xref: /freebsd/libexec/rtld-elf/rtld.c (revision c1eb4109f3b1d90a9c1538179ea6a52a191899b2)
1 /*-
2  * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
3  * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>.
4  * Copyright 2009-2012 Konstantin Belousov <kib@FreeBSD.ORG>.
5  * Copyright 2012 John Marino <draco@marino.st>.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 /*
32  * Dynamic linker for ELF.
33  *
34  * John Polstra <jdp@polstra.com>.
35  */
36 
37 #include <sys/param.h>
38 #include <sys/mount.h>
39 #include <sys/mman.h>
40 #include <sys/stat.h>
41 #include <sys/sysctl.h>
42 #include <sys/uio.h>
43 #include <sys/utsname.h>
44 #include <sys/ktrace.h>
45 
46 #include <dlfcn.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <stdarg.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 #include <unistd.h>
55 
56 #include "debug.h"
57 #include "rtld.h"
58 #include "libmap.h"
59 #include "rtld_tls.h"
60 #include "rtld_printf.h"
61 #include "notes.h"
62 
63 #ifndef COMPAT_32BIT
64 #define PATH_RTLD	"/libexec/ld-elf.so.1"
65 #else
66 #define PATH_RTLD	"/libexec/ld-elf32.so.1"
67 #endif
68 
69 /* Types. */
70 typedef void (*func_ptr_type)();
71 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
72 
73 /*
74  * Function declarations.
75  */
76 static const char *basename(const char *);
77 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
78     const Elf_Dyn **, const Elf_Dyn **);
79 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *,
80     const Elf_Dyn *);
81 static void digest_dynamic(Obj_Entry *, int);
82 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
83 static Obj_Entry *dlcheck(void *);
84 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj,
85     int lo_flags, int mode, RtldLockState *lockstate);
86 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
87 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
88 static bool donelist_check(DoneList *, const Obj_Entry *);
89 static void errmsg_restore(char *);
90 static char *errmsg_save(void);
91 static void *fill_search_info(const char *, size_t, void *);
92 static char *find_library(const char *, const Obj_Entry *, int *);
93 static const char *gethints(bool);
94 static void init_dag(Obj_Entry *);
95 static void init_pagesizes(Elf_Auxinfo **aux_info);
96 static void init_rtld(caddr_t, Elf_Auxinfo **);
97 static void initlist_add_neededs(Needed_Entry *, Objlist *);
98 static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
99 static void linkmap_add(Obj_Entry *);
100 static void linkmap_delete(Obj_Entry *);
101 static void load_filtees(Obj_Entry *, int flags, RtldLockState *);
102 static void unload_filtees(Obj_Entry *);
103 static int load_needed_objects(Obj_Entry *, int);
104 static int load_preload_objects(void);
105 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int);
106 static void map_stacks_exec(RtldLockState *);
107 static Obj_Entry *obj_from_addr(const void *);
108 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
109 static void objlist_call_init(Objlist *, RtldLockState *);
110 static void objlist_clear(Objlist *);
111 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
112 static void objlist_init(Objlist *);
113 static void objlist_push_head(Objlist *, Obj_Entry *);
114 static void objlist_push_tail(Objlist *, Obj_Entry *);
115 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *);
116 static void objlist_remove(Objlist *, Obj_Entry *);
117 static int parse_libdir(const char *);
118 static void *path_enumerate(const char *, path_enum_proc, void *);
119 static int relocate_object_dag(Obj_Entry *root, bool bind_now,
120     Obj_Entry *rtldobj, int flags, RtldLockState *lockstate);
121 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
122     int flags, RtldLockState *lockstate);
123 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int,
124     RtldLockState *);
125 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now,
126     int flags, RtldLockState *lockstate);
127 static int rtld_dirname(const char *, char *);
128 static int rtld_dirname_abs(const char *, char *);
129 static void *rtld_dlopen(const char *name, int fd, int mode);
130 static void rtld_exit(void);
131 static char *search_library_path(const char *, const char *);
132 static char *search_library_pathfds(const char *, const char *, int *);
133 static const void **get_program_var_addr(const char *, RtldLockState *);
134 static void set_program_var(const char *, const void *);
135 static int symlook_default(SymLook *, const Obj_Entry *refobj);
136 static int symlook_global(SymLook *, DoneList *);
137 static void symlook_init_from_req(SymLook *, const SymLook *);
138 static int symlook_list(SymLook *, const Objlist *, DoneList *);
139 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *);
140 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *);
141 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *);
142 static void trace_loaded_objects(Obj_Entry *);
143 static void unlink_object(Obj_Entry *);
144 static void unload_object(Obj_Entry *);
145 static void unref_dag(Obj_Entry *);
146 static void ref_dag(Obj_Entry *);
147 static char *origin_subst_one(Obj_Entry *, char *, const char *,
148     const char *, bool);
149 static char *origin_subst(Obj_Entry *, char *);
150 static bool obj_resolve_origin(Obj_Entry *obj);
151 static void preinit_main(void);
152 static int  rtld_verify_versions(const Objlist *);
153 static int  rtld_verify_object_versions(Obj_Entry *);
154 static void object_add_name(Obj_Entry *, const char *);
155 static int  object_match_name(const Obj_Entry *, const char *);
156 static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
157 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
158     struct dl_phdr_info *phdr_info);
159 static uint32_t gnu_hash(const char *);
160 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *,
161     const unsigned long);
162 
163 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported;
164 void _r_debug_postinit(struct link_map *) __noinline __exported;
165 
166 int __sys_openat(int, const char *, int, ...);
167 
168 /*
169  * Data declarations.
170  */
171 static char *error_message;	/* Message for dlerror(), or NULL */
172 struct r_debug r_debug __exported;	/* for GDB; */
173 static bool libmap_disable;	/* Disable libmap */
174 static bool ld_loadfltr;	/* Immediate filters processing */
175 static char *libmap_override;	/* Maps to use in addition to libmap.conf */
176 static bool trust;		/* False for setuid and setgid programs */
177 static bool dangerous_ld_env;	/* True if environment variables have been
178 				   used to affect the libraries loaded */
179 static char *ld_bind_now;	/* Environment variable for immediate binding */
180 static char *ld_debug;		/* Environment variable for debugging */
181 static char *ld_library_path;	/* Environment variable for search path */
182 static char *ld_library_dirs;	/* Environment variable for library descriptors */
183 static char *ld_preload;	/* Environment variable for libraries to
184 				   load first */
185 static char *ld_elf_hints_path;	/* Environment variable for alternative hints path */
186 static char *ld_tracing;	/* Called from ldd to print libs */
187 static char *ld_utrace;		/* Use utrace() to log events. */
188 static Obj_Entry *obj_list;	/* Head of linked list of shared objects */
189 static Obj_Entry **obj_tail;	/* Link field of last object in list */
190 static Obj_Entry *obj_main;	/* The main program shared object */
191 static Obj_Entry obj_rtld;	/* The dynamic linker shared object */
192 static unsigned int obj_count;	/* Number of objects in obj_list */
193 static unsigned int obj_loads;	/* Number of objects in obj_list */
194 
195 static Objlist list_global =	/* Objects dlopened with RTLD_GLOBAL */
196   STAILQ_HEAD_INITIALIZER(list_global);
197 static Objlist list_main =	/* Objects loaded at program startup */
198   STAILQ_HEAD_INITIALIZER(list_main);
199 static Objlist list_fini =	/* Objects needing fini() calls */
200   STAILQ_HEAD_INITIALIZER(list_fini);
201 
202 Elf_Sym sym_zero;		/* For resolving undefined weak refs. */
203 
204 #define GDB_STATE(s,m)	r_debug.r_state = s; r_debug_state(&r_debug,m);
205 
206 extern Elf_Dyn _DYNAMIC;
207 #pragma weak _DYNAMIC
208 #ifndef RTLD_IS_DYNAMIC
209 #define	RTLD_IS_DYNAMIC()	(&_DYNAMIC != NULL)
210 #endif
211 
212 int dlclose(void *) __exported;
213 char *dlerror(void) __exported;
214 void *dlopen(const char *, int) __exported;
215 void *fdlopen(int, int) __exported;
216 void *dlsym(void *, const char *) __exported;
217 dlfunc_t dlfunc(void *, const char *) __exported;
218 void *dlvsym(void *, const char *, const char *) __exported;
219 int dladdr(const void *, Dl_info *) __exported;
220 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *),
221     void (*)(void *), void (*)(void *), void (*)(void *)) __exported;
222 int dlinfo(void *, int , void *) __exported;
223 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported;
224 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported;
225 int _rtld_get_stack_prot(void) __exported;
226 int _rtld_is_dlopened(void *) __exported;
227 void _rtld_error(const char *, ...) __exported;
228 
229 int npagesizes, osreldate;
230 size_t *pagesizes;
231 
232 long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
233 
234 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC;
235 static int max_stack_flags;
236 
237 /*
238  * Global declarations normally provided by crt1.  The dynamic linker is
239  * not built with crt1, so we have to provide them ourselves.
240  */
241 char *__progname;
242 char **environ;
243 
244 /*
245  * Used to pass argc, argv to init functions.
246  */
247 int main_argc;
248 char **main_argv;
249 
250 /*
251  * Globals to control TLS allocation.
252  */
253 size_t tls_last_offset;		/* Static TLS offset of last module */
254 size_t tls_last_size;		/* Static TLS size of last module */
255 size_t tls_static_space;	/* Static TLS space allocated */
256 size_t tls_static_max_align;
257 int tls_dtv_generation = 1;	/* Used to detect when dtv size changes  */
258 int tls_max_index = 1;		/* Largest module index allocated */
259 
260 bool ld_library_path_rpath = false;
261 
262 /*
263  * Fill in a DoneList with an allocation large enough to hold all of
264  * the currently-loaded objects.  Keep this as a macro since it calls
265  * alloca and we want that to occur within the scope of the caller.
266  */
267 #define donelist_init(dlp)					\
268     ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]),	\
269     assert((dlp)->objs != NULL),				\
270     (dlp)->num_alloc = obj_count,				\
271     (dlp)->num_used = 0)
272 
273 #define	UTRACE_DLOPEN_START		1
274 #define	UTRACE_DLOPEN_STOP		2
275 #define	UTRACE_DLCLOSE_START		3
276 #define	UTRACE_DLCLOSE_STOP		4
277 #define	UTRACE_LOAD_OBJECT		5
278 #define	UTRACE_UNLOAD_OBJECT		6
279 #define	UTRACE_ADD_RUNDEP		7
280 #define	UTRACE_PRELOAD_FINISHED		8
281 #define	UTRACE_INIT_CALL		9
282 #define	UTRACE_FINI_CALL		10
283 #define	UTRACE_DLSYM_START		11
284 #define	UTRACE_DLSYM_STOP		12
285 
286 struct utrace_rtld {
287 	char sig[4];			/* 'RTLD' */
288 	int event;
289 	void *handle;
290 	void *mapbase;			/* Used for 'parent' and 'init/fini' */
291 	size_t mapsize;
292 	int refcnt;			/* Used for 'mode' */
293 	char name[MAXPATHLEN];
294 };
295 
296 #define	LD_UTRACE(e, h, mb, ms, r, n) do {			\
297 	if (ld_utrace != NULL)					\
298 		ld_utrace_log(e, h, mb, ms, r, n);		\
299 } while (0)
300 
301 static void
302 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
303     int refcnt, const char *name)
304 {
305 	struct utrace_rtld ut;
306 
307 	ut.sig[0] = 'R';
308 	ut.sig[1] = 'T';
309 	ut.sig[2] = 'L';
310 	ut.sig[3] = 'D';
311 	ut.event = event;
312 	ut.handle = handle;
313 	ut.mapbase = mapbase;
314 	ut.mapsize = mapsize;
315 	ut.refcnt = refcnt;
316 	bzero(ut.name, sizeof(ut.name));
317 	if (name)
318 		strlcpy(ut.name, name, sizeof(ut.name));
319 	utrace(&ut, sizeof(ut));
320 }
321 
322 /*
323  * Main entry point for dynamic linking.  The first argument is the
324  * stack pointer.  The stack is expected to be laid out as described
325  * in the SVR4 ABI specification, Intel 386 Processor Supplement.
326  * Specifically, the stack pointer points to a word containing
327  * ARGC.  Following that in the stack is a null-terminated sequence
328  * of pointers to argument strings.  Then comes a null-terminated
329  * sequence of pointers to environment strings.  Finally, there is a
330  * sequence of "auxiliary vector" entries.
331  *
332  * The second argument points to a place to store the dynamic linker's
333  * exit procedure pointer and the third to a place to store the main
334  * program's object.
335  *
336  * The return value is the main program's entry point.
337  */
338 func_ptr_type
339 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
340 {
341     Elf_Auxinfo *aux_info[AT_COUNT];
342     int i;
343     int argc;
344     char **argv;
345     char **env;
346     Elf_Auxinfo *aux;
347     Elf_Auxinfo *auxp;
348     const char *argv0;
349     Objlist_Entry *entry;
350     Obj_Entry *obj;
351     Obj_Entry **preload_tail;
352     Obj_Entry *last_interposer;
353     Objlist initlist;
354     RtldLockState lockstate;
355     char *library_path_rpath;
356     int mib[2];
357     size_t len;
358 
359     /*
360      * On entry, the dynamic linker itself has not been relocated yet.
361      * Be very careful not to reference any global data until after
362      * init_rtld has returned.  It is OK to reference file-scope statics
363      * and string constants, and to call static and global functions.
364      */
365 
366     /* Find the auxiliary vector on the stack. */
367     argc = *sp++;
368     argv = (char **) sp;
369     sp += argc + 1;	/* Skip over arguments and NULL terminator */
370     env = (char **) sp;
371     while (*sp++ != 0)	/* Skip over environment, and NULL terminator */
372 	;
373     aux = (Elf_Auxinfo *) sp;
374 
375     /* Digest the auxiliary vector. */
376     for (i = 0;  i < AT_COUNT;  i++)
377 	aux_info[i] = NULL;
378     for (auxp = aux;  auxp->a_type != AT_NULL;  auxp++) {
379 	if (auxp->a_type < AT_COUNT)
380 	    aux_info[auxp->a_type] = auxp;
381     }
382 
383     /* Initialize and relocate ourselves. */
384     assert(aux_info[AT_BASE] != NULL);
385     init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
386 
387     __progname = obj_rtld.path;
388     argv0 = argv[0] != NULL ? argv[0] : "(null)";
389     environ = env;
390     main_argc = argc;
391     main_argv = argv;
392 
393     if (aux_info[AT_CANARY] != NULL &&
394 	aux_info[AT_CANARY]->a_un.a_ptr != NULL) {
395 	    i = aux_info[AT_CANARYLEN]->a_un.a_val;
396 	    if (i > sizeof(__stack_chk_guard))
397 		    i = sizeof(__stack_chk_guard);
398 	    memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i);
399     } else {
400 	mib[0] = CTL_KERN;
401 	mib[1] = KERN_ARND;
402 
403 	len = sizeof(__stack_chk_guard);
404 	if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 ||
405 	    len != sizeof(__stack_chk_guard)) {
406 		/* If sysctl was unsuccessful, use the "terminator canary". */
407 		((unsigned char *)(void *)__stack_chk_guard)[0] = 0;
408 		((unsigned char *)(void *)__stack_chk_guard)[1] = 0;
409 		((unsigned char *)(void *)__stack_chk_guard)[2] = '\n';
410 		((unsigned char *)(void *)__stack_chk_guard)[3] = 255;
411 	}
412     }
413 
414     trust = !issetugid();
415 
416     ld_bind_now = getenv(LD_ "BIND_NOW");
417     /*
418      * If the process is tainted, then we un-set the dangerous environment
419      * variables.  The process will be marked as tainted until setuid(2)
420      * is called.  If any child process calls setuid(2) we do not want any
421      * future processes to honor the potentially un-safe variables.
422      */
423     if (!trust) {
424         if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") ||
425 	    unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBRARY_PATH_FDS") ||
426 	    unsetenv(LD_ "LIBMAP_DISABLE") ||
427 	    unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") ||
428 	    unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) {
429 		_rtld_error("environment corrupt; aborting");
430 		rtld_die();
431 	}
432     }
433     ld_debug = getenv(LD_ "DEBUG");
434     libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL;
435     libmap_override = getenv(LD_ "LIBMAP");
436     ld_library_path = getenv(LD_ "LIBRARY_PATH");
437     ld_library_dirs = getenv(LD_ "LIBRARY_PATH_FDS");
438     ld_preload = getenv(LD_ "PRELOAD");
439     ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH");
440     ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL;
441     library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH");
442     if (library_path_rpath != NULL) {
443 	    if (library_path_rpath[0] == 'y' ||
444 		library_path_rpath[0] == 'Y' ||
445 		library_path_rpath[0] == '1')
446 		    ld_library_path_rpath = true;
447 	    else
448 		    ld_library_path_rpath = false;
449     }
450     dangerous_ld_env = libmap_disable || (libmap_override != NULL) ||
451 	(ld_library_path != NULL) || (ld_preload != NULL) ||
452 	(ld_elf_hints_path != NULL) || ld_loadfltr;
453     ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS");
454     ld_utrace = getenv(LD_ "UTRACE");
455 
456     if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
457 	ld_elf_hints_path = _PATH_ELF_HINTS;
458 
459     if (ld_debug != NULL && *ld_debug != '\0')
460 	debug = 1;
461     dbg("%s is initialized, base address = %p", __progname,
462 	(caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
463     dbg("RTLD dynamic = %p", obj_rtld.dynamic);
464     dbg("RTLD pltgot  = %p", obj_rtld.pltgot);
465 
466     dbg("initializing thread locks");
467     lockdflt_init();
468 
469     /*
470      * Load the main program, or process its program header if it is
471      * already loaded.
472      */
473     if (aux_info[AT_EXECFD] != NULL) {	/* Load the main program. */
474 	int fd = aux_info[AT_EXECFD]->a_un.a_val;
475 	dbg("loading main program");
476 	obj_main = map_object(fd, argv0, NULL);
477 	close(fd);
478 	if (obj_main == NULL)
479 	    rtld_die();
480 	max_stack_flags = obj->stack_flags;
481     } else {				/* Main program already loaded. */
482 	const Elf_Phdr *phdr;
483 	int phnum;
484 	caddr_t entry;
485 
486 	dbg("processing main program's program header");
487 	assert(aux_info[AT_PHDR] != NULL);
488 	phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
489 	assert(aux_info[AT_PHNUM] != NULL);
490 	phnum = aux_info[AT_PHNUM]->a_un.a_val;
491 	assert(aux_info[AT_PHENT] != NULL);
492 	assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
493 	assert(aux_info[AT_ENTRY] != NULL);
494 	entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
495 	if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
496 	    rtld_die();
497     }
498 
499     if (aux_info[AT_EXECPATH] != 0) {
500 	    char *kexecpath;
501 	    char buf[MAXPATHLEN];
502 
503 	    kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
504 	    dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
505 	    if (kexecpath[0] == '/')
506 		    obj_main->path = kexecpath;
507 	    else if (getcwd(buf, sizeof(buf)) == NULL ||
508 		     strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
509 		     strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
510 		    obj_main->path = xstrdup(argv0);
511 	    else
512 		    obj_main->path = xstrdup(buf);
513     } else {
514 	    dbg("No AT_EXECPATH");
515 	    obj_main->path = xstrdup(argv0);
516     }
517     dbg("obj_main path %s", obj_main->path);
518     obj_main->mainprog = true;
519 
520     if (aux_info[AT_STACKPROT] != NULL &&
521       aux_info[AT_STACKPROT]->a_un.a_val != 0)
522 	    stack_prot = aux_info[AT_STACKPROT]->a_un.a_val;
523 
524 #ifndef COMPAT_32BIT
525     /*
526      * Get the actual dynamic linker pathname from the executable if
527      * possible.  (It should always be possible.)  That ensures that
528      * gdb will find the right dynamic linker even if a non-standard
529      * one is being used.
530      */
531     if (obj_main->interp != NULL &&
532       strcmp(obj_main->interp, obj_rtld.path) != 0) {
533 	free(obj_rtld.path);
534 	obj_rtld.path = xstrdup(obj_main->interp);
535         __progname = obj_rtld.path;
536     }
537 #endif
538 
539     digest_dynamic(obj_main, 0);
540     dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d",
541 	obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu,
542 	obj_main->dynsymcount);
543 
544     linkmap_add(obj_main);
545     linkmap_add(&obj_rtld);
546 
547     /* Link the main program into the list of objects. */
548     *obj_tail = obj_main;
549     obj_tail = &obj_main->next;
550     obj_count++;
551     obj_loads++;
552 
553     /* Initialize a fake symbol for resolving undefined weak references. */
554     sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
555     sym_zero.st_shndx = SHN_UNDEF;
556     sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
557 
558     if (!libmap_disable)
559         libmap_disable = (bool)lm_init(libmap_override);
560 
561     dbg("loading LD_PRELOAD libraries");
562     if (load_preload_objects() == -1)
563 	rtld_die();
564     preload_tail = obj_tail;
565 
566     dbg("loading needed objects");
567     if (load_needed_objects(obj_main, 0) == -1)
568 	rtld_die();
569 
570     /* Make a list of all objects loaded at startup. */
571     last_interposer = obj_main;
572     for (obj = obj_list;  obj != NULL;  obj = obj->next) {
573 	if (obj->z_interpose && obj != obj_main) {
574 	    objlist_put_after(&list_main, last_interposer, obj);
575 	    last_interposer = obj;
576 	} else {
577 	    objlist_push_tail(&list_main, obj);
578 	}
579     	obj->refcount++;
580     }
581 
582     dbg("checking for required versions");
583     if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
584 	rtld_die();
585 
586     if (ld_tracing) {		/* We're done */
587 	trace_loaded_objects(obj_main);
588 	exit(0);
589     }
590 
591     if (getenv(LD_ "DUMP_REL_PRE") != NULL) {
592        dump_relocations(obj_main);
593        exit (0);
594     }
595 
596     /*
597      * Processing tls relocations requires having the tls offsets
598      * initialized.  Prepare offsets before starting initial
599      * relocation processing.
600      */
601     dbg("initializing initial thread local storage offsets");
602     STAILQ_FOREACH(entry, &list_main, link) {
603 	/*
604 	 * Allocate all the initial objects out of the static TLS
605 	 * block even if they didn't ask for it.
606 	 */
607 	allocate_tls_offset(entry->obj);
608     }
609 
610     if (relocate_objects(obj_main,
611       ld_bind_now != NULL && *ld_bind_now != '\0',
612       &obj_rtld, SYMLOOK_EARLY, NULL) == -1)
613 	rtld_die();
614 
615     dbg("doing copy relocations");
616     if (do_copy_relocations(obj_main) == -1)
617 	rtld_die();
618 
619     if (getenv(LD_ "DUMP_REL_POST") != NULL) {
620        dump_relocations(obj_main);
621        exit (0);
622     }
623 
624     /*
625      * Setup TLS for main thread.  This must be done after the
626      * relocations are processed, since tls initialization section
627      * might be the subject for relocations.
628      */
629     dbg("initializing initial thread local storage");
630     allocate_initial_tls(obj_list);
631 
632     dbg("initializing key program variables");
633     set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
634     set_program_var("environ", env);
635     set_program_var("__elf_aux_vector", aux);
636 
637     /* Make a list of init functions to call. */
638     objlist_init(&initlist);
639     initlist_add_objects(obj_list, preload_tail, &initlist);
640 
641     r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
642 
643     map_stacks_exec(NULL);
644 
645     dbg("resolving ifuncs");
646     if (resolve_objects_ifunc(obj_main,
647       ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY,
648       NULL) == -1)
649 	rtld_die();
650 
651     if (!obj_main->crt_no_init) {
652 	/*
653 	 * Make sure we don't call the main program's init and fini
654 	 * functions for binaries linked with old crt1 which calls
655 	 * _init itself.
656 	 */
657 	obj_main->init = obj_main->fini = (Elf_Addr)NULL;
658 	obj_main->preinit_array = obj_main->init_array =
659 	    obj_main->fini_array = (Elf_Addr)NULL;
660     }
661 
662     wlock_acquire(rtld_bind_lock, &lockstate);
663     if (obj_main->crt_no_init)
664 	preinit_main();
665     objlist_call_init(&initlist, &lockstate);
666     _r_debug_postinit(&obj_main->linkmap);
667     objlist_clear(&initlist);
668     dbg("loading filtees");
669     for (obj = obj_list->next; obj != NULL; obj = obj->next) {
670 	if (ld_loadfltr || obj->z_loadfltr)
671 	    load_filtees(obj, 0, &lockstate);
672     }
673     lock_release(rtld_bind_lock, &lockstate);
674 
675     dbg("transferring control to program entry point = %p", obj_main->entry);
676 
677     /* Return the exit procedure and the program entry point. */
678     *exit_proc = rtld_exit;
679     *objp = obj_main;
680     return (func_ptr_type) obj_main->entry;
681 }
682 
683 void *
684 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def)
685 {
686 	void *ptr;
687 	Elf_Addr target;
688 
689 	ptr = (void *)make_function_pointer(def, obj);
690 	target = ((Elf_Addr (*)(void))ptr)();
691 	return ((void *)target);
692 }
693 
694 Elf_Addr
695 _rtld_bind(Obj_Entry *obj, Elf_Size reloff)
696 {
697     const Elf_Rel *rel;
698     const Elf_Sym *def;
699     const Obj_Entry *defobj;
700     Elf_Addr *where;
701     Elf_Addr target;
702     RtldLockState lockstate;
703 
704     rlock_acquire(rtld_bind_lock, &lockstate);
705     if (sigsetjmp(lockstate.env, 0) != 0)
706 	    lock_upgrade(rtld_bind_lock, &lockstate);
707     if (obj->pltrel)
708 	rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
709     else
710 	rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
711 
712     where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
713     def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL,
714 	&lockstate);
715     if (def == NULL)
716 	rtld_die();
717     if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
718 	target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
719     else
720 	target = (Elf_Addr)(defobj->relocbase + def->st_value);
721 
722     dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
723       defobj->strtab + def->st_name, basename(obj->path),
724       (void *)target, basename(defobj->path));
725 
726     /*
727      * Write the new contents for the jmpslot. Note that depending on
728      * architecture, the value which we need to return back to the
729      * lazy binding trampoline may or may not be the target
730      * address. The value returned from reloc_jmpslot() is the value
731      * that the trampoline needs.
732      */
733     target = reloc_jmpslot(where, target, defobj, obj, rel);
734     lock_release(rtld_bind_lock, &lockstate);
735     return target;
736 }
737 
738 /*
739  * Error reporting function.  Use it like printf.  If formats the message
740  * into a buffer, and sets things up so that the next call to dlerror()
741  * will return the message.
742  */
743 void
744 _rtld_error(const char *fmt, ...)
745 {
746     static char buf[512];
747     va_list ap;
748 
749     va_start(ap, fmt);
750     rtld_vsnprintf(buf, sizeof buf, fmt, ap);
751     error_message = buf;
752     va_end(ap);
753 }
754 
755 /*
756  * Return a dynamically-allocated copy of the current error message, if any.
757  */
758 static char *
759 errmsg_save(void)
760 {
761     return error_message == NULL ? NULL : xstrdup(error_message);
762 }
763 
764 /*
765  * Restore the current error message from a copy which was previously saved
766  * by errmsg_save().  The copy is freed.
767  */
768 static void
769 errmsg_restore(char *saved_msg)
770 {
771     if (saved_msg == NULL)
772 	error_message = NULL;
773     else {
774 	_rtld_error("%s", saved_msg);
775 	free(saved_msg);
776     }
777 }
778 
779 static const char *
780 basename(const char *name)
781 {
782     const char *p = strrchr(name, '/');
783     return p != NULL ? p + 1 : name;
784 }
785 
786 static struct utsname uts;
787 
788 static char *
789 origin_subst_one(Obj_Entry *obj, char *real, const char *kw,
790     const char *subst, bool may_free)
791 {
792 	char *p, *p1, *res, *resp;
793 	int subst_len, kw_len, subst_count, old_len, new_len;
794 
795 	kw_len = strlen(kw);
796 
797 	/*
798 	 * First, count the number of the keyword occurences, to
799 	 * preallocate the final string.
800 	 */
801 	for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) {
802 		p1 = strstr(p, kw);
803 		if (p1 == NULL)
804 			break;
805 	}
806 
807 	/*
808 	 * If the keyword is not found, just return.
809 	 *
810 	 * Return non-substituted string if resolution failed.  We
811 	 * cannot do anything more reasonable, the failure mode of the
812 	 * caller is unresolved library anyway.
813 	 */
814 	if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj)))
815 		return (may_free ? real : xstrdup(real));
816 	if (obj != NULL)
817 		subst = obj->origin_path;
818 
819 	/*
820 	 * There is indeed something to substitute.  Calculate the
821 	 * length of the resulting string, and allocate it.
822 	 */
823 	subst_len = strlen(subst);
824 	old_len = strlen(real);
825 	new_len = old_len + (subst_len - kw_len) * subst_count;
826 	res = xmalloc(new_len + 1);
827 
828 	/*
829 	 * Now, execute the substitution loop.
830 	 */
831 	for (p = real, resp = res, *resp = '\0';;) {
832 		p1 = strstr(p, kw);
833 		if (p1 != NULL) {
834 			/* Copy the prefix before keyword. */
835 			memcpy(resp, p, p1 - p);
836 			resp += p1 - p;
837 			/* Keyword replacement. */
838 			memcpy(resp, subst, subst_len);
839 			resp += subst_len;
840 			*resp = '\0';
841 			p = p1 + kw_len;
842 		} else
843 			break;
844 	}
845 
846 	/* Copy to the end of string and finish. */
847 	strcat(resp, p);
848 	if (may_free)
849 		free(real);
850 	return (res);
851 }
852 
853 static char *
854 origin_subst(Obj_Entry *obj, char *real)
855 {
856 	char *res1, *res2, *res3, *res4;
857 
858 	if (obj == NULL || !trust)
859 		return (xstrdup(real));
860 	if (uts.sysname[0] == '\0') {
861 		if (uname(&uts) != 0) {
862 			_rtld_error("utsname failed: %d", errno);
863 			return (NULL);
864 		}
865 	}
866 	res1 = origin_subst_one(obj, real, "$ORIGIN", NULL, false);
867 	res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true);
868 	res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true);
869 	res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true);
870 	return (res4);
871 }
872 
873 void
874 rtld_die(void)
875 {
876     const char *msg = dlerror();
877 
878     if (msg == NULL)
879 	msg = "Fatal error";
880     rtld_fdputstr(STDERR_FILENO, msg);
881     rtld_fdputchar(STDERR_FILENO, '\n');
882     _exit(1);
883 }
884 
885 /*
886  * Process a shared object's DYNAMIC section, and save the important
887  * information in its Obj_Entry structure.
888  */
889 static void
890 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
891     const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath)
892 {
893     const Elf_Dyn *dynp;
894     Needed_Entry **needed_tail = &obj->needed;
895     Needed_Entry **needed_filtees_tail = &obj->needed_filtees;
896     Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees;
897     const Elf_Hashelt *hashtab;
898     const Elf32_Word *hashval;
899     Elf32_Word bkt, nmaskwords;
900     int bloom_size32;
901     int plttype = DT_REL;
902 
903     *dyn_rpath = NULL;
904     *dyn_soname = NULL;
905     *dyn_runpath = NULL;
906 
907     obj->bind_now = false;
908     for (dynp = obj->dynamic;  dynp->d_tag != DT_NULL;  dynp++) {
909 	switch (dynp->d_tag) {
910 
911 	case DT_REL:
912 	    obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
913 	    break;
914 
915 	case DT_RELSZ:
916 	    obj->relsize = dynp->d_un.d_val;
917 	    break;
918 
919 	case DT_RELENT:
920 	    assert(dynp->d_un.d_val == sizeof(Elf_Rel));
921 	    break;
922 
923 	case DT_JMPREL:
924 	    obj->pltrel = (const Elf_Rel *)
925 	      (obj->relocbase + dynp->d_un.d_ptr);
926 	    break;
927 
928 	case DT_PLTRELSZ:
929 	    obj->pltrelsize = dynp->d_un.d_val;
930 	    break;
931 
932 	case DT_RELA:
933 	    obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
934 	    break;
935 
936 	case DT_RELASZ:
937 	    obj->relasize = dynp->d_un.d_val;
938 	    break;
939 
940 	case DT_RELAENT:
941 	    assert(dynp->d_un.d_val == sizeof(Elf_Rela));
942 	    break;
943 
944 	case DT_PLTREL:
945 	    plttype = dynp->d_un.d_val;
946 	    assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
947 	    break;
948 
949 	case DT_SYMTAB:
950 	    obj->symtab = (const Elf_Sym *)
951 	      (obj->relocbase + dynp->d_un.d_ptr);
952 	    break;
953 
954 	case DT_SYMENT:
955 	    assert(dynp->d_un.d_val == sizeof(Elf_Sym));
956 	    break;
957 
958 	case DT_STRTAB:
959 	    obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
960 	    break;
961 
962 	case DT_STRSZ:
963 	    obj->strsize = dynp->d_un.d_val;
964 	    break;
965 
966 	case DT_VERNEED:
967 	    obj->verneed = (const Elf_Verneed *) (obj->relocbase +
968 		dynp->d_un.d_val);
969 	    break;
970 
971 	case DT_VERNEEDNUM:
972 	    obj->verneednum = dynp->d_un.d_val;
973 	    break;
974 
975 	case DT_VERDEF:
976 	    obj->verdef = (const Elf_Verdef *) (obj->relocbase +
977 		dynp->d_un.d_val);
978 	    break;
979 
980 	case DT_VERDEFNUM:
981 	    obj->verdefnum = dynp->d_un.d_val;
982 	    break;
983 
984 	case DT_VERSYM:
985 	    obj->versyms = (const Elf_Versym *)(obj->relocbase +
986 		dynp->d_un.d_val);
987 	    break;
988 
989 	case DT_HASH:
990 	    {
991 		hashtab = (const Elf_Hashelt *)(obj->relocbase +
992 		    dynp->d_un.d_ptr);
993 		obj->nbuckets = hashtab[0];
994 		obj->nchains = hashtab[1];
995 		obj->buckets = hashtab + 2;
996 		obj->chains = obj->buckets + obj->nbuckets;
997 		obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 &&
998 		  obj->buckets != NULL;
999 	    }
1000 	    break;
1001 
1002 	case DT_GNU_HASH:
1003 	    {
1004 		hashtab = (const Elf_Hashelt *)(obj->relocbase +
1005 		    dynp->d_un.d_ptr);
1006 		obj->nbuckets_gnu = hashtab[0];
1007 		obj->symndx_gnu = hashtab[1];
1008 		nmaskwords = hashtab[2];
1009 		bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords;
1010 		obj->maskwords_bm_gnu = nmaskwords - 1;
1011 		obj->shift2_gnu = hashtab[3];
1012 		obj->bloom_gnu = (Elf_Addr *) (hashtab + 4);
1013 		obj->buckets_gnu = hashtab + 4 + bloom_size32;
1014 		obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu -
1015 		  obj->symndx_gnu;
1016 		/* Number of bitmask words is required to be power of 2 */
1017 		obj->valid_hash_gnu = powerof2(nmaskwords) &&
1018 		    obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL;
1019 	    }
1020 	    break;
1021 
1022 	case DT_NEEDED:
1023 	    if (!obj->rtld) {
1024 		Needed_Entry *nep = NEW(Needed_Entry);
1025 		nep->name = dynp->d_un.d_val;
1026 		nep->obj = NULL;
1027 		nep->next = NULL;
1028 
1029 		*needed_tail = nep;
1030 		needed_tail = &nep->next;
1031 	    }
1032 	    break;
1033 
1034 	case DT_FILTER:
1035 	    if (!obj->rtld) {
1036 		Needed_Entry *nep = NEW(Needed_Entry);
1037 		nep->name = dynp->d_un.d_val;
1038 		nep->obj = NULL;
1039 		nep->next = NULL;
1040 
1041 		*needed_filtees_tail = nep;
1042 		needed_filtees_tail = &nep->next;
1043 	    }
1044 	    break;
1045 
1046 	case DT_AUXILIARY:
1047 	    if (!obj->rtld) {
1048 		Needed_Entry *nep = NEW(Needed_Entry);
1049 		nep->name = dynp->d_un.d_val;
1050 		nep->obj = NULL;
1051 		nep->next = NULL;
1052 
1053 		*needed_aux_filtees_tail = nep;
1054 		needed_aux_filtees_tail = &nep->next;
1055 	    }
1056 	    break;
1057 
1058 	case DT_PLTGOT:
1059 	    obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
1060 	    break;
1061 
1062 	case DT_TEXTREL:
1063 	    obj->textrel = true;
1064 	    break;
1065 
1066 	case DT_SYMBOLIC:
1067 	    obj->symbolic = true;
1068 	    break;
1069 
1070 	case DT_RPATH:
1071 	    /*
1072 	     * We have to wait until later to process this, because we
1073 	     * might not have gotten the address of the string table yet.
1074 	     */
1075 	    *dyn_rpath = dynp;
1076 	    break;
1077 
1078 	case DT_SONAME:
1079 	    *dyn_soname = dynp;
1080 	    break;
1081 
1082 	case DT_RUNPATH:
1083 	    *dyn_runpath = dynp;
1084 	    break;
1085 
1086 	case DT_INIT:
1087 	    obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1088 	    break;
1089 
1090 	case DT_PREINIT_ARRAY:
1091 	    obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1092 	    break;
1093 
1094 	case DT_PREINIT_ARRAYSZ:
1095 	    obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1096 	    break;
1097 
1098 	case DT_INIT_ARRAY:
1099 	    obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1100 	    break;
1101 
1102 	case DT_INIT_ARRAYSZ:
1103 	    obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1104 	    break;
1105 
1106 	case DT_FINI:
1107 	    obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1108 	    break;
1109 
1110 	case DT_FINI_ARRAY:
1111 	    obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1112 	    break;
1113 
1114 	case DT_FINI_ARRAYSZ:
1115 	    obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1116 	    break;
1117 
1118 	/*
1119 	 * Don't process DT_DEBUG on MIPS as the dynamic section
1120 	 * is mapped read-only. DT_MIPS_RLD_MAP is used instead.
1121 	 */
1122 
1123 #ifndef __mips__
1124 	case DT_DEBUG:
1125 	    /* XXX - not implemented yet */
1126 	    if (!early)
1127 		dbg("Filling in DT_DEBUG entry");
1128 	    ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
1129 	    break;
1130 #endif
1131 
1132 	case DT_FLAGS:
1133 		if (dynp->d_un.d_val & DF_ORIGIN)
1134 		    obj->z_origin = true;
1135 		if (dynp->d_un.d_val & DF_SYMBOLIC)
1136 		    obj->symbolic = true;
1137 		if (dynp->d_un.d_val & DF_TEXTREL)
1138 		    obj->textrel = true;
1139 		if (dynp->d_un.d_val & DF_BIND_NOW)
1140 		    obj->bind_now = true;
1141 		/*if (dynp->d_un.d_val & DF_STATIC_TLS)
1142 		    ;*/
1143 	    break;
1144 #ifdef __mips__
1145 	case DT_MIPS_LOCAL_GOTNO:
1146 		obj->local_gotno = dynp->d_un.d_val;
1147 	    break;
1148 
1149 	case DT_MIPS_SYMTABNO:
1150 		obj->symtabno = dynp->d_un.d_val;
1151 		break;
1152 
1153 	case DT_MIPS_GOTSYM:
1154 		obj->gotsym = dynp->d_un.d_val;
1155 		break;
1156 
1157 	case DT_MIPS_RLD_MAP:
1158 		*((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug;
1159 		break;
1160 #endif
1161 
1162 	case DT_FLAGS_1:
1163 		if (dynp->d_un.d_val & DF_1_NOOPEN)
1164 		    obj->z_noopen = true;
1165 		if (dynp->d_un.d_val & DF_1_ORIGIN)
1166 		    obj->z_origin = true;
1167 		if (dynp->d_un.d_val & DF_1_GLOBAL)
1168 		    obj->z_global = true;
1169 		if (dynp->d_un.d_val & DF_1_BIND_NOW)
1170 		    obj->bind_now = true;
1171 		if (dynp->d_un.d_val & DF_1_NODELETE)
1172 		    obj->z_nodelete = true;
1173 		if (dynp->d_un.d_val & DF_1_LOADFLTR)
1174 		    obj->z_loadfltr = true;
1175 		if (dynp->d_un.d_val & DF_1_INTERPOSE)
1176 		    obj->z_interpose = true;
1177 		if (dynp->d_un.d_val & DF_1_NODEFLIB)
1178 		    obj->z_nodeflib = true;
1179 	    break;
1180 
1181 	default:
1182 	    if (!early) {
1183 		dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
1184 		    (long)dynp->d_tag);
1185 	    }
1186 	    break;
1187 	}
1188     }
1189 
1190     obj->traced = false;
1191 
1192     if (plttype == DT_RELA) {
1193 	obj->pltrela = (const Elf_Rela *) obj->pltrel;
1194 	obj->pltrel = NULL;
1195 	obj->pltrelasize = obj->pltrelsize;
1196 	obj->pltrelsize = 0;
1197     }
1198 
1199     /* Determine size of dynsym table (equal to nchains of sysv hash) */
1200     if (obj->valid_hash_sysv)
1201 	obj->dynsymcount = obj->nchains;
1202     else if (obj->valid_hash_gnu) {
1203 	obj->dynsymcount = 0;
1204 	for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) {
1205 	    if (obj->buckets_gnu[bkt] == 0)
1206 		continue;
1207 	    hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]];
1208 	    do
1209 		obj->dynsymcount++;
1210 	    while ((*hashval++ & 1u) == 0);
1211 	}
1212 	obj->dynsymcount += obj->symndx_gnu;
1213     }
1214 }
1215 
1216 static bool
1217 obj_resolve_origin(Obj_Entry *obj)
1218 {
1219 
1220 	if (obj->origin_path != NULL)
1221 		return (true);
1222 	obj->origin_path = xmalloc(PATH_MAX);
1223 	return (rtld_dirname_abs(obj->path, obj->origin_path) != -1);
1224 }
1225 
1226 static void
1227 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
1228     const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath)
1229 {
1230 
1231 	if (obj->z_origin && !obj_resolve_origin(obj))
1232 		rtld_die();
1233 
1234 	if (dyn_runpath != NULL) {
1235 		obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val;
1236 		obj->runpath = origin_subst(obj, obj->runpath);
1237 	} else if (dyn_rpath != NULL) {
1238 		obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
1239 		obj->rpath = origin_subst(obj, obj->rpath);
1240 	}
1241 	if (dyn_soname != NULL)
1242 		object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
1243 }
1244 
1245 static void
1246 digest_dynamic(Obj_Entry *obj, int early)
1247 {
1248 	const Elf_Dyn *dyn_rpath;
1249 	const Elf_Dyn *dyn_soname;
1250 	const Elf_Dyn *dyn_runpath;
1251 
1252 	digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath);
1253 	digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath);
1254 }
1255 
1256 /*
1257  * Process a shared object's program header.  This is used only for the
1258  * main program, when the kernel has already loaded the main program
1259  * into memory before calling the dynamic linker.  It creates and
1260  * returns an Obj_Entry structure.
1261  */
1262 static Obj_Entry *
1263 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
1264 {
1265     Obj_Entry *obj;
1266     const Elf_Phdr *phlimit = phdr + phnum;
1267     const Elf_Phdr *ph;
1268     Elf_Addr note_start, note_end;
1269     int nsegs = 0;
1270 
1271     obj = obj_new();
1272     for (ph = phdr;  ph < phlimit;  ph++) {
1273 	if (ph->p_type != PT_PHDR)
1274 	    continue;
1275 
1276 	obj->phdr = phdr;
1277 	obj->phsize = ph->p_memsz;
1278 	obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
1279 	break;
1280     }
1281 
1282     obj->stack_flags = PF_X | PF_R | PF_W;
1283 
1284     for (ph = phdr;  ph < phlimit;  ph++) {
1285 	switch (ph->p_type) {
1286 
1287 	case PT_INTERP:
1288 	    obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
1289 	    break;
1290 
1291 	case PT_LOAD:
1292 	    if (nsegs == 0) {	/* First load segment */
1293 		obj->vaddrbase = trunc_page(ph->p_vaddr);
1294 		obj->mapbase = obj->vaddrbase + obj->relocbase;
1295 		obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
1296 		  obj->vaddrbase;
1297 	    } else {		/* Last load segment */
1298 		obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1299 		  obj->vaddrbase;
1300 	    }
1301 	    nsegs++;
1302 	    break;
1303 
1304 	case PT_DYNAMIC:
1305 	    obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
1306 	    break;
1307 
1308 	case PT_TLS:
1309 	    obj->tlsindex = 1;
1310 	    obj->tlssize = ph->p_memsz;
1311 	    obj->tlsalign = ph->p_align;
1312 	    obj->tlsinitsize = ph->p_filesz;
1313 	    obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
1314 	    break;
1315 
1316 	case PT_GNU_STACK:
1317 	    obj->stack_flags = ph->p_flags;
1318 	    break;
1319 
1320 	case PT_GNU_RELRO:
1321 	    obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
1322 	    obj->relro_size = round_page(ph->p_memsz);
1323 	    break;
1324 
1325 	case PT_NOTE:
1326 	    note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr;
1327 	    note_end = note_start + ph->p_filesz;
1328 	    digest_notes(obj, note_start, note_end);
1329 	    break;
1330 	}
1331     }
1332     if (nsegs < 1) {
1333 	_rtld_error("%s: too few PT_LOAD segments", path);
1334 	return NULL;
1335     }
1336 
1337     obj->entry = entry;
1338     return obj;
1339 }
1340 
1341 void
1342 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end)
1343 {
1344 	const Elf_Note *note;
1345 	const char *note_name;
1346 	uintptr_t p;
1347 
1348 	for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end;
1349 	    note = (const Elf_Note *)((const char *)(note + 1) +
1350 	      roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
1351 	      roundup2(note->n_descsz, sizeof(Elf32_Addr)))) {
1352 		if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) ||
1353 		    note->n_descsz != sizeof(int32_t))
1354 			continue;
1355 		if (note->n_type != ABI_NOTETYPE &&
1356 		    note->n_type != CRT_NOINIT_NOTETYPE)
1357 			continue;
1358 		note_name = (const char *)(note + 1);
1359 		if (strncmp(NOTE_FREEBSD_VENDOR, note_name,
1360 		    sizeof(NOTE_FREEBSD_VENDOR)) != 0)
1361 			continue;
1362 		switch (note->n_type) {
1363 		case ABI_NOTETYPE:
1364 			/* FreeBSD osrel note */
1365 			p = (uintptr_t)(note + 1);
1366 			p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1367 			obj->osrel = *(const int32_t *)(p);
1368 			dbg("note osrel %d", obj->osrel);
1369 			break;
1370 		case CRT_NOINIT_NOTETYPE:
1371 			/* FreeBSD 'crt does not call init' note */
1372 			obj->crt_no_init = true;
1373 			dbg("note crt_no_init");
1374 			break;
1375 		}
1376 	}
1377 }
1378 
1379 static Obj_Entry *
1380 dlcheck(void *handle)
1381 {
1382     Obj_Entry *obj;
1383 
1384     for (obj = obj_list;  obj != NULL;  obj = obj->next)
1385 	if (obj == (Obj_Entry *) handle)
1386 	    break;
1387 
1388     if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1389 	_rtld_error("Invalid shared object handle %p", handle);
1390 	return NULL;
1391     }
1392     return obj;
1393 }
1394 
1395 /*
1396  * If the given object is already in the donelist, return true.  Otherwise
1397  * add the object to the list and return false.
1398  */
1399 static bool
1400 donelist_check(DoneList *dlp, const Obj_Entry *obj)
1401 {
1402     unsigned int i;
1403 
1404     for (i = 0;  i < dlp->num_used;  i++)
1405 	if (dlp->objs[i] == obj)
1406 	    return true;
1407     /*
1408      * Our donelist allocation should always be sufficient.  But if
1409      * our threads locking isn't working properly, more shared objects
1410      * could have been loaded since we allocated the list.  That should
1411      * never happen, but we'll handle it properly just in case it does.
1412      */
1413     if (dlp->num_used < dlp->num_alloc)
1414 	dlp->objs[dlp->num_used++] = obj;
1415     return false;
1416 }
1417 
1418 /*
1419  * Hash function for symbol table lookup.  Don't even think about changing
1420  * this.  It is specified by the System V ABI.
1421  */
1422 unsigned long
1423 elf_hash(const char *name)
1424 {
1425     const unsigned char *p = (const unsigned char *) name;
1426     unsigned long h = 0;
1427     unsigned long g;
1428 
1429     while (*p != '\0') {
1430 	h = (h << 4) + *p++;
1431 	if ((g = h & 0xf0000000) != 0)
1432 	    h ^= g >> 24;
1433 	h &= ~g;
1434     }
1435     return h;
1436 }
1437 
1438 /*
1439  * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits
1440  * unsigned in case it's implemented with a wider type.
1441  */
1442 static uint32_t
1443 gnu_hash(const char *s)
1444 {
1445 	uint32_t h;
1446 	unsigned char c;
1447 
1448 	h = 5381;
1449 	for (c = *s; c != '\0'; c = *++s)
1450 		h = h * 33 + c;
1451 	return (h & 0xffffffff);
1452 }
1453 
1454 
1455 /*
1456  * Find the library with the given name, and return its full pathname.
1457  * The returned string is dynamically allocated.  Generates an error
1458  * message and returns NULL if the library cannot be found.
1459  *
1460  * If the second argument is non-NULL, then it refers to an already-
1461  * loaded shared object, whose library search path will be searched.
1462  *
1463  * If a library is successfully located via LD_LIBRARY_PATH_FDS, its
1464  * descriptor (which is close-on-exec) will be passed out via the third
1465  * argument.
1466  *
1467  * The search order is:
1468  *   DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1)
1469  *   DT_RPATH of the main object if DSO without defined DT_RUNPATH (1)
1470  *   LD_LIBRARY_PATH
1471  *   DT_RUNPATH in the referencing file
1472  *   ldconfig hints (if -z nodefaultlib, filter out default library directories
1473  *	 from list)
1474  *   /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib
1475  *
1476  * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined.
1477  */
1478 static char *
1479 find_library(const char *xname, const Obj_Entry *refobj, int *fdp)
1480 {
1481     char *pathname;
1482     char *name;
1483     bool nodeflib, objgiven;
1484 
1485     objgiven = refobj != NULL;
1486     if (strchr(xname, '/') != NULL) {	/* Hard coded pathname */
1487 	if (xname[0] != '/' && !trust) {
1488 	    _rtld_error("Absolute pathname required for shared object \"%s\"",
1489 	      xname);
1490 	    return NULL;
1491 	}
1492 	return (origin_subst(__DECONST(Obj_Entry *, refobj),
1493 	  __DECONST(char *, xname)));
1494     }
1495 
1496     if (libmap_disable || !objgiven ||
1497 	(name = lm_find(refobj->path, xname)) == NULL)
1498 	name = (char *)xname;
1499 
1500     dbg(" Searching for \"%s\"", name);
1501 
1502     /*
1503      * If refobj->rpath != NULL, then refobj->runpath is NULL.  Fall
1504      * back to pre-conforming behaviour if user requested so with
1505      * LD_LIBRARY_PATH_RPATH environment variable and ignore -z
1506      * nodeflib.
1507      */
1508     if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) {
1509 	if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
1510 	  (refobj != NULL &&
1511 	  (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1512 	  (pathname = search_library_pathfds(name, ld_library_dirs, fdp)) != NULL ||
1513           (pathname = search_library_path(name, gethints(false))) != NULL ||
1514 	  (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
1515 	    return (pathname);
1516     } else {
1517 	nodeflib = objgiven ? refobj->z_nodeflib : false;
1518 	if ((objgiven &&
1519 	  (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1520 	  (objgiven && refobj->runpath == NULL && refobj != obj_main &&
1521 	  (pathname = search_library_path(name, obj_main->rpath)) != NULL) ||
1522 	  (pathname = search_library_path(name, ld_library_path)) != NULL ||
1523 	  (objgiven &&
1524 	  (pathname = search_library_path(name, refobj->runpath)) != NULL) ||
1525 	  (pathname = search_library_pathfds(name, ld_library_dirs, fdp)) != NULL ||
1526 	  (pathname = search_library_path(name, gethints(nodeflib))) != NULL ||
1527 	  (objgiven && !nodeflib &&
1528 	  (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL))
1529 	    return (pathname);
1530     }
1531 
1532     if (objgiven && refobj->path != NULL) {
1533 	_rtld_error("Shared object \"%s\" not found, required by \"%s\"",
1534 	  name, basename(refobj->path));
1535     } else {
1536 	_rtld_error("Shared object \"%s\" not found", name);
1537     }
1538     return NULL;
1539 }
1540 
1541 /*
1542  * Given a symbol number in a referencing object, find the corresponding
1543  * definition of the symbol.  Returns a pointer to the symbol, or NULL if
1544  * no definition was found.  Returns a pointer to the Obj_Entry of the
1545  * defining object via the reference parameter DEFOBJ_OUT.
1546  */
1547 const Elf_Sym *
1548 find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1549     const Obj_Entry **defobj_out, int flags, SymCache *cache,
1550     RtldLockState *lockstate)
1551 {
1552     const Elf_Sym *ref;
1553     const Elf_Sym *def;
1554     const Obj_Entry *defobj;
1555     SymLook req;
1556     const char *name;
1557     int res;
1558 
1559     /*
1560      * If we have already found this symbol, get the information from
1561      * the cache.
1562      */
1563     if (symnum >= refobj->dynsymcount)
1564 	return NULL;	/* Bad object */
1565     if (cache != NULL && cache[symnum].sym != NULL) {
1566 	*defobj_out = cache[symnum].obj;
1567 	return cache[symnum].sym;
1568     }
1569 
1570     ref = refobj->symtab + symnum;
1571     name = refobj->strtab + ref->st_name;
1572     def = NULL;
1573     defobj = NULL;
1574 
1575     /*
1576      * We don't have to do a full scale lookup if the symbol is local.
1577      * We know it will bind to the instance in this load module; to
1578      * which we already have a pointer (ie ref). By not doing a lookup,
1579      * we not only improve performance, but it also avoids unresolvable
1580      * symbols when local symbols are not in the hash table. This has
1581      * been seen with the ia64 toolchain.
1582      */
1583     if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1584 	if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
1585 	    _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1586 		symnum);
1587 	}
1588 	symlook_init(&req, name);
1589 	req.flags = flags;
1590 	req.ventry = fetch_ventry(refobj, symnum);
1591 	req.lockstate = lockstate;
1592 	res = symlook_default(&req, refobj);
1593 	if (res == 0) {
1594 	    def = req.sym_out;
1595 	    defobj = req.defobj_out;
1596 	}
1597     } else {
1598 	def = ref;
1599 	defobj = refobj;
1600     }
1601 
1602     /*
1603      * If we found no definition and the reference is weak, treat the
1604      * symbol as having the value zero.
1605      */
1606     if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1607 	def = &sym_zero;
1608 	defobj = obj_main;
1609     }
1610 
1611     if (def != NULL) {
1612 	*defobj_out = defobj;
1613 	/* Record the information in the cache to avoid subsequent lookups. */
1614 	if (cache != NULL) {
1615 	    cache[symnum].sym = def;
1616 	    cache[symnum].obj = defobj;
1617 	}
1618     } else {
1619 	if (refobj != &obj_rtld)
1620 	    _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1621     }
1622     return def;
1623 }
1624 
1625 /*
1626  * Return the search path from the ldconfig hints file, reading it if
1627  * necessary.  If nostdlib is true, then the default search paths are
1628  * not added to result.
1629  *
1630  * Returns NULL if there are problems with the hints file,
1631  * or if the search path there is empty.
1632  */
1633 static const char *
1634 gethints(bool nostdlib)
1635 {
1636 	static char *hints, *filtered_path;
1637 	struct elfhints_hdr hdr;
1638 	struct fill_search_info_args sargs, hargs;
1639 	struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo;
1640 	struct dl_serpath *SLPpath, *hintpath;
1641 	char *p;
1642 	unsigned int SLPndx, hintndx, fndx, fcount;
1643 	int fd;
1644 	size_t flen;
1645 	bool skip;
1646 
1647 	/* First call, read the hints file */
1648 	if (hints == NULL) {
1649 		/* Keep from trying again in case the hints file is bad. */
1650 		hints = "";
1651 
1652 		if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1)
1653 			return (NULL);
1654 		if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1655 		    hdr.magic != ELFHINTS_MAGIC ||
1656 		    hdr.version != 1) {
1657 			close(fd);
1658 			return (NULL);
1659 		}
1660 		p = xmalloc(hdr.dirlistlen + 1);
1661 		if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1662 		    read(fd, p, hdr.dirlistlen + 1) !=
1663 		    (ssize_t)hdr.dirlistlen + 1) {
1664 			free(p);
1665 			close(fd);
1666 			return (NULL);
1667 		}
1668 		hints = p;
1669 		close(fd);
1670 	}
1671 
1672 	/*
1673 	 * If caller agreed to receive list which includes the default
1674 	 * paths, we are done. Otherwise, if we still did not
1675 	 * calculated filtered result, do it now.
1676 	 */
1677 	if (!nostdlib)
1678 		return (hints[0] != '\0' ? hints : NULL);
1679 	if (filtered_path != NULL)
1680 		goto filt_ret;
1681 
1682 	/*
1683 	 * Obtain the list of all configured search paths, and the
1684 	 * list of the default paths.
1685 	 *
1686 	 * First estimate the size of the results.
1687 	 */
1688 	smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
1689 	smeta.dls_cnt = 0;
1690 	hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
1691 	hmeta.dls_cnt = 0;
1692 
1693 	sargs.request = RTLD_DI_SERINFOSIZE;
1694 	sargs.serinfo = &smeta;
1695 	hargs.request = RTLD_DI_SERINFOSIZE;
1696 	hargs.serinfo = &hmeta;
1697 
1698 	path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs);
1699 	path_enumerate(p, fill_search_info, &hargs);
1700 
1701 	SLPinfo = xmalloc(smeta.dls_size);
1702 	hintinfo = xmalloc(hmeta.dls_size);
1703 
1704 	/*
1705 	 * Next fetch both sets of paths.
1706 	 */
1707 	sargs.request = RTLD_DI_SERINFO;
1708 	sargs.serinfo = SLPinfo;
1709 	sargs.serpath = &SLPinfo->dls_serpath[0];
1710 	sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt];
1711 
1712 	hargs.request = RTLD_DI_SERINFO;
1713 	hargs.serinfo = hintinfo;
1714 	hargs.serpath = &hintinfo->dls_serpath[0];
1715 	hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt];
1716 
1717 	path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs);
1718 	path_enumerate(p, fill_search_info, &hargs);
1719 
1720 	/*
1721 	 * Now calculate the difference between two sets, by excluding
1722 	 * standard paths from the full set.
1723 	 */
1724 	fndx = 0;
1725 	fcount = 0;
1726 	filtered_path = xmalloc(hdr.dirlistlen + 1);
1727 	hintpath = &hintinfo->dls_serpath[0];
1728 	for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) {
1729 		skip = false;
1730 		SLPpath = &SLPinfo->dls_serpath[0];
1731 		/*
1732 		 * Check each standard path against current.
1733 		 */
1734 		for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) {
1735 			/* matched, skip the path */
1736 			if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) {
1737 				skip = true;
1738 				break;
1739 			}
1740 		}
1741 		if (skip)
1742 			continue;
1743 		/*
1744 		 * Not matched against any standard path, add the path
1745 		 * to result. Separate consequtive paths with ':'.
1746 		 */
1747 		if (fcount > 0) {
1748 			filtered_path[fndx] = ':';
1749 			fndx++;
1750 		}
1751 		fcount++;
1752 		flen = strlen(hintpath->dls_name);
1753 		strncpy((filtered_path + fndx),	hintpath->dls_name, flen);
1754 		fndx += flen;
1755 	}
1756 	filtered_path[fndx] = '\0';
1757 
1758 	free(SLPinfo);
1759 	free(hintinfo);
1760 
1761 filt_ret:
1762 	return (filtered_path[0] != '\0' ? filtered_path : NULL);
1763 }
1764 
1765 static void
1766 init_dag(Obj_Entry *root)
1767 {
1768     const Needed_Entry *needed;
1769     const Objlist_Entry *elm;
1770     DoneList donelist;
1771 
1772     if (root->dag_inited)
1773 	return;
1774     donelist_init(&donelist);
1775 
1776     /* Root object belongs to own DAG. */
1777     objlist_push_tail(&root->dldags, root);
1778     objlist_push_tail(&root->dagmembers, root);
1779     donelist_check(&donelist, root);
1780 
1781     /*
1782      * Add dependencies of root object to DAG in breadth order
1783      * by exploiting the fact that each new object get added
1784      * to the tail of the dagmembers list.
1785      */
1786     STAILQ_FOREACH(elm, &root->dagmembers, link) {
1787 	for (needed = elm->obj->needed; needed != NULL; needed = needed->next) {
1788 	    if (needed->obj == NULL || donelist_check(&donelist, needed->obj))
1789 		continue;
1790 	    objlist_push_tail(&needed->obj->dldags, root);
1791 	    objlist_push_tail(&root->dagmembers, needed->obj);
1792 	}
1793     }
1794     root->dag_inited = true;
1795 }
1796 
1797 static void
1798 process_z(Obj_Entry *root)
1799 {
1800 	const Objlist_Entry *elm;
1801 	Obj_Entry *obj;
1802 
1803 	/*
1804 	 * Walk over object DAG and process every dependent object
1805 	 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need
1806 	 * to grow their own DAG.
1807 	 *
1808 	 * For DF_1_GLOBAL, DAG is required for symbol lookups in
1809 	 * symlook_global() to work.
1810 	 *
1811 	 * For DF_1_NODELETE, the DAG should have its reference upped.
1812 	 */
1813 	STAILQ_FOREACH(elm, &root->dagmembers, link) {
1814 		obj = elm->obj;
1815 		if (obj == NULL)
1816 			continue;
1817 		if (obj->z_nodelete && !obj->ref_nodel) {
1818 			dbg("obj %s -z nodelete", obj->path);
1819 			init_dag(obj);
1820 			ref_dag(obj);
1821 			obj->ref_nodel = true;
1822 		}
1823 		if (obj->z_global && objlist_find(&list_global, obj) == NULL) {
1824 			dbg("obj %s -z global", obj->path);
1825 			objlist_push_tail(&list_global, obj);
1826 			init_dag(obj);
1827 		}
1828 	}
1829 }
1830 /*
1831  * Initialize the dynamic linker.  The argument is the address at which
1832  * the dynamic linker has been mapped into memory.  The primary task of
1833  * this function is to relocate the dynamic linker.
1834  */
1835 static void
1836 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
1837 {
1838     Obj_Entry objtmp;	/* Temporary rtld object */
1839     const Elf_Dyn *dyn_rpath;
1840     const Elf_Dyn *dyn_soname;
1841     const Elf_Dyn *dyn_runpath;
1842 
1843 #ifdef RTLD_INIT_PAGESIZES_EARLY
1844     /* The page size is required by the dynamic memory allocator. */
1845     init_pagesizes(aux_info);
1846 #endif
1847 
1848     /*
1849      * Conjure up an Obj_Entry structure for the dynamic linker.
1850      *
1851      * The "path" member can't be initialized yet because string constants
1852      * cannot yet be accessed. Below we will set it correctly.
1853      */
1854     memset(&objtmp, 0, sizeof(objtmp));
1855     objtmp.path = NULL;
1856     objtmp.rtld = true;
1857     objtmp.mapbase = mapbase;
1858 #ifdef PIC
1859     objtmp.relocbase = mapbase;
1860 #endif
1861     if (RTLD_IS_DYNAMIC()) {
1862 	objtmp.dynamic = rtld_dynamic(&objtmp);
1863 	digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath);
1864 	assert(objtmp.needed == NULL);
1865 #if !defined(__mips__)
1866 	/* MIPS has a bogus DT_TEXTREL. */
1867 	assert(!objtmp.textrel);
1868 #endif
1869 
1870 	/*
1871 	 * Temporarily put the dynamic linker entry into the object list, so
1872 	 * that symbols can be found.
1873 	 */
1874 
1875 	relocate_objects(&objtmp, true, &objtmp, 0, NULL);
1876     }
1877 
1878     /* Initialize the object list. */
1879     obj_tail = &obj_list;
1880 
1881     /* Now that non-local variables can be accesses, copy out obj_rtld. */
1882     memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
1883 
1884 #ifndef RTLD_INIT_PAGESIZES_EARLY
1885     /* The page size is required by the dynamic memory allocator. */
1886     init_pagesizes(aux_info);
1887 #endif
1888 
1889     if (aux_info[AT_OSRELDATE] != NULL)
1890 	    osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
1891 
1892     digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath);
1893 
1894     /* Replace the path with a dynamically allocated copy. */
1895     obj_rtld.path = xstrdup(PATH_RTLD);
1896 
1897     r_debug.r_brk = r_debug_state;
1898     r_debug.r_state = RT_CONSISTENT;
1899 }
1900 
1901 /*
1902  * Retrieve the array of supported page sizes.  The kernel provides the page
1903  * sizes in increasing order.
1904  */
1905 static void
1906 init_pagesizes(Elf_Auxinfo **aux_info)
1907 {
1908 	static size_t psa[MAXPAGESIZES];
1909 	int mib[2];
1910 	size_t len, size;
1911 
1912 	if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] !=
1913 	    NULL) {
1914 		size = aux_info[AT_PAGESIZESLEN]->a_un.a_val;
1915 		pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr;
1916 	} else {
1917 		len = 2;
1918 		if (sysctlnametomib("hw.pagesizes", mib, &len) == 0)
1919 			size = sizeof(psa);
1920 		else {
1921 			/* As a fallback, retrieve the base page size. */
1922 			size = sizeof(psa[0]);
1923 			if (aux_info[AT_PAGESZ] != NULL) {
1924 				psa[0] = aux_info[AT_PAGESZ]->a_un.a_val;
1925 				goto psa_filled;
1926 			} else {
1927 				mib[0] = CTL_HW;
1928 				mib[1] = HW_PAGESIZE;
1929 				len = 2;
1930 			}
1931 		}
1932 		if (sysctl(mib, len, psa, &size, NULL, 0) == -1) {
1933 			_rtld_error("sysctl for hw.pagesize(s) failed");
1934 			rtld_die();
1935 		}
1936 psa_filled:
1937 		pagesizes = psa;
1938 	}
1939 	npagesizes = size / sizeof(pagesizes[0]);
1940 	/* Discard any invalid entries at the end of the array. */
1941 	while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0)
1942 		npagesizes--;
1943 }
1944 
1945 /*
1946  * Add the init functions from a needed object list (and its recursive
1947  * needed objects) to "list".  This is not used directly; it is a helper
1948  * function for initlist_add_objects().  The write lock must be held
1949  * when this function is called.
1950  */
1951 static void
1952 initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1953 {
1954     /* Recursively process the successor needed objects. */
1955     if (needed->next != NULL)
1956 	initlist_add_neededs(needed->next, list);
1957 
1958     /* Process the current needed object. */
1959     if (needed->obj != NULL)
1960 	initlist_add_objects(needed->obj, &needed->obj->next, list);
1961 }
1962 
1963 /*
1964  * Scan all of the DAGs rooted in the range of objects from "obj" to
1965  * "tail" and add their init functions to "list".  This recurses over
1966  * the DAGs and ensure the proper init ordering such that each object's
1967  * needed libraries are initialized before the object itself.  At the
1968  * same time, this function adds the objects to the global finalization
1969  * list "list_fini" in the opposite order.  The write lock must be
1970  * held when this function is called.
1971  */
1972 static void
1973 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1974 {
1975 
1976     if (obj->init_scanned || obj->init_done)
1977 	return;
1978     obj->init_scanned = true;
1979 
1980     /* Recursively process the successor objects. */
1981     if (&obj->next != tail)
1982 	initlist_add_objects(obj->next, tail, list);
1983 
1984     /* Recursively process the needed objects. */
1985     if (obj->needed != NULL)
1986 	initlist_add_neededs(obj->needed, list);
1987     if (obj->needed_filtees != NULL)
1988 	initlist_add_neededs(obj->needed_filtees, list);
1989     if (obj->needed_aux_filtees != NULL)
1990 	initlist_add_neededs(obj->needed_aux_filtees, list);
1991 
1992     /* Add the object to the init list. */
1993     if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL ||
1994       obj->init_array != (Elf_Addr)NULL)
1995 	objlist_push_tail(list, obj);
1996 
1997     /* Add the object to the global fini list in the reverse order. */
1998     if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL)
1999       && !obj->on_fini_list) {
2000 	objlist_push_head(&list_fini, obj);
2001 	obj->on_fini_list = true;
2002     }
2003 }
2004 
2005 #ifndef FPTR_TARGET
2006 #define FPTR_TARGET(f)	((Elf_Addr) (f))
2007 #endif
2008 
2009 static void
2010 free_needed_filtees(Needed_Entry *n)
2011 {
2012     Needed_Entry *needed, *needed1;
2013 
2014     for (needed = n; needed != NULL; needed = needed->next) {
2015 	if (needed->obj != NULL) {
2016 	    dlclose(needed->obj);
2017 	    needed->obj = NULL;
2018 	}
2019     }
2020     for (needed = n; needed != NULL; needed = needed1) {
2021 	needed1 = needed->next;
2022 	free(needed);
2023     }
2024 }
2025 
2026 static void
2027 unload_filtees(Obj_Entry *obj)
2028 {
2029 
2030     free_needed_filtees(obj->needed_filtees);
2031     obj->needed_filtees = NULL;
2032     free_needed_filtees(obj->needed_aux_filtees);
2033     obj->needed_aux_filtees = NULL;
2034     obj->filtees_loaded = false;
2035 }
2036 
2037 static void
2038 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags,
2039     RtldLockState *lockstate)
2040 {
2041 
2042     for (; needed != NULL; needed = needed->next) {
2043 	needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj,
2044 	  flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) |
2045 	  RTLD_LOCAL, lockstate);
2046     }
2047 }
2048 
2049 static void
2050 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate)
2051 {
2052 
2053     lock_restart_for_upgrade(lockstate);
2054     if (!obj->filtees_loaded) {
2055 	load_filtee1(obj, obj->needed_filtees, flags, lockstate);
2056 	load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate);
2057 	obj->filtees_loaded = true;
2058     }
2059 }
2060 
2061 static int
2062 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags)
2063 {
2064     Obj_Entry *obj1;
2065 
2066     for (; needed != NULL; needed = needed->next) {
2067 	obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj,
2068 	  flags & ~RTLD_LO_NOLOAD);
2069 	if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0)
2070 	    return (-1);
2071     }
2072     return (0);
2073 }
2074 
2075 /*
2076  * Given a shared object, traverse its list of needed objects, and load
2077  * each of them.  Returns 0 on success.  Generates an error message and
2078  * returns -1 on failure.
2079  */
2080 static int
2081 load_needed_objects(Obj_Entry *first, int flags)
2082 {
2083     Obj_Entry *obj;
2084 
2085     for (obj = first;  obj != NULL;  obj = obj->next) {
2086 	if (process_needed(obj, obj->needed, flags) == -1)
2087 	    return (-1);
2088     }
2089     return (0);
2090 }
2091 
2092 static int
2093 load_preload_objects(void)
2094 {
2095     char *p = ld_preload;
2096     Obj_Entry *obj;
2097     static const char delim[] = " \t:;";
2098 
2099     if (p == NULL)
2100 	return 0;
2101 
2102     p += strspn(p, delim);
2103     while (*p != '\0') {
2104 	size_t len = strcspn(p, delim);
2105 	char savech;
2106 
2107 	savech = p[len];
2108 	p[len] = '\0';
2109 	obj = load_object(p, -1, NULL, 0);
2110 	if (obj == NULL)
2111 	    return -1;	/* XXX - cleanup */
2112 	obj->z_interpose = true;
2113 	p[len] = savech;
2114 	p += len;
2115 	p += strspn(p, delim);
2116     }
2117     LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
2118     return 0;
2119 }
2120 
2121 static const char *
2122 printable_path(const char *path)
2123 {
2124 
2125 	return (path == NULL ? "<unknown>" : path);
2126 }
2127 
2128 /*
2129  * Load a shared object into memory, if it is not already loaded.  The
2130  * object may be specified by name or by user-supplied file descriptor
2131  * fd_u. In the later case, the fd_u descriptor is not closed, but its
2132  * duplicate is.
2133  *
2134  * Returns a pointer to the Obj_Entry for the object.  Returns NULL
2135  * on failure.
2136  */
2137 static Obj_Entry *
2138 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags)
2139 {
2140     Obj_Entry *obj;
2141     int fd;
2142     struct stat sb;
2143     char *path;
2144 
2145     fd = -1;
2146     if (name != NULL) {
2147 	for (obj = obj_list->next;  obj != NULL;  obj = obj->next) {
2148 	    if (object_match_name(obj, name))
2149 		return (obj);
2150 	}
2151 
2152 	path = find_library(name, refobj, &fd);
2153 	if (path == NULL)
2154 	    return (NULL);
2155     } else
2156 	path = NULL;
2157 
2158     if (fd >= 0) {
2159 	/*
2160 	 * search_library_pathfds() opens a fresh file descriptor for the
2161 	 * library, so there is no need to dup().
2162 	 */
2163     } else if (fd_u == -1) {
2164 	/*
2165 	 * If we didn't find a match by pathname, or the name is not
2166 	 * supplied, open the file and check again by device and inode.
2167 	 * This avoids false mismatches caused by multiple links or ".."
2168 	 * in pathnames.
2169 	 *
2170 	 * To avoid a race, we open the file and use fstat() rather than
2171 	 * using stat().
2172 	 */
2173 	if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) {
2174 	    _rtld_error("Cannot open \"%s\"", path);
2175 	    free(path);
2176 	    return (NULL);
2177 	}
2178     } else {
2179 	fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0);
2180 	if (fd == -1) {
2181 	    _rtld_error("Cannot dup fd");
2182 	    free(path);
2183 	    return (NULL);
2184 	}
2185     }
2186     if (fstat(fd, &sb) == -1) {
2187 	_rtld_error("Cannot fstat \"%s\"", printable_path(path));
2188 	close(fd);
2189 	free(path);
2190 	return NULL;
2191     }
2192     for (obj = obj_list->next;  obj != NULL;  obj = obj->next)
2193 	if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
2194 	    break;
2195     if (obj != NULL && name != NULL) {
2196 	object_add_name(obj, name);
2197 	free(path);
2198 	close(fd);
2199 	return obj;
2200     }
2201     if (flags & RTLD_LO_NOLOAD) {
2202 	free(path);
2203 	close(fd);
2204 	return (NULL);
2205     }
2206 
2207     /* First use of this object, so we must map it in */
2208     obj = do_load_object(fd, name, path, &sb, flags);
2209     if (obj == NULL)
2210 	free(path);
2211     close(fd);
2212 
2213     return obj;
2214 }
2215 
2216 static Obj_Entry *
2217 do_load_object(int fd, const char *name, char *path, struct stat *sbp,
2218   int flags)
2219 {
2220     Obj_Entry *obj;
2221     struct statfs fs;
2222 
2223     /*
2224      * but first, make sure that environment variables haven't been
2225      * used to circumvent the noexec flag on a filesystem.
2226      */
2227     if (dangerous_ld_env) {
2228 	if (fstatfs(fd, &fs) != 0) {
2229 	    _rtld_error("Cannot fstatfs \"%s\"", printable_path(path));
2230 	    return NULL;
2231 	}
2232 	if (fs.f_flags & MNT_NOEXEC) {
2233 	    _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
2234 	    return NULL;
2235 	}
2236     }
2237     dbg("loading \"%s\"", printable_path(path));
2238     obj = map_object(fd, printable_path(path), sbp);
2239     if (obj == NULL)
2240         return NULL;
2241 
2242     /*
2243      * If DT_SONAME is present in the object, digest_dynamic2 already
2244      * added it to the object names.
2245      */
2246     if (name != NULL)
2247 	object_add_name(obj, name);
2248     obj->path = path;
2249     digest_dynamic(obj, 0);
2250     dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path,
2251 	obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount);
2252     if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
2253       RTLD_LO_DLOPEN) {
2254 	dbg("refusing to load non-loadable \"%s\"", obj->path);
2255 	_rtld_error("Cannot dlopen non-loadable %s", obj->path);
2256 	munmap(obj->mapbase, obj->mapsize);
2257 	obj_free(obj);
2258 	return (NULL);
2259     }
2260 
2261     obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0;
2262     *obj_tail = obj;
2263     obj_tail = &obj->next;
2264     obj_count++;
2265     obj_loads++;
2266     linkmap_add(obj);	/* for GDB & dlinfo() */
2267     max_stack_flags |= obj->stack_flags;
2268 
2269     dbg("  %p .. %p: %s", obj->mapbase,
2270          obj->mapbase + obj->mapsize - 1, obj->path);
2271     if (obj->textrel)
2272 	dbg("  WARNING: %s has impure text", obj->path);
2273     LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
2274 	obj->path);
2275 
2276     return obj;
2277 }
2278 
2279 static Obj_Entry *
2280 obj_from_addr(const void *addr)
2281 {
2282     Obj_Entry *obj;
2283 
2284     for (obj = obj_list;  obj != NULL;  obj = obj->next) {
2285 	if (addr < (void *) obj->mapbase)
2286 	    continue;
2287 	if (addr < (void *) (obj->mapbase + obj->mapsize))
2288 	    return obj;
2289     }
2290     return NULL;
2291 }
2292 
2293 static void
2294 preinit_main(void)
2295 {
2296     Elf_Addr *preinit_addr;
2297     int index;
2298 
2299     preinit_addr = (Elf_Addr *)obj_main->preinit_array;
2300     if (preinit_addr == NULL)
2301 	return;
2302 
2303     for (index = 0; index < obj_main->preinit_array_num; index++) {
2304 	if (preinit_addr[index] != 0 && preinit_addr[index] != 1) {
2305 	    dbg("calling preinit function for %s at %p", obj_main->path,
2306 	      (void *)preinit_addr[index]);
2307 	    LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index],
2308 	      0, 0, obj_main->path);
2309 	    call_init_pointer(obj_main, preinit_addr[index]);
2310 	}
2311     }
2312 }
2313 
2314 /*
2315  * Call the finalization functions for each of the objects in "list"
2316  * belonging to the DAG of "root" and referenced once. If NULL "root"
2317  * is specified, every finalization function will be called regardless
2318  * of the reference count and the list elements won't be freed. All of
2319  * the objects are expected to have non-NULL fini functions.
2320  */
2321 static void
2322 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
2323 {
2324     Objlist_Entry *elm;
2325     char *saved_msg;
2326     Elf_Addr *fini_addr;
2327     int index;
2328 
2329     assert(root == NULL || root->refcount == 1);
2330 
2331     /*
2332      * Preserve the current error message since a fini function might
2333      * call into the dynamic linker and overwrite it.
2334      */
2335     saved_msg = errmsg_save();
2336     do {
2337 	STAILQ_FOREACH(elm, list, link) {
2338 	    if (root != NULL && (elm->obj->refcount != 1 ||
2339 	      objlist_find(&root->dagmembers, elm->obj) == NULL))
2340 		continue;
2341 	    /* Remove object from fini list to prevent recursive invocation. */
2342 	    STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2343 	    /*
2344 	     * XXX: If a dlopen() call references an object while the
2345 	     * fini function is in progress, we might end up trying to
2346 	     * unload the referenced object in dlclose() or the object
2347 	     * won't be unloaded although its fini function has been
2348 	     * called.
2349 	     */
2350 	    lock_release(rtld_bind_lock, lockstate);
2351 
2352 	    /*
2353 	     * It is legal to have both DT_FINI and DT_FINI_ARRAY defined.
2354 	     * When this happens, DT_FINI_ARRAY is processed first.
2355 	     */
2356 	    fini_addr = (Elf_Addr *)elm->obj->fini_array;
2357 	    if (fini_addr != NULL && elm->obj->fini_array_num > 0) {
2358 		for (index = elm->obj->fini_array_num - 1; index >= 0;
2359 		  index--) {
2360 		    if (fini_addr[index] != 0 && fini_addr[index] != 1) {
2361 			dbg("calling fini function for %s at %p",
2362 			    elm->obj->path, (void *)fini_addr[index]);
2363 			LD_UTRACE(UTRACE_FINI_CALL, elm->obj,
2364 			    (void *)fini_addr[index], 0, 0, elm->obj->path);
2365 			call_initfini_pointer(elm->obj, fini_addr[index]);
2366 		    }
2367 		}
2368 	    }
2369 	    if (elm->obj->fini != (Elf_Addr)NULL) {
2370 		dbg("calling fini function for %s at %p", elm->obj->path,
2371 		    (void *)elm->obj->fini);
2372 		LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini,
2373 		    0, 0, elm->obj->path);
2374 		call_initfini_pointer(elm->obj, elm->obj->fini);
2375 	    }
2376 	    wlock_acquire(rtld_bind_lock, lockstate);
2377 	    /* No need to free anything if process is going down. */
2378 	    if (root != NULL)
2379 	    	free(elm);
2380 	    /*
2381 	     * We must restart the list traversal after every fini call
2382 	     * because a dlclose() call from the fini function or from
2383 	     * another thread might have modified the reference counts.
2384 	     */
2385 	    break;
2386 	}
2387     } while (elm != NULL);
2388     errmsg_restore(saved_msg);
2389 }
2390 
2391 /*
2392  * Call the initialization functions for each of the objects in
2393  * "list".  All of the objects are expected to have non-NULL init
2394  * functions.
2395  */
2396 static void
2397 objlist_call_init(Objlist *list, RtldLockState *lockstate)
2398 {
2399     Objlist_Entry *elm;
2400     Obj_Entry *obj;
2401     char *saved_msg;
2402     Elf_Addr *init_addr;
2403     int index;
2404 
2405     /*
2406      * Clean init_scanned flag so that objects can be rechecked and
2407      * possibly initialized earlier if any of vectors called below
2408      * cause the change by using dlopen.
2409      */
2410     for (obj = obj_list;  obj != NULL;  obj = obj->next)
2411 	obj->init_scanned = false;
2412 
2413     /*
2414      * Preserve the current error message since an init function might
2415      * call into the dynamic linker and overwrite it.
2416      */
2417     saved_msg = errmsg_save();
2418     STAILQ_FOREACH(elm, list, link) {
2419 	if (elm->obj->init_done) /* Initialized early. */
2420 	    continue;
2421 	/*
2422 	 * Race: other thread might try to use this object before current
2423 	 * one completes the initilization. Not much can be done here
2424 	 * without better locking.
2425 	 */
2426 	elm->obj->init_done = true;
2427 	lock_release(rtld_bind_lock, lockstate);
2428 
2429         /*
2430          * It is legal to have both DT_INIT and DT_INIT_ARRAY defined.
2431          * When this happens, DT_INIT is processed first.
2432          */
2433 	if (elm->obj->init != (Elf_Addr)NULL) {
2434 	    dbg("calling init function for %s at %p", elm->obj->path,
2435 	        (void *)elm->obj->init);
2436 	    LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init,
2437 	        0, 0, elm->obj->path);
2438 	    call_initfini_pointer(elm->obj, elm->obj->init);
2439 	}
2440 	init_addr = (Elf_Addr *)elm->obj->init_array;
2441 	if (init_addr != NULL) {
2442 	    for (index = 0; index < elm->obj->init_array_num; index++) {
2443 		if (init_addr[index] != 0 && init_addr[index] != 1) {
2444 		    dbg("calling init function for %s at %p", elm->obj->path,
2445 			(void *)init_addr[index]);
2446 		    LD_UTRACE(UTRACE_INIT_CALL, elm->obj,
2447 			(void *)init_addr[index], 0, 0, elm->obj->path);
2448 		    call_init_pointer(elm->obj, init_addr[index]);
2449 		}
2450 	    }
2451 	}
2452 	wlock_acquire(rtld_bind_lock, lockstate);
2453     }
2454     errmsg_restore(saved_msg);
2455 }
2456 
2457 static void
2458 objlist_clear(Objlist *list)
2459 {
2460     Objlist_Entry *elm;
2461 
2462     while (!STAILQ_EMPTY(list)) {
2463 	elm = STAILQ_FIRST(list);
2464 	STAILQ_REMOVE_HEAD(list, link);
2465 	free(elm);
2466     }
2467 }
2468 
2469 static Objlist_Entry *
2470 objlist_find(Objlist *list, const Obj_Entry *obj)
2471 {
2472     Objlist_Entry *elm;
2473 
2474     STAILQ_FOREACH(elm, list, link)
2475 	if (elm->obj == obj)
2476 	    return elm;
2477     return NULL;
2478 }
2479 
2480 static void
2481 objlist_init(Objlist *list)
2482 {
2483     STAILQ_INIT(list);
2484 }
2485 
2486 static void
2487 objlist_push_head(Objlist *list, Obj_Entry *obj)
2488 {
2489     Objlist_Entry *elm;
2490 
2491     elm = NEW(Objlist_Entry);
2492     elm->obj = obj;
2493     STAILQ_INSERT_HEAD(list, elm, link);
2494 }
2495 
2496 static void
2497 objlist_push_tail(Objlist *list, Obj_Entry *obj)
2498 {
2499     Objlist_Entry *elm;
2500 
2501     elm = NEW(Objlist_Entry);
2502     elm->obj = obj;
2503     STAILQ_INSERT_TAIL(list, elm, link);
2504 }
2505 
2506 static void
2507 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj)
2508 {
2509 	Objlist_Entry *elm, *listelm;
2510 
2511 	STAILQ_FOREACH(listelm, list, link) {
2512 		if (listelm->obj == listobj)
2513 			break;
2514 	}
2515 	elm = NEW(Objlist_Entry);
2516 	elm->obj = obj;
2517 	if (listelm != NULL)
2518 		STAILQ_INSERT_AFTER(list, listelm, elm, link);
2519 	else
2520 		STAILQ_INSERT_TAIL(list, elm, link);
2521 }
2522 
2523 static void
2524 objlist_remove(Objlist *list, Obj_Entry *obj)
2525 {
2526     Objlist_Entry *elm;
2527 
2528     if ((elm = objlist_find(list, obj)) != NULL) {
2529 	STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2530 	free(elm);
2531     }
2532 }
2533 
2534 /*
2535  * Relocate dag rooted in the specified object.
2536  * Returns 0 on success, or -1 on failure.
2537  */
2538 
2539 static int
2540 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj,
2541     int flags, RtldLockState *lockstate)
2542 {
2543 	Objlist_Entry *elm;
2544 	int error;
2545 
2546 	error = 0;
2547 	STAILQ_FOREACH(elm, &root->dagmembers, link) {
2548 		error = relocate_object(elm->obj, bind_now, rtldobj, flags,
2549 		    lockstate);
2550 		if (error == -1)
2551 			break;
2552 	}
2553 	return (error);
2554 }
2555 
2556 /*
2557  * Relocate single object.
2558  * Returns 0 on success, or -1 on failure.
2559  */
2560 static int
2561 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
2562     int flags, RtldLockState *lockstate)
2563 {
2564 
2565 	if (obj->relocated)
2566 		return (0);
2567 	obj->relocated = true;
2568 	if (obj != rtldobj)
2569 		dbg("relocating \"%s\"", obj->path);
2570 
2571 	if (obj->symtab == NULL || obj->strtab == NULL ||
2572 	    !(obj->valid_hash_sysv || obj->valid_hash_gnu)) {
2573 		_rtld_error("%s: Shared object has no run-time symbol table",
2574 			    obj->path);
2575 		return (-1);
2576 	}
2577 
2578 	if (obj->textrel) {
2579 		/* There are relocations to the write-protected text segment. */
2580 		if (mprotect(obj->mapbase, obj->textsize,
2581 		    PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
2582 			_rtld_error("%s: Cannot write-enable text segment: %s",
2583 			    obj->path, rtld_strerror(errno));
2584 			return (-1);
2585 		}
2586 	}
2587 
2588 	/* Process the non-PLT non-IFUNC relocations. */
2589 	if (reloc_non_plt(obj, rtldobj, flags, lockstate))
2590 		return (-1);
2591 
2592 	if (obj->textrel) {	/* Re-protected the text segment. */
2593 		if (mprotect(obj->mapbase, obj->textsize,
2594 		    PROT_READ|PROT_EXEC) == -1) {
2595 			_rtld_error("%s: Cannot write-protect text segment: %s",
2596 			    obj->path, rtld_strerror(errno));
2597 			return (-1);
2598 		}
2599 	}
2600 
2601 	/* Set the special PLT or GOT entries. */
2602 	init_pltgot(obj);
2603 
2604 	/* Process the PLT relocations. */
2605 	if (reloc_plt(obj) == -1)
2606 		return (-1);
2607 	/* Relocate the jump slots if we are doing immediate binding. */
2608 	if (obj->bind_now || bind_now)
2609 		if (reloc_jmpslots(obj, flags, lockstate) == -1)
2610 			return (-1);
2611 
2612 	/*
2613 	 * Process the non-PLT IFUNC relocations.  The relocations are
2614 	 * processed in two phases, because IFUNC resolvers may
2615 	 * reference other symbols, which must be readily processed
2616 	 * before resolvers are called.
2617 	 */
2618 	if (obj->non_plt_gnu_ifunc &&
2619 	    reloc_non_plt(obj, rtldobj, flags | SYMLOOK_IFUNC, lockstate))
2620 		return (-1);
2621 
2622 	if (obj->relro_size > 0) {
2623 		if (mprotect(obj->relro_page, obj->relro_size,
2624 		    PROT_READ) == -1) {
2625 			_rtld_error("%s: Cannot enforce relro protection: %s",
2626 			    obj->path, rtld_strerror(errno));
2627 			return (-1);
2628 		}
2629 	}
2630 
2631 	/*
2632 	 * Set up the magic number and version in the Obj_Entry.  These
2633 	 * were checked in the crt1.o from the original ElfKit, so we
2634 	 * set them for backward compatibility.
2635 	 */
2636 	obj->magic = RTLD_MAGIC;
2637 	obj->version = RTLD_VERSION;
2638 
2639 	return (0);
2640 }
2641 
2642 /*
2643  * Relocate newly-loaded shared objects.  The argument is a pointer to
2644  * the Obj_Entry for the first such object.  All objects from the first
2645  * to the end of the list of objects are relocated.  Returns 0 on success,
2646  * or -1 on failure.
2647  */
2648 static int
2649 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
2650     int flags, RtldLockState *lockstate)
2651 {
2652 	Obj_Entry *obj;
2653 	int error;
2654 
2655 	for (error = 0, obj = first;  obj != NULL;  obj = obj->next) {
2656 		error = relocate_object(obj, bind_now, rtldobj, flags,
2657 		    lockstate);
2658 		if (error == -1)
2659 			break;
2660 	}
2661 	return (error);
2662 }
2663 
2664 /*
2665  * The handling of R_MACHINE_IRELATIVE relocations and jumpslots
2666  * referencing STT_GNU_IFUNC symbols is postponed till the other
2667  * relocations are done.  The indirect functions specified as
2668  * ifunc are allowed to call other symbols, so we need to have
2669  * objects relocated before asking for resolution from indirects.
2670  *
2671  * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion,
2672  * instead of the usual lazy handling of PLT slots.  It is
2673  * consistent with how GNU does it.
2674  */
2675 static int
2676 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags,
2677     RtldLockState *lockstate)
2678 {
2679 	if (obj->irelative && reloc_iresolve(obj, lockstate) == -1)
2680 		return (-1);
2681 	if ((obj->bind_now || bind_now) && obj->gnu_ifunc &&
2682 	    reloc_gnu_ifunc(obj, flags, lockstate) == -1)
2683 		return (-1);
2684 	return (0);
2685 }
2686 
2687 static int
2688 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags,
2689     RtldLockState *lockstate)
2690 {
2691 	Obj_Entry *obj;
2692 
2693 	for (obj = first;  obj != NULL;  obj = obj->next) {
2694 		if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1)
2695 			return (-1);
2696 	}
2697 	return (0);
2698 }
2699 
2700 static int
2701 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags,
2702     RtldLockState *lockstate)
2703 {
2704 	Objlist_Entry *elm;
2705 
2706 	STAILQ_FOREACH(elm, list, link) {
2707 		if (resolve_object_ifunc(elm->obj, bind_now, flags,
2708 		    lockstate) == -1)
2709 			return (-1);
2710 	}
2711 	return (0);
2712 }
2713 
2714 /*
2715  * Cleanup procedure.  It will be called (by the atexit mechanism) just
2716  * before the process exits.
2717  */
2718 static void
2719 rtld_exit(void)
2720 {
2721     RtldLockState lockstate;
2722 
2723     wlock_acquire(rtld_bind_lock, &lockstate);
2724     dbg("rtld_exit()");
2725     objlist_call_fini(&list_fini, NULL, &lockstate);
2726     /* No need to remove the items from the list, since we are exiting. */
2727     if (!libmap_disable)
2728         lm_fini();
2729     lock_release(rtld_bind_lock, &lockstate);
2730 }
2731 
2732 /*
2733  * Iterate over a search path, translate each element, and invoke the
2734  * callback on the result.
2735  */
2736 static void *
2737 path_enumerate(const char *path, path_enum_proc callback, void *arg)
2738 {
2739     const char *trans;
2740     if (path == NULL)
2741 	return (NULL);
2742 
2743     path += strspn(path, ":;");
2744     while (*path != '\0') {
2745 	size_t len;
2746 	char  *res;
2747 
2748 	len = strcspn(path, ":;");
2749 	trans = lm_findn(NULL, path, len);
2750 	if (trans)
2751 	    res = callback(trans, strlen(trans), arg);
2752 	else
2753 	    res = callback(path, len, arg);
2754 
2755 	if (res != NULL)
2756 	    return (res);
2757 
2758 	path += len;
2759 	path += strspn(path, ":;");
2760     }
2761 
2762     return (NULL);
2763 }
2764 
2765 struct try_library_args {
2766     const char	*name;
2767     size_t	 namelen;
2768     char	*buffer;
2769     size_t	 buflen;
2770 };
2771 
2772 static void *
2773 try_library_path(const char *dir, size_t dirlen, void *param)
2774 {
2775     struct try_library_args *arg;
2776 
2777     arg = param;
2778     if (*dir == '/' || trust) {
2779 	char *pathname;
2780 
2781 	if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
2782 		return (NULL);
2783 
2784 	pathname = arg->buffer;
2785 	strncpy(pathname, dir, dirlen);
2786 	pathname[dirlen] = '/';
2787 	strcpy(pathname + dirlen + 1, arg->name);
2788 
2789 	dbg("  Trying \"%s\"", pathname);
2790 	if (access(pathname, F_OK) == 0) {		/* We found it */
2791 	    pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
2792 	    strcpy(pathname, arg->buffer);
2793 	    return (pathname);
2794 	}
2795     }
2796     return (NULL);
2797 }
2798 
2799 static char *
2800 search_library_path(const char *name, const char *path)
2801 {
2802     char *p;
2803     struct try_library_args arg;
2804 
2805     if (path == NULL)
2806 	return NULL;
2807 
2808     arg.name = name;
2809     arg.namelen = strlen(name);
2810     arg.buffer = xmalloc(PATH_MAX);
2811     arg.buflen = PATH_MAX;
2812 
2813     p = path_enumerate(path, try_library_path, &arg);
2814 
2815     free(arg.buffer);
2816 
2817     return (p);
2818 }
2819 
2820 
2821 /*
2822  * Finds the library with the given name using the directory descriptors
2823  * listed in the LD_LIBRARY_PATH_FDS environment variable.
2824  *
2825  * Returns a freshly-opened close-on-exec file descriptor for the library,
2826  * or -1 if the library cannot be found.
2827  */
2828 static char *
2829 search_library_pathfds(const char *name, const char *path, int *fdp)
2830 {
2831 	char *envcopy, *fdstr, *found, *last_token;
2832 	size_t len;
2833 	int dirfd, fd;
2834 
2835 	dbg("%s('%s', '%s', fdp)", __func__, name, path);
2836 
2837 	/* Don't load from user-specified libdirs into setuid binaries. */
2838 	if (!trust)
2839 		return (NULL);
2840 
2841 	/* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */
2842 	if (path == NULL)
2843 		return (NULL);
2844 
2845 	/* LD_LIBRARY_PATH_FDS only works with relative paths. */
2846 	if (name[0] == '/') {
2847 		dbg("Absolute path (%s) passed to %s", name, __func__);
2848 		return (NULL);
2849 	}
2850 
2851 	/*
2852 	 * Use strtok_r() to walk the FD:FD:FD list.  This requires a local
2853 	 * copy of the path, as strtok_r rewrites separator tokens
2854 	 * with '\0'.
2855 	 */
2856 	found = NULL;
2857 	envcopy = xstrdup(path);
2858 	for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL;
2859 	    fdstr = strtok_r(NULL, ":", &last_token)) {
2860 		dirfd = parse_libdir(fdstr);
2861 		if (dirfd < 0)
2862 			break;
2863 		fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY);
2864 		if (fd >= 0) {
2865 			*fdp = fd;
2866 			len = strlen(fdstr) + strlen(name) + 3;
2867 			found = xmalloc(len);
2868 			if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) {
2869 				_rtld_error("error generating '%d/%s'",
2870 				    dirfd, name);
2871 				rtld_die();
2872 			}
2873 			dbg("open('%s') => %d", found, fd);
2874 			break;
2875 		}
2876 	}
2877 	free(envcopy);
2878 
2879 	return (found);
2880 }
2881 
2882 
2883 int
2884 dlclose(void *handle)
2885 {
2886     Obj_Entry *root;
2887     RtldLockState lockstate;
2888 
2889     wlock_acquire(rtld_bind_lock, &lockstate);
2890     root = dlcheck(handle);
2891     if (root == NULL) {
2892 	lock_release(rtld_bind_lock, &lockstate);
2893 	return -1;
2894     }
2895     LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
2896 	root->path);
2897 
2898     /* Unreference the object and its dependencies. */
2899     root->dl_refcount--;
2900 
2901     if (root->refcount == 1) {
2902 	/*
2903 	 * The object will be no longer referenced, so we must unload it.
2904 	 * First, call the fini functions.
2905 	 */
2906 	objlist_call_fini(&list_fini, root, &lockstate);
2907 
2908 	unref_dag(root);
2909 
2910 	/* Finish cleaning up the newly-unreferenced objects. */
2911 	GDB_STATE(RT_DELETE,&root->linkmap);
2912 	unload_object(root);
2913 	GDB_STATE(RT_CONSISTENT,NULL);
2914     } else
2915 	unref_dag(root);
2916 
2917     LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
2918     lock_release(rtld_bind_lock, &lockstate);
2919     return 0;
2920 }
2921 
2922 char *
2923 dlerror(void)
2924 {
2925     char *msg = error_message;
2926     error_message = NULL;
2927     return msg;
2928 }
2929 
2930 /*
2931  * This function is deprecated and has no effect.
2932  */
2933 void
2934 dllockinit(void *context,
2935 	   void *(*lock_create)(void *context),
2936            void (*rlock_acquire)(void *lock),
2937            void (*wlock_acquire)(void *lock),
2938            void (*lock_release)(void *lock),
2939            void (*lock_destroy)(void *lock),
2940 	   void (*context_destroy)(void *context))
2941 {
2942     static void *cur_context;
2943     static void (*cur_context_destroy)(void *);
2944 
2945     /* Just destroy the context from the previous call, if necessary. */
2946     if (cur_context_destroy != NULL)
2947 	cur_context_destroy(cur_context);
2948     cur_context = context;
2949     cur_context_destroy = context_destroy;
2950 }
2951 
2952 void *
2953 dlopen(const char *name, int mode)
2954 {
2955 
2956 	return (rtld_dlopen(name, -1, mode));
2957 }
2958 
2959 void *
2960 fdlopen(int fd, int mode)
2961 {
2962 
2963 	return (rtld_dlopen(NULL, fd, mode));
2964 }
2965 
2966 static void *
2967 rtld_dlopen(const char *name, int fd, int mode)
2968 {
2969     RtldLockState lockstate;
2970     int lo_flags;
2971 
2972     LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
2973     ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
2974     if (ld_tracing != NULL) {
2975 	rlock_acquire(rtld_bind_lock, &lockstate);
2976 	if (sigsetjmp(lockstate.env, 0) != 0)
2977 	    lock_upgrade(rtld_bind_lock, &lockstate);
2978 	environ = (char **)*get_program_var_addr("environ", &lockstate);
2979 	lock_release(rtld_bind_lock, &lockstate);
2980     }
2981     lo_flags = RTLD_LO_DLOPEN;
2982     if (mode & RTLD_NODELETE)
2983 	    lo_flags |= RTLD_LO_NODELETE;
2984     if (mode & RTLD_NOLOAD)
2985 	    lo_flags |= RTLD_LO_NOLOAD;
2986     if (ld_tracing != NULL)
2987 	    lo_flags |= RTLD_LO_TRACE;
2988 
2989     return (dlopen_object(name, fd, obj_main, lo_flags,
2990       mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL));
2991 }
2992 
2993 static void
2994 dlopen_cleanup(Obj_Entry *obj)
2995 {
2996 
2997 	obj->dl_refcount--;
2998 	unref_dag(obj);
2999 	if (obj->refcount == 0)
3000 		unload_object(obj);
3001 }
3002 
3003 static Obj_Entry *
3004 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags,
3005     int mode, RtldLockState *lockstate)
3006 {
3007     Obj_Entry **old_obj_tail;
3008     Obj_Entry *obj;
3009     Objlist initlist;
3010     RtldLockState mlockstate;
3011     int result;
3012 
3013     objlist_init(&initlist);
3014 
3015     if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) {
3016 	wlock_acquire(rtld_bind_lock, &mlockstate);
3017 	lockstate = &mlockstate;
3018     }
3019     GDB_STATE(RT_ADD,NULL);
3020 
3021     old_obj_tail = obj_tail;
3022     obj = NULL;
3023     if (name == NULL && fd == -1) {
3024 	obj = obj_main;
3025 	obj->refcount++;
3026     } else {
3027 	obj = load_object(name, fd, refobj, lo_flags);
3028     }
3029 
3030     if (obj) {
3031 	obj->dl_refcount++;
3032 	if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
3033 	    objlist_push_tail(&list_global, obj);
3034 	if (*old_obj_tail != NULL) {		/* We loaded something new. */
3035 	    assert(*old_obj_tail == obj);
3036 	    result = load_needed_objects(obj,
3037 		lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY));
3038 	    init_dag(obj);
3039 	    ref_dag(obj);
3040 	    if (result != -1)
3041 		result = rtld_verify_versions(&obj->dagmembers);
3042 	    if (result != -1 && ld_tracing)
3043 		goto trace;
3044 	    if (result == -1 || relocate_object_dag(obj,
3045 	      (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld,
3046 	      (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
3047 	      lockstate) == -1) {
3048 		dlopen_cleanup(obj);
3049 		obj = NULL;
3050 	    } else if (lo_flags & RTLD_LO_EARLY) {
3051 		/*
3052 		 * Do not call the init functions for early loaded
3053 		 * filtees.  The image is still not initialized enough
3054 		 * for them to work.
3055 		 *
3056 		 * Our object is found by the global object list and
3057 		 * will be ordered among all init calls done right
3058 		 * before transferring control to main.
3059 		 */
3060 	    } else {
3061 		/* Make list of init functions to call. */
3062 		initlist_add_objects(obj, &obj->next, &initlist);
3063 	    }
3064 	    /*
3065 	     * Process all no_delete or global objects here, given
3066 	     * them own DAGs to prevent their dependencies from being
3067 	     * unloaded.  This has to be done after we have loaded all
3068 	     * of the dependencies, so that we do not miss any.
3069 	     */
3070 	    if (obj != NULL)
3071 		process_z(obj);
3072 	} else {
3073 	    /*
3074 	     * Bump the reference counts for objects on this DAG.  If
3075 	     * this is the first dlopen() call for the object that was
3076 	     * already loaded as a dependency, initialize the dag
3077 	     * starting at it.
3078 	     */
3079 	    init_dag(obj);
3080 	    ref_dag(obj);
3081 
3082 	    if ((lo_flags & RTLD_LO_TRACE) != 0)
3083 		goto trace;
3084 	}
3085 	if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
3086 	  obj->z_nodelete) && !obj->ref_nodel) {
3087 	    dbg("obj %s nodelete", obj->path);
3088 	    ref_dag(obj);
3089 	    obj->z_nodelete = obj->ref_nodel = true;
3090 	}
3091     }
3092 
3093     LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
3094 	name);
3095     GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
3096 
3097     if (!(lo_flags & RTLD_LO_EARLY)) {
3098 	map_stacks_exec(lockstate);
3099     }
3100 
3101     if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW,
3102       (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
3103       lockstate) == -1) {
3104 	objlist_clear(&initlist);
3105 	dlopen_cleanup(obj);
3106 	if (lockstate == &mlockstate)
3107 	    lock_release(rtld_bind_lock, lockstate);
3108 	return (NULL);
3109     }
3110 
3111     if (!(lo_flags & RTLD_LO_EARLY)) {
3112 	/* Call the init functions. */
3113 	objlist_call_init(&initlist, lockstate);
3114     }
3115     objlist_clear(&initlist);
3116     if (lockstate == &mlockstate)
3117 	lock_release(rtld_bind_lock, lockstate);
3118     return obj;
3119 trace:
3120     trace_loaded_objects(obj);
3121     if (lockstate == &mlockstate)
3122 	lock_release(rtld_bind_lock, lockstate);
3123     exit(0);
3124 }
3125 
3126 static void *
3127 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
3128     int flags)
3129 {
3130     DoneList donelist;
3131     const Obj_Entry *obj, *defobj;
3132     const Elf_Sym *def;
3133     SymLook req;
3134     RtldLockState lockstate;
3135     tls_index ti;
3136     void *sym;
3137     int res;
3138 
3139     def = NULL;
3140     defobj = NULL;
3141     symlook_init(&req, name);
3142     req.ventry = ve;
3143     req.flags = flags | SYMLOOK_IN_PLT;
3144     req.lockstate = &lockstate;
3145 
3146     LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name);
3147     rlock_acquire(rtld_bind_lock, &lockstate);
3148     if (sigsetjmp(lockstate.env, 0) != 0)
3149 	    lock_upgrade(rtld_bind_lock, &lockstate);
3150     if (handle == NULL || handle == RTLD_NEXT ||
3151 	handle == RTLD_DEFAULT || handle == RTLD_SELF) {
3152 
3153 	if ((obj = obj_from_addr(retaddr)) == NULL) {
3154 	    _rtld_error("Cannot determine caller's shared object");
3155 	    lock_release(rtld_bind_lock, &lockstate);
3156 	    LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3157 	    return NULL;
3158 	}
3159 	if (handle == NULL) {	/* Just the caller's shared object. */
3160 	    res = symlook_obj(&req, obj);
3161 	    if (res == 0) {
3162 		def = req.sym_out;
3163 		defobj = req.defobj_out;
3164 	    }
3165 	} else if (handle == RTLD_NEXT || /* Objects after caller's */
3166 		   handle == RTLD_SELF) { /* ... caller included */
3167 	    if (handle == RTLD_NEXT)
3168 		obj = obj->next;
3169 	    for (; obj != NULL; obj = obj->next) {
3170 		res = symlook_obj(&req, obj);
3171 		if (res == 0) {
3172 		    if (def == NULL ||
3173 		      ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) {
3174 			def = req.sym_out;
3175 			defobj = req.defobj_out;
3176 			if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3177 			    break;
3178 		    }
3179 		}
3180 	    }
3181 	    /*
3182 	     * Search the dynamic linker itself, and possibly resolve the
3183 	     * symbol from there.  This is how the application links to
3184 	     * dynamic linker services such as dlopen.
3185 	     */
3186 	    if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3187 		res = symlook_obj(&req, &obj_rtld);
3188 		if (res == 0) {
3189 		    def = req.sym_out;
3190 		    defobj = req.defobj_out;
3191 		}
3192 	    }
3193 	} else {
3194 	    assert(handle == RTLD_DEFAULT);
3195 	    res = symlook_default(&req, obj);
3196 	    if (res == 0) {
3197 		defobj = req.defobj_out;
3198 		def = req.sym_out;
3199 	    }
3200 	}
3201     } else {
3202 	if ((obj = dlcheck(handle)) == NULL) {
3203 	    lock_release(rtld_bind_lock, &lockstate);
3204 	    LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3205 	    return NULL;
3206 	}
3207 
3208 	donelist_init(&donelist);
3209 	if (obj->mainprog) {
3210             /* Handle obtained by dlopen(NULL, ...) implies global scope. */
3211 	    res = symlook_global(&req, &donelist);
3212 	    if (res == 0) {
3213 		def = req.sym_out;
3214 		defobj = req.defobj_out;
3215 	    }
3216 	    /*
3217 	     * Search the dynamic linker itself, and possibly resolve the
3218 	     * symbol from there.  This is how the application links to
3219 	     * dynamic linker services such as dlopen.
3220 	     */
3221 	    if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3222 		res = symlook_obj(&req, &obj_rtld);
3223 		if (res == 0) {
3224 		    def = req.sym_out;
3225 		    defobj = req.defobj_out;
3226 		}
3227 	    }
3228 	}
3229 	else {
3230 	    /* Search the whole DAG rooted at the given object. */
3231 	    res = symlook_list(&req, &obj->dagmembers, &donelist);
3232 	    if (res == 0) {
3233 		def = req.sym_out;
3234 		defobj = req.defobj_out;
3235 	    }
3236 	}
3237     }
3238 
3239     if (def != NULL) {
3240 	lock_release(rtld_bind_lock, &lockstate);
3241 
3242 	/*
3243 	 * The value required by the caller is derived from the value
3244 	 * of the symbol. this is simply the relocated value of the
3245 	 * symbol.
3246 	 */
3247 	if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
3248 	    sym = make_function_pointer(def, defobj);
3249 	else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
3250 	    sym = rtld_resolve_ifunc(defobj, def);
3251 	else if (ELF_ST_TYPE(def->st_info) == STT_TLS) {
3252 	    ti.ti_module = defobj->tlsindex;
3253 	    ti.ti_offset = def->st_value;
3254 	    sym = __tls_get_addr(&ti);
3255 	} else
3256 	    sym = defobj->relocbase + def->st_value;
3257 	LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name);
3258 	return (sym);
3259     }
3260 
3261     _rtld_error("Undefined symbol \"%s\"", name);
3262     lock_release(rtld_bind_lock, &lockstate);
3263     LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3264     return NULL;
3265 }
3266 
3267 void *
3268 dlsym(void *handle, const char *name)
3269 {
3270 	return do_dlsym(handle, name, __builtin_return_address(0), NULL,
3271 	    SYMLOOK_DLSYM);
3272 }
3273 
3274 dlfunc_t
3275 dlfunc(void *handle, const char *name)
3276 {
3277 	union {
3278 		void *d;
3279 		dlfunc_t f;
3280 	} rv;
3281 
3282 	rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
3283 	    SYMLOOK_DLSYM);
3284 	return (rv.f);
3285 }
3286 
3287 void *
3288 dlvsym(void *handle, const char *name, const char *version)
3289 {
3290 	Ver_Entry ventry;
3291 
3292 	ventry.name = version;
3293 	ventry.file = NULL;
3294 	ventry.hash = elf_hash(version);
3295 	ventry.flags= 0;
3296 	return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
3297 	    SYMLOOK_DLSYM);
3298 }
3299 
3300 int
3301 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
3302 {
3303     const Obj_Entry *obj;
3304     RtldLockState lockstate;
3305 
3306     rlock_acquire(rtld_bind_lock, &lockstate);
3307     obj = obj_from_addr(addr);
3308     if (obj == NULL) {
3309         _rtld_error("No shared object contains address");
3310 	lock_release(rtld_bind_lock, &lockstate);
3311         return (0);
3312     }
3313     rtld_fill_dl_phdr_info(obj, phdr_info);
3314     lock_release(rtld_bind_lock, &lockstate);
3315     return (1);
3316 }
3317 
3318 int
3319 dladdr(const void *addr, Dl_info *info)
3320 {
3321     const Obj_Entry *obj;
3322     const Elf_Sym *def;
3323     void *symbol_addr;
3324     unsigned long symoffset;
3325     RtldLockState lockstate;
3326 
3327     rlock_acquire(rtld_bind_lock, &lockstate);
3328     obj = obj_from_addr(addr);
3329     if (obj == NULL) {
3330         _rtld_error("No shared object contains address");
3331 	lock_release(rtld_bind_lock, &lockstate);
3332         return 0;
3333     }
3334     info->dli_fname = obj->path;
3335     info->dli_fbase = obj->mapbase;
3336     info->dli_saddr = (void *)0;
3337     info->dli_sname = NULL;
3338 
3339     /*
3340      * Walk the symbol list looking for the symbol whose address is
3341      * closest to the address sent in.
3342      */
3343     for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) {
3344         def = obj->symtab + symoffset;
3345 
3346         /*
3347          * For skip the symbol if st_shndx is either SHN_UNDEF or
3348          * SHN_COMMON.
3349          */
3350         if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
3351             continue;
3352 
3353         /*
3354          * If the symbol is greater than the specified address, or if it
3355          * is further away from addr than the current nearest symbol,
3356          * then reject it.
3357          */
3358         symbol_addr = obj->relocbase + def->st_value;
3359         if (symbol_addr > addr || symbol_addr < info->dli_saddr)
3360             continue;
3361 
3362         /* Update our idea of the nearest symbol. */
3363         info->dli_sname = obj->strtab + def->st_name;
3364         info->dli_saddr = symbol_addr;
3365 
3366         /* Exact match? */
3367         if (info->dli_saddr == addr)
3368             break;
3369     }
3370     lock_release(rtld_bind_lock, &lockstate);
3371     return 1;
3372 }
3373 
3374 int
3375 dlinfo(void *handle, int request, void *p)
3376 {
3377     const Obj_Entry *obj;
3378     RtldLockState lockstate;
3379     int error;
3380 
3381     rlock_acquire(rtld_bind_lock, &lockstate);
3382 
3383     if (handle == NULL || handle == RTLD_SELF) {
3384 	void *retaddr;
3385 
3386 	retaddr = __builtin_return_address(0);	/* __GNUC__ only */
3387 	if ((obj = obj_from_addr(retaddr)) == NULL)
3388 	    _rtld_error("Cannot determine caller's shared object");
3389     } else
3390 	obj = dlcheck(handle);
3391 
3392     if (obj == NULL) {
3393 	lock_release(rtld_bind_lock, &lockstate);
3394 	return (-1);
3395     }
3396 
3397     error = 0;
3398     switch (request) {
3399     case RTLD_DI_LINKMAP:
3400 	*((struct link_map const **)p) = &obj->linkmap;
3401 	break;
3402     case RTLD_DI_ORIGIN:
3403 	error = rtld_dirname(obj->path, p);
3404 	break;
3405 
3406     case RTLD_DI_SERINFOSIZE:
3407     case RTLD_DI_SERINFO:
3408 	error = do_search_info(obj, request, (struct dl_serinfo *)p);
3409 	break;
3410 
3411     default:
3412 	_rtld_error("Invalid request %d passed to dlinfo()", request);
3413 	error = -1;
3414     }
3415 
3416     lock_release(rtld_bind_lock, &lockstate);
3417 
3418     return (error);
3419 }
3420 
3421 static void
3422 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
3423 {
3424 
3425 	phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
3426 	phdr_info->dlpi_name = obj->path;
3427 	phdr_info->dlpi_phdr = obj->phdr;
3428 	phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
3429 	phdr_info->dlpi_tls_modid = obj->tlsindex;
3430 	phdr_info->dlpi_tls_data = obj->tlsinit;
3431 	phdr_info->dlpi_adds = obj_loads;
3432 	phdr_info->dlpi_subs = obj_loads - obj_count;
3433 }
3434 
3435 int
3436 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
3437 {
3438     struct dl_phdr_info phdr_info;
3439     const Obj_Entry *obj;
3440     RtldLockState bind_lockstate, phdr_lockstate;
3441     int error;
3442 
3443     wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
3444     rlock_acquire(rtld_bind_lock, &bind_lockstate);
3445 
3446     error = 0;
3447 
3448     for (obj = obj_list;  obj != NULL;  obj = obj->next) {
3449 	rtld_fill_dl_phdr_info(obj, &phdr_info);
3450 	if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0)
3451 		break;
3452 
3453     }
3454     if (error == 0) {
3455 	rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info);
3456 	error = callback(&phdr_info, sizeof(phdr_info), param);
3457     }
3458 
3459     lock_release(rtld_bind_lock, &bind_lockstate);
3460     lock_release(rtld_phdr_lock, &phdr_lockstate);
3461 
3462     return (error);
3463 }
3464 
3465 static void *
3466 fill_search_info(const char *dir, size_t dirlen, void *param)
3467 {
3468     struct fill_search_info_args *arg;
3469 
3470     arg = param;
3471 
3472     if (arg->request == RTLD_DI_SERINFOSIZE) {
3473 	arg->serinfo->dls_cnt ++;
3474 	arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1;
3475     } else {
3476 	struct dl_serpath *s_entry;
3477 
3478 	s_entry = arg->serpath;
3479 	s_entry->dls_name  = arg->strspace;
3480 	s_entry->dls_flags = arg->flags;
3481 
3482 	strncpy(arg->strspace, dir, dirlen);
3483 	arg->strspace[dirlen] = '\0';
3484 
3485 	arg->strspace += dirlen + 1;
3486 	arg->serpath++;
3487     }
3488 
3489     return (NULL);
3490 }
3491 
3492 static int
3493 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
3494 {
3495     struct dl_serinfo _info;
3496     struct fill_search_info_args args;
3497 
3498     args.request = RTLD_DI_SERINFOSIZE;
3499     args.serinfo = &_info;
3500 
3501     _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
3502     _info.dls_cnt  = 0;
3503 
3504     path_enumerate(obj->rpath, fill_search_info, &args);
3505     path_enumerate(ld_library_path, fill_search_info, &args);
3506     path_enumerate(obj->runpath, fill_search_info, &args);
3507     path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args);
3508     if (!obj->z_nodeflib)
3509       path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
3510 
3511 
3512     if (request == RTLD_DI_SERINFOSIZE) {
3513 	info->dls_size = _info.dls_size;
3514 	info->dls_cnt = _info.dls_cnt;
3515 	return (0);
3516     }
3517 
3518     if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
3519 	_rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
3520 	return (-1);
3521     }
3522 
3523     args.request  = RTLD_DI_SERINFO;
3524     args.serinfo  = info;
3525     args.serpath  = &info->dls_serpath[0];
3526     args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
3527 
3528     args.flags = LA_SER_RUNPATH;
3529     if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
3530 	return (-1);
3531 
3532     args.flags = LA_SER_LIBPATH;
3533     if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
3534 	return (-1);
3535 
3536     args.flags = LA_SER_RUNPATH;
3537     if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL)
3538 	return (-1);
3539 
3540     args.flags = LA_SER_CONFIG;
3541     if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args)
3542       != NULL)
3543 	return (-1);
3544 
3545     args.flags = LA_SER_DEFAULT;
3546     if (!obj->z_nodeflib &&
3547       path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
3548 	return (-1);
3549     return (0);
3550 }
3551 
3552 static int
3553 rtld_dirname(const char *path, char *bname)
3554 {
3555     const char *endp;
3556 
3557     /* Empty or NULL string gets treated as "." */
3558     if (path == NULL || *path == '\0') {
3559 	bname[0] = '.';
3560 	bname[1] = '\0';
3561 	return (0);
3562     }
3563 
3564     /* Strip trailing slashes */
3565     endp = path + strlen(path) - 1;
3566     while (endp > path && *endp == '/')
3567 	endp--;
3568 
3569     /* Find the start of the dir */
3570     while (endp > path && *endp != '/')
3571 	endp--;
3572 
3573     /* Either the dir is "/" or there are no slashes */
3574     if (endp == path) {
3575 	bname[0] = *endp == '/' ? '/' : '.';
3576 	bname[1] = '\0';
3577 	return (0);
3578     } else {
3579 	do {
3580 	    endp--;
3581 	} while (endp > path && *endp == '/');
3582     }
3583 
3584     if (endp - path + 2 > PATH_MAX)
3585     {
3586 	_rtld_error("Filename is too long: %s", path);
3587 	return(-1);
3588     }
3589 
3590     strncpy(bname, path, endp - path + 1);
3591     bname[endp - path + 1] = '\0';
3592     return (0);
3593 }
3594 
3595 static int
3596 rtld_dirname_abs(const char *path, char *base)
3597 {
3598 	char *last;
3599 
3600 	if (realpath(path, base) == NULL)
3601 		return (-1);
3602 	dbg("%s -> %s", path, base);
3603 	last = strrchr(base, '/');
3604 	if (last == NULL)
3605 		return (-1);
3606 	if (last != base)
3607 		*last = '\0';
3608 	return (0);
3609 }
3610 
3611 static void
3612 linkmap_add(Obj_Entry *obj)
3613 {
3614     struct link_map *l = &obj->linkmap;
3615     struct link_map *prev;
3616 
3617     obj->linkmap.l_name = obj->path;
3618     obj->linkmap.l_addr = obj->mapbase;
3619     obj->linkmap.l_ld = obj->dynamic;
3620 #ifdef __mips__
3621     /* GDB needs load offset on MIPS to use the symbols */
3622     obj->linkmap.l_offs = obj->relocbase;
3623 #endif
3624 
3625     if (r_debug.r_map == NULL) {
3626 	r_debug.r_map = l;
3627 	return;
3628     }
3629 
3630     /*
3631      * Scan to the end of the list, but not past the entry for the
3632      * dynamic linker, which we want to keep at the very end.
3633      */
3634     for (prev = r_debug.r_map;
3635       prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
3636       prev = prev->l_next)
3637 	;
3638 
3639     /* Link in the new entry. */
3640     l->l_prev = prev;
3641     l->l_next = prev->l_next;
3642     if (l->l_next != NULL)
3643 	l->l_next->l_prev = l;
3644     prev->l_next = l;
3645 }
3646 
3647 static void
3648 linkmap_delete(Obj_Entry *obj)
3649 {
3650     struct link_map *l = &obj->linkmap;
3651 
3652     if (l->l_prev == NULL) {
3653 	if ((r_debug.r_map = l->l_next) != NULL)
3654 	    l->l_next->l_prev = NULL;
3655 	return;
3656     }
3657 
3658     if ((l->l_prev->l_next = l->l_next) != NULL)
3659 	l->l_next->l_prev = l->l_prev;
3660 }
3661 
3662 /*
3663  * Function for the debugger to set a breakpoint on to gain control.
3664  *
3665  * The two parameters allow the debugger to easily find and determine
3666  * what the runtime loader is doing and to whom it is doing it.
3667  *
3668  * When the loadhook trap is hit (r_debug_state, set at program
3669  * initialization), the arguments can be found on the stack:
3670  *
3671  *  +8   struct link_map *m
3672  *  +4   struct r_debug  *rd
3673  *  +0   RetAddr
3674  */
3675 void
3676 r_debug_state(struct r_debug* rd, struct link_map *m)
3677 {
3678     /*
3679      * The following is a hack to force the compiler to emit calls to
3680      * this function, even when optimizing.  If the function is empty,
3681      * the compiler is not obliged to emit any code for calls to it,
3682      * even when marked __noinline.  However, gdb depends on those
3683      * calls being made.
3684      */
3685     __compiler_membar();
3686 }
3687 
3688 /*
3689  * A function called after init routines have completed. This can be used to
3690  * break before a program's entry routine is called, and can be used when
3691  * main is not available in the symbol table.
3692  */
3693 void
3694 _r_debug_postinit(struct link_map *m)
3695 {
3696 
3697 	/* See r_debug_state(). */
3698 	__compiler_membar();
3699 }
3700 
3701 /*
3702  * Get address of the pointer variable in the main program.
3703  * Prefer non-weak symbol over the weak one.
3704  */
3705 static const void **
3706 get_program_var_addr(const char *name, RtldLockState *lockstate)
3707 {
3708     SymLook req;
3709     DoneList donelist;
3710 
3711     symlook_init(&req, name);
3712     req.lockstate = lockstate;
3713     donelist_init(&donelist);
3714     if (symlook_global(&req, &donelist) != 0)
3715 	return (NULL);
3716     if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC)
3717 	return ((const void **)make_function_pointer(req.sym_out,
3718 	  req.defobj_out));
3719     else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC)
3720 	return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out));
3721     else
3722 	return ((const void **)(req.defobj_out->relocbase +
3723 	  req.sym_out->st_value));
3724 }
3725 
3726 /*
3727  * Set a pointer variable in the main program to the given value.  This
3728  * is used to set key variables such as "environ" before any of the
3729  * init functions are called.
3730  */
3731 static void
3732 set_program_var(const char *name, const void *value)
3733 {
3734     const void **addr;
3735 
3736     if ((addr = get_program_var_addr(name, NULL)) != NULL) {
3737 	dbg("\"%s\": *%p <-- %p", name, addr, value);
3738 	*addr = value;
3739     }
3740 }
3741 
3742 /*
3743  * Search the global objects, including dependencies and main object,
3744  * for the given symbol.
3745  */
3746 static int
3747 symlook_global(SymLook *req, DoneList *donelist)
3748 {
3749     SymLook req1;
3750     const Objlist_Entry *elm;
3751     int res;
3752 
3753     symlook_init_from_req(&req1, req);
3754 
3755     /* Search all objects loaded at program start up. */
3756     if (req->defobj_out == NULL ||
3757       ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
3758 	res = symlook_list(&req1, &list_main, donelist);
3759 	if (res == 0 && (req->defobj_out == NULL ||
3760 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3761 	    req->sym_out = req1.sym_out;
3762 	    req->defobj_out = req1.defobj_out;
3763 	    assert(req->defobj_out != NULL);
3764 	}
3765     }
3766 
3767     /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
3768     STAILQ_FOREACH(elm, &list_global, link) {
3769 	if (req->defobj_out != NULL &&
3770 	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
3771 	    break;
3772 	res = symlook_list(&req1, &elm->obj->dagmembers, donelist);
3773 	if (res == 0 && (req->defobj_out == NULL ||
3774 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3775 	    req->sym_out = req1.sym_out;
3776 	    req->defobj_out = req1.defobj_out;
3777 	    assert(req->defobj_out != NULL);
3778 	}
3779     }
3780 
3781     return (req->sym_out != NULL ? 0 : ESRCH);
3782 }
3783 
3784 /*
3785  * Given a symbol name in a referencing object, find the corresponding
3786  * definition of the symbol.  Returns a pointer to the symbol, or NULL if
3787  * no definition was found.  Returns a pointer to the Obj_Entry of the
3788  * defining object via the reference parameter DEFOBJ_OUT.
3789  */
3790 static int
3791 symlook_default(SymLook *req, const Obj_Entry *refobj)
3792 {
3793     DoneList donelist;
3794     const Objlist_Entry *elm;
3795     SymLook req1;
3796     int res;
3797 
3798     donelist_init(&donelist);
3799     symlook_init_from_req(&req1, req);
3800 
3801     /* Look first in the referencing object if linked symbolically. */
3802     if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
3803 	res = symlook_obj(&req1, refobj);
3804 	if (res == 0) {
3805 	    req->sym_out = req1.sym_out;
3806 	    req->defobj_out = req1.defobj_out;
3807 	    assert(req->defobj_out != NULL);
3808 	}
3809     }
3810 
3811     symlook_global(req, &donelist);
3812 
3813     /* Search all dlopened DAGs containing the referencing object. */
3814     STAILQ_FOREACH(elm, &refobj->dldags, link) {
3815 	if (req->sym_out != NULL &&
3816 	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
3817 	    break;
3818 	res = symlook_list(&req1, &elm->obj->dagmembers, &donelist);
3819 	if (res == 0 && (req->sym_out == NULL ||
3820 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3821 	    req->sym_out = req1.sym_out;
3822 	    req->defobj_out = req1.defobj_out;
3823 	    assert(req->defobj_out != NULL);
3824 	}
3825     }
3826 
3827     /*
3828      * Search the dynamic linker itself, and possibly resolve the
3829      * symbol from there.  This is how the application links to
3830      * dynamic linker services such as dlopen.
3831      */
3832     if (req->sym_out == NULL ||
3833       ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
3834 	res = symlook_obj(&req1, &obj_rtld);
3835 	if (res == 0) {
3836 	    req->sym_out = req1.sym_out;
3837 	    req->defobj_out = req1.defobj_out;
3838 	    assert(req->defobj_out != NULL);
3839 	}
3840     }
3841 
3842     return (req->sym_out != NULL ? 0 : ESRCH);
3843 }
3844 
3845 static int
3846 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp)
3847 {
3848     const Elf_Sym *def;
3849     const Obj_Entry *defobj;
3850     const Objlist_Entry *elm;
3851     SymLook req1;
3852     int res;
3853 
3854     def = NULL;
3855     defobj = NULL;
3856     STAILQ_FOREACH(elm, objlist, link) {
3857 	if (donelist_check(dlp, elm->obj))
3858 	    continue;
3859 	symlook_init_from_req(&req1, req);
3860 	if ((res = symlook_obj(&req1, elm->obj)) == 0) {
3861 	    if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
3862 		def = req1.sym_out;
3863 		defobj = req1.defobj_out;
3864 		if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3865 		    break;
3866 	    }
3867 	}
3868     }
3869     if (def != NULL) {
3870 	req->sym_out = def;
3871 	req->defobj_out = defobj;
3872 	return (0);
3873     }
3874     return (ESRCH);
3875 }
3876 
3877 /*
3878  * Search the chain of DAGS cointed to by the given Needed_Entry
3879  * for a symbol of the given name.  Each DAG is scanned completely
3880  * before advancing to the next one.  Returns a pointer to the symbol,
3881  * or NULL if no definition was found.
3882  */
3883 static int
3884 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp)
3885 {
3886     const Elf_Sym *def;
3887     const Needed_Entry *n;
3888     const Obj_Entry *defobj;
3889     SymLook req1;
3890     int res;
3891 
3892     def = NULL;
3893     defobj = NULL;
3894     symlook_init_from_req(&req1, req);
3895     for (n = needed; n != NULL; n = n->next) {
3896 	if (n->obj == NULL ||
3897 	    (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0)
3898 	    continue;
3899 	if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
3900 	    def = req1.sym_out;
3901 	    defobj = req1.defobj_out;
3902 	    if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3903 		break;
3904 	}
3905     }
3906     if (def != NULL) {
3907 	req->sym_out = def;
3908 	req->defobj_out = defobj;
3909 	return (0);
3910     }
3911     return (ESRCH);
3912 }
3913 
3914 /*
3915  * Search the symbol table of a single shared object for a symbol of
3916  * the given name and version, if requested.  Returns a pointer to the
3917  * symbol, or NULL if no definition was found.  If the object is
3918  * filter, return filtered symbol from filtee.
3919  *
3920  * The symbol's hash value is passed in for efficiency reasons; that
3921  * eliminates many recomputations of the hash value.
3922  */
3923 int
3924 symlook_obj(SymLook *req, const Obj_Entry *obj)
3925 {
3926     DoneList donelist;
3927     SymLook req1;
3928     int flags, res, mres;
3929 
3930     /*
3931      * If there is at least one valid hash at this point, we prefer to
3932      * use the faster GNU version if available.
3933      */
3934     if (obj->valid_hash_gnu)
3935 	mres = symlook_obj1_gnu(req, obj);
3936     else if (obj->valid_hash_sysv)
3937 	mres = symlook_obj1_sysv(req, obj);
3938     else
3939 	return (EINVAL);
3940 
3941     if (mres == 0) {
3942 	if (obj->needed_filtees != NULL) {
3943 	    flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
3944 	    load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
3945 	    donelist_init(&donelist);
3946 	    symlook_init_from_req(&req1, req);
3947 	    res = symlook_needed(&req1, obj->needed_filtees, &donelist);
3948 	    if (res == 0) {
3949 		req->sym_out = req1.sym_out;
3950 		req->defobj_out = req1.defobj_out;
3951 	    }
3952 	    return (res);
3953 	}
3954 	if (obj->needed_aux_filtees != NULL) {
3955 	    flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
3956 	    load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
3957 	    donelist_init(&donelist);
3958 	    symlook_init_from_req(&req1, req);
3959 	    res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist);
3960 	    if (res == 0) {
3961 		req->sym_out = req1.sym_out;
3962 		req->defobj_out = req1.defobj_out;
3963 		return (res);
3964 	    }
3965 	}
3966     }
3967     return (mres);
3968 }
3969 
3970 /* Symbol match routine common to both hash functions */
3971 static bool
3972 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result,
3973     const unsigned long symnum)
3974 {
3975 	Elf_Versym verndx;
3976 	const Elf_Sym *symp;
3977 	const char *strp;
3978 
3979 	symp = obj->symtab + symnum;
3980 	strp = obj->strtab + symp->st_name;
3981 
3982 	switch (ELF_ST_TYPE(symp->st_info)) {
3983 	case STT_FUNC:
3984 	case STT_NOTYPE:
3985 	case STT_OBJECT:
3986 	case STT_COMMON:
3987 	case STT_GNU_IFUNC:
3988 		if (symp->st_value == 0)
3989 			return (false);
3990 		/* fallthrough */
3991 	case STT_TLS:
3992 		if (symp->st_shndx != SHN_UNDEF)
3993 			break;
3994 #ifndef __mips__
3995 		else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
3996 		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
3997 			break;
3998 		/* fallthrough */
3999 #endif
4000 	default:
4001 		return (false);
4002 	}
4003 	if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0)
4004 		return (false);
4005 
4006 	if (req->ventry == NULL) {
4007 		if (obj->versyms != NULL) {
4008 			verndx = VER_NDX(obj->versyms[symnum]);
4009 			if (verndx > obj->vernum) {
4010 				_rtld_error(
4011 				    "%s: symbol %s references wrong version %d",
4012 				    obj->path, obj->strtab + symnum, verndx);
4013 				return (false);
4014 			}
4015 			/*
4016 			 * If we are not called from dlsym (i.e. this
4017 			 * is a normal relocation from unversioned
4018 			 * binary), accept the symbol immediately if
4019 			 * it happens to have first version after this
4020 			 * shared object became versioned.  Otherwise,
4021 			 * if symbol is versioned and not hidden,
4022 			 * remember it. If it is the only symbol with
4023 			 * this name exported by the shared object, it
4024 			 * will be returned as a match by the calling
4025 			 * function. If symbol is global (verndx < 2)
4026 			 * accept it unconditionally.
4027 			 */
4028 			if ((req->flags & SYMLOOK_DLSYM) == 0 &&
4029 			    verndx == VER_NDX_GIVEN) {
4030 				result->sym_out = symp;
4031 				return (true);
4032 			}
4033 			else if (verndx >= VER_NDX_GIVEN) {
4034 				if ((obj->versyms[symnum] & VER_NDX_HIDDEN)
4035 				    == 0) {
4036 					if (result->vsymp == NULL)
4037 						result->vsymp = symp;
4038 					result->vcount++;
4039 				}
4040 				return (false);
4041 			}
4042 		}
4043 		result->sym_out = symp;
4044 		return (true);
4045 	}
4046 	if (obj->versyms == NULL) {
4047 		if (object_match_name(obj, req->ventry->name)) {
4048 			_rtld_error("%s: object %s should provide version %s "
4049 			    "for symbol %s", obj_rtld.path, obj->path,
4050 			    req->ventry->name, obj->strtab + symnum);
4051 			return (false);
4052 		}
4053 	} else {
4054 		verndx = VER_NDX(obj->versyms[symnum]);
4055 		if (verndx > obj->vernum) {
4056 			_rtld_error("%s: symbol %s references wrong version %d",
4057 			    obj->path, obj->strtab + symnum, verndx);
4058 			return (false);
4059 		}
4060 		if (obj->vertab[verndx].hash != req->ventry->hash ||
4061 		    strcmp(obj->vertab[verndx].name, req->ventry->name)) {
4062 			/*
4063 			 * Version does not match. Look if this is a
4064 			 * global symbol and if it is not hidden. If
4065 			 * global symbol (verndx < 2) is available,
4066 			 * use it. Do not return symbol if we are
4067 			 * called by dlvsym, because dlvsym looks for
4068 			 * a specific version and default one is not
4069 			 * what dlvsym wants.
4070 			 */
4071 			if ((req->flags & SYMLOOK_DLSYM) ||
4072 			    (verndx >= VER_NDX_GIVEN) ||
4073 			    (obj->versyms[symnum] & VER_NDX_HIDDEN))
4074 				return (false);
4075 		}
4076 	}
4077 	result->sym_out = symp;
4078 	return (true);
4079 }
4080 
4081 /*
4082  * Search for symbol using SysV hash function.
4083  * obj->buckets is known not to be NULL at this point; the test for this was
4084  * performed with the obj->valid_hash_sysv assignment.
4085  */
4086 static int
4087 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj)
4088 {
4089 	unsigned long symnum;
4090 	Sym_Match_Result matchres;
4091 
4092 	matchres.sym_out = NULL;
4093 	matchres.vsymp = NULL;
4094 	matchres.vcount = 0;
4095 
4096 	for (symnum = obj->buckets[req->hash % obj->nbuckets];
4097 	    symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
4098 		if (symnum >= obj->nchains)
4099 			return (ESRCH);	/* Bad object */
4100 
4101 		if (matched_symbol(req, obj, &matchres, symnum)) {
4102 			req->sym_out = matchres.sym_out;
4103 			req->defobj_out = obj;
4104 			return (0);
4105 		}
4106 	}
4107 	if (matchres.vcount == 1) {
4108 		req->sym_out = matchres.vsymp;
4109 		req->defobj_out = obj;
4110 		return (0);
4111 	}
4112 	return (ESRCH);
4113 }
4114 
4115 /* Search for symbol using GNU hash function */
4116 static int
4117 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj)
4118 {
4119 	Elf_Addr bloom_word;
4120 	const Elf32_Word *hashval;
4121 	Elf32_Word bucket;
4122 	Sym_Match_Result matchres;
4123 	unsigned int h1, h2;
4124 	unsigned long symnum;
4125 
4126 	matchres.sym_out = NULL;
4127 	matchres.vsymp = NULL;
4128 	matchres.vcount = 0;
4129 
4130 	/* Pick right bitmask word from Bloom filter array */
4131 	bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) &
4132 	    obj->maskwords_bm_gnu];
4133 
4134 	/* Calculate modulus word size of gnu hash and its derivative */
4135 	h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1);
4136 	h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1));
4137 
4138 	/* Filter out the "definitely not in set" queries */
4139 	if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0)
4140 		return (ESRCH);
4141 
4142 	/* Locate hash chain and corresponding value element*/
4143 	bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu];
4144 	if (bucket == 0)
4145 		return (ESRCH);
4146 	hashval = &obj->chain_zero_gnu[bucket];
4147 	do {
4148 		if (((*hashval ^ req->hash_gnu) >> 1) == 0) {
4149 			symnum = hashval - obj->chain_zero_gnu;
4150 			if (matched_symbol(req, obj, &matchres, symnum)) {
4151 				req->sym_out = matchres.sym_out;
4152 				req->defobj_out = obj;
4153 				return (0);
4154 			}
4155 		}
4156 	} while ((*hashval++ & 1) == 0);
4157 	if (matchres.vcount == 1) {
4158 		req->sym_out = matchres.vsymp;
4159 		req->defobj_out = obj;
4160 		return (0);
4161 	}
4162 	return (ESRCH);
4163 }
4164 
4165 static void
4166 trace_loaded_objects(Obj_Entry *obj)
4167 {
4168     char	*fmt1, *fmt2, *fmt, *main_local, *list_containers;
4169     int		c;
4170 
4171     if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
4172 	main_local = "";
4173 
4174     if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL)
4175 	fmt1 = "\t%o => %p (%x)\n";
4176 
4177     if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL)
4178 	fmt2 = "\t%o (%x)\n";
4179 
4180     list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL");
4181 
4182     for (; obj; obj = obj->next) {
4183 	Needed_Entry		*needed;
4184 	char			*name, *path;
4185 	bool			is_lib;
4186 
4187 	if (list_containers && obj->needed != NULL)
4188 	    rtld_printf("%s:\n", obj->path);
4189 	for (needed = obj->needed; needed; needed = needed->next) {
4190 	    if (needed->obj != NULL) {
4191 		if (needed->obj->traced && !list_containers)
4192 		    continue;
4193 		needed->obj->traced = true;
4194 		path = needed->obj->path;
4195 	    } else
4196 		path = "not found";
4197 
4198 	    name = (char *)obj->strtab + needed->name;
4199 	    is_lib = strncmp(name, "lib", 3) == 0;	/* XXX - bogus */
4200 
4201 	    fmt = is_lib ? fmt1 : fmt2;
4202 	    while ((c = *fmt++) != '\0') {
4203 		switch (c) {
4204 		default:
4205 		    rtld_putchar(c);
4206 		    continue;
4207 		case '\\':
4208 		    switch (c = *fmt) {
4209 		    case '\0':
4210 			continue;
4211 		    case 'n':
4212 			rtld_putchar('\n');
4213 			break;
4214 		    case 't':
4215 			rtld_putchar('\t');
4216 			break;
4217 		    }
4218 		    break;
4219 		case '%':
4220 		    switch (c = *fmt) {
4221 		    case '\0':
4222 			continue;
4223 		    case '%':
4224 		    default:
4225 			rtld_putchar(c);
4226 			break;
4227 		    case 'A':
4228 			rtld_putstr(main_local);
4229 			break;
4230 		    case 'a':
4231 			rtld_putstr(obj_main->path);
4232 			break;
4233 		    case 'o':
4234 			rtld_putstr(name);
4235 			break;
4236 #if 0
4237 		    case 'm':
4238 			rtld_printf("%d", sodp->sod_major);
4239 			break;
4240 		    case 'n':
4241 			rtld_printf("%d", sodp->sod_minor);
4242 			break;
4243 #endif
4244 		    case 'p':
4245 			rtld_putstr(path);
4246 			break;
4247 		    case 'x':
4248 			rtld_printf("%p", needed->obj ? needed->obj->mapbase :
4249 			  0);
4250 			break;
4251 		    }
4252 		    break;
4253 		}
4254 		++fmt;
4255 	    }
4256 	}
4257     }
4258 }
4259 
4260 /*
4261  * Unload a dlopened object and its dependencies from memory and from
4262  * our data structures.  It is assumed that the DAG rooted in the
4263  * object has already been unreferenced, and that the object has a
4264  * reference count of 0.
4265  */
4266 static void
4267 unload_object(Obj_Entry *root)
4268 {
4269     Obj_Entry *obj;
4270     Obj_Entry **linkp;
4271 
4272     assert(root->refcount == 0);
4273 
4274     /*
4275      * Pass over the DAG removing unreferenced objects from
4276      * appropriate lists.
4277      */
4278     unlink_object(root);
4279 
4280     /* Unmap all objects that are no longer referenced. */
4281     linkp = &obj_list->next;
4282     while ((obj = *linkp) != NULL) {
4283 	if (obj->refcount == 0) {
4284 	    LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
4285 		obj->path);
4286 	    dbg("unloading \"%s\"", obj->path);
4287 	    unload_filtees(root);
4288 	    munmap(obj->mapbase, obj->mapsize);
4289 	    linkmap_delete(obj);
4290 	    *linkp = obj->next;
4291 	    obj_count--;
4292 	    obj_free(obj);
4293 	} else
4294 	    linkp = &obj->next;
4295     }
4296     obj_tail = linkp;
4297 }
4298 
4299 static void
4300 unlink_object(Obj_Entry *root)
4301 {
4302     Objlist_Entry *elm;
4303 
4304     if (root->refcount == 0) {
4305 	/* Remove the object from the RTLD_GLOBAL list. */
4306 	objlist_remove(&list_global, root);
4307 
4308     	/* Remove the object from all objects' DAG lists. */
4309     	STAILQ_FOREACH(elm, &root->dagmembers, link) {
4310 	    objlist_remove(&elm->obj->dldags, root);
4311 	    if (elm->obj != root)
4312 		unlink_object(elm->obj);
4313 	}
4314     }
4315 }
4316 
4317 static void
4318 ref_dag(Obj_Entry *root)
4319 {
4320     Objlist_Entry *elm;
4321 
4322     assert(root->dag_inited);
4323     STAILQ_FOREACH(elm, &root->dagmembers, link)
4324 	elm->obj->refcount++;
4325 }
4326 
4327 static void
4328 unref_dag(Obj_Entry *root)
4329 {
4330     Objlist_Entry *elm;
4331 
4332     assert(root->dag_inited);
4333     STAILQ_FOREACH(elm, &root->dagmembers, link)
4334 	elm->obj->refcount--;
4335 }
4336 
4337 /*
4338  * Common code for MD __tls_get_addr().
4339  */
4340 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline;
4341 static void *
4342 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset)
4343 {
4344     Elf_Addr *newdtv, *dtv;
4345     RtldLockState lockstate;
4346     int to_copy;
4347 
4348     dtv = *dtvp;
4349     /* Check dtv generation in case new modules have arrived */
4350     if (dtv[0] != tls_dtv_generation) {
4351 	wlock_acquire(rtld_bind_lock, &lockstate);
4352 	newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4353 	to_copy = dtv[1];
4354 	if (to_copy > tls_max_index)
4355 	    to_copy = tls_max_index;
4356 	memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
4357 	newdtv[0] = tls_dtv_generation;
4358 	newdtv[1] = tls_max_index;
4359 	free(dtv);
4360 	lock_release(rtld_bind_lock, &lockstate);
4361 	dtv = *dtvp = newdtv;
4362     }
4363 
4364     /* Dynamically allocate module TLS if necessary */
4365     if (dtv[index + 1] == 0) {
4366 	/* Signal safe, wlock will block out signals. */
4367 	wlock_acquire(rtld_bind_lock, &lockstate);
4368 	if (!dtv[index + 1])
4369 	    dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
4370 	lock_release(rtld_bind_lock, &lockstate);
4371     }
4372     return ((void *)(dtv[index + 1] + offset));
4373 }
4374 
4375 void *
4376 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset)
4377 {
4378 	Elf_Addr *dtv;
4379 
4380 	dtv = *dtvp;
4381 	/* Check dtv generation in case new modules have arrived */
4382 	if (__predict_true(dtv[0] == tls_dtv_generation &&
4383 	    dtv[index + 1] != 0))
4384 		return ((void *)(dtv[index + 1] + offset));
4385 	return (tls_get_addr_slow(dtvp, index, offset));
4386 }
4387 
4388 #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \
4389     defined(__powerpc__)
4390 
4391 /*
4392  * Allocate Static TLS using the Variant I method.
4393  */
4394 void *
4395 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
4396 {
4397     Obj_Entry *obj;
4398     char *tcb;
4399     Elf_Addr **tls;
4400     Elf_Addr *dtv;
4401     Elf_Addr addr;
4402     int i;
4403 
4404     if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
4405 	return (oldtcb);
4406 
4407     assert(tcbsize >= TLS_TCB_SIZE);
4408     tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize);
4409     tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
4410 
4411     if (oldtcb != NULL) {
4412 	memcpy(tls, oldtcb, tls_static_space);
4413 	free(oldtcb);
4414 
4415 	/* Adjust the DTV. */
4416 	dtv = tls[0];
4417 	for (i = 0; i < dtv[1]; i++) {
4418 	    if (dtv[i+2] >= (Elf_Addr)oldtcb &&
4419 		dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
4420 		dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls;
4421 	    }
4422 	}
4423     } else {
4424 	dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4425 	tls[0] = dtv;
4426 	dtv[0] = tls_dtv_generation;
4427 	dtv[1] = tls_max_index;
4428 
4429 	for (obj = objs; obj; obj = obj->next) {
4430 	    if (obj->tlsoffset > 0) {
4431 		addr = (Elf_Addr)tls + obj->tlsoffset;
4432 		if (obj->tlsinitsize > 0)
4433 		    memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
4434 		if (obj->tlssize > obj->tlsinitsize)
4435 		    memset((void*) (addr + obj->tlsinitsize), 0,
4436 			   obj->tlssize - obj->tlsinitsize);
4437 		dtv[obj->tlsindex + 1] = addr;
4438 	    }
4439 	}
4440     }
4441 
4442     return (tcb);
4443 }
4444 
4445 void
4446 free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
4447 {
4448     Elf_Addr *dtv;
4449     Elf_Addr tlsstart, tlsend;
4450     int dtvsize, i;
4451 
4452     assert(tcbsize >= TLS_TCB_SIZE);
4453 
4454     tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE;
4455     tlsend = tlsstart + tls_static_space;
4456 
4457     dtv = *(Elf_Addr **)tlsstart;
4458     dtvsize = dtv[1];
4459     for (i = 0; i < dtvsize; i++) {
4460 	if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
4461 	    free((void*)dtv[i+2]);
4462 	}
4463     }
4464     free(dtv);
4465     free(tcb);
4466 }
4467 
4468 #endif
4469 
4470 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__)
4471 
4472 /*
4473  * Allocate Static TLS using the Variant II method.
4474  */
4475 void *
4476 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
4477 {
4478     Obj_Entry *obj;
4479     size_t size, ralign;
4480     char *tls;
4481     Elf_Addr *dtv, *olddtv;
4482     Elf_Addr segbase, oldsegbase, addr;
4483     int i;
4484 
4485     ralign = tcbalign;
4486     if (tls_static_max_align > ralign)
4487 	    ralign = tls_static_max_align;
4488     size = round(tls_static_space, ralign) + round(tcbsize, ralign);
4489 
4490     assert(tcbsize >= 2*sizeof(Elf_Addr));
4491     tls = malloc_aligned(size, ralign);
4492     dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4493 
4494     segbase = (Elf_Addr)(tls + round(tls_static_space, ralign));
4495     ((Elf_Addr*)segbase)[0] = segbase;
4496     ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
4497 
4498     dtv[0] = tls_dtv_generation;
4499     dtv[1] = tls_max_index;
4500 
4501     if (oldtls) {
4502 	/*
4503 	 * Copy the static TLS block over whole.
4504 	 */
4505 	oldsegbase = (Elf_Addr) oldtls;
4506 	memcpy((void *)(segbase - tls_static_space),
4507 	       (const void *)(oldsegbase - tls_static_space),
4508 	       tls_static_space);
4509 
4510 	/*
4511 	 * If any dynamic TLS blocks have been created tls_get_addr(),
4512 	 * move them over.
4513 	 */
4514 	olddtv = ((Elf_Addr**)oldsegbase)[1];
4515 	for (i = 0; i < olddtv[1]; i++) {
4516 	    if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) {
4517 		dtv[i+2] = olddtv[i+2];
4518 		olddtv[i+2] = 0;
4519 	    }
4520 	}
4521 
4522 	/*
4523 	 * We assume that this block was the one we created with
4524 	 * allocate_initial_tls().
4525 	 */
4526 	free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
4527     } else {
4528 	for (obj = objs; obj; obj = obj->next) {
4529 	    if (obj->tlsoffset) {
4530 		addr = segbase - obj->tlsoffset;
4531 		memset((void*) (addr + obj->tlsinitsize),
4532 		       0, obj->tlssize - obj->tlsinitsize);
4533 		if (obj->tlsinit)
4534 		    memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
4535 		dtv[obj->tlsindex + 1] = addr;
4536 	    }
4537 	}
4538     }
4539 
4540     return (void*) segbase;
4541 }
4542 
4543 void
4544 free_tls(void *tls, size_t tcbsize, size_t tcbalign)
4545 {
4546     Elf_Addr* dtv;
4547     size_t size, ralign;
4548     int dtvsize, i;
4549     Elf_Addr tlsstart, tlsend;
4550 
4551     /*
4552      * Figure out the size of the initial TLS block so that we can
4553      * find stuff which ___tls_get_addr() allocated dynamically.
4554      */
4555     ralign = tcbalign;
4556     if (tls_static_max_align > ralign)
4557 	    ralign = tls_static_max_align;
4558     size = round(tls_static_space, ralign);
4559 
4560     dtv = ((Elf_Addr**)tls)[1];
4561     dtvsize = dtv[1];
4562     tlsend = (Elf_Addr) tls;
4563     tlsstart = tlsend - size;
4564     for (i = 0; i < dtvsize; i++) {
4565 	if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) {
4566 		free_aligned((void *)dtv[i + 2]);
4567 	}
4568     }
4569 
4570     free_aligned((void *)tlsstart);
4571     free((void*) dtv);
4572 }
4573 
4574 #endif
4575 
4576 /*
4577  * Allocate TLS block for module with given index.
4578  */
4579 void *
4580 allocate_module_tls(int index)
4581 {
4582     Obj_Entry* obj;
4583     char* p;
4584 
4585     for (obj = obj_list; obj; obj = obj->next) {
4586 	if (obj->tlsindex == index)
4587 	    break;
4588     }
4589     if (!obj) {
4590 	_rtld_error("Can't find module with TLS index %d", index);
4591 	rtld_die();
4592     }
4593 
4594     p = malloc_aligned(obj->tlssize, obj->tlsalign);
4595     memcpy(p, obj->tlsinit, obj->tlsinitsize);
4596     memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
4597 
4598     return p;
4599 }
4600 
4601 bool
4602 allocate_tls_offset(Obj_Entry *obj)
4603 {
4604     size_t off;
4605 
4606     if (obj->tls_done)
4607 	return true;
4608 
4609     if (obj->tlssize == 0) {
4610 	obj->tls_done = true;
4611 	return true;
4612     }
4613 
4614     if (tls_last_offset == 0)
4615 	off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
4616     else
4617 	off = calculate_tls_offset(tls_last_offset, tls_last_size,
4618 				   obj->tlssize, obj->tlsalign);
4619 
4620     /*
4621      * If we have already fixed the size of the static TLS block, we
4622      * must stay within that size. When allocating the static TLS, we
4623      * leave a small amount of space spare to be used for dynamically
4624      * loading modules which use static TLS.
4625      */
4626     if (tls_static_space != 0) {
4627 	if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
4628 	    return false;
4629     } else if (obj->tlsalign > tls_static_max_align) {
4630 	    tls_static_max_align = obj->tlsalign;
4631     }
4632 
4633     tls_last_offset = obj->tlsoffset = off;
4634     tls_last_size = obj->tlssize;
4635     obj->tls_done = true;
4636 
4637     return true;
4638 }
4639 
4640 void
4641 free_tls_offset(Obj_Entry *obj)
4642 {
4643 
4644     /*
4645      * If we were the last thing to allocate out of the static TLS
4646      * block, we give our space back to the 'allocator'. This is a
4647      * simplistic workaround to allow libGL.so.1 to be loaded and
4648      * unloaded multiple times.
4649      */
4650     if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
4651 	== calculate_tls_end(tls_last_offset, tls_last_size)) {
4652 	tls_last_offset -= obj->tlssize;
4653 	tls_last_size = 0;
4654     }
4655 }
4656 
4657 void *
4658 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
4659 {
4660     void *ret;
4661     RtldLockState lockstate;
4662 
4663     wlock_acquire(rtld_bind_lock, &lockstate);
4664     ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign);
4665     lock_release(rtld_bind_lock, &lockstate);
4666     return (ret);
4667 }
4668 
4669 void
4670 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
4671 {
4672     RtldLockState lockstate;
4673 
4674     wlock_acquire(rtld_bind_lock, &lockstate);
4675     free_tls(tcb, tcbsize, tcbalign);
4676     lock_release(rtld_bind_lock, &lockstate);
4677 }
4678 
4679 static void
4680 object_add_name(Obj_Entry *obj, const char *name)
4681 {
4682     Name_Entry *entry;
4683     size_t len;
4684 
4685     len = strlen(name);
4686     entry = malloc(sizeof(Name_Entry) + len);
4687 
4688     if (entry != NULL) {
4689 	strcpy(entry->name, name);
4690 	STAILQ_INSERT_TAIL(&obj->names, entry, link);
4691     }
4692 }
4693 
4694 static int
4695 object_match_name(const Obj_Entry *obj, const char *name)
4696 {
4697     Name_Entry *entry;
4698 
4699     STAILQ_FOREACH(entry, &obj->names, link) {
4700 	if (strcmp(name, entry->name) == 0)
4701 	    return (1);
4702     }
4703     return (0);
4704 }
4705 
4706 static Obj_Entry *
4707 locate_dependency(const Obj_Entry *obj, const char *name)
4708 {
4709     const Objlist_Entry *entry;
4710     const Needed_Entry *needed;
4711 
4712     STAILQ_FOREACH(entry, &list_main, link) {
4713 	if (object_match_name(entry->obj, name))
4714 	    return entry->obj;
4715     }
4716 
4717     for (needed = obj->needed;  needed != NULL;  needed = needed->next) {
4718 	if (strcmp(obj->strtab + needed->name, name) == 0 ||
4719 	  (needed->obj != NULL && object_match_name(needed->obj, name))) {
4720 	    /*
4721 	     * If there is DT_NEEDED for the name we are looking for,
4722 	     * we are all set.  Note that object might not be found if
4723 	     * dependency was not loaded yet, so the function can
4724 	     * return NULL here.  This is expected and handled
4725 	     * properly by the caller.
4726 	     */
4727 	    return (needed->obj);
4728 	}
4729     }
4730     _rtld_error("%s: Unexpected inconsistency: dependency %s not found",
4731 	obj->path, name);
4732     rtld_die();
4733 }
4734 
4735 static int
4736 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
4737     const Elf_Vernaux *vna)
4738 {
4739     const Elf_Verdef *vd;
4740     const char *vername;
4741 
4742     vername = refobj->strtab + vna->vna_name;
4743     vd = depobj->verdef;
4744     if (vd == NULL) {
4745 	_rtld_error("%s: version %s required by %s not defined",
4746 	    depobj->path, vername, refobj->path);
4747 	return (-1);
4748     }
4749     for (;;) {
4750 	if (vd->vd_version != VER_DEF_CURRENT) {
4751 	    _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
4752 		depobj->path, vd->vd_version);
4753 	    return (-1);
4754 	}
4755 	if (vna->vna_hash == vd->vd_hash) {
4756 	    const Elf_Verdaux *aux = (const Elf_Verdaux *)
4757 		((char *)vd + vd->vd_aux);
4758 	    if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
4759 		return (0);
4760 	}
4761 	if (vd->vd_next == 0)
4762 	    break;
4763 	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4764     }
4765     if (vna->vna_flags & VER_FLG_WEAK)
4766 	return (0);
4767     _rtld_error("%s: version %s required by %s not found",
4768 	depobj->path, vername, refobj->path);
4769     return (-1);
4770 }
4771 
4772 static int
4773 rtld_verify_object_versions(Obj_Entry *obj)
4774 {
4775     const Elf_Verneed *vn;
4776     const Elf_Verdef  *vd;
4777     const Elf_Verdaux *vda;
4778     const Elf_Vernaux *vna;
4779     const Obj_Entry *depobj;
4780     int maxvernum, vernum;
4781 
4782     if (obj->ver_checked)
4783 	return (0);
4784     obj->ver_checked = true;
4785 
4786     maxvernum = 0;
4787     /*
4788      * Walk over defined and required version records and figure out
4789      * max index used by any of them. Do very basic sanity checking
4790      * while there.
4791      */
4792     vn = obj->verneed;
4793     while (vn != NULL) {
4794 	if (vn->vn_version != VER_NEED_CURRENT) {
4795 	    _rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
4796 		obj->path, vn->vn_version);
4797 	    return (-1);
4798 	}
4799 	vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
4800 	for (;;) {
4801 	    vernum = VER_NEED_IDX(vna->vna_other);
4802 	    if (vernum > maxvernum)
4803 		maxvernum = vernum;
4804 	    if (vna->vna_next == 0)
4805 		 break;
4806 	    vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
4807 	}
4808 	if (vn->vn_next == 0)
4809 	    break;
4810 	vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
4811     }
4812 
4813     vd = obj->verdef;
4814     while (vd != NULL) {
4815 	if (vd->vd_version != VER_DEF_CURRENT) {
4816 	    _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
4817 		obj->path, vd->vd_version);
4818 	    return (-1);
4819 	}
4820 	vernum = VER_DEF_IDX(vd->vd_ndx);
4821 	if (vernum > maxvernum)
4822 		maxvernum = vernum;
4823 	if (vd->vd_next == 0)
4824 	    break;
4825 	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4826     }
4827 
4828     if (maxvernum == 0)
4829 	return (0);
4830 
4831     /*
4832      * Store version information in array indexable by version index.
4833      * Verify that object version requirements are satisfied along the
4834      * way.
4835      */
4836     obj->vernum = maxvernum + 1;
4837     obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry));
4838 
4839     vd = obj->verdef;
4840     while (vd != NULL) {
4841 	if ((vd->vd_flags & VER_FLG_BASE) == 0) {
4842 	    vernum = VER_DEF_IDX(vd->vd_ndx);
4843 	    assert(vernum <= maxvernum);
4844 	    vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux);
4845 	    obj->vertab[vernum].hash = vd->vd_hash;
4846 	    obj->vertab[vernum].name = obj->strtab + vda->vda_name;
4847 	    obj->vertab[vernum].file = NULL;
4848 	    obj->vertab[vernum].flags = 0;
4849 	}
4850 	if (vd->vd_next == 0)
4851 	    break;
4852 	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4853     }
4854 
4855     vn = obj->verneed;
4856     while (vn != NULL) {
4857 	depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
4858 	if (depobj == NULL)
4859 	    return (-1);
4860 	vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
4861 	for (;;) {
4862 	    if (check_object_provided_version(obj, depobj, vna))
4863 		return (-1);
4864 	    vernum = VER_NEED_IDX(vna->vna_other);
4865 	    assert(vernum <= maxvernum);
4866 	    obj->vertab[vernum].hash = vna->vna_hash;
4867 	    obj->vertab[vernum].name = obj->strtab + vna->vna_name;
4868 	    obj->vertab[vernum].file = obj->strtab + vn->vn_file;
4869 	    obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ?
4870 		VER_INFO_HIDDEN : 0;
4871 	    if (vna->vna_next == 0)
4872 		 break;
4873 	    vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
4874 	}
4875 	if (vn->vn_next == 0)
4876 	    break;
4877 	vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
4878     }
4879     return 0;
4880 }
4881 
4882 static int
4883 rtld_verify_versions(const Objlist *objlist)
4884 {
4885     Objlist_Entry *entry;
4886     int rc;
4887 
4888     rc = 0;
4889     STAILQ_FOREACH(entry, objlist, link) {
4890 	/*
4891 	 * Skip dummy objects or objects that have their version requirements
4892 	 * already checked.
4893 	 */
4894 	if (entry->obj->strtab == NULL || entry->obj->vertab != NULL)
4895 	    continue;
4896 	if (rtld_verify_object_versions(entry->obj) == -1) {
4897 	    rc = -1;
4898 	    if (ld_tracing == NULL)
4899 		break;
4900 	}
4901     }
4902     if (rc == 0 || ld_tracing != NULL)
4903     	rc = rtld_verify_object_versions(&obj_rtld);
4904     return rc;
4905 }
4906 
4907 const Ver_Entry *
4908 fetch_ventry(const Obj_Entry *obj, unsigned long symnum)
4909 {
4910     Elf_Versym vernum;
4911 
4912     if (obj->vertab) {
4913 	vernum = VER_NDX(obj->versyms[symnum]);
4914 	if (vernum >= obj->vernum) {
4915 	    _rtld_error("%s: symbol %s has wrong verneed value %d",
4916 		obj->path, obj->strtab + symnum, vernum);
4917 	} else if (obj->vertab[vernum].hash != 0) {
4918 	    return &obj->vertab[vernum];
4919 	}
4920     }
4921     return NULL;
4922 }
4923 
4924 int
4925 _rtld_get_stack_prot(void)
4926 {
4927 
4928 	return (stack_prot);
4929 }
4930 
4931 int
4932 _rtld_is_dlopened(void *arg)
4933 {
4934 	Obj_Entry *obj;
4935 	RtldLockState lockstate;
4936 	int res;
4937 
4938 	rlock_acquire(rtld_bind_lock, &lockstate);
4939 	obj = dlcheck(arg);
4940 	if (obj == NULL)
4941 		obj = obj_from_addr(arg);
4942 	if (obj == NULL) {
4943 		_rtld_error("No shared object contains address");
4944 		lock_release(rtld_bind_lock, &lockstate);
4945 		return (-1);
4946 	}
4947 	res = obj->dlopened ? 1 : 0;
4948 	lock_release(rtld_bind_lock, &lockstate);
4949 	return (res);
4950 }
4951 
4952 static void
4953 map_stacks_exec(RtldLockState *lockstate)
4954 {
4955 	void (*thr_map_stacks_exec)(void);
4956 
4957 	if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0)
4958 		return;
4959 	thr_map_stacks_exec = (void (*)(void))(uintptr_t)
4960 	    get_program_var_addr("__pthread_map_stacks_exec", lockstate);
4961 	if (thr_map_stacks_exec != NULL) {
4962 		stack_prot |= PROT_EXEC;
4963 		thr_map_stacks_exec();
4964 	}
4965 }
4966 
4967 void
4968 symlook_init(SymLook *dst, const char *name)
4969 {
4970 
4971 	bzero(dst, sizeof(*dst));
4972 	dst->name = name;
4973 	dst->hash = elf_hash(name);
4974 	dst->hash_gnu = gnu_hash(name);
4975 }
4976 
4977 static void
4978 symlook_init_from_req(SymLook *dst, const SymLook *src)
4979 {
4980 
4981 	dst->name = src->name;
4982 	dst->hash = src->hash;
4983 	dst->hash_gnu = src->hash_gnu;
4984 	dst->ventry = src->ventry;
4985 	dst->flags = src->flags;
4986 	dst->defobj_out = NULL;
4987 	dst->sym_out = NULL;
4988 	dst->lockstate = src->lockstate;
4989 }
4990 
4991 
4992 /*
4993  * Parse a file descriptor number without pulling in more of libc (e.g. atoi).
4994  */
4995 static int
4996 parse_libdir(const char *str)
4997 {
4998 	static const int RADIX = 10;  /* XXXJA: possibly support hex? */
4999 	const char *orig;
5000 	int fd;
5001 	char c;
5002 
5003 	orig = str;
5004 	fd = 0;
5005 	for (c = *str; c != '\0'; c = *++str) {
5006 		if (c < '0' || c > '9')
5007 			return (-1);
5008 
5009 		fd *= RADIX;
5010 		fd += c - '0';
5011 	}
5012 
5013 	/* Make sure we actually parsed something. */
5014 	if (str == orig) {
5015 		_rtld_error("failed to parse directory FD from '%s'", str);
5016 		return (-1);
5017 	}
5018 	return (fd);
5019 }
5020 
5021 /*
5022  * Overrides for libc_pic-provided functions.
5023  */
5024 
5025 int
5026 __getosreldate(void)
5027 {
5028 	size_t len;
5029 	int oid[2];
5030 	int error, osrel;
5031 
5032 	if (osreldate != 0)
5033 		return (osreldate);
5034 
5035 	oid[0] = CTL_KERN;
5036 	oid[1] = KERN_OSRELDATE;
5037 	osrel = 0;
5038 	len = sizeof(osrel);
5039 	error = sysctl(oid, 2, &osrel, &len, NULL, 0);
5040 	if (error == 0 && osrel > 0 && len == sizeof(osrel))
5041 		osreldate = osrel;
5042 	return (osreldate);
5043 }
5044 
5045 void
5046 exit(int status)
5047 {
5048 
5049 	_exit(status);
5050 }
5051 
5052 void (*__cleanup)(void);
5053 int __isthreaded = 0;
5054 int _thread_autoinit_dummy_decl = 1;
5055 
5056 /*
5057  * No unresolved symbols for rtld.
5058  */
5059 void
5060 __pthread_cxa_finalize(struct dl_phdr_info *a)
5061 {
5062 }
5063 
5064 void
5065 __stack_chk_fail(void)
5066 {
5067 
5068 	_rtld_error("stack overflow detected; terminated");
5069 	rtld_die();
5070 }
5071 __weak_reference(__stack_chk_fail, __stack_chk_fail_local);
5072 
5073 void
5074 __chk_fail(void)
5075 {
5076 
5077 	_rtld_error("buffer overflow detected; terminated");
5078 	rtld_die();
5079 }
5080 
5081 const char *
5082 rtld_strerror(int errnum)
5083 {
5084 
5085 	if (errnum < 0 || errnum >= sys_nerr)
5086 		return ("Unknown error");
5087 	return (sys_errlist[errnum]);
5088 }
5089