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/* Data structure for communication from the run-time dynamic linker for
loaded ELF shared objects.
Copyright (C) 1995-1999, 2000, 2001, 2004 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#ifndef _LINK_H
#define _LINK_H 1
#include <features.h>
#include <elf.h>
#include <dlfcn.h>
#include <sys/types.h>
#if defined _LIBC && defined __UCLIBC_HAS_THREADS_NATIVE__
#include <tls.h>
#endif
/* We use this macro to refer to ELF types independent of the native wordsize.
`ElfW(TYPE)' is used in place of `Elf32_TYPE' or `Elf64_TYPE'. */
#define ElfW(type) _ElfW (Elf, __ELF_NATIVE_CLASS, type)
#define _ElfW(e,w,t) _ElfW_1 (e, w, _##t)
#define _ElfW_1(e,w,t) e##w##t
#include <bits/elfclass.h> /* Defines __ELF_NATIVE_CLASS. */
/* Rendezvous structure used by the run-time dynamic linker to communicate
details of shared object loading to the debugger. If the executable's
dynamic section has a DT_DEBUG element, the run-time linker sets that
element's value to the address where this structure can be found. */
struct r_debug
{
int r_version; /* Version number for this protocol. */
struct link_map *r_map; /* Head of the chain of loaded objects. */
/* This is the address of a function internal to the run-time linker,
that will always be called when the linker begins to map in a
library or unmap it, and again when the mapping change is complete.
The debugger can set a breakpoint at this address if it wants to
notice shared object mapping changes. */
ElfW(Addr) r_brk;
enum
{
/* This state value describes the mapping change taking place when
the `r_brk' address is called. */
RT_CONSISTENT, /* Mapping change is complete. */
RT_ADD, /* Beginning to add a new object. */
RT_DELETE /* Beginning to remove an object mapping. */
} r_state;
ElfW(Addr) r_ldbase; /* Base address the linker is loaded at. */
};
/* This is the instance of that structure used by the dynamic linker. */
extern struct r_debug _r_debug;
/* This symbol refers to the "dynamic structure" in the `.dynamic' section
of whatever module refers to `_DYNAMIC'. So, to find its own
`struct r_debug', a program could do:
for (dyn = _DYNAMIC; dyn->d_tag != DT_NULL; ++dyn)
if (dyn->d_tag == DT_DEBUG)
r_debug = (struct r_debug *) dyn->d_un.d_ptr;
*/
extern ElfW(Dyn) _DYNAMIC[];
/* Structure describing a loaded shared object. The `l_next' and `l_prev'
members form a chain of all the shared objects loaded at startup.
These data structures exist in space used by the run-time dynamic linker;
modifying them may have disastrous results. */
struct link_map
{
/* These first few members are part of the protocol with the debugger.
This is the same format used in SVR4. */
ElfW(Addr) l_addr; /* Base address shared object is loaded at. */
char *l_name; /* Absolute file name object was found in. */
ElfW(Dyn) *l_ld; /* Dynamic section of the shared object. */
struct link_map *l_next, *l_prev; /* Chain of loaded objects. */
#ifdef USE_TLS
/* Thread-local storage related info. */
/* Start of the initialization image. */
void *l_tls_initimage;
/* Size of the initialization image. */
size_t l_tls_initimage_size;
/* Size of the TLS block. */
size_t l_tls_blocksize;
/* Alignment requirement of the TLS block. */
size_t l_tls_align;
/* Offset of first byte module alignment. */
size_t l_tls_firstbyte_offset;
# ifndef NO_TLS_OFFSET
# define NO_TLS_OFFSET 0
# endif
/* For objects present at startup time: offset in the static TLS block. */
ptrdiff_t l_tls_offset;
/* Index of the module in the dtv array. */
size_t l_tls_modid;
/* Nonzero if _dl_init_static_tls should be called for this module */
unsigned int l_need_tls_init:1;
#endif
};
#ifdef __USE_GNU
struct dl_phdr_info
{
ElfW(Addr) dlpi_addr;
const char *dlpi_name;
const ElfW(Phdr) *dlpi_phdr;
ElfW(Half) dlpi_phnum;
#if 0
/* Note: the next two members were introduced after the first
version of this structure was available. Check the SIZE
argument passed to the dl_iterate_phdr() callback to determine
whether or not they are provided. */
/* Incremented when a new object may have been added. */
unsigned long long int dlpi_adds;
/* Incremented when an object may have been removed. */
unsigned long long int dlpi_subs;
#endif
};
__BEGIN_DECLS
extern int dl_iterate_phdr (int (*callback) (struct dl_phdr_info *info,
size_t size, void *data),
void *data);
__END_DECLS
#endif
#endif /* link.h */
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