rtld.c revision 276908
1/*-
2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
3 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>.
4 * Copyright 2009-2012 Konstantin Belousov <kib@FreeBSD.ORG>.
5 * Copyright 2012 John Marino <draco@marino.st>.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD: stable/10/libexec/rtld-elf/rtld.c 276908 2015-01-10 09:22:17Z kib $
29 */
30
31/*
32 * Dynamic linker for ELF.
33 *
34 * John Polstra <jdp@polstra.com>.
35 */
36
37#ifndef __GNUC__
38#error "GCC is needed to compile this file"
39#endif
40
41#include <sys/param.h>
42#include <sys/mount.h>
43#include <sys/mman.h>
44#include <sys/stat.h>
45#include <sys/sysctl.h>
46#include <sys/uio.h>
47#include <sys/utsname.h>
48#include <sys/ktrace.h>
49
50#include <dlfcn.h>
51#include <err.h>
52#include <errno.h>
53#include <fcntl.h>
54#include <stdarg.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <unistd.h>
59
60#include "debug.h"
61#include "rtld.h"
62#include "libmap.h"
63#include "rtld_tls.h"
64#include "rtld_printf.h"
65#include "notes.h"
66
67#ifndef COMPAT_32BIT
68#define PATH_RTLD	"/libexec/ld-elf.so.1"
69#else
70#define PATH_RTLD	"/libexec/ld-elf32.so.1"
71#endif
72
73/* Types. */
74typedef void (*func_ptr_type)();
75typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
76
77/*
78 * Function declarations.
79 */
80static const char *basename(const char *);
81static void die(void) __dead2;
82static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
83    const Elf_Dyn **, const Elf_Dyn **);
84static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *,
85    const Elf_Dyn *);
86static void digest_dynamic(Obj_Entry *, int);
87static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
88static Obj_Entry *dlcheck(void *);
89static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj,
90    int lo_flags, int mode, RtldLockState *lockstate);
91static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
92static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
93static bool donelist_check(DoneList *, const Obj_Entry *);
94static void errmsg_restore(char *);
95static char *errmsg_save(void);
96static void *fill_search_info(const char *, size_t, void *);
97static char *find_library(const char *, const Obj_Entry *);
98static const char *gethints(bool);
99static void init_dag(Obj_Entry *);
100static void init_rtld(caddr_t, Elf_Auxinfo **);
101static void initlist_add_neededs(Needed_Entry *, Objlist *);
102static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
103static void linkmap_add(Obj_Entry *);
104static void linkmap_delete(Obj_Entry *);
105static void load_filtees(Obj_Entry *, int flags, RtldLockState *);
106static void unload_filtees(Obj_Entry *);
107static int load_needed_objects(Obj_Entry *, int);
108static int load_preload_objects(void);
109static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int);
110static void map_stacks_exec(RtldLockState *);
111static Obj_Entry *obj_from_addr(const void *);
112static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
113static void objlist_call_init(Objlist *, RtldLockState *);
114static void objlist_clear(Objlist *);
115static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
116static void objlist_init(Objlist *);
117static void objlist_push_head(Objlist *, Obj_Entry *);
118static void objlist_push_tail(Objlist *, Obj_Entry *);
119static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *);
120static void objlist_remove(Objlist *, Obj_Entry *);
121static void *path_enumerate(const char *, path_enum_proc, void *);
122static int relocate_object_dag(Obj_Entry *root, bool bind_now,
123    Obj_Entry *rtldobj, int flags, RtldLockState *lockstate);
124static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
125    int flags, RtldLockState *lockstate);
126static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int,
127    RtldLockState *);
128static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now,
129    int flags, RtldLockState *lockstate);
130static int rtld_dirname(const char *, char *);
131static int rtld_dirname_abs(const char *, char *);
132static void *rtld_dlopen(const char *name, int fd, int mode);
133static void rtld_exit(void);
134static char *search_library_path(const char *, const char *);
135static const void **get_program_var_addr(const char *, RtldLockState *);
136static void set_program_var(const char *, const void *);
137static int symlook_default(SymLook *, const Obj_Entry *refobj);
138static int symlook_global(SymLook *, DoneList *);
139static void symlook_init_from_req(SymLook *, const SymLook *);
140static int symlook_list(SymLook *, const Objlist *, DoneList *);
141static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *);
142static int symlook_obj1_sysv(SymLook *, const Obj_Entry *);
143static int symlook_obj1_gnu(SymLook *, const Obj_Entry *);
144static void trace_loaded_objects(Obj_Entry *);
145static void unlink_object(Obj_Entry *);
146static void unload_object(Obj_Entry *);
147static void unref_dag(Obj_Entry *);
148static void ref_dag(Obj_Entry *);
149static char *origin_subst_one(char *, const char *, const char *, bool);
150static char *origin_subst(char *, const char *);
151static void preinit_main(void);
152static int  rtld_verify_versions(const Objlist *);
153static int  rtld_verify_object_versions(Obj_Entry *);
154static void object_add_name(Obj_Entry *, const char *);
155static int  object_match_name(const Obj_Entry *, const char *);
156static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
157static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
158    struct dl_phdr_info *phdr_info);
159static uint32_t gnu_hash(const char *);
160static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *,
161    const unsigned long);
162
163void r_debug_state(struct r_debug *, struct link_map *) __noinline;
164void _r_debug_postinit(struct link_map *) __noinline;
165
166/*
167 * Data declarations.
168 */
169static char *error_message;	/* Message for dlerror(), or NULL */
170struct r_debug r_debug;		/* for GDB; */
171static bool libmap_disable;	/* Disable libmap */
172static bool ld_loadfltr;	/* Immediate filters processing */
173static char *libmap_override;	/* Maps to use in addition to libmap.conf */
174static bool trust;		/* False for setuid and setgid programs */
175static bool dangerous_ld_env;	/* True if environment variables have been
176				   used to affect the libraries loaded */
177static char *ld_bind_now;	/* Environment variable for immediate binding */
178static char *ld_debug;		/* Environment variable for debugging */
179static char *ld_library_path;	/* Environment variable for search path */
180static char *ld_preload;	/* Environment variable for libraries to
181				   load first */
182static char *ld_elf_hints_path;	/* Environment variable for alternative hints path */
183static char *ld_tracing;	/* Called from ldd to print libs */
184static char *ld_utrace;		/* Use utrace() to log events. */
185static Obj_Entry *obj_list;	/* Head of linked list of shared objects */
186static Obj_Entry **obj_tail;	/* Link field of last object in list */
187static Obj_Entry *obj_main;	/* The main program shared object */
188static Obj_Entry obj_rtld;	/* The dynamic linker shared object */
189static unsigned int obj_count;	/* Number of objects in obj_list */
190static unsigned int obj_loads;	/* Number of objects in obj_list */
191
192static Objlist list_global =	/* Objects dlopened with RTLD_GLOBAL */
193  STAILQ_HEAD_INITIALIZER(list_global);
194static Objlist list_main =	/* Objects loaded at program startup */
195  STAILQ_HEAD_INITIALIZER(list_main);
196static Objlist list_fini =	/* Objects needing fini() calls */
197  STAILQ_HEAD_INITIALIZER(list_fini);
198
199Elf_Sym sym_zero;		/* For resolving undefined weak refs. */
200
201#define GDB_STATE(s,m)	r_debug.r_state = s; r_debug_state(&r_debug,m);
202
203extern Elf_Dyn _DYNAMIC;
204#pragma weak _DYNAMIC
205#ifndef RTLD_IS_DYNAMIC
206#define	RTLD_IS_DYNAMIC()	(&_DYNAMIC != NULL)
207#endif
208
209int osreldate, pagesize;
210
211long __stack_chk_guard[8] = {0, 0, 0, 0, 0, 0, 0, 0};
212
213static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC;
214static int max_stack_flags;
215
216/*
217 * Global declarations normally provided by crt1.  The dynamic linker is
218 * not built with crt1, so we have to provide them ourselves.
219 */
220char *__progname;
221char **environ;
222
223/*
224 * Used to pass argc, argv to init functions.
225 */
226int main_argc;
227char **main_argv;
228
229/*
230 * Globals to control TLS allocation.
231 */
232size_t tls_last_offset;		/* Static TLS offset of last module */
233size_t tls_last_size;		/* Static TLS size of last module */
234size_t tls_static_space;	/* Static TLS space allocated */
235size_t tls_static_max_align;
236int tls_dtv_generation = 1;	/* Used to detect when dtv size changes  */
237int tls_max_index = 1;		/* Largest module index allocated */
238
239bool ld_library_path_rpath = false;
240
241/*
242 * Fill in a DoneList with an allocation large enough to hold all of
243 * the currently-loaded objects.  Keep this as a macro since it calls
244 * alloca and we want that to occur within the scope of the caller.
245 */
246#define donelist_init(dlp)					\
247    ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]),	\
248    assert((dlp)->objs != NULL),				\
249    (dlp)->num_alloc = obj_count,				\
250    (dlp)->num_used = 0)
251
252#define	UTRACE_DLOPEN_START		1
253#define	UTRACE_DLOPEN_STOP		2
254#define	UTRACE_DLCLOSE_START		3
255#define	UTRACE_DLCLOSE_STOP		4
256#define	UTRACE_LOAD_OBJECT		5
257#define	UTRACE_UNLOAD_OBJECT		6
258#define	UTRACE_ADD_RUNDEP		7
259#define	UTRACE_PRELOAD_FINISHED		8
260#define	UTRACE_INIT_CALL		9
261#define	UTRACE_FINI_CALL		10
262
263struct utrace_rtld {
264	char sig[4];			/* 'RTLD' */
265	int event;
266	void *handle;
267	void *mapbase;			/* Used for 'parent' and 'init/fini' */
268	size_t mapsize;
269	int refcnt;			/* Used for 'mode' */
270	char name[MAXPATHLEN];
271};
272
273#define	LD_UTRACE(e, h, mb, ms, r, n) do {			\
274	if (ld_utrace != NULL)					\
275		ld_utrace_log(e, h, mb, ms, r, n);		\
276} while (0)
277
278static void
279ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
280    int refcnt, const char *name)
281{
282	struct utrace_rtld ut;
283
284	ut.sig[0] = 'R';
285	ut.sig[1] = 'T';
286	ut.sig[2] = 'L';
287	ut.sig[3] = 'D';
288	ut.event = event;
289	ut.handle = handle;
290	ut.mapbase = mapbase;
291	ut.mapsize = mapsize;
292	ut.refcnt = refcnt;
293	bzero(ut.name, sizeof(ut.name));
294	if (name)
295		strlcpy(ut.name, name, sizeof(ut.name));
296	utrace(&ut, sizeof(ut));
297}
298
299/*
300 * Main entry point for dynamic linking.  The first argument is the
301 * stack pointer.  The stack is expected to be laid out as described
302 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
303 * Specifically, the stack pointer points to a word containing
304 * ARGC.  Following that in the stack is a null-terminated sequence
305 * of pointers to argument strings.  Then comes a null-terminated
306 * sequence of pointers to environment strings.  Finally, there is a
307 * sequence of "auxiliary vector" entries.
308 *
309 * The second argument points to a place to store the dynamic linker's
310 * exit procedure pointer and the third to a place to store the main
311 * program's object.
312 *
313 * The return value is the main program's entry point.
314 */
315func_ptr_type
316_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
317{
318    Elf_Auxinfo *aux_info[AT_COUNT];
319    int i;
320    int argc;
321    char **argv;
322    char **env;
323    Elf_Auxinfo *aux;
324    Elf_Auxinfo *auxp;
325    const char *argv0;
326    Objlist_Entry *entry;
327    Obj_Entry *obj;
328    Obj_Entry **preload_tail;
329    Obj_Entry *last_interposer;
330    Objlist initlist;
331    RtldLockState lockstate;
332    char *library_path_rpath;
333    int mib[2];
334    size_t len;
335
336    /*
337     * On entry, the dynamic linker itself has not been relocated yet.
338     * Be very careful not to reference any global data until after
339     * init_rtld has returned.  It is OK to reference file-scope statics
340     * and string constants, and to call static and global functions.
341     */
342
343    /* Find the auxiliary vector on the stack. */
344    argc = *sp++;
345    argv = (char **) sp;
346    sp += argc + 1;	/* Skip over arguments and NULL terminator */
347    env = (char **) sp;
348    while (*sp++ != 0)	/* Skip over environment, and NULL terminator */
349	;
350    aux = (Elf_Auxinfo *) sp;
351
352    /* Digest the auxiliary vector. */
353    for (i = 0;  i < AT_COUNT;  i++)
354	aux_info[i] = NULL;
355    for (auxp = aux;  auxp->a_type != AT_NULL;  auxp++) {
356	if (auxp->a_type < AT_COUNT)
357	    aux_info[auxp->a_type] = auxp;
358    }
359
360    /* Initialize and relocate ourselves. */
361    assert(aux_info[AT_BASE] != NULL);
362    init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
363
364    __progname = obj_rtld.path;
365    argv0 = argv[0] != NULL ? argv[0] : "(null)";
366    environ = env;
367    main_argc = argc;
368    main_argv = argv;
369
370    if (aux_info[AT_CANARY] != NULL &&
371	aux_info[AT_CANARY]->a_un.a_ptr != NULL) {
372	    i = aux_info[AT_CANARYLEN]->a_un.a_val;
373	    if (i > sizeof(__stack_chk_guard))
374		    i = sizeof(__stack_chk_guard);
375	    memcpy(__stack_chk_guard, aux_info[AT_CANARY]->a_un.a_ptr, i);
376    } else {
377	mib[0] = CTL_KERN;
378	mib[1] = KERN_ARND;
379
380	len = sizeof(__stack_chk_guard);
381	if (sysctl(mib, 2, __stack_chk_guard, &len, NULL, 0) == -1 ||
382	    len != sizeof(__stack_chk_guard)) {
383		/* If sysctl was unsuccessful, use the "terminator canary". */
384		((unsigned char *)(void *)__stack_chk_guard)[0] = 0;
385		((unsigned char *)(void *)__stack_chk_guard)[1] = 0;
386		((unsigned char *)(void *)__stack_chk_guard)[2] = '\n';
387		((unsigned char *)(void *)__stack_chk_guard)[3] = 255;
388	}
389    }
390
391    trust = !issetugid();
392
393    ld_bind_now = getenv(LD_ "BIND_NOW");
394    /*
395     * If the process is tainted, then we un-set the dangerous environment
396     * variables.  The process will be marked as tainted until setuid(2)
397     * is called.  If any child process calls setuid(2) we do not want any
398     * future processes to honor the potentially un-safe variables.
399     */
400    if (!trust) {
401        if (unsetenv(LD_ "PRELOAD") || unsetenv(LD_ "LIBMAP") ||
402	    unsetenv(LD_ "LIBRARY_PATH") || unsetenv(LD_ "LIBMAP_DISABLE") ||
403	    unsetenv(LD_ "DEBUG") || unsetenv(LD_ "ELF_HINTS_PATH") ||
404	    unsetenv(LD_ "LOADFLTR") || unsetenv(LD_ "LIBRARY_PATH_RPATH")) {
405		_rtld_error("environment corrupt; aborting");
406		die();
407	}
408    }
409    ld_debug = getenv(LD_ "DEBUG");
410    libmap_disable = getenv(LD_ "LIBMAP_DISABLE") != NULL;
411    libmap_override = getenv(LD_ "LIBMAP");
412    ld_library_path = getenv(LD_ "LIBRARY_PATH");
413    ld_preload = getenv(LD_ "PRELOAD");
414    ld_elf_hints_path = getenv(LD_ "ELF_HINTS_PATH");
415    ld_loadfltr = getenv(LD_ "LOADFLTR") != NULL;
416    library_path_rpath = getenv(LD_ "LIBRARY_PATH_RPATH");
417    if (library_path_rpath != NULL) {
418	    if (library_path_rpath[0] == 'y' ||
419		library_path_rpath[0] == 'Y' ||
420		library_path_rpath[0] == '1')
421		    ld_library_path_rpath = true;
422	    else
423		    ld_library_path_rpath = false;
424    }
425    dangerous_ld_env = libmap_disable || (libmap_override != NULL) ||
426	(ld_library_path != NULL) || (ld_preload != NULL) ||
427	(ld_elf_hints_path != NULL) || ld_loadfltr;
428    ld_tracing = getenv(LD_ "TRACE_LOADED_OBJECTS");
429    ld_utrace = getenv(LD_ "UTRACE");
430
431    if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
432	ld_elf_hints_path = _PATH_ELF_HINTS;
433
434    if (ld_debug != NULL && *ld_debug != '\0')
435	debug = 1;
436    dbg("%s is initialized, base address = %p", __progname,
437	(caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
438    dbg("RTLD dynamic = %p", obj_rtld.dynamic);
439    dbg("RTLD pltgot  = %p", obj_rtld.pltgot);
440
441    dbg("initializing thread locks");
442    lockdflt_init();
443
444    /*
445     * Load the main program, or process its program header if it is
446     * already loaded.
447     */
448    if (aux_info[AT_EXECFD] != NULL) {	/* Load the main program. */
449	int fd = aux_info[AT_EXECFD]->a_un.a_val;
450	dbg("loading main program");
451	obj_main = map_object(fd, argv0, NULL);
452	close(fd);
453	if (obj_main == NULL)
454	    die();
455	max_stack_flags = obj->stack_flags;
456    } else {				/* Main program already loaded. */
457	const Elf_Phdr *phdr;
458	int phnum;
459	caddr_t entry;
460
461	dbg("processing main program's program header");
462	assert(aux_info[AT_PHDR] != NULL);
463	phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
464	assert(aux_info[AT_PHNUM] != NULL);
465	phnum = aux_info[AT_PHNUM]->a_un.a_val;
466	assert(aux_info[AT_PHENT] != NULL);
467	assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
468	assert(aux_info[AT_ENTRY] != NULL);
469	entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
470	if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
471	    die();
472    }
473
474    if (aux_info[AT_EXECPATH] != 0) {
475	    char *kexecpath;
476	    char buf[MAXPATHLEN];
477
478	    kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
479	    dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
480	    if (kexecpath[0] == '/')
481		    obj_main->path = kexecpath;
482	    else if (getcwd(buf, sizeof(buf)) == NULL ||
483		     strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
484		     strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
485		    obj_main->path = xstrdup(argv0);
486	    else
487		    obj_main->path = xstrdup(buf);
488    } else {
489	    dbg("No AT_EXECPATH");
490	    obj_main->path = xstrdup(argv0);
491    }
492    dbg("obj_main path %s", obj_main->path);
493    obj_main->mainprog = true;
494
495    if (aux_info[AT_STACKPROT] != NULL &&
496      aux_info[AT_STACKPROT]->a_un.a_val != 0)
497	    stack_prot = aux_info[AT_STACKPROT]->a_un.a_val;
498
499    /*
500     * Get the actual dynamic linker pathname from the executable if
501     * possible.  (It should always be possible.)  That ensures that
502     * gdb will find the right dynamic linker even if a non-standard
503     * one is being used.
504     */
505    if (obj_main->interp != NULL &&
506      strcmp(obj_main->interp, obj_rtld.path) != 0) {
507	free(obj_rtld.path);
508	obj_rtld.path = xstrdup(obj_main->interp);
509        __progname = obj_rtld.path;
510    }
511
512    digest_dynamic(obj_main, 0);
513    dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d",
514	obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu,
515	obj_main->dynsymcount);
516
517    linkmap_add(obj_main);
518    linkmap_add(&obj_rtld);
519
520    /* Link the main program into the list of objects. */
521    *obj_tail = obj_main;
522    obj_tail = &obj_main->next;
523    obj_count++;
524    obj_loads++;
525
526    /* Initialize a fake symbol for resolving undefined weak references. */
527    sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
528    sym_zero.st_shndx = SHN_UNDEF;
529    sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
530
531    if (!libmap_disable)
532        libmap_disable = (bool)lm_init(libmap_override);
533
534    dbg("loading LD_PRELOAD libraries");
535    if (load_preload_objects() == -1)
536	die();
537    preload_tail = obj_tail;
538
539    dbg("loading needed objects");
540    if (load_needed_objects(obj_main, 0) == -1)
541	die();
542
543    /* Make a list of all objects loaded at startup. */
544    last_interposer = obj_main;
545    for (obj = obj_list;  obj != NULL;  obj = obj->next) {
546	if (obj->z_interpose && obj != obj_main) {
547	    objlist_put_after(&list_main, last_interposer, obj);
548	    last_interposer = obj;
549	} else {
550	    objlist_push_tail(&list_main, obj);
551	}
552    	obj->refcount++;
553    }
554
555    dbg("checking for required versions");
556    if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
557	die();
558
559    if (ld_tracing) {		/* We're done */
560	trace_loaded_objects(obj_main);
561	exit(0);
562    }
563
564    if (getenv(LD_ "DUMP_REL_PRE") != NULL) {
565       dump_relocations(obj_main);
566       exit (0);
567    }
568
569    /*
570     * Processing tls relocations requires having the tls offsets
571     * initialized.  Prepare offsets before starting initial
572     * relocation processing.
573     */
574    dbg("initializing initial thread local storage offsets");
575    STAILQ_FOREACH(entry, &list_main, link) {
576	/*
577	 * Allocate all the initial objects out of the static TLS
578	 * block even if they didn't ask for it.
579	 */
580	allocate_tls_offset(entry->obj);
581    }
582
583    if (relocate_objects(obj_main,
584      ld_bind_now != NULL && *ld_bind_now != '\0',
585      &obj_rtld, SYMLOOK_EARLY, NULL) == -1)
586	die();
587
588    dbg("doing copy relocations");
589    if (do_copy_relocations(obj_main) == -1)
590	die();
591
592    if (getenv(LD_ "DUMP_REL_POST") != NULL) {
593       dump_relocations(obj_main);
594       exit (0);
595    }
596
597    /*
598     * Setup TLS for main thread.  This must be done after the
599     * relocations are processed, since tls initialization section
600     * might be the subject for relocations.
601     */
602    dbg("initializing initial thread local storage");
603    allocate_initial_tls(obj_list);
604
605    dbg("initializing key program variables");
606    set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
607    set_program_var("environ", env);
608    set_program_var("__elf_aux_vector", aux);
609
610    /* Make a list of init functions to call. */
611    objlist_init(&initlist);
612    initlist_add_objects(obj_list, preload_tail, &initlist);
613
614    r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
615
616    map_stacks_exec(NULL);
617
618    dbg("resolving ifuncs");
619    if (resolve_objects_ifunc(obj_main,
620      ld_bind_now != NULL && *ld_bind_now != '\0', SYMLOOK_EARLY,
621      NULL) == -1)
622	die();
623
624    if (!obj_main->crt_no_init) {
625	/*
626	 * Make sure we don't call the main program's init and fini
627	 * functions for binaries linked with old crt1 which calls
628	 * _init itself.
629	 */
630	obj_main->init = obj_main->fini = (Elf_Addr)NULL;
631	obj_main->preinit_array = obj_main->init_array =
632	    obj_main->fini_array = (Elf_Addr)NULL;
633    }
634
635    wlock_acquire(rtld_bind_lock, &lockstate);
636    if (obj_main->crt_no_init)
637	preinit_main();
638    objlist_call_init(&initlist, &lockstate);
639    _r_debug_postinit(&obj_main->linkmap);
640    objlist_clear(&initlist);
641    dbg("loading filtees");
642    for (obj = obj_list->next; obj != NULL; obj = obj->next) {
643	if (ld_loadfltr || obj->z_loadfltr)
644	    load_filtees(obj, 0, &lockstate);
645    }
646    lock_release(rtld_bind_lock, &lockstate);
647
648    dbg("transferring control to program entry point = %p", obj_main->entry);
649
650    /* Return the exit procedure and the program entry point. */
651    *exit_proc = rtld_exit;
652    *objp = obj_main;
653    return (func_ptr_type) obj_main->entry;
654}
655
656void *
657rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def)
658{
659	void *ptr;
660	Elf_Addr target;
661
662	ptr = (void *)make_function_pointer(def, obj);
663	target = ((Elf_Addr (*)(void))ptr)();
664	return ((void *)target);
665}
666
667Elf_Addr
668_rtld_bind(Obj_Entry *obj, Elf_Size reloff)
669{
670    const Elf_Rel *rel;
671    const Elf_Sym *def;
672    const Obj_Entry *defobj;
673    Elf_Addr *where;
674    Elf_Addr target;
675    RtldLockState lockstate;
676
677    rlock_acquire(rtld_bind_lock, &lockstate);
678    if (sigsetjmp(lockstate.env, 0) != 0)
679	    lock_upgrade(rtld_bind_lock, &lockstate);
680    if (obj->pltrel)
681	rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
682    else
683	rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
684
685    where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
686    def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL,
687	&lockstate);
688    if (def == NULL)
689	die();
690    if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
691	target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
692    else
693	target = (Elf_Addr)(defobj->relocbase + def->st_value);
694
695    dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
696      defobj->strtab + def->st_name, basename(obj->path),
697      (void *)target, basename(defobj->path));
698
699    /*
700     * Write the new contents for the jmpslot. Note that depending on
701     * architecture, the value which we need to return back to the
702     * lazy binding trampoline may or may not be the target
703     * address. The value returned from reloc_jmpslot() is the value
704     * that the trampoline needs.
705     */
706    target = reloc_jmpslot(where, target, defobj, obj, rel);
707    lock_release(rtld_bind_lock, &lockstate);
708    return target;
709}
710
711/*
712 * Error reporting function.  Use it like printf.  If formats the message
713 * into a buffer, and sets things up so that the next call to dlerror()
714 * will return the message.
715 */
716void
717_rtld_error(const char *fmt, ...)
718{
719    static char buf[512];
720    va_list ap;
721
722    va_start(ap, fmt);
723    rtld_vsnprintf(buf, sizeof buf, fmt, ap);
724    error_message = buf;
725    va_end(ap);
726}
727
728/*
729 * Return a dynamically-allocated copy of the current error message, if any.
730 */
731static char *
732errmsg_save(void)
733{
734    return error_message == NULL ? NULL : xstrdup(error_message);
735}
736
737/*
738 * Restore the current error message from a copy which was previously saved
739 * by errmsg_save().  The copy is freed.
740 */
741static void
742errmsg_restore(char *saved_msg)
743{
744    if (saved_msg == NULL)
745	error_message = NULL;
746    else {
747	_rtld_error("%s", saved_msg);
748	free(saved_msg);
749    }
750}
751
752static const char *
753basename(const char *name)
754{
755    const char *p = strrchr(name, '/');
756    return p != NULL ? p + 1 : name;
757}
758
759static struct utsname uts;
760
761static char *
762origin_subst_one(char *real, const char *kw, const char *subst,
763    bool may_free)
764{
765	char *p, *p1, *res, *resp;
766	int subst_len, kw_len, subst_count, old_len, new_len;
767
768	kw_len = strlen(kw);
769
770	/*
771	 * First, count the number of the keyword occurences, to
772	 * preallocate the final string.
773	 */
774	for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) {
775		p1 = strstr(p, kw);
776		if (p1 == NULL)
777			break;
778	}
779
780	/*
781	 * If the keyword is not found, just return.
782	 */
783	if (subst_count == 0)
784		return (may_free ? real : xstrdup(real));
785
786	/*
787	 * There is indeed something to substitute.  Calculate the
788	 * length of the resulting string, and allocate it.
789	 */
790	subst_len = strlen(subst);
791	old_len = strlen(real);
792	new_len = old_len + (subst_len - kw_len) * subst_count;
793	res = xmalloc(new_len + 1);
794
795	/*
796	 * Now, execute the substitution loop.
797	 */
798	for (p = real, resp = res, *resp = '\0';;) {
799		p1 = strstr(p, kw);
800		if (p1 != NULL) {
801			/* Copy the prefix before keyword. */
802			memcpy(resp, p, p1 - p);
803			resp += p1 - p;
804			/* Keyword replacement. */
805			memcpy(resp, subst, subst_len);
806			resp += subst_len;
807			*resp = '\0';
808			p = p1 + kw_len;
809		} else
810			break;
811	}
812
813	/* Copy to the end of string and finish. */
814	strcat(resp, p);
815	if (may_free)
816		free(real);
817	return (res);
818}
819
820static char *
821origin_subst(char *real, const char *origin_path)
822{
823	char *res1, *res2, *res3, *res4;
824
825	if (uts.sysname[0] == '\0') {
826		if (uname(&uts) != 0) {
827			_rtld_error("utsname failed: %d", errno);
828			return (NULL);
829		}
830	}
831	res1 = origin_subst_one(real, "$ORIGIN", origin_path, false);
832	res2 = origin_subst_one(res1, "$OSNAME", uts.sysname, true);
833	res3 = origin_subst_one(res2, "$OSREL", uts.release, true);
834	res4 = origin_subst_one(res3, "$PLATFORM", uts.machine, true);
835	return (res4);
836}
837
838static void
839die(void)
840{
841    const char *msg = dlerror();
842
843    if (msg == NULL)
844	msg = "Fatal error";
845    rtld_fdputstr(STDERR_FILENO, msg);
846    rtld_fdputchar(STDERR_FILENO, '\n');
847    _exit(1);
848}
849
850/*
851 * Process a shared object's DYNAMIC section, and save the important
852 * information in its Obj_Entry structure.
853 */
854static void
855digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
856    const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath)
857{
858    const Elf_Dyn *dynp;
859    Needed_Entry **needed_tail = &obj->needed;
860    Needed_Entry **needed_filtees_tail = &obj->needed_filtees;
861    Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees;
862    const Elf_Hashelt *hashtab;
863    const Elf32_Word *hashval;
864    Elf32_Word bkt, nmaskwords;
865    int bloom_size32;
866    bool nmw_power2;
867    int plttype = DT_REL;
868
869    *dyn_rpath = NULL;
870    *dyn_soname = NULL;
871    *dyn_runpath = NULL;
872
873    obj->bind_now = false;
874    for (dynp = obj->dynamic;  dynp->d_tag != DT_NULL;  dynp++) {
875	switch (dynp->d_tag) {
876
877	case DT_REL:
878	    obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
879	    break;
880
881	case DT_RELSZ:
882	    obj->relsize = dynp->d_un.d_val;
883	    break;
884
885	case DT_RELENT:
886	    assert(dynp->d_un.d_val == sizeof(Elf_Rel));
887	    break;
888
889	case DT_JMPREL:
890	    obj->pltrel = (const Elf_Rel *)
891	      (obj->relocbase + dynp->d_un.d_ptr);
892	    break;
893
894	case DT_PLTRELSZ:
895	    obj->pltrelsize = dynp->d_un.d_val;
896	    break;
897
898	case DT_RELA:
899	    obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
900	    break;
901
902	case DT_RELASZ:
903	    obj->relasize = dynp->d_un.d_val;
904	    break;
905
906	case DT_RELAENT:
907	    assert(dynp->d_un.d_val == sizeof(Elf_Rela));
908	    break;
909
910	case DT_PLTREL:
911	    plttype = dynp->d_un.d_val;
912	    assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
913	    break;
914
915	case DT_SYMTAB:
916	    obj->symtab = (const Elf_Sym *)
917	      (obj->relocbase + dynp->d_un.d_ptr);
918	    break;
919
920	case DT_SYMENT:
921	    assert(dynp->d_un.d_val == sizeof(Elf_Sym));
922	    break;
923
924	case DT_STRTAB:
925	    obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
926	    break;
927
928	case DT_STRSZ:
929	    obj->strsize = dynp->d_un.d_val;
930	    break;
931
932	case DT_VERNEED:
933	    obj->verneed = (const Elf_Verneed *) (obj->relocbase +
934		dynp->d_un.d_val);
935	    break;
936
937	case DT_VERNEEDNUM:
938	    obj->verneednum = dynp->d_un.d_val;
939	    break;
940
941	case DT_VERDEF:
942	    obj->verdef = (const Elf_Verdef *) (obj->relocbase +
943		dynp->d_un.d_val);
944	    break;
945
946	case DT_VERDEFNUM:
947	    obj->verdefnum = dynp->d_un.d_val;
948	    break;
949
950	case DT_VERSYM:
951	    obj->versyms = (const Elf_Versym *)(obj->relocbase +
952		dynp->d_un.d_val);
953	    break;
954
955	case DT_HASH:
956	    {
957		hashtab = (const Elf_Hashelt *)(obj->relocbase +
958		    dynp->d_un.d_ptr);
959		obj->nbuckets = hashtab[0];
960		obj->nchains = hashtab[1];
961		obj->buckets = hashtab + 2;
962		obj->chains = obj->buckets + obj->nbuckets;
963		obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 &&
964		  obj->buckets != NULL;
965	    }
966	    break;
967
968	case DT_GNU_HASH:
969	    {
970		hashtab = (const Elf_Hashelt *)(obj->relocbase +
971		    dynp->d_un.d_ptr);
972		obj->nbuckets_gnu = hashtab[0];
973		obj->symndx_gnu = hashtab[1];
974		nmaskwords = hashtab[2];
975		bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords;
976		/* Number of bitmask words is required to be power of 2 */
977		nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0);
978		obj->maskwords_bm_gnu = nmaskwords - 1;
979		obj->shift2_gnu = hashtab[3];
980		obj->bloom_gnu = (Elf_Addr *) (hashtab + 4);
981		obj->buckets_gnu = hashtab + 4 + bloom_size32;
982		obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu -
983		  obj->symndx_gnu;
984		obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 &&
985		  obj->buckets_gnu != NULL;
986	    }
987	    break;
988
989	case DT_NEEDED:
990	    if (!obj->rtld) {
991		Needed_Entry *nep = NEW(Needed_Entry);
992		nep->name = dynp->d_un.d_val;
993		nep->obj = NULL;
994		nep->next = NULL;
995
996		*needed_tail = nep;
997		needed_tail = &nep->next;
998	    }
999	    break;
1000
1001	case DT_FILTER:
1002	    if (!obj->rtld) {
1003		Needed_Entry *nep = NEW(Needed_Entry);
1004		nep->name = dynp->d_un.d_val;
1005		nep->obj = NULL;
1006		nep->next = NULL;
1007
1008		*needed_filtees_tail = nep;
1009		needed_filtees_tail = &nep->next;
1010	    }
1011	    break;
1012
1013	case DT_AUXILIARY:
1014	    if (!obj->rtld) {
1015		Needed_Entry *nep = NEW(Needed_Entry);
1016		nep->name = dynp->d_un.d_val;
1017		nep->obj = NULL;
1018		nep->next = NULL;
1019
1020		*needed_aux_filtees_tail = nep;
1021		needed_aux_filtees_tail = &nep->next;
1022	    }
1023	    break;
1024
1025	case DT_PLTGOT:
1026	    obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
1027	    break;
1028
1029	case DT_TEXTREL:
1030	    obj->textrel = true;
1031	    break;
1032
1033	case DT_SYMBOLIC:
1034	    obj->symbolic = true;
1035	    break;
1036
1037	case DT_RPATH:
1038	    /*
1039	     * We have to wait until later to process this, because we
1040	     * might not have gotten the address of the string table yet.
1041	     */
1042	    *dyn_rpath = dynp;
1043	    break;
1044
1045	case DT_SONAME:
1046	    *dyn_soname = dynp;
1047	    break;
1048
1049	case DT_RUNPATH:
1050	    *dyn_runpath = dynp;
1051	    break;
1052
1053	case DT_INIT:
1054	    obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1055	    break;
1056
1057	case DT_PREINIT_ARRAY:
1058	    obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1059	    break;
1060
1061	case DT_PREINIT_ARRAYSZ:
1062	    obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1063	    break;
1064
1065	case DT_INIT_ARRAY:
1066	    obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1067	    break;
1068
1069	case DT_INIT_ARRAYSZ:
1070	    obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1071	    break;
1072
1073	case DT_FINI:
1074	    obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1075	    break;
1076
1077	case DT_FINI_ARRAY:
1078	    obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1079	    break;
1080
1081	case DT_FINI_ARRAYSZ:
1082	    obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1083	    break;
1084
1085	/*
1086	 * Don't process DT_DEBUG on MIPS as the dynamic section
1087	 * is mapped read-only. DT_MIPS_RLD_MAP is used instead.
1088	 */
1089
1090#ifndef __mips__
1091	case DT_DEBUG:
1092	    /* XXX - not implemented yet */
1093	    if (!early)
1094		dbg("Filling in DT_DEBUG entry");
1095	    ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
1096	    break;
1097#endif
1098
1099	case DT_FLAGS:
1100		if ((dynp->d_un.d_val & DF_ORIGIN) && trust)
1101		    obj->z_origin = true;
1102		if (dynp->d_un.d_val & DF_SYMBOLIC)
1103		    obj->symbolic = true;
1104		if (dynp->d_un.d_val & DF_TEXTREL)
1105		    obj->textrel = true;
1106		if (dynp->d_un.d_val & DF_BIND_NOW)
1107		    obj->bind_now = true;
1108		/*if (dynp->d_un.d_val & DF_STATIC_TLS)
1109		    ;*/
1110	    break;
1111#ifdef __mips__
1112	case DT_MIPS_LOCAL_GOTNO:
1113		obj->local_gotno = dynp->d_un.d_val;
1114	    break;
1115
1116	case DT_MIPS_SYMTABNO:
1117		obj->symtabno = dynp->d_un.d_val;
1118		break;
1119
1120	case DT_MIPS_GOTSYM:
1121		obj->gotsym = dynp->d_un.d_val;
1122		break;
1123
1124	case DT_MIPS_RLD_MAP:
1125		*((Elf_Addr *)(dynp->d_un.d_ptr)) = (Elf_Addr) &r_debug;
1126		break;
1127#endif
1128
1129	case DT_FLAGS_1:
1130		if (dynp->d_un.d_val & DF_1_NOOPEN)
1131		    obj->z_noopen = true;
1132		if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
1133		    obj->z_origin = true;
1134		/*if (dynp->d_un.d_val & DF_1_GLOBAL)
1135		    XXX ;*/
1136		if (dynp->d_un.d_val & DF_1_BIND_NOW)
1137		    obj->bind_now = true;
1138		if (dynp->d_un.d_val & DF_1_NODELETE)
1139		    obj->z_nodelete = true;
1140		if (dynp->d_un.d_val & DF_1_LOADFLTR)
1141		    obj->z_loadfltr = true;
1142		if (dynp->d_un.d_val & DF_1_INTERPOSE)
1143		    obj->z_interpose = true;
1144		if (dynp->d_un.d_val & DF_1_NODEFLIB)
1145		    obj->z_nodeflib = true;
1146	    break;
1147
1148	default:
1149	    if (!early) {
1150		dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
1151		    (long)dynp->d_tag);
1152	    }
1153	    break;
1154	}
1155    }
1156
1157    obj->traced = false;
1158
1159    if (plttype == DT_RELA) {
1160	obj->pltrela = (const Elf_Rela *) obj->pltrel;
1161	obj->pltrel = NULL;
1162	obj->pltrelasize = obj->pltrelsize;
1163	obj->pltrelsize = 0;
1164    }
1165
1166    /* Determine size of dynsym table (equal to nchains of sysv hash) */
1167    if (obj->valid_hash_sysv)
1168	obj->dynsymcount = obj->nchains;
1169    else if (obj->valid_hash_gnu) {
1170	obj->dynsymcount = 0;
1171	for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) {
1172	    if (obj->buckets_gnu[bkt] == 0)
1173		continue;
1174	    hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]];
1175	    do
1176		obj->dynsymcount++;
1177	    while ((*hashval++ & 1u) == 0);
1178	}
1179	obj->dynsymcount += obj->symndx_gnu;
1180    }
1181}
1182
1183static void
1184digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
1185    const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath)
1186{
1187
1188    if (obj->z_origin && obj->origin_path == NULL) {
1189	obj->origin_path = xmalloc(PATH_MAX);
1190	if (rtld_dirname_abs(obj->path, obj->origin_path) == -1)
1191	    die();
1192    }
1193
1194    if (dyn_runpath != NULL) {
1195	obj->runpath = (char *)obj->strtab + dyn_runpath->d_un.d_val;
1196	if (obj->z_origin)
1197	    obj->runpath = origin_subst(obj->runpath, obj->origin_path);
1198    }
1199    else if (dyn_rpath != NULL) {
1200	obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
1201	if (obj->z_origin)
1202	    obj->rpath = origin_subst(obj->rpath, obj->origin_path);
1203    }
1204
1205    if (dyn_soname != NULL)
1206	object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
1207}
1208
1209static void
1210digest_dynamic(Obj_Entry *obj, int early)
1211{
1212	const Elf_Dyn *dyn_rpath;
1213	const Elf_Dyn *dyn_soname;
1214	const Elf_Dyn *dyn_runpath;
1215
1216	digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath);
1217	digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath);
1218}
1219
1220/*
1221 * Process a shared object's program header.  This is used only for the
1222 * main program, when the kernel has already loaded the main program
1223 * into memory before calling the dynamic linker.  It creates and
1224 * returns an Obj_Entry structure.
1225 */
1226static Obj_Entry *
1227digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
1228{
1229    Obj_Entry *obj;
1230    const Elf_Phdr *phlimit = phdr + phnum;
1231    const Elf_Phdr *ph;
1232    Elf_Addr note_start, note_end;
1233    int nsegs = 0;
1234
1235    obj = obj_new();
1236    for (ph = phdr;  ph < phlimit;  ph++) {
1237	if (ph->p_type != PT_PHDR)
1238	    continue;
1239
1240	obj->phdr = phdr;
1241	obj->phsize = ph->p_memsz;
1242	obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
1243	break;
1244    }
1245
1246    obj->stack_flags = PF_X | PF_R | PF_W;
1247
1248    for (ph = phdr;  ph < phlimit;  ph++) {
1249	switch (ph->p_type) {
1250
1251	case PT_INTERP:
1252	    obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
1253	    break;
1254
1255	case PT_LOAD:
1256	    if (nsegs == 0) {	/* First load segment */
1257		obj->vaddrbase = trunc_page(ph->p_vaddr);
1258		obj->mapbase = obj->vaddrbase + obj->relocbase;
1259		obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
1260		  obj->vaddrbase;
1261	    } else {		/* Last load segment */
1262		obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1263		  obj->vaddrbase;
1264	    }
1265	    nsegs++;
1266	    break;
1267
1268	case PT_DYNAMIC:
1269	    obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
1270	    break;
1271
1272	case PT_TLS:
1273	    obj->tlsindex = 1;
1274	    obj->tlssize = ph->p_memsz;
1275	    obj->tlsalign = ph->p_align;
1276	    obj->tlsinitsize = ph->p_filesz;
1277	    obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
1278	    break;
1279
1280	case PT_GNU_STACK:
1281	    obj->stack_flags = ph->p_flags;
1282	    break;
1283
1284	case PT_GNU_RELRO:
1285	    obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
1286	    obj->relro_size = round_page(ph->p_memsz);
1287	    break;
1288
1289	case PT_NOTE:
1290	    note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr;
1291	    note_end = note_start + ph->p_filesz;
1292	    digest_notes(obj, note_start, note_end);
1293	    break;
1294	}
1295    }
1296    if (nsegs < 1) {
1297	_rtld_error("%s: too few PT_LOAD segments", path);
1298	return NULL;
1299    }
1300
1301    obj->entry = entry;
1302    return obj;
1303}
1304
1305void
1306digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end)
1307{
1308	const Elf_Note *note;
1309	const char *note_name;
1310	uintptr_t p;
1311
1312	for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end;
1313	    note = (const Elf_Note *)((const char *)(note + 1) +
1314	      roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
1315	      roundup2(note->n_descsz, sizeof(Elf32_Addr)))) {
1316		if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) ||
1317		    note->n_descsz != sizeof(int32_t))
1318			continue;
1319		if (note->n_type != ABI_NOTETYPE &&
1320		    note->n_type != CRT_NOINIT_NOTETYPE)
1321			continue;
1322		note_name = (const char *)(note + 1);
1323		if (strncmp(NOTE_FREEBSD_VENDOR, note_name,
1324		    sizeof(NOTE_FREEBSD_VENDOR)) != 0)
1325			continue;
1326		switch (note->n_type) {
1327		case ABI_NOTETYPE:
1328			/* FreeBSD osrel note */
1329			p = (uintptr_t)(note + 1);
1330			p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1331			obj->osrel = *(const int32_t *)(p);
1332			dbg("note osrel %d", obj->osrel);
1333			break;
1334		case CRT_NOINIT_NOTETYPE:
1335			/* FreeBSD 'crt does not call init' note */
1336			obj->crt_no_init = true;
1337			dbg("note crt_no_init");
1338			break;
1339		}
1340	}
1341}
1342
1343static Obj_Entry *
1344dlcheck(void *handle)
1345{
1346    Obj_Entry *obj;
1347
1348    for (obj = obj_list;  obj != NULL;  obj = obj->next)
1349	if (obj == (Obj_Entry *) handle)
1350	    break;
1351
1352    if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1353	_rtld_error("Invalid shared object handle %p", handle);
1354	return NULL;
1355    }
1356    return obj;
1357}
1358
1359/*
1360 * If the given object is already in the donelist, return true.  Otherwise
1361 * add the object to the list and return false.
1362 */
1363static bool
1364donelist_check(DoneList *dlp, const Obj_Entry *obj)
1365{
1366    unsigned int i;
1367
1368    for (i = 0;  i < dlp->num_used;  i++)
1369	if (dlp->objs[i] == obj)
1370	    return true;
1371    /*
1372     * Our donelist allocation should always be sufficient.  But if
1373     * our threads locking isn't working properly, more shared objects
1374     * could have been loaded since we allocated the list.  That should
1375     * never happen, but we'll handle it properly just in case it does.
1376     */
1377    if (dlp->num_used < dlp->num_alloc)
1378	dlp->objs[dlp->num_used++] = obj;
1379    return false;
1380}
1381
1382/*
1383 * Hash function for symbol table lookup.  Don't even think about changing
1384 * this.  It is specified by the System V ABI.
1385 */
1386unsigned long
1387elf_hash(const char *name)
1388{
1389    const unsigned char *p = (const unsigned char *) name;
1390    unsigned long h = 0;
1391    unsigned long g;
1392
1393    while (*p != '\0') {
1394	h = (h << 4) + *p++;
1395	if ((g = h & 0xf0000000) != 0)
1396	    h ^= g >> 24;
1397	h &= ~g;
1398    }
1399    return h;
1400}
1401
1402/*
1403 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits
1404 * unsigned in case it's implemented with a wider type.
1405 */
1406static uint32_t
1407gnu_hash(const char *s)
1408{
1409	uint32_t h;
1410	unsigned char c;
1411
1412	h = 5381;
1413	for (c = *s; c != '\0'; c = *++s)
1414		h = h * 33 + c;
1415	return (h & 0xffffffff);
1416}
1417
1418/*
1419 * Find the library with the given name, and return its full pathname.
1420 * The returned string is dynamically allocated.  Generates an error
1421 * message and returns NULL if the library cannot be found.
1422 *
1423 * If the second argument is non-NULL, then it refers to an already-
1424 * loaded shared object, whose library search path will be searched.
1425 *
1426 * The search order is:
1427 *   DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1)
1428 *   DT_RPATH of the main object if DSO without defined DT_RUNPATH (1)
1429 *   LD_LIBRARY_PATH
1430 *   DT_RUNPATH in the referencing file
1431 *   ldconfig hints (if -z nodefaultlib, filter out default library directories
1432 *	 from list)
1433 *   /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib
1434 *
1435 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined.
1436 */
1437static char *
1438find_library(const char *xname, const Obj_Entry *refobj)
1439{
1440    char *pathname;
1441    char *name;
1442    bool nodeflib, objgiven;
1443
1444    objgiven = refobj != NULL;
1445    if (strchr(xname, '/') != NULL) {	/* Hard coded pathname */
1446	if (xname[0] != '/' && !trust) {
1447	    _rtld_error("Absolute pathname required for shared object \"%s\"",
1448	      xname);
1449	    return NULL;
1450	}
1451	if (objgiven && refobj->z_origin) {
1452		return (origin_subst(__DECONST(char *, xname),
1453		    refobj->origin_path));
1454	} else {
1455		return (xstrdup(xname));
1456	}
1457    }
1458
1459    if (libmap_disable || !objgiven ||
1460	(name = lm_find(refobj->path, xname)) == NULL)
1461	name = (char *)xname;
1462
1463    dbg(" Searching for \"%s\"", name);
1464
1465    /*
1466     * If refobj->rpath != NULL, then refobj->runpath is NULL.  Fall
1467     * back to pre-conforming behaviour if user requested so with
1468     * LD_LIBRARY_PATH_RPATH environment variable and ignore -z
1469     * nodeflib.
1470     */
1471    if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) {
1472	if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
1473	  (refobj != NULL &&
1474	  (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1475          (pathname = search_library_path(name, gethints(false))) != NULL ||
1476	  (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
1477	    return (pathname);
1478    } else {
1479	nodeflib = objgiven ? refobj->z_nodeflib : false;
1480	if ((objgiven &&
1481	  (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1482	  (objgiven && refobj->runpath == NULL && refobj != obj_main &&
1483	  (pathname = search_library_path(name, obj_main->rpath)) != NULL) ||
1484	  (pathname = search_library_path(name, ld_library_path)) != NULL ||
1485	  (objgiven &&
1486	  (pathname = search_library_path(name, refobj->runpath)) != NULL) ||
1487	  (pathname = search_library_path(name, gethints(nodeflib))) != NULL ||
1488	  (objgiven && !nodeflib &&
1489	  (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL))
1490	    return (pathname);
1491    }
1492
1493    if (objgiven && refobj->path != NULL) {
1494	_rtld_error("Shared object \"%s\" not found, required by \"%s\"",
1495	  name, basename(refobj->path));
1496    } else {
1497	_rtld_error("Shared object \"%s\" not found", name);
1498    }
1499    return NULL;
1500}
1501
1502/*
1503 * Given a symbol number in a referencing object, find the corresponding
1504 * definition of the symbol.  Returns a pointer to the symbol, or NULL if
1505 * no definition was found.  Returns a pointer to the Obj_Entry of the
1506 * defining object via the reference parameter DEFOBJ_OUT.
1507 */
1508const Elf_Sym *
1509find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1510    const Obj_Entry **defobj_out, int flags, SymCache *cache,
1511    RtldLockState *lockstate)
1512{
1513    const Elf_Sym *ref;
1514    const Elf_Sym *def;
1515    const Obj_Entry *defobj;
1516    SymLook req;
1517    const char *name;
1518    int res;
1519
1520    /*
1521     * If we have already found this symbol, get the information from
1522     * the cache.
1523     */
1524    if (symnum >= refobj->dynsymcount)
1525	return NULL;	/* Bad object */
1526    if (cache != NULL && cache[symnum].sym != NULL) {
1527	*defobj_out = cache[symnum].obj;
1528	return cache[symnum].sym;
1529    }
1530
1531    ref = refobj->symtab + symnum;
1532    name = refobj->strtab + ref->st_name;
1533    def = NULL;
1534    defobj = NULL;
1535
1536    /*
1537     * We don't have to do a full scale lookup if the symbol is local.
1538     * We know it will bind to the instance in this load module; to
1539     * which we already have a pointer (ie ref). By not doing a lookup,
1540     * we not only improve performance, but it also avoids unresolvable
1541     * symbols when local symbols are not in the hash table. This has
1542     * been seen with the ia64 toolchain.
1543     */
1544    if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1545	if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
1546	    _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1547		symnum);
1548	}
1549	symlook_init(&req, name);
1550	req.flags = flags;
1551	req.ventry = fetch_ventry(refobj, symnum);
1552	req.lockstate = lockstate;
1553	res = symlook_default(&req, refobj);
1554	if (res == 0) {
1555	    def = req.sym_out;
1556	    defobj = req.defobj_out;
1557	}
1558    } else {
1559	def = ref;
1560	defobj = refobj;
1561    }
1562
1563    /*
1564     * If we found no definition and the reference is weak, treat the
1565     * symbol as having the value zero.
1566     */
1567    if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1568	def = &sym_zero;
1569	defobj = obj_main;
1570    }
1571
1572    if (def != NULL) {
1573	*defobj_out = defobj;
1574	/* Record the information in the cache to avoid subsequent lookups. */
1575	if (cache != NULL) {
1576	    cache[symnum].sym = def;
1577	    cache[symnum].obj = defobj;
1578	}
1579    } else {
1580	if (refobj != &obj_rtld)
1581	    _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1582    }
1583    return def;
1584}
1585
1586/*
1587 * Return the search path from the ldconfig hints file, reading it if
1588 * necessary.  If nostdlib is true, then the default search paths are
1589 * not added to result.
1590 *
1591 * Returns NULL if there are problems with the hints file,
1592 * or if the search path there is empty.
1593 */
1594static const char *
1595gethints(bool nostdlib)
1596{
1597	static char *hints, *filtered_path;
1598	struct elfhints_hdr hdr;
1599	struct fill_search_info_args sargs, hargs;
1600	struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo;
1601	struct dl_serpath *SLPpath, *hintpath;
1602	char *p;
1603	unsigned int SLPndx, hintndx, fndx, fcount;
1604	int fd;
1605	size_t flen;
1606	bool skip;
1607
1608	/* First call, read the hints file */
1609	if (hints == NULL) {
1610		/* Keep from trying again in case the hints file is bad. */
1611		hints = "";
1612
1613		if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1)
1614			return (NULL);
1615		if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1616		    hdr.magic != ELFHINTS_MAGIC ||
1617		    hdr.version != 1) {
1618			close(fd);
1619			return (NULL);
1620		}
1621		p = xmalloc(hdr.dirlistlen + 1);
1622		if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
1623		    read(fd, p, hdr.dirlistlen + 1) !=
1624		    (ssize_t)hdr.dirlistlen + 1) {
1625			free(p);
1626			close(fd);
1627			return (NULL);
1628		}
1629		hints = p;
1630		close(fd);
1631	}
1632
1633	/*
1634	 * If caller agreed to receive list which includes the default
1635	 * paths, we are done. Otherwise, if we still did not
1636	 * calculated filtered result, do it now.
1637	 */
1638	if (!nostdlib)
1639		return (hints[0] != '\0' ? hints : NULL);
1640	if (filtered_path != NULL)
1641		goto filt_ret;
1642
1643	/*
1644	 * Obtain the list of all configured search paths, and the
1645	 * list of the default paths.
1646	 *
1647	 * First estimate the size of the results.
1648	 */
1649	smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
1650	smeta.dls_cnt = 0;
1651	hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
1652	hmeta.dls_cnt = 0;
1653
1654	sargs.request = RTLD_DI_SERINFOSIZE;
1655	sargs.serinfo = &smeta;
1656	hargs.request = RTLD_DI_SERINFOSIZE;
1657	hargs.serinfo = &hmeta;
1658
1659	path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs);
1660	path_enumerate(p, fill_search_info, &hargs);
1661
1662	SLPinfo = xmalloc(smeta.dls_size);
1663	hintinfo = xmalloc(hmeta.dls_size);
1664
1665	/*
1666	 * Next fetch both sets of paths.
1667	 */
1668	sargs.request = RTLD_DI_SERINFO;
1669	sargs.serinfo = SLPinfo;
1670	sargs.serpath = &SLPinfo->dls_serpath[0];
1671	sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt];
1672
1673	hargs.request = RTLD_DI_SERINFO;
1674	hargs.serinfo = hintinfo;
1675	hargs.serpath = &hintinfo->dls_serpath[0];
1676	hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt];
1677
1678	path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &sargs);
1679	path_enumerate(p, fill_search_info, &hargs);
1680
1681	/*
1682	 * Now calculate the difference between two sets, by excluding
1683	 * standard paths from the full set.
1684	 */
1685	fndx = 0;
1686	fcount = 0;
1687	filtered_path = xmalloc(hdr.dirlistlen + 1);
1688	hintpath = &hintinfo->dls_serpath[0];
1689	for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) {
1690		skip = false;
1691		SLPpath = &SLPinfo->dls_serpath[0];
1692		/*
1693		 * Check each standard path against current.
1694		 */
1695		for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) {
1696			/* matched, skip the path */
1697			if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) {
1698				skip = true;
1699				break;
1700			}
1701		}
1702		if (skip)
1703			continue;
1704		/*
1705		 * Not matched against any standard path, add the path
1706		 * to result. Separate consequtive paths with ':'.
1707		 */
1708		if (fcount > 0) {
1709			filtered_path[fndx] = ':';
1710			fndx++;
1711		}
1712		fcount++;
1713		flen = strlen(hintpath->dls_name);
1714		strncpy((filtered_path + fndx),	hintpath->dls_name, flen);
1715		fndx += flen;
1716	}
1717	filtered_path[fndx] = '\0';
1718
1719	free(SLPinfo);
1720	free(hintinfo);
1721
1722filt_ret:
1723	return (filtered_path[0] != '\0' ? filtered_path : NULL);
1724}
1725
1726static void
1727init_dag(Obj_Entry *root)
1728{
1729    const Needed_Entry *needed;
1730    const Objlist_Entry *elm;
1731    DoneList donelist;
1732
1733    if (root->dag_inited)
1734	return;
1735    donelist_init(&donelist);
1736
1737    /* Root object belongs to own DAG. */
1738    objlist_push_tail(&root->dldags, root);
1739    objlist_push_tail(&root->dagmembers, root);
1740    donelist_check(&donelist, root);
1741
1742    /*
1743     * Add dependencies of root object to DAG in breadth order
1744     * by exploiting the fact that each new object get added
1745     * to the tail of the dagmembers list.
1746     */
1747    STAILQ_FOREACH(elm, &root->dagmembers, link) {
1748	for (needed = elm->obj->needed; needed != NULL; needed = needed->next) {
1749	    if (needed->obj == NULL || donelist_check(&donelist, needed->obj))
1750		continue;
1751	    objlist_push_tail(&needed->obj->dldags, root);
1752	    objlist_push_tail(&root->dagmembers, needed->obj);
1753	}
1754    }
1755    root->dag_inited = true;
1756}
1757
1758static void
1759process_nodelete(Obj_Entry *root)
1760{
1761	const Objlist_Entry *elm;
1762
1763	/*
1764	 * Walk over object DAG and process every dependent object that
1765	 * is marked as DF_1_NODELETE. They need to grow their own DAG,
1766	 * which then should have its reference upped separately.
1767	 */
1768	STAILQ_FOREACH(elm, &root->dagmembers, link) {
1769		if (elm->obj != NULL && elm->obj->z_nodelete &&
1770		    !elm->obj->ref_nodel) {
1771			dbg("obj %s nodelete", elm->obj->path);
1772			init_dag(elm->obj);
1773			ref_dag(elm->obj);
1774			elm->obj->ref_nodel = true;
1775		}
1776	}
1777}
1778/*
1779 * Initialize the dynamic linker.  The argument is the address at which
1780 * the dynamic linker has been mapped into memory.  The primary task of
1781 * this function is to relocate the dynamic linker.
1782 */
1783static void
1784init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
1785{
1786    Obj_Entry objtmp;	/* Temporary rtld object */
1787    const Elf_Dyn *dyn_rpath;
1788    const Elf_Dyn *dyn_soname;
1789    const Elf_Dyn *dyn_runpath;
1790
1791    /*
1792     * Conjure up an Obj_Entry structure for the dynamic linker.
1793     *
1794     * The "path" member can't be initialized yet because string constants
1795     * cannot yet be accessed. Below we will set it correctly.
1796     */
1797    memset(&objtmp, 0, sizeof(objtmp));
1798    objtmp.path = NULL;
1799    objtmp.rtld = true;
1800    objtmp.mapbase = mapbase;
1801#ifdef PIC
1802    objtmp.relocbase = mapbase;
1803#endif
1804    if (RTLD_IS_DYNAMIC()) {
1805	objtmp.dynamic = rtld_dynamic(&objtmp);
1806	digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath);
1807	assert(objtmp.needed == NULL);
1808#if !defined(__mips__)
1809	/* MIPS has a bogus DT_TEXTREL. */
1810	assert(!objtmp.textrel);
1811#endif
1812
1813	/*
1814	 * Temporarily put the dynamic linker entry into the object list, so
1815	 * that symbols can be found.
1816	 */
1817
1818	relocate_objects(&objtmp, true, &objtmp, 0, NULL);
1819    }
1820
1821    /* Initialize the object list. */
1822    obj_tail = &obj_list;
1823
1824    /* Now that non-local variables can be accesses, copy out obj_rtld. */
1825    memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
1826
1827    if (aux_info[AT_PAGESZ] != NULL)
1828	    pagesize = aux_info[AT_PAGESZ]->a_un.a_val;
1829    if (aux_info[AT_OSRELDATE] != NULL)
1830	    osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
1831
1832    digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath);
1833
1834    /* Replace the path with a dynamically allocated copy. */
1835    obj_rtld.path = xstrdup(PATH_RTLD);
1836
1837    r_debug.r_brk = r_debug_state;
1838    r_debug.r_state = RT_CONSISTENT;
1839}
1840
1841/*
1842 * Add the init functions from a needed object list (and its recursive
1843 * needed objects) to "list".  This is not used directly; it is a helper
1844 * function for initlist_add_objects().  The write lock must be held
1845 * when this function is called.
1846 */
1847static void
1848initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1849{
1850    /* Recursively process the successor needed objects. */
1851    if (needed->next != NULL)
1852	initlist_add_neededs(needed->next, list);
1853
1854    /* Process the current needed object. */
1855    if (needed->obj != NULL)
1856	initlist_add_objects(needed->obj, &needed->obj->next, list);
1857}
1858
1859/*
1860 * Scan all of the DAGs rooted in the range of objects from "obj" to
1861 * "tail" and add their init functions to "list".  This recurses over
1862 * the DAGs and ensure the proper init ordering such that each object's
1863 * needed libraries are initialized before the object itself.  At the
1864 * same time, this function adds the objects to the global finalization
1865 * list "list_fini" in the opposite order.  The write lock must be
1866 * held when this function is called.
1867 */
1868static void
1869initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1870{
1871
1872    if (obj->init_scanned || obj->init_done)
1873	return;
1874    obj->init_scanned = true;
1875
1876    /* Recursively process the successor objects. */
1877    if (&obj->next != tail)
1878	initlist_add_objects(obj->next, tail, list);
1879
1880    /* Recursively process the needed objects. */
1881    if (obj->needed != NULL)
1882	initlist_add_neededs(obj->needed, list);
1883    if (obj->needed_filtees != NULL)
1884	initlist_add_neededs(obj->needed_filtees, list);
1885    if (obj->needed_aux_filtees != NULL)
1886	initlist_add_neededs(obj->needed_aux_filtees, list);
1887
1888    /* Add the object to the init list. */
1889    if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL ||
1890      obj->init_array != (Elf_Addr)NULL)
1891	objlist_push_tail(list, obj);
1892
1893    /* Add the object to the global fini list in the reverse order. */
1894    if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL)
1895      && !obj->on_fini_list) {
1896	objlist_push_head(&list_fini, obj);
1897	obj->on_fini_list = true;
1898    }
1899}
1900
1901#ifndef FPTR_TARGET
1902#define FPTR_TARGET(f)	((Elf_Addr) (f))
1903#endif
1904
1905static void
1906free_needed_filtees(Needed_Entry *n)
1907{
1908    Needed_Entry *needed, *needed1;
1909
1910    for (needed = n; needed != NULL; needed = needed->next) {
1911	if (needed->obj != NULL) {
1912	    dlclose(needed->obj);
1913	    needed->obj = NULL;
1914	}
1915    }
1916    for (needed = n; needed != NULL; needed = needed1) {
1917	needed1 = needed->next;
1918	free(needed);
1919    }
1920}
1921
1922static void
1923unload_filtees(Obj_Entry *obj)
1924{
1925
1926    free_needed_filtees(obj->needed_filtees);
1927    obj->needed_filtees = NULL;
1928    free_needed_filtees(obj->needed_aux_filtees);
1929    obj->needed_aux_filtees = NULL;
1930    obj->filtees_loaded = false;
1931}
1932
1933static void
1934load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags,
1935    RtldLockState *lockstate)
1936{
1937
1938    for (; needed != NULL; needed = needed->next) {
1939	needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj,
1940	  flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) |
1941	  RTLD_LOCAL, lockstate);
1942    }
1943}
1944
1945static void
1946load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate)
1947{
1948
1949    lock_restart_for_upgrade(lockstate);
1950    if (!obj->filtees_loaded) {
1951	load_filtee1(obj, obj->needed_filtees, flags, lockstate);
1952	load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate);
1953	obj->filtees_loaded = true;
1954    }
1955}
1956
1957static int
1958process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags)
1959{
1960    Obj_Entry *obj1;
1961
1962    for (; needed != NULL; needed = needed->next) {
1963	obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj,
1964	  flags & ~RTLD_LO_NOLOAD);
1965	if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0)
1966	    return (-1);
1967    }
1968    return (0);
1969}
1970
1971/*
1972 * Given a shared object, traverse its list of needed objects, and load
1973 * each of them.  Returns 0 on success.  Generates an error message and
1974 * returns -1 on failure.
1975 */
1976static int
1977load_needed_objects(Obj_Entry *first, int flags)
1978{
1979    Obj_Entry *obj;
1980
1981    for (obj = first;  obj != NULL;  obj = obj->next) {
1982	if (process_needed(obj, obj->needed, flags) == -1)
1983	    return (-1);
1984    }
1985    return (0);
1986}
1987
1988static int
1989load_preload_objects(void)
1990{
1991    char *p = ld_preload;
1992    Obj_Entry *obj;
1993    static const char delim[] = " \t:;";
1994
1995    if (p == NULL)
1996	return 0;
1997
1998    p += strspn(p, delim);
1999    while (*p != '\0') {
2000	size_t len = strcspn(p, delim);
2001	char savech;
2002
2003	savech = p[len];
2004	p[len] = '\0';
2005	obj = load_object(p, -1, NULL, 0);
2006	if (obj == NULL)
2007	    return -1;	/* XXX - cleanup */
2008	obj->z_interpose = true;
2009	p[len] = savech;
2010	p += len;
2011	p += strspn(p, delim);
2012    }
2013    LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
2014    return 0;
2015}
2016
2017static const char *
2018printable_path(const char *path)
2019{
2020
2021	return (path == NULL ? "<unknown>" : path);
2022}
2023
2024/*
2025 * Load a shared object into memory, if it is not already loaded.  The
2026 * object may be specified by name or by user-supplied file descriptor
2027 * fd_u. In the later case, the fd_u descriptor is not closed, but its
2028 * duplicate is.
2029 *
2030 * Returns a pointer to the Obj_Entry for the object.  Returns NULL
2031 * on failure.
2032 */
2033static Obj_Entry *
2034load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags)
2035{
2036    Obj_Entry *obj;
2037    int fd;
2038    struct stat sb;
2039    char *path;
2040
2041    if (name != NULL) {
2042	for (obj = obj_list->next;  obj != NULL;  obj = obj->next) {
2043	    if (object_match_name(obj, name))
2044		return (obj);
2045	}
2046
2047	path = find_library(name, refobj);
2048	if (path == NULL)
2049	    return (NULL);
2050    } else
2051	path = NULL;
2052
2053    /*
2054     * If we didn't find a match by pathname, or the name is not
2055     * supplied, open the file and check again by device and inode.
2056     * This avoids false mismatches caused by multiple links or ".."
2057     * in pathnames.
2058     *
2059     * To avoid a race, we open the file and use fstat() rather than
2060     * using stat().
2061     */
2062    fd = -1;
2063    if (fd_u == -1) {
2064	if ((fd = open(path, O_RDONLY | O_CLOEXEC)) == -1) {
2065	    _rtld_error("Cannot open \"%s\"", path);
2066	    free(path);
2067	    return (NULL);
2068	}
2069    } else {
2070	fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0);
2071	if (fd == -1) {
2072	    _rtld_error("Cannot dup fd");
2073	    free(path);
2074	    return (NULL);
2075	}
2076    }
2077    if (fstat(fd, &sb) == -1) {
2078	_rtld_error("Cannot fstat \"%s\"", printable_path(path));
2079	close(fd);
2080	free(path);
2081	return NULL;
2082    }
2083    for (obj = obj_list->next;  obj != NULL;  obj = obj->next)
2084	if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
2085	    break;
2086    if (obj != NULL && name != NULL) {
2087	object_add_name(obj, name);
2088	free(path);
2089	close(fd);
2090	return obj;
2091    }
2092    if (flags & RTLD_LO_NOLOAD) {
2093	free(path);
2094	close(fd);
2095	return (NULL);
2096    }
2097
2098    /* First use of this object, so we must map it in */
2099    obj = do_load_object(fd, name, path, &sb, flags);
2100    if (obj == NULL)
2101	free(path);
2102    close(fd);
2103
2104    return obj;
2105}
2106
2107static Obj_Entry *
2108do_load_object(int fd, const char *name, char *path, struct stat *sbp,
2109  int flags)
2110{
2111    Obj_Entry *obj;
2112    struct statfs fs;
2113
2114    /*
2115     * but first, make sure that environment variables haven't been
2116     * used to circumvent the noexec flag on a filesystem.
2117     */
2118    if (dangerous_ld_env) {
2119	if (fstatfs(fd, &fs) != 0) {
2120	    _rtld_error("Cannot fstatfs \"%s\"", printable_path(path));
2121	    return NULL;
2122	}
2123	if (fs.f_flags & MNT_NOEXEC) {
2124	    _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
2125	    return NULL;
2126	}
2127    }
2128    dbg("loading \"%s\"", printable_path(path));
2129    obj = map_object(fd, printable_path(path), sbp);
2130    if (obj == NULL)
2131        return NULL;
2132
2133    /*
2134     * If DT_SONAME is present in the object, digest_dynamic2 already
2135     * added it to the object names.
2136     */
2137    if (name != NULL)
2138	object_add_name(obj, name);
2139    obj->path = path;
2140    digest_dynamic(obj, 0);
2141    dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path,
2142	obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount);
2143    if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
2144      RTLD_LO_DLOPEN) {
2145	dbg("refusing to load non-loadable \"%s\"", obj->path);
2146	_rtld_error("Cannot dlopen non-loadable %s", obj->path);
2147	munmap(obj->mapbase, obj->mapsize);
2148	obj_free(obj);
2149	return (NULL);
2150    }
2151
2152    obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0;
2153    *obj_tail = obj;
2154    obj_tail = &obj->next;
2155    obj_count++;
2156    obj_loads++;
2157    linkmap_add(obj);	/* for GDB & dlinfo() */
2158    max_stack_flags |= obj->stack_flags;
2159
2160    dbg("  %p .. %p: %s", obj->mapbase,
2161         obj->mapbase + obj->mapsize - 1, obj->path);
2162    if (obj->textrel)
2163	dbg("  WARNING: %s has impure text", obj->path);
2164    LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
2165	obj->path);
2166
2167    return obj;
2168}
2169
2170static Obj_Entry *
2171obj_from_addr(const void *addr)
2172{
2173    Obj_Entry *obj;
2174
2175    for (obj = obj_list;  obj != NULL;  obj = obj->next) {
2176	if (addr < (void *) obj->mapbase)
2177	    continue;
2178	if (addr < (void *) (obj->mapbase + obj->mapsize))
2179	    return obj;
2180    }
2181    return NULL;
2182}
2183
2184static void
2185preinit_main(void)
2186{
2187    Elf_Addr *preinit_addr;
2188    int index;
2189
2190    preinit_addr = (Elf_Addr *)obj_main->preinit_array;
2191    if (preinit_addr == NULL)
2192	return;
2193
2194    for (index = 0; index < obj_main->preinit_array_num; index++) {
2195	if (preinit_addr[index] != 0 && preinit_addr[index] != 1) {
2196	    dbg("calling preinit function for %s at %p", obj_main->path,
2197	      (void *)preinit_addr[index]);
2198	    LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index],
2199	      0, 0, obj_main->path);
2200	    call_init_pointer(obj_main, preinit_addr[index]);
2201	}
2202    }
2203}
2204
2205/*
2206 * Call the finalization functions for each of the objects in "list"
2207 * belonging to the DAG of "root" and referenced once. If NULL "root"
2208 * is specified, every finalization function will be called regardless
2209 * of the reference count and the list elements won't be freed. All of
2210 * the objects are expected to have non-NULL fini functions.
2211 */
2212static void
2213objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
2214{
2215    Objlist_Entry *elm;
2216    char *saved_msg;
2217    Elf_Addr *fini_addr;
2218    int index;
2219
2220    assert(root == NULL || root->refcount == 1);
2221
2222    /*
2223     * Preserve the current error message since a fini function might
2224     * call into the dynamic linker and overwrite it.
2225     */
2226    saved_msg = errmsg_save();
2227    do {
2228	STAILQ_FOREACH(elm, list, link) {
2229	    if (root != NULL && (elm->obj->refcount != 1 ||
2230	      objlist_find(&root->dagmembers, elm->obj) == NULL))
2231		continue;
2232	    /* Remove object from fini list to prevent recursive invocation. */
2233	    STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2234	    /*
2235	     * XXX: If a dlopen() call references an object while the
2236	     * fini function is in progress, we might end up trying to
2237	     * unload the referenced object in dlclose() or the object
2238	     * won't be unloaded although its fini function has been
2239	     * called.
2240	     */
2241	    lock_release(rtld_bind_lock, lockstate);
2242
2243	    /*
2244	     * It is legal to have both DT_FINI and DT_FINI_ARRAY defined.
2245	     * When this happens, DT_FINI_ARRAY is processed first.
2246	     */
2247	    fini_addr = (Elf_Addr *)elm->obj->fini_array;
2248	    if (fini_addr != NULL && elm->obj->fini_array_num > 0) {
2249		for (index = elm->obj->fini_array_num - 1; index >= 0;
2250		  index--) {
2251		    if (fini_addr[index] != 0 && fini_addr[index] != 1) {
2252			dbg("calling fini function for %s at %p",
2253			    elm->obj->path, (void *)fini_addr[index]);
2254			LD_UTRACE(UTRACE_FINI_CALL, elm->obj,
2255			    (void *)fini_addr[index], 0, 0, elm->obj->path);
2256			call_initfini_pointer(elm->obj, fini_addr[index]);
2257		    }
2258		}
2259	    }
2260	    if (elm->obj->fini != (Elf_Addr)NULL) {
2261		dbg("calling fini function for %s at %p", elm->obj->path,
2262		    (void *)elm->obj->fini);
2263		LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini,
2264		    0, 0, elm->obj->path);
2265		call_initfini_pointer(elm->obj, elm->obj->fini);
2266	    }
2267	    wlock_acquire(rtld_bind_lock, lockstate);
2268	    /* No need to free anything if process is going down. */
2269	    if (root != NULL)
2270	    	free(elm);
2271	    /*
2272	     * We must restart the list traversal after every fini call
2273	     * because a dlclose() call from the fini function or from
2274	     * another thread might have modified the reference counts.
2275	     */
2276	    break;
2277	}
2278    } while (elm != NULL);
2279    errmsg_restore(saved_msg);
2280}
2281
2282/*
2283 * Call the initialization functions for each of the objects in
2284 * "list".  All of the objects are expected to have non-NULL init
2285 * functions.
2286 */
2287static void
2288objlist_call_init(Objlist *list, RtldLockState *lockstate)
2289{
2290    Objlist_Entry *elm;
2291    Obj_Entry *obj;
2292    char *saved_msg;
2293    Elf_Addr *init_addr;
2294    int index;
2295
2296    /*
2297     * Clean init_scanned flag so that objects can be rechecked and
2298     * possibly initialized earlier if any of vectors called below
2299     * cause the change by using dlopen.
2300     */
2301    for (obj = obj_list;  obj != NULL;  obj = obj->next)
2302	obj->init_scanned = false;
2303
2304    /*
2305     * Preserve the current error message since an init function might
2306     * call into the dynamic linker and overwrite it.
2307     */
2308    saved_msg = errmsg_save();
2309    STAILQ_FOREACH(elm, list, link) {
2310	if (elm->obj->init_done) /* Initialized early. */
2311	    continue;
2312	/*
2313	 * Race: other thread might try to use this object before current
2314	 * one completes the initilization. Not much can be done here
2315	 * without better locking.
2316	 */
2317	elm->obj->init_done = true;
2318	lock_release(rtld_bind_lock, lockstate);
2319
2320        /*
2321         * It is legal to have both DT_INIT and DT_INIT_ARRAY defined.
2322         * When this happens, DT_INIT is processed first.
2323         */
2324	if (elm->obj->init != (Elf_Addr)NULL) {
2325	    dbg("calling init function for %s at %p", elm->obj->path,
2326	        (void *)elm->obj->init);
2327	    LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init,
2328	        0, 0, elm->obj->path);
2329	    call_initfini_pointer(elm->obj, elm->obj->init);
2330	}
2331	init_addr = (Elf_Addr *)elm->obj->init_array;
2332	if (init_addr != NULL) {
2333	    for (index = 0; index < elm->obj->init_array_num; index++) {
2334		if (init_addr[index] != 0 && init_addr[index] != 1) {
2335		    dbg("calling init function for %s at %p", elm->obj->path,
2336			(void *)init_addr[index]);
2337		    LD_UTRACE(UTRACE_INIT_CALL, elm->obj,
2338			(void *)init_addr[index], 0, 0, elm->obj->path);
2339		    call_init_pointer(elm->obj, init_addr[index]);
2340		}
2341	    }
2342	}
2343	wlock_acquire(rtld_bind_lock, lockstate);
2344    }
2345    errmsg_restore(saved_msg);
2346}
2347
2348static void
2349objlist_clear(Objlist *list)
2350{
2351    Objlist_Entry *elm;
2352
2353    while (!STAILQ_EMPTY(list)) {
2354	elm = STAILQ_FIRST(list);
2355	STAILQ_REMOVE_HEAD(list, link);
2356	free(elm);
2357    }
2358}
2359
2360static Objlist_Entry *
2361objlist_find(Objlist *list, const Obj_Entry *obj)
2362{
2363    Objlist_Entry *elm;
2364
2365    STAILQ_FOREACH(elm, list, link)
2366	if (elm->obj == obj)
2367	    return elm;
2368    return NULL;
2369}
2370
2371static void
2372objlist_init(Objlist *list)
2373{
2374    STAILQ_INIT(list);
2375}
2376
2377static void
2378objlist_push_head(Objlist *list, Obj_Entry *obj)
2379{
2380    Objlist_Entry *elm;
2381
2382    elm = NEW(Objlist_Entry);
2383    elm->obj = obj;
2384    STAILQ_INSERT_HEAD(list, elm, link);
2385}
2386
2387static void
2388objlist_push_tail(Objlist *list, Obj_Entry *obj)
2389{
2390    Objlist_Entry *elm;
2391
2392    elm = NEW(Objlist_Entry);
2393    elm->obj = obj;
2394    STAILQ_INSERT_TAIL(list, elm, link);
2395}
2396
2397static void
2398objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj)
2399{
2400	Objlist_Entry *elm, *listelm;
2401
2402	STAILQ_FOREACH(listelm, list, link) {
2403		if (listelm->obj == listobj)
2404			break;
2405	}
2406	elm = NEW(Objlist_Entry);
2407	elm->obj = obj;
2408	if (listelm != NULL)
2409		STAILQ_INSERT_AFTER(list, listelm, elm, link);
2410	else
2411		STAILQ_INSERT_TAIL(list, elm, link);
2412}
2413
2414static void
2415objlist_remove(Objlist *list, Obj_Entry *obj)
2416{
2417    Objlist_Entry *elm;
2418
2419    if ((elm = objlist_find(list, obj)) != NULL) {
2420	STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2421	free(elm);
2422    }
2423}
2424
2425/*
2426 * Relocate dag rooted in the specified object.
2427 * Returns 0 on success, or -1 on failure.
2428 */
2429
2430static int
2431relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj,
2432    int flags, RtldLockState *lockstate)
2433{
2434	Objlist_Entry *elm;
2435	int error;
2436
2437	error = 0;
2438	STAILQ_FOREACH(elm, &root->dagmembers, link) {
2439		error = relocate_object(elm->obj, bind_now, rtldobj, flags,
2440		    lockstate);
2441		if (error == -1)
2442			break;
2443	}
2444	return (error);
2445}
2446
2447/*
2448 * Relocate single object.
2449 * Returns 0 on success, or -1 on failure.
2450 */
2451static int
2452relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
2453    int flags, RtldLockState *lockstate)
2454{
2455
2456	if (obj->relocated)
2457		return (0);
2458	obj->relocated = true;
2459	if (obj != rtldobj)
2460		dbg("relocating \"%s\"", obj->path);
2461
2462	if (obj->symtab == NULL || obj->strtab == NULL ||
2463	    !(obj->valid_hash_sysv || obj->valid_hash_gnu)) {
2464		_rtld_error("%s: Shared object has no run-time symbol table",
2465			    obj->path);
2466		return (-1);
2467	}
2468
2469	if (obj->textrel) {
2470		/* There are relocations to the write-protected text segment. */
2471		if (mprotect(obj->mapbase, obj->textsize,
2472		    PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
2473			_rtld_error("%s: Cannot write-enable text segment: %s",
2474			    obj->path, rtld_strerror(errno));
2475			return (-1);
2476		}
2477	}
2478
2479	/* Process the non-PLT non-IFUNC relocations. */
2480	if (reloc_non_plt(obj, rtldobj, flags, lockstate))
2481		return (-1);
2482
2483	if (obj->textrel) {	/* Re-protected the text segment. */
2484		if (mprotect(obj->mapbase, obj->textsize,
2485		    PROT_READ|PROT_EXEC) == -1) {
2486			_rtld_error("%s: Cannot write-protect text segment: %s",
2487			    obj->path, rtld_strerror(errno));
2488			return (-1);
2489		}
2490	}
2491
2492	/* Set the special PLT or GOT entries. */
2493	init_pltgot(obj);
2494
2495	/* Process the PLT relocations. */
2496	if (reloc_plt(obj) == -1)
2497		return (-1);
2498	/* Relocate the jump slots if we are doing immediate binding. */
2499	if (obj->bind_now || bind_now)
2500		if (reloc_jmpslots(obj, flags, lockstate) == -1)
2501			return (-1);
2502
2503	/*
2504	 * Process the non-PLT IFUNC relocations.  The relocations are
2505	 * processed in two phases, because IFUNC resolvers may
2506	 * reference other symbols, which must be readily processed
2507	 * before resolvers are called.
2508	 */
2509	if (obj->non_plt_gnu_ifunc &&
2510	    reloc_non_plt(obj, rtldobj, flags | SYMLOOK_IFUNC, lockstate))
2511		return (-1);
2512
2513	if (obj->relro_size > 0) {
2514		if (mprotect(obj->relro_page, obj->relro_size,
2515		    PROT_READ) == -1) {
2516			_rtld_error("%s: Cannot enforce relro protection: %s",
2517			    obj->path, rtld_strerror(errno));
2518			return (-1);
2519		}
2520	}
2521
2522	/*
2523	 * Set up the magic number and version in the Obj_Entry.  These
2524	 * were checked in the crt1.o from the original ElfKit, so we
2525	 * set them for backward compatibility.
2526	 */
2527	obj->magic = RTLD_MAGIC;
2528	obj->version = RTLD_VERSION;
2529
2530	return (0);
2531}
2532
2533/*
2534 * Relocate newly-loaded shared objects.  The argument is a pointer to
2535 * the Obj_Entry for the first such object.  All objects from the first
2536 * to the end of the list of objects are relocated.  Returns 0 on success,
2537 * or -1 on failure.
2538 */
2539static int
2540relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
2541    int flags, RtldLockState *lockstate)
2542{
2543	Obj_Entry *obj;
2544	int error;
2545
2546	for (error = 0, obj = first;  obj != NULL;  obj = obj->next) {
2547		error = relocate_object(obj, bind_now, rtldobj, flags,
2548		    lockstate);
2549		if (error == -1)
2550			break;
2551	}
2552	return (error);
2553}
2554
2555/*
2556 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots
2557 * referencing STT_GNU_IFUNC symbols is postponed till the other
2558 * relocations are done.  The indirect functions specified as
2559 * ifunc are allowed to call other symbols, so we need to have
2560 * objects relocated before asking for resolution from indirects.
2561 *
2562 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion,
2563 * instead of the usual lazy handling of PLT slots.  It is
2564 * consistent with how GNU does it.
2565 */
2566static int
2567resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags,
2568    RtldLockState *lockstate)
2569{
2570	if (obj->irelative && reloc_iresolve(obj, lockstate) == -1)
2571		return (-1);
2572	if ((obj->bind_now || bind_now) && obj->gnu_ifunc &&
2573	    reloc_gnu_ifunc(obj, flags, lockstate) == -1)
2574		return (-1);
2575	return (0);
2576}
2577
2578static int
2579resolve_objects_ifunc(Obj_Entry *first, bool bind_now, int flags,
2580    RtldLockState *lockstate)
2581{
2582	Obj_Entry *obj;
2583
2584	for (obj = first;  obj != NULL;  obj = obj->next) {
2585		if (resolve_object_ifunc(obj, bind_now, flags, lockstate) == -1)
2586			return (-1);
2587	}
2588	return (0);
2589}
2590
2591static int
2592initlist_objects_ifunc(Objlist *list, bool bind_now, int flags,
2593    RtldLockState *lockstate)
2594{
2595	Objlist_Entry *elm;
2596
2597	STAILQ_FOREACH(elm, list, link) {
2598		if (resolve_object_ifunc(elm->obj, bind_now, flags,
2599		    lockstate) == -1)
2600			return (-1);
2601	}
2602	return (0);
2603}
2604
2605/*
2606 * Cleanup procedure.  It will be called (by the atexit mechanism) just
2607 * before the process exits.
2608 */
2609static void
2610rtld_exit(void)
2611{
2612    RtldLockState lockstate;
2613
2614    wlock_acquire(rtld_bind_lock, &lockstate);
2615    dbg("rtld_exit()");
2616    objlist_call_fini(&list_fini, NULL, &lockstate);
2617    /* No need to remove the items from the list, since we are exiting. */
2618    if (!libmap_disable)
2619        lm_fini();
2620    lock_release(rtld_bind_lock, &lockstate);
2621}
2622
2623/*
2624 * Iterate over a search path, translate each element, and invoke the
2625 * callback on the result.
2626 */
2627static void *
2628path_enumerate(const char *path, path_enum_proc callback, void *arg)
2629{
2630    const char *trans;
2631    if (path == NULL)
2632	return (NULL);
2633
2634    path += strspn(path, ":;");
2635    while (*path != '\0') {
2636	size_t len;
2637	char  *res;
2638
2639	len = strcspn(path, ":;");
2640	trans = lm_findn(NULL, path, len);
2641	if (trans)
2642	    res = callback(trans, strlen(trans), arg);
2643	else
2644	    res = callback(path, len, arg);
2645
2646	if (res != NULL)
2647	    return (res);
2648
2649	path += len;
2650	path += strspn(path, ":;");
2651    }
2652
2653    return (NULL);
2654}
2655
2656struct try_library_args {
2657    const char	*name;
2658    size_t	 namelen;
2659    char	*buffer;
2660    size_t	 buflen;
2661};
2662
2663static void *
2664try_library_path(const char *dir, size_t dirlen, void *param)
2665{
2666    struct try_library_args *arg;
2667
2668    arg = param;
2669    if (*dir == '/' || trust) {
2670	char *pathname;
2671
2672	if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
2673		return (NULL);
2674
2675	pathname = arg->buffer;
2676	strncpy(pathname, dir, dirlen);
2677	pathname[dirlen] = '/';
2678	strcpy(pathname + dirlen + 1, arg->name);
2679
2680	dbg("  Trying \"%s\"", pathname);
2681	if (access(pathname, F_OK) == 0) {		/* We found it */
2682	    pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
2683	    strcpy(pathname, arg->buffer);
2684	    return (pathname);
2685	}
2686    }
2687    return (NULL);
2688}
2689
2690static char *
2691search_library_path(const char *name, const char *path)
2692{
2693    char *p;
2694    struct try_library_args arg;
2695
2696    if (path == NULL)
2697	return NULL;
2698
2699    arg.name = name;
2700    arg.namelen = strlen(name);
2701    arg.buffer = xmalloc(PATH_MAX);
2702    arg.buflen = PATH_MAX;
2703
2704    p = path_enumerate(path, try_library_path, &arg);
2705
2706    free(arg.buffer);
2707
2708    return (p);
2709}
2710
2711int
2712dlclose(void *handle)
2713{
2714    Obj_Entry *root;
2715    RtldLockState lockstate;
2716
2717    wlock_acquire(rtld_bind_lock, &lockstate);
2718    root = dlcheck(handle);
2719    if (root == NULL) {
2720	lock_release(rtld_bind_lock, &lockstate);
2721	return -1;
2722    }
2723    LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
2724	root->path);
2725
2726    /* Unreference the object and its dependencies. */
2727    root->dl_refcount--;
2728
2729    if (root->refcount == 1) {
2730	/*
2731	 * The object will be no longer referenced, so we must unload it.
2732	 * First, call the fini functions.
2733	 */
2734	objlist_call_fini(&list_fini, root, &lockstate);
2735
2736	unref_dag(root);
2737
2738	/* Finish cleaning up the newly-unreferenced objects. */
2739	GDB_STATE(RT_DELETE,&root->linkmap);
2740	unload_object(root);
2741	GDB_STATE(RT_CONSISTENT,NULL);
2742    } else
2743	unref_dag(root);
2744
2745    LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
2746    lock_release(rtld_bind_lock, &lockstate);
2747    return 0;
2748}
2749
2750char *
2751dlerror(void)
2752{
2753    char *msg = error_message;
2754    error_message = NULL;
2755    return msg;
2756}
2757
2758/*
2759 * This function is deprecated and has no effect.
2760 */
2761void
2762dllockinit(void *context,
2763	   void *(*lock_create)(void *context),
2764           void (*rlock_acquire)(void *lock),
2765           void (*wlock_acquire)(void *lock),
2766           void (*lock_release)(void *lock),
2767           void (*lock_destroy)(void *lock),
2768	   void (*context_destroy)(void *context))
2769{
2770    static void *cur_context;
2771    static void (*cur_context_destroy)(void *);
2772
2773    /* Just destroy the context from the previous call, if necessary. */
2774    if (cur_context_destroy != NULL)
2775	cur_context_destroy(cur_context);
2776    cur_context = context;
2777    cur_context_destroy = context_destroy;
2778}
2779
2780void *
2781dlopen(const char *name, int mode)
2782{
2783
2784	return (rtld_dlopen(name, -1, mode));
2785}
2786
2787void *
2788fdlopen(int fd, int mode)
2789{
2790
2791	return (rtld_dlopen(NULL, fd, mode));
2792}
2793
2794static void *
2795rtld_dlopen(const char *name, int fd, int mode)
2796{
2797    RtldLockState lockstate;
2798    int lo_flags;
2799
2800    LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
2801    ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
2802    if (ld_tracing != NULL) {
2803	rlock_acquire(rtld_bind_lock, &lockstate);
2804	if (sigsetjmp(lockstate.env, 0) != 0)
2805	    lock_upgrade(rtld_bind_lock, &lockstate);
2806	environ = (char **)*get_program_var_addr("environ", &lockstate);
2807	lock_release(rtld_bind_lock, &lockstate);
2808    }
2809    lo_flags = RTLD_LO_DLOPEN;
2810    if (mode & RTLD_NODELETE)
2811	    lo_flags |= RTLD_LO_NODELETE;
2812    if (mode & RTLD_NOLOAD)
2813	    lo_flags |= RTLD_LO_NOLOAD;
2814    if (ld_tracing != NULL)
2815	    lo_flags |= RTLD_LO_TRACE;
2816
2817    return (dlopen_object(name, fd, obj_main, lo_flags,
2818      mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL));
2819}
2820
2821static void
2822dlopen_cleanup(Obj_Entry *obj)
2823{
2824
2825	obj->dl_refcount--;
2826	unref_dag(obj);
2827	if (obj->refcount == 0)
2828		unload_object(obj);
2829}
2830
2831static Obj_Entry *
2832dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags,
2833    int mode, RtldLockState *lockstate)
2834{
2835    Obj_Entry **old_obj_tail;
2836    Obj_Entry *obj;
2837    Objlist initlist;
2838    RtldLockState mlockstate;
2839    int result;
2840
2841    objlist_init(&initlist);
2842
2843    if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) {
2844	wlock_acquire(rtld_bind_lock, &mlockstate);
2845	lockstate = &mlockstate;
2846    }
2847    GDB_STATE(RT_ADD,NULL);
2848
2849    old_obj_tail = obj_tail;
2850    obj = NULL;
2851    if (name == NULL && fd == -1) {
2852	obj = obj_main;
2853	obj->refcount++;
2854    } else {
2855	obj = load_object(name, fd, refobj, lo_flags);
2856    }
2857
2858    if (obj) {
2859	obj->dl_refcount++;
2860	if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
2861	    objlist_push_tail(&list_global, obj);
2862	if (*old_obj_tail != NULL) {		/* We loaded something new. */
2863	    assert(*old_obj_tail == obj);
2864	    result = load_needed_objects(obj,
2865		lo_flags & (RTLD_LO_DLOPEN | RTLD_LO_EARLY));
2866	    init_dag(obj);
2867	    ref_dag(obj);
2868	    if (result != -1)
2869		result = rtld_verify_versions(&obj->dagmembers);
2870	    if (result != -1 && ld_tracing)
2871		goto trace;
2872	    if (result == -1 || relocate_object_dag(obj,
2873	      (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld,
2874	      (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
2875	      lockstate) == -1) {
2876		dlopen_cleanup(obj);
2877		obj = NULL;
2878	    } else if (lo_flags & RTLD_LO_EARLY) {
2879		/*
2880		 * Do not call the init functions for early loaded
2881		 * filtees.  The image is still not initialized enough
2882		 * for them to work.
2883		 *
2884		 * Our object is found by the global object list and
2885		 * will be ordered among all init calls done right
2886		 * before transferring control to main.
2887		 */
2888	    } else {
2889		/* Make list of init functions to call. */
2890		initlist_add_objects(obj, &obj->next, &initlist);
2891	    }
2892	    /*
2893	     * Process all no_delete objects here, given them own
2894	     * DAGs to prevent their dependencies from being unloaded.
2895	     * This has to be done after we have loaded all of the
2896	     * dependencies, so that we do not miss any.
2897	     */
2898	    if (obj != NULL)
2899		process_nodelete(obj);
2900	} else {
2901	    /*
2902	     * Bump the reference counts for objects on this DAG.  If
2903	     * this is the first dlopen() call for the object that was
2904	     * already loaded as a dependency, initialize the dag
2905	     * starting at it.
2906	     */
2907	    init_dag(obj);
2908	    ref_dag(obj);
2909
2910	    if ((lo_flags & RTLD_LO_TRACE) != 0)
2911		goto trace;
2912	}
2913	if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
2914	  obj->z_nodelete) && !obj->ref_nodel) {
2915	    dbg("obj %s nodelete", obj->path);
2916	    ref_dag(obj);
2917	    obj->z_nodelete = obj->ref_nodel = true;
2918	}
2919    }
2920
2921    LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
2922	name);
2923    GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
2924
2925    if (!(lo_flags & RTLD_LO_EARLY)) {
2926	map_stacks_exec(lockstate);
2927    }
2928
2929    if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW,
2930      (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
2931      lockstate) == -1) {
2932	objlist_clear(&initlist);
2933	dlopen_cleanup(obj);
2934	if (lockstate == &mlockstate)
2935	    lock_release(rtld_bind_lock, lockstate);
2936	return (NULL);
2937    }
2938
2939    if (!(lo_flags & RTLD_LO_EARLY)) {
2940	/* Call the init functions. */
2941	objlist_call_init(&initlist, lockstate);
2942    }
2943    objlist_clear(&initlist);
2944    if (lockstate == &mlockstate)
2945	lock_release(rtld_bind_lock, lockstate);
2946    return obj;
2947trace:
2948    trace_loaded_objects(obj);
2949    if (lockstate == &mlockstate)
2950	lock_release(rtld_bind_lock, lockstate);
2951    exit(0);
2952}
2953
2954static void *
2955do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
2956    int flags)
2957{
2958    DoneList donelist;
2959    const Obj_Entry *obj, *defobj;
2960    const Elf_Sym *def;
2961    SymLook req;
2962    RtldLockState lockstate;
2963#ifndef __ia64__
2964    tls_index ti;
2965#endif
2966    int res;
2967
2968    def = NULL;
2969    defobj = NULL;
2970    symlook_init(&req, name);
2971    req.ventry = ve;
2972    req.flags = flags | SYMLOOK_IN_PLT;
2973    req.lockstate = &lockstate;
2974
2975    rlock_acquire(rtld_bind_lock, &lockstate);
2976    if (sigsetjmp(lockstate.env, 0) != 0)
2977	    lock_upgrade(rtld_bind_lock, &lockstate);
2978    if (handle == NULL || handle == RTLD_NEXT ||
2979	handle == RTLD_DEFAULT || handle == RTLD_SELF) {
2980
2981	if ((obj = obj_from_addr(retaddr)) == NULL) {
2982	    _rtld_error("Cannot determine caller's shared object");
2983	    lock_release(rtld_bind_lock, &lockstate);
2984	    return NULL;
2985	}
2986	if (handle == NULL) {	/* Just the caller's shared object. */
2987	    res = symlook_obj(&req, obj);
2988	    if (res == 0) {
2989		def = req.sym_out;
2990		defobj = req.defobj_out;
2991	    }
2992	} else if (handle == RTLD_NEXT || /* Objects after caller's */
2993		   handle == RTLD_SELF) { /* ... caller included */
2994	    if (handle == RTLD_NEXT)
2995		obj = obj->next;
2996	    for (; obj != NULL; obj = obj->next) {
2997		res = symlook_obj(&req, obj);
2998		if (res == 0) {
2999		    if (def == NULL ||
3000		      ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) {
3001			def = req.sym_out;
3002			defobj = req.defobj_out;
3003			if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3004			    break;
3005		    }
3006		}
3007	    }
3008	    /*
3009	     * Search the dynamic linker itself, and possibly resolve the
3010	     * symbol from there.  This is how the application links to
3011	     * dynamic linker services such as dlopen.
3012	     */
3013	    if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3014		res = symlook_obj(&req, &obj_rtld);
3015		if (res == 0) {
3016		    def = req.sym_out;
3017		    defobj = req.defobj_out;
3018		}
3019	    }
3020	} else {
3021	    assert(handle == RTLD_DEFAULT);
3022	    res = symlook_default(&req, obj);
3023	    if (res == 0) {
3024		defobj = req.defobj_out;
3025		def = req.sym_out;
3026	    }
3027	}
3028    } else {
3029	if ((obj = dlcheck(handle)) == NULL) {
3030	    lock_release(rtld_bind_lock, &lockstate);
3031	    return NULL;
3032	}
3033
3034	donelist_init(&donelist);
3035	if (obj->mainprog) {
3036            /* Handle obtained by dlopen(NULL, ...) implies global scope. */
3037	    res = symlook_global(&req, &donelist);
3038	    if (res == 0) {
3039		def = req.sym_out;
3040		defobj = req.defobj_out;
3041	    }
3042	    /*
3043	     * Search the dynamic linker itself, and possibly resolve the
3044	     * symbol from there.  This is how the application links to
3045	     * dynamic linker services such as dlopen.
3046	     */
3047	    if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3048		res = symlook_obj(&req, &obj_rtld);
3049		if (res == 0) {
3050		    def = req.sym_out;
3051		    defobj = req.defobj_out;
3052		}
3053	    }
3054	}
3055	else {
3056	    /* Search the whole DAG rooted at the given object. */
3057	    res = symlook_list(&req, &obj->dagmembers, &donelist);
3058	    if (res == 0) {
3059		def = req.sym_out;
3060		defobj = req.defobj_out;
3061	    }
3062	}
3063    }
3064
3065    if (def != NULL) {
3066	lock_release(rtld_bind_lock, &lockstate);
3067
3068	/*
3069	 * The value required by the caller is derived from the value
3070	 * of the symbol. For the ia64 architecture, we need to
3071	 * construct a function descriptor which the caller can use to
3072	 * call the function with the right 'gp' value. For other
3073	 * architectures and for non-functions, the value is simply
3074	 * the relocated value of the symbol.
3075	 */
3076	if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
3077	    return (make_function_pointer(def, defobj));
3078	else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
3079	    return (rtld_resolve_ifunc(defobj, def));
3080	else if (ELF_ST_TYPE(def->st_info) == STT_TLS) {
3081#ifdef __ia64__
3082	    return (__tls_get_addr(defobj->tlsindex, def->st_value));
3083#else
3084	    ti.ti_module = defobj->tlsindex;
3085	    ti.ti_offset = def->st_value;
3086	    return (__tls_get_addr(&ti));
3087#endif
3088	} else
3089	    return (defobj->relocbase + def->st_value);
3090    }
3091
3092    _rtld_error("Undefined symbol \"%s\"", name);
3093    lock_release(rtld_bind_lock, &lockstate);
3094    return NULL;
3095}
3096
3097void *
3098dlsym(void *handle, const char *name)
3099{
3100	return do_dlsym(handle, name, __builtin_return_address(0), NULL,
3101	    SYMLOOK_DLSYM);
3102}
3103
3104dlfunc_t
3105dlfunc(void *handle, const char *name)
3106{
3107	union {
3108		void *d;
3109		dlfunc_t f;
3110	} rv;
3111
3112	rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
3113	    SYMLOOK_DLSYM);
3114	return (rv.f);
3115}
3116
3117void *
3118dlvsym(void *handle, const char *name, const char *version)
3119{
3120	Ver_Entry ventry;
3121
3122	ventry.name = version;
3123	ventry.file = NULL;
3124	ventry.hash = elf_hash(version);
3125	ventry.flags= 0;
3126	return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
3127	    SYMLOOK_DLSYM);
3128}
3129
3130int
3131_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
3132{
3133    const Obj_Entry *obj;
3134    RtldLockState lockstate;
3135
3136    rlock_acquire(rtld_bind_lock, &lockstate);
3137    obj = obj_from_addr(addr);
3138    if (obj == NULL) {
3139        _rtld_error("No shared object contains address");
3140	lock_release(rtld_bind_lock, &lockstate);
3141        return (0);
3142    }
3143    rtld_fill_dl_phdr_info(obj, phdr_info);
3144    lock_release(rtld_bind_lock, &lockstate);
3145    return (1);
3146}
3147
3148int
3149dladdr(const void *addr, Dl_info *info)
3150{
3151    const Obj_Entry *obj;
3152    const Elf_Sym *def;
3153    void *symbol_addr;
3154    unsigned long symoffset;
3155    RtldLockState lockstate;
3156
3157    rlock_acquire(rtld_bind_lock, &lockstate);
3158    obj = obj_from_addr(addr);
3159    if (obj == NULL) {
3160        _rtld_error("No shared object contains address");
3161	lock_release(rtld_bind_lock, &lockstate);
3162        return 0;
3163    }
3164    info->dli_fname = obj->path;
3165    info->dli_fbase = obj->mapbase;
3166    info->dli_saddr = (void *)0;
3167    info->dli_sname = NULL;
3168
3169    /*
3170     * Walk the symbol list looking for the symbol whose address is
3171     * closest to the address sent in.
3172     */
3173    for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) {
3174        def = obj->symtab + symoffset;
3175
3176        /*
3177         * For skip the symbol if st_shndx is either SHN_UNDEF or
3178         * SHN_COMMON.
3179         */
3180        if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
3181            continue;
3182
3183        /*
3184         * If the symbol is greater than the specified address, or if it
3185         * is further away from addr than the current nearest symbol,
3186         * then reject it.
3187         */
3188        symbol_addr = obj->relocbase + def->st_value;
3189        if (symbol_addr > addr || symbol_addr < info->dli_saddr)
3190            continue;
3191
3192        /* Update our idea of the nearest symbol. */
3193        info->dli_sname = obj->strtab + def->st_name;
3194        info->dli_saddr = symbol_addr;
3195
3196        /* Exact match? */
3197        if (info->dli_saddr == addr)
3198            break;
3199    }
3200    lock_release(rtld_bind_lock, &lockstate);
3201    return 1;
3202}
3203
3204int
3205dlinfo(void *handle, int request, void *p)
3206{
3207    const Obj_Entry *obj;
3208    RtldLockState lockstate;
3209    int error;
3210
3211    rlock_acquire(rtld_bind_lock, &lockstate);
3212
3213    if (handle == NULL || handle == RTLD_SELF) {
3214	void *retaddr;
3215
3216	retaddr = __builtin_return_address(0);	/* __GNUC__ only */
3217	if ((obj = obj_from_addr(retaddr)) == NULL)
3218	    _rtld_error("Cannot determine caller's shared object");
3219    } else
3220	obj = dlcheck(handle);
3221
3222    if (obj == NULL) {
3223	lock_release(rtld_bind_lock, &lockstate);
3224	return (-1);
3225    }
3226
3227    error = 0;
3228    switch (request) {
3229    case RTLD_DI_LINKMAP:
3230	*((struct link_map const **)p) = &obj->linkmap;
3231	break;
3232    case RTLD_DI_ORIGIN:
3233	error = rtld_dirname(obj->path, p);
3234	break;
3235
3236    case RTLD_DI_SERINFOSIZE:
3237    case RTLD_DI_SERINFO:
3238	error = do_search_info(obj, request, (struct dl_serinfo *)p);
3239	break;
3240
3241    default:
3242	_rtld_error("Invalid request %d passed to dlinfo()", request);
3243	error = -1;
3244    }
3245
3246    lock_release(rtld_bind_lock, &lockstate);
3247
3248    return (error);
3249}
3250
3251static void
3252rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
3253{
3254
3255	phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
3256	phdr_info->dlpi_name = obj->path;
3257	phdr_info->dlpi_phdr = obj->phdr;
3258	phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
3259	phdr_info->dlpi_tls_modid = obj->tlsindex;
3260	phdr_info->dlpi_tls_data = obj->tlsinit;
3261	phdr_info->dlpi_adds = obj_loads;
3262	phdr_info->dlpi_subs = obj_loads - obj_count;
3263}
3264
3265int
3266dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
3267{
3268    struct dl_phdr_info phdr_info;
3269    const Obj_Entry *obj;
3270    RtldLockState bind_lockstate, phdr_lockstate;
3271    int error;
3272
3273    wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
3274    rlock_acquire(rtld_bind_lock, &bind_lockstate);
3275
3276    error = 0;
3277
3278    for (obj = obj_list;  obj != NULL;  obj = obj->next) {
3279	rtld_fill_dl_phdr_info(obj, &phdr_info);
3280	if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0)
3281		break;
3282
3283    }
3284    lock_release(rtld_bind_lock, &bind_lockstate);
3285    lock_release(rtld_phdr_lock, &phdr_lockstate);
3286
3287    return (error);
3288}
3289
3290static void *
3291fill_search_info(const char *dir, size_t dirlen, void *param)
3292{
3293    struct fill_search_info_args *arg;
3294
3295    arg = param;
3296
3297    if (arg->request == RTLD_DI_SERINFOSIZE) {
3298	arg->serinfo->dls_cnt ++;
3299	arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1;
3300    } else {
3301	struct dl_serpath *s_entry;
3302
3303	s_entry = arg->serpath;
3304	s_entry->dls_name  = arg->strspace;
3305	s_entry->dls_flags = arg->flags;
3306
3307	strncpy(arg->strspace, dir, dirlen);
3308	arg->strspace[dirlen] = '\0';
3309
3310	arg->strspace += dirlen + 1;
3311	arg->serpath++;
3312    }
3313
3314    return (NULL);
3315}
3316
3317static int
3318do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
3319{
3320    struct dl_serinfo _info;
3321    struct fill_search_info_args args;
3322
3323    args.request = RTLD_DI_SERINFOSIZE;
3324    args.serinfo = &_info;
3325
3326    _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
3327    _info.dls_cnt  = 0;
3328
3329    path_enumerate(obj->rpath, fill_search_info, &args);
3330    path_enumerate(ld_library_path, fill_search_info, &args);
3331    path_enumerate(obj->runpath, fill_search_info, &args);
3332    path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args);
3333    if (!obj->z_nodeflib)
3334      path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
3335
3336
3337    if (request == RTLD_DI_SERINFOSIZE) {
3338	info->dls_size = _info.dls_size;
3339	info->dls_cnt = _info.dls_cnt;
3340	return (0);
3341    }
3342
3343    if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
3344	_rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
3345	return (-1);
3346    }
3347
3348    args.request  = RTLD_DI_SERINFO;
3349    args.serinfo  = info;
3350    args.serpath  = &info->dls_serpath[0];
3351    args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
3352
3353    args.flags = LA_SER_RUNPATH;
3354    if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
3355	return (-1);
3356
3357    args.flags = LA_SER_LIBPATH;
3358    if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
3359	return (-1);
3360
3361    args.flags = LA_SER_RUNPATH;
3362    if (path_enumerate(obj->runpath, fill_search_info, &args) != NULL)
3363	return (-1);
3364
3365    args.flags = LA_SER_CONFIG;
3366    if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, &args)
3367      != NULL)
3368	return (-1);
3369
3370    args.flags = LA_SER_DEFAULT;
3371    if (!obj->z_nodeflib &&
3372      path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
3373	return (-1);
3374    return (0);
3375}
3376
3377static int
3378rtld_dirname(const char *path, char *bname)
3379{
3380    const char *endp;
3381
3382    /* Empty or NULL string gets treated as "." */
3383    if (path == NULL || *path == '\0') {
3384	bname[0] = '.';
3385	bname[1] = '\0';
3386	return (0);
3387    }
3388
3389    /* Strip trailing slashes */
3390    endp = path + strlen(path) - 1;
3391    while (endp > path && *endp == '/')
3392	endp--;
3393
3394    /* Find the start of the dir */
3395    while (endp > path && *endp != '/')
3396	endp--;
3397
3398    /* Either the dir is "/" or there are no slashes */
3399    if (endp == path) {
3400	bname[0] = *endp == '/' ? '/' : '.';
3401	bname[1] = '\0';
3402	return (0);
3403    } else {
3404	do {
3405	    endp--;
3406	} while (endp > path && *endp == '/');
3407    }
3408
3409    if (endp - path + 2 > PATH_MAX)
3410    {
3411	_rtld_error("Filename is too long: %s", path);
3412	return(-1);
3413    }
3414
3415    strncpy(bname, path, endp - path + 1);
3416    bname[endp - path + 1] = '\0';
3417    return (0);
3418}
3419
3420static int
3421rtld_dirname_abs(const char *path, char *base)
3422{
3423	char base_rel[PATH_MAX];
3424
3425	if (rtld_dirname(path, base) == -1)
3426		return (-1);
3427	if (base[0] == '/')
3428		return (0);
3429	if (getcwd(base_rel, sizeof(base_rel)) == NULL ||
3430	    strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) ||
3431	    strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel))
3432		return (-1);
3433	strcpy(base, base_rel);
3434	return (0);
3435}
3436
3437static void
3438linkmap_add(Obj_Entry *obj)
3439{
3440    struct link_map *l = &obj->linkmap;
3441    struct link_map *prev;
3442
3443    obj->linkmap.l_name = obj->path;
3444    obj->linkmap.l_addr = obj->mapbase;
3445    obj->linkmap.l_ld = obj->dynamic;
3446#ifdef __mips__
3447    /* GDB needs load offset on MIPS to use the symbols */
3448    obj->linkmap.l_offs = obj->relocbase;
3449#endif
3450
3451    if (r_debug.r_map == NULL) {
3452	r_debug.r_map = l;
3453	return;
3454    }
3455
3456    /*
3457     * Scan to the end of the list, but not past the entry for the
3458     * dynamic linker, which we want to keep at the very end.
3459     */
3460    for (prev = r_debug.r_map;
3461      prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
3462      prev = prev->l_next)
3463	;
3464
3465    /* Link in the new entry. */
3466    l->l_prev = prev;
3467    l->l_next = prev->l_next;
3468    if (l->l_next != NULL)
3469	l->l_next->l_prev = l;
3470    prev->l_next = l;
3471}
3472
3473static void
3474linkmap_delete(Obj_Entry *obj)
3475{
3476    struct link_map *l = &obj->linkmap;
3477
3478    if (l->l_prev == NULL) {
3479	if ((r_debug.r_map = l->l_next) != NULL)
3480	    l->l_next->l_prev = NULL;
3481	return;
3482    }
3483
3484    if ((l->l_prev->l_next = l->l_next) != NULL)
3485	l->l_next->l_prev = l->l_prev;
3486}
3487
3488/*
3489 * Function for the debugger to set a breakpoint on to gain control.
3490 *
3491 * The two parameters allow the debugger to easily find and determine
3492 * what the runtime loader is doing and to whom it is doing it.
3493 *
3494 * When the loadhook trap is hit (r_debug_state, set at program
3495 * initialization), the arguments can be found on the stack:
3496 *
3497 *  +8   struct link_map *m
3498 *  +4   struct r_debug  *rd
3499 *  +0   RetAddr
3500 */
3501void
3502r_debug_state(struct r_debug* rd, struct link_map *m)
3503{
3504    /*
3505     * The following is a hack to force the compiler to emit calls to
3506     * this function, even when optimizing.  If the function is empty,
3507     * the compiler is not obliged to emit any code for calls to it,
3508     * even when marked __noinline.  However, gdb depends on those
3509     * calls being made.
3510     */
3511    __compiler_membar();
3512}
3513
3514/*
3515 * A function called after init routines have completed. This can be used to
3516 * break before a program's entry routine is called, and can be used when
3517 * main is not available in the symbol table.
3518 */
3519void
3520_r_debug_postinit(struct link_map *m)
3521{
3522
3523	/* See r_debug_state(). */
3524	__compiler_membar();
3525}
3526
3527/*
3528 * Get address of the pointer variable in the main program.
3529 * Prefer non-weak symbol over the weak one.
3530 */
3531static const void **
3532get_program_var_addr(const char *name, RtldLockState *lockstate)
3533{
3534    SymLook req;
3535    DoneList donelist;
3536
3537    symlook_init(&req, name);
3538    req.lockstate = lockstate;
3539    donelist_init(&donelist);
3540    if (symlook_global(&req, &donelist) != 0)
3541	return (NULL);
3542    if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC)
3543	return ((const void **)make_function_pointer(req.sym_out,
3544	  req.defobj_out));
3545    else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC)
3546	return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out));
3547    else
3548	return ((const void **)(req.defobj_out->relocbase +
3549	  req.sym_out->st_value));
3550}
3551
3552/*
3553 * Set a pointer variable in the main program to the given value.  This
3554 * is used to set key variables such as "environ" before any of the
3555 * init functions are called.
3556 */
3557static void
3558set_program_var(const char *name, const void *value)
3559{
3560    const void **addr;
3561
3562    if ((addr = get_program_var_addr(name, NULL)) != NULL) {
3563	dbg("\"%s\": *%p <-- %p", name, addr, value);
3564	*addr = value;
3565    }
3566}
3567
3568/*
3569 * Search the global objects, including dependencies and main object,
3570 * for the given symbol.
3571 */
3572static int
3573symlook_global(SymLook *req, DoneList *donelist)
3574{
3575    SymLook req1;
3576    const Objlist_Entry *elm;
3577    int res;
3578
3579    symlook_init_from_req(&req1, req);
3580
3581    /* Search all objects loaded at program start up. */
3582    if (req->defobj_out == NULL ||
3583      ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
3584	res = symlook_list(&req1, &list_main, donelist);
3585	if (res == 0 && (req->defobj_out == NULL ||
3586	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3587	    req->sym_out = req1.sym_out;
3588	    req->defobj_out = req1.defobj_out;
3589	    assert(req->defobj_out != NULL);
3590	}
3591    }
3592
3593    /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
3594    STAILQ_FOREACH(elm, &list_global, link) {
3595	if (req->defobj_out != NULL &&
3596	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
3597	    break;
3598	res = symlook_list(&req1, &elm->obj->dagmembers, donelist);
3599	if (res == 0 && (req->defobj_out == NULL ||
3600	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3601	    req->sym_out = req1.sym_out;
3602	    req->defobj_out = req1.defobj_out;
3603	    assert(req->defobj_out != NULL);
3604	}
3605    }
3606
3607    return (req->sym_out != NULL ? 0 : ESRCH);
3608}
3609
3610/*
3611 * Given a symbol name in a referencing object, find the corresponding
3612 * definition of the symbol.  Returns a pointer to the symbol, or NULL if
3613 * no definition was found.  Returns a pointer to the Obj_Entry of the
3614 * defining object via the reference parameter DEFOBJ_OUT.
3615 */
3616static int
3617symlook_default(SymLook *req, const Obj_Entry *refobj)
3618{
3619    DoneList donelist;
3620    const Objlist_Entry *elm;
3621    SymLook req1;
3622    int res;
3623
3624    donelist_init(&donelist);
3625    symlook_init_from_req(&req1, req);
3626
3627    /* Look first in the referencing object if linked symbolically. */
3628    if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
3629	res = symlook_obj(&req1, refobj);
3630	if (res == 0) {
3631	    req->sym_out = req1.sym_out;
3632	    req->defobj_out = req1.defobj_out;
3633	    assert(req->defobj_out != NULL);
3634	}
3635    }
3636
3637    symlook_global(req, &donelist);
3638
3639    /* Search all dlopened DAGs containing the referencing object. */
3640    STAILQ_FOREACH(elm, &refobj->dldags, link) {
3641	if (req->sym_out != NULL &&
3642	  ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
3643	    break;
3644	res = symlook_list(&req1, &elm->obj->dagmembers, &donelist);
3645	if (res == 0 && (req->sym_out == NULL ||
3646	  ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3647	    req->sym_out = req1.sym_out;
3648	    req->defobj_out = req1.defobj_out;
3649	    assert(req->defobj_out != NULL);
3650	}
3651    }
3652
3653    /*
3654     * Search the dynamic linker itself, and possibly resolve the
3655     * symbol from there.  This is how the application links to
3656     * dynamic linker services such as dlopen.
3657     */
3658    if (req->sym_out == NULL ||
3659      ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
3660	res = symlook_obj(&req1, &obj_rtld);
3661	if (res == 0) {
3662	    req->sym_out = req1.sym_out;
3663	    req->defobj_out = req1.defobj_out;
3664	    assert(req->defobj_out != NULL);
3665	}
3666    }
3667
3668    return (req->sym_out != NULL ? 0 : ESRCH);
3669}
3670
3671static int
3672symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp)
3673{
3674    const Elf_Sym *def;
3675    const Obj_Entry *defobj;
3676    const Objlist_Entry *elm;
3677    SymLook req1;
3678    int res;
3679
3680    def = NULL;
3681    defobj = NULL;
3682    STAILQ_FOREACH(elm, objlist, link) {
3683	if (donelist_check(dlp, elm->obj))
3684	    continue;
3685	symlook_init_from_req(&req1, req);
3686	if ((res = symlook_obj(&req1, elm->obj)) == 0) {
3687	    if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
3688		def = req1.sym_out;
3689		defobj = req1.defobj_out;
3690		if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3691		    break;
3692	    }
3693	}
3694    }
3695    if (def != NULL) {
3696	req->sym_out = def;
3697	req->defobj_out = defobj;
3698	return (0);
3699    }
3700    return (ESRCH);
3701}
3702
3703/*
3704 * Search the chain of DAGS cointed to by the given Needed_Entry
3705 * for a symbol of the given name.  Each DAG is scanned completely
3706 * before advancing to the next one.  Returns a pointer to the symbol,
3707 * or NULL if no definition was found.
3708 */
3709static int
3710symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp)
3711{
3712    const Elf_Sym *def;
3713    const Needed_Entry *n;
3714    const Obj_Entry *defobj;
3715    SymLook req1;
3716    int res;
3717
3718    def = NULL;
3719    defobj = NULL;
3720    symlook_init_from_req(&req1, req);
3721    for (n = needed; n != NULL; n = n->next) {
3722	if (n->obj == NULL ||
3723	    (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0)
3724	    continue;
3725	if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
3726	    def = req1.sym_out;
3727	    defobj = req1.defobj_out;
3728	    if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3729		break;
3730	}
3731    }
3732    if (def != NULL) {
3733	req->sym_out = def;
3734	req->defobj_out = defobj;
3735	return (0);
3736    }
3737    return (ESRCH);
3738}
3739
3740/*
3741 * Search the symbol table of a single shared object for a symbol of
3742 * the given name and version, if requested.  Returns a pointer to the
3743 * symbol, or NULL if no definition was found.  If the object is
3744 * filter, return filtered symbol from filtee.
3745 *
3746 * The symbol's hash value is passed in for efficiency reasons; that
3747 * eliminates many recomputations of the hash value.
3748 */
3749int
3750symlook_obj(SymLook *req, const Obj_Entry *obj)
3751{
3752    DoneList donelist;
3753    SymLook req1;
3754    int flags, res, mres;
3755
3756    /*
3757     * If there is at least one valid hash at this point, we prefer to
3758     * use the faster GNU version if available.
3759     */
3760    if (obj->valid_hash_gnu)
3761	mres = symlook_obj1_gnu(req, obj);
3762    else if (obj->valid_hash_sysv)
3763	mres = symlook_obj1_sysv(req, obj);
3764    else
3765	return (EINVAL);
3766
3767    if (mres == 0) {
3768	if (obj->needed_filtees != NULL) {
3769	    flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
3770	    load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
3771	    donelist_init(&donelist);
3772	    symlook_init_from_req(&req1, req);
3773	    res = symlook_needed(&req1, obj->needed_filtees, &donelist);
3774	    if (res == 0) {
3775		req->sym_out = req1.sym_out;
3776		req->defobj_out = req1.defobj_out;
3777	    }
3778	    return (res);
3779	}
3780	if (obj->needed_aux_filtees != NULL) {
3781	    flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
3782	    load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
3783	    donelist_init(&donelist);
3784	    symlook_init_from_req(&req1, req);
3785	    res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist);
3786	    if (res == 0) {
3787		req->sym_out = req1.sym_out;
3788		req->defobj_out = req1.defobj_out;
3789		return (res);
3790	    }
3791	}
3792    }
3793    return (mres);
3794}
3795
3796/* Symbol match routine common to both hash functions */
3797static bool
3798matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result,
3799    const unsigned long symnum)
3800{
3801	Elf_Versym verndx;
3802	const Elf_Sym *symp;
3803	const char *strp;
3804
3805	symp = obj->symtab + symnum;
3806	strp = obj->strtab + symp->st_name;
3807
3808	switch (ELF_ST_TYPE(symp->st_info)) {
3809	case STT_FUNC:
3810	case STT_NOTYPE:
3811	case STT_OBJECT:
3812	case STT_COMMON:
3813	case STT_GNU_IFUNC:
3814		if (symp->st_value == 0)
3815			return (false);
3816		/* fallthrough */
3817	case STT_TLS:
3818		if (symp->st_shndx != SHN_UNDEF)
3819			break;
3820#ifndef __mips__
3821		else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
3822		    (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
3823			break;
3824		/* fallthrough */
3825#endif
3826	default:
3827		return (false);
3828	}
3829	if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0)
3830		return (false);
3831
3832	if (req->ventry == NULL) {
3833		if (obj->versyms != NULL) {
3834			verndx = VER_NDX(obj->versyms[symnum]);
3835			if (verndx > obj->vernum) {
3836				_rtld_error(
3837				    "%s: symbol %s references wrong version %d",
3838				    obj->path, obj->strtab + symnum, verndx);
3839				return (false);
3840			}
3841			/*
3842			 * If we are not called from dlsym (i.e. this
3843			 * is a normal relocation from unversioned
3844			 * binary), accept the symbol immediately if
3845			 * it happens to have first version after this
3846			 * shared object became versioned.  Otherwise,
3847			 * if symbol is versioned and not hidden,
3848			 * remember it. If it is the only symbol with
3849			 * this name exported by the shared object, it
3850			 * will be returned as a match by the calling
3851			 * function. If symbol is global (verndx < 2)
3852			 * accept it unconditionally.
3853			 */
3854			if ((req->flags & SYMLOOK_DLSYM) == 0 &&
3855			    verndx == VER_NDX_GIVEN) {
3856				result->sym_out = symp;
3857				return (true);
3858			}
3859			else if (verndx >= VER_NDX_GIVEN) {
3860				if ((obj->versyms[symnum] & VER_NDX_HIDDEN)
3861				    == 0) {
3862					if (result->vsymp == NULL)
3863						result->vsymp = symp;
3864					result->vcount++;
3865				}
3866				return (false);
3867			}
3868		}
3869		result->sym_out = symp;
3870		return (true);
3871	}
3872	if (obj->versyms == NULL) {
3873		if (object_match_name(obj, req->ventry->name)) {
3874			_rtld_error("%s: object %s should provide version %s "
3875			    "for symbol %s", obj_rtld.path, obj->path,
3876			    req->ventry->name, obj->strtab + symnum);
3877			return (false);
3878		}
3879	} else {
3880		verndx = VER_NDX(obj->versyms[symnum]);
3881		if (verndx > obj->vernum) {
3882			_rtld_error("%s: symbol %s references wrong version %d",
3883			    obj->path, obj->strtab + symnum, verndx);
3884			return (false);
3885		}
3886		if (obj->vertab[verndx].hash != req->ventry->hash ||
3887		    strcmp(obj->vertab[verndx].name, req->ventry->name)) {
3888			/*
3889			 * Version does not match. Look if this is a
3890			 * global symbol and if it is not hidden. If
3891			 * global symbol (verndx < 2) is available,
3892			 * use it. Do not return symbol if we are
3893			 * called by dlvsym, because dlvsym looks for
3894			 * a specific version and default one is not
3895			 * what dlvsym wants.
3896			 */
3897			if ((req->flags & SYMLOOK_DLSYM) ||
3898			    (verndx >= VER_NDX_GIVEN) ||
3899			    (obj->versyms[symnum] & VER_NDX_HIDDEN))
3900				return (false);
3901		}
3902	}
3903	result->sym_out = symp;
3904	return (true);
3905}
3906
3907/*
3908 * Search for symbol using SysV hash function.
3909 * obj->buckets is known not to be NULL at this point; the test for this was
3910 * performed with the obj->valid_hash_sysv assignment.
3911 */
3912static int
3913symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj)
3914{
3915	unsigned long symnum;
3916	Sym_Match_Result matchres;
3917
3918	matchres.sym_out = NULL;
3919	matchres.vsymp = NULL;
3920	matchres.vcount = 0;
3921
3922	for (symnum = obj->buckets[req->hash % obj->nbuckets];
3923	    symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
3924		if (symnum >= obj->nchains)
3925			return (ESRCH);	/* Bad object */
3926
3927		if (matched_symbol(req, obj, &matchres, symnum)) {
3928			req->sym_out = matchres.sym_out;
3929			req->defobj_out = obj;
3930			return (0);
3931		}
3932	}
3933	if (matchres.vcount == 1) {
3934		req->sym_out = matchres.vsymp;
3935		req->defobj_out = obj;
3936		return (0);
3937	}
3938	return (ESRCH);
3939}
3940
3941/* Search for symbol using GNU hash function */
3942static int
3943symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj)
3944{
3945	Elf_Addr bloom_word;
3946	const Elf32_Word *hashval;
3947	Elf32_Word bucket;
3948	Sym_Match_Result matchres;
3949	unsigned int h1, h2;
3950	unsigned long symnum;
3951
3952	matchres.sym_out = NULL;
3953	matchres.vsymp = NULL;
3954	matchres.vcount = 0;
3955
3956	/* Pick right bitmask word from Bloom filter array */
3957	bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) &
3958	    obj->maskwords_bm_gnu];
3959
3960	/* Calculate modulus word size of gnu hash and its derivative */
3961	h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1);
3962	h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1));
3963
3964	/* Filter out the "definitely not in set" queries */
3965	if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0)
3966		return (ESRCH);
3967
3968	/* Locate hash chain and corresponding value element*/
3969	bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu];
3970	if (bucket == 0)
3971		return (ESRCH);
3972	hashval = &obj->chain_zero_gnu[bucket];
3973	do {
3974		if (((*hashval ^ req->hash_gnu) >> 1) == 0) {
3975			symnum = hashval - obj->chain_zero_gnu;
3976			if (matched_symbol(req, obj, &matchres, symnum)) {
3977				req->sym_out = matchres.sym_out;
3978				req->defobj_out = obj;
3979				return (0);
3980			}
3981		}
3982	} while ((*hashval++ & 1) == 0);
3983	if (matchres.vcount == 1) {
3984		req->sym_out = matchres.vsymp;
3985		req->defobj_out = obj;
3986		return (0);
3987	}
3988	return (ESRCH);
3989}
3990
3991static void
3992trace_loaded_objects(Obj_Entry *obj)
3993{
3994    char	*fmt1, *fmt2, *fmt, *main_local, *list_containers;
3995    int		c;
3996
3997    if ((main_local = getenv(LD_ "TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
3998	main_local = "";
3999
4000    if ((fmt1 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT1")) == NULL)
4001	fmt1 = "\t%o => %p (%x)\n";
4002
4003    if ((fmt2 = getenv(LD_ "TRACE_LOADED_OBJECTS_FMT2")) == NULL)
4004	fmt2 = "\t%o (%x)\n";
4005
4006    list_containers = getenv(LD_ "TRACE_LOADED_OBJECTS_ALL");
4007
4008    for (; obj; obj = obj->next) {
4009	Needed_Entry		*needed;
4010	char			*name, *path;
4011	bool			is_lib;
4012
4013	if (list_containers && obj->needed != NULL)
4014	    rtld_printf("%s:\n", obj->path);
4015	for (needed = obj->needed; needed; needed = needed->next) {
4016	    if (needed->obj != NULL) {
4017		if (needed->obj->traced && !list_containers)
4018		    continue;
4019		needed->obj->traced = true;
4020		path = needed->obj->path;
4021	    } else
4022		path = "not found";
4023
4024	    name = (char *)obj->strtab + needed->name;
4025	    is_lib = strncmp(name, "lib", 3) == 0;	/* XXX - bogus */
4026
4027	    fmt = is_lib ? fmt1 : fmt2;
4028	    while ((c = *fmt++) != '\0') {
4029		switch (c) {
4030		default:
4031		    rtld_putchar(c);
4032		    continue;
4033		case '\\':
4034		    switch (c = *fmt) {
4035		    case '\0':
4036			continue;
4037		    case 'n':
4038			rtld_putchar('\n');
4039			break;
4040		    case 't':
4041			rtld_putchar('\t');
4042			break;
4043		    }
4044		    break;
4045		case '%':
4046		    switch (c = *fmt) {
4047		    case '\0':
4048			continue;
4049		    case '%':
4050		    default:
4051			rtld_putchar(c);
4052			break;
4053		    case 'A':
4054			rtld_putstr(main_local);
4055			break;
4056		    case 'a':
4057			rtld_putstr(obj_main->path);
4058			break;
4059		    case 'o':
4060			rtld_putstr(name);
4061			break;
4062#if 0
4063		    case 'm':
4064			rtld_printf("%d", sodp->sod_major);
4065			break;
4066		    case 'n':
4067			rtld_printf("%d", sodp->sod_minor);
4068			break;
4069#endif
4070		    case 'p':
4071			rtld_putstr(path);
4072			break;
4073		    case 'x':
4074			rtld_printf("%p", needed->obj ? needed->obj->mapbase :
4075			  0);
4076			break;
4077		    }
4078		    break;
4079		}
4080		++fmt;
4081	    }
4082	}
4083    }
4084}
4085
4086/*
4087 * Unload a dlopened object and its dependencies from memory and from
4088 * our data structures.  It is assumed that the DAG rooted in the
4089 * object has already been unreferenced, and that the object has a
4090 * reference count of 0.
4091 */
4092static void
4093unload_object(Obj_Entry *root)
4094{
4095    Obj_Entry *obj;
4096    Obj_Entry **linkp;
4097
4098    assert(root->refcount == 0);
4099
4100    /*
4101     * Pass over the DAG removing unreferenced objects from
4102     * appropriate lists.
4103     */
4104    unlink_object(root);
4105
4106    /* Unmap all objects that are no longer referenced. */
4107    linkp = &obj_list->next;
4108    while ((obj = *linkp) != NULL) {
4109	if (obj->refcount == 0) {
4110	    LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
4111		obj->path);
4112	    dbg("unloading \"%s\"", obj->path);
4113	    unload_filtees(root);
4114	    munmap(obj->mapbase, obj->mapsize);
4115	    linkmap_delete(obj);
4116	    *linkp = obj->next;
4117	    obj_count--;
4118	    obj_free(obj);
4119	} else
4120	    linkp = &obj->next;
4121    }
4122    obj_tail = linkp;
4123}
4124
4125static void
4126unlink_object(Obj_Entry *root)
4127{
4128    Objlist_Entry *elm;
4129
4130    if (root->refcount == 0) {
4131	/* Remove the object from the RTLD_GLOBAL list. */
4132	objlist_remove(&list_global, root);
4133
4134    	/* Remove the object from all objects' DAG lists. */
4135    	STAILQ_FOREACH(elm, &root->dagmembers, link) {
4136	    objlist_remove(&elm->obj->dldags, root);
4137	    if (elm->obj != root)
4138		unlink_object(elm->obj);
4139	}
4140    }
4141}
4142
4143static void
4144ref_dag(Obj_Entry *root)
4145{
4146    Objlist_Entry *elm;
4147
4148    assert(root->dag_inited);
4149    STAILQ_FOREACH(elm, &root->dagmembers, link)
4150	elm->obj->refcount++;
4151}
4152
4153static void
4154unref_dag(Obj_Entry *root)
4155{
4156    Objlist_Entry *elm;
4157
4158    assert(root->dag_inited);
4159    STAILQ_FOREACH(elm, &root->dagmembers, link)
4160	elm->obj->refcount--;
4161}
4162
4163/*
4164 * Common code for MD __tls_get_addr().
4165 */
4166static void *tls_get_addr_slow(Elf_Addr **, int, size_t) __noinline;
4167static void *
4168tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset)
4169{
4170    Elf_Addr *newdtv, *dtv;
4171    RtldLockState lockstate;
4172    int to_copy;
4173
4174    dtv = *dtvp;
4175    /* Check dtv generation in case new modules have arrived */
4176    if (dtv[0] != tls_dtv_generation) {
4177	wlock_acquire(rtld_bind_lock, &lockstate);
4178	newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4179	to_copy = dtv[1];
4180	if (to_copy > tls_max_index)
4181	    to_copy = tls_max_index;
4182	memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
4183	newdtv[0] = tls_dtv_generation;
4184	newdtv[1] = tls_max_index;
4185	free(dtv);
4186	lock_release(rtld_bind_lock, &lockstate);
4187	dtv = *dtvp = newdtv;
4188    }
4189
4190    /* Dynamically allocate module TLS if necessary */
4191    if (dtv[index + 1] == 0) {
4192	/* Signal safe, wlock will block out signals. */
4193	wlock_acquire(rtld_bind_lock, &lockstate);
4194	if (!dtv[index + 1])
4195	    dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
4196	lock_release(rtld_bind_lock, &lockstate);
4197    }
4198    return ((void *)(dtv[index + 1] + offset));
4199}
4200
4201void *
4202tls_get_addr_common(Elf_Addr **dtvp, int index, size_t offset)
4203{
4204	Elf_Addr *dtv;
4205
4206	dtv = *dtvp;
4207	/* Check dtv generation in case new modules have arrived */
4208	if (__predict_true(dtv[0] == tls_dtv_generation &&
4209	    dtv[index + 1] != 0))
4210		return ((void *)(dtv[index + 1] + offset));
4211	return (tls_get_addr_slow(dtvp, index, offset));
4212}
4213
4214#if defined(__arm__) || defined(__ia64__) || defined(__mips__) || defined(__powerpc__)
4215
4216/*
4217 * Allocate Static TLS using the Variant I method.
4218 */
4219void *
4220allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
4221{
4222    Obj_Entry *obj;
4223    char *tcb;
4224    Elf_Addr **tls;
4225    Elf_Addr *dtv;
4226    Elf_Addr addr;
4227    int i;
4228
4229    if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
4230	return (oldtcb);
4231
4232    assert(tcbsize >= TLS_TCB_SIZE);
4233    tcb = xcalloc(1, tls_static_space - TLS_TCB_SIZE + tcbsize);
4234    tls = (Elf_Addr **)(tcb + tcbsize - TLS_TCB_SIZE);
4235
4236    if (oldtcb != NULL) {
4237	memcpy(tls, oldtcb, tls_static_space);
4238	free(oldtcb);
4239
4240	/* Adjust the DTV. */
4241	dtv = tls[0];
4242	for (i = 0; i < dtv[1]; i++) {
4243	    if (dtv[i+2] >= (Elf_Addr)oldtcb &&
4244		dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
4245		dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tls;
4246	    }
4247	}
4248    } else {
4249	dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4250	tls[0] = dtv;
4251	dtv[0] = tls_dtv_generation;
4252	dtv[1] = tls_max_index;
4253
4254	for (obj = objs; obj; obj = obj->next) {
4255	    if (obj->tlsoffset > 0) {
4256		addr = (Elf_Addr)tls + obj->tlsoffset;
4257		if (obj->tlsinitsize > 0)
4258		    memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
4259		if (obj->tlssize > obj->tlsinitsize)
4260		    memset((void*) (addr + obj->tlsinitsize), 0,
4261			   obj->tlssize - obj->tlsinitsize);
4262		dtv[obj->tlsindex + 1] = addr;
4263	    }
4264	}
4265    }
4266
4267    return (tcb);
4268}
4269
4270void
4271free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
4272{
4273    Elf_Addr *dtv;
4274    Elf_Addr tlsstart, tlsend;
4275    int dtvsize, i;
4276
4277    assert(tcbsize >= TLS_TCB_SIZE);
4278
4279    tlsstart = (Elf_Addr)tcb + tcbsize - TLS_TCB_SIZE;
4280    tlsend = tlsstart + tls_static_space;
4281
4282    dtv = *(Elf_Addr **)tlsstart;
4283    dtvsize = dtv[1];
4284    for (i = 0; i < dtvsize; i++) {
4285	if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
4286	    free((void*)dtv[i+2]);
4287	}
4288    }
4289    free(dtv);
4290    free(tcb);
4291}
4292
4293#endif
4294
4295#if defined(__i386__) || defined(__amd64__) || defined(__sparc64__)
4296
4297/*
4298 * Allocate Static TLS using the Variant II method.
4299 */
4300void *
4301allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
4302{
4303    Obj_Entry *obj;
4304    size_t size, ralign;
4305    char *tls;
4306    Elf_Addr *dtv, *olddtv;
4307    Elf_Addr segbase, oldsegbase, addr;
4308    int i;
4309
4310    ralign = tcbalign;
4311    if (tls_static_max_align > ralign)
4312	    ralign = tls_static_max_align;
4313    size = round(tls_static_space, ralign) + round(tcbsize, ralign);
4314
4315    assert(tcbsize >= 2*sizeof(Elf_Addr));
4316    tls = malloc_aligned(size, ralign);
4317    dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
4318
4319    segbase = (Elf_Addr)(tls + round(tls_static_space, ralign));
4320    ((Elf_Addr*)segbase)[0] = segbase;
4321    ((Elf_Addr*)segbase)[1] = (Elf_Addr) dtv;
4322
4323    dtv[0] = tls_dtv_generation;
4324    dtv[1] = tls_max_index;
4325
4326    if (oldtls) {
4327	/*
4328	 * Copy the static TLS block over whole.
4329	 */
4330	oldsegbase = (Elf_Addr) oldtls;
4331	memcpy((void *)(segbase - tls_static_space),
4332	       (const void *)(oldsegbase - tls_static_space),
4333	       tls_static_space);
4334
4335	/*
4336	 * If any dynamic TLS blocks have been created tls_get_addr(),
4337	 * move them over.
4338	 */
4339	olddtv = ((Elf_Addr**)oldsegbase)[1];
4340	for (i = 0; i < olddtv[1]; i++) {
4341	    if (olddtv[i+2] < oldsegbase - size || olddtv[i+2] > oldsegbase) {
4342		dtv[i+2] = olddtv[i+2];
4343		olddtv[i+2] = 0;
4344	    }
4345	}
4346
4347	/*
4348	 * We assume that this block was the one we created with
4349	 * allocate_initial_tls().
4350	 */
4351	free_tls(oldtls, 2*sizeof(Elf_Addr), sizeof(Elf_Addr));
4352    } else {
4353	for (obj = objs; obj; obj = obj->next) {
4354	    if (obj->tlsoffset) {
4355		addr = segbase - obj->tlsoffset;
4356		memset((void*) (addr + obj->tlsinitsize),
4357		       0, obj->tlssize - obj->tlsinitsize);
4358		if (obj->tlsinit)
4359		    memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
4360		dtv[obj->tlsindex + 1] = addr;
4361	    }
4362	}
4363    }
4364
4365    return (void*) segbase;
4366}
4367
4368void
4369free_tls(void *tls, size_t tcbsize, size_t tcbalign)
4370{
4371    Elf_Addr* dtv;
4372    size_t size, ralign;
4373    int dtvsize, i;
4374    Elf_Addr tlsstart, tlsend;
4375
4376    /*
4377     * Figure out the size of the initial TLS block so that we can
4378     * find stuff which ___tls_get_addr() allocated dynamically.
4379     */
4380    ralign = tcbalign;
4381    if (tls_static_max_align > ralign)
4382	    ralign = tls_static_max_align;
4383    size = round(tls_static_space, ralign);
4384
4385    dtv = ((Elf_Addr**)tls)[1];
4386    dtvsize = dtv[1];
4387    tlsend = (Elf_Addr) tls;
4388    tlsstart = tlsend - size;
4389    for (i = 0; i < dtvsize; i++) {
4390	if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart || dtv[i + 2] > tlsend)) {
4391		free_aligned((void *)dtv[i + 2]);
4392	}
4393    }
4394
4395    free_aligned((void *)tlsstart);
4396    free((void*) dtv);
4397}
4398
4399#endif
4400
4401/*
4402 * Allocate TLS block for module with given index.
4403 */
4404void *
4405allocate_module_tls(int index)
4406{
4407    Obj_Entry* obj;
4408    char* p;
4409
4410    for (obj = obj_list; obj; obj = obj->next) {
4411	if (obj->tlsindex == index)
4412	    break;
4413    }
4414    if (!obj) {
4415	_rtld_error("Can't find module with TLS index %d", index);
4416	die();
4417    }
4418
4419    p = malloc_aligned(obj->tlssize, obj->tlsalign);
4420    memcpy(p, obj->tlsinit, obj->tlsinitsize);
4421    memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
4422
4423    return p;
4424}
4425
4426bool
4427allocate_tls_offset(Obj_Entry *obj)
4428{
4429    size_t off;
4430
4431    if (obj->tls_done)
4432	return true;
4433
4434    if (obj->tlssize == 0) {
4435	obj->tls_done = true;
4436	return true;
4437    }
4438
4439    if (obj->tlsindex == 1)
4440	off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
4441    else
4442	off = calculate_tls_offset(tls_last_offset, tls_last_size,
4443				   obj->tlssize, obj->tlsalign);
4444
4445    /*
4446     * If we have already fixed the size of the static TLS block, we
4447     * must stay within that size. When allocating the static TLS, we
4448     * leave a small amount of space spare to be used for dynamically
4449     * loading modules which use static TLS.
4450     */
4451    if (tls_static_space != 0) {
4452	if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
4453	    return false;
4454    } else if (obj->tlsalign > tls_static_max_align) {
4455	    tls_static_max_align = obj->tlsalign;
4456    }
4457
4458    tls_last_offset = obj->tlsoffset = off;
4459    tls_last_size = obj->tlssize;
4460    obj->tls_done = true;
4461
4462    return true;
4463}
4464
4465void
4466free_tls_offset(Obj_Entry *obj)
4467{
4468
4469    /*
4470     * If we were the last thing to allocate out of the static TLS
4471     * block, we give our space back to the 'allocator'. This is a
4472     * simplistic workaround to allow libGL.so.1 to be loaded and
4473     * unloaded multiple times.
4474     */
4475    if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
4476	== calculate_tls_end(tls_last_offset, tls_last_size)) {
4477	tls_last_offset -= obj->tlssize;
4478	tls_last_size = 0;
4479    }
4480}
4481
4482void *
4483_rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
4484{
4485    void *ret;
4486    RtldLockState lockstate;
4487
4488    wlock_acquire(rtld_bind_lock, &lockstate);
4489    ret = allocate_tls(obj_list, oldtls, tcbsize, tcbalign);
4490    lock_release(rtld_bind_lock, &lockstate);
4491    return (ret);
4492}
4493
4494void
4495_rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
4496{
4497    RtldLockState lockstate;
4498
4499    wlock_acquire(rtld_bind_lock, &lockstate);
4500    free_tls(tcb, tcbsize, tcbalign);
4501    lock_release(rtld_bind_lock, &lockstate);
4502}
4503
4504static void
4505object_add_name(Obj_Entry *obj, const char *name)
4506{
4507    Name_Entry *entry;
4508    size_t len;
4509
4510    len = strlen(name);
4511    entry = malloc(sizeof(Name_Entry) + len);
4512
4513    if (entry != NULL) {
4514	strcpy(entry->name, name);
4515	STAILQ_INSERT_TAIL(&obj->names, entry, link);
4516    }
4517}
4518
4519static int
4520object_match_name(const Obj_Entry *obj, const char *name)
4521{
4522    Name_Entry *entry;
4523
4524    STAILQ_FOREACH(entry, &obj->names, link) {
4525	if (strcmp(name, entry->name) == 0)
4526	    return (1);
4527    }
4528    return (0);
4529}
4530
4531static Obj_Entry *
4532locate_dependency(const Obj_Entry *obj, const char *name)
4533{
4534    const Objlist_Entry *entry;
4535    const Needed_Entry *needed;
4536
4537    STAILQ_FOREACH(entry, &list_main, link) {
4538	if (object_match_name(entry->obj, name))
4539	    return entry->obj;
4540    }
4541
4542    for (needed = obj->needed;  needed != NULL;  needed = needed->next) {
4543	if (strcmp(obj->strtab + needed->name, name) == 0 ||
4544	  (needed->obj != NULL && object_match_name(needed->obj, name))) {
4545	    /*
4546	     * If there is DT_NEEDED for the name we are looking for,
4547	     * we are all set.  Note that object might not be found if
4548	     * dependency was not loaded yet, so the function can
4549	     * return NULL here.  This is expected and handled
4550	     * properly by the caller.
4551	     */
4552	    return (needed->obj);
4553	}
4554    }
4555    _rtld_error("%s: Unexpected inconsistency: dependency %s not found",
4556	obj->path, name);
4557    die();
4558}
4559
4560static int
4561check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
4562    const Elf_Vernaux *vna)
4563{
4564    const Elf_Verdef *vd;
4565    const char *vername;
4566
4567    vername = refobj->strtab + vna->vna_name;
4568    vd = depobj->verdef;
4569    if (vd == NULL) {
4570	_rtld_error("%s: version %s required by %s not defined",
4571	    depobj->path, vername, refobj->path);
4572	return (-1);
4573    }
4574    for (;;) {
4575	if (vd->vd_version != VER_DEF_CURRENT) {
4576	    _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
4577		depobj->path, vd->vd_version);
4578	    return (-1);
4579	}
4580	if (vna->vna_hash == vd->vd_hash) {
4581	    const Elf_Verdaux *aux = (const Elf_Verdaux *)
4582		((char *)vd + vd->vd_aux);
4583	    if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
4584		return (0);
4585	}
4586	if (vd->vd_next == 0)
4587	    break;
4588	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4589    }
4590    if (vna->vna_flags & VER_FLG_WEAK)
4591	return (0);
4592    _rtld_error("%s: version %s required by %s not found",
4593	depobj->path, vername, refobj->path);
4594    return (-1);
4595}
4596
4597static int
4598rtld_verify_object_versions(Obj_Entry *obj)
4599{
4600    const Elf_Verneed *vn;
4601    const Elf_Verdef  *vd;
4602    const Elf_Verdaux *vda;
4603    const Elf_Vernaux *vna;
4604    const Obj_Entry *depobj;
4605    int maxvernum, vernum;
4606
4607    if (obj->ver_checked)
4608	return (0);
4609    obj->ver_checked = true;
4610
4611    maxvernum = 0;
4612    /*
4613     * Walk over defined and required version records and figure out
4614     * max index used by any of them. Do very basic sanity checking
4615     * while there.
4616     */
4617    vn = obj->verneed;
4618    while (vn != NULL) {
4619	if (vn->vn_version != VER_NEED_CURRENT) {
4620	    _rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
4621		obj->path, vn->vn_version);
4622	    return (-1);
4623	}
4624	vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
4625	for (;;) {
4626	    vernum = VER_NEED_IDX(vna->vna_other);
4627	    if (vernum > maxvernum)
4628		maxvernum = vernum;
4629	    if (vna->vna_next == 0)
4630		 break;
4631	    vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
4632	}
4633	if (vn->vn_next == 0)
4634	    break;
4635	vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
4636    }
4637
4638    vd = obj->verdef;
4639    while (vd != NULL) {
4640	if (vd->vd_version != VER_DEF_CURRENT) {
4641	    _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
4642		obj->path, vd->vd_version);
4643	    return (-1);
4644	}
4645	vernum = VER_DEF_IDX(vd->vd_ndx);
4646	if (vernum > maxvernum)
4647		maxvernum = vernum;
4648	if (vd->vd_next == 0)
4649	    break;
4650	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4651    }
4652
4653    if (maxvernum == 0)
4654	return (0);
4655
4656    /*
4657     * Store version information in array indexable by version index.
4658     * Verify that object version requirements are satisfied along the
4659     * way.
4660     */
4661    obj->vernum = maxvernum + 1;
4662    obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry));
4663
4664    vd = obj->verdef;
4665    while (vd != NULL) {
4666	if ((vd->vd_flags & VER_FLG_BASE) == 0) {
4667	    vernum = VER_DEF_IDX(vd->vd_ndx);
4668	    assert(vernum <= maxvernum);
4669	    vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux);
4670	    obj->vertab[vernum].hash = vd->vd_hash;
4671	    obj->vertab[vernum].name = obj->strtab + vda->vda_name;
4672	    obj->vertab[vernum].file = NULL;
4673	    obj->vertab[vernum].flags = 0;
4674	}
4675	if (vd->vd_next == 0)
4676	    break;
4677	vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
4678    }
4679
4680    vn = obj->verneed;
4681    while (vn != NULL) {
4682	depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
4683	if (depobj == NULL)
4684	    return (-1);
4685	vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
4686	for (;;) {
4687	    if (check_object_provided_version(obj, depobj, vna))
4688		return (-1);
4689	    vernum = VER_NEED_IDX(vna->vna_other);
4690	    assert(vernum <= maxvernum);
4691	    obj->vertab[vernum].hash = vna->vna_hash;
4692	    obj->vertab[vernum].name = obj->strtab + vna->vna_name;
4693	    obj->vertab[vernum].file = obj->strtab + vn->vn_file;
4694	    obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ?
4695		VER_INFO_HIDDEN : 0;
4696	    if (vna->vna_next == 0)
4697		 break;
4698	    vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
4699	}
4700	if (vn->vn_next == 0)
4701	    break;
4702	vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
4703    }
4704    return 0;
4705}
4706
4707static int
4708rtld_verify_versions(const Objlist *objlist)
4709{
4710    Objlist_Entry *entry;
4711    int rc;
4712
4713    rc = 0;
4714    STAILQ_FOREACH(entry, objlist, link) {
4715	/*
4716	 * Skip dummy objects or objects that have their version requirements
4717	 * already checked.
4718	 */
4719	if (entry->obj->strtab == NULL || entry->obj->vertab != NULL)
4720	    continue;
4721	if (rtld_verify_object_versions(entry->obj) == -1) {
4722	    rc = -1;
4723	    if (ld_tracing == NULL)
4724		break;
4725	}
4726    }
4727    if (rc == 0 || ld_tracing != NULL)
4728    	rc = rtld_verify_object_versions(&obj_rtld);
4729    return rc;
4730}
4731
4732const Ver_Entry *
4733fetch_ventry(const Obj_Entry *obj, unsigned long symnum)
4734{
4735    Elf_Versym vernum;
4736
4737    if (obj->vertab) {
4738	vernum = VER_NDX(obj->versyms[symnum]);
4739	if (vernum >= obj->vernum) {
4740	    _rtld_error("%s: symbol %s has wrong verneed value %d",
4741		obj->path, obj->strtab + symnum, vernum);
4742	} else if (obj->vertab[vernum].hash != 0) {
4743	    return &obj->vertab[vernum];
4744	}
4745    }
4746    return NULL;
4747}
4748
4749int
4750_rtld_get_stack_prot(void)
4751{
4752
4753	return (stack_prot);
4754}
4755
4756int
4757_rtld_is_dlopened(void *arg)
4758{
4759	Obj_Entry *obj;
4760	RtldLockState lockstate;
4761	int res;
4762
4763	rlock_acquire(rtld_bind_lock, &lockstate);
4764	obj = dlcheck(arg);
4765	if (obj == NULL)
4766		obj = obj_from_addr(arg);
4767	if (obj == NULL) {
4768		_rtld_error("No shared object contains address");
4769		lock_release(rtld_bind_lock, &lockstate);
4770		return (-1);
4771	}
4772	res = obj->dlopened ? 1 : 0;
4773	lock_release(rtld_bind_lock, &lockstate);
4774	return (res);
4775}
4776
4777static void
4778map_stacks_exec(RtldLockState *lockstate)
4779{
4780	void (*thr_map_stacks_exec)(void);
4781
4782	if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0)
4783		return;
4784	thr_map_stacks_exec = (void (*)(void))(uintptr_t)
4785	    get_program_var_addr("__pthread_map_stacks_exec", lockstate);
4786	if (thr_map_stacks_exec != NULL) {
4787		stack_prot |= PROT_EXEC;
4788		thr_map_stacks_exec();
4789	}
4790}
4791
4792void
4793symlook_init(SymLook *dst, const char *name)
4794{
4795
4796	bzero(dst, sizeof(*dst));
4797	dst->name = name;
4798	dst->hash = elf_hash(name);
4799	dst->hash_gnu = gnu_hash(name);
4800}
4801
4802static void
4803symlook_init_from_req(SymLook *dst, const SymLook *src)
4804{
4805
4806	dst->name = src->name;
4807	dst->hash = src->hash;
4808	dst->hash_gnu = src->hash_gnu;
4809	dst->ventry = src->ventry;
4810	dst->flags = src->flags;
4811	dst->defobj_out = NULL;
4812	dst->sym_out = NULL;
4813	dst->lockstate = src->lockstate;
4814}
4815
4816/*
4817 * Overrides for libc_pic-provided functions.
4818 */
4819
4820int
4821__getosreldate(void)
4822{
4823	size_t len;
4824	int oid[2];
4825	int error, osrel;
4826
4827	if (osreldate != 0)
4828		return (osreldate);
4829
4830	oid[0] = CTL_KERN;
4831	oid[1] = KERN_OSRELDATE;
4832	osrel = 0;
4833	len = sizeof(osrel);
4834	error = sysctl(oid, 2, &osrel, &len, NULL, 0);
4835	if (error == 0 && osrel > 0 && len == sizeof(osrel))
4836		osreldate = osrel;
4837	return (osreldate);
4838}
4839
4840void
4841exit(int status)
4842{
4843
4844	_exit(status);
4845}
4846
4847void (*__cleanup)(void);
4848int __isthreaded = 0;
4849int _thread_autoinit_dummy_decl = 1;
4850
4851/*
4852 * No unresolved symbols for rtld.
4853 */
4854void
4855__pthread_cxa_finalize(struct dl_phdr_info *a)
4856{
4857}
4858
4859void
4860__stack_chk_fail(void)
4861{
4862
4863	_rtld_error("stack overflow detected; terminated");
4864	die();
4865}
4866__weak_reference(__stack_chk_fail, __stack_chk_fail_local);
4867
4868void
4869__chk_fail(void)
4870{
4871
4872	_rtld_error("buffer overflow detected; terminated");
4873	die();
4874}
4875
4876const char *
4877rtld_strerror(int errnum)
4878{
4879
4880	if (errnum < 0 || errnum >= sys_nerr)
4881		return ("Unknown error");
4882	return (sys_errlist[errnum]);
4883}
4884