rtld.h revision 50610
134192Sjdp/*- 234192Sjdp * Copyright 1996-1998 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 50610 1999-08-30 01:54:13Z jdp $ 2634192Sjdp */ 2734192Sjdp 2834192Sjdp#ifndef RTLD_H /* { */ 2934192Sjdp#define RTLD_H 1 3034192Sjdp 3134192Sjdp#include <sys/types.h> 3250608Sjdp#include <sys/queue.h> 3334192Sjdp 3435529Sdfr#include <link.h> 3534192Sjdp#include <elf.h> 3634192Sjdp#include <stddef.h> 3734192Sjdp 3845501Sjdp#include "rtld_machdep.h" 3945501Sjdp 4034192Sjdp#ifndef STANDARD_LIBRARY_PATH 4134192Sjdp#define STANDARD_LIBRARY_PATH "/usr/lib/elf:/usr/lib" 4234192Sjdp#endif 4334192Sjdp 4434192Sjdp#define NEW(type) ((type *) xmalloc(sizeof(type))) 4534192Sjdp#define CNEW(type) ((type *) xcalloc(sizeof(type))) 4634192Sjdp 4734192Sjdp/* We might as well do booleans like C++. */ 4834192Sjdptypedef unsigned char bool; 4934192Sjdp#define false 0 5034192Sjdp#define true 1 5134192Sjdp 5250609Sjdpstruct stat; 5334192Sjdpstruct Struct_Obj_Entry; 5434192Sjdp 5550608Sjdptypedef struct Struct_Objlist_Entry { 5650608Sjdp STAILQ_ENTRY(Struct_Objlist_Entry) link; 5750608Sjdp struct Struct_Obj_Entry *obj; 5850608Sjdp} Objlist_Entry; 5950608Sjdp 6050608Sjdptypedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; 6150608Sjdp 6234192Sjdptypedef struct Struct_Needed_Entry { 6334192Sjdp struct Struct_Needed_Entry *next; 6434192Sjdp struct Struct_Obj_Entry *obj; 6534192Sjdp unsigned long name; /* Offset of name in string table */ 6634192Sjdp} Needed_Entry; 6734192Sjdp 6834192Sjdp/* 6934192Sjdp * Shared object descriptor. 7034192Sjdp * 7134192Sjdp * Items marked with "(%)" are dynamically allocated, and must be freed 7234192Sjdp * when the structure is destroyed. 7334192Sjdp */ 7434192Sjdptypedef struct Struct_Obj_Entry { 7534192Sjdp /* 7634192Sjdp * These two items have to be set right for compatibility with the 7734192Sjdp * original ElfKit crt1.o. 7834192Sjdp */ 7938467Sjb Elf_Word magic; /* Magic number (sanity check) */ 8038467Sjb Elf_Word version; /* Version number of struct format */ 8134192Sjdp 8234192Sjdp struct Struct_Obj_Entry *next; 8350608Sjdp Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ 8450608Sjdp Objlist dagmembers; /* DAG has these members (%) */ 8534192Sjdp char *path; /* Pathname of underlying file (%) */ 8650609Sjdp dev_t dev; /* Object's filesystem's device */ 8750609Sjdp ino_t ino; /* Object's inode number */ 8850608Sjdp unsigned long mark; /* Set to "curmark" to avoid repeat visits */ 8934192Sjdp int refcount; 9034192Sjdp int dl_refcount; /* Number of times loaded by dlopen */ 9134192Sjdp 9234192Sjdp /* These items are computed by map_object() or by digest_phdr(). */ 9334192Sjdp caddr_t mapbase; /* Base address of mapped region */ 9434192Sjdp size_t mapsize; /* Size of mapped region in bytes */ 9534192Sjdp size_t textsize; /* Size of text segment in bytes */ 9638467Sjb Elf_Addr vaddrbase; /* Base address in shared object file */ 9734192Sjdp caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ 9838467Sjb const Elf_Dyn *dynamic; /* Dynamic section */ 9934192Sjdp caddr_t entry; /* Entry point */ 10038467Sjb const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ 10134192Sjdp size_t phsize; /* Size of program header in bytes */ 10250610Sjdp const char *interp; /* Pathname of the interpreter, if any */ 10334192Sjdp 10434192Sjdp /* Items from the dynamic section. */ 10545501Sjdp Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ 10638467Sjb const Elf_Rel *rel; /* Relocation entries */ 10734192Sjdp unsigned long relsize; /* Size in bytes of relocation info */ 10838816Sdfr const Elf_Rela *rela; /* Relocation entries with addend */ 10938816Sdfr unsigned long relasize; /* Size in bytes of addend relocation info */ 11038467Sjb const Elf_Rel *pltrel; /* PLT relocation entries */ 11134192Sjdp unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ 11238816Sdfr const Elf_Rela *pltrela; /* PLT relocation entries with addend */ 11338816Sdfr unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ 11438467Sjb const Elf_Sym *symtab; /* Symbol table */ 11534192Sjdp const char *strtab; /* String table */ 11634192Sjdp unsigned long strsize; /* Size in bytes of string table */ 11734192Sjdp 11838816Sdfr const Elf_Addr *buckets; /* Hash table buckets array */ 11934192Sjdp unsigned long nbuckets; /* Number of buckets */ 12038816Sdfr const Elf_Addr *chains; /* Hash table chain array */ 12134192Sjdp unsigned long nchains; /* Number of chains */ 12234192Sjdp 12334192Sjdp const char *rpath; /* Search path specified in object */ 12434192Sjdp Needed_Entry *needed; /* Shared objects needed by this one (%) */ 12534192Sjdp 12634192Sjdp void (*init)(void); /* Initialization function to call */ 12734192Sjdp void (*fini)(void); /* Termination function to call */ 12834192Sjdp 12934192Sjdp bool mainprog; /* True if this is the main program */ 13034192Sjdp bool rtld; /* True if this is the dynamic linker */ 13134192Sjdp bool textrel; /* True if there are relocations to text seg */ 13234192Sjdp bool symbolic; /* True if generated with "-Bsymbolic" */ 13338740Sjdp bool traced; /* Already printed in ldd trace output */ 13435529Sdfr 13535529Sdfr struct link_map linkmap; /* for GDB */ 13634192Sjdp} Obj_Entry; 13734192Sjdp 13834192Sjdp#define RTLD_MAGIC 0xd550b87a 13934192Sjdp#define RTLD_VERSION 1 14034192Sjdp 14148871Sjdpextern void _rtld_error(const char *, ...) __printflike(1, 2); 14250609Sjdpextern Obj_Entry *map_object(int, const char *, const struct stat *); 14334192Sjdpextern void *xcalloc(size_t); 14434192Sjdpextern void *xmalloc(size_t); 14534192Sjdpextern char *xstrdup(const char *); 14638816Sdfrextern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; 14734192Sjdp 14838816Sdfr/* 14938816Sdfr * Function declarations. 15038816Sdfr */ 15138816Sdfrint do_copy_relocations(Obj_Entry *); 15238816Sdfrunsigned long elf_hash(const char *); 15350608Sjdpconst Elf_Sym *find_symdef(unsigned long, Obj_Entry *, const Obj_Entry **, 15450608Sjdp bool); 15545501Sjdpvoid init_pltgot(Obj_Entry *); 15650608Sjdpvoid obj_free(Obj_Entry *); 15750608SjdpObj_Entry *obj_new(void); 15845501Sjdpint reloc_non_plt(Obj_Entry *, Obj_Entry *); 15945501Sjdpint reloc_plt(Obj_Entry *, bool); 16045501Sjdpvoid _rtld_bind_start(void); 16138816Sdfrconst Elf_Sym *symlook_obj(const char *, unsigned long, 16238816Sdfr const Obj_Entry *, bool); 16338816Sdfr 16434192Sjdp#endif /* } */ 165