xref: /freebsd/libexec/rtld-elf/rtld.c (revision c697fb7f7cc9bedc5beee44d35b771c4e87b335a)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
5  * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>.
6  * Copyright 2009-2013 Konstantin Belousov <kib@FreeBSD.ORG>.
7  * Copyright 2012 John Marino <draco@marino.st>.
8  * Copyright 2014-2017 The FreeBSD Foundation
9  * All rights reserved.
10  *
11  * Portions of this software were developed by Konstantin Belousov
12  * under sponsorship from the FreeBSD Foundation.
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  */
34 
35 /*
36  * Dynamic linker for ELF.
37  *
38  * John Polstra <jdp@polstra.com>.
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
43 
44 #include <sys/param.h>
45 #include <sys/mount.h>
46 #include <sys/mman.h>
47 #include <sys/stat.h>
48 #include <sys/sysctl.h>
49 #include <sys/uio.h>
50 #include <sys/utsname.h>
51 #include <sys/ktrace.h>
52 
53 #include <dlfcn.h>
54 #include <err.h>
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <stdarg.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <unistd.h>
62 
63 #include "debug.h"
64 #include "rtld.h"
65 #include "libmap.h"
66 #include "paths.h"
67 #include "rtld_tls.h"
68 #include "rtld_printf.h"
69 #include "rtld_malloc.h"
70 #include "rtld_utrace.h"
71 #include "notes.h"
72 #include "rtld_libc.h"
73 
74 /* Types. */
75 typedef void (*func_ptr_type)(void);
76 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
77 
78 
79 /* Variables that cannot be static: */
80 extern struct r_debug r_debug; /* For GDB */
81 extern int _thread_autoinit_dummy_decl;
82 extern void (*__cleanup)(void);
83 
84 
85 /*
86  * Function declarations.
87  */
88 static const char *basename(const char *);
89 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
90     const Elf_Dyn **, const Elf_Dyn **);
91 static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *,
92     const Elf_Dyn *);
93 static bool digest_dynamic(Obj_Entry *, int);
94 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
95 static void distribute_static_tls(Objlist *, RtldLockState *);
96 static Obj_Entry *dlcheck(void *);
97 static int dlclose_locked(void *, RtldLockState *);
98 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj,
99     int lo_flags, int mode, RtldLockState *lockstate);
100 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
101 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
102 static bool donelist_check(DoneList *, const Obj_Entry *);
103 static void errmsg_restore(char *);
104 static char *errmsg_save(void);
105 static void *fill_search_info(const char *, size_t, void *);
106 static char *find_library(const char *, const Obj_Entry *, int *);
107 static const char *gethints(bool);
108 static void hold_object(Obj_Entry *);
109 static void unhold_object(Obj_Entry *);
110 static void init_dag(Obj_Entry *);
111 static void init_marker(Obj_Entry *);
112 static void init_pagesizes(Elf_Auxinfo **aux_info);
113 static void init_rtld(caddr_t, Elf_Auxinfo **);
114 static void initlist_add_neededs(Needed_Entry *, Objlist *);
115 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *);
116 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *);
117 static void linkmap_add(Obj_Entry *);
118 static void linkmap_delete(Obj_Entry *);
119 static void load_filtees(Obj_Entry *, int flags, RtldLockState *);
120 static void unload_filtees(Obj_Entry *, RtldLockState *);
121 static int load_needed_objects(Obj_Entry *, int);
122 static int load_preload_objects(void);
123 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int);
124 static void map_stacks_exec(RtldLockState *);
125 static int obj_disable_relro(Obj_Entry *);
126 static int obj_enforce_relro(Obj_Entry *);
127 static Obj_Entry *obj_from_addr(const void *);
128 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
129 static void objlist_call_init(Objlist *, RtldLockState *);
130 static void objlist_clear(Objlist *);
131 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
132 static void objlist_init(Objlist *);
133 static void objlist_push_head(Objlist *, Obj_Entry *);
134 static void objlist_push_tail(Objlist *, Obj_Entry *);
135 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *);
136 static void objlist_remove(Objlist *, Obj_Entry *);
137 static int open_binary_fd(const char *argv0, bool search_in_path,
138     const char **binpath_res);
139 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp);
140 static int parse_integer(const char *);
141 static void *path_enumerate(const char *, path_enum_proc, const char *, void *);
142 static void print_usage(const char *argv0);
143 static void release_object(Obj_Entry *);
144 static int relocate_object_dag(Obj_Entry *root, bool bind_now,
145     Obj_Entry *rtldobj, int flags, RtldLockState *lockstate);
146 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
147     int flags, RtldLockState *lockstate);
148 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int,
149     RtldLockState *);
150 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *);
151 static int rtld_dirname(const char *, char *);
152 static int rtld_dirname_abs(const char *, char *);
153 static void *rtld_dlopen(const char *name, int fd, int mode);
154 static void rtld_exit(void);
155 static void rtld_nop_exit(void);
156 static char *search_library_path(const char *, const char *, const char *,
157     int *);
158 static char *search_library_pathfds(const char *, const char *, int *);
159 static const void **get_program_var_addr(const char *, RtldLockState *);
160 static void set_program_var(const char *, const void *);
161 static int symlook_default(SymLook *, const Obj_Entry *refobj);
162 static int symlook_global(SymLook *, DoneList *);
163 static void symlook_init_from_req(SymLook *, const SymLook *);
164 static int symlook_list(SymLook *, const Objlist *, DoneList *);
165 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *);
166 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *);
167 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *);
168 static void trace_loaded_objects(Obj_Entry *);
169 static void unlink_object(Obj_Entry *);
170 static void unload_object(Obj_Entry *, RtldLockState *lockstate);
171 static void unref_dag(Obj_Entry *);
172 static void ref_dag(Obj_Entry *);
173 static char *origin_subst_one(Obj_Entry *, char *, const char *,
174     const char *, bool);
175 static char *origin_subst(Obj_Entry *, const char *);
176 static bool obj_resolve_origin(Obj_Entry *obj);
177 static void preinit_main(void);
178 static int  rtld_verify_versions(const Objlist *);
179 static int  rtld_verify_object_versions(Obj_Entry *);
180 static void object_add_name(Obj_Entry *, const char *);
181 static int  object_match_name(const Obj_Entry *, const char *);
182 static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
183 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
184     struct dl_phdr_info *phdr_info);
185 static uint32_t gnu_hash(const char *);
186 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *,
187     const unsigned long);
188 
189 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported;
190 void _r_debug_postinit(struct link_map *) __noinline __exported;
191 
192 int __sys_openat(int, const char *, int, ...);
193 
194 /*
195  * Data declarations.
196  */
197 static char *error_message;	/* Message for dlerror(), or NULL */
198 struct r_debug r_debug __exported;	/* for GDB; */
199 static bool libmap_disable;	/* Disable libmap */
200 static bool ld_loadfltr;	/* Immediate filters processing */
201 static char *libmap_override;	/* Maps to use in addition to libmap.conf */
202 static bool trust;		/* False for setuid and setgid programs */
203 static bool dangerous_ld_env;	/* True if environment variables have been
204 				   used to affect the libraries loaded */
205 bool ld_bind_not;		/* Disable PLT update */
206 static char *ld_bind_now;	/* Environment variable for immediate binding */
207 static char *ld_debug;		/* Environment variable for debugging */
208 static char *ld_library_path;	/* Environment variable for search path */
209 static char *ld_library_dirs;	/* Environment variable for library descriptors */
210 static char *ld_preload;	/* Environment variable for libraries to
211 				   load first */
212 static const char *ld_elf_hints_path;	/* Environment variable for alternative hints path */
213 static const char *ld_tracing;	/* Called from ldd to print libs */
214 static char *ld_utrace;		/* Use utrace() to log events. */
215 static struct obj_entry_q obj_list;	/* Queue of all loaded objects */
216 static Obj_Entry *obj_main;	/* The main program shared object */
217 static Obj_Entry obj_rtld;	/* The dynamic linker shared object */
218 static unsigned int obj_count;	/* Number of objects in obj_list */
219 static unsigned int obj_loads;	/* Number of loads of objects (gen count) */
220 
221 static Objlist list_global =	/* Objects dlopened with RTLD_GLOBAL */
222   STAILQ_HEAD_INITIALIZER(list_global);
223 static Objlist list_main =	/* Objects loaded at program startup */
224   STAILQ_HEAD_INITIALIZER(list_main);
225 static Objlist list_fini =	/* Objects needing fini() calls */
226   STAILQ_HEAD_INITIALIZER(list_fini);
227 
228 Elf_Sym sym_zero;		/* For resolving undefined weak refs. */
229 
230 #define GDB_STATE(s,m)	r_debug.r_state = s; r_debug_state(&r_debug,m);
231 
232 extern Elf_Dyn _DYNAMIC;
233 #pragma weak _DYNAMIC
234 
235 int dlclose(void *) __exported;
236 char *dlerror(void) __exported;
237 void *dlopen(const char *, int) __exported;
238 void *fdlopen(int, int) __exported;
239 void *dlsym(void *, const char *) __exported;
240 dlfunc_t dlfunc(void *, const char *) __exported;
241 void *dlvsym(void *, const char *, const char *) __exported;
242 int dladdr(const void *, Dl_info *) __exported;
243 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *),
244     void (*)(void *), void (*)(void *), void (*)(void *)) __exported;
245 int dlinfo(void *, int , void *) __exported;
246 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported;
247 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported;
248 int _rtld_get_stack_prot(void) __exported;
249 int _rtld_is_dlopened(void *) __exported;
250 void _rtld_error(const char *, ...) __exported;
251 
252 /* Only here to fix -Wmissing-prototypes warnings */
253 int __getosreldate(void);
254 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp);
255 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff);
256 
257 
258 int npagesizes;
259 static int osreldate;
260 size_t *pagesizes;
261 
262 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC;
263 static int max_stack_flags;
264 
265 /*
266  * Global declarations normally provided by crt1.  The dynamic linker is
267  * not built with crt1, so we have to provide them ourselves.
268  */
269 char *__progname;
270 char **environ;
271 
272 /*
273  * Used to pass argc, argv to init functions.
274  */
275 int main_argc;
276 char **main_argv;
277 
278 /*
279  * Globals to control TLS allocation.
280  */
281 size_t tls_last_offset;		/* Static TLS offset of last module */
282 size_t tls_last_size;		/* Static TLS size of last module */
283 size_t tls_static_space;	/* Static TLS space allocated */
284 static size_t tls_static_max_align;
285 Elf_Addr tls_dtv_generation = 1;	/* Used to detect when dtv size changes */
286 int tls_max_index = 1;		/* Largest module index allocated */
287 
288 static bool ld_library_path_rpath = false;
289 bool ld_fast_sigblock = false;
290 
291 /*
292  * Globals for path names, and such
293  */
294 const char *ld_elf_hints_default = _PATH_ELF_HINTS;
295 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF;
296 const char *ld_path_rtld = _PATH_RTLD;
297 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH;
298 const char *ld_env_prefix = LD_;
299 
300 static void (*rtld_exit_ptr)(void);
301 
302 /*
303  * Fill in a DoneList with an allocation large enough to hold all of
304  * the currently-loaded objects.  Keep this as a macro since it calls
305  * alloca and we want that to occur within the scope of the caller.
306  */
307 #define donelist_init(dlp)					\
308     ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]),	\
309     assert((dlp)->objs != NULL),				\
310     (dlp)->num_alloc = obj_count,				\
311     (dlp)->num_used = 0)
312 
313 #define	LD_UTRACE(e, h, mb, ms, r, n) do {			\
314 	if (ld_utrace != NULL)					\
315 		ld_utrace_log(e, h, mb, ms, r, n);		\
316 } while (0)
317 
318 static void
319 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
320     int refcnt, const char *name)
321 {
322 	struct utrace_rtld ut;
323 	static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG;
324 
325 	memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig));
326 	ut.event = event;
327 	ut.handle = handle;
328 	ut.mapbase = mapbase;
329 	ut.mapsize = mapsize;
330 	ut.refcnt = refcnt;
331 	bzero(ut.name, sizeof(ut.name));
332 	if (name)
333 		strlcpy(ut.name, name, sizeof(ut.name));
334 	utrace(&ut, sizeof(ut));
335 }
336 
337 #ifdef RTLD_VARIANT_ENV_NAMES
338 /*
339  * construct the env variable based on the type of binary that's
340  * running.
341  */
342 static inline const char *
343 _LD(const char *var)
344 {
345 	static char buffer[128];
346 
347 	strlcpy(buffer, ld_env_prefix, sizeof(buffer));
348 	strlcat(buffer, var, sizeof(buffer));
349 	return (buffer);
350 }
351 #else
352 #define _LD(x)	LD_ x
353 #endif
354 
355 /*
356  * Main entry point for dynamic linking.  The first argument is the
357  * stack pointer.  The stack is expected to be laid out as described
358  * in the SVR4 ABI specification, Intel 386 Processor Supplement.
359  * Specifically, the stack pointer points to a word containing
360  * ARGC.  Following that in the stack is a null-terminated sequence
361  * of pointers to argument strings.  Then comes a null-terminated
362  * sequence of pointers to environment strings.  Finally, there is a
363  * sequence of "auxiliary vector" entries.
364  *
365  * The second argument points to a place to store the dynamic linker's
366  * exit procedure pointer and the third to a place to store the main
367  * program's object.
368  *
369  * The return value is the main program's entry point.
370  */
371 func_ptr_type
372 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
373 {
374     Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT];
375     Objlist_Entry *entry;
376     Obj_Entry *last_interposer, *obj, *preload_tail;
377     const Elf_Phdr *phdr;
378     Objlist initlist;
379     RtldLockState lockstate;
380     struct stat st;
381     Elf_Addr *argcp;
382     char **argv, **env, **envp, *kexecpath, *library_path_rpath;
383     const char *argv0, *binpath;
384     caddr_t imgentry;
385     char buf[MAXPATHLEN];
386     int argc, fd, i, phnum, rtld_argc;
387 #ifdef __powerpc__
388     int old_auxv_format = 1;
389 #endif
390     bool dir_enable, explicit_fd, search_in_path;
391 
392     /*
393      * On entry, the dynamic linker itself has not been relocated yet.
394      * Be very careful not to reference any global data until after
395      * init_rtld has returned.  It is OK to reference file-scope statics
396      * and string constants, and to call static and global functions.
397      */
398 
399     /* Find the auxiliary vector on the stack. */
400     argcp = sp;
401     argc = *sp++;
402     argv = (char **) sp;
403     sp += argc + 1;	/* Skip over arguments and NULL terminator */
404     env = (char **) sp;
405     while (*sp++ != 0)	/* Skip over environment, and NULL terminator */
406 	;
407     aux = (Elf_Auxinfo *) sp;
408 
409     /* Digest the auxiliary vector. */
410     for (i = 0;  i < AT_COUNT;  i++)
411 	aux_info[i] = NULL;
412     for (auxp = aux;  auxp->a_type != AT_NULL;  auxp++) {
413 	if (auxp->a_type < AT_COUNT)
414 	    aux_info[auxp->a_type] = auxp;
415 #ifdef __powerpc__
416 	if (auxp->a_type == 23) /* AT_STACKPROT */
417 	    old_auxv_format = 0;
418 #endif
419     }
420 
421 #ifdef __powerpc__
422     if (old_auxv_format) {
423 	/* Remap from old-style auxv numbers. */
424 	aux_info[23] = aux_info[21];	/* AT_STACKPROT */
425 	aux_info[21] = aux_info[19];	/* AT_PAGESIZESLEN */
426 	aux_info[19] = aux_info[17];	/* AT_NCPUS */
427 	aux_info[17] = aux_info[15];	/* AT_CANARYLEN */
428 	aux_info[15] = aux_info[13];	/* AT_EXECPATH */
429 	aux_info[13] = NULL;		/* AT_GID */
430 
431 	aux_info[20] = aux_info[18];	/* AT_PAGESIZES */
432 	aux_info[18] = aux_info[16];	/* AT_OSRELDATE */
433 	aux_info[16] = aux_info[14];	/* AT_CANARY */
434 	aux_info[14] = NULL;		/* AT_EGID */
435     }
436 #endif
437 
438     /* Initialize and relocate ourselves. */
439     assert(aux_info[AT_BASE] != NULL);
440     init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
441 
442     __progname = obj_rtld.path;
443     argv0 = argv[0] != NULL ? argv[0] : "(null)";
444     environ = env;
445     main_argc = argc;
446     main_argv = argv;
447 
448     if (aux_info[AT_BSDFLAGS] != NULL &&
449 	(aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0)
450 	    ld_fast_sigblock = true;
451 
452     trust = !issetugid();
453 
454     md_abi_variant_hook(aux_info);
455 
456     fd = -1;
457     if (aux_info[AT_EXECFD] != NULL) {
458 	fd = aux_info[AT_EXECFD]->a_un.a_val;
459     } else {
460 	assert(aux_info[AT_PHDR] != NULL);
461 	phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr;
462 	if (phdr == obj_rtld.phdr) {
463 	    if (!trust) {
464 		_rtld_error("Tainted process refusing to run binary %s",
465 		    argv0);
466 		rtld_die();
467 	    }
468 	    dbg("opening main program in direct exec mode");
469 	    if (argc >= 2) {
470 		rtld_argc = parse_args(argv, argc, &search_in_path, &fd);
471 		argv0 = argv[rtld_argc];
472 		explicit_fd = (fd != -1);
473 		binpath = NULL;
474 		if (!explicit_fd)
475 		    fd = open_binary_fd(argv0, search_in_path, &binpath);
476 		if (fstat(fd, &st) == -1) {
477 		    _rtld_error("Failed to fstat FD %d (%s): %s", fd,
478 		      explicit_fd ? "user-provided descriptor" : argv0,
479 		      rtld_strerror(errno));
480 		    rtld_die();
481 		}
482 
483 		/*
484 		 * Rough emulation of the permission checks done by
485 		 * execve(2), only Unix DACs are checked, ACLs are
486 		 * ignored.  Preserve the semantic of disabling owner
487 		 * to execute if owner x bit is cleared, even if
488 		 * others x bit is enabled.
489 		 * mmap(2) does not allow to mmap with PROT_EXEC if
490 		 * binary' file comes from noexec mount.  We cannot
491 		 * set a text reference on the binary.
492 		 */
493 		dir_enable = false;
494 		if (st.st_uid == geteuid()) {
495 		    if ((st.st_mode & S_IXUSR) != 0)
496 			dir_enable = true;
497 		} else if (st.st_gid == getegid()) {
498 		    if ((st.st_mode & S_IXGRP) != 0)
499 			dir_enable = true;
500 		} else if ((st.st_mode & S_IXOTH) != 0) {
501 		    dir_enable = true;
502 		}
503 		if (!dir_enable) {
504 		    _rtld_error("No execute permission for binary %s",
505 		        argv0);
506 		    rtld_die();
507 		}
508 
509 		/*
510 		 * For direct exec mode, argv[0] is the interpreter
511 		 * name, we must remove it and shift arguments left
512 		 * before invoking binary main.  Since stack layout
513 		 * places environment pointers and aux vectors right
514 		 * after the terminating NULL, we must shift
515 		 * environment and aux as well.
516 		 */
517 		main_argc = argc - rtld_argc;
518 		for (i = 0; i <= main_argc; i++)
519 		    argv[i] = argv[i + rtld_argc];
520 		*argcp -= rtld_argc;
521 		environ = env = envp = argv + main_argc + 1;
522 		dbg("move env from %p to %p", envp + rtld_argc, envp);
523 		do {
524 		    *envp = *(envp + rtld_argc);
525 		}  while (*envp++ != NULL);
526 		aux = auxp = (Elf_Auxinfo *)envp;
527 		auxpf = (Elf_Auxinfo *)(envp + rtld_argc);
528 		dbg("move aux from %p to %p", auxpf, aux);
529 		/* XXXKIB insert place for AT_EXECPATH if not present */
530 		for (;; auxp++, auxpf++) {
531 		    *auxp = *auxpf;
532 		    if (auxp->a_type == AT_NULL)
533 			    break;
534 		}
535 		/* Since the auxiliary vector has moved, redigest it. */
536 		for (i = 0;  i < AT_COUNT;  i++)
537 		    aux_info[i] = NULL;
538 		for (auxp = aux;  auxp->a_type != AT_NULL;  auxp++) {
539 		    if (auxp->a_type < AT_COUNT)
540 			aux_info[auxp->a_type] = auxp;
541 		}
542 
543 		/* Point AT_EXECPATH auxv and aux_info to the binary path. */
544 		if (binpath == NULL) {
545 		    aux_info[AT_EXECPATH] = NULL;
546 		} else {
547 		    if (aux_info[AT_EXECPATH] == NULL) {
548 			aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo));
549 			aux_info[AT_EXECPATH]->a_type = AT_EXECPATH;
550 		    }
551 		    aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *,
552 		      binpath);
553 		}
554 	    } else {
555 		_rtld_error("No binary");
556 		rtld_die();
557 	    }
558 	}
559     }
560 
561     ld_bind_now = getenv(_LD("BIND_NOW"));
562 
563     /*
564      * If the process is tainted, then we un-set the dangerous environment
565      * variables.  The process will be marked as tainted until setuid(2)
566      * is called.  If any child process calls setuid(2) we do not want any
567      * future processes to honor the potentially un-safe variables.
568      */
569     if (!trust) {
570 	if (unsetenv(_LD("PRELOAD")) || unsetenv(_LD("LIBMAP")) ||
571 	    unsetenv(_LD("LIBRARY_PATH")) || unsetenv(_LD("LIBRARY_PATH_FDS")) ||
572 	    unsetenv(_LD("LIBMAP_DISABLE")) || unsetenv(_LD("BIND_NOT")) ||
573 	    unsetenv(_LD("DEBUG")) || unsetenv(_LD("ELF_HINTS_PATH")) ||
574 	    unsetenv(_LD("LOADFLTR")) || unsetenv(_LD("LIBRARY_PATH_RPATH"))) {
575 		_rtld_error("environment corrupt; aborting");
576 		rtld_die();
577 	}
578     }
579     ld_debug = getenv(_LD("DEBUG"));
580     if (ld_bind_now == NULL)
581 	    ld_bind_not = getenv(_LD("BIND_NOT")) != NULL;
582     libmap_disable = getenv(_LD("LIBMAP_DISABLE")) != NULL;
583     libmap_override = getenv(_LD("LIBMAP"));
584     ld_library_path = getenv(_LD("LIBRARY_PATH"));
585     ld_library_dirs = getenv(_LD("LIBRARY_PATH_FDS"));
586     ld_preload = getenv(_LD("PRELOAD"));
587     ld_elf_hints_path = getenv(_LD("ELF_HINTS_PATH"));
588     ld_loadfltr = getenv(_LD("LOADFLTR")) != NULL;
589     library_path_rpath = getenv(_LD("LIBRARY_PATH_RPATH"));
590     if (library_path_rpath != NULL) {
591 	    if (library_path_rpath[0] == 'y' ||
592 		library_path_rpath[0] == 'Y' ||
593 		library_path_rpath[0] == '1')
594 		    ld_library_path_rpath = true;
595 	    else
596 		    ld_library_path_rpath = false;
597     }
598     dangerous_ld_env = libmap_disable || (libmap_override != NULL) ||
599 	(ld_library_path != NULL) || (ld_preload != NULL) ||
600 	(ld_elf_hints_path != NULL) || ld_loadfltr;
601     ld_tracing = getenv(_LD("TRACE_LOADED_OBJECTS"));
602     ld_utrace = getenv(_LD("UTRACE"));
603 
604     if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
605 	ld_elf_hints_path = ld_elf_hints_default;
606 
607     if (ld_debug != NULL && *ld_debug != '\0')
608 	debug = 1;
609     dbg("%s is initialized, base address = %p", __progname,
610 	(caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
611     dbg("RTLD dynamic = %p", obj_rtld.dynamic);
612     dbg("RTLD pltgot  = %p", obj_rtld.pltgot);
613 
614     dbg("initializing thread locks");
615     lockdflt_init();
616 
617     /*
618      * Load the main program, or process its program header if it is
619      * already loaded.
620      */
621     if (fd != -1) {	/* Load the main program. */
622 	dbg("loading main program");
623 	obj_main = map_object(fd, argv0, NULL);
624 	close(fd);
625 	if (obj_main == NULL)
626 	    rtld_die();
627 	max_stack_flags = obj_main->stack_flags;
628     } else {				/* Main program already loaded. */
629 	dbg("processing main program's program header");
630 	assert(aux_info[AT_PHDR] != NULL);
631 	phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
632 	assert(aux_info[AT_PHNUM] != NULL);
633 	phnum = aux_info[AT_PHNUM]->a_un.a_val;
634 	assert(aux_info[AT_PHENT] != NULL);
635 	assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
636 	assert(aux_info[AT_ENTRY] != NULL);
637 	imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
638 	if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL)
639 	    rtld_die();
640     }
641 
642     if (aux_info[AT_EXECPATH] != NULL && fd == -1) {
643 	    kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
644 	    dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
645 	    if (kexecpath[0] == '/')
646 		    obj_main->path = kexecpath;
647 	    else if (getcwd(buf, sizeof(buf)) == NULL ||
648 		     strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
649 		     strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
650 		    obj_main->path = xstrdup(argv0);
651 	    else
652 		    obj_main->path = xstrdup(buf);
653     } else {
654 	    dbg("No AT_EXECPATH or direct exec");
655 	    obj_main->path = xstrdup(argv0);
656     }
657     dbg("obj_main path %s", obj_main->path);
658     obj_main->mainprog = true;
659 
660     if (aux_info[AT_STACKPROT] != NULL &&
661       aux_info[AT_STACKPROT]->a_un.a_val != 0)
662 	    stack_prot = aux_info[AT_STACKPROT]->a_un.a_val;
663 
664 #ifndef COMPAT_32BIT
665     /*
666      * Get the actual dynamic linker pathname from the executable if
667      * possible.  (It should always be possible.)  That ensures that
668      * gdb will find the right dynamic linker even if a non-standard
669      * one is being used.
670      */
671     if (obj_main->interp != NULL &&
672       strcmp(obj_main->interp, obj_rtld.path) != 0) {
673 	free(obj_rtld.path);
674 	obj_rtld.path = xstrdup(obj_main->interp);
675         __progname = obj_rtld.path;
676     }
677 #endif
678 
679     if (!digest_dynamic(obj_main, 0))
680 	rtld_die();
681     dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d",
682 	obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu,
683 	obj_main->dynsymcount);
684 
685     linkmap_add(obj_main);
686     linkmap_add(&obj_rtld);
687 
688     /* Link the main program into the list of objects. */
689     TAILQ_INSERT_HEAD(&obj_list, obj_main, next);
690     obj_count++;
691     obj_loads++;
692 
693     /* Initialize a fake symbol for resolving undefined weak references. */
694     sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
695     sym_zero.st_shndx = SHN_UNDEF;
696     sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
697 
698     if (!libmap_disable)
699         libmap_disable = (bool)lm_init(libmap_override);
700 
701     dbg("loading LD_PRELOAD libraries");
702     if (load_preload_objects() == -1)
703 	rtld_die();
704     preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q));
705 
706     dbg("loading needed objects");
707     if (load_needed_objects(obj_main, 0) == -1)
708 	rtld_die();
709 
710     /* Make a list of all objects loaded at startup. */
711     last_interposer = obj_main;
712     TAILQ_FOREACH(obj, &obj_list, next) {
713 	if (obj->marker)
714 	    continue;
715 	if (obj->z_interpose && obj != obj_main) {
716 	    objlist_put_after(&list_main, last_interposer, obj);
717 	    last_interposer = obj;
718 	} else {
719 	    objlist_push_tail(&list_main, obj);
720 	}
721     	obj->refcount++;
722     }
723 
724     dbg("checking for required versions");
725     if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
726 	rtld_die();
727 
728     if (ld_tracing) {		/* We're done */
729 	trace_loaded_objects(obj_main);
730 	exit(0);
731     }
732 
733     if (getenv(_LD("DUMP_REL_PRE")) != NULL) {
734        dump_relocations(obj_main);
735        exit (0);
736     }
737 
738     /*
739      * Processing tls relocations requires having the tls offsets
740      * initialized.  Prepare offsets before starting initial
741      * relocation processing.
742      */
743     dbg("initializing initial thread local storage offsets");
744     STAILQ_FOREACH(entry, &list_main, link) {
745 	/*
746 	 * Allocate all the initial objects out of the static TLS
747 	 * block even if they didn't ask for it.
748 	 */
749 	allocate_tls_offset(entry->obj);
750     }
751 
752     if (relocate_objects(obj_main,
753       ld_bind_now != NULL && *ld_bind_now != '\0',
754       &obj_rtld, SYMLOOK_EARLY, NULL) == -1)
755 	rtld_die();
756 
757     dbg("doing copy relocations");
758     if (do_copy_relocations(obj_main) == -1)
759 	rtld_die();
760 
761     if (getenv(_LD("DUMP_REL_POST")) != NULL) {
762        dump_relocations(obj_main);
763        exit (0);
764     }
765 
766     ifunc_init(aux);
767 
768     /*
769      * Setup TLS for main thread.  This must be done after the
770      * relocations are processed, since tls initialization section
771      * might be the subject for relocations.
772      */
773     dbg("initializing initial thread local storage");
774     allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list)));
775 
776     dbg("initializing key program variables");
777     set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
778     set_program_var("environ", env);
779     set_program_var("__elf_aux_vector", aux);
780 
781     /* Make a list of init functions to call. */
782     objlist_init(&initlist);
783     initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)),
784       preload_tail, &initlist);
785 
786     r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
787 
788     map_stacks_exec(NULL);
789 
790     if (!obj_main->crt_no_init) {
791 	/*
792 	 * Make sure we don't call the main program's init and fini
793 	 * functions for binaries linked with old crt1 which calls
794 	 * _init itself.
795 	 */
796 	obj_main->init = obj_main->fini = (Elf_Addr)NULL;
797 	obj_main->preinit_array = obj_main->init_array =
798 	    obj_main->fini_array = (Elf_Addr)NULL;
799     }
800 
801     /*
802      * Execute MD initializers required before we call the objects'
803      * init functions.
804      */
805     pre_init();
806 
807     wlock_acquire(rtld_bind_lock, &lockstate);
808 
809     dbg("resolving ifuncs");
810     if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL &&
811       *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1)
812 	rtld_die();
813 
814     rtld_exit_ptr = rtld_exit;
815     if (obj_main->crt_no_init)
816 	preinit_main();
817     objlist_call_init(&initlist, &lockstate);
818     _r_debug_postinit(&obj_main->linkmap);
819     objlist_clear(&initlist);
820     dbg("loading filtees");
821     TAILQ_FOREACH(obj, &obj_list, next) {
822 	if (obj->marker)
823 	    continue;
824 	if (ld_loadfltr || obj->z_loadfltr)
825 	    load_filtees(obj, 0, &lockstate);
826     }
827 
828     dbg("enforcing main obj relro");
829     if (obj_enforce_relro(obj_main) == -1)
830 	rtld_die();
831 
832     lock_release(rtld_bind_lock, &lockstate);
833 
834     dbg("transferring control to program entry point = %p", obj_main->entry);
835 
836     /* Return the exit procedure and the program entry point. */
837     *exit_proc = rtld_exit_ptr;
838     *objp = obj_main;
839     return (func_ptr_type) obj_main->entry;
840 }
841 
842 void *
843 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def)
844 {
845 	void *ptr;
846 	Elf_Addr target;
847 
848 	ptr = (void *)make_function_pointer(def, obj);
849 	target = call_ifunc_resolver(ptr);
850 	return ((void *)target);
851 }
852 
853 /*
854  * NB: MIPS uses a private version of this function (_mips_rtld_bind).
855  * Changes to this function should be applied there as well.
856  */
857 Elf_Addr
858 _rtld_bind(Obj_Entry *obj, Elf_Size reloff)
859 {
860     const Elf_Rel *rel;
861     const Elf_Sym *def;
862     const Obj_Entry *defobj;
863     Elf_Addr *where;
864     Elf_Addr target;
865     RtldLockState lockstate;
866 
867     rlock_acquire(rtld_bind_lock, &lockstate);
868     if (sigsetjmp(lockstate.env, 0) != 0)
869 	    lock_upgrade(rtld_bind_lock, &lockstate);
870     if (obj->pltrel)
871 	rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff);
872     else
873 	rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff);
874 
875     where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
876     def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT,
877 	NULL, &lockstate);
878     if (def == NULL)
879 	rtld_die();
880     if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
881 	target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
882     else
883 	target = (Elf_Addr)(defobj->relocbase + def->st_value);
884 
885     dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
886       defobj->strtab + def->st_name, basename(obj->path),
887       (void *)target, basename(defobj->path));
888 
889     /*
890      * Write the new contents for the jmpslot. Note that depending on
891      * architecture, the value which we need to return back to the
892      * lazy binding trampoline may or may not be the target
893      * address. The value returned from reloc_jmpslot() is the value
894      * that the trampoline needs.
895      */
896     target = reloc_jmpslot(where, target, defobj, obj, rel);
897     lock_release(rtld_bind_lock, &lockstate);
898     return target;
899 }
900 
901 /*
902  * Error reporting function.  Use it like printf.  If formats the message
903  * into a buffer, and sets things up so that the next call to dlerror()
904  * will return the message.
905  */
906 void
907 _rtld_error(const char *fmt, ...)
908 {
909     static char buf[512];
910     va_list ap;
911 
912     va_start(ap, fmt);
913     rtld_vsnprintf(buf, sizeof buf, fmt, ap);
914     error_message = buf;
915     va_end(ap);
916     LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, error_message);
917 }
918 
919 /*
920  * Return a dynamically-allocated copy of the current error message, if any.
921  */
922 static char *
923 errmsg_save(void)
924 {
925     return error_message == NULL ? NULL : xstrdup(error_message);
926 }
927 
928 /*
929  * Restore the current error message from a copy which was previously saved
930  * by errmsg_save().  The copy is freed.
931  */
932 static void
933 errmsg_restore(char *saved_msg)
934 {
935     if (saved_msg == NULL)
936 	error_message = NULL;
937     else {
938 	_rtld_error("%s", saved_msg);
939 	free(saved_msg);
940     }
941 }
942 
943 static const char *
944 basename(const char *name)
945 {
946     const char *p = strrchr(name, '/');
947     return p != NULL ? p + 1 : name;
948 }
949 
950 static struct utsname uts;
951 
952 static char *
953 origin_subst_one(Obj_Entry *obj, char *real, const char *kw,
954     const char *subst, bool may_free)
955 {
956 	char *p, *p1, *res, *resp;
957 	int subst_len, kw_len, subst_count, old_len, new_len;
958 
959 	kw_len = strlen(kw);
960 
961 	/*
962 	 * First, count the number of the keyword occurrences, to
963 	 * preallocate the final string.
964 	 */
965 	for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) {
966 		p1 = strstr(p, kw);
967 		if (p1 == NULL)
968 			break;
969 	}
970 
971 	/*
972 	 * If the keyword is not found, just return.
973 	 *
974 	 * Return non-substituted string if resolution failed.  We
975 	 * cannot do anything more reasonable, the failure mode of the
976 	 * caller is unresolved library anyway.
977 	 */
978 	if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj)))
979 		return (may_free ? real : xstrdup(real));
980 	if (obj != NULL)
981 		subst = obj->origin_path;
982 
983 	/*
984 	 * There is indeed something to substitute.  Calculate the
985 	 * length of the resulting string, and allocate it.
986 	 */
987 	subst_len = strlen(subst);
988 	old_len = strlen(real);
989 	new_len = old_len + (subst_len - kw_len) * subst_count;
990 	res = xmalloc(new_len + 1);
991 
992 	/*
993 	 * Now, execute the substitution loop.
994 	 */
995 	for (p = real, resp = res, *resp = '\0';;) {
996 		p1 = strstr(p, kw);
997 		if (p1 != NULL) {
998 			/* Copy the prefix before keyword. */
999 			memcpy(resp, p, p1 - p);
1000 			resp += p1 - p;
1001 			/* Keyword replacement. */
1002 			memcpy(resp, subst, subst_len);
1003 			resp += subst_len;
1004 			*resp = '\0';
1005 			p = p1 + kw_len;
1006 		} else
1007 			break;
1008 	}
1009 
1010 	/* Copy to the end of string and finish. */
1011 	strcat(resp, p);
1012 	if (may_free)
1013 		free(real);
1014 	return (res);
1015 }
1016 
1017 static char *
1018 origin_subst(Obj_Entry *obj, const char *real)
1019 {
1020 	char *res1, *res2, *res3, *res4;
1021 
1022 	if (obj == NULL || !trust)
1023 		return (xstrdup(real));
1024 	if (uts.sysname[0] == '\0') {
1025 		if (uname(&uts) != 0) {
1026 			_rtld_error("utsname failed: %d", errno);
1027 			return (NULL);
1028 		}
1029 	}
1030 	/* __DECONST is safe here since without may_free real is unchanged */
1031 	res1 = origin_subst_one(obj, __DECONST(char *, real), "$ORIGIN", NULL,
1032 	    false);
1033 	res2 = origin_subst_one(NULL, res1, "$OSNAME", uts.sysname, true);
1034 	res3 = origin_subst_one(NULL, res2, "$OSREL", uts.release, true);
1035 	res4 = origin_subst_one(NULL, res3, "$PLATFORM", uts.machine, true);
1036 	return (res4);
1037 }
1038 
1039 void
1040 rtld_die(void)
1041 {
1042     const char *msg = dlerror();
1043 
1044     if (msg == NULL)
1045 	msg = "Fatal error";
1046     rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": ");
1047     rtld_fdputstr(STDERR_FILENO, msg);
1048     rtld_fdputchar(STDERR_FILENO, '\n');
1049     _exit(1);
1050 }
1051 
1052 /*
1053  * Process a shared object's DYNAMIC section, and save the important
1054  * information in its Obj_Entry structure.
1055  */
1056 static void
1057 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
1058     const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath)
1059 {
1060     const Elf_Dyn *dynp;
1061     Needed_Entry **needed_tail = &obj->needed;
1062     Needed_Entry **needed_filtees_tail = &obj->needed_filtees;
1063     Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees;
1064     const Elf_Hashelt *hashtab;
1065     const Elf32_Word *hashval;
1066     Elf32_Word bkt, nmaskwords;
1067     int bloom_size32;
1068     int plttype = DT_REL;
1069 
1070     *dyn_rpath = NULL;
1071     *dyn_soname = NULL;
1072     *dyn_runpath = NULL;
1073 
1074     obj->bind_now = false;
1075     for (dynp = obj->dynamic;  dynp->d_tag != DT_NULL;  dynp++) {
1076 	switch (dynp->d_tag) {
1077 
1078 	case DT_REL:
1079 	    obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr);
1080 	    break;
1081 
1082 	case DT_RELSZ:
1083 	    obj->relsize = dynp->d_un.d_val;
1084 	    break;
1085 
1086 	case DT_RELENT:
1087 	    assert(dynp->d_un.d_val == sizeof(Elf_Rel));
1088 	    break;
1089 
1090 	case DT_JMPREL:
1091 	    obj->pltrel = (const Elf_Rel *)
1092 	      (obj->relocbase + dynp->d_un.d_ptr);
1093 	    break;
1094 
1095 	case DT_PLTRELSZ:
1096 	    obj->pltrelsize = dynp->d_un.d_val;
1097 	    break;
1098 
1099 	case DT_RELA:
1100 	    obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr);
1101 	    break;
1102 
1103 	case DT_RELASZ:
1104 	    obj->relasize = dynp->d_un.d_val;
1105 	    break;
1106 
1107 	case DT_RELAENT:
1108 	    assert(dynp->d_un.d_val == sizeof(Elf_Rela));
1109 	    break;
1110 
1111 	case DT_PLTREL:
1112 	    plttype = dynp->d_un.d_val;
1113 	    assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
1114 	    break;
1115 
1116 	case DT_SYMTAB:
1117 	    obj->symtab = (const Elf_Sym *)
1118 	      (obj->relocbase + dynp->d_un.d_ptr);
1119 	    break;
1120 
1121 	case DT_SYMENT:
1122 	    assert(dynp->d_un.d_val == sizeof(Elf_Sym));
1123 	    break;
1124 
1125 	case DT_STRTAB:
1126 	    obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr);
1127 	    break;
1128 
1129 	case DT_STRSZ:
1130 	    obj->strsize = dynp->d_un.d_val;
1131 	    break;
1132 
1133 	case DT_VERNEED:
1134 	    obj->verneed = (const Elf_Verneed *)(obj->relocbase +
1135 		dynp->d_un.d_val);
1136 	    break;
1137 
1138 	case DT_VERNEEDNUM:
1139 	    obj->verneednum = dynp->d_un.d_val;
1140 	    break;
1141 
1142 	case DT_VERDEF:
1143 	    obj->verdef = (const Elf_Verdef *)(obj->relocbase +
1144 		dynp->d_un.d_val);
1145 	    break;
1146 
1147 	case DT_VERDEFNUM:
1148 	    obj->verdefnum = dynp->d_un.d_val;
1149 	    break;
1150 
1151 	case DT_VERSYM:
1152 	    obj->versyms = (const Elf_Versym *)(obj->relocbase +
1153 		dynp->d_un.d_val);
1154 	    break;
1155 
1156 	case DT_HASH:
1157 	    {
1158 		hashtab = (const Elf_Hashelt *)(obj->relocbase +
1159 		    dynp->d_un.d_ptr);
1160 		obj->nbuckets = hashtab[0];
1161 		obj->nchains = hashtab[1];
1162 		obj->buckets = hashtab + 2;
1163 		obj->chains = obj->buckets + obj->nbuckets;
1164 		obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 &&
1165 		  obj->buckets != NULL;
1166 	    }
1167 	    break;
1168 
1169 	case DT_GNU_HASH:
1170 	    {
1171 		hashtab = (const Elf_Hashelt *)(obj->relocbase +
1172 		    dynp->d_un.d_ptr);
1173 		obj->nbuckets_gnu = hashtab[0];
1174 		obj->symndx_gnu = hashtab[1];
1175 		nmaskwords = hashtab[2];
1176 		bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords;
1177 		obj->maskwords_bm_gnu = nmaskwords - 1;
1178 		obj->shift2_gnu = hashtab[3];
1179 		obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4);
1180 		obj->buckets_gnu = hashtab + 4 + bloom_size32;
1181 		obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu -
1182 		  obj->symndx_gnu;
1183 		/* Number of bitmask words is required to be power of 2 */
1184 		obj->valid_hash_gnu = powerof2(nmaskwords) &&
1185 		    obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL;
1186 	    }
1187 	    break;
1188 
1189 	case DT_NEEDED:
1190 	    if (!obj->rtld) {
1191 		Needed_Entry *nep = NEW(Needed_Entry);
1192 		nep->name = dynp->d_un.d_val;
1193 		nep->obj = NULL;
1194 		nep->next = NULL;
1195 
1196 		*needed_tail = nep;
1197 		needed_tail = &nep->next;
1198 	    }
1199 	    break;
1200 
1201 	case DT_FILTER:
1202 	    if (!obj->rtld) {
1203 		Needed_Entry *nep = NEW(Needed_Entry);
1204 		nep->name = dynp->d_un.d_val;
1205 		nep->obj = NULL;
1206 		nep->next = NULL;
1207 
1208 		*needed_filtees_tail = nep;
1209 		needed_filtees_tail = &nep->next;
1210 	    }
1211 	    break;
1212 
1213 	case DT_AUXILIARY:
1214 	    if (!obj->rtld) {
1215 		Needed_Entry *nep = NEW(Needed_Entry);
1216 		nep->name = dynp->d_un.d_val;
1217 		nep->obj = NULL;
1218 		nep->next = NULL;
1219 
1220 		*needed_aux_filtees_tail = nep;
1221 		needed_aux_filtees_tail = &nep->next;
1222 	    }
1223 	    break;
1224 
1225 	case DT_PLTGOT:
1226 	    obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr);
1227 	    break;
1228 
1229 	case DT_TEXTREL:
1230 	    obj->textrel = true;
1231 	    break;
1232 
1233 	case DT_SYMBOLIC:
1234 	    obj->symbolic = true;
1235 	    break;
1236 
1237 	case DT_RPATH:
1238 	    /*
1239 	     * We have to wait until later to process this, because we
1240 	     * might not have gotten the address of the string table yet.
1241 	     */
1242 	    *dyn_rpath = dynp;
1243 	    break;
1244 
1245 	case DT_SONAME:
1246 	    *dyn_soname = dynp;
1247 	    break;
1248 
1249 	case DT_RUNPATH:
1250 	    *dyn_runpath = dynp;
1251 	    break;
1252 
1253 	case DT_INIT:
1254 	    obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1255 	    break;
1256 
1257 	case DT_PREINIT_ARRAY:
1258 	    obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1259 	    break;
1260 
1261 	case DT_PREINIT_ARRAYSZ:
1262 	    obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1263 	    break;
1264 
1265 	case DT_INIT_ARRAY:
1266 	    obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1267 	    break;
1268 
1269 	case DT_INIT_ARRAYSZ:
1270 	    obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1271 	    break;
1272 
1273 	case DT_FINI:
1274 	    obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1275 	    break;
1276 
1277 	case DT_FINI_ARRAY:
1278 	    obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1279 	    break;
1280 
1281 	case DT_FINI_ARRAYSZ:
1282 	    obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1283 	    break;
1284 
1285 	/*
1286 	 * Don't process DT_DEBUG on MIPS as the dynamic section
1287 	 * is mapped read-only. DT_MIPS_RLD_MAP is used instead.
1288 	 */
1289 
1290 #ifndef __mips__
1291 	case DT_DEBUG:
1292 	    if (!early)
1293 		dbg("Filling in DT_DEBUG entry");
1294 	    (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug;
1295 	    break;
1296 #endif
1297 
1298 	case DT_FLAGS:
1299 		if (dynp->d_un.d_val & DF_ORIGIN)
1300 		    obj->z_origin = true;
1301 		if (dynp->d_un.d_val & DF_SYMBOLIC)
1302 		    obj->symbolic = true;
1303 		if (dynp->d_un.d_val & DF_TEXTREL)
1304 		    obj->textrel = true;
1305 		if (dynp->d_un.d_val & DF_BIND_NOW)
1306 		    obj->bind_now = true;
1307 		if (dynp->d_un.d_val & DF_STATIC_TLS)
1308 		    obj->static_tls = true;
1309 	    break;
1310 #ifdef __mips__
1311 	case DT_MIPS_LOCAL_GOTNO:
1312 		obj->local_gotno = dynp->d_un.d_val;
1313 		break;
1314 
1315 	case DT_MIPS_SYMTABNO:
1316 		obj->symtabno = dynp->d_un.d_val;
1317 		break;
1318 
1319 	case DT_MIPS_GOTSYM:
1320 		obj->gotsym = dynp->d_un.d_val;
1321 		break;
1322 
1323 	case DT_MIPS_RLD_MAP:
1324 		*((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug;
1325 		break;
1326 
1327 	case DT_MIPS_RLD_MAP_REL:
1328 		// The MIPS_RLD_MAP_REL tag stores the offset to the .rld_map
1329 		// section relative to the address of the tag itself.
1330 		*((Elf_Addr *)(__DECONST(char*, dynp) + dynp->d_un.d_val)) =
1331 		    (Elf_Addr) &r_debug;
1332 		break;
1333 
1334 	case DT_MIPS_PLTGOT:
1335 		obj->mips_pltgot = (Elf_Addr *)(obj->relocbase +
1336 		    dynp->d_un.d_ptr);
1337 		break;
1338 
1339 #endif
1340 
1341 #ifdef __powerpc__
1342 #ifdef __powerpc64__
1343 	case DT_PPC64_GLINK:
1344 		obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1345 		break;
1346 #else
1347 	case DT_PPC_GOT:
1348 		obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr);
1349 		break;
1350 #endif
1351 #endif
1352 
1353 	case DT_FLAGS_1:
1354 		if (dynp->d_un.d_val & DF_1_NOOPEN)
1355 		    obj->z_noopen = true;
1356 		if (dynp->d_un.d_val & DF_1_ORIGIN)
1357 		    obj->z_origin = true;
1358 		if (dynp->d_un.d_val & DF_1_GLOBAL)
1359 		    obj->z_global = true;
1360 		if (dynp->d_un.d_val & DF_1_BIND_NOW)
1361 		    obj->bind_now = true;
1362 		if (dynp->d_un.d_val & DF_1_NODELETE)
1363 		    obj->z_nodelete = true;
1364 		if (dynp->d_un.d_val & DF_1_LOADFLTR)
1365 		    obj->z_loadfltr = true;
1366 		if (dynp->d_un.d_val & DF_1_INTERPOSE)
1367 		    obj->z_interpose = true;
1368 		if (dynp->d_un.d_val & DF_1_NODEFLIB)
1369 		    obj->z_nodeflib = true;
1370 	    break;
1371 
1372 	default:
1373 	    if (!early) {
1374 		dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
1375 		    (long)dynp->d_tag);
1376 	    }
1377 	    break;
1378 	}
1379     }
1380 
1381     obj->traced = false;
1382 
1383     if (plttype == DT_RELA) {
1384 	obj->pltrela = (const Elf_Rela *) obj->pltrel;
1385 	obj->pltrel = NULL;
1386 	obj->pltrelasize = obj->pltrelsize;
1387 	obj->pltrelsize = 0;
1388     }
1389 
1390     /* Determine size of dynsym table (equal to nchains of sysv hash) */
1391     if (obj->valid_hash_sysv)
1392 	obj->dynsymcount = obj->nchains;
1393     else if (obj->valid_hash_gnu) {
1394 	obj->dynsymcount = 0;
1395 	for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) {
1396 	    if (obj->buckets_gnu[bkt] == 0)
1397 		continue;
1398 	    hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]];
1399 	    do
1400 		obj->dynsymcount++;
1401 	    while ((*hashval++ & 1u) == 0);
1402 	}
1403 	obj->dynsymcount += obj->symndx_gnu;
1404     }
1405 }
1406 
1407 static bool
1408 obj_resolve_origin(Obj_Entry *obj)
1409 {
1410 
1411 	if (obj->origin_path != NULL)
1412 		return (true);
1413 	obj->origin_path = xmalloc(PATH_MAX);
1414 	return (rtld_dirname_abs(obj->path, obj->origin_path) != -1);
1415 }
1416 
1417 static bool
1418 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
1419     const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath)
1420 {
1421 
1422 	if (obj->z_origin && !obj_resolve_origin(obj))
1423 		return (false);
1424 
1425 	if (dyn_runpath != NULL) {
1426 		obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val;
1427 		obj->runpath = origin_subst(obj, obj->runpath);
1428 	} else if (dyn_rpath != NULL) {
1429 		obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val;
1430 		obj->rpath = origin_subst(obj, obj->rpath);
1431 	}
1432 	if (dyn_soname != NULL)
1433 		object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
1434 	return (true);
1435 }
1436 
1437 static bool
1438 digest_dynamic(Obj_Entry *obj, int early)
1439 {
1440 	const Elf_Dyn *dyn_rpath;
1441 	const Elf_Dyn *dyn_soname;
1442 	const Elf_Dyn *dyn_runpath;
1443 
1444 	digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath);
1445 	return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath));
1446 }
1447 
1448 /*
1449  * Process a shared object's program header.  This is used only for the
1450  * main program, when the kernel has already loaded the main program
1451  * into memory before calling the dynamic linker.  It creates and
1452  * returns an Obj_Entry structure.
1453  */
1454 static Obj_Entry *
1455 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
1456 {
1457     Obj_Entry *obj;
1458     const Elf_Phdr *phlimit = phdr + phnum;
1459     const Elf_Phdr *ph;
1460     Elf_Addr note_start, note_end;
1461     int nsegs = 0;
1462 
1463     obj = obj_new();
1464     for (ph = phdr;  ph < phlimit;  ph++) {
1465 	if (ph->p_type != PT_PHDR)
1466 	    continue;
1467 
1468 	obj->phdr = phdr;
1469 	obj->phsize = ph->p_memsz;
1470 	obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr;
1471 	break;
1472     }
1473 
1474     obj->stack_flags = PF_X | PF_R | PF_W;
1475 
1476     for (ph = phdr;  ph < phlimit;  ph++) {
1477 	switch (ph->p_type) {
1478 
1479 	case PT_INTERP:
1480 	    obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
1481 	    break;
1482 
1483 	case PT_LOAD:
1484 	    if (nsegs == 0) {	/* First load segment */
1485 		obj->vaddrbase = trunc_page(ph->p_vaddr);
1486 		obj->mapbase = obj->vaddrbase + obj->relocbase;
1487 	    } else {		/* Last load segment */
1488 		obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1489 		  obj->vaddrbase;
1490 	    }
1491 	    nsegs++;
1492 	    break;
1493 
1494 	case PT_DYNAMIC:
1495 	    obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
1496 	    break;
1497 
1498 	case PT_TLS:
1499 	    obj->tlsindex = 1;
1500 	    obj->tlssize = ph->p_memsz;
1501 	    obj->tlsalign = ph->p_align;
1502 	    obj->tlsinitsize = ph->p_filesz;
1503 	    obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
1504 	    break;
1505 
1506 	case PT_GNU_STACK:
1507 	    obj->stack_flags = ph->p_flags;
1508 	    break;
1509 
1510 	case PT_GNU_RELRO:
1511 	    obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
1512 	    obj->relro_size = round_page(ph->p_memsz);
1513 	    break;
1514 
1515 	case PT_NOTE:
1516 	    note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr;
1517 	    note_end = note_start + ph->p_filesz;
1518 	    digest_notes(obj, note_start, note_end);
1519 	    break;
1520 	}
1521     }
1522     if (nsegs < 1) {
1523 	_rtld_error("%s: too few PT_LOAD segments", path);
1524 	return NULL;
1525     }
1526 
1527     obj->entry = entry;
1528     return obj;
1529 }
1530 
1531 void
1532 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end)
1533 {
1534 	const Elf_Note *note;
1535 	const char *note_name;
1536 	uintptr_t p;
1537 
1538 	for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end;
1539 	    note = (const Elf_Note *)((const char *)(note + 1) +
1540 	      roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
1541 	      roundup2(note->n_descsz, sizeof(Elf32_Addr)))) {
1542 		if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) ||
1543 		    note->n_descsz != sizeof(int32_t))
1544 			continue;
1545 		if (note->n_type != NT_FREEBSD_ABI_TAG &&
1546 		    note->n_type != NT_FREEBSD_FEATURE_CTL &&
1547 		    note->n_type != NT_FREEBSD_NOINIT_TAG)
1548 			continue;
1549 		note_name = (const char *)(note + 1);
1550 		if (strncmp(NOTE_FREEBSD_VENDOR, note_name,
1551 		    sizeof(NOTE_FREEBSD_VENDOR)) != 0)
1552 			continue;
1553 		switch (note->n_type) {
1554 		case NT_FREEBSD_ABI_TAG:
1555 			/* FreeBSD osrel note */
1556 			p = (uintptr_t)(note + 1);
1557 			p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1558 			obj->osrel = *(const int32_t *)(p);
1559 			dbg("note osrel %d", obj->osrel);
1560 			break;
1561 		case NT_FREEBSD_FEATURE_CTL:
1562 			/* FreeBSD ABI feature control note */
1563 			p = (uintptr_t)(note + 1);
1564 			p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1565 			obj->fctl0 = *(const uint32_t *)(p);
1566 			dbg("note fctl0 %#x", obj->fctl0);
1567 			break;
1568 		case NT_FREEBSD_NOINIT_TAG:
1569 			/* FreeBSD 'crt does not call init' note */
1570 			obj->crt_no_init = true;
1571 			dbg("note crt_no_init");
1572 			break;
1573 		}
1574 	}
1575 }
1576 
1577 static Obj_Entry *
1578 dlcheck(void *handle)
1579 {
1580     Obj_Entry *obj;
1581 
1582     TAILQ_FOREACH(obj, &obj_list, next) {
1583 	if (obj == (Obj_Entry *) handle)
1584 	    break;
1585     }
1586 
1587     if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1588 	_rtld_error("Invalid shared object handle %p", handle);
1589 	return NULL;
1590     }
1591     return obj;
1592 }
1593 
1594 /*
1595  * If the given object is already in the donelist, return true.  Otherwise
1596  * add the object to the list and return false.
1597  */
1598 static bool
1599 donelist_check(DoneList *dlp, const Obj_Entry *obj)
1600 {
1601     unsigned int i;
1602 
1603     for (i = 0;  i < dlp->num_used;  i++)
1604 	if (dlp->objs[i] == obj)
1605 	    return true;
1606     /*
1607      * Our donelist allocation should always be sufficient.  But if
1608      * our threads locking isn't working properly, more shared objects
1609      * could have been loaded since we allocated the list.  That should
1610      * never happen, but we'll handle it properly just in case it does.
1611      */
1612     if (dlp->num_used < dlp->num_alloc)
1613 	dlp->objs[dlp->num_used++] = obj;
1614     return false;
1615 }
1616 
1617 /*
1618  * Hash function for symbol table lookup.  Don't even think about changing
1619  * this.  It is specified by the System V ABI.
1620  */
1621 unsigned long
1622 elf_hash(const char *name)
1623 {
1624     const unsigned char *p = (const unsigned char *) name;
1625     unsigned long h = 0;
1626     unsigned long g;
1627 
1628     while (*p != '\0') {
1629 	h = (h << 4) + *p++;
1630 	if ((g = h & 0xf0000000) != 0)
1631 	    h ^= g >> 24;
1632 	h &= ~g;
1633     }
1634     return h;
1635 }
1636 
1637 /*
1638  * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits
1639  * unsigned in case it's implemented with a wider type.
1640  */
1641 static uint32_t
1642 gnu_hash(const char *s)
1643 {
1644 	uint32_t h;
1645 	unsigned char c;
1646 
1647 	h = 5381;
1648 	for (c = *s; c != '\0'; c = *++s)
1649 		h = h * 33 + c;
1650 	return (h & 0xffffffff);
1651 }
1652 
1653 
1654 /*
1655  * Find the library with the given name, and return its full pathname.
1656  * The returned string is dynamically allocated.  Generates an error
1657  * message and returns NULL if the library cannot be found.
1658  *
1659  * If the second argument is non-NULL, then it refers to an already-
1660  * loaded shared object, whose library search path will be searched.
1661  *
1662  * If a library is successfully located via LD_LIBRARY_PATH_FDS, its
1663  * descriptor (which is close-on-exec) will be passed out via the third
1664  * argument.
1665  *
1666  * The search order is:
1667  *   DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1)
1668  *   DT_RPATH of the main object if DSO without defined DT_RUNPATH (1)
1669  *   LD_LIBRARY_PATH
1670  *   DT_RUNPATH in the referencing file
1671  *   ldconfig hints (if -z nodefaultlib, filter out default library directories
1672  *	 from list)
1673  *   /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib
1674  *
1675  * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined.
1676  */
1677 static char *
1678 find_library(const char *xname, const Obj_Entry *refobj, int *fdp)
1679 {
1680 	char *pathname, *refobj_path;
1681 	const char *name;
1682 	bool nodeflib, objgiven;
1683 
1684 	objgiven = refobj != NULL;
1685 
1686 	if (libmap_disable || !objgiven ||
1687 	    (name = lm_find(refobj->path, xname)) == NULL)
1688 		name = xname;
1689 
1690 	if (strchr(name, '/') != NULL) {	/* Hard coded pathname */
1691 		if (name[0] != '/' && !trust) {
1692 			_rtld_error("Absolute pathname required "
1693 			    "for shared object \"%s\"", name);
1694 			return (NULL);
1695 		}
1696 		return (origin_subst(__DECONST(Obj_Entry *, refobj),
1697 		    __DECONST(char *, name)));
1698 	}
1699 
1700 	dbg(" Searching for \"%s\"", name);
1701 	refobj_path = objgiven ? refobj->path : NULL;
1702 
1703 	/*
1704 	 * If refobj->rpath != NULL, then refobj->runpath is NULL.  Fall
1705 	 * back to pre-conforming behaviour if user requested so with
1706 	 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z
1707 	 * nodeflib.
1708 	 */
1709 	if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) {
1710 		pathname = search_library_path(name, ld_library_path,
1711 		    refobj_path, fdp);
1712 		if (pathname != NULL)
1713 			return (pathname);
1714 		if (refobj != NULL) {
1715 			pathname = search_library_path(name, refobj->rpath,
1716 			    refobj_path, fdp);
1717 			if (pathname != NULL)
1718 				return (pathname);
1719 		}
1720 		pathname = search_library_pathfds(name, ld_library_dirs, fdp);
1721 		if (pathname != NULL)
1722 			return (pathname);
1723 		pathname = search_library_path(name, gethints(false),
1724 		    refobj_path, fdp);
1725 		if (pathname != NULL)
1726 			return (pathname);
1727 		pathname = search_library_path(name, ld_standard_library_path,
1728 		    refobj_path, fdp);
1729 		if (pathname != NULL)
1730 			return (pathname);
1731 	} else {
1732 		nodeflib = objgiven ? refobj->z_nodeflib : false;
1733 		if (objgiven) {
1734 			pathname = search_library_path(name, refobj->rpath,
1735 			    refobj->path, fdp);
1736 			if (pathname != NULL)
1737 				return (pathname);
1738 		}
1739 		if (objgiven && refobj->runpath == NULL && refobj != obj_main) {
1740 			pathname = search_library_path(name, obj_main->rpath,
1741 			    refobj_path, fdp);
1742 			if (pathname != NULL)
1743 				return (pathname);
1744 		}
1745 		pathname = search_library_path(name, ld_library_path,
1746 		    refobj_path, fdp);
1747 		if (pathname != NULL)
1748 			return (pathname);
1749 		if (objgiven) {
1750 			pathname = search_library_path(name, refobj->runpath,
1751 			    refobj_path, fdp);
1752 			if (pathname != NULL)
1753 				return (pathname);
1754 		}
1755 		pathname = search_library_pathfds(name, ld_library_dirs, fdp);
1756 		if (pathname != NULL)
1757 			return (pathname);
1758 		pathname = search_library_path(name, gethints(nodeflib),
1759 		    refobj_path, fdp);
1760 		if (pathname != NULL)
1761 			return (pathname);
1762 		if (objgiven && !nodeflib) {
1763 			pathname = search_library_path(name,
1764 			    ld_standard_library_path, refobj_path, fdp);
1765 			if (pathname != NULL)
1766 				return (pathname);
1767 		}
1768 	}
1769 
1770 	if (objgiven && refobj->path != NULL) {
1771 		_rtld_error("Shared object \"%s\" not found, "
1772 		    "required by \"%s\"", name, basename(refobj->path));
1773 	} else {
1774 		_rtld_error("Shared object \"%s\" not found", name);
1775 	}
1776 	return (NULL);
1777 }
1778 
1779 /*
1780  * Given a symbol number in a referencing object, find the corresponding
1781  * definition of the symbol.  Returns a pointer to the symbol, or NULL if
1782  * no definition was found.  Returns a pointer to the Obj_Entry of the
1783  * defining object via the reference parameter DEFOBJ_OUT.
1784  */
1785 const Elf_Sym *
1786 find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1787     const Obj_Entry **defobj_out, int flags, SymCache *cache,
1788     RtldLockState *lockstate)
1789 {
1790     const Elf_Sym *ref;
1791     const Elf_Sym *def;
1792     const Obj_Entry *defobj;
1793     const Ver_Entry *ve;
1794     SymLook req;
1795     const char *name;
1796     int res;
1797 
1798     /*
1799      * If we have already found this symbol, get the information from
1800      * the cache.
1801      */
1802     if (symnum >= refobj->dynsymcount)
1803 	return NULL;	/* Bad object */
1804     if (cache != NULL && cache[symnum].sym != NULL) {
1805 	*defobj_out = cache[symnum].obj;
1806 	return cache[symnum].sym;
1807     }
1808 
1809     ref = refobj->symtab + symnum;
1810     name = refobj->strtab + ref->st_name;
1811     def = NULL;
1812     defobj = NULL;
1813     ve = NULL;
1814 
1815     /*
1816      * We don't have to do a full scale lookup if the symbol is local.
1817      * We know it will bind to the instance in this load module; to
1818      * which we already have a pointer (ie ref). By not doing a lookup,
1819      * we not only improve performance, but it also avoids unresolvable
1820      * symbols when local symbols are not in the hash table. This has
1821      * been seen with the ia64 toolchain.
1822      */
1823     if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1824 	if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
1825 	    _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1826 		symnum);
1827 	}
1828 	symlook_init(&req, name);
1829 	req.flags = flags;
1830 	ve = req.ventry = fetch_ventry(refobj, symnum);
1831 	req.lockstate = lockstate;
1832 	res = symlook_default(&req, refobj);
1833 	if (res == 0) {
1834 	    def = req.sym_out;
1835 	    defobj = req.defobj_out;
1836 	}
1837     } else {
1838 	def = ref;
1839 	defobj = refobj;
1840     }
1841 
1842     /*
1843      * If we found no definition and the reference is weak, treat the
1844      * symbol as having the value zero.
1845      */
1846     if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1847 	def = &sym_zero;
1848 	defobj = obj_main;
1849     }
1850 
1851     if (def != NULL) {
1852 	*defobj_out = defobj;
1853 	/* Record the information in the cache to avoid subsequent lookups. */
1854 	if (cache != NULL) {
1855 	    cache[symnum].sym = def;
1856 	    cache[symnum].obj = defobj;
1857 	}
1858     } else {
1859 	if (refobj != &obj_rtld)
1860 	    _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name,
1861 	      ve != NULL ? "@" : "", ve != NULL ? ve->name : "");
1862     }
1863     return def;
1864 }
1865 
1866 /*
1867  * Return the search path from the ldconfig hints file, reading it if
1868  * necessary.  If nostdlib is true, then the default search paths are
1869  * not added to result.
1870  *
1871  * Returns NULL if there are problems with the hints file,
1872  * or if the search path there is empty.
1873  */
1874 static const char *
1875 gethints(bool nostdlib)
1876 {
1877 	static char *filtered_path;
1878 	static const char *hints;
1879 	static struct elfhints_hdr hdr;
1880 	struct fill_search_info_args sargs, hargs;
1881 	struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo;
1882 	struct dl_serpath *SLPpath, *hintpath;
1883 	char *p;
1884 	struct stat hint_stat;
1885 	unsigned int SLPndx, hintndx, fndx, fcount;
1886 	int fd;
1887 	size_t flen;
1888 	uint32_t dl;
1889 	bool skip;
1890 
1891 	/* First call, read the hints file */
1892 	if (hints == NULL) {
1893 		/* Keep from trying again in case the hints file is bad. */
1894 		hints = "";
1895 
1896 		if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1)
1897 			return (NULL);
1898 
1899 		/*
1900 		 * Check of hdr.dirlistlen value against type limit
1901 		 * intends to pacify static analyzers.  Further
1902 		 * paranoia leads to checks that dirlist is fully
1903 		 * contained in the file range.
1904 		 */
1905 		if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1906 		    hdr.magic != ELFHINTS_MAGIC ||
1907 		    hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 ||
1908 		    fstat(fd, &hint_stat) == -1) {
1909 cleanup1:
1910 			close(fd);
1911 			hdr.dirlistlen = 0;
1912 			return (NULL);
1913 		}
1914 		dl = hdr.strtab;
1915 		if (dl + hdr.dirlist < dl)
1916 			goto cleanup1;
1917 		dl += hdr.dirlist;
1918 		if (dl + hdr.dirlistlen < dl)
1919 			goto cleanup1;
1920 		dl += hdr.dirlistlen;
1921 		if (dl > hint_stat.st_size)
1922 			goto cleanup1;
1923 		p = xmalloc(hdr.dirlistlen + 1);
1924 		if (pread(fd, p, hdr.dirlistlen + 1,
1925 		    hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 ||
1926 		    p[hdr.dirlistlen] != '\0') {
1927 			free(p);
1928 			goto cleanup1;
1929 		}
1930 		hints = p;
1931 		close(fd);
1932 	}
1933 
1934 	/*
1935 	 * If caller agreed to receive list which includes the default
1936 	 * paths, we are done. Otherwise, if we still did not
1937 	 * calculated filtered result, do it now.
1938 	 */
1939 	if (!nostdlib)
1940 		return (hints[0] != '\0' ? hints : NULL);
1941 	if (filtered_path != NULL)
1942 		goto filt_ret;
1943 
1944 	/*
1945 	 * Obtain the list of all configured search paths, and the
1946 	 * list of the default paths.
1947 	 *
1948 	 * First estimate the size of the results.
1949 	 */
1950 	smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
1951 	smeta.dls_cnt = 0;
1952 	hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
1953 	hmeta.dls_cnt = 0;
1954 
1955 	sargs.request = RTLD_DI_SERINFOSIZE;
1956 	sargs.serinfo = &smeta;
1957 	hargs.request = RTLD_DI_SERINFOSIZE;
1958 	hargs.serinfo = &hmeta;
1959 
1960 	path_enumerate(ld_standard_library_path, fill_search_info, NULL,
1961 	    &sargs);
1962 	path_enumerate(hints, fill_search_info, NULL, &hargs);
1963 
1964 	SLPinfo = xmalloc(smeta.dls_size);
1965 	hintinfo = xmalloc(hmeta.dls_size);
1966 
1967 	/*
1968 	 * Next fetch both sets of paths.
1969 	 */
1970 	sargs.request = RTLD_DI_SERINFO;
1971 	sargs.serinfo = SLPinfo;
1972 	sargs.serpath = &SLPinfo->dls_serpath[0];
1973 	sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt];
1974 
1975 	hargs.request = RTLD_DI_SERINFO;
1976 	hargs.serinfo = hintinfo;
1977 	hargs.serpath = &hintinfo->dls_serpath[0];
1978 	hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt];
1979 
1980 	path_enumerate(ld_standard_library_path, fill_search_info, NULL,
1981 	    &sargs);
1982 	path_enumerate(hints, fill_search_info, NULL, &hargs);
1983 
1984 	/*
1985 	 * Now calculate the difference between two sets, by excluding
1986 	 * standard paths from the full set.
1987 	 */
1988 	fndx = 0;
1989 	fcount = 0;
1990 	filtered_path = xmalloc(hdr.dirlistlen + 1);
1991 	hintpath = &hintinfo->dls_serpath[0];
1992 	for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) {
1993 		skip = false;
1994 		SLPpath = &SLPinfo->dls_serpath[0];
1995 		/*
1996 		 * Check each standard path against current.
1997 		 */
1998 		for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) {
1999 			/* matched, skip the path */
2000 			if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) {
2001 				skip = true;
2002 				break;
2003 			}
2004 		}
2005 		if (skip)
2006 			continue;
2007 		/*
2008 		 * Not matched against any standard path, add the path
2009 		 * to result. Separate consequtive paths with ':'.
2010 		 */
2011 		if (fcount > 0) {
2012 			filtered_path[fndx] = ':';
2013 			fndx++;
2014 		}
2015 		fcount++;
2016 		flen = strlen(hintpath->dls_name);
2017 		strncpy((filtered_path + fndx),	hintpath->dls_name, flen);
2018 		fndx += flen;
2019 	}
2020 	filtered_path[fndx] = '\0';
2021 
2022 	free(SLPinfo);
2023 	free(hintinfo);
2024 
2025 filt_ret:
2026 	return (filtered_path[0] != '\0' ? filtered_path : NULL);
2027 }
2028 
2029 static void
2030 init_dag(Obj_Entry *root)
2031 {
2032     const Needed_Entry *needed;
2033     const Objlist_Entry *elm;
2034     DoneList donelist;
2035 
2036     if (root->dag_inited)
2037 	return;
2038     donelist_init(&donelist);
2039 
2040     /* Root object belongs to own DAG. */
2041     objlist_push_tail(&root->dldags, root);
2042     objlist_push_tail(&root->dagmembers, root);
2043     donelist_check(&donelist, root);
2044 
2045     /*
2046      * Add dependencies of root object to DAG in breadth order
2047      * by exploiting the fact that each new object get added
2048      * to the tail of the dagmembers list.
2049      */
2050     STAILQ_FOREACH(elm, &root->dagmembers, link) {
2051 	for (needed = elm->obj->needed; needed != NULL; needed = needed->next) {
2052 	    if (needed->obj == NULL || donelist_check(&donelist, needed->obj))
2053 		continue;
2054 	    objlist_push_tail(&needed->obj->dldags, root);
2055 	    objlist_push_tail(&root->dagmembers, needed->obj);
2056 	}
2057     }
2058     root->dag_inited = true;
2059 }
2060 
2061 static void
2062 init_marker(Obj_Entry *marker)
2063 {
2064 
2065 	bzero(marker, sizeof(*marker));
2066 	marker->marker = true;
2067 }
2068 
2069 Obj_Entry *
2070 globallist_curr(const Obj_Entry *obj)
2071 {
2072 
2073 	for (;;) {
2074 		if (obj == NULL)
2075 			return (NULL);
2076 		if (!obj->marker)
2077 			return (__DECONST(Obj_Entry *, obj));
2078 		obj = TAILQ_PREV(obj, obj_entry_q, next);
2079 	}
2080 }
2081 
2082 Obj_Entry *
2083 globallist_next(const Obj_Entry *obj)
2084 {
2085 
2086 	for (;;) {
2087 		obj = TAILQ_NEXT(obj, next);
2088 		if (obj == NULL)
2089 			return (NULL);
2090 		if (!obj->marker)
2091 			return (__DECONST(Obj_Entry *, obj));
2092 	}
2093 }
2094 
2095 /* Prevent the object from being unmapped while the bind lock is dropped. */
2096 static void
2097 hold_object(Obj_Entry *obj)
2098 {
2099 
2100 	obj->holdcount++;
2101 }
2102 
2103 static void
2104 unhold_object(Obj_Entry *obj)
2105 {
2106 
2107 	assert(obj->holdcount > 0);
2108 	if (--obj->holdcount == 0 && obj->unholdfree)
2109 		release_object(obj);
2110 }
2111 
2112 static void
2113 process_z(Obj_Entry *root)
2114 {
2115 	const Objlist_Entry *elm;
2116 	Obj_Entry *obj;
2117 
2118 	/*
2119 	 * Walk over object DAG and process every dependent object
2120 	 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need
2121 	 * to grow their own DAG.
2122 	 *
2123 	 * For DF_1_GLOBAL, DAG is required for symbol lookups in
2124 	 * symlook_global() to work.
2125 	 *
2126 	 * For DF_1_NODELETE, the DAG should have its reference upped.
2127 	 */
2128 	STAILQ_FOREACH(elm, &root->dagmembers, link) {
2129 		obj = elm->obj;
2130 		if (obj == NULL)
2131 			continue;
2132 		if (obj->z_nodelete && !obj->ref_nodel) {
2133 			dbg("obj %s -z nodelete", obj->path);
2134 			init_dag(obj);
2135 			ref_dag(obj);
2136 			obj->ref_nodel = true;
2137 		}
2138 		if (obj->z_global && objlist_find(&list_global, obj) == NULL) {
2139 			dbg("obj %s -z global", obj->path);
2140 			objlist_push_tail(&list_global, obj);
2141 			init_dag(obj);
2142 		}
2143 	}
2144 }
2145 /*
2146  * Initialize the dynamic linker.  The argument is the address at which
2147  * the dynamic linker has been mapped into memory.  The primary task of
2148  * this function is to relocate the dynamic linker.
2149  */
2150 static void
2151 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
2152 {
2153     Obj_Entry objtmp;	/* Temporary rtld object */
2154     const Elf_Ehdr *ehdr;
2155     const Elf_Dyn *dyn_rpath;
2156     const Elf_Dyn *dyn_soname;
2157     const Elf_Dyn *dyn_runpath;
2158 
2159 #ifdef RTLD_INIT_PAGESIZES_EARLY
2160     /* The page size is required by the dynamic memory allocator. */
2161     init_pagesizes(aux_info);
2162 #endif
2163 
2164     /*
2165      * Conjure up an Obj_Entry structure for the dynamic linker.
2166      *
2167      * The "path" member can't be initialized yet because string constants
2168      * cannot yet be accessed. Below we will set it correctly.
2169      */
2170     memset(&objtmp, 0, sizeof(objtmp));
2171     objtmp.path = NULL;
2172     objtmp.rtld = true;
2173     objtmp.mapbase = mapbase;
2174 #ifdef PIC
2175     objtmp.relocbase = mapbase;
2176 #endif
2177 
2178     objtmp.dynamic = rtld_dynamic(&objtmp);
2179     digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath);
2180     assert(objtmp.needed == NULL);
2181 #if !defined(__mips__)
2182     /* MIPS has a bogus DT_TEXTREL. */
2183     assert(!objtmp.textrel);
2184 #endif
2185     /*
2186      * Temporarily put the dynamic linker entry into the object list, so
2187      * that symbols can be found.
2188      */
2189     relocate_objects(&objtmp, true, &objtmp, 0, NULL);
2190 
2191     ehdr = (Elf_Ehdr *)mapbase;
2192     objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff);
2193     objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]);
2194 
2195     /* Initialize the object list. */
2196     TAILQ_INIT(&obj_list);
2197 
2198     /* Now that non-local variables can be accesses, copy out obj_rtld. */
2199     memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
2200 
2201 #ifndef RTLD_INIT_PAGESIZES_EARLY
2202     /* The page size is required by the dynamic memory allocator. */
2203     init_pagesizes(aux_info);
2204 #endif
2205 
2206     if (aux_info[AT_OSRELDATE] != NULL)
2207 	    osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
2208 
2209     digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath);
2210 
2211     /* Replace the path with a dynamically allocated copy. */
2212     obj_rtld.path = xstrdup(ld_path_rtld);
2213 
2214     r_debug.r_brk = r_debug_state;
2215     r_debug.r_state = RT_CONSISTENT;
2216 }
2217 
2218 /*
2219  * Retrieve the array of supported page sizes.  The kernel provides the page
2220  * sizes in increasing order.
2221  */
2222 static void
2223 init_pagesizes(Elf_Auxinfo **aux_info)
2224 {
2225 	static size_t psa[MAXPAGESIZES];
2226 	int mib[2];
2227 	size_t len, size;
2228 
2229 	if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] !=
2230 	    NULL) {
2231 		size = aux_info[AT_PAGESIZESLEN]->a_un.a_val;
2232 		pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr;
2233 	} else {
2234 		len = 2;
2235 		if (sysctlnametomib("hw.pagesizes", mib, &len) == 0)
2236 			size = sizeof(psa);
2237 		else {
2238 			/* As a fallback, retrieve the base page size. */
2239 			size = sizeof(psa[0]);
2240 			if (aux_info[AT_PAGESZ] != NULL) {
2241 				psa[0] = aux_info[AT_PAGESZ]->a_un.a_val;
2242 				goto psa_filled;
2243 			} else {
2244 				mib[0] = CTL_HW;
2245 				mib[1] = HW_PAGESIZE;
2246 				len = 2;
2247 			}
2248 		}
2249 		if (sysctl(mib, len, psa, &size, NULL, 0) == -1) {
2250 			_rtld_error("sysctl for hw.pagesize(s) failed");
2251 			rtld_die();
2252 		}
2253 psa_filled:
2254 		pagesizes = psa;
2255 	}
2256 	npagesizes = size / sizeof(pagesizes[0]);
2257 	/* Discard any invalid entries at the end of the array. */
2258 	while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0)
2259 		npagesizes--;
2260 }
2261 
2262 /*
2263  * Add the init functions from a needed object list (and its recursive
2264  * needed objects) to "list".  This is not used directly; it is a helper
2265  * function for initlist_add_objects().  The write lock must be held
2266  * when this function is called.
2267  */
2268 static void
2269 initlist_add_neededs(Needed_Entry *needed, Objlist *list)
2270 {
2271     /* Recursively process the successor needed objects. */
2272     if (needed->next != NULL)
2273 	initlist_add_neededs(needed->next, list);
2274 
2275     /* Process the current needed object. */
2276     if (needed->obj != NULL)
2277 	initlist_add_objects(needed->obj, needed->obj, list);
2278 }
2279 
2280 /*
2281  * Scan all of the DAGs rooted in the range of objects from "obj" to
2282  * "tail" and add their init functions to "list".  This recurses over
2283  * the DAGs and ensure the proper init ordering such that each object's
2284  * needed libraries are initialized before the object itself.  At the
2285  * same time, this function adds the objects to the global finalization
2286  * list "list_fini" in the opposite order.  The write lock must be
2287  * held when this function is called.
2288  */
2289 static void
2290 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list)
2291 {
2292     Obj_Entry *nobj;
2293 
2294     if (obj->init_scanned || obj->init_done)
2295 	return;
2296     obj->init_scanned = true;
2297 
2298     /* Recursively process the successor objects. */
2299     nobj = globallist_next(obj);
2300     if (nobj != NULL && obj != tail)
2301 	initlist_add_objects(nobj, tail, list);
2302 
2303     /* Recursively process the needed objects. */
2304     if (obj->needed != NULL)
2305 	initlist_add_neededs(obj->needed, list);
2306     if (obj->needed_filtees != NULL)
2307 	initlist_add_neededs(obj->needed_filtees, list);
2308     if (obj->needed_aux_filtees != NULL)
2309 	initlist_add_neededs(obj->needed_aux_filtees, list);
2310 
2311     /* Add the object to the init list. */
2312     objlist_push_tail(list, obj);
2313 
2314     /* Add the object to the global fini list in the reverse order. */
2315     if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL)
2316       && !obj->on_fini_list) {
2317 	objlist_push_head(&list_fini, obj);
2318 	obj->on_fini_list = true;
2319     }
2320 }
2321 
2322 #ifndef FPTR_TARGET
2323 #define FPTR_TARGET(f)	((Elf_Addr) (f))
2324 #endif
2325 
2326 static void
2327 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate)
2328 {
2329     Needed_Entry *needed, *needed1;
2330 
2331     for (needed = n; needed != NULL; needed = needed->next) {
2332 	if (needed->obj != NULL) {
2333 	    dlclose_locked(needed->obj, lockstate);
2334 	    needed->obj = NULL;
2335 	}
2336     }
2337     for (needed = n; needed != NULL; needed = needed1) {
2338 	needed1 = needed->next;
2339 	free(needed);
2340     }
2341 }
2342 
2343 static void
2344 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate)
2345 {
2346 
2347 	free_needed_filtees(obj->needed_filtees, lockstate);
2348 	obj->needed_filtees = NULL;
2349 	free_needed_filtees(obj->needed_aux_filtees, lockstate);
2350 	obj->needed_aux_filtees = NULL;
2351 	obj->filtees_loaded = false;
2352 }
2353 
2354 static void
2355 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags,
2356     RtldLockState *lockstate)
2357 {
2358 
2359     for (; needed != NULL; needed = needed->next) {
2360 	needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj,
2361 	  flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) |
2362 	  RTLD_LOCAL, lockstate);
2363     }
2364 }
2365 
2366 static void
2367 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate)
2368 {
2369 
2370     lock_restart_for_upgrade(lockstate);
2371     if (!obj->filtees_loaded) {
2372 	load_filtee1(obj, obj->needed_filtees, flags, lockstate);
2373 	load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate);
2374 	obj->filtees_loaded = true;
2375     }
2376 }
2377 
2378 static int
2379 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags)
2380 {
2381     Obj_Entry *obj1;
2382 
2383     for (; needed != NULL; needed = needed->next) {
2384 	obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj,
2385 	  flags & ~RTLD_LO_NOLOAD);
2386 	if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0)
2387 	    return (-1);
2388     }
2389     return (0);
2390 }
2391 
2392 /*
2393  * Given a shared object, traverse its list of needed objects, and load
2394  * each of them.  Returns 0 on success.  Generates an error message and
2395  * returns -1 on failure.
2396  */
2397 static int
2398 load_needed_objects(Obj_Entry *first, int flags)
2399 {
2400     Obj_Entry *obj;
2401 
2402     for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) {
2403 	if (obj->marker)
2404 	    continue;
2405 	if (process_needed(obj, obj->needed, flags) == -1)
2406 	    return (-1);
2407     }
2408     return (0);
2409 }
2410 
2411 static int
2412 load_preload_objects(void)
2413 {
2414     char *p = ld_preload;
2415     Obj_Entry *obj;
2416     static const char delim[] = " \t:;";
2417 
2418     if (p == NULL)
2419 	return 0;
2420 
2421     p += strspn(p, delim);
2422     while (*p != '\0') {
2423 	size_t len = strcspn(p, delim);
2424 	char savech;
2425 
2426 	savech = p[len];
2427 	p[len] = '\0';
2428 	obj = load_object(p, -1, NULL, 0);
2429 	if (obj == NULL)
2430 	    return -1;	/* XXX - cleanup */
2431 	obj->z_interpose = true;
2432 	p[len] = savech;
2433 	p += len;
2434 	p += strspn(p, delim);
2435     }
2436     LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
2437     return 0;
2438 }
2439 
2440 static const char *
2441 printable_path(const char *path)
2442 {
2443 
2444 	return (path == NULL ? "<unknown>" : path);
2445 }
2446 
2447 /*
2448  * Load a shared object into memory, if it is not already loaded.  The
2449  * object may be specified by name or by user-supplied file descriptor
2450  * fd_u. In the later case, the fd_u descriptor is not closed, but its
2451  * duplicate is.
2452  *
2453  * Returns a pointer to the Obj_Entry for the object.  Returns NULL
2454  * on failure.
2455  */
2456 static Obj_Entry *
2457 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags)
2458 {
2459     Obj_Entry *obj;
2460     int fd;
2461     struct stat sb;
2462     char *path;
2463 
2464     fd = -1;
2465     if (name != NULL) {
2466 	TAILQ_FOREACH(obj, &obj_list, next) {
2467 	    if (obj->marker || obj->doomed)
2468 		continue;
2469 	    if (object_match_name(obj, name))
2470 		return (obj);
2471 	}
2472 
2473 	path = find_library(name, refobj, &fd);
2474 	if (path == NULL)
2475 	    return (NULL);
2476     } else
2477 	path = NULL;
2478 
2479     if (fd >= 0) {
2480 	/*
2481 	 * search_library_pathfds() opens a fresh file descriptor for the
2482 	 * library, so there is no need to dup().
2483 	 */
2484     } else if (fd_u == -1) {
2485 	/*
2486 	 * If we didn't find a match by pathname, or the name is not
2487 	 * supplied, open the file and check again by device and inode.
2488 	 * This avoids false mismatches caused by multiple links or ".."
2489 	 * in pathnames.
2490 	 *
2491 	 * To avoid a race, we open the file and use fstat() rather than
2492 	 * using stat().
2493 	 */
2494 	if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) {
2495 	    _rtld_error("Cannot open \"%s\"", path);
2496 	    free(path);
2497 	    return (NULL);
2498 	}
2499     } else {
2500 	fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0);
2501 	if (fd == -1) {
2502 	    _rtld_error("Cannot dup fd");
2503 	    free(path);
2504 	    return (NULL);
2505 	}
2506     }
2507     if (fstat(fd, &sb) == -1) {
2508 	_rtld_error("Cannot fstat \"%s\"", printable_path(path));
2509 	close(fd);
2510 	free(path);
2511 	return NULL;
2512     }
2513     TAILQ_FOREACH(obj, &obj_list, next) {
2514 	if (obj->marker || obj->doomed)
2515 	    continue;
2516 	if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
2517 	    break;
2518     }
2519     if (obj != NULL && name != NULL) {
2520 	object_add_name(obj, name);
2521 	free(path);
2522 	close(fd);
2523 	return obj;
2524     }
2525     if (flags & RTLD_LO_NOLOAD) {
2526 	free(path);
2527 	close(fd);
2528 	return (NULL);
2529     }
2530 
2531     /* First use of this object, so we must map it in */
2532     obj = do_load_object(fd, name, path, &sb, flags);
2533     if (obj == NULL)
2534 	free(path);
2535     close(fd);
2536 
2537     return obj;
2538 }
2539 
2540 static Obj_Entry *
2541 do_load_object(int fd, const char *name, char *path, struct stat *sbp,
2542   int flags)
2543 {
2544     Obj_Entry *obj;
2545     struct statfs fs;
2546 
2547     /*
2548      * but first, make sure that environment variables haven't been
2549      * used to circumvent the noexec flag on a filesystem.
2550      */
2551     if (dangerous_ld_env) {
2552 	if (fstatfs(fd, &fs) != 0) {
2553 	    _rtld_error("Cannot fstatfs \"%s\"", printable_path(path));
2554 	    return NULL;
2555 	}
2556 	if (fs.f_flags & MNT_NOEXEC) {
2557 	    _rtld_error("Cannot execute objects on %s", fs.f_mntonname);
2558 	    return NULL;
2559 	}
2560     }
2561     dbg("loading \"%s\"", printable_path(path));
2562     obj = map_object(fd, printable_path(path), sbp);
2563     if (obj == NULL)
2564         return NULL;
2565 
2566     /*
2567      * If DT_SONAME is present in the object, digest_dynamic2 already
2568      * added it to the object names.
2569      */
2570     if (name != NULL)
2571 	object_add_name(obj, name);
2572     obj->path = path;
2573     if (!digest_dynamic(obj, 0))
2574 	goto errp;
2575     dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path,
2576 	obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount);
2577     if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
2578       RTLD_LO_DLOPEN) {
2579 	dbg("refusing to load non-loadable \"%s\"", obj->path);
2580 	_rtld_error("Cannot dlopen non-loadable %s", obj->path);
2581 	goto errp;
2582     }
2583 
2584     obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0;
2585     TAILQ_INSERT_TAIL(&obj_list, obj, next);
2586     obj_count++;
2587     obj_loads++;
2588     linkmap_add(obj);	/* for GDB & dlinfo() */
2589     max_stack_flags |= obj->stack_flags;
2590 
2591     dbg("  %p .. %p: %s", obj->mapbase,
2592          obj->mapbase + obj->mapsize - 1, obj->path);
2593     if (obj->textrel)
2594 	dbg("  WARNING: %s has impure text", obj->path);
2595     LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
2596 	obj->path);
2597 
2598     return (obj);
2599 
2600 errp:
2601     munmap(obj->mapbase, obj->mapsize);
2602     obj_free(obj);
2603     return (NULL);
2604 }
2605 
2606 static Obj_Entry *
2607 obj_from_addr(const void *addr)
2608 {
2609     Obj_Entry *obj;
2610 
2611     TAILQ_FOREACH(obj, &obj_list, next) {
2612 	if (obj->marker)
2613 	    continue;
2614 	if (addr < (void *) obj->mapbase)
2615 	    continue;
2616 	if (addr < (void *)(obj->mapbase + obj->mapsize))
2617 	    return obj;
2618     }
2619     return NULL;
2620 }
2621 
2622 static void
2623 preinit_main(void)
2624 {
2625     Elf_Addr *preinit_addr;
2626     int index;
2627 
2628     preinit_addr = (Elf_Addr *)obj_main->preinit_array;
2629     if (preinit_addr == NULL)
2630 	return;
2631 
2632     for (index = 0; index < obj_main->preinit_array_num; index++) {
2633 	if (preinit_addr[index] != 0 && preinit_addr[index] != 1) {
2634 	    dbg("calling preinit function for %s at %p", obj_main->path,
2635 	      (void *)preinit_addr[index]);
2636 	    LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index],
2637 	      0, 0, obj_main->path);
2638 	    call_init_pointer(obj_main, preinit_addr[index]);
2639 	}
2640     }
2641 }
2642 
2643 /*
2644  * Call the finalization functions for each of the objects in "list"
2645  * belonging to the DAG of "root" and referenced once. If NULL "root"
2646  * is specified, every finalization function will be called regardless
2647  * of the reference count and the list elements won't be freed. All of
2648  * the objects are expected to have non-NULL fini functions.
2649  */
2650 static void
2651 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
2652 {
2653     Objlist_Entry *elm;
2654     char *saved_msg;
2655     Elf_Addr *fini_addr;
2656     int index;
2657 
2658     assert(root == NULL || root->refcount == 1);
2659 
2660     if (root != NULL)
2661 	root->doomed = true;
2662 
2663     /*
2664      * Preserve the current error message since a fini function might
2665      * call into the dynamic linker and overwrite it.
2666      */
2667     saved_msg = errmsg_save();
2668     do {
2669 	STAILQ_FOREACH(elm, list, link) {
2670 	    if (root != NULL && (elm->obj->refcount != 1 ||
2671 	      objlist_find(&root->dagmembers, elm->obj) == NULL))
2672 		continue;
2673 	    /* Remove object from fini list to prevent recursive invocation. */
2674 	    STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2675 	    /* Ensure that new references cannot be acquired. */
2676 	    elm->obj->doomed = true;
2677 
2678 	    hold_object(elm->obj);
2679 	    lock_release(rtld_bind_lock, lockstate);
2680 	    /*
2681 	     * It is legal to have both DT_FINI and DT_FINI_ARRAY defined.
2682 	     * When this happens, DT_FINI_ARRAY is processed first.
2683 	     */
2684 	    fini_addr = (Elf_Addr *)elm->obj->fini_array;
2685 	    if (fini_addr != NULL && elm->obj->fini_array_num > 0) {
2686 		for (index = elm->obj->fini_array_num - 1; index >= 0;
2687 		  index--) {
2688 		    if (fini_addr[index] != 0 && fini_addr[index] != 1) {
2689 			dbg("calling fini function for %s at %p",
2690 			    elm->obj->path, (void *)fini_addr[index]);
2691 			LD_UTRACE(UTRACE_FINI_CALL, elm->obj,
2692 			    (void *)fini_addr[index], 0, 0, elm->obj->path);
2693 			call_initfini_pointer(elm->obj, fini_addr[index]);
2694 		    }
2695 		}
2696 	    }
2697 	    if (elm->obj->fini != (Elf_Addr)NULL) {
2698 		dbg("calling fini function for %s at %p", elm->obj->path,
2699 		    (void *)elm->obj->fini);
2700 		LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini,
2701 		    0, 0, elm->obj->path);
2702 		call_initfini_pointer(elm->obj, elm->obj->fini);
2703 	    }
2704 	    wlock_acquire(rtld_bind_lock, lockstate);
2705 	    unhold_object(elm->obj);
2706 	    /* No need to free anything if process is going down. */
2707 	    if (root != NULL)
2708 	    	free(elm);
2709 	    /*
2710 	     * We must restart the list traversal after every fini call
2711 	     * because a dlclose() call from the fini function or from
2712 	     * another thread might have modified the reference counts.
2713 	     */
2714 	    break;
2715 	}
2716     } while (elm != NULL);
2717     errmsg_restore(saved_msg);
2718 }
2719 
2720 /*
2721  * Call the initialization functions for each of the objects in
2722  * "list".  All of the objects are expected to have non-NULL init
2723  * functions.
2724  */
2725 static void
2726 objlist_call_init(Objlist *list, RtldLockState *lockstate)
2727 {
2728     Objlist_Entry *elm;
2729     Obj_Entry *obj;
2730     char *saved_msg;
2731     Elf_Addr *init_addr;
2732     void (*reg)(void (*)(void));
2733     int index;
2734 
2735     /*
2736      * Clean init_scanned flag so that objects can be rechecked and
2737      * possibly initialized earlier if any of vectors called below
2738      * cause the change by using dlopen.
2739      */
2740     TAILQ_FOREACH(obj, &obj_list, next) {
2741 	if (obj->marker)
2742 	    continue;
2743 	obj->init_scanned = false;
2744     }
2745 
2746     /*
2747      * Preserve the current error message since an init function might
2748      * call into the dynamic linker and overwrite it.
2749      */
2750     saved_msg = errmsg_save();
2751     STAILQ_FOREACH(elm, list, link) {
2752 	if (elm->obj->init_done) /* Initialized early. */
2753 	    continue;
2754 	/*
2755 	 * Race: other thread might try to use this object before current
2756 	 * one completes the initialization. Not much can be done here
2757 	 * without better locking.
2758 	 */
2759 	elm->obj->init_done = true;
2760 	hold_object(elm->obj);
2761 	reg = NULL;
2762 	if (elm->obj == obj_main && obj_main->crt_no_init) {
2763 		reg = (void (*)(void (*)(void)))get_program_var_addr(
2764 		    "__libc_atexit", lockstate);
2765 	}
2766 	lock_release(rtld_bind_lock, lockstate);
2767 	if (reg != NULL) {
2768 		reg(rtld_exit);
2769 		rtld_exit_ptr = rtld_nop_exit;
2770 	}
2771 
2772         /*
2773          * It is legal to have both DT_INIT and DT_INIT_ARRAY defined.
2774          * When this happens, DT_INIT is processed first.
2775          */
2776 	if (elm->obj->init != (Elf_Addr)NULL) {
2777 	    dbg("calling init function for %s at %p", elm->obj->path,
2778 	        (void *)elm->obj->init);
2779 	    LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init,
2780 	        0, 0, elm->obj->path);
2781 	    call_initfini_pointer(elm->obj, elm->obj->init);
2782 	}
2783 	init_addr = (Elf_Addr *)elm->obj->init_array;
2784 	if (init_addr != NULL) {
2785 	    for (index = 0; index < elm->obj->init_array_num; index++) {
2786 		if (init_addr[index] != 0 && init_addr[index] != 1) {
2787 		    dbg("calling init function for %s at %p", elm->obj->path,
2788 			(void *)init_addr[index]);
2789 		    LD_UTRACE(UTRACE_INIT_CALL, elm->obj,
2790 			(void *)init_addr[index], 0, 0, elm->obj->path);
2791 		    call_init_pointer(elm->obj, init_addr[index]);
2792 		}
2793 	    }
2794 	}
2795 	wlock_acquire(rtld_bind_lock, lockstate);
2796 	unhold_object(elm->obj);
2797     }
2798     errmsg_restore(saved_msg);
2799 }
2800 
2801 static void
2802 objlist_clear(Objlist *list)
2803 {
2804     Objlist_Entry *elm;
2805 
2806     while (!STAILQ_EMPTY(list)) {
2807 	elm = STAILQ_FIRST(list);
2808 	STAILQ_REMOVE_HEAD(list, link);
2809 	free(elm);
2810     }
2811 }
2812 
2813 static Objlist_Entry *
2814 objlist_find(Objlist *list, const Obj_Entry *obj)
2815 {
2816     Objlist_Entry *elm;
2817 
2818     STAILQ_FOREACH(elm, list, link)
2819 	if (elm->obj == obj)
2820 	    return elm;
2821     return NULL;
2822 }
2823 
2824 static void
2825 objlist_init(Objlist *list)
2826 {
2827     STAILQ_INIT(list);
2828 }
2829 
2830 static void
2831 objlist_push_head(Objlist *list, Obj_Entry *obj)
2832 {
2833     Objlist_Entry *elm;
2834 
2835     elm = NEW(Objlist_Entry);
2836     elm->obj = obj;
2837     STAILQ_INSERT_HEAD(list, elm, link);
2838 }
2839 
2840 static void
2841 objlist_push_tail(Objlist *list, Obj_Entry *obj)
2842 {
2843     Objlist_Entry *elm;
2844 
2845     elm = NEW(Objlist_Entry);
2846     elm->obj = obj;
2847     STAILQ_INSERT_TAIL(list, elm, link);
2848 }
2849 
2850 static void
2851 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj)
2852 {
2853 	Objlist_Entry *elm, *listelm;
2854 
2855 	STAILQ_FOREACH(listelm, list, link) {
2856 		if (listelm->obj == listobj)
2857 			break;
2858 	}
2859 	elm = NEW(Objlist_Entry);
2860 	elm->obj = obj;
2861 	if (listelm != NULL)
2862 		STAILQ_INSERT_AFTER(list, listelm, elm, link);
2863 	else
2864 		STAILQ_INSERT_TAIL(list, elm, link);
2865 }
2866 
2867 static void
2868 objlist_remove(Objlist *list, Obj_Entry *obj)
2869 {
2870     Objlist_Entry *elm;
2871 
2872     if ((elm = objlist_find(list, obj)) != NULL) {
2873 	STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2874 	free(elm);
2875     }
2876 }
2877 
2878 /*
2879  * Relocate dag rooted in the specified object.
2880  * Returns 0 on success, or -1 on failure.
2881  */
2882 
2883 static int
2884 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj,
2885     int flags, RtldLockState *lockstate)
2886 {
2887 	Objlist_Entry *elm;
2888 	int error;
2889 
2890 	error = 0;
2891 	STAILQ_FOREACH(elm, &root->dagmembers, link) {
2892 		error = relocate_object(elm->obj, bind_now, rtldobj, flags,
2893 		    lockstate);
2894 		if (error == -1)
2895 			break;
2896 	}
2897 	return (error);
2898 }
2899 
2900 /*
2901  * Prepare for, or clean after, relocating an object marked with
2902  * DT_TEXTREL or DF_TEXTREL.  Before relocating, all read-only
2903  * segments are remapped read-write.  After relocations are done, the
2904  * segment's permissions are returned back to the modes specified in
2905  * the phdrs.  If any relocation happened, or always for wired
2906  * program, COW is triggered.
2907  */
2908 static int
2909 reloc_textrel_prot(Obj_Entry *obj, bool before)
2910 {
2911 	const Elf_Phdr *ph;
2912 	void *base;
2913 	size_t l, sz;
2914 	int prot;
2915 
2916 	for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0;
2917 	    l--, ph++) {
2918 		if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0)
2919 			continue;
2920 		base = obj->relocbase + trunc_page(ph->p_vaddr);
2921 		sz = round_page(ph->p_vaddr + ph->p_filesz) -
2922 		    trunc_page(ph->p_vaddr);
2923 		prot = convert_prot(ph->p_flags) | (before ? PROT_WRITE : 0);
2924 		if (mprotect(base, sz, prot) == -1) {
2925 			_rtld_error("%s: Cannot write-%sable text segment: %s",
2926 			    obj->path, before ? "en" : "dis",
2927 			    rtld_strerror(errno));
2928 			return (-1);
2929 		}
2930 	}
2931 	return (0);
2932 }
2933 
2934 /*
2935  * Relocate single object.
2936  * Returns 0 on success, or -1 on failure.
2937  */
2938 static int
2939 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
2940     int flags, RtldLockState *lockstate)
2941 {
2942 
2943 	if (obj->relocated)
2944 		return (0);
2945 	obj->relocated = true;
2946 	if (obj != rtldobj)
2947 		dbg("relocating \"%s\"", obj->path);
2948 
2949 	if (obj->symtab == NULL || obj->strtab == NULL ||
2950 	    !(obj->valid_hash_sysv || obj->valid_hash_gnu)) {
2951 		_rtld_error("%s: Shared object has no run-time symbol table",
2952 			    obj->path);
2953 		return (-1);
2954 	}
2955 
2956 	/* There are relocations to the write-protected text segment. */
2957 	if (obj->textrel && reloc_textrel_prot(obj, true) != 0)
2958 		return (-1);
2959 
2960 	/* Process the non-PLT non-IFUNC relocations. */
2961 	if (reloc_non_plt(obj, rtldobj, flags, lockstate))
2962 		return (-1);
2963 
2964 	/* Re-protected the text segment. */
2965 	if (obj->textrel && reloc_textrel_prot(obj, false) != 0)
2966 		return (-1);
2967 
2968 	/* Set the special PLT or GOT entries. */
2969 	init_pltgot(obj);
2970 
2971 	/* Process the PLT relocations. */
2972 	if (reloc_plt(obj, flags, lockstate) == -1)
2973 		return (-1);
2974 	/* Relocate the jump slots if we are doing immediate binding. */
2975 	if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags,
2976 	    lockstate) == -1)
2977 		return (-1);
2978 
2979 	if (!obj->mainprog && obj_enforce_relro(obj) == -1)
2980 		return (-1);
2981 
2982 	/*
2983 	 * Set up the magic number and version in the Obj_Entry.  These
2984 	 * were checked in the crt1.o from the original ElfKit, so we
2985 	 * set them for backward compatibility.
2986 	 */
2987 	obj->magic = RTLD_MAGIC;
2988 	obj->version = RTLD_VERSION;
2989 
2990 	return (0);
2991 }
2992 
2993 /*
2994  * Relocate newly-loaded shared objects.  The argument is a pointer to
2995  * the Obj_Entry for the first such object.  All objects from the first
2996  * to the end of the list of objects are relocated.  Returns 0 on success,
2997  * or -1 on failure.
2998  */
2999 static int
3000 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
3001     int flags, RtldLockState *lockstate)
3002 {
3003 	Obj_Entry *obj;
3004 	int error;
3005 
3006 	for (error = 0, obj = first;  obj != NULL;
3007 	    obj = TAILQ_NEXT(obj, next)) {
3008 		if (obj->marker)
3009 			continue;
3010 		error = relocate_object(obj, bind_now, rtldobj, flags,
3011 		    lockstate);
3012 		if (error == -1)
3013 			break;
3014 	}
3015 	return (error);
3016 }
3017 
3018 /*
3019  * The handling of R_MACHINE_IRELATIVE relocations and jumpslots
3020  * referencing STT_GNU_IFUNC symbols is postponed till the other
3021  * relocations are done.  The indirect functions specified as
3022  * ifunc are allowed to call other symbols, so we need to have
3023  * objects relocated before asking for resolution from indirects.
3024  *
3025  * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion,
3026  * instead of the usual lazy handling of PLT slots.  It is
3027  * consistent with how GNU does it.
3028  */
3029 static int
3030 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags,
3031     RtldLockState *lockstate)
3032 {
3033 
3034 	if (obj->ifuncs_resolved)
3035 		return (0);
3036 	obj->ifuncs_resolved = true;
3037 	if (!obj->irelative && !obj->irelative_nonplt &&
3038 	    !((obj->bind_now || bind_now) && obj->gnu_ifunc))
3039 		return (0);
3040 	if (obj_disable_relro(obj) == -1 ||
3041 	    (obj->irelative && reloc_iresolve(obj, lockstate) == -1) ||
3042 	    (obj->irelative_nonplt && reloc_iresolve_nonplt(obj,
3043 	    lockstate) == -1) ||
3044 	    ((obj->bind_now || bind_now) && obj->gnu_ifunc &&
3045 	    reloc_gnu_ifunc(obj, flags, lockstate) == -1) ||
3046 	    obj_enforce_relro(obj) == -1)
3047 		return (-1);
3048 	return (0);
3049 }
3050 
3051 static int
3052 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags,
3053     RtldLockState *lockstate)
3054 {
3055 	Objlist_Entry *elm;
3056 	Obj_Entry *obj;
3057 
3058 	STAILQ_FOREACH(elm, list, link) {
3059 		obj = elm->obj;
3060 		if (obj->marker)
3061 			continue;
3062 		if (resolve_object_ifunc(obj, bind_now, flags,
3063 		    lockstate) == -1)
3064 			return (-1);
3065 	}
3066 	return (0);
3067 }
3068 
3069 /*
3070  * Cleanup procedure.  It will be called (by the atexit mechanism) just
3071  * before the process exits.
3072  */
3073 static void
3074 rtld_exit(void)
3075 {
3076     RtldLockState lockstate;
3077 
3078     wlock_acquire(rtld_bind_lock, &lockstate);
3079     dbg("rtld_exit()");
3080     objlist_call_fini(&list_fini, NULL, &lockstate);
3081     /* No need to remove the items from the list, since we are exiting. */
3082     if (!libmap_disable)
3083         lm_fini();
3084     lock_release(rtld_bind_lock, &lockstate);
3085 }
3086 
3087 static void
3088 rtld_nop_exit(void)
3089 {
3090 }
3091 
3092 /*
3093  * Iterate over a search path, translate each element, and invoke the
3094  * callback on the result.
3095  */
3096 static void *
3097 path_enumerate(const char *path, path_enum_proc callback,
3098     const char *refobj_path, void *arg)
3099 {
3100     const char *trans;
3101     if (path == NULL)
3102 	return (NULL);
3103 
3104     path += strspn(path, ":;");
3105     while (*path != '\0') {
3106 	size_t len;
3107 	char  *res;
3108 
3109 	len = strcspn(path, ":;");
3110 	trans = lm_findn(refobj_path, path, len);
3111 	if (trans)
3112 	    res = callback(trans, strlen(trans), arg);
3113 	else
3114 	    res = callback(path, len, arg);
3115 
3116 	if (res != NULL)
3117 	    return (res);
3118 
3119 	path += len;
3120 	path += strspn(path, ":;");
3121     }
3122 
3123     return (NULL);
3124 }
3125 
3126 struct try_library_args {
3127     const char	*name;
3128     size_t	 namelen;
3129     char	*buffer;
3130     size_t	 buflen;
3131     int		 fd;
3132 };
3133 
3134 static void *
3135 try_library_path(const char *dir, size_t dirlen, void *param)
3136 {
3137     struct try_library_args *arg;
3138     int fd;
3139 
3140     arg = param;
3141     if (*dir == '/' || trust) {
3142 	char *pathname;
3143 
3144 	if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
3145 		return (NULL);
3146 
3147 	pathname = arg->buffer;
3148 	strncpy(pathname, dir, dirlen);
3149 	pathname[dirlen] = '/';
3150 	strcpy(pathname + dirlen + 1, arg->name);
3151 
3152 	dbg("  Trying \"%s\"", pathname);
3153 	fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY);
3154 	if (fd >= 0) {
3155 	    dbg("  Opened \"%s\", fd %d", pathname, fd);
3156 	    pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
3157 	    strcpy(pathname, arg->buffer);
3158 	    arg->fd = fd;
3159 	    return (pathname);
3160 	} else {
3161 	    dbg("  Failed to open \"%s\": %s",
3162 		pathname, rtld_strerror(errno));
3163 	}
3164     }
3165     return (NULL);
3166 }
3167 
3168 static char *
3169 search_library_path(const char *name, const char *path,
3170     const char *refobj_path, int *fdp)
3171 {
3172     char *p;
3173     struct try_library_args arg;
3174 
3175     if (path == NULL)
3176 	return NULL;
3177 
3178     arg.name = name;
3179     arg.namelen = strlen(name);
3180     arg.buffer = xmalloc(PATH_MAX);
3181     arg.buflen = PATH_MAX;
3182     arg.fd = -1;
3183 
3184     p = path_enumerate(path, try_library_path, refobj_path, &arg);
3185     *fdp = arg.fd;
3186 
3187     free(arg.buffer);
3188 
3189     return (p);
3190 }
3191 
3192 
3193 /*
3194  * Finds the library with the given name using the directory descriptors
3195  * listed in the LD_LIBRARY_PATH_FDS environment variable.
3196  *
3197  * Returns a freshly-opened close-on-exec file descriptor for the library,
3198  * or -1 if the library cannot be found.
3199  */
3200 static char *
3201 search_library_pathfds(const char *name, const char *path, int *fdp)
3202 {
3203 	char *envcopy, *fdstr, *found, *last_token;
3204 	size_t len;
3205 	int dirfd, fd;
3206 
3207 	dbg("%s('%s', '%s', fdp)", __func__, name, path);
3208 
3209 	/* Don't load from user-specified libdirs into setuid binaries. */
3210 	if (!trust)
3211 		return (NULL);
3212 
3213 	/* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */
3214 	if (path == NULL)
3215 		return (NULL);
3216 
3217 	/* LD_LIBRARY_PATH_FDS only works with relative paths. */
3218 	if (name[0] == '/') {
3219 		dbg("Absolute path (%s) passed to %s", name, __func__);
3220 		return (NULL);
3221 	}
3222 
3223 	/*
3224 	 * Use strtok_r() to walk the FD:FD:FD list.  This requires a local
3225 	 * copy of the path, as strtok_r rewrites separator tokens
3226 	 * with '\0'.
3227 	 */
3228 	found = NULL;
3229 	envcopy = xstrdup(path);
3230 	for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL;
3231 	    fdstr = strtok_r(NULL, ":", &last_token)) {
3232 		dirfd = parse_integer(fdstr);
3233 		if (dirfd < 0) {
3234 			_rtld_error("failed to parse directory FD: '%s'",
3235 				fdstr);
3236 			break;
3237 		}
3238 		fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY);
3239 		if (fd >= 0) {
3240 			*fdp = fd;
3241 			len = strlen(fdstr) + strlen(name) + 3;
3242 			found = xmalloc(len);
3243 			if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) {
3244 				_rtld_error("error generating '%d/%s'",
3245 				    dirfd, name);
3246 				rtld_die();
3247 			}
3248 			dbg("open('%s') => %d", found, fd);
3249 			break;
3250 		}
3251 	}
3252 	free(envcopy);
3253 
3254 	return (found);
3255 }
3256 
3257 
3258 int
3259 dlclose(void *handle)
3260 {
3261 	RtldLockState lockstate;
3262 	int error;
3263 
3264 	wlock_acquire(rtld_bind_lock, &lockstate);
3265 	error = dlclose_locked(handle, &lockstate);
3266 	lock_release(rtld_bind_lock, &lockstate);
3267 	return (error);
3268 }
3269 
3270 static int
3271 dlclose_locked(void *handle, RtldLockState *lockstate)
3272 {
3273     Obj_Entry *root;
3274 
3275     root = dlcheck(handle);
3276     if (root == NULL)
3277 	return -1;
3278     LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
3279 	root->path);
3280 
3281     /* Unreference the object and its dependencies. */
3282     root->dl_refcount--;
3283 
3284     if (root->refcount == 1) {
3285 	/*
3286 	 * The object will be no longer referenced, so we must unload it.
3287 	 * First, call the fini functions.
3288 	 */
3289 	objlist_call_fini(&list_fini, root, lockstate);
3290 
3291 	unref_dag(root);
3292 
3293 	/* Finish cleaning up the newly-unreferenced objects. */
3294 	GDB_STATE(RT_DELETE,&root->linkmap);
3295 	unload_object(root, lockstate);
3296 	GDB_STATE(RT_CONSISTENT,NULL);
3297     } else
3298 	unref_dag(root);
3299 
3300     LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
3301     return 0;
3302 }
3303 
3304 char *
3305 dlerror(void)
3306 {
3307     char *msg = error_message;
3308     error_message = NULL;
3309     return msg;
3310 }
3311 
3312 /*
3313  * This function is deprecated and has no effect.
3314  */
3315 void
3316 dllockinit(void *context,
3317     void *(*_lock_create)(void *context) __unused,
3318     void (*_rlock_acquire)(void *lock) __unused,
3319     void (*_wlock_acquire)(void *lock)  __unused,
3320     void (*_lock_release)(void *lock) __unused,
3321     void (*_lock_destroy)(void *lock) __unused,
3322     void (*context_destroy)(void *context))
3323 {
3324     static void *cur_context;
3325     static void (*cur_context_destroy)(void *);
3326 
3327     /* Just destroy the context from the previous call, if necessary. */
3328     if (cur_context_destroy != NULL)
3329 	cur_context_destroy(cur_context);
3330     cur_context = context;
3331     cur_context_destroy = context_destroy;
3332 }
3333 
3334 void *
3335 dlopen(const char *name, int mode)
3336 {
3337 
3338 	return (rtld_dlopen(name, -1, mode));
3339 }
3340 
3341 void *
3342 fdlopen(int fd, int mode)
3343 {
3344 
3345 	return (rtld_dlopen(NULL, fd, mode));
3346 }
3347 
3348 static void *
3349 rtld_dlopen(const char *name, int fd, int mode)
3350 {
3351     RtldLockState lockstate;
3352     int lo_flags;
3353 
3354     LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
3355     ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
3356     if (ld_tracing != NULL) {
3357 	rlock_acquire(rtld_bind_lock, &lockstate);
3358 	if (sigsetjmp(lockstate.env, 0) != 0)
3359 	    lock_upgrade(rtld_bind_lock, &lockstate);
3360 	environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate));
3361 	lock_release(rtld_bind_lock, &lockstate);
3362     }
3363     lo_flags = RTLD_LO_DLOPEN;
3364     if (mode & RTLD_NODELETE)
3365 	    lo_flags |= RTLD_LO_NODELETE;
3366     if (mode & RTLD_NOLOAD)
3367 	    lo_flags |= RTLD_LO_NOLOAD;
3368     if (ld_tracing != NULL)
3369 	    lo_flags |= RTLD_LO_TRACE;
3370 
3371     return (dlopen_object(name, fd, obj_main, lo_flags,
3372       mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL));
3373 }
3374 
3375 static void
3376 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate)
3377 {
3378 
3379 	obj->dl_refcount--;
3380 	unref_dag(obj);
3381 	if (obj->refcount == 0)
3382 		unload_object(obj, lockstate);
3383 }
3384 
3385 static Obj_Entry *
3386 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags,
3387     int mode, RtldLockState *lockstate)
3388 {
3389     Obj_Entry *old_obj_tail;
3390     Obj_Entry *obj;
3391     Objlist initlist;
3392     RtldLockState mlockstate;
3393     int result;
3394 
3395     objlist_init(&initlist);
3396 
3397     if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) {
3398 	wlock_acquire(rtld_bind_lock, &mlockstate);
3399 	lockstate = &mlockstate;
3400     }
3401     GDB_STATE(RT_ADD,NULL);
3402 
3403     old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q));
3404     obj = NULL;
3405     if (name == NULL && fd == -1) {
3406 	obj = obj_main;
3407 	obj->refcount++;
3408     } else {
3409 	obj = load_object(name, fd, refobj, lo_flags);
3410     }
3411 
3412     if (obj) {
3413 	obj->dl_refcount++;
3414 	if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
3415 	    objlist_push_tail(&list_global, obj);
3416 	if (globallist_next(old_obj_tail) != NULL) {
3417 	    /* We loaded something new. */
3418 	    assert(globallist_next(old_obj_tail) == obj);
3419 	    result = 0;
3420 	    if ((lo_flags & RTLD_LO_EARLY) == 0 && obj->static_tls &&
3421 	      !allocate_tls_offset(obj)) {
3422 		_rtld_error("%s: No space available "
3423 		  "for static Thread Local Storage", obj->path);
3424 		result = -1;
3425 	    }
3426 	    if (result != -1)
3427 		result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN |
3428 		    RTLD_LO_EARLY));
3429 	    init_dag(obj);
3430 	    ref_dag(obj);
3431 	    if (result != -1)
3432 		result = rtld_verify_versions(&obj->dagmembers);
3433 	    if (result != -1 && ld_tracing)
3434 		goto trace;
3435 	    if (result == -1 || relocate_object_dag(obj,
3436 	      (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld,
3437 	      (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
3438 	      lockstate) == -1) {
3439 		dlopen_cleanup(obj, lockstate);
3440 		obj = NULL;
3441 	    } else if (lo_flags & RTLD_LO_EARLY) {
3442 		/*
3443 		 * Do not call the init functions for early loaded
3444 		 * filtees.  The image is still not initialized enough
3445 		 * for them to work.
3446 		 *
3447 		 * Our object is found by the global object list and
3448 		 * will be ordered among all init calls done right
3449 		 * before transferring control to main.
3450 		 */
3451 	    } else {
3452 		/* Make list of init functions to call. */
3453 		initlist_add_objects(obj, obj, &initlist);
3454 	    }
3455 	    /*
3456 	     * Process all no_delete or global objects here, given
3457 	     * them own DAGs to prevent their dependencies from being
3458 	     * unloaded.  This has to be done after we have loaded all
3459 	     * of the dependencies, so that we do not miss any.
3460 	     */
3461 	    if (obj != NULL)
3462 		process_z(obj);
3463 	} else {
3464 	    /*
3465 	     * Bump the reference counts for objects on this DAG.  If
3466 	     * this is the first dlopen() call for the object that was
3467 	     * already loaded as a dependency, initialize the dag
3468 	     * starting at it.
3469 	     */
3470 	    init_dag(obj);
3471 	    ref_dag(obj);
3472 
3473 	    if ((lo_flags & RTLD_LO_TRACE) != 0)
3474 		goto trace;
3475 	}
3476 	if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
3477 	  obj->z_nodelete) && !obj->ref_nodel) {
3478 	    dbg("obj %s nodelete", obj->path);
3479 	    ref_dag(obj);
3480 	    obj->z_nodelete = obj->ref_nodel = true;
3481 	}
3482     }
3483 
3484     LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
3485 	name);
3486     GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
3487 
3488     if ((lo_flags & RTLD_LO_EARLY) == 0) {
3489 	map_stacks_exec(lockstate);
3490 	if (obj != NULL)
3491 	    distribute_static_tls(&initlist, lockstate);
3492     }
3493 
3494     if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW,
3495       (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
3496       lockstate) == -1) {
3497 	objlist_clear(&initlist);
3498 	dlopen_cleanup(obj, lockstate);
3499 	if (lockstate == &mlockstate)
3500 	    lock_release(rtld_bind_lock, lockstate);
3501 	return (NULL);
3502     }
3503 
3504     if (!(lo_flags & RTLD_LO_EARLY)) {
3505 	/* Call the init functions. */
3506 	objlist_call_init(&initlist, lockstate);
3507     }
3508     objlist_clear(&initlist);
3509     if (lockstate == &mlockstate)
3510 	lock_release(rtld_bind_lock, lockstate);
3511     return obj;
3512 trace:
3513     trace_loaded_objects(obj);
3514     if (lockstate == &mlockstate)
3515 	lock_release(rtld_bind_lock, lockstate);
3516     exit(0);
3517 }
3518 
3519 static void *
3520 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
3521     int flags)
3522 {
3523     DoneList donelist;
3524     const Obj_Entry *obj, *defobj;
3525     const Elf_Sym *def;
3526     SymLook req;
3527     RtldLockState lockstate;
3528     tls_index ti;
3529     void *sym;
3530     int res;
3531 
3532     def = NULL;
3533     defobj = NULL;
3534     symlook_init(&req, name);
3535     req.ventry = ve;
3536     req.flags = flags | SYMLOOK_IN_PLT;
3537     req.lockstate = &lockstate;
3538 
3539     LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name);
3540     rlock_acquire(rtld_bind_lock, &lockstate);
3541     if (sigsetjmp(lockstate.env, 0) != 0)
3542 	    lock_upgrade(rtld_bind_lock, &lockstate);
3543     if (handle == NULL || handle == RTLD_NEXT ||
3544 	handle == RTLD_DEFAULT || handle == RTLD_SELF) {
3545 
3546 	if ((obj = obj_from_addr(retaddr)) == NULL) {
3547 	    _rtld_error("Cannot determine caller's shared object");
3548 	    lock_release(rtld_bind_lock, &lockstate);
3549 	    LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3550 	    return NULL;
3551 	}
3552 	if (handle == NULL) {	/* Just the caller's shared object. */
3553 	    res = symlook_obj(&req, obj);
3554 	    if (res == 0) {
3555 		def = req.sym_out;
3556 		defobj = req.defobj_out;
3557 	    }
3558 	} else if (handle == RTLD_NEXT || /* Objects after caller's */
3559 		   handle == RTLD_SELF) { /* ... caller included */
3560 	    if (handle == RTLD_NEXT)
3561 		obj = globallist_next(obj);
3562 	    for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) {
3563 		if (obj->marker)
3564 		    continue;
3565 		res = symlook_obj(&req, obj);
3566 		if (res == 0) {
3567 		    if (def == NULL ||
3568 		      ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) {
3569 			def = req.sym_out;
3570 			defobj = req.defobj_out;
3571 			if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3572 			    break;
3573 		    }
3574 		}
3575 	    }
3576 	    /*
3577 	     * Search the dynamic linker itself, and possibly resolve the
3578 	     * symbol from there.  This is how the application links to
3579 	     * dynamic linker services such as dlopen.
3580 	     */
3581 	    if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3582 		res = symlook_obj(&req, &obj_rtld);
3583 		if (res == 0) {
3584 		    def = req.sym_out;
3585 		    defobj = req.defobj_out;
3586 		}
3587 	    }
3588 	} else {
3589 	    assert(handle == RTLD_DEFAULT);
3590 	    res = symlook_default(&req, obj);
3591 	    if (res == 0) {
3592 		defobj = req.defobj_out;
3593 		def = req.sym_out;
3594 	    }
3595 	}
3596     } else {
3597 	if ((obj = dlcheck(handle)) == NULL) {
3598 	    lock_release(rtld_bind_lock, &lockstate);
3599 	    LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3600 	    return NULL;
3601 	}
3602 
3603 	donelist_init(&donelist);
3604 	if (obj->mainprog) {
3605             /* Handle obtained by dlopen(NULL, ...) implies global scope. */
3606 	    res = symlook_global(&req, &donelist);
3607 	    if (res == 0) {
3608 		def = req.sym_out;
3609 		defobj = req.defobj_out;
3610 	    }
3611 	    /*
3612 	     * Search the dynamic linker itself, and possibly resolve the
3613 	     * symbol from there.  This is how the application links to
3614 	     * dynamic linker services such as dlopen.
3615 	     */
3616 	    if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3617 		res = symlook_obj(&req, &obj_rtld);
3618 		if (res == 0) {
3619 		    def = req.sym_out;
3620 		    defobj = req.defobj_out;
3621 		}
3622 	    }
3623 	}
3624 	else {
3625 	    /* Search the whole DAG rooted at the given object. */
3626 	    res = symlook_list(&req, &obj->dagmembers, &donelist);
3627 	    if (res == 0) {
3628 		def = req.sym_out;
3629 		defobj = req.defobj_out;
3630 	    }
3631 	}
3632     }
3633 
3634     if (def != NULL) {
3635 	lock_release(rtld_bind_lock, &lockstate);
3636 
3637 	/*
3638 	 * The value required by the caller is derived from the value
3639 	 * of the symbol. this is simply the relocated value of the
3640 	 * symbol.
3641 	 */
3642 	if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
3643 	    sym = make_function_pointer(def, defobj);
3644 	else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
3645 	    sym = rtld_resolve_ifunc(defobj, def);
3646 	else if (ELF_ST_TYPE(def->st_info) == STT_TLS) {
3647 	    ti.ti_module = defobj->tlsindex;
3648 	    ti.ti_offset = def->st_value;
3649 	    sym = __tls_get_addr(&ti);
3650 	} else
3651 	    sym = defobj->relocbase + def->st_value;
3652 	LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name);
3653 	return (sym);
3654     }
3655 
3656     _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "",
3657       ve != NULL ? ve->name : "");
3658     lock_release(rtld_bind_lock, &lockstate);
3659     LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3660     return NULL;
3661 }
3662 
3663 void *
3664 dlsym(void *handle, const char *name)
3665 {
3666 	return do_dlsym(handle, name, __builtin_return_address(0), NULL,
3667 	    SYMLOOK_DLSYM);
3668 }
3669 
3670 dlfunc_t
3671 dlfunc(void *handle, const char *name)
3672 {
3673 	union {
3674 		void *d;
3675 		dlfunc_t f;
3676 	} rv;
3677 
3678 	rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
3679 	    SYMLOOK_DLSYM);
3680 	return (rv.f);
3681 }
3682 
3683 void *
3684 dlvsym(void *handle, const char *name, const char *version)
3685 {
3686 	Ver_Entry ventry;
3687 
3688 	ventry.name = version;
3689 	ventry.file = NULL;
3690 	ventry.hash = elf_hash(version);
3691 	ventry.flags= 0;
3692 	return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
3693 	    SYMLOOK_DLSYM);
3694 }
3695 
3696 int
3697 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
3698 {
3699     const Obj_Entry *obj;
3700     RtldLockState lockstate;
3701 
3702     rlock_acquire(rtld_bind_lock, &lockstate);
3703     obj = obj_from_addr(addr);
3704     if (obj == NULL) {
3705         _rtld_error("No shared object contains address");
3706 	lock_release(rtld_bind_lock, &lockstate);
3707         return (0);
3708     }
3709     rtld_fill_dl_phdr_info(obj, phdr_info);
3710     lock_release(rtld_bind_lock, &lockstate);
3711     return (1);
3712 }
3713 
3714 int
3715 dladdr(const void *addr, Dl_info *info)
3716 {
3717     const Obj_Entry *obj;
3718     const Elf_Sym *def;
3719     void *symbol_addr;
3720     unsigned long symoffset;
3721     RtldLockState lockstate;
3722 
3723     rlock_acquire(rtld_bind_lock, &lockstate);
3724     obj = obj_from_addr(addr);
3725     if (obj == NULL) {
3726         _rtld_error("No shared object contains address");
3727 	lock_release(rtld_bind_lock, &lockstate);
3728         return 0;
3729     }
3730     info->dli_fname = obj->path;
3731     info->dli_fbase = obj->mapbase;
3732     info->dli_saddr = (void *)0;
3733     info->dli_sname = NULL;
3734 
3735     /*
3736      * Walk the symbol list looking for the symbol whose address is
3737      * closest to the address sent in.
3738      */
3739     for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) {
3740         def = obj->symtab + symoffset;
3741 
3742         /*
3743          * For skip the symbol if st_shndx is either SHN_UNDEF or
3744          * SHN_COMMON.
3745          */
3746         if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
3747             continue;
3748 
3749         /*
3750          * If the symbol is greater than the specified address, or if it
3751          * is further away from addr than the current nearest symbol,
3752          * then reject it.
3753          */
3754         symbol_addr = obj->relocbase + def->st_value;
3755         if (symbol_addr > addr || symbol_addr < info->dli_saddr)
3756             continue;
3757 
3758         /* Update our idea of the nearest symbol. */
3759         info->dli_sname = obj->strtab + def->st_name;
3760         info->dli_saddr = symbol_addr;
3761 
3762         /* Exact match? */
3763         if (info->dli_saddr == addr)
3764             break;
3765     }
3766     lock_release(rtld_bind_lock, &lockstate);
3767     return 1;
3768 }
3769 
3770 int
3771 dlinfo(void *handle, int request, void *p)
3772 {
3773     const Obj_Entry *obj;
3774     RtldLockState lockstate;
3775     int error;
3776 
3777     rlock_acquire(rtld_bind_lock, &lockstate);
3778 
3779     if (handle == NULL || handle == RTLD_SELF) {
3780 	void *retaddr;
3781 
3782 	retaddr = __builtin_return_address(0);	/* __GNUC__ only */
3783 	if ((obj = obj_from_addr(retaddr)) == NULL)
3784 	    _rtld_error("Cannot determine caller's shared object");
3785     } else
3786 	obj = dlcheck(handle);
3787 
3788     if (obj == NULL) {
3789 	lock_release(rtld_bind_lock, &lockstate);
3790 	return (-1);
3791     }
3792 
3793     error = 0;
3794     switch (request) {
3795     case RTLD_DI_LINKMAP:
3796 	*((struct link_map const **)p) = &obj->linkmap;
3797 	break;
3798     case RTLD_DI_ORIGIN:
3799 	error = rtld_dirname(obj->path, p);
3800 	break;
3801 
3802     case RTLD_DI_SERINFOSIZE:
3803     case RTLD_DI_SERINFO:
3804 	error = do_search_info(obj, request, (struct dl_serinfo *)p);
3805 	break;
3806 
3807     default:
3808 	_rtld_error("Invalid request %d passed to dlinfo()", request);
3809 	error = -1;
3810     }
3811 
3812     lock_release(rtld_bind_lock, &lockstate);
3813 
3814     return (error);
3815 }
3816 
3817 static void
3818 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
3819 {
3820 
3821 	phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
3822 	phdr_info->dlpi_name = obj->path;
3823 	phdr_info->dlpi_phdr = obj->phdr;
3824 	phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
3825 	phdr_info->dlpi_tls_modid = obj->tlsindex;
3826 	phdr_info->dlpi_tls_data = obj->tlsinit;
3827 	phdr_info->dlpi_adds = obj_loads;
3828 	phdr_info->dlpi_subs = obj_loads - obj_count;
3829 }
3830 
3831 int
3832 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
3833 {
3834 	struct dl_phdr_info phdr_info;
3835 	Obj_Entry *obj, marker;
3836 	RtldLockState bind_lockstate, phdr_lockstate;
3837 	int error;
3838 
3839 	init_marker(&marker);
3840 	error = 0;
3841 
3842 	wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
3843 	wlock_acquire(rtld_bind_lock, &bind_lockstate);
3844 	for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) {
3845 		TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next);
3846 		rtld_fill_dl_phdr_info(obj, &phdr_info);
3847 		hold_object(obj);
3848 		lock_release(rtld_bind_lock, &bind_lockstate);
3849 
3850 		error = callback(&phdr_info, sizeof phdr_info, param);
3851 
3852 		wlock_acquire(rtld_bind_lock, &bind_lockstate);
3853 		unhold_object(obj);
3854 		obj = globallist_next(&marker);
3855 		TAILQ_REMOVE(&obj_list, &marker, next);
3856 		if (error != 0) {
3857 			lock_release(rtld_bind_lock, &bind_lockstate);
3858 			lock_release(rtld_phdr_lock, &phdr_lockstate);
3859 			return (error);
3860 		}
3861 	}
3862 
3863 	if (error == 0) {
3864 		rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info);
3865 		lock_release(rtld_bind_lock, &bind_lockstate);
3866 		error = callback(&phdr_info, sizeof(phdr_info), param);
3867 	}
3868 	lock_release(rtld_phdr_lock, &phdr_lockstate);
3869 	return (error);
3870 }
3871 
3872 static void *
3873 fill_search_info(const char *dir, size_t dirlen, void *param)
3874 {
3875     struct fill_search_info_args *arg;
3876 
3877     arg = param;
3878 
3879     if (arg->request == RTLD_DI_SERINFOSIZE) {
3880 	arg->serinfo->dls_cnt ++;
3881 	arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1;
3882     } else {
3883 	struct dl_serpath *s_entry;
3884 
3885 	s_entry = arg->serpath;
3886 	s_entry->dls_name  = arg->strspace;
3887 	s_entry->dls_flags = arg->flags;
3888 
3889 	strncpy(arg->strspace, dir, dirlen);
3890 	arg->strspace[dirlen] = '\0';
3891 
3892 	arg->strspace += dirlen + 1;
3893 	arg->serpath++;
3894     }
3895 
3896     return (NULL);
3897 }
3898 
3899 static int
3900 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
3901 {
3902     struct dl_serinfo _info;
3903     struct fill_search_info_args args;
3904 
3905     args.request = RTLD_DI_SERINFOSIZE;
3906     args.serinfo = &_info;
3907 
3908     _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
3909     _info.dls_cnt  = 0;
3910 
3911     path_enumerate(obj->rpath, fill_search_info, NULL, &args);
3912     path_enumerate(ld_library_path, fill_search_info, NULL, &args);
3913     path_enumerate(obj->runpath, fill_search_info, NULL, &args);
3914     path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args);
3915     if (!obj->z_nodeflib)
3916       path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args);
3917 
3918 
3919     if (request == RTLD_DI_SERINFOSIZE) {
3920 	info->dls_size = _info.dls_size;
3921 	info->dls_cnt = _info.dls_cnt;
3922 	return (0);
3923     }
3924 
3925     if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
3926 	_rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
3927 	return (-1);
3928     }
3929 
3930     args.request  = RTLD_DI_SERINFO;
3931     args.serinfo  = info;
3932     args.serpath  = &info->dls_serpath[0];
3933     args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
3934 
3935     args.flags = LA_SER_RUNPATH;
3936     if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL)
3937 	return (-1);
3938 
3939     args.flags = LA_SER_LIBPATH;
3940     if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL)
3941 	return (-1);
3942 
3943     args.flags = LA_SER_RUNPATH;
3944     if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL)
3945 	return (-1);
3946 
3947     args.flags = LA_SER_CONFIG;
3948     if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args)
3949       != NULL)
3950 	return (-1);
3951 
3952     args.flags = LA_SER_DEFAULT;
3953     if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path,
3954       fill_search_info, NULL, &args) != NULL)
3955 	return (-1);
3956     return (0);
3957 }
3958 
3959 static int
3960 rtld_dirname(const char *path, char *bname)
3961 {
3962     const char *endp;
3963 
3964     /* Empty or NULL string gets treated as "." */
3965     if (path == NULL || *path == '\0') {
3966 	bname[0] = '.';
3967 	bname[1] = '\0';
3968 	return (0);
3969     }
3970 
3971     /* Strip trailing slashes */
3972     endp = path + strlen(path) - 1;
3973     while (endp > path && *endp == '/')
3974 	endp--;
3975 
3976     /* Find the start of the dir */
3977     while (endp > path && *endp != '/')
3978 	endp--;
3979 
3980     /* Either the dir is "/" or there are no slashes */
3981     if (endp == path) {
3982 	bname[0] = *endp == '/' ? '/' : '.';
3983 	bname[1] = '\0';
3984 	return (0);
3985     } else {
3986 	do {
3987 	    endp--;
3988 	} while (endp > path && *endp == '/');
3989     }
3990 
3991     if (endp - path + 2 > PATH_MAX)
3992     {
3993 	_rtld_error("Filename is too long: %s", path);
3994 	return(-1);
3995     }
3996 
3997     strncpy(bname, path, endp - path + 1);
3998     bname[endp - path + 1] = '\0';
3999     return (0);
4000 }
4001 
4002 static int
4003 rtld_dirname_abs(const char *path, char *base)
4004 {
4005 	char *last;
4006 
4007 	if (realpath(path, base) == NULL) {
4008 		_rtld_error("realpath \"%s\" failed (%s)", path,
4009 		    rtld_strerror(errno));
4010 		return (-1);
4011 	}
4012 	dbg("%s -> %s", path, base);
4013 	last = strrchr(base, '/');
4014 	if (last == NULL) {
4015 		_rtld_error("non-abs result from realpath \"%s\"", path);
4016 		return (-1);
4017 	}
4018 	if (last != base)
4019 		*last = '\0';
4020 	return (0);
4021 }
4022 
4023 static void
4024 linkmap_add(Obj_Entry *obj)
4025 {
4026     struct link_map *l = &obj->linkmap;
4027     struct link_map *prev;
4028 
4029     obj->linkmap.l_name = obj->path;
4030     obj->linkmap.l_addr = obj->mapbase;
4031     obj->linkmap.l_ld = obj->dynamic;
4032 #ifdef __mips__
4033     /* GDB needs load offset on MIPS to use the symbols */
4034     obj->linkmap.l_offs = obj->relocbase;
4035 #endif
4036 
4037     if (r_debug.r_map == NULL) {
4038 	r_debug.r_map = l;
4039 	return;
4040     }
4041 
4042     /*
4043      * Scan to the end of the list, but not past the entry for the
4044      * dynamic linker, which we want to keep at the very end.
4045      */
4046     for (prev = r_debug.r_map;
4047       prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
4048       prev = prev->l_next)
4049 	;
4050 
4051     /* Link in the new entry. */
4052     l->l_prev = prev;
4053     l->l_next = prev->l_next;
4054     if (l->l_next != NULL)
4055 	l->l_next->l_prev = l;
4056     prev->l_next = l;
4057 }
4058 
4059 static void
4060 linkmap_delete(Obj_Entry *obj)
4061 {
4062     struct link_map *l = &obj->linkmap;
4063 
4064     if (l->l_prev == NULL) {
4065 	if ((r_debug.r_map = l->l_next) != NULL)
4066 	    l->l_next->l_prev = NULL;
4067 	return;
4068     }
4069 
4070     if ((l->l_prev->l_next = l->l_next) != NULL)
4071 	l->l_next->l_prev = l->l_prev;
4072 }
4073 
4074 /*
4075  * Function for the debugger to set a breakpoint on to gain control.
4076  *
4077  * The two parameters allow the debugger to easily find and determine
4078  * what the runtime loader is doing and to whom it is doing it.
4079  *
4080  * When the loadhook trap is hit (r_debug_state, set at program
4081  * initialization), the arguments can be found on the stack:
4082  *
4083  *  +8   struct link_map *m
4084  *  +4   struct r_debug  *rd
4085  *  +0   RetAddr
4086  */
4087 void
4088 r_debug_state(struct r_debug* rd __unused, struct link_map *m  __unused)
4089 {
4090     /*
4091      * The following is a hack to force the compiler to emit calls to
4092      * this function, even when optimizing.  If the function is empty,
4093      * the compiler is not obliged to emit any code for calls to it,
4094      * even when marked __noinline.  However, gdb depends on those
4095      * calls being made.
4096      */
4097     __compiler_membar();
4098 }
4099 
4100 /*
4101  * A function called after init routines have completed. This can be used to
4102  * break before a program's entry routine is called, and can be used when
4103  * main is not available in the symbol table.
4104  */
4105 void
4106 _r_debug_postinit(struct link_map *m __unused)
4107 {
4108 
4109 	/* See r_debug_state(). */
4110 	__compiler_membar();
4111 }
4112 
4113 static void
4114 release_object(Obj_Entry *obj)
4115 {
4116 
4117 	if (obj->holdcount > 0) {
4118 		obj->unholdfree = true;
4119 		return;
4120 	}
4121 	munmap(obj->mapbase, obj->mapsize);
4122 	linkmap_delete(obj);
4123 	obj_free(obj);
4124 }
4125 
4126 /*
4127  * Get address of the pointer variable in the main program.
4128  * Prefer non-weak symbol over the weak one.
4129  */
4130 static const void **
4131 get_program_var_addr(const char *name, RtldLockState *lockstate)
4132 {
4133     SymLook req;
4134     DoneList donelist;
4135 
4136     symlook_init(&req, name);
4137     req.lockstate = lockstate;
4138     donelist_init(&donelist);
4139     if (symlook_global(&req, &donelist) != 0)
4140 	return (NULL);
4141     if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC)
4142 	return ((const void **)make_function_pointer(req.sym_out,
4143 	  req.defobj_out));
4144     else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC)
4145 	return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out));
4146     else
4147 	return ((const void **)(req.defobj_out->relocbase +
4148 	  req.sym_out->st_value));
4149 }
4150 
4151 /*
4152  * Set a pointer variable in the main program to the given value.  This
4153  * is used to set key variables such as "environ" before any of the
4154  * init functions are called.
4155  */
4156 static void
4157 set_program_var(const char *name, const void *value)
4158 {
4159     const void **addr;
4160 
4161     if ((addr = get_program_var_addr(name, NULL)) != NULL) {
4162 	dbg("\"%s\": *%p <-- %p", name, addr, value);
4163 	*addr = value;
4164     }
4165 }
4166 
4167 /*
4168  * Search the global objects, including dependencies and main object,
4169  * for the given symbol.
4170  */
4171 static int
4172 symlook_global(SymLook *req, DoneList *donelist)
4173 {
4174     SymLook req1;
4175     const Objlist_Entry *elm;
4176     int res;
4177 
4178     symlook_init_from_req(&req1, req);
4179 
4180     /* Search all objects loaded at program start up. */
4181     if (req->defobj_out == NULL ||
4182       ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
4183 	res = symlook_list(&req1, &list_main, donelist);
4184 	if (res == 0 && (req->defobj_out == NULL ||
4185 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
4186 	    req->sym_out = req1.sym_out;
4187 	    req->defobj_out = req1.defobj_out;
4188 	    assert(req->defobj_out != NULL);
4189 	}
4190     }
4191 
4192     /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
4193     STAILQ_FOREACH(elm, &list_global, link) {
4194 	if (req->defobj_out != NULL &&
4195 	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
4196 	    break;
4197 	res = symlook_list(&req1, &elm->obj->dagmembers, donelist);
4198 	if (res == 0 && (req->defobj_out == NULL ||
4199 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
4200 	    req->sym_out = req1.sym_out;
4201 	    req->defobj_out = req1.defobj_out;
4202 	    assert(req->defobj_out != NULL);
4203 	}
4204     }
4205 
4206     return (req->sym_out != NULL ? 0 : ESRCH);
4207 }
4208 
4209 /*
4210  * Given a symbol name in a referencing object, find the corresponding
4211  * definition of the symbol.  Returns a pointer to the symbol, or NULL if
4212  * no definition was found.  Returns a pointer to the Obj_Entry of the
4213  * defining object via the reference parameter DEFOBJ_OUT.
4214  */
4215 static int
4216 symlook_default(SymLook *req, const Obj_Entry *refobj)
4217 {
4218     DoneList donelist;
4219     const Objlist_Entry *elm;
4220     SymLook req1;
4221     int res;
4222 
4223     donelist_init(&donelist);
4224     symlook_init_from_req(&req1, req);
4225 
4226     /*
4227      * Look first in the referencing object if linked symbolically,
4228      * and similarly handle protected symbols.
4229      */
4230     res = symlook_obj(&req1, refobj);
4231     if (res == 0 && (refobj->symbolic ||
4232       ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) {
4233 	req->sym_out = req1.sym_out;
4234 	req->defobj_out = req1.defobj_out;
4235 	assert(req->defobj_out != NULL);
4236     }
4237     if (refobj->symbolic || req->defobj_out != NULL)
4238 	donelist_check(&donelist, refobj);
4239 
4240     symlook_global(req, &donelist);
4241 
4242     /* Search all dlopened DAGs containing the referencing object. */
4243     STAILQ_FOREACH(elm, &refobj->dldags, link) {
4244 	if (req->sym_out != NULL &&
4245 	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
4246 	    break;
4247 	res = symlook_list(&req1, &elm->obj->dagmembers, &donelist);
4248 	if (res == 0 && (req->sym_out == NULL ||
4249 	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
4250 	    req->sym_out = req1.sym_out;
4251 	    req->defobj_out = req1.defobj_out;
4252 	    assert(req->defobj_out != NULL);
4253 	}
4254     }
4255 
4256     /*
4257      * Search the dynamic linker itself, and possibly resolve the
4258      * symbol from there.  This is how the application links to
4259      * dynamic linker services such as dlopen.
4260      */
4261     if (req->sym_out == NULL ||
4262       ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
4263 	res = symlook_obj(&req1, &obj_rtld);
4264 	if (res == 0) {
4265 	    req->sym_out = req1.sym_out;
4266 	    req->defobj_out = req1.defobj_out;
4267 	    assert(req->defobj_out != NULL);
4268 	}
4269     }
4270 
4271     return (req->sym_out != NULL ? 0 : ESRCH);
4272 }
4273 
4274 static int
4275 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp)
4276 {
4277     const Elf_Sym *def;
4278     const Obj_Entry *defobj;
4279     const Objlist_Entry *elm;
4280     SymLook req1;
4281     int res;
4282 
4283     def = NULL;
4284     defobj = NULL;
4285     STAILQ_FOREACH(elm, objlist, link) {
4286 	if (donelist_check(dlp, elm->obj))
4287 	    continue;
4288 	symlook_init_from_req(&req1, req);
4289 	if ((res = symlook_obj(&req1, elm->obj)) == 0) {
4290 	    if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
4291 		def = req1.sym_out;
4292 		defobj = req1.defobj_out;
4293 		if (ELF_ST_BIND(def->st_info) != STB_WEAK)
4294 		    break;
4295 	    }
4296 	}
4297     }
4298     if (def != NULL) {
4299 	req->sym_out = def;
4300 	req->defobj_out = defobj;
4301 	return (0);
4302     }
4303     return (ESRCH);
4304 }
4305 
4306 /*
4307  * Search the chain of DAGS cointed to by the given Needed_Entry
4308  * for a symbol of the given name.  Each DAG is scanned completely
4309  * before advancing to the next one.  Returns a pointer to the symbol,
4310  * or NULL if no definition was found.
4311  */
4312 static int
4313 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp)
4314 {
4315     const Elf_Sym *def;
4316     const Needed_Entry *n;
4317     const Obj_Entry *defobj;
4318     SymLook req1;
4319     int res;
4320 
4321     def = NULL;
4322     defobj = NULL;
4323     symlook_init_from_req(&req1, req);
4324     for (n = needed; n != NULL; n = n->next) {
4325 	if (n->obj == NULL ||
4326 	    (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0)
4327 	    continue;
4328 	if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
4329 	    def = req1.sym_out;
4330 	    defobj = req1.defobj_out;
4331 	    if (ELF_ST_BIND(def->st_info) != STB_WEAK)
4332 		break;
4333 	}
4334     }
4335     if (def != NULL) {
4336 	req->sym_out = def;
4337 	req->defobj_out = defobj;
4338 	return (0);
4339     }
4340     return (ESRCH);
4341 }
4342 
4343 /*
4344  * Search the symbol table of a single shared object for a symbol of
4345  * the given name and version, if requested.  Returns a pointer to the
4346  * symbol, or NULL if no definition was found.  If the object is
4347  * filter, return filtered symbol from filtee.
4348  *
4349  * The symbol's hash value is passed in for efficiency reasons; that
4350  * eliminates many recomputations of the hash value.
4351  */
4352 int
4353 symlook_obj(SymLook *req, const Obj_Entry *obj)
4354 {
4355     DoneList donelist;
4356     SymLook req1;
4357     int flags, res, mres;
4358 
4359     /*
4360      * If there is at least one valid hash at this point, we prefer to
4361      * use the faster GNU version if available.
4362      */
4363     if (obj->valid_hash_gnu)
4364 	mres = symlook_obj1_gnu(req, obj);
4365     else if (obj->valid_hash_sysv)
4366 	mres = symlook_obj1_sysv(req, obj);
4367     else
4368 	return (EINVAL);
4369 
4370     if (mres == 0) {
4371 	if (obj->needed_filtees != NULL) {
4372 	    flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
4373 	    load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
4374 	    donelist_init(&donelist);
4375 	    symlook_init_from_req(&req1, req);
4376 	    res = symlook_needed(&req1, obj->needed_filtees, &donelist);
4377 	    if (res == 0) {
4378 		req->sym_out = req1.sym_out;
4379 		req->defobj_out = req1.defobj_out;
4380 	    }
4381 	    return (res);
4382 	}
4383 	if (obj->needed_aux_filtees != NULL) {
4384 	    flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
4385 	    load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
4386 	    donelist_init(&donelist);
4387 	    symlook_init_from_req(&req1, req);
4388 	    res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist);
4389 	    if (res == 0) {
4390 		req->sym_out = req1.sym_out;
4391 		req->defobj_out = req1.defobj_out;
4392 		return (res);
4393 	    }
4394 	}
4395     }
4396     return (mres);
4397 }
4398 
4399 /* Symbol match routine common to both hash functions */
4400 static bool
4401 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result,
4402     const unsigned long symnum)
4403 {
4404 	Elf_Versym verndx;
4405 	const Elf_Sym *symp;
4406 	const char *strp;
4407 
4408 	symp = obj->symtab + symnum;
4409 	strp = obj->strtab + symp->st_name;
4410 
4411 	switch (ELF_ST_TYPE(symp->st_info)) {
4412 	case STT_FUNC:
4413 	case STT_NOTYPE:
4414 	case STT_OBJECT:
4415 	case STT_COMMON:
4416 	case STT_GNU_IFUNC:
4417 		if (symp->st_value == 0)
4418 			return (false);
4419 		/* fallthrough */
4420 	case STT_TLS:
4421 		if (symp->st_shndx != SHN_UNDEF)
4422 			break;
4423 #ifndef __mips__
4424 		else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
4425 		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
4426 			break;
4427 #endif
4428 		/* fallthrough */
4429 	default:
4430 		return (false);
4431 	}
4432 	if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0)
4433 		return (false);
4434 
4435 	if (req->ventry == NULL) {
4436 		if (obj->versyms != NULL) {
4437 			verndx = VER_NDX(obj->versyms[symnum]);
4438 			if (verndx > obj->vernum) {
4439 				_rtld_error(
4440 				    "%s: symbol %s references wrong version %d",
4441 				    obj->path, obj->strtab + symnum, verndx);
4442 				return (false);
4443 			}
4444 			/*
4445 			 * If we are not called from dlsym (i.e. this
4446 			 * is a normal relocation from unversioned
4447 			 * binary), accept the symbol immediately if
4448 			 * it happens to have first version after this
4449 			 * shared object became versioned.  Otherwise,
4450 			 * if symbol is versioned and not hidden,
4451 			 * remember it. If it is the only symbol with
4452 			 * this name exported by the shared object, it
4453 			 * will be returned as a match by the calling
4454 			 * function. If symbol is global (verndx < 2)
4455 			 * accept it unconditionally.
4456 			 */
4457 			if ((req->flags & SYMLOOK_DLSYM) == 0 &&
4458 			    verndx == VER_NDX_GIVEN) {
4459 				result->sym_out = symp;
4460 				return (true);
4461 			}
4462 			else if (verndx >= VER_NDX_GIVEN) {
4463 				if ((obj->versyms[symnum] & VER_NDX_HIDDEN)
4464 				    == 0) {
4465 					if (result->vsymp == NULL)
4466 						result->vsymp = symp;
4467 					result->vcount++;
4468 				}
4469 				return (false);
4470 			}
4471 		}
4472 		result->sym_out = symp;
4473 		return (true);
4474 	}
4475 	if (obj->versyms == NULL) {
4476 		if (object_match_name(obj, req->ventry->name)) {
4477 			_rtld_error("%s: object %s should provide version %s "
4478 			    "for symbol %s", obj_rtld.path, obj->path,
4479 			    req->ventry->name, obj->strtab + symnum);
4480 			return (false);
4481 		}
4482 	} else {
4483 		verndx = VER_NDX(obj->versyms[symnum]);
4484 		if (verndx > obj->vernum) {
4485 			_rtld_error("%s: symbol %s references wrong version %d",
4486 			    obj->path, obj->strtab + symnum, verndx);
4487 			return (false);
4488 		}
4489 		if (obj->vertab[verndx].hash != req->ventry->hash ||
4490 		    strcmp(obj->vertab[verndx].name, req->ventry->name)) {
4491 			/*
4492 			 * Version does not match. Look if this is a
4493 			 * global symbol and if it is not hidden. If
4494 			 * global symbol (verndx < 2) is available,
4495 			 * use it. Do not return symbol if we are
4496 			 * called by dlvsym, because dlvsym looks for
4497 			 * a specific version and default one is not
4498 			 * what dlvsym wants.
4499 			 */
4500 			if ((req->flags & SYMLOOK_DLSYM) ||
4501 			    (verndx >= VER_NDX_GIVEN) ||
4502 			    (obj->versyms[symnum] & VER_NDX_HIDDEN))
4503 				return (false);
4504 		}
4505 	}
4506 	result->sym_out = symp;
4507 	return (true);
4508 }
4509 
4510 /*
4511  * Search for symbol using SysV hash function.
4512  * obj->buckets is known not to be NULL at this point; the test for this was
4513  * performed with the obj->valid_hash_sysv assignment.
4514  */
4515 static int
4516 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj)
4517 {
4518 	unsigned long symnum;
4519 	Sym_Match_Result matchres;
4520 
4521 	matchres.sym_out = NULL;
4522 	matchres.vsymp = NULL;
4523 	matchres.vcount = 0;
4524 
4525 	for (symnum = obj->buckets[req->hash % obj->nbuckets];
4526 	    symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
4527 		if (symnum >= obj->nchains)
4528 			return (ESRCH);	/* Bad object */
4529 
4530 		if (matched_symbol(req, obj, &matchres, symnum)) {
4531 			req->sym_out = matchres.sym_out;
4532 			req->defobj_out = obj;
4533 			return (0);
4534 		}
4535 	}
4536 	if (matchres.vcount == 1) {
4537 		req->sym_out = matchres.vsymp;
4538 		req->defobj_out = obj;
4539 		return (0);
4540 	}
4541 	return (ESRCH);
4542 }
4543 
4544 /* Search for symbol using GNU hash function */
4545 static int
4546 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj)
4547 {
4548 	Elf_Addr bloom_word;
4549 	const Elf32_Word *hashval;
4550 	Elf32_Word bucket;
4551 	Sym_Match_Result matchres;
4552 	unsigned int h1, h2;
4553 	unsigned long symnum;
4554 
4555 	matchres.sym_out = NULL;
4556 	matchres.vsymp = NULL;
4557 	matchres.vcount = 0;
4558 
4559 	/* Pick right bitmask word from Bloom filter array */
4560 	bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) &
4561 	    obj->maskwords_bm_gnu];
4562 
4563 	/* Calculate modulus word size of gnu hash and its derivative */
4564 	h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1);
4565 	h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1));
4566 
4567 	/* Filter out the "definitely not in set" queries */
4568 	if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0)
4569 		return (ESRCH);
4570 
4571 	/* Locate hash chain and corresponding value element*/
4572 	bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu];
4573 	if (bucket == 0)
4574 		return (ESRCH);
4575 	hashval = &obj->chain_zero_gnu[bucket];
4576 	do {
4577 		if (((*hashval ^ req->hash_gnu) >> 1) == 0) {
4578 			symnum = hashval - obj->chain_zero_gnu;
4579 			if (matched_symbol(req, obj, &matchres, symnum)) {
4580 				req->sym_out = matchres.sym_out;
4581 				req->defobj_out = obj;
4582 				return (0);
4583 			}
4584 		}
4585 	} while ((*hashval++ & 1) == 0);
4586 	if (matchres.vcount == 1) {
4587 		req->sym_out = matchres.vsymp;
4588 		req->defobj_out = obj;
4589 		return (0);
4590 	}
4591 	return (ESRCH);
4592 }
4593 
4594 static void
4595 trace_loaded_objects(Obj_Entry *obj)
4596 {
4597     const char *fmt1, *fmt2, *fmt, *main_local, *list_containers;
4598     int c;
4599 
4600     if ((main_local = getenv(_LD("TRACE_LOADED_OBJECTS_PROGNAME"))) == NULL)
4601 	main_local = "";
4602 
4603     if ((fmt1 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT1"))) == NULL)
4604 	fmt1 = "\t%o => %p (%x)\n";
4605 
4606     if ((fmt2 = getenv(_LD("TRACE_LOADED_OBJECTS_FMT2"))) == NULL)
4607 	fmt2 = "\t%o (%x)\n";
4608 
4609     list_containers = getenv(_LD("TRACE_LOADED_OBJECTS_ALL"));
4610 
4611     for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) {
4612 	Needed_Entry *needed;
4613 	const char *name, *path;
4614 	bool is_lib;
4615 
4616 	if (obj->marker)
4617 	    continue;
4618 	if (list_containers && obj->needed != NULL)
4619 	    rtld_printf("%s:\n", obj->path);
4620 	for (needed = obj->needed; needed; needed = needed->next) {
4621 	    if (needed->obj != NULL) {
4622 		if (needed->obj->traced && !list_containers)
4623 		    continue;
4624 		needed->obj->traced = true;
4625 		path = needed->obj->path;
4626 	    } else
4627 		path = "not found";
4628 
4629 	    name = obj->strtab + needed->name;
4630 	    is_lib = strncmp(name, "lib", 3) == 0;	/* XXX - bogus */
4631 
4632 	    fmt = is_lib ? fmt1 : fmt2;
4633 	    while ((c = *fmt++) != '\0') {
4634 		switch (c) {
4635 		default:
4636 		    rtld_putchar(c);
4637 		    continue;
4638 		case '\\':
4639 		    switch (c = *fmt) {
4640 		    case '\0':
4641 			continue;
4642 		    case 'n':
4643 			rtld_putchar('\n');
4644 			break;
4645 		    case 't':
4646 			rtld_putchar('\t');
4647 			break;
4648 		    }
4649 		    break;
4650 		case '%':
4651 		    switch (c = *fmt) {
4652 		    case '\0':
4653 			continue;
4654 		    case '%':
4655 		    default:
4656 			rtld_putchar(c);
4657 			break;
4658 		    case 'A':
4659 			rtld_putstr(main_local);
4660 			break;
4661 		    case 'a':
4662 			rtld_putstr(obj_main->path);
4663 			break;
4664 		    case 'o':
4665 			rtld_putstr(name);
4666 			break;
4667 #if 0
4668 		    case 'm':
4669 			rtld_printf("%d", sodp->sod_major);
4670 			break;
4671 		    case 'n':
4672 			rtld_printf("%d", sodp->sod_minor);
4673 			break;
4674 #endif
4675 		    case 'p':
4676 			rtld_putstr(path);
4677 			break;
4678 		    case 'x':
4679 			rtld_printf("%p", needed->obj ? needed->obj->mapbase :
4680 			  0);
4681 			break;
4682 		    }
4683 		    break;
4684 		}
4685 		++fmt;
4686 	    }
4687 	}
4688     }
4689 }
4690 
4691 /*
4692  * Unload a dlopened object and its dependencies from memory and from
4693  * our data structures.  It is assumed that the DAG rooted in the
4694  * object has already been unreferenced, and that the object has a
4695  * reference count of 0.
4696  */
4697 static void
4698 unload_object(Obj_Entry *root, RtldLockState *lockstate)
4699 {
4700 	Obj_Entry marker, *obj, *next;
4701 
4702 	assert(root->refcount == 0);
4703 
4704 	/*
4705 	 * Pass over the DAG removing unreferenced objects from
4706 	 * appropriate lists.
4707 	 */
4708 	unlink_object(root);
4709 
4710 	/* Unmap all objects that are no longer referenced. */
4711 	for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) {
4712 		next = TAILQ_NEXT(obj, next);
4713 		if (obj->marker || obj->refcount != 0)
4714 			continue;
4715 		LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase,
4716 		    obj->mapsize, 0, obj->path);
4717 		dbg("unloading \"%s\"", obj->path);
4718 		/*
4719 		 * Unlink the object now to prevent new references from
4720 		 * being acquired while the bind lock is dropped in
4721 		 * recursive dlclose() invocations.
4722 		 */
4723 		TAILQ_REMOVE(&obj_list, obj, next);
4724 		obj_count--;
4725 
4726 		if (obj->filtees_loaded) {
4727 			if (next != NULL) {
4728 				init_marker(&marker);
4729 				TAILQ_INSERT_BEFORE(next, &marker, next);
4730 				unload_filtees(obj, lockstate);
4731 				next = TAILQ_NEXT(&marker, next);
4732 				TAILQ_REMOVE(&obj_list, &marker, next);
4733 			} else
4734 				unload_filtees(obj, lockstate);
4735 		}
4736 		release_object(obj);
4737 	}
4738 }
4739 
4740 static void
4741 unlink_object(Obj_Entry *root)
4742 {
4743     Objlist_Entry *elm;
4744 
4745     if (root->refcount == 0) {
4746 	/* Remove the object from the RTLD_GLOBAL list. */
4747 	objlist_remove(&list_global, root);
4748 
4749     	/* Remove the object from all objects' DAG lists. */
4750     	STAILQ_FOREACH(elm, &root->dagmembers, link) {
4751 	    objlist_remove(&elm->obj->dldags, root);
4752 	    if (elm->obj != root)
4753 		unlink_object(elm->obj);
4754 	}
4755     }
4756 }
4757 
4758 static void
4759 ref_dag(Obj_Entry *root)
4760 {
4761     Objlist_Entry *elm;
4762 
4763     assert(root->dag_inited);
4764     STAILQ_FOREACH(elm, &root->dagmembers, link)
4765 	elm->obj->refcount++;
4766 }
4767 
4768 static void
4769 unref_dag(Obj_Entry *root)
4770 {
4771     Objlist_Entry *elm;
4772 
4773     assert(root->dag_inited);
4774     STAILQ_FOREACH(elm, &root->dagmembers, link)
4775 	elm->obj->refcount--;
4776 }
4777 
4778 /*
4779  * Common code for MD __tls_get_addr().
4780  */
4781 static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline;
4782 static void *
4783 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset)
4784 {
4785     Elf_Addr *newdtv, *dtv;
4786     RtldLockState lockstate;
4787     int to_copy;
4788 
4789     dtv = *dtvp;
4790     /* Check dtv generation in case new modules have arrived */
4791     if (dtv[0] != tls_dtv_generation) {
4792 	wlock_acquire(rtld_bind_lock, &lockstate);
4793 	newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4794 	to_copy = dtv[1];
4795 	if (to_copy > tls_max_index)
4796 	    to_copy = tls_max_index;
4797 	memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
4798 	newdtv[0] = tls_dtv_generation;
4799 	newdtv[1] = tls_max_index;
4800 	free(dtv);
4801 	lock_release(rtld_bind_lock, &lockstate);
4802 	dtv = *dtvp = newdtv;
4803     }
4804 
4805     /* Dynamically allocate module TLS if necessary */
4806     if (dtv[index + 1] == 0) {
4807 	/* Signal safe, wlock will block out signals. */
4808 	wlock_acquire(rtld_bind_lock, &lockstate);
4809 	if (!dtv[index + 1])
4810 	    dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
4811 	lock_release(rtld_bind_lock, &lockstate);
4812     }
4813     return ((void *)(dtv[index + 1] + offset));
4814 }
4815 
4816 void *
4817 tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset)
4818 {
4819 	Elf_Addr *dtv;
4820 
4821 	dtv = *dtvp;
4822 	/* Check dtv generation in case new modules have arrived */
4823 	if (__predict_true(dtv[0] == tls_dtv_generation &&
4824 	    dtv[index + 1] != 0))
4825 		return ((void *)(dtv[index + 1] + offset));
4826 	return (tls_get_addr_slow(dtvp, index, offset));
4827 }
4828 
4829 #if defined(__aarch64__) || defined(__arm__) || defined(__mips__) || \
4830     defined(__powerpc__) || defined(__riscv)
4831 
4832 /*
4833  * Return pointer to allocated TLS block
4834  */
4835 static void *
4836 get_tls_block_ptr(void *tcb, size_t tcbsize)
4837 {
4838     size_t extra_size, post_size, pre_size, tls_block_size;
4839     size_t tls_init_align;
4840 
4841     tls_init_align = MAX(obj_main->tlsalign, 1);
4842 
4843     /* Compute fragments sizes. */
4844     extra_size = tcbsize - TLS_TCB_SIZE;
4845     post_size = calculate_tls_post_size(tls_init_align);
4846     tls_block_size = tcbsize + post_size;
4847     pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size;
4848 
4849     return ((char *)tcb - pre_size - extra_size);
4850 }
4851 
4852 /*
4853  * Allocate Static TLS using the Variant I method.
4854  *
4855  * For details on the layout, see lib/libc/gen/tls.c.
4856  *
4857  * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as
4858  *     it is based on tls_last_offset, and TLS offsets here are really TCB
4859  *     offsets, whereas libc's tls_static_space is just the executable's static
4860  *     TLS segment.
4861  */
4862 void *
4863 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
4864 {
4865     Obj_Entry *obj;
4866     char *tls_block;
4867     Elf_Addr *dtv, **tcb;
4868     Elf_Addr addr;
4869     Elf_Addr i;
4870     size_t extra_size, maxalign, post_size, pre_size, tls_block_size;
4871     size_t tls_init_align;
4872 
4873     if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
4874 	return (oldtcb);
4875 
4876     assert(tcbsize >= TLS_TCB_SIZE);
4877     maxalign = MAX(tcbalign, tls_static_max_align);
4878     tls_init_align = MAX(obj_main->tlsalign, 1);
4879 
4880     /* Compute fragmets sizes. */
4881     extra_size = tcbsize - TLS_TCB_SIZE;
4882     post_size = calculate_tls_post_size(tls_init_align);
4883     tls_block_size = tcbsize + post_size;
4884     pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size;
4885     tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size;
4886 
4887     /* Allocate whole TLS block */
4888     tls_block = malloc_aligned(tls_block_size, maxalign);
4889     tcb = (Elf_Addr **)(tls_block + pre_size + extra_size);
4890 
4891     if (oldtcb != NULL) {
4892 	memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize),
4893 	    tls_static_space);
4894 	free_aligned(get_tls_block_ptr(oldtcb, tcbsize));
4895 
4896 	/* Adjust the DTV. */
4897 	dtv = tcb[0];
4898 	for (i = 0; i < dtv[1]; i++) {
4899 	    if (dtv[i+2] >= (Elf_Addr)oldtcb &&
4900 		dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
4901 		dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb;
4902 	    }
4903 	}
4904     } else {
4905 	dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4906 	tcb[0] = dtv;
4907 	dtv[0] = tls_dtv_generation;
4908 	dtv[1] = tls_max_index;
4909 
4910 	for (obj = globallist_curr(objs); obj != NULL;
4911 	  obj = globallist_next(obj)) {
4912 	    if (obj->tlsoffset > 0) {
4913 		addr = (Elf_Addr)tcb + obj->tlsoffset;
4914 		if (obj->tlsinitsize > 0)
4915 		    memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
4916 		if (obj->tlssize > obj->tlsinitsize)
4917 		    memset((void*)(addr + obj->tlsinitsize), 0,
4918 			   obj->tlssize - obj->tlsinitsize);
4919 		dtv[obj->tlsindex + 1] = addr;
4920 	    }
4921 	}
4922     }
4923 
4924     return (tcb);
4925 }
4926 
4927 void
4928 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused)
4929 {
4930     Elf_Addr *dtv;
4931     Elf_Addr tlsstart, tlsend;
4932     size_t post_size;
4933     size_t dtvsize, i, tls_init_align;
4934 
4935     assert(tcbsize >= TLS_TCB_SIZE);
4936     tls_init_align = MAX(obj_main->tlsalign, 1);
4937 
4938     /* Compute fragments sizes. */
4939     post_size = calculate_tls_post_size(tls_init_align);
4940 
4941     tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size;
4942     tlsend = (Elf_Addr)tcb + tls_static_space;
4943 
4944     dtv = *(Elf_Addr **)tcb;
4945     dtvsize = dtv[1];
4946     for (i = 0; i < dtvsize; i++) {
4947 	if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
4948 	    free((void*)dtv[i+2]);
4949 	}
4950     }
4951     free(dtv);
4952     free_aligned(get_tls_block_ptr(tcb, tcbsize));
4953 }
4954 
4955 #endif
4956 
4957 #if defined(__i386__) || defined(__amd64__)
4958 
4959 /*
4960  * Allocate Static TLS using the Variant II method.
4961  */
4962 void *
4963 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
4964 {
4965     Obj_Entry *obj;
4966     size_t size, ralign;
4967     char *tls;
4968     Elf_Addr *dtv, *olddtv;
4969     Elf_Addr segbase, oldsegbase, addr;
4970     size_t i;
4971 
4972     ralign = tcbalign;
4973     if (tls_static_max_align > ralign)
4974 	    ralign = tls_static_max_align;
4975     size = round(tls_static_space, ralign) + round(tcbsize, ralign);
4976 
4977     assert(tcbsize >= 2*sizeof(Elf_Addr));
4978     tls = malloc_aligned(size, ralign);
4979     dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4980 
4981     segbase = (Elf_Addr)(tls + round(tls_static_space, ralign));
4982     ((Elf_Addr*)segbase)[0] = segbase;
4983     ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
4984 
4985     dtv[0] = tls_dtv_generation;
4986     dtv[1] = tls_max_index;
4987 
4988     if (oldtls) {
4989 	/*
4990 	 * Copy the static TLS block over whole.
4991 	 */
4992 	oldsegbase = (Elf_Addr) oldtls;
4993 	memcpy((void *)(segbase - tls_static_space),
4994 	       (const void *)(oldsegbase - tls_static_space),
4995 	       tls_static_space);
4996 
4997 	/*
4998 	 * If any dynamic TLS blocks have been created tls_get_addr(),
4999 	 * move them over.
5000 	 */
5001 	olddtv = ((Elf_Addr**)oldsegbase)[1];
5002 	for (i = 0; i < olddtv[1]; i++) {
5003 	    if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) {
5004 		dtv[i+2] = olddtv[i+2];
5005 		olddtv[i+2] = 0;
5006 	    }
5007 	}
5008 
5009 	/*
5010 	 * We assume that this block was the one we created with
5011 	 * allocate_initial_tls().
5012 	 */
5013 	free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
5014     } else {
5015 	for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) {
5016 		if (obj->marker || obj->tlsoffset == 0)
5017 			continue;
5018 		addr = segbase - obj->tlsoffset;
5019 		memset((void*)(addr + obj->tlsinitsize),
5020 		       0, obj->tlssize - obj->tlsinitsize);
5021 		if (obj->tlsinit) {
5022 		    memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
5023 		    obj->static_tls_copied = true;
5024 		}
5025 		dtv[obj->tlsindex + 1] = addr;
5026 	}
5027     }
5028 
5029     return (void*) segbase;
5030 }
5031 
5032 void
5033 free_tls(void *tls, size_t tcbsize  __unused, size_t tcbalign)
5034 {
5035     Elf_Addr* dtv;
5036     size_t size, ralign;
5037     int dtvsize, i;
5038     Elf_Addr tlsstart, tlsend;
5039 
5040     /*
5041      * Figure out the size of the initial TLS block so that we can
5042      * find stuff which ___tls_get_addr() allocated dynamically.
5043      */
5044     ralign = tcbalign;
5045     if (tls_static_max_align > ralign)
5046 	    ralign = tls_static_max_align;
5047     size = round(tls_static_space, ralign);
5048 
5049     dtv = ((Elf_Addr**)tls)[1];
5050     dtvsize = dtv[1];
5051     tlsend = (Elf_Addr) tls;
5052     tlsstart = tlsend - size;
5053     for (i = 0; i < dtvsize; i++) {
5054 	if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) {
5055 		free_aligned((void *)dtv[i + 2]);
5056 	}
5057     }
5058 
5059     free_aligned((void *)tlsstart);
5060     free((void*) dtv);
5061 }
5062 
5063 #endif
5064 
5065 /*
5066  * Allocate TLS block for module with given index.
5067  */
5068 void *
5069 allocate_module_tls(int index)
5070 {
5071     Obj_Entry* obj;
5072     char* p;
5073 
5074     TAILQ_FOREACH(obj, &obj_list, next) {
5075 	if (obj->marker)
5076 	    continue;
5077 	if (obj->tlsindex == index)
5078 	    break;
5079     }
5080     if (!obj) {
5081 	_rtld_error("Can't find module with TLS index %d", index);
5082 	rtld_die();
5083     }
5084 
5085     p = malloc_aligned(obj->tlssize, obj->tlsalign);
5086     memcpy(p, obj->tlsinit, obj->tlsinitsize);
5087     memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
5088 
5089     return p;
5090 }
5091 
5092 bool
5093 allocate_tls_offset(Obj_Entry *obj)
5094 {
5095     size_t off;
5096 
5097     if (obj->tls_done)
5098 	return true;
5099 
5100     if (obj->tlssize == 0) {
5101 	obj->tls_done = true;
5102 	return true;
5103     }
5104 
5105     if (tls_last_offset == 0)
5106 	off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
5107     else
5108 	off = calculate_tls_offset(tls_last_offset, tls_last_size,
5109 				   obj->tlssize, obj->tlsalign);
5110 
5111     /*
5112      * If we have already fixed the size of the static TLS block, we
5113      * must stay within that size. When allocating the static TLS, we
5114      * leave a small amount of space spare to be used for dynamically
5115      * loading modules which use static TLS.
5116      */
5117     if (tls_static_space != 0) {
5118 	if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
5119 	    return false;
5120     } else if (obj->tlsalign > tls_static_max_align) {
5121 	    tls_static_max_align = obj->tlsalign;
5122     }
5123 
5124     tls_last_offset = obj->tlsoffset = off;
5125     tls_last_size = obj->tlssize;
5126     obj->tls_done = true;
5127 
5128     return true;
5129 }
5130 
5131 void
5132 free_tls_offset(Obj_Entry *obj)
5133 {
5134 
5135     /*
5136      * If we were the last thing to allocate out of the static TLS
5137      * block, we give our space back to the 'allocator'. This is a
5138      * simplistic workaround to allow libGL.so.1 to be loaded and
5139      * unloaded multiple times.
5140      */
5141     if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
5142 	== calculate_tls_end(tls_last_offset, tls_last_size)) {
5143 	tls_last_offset -= obj->tlssize;
5144 	tls_last_size = 0;
5145     }
5146 }
5147 
5148 void *
5149 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
5150 {
5151     void *ret;
5152     RtldLockState lockstate;
5153 
5154     wlock_acquire(rtld_bind_lock, &lockstate);
5155     ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls,
5156       tcbsize, tcbalign);
5157     lock_release(rtld_bind_lock, &lockstate);
5158     return (ret);
5159 }
5160 
5161 void
5162 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
5163 {
5164     RtldLockState lockstate;
5165 
5166     wlock_acquire(rtld_bind_lock, &lockstate);
5167     free_tls(tcb, tcbsize, tcbalign);
5168     lock_release(rtld_bind_lock, &lockstate);
5169 }
5170 
5171 static void
5172 object_add_name(Obj_Entry *obj, const char *name)
5173 {
5174     Name_Entry *entry;
5175     size_t len;
5176 
5177     len = strlen(name);
5178     entry = malloc(sizeof(Name_Entry) + len);
5179 
5180     if (entry != NULL) {
5181 	strcpy(entry->name, name);
5182 	STAILQ_INSERT_TAIL(&obj->names, entry, link);
5183     }
5184 }
5185 
5186 static int
5187 object_match_name(const Obj_Entry *obj, const char *name)
5188 {
5189     Name_Entry *entry;
5190 
5191     STAILQ_FOREACH(entry, &obj->names, link) {
5192 	if (strcmp(name, entry->name) == 0)
5193 	    return (1);
5194     }
5195     return (0);
5196 }
5197 
5198 static Obj_Entry *
5199 locate_dependency(const Obj_Entry *obj, const char *name)
5200 {
5201     const Objlist_Entry *entry;
5202     const Needed_Entry *needed;
5203 
5204     STAILQ_FOREACH(entry, &list_main, link) {
5205 	if (object_match_name(entry->obj, name))
5206 	    return entry->obj;
5207     }
5208 
5209     for (needed = obj->needed;  needed != NULL;  needed = needed->next) {
5210 	if (strcmp(obj->strtab + needed->name, name) == 0 ||
5211 	  (needed->obj != NULL && object_match_name(needed->obj, name))) {
5212 	    /*
5213 	     * If there is DT_NEEDED for the name we are looking for,
5214 	     * we are all set.  Note that object might not be found if
5215 	     * dependency was not loaded yet, so the function can
5216 	     * return NULL here.  This is expected and handled
5217 	     * properly by the caller.
5218 	     */
5219 	    return (needed->obj);
5220 	}
5221     }
5222     _rtld_error("%s: Unexpected inconsistency: dependency %s not found",
5223 	obj->path, name);
5224     rtld_die();
5225 }
5226 
5227 static int
5228 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
5229     const Elf_Vernaux *vna)
5230 {
5231     const Elf_Verdef *vd;
5232     const char *vername;
5233 
5234     vername = refobj->strtab + vna->vna_name;
5235     vd = depobj->verdef;
5236     if (vd == NULL) {
5237 	_rtld_error("%s: version %s required by %s not defined",
5238 	    depobj->path, vername, refobj->path);
5239 	return (-1);
5240     }
5241     for (;;) {
5242 	if (vd->vd_version != VER_DEF_CURRENT) {
5243 	    _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
5244 		depobj->path, vd->vd_version);
5245 	    return (-1);
5246 	}
5247 	if (vna->vna_hash == vd->vd_hash) {
5248 	    const Elf_Verdaux *aux = (const Elf_Verdaux *)
5249 		((const char *)vd + vd->vd_aux);
5250 	    if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
5251 		return (0);
5252 	}
5253 	if (vd->vd_next == 0)
5254 	    break;
5255 	vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next);
5256     }
5257     if (vna->vna_flags & VER_FLG_WEAK)
5258 	return (0);
5259     _rtld_error("%s: version %s required by %s not found",
5260 	depobj->path, vername, refobj->path);
5261     return (-1);
5262 }
5263 
5264 static int
5265 rtld_verify_object_versions(Obj_Entry *obj)
5266 {
5267     const Elf_Verneed *vn;
5268     const Elf_Verdef  *vd;
5269     const Elf_Verdaux *vda;
5270     const Elf_Vernaux *vna;
5271     const Obj_Entry *depobj;
5272     int maxvernum, vernum;
5273 
5274     if (obj->ver_checked)
5275 	return (0);
5276     obj->ver_checked = true;
5277 
5278     maxvernum = 0;
5279     /*
5280      * Walk over defined and required version records and figure out
5281      * max index used by any of them. Do very basic sanity checking
5282      * while there.
5283      */
5284     vn = obj->verneed;
5285     while (vn != NULL) {
5286 	if (vn->vn_version != VER_NEED_CURRENT) {
5287 	    _rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
5288 		obj->path, vn->vn_version);
5289 	    return (-1);
5290 	}
5291 	vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux);
5292 	for (;;) {
5293 	    vernum = VER_NEED_IDX(vna->vna_other);
5294 	    if (vernum > maxvernum)
5295 		maxvernum = vernum;
5296 	    if (vna->vna_next == 0)
5297 		 break;
5298 	    vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next);
5299 	}
5300 	if (vn->vn_next == 0)
5301 	    break;
5302 	vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next);
5303     }
5304 
5305     vd = obj->verdef;
5306     while (vd != NULL) {
5307 	if (vd->vd_version != VER_DEF_CURRENT) {
5308 	    _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
5309 		obj->path, vd->vd_version);
5310 	    return (-1);
5311 	}
5312 	vernum = VER_DEF_IDX(vd->vd_ndx);
5313 	if (vernum > maxvernum)
5314 		maxvernum = vernum;
5315 	if (vd->vd_next == 0)
5316 	    break;
5317 	vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next);
5318     }
5319 
5320     if (maxvernum == 0)
5321 	return (0);
5322 
5323     /*
5324      * Store version information in array indexable by version index.
5325      * Verify that object version requirements are satisfied along the
5326      * way.
5327      */
5328     obj->vernum = maxvernum + 1;
5329     obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry));
5330 
5331     vd = obj->verdef;
5332     while (vd != NULL) {
5333 	if ((vd->vd_flags & VER_FLG_BASE) == 0) {
5334 	    vernum = VER_DEF_IDX(vd->vd_ndx);
5335 	    assert(vernum <= maxvernum);
5336 	    vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux);
5337 	    obj->vertab[vernum].hash = vd->vd_hash;
5338 	    obj->vertab[vernum].name = obj->strtab + vda->vda_name;
5339 	    obj->vertab[vernum].file = NULL;
5340 	    obj->vertab[vernum].flags = 0;
5341 	}
5342 	if (vd->vd_next == 0)
5343 	    break;
5344 	vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next);
5345     }
5346 
5347     vn = obj->verneed;
5348     while (vn != NULL) {
5349 	depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
5350 	if (depobj == NULL)
5351 	    return (-1);
5352 	vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux);
5353 	for (;;) {
5354 	    if (check_object_provided_version(obj, depobj, vna))
5355 		return (-1);
5356 	    vernum = VER_NEED_IDX(vna->vna_other);
5357 	    assert(vernum <= maxvernum);
5358 	    obj->vertab[vernum].hash = vna->vna_hash;
5359 	    obj->vertab[vernum].name = obj->strtab + vna->vna_name;
5360 	    obj->vertab[vernum].file = obj->strtab + vn->vn_file;
5361 	    obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ?
5362 		VER_INFO_HIDDEN : 0;
5363 	    if (vna->vna_next == 0)
5364 		 break;
5365 	    vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next);
5366 	}
5367 	if (vn->vn_next == 0)
5368 	    break;
5369 	vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next);
5370     }
5371     return 0;
5372 }
5373 
5374 static int
5375 rtld_verify_versions(const Objlist *objlist)
5376 {
5377     Objlist_Entry *entry;
5378     int rc;
5379 
5380     rc = 0;
5381     STAILQ_FOREACH(entry, objlist, link) {
5382 	/*
5383 	 * Skip dummy objects or objects that have their version requirements
5384 	 * already checked.
5385 	 */
5386 	if (entry->obj->strtab == NULL || entry->obj->vertab != NULL)
5387 	    continue;
5388 	if (rtld_verify_object_versions(entry->obj) == -1) {
5389 	    rc = -1;
5390 	    if (ld_tracing == NULL)
5391 		break;
5392 	}
5393     }
5394     if (rc == 0 || ld_tracing != NULL)
5395     	rc = rtld_verify_object_versions(&obj_rtld);
5396     return rc;
5397 }
5398 
5399 const Ver_Entry *
5400 fetch_ventry(const Obj_Entry *obj, unsigned long symnum)
5401 {
5402     Elf_Versym vernum;
5403 
5404     if (obj->vertab) {
5405 	vernum = VER_NDX(obj->versyms[symnum]);
5406 	if (vernum >= obj->vernum) {
5407 	    _rtld_error("%s: symbol %s has wrong verneed value %d",
5408 		obj->path, obj->strtab + symnum, vernum);
5409 	} else if (obj->vertab[vernum].hash != 0) {
5410 	    return &obj->vertab[vernum];
5411 	}
5412     }
5413     return NULL;
5414 }
5415 
5416 int
5417 _rtld_get_stack_prot(void)
5418 {
5419 
5420 	return (stack_prot);
5421 }
5422 
5423 int
5424 _rtld_is_dlopened(void *arg)
5425 {
5426 	Obj_Entry *obj;
5427 	RtldLockState lockstate;
5428 	int res;
5429 
5430 	rlock_acquire(rtld_bind_lock, &lockstate);
5431 	obj = dlcheck(arg);
5432 	if (obj == NULL)
5433 		obj = obj_from_addr(arg);
5434 	if (obj == NULL) {
5435 		_rtld_error("No shared object contains address");
5436 		lock_release(rtld_bind_lock, &lockstate);
5437 		return (-1);
5438 	}
5439 	res = obj->dlopened ? 1 : 0;
5440 	lock_release(rtld_bind_lock, &lockstate);
5441 	return (res);
5442 }
5443 
5444 static int
5445 obj_remap_relro(Obj_Entry *obj, int prot)
5446 {
5447 
5448 	if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size,
5449 	    prot) == -1) {
5450 		_rtld_error("%s: Cannot set relro protection to %#x: %s",
5451 		    obj->path, prot, rtld_strerror(errno));
5452 		return (-1);
5453 	}
5454 	return (0);
5455 }
5456 
5457 static int
5458 obj_disable_relro(Obj_Entry *obj)
5459 {
5460 
5461 	return (obj_remap_relro(obj, PROT_READ | PROT_WRITE));
5462 }
5463 
5464 static int
5465 obj_enforce_relro(Obj_Entry *obj)
5466 {
5467 
5468 	return (obj_remap_relro(obj, PROT_READ));
5469 }
5470 
5471 static void
5472 map_stacks_exec(RtldLockState *lockstate)
5473 {
5474 	void (*thr_map_stacks_exec)(void);
5475 
5476 	if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0)
5477 		return;
5478 	thr_map_stacks_exec = (void (*)(void))(uintptr_t)
5479 	    get_program_var_addr("__pthread_map_stacks_exec", lockstate);
5480 	if (thr_map_stacks_exec != NULL) {
5481 		stack_prot |= PROT_EXEC;
5482 		thr_map_stacks_exec();
5483 	}
5484 }
5485 
5486 static void
5487 distribute_static_tls(Objlist *list, RtldLockState *lockstate)
5488 {
5489 	Objlist_Entry *elm;
5490 	Obj_Entry *obj;
5491 	void (*distrib)(size_t, void *, size_t, size_t);
5492 
5493 	distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t)
5494 	    get_program_var_addr("__pthread_distribute_static_tls", lockstate);
5495 	if (distrib == NULL)
5496 		return;
5497 	STAILQ_FOREACH(elm, list, link) {
5498 		obj = elm->obj;
5499 		if (obj->marker || !obj->tls_done || obj->static_tls_copied)
5500 			continue;
5501 		distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize,
5502 		    obj->tlssize);
5503 		obj->static_tls_copied = true;
5504 	}
5505 }
5506 
5507 void
5508 symlook_init(SymLook *dst, const char *name)
5509 {
5510 
5511 	bzero(dst, sizeof(*dst));
5512 	dst->name = name;
5513 	dst->hash = elf_hash(name);
5514 	dst->hash_gnu = gnu_hash(name);
5515 }
5516 
5517 static void
5518 symlook_init_from_req(SymLook *dst, const SymLook *src)
5519 {
5520 
5521 	dst->name = src->name;
5522 	dst->hash = src->hash;
5523 	dst->hash_gnu = src->hash_gnu;
5524 	dst->ventry = src->ventry;
5525 	dst->flags = src->flags;
5526 	dst->defobj_out = NULL;
5527 	dst->sym_out = NULL;
5528 	dst->lockstate = src->lockstate;
5529 }
5530 
5531 static int
5532 open_binary_fd(const char *argv0, bool search_in_path,
5533     const char **binpath_res)
5534 {
5535 	char *binpath, *pathenv, *pe, *res1;
5536 	const char *res;
5537 	int fd;
5538 
5539 	binpath = NULL;
5540 	res = NULL;
5541 	if (search_in_path && strchr(argv0, '/') == NULL) {
5542 		binpath = xmalloc(PATH_MAX);
5543 		pathenv = getenv("PATH");
5544 		if (pathenv == NULL) {
5545 			_rtld_error("-p and no PATH environment variable");
5546 			rtld_die();
5547 		}
5548 		pathenv = strdup(pathenv);
5549 		if (pathenv == NULL) {
5550 			_rtld_error("Cannot allocate memory");
5551 			rtld_die();
5552 		}
5553 		fd = -1;
5554 		errno = ENOENT;
5555 		while ((pe = strsep(&pathenv, ":")) != NULL) {
5556 			if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX)
5557 				continue;
5558 			if (binpath[0] != '\0' &&
5559 			    strlcat(binpath, "/", PATH_MAX) >= PATH_MAX)
5560 				continue;
5561 			if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX)
5562 				continue;
5563 			fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY);
5564 			if (fd != -1 || errno != ENOENT) {
5565 				res = binpath;
5566 				break;
5567 			}
5568 		}
5569 		free(pathenv);
5570 	} else {
5571 		fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY);
5572 		res = argv0;
5573 	}
5574 
5575 	if (fd == -1) {
5576 		_rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno));
5577 		rtld_die();
5578 	}
5579 	if (res != NULL && res[0] != '/') {
5580 		res1 = xmalloc(PATH_MAX);
5581 		if (realpath(res, res1) != NULL) {
5582 			if (res != argv0)
5583 				free(__DECONST(char *, res));
5584 			res = res1;
5585 		} else {
5586 			free(res1);
5587 		}
5588 	}
5589 	*binpath_res = res;
5590 	return (fd);
5591 }
5592 
5593 /*
5594  * Parse a set of command-line arguments.
5595  */
5596 static int
5597 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp)
5598 {
5599 	const char *arg;
5600 	int fd, i, j, arglen;
5601 	char opt;
5602 
5603 	dbg("Parsing command-line arguments");
5604 	*use_pathp = false;
5605 	*fdp = -1;
5606 
5607 	for (i = 1; i < argc; i++ ) {
5608 		arg = argv[i];
5609 		dbg("argv[%d]: '%s'", i, arg);
5610 
5611 		/*
5612 		 * rtld arguments end with an explicit "--" or with the first
5613 		 * non-prefixed argument.
5614 		 */
5615 		if (strcmp(arg, "--") == 0) {
5616 			i++;
5617 			break;
5618 		}
5619 		if (arg[0] != '-')
5620 			break;
5621 
5622 		/*
5623 		 * All other arguments are single-character options that can
5624 		 * be combined, so we need to search through `arg` for them.
5625 		 */
5626 		arglen = strlen(arg);
5627 		for (j = 1; j < arglen; j++) {
5628 			opt = arg[j];
5629 			if (opt == 'h') {
5630 				print_usage(argv[0]);
5631 				_exit(0);
5632 			} else if (opt == 'f') {
5633 				/*
5634 				 * -f XX can be used to specify a
5635 				 * descriptor for the binary named at
5636 				 * the command line (i.e., the later
5637 				 * argument will specify the process
5638 				 * name but the descriptor is what
5639 				 * will actually be executed).
5640 				 *
5641 				 * -f must be the last option in, e.g., -abcf.
5642 				 */
5643 				if (j != arglen - 1) {
5644 					_rtld_error("Invalid options: %s", arg);
5645 					rtld_die();
5646 				}
5647 				i++;
5648 				fd = parse_integer(argv[i]);
5649 				if (fd == -1) {
5650 					_rtld_error(
5651 					    "Invalid file descriptor: '%s'",
5652 					    argv[i]);
5653 					rtld_die();
5654 				}
5655 				*fdp = fd;
5656 				break;
5657 			} else if (opt == 'p') {
5658 				*use_pathp = true;
5659 			} else {
5660 				_rtld_error("Invalid argument: '%s'", arg);
5661 				print_usage(argv[0]);
5662 				rtld_die();
5663 			}
5664 		}
5665 	}
5666 
5667 	return (i);
5668 }
5669 
5670 /*
5671  * Parse a file descriptor number without pulling in more of libc (e.g. atoi).
5672  */
5673 static int
5674 parse_integer(const char *str)
5675 {
5676 	static const int RADIX = 10;  /* XXXJA: possibly support hex? */
5677 	const char *orig;
5678 	int n;
5679 	char c;
5680 
5681 	orig = str;
5682 	n = 0;
5683 	for (c = *str; c != '\0'; c = *++str) {
5684 		if (c < '0' || c > '9')
5685 			return (-1);
5686 
5687 		n *= RADIX;
5688 		n += c - '0';
5689 	}
5690 
5691 	/* Make sure we actually parsed something. */
5692 	if (str == orig)
5693 		return (-1);
5694 	return (n);
5695 }
5696 
5697 static void
5698 print_usage(const char *argv0)
5699 {
5700 
5701 	rtld_printf("Usage: %s [-h] [-f <FD>] [--] <binary> [<args>]\n"
5702 		"\n"
5703 		"Options:\n"
5704 		"  -h        Display this help message\n"
5705 		"  -p        Search in PATH for named binary\n"
5706 		"  -f <FD>   Execute <FD> instead of searching for <binary>\n"
5707 		"  --        End of RTLD options\n"
5708 		"  <binary>  Name of process to execute\n"
5709 		"  <args>    Arguments to the executed process\n", argv0);
5710 }
5711 
5712 /*
5713  * Overrides for libc_pic-provided functions.
5714  */
5715 
5716 int
5717 __getosreldate(void)
5718 {
5719 	size_t len;
5720 	int oid[2];
5721 	int error, osrel;
5722 
5723 	if (osreldate != 0)
5724 		return (osreldate);
5725 
5726 	oid[0] = CTL_KERN;
5727 	oid[1] = KERN_OSRELDATE;
5728 	osrel = 0;
5729 	len = sizeof(osrel);
5730 	error = sysctl(oid, 2, &osrel, &len, NULL, 0);
5731 	if (error == 0 && osrel > 0 && len == sizeof(osrel))
5732 		osreldate = osrel;
5733 	return (osreldate);
5734 }
5735 const char *
5736 rtld_strerror(int errnum)
5737 {
5738 
5739 	if (errnum < 0 || errnum >= sys_nerr)
5740 		return ("Unknown error");
5741 	return (sys_errlist[errnum]);
5742 }
5743 
5744 /* malloc */
5745 void *
5746 malloc(size_t nbytes)
5747 {
5748 
5749 	return (__crt_malloc(nbytes));
5750 }
5751 
5752 void *
5753 calloc(size_t num, size_t size)
5754 {
5755 
5756 	return (__crt_calloc(num, size));
5757 }
5758 
5759 void
5760 free(void *cp)
5761 {
5762 
5763 	__crt_free(cp);
5764 }
5765 
5766 void *
5767 realloc(void *cp, size_t nbytes)
5768 {
5769 
5770 	return (__crt_realloc(cp, nbytes));
5771 }
5772