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-rw-r--r--elf/link.h368
1 files changed, 12 insertions, 356 deletions
diff --git a/elf/link.h b/elf/link.h
index 9b0f898b11..30efa0ed25 100644
--- a/elf/link.h
+++ b/elf/link.h
@@ -1,4 +1,5 @@
-/* Run-time dynamic linker data structures for loaded ELF shared objects.
+/* Data structure for communication from the run-time dynamic linker for
+ loaded ELF shared objects.
Copyright (C) 1995, 1996, 1997, 1998 Free Software Foundation, Inc.
This file is part of the GNU C Library.
@@ -21,20 +22,12 @@
#define _LINK_H 1
#include <features.h>
-
-#define __need_size_t
-#define __need_NULL
-#include <stddef.h>
-
#include <elf.h>
#include <dlfcn.h>
-__BEGIN_DECLS
-
/* 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(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
@@ -78,56 +71,24 @@ extern struct r_debug _r_debug;
for (dyn = _DYNAMIC; dyn->d_tag != DT_NULL)
if (dyn->d_tag == DT_DEBUG) r_debug = (struct r_debug) dyn->d_un.d_ptr;
*/
-
extern ElfW(Dyn) _DYNAMIC[];
-/* For the version handling we need an array with only names and their
- hash values. */
-struct r_found_version
- {
- const char *name;
- ElfW(Word) hash;
-
- int hidden;
- const char *filename;
- };
-
-/* We want to cache information about the searches for shared objects. */
-
-enum r_dir_status { unknown, nonexisting, existing };
-
-struct r_search_path_elem
- {
- const char *dirname;
-
- size_t dirnamelen;
- enum r_dir_status dirstatus;
-
- size_t machdirnamelen;
- enum r_dir_status machdirstatus;
-
- /* Strings saying where the definition came from. */
- const char *what;
- const char *where;
- /* This link is only used in the `all_dirs' member of `r_search_path'. */
- struct r_search_path_elem *next;
- };
-
-
-/* A data structure for a simple single linked list of strings. */
-struct libname_list
- {
- const char *name; /* Name requested (before search). */
- struct libname_list *next; /* Link to next name for this object. */
- };
+/* 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;
/* 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. */
+ 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
{
@@ -142,7 +103,7 @@ struct link_map
/* All following members are internal to the dynamic linker.
They may change without notice. */
- struct libname_list *l_libname;
+ 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_PROCNUM) are indexed by the tag minus DT_LOPROC.
@@ -202,309 +163,4 @@ struct link_map
ElfW(Half) *l_versyms;
};
-
-/* Test whether given NAME matches any of the names of the given object. */
-static __inline int
-__attribute__ ((unused))
-_dl_name_match_p (const char *__name, struct link_map *__map)
-{
- int __found = strcmp (__name, __map->l_name) == 0;
- struct libname_list *__runp = __map->l_libname;
-
- while (! __found && __runp != NULL)
- if (strcmp (__name, __runp->name) == 0)
- __found = 1;
- else
- __runp = __runp->next;
-
- return __found;
-}
-
-/* Function used as argument for `_dl_receive_error' function. The
- arguments are the error code, error string, and the objname the
- error occurred in. */
-typedef void (*receiver_fct) (int, const char *, const char *);
-
-/* 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. */
-
-
-/* Parameters passed to the dynamic linker. */
-extern char **_dl_argv;
-
-/* Cached value of `getpagesize ()'. */
-extern size_t _dl_pagesize;
-
-/* File descriptor referring to the zero-fill device. */
-extern int _dl_zerofd;
-
-/* Name of the shared object to be profiled (if any). */
-extern const char *_dl_profile;
-/* Map of shared object to be profiled. */
-extern struct link_map *_dl_profile_map;
-
-/* If nonzero the appropriate debug information is printed. */
-extern int _dl_debug_libs;
-extern int _dl_debug_impcalls;
-extern int _dl_debug_bindings;
-extern int _dl_debug_symbols;
-extern int _dl_debug_versions;
-extern int _dl_debug_reloc;
-extern int _dl_debug_files;
-
-/* File deccriptor to write debug messages to. */
-extern int _dl_debug_fd;
-
-/* 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 specified
- descriptor FD. All arguments are `const char *'; args until a null
- pointer are concatenated to form the message to print. */
-extern void _dl_sysdep_output (int fd, const char *string, ...);
-
-/* OS-dependent function to write a debug message on the specified
- descriptor for this. All arguments are `const char *'; args until
- a null pointer are concatenated to form the message to print. If
- NEW_LINE is nonzero it is assumed that the message starts on a new
- line.*/
-extern void _dl_debug_message (int new_line, const char *string, ...);
-
-/* 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. */
-#define _dl_sysdep_message(string, args...) \
- _dl_sysdep_output (STDOUT_FILENO, string, ##args)
-
-/* OS-dependent function to write a message on the standard error.
- All arguments are `const char *'; args until a null pointer
- are concatenated to form the message to print. */
-#define _dl_sysdep_error(string, args...) \
- _dl_sysdep_output (STDERR_FILENO, string, ##args)
-
-/* 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. */
-#define _dl_sysdep_fatal(string, args...) \
- do \
- { \
- _dl_sysdep_output (STDERR_FILENO, string, ##args); \
- _exit (127); \
- } \
- while (1)
-
-/* 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);
-
-/* Call OPERATE, catching errors from `dl_signal_error'. If there is no
- error, *ERRSTRING is set to null. If there is an error, *ERRSTRING is
- set to a string constructed from the strings passed to _dl_signal_error,
- and the error code passed is the return value. ERRSTRING if nonzero
- points to a malloc'ed string which the caller has to free after use.
- ARGS is passed as argument to OPERATE. */
-extern int _dl_catch_error (char **errstring,
- void (*operate) (void *),
- void *args);
-
-/* Call OPERATE, receiving errors from `dl_signal_error'. Unlike
- `_dl_catch_error' the operation is resumed after the OPERATE
- function returns.
- ARGS is passed as argument to OPERATE. */
-extern void _dl_receive_error (receiver_fct fct, void (*operate) (void *),
- void *args);
-
-
-/* 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.
- ARGS is passed as argument to OPERATE. */
-extern int _dlerror_run (void (*operate) (void *), void *args);
-
-
-/* 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.
- For preloaded shared objects PRELOADED is set to a non-zero
- value to allow additional security checks. */
-extern struct link_map *_dl_map_object (struct link_map *loader,
- const char *name, int preloaded,
- int type, int trace_mode);
-
-/* Call _dl_map_object on the dependencies of MAP, and set up
- MAP->l_searchlist. PRELOADS points to a vector of NPRELOADS previously
- loaded objects that will be inserted into MAP->l_searchlist after MAP
- but before its dependencies. */
-extern void _dl_map_object_deps (struct link_map *map,
- struct link_map **preloads,
- unsigned int npreloads, int trace_mode);
-
-/* 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. MODE is as for `dlopen' (see <dlfcn.h>). If
- the object is already opened, returns its existing map. */
-extern struct link_map *_dl_open (const char *name, int mode);
-
-/* Close an object previously opened by _dl_open. */
-extern void _dl_close (struct link_map *map);
-
-
-/* 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. SYMBOL_SCOPE is a
- null-terminated list of object scopes to search; each object's
- l_searchlist (i.e. the segment of the dependency tree starting at that
- object) is searched in turn. REFERENCE_NAME should name the object
- containing the reference; it is used in error messages.
- RELOC_TYPE is a machine-dependent reloc type, which is passed to
- the `elf_machine_lookup_*_p' macros in dl-machine.h to affect which
- symbols can be chosen. */
-extern ElfW(Addr) _dl_lookup_symbol (const char *undef,
- const ElfW(Sym) **sym,
- struct link_map *symbol_scope[],
- const char *reference_name,
- int reloc_type);
-
-/* Lookup versioned symbol. */
-extern ElfW(Addr) _dl_lookup_versioned_symbol (const char *undef,
- const ElfW(Sym) **sym,
- struct link_map *symbol_scope[],
- const char *reference_name,
- const struct r_found_version *version,
- int reloc_type);
-
-/* For handling RTLD_NEXT we must be able to skip shared objects. */
-extern ElfW(Addr) _dl_lookup_symbol_skip (const char *undef,
- const ElfW(Sym) **sym,
- struct link_map *symbol_scope[],
- const char *reference_name,
- struct link_map *skip_this);
-
-/* For handling RTLD_NEXT with versioned symbols we must be able to
- skip shared objects. */
-extern ElfW(Addr) _dl_lookup_versioned_symbol_skip (const char *undef,
- const ElfW(Sym) **sym,
- struct link_map *symbol_scope[],
- const char *reference_name,
- const struct r_found_version *version,
- struct link_map *skip_this);
-
-/* Locate shared object containing the given address. */
-extern int _dl_addr (const void *address, Dl_info *info);
-
-/* 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;
-
-/* The list of objects currently loaded is the third element of the
- `_dl_default_scope' array, and the fourth element is always null.
- This leaves two slots before it that are used when resolving
- DT_SYMBOLIC objects' references one after it for normal references
- (see below). */
-#define _dl_loaded (_dl_default_scope[2])
-extern struct link_map *_dl_default_scope[5];
-
-/* Null-terminated list of objects in the dynamic `global scope'. The
- list starts at [2]; i.e. &_dl_global_scope[2] is the argument
- passed to _dl_lookup_symbol to search the global scope. To search
- a specific object and its dependencies in preference to the global
- scope, fill in the [1] slot and pass its address; for two specific
- object scopes, fill [0] and [1]. The list is double-terminated; to
- search the global scope and then a specific object and its
- dependencies, set *_dl_global_scope_end. This variable initially
- points to _dl_default_scope, and _dl_loaded is always kept in [2]
- of this list. A new list is malloc'd when new objects are loaded
- with RTLD_GLOBAL. */
-extern struct link_map **_dl_global_scope, **_dl_global_scope_end;
-extern size_t _dl_global_scope_alloc; /* Number of slots malloc'd. */
-
-/* Hack _dl_global_scope[0] and [1] as necessary, and return a pointer into
- _dl_global_scope that should be passed to _dl_lookup_symbol for symbol
- references made in the object MAP's relocations. */
-extern struct link_map **_dl_object_relocation_scope (struct link_map *map);
-
-
-/* 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).
- SCOPE is passed to _dl_lookup_symbol in symbol lookups.
- If LAZY is nonzero, don't relocate its PLT. */
-extern void _dl_relocate_object (struct link_map *map,
- struct link_map *scope[],
- int lazy);
-
-/* Check the version dependencies of all objects available through
- MAP. If VERBOSE print some more diagnostics. */
-extern int _dl_check_all_versions (struct link_map *map, int verbose);
-
-/* Check the version dependencies for MAP. If VERBOSE print some more
- diagnostics. */
-extern int _dl_check_map_versions (struct link_map *map, int verbose);
-
-/* 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_debug_state (void);
-
-/* Initialize `struct r_debug' if it has not already been done. The
- argument is the run-time load address of the dynamic linker, to be put
- in the `r_ldbase' member. Returns the address of the structure. */
-extern struct r_debug *_dl_debug_initialize (ElfW(Addr) ldbase);
-
-/* Initialize the basic data structure for the search paths. */
-extern void _dl_init_paths (const char *library_path);
-
-/* Gather the information needed to install the profiling tables and start
- the timers. */
-extern void _dl_start_profile (struct link_map *map, const char *output_dir);
-
-/* The actual functions used to keep book on the calls. */
-extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc);
-
-
-/* Show the members of the auxiliary array passed up from the kernel. */
-extern void _dl_show_auxv (void);
-
-/* Return all environment variables starting with `LD_', one after the
- other. */
-extern char *_dl_next_ld_env_entry (char ***position);
-
-__END_DECLS
-
#endif /* link.h */