rtld.h revision 228375
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 228375 2011-12-09 20:40:24Z 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> 37225152Skib#include <stdarg.h> 38216695Skib#include <setjmp.h> 3934192Sjdp#include <stddef.h> 4034192Sjdp 41115396Skan#include "rtld_lock.h" 4245501Sjdp#include "rtld_machdep.h" 4345501Sjdp 44127250Speter#ifdef COMPAT_32BIT 45127250Speter#undef STANDARD_LIBRARY_PATH 46127250Speter#undef _PATH_ELF_HINTS 47127250Speter#define _PATH_ELF_HINTS "/var/run/ld-elf32.so.hints" 48127250Speter/* For running 32 bit binaries */ 49127250Speter#define STANDARD_LIBRARY_PATH "/lib32:/usr/lib32" 50127250Speter#define LD_ "LD_32_" 51127250Speter#endif 52127250Speter 5334192Sjdp#ifndef STANDARD_LIBRARY_PATH 54119013Sgordon#define STANDARD_LIBRARY_PATH "/lib:/usr/lib" 5534192Sjdp#endif 56127250Speter#ifndef LD_ 57127250Speter#define LD_ "LD_" 58127250Speter#endif 5934192Sjdp 6034192Sjdp#define NEW(type) ((type *) xmalloc(sizeof(type))) 6134192Sjdp#define CNEW(type) ((type *) xcalloc(sizeof(type))) 6234192Sjdp 6334192Sjdp/* We might as well do booleans like C++. */ 6434192Sjdptypedef unsigned char bool; 6534192Sjdp#define false 0 6634192Sjdp#define true 1 6734192Sjdp 68133063Sdfrextern size_t tls_last_offset; 69133063Sdfrextern size_t tls_last_size; 70133063Sdfrextern size_t tls_static_space; 71133063Sdfrextern int tls_dtv_generation; 72133063Sdfrextern int tls_max_index; 73133063Sdfr 7450609Sjdpstruct stat; 7534192Sjdpstruct Struct_Obj_Entry; 7634192Sjdp 7755687Sjdp/* Lists of shared objects */ 7850608Sjdptypedef struct Struct_Objlist_Entry { 7960938Sjake STAILQ_ENTRY(Struct_Objlist_Entry) link; 8050608Sjdp struct Struct_Obj_Entry *obj; 8150608Sjdp} Objlist_Entry; 8250608Sjdp 8360938Sjaketypedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 8450608Sjdp 8563870Sjdp/* Types of init and fini functions */ 8655687Sjdptypedef void (*InitFunc)(void); 8755687Sjdp 8855687Sjdp/* Lists of shared object dependencies */ 8934192Sjdptypedef struct Struct_Needed_Entry { 9034192Sjdp struct Struct_Needed_Entry *next; 9134192Sjdp struct Struct_Obj_Entry *obj; 9234192Sjdp unsigned long name; /* Offset of name in string table */ 9334192Sjdp} Needed_Entry; 9434192Sjdp 95153515Skantypedef struct Struct_Name_Entry { 96153515Skan STAILQ_ENTRY(Struct_Name_Entry) link; 97153515Skan char name[1]; 98153515Skan} Name_Entry; 99153515Skan 10062801Sjdp/* Lock object */ 10162801Sjdptypedef struct Struct_LockInfo { 10262801Sjdp void *context; /* Client context for creating locks */ 10362801Sjdp void *thelock; /* The one big lock */ 10462801Sjdp /* Debugging aids. */ 10562801Sjdp volatile int rcount; /* Number of readers holding lock */ 10662801Sjdp volatile int wcount; /* Number of writers holding lock */ 10762801Sjdp /* Methods */ 10862801Sjdp void *(*lock_create)(void *context); 10962801Sjdp void (*rlock_acquire)(void *lock); 11062801Sjdp void (*wlock_acquire)(void *lock); 11162801Sjdp void (*rlock_release)(void *lock); 11262801Sjdp void (*wlock_release)(void *lock); 11362801Sjdp void (*lock_destroy)(void *lock); 11462801Sjdp void (*context_destroy)(void *context); 11562801Sjdp} LockInfo; 11662801Sjdp 117153515Skantypedef struct Struct_Ver_Entry { 118153515Skan Elf_Word hash; 119153515Skan unsigned int flags; 120153515Skan const char *name; 121153515Skan const char *file; 122153515Skan} Ver_Entry; 123153515Skan 124153515Skan#define VER_INFO_HIDDEN 0x01 125153515Skan 12634192Sjdp/* 12734192Sjdp * Shared object descriptor. 12834192Sjdp * 12934192Sjdp * Items marked with "(%)" are dynamically allocated, and must be freed 13034192Sjdp * when the structure is destroyed. 13150977Sjdp * 13250977Sjdp * CAUTION: It appears that the JDK port peeks into these structures. 13350977Sjdp * It looks at "next" and "mapbase" at least. Don't add new members 13450977Sjdp * near the front, until this can be straightened out. 13534192Sjdp */ 13634192Sjdptypedef struct Struct_Obj_Entry { 13734192Sjdp /* 13834192Sjdp * These two items have to be set right for compatibility with the 13934192Sjdp * original ElfKit crt1.o. 14034192Sjdp */ 141153504Smarcel Elf_Size magic; /* Magic number (sanity check) */ 142153504Smarcel Elf_Size version; /* Version number of struct format */ 14334192Sjdp 14434192Sjdp struct Struct_Obj_Entry *next; 14534192Sjdp char *path; /* Pathname of underlying file (%) */ 146116511Smdodd char *origin_path; /* Directory path of origin file */ 14734192Sjdp int refcount; 14834192Sjdp int dl_refcount; /* Number of times loaded by dlopen */ 14934192Sjdp 15034192Sjdp /* These items are computed by map_object() or by digest_phdr(). */ 15134192Sjdp caddr_t mapbase; /* Base address of mapped region */ 15234192Sjdp size_t mapsize; /* Size of mapped region in bytes */ 15334192Sjdp size_t textsize; /* Size of text segment in bytes */ 15438467Sjb Elf_Addr vaddrbase; /* Base address in shared object file */ 15534192Sjdp caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 15638467Sjb const Elf_Dyn *dynamic; /* Dynamic section */ 15734192Sjdp caddr_t entry; /* Entry point */ 15838467Sjb const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 15934192Sjdp size_t phsize; /* Size of program header in bytes */ 16050610Sjdp const char *interp; /* Pathname of the interpreter, if any */ 161217153Skib Elf_Word stack_flags; 16234192Sjdp 163133063Sdfr /* TLS information */ 164133063Sdfr int tlsindex; /* Index in DTV for this module */ 165133063Sdfr void *tlsinit; /* Base address of TLS init block */ 166133063Sdfr size_t tlsinitsize; /* Size of TLS init block for this module */ 167133063Sdfr size_t tlssize; /* Size of TLS block for this module */ 168133063Sdfr size_t tlsoffset; /* Offset of static TLS block for this module */ 169133063Sdfr size_t tlsalign; /* Alignment of static TLS block */ 170133063Sdfr 17134192Sjdp /* Items from the dynamic section. */ 17245501Sjdp Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ 17338467Sjb const Elf_Rel *rel; /* Relocation entries */ 17434192Sjdp unsigned long relsize; /* Size in bytes of relocation info */ 17538816Sdfr const Elf_Rela *rela; /* Relocation entries with addend */ 17638816Sdfr unsigned long relasize; /* Size in bytes of addend relocation info */ 17738467Sjb const Elf_Rel *pltrel; /* PLT relocation entries */ 17834192Sjdp unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ 17938816Sdfr const Elf_Rela *pltrela; /* PLT relocation entries with addend */ 18038816Sdfr unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ 18138467Sjb const Elf_Sym *symtab; /* Symbol table */ 18234192Sjdp const char *strtab; /* String table */ 18334192Sjdp unsigned long strsize; /* Size in bytes of string table */ 184177924Simp#ifdef __mips__ 185177924Simp Elf_Word local_gotno; /* Number of local GOT entries */ 186177924Simp Elf_Word symtabno; /* Number of dynamic symbols */ 187177924Simp Elf_Word gotsym; /* First dynamic symbol in GOT */ 188177924Simp#endif 18934192Sjdp 190153515Skan const Elf_Verneed *verneed; /* Required versions. */ 191153515Skan Elf_Word verneednum; /* Number of entries in verneed table */ 192153515Skan const Elf_Verdef *verdef; /* Provided versions. */ 193153515Skan Elf_Word verdefnum; /* Number of entries in verdef table */ 194153515Skan const Elf_Versym *versyms; /* Symbol versions table */ 195153515Skan 19685004Sdfr const Elf_Hashelt *buckets; /* Hash table buckets array */ 19734192Sjdp unsigned long nbuckets; /* Number of buckets */ 19885004Sdfr const Elf_Hashelt *chains; /* Hash table chain array */ 19934192Sjdp unsigned long nchains; /* Number of chains */ 20034192Sjdp 201189959Skib char *rpath; /* Search path specified in object */ 20234192Sjdp Needed_Entry *needed; /* Shared objects needed by this one (%) */ 203216695Skib Needed_Entry *needed_filtees; 204216695Skib Needed_Entry *needed_aux_filtees; 20534192Sjdp 206153515Skan STAILQ_HEAD(, Struct_Name_Entry) names; /* List of names for this object we 207153515Skan know about. */ 208153515Skan Ver_Entry *vertab; /* Versions required /defined by this object */ 209153515Skan int vernum; /* Number of entries in vertab */ 210153515Skan 21185677Speter Elf_Addr init; /* Initialization function to call */ 21285677Speter Elf_Addr fini; /* Termination function to call */ 21334192Sjdp 214168312Skan bool mainprog : 1; /* True if this is the main program */ 215168312Skan bool rtld : 1; /* True if this is the dynamic linker */ 216168312Skan bool textrel : 1; /* True if there are relocations to text seg */ 217168312Skan bool symbolic : 1; /* True if generated with "-Bsymbolic" */ 218168312Skan bool bind_now : 1; /* True if all relocations should be made first */ 219168312Skan bool traced : 1; /* Already printed in ldd trace output */ 220168312Skan bool jmpslots_done : 1; /* Already have relocated the jump slots */ 221168312Skan bool init_done : 1; /* Already have added object to init list */ 222168312Skan bool tls_done : 1; /* Already allocated offset for static TLS */ 223168312Skan bool phdr_alloc : 1; /* Phdr is allocated and needs to be freed. */ 224189959Skib bool z_origin : 1; /* Process rpath and soname tokens */ 225190543Skib bool z_nodelete : 1; /* Do not unload the object and dependencies */ 226199829Skib bool z_noopen : 1; /* Do not load on dlopen */ 227216695Skib bool z_loadfltr : 1; /* Immediately load filtees */ 228194531Skan bool ref_nodel : 1; /* Refcount increased to prevent dlclose */ 229194531Skan bool init_scanned: 1; /* Object is already on init list. */ 230194531Skan bool on_fini_list: 1; /* Object is already on fini list. */ 231214728Skib bool dag_inited : 1; /* Object has its DAG initialized. */ 232216695Skib bool filtees_loaded : 1; /* Filtees loaded */ 23335529Sdfr 234194531Skan struct link_map linkmap; /* For GDB and dlinfo() */ 23550977Sjdp Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 23650977Sjdp Objlist dagmembers; /* DAG has these members (%) */ 23750977Sjdp dev_t dev; /* Object's filesystem's device */ 23850977Sjdp ino_t ino; /* Object's inode number */ 23985004Sdfr void *priv; /* Platform-dependant */ 24034192Sjdp} Obj_Entry; 24134192Sjdp 24234192Sjdp#define RTLD_MAGIC 0xd550b87a 24334192Sjdp#define RTLD_VERSION 1 24434192Sjdp 245192922Sdfr#define RTLD_STATIC_TLS_EXTRA 128 246133063Sdfr 247153515Skan/* Flags to be passed into symlook_ family of functions. */ 248153515Skan#define SYMLOOK_IN_PLT 0x01 /* Lookup for PLT symbol */ 249228375Skib#define SYMLOOK_DLSYM 0x02 /* Return newest versioned symbol. Used by 250153515Skan dlsym. */ 251153515Skan 252199829Skib/* Flags for load_object(). */ 253199877Skib#define RTLD_LO_NOLOAD 0x01 /* dlopen() specified RTLD_NOLOAD. */ 254199877Skib#define RTLD_LO_DLOPEN 0x02 /* Load_object() called from dlopen(). */ 255199877Skib#define RTLD_LO_TRACE 0x04 /* Only tracing. */ 256216695Skib#define RTLD_LO_NODELETE 0x08 /* Loaded object cannot be closed. */ 257216695Skib#define RTLD_LO_FILTEES 0x10 /* Loading filtee. */ 258199829Skib 25976296Sjdp/* 26076296Sjdp * Symbol cache entry used during relocation to avoid multiple lookups 26176296Sjdp * of the same symbol. 26276296Sjdp */ 26376296Sjdptypedef struct Struct_SymCache { 26476296Sjdp const Elf_Sym *sym; /* Symbol table entry */ 26576296Sjdp const Obj_Entry *obj; /* Shared object which defines it */ 26676296Sjdp} SymCache; 26776296Sjdp 268216695Skib/* 269216695Skib * This structure provides a reentrant way to keep a list of objects and 270216695Skib * check which ones have already been processed in some way. 271216695Skib */ 272216695Skibtypedef struct Struct_DoneList { 273216695Skib const Obj_Entry **objs; /* Array of object pointers */ 274216695Skib unsigned int num_alloc; /* Allocated size of the array */ 275216695Skib unsigned int num_used; /* Number of array slots used */ 276216695Skib} DoneList; 277216695Skib 278216695Skibstruct Struct_RtldLockState { 279216695Skib int lockstate; 280218476Skib sigjmp_buf env; 281216695Skib}; 282216695Skib 283216695Skib/* 284216695Skib * The pack of arguments and results for the symbol lookup functions. 285216695Skib */ 286216695Skibtypedef struct Struct_SymLook { 287216695Skib const char *name; 288216695Skib unsigned long hash; 289216695Skib const Ver_Entry *ventry; 290216695Skib int flags; 291216695Skib const Obj_Entry *defobj_out; 292216695Skib const Elf_Sym *sym_out; 293216695Skib struct Struct_RtldLockState *lockstate; 294216695Skib} SymLook; 295216695Skib 29648871Sjdpextern void _rtld_error(const char *, ...) __printflike(1, 2); 29750609Sjdpextern Obj_Entry *map_object(int, const char *, const struct stat *); 29834192Sjdpextern void *xcalloc(size_t); 29934192Sjdpextern void *xmalloc(size_t); 30034192Sjdpextern char *xstrdup(const char *); 30138816Sdfrextern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 302212497Snwhitehornextern Elf_Sym sym_zero; /* For resolving undefined weak refs. */ 30334192Sjdp 304116563Smdoddextern void dump_relocations (Obj_Entry *); 305116563Smdoddextern void dump_obj_relocations (Obj_Entry *); 306116563Smdoddextern void dump_Elf_Rel (Obj_Entry *, const Elf_Rel *, u_long); 307116563Smdoddextern void dump_Elf_Rela (Obj_Entry *, const Elf_Rela *, u_long); 308116563Smdodd 30938816Sdfr/* 31038816Sdfr * Function declarations. 31138816Sdfr */ 31238816Sdfrunsigned long elf_hash(const char *); 31366056Sjdpconst Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, 314216695Skib const Obj_Entry **, int, SymCache *, struct Struct_RtldLockState *); 31545501Sjdpvoid init_pltgot(Obj_Entry *); 316116557Smdoddvoid lockdflt_init(void); 31750608Sjdpvoid obj_free(Obj_Entry *); 31850608SjdpObj_Entry *obj_new(void); 31945501Sjdpvoid _rtld_bind_start(void); 320216695Skibvoid symlook_init(SymLook *, const char *); 321216695Skibint symlook_obj(SymLook *, const Obj_Entry *); 322133063Sdfrvoid *tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset); 323133063Sdfrvoid *allocate_tls(Obj_Entry *, void *, size_t, size_t); 324133063Sdfrvoid free_tls(void *, size_t, size_t); 325133063Sdfrvoid *allocate_module_tls(int index); 326133063Sdfrbool allocate_tls_offset(Obj_Entry *obj); 327142645Sdfrvoid free_tls_offset(Obj_Entry *obj); 328153515Skanconst Ver_Entry *fetch_ventry(const Obj_Entry *obj, unsigned long); 32938816Sdfr 330116558Smdodd/* 331116558Smdodd * MD function declarations. 332116558Smdodd */ 333116558Smdoddint do_copy_relocations(Obj_Entry *); 334216695Skibint reloc_non_plt(Obj_Entry *, Obj_Entry *, struct Struct_RtldLockState *); 335116558Smdoddint reloc_plt(Obj_Entry *); 336216695Skibint reloc_jmpslots(Obj_Entry *, struct Struct_RtldLockState *); 337133063Sdfrvoid allocate_initial_tls(Obj_Entry *); 338116558Smdodd 33934192Sjdp#endif /* } */ 340