1641 lines
40 KiB
C
1641 lines
40 KiB
C
/* $NetBSD: rtld.c,v 1.159 2012/10/01 03:03:46 riastradh Exp $ */
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/*
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* Copyright 1996 John D. Polstra.
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* Copyright 1996 Matt Thomas <matt@3am-software.com>
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* Copyright 2002 Charles M. Hannum <root@ihack.net>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by John Polstra.
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* 4. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* Dynamic linker for ELF.
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*
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* John Polstra <jdp@polstra.com>.
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*/
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#ifdef __minix
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#define munmap minix_munmap
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#endif
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#include <sys/cdefs.h>
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#ifndef lint
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__RCSID("$NetBSD: rtld.c,v 1.159 2012/10/01 03:03:46 riastradh Exp $");
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#endif /* not lint */
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#include <sys/param.h>
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#include <sys/atomic.h>
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#include <sys/mman.h>
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#include <err.h>
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#include <errno.h>
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#include <fcntl.h>
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#if !defined(__minix)
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#include <lwp.h>
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#endif /* !defined(__minix) */
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <dirent.h>
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#include <ctype.h>
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#include <dlfcn.h>
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#include "debug.h"
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#include "rtld.h"
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#if !defined(lint)
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#include "sysident.h"
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#endif
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/*
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* Function declarations.
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*/
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static void _rtld_init(caddr_t, caddr_t, const char *);
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static void _rtld_exit(void);
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Elf_Addr _rtld(Elf_Addr *, Elf_Addr);
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/*
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* Data declarations.
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*/
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static char *error_message; /* Message for dlopen(), or NULL */
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struct r_debug _rtld_debug; /* for GDB; */
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bool _rtld_trust; /* False for setuid and setgid programs */
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Obj_Entry *_rtld_objlist; /* Head of linked list of shared objects */
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Obj_Entry **_rtld_objtail; /* Link field of last object in list */
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Obj_Entry *_rtld_objmain; /* The main program shared object */
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Obj_Entry _rtld_objself; /* The dynamic linker shared object */
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u_int _rtld_objcount; /* Number of objects in _rtld_objlist */
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u_int _rtld_objloads; /* Number of objects loaded in _rtld_objlist */
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u_int _rtld_objgen; /* Generation count for _rtld_objlist */
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const char _rtld_path[] = _PATH_RTLD;
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/* Initialize a fake symbol for resolving undefined weak references. */
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Elf_Sym _rtld_sym_zero = {
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.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE),
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.st_shndx = SHN_ABS,
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};
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size_t _rtld_pagesz; /* Page size, as provided by kernel */
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Search_Path *_rtld_default_paths;
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Search_Path *_rtld_paths;
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Library_Xform *_rtld_xforms;
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static void *auxinfo;
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/*
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* Global declarations normally provided by crt0.
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*/
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char *__progname;
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char **environ;
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#if !defined(__minix)
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static volatile bool _rtld_mutex_may_recurse;
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#endif /* !defined(__minix) */
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#if defined(RTLD_DEBUG)
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#ifndef __sh__
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extern Elf_Addr _GLOBAL_OFFSET_TABLE_[];
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#else /* 32-bit SuperH */
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register Elf_Addr *_GLOBAL_OFFSET_TABLE_ asm("r12");
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#endif
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#endif /* RTLD_DEBUG */
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extern Elf_Dyn _DYNAMIC;
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static void _rtld_call_fini_functions(sigset_t *, int);
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static void _rtld_call_init_functions(sigset_t *);
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static void _rtld_initlist_visit(Objlist *, Obj_Entry *, int);
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static void _rtld_initlist_tsort(Objlist *, int);
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static Obj_Entry *_rtld_dlcheck(void *);
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static void _rtld_init_dag(Obj_Entry *);
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static void _rtld_init_dag1(Obj_Entry *, Obj_Entry *);
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static void _rtld_objlist_remove(Objlist *, Obj_Entry *);
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static void _rtld_objlist_clear(Objlist *);
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static void _rtld_unload_object(sigset_t *, Obj_Entry *, bool);
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static void _rtld_unref_dag(Obj_Entry *);
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static Obj_Entry *_rtld_obj_from_addr(const void *);
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static inline void
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_rtld_call_initfini_function(fptr_t func, sigset_t *mask)
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{
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_rtld_exclusive_exit(mask);
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(*func)();
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_rtld_exclusive_enter(mask);
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}
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static void
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_rtld_call_fini_function(Obj_Entry *obj, sigset_t *mask, u_int cur_objgen)
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{
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if (obj->fini_arraysz == 0 && (obj->fini == NULL || obj->fini_called)) {
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return;
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}
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if (obj->fini != NULL && !obj->fini_called) {
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dbg (("calling fini function %s at %p%s", obj->path,
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(void *)obj->fini,
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obj->z_initfirst ? " (DF_1_INITFIRST)" : ""));
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obj->fini_called = 1;
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_rtld_call_initfini_function(obj->fini, mask);
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}
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#ifdef HAVE_INITFINI_ARRAY
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/*
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* Now process the fini_array if it exists. Simply go from
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* start to end. We need to make restartable so just advance
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* the array pointer and decrement the size each time through
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* the loop.
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*/
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while (obj->fini_arraysz > 0 && _rtld_objgen == cur_objgen) {
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fptr_t fini = *obj->fini_array++;
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obj->fini_arraysz--;
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dbg (("calling fini array function %s at %p%s", obj->path,
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(void *)fini,
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obj->z_initfirst ? " (DF_1_INITFIRST)" : ""));
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_rtld_call_initfini_function(fini, mask);
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}
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#endif /* HAVE_INITFINI_ARRAY */
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}
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static void
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_rtld_call_fini_functions(sigset_t *mask, int force)
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{
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Objlist_Entry *elm;
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Objlist finilist;
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u_int cur_objgen;
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dbg(("_rtld_call_fini_functions(%d)", force));
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restart:
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cur_objgen = ++_rtld_objgen;
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SIMPLEQ_INIT(&finilist);
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_rtld_initlist_tsort(&finilist, 1);
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/* First pass: objects _not_ marked with DF_1_INITFIRST. */
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SIMPLEQ_FOREACH(elm, &finilist, link) {
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Obj_Entry * const obj = elm->obj;
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if (!obj->z_initfirst) {
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if (obj->refcount > 0 && !force) {
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continue;
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}
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/*
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* XXX This can race against a concurrent dlclose().
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* XXX In that case, the object could be unmapped before
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* XXX the fini() call or the fini_array has completed.
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*/
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_rtld_call_fini_function(obj, mask, cur_objgen);
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if (_rtld_objgen != cur_objgen) {
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dbg(("restarting fini iteration"));
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_rtld_objlist_clear(&finilist);
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goto restart;
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}
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}
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}
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/* Second pass: objects marked with DF_1_INITFIRST. */
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SIMPLEQ_FOREACH(elm, &finilist, link) {
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Obj_Entry * const obj = elm->obj;
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if (obj->refcount > 0 && !force) {
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continue;
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}
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/* XXX See above for the race condition here */
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_rtld_call_fini_function(obj, mask, cur_objgen);
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if (_rtld_objgen != cur_objgen) {
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dbg(("restarting fini iteration"));
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_rtld_objlist_clear(&finilist);
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goto restart;
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}
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}
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_rtld_objlist_clear(&finilist);
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}
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static void
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_rtld_call_init_function(Obj_Entry *obj, sigset_t *mask, u_int cur_objgen)
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{
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if (obj->init_arraysz == 0 && (obj->init_called || obj->init == NULL)) {
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return;
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}
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if (!obj->init_called && obj->init != NULL) {
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dbg (("calling init function %s at %p%s",
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obj->path, (void *)obj->init,
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obj->z_initfirst ? " (DF_1_INITFIRST)" : ""));
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obj->init_called = 1;
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_rtld_call_initfini_function(obj->init, mask);
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}
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#ifdef HAVE_INITFINI_ARRAY
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/*
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* Now process the init_array if it exists. Simply go from
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* start to end. We need to make restartable so just advance
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* the array pointer and decrement the size each time through
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* the loop.
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*/
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while (obj->init_arraysz > 0 && _rtld_objgen == cur_objgen) {
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fptr_t init = *obj->init_array++;
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obj->init_arraysz--;
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dbg (("calling init_array function %s at %p%s",
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obj->path, (void *)init,
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obj->z_initfirst ? " (DF_1_INITFIRST)" : ""));
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_rtld_call_initfini_function(init, mask);
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}
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#endif /* HAVE_INITFINI_ARRAY */
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}
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static void
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_rtld_call_init_functions(sigset_t *mask)
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{
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Objlist_Entry *elm;
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Objlist initlist;
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u_int cur_objgen;
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dbg(("_rtld_call_init_functions()"));
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restart:
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cur_objgen = ++_rtld_objgen;
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SIMPLEQ_INIT(&initlist);
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_rtld_initlist_tsort(&initlist, 0);
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/* First pass: objects marked with DF_1_INITFIRST. */
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SIMPLEQ_FOREACH(elm, &initlist, link) {
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Obj_Entry * const obj = elm->obj;
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if (obj->z_initfirst) {
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_rtld_call_init_function(obj, mask, cur_objgen);
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if (_rtld_objgen != cur_objgen) {
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dbg(("restarting init iteration"));
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_rtld_objlist_clear(&initlist);
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goto restart;
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}
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}
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}
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/* Second pass: all other objects. */
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SIMPLEQ_FOREACH(elm, &initlist, link) {
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_rtld_call_init_function(elm->obj, mask, cur_objgen);
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if (_rtld_objgen != cur_objgen) {
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dbg(("restarting init iteration"));
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_rtld_objlist_clear(&initlist);
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goto restart;
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}
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}
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_rtld_objlist_clear(&initlist);
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}
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/*
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* Initialize the dynamic linker. The argument is the address at which
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* the dynamic linker has been mapped into memory. The primary task of
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* this function is to create an Obj_Entry for the dynamic linker and
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* to resolve the PLT relocation for platforms that need it (those that
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* define __HAVE_FUNCTION_DESCRIPTORS
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*/
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static void
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_rtld_init(caddr_t mapbase, caddr_t relocbase, const char *execname)
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{
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/* Conjure up an Obj_Entry structure for the dynamic linker. */
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_rtld_objself.path = __UNCONST(_rtld_path);
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_rtld_objself.pathlen = sizeof(_rtld_path)-1;
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_rtld_objself.rtld = true;
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_rtld_objself.mapbase = mapbase;
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_rtld_objself.relocbase = relocbase;
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_rtld_objself.dynamic = (Elf_Dyn *) &_DYNAMIC;
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_rtld_objself.strtab = "_rtld_sym_zero";
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/*
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* Set value to -relocbase so that
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*
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* _rtld_objself.relocbase + _rtld_sym_zero.st_value == 0
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*
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* This allows unresolved references to weak symbols to be computed
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* to a value of 0.
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*/
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_rtld_sym_zero.st_value = -(uintptr_t)relocbase;
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_rtld_digest_dynamic(_rtld_path, &_rtld_objself);
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assert(!_rtld_objself.needed);
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#if !defined(__hppa__)
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assert(!_rtld_objself.pltrel && !_rtld_objself.pltrela);
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#else
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_rtld_relocate_plt_objects(&_rtld_objself);
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#endif
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#if !defined(__mips__) && !defined(__hppa__) && !defined(HAVE_GOLD)
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assert(!_rtld_objself.pltgot);
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#endif
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#if !defined(__arm__) && !defined(__mips__) && !defined(__sh__)
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/* ARM, MIPS and SH{3,5} have a bogus DT_TEXTREL. */
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assert(!_rtld_objself.textrel);
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#endif
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_rtld_add_paths(execname, &_rtld_default_paths,
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RTLD_DEFAULT_LIBRARY_PATH);
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#ifdef RTLD_ARCH_SUBDIR
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_rtld_add_paths(execname, &_rtld_default_paths,
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RTLD_DEFAULT_LIBRARY_PATH "/" RTLD_ARCH_SUBDIR);
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#endif
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/*
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* Set up the _rtld_objlist pointer, so that rtld symbols can be found.
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*/
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_rtld_objlist = &_rtld_objself;
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/* Make the object list empty again. */
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_rtld_objlist = NULL;
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_rtld_objtail = &_rtld_objlist;
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_rtld_objcount = 0;
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_rtld_debug.r_brk = _rtld_debug_state;
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_rtld_debug.r_state = RT_CONSISTENT;
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}
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/*
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* Cleanup procedure. It will be called (by the atexit() mechanism) just
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* before the process exits.
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*/
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static void
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_rtld_exit(void)
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{
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sigset_t mask;
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dbg(("rtld_exit()"));
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_rtld_exclusive_enter(&mask);
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_rtld_call_fini_functions(&mask, 1);
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_rtld_exclusive_exit(&mask);
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}
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__dso_public void *
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_dlauxinfo(void)
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{
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return auxinfo;
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}
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/*
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* Main entry point for dynamic linking. The argument is the stack
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* pointer. The stack is expected to be laid out as described in the
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* SVR4 ABI specification, Intel 386 Processor Supplement. Specifically,
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* the stack pointer points to a word containing ARGC. Following that
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* in the stack is a null-terminated sequence of pointers to argument
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* strings. Then comes a null-terminated sequence of pointers to
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* environment strings. Finally, there is a sequence of "auxiliary
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* vector" entries.
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*
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* This function returns the entry point for the main program, the dynamic
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* linker's exit procedure in sp[0], and a pointer to the main object in
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* sp[1].
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*/
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Elf_Addr
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_rtld(Elf_Addr *sp, Elf_Addr relocbase)
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{
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const AuxInfo *pAUX_base, *pAUX_entry, *pAUX_execfd, *pAUX_phdr,
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*pAUX_phent, *pAUX_phnum, *pAUX_euid, *pAUX_egid,
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*pAUX_ruid, *pAUX_rgid;
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const AuxInfo *pAUX_pagesz;
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char **env, **oenvp;
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const AuxInfo *auxp;
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Obj_Entry *obj;
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Elf_Addr *const osp = sp;
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bool bind_now = 0;
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const char *ld_bind_now, *ld_preload, *ld_library_path;
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const char **argv;
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const char *execname;
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long argc;
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const char **real___progname;
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const Obj_Entry **real___mainprog_obj;
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char ***real_environ;
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sigset_t mask;
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#ifdef DEBUG
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const char *ld_debug;
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#endif
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#ifdef RTLD_DEBUG
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int i = 0;
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#endif
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/*
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* On entry, the dynamic linker itself has not been relocated yet.
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* Be very careful not to reference any global data until after
|
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* _rtld_init has returned. It is OK to reference file-scope statics
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* and string constants, and to call static and global functions.
|
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*/
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/* Find the auxiliary vector on the stack. */
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/* first Elf_Word reserved to address of exit routine */
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#if defined(RTLD_DEBUG)
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debug = 1;
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dbg(("sp = %p, argc = %ld, argv = %p <%s> relocbase %p", sp,
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(long)sp[2], &sp[3], (char *) sp[3], (void *)relocbase));
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#if 0
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dbg(("got is at %p, dynamic is at %p", _GLOBAL_OFFSET_TABLE_,
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&_DYNAMIC));
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#endif
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dbg(("_ctype_ is %p", _ctype_));
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#endif
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sp += 2; /* skip over return argument space */
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argv = (const char **) &sp[1];
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argc = *(long *)sp;
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sp += 2 + argc; /* Skip over argc, arguments, and NULL
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* terminator */
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env = (char **) sp;
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while (*sp++ != 0) { /* Skip over environment, and NULL terminator */
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#if defined(RTLD_DEBUG)
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dbg(("env[%d] = %p %s", i++, (void *)sp[-1], (char *)sp[-1]));
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#endif
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}
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auxinfo = (AuxInfo *) sp;
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pAUX_base = pAUX_entry = pAUX_execfd = NULL;
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pAUX_phdr = pAUX_phent = pAUX_phnum = NULL;
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pAUX_euid = pAUX_ruid = pAUX_egid = pAUX_rgid = NULL;
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pAUX_pagesz = NULL;
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execname = NULL;
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|
|
/* Digest the auxiliary vector. */
|
|
for (auxp = auxinfo; auxp->a_type != AT_NULL; ++auxp) {
|
|
switch (auxp->a_type) {
|
|
case AT_BASE:
|
|
pAUX_base = auxp;
|
|
break;
|
|
case AT_ENTRY:
|
|
pAUX_entry = auxp;
|
|
break;
|
|
case AT_EXECFD:
|
|
pAUX_execfd = auxp;
|
|
break;
|
|
case AT_PHDR:
|
|
pAUX_phdr = auxp;
|
|
break;
|
|
case AT_PHENT:
|
|
pAUX_phent = auxp;
|
|
break;
|
|
case AT_PHNUM:
|
|
pAUX_phnum = auxp;
|
|
break;
|
|
#ifdef AT_EUID
|
|
case AT_EUID:
|
|
pAUX_euid = auxp;
|
|
break;
|
|
case AT_RUID:
|
|
pAUX_ruid = auxp;
|
|
break;
|
|
case AT_EGID:
|
|
pAUX_egid = auxp;
|
|
break;
|
|
case AT_RGID:
|
|
pAUX_rgid = auxp;
|
|
break;
|
|
#endif
|
|
#ifdef AT_SUN_EXECNAME
|
|
case AT_SUN_EXECNAME:
|
|
execname = (const char *)(const void *)auxp->a_v;
|
|
break;
|
|
#endif
|
|
case AT_PAGESZ:
|
|
pAUX_pagesz = auxp;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* Initialize and relocate ourselves. */
|
|
if (pAUX_base == NULL) {
|
|
_rtld_error("Bad pAUX_base");
|
|
_rtld_die();
|
|
}
|
|
assert(pAUX_pagesz != NULL);
|
|
_rtld_pagesz = (int)pAUX_pagesz->a_v;
|
|
_rtld_init((caddr_t)pAUX_base->a_v, (caddr_t)relocbase, execname);
|
|
|
|
__progname = _rtld_objself.path;
|
|
environ = env;
|
|
|
|
_rtld_trust = ((pAUX_euid ? (uid_t)pAUX_euid->a_v : geteuid()) ==
|
|
(pAUX_ruid ? (uid_t)pAUX_ruid->a_v : getuid())) &&
|
|
((pAUX_egid ? (gid_t)pAUX_egid->a_v : getegid()) ==
|
|
(pAUX_rgid ? (gid_t)pAUX_rgid->a_v : getgid()));
|
|
|
|
#ifdef DEBUG
|
|
ld_debug = NULL;
|
|
#endif
|
|
ld_bind_now = NULL;
|
|
ld_library_path = NULL;
|
|
ld_preload = NULL;
|
|
/*
|
|
* Inline avoid using normal getenv/unsetenv here as the libc
|
|
* code is quite a bit more complicated.
|
|
*/
|
|
for (oenvp = env; *env != NULL; ++env) {
|
|
static const char bind_var[] = "LD_BIND_NOW=";
|
|
static const char debug_var[] = "LD_DEBUG=";
|
|
static const char path_var[] = "LD_LIBRARY_PATH=";
|
|
static const char preload_var[] = "LD_PRELOAD=";
|
|
#define LEN(x) (sizeof(x) - 1)
|
|
|
|
if ((*env)[0] != 'L' || (*env)[1] != 'D') {
|
|
/*
|
|
* Special case to skip most entries without
|
|
* the more expensive calls to strncmp.
|
|
*/
|
|
*oenvp++ = *env;
|
|
} else if (strncmp(*env, debug_var, LEN(debug_var)) == 0) {
|
|
if (_rtld_trust) {
|
|
#ifdef DEBUG
|
|
ld_debug = *env + LEN(debug_var);
|
|
#endif
|
|
*oenvp++ = *env;
|
|
}
|
|
} else if (strncmp(*env, bind_var, LEN(bind_var)) == 0) {
|
|
ld_bind_now = *env + LEN(bind_var);
|
|
} else if (strncmp(*env, path_var, LEN(path_var)) == 0) {
|
|
if (_rtld_trust) {
|
|
ld_library_path = *env + LEN(path_var);
|
|
*oenvp++ = *env;
|
|
}
|
|
} else if (strncmp(*env, preload_var, LEN(preload_var)) == 0) {
|
|
if (_rtld_trust) {
|
|
ld_preload = *env + LEN(preload_var);
|
|
*oenvp++ = *env;
|
|
}
|
|
} else {
|
|
*oenvp++ = *env;
|
|
}
|
|
#undef LEN
|
|
}
|
|
*oenvp++ = NULL;
|
|
|
|
if (ld_bind_now != NULL && *ld_bind_now != '\0')
|
|
bind_now = true;
|
|
if (_rtld_trust) {
|
|
#ifdef DEBUG
|
|
#ifdef RTLD_DEBUG
|
|
debug = 0;
|
|
#endif
|
|
if (ld_debug != NULL && *ld_debug != '\0')
|
|
debug = 1;
|
|
#endif
|
|
_rtld_add_paths(execname, &_rtld_paths, ld_library_path);
|
|
} else {
|
|
execname = NULL;
|
|
}
|
|
_rtld_process_hints(execname, &_rtld_paths, &_rtld_xforms,
|
|
_PATH_LD_HINTS);
|
|
dbg(("dynamic linker is initialized, mapbase=%p, relocbase=%p",
|
|
_rtld_objself.mapbase, _rtld_objself.relocbase));
|
|
|
|
/*
|
|
* Load the main program, or process its program header if it is
|
|
* already loaded.
|
|
*/
|
|
if (pAUX_execfd != NULL) { /* Load the main program. */
|
|
int fd = pAUX_execfd->a_v;
|
|
const char *obj_name = argv[0] ? argv[0] : "main program";
|
|
dbg(("loading main program"));
|
|
_rtld_objmain = _rtld_map_object(obj_name, fd, NULL);
|
|
close(fd);
|
|
if (_rtld_objmain == NULL)
|
|
_rtld_die();
|
|
} else { /* Main program already loaded. */
|
|
const Elf_Phdr *phdr;
|
|
int phnum;
|
|
caddr_t entry;
|
|
|
|
dbg(("processing main program's program header"));
|
|
assert(pAUX_phdr != NULL);
|
|
phdr = (const Elf_Phdr *) pAUX_phdr->a_v;
|
|
assert(pAUX_phnum != NULL);
|
|
phnum = pAUX_phnum->a_v;
|
|
assert(pAUX_phent != NULL);
|
|
assert(pAUX_phent->a_v == sizeof(Elf_Phdr));
|
|
assert(pAUX_entry != NULL);
|
|
entry = (caddr_t) pAUX_entry->a_v;
|
|
_rtld_objmain = _rtld_digest_phdr(phdr, phnum, entry);
|
|
_rtld_objmain->path = xstrdup(argv[0] ? argv[0] :
|
|
"main program");
|
|
_rtld_objmain->pathlen = strlen(_rtld_objmain->path);
|
|
}
|
|
|
|
_rtld_objmain->mainprog = true;
|
|
|
|
/*
|
|
* Get the actual dynamic linker pathname from the executable if
|
|
* possible. (It should always be possible.) That ensures that
|
|
* gdb will find the right dynamic linker even if a non-standard
|
|
* one is being used.
|
|
*/
|
|
if (_rtld_objmain->interp != NULL &&
|
|
strcmp(_rtld_objmain->interp, _rtld_objself.path) != 0)
|
|
_rtld_objself.path = xstrdup(_rtld_objmain->interp);
|
|
dbg(("actual dynamic linker is %s", _rtld_objself.path));
|
|
|
|
_rtld_digest_dynamic(execname, _rtld_objmain);
|
|
|
|
/* Link the main program into the list of objects. */
|
|
*_rtld_objtail = _rtld_objmain;
|
|
_rtld_objtail = &_rtld_objmain->next;
|
|
_rtld_objcount++;
|
|
_rtld_objloads++;
|
|
|
|
_rtld_linkmap_add(_rtld_objmain);
|
|
_rtld_linkmap_add(&_rtld_objself);
|
|
|
|
++_rtld_objmain->refcount;
|
|
_rtld_objmain->mainref = 1;
|
|
_rtld_objlist_push_tail(&_rtld_list_main, _rtld_objmain);
|
|
|
|
if (ld_preload) {
|
|
/*
|
|
* Pre-load user-specified objects after the main program
|
|
* but before any shared object dependencies.
|
|
*/
|
|
dbg(("preloading objects"));
|
|
if (_rtld_preload(ld_preload) == -1)
|
|
_rtld_die();
|
|
}
|
|
|
|
dbg(("loading needed objects"));
|
|
if (_rtld_load_needed_objects(_rtld_objmain, _RTLD_MAIN) == -1)
|
|
_rtld_die();
|
|
|
|
dbg(("checking for required versions"));
|
|
for (obj = _rtld_objlist; obj != NULL; obj = obj->next) {
|
|
if (_rtld_verify_object_versions(obj) == -1)
|
|
_rtld_die();
|
|
}
|
|
|
|
#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
|
|
dbg(("initializing initial Thread Local Storage offsets"));
|
|
/*
|
|
* All initial objects get the TLS space from the static block.
|
|
*/
|
|
for (obj = _rtld_objlist; obj != NULL; obj = obj->next)
|
|
_rtld_tls_offset_allocate(obj);
|
|
#endif
|
|
|
|
dbg(("relocating objects"));
|
|
if (_rtld_relocate_objects(_rtld_objmain, bind_now) == -1)
|
|
_rtld_die();
|
|
|
|
dbg(("doing copy relocations"));
|
|
if (_rtld_do_copy_relocations(_rtld_objmain) == -1)
|
|
_rtld_die();
|
|
|
|
#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
|
|
dbg(("initializing Thread Local Storage for main thread"));
|
|
/*
|
|
* Set up TLS area for the main thread.
|
|
* This has to be done after all relocations are processed,
|
|
* since .tdata may contain relocations.
|
|
*/
|
|
_rtld_tls_initial_allocation();
|
|
#endif
|
|
|
|
/*
|
|
* Set the __progname, environ and, __mainprog_obj before
|
|
* calling anything that might use them.
|
|
*/
|
|
real___progname = _rtld_objmain_sym("__progname");
|
|
if (real___progname) {
|
|
if (argv[0] != NULL) {
|
|
if ((*real___progname = strrchr(argv[0], '/')) == NULL)
|
|
(*real___progname) = argv[0];
|
|
else
|
|
(*real___progname)++;
|
|
} else {
|
|
(*real___progname) = NULL;
|
|
}
|
|
}
|
|
real_environ = _rtld_objmain_sym("environ");
|
|
if (real_environ)
|
|
*real_environ = environ;
|
|
/*
|
|
* Set __mainprog_obj for old binaries.
|
|
*/
|
|
real___mainprog_obj = _rtld_objmain_sym("__mainprog_obj");
|
|
if (real___mainprog_obj)
|
|
*real___mainprog_obj = _rtld_objmain;
|
|
|
|
_rtld_exclusive_enter(&mask);
|
|
|
|
dbg(("calling _init functions"));
|
|
_rtld_call_init_functions(&mask);
|
|
|
|
dbg(("control at program entry point = %p, obj = %p, exit = %p",
|
|
_rtld_objmain->entry, _rtld_objmain, _rtld_exit));
|
|
|
|
_rtld_exclusive_exit(&mask);
|
|
|
|
/*
|
|
* Return with the entry point and the exit procedure in at the top
|
|
* of stack.
|
|
*/
|
|
|
|
_rtld_debug_state(); /* say hello to gdb! */
|
|
|
|
((void **) osp)[0] = _rtld_exit;
|
|
((void **) osp)[1] = _rtld_objmain;
|
|
return (Elf_Addr) _rtld_objmain->entry;
|
|
}
|
|
|
|
void
|
|
_rtld_die(void)
|
|
{
|
|
const char *msg = dlerror();
|
|
|
|
if (msg == NULL)
|
|
msg = "Fatal error";
|
|
xerrx(1, "%s", msg);
|
|
}
|
|
|
|
static Obj_Entry *
|
|
_rtld_dlcheck(void *handle)
|
|
{
|
|
Obj_Entry *obj;
|
|
|
|
for (obj = _rtld_objlist; obj != NULL; obj = obj->next)
|
|
if (obj == (Obj_Entry *) handle)
|
|
break;
|
|
|
|
if (obj == NULL || obj->dl_refcount == 0) {
|
|
_rtld_error("Invalid shared object handle %p", handle);
|
|
return NULL;
|
|
}
|
|
return obj;
|
|
}
|
|
|
|
static void
|
|
_rtld_initlist_visit(Objlist* list, Obj_Entry *obj, int rev)
|
|
{
|
|
Needed_Entry* elm;
|
|
|
|
/* dbg(("_rtld_initlist_visit(%s)", obj->path)); */
|
|
|
|
if (obj->init_done)
|
|
return;
|
|
obj->init_done = 1;
|
|
|
|
for (elm = obj->needed; elm != NULL; elm = elm->next) {
|
|
if (elm->obj != NULL) {
|
|
_rtld_initlist_visit(list, elm->obj, rev);
|
|
}
|
|
}
|
|
|
|
if (rev) {
|
|
_rtld_objlist_push_head(list, obj);
|
|
} else {
|
|
_rtld_objlist_push_tail(list, obj);
|
|
}
|
|
}
|
|
|
|
static void
|
|
_rtld_initlist_tsort(Objlist* list, int rev)
|
|
{
|
|
dbg(("_rtld_initlist_tsort"));
|
|
|
|
Obj_Entry* obj;
|
|
|
|
for (obj = _rtld_objlist->next; obj; obj = obj->next) {
|
|
obj->init_done = 0;
|
|
}
|
|
|
|
for (obj = _rtld_objlist->next; obj; obj = obj->next) {
|
|
_rtld_initlist_visit(list, obj, rev);
|
|
}
|
|
}
|
|
|
|
static void
|
|
_rtld_init_dag(Obj_Entry *root)
|
|
{
|
|
|
|
_rtld_init_dag1(root, root);
|
|
}
|
|
|
|
static void
|
|
_rtld_init_dag1(Obj_Entry *root, Obj_Entry *obj)
|
|
{
|
|
const Needed_Entry *needed;
|
|
|
|
if (!obj->mainref) {
|
|
if (_rtld_objlist_find(&obj->dldags, root))
|
|
return;
|
|
dbg(("add %p (%s) to %p (%s) DAG", obj, obj->path, root,
|
|
root->path));
|
|
_rtld_objlist_push_tail(&obj->dldags, root);
|
|
_rtld_objlist_push_tail(&root->dagmembers, obj);
|
|
}
|
|
for (needed = obj->needed; needed != NULL; needed = needed->next)
|
|
if (needed->obj != NULL)
|
|
_rtld_init_dag1(root, needed->obj);
|
|
}
|
|
|
|
/*
|
|
* Note, this is called only for objects loaded by dlopen().
|
|
*/
|
|
static void
|
|
_rtld_unload_object(sigset_t *mask, Obj_Entry *root, bool do_fini_funcs)
|
|
{
|
|
|
|
_rtld_unref_dag(root);
|
|
if (root->refcount == 0) { /* We are finished with some objects. */
|
|
Obj_Entry *obj;
|
|
Obj_Entry **linkp;
|
|
Objlist_Entry *elm;
|
|
|
|
/* Finalize objects that are about to be unmapped. */
|
|
if (do_fini_funcs)
|
|
_rtld_call_fini_functions(mask, 0);
|
|
|
|
/* Remove the DAG from all objects' DAG lists. */
|
|
SIMPLEQ_FOREACH(elm, &root->dagmembers, link)
|
|
_rtld_objlist_remove(&elm->obj->dldags, root);
|
|
|
|
/* Remove the DAG from the RTLD_GLOBAL list. */
|
|
if (root->globalref) {
|
|
root->globalref = 0;
|
|
_rtld_objlist_remove(&_rtld_list_global, root);
|
|
}
|
|
|
|
/* Unmap all objects that are no longer referenced. */
|
|
linkp = &_rtld_objlist->next;
|
|
while ((obj = *linkp) != NULL) {
|
|
if (obj->refcount == 0) {
|
|
dbg(("unloading \"%s\"", obj->path));
|
|
if (obj->ehdr != MAP_FAILED)
|
|
munmap(obj->ehdr, _rtld_pagesz);
|
|
munmap(obj->mapbase, obj->mapsize);
|
|
_rtld_objlist_remove(&_rtld_list_global, obj);
|
|
_rtld_linkmap_delete(obj);
|
|
*linkp = obj->next;
|
|
_rtld_objcount--;
|
|
_rtld_obj_free(obj);
|
|
} else
|
|
linkp = &obj->next;
|
|
}
|
|
_rtld_objtail = linkp;
|
|
}
|
|
}
|
|
|
|
void
|
|
_rtld_ref_dag(Obj_Entry *root)
|
|
{
|
|
const Needed_Entry *needed;
|
|
|
|
assert(root);
|
|
|
|
++root->refcount;
|
|
|
|
dbg(("incremented reference on \"%s\" (%d)", root->path,
|
|
root->refcount));
|
|
for (needed = root->needed; needed != NULL;
|
|
needed = needed->next) {
|
|
if (needed->obj != NULL)
|
|
_rtld_ref_dag(needed->obj);
|
|
}
|
|
}
|
|
|
|
static void
|
|
_rtld_unref_dag(Obj_Entry *root)
|
|
{
|
|
|
|
assert(root);
|
|
assert(root->refcount != 0);
|
|
|
|
--root->refcount;
|
|
dbg(("decremented reference on \"%s\" (%d)", root->path,
|
|
root->refcount));
|
|
|
|
if (root->refcount == 0) {
|
|
const Needed_Entry *needed;
|
|
|
|
for (needed = root->needed; needed != NULL;
|
|
needed = needed->next) {
|
|
if (needed->obj != NULL)
|
|
_rtld_unref_dag(needed->obj);
|
|
}
|
|
}
|
|
}
|
|
|
|
__strong_alias(__dlclose,dlclose)
|
|
int
|
|
dlclose(void *handle)
|
|
{
|
|
Obj_Entry *root;
|
|
sigset_t mask;
|
|
|
|
dbg(("dlclose of %p", handle));
|
|
|
|
_rtld_exclusive_enter(&mask);
|
|
|
|
root = _rtld_dlcheck(handle);
|
|
|
|
if (root == NULL) {
|
|
_rtld_exclusive_exit(&mask);
|
|
return -1;
|
|
}
|
|
|
|
_rtld_debug.r_state = RT_DELETE;
|
|
_rtld_debug_state();
|
|
|
|
--root->dl_refcount;
|
|
_rtld_unload_object(&mask, root, true);
|
|
|
|
_rtld_debug.r_state = RT_CONSISTENT;
|
|
_rtld_debug_state();
|
|
|
|
_rtld_exclusive_exit(&mask);
|
|
|
|
return 0;
|
|
}
|
|
|
|
__strong_alias(__dlerror,dlerror)
|
|
char *
|
|
dlerror(void)
|
|
{
|
|
char *msg = error_message;
|
|
|
|
error_message = NULL;
|
|
return msg;
|
|
}
|
|
|
|
__strong_alias(__dlopen,dlopen)
|
|
void *
|
|
dlopen(const char *name, int mode)
|
|
{
|
|
Obj_Entry **old_obj_tail = _rtld_objtail;
|
|
Obj_Entry *obj = NULL;
|
|
int flags = _RTLD_DLOPEN;
|
|
bool nodelete;
|
|
bool now;
|
|
sigset_t mask;
|
|
int result;
|
|
|
|
dbg(("dlopen of %s %d", name, mode));
|
|
|
|
_rtld_exclusive_enter(&mask);
|
|
|
|
flags |= (mode & RTLD_GLOBAL) ? _RTLD_GLOBAL : 0;
|
|
flags |= (mode & RTLD_NOLOAD) ? _RTLD_NOLOAD : 0;
|
|
|
|
nodelete = (mode & RTLD_NODELETE) ? true : false;
|
|
now = ((mode & RTLD_MODEMASK) == RTLD_NOW) ? true : false;
|
|
|
|
_rtld_debug.r_state = RT_ADD;
|
|
_rtld_debug_state();
|
|
|
|
if (name == NULL) {
|
|
obj = _rtld_objmain;
|
|
obj->refcount++;
|
|
} else
|
|
obj = _rtld_load_library(name, _rtld_objmain, flags);
|
|
|
|
|
|
if (obj != NULL) {
|
|
++obj->dl_refcount;
|
|
if (*old_obj_tail != NULL) { /* We loaded something new. */
|
|
assert(*old_obj_tail == obj);
|
|
|
|
result = _rtld_load_needed_objects(obj, flags);
|
|
if (result != -1) {
|
|
Objlist_Entry *entry;
|
|
_rtld_init_dag(obj);
|
|
SIMPLEQ_FOREACH(entry, &obj->dagmembers, link) {
|
|
result = _rtld_verify_object_versions(entry->obj);
|
|
if (result == -1)
|
|
break;
|
|
}
|
|
}
|
|
if (result == -1 || _rtld_relocate_objects(obj,
|
|
(now || obj->z_now)) == -1) {
|
|
_rtld_unload_object(&mask, obj, false);
|
|
obj->dl_refcount--;
|
|
obj = NULL;
|
|
} else {
|
|
_rtld_call_init_functions(&mask);
|
|
}
|
|
}
|
|
if (obj != NULL) {
|
|
if ((nodelete || obj->z_nodelete) && !obj->ref_nodel) {
|
|
dbg(("dlopen obj %s nodelete", obj->path));
|
|
_rtld_ref_dag(obj);
|
|
obj->z_nodelete = obj->ref_nodel = true;
|
|
}
|
|
}
|
|
}
|
|
_rtld_debug.r_state = RT_CONSISTENT;
|
|
_rtld_debug_state();
|
|
|
|
_rtld_exclusive_exit(&mask);
|
|
|
|
return obj;
|
|
}
|
|
|
|
/*
|
|
* Find a symbol in the main program.
|
|
*/
|
|
void *
|
|
_rtld_objmain_sym(const char *name)
|
|
{
|
|
unsigned long hash;
|
|
const Elf_Sym *def;
|
|
const Obj_Entry *obj;
|
|
DoneList donelist;
|
|
|
|
hash = _rtld_elf_hash(name);
|
|
obj = _rtld_objmain;
|
|
_rtld_donelist_init(&donelist);
|
|
|
|
def = _rtld_symlook_list(name, hash, &_rtld_list_main, &obj, 0,
|
|
NULL, &donelist);
|
|
|
|
if (def != NULL)
|
|
return obj->relocbase + def->st_value;
|
|
return NULL;
|
|
}
|
|
|
|
#ifdef __powerpc__
|
|
static void *
|
|
hackish_return_address(void)
|
|
{
|
|
return __builtin_return_address(1);
|
|
}
|
|
#endif
|
|
|
|
#ifdef __HAVE_FUNCTION_DESCRIPTORS
|
|
#define lookup_mutex_enter() _rtld_exclusive_enter(&mask)
|
|
#define lookup_mutex_exit() _rtld_exclusive_exit(&mask)
|
|
#else
|
|
#define lookup_mutex_enter() _rtld_shared_enter()
|
|
#define lookup_mutex_exit() _rtld_shared_exit()
|
|
#endif
|
|
|
|
static void *
|
|
do_dlsym(void *handle, const char *name, const Ver_Entry *ventry, void *retaddr)
|
|
{
|
|
const Obj_Entry *obj;
|
|
unsigned long hash;
|
|
const Elf_Sym *def;
|
|
const Obj_Entry *defobj;
|
|
DoneList donelist;
|
|
const u_int flags = SYMLOOK_DLSYM | SYMLOOK_IN_PLT;
|
|
#ifdef __HAVE_FUNCTION_DESCRIPTORS
|
|
sigset_t mask;
|
|
#endif
|
|
|
|
lookup_mutex_enter();
|
|
|
|
hash = _rtld_elf_hash(name);
|
|
def = NULL;
|
|
defobj = NULL;
|
|
|
|
switch ((intptr_t)handle) {
|
|
case (intptr_t)NULL:
|
|
case (intptr_t)RTLD_NEXT:
|
|
case (intptr_t)RTLD_DEFAULT:
|
|
case (intptr_t)RTLD_SELF:
|
|
if ((obj = _rtld_obj_from_addr(retaddr)) == NULL) {
|
|
_rtld_error("Cannot determine caller's shared object");
|
|
lookup_mutex_exit();
|
|
return NULL;
|
|
}
|
|
|
|
switch ((intptr_t)handle) {
|
|
case (intptr_t)NULL: /* Just the caller's shared object. */
|
|
def = _rtld_symlook_obj(name, hash, obj, flags, ventry);
|
|
defobj = obj;
|
|
break;
|
|
|
|
case (intptr_t)RTLD_NEXT: /* Objects after callers */
|
|
obj = obj->next;
|
|
/*FALLTHROUGH*/
|
|
|
|
case (intptr_t)RTLD_SELF: /* Caller included */
|
|
for (; obj; obj = obj->next) {
|
|
if ((def = _rtld_symlook_obj(name, hash, obj,
|
|
flags, ventry)) != NULL) {
|
|
defobj = obj;
|
|
break;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case (intptr_t)RTLD_DEFAULT:
|
|
def = _rtld_symlook_default(name, hash, obj, &defobj,
|
|
flags, ventry);
|
|
break;
|
|
|
|
default:
|
|
abort();
|
|
}
|
|
break;
|
|
|
|
default:
|
|
if ((obj = _rtld_dlcheck(handle)) == NULL) {
|
|
lookup_mutex_exit();
|
|
return NULL;
|
|
}
|
|
|
|
_rtld_donelist_init(&donelist);
|
|
|
|
if (obj->mainprog) {
|
|
/* Search main program and all libraries loaded by it */
|
|
def = _rtld_symlook_list(name, hash, &_rtld_list_main,
|
|
&defobj, flags, ventry, &donelist);
|
|
} else {
|
|
Needed_Entry fake;
|
|
DoneList depth;
|
|
|
|
/* Search the object and all the libraries loaded by it. */
|
|
fake.next = NULL;
|
|
fake.obj = __UNCONST(obj);
|
|
fake.name = 0;
|
|
|
|
_rtld_donelist_init(&depth);
|
|
def = _rtld_symlook_needed(name, hash, &fake, &defobj,
|
|
flags, ventry, &donelist, &depth);
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
if (def != NULL) {
|
|
void *p;
|
|
#ifdef __HAVE_FUNCTION_DESCRIPTORS
|
|
if (ELF_ST_TYPE(def->st_info) == STT_FUNC) {
|
|
p = (void *)_rtld_function_descriptor_alloc(defobj,
|
|
def, 0);
|
|
lookup_mutex_exit();
|
|
return p;
|
|
}
|
|
#endif /* __HAVE_FUNCTION_DESCRIPTORS */
|
|
p = defobj->relocbase + def->st_value;
|
|
lookup_mutex_exit();
|
|
return p;
|
|
}
|
|
|
|
_rtld_error("Undefined symbol \"%s\"", name);
|
|
lookup_mutex_exit();
|
|
return NULL;
|
|
}
|
|
|
|
__strong_alias(__dlsym,dlsym)
|
|
void *
|
|
dlsym(void *handle, const char *name)
|
|
{
|
|
void *retaddr;
|
|
|
|
dbg(("dlsym of %s in %p", name, handle));
|
|
|
|
#ifdef __powerpc__
|
|
retaddr = hackish_return_address();
|
|
#else
|
|
retaddr = __builtin_return_address(0);
|
|
#endif
|
|
return do_dlsym(handle, name, NULL, retaddr);
|
|
}
|
|
|
|
__strong_alias(__dlvsym,dlvsym)
|
|
void *
|
|
dlvsym(void *handle, const char *name, const char *version)
|
|
{
|
|
Ver_Entry *ventry = NULL;
|
|
Ver_Entry ver_entry;
|
|
void *retaddr;
|
|
|
|
dbg(("dlvsym of %s@%s in %p", name, version ? version : NULL, handle));
|
|
|
|
if (version != NULL) {
|
|
ver_entry.name = version;
|
|
ver_entry.file = NULL;
|
|
ver_entry.hash = _rtld_elf_hash(version);
|
|
ver_entry.flags = 0;
|
|
ventry = &ver_entry;
|
|
}
|
|
#ifdef __powerpc__
|
|
retaddr = hackish_return_address();
|
|
#else
|
|
retaddr = __builtin_return_address(0);
|
|
#endif
|
|
return do_dlsym(handle, name, ventry, retaddr);
|
|
}
|
|
|
|
__strong_alias(__dladdr,dladdr)
|
|
int
|
|
dladdr(const void *addr, Dl_info *info)
|
|
{
|
|
const Obj_Entry *obj;
|
|
const Elf_Sym *def, *best_def;
|
|
void *symbol_addr;
|
|
unsigned long symoffset;
|
|
#ifdef __HAVE_FUNCTION_DESCRIPTORS
|
|
sigset_t mask;
|
|
#endif
|
|
|
|
dbg(("dladdr of %p", addr));
|
|
|
|
lookup_mutex_enter();
|
|
|
|
#ifdef __HAVE_FUNCTION_DESCRIPTORS
|
|
addr = _rtld_function_descriptor_function(addr);
|
|
#endif /* __HAVE_FUNCTION_DESCRIPTORS */
|
|
|
|
obj = _rtld_obj_from_addr(addr);
|
|
if (obj == NULL) {
|
|
_rtld_error("No shared object contains address");
|
|
lookup_mutex_enter();
|
|
return 0;
|
|
}
|
|
info->dli_fname = obj->path;
|
|
info->dli_fbase = obj->mapbase;
|
|
info->dli_saddr = (void *)0;
|
|
info->dli_sname = NULL;
|
|
|
|
/*
|
|
* Walk the symbol list looking for the symbol whose address is
|
|
* closest to the address sent in.
|
|
*/
|
|
best_def = NULL;
|
|
for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
|
|
def = obj->symtab + symoffset;
|
|
|
|
/*
|
|
* For skip the symbol if st_shndx is either SHN_UNDEF or
|
|
* SHN_COMMON.
|
|
*/
|
|
if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
|
|
continue;
|
|
|
|
/*
|
|
* If the symbol is greater than the specified address, or if it
|
|
* is further away from addr than the current nearest symbol,
|
|
* then reject it.
|
|
*/
|
|
symbol_addr = obj->relocbase + def->st_value;
|
|
if (symbol_addr > addr || symbol_addr < info->dli_saddr)
|
|
continue;
|
|
|
|
/* Update our idea of the nearest symbol. */
|
|
info->dli_sname = obj->strtab + def->st_name;
|
|
info->dli_saddr = symbol_addr;
|
|
best_def = def;
|
|
|
|
/* Exact match? */
|
|
if (info->dli_saddr == addr)
|
|
break;
|
|
}
|
|
|
|
#ifdef __HAVE_FUNCTION_DESCRIPTORS
|
|
if (best_def != NULL && ELF_ST_TYPE(best_def->st_info) == STT_FUNC)
|
|
info->dli_saddr = (void *)_rtld_function_descriptor_alloc(obj,
|
|
best_def, 0);
|
|
#endif /* __HAVE_FUNCTION_DESCRIPTORS */
|
|
|
|
lookup_mutex_exit();
|
|
return 1;
|
|
}
|
|
|
|
__strong_alias(__dlinfo,dlinfo)
|
|
int
|
|
dlinfo(void *handle, int req, void *v)
|
|
{
|
|
const Obj_Entry *obj;
|
|
void *retaddr;
|
|
|
|
dbg(("dlinfo for %p %d", handle, req));
|
|
|
|
_rtld_shared_enter();
|
|
|
|
if (handle == RTLD_SELF) {
|
|
#ifdef __powerpc__
|
|
retaddr = hackish_return_address();
|
|
#else
|
|
retaddr = __builtin_return_address(0);
|
|
#endif
|
|
if ((obj = _rtld_obj_from_addr(retaddr)) == NULL) {
|
|
_rtld_error("Cannot determine caller's shared object");
|
|
_rtld_shared_exit();
|
|
return -1;
|
|
}
|
|
} else {
|
|
if ((obj = _rtld_dlcheck(handle)) == NULL) {
|
|
_rtld_shared_exit();
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
switch (req) {
|
|
case RTLD_DI_LINKMAP:
|
|
{
|
|
const struct link_map **map = v;
|
|
|
|
*map = &obj->linkmap;
|
|
break;
|
|
}
|
|
|
|
default:
|
|
_rtld_error("Invalid request");
|
|
_rtld_shared_exit();
|
|
return -1;
|
|
}
|
|
|
|
_rtld_shared_exit();
|
|
return 0;
|
|
}
|
|
|
|
__strong_alias(__dl_iterate_phdr,dl_iterate_phdr);
|
|
int
|
|
dl_iterate_phdr(int (*callback)(struct dl_phdr_info *, size_t, void *), void *param)
|
|
{
|
|
struct dl_phdr_info phdr_info;
|
|
const Obj_Entry *obj;
|
|
int error = 0;
|
|
|
|
dbg(("dl_iterate_phdr"));
|
|
|
|
_rtld_shared_enter();
|
|
|
|
for (obj = _rtld_objlist; obj != NULL; obj = obj->next) {
|
|
phdr_info.dlpi_addr = (Elf_Addr)obj->relocbase;
|
|
phdr_info.dlpi_name = STAILQ_FIRST(&obj->names) ?
|
|
STAILQ_FIRST(&obj->names)->name : obj->path;
|
|
phdr_info.dlpi_phdr = obj->phdr;
|
|
phdr_info.dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
|
|
#if defined(__HAVE_TLS_VARIANT_I) || defined(__HAVE_TLS_VARIANT_II)
|
|
phdr_info.dlpi_tls_modid = obj->tlsindex;
|
|
phdr_info.dlpi_tls_data = obj->tlsinit;
|
|
#else
|
|
phdr_info.dlpi_tls_modid = 0;
|
|
phdr_info.dlpi_tls_data = 0;
|
|
#endif
|
|
phdr_info.dlpi_adds = _rtld_objloads;
|
|
phdr_info.dlpi_subs = _rtld_objloads - _rtld_objcount;
|
|
|
|
/* XXXlocking: exit point */
|
|
error = callback(&phdr_info, sizeof(phdr_info), param);
|
|
if (error)
|
|
break;
|
|
}
|
|
|
|
_rtld_shared_exit();
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* Error reporting function. Use it like printf. If formats the message
|
|
* into a buffer, and sets things up so that the next call to dlerror()
|
|
* will return the message.
|
|
*/
|
|
void
|
|
_rtld_error(const char *fmt,...)
|
|
{
|
|
static char buf[512];
|
|
va_list ap;
|
|
|
|
va_start(ap, fmt);
|
|
xvsnprintf(buf, sizeof buf, fmt, ap);
|
|
error_message = buf;
|
|
va_end(ap);
|
|
}
|
|
|
|
void
|
|
_rtld_debug_state(void)
|
|
{
|
|
|
|
/* Prevent optimizer from removing calls to this function */
|
|
__insn_barrier();
|
|
}
|
|
|
|
void
|
|
_rtld_linkmap_add(Obj_Entry *obj)
|
|
{
|
|
struct link_map *l = &obj->linkmap;
|
|
struct link_map *prev;
|
|
|
|
obj->linkmap.l_name = obj->path;
|
|
obj->linkmap.l_addr = obj->relocbase;
|
|
obj->linkmap.l_ld = obj->dynamic;
|
|
#ifdef __mips__
|
|
/* XXX This field is not standard and will be removed eventually. */
|
|
obj->linkmap.l_offs = obj->relocbase;
|
|
#endif
|
|
|
|
if (_rtld_debug.r_map == NULL) {
|
|
_rtld_debug.r_map = l;
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Scan to the end of the list, but not past the entry for the
|
|
* dynamic linker, which we want to keep at the very end.
|
|
*/
|
|
for (prev = _rtld_debug.r_map;
|
|
prev->l_next != NULL && prev->l_next != &_rtld_objself.linkmap;
|
|
prev = prev->l_next);
|
|
|
|
l->l_prev = prev;
|
|
l->l_next = prev->l_next;
|
|
if (l->l_next != NULL)
|
|
l->l_next->l_prev = l;
|
|
prev->l_next = l;
|
|
}
|
|
|
|
void
|
|
_rtld_linkmap_delete(Obj_Entry *obj)
|
|
{
|
|
struct link_map *l = &obj->linkmap;
|
|
|
|
if (l->l_prev == NULL) {
|
|
if ((_rtld_debug.r_map = l->l_next) != NULL)
|
|
l->l_next->l_prev = NULL;
|
|
return;
|
|
}
|
|
if ((l->l_prev->l_next = l->l_next) != NULL)
|
|
l->l_next->l_prev = l->l_prev;
|
|
}
|
|
|
|
static Obj_Entry *
|
|
_rtld_obj_from_addr(const void *addr)
|
|
{
|
|
Obj_Entry *obj;
|
|
|
|
for (obj = _rtld_objlist; obj != NULL; obj = obj->next) {
|
|
if (addr < (void *) obj->mapbase)
|
|
continue;
|
|
if (addr < (void *) (obj->mapbase + obj->mapsize))
|
|
return obj;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
static void
|
|
_rtld_objlist_clear(Objlist *list)
|
|
{
|
|
while (!SIMPLEQ_EMPTY(list)) {
|
|
Objlist_Entry* elm = SIMPLEQ_FIRST(list);
|
|
SIMPLEQ_REMOVE_HEAD(list, link);
|
|
xfree(elm);
|
|
}
|
|
}
|
|
|
|
static void
|
|
_rtld_objlist_remove(Objlist *list, Obj_Entry *obj)
|
|
{
|
|
Objlist_Entry *elm;
|
|
|
|
if ((elm = _rtld_objlist_find(list, obj)) != NULL) {
|
|
SIMPLEQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
|
|
xfree(elm);
|
|
}
|
|
}
|
|
|
|
#if defined(__minix)
|
|
void _rtld_shared_enter(void) {}
|
|
void _rtld_shared_exit(void) {}
|
|
void _rtld_exclusive_enter(sigset_t *mask) {}
|
|
void _rtld_exclusive_exit(sigset_t *mask) {}
|
|
#else
|
|
#define RTLD_EXCLUSIVE_MASK 0x80000000U
|
|
static volatile unsigned int _rtld_mutex;
|
|
static volatile unsigned int _rtld_waiter_exclusive;
|
|
static volatile unsigned int _rtld_waiter_shared;
|
|
|
|
void
|
|
_rtld_shared_enter(void)
|
|
{
|
|
unsigned int cur;
|
|
lwpid_t waiter, self = 0;
|
|
|
|
membar_enter();
|
|
|
|
for (;;) {
|
|
cur = _rtld_mutex;
|
|
/*
|
|
* First check if we are currently not exclusively locked.
|
|
*/
|
|
if ((cur & RTLD_EXCLUSIVE_MASK) == 0) {
|
|
/* Yes, so increment use counter */
|
|
if (atomic_cas_uint(&_rtld_mutex, cur, cur + 1) != cur)
|
|
continue;
|
|
return;
|
|
}
|
|
/*
|
|
* Someone has an exclusive lock. Puts us on the waiter list.
|
|
*/
|
|
if (!self)
|
|
self = _lwp_self();
|
|
if (cur == (self | RTLD_EXCLUSIVE_MASK)) {
|
|
if (_rtld_mutex_may_recurse)
|
|
return;
|
|
_rtld_error("dead lock detected");
|
|
_rtld_die();
|
|
}
|
|
waiter = atomic_swap_uint(&_rtld_waiter_shared, self);
|
|
/*
|
|
* Check for race against _rtld_exclusive_exit before sleeping.
|
|
*/
|
|
if ((_rtld_mutex & RTLD_EXCLUSIVE_MASK) ||
|
|
_rtld_waiter_exclusive)
|
|
_lwp_park(NULL, -1, __UNVOLATILE(&_rtld_mutex), NULL);
|
|
/* Try to remove us from the waiter list. */
|
|
atomic_cas_uint(&_rtld_waiter_shared, self, 0);
|
|
if (waiter)
|
|
_lwp_unpark(waiter, __UNVOLATILE(&_rtld_mutex));
|
|
}
|
|
}
|
|
|
|
void
|
|
_rtld_shared_exit(void)
|
|
{
|
|
lwpid_t waiter;
|
|
|
|
/*
|
|
* Shared lock taken after an exclusive lock.
|
|
* Just assume this is a partial recursion.
|
|
*/
|
|
if (_rtld_mutex & RTLD_EXCLUSIVE_MASK)
|
|
return;
|
|
|
|
/*
|
|
* Wakeup LWPs waiting for an exclusive lock if this is the last
|
|
* LWP on the shared lock.
|
|
*/
|
|
if (atomic_dec_uint_nv(&_rtld_mutex))
|
|
return;
|
|
if ((waiter = _rtld_waiter_exclusive) != 0)
|
|
_lwp_unpark(waiter, __UNVOLATILE(&_rtld_mutex));
|
|
|
|
membar_exit();
|
|
}
|
|
|
|
void
|
|
_rtld_exclusive_enter(sigset_t *mask)
|
|
{
|
|
lwpid_t waiter, self = _lwp_self();
|
|
unsigned int locked_value = (unsigned int)self | RTLD_EXCLUSIVE_MASK;
|
|
unsigned int cur;
|
|
sigset_t blockmask;
|
|
|
|
sigfillset(&blockmask);
|
|
sigdelset(&blockmask, SIGTRAP); /* Allow the debugger */
|
|
sigprocmask(SIG_BLOCK, &blockmask, mask);
|
|
|
|
membar_enter();
|
|
|
|
for (;;) {
|
|
if (atomic_cas_uint(&_rtld_mutex, 0, locked_value) == 0)
|
|
break;
|
|
waiter = atomic_swap_uint(&_rtld_waiter_exclusive, self);
|
|
cur = _rtld_mutex;
|
|
if (cur == locked_value) {
|
|
_rtld_error("dead lock detected");
|
|
_rtld_die();
|
|
}
|
|
if (cur)
|
|
_lwp_park(NULL, -1, __UNVOLATILE(&_rtld_mutex), NULL);
|
|
atomic_cas_uint(&_rtld_waiter_exclusive, self, 0);
|
|
if (waiter)
|
|
_lwp_unpark(waiter, __UNVOLATILE(&_rtld_mutex));
|
|
}
|
|
}
|
|
|
|
void
|
|
_rtld_exclusive_exit(sigset_t *mask)
|
|
{
|
|
lwpid_t waiter;
|
|
|
|
_rtld_mutex = 0;
|
|
if ((waiter = _rtld_waiter_exclusive) != 0)
|
|
_lwp_unpark(waiter, __UNVOLATILE(&_rtld_mutex));
|
|
|
|
if ((waiter = _rtld_waiter_shared) != 0)
|
|
_lwp_unpark(waiter, __UNVOLATILE(&_rtld_mutex));
|
|
|
|
membar_exit();
|
|
sigprocmask(SIG_SETMASK, mask, NULL);
|
|
}
|
|
#endif /* !defined(__minix) */
|