freebsd-dev/libexec/rtld-elf/rtld.h
Alexander Kabaev 42d206e975 Implement dlinfo() function.
Introdice RTLD_SELF special handle and properly process it within
dlsym() and dlinfo() functions.

The intention is to improve our compatibility with Solaris and
to make a Java port easier.

Partially submitted by:	phantom
2003-02-13 17:47:44 +00:00

205 lines
7.5 KiB
C

/*-
* 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 <machine/elf.h>
#include <sys/types.h>
#include <sys/queue.h>
#include <elf-hints.h>
#include <link.h>
#include <stddef.h>
#include "rtld_machdep.h"
#ifndef STANDARD_LIBRARY_PATH
#define STANDARD_LIBRARY_PATH "/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 (%) */
Elf_Addr init; /* Initialization function to call */
Elf_Addr 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 and dlinfo() */
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 /* } */