-/* Run-time dynamic linker data structures for loaded ELF shared objects.
-Copyright (C) 1995, 1996 Free Software Foundation, Inc.
-This file is part of the GNU C Library.
+/* Data structure for communication from the run-time dynamic linker for
+ loaded ELF shared objects.
+ Copyright (C) 1995-2014 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 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
-Library General Public License for more details.
+ 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 Library General Public
-License along with the GNU C Library; see the file COPYING.LIB. If
-not, write to the Free Software Foundation, Inc., 675 Mass Ave,
-Cambridge, MA 02139, USA. */
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
#ifndef _LINK_H
#define _LINK_H 1
-#define __need_size_t
-#include <stddef.h>
-
+#include <features.h>
#include <elf.h>
-
-#define __ELF_WORDSIZE 32 /* XXX */
+#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_WORDSIZE, type)
-#define ELFW(type) _ElfW (ELF, __ELF_WORDSIZE, 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. */
+#include <bits/link.h>
/* Rendezvous structure used by the run-time dynamic linker to communicate
details of shared object loading to the debugger. If the executable's
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. */
+ 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)
- if (dyn->d_tag == DT_DEBUG) r_debug = (struct r_debug) dyn->d_un.d_ptr;
+ 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 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. */
+ ElfW(Addr) l_addr; /* Difference between the address in the ELF
+ file and the addresses in memory. */
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. */
-
- const char *l_libname; /* Name requested (before search). */
- /* Indexed pointers to dynamic section.
- [0,DT_NUM) are indexed by the processor-independent tags.
- [DT_NUM,DT_NUM+DT_PROCNUM] are indexed by the tag minus DT_LOPROC. */
- ElfW(Dyn) *l_info[DT_NUM + DT_PROCNUM];
- 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. */
-
- /* Array of DT_NEEDED dependencies and their dependencies, in
- dependency order for symbol lookup. This is null before the
- dependencies have been loaded. */
- struct link_map **l_searchlist;
- unsigned int l_nsearchlist;
-
- /* Symbol hash table. */
- ElfW(Word) l_nbuckets;
- const ElfW(Word) *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_interpreter, /* The interpreter: the dynamic linker. */
- 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_init_running:1; /* Nonzero while DT_INIT function runs. */
- unsigned int l_reserved:3; /* Reserved for internal use. */
+#ifdef __USE_GNU
+
+/* Version numbers for la_version handshake interface. */
+#define LAV_CURRENT 1
+
+/* Activity types signaled through la_activity. */
+enum
+ {
+ LA_ACT_CONSISTENT, /* Link map consistent again. */
+ LA_ACT_ADD, /* New object will be added. */
+ LA_ACT_DELETE /* Objects will be removed. */
};
-\f
-/* Internal functions of the run-time dynamic linker.
- These can be accessed if you link again the dynamic linker
- as a shared library, as in `-lld' or `/lib/ld.so' explicitly;
- but are not normally of interest to user programs.
-
- The `-ldl' library functions in <dlfcn.h> provide a simple
- user interface to run-time dynamic linking. */
-
-
-/* Cached value of `getpagesize ()'. */
-extern size_t _dl_pagesize;
-
-/* File descriptor referring to the zero-fill device. */
-extern int _dl_zerofd;
-
-/* OS-dependent function to open the zero-fill device. */
-extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */
-/* OS-dependent function to write a message on the standard output.
- All arguments are `const char *'; args until a null pointer
- are concatenated to form the message to print. */
-extern void _dl_sysdep_message (const char *string, ...);
-
-/* OS-dependent function to give a fatal error message and exit
- when the dynamic linker fails before the program is fully linked.
- All arguments are `const char *'; args until a null pointer
- are concatenated to form the message to print. */
-extern void _dl_sysdep_fatal (const char *string, ...)
- __attribute__ ((__noreturn__));
-
-/* Nonzero if the program should be "secure" (i.e. it's setuid or somesuch).
- This tells the dynamic linker to ignore environment variables. */
-extern int _dl_secure;
-
-/* This function is called by all the internal dynamic linker functions
- when they encounter an error. ERRCODE is either an `errno' code or
- zero; OBJECT is the name of the problematical shared object, or null if
- it is a general problem; ERRSTRING is a string describing the specific
- problem. */
-
-extern void _dl_signal_error (int errcode,
- const char *object,
- const char *errstring)
- __attribute__ ((__noreturn__));
-
-/* Call OPERATE, catching errors from `dl_signal_error'. If there is no
- error, *ERRSTRING is set to null. If there is an error, *ERRSTRING and
- *OBJECT are set to the strings passed to _dl_signal_error, and the error
- code passed is the return value. */
-extern int _dl_catch_error (const char **errstring,
- const char **object,
- void (*operate) (void));
-
-
-/* Helper function for <dlfcn.h> functions. Runs the OPERATE function via
- _dl_catch_error. Returns zero for success, nonzero for failure; and
- arranges for `dlerror' to return the error details. */
-extern int _dlerror_run (void (*operate) (void));
-
-
-/* Open the shared object NAME and map in its segments.
- LOADER's DT_RPATH is used in searching for NAME.
- If the object is already opened, returns its existing map. */
-extern struct link_map *_dl_map_object (struct link_map *loader,
- const char *name);
-
-/* Similar, but file found at REALNAME and opened on FD.
- REALNAME must malloc'd storage and is used in internal data structures. */
-extern struct link_map *_dl_map_object_from_fd (const char *name,
- int fd, char *realname);
-
-/* Call _dl_map_object on the dependencies of MAP, and
- set up MAP->l_searchlist. */
-extern void _dl_map_object_deps (struct link_map *map);
-
-/* Cache the locations of MAP's hash table. */
-extern void _dl_setup_hash (struct link_map *map);
-
-
-/* Open the shared object NAME, relocate it, and run its initializer if it
- hasn't already been run. LOADER's DT_RPATH is used in searching for
- NAME. MODE is as for `dlopen' (see <dlfcn.h>). If the object is
- already opened, returns its existing map. */
-extern struct link_map *_dl_open (struct link_map *loader,
- const char *name, int mode);
-
-
-
-/* Search loaded objects' symbol tables for a definition of the symbol
- referred to by UNDEF. *SYM is the symbol table entry containing the
- reference; it is replaced with the defining symbol, and the base load
- address of the defining object is returned. Each of SYMBOL_SCOPE[0] and
- SYMBOL_SCOPE[1] that is not null and their dependencies are searched to
- resolve the name. REFERENCE_NAME should name the object containing the
- reference; it is used in error messages. RELOC_ADDR is the address
- being fixed up and the chosen symbol cannot be one with this value. If
- NOPLT is nonzero, then the reference must not be resolved to a PLT
- entry. */
-extern ElfW(Addr) _dl_lookup_symbol (const char *undef,
- const ElfW(Sym) **sym,
- struct link_map *symbol_scope[2],
- const char *reference_name,
- ElfW(Addr) reloc_addr,
- int noplt);
+/* Values representing origin of name for dynamic loading. */
+enum
+ {
+ LA_SER_ORIG = 0x01, /* Original name. */
+ LA_SER_LIBPATH = 0x02, /* Directory from LD_LIBRARY_PATH. */
+ LA_SER_RUNPATH = 0x04, /* Directory from RPATH/RUNPATH. */
+ LA_SER_CONFIG = 0x08, /* Found through ldconfig. */
+ LA_SER_DEFAULT = 0x40, /* Default directory. */
+ LA_SER_SECURE = 0x80 /* Unused. */
+ };
+
+/* Values for la_objopen return value. */
+enum
+ {
+ LA_FLG_BINDTO = 0x01, /* Audit symbols bound to this object. */
+ LA_FLG_BINDFROM = 0x02 /* Audit symbols bound from this object. */
+ };
-/* Look up symbol NAME in MAP's scope and return its run-time address. */
-extern ElfW(Addr) _dl_symbol_value (struct link_map *map, const char *name);
-
-
-/* Structure describing the dynamic linker itself. */
-extern struct link_map _dl_rtld_map;
-
-/* List of objects currently loaded. */
-extern struct link_map *_dl_loaded;
-
-/* Tail of that list which were loaded at startup. */
-extern struct link_map *_dl_startup_loaded;
-
-/* Allocate a `struct link_map' for a new object being loaded,
- and enter it into the _dl_loaded list. */
-extern struct link_map *_dl_new_object (char *realname, const char *libname,
- int type);
-
-/* Relocate the given object (if it hasn't already been).
- If LAZY is nonzero, don't relocate its PLT. */
-extern void _dl_relocate_object (struct link_map *map, int lazy);
-
-/* Return the address of the next initializer function for MAP or one of
- its dependencies that has not yet been run. When there are no more
- initializers to be run, this returns zero. The functions are returned
- in the order they should be called. */
-extern ElfW(Addr) _dl_init_next (struct link_map *map);
-
-/* Call the finalizer functions of all shared objects whose
- initializer functions have completed. */
-extern void _dl_fini (void);
-
-/* The dynamic linker calls this function before and having changing
- any shared object mappings. The `r_state' member of `struct r_debug'
- says what change is taking place. This function's address is
- the value of the `r_brk' member. */
-extern void _dl_r_debug_state (void);
+/* Values for la_symbind flags parameter. */
+enum
+ {
+ LA_SYMB_NOPLTENTER = 0x01, /* la_pltenter will not be called. */
+ LA_SYMB_NOPLTEXIT = 0x02, /* la_pltexit will not be called. */
+ LA_SYMB_STRUCTCALL = 0x04, /* Return value is a structure. */
+ LA_SYMB_DLSYM = 0x08, /* Binding due to dlsym call. */
+ LA_SYMB_ALTVALUE = 0x10 /* Value has been changed by a previous
+ la_symbind call. */
+ };
+
+struct dl_phdr_info
+ {
+ ElfW(Addr) dlpi_addr;
+ const char *dlpi_name;
+ const ElfW(Phdr) *dlpi_phdr;
+ ElfW(Half) dlpi_phnum;
+
+ /* Note: Following 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 each later member is available. */
+
+ /* Incremented when a new object may have been added. */
+ __extension__ unsigned long long int dlpi_adds;
+ /* Incremented when an object may have been removed. */
+ __extension__ unsigned long long int dlpi_subs;
+
+ /* If there is a PT_TLS segment, its module ID as used in
+ TLS relocations, else zero. */
+ size_t dlpi_tls_modid;
+
+ /* The address of the calling thread's instance of this module's
+ PT_TLS segment, if it has one and it has been allocated
+ in the calling thread, otherwise a null pointer. */
+ void *dlpi_tls_data;
+ };
+__BEGIN_DECLS
+
+extern int dl_iterate_phdr (int (*__callback) (struct dl_phdr_info *,
+ size_t, void *),
+ void *__data);
+
+
+/* Prototypes for the ld.so auditing interfaces. These are not
+ defined anywhere in ld.so but instead have to be provided by the
+ auditing DSO. */
+extern unsigned int la_version (unsigned int __version);
+extern void la_activity (uintptr_t *__cookie, unsigned int __flag);
+extern char *la_objsearch (const char *__name, uintptr_t *__cookie,
+ unsigned int __flag);
+extern unsigned int la_objopen (struct link_map *__map, Lmid_t __lmid,
+ uintptr_t *__cookie);
+extern void la_preinit (uintptr_t *__cookie);
+extern uintptr_t la_symbind32 (Elf32_Sym *__sym, unsigned int __ndx,
+ uintptr_t *__refcook, uintptr_t *__defcook,
+ unsigned int *__flags, const char *__symname);
+extern uintptr_t la_symbind64 (Elf64_Sym *__sym, unsigned int __ndx,
+ uintptr_t *__refcook, uintptr_t *__defcook,
+ unsigned int *__flags, const char *__symname);
+extern unsigned int la_objclose (uintptr_t *__cookie);
+
+__END_DECLS
+
+#endif
#endif /* link.h */
git.samba.org / jlayton / glibc.git / blobdiff