/*- * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * $FreeBSD$ */ #ifndef RTLD_H /* { */ #define RTLD_H 1 #include #include #include #include #include #include #include "rtld_machdep.h" #ifndef STANDARD_LIBRARY_PATH #define STANDARD_LIBRARY_PATH "/usr/lib/elf:/usr/lib" #endif #define NEW(type) ((type *) xmalloc(sizeof(type))) #define CNEW(type) ((type *) xcalloc(sizeof(type))) /* We might as well do booleans like C++. */ typedef unsigned char bool; #define false 0 #define true 1 struct stat; struct Struct_Obj_Entry; /* Lists of shared objects */ typedef struct Struct_Objlist_Entry { STAILQ_ENTRY(Struct_Objlist_Entry) link; struct Struct_Obj_Entry *obj; } Objlist_Entry; typedef STAILQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist; /* Types of init and fini functions */ typedef void (*InitFunc)(void); /* Lists of shared object dependencies */ typedef struct Struct_Needed_Entry { struct Struct_Needed_Entry *next; struct Struct_Obj_Entry *obj; unsigned long name; /* Offset of name in string table */ } Needed_Entry; /* Lock object */ typedef struct Struct_LockInfo { void *context; /* Client context for creating locks */ void *thelock; /* The one big lock */ /* Debugging aids. */ volatile int rcount; /* Number of readers holding lock */ volatile int wcount; /* Number of writers holding lock */ /* Methods */ void *(*lock_create)(void *context); void (*rlock_acquire)(void *lock); void (*wlock_acquire)(void *lock); void (*rlock_release)(void *lock); void (*wlock_release)(void *lock); void (*lock_destroy)(void *lock); void (*context_destroy)(void *context); } LockInfo; /* * Shared object descriptor. * * Items marked with "(%)" are dynamically allocated, and must be freed * when the structure is destroyed. * * CAUTION: It appears that the JDK port peeks into these structures. * It looks at "next" and "mapbase" at least. Don't add new members * near the front, until this can be straightened out. */ typedef struct Struct_Obj_Entry { /* * These two items have to be set right for compatibility with the * original ElfKit crt1.o. */ Elf_Word magic; /* Magic number (sanity check) */ Elf_Word version; /* Version number of struct format */ struct Struct_Obj_Entry *next; char *path; /* Pathname of underlying file (%) */ int refcount; int dl_refcount; /* Number of times loaded by dlopen */ /* These items are computed by map_object() or by digest_phdr(). */ caddr_t mapbase; /* Base address of mapped region */ size_t mapsize; /* Size of mapped region in bytes */ size_t textsize; /* Size of text segment in bytes */ Elf_Addr vaddrbase; /* Base address in shared object file */ caddr_t relocbase; /* Relocation constant = mapbase - vaddrbase */ const Elf_Dyn *dynamic; /* Dynamic section */ caddr_t entry; /* Entry point */ const Elf_Phdr *phdr; /* Program header if it is mapped, else NULL */ size_t phsize; /* Size of program header in bytes */ const char *interp; /* Pathname of the interpreter, if any */ /* Items from the dynamic section. */ Elf_Addr *pltgot; /* PLT or GOT, depending on architecture */ const Elf_Rel *rel; /* Relocation entries */ unsigned long relsize; /* Size in bytes of relocation info */ const Elf_Rela *rela; /* Relocation entries with addend */ unsigned long relasize; /* Size in bytes of addend relocation info */ const Elf_Rel *pltrel; /* PLT relocation entries */ unsigned long pltrelsize; /* Size in bytes of PLT relocation info */ const Elf_Rela *pltrela; /* PLT relocation entries with addend */ unsigned long pltrelasize; /* Size in bytes of PLT addend reloc info */ const Elf_Sym *symtab; /* Symbol table */ const char *strtab; /* String table */ unsigned long strsize; /* Size in bytes of string table */ const Elf_Hashelt *buckets; /* Hash table buckets array */ unsigned long nbuckets; /* Number of buckets */ const Elf_Hashelt *chains; /* Hash table chain array */ unsigned long nchains; /* Number of chains */ const char *rpath; /* Search path specified in object */ Needed_Entry *needed; /* Shared objects needed by this one (%) */ InitFunc init; /* Initialization function to call */ InitFunc fini; /* Termination function to call */ bool mainprog; /* True if this is the main program */ bool rtld; /* True if this is the dynamic linker */ bool textrel; /* True if there are relocations to text seg */ bool symbolic; /* True if generated with "-Bsymbolic" */ bool traced; /* Already printed in ldd trace output */ bool jmpslots_done; /* Already have relocated the jump slots */ bool init_done; /* Already have added object to init list */ struct link_map linkmap; /* for GDB */ Objlist dldags; /* Object belongs to these dlopened DAGs (%) */ Objlist dagmembers; /* DAG has these members (%) */ dev_t dev; /* Object's filesystem's device */ ino_t ino; /* Object's inode number */ void *priv; /* Platform-dependant */ } Obj_Entry; #define RTLD_MAGIC 0xd550b87a #define RTLD_VERSION 1 /* * Symbol cache entry used during relocation to avoid multiple lookups * of the same symbol. */ typedef struct Struct_SymCache { const Elf_Sym *sym; /* Symbol table entry */ const Obj_Entry *obj; /* Shared object which defines it */ } SymCache; extern void _rtld_error(const char *, ...) __printflike(1, 2); extern Obj_Entry *map_object(int, const char *, const struct stat *); extern void *xcalloc(size_t); extern void *xmalloc(size_t); extern char *xstrdup(const char *); extern Elf_Addr _GLOBAL_OFFSET_TABLE_[]; /* * Function declarations. */ int do_copy_relocations(Obj_Entry *); unsigned long elf_hash(const char *); const Elf_Sym *find_symdef(unsigned long, const Obj_Entry *, const Obj_Entry **, bool, SymCache *); void init_pltgot(Obj_Entry *); void lockdflt_init(LockInfo *); void obj_free(Obj_Entry *); Obj_Entry *obj_new(void); int reloc_non_plt(Obj_Entry *, Obj_Entry *); int reloc_plt(Obj_Entry *); int reloc_jmpslots(Obj_Entry *); void _rtld_bind_start(void); const Elf_Sym *symlook_obj(const char *, unsigned long, const Obj_Entry *, bool); #endif /* } */