointers */ 272216695Skib unsigned int num_alloc; /* Allocated size of the array */ 273216695Skib unsigned int num_used; /* Number of array slots used */ 274216695Skib} DoneList; 275216695Skib 276216695Skibstruct Struct_RtldLockState { 277216695Skib int lockstate; 278216695Skib jmp_buf env; 279216695Skib}; 280216695Skib 281216695Skib/* 282216695Skib * The pack of arguments and results for the symbol lookup functions. 283216695Skib */ 284216695Skibtypedef struct Struct_SymLook { 285216695Skib const char *name; 286216695Skib unsigned long hash; 287216695Skib const Ver_Entry *ventry; 288216695Skib int flags; 289216695Skib const Obj_Entry *defobj_out; 290216695Skib const Elf_Sym *sym_out; 291216695Skib struct Struct_RtldLockState *lockstate; 292216695Skib} SymLook; 293216695Skib 29448871Sjdpextern void _rtld_error(const char *, ...) __printflike(1, 2); 29550609Sjdpextern Obj_Entry *map_object(int, const char *, const struct stat *); 29634192Sjdpextern void *xcalloc(size_t); 29734192Sjdpextern void *xmalloc(size_t); 29834192Sjdpextern char *xstrdup(const char *); 29938816Sdfrextern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 300212497Snwhitehornextern Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 30134192Sjdp 302116563Smdoddextern void dump_relocations (Obj_Entry *); 303116563Smdoddextern void dump_obj_relocations (Obj_Entry *); 304116563Smdoddextern void dump_Elf_Rel (Obj_Entry *, const Elf_Rel *, u_long); 305116563Smdoddextern void dump_Elf_Rela (Obj_Entry *, const Elf_Rela *, u_long); 306116563Smdodd 30738816Sdfr/* 30838816Sdfr * Function declarations. 30938816Sdfr */ 31038816Sdfrunsigned long elf_hash(const char *); 31166056Sjdpconst Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, 312216695Skib const Obj_Entry **, int, SymCache *, struct Struct_RtldLockState *); 31345501Sjdpvoid init_pltgot(Obj_Entry *); 314116557Smdoddvoid lockdflt_init(void); 31550608Sjdpvoid obj_free(Obj_Entry *); 31650608SjdpObj_Entry *obj_new(void); 31745501Sjdpvoid _rtld_bind_start(void); 318216695Skibvoid symlook_init(SymLook *, const char *); 319216695Skibint symlook_obj(SymLook *, const Obj_Entry *); 320133063Sdfrvoid *tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset); 321133063Sdfrvoid *allocate_tls(Obj_Entry *, void *, size_t, size_t); 322133063Sdfrvoid free_tls(void *, size_t, size_t); 323133063Sdfrvoid *allocate_module_tls(int index); 324133063Sdfrbool allocate_tls_offset(Obj_Entry *obj); 325142645Sdfrvoid free_tls_offset(Obj_Entry *obj); 326153515Skanconst Ver_Entry *fetch_ventry(const Obj_Entry *obj, unsigned long); 32738816Sdfr 328116558Smdodd/* 329116558Smdodd * MD function declarations. 330116558Smdodd */ 331116558Smdoddint do_copy_relocations(Obj_Entry *); 332216695Skibint reloc_non_plt(Obj_Entry *, Obj_Entry *, struct Struct_RtldLockState *); 333116558Smdoddint reloc_plt(Obj_Entry *); 334216695Skibint reloc_jmpslots(Obj_Entry *, struct Struct_RtldLockState *); 335133063Sdfrvoid allocate_initial_tls(Obj_Entry *); 336116558Smdodd 33734192Sjdp#endif /* } */ 338