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rtld.c revision 1.212.2.4
      1  1.212.2.4       snj /*	$NetBSD: rtld.c,v 1.212.2.4 2024/08/06 15:06:47 snj 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  1.212.2.4       snj __RCSID("$NetBSD: rtld.c,v 1.212.2.4 2024/08/06 15:06:47 snj Exp $");
     44      1.107     skrll #endif /* not lint */
     45      1.107     skrll 
     46      1.141     joerg #include <sys/param.h>
     47      1.141     joerg #include <sys/atomic.h>
     48      1.141     joerg #include <sys/mman.h>
     49        1.1       cgd #include <err.h>
     50        1.1       cgd #include <errno.h>
     51        1.1       cgd #include <fcntl.h>
     52      1.141     joerg #include <lwp.h>
     53        1.1       cgd #include <stdarg.h>
     54        1.1       cgd #include <stdio.h>
     55        1.1       cgd #include <stdlib.h>
     56        1.1       cgd #include <string.h>
     57        1.1       cgd #include <unistd.h>
     58        1.1       cgd #include <dirent.h>
     59        1.1       cgd 
     60        1.1       cgd #include <ctype.h>
     61        1.1       cgd 
     62        1.2       cgd #include <dlfcn.h>
     63  1.212.2.3    martin 
     64        1.1       cgd #include "debug.h"
     65  1.212.2.3    martin #include "hash.h"
     66        1.1       cgd #include "rtld.h"
     67        1.3       cgd 
     68       1.20    kleink #if !defined(lint)
     69        1.3       cgd #include "sysident.h"
     70       1.20    kleink #endif
     71        1.1       cgd 
     72        1.1       cgd /*
     73  1.212.2.4       snj  * Hidden function from common/lib/libc/atomic - nop on machines
     74  1.212.2.4       snj  * with enough atomic ops. Need to explicitly call it early.
     75  1.212.2.4       snj  * libc has the same symbol and will initialize itself, but not our copy.
     76  1.212.2.4       snj  */
     77  1.212.2.4       snj void __libc_atomic_init(void);
     78  1.212.2.4       snj 
     79  1.212.2.4       snj /*
     80        1.1       cgd  * Function declarations.
     81        1.1       cgd  */
     82      1.113  christos static void     _rtld_init(caddr_t, caddr_t, const char *);
     83       1.98     skrll static void     _rtld_exit(void);
     84       1.15  christos 
     85       1.98     skrll Elf_Addr        _rtld(Elf_Addr *, Elf_Addr);
     86       1.15  christos 
     87        1.1       cgd 
     88        1.1       cgd /*
     89        1.1       cgd  * Data declarations.
     90        1.1       cgd  */
     91       1.15  christos static char    *error_message;	/* Message for dlopen(), or NULL */
     92        1.1       cgd 
     93      1.206     kamil struct r_debug  _rtld_debug;	/* The SVR4 interface for the debugger */
     94       1.15  christos bool            _rtld_trust;	/* False for setuid and setgid programs */
     95       1.15  christos Obj_Entry      *_rtld_objlist;	/* Head of linked list of shared objects */
     96       1.15  christos Obj_Entry     **_rtld_objtail;	/* Link field of last object in list */
     97       1.15  christos Obj_Entry      *_rtld_objmain;	/* The main program shared object */
     98       1.15  christos Obj_Entry       _rtld_objself;	/* The dynamic linker shared object */
     99      1.131     skrll u_int		_rtld_objcount;	/* Number of objects in _rtld_objlist */
    100      1.131     skrll u_int		_rtld_objloads;	/* Number of objects loaded in _rtld_objlist */
    101      1.147     joerg u_int		_rtld_objgen;	/* Generation count for _rtld_objlist */
    102      1.120      matt const char	_rtld_path[] = _PATH_RTLD;
    103      1.120      matt 
    104      1.120      matt /* Initialize a fake symbol for resolving undefined weak references. */
    105      1.120      matt Elf_Sym		_rtld_sym_zero = {
    106      1.120      matt     .st_info	= ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE),
    107      1.120      matt     .st_shndx	= SHN_ABS,
    108      1.120      matt };
    109      1.126     skrll size_t	_rtld_pagesz;	/* Page size, as provided by kernel */
    110       1.25   mycroft 
    111       1.22    kleink Search_Path    *_rtld_default_paths;
    112       1.15  christos Search_Path    *_rtld_paths;
    113       1.28  christos 
    114       1.28  christos Library_Xform  *_rtld_xforms;
    115      1.156     joerg static void    *auxinfo;
    116       1.28  christos 
    117        1.1       cgd /*
    118        1.1       cgd  * Global declarations normally provided by crt0.
    119        1.1       cgd  */
    120       1.15  christos char           *__progname;
    121       1.15  christos char          **environ;
    122        1.1       cgd 
    123      1.141     joerg static volatile bool _rtld_mutex_may_recurse;
    124      1.141     joerg 
    125      1.108       uwe #if defined(RTLD_DEBUG)
    126      1.112       scw #ifndef __sh__
    127        1.9        tv extern Elf_Addr _GLOBAL_OFFSET_TABLE_[];
    128      1.108       uwe #else  /* 32-bit SuperH */
    129      1.108       uwe register Elf_Addr *_GLOBAL_OFFSET_TABLE_ asm("r12");
    130      1.108       uwe #endif
    131      1.108       uwe #endif /* RTLD_DEBUG */
    132       1.15  christos extern Elf_Dyn  _DYNAMIC;
    133        1.8        tv 
    134      1.148     joerg static void _rtld_call_fini_functions(sigset_t *, int);
    135      1.148     joerg static void _rtld_call_init_functions(sigset_t *);
    136      1.117        ad static void _rtld_initlist_visit(Objlist *, Obj_Entry *, int);
    137      1.117        ad static void _rtld_initlist_tsort(Objlist *, int);
    138       1.98     skrll static Obj_Entry *_rtld_dlcheck(void *);
    139       1.98     skrll static void _rtld_init_dag(Obj_Entry *);
    140       1.98     skrll static void _rtld_init_dag1(Obj_Entry *, Obj_Entry *);
    141       1.98     skrll static void _rtld_objlist_remove(Objlist *, Obj_Entry *);
    142      1.117        ad static void _rtld_objlist_clear(Objlist *);
    143      1.148     joerg static void _rtld_unload_object(sigset_t *, Obj_Entry *, bool);
    144       1.98     skrll static void _rtld_unref_dag(Obj_Entry *);
    145       1.98     skrll static Obj_Entry *_rtld_obj_from_addr(const void *);
    146      1.198     kamil static void _rtld_fill_dl_phdr_info(const Obj_Entry *, struct dl_phdr_info *);
    147       1.15  christos 
    148      1.158      matt static inline void
    149      1.210     skrll _rtld_call_initfini_function(fptr_t func, sigset_t *mask)
    150      1.158      matt {
    151      1.158      matt 	_rtld_exclusive_exit(mask);
    152      1.210     skrll 	(*func)();
    153      1.158      matt 	_rtld_exclusive_enter(mask);
    154      1.158      matt }
    155      1.158      matt 
    156      1.158      matt static void
    157      1.158      matt _rtld_call_fini_function(Obj_Entry *obj, sigset_t *mask, u_int cur_objgen)
    158      1.158      matt {
    159      1.210     skrll 	if (obj->fini_arraysz == 0 && (obj->fini == NULL || obj->fini_called))
    160      1.174     joerg 		return;
    161      1.174     joerg 
    162      1.210     skrll 	if (obj->fini != NULL && !obj->fini_called) {
    163      1.158      matt 		dbg (("calling fini function %s at %p%s", obj->path,
    164      1.158      matt 		    (void *)obj->fini,
    165      1.158      matt 		    obj->z_initfirst ? " (DF_1_INITFIRST)" : ""));
    166      1.165     skrll 		obj->fini_called = 1;
    167      1.210     skrll 		_rtld_call_initfini_function(obj->fini, mask);
    168      1.158      matt 	}
    169      1.158      matt #ifdef HAVE_INITFINI_ARRAY
    170      1.158      matt 	/*
    171      1.158      matt 	 * Now process the fini_array if it exists.  Simply go from
    172      1.158      matt 	 * start to end.  We need to make restartable so just advance
    173      1.158      matt 	 * the array pointer and decrement the size each time through
    174      1.158      matt 	 * the loop.
    175      1.158      matt 	 */
    176      1.158      matt 	while (obj->fini_arraysz > 0 && _rtld_objgen == cur_objgen) {
    177      1.210     skrll 		fptr_t fini = *obj->fini_array++;
    178      1.158      matt 		obj->fini_arraysz--;
    179      1.158      matt 		dbg (("calling fini array function %s at %p%s", obj->path,
    180      1.158      matt 		    (void *)fini,
    181      1.158      matt 		    obj->z_initfirst ? " (DF_1_INITFIRST)" : ""));
    182      1.210     skrll 		_rtld_call_initfini_function(fini, mask);
    183      1.158      matt 	}
    184      1.158      matt #endif /* HAVE_INITFINI_ARRAY */
    185      1.158      matt }
    186      1.158      matt 
    187        1.1       cgd static void
    188      1.148     joerg _rtld_call_fini_functions(sigset_t *mask, int force)
    189        1.1       cgd {
    190      1.117        ad 	Objlist_Entry *elm;
    191      1.117        ad 	Objlist finilist;
    192      1.147     joerg 	u_int cur_objgen;
    193        1.1       cgd 
    194      1.117        ad 	dbg(("_rtld_call_fini_functions(%d)", force));
    195      1.117        ad 
    196      1.147     joerg restart:
    197      1.147     joerg 	cur_objgen = ++_rtld_objgen;
    198      1.117        ad 	SIMPLEQ_INIT(&finilist);
    199      1.117        ad 	_rtld_initlist_tsort(&finilist, 1);
    200      1.117        ad 
    201      1.117        ad 	/* First pass: objects _not_ marked with DF_1_INITFIRST. */
    202      1.117        ad 	SIMPLEQ_FOREACH(elm, &finilist, link) {
    203      1.158      matt 		Obj_Entry * const obj = elm->obj;
    204      1.158      matt 		if (!obj->z_initfirst) {
    205      1.158      matt 			if (obj->refcount > 0 && !force) {
    206      1.158      matt 				continue;
    207      1.158      matt 			}
    208      1.158      matt 			/*
    209      1.158      matt 			 * XXX This can race against a concurrent dlclose().
    210      1.158      matt 			 * XXX In that case, the object could be unmapped before
    211      1.158      matt 			 * XXX the fini() call or the fini_array has completed.
    212      1.158      matt 			 */
    213      1.158      matt 			_rtld_call_fini_function(obj, mask, cur_objgen);
    214      1.158      matt 			if (_rtld_objgen != cur_objgen) {
    215      1.158      matt 				dbg(("restarting fini iteration"));
    216      1.158      matt 				_rtld_objlist_clear(&finilist);
    217      1.158      matt 				goto restart;
    218      1.117        ad 		}
    219      1.147     joerg 		}
    220      1.117        ad 	}
    221      1.117        ad 
    222      1.117        ad 	/* Second pass: objects marked with DF_1_INITFIRST. */
    223      1.117        ad 	SIMPLEQ_FOREACH(elm, &finilist, link) {
    224      1.158      matt 		Obj_Entry * const obj = elm->obj;
    225      1.117        ad 		if (obj->refcount > 0 && !force) {
    226      1.117        ad 			continue;
    227      1.117        ad 		}
    228      1.147     joerg 		/* XXX See above for the race condition here */
    229      1.158      matt 		_rtld_call_fini_function(obj, mask, cur_objgen);
    230      1.147     joerg 		if (_rtld_objgen != cur_objgen) {
    231      1.147     joerg 			dbg(("restarting fini iteration"));
    232      1.147     joerg 			_rtld_objlist_clear(&finilist);
    233      1.147     joerg 			goto restart;
    234      1.147     joerg 		}
    235      1.117        ad 	}
    236      1.117        ad 
    237      1.117        ad         _rtld_objlist_clear(&finilist);
    238        1.1       cgd }
    239        1.1       cgd 
    240        1.1       cgd static void
    241      1.158      matt _rtld_call_init_function(Obj_Entry *obj, sigset_t *mask, u_int cur_objgen)
    242      1.158      matt {
    243      1.210     skrll 	if (obj->init_arraysz == 0 && (obj->init_called || obj->init == NULL))
    244      1.158      matt 		return;
    245      1.174     joerg 
    246      1.210     skrll 	if (!obj->init_called && obj->init != NULL) {
    247      1.158      matt 		dbg (("calling init function %s at %p%s",
    248      1.158      matt 		    obj->path, (void *)obj->init,
    249      1.158      matt 		    obj->z_initfirst ? " (DF_1_INITFIRST)" : ""));
    250      1.158      matt 		obj->init_called = 1;
    251      1.210     skrll 		_rtld_call_initfini_function(obj->init, mask);
    252      1.158      matt 	}
    253      1.158      matt 
    254      1.158      matt #ifdef HAVE_INITFINI_ARRAY
    255      1.158      matt 	/*
    256      1.158      matt 	 * Now process the init_array if it exists.  Simply go from
    257      1.158      matt 	 * start to end.  We need to make restartable so just advance
    258      1.158      matt 	 * the array pointer and decrement the size each time through
    259      1.158      matt 	 * the loop.
    260      1.158      matt 	 */
    261      1.158      matt 	while (obj->init_arraysz > 0 && _rtld_objgen == cur_objgen) {
    262      1.210     skrll 		fptr_t init = *obj->init_array++;
    263      1.158      matt 		obj->init_arraysz--;
    264      1.158      matt 		dbg (("calling init_array function %s at %p%s",
    265      1.158      matt 		    obj->path, (void *)init,
    266      1.158      matt 		    obj->z_initfirst ? " (DF_1_INITFIRST)" : ""));
    267      1.210     skrll 		_rtld_call_initfini_function(init, mask);
    268      1.158      matt 	}
    269      1.158      matt #endif /* HAVE_INITFINI_ARRAY */
    270      1.158      matt }
    271      1.158      matt 
    272      1.188     joerg static bool
    273      1.188     joerg _rtld_call_ifunc_functions(sigset_t *mask, Obj_Entry *obj, u_int cur_objgen)
    274      1.188     joerg {
    275      1.188     joerg 	if (obj->ifunc_remaining
    276      1.192     joerg #if defined(IFUNC_NONPLT)
    277      1.188     joerg 	    || obj->ifunc_remaining_nonplt
    278      1.188     joerg #endif
    279      1.188     joerg 	) {
    280      1.188     joerg 		_rtld_call_ifunc(obj, mask, cur_objgen);
    281      1.188     joerg 		if (_rtld_objgen != cur_objgen) {
    282      1.188     joerg 			return true;
    283      1.188     joerg 		}
    284      1.188     joerg 	}
    285      1.188     joerg 	return false;
    286      1.188     joerg }
    287      1.188     joerg 
    288      1.158      matt static void
    289      1.148     joerg _rtld_call_init_functions(sigset_t *mask)
    290        1.1       cgd {
    291      1.117        ad 	Objlist_Entry *elm;
    292      1.117        ad 	Objlist initlist;
    293      1.147     joerg 	u_int cur_objgen;
    294       1.94    simonb 
    295      1.117        ad 	dbg(("_rtld_call_init_functions()"));
    296      1.147     joerg 
    297      1.147     joerg restart:
    298      1.147     joerg 	cur_objgen = ++_rtld_objgen;
    299      1.117        ad 	SIMPLEQ_INIT(&initlist);
    300      1.117        ad 	_rtld_initlist_tsort(&initlist, 0);
    301      1.117        ad 
    302      1.186     joerg 	/* First pass: objects with IRELATIVE relocations. */
    303      1.186     joerg 	SIMPLEQ_FOREACH(elm, &initlist, link) {
    304      1.188     joerg 		if (_rtld_call_ifunc_functions(mask, elm->obj, cur_objgen)) {
    305      1.188     joerg 			dbg(("restarting init iteration"));
    306      1.188     joerg 			_rtld_objlist_clear(&initlist);
    307      1.188     joerg 			goto restart;
    308      1.186     joerg 		}
    309      1.186     joerg 	}
    310      1.188     joerg 	/*
    311      1.188     joerg 	 * XXX: For historic reasons, init/fini of the main object are called
    312      1.188     joerg 	 * from crt0. Don't introduce that mistake for ifunc, so look at
    313      1.188     joerg 	 * the head of _rtld_objlist that _rtld_initlist_tsort skipped.
    314      1.188     joerg 	 */
    315      1.188     joerg 	if (_rtld_call_ifunc_functions(mask, _rtld_objlist, cur_objgen)) {
    316      1.188     joerg 		dbg(("restarting init iteration"));
    317      1.188     joerg 		_rtld_objlist_clear(&initlist);
    318      1.188     joerg 		goto restart;
    319      1.188     joerg 	}
    320      1.186     joerg 
    321      1.186     joerg 	/* Second pass: objects marked with DF_1_INITFIRST. */
    322      1.117        ad 	SIMPLEQ_FOREACH(elm, &initlist, link) {
    323      1.158      matt 		Obj_Entry * const obj = elm->obj;
    324      1.158      matt 		if (obj->z_initfirst) {
    325      1.158      matt 			_rtld_call_init_function(obj, mask, cur_objgen);
    326      1.158      matt 			if (_rtld_objgen != cur_objgen) {
    327      1.158      matt 				dbg(("restarting init iteration"));
    328      1.158      matt 				_rtld_objlist_clear(&initlist);
    329      1.158      matt 				goto restart;
    330      1.158      matt 			}
    331      1.147     joerg 		}
    332      1.117        ad 	}
    333      1.117        ad 
    334      1.186     joerg 	/* Third pass: all other objects. */
    335      1.117        ad 	SIMPLEQ_FOREACH(elm, &initlist, link) {
    336      1.158      matt 		_rtld_call_init_function(elm->obj, mask, cur_objgen);
    337      1.147     joerg 		if (_rtld_objgen != cur_objgen) {
    338      1.147     joerg 			dbg(("restarting init iteration"));
    339      1.147     joerg 			_rtld_objlist_clear(&initlist);
    340      1.147     joerg 			goto restart;
    341      1.147     joerg 		}
    342       1.14        pk 	}
    343      1.117        ad 
    344      1.117        ad         _rtld_objlist_clear(&initlist);
    345        1.1       cgd }
    346       1.14        pk 
    347        1.1       cgd /*
    348        1.1       cgd  * Initialize the dynamic linker.  The argument is the address at which
    349        1.1       cgd  * the dynamic linker has been mapped into memory.  The primary task of
    350      1.105     skrll  * this function is to create an Obj_Entry for the dynamic linker and
    351      1.105     skrll  * to resolve the PLT relocation for platforms that need it (those that
    352      1.105     skrll  * define __HAVE_FUNCTION_DESCRIPTORS
    353        1.1       cgd  */
    354        1.1       cgd static void
    355      1.114  christos _rtld_init(caddr_t mapbase, caddr_t relocbase, const char *execname)
    356        1.1       cgd {
    357      1.198     kamil 	const Elf_Ehdr *ehdr;
    358       1.94    simonb 
    359       1.14        pk 	/* Conjure up an Obj_Entry structure for the dynamic linker. */
    360      1.120      matt 	_rtld_objself.path = __UNCONST(_rtld_path);
    361      1.120      matt 	_rtld_objself.pathlen = sizeof(_rtld_path)-1;
    362       1.80   mycroft 	_rtld_objself.rtld = true;
    363       1.80   mycroft 	_rtld_objself.mapbase = mapbase;
    364       1.80   mycroft 	_rtld_objself.relocbase = relocbase;
    365       1.80   mycroft 	_rtld_objself.dynamic = (Elf_Dyn *) &_DYNAMIC;
    366      1.119  christos 	_rtld_objself.strtab = "_rtld_sym_zero";
    367        1.1       cgd 
    368      1.120      matt 	/*
    369      1.128     skrll 	 * Set value to -relocbase so that
    370      1.128     skrll 	 *
    371      1.128     skrll 	 *     _rtld_objself.relocbase + _rtld_sym_zero.st_value == 0
    372      1.128     skrll 	 *
    373      1.120      matt 	 * This allows unresolved references to weak symbols to be computed
    374      1.128     skrll 	 * to a value of 0.
    375      1.120      matt 	 */
    376      1.120      matt 	_rtld_sym_zero.st_value = -(uintptr_t)relocbase;
    377      1.120      matt 
    378      1.113  christos 	_rtld_digest_dynamic(_rtld_path, &_rtld_objself);
    379      1.104     skrll 	assert(!_rtld_objself.needed);
    380      1.105     skrll #if !defined(__hppa__)
    381      1.103     skrll 	assert(!_rtld_objself.pltrel && !_rtld_objself.pltrela);
    382      1.105     skrll #else
    383      1.105     skrll 	_rtld_relocate_plt_objects(&_rtld_objself);
    384      1.105     skrll #endif
    385      1.105     skrll #if !defined(__mips__) && !defined(__hppa__)
    386      1.104     skrll 	assert(!_rtld_objself.pltgot);
    387      1.103     skrll #endif
    388       1.97     skrll #if !defined(__arm__) && !defined(__mips__) && !defined(__sh__)
    389       1.97     skrll 	/* ARM, MIPS and SH{3,5} have a bogus DT_TEXTREL. */
    390      1.103     skrll 	assert(!_rtld_objself.textrel);
    391       1.80   mycroft #endif
    392       1.13  christos 
    393      1.114  christos 	_rtld_add_paths(execname, &_rtld_default_paths,
    394      1.114  christos 	    RTLD_DEFAULT_LIBRARY_PATH);
    395       1.13  christos 
    396      1.123       mrg #ifdef RTLD_ARCH_SUBDIR
    397      1.123       mrg 	_rtld_add_paths(execname, &_rtld_default_paths,
    398      1.123       mrg 	    RTLD_DEFAULT_LIBRARY_PATH "/" RTLD_ARCH_SUBDIR);
    399      1.123       mrg #endif
    400      1.123       mrg 
    401      1.169     skrll 	/* Make the object list empty. */
    402       1.14        pk 	_rtld_objlist = NULL;
    403       1.14        pk 	_rtld_objtail = &_rtld_objlist;
    404      1.129       roy 	_rtld_objcount = 0;
    405        1.1       cgd 
    406      1.206     kamil 	_rtld_debug.r_version = R_DEBUG_VERSION;
    407       1.14        pk 	_rtld_debug.r_brk = _rtld_debug_state;
    408       1.14        pk 	_rtld_debug.r_state = RT_CONSISTENT;
    409      1.207     kamil 	_rtld_debug.r_ldbase = _rtld_objself.relocbase;
    410      1.198     kamil 
    411      1.198     kamil 	ehdr = (Elf_Ehdr *)mapbase;
    412      1.198     kamil 	_rtld_objself.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff);
    413      1.198     kamil 	_rtld_objself.phsize = ehdr->e_phnum * sizeof(_rtld_objself.phdr[0]);
    414  1.212.2.4       snj 
    415  1.212.2.4       snj 	__libc_atomic_init();
    416        1.1       cgd }
    417       1.14        pk 
    418        1.1       cgd /*
    419        1.1       cgd  * Cleanup procedure.  It will be called (by the atexit() mechanism) just
    420        1.1       cgd  * before the process exits.
    421        1.1       cgd  */
    422        1.1       cgd static void
    423       1.98     skrll _rtld_exit(void)
    424        1.1       cgd {
    425      1.148     joerg 	sigset_t mask;
    426      1.148     joerg 
    427       1.15  christos 	dbg(("rtld_exit()"));
    428        1.1       cgd 
    429      1.148     joerg 	_rtld_exclusive_enter(&mask);
    430      1.145     joerg 
    431      1.148     joerg 	_rtld_call_fini_functions(&mask, 1);
    432      1.145     joerg 
    433      1.148     joerg 	_rtld_exclusive_exit(&mask);
    434        1.1       cgd }
    435       1.14        pk 
    436      1.156     joerg __dso_public void *
    437      1.156     joerg _dlauxinfo(void)
    438      1.156     joerg {
    439      1.156     joerg 	return auxinfo;
    440      1.156     joerg }
    441      1.156     joerg 
    442        1.1       cgd /*
    443        1.1       cgd  * Main entry point for dynamic linking.  The argument is the stack
    444        1.1       cgd  * pointer.  The stack is expected to be laid out as described in the
    445        1.1       cgd  * SVR4 ABI specification, Intel 386 Processor Supplement.  Specifically,
    446        1.1       cgd  * the stack pointer points to a word containing ARGC.  Following that
    447        1.1       cgd  * in the stack is a null-terminated sequence of pointers to argument
    448        1.1       cgd  * strings.  Then comes a null-terminated sequence of pointers to
    449        1.1       cgd  * environment strings.  Finally, there is a sequence of "auxiliary
    450        1.1       cgd  * vector" entries.
    451        1.1       cgd  *
    452       1.17    kleink  * This function returns the entry point for the main program, the dynamic
    453       1.17    kleink  * linker's exit procedure in sp[0], and a pointer to the main object in
    454       1.17    kleink  * sp[1].
    455        1.1       cgd  */
    456        1.1       cgd Elf_Addr
    457       1.98     skrll _rtld(Elf_Addr *sp, Elf_Addr relocbase)
    458        1.1       cgd {
    459       1.15  christos 	const AuxInfo  *pAUX_base, *pAUX_entry, *pAUX_execfd, *pAUX_phdr,
    460       1.53  christos 	               *pAUX_phent, *pAUX_phnum, *pAUX_euid, *pAUX_egid,
    461       1.53  christos 		       *pAUX_ruid, *pAUX_rgid;
    462       1.18        ws 	const AuxInfo  *pAUX_pagesz;
    463      1.134     joerg 	char          **env, **oenvp;
    464       1.15  christos 	const AuxInfo  *auxp;
    465      1.139     joerg 	Obj_Entry      *obj;
    466       1.39   mycroft 	Elf_Addr       *const osp = sp;
    467       1.15  christos 	bool            bind_now = 0;
    468      1.134     joerg 	const char     *ld_bind_now, *ld_preload, *ld_library_path;
    469       1.15  christos 	const char    **argv;
    470      1.114  christos 	const char     *execname;
    471       1.40   mycroft 	long		argc;
    472       1.31       erh 	const char **real___progname;
    473       1.34  christos 	const Obj_Entry **real___mainprog_obj;
    474       1.31       erh 	char ***real_environ;
    475      1.148     joerg 	sigset_t        mask;
    476      1.134     joerg #ifdef DEBUG
    477      1.138     pooka 	const char     *ld_debug;
    478      1.138     pooka #endif
    479      1.138     pooka #ifdef RTLD_DEBUG
    480      1.117        ad 	int i = 0;
    481       1.12  christos #endif
    482        1.1       cgd 
    483       1.15  christos 	/*
    484       1.15  christos          * On entry, the dynamic linker itself has not been relocated yet.
    485       1.15  christos          * Be very careful not to reference any global data until after
    486       1.15  christos          * _rtld_init has returned.  It is OK to reference file-scope statics
    487       1.15  christos          * and string constants, and to call static and global functions.
    488       1.15  christos          */
    489       1.15  christos 	/* Find the auxiliary vector on the stack. */
    490       1.15  christos 	/* first Elf_Word reserved to address of exit routine */
    491       1.60   mycroft #if defined(RTLD_DEBUG)
    492       1.75   mycroft 	debug = 1;
    493       1.88      fvdl 	dbg(("sp = %p, argc = %ld, argv = %p <%s> relocbase %p", sp,
    494       1.88      fvdl 	    (long)sp[2], &sp[3], (char *) sp[3], (void *)relocbase));
    495      1.164     skrll #ifndef __x86_64__
    496       1.75   mycroft 	dbg(("got is at %p, dynamic is at %p", _GLOBAL_OFFSET_TABLE_,
    497       1.75   mycroft 	    &_DYNAMIC));
    498      1.152  christos #endif
    499      1.162      matt #endif
    500        1.1       cgd 
    501       1.15  christos 	sp += 2;		/* skip over return argument space */
    502       1.15  christos 	argv = (const char **) &sp[1];
    503       1.40   mycroft 	argc = *(long *)sp;
    504       1.39   mycroft 	sp += 2 + argc;		/* Skip over argc, arguments, and NULL
    505       1.15  christos 				 * terminator */
    506       1.15  christos 	env = (char **) sp;
    507       1.15  christos 	while (*sp++ != 0) {	/* Skip over environment, and NULL terminator */
    508       1.60   mycroft #if defined(RTLD_DEBUG)
    509       1.71  junyoung 		dbg(("env[%d] = %p %s", i++, (void *)sp[-1], (char *)sp[-1]));
    510        1.1       cgd #endif
    511       1.15  christos 	}
    512      1.156     joerg 	auxinfo = (AuxInfo *) sp;
    513        1.1       cgd 
    514       1.15  christos 	pAUX_base = pAUX_entry = pAUX_execfd = NULL;
    515       1.15  christos 	pAUX_phdr = pAUX_phent = pAUX_phnum = NULL;
    516       1.53  christos 	pAUX_euid = pAUX_ruid = pAUX_egid = pAUX_rgid = NULL;
    517       1.18        ws 	pAUX_pagesz = NULL;
    518       1.44        pk 
    519      1.114  christos 	execname = NULL;
    520      1.114  christos 
    521       1.69   mycroft 	/* Digest the auxiliary vector. */
    522      1.156     joerg 	for (auxp = auxinfo; auxp->a_type != AT_NULL; ++auxp) {
    523       1.24    kleink 		switch (auxp->a_type) {
    524       1.24    kleink 		case AT_BASE:
    525       1.15  christos 			pAUX_base = auxp;
    526       1.15  christos 			break;
    527       1.24    kleink 		case AT_ENTRY:
    528       1.15  christos 			pAUX_entry = auxp;
    529       1.15  christos 			break;
    530       1.24    kleink 		case AT_EXECFD:
    531       1.15  christos 			pAUX_execfd = auxp;
    532       1.15  christos 			break;
    533       1.24    kleink 		case AT_PHDR:
    534       1.15  christos 			pAUX_phdr = auxp;
    535       1.15  christos 			break;
    536       1.24    kleink 		case AT_PHENT:
    537       1.15  christos 			pAUX_phent = auxp;
    538       1.15  christos 			break;
    539       1.24    kleink 		case AT_PHNUM:
    540       1.15  christos 			pAUX_phnum = auxp;
    541       1.15  christos 			break;
    542       1.54   mycroft #ifdef AT_EUID
    543       1.53  christos 		case AT_EUID:
    544       1.53  christos 			pAUX_euid = auxp;
    545       1.53  christos 			break;
    546       1.53  christos 		case AT_RUID:
    547       1.53  christos 			pAUX_ruid = auxp;
    548       1.53  christos 			break;
    549       1.53  christos 		case AT_EGID:
    550       1.53  christos 			pAUX_egid = auxp;
    551       1.53  christos 			break;
    552       1.53  christos 		case AT_RGID:
    553       1.53  christos 			pAUX_rgid = auxp;
    554       1.53  christos 			break;
    555       1.54   mycroft #endif
    556      1.114  christos #ifdef AT_SUN_EXECNAME
    557      1.114  christos 		case AT_SUN_EXECNAME:
    558      1.114  christos 			execname = (const char *)(const void *)auxp->a_v;
    559      1.114  christos 			break;
    560      1.114  christos #endif
    561       1.24    kleink 		case AT_PAGESZ:
    562       1.18        ws 			pAUX_pagesz = auxp;
    563       1.18        ws 			break;
    564       1.15  christos 		}
    565       1.15  christos 	}
    566       1.18        ws 
    567       1.69   mycroft 	/* Initialize and relocate ourselves. */
    568       1.90  junyoung 	if (pAUX_base == NULL) {
    569       1.90  junyoung 		_rtld_error("Bad pAUX_base");
    570       1.90  junyoung 		_rtld_die();
    571       1.90  junyoung 	}
    572       1.69   mycroft 	assert(pAUX_pagesz != NULL);
    573       1.24    kleink 	_rtld_pagesz = (int)pAUX_pagesz->a_v;
    574      1.114  christos 	_rtld_init((caddr_t)pAUX_base->a_v, (caddr_t)relocbase, execname);
    575        1.1       cgd 
    576       1.15  christos 	__progname = _rtld_objself.path;
    577       1.15  christos 	environ = env;
    578        1.1       cgd 
    579       1.53  christos 	_rtld_trust = ((pAUX_euid ? (uid_t)pAUX_euid->a_v : geteuid()) ==
    580       1.53  christos 	    (pAUX_ruid ? (uid_t)pAUX_ruid->a_v : getuid())) &&
    581       1.53  christos 	    ((pAUX_egid ? (gid_t)pAUX_egid->a_v : getegid()) ==
    582       1.53  christos 	    (pAUX_rgid ? (gid_t)pAUX_rgid->a_v : getgid()));
    583        1.1       cgd 
    584      1.134     joerg #ifdef DEBUG
    585      1.134     joerg 	ld_debug = NULL;
    586      1.134     joerg #endif
    587      1.134     joerg 	ld_bind_now = NULL;
    588      1.134     joerg 	ld_library_path = NULL;
    589      1.134     joerg 	ld_preload = NULL;
    590      1.134     joerg 	/*
    591      1.134     joerg 	 * Inline avoid using normal getenv/unsetenv here as the libc
    592      1.134     joerg 	 * code is quite a bit more complicated.
    593      1.134     joerg 	 */
    594      1.134     joerg 	for (oenvp = env; *env != NULL; ++env) {
    595      1.134     joerg 		static const char bind_var[] = "LD_BIND_NOW=";
    596      1.134     joerg 		static const char debug_var[] =  "LD_DEBUG=";
    597      1.134     joerg 		static const char path_var[] = "LD_LIBRARY_PATH=";
    598      1.134     joerg 		static const char preload_var[] = "LD_PRELOAD=";
    599      1.134     joerg #define LEN(x)	(sizeof(x) - 1)
    600      1.134     joerg 
    601      1.134     joerg 		if ((*env)[0] != 'L' || (*env)[1] != 'D') {
    602      1.134     joerg 			/*
    603      1.134     joerg 			 * Special case to skip most entries without
    604      1.134     joerg 			 * the more expensive calls to strncmp.
    605      1.134     joerg 			 */
    606      1.134     joerg 			*oenvp++ = *env;
    607      1.134     joerg 		} else if (strncmp(*env, debug_var, LEN(debug_var)) == 0) {
    608      1.134     joerg 			if (_rtld_trust) {
    609      1.134     joerg #ifdef DEBUG
    610      1.134     joerg 				ld_debug = *env + LEN(debug_var);
    611      1.134     joerg #endif
    612      1.134     joerg 				*oenvp++ = *env;
    613      1.134     joerg 			}
    614      1.134     joerg 		} else if (strncmp(*env, bind_var, LEN(bind_var)) == 0) {
    615      1.173     joerg 			if (_rtld_trust) {
    616      1.173     joerg 				ld_bind_now = *env + LEN(bind_var);
    617      1.173     joerg 				*oenvp++ = *env;
    618      1.173     joerg 			}
    619      1.134     joerg 		} else if (strncmp(*env, path_var, LEN(path_var)) == 0) {
    620      1.134     joerg 			if (_rtld_trust) {
    621      1.134     joerg 				ld_library_path = *env + LEN(path_var);
    622      1.134     joerg 				*oenvp++ = *env;
    623      1.134     joerg 			}
    624      1.134     joerg 		} else if (strncmp(*env, preload_var, LEN(preload_var)) == 0) {
    625      1.134     joerg 			if (_rtld_trust) {
    626      1.134     joerg 				ld_preload = *env + LEN(preload_var);
    627      1.134     joerg 				*oenvp++ = *env;
    628      1.134     joerg 			}
    629      1.134     joerg 		} else {
    630      1.134     joerg 			*oenvp++ = *env;
    631      1.134     joerg 		}
    632      1.134     joerg #undef LEN
    633      1.134     joerg 	}
    634      1.134     joerg 	*oenvp++ = NULL;
    635      1.134     joerg 
    636       1.15  christos 	if (ld_bind_now != NULL && *ld_bind_now != '\0')
    637       1.15  christos 		bind_now = true;
    638       1.15  christos 	if (_rtld_trust) {
    639        1.6    mhitch #ifdef DEBUG
    640       1.75   mycroft #ifdef RTLD_DEBUG
    641       1.75   mycroft 		debug = 0;
    642       1.75   mycroft #endif
    643       1.15  christos 		if (ld_debug != NULL && *ld_debug != '\0')
    644       1.15  christos 			debug = 1;
    645       1.15  christos #endif
    646      1.134     joerg 		_rtld_add_paths(execname, &_rtld_paths, ld_library_path);
    647      1.111  christos 	} else {
    648      1.115  christos 		execname = NULL;
    649       1.15  christos 	}
    650      1.114  christos 	_rtld_process_hints(execname, &_rtld_paths, &_rtld_xforms,
    651      1.113  christos 	    _PATH_LD_HINTS);
    652       1.66  junyoung 	dbg(("dynamic linker is initialized, mapbase=%p, relocbase=%p",
    653       1.58   mycroft 	     _rtld_objself.mapbase, _rtld_objself.relocbase));
    654       1.15  christos 
    655       1.15  christos 	/*
    656       1.15  christos          * Load the main program, or process its program header if it is
    657       1.15  christos          * already loaded.
    658       1.15  christos          */
    659       1.15  christos 	if (pAUX_execfd != NULL) {	/* Load the main program. */
    660       1.24    kleink 		int             fd = pAUX_execfd->a_v;
    661      1.110  christos 		const char *obj_name = argv[0] ? argv[0] : "main program";
    662       1.15  christos 		dbg(("loading main program"));
    663      1.110  christos 		_rtld_objmain = _rtld_map_object(obj_name, fd, NULL);
    664       1.15  christos 		close(fd);
    665       1.15  christos 		if (_rtld_objmain == NULL)
    666       1.15  christos 			_rtld_die();
    667       1.15  christos 	} else {		/* Main program already loaded. */
    668       1.15  christos 		const Elf_Phdr *phdr;
    669       1.15  christos 		int             phnum;
    670       1.15  christos 		caddr_t         entry;
    671       1.15  christos 
    672       1.15  christos 		dbg(("processing main program's program header"));
    673       1.15  christos 		assert(pAUX_phdr != NULL);
    674       1.24    kleink 		phdr = (const Elf_Phdr *) pAUX_phdr->a_v;
    675       1.15  christos 		assert(pAUX_phnum != NULL);
    676       1.24    kleink 		phnum = pAUX_phnum->a_v;
    677       1.15  christos 		assert(pAUX_phent != NULL);
    678       1.24    kleink 		assert(pAUX_phent->a_v == sizeof(Elf_Phdr));
    679       1.15  christos 		assert(pAUX_entry != NULL);
    680       1.24    kleink 		entry = (caddr_t) pAUX_entry->a_v;
    681       1.15  christos 		_rtld_objmain = _rtld_digest_phdr(phdr, phnum, entry);
    682       1.84   mycroft 		_rtld_objmain->path = xstrdup(argv[0] ? argv[0] :
    683       1.84   mycroft 		    "main program");
    684       1.89  junyoung 		_rtld_objmain->pathlen = strlen(_rtld_objmain->path);
    685       1.15  christos 	}
    686       1.15  christos 
    687       1.92   mycroft 	_rtld_objmain->mainprog = true;
    688      1.165     skrll 
    689       1.25   mycroft 	/*
    690       1.25   mycroft 	 * Get the actual dynamic linker pathname from the executable if
    691       1.25   mycroft 	 * possible.  (It should always be possible.)  That ensures that
    692      1.206     kamil 	 * the debugger will find the right dynamic linker even if a
    693      1.206     kamil 	 * non-standard one is being used.
    694       1.25   mycroft 	 */
    695       1.25   mycroft 	if (_rtld_objmain->interp != NULL &&
    696      1.171     skrll 	    strcmp(_rtld_objmain->interp, _rtld_objself.path) != 0) {
    697       1.25   mycroft 		_rtld_objself.path = xstrdup(_rtld_objmain->interp);
    698      1.171     skrll 		_rtld_objself.pathlen = strlen(_rtld_objself.path);
    699      1.171     skrll 	}
    700       1.66  junyoung 	dbg(("actual dynamic linker is %s", _rtld_objself.path));
    701      1.165     skrll 
    702      1.114  christos 	_rtld_digest_dynamic(execname, _rtld_objmain);
    703       1.15  christos 
    704       1.84   mycroft 	/* Link the main program into the list of objects. */
    705       1.84   mycroft 	*_rtld_objtail = _rtld_objmain;
    706       1.84   mycroft 	_rtld_objtail = &_rtld_objmain->next;
    707      1.131     skrll 	_rtld_objcount++;
    708      1.131     skrll 	_rtld_objloads++;
    709       1.84   mycroft 
    710       1.15  christos 	_rtld_linkmap_add(_rtld_objmain);
    711      1.178  christos 	_rtld_objself.path = xstrdup(_rtld_objself.path);
    712       1.15  christos 	_rtld_linkmap_add(&_rtld_objself);
    713       1.15  christos 
    714       1.15  christos 	++_rtld_objmain->refcount;
    715       1.84   mycroft 	_rtld_objmain->mainref = 1;
    716      1.117        ad 	_rtld_objlist_push_tail(&_rtld_list_main, _rtld_objmain);
    717       1.19    kleink 
    718      1.134     joerg 	if (ld_preload) {
    719      1.111  christos 		/*
    720      1.111  christos 		 * Pre-load user-specified objects after the main program
    721      1.111  christos 		 * but before any shared object dependencies.
    722      1.111  christos 		 */
    723      1.111  christos 		dbg(("preloading objects"));
    724      1.134     joerg 		if (_rtld_preload(ld_preload) == -1)
    725      1.127  christos 			_rtld_die();
    726      1.134     joerg 	}
    727       1.15  christos 
    728       1.15  christos 	dbg(("loading needed objects"));
    729      1.137     skrll 	if (_rtld_load_needed_objects(_rtld_objmain, _RTLD_MAIN) == -1)
    730       1.15  christos 		_rtld_die();
    731       1.15  christos 
    732      1.151    nonaka 	dbg(("checking for required versions"));
    733      1.151    nonaka 	for (obj = _rtld_objlist; obj != NULL; obj = obj->next) {
    734      1.151    nonaka 		if (_rtld_verify_object_versions(obj) == -1)
    735      1.151    nonaka 			_rtld_die();
    736      1.151    nonaka 	}
    737      1.151    nonaka 
    738      1.139     joerg #if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
    739      1.154     joerg 	dbg(("initializing initial Thread Local Storage offsets"));
    740      1.139     joerg 	/*
    741      1.139     joerg 	 * All initial objects get the TLS space from the static block.
    742      1.139     joerg 	 */
    743      1.139     joerg 	for (obj = _rtld_objlist; obj != NULL; obj = obj->next)
    744      1.139     joerg 		_rtld_tls_offset_allocate(obj);
    745      1.139     joerg #endif
    746      1.139     joerg 
    747       1.15  christos 	dbg(("relocating objects"));
    748       1.81   mycroft 	if (_rtld_relocate_objects(_rtld_objmain, bind_now) == -1)
    749       1.15  christos 		_rtld_die();
    750       1.15  christos 
    751       1.15  christos 	dbg(("doing copy relocations"));
    752       1.60   mycroft 	if (_rtld_do_copy_relocations(_rtld_objmain) == -1)
    753       1.15  christos 		_rtld_die();
    754       1.15  christos 
    755      1.154     joerg #if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
    756      1.154     joerg 	dbg(("initializing Thread Local Storage for main thread"));
    757      1.154     joerg 	/*
    758      1.154     joerg 	 * Set up TLS area for the main thread.
    759      1.154     joerg 	 * This has to be done after all relocations are processed,
    760      1.154     joerg 	 * since .tdata may contain relocations.
    761      1.154     joerg 	 */
    762      1.154     joerg 	_rtld_tls_initial_allocation();
    763      1.154     joerg #endif
    764      1.154     joerg 
    765       1.31       erh 	/*
    766       1.34  christos 	 * Set the __progname,  environ and, __mainprog_obj before
    767       1.34  christos 	 * calling anything that might use them.
    768       1.31       erh 	 */
    769       1.31       erh 	real___progname = _rtld_objmain_sym("__progname");
    770       1.31       erh 	if (real___progname) {
    771       1.64  christos 		if (argv[0] != NULL) {
    772       1.64  christos 			if ((*real___progname = strrchr(argv[0], '/')) == NULL)
    773       1.64  christos 				(*real___progname) = argv[0];
    774       1.64  christos 			else
    775       1.64  christos 				(*real___progname)++;
    776       1.64  christos 		} else {
    777       1.64  christos 			(*real___progname) = NULL;
    778       1.64  christos 		}
    779       1.31       erh 	}
    780       1.31       erh 	real_environ = _rtld_objmain_sym("environ");
    781       1.31       erh 	if (real_environ)
    782       1.31       erh 		*real_environ = environ;
    783       1.99     skrll 	/*
    784       1.99     skrll 	 * Set __mainprog_obj for old binaries.
    785       1.99     skrll 	 */
    786       1.34  christos 	real___mainprog_obj = _rtld_objmain_sym("__mainprog_obj");
    787       1.34  christos 	if (real___mainprog_obj)
    788       1.34  christos 		*real___mainprog_obj = _rtld_objmain;
    789       1.31       erh 
    790      1.206     kamil 	_rtld_debug_state();	/* say hello to the debugger! */
    791      1.184     joerg 
    792      1.148     joerg 	_rtld_exclusive_enter(&mask);
    793      1.141     joerg 
    794       1.15  christos 	dbg(("calling _init functions"));
    795      1.148     joerg 	_rtld_call_init_functions(&mask);
    796       1.15  christos 
    797       1.15  christos 	dbg(("control at program entry point = %p, obj = %p, exit = %p",
    798       1.15  christos 	     _rtld_objmain->entry, _rtld_objmain, _rtld_exit));
    799       1.15  christos 
    800      1.148     joerg 	_rtld_exclusive_exit(&mask);
    801      1.141     joerg 
    802       1.15  christos 	/*
    803       1.15  christos 	 * Return with the entry point and the exit procedure in at the top
    804       1.15  christos 	 * of stack.
    805       1.15  christos 	 */
    806       1.15  christos 
    807       1.15  christos 	((void **) osp)[0] = _rtld_exit;
    808      1.193     joerg 	((void **) osp)[1] = __UNCONST(_rtld_compat_obj);
    809       1.15  christos 	return (Elf_Addr) _rtld_objmain->entry;
    810        1.1       cgd }
    811        1.1       cgd 
    812        1.1       cgd void
    813       1.98     skrll _rtld_die(void)
    814        1.1       cgd {
    815       1.99     skrll 	const char *msg = dlerror();
    816        1.1       cgd 
    817       1.15  christos 	if (msg == NULL)
    818       1.15  christos 		msg = "Fatal error";
    819       1.52     soren 	xerrx(1, "%s", msg);
    820        1.1       cgd }
    821        1.1       cgd 
    822        1.1       cgd static Obj_Entry *
    823       1.98     skrll _rtld_dlcheck(void *handle)
    824        1.1       cgd {
    825       1.15  christos 	Obj_Entry *obj;
    826        1.1       cgd 
    827       1.15  christos 	for (obj = _rtld_objlist; obj != NULL; obj = obj->next)
    828       1.15  christos 		if (obj == (Obj_Entry *) handle)
    829       1.15  christos 			break;
    830       1.15  christos 
    831       1.15  christos 	if (obj == NULL || obj->dl_refcount == 0) {
    832      1.159  riastrad 		_rtld_error("Invalid shared object handle %p", handle);
    833       1.15  christos 		return NULL;
    834       1.15  christos 	}
    835       1.15  christos 	return obj;
    836        1.1       cgd }
    837        1.1       cgd 
    838        1.1       cgd static void
    839      1.117        ad _rtld_initlist_visit(Objlist* list, Obj_Entry *obj, int rev)
    840      1.117        ad {
    841      1.117        ad 	Needed_Entry* elm;
    842      1.117        ad 
    843      1.117        ad 	/* dbg(("_rtld_initlist_visit(%s)", obj->path)); */
    844      1.117        ad 
    845      1.117        ad 	if (obj->init_done)
    846      1.117        ad 		return;
    847      1.117        ad 	obj->init_done = 1;
    848      1.117        ad 
    849      1.117        ad 	for (elm = obj->needed; elm != NULL; elm = elm->next) {
    850      1.117        ad 		if (elm->obj != NULL) {
    851      1.117        ad 			_rtld_initlist_visit(list, elm->obj, rev);
    852      1.117        ad 		}
    853      1.117        ad 	}
    854      1.117        ad 
    855      1.117        ad 	if (rev) {
    856      1.117        ad 		_rtld_objlist_push_head(list, obj);
    857      1.117        ad 	} else {
    858      1.117        ad 		_rtld_objlist_push_tail(list, obj);
    859      1.117        ad 	}
    860      1.117        ad }
    861      1.117        ad 
    862      1.117        ad static void
    863      1.117        ad _rtld_initlist_tsort(Objlist* list, int rev)
    864      1.117        ad {
    865      1.117        ad 	dbg(("_rtld_initlist_tsort"));
    866      1.117        ad 
    867      1.117        ad 	Obj_Entry* obj;
    868      1.117        ad 
    869      1.194  christos 	/*
    870      1.194  christos 	 * We don't include objmain here (starting from next)
    871      1.194  christos 	 * because csu handles it
    872      1.194  christos 	 */
    873      1.117        ad 	for (obj = _rtld_objlist->next; obj; obj = obj->next) {
    874      1.117        ad 		obj->init_done = 0;
    875      1.117        ad 	}
    876      1.117        ad 
    877      1.117        ad 	for (obj = _rtld_objlist->next; obj; obj = obj->next) {
    878      1.117        ad 		_rtld_initlist_visit(list, obj, rev);
    879      1.117        ad 	}
    880      1.117        ad }
    881      1.117        ad 
    882      1.117        ad static void
    883       1.98     skrll _rtld_init_dag(Obj_Entry *root)
    884       1.25   mycroft {
    885       1.94    simonb 
    886       1.25   mycroft 	_rtld_init_dag1(root, root);
    887       1.25   mycroft }
    888       1.25   mycroft 
    889       1.25   mycroft static void
    890       1.98     skrll _rtld_init_dag1(Obj_Entry *root, Obj_Entry *obj)
    891       1.25   mycroft {
    892       1.25   mycroft 	const Needed_Entry *needed;
    893       1.25   mycroft 
    894       1.84   mycroft 	if (!obj->mainref) {
    895       1.84   mycroft 		if (_rtld_objlist_find(&obj->dldags, root))
    896       1.84   mycroft 			return;
    897      1.133     skrll 		dbg(("add %p (%s) to %p (%s) DAG", obj, obj->path, root,
    898       1.84   mycroft 		    root->path));
    899      1.117        ad 		_rtld_objlist_push_tail(&obj->dldags, root);
    900      1.117        ad 		_rtld_objlist_push_tail(&root->dagmembers, obj);
    901       1.84   mycroft 	}
    902       1.25   mycroft 	for (needed = obj->needed; needed != NULL; needed = needed->next)
    903       1.25   mycroft 		if (needed->obj != NULL)
    904       1.25   mycroft 			_rtld_init_dag1(root, needed->obj);
    905       1.25   mycroft }
    906       1.25   mycroft 
    907       1.25   mycroft /*
    908       1.25   mycroft  * Note, this is called only for objects loaded by dlopen().
    909       1.25   mycroft  */
    910       1.25   mycroft static void
    911      1.148     joerg _rtld_unload_object(sigset_t *mask, Obj_Entry *root, bool do_fini_funcs)
    912       1.25   mycroft {
    913       1.94    simonb 
    914       1.25   mycroft 	_rtld_unref_dag(root);
    915       1.25   mycroft 	if (root->refcount == 0) { /* We are finished with some objects. */
    916       1.25   mycroft 		Obj_Entry *obj;
    917       1.25   mycroft 		Obj_Entry **linkp;
    918       1.25   mycroft 		Objlist_Entry *elm;
    919       1.25   mycroft 
    920       1.25   mycroft 		/* Finalize objects that are about to be unmapped. */
    921       1.25   mycroft 		if (do_fini_funcs)
    922      1.148     joerg 			_rtld_call_fini_functions(mask, 0);
    923       1.25   mycroft 
    924       1.25   mycroft 		/* Remove the DAG from all objects' DAG lists. */
    925       1.50     lukem 		SIMPLEQ_FOREACH(elm, &root->dagmembers, link)
    926       1.25   mycroft 			_rtld_objlist_remove(&elm->obj->dldags, root);
    927       1.25   mycroft 
    928       1.25   mycroft 		/* Remove the DAG from the RTLD_GLOBAL list. */
    929       1.84   mycroft 		if (root->globalref) {
    930       1.84   mycroft 			root->globalref = 0;
    931       1.84   mycroft 			_rtld_objlist_remove(&_rtld_list_global, root);
    932       1.84   mycroft 		}
    933       1.25   mycroft 
    934       1.25   mycroft 		/* Unmap all objects that are no longer referenced. */
    935       1.25   mycroft 		linkp = &_rtld_objlist->next;
    936       1.25   mycroft 		while ((obj = *linkp) != NULL) {
    937       1.25   mycroft 			if (obj->refcount == 0) {
    938       1.25   mycroft 				dbg(("unloading \"%s\"", obj->path));
    939      1.118        ad 				if (obj->ehdr != MAP_FAILED)
    940      1.118        ad 					munmap(obj->ehdr, _rtld_pagesz);
    941       1.25   mycroft 				munmap(obj->mapbase, obj->mapsize);
    942       1.45  christos 				_rtld_objlist_remove(&_rtld_list_global, obj);
    943       1.25   mycroft 				_rtld_linkmap_delete(obj);
    944       1.25   mycroft 				*linkp = obj->next;
    945      1.129       roy 				_rtld_objcount--;
    946       1.25   mycroft 				_rtld_obj_free(obj);
    947       1.25   mycroft 			} else
    948       1.25   mycroft 				linkp = &obj->next;
    949       1.25   mycroft 		}
    950       1.25   mycroft 		_rtld_objtail = linkp;
    951       1.25   mycroft 	}
    952       1.25   mycroft }
    953       1.25   mycroft 
    954      1.137     skrll void
    955      1.137     skrll _rtld_ref_dag(Obj_Entry *root)
    956      1.137     skrll {
    957      1.137     skrll 	const Needed_Entry *needed;
    958      1.137     skrll 
    959      1.137     skrll 	assert(root);
    960      1.137     skrll 
    961      1.137     skrll 	++root->refcount;
    962      1.137     skrll 
    963      1.137     skrll 	dbg(("incremented reference on \"%s\" (%d)", root->path,
    964      1.137     skrll 	    root->refcount));
    965      1.137     skrll 	for (needed = root->needed; needed != NULL;
    966      1.137     skrll 	     needed = needed->next) {
    967      1.137     skrll 		if (needed->obj != NULL)
    968      1.137     skrll 			_rtld_ref_dag(needed->obj);
    969      1.137     skrll 	}
    970      1.137     skrll }
    971      1.137     skrll 
    972       1.25   mycroft static void
    973       1.98     skrll _rtld_unref_dag(Obj_Entry *root)
    974        1.1       cgd {
    975       1.94    simonb 
    976       1.33  jdolecek 	assert(root);
    977       1.15  christos 	assert(root->refcount != 0);
    978      1.137     skrll 
    979       1.15  christos 	--root->refcount;
    980      1.137     skrll 	dbg(("decremented reference on \"%s\" (%d)", root->path,
    981      1.137     skrll 	    root->refcount));
    982      1.137     skrll 
    983       1.15  christos 	if (root->refcount == 0) {
    984       1.15  christos 		const Needed_Entry *needed;
    985       1.15  christos 
    986       1.15  christos 		for (needed = root->needed; needed != NULL;
    987       1.32  jdolecek 		     needed = needed->next) {
    988       1.32  jdolecek 			if (needed->obj != NULL)
    989       1.32  jdolecek 				_rtld_unref_dag(needed->obj);
    990       1.32  jdolecek 		}
    991       1.15  christos 	}
    992        1.1       cgd }
    993        1.1       cgd 
    994      1.106   thorpej __strong_alias(__dlclose,dlclose)
    995        1.1       cgd int
    996       1.99     skrll dlclose(void *handle)
    997        1.1       cgd {
    998      1.143     joerg 	Obj_Entry *root;
    999      1.148     joerg 	sigset_t mask;
   1000        1.1       cgd 
   1001      1.144     joerg 	dbg(("dlclose of %p", handle));
   1002      1.143     joerg 
   1003      1.148     joerg 	_rtld_exclusive_enter(&mask);
   1004      1.143     joerg 
   1005      1.143     joerg 	root = _rtld_dlcheck(handle);
   1006      1.143     joerg 
   1007      1.143     joerg 	if (root == NULL) {
   1008      1.148     joerg 		_rtld_exclusive_exit(&mask);
   1009       1.15  christos 		return -1;
   1010      1.143     joerg 	}
   1011        1.1       cgd 
   1012       1.15  christos 	_rtld_debug.r_state = RT_DELETE;
   1013       1.15  christos 	_rtld_debug_state();
   1014       1.15  christos 
   1015       1.15  christos 	--root->dl_refcount;
   1016      1.148     joerg 	_rtld_unload_object(&mask, root, true);
   1017       1.15  christos 
   1018       1.15  christos 	_rtld_debug.r_state = RT_CONSISTENT;
   1019       1.15  christos 	_rtld_debug_state();
   1020        1.1       cgd 
   1021      1.148     joerg 	_rtld_exclusive_exit(&mask);
   1022      1.143     joerg 
   1023       1.15  christos 	return 0;
   1024        1.1       cgd }
   1025        1.1       cgd 
   1026      1.106   thorpej __strong_alias(__dlerror,dlerror)
   1027        1.1       cgd char *
   1028       1.99     skrll dlerror(void)
   1029        1.1       cgd {
   1030       1.15  christos 	char *msg = error_message;
   1031       1.94    simonb 
   1032       1.15  christos 	error_message = NULL;
   1033       1.15  christos 	return msg;
   1034        1.1       cgd }
   1035        1.1       cgd 
   1036      1.106   thorpej __strong_alias(__dlopen,dlopen)
   1037        1.1       cgd void *
   1038       1.99     skrll dlopen(const char *name, int mode)
   1039       1.15  christos {
   1040  1.212.2.1    martin 	Obj_Entry **old_obj_tail;
   1041       1.15  christos 	Obj_Entry *obj = NULL;
   1042      1.137     skrll 	int flags = _RTLD_DLOPEN;
   1043      1.137     skrll 	bool nodelete;
   1044      1.137     skrll 	bool now;
   1045      1.148     joerg 	sigset_t mask;
   1046      1.151    nonaka 	int result;
   1047      1.137     skrll 
   1048  1.212.2.2    martin 	dbg(("dlopen of %s 0x%x", name, mode));
   1049      1.144     joerg 
   1050      1.148     joerg 	_rtld_exclusive_enter(&mask);
   1051      1.141     joerg 
   1052  1.212.2.1    martin 	old_obj_tail = _rtld_objtail;
   1053  1.212.2.1    martin 
   1054      1.137     skrll 	flags |= (mode & RTLD_GLOBAL) ? _RTLD_GLOBAL : 0;
   1055      1.137     skrll 	flags |= (mode & RTLD_NOLOAD) ? _RTLD_NOLOAD : 0;
   1056      1.165     skrll 
   1057      1.137     skrll 	nodelete = (mode & RTLD_NODELETE) ? true : false;
   1058      1.137     skrll 	now = ((mode & RTLD_MODEMASK) == RTLD_NOW) ? true : false;
   1059       1.15  christos 
   1060       1.15  christos 	_rtld_debug.r_state = RT_ADD;
   1061       1.15  christos 	_rtld_debug_state();
   1062       1.15  christos 
   1063       1.15  christos 	if (name == NULL) {
   1064       1.15  christos 		obj = _rtld_objmain;
   1065       1.25   mycroft 		obj->refcount++;
   1066       1.67   mycroft 	} else
   1067      1.137     skrll 		obj = _rtld_load_library(name, _rtld_objmain, flags);
   1068      1.137     skrll 
   1069        1.1       cgd 
   1070       1.15  christos 	if (obj != NULL) {
   1071       1.15  christos 		++obj->dl_refcount;
   1072       1.15  christos 		if (*old_obj_tail != NULL) {	/* We loaded something new. */
   1073       1.15  christos 			assert(*old_obj_tail == obj);
   1074       1.15  christos 
   1075      1.151    nonaka 			result = _rtld_load_needed_objects(obj, flags);
   1076      1.151    nonaka 			if (result != -1) {
   1077      1.151    nonaka 				Objlist_Entry *entry;
   1078      1.151    nonaka 				_rtld_init_dag(obj);
   1079      1.151    nonaka 				SIMPLEQ_FOREACH(entry, &obj->dagmembers, link) {
   1080      1.151    nonaka 					result = _rtld_verify_object_versions(entry->obj);
   1081      1.151    nonaka 					if (result == -1)
   1082      1.151    nonaka 						break;
   1083      1.151    nonaka 				}
   1084      1.151    nonaka 			}
   1085      1.151    nonaka 			if (result == -1 || _rtld_relocate_objects(obj,
   1086      1.151    nonaka 			    (now || obj->z_now)) == -1) {
   1087      1.148     joerg 				_rtld_unload_object(&mask, obj, false);
   1088       1.25   mycroft 				obj->dl_refcount--;
   1089       1.15  christos 				obj = NULL;
   1090      1.117        ad 			} else {
   1091      1.148     joerg 				_rtld_call_init_functions(&mask);
   1092      1.117        ad 			}
   1093       1.15  christos 		}
   1094      1.137     skrll 		if (obj != NULL) {
   1095      1.137     skrll 			if ((nodelete || obj->z_nodelete) && !obj->ref_nodel) {
   1096      1.137     skrll 				dbg(("dlopen obj %s nodelete", obj->path));
   1097      1.137     skrll 				_rtld_ref_dag(obj);
   1098      1.137     skrll 				obj->z_nodelete = obj->ref_nodel = true;
   1099      1.137     skrll 			}
   1100      1.137     skrll 		}
   1101       1.15  christos 	}
   1102       1.15  christos 	_rtld_debug.r_state = RT_CONSISTENT;
   1103       1.15  christos 	_rtld_debug_state();
   1104        1.1       cgd 
   1105  1.212.2.2    martin 	dbg(("dlopen of %s 0x%x returned %p%s%s%s", name, mode, obj,
   1106  1.212.2.2    martin 	    obj ? "" : " (", obj ? "" : error_message, obj ? "" : ")"));
   1107  1.212.2.2    martin 
   1108      1.148     joerg 	_rtld_exclusive_exit(&mask);
   1109      1.141     joerg 
   1110       1.15  christos 	return obj;
   1111       1.31       erh }
   1112       1.31       erh 
   1113       1.31       erh /*
   1114       1.31       erh  * Find a symbol in the main program.
   1115       1.31       erh  */
   1116       1.31       erh void *
   1117       1.98     skrll _rtld_objmain_sym(const char *name)
   1118       1.31       erh {
   1119      1.202     kamil 	Elf_Hash hash;
   1120       1.31       erh 	const Elf_Sym *def;
   1121       1.31       erh 	const Obj_Entry *obj;
   1122      1.129       roy 	DoneList donelist;
   1123       1.31       erh 
   1124      1.202     kamil 	hash.sysv = _rtld_sysv_hash(name);
   1125      1.202     kamil 	hash.gnu = _rtld_gnu_hash(name);
   1126       1.31       erh 	obj = _rtld_objmain;
   1127      1.129       roy 	_rtld_donelist_init(&donelist);
   1128       1.31       erh 
   1129      1.202     kamil 	def = _rtld_symlook_list(name, &hash, &_rtld_list_main, &obj, 0,
   1130      1.151    nonaka 	    NULL, &donelist);
   1131      1.129       roy 
   1132       1.31       erh 	if (def != NULL)
   1133       1.31       erh 		return obj->relocbase + def->st_value;
   1134      1.136     skrll 	return NULL;
   1135        1.1       cgd }
   1136        1.1       cgd 
   1137      1.208     joerg #if defined(__powerpc__) && !defined(__clang__)
   1138      1.183       chs static __noinline void *
   1139      1.121  macallan hackish_return_address(void)
   1140      1.121  macallan {
   1141      1.190  jakllsch #if __GNUC_PREREQ__(6,0)
   1142      1.189       mrg #pragma GCC diagnostic push
   1143      1.189       mrg #pragma GCC diagnostic ignored "-Wframe-address"
   1144      1.190  jakllsch #endif
   1145      1.121  macallan 	return __builtin_return_address(1);
   1146      1.190  jakllsch #if __GNUC_PREREQ__(6,0)
   1147      1.189       mrg #pragma GCC diagnostic pop
   1148      1.190  jakllsch #endif
   1149      1.121  macallan }
   1150      1.121  macallan #endif
   1151      1.121  macallan 
   1152      1.141     joerg #ifdef __HAVE_FUNCTION_DESCRIPTORS
   1153      1.148     joerg #define	lookup_mutex_enter()	_rtld_exclusive_enter(&mask)
   1154      1.148     joerg #define	lookup_mutex_exit()	_rtld_exclusive_exit(&mask)
   1155      1.141     joerg #else
   1156      1.141     joerg #define	lookup_mutex_enter()	_rtld_shared_enter()
   1157      1.141     joerg #define	lookup_mutex_exit()	_rtld_shared_exit()
   1158      1.141     joerg #endif
   1159      1.141     joerg 
   1160      1.151    nonaka static void *
   1161      1.155     joerg do_dlsym(void *handle, const char *name, const Ver_Entry *ventry, void *retaddr)
   1162       1.15  christos {
   1163       1.25   mycroft 	const Obj_Entry *obj;
   1164      1.202     kamil 	Elf_Hash hash;
   1165       1.25   mycroft 	const Elf_Sym *def;
   1166       1.15  christos 	const Obj_Entry *defobj;
   1167      1.148     joerg 	DoneList donelist;
   1168      1.151    nonaka 	const u_int flags = SYMLOOK_DLSYM | SYMLOOK_IN_PLT;
   1169      1.148     joerg #ifdef __HAVE_FUNCTION_DESCRIPTORS
   1170      1.148     joerg 	sigset_t mask;
   1171      1.148     joerg #endif
   1172      1.141     joerg 
   1173      1.141     joerg 	lookup_mutex_enter();
   1174      1.141     joerg 
   1175      1.202     kamil 	hash.sysv = _rtld_sysv_hash(name);
   1176      1.202     kamil 	hash.gnu = _rtld_gnu_hash(name);
   1177       1.92   mycroft 	def = NULL;
   1178       1.92   mycroft 	defobj = NULL;
   1179      1.165     skrll 
   1180       1.93  christos 	switch ((intptr_t)handle) {
   1181       1.93  christos 	case (intptr_t)NULL:
   1182       1.93  christos 	case (intptr_t)RTLD_NEXT:
   1183       1.93  christos 	case (intptr_t)RTLD_DEFAULT:
   1184       1.93  christos 	case (intptr_t)RTLD_SELF:
   1185       1.30  christos 		if ((obj = _rtld_obj_from_addr(retaddr)) == NULL) {
   1186       1.30  christos 			_rtld_error("Cannot determine caller's shared object");
   1187      1.141     joerg 			lookup_mutex_exit();
   1188       1.30  christos 			return NULL;
   1189       1.30  christos 		}
   1190       1.93  christos 
   1191       1.93  christos 		switch ((intptr_t)handle) {
   1192       1.93  christos 		case (intptr_t)NULL:	 /* Just the caller's shared object. */
   1193      1.202     kamil 			def = _rtld_symlook_obj(name, &hash, obj, flags, ventry);
   1194       1.92   mycroft 			defobj = obj;
   1195       1.93  christos 			break;
   1196       1.93  christos 
   1197       1.93  christos 		case (intptr_t)RTLD_NEXT:	/* Objects after callers */
   1198       1.93  christos 			obj = obj->next;
   1199       1.93  christos 			/*FALLTHROUGH*/
   1200       1.93  christos 
   1201       1.93  christos 		case (intptr_t)RTLD_SELF:	/* Caller included */
   1202       1.93  christos 			for (; obj; obj = obj->next) {
   1203      1.202     kamil 				if ((def = _rtld_symlook_obj(name, &hash, obj,
   1204      1.151    nonaka 				    flags, ventry)) != NULL) {
   1205       1.92   mycroft 					defobj = obj;
   1206       1.92   mycroft 					break;
   1207       1.92   mycroft 				}
   1208       1.92   mycroft 			}
   1209      1.179  christos 			/*
   1210      1.180  christos 			 * Search the dynamic linker itself, and possibly
   1211      1.180  christos 			 * resolve the symbol from there if it is not defined
   1212      1.179  christos 			 * already or weak. This is how the application links
   1213      1.181  christos 			 * to dynamic linker services such as dlopen.
   1214      1.179  christos 			 */
   1215      1.179  christos 			if (!def || ELF_ST_BIND(def->st_info) == STB_WEAK) {
   1216      1.179  christos 				const Elf_Sym *symp = _rtld_symlook_obj(name,
   1217      1.202     kamil 				    &hash, &_rtld_objself, flags, ventry);
   1218      1.181  christos 				if (symp != NULL) {
   1219      1.179  christos 					def = symp;
   1220      1.179  christos 					defobj = &_rtld_objself;
   1221      1.179  christos 				}
   1222      1.179  christos 			}
   1223       1.93  christos 			break;
   1224       1.93  christos 
   1225       1.93  christos 		case (intptr_t)RTLD_DEFAULT:
   1226      1.202     kamil 			def = _rtld_symlook_default(name, &hash, obj, &defobj,
   1227      1.151    nonaka 			    flags, ventry);
   1228       1.93  christos 			break;
   1229       1.93  christos 
   1230       1.93  christos 		default:
   1231       1.93  christos 			abort();
   1232       1.92   mycroft 		}
   1233       1.93  christos 		break;
   1234       1.93  christos 
   1235       1.93  christos 	default:
   1236      1.141     joerg 		if ((obj = _rtld_dlcheck(handle)) == NULL) {
   1237      1.141     joerg 			lookup_mutex_exit();
   1238       1.30  christos 			return NULL;
   1239      1.141     joerg 		}
   1240      1.141     joerg 
   1241      1.129       roy 		_rtld_donelist_init(&donelist);
   1242      1.129       roy 
   1243       1.92   mycroft 		if (obj->mainprog) {
   1244       1.93  christos 			/* Search main program and all libraries loaded by it */
   1245      1.202     kamil 			def = _rtld_symlook_list(name, &hash, &_rtld_list_main,
   1246      1.151    nonaka 			    &defobj, flags, ventry, &donelist);
   1247       1.92   mycroft 		} else {
   1248      1.122     skrll 			Needed_Entry fake;
   1249      1.129       roy 			DoneList depth;
   1250      1.122     skrll 
   1251      1.122     skrll 			/* Search the object and all the libraries loaded by it. */
   1252      1.122     skrll 			fake.next = NULL;
   1253      1.124  christos 			fake.obj = __UNCONST(obj);
   1254      1.122     skrll 			fake.name = 0;
   1255      1.129       roy 
   1256      1.129       roy 			_rtld_donelist_init(&depth);
   1257      1.202     kamil 			def = _rtld_symlook_needed(name, &hash, &fake, &defobj,
   1258      1.151    nonaka 			    flags, ventry, &donelist, &depth);
   1259       1.25   mycroft 		}
   1260      1.129       roy 
   1261       1.93  christos 		break;
   1262       1.30  christos 	}
   1263      1.165     skrll 
   1264       1.51  fredette 	if (def != NULL) {
   1265      1.141     joerg 		void *p;
   1266      1.174     joerg 
   1267      1.174     joerg 		if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC) {
   1268      1.174     joerg #ifdef __HAVE_FUNCTION_DESCRIPTORS
   1269      1.174     joerg 			lookup_mutex_exit();
   1270      1.174     joerg 			_rtld_shared_enter();
   1271      1.174     joerg #endif
   1272      1.174     joerg 			p = (void *)_rtld_resolve_ifunc(defobj, def);
   1273      1.174     joerg 			_rtld_shared_exit();
   1274      1.174     joerg 			return p;
   1275      1.174     joerg 		}
   1276      1.174     joerg 
   1277       1.51  fredette #ifdef __HAVE_FUNCTION_DESCRIPTORS
   1278      1.141     joerg 		if (ELF_ST_TYPE(def->st_info) == STT_FUNC) {
   1279      1.142     joerg 			p = (void *)_rtld_function_descriptor_alloc(defobj,
   1280      1.142     joerg 			    def, 0);
   1281      1.141     joerg 			lookup_mutex_exit();
   1282      1.141     joerg 			return p;
   1283      1.141     joerg 		}
   1284       1.51  fredette #endif /* __HAVE_FUNCTION_DESCRIPTORS */
   1285      1.141     joerg 		p = defobj->relocbase + def->st_value;
   1286      1.141     joerg 		lookup_mutex_exit();
   1287      1.141     joerg 		return p;
   1288       1.51  fredette 	}
   1289      1.165     skrll 
   1290      1.101   mycroft 	_rtld_error("Undefined symbol \"%s\"", name);
   1291      1.141     joerg 	lookup_mutex_exit();
   1292       1.92   mycroft 	return NULL;
   1293       1.25   mycroft }
   1294        1.1       cgd 
   1295      1.151    nonaka __strong_alias(__dlsym,dlsym)
   1296      1.151    nonaka void *
   1297      1.151    nonaka dlsym(void *handle, const char *name)
   1298      1.151    nonaka {
   1299      1.155     joerg 	void *retaddr;
   1300      1.151    nonaka 
   1301      1.151    nonaka 	dbg(("dlsym of %s in %p", name, handle));
   1302      1.151    nonaka 
   1303      1.208     joerg #if defined(__powerpc__) && !defined(__clang__)
   1304      1.155     joerg 	retaddr = hackish_return_address();
   1305      1.155     joerg #else
   1306      1.155     joerg 	retaddr = __builtin_return_address(0);
   1307      1.155     joerg #endif
   1308      1.155     joerg 	return do_dlsym(handle, name, NULL, retaddr);
   1309      1.151    nonaka }
   1310      1.151    nonaka 
   1311      1.151    nonaka __strong_alias(__dlvsym,dlvsym)
   1312      1.151    nonaka void *
   1313      1.151    nonaka dlvsym(void *handle, const char *name, const char *version)
   1314      1.151    nonaka {
   1315      1.151    nonaka 	Ver_Entry *ventry = NULL;
   1316      1.151    nonaka 	Ver_Entry ver_entry;
   1317      1.155     joerg 	void *retaddr;
   1318      1.151    nonaka 
   1319      1.151    nonaka 	dbg(("dlvsym of %s@%s in %p", name, version ? version : NULL, handle));
   1320      1.151    nonaka 
   1321      1.151    nonaka 	if (version != NULL) {
   1322      1.151    nonaka 		ver_entry.name = version;
   1323      1.151    nonaka 		ver_entry.file = NULL;
   1324      1.202     kamil 		ver_entry.hash = _rtld_sysv_hash(version);
   1325      1.151    nonaka 		ver_entry.flags = 0;
   1326      1.151    nonaka 		ventry = &ver_entry;
   1327      1.151    nonaka 	}
   1328      1.208     joerg #if defined(__powerpc__) && !defined(__clang__)
   1329      1.155     joerg 	retaddr = hackish_return_address();
   1330      1.155     joerg #else
   1331      1.155     joerg 	retaddr = __builtin_return_address(0);
   1332      1.155     joerg #endif
   1333      1.155     joerg 	return do_dlsym(handle, name, ventry, retaddr);
   1334      1.151    nonaka }
   1335      1.151    nonaka 
   1336      1.106   thorpej __strong_alias(__dladdr,dladdr)
   1337       1.25   mycroft int
   1338       1.99     skrll dladdr(const void *addr, Dl_info *info)
   1339       1.25   mycroft {
   1340       1.25   mycroft 	const Obj_Entry *obj;
   1341       1.51  fredette 	const Elf_Sym *def, *best_def;
   1342       1.25   mycroft 	void *symbol_addr;
   1343       1.25   mycroft 	unsigned long symoffset;
   1344      1.149     joerg #ifdef __HAVE_FUNCTION_DESCRIPTORS
   1345      1.149     joerg 	sigset_t mask;
   1346      1.149     joerg #endif
   1347      1.141     joerg 
   1348      1.144     joerg 	dbg(("dladdr of %p", addr));
   1349      1.144     joerg 
   1350      1.141     joerg 	lookup_mutex_enter();
   1351      1.141     joerg 
   1352       1.51  fredette #ifdef __HAVE_FUNCTION_DESCRIPTORS
   1353       1.51  fredette 	addr = _rtld_function_descriptor_function(addr);
   1354       1.51  fredette #endif /* __HAVE_FUNCTION_DESCRIPTORS */
   1355       1.51  fredette 
   1356       1.25   mycroft 	obj = _rtld_obj_from_addr(addr);
   1357       1.25   mycroft 	if (obj == NULL) {
   1358       1.25   mycroft 		_rtld_error("No shared object contains address");
   1359      1.176     joerg 		lookup_mutex_exit();
   1360       1.25   mycroft 		return 0;
   1361       1.25   mycroft 	}
   1362       1.25   mycroft 	info->dli_fname = obj->path;
   1363       1.25   mycroft 	info->dli_fbase = obj->mapbase;
   1364       1.25   mycroft 	info->dli_saddr = (void *)0;
   1365       1.25   mycroft 	info->dli_sname = NULL;
   1366      1.165     skrll 
   1367       1.15  christos 	/*
   1368       1.25   mycroft 	 * Walk the symbol list looking for the symbol whose address is
   1369       1.25   mycroft 	 * closest to the address sent in.
   1370       1.25   mycroft 	 */
   1371       1.51  fredette 	best_def = NULL;
   1372       1.25   mycroft 	for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
   1373       1.25   mycroft 		def = obj->symtab + symoffset;
   1374       1.25   mycroft 
   1375       1.25   mycroft 		/*
   1376       1.25   mycroft 		 * For skip the symbol if st_shndx is either SHN_UNDEF or
   1377       1.25   mycroft 		 * SHN_COMMON.
   1378       1.25   mycroft 		 */
   1379       1.25   mycroft 		if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
   1380       1.25   mycroft 			continue;
   1381       1.25   mycroft 
   1382       1.25   mycroft 		/*
   1383       1.25   mycroft 		 * If the symbol is greater than the specified address, or if it
   1384       1.25   mycroft 		 * is further away from addr than the current nearest symbol,
   1385       1.25   mycroft 		 * then reject it.
   1386       1.25   mycroft 		 */
   1387       1.25   mycroft 		symbol_addr = obj->relocbase + def->st_value;
   1388       1.25   mycroft 		if (symbol_addr > addr || symbol_addr < info->dli_saddr)
   1389       1.25   mycroft 			continue;
   1390       1.25   mycroft 
   1391       1.25   mycroft 		/* Update our idea of the nearest symbol. */
   1392       1.25   mycroft 		info->dli_sname = obj->strtab + def->st_name;
   1393       1.25   mycroft 		info->dli_saddr = symbol_addr;
   1394       1.51  fredette 		best_def = def;
   1395        1.1       cgd 
   1396      1.170  christos 
   1397       1.25   mycroft 		/* Exact match? */
   1398       1.25   mycroft 		if (info->dli_saddr == addr)
   1399       1.25   mycroft 			break;
   1400       1.25   mycroft 	}
   1401       1.51  fredette 
   1402       1.51  fredette #ifdef __HAVE_FUNCTION_DESCRIPTORS
   1403       1.51  fredette 	if (best_def != NULL && ELF_ST_TYPE(best_def->st_info) == STT_FUNC)
   1404      1.165     skrll 		info->dli_saddr = (void *)_rtld_function_descriptor_alloc(obj,
   1405       1.51  fredette 		    best_def, 0);
   1406      1.170  christos #else
   1407      1.170  christos 	__USE(best_def);
   1408       1.51  fredette #endif /* __HAVE_FUNCTION_DESCRIPTORS */
   1409       1.51  fredette 
   1410      1.141     joerg 	lookup_mutex_exit();
   1411       1.25   mycroft 	return 1;
   1412        1.1       cgd }
   1413        1.1       cgd 
   1414      1.125     pooka __strong_alias(__dlinfo,dlinfo)
   1415      1.125     pooka int
   1416      1.125     pooka dlinfo(void *handle, int req, void *v)
   1417      1.125     pooka {
   1418      1.125     pooka 	const Obj_Entry *obj;
   1419      1.125     pooka 	void *retaddr;
   1420      1.125     pooka 
   1421      1.144     joerg 	dbg(("dlinfo for %p %d", handle, req));
   1422      1.144     joerg 
   1423      1.141     joerg 	_rtld_shared_enter();
   1424      1.141     joerg 
   1425      1.125     pooka 	if (handle == RTLD_SELF) {
   1426      1.208     joerg #if defined(__powerpc__) && !defined(__clang__)
   1427      1.125     pooka 		retaddr = hackish_return_address();
   1428      1.125     pooka #else
   1429      1.125     pooka 		retaddr = __builtin_return_address(0);
   1430      1.125     pooka #endif
   1431      1.125     pooka 		if ((obj = _rtld_obj_from_addr(retaddr)) == NULL) {
   1432      1.125     pooka 			_rtld_error("Cannot determine caller's shared object");
   1433      1.141     joerg 			_rtld_shared_exit();
   1434      1.125     pooka 			return -1;
   1435      1.125     pooka 		}
   1436      1.125     pooka 	} else {
   1437      1.125     pooka 		if ((obj = _rtld_dlcheck(handle)) == NULL) {
   1438      1.141     joerg 			_rtld_shared_exit();
   1439      1.125     pooka 			return -1;
   1440      1.125     pooka 		}
   1441      1.125     pooka 	}
   1442      1.125     pooka 
   1443      1.125     pooka 	switch (req) {
   1444      1.125     pooka 	case RTLD_DI_LINKMAP:
   1445      1.125     pooka 		{
   1446      1.125     pooka 		const struct link_map **map = v;
   1447      1.125     pooka 
   1448      1.125     pooka 		*map = &obj->linkmap;
   1449      1.125     pooka 		break;
   1450      1.125     pooka 		}
   1451      1.125     pooka 
   1452      1.125     pooka 	default:
   1453      1.125     pooka 		_rtld_error("Invalid request");
   1454      1.141     joerg 		_rtld_shared_exit();
   1455      1.125     pooka 		return -1;
   1456      1.125     pooka 	}
   1457      1.125     pooka 
   1458      1.141     joerg 	_rtld_shared_exit();
   1459      1.125     pooka 	return 0;
   1460      1.125     pooka }
   1461      1.125     pooka 
   1462      1.198     kamil static void
   1463      1.198     kamil _rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
   1464      1.198     kamil {
   1465      1.198     kamil 
   1466      1.198     kamil 	phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
   1467      1.198     kamil 	/* XXX: wrong but not fixing it yet */
   1468      1.198     kamil 	phdr_info->dlpi_name = obj->path;
   1469      1.198     kamil 	phdr_info->dlpi_phdr = obj->phdr;
   1470      1.198     kamil 	phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
   1471      1.198     kamil #if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
   1472      1.198     kamil 	phdr_info->dlpi_tls_modid = obj->tlsindex;
   1473      1.198     kamil 	phdr_info->dlpi_tls_data = obj->tlsinit;
   1474      1.198     kamil #else
   1475      1.198     kamil 	phdr_info->dlpi_tls_modid = 0;
   1476      1.198     kamil 	phdr_info->dlpi_tls_data = 0;
   1477      1.198     kamil #endif
   1478      1.198     kamil 	phdr_info->dlpi_adds = _rtld_objloads;
   1479      1.198     kamil 	phdr_info->dlpi_subs = _rtld_objloads - _rtld_objcount;
   1480      1.198     kamil }
   1481      1.198     kamil 
   1482      1.131     skrll __strong_alias(__dl_iterate_phdr,dl_iterate_phdr);
   1483      1.131     skrll int
   1484      1.131     skrll dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *), void *param)
   1485      1.131     skrll {
   1486      1.131     skrll 	struct dl_phdr_info phdr_info;
   1487      1.131     skrll 	const Obj_Entry *obj;
   1488      1.131     skrll 	int error = 0;
   1489      1.131     skrll 
   1490      1.144     joerg 	dbg(("dl_iterate_phdr"));
   1491      1.144     joerg 
   1492      1.141     joerg 	_rtld_shared_enter();
   1493      1.141     joerg 
   1494      1.131     skrll 	for (obj = _rtld_objlist;  obj != NULL;  obj = obj->next) {
   1495      1.198     kamil 		_rtld_fill_dl_phdr_info(obj, &phdr_info);
   1496      1.131     skrll 
   1497      1.141     joerg 		/* XXXlocking: exit point */
   1498      1.131     skrll 		error = callback(&phdr_info, sizeof(phdr_info), param);
   1499      1.131     skrll 		if (error)
   1500      1.131     skrll 			break;
   1501      1.131     skrll 	}
   1502      1.131     skrll 
   1503      1.198     kamil 	if (error == 0) {
   1504      1.198     kamil 		_rtld_fill_dl_phdr_info(&_rtld_objself, &phdr_info);
   1505      1.198     kamil 
   1506      1.198     kamil 		/* XXXlocking: exit point */
   1507      1.198     kamil 		error = callback(&phdr_info, sizeof(phdr_info), param);
   1508      1.198     kamil 	}
   1509      1.198     kamil 
   1510      1.141     joerg 	_rtld_shared_exit();
   1511      1.131     skrll 	return error;
   1512      1.131     skrll }
   1513      1.131     skrll 
   1514      1.185     joerg void
   1515      1.185     joerg __dl_cxa_refcount(void *addr, ssize_t delta)
   1516      1.185     joerg {
   1517      1.185     joerg 	sigset_t mask;
   1518      1.185     joerg 	Obj_Entry *obj;
   1519      1.185     joerg 
   1520      1.185     joerg 	if (delta == 0)
   1521      1.185     joerg 		return;
   1522      1.185     joerg 
   1523      1.185     joerg 	dbg(("__dl_cxa_refcount of %p with %zd", addr, delta));
   1524      1.185     joerg 
   1525      1.185     joerg 	_rtld_exclusive_enter(&mask);
   1526      1.185     joerg 	obj = _rtld_obj_from_addr(addr);
   1527      1.185     joerg 
   1528      1.185     joerg 	if (obj == NULL) {
   1529      1.185     joerg 		dbg(("__dl_cxa_refcont: address not found"));
   1530      1.185     joerg 		_rtld_error("No shared object contains address");
   1531      1.185     joerg 		_rtld_exclusive_exit(&mask);
   1532      1.185     joerg 		return;
   1533      1.185     joerg 	}
   1534      1.185     joerg 	if (delta > 0 && obj->cxa_refcount > SIZE_MAX - delta)
   1535      1.185     joerg 		_rtld_error("Reference count overflow");
   1536      1.185     joerg 	else if (delta < 0 && obj->cxa_refcount < -1 + (size_t)-(delta + 1))
   1537      1.185     joerg 		_rtld_error("Reference count underflow");
   1538      1.185     joerg 	else {
   1539      1.185     joerg 		if (obj->cxa_refcount == 0)
   1540      1.185     joerg 			++obj->refcount;
   1541      1.185     joerg 		obj->cxa_refcount += delta;
   1542      1.185     joerg 		dbg(("new reference count: %zu", obj->cxa_refcount));
   1543      1.185     joerg 		if (obj->cxa_refcount == 0) {
   1544      1.185     joerg 			--obj->refcount;
   1545      1.185     joerg 			if (obj->refcount == 0)
   1546      1.185     joerg 				_rtld_unload_object(&mask, obj, true);
   1547      1.185     joerg 		}
   1548      1.185     joerg 	}
   1549      1.185     joerg 
   1550      1.185     joerg 	_rtld_exclusive_exit(&mask);
   1551      1.185     joerg }
   1552      1.185     joerg 
   1553      1.204     joerg pid_t __fork(void);
   1554      1.204     joerg 
   1555      1.204     joerg __dso_public pid_t
   1556      1.205     joerg __locked_fork(int *my_errno)
   1557      1.204     joerg {
   1558      1.204     joerg 	pid_t result;
   1559      1.204     joerg 
   1560      1.212  riastrad 	_rtld_shared_enter();
   1561      1.204     joerg 	result = __fork();
   1562      1.205     joerg 	if (result == -1)
   1563      1.205     joerg 		*my_errno = errno;
   1564      1.212  riastrad 	_rtld_shared_exit();
   1565      1.204     joerg 
   1566      1.204     joerg 	return result;
   1567      1.204     joerg }
   1568      1.204     joerg 
   1569        1.1       cgd /*
   1570        1.1       cgd  * Error reporting function.  Use it like printf.  If formats the message
   1571        1.1       cgd  * into a buffer, and sets things up so that the next call to dlerror()
   1572        1.1       cgd  * will return the message.
   1573        1.1       cgd  */
   1574        1.1       cgd void
   1575       1.15  christos _rtld_error(const char *fmt,...)
   1576        1.1       cgd {
   1577       1.15  christos 	static char     buf[512];
   1578       1.15  christos 	va_list         ap;
   1579       1.49       wiz 
   1580       1.15  christos 	va_start(ap, fmt);
   1581       1.15  christos 	xvsnprintf(buf, sizeof buf, fmt, ap);
   1582  1.212.2.2    martin 	dbg(("%s: %s", __func__, buf));
   1583       1.15  christos 	error_message = buf;
   1584       1.15  christos 	va_end(ap);
   1585        1.1       cgd }
   1586       1.14        pk 
   1587        1.1       cgd void
   1588       1.98     skrll _rtld_debug_state(void)
   1589        1.1       cgd {
   1590      1.175     skrll #if defined(__hppa__)
   1591      1.175     skrll 	__asm volatile("nop" ::: "memory");
   1592      1.175     skrll #endif
   1593       1.94    simonb 
   1594      1.157     joerg 	/* Prevent optimizer from removing calls to this function */
   1595      1.157     joerg 	__insn_barrier();
   1596        1.1       cgd }
   1597        1.1       cgd 
   1598        1.1       cgd void
   1599       1.98     skrll _rtld_linkmap_add(Obj_Entry *obj)
   1600        1.1       cgd {
   1601       1.15  christos 	struct link_map *l = &obj->linkmap;
   1602       1.15  christos 	struct link_map *prev;
   1603        1.1       cgd 
   1604       1.15  christos 	obj->linkmap.l_name = obj->path;
   1605       1.68   mycroft 	obj->linkmap.l_addr = obj->relocbase;
   1606       1.15  christos 	obj->linkmap.l_ld = obj->dynamic;
   1607        1.6    mhitch #ifdef __mips__
   1608       1.72   mycroft 	/* XXX This field is not standard and will be removed eventually. */
   1609       1.15  christos 	obj->linkmap.l_offs = obj->relocbase;
   1610        1.6    mhitch #endif
   1611        1.1       cgd 
   1612       1.15  christos 	if (_rtld_debug.r_map == NULL) {
   1613       1.15  christos 		_rtld_debug.r_map = l;
   1614       1.15  christos 		return;
   1615       1.15  christos 	}
   1616      1.109     skrll 
   1617      1.109     skrll 	/*
   1618      1.109     skrll 	 * Scan to the end of the list, but not past the entry for the
   1619      1.109     skrll 	 * dynamic linker, which we want to keep at the very end.
   1620      1.109     skrll 	 */
   1621      1.109     skrll 	for (prev = _rtld_debug.r_map;
   1622      1.109     skrll 	    prev->l_next != NULL && prev->l_next != &_rtld_objself.linkmap;
   1623      1.109     skrll 	    prev = prev->l_next);
   1624      1.109     skrll 
   1625       1.15  christos 	l->l_prev = prev;
   1626      1.109     skrll 	l->l_next = prev->l_next;
   1627      1.109     skrll 	if (l->l_next != NULL)
   1628      1.109     skrll 		l->l_next->l_prev = l;
   1629       1.15  christos 	prev->l_next = l;
   1630        1.1       cgd }
   1631        1.1       cgd 
   1632        1.1       cgd void
   1633       1.98     skrll _rtld_linkmap_delete(Obj_Entry *obj)
   1634        1.1       cgd {
   1635       1.15  christos 	struct link_map *l = &obj->linkmap;
   1636        1.1       cgd 
   1637       1.15  christos 	if (l->l_prev == NULL) {
   1638       1.15  christos 		if ((_rtld_debug.r_map = l->l_next) != NULL)
   1639       1.15  christos 			l->l_next->l_prev = NULL;
   1640       1.15  christos 		return;
   1641       1.15  christos 	}
   1642       1.15  christos 	if ((l->l_prev->l_next = l->l_next) != NULL)
   1643       1.15  christos 		l->l_next->l_prev = l->l_prev;
   1644       1.25   mycroft }
   1645       1.25   mycroft 
   1646       1.25   mycroft static Obj_Entry *
   1647       1.25   mycroft _rtld_obj_from_addr(const void *addr)
   1648       1.25   mycroft {
   1649       1.25   mycroft 	Obj_Entry *obj;
   1650      1.165     skrll 
   1651       1.25   mycroft 	for (obj = _rtld_objlist;  obj != NULL;  obj = obj->next) {
   1652       1.25   mycroft 		if (addr < (void *) obj->mapbase)
   1653       1.25   mycroft 			continue;
   1654       1.67   mycroft 		if (addr < (void *) (obj->mapbase + obj->mapsize))
   1655       1.25   mycroft 			return obj;
   1656       1.25   mycroft 	}
   1657       1.25   mycroft 	return NULL;
   1658       1.25   mycroft }
   1659       1.25   mycroft 
   1660       1.25   mycroft static void
   1661      1.117        ad _rtld_objlist_clear(Objlist *list)
   1662      1.117        ad {
   1663      1.117        ad 	while (!SIMPLEQ_EMPTY(list)) {
   1664      1.117        ad 		Objlist_Entry* elm = SIMPLEQ_FIRST(list);
   1665      1.117        ad 		SIMPLEQ_REMOVE_HEAD(list, link);
   1666      1.117        ad 		xfree(elm);
   1667      1.117        ad 	}
   1668      1.117        ad }
   1669      1.117        ad 
   1670      1.117        ad static void
   1671       1.98     skrll _rtld_objlist_remove(Objlist *list, Obj_Entry *obj)
   1672       1.25   mycroft {
   1673       1.25   mycroft 	Objlist_Entry *elm;
   1674      1.165     skrll 
   1675       1.25   mycroft 	if ((elm = _rtld_objlist_find(list, obj)) != NULL) {
   1676       1.50     lukem 		SIMPLEQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
   1677      1.116        ad 		xfree(elm);
   1678       1.25   mycroft 	}
   1679        1.1       cgd }
   1680      1.141     joerg 
   1681      1.141     joerg #define	RTLD_EXCLUSIVE_MASK	0x80000000U
   1682      1.141     joerg static volatile unsigned int _rtld_mutex;
   1683      1.141     joerg static volatile unsigned int _rtld_waiter_exclusive;
   1684      1.141     joerg static volatile unsigned int _rtld_waiter_shared;
   1685      1.141     joerg 
   1686      1.141     joerg void
   1687      1.141     joerg _rtld_shared_enter(void)
   1688      1.141     joerg {
   1689      1.141     joerg 	unsigned int cur;
   1690      1.141     joerg 	lwpid_t waiter, self = 0;
   1691      1.141     joerg 
   1692      1.141     joerg 	for (;;) {
   1693      1.141     joerg 		cur = _rtld_mutex;
   1694      1.141     joerg 		/*
   1695      1.141     joerg 		 * First check if we are currently not exclusively locked.
   1696      1.141     joerg 		 */
   1697      1.141     joerg 		if ((cur & RTLD_EXCLUSIVE_MASK) == 0) {
   1698      1.141     joerg 			/* Yes, so increment use counter */
   1699      1.141     joerg 			if (atomic_cas_uint(&_rtld_mutex, cur, cur + 1) != cur)
   1700      1.141     joerg 				continue;
   1701      1.211  riastrad 			membar_acquire();
   1702      1.141     joerg 			return;
   1703      1.141     joerg 		}
   1704      1.141     joerg 		/*
   1705      1.141     joerg 		 * Someone has an exclusive lock.  Puts us on the waiter list.
   1706      1.141     joerg 		 */
   1707      1.141     joerg 		if (!self)
   1708      1.141     joerg 			self = _lwp_self();
   1709      1.141     joerg 		if (cur == (self | RTLD_EXCLUSIVE_MASK)) {
   1710      1.141     joerg 			if (_rtld_mutex_may_recurse)
   1711      1.141     joerg 				return;
   1712      1.200  christos 			_rtld_error("%s: dead lock detected", __func__);
   1713      1.141     joerg 			_rtld_die();
   1714      1.141     joerg 		}
   1715      1.141     joerg 		waiter = atomic_swap_uint(&_rtld_waiter_shared, self);
   1716      1.141     joerg 		/*
   1717      1.141     joerg 		 * Check for race against _rtld_exclusive_exit before sleeping.
   1718      1.141     joerg 		 */
   1719      1.177      yamt 		membar_sync();
   1720      1.141     joerg 		if ((_rtld_mutex & RTLD_EXCLUSIVE_MASK) ||
   1721      1.141     joerg 		    _rtld_waiter_exclusive)
   1722      1.172     joerg 			_lwp_park(CLOCK_REALTIME, 0, NULL, 0,
   1723      1.172     joerg 			    __UNVOLATILE(&_rtld_mutex), NULL);
   1724      1.141     joerg 		/* Try to remove us from the waiter list. */
   1725      1.141     joerg 		atomic_cas_uint(&_rtld_waiter_shared, self, 0);
   1726      1.141     joerg 		if (waiter)
   1727      1.141     joerg 			_lwp_unpark(waiter, __UNVOLATILE(&_rtld_mutex));
   1728      1.141     joerg 	}
   1729      1.141     joerg }
   1730      1.141     joerg 
   1731      1.141     joerg void
   1732      1.141     joerg _rtld_shared_exit(void)
   1733      1.141     joerg {
   1734      1.141     joerg 	lwpid_t waiter;
   1735      1.141     joerg 
   1736      1.141     joerg 	/*
   1737      1.141     joerg 	 * Shared lock taken after an exclusive lock.
   1738      1.141     joerg 	 * Just assume this is a partial recursion.
   1739      1.141     joerg 	 */
   1740      1.141     joerg 	if (_rtld_mutex & RTLD_EXCLUSIVE_MASK)
   1741      1.141     joerg 		return;
   1742      1.141     joerg 
   1743      1.141     joerg 	/*
   1744      1.141     joerg 	 * Wakeup LWPs waiting for an exclusive lock if this is the last
   1745      1.141     joerg 	 * LWP on the shared lock.
   1746      1.141     joerg 	 */
   1747      1.211  riastrad 	membar_release();
   1748      1.141     joerg 	if (atomic_dec_uint_nv(&_rtld_mutex))
   1749      1.141     joerg 		return;
   1750      1.177      yamt 	membar_sync();
   1751      1.141     joerg 	if ((waiter = _rtld_waiter_exclusive) != 0)
   1752      1.141     joerg 		_lwp_unpark(waiter, __UNVOLATILE(&_rtld_mutex));
   1753      1.141     joerg }
   1754      1.141     joerg 
   1755      1.141     joerg void
   1756      1.148     joerg _rtld_exclusive_enter(sigset_t *mask)
   1757      1.141     joerg {
   1758      1.141     joerg 	lwpid_t waiter, self = _lwp_self();
   1759      1.141     joerg 	unsigned int locked_value = (unsigned int)self | RTLD_EXCLUSIVE_MASK;
   1760      1.141     joerg 	unsigned int cur;
   1761      1.148     joerg 	sigset_t blockmask;
   1762      1.148     joerg 
   1763      1.148     joerg 	sigfillset(&blockmask);
   1764      1.153  christos 	sigdelset(&blockmask, SIGTRAP);	/* Allow the debugger */
   1765      1.148     joerg 	sigprocmask(SIG_BLOCK, &blockmask, mask);
   1766      1.141     joerg 
   1767      1.141     joerg 	for (;;) {
   1768      1.177      yamt 		if (atomic_cas_uint(&_rtld_mutex, 0, locked_value) == 0) {
   1769      1.211  riastrad 			membar_acquire();
   1770      1.141     joerg 			break;
   1771      1.177      yamt 		}
   1772      1.141     joerg 		waiter = atomic_swap_uint(&_rtld_waiter_exclusive, self);
   1773      1.177      yamt 		membar_sync();
   1774      1.141     joerg 		cur = _rtld_mutex;
   1775      1.141     joerg 		if (cur == locked_value) {
   1776      1.200  christos 			_rtld_error("%s: dead lock detected", __func__);
   1777      1.141     joerg 			_rtld_die();
   1778      1.141     joerg 		}
   1779      1.141     joerg 		if (cur)
   1780      1.172     joerg 			_lwp_park(CLOCK_REALTIME, 0, NULL, 0,
   1781      1.172     joerg 			    __UNVOLATILE(&_rtld_mutex), NULL);
   1782      1.141     joerg 		atomic_cas_uint(&_rtld_waiter_exclusive, self, 0);
   1783      1.141     joerg 		if (waiter)
   1784      1.141     joerg 			_lwp_unpark(waiter, __UNVOLATILE(&_rtld_mutex));
   1785      1.141     joerg 	}
   1786      1.141     joerg }
   1787      1.141     joerg 
   1788      1.141     joerg void
   1789      1.148     joerg _rtld_exclusive_exit(sigset_t *mask)
   1790      1.141     joerg {
   1791      1.141     joerg 	lwpid_t waiter;
   1792      1.141     joerg 
   1793      1.211  riastrad 	membar_release();
   1794      1.141     joerg 	_rtld_mutex = 0;
   1795      1.177      yamt 	membar_sync();
   1796      1.141     joerg 	if ((waiter = _rtld_waiter_exclusive) != 0)
   1797      1.141     joerg 		_lwp_unpark(waiter, __UNVOLATILE(&_rtld_mutex));
   1798      1.141     joerg 
   1799      1.141     joerg 	if ((waiter = _rtld_waiter_shared) != 0)
   1800      1.141     joerg 		_lwp_unpark(waiter, __UNVOLATILE(&_rtld_mutex));
   1801      1.141     joerg 
   1802      1.148     joerg 	sigprocmask(SIG_SETMASK, mask, NULL);
   1803      1.141     joerg }
   1804      1.195  christos 
   1805      1.195  christos int
   1806      1.195  christos _rtld_relro(const Obj_Entry *obj, bool wantmain)
   1807      1.195  christos {
   1808      1.195  christos #ifdef GNU_RELRO
   1809      1.203   thorpej 	/*
   1810      1.203   thorpej 	 * If our VM page size is larger than the page size used by the
   1811      1.203   thorpej 	 * linker when laying out the object, we could end up making data
   1812      1.203   thorpej 	 * read-only that is unintended.  Detect and avoid this situation.
   1813      1.203   thorpej 	 * It may mean we are unable to protect everything we'd like, but
   1814      1.203   thorpej 	 * it's better than crashing.
   1815      1.203   thorpej 	 */
   1816      1.203   thorpej 	uintptr_t relro_end = (uintptr_t)obj->relro_page + obj->relro_size;
   1817      1.203   thorpej 	uintptr_t relro_start = round_down((uintptr_t)obj->relro_page);
   1818      1.203   thorpej 	assert(relro_end >= relro_start);
   1819      1.203   thorpej 	size_t relro_size = round_down(relro_end) - relro_start;
   1820      1.203   thorpej 
   1821      1.203   thorpej 	if (relro_size == 0)
   1822      1.195  christos 		return 0;
   1823      1.195  christos 	if (wantmain != (obj ==_rtld_objmain))
   1824      1.195  christos 		return 0;
   1825      1.195  christos 
   1826      1.203   thorpej 	dbg(("RELRO %s %p %zx\n", obj->path, (void *)relro_start, relro_size));
   1827      1.203   thorpej 	if (mprotect((void *)relro_start, relro_size, PROT_READ) == -1) {
   1828      1.195  christos 		_rtld_error("%s: Cannot enforce relro " "protection: %s",
   1829      1.195  christos 		    obj->path, xstrerror(errno));
   1830      1.195  christos 		return -1;
   1831      1.195  christos 	}
   1832      1.195  christos #endif
   1833      1.195  christos 	return 0;
   1834      1.195  christos }
   1835