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rtld.c revision 1.137.2.1
      1  1.137.2.1    bouyer /*	$NetBSD: rtld.c,v 1.137.2.1 2011/03/05 15:09:24 bouyer Exp $	 */
      2        1.1       cgd 
      3        1.1       cgd /*
      4        1.1       cgd  * Copyright 1996 John D. Polstra.
      5        1.1       cgd  * Copyright 1996 Matt Thomas <matt (at) 3am-software.com>
      6       1.87   mycroft  * Copyright 2002 Charles M. Hannum <root (at) ihack.net>
      7        1.1       cgd  * All rights reserved.
      8        1.1       cgd  *
      9        1.1       cgd  * Redistribution and use in source and binary forms, with or without
     10        1.1       cgd  * modification, are permitted provided that the following conditions
     11        1.1       cgd  * are met:
     12        1.1       cgd  * 1. Redistributions of source code must retain the above copyright
     13        1.1       cgd  *    notice, this list of conditions and the following disclaimer.
     14        1.1       cgd  * 2. Redistributions in binary form must reproduce the above copyright
     15        1.1       cgd  *    notice, this list of conditions and the following disclaimer in the
     16        1.1       cgd  *    documentation and/or other materials provided with the distribution.
     17        1.1       cgd  * 3. All advertising materials mentioning features or use of this software
     18        1.1       cgd  *    must display the following acknowledgement:
     19        1.1       cgd  *      This product includes software developed by John Polstra.
     20        1.1       cgd  * 4. The name of the author may not be used to endorse or promote products
     21        1.1       cgd  *    derived from this software without specific prior written permission.
     22        1.1       cgd  *
     23        1.1       cgd  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     24        1.1       cgd  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     25        1.1       cgd  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     26        1.1       cgd  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     27        1.1       cgd  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     28        1.1       cgd  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     29        1.1       cgd  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     30        1.1       cgd  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     31        1.1       cgd  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     32        1.1       cgd  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     33        1.1       cgd  */
     34        1.1       cgd 
     35        1.1       cgd /*
     36        1.1       cgd  * Dynamic linker for ELF.
     37        1.1       cgd  *
     38        1.1       cgd  * John Polstra <jdp (at) polstra.com>.
     39        1.1       cgd  */
     40        1.1       cgd 
     41      1.107     skrll #include <sys/cdefs.h>
     42      1.107     skrll #ifndef lint
     43  1.137.2.1    bouyer __RCSID("$NetBSD: rtld.c,v 1.137.2.1 2011/03/05 15:09:24 bouyer Exp $");
     44      1.107     skrll #endif /* not lint */
     45      1.107     skrll 
     46        1.1       cgd #include <err.h>
     47        1.1       cgd #include <errno.h>
     48        1.1       cgd #include <fcntl.h>
     49        1.1       cgd #include <stdarg.h>
     50        1.1       cgd #include <stdio.h>
     51        1.1       cgd #include <stdlib.h>
     52        1.1       cgd #include <string.h>
     53        1.1       cgd #include <unistd.h>
     54        1.3       cgd #include <sys/param.h>
     55        1.1       cgd #include <sys/mman.h>
     56        1.1       cgd #include <dirent.h>
     57        1.1       cgd 
     58        1.1       cgd #include <ctype.h>
     59        1.1       cgd 
     60        1.2       cgd #include <dlfcn.h>
     61        1.1       cgd #include "debug.h"
     62        1.1       cgd #include "rtld.h"
     63        1.3       cgd 
     64       1.20    kleink #if !defined(lint)
     65        1.3       cgd #include "sysident.h"
     66       1.20    kleink #endif
     67        1.1       cgd 
     68        1.1       cgd /*
     69        1.1       cgd  * Function declarations.
     70        1.1       cgd  */
     71      1.113  christos static void     _rtld_init(caddr_t, caddr_t, const char *);
     72       1.98     skrll static void     _rtld_exit(void);
     73       1.15  christos 
     74       1.98     skrll Elf_Addr        _rtld(Elf_Addr *, Elf_Addr);
     75       1.15  christos 
     76        1.1       cgd 
     77        1.1       cgd /*
     78        1.1       cgd  * Data declarations.
     79        1.1       cgd  */
     80       1.15  christos static char    *error_message;	/* Message for dlopen(), or NULL */
     81        1.1       cgd 
     82       1.15  christos struct r_debug  _rtld_debug;	/* for GDB; */
     83       1.15  christos bool            _rtld_trust;	/* False for setuid and setgid programs */
     84       1.15  christos Obj_Entry      *_rtld_objlist;	/* Head of linked list of shared objects */
     85       1.15  christos Obj_Entry     **_rtld_objtail;	/* Link field of last object in list */
     86       1.15  christos Obj_Entry      *_rtld_objmain;	/* The main program shared object */
     87       1.15  christos Obj_Entry       _rtld_objself;	/* The dynamic linker shared object */
     88      1.131     skrll u_int		_rtld_objcount;	/* Number of objects in _rtld_objlist */
     89      1.131     skrll u_int		_rtld_objloads;	/* Number of objects loaded in _rtld_objlist */
     90      1.120      matt const char	_rtld_path[] = _PATH_RTLD;
     91      1.120      matt 
     92      1.120      matt /* Initialize a fake symbol for resolving undefined weak references. */
     93      1.120      matt Elf_Sym		_rtld_sym_zero = {
     94      1.120      matt     .st_info	= ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE),
     95      1.120      matt     .st_shndx	= SHN_ABS,
     96      1.120      matt };
     97      1.126     skrll size_t	_rtld_pagesz;	/* Page size, as provided by kernel */
     98       1.25   mycroft 
     99       1.22    kleink Search_Path    *_rtld_default_paths;
    100       1.15  christos Search_Path    *_rtld_paths;
    101       1.28  christos 
    102       1.28  christos Library_Xform  *_rtld_xforms;
    103       1.28  christos 
    104        1.1       cgd /*
    105        1.1       cgd  * Global declarations normally provided by crt0.
    106        1.1       cgd  */
    107       1.15  christos char           *__progname;
    108       1.15  christos char          **environ;
    109        1.1       cgd 
    110      1.108       uwe #if defined(RTLD_DEBUG)
    111      1.112       scw #ifndef __sh__
    112        1.9        tv extern Elf_Addr _GLOBAL_OFFSET_TABLE_[];
    113      1.108       uwe #else  /* 32-bit SuperH */
    114      1.108       uwe register Elf_Addr *_GLOBAL_OFFSET_TABLE_ asm("r12");
    115      1.108       uwe #endif
    116      1.108       uwe #endif /* RTLD_DEBUG */
    117       1.15  christos extern Elf_Dyn  _DYNAMIC;
    118        1.8        tv 
    119      1.117        ad static void _rtld_call_fini_functions(int);
    120      1.117        ad static void _rtld_call_init_functions(void);
    121      1.117        ad static void _rtld_initlist_visit(Objlist *, Obj_Entry *, int);
    122      1.117        ad static void _rtld_initlist_tsort(Objlist *, int);
    123       1.98     skrll static Obj_Entry *_rtld_dlcheck(void *);
    124       1.98     skrll static void _rtld_init_dag(Obj_Entry *);
    125       1.98     skrll static void _rtld_init_dag1(Obj_Entry *, Obj_Entry *);
    126       1.98     skrll static void _rtld_objlist_remove(Objlist *, Obj_Entry *);
    127      1.117        ad static void _rtld_objlist_clear(Objlist *);
    128       1.98     skrll static void _rtld_unload_object(Obj_Entry *, bool);
    129       1.98     skrll static void _rtld_unref_dag(Obj_Entry *);
    130       1.98     skrll static Obj_Entry *_rtld_obj_from_addr(const void *);
    131       1.15  christos 
    132        1.1       cgd static void
    133      1.117        ad _rtld_call_fini_functions(int force)
    134        1.1       cgd {
    135      1.117        ad 	Objlist_Entry *elm;
    136      1.117        ad 	Objlist finilist;
    137       1.14        pk 	Obj_Entry *obj;
    138        1.1       cgd 
    139      1.117        ad 	dbg(("_rtld_call_fini_functions(%d)", force));
    140      1.117        ad 
    141      1.117        ad 	SIMPLEQ_INIT(&finilist);
    142      1.117        ad 	_rtld_initlist_tsort(&finilist, 1);
    143      1.117        ad 
    144      1.117        ad 	/* First pass: objects _not_ marked with DF_1_INITFIRST. */
    145      1.117        ad 	SIMPLEQ_FOREACH(elm, &finilist, link) {
    146      1.117        ad 		obj = elm->obj;
    147      1.117        ad 		if (obj->refcount > 0 && !force) {
    148      1.117        ad 			continue;
    149      1.117        ad 		}
    150      1.137     skrll 		if (obj->fini == NULL || obj->fini_called || obj->z_initfirst) {
    151      1.117        ad 		    	continue;
    152      1.117        ad 		}
    153      1.117        ad 		dbg (("calling fini function %s at %p",  obj->path,
    154      1.117        ad 		    (void *)obj->fini));
    155      1.117        ad 		obj->fini_called = 1;
    156      1.117        ad 		(*obj->fini)();
    157      1.117        ad 	}
    158      1.117        ad 
    159      1.117        ad 	/* Second pass: objects marked with DF_1_INITFIRST. */
    160      1.117        ad 	SIMPLEQ_FOREACH(elm, &finilist, link) {
    161      1.117        ad 		obj = elm->obj;
    162      1.117        ad 		if (obj->refcount > 0 && !force) {
    163      1.117        ad 			continue;
    164      1.117        ad 		}
    165      1.117        ad 		if (obj->fini == NULL || obj->fini_called) {
    166      1.117        ad 		    	continue;
    167      1.117        ad 		}
    168      1.117        ad 		dbg (("calling fini function %s at %p (DF_1_INITFIRST)",
    169      1.117        ad 		    obj->path, (void *)obj->fini));
    170      1.117        ad 		obj->fini_called = 1;
    171      1.117        ad 		(*obj->fini)();
    172      1.117        ad 	}
    173      1.117        ad 
    174      1.117        ad         _rtld_objlist_clear(&finilist);
    175        1.1       cgd }
    176        1.1       cgd 
    177        1.1       cgd static void
    178      1.117        ad _rtld_call_init_functions()
    179        1.1       cgd {
    180      1.117        ad 	Objlist_Entry *elm;
    181      1.117        ad 	Objlist initlist;
    182      1.117        ad 	Obj_Entry *obj;
    183       1.94    simonb 
    184      1.117        ad 	dbg(("_rtld_call_init_functions()"));
    185      1.117        ad 	SIMPLEQ_INIT(&initlist);
    186      1.117        ad 	_rtld_initlist_tsort(&initlist, 0);
    187      1.117        ad 
    188      1.117        ad 	/* First pass: objects marked with DF_1_INITFIRST. */
    189      1.117        ad 	SIMPLEQ_FOREACH(elm, &initlist, link) {
    190      1.117        ad 		obj = elm->obj;
    191      1.137     skrll 		if (obj->init == NULL || obj->init_called || !obj->z_initfirst) {
    192      1.117        ad 			continue;
    193      1.117        ad 		}
    194      1.117        ad 		dbg (("calling init function %s at %p (DF_1_INITFIRST)",
    195      1.117        ad 		    obj->path, (void *)obj->init));
    196      1.117        ad 		obj->init_called = 1;
    197      1.117        ad 		(*obj->init)();
    198      1.117        ad 	}
    199      1.117        ad 
    200      1.117        ad 	/* Second pass: all other objects. */
    201      1.117        ad 	SIMPLEQ_FOREACH(elm, &initlist, link) {
    202      1.117        ad 		obj = elm->obj;
    203      1.117        ad 		if (obj->init == NULL || obj->init_called) {
    204      1.117        ad 			continue;
    205      1.117        ad 		}
    206      1.117        ad 		dbg (("calling init function %s at %p",  obj->path,
    207      1.117        ad 		    (void *)obj->init));
    208      1.117        ad 		obj->init_called = 1;
    209      1.117        ad 		(*obj->init)();
    210       1.14        pk 	}
    211      1.117        ad 
    212      1.117        ad         _rtld_objlist_clear(&initlist);
    213        1.1       cgd }
    214       1.14        pk 
    215        1.1       cgd /*
    216        1.1       cgd  * Initialize the dynamic linker.  The argument is the address at which
    217        1.1       cgd  * the dynamic linker has been mapped into memory.  The primary task of
    218      1.105     skrll  * this function is to create an Obj_Entry for the dynamic linker and
    219      1.105     skrll  * to resolve the PLT relocation for platforms that need it (those that
    220      1.105     skrll  * define __HAVE_FUNCTION_DESCRIPTORS
    221        1.1       cgd  */
    222        1.1       cgd static void
    223      1.114  christos _rtld_init(caddr_t mapbase, caddr_t relocbase, const char *execname)
    224        1.1       cgd {
    225       1.94    simonb 
    226       1.14        pk 	/* Conjure up an Obj_Entry structure for the dynamic linker. */
    227      1.120      matt 	_rtld_objself.path = __UNCONST(_rtld_path);
    228      1.120      matt 	_rtld_objself.pathlen = sizeof(_rtld_path)-1;
    229       1.80   mycroft 	_rtld_objself.rtld = true;
    230       1.80   mycroft 	_rtld_objself.mapbase = mapbase;
    231       1.80   mycroft 	_rtld_objself.relocbase = relocbase;
    232       1.80   mycroft 	_rtld_objself.dynamic = (Elf_Dyn *) &_DYNAMIC;
    233      1.119  christos 	_rtld_objself.strtab = "_rtld_sym_zero";
    234        1.1       cgd 
    235      1.120      matt 	/*
    236      1.128     skrll 	 * Set value to -relocbase so that
    237      1.128     skrll 	 *
    238      1.128     skrll 	 *     _rtld_objself.relocbase + _rtld_sym_zero.st_value == 0
    239      1.128     skrll 	 *
    240      1.120      matt 	 * This allows unresolved references to weak symbols to be computed
    241      1.128     skrll 	 * to a value of 0.
    242      1.120      matt 	 */
    243      1.120      matt 	_rtld_sym_zero.st_value = -(uintptr_t)relocbase;
    244      1.120      matt 
    245      1.113  christos 	_rtld_digest_dynamic(_rtld_path, &_rtld_objself);
    246      1.104     skrll 	assert(!_rtld_objself.needed);
    247      1.105     skrll #if !defined(__hppa__)
    248      1.103     skrll 	assert(!_rtld_objself.pltrel && !_rtld_objself.pltrela);
    249      1.105     skrll #else
    250      1.105     skrll 	_rtld_relocate_plt_objects(&_rtld_objself);
    251      1.105     skrll #endif
    252      1.105     skrll #if !defined(__mips__) && !defined(__hppa__)
    253      1.104     skrll 	assert(!_rtld_objself.pltgot);
    254      1.103     skrll #endif
    255       1.97     skrll #if !defined(__arm__) && !defined(__mips__) && !defined(__sh__)
    256       1.97     skrll 	/* ARM, MIPS and SH{3,5} have a bogus DT_TEXTREL. */
    257      1.103     skrll 	assert(!_rtld_objself.textrel);
    258       1.80   mycroft #endif
    259       1.13  christos 
    260      1.114  christos 	_rtld_add_paths(execname, &_rtld_default_paths,
    261      1.114  christos 	    RTLD_DEFAULT_LIBRARY_PATH);
    262       1.13  christos 
    263      1.123       mrg #ifdef RTLD_ARCH_SUBDIR
    264      1.123       mrg 	_rtld_add_paths(execname, &_rtld_default_paths,
    265      1.123       mrg 	    RTLD_DEFAULT_LIBRARY_PATH "/" RTLD_ARCH_SUBDIR);
    266      1.123       mrg #endif
    267      1.123       mrg 
    268       1.14        pk 	/*
    269       1.14        pk 	 * Set up the _rtld_objlist pointer, so that rtld symbols can be found.
    270       1.14        pk 	 */
    271       1.14        pk 	_rtld_objlist = &_rtld_objself;
    272        1.1       cgd 
    273       1.14        pk 	/* Make the object list empty again. */
    274       1.14        pk 	_rtld_objlist = NULL;
    275       1.14        pk 	_rtld_objtail = &_rtld_objlist;
    276      1.129       roy 	_rtld_objcount = 0;
    277        1.1       cgd 
    278       1.14        pk 	_rtld_debug.r_brk = _rtld_debug_state;
    279       1.14        pk 	_rtld_debug.r_state = RT_CONSISTENT;
    280        1.1       cgd }
    281       1.14        pk 
    282        1.1       cgd /*
    283        1.1       cgd  * Cleanup procedure.  It will be called (by the atexit() mechanism) just
    284        1.1       cgd  * before the process exits.
    285        1.1       cgd  */
    286        1.1       cgd static void
    287       1.98     skrll _rtld_exit(void)
    288        1.1       cgd {
    289       1.15  christos 	dbg(("rtld_exit()"));
    290        1.1       cgd 
    291      1.117        ad 	_rtld_call_fini_functions(1);
    292        1.1       cgd }
    293       1.14        pk 
    294        1.1       cgd /*
    295        1.1       cgd  * Main entry point for dynamic linking.  The argument is the stack
    296        1.1       cgd  * pointer.  The stack is expected to be laid out as described in the
    297        1.1       cgd  * SVR4 ABI specification, Intel 386 Processor Supplement.  Specifically,
    298        1.1       cgd  * the stack pointer points to a word containing ARGC.  Following that
    299        1.1       cgd  * in the stack is a null-terminated sequence of pointers to argument
    300        1.1       cgd  * strings.  Then comes a null-terminated sequence of pointers to
    301        1.1       cgd  * environment strings.  Finally, there is a sequence of "auxiliary
    302        1.1       cgd  * vector" entries.
    303        1.1       cgd  *
    304       1.17    kleink  * This function returns the entry point for the main program, the dynamic
    305       1.17    kleink  * linker's exit procedure in sp[0], and a pointer to the main object in
    306       1.17    kleink  * sp[1].
    307        1.1       cgd  */
    308        1.1       cgd Elf_Addr
    309       1.98     skrll _rtld(Elf_Addr *sp, Elf_Addr relocbase)
    310        1.1       cgd {
    311       1.15  christos 	const AuxInfo  *pAUX_base, *pAUX_entry, *pAUX_execfd, *pAUX_phdr,
    312       1.53  christos 	               *pAUX_phent, *pAUX_phnum, *pAUX_euid, *pAUX_egid,
    313       1.53  christos 		       *pAUX_ruid, *pAUX_rgid;
    314       1.18        ws 	const AuxInfo  *pAUX_pagesz;
    315      1.134     joerg 	char          **env, **oenvp;
    316       1.15  christos 	const AuxInfo  *aux;
    317       1.15  christos 	const AuxInfo  *auxp;
    318       1.39   mycroft 	Elf_Addr       *const osp = sp;
    319       1.15  christos 	bool            bind_now = 0;
    320      1.134     joerg 	const char     *ld_bind_now, *ld_preload, *ld_library_path;
    321       1.15  christos 	const char    **argv;
    322      1.114  christos 	const char     *execname;
    323       1.40   mycroft 	long		argc;
    324       1.31       erh 	const char **real___progname;
    325       1.34  christos 	const Obj_Entry **real___mainprog_obj;
    326       1.31       erh 	char ***real_environ;
    327      1.134     joerg #ifdef DEBUG
    328      1.134     joerg 	const char     *ld_debug;
    329       1.12  christos #endif
    330  1.137.2.1    bouyer #ifdef RTLD_DEBUG
    331  1.137.2.1    bouyer 	int i = 0;
    332  1.137.2.1    bouyer #endif
    333        1.1       cgd 
    334       1.15  christos 	/*
    335       1.15  christos          * On entry, the dynamic linker itself has not been relocated yet.
    336       1.15  christos          * Be very careful not to reference any global data until after
    337       1.15  christos          * _rtld_init has returned.  It is OK to reference file-scope statics
    338       1.15  christos          * and string constants, and to call static and global functions.
    339       1.15  christos          */
    340       1.15  christos 	/* Find the auxiliary vector on the stack. */
    341       1.15  christos 	/* first Elf_Word reserved to address of exit routine */
    342       1.60   mycroft #if defined(RTLD_DEBUG)
    343       1.75   mycroft 	debug = 1;
    344       1.88      fvdl 	dbg(("sp = %p, argc = %ld, argv = %p <%s> relocbase %p", sp,
    345       1.88      fvdl 	    (long)sp[2], &sp[3], (char *) sp[3], (void *)relocbase));
    346       1.75   mycroft 	dbg(("got is at %p, dynamic is at %p", _GLOBAL_OFFSET_TABLE_,
    347       1.75   mycroft 	    &_DYNAMIC));
    348       1.71  junyoung 	dbg(("_ctype_ is %p", _ctype_));
    349        1.1       cgd #endif
    350        1.1       cgd 
    351       1.15  christos 	sp += 2;		/* skip over return argument space */
    352       1.15  christos 	argv = (const char **) &sp[1];
    353       1.40   mycroft 	argc = *(long *)sp;
    354       1.39   mycroft 	sp += 2 + argc;		/* Skip over argc, arguments, and NULL
    355       1.15  christos 				 * terminator */
    356       1.15  christos 	env = (char **) sp;
    357       1.15  christos 	while (*sp++ != 0) {	/* Skip over environment, and NULL terminator */
    358       1.60   mycroft #if defined(RTLD_DEBUG)
    359       1.71  junyoung 		dbg(("env[%d] = %p %s", i++, (void *)sp[-1], (char *)sp[-1]));
    360        1.1       cgd #endif
    361       1.15  christos 	}
    362       1.15  christos 	aux = (const AuxInfo *) sp;
    363        1.1       cgd 
    364       1.15  christos 	pAUX_base = pAUX_entry = pAUX_execfd = NULL;
    365       1.15  christos 	pAUX_phdr = pAUX_phent = pAUX_phnum = NULL;
    366       1.53  christos 	pAUX_euid = pAUX_ruid = pAUX_egid = pAUX_rgid = NULL;
    367       1.18        ws 	pAUX_pagesz = NULL;
    368       1.44        pk 
    369      1.114  christos 	execname = NULL;
    370      1.114  christos 
    371       1.69   mycroft 	/* Digest the auxiliary vector. */
    372       1.24    kleink 	for (auxp = aux; auxp->a_type != AT_NULL; ++auxp) {
    373       1.24    kleink 		switch (auxp->a_type) {
    374       1.24    kleink 		case AT_BASE:
    375       1.15  christos 			pAUX_base = auxp;
    376       1.15  christos 			break;
    377       1.24    kleink 		case AT_ENTRY:
    378       1.15  christos 			pAUX_entry = auxp;
    379       1.15  christos 			break;
    380       1.24    kleink 		case AT_EXECFD:
    381       1.15  christos 			pAUX_execfd = auxp;
    382       1.15  christos 			break;
    383       1.24    kleink 		case AT_PHDR:
    384       1.15  christos 			pAUX_phdr = auxp;
    385       1.15  christos 			break;
    386       1.24    kleink 		case AT_PHENT:
    387       1.15  christos 			pAUX_phent = auxp;
    388       1.15  christos 			break;
    389       1.24    kleink 		case AT_PHNUM:
    390       1.15  christos 			pAUX_phnum = auxp;
    391       1.15  christos 			break;
    392       1.54   mycroft #ifdef AT_EUID
    393       1.53  christos 		case AT_EUID:
    394       1.53  christos 			pAUX_euid = auxp;
    395       1.53  christos 			break;
    396       1.53  christos 		case AT_RUID:
    397       1.53  christos 			pAUX_ruid = auxp;
    398       1.53  christos 			break;
    399       1.53  christos 		case AT_EGID:
    400       1.53  christos 			pAUX_egid = auxp;
    401       1.53  christos 			break;
    402       1.53  christos 		case AT_RGID:
    403       1.53  christos 			pAUX_rgid = auxp;
    404       1.53  christos 			break;
    405       1.54   mycroft #endif
    406      1.114  christos #ifdef AT_SUN_EXECNAME
    407      1.114  christos 		case AT_SUN_EXECNAME:
    408      1.114  christos 			execname = (const char *)(const void *)auxp->a_v;
    409      1.114  christos 			break;
    410      1.114  christos #endif
    411       1.24    kleink 		case AT_PAGESZ:
    412       1.18        ws 			pAUX_pagesz = auxp;
    413       1.18        ws 			break;
    414       1.15  christos 		}
    415       1.15  christos 	}
    416       1.18        ws 
    417       1.69   mycroft 	/* Initialize and relocate ourselves. */
    418       1.90  junyoung 	if (pAUX_base == NULL) {
    419       1.90  junyoung 		_rtld_error("Bad pAUX_base");
    420       1.90  junyoung 		_rtld_die();
    421       1.90  junyoung 	}
    422       1.69   mycroft 	assert(pAUX_pagesz != NULL);
    423       1.24    kleink 	_rtld_pagesz = (int)pAUX_pagesz->a_v;
    424      1.114  christos 	_rtld_init((caddr_t)pAUX_base->a_v, (caddr_t)relocbase, execname);
    425        1.1       cgd 
    426       1.15  christos 	__progname = _rtld_objself.path;
    427       1.15  christos 	environ = env;
    428        1.1       cgd 
    429       1.53  christos 	_rtld_trust = ((pAUX_euid ? (uid_t)pAUX_euid->a_v : geteuid()) ==
    430       1.53  christos 	    (pAUX_ruid ? (uid_t)pAUX_ruid->a_v : getuid())) &&
    431       1.53  christos 	    ((pAUX_egid ? (gid_t)pAUX_egid->a_v : getegid()) ==
    432       1.53  christos 	    (pAUX_rgid ? (gid_t)pAUX_rgid->a_v : getgid()));
    433        1.1       cgd 
    434      1.134     joerg #ifdef DEBUG
    435      1.134     joerg 	ld_debug = NULL;
    436      1.134     joerg #endif
    437      1.134     joerg 	ld_bind_now = NULL;
    438      1.134     joerg 	ld_library_path = NULL;
    439      1.134     joerg 	ld_preload = NULL;
    440      1.134     joerg 	/*
    441      1.134     joerg 	 * Inline avoid using normal getenv/unsetenv here as the libc
    442      1.134     joerg 	 * code is quite a bit more complicated.
    443      1.134     joerg 	 */
    444      1.134     joerg 	for (oenvp = env; *env != NULL; ++env) {
    445      1.134     joerg 		static const char bind_var[] = "LD_BIND_NOW=";
    446      1.134     joerg 		static const char debug_var[] =  "LD_DEBUG=";
    447      1.134     joerg 		static const char path_var[] = "LD_LIBRARY_PATH=";
    448      1.134     joerg 		static const char preload_var[] = "LD_PRELOAD=";
    449      1.134     joerg #define LEN(x)	(sizeof(x) - 1)
    450      1.134     joerg 
    451      1.134     joerg 		if ((*env)[0] != 'L' || (*env)[1] != 'D') {
    452      1.134     joerg 			/*
    453      1.134     joerg 			 * Special case to skip most entries without
    454      1.134     joerg 			 * the more expensive calls to strncmp.
    455      1.134     joerg 			 */
    456      1.134     joerg 			*oenvp++ = *env;
    457      1.134     joerg 		} else if (strncmp(*env, debug_var, LEN(debug_var)) == 0) {
    458      1.134     joerg 			if (_rtld_trust) {
    459      1.134     joerg #ifdef DEBUG
    460      1.134     joerg 				ld_debug = *env + LEN(debug_var);
    461      1.134     joerg #endif
    462      1.134     joerg 				*oenvp++ = *env;
    463      1.134     joerg 			}
    464      1.134     joerg 		} else if (strncmp(*env, bind_var, LEN(bind_var)) == 0) {
    465      1.134     joerg 			ld_bind_now = *env + LEN(bind_var);
    466      1.134     joerg 		} else if (strncmp(*env, path_var, LEN(path_var)) == 0) {
    467      1.134     joerg 			if (_rtld_trust) {
    468      1.134     joerg 				ld_library_path = *env + LEN(path_var);
    469      1.134     joerg 				*oenvp++ = *env;
    470      1.134     joerg 			}
    471      1.134     joerg 		} else if (strncmp(*env, preload_var, LEN(preload_var)) == 0) {
    472      1.134     joerg 			if (_rtld_trust) {
    473      1.134     joerg 				ld_preload = *env + LEN(preload_var);
    474      1.134     joerg 				*oenvp++ = *env;
    475      1.134     joerg 			}
    476      1.134     joerg 		} else {
    477      1.134     joerg 			*oenvp++ = *env;
    478      1.134     joerg 		}
    479      1.134     joerg #undef LEN
    480      1.134     joerg 	}
    481      1.134     joerg 	*oenvp++ = NULL;
    482      1.134     joerg 
    483       1.15  christos 	if (ld_bind_now != NULL && *ld_bind_now != '\0')
    484       1.15  christos 		bind_now = true;
    485       1.15  christos 	if (_rtld_trust) {
    486        1.6    mhitch #ifdef DEBUG
    487       1.75   mycroft #ifdef RTLD_DEBUG
    488       1.75   mycroft 		debug = 0;
    489       1.75   mycroft #endif
    490       1.15  christos 		if (ld_debug != NULL && *ld_debug != '\0')
    491       1.15  christos 			debug = 1;
    492       1.15  christos #endif
    493      1.134     joerg 		_rtld_add_paths(execname, &_rtld_paths, ld_library_path);
    494      1.111  christos 	} else {
    495      1.115  christos 		execname = NULL;
    496       1.15  christos 	}
    497      1.114  christos 	_rtld_process_hints(execname, &_rtld_paths, &_rtld_xforms,
    498      1.113  christos 	    _PATH_LD_HINTS);
    499       1.66  junyoung 	dbg(("dynamic linker is initialized, mapbase=%p, relocbase=%p",
    500       1.58   mycroft 	     _rtld_objself.mapbase, _rtld_objself.relocbase));
    501       1.15  christos 
    502       1.15  christos 	/*
    503       1.15  christos          * Load the main program, or process its program header if it is
    504       1.15  christos          * already loaded.
    505       1.15  christos          */
    506       1.15  christos 	if (pAUX_execfd != NULL) {	/* Load the main program. */
    507       1.24    kleink 		int             fd = pAUX_execfd->a_v;
    508      1.110  christos 		const char *obj_name = argv[0] ? argv[0] : "main program";
    509       1.15  christos 		dbg(("loading main program"));
    510      1.110  christos 		_rtld_objmain = _rtld_map_object(obj_name, fd, NULL);
    511       1.15  christos 		close(fd);
    512       1.15  christos 		if (_rtld_objmain == NULL)
    513       1.15  christos 			_rtld_die();
    514       1.15  christos 	} else {		/* Main program already loaded. */
    515       1.15  christos 		const Elf_Phdr *phdr;
    516       1.15  christos 		int             phnum;
    517       1.15  christos 		caddr_t         entry;
    518       1.15  christos 
    519       1.15  christos 		dbg(("processing main program's program header"));
    520       1.15  christos 		assert(pAUX_phdr != NULL);
    521       1.24    kleink 		phdr = (const Elf_Phdr *) pAUX_phdr->a_v;
    522       1.15  christos 		assert(pAUX_phnum != NULL);
    523       1.24    kleink 		phnum = pAUX_phnum->a_v;
    524       1.15  christos 		assert(pAUX_phent != NULL);
    525       1.24    kleink 		assert(pAUX_phent->a_v == sizeof(Elf_Phdr));
    526       1.15  christos 		assert(pAUX_entry != NULL);
    527       1.24    kleink 		entry = (caddr_t) pAUX_entry->a_v;
    528       1.15  christos 		_rtld_objmain = _rtld_digest_phdr(phdr, phnum, entry);
    529       1.84   mycroft 		_rtld_objmain->path = xstrdup(argv[0] ? argv[0] :
    530       1.84   mycroft 		    "main program");
    531       1.89  junyoung 		_rtld_objmain->pathlen = strlen(_rtld_objmain->path);
    532       1.15  christos 	}
    533       1.15  christos 
    534       1.92   mycroft 	_rtld_objmain->mainprog = true;
    535       1.92   mycroft 
    536       1.25   mycroft 	/*
    537       1.25   mycroft 	 * Get the actual dynamic linker pathname from the executable if
    538       1.25   mycroft 	 * possible.  (It should always be possible.)  That ensures that
    539       1.25   mycroft 	 * gdb will find the right dynamic linker even if a non-standard
    540       1.25   mycroft 	 * one is being used.
    541       1.25   mycroft 	 */
    542       1.25   mycroft 	if (_rtld_objmain->interp != NULL &&
    543       1.78   mycroft 	    strcmp(_rtld_objmain->interp, _rtld_objself.path) != 0)
    544       1.25   mycroft 		_rtld_objself.path = xstrdup(_rtld_objmain->interp);
    545       1.66  junyoung 	dbg(("actual dynamic linker is %s", _rtld_objself.path));
    546       1.25   mycroft 
    547      1.114  christos 	_rtld_digest_dynamic(execname, _rtld_objmain);
    548       1.15  christos 
    549       1.84   mycroft 	/* Link the main program into the list of objects. */
    550       1.84   mycroft 	*_rtld_objtail = _rtld_objmain;
    551       1.84   mycroft 	_rtld_objtail = &_rtld_objmain->next;
    552      1.131     skrll 	_rtld_objcount++;
    553      1.131     skrll 	_rtld_objloads++;
    554       1.84   mycroft 
    555       1.15  christos 	_rtld_linkmap_add(_rtld_objmain);
    556       1.15  christos 	_rtld_linkmap_add(&_rtld_objself);
    557       1.15  christos 
    558       1.15  christos 	++_rtld_objmain->refcount;
    559       1.84   mycroft 	_rtld_objmain->mainref = 1;
    560      1.117        ad 	_rtld_objlist_push_tail(&_rtld_list_main, _rtld_objmain);
    561       1.19    kleink 
    562      1.134     joerg 	if (ld_preload) {
    563      1.111  christos 		/*
    564      1.111  christos 		 * Pre-load user-specified objects after the main program
    565      1.111  christos 		 * but before any shared object dependencies.
    566      1.111  christos 		 */
    567      1.111  christos 		dbg(("preloading objects"));
    568      1.134     joerg 		if (_rtld_preload(ld_preload) == -1)
    569      1.127  christos 			_rtld_die();
    570      1.134     joerg 	}
    571       1.15  christos 
    572       1.15  christos 	dbg(("loading needed objects"));
    573      1.137     skrll 	if (_rtld_load_needed_objects(_rtld_objmain, _RTLD_MAIN) == -1)
    574       1.15  christos 		_rtld_die();
    575       1.15  christos 
    576       1.15  christos 	dbg(("relocating objects"));
    577       1.81   mycroft 	if (_rtld_relocate_objects(_rtld_objmain, bind_now) == -1)
    578       1.15  christos 		_rtld_die();
    579       1.15  christos 
    580       1.15  christos 	dbg(("doing copy relocations"));
    581       1.60   mycroft 	if (_rtld_do_copy_relocations(_rtld_objmain) == -1)
    582       1.15  christos 		_rtld_die();
    583       1.15  christos 
    584       1.31       erh 	/*
    585       1.34  christos 	 * Set the __progname,  environ and, __mainprog_obj before
    586       1.34  christos 	 * calling anything that might use them.
    587       1.31       erh 	 */
    588       1.31       erh 	real___progname = _rtld_objmain_sym("__progname");
    589       1.31       erh 	if (real___progname) {
    590       1.64  christos 		if (argv[0] != NULL) {
    591       1.64  christos 			if ((*real___progname = strrchr(argv[0], '/')) == NULL)
    592       1.64  christos 				(*real___progname) = argv[0];
    593       1.64  christos 			else
    594       1.64  christos 				(*real___progname)++;
    595       1.64  christos 		} else {
    596       1.64  christos 			(*real___progname) = NULL;
    597       1.64  christos 		}
    598       1.31       erh 	}
    599       1.31       erh 	real_environ = _rtld_objmain_sym("environ");
    600       1.31       erh 	if (real_environ)
    601       1.31       erh 		*real_environ = environ;
    602       1.99     skrll 	/*
    603       1.99     skrll 	 * Set __mainprog_obj for old binaries.
    604       1.99     skrll 	 */
    605       1.34  christos 	real___mainprog_obj = _rtld_objmain_sym("__mainprog_obj");
    606       1.34  christos 	if (real___mainprog_obj)
    607       1.34  christos 		*real___mainprog_obj = _rtld_objmain;
    608       1.31       erh 
    609       1.15  christos 	dbg(("calling _init functions"));
    610      1.117        ad 	_rtld_call_init_functions();
    611       1.15  christos 
    612       1.15  christos 	dbg(("control at program entry point = %p, obj = %p, exit = %p",
    613       1.15  christos 	     _rtld_objmain->entry, _rtld_objmain, _rtld_exit));
    614       1.15  christos 
    615       1.15  christos 	/*
    616       1.15  christos 	 * Return with the entry point and the exit procedure in at the top
    617       1.15  christos 	 * of stack.
    618       1.15  christos 	 */
    619       1.15  christos 
    620       1.15  christos 	_rtld_debug_state();	/* say hello to gdb! */
    621       1.15  christos 
    622       1.15  christos 	((void **) osp)[0] = _rtld_exit;
    623       1.15  christos 	((void **) osp)[1] = _rtld_objmain;
    624       1.15  christos 	return (Elf_Addr) _rtld_objmain->entry;
    625        1.1       cgd }
    626        1.1       cgd 
    627        1.1       cgd void
    628       1.98     skrll _rtld_die(void)
    629        1.1       cgd {
    630       1.99     skrll 	const char *msg = dlerror();
    631        1.1       cgd 
    632       1.15  christos 	if (msg == NULL)
    633       1.15  christos 		msg = "Fatal error";
    634       1.52     soren 	xerrx(1, "%s", msg);
    635        1.1       cgd }
    636        1.1       cgd 
    637        1.1       cgd static Obj_Entry *
    638       1.98     skrll _rtld_dlcheck(void *handle)
    639        1.1       cgd {
    640       1.15  christos 	Obj_Entry *obj;
    641        1.1       cgd 
    642       1.15  christos 	for (obj = _rtld_objlist; obj != NULL; obj = obj->next)
    643       1.15  christos 		if (obj == (Obj_Entry *) handle)
    644       1.15  christos 			break;
    645       1.15  christos 
    646       1.15  christos 	if (obj == NULL || obj->dl_refcount == 0) {
    647       1.15  christos 		xwarnx("Invalid shared object handle %p", handle);
    648       1.15  christos 		return NULL;
    649       1.15  christos 	}
    650       1.15  christos 	return obj;
    651        1.1       cgd }
    652        1.1       cgd 
    653        1.1       cgd static void
    654      1.117        ad _rtld_initlist_visit(Objlist* list, Obj_Entry *obj, int rev)
    655      1.117        ad {
    656      1.117        ad 	Needed_Entry* elm;
    657      1.117        ad 
    658      1.117        ad 	/* dbg(("_rtld_initlist_visit(%s)", obj->path)); */
    659      1.117        ad 
    660      1.117        ad 	if (obj->init_done)
    661      1.117        ad 		return;
    662      1.117        ad 	obj->init_done = 1;
    663      1.117        ad 
    664      1.117        ad 	for (elm = obj->needed; elm != NULL; elm = elm->next) {
    665      1.117        ad 		if (elm->obj != NULL) {
    666      1.117        ad 			_rtld_initlist_visit(list, elm->obj, rev);
    667      1.117        ad 		}
    668      1.117        ad 	}
    669      1.117        ad 
    670      1.117        ad 	if (rev) {
    671      1.117        ad 		_rtld_objlist_push_head(list, obj);
    672      1.117        ad 	} else {
    673      1.117        ad 		_rtld_objlist_push_tail(list, obj);
    674      1.117        ad 	}
    675      1.117        ad }
    676      1.117        ad 
    677      1.117        ad static void
    678      1.117        ad _rtld_initlist_tsort(Objlist* list, int rev)
    679      1.117        ad {
    680      1.117        ad 	dbg(("_rtld_initlist_tsort"));
    681      1.117        ad 
    682      1.117        ad 	Obj_Entry* obj;
    683      1.117        ad 
    684      1.117        ad 	for (obj = _rtld_objlist->next; obj; obj = obj->next) {
    685      1.117        ad 		obj->init_done = 0;
    686      1.117        ad 	}
    687      1.117        ad 
    688      1.117        ad 	for (obj = _rtld_objlist->next; obj; obj = obj->next) {
    689      1.117        ad 		_rtld_initlist_visit(list, obj, rev);
    690      1.117        ad 	}
    691      1.117        ad }
    692      1.117        ad 
    693      1.117        ad static void
    694       1.98     skrll _rtld_init_dag(Obj_Entry *root)
    695       1.25   mycroft {
    696       1.94    simonb 
    697       1.25   mycroft 	_rtld_init_dag1(root, root);
    698       1.25   mycroft }
    699       1.25   mycroft 
    700       1.25   mycroft static void
    701       1.98     skrll _rtld_init_dag1(Obj_Entry *root, Obj_Entry *obj)
    702       1.25   mycroft {
    703       1.25   mycroft 	const Needed_Entry *needed;
    704       1.25   mycroft 
    705       1.84   mycroft 	if (!obj->mainref) {
    706       1.84   mycroft 		if (_rtld_objlist_find(&obj->dldags, root))
    707       1.84   mycroft 			return;
    708      1.133     skrll 		dbg(("add %p (%s) to %p (%s) DAG", obj, obj->path, root,
    709       1.84   mycroft 		    root->path));
    710      1.117        ad 		_rtld_objlist_push_tail(&obj->dldags, root);
    711      1.117        ad 		_rtld_objlist_push_tail(&root->dagmembers, obj);
    712       1.84   mycroft 	}
    713       1.25   mycroft 	for (needed = obj->needed; needed != NULL; needed = needed->next)
    714       1.25   mycroft 		if (needed->obj != NULL)
    715       1.25   mycroft 			_rtld_init_dag1(root, needed->obj);
    716       1.25   mycroft }
    717       1.25   mycroft 
    718       1.25   mycroft /*
    719       1.25   mycroft  * Note, this is called only for objects loaded by dlopen().
    720       1.25   mycroft  */
    721       1.25   mycroft static void
    722       1.98     skrll _rtld_unload_object(Obj_Entry *root, bool do_fini_funcs)
    723       1.25   mycroft {
    724       1.94    simonb 
    725       1.25   mycroft 	_rtld_unref_dag(root);
    726       1.25   mycroft 	if (root->refcount == 0) { /* We are finished with some objects. */
    727       1.25   mycroft 		Obj_Entry *obj;
    728       1.25   mycroft 		Obj_Entry **linkp;
    729       1.25   mycroft 		Objlist_Entry *elm;
    730       1.25   mycroft 
    731       1.25   mycroft 		/* Finalize objects that are about to be unmapped. */
    732       1.25   mycroft 		if (do_fini_funcs)
    733      1.117        ad 			_rtld_call_fini_functions(0);
    734       1.25   mycroft 
    735       1.25   mycroft 		/* Remove the DAG from all objects' DAG lists. */
    736       1.50     lukem 		SIMPLEQ_FOREACH(elm, &root->dagmembers, link)
    737       1.25   mycroft 			_rtld_objlist_remove(&elm->obj->dldags, root);
    738       1.25   mycroft 
    739       1.25   mycroft 		/* Remove the DAG from the RTLD_GLOBAL list. */
    740       1.84   mycroft 		if (root->globalref) {
    741       1.84   mycroft 			root->globalref = 0;
    742       1.84   mycroft 			_rtld_objlist_remove(&_rtld_list_global, root);
    743       1.84   mycroft 		}
    744       1.25   mycroft 
    745       1.25   mycroft 		/* Unmap all objects that are no longer referenced. */
    746       1.25   mycroft 		linkp = &_rtld_objlist->next;
    747       1.25   mycroft 		while ((obj = *linkp) != NULL) {
    748       1.25   mycroft 			if (obj->refcount == 0) {
    749       1.25   mycroft 				dbg(("unloading \"%s\"", obj->path));
    750      1.118        ad 				if (obj->ehdr != MAP_FAILED)
    751      1.118        ad 					munmap(obj->ehdr, _rtld_pagesz);
    752       1.25   mycroft 				munmap(obj->mapbase, obj->mapsize);
    753       1.45  christos 				_rtld_objlist_remove(&_rtld_list_global, obj);
    754       1.25   mycroft 				_rtld_linkmap_delete(obj);
    755       1.25   mycroft 				*linkp = obj->next;
    756      1.129       roy 				_rtld_objcount--;
    757       1.25   mycroft 				_rtld_obj_free(obj);
    758       1.25   mycroft 			} else
    759       1.25   mycroft 				linkp = &obj->next;
    760       1.25   mycroft 		}
    761       1.25   mycroft 		_rtld_objtail = linkp;
    762       1.25   mycroft 	}
    763       1.25   mycroft }
    764       1.25   mycroft 
    765      1.137     skrll void
    766      1.137     skrll _rtld_ref_dag(Obj_Entry *root)
    767      1.137     skrll {
    768      1.137     skrll 	const Needed_Entry *needed;
    769      1.137     skrll 
    770      1.137     skrll 	assert(root);
    771      1.137     skrll 
    772      1.137     skrll 	++root->refcount;
    773      1.137     skrll 
    774      1.137     skrll 	dbg(("incremented reference on \"%s\" (%d)", root->path,
    775      1.137     skrll 	    root->refcount));
    776      1.137     skrll 	for (needed = root->needed; needed != NULL;
    777      1.137     skrll 	     needed = needed->next) {
    778      1.137     skrll 		if (needed->obj != NULL)
    779      1.137     skrll 			_rtld_ref_dag(needed->obj);
    780      1.137     skrll 	}
    781      1.137     skrll }
    782      1.137     skrll 
    783       1.25   mycroft static void
    784       1.98     skrll _rtld_unref_dag(Obj_Entry *root)
    785        1.1       cgd {
    786       1.94    simonb 
    787       1.33  jdolecek 	assert(root);
    788       1.15  christos 	assert(root->refcount != 0);
    789      1.137     skrll 
    790       1.15  christos 	--root->refcount;
    791      1.137     skrll 	dbg(("decremented reference on \"%s\" (%d)", root->path,
    792      1.137     skrll 	    root->refcount));
    793      1.137     skrll 
    794       1.15  christos 	if (root->refcount == 0) {
    795       1.15  christos 		const Needed_Entry *needed;
    796       1.15  christos 
    797       1.15  christos 		for (needed = root->needed; needed != NULL;
    798       1.32  jdolecek 		     needed = needed->next) {
    799       1.32  jdolecek 			if (needed->obj != NULL)
    800       1.32  jdolecek 				_rtld_unref_dag(needed->obj);
    801       1.32  jdolecek 		}
    802       1.15  christos 	}
    803        1.1       cgd }
    804        1.1       cgd 
    805      1.106   thorpej __strong_alias(__dlclose,dlclose)
    806        1.1       cgd int
    807       1.99     skrll dlclose(void *handle)
    808        1.1       cgd {
    809       1.15  christos 	Obj_Entry *root = _rtld_dlcheck(handle);
    810        1.1       cgd 
    811       1.15  christos 	if (root == NULL)
    812       1.15  christos 		return -1;
    813        1.1       cgd 
    814       1.15  christos 	_rtld_debug.r_state = RT_DELETE;
    815       1.15  christos 	_rtld_debug_state();
    816       1.15  christos 
    817       1.15  christos 	--root->dl_refcount;
    818       1.29    kleink 	_rtld_unload_object(root, true);
    819       1.15  christos 
    820       1.15  christos 	_rtld_debug.r_state = RT_CONSISTENT;
    821       1.15  christos 	_rtld_debug_state();
    822        1.1       cgd 
    823       1.15  christos 	return 0;
    824        1.1       cgd }
    825        1.1       cgd 
    826      1.106   thorpej __strong_alias(__dlerror,dlerror)
    827        1.1       cgd char *
    828       1.99     skrll dlerror(void)
    829        1.1       cgd {
    830       1.15  christos 	char *msg = error_message;
    831       1.94    simonb 
    832       1.15  christos 	error_message = NULL;
    833       1.15  christos 	return msg;
    834        1.1       cgd }
    835        1.1       cgd 
    836      1.106   thorpej __strong_alias(__dlopen,dlopen)
    837        1.1       cgd void *
    838       1.99     skrll dlopen(const char *name, int mode)
    839       1.15  christos {
    840       1.15  christos 	Obj_Entry **old_obj_tail = _rtld_objtail;
    841       1.15  christos 	Obj_Entry *obj = NULL;
    842      1.137     skrll 	int flags = _RTLD_DLOPEN;
    843      1.137     skrll 	bool nodelete;
    844      1.137     skrll 	bool now;
    845      1.137     skrll 
    846      1.137     skrll 	flags |= (mode & RTLD_GLOBAL) ? _RTLD_GLOBAL : 0;
    847      1.137     skrll 	flags |= (mode & RTLD_NOLOAD) ? _RTLD_NOLOAD : 0;
    848      1.137     skrll 
    849      1.137     skrll 	nodelete = (mode & RTLD_NODELETE) ? true : false;
    850      1.137     skrll 	now = ((mode & RTLD_MODEMASK) == RTLD_NOW) ? true : false;
    851       1.15  christos 
    852       1.15  christos 	_rtld_debug.r_state = RT_ADD;
    853       1.15  christos 	_rtld_debug_state();
    854       1.15  christos 
    855       1.15  christos 	if (name == NULL) {
    856       1.15  christos 		obj = _rtld_objmain;
    857       1.25   mycroft 		obj->refcount++;
    858       1.67   mycroft 	} else
    859      1.137     skrll 		obj = _rtld_load_library(name, _rtld_objmain, flags);
    860      1.137     skrll 
    861        1.1       cgd 
    862       1.15  christos 	if (obj != NULL) {
    863       1.15  christos 		++obj->dl_refcount;
    864       1.15  christos 		if (*old_obj_tail != NULL) {	/* We loaded something new. */
    865       1.15  christos 			assert(*old_obj_tail == obj);
    866       1.15  christos 
    867      1.137     skrll 			if (_rtld_load_needed_objects(obj, flags) == -1 ||
    868       1.28  christos 			    (_rtld_init_dag(obj),
    869       1.28  christos 			    _rtld_relocate_objects(obj,
    870      1.137     skrll 			    (now || obj->z_now))) == -1) {
    871       1.25   mycroft 				_rtld_unload_object(obj, false);
    872       1.25   mycroft 				obj->dl_refcount--;
    873       1.15  christos 				obj = NULL;
    874      1.117        ad 			} else {
    875      1.117        ad 				_rtld_call_init_functions();
    876      1.117        ad 			}
    877       1.15  christos 		}
    878      1.137     skrll 		if (obj != NULL) {
    879      1.137     skrll 			if ((nodelete || obj->z_nodelete) && !obj->ref_nodel) {
    880      1.137     skrll 				dbg(("dlopen obj %s nodelete", obj->path));
    881      1.137     skrll 				_rtld_ref_dag(obj);
    882      1.137     skrll 				obj->z_nodelete = obj->ref_nodel = true;
    883      1.137     skrll 			}
    884      1.137     skrll 		}
    885       1.15  christos 	}
    886       1.15  christos 	_rtld_debug.r_state = RT_CONSISTENT;
    887       1.15  christos 	_rtld_debug_state();
    888        1.1       cgd 
    889       1.15  christos 	return obj;
    890       1.31       erh }
    891       1.31       erh 
    892       1.31       erh /*
    893       1.31       erh  * Find a symbol in the main program.
    894       1.31       erh  */
    895       1.31       erh void *
    896       1.98     skrll _rtld_objmain_sym(const char *name)
    897       1.31       erh {
    898       1.31       erh 	unsigned long hash;
    899       1.31       erh 	const Elf_Sym *def;
    900       1.31       erh 	const Obj_Entry *obj;
    901      1.129       roy 	DoneList donelist;
    902       1.31       erh 
    903       1.31       erh 	hash = _rtld_elf_hash(name);
    904       1.31       erh 	obj = _rtld_objmain;
    905      1.129       roy 	_rtld_donelist_init(&donelist);
    906       1.31       erh 
    907      1.129       roy 	def = _rtld_symlook_list(name, hash, &_rtld_list_main, &obj, false,
    908      1.129       roy 	    &donelist);
    909      1.129       roy 
    910       1.31       erh 	if (def != NULL)
    911       1.31       erh 		return obj->relocbase + def->st_value;
    912      1.136     skrll 	return NULL;
    913        1.1       cgd }
    914        1.1       cgd 
    915      1.121  macallan #ifdef __powerpc__
    916      1.121  macallan static void *
    917      1.121  macallan hackish_return_address(void)
    918      1.121  macallan {
    919      1.121  macallan 	return __builtin_return_address(1);
    920      1.121  macallan }
    921      1.121  macallan #endif
    922      1.121  macallan 
    923      1.106   thorpej __strong_alias(__dlsym,dlsym)
    924        1.1       cgd void *
    925       1.99     skrll dlsym(void *handle, const char *name)
    926       1.15  christos {
    927       1.25   mycroft 	const Obj_Entry *obj;
    928       1.92   mycroft 	unsigned long hash;
    929       1.25   mycroft 	const Elf_Sym *def;
    930       1.15  christos 	const Obj_Entry *defobj;
    931       1.93  christos 	void *retaddr;
    932      1.129       roy 	DoneList donelist;
    933       1.25   mycroft 
    934       1.92   mycroft 	hash = _rtld_elf_hash(name);
    935       1.92   mycroft 	def = NULL;
    936       1.92   mycroft 	defobj = NULL;
    937       1.92   mycroft 
    938       1.93  christos 	switch ((intptr_t)handle) {
    939       1.93  christos 	case (intptr_t)NULL:
    940       1.93  christos 	case (intptr_t)RTLD_NEXT:
    941       1.93  christos 	case (intptr_t)RTLD_DEFAULT:
    942       1.93  christos 	case (intptr_t)RTLD_SELF:
    943      1.121  macallan #ifdef __powerpc__
    944      1.121  macallan 		retaddr = hackish_return_address();
    945      1.121  macallan #else
    946      1.121  macallan 		retaddr = __builtin_return_address(0);
    947      1.121  macallan #endif
    948       1.30  christos 		if ((obj = _rtld_obj_from_addr(retaddr)) == NULL) {
    949       1.30  christos 			_rtld_error("Cannot determine caller's shared object");
    950       1.30  christos 			return NULL;
    951       1.30  christos 		}
    952       1.93  christos 
    953       1.93  christos 		switch ((intptr_t)handle) {
    954       1.93  christos 		case (intptr_t)NULL:	 /* Just the caller's shared object. */
    955       1.92   mycroft 			def = _rtld_symlook_obj(name, hash, obj, false);
    956       1.92   mycroft 			defobj = obj;
    957       1.93  christos 			break;
    958       1.93  christos 
    959       1.93  christos 		case (intptr_t)RTLD_NEXT:	/* Objects after callers */
    960       1.93  christos 			obj = obj->next;
    961       1.93  christos 			/*FALLTHROUGH*/
    962       1.93  christos 
    963       1.93  christos 		case (intptr_t)RTLD_SELF:	/* Caller included */
    964       1.93  christos 			for (; obj; obj = obj->next) {
    965       1.93  christos 				if ((def = _rtld_symlook_obj(name, hash, obj,
    966       1.93  christos 				    false)) != NULL) {
    967       1.92   mycroft 					defobj = obj;
    968       1.92   mycroft 					break;
    969       1.92   mycroft 				}
    970       1.92   mycroft 			}
    971       1.93  christos 			break;
    972       1.93  christos 
    973       1.93  christos 		case (intptr_t)RTLD_DEFAULT:
    974       1.93  christos 			def = _rtld_symlook_default(name, hash, obj, &defobj,
    975       1.96     skrll 			    false);
    976       1.93  christos 			break;
    977       1.93  christos 
    978       1.93  christos 		default:
    979       1.93  christos 			abort();
    980       1.92   mycroft 		}
    981       1.93  christos 		break;
    982       1.93  christos 
    983       1.93  christos 	default:
    984       1.92   mycroft 		if ((obj = _rtld_dlcheck(handle)) == NULL)
    985       1.30  christos 			return NULL;
    986       1.92   mycroft 
    987      1.129       roy 		_rtld_donelist_init(&donelist);
    988      1.129       roy 
    989       1.92   mycroft 		if (obj->mainprog) {
    990       1.93  christos 			/* Search main program and all libraries loaded by it */
    991       1.93  christos 			def = _rtld_symlook_list(name, hash, &_rtld_list_main,
    992      1.129       roy 			    &defobj, false, &donelist);
    993       1.92   mycroft 		} else {
    994      1.122     skrll 			Needed_Entry fake;
    995      1.129       roy 			DoneList depth;
    996      1.122     skrll 
    997      1.122     skrll 			/* Search the object and all the libraries loaded by it. */
    998      1.122     skrll 			fake.next = NULL;
    999      1.124  christos 			fake.obj = __UNCONST(obj);
   1000      1.122     skrll 			fake.name = 0;
   1001      1.129       roy 
   1002      1.129       roy 			_rtld_donelist_init(&depth);
   1003      1.122     skrll 			def = _rtld_symlook_needed(name, hash, &fake, &defobj,
   1004      1.129       roy 			    false, &donelist, &depth);
   1005       1.25   mycroft 		}
   1006      1.129       roy 
   1007       1.93  christos 		break;
   1008       1.30  christos 	}
   1009       1.30  christos 
   1010       1.51  fredette 	if (def != NULL) {
   1011       1.51  fredette #ifdef __HAVE_FUNCTION_DESCRIPTORS
   1012       1.51  fredette 		if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
   1013       1.51  fredette 			return (void *)_rtld_function_descriptor_alloc(defobj,
   1014       1.51  fredette 			    def, 0);
   1015       1.51  fredette #endif /* __HAVE_FUNCTION_DESCRIPTORS */
   1016       1.30  christos 		return defobj->relocbase + def->st_value;
   1017       1.51  fredette 	}
   1018       1.92   mycroft 
   1019      1.101   mycroft 	_rtld_error("Undefined symbol \"%s\"", name);
   1020       1.92   mycroft 	return NULL;
   1021       1.25   mycroft }
   1022        1.1       cgd 
   1023      1.106   thorpej __strong_alias(__dladdr,dladdr)
   1024       1.25   mycroft int
   1025       1.99     skrll dladdr(const void *addr, Dl_info *info)
   1026       1.25   mycroft {
   1027       1.25   mycroft 	const Obj_Entry *obj;
   1028       1.51  fredette 	const Elf_Sym *def, *best_def;
   1029       1.25   mycroft 	void *symbol_addr;
   1030       1.25   mycroft 	unsigned long symoffset;
   1031       1.25   mycroft 
   1032       1.51  fredette #ifdef __HAVE_FUNCTION_DESCRIPTORS
   1033       1.51  fredette 	addr = _rtld_function_descriptor_function(addr);
   1034       1.51  fredette #endif /* __HAVE_FUNCTION_DESCRIPTORS */
   1035       1.51  fredette 
   1036       1.25   mycroft 	obj = _rtld_obj_from_addr(addr);
   1037       1.25   mycroft 	if (obj == NULL) {
   1038       1.25   mycroft 		_rtld_error("No shared object contains address");
   1039       1.25   mycroft 		return 0;
   1040       1.25   mycroft 	}
   1041       1.25   mycroft 	info->dli_fname = obj->path;
   1042       1.25   mycroft 	info->dli_fbase = obj->mapbase;
   1043       1.25   mycroft 	info->dli_saddr = (void *)0;
   1044       1.25   mycroft 	info->dli_sname = NULL;
   1045       1.25   mycroft 
   1046       1.15  christos 	/*
   1047       1.25   mycroft 	 * Walk the symbol list looking for the symbol whose address is
   1048       1.25   mycroft 	 * closest to the address sent in.
   1049       1.25   mycroft 	 */
   1050       1.51  fredette 	best_def = NULL;
   1051       1.25   mycroft 	for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
   1052       1.25   mycroft 		def = obj->symtab + symoffset;
   1053       1.25   mycroft 
   1054       1.25   mycroft 		/*
   1055       1.25   mycroft 		 * For skip the symbol if st_shndx is either SHN_UNDEF or
   1056       1.25   mycroft 		 * SHN_COMMON.
   1057       1.25   mycroft 		 */
   1058       1.25   mycroft 		if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
   1059       1.25   mycroft 			continue;
   1060       1.25   mycroft 
   1061       1.25   mycroft 		/*
   1062       1.25   mycroft 		 * If the symbol is greater than the specified address, or if it
   1063       1.25   mycroft 		 * is further away from addr than the current nearest symbol,
   1064       1.25   mycroft 		 * then reject it.
   1065       1.25   mycroft 		 */
   1066       1.25   mycroft 		symbol_addr = obj->relocbase + def->st_value;
   1067       1.25   mycroft 		if (symbol_addr > addr || symbol_addr < info->dli_saddr)
   1068       1.25   mycroft 			continue;
   1069       1.25   mycroft 
   1070       1.25   mycroft 		/* Update our idea of the nearest symbol. */
   1071       1.25   mycroft 		info->dli_sname = obj->strtab + def->st_name;
   1072       1.25   mycroft 		info->dli_saddr = symbol_addr;
   1073       1.51  fredette 		best_def = def;
   1074        1.1       cgd 
   1075       1.25   mycroft 		/* Exact match? */
   1076       1.25   mycroft 		if (info->dli_saddr == addr)
   1077       1.25   mycroft 			break;
   1078       1.25   mycroft 	}
   1079       1.51  fredette 
   1080       1.51  fredette #ifdef __HAVE_FUNCTION_DESCRIPTORS
   1081       1.51  fredette 	if (best_def != NULL && ELF_ST_TYPE(best_def->st_info) == STT_FUNC)
   1082       1.51  fredette 		info->dli_saddr = (void *)_rtld_function_descriptor_alloc(obj,
   1083       1.51  fredette 		    best_def, 0);
   1084       1.51  fredette #endif /* __HAVE_FUNCTION_DESCRIPTORS */
   1085       1.51  fredette 
   1086       1.25   mycroft 	return 1;
   1087        1.1       cgd }
   1088        1.1       cgd 
   1089      1.125     pooka __strong_alias(__dlinfo,dlinfo)
   1090      1.125     pooka int
   1091      1.125     pooka dlinfo(void *handle, int req, void *v)
   1092      1.125     pooka {
   1093      1.125     pooka 	const Obj_Entry *obj;
   1094      1.125     pooka 	void *retaddr;
   1095      1.125     pooka 
   1096      1.125     pooka 	if (handle == RTLD_SELF) {
   1097      1.125     pooka #ifdef __powerpc__
   1098      1.125     pooka 		retaddr = hackish_return_address();
   1099      1.125     pooka #else
   1100      1.125     pooka 		retaddr = __builtin_return_address(0);
   1101      1.125     pooka #endif
   1102      1.125     pooka 		if ((obj = _rtld_obj_from_addr(retaddr)) == NULL) {
   1103      1.125     pooka 			_rtld_error("Cannot determine caller's shared object");
   1104      1.125     pooka 			return -1;
   1105      1.125     pooka 		}
   1106      1.125     pooka 	} else {
   1107      1.125     pooka 		if ((obj = _rtld_dlcheck(handle)) == NULL) {
   1108      1.125     pooka 			_rtld_error("Invalid handle");
   1109      1.125     pooka 			return -1;
   1110      1.125     pooka 		}
   1111      1.125     pooka 	}
   1112      1.125     pooka 
   1113      1.125     pooka 	switch (req) {
   1114      1.125     pooka 	case RTLD_DI_LINKMAP:
   1115      1.125     pooka 		{
   1116      1.125     pooka 		const struct link_map **map = v;
   1117      1.125     pooka 
   1118      1.125     pooka 		*map = &obj->linkmap;
   1119      1.125     pooka 		break;
   1120      1.125     pooka 		}
   1121      1.125     pooka 
   1122      1.125     pooka 	default:
   1123      1.125     pooka 		_rtld_error("Invalid request");
   1124      1.125     pooka 		return -1;
   1125      1.125     pooka 	}
   1126      1.125     pooka 
   1127      1.125     pooka 	return 0;
   1128      1.125     pooka }
   1129      1.125     pooka 
   1130      1.131     skrll __strong_alias(__dl_iterate_phdr,dl_iterate_phdr);
   1131      1.131     skrll int
   1132      1.131     skrll dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *), void *param)
   1133      1.131     skrll {
   1134      1.131     skrll 	struct dl_phdr_info phdr_info;
   1135      1.131     skrll 	const Obj_Entry *obj;
   1136      1.131     skrll 	int error = 0;
   1137      1.131     skrll 
   1138      1.131     skrll 	for (obj = _rtld_objlist;  obj != NULL;  obj = obj->next) {
   1139      1.131     skrll 		phdr_info.dlpi_addr = (Elf_Addr)obj->relocbase;
   1140      1.131     skrll 		phdr_info.dlpi_name = STAILQ_FIRST(&obj->names) ?
   1141      1.131     skrll 		    STAILQ_FIRST(&obj->names)->name : obj->path;
   1142      1.131     skrll 		phdr_info.dlpi_phdr = obj->phdr;
   1143      1.131     skrll 		phdr_info.dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
   1144      1.131     skrll #if 1
   1145      1.131     skrll 		phdr_info.dlpi_tls_modid = 0;
   1146      1.131     skrll 		phdr_info.dlpi_tls_data = 0;
   1147      1.131     skrll #else
   1148      1.131     skrll 		phdr_info.dlpi_tls_modid = obj->tlsindex;
   1149      1.131     skrll 		phdr_info.dlpi_tls_data = obj->tlsinit;
   1150      1.131     skrll #endif
   1151      1.131     skrll 		phdr_info.dlpi_adds = _rtld_objloads;
   1152      1.131     skrll 		phdr_info.dlpi_subs = _rtld_objloads - _rtld_objcount;
   1153      1.131     skrll 
   1154      1.131     skrll 		error = callback(&phdr_info, sizeof(phdr_info), param);
   1155      1.131     skrll 		if (error)
   1156      1.131     skrll 			break;
   1157      1.131     skrll 	}
   1158      1.131     skrll 
   1159      1.131     skrll 	return error;
   1160      1.131     skrll }
   1161      1.131     skrll 
   1162        1.1       cgd /*
   1163        1.1       cgd  * Error reporting function.  Use it like printf.  If formats the message
   1164        1.1       cgd  * into a buffer, and sets things up so that the next call to dlerror()
   1165        1.1       cgd  * will return the message.
   1166        1.1       cgd  */
   1167        1.1       cgd void
   1168       1.15  christos _rtld_error(const char *fmt,...)
   1169        1.1       cgd {
   1170       1.15  christos 	static char     buf[512];
   1171       1.15  christos 	va_list         ap;
   1172       1.49       wiz 
   1173       1.15  christos 	va_start(ap, fmt);
   1174       1.15  christos 	xvsnprintf(buf, sizeof buf, fmt, ap);
   1175       1.15  christos 	error_message = buf;
   1176       1.15  christos 	va_end(ap);
   1177        1.1       cgd }
   1178       1.14        pk 
   1179        1.1       cgd void
   1180       1.98     skrll _rtld_debug_state(void)
   1181        1.1       cgd {
   1182       1.94    simonb 
   1183       1.15  christos 	/* do nothing */
   1184        1.1       cgd }
   1185        1.1       cgd 
   1186        1.1       cgd void
   1187       1.98     skrll _rtld_linkmap_add(Obj_Entry *obj)
   1188        1.1       cgd {
   1189       1.15  christos 	struct link_map *l = &obj->linkmap;
   1190       1.15  christos 	struct link_map *prev;
   1191        1.1       cgd 
   1192       1.15  christos 	obj->linkmap.l_name = obj->path;
   1193       1.68   mycroft 	obj->linkmap.l_addr = obj->relocbase;
   1194       1.15  christos 	obj->linkmap.l_ld = obj->dynamic;
   1195        1.6    mhitch #ifdef __mips__
   1196       1.72   mycroft 	/* XXX This field is not standard and will be removed eventually. */
   1197       1.15  christos 	obj->linkmap.l_offs = obj->relocbase;
   1198        1.6    mhitch #endif
   1199        1.1       cgd 
   1200       1.15  christos 	if (_rtld_debug.r_map == NULL) {
   1201       1.15  christos 		_rtld_debug.r_map = l;
   1202       1.15  christos 		return;
   1203       1.15  christos 	}
   1204      1.109     skrll 
   1205      1.109     skrll 	/*
   1206      1.109     skrll 	 * Scan to the end of the list, but not past the entry for the
   1207      1.109     skrll 	 * dynamic linker, which we want to keep at the very end.
   1208      1.109     skrll 	 */
   1209      1.109     skrll 	for (prev = _rtld_debug.r_map;
   1210      1.109     skrll 	    prev->l_next != NULL && prev->l_next != &_rtld_objself.linkmap;
   1211      1.109     skrll 	    prev = prev->l_next);
   1212      1.109     skrll 
   1213       1.15  christos 	l->l_prev = prev;
   1214      1.109     skrll 	l->l_next = prev->l_next;
   1215      1.109     skrll 	if (l->l_next != NULL)
   1216      1.109     skrll 		l->l_next->l_prev = l;
   1217       1.15  christos 	prev->l_next = l;
   1218        1.1       cgd }
   1219        1.1       cgd 
   1220        1.1       cgd void
   1221       1.98     skrll _rtld_linkmap_delete(Obj_Entry *obj)
   1222        1.1       cgd {
   1223       1.15  christos 	struct link_map *l = &obj->linkmap;
   1224        1.1       cgd 
   1225       1.15  christos 	if (l->l_prev == NULL) {
   1226       1.15  christos 		if ((_rtld_debug.r_map = l->l_next) != NULL)
   1227       1.15  christos 			l->l_next->l_prev = NULL;
   1228       1.15  christos 		return;
   1229       1.15  christos 	}
   1230       1.15  christos 	if ((l->l_prev->l_next = l->l_next) != NULL)
   1231       1.15  christos 		l->l_next->l_prev = l->l_prev;
   1232       1.25   mycroft }
   1233       1.25   mycroft 
   1234       1.25   mycroft static Obj_Entry *
   1235       1.25   mycroft _rtld_obj_from_addr(const void *addr)
   1236       1.25   mycroft {
   1237       1.25   mycroft 	Obj_Entry *obj;
   1238       1.25   mycroft 
   1239       1.25   mycroft 	for (obj = _rtld_objlist;  obj != NULL;  obj = obj->next) {
   1240       1.25   mycroft 		if (addr < (void *) obj->mapbase)
   1241       1.25   mycroft 			continue;
   1242       1.67   mycroft 		if (addr < (void *) (obj->mapbase + obj->mapsize))
   1243       1.25   mycroft 			return obj;
   1244       1.25   mycroft 	}
   1245       1.25   mycroft 	return NULL;
   1246       1.25   mycroft }
   1247       1.25   mycroft 
   1248       1.25   mycroft static void
   1249      1.117        ad _rtld_objlist_clear(Objlist *list)
   1250      1.117        ad {
   1251      1.117        ad 	while (!SIMPLEQ_EMPTY(list)) {
   1252      1.117        ad 		Objlist_Entry* elm = SIMPLEQ_FIRST(list);
   1253      1.117        ad 		SIMPLEQ_REMOVE_HEAD(list, link);
   1254      1.117        ad 		xfree(elm);
   1255      1.117        ad 	}
   1256      1.117        ad }
   1257      1.117        ad 
   1258      1.117        ad static void
   1259       1.98     skrll _rtld_objlist_remove(Objlist *list, Obj_Entry *obj)
   1260       1.25   mycroft {
   1261       1.25   mycroft 	Objlist_Entry *elm;
   1262       1.25   mycroft 
   1263       1.25   mycroft 	if ((elm = _rtld_objlist_find(list, obj)) != NULL) {
   1264       1.50     lukem 		SIMPLEQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
   1265      1.116        ad 		xfree(elm);
   1266       1.25   mycroft 	}
   1267        1.1       cgd }
   1268