File: [local] / src / libexec / ld.so / dlfcn.c (download)
Revision 1.33, Wed Oct 1 02:55:23 2003 UTC (20 years, 8 months ago) by millert
Branch: MAIN
CVS Tags: OPENBSD_3_5_BASE, OPENBSD_3_5 Changes since 1.32: +10 -1 lines
Add break statements in switch missing from revision 1.32.
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/* $OpenBSD: dlfcn.c,v 1.33 2003/10/01 02:55:23 millert Exp $ */
/*
* Copyright (c) 1998 Per Fogelstrom, Opsycon AB
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#define _DYN_LOADER
#include <sys/types.h>
#include <nlist.h>
#include <link.h>
#include <dlfcn.h>
#include <unistd.h>
#include "syscall.h"
#include "archdep.h"
#include "resolve.h"
int _dl_errno;
static int _dl_real_close(void *handle);
static void _dl_unload_deps(elf_object_t *object);
static void _dl_thread_kern_stop(void);
static void _dl_thread_kern_go(void);
static void (*_dl_thread_fnc)(int) = NULL;
void *
dlopen(const char *libname, int flags)
{
elf_object_t *object, *dynobj;
Elf_Dyn *dynp;
if (libname == NULL)
return _dl_objects;
DL_DEB(("dlopen: loading: %s\n", libname));
_dl_thread_kern_stop();
object = _dl_load_shlib(libname, _dl_objects, OBJTYPE_DLO, flags);
/* this add_object should not be here, XXX */
if (object == 0) {
_dl_thread_kern_go();
return((void *)0);
}
_dl_add_object(object);
_dl_link_sub(object, _dl_objects);
_dl_thread_kern_go();
if (object->refcount > 1)
return((void *)object); /* Already loaded */
/*
* Check for 'needed' objects. For each 'needed' object we
* create a 'shadow' object and add it to a list attached to
* the object so we know our dependencies. This list should
* also be used to determine the library search order when
* resolving undefined symbols. This is not yet done. XXX
*/
dynobj = object;
while (dynobj) {
elf_object_t *tmpobj = dynobj;
for (dynp = dynobj->load_dyn; dynp->d_tag; dynp++) {
const char *libname;
elf_object_t *depobj;
if (dynp->d_tag != DT_NEEDED)
continue;
libname = dynobj->dyn.strtab + dynp->d_un.d_val;
_dl_thread_kern_stop();
depobj = _dl_load_shlib(libname, dynobj, OBJTYPE_LIB,
flags|RTLD_GLOBAL);
if (!depobj)
_dl_exit(4);
/* this add_object should not be here, XXX */
_dl_add_object(depobj);
_dl_link_sub(depobj, dynobj);
_dl_thread_kern_go();
tmpobj->dep_next = _dl_malloc(sizeof(elf_object_t));
tmpobj->dep_next->next = depobj;
tmpobj = tmpobj->dep_next;
}
dynobj = dynobj->next;
}
_dl_rtld(object);
_dl_call_init(object);
if (_dl_debug_map->r_brk) {
_dl_debug_map->r_state = RT_ADD;
(*((void (*)(void))_dl_debug_map->r_brk))();
_dl_debug_map->r_state = RT_CONSISTENT;
(*((void (*)(void))_dl_debug_map->r_brk))();
}
return((void *)object);
}
void *
dlsym(void *handle, const char *name)
{
elf_object_t *object;
elf_object_t *dynobj;
void *retval;
const Elf_Sym *sym = NULL;
object = (elf_object_t *)handle;
dynobj = _dl_objects;
while (dynobj && dynobj != object)
dynobj = dynobj->next;
if (!dynobj || object != dynobj) {
_dl_errno = DL_INVALID_HANDLE;
return(0);
}
retval = (void *)_dl_find_symbol(name, object, &sym,
SYM_SEARCH_SELF|SYM_NOWARNNOTFOUND|SYM_NOTPLT, 0, object);
if (sym != NULL)
retval += sym->st_value;
else
_dl_errno = DL_NO_SYMBOL;
return (retval);
}
int
dlctl(void *handle, int command, void *data)
{
int retval;
switch (command) {
case DL_SETTHREADLCK:
DL_DEB(("dlctl: _dl_thread_fnc set to %p\n", data));
_dl_thread_fnc = data;
retval = 0;
break;
default:
_dl_errno = DL_INVALID_CTL;
retval = -1;
break;
}
return (retval);
}
int
dlclose(void *handle)
{
int retval;
if (handle == _dl_objects)
return 0;
retval = _dl_real_close(handle);
if (_dl_debug_map->r_brk) {
_dl_debug_map->r_state = RT_DELETE;
(*((void (*)(void))_dl_debug_map->r_brk))();
_dl_debug_map->r_state = RT_CONSISTENT;
(*((void (*)(void))_dl_debug_map->r_brk))();
}
return (retval);
}
static int
_dl_real_close(void *handle)
{
elf_object_t *object;
elf_object_t *dynobj;
object = (elf_object_t *)handle;
dynobj = _dl_objects;
while (dynobj && dynobj != object)
dynobj = dynobj->next;
if (!dynobj || object != dynobj) {
_dl_errno = DL_INVALID_HANDLE;
return (1);
}
if (object->refcount == 1) {
if (dynobj->dep_next)
_dl_unload_deps(dynobj);
}
_dl_unload_shlib(object);
return (0);
}
/*
* Scan through the shadow dep list and 'unload' every library
* we depend upon. Shadow objects are removed when removing ourself.
*/
static void
_dl_unload_deps(elf_object_t *object)
{
elf_object_t *depobj;
depobj = object->dep_next;
while (depobj) {
if (depobj->next->refcount == 1) { /* This object will go away */
if (depobj->next->dep_next)
_dl_unload_deps(depobj->next);
_dl_unload_shlib(depobj->next);
}
depobj = depobj->dep_next;
}
}
/*
* Return a character string describing the last dl... error occurred.
*/
const char *
dlerror(void)
{
const char *errmsg;
switch (_dl_errno) {
case 0: /* NO ERROR */
errmsg = NULL;
break;
case DL_NOT_FOUND:
errmsg = "File not found";
break;
case DL_CANT_OPEN:
errmsg = "Can't open file";
break;
case DL_NOT_ELF:
errmsg = "File not an ELF object";
break;
case DL_CANT_OPEN_REF:
errmsg = "Can't open referenced object";
break;
case DL_CANT_MMAP:
errmsg = "Can't map ELF object";
break;
case DL_INVALID_HANDLE:
errmsg = "Invalid handle";
break;
case DL_NO_SYMBOL:
errmsg = "Unable to resolve symbol";
break;
case DL_INVALID_CTL:
errmsg = "Invalid dlctl() command";
break;
default:
errmsg = "Unknown error";
}
_dl_errno = 0;
return (errmsg);
}
void
_dl_show_objects(void)
{
elf_object_t *object;
char *objtypename;
int outputfd;
char *pad;
object = _dl_objects;
if (_dl_traceld)
outputfd = STDOUT_FILENO;
else
outputfd = STDERR_FILENO;
if (sizeof(long) == 8)
pad = " ";
else
pad = "";
_dl_fdprintf(outputfd, "\tStart %s End %s Type Ref Name\n",
pad, pad);
while (object) {
switch (object->obj_type) {
case OBJTYPE_LDR:
objtypename = "rtld";
break;
case OBJTYPE_EXE:
objtypename = "exe ";
break;
case OBJTYPE_LIB:
objtypename = "rlib";
break;
case OBJTYPE_DLO:
objtypename = "dlib";
break;
default:
objtypename = "????";
break;
}
_dl_fdprintf(outputfd, "\t%lX %lX %s %d %s\n",
(void *)object->load_addr,
(void *)(object->load_addr + object->load_size),
objtypename, object->refcount, object->load_name);
object = object->next;
}
{
extern int _dl_symcachestat_hits;
extern int _dl_symcachestat_lookups;
DL_DEB(("symcache lookups %d hits %d ratio %d% hits\n",
_dl_symcachestat_lookups, _dl_symcachestat_hits,
(_dl_symcachestat_hits * 100) / _dl_symcachestat_lookups));
}
}
static void
_dl_thread_kern_stop(void)
{
if (_dl_thread_fnc != NULL)
(*_dl_thread_fnc)(0);
}
static void
_dl_thread_kern_go(void)
{
if (_dl_thread_fnc != NULL)
(*_dl_thread_fnc)(1);
}