rtld: Clang fixes
[dragonfly.git] / libexec / rtld-elf / rtld.c
CommitLineData
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1/*-
2 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
3 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>.
fcf53d9b 4 * Copyright 2009, 2010, 2011 Konstantin Belousov <kib@FreeBSD.ORG>.
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5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
fcf53d9b 27 * $FreeBSD: src/libexec/rtld-elf/rtld.c,v 1.173 2011/02/09 09:20:27 kib Exp $
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28 */
29
30/*
31 * Dynamic linker for ELF.
32 *
33 * John Polstra <jdp@polstra.com>.
34 */
35
36#ifndef __GNUC__
37#error "GCC is needed to compile this file"
38#endif
39
40#include <sys/param.h>
fcf53d9b 41#include <sys/mount.h>
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42#include <sys/mman.h>
43#include <sys/stat.h>
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44#include <sys/uio.h>
45#include <sys/utsname.h>
46#include <sys/ktrace.h>
8ca15ec8 47#include <sys/resident.h>
bc633d63 48#include <sys/tls.h>
984263bc 49
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50#include <machine/tls.h>
51
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52#include <dlfcn.h>
53#include <err.h>
54#include <errno.h>
55#include <fcntl.h>
56#include <stdarg.h>
57#include <stdio.h>
58#include <stdlib.h>
59#include <string.h>
60#include <unistd.h>
61
62#include "debug.h"
63#include "rtld.h"
fcf53d9b 64#include "libmap.h"
984263bc 65
a1eee96a 66#define PATH_RTLD "/usr/libexec/ld-elf.so.2"
8ca15ec8 67#define LD_ARY_CACHE 16
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68
69/* Types. */
70typedef void (*func_ptr_type)();
71typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
72
73/*
74 * This structure provides a reentrant way to keep a list of objects and
75 * check which ones have already been processed in some way.
76 */
77typedef struct Struct_DoneList {
78 const Obj_Entry **objs; /* Array of object pointers */
79 unsigned int num_alloc; /* Allocated size of the array */
80 unsigned int num_used; /* Number of array slots used */
81} DoneList;
82
83/*
84 * Function declarations.
85 */
8ca15ec8 86static const char *_getenv_ld(const char *id);
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87static void die(void) __dead2;
88static void digest_dynamic(Obj_Entry *, int);
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89static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
90static Obj_Entry *dlcheck(void *);
fcf53d9b 91static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
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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(void);
99static void init_dag(Obj_Entry *);
fcf53d9b 100static void init_dag1(Obj_Entry *, Obj_Entry *, DoneList *);
984263bc 101static void init_rtld(caddr_t);
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102static void initlist_add_neededs(Needed_Entry *, Objlist *);
103static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
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104static bool is_exported(const Elf_Sym *);
105static void linkmap_add(Obj_Entry *);
106static void linkmap_delete(Obj_Entry *);
fcf53d9b 107static int load_needed_objects(Obj_Entry *, int);
984263bc 108static int load_preload_objects(void);
fcf53d9b 109static Obj_Entry *load_object(const char *, const Obj_Entry *, int);
984263bc 110static Obj_Entry *obj_from_addr(const void *);
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111static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
112static void objlist_call_init(Objlist *, RtldLockState *);
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113static void objlist_clear(Objlist *);
114static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
115static void objlist_init(Objlist *);
116static void objlist_push_head(Objlist *, Obj_Entry *);
117static void objlist_push_tail(Objlist *, Obj_Entry *);
118static void objlist_remove(Objlist *, Obj_Entry *);
984263bc 119static void *path_enumerate(const char *, path_enum_proc, void *);
c3098c28 120static int relocate_objects(Obj_Entry *, bool, Obj_Entry *);
984263bc 121static int rtld_dirname(const char *, char *);
fcf53d9b 122static int rtld_dirname_abs(const char *, char *);
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123static void rtld_exit(void);
124static char *search_library_path(const char *, const char *);
fcf53d9b 125static const void **get_program_var_addr(const char *);
984263bc 126static void set_program_var(const char *, const void *);
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127static const Elf_Sym *symlook_default(const char *, unsigned long,
128 const Obj_Entry *, const Obj_Entry **, const Ver_Entry *, int);
129static const Elf_Sym *symlook_list(const char *, unsigned long, const Objlist *,
130 const Obj_Entry **, const Ver_Entry *, int, DoneList *);
cebaf0af 131static const Elf_Sym *symlook_needed(const char *, unsigned long,
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132 const Needed_Entry *, const Obj_Entry **, const Ver_Entry *,
133 int, DoneList *);
134static void trace_loaded_objects(Obj_Entry *);
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135static void unlink_object(Obj_Entry *);
136static void unload_object(Obj_Entry *);
137static void unref_dag(Obj_Entry *);
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138static void ref_dag(Obj_Entry *);
139static int origin_subst_one(char **, const char *, const char *,
140 const char *, char *);
141static char *origin_subst(const char *, const char *);
142static int rtld_verify_versions(const Objlist *);
143static int rtld_verify_object_versions(Obj_Entry *);
144static void object_add_name(Obj_Entry *, const char *);
145static int object_match_name(const Obj_Entry *, const char *);
146static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
147static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
148 struct dl_phdr_info *phdr_info);
149
8301820e 150void r_debug_state(struct r_debug *, struct link_map *) __noinline;
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151
152/*
153 * Data declarations.
154 */
155static char *error_message; /* Message for dlerror(), or NULL */
156struct r_debug r_debug; /* for GDB; */
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157static bool libmap_disable; /* Disable libmap */
158static char *libmap_override; /* Maps to use in addition to libmap.conf */
984263bc 159static bool trust; /* False for setuid and setgid programs */
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160static bool dangerous_ld_env; /* True if environment variables have been
161 used to affect the libraries loaded */
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162static const char *ld_bind_now; /* Environment variable for immediate binding */
163static const char *ld_debug; /* Environment variable for debugging */
164static const char *ld_library_path; /* Environment variable for search path */
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165static char *ld_preload; /* Environment variable for libraries to
166 load first */
fcf53d9b 167static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */
8ca15ec8 168static const char *ld_tracing; /* Called from ldd(1) to print libs */
38e4b3b6 169 /* Optional function call tracing hook */
fcf53d9b 170static const char *ld_utrace; /* Use utrace() to log events. */
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171static int (*rtld_functrace)(const char *caller_obj,
172 const char *callee_obj,
173 const char *callee_func,
174 void *stack);
175static Obj_Entry *rtld_functrace_obj; /* Object thereof */
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176static Obj_Entry *obj_list; /* Head of linked list of shared objects */
177static Obj_Entry **obj_tail; /* Link field of last object in list */
8ca15ec8 178static Obj_Entry **preload_tail;
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179static Obj_Entry *obj_main; /* The main program shared object */
180static Obj_Entry obj_rtld; /* The dynamic linker shared object */
181static unsigned int obj_count; /* Number of objects in obj_list */
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182static unsigned int obj_loads; /* Number of objects in obj_list */
183
33a8b578 184static int ld_resident; /* Non-zero if resident */
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185static const char *ld_ary[LD_ARY_CACHE];
186static int ld_index;
a1eee96a 187static Objlist initlist;
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188
189static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
190 STAILQ_HEAD_INITIALIZER(list_global);
191static Objlist list_main = /* Objects loaded at program startup */
192 STAILQ_HEAD_INITIALIZER(list_main);
193static Objlist list_fini = /* Objects needing fini() calls */
194 STAILQ_HEAD_INITIALIZER(list_fini);
195
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196static Elf_Sym sym_zero; /* For resolving undefined weak refs. */
197
198#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
199
200extern Elf_Dyn _DYNAMIC;
201#pragma weak _DYNAMIC
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202#ifndef RTLD_IS_DYNAMIC
203#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL)
204#endif
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205
206/*
207 * These are the functions the dynamic linker exports to application
208 * programs. They are the only symbols the dynamic linker is willing
209 * to export from itself.
210 */
211static func_ptr_type exports[] = {
212 (func_ptr_type) &_rtld_error,
213 (func_ptr_type) &dlclose,
214 (func_ptr_type) &dlerror,
215 (func_ptr_type) &dlopen,
fcf53d9b 216 (func_ptr_type) &dlfunc,
984263bc 217 (func_ptr_type) &dlsym,
fcf53d9b 218 (func_ptr_type) &dlvsym,
984263bc 219 (func_ptr_type) &dladdr,
984263bc 220 (func_ptr_type) &dlinfo,
fcf53d9b 221 (func_ptr_type) &dl_iterate_phdr,
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222#ifdef __i386__
223 (func_ptr_type) &___tls_get_addr,
224#endif
225 (func_ptr_type) &__tls_get_addr,
a1eee96a 226 (func_ptr_type) &__tls_get_addr_tcb,
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227 (func_ptr_type) &_rtld_allocate_tls,
228 (func_ptr_type) &_rtld_free_tls,
a1eee96a 229 (func_ptr_type) &_rtld_call_init,
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230 (func_ptr_type) &_rtld_thread_init,
231 (func_ptr_type) &_rtld_addr_phdr,
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232 NULL
233};
234
235/*
236 * Global declarations normally provided by crt1. The dynamic linker is
237 * not built with crt1, so we have to provide them ourselves.
238 */
239char *__progname;
240char **environ;
241
242/*
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243 * Globals to control TLS allocation.
244 */
245size_t tls_last_offset; /* Static TLS offset of last module */
246size_t tls_last_size; /* Static TLS size of last module */
247size_t tls_static_space; /* Static TLS space allocated */
248int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
249int tls_max_index = 1; /* Largest module index allocated */
250
251/*
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252 * Fill in a DoneList with an allocation large enough to hold all of
253 * the currently-loaded objects. Keep this as a macro since it calls
254 * alloca and we want that to occur within the scope of the caller.
255 */
256#define donelist_init(dlp) \
257 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
258 assert((dlp)->objs != NULL), \
259 (dlp)->num_alloc = obj_count, \
260 (dlp)->num_used = 0)
261
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262#define UTRACE_DLOPEN_START 1
263#define UTRACE_DLOPEN_STOP 2
264#define UTRACE_DLCLOSE_START 3
265#define UTRACE_DLCLOSE_STOP 4
266#define UTRACE_LOAD_OBJECT 5
267#define UTRACE_UNLOAD_OBJECT 6
268#define UTRACE_ADD_RUNDEP 7
269#define UTRACE_PRELOAD_FINISHED 8
270#define UTRACE_INIT_CALL 9
271#define UTRACE_FINI_CALL 10
272
273struct utrace_rtld {
274 char sig[4]; /* 'RTLD' */
275 int event;
276 void *handle;
277 void *mapbase; /* Used for 'parent' and 'init/fini' */
278 size_t mapsize;
279 int refcnt; /* Used for 'mode' */
280 char name[MAXPATHLEN];
281};
984263bc 282
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283#define LD_UTRACE(e, h, mb, ms, r, n) do { \
284 if (ld_utrace != NULL) \
285 ld_utrace_log(e, h, mb, ms, r, n); \
286} while (0)
984263bc 287
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288static void
289ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
290 int refcnt, const char *name)
291{
292 struct utrace_rtld ut;
293
294 ut.sig[0] = 'R';
295 ut.sig[1] = 'T';
296 ut.sig[2] = 'L';
297 ut.sig[3] = 'D';
298 ut.event = event;
299 ut.handle = handle;
300 ut.mapbase = mapbase;
301 ut.mapsize = mapsize;
302 ut.refcnt = refcnt;
303 bzero(ut.name, sizeof(ut.name));
304 if (name)
305 strlcpy(ut.name, name, sizeof(ut.name));
306 utrace(&ut, sizeof(ut));
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307}
308
309/*
310 * Main entry point for dynamic linking. The first argument is the
311 * stack pointer. The stack is expected to be laid out as described
312 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
313 * Specifically, the stack pointer points to a word containing
314 * ARGC. Following that in the stack is a null-terminated sequence
315 * of pointers to argument strings. Then comes a null-terminated
316 * sequence of pointers to environment strings. Finally, there is a
317 * sequence of "auxiliary vector" entries.
318 *
319 * The second argument points to a place to store the dynamic linker's
320 * exit procedure pointer and the third to a place to store the main
321 * program's object.
322 *
323 * The return value is the main program's entry point.
324 */
325func_ptr_type
326_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
327{
328 Elf_Auxinfo *aux_info[AT_COUNT];
329 int i;
330 int argc;
331 char **argv;
332 char **env;
333 Elf_Auxinfo *aux;
334 Elf_Auxinfo *auxp;
335 const char *argv0;
55b88cae 336 Objlist_Entry *entry;
984263bc 337 Obj_Entry *obj;
984263bc 338
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339 /* marino: DO NOT MOVE THESE VARIABLES TO _rtld
340 Obj_Entry **preload_tail;
341 Objlist initlist;
342 from global to here. It will break the DRAWF2 unwind scheme.
343 The system compilers were unaffected, but not gcc 4.6
344 */
345
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346 /*
347 * On entry, the dynamic linker itself has not been relocated yet.
348 * Be very careful not to reference any global data until after
349 * init_rtld has returned. It is OK to reference file-scope statics
350 * and string constants, and to call static and global functions.
351 */
352
353 /* Find the auxiliary vector on the stack. */
354 argc = *sp++;
355 argv = (char **) sp;
356 sp += argc + 1; /* Skip over arguments and NULL terminator */
357 env = (char **) sp;
984263bc 358
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359 /*
360 * If we aren't already resident we have to dig out some more info.
361 * Note that auxinfo does not exist when we are resident.
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362 *
363 * I'm not sure about the ld_resident check. It seems to read zero
364 * prior to relocation, which is what we want. When running from a
365 * resident copy everything will be relocated so we are definitely
366 * good there.
33a8b578 367 */
5347affc 368 if (ld_resident == 0) {
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MD
369 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
370 ;
371 aux = (Elf_Auxinfo *) sp;
372
373 /* Digest the auxiliary vector. */
374 for (i = 0; i < AT_COUNT; i++)
375 aux_info[i] = NULL;
376 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
377 if (auxp->a_type < AT_COUNT)
378 aux_info[auxp->a_type] = auxp;
379 }
380
381 /* Initialize and relocate ourselves. */
382 assert(aux_info[AT_BASE] != NULL);
383 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
384 }
984263bc 385
5347affc 386 ld_index = 0; /* don't use old env cache in case we are resident */
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MD
387 __progname = obj_rtld.path;
388 argv0 = argv[0] != NULL ? argv[0] : "(null)";
389 environ = env;
390
fcf53d9b 391 trust = !issetugid();
984263bc 392
8ca15ec8 393 ld_bind_now = _getenv_ld("LD_BIND_NOW");
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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_DEBUG")
402 || unsetenv("LD_PRELOAD")
403 || unsetenv("LD_LIBRARY_PATH")
404 || unsetenv("LD_ELF_HINTS_PATH")
405 || unsetenv("LD_LIBMAP")
406 || unsetenv("LD_LIBMAP_DISABLE")
407 ) {
408 _rtld_error("environment corrupt; aborting");
409 die();
410 }
984263bc 411 }
fcf53d9b
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412 ld_debug = _getenv_ld("LD_DEBUG");
413 ld_library_path = _getenv_ld("LD_LIBRARY_PATH");
414 ld_preload = (char *)_getenv_ld("LD_PRELOAD");
415 ld_elf_hints_path = _getenv_ld("LD_ELF_HINTS_PATH");
416 libmap_override = (char *)_getenv_ld("LD_LIBMAP");
417 libmap_disable = _getenv_ld("LD_LIBMAP_DISABLE") != NULL;
418 dangerous_ld_env = (ld_library_path != NULL)
419 || (ld_preload != NULL)
420 || (ld_elf_hints_path != NULL)
421 || (libmap_override != NULL)
422 || libmap_disable
423 ;
8ca15ec8 424 ld_tracing = _getenv_ld("LD_TRACE_LOADED_OBJECTS");
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425 ld_utrace = _getenv_ld("LD_UTRACE");
426
427 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
428 ld_elf_hints_path = _PATH_ELF_HINTS;
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429
430 if (ld_debug != NULL && *ld_debug != '\0')
431 debug = 1;
432 dbg("%s is initialized, base address = %p", __progname,
433 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
434 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
435 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
436
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437 dbg("initializing thread locks");
438 lockdflt_init();
439
984263bc 440 /*
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441 * If we are resident we can skip work that we have already done.
442 * Note that the stack is reset and there is no Elf_Auxinfo
443 * when running from a resident image, and the static globals setup
444 * between here and resident_skip will have already been setup.
445 */
8ca15ec8 446 if (ld_resident)
33a8b578 447 goto resident_skip1;
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MD
448
449 /*
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450 * Load the main program, or process its program header if it is
451 * already loaded.
452 */
453 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
454 int fd = aux_info[AT_EXECFD]->a_un.a_val;
455 dbg("loading main program");
456 obj_main = map_object(fd, argv0, NULL);
457 close(fd);
458 if (obj_main == NULL)
459 die();
460 } else { /* Main program already loaded. */
461 const Elf_Phdr *phdr;
462 int phnum;
463 caddr_t entry;
464
465 dbg("processing main program's program header");
466 assert(aux_info[AT_PHDR] != NULL);
467 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
468 assert(aux_info[AT_PHNUM] != NULL);
469 phnum = aux_info[AT_PHNUM]->a_un.a_val;
470 assert(aux_info[AT_PHENT] != NULL);
471 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
472 assert(aux_info[AT_ENTRY] != NULL);
473 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
474 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
475 die();
476 }
477
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478 char buf[MAXPATHLEN];
479 if (aux_info[AT_EXECPATH] != 0) {
480 char *kexecpath;
481
482 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
483 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
484 if (kexecpath[0] == '/')
485 obj_main->path = kexecpath;
486 else if (getcwd(buf, sizeof(buf)) == NULL ||
487 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
488 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
489 obj_main->path = xstrdup(argv0);
490 else
491 obj_main->path = xstrdup(buf);
492 } else {
493 char resolved[MAXPATHLEN];
494 dbg("No AT_EXECPATH");
495 if (argv0[0] == '/') {
496 if (realpath(argv0, resolved) != NULL)
497 obj_main->path = xstrdup(resolved);
498 else
499 obj_main->path = xstrdup(argv0);
500 } else {
501 if (getcwd(buf, sizeof(buf)) != NULL
502 && strlcat(buf, "/", sizeof(buf)) < sizeof(buf)
503 && strlcat(buf, argv0, sizeof (buf)) < sizeof(buf)
504 && access(buf, R_OK) == 0
505 && realpath(buf, resolved) != NULL)
506 obj_main->path = xstrdup(resolved);
507 else
508 obj_main->path = xstrdup(argv0);
509 }
510 }
511 dbg("obj_main path %s", obj_main->path);
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512 obj_main->mainprog = true;
513
514 /*
515 * Get the actual dynamic linker pathname from the executable if
516 * possible. (It should always be possible.) That ensures that
517 * gdb will find the right dynamic linker even if a non-standard
518 * one is being used.
519 */
520 if (obj_main->interp != NULL &&
521 strcmp(obj_main->interp, obj_rtld.path) != 0) {
522 free(obj_rtld.path);
523 obj_rtld.path = xstrdup(obj_main->interp);
b7b05c9f 524 __progname = obj_rtld.path;
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525 }
526
c3098c28 527 digest_dynamic(obj_main, 0);
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528
529 linkmap_add(obj_main);
530 linkmap_add(&obj_rtld);
531
532 /* Link the main program into the list of objects. */
533 *obj_tail = obj_main;
534 obj_tail = &obj_main->next;
535 obj_count++;
fcf53d9b 536 obj_loads++;
984263bc 537 /* Make sure we don't call the main program's init and fini functions. */
fcf53d9b 538 obj_main->init = obj_main->fini = (Elf_Addr)NULL;
984263bc
MD
539
540 /* Initialize a fake symbol for resolving undefined weak references. */
541 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
fcf53d9b
JM
542 sym_zero.st_shndx = SHN_UNDEF;
543 sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
544
545 if (!libmap_disable)
546 libmap_disable = (bool)lm_init(libmap_override);
984263bc
MD
547
548 dbg("loading LD_PRELOAD libraries");
549 if (load_preload_objects() == -1)
550 die();
551 preload_tail = obj_tail;
552
553 dbg("loading needed objects");
fcf53d9b 554 if (load_needed_objects(obj_main, 0) == -1)
984263bc
MD
555 die();
556
557 /* Make a list of all objects loaded at startup. */
fcf53d9b 558 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc 559 objlist_push_tail(&list_main, obj);
fcf53d9b
JM
560 obj->refcount++;
561 }
562
563 dbg("checking for required versions");
564 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
565 die();
984263bc 566
33a8b578
MD
567resident_skip1:
568
984263bc
MD
569 if (ld_tracing) { /* We're done */
570 trace_loaded_objects(obj_main);
571 exit(0);
572 }
573
33a8b578
MD
574 if (ld_resident) /* XXX clean this up! */
575 goto resident_skip2;
576
fcf53d9b 577 if (_getenv_ld("LD_DUMP_REL_PRE") != NULL) {
4a8d9350
JS
578 dump_relocations(obj_main);
579 exit (0);
580 }
581
55b88cae
DX
582 /* setup TLS for main thread */
583 dbg("initializing initial thread local storage");
584 STAILQ_FOREACH(entry, &list_main, link) {
585 /*
586 * Allocate all the initial objects out of the static TLS
587 * block even if they didn't ask for it.
588 */
589 allocate_tls_offset(entry->obj);
590 }
a1eee96a
MD
591
592 tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA;
593
594 /*
595 * Do not try to allocate the TLS here, let libc do it itself.
596 * (crt1 for the program will call _init_tls())
597 */
55b88cae 598
6192271e 599 if (relocate_objects(obj_main,
c3098c28 600 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1)
6192271e 601 die();
984263bc 602
6192271e
MD
603 dbg("doing copy relocations");
604 if (do_copy_relocations(obj_main) == -1)
605 die();
1c76efe5 606
33a8b578
MD
607resident_skip2:
608
8ca15ec8 609 if (_getenv_ld("LD_RESIDENT_UNREGISTER_NOW")) {
33a8b578
MD
610 if (exec_sys_unregister(-1) < 0) {
611 dbg("exec_sys_unregister failed %d\n", errno);
612 exit(errno);
613 }
614 dbg("exec_sys_unregister success\n");
615 exit(0);
616 }
984263bc 617
fcf53d9b 618 if (_getenv_ld("LD_DUMP_REL_POST") != NULL) {
4a8d9350
JS
619 dump_relocations(obj_main);
620 exit (0);
621 }
622
984263bc
MD
623 dbg("initializing key program variables");
624 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
625 set_program_var("environ", env);
626
8ca15ec8
MD
627 if (_getenv_ld("LD_RESIDENT_REGISTER_NOW")) {
628 extern void resident_start(void);
629 ld_resident = 1;
630 if (exec_sys_register(resident_start) < 0) {
631 dbg("exec_sys_register failed %d\n", errno);
632 exit(errno);
633 }
634 dbg("exec_sys_register success\n");
635 exit(0);
636 }
637
984263bc
MD
638 /* Make a list of init functions to call. */
639 objlist_init(&initlist);
640 initlist_add_objects(obj_list, preload_tail, &initlist);
641
642 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
643
a1eee96a
MD
644 /*
645 * Do NOT call the initlist here, give libc a chance to set up
646 * the initial TLS segment. crt1 will then call _rtld_call_init().
647 */
8ca15ec8 648
984263bc
MD
649 dbg("transferring control to program entry point = %p", obj_main->entry);
650
651 /* Return the exit procedure and the program entry point. */
652 *exit_proc = rtld_exit;
653 *objp = obj_main;
654 return (func_ptr_type) obj_main->entry;
655}
656
a1eee96a
MD
657/*
658 * Call the initialization list for dynamically loaded libraries.
659 * (called from crt1.c).
660 */
661void
662_rtld_call_init(void)
663{
fcf53d9b
JM
664 RtldLockState lockstate;
665
666 wlock_acquire(rtld_bind_lock, &lockstate);
667 objlist_call_init(&initlist, &lockstate);
a1eee96a 668 objlist_clear(&initlist);
fcf53d9b 669 lock_release(rtld_bind_lock, &lockstate);
a1eee96a
MD
670}
671
984263bc 672Elf_Addr
4648abf3 673_rtld_bind(Obj_Entry *obj, Elf_Size reloff, void *stack)
984263bc
MD
674{
675 const Elf_Rel *rel;
676 const Elf_Sym *def;
677 const Obj_Entry *defobj;
678 Elf_Addr *where;
679 Elf_Addr target;
fcf53d9b 680 RtldLockState lockstate;
38e4b3b6 681 int do_reloc = 1;
984263bc 682
fcf53d9b
JM
683 rlock_acquire(rtld_bind_lock, &lockstate);
684 if (sigsetjmp(lockstate.env, 0) != 0)
685 lock_upgrade(rtld_bind_lock, &lockstate);
984263bc
MD
686 if (obj->pltrel)
687 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
688 else
689 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
690
691 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
692 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL);
693 if (def == NULL)
694 die();
695
696 target = (Elf_Addr)(defobj->relocbase + def->st_value);
697
698 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
699 defobj->strtab + def->st_name, basename(obj->path),
700 (void *)target, basename(defobj->path));
38e4b3b6
SS
701
702 /*
703 * If we have a function call tracing hook, and the
704 * hook would like to keep tracing this one function,
705 * prevent the relocation so we will wind up here
706 * the next time again.
707 *
708 * We don't want to functrace calls from the functracer
709 * to avoid recursive loops.
710 */
711 if (rtld_functrace != NULL && obj != rtld_functrace_obj) {
712 if (rtld_functrace(obj->path,
713 defobj->path,
714 defobj->strtab + def->st_name,
715 stack))
716 do_reloc = 0;
717 }
718
719 if (do_reloc)
fcf53d9b
JM
720 target = reloc_jmpslot(where, target, defobj, obj, rel);
721 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
722 return target;
723}
724
725/*
726 * Error reporting function. Use it like printf. If formats the message
727 * into a buffer, and sets things up so that the next call to dlerror()
728 * will return the message.
729 */
730void
731_rtld_error(const char *fmt, ...)
732{
733 static char buf[512];
734 va_list ap;
735
736 va_start(ap, fmt);
737 vsnprintf(buf, sizeof buf, fmt, ap);
738 error_message = buf;
739 va_end(ap);
740}
741
742/*
743 * Return a dynamically-allocated copy of the current error message, if any.
744 */
745static char *
746errmsg_save(void)
747{
748 return error_message == NULL ? NULL : xstrdup(error_message);
749}
750
751/*
752 * Restore the current error message from a copy which was previously saved
753 * by errmsg_save(). The copy is freed.
754 */
755static void
756errmsg_restore(char *saved_msg)
757{
758 if (saved_msg == NULL)
759 error_message = NULL;
760 else {
761 _rtld_error("%s", saved_msg);
762 free(saved_msg);
763 }
764}
765
1c76efe5 766const char *
984263bc
MD
767basename(const char *name)
768{
769 const char *p = strrchr(name, '/');
770 return p != NULL ? p + 1 : name;
771}
772
fcf53d9b
JM
773static struct utsname uts;
774
775static int
776origin_subst_one(char **res, const char *real, const char *kw, const char *subst,
777 char *may_free)
778{
779 const char *p, *p1;
780 char *res1;
781 int subst_len;
782 int kw_len;
783
784 res1 = *res = NULL;
785 p = real;
786 subst_len = kw_len = 0;
787 for (;;) {
788 p1 = strstr(p, kw);
789 if (p1 != NULL) {
790 if (subst_len == 0) {
791 subst_len = strlen(subst);
792 kw_len = strlen(kw);
793 }
794 if (*res == NULL) {
795 *res = xmalloc(PATH_MAX);
796 res1 = *res;
797 }
798 if ((res1 - *res) + subst_len + (p1 - p) >= PATH_MAX) {
799 _rtld_error("Substitution of %s in %s cannot be performed",
800 kw, real);
801 if (may_free != NULL)
802 free(may_free);
803 free(res);
804 return (false);
805 }
806 memcpy(res1, p, p1 - p);
807 res1 += p1 - p;
808 memcpy(res1, subst, subst_len);
809 res1 += subst_len;
810 p = p1 + kw_len;
811 } else {
812 if (*res == NULL) {
813 if (may_free != NULL)
814 *res = may_free;
815 else
816 *res = xstrdup(real);
817 return (true);
818 }
819 *res1 = '\0';
820 if (may_free != NULL)
821 free(may_free);
822 if (strlcat(res1, p, PATH_MAX - (res1 - *res)) >= PATH_MAX) {
823 free(res);
824 return (false);
825 }
826 return (true);
827 }
828 }
829}
830
831static char *
832origin_subst(const char *real, const char *origin_path)
833{
834 char *res1, *res2, *res3, *res4;
835
836 if (uts.sysname[0] == '\0') {
837 if (uname(&uts) != 0) {
838 _rtld_error("utsname failed: %d", errno);
839 return (NULL);
840 }
841 }
842 if (!origin_subst_one(&res1, real, "$ORIGIN", origin_path, NULL) ||
843 !origin_subst_one(&res2, res1, "$OSNAME", uts.sysname, res1) ||
844 !origin_subst_one(&res3, res2, "$OSREL", uts.release, res2) ||
845 !origin_subst_one(&res4, res3, "$PLATFORM", uts.machine, res3))
846 return (NULL);
847 return (res4);
848}
849
984263bc
MD
850static void
851die(void)
852{
853 const char *msg = dlerror();
854
855 if (msg == NULL)
856 msg = "Fatal error";
857 errx(1, "%s", msg);
858}
859
860/*
861 * Process a shared object's DYNAMIC section, and save the important
862 * information in its Obj_Entry structure.
863 */
864static void
c3098c28 865digest_dynamic(Obj_Entry *obj, int early)
984263bc
MD
866{
867 const Elf_Dyn *dynp;
868 Needed_Entry **needed_tail = &obj->needed;
869 const Elf_Dyn *dyn_rpath = NULL;
fcf53d9b 870 const Elf_Dyn *dyn_soname = NULL;
984263bc
MD
871 int plttype = DT_REL;
872
fcf53d9b 873 obj->bind_now = false;
984263bc
MD
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
fcf53d9b
JM
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
984263bc
MD
955 case DT_HASH:
956 {
d697cc44 957 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
984263bc
MD
958 (obj->relocbase + 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 }
964 break;
965
966 case DT_NEEDED:
967 if (!obj->rtld) {
968 Needed_Entry *nep = NEW(Needed_Entry);
969 nep->name = dynp->d_un.d_val;
970 nep->obj = NULL;
971 nep->next = NULL;
972
973 *needed_tail = nep;
974 needed_tail = &nep->next;
975 }
976 break;
977
978 case DT_PLTGOT:
979 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
980 break;
981
982 case DT_TEXTREL:
983 obj->textrel = true;
984 break;
985
986 case DT_SYMBOLIC:
987 obj->symbolic = true;
988 break;
989
990 case DT_RPATH:
167f7029 991 case DT_RUNPATH: /* XXX: process separately */
984263bc
MD
992 /*
993 * We have to wait until later to process this, because we
994 * might not have gotten the address of the string table yet.
995 */
996 dyn_rpath = dynp;
997 break;
998
999 case DT_SONAME:
fcf53d9b 1000 dyn_soname = dynp;
984263bc
MD
1001 break;
1002
1003 case DT_INIT:
fcf53d9b 1004 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
984263bc
MD
1005 break;
1006
1007 case DT_FINI:
fcf53d9b 1008 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
984263bc
MD
1009 break;
1010
1011 case DT_DEBUG:
1012 /* XXX - not implemented yet */
c3098c28
SS
1013 if (!early)
1014 dbg("Filling in DT_DEBUG entry");
984263bc
MD
1015 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
1016 break;
1017
167f7029 1018 case DT_FLAGS:
fcf53d9b
JM
1019 if ((dynp->d_un.d_val & DF_ORIGIN) && trust)
1020 obj->z_origin = true;
167f7029
JS
1021 if (dynp->d_un.d_val & DF_SYMBOLIC)
1022 obj->symbolic = true;
1023 if (dynp->d_un.d_val & DF_TEXTREL)
1024 obj->textrel = true;
1025 if (dynp->d_un.d_val & DF_BIND_NOW)
1026 obj->bind_now = true;
8301820e
JM
1027 /*if (dynp->d_un.d_val & DF_STATIC_TLS)
1028 ;*/
167f7029
JS
1029 break;
1030
fcf53d9b
JM
1031 case DT_FLAGS_1:
1032 if (dynp->d_un.d_val & DF_1_NOOPEN)
1033 obj->z_noopen = true;
1034 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
1035 obj->z_origin = true;
8301820e
JM
1036 /*if (dynp->d_un.d_val & DF_1_GLOBAL)
1037 XXX ;*/
fcf53d9b
JM
1038 if (dynp->d_un.d_val & DF_1_BIND_NOW)
1039 obj->bind_now = true;
1040 if (dynp->d_un.d_val & DF_1_NODELETE)
1041 obj->z_nodelete = true;
1042 break;
1043
984263bc 1044 default:
fcf53d9b
JM
1045 if (!early) {
1046 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
1047 (long)dynp->d_tag);
1048 }
984263bc
MD
1049 break;
1050 }
1051 }
1052
1053 obj->traced = false;
1054
1055 if (plttype == DT_RELA) {
1056 obj->pltrela = (const Elf_Rela *) obj->pltrel;
1057 obj->pltrel = NULL;
1058 obj->pltrelasize = obj->pltrelsize;
1059 obj->pltrelsize = 0;
1060 }
1061
fcf53d9b
JM
1062 if (obj->z_origin && obj->origin_path == NULL) {
1063 obj->origin_path = xmalloc(PATH_MAX);
1064 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1)
1065 die();
1066 }
1067
1068 if (dyn_rpath != NULL) {
1069 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
1070 if (obj->z_origin)
1071 obj->rpath = origin_subst(obj->rpath, obj->origin_path);
1072 }
1073
1074 if (dyn_soname != NULL)
1075 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
984263bc
MD
1076}
1077
1078/*
1079 * Process a shared object's program header. This is used only for the
1080 * main program, when the kernel has already loaded the main program
1081 * into memory before calling the dynamic linker. It creates and
1082 * returns an Obj_Entry structure.
1083 */
1084static Obj_Entry *
1085digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
1086{
1087 Obj_Entry *obj;
1088 const Elf_Phdr *phlimit = phdr + phnum;
1089 const Elf_Phdr *ph;
1090 int nsegs = 0;
1091
1092 obj = obj_new();
1093 for (ph = phdr; ph < phlimit; ph++) {
fcf53d9b
JM
1094 if (ph->p_type != PT_PHDR)
1095 continue;
984263bc 1096
fcf53d9b
JM
1097 obj->phdr = phdr;
1098 obj->phsize = ph->p_memsz;
1099 obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
1100 break;
1101 }
1102
1103 for (ph = phdr; ph < phlimit; ph++) {
1104 switch (ph->p_type) {
984263bc
MD
1105
1106 case PT_INTERP:
fcf53d9b 1107 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
984263bc
MD
1108 break;
1109
1110 case PT_LOAD:
1111 if (nsegs == 0) { /* First load segment */
1112 obj->vaddrbase = trunc_page(ph->p_vaddr);
fcf53d9b 1113 obj->mapbase = obj->vaddrbase + obj->relocbase;
984263bc
MD
1114 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
1115 obj->vaddrbase;
1116 } else { /* Last load segment */
1117 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1118 obj->vaddrbase;
1119 }
1120 nsegs++;
1121 break;
1122
1123 case PT_DYNAMIC:
fcf53d9b 1124 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
984263bc 1125 break;
55b88cae
DX
1126
1127 case PT_TLS:
1128 obj->tlsindex = 1;
1129 obj->tlssize = ph->p_memsz;
1130 obj->tlsalign = ph->p_align;
1131 obj->tlsinitsize = ph->p_filesz;
fcf53d9b 1132 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
55b88cae 1133 break;
984263bc
MD
1134 }
1135 }
1136 if (nsegs < 1) {
1137 _rtld_error("%s: too few PT_LOAD segments", path);
1138 return NULL;
1139 }
1140
1141 obj->entry = entry;
1142 return obj;
1143}
1144
1145static Obj_Entry *
1146dlcheck(void *handle)
1147{
1148 Obj_Entry *obj;
1149
1150 for (obj = obj_list; obj != NULL; obj = obj->next)
1151 if (obj == (Obj_Entry *) handle)
1152 break;
1153
1154 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1155 _rtld_error("Invalid shared object handle %p", handle);
1156 return NULL;
1157 }
1158 return obj;
1159}
1160
1161/*
1162 * If the given object is already in the donelist, return true. Otherwise
1163 * add the object to the list and return false.
1164 */
1165static bool
1166donelist_check(DoneList *dlp, const Obj_Entry *obj)
1167{
1168 unsigned int i;
1169
1170 for (i = 0; i < dlp->num_used; i++)
1171 if (dlp->objs[i] == obj)
1172 return true;
1173 /*
1174 * Our donelist allocation should always be sufficient. But if
1175 * our threads locking isn't working properly, more shared objects
1176 * could have been loaded since we allocated the list. That should
1177 * never happen, but we'll handle it properly just in case it does.
1178 */
1179 if (dlp->num_used < dlp->num_alloc)
1180 dlp->objs[dlp->num_used++] = obj;
1181 return false;
1182}
1183
1184/*
1185 * Hash function for symbol table lookup. Don't even think about changing
1186 * this. It is specified by the System V ABI.
1187 */
1188unsigned long
1189elf_hash(const char *name)
1190{
1191 const unsigned char *p = (const unsigned char *) name;
1192 unsigned long h = 0;
1193 unsigned long g;
1194
1195 while (*p != '\0') {
1196 h = (h << 4) + *p++;
1197 if ((g = h & 0xf0000000) != 0)
1198 h ^= g >> 24;
1199 h &= ~g;
1200 }
1201 return h;
1202}
1203
1204/*
1205 * Find the library with the given name, and return its full pathname.
1206 * The returned string is dynamically allocated. Generates an error
1207 * message and returns NULL if the library cannot be found.
1208 *
1209 * If the second argument is non-NULL, then it refers to an already-
1210 * loaded shared object, whose library search path will be searched.
1211 *
1212 * The search order is:
984263bc 1213 * LD_LIBRARY_PATH
4e390e27 1214 * rpath in the referencing file
984263bc
MD
1215 * ldconfig hints
1216 * /usr/lib
1217 */
1218static char *
fcf53d9b 1219find_library(const char *xname, const Obj_Entry *refobj)
984263bc
MD
1220{
1221 char *pathname;
fcf53d9b 1222 char *name;
984263bc 1223
fcf53d9b
JM
1224 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */
1225 if (xname[0] != '/' && !trust) {
984263bc 1226 _rtld_error("Absolute pathname required for shared object \"%s\"",
fcf53d9b 1227 xname);
984263bc
MD
1228 return NULL;
1229 }
fcf53d9b
JM
1230 if (refobj != NULL && refobj->z_origin)
1231 return origin_subst(xname, refobj->origin_path);
1232 else
1233 return xstrdup(xname);
984263bc
MD
1234 }
1235
fcf53d9b
JM
1236 if (libmap_disable || (refobj == NULL) ||
1237 (name = lm_find(refobj->path, xname)) == NULL)
1238 name = (char *)xname;
1239
984263bc
MD
1240 dbg(" Searching for \"%s\"", name);
1241
1242 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
1243 (refobj != NULL &&
1244 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1245 (pathname = search_library_path(name, gethints())) != NULL ||
1246 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
1247 return pathname;
1248
446c0d3a
JS
1249 if(refobj != NULL && refobj->path != NULL) {
1250 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
1251 name, basename(refobj->path));
1252 } else {
1253 _rtld_error("Shared object \"%s\" not found", name);
1254 }
984263bc
MD
1255 return NULL;
1256}
1257
1258/*
1259 * Given a symbol number in a referencing object, find the corresponding
1260 * definition of the symbol. Returns a pointer to the symbol, or NULL if
1261 * no definition was found. Returns a pointer to the Obj_Entry of the
1262 * defining object via the reference parameter DEFOBJ_OUT.
1263 */
1264const Elf_Sym *
1265find_symdef(unsigned long symnum, const Obj_Entry *refobj,
fcf53d9b 1266 const Obj_Entry **defobj_out, int flags, SymCache *cache)
984263bc
MD
1267{
1268 const Elf_Sym *ref;
1269 const Elf_Sym *def;
1270 const Obj_Entry *defobj;
fcf53d9b 1271 const Ver_Entry *ventry;
984263bc
MD
1272 const char *name;
1273 unsigned long hash;
1274
1275 /*
1276 * If we have already found this symbol, get the information from
1277 * the cache.
1278 */
1279 if (symnum >= refobj->nchains)
1280 return NULL; /* Bad object */
1281 if (cache != NULL && cache[symnum].sym != NULL) {
1282 *defobj_out = cache[symnum].obj;
1283 return cache[symnum].sym;
1284 }
1285
1286 ref = refobj->symtab + symnum;
1287 name = refobj->strtab + ref->st_name;
984263bc
MD
1288 defobj = NULL;
1289
0e588128
SS
1290 /*
1291 * We don't have to do a full scale lookup if the symbol is local.
1292 * We know it will bind to the instance in this load module; to
1293 * which we already have a pointer (ie ref). By not doing a lookup,
1294 * we not only improve performance, but it also avoids unresolvable
1295 * symbols when local symbols are not in the hash table.
1296 *
1297 * This might occur for TLS module relocations, which simply use
1298 * symbol 0.
1299 */
1300 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1301 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
c3098c28
SS
1302 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1303 symnum);
1304 }
fcf53d9b 1305 ventry = fetch_ventry(refobj, symnum);
0e588128 1306 hash = elf_hash(name);
fcf53d9b 1307 def = symlook_default(name, hash, refobj, &defobj, ventry, flags);
0e588128 1308 } else {
c3098c28
SS
1309 def = ref;
1310 defobj = refobj;
0e588128 1311 }
984263bc
MD
1312
1313 /*
1314 * If we found no definition and the reference is weak, treat the
1315 * symbol as having the value zero.
1316 */
1317 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1318 def = &sym_zero;
1319 defobj = obj_main;
1320 }
1321
1322 if (def != NULL) {
1323 *defobj_out = defobj;
1324 /* Record the information in the cache to avoid subsequent lookups. */
1325 if (cache != NULL) {
1326 cache[symnum].sym = def;
1327 cache[symnum].obj = defobj;
1328 }
fcf53d9b
JM
1329 } else {
1330 if (refobj != &obj_rtld)
1331 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1332 }
984263bc
MD
1333 return def;
1334}
1335
1336/*
1337 * Return the search path from the ldconfig hints file, reading it if
1338 * necessary. Returns NULL if there are problems with the hints file,
1339 * or if the search path there is empty.
1340 */
1341static const char *
1342gethints(void)
1343{
1344 static char *hints;
1345
1346 if (hints == NULL) {
1347 int fd;
1348 struct elfhints_hdr hdr;
1349 char *p;
1350
1351 /* Keep from trying again in case the hints file is bad. */
1352 hints = "";
1353
fcf53d9b 1354 if ((fd = open(ld_elf_hints_path, O_RDONLY)) == -1)
984263bc
MD
1355 return NULL;
1356 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1357 hdr.magic != ELFHINTS_MAGIC ||
1358 hdr.version != 1) {
1359 close(fd);
1360 return NULL;
1361 }
1362 p = xmalloc(hdr.dirlistlen + 1);
1363 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
fcf53d9b 1364 read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) {
984263bc
MD
1365 free(p);
1366 close(fd);
1367 return NULL;
1368 }
1369 hints = p;
1370 close(fd);
1371 }
1372 return hints[0] != '\0' ? hints : NULL;
1373}
1374
1375static void
1376init_dag(Obj_Entry *root)
1377{
1378 DoneList donelist;
1379
fcf53d9b
JM
1380 if (root->dag_inited)
1381 return;
984263bc
MD
1382 donelist_init(&donelist);
1383 init_dag1(root, root, &donelist);
1384}
1385
1386static void
1387init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp)
1388{
1389 const Needed_Entry *needed;
1390
1391 if (donelist_check(dlp, obj))
1392 return;
fcf53d9b 1393
984263bc
MD
1394 objlist_push_tail(&obj->dldags, root);
1395 objlist_push_tail(&root->dagmembers, obj);
1396 for (needed = obj->needed; needed != NULL; needed = needed->next)
1397 if (needed->obj != NULL)
1398 init_dag1(root, needed->obj, dlp);
fcf53d9b 1399 root->dag_inited = true;
984263bc
MD
1400}
1401
1402/*
1403 * Initialize the dynamic linker. The argument is the address at which
1404 * the dynamic linker has been mapped into memory. The primary task of
1405 * this function is to relocate the dynamic linker.
1406 */
1407static void
1408init_rtld(caddr_t mapbase)
1409{
c3098c28
SS
1410 Obj_Entry objtmp; /* Temporary rtld object */
1411
984263bc
MD
1412 /*
1413 * Conjure up an Obj_Entry structure for the dynamic linker.
1414 *
fcf53d9b
JM
1415 * The "path" member can't be initialized yet because string constants
1416 * cannot yet be accessed. Below we will set it correctly.
984263bc 1417 */
4648abf3 1418 memset(&objtmp, 0, sizeof(objtmp));
c3098c28
SS
1419 objtmp.path = NULL;
1420 objtmp.rtld = true;
1421 objtmp.mapbase = mapbase;
984263bc 1422#ifdef PIC
c3098c28 1423 objtmp.relocbase = mapbase;
984263bc 1424#endif
fcf53d9b 1425 if (RTLD_IS_DYNAMIC()) {
c3098c28
SS
1426 objtmp.dynamic = rtld_dynamic(&objtmp);
1427 digest_dynamic(&objtmp, 1);
1428 assert(objtmp.needed == NULL);
1429 assert(!objtmp.textrel);
984263bc
MD
1430
1431 /*
1432 * Temporarily put the dynamic linker entry into the object list, so
1433 * that symbols can be found.
1434 */
984263bc 1435
c3098c28 1436 relocate_objects(&objtmp, true, &objtmp);
984263bc
MD
1437 }
1438
c3098c28 1439 /* Initialize the object list. */
984263bc 1440 obj_tail = &obj_list;
c3098c28
SS
1441
1442 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1443 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
984263bc
MD
1444
1445 /* Replace the path with a dynamically allocated copy. */
c3098c28 1446 obj_rtld.path = xstrdup(PATH_RTLD);
984263bc
MD
1447
1448 r_debug.r_brk = r_debug_state;
1449 r_debug.r_state = RT_CONSISTENT;
1450}
1451
1452/*
1453 * Add the init functions from a needed object list (and its recursive
1454 * needed objects) to "list". This is not used directly; it is a helper
1455 * function for initlist_add_objects(). The write lock must be held
1456 * when this function is called.
1457 */
1458static void
1459initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1460{
1461 /* Recursively process the successor needed objects. */
1462 if (needed->next != NULL)
1463 initlist_add_neededs(needed->next, list);
1464
1465 /* Process the current needed object. */
1466 if (needed->obj != NULL)
1467 initlist_add_objects(needed->obj, &needed->obj->next, list);
1468}
1469
1470/*
1471 * Scan all of the DAGs rooted in the range of objects from "obj" to
1472 * "tail" and add their init functions to "list". This recurses over
1473 * the DAGs and ensure the proper init ordering such that each object's
1474 * needed libraries are initialized before the object itself. At the
1475 * same time, this function adds the objects to the global finalization
1476 * list "list_fini" in the opposite order. The write lock must be
1477 * held when this function is called.
1478 */
1479static void
1480initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1481{
fcf53d9b 1482 if (obj->init_scanned || obj->init_done)
984263bc 1483 return;
fcf53d9b 1484 obj->init_scanned = true;
984263bc
MD
1485
1486 /* Recursively process the successor objects. */
1487 if (&obj->next != tail)
1488 initlist_add_objects(obj->next, tail, list);
1489
1490 /* Recursively process the needed objects. */
1491 if (obj->needed != NULL)
1492 initlist_add_neededs(obj->needed, list);
1493
1494 /* Add the object to the init list. */
fcf53d9b 1495 if (obj->init != (Elf_Addr)NULL)
984263bc
MD
1496 objlist_push_tail(list, obj);
1497
1498 /* Add the object to the global fini list in the reverse order. */
fcf53d9b 1499 if (obj->fini != (Elf_Addr)NULL && !obj->on_fini_list) {
984263bc 1500 objlist_push_head(&list_fini, obj);
fcf53d9b
JM
1501 obj->on_fini_list = true;
1502 }
984263bc
MD
1503}
1504
fcf53d9b
JM
1505#ifndef FPTR_TARGET
1506#define FPTR_TARGET(f) ((Elf_Addr) (f))
1507#endif
1508
984263bc
MD
1509static bool
1510is_exported(const Elf_Sym *def)
1511{
d697cc44 1512 Elf_Addr value;
984263bc
MD
1513 const func_ptr_type *p;
1514
d697cc44 1515 value = (Elf_Addr)(obj_rtld.relocbase + def->st_value);
fcf53d9b
JM
1516 for (p = exports; *p != NULL; p++)
1517 if (FPTR_TARGET(*p) == value)
984263bc
MD
1518 return true;
1519 return false;
1520}
1521
1522/*
1523 * Given a shared object, traverse its list of needed objects, and load
1524 * each of them. Returns 0 on success. Generates an error message and
1525 * returns -1 on failure.
1526 */
1527static int
fcf53d9b 1528load_needed_objects(Obj_Entry *first, int flags)
984263bc 1529{
fcf53d9b 1530 Obj_Entry *obj, *obj1;
984263bc
MD
1531
1532 for (obj = first; obj != NULL; obj = obj->next) {
1533 Needed_Entry *needed;
1534
1535 for (needed = obj->needed; needed != NULL; needed = needed->next) {
fcf53d9b
JM
1536 obj1 = needed->obj = load_object(obj->strtab + needed->name, obj,
1537 flags & ~RTLD_LO_NOLOAD);
1538 if (obj1 == NULL && !ld_tracing)
984263bc 1539 return -1;
fcf53d9b
JM
1540 if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) {
1541 dbg("obj %s nodelete", obj1->path);
1542 init_dag(obj1);
1543 ref_dag(obj1);
1544 obj1->ref_nodel = true;
984263bc
MD
1545 }
1546 }
1547 }
fcf53d9b 1548 return (0);
984263bc
MD
1549}
1550
38e4b3b6
SS
1551#define RTLD_FUNCTRACE "_rtld_functrace"
1552
984263bc
MD
1553static int
1554load_preload_objects(void)
1555{
1556 char *p = ld_preload;
1557 static const char delim[] = " \t:;";
1558
1559 if (p == NULL)
eecd52b2 1560 return 0;
984263bc
MD
1561
1562 p += strspn(p, delim);
1563 while (*p != '\0') {
1564 size_t len = strcspn(p, delim);
984263bc 1565 char savech;
38e4b3b6
SS
1566 Obj_Entry *obj;
1567 const Elf_Sym *sym;
984263bc
MD
1568
1569 savech = p[len];
1570 p[len] = '\0';
fcf53d9b 1571 obj = load_object(p, NULL, 0);
38e4b3b6 1572 if (obj == NULL)
984263bc
MD
1573 return -1; /* XXX - cleanup */
1574 p[len] = savech;
1575 p += len;
1576 p += strspn(p, delim);
38e4b3b6
SS
1577
1578 /* Check for the magic tracing function */
fcf53d9b 1579 sym = symlook_obj(RTLD_FUNCTRACE, elf_hash(RTLD_FUNCTRACE), obj, NULL, 1);
38e4b3b6
SS
1580 if (sym != NULL) {
1581 rtld_functrace = (void *)(obj->relocbase + sym->st_value);
1582 rtld_functrace_obj = obj;
1583 }
984263bc 1584 }
fcf53d9b 1585 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
984263bc
MD
1586 return 0;
1587}
1588
1589/*
fcf53d9b
JM
1590 * Load a shared object into memory, if it is not already loaded.
1591 *
1592 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1593 * on failure.
b6a22d96
JS
1594 */
1595static Obj_Entry *
fcf53d9b 1596load_object(const char *name, const Obj_Entry *refobj, int flags)
b6a22d96
JS
1597{
1598 Obj_Entry *obj;
fcf53d9b
JM
1599 int fd = -1;
1600 struct stat sb;
1601 char *path;
b6a22d96 1602
fcf53d9b
JM
1603 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1604 if (object_match_name(obj, name))
1605 return obj;
b6a22d96 1606
fcf53d9b
JM
1607 path = find_library(name, refobj);
1608 if (path == NULL)
1609 return NULL;
2d6b58a8 1610
fcf53d9b
JM
1611 /*
1612 * If we didn't find a match by pathname, open the file and check
1613 * again by device and inode. This avoids false mismatches caused
1614 * by multiple links or ".." in pathnames.
1615 *
1616 * To avoid a race, we open the file and use fstat() rather than
1617 * using stat().
1618 */
1619 if ((fd = open(path, O_RDONLY)) == -1) {
2d6b58a8 1620 _rtld_error("Cannot open \"%s\"", path);
fcf53d9b
JM
1621 free(path);
1622 return NULL;
2d6b58a8 1623 }
fcf53d9b 1624 if (fstat(fd, &sb) == -1) {
2d6b58a8 1625 _rtld_error("Cannot fstat \"%s\"", path);
fcf53d9b
JM
1626 close(fd);
1627 free(path);
2d6b58a8
JS
1628 return NULL;
1629 }
fcf53d9b
JM
1630 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1631 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
2d6b58a8 1632 break;
fcf53d9b
JM
1633 if (obj != NULL) {
1634 object_add_name(obj, name);
1635 free(path);
1636 close(fd);
1637 return obj;
1638 }
1639 if (flags & RTLD_LO_NOLOAD) {
1640 free(path);
8bdeb8d3 1641 close(fd);
fcf53d9b 1642 return (NULL);
2d6b58a8
JS
1643 }
1644
fcf53d9b
JM
1645 /* First use of this object, so we must map it in */
1646 obj = do_load_object(fd, name, path, &sb, flags);
1647 if (obj == NULL)
1648 free(path);
1649 close(fd);
1650
1651 return obj;
2d6b58a8
JS
1652}
1653
984263bc 1654static Obj_Entry *
fcf53d9b
JM
1655do_load_object(int fd, const char *name, char *path, struct stat *sbp,
1656 int flags)
984263bc
MD
1657{
1658 Obj_Entry *obj;
fcf53d9b 1659 struct statfs fs;
984263bc 1660
fcf53d9b
JM
1661 /*
1662 * but first, make sure that environment variables haven't been
1663 * used to circumvent the noexec flag on a filesystem.
1664 */
1665 if (dangerous_ld_env) {
1666 if (fstatfs(fd, &fs) != 0) {
1667 _rtld_error("Cannot fstatfs \"%s\"", path);
1668 return NULL;
1669 }
1670 if (fs.f_flags & MNT_NOEXEC) {
1671 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
1672 return NULL;
1673 }
984263bc 1674 }
2d6b58a8 1675 dbg("loading \"%s\"", path);
fcf53d9b
JM
1676 obj = map_object(fd, path, sbp);
1677 if (obj == NULL)
2d6b58a8 1678 return NULL;
984263bc 1679
fcf53d9b 1680 object_add_name(obj, name);
2d6b58a8 1681 obj->path = path;
c3098c28 1682 digest_dynamic(obj, 0);
fcf53d9b
JM
1683 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
1684 RTLD_LO_DLOPEN) {
1685 dbg("refusing to load non-loadable \"%s\"", obj->path);
1686 _rtld_error("Cannot dlopen non-loadable %s", obj->path);
1687 munmap(obj->mapbase, obj->mapsize);
1688 obj_free(obj);
1689 return (NULL);
1690 }
984263bc 1691
2d6b58a8
JS
1692 *obj_tail = obj;
1693 obj_tail = &obj->next;
1694 obj_count++;
fcf53d9b 1695 obj_loads++;
2d6b58a8 1696 linkmap_add(obj); /* for GDB & dlinfo() */
984263bc 1697
139b8f34
SW
1698 dbg(" %p .. %p: %s", obj->mapbase,
1699 obj->mapbase + obj->mapsize - 1, obj->path);
2d6b58a8 1700 if (obj->textrel)
fcf53d9b
JM
1701 dbg(" WARNING: %s has impure text", obj->path);
1702 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
1703 obj->path);
984263bc 1704
984263bc
MD
1705 return obj;
1706}
1707
984263bc
MD
1708static Obj_Entry *
1709obj_from_addr(const void *addr)
1710{
984263bc
MD
1711 Obj_Entry *obj;
1712
984263bc 1713 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc
MD
1714 if (addr < (void *) obj->mapbase)
1715 continue;
c6873e56 1716 if (addr < (void *) (obj->mapbase + obj->mapsize))
984263bc
MD
1717 return obj;
1718 }
1719 return NULL;
1720}
1721
1722/*
1723 * Call the finalization functions for each of the objects in "list"
fcf53d9b
JM
1724 * belonging to the DAG of "root" and referenced once. If NULL "root"
1725 * is specified, every finalization function will be called regardless
1726 * of the reference count and the list elements won't be freed. All of
1727 * the objects are expected to have non-NULL fini functions.
984263bc
MD
1728 */
1729static void
fcf53d9b 1730objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
984263bc
MD
1731{
1732 Objlist_Entry *elm;
1733 char *saved_msg;
1734
fcf53d9b
JM
1735 assert(root == NULL || root->refcount == 1);
1736
984263bc
MD
1737 /*
1738 * Preserve the current error message since a fini function might
1739 * call into the dynamic linker and overwrite it.
1740 */
1741 saved_msg = errmsg_save();
fcf53d9b
JM
1742 do {
1743 STAILQ_FOREACH(elm, list, link) {
1744 if (root != NULL && (elm->obj->refcount != 1 ||
1745 objlist_find(&root->dagmembers, elm->obj) == NULL))
1746 continue;
1747 dbg("calling fini function for %s at %p", elm->obj->path,
1748 (void *)elm->obj->fini);
1749 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 0, 0,
1750 elm->obj->path);
1751 /* Remove object from fini list to prevent recursive invocation. */
1752 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1753 /*
1754 * XXX: If a dlopen() call references an object while the
1755 * fini function is in progress, we might end up trying to
1756 * unload the referenced object in dlclose() or the object
1757 * won't be unloaded although its fini function has been
1758 * called.
1759 */
1760 lock_release(rtld_bind_lock, lockstate);
1761 call_initfini_pointer(elm->obj, elm->obj->fini);
1762 wlock_acquire(rtld_bind_lock, lockstate);
1763 /* No need to free anything if process is going down. */
1764 if (root != NULL)
1765 free(elm);
1766 /*
1767 * We must restart the list traversal after every fini call
1768 * because a dlclose() call from the fini function or from
1769 * another thread might have modified the reference counts.
1770 */
1771 break;
984263bc 1772 }
fcf53d9b 1773 } while (elm != NULL);
984263bc
MD
1774 errmsg_restore(saved_msg);
1775}
1776
1777/*
1778 * Call the initialization functions for each of the objects in
1779 * "list". All of the objects are expected to have non-NULL init
1780 * functions.
1781 */
1782static void
fcf53d9b 1783objlist_call_init(Objlist *list, RtldLockState *lockstate)
984263bc
MD
1784{
1785 Objlist_Entry *elm;
fcf53d9b 1786 Obj_Entry *obj;
984263bc
MD
1787 char *saved_msg;
1788
1789 /*
fcf53d9b
JM
1790 * Clean init_scanned flag so that objects can be rechecked and
1791 * possibly initialized earlier if any of vectors called below
1792 * cause the change by using dlopen.
1793 */
1794 for (obj = obj_list; obj != NULL; obj = obj->next)
1795 obj->init_scanned = false;
1796
1797 /*
984263bc
MD
1798 * Preserve the current error message since an init function might
1799 * call into the dynamic linker and overwrite it.
1800 */
1801 saved_msg = errmsg_save();
1802 STAILQ_FOREACH(elm, list, link) {
fcf53d9b
JM
1803 if (elm->obj->init_done) /* Initialized early. */
1804 continue;
1805 dbg("calling init function for %s at %p", elm->obj->path,
1806 (void *)elm->obj->init);
1807 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 0, 0,
1808 elm->obj->path);
1809 /*
1810 * Race: other thread might try to use this object before current
1811 * one completes the initilization. Not much can be done here
1812 * without better locking.
1813 */
1814 elm->obj->init_done = true;
1815 lock_release(rtld_bind_lock, lockstate);
1816 call_initfini_pointer(elm->obj, elm->obj->init);
1817 wlock_acquire(rtld_bind_lock, lockstate);
984263bc
MD
1818 }
1819 errmsg_restore(saved_msg);
1820}
1821
1822static void
1823objlist_clear(Objlist *list)
1824{
1825 Objlist_Entry *elm;
1826
1827 while (!STAILQ_EMPTY(list)) {
1828 elm = STAILQ_FIRST(list);
1829 STAILQ_REMOVE_HEAD(list, link);
1830 free(elm);
1831 }
1832}
1833
1834static Objlist_Entry *
1835objlist_find(Objlist *list, const Obj_Entry *obj)
1836{
1837 Objlist_Entry *elm;
1838
1839 STAILQ_FOREACH(elm, list, link)
1840 if (elm->obj == obj)
1841 return elm;
1842 return NULL;
1843}
1844
1845static void
1846objlist_init(Objlist *list)
1847{
1848 STAILQ_INIT(list);
1849}
1850
1851static void
1852objlist_push_head(Objlist *list, Obj_Entry *obj)
1853{
1854 Objlist_Entry *elm;
1855
1856 elm = NEW(Objlist_Entry);
1857 elm->obj = obj;
1858 STAILQ_INSERT_HEAD(list, elm, link);
1859}
1860
1861static void
1862objlist_push_tail(Objlist *list, Obj_Entry *obj)
1863{
1864 Objlist_Entry *elm;
1865
1866 elm = NEW(Objlist_Entry);
1867 elm->obj = obj;
1868 STAILQ_INSERT_TAIL(list, elm, link);
1869}
1870
1871static void
1872objlist_remove(Objlist *list, Obj_Entry *obj)
1873{
1874 Objlist_Entry *elm;
1875
1876 if ((elm = objlist_find(list, obj)) != NULL) {
1877 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1878 free(elm);
1879 }
1880}
1881
1882/*
984263bc
MD
1883 * Relocate newly-loaded shared objects. The argument is a pointer to
1884 * the Obj_Entry for the first such object. All objects from the first
1885 * to the end of the list of objects are relocated. Returns 0 on success,
1886 * or -1 on failure.
1887 */
1888static int
c3098c28 1889relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj)
984263bc
MD
1890{
1891 Obj_Entry *obj;
1892
1893 for (obj = first; obj != NULL; obj = obj->next) {
c3098c28 1894 if (obj != rtldobj)
984263bc
MD
1895 dbg("relocating \"%s\"", obj->path);
1896 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL ||
1897 obj->symtab == NULL || obj->strtab == NULL) {
1898 _rtld_error("%s: Shared object has no run-time symbol table",
1899 obj->path);
1900 return -1;
1901 }
1902
1903 if (obj->textrel) {
1904 /* There are relocations to the write-protected text segment. */
1905 if (mprotect(obj->mapbase, obj->textsize,
1906 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
1907 _rtld_error("%s: Cannot write-enable text segment: %s",
1908 obj->path, strerror(errno));
1909 return -1;
1910 }
1911 }
1912
1913 /* Process the non-PLT relocations. */
c3098c28 1914 if (reloc_non_plt(obj, rtldobj))
984263bc
MD
1915 return -1;
1916
4b89341e
MD
1917 /*
1918 * Reprotect the text segment. Make sure it is included in the
1919 * core dump since we modified it. This unfortunately causes the
1920 * entire text segment to core-out but we don't have much of a
1921 * choice. We could try to only reenable core dumps on pages
1922 * in which relocations occured but that is likely most of the text
1923 * pages anyway, and even that would not work because the rest of
1924 * the text pages would wind up as a read-only OBJT_DEFAULT object
1925 * (created due to our modifications) backed by the original OBJT_VNODE
1926 * object, and the ELF coredump code is currently only able to dump
1927 * vnode records for pure vnode-backed mappings, not vnode backings
1928 * to memory objects.
1929 */
1930 if (obj->textrel) {
1931 madvise(obj->mapbase, obj->textsize, MADV_CORE);
984263bc
MD
1932 if (mprotect(obj->mapbase, obj->textsize,
1933 PROT_READ|PROT_EXEC) == -1) {
1934 _rtld_error("%s: Cannot write-protect text segment: %s",
1935 obj->path, strerror(errno));
1936 return -1;
1937 }
1938 }
1939
1940 /* Process the PLT relocations. */
1941 if (reloc_plt(obj) == -1)
1942 return -1;
1943 /* Relocate the jump slots if we are doing immediate binding. */
167f7029 1944 if (obj->bind_now || bind_now)
984263bc
MD
1945 if (reloc_jmpslots(obj) == -1)
1946 return -1;
1947
1948
1949 /*
1950 * Set up the magic number and version in the Obj_Entry. These
1951 * were checked in the crt1.o from the original ElfKit, so we
1952 * set them for backward compatibility.
1953 */
1954 obj->magic = RTLD_MAGIC;
1955 obj->version = RTLD_VERSION;
1956
1957 /* Set the special PLT or GOT entries. */
1958 init_pltgot(obj);
1959 }
1960
1961 return 0;
1962}
1963
1964/*
1965 * Cleanup procedure. It will be called (by the atexit mechanism) just
1966 * before the process exits.
1967 */
1968static void
1969rtld_exit(void)
1970{
fcf53d9b 1971 RtldLockState lockstate;
984263bc 1972
fcf53d9b 1973 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc 1974 dbg("rtld_exit()");
fcf53d9b 1975 objlist_call_fini(&list_fini, NULL, &lockstate);
984263bc 1976 /* No need to remove the items from the list, since we are exiting. */
fcf53d9b
JM
1977 if (!libmap_disable)
1978 lm_fini();
1979 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
1980}
1981
1982static void *
1983path_enumerate(const char *path, path_enum_proc callback, void *arg)
1984{
1985 if (path == NULL)
1986 return (NULL);
1987
1988 path += strspn(path, ":;");
1989 while (*path != '\0') {
1990 size_t len;
1991 char *res;
1992
1993 len = strcspn(path, ":;");
1994 res = callback(path, len, arg);
1995
1996 if (res != NULL)
1997 return (res);
1998
1999 path += len;
2000 path += strspn(path, ":;");
2001 }
2002
2003 return (NULL);
2004}
2005
2006struct try_library_args {
2007 const char *name;
2008 size_t namelen;
2009 char *buffer;
2010 size_t buflen;
2011};
2012
2013static void *
2014try_library_path(const char *dir, size_t dirlen, void *param)
2015{
2016 struct try_library_args *arg;
2017
2018 arg = param;
2019 if (*dir == '/' || trust) {
2020 char *pathname;
2021
2022 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
2023 return (NULL);
2024
2025 pathname = arg->buffer;
2026 strncpy(pathname, dir, dirlen);
2027 pathname[dirlen] = '/';
2028 strcpy(pathname + dirlen + 1, arg->name);
2029
2030 dbg(" Trying \"%s\"", pathname);
2031 if (access(pathname, F_OK) == 0) { /* We found it */
2032 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
2033 strcpy(pathname, arg->buffer);
2034 return (pathname);
2035 }
2036 }
2037 return (NULL);
2038}
2039
2040static char *
2041search_library_path(const char *name, const char *path)
2042{
2043 char *p;
2044 struct try_library_args arg;
2045
2046 if (path == NULL)
2047 return NULL;
2048
2049 arg.name = name;
2050 arg.namelen = strlen(name);
2051 arg.buffer = xmalloc(PATH_MAX);
2052 arg.buflen = PATH_MAX;
2053
2054 p = path_enumerate(path, try_library_path, &arg);
2055
2056 free(arg.buffer);
2057
2058 return (p);
2059}
2060
2061int
2062dlclose(void *handle)
2063{
2064 Obj_Entry *root;
fcf53d9b 2065 RtldLockState lockstate;
984263bc 2066
fcf53d9b 2067 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2068 root = dlcheck(handle);
2069 if (root == NULL) {
fcf53d9b 2070 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2071 return -1;
2072 }
fcf53d9b
JM
2073 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
2074 root->path);
984263bc
MD
2075
2076 /* Unreference the object and its dependencies. */
2077 root->dl_refcount--;
139b8f34 2078
fcf53d9b 2079 if (root->refcount == 1) {
984263bc 2080 /*
fcf53d9b
JM
2081 * The object will be no longer referenced, so we must unload it.
2082 * First, call the fini functions.
984263bc 2083 */
fcf53d9b
JM
2084 objlist_call_fini(&list_fini, root, &lockstate);
2085
2086 unref_dag(root);
984263bc
MD
2087
2088 /* Finish cleaning up the newly-unreferenced objects. */
2089 GDB_STATE(RT_DELETE,&root->linkmap);
2090 unload_object(root);
2091 GDB_STATE(RT_CONSISTENT,NULL);
fcf53d9b
JM
2092 } else
2093 unref_dag(root);
2094
2095 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
2096 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2097 return 0;
2098}
2099
fcf53d9b 2100char *
984263bc
MD
2101dlerror(void)
2102{
2103 char *msg = error_message;
2104 error_message = NULL;
2105 return msg;
2106}
2107
984263bc
MD
2108void *
2109dlopen(const char *name, int mode)
2110{
2111 Obj_Entry **old_obj_tail;
2112 Obj_Entry *obj;
2113 Objlist initlist;
fcf53d9b
JM
2114 RtldLockState lockstate;
2115 int result, lo_flags;
984263bc 2116
fcf53d9b 2117 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
984263bc
MD
2118 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
2119 if (ld_tracing != NULL)
2120 environ = (char **)*get_program_var_addr("environ");
fcf53d9b
JM
2121 lo_flags = RTLD_LO_DLOPEN;
2122 if (mode & RTLD_NODELETE)
2123 lo_flags |= RTLD_LO_NODELETE;
2124 if (mode & RTLD_NOLOAD)
2125 lo_flags |= RTLD_LO_NOLOAD;
2126 if (ld_tracing != NULL)
2127 lo_flags |= RTLD_LO_TRACE;
984263bc
MD
2128
2129 objlist_init(&initlist);
2130
fcf53d9b 2131 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2132 GDB_STATE(RT_ADD,NULL);
2133
2134 old_obj_tail = obj_tail;
2135 obj = NULL;
2136 if (name == NULL) {
2137 obj = obj_main;
2138 obj->refcount++;
2139 } else {
fcf53d9b 2140 obj = load_object(name, obj_main, lo_flags);
984263bc
MD
2141 }
2142
2143 if (obj) {
2144 obj->dl_refcount++;
139b8f34 2145 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
984263bc
MD
2146 objlist_push_tail(&list_global, obj);
2147 mode &= RTLD_MODEMASK;
2148 if (*old_obj_tail != NULL) { /* We loaded something new. */
2149 assert(*old_obj_tail == obj);
fcf53d9b
JM
2150 result = load_needed_objects(obj, RTLD_LO_DLOPEN);
2151 init_dag(obj);
2152 ref_dag(obj);
2153 if (result != -1)
2154 result = rtld_verify_versions(&obj->dagmembers);
984263bc
MD
2155 if (result != -1 && ld_tracing)
2156 goto trace;
984263bc 2157 if (result == -1 ||
fcf53d9b 2158 (relocate_objects(obj, mode == RTLD_NOW, &obj_rtld)) == -1) {
984263bc
MD
2159 obj->dl_refcount--;
2160 unref_dag(obj);
2161 if (obj->refcount == 0)
2162 unload_object(obj);
2163 obj = NULL;
2164 } else {
2165 /* Make list of init functions to call. */
2166 initlist_add_objects(obj, &obj->next, &initlist);
2167 }
fcf53d9b
JM
2168 } else {
2169
2170 /*
2171 * Bump the reference counts for objects on this DAG. If
2172 * this is the first dlopen() call for the object that was
2173 * already loaded as a dependency, initialize the dag
2174 * starting at it.
2175 */
2176 init_dag(obj);
2177 ref_dag(obj);
2178
2179 if ((lo_flags & RTLD_LO_TRACE) != 0)
2180 goto trace;
2181 }
2182 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
2183 obj->z_nodelete) && !obj->ref_nodel) {
2184 dbg("obj %s nodelete", obj->path);
2185 ref_dag(obj);
2186 obj->z_nodelete = obj->ref_nodel = true;
2187 }
984263bc
MD
2188 }
2189
fcf53d9b
JM
2190 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
2191 name);
984263bc
MD
2192 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
2193
fcf53d9b
JM
2194 /* Call the init functions. */
2195 objlist_call_init(&initlist, &lockstate);
984263bc 2196 objlist_clear(&initlist);
fcf53d9b 2197 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2198 return obj;
2199trace:
2200 trace_loaded_objects(obj);
fcf53d9b 2201 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2202 exit(0);
2203}
2204
fcf53d9b
JM
2205static void *
2206do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
2207 int flags)
984263bc 2208{
fcf53d9b
JM
2209 DoneList donelist;
2210 const Obj_Entry *obj, *defobj;
2211 const Elf_Sym *def, *symp;
984263bc 2212 unsigned long hash;
fcf53d9b 2213 RtldLockState lockstate;
984263bc
MD
2214
2215 hash = elf_hash(name);
2216 def = NULL;
2217 defobj = NULL;
fcf53d9b 2218 flags |= SYMLOOK_IN_PLT;
984263bc 2219
fcf53d9b
JM
2220 rlock_acquire(rtld_bind_lock, &lockstate);
2221 if (sigsetjmp(lockstate.env, 0) != 0)
2222 lock_upgrade(rtld_bind_lock, &lockstate);
984263bc
MD
2223 if (handle == NULL || handle == RTLD_NEXT ||
2224 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
984263bc 2225
984263bc
MD
2226 if ((obj = obj_from_addr(retaddr)) == NULL) {
2227 _rtld_error("Cannot determine caller's shared object");
fcf53d9b 2228 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2229 return NULL;
2230 }
2231 if (handle == NULL) { /* Just the caller's shared object. */
fcf53d9b 2232 def = symlook_obj(name, hash, obj, ve, flags);
984263bc
MD
2233 defobj = obj;
2234 } else if (handle == RTLD_NEXT || /* Objects after caller's */
2235 handle == RTLD_SELF) { /* ... caller included */
2236 if (handle == RTLD_NEXT)
2237 obj = obj->next;
2238 for (; obj != NULL; obj = obj->next) {
fcf53d9b
JM
2239 if ((symp = symlook_obj(name, hash, obj, ve, flags)) != NULL) {
2240 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2241 def = symp;
2242 defobj = obj;
2243 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2244 break;
2245 }
2246 }
2247 }
2248 /*
2249 * Search the dynamic linker itself, and possibly resolve the
2250 * symbol from there. This is how the application links to
2251 * dynamic linker services such as dlopen.
2252 */
2253 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2254 symp = symlook_obj(name, hash, &obj_rtld, ve, flags);
2255 if (symp != NULL) {
2256 def = symp;
2257 defobj = &obj_rtld;
984263bc
MD
2258 }
2259 }
2260 } else {
2261 assert(handle == RTLD_DEFAULT);
fcf53d9b 2262 def = symlook_default(name, hash, obj, &defobj, ve, flags);
984263bc
MD
2263 }
2264 } else {
2265 if ((obj = dlcheck(handle)) == NULL) {
fcf53d9b 2266 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2267 return NULL;
2268 }
2269
fb0c631e 2270 donelist_init(&donelist);
984263bc 2271 if (obj->mainprog) {
984263bc 2272 /* Search main program and all libraries loaded by it. */
fcf53d9b
JM
2273 def = symlook_list(name, hash, &list_main, &defobj, ve, flags,
2274 &donelist);
2275
2276 /*
2277 * We do not distinguish between 'main' object and global scope.
2278 * If symbol is not defined by objects loaded at startup, continue
2279 * search among dynamically loaded objects with RTLD_GLOBAL
2280 * scope.
2281 */
2282 if (def == NULL)
2283 def = symlook_list(name, hash, &list_global, &defobj, ve,
2284 flags, &donelist);
984263bc 2285 } else {
cebaf0af
SS
2286 Needed_Entry fake;
2287
fcf53d9b 2288 /* Search the whole DAG rooted at the given object. */
cebaf0af
SS
2289 fake.next = NULL;
2290 fake.obj = (Obj_Entry *)obj;
2291 fake.name = 0;
fcf53d9b
JM
2292 def = symlook_needed(name, hash, &fake, &defobj, ve, flags,
2293 &donelist);
984263bc
MD
2294 }
2295 }
2296
2297 if (def != NULL) {
fcf53d9b
JM
2298 lock_release(rtld_bind_lock, &lockstate);
2299
2300 /*
2301 * The value required by the caller is derived from the value
2302 * of the symbol. For the ia64 architecture, we need to
2303 * construct a function descriptor which the caller can use to
2304 * call the function with the right 'gp' value. For other
2305 * architectures and for non-functions, the value is simply
2306 * the relocated value of the symbol.
2307 */
2308 if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
2309 return make_function_pointer(def, defobj);
2310 else
2311 return defobj->relocbase + def->st_value;
984263bc
MD
2312 }
2313
2314 _rtld_error("Undefined symbol \"%s\"", name);
fcf53d9b 2315 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2316 return NULL;
2317}
2318
fcf53d9b
JM
2319void *
2320dlsym(void *handle, const char *name)
2321{
2322 return do_dlsym(handle, name, __builtin_return_address(0), NULL,
2323 SYMLOOK_DLSYM);
2324}
2325
2326dlfunc_t
2327dlfunc(void *handle, const char *name)
2328{
2329 union {
2330 void *d;
2331 dlfunc_t f;
2332 } rv;
2333
2334 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
2335 SYMLOOK_DLSYM);
2336 return (rv.f);
2337}
2338
2339void *
2340dlvsym(void *handle, const char *name, const char *version)
2341{
2342 Ver_Entry ventry;
2343
2344 ventry.name = version;
2345 ventry.file = NULL;
2346 ventry.hash = elf_hash(version);
2347 ventry.flags= 0;
2348 return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
2349 SYMLOOK_DLSYM);
2350}
2351
2352int
2353_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
2354{
2355 const Obj_Entry *obj;
2356 RtldLockState lockstate;
2357
2358 rlock_acquire(rtld_bind_lock, &lockstate);
2359 obj = obj_from_addr(addr);
2360 if (obj == NULL) {
2361 _rtld_error("No shared object contains address");
2362 lock_release(rtld_bind_lock, &lockstate);
2363 return (0);
2364 }
2365 rtld_fill_dl_phdr_info(obj, phdr_info);
2366 lock_release(rtld_bind_lock, &lockstate);
2367 return (1);
2368}
2369
984263bc
MD
2370int
2371dladdr(const void *addr, Dl_info *info)
2372{
2373 const Obj_Entry *obj;
2374 const Elf_Sym *def;
2375 void *symbol_addr;
2376 unsigned long symoffset;
fcf53d9b
JM
2377 RtldLockState lockstate;
2378
2379 rlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2380 obj = obj_from_addr(addr);
2381 if (obj == NULL) {
2382 _rtld_error("No shared object contains address");
fcf53d9b 2383 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2384 return 0;
2385 }
2386 info->dli_fname = obj->path;
2387 info->dli_fbase = obj->mapbase;
60233e58 2388 info->dli_saddr = NULL;
984263bc
MD
2389 info->dli_sname = NULL;
2390
2391 /*
2392 * Walk the symbol list looking for the symbol whose address is
2393 * closest to the address sent in.
2394 */
2395 for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
2396 def = obj->symtab + symoffset;
2397
2398 /*
2399 * For skip the symbol if st_shndx is either SHN_UNDEF or
2400 * SHN_COMMON.
2401 */
2402 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
2403 continue;
2404
2405 /*
2406 * If the symbol is greater than the specified address, or if it
2407 * is further away from addr than the current nearest symbol,
2408 * then reject it.
2409 */
2410 symbol_addr = obj->relocbase + def->st_value;
2411 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
2412 continue;
2413
2414 /* Update our idea of the nearest symbol. */
2415 info->dli_sname = obj->strtab + def->st_name;
2416 info->dli_saddr = symbol_addr;
2417
2418 /* Exact match? */
2419 if (info->dli_saddr == addr)
2420 break;
2421 }
fcf53d9b 2422 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2423 return 1;
2424}
2425
2426int
2427dlinfo(void *handle, int request, void *p)
2428{
2429 const Obj_Entry *obj;
fcf53d9b 2430 RtldLockState lockstate;
984263bc
MD
2431 int error;
2432
fcf53d9b 2433 rlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2434
2435 if (handle == NULL || handle == RTLD_SELF) {
2436 void *retaddr;
2437
2438 retaddr = __builtin_return_address(0); /* __GNUC__ only */
2439 if ((obj = obj_from_addr(retaddr)) == NULL)
2440 _rtld_error("Cannot determine caller's shared object");
2441 } else
2442 obj = dlcheck(handle);
2443
2444 if (obj == NULL) {
fcf53d9b 2445 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2446 return (-1);
2447 }
2448
2449 error = 0;
2450 switch (request) {
2451 case RTLD_DI_LINKMAP:
2452 *((struct link_map const **)p) = &obj->linkmap;
2453 break;
2454 case RTLD_DI_ORIGIN:
2455 error = rtld_dirname(obj->path, p);
2456 break;
2457
2458 case RTLD_DI_SERINFOSIZE:
2459 case RTLD_DI_SERINFO:
2460 error = do_search_info(obj, request, (struct dl_serinfo *)p);
2461 break;
2462
2463 default:
2464 _rtld_error("Invalid request %d passed to dlinfo()", request);
2465 error = -1;
2466 }
2467
fcf53d9b
JM
2468 lock_release(rtld_bind_lock, &lockstate);
2469
2470 return (error);
2471}
2472
2473static void
2474rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
2475{
2476
2477 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
2478 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ?
2479 STAILQ_FIRST(&obj->names)->name : obj->path;
2480 phdr_info->dlpi_phdr = obj->phdr;
2481 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
2482 phdr_info->dlpi_tls_modid = obj->tlsindex;
2483 phdr_info->dlpi_tls_data = obj->tlsinit;
2484 phdr_info->dlpi_adds = obj_loads;
2485 phdr_info->dlpi_subs = obj_loads - obj_count;
2486}
2487
2488int
2489dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
2490{
2491 struct dl_phdr_info phdr_info;
2492 const Obj_Entry *obj;
2493 RtldLockState bind_lockstate, phdr_lockstate;
2494 int error;
2495
2496 wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
2497 rlock_acquire(rtld_bind_lock, &bind_lockstate);
2498
2499 error = 0;
2500
2501 for (obj = obj_list; obj != NULL; obj = obj->next) {
2502 rtld_fill_dl_phdr_info(obj, &phdr_info);
2503 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0)
2504 break;
2505
2506 }
2507 lock_release(rtld_bind_lock, &bind_lockstate);
2508 lock_release(rtld_phdr_lock, &phdr_lockstate);
984263bc
MD
2509
2510 return (error);
2511}
2512
2513struct fill_search_info_args {
2514 int request;
2515 unsigned int flags;
2516 Dl_serinfo *serinfo;
2517 Dl_serpath *serpath;
2518 char *strspace;
2519};
2520
2521static void *
2522fill_search_info(const char *dir, size_t dirlen, void *param)
2523{
2524 struct fill_search_info_args *arg;
2525
2526 arg = param;
2527
2528 if (arg->request == RTLD_DI_SERINFOSIZE) {
2529 arg->serinfo->dls_cnt ++;
fcf53d9b 2530 arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1;
984263bc
MD
2531 } else {
2532 struct dl_serpath *s_entry;
2533
2534 s_entry = arg->serpath;
2535 s_entry->dls_name = arg->strspace;
2536 s_entry->dls_flags = arg->flags;
2537
2538 strncpy(arg->strspace, dir, dirlen);
2539 arg->strspace[dirlen] = '\0';
2540
2541 arg->strspace += dirlen + 1;
2542 arg->serpath++;
2543 }
2544
2545 return (NULL);
2546}
2547
2548static int
2549do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
2550{
2551 struct dl_serinfo _info;
2552 struct fill_search_info_args args;
2553
2554 args.request = RTLD_DI_SERINFOSIZE;
2555 args.serinfo = &_info;
2556
2557 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2558 _info.dls_cnt = 0;
2559
2560 path_enumerate(ld_library_path, fill_search_info, &args);
2561 path_enumerate(obj->rpath, fill_search_info, &args);
2562 path_enumerate(gethints(), fill_search_info, &args);
2563 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
2564
2565
2566 if (request == RTLD_DI_SERINFOSIZE) {
2567 info->dls_size = _info.dls_size;
2568 info->dls_cnt = _info.dls_cnt;
2569 return (0);
2570 }
2571
2572 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
2573 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
2574 return (-1);
2575 }
2576
2577 args.request = RTLD_DI_SERINFO;
2578 args.serinfo = info;
2579 args.serpath = &info->dls_serpath[0];
2580 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
2581
2582 args.flags = LA_SER_LIBPATH;
2583 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
2584 return (-1);
2585
2586 args.flags = LA_SER_RUNPATH;
2587 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
2588 return (-1);
2589
2590 args.flags = LA_SER_CONFIG;
2591 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
2592 return (-1);
2593
2594 args.flags = LA_SER_DEFAULT;
2595 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
2596 return (-1);
2597 return (0);
2598}
2599
2600static int
2601rtld_dirname(const char *path, char *bname)
2602{
2603 const char *endp;
2604
2605 /* Empty or NULL string gets treated as "." */
2606 if (path == NULL || *path == '\0') {
2607 bname[0] = '.';
2608 bname[1] = '\0';
2609 return (0);
2610 }
2611
2612 /* Strip trailing slashes */
2613 endp = path + strlen(path) - 1;
2614 while (endp > path && *endp == '/')
2615 endp--;
2616
2617 /* Find the start of the dir */
2618 while (endp > path && *endp != '/')
2619 endp--;
2620
2621 /* Either the dir is "/" or there are no slashes */
2622 if (endp == path) {
2623 bname[0] = *endp == '/' ? '/' : '.';
2624 bname[1] = '\0';
2625 return (0);
2626 } else {
2627 do {
2628 endp--;
2629 } while (endp > path && *endp == '/');
2630 }
2631
2632 if (endp - path + 2 > PATH_MAX)
2633 {
2634 _rtld_error("Filename is too long: %s", path);
2635 return(-1);
2636 }
2637
2638 strncpy(bname, path, endp - path + 1);
2639 bname[endp - path + 1] = '\0';
2640 return (0);
2641}
2642
fcf53d9b
JM
2643static int
2644rtld_dirname_abs(const char *path, char *base)
2645{
2646 char base_rel[PATH_MAX];
2647
2648 if (rtld_dirname(path, base) == -1)
2649 return (-1);
2650 if (base[0] == '/')
2651 return (0);
2652 if (getcwd(base_rel, sizeof(base_rel)) == NULL ||
2653 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) ||
2654 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel))
2655 return (-1);
2656 strcpy(base, base_rel);
2657 return (0);
2658}
2659
984263bc
MD
2660static void
2661linkmap_add(Obj_Entry *obj)
2662{
2663 struct link_map *l = &obj->linkmap;
2664 struct link_map *prev;
2665
2666 obj->linkmap.l_name = obj->path;
2667 obj->linkmap.l_addr = obj->mapbase;
2668 obj->linkmap.l_ld = obj->dynamic;
2669#ifdef __mips__
2670 /* GDB needs load offset on MIPS to use the symbols */
2671 obj->linkmap.l_offs = obj->relocbase;
2672#endif
2673
2674 if (r_debug.r_map == NULL) {
2675 r_debug.r_map = l;
2676 return;
2677 }
2678
2679 /*
2680 * Scan to the end of the list, but not past the entry for the
2681 * dynamic linker, which we want to keep at the very end.
2682 */
2683 for (prev = r_debug.r_map;
2684 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
2685 prev = prev->l_next)
2686 ;
2687
2688 /* Link in the new entry. */
2689 l->l_prev = prev;
2690 l->l_next = prev->l_next;
2691 if (l->l_next != NULL)
2692 l->l_next->l_prev = l;
2693 prev->l_next = l;
2694}
2695
2696static void
2697linkmap_delete(Obj_Entry *obj)
2698{
2699 struct link_map *l = &obj->linkmap;
2700
2701 if (l->l_prev == NULL) {
2702 if ((r_debug.r_map = l->l_next) != NULL)
2703 l->l_next->l_prev = NULL;
2704 return;
2705 }
2706
2707 if ((l->l_prev->l_next = l->l_next) != NULL)
2708 l->l_next->l_prev = l->l_prev;
2709}
2710
2711/*
2712 * Function for the debugger to set a breakpoint on to gain control.
2713 *
2714 * The two parameters allow the debugger to easily find and determine
2715 * what the runtime loader is doing and to whom it is doing it.
2716 *
2717 * When the loadhook trap is hit (r_debug_state, set at program
2718 * initialization), the arguments can be found on the stack:
2719 *
2720 * +8 struct link_map *m
2721 * +4 struct r_debug *rd
2722 * +0 RetAddr
2723 */
2724void
2725r_debug_state(struct r_debug* rd, struct link_map *m)
2726{
8301820e
JM
2727 /*
2728 * The following is a hack to force the compiler to emit calls to
2729 * this function, even when optimizing. If the function is empty,
2730 * the compiler is not obliged to emit any code for calls to it,
2731 * even when marked __noinline. However, gdb depends on those
2732 * calls being made.
2733 */
2734 __asm __volatile("" : : : "memory");
984263bc
MD
2735}
2736
2737/*
2738 * Get address of the pointer variable in the main program.
2739 */
2740static const void **
2741get_program_var_addr(const char *name)
2742{
2743 const Obj_Entry *obj;
2744 unsigned long hash;
2745
2746 hash = elf_hash(name);
2747 for (obj = obj_main; obj != NULL; obj = obj->next) {
2748 const Elf_Sym *def;
2749
fcf53d9b 2750 if ((def = symlook_obj(name, hash, obj, NULL, 0)) != NULL) {
984263bc
MD
2751 const void **addr;
2752
2753 addr = (const void **)(obj->relocbase + def->st_value);
2754 return addr;
2755 }
2756 }
fcf53d9b 2757 return (NULL);
984263bc
MD
2758}
2759
2760/*
2761 * Set a pointer variable in the main program to the given value. This
2762 * is used to set key variables such as "environ" before any of the
2763 * init functions are called.
2764 */
2765static void
2766set_program_var(const char *name, const void *value)
2767{
2768 const void **addr;
2769
2770 if ((addr = get_program_var_addr(name)) != NULL) {
2771 dbg("\"%s\": *%p <-- %p", name, addr, value);
2772 *addr = value;
2773 }
2774}
2775
2776/*
8ca15ec8
MD
2777 * This is a special version of getenv which is far more efficient
2778 * at finding LD_ environment vars.
2779 */
2780static
2781const char *
2782_getenv_ld(const char *id)
2783{
2784 const char *envp;
2785 int i, j;
2786 int idlen = strlen(id);
2787
2788 if (ld_index == LD_ARY_CACHE)
2789 return(getenv(id));
2790 if (ld_index == 0) {
2791 for (i = j = 0; (envp = environ[i]) != NULL && j < LD_ARY_CACHE; ++i) {
2792 if (envp[0] == 'L' && envp[1] == 'D' && envp[2] == '_')
2793 ld_ary[j++] = envp;
2794 }
2795 if (j == 0)
2796 ld_ary[j++] = "";
2797 ld_index = j;
2798 }
2799 for (i = ld_index - 1; i >= 0; --i) {
2800 if (strncmp(ld_ary[i], id, idlen) == 0 && ld_ary[i][idlen] == '=')
2801 return(ld_ary[i] + idlen + 1);
2802 }
2803 return(NULL);
2804}
2805
2806/*
984263bc
MD
2807 * Given a symbol name in a referencing object, find the corresponding
2808 * definition of the symbol. Returns a pointer to the symbol, or NULL if
2809 * no definition was found. Returns a pointer to the Obj_Entry of the
2810 * defining object via the reference parameter DEFOBJ_OUT.
2811 */
2812static const Elf_Sym *
fcf53d9b
JM
2813symlook_default(const char *name, unsigned long hash, const Obj_Entry *refobj,
2814 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags)
984263bc
MD
2815{
2816 DoneList donelist;
2817 const Elf_Sym *def;
2818 const Elf_Sym *symp;
2819 const Obj_Entry *obj;
2820 const Obj_Entry *defobj;
2821 const Objlist_Entry *elm;
2822 def = NULL;
2823 defobj = NULL;
2824 donelist_init(&donelist);
2825
2826 /* Look first in the referencing object if linked symbolically. */
2827 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
fcf53d9b 2828 symp = symlook_obj(name, hash, refobj, ventry, flags);
984263bc
MD
2829 if (symp != NULL) {
2830 def = symp;
2831 defobj = refobj;
2832 }
2833 }
2834
2835 /* Search all objects loaded at program start up. */
2836 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
fcf53d9b
JM
2837 symp = symlook_list(name, hash, &list_main, &obj, ventry, flags,
2838 &donelist);
984263bc
MD
2839 if (symp != NULL &&
2840 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2841 def = symp;
2842 defobj = obj;
2843 }
2844 }
2845
2846 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
2847 STAILQ_FOREACH(elm, &list_global, link) {
2848 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2849 break;
fcf53d9b
JM
2850 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry,
2851 flags, &donelist);
984263bc
MD
2852 if (symp != NULL &&
2853 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2854 def = symp;
2855 defobj = obj;
2856 }
2857 }
2858
2859 /* Search all dlopened DAGs containing the referencing object. */
2860 STAILQ_FOREACH(elm, &refobj->dldags, link) {
2861 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2862 break;
fcf53d9b
JM
2863 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry,
2864 flags, &donelist);
984263bc
MD
2865 if (symp != NULL &&
2866 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2867 def = symp;
2868 defobj = obj;
2869 }
2870 }
2871
2872 /*
2873 * Search the dynamic linker itself, and possibly resolve the
2874 * symbol from there. This is how the application links to
2875 * dynamic linker services such as dlopen. Only the values listed
2876 * in the "exports" array can be resolved from the dynamic linker.
2877 */
2878 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
fcf53d9b 2879 symp = symlook_obj(name, hash, &obj_rtld, ventry, flags);
984263bc
MD
2880 if (symp != NULL && is_exported(symp)) {
2881 def = symp;
2882 defobj = &obj_rtld;
2883 }
2884 }
2885
2886 if (def != NULL)
2887 *defobj_out = defobj;
2888 return def;
2889}
2890
2891static const Elf_Sym *
fb0c631e 2892symlook_list(const char *name, unsigned long hash, const Objlist *objlist,
fcf53d9b
JM
2893 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags,
2894 DoneList *dlp)
984263bc
MD
2895{
2896 const Elf_Sym *symp;
2897 const Elf_Sym *def;
2898 const Obj_Entry *defobj;
2899 const Objlist_Entry *elm;
2900
2901 def = NULL;
2902 defobj = NULL;
2903 STAILQ_FOREACH(elm, objlist, link) {
2904 if (donelist_check(dlp, elm->obj))
2905 continue;
fcf53d9b 2906 if ((symp = symlook_obj(name, hash, elm->obj, ventry, flags)) != NULL) {
984263bc
MD
2907 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2908 def = symp;
2909 defobj = elm->obj;
2910 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2911 break;
2912 }
2913 }
2914 }
2915 if (def != NULL)
2916 *defobj_out = defobj;
2917 return def;
2918}
2919
2920/*
cebaf0af
SS
2921 * Search the symbol table of a shared object and all objects needed
2922 * by it for a symbol of the given name. Search order is
2923 * breadth-first. Returns a pointer to the symbol, or NULL if no
2924 * definition was found.
2925 */
2926static const Elf_Sym *
2927symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed,
fcf53d9b
JM
2928 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags,
2929 DoneList *dlp)
cebaf0af
SS
2930{
2931 const Elf_Sym *def, *def_w;
2932 const Needed_Entry *n;
2933 const Obj_Entry *obj, *defobj, *defobj1;
fcf53d9b 2934
cebaf0af
SS
2935 def = def_w = NULL;
2936 defobj = NULL;
2937 for (n = needed; n != NULL; n = n->next) {
fcf53d9b
JM
2938 if ((obj = n->obj) == NULL ||
2939 donelist_check(dlp, obj) ||
2940 (def = symlook_obj(name, hash, obj, ventry, flags)) == NULL)
2941 continue;
2942 defobj = obj;
2943 if (ELF_ST_BIND(def->st_info) != STB_WEAK) {
2944 *defobj_out = defobj;
2945 return (def);
cebaf0af
SS
2946 }
2947 }
2948 /*
2949 * There we come when either symbol definition is not found in
2950 * directly needed objects, or found symbol is weak.
2951 */
2952 for (n = needed; n != NULL; n = n->next) {
fcf53d9b
JM
2953 if ((obj = n->obj) == NULL)
2954 continue;
2955 def_w = symlook_needed(name, hash, obj->needed, &defobj1,
2956 ventry, flags, dlp);
2957 if (def_w == NULL)
2958 continue;
2959 if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) {
2960 def = def_w;
2961 defobj = defobj1;
2962 }
2963 if (ELF_ST_BIND(def_w->st_info) != STB_WEAK)
2964 break;
cebaf0af
SS
2965 }
2966 if (def != NULL)
fcf53d9b
JM
2967 *defobj_out = defobj;
2968 return (def);
cebaf0af
SS
2969}
2970
2971/*
984263bc 2972 * Search the symbol table of a single shared object for a symbol of
fcf53d9b
JM
2973 * the given name and version, if requested. Returns a pointer to the
2974 * symbol, or NULL if no definition was found.
984263bc
MD
2975 *
2976 * The symbol's hash value is passed in for efficiency reasons; that
2977 * eliminates many recomputations of the hash value.
2978 */
2979const Elf_Sym *
2980symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj,
fcf53d9b 2981 const Ver_Entry *ventry, int flags)
984263bc 2982{
fcf53d9b
JM
2983 unsigned long symnum;
2984 const Elf_Sym *vsymp;
2985 Elf_Versym verndx;
2986 int vcount;
984263bc 2987
fcf53d9b
JM
2988 if (obj->buckets == NULL)
2989 return NULL;
984263bc 2990
fcf53d9b
JM
2991 vsymp = NULL;
2992 vcount = 0;
2993 symnum = obj->buckets[hash % obj->nbuckets];
2994
2995 for (; symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
2996 const Elf_Sym *symp;
2997 const char *strp;
2998
2999 if (symnum >= obj->nchains)
3000 return NULL; /* Bad object */
3001
3002 symp = obj->symtab + symnum;
3003 strp = obj->strtab + symp->st_name;
3004
3005 switch (ELF_ST_TYPE(symp->st_info)) {
3006 case STT_FUNC:
3007 case STT_NOTYPE:
3008 case STT_OBJECT:
3009 if (symp->st_value == 0)
3010 continue;
3011 /* fallthrough */
3012 case STT_TLS:
3013 if (symp->st_shndx != SHN_UNDEF)
3014 break;
3015 else if (((flags & SYMLOOK_IN_PLT) == 0) &&
3016 (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
3017 break;
3018 /* fallthrough */
3019 default:
3020 continue;
3021 }
3022 if (name[0] != strp[0] || strcmp(name, strp) != 0)
3023 continue;
984263bc 3024
fcf53d9b
JM
3025 if (ventry == NULL) {
3026 if (obj->versyms != NULL) {
3027 verndx = VER_NDX(obj->versyms[symnum]);
3028 if (verndx > obj->vernum) {
3029 _rtld_error("%s: symbol %s references wrong version %d",
3030 obj->path, obj->strtab + symnum, verndx);
3031 continue;
3032 }
3033 /*
3034 * If we are not called from dlsym (i.e. this is a normal
3035 * relocation from unversioned binary), accept the symbol
3036 * immediately if it happens to have first version after
3037 * this shared object became versioned. Otherwise, if
3038 * symbol is versioned and not hidden, remember it. If it
3039 * is the only symbol with this name exported by the
3040 * shared object, it will be returned as a match at the
3041 * end of the function. If symbol is global (verndx < 2)
3042 * accept it unconditionally.
3043 */
3044 if ((flags & SYMLOOK_DLSYM) == 0 && verndx == VER_NDX_GIVEN)
3045 return symp;
3046 else if (verndx >= VER_NDX_GIVEN) {
3047 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) {
3048 if (vsymp == NULL)
3049 vsymp = symp;
3050 vcount ++;
3051 }
3052 continue;
3053 }
3054 }
3055 return symp;
3056 } else {
3057 if (obj->versyms == NULL) {
3058 if (object_match_name(obj, ventry->name)) {
3059 _rtld_error("%s: object %s should provide version %s for "
3060 "symbol %s", obj_rtld.path, obj->path, ventry->name,
3061 obj->strtab + symnum);
3062 continue;
3063 }
3064 } else {
3065 verndx = VER_NDX(obj->versyms[symnum]);
3066 if (verndx > obj->vernum) {
3067 _rtld_error("%s: symbol %s references wrong version %d",
3068 obj->path, obj->strtab + symnum, verndx);
3069 continue;
3070 }
3071 if (obj->vertab[verndx].hash != ventry->hash ||
3072 strcmp(obj->vertab[verndx].name, ventry->name)) {
3073 /*
3074 * Version does not match. Look if this is a global symbol
3075 * and if it is not hidden. If global symbol (verndx < 2)
3076 * is available, use it. Do not return symbol if we are
3077 * called by dlvsym, because dlvsym looks for a specific
3078 * version and default one is not what dlvsym wants.
3079 */
3080 if ((flags & SYMLOOK_DLSYM) ||
3081 (obj->versyms[symnum] & VER_NDX_HIDDEN) ||
3082 (verndx >= VER_NDX_GIVEN))
3083 continue;
3084 }
3085 }
3086 return symp;
984263bc
MD
3087 }
3088 }
fcf53d9b 3089 return (vcount == 1) ? vsymp : NULL;
984263bc
MD
3090}
3091
3092static void
3093trace_loaded_objects(Obj_Entry *obj)
3094{
fcf53d9b 3095 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers;
984263bc
MD
3096 int c;
3097
8ca15ec8 3098 if ((main_local = _getenv_ld("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
984263bc
MD
3099 main_local = "";
3100
8ca15ec8 3101 if ((fmt1 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL)
984263bc
MD
3102 fmt1 = "\t%o => %p (%x)\n";
3103
8ca15ec8 3104 if ((fmt2 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL)
984263bc
MD
3105 fmt2 = "\t%o (%x)\n";
3106
fcf53d9b
JM
3107 list_containers = _getenv_ld("LD_TRACE_LOADED_OBJECTS_ALL");
3108
984263bc
MD
3109 for (; obj; obj = obj->next) {
3110 Needed_Entry *needed;
3111 char *name, *path;
3112 bool is_lib;
3113
fcf53d9b
JM
3114 if (list_containers && obj->needed != NULL)
3115 printf("%s:\n", obj->path);
984263bc
MD
3116 for (needed = obj->needed; needed; needed = needed->next) {
3117 if (needed->obj != NULL) {
fcf53d9b 3118 if (needed->obj->traced && !list_containers)
984263bc
MD
3119 continue;
3120 needed->obj->traced = true;
3121 path = needed->obj->path;
3122 } else
3123 path = "not found";
3124
3125 name = (char *)obj->strtab + needed->name;
3126 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
3127
3128 fmt = is_lib ? fmt1 : fmt2;
3129 while ((c = *fmt++) != '\0') {
3130 switch (c) {
3131 default:
3132 putchar(c);
3133 continue;
3134 case '\\':
3135 switch (c = *fmt) {
3136 case '\0':
3137 continue;
3138 case 'n':
3139 putchar('\n');
3140 break;
3141 case 't':
3142 putchar('\t');
3143 break;
3144 }
3145 break;
3146 case '%':
3147 switch (c = *fmt) {
3148 case '\0':
3149 continue;
3150 case '%':
3151 default:
3152 putchar(c);
3153 break;
3154 case 'A':
3155 printf("%s", main_local);
3156 break;
3157 case 'a':
3158 printf("%s", obj_main->path);
3159 break;
3160 case 'o':
3161 printf("%s", name);
3162 break;
984263bc
MD
3163 case 'p':
3164 printf("%s", path);
3165 break;
3166 case 'x':
3167 printf("%p", needed->obj ? needed->obj->mapbase : 0);
3168 break;
3169 }
3170 break;
3171 }
3172 ++fmt;
3173 }
3174 }
3175 }
3176}
3177
3178/*
3179 * Unload a dlopened object and its dependencies from memory and from
3180 * our data structures. It is assumed that the DAG rooted in the
3181 * object has already been unreferenced, and that the object has a
3182 * reference count of 0.
3183 */
3184static void
3185unload_object(Obj_Entry *root)
3186{
3187 Obj_Entry *obj;
3188 Obj_Entry **linkp;
3189
3190 assert(root->refcount == 0);
3191
3192 /*
3193 * Pass over the DAG removing unreferenced objects from
3194 * appropriate lists.
fcf53d9b 3195 */
984263bc
MD
3196 unlink_object(root);
3197
3198 /* Unmap all objects that are no longer referenced. */
3199 linkp = &obj_list->next;
3200 while ((obj = *linkp) != NULL) {
3201 if (obj->refcount == 0) {
fcf53d9b
JM
3202 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
3203 obj->path);
984263bc
MD
3204 dbg("unloading \"%s\"", obj->path);
3205 munmap(obj->mapbase, obj->mapsize);
3206 linkmap_delete(obj);
3207 *linkp = obj->next;
3208 obj_count--;
3209 obj_free(obj);
3210 } else
3211 linkp = &obj->next;
3212 }
3213 obj_tail = linkp;
3214}
3215
3216static void
3217unlink_object(Obj_Entry *root)
3218{
984263bc
MD
3219 Objlist_Entry *elm;
3220
3221 if (root->refcount == 0) {
3222 /* Remove the object from the RTLD_GLOBAL list. */
3223 objlist_remove(&list_global, root);
3224
3225 /* Remove the object from all objects' DAG lists. */
fcf53d9b 3226 STAILQ_FOREACH(elm, &root->dagmembers, link) {
984263bc 3227 objlist_remove(&elm->obj->dldags, root);
fcf53d9b
JM
3228 if (elm->obj != root)
3229 unlink_object(elm->obj);
3230 }
984263bc 3231 }
fcf53d9b 3232}
984263bc 3233
fcf53d9b
JM
3234static void
3235ref_dag(Obj_Entry *root)
3236{
3237 Objlist_Entry *elm;
3238
3239 assert(root->dag_inited);
3240 STAILQ_FOREACH(elm, &root->dagmembers, link)
3241 elm->obj->refcount++;
984263bc
MD
3242}
3243
3244static void
3245unref_dag(Obj_Entry *root)
3246{
fcf53d9b 3247 Objlist_Entry *elm;
984263bc 3248
fcf53d9b
JM
3249 assert(root->dag_inited);
3250 STAILQ_FOREACH(elm, &root->dagmembers, link)
3251 elm->obj->refcount--;
984263bc 3252}
55b88cae
DX
3253
3254/*
3255 * Common code for MD __tls_get_addr().
3256 */
3257void *
fcf53d9b 3258tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset)
55b88cae
DX
3259{
3260 Elf_Addr* dtv = *dtvp;
fcf53d9b 3261 RtldLockState lockstate;
55b88cae
DX
3262
3263 /* Check dtv generation in case new modules have arrived */
3264 if (dtv[0] != tls_dtv_generation) {
3265 Elf_Addr* newdtv;
3266 int to_copy;
3267
fcf53d9b 3268 wlock_acquire(rtld_bind_lock, &lockstate);
55b88cae
DX
3269 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
3270 to_copy = dtv[1];
3271 if (to_copy > tls_max_index)
3272 to_copy = tls_max_index;
3273 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
3274 newdtv[0] = tls_dtv_generation;
3275 newdtv[1] = tls_max_index;
3276 free(dtv);
fcf53d9b 3277 lock_release(rtld_bind_lock, &lockstate);
bc633d63 3278 *dtvp = newdtv;
55b88cae
DX
3279 }
3280
3281 /* Dynamically allocate module TLS if necessary */
3282 if (!dtv[index + 1]) {
fcf53d9b
JM
3283 /* Signal safe, wlock will block out signals. */
3284 wlock_acquire(rtld_bind_lock, &lockstate);
3285 if (!dtv[index + 1])
55b88cae 3286 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
fcf53d9b 3287 lock_release(rtld_bind_lock, &lockstate);
55b88cae 3288 }
55b88cae
DX
3289 return (void*) (dtv[index + 1] + offset);
3290}
3291
9e2ee207 3292#if defined(RTLD_STATIC_TLS_VARIANT_II)
55b88cae
DX
3293
3294/*
bc633d63
MD
3295 * Allocate the static TLS area. Return a pointer to the TCB. The
3296 * static area is based on negative offsets relative to the tcb.
a1eee96a
MD
3297 *
3298 * The TCB contains an errno pointer for the system call layer, but because
3299 * we are the RTLD we really have no idea how the caller was compiled so
3300 * the information has to be passed in. errno can either be:
3301 *
3302 * type 0 errno is a simple non-TLS global pointer.
3303 * (special case for e.g. libc_rtld)
3304 * type 1 errno accessed by GOT entry (dynamically linked programs)
3305 * type 2 errno accessed by %gs:OFFSET (statically linked programs)
55b88cae 3306 */
bc633d63 3307struct tls_tcb *
a1eee96a 3308allocate_tls(Obj_Entry *objs)
55b88cae
DX
3309{
3310 Obj_Entry *obj;
bc633d63 3311 size_t data_size;
bc633d63
MD
3312 size_t dtv_size;
3313 struct tls_tcb *tcb;
a1eee96a 3314 Elf_Addr *dtv;
bc633d63 3315 Elf_Addr addr;
55b88cae 3316
bc633d63
MD
3317 /*
3318 * Allocate the new TCB. static TLS storage is placed just before the
3319 * TCB to support the %gs:OFFSET (negative offset) model.
3320 */
bc633d63
MD
3321 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
3322 ~RTLD_STATIC_TLS_ALIGN_MASK;
f20fd431 3323 tcb = malloc(data_size + sizeof(*tcb));
bc633d63 3324 tcb = (void *)((char *)tcb + data_size); /* actual tcb location */
55b88cae 3325
bc633d63
MD
3326 dtv_size = (tls_max_index + 2) * sizeof(Elf_Addr);
3327 dtv = malloc(dtv_size);
3328 bzero(dtv, dtv_size);
55b88cae 3329
9e2ee207
JS
3330#ifdef RTLD_TCB_HAS_SELF_POINTER
3331 tcb->tcb_self = tcb;
3332#endif
3333 tcb->tcb_dtv = dtv;
3334 tcb->tcb_pthread = NULL;
55b88cae
DX
3335
3336 dtv[0] = tls_dtv_generation;
3337 dtv[1] = tls_max_index;
3338
a1eee96a
MD
3339 for (obj = objs; obj; obj = obj->next) {
3340 if (obj->tlsoffset) {
3341 addr = (Elf_Addr)tcb - obj->tlsoffset;
3342 memset((void *)(addr + obj->tlsinitsize),
3343 0, obj->tlssize - obj->tlsinitsize);
3344 if (obj->tlsinit)
3345 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
3346 dtv[obj->tlsindex + 1] = addr;
55b88cae
DX
3347 }
3348 }
bc633d63 3349 return(tcb);
55b88cae
DX
3350}
3351
3352void
f20fd431 3353free_tls(struct tls_tcb *tcb)
bc633d63
MD
3354{
3355 Elf_Addr *dtv;
3356 int dtv_size, i;
3357 Elf_Addr tls_start, tls_end;
3358 size_t data_size;
3359
3360 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
3361 ~RTLD_STATIC_TLS_ALIGN_MASK;
fcf53d9b 3362
9e2ee207 3363 dtv = tcb->tcb_dtv;
bc633d63
MD
3364 dtv_size = dtv[1];
3365 tls_end = (Elf_Addr)tcb;
3366 tls_start = (Elf_Addr)tcb - data_size;
3367 for (i = 0; i < dtv_size; i++) {
eecd52b2 3368 if (dtv[i+2] != 0 && (dtv[i+2] < tls_start || dtv[i+2] > tls_end)) {
bc633d63 3369 free((void *)dtv[i+2]);
55b88cae
DX
3370 }
3371 }
fcf53d9b
JM
3372
3373 free((void*) tls_start);
55b88cae
DX
3374}
3375
9e2ee207
JS
3376#else
3377#error "Unsupported TLS layout"
55b88cae
DX
3378#endif
3379
3380/*
3381 * Allocate TLS block for module with given index.
3382 */
3383void *
3384allocate_module_tls(int index)
3385{
3386 Obj_Entry* obj;
3387 char* p;
3388
3389 for (obj = obj_list; obj; obj = obj->next) {
3390 if (obj->tlsindex == index)
3391 break;
3392 }
3393 if (!obj) {
3394 _rtld_error("Can't find module with TLS index %d", index);
3395 die();
3396 }
3397
3398 p = malloc(obj->tlssize);
fcf53d9b
JM
3399 if (p == NULL) {
3400 _rtld_error("Cannot allocate TLS block for index %d", index);
3401 die();
3402 }
55b88cae
DX
3403 memcpy(p, obj->tlsinit, obj->tlsinitsize);
3404 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
3405
3406 return p;
3407}
3408
3409bool
3410allocate_tls_offset(Obj_Entry *obj)
3411{
3412 size_t off;
3413
3414 if (obj->tls_done)
3415 return true;
3416
3417 if (obj->tlssize == 0) {
3418 obj->tls_done = true;
3419 return true;
3420 }
3421
3422 if (obj->tlsindex == 1)
3423 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
3424 else
3425 off = calculate_tls_offset(tls_last_offset, tls_last_size,
3426 obj->tlssize, obj->tlsalign);
3427
3428 /*
3429 * If we have already fixed the size of the static TLS block, we
3430 * must stay within that size. When allocating the static TLS, we
3431 * leave a small amount of space spare to be used for dynamically
3432 * loading modules which use static TLS.
3433 */
3434 if (tls_static_space) {
3435 if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
3436 return false;
3437 }
3438
3439 tls_last_offset = obj->tlsoffset = off;
3440 tls_last_size = obj->tlssize;
3441 obj->tls_done = true;
3442
3443 return true;
3444}
3445
3446void
3447free_tls_offset(Obj_Entry *obj)
3448{
9e2ee207 3449#ifdef RTLD_STATIC_TLS_VARIANT_II
55b88cae
DX
3450 /*
3451 * If we were the last thing to allocate out of the static TLS
3452 * block, we give our space back to the 'allocator'. This is a
3453 * simplistic workaround to allow libGL.so.1 to be loaded and
3454 * unloaded multiple times. We only handle the Variant II
3455 * mechanism for now - this really needs a proper allocator.
3456 */
3457 if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
3458 == calculate_tls_end(tls_last_offset, tls_last_size)) {
3459 tls_last_offset -= obj->tlssize;
3460 tls_last_size = 0;
3461 }
3462#endif
3463}
3464
bc633d63 3465struct tls_tcb *
a1eee96a 3466_rtld_allocate_tls(void)
55b88cae 3467{
bc633d63 3468 struct tls_tcb *new_tcb;
fcf53d9b 3469 RtldLockState lockstate;
55b88cae 3470
fcf53d9b 3471 wlock_acquire(rtld_bind_lock, &lockstate);
a1eee96a 3472 new_tcb = allocate_tls(obj_list);
fcf53d9b 3473 lock_release(rtld_bind_lock, &lockstate);
bc633d63 3474 return (new_tcb);
55b88cae
DX
3475}
3476
3477void
f20fd431 3478_rtld_free_tls(struct tls_tcb *tcb)
55b88cae 3479{
fcf53d9b
JM
3480 RtldLockState lockstate;
3481
3482 wlock_acquire(rtld_bind_lock, &lockstate);
f20fd431 3483 free_tls(tcb);
fcf53d9b
JM
3484 lock_release(rtld_bind_lock, &lockstate);
3485}
3486
3487static void
3488object_add_name(Obj_Entry *obj, const char *name)
3489{
3490 Name_Entry *entry;
3491 size_t len;
3492
3493 len = strlen(name);
3494 entry = malloc(sizeof(Name_Entry) + len);
3495
3496 if (entry != NULL) {
3497 strcpy(entry->name, name);
3498 STAILQ_INSERT_TAIL(&obj->names, entry, link);
3499 }
3500}
3501
3502static int
3503object_match_name(const Obj_Entry *obj, const char *name)
3504{
3505 Name_Entry *entry;
3506
3507 STAILQ_FOREACH(entry, &obj->names, link) {
3508 if (strcmp(name, entry->name) == 0)
3509 return (1);
3510 }
3511 return (0);
3512}
3513
3514static Obj_Entry *
3515locate_dependency(const Obj_Entry *obj, const char *name)
3516{
3517 const Objlist_Entry *entry;
3518 const Needed_Entry *needed;
3519
3520 STAILQ_FOREACH(entry, &list_main, link) {
3521 if (object_match_name(entry->obj, name))
3522 return entry->obj;
3523 }
3524
3525 for (needed = obj->needed; needed != NULL; needed = needed->next) {
3526 if (strcmp(obj->strtab + needed->name, name) == 0 ||
3527 (needed->obj != NULL && object_match_name(needed->obj, name))) {
3528 /*
3529 * If there is DT_NEEDED for the name we are looking for,
3530 * we are all set. Note that object might not be found if
3531 * dependency was not loaded yet, so the function can
3532 * return NULL here. This is expected and handled
3533 * properly by the caller.
3534 */
3535 return (needed->obj);
3536 }
3537 }
3538 _rtld_error("%s: Unexpected inconsistency: dependency %s not found",
3539 obj->path, name);
3540 die();
3541}
3542
3543static int
3544check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
3545 const Elf_Vernaux *vna)
3546{
3547 const Elf_Verdef *vd;
3548 const char *vername;
3549
3550 vername = refobj->strtab + vna->vna_name;
3551 vd = depobj->verdef;
3552 if (vd == NULL) {
3553 _rtld_error("%s: version %s required by %s not defined",
3554 depobj->path, vername, refobj->path);
3555 return (-1);
3556 }
3557 for (;;) {
3558 if (vd->vd_version != VER_DEF_CURRENT) {
3559 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
3560 depobj->path, vd->vd_version);
3561 return (-1);
3562 }
3563 if (vna->vna_hash == vd->vd_hash) {
3564 const Elf_Verdaux *aux = (const Elf_Verdaux *)
3565 ((char *)vd + vd->vd_aux);
3566 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
3567 return (0);
3568 }
3569 if (vd->vd_next == 0)
3570 break;
3571 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
3572 }
3573 if (vna->vna_flags & VER_FLG_WEAK)
3574 return (0);
3575 _rtld_error("%s: version %s required by %s not found",
3576 depobj->path, vername, refobj->path);
3577 return (-1);
55b88cae 3578}
bc633d63 3579
fcf53d9b
JM
3580static int
3581rtld_verify_object_versions(Obj_Entry *obj)
3582{
3583 const Elf_Verneed *vn;
3584 const Elf_Verdef *vd;
3585 const Elf_Verdaux *vda;
3586 const Elf_Vernaux *vna;
3587 const Obj_Entry *depobj;
3588 int maxvernum, vernum;
3589
3590 maxvernum = 0;
3591 /*
3592 * Walk over defined and required version records and figure out
3593 * max index used by any of them. Do very basic sanity checking
3594 * while there.
3595 */
3596 vn = obj->verneed;
3597 while (vn != NULL) {
3598 if (vn->vn_version != VER_NEED_CURRENT) {
3599 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
3600 obj->path, vn->vn_version);
3601 return (-1);
3602 }
3603 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
3604 for (;;) {
3605 vernum = VER_NEED_IDX(vna->vna_other);
3606 if (vernum > maxvernum)
3607 maxvernum = vernum;
3608 if (vna->vna_next == 0)
3609 break;
3610 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
3611 }
3612 if (vn->vn_next == 0)
3613 break;
3614 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
3615 }
3616
3617 vd = obj->verdef;
3618 while (vd != NULL) {
3619 if (vd->vd_version != VER_DEF_CURRENT) {
3620 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
3621 obj->path, vd->vd_version);
3622 return (-1);
3623 }
3624 vernum = VER_DEF_IDX(vd->vd_ndx);
3625 if (vernum > maxvernum)
3626 maxvernum = vernum;
3627 if (vd->vd_next == 0)
3628 break;
3629 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
3630 }
3631
3632 if (maxvernum == 0)
3633 return (0);
3634
3635 /*
3636 * Store version information in array indexable by version index.
3637 * Verify that object version requirements are satisfied along the
3638 * way.
3639 */
3640 obj->vernum = maxvernum + 1;
3641 obj->vertab = calloc(obj->vernum, sizeof(Ver_Entry));
3642
3643 vd = obj->verdef;
3644 while (vd != NULL) {
3645 if ((vd->vd_flags & VER_FLG_BASE) == 0) {
3646 vernum = VER_DEF_IDX(vd->vd_ndx);
3647 assert(vernum <= maxvernum);
3648 vda = (const Elf_Verdaux *)((char *)vd + vd->vd_aux);
3649 obj->vertab[vernum].hash = vd->vd_hash;
3650 obj->vertab[vernum].name = obj->strtab + vda->vda_name;
3651 obj->vertab[vernum].file = NULL;
3652 obj->vertab[vernum].flags = 0;
3653 }
3654 if (vd->vd_next == 0)
3655 break;
3656 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
3657 }
3658
3659 vn = obj->verneed;
3660 while (vn != NULL) {
3661 depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
3662 if (depobj == NULL)
3663 return (-1);
3664 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
3665 for (;;) {
3666 if (check_object_provided_version(obj, depobj, vna))
3667 return (-1);
3668 vernum = VER_NEED_IDX(vna->vna_other);
3669 assert(vernum <= maxvernum);
3670 obj->vertab[vernum].hash = vna->vna_hash;
3671 obj->vertab[vernum].name = obj->strtab + vna->vna_name;
3672 obj->vertab[vernum].file = obj->strtab + vn->vn_file;
3673 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ?
3674 VER_INFO_HIDDEN : 0;
3675 if (vna->vna_next == 0)
3676 break;
3677 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
3678 }
3679 if (vn->vn_next == 0)
3680 break;
3681 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);
3682 }
3683 return 0;
3684}
3685
3686static int
3687rtld_verify_versions(const Objlist *objlist)
3688{
3689 Objlist_Entry *entry;
3690 int rc;
3691
3692 rc = 0;
3693 STAILQ_FOREACH(entry, objlist, link) {
3694 /*
3695 * Skip dummy objects or objects that have their version requirements
3696 * already checked.
3697 */
3698 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL)
3699 continue;
3700 if (rtld_verify_object_versions(entry->obj) == -1) {
3701 rc = -1;
3702 if (ld_tracing == NULL)
3703 break;
3704 }
3705 }
3706 if (rc == 0 || ld_tracing != NULL)
3707 rc = rtld_verify_object_versions(&obj_rtld);
3708 return rc;
3709}
3710
3711const Ver_Entry *
3712fetch_ventry(const Obj_Entry *obj, unsigned long symnum)
3713{
3714 Elf_Versym vernum;
3715
3716 if (obj->ve