xref: /freebsd/libexec/rtld-elf/rtld.c (revision acc1a9ef8333c798c210fa94be6af4d5fe2dd794)
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 "paths.h"
60 #include "rtld_tls.h"
61 #include "rtld_printf.h"
62 #include "notes.h"
63 
64 /* Types. */
65 typedef void (*func_ptr_type)();
66 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
67 
68 /*
69  * Function declarations.
70  */
71 static const char *basename(const char *);
72 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
73     const Elf_Dyn **, const Elf_Dyn **);
74 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *,
75     const Elf_Dyn *);
76 static void digest_dynamic(Obj_Entry *, int);
77 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
78 static Obj_Entry *dlcheck(void *);
79 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj,
80     int lo_flags, int mode, RtldLockState *lockstate);
81 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
82 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
83 static bool donelist_check(DoneList *, const Obj_Entry *);
84 static void errmsg_restore(char *);
85 static char *errmsg_save(void);
86 static void *fill_search_info(const char *, size_t, void *);
87 static char *find_library(const char *, const Obj_Entry *, int *);
88 static const char *gethints(bool);
89 static void init_dag(Obj_Entry *);
90 static void init_pagesizes(Elf_Auxinfo **aux_info);
91 static void init_rtld(caddr_t, Elf_Auxinfo **);
92 static void initlist_add_neededs(Needed_Entry *, Objlist *);
93 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *);
94 static void linkmap_add(Obj_Entry *);
95 static void linkmap_delete(Obj_Entry *);
96 static void load_filtees(Obj_Entry *, int flags, RtldLockState *);
97 static void unload_filtees(Obj_Entry *);
98 static int load_needed_objects(Obj_Entry *, int);
99 static int load_preload_objects(void);
100 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int);
101 static void map_stacks_exec(RtldLockState *);
102 static Obj_Entry *obj_from_addr(const void *);
103 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
104 static void objlist_call_init(Objlist *, RtldLockState *);
105 static void objlist_clear(Objlist *);
106 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
107 static void objlist_init(Objlist *);
108 static void objlist_push_head(Objlist *, Obj_Entry *);
109 static void objlist_push_tail(Objlist *, Obj_Entry *);
110 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *);
111 static void objlist_remove(Objlist *, Obj_Entry *);
112 static int parse_libdir(const char *);
113 static void *path_enumerate(const char *, path_enum_proc, void *);
114 static int relocate_object_dag(Obj_Entry *root, bool bind_now,
115     Obj_Entry *rtldobj, int flags, RtldLockState *lockstate);
116 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
117     int flags, RtldLockState *lockstate);
118 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int,
119     RtldLockState *);
120 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now,
121     int flags, RtldLockState *lockstate);
122 static int rtld_dirname(const char *, char *);
123 static int rtld_dirname_abs(const char *, char *);
124 static void *rtld_dlopen(const char *name, int fd, int mode);
125 static void rtld_exit(void);
126 static char *search_library_path(const char *, const char *);
127 static char *search_library_pathfds(const char *, const char *, int *);
128 static const void **get_program_var_addr(const char *, RtldLockState *);
129 static void set_program_var(const char *, const void *);
130 static int symlook_default(SymLook *, const Obj_Entry *refobj);
131 static int symlook_global(SymLook *, DoneList *);
132 static void symlook_init_from_req(SymLook *, const SymLook *);
133 static int symlook_list(SymLook *, const Objlist *, DoneList *);
134 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *);
135 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *);
136 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *);
137 static void trace_loaded_objects(Obj_Entry *);
138 static void unlink_object(Obj_Entry *);
139 static void unload_object(Obj_Entry *);
140 static void unref_dag(Obj_Entry *);
141 static void ref_dag(Obj_Entry *);
142 static char *origin_subst_one(Obj_Entry *, char *, const char *,
143     const char *, bool);
144 static char *origin_subst(Obj_Entry *, char *);
145 static bool obj_resolve_origin(Obj_Entry *obj);
146 static void preinit_main(void);
147 static int  rtld_verify_versions(const Objlist *);
148 static int  rtld_verify_object_versions(Obj_Entry *);
149 static void object_add_name(Obj_Entry *, const char *);
150 static int  object_match_name(const Obj_Entry *, const char *);
151 static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
152 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
153     struct dl_phdr_info *phdr_info);
154 static uint32_t gnu_hash(const char *);
155 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *,
156     const unsigned long);
157 
158 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported;
159 void _r_debug_postinit(struct link_map *) __noinline __exported;
160 
161 int __sys_openat(int, const char *, int, ...);
162 
163 /*
164  * Data declarations.
165  */
166 static char *error_message;	/* Message for dlerror(), or NULL */
167 struct r_debug r_debug __exported;	/* for GDB; */
168 static bool libmap_disable;	/* Disable libmap */
169 static bool ld_loadfltr;	/* Immediate filters processing */
170 static char *libmap_override;	/* Maps to use in addition to libmap.conf */
171 static bool trust;		/* False for setuid and setgid programs */
172 static bool dangerous_ld_env;	/* True if environment variables have been
173 				   used to affect the libraries loaded */
174 static char *ld_bind_now;	/* Environment variable for immediate binding */
175 static char *ld_debug;		/* Environment variable for debugging */
176 static char *ld_library_path;	/* Environment variable for search path */
177 static char *ld_library_dirs;	/* Environment variable for library descriptors */
178 static char *ld_preload;	/* Environment variable for libraries to
179 				   load first */
180 static char *ld_elf_hints_path;	/* Environment variable for alternative hints path */
181 static char *ld_tracing;	/* Called from ldd to print libs */
182 static char *ld_utrace;		/* Use utrace() to log events. */
183 static struct obj_entry_q obj_list;	/* Queue of all loaded objects */
184 static Obj_Entry *obj_main;	/* The main program shared object */
185 static Obj_Entry obj_rtld;	/* The dynamic linker shared object */
186 static unsigned int obj_count;	/* Number of objects in obj_list */
187 static unsigned int obj_loads;	/* Number of loads of objects (gen count) */
188 
189 static Objlist list_global =	/* Objects dlopened with RTLD_GLOBAL */
190   STAILQ_HEAD_INITIALIZER(list_global);
191 static Objlist list_main =	/* Objects loaded at program startup */
192   STAILQ_HEAD_INITIALIZER(list_main);
193 static Objlist list_fini =	/* Objects needing fini() calls */
194   STAILQ_HEAD_INITIALIZER(list_fini);
195 
196 Elf_Sym sym_zero;		/* For resolving undefined weak refs. */
197 
198 #define GDB_STATE(s,m)	r_debug.r_state = s; r_debug_state(&r_debug,m);
199 
200 extern Elf_Dyn _DYNAMIC;
201 #pragma weak _DYNAMIC
202 #ifndef RTLD_IS_DYNAMIC
203 #define	RTLD_IS_DYNAMIC()	(&_DYNAMIC != NULL)
204 #endif
205 
206 int dlclose(void *) __exported;
207 char *dlerror(void) __exported;
208 void *dlopen(const char *, int) __exported;
209 void *fdlopen(int, int) __exported;
210 void *dlsym(void *, const char *) __exported;
211 dlfunc_t dlfunc(void *, const char *) __exported;
212 void *dlvsym(void *, const char *, const char *) __exported;
213 int dladdr(const void *, Dl_info *) __exported;
214 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *),
215     void (*)(void *), void (*)(void *), void (*)(void *)) __exported;
216 int dlinfo(void *, int , void *) __exported;
217 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported;
218 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported;
219 int _rtld_get_stack_prot(void) __exported;
220 int _rtld_is_dlopened(void *) __exported;
221 void _rtld_error(const char *, ...) __exported;
222 
223 int npagesizes, osreldate;
224 size_t *pagesizes;
225 
226 long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
227 
228 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC;
229 static int max_stack_flags;
230 
231 /*
232  * Global declarations normally provided by crt1.  The dynamic linker is
233  * not built with crt1, so we have to provide them ourselves.
234  */
235 char *__progname;
236 char **environ;
237 
238 /*
239  * Used to pass argc, argv to init functions.
240  */
241 int main_argc;
242 char **main_argv;
243 
244 /*
245  * Globals to control TLS allocation.
246  */
247 size_t tls_last_offset;		/* Static TLS offset of last module */
248 size_t tls_last_size;		/* Static TLS size of last module */
249 size_t tls_static_space;	/* Static TLS space allocated */
250 size_t tls_static_max_align;
251 int tls_dtv_generation = 1;	/* Used to detect when dtv size changes  */
252 int tls_max_index = 1;		/* Largest module index allocated */
253 
254 bool ld_library_path_rpath = false;
255 
256 /*
257  * Globals for path names, and such
258  */
259 char *ld_elf_hints_default = _PATH_ELF_HINTS;
260 char *ld_path_libmap_conf = _PATH_LIBMAP_CONF;
261 char *ld_path_rtld = _PATH_RTLD;
262 char *ld_standard_library_path = STANDARD_LIBRARY_PATH;
263 char *ld_env_prefix = LD_;
264 
265 /*
266  * Fill in a DoneList with an allocation large enough to hold all of
267  * the currently-loaded objects.  Keep this as a macro since it calls
268  * alloca and we want that to occur within the scope of the caller.
269  */
270 #define donelist_init(dlp)					\
271     ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]),	\
272     assert((dlp)->objs != NULL),				\
273     (dlp)->num_alloc = obj_count,				\
274     (dlp)->num_used = 0)
275 
276 #define	UTRACE_DLOPEN_START		1
277 #define	UTRACE_DLOPEN_STOP		2
278 #define	UTRACE_DLCLOSE_START		3
279 #define	UTRACE_DLCLOSE_STOP		4
280 #define	UTRACE_LOAD_OBJECT		5
281 #define	UTRACE_UNLOAD_OBJECT		6
282 #define	UTRACE_ADD_RUNDEP		7
283 #define	UTRACE_PRELOAD_FINISHED		8
284 #define	UTRACE_INIT_CALL		9
285 #define	UTRACE_FINI_CALL		10
286 #define	UTRACE_DLSYM_START		11
287 #define	UTRACE_DLSYM_STOP		12
288 
289 struct utrace_rtld {
290 	char sig[4];			/* 'RTLD' */
291 	int event;
292 	void *handle;
293 	void *mapbase;			/* Used for 'parent' and 'init/fini' */
294 	size_t mapsize;
295 	int refcnt;			/* Used for 'mode' */
296 	char name[MAXPATHLEN];
297 };
298 
299 #define	LD_UTRACE(e, h, mb, ms, r, n) do {			\
300 	if (ld_utrace != NULL)					\
301 		ld_utrace_log(e, h, mb, ms, r, n);		\
302 } while (0)
303 
304 static void
305 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
306     int refcnt, const char *name)
307 {
308 	struct utrace_rtld ut;
309 
310 	ut.sig[0] = 'R';
311 	ut.sig[1] = 'T';
312 	ut.sig[2] = 'L';
313 	ut.sig[3] = 'D';
314 	ut.event = event;
315 	ut.handle = handle;
316 	ut.mapbase = mapbase;
317 	ut.mapsize = mapsize;
318 	ut.refcnt = refcnt;
319 	bzero(ut.name, sizeof(ut.name));
320 	if (name)
321 		strlcpy(ut.name, name, sizeof(ut.name));
322 	utrace(&ut, sizeof(ut));
323 }
324 
325 #ifdef RTLD_VARIANT_ENV_NAMES
326 /*
327  * construct the env variable based on the type of binary that's
328  * running.
329  */
330 static inline const char *
331 _LD(const char *var)
332 {
333 	static char buffer[128];
334 
335 	strlcpy(buffer, ld_env_prefix, sizeof(buffer));
336 	strlcat(buffer, var, sizeof(buffer));
337 	return (buffer);
338 }
339 #else
340 #define _LD(x)	LD_ x
341 #endif
342 
343 /*
344  * Main entry point for dynamic linking.  The first argument is the
345  * stack pointer.  The stack is expected to be laid out as described
346  * in the SVR4 ABI specification, Intel 386 Processor Supplement.
347  * Specifically, the stack pointer points to a word containing
348  * ARGC.  Following that in the stack is a null-terminated sequence
349  * of pointers to argument strings.  Then comes a null-terminated
350  * sequence of pointers to environment strings.  Finally, there is a
351  * sequence of "auxiliary vector" entries.
352  *
353  * The second argument points to a place to store the dynamic linker's
354  * exit procedure pointer and the third to a place to store the main
355  * program's object.
356  *
357  * The return value is the main program's entry point.
358  */
359 func_ptr_type
360 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
361 {
362     Elf_Auxinfo *aux_info[AT_COUNT];
363     int i;
364     int argc;
365     char **argv;
366     char **env;
367     Elf_Auxinfo *aux;
368     Elf_Auxinfo *auxp;
369     const char *argv0;
370     Objlist_Entry *entry;
371     Obj_Entry *obj;
372     Obj_Entry *preload_tail;
373     Obj_Entry *last_interposer;
374     Objlist initlist;
375     RtldLockState lockstate;
376     char *library_path_rpath;
377     int mib[2];
378     size_t len;
379 
380     /*
381      * On entry, the dynamic linker itself has not been relocated yet.
382      * Be very careful not to reference any global data until after
383      * init_rtld has returned.  It is OK to reference file-scope statics
384      * and string constants, and to call static and global functions.
385      */
386 
387     /* Find the auxiliary vector on the stack. */
388     argc = *sp++;
389     argv = (char **) sp;
390     sp += argc + 1;	/* Skip over arguments and NULL terminator */
391     env = (char **) sp;
392     while (*sp++ != 0)	/* Skip over environment, and NULL terminator */
393 	;
394     aux = (Elf_Auxinfo *) sp;
395 
396     /* Digest the auxiliary vector. */
397     for (i = 0;  i < AT_COUNT;  i++)
398 	aux_info[i] = NULL;
399     for (auxp = aux;  auxp->a_type != AT_NULL;  auxp++) {
400 	if (auxp->a_type < AT_COUNT)
401 	    aux_info[auxp->a_type] = auxp;
402     }
403 
404     /* Initialize and relocate ourselves. */
405     assert(aux_info[AT_BASE] != NULL);
406     init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
407 
408     __progname = obj_rtld.path;
409     argv0 = argv[0] != NULL ? argv[0] : "(null)";
410     environ = env;
411     main_argc = argc;
412     main_argv = argv;
413 
414     if (aux_info[AT_CANARY] != NULL &&
415 	aux_info[AT_CANARY]->a_un.a_ptr != NULL) {
416 	    i = aux_info[AT_CANARYLEN]->a_un.a_val;
417 	    if (i > sizeof(__stack_chk_guard))
418 		    i = sizeof(__stack_chk_guard);
419 	    memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i);
420     } else {
421 	mib[0] = CTL_KERN;
422 	mib[1] = KERN_ARND;
423 
424 	len = sizeof(__stack_chk_guard);
425 	if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 ||
426 	    len != sizeof(__stack_chk_guard)) {
427 		/* If sysctl was unsuccessful, use the "terminator canary". */
428 		((unsigned char *)(void *)__stack_chk_guard)[0] = 0;
429 		((unsigned char *)(void *)__stack_chk_guard)[1] = 0;
430 		((unsigned char *)(void *)__stack_chk_guard)[2] = '\n';
431 		((unsigned char *)(void *)__stack_chk_guard)[3] = 255;
432 	}
433     }
434 
435     trust = !issetugid();
436 
437     md_abi_variant_hook(aux_info);
438 
439     ld_bind_now = getenv(_LD("BIND_NOW"));
440     /*
441      * If the process is tainted, then we un-set the dangerous environment
442      * variables.  The process will be marked as tainted until setuid(2)
443      * is called.  If any child process calls setuid(2) we do not want any
444      * future processes to honor the potentially un-safe variables.
445      */
446     if (!trust) {
447 	if (unsetenv(_LD("PRELOAD")) || unsetenv(_LD("LIBMAP")) ||
448 	    unsetenv(_LD("LIBRARY_PATH")) || unsetenv(_LD("LIBRARY_PATH_FDS")) ||
449 	    unsetenv(_LD("LIBMAP_DISABLE")) ||
450 	    unsetenv(_LD("DEBUG")) || unsetenv(_LD("ELF_HINTS_PATH")) ||
451 	    unsetenv(_LD("LOADFLTR")) || unsetenv(_LD("LIBRARY_PATH_RPATH"))) {
452 		_rtld_error("environment corrupt; aborting");
453 		rtld_die();
454 	}
455     }
456     ld_debug = getenv(_LD("DEBUG"));
457     libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL;
458     libmap_override = getenv(_LD("LIBMAP"));
459     ld_library_path = getenv(_LD("LIBRARY_PATH"));
460     ld_library_dirs = getenv(_LD("LIBRARY_PATH_FDS"));
461     ld_preload = getenv(_LD("PRELOAD"));
462     ld_elf_hints_path = getenv(_LD("ELF_HINTS_PATH"));
463     ld_loadfltr = getenv(_LD("LOADFLTR")) != NULL;
464     library_path_rpath = getenv(_LD("LIBRARY_PATH_RPATH"));
465     if (library_path_rpath != NULL) {
466 	    if (library_path_rpath[0] == 'y' ||
467 		library_path_rpath[0] == 'Y' ||
468 		library_path_rpath[0] == '1')
469 		    ld_library_path_rpath = true;
470 	    else
471 		    ld_library_path_rpath = false;
472     }
473     dangerous_ld_env = libmap_disable || (libmap_override != NULL) ||
474 	(ld_library_path != NULL) || (ld_preload != NULL) ||
475 	(ld_elf_hints_path != NULL) || ld_loadfltr;
476     ld_tracing = getenv(_LD("TRACE_LOADED_OBJECTS"));
477     ld_utrace = getenv(_LD("UTRACE"));
478 
479     if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
480 	ld_elf_hints_path = ld_elf_hints_default;
481 
482     if (ld_debug != NULL && *ld_debug != '\0')
483 	debug = 1;
484     dbg("%s is initialized, base address = %p", __progname,
485 	(caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
486     dbg("RTLD dynamic = %p", obj_rtld.dynamic);
487     dbg("RTLD pltgot  = %p", obj_rtld.pltgot);
488 
489     dbg("initializing thread locks");
490     lockdflt_init();
491 
492     /*
493      * Load the main program, or process its program header if it is
494      * already loaded.
495      */
496     if (aux_info[AT_EXECFD] != NULL) {	/* Load the main program. */
497 	int fd = aux_info[AT_EXECFD]->a_un.a_val;
498 	dbg("loading main program");
499 	obj_main = map_object(fd, argv0, NULL);
500 	close(fd);
501 	if (obj_main == NULL)
502 	    rtld_die();
503 	max_stack_flags = obj->stack_flags;
504     } else {				/* Main program already loaded. */
505 	const Elf_Phdr *phdr;
506 	int phnum;
507 	caddr_t entry;
508 
509 	dbg("processing main program's program header");
510 	assert(aux_info[AT_PHDR] != NULL);
511 	phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
512 	assert(aux_info[AT_PHNUM] != NULL);
513 	phnum = aux_info[AT_PHNUM]->a_un.a_val;
514 	assert(aux_info[AT_PHENT] != NULL);
515 	assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
516 	assert(aux_info[AT_ENTRY] != NULL);
517 	entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
518 	if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
519 	    rtld_die();
520     }
521 
522     if (aux_info[AT_EXECPATH] != 0) {
523 	    char *kexecpath;
524 	    char buf[MAXPATHLEN];
525 
526 	    kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
527 	    dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
528 	    if (kexecpath[0] == '/')
529 		    obj_main->path = kexecpath;
530 	    else if (getcwd(buf, sizeof(buf)) == NULL ||
531 		     strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
532 		     strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
533 		    obj_main->path = xstrdup(argv0);
534 	    else
535 		    obj_main->path = xstrdup(buf);
536     } else {
537 	    dbg("No AT_EXECPATH");
538 	    obj_main->path = xstrdup(argv0);
539     }
540     dbg("obj_main path %s", obj_main->path);
541     obj_main->mainprog = true;
542 
543     if (aux_info[AT_STACKPROT] != NULL &&
544       aux_info[AT_STACKPROT]->a_un.a_val != 0)
545 	    stack_prot = aux_info[AT_STACKPROT]->a_un.a_val;
546 
547 #ifndef COMPAT_32BIT
548     /*
549      * Get the actual dynamic linker pathname from the executable if
550      * possible.  (It should always be possible.)  That ensures that
551      * gdb will find the right dynamic linker even if a non-standard
552      * one is being used.
553      */
554     if (obj_main->interp != NULL &&
555       strcmp(obj_main->interp, obj_rtld.path) != 0) {
556 	free(obj_rtld.path);
557 	obj_rtld.path = xstrdup(obj_main->interp);
558         __progname = obj_rtld.path;
559     }
560 #endif
561 
562     digest_dynamic(obj_main, 0);
563     dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d",
564 	obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu,
565 	obj_main->dynsymcount);
566 
567     linkmap_add(obj_main);
568     linkmap_add(&obj_rtld);
569 
570     /* Link the main program into the list of objects. */
571     TAILQ_INSERT_HEAD(&obj_list, obj_main, next);
572     obj_count++;
573     obj_loads++;
574 
575     /* Initialize a fake symbol for resolving undefined weak references. */
576     sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
577     sym_zero.st_shndx = SHN_UNDEF;
578     sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
579 
580     if (!libmap_disable)
581         libmap_disable = (bool)lm_init(libmap_override);
582 
583     dbg("loading LD_PRELOAD libraries");
584     if (load_preload_objects() == -1)
585 	rtld_die();
586     preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q));
587 
588     dbg("loading needed objects");
589     if (load_needed_objects(obj_main, 0) == -1)
590 	rtld_die();
591 
592     /* Make a list of all objects loaded at startup. */
593     last_interposer = obj_main;
594     TAILQ_FOREACH(obj, &obj_list, next) {
595 	if (obj->marker)
596 	    continue;
597 	if (obj->z_interpose && obj != obj_main) {
598 	    objlist_put_after(&list_main, last_interposer, obj);
599 	    last_interposer = obj;
600 	} else {
601 	    objlist_push_tail(&list_main, obj);
602 	}
603     	obj->refcount++;
604     }
605 
606     dbg("checking for required versions");
607     if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
608 	rtld_die();
609 
610     if (ld_tracing) {		/* We're done */
611 	trace_loaded_objects(obj_main);
612 	exit(0);
613     }
614 
615     if (getenv(_LD("DUMP_REL_PRE")) != NULL) {
616        dump_relocations(obj_main);
617        exit (0);
618     }
619 
620     /*
621      * Processing tls relocations requires having the tls offsets
622      * initialized.  Prepare offsets before starting initial
623      * relocation processing.
624      */
625     dbg("initializing initial thread local storage offsets");
626     STAILQ_FOREACH(entry, &list_main, link) {
627 	/*
628 	 * Allocate all the initial objects out of the static TLS
629 	 * block even if they didn't ask for it.
630 	 */
631 	allocate_tls_offset(entry->obj);
632     }
633 
634     if (relocate_objects(obj_main,
635       ld_bind_now != NULL && *ld_bind_now != '\0',
636       &obj_rtld, SYMLOOK_EARLY, NULL) == -1)
637 	rtld_die();
638 
639     dbg("doing copy relocations");
640     if (do_copy_relocations(obj_main) == -1)
641 	rtld_die();
642 
643     if (getenv(_LD("DUMP_REL_POST")) != NULL) {
644        dump_relocations(obj_main);
645        exit (0);
646     }
647 
648     /*
649      * Setup TLS for main thread.  This must be done after the
650      * relocations are processed, since tls initialization section
651      * might be the subject for relocations.
652      */
653     dbg("initializing initial thread local storage");
654     allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list)));
655 
656     dbg("initializing key program variables");
657     set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
658     set_program_var("environ", env);
659     set_program_var("__elf_aux_vector", aux);
660 
661     /* Make a list of init functions to call. */
662     objlist_init(&initlist);
663     initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)),
664       preload_tail, &initlist);
665 
666     r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
667 
668     map_stacks_exec(NULL);
669 
670     dbg("resolving ifuncs");
671     if (resolve_objects_ifunc(obj_main,
672       ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY,
673       NULL) == -1)
674 	rtld_die();
675 
676     if (!obj_main->crt_no_init) {
677 	/*
678 	 * Make sure we don't call the main program's init and fini
679 	 * functions for binaries linked with old crt1 which calls
680 	 * _init itself.
681 	 */
682 	obj_main->init = obj_main->fini = (Elf_Addr)NULL;
683 	obj_main->preinit_array = obj_main->init_array =
684 	    obj_main->fini_array = (Elf_Addr)NULL;
685     }
686 
687     wlock_acquire(rtld_bind_lock, &lockstate);
688     if (obj_main->crt_no_init)
689 	preinit_main();
690     objlist_call_init(&initlist, &lockstate);
691     _r_debug_postinit(&obj_main->linkmap);
692     objlist_clear(&initlist);
693     dbg("loading filtees");
694     TAILQ_FOREACH(obj, &obj_list, next) {
695 	if (obj->marker)
696 	    continue;
697 	if (ld_loadfltr || obj->z_loadfltr)
698 	    load_filtees(obj, 0, &lockstate);
699     }
700     lock_release(rtld_bind_lock, &lockstate);
701 
702     dbg("transferring control to program entry point = %p", obj_main->entry);
703 
704     /* Return the exit procedure and the program entry point. */
705     *exit_proc = rtld_exit;
706     *objp = obj_main;
707     return (func_ptr_type) obj_main->entry;
708 }
709 
710 void *
711 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def)
712 {
713 	void *ptr;
714 	Elf_Addr target;
715 
716 	ptr = (void *)make_function_pointer(def, obj);
717 	target = ((Elf_Addr (*)(void))ptr)();
718 	return ((void *)target);
719 }
720 
721 Elf_Addr
722 _rtld_bind(Obj_Entry *obj, Elf_Size reloff)
723 {
724     const Elf_Rel *rel;
725     const Elf_Sym *def;
726     const Obj_Entry *defobj;
727     Elf_Addr *where;
728     Elf_Addr target;
729     RtldLockState lockstate;
730 
731     rlock_acquire(rtld_bind_lock, &lockstate);
732     if (sigsetjmp(lockstate.env, 0) != 0)
733 	    lock_upgrade(rtld_bind_lock, &lockstate);
734     if (obj->pltrel)
735 	rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
736     else
737 	rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
738 
739     where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
740     def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL,
741 	&lockstate);
742     if (def == NULL)
743 	rtld_die();
744     if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
745 	target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
746     else
747 	target = (Elf_Addr)(defobj->relocbase + def->st_value);
748 
749     dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
750       defobj->strtab + def->st_name, basename(obj->path),
751       (void *)target, basename(defobj->path));
752 
753     /*
754      * Write the new contents for the jmpslot. Note that depending on
755      * architecture, the value which we need to return back to the
756      * lazy binding trampoline may or may not be the target
757      * address. The value returned from reloc_jmpslot() is the value
758      * that the trampoline needs.
759      */
760     target = reloc_jmpslot(where, target, defobj, obj, rel);
761     lock_release(rtld_bind_lock, &lockstate);
762     return target;
763 }
764 
765 /*
766  * Error reporting function.  Use it like printf.  If formats the message
767  * into a buffer, and sets things up so that the next call to dlerror()
768  * will return the message.
769  */
770 void
771 _rtld_error(const char *fmt, ...)
772 {
773     static char buf[512];
774     va_list ap;
775 
776     va_start(ap, fmt);
777     rtld_vsnprintf(buf, sizeof buf, fmt, ap);
778     error_message = buf;
779     va_end(ap);
780 }
781 
782 /*
783  * Return a dynamically-allocated copy of the current error message, if any.
784  */
785 static char *
786 errmsg_save(void)
787 {
788     return error_message == NULL ? NULL : xstrdup(error_message);
789 }
790 
791 /*
792  * Restore the current error message from a copy which was previously saved
793  * by errmsg_save().  The copy is freed.
794  */
795 static void
796 errmsg_restore(char *saved_msg)
797 {
798     if (saved_msg == NULL)
799 	error_message = NULL;
800     else {
801 	_rtld_error("%s", saved_msg);
802 	free(saved_msg);
803     }
804 }
805 
806 static const char *
807 basename(const char *name)
808 {
809     const char *p = strrchr(name, '/');
810     return p != NULL ? p + 1 : name;
811 }
812 
813 static struct utsname uts;
814 
815 static char *
816 origin_subst_one(Obj_Entry *obj, char *real, const char *kw,
817     const char *subst, bool may_free)
818 {
819 	char *p, *p1, *res, *resp;
820 	int subst_len, kw_len, subst_count, old_len, new_len;
821 
822 	kw_len = strlen(kw);
823 
824 	/*
825 	 * First, count the number of the keyword occurences, to
826 	 * preallocate the final string.
827 	 */
828 	for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) {
829 		p1 = strstr(p, kw);
830 		if (p1 == NULL)
831 			break;
832 	}
833 
834 	/*
835 	 * If the keyword is not found, just return.
836 	 *
837 	 * Return non-substituted string if resolution failed.  We
838 	 * cannot do anything more reasonable, the failure mode of the
839 	 * caller is unresolved library anyway.
840 	 */
841 	if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj)))
842 		return (may_free ? real : xstrdup(real));
843 	if (obj != NULL)
844 		subst = obj->origin_path;
845 
846 	/*
847 	 * There is indeed something to substitute.  Calculate the
848 	 * length of the resulting string, and allocate it.
849 	 */
850 	subst_len = strlen(subst);
851 	old_len = strlen(real);
852 	new_len = old_len + (subst_len - kw_len) * subst_count;
853 	res = xmalloc(new_len + 1);
854 
855 	/*
856 	 * Now, execute the substitution loop.
857 	 */
858 	for (p = real, resp = res, *resp = '\0';;) {
859 		p1 = strstr(p, kw);
860 		if (p1 != NULL) {
861 			/* Copy the prefix before keyword. */
862 			memcpy(resp, p, p1 - p);
863 			resp += p1 - p;
864 			/* Keyword replacement. */
865 			memcpy(resp, subst, subst_len);
866 			resp += subst_len;
867 			*resp = '\0';
868 			p = p1 + kw_len;
869 		} else
870 			break;
871 	}
872 
873 	/* Copy to the end of string and finish. */
874 	strcat(resp, p);
875 	if (may_free)
876 		free(real);
877 	return (res);
878 }
879 
880 static char *
881 origin_subst(Obj_Entry *obj, char *real)
882 {
883 	char *res1, *res2, *res3, *res4;
884 
885 	if (obj == NULL || !trust)
886 		return (xstrdup(real));
887 	if (uts.sysname[0] == '\0') {
888 		if (uname(&uts) != 0) {
889 			_rtld_error("utsname failed: %d", errno);
890 			return (NULL);
891 		}
892 	}
893 	res1 = origin_subst_one(obj, real, "$ORIGIN", NULL, false);
894 	res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true);
895 	res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true);
896 	res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true);
897 	return (res4);
898 }
899 
900 void
901 rtld_die(void)
902 {
903     const char *msg = dlerror();
904 
905     if (msg == NULL)
906 	msg = "Fatal error";
907     rtld_fdputstr(STDERR_FILENO, msg);
908     rtld_fdputchar(STDERR_FILENO, '\n');
909     _exit(1);
910 }
911 
912 /*
913  * Process a shared object's DYNAMIC section, and save the important
914  * information in its Obj_Entry structure.
915  */
916 static void
917 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
918     const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath)
919 {
920     const Elf_Dyn *dynp;
921     Needed_Entry **needed_tail = &obj->needed;
922     Needed_Entry **needed_filtees_tail = &obj->needed_filtees;
923     Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees;
924     const Elf_Hashelt *hashtab;
925     const Elf32_Word *hashval;
926     Elf32_Word bkt, nmaskwords;
927     int bloom_size32;
928     int plttype = DT_REL;
929 
930     *dyn_rpath = NULL;
931     *dyn_soname = NULL;
932     *dyn_runpath = NULL;
933 
934     obj->bind_now = false;
935     for (dynp = obj->dynamic;  dynp->d_tag != DT_NULL;  dynp++) {
936 	switch (dynp->d_tag) {
937 
938 	case DT_REL:
939 	    obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
940 	    break;
941 
942 	case DT_RELSZ:
943 	    obj->relsize = dynp->d_un.d_val;
944 	    break;
945 
946 	case DT_RELENT:
947 	    assert(dynp->d_un.d_val == sizeof(Elf_Rel));
948 	    break;
949 
950 	case DT_JMPREL:
951 	    obj->pltrel = (const Elf_Rel *)
952 	      (obj->relocbase + dynp->d_un.d_ptr);
953 	    break;
954 
955 	case DT_PLTRELSZ:
956 	    obj->pltrelsize = dynp->d_un.d_val;
957 	    break;
958 
959 	case DT_RELA:
960 	    obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
961 	    break;
962 
963 	case DT_RELASZ:
964 	    obj->relasize = dynp->d_un.d_val;
965 	    break;
966 
967 	case DT_RELAENT:
968 	    assert(dynp->d_un.d_val == sizeof(Elf_Rela));
969 	    break;
970 
971 	case DT_PLTREL:
972 	    plttype = dynp->d_un.d_val;
973 	    assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
974 	    break;
975 
976 	case DT_SYMTAB:
977 	    obj->symtab = (const Elf_Sym *)
978 	      (obj->relocbase + dynp->d_un.d_ptr);
979 	    break;
980 
981 	case DT_SYMENT:
982 	    assert(dynp->d_un.d_val == sizeof(Elf_Sym));
983 	    break;
984 
985 	case DT_STRTAB:
986 	    obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
987 	    break;
988 
989 	case DT_STRSZ:
990 	    obj->strsize = dynp->d_un.d_val;
991 	    break;
992 
993 	case DT_VERNEED:
994 	    obj->verneed = (const Elf_Verneed *) (obj->relocbase +
995 		dynp->d_un.d_val);
996 	    break;
997 
998 	case DT_VERNEEDNUM:
999 	    obj->verneednum = dynp->d_un.d_val;
1000 	    break;
1001 
1002 	case DT_VERDEF:
1003 	    obj->verdef = (const Elf_Verdef *) (obj->relocbase +
1004 		dynp->d_un.d_val);
1005 	    break;
1006 
1007 	case DT_VERDEFNUM:
1008 	    obj->verdefnum = dynp->d_un.d_val;
1009 	    break;
1010 
1011 	case DT_VERSYM:
1012 	    obj->versyms = (const Elf_Versym *)(obj->relocbase +
1013 		dynp->d_un.d_val);
1014 	    break;
1015 
1016 	case DT_HASH:
1017 	    {
1018 		hashtab = (const Elf_Hashelt *)(obj->relocbase +
1019 		    dynp->d_un.d_ptr);
1020 		obj->nbuckets = hashtab[0];
1021 		obj->nchains = hashtab[1];
1022 		obj->buckets = hashtab + 2;
1023 		obj->chains = obj->buckets + obj->nbuckets;
1024 		obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 &&
1025 		  obj->buckets != NULL;
1026 	    }
1027 	    break;
1028 
1029 	case DT_GNU_HASH:
1030 	    {
1031 		hashtab = (const Elf_Hashelt *)(obj->relocbase +
1032 		    dynp->d_un.d_ptr);
1033 		obj->nbuckets_gnu = hashtab[0];
1034 		obj->symndx_gnu = hashtab[1];
1035 		nmaskwords = hashtab[2];
1036 		bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords;
1037 		obj->maskwords_bm_gnu = nmaskwords - 1;
1038 		obj->shift2_gnu = hashtab[3];
1039 		obj->bloom_gnu = (Elf_Addr *) (hashtab + 4);
1040 		obj->buckets_gnu = hashtab + 4 + bloom_size32;
1041 		obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu -
1042 		  obj->symndx_gnu;
1043 		/* Number of bitmask words is required to be power of 2 */
1044 		obj->valid_hash_gnu = powerof2(nmaskwords) &&
1045 		    obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL;
1046 	    }
1047 	    break;
1048 
1049 	case DT_NEEDED:
1050 	    if (!obj->rtld) {
1051 		Needed_Entry *nep = NEW(Needed_Entry);
1052 		nep->name = dynp->d_un.d_val;
1053 		nep->obj = NULL;
1054 		nep->next = NULL;
1055 
1056 		*needed_tail = nep;
1057 		needed_tail = &nep->next;
1058 	    }
1059 	    break;
1060 
1061 	case DT_FILTER:
1062 	    if (!obj->rtld) {
1063 		Needed_Entry *nep = NEW(Needed_Entry);
1064 		nep->name = dynp->d_un.d_val;
1065 		nep->obj = NULL;
1066 		nep->next = NULL;
1067 
1068 		*needed_filtees_tail = nep;
1069 		needed_filtees_tail = &nep->next;
1070 	    }
1071 	    break;
1072 
1073 	case DT_AUXILIARY:
1074 	    if (!obj->rtld) {
1075 		Needed_Entry *nep = NEW(Needed_Entry);
1076 		nep->name = dynp->d_un.d_val;
1077 		nep->obj = NULL;
1078 		nep->next = NULL;
1079 
1080 		*needed_aux_filtees_tail = nep;
1081 		needed_aux_filtees_tail = &nep->next;
1082 	    }
1083 	    break;
1084 
1085 	case DT_PLTGOT:
1086 	    obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
1087 	    break;
1088 
1089 	case DT_TEXTREL:
1090 	    obj->textrel = true;
1091 	    break;
1092 
1093 	case DT_SYMBOLIC:
1094 	    obj->symbolic = true;
1095 	    break;
1096 
1097 	case DT_RPATH:
1098 	    /*
1099 	     * We have to wait until later to process this, because we
1100 	     * might not have gotten the address of the string table yet.
1101 	     */
1102 	    *dyn_rpath = dynp;
1103 	    break;
1104 
1105 	case DT_SONAME:
1106 	    *dyn_soname = dynp;
1107 	    break;
1108 
1109 	case DT_RUNPATH:
1110 	    *dyn_runpath = dynp;
1111 	    break;
1112 
1113 	case DT_INIT:
1114 	    obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1115 	    break;
1116 
1117 	case DT_PREINIT_ARRAY:
1118 	    obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1119 	    break;
1120 
1121 	case DT_PREINIT_ARRAYSZ:
1122 	    obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1123 	    break;
1124 
1125 	case DT_INIT_ARRAY:
1126 	    obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1127 	    break;
1128 
1129 	case DT_INIT_ARRAYSZ:
1130 	    obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1131 	    break;
1132 
1133 	case DT_FINI:
1134 	    obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1135 	    break;
1136 
1137 	case DT_FINI_ARRAY:
1138 	    obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1139 	    break;
1140 
1141 	case DT_FINI_ARRAYSZ:
1142 	    obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1143 	    break;
1144 
1145 	/*
1146 	 * Don't process DT_DEBUG on MIPS as the dynamic section
1147 	 * is mapped read-only. DT_MIPS_RLD_MAP is used instead.
1148 	 */
1149 
1150 #ifndef __mips__
1151 	case DT_DEBUG:
1152 	    if (!early)
1153 		dbg("Filling in DT_DEBUG entry");
1154 	    ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
1155 	    break;
1156 #endif
1157 
1158 	case DT_FLAGS:
1159 		if (dynp->d_un.d_val & DF_ORIGIN)
1160 		    obj->z_origin = true;
1161 		if (dynp->d_un.d_val & DF_SYMBOLIC)
1162 		    obj->symbolic = true;
1163 		if (dynp->d_un.d_val & DF_TEXTREL)
1164 		    obj->textrel = true;
1165 		if (dynp->d_un.d_val & DF_BIND_NOW)
1166 		    obj->bind_now = true;
1167 		/*if (dynp->d_un.d_val & DF_STATIC_TLS)
1168 		    ;*/
1169 	    break;
1170 #ifdef __mips__
1171 	case DT_MIPS_LOCAL_GOTNO:
1172 		obj->local_gotno = dynp->d_un.d_val;
1173 		break;
1174 
1175 	case DT_MIPS_SYMTABNO:
1176 		obj->symtabno = dynp->d_un.d_val;
1177 		break;
1178 
1179 	case DT_MIPS_GOTSYM:
1180 		obj->gotsym = dynp->d_un.d_val;
1181 		break;
1182 
1183 	case DT_MIPS_RLD_MAP:
1184 		*((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug;
1185 		break;
1186 #endif
1187 
1188 #ifdef __powerpc64__
1189 	case DT_PPC64_GLINK:
1190 		obj->glink = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1191 		break;
1192 #endif
1193 
1194 	case DT_FLAGS_1:
1195 		if (dynp->d_un.d_val & DF_1_NOOPEN)
1196 		    obj->z_noopen = true;
1197 		if (dynp->d_un.d_val & DF_1_ORIGIN)
1198 		    obj->z_origin = true;
1199 		if (dynp->d_un.d_val & DF_1_GLOBAL)
1200 		    obj->z_global = true;
1201 		if (dynp->d_un.d_val & DF_1_BIND_NOW)
1202 		    obj->bind_now = true;
1203 		if (dynp->d_un.d_val & DF_1_NODELETE)
1204 		    obj->z_nodelete = true;
1205 		if (dynp->d_un.d_val & DF_1_LOADFLTR)
1206 		    obj->z_loadfltr = true;
1207 		if (dynp->d_un.d_val & DF_1_INTERPOSE)
1208 		    obj->z_interpose = true;
1209 		if (dynp->d_un.d_val & DF_1_NODEFLIB)
1210 		    obj->z_nodeflib = true;
1211 	    break;
1212 
1213 	default:
1214 	    if (!early) {
1215 		dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
1216 		    (long)dynp->d_tag);
1217 	    }
1218 	    break;
1219 	}
1220     }
1221 
1222     obj->traced = false;
1223 
1224     if (plttype == DT_RELA) {
1225 	obj->pltrela = (const Elf_Rela *) obj->pltrel;
1226 	obj->pltrel = NULL;
1227 	obj->pltrelasize = obj->pltrelsize;
1228 	obj->pltrelsize = 0;
1229     }
1230 
1231     /* Determine size of dynsym table (equal to nchains of sysv hash) */
1232     if (obj->valid_hash_sysv)
1233 	obj->dynsymcount = obj->nchains;
1234     else if (obj->valid_hash_gnu) {
1235 	obj->dynsymcount = 0;
1236 	for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) {
1237 	    if (obj->buckets_gnu[bkt] == 0)
1238 		continue;
1239 	    hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]];
1240 	    do
1241 		obj->dynsymcount++;
1242 	    while ((*hashval++ & 1u) == 0);
1243 	}
1244 	obj->dynsymcount += obj->symndx_gnu;
1245     }
1246 }
1247 
1248 static bool
1249 obj_resolve_origin(Obj_Entry *obj)
1250 {
1251 
1252 	if (obj->origin_path != NULL)
1253 		return (true);
1254 	obj->origin_path = xmalloc(PATH_MAX);
1255 	return (rtld_dirname_abs(obj->path, obj->origin_path) != -1);
1256 }
1257 
1258 static void
1259 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
1260     const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath)
1261 {
1262 
1263 	if (obj->z_origin && !obj_resolve_origin(obj))
1264 		rtld_die();
1265 
1266 	if (dyn_runpath != NULL) {
1267 		obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val;
1268 		obj->runpath = origin_subst(obj, obj->runpath);
1269 	} else if (dyn_rpath != NULL) {
1270 		obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
1271 		obj->rpath = origin_subst(obj, obj->rpath);
1272 	}
1273 	if (dyn_soname != NULL)
1274 		object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
1275 }
1276 
1277 static void
1278 digest_dynamic(Obj_Entry *obj, int early)
1279 {
1280 	const Elf_Dyn *dyn_rpath;
1281 	const Elf_Dyn *dyn_soname;
1282 	const Elf_Dyn *dyn_runpath;
1283 
1284 	digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath);
1285 	digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath);
1286 }
1287 
1288 /*
1289  * Process a shared object's program header.  This is used only for the
1290  * main program, when the kernel has already loaded the main program
1291  * into memory before calling the dynamic linker.  It creates and
1292  * returns an Obj_Entry structure.
1293  */
1294 static Obj_Entry *
1295 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
1296 {
1297     Obj_Entry *obj;
1298     const Elf_Phdr *phlimit = phdr + phnum;
1299     const Elf_Phdr *ph;
1300     Elf_Addr note_start, note_end;
1301     int nsegs = 0;
1302 
1303     obj = obj_new();
1304     for (ph = phdr;  ph < phlimit;  ph++) {
1305 	if (ph->p_type != PT_PHDR)
1306 	    continue;
1307 
1308 	obj->phdr = phdr;
1309 	obj->phsize = ph->p_memsz;
1310 	obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
1311 	break;
1312     }
1313 
1314     obj->stack_flags = PF_X | PF_R | PF_W;
1315 
1316     for (ph = phdr;  ph < phlimit;  ph++) {
1317 	switch (ph->p_type) {
1318 
1319 	case PT_INTERP:
1320 	    obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
1321 	    break;
1322 
1323 	case PT_LOAD:
1324 	    if (nsegs == 0) {	/* First load segment */
1325 		obj->vaddrbase = trunc_page(ph->p_vaddr);
1326 		obj->mapbase = obj->vaddrbase + obj->relocbase;
1327 		obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
1328 		  obj->vaddrbase;
1329 	    } else {		/* Last load segment */
1330 		obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1331 		  obj->vaddrbase;
1332 	    }
1333 	    nsegs++;
1334 	    break;
1335 
1336 	case PT_DYNAMIC:
1337 	    obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
1338 	    break;
1339 
1340 	case PT_TLS:
1341 	    obj->tlsindex = 1;
1342 	    obj->tlssize = ph->p_memsz;
1343 	    obj->tlsalign = ph->p_align;
1344 	    obj->tlsinitsize = ph->p_filesz;
1345 	    obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
1346 	    break;
1347 
1348 	case PT_GNU_STACK:
1349 	    obj->stack_flags = ph->p_flags;
1350 	    break;
1351 
1352 	case PT_GNU_RELRO:
1353 	    obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
1354 	    obj->relro_size = round_page(ph->p_memsz);
1355 	    break;
1356 
1357 	case PT_NOTE:
1358 	    note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr;
1359 	    note_end = note_start + ph->p_filesz;
1360 	    digest_notes(obj, note_start, note_end);
1361 	    break;
1362 	}
1363     }
1364     if (nsegs < 1) {
1365 	_rtld_error("%s: too few PT_LOAD segments", path);
1366 	return NULL;
1367     }
1368 
1369     obj->entry = entry;
1370     return obj;
1371 }
1372 
1373 void
1374 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end)
1375 {
1376 	const Elf_Note *note;
1377 	const char *note_name;
1378 	uintptr_t p;
1379 
1380 	for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end;
1381 	    note = (const Elf_Note *)((const char *)(note + 1) +
1382 	      roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
1383 	      roundup2(note->n_descsz, sizeof(Elf32_Addr)))) {
1384 		if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) ||
1385 		    note->n_descsz != sizeof(int32_t))
1386 			continue;
1387 		if (note->n_type != NT_FREEBSD_ABI_TAG &&
1388 		    note->n_type != NT_FREEBSD_NOINIT_TAG)
1389 			continue;
1390 		note_name = (const char *)(note + 1);
1391 		if (strncmp(NOTE_FREEBSD_VENDOR, note_name,
1392 		    sizeof(NOTE_FREEBSD_VENDOR)) != 0)
1393 			continue;
1394 		switch (note->n_type) {
1395 		case NT_FREEBSD_ABI_TAG:
1396 			/* FreeBSD osrel note */
1397 			p = (uintptr_t)(note + 1);
1398 			p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1399 			obj->osrel = *(const int32_t *)(p);
1400 			dbg("note osrel %d", obj->osrel);
1401 			break;
1402 		case NT_FREEBSD_NOINIT_TAG:
1403 			/* FreeBSD 'crt does not call init' note */
1404 			obj->crt_no_init = true;
1405 			dbg("note crt_no_init");
1406 			break;
1407 		}
1408 	}
1409 }
1410 
1411 static Obj_Entry *
1412 dlcheck(void *handle)
1413 {
1414     Obj_Entry *obj;
1415 
1416     TAILQ_FOREACH(obj, &obj_list, next) {
1417 	if (obj == (Obj_Entry *) handle)
1418 	    break;
1419     }
1420 
1421     if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1422 	_rtld_error("Invalid shared object handle %p", handle);
1423 	return NULL;
1424     }
1425     return obj;
1426 }
1427 
1428 /*
1429  * If the given object is already in the donelist, return true.  Otherwise
1430  * add the object to the list and return false.
1431  */
1432 static bool
1433 donelist_check(DoneList *dlp, const Obj_Entry *obj)
1434 {
1435     unsigned int i;
1436 
1437     for (i = 0;  i < dlp->num_used;  i++)
1438 	if (dlp->objs[i] == obj)
1439 	    return true;
1440     /*
1441      * Our donelist allocation should always be sufficient.  But if
1442      * our threads locking isn't working properly, more shared objects
1443      * could have been loaded since we allocated the list.  That should
1444      * never happen, but we'll handle it properly just in case it does.
1445      */
1446     if (dlp->num_used < dlp->num_alloc)
1447 	dlp->objs[dlp->num_used++] = obj;
1448     return false;
1449 }
1450 
1451 /*
1452  * Hash function for symbol table lookup.  Don't even think about changing
1453  * this.  It is specified by the System V ABI.
1454  */
1455 unsigned long
1456 elf_hash(const char *name)
1457 {
1458     const unsigned char *p = (const unsigned char *) name;
1459     unsigned long h = 0;
1460     unsigned long g;
1461 
1462     while (*p != '\0') {
1463 	h = (h << 4) + *p++;
1464 	if ((g = h & 0xf0000000) != 0)
1465 	    h ^= g >> 24;
1466 	h &= ~g;
1467     }
1468     return h;
1469 }
1470 
1471 /*
1472  * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits
1473  * unsigned in case it's implemented with a wider type.
1474  */
1475 static uint32_t
1476 gnu_hash(const char *s)
1477 {
1478 	uint32_t h;
1479 	unsigned char c;
1480 
1481 	h = 5381;
1482 	for (c = *s; c != '\0'; c = *++s)
1483 		h = h * 33 + c;
1484 	return (h & 0xffffffff);
1485 }
1486 
1487 
1488 /*
1489  * Find the library with the given name, and return its full pathname.
1490  * The returned string is dynamically allocated.  Generates an error
1491  * message and returns NULL if the library cannot be found.
1492  *
1493  * If the second argument is non-NULL, then it refers to an already-
1494  * loaded shared object, whose library search path will be searched.
1495  *
1496  * If a library is successfully located via LD_LIBRARY_PATH_FDS, its
1497  * descriptor (which is close-on-exec) will be passed out via the third
1498  * argument.
1499  *
1500  * The search order is:
1501  *   DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1)
1502  *   DT_RPATH of the main object if DSO without defined DT_RUNPATH (1)
1503  *   LD_LIBRARY_PATH
1504  *   DT_RUNPATH in the referencing file
1505  *   ldconfig hints (if -z nodefaultlib, filter out default library directories
1506  *	 from list)
1507  *   /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib
1508  *
1509  * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined.
1510  */
1511 static char *
1512 find_library(const char *xname, const Obj_Entry *refobj, int *fdp)
1513 {
1514     char *pathname;
1515     char *name;
1516     bool nodeflib, objgiven;
1517 
1518     objgiven = refobj != NULL;
1519     if (strchr(xname, '/') != NULL) {	/* Hard coded pathname */
1520 	if (xname[0] != '/' && !trust) {
1521 	    _rtld_error("Absolute pathname required for shared object \"%s\"",
1522 	      xname);
1523 	    return NULL;
1524 	}
1525 	return (origin_subst(__DECONST(Obj_Entry *, refobj),
1526 	  __DECONST(char *, xname)));
1527     }
1528 
1529     if (libmap_disable || !objgiven ||
1530 	(name = lm_find(refobj->path, xname)) == NULL)
1531 	name = (char *)xname;
1532 
1533     dbg(" Searching for \"%s\"", name);
1534 
1535     /*
1536      * If refobj->rpath != NULL, then refobj->runpath is NULL.  Fall
1537      * back to pre-conforming behaviour if user requested so with
1538      * LD_LIBRARY_PATH_RPATH environment variable and ignore -z
1539      * nodeflib.
1540      */
1541     if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) {
1542 	if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
1543 	  (refobj != NULL &&
1544 	  (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1545 	  (pathname = search_library_pathfds(name, ld_library_dirs, fdp)) != NULL ||
1546           (pathname = search_library_path(name, gethints(false))) != NULL ||
1547 	  (pathname = search_library_path(name, ld_standard_library_path)) != NULL)
1548 	    return (pathname);
1549     } else {
1550 	nodeflib = objgiven ? refobj->z_nodeflib : false;
1551 	if ((objgiven &&
1552 	  (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1553 	  (objgiven && refobj->runpath == NULL && refobj != obj_main &&
1554 	  (pathname = search_library_path(name, obj_main->rpath)) != NULL) ||
1555 	  (pathname = search_library_path(name, ld_library_path)) != NULL ||
1556 	  (objgiven &&
1557 	  (pathname = search_library_path(name, refobj->runpath)) != NULL) ||
1558 	  (pathname = search_library_pathfds(name, ld_library_dirs, fdp)) != NULL ||
1559 	  (pathname = search_library_path(name, gethints(nodeflib))) != NULL ||
1560 	  (objgiven && !nodeflib &&
1561 	  (pathname = search_library_path(name, ld_standard_library_path)) != NULL))
1562 	    return (pathname);
1563     }
1564 
1565     if (objgiven && refobj->path != NULL) {
1566 	_rtld_error("Shared object \"%s\" not found, required by \"%s\"",
1567 	  name, basename(refobj->path));
1568     } else {
1569 	_rtld_error("Shared object \"%s\" not found", name);
1570     }
1571     return NULL;
1572 }
1573 
1574 /*
1575  * Given a symbol number in a referencing object, find the corresponding
1576  * definition of the symbol.  Returns a pointer to the symbol, or NULL if
1577  * no definition was found.  Returns a pointer to the Obj_Entry of the
1578  * defining object via the reference parameter DEFOBJ_OUT.
1579  */
1580 const Elf_Sym *
1581 find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1582     const Obj_Entry **defobj_out, int flags, SymCache *cache,
1583     RtldLockState *lockstate)
1584 {
1585     const Elf_Sym *ref;
1586     const Elf_Sym *def;
1587     const Obj_Entry *defobj;
1588     SymLook req;
1589     const char *name;
1590     int res;
1591 
1592     /*
1593      * If we have already found this symbol, get the information from
1594      * the cache.
1595      */
1596     if (symnum >= refobj->dynsymcount)
1597 	return NULL;	/* Bad object */
1598     if (cache != NULL && cache[symnum].sym != NULL) {
1599 	*defobj_out = cache[symnum].obj;
1600 	return cache[symnum].sym;
1601     }
1602 
1603     ref = refobj->symtab + symnum;
1604     name = refobj->strtab + ref->st_name;
1605     def = NULL;
1606     defobj = NULL;
1607 
1608     /*
1609      * We don't have to do a full scale lookup if the symbol is local.
1610      * We know it will bind to the instance in this load module; to
1611      * which we already have a pointer (ie ref). By not doing a lookup,
1612      * we not only improve performance, but it also avoids unresolvable
1613      * symbols when local symbols are not in the hash table. This has
1614      * been seen with the ia64 toolchain.
1615      */
1616     if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1617 	if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
1618 	    _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1619 		symnum);
1620 	}
1621 	symlook_init(&req, name);
1622 	req.flags = flags;
1623 	req.ventry = fetch_ventry(refobj, symnum);
1624 	req.lockstate = lockstate;
1625 	res = symlook_default(&req, refobj);
1626 	if (res == 0) {
1627 	    def = req.sym_out;
1628 	    defobj = req.defobj_out;
1629 	}
1630     } else {
1631 	def = ref;
1632 	defobj = refobj;
1633     }
1634 
1635     /*
1636      * If we found no definition and the reference is weak, treat the
1637      * symbol as having the value zero.
1638      */
1639     if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1640 	def = &sym_zero;
1641 	defobj = obj_main;
1642     }
1643 
1644     if (def != NULL) {
1645 	*defobj_out = defobj;
1646 	/* Record the information in the cache to avoid subsequent lookups. */
1647 	if (cache != NULL) {
1648 	    cache[symnum].sym = def;
1649 	    cache[symnum].obj = defobj;
1650 	}
1651     } else {
1652 	if (refobj != &obj_rtld)
1653 	    _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1654     }
1655     return def;
1656 }
1657 
1658 /*
1659  * Return the search path from the ldconfig hints file, reading it if
1660  * necessary.  If nostdlib is true, then the default search paths are
1661  * not added to result.
1662  *
1663  * Returns NULL if there are problems with the hints file,
1664  * or if the search path there is empty.
1665  */
1666 static const char *
1667 gethints(bool nostdlib)
1668 {
1669 	static char *hints, *filtered_path;
1670 	struct elfhints_hdr hdr;
1671 	struct fill_search_info_args sargs, hargs;
1672 	struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo;
1673 	struct dl_serpath *SLPpath, *hintpath;
1674 	char *p;
1675 	unsigned int SLPndx, hintndx, fndx, fcount;
1676 	int fd;
1677 	size_t flen;
1678 	bool skip;
1679 
1680 	/* First call, read the hints file */
1681 	if (hints == NULL) {
1682 		/* Keep from trying again in case the hints file is bad. */
1683 		hints = "";
1684 
1685 		if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1)
1686 			return (NULL);
1687 		if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1688 		    hdr.magic != ELFHINTS_MAGIC ||
1689 		    hdr.version != 1) {
1690 			close(fd);
1691 			return (NULL);
1692 		}
1693 		p = xmalloc(hdr.dirlistlen + 1);
1694 		if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1695 		    read(fd, p, hdr.dirlistlen + 1) !=
1696 		    (ssize_t)hdr.dirlistlen + 1) {
1697 			free(p);
1698 			close(fd);
1699 			return (NULL);
1700 		}
1701 		hints = p;
1702 		close(fd);
1703 	}
1704 
1705 	/*
1706 	 * If caller agreed to receive list which includes the default
1707 	 * paths, we are done. Otherwise, if we still did not
1708 	 * calculated filtered result, do it now.
1709 	 */
1710 	if (!nostdlib)
1711 		return (hints[0] != '\0' ? hints : NULL);
1712 	if (filtered_path != NULL)
1713 		goto filt_ret;
1714 
1715 	/*
1716 	 * Obtain the list of all configured search paths, and the
1717 	 * list of the default paths.
1718 	 *
1719 	 * First estimate the size of the results.
1720 	 */
1721 	smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
1722 	smeta.dls_cnt = 0;
1723 	hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
1724 	hmeta.dls_cnt = 0;
1725 
1726 	sargs.request = RTLD_DI_SERINFOSIZE;
1727 	sargs.serinfo = &smeta;
1728 	hargs.request = RTLD_DI_SERINFOSIZE;
1729 	hargs.serinfo = &hmeta;
1730 
1731 	path_enumerate(ld_standard_library_path, fill_search_info, &sargs);
1732 	path_enumerate(p, fill_search_info, &hargs);
1733 
1734 	SLPinfo = xmalloc(smeta.dls_size);
1735 	hintinfo = xmalloc(hmeta.dls_size);
1736 
1737 	/*
1738 	 * Next fetch both sets of paths.
1739 	 */
1740 	sargs.request = RTLD_DI_SERINFO;
1741 	sargs.serinfo = SLPinfo;
1742 	sargs.serpath = &SLPinfo->dls_serpath[0];
1743 	sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt];
1744 
1745 	hargs.request = RTLD_DI_SERINFO;
1746 	hargs.serinfo = hintinfo;
1747 	hargs.serpath = &hintinfo->dls_serpath[0];
1748 	hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt];
1749 
1750 	path_enumerate(ld_standard_library_path, fill_search_info, &sargs);
1751 	path_enumerate(p, fill_search_info, &hargs);
1752 
1753 	/*
1754 	 * Now calculate the difference between two sets, by excluding
1755 	 * standard paths from the full set.
1756 	 */
1757 	fndx = 0;
1758 	fcount = 0;
1759 	filtered_path = xmalloc(hdr.dirlistlen + 1);
1760 	hintpath = &hintinfo->dls_serpath[0];
1761 	for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) {
1762 		skip = false;
1763 		SLPpath = &SLPinfo->dls_serpath[0];
1764 		/*
1765 		 * Check each standard path against current.
1766 		 */
1767 		for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) {
1768 			/* matched, skip the path */
1769 			if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) {
1770 				skip = true;
1771 				break;
1772 			}
1773 		}
1774 		if (skip)
1775 			continue;
1776 		/*
1777 		 * Not matched against any standard path, add the path
1778 		 * to result. Separate consequtive paths with ':'.
1779 		 */
1780 		if (fcount > 0) {
1781 			filtered_path[fndx] = ':';
1782 			fndx++;
1783 		}
1784 		fcount++;
1785 		flen = strlen(hintpath->dls_name);
1786 		strncpy((filtered_path + fndx),	hintpath->dls_name, flen);
1787 		fndx += flen;
1788 	}
1789 	filtered_path[fndx] = '\0';
1790 
1791 	free(SLPinfo);
1792 	free(hintinfo);
1793 
1794 filt_ret:
1795 	return (filtered_path[0] != '\0' ? filtered_path : NULL);
1796 }
1797 
1798 static void
1799 init_dag(Obj_Entry *root)
1800 {
1801     const Needed_Entry *needed;
1802     const Objlist_Entry *elm;
1803     DoneList donelist;
1804 
1805     if (root->dag_inited)
1806 	return;
1807     donelist_init(&donelist);
1808 
1809     /* Root object belongs to own DAG. */
1810     objlist_push_tail(&root->dldags, root);
1811     objlist_push_tail(&root->dagmembers, root);
1812     donelist_check(&donelist, root);
1813 
1814     /*
1815      * Add dependencies of root object to DAG in breadth order
1816      * by exploiting the fact that each new object get added
1817      * to the tail of the dagmembers list.
1818      */
1819     STAILQ_FOREACH(elm, &root->dagmembers, link) {
1820 	for (needed = elm->obj->needed; needed != NULL; needed = needed->next) {
1821 	    if (needed->obj == NULL || donelist_check(&donelist, needed->obj))
1822 		continue;
1823 	    objlist_push_tail(&needed->obj->dldags, root);
1824 	    objlist_push_tail(&root->dagmembers, needed->obj);
1825 	}
1826     }
1827     root->dag_inited = true;
1828 }
1829 
1830 Obj_Entry *
1831 globallist_curr(const Obj_Entry *obj)
1832 {
1833 
1834 	for (;;) {
1835 		if (obj == NULL)
1836 			return (NULL);
1837 		if (!obj->marker)
1838 			return (__DECONST(Obj_Entry *, obj));
1839 		obj = TAILQ_PREV(obj, obj_entry_q, next);
1840 	}
1841 }
1842 
1843 Obj_Entry *
1844 globallist_next(const Obj_Entry *obj)
1845 {
1846 
1847 	for (;;) {
1848 		obj = TAILQ_NEXT(obj, next);
1849 		if (obj == NULL)
1850 			return (NULL);
1851 		if (!obj->marker)
1852 			return (__DECONST(Obj_Entry *, obj));
1853 	}
1854 }
1855 
1856 static void
1857 process_z(Obj_Entry *root)
1858 {
1859 	const Objlist_Entry *elm;
1860 	Obj_Entry *obj;
1861 
1862 	/*
1863 	 * Walk over object DAG and process every dependent object
1864 	 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need
1865 	 * to grow their own DAG.
1866 	 *
1867 	 * For DF_1_GLOBAL, DAG is required for symbol lookups in
1868 	 * symlook_global() to work.
1869 	 *
1870 	 * For DF_1_NODELETE, the DAG should have its reference upped.
1871 	 */
1872 	STAILQ_FOREACH(elm, &root->dagmembers, link) {
1873 		obj = elm->obj;
1874 		if (obj == NULL)
1875 			continue;
1876 		if (obj->z_nodelete && !obj->ref_nodel) {
1877 			dbg("obj %s -z nodelete", obj->path);
1878 			init_dag(obj);
1879 			ref_dag(obj);
1880 			obj->ref_nodel = true;
1881 		}
1882 		if (obj->z_global && objlist_find(&list_global, obj) == NULL) {
1883 			dbg("obj %s -z global", obj->path);
1884 			objlist_push_tail(&list_global, obj);
1885 			init_dag(obj);
1886 		}
1887 	}
1888 }
1889 /*
1890  * Initialize the dynamic linker.  The argument is the address at which
1891  * the dynamic linker has been mapped into memory.  The primary task of
1892  * this function is to relocate the dynamic linker.
1893  */
1894 static void
1895 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
1896 {
1897     Obj_Entry objtmp;	/* Temporary rtld object */
1898     const Elf_Dyn *dyn_rpath;
1899     const Elf_Dyn *dyn_soname;
1900     const Elf_Dyn *dyn_runpath;
1901 
1902 #ifdef RTLD_INIT_PAGESIZES_EARLY
1903     /* The page size is required by the dynamic memory allocator. */
1904     init_pagesizes(aux_info);
1905 #endif
1906 
1907     /*
1908      * Conjure up an Obj_Entry structure for the dynamic linker.
1909      *
1910      * The "path" member can't be initialized yet because string constants
1911      * cannot yet be accessed. Below we will set it correctly.
1912      */
1913     memset(&objtmp, 0, sizeof(objtmp));
1914     objtmp.path = NULL;
1915     objtmp.rtld = true;
1916     objtmp.mapbase = mapbase;
1917 #ifdef PIC
1918     objtmp.relocbase = mapbase;
1919 #endif
1920     if (RTLD_IS_DYNAMIC()) {
1921 	objtmp.dynamic = rtld_dynamic(&objtmp);
1922 	digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath);
1923 	assert(objtmp.needed == NULL);
1924 #if !defined(__mips__)
1925 	/* MIPS has a bogus DT_TEXTREL. */
1926 	assert(!objtmp.textrel);
1927 #endif
1928 
1929 	/*
1930 	 * Temporarily put the dynamic linker entry into the object list, so
1931 	 * that symbols can be found.
1932 	 */
1933 
1934 	relocate_objects(&objtmp, true, &objtmp, 0, NULL);
1935     }
1936 
1937     /* Initialize the object list. */
1938     TAILQ_INIT(&obj_list);
1939 
1940     /* Now that non-local variables can be accesses, copy out obj_rtld. */
1941     memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
1942 
1943 #ifndef RTLD_INIT_PAGESIZES_EARLY
1944     /* The page size is required by the dynamic memory allocator. */
1945     init_pagesizes(aux_info);
1946 #endif
1947 
1948     if (aux_info[AT_OSRELDATE] != NULL)
1949 	    osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
1950 
1951     digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath);
1952 
1953     /* Replace the path with a dynamically allocated copy. */
1954     obj_rtld.path = xstrdup(ld_path_rtld);
1955 
1956     r_debug.r_brk = r_debug_state;
1957     r_debug.r_state = RT_CONSISTENT;
1958 }
1959 
1960 /*
1961  * Retrieve the array of supported page sizes.  The kernel provides the page
1962  * sizes in increasing order.
1963  */
1964 static void
1965 init_pagesizes(Elf_Auxinfo **aux_info)
1966 {
1967 	static size_t psa[MAXPAGESIZES];
1968 	int mib[2];
1969 	size_t len, size;
1970 
1971 	if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] !=
1972 	    NULL) {
1973 		size = aux_info[AT_PAGESIZESLEN]->a_un.a_val;
1974 		pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr;
1975 	} else {
1976 		len = 2;
1977 		if (sysctlnametomib("hw.pagesizes", mib, &len) == 0)
1978 			size = sizeof(psa);
1979 		else {
1980 			/* As a fallback, retrieve the base page size. */
1981 			size = sizeof(psa[0]);
1982 			if (aux_info[AT_PAGESZ] != NULL) {
1983 				psa[0] = aux_info[AT_PAGESZ]->a_un.a_val;
1984 				goto psa_filled;
1985 			} else {
1986 				mib[0] = CTL_HW;
1987 				mib[1] = HW_PAGESIZE;
1988 				len = 2;
1989 			}
1990 		}
1991 		if (sysctl(mib, len, psa, &size, NULL, 0) == -1) {
1992 			_rtld_error("sysctl for hw.pagesize(s) failed");
1993 			rtld_die();
1994 		}
1995 psa_filled:
1996 		pagesizes = psa;
1997 	}
1998 	npagesizes = size / sizeof(pagesizes[0]);
1999 	/* Discard any invalid entries at the end of the array. */
2000 	while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0)
2001 		npagesizes--;
2002 }
2003 
2004 /*
2005  * Add the init functions from a needed object list (and its recursive
2006  * needed objects) to "list".  This is not used directly; it is a helper
2007  * function for initlist_add_objects().  The write lock must be held
2008  * when this function is called.
2009  */
2010 static void
2011 initlist_add_neededs(Needed_Entry *needed, Objlist *list)
2012 {
2013     /* Recursively process the successor needed objects. */
2014     if (needed->next != NULL)
2015 	initlist_add_neededs(needed->next, list);
2016 
2017     /* Process the current needed object. */
2018     if (needed->obj != NULL)
2019 	initlist_add_objects(needed->obj, needed->obj, list);
2020 }
2021 
2022 /*
2023  * Scan all of the DAGs rooted in the range of objects from "obj" to
2024  * "tail" and add their init functions to "list".  This recurses over
2025  * the DAGs and ensure the proper init ordering such that each object's
2026  * needed libraries are initialized before the object itself.  At the
2027  * same time, this function adds the objects to the global finalization
2028  * list "list_fini" in the opposite order.  The write lock must be
2029  * held when this function is called.
2030  */
2031 static void
2032 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list)
2033 {
2034     Obj_Entry *nobj;
2035 
2036     if (obj->init_scanned || obj->init_done)
2037 	return;
2038     obj->init_scanned = true;
2039 
2040     /* Recursively process the successor objects. */
2041     nobj = globallist_next(obj);
2042     if (nobj != NULL && obj != tail)
2043 	initlist_add_objects(nobj, tail, list);
2044 
2045     /* Recursively process the needed objects. */
2046     if (obj->needed != NULL)
2047 	initlist_add_neededs(obj->needed, list);
2048     if (obj->needed_filtees != NULL)
2049 	initlist_add_neededs(obj->needed_filtees, list);
2050     if (obj->needed_aux_filtees != NULL)
2051 	initlist_add_neededs(obj->needed_aux_filtees, list);
2052 
2053     /* Add the object to the init list. */
2054     if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL ||
2055       obj->init_array != (Elf_Addr)NULL)
2056 	objlist_push_tail(list, obj);
2057 
2058     /* Add the object to the global fini list in the reverse order. */
2059     if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL)
2060       && !obj->on_fini_list) {
2061 	objlist_push_head(&list_fini, obj);
2062 	obj->on_fini_list = true;
2063     }
2064 }
2065 
2066 #ifndef FPTR_TARGET
2067 #define FPTR_TARGET(f)	((Elf_Addr) (f))
2068 #endif
2069 
2070 static void
2071 free_needed_filtees(Needed_Entry *n)
2072 {
2073     Needed_Entry *needed, *needed1;
2074 
2075     for (needed = n; needed != NULL; needed = needed->next) {
2076 	if (needed->obj != NULL) {
2077 	    dlclose(needed->obj);
2078 	    needed->obj = NULL;
2079 	}
2080     }
2081     for (needed = n; needed != NULL; needed = needed1) {
2082 	needed1 = needed->next;
2083 	free(needed);
2084     }
2085 }
2086 
2087 static void
2088 unload_filtees(Obj_Entry *obj)
2089 {
2090 
2091     free_needed_filtees(obj->needed_filtees);
2092     obj->needed_filtees = NULL;
2093     free_needed_filtees(obj->needed_aux_filtees);
2094     obj->needed_aux_filtees = NULL;
2095     obj->filtees_loaded = false;
2096 }
2097 
2098 static void
2099 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags,
2100     RtldLockState *lockstate)
2101 {
2102 
2103     for (; needed != NULL; needed = needed->next) {
2104 	needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj,
2105 	  flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) |
2106 	  RTLD_LOCAL, lockstate);
2107     }
2108 }
2109 
2110 static void
2111 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate)
2112 {
2113 
2114     lock_restart_for_upgrade(lockstate);
2115     if (!obj->filtees_loaded) {
2116 	load_filtee1(obj, obj->needed_filtees, flags, lockstate);
2117 	load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate);
2118 	obj->filtees_loaded = true;
2119     }
2120 }
2121 
2122 static int
2123 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags)
2124 {
2125     Obj_Entry *obj1;
2126 
2127     for (; needed != NULL; needed = needed->next) {
2128 	obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj,
2129 	  flags & ~RTLD_LO_NOLOAD);
2130 	if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0)
2131 	    return (-1);
2132     }
2133     return (0);
2134 }
2135 
2136 /*
2137  * Given a shared object, traverse its list of needed objects, and load
2138  * each of them.  Returns 0 on success.  Generates an error message and
2139  * returns -1 on failure.
2140  */
2141 static int
2142 load_needed_objects(Obj_Entry *first, int flags)
2143 {
2144     Obj_Entry *obj;
2145 
2146     obj = first;
2147     TAILQ_FOREACH_FROM(obj, &obj_list, next) {
2148 	if (obj->marker)
2149 	    continue;
2150 	if (process_needed(obj, obj->needed, flags) == -1)
2151 	    return (-1);
2152     }
2153     return (0);
2154 }
2155 
2156 static int
2157 load_preload_objects(void)
2158 {
2159     char *p = ld_preload;
2160     Obj_Entry *obj;
2161     static const char delim[] = " \t:;";
2162 
2163     if (p == NULL)
2164 	return 0;
2165 
2166     p += strspn(p, delim);
2167     while (*p != '\0') {
2168 	size_t len = strcspn(p, delim);
2169 	char savech;
2170 
2171 	savech = p[len];
2172 	p[len] = '\0';
2173 	obj = load_object(p, -1, NULL, 0);
2174 	if (obj == NULL)
2175 	    return -1;	/* XXX - cleanup */
2176 	obj->z_interpose = true;
2177 	p[len] = savech;
2178 	p += len;
2179 	p += strspn(p, delim);
2180     }
2181     LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
2182     return 0;
2183 }
2184 
2185 static const char *
2186 printable_path(const char *path)
2187 {
2188 
2189 	return (path == NULL ? "<unknown>" : path);
2190 }
2191 
2192 /*
2193  * Load a shared object into memory, if it is not already loaded.  The
2194  * object may be specified by name or by user-supplied file descriptor
2195  * fd_u. In the later case, the fd_u descriptor is not closed, but its
2196  * duplicate is.
2197  *
2198  * Returns a pointer to the Obj_Entry for the object.  Returns NULL
2199  * on failure.
2200  */
2201 static Obj_Entry *
2202 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags)
2203 {
2204     Obj_Entry *obj;
2205     int fd;
2206     struct stat sb;
2207     char *path;
2208 
2209     fd = -1;
2210     if (name != NULL) {
2211 	TAILQ_FOREACH(obj, &obj_list, next) {
2212 	    if (obj->marker)
2213 		continue;
2214 	    if (object_match_name(obj, name))
2215 		return (obj);
2216 	}
2217 
2218 	path = find_library(name, refobj, &fd);
2219 	if (path == NULL)
2220 	    return (NULL);
2221     } else
2222 	path = NULL;
2223 
2224     if (fd >= 0) {
2225 	/*
2226 	 * search_library_pathfds() opens a fresh file descriptor for the
2227 	 * library, so there is no need to dup().
2228 	 */
2229     } else if (fd_u == -1) {
2230 	/*
2231 	 * If we didn't find a match by pathname, or the name is not
2232 	 * supplied, open the file and check again by device and inode.
2233 	 * This avoids false mismatches caused by multiple links or ".."
2234 	 * in pathnames.
2235 	 *
2236 	 * To avoid a race, we open the file and use fstat() rather than
2237 	 * using stat().
2238 	 */
2239 	if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) {
2240 	    _rtld_error("Cannot open \"%s\"", path);
2241 	    free(path);
2242 	    return (NULL);
2243 	}
2244     } else {
2245 	fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0);
2246 	if (fd == -1) {
2247 	    _rtld_error("Cannot dup fd");
2248 	    free(path);
2249 	    return (NULL);
2250 	}
2251     }
2252     if (fstat(fd, &sb) == -1) {
2253 	_rtld_error("Cannot fstat \"%s\"", printable_path(path));
2254 	close(fd);
2255 	free(path);
2256 	return NULL;
2257     }
2258     TAILQ_FOREACH(obj, &obj_list, next) {
2259 	if (obj->marker)
2260 	    continue;
2261 	if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
2262 	    break;
2263     }
2264     if (obj != NULL && name != NULL) {
2265 	object_add_name(obj, name);
2266 	free(path);
2267 	close(fd);
2268 	return obj;
2269     }
2270     if (flags & RTLD_LO_NOLOAD) {
2271 	free(path);
2272 	close(fd);
2273 	return (NULL);
2274     }
2275 
2276     /* First use of this object, so we must map it in */
2277     obj = do_load_object(fd, name, path, &sb, flags);
2278     if (obj == NULL)
2279 	free(path);
2280     close(fd);
2281 
2282     return obj;
2283 }
2284 
2285 static Obj_Entry *
2286 do_load_object(int fd, const char *name, char *path, struct stat *sbp,
2287   int flags)
2288 {
2289     Obj_Entry *obj;
2290     struct statfs fs;
2291 
2292     /*
2293      * but first, make sure that environment variables haven't been
2294      * used to circumvent the noexec flag on a filesystem.
2295      */
2296     if (dangerous_ld_env) {
2297 	if (fstatfs(fd, &fs) != 0) {
2298 	    _rtld_error("Cannot fstatfs \"%s\"", printable_path(path));
2299 	    return NULL;
2300 	}
2301 	if (fs.f_flags & MNT_NOEXEC) {
2302 	    _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
2303 	    return NULL;
2304 	}
2305     }
2306     dbg("loading \"%s\"", printable_path(path));
2307     obj = map_object(fd, printable_path(path), sbp);
2308     if (obj == NULL)
2309         return NULL;
2310 
2311     /*
2312      * If DT_SONAME is present in the object, digest_dynamic2 already
2313      * added it to the object names.
2314      */
2315     if (name != NULL)
2316 	object_add_name(obj, name);
2317     obj->path = path;
2318     digest_dynamic(obj, 0);
2319     dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path,
2320 	obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount);
2321     if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
2322       RTLD_LO_DLOPEN) {
2323 	dbg("refusing to load non-loadable \"%s\"", obj->path);
2324 	_rtld_error("Cannot dlopen non-loadable %s", obj->path);
2325 	munmap(obj->mapbase, obj->mapsize);
2326 	obj_free(obj);
2327 	return (NULL);
2328     }
2329 
2330     obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0;
2331     TAILQ_INSERT_TAIL(&obj_list, obj, next);
2332     obj_count++;
2333     obj_loads++;
2334     linkmap_add(obj);	/* for GDB & dlinfo() */
2335     max_stack_flags |= obj->stack_flags;
2336 
2337     dbg("  %p .. %p: %s", obj->mapbase,
2338          obj->mapbase + obj->mapsize - 1, obj->path);
2339     if (obj->textrel)
2340 	dbg("  WARNING: %s has impure text", obj->path);
2341     LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
2342 	obj->path);
2343 
2344     return obj;
2345 }
2346 
2347 static Obj_Entry *
2348 obj_from_addr(const void *addr)
2349 {
2350     Obj_Entry *obj;
2351 
2352     TAILQ_FOREACH(obj, &obj_list, next) {
2353 	if (obj->marker)
2354 	    continue;
2355 	if (addr < (void *) obj->mapbase)
2356 	    continue;
2357 	if (addr < (void *) (obj->mapbase + obj->mapsize))
2358 	    return obj;
2359     }
2360     return NULL;
2361 }
2362 
2363 static void
2364 preinit_main(void)
2365 {
2366     Elf_Addr *preinit_addr;
2367     int index;
2368 
2369     preinit_addr = (Elf_Addr *)obj_main->preinit_array;
2370     if (preinit_addr == NULL)
2371 	return;
2372 
2373     for (index = 0; index < obj_main->preinit_array_num; index++) {
2374 	if (preinit_addr[index] != 0 && preinit_addr[index] != 1) {
2375 	    dbg("calling preinit function for %s at %p", obj_main->path,
2376 	      (void *)preinit_addr[index]);
2377 	    LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index],
2378 	      0, 0, obj_main->path);
2379 	    call_init_pointer(obj_main, preinit_addr[index]);
2380 	}
2381     }
2382 }
2383 
2384 /*
2385  * Call the finalization functions for each of the objects in "list"
2386  * belonging to the DAG of "root" and referenced once. If NULL "root"
2387  * is specified, every finalization function will be called regardless
2388  * of the reference count and the list elements won't be freed. All of
2389  * the objects are expected to have non-NULL fini functions.
2390  */
2391 static void
2392 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
2393 {
2394     Objlist_Entry *elm;
2395     char *saved_msg;
2396     Elf_Addr *fini_addr;
2397     int index;
2398 
2399     assert(root == NULL || root->refcount == 1);
2400 
2401     /*
2402      * Preserve the current error message since a fini function might
2403      * call into the dynamic linker and overwrite it.
2404      */
2405     saved_msg = errmsg_save();
2406     do {
2407 	STAILQ_FOREACH(elm, list, link) {
2408 	    if (root != NULL && (elm->obj->refcount != 1 ||
2409 	      objlist_find(&root->dagmembers, elm->obj) == NULL))
2410 		continue;
2411 	    /* Remove object from fini list to prevent recursive invocation. */
2412 	    STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2413 	    /*
2414 	     * XXX: If a dlopen() call references an object while the
2415 	     * fini function is in progress, we might end up trying to
2416 	     * unload the referenced object in dlclose() or the object
2417 	     * won't be unloaded although its fini function has been
2418 	     * called.
2419 	     */
2420 	    lock_release(rtld_bind_lock, lockstate);
2421 
2422 	    /*
2423 	     * It is legal to have both DT_FINI and DT_FINI_ARRAY defined.
2424 	     * When this happens, DT_FINI_ARRAY is processed first.
2425 	     */
2426 	    fini_addr = (Elf_Addr *)elm->obj->fini_array;
2427 	    if (fini_addr != NULL && elm->obj->fini_array_num > 0) {
2428 		for (index = elm->obj->fini_array_num - 1; index >= 0;
2429 		  index--) {
2430 		    if (fini_addr[index] != 0 && fini_addr[index] != 1) {
2431 			dbg("calling fini function for %s at %p",
2432 			    elm->obj->path, (void *)fini_addr[index]);
2433 			LD_UTRACE(UTRACE_FINI_CALL, elm->obj,
2434 			    (void *)fini_addr[index], 0, 0, elm->obj->path);
2435 			call_initfini_pointer(elm->obj, fini_addr[index]);
2436 		    }
2437 		}
2438 	    }
2439 	    if (elm->obj->fini != (Elf_Addr)NULL) {
2440 		dbg("calling fini function for %s at %p", elm->obj->path,
2441 		    (void *)elm->obj->fini);
2442 		LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini,
2443 		    0, 0, elm->obj->path);
2444 		call_initfini_pointer(elm->obj, elm->obj->fini);
2445 	    }
2446 	    wlock_acquire(rtld_bind_lock, lockstate);
2447 	    /* No need to free anything if process is going down. */
2448 	    if (root != NULL)
2449 	    	free(elm);
2450 	    /*
2451 	     * We must restart the list traversal after every fini call
2452 	     * because a dlclose() call from the fini function or from
2453 	     * another thread might have modified the reference counts.
2454 	     */
2455 	    break;
2456 	}
2457     } while (elm != NULL);
2458     errmsg_restore(saved_msg);
2459 }
2460 
2461 /*
2462  * Call the initialization functions for each of the objects in
2463  * "list".  All of the objects are expected to have non-NULL init
2464  * functions.
2465  */
2466 static void
2467 objlist_call_init(Objlist *list, RtldLockState *lockstate)
2468 {
2469     Objlist_Entry *elm;
2470     Obj_Entry *obj;
2471     char *saved_msg;
2472     Elf_Addr *init_addr;
2473     int index;
2474 
2475     /*
2476      * Clean init_scanned flag so that objects can be rechecked and
2477      * possibly initialized earlier if any of vectors called below
2478      * cause the change by using dlopen.
2479      */
2480     TAILQ_FOREACH(obj, &obj_list, next) {
2481 	if (obj->marker)
2482 	    continue;
2483 	obj->init_scanned = false;
2484     }
2485 
2486     /*
2487      * Preserve the current error message since an init function might
2488      * call into the dynamic linker and overwrite it.
2489      */
2490     saved_msg = errmsg_save();
2491     STAILQ_FOREACH(elm, list, link) {
2492 	if (elm->obj->init_done) /* Initialized early. */
2493 	    continue;
2494 	/*
2495 	 * Race: other thread might try to use this object before current
2496 	 * one completes the initilization. Not much can be done here
2497 	 * without better locking.
2498 	 */
2499 	elm->obj->init_done = true;
2500 	lock_release(rtld_bind_lock, lockstate);
2501 
2502         /*
2503          * It is legal to have both DT_INIT and DT_INIT_ARRAY defined.
2504          * When this happens, DT_INIT is processed first.
2505          */
2506 	if (elm->obj->init != (Elf_Addr)NULL) {
2507 	    dbg("calling init function for %s at %p", elm->obj->path,
2508 	        (void *)elm->obj->init);
2509 	    LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init,
2510 	        0, 0, elm->obj->path);
2511 	    call_initfini_pointer(elm->obj, elm->obj->init);
2512 	}
2513 	init_addr = (Elf_Addr *)elm->obj->init_array;
2514 	if (init_addr != NULL) {
2515 	    for (index = 0; index < elm->obj->init_array_num; index++) {
2516 		if (init_addr[index] != 0 && init_addr[index] != 1) {
2517 		    dbg("calling init function for %s at %p", elm->obj->path,
2518 			(void *)init_addr[index]);
2519 		    LD_UTRACE(UTRACE_INIT_CALL, elm->obj,
2520 			(void *)init_addr[index], 0, 0, elm->obj->path);
2521 		    call_init_pointer(elm->obj, init_addr[index]);
2522 		}
2523 	    }
2524 	}
2525 	wlock_acquire(rtld_bind_lock, lockstate);
2526     }
2527     errmsg_restore(saved_msg);
2528 }
2529 
2530 static void
2531 objlist_clear(Objlist *list)
2532 {
2533     Objlist_Entry *elm;
2534 
2535     while (!STAILQ_EMPTY(list)) {
2536 	elm = STAILQ_FIRST(list);
2537 	STAILQ_REMOVE_HEAD(list, link);
2538 	free(elm);
2539     }
2540 }
2541 
2542 static Objlist_Entry *
2543 objlist_find(Objlist *list, const Obj_Entry *obj)
2544 {
2545     Objlist_Entry *elm;
2546 
2547     STAILQ_FOREACH(elm, list, link)
2548 	if (elm->obj == obj)
2549 	    return elm;
2550     return NULL;
2551 }
2552 
2553 static void
2554 objlist_init(Objlist *list)
2555 {
2556     STAILQ_INIT(list);
2557 }
2558 
2559 static void
2560 objlist_push_head(Objlist *list, Obj_Entry *obj)
2561 {
2562     Objlist_Entry *elm;
2563 
2564     elm = NEW(Objlist_Entry);
2565     elm->obj = obj;
2566     STAILQ_INSERT_HEAD(list, elm, link);
2567 }
2568 
2569 static void
2570 objlist_push_tail(Objlist *list, Obj_Entry *obj)
2571 {
2572     Objlist_Entry *elm;
2573 
2574     elm = NEW(Objlist_Entry);
2575     elm->obj = obj;
2576     STAILQ_INSERT_TAIL(list, elm, link);
2577 }
2578 
2579 static void
2580 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj)
2581 {
2582 	Objlist_Entry *elm, *listelm;
2583 
2584 	STAILQ_FOREACH(listelm, list, link) {
2585 		if (listelm->obj == listobj)
2586 			break;
2587 	}
2588 	elm = NEW(Objlist_Entry);
2589 	elm->obj = obj;
2590 	if (listelm != NULL)
2591 		STAILQ_INSERT_AFTER(list, listelm, elm, link);
2592 	else
2593 		STAILQ_INSERT_TAIL(list, elm, link);
2594 }
2595 
2596 static void
2597 objlist_remove(Objlist *list, Obj_Entry *obj)
2598 {
2599     Objlist_Entry *elm;
2600 
2601     if ((elm = objlist_find(list, obj)) != NULL) {
2602 	STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2603 	free(elm);
2604     }
2605 }
2606 
2607 /*
2608  * Relocate dag rooted in the specified object.
2609  * Returns 0 on success, or -1 on failure.
2610  */
2611 
2612 static int
2613 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj,
2614     int flags, RtldLockState *lockstate)
2615 {
2616 	Objlist_Entry *elm;
2617 	int error;
2618 
2619 	error = 0;
2620 	STAILQ_FOREACH(elm, &root->dagmembers, link) {
2621 		error = relocate_object(elm->obj, bind_now, rtldobj, flags,
2622 		    lockstate);
2623 		if (error == -1)
2624 			break;
2625 	}
2626 	return (error);
2627 }
2628 
2629 /*
2630  * Prepare for, or clean after, relocating an object marked with
2631  * DT_TEXTREL or DF_TEXTREL.  Before relocating, all read-only
2632  * segments are remapped read-write.  After relocations are done, the
2633  * segment's permissions are returned back to the modes specified in
2634  * the phdrs.  If any relocation happened, or always for wired
2635  * program, COW is triggered.
2636  */
2637 static int
2638 reloc_textrel_prot(Obj_Entry *obj, bool before)
2639 {
2640 	const Elf_Phdr *ph;
2641 	void *base;
2642 	size_t l, sz;
2643 	int prot;
2644 
2645 	for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0;
2646 	    l--, ph++) {
2647 		if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0)
2648 			continue;
2649 		base = obj->relocbase + trunc_page(ph->p_vaddr);
2650 		sz = round_page(ph->p_vaddr + ph->p_filesz) -
2651 		    trunc_page(ph->p_vaddr);
2652 		prot = convert_prot(ph->p_flags) | (before ? PROT_WRITE : 0);
2653 		if (mprotect(base, sz, prot) == -1) {
2654 			_rtld_error("%s: Cannot write-%sable text segment: %s",
2655 			    obj->path, before ? "en" : "dis",
2656 			    rtld_strerror(errno));
2657 			return (-1);
2658 		}
2659 	}
2660 	return (0);
2661 }
2662 
2663 /*
2664  * Relocate single object.
2665  * Returns 0 on success, or -1 on failure.
2666  */
2667 static int
2668 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
2669     int flags, RtldLockState *lockstate)
2670 {
2671 
2672 	if (obj->relocated)
2673 		return (0);
2674 	obj->relocated = true;
2675 	if (obj != rtldobj)
2676 		dbg("relocating \"%s\"", obj->path);
2677 
2678 	if (obj->symtab == NULL || obj->strtab == NULL ||
2679 	    !(obj->valid_hash_sysv || obj->valid_hash_gnu)) {
2680 		_rtld_error("%s: Shared object has no run-time symbol table",
2681 			    obj->path);
2682 		return (-1);
2683 	}
2684 
2685 	/* There are relocations to the write-protected text segment. */
2686 	if (obj->textrel && reloc_textrel_prot(obj, true) != 0)
2687 		return (-1);
2688 
2689 	/* Process the non-PLT non-IFUNC relocations. */
2690 	if (reloc_non_plt(obj, rtldobj, flags, lockstate))
2691 		return (-1);
2692 
2693 	/* Re-protected the text segment. */
2694 	if (obj->textrel && reloc_textrel_prot(obj, false) != 0)
2695 		return (-1);
2696 
2697 	/* Set the special PLT or GOT entries. */
2698 	init_pltgot(obj);
2699 
2700 	/* Process the PLT relocations. */
2701 	if (reloc_plt(obj) == -1)
2702 		return (-1);
2703 	/* Relocate the jump slots if we are doing immediate binding. */
2704 	if (obj->bind_now || bind_now)
2705 		if (reloc_jmpslots(obj, flags, lockstate) == -1)
2706 			return (-1);
2707 
2708 	/*
2709 	 * Process the non-PLT IFUNC relocations.  The relocations are
2710 	 * processed in two phases, because IFUNC resolvers may
2711 	 * reference other symbols, which must be readily processed
2712 	 * before resolvers are called.
2713 	 */
2714 	if (obj->non_plt_gnu_ifunc &&
2715 	    reloc_non_plt(obj, rtldobj, flags | SYMLOOK_IFUNC, lockstate))
2716 		return (-1);
2717 
2718 	if (obj->relro_size > 0) {
2719 		if (mprotect(obj->relro_page, obj->relro_size,
2720 		    PROT_READ) == -1) {
2721 			_rtld_error("%s: Cannot enforce relro protection: %s",
2722 			    obj->path, rtld_strerror(errno));
2723 			return (-1);
2724 		}
2725 	}
2726 
2727 	/*
2728 	 * Set up the magic number and version in the Obj_Entry.  These
2729 	 * were checked in the crt1.o from the original ElfKit, so we
2730 	 * set them for backward compatibility.
2731 	 */
2732 	obj->magic = RTLD_MAGIC;
2733 	obj->version = RTLD_VERSION;
2734 
2735 	return (0);
2736 }
2737 
2738 /*
2739  * Relocate newly-loaded shared objects.  The argument is a pointer to
2740  * the Obj_Entry for the first such object.  All objects from the first
2741  * to the end of the list of objects are relocated.  Returns 0 on success,
2742  * or -1 on failure.
2743  */
2744 static int
2745 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
2746     int flags, RtldLockState *lockstate)
2747 {
2748 	Obj_Entry *obj;
2749 	int error;
2750 
2751 	error = 0;
2752 	obj = first;
2753 	TAILQ_FOREACH_FROM(obj, &obj_list, next) {
2754 		if (obj->marker)
2755 			continue;
2756 		error = relocate_object(obj, bind_now, rtldobj, flags,
2757 		    lockstate);
2758 		if (error == -1)
2759 			break;
2760 	}
2761 	return (error);
2762 }
2763 
2764 /*
2765  * The handling of R_MACHINE_IRELATIVE relocations and jumpslots
2766  * referencing STT_GNU_IFUNC symbols is postponed till the other
2767  * relocations are done.  The indirect functions specified as
2768  * ifunc are allowed to call other symbols, so we need to have
2769  * objects relocated before asking for resolution from indirects.
2770  *
2771  * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion,
2772  * instead of the usual lazy handling of PLT slots.  It is
2773  * consistent with how GNU does it.
2774  */
2775 static int
2776 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags,
2777     RtldLockState *lockstate)
2778 {
2779 	if (obj->irelative && reloc_iresolve(obj, lockstate) == -1)
2780 		return (-1);
2781 	if ((obj->bind_now || bind_now) && obj->gnu_ifunc &&
2782 	    reloc_gnu_ifunc(obj, flags, lockstate) == -1)
2783 		return (-1);
2784 	return (0);
2785 }
2786 
2787 static int
2788 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags,
2789     RtldLockState *lockstate)
2790 {
2791 	Obj_Entry *obj;
2792 
2793 	obj = first;
2794 	TAILQ_FOREACH_FROM(obj, &obj_list, next) {
2795 		if (obj->marker)
2796 			continue;
2797 		if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1)
2798 			return (-1);
2799 	}
2800 	return (0);
2801 }
2802 
2803 static int
2804 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags,
2805     RtldLockState *lockstate)
2806 {
2807 	Objlist_Entry *elm;
2808 
2809 	STAILQ_FOREACH(elm, list, link) {
2810 		if (resolve_object_ifunc(elm->obj, bind_now, flags,
2811 		    lockstate) == -1)
2812 			return (-1);
2813 	}
2814 	return (0);
2815 }
2816 
2817 /*
2818  * Cleanup procedure.  It will be called (by the atexit mechanism) just
2819  * before the process exits.
2820  */
2821 static void
2822 rtld_exit(void)
2823 {
2824     RtldLockState lockstate;
2825 
2826     wlock_acquire(rtld_bind_lock, &lockstate);
2827     dbg("rtld_exit()");
2828     objlist_call_fini(&list_fini, NULL, &lockstate);
2829     /* No need to remove the items from the list, since we are exiting. */
2830     if (!libmap_disable)
2831         lm_fini();
2832     lock_release(rtld_bind_lock, &lockstate);
2833 }
2834 
2835 /*
2836  * Iterate over a search path, translate each element, and invoke the
2837  * callback on the result.
2838  */
2839 static void *
2840 path_enumerate(const char *path, path_enum_proc callback, void *arg)
2841 {
2842     const char *trans;
2843     if (path == NULL)
2844 	return (NULL);
2845 
2846     path += strspn(path, ":;");
2847     while (*path != '\0') {
2848 	size_t len;
2849 	char  *res;
2850 
2851 	len = strcspn(path, ":;");
2852 	trans = lm_findn(NULL, path, len);
2853 	if (trans)
2854 	    res = callback(trans, strlen(trans), arg);
2855 	else
2856 	    res = callback(path, len, arg);
2857 
2858 	if (res != NULL)
2859 	    return (res);
2860 
2861 	path += len;
2862 	path += strspn(path, ":;");
2863     }
2864 
2865     return (NULL);
2866 }
2867 
2868 struct try_library_args {
2869     const char	*name;
2870     size_t	 namelen;
2871     char	*buffer;
2872     size_t	 buflen;
2873 };
2874 
2875 static void *
2876 try_library_path(const char *dir, size_t dirlen, void *param)
2877 {
2878     struct try_library_args *arg;
2879 
2880     arg = param;
2881     if (*dir == '/' || trust) {
2882 	char *pathname;
2883 
2884 	if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
2885 		return (NULL);
2886 
2887 	pathname = arg->buffer;
2888 	strncpy(pathname, dir, dirlen);
2889 	pathname[dirlen] = '/';
2890 	strcpy(pathname + dirlen + 1, arg->name);
2891 
2892 	dbg("  Trying \"%s\"", pathname);
2893 	if (access(pathname, F_OK) == 0) {		/* We found it */
2894 	    pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
2895 	    strcpy(pathname, arg->buffer);
2896 	    return (pathname);
2897 	}
2898     }
2899     return (NULL);
2900 }
2901 
2902 static char *
2903 search_library_path(const char *name, const char *path)
2904 {
2905     char *p;
2906     struct try_library_args arg;
2907 
2908     if (path == NULL)
2909 	return NULL;
2910 
2911     arg.name = name;
2912     arg.namelen = strlen(name);
2913     arg.buffer = xmalloc(PATH_MAX);
2914     arg.buflen = PATH_MAX;
2915 
2916     p = path_enumerate(path, try_library_path, &arg);
2917 
2918     free(arg.buffer);
2919 
2920     return (p);
2921 }
2922 
2923 
2924 /*
2925  * Finds the library with the given name using the directory descriptors
2926  * listed in the LD_LIBRARY_PATH_FDS environment variable.
2927  *
2928  * Returns a freshly-opened close-on-exec file descriptor for the library,
2929  * or -1 if the library cannot be found.
2930  */
2931 static char *
2932 search_library_pathfds(const char *name, const char *path, int *fdp)
2933 {
2934 	char *envcopy, *fdstr, *found, *last_token;
2935 	size_t len;
2936 	int dirfd, fd;
2937 
2938 	dbg("%s('%s', '%s', fdp)", __func__, name, path);
2939 
2940 	/* Don't load from user-specified libdirs into setuid binaries. */
2941 	if (!trust)
2942 		return (NULL);
2943 
2944 	/* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */
2945 	if (path == NULL)
2946 		return (NULL);
2947 
2948 	/* LD_LIBRARY_PATH_FDS only works with relative paths. */
2949 	if (name[0] == '/') {
2950 		dbg("Absolute path (%s) passed to %s", name, __func__);
2951 		return (NULL);
2952 	}
2953 
2954 	/*
2955 	 * Use strtok_r() to walk the FD:FD:FD list.  This requires a local
2956 	 * copy of the path, as strtok_r rewrites separator tokens
2957 	 * with '\0'.
2958 	 */
2959 	found = NULL;
2960 	envcopy = xstrdup(path);
2961 	for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL;
2962 	    fdstr = strtok_r(NULL, ":", &last_token)) {
2963 		dirfd = parse_libdir(fdstr);
2964 		if (dirfd < 0)
2965 			break;
2966 		fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY);
2967 		if (fd >= 0) {
2968 			*fdp = fd;
2969 			len = strlen(fdstr) + strlen(name) + 3;
2970 			found = xmalloc(len);
2971 			if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) {
2972 				_rtld_error("error generating '%d/%s'",
2973 				    dirfd, name);
2974 				rtld_die();
2975 			}
2976 			dbg("open('%s') => %d", found, fd);
2977 			break;
2978 		}
2979 	}
2980 	free(envcopy);
2981 
2982 	return (found);
2983 }
2984 
2985 
2986 int
2987 dlclose(void *handle)
2988 {
2989     Obj_Entry *root;
2990     RtldLockState lockstate;
2991 
2992     wlock_acquire(rtld_bind_lock, &lockstate);
2993     root = dlcheck(handle);
2994     if (root == NULL) {
2995 	lock_release(rtld_bind_lock, &lockstate);
2996 	return -1;
2997     }
2998     LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
2999 	root->path);
3000 
3001     /* Unreference the object and its dependencies. */
3002     root->dl_refcount--;
3003 
3004     if (root->refcount == 1) {
3005 	/*
3006 	 * The object will be no longer referenced, so we must unload it.
3007 	 * First, call the fini functions.
3008 	 */
3009 	objlist_call_fini(&list_fini, root, &lockstate);
3010 
3011 	unref_dag(root);
3012 
3013 	/* Finish cleaning up the newly-unreferenced objects. */
3014 	GDB_STATE(RT_DELETE,&root->linkmap);
3015 	unload_object(root);
3016 	GDB_STATE(RT_CONSISTENT,NULL);
3017     } else
3018 	unref_dag(root);
3019 
3020     LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
3021     lock_release(rtld_bind_lock, &lockstate);
3022     return 0;
3023 }
3024 
3025 char *
3026 dlerror(void)
3027 {
3028     char *msg = error_message;
3029     error_message = NULL;
3030     return msg;
3031 }
3032 
3033 /*
3034  * This function is deprecated and has no effect.
3035  */
3036 void
3037 dllockinit(void *context,
3038 	   void *(*lock_create)(void *context),
3039            void (*rlock_acquire)(void *lock),
3040            void (*wlock_acquire)(void *lock),
3041            void (*lock_release)(void *lock),
3042            void (*lock_destroy)(void *lock),
3043 	   void (*context_destroy)(void *context))
3044 {
3045     static void *cur_context;
3046     static void (*cur_context_destroy)(void *);
3047 
3048     /* Just destroy the context from the previous call, if necessary. */
3049     if (cur_context_destroy != NULL)
3050 	cur_context_destroy(cur_context);
3051     cur_context = context;
3052     cur_context_destroy = context_destroy;
3053 }
3054 
3055 void *
3056 dlopen(const char *name, int mode)
3057 {
3058 
3059 	return (rtld_dlopen(name, -1, mode));
3060 }
3061 
3062 void *
3063 fdlopen(int fd, int mode)
3064 {
3065 
3066 	return (rtld_dlopen(NULL, fd, mode));
3067 }
3068 
3069 static void *
3070 rtld_dlopen(const char *name, int fd, int mode)
3071 {
3072     RtldLockState lockstate;
3073     int lo_flags;
3074 
3075     LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
3076     ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
3077     if (ld_tracing != NULL) {
3078 	rlock_acquire(rtld_bind_lock, &lockstate);
3079 	if (sigsetjmp(lockstate.env, 0) != 0)
3080 	    lock_upgrade(rtld_bind_lock, &lockstate);
3081 	environ = (char **)*get_program_var_addr("environ", &lockstate);
3082 	lock_release(rtld_bind_lock, &lockstate);
3083     }
3084     lo_flags = RTLD_LO_DLOPEN;
3085     if (mode & RTLD_NODELETE)
3086 	    lo_flags |= RTLD_LO_NODELETE;
3087     if (mode & RTLD_NOLOAD)
3088 	    lo_flags |= RTLD_LO_NOLOAD;
3089     if (ld_tracing != NULL)
3090 	    lo_flags |= RTLD_LO_TRACE;
3091 
3092     return (dlopen_object(name, fd, obj_main, lo_flags,
3093       mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL));
3094 }
3095 
3096 static void
3097 dlopen_cleanup(Obj_Entry *obj)
3098 {
3099 
3100 	obj->dl_refcount--;
3101 	unref_dag(obj);
3102 	if (obj->refcount == 0)
3103 		unload_object(obj);
3104 }
3105 
3106 static Obj_Entry *
3107 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags,
3108     int mode, RtldLockState *lockstate)
3109 {
3110     Obj_Entry *old_obj_tail;
3111     Obj_Entry *obj;
3112     Objlist initlist;
3113     RtldLockState mlockstate;
3114     int result;
3115 
3116     objlist_init(&initlist);
3117 
3118     if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) {
3119 	wlock_acquire(rtld_bind_lock, &mlockstate);
3120 	lockstate = &mlockstate;
3121     }
3122     GDB_STATE(RT_ADD,NULL);
3123 
3124     old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q));
3125     obj = NULL;
3126     if (name == NULL && fd == -1) {
3127 	obj = obj_main;
3128 	obj->refcount++;
3129     } else {
3130 	obj = load_object(name, fd, refobj, lo_flags);
3131     }
3132 
3133     if (obj) {
3134 	obj->dl_refcount++;
3135 	if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
3136 	    objlist_push_tail(&list_global, obj);
3137 	if (globallist_next(old_obj_tail) != NULL) {
3138 	    /* We loaded something new. */
3139 	    assert(globallist_next(old_obj_tail) == obj);
3140 	    result = load_needed_objects(obj,
3141 		lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY));
3142 	    init_dag(obj);
3143 	    ref_dag(obj);
3144 	    if (result != -1)
3145 		result = rtld_verify_versions(&obj->dagmembers);
3146 	    if (result != -1 && ld_tracing)
3147 		goto trace;
3148 	    if (result == -1 || relocate_object_dag(obj,
3149 	      (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld,
3150 	      (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
3151 	      lockstate) == -1) {
3152 		dlopen_cleanup(obj);
3153 		obj = NULL;
3154 	    } else if (lo_flags & RTLD_LO_EARLY) {
3155 		/*
3156 		 * Do not call the init functions for early loaded
3157 		 * filtees.  The image is still not initialized enough
3158 		 * for them to work.
3159 		 *
3160 		 * Our object is found by the global object list and
3161 		 * will be ordered among all init calls done right
3162 		 * before transferring control to main.
3163 		 */
3164 	    } else {
3165 		/* Make list of init functions to call. */
3166 		initlist_add_objects(obj, obj, &initlist);
3167 	    }
3168 	    /*
3169 	     * Process all no_delete or global objects here, given
3170 	     * them own DAGs to prevent their dependencies from being
3171 	     * unloaded.  This has to be done after we have loaded all
3172 	     * of the dependencies, so that we do not miss any.
3173 	     */
3174 	    if (obj != NULL)
3175 		process_z(obj);
3176 	} else {
3177 	    /*
3178 	     * Bump the reference counts for objects on this DAG.  If
3179 	     * this is the first dlopen() call for the object that was
3180 	     * already loaded as a dependency, initialize the dag
3181 	     * starting at it.
3182 	     */
3183 	    init_dag(obj);
3184 	    ref_dag(obj);
3185 
3186 	    if ((lo_flags & RTLD_LO_TRACE) != 0)
3187 		goto trace;
3188 	}
3189 	if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
3190 	  obj->z_nodelete) && !obj->ref_nodel) {
3191 	    dbg("obj %s nodelete", obj->path);
3192 	    ref_dag(obj);
3193 	    obj->z_nodelete = obj->ref_nodel = true;
3194 	}
3195     }
3196 
3197     LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
3198 	name);
3199     GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
3200 
3201     if (!(lo_flags & RTLD_LO_EARLY)) {
3202 	map_stacks_exec(lockstate);
3203     }
3204 
3205     if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW,
3206       (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
3207       lockstate) == -1) {
3208 	objlist_clear(&initlist);
3209 	dlopen_cleanup(obj);
3210 	if (lockstate == &mlockstate)
3211 	    lock_release(rtld_bind_lock, lockstate);
3212 	return (NULL);
3213     }
3214 
3215     if (!(lo_flags & RTLD_LO_EARLY)) {
3216 	/* Call the init functions. */
3217 	objlist_call_init(&initlist, lockstate);
3218     }
3219     objlist_clear(&initlist);
3220     if (lockstate == &mlockstate)
3221 	lock_release(rtld_bind_lock, lockstate);
3222     return obj;
3223 trace:
3224     trace_loaded_objects(obj);
3225     if (lockstate == &mlockstate)
3226 	lock_release(rtld_bind_lock, lockstate);
3227     exit(0);
3228 }
3229 
3230 static void *
3231 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
3232     int flags)
3233 {
3234     DoneList donelist;
3235     const Obj_Entry *obj, *defobj;
3236     const Elf_Sym *def;
3237     SymLook req;
3238     RtldLockState lockstate;
3239     tls_index ti;
3240     void *sym;
3241     int res;
3242 
3243     def = NULL;
3244     defobj = NULL;
3245     symlook_init(&req, name);
3246     req.ventry = ve;
3247     req.flags = flags | SYMLOOK_IN_PLT;
3248     req.lockstate = &lockstate;
3249 
3250     LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name);
3251     rlock_acquire(rtld_bind_lock, &lockstate);
3252     if (sigsetjmp(lockstate.env, 0) != 0)
3253 	    lock_upgrade(rtld_bind_lock, &lockstate);
3254     if (handle == NULL || handle == RTLD_NEXT ||
3255 	handle == RTLD_DEFAULT || handle == RTLD_SELF) {
3256 
3257 	if ((obj = obj_from_addr(retaddr)) == NULL) {
3258 	    _rtld_error("Cannot determine caller's shared object");
3259 	    lock_release(rtld_bind_lock, &lockstate);
3260 	    LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3261 	    return NULL;
3262 	}
3263 	if (handle == NULL) {	/* Just the caller's shared object. */
3264 	    res = symlook_obj(&req, obj);
3265 	    if (res == 0) {
3266 		def = req.sym_out;
3267 		defobj = req.defobj_out;
3268 	    }
3269 	} else if (handle == RTLD_NEXT || /* Objects after caller's */
3270 		   handle == RTLD_SELF) { /* ... caller included */
3271 	    if (handle == RTLD_NEXT)
3272 		obj = globallist_next(obj);
3273 	    TAILQ_FOREACH_FROM(obj, &obj_list, next) {
3274 		if (obj->marker)
3275 		    continue;
3276 		res = symlook_obj(&req, obj);
3277 		if (res == 0) {
3278 		    if (def == NULL ||
3279 		      ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) {
3280 			def = req.sym_out;
3281 			defobj = req.defobj_out;
3282 			if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3283 			    break;
3284 		    }
3285 		}
3286 	    }
3287 	    /*
3288 	     * Search the dynamic linker itself, and possibly resolve the
3289 	     * symbol from there.  This is how the application links to
3290 	     * dynamic linker services such as dlopen.
3291 	     */
3292 	    if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3293 		res = symlook_obj(&req, &obj_rtld);
3294 		if (res == 0) {
3295 		    def = req.sym_out;
3296 		    defobj = req.defobj_out;
3297 		}
3298 	    }
3299 	} else {
3300 	    assert(handle == RTLD_DEFAULT);
3301 	    res = symlook_default(&req, obj);
3302 	    if (res == 0) {
3303 		defobj = req.defobj_out;
3304 		def = req.sym_out;
3305 	    }
3306 	}
3307     } else {
3308 	if ((obj = dlcheck(handle)) == NULL) {
3309 	    lock_release(rtld_bind_lock, &lockstate);
3310 	    LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3311 	    return NULL;
3312 	}
3313 
3314 	donelist_init(&donelist);
3315 	if (obj->mainprog) {
3316             /* Handle obtained by dlopen(NULL, ...) implies global scope. */
3317 	    res = symlook_global(&req, &donelist);
3318 	    if (res == 0) {
3319 		def = req.sym_out;
3320 		defobj = req.defobj_out;
3321 	    }
3322 	    /*
3323 	     * Search the dynamic linker itself, and possibly resolve the
3324 	     * symbol from there.  This is how the application links to
3325 	     * dynamic linker services such as dlopen.
3326 	     */
3327 	    if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3328 		res = symlook_obj(&req, &obj_rtld);
3329 		if (res == 0) {
3330 		    def = req.sym_out;
3331 		    defobj = req.defobj_out;
3332 		}
3333 	    }
3334 	}
3335 	else {
3336 	    /* Search the whole DAG rooted at the given object. */
3337 	    res = symlook_list(&req, &obj->dagmembers, &donelist);
3338 	    if (res == 0) {
3339 		def = req.sym_out;
3340 		defobj = req.defobj_out;
3341 	    }
3342 	}
3343     }
3344 
3345     if (def != NULL) {
3346 	lock_release(rtld_bind_lock, &lockstate);
3347 
3348 	/*
3349 	 * The value required by the caller is derived from the value
3350 	 * of the symbol. this is simply the relocated value of the
3351 	 * symbol.
3352 	 */
3353 	if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
3354 	    sym = make_function_pointer(def, defobj);
3355 	else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
3356 	    sym = rtld_resolve_ifunc(defobj, def);
3357 	else if (ELF_ST_TYPE(def->st_info) == STT_TLS) {
3358 	    ti.ti_module = defobj->tlsindex;
3359 	    ti.ti_offset = def->st_value;
3360 	    sym = __tls_get_addr(&ti);
3361 	} else
3362 	    sym = defobj->relocbase + def->st_value;
3363 	LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name);
3364 	return (sym);
3365     }
3366 
3367     _rtld_error("Undefined symbol \"%s\"", name);
3368     lock_release(rtld_bind_lock, &lockstate);
3369     LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3370     return NULL;
3371 }
3372 
3373 void *
3374 dlsym(void *handle, const char *name)
3375 {
3376 	return do_dlsym(handle, name, __builtin_return_address(0), NULL,
3377 	    SYMLOOK_DLSYM);
3378 }
3379 
3380 dlfunc_t
3381 dlfunc(void *handle, const char *name)
3382 {
3383 	union {
3384 		void *d;
3385 		dlfunc_t f;
3386 	} rv;
3387 
3388 	rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
3389 	    SYMLOOK_DLSYM);
3390 	return (rv.f);
3391 }
3392 
3393 void *
3394 dlvsym(void *handle, const char *name, const char *version)
3395 {
3396 	Ver_Entry ventry;
3397 
3398 	ventry.name = version;
3399 	ventry.file = NULL;
3400 	ventry.hash = elf_hash(version);
3401 	ventry.flags= 0;
3402 	return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
3403 	    SYMLOOK_DLSYM);
3404 }
3405 
3406 int
3407 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
3408 {
3409     const Obj_Entry *obj;
3410     RtldLockState lockstate;
3411 
3412     rlock_acquire(rtld_bind_lock, &lockstate);
3413     obj = obj_from_addr(addr);
3414     if (obj == NULL) {
3415         _rtld_error("No shared object contains address");
3416 	lock_release(rtld_bind_lock, &lockstate);
3417         return (0);
3418     }
3419     rtld_fill_dl_phdr_info(obj, phdr_info);
3420     lock_release(rtld_bind_lock, &lockstate);
3421     return (1);
3422 }
3423 
3424 int
3425 dladdr(const void *addr, Dl_info *info)
3426 {
3427     const Obj_Entry *obj;
3428     const Elf_Sym *def;
3429     void *symbol_addr;
3430     unsigned long symoffset;
3431     RtldLockState lockstate;
3432 
3433     rlock_acquire(rtld_bind_lock, &lockstate);
3434     obj = obj_from_addr(addr);
3435     if (obj == NULL) {
3436         _rtld_error("No shared object contains address");
3437 	lock_release(rtld_bind_lock, &lockstate);
3438         return 0;
3439     }
3440     info->dli_fname = obj->path;
3441     info->dli_fbase = obj->mapbase;
3442     info->dli_saddr = (void *)0;
3443     info->dli_sname = NULL;
3444 
3445     /*
3446      * Walk the symbol list looking for the symbol whose address is
3447      * closest to the address sent in.
3448      */
3449     for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) {
3450         def = obj->symtab + symoffset;
3451 
3452         /*
3453          * For skip the symbol if st_shndx is either SHN_UNDEF or
3454          * SHN_COMMON.
3455          */
3456         if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
3457             continue;
3458 
3459         /*
3460          * If the symbol is greater than the specified address, or if it
3461          * is further away from addr than the current nearest symbol,
3462          * then reject it.
3463          */
3464         symbol_addr = obj->relocbase + def->st_value;
3465         if (symbol_addr > addr || symbol_addr < info->dli_saddr)
3466             continue;
3467 
3468         /* Update our idea of the nearest symbol. */
3469         info->dli_sname = obj->strtab + def->st_name;
3470         info->dli_saddr = symbol_addr;
3471 
3472         /* Exact match? */
3473         if (info->dli_saddr == addr)
3474             break;
3475     }
3476     lock_release(rtld_bind_lock, &lockstate);
3477     return 1;
3478 }
3479 
3480 int
3481 dlinfo(void *handle, int request, void *p)
3482 {
3483     const Obj_Entry *obj;
3484     RtldLockState lockstate;
3485     int error;
3486 
3487     rlock_acquire(rtld_bind_lock, &lockstate);
3488 
3489     if (handle == NULL || handle == RTLD_SELF) {
3490 	void *retaddr;
3491 
3492 	retaddr = __builtin_return_address(0);	/* __GNUC__ only */
3493 	if ((obj = obj_from_addr(retaddr)) == NULL)
3494 	    _rtld_error("Cannot determine caller's shared object");
3495     } else
3496 	obj = dlcheck(handle);
3497 
3498     if (obj == NULL) {
3499 	lock_release(rtld_bind_lock, &lockstate);
3500 	return (-1);
3501     }
3502 
3503     error = 0;
3504     switch (request) {
3505     case RTLD_DI_LINKMAP:
3506 	*((struct link_map const **)p) = &obj->linkmap;
3507 	break;
3508     case RTLD_DI_ORIGIN:
3509 	error = rtld_dirname(obj->path, p);
3510 	break;
3511 
3512     case RTLD_DI_SERINFOSIZE:
3513     case RTLD_DI_SERINFO:
3514 	error = do_search_info(obj, request, (struct dl_serinfo *)p);
3515 	break;
3516 
3517     default:
3518 	_rtld_error("Invalid request %d passed to dlinfo()", request);
3519 	error = -1;
3520     }
3521 
3522     lock_release(rtld_bind_lock, &lockstate);
3523 
3524     return (error);
3525 }
3526 
3527 static void
3528 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
3529 {
3530 
3531 	phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
3532 	phdr_info->dlpi_name = obj->path;
3533 	phdr_info->dlpi_phdr = obj->phdr;
3534 	phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
3535 	phdr_info->dlpi_tls_modid = obj->tlsindex;
3536 	phdr_info->dlpi_tls_data = obj->tlsinit;
3537 	phdr_info->dlpi_adds = obj_loads;
3538 	phdr_info->dlpi_subs = obj_loads - obj_count;
3539 }
3540 
3541 int
3542 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
3543 {
3544 	struct dl_phdr_info phdr_info;
3545 	Obj_Entry *obj, marker;
3546 	RtldLockState bind_lockstate, phdr_lockstate;
3547 	int error;
3548 
3549 	bzero(&marker, sizeof(marker));
3550 	marker.marker = true;
3551 	error = 0;
3552 
3553 	wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
3554 	rlock_acquire(rtld_bind_lock, &bind_lockstate);
3555 	for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) {
3556 		TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next);
3557 		rtld_fill_dl_phdr_info(obj, &phdr_info);
3558 		lock_release(rtld_bind_lock, &bind_lockstate);
3559 
3560 		error = callback(&phdr_info, sizeof phdr_info, param);
3561 
3562 		rlock_acquire(rtld_bind_lock, &bind_lockstate);
3563 		obj = globallist_next(&marker);
3564 		TAILQ_REMOVE(&obj_list, &marker, next);
3565 		if (error != 0) {
3566 			lock_release(rtld_bind_lock, &bind_lockstate);
3567 			lock_release(rtld_phdr_lock, &phdr_lockstate);
3568 			return (error);
3569 		}
3570 	}
3571 
3572 	if (error == 0) {
3573 		rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info);
3574 		lock_release(rtld_bind_lock, &bind_lockstate);
3575 		error = callback(&phdr_info, sizeof(phdr_info), param);
3576 	}
3577 	lock_release(rtld_phdr_lock, &phdr_lockstate);
3578 	return (error);
3579 }
3580 
3581 static void *
3582 fill_search_info(const char *dir, size_t dirlen, void *param)
3583 {
3584     struct fill_search_info_args *arg;
3585 
3586     arg = param;
3587 
3588     if (arg->request == RTLD_DI_SERINFOSIZE) {
3589 	arg->serinfo->dls_cnt ++;
3590 	arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1;
3591     } else {
3592 	struct dl_serpath *s_entry;
3593 
3594 	s_entry = arg->serpath;
3595 	s_entry->dls_name  = arg->strspace;
3596 	s_entry->dls_flags = arg->flags;
3597 
3598 	strncpy(arg->strspace, dir, dirlen);
3599 	arg->strspace[dirlen] = '\0';
3600 
3601 	arg->strspace += dirlen + 1;
3602 	arg->serpath++;
3603     }
3604 
3605     return (NULL);
3606 }
3607 
3608 static int
3609 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
3610 {
3611     struct dl_serinfo _info;
3612     struct fill_search_info_args args;
3613 
3614     args.request = RTLD_DI_SERINFOSIZE;
3615     args.serinfo = &_info;
3616 
3617     _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
3618     _info.dls_cnt  = 0;
3619 
3620     path_enumerate(obj->rpath, fill_search_info, &args);
3621     path_enumerate(ld_library_path, fill_search_info, &args);
3622     path_enumerate(obj->runpath, fill_search_info, &args);
3623     path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args);
3624     if (!obj->z_nodeflib)
3625       path_enumerate(ld_standard_library_path, fill_search_info, &args);
3626 
3627 
3628     if (request == RTLD_DI_SERINFOSIZE) {
3629 	info->dls_size = _info.dls_size;
3630 	info->dls_cnt = _info.dls_cnt;
3631 	return (0);
3632     }
3633 
3634     if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
3635 	_rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
3636 	return (-1);
3637     }
3638 
3639     args.request  = RTLD_DI_SERINFO;
3640     args.serinfo  = info;
3641     args.serpath  = &info->dls_serpath[0];
3642     args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
3643 
3644     args.flags = LA_SER_RUNPATH;
3645     if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
3646 	return (-1);
3647 
3648     args.flags = LA_SER_LIBPATH;
3649     if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
3650 	return (-1);
3651 
3652     args.flags = LA_SER_RUNPATH;
3653     if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL)
3654 	return (-1);
3655 
3656     args.flags = LA_SER_CONFIG;
3657     if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args)
3658       != NULL)
3659 	return (-1);
3660 
3661     args.flags = LA_SER_DEFAULT;
3662     if (!obj->z_nodeflib &&
3663       path_enumerate(ld_standard_library_path, fill_search_info, &args) != NULL)
3664 	return (-1);
3665     return (0);
3666 }
3667 
3668 static int
3669 rtld_dirname(const char *path, char *bname)
3670 {
3671     const char *endp;
3672 
3673     /* Empty or NULL string gets treated as "." */
3674     if (path == NULL || *path == '\0') {
3675 	bname[0] = '.';
3676 	bname[1] = '\0';
3677 	return (0);
3678     }
3679 
3680     /* Strip trailing slashes */
3681     endp = path + strlen(path) - 1;
3682     while (endp > path && *endp == '/')
3683 	endp--;
3684 
3685     /* Find the start of the dir */
3686     while (endp > path && *endp != '/')
3687 	endp--;
3688 
3689     /* Either the dir is "/" or there are no slashes */
3690     if (endp == path) {
3691 	bname[0] = *endp == '/' ? '/' : '.';
3692 	bname[1] = '\0';
3693 	return (0);
3694     } else {
3695 	do {
3696 	    endp--;
3697 	} while (endp > path && *endp == '/');
3698     }
3699 
3700     if (endp - path + 2 > PATH_MAX)
3701     {
3702 	_rtld_error("Filename is too long: %s", path);
3703 	return(-1);
3704     }
3705 
3706     strncpy(bname, path, endp - path + 1);
3707     bname[endp - path + 1] = '\0';
3708     return (0);
3709 }
3710 
3711 static int
3712 rtld_dirname_abs(const char *path, char *base)
3713 {
3714 	char *last;
3715 
3716 	if (realpath(path, base) == NULL)
3717 		return (-1);
3718 	dbg("%s -> %s", path, base);
3719 	last = strrchr(base, '/');
3720 	if (last == NULL)
3721 		return (-1);
3722 	if (last != base)
3723 		*last = '\0';
3724 	return (0);
3725 }
3726 
3727 static void
3728 linkmap_add(Obj_Entry *obj)
3729 {
3730     struct link_map *l = &obj->linkmap;
3731     struct link_map *prev;
3732 
3733     obj->linkmap.l_name = obj->path;
3734     obj->linkmap.l_addr = obj->mapbase;
3735     obj->linkmap.l_ld = obj->dynamic;
3736 #ifdef __mips__
3737     /* GDB needs load offset on MIPS to use the symbols */
3738     obj->linkmap.l_offs = obj->relocbase;
3739 #endif
3740 
3741     if (r_debug.r_map == NULL) {
3742 	r_debug.r_map = l;
3743 	return;
3744     }
3745 
3746     /*
3747      * Scan to the end of the list, but not past the entry for the
3748      * dynamic linker, which we want to keep at the very end.
3749      */
3750     for (prev = r_debug.r_map;
3751       prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
3752       prev = prev->l_next)
3753 	;
3754 
3755     /* Link in the new entry. */
3756     l->l_prev = prev;
3757     l->l_next = prev->l_next;
3758     if (l->l_next != NULL)
3759 	l->l_next->l_prev = l;
3760     prev->l_next = l;
3761 }
3762 
3763 static void
3764 linkmap_delete(Obj_Entry *obj)
3765 {
3766     struct link_map *l = &obj->linkmap;
3767 
3768     if (l->l_prev == NULL) {
3769 	if ((r_debug.r_map = l->l_next) != NULL)
3770 	    l->l_next->l_prev = NULL;
3771 	return;
3772     }
3773 
3774     if ((l->l_prev->l_next = l->l_next) != NULL)
3775 	l->l_next->l_prev = l->l_prev;
3776 }
3777 
3778 /*
3779  * Function for the debugger to set a breakpoint on to gain control.
3780  *
3781  * The two parameters allow the debugger to easily find and determine
3782  * what the runtime loader is doing and to whom it is doing it.
3783  *
3784  * When the loadhook trap is hit (r_debug_state, set at program
3785  * initialization), the arguments can be found on the stack:
3786  *
3787  *  +8   struct link_map *m
3788  *  +4   struct r_debug  *rd
3789  *  +0   RetAddr
3790  */
3791 void
3792 r_debug_state(struct r_debug* rd, struct link_map *m)
3793 {
3794     /*
3795      * The following is a hack to force the compiler to emit calls to
3796      * this function, even when optimizing.  If the function is empty,
3797      * the compiler is not obliged to emit any code for calls to it,
3798      * even when marked __noinline.  However, gdb depends on those
3799      * calls being made.
3800      */
3801     __compiler_membar();
3802 }
3803 
3804 /*
3805  * A function called after init routines have completed. This can be used to
3806  * break before a program's entry routine is called, and can be used when
3807  * main is not available in the symbol table.
3808  */
3809 void
3810 _r_debug_postinit(struct link_map *m)
3811 {
3812 
3813 	/* See r_debug_state(). */
3814 	__compiler_membar();
3815 }
3816 
3817 /*
3818  * Get address of the pointer variable in the main program.
3819  * Prefer non-weak symbol over the weak one.
3820  */
3821 static const void **
3822 get_program_var_addr(const char *name, RtldLockState *lockstate)
3823 {
3824     SymLook req;
3825     DoneList donelist;
3826 
3827     symlook_init(&req, name);
3828     req.lockstate = lockstate;
3829     donelist_init(&donelist);
3830     if (symlook_global(&req, &donelist) != 0)
3831 	return (NULL);
3832     if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC)
3833 	return ((const void **)make_function_pointer(req.sym_out,
3834 	  req.defobj_out));
3835     else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC)
3836 	return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out));
3837     else
3838 	return ((const void **)(req.defobj_out->relocbase +
3839 	  req.sym_out->st_value));
3840 }
3841 
3842 /*
3843  * Set a pointer variable in the main program to the given value.  This
3844  * is used to set key variables such as "environ" before any of the
3845  * init functions are called.
3846  */
3847 static void
3848 set_program_var(const char *name, const void *value)
3849 {
3850     const void **addr;
3851 
3852     if ((addr = get_program_var_addr(name, NULL)) != NULL) {
3853 	dbg("\"%s\": *%p <-- %p", name, addr, value);
3854 	*addr = value;
3855     }
3856 }
3857 
3858 /*
3859  * Search the global objects, including dependencies and main object,
3860  * for the given symbol.
3861  */
3862 static int
3863 symlook_global(SymLook *req, DoneList *donelist)
3864 {
3865     SymLook req1;
3866     const Objlist_Entry *elm;
3867     int res;
3868 
3869     symlook_init_from_req(&req1, req);
3870 
3871     /* Search all objects loaded at program start up. */
3872     if (req->defobj_out == NULL ||
3873       ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
3874 	res = symlook_list(&req1, &list_main, donelist);
3875 	if (res == 0 && (req->defobj_out == NULL ||
3876 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3877 	    req->sym_out = req1.sym_out;
3878 	    req->defobj_out = req1.defobj_out;
3879 	    assert(req->defobj_out != NULL);
3880 	}
3881     }
3882 
3883     /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
3884     STAILQ_FOREACH(elm, &list_global, link) {
3885 	if (req->defobj_out != NULL &&
3886 	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
3887 	    break;
3888 	res = symlook_list(&req1, &elm->obj->dagmembers, donelist);
3889 	if (res == 0 && (req->defobj_out == NULL ||
3890 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3891 	    req->sym_out = req1.sym_out;
3892 	    req->defobj_out = req1.defobj_out;
3893 	    assert(req->defobj_out != NULL);
3894 	}
3895     }
3896 
3897     return (req->sym_out != NULL ? 0 : ESRCH);
3898 }
3899 
3900 /*
3901  * Given a symbol name in a referencing object, find the corresponding
3902  * definition of the symbol.  Returns a pointer to the symbol, or NULL if
3903  * no definition was found.  Returns a pointer to the Obj_Entry of the
3904  * defining object via the reference parameter DEFOBJ_OUT.
3905  */
3906 static int
3907 symlook_default(SymLook *req, const Obj_Entry *refobj)
3908 {
3909     DoneList donelist;
3910     const Objlist_Entry *elm;
3911     SymLook req1;
3912     int res;
3913 
3914     donelist_init(&donelist);
3915     symlook_init_from_req(&req1, req);
3916 
3917     /* Look first in the referencing object if linked symbolically. */
3918     if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
3919 	res = symlook_obj(&req1, refobj);
3920 	if (res == 0) {
3921 	    req->sym_out = req1.sym_out;
3922 	    req->defobj_out = req1.defobj_out;
3923 	    assert(req->defobj_out != NULL);
3924 	}
3925     }
3926 
3927     symlook_global(req, &donelist);
3928 
3929     /* Search all dlopened DAGs containing the referencing object. */
3930     STAILQ_FOREACH(elm, &refobj->dldags, link) {
3931 	if (req->sym_out != NULL &&
3932 	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
3933 	    break;
3934 	res = symlook_list(&req1, &elm->obj->dagmembers, &donelist);
3935 	if (res == 0 && (req->sym_out == NULL ||
3936 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3937 	    req->sym_out = req1.sym_out;
3938 	    req->defobj_out = req1.defobj_out;
3939 	    assert(req->defobj_out != NULL);
3940 	}
3941     }
3942 
3943     /*
3944      * Search the dynamic linker itself, and possibly resolve the
3945      * symbol from there.  This is how the application links to
3946      * dynamic linker services such as dlopen.
3947      */
3948     if (req->sym_out == NULL ||
3949       ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
3950 	res = symlook_obj(&req1, &obj_rtld);
3951 	if (res == 0) {
3952 	    req->sym_out = req1.sym_out;
3953 	    req->defobj_out = req1.defobj_out;
3954 	    assert(req->defobj_out != NULL);
3955 	}
3956     }
3957 
3958     return (req->sym_out != NULL ? 0 : ESRCH);
3959 }
3960 
3961 static int
3962 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp)
3963 {
3964     const Elf_Sym *def;
3965     const Obj_Entry *defobj;
3966     const Objlist_Entry *elm;
3967     SymLook req1;
3968     int res;
3969 
3970     def = NULL;
3971     defobj = NULL;
3972     STAILQ_FOREACH(elm, objlist, link) {
3973 	if (donelist_check(dlp, elm->obj))
3974 	    continue;
3975 	symlook_init_from_req(&req1, req);
3976 	if ((res = symlook_obj(&req1, elm->obj)) == 0) {
3977 	    if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
3978 		def = req1.sym_out;
3979 		defobj = req1.defobj_out;
3980 		if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3981 		    break;
3982 	    }
3983 	}
3984     }
3985     if (def != NULL) {
3986 	req->sym_out = def;
3987 	req->defobj_out = defobj;
3988 	return (0);
3989     }
3990     return (ESRCH);
3991 }
3992 
3993 /*
3994  * Search the chain of DAGS cointed to by the given Needed_Entry
3995  * for a symbol of the given name.  Each DAG is scanned completely
3996  * before advancing to the next one.  Returns a pointer to the symbol,
3997  * or NULL if no definition was found.
3998  */
3999 static int
4000 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp)
4001 {
4002     const Elf_Sym *def;
4003     const Needed_Entry *n;
4004     const Obj_Entry *defobj;
4005     SymLook req1;
4006     int res;
4007 
4008     def = NULL;
4009     defobj = NULL;
4010     symlook_init_from_req(&req1, req);
4011     for (n = needed; n != NULL; n = n->next) {
4012 	if (n->obj == NULL ||
4013 	    (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0)
4014 	    continue;
4015 	if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
4016 	    def = req1.sym_out;
4017 	    defobj = req1.defobj_out;
4018 	    if (ELF_ST_BIND(def->st_info) != STB_WEAK)
4019 		break;
4020 	}
4021     }
4022     if (def != NULL) {
4023 	req->sym_out = def;
4024 	req->defobj_out = defobj;
4025 	return (0);
4026     }
4027     return (ESRCH);
4028 }
4029 
4030 /*
4031  * Search the symbol table of a single shared object for a symbol of
4032  * the given name and version, if requested.  Returns a pointer to the
4033  * symbol, or NULL if no definition was found.  If the object is
4034  * filter, return filtered symbol from filtee.
4035  *
4036  * The symbol's hash value is passed in for efficiency reasons; that
4037  * eliminates many recomputations of the hash value.
4038  */
4039 int
4040 symlook_obj(SymLook *req, const Obj_Entry *obj)
4041 {
4042     DoneList donelist;
4043     SymLook req1;
4044     int flags, res, mres;
4045 
4046     /*
4047      * If there is at least one valid hash at this point, we prefer to
4048      * use the faster GNU version if available.
4049      */
4050     if (obj->valid_hash_gnu)
4051 	mres = symlook_obj1_gnu(req, obj);
4052     else if (obj->valid_hash_sysv)
4053 	mres = symlook_obj1_sysv(req, obj);
4054     else
4055 	return (EINVAL);
4056 
4057     if (mres == 0) {
4058 	if (obj->needed_filtees != NULL) {
4059 	    flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
4060 	    load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
4061 	    donelist_init(&donelist);
4062 	    symlook_init_from_req(&req1, req);
4063 	    res = symlook_needed(&req1, obj->needed_filtees, &donelist);
4064 	    if (res == 0) {
4065 		req->sym_out = req1.sym_out;
4066 		req->defobj_out = req1.defobj_out;
4067 	    }
4068 	    return (res);
4069 	}
4070 	if (obj->needed_aux_filtees != NULL) {
4071 	    flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
4072 	    load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
4073 	    donelist_init(&donelist);
4074 	    symlook_init_from_req(&req1, req);
4075 	    res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist);
4076 	    if (res == 0) {
4077 		req->sym_out = req1.sym_out;
4078 		req->defobj_out = req1.defobj_out;
4079 		return (res);
4080 	    }
4081 	}
4082     }
4083     return (mres);
4084 }
4085 
4086 /* Symbol match routine common to both hash functions */
4087 static bool
4088 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result,
4089     const unsigned long symnum)
4090 {
4091 	Elf_Versym verndx;
4092 	const Elf_Sym *symp;
4093 	const char *strp;
4094 
4095 	symp = obj->symtab + symnum;
4096 	strp = obj->strtab + symp->st_name;
4097 
4098 	switch (ELF_ST_TYPE(symp->st_info)) {
4099 	case STT_FUNC:
4100 	case STT_NOTYPE:
4101 	case STT_OBJECT:
4102 	case STT_COMMON:
4103 	case STT_GNU_IFUNC:
4104 		if (symp->st_value == 0)
4105 			return (false);
4106 		/* fallthrough */
4107 	case STT_TLS:
4108 		if (symp->st_shndx != SHN_UNDEF)
4109 			break;
4110 #ifndef __mips__
4111 		else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
4112 		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
4113 			break;
4114 		/* fallthrough */
4115 #endif
4116 	default:
4117 		return (false);
4118 	}
4119 	if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0)
4120 		return (false);
4121 
4122 	if (req->ventry == NULL) {
4123 		if (obj->versyms != NULL) {
4124 			verndx = VER_NDX(obj->versyms[symnum]);
4125 			if (verndx > obj->vernum) {
4126 				_rtld_error(
4127 				    "%s: symbol %s references wrong version %d",
4128 				    obj->path, obj->strtab + symnum, verndx);
4129 				return (false);
4130 			}
4131 			/*
4132 			 * If we are not called from dlsym (i.e. this
4133 			 * is a normal relocation from unversioned
4134 			 * binary), accept the symbol immediately if
4135 			 * it happens to have first version after this
4136 			 * shared object became versioned.  Otherwise,
4137 			 * if symbol is versioned and not hidden,
4138 			 * remember it. If it is the only symbol with
4139 			 * this name exported by the shared object, it
4140 			 * will be returned as a match by the calling
4141 			 * function. If symbol is global (verndx < 2)
4142 			 * accept it unconditionally.
4143 			 */
4144 			if ((req->flags & SYMLOOK_DLSYM) == 0 &&
4145 			    verndx == VER_NDX_GIVEN) {
4146 				result->sym_out = symp;
4147 				return (true);
4148 			}
4149 			else if (verndx >= VER_NDX_GIVEN) {
4150 				if ((obj->versyms[symnum] & VER_NDX_HIDDEN)
4151 				    == 0) {
4152 					if (result->vsymp == NULL)
4153 						result->vsymp = symp;
4154 					result->vcount++;
4155 				}
4156 				return (false);
4157 			}
4158 		}
4159 		result->sym_out = symp;
4160 		return (true);
4161 	}
4162 	if (obj->versyms == NULL) {
4163 		if (object_match_name(obj, req->ventry->name)) {
4164 			_rtld_error("%s: object %s should provide version %s "
4165 			    "for symbol %s", obj_rtld.path, obj->path,
4166 			    req->ventry->name, obj->strtab + symnum);
4167 			return (false);
4168 		}
4169 	} else {
4170 		verndx = VER_NDX(obj->versyms[symnum]);
4171 		if (verndx > obj->vernum) {
4172 			_rtld_error("%s: symbol %s references wrong version %d",
4173 			    obj->path, obj->strtab + symnum, verndx);
4174 			return (false);
4175 		}
4176 		if (obj->vertab[verndx].hash != req->ventry->hash ||
4177 		    strcmp(obj->vertab[verndx].name, req->ventry->name)) {
4178 			/*
4179 			 * Version does not match. Look if this is a
4180 			 * global symbol and if it is not hidden. If
4181 			 * global symbol (verndx < 2) is available,
4182 			 * use it. Do not return symbol if we are
4183 			 * called by dlvsym, because dlvsym looks for
4184 			 * a specific version and default one is not
4185 			 * what dlvsym wants.
4186 			 */
4187 			if ((req->flags & SYMLOOK_DLSYM) ||
4188 			    (verndx >= VER_NDX_GIVEN) ||
4189 			    (obj->versyms[symnum] & VER_NDX_HIDDEN))
4190 				return (false);
4191 		}
4192 	}
4193 	result->sym_out = symp;
4194 	return (true);
4195 }
4196 
4197 /*
4198  * Search for symbol using SysV hash function.
4199  * obj->buckets is known not to be NULL at this point; the test for this was
4200  * performed with the obj->valid_hash_sysv assignment.
4201  */
4202 static int
4203 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj)
4204 {
4205 	unsigned long symnum;
4206 	Sym_Match_Result matchres;
4207 
4208 	matchres.sym_out = NULL;
4209 	matchres.vsymp = NULL;
4210 	matchres.vcount = 0;
4211 
4212 	for (symnum = obj->buckets[req->hash % obj->nbuckets];
4213 	    symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
4214 		if (symnum >= obj->nchains)
4215 			return (ESRCH);	/* Bad object */
4216 
4217 		if (matched_symbol(req, obj, &matchres, symnum)) {
4218 			req->sym_out = matchres.sym_out;
4219 			req->defobj_out = obj;
4220 			return (0);
4221 		}
4222 	}
4223 	if (matchres.vcount == 1) {
4224 		req->sym_out = matchres.vsymp;
4225 		req->defobj_out = obj;
4226 		return (0);
4227 	}
4228 	return (ESRCH);
4229 }
4230 
4231 /* Search for symbol using GNU hash function */
4232 static int
4233 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj)
4234 {
4235 	Elf_Addr bloom_word;
4236 	const Elf32_Word *hashval;
4237 	Elf32_Word bucket;
4238 	Sym_Match_Result matchres;
4239 	unsigned int h1, h2;
4240 	unsigned long symnum;
4241 
4242 	matchres.sym_out = NULL;
4243 	matchres.vsymp = NULL;
4244 	matchres.vcount = 0;
4245 
4246 	/* Pick right bitmask word from Bloom filter array */
4247 	bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) &
4248 	    obj->maskwords_bm_gnu];
4249 
4250 	/* Calculate modulus word size of gnu hash and its derivative */
4251 	h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1);
4252 	h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1));
4253 
4254 	/* Filter out the "definitely not in set" queries */
4255 	if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0)
4256 		return (ESRCH);
4257 
4258 	/* Locate hash chain and corresponding value element*/
4259 	bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu];
4260 	if (bucket == 0)
4261 		return (ESRCH);
4262 	hashval = &obj->chain_zero_gnu[bucket];
4263 	do {
4264 		if (((*hashval ^ req->hash_gnu) >> 1) == 0) {
4265 			symnum = hashval - obj->chain_zero_gnu;
4266 			if (matched_symbol(req, obj, &matchres, symnum)) {
4267 				req->sym_out = matchres.sym_out;
4268 				req->defobj_out = obj;
4269 				return (0);
4270 			}
4271 		}
4272 	} while ((*hashval++ & 1) == 0);
4273 	if (matchres.vcount == 1) {
4274 		req->sym_out = matchres.vsymp;
4275 		req->defobj_out = obj;
4276 		return (0);
4277 	}
4278 	return (ESRCH);
4279 }
4280 
4281 static void
4282 trace_loaded_objects(Obj_Entry *obj)
4283 {
4284     char	*fmt1, *fmt2, *fmt, *main_local, *list_containers;
4285     int		c;
4286 
4287     if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL)
4288 	main_local = "";
4289 
4290     if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL)
4291 	fmt1 = "\t%o => %p (%x)\n";
4292 
4293     if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL)
4294 	fmt2 = "\t%o (%x)\n";
4295 
4296     list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL"));
4297 
4298     TAILQ_FOREACH_FROM(obj, &obj_list, next) {
4299 	Needed_Entry		*needed;
4300 	char			*name, *path;
4301 	bool			is_lib;
4302 
4303 	if (obj->marker)
4304 	    continue;
4305 	if (list_containers && obj->needed != NULL)
4306 	    rtld_printf("%s:\n", obj->path);
4307 	for (needed = obj->needed; needed; needed = needed->next) {
4308 	    if (needed->obj != NULL) {
4309 		if (needed->obj->traced && !list_containers)
4310 		    continue;
4311 		needed->obj->traced = true;
4312 		path = needed->obj->path;
4313 	    } else
4314 		path = "not found";
4315 
4316 	    name = (char *)obj->strtab + needed->name;
4317 	    is_lib = strncmp(name, "lib", 3) == 0;	/* XXX - bogus */
4318 
4319 	    fmt = is_lib ? fmt1 : fmt2;
4320 	    while ((c = *fmt++) != '\0') {
4321 		switch (c) {
4322 		default:
4323 		    rtld_putchar(c);
4324 		    continue;
4325 		case '\\':
4326 		    switch (c = *fmt) {
4327 		    case '\0':
4328 			continue;
4329 		    case 'n':
4330 			rtld_putchar('\n');
4331 			break;
4332 		    case 't':
4333 			rtld_putchar('\t');
4334 			break;
4335 		    }
4336 		    break;
4337 		case '%':
4338 		    switch (c = *fmt) {
4339 		    case '\0':
4340 			continue;
4341 		    case '%':
4342 		    default:
4343 			rtld_putchar(c);
4344 			break;
4345 		    case 'A':
4346 			rtld_putstr(main_local);
4347 			break;
4348 		    case 'a':
4349 			rtld_putstr(obj_main->path);
4350 			break;
4351 		    case 'o':
4352 			rtld_putstr(name);
4353 			break;
4354 #if 0
4355 		    case 'm':
4356 			rtld_printf("%d", sodp->sod_major);
4357 			break;
4358 		    case 'n':
4359 			rtld_printf("%d", sodp->sod_minor);
4360 			break;
4361 #endif
4362 		    case 'p':
4363 			rtld_putstr(path);
4364 			break;
4365 		    case 'x':
4366 			rtld_printf("%p", needed->obj ? needed->obj->mapbase :
4367 			  0);
4368 			break;
4369 		    }
4370 		    break;
4371 		}
4372 		++fmt;
4373 	    }
4374 	}
4375     }
4376 }
4377 
4378 /*
4379  * Unload a dlopened object and its dependencies from memory and from
4380  * our data structures.  It is assumed that the DAG rooted in the
4381  * object has already been unreferenced, and that the object has a
4382  * reference count of 0.
4383  */
4384 static void
4385 unload_object(Obj_Entry *root)
4386 {
4387 	Obj_Entry *obj, *obj1;
4388 
4389 	assert(root->refcount == 0);
4390 
4391 	/*
4392 	 * Pass over the DAG removing unreferenced objects from
4393 	 * appropriate lists.
4394 	 */
4395 	unlink_object(root);
4396 
4397 	/* Unmap all objects that are no longer referenced. */
4398 	TAILQ_FOREACH_SAFE(obj, &obj_list, next, obj1) {
4399 		if (obj->marker || obj->refcount != 0)
4400 			continue;
4401 		LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase,
4402 		    obj->mapsize, 0, obj->path);
4403 		dbg("unloading \"%s\"", obj->path);
4404 		unload_filtees(root);
4405 		munmap(obj->mapbase, obj->mapsize);
4406 		linkmap_delete(obj);
4407 		TAILQ_REMOVE(&obj_list, obj, next);
4408 		obj_count--;
4409 		obj_free(obj);
4410 	}
4411 }
4412 
4413 static void
4414 unlink_object(Obj_Entry *root)
4415 {
4416     Objlist_Entry *elm;
4417 
4418     if (root->refcount == 0) {
4419 	/* Remove the object from the RTLD_GLOBAL list. */
4420 	objlist_remove(&list_global, root);
4421 
4422     	/* Remove the object from all objects' DAG lists. */
4423     	STAILQ_FOREACH(elm, &root->dagmembers, link) {
4424 	    objlist_remove(&elm->obj->dldags, root);
4425 	    if (elm->obj != root)
4426 		unlink_object(elm->obj);
4427 	}
4428     }
4429 }
4430 
4431 static void
4432 ref_dag(Obj_Entry *root)
4433 {
4434     Objlist_Entry *elm;
4435 
4436     assert(root->dag_inited);
4437     STAILQ_FOREACH(elm, &root->dagmembers, link)
4438 	elm->obj->refcount++;
4439 }
4440 
4441 static void
4442 unref_dag(Obj_Entry *root)
4443 {
4444     Objlist_Entry *elm;
4445 
4446     assert(root->dag_inited);
4447     STAILQ_FOREACH(elm, &root->dagmembers, link)
4448 	elm->obj->refcount--;
4449 }
4450 
4451 /*
4452  * Common code for MD __tls_get_addr().
4453  */
4454 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline;
4455 static void *
4456 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset)
4457 {
4458     Elf_Addr *newdtv, *dtv;
4459     RtldLockState lockstate;
4460     int to_copy;
4461 
4462     dtv = *dtvp;
4463     /* Check dtv generation in case new modules have arrived */
4464     if (dtv[0] != tls_dtv_generation) {
4465 	wlock_acquire(rtld_bind_lock, &lockstate);
4466 	newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4467 	to_copy = dtv[1];
4468 	if (to_copy > tls_max_index)
4469 	    to_copy = tls_max_index;
4470 	memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
4471 	newdtv[0] = tls_dtv_generation;
4472 	newdtv[1] = tls_max_index;
4473 	free(dtv);
4474 	lock_release(rtld_bind_lock, &lockstate);
4475 	dtv = *dtvp = newdtv;
4476     }
4477 
4478     /* Dynamically allocate module TLS if necessary */
4479     if (dtv[index + 1] == 0) {
4480 	/* Signal safe, wlock will block out signals. */
4481 	wlock_acquire(rtld_bind_lock, &lockstate);
4482 	if (!dtv[index + 1])
4483 	    dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
4484 	lock_release(rtld_bind_lock, &lockstate);
4485     }
4486     return ((void *)(dtv[index + 1] + offset));
4487 }
4488 
4489 void *
4490 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset)
4491 {
4492 	Elf_Addr *dtv;
4493 
4494 	dtv = *dtvp;
4495 	/* Check dtv generation in case new modules have arrived */
4496 	if (__predict_true(dtv[0] == tls_dtv_generation &&
4497 	    dtv[index + 1] != 0))
4498 		return ((void *)(dtv[index + 1] + offset));
4499 	return (tls_get_addr_slow(dtvp, index, offset));
4500 }
4501 
4502 #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \
4503     defined(__powerpc__) || defined(__riscv__)
4504 
4505 /*
4506  * Allocate Static TLS using the Variant I method.
4507  */
4508 void *
4509 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
4510 {
4511     Obj_Entry *obj;
4512     char *tcb;
4513     Elf_Addr **tls;
4514     Elf_Addr *dtv;
4515     Elf_Addr addr;
4516     int i;
4517 
4518     if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
4519 	return (oldtcb);
4520 
4521     assert(tcbsize >= TLS_TCB_SIZE);
4522     tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize);
4523     tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
4524 
4525     if (oldtcb != NULL) {
4526 	memcpy(tls, oldtcb, tls_static_space);
4527 	free(oldtcb);
4528 
4529 	/* Adjust the DTV. */
4530 	dtv = tls[0];
4531 	for (i = 0; i < dtv[1]; i++) {
4532 	    if (dtv[i+2] >= (Elf_Addr)oldtcb &&
4533 		dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
4534 		dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls;
4535 	    }
4536 	}
4537     } else {
4538 	dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4539 	tls[0] = dtv;
4540 	dtv[0] = tls_dtv_generation;
4541 	dtv[1] = tls_max_index;
4542 
4543 	for (obj = globallist_curr(objs); obj != NULL;
4544 	  obj = globallist_next(obj)) {
4545 	    if (obj->tlsoffset > 0) {
4546 		addr = (Elf_Addr)tls + obj->tlsoffset;
4547 		if (obj->tlsinitsize > 0)
4548 		    memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
4549 		if (obj->tlssize > obj->tlsinitsize)
4550 		    memset((void*) (addr + obj->tlsinitsize), 0,
4551 			   obj->tlssize - obj->tlsinitsize);
4552 		dtv[obj->tlsindex + 1] = addr;
4553 	    }
4554 	}
4555     }
4556 
4557     return (tcb);
4558 }
4559 
4560 void
4561 free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
4562 {
4563     Elf_Addr *dtv;
4564     Elf_Addr tlsstart, tlsend;
4565     int dtvsize, i;
4566 
4567     assert(tcbsize >= TLS_TCB_SIZE);
4568 
4569     tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE;
4570     tlsend = tlsstart + tls_static_space;
4571 
4572     dtv = *(Elf_Addr **)tlsstart;
4573     dtvsize = dtv[1];
4574     for (i = 0; i < dtvsize; i++) {
4575 	if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
4576 	    free((void*)dtv[i+2]);
4577 	}
4578     }
4579     free(dtv);
4580     free(tcb);
4581 }
4582 
4583 #endif
4584 
4585 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__)
4586 
4587 /*
4588  * Allocate Static TLS using the Variant II method.
4589  */
4590 void *
4591 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
4592 {
4593     Obj_Entry *obj;
4594     size_t size, ralign;
4595     char *tls;
4596     Elf_Addr *dtv, *olddtv;
4597     Elf_Addr segbase, oldsegbase, addr;
4598     int i;
4599 
4600     ralign = tcbalign;
4601     if (tls_static_max_align > ralign)
4602 	    ralign = tls_static_max_align;
4603     size = round(tls_static_space, ralign) + round(tcbsize, ralign);
4604 
4605     assert(tcbsize >= 2*sizeof(Elf_Addr));
4606     tls = malloc_aligned(size, ralign);
4607     dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4608 
4609     segbase = (Elf_Addr)(tls + round(tls_static_space, ralign));
4610     ((Elf_Addr*)segbase)[0] = segbase;
4611     ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
4612 
4613     dtv[0] = tls_dtv_generation;
4614     dtv[1] = tls_max_index;
4615 
4616     if (oldtls) {
4617 	/*
4618 	 * Copy the static TLS block over whole.
4619 	 */
4620 	oldsegbase = (Elf_Addr) oldtls;
4621 	memcpy((void *)(segbase - tls_static_space),
4622 	       (const void *)(oldsegbase - tls_static_space),
4623 	       tls_static_space);
4624 
4625 	/*
4626 	 * If any dynamic TLS blocks have been created tls_get_addr(),
4627 	 * move them over.
4628 	 */
4629 	olddtv = ((Elf_Addr**)oldsegbase)[1];
4630 	for (i = 0; i < olddtv[1]; i++) {
4631 	    if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) {
4632 		dtv[i+2] = olddtv[i+2];
4633 		olddtv[i+2] = 0;
4634 	    }
4635 	}
4636 
4637 	/*
4638 	 * We assume that this block was the one we created with
4639 	 * allocate_initial_tls().
4640 	 */
4641 	free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
4642     } else {
4643 	obj = objs;
4644 	TAILQ_FOREACH_FROM(obj, &obj_list, next) {
4645 		if (obj->marker || obj->tlsoffset == 0)
4646 			continue;
4647 		addr = segbase - obj->tlsoffset;
4648 		memset((void*) (addr + obj->tlsinitsize),
4649 		       0, obj->tlssize - obj->tlsinitsize);
4650 		if (obj->tlsinit)
4651 		    memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
4652 		dtv[obj->tlsindex + 1] = addr;
4653 	}
4654     }
4655 
4656     return (void*) segbase;
4657 }
4658 
4659 void
4660 free_tls(void *tls, size_t tcbsize, size_t tcbalign)
4661 {
4662     Elf_Addr* dtv;
4663     size_t size, ralign;
4664     int dtvsize, i;
4665     Elf_Addr tlsstart, tlsend;
4666 
4667     /*
4668      * Figure out the size of the initial TLS block so that we can
4669      * find stuff which ___tls_get_addr() allocated dynamically.
4670      */
4671     ralign = tcbalign;
4672     if (tls_static_max_align > ralign)
4673 	    ralign = tls_static_max_align;
4674     size = round(tls_static_space, ralign);
4675 
4676     dtv = ((Elf_Addr**)tls)[1];
4677     dtvsize = dtv[1];
4678     tlsend = (Elf_Addr) tls;
4679     tlsstart = tlsend - size;
4680     for (i = 0; i < dtvsize; i++) {
4681 	if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) {
4682 		free_aligned((void *)dtv[i + 2]);
4683 	}
4684     }
4685 
4686     free_aligned((void *)tlsstart);
4687     free((void*) dtv);
4688 }
4689 
4690 #endif
4691 
4692 /*
4693  * Allocate TLS block for module with given index.
4694  */
4695 void *
4696 allocate_module_tls(int index)
4697 {
4698     Obj_Entry* obj;
4699     char* p;
4700 
4701     TAILQ_FOREACH(obj, &obj_list, next) {
4702 	if (obj->marker)
4703 	    continue;
4704 	if (obj->tlsindex == index)
4705 	    break;
4706     }
4707     if (!obj) {
4708 	_rtld_error("Can't find module with TLS index %d", index);
4709 	rtld_die();
4710     }
4711 
4712     p = malloc_aligned(obj->tlssize, obj->tlsalign);
4713     memcpy(p, obj->tlsinit, obj->tlsinitsize);
4714     memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
4715 
4716     return p;
4717 }
4718 
4719 bool
4720 allocate_tls_offset(Obj_Entry *obj)
4721 {
4722     size_t off;
4723 
4724     if (obj->tls_done)
4725 	return true;
4726 
4727     if (obj->tlssize == 0) {
4728 	obj->tls_done = true;
4729 	return true;
4730     }
4731 
4732     if (tls_last_offset == 0)
4733 	off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
4734     else
4735 	off = calculate_tls_offset(tls_last_offset, tls_last_size,
4736 				   obj->tlssize, obj->tlsalign);
4737 
4738     /*
4739      * If we have already fixed the size of the static TLS block, we
4740      * must stay within that size. When allocating the static TLS, we
4741      * leave a small amount of space spare to be used for dynamically
4742      * loading modules which use static TLS.
4743      */
4744     if (tls_static_space != 0) {
4745 	if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
4746 	    return false;
4747     } else if (obj->tlsalign > tls_static_max_align) {
4748 	    tls_static_max_align = obj->tlsalign;
4749     }
4750 
4751     tls_last_offset = obj->tlsoffset = off;
4752     tls_last_size = obj->tlssize;
4753     obj->tls_done = true;
4754 
4755     return true;
4756 }
4757 
4758 void
4759 free_tls_offset(Obj_Entry *obj)
4760 {
4761 
4762     /*
4763      * If we were the last thing to allocate out of the static TLS
4764      * block, we give our space back to the 'allocator'. This is a
4765      * simplistic workaround to allow libGL.so.1 to be loaded and
4766      * unloaded multiple times.
4767      */
4768     if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
4769 	== calculate_tls_end(tls_last_offset, tls_last_size)) {
4770 	tls_last_offset -= obj->tlssize;
4771 	tls_last_size = 0;
4772     }
4773 }
4774 
4775 void *
4776 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
4777 {
4778     void *ret;
4779     RtldLockState lockstate;
4780 
4781     wlock_acquire(rtld_bind_lock, &lockstate);
4782     ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls,
4783       tcbsize, tcbalign);
4784     lock_release(rtld_bind_lock, &lockstate);
4785     return (ret);
4786 }
4787 
4788 void
4789 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
4790 {
4791     RtldLockState lockstate;
4792 
4793     wlock_acquire(rtld_bind_lock, &lockstate);
4794     free_tls(tcb, tcbsize, tcbalign);
4795     lock_release(rtld_bind_lock, &lockstate);
4796 }
4797 
4798 static void
4799 object_add_name(Obj_Entry *obj, const char *name)
4800 {
4801     Name_Entry *entry;
4802     size_t len;
4803 
4804     len = strlen(name);
4805     entry = malloc(sizeof(Name_Entry) + len);
4806 
4807     if (entry != NULL) {
4808 	strcpy(entry->name, name);
4809 	STAILQ_INSERT_TAIL(&obj->names, entry, link);
4810     }
4811 }
4812 
4813 static int
4814 object_match_name(const Obj_Entry *obj, const char *name)
4815 {
4816     Name_Entry *entry;
4817 
4818     STAILQ_FOREACH(entry, &obj->names, link) {
4819 	if (strcmp(name, entry->name) == 0)
4820 	    return (1);
4821     }
4822     return (0);
4823 }
4824 
4825 static Obj_Entry *
4826 locate_dependency(const Obj_Entry *obj, const char *name)
4827 {
4828     const Objlist_Entry *entry;
4829     const Needed_Entry *needed;
4830 
4831     STAILQ_FOREACH(entry, &list_main, link) {
4832 	if (object_match_name(entry->obj, name))
4833 	    return entry->obj;
4834     }
4835 
4836     for (needed = obj->needed;  needed != NULL;  needed = needed->next) {
4837 	if (strcmp(obj->strtab + needed->name, name) == 0 ||
4838 	  (needed->obj != NULL && object_match_name(needed->obj, name))) {
4839 	    /*
4840 	     * If there is DT_NEEDED for the name we are looking for,
4841 	     * we are all set.  Note that object might not be found if
4842 	     * dependency was not loaded yet, so the function can
4843 	     * return NULL here.  This is expected and handled
4844 	     * properly by the caller.
4845 	     */
4846 	    return (needed->obj);
4847 	}
4848     }
4849     _rtld_error("%s: Unexpected inconsistency: dependency %s not found",
4850 	obj->path, name);
4851     rtld_die();
4852 }
4853 
4854 static int
4855 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
4856     const Elf_Vernaux *vna)
4857 {
4858     const Elf_Verdef *vd;
4859     const char *vername;
4860 
4861     vername = refobj->strtab + vna->vna_name;
4862     vd = depobj->verdef;
4863     if (vd == NULL) {
4864 	_rtld_error("%s: version %s required by %s not defined",
4865 	    depobj->path, vername, refobj->path);
4866 	return (-1);
4867     }
4868     for (;;) {
4869 	if (vd->vd_version != VER_DEF_CURRENT) {
4870 	    _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
4871 		depobj->path, vd->vd_version);
4872 	    return (-1);
4873 	}
4874 	if (vna->vna_hash == vd->vd_hash) {
4875 	    const Elf_Verdaux *aux = (const Elf_Verdaux *)
4876 		((char *)vd + vd->vd_aux);
4877 	    if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
4878 		return (0);
4879 	}
4880 	if (vd->vd_next == 0)
4881 	    break;
4882 	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4883     }
4884     if (vna->vna_flags & VER_FLG_WEAK)
4885 	return (0);
4886     _rtld_error("%s: version %s required by %s not found",
4887 	depobj->path, vername, refobj->path);
4888     return (-1);
4889 }
4890 
4891 static int
4892 rtld_verify_object_versions(Obj_Entry *obj)
4893 {
4894     const Elf_Verneed *vn;
4895     const Elf_Verdef  *vd;
4896     const Elf_Verdaux *vda;
4897     const Elf_Vernaux *vna;
4898     const Obj_Entry *depobj;
4899     int maxvernum, vernum;
4900 
4901     if (obj->ver_checked)
4902 	return (0);
4903     obj->ver_checked = true;
4904 
4905     maxvernum = 0;
4906     /*
4907      * Walk over defined and required version records and figure out
4908      * max index used by any of them. Do very basic sanity checking
4909      * while there.
4910      */
4911     vn = obj->verneed;
4912     while (vn != NULL) {
4913 	if (vn->vn_version != VER_NEED_CURRENT) {
4914 	    _rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
4915 		obj->path, vn->vn_version);
4916 	    return (-1);
4917 	}
4918 	vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
4919 	for (;;) {
4920 	    vernum = VER_NEED_IDX(vna->vna_other);
4921 	    if (vernum > maxvernum)
4922 		maxvernum = vernum;
4923 	    if (vna->vna_next == 0)
4924 		 break;
4925 	    vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
4926 	}
4927 	if (vn->vn_next == 0)
4928 	    break;
4929 	vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
4930     }
4931 
4932     vd = obj->verdef;
4933     while (vd != NULL) {
4934 	if (vd->vd_version != VER_DEF_CURRENT) {
4935 	    _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
4936 		obj->path, vd->vd_version);
4937 	    return (-1);
4938 	}
4939 	vernum = VER_DEF_IDX(vd->vd_ndx);
4940 	if (vernum > maxvernum)
4941 		maxvernum = vernum;
4942 	if (vd->vd_next == 0)
4943 	    break;
4944 	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4945     }
4946 
4947     if (maxvernum == 0)
4948 	return (0);
4949 
4950     /*
4951      * Store version information in array indexable by version index.
4952      * Verify that object version requirements are satisfied along the
4953      * way.
4954      */
4955     obj->vernum = maxvernum + 1;
4956     obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry));
4957 
4958     vd = obj->verdef;
4959     while (vd != NULL) {
4960 	if ((vd->vd_flags & VER_FLG_BASE) == 0) {
4961 	    vernum = VER_DEF_IDX(vd->vd_ndx);
4962 	    assert(vernum <= maxvernum);
4963 	    vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux);
4964 	    obj->vertab[vernum].hash = vd->vd_hash;
4965 	    obj->vertab[vernum].name = obj->strtab + vda->vda_name;
4966 	    obj->vertab[vernum].file = NULL;
4967 	    obj->vertab[vernum].flags = 0;
4968 	}
4969 	if (vd->vd_next == 0)
4970 	    break;
4971 	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4972     }
4973 
4974     vn = obj->verneed;
4975     while (vn != NULL) {
4976 	depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
4977 	if (depobj == NULL)
4978 	    return (-1);
4979 	vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
4980 	for (;;) {
4981 	    if (check_object_provided_version(obj, depobj, vna))
4982 		return (-1);
4983 	    vernum = VER_NEED_IDX(vna->vna_other);
4984 	    assert(vernum <= maxvernum);
4985 	    obj->vertab[vernum].hash = vna->vna_hash;
4986 	    obj->vertab[vernum].name = obj->strtab + vna->vna_name;
4987 	    obj->vertab[vernum].file = obj->strtab + vn->vn_file;
4988 	    obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ?
4989 		VER_INFO_HIDDEN : 0;
4990 	    if (vna->vna_next == 0)
4991 		 break;
4992 	    vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
4993 	}
4994 	if (vn->vn_next == 0)
4995 	    break;
4996 	vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
4997     }
4998     return 0;
4999 }
5000 
5001 static int
5002 rtld_verify_versions(const Objlist *objlist)
5003 {
5004     Objlist_Entry *entry;
5005     int rc;
5006 
5007     rc = 0;
5008     STAILQ_FOREACH(entry, objlist, link) {
5009 	/*
5010 	 * Skip dummy objects or objects that have their version requirements
5011 	 * already checked.
5012 	 */
5013 	if (entry->obj->strtab == NULL || entry->obj->vertab != NULL)
5014 	    continue;
5015 	if (rtld_verify_object_versions(entry->obj) == -1) {
5016 	    rc = -1;
5017 	    if (ld_tracing == NULL)
5018 		break;
5019 	}
5020     }
5021     if (rc == 0 || ld_tracing != NULL)
5022     	rc = rtld_verify_object_versions(&obj_rtld);
5023     return rc;
5024 }
5025 
5026 const Ver_Entry *
5027 fetch_ventry(const Obj_Entry *obj, unsigned long symnum)
5028 {
5029     Elf_Versym vernum;
5030 
5031     if (obj->vertab) {
5032 	vernum = VER_NDX(obj->versyms[symnum]);
5033 	if (vernum >= obj->vernum) {
5034 	    _rtld_error("%s: symbol %s has wrong verneed value %d",
5035 		obj->path, obj->strtab + symnum, vernum);
5036 	} else if (obj->vertab[vernum].hash != 0) {
5037 	    return &obj->vertab[vernum];
5038 	}
5039     }
5040     return NULL;
5041 }
5042 
5043 int
5044 _rtld_get_stack_prot(void)
5045 {
5046 
5047 	return (stack_prot);
5048 }
5049 
5050 int
5051 _rtld_is_dlopened(void *arg)
5052 {
5053 	Obj_Entry *obj;
5054 	RtldLockState lockstate;
5055 	int res;
5056 
5057 	rlock_acquire(rtld_bind_lock, &lockstate);
5058 	obj = dlcheck(arg);
5059 	if (obj == NULL)
5060 		obj = obj_from_addr(arg);
5061 	if (obj == NULL) {
5062 		_rtld_error("No shared object contains address");
5063 		lock_release(rtld_bind_lock, &lockstate);
5064 		return (-1);
5065 	}
5066 	res = obj->dlopened ? 1 : 0;
5067 	lock_release(rtld_bind_lock, &lockstate);
5068 	return (res);
5069 }
5070 
5071 static void
5072 map_stacks_exec(RtldLockState *lockstate)
5073 {
5074 	void (*thr_map_stacks_exec)(void);
5075 
5076 	if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0)
5077 		return;
5078 	thr_map_stacks_exec = (void (*)(void))(uintptr_t)
5079 	    get_program_var_addr("__pthread_map_stacks_exec", lockstate);
5080 	if (thr_map_stacks_exec != NULL) {
5081 		stack_prot |= PROT_EXEC;
5082 		thr_map_stacks_exec();
5083 	}
5084 }
5085 
5086 void
5087 symlook_init(SymLook *dst, const char *name)
5088 {
5089 
5090 	bzero(dst, sizeof(*dst));
5091 	dst->name = name;
5092 	dst->hash = elf_hash(name);
5093 	dst->hash_gnu = gnu_hash(name);
5094 }
5095 
5096 static void
5097 symlook_init_from_req(SymLook *dst, const SymLook *src)
5098 {
5099 
5100 	dst->name = src->name;
5101 	dst->hash = src->hash;
5102 	dst->hash_gnu = src->hash_gnu;
5103 	dst->ventry = src->ventry;
5104 	dst->flags = src->flags;
5105 	dst->defobj_out = NULL;
5106 	dst->sym_out = NULL;
5107 	dst->lockstate = src->lockstate;
5108 }
5109 
5110 
5111 /*
5112  * Parse a file descriptor number without pulling in more of libc (e.g. atoi).
5113  */
5114 static int
5115 parse_libdir(const char *str)
5116 {
5117 	static const int RADIX = 10;  /* XXXJA: possibly support hex? */
5118 	const char *orig;
5119 	int fd;
5120 	char c;
5121 
5122 	orig = str;
5123 	fd = 0;
5124 	for (c = *str; c != '\0'; c = *++str) {
5125 		if (c < '0' || c > '9')
5126 			return (-1);
5127 
5128 		fd *= RADIX;
5129 		fd += c - '0';
5130 	}
5131 
5132 	/* Make sure we actually parsed something. */
5133 	if (str == orig) {
5134 		_rtld_error("failed to parse directory FD from '%s'", str);
5135 		return (-1);
5136 	}
5137 	return (fd);
5138 }
5139 
5140 /*
5141  * Overrides for libc_pic-provided functions.
5142  */
5143 
5144 int
5145 __getosreldate(void)
5146 {
5147 	size_t len;
5148 	int oid[2];
5149 	int error, osrel;
5150 
5151 	if (osreldate != 0)
5152 		return (osreldate);
5153 
5154 	oid[0] = CTL_KERN;
5155 	oid[1] = KERN_OSRELDATE;
5156 	osrel = 0;
5157 	len = sizeof(osrel);
5158 	error = sysctl(oid, 2, &osrel, &len, NULL, 0);
5159 	if (error == 0 && osrel > 0 && len == sizeof(osrel))
5160 		osreldate = osrel;
5161 	return (osreldate);
5162 }
5163 
5164 void
5165 exit(int status)
5166 {
5167 
5168 	_exit(status);
5169 }
5170 
5171 void (*__cleanup)(void);
5172 int __isthreaded = 0;
5173 int _thread_autoinit_dummy_decl = 1;
5174 
5175 /*
5176  * No unresolved symbols for rtld.
5177  */
5178 void
5179 __pthread_cxa_finalize(struct dl_phdr_info *a)
5180 {
5181 }
5182 
5183 void
5184 __stack_chk_fail(void)
5185 {
5186 
5187 	_rtld_error("stack overflow detected; terminated");
5188 	rtld_die();
5189 }
5190 __weak_reference(__stack_chk_fail, __stack_chk_fail_local);
5191 
5192 void
5193 __chk_fail(void)
5194 {
5195 
5196 	_rtld_error("buffer overflow detected; terminated");
5197 	rtld_die();
5198 }
5199 
5200 const char *
5201 rtld_strerror(int errnum)
5202 {
5203 
5204 	if (errnum < 0 || errnum >= sys_nerr)
5205 		return ("Unknown error");
5206 	return (sys_errlist[errnum]);
5207 }
5208