fd26970f33
Tue Jan 21 04:05:20 1997 Ulrich Drepper <drepper@cygnus.com> * version.h (VERSION): Bump to 1.101. Implement -d and -r option to `ldd' to check relocations. * elf/dl-error.c: Add another method to intercept errors. (_dl_receive_error): New function. Install user defined handler. (receiver): New variable. Contains pointer to user provided handler. (_dl_signal_error): If user provided handler is installed call this. * elf/dl-load.c (_dl_map_object): When shared object is not found in trace mode initialize a few more fields so that lookup can actually happen but always fails. * elf/ldd.sh.in: Rewrite argument handling. Recognize new arguments to trigger reloation test. Return with appropriate error code if a file wasn't found. Print warning if object is not executable. * elf/ldd.bash.in: Likewise. * elf/link.h (receiver_fct): New type. Used in _dl_receive_error. (_dl_sysdep_error): New prototype. (_dl_receive_error): New prototype. (_dl_signal_error): Remove __attribute__ ((__noreturn__)). * elf/rtld.c (dl_main): Rewrite argument handling. More than one argument allowed. Recognize --data-relocs and --function-relocs arguments. Don't determine `lazy' mode from LD_BIND_NOW environment variable when in trace mode. If in trace mode and either --data-relocs or --function-relocs is given perform relocation. Report errors using print_unresolved function. (print_unresolved): New function. Print information about missing symbol on stderr. * sysdeps/generic/dl-sysdep.c (_dl_sysdep_error): New function. Like _dl_sysdep_message but print to stderr. * sysdeps/mach/hurd/dl-sysdep.c: Likewise. * sysdeps/generic/sockaddrcom.h: Add definition of sa_family_t. Reported by Andreas Schwab. (__SOCKADDR_COMMON): Use sa_family_t for family member. * sysdeps/unix/bsd/bsd4.4/sockaddrcom.h: Likewise. Linux/Sparc support by Miguel de Icaza. * sysdeps/sparc/fpu_control.h: New file. * sysdeps/unix/sysv/linux/sparc/__sigtrampoline.S: New file. * sysdeps/unix/sysv/linux/sparc/brk.c: New file. * sysdeps/unix/sysv/linux/sparc/profil-counter.h: New file. * sysdeps/unix/sysv/linux/sparc/sigaction.c: New file. * sysdeps/unix/sysv/linux/sparc/socket.S: New file. * sysdeps/unix/sysv/linux/sparc/syscall.S: New file. * sysdeps/unix/sysv/linux/sparc/sysdep.h: New file. * sysdeps/unix/sysv/linux/sparc/Dist: New file. * sysdeps/unix/sysv/linux/sparc/Makefile: New file. * sysdeps/unix/sysv/linux/net/if_arp.h: Don't use kernel header. Provide own definition based on 4.4BSD and Linux. * sysdeps/unix/sysv/linux/net/ppp_defs.h: Define __u32 before including <linux/ppp_defs.h>. * sysdeps/unix/sysv/linux/sys/msq_buf.h (struct msqid_ds): Don't use __pid_t since the kernel might have a different size. * sysdeps/unix/sysv/linux/sys/shm_buf.h (struct shmid_ds): Likewise. Reported by Andreas Schwab. * time/asctime.c: Update copyright. * time/dysize.c: Likewise. * time/gmtime.c: Likewise. * time/timegm.c: Likewise. * time/offtime.c: Likewise. De-ANSI-declfy. * time/tzset.c (__tzset_internal): When TZ envvar does not name a DST timezone don't default to offset -1. * sysdeps/unix/sysv/linux/net/route.h: Don't use kernel header. Reported by a sun <asun@zoology.washington.edu>. * resolv/Makefile: Correct spelling: subdirs-dirs -> subdir-dirs. * sysdeps/stub/sysv_signal.c: New file. Stub implementation. * Makefile (distribute): Add mcheck.h. * nis/Makefile (distribute): Add nss-nis.h. * libio/Makefile (routines): Change vdprintf to iovdprintf to prevent dist problem. * nss/Makefile (distribute): Add digits_dots.c. * sysdeps/unix/sysv/linux/Dist: Add kernel_sigaction.h. * sysdeps/unix/sysv/linux/alpha/Dist: Add sys/procfs.h. * sysdeps/unix/sysv/linux/sparc/Dist: Add clone.S. * new-malloc/Makefile (distribute): Add mcheck-init.c and mcheck.h. Mon Jan 20 17:54:28 1997 Sven Verdoolaege <skimo@breughel.ufsia.ac.be> * manual/filesys.texi: Fix little problem (reentrant->readdir). Fri Jan 17 19:07:07 1997 Andreas Schwab <schwab@issan.informatik.uni-dortmund.de> * configure.in [$elf=yes]: Check for support of .previous and .popsection in the assembler. * config.h.in: Add HAVE_ASM_PREVIOUS_DIRECTIVE and HAVE_ASM_POPSECTION_DIRECTIVE. * libc-symbols.h (__make_section_unallocated) [HAVE_ELF]: Define appropriate if either .previous or .popsection is supported. (libc_warning) [HAVE_ELF]: Use it here. Sat Jan 18 22:15:26 1997 Richard Henderson <rth@tamu.edu> * Makeconfig (CFLAGS-.so): Add -fno-common to prevent odd sorts of errors that can occur when linking libc.so. Mon Jan 20 05:20:49 1997 Ulrich Drepper <drepper@cygnus.com> * elf/dl-load.c (open_path): When running setuid don't try a directory if it is not given with the full name. * elf/Makefile (before-compile): New variable. Mention trusted-dirs.h. (trusted-dirs.h): Construct file from $(default-rpath) and $(user-defined-trusted-dirs) variables. * elf/dl-load.c (_dl_map_object): Pass additional argument to open_path which is NULL except for the LD_LIBRARY_PATH pass in which case it is a pointer to the list of directories from the trusted-dirs.h file. (open_path): Accept additional argument with list of trusted dirs. When running setuid and a list of trusted dirs is given only use those which are mentioned in the list. * elf/rtld.c (dl_main): Don't reject whole LD_LIBRARY_PATH when running setuid. Instead accept entries which do not contain a '/'. * Makeconfig: Correct comment about +(default_cflags). Mon Jan 20 05:11:14 1997 Hrvoje Niksic <hniksic@srce.hr> * time/strptime.c (recursive): Use && not || to test for valid argument. Mon Jan 20 05:06:50 1997 Ulrich Drepper <drepper@cygnus.com> * elf/ldd.sh.in: Exit with value 1 if an error occured. * elf/ldd.bash.in: Likewise. * elf/rtld.c (dl_main): Do not always ignore LD_PRELOAD when the binary runs setuid. It is save to use those entries which do not contain a '/'. This is compatible with Solaris-2.
342 lines
14 KiB
C
342 lines
14 KiB
C
/* Run-time dynamic linker data structures for loaded ELF shared objects.
|
||
Copyright (C) 1995, 1996, 1997 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
|
||
|
||
#define __need_size_t
|
||
#include <stddef.h>
|
||
|
||
#include <elf.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(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 <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)
|
||
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. */
|
||
|
||
/* 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.
|
||
[DT_NUM+DT_PROCNUM,DT_NUM+DT_PROCNUM+DT_EXTRANUM) are indexed
|
||
by DT_EXTRATAGIDX(tagvalue) (see <elf.h>). */
|
||
|
||
ElfW(Dyn) *l_info[DT_NUM + DT_PROCNUM + 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. */
|
||
|
||
/* 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;
|
||
|
||
/* We keep another list in which we keep duplicates. This is
|
||
needed in _dl_lookup_symbol_skip to implemented RTLD_NEXT. */
|
||
struct link_map **l_dupsearchlist;
|
||
unsigned int l_ndupsearchlist;
|
||
|
||
/* Dependent object that first caused this object to be loaded. */
|
||
struct link_map *l_loader;
|
||
|
||
/* Symbol hash table. */
|
||
ElfW(Symndx) l_nbuckets;
|
||
const ElfW(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_init_running:1; /* Nonzero while DT_INIT function runs. */
|
||
unsigned int l_global:1; /* Nonzero if object in _dl_global_scope. */
|
||
unsigned int l_reserved:2; /* Reserved for internal use. */
|
||
};
|
||
|
||
|
||
/* Function used as argument for `_dl_receive_error' function. The
|
||
arguments are the error string and the objname the error occurred
|
||
in. */
|
||
typedef void (*receiver_fct) (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. */
|
||
|
||
|
||
/* 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 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. */
|
||
extern void _dl_sysdep_error (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);
|
||
|
||
/* 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. ERRSTRING if nonzero points to a
|
||
malloc'ed string which the caller has to free after use. */
|
||
extern int _dl_catch_error (char **errstring,
|
||
const char **object,
|
||
void (*operate) (void));
|
||
|
||
/* Call OPERATE, receiving errors from `dl_signal_error'. Unlike
|
||
`_dl_catch_error' the operation is resumed after the OPERATE
|
||
function returns. */
|
||
extern void _dl_receive_error (receiver_fct fct, 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, 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. FLAGS is a
|
||
set of flags: */
|
||
#define DL_LOOKUP_NOEXEC 1 /* Don't search the executable for a
|
||
definition; this is used for copy
|
||
relocs. */
|
||
#define DL_LOOKUP_NOPLT 2 /* 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[],
|
||
const char *reference_name,
|
||
int flags);
|
||
|
||
/* 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,
|
||
int flags);
|
||
|
||
/* 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);
|
||
|
||
/* 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);
|
||
|
||
|
||
#endif /* link.h */
|