xref: /freebsd/libexec/rtld-elf/rtld.c (revision 5608fd23c27fa1e8ee595d7b678cbfd35d657fbe)
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 #ifndef __GNUC__
38 #error "GCC is needed to compile this file"
39 #endif
40 
41 #include <sys/param.h>
42 #include <sys/mount.h>
43 #include <sys/mman.h>
44 #include <sys/stat.h>
45 #include <sys/sysctl.h>
46 #include <sys/uio.h>
47 #include <sys/utsname.h>
48 #include <sys/ktrace.h>
49 
50 #include <dlfcn.h>
51 #include <err.h>
52 #include <errno.h>
53 #include <fcntl.h>
54 #include <stdarg.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59 
60 #include "debug.h"
61 #include "rtld.h"
62 #include "libmap.h"
63 #include "rtld_tls.h"
64 #include "rtld_printf.h"
65 #include "notes.h"
66 
67 #ifndef COMPAT_32BIT
68 #define PATH_RTLD	"/libexec/ld-elf.so.1"
69 #else
70 #define PATH_RTLD	"/libexec/ld-elf32.so.1"
71 #endif
72 
73 /* Types. */
74 typedef void (*func_ptr_type)();
75 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
76 
77 /*
78  * Function declarations.
79  */
80 static const char *basename(const char *);
81 static void die(void) __dead2;
82 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
83     const Elf_Dyn **, const Elf_Dyn **);
84 static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *,
85     const Elf_Dyn *);
86 static void digest_dynamic(Obj_Entry *, int);
87 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
88 static Obj_Entry *dlcheck(void *);
89 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj,
90     int lo_flags, int mode, RtldLockState *lockstate);
91 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
92 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
93 static bool donelist_check(DoneList *, const Obj_Entry *);
94 static void errmsg_restore(char *);
95 static char *errmsg_save(void);
96 static void *fill_search_info(const char *, size_t, void *);
97 static char *find_library(const char *, const Obj_Entry *, int *);
98 static const char *gethints(bool);
99 static void init_dag(Obj_Entry *);
100 static void init_pagesizes(Elf_Auxinfo **aux_info);
101 static void init_rtld(caddr_t, Elf_Auxinfo **);
102 static void initlist_add_neededs(Needed_Entry *, Objlist *);
103 static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
104 static void linkmap_add(Obj_Entry *);
105 static void linkmap_delete(Obj_Entry *);
106 static void load_filtees(Obj_Entry *, int flags, RtldLockState *);
107 static void unload_filtees(Obj_Entry *);
108 static int load_needed_objects(Obj_Entry *, int);
109 static int load_preload_objects(void);
110 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int);
111 static void map_stacks_exec(RtldLockState *);
112 static Obj_Entry *obj_from_addr(const void *);
113 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
114 static void objlist_call_init(Objlist *, RtldLockState *);
115 static void objlist_clear(Objlist *);
116 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
117 static void objlist_init(Objlist *);
118 static void objlist_push_head(Objlist *, Obj_Entry *);
119 static void objlist_push_tail(Objlist *, Obj_Entry *);
120 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *);
121 static void objlist_remove(Objlist *, Obj_Entry *);
122 static int parse_libdir(const char *);
123 static void *path_enumerate(const char *, path_enum_proc, void *);
124 static int relocate_object_dag(Obj_Entry *root, bool bind_now,
125     Obj_Entry *rtldobj, int flags, RtldLockState *lockstate);
126 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
127     int flags, RtldLockState *lockstate);
128 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int,
129     RtldLockState *);
130 static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now,
131     int flags, RtldLockState *lockstate);
132 static int rtld_dirname(const char *, char *);
133 static int rtld_dirname_abs(const char *, char *);
134 static void *rtld_dlopen(const char *name, int fd, int mode);
135 static void rtld_exit(void);
136 static char *search_library_path(const char *, const char *);
137 static char *search_library_pathfds(const char *, const char *, int *);
138 static const void **get_program_var_addr(const char *, RtldLockState *);
139 static void set_program_var(const char *, const void *);
140 static int symlook_default(SymLook *, const Obj_Entry *refobj);
141 static int symlook_global(SymLook *, DoneList *);
142 static void symlook_init_from_req(SymLook *, const SymLook *);
143 static int symlook_list(SymLook *, const Objlist *, DoneList *);
144 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *);
145 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *);
146 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *);
147 static void trace_loaded_objects(Obj_Entry *);
148 static void unlink_object(Obj_Entry *);
149 static void unload_object(Obj_Entry *);
150 static void unref_dag(Obj_Entry *);
151 static void ref_dag(Obj_Entry *);
152 static char *origin_subst_one(char *, const char *, const char *, bool);
153 static char *origin_subst(char *, const char *);
154 static void preinit_main(void);
155 static int  rtld_verify_versions(const Objlist *);
156 static int  rtld_verify_object_versions(Obj_Entry *);
157 static void object_add_name(Obj_Entry *, const char *);
158 static int  object_match_name(const Obj_Entry *, const char *);
159 static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
160 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
161     struct dl_phdr_info *phdr_info);
162 static uint32_t gnu_hash(const char *);
163 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *,
164     const unsigned long);
165 
166 void r_debug_state(struct r_debug *, struct link_map *) __noinline;
167 void _r_debug_postinit(struct link_map *) __noinline;
168 
169 /*
170  * Data declarations.
171  */
172 static char *error_message;	/* Message for dlerror(), or NULL */
173 struct r_debug r_debug;		/* for GDB; */
174 static bool libmap_disable;	/* Disable libmap */
175 static bool ld_loadfltr;	/* Immediate filters processing */
176 static char *libmap_override;	/* Maps to use in addition to libmap.conf */
177 static bool trust;		/* False for setuid and setgid programs */
178 static bool dangerous_ld_env;	/* True if environment variables have been
179 				   used to affect the libraries loaded */
180 static char *ld_bind_now;	/* Environment variable for immediate binding */
181 static char *ld_debug;		/* Environment variable for debugging */
182 static char *ld_library_path;	/* Environment variable for search path */
183 static char *ld_library_dirs;	/* Environment variable for library descriptors */
184 static char *ld_preload;	/* Environment variable for libraries to
185 				   load first */
186 static char *ld_elf_hints_path;	/* Environment variable for alternative hints path */
187 static char *ld_tracing;	/* Called from ldd to print libs */
188 static char *ld_utrace;		/* Use utrace() to log events. */
189 static Obj_Entry *obj_list;	/* Head of linked list of shared objects */
190 static Obj_Entry **obj_tail;	/* Link field of last object in list */
191 static Obj_Entry *obj_main;	/* The main program shared object */
192 static Obj_Entry obj_rtld;	/* The dynamic linker shared object */
193 static unsigned int obj_count;	/* Number of objects in obj_list */
194 static unsigned int obj_loads;	/* Number of objects in obj_list */
195 
196 static Objlist list_global =	/* Objects dlopened with RTLD_GLOBAL */
197   STAILQ_HEAD_INITIALIZER(list_global);
198 static Objlist list_main =	/* Objects loaded at program startup */
199   STAILQ_HEAD_INITIALIZER(list_main);
200 static Objlist list_fini =	/* Objects needing fini() calls */
201   STAILQ_HEAD_INITIALIZER(list_fini);
202 
203 Elf_Sym sym_zero;		/* For resolving undefined weak refs. */
204 
205 #define GDB_STATE(s,m)	r_debug.r_state = s; r_debug_state(&r_debug,m);
206 
207 extern Elf_Dyn _DYNAMIC;
208 #pragma weak _DYNAMIC
209 #ifndef RTLD_IS_DYNAMIC
210 #define	RTLD_IS_DYNAMIC()	(&_DYNAMIC != NULL)
211 #endif
212 
213 int npagesizes, osreldate;
214 size_t *pagesizes;
215 
216 long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
217 
218 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC;
219 static int max_stack_flags;
220 
221 /*
222  * Global declarations normally provided by crt1.  The dynamic linker is
223  * not built with crt1, so we have to provide them ourselves.
224  */
225 char *__progname;
226 char **environ;
227 
228 /*
229  * Used to pass argc, argv to init functions.
230  */
231 int main_argc;
232 char **main_argv;
233 
234 /*
235  * Globals to control TLS allocation.
236  */
237 size_t tls_last_offset;		/* Static TLS offset of last module */
238 size_t tls_last_size;		/* Static TLS size of last module */
239 size_t tls_static_space;	/* Static TLS space allocated */
240 size_t tls_static_max_align;
241 int tls_dtv_generation = 1;	/* Used to detect when dtv size changes  */
242 int tls_max_index = 1;		/* Largest module index allocated */
243 
244 bool ld_library_path_rpath = false;
245 
246 /*
247  * Fill in a DoneList with an allocation large enough to hold all of
248  * the currently-loaded objects.  Keep this as a macro since it calls
249  * alloca and we want that to occur within the scope of the caller.
250  */
251 #define donelist_init(dlp)					\
252     ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]),	\
253     assert((dlp)->objs != NULL),				\
254     (dlp)->num_alloc = obj_count,				\
255     (dlp)->num_used = 0)
256 
257 #define	UTRACE_DLOPEN_START		1
258 #define	UTRACE_DLOPEN_STOP		2
259 #define	UTRACE_DLCLOSE_START		3
260 #define	UTRACE_DLCLOSE_STOP		4
261 #define	UTRACE_LOAD_OBJECT		5
262 #define	UTRACE_UNLOAD_OBJECT		6
263 #define	UTRACE_ADD_RUNDEP		7
264 #define	UTRACE_PRELOAD_FINISHED		8
265 #define	UTRACE_INIT_CALL		9
266 #define	UTRACE_FINI_CALL		10
267 
268 struct utrace_rtld {
269 	char sig[4];			/* 'RTLD' */
270 	int event;
271 	void *handle;
272 	void *mapbase;			/* Used for 'parent' and 'init/fini' */
273 	size_t mapsize;
274 	int refcnt;			/* Used for 'mode' */
275 	char name[MAXPATHLEN];
276 };
277 
278 #define	LD_UTRACE(e, h, mb, ms, r, n) do {			\
279 	if (ld_utrace != NULL)					\
280 		ld_utrace_log(e, h, mb, ms, r, n);		\
281 } while (0)
282 
283 static void
284 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
285     int refcnt, const char *name)
286 {
287 	struct utrace_rtld ut;
288 
289 	ut.sig[0] = 'R';
290 	ut.sig[1] = 'T';
291 	ut.sig[2] = 'L';
292 	ut.sig[3] = 'D';
293 	ut.event = event;
294 	ut.handle = handle;
295 	ut.mapbase = mapbase;
296 	ut.mapsize = mapsize;
297 	ut.refcnt = refcnt;
298 	bzero(ut.name, sizeof(ut.name));
299 	if (name)
300 		strlcpy(ut.name, name, sizeof(ut.name));
301 	utrace(&ut, sizeof(ut));
302 }
303 
304 /*
305  * Main entry point for dynamic linking.  The first argument is the
306  * stack pointer.  The stack is expected to be laid out as described
307  * in the SVR4 ABI specification, Intel 386 Processor Supplement.
308  * Specifically, the stack pointer points to a word containing
309  * ARGC.  Following that in the stack is a null-terminated sequence
310  * of pointers to argument strings.  Then comes a null-terminated
311  * sequence of pointers to environment strings.  Finally, there is a
312  * sequence of "auxiliary vector" entries.
313  *
314  * The second argument points to a place to store the dynamic linker's
315  * exit procedure pointer and the third to a place to store the main
316  * program's object.
317  *
318  * The return value is the main program's entry point.
319  */
320 func_ptr_type
321 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
322 {
323     Elf_Auxinfo *aux_info[AT_COUNT];
324     int i;
325     int argc;
326     char **argv;
327     char **env;
328     Elf_Auxinfo *aux;
329     Elf_Auxinfo *auxp;
330     const char *argv0;
331     Objlist_Entry *entry;
332     Obj_Entry *obj;
333     Obj_Entry **preload_tail;
334     Obj_Entry *last_interposer;
335     Objlist initlist;
336     RtldLockState lockstate;
337     char *library_path_rpath;
338     int mib[2];
339     size_t len;
340 
341     /*
342      * On entry, the dynamic linker itself has not been relocated yet.
343      * Be very careful not to reference any global data until after
344      * init_rtld has returned.  It is OK to reference file-scope statics
345      * and string constants, and to call static and global functions.
346      */
347 
348     /* Find the auxiliary vector on the stack. */
349     argc = *sp++;
350     argv = (char **) sp;
351     sp += argc + 1;	/* Skip over arguments and NULL terminator */
352     env = (char **) sp;
353     while (*sp++ != 0)	/* Skip over environment, and NULL terminator */
354 	;
355     aux = (Elf_Auxinfo *) sp;
356 
357     /* Digest the auxiliary vector. */
358     for (i = 0;  i < AT_COUNT;  i++)
359 	aux_info[i] = NULL;
360     for (auxp = aux;  auxp->a_type != AT_NULL;  auxp++) {
361 	if (auxp->a_type < AT_COUNT)
362 	    aux_info[auxp->a_type] = auxp;
363     }
364 
365     /* Initialize and relocate ourselves. */
366     assert(aux_info[AT_BASE] != NULL);
367     init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
368 
369     __progname = obj_rtld.path;
370     argv0 = argv[0] != NULL ? argv[0] : "(null)";
371     environ = env;
372     main_argc = argc;
373     main_argv = argv;
374 
375     if (aux_info[AT_CANARY] != NULL &&
376 	aux_info[AT_CANARY]->a_un.a_ptr != NULL) {
377 	    i = aux_info[AT_CANARYLEN]->a_un.a_val;
378 	    if (i > sizeof(__stack_chk_guard))
379 		    i = sizeof(__stack_chk_guard);
380 	    memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i);
381     } else {
382 	mib[0] = CTL_KERN;
383 	mib[1] = KERN_ARND;
384 
385 	len = sizeof(__stack_chk_guard);
386 	if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 ||
387 	    len != sizeof(__stack_chk_guard)) {
388 		/* If sysctl was unsuccessful, use the "terminator canary". */
389 		((unsigned char *)(void *)__stack_chk_guard)[0] = 0;
390 		((unsigned char *)(void *)__stack_chk_guard)[1] = 0;
391 		((unsigned char *)(void *)__stack_chk_guard)[2] = '\n';
392 		((unsigned char *)(void *)__stack_chk_guard)[3] = 255;
393 	}
394     }
395 
396     trust = !issetugid();
397 
398     ld_bind_now = getenv(LD_ "BIND_NOW");
399     /*
400      * If the process is tainted, then we un-set the dangerous environment
401      * variables.  The process will be marked as tainted until setuid(2)
402      * is called.  If any child process calls setuid(2) we do not want any
403      * future processes to honor the potentially un-safe variables.
404      */
405     if (!trust) {
406         if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") ||
407 	    unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBRARY_PATH_FDS") ||
408 	    unsetenv(LD_ "LIBMAP_DISABLE") ||
409 	    unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") ||
410 	    unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) {
411 		_rtld_error("environment corrupt; aborting");
412 		die();
413 	}
414     }
415     ld_debug = getenv(LD_ "DEBUG");
416     libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL;
417     libmap_override = getenv(LD_ "LIBMAP");
418     ld_library_path = getenv(LD_ "LIBRARY_PATH");
419     ld_library_dirs = getenv(LD_ "LIBRARY_PATH_FDS");
420     ld_preload = getenv(LD_ "PRELOAD");
421     ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH");
422     ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL;
423     library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH");
424     if (library_path_rpath != NULL) {
425 	    if (library_path_rpath[0] == 'y' ||
426 		library_path_rpath[0] == 'Y' ||
427 		library_path_rpath[0] == '1')
428 		    ld_library_path_rpath = true;
429 	    else
430 		    ld_library_path_rpath = false;
431     }
432     dangerous_ld_env = libmap_disable || (libmap_override != NULL) ||
433 	(ld_library_path != NULL) || (ld_preload != NULL) ||
434 	(ld_elf_hints_path != NULL) || ld_loadfltr;
435     ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS");
436     ld_utrace = getenv(LD_ "UTRACE");
437 
438     if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
439 	ld_elf_hints_path = _PATH_ELF_HINTS;
440 
441     if (ld_debug != NULL && *ld_debug != '\0')
442 	debug = 1;
443     dbg("%s is initialized, base address = %p", __progname,
444 	(caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
445     dbg("RTLD dynamic = %p", obj_rtld.dynamic);
446     dbg("RTLD pltgot  = %p", obj_rtld.pltgot);
447 
448     dbg("initializing thread locks");
449     lockdflt_init();
450 
451     /*
452      * Load the main program, or process its program header if it is
453      * already loaded.
454      */
455     if (aux_info[AT_EXECFD] != NULL) {	/* Load the main program. */
456 	int fd = aux_info[AT_EXECFD]->a_un.a_val;
457 	dbg("loading main program");
458 	obj_main = map_object(fd, argv0, NULL);
459 	close(fd);
460 	if (obj_main == NULL)
461 	    die();
462 	max_stack_flags = obj->stack_flags;
463     } else {				/* Main program already loaded. */
464 	const Elf_Phdr *phdr;
465 	int phnum;
466 	caddr_t entry;
467 
468 	dbg("processing main program's program header");
469 	assert(aux_info[AT_PHDR] != NULL);
470 	phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
471 	assert(aux_info[AT_PHNUM] != NULL);
472 	phnum = aux_info[AT_PHNUM]->a_un.a_val;
473 	assert(aux_info[AT_PHENT] != NULL);
474 	assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
475 	assert(aux_info[AT_ENTRY] != NULL);
476 	entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
477 	if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
478 	    die();
479     }
480 
481     if (aux_info[AT_EXECPATH] != 0) {
482 	    char *kexecpath;
483 	    char buf[MAXPATHLEN];
484 
485 	    kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
486 	    dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
487 	    if (kexecpath[0] == '/')
488 		    obj_main->path = kexecpath;
489 	    else if (getcwd(buf, sizeof(buf)) == NULL ||
490 		     strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
491 		     strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
492 		    obj_main->path = xstrdup(argv0);
493 	    else
494 		    obj_main->path = xstrdup(buf);
495     } else {
496 	    dbg("No AT_EXECPATH");
497 	    obj_main->path = xstrdup(argv0);
498     }
499     dbg("obj_main path %s", obj_main->path);
500     obj_main->mainprog = true;
501 
502     if (aux_info[AT_STACKPROT] != NULL &&
503       aux_info[AT_STACKPROT]->a_un.a_val != 0)
504 	    stack_prot = aux_info[AT_STACKPROT]->a_un.a_val;
505 
506     /*
507      * Get the actual dynamic linker pathname from the executable if
508      * possible.  (It should always be possible.)  That ensures that
509      * gdb will find the right dynamic linker even if a non-standard
510      * one is being used.
511      */
512     if (obj_main->interp != NULL &&
513       strcmp(obj_main->interp, obj_rtld.path) != 0) {
514 	free(obj_rtld.path);
515 	obj_rtld.path = xstrdup(obj_main->interp);
516         __progname = obj_rtld.path;
517     }
518 
519     digest_dynamic(obj_main, 0);
520     dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d",
521 	obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu,
522 	obj_main->dynsymcount);
523 
524     linkmap_add(obj_main);
525     linkmap_add(&obj_rtld);
526 
527     /* Link the main program into the list of objects. */
528     *obj_tail = obj_main;
529     obj_tail = &obj_main->next;
530     obj_count++;
531     obj_loads++;
532 
533     /* Initialize a fake symbol for resolving undefined weak references. */
534     sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
535     sym_zero.st_shndx = SHN_UNDEF;
536     sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
537 
538     if (!libmap_disable)
539         libmap_disable = (bool)lm_init(libmap_override);
540 
541     dbg("loading LD_PRELOAD libraries");
542     if (load_preload_objects() == -1)
543 	die();
544     preload_tail = obj_tail;
545 
546     dbg("loading needed objects");
547     if (load_needed_objects(obj_main, 0) == -1)
548 	die();
549 
550     /* Make a list of all objects loaded at startup. */
551     last_interposer = obj_main;
552     for (obj = obj_list;  obj != NULL;  obj = obj->next) {
553 	if (obj->z_interpose && obj != obj_main) {
554 	    objlist_put_after(&list_main, last_interposer, obj);
555 	    last_interposer = obj;
556 	} else {
557 	    objlist_push_tail(&list_main, obj);
558 	}
559     	obj->refcount++;
560     }
561 
562     dbg("checking for required versions");
563     if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
564 	die();
565 
566     if (ld_tracing) {		/* We're done */
567 	trace_loaded_objects(obj_main);
568 	exit(0);
569     }
570 
571     if (getenv(LD_ "DUMP_REL_PRE") != NULL) {
572        dump_relocations(obj_main);
573        exit (0);
574     }
575 
576     /*
577      * Processing tls relocations requires having the tls offsets
578      * initialized.  Prepare offsets before starting initial
579      * relocation processing.
580      */
581     dbg("initializing initial thread local storage offsets");
582     STAILQ_FOREACH(entry, &list_main, link) {
583 	/*
584 	 * Allocate all the initial objects out of the static TLS
585 	 * block even if they didn't ask for it.
586 	 */
587 	allocate_tls_offset(entry->obj);
588     }
589 
590     if (relocate_objects(obj_main,
591       ld_bind_now != NULL && *ld_bind_now != '\0',
592       &obj_rtld, SYMLOOK_EARLY, NULL) == -1)
593 	die();
594 
595     dbg("doing copy relocations");
596     if (do_copy_relocations(obj_main) == -1)
597 	die();
598 
599     if (getenv(LD_ "DUMP_REL_POST") != NULL) {
600        dump_relocations(obj_main);
601        exit (0);
602     }
603 
604     /*
605      * Setup TLS for main thread.  This must be done after the
606      * relocations are processed, since tls initialization section
607      * might be the subject for relocations.
608      */
609     dbg("initializing initial thread local storage");
610     allocate_initial_tls(obj_list);
611 
612     dbg("initializing key program variables");
613     set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
614     set_program_var("environ", env);
615     set_program_var("__elf_aux_vector", aux);
616 
617     /* Make a list of init functions to call. */
618     objlist_init(&initlist);
619     initlist_add_objects(obj_list, preload_tail, &initlist);
620 
621     r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
622 
623     map_stacks_exec(NULL);
624 
625     dbg("resolving ifuncs");
626     if (resolve_objects_ifunc(obj_main,
627       ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY,
628       NULL) == -1)
629 	die();
630 
631     if (!obj_main->crt_no_init) {
632 	/*
633 	 * Make sure we don't call the main program's init and fini
634 	 * functions for binaries linked with old crt1 which calls
635 	 * _init itself.
636 	 */
637 	obj_main->init = obj_main->fini = (Elf_Addr)NULL;
638 	obj_main->preinit_array = obj_main->init_array =
639 	    obj_main->fini_array = (Elf_Addr)NULL;
640     }
641 
642     wlock_acquire(rtld_bind_lock, &lockstate);
643     if (obj_main->crt_no_init)
644 	preinit_main();
645     objlist_call_init(&initlist, &lockstate);
646     _r_debug_postinit(&obj_main->linkmap);
647     objlist_clear(&initlist);
648     dbg("loading filtees");
649     for (obj = obj_list->next; obj != NULL; obj = obj->next) {
650 	if (ld_loadfltr || obj->z_loadfltr)
651 	    load_filtees(obj, 0, &lockstate);
652     }
653     lock_release(rtld_bind_lock, &lockstate);
654 
655     dbg("transferring control to program entry point = %p", obj_main->entry);
656 
657     /* Return the exit procedure and the program entry point. */
658     *exit_proc = rtld_exit;
659     *objp = obj_main;
660     return (func_ptr_type) obj_main->entry;
661 }
662 
663 void *
664 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def)
665 {
666 	void *ptr;
667 	Elf_Addr target;
668 
669 	ptr = (void *)make_function_pointer(def, obj);
670 	target = ((Elf_Addr (*)(void))ptr)();
671 	return ((void *)target);
672 }
673 
674 Elf_Addr
675 _rtld_bind(Obj_Entry *obj, Elf_Size reloff)
676 {
677     const Elf_Rel *rel;
678     const Elf_Sym *def;
679     const Obj_Entry *defobj;
680     Elf_Addr *where;
681     Elf_Addr target;
682     RtldLockState lockstate;
683 
684     rlock_acquire(rtld_bind_lock, &lockstate);
685     if (sigsetjmp(lockstate.env, 0) != 0)
686 	    lock_upgrade(rtld_bind_lock, &lockstate);
687     if (obj->pltrel)
688 	rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
689     else
690 	rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
691 
692     where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
693     def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL,
694 	&lockstate);
695     if (def == NULL)
696 	die();
697     if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
698 	target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
699     else
700 	target = (Elf_Addr)(defobj->relocbase + def->st_value);
701 
702     dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
703       defobj->strtab + def->st_name, basename(obj->path),
704       (void *)target, basename(defobj->path));
705 
706     /*
707      * Write the new contents for the jmpslot. Note that depending on
708      * architecture, the value which we need to return back to the
709      * lazy binding trampoline may or may not be the target
710      * address. The value returned from reloc_jmpslot() is the value
711      * that the trampoline needs.
712      */
713     target = reloc_jmpslot(where, target, defobj, obj, rel);
714     lock_release(rtld_bind_lock, &lockstate);
715     return target;
716 }
717 
718 /*
719  * Error reporting function.  Use it like printf.  If formats the message
720  * into a buffer, and sets things up so that the next call to dlerror()
721  * will return the message.
722  */
723 void
724 _rtld_error(const char *fmt, ...)
725 {
726     static char buf[512];
727     va_list ap;
728 
729     va_start(ap, fmt);
730     rtld_vsnprintf(buf, sizeof buf, fmt, ap);
731     error_message = buf;
732     va_end(ap);
733 }
734 
735 /*
736  * Return a dynamically-allocated copy of the current error message, if any.
737  */
738 static char *
739 errmsg_save(void)
740 {
741     return error_message == NULL ? NULL : xstrdup(error_message);
742 }
743 
744 /*
745  * Restore the current error message from a copy which was previously saved
746  * by errmsg_save().  The copy is freed.
747  */
748 static void
749 errmsg_restore(char *saved_msg)
750 {
751     if (saved_msg == NULL)
752 	error_message = NULL;
753     else {
754 	_rtld_error("%s", saved_msg);
755 	free(saved_msg);
756     }
757 }
758 
759 static const char *
760 basename(const char *name)
761 {
762     const char *p = strrchr(name, '/');
763     return p != NULL ? p + 1 : name;
764 }
765 
766 static struct utsname uts;
767 
768 static char *
769 origin_subst_one(char *real, const char *kw, const char *subst,
770     bool may_free)
771 {
772 	char *p, *p1, *res, *resp;
773 	int subst_len, kw_len, subst_count, old_len, new_len;
774 
775 	kw_len = strlen(kw);
776 
777 	/*
778 	 * First, count the number of the keyword occurences, to
779 	 * preallocate the final string.
780 	 */
781 	for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) {
782 		p1 = strstr(p, kw);
783 		if (p1 == NULL)
784 			break;
785 	}
786 
787 	/*
788 	 * If the keyword is not found, just return.
789 	 */
790 	if (subst_count == 0)
791 		return (may_free ? real : xstrdup(real));
792 
793 	/*
794 	 * There is indeed something to substitute.  Calculate the
795 	 * length of the resulting string, and allocate it.
796 	 */
797 	subst_len = strlen(subst);
798 	old_len = strlen(real);
799 	new_len = old_len + (subst_len - kw_len) * subst_count;
800 	res = xmalloc(new_len + 1);
801 
802 	/*
803 	 * Now, execute the substitution loop.
804 	 */
805 	for (p = real, resp = res, *resp = '\0';;) {
806 		p1 = strstr(p, kw);
807 		if (p1 != NULL) {
808 			/* Copy the prefix before keyword. */
809 			memcpy(resp, p, p1 - p);
810 			resp += p1 - p;
811 			/* Keyword replacement. */
812 			memcpy(resp, subst, subst_len);
813 			resp += subst_len;
814 			*resp = '\0';
815 			p = p1 + kw_len;
816 		} else
817 			break;
818 	}
819 
820 	/* Copy to the end of string and finish. */
821 	strcat(resp, p);
822 	if (may_free)
823 		free(real);
824 	return (res);
825 }
826 
827 static char *
828 origin_subst(char *real, const char *origin_path)
829 {
830 	char *res1, *res2, *res3, *res4;
831 
832 	if (uts.sysname[0] == '\0') {
833 		if (uname(&uts) != 0) {
834 			_rtld_error("utsname failed: %d", errno);
835 			return (NULL);
836 		}
837 	}
838 	res1 = origin_subst_one(real, "$ORIGIN", origin_path, false);
839 	res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true);
840 	res3 = origin_subst_one(res2, "$OSREL", uts.release, true);
841 	res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true);
842 	return (res4);
843 }
844 
845 static void
846 die(void)
847 {
848     const char *msg = dlerror();
849 
850     if (msg == NULL)
851 	msg = "Fatal error";
852     rtld_fdputstr(STDERR_FILENO, msg);
853     rtld_fdputchar(STDERR_FILENO, '\n');
854     _exit(1);
855 }
856 
857 /*
858  * Process a shared object's DYNAMIC section, and save the important
859  * information in its Obj_Entry structure.
860  */
861 static void
862 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
863     const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath)
864 {
865     const Elf_Dyn *dynp;
866     Needed_Entry **needed_tail = &obj->needed;
867     Needed_Entry **needed_filtees_tail = &obj->needed_filtees;
868     Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees;
869     const Elf_Hashelt *hashtab;
870     const Elf32_Word *hashval;
871     Elf32_Word bkt, nmaskwords;
872     int bloom_size32;
873     bool nmw_power2;
874     int plttype = DT_REL;
875 
876     *dyn_rpath = NULL;
877     *dyn_soname = NULL;
878     *dyn_runpath = NULL;
879 
880     obj->bind_now = false;
881     for (dynp = obj->dynamic;  dynp->d_tag != DT_NULL;  dynp++) {
882 	switch (dynp->d_tag) {
883 
884 	case DT_REL:
885 	    obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
886 	    break;
887 
888 	case DT_RELSZ:
889 	    obj->relsize = dynp->d_un.d_val;
890 	    break;
891 
892 	case DT_RELENT:
893 	    assert(dynp->d_un.d_val == sizeof(Elf_Rel));
894 	    break;
895 
896 	case DT_JMPREL:
897 	    obj->pltrel = (const Elf_Rel *)
898 	      (obj->relocbase + dynp->d_un.d_ptr);
899 	    break;
900 
901 	case DT_PLTRELSZ:
902 	    obj->pltrelsize = dynp->d_un.d_val;
903 	    break;
904 
905 	case DT_RELA:
906 	    obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
907 	    break;
908 
909 	case DT_RELASZ:
910 	    obj->relasize = dynp->d_un.d_val;
911 	    break;
912 
913 	case DT_RELAENT:
914 	    assert(dynp->d_un.d_val == sizeof(Elf_Rela));
915 	    break;
916 
917 	case DT_PLTREL:
918 	    plttype = dynp->d_un.d_val;
919 	    assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
920 	    break;
921 
922 	case DT_SYMTAB:
923 	    obj->symtab = (const Elf_Sym *)
924 	      (obj->relocbase + dynp->d_un.d_ptr);
925 	    break;
926 
927 	case DT_SYMENT:
928 	    assert(dynp->d_un.d_val == sizeof(Elf_Sym));
929 	    break;
930 
931 	case DT_STRTAB:
932 	    obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
933 	    break;
934 
935 	case DT_STRSZ:
936 	    obj->strsize = dynp->d_un.d_val;
937 	    break;
938 
939 	case DT_VERNEED:
940 	    obj->verneed = (const Elf_Verneed *) (obj->relocbase +
941 		dynp->d_un.d_val);
942 	    break;
943 
944 	case DT_VERNEEDNUM:
945 	    obj->verneednum = dynp->d_un.d_val;
946 	    break;
947 
948 	case DT_VERDEF:
949 	    obj->verdef = (const Elf_Verdef *) (obj->relocbase +
950 		dynp->d_un.d_val);
951 	    break;
952 
953 	case DT_VERDEFNUM:
954 	    obj->verdefnum = dynp->d_un.d_val;
955 	    break;
956 
957 	case DT_VERSYM:
958 	    obj->versyms = (const Elf_Versym *)(obj->relocbase +
959 		dynp->d_un.d_val);
960 	    break;
961 
962 	case DT_HASH:
963 	    {
964 		hashtab = (const Elf_Hashelt *)(obj->relocbase +
965 		    dynp->d_un.d_ptr);
966 		obj->nbuckets = hashtab[0];
967 		obj->nchains = hashtab[1];
968 		obj->buckets = hashtab + 2;
969 		obj->chains = obj->buckets + obj->nbuckets;
970 		obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 &&
971 		  obj->buckets != NULL;
972 	    }
973 	    break;
974 
975 	case DT_GNU_HASH:
976 	    {
977 		hashtab = (const Elf_Hashelt *)(obj->relocbase +
978 		    dynp->d_un.d_ptr);
979 		obj->nbuckets_gnu = hashtab[0];
980 		obj->symndx_gnu = hashtab[1];
981 		nmaskwords = hashtab[2];
982 		bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords;
983 		/* Number of bitmask words is required to be power of 2 */
984 		nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0);
985 		obj->maskwords_bm_gnu = nmaskwords - 1;
986 		obj->shift2_gnu = hashtab[3];
987 		obj->bloom_gnu = (Elf_Addr *) (hashtab + 4);
988 		obj->buckets_gnu = hashtab + 4 + bloom_size32;
989 		obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu -
990 		  obj->symndx_gnu;
991 		obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 &&
992 		  obj->buckets_gnu != NULL;
993 	    }
994 	    break;
995 
996 	case DT_NEEDED:
997 	    if (!obj->rtld) {
998 		Needed_Entry *nep = NEW(Needed_Entry);
999 		nep->name = dynp->d_un.d_val;
1000 		nep->obj = NULL;
1001 		nep->next = NULL;
1002 
1003 		*needed_tail = nep;
1004 		needed_tail = &nep->next;
1005 	    }
1006 	    break;
1007 
1008 	case DT_FILTER:
1009 	    if (!obj->rtld) {
1010 		Needed_Entry *nep = NEW(Needed_Entry);
1011 		nep->name = dynp->d_un.d_val;
1012 		nep->obj = NULL;
1013 		nep->next = NULL;
1014 
1015 		*needed_filtees_tail = nep;
1016 		needed_filtees_tail = &nep->next;
1017 	    }
1018 	    break;
1019 
1020 	case DT_AUXILIARY:
1021 	    if (!obj->rtld) {
1022 		Needed_Entry *nep = NEW(Needed_Entry);
1023 		nep->name = dynp->d_un.d_val;
1024 		nep->obj = NULL;
1025 		nep->next = NULL;
1026 
1027 		*needed_aux_filtees_tail = nep;
1028 		needed_aux_filtees_tail = &nep->next;
1029 	    }
1030 	    break;
1031 
1032 	case DT_PLTGOT:
1033 	    obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
1034 	    break;
1035 
1036 	case DT_TEXTREL:
1037 	    obj->textrel = true;
1038 	    break;
1039 
1040 	case DT_SYMBOLIC:
1041 	    obj->symbolic = true;
1042 	    break;
1043 
1044 	case DT_RPATH:
1045 	    /*
1046 	     * We have to wait until later to process this, because we
1047 	     * might not have gotten the address of the string table yet.
1048 	     */
1049 	    *dyn_rpath = dynp;
1050 	    break;
1051 
1052 	case DT_SONAME:
1053 	    *dyn_soname = dynp;
1054 	    break;
1055 
1056 	case DT_RUNPATH:
1057 	    *dyn_runpath = dynp;
1058 	    break;
1059 
1060 	case DT_INIT:
1061 	    obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1062 	    break;
1063 
1064 	case DT_PREINIT_ARRAY:
1065 	    obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1066 	    break;
1067 
1068 	case DT_PREINIT_ARRAYSZ:
1069 	    obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1070 	    break;
1071 
1072 	case DT_INIT_ARRAY:
1073 	    obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1074 	    break;
1075 
1076 	case DT_INIT_ARRAYSZ:
1077 	    obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1078 	    break;
1079 
1080 	case DT_FINI:
1081 	    obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1082 	    break;
1083 
1084 	case DT_FINI_ARRAY:
1085 	    obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1086 	    break;
1087 
1088 	case DT_FINI_ARRAYSZ:
1089 	    obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1090 	    break;
1091 
1092 	/*
1093 	 * Don't process DT_DEBUG on MIPS as the dynamic section
1094 	 * is mapped read-only. DT_MIPS_RLD_MAP is used instead.
1095 	 */
1096 
1097 #ifndef __mips__
1098 	case DT_DEBUG:
1099 	    /* XXX - not implemented yet */
1100 	    if (!early)
1101 		dbg("Filling in DT_DEBUG entry");
1102 	    ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
1103 	    break;
1104 #endif
1105 
1106 	case DT_FLAGS:
1107 		if ((dynp->d_un.d_val & DF_ORIGIN) && trust)
1108 		    obj->z_origin = true;
1109 		if (dynp->d_un.d_val & DF_SYMBOLIC)
1110 		    obj->symbolic = true;
1111 		if (dynp->d_un.d_val & DF_TEXTREL)
1112 		    obj->textrel = true;
1113 		if (dynp->d_un.d_val & DF_BIND_NOW)
1114 		    obj->bind_now = true;
1115 		/*if (dynp->d_un.d_val & DF_STATIC_TLS)
1116 		    ;*/
1117 	    break;
1118 #ifdef __mips__
1119 	case DT_MIPS_LOCAL_GOTNO:
1120 		obj->local_gotno = dynp->d_un.d_val;
1121 	    break;
1122 
1123 	case DT_MIPS_SYMTABNO:
1124 		obj->symtabno = dynp->d_un.d_val;
1125 		break;
1126 
1127 	case DT_MIPS_GOTSYM:
1128 		obj->gotsym = dynp->d_un.d_val;
1129 		break;
1130 
1131 	case DT_MIPS_RLD_MAP:
1132 		*((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug;
1133 		break;
1134 #endif
1135 
1136 	case DT_FLAGS_1:
1137 		if (dynp->d_un.d_val & DF_1_NOOPEN)
1138 		    obj->z_noopen = true;
1139 		if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
1140 		    obj->z_origin = true;
1141 		/*if (dynp->d_un.d_val & DF_1_GLOBAL)
1142 		    XXX ;*/
1143 		if (dynp->d_un.d_val & DF_1_BIND_NOW)
1144 		    obj->bind_now = true;
1145 		if (dynp->d_un.d_val & DF_1_NODELETE)
1146 		    obj->z_nodelete = true;
1147 		if (dynp->d_un.d_val & DF_1_LOADFLTR)
1148 		    obj->z_loadfltr = true;
1149 		if (dynp->d_un.d_val & DF_1_INTERPOSE)
1150 		    obj->z_interpose = true;
1151 		if (dynp->d_un.d_val & DF_1_NODEFLIB)
1152 		    obj->z_nodeflib = true;
1153 	    break;
1154 
1155 	default:
1156 	    if (!early) {
1157 		dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
1158 		    (long)dynp->d_tag);
1159 	    }
1160 	    break;
1161 	}
1162     }
1163 
1164     obj->traced = false;
1165 
1166     if (plttype == DT_RELA) {
1167 	obj->pltrela = (const Elf_Rela *) obj->pltrel;
1168 	obj->pltrel = NULL;
1169 	obj->pltrelasize = obj->pltrelsize;
1170 	obj->pltrelsize = 0;
1171     }
1172 
1173     /* Determine size of dynsym table (equal to nchains of sysv hash) */
1174     if (obj->valid_hash_sysv)
1175 	obj->dynsymcount = obj->nchains;
1176     else if (obj->valid_hash_gnu) {
1177 	obj->dynsymcount = 0;
1178 	for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) {
1179 	    if (obj->buckets_gnu[bkt] == 0)
1180 		continue;
1181 	    hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]];
1182 	    do
1183 		obj->dynsymcount++;
1184 	    while ((*hashval++ & 1u) == 0);
1185 	}
1186 	obj->dynsymcount += obj->symndx_gnu;
1187     }
1188 }
1189 
1190 static void
1191 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
1192     const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath)
1193 {
1194 
1195     if (obj->z_origin && obj->origin_path == NULL) {
1196 	obj->origin_path = xmalloc(PATH_MAX);
1197 	if (rtld_dirname_abs(obj->path, obj->origin_path) == -1)
1198 	    die();
1199     }
1200 
1201     if (dyn_runpath != NULL) {
1202 	obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val;
1203 	if (obj->z_origin)
1204 	    obj->runpath = origin_subst(obj->runpath, obj->origin_path);
1205     }
1206     else if (dyn_rpath != NULL) {
1207 	obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
1208 	if (obj->z_origin)
1209 	    obj->rpath = origin_subst(obj->rpath, obj->origin_path);
1210     }
1211 
1212     if (dyn_soname != NULL)
1213 	object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
1214 }
1215 
1216 static void
1217 digest_dynamic(Obj_Entry *obj, int early)
1218 {
1219 	const Elf_Dyn *dyn_rpath;
1220 	const Elf_Dyn *dyn_soname;
1221 	const Elf_Dyn *dyn_runpath;
1222 
1223 	digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath);
1224 	digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath);
1225 }
1226 
1227 /*
1228  * Process a shared object's program header.  This is used only for the
1229  * main program, when the kernel has already loaded the main program
1230  * into memory before calling the dynamic linker.  It creates and
1231  * returns an Obj_Entry structure.
1232  */
1233 static Obj_Entry *
1234 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
1235 {
1236     Obj_Entry *obj;
1237     const Elf_Phdr *phlimit = phdr + phnum;
1238     const Elf_Phdr *ph;
1239     Elf_Addr note_start, note_end;
1240     int nsegs = 0;
1241 
1242     obj = obj_new();
1243     for (ph = phdr;  ph < phlimit;  ph++) {
1244 	if (ph->p_type != PT_PHDR)
1245 	    continue;
1246 
1247 	obj->phdr = phdr;
1248 	obj->phsize = ph->p_memsz;
1249 	obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
1250 	break;
1251     }
1252 
1253     obj->stack_flags = PF_X | PF_R | PF_W;
1254 
1255     for (ph = phdr;  ph < phlimit;  ph++) {
1256 	switch (ph->p_type) {
1257 
1258 	case PT_INTERP:
1259 	    obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
1260 	    break;
1261 
1262 	case PT_LOAD:
1263 	    if (nsegs == 0) {	/* First load segment */
1264 		obj->vaddrbase = trunc_page(ph->p_vaddr);
1265 		obj->mapbase = obj->vaddrbase + obj->relocbase;
1266 		obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
1267 		  obj->vaddrbase;
1268 	    } else {		/* Last load segment */
1269 		obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1270 		  obj->vaddrbase;
1271 	    }
1272 	    nsegs++;
1273 	    break;
1274 
1275 	case PT_DYNAMIC:
1276 	    obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
1277 	    break;
1278 
1279 	case PT_TLS:
1280 	    obj->tlsindex = 1;
1281 	    obj->tlssize = ph->p_memsz;
1282 	    obj->tlsalign = ph->p_align;
1283 	    obj->tlsinitsize = ph->p_filesz;
1284 	    obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
1285 	    break;
1286 
1287 	case PT_GNU_STACK:
1288 	    obj->stack_flags = ph->p_flags;
1289 	    break;
1290 
1291 	case PT_GNU_RELRO:
1292 	    obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
1293 	    obj->relro_size = round_page(ph->p_memsz);
1294 	    break;
1295 
1296 	case PT_NOTE:
1297 	    note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr;
1298 	    note_end = note_start + ph->p_filesz;
1299 	    digest_notes(obj, note_start, note_end);
1300 	    break;
1301 	}
1302     }
1303     if (nsegs < 1) {
1304 	_rtld_error("%s: too few PT_LOAD segments", path);
1305 	return NULL;
1306     }
1307 
1308     obj->entry = entry;
1309     return obj;
1310 }
1311 
1312 void
1313 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end)
1314 {
1315 	const Elf_Note *note;
1316 	const char *note_name;
1317 	uintptr_t p;
1318 
1319 	for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end;
1320 	    note = (const Elf_Note *)((const char *)(note + 1) +
1321 	      roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
1322 	      roundup2(note->n_descsz, sizeof(Elf32_Addr)))) {
1323 		if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) ||
1324 		    note->n_descsz != sizeof(int32_t))
1325 			continue;
1326 		if (note->n_type != ABI_NOTETYPE &&
1327 		    note->n_type != CRT_NOINIT_NOTETYPE)
1328 			continue;
1329 		note_name = (const char *)(note + 1);
1330 		if (strncmp(NOTE_FREEBSD_VENDOR, note_name,
1331 		    sizeof(NOTE_FREEBSD_VENDOR)) != 0)
1332 			continue;
1333 		switch (note->n_type) {
1334 		case ABI_NOTETYPE:
1335 			/* FreeBSD osrel note */
1336 			p = (uintptr_t)(note + 1);
1337 			p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1338 			obj->osrel = *(const int32_t *)(p);
1339 			dbg("note osrel %d", obj->osrel);
1340 			break;
1341 		case CRT_NOINIT_NOTETYPE:
1342 			/* FreeBSD 'crt does not call init' note */
1343 			obj->crt_no_init = true;
1344 			dbg("note crt_no_init");
1345 			break;
1346 		}
1347 	}
1348 }
1349 
1350 static Obj_Entry *
1351 dlcheck(void *handle)
1352 {
1353     Obj_Entry *obj;
1354 
1355     for (obj = obj_list;  obj != NULL;  obj = obj->next)
1356 	if (obj == (Obj_Entry *) handle)
1357 	    break;
1358 
1359     if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1360 	_rtld_error("Invalid shared object handle %p", handle);
1361 	return NULL;
1362     }
1363     return obj;
1364 }
1365 
1366 /*
1367  * If the given object is already in the donelist, return true.  Otherwise
1368  * add the object to the list and return false.
1369  */
1370 static bool
1371 donelist_check(DoneList *dlp, const Obj_Entry *obj)
1372 {
1373     unsigned int i;
1374 
1375     for (i = 0;  i < dlp->num_used;  i++)
1376 	if (dlp->objs[i] == obj)
1377 	    return true;
1378     /*
1379      * Our donelist allocation should always be sufficient.  But if
1380      * our threads locking isn't working properly, more shared objects
1381      * could have been loaded since we allocated the list.  That should
1382      * never happen, but we'll handle it properly just in case it does.
1383      */
1384     if (dlp->num_used < dlp->num_alloc)
1385 	dlp->objs[dlp->num_used++] = obj;
1386     return false;
1387 }
1388 
1389 /*
1390  * Hash function for symbol table lookup.  Don't even think about changing
1391  * this.  It is specified by the System V ABI.
1392  */
1393 unsigned long
1394 elf_hash(const char *name)
1395 {
1396     const unsigned char *p = (const unsigned char *) name;
1397     unsigned long h = 0;
1398     unsigned long g;
1399 
1400     while (*p != '\0') {
1401 	h = (h << 4) + *p++;
1402 	if ((g = h & 0xf0000000) != 0)
1403 	    h ^= g >> 24;
1404 	h &= ~g;
1405     }
1406     return h;
1407 }
1408 
1409 /*
1410  * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits
1411  * unsigned in case it's implemented with a wider type.
1412  */
1413 static uint32_t
1414 gnu_hash(const char *s)
1415 {
1416 	uint32_t h;
1417 	unsigned char c;
1418 
1419 	h = 5381;
1420 	for (c = *s; c != '\0'; c = *++s)
1421 		h = h * 33 + c;
1422 	return (h & 0xffffffff);
1423 }
1424 
1425 
1426 /*
1427  * Find the library with the given name, and return its full pathname.
1428  * The returned string is dynamically allocated.  Generates an error
1429  * message and returns NULL if the library cannot be found.
1430  *
1431  * If the second argument is non-NULL, then it refers to an already-
1432  * loaded shared object, whose library search path will be searched.
1433  *
1434  * If a library is successfully located via LD_LIBRARY_PATH_FDS, its
1435  * descriptor (which is close-on-exec) will be passed out via the third
1436  * argument.
1437  *
1438  * The search order is:
1439  *   DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1)
1440  *   DT_RPATH of the main object if DSO without defined DT_RUNPATH (1)
1441  *   LD_LIBRARY_PATH
1442  *   DT_RUNPATH in the referencing file
1443  *   ldconfig hints (if -z nodefaultlib, filter out default library directories
1444  *	 from list)
1445  *   /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib
1446  *
1447  * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined.
1448  */
1449 static char *
1450 find_library(const char *xname, const Obj_Entry *refobj, int *fdp)
1451 {
1452     char *pathname;
1453     char *name;
1454     bool nodeflib, objgiven;
1455 
1456     objgiven = refobj != NULL;
1457     if (strchr(xname, '/') != NULL) {	/* Hard coded pathname */
1458 	if (xname[0] != '/' && !trust) {
1459 	    _rtld_error("Absolute pathname required for shared object \"%s\"",
1460 	      xname);
1461 	    return NULL;
1462 	}
1463 	if (objgiven && refobj->z_origin) {
1464 		return (origin_subst(__DECONST(char *, xname),
1465 		    refobj->origin_path));
1466 	} else {
1467 		return (xstrdup(xname));
1468 	}
1469     }
1470 
1471     if (libmap_disable || !objgiven ||
1472 	(name = lm_find(refobj->path, xname)) == NULL)
1473 	name = (char *)xname;
1474 
1475     dbg(" Searching for \"%s\"", name);
1476 
1477     /*
1478      * If refobj->rpath != NULL, then refobj->runpath is NULL.  Fall
1479      * back to pre-conforming behaviour if user requested so with
1480      * LD_LIBRARY_PATH_RPATH environment variable and ignore -z
1481      * nodeflib.
1482      */
1483     if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) {
1484 	if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
1485 	  (refobj != NULL &&
1486 	  (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1487 	  (pathname = search_library_pathfds(name, ld_library_dirs, fdp)) != NULL ||
1488           (pathname = search_library_path(name, gethints(false))) != NULL ||
1489 	  (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
1490 	    return (pathname);
1491     } else {
1492 	nodeflib = objgiven ? refobj->z_nodeflib : false;
1493 	if ((objgiven &&
1494 	  (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1495 	  (objgiven && refobj->runpath == NULL && refobj != obj_main &&
1496 	  (pathname = search_library_path(name, obj_main->rpath)) != NULL) ||
1497 	  (pathname = search_library_path(name, ld_library_path)) != NULL ||
1498 	  (objgiven &&
1499 	  (pathname = search_library_path(name, refobj->runpath)) != NULL) ||
1500 	  (pathname = search_library_pathfds(name, ld_library_dirs, fdp)) != NULL ||
1501 	  (pathname = search_library_path(name, gethints(nodeflib))) != NULL ||
1502 	  (objgiven && !nodeflib &&
1503 	  (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL))
1504 	    return (pathname);
1505     }
1506 
1507     if (objgiven && refobj->path != NULL) {
1508 	_rtld_error("Shared object \"%s\" not found, required by \"%s\"",
1509 	  name, basename(refobj->path));
1510     } else {
1511 	_rtld_error("Shared object \"%s\" not found", name);
1512     }
1513     return NULL;
1514 }
1515 
1516 /*
1517  * Given a symbol number in a referencing object, find the corresponding
1518  * definition of the symbol.  Returns a pointer to the symbol, or NULL if
1519  * no definition was found.  Returns a pointer to the Obj_Entry of the
1520  * defining object via the reference parameter DEFOBJ_OUT.
1521  */
1522 const Elf_Sym *
1523 find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1524     const Obj_Entry **defobj_out, int flags, SymCache *cache,
1525     RtldLockState *lockstate)
1526 {
1527     const Elf_Sym *ref;
1528     const Elf_Sym *def;
1529     const Obj_Entry *defobj;
1530     SymLook req;
1531     const char *name;
1532     int res;
1533 
1534     /*
1535      * If we have already found this symbol, get the information from
1536      * the cache.
1537      */
1538     if (symnum >= refobj->dynsymcount)
1539 	return NULL;	/* Bad object */
1540     if (cache != NULL && cache[symnum].sym != NULL) {
1541 	*defobj_out = cache[symnum].obj;
1542 	return cache[symnum].sym;
1543     }
1544 
1545     ref = refobj->symtab + symnum;
1546     name = refobj->strtab + ref->st_name;
1547     def = NULL;
1548     defobj = NULL;
1549 
1550     /*
1551      * We don't have to do a full scale lookup if the symbol is local.
1552      * We know it will bind to the instance in this load module; to
1553      * which we already have a pointer (ie ref). By not doing a lookup,
1554      * we not only improve performance, but it also avoids unresolvable
1555      * symbols when local symbols are not in the hash table. This has
1556      * been seen with the ia64 toolchain.
1557      */
1558     if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1559 	if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
1560 	    _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1561 		symnum);
1562 	}
1563 	symlook_init(&req, name);
1564 	req.flags = flags;
1565 	req.ventry = fetch_ventry(refobj, symnum);
1566 	req.lockstate = lockstate;
1567 	res = symlook_default(&req, refobj);
1568 	if (res == 0) {
1569 	    def = req.sym_out;
1570 	    defobj = req.defobj_out;
1571 	}
1572     } else {
1573 	def = ref;
1574 	defobj = refobj;
1575     }
1576 
1577     /*
1578      * If we found no definition and the reference is weak, treat the
1579      * symbol as having the value zero.
1580      */
1581     if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1582 	def = &sym_zero;
1583 	defobj = obj_main;
1584     }
1585 
1586     if (def != NULL) {
1587 	*defobj_out = defobj;
1588 	/* Record the information in the cache to avoid subsequent lookups. */
1589 	if (cache != NULL) {
1590 	    cache[symnum].sym = def;
1591 	    cache[symnum].obj = defobj;
1592 	}
1593     } else {
1594 	if (refobj != &obj_rtld)
1595 	    _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1596     }
1597     return def;
1598 }
1599 
1600 /*
1601  * Return the search path from the ldconfig hints file, reading it if
1602  * necessary.  If nostdlib is true, then the default search paths are
1603  * not added to result.
1604  *
1605  * Returns NULL if there are problems with the hints file,
1606  * or if the search path there is empty.
1607  */
1608 static const char *
1609 gethints(bool nostdlib)
1610 {
1611 	static char *hints, *filtered_path;
1612 	struct elfhints_hdr hdr;
1613 	struct fill_search_info_args sargs, hargs;
1614 	struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo;
1615 	struct dl_serpath *SLPpath, *hintpath;
1616 	char *p;
1617 	unsigned int SLPndx, hintndx, fndx, fcount;
1618 	int fd;
1619 	size_t flen;
1620 	bool skip;
1621 
1622 	/* First call, read the hints file */
1623 	if (hints == NULL) {
1624 		/* Keep from trying again in case the hints file is bad. */
1625 		hints = "";
1626 
1627 		if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1)
1628 			return (NULL);
1629 		if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1630 		    hdr.magic != ELFHINTS_MAGIC ||
1631 		    hdr.version != 1) {
1632 			close(fd);
1633 			return (NULL);
1634 		}
1635 		p = xmalloc(hdr.dirlistlen + 1);
1636 		if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1637 		    read(fd, p, hdr.dirlistlen + 1) !=
1638 		    (ssize_t)hdr.dirlistlen + 1) {
1639 			free(p);
1640 			close(fd);
1641 			return (NULL);
1642 		}
1643 		hints = p;
1644 		close(fd);
1645 	}
1646 
1647 	/*
1648 	 * If caller agreed to receive list which includes the default
1649 	 * paths, we are done. Otherwise, if we still did not
1650 	 * calculated filtered result, do it now.
1651 	 */
1652 	if (!nostdlib)
1653 		return (hints[0] != '\0' ? hints : NULL);
1654 	if (filtered_path != NULL)
1655 		goto filt_ret;
1656 
1657 	/*
1658 	 * Obtain the list of all configured search paths, and the
1659 	 * list of the default paths.
1660 	 *
1661 	 * First estimate the size of the results.
1662 	 */
1663 	smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
1664 	smeta.dls_cnt = 0;
1665 	hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
1666 	hmeta.dls_cnt = 0;
1667 
1668 	sargs.request = RTLD_DI_SERINFOSIZE;
1669 	sargs.serinfo = &smeta;
1670 	hargs.request = RTLD_DI_SERINFOSIZE;
1671 	hargs.serinfo = &hmeta;
1672 
1673 	path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs);
1674 	path_enumerate(p, fill_search_info, &hargs);
1675 
1676 	SLPinfo = xmalloc(smeta.dls_size);
1677 	hintinfo = xmalloc(hmeta.dls_size);
1678 
1679 	/*
1680 	 * Next fetch both sets of paths.
1681 	 */
1682 	sargs.request = RTLD_DI_SERINFO;
1683 	sargs.serinfo = SLPinfo;
1684 	sargs.serpath = &SLPinfo->dls_serpath[0];
1685 	sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt];
1686 
1687 	hargs.request = RTLD_DI_SERINFO;
1688 	hargs.serinfo = hintinfo;
1689 	hargs.serpath = &hintinfo->dls_serpath[0];
1690 	hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt];
1691 
1692 	path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs);
1693 	path_enumerate(p, fill_search_info, &hargs);
1694 
1695 	/*
1696 	 * Now calculate the difference between two sets, by excluding
1697 	 * standard paths from the full set.
1698 	 */
1699 	fndx = 0;
1700 	fcount = 0;
1701 	filtered_path = xmalloc(hdr.dirlistlen + 1);
1702 	hintpath = &hintinfo->dls_serpath[0];
1703 	for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) {
1704 		skip = false;
1705 		SLPpath = &SLPinfo->dls_serpath[0];
1706 		/*
1707 		 * Check each standard path against current.
1708 		 */
1709 		for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) {
1710 			/* matched, skip the path */
1711 			if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) {
1712 				skip = true;
1713 				break;
1714 			}
1715 		}
1716 		if (skip)
1717 			continue;
1718 		/*
1719 		 * Not matched against any standard path, add the path
1720 		 * to result. Separate consequtive paths with ':'.
1721 		 */
1722 		if (fcount > 0) {
1723 			filtered_path[fndx] = ':';
1724 			fndx++;
1725 		}
1726 		fcount++;
1727 		flen = strlen(hintpath->dls_name);
1728 		strncpy((filtered_path + fndx),	hintpath->dls_name, flen);
1729 		fndx += flen;
1730 	}
1731 	filtered_path[fndx] = '\0';
1732 
1733 	free(SLPinfo);
1734 	free(hintinfo);
1735 
1736 filt_ret:
1737 	return (filtered_path[0] != '\0' ? filtered_path : NULL);
1738 }
1739 
1740 static void
1741 init_dag(Obj_Entry *root)
1742 {
1743     const Needed_Entry *needed;
1744     const Objlist_Entry *elm;
1745     DoneList donelist;
1746 
1747     if (root->dag_inited)
1748 	return;
1749     donelist_init(&donelist);
1750 
1751     /* Root object belongs to own DAG. */
1752     objlist_push_tail(&root->dldags, root);
1753     objlist_push_tail(&root->dagmembers, root);
1754     donelist_check(&donelist, root);
1755 
1756     /*
1757      * Add dependencies of root object to DAG in breadth order
1758      * by exploiting the fact that each new object get added
1759      * to the tail of the dagmembers list.
1760      */
1761     STAILQ_FOREACH(elm, &root->dagmembers, link) {
1762 	for (needed = elm->obj->needed; needed != NULL; needed = needed->next) {
1763 	    if (needed->obj == NULL || donelist_check(&donelist, needed->obj))
1764 		continue;
1765 	    objlist_push_tail(&needed->obj->dldags, root);
1766 	    objlist_push_tail(&root->dagmembers, needed->obj);
1767 	}
1768     }
1769     root->dag_inited = true;
1770 }
1771 
1772 static void
1773 process_nodelete(Obj_Entry *root)
1774 {
1775 	const Objlist_Entry *elm;
1776 
1777 	/*
1778 	 * Walk over object DAG and process every dependent object that
1779 	 * is marked as DF_1_NODELETE. They need to grow their own DAG,
1780 	 * which then should have its reference upped separately.
1781 	 */
1782 	STAILQ_FOREACH(elm, &root->dagmembers, link) {
1783 		if (elm->obj != NULL && elm->obj->z_nodelete &&
1784 		    !elm->obj->ref_nodel) {
1785 			dbg("obj %s nodelete", elm->obj->path);
1786 			init_dag(elm->obj);
1787 			ref_dag(elm->obj);
1788 			elm->obj->ref_nodel = true;
1789 		}
1790 	}
1791 }
1792 /*
1793  * Initialize the dynamic linker.  The argument is the address at which
1794  * the dynamic linker has been mapped into memory.  The primary task of
1795  * this function is to relocate the dynamic linker.
1796  */
1797 static void
1798 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
1799 {
1800     Obj_Entry objtmp;	/* Temporary rtld object */
1801     const Elf_Dyn *dyn_rpath;
1802     const Elf_Dyn *dyn_soname;
1803     const Elf_Dyn *dyn_runpath;
1804 
1805 #ifdef RTLD_INIT_PAGESIZES_EARLY
1806     /* The page size is required by the dynamic memory allocator. */
1807     init_pagesizes(aux_info);
1808 #endif
1809 
1810     /*
1811      * Conjure up an Obj_Entry structure for the dynamic linker.
1812      *
1813      * The "path" member can't be initialized yet because string constants
1814      * cannot yet be accessed. Below we will set it correctly.
1815      */
1816     memset(&objtmp, 0, sizeof(objtmp));
1817     objtmp.path = NULL;
1818     objtmp.rtld = true;
1819     objtmp.mapbase = mapbase;
1820 #ifdef PIC
1821     objtmp.relocbase = mapbase;
1822 #endif
1823     if (RTLD_IS_DYNAMIC()) {
1824 	objtmp.dynamic = rtld_dynamic(&objtmp);
1825 	digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath);
1826 	assert(objtmp.needed == NULL);
1827 #if !defined(__mips__)
1828 	/* MIPS has a bogus DT_TEXTREL. */
1829 	assert(!objtmp.textrel);
1830 #endif
1831 
1832 	/*
1833 	 * Temporarily put the dynamic linker entry into the object list, so
1834 	 * that symbols can be found.
1835 	 */
1836 
1837 	relocate_objects(&objtmp, true, &objtmp, 0, NULL);
1838     }
1839 
1840     /* Initialize the object list. */
1841     obj_tail = &obj_list;
1842 
1843     /* Now that non-local variables can be accesses, copy out obj_rtld. */
1844     memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
1845 
1846 #ifndef RTLD_INIT_PAGESIZES_EARLY
1847     /* The page size is required by the dynamic memory allocator. */
1848     init_pagesizes(aux_info);
1849 #endif
1850 
1851     if (aux_info[AT_OSRELDATE] != NULL)
1852 	    osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
1853 
1854     digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath);
1855 
1856     /* Replace the path with a dynamically allocated copy. */
1857     obj_rtld.path = xstrdup(PATH_RTLD);
1858 
1859     r_debug.r_brk = r_debug_state;
1860     r_debug.r_state = RT_CONSISTENT;
1861 }
1862 
1863 /*
1864  * Retrieve the array of supported page sizes.  The kernel provides the page
1865  * sizes in increasing order.
1866  */
1867 static void
1868 init_pagesizes(Elf_Auxinfo **aux_info)
1869 {
1870 	static size_t psa[MAXPAGESIZES];
1871 	int mib[2];
1872 	size_t len, size;
1873 
1874 	if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] !=
1875 	    NULL) {
1876 		size = aux_info[AT_PAGESIZESLEN]->a_un.a_val;
1877 		pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr;
1878 	} else {
1879 		len = 2;
1880 		if (sysctlnametomib("hw.pagesizes", mib, &len) == 0)
1881 			size = sizeof(psa);
1882 		else {
1883 			/* As a fallback, retrieve the base page size. */
1884 			size = sizeof(psa[0]);
1885 			if (aux_info[AT_PAGESZ] != NULL) {
1886 				psa[0] = aux_info[AT_PAGESZ]->a_un.a_val;
1887 				goto psa_filled;
1888 			} else {
1889 				mib[0] = CTL_HW;
1890 				mib[1] = HW_PAGESIZE;
1891 				len = 2;
1892 			}
1893 		}
1894 		if (sysctl(mib, len, psa, &size, NULL, 0) == -1) {
1895 			_rtld_error("sysctl for hw.pagesize(s) failed");
1896 			die();
1897 		}
1898 psa_filled:
1899 		pagesizes = psa;
1900 	}
1901 	npagesizes = size / sizeof(pagesizes[0]);
1902 	/* Discard any invalid entries at the end of the array. */
1903 	while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0)
1904 		npagesizes--;
1905 }
1906 
1907 /*
1908  * Add the init functions from a needed object list (and its recursive
1909  * needed objects) to "list".  This is not used directly; it is a helper
1910  * function for initlist_add_objects().  The write lock must be held
1911  * when this function is called.
1912  */
1913 static void
1914 initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1915 {
1916     /* Recursively process the successor needed objects. */
1917     if (needed->next != NULL)
1918 	initlist_add_neededs(needed->next, list);
1919 
1920     /* Process the current needed object. */
1921     if (needed->obj != NULL)
1922 	initlist_add_objects(needed->obj, &needed->obj->next, list);
1923 }
1924 
1925 /*
1926  * Scan all of the DAGs rooted in the range of objects from "obj" to
1927  * "tail" and add their init functions to "list".  This recurses over
1928  * the DAGs and ensure the proper init ordering such that each object's
1929  * needed libraries are initialized before the object itself.  At the
1930  * same time, this function adds the objects to the global finalization
1931  * list "list_fini" in the opposite order.  The write lock must be
1932  * held when this function is called.
1933  */
1934 static void
1935 initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1936 {
1937 
1938     if (obj->init_scanned || obj->init_done)
1939 	return;
1940     obj->init_scanned = true;
1941 
1942     /* Recursively process the successor objects. */
1943     if (&obj->next != tail)
1944 	initlist_add_objects(obj->next, tail, list);
1945 
1946     /* Recursively process the needed objects. */
1947     if (obj->needed != NULL)
1948 	initlist_add_neededs(obj->needed, list);
1949     if (obj->needed_filtees != NULL)
1950 	initlist_add_neededs(obj->needed_filtees, list);
1951     if (obj->needed_aux_filtees != NULL)
1952 	initlist_add_neededs(obj->needed_aux_filtees, list);
1953 
1954     /* Add the object to the init list. */
1955     if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL ||
1956       obj->init_array != (Elf_Addr)NULL)
1957 	objlist_push_tail(list, obj);
1958 
1959     /* Add the object to the global fini list in the reverse order. */
1960     if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL)
1961       && !obj->on_fini_list) {
1962 	objlist_push_head(&list_fini, obj);
1963 	obj->on_fini_list = true;
1964     }
1965 }
1966 
1967 #ifndef FPTR_TARGET
1968 #define FPTR_TARGET(f)	((Elf_Addr) (f))
1969 #endif
1970 
1971 static void
1972 free_needed_filtees(Needed_Entry *n)
1973 {
1974     Needed_Entry *needed, *needed1;
1975 
1976     for (needed = n; needed != NULL; needed = needed->next) {
1977 	if (needed->obj != NULL) {
1978 	    dlclose(needed->obj);
1979 	    needed->obj = NULL;
1980 	}
1981     }
1982     for (needed = n; needed != NULL; needed = needed1) {
1983 	needed1 = needed->next;
1984 	free(needed);
1985     }
1986 }
1987 
1988 static void
1989 unload_filtees(Obj_Entry *obj)
1990 {
1991 
1992     free_needed_filtees(obj->needed_filtees);
1993     obj->needed_filtees = NULL;
1994     free_needed_filtees(obj->needed_aux_filtees);
1995     obj->needed_aux_filtees = NULL;
1996     obj->filtees_loaded = false;
1997 }
1998 
1999 static void
2000 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags,
2001     RtldLockState *lockstate)
2002 {
2003 
2004     for (; needed != NULL; needed = needed->next) {
2005 	needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj,
2006 	  flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) |
2007 	  RTLD_LOCAL, lockstate);
2008     }
2009 }
2010 
2011 static void
2012 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate)
2013 {
2014 
2015     lock_restart_for_upgrade(lockstate);
2016     if (!obj->filtees_loaded) {
2017 	load_filtee1(obj, obj->needed_filtees, flags, lockstate);
2018 	load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate);
2019 	obj->filtees_loaded = true;
2020     }
2021 }
2022 
2023 static int
2024 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags)
2025 {
2026     Obj_Entry *obj1;
2027 
2028     for (; needed != NULL; needed = needed->next) {
2029 	obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj,
2030 	  flags & ~RTLD_LO_NOLOAD);
2031 	if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0)
2032 	    return (-1);
2033     }
2034     return (0);
2035 }
2036 
2037 /*
2038  * Given a shared object, traverse its list of needed objects, and load
2039  * each of them.  Returns 0 on success.  Generates an error message and
2040  * returns -1 on failure.
2041  */
2042 static int
2043 load_needed_objects(Obj_Entry *first, int flags)
2044 {
2045     Obj_Entry *obj;
2046 
2047     for (obj = first;  obj != NULL;  obj = obj->next) {
2048 	if (process_needed(obj, obj->needed, flags) == -1)
2049 	    return (-1);
2050     }
2051     return (0);
2052 }
2053 
2054 static int
2055 load_preload_objects(void)
2056 {
2057     char *p = ld_preload;
2058     Obj_Entry *obj;
2059     static const char delim[] = " \t:;";
2060 
2061     if (p == NULL)
2062 	return 0;
2063 
2064     p += strspn(p, delim);
2065     while (*p != '\0') {
2066 	size_t len = strcspn(p, delim);
2067 	char savech;
2068 
2069 	savech = p[len];
2070 	p[len] = '\0';
2071 	obj = load_object(p, -1, NULL, 0);
2072 	if (obj == NULL)
2073 	    return -1;	/* XXX - cleanup */
2074 	obj->z_interpose = true;
2075 	p[len] = savech;
2076 	p += len;
2077 	p += strspn(p, delim);
2078     }
2079     LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
2080     return 0;
2081 }
2082 
2083 static const char *
2084 printable_path(const char *path)
2085 {
2086 
2087 	return (path == NULL ? "<unknown>" : path);
2088 }
2089 
2090 /*
2091  * Load a shared object into memory, if it is not already loaded.  The
2092  * object may be specified by name or by user-supplied file descriptor
2093  * fd_u. In the later case, the fd_u descriptor is not closed, but its
2094  * duplicate is.
2095  *
2096  * Returns a pointer to the Obj_Entry for the object.  Returns NULL
2097  * on failure.
2098  */
2099 static Obj_Entry *
2100 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags)
2101 {
2102     Obj_Entry *obj;
2103     int fd;
2104     struct stat sb;
2105     char *path;
2106 
2107     fd = -1;
2108     if (name != NULL) {
2109 	for (obj = obj_list->next;  obj != NULL;  obj = obj->next) {
2110 	    if (object_match_name(obj, name))
2111 		return (obj);
2112 	}
2113 
2114 	path = find_library(name, refobj, &fd);
2115 	if (path == NULL)
2116 	    return (NULL);
2117     } else
2118 	path = NULL;
2119 
2120     if (fd >= 0) {
2121 	/*
2122 	 * search_library_pathfds() opens a fresh file descriptor for the
2123 	 * library, so there is no need to dup().
2124 	 */
2125     } else if (fd_u == -1) {
2126 	/*
2127 	 * If we didn't find a match by pathname, or the name is not
2128 	 * supplied, open the file and check again by device and inode.
2129 	 * This avoids false mismatches caused by multiple links or ".."
2130 	 * in pathnames.
2131 	 *
2132 	 * To avoid a race, we open the file and use fstat() rather than
2133 	 * using stat().
2134 	 */
2135 	if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) {
2136 	    _rtld_error("Cannot open \"%s\"", path);
2137 	    free(path);
2138 	    return (NULL);
2139 	}
2140     } else {
2141 	fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0);
2142 	if (fd == -1) {
2143 	    _rtld_error("Cannot dup fd");
2144 	    free(path);
2145 	    return (NULL);
2146 	}
2147     }
2148     if (fstat(fd, &sb) == -1) {
2149 	_rtld_error("Cannot fstat \"%s\"", printable_path(path));
2150 	close(fd);
2151 	free(path);
2152 	return NULL;
2153     }
2154     for (obj = obj_list->next;  obj != NULL;  obj = obj->next)
2155 	if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
2156 	    break;
2157     if (obj != NULL && name != NULL) {
2158 	object_add_name(obj, name);
2159 	free(path);
2160 	close(fd);
2161 	return obj;
2162     }
2163     if (flags & RTLD_LO_NOLOAD) {
2164 	free(path);
2165 	close(fd);
2166 	return (NULL);
2167     }
2168 
2169     /* First use of this object, so we must map it in */
2170     obj = do_load_object(fd, name, path, &sb, flags);
2171     if (obj == NULL)
2172 	free(path);
2173     close(fd);
2174 
2175     return obj;
2176 }
2177 
2178 static Obj_Entry *
2179 do_load_object(int fd, const char *name, char *path, struct stat *sbp,
2180   int flags)
2181 {
2182     Obj_Entry *obj;
2183     struct statfs fs;
2184 
2185     /*
2186      * but first, make sure that environment variables haven't been
2187      * used to circumvent the noexec flag on a filesystem.
2188      */
2189     if (dangerous_ld_env) {
2190 	if (fstatfs(fd, &fs) != 0) {
2191 	    _rtld_error("Cannot fstatfs \"%s\"", printable_path(path));
2192 	    return NULL;
2193 	}
2194 	if (fs.f_flags & MNT_NOEXEC) {
2195 	    _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
2196 	    return NULL;
2197 	}
2198     }
2199     dbg("loading \"%s\"", printable_path(path));
2200     obj = map_object(fd, printable_path(path), sbp);
2201     if (obj == NULL)
2202         return NULL;
2203 
2204     /*
2205      * If DT_SONAME is present in the object, digest_dynamic2 already
2206      * added it to the object names.
2207      */
2208     if (name != NULL)
2209 	object_add_name(obj, name);
2210     obj->path = path;
2211     digest_dynamic(obj, 0);
2212     dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path,
2213 	obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount);
2214     if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
2215       RTLD_LO_DLOPEN) {
2216 	dbg("refusing to load non-loadable \"%s\"", obj->path);
2217 	_rtld_error("Cannot dlopen non-loadable %s", obj->path);
2218 	munmap(obj->mapbase, obj->mapsize);
2219 	obj_free(obj);
2220 	return (NULL);
2221     }
2222 
2223     *obj_tail = obj;
2224     obj_tail = &obj->next;
2225     obj_count++;
2226     obj_loads++;
2227     linkmap_add(obj);	/* for GDB & dlinfo() */
2228     max_stack_flags |= obj->stack_flags;
2229 
2230     dbg("  %p .. %p: %s", obj->mapbase,
2231          obj->mapbase + obj->mapsize - 1, obj->path);
2232     if (obj->textrel)
2233 	dbg("  WARNING: %s has impure text", obj->path);
2234     LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
2235 	obj->path);
2236 
2237     return obj;
2238 }
2239 
2240 static Obj_Entry *
2241 obj_from_addr(const void *addr)
2242 {
2243     Obj_Entry *obj;
2244 
2245     for (obj = obj_list;  obj != NULL;  obj = obj->next) {
2246 	if (addr < (void *) obj->mapbase)
2247 	    continue;
2248 	if (addr < (void *) (obj->mapbase + obj->mapsize))
2249 	    return obj;
2250     }
2251     return NULL;
2252 }
2253 
2254 static void
2255 preinit_main(void)
2256 {
2257     Elf_Addr *preinit_addr;
2258     int index;
2259 
2260     preinit_addr = (Elf_Addr *)obj_main->preinit_array;
2261     if (preinit_addr == NULL)
2262 	return;
2263 
2264     for (index = 0; index < obj_main->preinit_array_num; index++) {
2265 	if (preinit_addr[index] != 0 && preinit_addr[index] != 1) {
2266 	    dbg("calling preinit function for %s at %p", obj_main->path,
2267 	      (void *)preinit_addr[index]);
2268 	    LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index],
2269 	      0, 0, obj_main->path);
2270 	    call_init_pointer(obj_main, preinit_addr[index]);
2271 	}
2272     }
2273 }
2274 
2275 /*
2276  * Call the finalization functions for each of the objects in "list"
2277  * belonging to the DAG of "root" and referenced once. If NULL "root"
2278  * is specified, every finalization function will be called regardless
2279  * of the reference count and the list elements won't be freed. All of
2280  * the objects are expected to have non-NULL fini functions.
2281  */
2282 static void
2283 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
2284 {
2285     Objlist_Entry *elm;
2286     char *saved_msg;
2287     Elf_Addr *fini_addr;
2288     int index;
2289 
2290     assert(root == NULL || root->refcount == 1);
2291 
2292     /*
2293      * Preserve the current error message since a fini function might
2294      * call into the dynamic linker and overwrite it.
2295      */
2296     saved_msg = errmsg_save();
2297     do {
2298 	STAILQ_FOREACH(elm, list, link) {
2299 	    if (root != NULL && (elm->obj->refcount != 1 ||
2300 	      objlist_find(&root->dagmembers, elm->obj) == NULL))
2301 		continue;
2302 	    /* Remove object from fini list to prevent recursive invocation. */
2303 	    STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2304 	    /*
2305 	     * XXX: If a dlopen() call references an object while the
2306 	     * fini function is in progress, we might end up trying to
2307 	     * unload the referenced object in dlclose() or the object
2308 	     * won't be unloaded although its fini function has been
2309 	     * called.
2310 	     */
2311 	    lock_release(rtld_bind_lock, lockstate);
2312 
2313 	    /*
2314 	     * It is legal to have both DT_FINI and DT_FINI_ARRAY defined.
2315 	     * When this happens, DT_FINI_ARRAY is processed first.
2316 	     */
2317 	    fini_addr = (Elf_Addr *)elm->obj->fini_array;
2318 	    if (fini_addr != NULL && elm->obj->fini_array_num > 0) {
2319 		for (index = elm->obj->fini_array_num - 1; index >= 0;
2320 		  index--) {
2321 		    if (fini_addr[index] != 0 && fini_addr[index] != 1) {
2322 			dbg("calling fini function for %s at %p",
2323 			    elm->obj->path, (void *)fini_addr[index]);
2324 			LD_UTRACE(UTRACE_FINI_CALL, elm->obj,
2325 			    (void *)fini_addr[index], 0, 0, elm->obj->path);
2326 			call_initfini_pointer(elm->obj, fini_addr[index]);
2327 		    }
2328 		}
2329 	    }
2330 	    if (elm->obj->fini != (Elf_Addr)NULL) {
2331 		dbg("calling fini function for %s at %p", elm->obj->path,
2332 		    (void *)elm->obj->fini);
2333 		LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini,
2334 		    0, 0, elm->obj->path);
2335 		call_initfini_pointer(elm->obj, elm->obj->fini);
2336 	    }
2337 	    wlock_acquire(rtld_bind_lock, lockstate);
2338 	    /* No need to free anything if process is going down. */
2339 	    if (root != NULL)
2340 	    	free(elm);
2341 	    /*
2342 	     * We must restart the list traversal after every fini call
2343 	     * because a dlclose() call from the fini function or from
2344 	     * another thread might have modified the reference counts.
2345 	     */
2346 	    break;
2347 	}
2348     } while (elm != NULL);
2349     errmsg_restore(saved_msg);
2350 }
2351 
2352 /*
2353  * Call the initialization functions for each of the objects in
2354  * "list".  All of the objects are expected to have non-NULL init
2355  * functions.
2356  */
2357 static void
2358 objlist_call_init(Objlist *list, RtldLockState *lockstate)
2359 {
2360     Objlist_Entry *elm;
2361     Obj_Entry *obj;
2362     char *saved_msg;
2363     Elf_Addr *init_addr;
2364     int index;
2365 
2366     /*
2367      * Clean init_scanned flag so that objects can be rechecked and
2368      * possibly initialized earlier if any of vectors called below
2369      * cause the change by using dlopen.
2370      */
2371     for (obj = obj_list;  obj != NULL;  obj = obj->next)
2372 	obj->init_scanned = false;
2373 
2374     /*
2375      * Preserve the current error message since an init function might
2376      * call into the dynamic linker and overwrite it.
2377      */
2378     saved_msg = errmsg_save();
2379     STAILQ_FOREACH(elm, list, link) {
2380 	if (elm->obj->init_done) /* Initialized early. */
2381 	    continue;
2382 	/*
2383 	 * Race: other thread might try to use this object before current
2384 	 * one completes the initilization. Not much can be done here
2385 	 * without better locking.
2386 	 */
2387 	elm->obj->init_done = true;
2388 	lock_release(rtld_bind_lock, lockstate);
2389 
2390         /*
2391          * It is legal to have both DT_INIT and DT_INIT_ARRAY defined.
2392          * When this happens, DT_INIT is processed first.
2393          */
2394 	if (elm->obj->init != (Elf_Addr)NULL) {
2395 	    dbg("calling init function for %s at %p", elm->obj->path,
2396 	        (void *)elm->obj->init);
2397 	    LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init,
2398 	        0, 0, elm->obj->path);
2399 	    call_initfini_pointer(elm->obj, elm->obj->init);
2400 	}
2401 	init_addr = (Elf_Addr *)elm->obj->init_array;
2402 	if (init_addr != NULL) {
2403 	    for (index = 0; index < elm->obj->init_array_num; index++) {
2404 		if (init_addr[index] != 0 && init_addr[index] != 1) {
2405 		    dbg("calling init function for %s at %p", elm->obj->path,
2406 			(void *)init_addr[index]);
2407 		    LD_UTRACE(UTRACE_INIT_CALL, elm->obj,
2408 			(void *)init_addr[index], 0, 0, elm->obj->path);
2409 		    call_init_pointer(elm->obj, init_addr[index]);
2410 		}
2411 	    }
2412 	}
2413 	wlock_acquire(rtld_bind_lock, lockstate);
2414     }
2415     errmsg_restore(saved_msg);
2416 }
2417 
2418 static void
2419 objlist_clear(Objlist *list)
2420 {
2421     Objlist_Entry *elm;
2422 
2423     while (!STAILQ_EMPTY(list)) {
2424 	elm = STAILQ_FIRST(list);
2425 	STAILQ_REMOVE_HEAD(list, link);
2426 	free(elm);
2427     }
2428 }
2429 
2430 static Objlist_Entry *
2431 objlist_find(Objlist *list, const Obj_Entry *obj)
2432 {
2433     Objlist_Entry *elm;
2434 
2435     STAILQ_FOREACH(elm, list, link)
2436 	if (elm->obj == obj)
2437 	    return elm;
2438     return NULL;
2439 }
2440 
2441 static void
2442 objlist_init(Objlist *list)
2443 {
2444     STAILQ_INIT(list);
2445 }
2446 
2447 static void
2448 objlist_push_head(Objlist *list, Obj_Entry *obj)
2449 {
2450     Objlist_Entry *elm;
2451 
2452     elm = NEW(Objlist_Entry);
2453     elm->obj = obj;
2454     STAILQ_INSERT_HEAD(list, elm, link);
2455 }
2456 
2457 static void
2458 objlist_push_tail(Objlist *list, Obj_Entry *obj)
2459 {
2460     Objlist_Entry *elm;
2461 
2462     elm = NEW(Objlist_Entry);
2463     elm->obj = obj;
2464     STAILQ_INSERT_TAIL(list, elm, link);
2465 }
2466 
2467 static void
2468 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj)
2469 {
2470 	Objlist_Entry *elm, *listelm;
2471 
2472 	STAILQ_FOREACH(listelm, list, link) {
2473 		if (listelm->obj == listobj)
2474 			break;
2475 	}
2476 	elm = NEW(Objlist_Entry);
2477 	elm->obj = obj;
2478 	if (listelm != NULL)
2479 		STAILQ_INSERT_AFTER(list, listelm, elm, link);
2480 	else
2481 		STAILQ_INSERT_TAIL(list, elm, link);
2482 }
2483 
2484 static void
2485 objlist_remove(Objlist *list, Obj_Entry *obj)
2486 {
2487     Objlist_Entry *elm;
2488 
2489     if ((elm = objlist_find(list, obj)) != NULL) {
2490 	STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2491 	free(elm);
2492     }
2493 }
2494 
2495 /*
2496  * Relocate dag rooted in the specified object.
2497  * Returns 0 on success, or -1 on failure.
2498  */
2499 
2500 static int
2501 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj,
2502     int flags, RtldLockState *lockstate)
2503 {
2504 	Objlist_Entry *elm;
2505 	int error;
2506 
2507 	error = 0;
2508 	STAILQ_FOREACH(elm, &root->dagmembers, link) {
2509 		error = relocate_object(elm->obj, bind_now, rtldobj, flags,
2510 		    lockstate);
2511 		if (error == -1)
2512 			break;
2513 	}
2514 	return (error);
2515 }
2516 
2517 /*
2518  * Relocate single object.
2519  * Returns 0 on success, or -1 on failure.
2520  */
2521 static int
2522 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
2523     int flags, RtldLockState *lockstate)
2524 {
2525 
2526 	if (obj->relocated)
2527 		return (0);
2528 	obj->relocated = true;
2529 	if (obj != rtldobj)
2530 		dbg("relocating \"%s\"", obj->path);
2531 
2532 	if (obj->symtab == NULL || obj->strtab == NULL ||
2533 	    !(obj->valid_hash_sysv || obj->valid_hash_gnu)) {
2534 		_rtld_error("%s: Shared object has no run-time symbol table",
2535 			    obj->path);
2536 		return (-1);
2537 	}
2538 
2539 	if (obj->textrel) {
2540 		/* There are relocations to the write-protected text segment. */
2541 		if (mprotect(obj->mapbase, obj->textsize,
2542 		    PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
2543 			_rtld_error("%s: Cannot write-enable text segment: %s",
2544 			    obj->path, rtld_strerror(errno));
2545 			return (-1);
2546 		}
2547 	}
2548 
2549 	/* Process the non-PLT relocations. */
2550 	if (reloc_non_plt(obj, rtldobj, flags, lockstate))
2551 		return (-1);
2552 
2553 	if (obj->textrel) {	/* Re-protected the text segment. */
2554 		if (mprotect(obj->mapbase, obj->textsize,
2555 		    PROT_READ|PROT_EXEC) == -1) {
2556 			_rtld_error("%s: Cannot write-protect text segment: %s",
2557 			    obj->path, rtld_strerror(errno));
2558 			return (-1);
2559 		}
2560 	}
2561 
2562 
2563 	/* Set the special PLT or GOT entries. */
2564 	init_pltgot(obj);
2565 
2566 	/* Process the PLT relocations. */
2567 	if (reloc_plt(obj) == -1)
2568 		return (-1);
2569 	/* Relocate the jump slots if we are doing immediate binding. */
2570 	if (obj->bind_now || bind_now)
2571 		if (reloc_jmpslots(obj, flags, lockstate) == -1)
2572 			return (-1);
2573 
2574 	if (obj->relro_size > 0) {
2575 		if (mprotect(obj->relro_page, obj->relro_size,
2576 		    PROT_READ) == -1) {
2577 			_rtld_error("%s: Cannot enforce relro protection: %s",
2578 			    obj->path, rtld_strerror(errno));
2579 			return (-1);
2580 		}
2581 	}
2582 
2583 	/*
2584 	 * Set up the magic number and version in the Obj_Entry.  These
2585 	 * were checked in the crt1.o from the original ElfKit, so we
2586 	 * set them for backward compatibility.
2587 	 */
2588 	obj->magic = RTLD_MAGIC;
2589 	obj->version = RTLD_VERSION;
2590 
2591 	return (0);
2592 }
2593 
2594 /*
2595  * Relocate newly-loaded shared objects.  The argument is a pointer to
2596  * the Obj_Entry for the first such object.  All objects from the first
2597  * to the end of the list of objects are relocated.  Returns 0 on success,
2598  * or -1 on failure.
2599  */
2600 static int
2601 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
2602     int flags, RtldLockState *lockstate)
2603 {
2604 	Obj_Entry *obj;
2605 	int error;
2606 
2607 	for (error = 0, obj = first;  obj != NULL;  obj = obj->next) {
2608 		error = relocate_object(obj, bind_now, rtldobj, flags,
2609 		    lockstate);
2610 		if (error == -1)
2611 			break;
2612 	}
2613 	return (error);
2614 }
2615 
2616 /*
2617  * The handling of R_MACHINE_IRELATIVE relocations and jumpslots
2618  * referencing STT_GNU_IFUNC symbols is postponed till the other
2619  * relocations are done.  The indirect functions specified as
2620  * ifunc are allowed to call other symbols, so we need to have
2621  * objects relocated before asking for resolution from indirects.
2622  *
2623  * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion,
2624  * instead of the usual lazy handling of PLT slots.  It is
2625  * consistent with how GNU does it.
2626  */
2627 static int
2628 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags,
2629     RtldLockState *lockstate)
2630 {
2631 	if (obj->irelative && reloc_iresolve(obj, lockstate) == -1)
2632 		return (-1);
2633 	if ((obj->bind_now || bind_now) && obj->gnu_ifunc &&
2634 	    reloc_gnu_ifunc(obj, flags, lockstate) == -1)
2635 		return (-1);
2636 	return (0);
2637 }
2638 
2639 static int
2640 resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags,
2641     RtldLockState *lockstate)
2642 {
2643 	Obj_Entry *obj;
2644 
2645 	for (obj = first;  obj != NULL;  obj = obj->next) {
2646 		if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1)
2647 			return (-1);
2648 	}
2649 	return (0);
2650 }
2651 
2652 static int
2653 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags,
2654     RtldLockState *lockstate)
2655 {
2656 	Objlist_Entry *elm;
2657 
2658 	STAILQ_FOREACH(elm, list, link) {
2659 		if (resolve_object_ifunc(elm->obj, bind_now, flags,
2660 		    lockstate) == -1)
2661 			return (-1);
2662 	}
2663 	return (0);
2664 }
2665 
2666 /*
2667  * Cleanup procedure.  It will be called (by the atexit mechanism) just
2668  * before the process exits.
2669  */
2670 static void
2671 rtld_exit(void)
2672 {
2673     RtldLockState lockstate;
2674 
2675     wlock_acquire(rtld_bind_lock, &lockstate);
2676     dbg("rtld_exit()");
2677     objlist_call_fini(&list_fini, NULL, &lockstate);
2678     /* No need to remove the items from the list, since we are exiting. */
2679     if (!libmap_disable)
2680         lm_fini();
2681     lock_release(rtld_bind_lock, &lockstate);
2682 }
2683 
2684 /*
2685  * Iterate over a search path, translate each element, and invoke the
2686  * callback on the result.
2687  */
2688 static void *
2689 path_enumerate(const char *path, path_enum_proc callback, void *arg)
2690 {
2691     const char *trans;
2692     if (path == NULL)
2693 	return (NULL);
2694 
2695     path += strspn(path, ":;");
2696     while (*path != '\0') {
2697 	size_t len;
2698 	char  *res;
2699 
2700 	len = strcspn(path, ":;");
2701 	trans = lm_findn(NULL, path, len);
2702 	if (trans)
2703 	    res = callback(trans, strlen(trans), arg);
2704 	else
2705 	    res = callback(path, len, arg);
2706 
2707 	if (res != NULL)
2708 	    return (res);
2709 
2710 	path += len;
2711 	path += strspn(path, ":;");
2712     }
2713 
2714     return (NULL);
2715 }
2716 
2717 struct try_library_args {
2718     const char	*name;
2719     size_t	 namelen;
2720     char	*buffer;
2721     size_t	 buflen;
2722 };
2723 
2724 static void *
2725 try_library_path(const char *dir, size_t dirlen, void *param)
2726 {
2727     struct try_library_args *arg;
2728 
2729     arg = param;
2730     if (*dir == '/' || trust) {
2731 	char *pathname;
2732 
2733 	if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
2734 		return (NULL);
2735 
2736 	pathname = arg->buffer;
2737 	strncpy(pathname, dir, dirlen);
2738 	pathname[dirlen] = '/';
2739 	strcpy(pathname + dirlen + 1, arg->name);
2740 
2741 	dbg("  Trying \"%s\"", pathname);
2742 	if (access(pathname, F_OK) == 0) {		/* We found it */
2743 	    pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
2744 	    strcpy(pathname, arg->buffer);
2745 	    return (pathname);
2746 	}
2747     }
2748     return (NULL);
2749 }
2750 
2751 static char *
2752 search_library_path(const char *name, const char *path)
2753 {
2754     char *p;
2755     struct try_library_args arg;
2756 
2757     if (path == NULL)
2758 	return NULL;
2759 
2760     arg.name = name;
2761     arg.namelen = strlen(name);
2762     arg.buffer = xmalloc(PATH_MAX);
2763     arg.buflen = PATH_MAX;
2764 
2765     p = path_enumerate(path, try_library_path, &arg);
2766 
2767     free(arg.buffer);
2768 
2769     return (p);
2770 }
2771 
2772 
2773 /*
2774  * Finds the library with the given name using the directory descriptors
2775  * listed in the LD_LIBRARY_PATH_FDS environment variable.
2776  *
2777  * Returns a freshly-opened close-on-exec file descriptor for the library,
2778  * or -1 if the library cannot be found.
2779  */
2780 static char *
2781 search_library_pathfds(const char *name, const char *path, int *fdp)
2782 {
2783 	char *envcopy, *fdstr, *found, *last_token;
2784 	size_t len;
2785 	int dirfd, fd;
2786 
2787 	dbg("%s('%s', '%s', fdp)\n", __func__, name, path);
2788 
2789 	/* Don't load from user-specified libdirs into setuid binaries. */
2790 	if (!trust)
2791 		return (NULL);
2792 
2793 	/* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */
2794 	if (path == NULL)
2795 		return (NULL);
2796 
2797 	/* LD_LIBRARY_PATH_FDS only works with relative paths. */
2798 	if (name[0] == '/') {
2799 		dbg("Absolute path (%s) passed to %s", name, __func__);
2800 		return (NULL);
2801 	}
2802 
2803 	/*
2804 	 * Use strtok_r() to walk the FD:FD:FD list.  This requires a local
2805 	 * copy of the path, as strtok_r rewrites separator tokens
2806 	 * with '\0'.
2807 	 */
2808 	found = NULL;
2809 	envcopy = xstrdup(path);
2810 	for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL;
2811 	    fdstr = strtok_r(NULL, ":", &last_token)) {
2812 		dirfd = parse_libdir(fdstr);
2813 		if (dirfd < 0)
2814 			break;
2815 		fd = openat(dirfd, name, O_RDONLY | O_CLOEXEC);
2816 		if (fd >= 0) {
2817 			*fdp = fd;
2818 			len = strlen(fdstr) + strlen(name) + 3;
2819 			found = xmalloc(len);
2820 			if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) {
2821 				_rtld_error("error generating '%d/%s'",
2822 				    dirfd, name);
2823 				die();
2824 			}
2825 			dbg("open('%s') => %d", found, fd);
2826 			break;
2827 		}
2828 	}
2829 	free(envcopy);
2830 
2831 	return (found);
2832 }
2833 
2834 
2835 int
2836 dlclose(void *handle)
2837 {
2838     Obj_Entry *root;
2839     RtldLockState lockstate;
2840 
2841     wlock_acquire(rtld_bind_lock, &lockstate);
2842     root = dlcheck(handle);
2843     if (root == NULL) {
2844 	lock_release(rtld_bind_lock, &lockstate);
2845 	return -1;
2846     }
2847     LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
2848 	root->path);
2849 
2850     /* Unreference the object and its dependencies. */
2851     root->dl_refcount--;
2852 
2853     if (root->refcount == 1) {
2854 	/*
2855 	 * The object will be no longer referenced, so we must unload it.
2856 	 * First, call the fini functions.
2857 	 */
2858 	objlist_call_fini(&list_fini, root, &lockstate);
2859 
2860 	unref_dag(root);
2861 
2862 	/* Finish cleaning up the newly-unreferenced objects. */
2863 	GDB_STATE(RT_DELETE,&root->linkmap);
2864 	unload_object(root);
2865 	GDB_STATE(RT_CONSISTENT,NULL);
2866     } else
2867 	unref_dag(root);
2868 
2869     LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
2870     lock_release(rtld_bind_lock, &lockstate);
2871     return 0;
2872 }
2873 
2874 char *
2875 dlerror(void)
2876 {
2877     char *msg = error_message;
2878     error_message = NULL;
2879     return msg;
2880 }
2881 
2882 /*
2883  * This function is deprecated and has no effect.
2884  */
2885 void
2886 dllockinit(void *context,
2887 	   void *(*lock_create)(void *context),
2888            void (*rlock_acquire)(void *lock),
2889            void (*wlock_acquire)(void *lock),
2890            void (*lock_release)(void *lock),
2891            void (*lock_destroy)(void *lock),
2892 	   void (*context_destroy)(void *context))
2893 {
2894     static void *cur_context;
2895     static void (*cur_context_destroy)(void *);
2896 
2897     /* Just destroy the context from the previous call, if necessary. */
2898     if (cur_context_destroy != NULL)
2899 	cur_context_destroy(cur_context);
2900     cur_context = context;
2901     cur_context_destroy = context_destroy;
2902 }
2903 
2904 void *
2905 dlopen(const char *name, int mode)
2906 {
2907 
2908 	return (rtld_dlopen(name, -1, mode));
2909 }
2910 
2911 void *
2912 fdlopen(int fd, int mode)
2913 {
2914 
2915 	return (rtld_dlopen(NULL, fd, mode));
2916 }
2917 
2918 static void *
2919 rtld_dlopen(const char *name, int fd, int mode)
2920 {
2921     RtldLockState lockstate;
2922     int lo_flags;
2923 
2924     LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
2925     ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
2926     if (ld_tracing != NULL) {
2927 	rlock_acquire(rtld_bind_lock, &lockstate);
2928 	if (sigsetjmp(lockstate.env, 0) != 0)
2929 	    lock_upgrade(rtld_bind_lock, &lockstate);
2930 	environ = (char **)*get_program_var_addr("environ", &lockstate);
2931 	lock_release(rtld_bind_lock, &lockstate);
2932     }
2933     lo_flags = RTLD_LO_DLOPEN;
2934     if (mode & RTLD_NODELETE)
2935 	    lo_flags |= RTLD_LO_NODELETE;
2936     if (mode & RTLD_NOLOAD)
2937 	    lo_flags |= RTLD_LO_NOLOAD;
2938     if (ld_tracing != NULL)
2939 	    lo_flags |= RTLD_LO_TRACE;
2940 
2941     return (dlopen_object(name, fd, obj_main, lo_flags,
2942       mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL));
2943 }
2944 
2945 static void
2946 dlopen_cleanup(Obj_Entry *obj)
2947 {
2948 
2949 	obj->dl_refcount--;
2950 	unref_dag(obj);
2951 	if (obj->refcount == 0)
2952 		unload_object(obj);
2953 }
2954 
2955 static Obj_Entry *
2956 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags,
2957     int mode, RtldLockState *lockstate)
2958 {
2959     Obj_Entry **old_obj_tail;
2960     Obj_Entry *obj;
2961     Objlist initlist;
2962     RtldLockState mlockstate;
2963     int result;
2964 
2965     objlist_init(&initlist);
2966 
2967     if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) {
2968 	wlock_acquire(rtld_bind_lock, &mlockstate);
2969 	lockstate = &mlockstate;
2970     }
2971     GDB_STATE(RT_ADD,NULL);
2972 
2973     old_obj_tail = obj_tail;
2974     obj = NULL;
2975     if (name == NULL && fd == -1) {
2976 	obj = obj_main;
2977 	obj->refcount++;
2978     } else {
2979 	obj = load_object(name, fd, refobj, lo_flags);
2980     }
2981 
2982     if (obj) {
2983 	obj->dl_refcount++;
2984 	if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
2985 	    objlist_push_tail(&list_global, obj);
2986 	if (*old_obj_tail != NULL) {		/* We loaded something new. */
2987 	    assert(*old_obj_tail == obj);
2988 	    result = load_needed_objects(obj,
2989 		lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY));
2990 	    init_dag(obj);
2991 	    ref_dag(obj);
2992 	    if (result != -1)
2993 		result = rtld_verify_versions(&obj->dagmembers);
2994 	    if (result != -1 && ld_tracing)
2995 		goto trace;
2996 	    if (result == -1 || relocate_object_dag(obj,
2997 	      (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld,
2998 	      (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
2999 	      lockstate) == -1) {
3000 		dlopen_cleanup(obj);
3001 		obj = NULL;
3002 	    } else if (lo_flags & RTLD_LO_EARLY) {
3003 		/*
3004 		 * Do not call the init functions for early loaded
3005 		 * filtees.  The image is still not initialized enough
3006 		 * for them to work.
3007 		 *
3008 		 * Our object is found by the global object list and
3009 		 * will be ordered among all init calls done right
3010 		 * before transferring control to main.
3011 		 */
3012 	    } else {
3013 		/* Make list of init functions to call. */
3014 		initlist_add_objects(obj, &obj->next, &initlist);
3015 	    }
3016 	    /*
3017 	     * Process all no_delete objects here, given them own
3018 	     * DAGs to prevent their dependencies from being unloaded.
3019 	     * This has to be done after we have loaded all of the
3020 	     * dependencies, so that we do not miss any.
3021 	     */
3022 	    if (obj != NULL)
3023 		process_nodelete(obj);
3024 	} else {
3025 	    /*
3026 	     * Bump the reference counts for objects on this DAG.  If
3027 	     * this is the first dlopen() call for the object that was
3028 	     * already loaded as a dependency, initialize the dag
3029 	     * starting at it.
3030 	     */
3031 	    init_dag(obj);
3032 	    ref_dag(obj);
3033 
3034 	    if ((lo_flags & RTLD_LO_TRACE) != 0)
3035 		goto trace;
3036 	}
3037 	if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
3038 	  obj->z_nodelete) && !obj->ref_nodel) {
3039 	    dbg("obj %s nodelete", obj->path);
3040 	    ref_dag(obj);
3041 	    obj->z_nodelete = obj->ref_nodel = true;
3042 	}
3043     }
3044 
3045     LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
3046 	name);
3047     GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
3048 
3049     if (!(lo_flags & RTLD_LO_EARLY)) {
3050 	map_stacks_exec(lockstate);
3051     }
3052 
3053     if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW,
3054       (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
3055       lockstate) == -1) {
3056 	objlist_clear(&initlist);
3057 	dlopen_cleanup(obj);
3058 	if (lockstate == &mlockstate)
3059 	    lock_release(rtld_bind_lock, lockstate);
3060 	return (NULL);
3061     }
3062 
3063     if (!(lo_flags & RTLD_LO_EARLY)) {
3064 	/* Call the init functions. */
3065 	objlist_call_init(&initlist, lockstate);
3066     }
3067     objlist_clear(&initlist);
3068     if (lockstate == &mlockstate)
3069 	lock_release(rtld_bind_lock, lockstate);
3070     return obj;
3071 trace:
3072     trace_loaded_objects(obj);
3073     if (lockstate == &mlockstate)
3074 	lock_release(rtld_bind_lock, lockstate);
3075     exit(0);
3076 }
3077 
3078 static void *
3079 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
3080     int flags)
3081 {
3082     DoneList donelist;
3083     const Obj_Entry *obj, *defobj;
3084     const Elf_Sym *def;
3085     SymLook req;
3086     RtldLockState lockstate;
3087     tls_index ti;
3088     int res;
3089 
3090     def = NULL;
3091     defobj = NULL;
3092     symlook_init(&req, name);
3093     req.ventry = ve;
3094     req.flags = flags | SYMLOOK_IN_PLT;
3095     req.lockstate = &lockstate;
3096 
3097     rlock_acquire(rtld_bind_lock, &lockstate);
3098     if (sigsetjmp(lockstate.env, 0) != 0)
3099 	    lock_upgrade(rtld_bind_lock, &lockstate);
3100     if (handle == NULL || handle == RTLD_NEXT ||
3101 	handle == RTLD_DEFAULT || handle == RTLD_SELF) {
3102 
3103 	if ((obj = obj_from_addr(retaddr)) == NULL) {
3104 	    _rtld_error("Cannot determine caller's shared object");
3105 	    lock_release(rtld_bind_lock, &lockstate);
3106 	    return NULL;
3107 	}
3108 	if (handle == NULL) {	/* Just the caller's shared object. */
3109 	    res = symlook_obj(&req, obj);
3110 	    if (res == 0) {
3111 		def = req.sym_out;
3112 		defobj = req.defobj_out;
3113 	    }
3114 	} else if (handle == RTLD_NEXT || /* Objects after caller's */
3115 		   handle == RTLD_SELF) { /* ... caller included */
3116 	    if (handle == RTLD_NEXT)
3117 		obj = obj->next;
3118 	    for (; obj != NULL; obj = obj->next) {
3119 		res = symlook_obj(&req, obj);
3120 		if (res == 0) {
3121 		    if (def == NULL ||
3122 		      ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) {
3123 			def = req.sym_out;
3124 			defobj = req.defobj_out;
3125 			if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3126 			    break;
3127 		    }
3128 		}
3129 	    }
3130 	    /*
3131 	     * Search the dynamic linker itself, and possibly resolve the
3132 	     * symbol from there.  This is how the application links to
3133 	     * dynamic linker services such as dlopen.
3134 	     */
3135 	    if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3136 		res = symlook_obj(&req, &obj_rtld);
3137 		if (res == 0) {
3138 		    def = req.sym_out;
3139 		    defobj = req.defobj_out;
3140 		}
3141 	    }
3142 	} else {
3143 	    assert(handle == RTLD_DEFAULT);
3144 	    res = symlook_default(&req, obj);
3145 	    if (res == 0) {
3146 		defobj = req.defobj_out;
3147 		def = req.sym_out;
3148 	    }
3149 	}
3150     } else {
3151 	if ((obj = dlcheck(handle)) == NULL) {
3152 	    lock_release(rtld_bind_lock, &lockstate);
3153 	    return NULL;
3154 	}
3155 
3156 	donelist_init(&donelist);
3157 	if (obj->mainprog) {
3158             /* Handle obtained by dlopen(NULL, ...) implies global scope. */
3159 	    res = symlook_global(&req, &donelist);
3160 	    if (res == 0) {
3161 		def = req.sym_out;
3162 		defobj = req.defobj_out;
3163 	    }
3164 	    /*
3165 	     * Search the dynamic linker itself, and possibly resolve the
3166 	     * symbol from there.  This is how the application links to
3167 	     * dynamic linker services such as dlopen.
3168 	     */
3169 	    if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3170 		res = symlook_obj(&req, &obj_rtld);
3171 		if (res == 0) {
3172 		    def = req.sym_out;
3173 		    defobj = req.defobj_out;
3174 		}
3175 	    }
3176 	}
3177 	else {
3178 	    /* Search the whole DAG rooted at the given object. */
3179 	    res = symlook_list(&req, &obj->dagmembers, &donelist);
3180 	    if (res == 0) {
3181 		def = req.sym_out;
3182 		defobj = req.defobj_out;
3183 	    }
3184 	}
3185     }
3186 
3187     if (def != NULL) {
3188 	lock_release(rtld_bind_lock, &lockstate);
3189 
3190 	/*
3191 	 * The value required by the caller is derived from the value
3192 	 * of the symbol. this is simply the relocated value of the
3193 	 * symbol.
3194 	 */
3195 	if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
3196 	    return (make_function_pointer(def, defobj));
3197 	else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
3198 	    return (rtld_resolve_ifunc(defobj, def));
3199 	else if (ELF_ST_TYPE(def->st_info) == STT_TLS) {
3200 	    ti.ti_module = defobj->tlsindex;
3201 	    ti.ti_offset = def->st_value;
3202 	    return (__tls_get_addr(&ti));
3203 	} else
3204 	    return (defobj->relocbase + def->st_value);
3205     }
3206 
3207     _rtld_error("Undefined symbol \"%s\"", name);
3208     lock_release(rtld_bind_lock, &lockstate);
3209     return NULL;
3210 }
3211 
3212 void *
3213 dlsym(void *handle, const char *name)
3214 {
3215 	return do_dlsym(handle, name, __builtin_return_address(0), NULL,
3216 	    SYMLOOK_DLSYM);
3217 }
3218 
3219 dlfunc_t
3220 dlfunc(void *handle, const char *name)
3221 {
3222 	union {
3223 		void *d;
3224 		dlfunc_t f;
3225 	} rv;
3226 
3227 	rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
3228 	    SYMLOOK_DLSYM);
3229 	return (rv.f);
3230 }
3231 
3232 void *
3233 dlvsym(void *handle, const char *name, const char *version)
3234 {
3235 	Ver_Entry ventry;
3236 
3237 	ventry.name = version;
3238 	ventry.file = NULL;
3239 	ventry.hash = elf_hash(version);
3240 	ventry.flags= 0;
3241 	return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
3242 	    SYMLOOK_DLSYM);
3243 }
3244 
3245 int
3246 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
3247 {
3248     const Obj_Entry *obj;
3249     RtldLockState lockstate;
3250 
3251     rlock_acquire(rtld_bind_lock, &lockstate);
3252     obj = obj_from_addr(addr);
3253     if (obj == NULL) {
3254         _rtld_error("No shared object contains address");
3255 	lock_release(rtld_bind_lock, &lockstate);
3256         return (0);
3257     }
3258     rtld_fill_dl_phdr_info(obj, phdr_info);
3259     lock_release(rtld_bind_lock, &lockstate);
3260     return (1);
3261 }
3262 
3263 int
3264 dladdr(const void *addr, Dl_info *info)
3265 {
3266     const Obj_Entry *obj;
3267     const Elf_Sym *def;
3268     void *symbol_addr;
3269     unsigned long symoffset;
3270     RtldLockState lockstate;
3271 
3272     rlock_acquire(rtld_bind_lock, &lockstate);
3273     obj = obj_from_addr(addr);
3274     if (obj == NULL) {
3275         _rtld_error("No shared object contains address");
3276 	lock_release(rtld_bind_lock, &lockstate);
3277         return 0;
3278     }
3279     info->dli_fname = obj->path;
3280     info->dli_fbase = obj->mapbase;
3281     info->dli_saddr = (void *)0;
3282     info->dli_sname = NULL;
3283 
3284     /*
3285      * Walk the symbol list looking for the symbol whose address is
3286      * closest to the address sent in.
3287      */
3288     for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) {
3289         def = obj->symtab + symoffset;
3290 
3291         /*
3292          * For skip the symbol if st_shndx is either SHN_UNDEF or
3293          * SHN_COMMON.
3294          */
3295         if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
3296             continue;
3297 
3298         /*
3299          * If the symbol is greater than the specified address, or if it
3300          * is further away from addr than the current nearest symbol,
3301          * then reject it.
3302          */
3303         symbol_addr = obj->relocbase + def->st_value;
3304         if (symbol_addr > addr || symbol_addr < info->dli_saddr)
3305             continue;
3306 
3307         /* Update our idea of the nearest symbol. */
3308         info->dli_sname = obj->strtab + def->st_name;
3309         info->dli_saddr = symbol_addr;
3310 
3311         /* Exact match? */
3312         if (info->dli_saddr == addr)
3313             break;
3314     }
3315     lock_release(rtld_bind_lock, &lockstate);
3316     return 1;
3317 }
3318 
3319 int
3320 dlinfo(void *handle, int request, void *p)
3321 {
3322     const Obj_Entry *obj;
3323     RtldLockState lockstate;
3324     int error;
3325 
3326     rlock_acquire(rtld_bind_lock, &lockstate);
3327 
3328     if (handle == NULL || handle == RTLD_SELF) {
3329 	void *retaddr;
3330 
3331 	retaddr = __builtin_return_address(0);	/* __GNUC__ only */
3332 	if ((obj = obj_from_addr(retaddr)) == NULL)
3333 	    _rtld_error("Cannot determine caller's shared object");
3334     } else
3335 	obj = dlcheck(handle);
3336 
3337     if (obj == NULL) {
3338 	lock_release(rtld_bind_lock, &lockstate);
3339 	return (-1);
3340     }
3341 
3342     error = 0;
3343     switch (request) {
3344     case RTLD_DI_LINKMAP:
3345 	*((struct link_map const **)p) = &obj->linkmap;
3346 	break;
3347     case RTLD_DI_ORIGIN:
3348 	error = rtld_dirname(obj->path, p);
3349 	break;
3350 
3351     case RTLD_DI_SERINFOSIZE:
3352     case RTLD_DI_SERINFO:
3353 	error = do_search_info(obj, request, (struct dl_serinfo *)p);
3354 	break;
3355 
3356     default:
3357 	_rtld_error("Invalid request %d passed to dlinfo()", request);
3358 	error = -1;
3359     }
3360 
3361     lock_release(rtld_bind_lock, &lockstate);
3362 
3363     return (error);
3364 }
3365 
3366 static void
3367 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
3368 {
3369 
3370 	phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
3371 	phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ?
3372 	    STAILQ_FIRST(&obj->names)->name : obj->path;
3373 	phdr_info->dlpi_phdr = obj->phdr;
3374 	phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
3375 	phdr_info->dlpi_tls_modid = obj->tlsindex;
3376 	phdr_info->dlpi_tls_data = obj->tlsinit;
3377 	phdr_info->dlpi_adds = obj_loads;
3378 	phdr_info->dlpi_subs = obj_loads - obj_count;
3379 }
3380 
3381 int
3382 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
3383 {
3384     struct dl_phdr_info phdr_info;
3385     const Obj_Entry *obj;
3386     RtldLockState bind_lockstate, phdr_lockstate;
3387     int error;
3388 
3389     wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
3390     rlock_acquire(rtld_bind_lock, &bind_lockstate);
3391 
3392     error = 0;
3393 
3394     for (obj = obj_list;  obj != NULL;  obj = obj->next) {
3395 	rtld_fill_dl_phdr_info(obj, &phdr_info);
3396 	if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0)
3397 		break;
3398 
3399     }
3400     if (error == 0) {
3401 	rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info);
3402 	error = callback(&phdr_info, sizeof(phdr_info), param);
3403     }
3404 
3405     lock_release(rtld_bind_lock, &bind_lockstate);
3406     lock_release(rtld_phdr_lock, &phdr_lockstate);
3407 
3408     return (error);
3409 }
3410 
3411 static void *
3412 fill_search_info(const char *dir, size_t dirlen, void *param)
3413 {
3414     struct fill_search_info_args *arg;
3415 
3416     arg = param;
3417 
3418     if (arg->request == RTLD_DI_SERINFOSIZE) {
3419 	arg->serinfo->dls_cnt ++;
3420 	arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1;
3421     } else {
3422 	struct dl_serpath *s_entry;
3423 
3424 	s_entry = arg->serpath;
3425 	s_entry->dls_name  = arg->strspace;
3426 	s_entry->dls_flags = arg->flags;
3427 
3428 	strncpy(arg->strspace, dir, dirlen);
3429 	arg->strspace[dirlen] = '\0';
3430 
3431 	arg->strspace += dirlen + 1;
3432 	arg->serpath++;
3433     }
3434 
3435     return (NULL);
3436 }
3437 
3438 static int
3439 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
3440 {
3441     struct dl_serinfo _info;
3442     struct fill_search_info_args args;
3443 
3444     args.request = RTLD_DI_SERINFOSIZE;
3445     args.serinfo = &_info;
3446 
3447     _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
3448     _info.dls_cnt  = 0;
3449 
3450     path_enumerate(obj->rpath, fill_search_info, &args);
3451     path_enumerate(ld_library_path, fill_search_info, &args);
3452     path_enumerate(obj->runpath, fill_search_info, &args);
3453     path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args);
3454     if (!obj->z_nodeflib)
3455       path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
3456 
3457 
3458     if (request == RTLD_DI_SERINFOSIZE) {
3459 	info->dls_size = _info.dls_size;
3460 	info->dls_cnt = _info.dls_cnt;
3461 	return (0);
3462     }
3463 
3464     if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
3465 	_rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
3466 	return (-1);
3467     }
3468 
3469     args.request  = RTLD_DI_SERINFO;
3470     args.serinfo  = info;
3471     args.serpath  = &info->dls_serpath[0];
3472     args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
3473 
3474     args.flags = LA_SER_RUNPATH;
3475     if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
3476 	return (-1);
3477 
3478     args.flags = LA_SER_LIBPATH;
3479     if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
3480 	return (-1);
3481 
3482     args.flags = LA_SER_RUNPATH;
3483     if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL)
3484 	return (-1);
3485 
3486     args.flags = LA_SER_CONFIG;
3487     if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args)
3488       != NULL)
3489 	return (-1);
3490 
3491     args.flags = LA_SER_DEFAULT;
3492     if (!obj->z_nodeflib &&
3493       path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
3494 	return (-1);
3495     return (0);
3496 }
3497 
3498 static int
3499 rtld_dirname(const char *path, char *bname)
3500 {
3501     const char *endp;
3502 
3503     /* Empty or NULL string gets treated as "." */
3504     if (path == NULL || *path == '\0') {
3505 	bname[0] = '.';
3506 	bname[1] = '\0';
3507 	return (0);
3508     }
3509 
3510     /* Strip trailing slashes */
3511     endp = path + strlen(path) - 1;
3512     while (endp > path && *endp == '/')
3513 	endp--;
3514 
3515     /* Find the start of the dir */
3516     while (endp > path && *endp != '/')
3517 	endp--;
3518 
3519     /* Either the dir is "/" or there are no slashes */
3520     if (endp == path) {
3521 	bname[0] = *endp == '/' ? '/' : '.';
3522 	bname[1] = '\0';
3523 	return (0);
3524     } else {
3525 	do {
3526 	    endp--;
3527 	} while (endp > path && *endp == '/');
3528     }
3529 
3530     if (endp - path + 2 > PATH_MAX)
3531     {
3532 	_rtld_error("Filename is too long: %s", path);
3533 	return(-1);
3534     }
3535 
3536     strncpy(bname, path, endp - path + 1);
3537     bname[endp - path + 1] = '\0';
3538     return (0);
3539 }
3540 
3541 static int
3542 rtld_dirname_abs(const char *path, char *base)
3543 {
3544 	char base_rel[PATH_MAX];
3545 
3546 	if (rtld_dirname(path, base) == -1)
3547 		return (-1);
3548 	if (base[0] == '/')
3549 		return (0);
3550 	if (getcwd(base_rel, sizeof(base_rel)) == NULL ||
3551 	    strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) ||
3552 	    strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel))
3553 		return (-1);
3554 	strcpy(base, base_rel);
3555 	return (0);
3556 }
3557 
3558 static void
3559 linkmap_add(Obj_Entry *obj)
3560 {
3561     struct link_map *l = &obj->linkmap;
3562     struct link_map *prev;
3563 
3564     obj->linkmap.l_name = obj->path;
3565     obj->linkmap.l_addr = obj->mapbase;
3566     obj->linkmap.l_ld = obj->dynamic;
3567 #ifdef __mips__
3568     /* GDB needs load offset on MIPS to use the symbols */
3569     obj->linkmap.l_offs = obj->relocbase;
3570 #endif
3571 
3572     if (r_debug.r_map == NULL) {
3573 	r_debug.r_map = l;
3574 	return;
3575     }
3576 
3577     /*
3578      * Scan to the end of the list, but not past the entry for the
3579      * dynamic linker, which we want to keep at the very end.
3580      */
3581     for (prev = r_debug.r_map;
3582       prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
3583       prev = prev->l_next)
3584 	;
3585 
3586     /* Link in the new entry. */
3587     l->l_prev = prev;
3588     l->l_next = prev->l_next;
3589     if (l->l_next != NULL)
3590 	l->l_next->l_prev = l;
3591     prev->l_next = l;
3592 }
3593 
3594 static void
3595 linkmap_delete(Obj_Entry *obj)
3596 {
3597     struct link_map *l = &obj->linkmap;
3598 
3599     if (l->l_prev == NULL) {
3600 	if ((r_debug.r_map = l->l_next) != NULL)
3601 	    l->l_next->l_prev = NULL;
3602 	return;
3603     }
3604 
3605     if ((l->l_prev->l_next = l->l_next) != NULL)
3606 	l->l_next->l_prev = l->l_prev;
3607 }
3608 
3609 /*
3610  * Function for the debugger to set a breakpoint on to gain control.
3611  *
3612  * The two parameters allow the debugger to easily find and determine
3613  * what the runtime loader is doing and to whom it is doing it.
3614  *
3615  * When the loadhook trap is hit (r_debug_state, set at program
3616  * initialization), the arguments can be found on the stack:
3617  *
3618  *  +8   struct link_map *m
3619  *  +4   struct r_debug  *rd
3620  *  +0   RetAddr
3621  */
3622 void
3623 r_debug_state(struct r_debug* rd, struct link_map *m)
3624 {
3625     /*
3626      * The following is a hack to force the compiler to emit calls to
3627      * this function, even when optimizing.  If the function is empty,
3628      * the compiler is not obliged to emit any code for calls to it,
3629      * even when marked __noinline.  However, gdb depends on those
3630      * calls being made.
3631      */
3632     __compiler_membar();
3633 }
3634 
3635 /*
3636  * A function called after init routines have completed. This can be used to
3637  * break before a program's entry routine is called, and can be used when
3638  * main is not available in the symbol table.
3639  */
3640 void
3641 _r_debug_postinit(struct link_map *m)
3642 {
3643 
3644 	/* See r_debug_state(). */
3645 	__compiler_membar();
3646 }
3647 
3648 /*
3649  * Get address of the pointer variable in the main program.
3650  * Prefer non-weak symbol over the weak one.
3651  */
3652 static const void **
3653 get_program_var_addr(const char *name, RtldLockState *lockstate)
3654 {
3655     SymLook req;
3656     DoneList donelist;
3657 
3658     symlook_init(&req, name);
3659     req.lockstate = lockstate;
3660     donelist_init(&donelist);
3661     if (symlook_global(&req, &donelist) != 0)
3662 	return (NULL);
3663     if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC)
3664 	return ((const void **)make_function_pointer(req.sym_out,
3665 	  req.defobj_out));
3666     else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC)
3667 	return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out));
3668     else
3669 	return ((const void **)(req.defobj_out->relocbase +
3670 	  req.sym_out->st_value));
3671 }
3672 
3673 /*
3674  * Set a pointer variable in the main program to the given value.  This
3675  * is used to set key variables such as "environ" before any of the
3676  * init functions are called.
3677  */
3678 static void
3679 set_program_var(const char *name, const void *value)
3680 {
3681     const void **addr;
3682 
3683     if ((addr = get_program_var_addr(name, NULL)) != NULL) {
3684 	dbg("\"%s\": *%p <-- %p", name, addr, value);
3685 	*addr = value;
3686     }
3687 }
3688 
3689 /*
3690  * Search the global objects, including dependencies and main object,
3691  * for the given symbol.
3692  */
3693 static int
3694 symlook_global(SymLook *req, DoneList *donelist)
3695 {
3696     SymLook req1;
3697     const Objlist_Entry *elm;
3698     int res;
3699 
3700     symlook_init_from_req(&req1, req);
3701 
3702     /* Search all objects loaded at program start up. */
3703     if (req->defobj_out == NULL ||
3704       ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
3705 	res = symlook_list(&req1, &list_main, donelist);
3706 	if (res == 0 && (req->defobj_out == NULL ||
3707 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3708 	    req->sym_out = req1.sym_out;
3709 	    req->defobj_out = req1.defobj_out;
3710 	    assert(req->defobj_out != NULL);
3711 	}
3712     }
3713 
3714     /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
3715     STAILQ_FOREACH(elm, &list_global, link) {
3716 	if (req->defobj_out != NULL &&
3717 	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
3718 	    break;
3719 	res = symlook_list(&req1, &elm->obj->dagmembers, donelist);
3720 	if (res == 0 && (req->defobj_out == NULL ||
3721 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3722 	    req->sym_out = req1.sym_out;
3723 	    req->defobj_out = req1.defobj_out;
3724 	    assert(req->defobj_out != NULL);
3725 	}
3726     }
3727 
3728     return (req->sym_out != NULL ? 0 : ESRCH);
3729 }
3730 
3731 /*
3732  * Given a symbol name in a referencing object, find the corresponding
3733  * definition of the symbol.  Returns a pointer to the symbol, or NULL if
3734  * no definition was found.  Returns a pointer to the Obj_Entry of the
3735  * defining object via the reference parameter DEFOBJ_OUT.
3736  */
3737 static int
3738 symlook_default(SymLook *req, const Obj_Entry *refobj)
3739 {
3740     DoneList donelist;
3741     const Objlist_Entry *elm;
3742     SymLook req1;
3743     int res;
3744 
3745     donelist_init(&donelist);
3746     symlook_init_from_req(&req1, req);
3747 
3748     /* Look first in the referencing object if linked symbolically. */
3749     if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
3750 	res = symlook_obj(&req1, refobj);
3751 	if (res == 0) {
3752 	    req->sym_out = req1.sym_out;
3753 	    req->defobj_out = req1.defobj_out;
3754 	    assert(req->defobj_out != NULL);
3755 	}
3756     }
3757 
3758     symlook_global(req, &donelist);
3759 
3760     /* Search all dlopened DAGs containing the referencing object. */
3761     STAILQ_FOREACH(elm, &refobj->dldags, link) {
3762 	if (req->sym_out != NULL &&
3763 	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
3764 	    break;
3765 	res = symlook_list(&req1, &elm->obj->dagmembers, &donelist);
3766 	if (res == 0 && (req->sym_out == NULL ||
3767 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3768 	    req->sym_out = req1.sym_out;
3769 	    req->defobj_out = req1.defobj_out;
3770 	    assert(req->defobj_out != NULL);
3771 	}
3772     }
3773 
3774     /*
3775      * Search the dynamic linker itself, and possibly resolve the
3776      * symbol from there.  This is how the application links to
3777      * dynamic linker services such as dlopen.
3778      */
3779     if (req->sym_out == NULL ||
3780       ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
3781 	res = symlook_obj(&req1, &obj_rtld);
3782 	if (res == 0) {
3783 	    req->sym_out = req1.sym_out;
3784 	    req->defobj_out = req1.defobj_out;
3785 	    assert(req->defobj_out != NULL);
3786 	}
3787     }
3788 
3789     return (req->sym_out != NULL ? 0 : ESRCH);
3790 }
3791 
3792 static int
3793 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp)
3794 {
3795     const Elf_Sym *def;
3796     const Obj_Entry *defobj;
3797     const Objlist_Entry *elm;
3798     SymLook req1;
3799     int res;
3800 
3801     def = NULL;
3802     defobj = NULL;
3803     STAILQ_FOREACH(elm, objlist, link) {
3804 	if (donelist_check(dlp, elm->obj))
3805 	    continue;
3806 	symlook_init_from_req(&req1, req);
3807 	if ((res = symlook_obj(&req1, elm->obj)) == 0) {
3808 	    if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
3809 		def = req1.sym_out;
3810 		defobj = req1.defobj_out;
3811 		if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3812 		    break;
3813 	    }
3814 	}
3815     }
3816     if (def != NULL) {
3817 	req->sym_out = def;
3818 	req->defobj_out = defobj;
3819 	return (0);
3820     }
3821     return (ESRCH);
3822 }
3823 
3824 /*
3825  * Search the chain of DAGS cointed to by the given Needed_Entry
3826  * for a symbol of the given name.  Each DAG is scanned completely
3827  * before advancing to the next one.  Returns a pointer to the symbol,
3828  * or NULL if no definition was found.
3829  */
3830 static int
3831 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp)
3832 {
3833     const Elf_Sym *def;
3834     const Needed_Entry *n;
3835     const Obj_Entry *defobj;
3836     SymLook req1;
3837     int res;
3838 
3839     def = NULL;
3840     defobj = NULL;
3841     symlook_init_from_req(&req1, req);
3842     for (n = needed; n != NULL; n = n->next) {
3843 	if (n->obj == NULL ||
3844 	    (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0)
3845 	    continue;
3846 	if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
3847 	    def = req1.sym_out;
3848 	    defobj = req1.defobj_out;
3849 	    if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3850 		break;
3851 	}
3852     }
3853     if (def != NULL) {
3854 	req->sym_out = def;
3855 	req->defobj_out = defobj;
3856 	return (0);
3857     }
3858     return (ESRCH);
3859 }
3860 
3861 /*
3862  * Search the symbol table of a single shared object for a symbol of
3863  * the given name and version, if requested.  Returns a pointer to the
3864  * symbol, or NULL if no definition was found.  If the object is
3865  * filter, return filtered symbol from filtee.
3866  *
3867  * The symbol's hash value is passed in for efficiency reasons; that
3868  * eliminates many recomputations of the hash value.
3869  */
3870 int
3871 symlook_obj(SymLook *req, const Obj_Entry *obj)
3872 {
3873     DoneList donelist;
3874     SymLook req1;
3875     int flags, res, mres;
3876 
3877     /*
3878      * If there is at least one valid hash at this point, we prefer to
3879      * use the faster GNU version if available.
3880      */
3881     if (obj->valid_hash_gnu)
3882 	mres = symlook_obj1_gnu(req, obj);
3883     else if (obj->valid_hash_sysv)
3884 	mres = symlook_obj1_sysv(req, obj);
3885     else
3886 	return (EINVAL);
3887 
3888     if (mres == 0) {
3889 	if (obj->needed_filtees != NULL) {
3890 	    flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
3891 	    load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
3892 	    donelist_init(&donelist);
3893 	    symlook_init_from_req(&req1, req);
3894 	    res = symlook_needed(&req1, obj->needed_filtees, &donelist);
3895 	    if (res == 0) {
3896 		req->sym_out = req1.sym_out;
3897 		req->defobj_out = req1.defobj_out;
3898 	    }
3899 	    return (res);
3900 	}
3901 	if (obj->needed_aux_filtees != NULL) {
3902 	    flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
3903 	    load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
3904 	    donelist_init(&donelist);
3905 	    symlook_init_from_req(&req1, req);
3906 	    res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist);
3907 	    if (res == 0) {
3908 		req->sym_out = req1.sym_out;
3909 		req->defobj_out = req1.defobj_out;
3910 		return (res);
3911 	    }
3912 	}
3913     }
3914     return (mres);
3915 }
3916 
3917 /* Symbol match routine common to both hash functions */
3918 static bool
3919 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result,
3920     const unsigned long symnum)
3921 {
3922 	Elf_Versym verndx;
3923 	const Elf_Sym *symp;
3924 	const char *strp;
3925 
3926 	symp = obj->symtab + symnum;
3927 	strp = obj->strtab + symp->st_name;
3928 
3929 	switch (ELF_ST_TYPE(symp->st_info)) {
3930 	case STT_FUNC:
3931 	case STT_NOTYPE:
3932 	case STT_OBJECT:
3933 	case STT_COMMON:
3934 	case STT_GNU_IFUNC:
3935 		if (symp->st_value == 0)
3936 			return (false);
3937 		/* fallthrough */
3938 	case STT_TLS:
3939 		if (symp->st_shndx != SHN_UNDEF)
3940 			break;
3941 #ifndef __mips__
3942 		else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
3943 		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
3944 			break;
3945 		/* fallthrough */
3946 #endif
3947 	default:
3948 		return (false);
3949 	}
3950 	if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0)
3951 		return (false);
3952 
3953 	if (req->ventry == NULL) {
3954 		if (obj->versyms != NULL) {
3955 			verndx = VER_NDX(obj->versyms[symnum]);
3956 			if (verndx > obj->vernum) {
3957 				_rtld_error(
3958 				    "%s: symbol %s references wrong version %d",
3959 				    obj->path, obj->strtab + symnum, verndx);
3960 				return (false);
3961 			}
3962 			/*
3963 			 * If we are not called from dlsym (i.e. this
3964 			 * is a normal relocation from unversioned
3965 			 * binary), accept the symbol immediately if
3966 			 * it happens to have first version after this
3967 			 * shared object became versioned.  Otherwise,
3968 			 * if symbol is versioned and not hidden,
3969 			 * remember it. If it is the only symbol with
3970 			 * this name exported by the shared object, it
3971 			 * will be returned as a match by the calling
3972 			 * function. If symbol is global (verndx < 2)
3973 			 * accept it unconditionally.
3974 			 */
3975 			if ((req->flags & SYMLOOK_DLSYM) == 0 &&
3976 			    verndx == VER_NDX_GIVEN) {
3977 				result->sym_out = symp;
3978 				return (true);
3979 			}
3980 			else if (verndx >= VER_NDX_GIVEN) {
3981 				if ((obj->versyms[symnum] & VER_NDX_HIDDEN)
3982 				    == 0) {
3983 					if (result->vsymp == NULL)
3984 						result->vsymp = symp;
3985 					result->vcount++;
3986 				}
3987 				return (false);
3988 			}
3989 		}
3990 		result->sym_out = symp;
3991 		return (true);
3992 	}
3993 	if (obj->versyms == NULL) {
3994 		if (object_match_name(obj, req->ventry->name)) {
3995 			_rtld_error("%s: object %s should provide version %s "
3996 			    "for symbol %s", obj_rtld.path, obj->path,
3997 			    req->ventry->name, obj->strtab + symnum);
3998 			return (false);
3999 		}
4000 	} else {
4001 		verndx = VER_NDX(obj->versyms[symnum]);
4002 		if (verndx > obj->vernum) {
4003 			_rtld_error("%s: symbol %s references wrong version %d",
4004 			    obj->path, obj->strtab + symnum, verndx);
4005 			return (false);
4006 		}
4007 		if (obj->vertab[verndx].hash != req->ventry->hash ||
4008 		    strcmp(obj->vertab[verndx].name, req->ventry->name)) {
4009 			/*
4010 			 * Version does not match. Look if this is a
4011 			 * global symbol and if it is not hidden. If
4012 			 * global symbol (verndx < 2) is available,
4013 			 * use it. Do not return symbol if we are
4014 			 * called by dlvsym, because dlvsym looks for
4015 			 * a specific version and default one is not
4016 			 * what dlvsym wants.
4017 			 */
4018 			if ((req->flags & SYMLOOK_DLSYM) ||
4019 			    (verndx >= VER_NDX_GIVEN) ||
4020 			    (obj->versyms[symnum] & VER_NDX_HIDDEN))
4021 				return (false);
4022 		}
4023 	}
4024 	result->sym_out = symp;
4025 	return (true);
4026 }
4027 
4028 /*
4029  * Search for symbol using SysV hash function.
4030  * obj->buckets is known not to be NULL at this point; the test for this was
4031  * performed with the obj->valid_hash_sysv assignment.
4032  */
4033 static int
4034 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj)
4035 {
4036 	unsigned long symnum;
4037 	Sym_Match_Result matchres;
4038 
4039 	matchres.sym_out = NULL;
4040 	matchres.vsymp = NULL;
4041 	matchres.vcount = 0;
4042 
4043 	for (symnum = obj->buckets[req->hash % obj->nbuckets];
4044 	    symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
4045 		if (symnum >= obj->nchains)
4046 			return (ESRCH);	/* Bad object */
4047 
4048 		if (matched_symbol(req, obj, &matchres, symnum)) {
4049 			req->sym_out = matchres.sym_out;
4050 			req->defobj_out = obj;
4051 			return (0);
4052 		}
4053 	}
4054 	if (matchres.vcount == 1) {
4055 		req->sym_out = matchres.vsymp;
4056 		req->defobj_out = obj;
4057 		return (0);
4058 	}
4059 	return (ESRCH);
4060 }
4061 
4062 /* Search for symbol using GNU hash function */
4063 static int
4064 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj)
4065 {
4066 	Elf_Addr bloom_word;
4067 	const Elf32_Word *hashval;
4068 	Elf32_Word bucket;
4069 	Sym_Match_Result matchres;
4070 	unsigned int h1, h2;
4071 	unsigned long symnum;
4072 
4073 	matchres.sym_out = NULL;
4074 	matchres.vsymp = NULL;
4075 	matchres.vcount = 0;
4076 
4077 	/* Pick right bitmask word from Bloom filter array */
4078 	bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) &
4079 	    obj->maskwords_bm_gnu];
4080 
4081 	/* Calculate modulus word size of gnu hash and its derivative */
4082 	h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1);
4083 	h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1));
4084 
4085 	/* Filter out the "definitely not in set" queries */
4086 	if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0)
4087 		return (ESRCH);
4088 
4089 	/* Locate hash chain and corresponding value element*/
4090 	bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu];
4091 	if (bucket == 0)
4092 		return (ESRCH);
4093 	hashval = &obj->chain_zero_gnu[bucket];
4094 	do {
4095 		if (((*hashval ^ req->hash_gnu) >> 1) == 0) {
4096 			symnum = hashval - obj->chain_zero_gnu;
4097 			if (matched_symbol(req, obj, &matchres, symnum)) {
4098 				req->sym_out = matchres.sym_out;
4099 				req->defobj_out = obj;
4100 				return (0);
4101 			}
4102 		}
4103 	} while ((*hashval++ & 1) == 0);
4104 	if (matchres.vcount == 1) {
4105 		req->sym_out = matchres.vsymp;
4106 		req->defobj_out = obj;
4107 		return (0);
4108 	}
4109 	return (ESRCH);
4110 }
4111 
4112 static void
4113 trace_loaded_objects(Obj_Entry *obj)
4114 {
4115     char	*fmt1, *fmt2, *fmt, *main_local, *list_containers;
4116     int		c;
4117 
4118     if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
4119 	main_local = "";
4120 
4121     if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL)
4122 	fmt1 = "\t%o => %p (%x)\n";
4123 
4124     if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL)
4125 	fmt2 = "\t%o (%x)\n";
4126 
4127     list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL");
4128 
4129     for (; obj; obj = obj->next) {
4130 	Needed_Entry		*needed;
4131 	char			*name, *path;
4132 	bool			is_lib;
4133 
4134 	if (list_containers && obj->needed != NULL)
4135 	    rtld_printf("%s:\n", obj->path);
4136 	for (needed = obj->needed; needed; needed = needed->next) {
4137 	    if (needed->obj != NULL) {
4138 		if (needed->obj->traced && !list_containers)
4139 		    continue;
4140 		needed->obj->traced = true;
4141 		path = needed->obj->path;
4142 	    } else
4143 		path = "not found";
4144 
4145 	    name = (char *)obj->strtab + needed->name;
4146 	    is_lib = strncmp(name, "lib", 3) == 0;	/* XXX - bogus */
4147 
4148 	    fmt = is_lib ? fmt1 : fmt2;
4149 	    while ((c = *fmt++) != '\0') {
4150 		switch (c) {
4151 		default:
4152 		    rtld_putchar(c);
4153 		    continue;
4154 		case '\\':
4155 		    switch (c = *fmt) {
4156 		    case '\0':
4157 			continue;
4158 		    case 'n':
4159 			rtld_putchar('\n');
4160 			break;
4161 		    case 't':
4162 			rtld_putchar('\t');
4163 			break;
4164 		    }
4165 		    break;
4166 		case '%':
4167 		    switch (c = *fmt) {
4168 		    case '\0':
4169 			continue;
4170 		    case '%':
4171 		    default:
4172 			rtld_putchar(c);
4173 			break;
4174 		    case 'A':
4175 			rtld_putstr(main_local);
4176 			break;
4177 		    case 'a':
4178 			rtld_putstr(obj_main->path);
4179 			break;
4180 		    case 'o':
4181 			rtld_putstr(name);
4182 			break;
4183 #if 0
4184 		    case 'm':
4185 			rtld_printf("%d", sodp->sod_major);
4186 			break;
4187 		    case 'n':
4188 			rtld_printf("%d", sodp->sod_minor);
4189 			break;
4190 #endif
4191 		    case 'p':
4192 			rtld_putstr(path);
4193 			break;
4194 		    case 'x':
4195 			rtld_printf("%p", needed->obj ? needed->obj->mapbase :
4196 			  0);
4197 			break;
4198 		    }
4199 		    break;
4200 		}
4201 		++fmt;
4202 	    }
4203 	}
4204     }
4205 }
4206 
4207 /*
4208  * Unload a dlopened object and its dependencies from memory and from
4209  * our data structures.  It is assumed that the DAG rooted in the
4210  * object has already been unreferenced, and that the object has a
4211  * reference count of 0.
4212  */
4213 static void
4214 unload_object(Obj_Entry *root)
4215 {
4216     Obj_Entry *obj;
4217     Obj_Entry **linkp;
4218 
4219     assert(root->refcount == 0);
4220 
4221     /*
4222      * Pass over the DAG removing unreferenced objects from
4223      * appropriate lists.
4224      */
4225     unlink_object(root);
4226 
4227     /* Unmap all objects that are no longer referenced. */
4228     linkp = &obj_list->next;
4229     while ((obj = *linkp) != NULL) {
4230 	if (obj->refcount == 0) {
4231 	    LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
4232 		obj->path);
4233 	    dbg("unloading \"%s\"", obj->path);
4234 	    unload_filtees(root);
4235 	    munmap(obj->mapbase, obj->mapsize);
4236 	    linkmap_delete(obj);
4237 	    *linkp = obj->next;
4238 	    obj_count--;
4239 	    obj_free(obj);
4240 	} else
4241 	    linkp = &obj->next;
4242     }
4243     obj_tail = linkp;
4244 }
4245 
4246 static void
4247 unlink_object(Obj_Entry *root)
4248 {
4249     Objlist_Entry *elm;
4250 
4251     if (root->refcount == 0) {
4252 	/* Remove the object from the RTLD_GLOBAL list. */
4253 	objlist_remove(&list_global, root);
4254 
4255     	/* Remove the object from all objects' DAG lists. */
4256     	STAILQ_FOREACH(elm, &root->dagmembers, link) {
4257 	    objlist_remove(&elm->obj->dldags, root);
4258 	    if (elm->obj != root)
4259 		unlink_object(elm->obj);
4260 	}
4261     }
4262 }
4263 
4264 static void
4265 ref_dag(Obj_Entry *root)
4266 {
4267     Objlist_Entry *elm;
4268 
4269     assert(root->dag_inited);
4270     STAILQ_FOREACH(elm, &root->dagmembers, link)
4271 	elm->obj->refcount++;
4272 }
4273 
4274 static void
4275 unref_dag(Obj_Entry *root)
4276 {
4277     Objlist_Entry *elm;
4278 
4279     assert(root->dag_inited);
4280     STAILQ_FOREACH(elm, &root->dagmembers, link)
4281 	elm->obj->refcount--;
4282 }
4283 
4284 /*
4285  * Common code for MD __tls_get_addr().
4286  */
4287 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline;
4288 static void *
4289 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset)
4290 {
4291     Elf_Addr *newdtv, *dtv;
4292     RtldLockState lockstate;
4293     int to_copy;
4294 
4295     dtv = *dtvp;
4296     /* Check dtv generation in case new modules have arrived */
4297     if (dtv[0] != tls_dtv_generation) {
4298 	wlock_acquire(rtld_bind_lock, &lockstate);
4299 	newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4300 	to_copy = dtv[1];
4301 	if (to_copy > tls_max_index)
4302 	    to_copy = tls_max_index;
4303 	memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
4304 	newdtv[0] = tls_dtv_generation;
4305 	newdtv[1] = tls_max_index;
4306 	free(dtv);
4307 	lock_release(rtld_bind_lock, &lockstate);
4308 	dtv = *dtvp = newdtv;
4309     }
4310 
4311     /* Dynamically allocate module TLS if necessary */
4312     if (dtv[index + 1] == 0) {
4313 	/* Signal safe, wlock will block out signals. */
4314 	wlock_acquire(rtld_bind_lock, &lockstate);
4315 	if (!dtv[index + 1])
4316 	    dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
4317 	lock_release(rtld_bind_lock, &lockstate);
4318     }
4319     return ((void *)(dtv[index + 1] + offset));
4320 }
4321 
4322 void *
4323 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset)
4324 {
4325 	Elf_Addr *dtv;
4326 
4327 	dtv = *dtvp;
4328 	/* Check dtv generation in case new modules have arrived */
4329 	if (__predict_true(dtv[0] == tls_dtv_generation &&
4330 	    dtv[index + 1] != 0))
4331 		return ((void *)(dtv[index + 1] + offset));
4332 	return (tls_get_addr_slow(dtvp, index, offset));
4333 }
4334 
4335 #if defined(__arm__) || defined(__mips__) || defined(__powerpc__)
4336 
4337 /*
4338  * Allocate Static TLS using the Variant I method.
4339  */
4340 void *
4341 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
4342 {
4343     Obj_Entry *obj;
4344     char *tcb;
4345     Elf_Addr **tls;
4346     Elf_Addr *dtv;
4347     Elf_Addr addr;
4348     int i;
4349 
4350     if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
4351 	return (oldtcb);
4352 
4353     assert(tcbsize >= TLS_TCB_SIZE);
4354     tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize);
4355     tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
4356 
4357     if (oldtcb != NULL) {
4358 	memcpy(tls, oldtcb, tls_static_space);
4359 	free(oldtcb);
4360 
4361 	/* Adjust the DTV. */
4362 	dtv = tls[0];
4363 	for (i = 0; i < dtv[1]; i++) {
4364 	    if (dtv[i+2] >= (Elf_Addr)oldtcb &&
4365 		dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
4366 		dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls;
4367 	    }
4368 	}
4369     } else {
4370 	dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4371 	tls[0] = dtv;
4372 	dtv[0] = tls_dtv_generation;
4373 	dtv[1] = tls_max_index;
4374 
4375 	for (obj = objs; obj; obj = obj->next) {
4376 	    if (obj->tlsoffset > 0) {
4377 		addr = (Elf_Addr)tls + obj->tlsoffset;
4378 		if (obj->tlsinitsize > 0)
4379 		    memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
4380 		if (obj->tlssize > obj->tlsinitsize)
4381 		    memset((void*) (addr + obj->tlsinitsize), 0,
4382 			   obj->tlssize - obj->tlsinitsize);
4383 		dtv[obj->tlsindex + 1] = addr;
4384 	    }
4385 	}
4386     }
4387 
4388     return (tcb);
4389 }
4390 
4391 void
4392 free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
4393 {
4394     Elf_Addr *dtv;
4395     Elf_Addr tlsstart, tlsend;
4396     int dtvsize, i;
4397 
4398     assert(tcbsize >= TLS_TCB_SIZE);
4399 
4400     tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE;
4401     tlsend = tlsstart + tls_static_space;
4402 
4403     dtv = *(Elf_Addr **)tlsstart;
4404     dtvsize = dtv[1];
4405     for (i = 0; i < dtvsize; i++) {
4406 	if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
4407 	    free((void*)dtv[i+2]);
4408 	}
4409     }
4410     free(dtv);
4411     free(tcb);
4412 }
4413 
4414 #endif
4415 
4416 #if defined(__i386__) || defined(__amd64__) || defined(__sparc64__)
4417 
4418 /*
4419  * Allocate Static TLS using the Variant II method.
4420  */
4421 void *
4422 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
4423 {
4424     Obj_Entry *obj;
4425     size_t size, ralign;
4426     char *tls;
4427     Elf_Addr *dtv, *olddtv;
4428     Elf_Addr segbase, oldsegbase, addr;
4429     int i;
4430 
4431     ralign = tcbalign;
4432     if (tls_static_max_align > ralign)
4433 	    ralign = tls_static_max_align;
4434     size = round(tls_static_space, ralign) + round(tcbsize, ralign);
4435 
4436     assert(tcbsize >= 2*sizeof(Elf_Addr));
4437     tls = malloc_aligned(size, ralign);
4438     dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4439 
4440     segbase = (Elf_Addr)(tls + round(tls_static_space, ralign));
4441     ((Elf_Addr*)segbase)[0] = segbase;
4442     ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
4443 
4444     dtv[0] = tls_dtv_generation;
4445     dtv[1] = tls_max_index;
4446 
4447     if (oldtls) {
4448 	/*
4449 	 * Copy the static TLS block over whole.
4450 	 */
4451 	oldsegbase = (Elf_Addr) oldtls;
4452 	memcpy((void *)(segbase - tls_static_space),
4453 	       (const void *)(oldsegbase - tls_static_space),
4454 	       tls_static_space);
4455 
4456 	/*
4457 	 * If any dynamic TLS blocks have been created tls_get_addr(),
4458 	 * move them over.
4459 	 */
4460 	olddtv = ((Elf_Addr**)oldsegbase)[1];
4461 	for (i = 0; i < olddtv[1]; i++) {
4462 	    if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) {
4463 		dtv[i+2] = olddtv[i+2];
4464 		olddtv[i+2] = 0;
4465 	    }
4466 	}
4467 
4468 	/*
4469 	 * We assume that this block was the one we created with
4470 	 * allocate_initial_tls().
4471 	 */
4472 	free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
4473     } else {
4474 	for (obj = objs; obj; obj = obj->next) {
4475 	    if (obj->tlsoffset) {
4476 		addr = segbase - obj->tlsoffset;
4477 		memset((void*) (addr + obj->tlsinitsize),
4478 		       0, obj->tlssize - obj->tlsinitsize);
4479 		if (obj->tlsinit)
4480 		    memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
4481 		dtv[obj->tlsindex + 1] = addr;
4482 	    }
4483 	}
4484     }
4485 
4486     return (void*) segbase;
4487 }
4488 
4489 void
4490 free_tls(void *tls, size_t tcbsize, size_t tcbalign)
4491 {
4492     Elf_Addr* dtv;
4493     size_t size, ralign;
4494     int dtvsize, i;
4495     Elf_Addr tlsstart, tlsend;
4496 
4497     /*
4498      * Figure out the size of the initial TLS block so that we can
4499      * find stuff which ___tls_get_addr() allocated dynamically.
4500      */
4501     ralign = tcbalign;
4502     if (tls_static_max_align > ralign)
4503 	    ralign = tls_static_max_align;
4504     size = round(tls_static_space, ralign);
4505 
4506     dtv = ((Elf_Addr**)tls)[1];
4507     dtvsize = dtv[1];
4508     tlsend = (Elf_Addr) tls;
4509     tlsstart = tlsend - size;
4510     for (i = 0; i < dtvsize; i++) {
4511 	if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) {
4512 		free_aligned((void *)dtv[i + 2]);
4513 	}
4514     }
4515 
4516     free_aligned((void *)tlsstart);
4517     free((void*) dtv);
4518 }
4519 
4520 #endif
4521 
4522 /*
4523  * Allocate TLS block for module with given index.
4524  */
4525 void *
4526 allocate_module_tls(int index)
4527 {
4528     Obj_Entry* obj;
4529     char* p;
4530 
4531     for (obj = obj_list; obj; obj = obj->next) {
4532 	if (obj->tlsindex == index)
4533 	    break;
4534     }
4535     if (!obj) {
4536 	_rtld_error("Can't find module with TLS index %d", index);
4537 	die();
4538     }
4539 
4540     p = malloc_aligned(obj->tlssize, obj->tlsalign);
4541     memcpy(p, obj->tlsinit, obj->tlsinitsize);
4542     memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
4543 
4544     return p;
4545 }
4546 
4547 bool
4548 allocate_tls_offset(Obj_Entry *obj)
4549 {
4550     size_t off;
4551 
4552     if (obj->tls_done)
4553 	return true;
4554 
4555     if (obj->tlssize == 0) {
4556 	obj->tls_done = true;
4557 	return true;
4558     }
4559 
4560     if (obj->tlsindex == 1)
4561 	off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
4562     else
4563 	off = calculate_tls_offset(tls_last_offset, tls_last_size,
4564 				   obj->tlssize, obj->tlsalign);
4565 
4566     /*
4567      * If we have already fixed the size of the static TLS block, we
4568      * must stay within that size. When allocating the static TLS, we
4569      * leave a small amount of space spare to be used for dynamically
4570      * loading modules which use static TLS.
4571      */
4572     if (tls_static_space != 0) {
4573 	if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
4574 	    return false;
4575     } else if (obj->tlsalign > tls_static_max_align) {
4576 	    tls_static_max_align = obj->tlsalign;
4577     }
4578 
4579     tls_last_offset = obj->tlsoffset = off;
4580     tls_last_size = obj->tlssize;
4581     obj->tls_done = true;
4582 
4583     return true;
4584 }
4585 
4586 void
4587 free_tls_offset(Obj_Entry *obj)
4588 {
4589 
4590     /*
4591      * If we were the last thing to allocate out of the static TLS
4592      * block, we give our space back to the 'allocator'. This is a
4593      * simplistic workaround to allow libGL.so.1 to be loaded and
4594      * unloaded multiple times.
4595      */
4596     if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
4597 	== calculate_tls_end(tls_last_offset, tls_last_size)) {
4598 	tls_last_offset -= obj->tlssize;
4599 	tls_last_size = 0;
4600     }
4601 }
4602 
4603 void *
4604 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
4605 {
4606     void *ret;
4607     RtldLockState lockstate;
4608 
4609     wlock_acquire(rtld_bind_lock, &lockstate);
4610     ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign);
4611     lock_release(rtld_bind_lock, &lockstate);
4612     return (ret);
4613 }
4614 
4615 void
4616 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
4617 {
4618     RtldLockState lockstate;
4619 
4620     wlock_acquire(rtld_bind_lock, &lockstate);
4621     free_tls(tcb, tcbsize, tcbalign);
4622     lock_release(rtld_bind_lock, &lockstate);
4623 }
4624 
4625 static void
4626 object_add_name(Obj_Entry *obj, const char *name)
4627 {
4628     Name_Entry *entry;
4629     size_t len;
4630 
4631     len = strlen(name);
4632     entry = malloc(sizeof(Name_Entry) + len);
4633 
4634     if (entry != NULL) {
4635 	strcpy(entry->name, name);
4636 	STAILQ_INSERT_TAIL(&obj->names, entry, link);
4637     }
4638 }
4639 
4640 static int
4641 object_match_name(const Obj_Entry *obj, const char *name)
4642 {
4643     Name_Entry *entry;
4644 
4645     STAILQ_FOREACH(entry, &obj->names, link) {
4646 	if (strcmp(name, entry->name) == 0)
4647 	    return (1);
4648     }
4649     return (0);
4650 }
4651 
4652 static Obj_Entry *
4653 locate_dependency(const Obj_Entry *obj, const char *name)
4654 {
4655     const Objlist_Entry *entry;
4656     const Needed_Entry *needed;
4657 
4658     STAILQ_FOREACH(entry, &list_main, link) {
4659 	if (object_match_name(entry->obj, name))
4660 	    return entry->obj;
4661     }
4662 
4663     for (needed = obj->needed;  needed != NULL;  needed = needed->next) {
4664 	if (strcmp(obj->strtab + needed->name, name) == 0 ||
4665 	  (needed->obj != NULL && object_match_name(needed->obj, name))) {
4666 	    /*
4667 	     * If there is DT_NEEDED for the name we are looking for,
4668 	     * we are all set.  Note that object might not be found if
4669 	     * dependency was not loaded yet, so the function can
4670 	     * return NULL here.  This is expected and handled
4671 	     * properly by the caller.
4672 	     */
4673 	    return (needed->obj);
4674 	}
4675     }
4676     _rtld_error("%s: Unexpected inconsistency: dependency %s not found",
4677 	obj->path, name);
4678     die();
4679 }
4680 
4681 static int
4682 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
4683     const Elf_Vernaux *vna)
4684 {
4685     const Elf_Verdef *vd;
4686     const char *vername;
4687 
4688     vername = refobj->strtab + vna->vna_name;
4689     vd = depobj->verdef;
4690     if (vd == NULL) {
4691 	_rtld_error("%s: version %s required by %s not defined",
4692 	    depobj->path, vername, refobj->path);
4693 	return (-1);
4694     }
4695     for (;;) {
4696 	if (vd->vd_version != VER_DEF_CURRENT) {
4697 	    _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
4698 		depobj->path, vd->vd_version);
4699 	    return (-1);
4700 	}
4701 	if (vna->vna_hash == vd->vd_hash) {
4702 	    const Elf_Verdaux *aux = (const Elf_Verdaux *)
4703 		((char *)vd + vd->vd_aux);
4704 	    if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
4705 		return (0);
4706 	}
4707 	if (vd->vd_next == 0)
4708 	    break;
4709 	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4710     }
4711     if (vna->vna_flags & VER_FLG_WEAK)
4712 	return (0);
4713     _rtld_error("%s: version %s required by %s not found",
4714 	depobj->path, vername, refobj->path);
4715     return (-1);
4716 }
4717 
4718 static int
4719 rtld_verify_object_versions(Obj_Entry *obj)
4720 {
4721     const Elf_Verneed *vn;
4722     const Elf_Verdef  *vd;
4723     const Elf_Verdaux *vda;
4724     const Elf_Vernaux *vna;
4725     const Obj_Entry *depobj;
4726     int maxvernum, vernum;
4727 
4728     if (obj->ver_checked)
4729 	return (0);
4730     obj->ver_checked = true;
4731 
4732     maxvernum = 0;
4733     /*
4734      * Walk over defined and required version records and figure out
4735      * max index used by any of them. Do very basic sanity checking
4736      * while there.
4737      */
4738     vn = obj->verneed;
4739     while (vn != NULL) {
4740 	if (vn->vn_version != VER_NEED_CURRENT) {
4741 	    _rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
4742 		obj->path, vn->vn_version);
4743 	    return (-1);
4744 	}
4745 	vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
4746 	for (;;) {
4747 	    vernum = VER_NEED_IDX(vna->vna_other);
4748 	    if (vernum > maxvernum)
4749 		maxvernum = vernum;
4750 	    if (vna->vna_next == 0)
4751 		 break;
4752 	    vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
4753 	}
4754 	if (vn->vn_next == 0)
4755 	    break;
4756 	vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
4757     }
4758 
4759     vd = obj->verdef;
4760     while (vd != NULL) {
4761 	if (vd->vd_version != VER_DEF_CURRENT) {
4762 	    _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
4763 		obj->path, vd->vd_version);
4764 	    return (-1);
4765 	}
4766 	vernum = VER_DEF_IDX(vd->vd_ndx);
4767 	if (vernum > maxvernum)
4768 		maxvernum = vernum;
4769 	if (vd->vd_next == 0)
4770 	    break;
4771 	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4772     }
4773 
4774     if (maxvernum == 0)
4775 	return (0);
4776 
4777     /*
4778      * Store version information in array indexable by version index.
4779      * Verify that object version requirements are satisfied along the
4780      * way.
4781      */
4782     obj->vernum = maxvernum + 1;
4783     obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry));
4784 
4785     vd = obj->verdef;
4786     while (vd != NULL) {
4787 	if ((vd->vd_flags & VER_FLG_BASE) == 0) {
4788 	    vernum = VER_DEF_IDX(vd->vd_ndx);
4789 	    assert(vernum <= maxvernum);
4790 	    vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux);
4791 	    obj->vertab[vernum].hash = vd->vd_hash;
4792 	    obj->vertab[vernum].name = obj->strtab + vda->vda_name;
4793 	    obj->vertab[vernum].file = NULL;
4794 	    obj->vertab[vernum].flags = 0;
4795 	}
4796 	if (vd->vd_next == 0)
4797 	    break;
4798 	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4799     }
4800 
4801     vn = obj->verneed;
4802     while (vn != NULL) {
4803 	depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
4804 	if (depobj == NULL)
4805 	    return (-1);
4806 	vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
4807 	for (;;) {
4808 	    if (check_object_provided_version(obj, depobj, vna))
4809 		return (-1);
4810 	    vernum = VER_NEED_IDX(vna->vna_other);
4811 	    assert(vernum <= maxvernum);
4812 	    obj->vertab[vernum].hash = vna->vna_hash;
4813 	    obj->vertab[vernum].name = obj->strtab + vna->vna_name;
4814 	    obj->vertab[vernum].file = obj->strtab + vn->vn_file;
4815 	    obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ?
4816 		VER_INFO_HIDDEN : 0;
4817 	    if (vna->vna_next == 0)
4818 		 break;
4819 	    vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
4820 	}
4821 	if (vn->vn_next == 0)
4822 	    break;
4823 	vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
4824     }
4825     return 0;
4826 }
4827 
4828 static int
4829 rtld_verify_versions(const Objlist *objlist)
4830 {
4831     Objlist_Entry *entry;
4832     int rc;
4833 
4834     rc = 0;
4835     STAILQ_FOREACH(entry, objlist, link) {
4836 	/*
4837 	 * Skip dummy objects or objects that have their version requirements
4838 	 * already checked.
4839 	 */
4840 	if (entry->obj->strtab == NULL || entry->obj->vertab != NULL)
4841 	    continue;
4842 	if (rtld_verify_object_versions(entry->obj) == -1) {
4843 	    rc = -1;
4844 	    if (ld_tracing == NULL)
4845 		break;
4846 	}
4847     }
4848     if (rc == 0 || ld_tracing != NULL)
4849     	rc = rtld_verify_object_versions(&obj_rtld);
4850     return rc;
4851 }
4852 
4853 const Ver_Entry *
4854 fetch_ventry(const Obj_Entry *obj, unsigned long symnum)
4855 {
4856     Elf_Versym vernum;
4857 
4858     if (obj->vertab) {
4859 	vernum = VER_NDX(obj->versyms[symnum]);
4860 	if (vernum >= obj->vernum) {
4861 	    _rtld_error("%s: symbol %s has wrong verneed value %d",
4862 		obj->path, obj->strtab + symnum, vernum);
4863 	} else if (obj->vertab[vernum].hash != 0) {
4864 	    return &obj->vertab[vernum];
4865 	}
4866     }
4867     return NULL;
4868 }
4869 
4870 int
4871 _rtld_get_stack_prot(void)
4872 {
4873 
4874 	return (stack_prot);
4875 }
4876 
4877 static void
4878 map_stacks_exec(RtldLockState *lockstate)
4879 {
4880 	void (*thr_map_stacks_exec)(void);
4881 
4882 	if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0)
4883 		return;
4884 	thr_map_stacks_exec = (void (*)(void))(uintptr_t)
4885 	    get_program_var_addr("__pthread_map_stacks_exec", lockstate);
4886 	if (thr_map_stacks_exec != NULL) {
4887 		stack_prot |= PROT_EXEC;
4888 		thr_map_stacks_exec();
4889 	}
4890 }
4891 
4892 void
4893 symlook_init(SymLook *dst, const char *name)
4894 {
4895 
4896 	bzero(dst, sizeof(*dst));
4897 	dst->name = name;
4898 	dst->hash = elf_hash(name);
4899 	dst->hash_gnu = gnu_hash(name);
4900 }
4901 
4902 static void
4903 symlook_init_from_req(SymLook *dst, const SymLook *src)
4904 {
4905 
4906 	dst->name = src->name;
4907 	dst->hash = src->hash;
4908 	dst->hash_gnu = src->hash_gnu;
4909 	dst->ventry = src->ventry;
4910 	dst->flags = src->flags;
4911 	dst->defobj_out = NULL;
4912 	dst->sym_out = NULL;
4913 	dst->lockstate = src->lockstate;
4914 }
4915 
4916 
4917 /*
4918  * Parse a file descriptor number without pulling in more of libc (e.g. atoi).
4919  */
4920 static int
4921 parse_libdir(const char *str)
4922 {
4923 	static const int RADIX = 10;  /* XXXJA: possibly support hex? */
4924 	const char *orig;
4925 	int fd;
4926 	char c;
4927 
4928 	orig = str;
4929 	fd = 0;
4930 	for (c = *str; c != '\0'; c = *++str) {
4931 		if (c < '0' || c > '9')
4932 			return (-1);
4933 
4934 		fd *= RADIX;
4935 		fd += c - '0';
4936 	}
4937 
4938 	/* Make sure we actually parsed something. */
4939 	if (str == orig) {
4940 		_rtld_error("failed to parse directory FD from '%s'", str);
4941 		return (-1);
4942 	}
4943 	return (fd);
4944 }
4945 
4946 /*
4947  * Overrides for libc_pic-provided functions.
4948  */
4949 
4950 int
4951 __getosreldate(void)
4952 {
4953 	size_t len;
4954 	int oid[2];
4955 	int error, osrel;
4956 
4957 	if (osreldate != 0)
4958 		return (osreldate);
4959 
4960 	oid[0] = CTL_KERN;
4961 	oid[1] = KERN_OSRELDATE;
4962 	osrel = 0;
4963 	len = sizeof(osrel);
4964 	error = sysctl(oid, 2, &osrel, &len, NULL, 0);
4965 	if (error == 0 && osrel > 0 && len == sizeof(osrel))
4966 		osreldate = osrel;
4967 	return (osreldate);
4968 }
4969 
4970 void
4971 exit(int status)
4972 {
4973 
4974 	_exit(status);
4975 }
4976 
4977 void (*__cleanup)(void);
4978 int __isthreaded = 0;
4979 int _thread_autoinit_dummy_decl = 1;
4980 
4981 /*
4982  * No unresolved symbols for rtld.
4983  */
4984 void
4985 __pthread_cxa_finalize(struct dl_phdr_info *a)
4986 {
4987 }
4988 
4989 void
4990 __stack_chk_fail(void)
4991 {
4992 
4993 	_rtld_error("stack overflow detected; terminated");
4994 	die();
4995 }
4996 __weak_reference(__stack_chk_fail, __stack_chk_fail_local);
4997 
4998 void
4999 __chk_fail(void)
5000 {
5001 
5002 	_rtld_error("buffer overflow detected; terminated");
5003 	die();
5004 }
5005 
5006 const char *
5007 rtld_strerror(int errnum)
5008 {
5009 
5010 	if (errnum < 0 || errnum >= sys_nerr)
5011 		return ("Unknown error");
5012 	return (sys_errlist[errnum]);
5013 }
5014