mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-05 21:00:05 +00:00
bf8b3e74bf
* elf/elf.h: Add various DF_1_*, DTF_1_*, and DF_P1_* entries. * elf/dl-close.c (_dl_close): Don't close an object if it is marked with nodelete. * elf/dl-open.c (dl_open_worker): Pass RTLD_NOLOAD as new parameter to _dl_map_object. Return immediately if no object loaded. Set DF_1_NODELETE bit in l_flags_1 if RTLD_NODELETE was passed. * elf/dynamic-link.h (elf_get_dynamic_info): Copy DT_FLAGS_1 entry if it exists into l_flags_1 word. * elf/dl-load.c (_dl_map_object_from_fd): Take no parameter and use it to determine whether loading is wanted or not. (_dl_map_object): Likewise. Call _dl_map_object_from_fd with new parameter. * sysdeps/generic/ldsodefs.h: Update prototype. * elf/dl-deps.c: Add new parameter to _dl_map_object calls. * elf/rtld.c: Likewise. * elf/Makefile (tests): Add noload. Add rules to generate noload. * elf/noload.c: New file. * include/link.h (struct link_map): Add l_feature_1 and l_flags_1. * sysdeps/generic/bits/dlfcn.h: Define RTLD_NOLOAD and RTLD_NODELETE. * sysdeps/mips/bits/dlfcn.h: Likewise.
224 lines
8.3 KiB
C
224 lines
8.3 KiB
C
/* Data structure for communication from the run-time dynamic linker for
|
|
loaded ELF shared objects.
|
|
Copyright (C) 1995-1999, 2000 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 Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. 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>
|
|
|
|
/* 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[];
|
|
|
|
|
|
/* Some internal data structures of the dynamic linker used in the
|
|
linker map. We only provide forward declarations. */
|
|
struct libname_list;
|
|
struct r_found_version;
|
|
struct r_search_path_elem;
|
|
|
|
/* Forward declaration. */
|
|
struct link_map;
|
|
|
|
/* Structure to describe a single list of scope elements. The lookup
|
|
functions get passed an array of pointers to such structures. */
|
|
struct r_scope_elem
|
|
{
|
|
/* Array of maps for the scope. */
|
|
struct link_map **r_list;
|
|
/* Number of entries in the scope. */
|
|
unsigned int r_nlist;
|
|
|
|
/* Array of maps which also includes duplicates. */
|
|
struct link_map **r_duplist;
|
|
/* Number of elements in this list. */
|
|
unsigned int r_nduplist;
|
|
};
|
|
|
|
|
|
/* 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.
|
|
|
|
This data structure might change in future, if necessary. User-level
|
|
programs must avoid defining objects of this type. */
|
|
|
|
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. */
|
|
|
|
/* All following members are internal to the dynamic linker.
|
|
They may change without notice. */
|
|
|
|
struct libname_list *l_libname;
|
|
/* Indexed pointers to dynamic section.
|
|
[0,DT_NUM) are indexed by the processor-independent tags.
|
|
[DT_NUM,DT_NUM+DT_THISPROCNUM) are indexed by the tag minus DT_LOPROC.
|
|
[DT_NUM+DT_THISPROCNUM,DT_NUM+DT_THISPROCNUM+DT_EXTRANUM) are indexed
|
|
by DT_EXTRATAGIDX(tagvalue) and
|
|
[DT_NUM+DT_THISPROCNUM+DT_VERSIONTAGNUM,
|
|
DT_NUM+DT_THISPROCNUM+DT_VERSIONTAGNUM+DT_EXTRANUM)
|
|
are indexed by DT_EXTRATAGIDX(tagvalue) (see <elf.h>). */
|
|
|
|
ElfW(Dyn) *l_info[DT_NUM + DT_THISPROCNUM + DT_VERSIONTAGNUM
|
|
+ DT_EXTRANUM];
|
|
const ElfW(Phdr) *l_phdr; /* Pointer to program header table in core. */
|
|
ElfW(Addr) l_entry; /* Entry point location. */
|
|
ElfW(Half) l_phnum; /* Number of program header entries. */
|
|
ElfW(Half) l_ldnum; /* Number of dynamic segment entries. */
|
|
|
|
/* Array of DT_NEEDED dependencies and their dependencies, in
|
|
dependency order for symbol lookup (with and without
|
|
duplicates). There is no entry before the dependencies have
|
|
been loaded. */
|
|
struct r_scope_elem l_searchlist;
|
|
|
|
/* We need a special searchlist to process objects marked with
|
|
DT_SYMBOLIC. */
|
|
struct r_scope_elem l_symbolic_searchlist;
|
|
|
|
/* Dependent object that first caused this object to be loaded. */
|
|
struct link_map *l_loader;
|
|
|
|
/* Symbol hash table. */
|
|
Elf_Symndx l_nbuckets;
|
|
const Elf_Symndx *l_buckets, *l_chain;
|
|
|
|
unsigned int l_opencount; /* Reference count for dlopen/dlclose. */
|
|
enum /* Where this object came from. */
|
|
{
|
|
lt_executable, /* The main executable program. */
|
|
lt_library, /* Library needed by main executable. */
|
|
lt_loaded /* Extra run-time loaded shared object. */
|
|
} l_type:2;
|
|
unsigned int l_relocated:1; /* Nonzero if object's relocations done. */
|
|
unsigned int l_init_called:1; /* Nonzero if DT_INIT function called. */
|
|
unsigned int l_global:1; /* Nonzero if object in _dl_global_scope. */
|
|
unsigned int l_reserved:2; /* Reserved for internal use. */
|
|
unsigned int l_phdr_allocated:1; /* Nonzero if the data structure pointed
|
|
to by `l_phdr' is allocated. */
|
|
|
|
/* Array with version names. */
|
|
unsigned int l_nversions;
|
|
struct r_found_version *l_versions;
|
|
|
|
/* Collected information about own RPATH directories. */
|
|
struct r_search_path_elem **l_rpath_dirs;
|
|
|
|
/* Collected results of relocation while profiling. */
|
|
ElfW(Addr) *l_reloc_result;
|
|
|
|
/* Pointer to the version information if available. */
|
|
ElfW(Versym) *l_versyms;
|
|
|
|
/* String specifying the path where this object was found. */
|
|
const char *l_origin;
|
|
|
|
/* Start and finish of memory map for this object. l_map_start
|
|
need not be the same as l_addr. */
|
|
ElfW(Addr) l_map_start, l_map_end;
|
|
|
|
/* This is an array defining the lookup scope for this link map.
|
|
There are at most three different scope lists. */
|
|
struct r_scope_elem *l_scope[4];
|
|
|
|
/* A similar array, this time only with the local scope. This is
|
|
used occasionally. */
|
|
struct r_scope_elem *l_local_scope[2];
|
|
|
|
/* This information is kept to check for sure whether a shared
|
|
object is the same as one already loaded. */
|
|
dev_t l_dev;
|
|
ino_t l_ino;
|
|
|
|
/* Collected information about own RUNPATH directories. */
|
|
struct r_search_path_elem **l_runpath_dirs;
|
|
|
|
/* List of object in order of the init and fini calls. */
|
|
struct link_map **l_initfini;
|
|
|
|
/* List of the dependencies introduced through symbol binding. */
|
|
unsigned int l_reldepsmax;
|
|
unsigned int l_reldepsact;
|
|
struct link_map **l_reldeps;
|
|
|
|
/* Various flag words. */
|
|
ElfW(Word) l_feature_1;
|
|
ElfW(Word) l_flags_1;
|
|
};
|
|
|
|
#endif /* link.h */
|