NetBSD-5.0.2/libexec/ld.elf_so/rtld.h
/* $NetBSD: rtld.h,v 1.79.8.3 2010/01/23 20:37:01 bouyer Exp $ */
/*
* Copyright 1996 John D. Polstra.
* Copyright 1996 Matt Thomas <matt@3am-software.com>
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by John Polstra.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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.
*/
#ifndef RTLD_H
#define RTLD_H
#include <dlfcn.h>
#include <stdbool.h>
#include <stddef.h>
#include <sys/param.h>
#include <sys/types.h>
#include <sys/queue.h>
#include <sys/exec_elf.h>
#include "rtldenv.h"
#include "link.h"
#if defined(_RTLD_SOURCE)
#ifndef RTLD_DEFAULT_LIBRARY_PATH
#define RTLD_DEFAULT_LIBRARY_PATH "/usr/lib"
#endif
#define _PATH_LD_HINTS "/etc/ld.so.conf"
extern int _rtld_pagesz;
#define round_down(x) ((x) & ~(_rtld_pagesz - 1))
#define round_up(x) round_down((x) + _rtld_pagesz - 1)
#define NEW(type) ((type *) xmalloc(sizeof(type)))
#define CNEW(type) ((type *) xcalloc(sizeof(type)))
#endif /* _RTLD_SOURCE */
/*
* C++ has mandated the use of the following keywords for its new boolean
* type. We might as well follow their lead.
*/
struct Struct_Obj_Entry;
typedef struct Struct_Objlist_Entry {
SIMPLEQ_ENTRY(Struct_Objlist_Entry) link;
struct Struct_Obj_Entry *obj;
} Objlist_Entry;
typedef SIMPLEQ_HEAD(Struct_Objlist, Struct_Objlist_Entry) Objlist;
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;
typedef struct _rtld_search_path_t {
struct _rtld_search_path_t *sp_next;
const char *sp_path;
size_t sp_pathlen;
} Search_Path;
#define RTLD_MAX_ENTRY 10
#define RTLD_MAX_LIBRARY 4
#define RTLD_MAX_CTL 2
typedef struct _rtld_library_xform_t {
struct _rtld_library_xform_t *next;
char *name;
const char *ctlname;
struct {
char *value;
char *library[RTLD_MAX_LIBRARY];
} entry[RTLD_MAX_ENTRY];
} Library_Xform;
/*
* Shared object descriptor.
*
* Items marked with "(%)" are dynamically allocated, and must be freed
* when the structure is destroyed.
*/
#define RTLD_MAGIC 0xd550b87a
#define RTLD_VERSION 1
#define RTLD_MAIN 0x800
typedef struct Struct_Obj_Entry {
Elf32_Word magic; /* Magic number (sanity check) */
Elf32_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; /* Reloc const = mapbase - *vaddrbase */
Elf_Dyn *dynamic; /* Dynamic section */
caddr_t entry; /* Entry point */
const Elf_Phdr *__junk001;
size_t pathlen; /* Pathname length */
/* Items from the dynamic section. */
Elf_Addr *pltgot; /* PLTGOT table */
const Elf_Rel *rel; /* Relocation entries */
const Elf_Rel *rellim; /* Limit of Relocation entries */
const Elf_Rela *rela; /* Relocation entries */
const Elf_Rela *relalim; /* Limit of Relocation entries */
const Elf_Rel *pltrel; /* PLT relocation entries */
const Elf_Rel *pltrellim; /* Limit of PLT relocation entries */
const Elf_Rela *pltrela; /* PLT relocation entries */
const Elf_Rela *pltrelalim; /* Limit of PLT relocation entries */
const Elf_Sym *symtab; /* Symbol table */
const char *strtab; /* String table */
unsigned long strsize; /* Size in bytes of string table */
#ifdef __mips__
Elf_Word local_gotno; /* Number of local GOT entries */
Elf_Word symtabno; /* Number of dynamic symbols */
Elf_Word gotsym; /* First dynamic symbol in GOT */
#endif
const Elf_Word *buckets; /* Hash table buckets array */
unsigned long nbuckets; /* Number of buckets */
const Elf_Word *chains; /* Hash table chain array */
unsigned long nchains; /* Number of chains */
Search_Path *rpaths; /* Search path specified in object */
Needed_Entry *needed; /* Shared objects needed by this (%) */
void (*init)(void); /* Initialization function to call */
void (*fini)(void); /* Termination function to call */
/* Entry points for dlopen() and friends. */
void *(*dlopen)(const char *, int);
void *(*dlsym)(void *, const char *);
char *(*dlerror)(void);
int (*dlclose)(void *);
int (*dladdr)(const void *, Dl_info *);
u_int32_t mainprog:1, /* True if this is the main program */
rtld:1, /* True if this is the dynamic linker */
textrel:1, /* True if there are relocations to
* text seg */
symbolic:1, /* True if generated with
* "-Bsymbolic" */
printed:1, /* True if ldd has printed it */
isdynamic:1, /* True if this is a pure PIC object */
mainref:1, /* True if on _rtld_list_main */
globalref:1, /* True if on _rtld_list_global */
init_done:1, /* True if .init has been added */
init_called:1, /* True if .init function has been
* called */
fini_called:1, /* True if .fini function has been
* called */
initfirst:1; /* True if object's .init/.fini take
* priority over others */
struct link_map linkmap; /* for GDB */
/* These items are computed by map_object() or by digest_phdr(). */
const char *interp; /* Pathname of the interpreter, if any */
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 *ehdr;
} Obj_Entry;
#if defined(_RTLD_SOURCE)
extern struct r_debug _rtld_debug;
extern Search_Path *_rtld_default_paths;
extern Obj_Entry *_rtld_objlist;
extern Obj_Entry **_rtld_objtail;
extern Obj_Entry *_rtld_objmain;
extern Obj_Entry _rtld_objself;
extern Search_Path *_rtld_paths;
extern Library_Xform *_rtld_xforms;
extern bool _rtld_trust;
extern Objlist _rtld_list_global;
extern Objlist _rtld_list_main;
extern Elf_Sym _rtld_sym_zero;
/* rtld.c */
/*
* We export these symbols using _rtld_symbol_lookup and is_exported.
*/
char *dlerror(void);
void *dlopen(const char *, int);
void *dlsym(void *, const char *);
int dlclose(void *);
int dladdr(const void *, Dl_info *);
void _rtld_error(const char *, ...)
__attribute__((__format__(__printf__,1,2)));
void _rtld_die(void) __attribute__((__noreturn__));
void *_rtld_objmain_sym(const char *);
void _rtld_debug_state(void);
void _rtld_linkmap_add(Obj_Entry *);
void _rtld_linkmap_delete(Obj_Entry *);
void _rtld_objlist_push_head(Objlist *, Obj_Entry *);
void _rtld_objlist_push_tail(Objlist *, Obj_Entry *);
Objlist_Entry *_rtld_objlist_find(Objlist *, const Obj_Entry *);
/* expand.c */
size_t _rtld_expand_path(char *, size_t, const char *, const char *,\
const char *);
/* headers.c */
void _rtld_digest_dynamic(const char *, Obj_Entry *);
Obj_Entry *_rtld_digest_phdr(const Elf_Phdr *, int, caddr_t);
/* load.c */
Obj_Entry *_rtld_load_object(const char *, int);
int _rtld_load_needed_objects(Obj_Entry *, int);
int _rtld_preload(const char *);
/* path.c */
void _rtld_add_paths(const char *, Search_Path **, const char *);
void _rtld_process_hints(const char *, Search_Path **, Library_Xform **,
const char *);
int _rtld_sysctl(const char *, void *, size_t *);
/* reloc.c */
int _rtld_do_copy_relocations(const Obj_Entry *);
int _rtld_relocate_objects(Obj_Entry *, bool);
int _rtld_relocate_nonplt_objects(const Obj_Entry *);
int _rtld_relocate_plt_lazy(const Obj_Entry *);
int _rtld_relocate_plt_objects(const Obj_Entry *);
void _rtld_setup_pltgot(const Obj_Entry *);
/* search.c */
Obj_Entry *_rtld_load_library(const char *, const Obj_Entry *, int);
/* symbol.c */
unsigned long _rtld_elf_hash(const char *);
const Elf_Sym *_rtld_symlook_obj(const char *, unsigned long,
const Obj_Entry *, bool);
const Elf_Sym *_rtld_find_symdef(unsigned long, const Obj_Entry *,
const Obj_Entry **, bool);
const Elf_Sym *_rtld_symlook_list(const char *, unsigned long,
const Objlist *, const Obj_Entry **, bool);
const Elf_Sym *_rtld_symlook_default(const char *, unsigned long,
const Obj_Entry *, const Obj_Entry **, bool);
const Elf_Sym *_rtld_symlook_needed(const char *, unsigned long,
const Needed_Entry *, const Obj_Entry **, bool);
/* map_object.c */
Obj_Entry *_rtld_map_object(const char *, int, const struct stat *);
void _rtld_obj_free(Obj_Entry *);
Obj_Entry *_rtld_obj_new(void);
/* function descriptors */
#ifdef __HAVE_FUNCTION_DESCRIPTORS
Elf_Addr _rtld_function_descriptor_alloc(const Obj_Entry *,
const Elf_Sym *, Elf_Addr);
const void *_rtld_function_descriptor_function(const void *);
#endif /* __HAVE_FUNCTION_DESCRIPTORS */
#endif /* _RTLD_SOURCE */
#endif /* RTLD_H */