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Diffstat (limited to 'newlib/libc/sys/linux/dl/ldsodefs.h')
| -rw-r--r-- | newlib/libc/sys/linux/dl/ldsodefs.h | 535 |
1 files changed, 535 insertions, 0 deletions
diff --git a/newlib/libc/sys/linux/dl/ldsodefs.h b/newlib/libc/sys/linux/dl/ldsodefs.h new file mode 100644 index 000000000..f24e1136b --- /dev/null +++ b/newlib/libc/sys/linux/dl/ldsodefs.h @@ -0,0 +1,535 @@ +/* Run-time dynamic linker data structures for loaded ELF shared objects. + Copyright (C) 1995-1999, 2000, 2001 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 _LDSODEFS_H +#define _LDSODEFS_H 1 + +#include <features.h> + +#define __need_size_t +#define __need_NULL +#include <stddef.h> +#include <string.h> + +#include <elf.h> +#include <dlfcn.h> +#include <link.h> +#include <dl-lookupcfg.h> +#include <bits/libc-lock.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 internal_function +/* All references to the value of l_info[DT_PLTGOT], + l_info[DT_STRTAB], l_info[DT_SYMTAB], l_info[DT_RELA], + l_info[DT_REL], l_info[DT_JMPREL], and l_info[VERSYMIDX (DT_VERSYM)] + have to be accessed via the D_PTR macro. The macro is needed since for + most architectures the entry is already relocated - but for some not + and we need to relocate at access time. */ +#ifdef DL_RO_DYN_SECTION +# define D_PTR(map,i) (map->i->d_un.d_ptr + map->l_addr) +#else +# define D_PTR(map,i) map->i->d_un.d_ptr +#endif + +/* On some platforms more information than just the address of the symbol + is needed from the lookup functions. In this case we return the whole + link map. */ +#ifdef DL_LOOKUP_RETURNS_MAP +typedef struct link_map *lookup_t; +# define LOOKUP_VALUE(map) map +# define LOOKUP_VALUE_ADDRESS(map) (map ? map->l_addr : 0) +#else +typedef ElfW(Addr) lookup_t; +# define LOOKUP_VALUE(map) map->l_addr +# define LOOKUP_VALUE_ADDRESS(address) address +#endif + +/* on some architectures a pointer to a function is not just a pointer + to the actual code of the function but rather an architecture + specific descriptor. */ +#ifndef ELF_FUNCTION_PTR_IS_SPECIAL +# define DL_SYMBOL_ADDRESS(map, ref) \ + (void *) (LOOKUP_VALUE_ADDRESS (map) + ref->st_value) +# define DL_LOOKUP_ADDRESS(addr) ((ElfW(Addr)) (addr)) +# define DL_DT_INIT_ADDRESS(map, start) (start) +# define DL_DT_FINI_ADDRESS(map, start) (start) +#endif + +/* Unmap a loaded object, called by _dl_close (). */ +#ifndef DL_UNMAP_IS_SPECIAL +# define DL_UNMAP(map) \ + __munmap ((void *) (map)->l_map_start, \ + (map)->l_map_end - (map)->l_map_start) +#endif + +/* By default we do not need special support to initialize DSOs loaded + by statically linked binaries. */ +#ifndef DL_STATIC_INIT +# define DL_STATIC_INIT(map) +#endif + +/* Reloc type classes as returned by elf_machine_type_class(). + ELF_RTYPE_CLASS_PLT means this reloc should not be satisfied by + some PLT symbol, ELF_RTYPE_CLASS_COPY means this reloc should not be + satisfied by any symbol in the executable. */ +#define ELF_RTYPE_CLASS_PLT 1 +#define ELF_RTYPE_CLASS_COPY 2 + +/* ELF uses the PF_x macros to specify the segment permissions, mmap + uses PROT_xxx. In most cases the three macros have the values 1, 2, + and 3 but not in a matching order. The following macros allows + converting from the PF_x values to PROT_xxx values. */ +#define PF_TO_PROT \ + ((PROT_READ << (PF_R * 4)) \ + | (PROT_WRITE << (PF_W * 4)) \ + | (PROT_EXEC << (PF_X * 4)) \ + | ((PROT_READ | PROT_WRITE) << ((PF_R | PF_W) * 4)) \ + | ((PROT_READ | PROT_EXEC) << ((PF_R | PF_X) * 4)) \ + | ((PROT_WRITE | PROT_EXEC) << (PF_W | PF_X) * 4) \ + | ((PROT_READ | PROT_WRITE | PROT_EXEC) << ((PF_R | PF_W | PF_X) * 4))) + + +/* 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 + { + /* This link is only used in the `all_dirs' member of `r_search_path'. */ + struct r_search_path_elem *next; + + /* Strings saying where the definition came from. */ + const char *what; + const char *where; + + /* Basename for this search path element. The string must end with + a slash character. */ + const char *dirname; + size_t dirnamelen; + + enum r_dir_status status[0]; + }; + +struct r_strlenpair + { + const char *str; + size_t len; + }; + + +/* 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. */ + int dont_free; /* Flag whether this element should be freed + if the object is not entirely unloaded. */ + }; + + +/* 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; + +/* OS version. */ +extern unsigned int _dl_osversion; + +/* 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; +/* Filename of the output file. */ +extern const char *_dl_profile_output; + +/* If nonzero the appropriate debug information is printed. */ +extern int _dl_debug_mask; +#define DL_DEBUG_LIBS (1 << 0) +#define DL_DEBUG_IMPCALLS (1 << 1) +#define DL_DEBUG_BINDINGS (1 << 2) +#define DL_DEBUG_SYMBOLS (1 << 3) +#define DL_DEBUG_VERSIONS (1 << 4) +#define DL_DEBUG_RELOC (1 << 5) +#define DL_DEBUG_FILES (1 << 6) +#define DL_DEBUG_STATISTICS (1 << 7) +/* This one is used only internally. */ +#define DL_DEBUG_HELP (1 << 8) + +/* Expect cache ID. */ +extern int _dl_correct_cache_id; + +/* Mask for hardware capabilities that are available. */ +extern unsigned long int _dl_hwcap; + +/* Mask for important hardware capabilities we honour. */ +extern unsigned long int _dl_hwcap_mask; + +/* File descriptor to write debug messages to. */ +extern int _dl_debug_fd; + +/* Names of shared object for which the RPATH should be ignored. */ +extern const char *_dl_inhibit_rpath; + +/* Nonzero if references should be treated as weak during runtime linking. */ +extern int _dl_dynamic_weak; + +/* The array with message we print as a last resort. */ +extern const char _dl_out_of_memory[]; + +/* Nonzero if runtime lookups should not update the .got/.plt. */ +extern int _dl_bind_not; + +/* List of search directories. */ +extern struct r_search_path_elem *_dl_all_dirs; +extern struct r_search_path_elem *_dl_init_all_dirs; + +/* OS-dependent function to open the zero-fill device. */ +extern int _dl_sysdep_open_zero_fill (void); /* dl-sysdep.c */ + + +/* During the program run we must not modify the global data of + loaded shared object simultanously in two threads. Therefore we + protect `_dl_open' and `_dl_close' in dl-close.c. + + This must be a recursive lock since the initializer function of + the loaded object might as well require a call to this function. + At this time it is not anymore a problem to modify the tables. */ +__libc_lock_define_recursive (extern, _dl_load_lock) + + +/* Write message on the debug file descriptor. The parameters are + interpreted as for a `printf' call. All the lines start with a + tag showing the PID. */ +extern void _dl_debug_printf (const char *fmt, ...) + __attribute__ ((__format__ (__printf__, 1, 2))); + +/* Write message on the debug file descriptor. The parameters are + interpreted as for a `printf' call. All the lines buf the first + start with a tag showing the PID. */ +extern void _dl_debug_printf_c (const char *fmt, ...) + __attribute__ ((__format__ (__printf__, 1, 2))); + + +/* Write a message on the specified descriptor FD. The parameters are + interpreted as for a `printf' call. */ +extern void _dl_dprintf (int fd, const char *fmt, ...) + __attribute__ ((__format__ (__printf__, 2, 3))); + +/* Write a message on the specified descriptor standard output. The + parameters are interpreted as for a `printf' call. */ +#define _dl_printf(fmt, args...) \ + _dl_dprintf (STDOUT_FILENO, fmt, ##args) + +/* Write a message on the specified descriptor standard error. The + parameters are interpreted as for a `printf' call. */ +#define _dl_error_printf(fmt, args...) \ + _dl_dprintf (STDERR_FILENO, fmt, ##args) + +/* Write a message on the specified descriptor standard error and exit + the program. The parameters are interpreted as for a `printf' call. */ +#define _dl_fatal_printf(fmt, args...) \ + do \ + { \ + _dl_dprintf (STDERR_FILENO, fmt, ##args); \ + _exit (127); \ + } \ + while (1) + + +/* 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 *occurred, const char *errstring) + internal_function + __attribute__ ((__noreturn__)); + +/* Like _dl_signal_error, but may return when called in the context of + _dl_receive_error. */ +extern void _dl_signal_cerror (int errcode, const char *object, + const char *occation, const char *errstring) + internal_function; + +/* Call OPERATE, receiving errors from `dl_signal_cerror'. 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) + internal_function; + + +/* 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, int mode) + internal_function; + +/* 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) + internal_function; + +/* Cache the locations of MAP's hash table. */ +extern void _dl_setup_hash (struct link_map *map) internal_function; + + +/* 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. + TYPE_CLASS describes the type of symbol we are looking for. */ +extern lookup_t _dl_lookup_symbol (const char *undef, + struct link_map *undef_map, + const ElfW(Sym) **sym, + struct r_scope_elem *symbol_scope[], + int type_class, int explicit) + internal_function; + +/* Lookup versioned symbol. */ +extern lookup_t _dl_lookup_versioned_symbol (const char *undef, + struct link_map *undef_map, + const ElfW(Sym) **sym, + struct r_scope_elem *symbol_scope[], + const struct r_found_version *version, + int type_class, int explicit) + internal_function; + +/* For handling RTLD_NEXT we must be able to skip shared objects. */ +extern lookup_t _dl_lookup_symbol_skip (const char *undef, + struct link_map *undef_map, + const ElfW(Sym) **sym, + struct r_scope_elem *symbol_scope[], + struct link_map *skip_this) + internal_function; + +/* For handling RTLD_NEXT with versioned symbols we must be able to + skip shared objects. */ +extern lookup_t _dl_lookup_versioned_symbol_skip (const char *undef, + struct link_map *undef_map, + const ElfW(Sym) **sym, + struct r_scope_elem *symbol_scope[], + const struct r_found_version *version, + struct link_map *skip_this) + internal_function; + +/* 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) + internal_function; + + +/* Structure describing the dynamic linker itself. */ +extern struct link_map _dl_rtld_map; +/* And a pointer to the map for the main map. */ +extern struct link_map *_dl_loaded; +/* Number of object in the _dl_loaded list. */ +extern unsigned int _dl_nloaded; +/* Array representing global scope. */ +extern struct r_scope_elem *_dl_global_scope[2]; +/* Direct pointer to the searchlist of the main object. */ +extern struct r_scope_elem *_dl_main_searchlist; +/* Copy of the content of `_dl_main_searchlist'. */ +extern struct r_scope_elem _dl_initial_searchlist; +/* This is zero at program start to signal that the global scope map is + allocated by rtld. Later it keeps the size of the map. It might be + reset if in _dl_close if the last global object is removed. */ +extern size_t _dl_global_scope_alloc; + +/* Allocate a `struct link_map' for a new object being loaded, + and enter it into the _dl_main_map list. */ +extern struct link_map *_dl_new_object (char *realname, const char *libname, + int type, struct link_map *loader) + internal_function; + +/* 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 r_scope_elem *scope[], + int lazy, int consider_profiling); + +/* Call _dl_signal_error with a message about an unhandled reloc type. + TYPE is the result of ELFW(R_TYPE) (r_info), i.e. an R_<CPU>_* value. + PLT is nonzero if this was a PLT reloc; it just affects the message. */ +extern void _dl_reloc_bad_type (struct link_map *map, + unsigned int type, int plt) + internal_function __attribute__ ((__noreturn__)); + +/* 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, + int trace_mode) + internal_function; + +/* Check the version dependencies for MAP. If VERBOSE print some more + diagnostics. */ +extern int _dl_check_map_versions (struct link_map *map, int verbose, + int trace_mode) + internal_function; + +/* Initialize the object in SCOPE by calling the constructors with + ARGC, ARGV, and ENV as the parameters. */ +extern void _dl_init (struct link_map *main_map, int argc, char **argv, + char **env) internal_function; + +/* Call the finalizer functions of all shared objects whose + initializer functions have completed. */ +extern void _dl_fini (void) internal_function; + +/* 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) + internal_function; + +/* Initialize the basic data structure for the search paths. */ +extern void _dl_init_paths (const char *library_path) internal_function; + +/* 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) + internal_function; + +/* The actual functions used to keep book on the calls. */ +extern void _dl_mcount (ElfW(Addr) frompc, ElfW(Addr) selfpc); + +/* This function is simply a wrapper around the _dl_mcount function + which does not require a FROMPC parameter since this is the + calling function. */ +extern void _dl_mcount_wrapper (void *selfpc); + +/* Show the members of the auxiliary array passed up from the kernel. */ +extern void _dl_show_auxv (void) internal_function; + +/* Return all environment variables starting with `LD_', one after the + other. */ +extern char *_dl_next_ld_env_entry (char ***position) internal_function; + +/* Return an array with the names of the important hardware capabilities. */ +extern const struct r_strlenpair *_dl_important_hwcaps (const char *platform, + size_t paltform_len, + size_t *sz, + size_t *max_capstrlen) + internal_function; + +/* Look up NAME in ld.so.cache and return the file name stored there, + or null if none is found. */ +extern const char *_dl_load_cache_lookup (const char *name) + internal_function; + +/* If the system does not support MAP_COPY we cannot leave the file open + all the time since this would create problems when the file is replaced. + Therefore we provide this function to close the file and open it again + once needed. */ +extern void _dl_unload_cache (void); + +/* System-dependent function to read a file's whole contents in the + most convenient manner available. *SIZEP gets the size of the + file. On error MAP_FAILED is returned. */ +extern void *_dl_sysdep_read_whole_file (const char *file, size_t *sizep, + int prot) + internal_function; + +/* System-specific function to do initial startup for the dynamic linker. + After this, file access calls and getenv must work. This is responsible + for setting __libc_enable_secure if we need to be secure (e.g. setuid), + and for setting _dl_argc and _dl_argv, and then calling _dl_main. */ +extern ElfW(Addr) _dl_sysdep_start (void **start_argptr, + void (*dl_main) (const ElfW(Phdr) *phdr, + ElfW(Word) phnum, + ElfW(Addr) *user_entry)); + +extern void _dl_sysdep_start_cleanup (void) + internal_function; + + +__END_DECLS + +#endif /* ldsodefs.h */ |