rtld: Remove useless arch Makefiles
[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 *
f4f4bfd5 27 * $FreeBSD$
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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>
b566341b 44#include <sys/sysctl.h>
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45#include <sys/uio.h>
46#include <sys/utsname.h>
47#include <sys/ktrace.h>
8ca15ec8 48#include <sys/resident.h>
bc633d63 49#include <sys/tls.h>
984263bc 50
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51#include <machine/tls.h>
52
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53#include <dlfcn.h>
54#include <err.h>
55#include <errno.h>
56#include <fcntl.h>
57#include <stdarg.h>
58#include <stdio.h>
59#include <stdlib.h>
60#include <string.h>
61#include <unistd.h>
62
63#include "debug.h"
64#include "rtld.h"
fcf53d9b 65#include "libmap.h"
abfcd5b1 66#include "rtld_printf.h"
984263bc 67
a1eee96a 68#define PATH_RTLD "/usr/libexec/ld-elf.so.2"
8ca15ec8 69#define LD_ARY_CACHE 16
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70
71/* Types. */
72typedef void (*func_ptr_type)();
73typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
74
75/*
76 * This structure provides a reentrant way to keep a list of objects and
77 * check which ones have already been processed in some way.
78 */
79typedef struct Struct_DoneList {
80 const Obj_Entry **objs; /* Array of object pointers */
81 unsigned int num_alloc; /* Allocated size of the array */
82 unsigned int num_used; /* Number of array slots used */
83} DoneList;
84
85/*
86 * Function declarations.
87 */
8ca15ec8 88static const char *_getenv_ld(const char *id);
fcf53d9b 89static void die(void) __dead2;
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90static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
91 const Elf_Dyn **);
92static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *);
fcf53d9b 93static void digest_dynamic(Obj_Entry *, int);
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94static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
95static Obj_Entry *dlcheck(void *);
fcf53d9b 96static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
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97static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
98static bool donelist_check(DoneList *, const Obj_Entry *);
99static void errmsg_restore(char *);
100static char *errmsg_save(void);
101static void *fill_search_info(const char *, size_t, void *);
102static char *find_library(const char *, const Obj_Entry *);
103static const char *gethints(void);
104static void init_dag(Obj_Entry *);
fcf53d9b 105static void init_dag1(Obj_Entry *, Obj_Entry *, DoneList *);
b566341b 106static void init_rtld(caddr_t, Elf_Auxinfo **);
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107static void initlist_add_neededs(Needed_Entry *, Objlist *);
108static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
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109static bool is_exported(const Elf_Sym *);
110static void linkmap_add(Obj_Entry *);
111static void linkmap_delete(Obj_Entry *);
fcf53d9b 112static int load_needed_objects(Obj_Entry *, int);
984263bc 113static int load_preload_objects(void);
fcf53d9b 114static Obj_Entry *load_object(const char *, const Obj_Entry *, int);
984263bc 115static Obj_Entry *obj_from_addr(const void *);
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116static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
117static void objlist_call_init(Objlist *, RtldLockState *);
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118static void objlist_clear(Objlist *);
119static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
120static void objlist_init(Objlist *);
121static void objlist_push_head(Objlist *, Obj_Entry *);
122static void objlist_push_tail(Objlist *, Obj_Entry *);
123static void objlist_remove(Objlist *, Obj_Entry *);
984263bc 124static void *path_enumerate(const char *, path_enum_proc, void *);
c3098c28 125static int relocate_objects(Obj_Entry *, bool, Obj_Entry *);
984263bc 126static int rtld_dirname(const char *, char *);
fcf53d9b 127static int rtld_dirname_abs(const char *, char *);
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128static void rtld_exit(void);
129static char *search_library_path(const char *, const char *);
fcf53d9b 130static const void **get_program_var_addr(const char *);
984263bc 131static void set_program_var(const char *, const void *);
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132static const Elf_Sym *symlook_default(const char *, unsigned long,
133 const Obj_Entry *, const Obj_Entry **, const Ver_Entry *, int);
134static const Elf_Sym *symlook_list(const char *, unsigned long, const Objlist *,
135 const Obj_Entry **, const Ver_Entry *, int, DoneList *);
cebaf0af 136static const Elf_Sym *symlook_needed(const char *, unsigned long,
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137 const Needed_Entry *, const Obj_Entry **, const Ver_Entry *,
138 int, DoneList *);
139static void trace_loaded_objects(Obj_Entry *);
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140static void unlink_object(Obj_Entry *);
141static void unload_object(Obj_Entry *);
142static void unref_dag(Obj_Entry *);
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143static void ref_dag(Obj_Entry *);
144static int origin_subst_one(char **, const char *, const char *,
145 const char *, char *);
146static char *origin_subst(const char *, const char *);
147static int rtld_verify_versions(const Objlist *);
148static int rtld_verify_object_versions(Obj_Entry *);
149static void object_add_name(Obj_Entry *, const char *);
150static int object_match_name(const Obj_Entry *, const char *);
151static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
152static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
153 struct dl_phdr_info *phdr_info);
154
8301820e 155void r_debug_state(struct r_debug *, struct link_map *) __noinline;
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156
157/*
158 * Data declarations.
159 */
160static char *error_message; /* Message for dlerror(), or NULL */
161struct r_debug r_debug; /* for GDB; */
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162static bool libmap_disable; /* Disable libmap */
163static char *libmap_override; /* Maps to use in addition to libmap.conf */
984263bc 164static bool trust; /* False for setuid and setgid programs */
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165static bool dangerous_ld_env; /* True if environment variables have been
166 used to affect the libraries loaded */
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167static const char *ld_bind_now; /* Environment variable for immediate binding */
168static const char *ld_debug; /* Environment variable for debugging */
169static const char *ld_library_path; /* Environment variable for search path */
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170static char *ld_preload; /* Environment variable for libraries to
171 load first */
fcf53d9b 172static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */
b566341b 173static const char *ld_tracing; /* Called from ldd to print libs */
fcf53d9b 174static const char *ld_utrace; /* Use utrace() to log events. */
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175static int (*rtld_functrace)( /* Optional function call tracing hook */
176 const char *caller_obj,
177 const char *callee_obj,
178 const char *callee_func,
179 void *stack);
38e4b3b6 180static Obj_Entry *rtld_functrace_obj; /* Object thereof */
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181static Obj_Entry *obj_list; /* Head of linked list of shared objects */
182static Obj_Entry **obj_tail; /* Link field of last object in list */
8ca15ec8 183static Obj_Entry **preload_tail;
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184static Obj_Entry *obj_main; /* The main program shared object */
185static Obj_Entry obj_rtld; /* The dynamic linker shared object */
186static unsigned int obj_count; /* Number of objects in obj_list */
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187static unsigned int obj_loads; /* Number of objects in obj_list */
188
33a8b578 189static int ld_resident; /* Non-zero if resident */
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190static const char *ld_ary[LD_ARY_CACHE];
191static int ld_index;
a1eee96a 192static Objlist initlist;
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193
194static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
195 STAILQ_HEAD_INITIALIZER(list_global);
196static Objlist list_main = /* Objects loaded at program startup */
197 STAILQ_HEAD_INITIALIZER(list_main);
198static Objlist list_fini = /* Objects needing fini() calls */
199 STAILQ_HEAD_INITIALIZER(list_fini);
200
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201static Elf_Sym sym_zero; /* For resolving undefined weak refs. */
202
203#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
204
205extern Elf_Dyn _DYNAMIC;
206#pragma weak _DYNAMIC
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207#ifndef RTLD_IS_DYNAMIC
208#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL)
209#endif
984263bc 210
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211#ifdef ENABLE_OSRELDATE
212int osreldate;
213#endif
214
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215/*
216 * These are the functions the dynamic linker exports to application
217 * programs. They are the only symbols the dynamic linker is willing
218 * to export from itself.
219 */
220static func_ptr_type exports[] = {
221 (func_ptr_type) &_rtld_error,
222 (func_ptr_type) &dlclose,
223 (func_ptr_type) &dlerror,
224 (func_ptr_type) &dlopen,
fcf53d9b 225 (func_ptr_type) &dlfunc,
984263bc 226 (func_ptr_type) &dlsym,
fcf53d9b 227 (func_ptr_type) &dlvsym,
984263bc 228 (func_ptr_type) &dladdr,
984263bc 229 (func_ptr_type) &dlinfo,
fcf53d9b 230 (func_ptr_type) &dl_iterate_phdr,
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231#ifdef __i386__
232 (func_ptr_type) &___tls_get_addr,
233#endif
234 (func_ptr_type) &__tls_get_addr,
a1eee96a 235 (func_ptr_type) &__tls_get_addr_tcb,
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236 (func_ptr_type) &_rtld_allocate_tls,
237 (func_ptr_type) &_rtld_free_tls,
a1eee96a 238 (func_ptr_type) &_rtld_call_init,
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239 (func_ptr_type) &_rtld_thread_init,
240 (func_ptr_type) &_rtld_addr_phdr,
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241 NULL
242};
243
244/*
245 * Global declarations normally provided by crt1. The dynamic linker is
246 * not built with crt1, so we have to provide them ourselves.
247 */
248char *__progname;
249char **environ;
250
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251/*
252 * Globals to control TLS allocation.
253 */
254size_t tls_last_offset; /* Static TLS offset of last module */
255size_t tls_last_size; /* Static TLS size of last module */
256size_t tls_static_space; /* Static TLS space allocated */
257int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
258int tls_max_index = 1; /* Largest module index allocated */
259
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260/*
261 * Fill in a DoneList with an allocation large enough to hold all of
262 * the currently-loaded objects. Keep this as a macro since it calls
263 * alloca and we want that to occur within the scope of the caller.
264 */
265#define donelist_init(dlp) \
266 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
267 assert((dlp)->objs != NULL), \
268 (dlp)->num_alloc = obj_count, \
269 (dlp)->num_used = 0)
270
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271#define UTRACE_DLOPEN_START 1
272#define UTRACE_DLOPEN_STOP 2
273#define UTRACE_DLCLOSE_START 3
274#define UTRACE_DLCLOSE_STOP 4
275#define UTRACE_LOAD_OBJECT 5
276#define UTRACE_UNLOAD_OBJECT 6
277#define UTRACE_ADD_RUNDEP 7
278#define UTRACE_PRELOAD_FINISHED 8
279#define UTRACE_INIT_CALL 9
280#define UTRACE_FINI_CALL 10
281
282struct utrace_rtld {
283 char sig[4]; /* 'RTLD' */
284 int event;
285 void *handle;
286 void *mapbase; /* Used for 'parent' and 'init/fini' */
287 size_t mapsize;
288 int refcnt; /* Used for 'mode' */
289 char name[MAXPATHLEN];
290};
984263bc 291
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292#define LD_UTRACE(e, h, mb, ms, r, n) do { \
293 if (ld_utrace != NULL) \
294 ld_utrace_log(e, h, mb, ms, r, n); \
295} while (0)
984263bc 296
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297static void
298ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
299 int refcnt, const char *name)
300{
301 struct utrace_rtld ut;
302
303 ut.sig[0] = 'R';
304 ut.sig[1] = 'T';
305 ut.sig[2] = 'L';
306 ut.sig[3] = 'D';
307 ut.event = event;
308 ut.handle = handle;
309 ut.mapbase = mapbase;
310 ut.mapsize = mapsize;
311 ut.refcnt = refcnt;
312 bzero(ut.name, sizeof(ut.name));
313 if (name)
314 strlcpy(ut.name, name, sizeof(ut.name));
315 utrace(&ut, sizeof(ut));
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316}
317
318/*
319 * Main entry point for dynamic linking. The first argument is the
320 * stack pointer. The stack is expected to be laid out as described
321 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
322 * Specifically, the stack pointer points to a word containing
323 * ARGC. Following that in the stack is a null-terminated sequence
324 * of pointers to argument strings. Then comes a null-terminated
325 * sequence of pointers to environment strings. Finally, there is a
326 * sequence of "auxiliary vector" entries.
327 *
328 * The second argument points to a place to store the dynamic linker's
329 * exit procedure pointer and the third to a place to store the main
330 * program's object.
331 *
332 * The return value is the main program's entry point.
333 */
334func_ptr_type
335_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
336{
337 Elf_Auxinfo *aux_info[AT_COUNT];
338 int i;
339 int argc;
340 char **argv;
341 char **env;
342 Elf_Auxinfo *aux;
343 Elf_Auxinfo *auxp;
344 const char *argv0;
55b88cae 345 Objlist_Entry *entry;
984263bc 346 Obj_Entry *obj;
984263bc 347
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348 /* marino: DO NOT MOVE THESE VARIABLES TO _rtld
349 Obj_Entry **preload_tail;
350 Objlist initlist;
351 from global to here. It will break the DRAWF2 unwind scheme.
352 The system compilers were unaffected, but not gcc 4.6
353 */
354
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355 /*
356 * On entry, the dynamic linker itself has not been relocated yet.
357 * Be very careful not to reference any global data until after
358 * init_rtld has returned. It is OK to reference file-scope statics
359 * and string constants, and to call static and global functions.
360 */
361
362 /* Find the auxiliary vector on the stack. */
363 argc = *sp++;
364 argv = (char **) sp;
365 sp += argc + 1; /* Skip over arguments and NULL terminator */
366 env = (char **) sp;
984263bc 367
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368 /*
369 * If we aren't already resident we have to dig out some more info.
370 * Note that auxinfo does not exist when we are resident.
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371 *
372 * I'm not sure about the ld_resident check. It seems to read zero
373 * prior to relocation, which is what we want. When running from a
374 * resident copy everything will be relocated so we are definitely
375 * good there.
33a8b578 376 */
5347affc 377 if (ld_resident == 0) {
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378 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
379 ;
380 aux = (Elf_Auxinfo *) sp;
381
382 /* Digest the auxiliary vector. */
383 for (i = 0; i < AT_COUNT; i++)
384 aux_info[i] = NULL;
385 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
386 if (auxp->a_type < AT_COUNT)
387 aux_info[auxp->a_type] = auxp;
388 }
389
390 /* Initialize and relocate ourselves. */
391 assert(aux_info[AT_BASE] != NULL);
b566341b 392 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
33a8b578 393 }
984263bc 394
5347affc 395 ld_index = 0; /* don't use old env cache in case we are resident */
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396 __progname = obj_rtld.path;
397 argv0 = argv[0] != NULL ? argv[0] : "(null)";
398 environ = env;
399
fcf53d9b 400 trust = !issetugid();
984263bc 401
8ca15ec8 402 ld_bind_now = _getenv_ld("LD_BIND_NOW");
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403 /*
404 * If the process is tainted, then we un-set the dangerous environment
405 * variables. The process will be marked as tainted until setuid(2)
406 * is called. If any child process calls setuid(2) we do not want any
407 * future processes to honor the potentially un-safe variables.
408 */
409 if (!trust) {
410 if ( unsetenv("LD_DEBUG")
411 || unsetenv("LD_PRELOAD")
412 || unsetenv("LD_LIBRARY_PATH")
413 || unsetenv("LD_ELF_HINTS_PATH")
414 || unsetenv("LD_LIBMAP")
415 || unsetenv("LD_LIBMAP_DISABLE")
416 ) {
417 _rtld_error("environment corrupt; aborting");
418 die();
419 }
984263bc 420 }
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421 ld_debug = _getenv_ld("LD_DEBUG");
422 ld_library_path = _getenv_ld("LD_LIBRARY_PATH");
423 ld_preload = (char *)_getenv_ld("LD_PRELOAD");
424 ld_elf_hints_path = _getenv_ld("LD_ELF_HINTS_PATH");
425 libmap_override = (char *)_getenv_ld("LD_LIBMAP");
426 libmap_disable = _getenv_ld("LD_LIBMAP_DISABLE") != NULL;
427 dangerous_ld_env = (ld_library_path != NULL)
428 || (ld_preload != NULL)
429 || (ld_elf_hints_path != NULL)
430 || (libmap_override != NULL)
431 || libmap_disable
432 ;
8ca15ec8 433 ld_tracing = _getenv_ld("LD_TRACE_LOADED_OBJECTS");
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434 ld_utrace = _getenv_ld("LD_UTRACE");
435
436 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
437 ld_elf_hints_path = _PATH_ELF_HINTS;
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438
439 if (ld_debug != NULL && *ld_debug != '\0')
440 debug = 1;
441 dbg("%s is initialized, base address = %p", __progname,
442 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
443 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
444 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
445
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446 dbg("initializing thread locks");
447 lockdflt_init();
448
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449 /*
450 * If we are resident we can skip work that we have already done.
451 * Note that the stack is reset and there is no Elf_Auxinfo
452 * when running from a resident image, and the static globals setup
453 * between here and resident_skip will have already been setup.
454 */
8ca15ec8 455 if (ld_resident)
33a8b578 456 goto resident_skip1;
33a8b578 457
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458 /*
459 * Load the main program, or process its program header if it is
460 * already loaded.
461 */
462 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
463 int fd = aux_info[AT_EXECFD]->a_un.a_val;
464 dbg("loading main program");
465 obj_main = map_object(fd, argv0, NULL);
466 close(fd);
467 if (obj_main == NULL)
468 die();
469 } else { /* Main program already loaded. */
470 const Elf_Phdr *phdr;
471 int phnum;
472 caddr_t entry;
473
474 dbg("processing main program's program header");
475 assert(aux_info[AT_PHDR] != NULL);
476 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
477 assert(aux_info[AT_PHNUM] != NULL);
478 phnum = aux_info[AT_PHNUM]->a_un.a_val;
479 assert(aux_info[AT_PHENT] != NULL);
480 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
481 assert(aux_info[AT_ENTRY] != NULL);
482 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
483 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
484 die();
485 }
486
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487 char buf[MAXPATHLEN];
488 if (aux_info[AT_EXECPATH] != 0) {
489 char *kexecpath;
490
491 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
492 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
493 if (kexecpath[0] == '/')
494 obj_main->path = kexecpath;
495 else if (getcwd(buf, sizeof(buf)) == NULL ||
496 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
497 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
498 obj_main->path = xstrdup(argv0);
499 else
500 obj_main->path = xstrdup(buf);
501 } else {
502 char resolved[MAXPATHLEN];
503 dbg("No AT_EXECPATH");
504 if (argv0[0] == '/') {
505 if (realpath(argv0, resolved) != NULL)
506 obj_main->path = xstrdup(resolved);
507 else
508 obj_main->path = xstrdup(argv0);
509 } else {
510 if (getcwd(buf, sizeof(buf)) != NULL
511 && strlcat(buf, "/", sizeof(buf)) < sizeof(buf)
512 && strlcat(buf, argv0, sizeof (buf)) < sizeof(buf)
513 && access(buf, R_OK) == 0
514 && realpath(buf, resolved) != NULL)
515 obj_main->path = xstrdup(resolved);
516 else
517 obj_main->path = xstrdup(argv0);
518 }
519 }
520 dbg("obj_main path %s", obj_main->path);
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521 obj_main->mainprog = true;
522
523 /*
524 * Get the actual dynamic linker pathname from the executable if
525 * possible. (It should always be possible.) That ensures that
526 * gdb will find the right dynamic linker even if a non-standard
527 * one is being used.
528 */
529 if (obj_main->interp != NULL &&
530 strcmp(obj_main->interp, obj_rtld.path) != 0) {
531 free(obj_rtld.path);
532 obj_rtld.path = xstrdup(obj_main->interp);
b7b05c9f 533 __progname = obj_rtld.path;
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534 }
535
c3098c28 536 digest_dynamic(obj_main, 0);
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537
538 linkmap_add(obj_main);
539 linkmap_add(&obj_rtld);
540
541 /* Link the main program into the list of objects. */
542 *obj_tail = obj_main;
543 obj_tail = &obj_main->next;
544 obj_count++;
fcf53d9b 545 obj_loads++;
984263bc 546 /* Make sure we don't call the main program's init and fini functions. */
fcf53d9b 547 obj_main->init = obj_main->fini = (Elf_Addr)NULL;
984263bc
MD
548
549 /* Initialize a fake symbol for resolving undefined weak references. */
550 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
fcf53d9b
JM
551 sym_zero.st_shndx = SHN_UNDEF;
552 sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
553
554 if (!libmap_disable)
555 libmap_disable = (bool)lm_init(libmap_override);
984263bc
MD
556
557 dbg("loading LD_PRELOAD libraries");
558 if (load_preload_objects() == -1)
559 die();
560 preload_tail = obj_tail;
561
562 dbg("loading needed objects");
fcf53d9b 563 if (load_needed_objects(obj_main, 0) == -1)
984263bc
MD
564 die();
565
566 /* Make a list of all objects loaded at startup. */
fcf53d9b 567 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc 568 objlist_push_tail(&list_main, obj);
fcf53d9b
JM
569 obj->refcount++;
570 }
571
572 dbg("checking for required versions");
573 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
574 die();
984263bc 575
33a8b578
MD
576resident_skip1:
577
984263bc
MD
578 if (ld_tracing) { /* We're done */
579 trace_loaded_objects(obj_main);
580 exit(0);
581 }
582
33a8b578
MD
583 if (ld_resident) /* XXX clean this up! */
584 goto resident_skip2;
585
fcf53d9b 586 if (_getenv_ld("LD_DUMP_REL_PRE") != NULL) {
4a8d9350
JS
587 dump_relocations(obj_main);
588 exit (0);
589 }
590
55b88cae
DX
591 /* setup TLS for main thread */
592 dbg("initializing initial thread local storage");
593 STAILQ_FOREACH(entry, &list_main, link) {
594 /*
595 * Allocate all the initial objects out of the static TLS
596 * block even if they didn't ask for it.
597 */
598 allocate_tls_offset(entry->obj);
599 }
a1eee96a
MD
600
601 tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA;
602
603 /*
604 * Do not try to allocate the TLS here, let libc do it itself.
605 * (crt1 for the program will call _init_tls())
606 */
55b88cae 607
6192271e 608 if (relocate_objects(obj_main,
c3098c28 609 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld) == -1)
6192271e 610 die();
984263bc 611
6192271e
MD
612 dbg("doing copy relocations");
613 if (do_copy_relocations(obj_main) == -1)
614 die();
1c76efe5 615
33a8b578
MD
616resident_skip2:
617
8ca15ec8 618 if (_getenv_ld("LD_RESIDENT_UNREGISTER_NOW")) {
33a8b578
MD
619 if (exec_sys_unregister(-1) < 0) {
620 dbg("exec_sys_unregister failed %d\n", errno);
621 exit(errno);
622 }
623 dbg("exec_sys_unregister success\n");
624 exit(0);
625 }
984263bc 626
fcf53d9b 627 if (_getenv_ld("LD_DUMP_REL_POST") != NULL) {
4a8d9350
JS
628 dump_relocations(obj_main);
629 exit (0);
630 }
631
984263bc
MD
632 dbg("initializing key program variables");
633 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
634 set_program_var("environ", env);
b566341b 635 set_program_var("__elf_aux_vector", aux);
984263bc 636
8ca15ec8
MD
637 if (_getenv_ld("LD_RESIDENT_REGISTER_NOW")) {
638 extern void resident_start(void);
639 ld_resident = 1;
640 if (exec_sys_register(resident_start) < 0) {
641 dbg("exec_sys_register failed %d\n", errno);
642 exit(errno);
643 }
644 dbg("exec_sys_register success\n");
645 exit(0);
646 }
647
984263bc
MD
648 /* Make a list of init functions to call. */
649 objlist_init(&initlist);
650 initlist_add_objects(obj_list, preload_tail, &initlist);
651
652 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
653
a1eee96a
MD
654 /*
655 * Do NOT call the initlist here, give libc a chance to set up
656 * the initial TLS segment. crt1 will then call _rtld_call_init().
657 */
8ca15ec8 658
984263bc
MD
659 dbg("transferring control to program entry point = %p", obj_main->entry);
660
661 /* Return the exit procedure and the program entry point. */
662 *exit_proc = rtld_exit;
663 *objp = obj_main;
664 return (func_ptr_type) obj_main->entry;
665}
666
a1eee96a
MD
667/*
668 * Call the initialization list for dynamically loaded libraries.
669 * (called from crt1.c).
670 */
671void
672_rtld_call_init(void)
673{
fcf53d9b
JM
674 RtldLockState lockstate;
675
676 wlock_acquire(rtld_bind_lock, &lockstate);
677 objlist_call_init(&initlist, &lockstate);
a1eee96a 678 objlist_clear(&initlist);
fcf53d9b 679 lock_release(rtld_bind_lock, &lockstate);
a1eee96a
MD
680}
681
984263bc 682Elf_Addr
4648abf3 683_rtld_bind(Obj_Entry *obj, Elf_Size reloff, void *stack)
984263bc
MD
684{
685 const Elf_Rel *rel;
686 const Elf_Sym *def;
687 const Obj_Entry *defobj;
688 Elf_Addr *where;
689 Elf_Addr target;
fcf53d9b 690 RtldLockState lockstate;
38e4b3b6 691 int do_reloc = 1;
984263bc 692
fcf53d9b
JM
693 rlock_acquire(rtld_bind_lock, &lockstate);
694 if (sigsetjmp(lockstate.env, 0) != 0)
695 lock_upgrade(rtld_bind_lock, &lockstate);
984263bc
MD
696 if (obj->pltrel)
697 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
698 else
699 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
700
701 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
702 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL);
703 if (def == NULL)
704 die();
705
706 target = (Elf_Addr)(defobj->relocbase + def->st_value);
707
708 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
709 defobj->strtab + def->st_name, basename(obj->path),
710 (void *)target, basename(defobj->path));
38e4b3b6
SS
711
712 /*
713 * If we have a function call tracing hook, and the
714 * hook would like to keep tracing this one function,
715 * prevent the relocation so we will wind up here
716 * the next time again.
717 *
718 * We don't want to functrace calls from the functracer
719 * to avoid recursive loops.
720 */
721 if (rtld_functrace != NULL && obj != rtld_functrace_obj) {
722 if (rtld_functrace(obj->path,
723 defobj->path,
724 defobj->strtab + def->st_name,
725 stack))
726 do_reloc = 0;
727 }
728
729 if (do_reloc)
fcf53d9b
JM
730 target = reloc_jmpslot(where, target, defobj, obj, rel);
731 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
732 return target;
733}
734
735/*
736 * Error reporting function. Use it like printf. If formats the message
737 * into a buffer, and sets things up so that the next call to dlerror()
738 * will return the message.
739 */
740void
741_rtld_error(const char *fmt, ...)
742{
743 static char buf[512];
744 va_list ap;
745
746 va_start(ap, fmt);
abfcd5b1 747 rtld_vsnprintf(buf, sizeof buf, fmt, ap);
984263bc
MD
748 error_message = buf;
749 va_end(ap);
750}
751
752/*
753 * Return a dynamically-allocated copy of the current error message, if any.
754 */
755static char *
756errmsg_save(void)
757{
758 return error_message == NULL ? NULL : xstrdup(error_message);
759}
760
761/*
762 * Restore the current error message from a copy which was previously saved
763 * by errmsg_save(). The copy is freed.
764 */
765static void
766errmsg_restore(char *saved_msg)
767{
768 if (saved_msg == NULL)
769 error_message = NULL;
770 else {
771 _rtld_error("%s", saved_msg);
772 free(saved_msg);
773 }
774}
775
1c76efe5 776const char *
984263bc
MD
777basename(const char *name)
778{
779 const char *p = strrchr(name, '/');
780 return p != NULL ? p + 1 : name;
781}
782
fcf53d9b
JM
783static struct utsname uts;
784
785static int
786origin_subst_one(char **res, const char *real, const char *kw, const char *subst,
787 char *may_free)
788{
789 const char *p, *p1;
790 char *res1;
791 int subst_len;
792 int kw_len;
793
794 res1 = *res = NULL;
795 p = real;
796 subst_len = kw_len = 0;
797 for (;;) {
798 p1 = strstr(p, kw);
799 if (p1 != NULL) {
800 if (subst_len == 0) {
801 subst_len = strlen(subst);
802 kw_len = strlen(kw);
803 }
804 if (*res == NULL) {
805 *res = xmalloc(PATH_MAX);
806 res1 = *res;
807 }
808 if ((res1 - *res) + subst_len + (p1 - p) >= PATH_MAX) {
809 _rtld_error("Substitution of %s in %s cannot be performed",
810 kw, real);
811 if (may_free != NULL)
812 free(may_free);
813 free(res);
814 return (false);
815 }
816 memcpy(res1, p, p1 - p);
817 res1 += p1 - p;
818 memcpy(res1, subst, subst_len);
819 res1 += subst_len;
820 p = p1 + kw_len;
821 } else {
822 if (*res == NULL) {
823 if (may_free != NULL)
824 *res = may_free;
825 else
826 *res = xstrdup(real);
827 return (true);
828 }
829 *res1 = '\0';
830 if (may_free != NULL)
831 free(may_free);
832 if (strlcat(res1, p, PATH_MAX - (res1 - *res)) >= PATH_MAX) {
833 free(res);
834 return (false);
835 }
836 return (true);
837 }
838 }
839}
840
841static char *
842origin_subst(const char *real, const char *origin_path)
843{
844 char *res1, *res2, *res3, *res4;
845
846 if (uts.sysname[0] == '\0') {
847 if (uname(&uts) != 0) {
848 _rtld_error("utsname failed: %d", errno);
849 return (NULL);
850 }
851 }
852 if (!origin_subst_one(&res1, real, "$ORIGIN", origin_path, NULL) ||
853 !origin_subst_one(&res2, res1, "$OSNAME", uts.sysname, res1) ||
854 !origin_subst_one(&res3, res2, "$OSREL", uts.release, res2) ||
855 !origin_subst_one(&res4, res3, "$PLATFORM", uts.machine, res3))
856 return (NULL);
857 return (res4);
858}
859
984263bc
MD
860static void
861die(void)
862{
863 const char *msg = dlerror();
864
865 if (msg == NULL)
866 msg = "Fatal error";
abfcd5b1
JM
867 rtld_fdputstr(STDERR_FILENO, msg);
868 _exit(1);
984263bc
MD
869}
870
871/*
872 * Process a shared object's DYNAMIC section, and save the important
873 * information in its Obj_Entry structure.
874 */
875static void
b566341b
JM
876digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
877 const Elf_Dyn **dyn_soname)
984263bc
MD
878{
879 const Elf_Dyn *dynp;
880 Needed_Entry **needed_tail = &obj->needed;
984263bc
MD
881 int plttype = DT_REL;
882
b566341b
JM
883 *dyn_rpath = NULL;
884 *dyn_soname = NULL;
885
fcf53d9b 886 obj->bind_now = false;
984263bc
MD
887 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
888 switch (dynp->d_tag) {
889
890 case DT_REL:
891 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
892 break;
893
894 case DT_RELSZ:
895 obj->relsize = dynp->d_un.d_val;
896 break;
897
898 case DT_RELENT:
899 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
900 break;
901
902 case DT_JMPREL:
903 obj->pltrel = (const Elf_Rel *)
904 (obj->relocbase + dynp->d_un.d_ptr);
905 break;
906
907 case DT_PLTRELSZ:
908 obj->pltrelsize = dynp->d_un.d_val;
909 break;
910
911 case DT_RELA:
912 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
913 break;
914
915 case DT_RELASZ:
916 obj->relasize = dynp->d_un.d_val;
917 break;
918
919 case DT_RELAENT:
920 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
921 break;
922
923 case DT_PLTREL:
924 plttype = dynp->d_un.d_val;
925 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
926 break;
927
928 case DT_SYMTAB:
929 obj->symtab = (const Elf_Sym *)
930 (obj->relocbase + dynp->d_un.d_ptr);
931 break;
932
933 case DT_SYMENT:
934 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
935 break;
936
937 case DT_STRTAB:
938 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
939 break;
940
941 case DT_STRSZ:
942 obj->strsize = dynp->d_un.d_val;
943 break;
944
fcf53d9b
JM
945 case DT_VERNEED:
946 obj->verneed = (const Elf_Verneed *) (obj->relocbase +
947 dynp->d_un.d_val);
948 break;
949
950 case DT_VERNEEDNUM:
951 obj->verneednum = dynp->d_un.d_val;
952 break;
953
954 case DT_VERDEF:
955 obj->verdef = (const Elf_Verdef *) (obj->relocbase +
956 dynp->d_un.d_val);
957 break;
958
959 case DT_VERDEFNUM:
960 obj->verdefnum = dynp->d_un.d_val;
961 break;
962
963 case DT_VERSYM:
964 obj->versyms = (const Elf_Versym *)(obj->relocbase +
965 dynp->d_un.d_val);
966 break;
967
984263bc
MD
968 case DT_HASH:
969 {
d697cc44 970 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
984263bc
MD
971 (obj->relocbase + dynp->d_un.d_ptr);
972 obj->nbuckets = hashtab[0];
973 obj->nchains = hashtab[1];
974 obj->buckets = hashtab + 2;
975 obj->chains = obj->buckets + obj->nbuckets;
976 }
977 break;
978
979 case DT_NEEDED:
980 if (!obj->rtld) {
981 Needed_Entry *nep = NEW(Needed_Entry);
982 nep->name = dynp->d_un.d_val;
983 nep->obj = NULL;
984 nep->next = NULL;
985
986 *needed_tail = nep;
987 needed_tail = &nep->next;
988 }
989 break;
990
991 case DT_PLTGOT:
992 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
993 break;
994
995 case DT_TEXTREL:
996 obj->textrel = true;
997 break;
998
999 case DT_SYMBOLIC:
1000 obj->symbolic = true;
1001 break;
1002
1003 case DT_RPATH:
167f7029 1004 case DT_RUNPATH: /* XXX: process separately */
984263bc
MD
1005 /*
1006 * We have to wait until later to process this, because we
1007 * might not have gotten the address of the string table yet.
1008 */
b566341b 1009 *dyn_rpath = dynp;
984263bc
MD
1010 break;
1011
1012 case DT_SONAME:
b566341b 1013 *dyn_soname = dynp;
984263bc
MD
1014 break;
1015
1016 case DT_INIT:
fcf53d9b 1017 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
984263bc
MD
1018 break;
1019
1020 case DT_FINI:
fcf53d9b 1021 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
984263bc
MD
1022 break;
1023
1024 case DT_DEBUG:
1025 /* XXX - not implemented yet */
c3098c28
SS
1026 if (!early)
1027 dbg("Filling in DT_DEBUG entry");
984263bc
MD
1028 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
1029 break;
1030
167f7029 1031 case DT_FLAGS:
fcf53d9b
JM
1032 if ((dynp->d_un.d_val & DF_ORIGIN) && trust)
1033 obj->z_origin = true;
167f7029
JS
1034 if (dynp->d_un.d_val & DF_SYMBOLIC)
1035 obj->symbolic = true;
1036 if (dynp->d_un.d_val & DF_TEXTREL)
1037 obj->textrel = true;
1038 if (dynp->d_un.d_val & DF_BIND_NOW)
1039 obj->bind_now = true;
8301820e
JM
1040 /*if (dynp->d_un.d_val & DF_STATIC_TLS)
1041 ;*/
167f7029
JS
1042 break;
1043
fcf53d9b
JM
1044 case DT_FLAGS_1:
1045 if (dynp->d_un.d_val & DF_1_NOOPEN)
1046 obj->z_noopen = true;
1047 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
1048 obj->z_origin = true;
8301820e
JM
1049 /*if (dynp->d_un.d_val & DF_1_GLOBAL)
1050 XXX ;*/
fcf53d9b
JM
1051 if (dynp->d_un.d_val & DF_1_BIND_NOW)
1052 obj->bind_now = true;
1053 if (dynp->d_un.d_val & DF_1_NODELETE)
1054 obj->z_nodelete = true;
1055 break;
1056
984263bc 1057 default:
fcf53d9b
JM
1058 if (!early) {
1059 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
1060 (long)dynp->d_tag);
1061 }
984263bc
MD
1062 break;
1063 }
1064 }
1065
1066 obj->traced = false;
1067
1068 if (plttype == DT_RELA) {
1069 obj->pltrela = (const Elf_Rela *) obj->pltrel;
1070 obj->pltrel = NULL;
1071 obj->pltrelasize = obj->pltrelsize;
1072 obj->pltrelsize = 0;
1073 }
b566341b
JM
1074}
1075
1076static void
1077digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
1078 const Elf_Dyn *dyn_soname)
1079{
984263bc 1080
fcf53d9b
JM
1081 if (obj->z_origin && obj->origin_path == NULL) {
1082 obj->origin_path = xmalloc(PATH_MAX);
1083 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1)
1084 die();
1085 }
1086
1087 if (dyn_rpath != NULL) {
1088 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
1089 if (obj->z_origin)
1090 obj->rpath = origin_subst(obj->rpath, obj->origin_path);
1091 }
1092
1093 if (dyn_soname != NULL)
1094 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
984263bc
MD
1095}
1096
b566341b
JM
1097static void
1098digest_dynamic(Obj_Entry *obj, int early)
1099{
1100 const Elf_Dyn *dyn_rpath;
1101 const Elf_Dyn *dyn_soname;
1102
1103 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname);
1104 digest_dynamic2(obj, dyn_rpath, dyn_soname);
1105}
1106
984263bc
MD
1107/*
1108 * Process a shared object's program header. This is used only for the
1109 * main program, when the kernel has already loaded the main program
1110 * into memory before calling the dynamic linker. It creates and
1111 * returns an Obj_Entry structure.
1112 */
1113static Obj_Entry *
1114digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
1115{
1116 Obj_Entry *obj;
1117 const Elf_Phdr *phlimit = phdr + phnum;
1118 const Elf_Phdr *ph;
1119 int nsegs = 0;
1120
1121 obj = obj_new();
1122 for (ph = phdr; ph < phlimit; ph++) {
fcf53d9b
JM
1123 if (ph->p_type != PT_PHDR)
1124 continue;
984263bc 1125
fcf53d9b
JM
1126 obj->phdr = phdr;
1127 obj->phsize = ph->p_memsz;
1128 obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
1129 break;
1130 }
1131
1132 for (ph = phdr; ph < phlimit; ph++) {
1133 switch (ph->p_type) {
984263bc
MD
1134
1135 case PT_INTERP:
fcf53d9b 1136 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
984263bc
MD
1137 break;
1138
1139 case PT_LOAD:
1140 if (nsegs == 0) { /* First load segment */
1141 obj->vaddrbase = trunc_page(ph->p_vaddr);
fcf53d9b 1142 obj->mapbase = obj->vaddrbase + obj->relocbase;
984263bc
MD
1143 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
1144 obj->vaddrbase;
1145 } else { /* Last load segment */
1146 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1147 obj->vaddrbase;
1148 }
1149 nsegs++;
1150 break;
1151
1152 case PT_DYNAMIC:
fcf53d9b 1153 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
984263bc 1154 break;
55b88cae
DX
1155
1156 case PT_TLS:
1157 obj->tlsindex = 1;
1158 obj->tlssize = ph->p_memsz;
1159 obj->tlsalign = ph->p_align;
1160 obj->tlsinitsize = ph->p_filesz;
fcf53d9b 1161 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
55b88cae 1162 break;
007f494e
JM
1163
1164 case PT_GNU_RELRO:
1165 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
1166 obj->relro_size = round_page(ph->p_memsz);
1167 break;
984263bc
MD
1168 }
1169 }
1170 if (nsegs < 1) {
1171 _rtld_error("%s: too few PT_LOAD segments", path);
1172 return NULL;
1173 }
1174
1175 obj->entry = entry;
1176 return obj;
1177}
1178
1179static Obj_Entry *
1180dlcheck(void *handle)
1181{
1182 Obj_Entry *obj;
1183
1184 for (obj = obj_list; obj != NULL; obj = obj->next)
1185 if (obj == (Obj_Entry *) handle)
1186 break;
1187
1188 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1189 _rtld_error("Invalid shared object handle %p", handle);
1190 return NULL;
1191 }
1192 return obj;
1193}
1194
1195/*
1196 * If the given object is already in the donelist, return true. Otherwise
1197 * add the object to the list and return false.
1198 */
1199static bool
1200donelist_check(DoneList *dlp, const Obj_Entry *obj)
1201{
1202 unsigned int i;
1203
1204 for (i = 0; i < dlp->num_used; i++)
1205 if (dlp->objs[i] == obj)
1206 return true;
1207 /*
1208 * Our donelist allocation should always be sufficient. But if
1209 * our threads locking isn't working properly, more shared objects
1210 * could have been loaded since we allocated the list. That should
1211 * never happen, but we'll handle it properly just in case it does.
1212 */
1213 if (dlp->num_used < dlp->num_alloc)
1214 dlp->objs[dlp->num_used++] = obj;
1215 return false;
1216}
1217
1218/*
1219 * Hash function for symbol table lookup. Don't even think about changing
1220 * this. It is specified by the System V ABI.
1221 */
1222unsigned long
1223elf_hash(const char *name)
1224{
1225 const unsigned char *p = (const unsigned char *) name;
1226 unsigned long h = 0;
1227 unsigned long g;
1228
1229 while (*p != '\0') {
1230 h = (h << 4) + *p++;
1231 if ((g = h & 0xf0000000) != 0)
1232 h ^= g >> 24;
1233 h &= ~g;
1234 }
1235 return h;
1236}
1237
1238/*
1239 * Find the library with the given name, and return its full pathname.
1240 * The returned string is dynamically allocated. Generates an error
1241 * message and returns NULL if the library cannot be found.
1242 *
1243 * If the second argument is non-NULL, then it refers to an already-
1244 * loaded shared object, whose library search path will be searched.
1245 *
1246 * The search order is:
984263bc 1247 * LD_LIBRARY_PATH
4e390e27 1248 * rpath in the referencing file
984263bc
MD
1249 * ldconfig hints
1250 * /usr/lib
1251 */
1252static char *
fcf53d9b 1253find_library(const char *xname, const Obj_Entry *refobj)
984263bc
MD
1254{
1255 char *pathname;
fcf53d9b 1256 char *name;
984263bc 1257
fcf53d9b
JM
1258 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */
1259 if (xname[0] != '/' && !trust) {
984263bc 1260 _rtld_error("Absolute pathname required for shared object \"%s\"",
fcf53d9b 1261 xname);
984263bc
MD
1262 return NULL;
1263 }
fcf53d9b
JM
1264 if (refobj != NULL && refobj->z_origin)
1265 return origin_subst(xname, refobj->origin_path);
1266 else
1267 return xstrdup(xname);
984263bc
MD
1268 }
1269
fcf53d9b
JM
1270 if (libmap_disable || (refobj == NULL) ||
1271 (name = lm_find(refobj->path, xname)) == NULL)
1272 name = (char *)xname;
1273
984263bc
MD
1274 dbg(" Searching for \"%s\"", name);
1275
1276 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
1277 (refobj != NULL &&
1278 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1279 (pathname = search_library_path(name, gethints())) != NULL ||
1280 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
1281 return pathname;
1282
446c0d3a
JS
1283 if(refobj != NULL && refobj->path != NULL) {
1284 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
1285 name, basename(refobj->path));
1286 } else {
1287 _rtld_error("Shared object \"%s\" not found", name);
1288 }
984263bc
MD
1289 return NULL;
1290}
1291
1292/*
1293 * Given a symbol number in a referencing object, find the corresponding
1294 * definition of the symbol. Returns a pointer to the symbol, or NULL if
1295 * no definition was found. Returns a pointer to the Obj_Entry of the
1296 * defining object via the reference parameter DEFOBJ_OUT.
1297 */
1298const Elf_Sym *
1299find_symdef(unsigned long symnum, const Obj_Entry *refobj,
fcf53d9b 1300 const Obj_Entry **defobj_out, int flags, SymCache *cache)
984263bc
MD
1301{
1302 const Elf_Sym *ref;
1303 const Elf_Sym *def;
1304 const Obj_Entry *defobj;
fcf53d9b 1305 const Ver_Entry *ventry;
984263bc
MD
1306 const char *name;
1307 unsigned long hash;
1308
1309 /*
1310 * If we have already found this symbol, get the information from
1311 * the cache.
1312 */
1313 if (symnum >= refobj->nchains)
1314 return NULL; /* Bad object */
1315 if (cache != NULL && cache[symnum].sym != NULL) {
1316 *defobj_out = cache[symnum].obj;
1317 return cache[symnum].sym;
1318 }
1319
1320 ref = refobj->symtab + symnum;
1321 name = refobj->strtab + ref->st_name;
984263bc
MD
1322 defobj = NULL;
1323
0e588128
SS
1324 /*
1325 * We don't have to do a full scale lookup if the symbol is local.
1326 * We know it will bind to the instance in this load module; to
1327 * which we already have a pointer (ie ref). By not doing a lookup,
1328 * we not only improve performance, but it also avoids unresolvable
1329 * symbols when local symbols are not in the hash table.
1330 *
1331 * This might occur for TLS module relocations, which simply use
1332 * symbol 0.
1333 */
1334 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1335 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
c3098c28
SS
1336 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1337 symnum);
1338 }
fcf53d9b 1339 ventry = fetch_ventry(refobj, symnum);
0e588128 1340 hash = elf_hash(name);
fcf53d9b 1341 def = symlook_default(name, hash, refobj, &defobj, ventry, flags);
0e588128 1342 } else {
c3098c28
SS
1343 def = ref;
1344 defobj = refobj;
0e588128 1345 }
984263bc
MD
1346
1347 /*
1348 * If we found no definition and the reference is weak, treat the
1349 * symbol as having the value zero.
1350 */
1351 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1352 def = &sym_zero;
1353 defobj = obj_main;
1354 }
1355
1356 if (def != NULL) {
1357 *defobj_out = defobj;
1358 /* Record the information in the cache to avoid subsequent lookups. */
1359 if (cache != NULL) {
1360 cache[symnum].sym = def;
1361 cache[symnum].obj = defobj;
1362 }
fcf53d9b
JM
1363 } else {
1364 if (refobj != &obj_rtld)
1365 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1366 }
984263bc
MD
1367 return def;
1368}
1369
1370/*
1371 * Return the search path from the ldconfig hints file, reading it if
1372 * necessary. Returns NULL if there are problems with the hints file,
1373 * or if the search path there is empty.
1374 */
1375static const char *
1376gethints(void)
1377{
1378 static char *hints;
1379
1380 if (hints == NULL) {
1381 int fd;
1382 struct elfhints_hdr hdr;
1383 char *p;
1384
1385 /* Keep from trying again in case the hints file is bad. */
1386 hints = "";
1387
fcf53d9b 1388 if ((fd = open(ld_elf_hints_path, O_RDONLY)) == -1)
984263bc
MD
1389 return NULL;
1390 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1391 hdr.magic != ELFHINTS_MAGIC ||
1392 hdr.version != 1) {
1393 close(fd);
1394 return NULL;
1395 }
1396 p = xmalloc(hdr.dirlistlen + 1);
1397 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
fcf53d9b 1398 read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) {
984263bc
MD
1399 free(p);
1400 close(fd);
1401 return NULL;
1402 }
1403 hints = p;
1404 close(fd);
1405 }
1406 return hints[0] != '\0' ? hints : NULL;
1407}
1408
1409static void
1410init_dag(Obj_Entry *root)
1411{
1412 DoneList donelist;
1413
fcf53d9b
JM
1414 if (root->dag_inited)
1415 return;
984263bc
MD
1416 donelist_init(&donelist);
1417 init_dag1(root, root, &donelist);
1418}
1419
1420static void
1421init_dag1(Obj_Entry *root, Obj_Entry *obj, DoneList *dlp)
1422{
1423 const Needed_Entry *needed;
1424
1425 if (donelist_check(dlp, obj))
1426 return;
fcf53d9b 1427
984263bc
MD
1428 objlist_push_tail(&obj->dldags, root);
1429 objlist_push_tail(&root->dagmembers, obj);
1430 for (needed = obj->needed; needed != NULL; needed = needed->next)
1431 if (needed->obj != NULL)
1432 init_dag1(root, needed->obj, dlp);
fcf53d9b 1433 root->dag_inited = true;
984263bc
MD
1434}
1435
1436/*
1437 * Initialize the dynamic linker. The argument is the address at which
1438 * the dynamic linker has been mapped into memory. The primary task of
1439 * this function is to relocate the dynamic linker.
1440 */
1441static void
b566341b 1442init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
984263bc 1443{
c3098c28 1444 Obj_Entry objtmp; /* Temporary rtld object */
b566341b
JM
1445 const Elf_Dyn *dyn_rpath;
1446 const Elf_Dyn *dyn_soname;
c3098c28 1447
984263bc
MD
1448 /*
1449 * Conjure up an Obj_Entry structure for the dynamic linker.
1450 *
fcf53d9b
JM
1451 * The "path" member can't be initialized yet because string constants
1452 * cannot yet be accessed. Below we will set it correctly.
984263bc 1453 */
4648abf3 1454 memset(&objtmp, 0, sizeof(objtmp));
c3098c28
SS
1455 objtmp.path = NULL;
1456 objtmp.rtld = true;
1457 objtmp.mapbase = mapbase;
984263bc 1458#ifdef PIC
c3098c28 1459 objtmp.relocbase = mapbase;
984263bc 1460#endif
fcf53d9b 1461 if (RTLD_IS_DYNAMIC()) {
c3098c28 1462 objtmp.dynamic = rtld_dynamic(&objtmp);
b566341b 1463 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname);
c3098c28
SS
1464 assert(objtmp.needed == NULL);
1465 assert(!objtmp.textrel);
984263bc
MD
1466
1467 /*
1468 * Temporarily put the dynamic linker entry into the object list, so
1469 * that symbols can be found.
1470 */
984263bc 1471
c3098c28 1472 relocate_objects(&objtmp, true, &objtmp);
984263bc
MD
1473 }
1474
c3098c28 1475 /* Initialize the object list. */
984263bc 1476 obj_tail = &obj_list;
c3098c28
SS
1477
1478 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1479 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
984263bc 1480
b566341b
JM
1481#ifdef ENABLE_OSRELDATE
1482 if (aux_info[AT_OSRELDATE] != NULL)
1483 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
1484#endif
1485
1486 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname);
1487
984263bc 1488 /* Replace the path with a dynamically allocated copy. */
c3098c28 1489 obj_rtld.path = xstrdup(PATH_RTLD);
984263bc
MD
1490
1491 r_debug.r_brk = r_debug_state;
1492 r_debug.r_state = RT_CONSISTENT;
1493}
1494
1495/*
1496 * Add the init functions from a needed object list (and its recursive
1497 * needed objects) to "list". This is not used directly; it is a helper
1498 * function for initlist_add_objects(). The write lock must be held
1499 * when this function is called.
1500 */
1501static void
1502initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1503{
1504 /* Recursively process the successor needed objects. */
1505 if (needed->next != NULL)
1506 initlist_add_neededs(needed->next, list);
1507
1508 /* Process the current needed object. */
1509 if (needed->obj != NULL)
1510 initlist_add_objects(needed->obj, &needed->obj->next, list);
1511}
1512
1513/*
1514 * Scan all of the DAGs rooted in the range of objects from "obj" to
1515 * "tail" and add their init functions to "list". This recurses over
1516 * the DAGs and ensure the proper init ordering such that each object's
1517 * needed libraries are initialized before the object itself. At the
1518 * same time, this function adds the objects to the global finalization
1519 * list "list_fini" in the opposite order. The write lock must be
1520 * held when this function is called.
1521 */
1522static void
1523initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1524{
fcf53d9b 1525 if (obj->init_scanned || obj->init_done)
984263bc 1526 return;
fcf53d9b 1527 obj->init_scanned = true;
984263bc
MD
1528
1529 /* Recursively process the successor objects. */
1530 if (&obj->next != tail)
1531 initlist_add_objects(obj->next, tail, list);
1532
1533 /* Recursively process the needed objects. */
1534 if (obj->needed != NULL)
1535 initlist_add_neededs(obj->needed, list);
1536
1537 /* Add the object to the init list. */
fcf53d9b 1538 if (obj->init != (Elf_Addr)NULL)
984263bc
MD
1539 objlist_push_tail(list, obj);
1540
1541 /* Add the object to the global fini list in the reverse order. */
fcf53d9b 1542 if (obj->fini != (Elf_Addr)NULL && !obj->on_fini_list) {
984263bc 1543 objlist_push_head(&list_fini, obj);
fcf53d9b
JM
1544 obj->on_fini_list = true;
1545 }
984263bc
MD
1546}
1547
fcf53d9b
JM
1548#ifndef FPTR_TARGET
1549#define FPTR_TARGET(f) ((Elf_Addr) (f))
1550#endif
1551
984263bc
MD
1552static bool
1553is_exported(const Elf_Sym *def)
1554{
d697cc44 1555 Elf_Addr value;
984263bc
MD
1556 const func_ptr_type *p;
1557
d697cc44 1558 value = (Elf_Addr)(obj_rtld.relocbase + def->st_value);
fcf53d9b
JM
1559 for (p = exports; *p != NULL; p++)
1560 if (FPTR_TARGET(*p) == value)
984263bc
MD
1561 return true;
1562 return false;
1563}
1564
1565/*
1566 * Given a shared object, traverse its list of needed objects, and load
1567 * each of them. Returns 0 on success. Generates an error message and
1568 * returns -1 on failure.
1569 */
1570static int
fcf53d9b 1571load_needed_objects(Obj_Entry *first, int flags)
984263bc 1572{
fcf53d9b 1573 Obj_Entry *obj, *obj1;
984263bc
MD
1574
1575 for (obj = first; obj != NULL; obj = obj->next) {
1576 Needed_Entry *needed;
1577
1578 for (needed = obj->needed; needed != NULL; needed = needed->next) {
fcf53d9b
JM
1579 obj1 = needed->obj = load_object(obj->strtab + needed->name, obj,
1580 flags & ~RTLD_LO_NOLOAD);
1581 if (obj1 == NULL && !ld_tracing)
984263bc 1582 return -1;
fcf53d9b
JM
1583 if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) {
1584 dbg("obj %s nodelete", obj1->path);
1585 init_dag(obj1);
1586 ref_dag(obj1);
1587 obj1->ref_nodel = true;
984263bc
MD
1588 }
1589 }
1590 }
fcf53d9b 1591 return (0);
984263bc
MD
1592}
1593
38e4b3b6
SS
1594#define RTLD_FUNCTRACE "_rtld_functrace"
1595
984263bc
MD
1596static int
1597load_preload_objects(void)
1598{
1599 char *p = ld_preload;
1600 static const char delim[] = " \t:;";
1601
1602 if (p == NULL)
eecd52b2 1603 return 0;
984263bc
MD
1604
1605 p += strspn(p, delim);
1606 while (*p != '\0') {
1607 size_t len = strcspn(p, delim);
984263bc 1608 char savech;
38e4b3b6
SS
1609 Obj_Entry *obj;
1610 const Elf_Sym *sym;
984263bc
MD
1611
1612 savech = p[len];
1613 p[len] = '\0';
fcf53d9b 1614 obj = load_object(p, NULL, 0);
38e4b3b6 1615 if (obj == NULL)
984263bc
MD
1616 return -1; /* XXX - cleanup */
1617 p[len] = savech;
1618 p += len;
1619 p += strspn(p, delim);
38e4b3b6
SS
1620
1621 /* Check for the magic tracing function */
fcf53d9b 1622 sym = symlook_obj(RTLD_FUNCTRACE, elf_hash(RTLD_FUNCTRACE), obj, NULL, 1);
38e4b3b6
SS
1623 if (sym != NULL) {
1624 rtld_functrace = (void *)(obj->relocbase + sym->st_value);
1625 rtld_functrace_obj = obj;
1626 }
984263bc 1627 }
fcf53d9b 1628 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
984263bc
MD
1629 return 0;
1630}
1631
b6a22d96 1632/*
fcf53d9b
JM
1633 * Load a shared object into memory, if it is not already loaded.
1634 *
1635 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1636 * on failure.
b6a22d96
JS
1637 */
1638static Obj_Entry *
fcf53d9b 1639load_object(const char *name, const Obj_Entry *refobj, int flags)
b6a22d96
JS
1640{
1641 Obj_Entry *obj;
fcf53d9b
JM
1642 int fd = -1;
1643 struct stat sb;
1644 char *path;
b6a22d96 1645
fcf53d9b
JM
1646 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1647 if (object_match_name(obj, name))
1648 return obj;
b6a22d96 1649
fcf53d9b
JM
1650 path = find_library(name, refobj);
1651 if (path == NULL)
1652 return NULL;
2d6b58a8 1653
fcf53d9b
JM
1654 /*
1655 * If we didn't find a match by pathname, open the file and check
1656 * again by device and inode. This avoids false mismatches caused
1657 * by multiple links or ".." in pathnames.
1658 *
1659 * To avoid a race, we open the file and use fstat() rather than
1660 * using stat().
1661 */
1662 if ((fd = open(path, O_RDONLY)) == -1) {
2d6b58a8 1663 _rtld_error("Cannot open \"%s\"", path);
fcf53d9b
JM
1664 free(path);
1665 return NULL;
2d6b58a8 1666 }
fcf53d9b 1667 if (fstat(fd, &sb) == -1) {
2d6b58a8 1668 _rtld_error("Cannot fstat \"%s\"", path);
fcf53d9b
JM
1669 close(fd);
1670 free(path);
2d6b58a8
JS
1671 return NULL;
1672 }
fcf53d9b
JM
1673 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1674 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
2d6b58a8 1675 break;
fcf53d9b
JM
1676 if (obj != NULL) {
1677 object_add_name(obj, name);
1678 free(path);
1679 close(fd);
1680 return obj;
1681 }
1682 if (flags & RTLD_LO_NOLOAD) {
1683 free(path);
8bdeb8d3 1684 close(fd);
fcf53d9b 1685 return (NULL);
2d6b58a8
JS
1686 }
1687
fcf53d9b
JM
1688 /* First use of this object, so we must map it in */
1689 obj = do_load_object(fd, name, path, &sb, flags);
1690 if (obj == NULL)
1691 free(path);
1692 close(fd);
1693
1694 return obj;
2d6b58a8
JS
1695}
1696
984263bc 1697static Obj_Entry *
fcf53d9b
JM
1698do_load_object(int fd, const char *name, char *path, struct stat *sbp,
1699 int flags)
984263bc
MD
1700{
1701 Obj_Entry *obj;
fcf53d9b 1702 struct statfs fs;
984263bc 1703
fcf53d9b
JM
1704 /*
1705 * but first, make sure that environment variables haven't been
1706 * used to circumvent the noexec flag on a filesystem.
1707 */
1708 if (dangerous_ld_env) {
1709 if (fstatfs(fd, &fs) != 0) {
1710 _rtld_error("Cannot fstatfs \"%s\"", path);
1711 return NULL;
1712 }
1713 if (fs.f_flags & MNT_NOEXEC) {
1714 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
1715 return NULL;
1716 }
984263bc 1717 }
2d6b58a8 1718 dbg("loading \"%s\"", path);
fcf53d9b
JM
1719 obj = map_object(fd, path, sbp);
1720 if (obj == NULL)
2d6b58a8 1721 return NULL;
984263bc 1722
fcf53d9b 1723 object_add_name(obj, name);
2d6b58a8 1724 obj->path = path;
c3098c28 1725 digest_dynamic(obj, 0);
fcf53d9b
JM
1726 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
1727 RTLD_LO_DLOPEN) {
1728 dbg("refusing to load non-loadable \"%s\"", obj->path);
1729 _rtld_error("Cannot dlopen non-loadable %s", obj->path);
1730 munmap(obj->mapbase, obj->mapsize);
1731 obj_free(obj);
1732 return (NULL);
1733 }
984263bc 1734
2d6b58a8
JS
1735 *obj_tail = obj;
1736 obj_tail = &obj->next;
1737 obj_count++;
fcf53d9b 1738 obj_loads++;
2d6b58a8 1739 linkmap_add(obj); /* for GDB & dlinfo() */
984263bc 1740
139b8f34
SW
1741 dbg(" %p .. %p: %s", obj->mapbase,
1742 obj->mapbase + obj->mapsize - 1, obj->path);
2d6b58a8 1743 if (obj->textrel)
fcf53d9b
JM
1744 dbg(" WARNING: %s has impure text", obj->path);
1745 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
1746 obj->path);
984263bc 1747
984263bc
MD
1748 return obj;
1749}
1750
984263bc
MD
1751static Obj_Entry *
1752obj_from_addr(const void *addr)
1753{
984263bc
MD
1754 Obj_Entry *obj;
1755
984263bc 1756 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc
MD
1757 if (addr < (void *) obj->mapbase)
1758 continue;
c6873e56 1759 if (addr < (void *) (obj->mapbase + obj->mapsize))
984263bc
MD
1760 return obj;
1761 }
1762 return NULL;
1763}
1764
1765/*
1766 * Call the finalization functions for each of the objects in "list"
fcf53d9b
JM
1767 * belonging to the DAG of "root" and referenced once. If NULL "root"
1768 * is specified, every finalization function will be called regardless
1769 * of the reference count and the list elements won't be freed. All of
1770 * the objects are expected to have non-NULL fini functions.
984263bc
MD
1771 */
1772static void
fcf53d9b 1773objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
984263bc
MD
1774{
1775 Objlist_Entry *elm;
1776 char *saved_msg;
1777
fcf53d9b
JM
1778 assert(root == NULL || root->refcount == 1);
1779
984263bc
MD
1780 /*
1781 * Preserve the current error message since a fini function might
1782 * call into the dynamic linker and overwrite it.
1783 */
1784 saved_msg = errmsg_save();
fcf53d9b
JM
1785 do {
1786 STAILQ_FOREACH(elm, list, link) {
1787 if (root != NULL && (elm->obj->refcount != 1 ||
1788 objlist_find(&root->dagmembers, elm->obj) == NULL))
1789 continue;
1790 dbg("calling fini function for %s at %p", elm->obj->path,
1791 (void *)elm->obj->fini);
1792 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini, 0, 0,
1793 elm->obj->path);
1794 /* Remove object from fini list to prevent recursive invocation. */
1795 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1796 /*
1797 * XXX: If a dlopen() call references an object while the
1798 * fini function is in progress, we might end up trying to
1799 * unload the referenced object in dlclose() or the object
1800 * won't be unloaded although its fini function has been
1801 * called.
1802 */
1803 lock_release(rtld_bind_lock, lockstate);
1804 call_initfini_pointer(elm->obj, elm->obj->fini);
1805 wlock_acquire(rtld_bind_lock, lockstate);
1806 /* No need to free anything if process is going down. */
1807 if (root != NULL)
1808 free(elm);
1809 /*
1810 * We must restart the list traversal after every fini call
1811 * because a dlclose() call from the fini function or from
1812 * another thread might have modified the reference counts.
1813 */
1814 break;
984263bc 1815 }
fcf53d9b 1816 } while (elm != NULL);
984263bc
MD
1817 errmsg_restore(saved_msg);
1818}
1819
1820/*
1821 * Call the initialization functions for each of the objects in
1822 * "list". All of the objects are expected to have non-NULL init
1823 * functions.
1824 */
1825static void
fcf53d9b 1826objlist_call_init(Objlist *list, RtldLockState *lockstate)
984263bc
MD
1827{
1828 Objlist_Entry *elm;
fcf53d9b 1829 Obj_Entry *obj;
984263bc
MD
1830 char *saved_msg;
1831
fcf53d9b
JM
1832 /*
1833 * Clean init_scanned flag so that objects can be rechecked and
1834 * possibly initialized earlier if any of vectors called below
1835 * cause the change by using dlopen.
1836 */
1837 for (obj = obj_list; obj != NULL; obj = obj->next)
1838 obj->init_scanned = false;
1839
984263bc
MD
1840 /*
1841 * Preserve the current error message since an init function might
1842 * call into the dynamic linker and overwrite it.
1843 */
1844 saved_msg = errmsg_save();
1845 STAILQ_FOREACH(elm, list, link) {
fcf53d9b
JM
1846 if (elm->obj->init_done) /* Initialized early. */
1847 continue;
1848 dbg("calling init function for %s at %p", elm->obj->path,
1849 (void *)elm->obj->init);
1850 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init, 0, 0,
1851 elm->obj->path);
1852 /*
1853 * Race: other thread might try to use this object before current
1854 * one completes the initilization. Not much can be done here
1855 * without better locking.
1856 */
1857 elm->obj->init_done = true;
1858 lock_release(rtld_bind_lock, lockstate);
1859 call_initfini_pointer(elm->obj, elm->obj->init);
1860 wlock_acquire(rtld_bind_lock, lockstate);
984263bc
MD
1861 }
1862 errmsg_restore(saved_msg);
1863}
1864
1865static void
1866objlist_clear(Objlist *list)
1867{
1868 Objlist_Entry *elm;
1869
1870 while (!STAILQ_EMPTY(list)) {
1871 elm = STAILQ_FIRST(list);
1872 STAILQ_REMOVE_HEAD(list, link);
1873 free(elm);
1874 }
1875}
1876
1877static Objlist_Entry *
1878objlist_find(Objlist *list, const Obj_Entry *obj)
1879{
1880 Objlist_Entry *elm;
1881
1882 STAILQ_FOREACH(elm, list, link)
1883 if (elm->obj == obj)
1884 return elm;
1885 return NULL;
1886}
1887
1888static void
1889objlist_init(Objlist *list)
1890{
1891 STAILQ_INIT(list);
1892}
1893
1894static void
1895objlist_push_head(Objlist *list, Obj_Entry *obj)
1896{
1897 Objlist_Entry *elm;
1898
1899 elm = NEW(Objlist_Entry);
1900 elm->obj = obj;
1901 STAILQ_INSERT_HEAD(list, elm, link);
1902}
1903
1904static void
1905objlist_push_tail(Objlist *list, Obj_Entry *obj)
1906{
1907 Objlist_Entry *elm;
1908
1909 elm = NEW(Objlist_Entry);
1910 elm->obj = obj;
1911 STAILQ_INSERT_TAIL(list, elm, link);
1912}
1913
1914static void
1915objlist_remove(Objlist *list, Obj_Entry *obj)
1916{
1917 Objlist_Entry *elm;
1918
1919 if ((elm = objlist_find(list, obj)) != NULL) {
1920 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1921 free(elm);
1922 }
1923}
1924
984263bc
MD
1925/*
1926 * Relocate newly-loaded shared objects. The argument is a pointer to
1927 * the Obj_Entry for the first such object. All objects from the first
1928 * to the end of the list of objects are relocated. Returns 0 on success,
1929 * or -1 on failure.
1930 */
1931static int
c3098c28 1932relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj)
984263bc
MD
1933{
1934 Obj_Entry *obj;
1935
1936 for (obj = first; obj != NULL; obj = obj->next) {
c3098c28 1937 if (obj != rtldobj)
984263bc
MD
1938 dbg("relocating \"%s\"", obj->path);
1939 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL ||
1940 obj->symtab == NULL || obj->strtab == NULL) {
1941 _rtld_error("%s: Shared object has no run-time symbol table",
1942 obj->path);
1943 return -1;
1944 }
1945
1946 if (obj->textrel) {
1947 /* There are relocations to the write-protected text segment. */
1948 if (mprotect(obj->mapbase, obj->textsize,
1949 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
1950 _rtld_error("%s: Cannot write-enable text segment: %s",
1951 obj->path, strerror(errno));
1952 return -1;
1953 }
1954 }
1955
1956 /* Process the non-PLT relocations. */
c3098c28 1957 if (reloc_non_plt(obj, rtldobj))
984263bc
MD
1958 return -1;
1959
4b89341e
MD
1960 /*
1961 * Reprotect the text segment. Make sure it is included in the
1962 * core dump since we modified it. This unfortunately causes the
1963 * entire text segment to core-out but we don't have much of a
1964 * choice. We could try to only reenable core dumps on pages
1965 * in which relocations occured but that is likely most of the text
1966 * pages anyway, and even that would not work because the rest of
1967 * the text pages would wind up as a read-only OBJT_DEFAULT object
1968 * (created due to our modifications) backed by the original OBJT_VNODE
1969 * object, and the ELF coredump code is currently only able to dump
1970 * vnode records for pure vnode-backed mappings, not vnode backings
1971 * to memory objects.
1972 */
1973 if (obj->textrel) {
1974 madvise(obj->mapbase, obj->textsize, MADV_CORE);
984263bc
MD
1975 if (mprotect(obj->mapbase, obj->textsize,
1976 PROT_READ|PROT_EXEC) == -1) {
1977 _rtld_error("%s: Cannot write-protect text segment: %s",
1978 obj->path, strerror(errno));
1979 return -1;
1980 }
1981 }
1982
1983 /* Process the PLT relocations. */
1984 if (reloc_plt(obj) == -1)
1985 return -1;
1986 /* Relocate the jump slots if we are doing immediate binding. */
167f7029 1987 if (obj->bind_now || bind_now)
984263bc
MD
1988 if (reloc_jmpslots(obj) == -1)
1989 return -1;
1990
007f494e
JM
1991 /* Set the special PLT or GOT entries. */
1992 init_pltgot(obj);
984263bc
MD
1993
1994 /*
1995 * Set up the magic number and version in the Obj_Entry. These
1996 * were checked in the crt1.o from the original ElfKit, so we
1997 * set them for backward compatibility.
1998 */
1999 obj->magic = RTLD_MAGIC;
2000 obj->version = RTLD_VERSION;
2001
007f494e
JM
2002 /*
2003 * Set relocated data to read-only status if protection specified
2004 */
2005
2006 if (obj->relro_size) {
2007 if (mprotect(obj->relro_page, obj->relro_size, PROT_READ) == -1) {
2008 _rtld_error("%s: Cannot enforce relro relocation: %s",
2009 obj->path, strerror(errno));
2010 return -1;
2011 }
2012 }
984263bc
MD
2013 }
2014
0c151ba0 2015 return (0);
984263bc
MD
2016}
2017
2018/*
2019 * Cleanup procedure. It will be called (by the atexit mechanism) just
2020 * before the process exits.
2021 */
2022static void
2023rtld_exit(void)
2024{
fcf53d9b 2025 RtldLockState lockstate;
984263bc 2026
fcf53d9b 2027 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc 2028 dbg("rtld_exit()");
fcf53d9b 2029 objlist_call_fini(&list_fini, NULL, &lockstate);
984263bc 2030 /* No need to remove the items from the list, since we are exiting. */
fcf53d9b
JM
2031 if (!libmap_disable)
2032 lm_fini();
2033 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2034}
2035
2036static void *
2037path_enumerate(const char *path, path_enum_proc callback, void *arg)
2038{
2039 if (path == NULL)
2040 return (NULL);
2041
2042 path += strspn(path, ":;");
2043 while (*path != '\0') {
2044 size_t len;
2045 char *res;
2046
2047 len = strcspn(path, ":;");
2048 res = callback(path, len, arg);
2049
2050 if (res != NULL)
2051 return (res);
2052
2053 path += len;
2054 path += strspn(path, ":;");
2055 }
2056
2057 return (NULL);
2058}
2059
2060struct try_library_args {
2061 const char *name;
2062 size_t namelen;
2063 char *buffer;
2064 size_t buflen;
2065};
2066
2067static void *
2068try_library_path(const char *dir, size_t dirlen, void *param)
2069{
2070 struct try_library_args *arg;
2071
2072 arg = param;
2073 if (*dir == '/' || trust) {
2074 char *pathname;
2075
2076 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
2077 return (NULL);
2078
2079 pathname = arg->buffer;
2080 strncpy(pathname, dir, dirlen);
2081 pathname[dirlen] = '/';
2082 strcpy(pathname + dirlen + 1, arg->name);
2083
2084 dbg(" Trying \"%s\"", pathname);
2085 if (access(pathname, F_OK) == 0) { /* We found it */
2086 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
2087 strcpy(pathname, arg->buffer);
2088 return (pathname);
2089 }
2090 }
2091 return (NULL);
2092}
2093
2094static char *
2095search_library_path(const char *name, const char *path)
2096{
2097 char *p;
2098 struct try_library_args arg;
2099
2100 if (path == NULL)
2101 return NULL;
2102
2103 arg.name = name;
2104 arg.namelen = strlen(name);
2105 arg.buffer = xmalloc(PATH_MAX);
2106 arg.buflen = PATH_MAX;
2107
2108 p = path_enumerate(path, try_library_path, &arg);
2109
2110 free(arg.buffer);
2111
2112 return (p);
2113}
2114
2115int
2116dlclose(void *handle)
2117{
2118 Obj_Entry *root;
fcf53d9b 2119 RtldLockState lockstate;
984263bc 2120
fcf53d9b 2121 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2122 root = dlcheck(handle);
2123 if (root == NULL) {
fcf53d9b 2124 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2125 return -1;
2126 }
fcf53d9b
JM
2127 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
2128 root->path);
984263bc
MD
2129
2130 /* Unreference the object and its dependencies. */
2131 root->dl_refcount--;
139b8f34 2132
fcf53d9b 2133 if (root->refcount == 1) {
984263bc 2134 /*
fcf53d9b
JM
2135 * The object will be no longer referenced, so we must unload it.
2136 * First, call the fini functions.
984263bc 2137 */
fcf53d9b
JM
2138 objlist_call_fini(&list_fini, root, &lockstate);
2139
2140 unref_dag(root);
984263bc
MD
2141
2142 /* Finish cleaning up the newly-unreferenced objects. */
2143 GDB_STATE(RT_DELETE,&root->linkmap);
2144 unload_object(root);
2145 GDB_STATE(RT_CONSISTENT,NULL);
fcf53d9b
JM
2146 } else
2147 unref_dag(root);
2148
2149 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
2150 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2151 return 0;
2152}
2153
fcf53d9b 2154char *
984263bc
MD
2155dlerror(void)
2156{
2157 char *msg = error_message;
2158 error_message = NULL;
2159 return msg;
2160}
2161
984263bc
MD
2162void *
2163dlopen(const char *name, int mode)
2164{
2165 Obj_Entry **old_obj_tail;
2166 Obj_Entry *obj;
2167 Objlist initlist;
fcf53d9b
JM
2168 RtldLockState lockstate;
2169 int result, lo_flags;
984263bc 2170
fcf53d9b 2171 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
984263bc
MD
2172 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
2173 if (ld_tracing != NULL)
2174 environ = (char **)*get_program_var_addr("environ");
fcf53d9b
JM
2175 lo_flags = RTLD_LO_DLOPEN;
2176 if (mode & RTLD_NODELETE)
2177 lo_flags |= RTLD_LO_NODELETE;
2178 if (mode & RTLD_NOLOAD)
2179 lo_flags |= RTLD_LO_NOLOAD;
2180 if (ld_tracing != NULL)
2181 lo_flags |= RTLD_LO_TRACE;
984263bc
MD
2182
2183 objlist_init(&initlist);
2184
fcf53d9b 2185 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2186 GDB_STATE(RT_ADD,NULL);
2187
2188 old_obj_tail = obj_tail;
2189 obj = NULL;
2190 if (name == NULL) {
2191 obj = obj_main;
2192 obj->refcount++;
2193 } else {
fcf53d9b 2194 obj = load_object(name, obj_main, lo_flags);
984263bc
MD
2195 }
2196
2197 if (obj) {
2198 obj->dl_refcount++;
139b8f34 2199 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
984263bc
MD
2200 objlist_push_tail(&list_global, obj);
2201 mode &= RTLD_MODEMASK;
2202 if (*old_obj_tail != NULL) { /* We loaded something new. */
2203 assert(*old_obj_tail == obj);
fcf53d9b
JM
2204 result = load_needed_objects(obj, RTLD_LO_DLOPEN);
2205 init_dag(obj);
2206 ref_dag(obj);
2207 if (result != -1)
2208 result = rtld_verify_versions(&obj->dagmembers);
984263bc
MD
2209 if (result != -1 && ld_tracing)
2210 goto trace;
984263bc 2211 if (result == -1 ||
fcf53d9b 2212 (relocate_objects(obj, mode == RTLD_NOW, &obj_rtld)) == -1) {
984263bc
MD
2213 obj->dl_refcount--;
2214 unref_dag(obj);
2215 if (obj->refcount == 0)
2216 unload_object(obj);
2217 obj = NULL;
2218 } else {
2219 /* Make list of init functions to call. */
2220 initlist_add_objects(obj, &obj->next, &initlist);
2221 }
fcf53d9b
JM
2222 } else {
2223
2224 /*
2225 * Bump the reference counts for objects on this DAG. If
2226 * this is the first dlopen() call for the object that was
2227 * already loaded as a dependency, initialize the dag
2228 * starting at it.
2229 */
2230 init_dag(obj);
2231 ref_dag(obj);
2232
2233 if ((lo_flags & RTLD_LO_TRACE) != 0)
2234 goto trace;
2235 }
2236 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
2237 obj->z_nodelete) && !obj->ref_nodel) {
2238 dbg("obj %s nodelete", obj->path);
2239 ref_dag(obj);
2240 obj->z_nodelete = obj->ref_nodel = true;
2241 }
984263bc
MD
2242 }
2243
fcf53d9b
JM
2244 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
2245 name);
984263bc
MD
2246 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
2247
fcf53d9b
JM
2248 /* Call the init functions. */
2249 objlist_call_init(&initlist, &lockstate);
984263bc 2250 objlist_clear(&initlist);
fcf53d9b 2251 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2252 return obj;
2253trace:
2254 trace_loaded_objects(obj);
fcf53d9b 2255 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2256 exit(0);
2257}
2258
fcf53d9b
JM
2259static void *
2260do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
2261 int flags)
984263bc 2262{
fcf53d9b
JM
2263 DoneList donelist;
2264 const Obj_Entry *obj, *defobj;
2265 const Elf_Sym *def, *symp;
984263bc 2266 unsigned long hash;
fcf53d9b 2267 RtldLockState lockstate;
984263bc
MD
2268
2269 hash = elf_hash(name);
2270 def = NULL;
2271 defobj = NULL;
fcf53d9b 2272 flags |= SYMLOOK_IN_PLT;
984263bc 2273
fcf53d9b
JM
2274 rlock_acquire(rtld_bind_lock, &lockstate);
2275 if (sigsetjmp(lockstate.env, 0) != 0)
2276 lock_upgrade(rtld_bind_lock, &lockstate);
984263bc
MD
2277 if (handle == NULL || handle == RTLD_NEXT ||
2278 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
984263bc 2279
984263bc
MD
2280 if ((obj = obj_from_addr(retaddr)) == NULL) {
2281 _rtld_error("Cannot determine caller's shared object");
fcf53d9b 2282 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2283 return NULL;
2284 }
2285 if (handle == NULL) { /* Just the caller's shared object. */
fcf53d9b 2286 def = symlook_obj(name, hash, obj, ve, flags);
984263bc
MD
2287 defobj = obj;
2288 } else if (handle == RTLD_NEXT || /* Objects after caller's */
2289 handle == RTLD_SELF) { /* ... caller included */
2290 if (handle == RTLD_NEXT)
2291 obj = obj->next;
2292 for (; obj != NULL; obj = obj->next) {
fcf53d9b
JM
2293 if ((symp = symlook_obj(name, hash, obj, ve, flags)) != NULL) {
2294 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2295 def = symp;
2296 defobj = obj;
2297 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2298 break;
2299 }
2300 }
2301 }
2302 /*
2303 * Search the dynamic linker itself, and possibly resolve the
2304 * symbol from there. This is how the application links to
2305 * dynamic linker services such as dlopen.
2306 */
2307 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2308 symp = symlook_obj(name, hash, &obj_rtld, ve, flags);
2309 if (symp != NULL) {
2310 def = symp;
2311 defobj = &obj_rtld;
984263bc
MD
2312 }
2313 }
2314 } else {
2315 assert(handle == RTLD_DEFAULT);
fcf53d9b 2316 def = symlook_default(name, hash, obj, &defobj, ve, flags);
984263bc
MD
2317 }
2318 } else {
2319 if ((obj = dlcheck(handle)) == NULL) {
fcf53d9b 2320 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2321 return NULL;
2322 }
2323
fb0c631e 2324 donelist_init(&donelist);
984263bc 2325 if (obj->mainprog) {
984263bc 2326 /* Search main program and all libraries loaded by it. */
fcf53d9b
JM
2327 def = symlook_list(name, hash, &list_main, &defobj, ve, flags,
2328 &donelist);
2329
2330 /*
2331 * We do not distinguish between 'main' object and global scope.
2332 * If symbol is not defined by objects loaded at startup, continue
2333 * search among dynamically loaded objects with RTLD_GLOBAL
2334 * scope.
2335 */
2336 if (def == NULL)
2337 def = symlook_list(name, hash, &list_global, &defobj, ve,
2338 flags, &donelist);
984263bc 2339 } else {
cebaf0af
SS
2340 Needed_Entry fake;
2341
fcf53d9b 2342 /* Search the whole DAG rooted at the given object. */
cebaf0af
SS
2343 fake.next = NULL;
2344 fake.obj = (Obj_Entry *)obj;
2345 fake.name = 0;
fcf53d9b
JM
2346 def = symlook_needed(name, hash, &fake, &defobj, ve, flags,
2347 &donelist);
984263bc
MD
2348 }
2349 }
2350
2351 if (def != NULL) {
fcf53d9b
JM
2352 lock_release(rtld_bind_lock, &lockstate);
2353
2354 /*
2355 * The value required by the caller is derived from the value
2356 * of the symbol. For the ia64 architecture, we need to
2357 * construct a function descriptor which the caller can use to
2358 * call the function with the right 'gp' value. For other
2359 * architectures and for non-functions, the value is simply
2360 * the relocated value of the symbol.
2361 */
2362 if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
0c151ba0 2363 return (make_function_pointer(def, defobj));
fcf53d9b 2364 else
0c151ba0 2365 return (defobj->relocbase + def->st_value);
984263bc
MD
2366 }
2367
2368 _rtld_error("Undefined symbol \"%s\"", name);
fcf53d9b 2369 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2370 return NULL;
2371}
2372
fcf53d9b
JM
2373void *
2374dlsym(void *handle, const char *name)
2375{
2376 return do_dlsym(handle, name, __builtin_return_address(0), NULL,
2377 SYMLOOK_DLSYM);
2378}
2379
2380dlfunc_t
2381dlfunc(void *handle, const char *name)
2382{
2383 union {
2384 void *d;
2385 dlfunc_t f;
2386 } rv;
2387
2388 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
2389 SYMLOOK_DLSYM);
2390 return (rv.f);
2391}
2392
2393void *
2394dlvsym(void *handle, const char *name, const char *version)
2395{
2396 Ver_Entry ventry;
2397
2398 ventry.name = version;
2399 ventry.file = NULL;
2400 ventry.hash = elf_hash(version);
2401 ventry.flags= 0;
2402 return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
2403 SYMLOOK_DLSYM);
2404}
2405
2406int
2407_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
2408{
2409 const Obj_Entry *obj;
2410 RtldLockState lockstate;
2411
2412 rlock_acquire(rtld_bind_lock, &lockstate);
2413 obj = obj_from_addr(addr);
2414 if (obj == NULL) {
2415 _rtld_error("No shared object contains address");
2416 lock_release(rtld_bind_lock, &lockstate);
2417 return (0);
2418 }
2419 rtld_fill_dl_phdr_info(obj, phdr_info);
2420 lock_release(rtld_bind_lock, &lockstate);
2421 return (1);
2422}
2423
984263bc
MD
2424int
2425dladdr(const void *addr, Dl_info *info)
2426{
2427 const Obj_Entry *obj;
2428 const Elf_Sym *def;
2429 void *symbol_addr;
2430 unsigned long symoffset;
fcf53d9b
JM
2431 RtldLockState lockstate;
2432
2433 rlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2434 obj = obj_from_addr(addr);
2435 if (obj == NULL) {
2436 _rtld_error("No shared object contains address");
fcf53d9b 2437 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2438 return 0;
2439 }
2440 info->dli_fname = obj->path;
2441 info->dli_fbase = obj->mapbase;
60233e58 2442 info->dli_saddr = NULL;
984263bc
MD
2443 info->dli_sname = NULL;
2444
2445 /*
2446 * Walk the symbol list looking for the symbol whose address is
2447 * closest to the address sent in.
2448 */
2449 for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
2450 def = obj->symtab + symoffset;
2451
2452 /*
2453 * For skip the symbol if st_shndx is either SHN_UNDEF or
2454 * SHN_COMMON.
2455 */
2456 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
2457 continue;
2458
2459 /*
2460 * If the symbol is greater than the specified address, or if it
2461 * is further away from addr than the current nearest symbol,
2462 * then reject it.
2463 */
2464 symbol_addr = obj->relocbase + def->st_value;
2465 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
2466 continue;
2467
2468 /* Update our idea of the nearest symbol. */
2469 info->dli_sname = obj->strtab + def->st_name;
2470 info->dli_saddr = symbol_addr;
2471
2472 /* Exact match? */
2473 if (info->dli_saddr == addr)
2474 break;
2475 }
fcf53d9b 2476 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2477 return 1;
2478}
2479
2480int
2481dlinfo(void *handle, int request, void *p)
2482{
2483 const Obj_Entry *obj;
fcf53d9b 2484 RtldLockState lockstate;
984263bc
MD
2485 int error;
2486
fcf53d9b 2487 rlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2488
2489 if (handle == NULL || handle == RTLD_SELF) {
2490 void *retaddr;
2491
2492 retaddr = __builtin_return_address(0); /* __GNUC__ only */
2493 if ((obj = obj_from_addr(retaddr)) == NULL)
2494 _rtld_error("Cannot determine caller's shared object");
2495 } else
2496 obj = dlcheck(handle);
2497
2498 if (obj == NULL) {
fcf53d9b 2499 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2500 return (-1);
2501 }
2502
2503 error = 0;
2504 switch (request) {
2505 case RTLD_DI_LINKMAP:
2506 *((struct link_map const **)p) = &obj->linkmap;
2507 break;
2508 case RTLD_DI_ORIGIN:
2509 error = rtld_dirname(obj->path, p);
2510 break;
2511
2512 case RTLD_DI_SERINFOSIZE:
2513 case RTLD_DI_SERINFO:
2514 error = do_search_info(obj, request, (struct dl_serinfo *)p);
2515 break;
2516
2517 default:
2518 _rtld_error("Invalid request %d passed to dlinfo()", request);
2519 error = -1;
2520 }
2521
fcf53d9b
JM
2522 lock_release(rtld_bind_lock, &lockstate);
2523
2524 return (error);
2525}
2526
2527static void
2528rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
2529{
2530
2531 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
2532 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ?
2533 STAILQ_FIRST(&obj->names)->name : obj->path;
2534 phdr_info->dlpi_phdr = obj->phdr;
2535 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
2536 phdr_info->dlpi_tls_modid = obj->tlsindex;
2537 phdr_info->dlpi_tls_data = obj->tlsinit;
2538 phdr_info->dlpi_adds = obj_loads;
2539 phdr_info->dlpi_subs = obj_loads - obj_count;
2540}
2541
2542int
2543dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
2544{
2545 struct dl_phdr_info phdr_info;
2546 const Obj_Entry *obj;
2547 RtldLockState bind_lockstate, phdr_lockstate;
2548 int error;
2549
2550 wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
2551 rlock_acquire(rtld_bind_lock, &bind_lockstate);
2552
2553 error = 0;
2554
2555 for (obj = obj_list; obj != NULL; obj = obj->next) {
2556 rtld_fill_dl_phdr_info(obj, &phdr_info);
2557 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0)
2558 break;
2559
2560 }
2561 lock_release(rtld_bind_lock, &bind_lockstate);
2562 lock_release(rtld_phdr_lock, &phdr_lockstate);
984263bc
MD
2563
2564 return (error);
2565}
2566
2567struct fill_search_info_args {
2568 int request;
2569 unsigned int flags;
2570 Dl_serinfo *serinfo;
2571 Dl_serpath *serpath;
2572 char *strspace;
2573};
2574
2575static void *
2576fill_search_info(const char *dir, size_t dirlen, void *param)
2577{
2578 struct fill_search_info_args *arg;
2579
2580 arg = param;
2581
2582 if (arg->request == RTLD_DI_SERINFOSIZE) {
2583 arg->serinfo->dls_cnt ++;
fcf53d9b 2584 arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1;
984263bc
MD
2585 } else {
2586 struct dl_serpath *s_entry;
2587
2588 s_entry = arg->serpath;
2589 s_entry->dls_name = arg->strspace;
2590 s_entry->dls_flags = arg->flags;
2591
2592 strncpy(arg->strspace, dir, dirlen);
2593 arg->strspace[dirlen] = '\0';
2594
2595 arg->strspace += dirlen + 1;
2596 arg->serpath++;
2597 }
2598
2599 return (NULL);
2600}
2601
2602static int
2603do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
2604{
2605 struct dl_serinfo _info;
2606 struct fill_search_info_args args;
2607
2608 args.request = RTLD_DI_SERINFOSIZE;
2609 args.serinfo = &_info;
2610
2611 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2612 _info.dls_cnt = 0;
2613
2614 path_enumerate(ld_library_path, fill_search_info, &args);
2615 path_enumerate(obj->rpath, fill_search_info, &args);
2616 path_enumerate(gethints(), fill_search_info, &args);
2617 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
2618
2619
2620 if (request == RTLD_DI_SERINFOSIZE) {
2621 info->dls_size = _info.dls_size;
2622 info->dls_cnt = _info.dls_cnt;
2623 return (0);
2624 }
2625
2626 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
2627 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
2628 return (-1);
2629 }
2630
2631 args.request = RTLD_DI_SERINFO;
2632 args.serinfo = info;
2633 args.serpath = &info->dls_serpath[0];
2634 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
2635
2636 args.flags = LA_SER_LIBPATH;
2637 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
2638 return (-1);
2639
2640 args.flags = LA_SER_RUNPATH;
2641 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
2642 return (-1);
2643
2644 args.flags = LA_SER_CONFIG;
2645 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
2646 return (-1);
2647
2648 args.flags = LA_SER_DEFAULT;
2649 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
2650 return (-1);
2651 return (0);
2652}
2653
2654static int
2655rtld_dirname(const char *path, char *bname)
2656{
2657 const char *endp;
2658
2659 /* Empty or NULL string gets treated as "." */
2660 if (path == NULL || *path == '\0') {
2661 bname[0] = '.';
2662 bname[1] = '\0';
2663 return (0);
2664 }
2665
2666 /* Strip trailing slashes */
2667 endp = path + strlen(path) - 1;
2668 while (endp > path && *endp == '/')
2669 endp--;
2670
2671 /* Find the start of the dir */
2672 while (endp > path && *endp != '/')
2673 endp--;
2674
2675 /* Either the dir is "/" or there are no slashes */
2676 if (endp == path) {
2677 bname[0] = *endp == '/' ? '/' : '.';
2678 bname[1] = '\0';
2679 return (0);
2680 } else {
2681 do {
2682 endp--;
2683 } while (endp > path && *endp == '/');
2684 }
2685
2686 if (endp - path + 2 > PATH_MAX)
2687 {
2688 _rtld_error("Filename is too long: %s", path);
2689 return(-1);
2690 }
2691
2692 strncpy(bname, path, endp - path + 1);
2693 bname[endp - path + 1] = '\0';
2694 return (0);
2695}
2696
fcf53d9b
JM
2697static int
2698rtld_dirname_abs(const char *path, char *base)
2699{
2700 char base_rel[PATH_MAX];
2701
2702 if (rtld_dirname(path, base) == -1)
2703 return (-1);
2704 if (base[0] == '/')
2705 return (0);
2706 if (getcwd(base_rel, sizeof(base_rel)) == NULL ||
2707 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) ||
2708 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel))
2709 return (-1);
2710 strcpy(base, base_rel);
2711 return (0);
2712}
2713
984263bc
MD
2714static void
2715linkmap_add(Obj_Entry *obj)
2716{
2717 struct link_map *l = &obj->linkmap;
2718 struct link_map *prev;
2719
2720 obj->linkmap.l_name = obj->path;
2721 obj->linkmap.l_addr = obj->mapbase;
2722 obj->linkmap.l_ld = obj->dynamic;
2723#ifdef __mips__
2724 /* GDB needs load offset on MIPS to use the symbols */
2725 obj->linkmap.l_offs = obj->relocbase;
2726#endif
2727
2728 if (r_debug.r_map == NULL) {
2729 r_debug.r_map = l;
2730 return;
2731 }
2732
2733 /*
2734 * Scan to the end of the list, but not past the entry for the
2735 * dynamic linker, which we want to keep at the very end.
2736 */
2737 for (prev = r_debug.r_map;
2738 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
2739 prev = prev->l_next)
2740 ;
2741
2742 /* Link in the new entry. */
2743 l->l_prev = prev;
2744 l->l_next = prev->l_next;
2745 if (l->l_next != NULL)
2746 l->l_next->l_prev = l;
2747 prev->l_next = l;
2748}
2749
2750static void
2751linkmap_delete(Obj_Entry *obj)
2752{
2753 struct link_map *l = &obj->linkmap;
2754
2755 if (l->l_prev == NULL) {
2756 if ((r_debug.r_map = l->l_next) != NULL)
2757 l->l_next->l_prev = NULL;
2758 return;
2759 }
2760
2761 if ((l->l_prev->l_next = l->l_next) != NULL)
2762 l->l_next->l_prev = l->l_prev;
2763}
2764
2765/*
2766 * Function for the debugger to set a breakpoint on to gain control.
2767 *
2768 * The two parameters allow the debugger to easily find and determine
2769 * what the runtime loader is doing and to whom it is doing it.
2770 *
2771 * When the loadhook trap is hit (r_debug_state, set at program
2772 * initialization), the arguments can be found on the stack:
2773 *
2774 * +8 struct link_map *m
2775 * +4 struct r_debug *rd
2776 * +0 RetAddr
2777 */
2778void
2779r_debug_state(struct r_debug* rd, struct link_map *m)
2780{
8301820e
JM
2781 /*
2782 * The following is a hack to force the compiler to emit calls to
2783 * this function, even when optimizing. If the function is empty,
2784 * the compiler is not obliged to emit any code for calls to it,
2785 * even when marked __noinline. However, gdb depends on those
2786 * calls being made.
2787 */
2788 __asm __volatile("" : : : "memory");
984263bc
MD
2789}
2790
2791/*
2792 * Get address of the pointer variable in the main program.
2793 */
2794static const void **
2795get_program_var_addr(const char *name)
2796{
2797 const Obj_Entry *obj;
2798 unsigned long hash;
2799
2800 hash = elf_hash(name);
2801 for (obj = obj_main; obj != NULL; obj = obj->next) {
2802 const Elf_Sym *def;
2803
fcf53d9b 2804 if ((def = symlook_obj(name, hash, obj, NULL, 0)) != NULL) {
984263bc
MD
2805 const void **addr;
2806
2807 addr = (const void **)(obj->relocbase + def->st_value);
2808 return addr;
2809 }
2810 }
fcf53d9b 2811 return (NULL);
984263bc
MD
2812}
2813
2814/*
2815 * Set a pointer variable in the main program to the given value. This
2816 * is used to set key variables such as "environ" before any of the
2817 * init functions are called.
2818 */
2819static void
2820set_program_var(const char *name, const void *value)
2821{
2822 const void **addr;
2823
2824 if ((addr = get_program_var_addr(name)) != NULL) {
2825 dbg("\"%s\": *%p <-- %p", name, addr, value);
2826 *addr = value;
2827 }
2828}
2829
8ca15ec8
MD
2830/*
2831 * This is a special version of getenv which is far more efficient
2832 * at finding LD_ environment vars.
2833 */
2834static
2835const char *
2836_getenv_ld(const char *id)
2837{
2838 const char *envp;
2839 int i, j;
2840 int idlen = strlen(id);
2841
2842 if (ld_index == LD_ARY_CACHE)
2843 return(getenv(id));
2844 if (ld_index == 0) {
2845 for (i = j = 0; (envp = environ[i]) != NULL && j < LD_ARY_CACHE; ++i) {
2846 if (envp[0] == 'L' && envp[1] == 'D' && envp[2] == '_')
2847 ld_ary[j++] = envp;
2848 }
2849 if (j == 0)
2850 ld_ary[j++] = "";
2851 ld_index = j;
2852 }
2853 for (i = ld_index - 1; i >= 0; --i) {
2854 if (strncmp(ld_ary[i], id, idlen) == 0 && ld_ary[i][idlen] == '=')
2855 return(ld_ary[i] + idlen + 1);
2856 }
2857 return(NULL);
2858}
2859
984263bc
MD
2860/*
2861 * Given a symbol name in a referencing object, find the corresponding
2862 * definition of the symbol. Returns a pointer to the symbol, or NULL if
2863 * no definition was found. Returns a pointer to the Obj_Entry of the
2864 * defining object via the reference parameter DEFOBJ_OUT.
2865 */
2866static const Elf_Sym *
fcf53d9b
JM
2867symlook_default(const char *name, unsigned long hash, const Obj_Entry *refobj,
2868 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags)
984263bc
MD
2869{
2870 DoneList donelist;
2871 const Elf_Sym *def;
2872 const Elf_Sym *symp;
2873 const Obj_Entry *obj;
2874 const Obj_Entry *defobj;
2875 const Objlist_Entry *elm;
2876 def = NULL;
2877 defobj = NULL;
2878 donelist_init(&donelist);
2879
2880 /* Look first in the referencing object if linked symbolically. */
2881 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
fcf53d9b 2882 symp = symlook_obj(name, hash, refobj, ventry, flags);
984263bc
MD
2883 if (symp != NULL) {
2884 def = symp;
2885 defobj = refobj;
2886 }
2887 }
2888
2889 /* Search all objects loaded at program start up. */
2890 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
fcf53d9b
JM
2891 symp = symlook_list(name, hash, &list_main, &obj, ventry, flags,
2892 &donelist);
984263bc
MD
2893 if (symp != NULL &&
2894 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2895 def = symp;
2896 defobj = obj;
2897 }
2898 }
2899
2900 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
2901 STAILQ_FOREACH(elm, &list_global, link) {
2902 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2903 break;
fcf53d9b
JM
2904 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry,
2905 flags, &donelist);
984263bc
MD
2906 if (symp != NULL &&
2907 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2908 def = symp;
2909 defobj = obj;
2910 }
2911 }
2912
2913 /* Search all dlopened DAGs containing the referencing object. */
2914 STAILQ_FOREACH(elm, &refobj->dldags, link) {
2915 if (def != NULL && ELF_ST_BIND(def->st_info) != STB_WEAK)
2916 break;
fcf53d9b
JM
2917 symp = symlook_list(name, hash, &elm->obj->dagmembers, &obj, ventry,
2918 flags, &donelist);
984263bc
MD
2919 if (symp != NULL &&
2920 (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK)) {
2921 def = symp;
2922 defobj = obj;
2923 }
2924 }
2925
2926 /*
2927 * Search the dynamic linker itself, and possibly resolve the
2928 * symbol from there. This is how the application links to
2929 * dynamic linker services such as dlopen. Only the values listed
2930 * in the "exports" array can be resolved from the dynamic linker.
2931 */
2932 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
fcf53d9b 2933 symp = symlook_obj(name, hash, &obj_rtld, ventry, flags);
984263bc
MD
2934 if (symp != NULL && is_exported(symp)) {
2935 def = symp;
2936 defobj = &obj_rtld;
2937 }
2938 }
2939
2940 if (def != NULL)
2941 *defobj_out = defobj;
2942 return def;
2943}
2944
2945static const Elf_Sym *
fb0c631e 2946symlook_list(const char *name, unsigned long hash, const Objlist *objlist,
fcf53d9b
JM
2947 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags,
2948 DoneList *dlp)
984263bc
MD
2949{
2950 const Elf_Sym *symp;
2951 const Elf_Sym *def;
2952 const Obj_Entry *defobj;
2953 const Objlist_Entry *elm;
2954
2955 def = NULL;
2956 defobj = NULL;
2957 STAILQ_FOREACH(elm, objlist, link) {
2958 if (donelist_check(dlp, elm->obj))
2959 continue;
fcf53d9b 2960 if ((symp = symlook_obj(name, hash, elm->obj, ventry, flags)) != NULL) {
984263bc
MD
2961 if (def == NULL || ELF_ST_BIND(symp->st_info) != STB_WEAK) {
2962 def = symp;
2963 defobj = elm->obj;
2964 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2965 break;
2966 }
2967 }
2968 }
2969 if (def != NULL)
2970 *defobj_out = defobj;
2971 return def;
2972}
2973
cebaf0af
SS
2974/*
2975 * Search the symbol table of a shared object and all objects needed
2976 * by it for a symbol of the given name. Search order is
2977 * breadth-first. Returns a pointer to the symbol, or NULL if no
2978 * definition was found.
2979 */
2980static const Elf_Sym *
2981symlook_needed(const char *name, unsigned long hash, const Needed_Entry *needed,
fcf53d9b
JM
2982 const Obj_Entry **defobj_out, const Ver_Entry *ventry, int flags,
2983 DoneList *dlp)
cebaf0af
SS
2984{
2985 const Elf_Sym *def, *def_w;
2986 const Needed_Entry *n;
2987 const Obj_Entry *obj, *defobj, *defobj1;
fcf53d9b 2988
cebaf0af
SS
2989 def = def_w = NULL;
2990 defobj = NULL;
2991 for (n = needed; n != NULL; n = n->next) {
fcf53d9b
JM
2992 if ((obj = n->obj) == NULL ||
2993 donelist_check(dlp, obj) ||
2994 (def = symlook_obj(name, hash, obj, ventry, flags)) == NULL)
2995 continue;
2996 defobj = obj;
2997 if (ELF_ST_BIND(def->st_info) != STB_WEAK) {
2998 *defobj_out = defobj;
2999 return (def);
cebaf0af
SS
3000 }
3001 }
3002 /*
3003 * There we come when either symbol definition is not found in
3004 * directly needed objects, or found symbol is weak.
3005 */
3006 for (n = needed; n != NULL; n = n->next) {
fcf53d9b
JM
3007 if ((obj = n->obj) == NULL)
3008 continue;
3009 def_w = symlook_needed(name, hash, obj->needed, &defobj1,
3010 ventry, flags, dlp);
3011 if (def_w == NULL)
3012 continue;
3013 if (def == NULL || ELF_ST_BIND(def_w->st_info) != STB_WEAK) {
3014 def = def_w;
3015 defobj = defobj1;
3016 }
3017 if (ELF_ST_BIND(def_w->st_info) != STB_WEAK)
3018 break;
cebaf0af
SS
3019 }
3020 if (def != NULL)
fcf53d9b
JM
3021 *defobj_out = defobj;
3022 return (def);
cebaf0af
SS
3023}
3024
984263bc
MD
3025/*
3026 * Search the symbol table of a single shared object for a symbol of
fcf53d9b
JM
3027 * the given name and version, if requested. Returns a pointer to the
3028 * symbol, or NULL if no definition was found.
984263bc
MD
3029 *
3030 * The symbol's hash value is passed in for efficiency reasons; that
3031 * eliminates many recomputations of the hash value.
3032 */
3033const Elf_Sym *
3034symlook_obj(const char *name, unsigned long hash, const Obj_Entry *obj,
fcf53d9b 3035 const Ver_Entry *ventry, int flags)
984263bc 3036{
fcf53d9b
JM
3037 unsigned long symnum;
3038 const Elf_Sym *vsymp;
3039 Elf_Versym verndx;
3040 int vcount;
984263bc 3041
fcf53d9b
JM
3042 if (obj->buckets == NULL)
3043 return NULL;
984263bc 3044
fcf53d9b
JM
3045 vsymp = NULL;
3046 vcount = 0;
3047 symnum = obj->buckets[hash % obj->nbuckets];
3048
3049 for (; symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
3050 const Elf_Sym *symp;
3051 const char *strp;
3052
3053 if (symnum >= obj->nchains)
3054 return NULL; /* Bad object */
3055
3056 symp = obj->symtab + symnum;
3057 strp = obj->strtab + symp->st_name;
3058
3059 switch (ELF_ST_TYPE(symp->st_info)) {
3060 case STT_FUNC:
3061 case STT_NOTYPE:
3062 case STT_OBJECT:
3063 if (symp->st_value == 0)
3064 continue;
3065 /* fallthrough */
3066 case STT_TLS:
3067 if (symp->st_shndx != SHN_UNDEF)
3068 break;
3069 else if (((flags & SYMLOOK_IN_PLT) == 0) &&
3070 (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
3071 break;
3072 /* fallthrough */
3073 default:
3074 continue;
3075 }
3076 if (name[0] != strp[0] || strcmp(name, strp) != 0)
3077 continue;
984263bc 3078
fcf53d9b
JM
3079 if (ventry == NULL) {
3080 if (obj->versyms != NULL) {
3081 verndx = VER_NDX(obj->versyms[symnum]);
3082 if (verndx > obj->vernum) {
3083 _rtld_error("%s: symbol %s references wrong version %d",
3084 obj->path, obj->strtab + symnum, verndx);
3085 continue;
3086 }
3087 /*
3088 * If we are not called from dlsym (i.e. this is a normal
3089 * relocation from unversioned binary), accept the symbol
3090 * immediately if it happens to have first version after
3091 * this shared object became versioned. Otherwise, if
3092 * symbol is versioned and not hidden, remember it. If it
3093 * is the only symbol with this name exported by the
3094 * shared object, it will be returned as a match at the
3095 * end of the function. If symbol is global (verndx < 2)
3096 * accept it unconditionally.
3097 */
3098 if ((flags & SYMLOOK_DLSYM) == 0 && verndx == VER_NDX_GIVEN)
3099 return symp;
3100 else if (verndx >= VER_NDX_GIVEN) {
3101 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) {
3102 if (vsymp == NULL)
3103 vsymp = symp;
3104 vcount ++;
3105 }
3106 continue;
3107 }
3108 }
3109 return symp;
3110 } else {
3111 if (obj->versyms == NULL) {
3112 if (object_match_name(obj, ventry->name)) {
3113 _rtld_error("%s: object %s should provide version %s for "
3114 "symbol %s", obj_rtld.path, obj->path, ventry->name,
3115 obj->strtab + symnum);
3116 continue;
3117 }
3118 } else {
3119 verndx = VER_NDX(obj->versyms[symnum]);
3120 if (verndx > obj->vernum) {
3121 _rtld_error("%s: symbol %s references wrong version %d",
3122 obj->path, obj->strtab + symnum, verndx);
3123 continue;
3124 }
3125 if (obj->vertab[verndx].hash != ventry->hash ||
3126 strcmp(obj->vertab[verndx].name, ventry->name)) {
3127 /*
3128 * Version does not match. Look if this is a global symbol
3129 * and if it is not hidden. If global symbol (verndx < 2)
3130 * is available, use it. Do not return symbol if we are
3131 * called by dlvsym, because dlvsym looks for a specific
3132 * version and default one is not what dlvsym wants.
3133 */
3134 if ((flags & SYMLOOK_DLSYM) ||
3135 (obj->versyms[symnum] & VER_NDX_HIDDEN) ||
3136 (verndx >= VER_NDX_GIVEN))
3137 continue;
3138 }
3139 }
3140 return symp;
984263bc
MD
3141 }
3142 }
fcf53d9b 3143 return (vcount == 1) ? vsymp : NULL;
984263bc
MD
3144}
3145
3146static void
3147trace_loaded_objects(Obj_Entry *obj)
3148{
fcf53d9b 3149 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers;
984263bc
MD
3150 int c;
3151
8ca15ec8 3152 if ((main_local = _getenv_ld("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
984263bc
MD
3153 main_local = "";
3154
8ca15ec8 3155 if ((fmt1 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL)
984263bc
MD
3156 fmt1 = "\t%o => %p (%x)\n";
3157
8ca15ec8 3158 if ((fmt2 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL)
984263bc
MD
3159 fmt2 = "\t%o (%x)\n";
3160
fcf53d9b
JM
3161 list_containers = _getenv_ld("LD_TRACE_LOADED_OBJECTS_ALL");
3162
984263bc
MD
3163 for (; obj; obj = obj->next) {
3164 Needed_Entry *needed;
3165 char *name, *path;
3166 bool is_lib;
3167
fcf53d9b 3168 if (list_containers && obj->needed != NULL)
abfcd5b1 3169 rtld_printf("%s:\n", obj->path);
984263bc
MD
3170 for (needed = obj->needed; needed; needed = needed->next) {
3171 if (needed->obj != NULL) {
fcf53d9b 3172 if (needed->obj->traced && !list_containers)
984263bc
MD
3173 continue;
3174 needed->obj->traced = true;
3175 path = needed->obj->path;
3176 } else
3177 path = "not found";
3178
3179 name = (char *)obj->strtab + needed->name;
3180 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
3181
3182 fmt = is_lib ? fmt1 : fmt2;
3183 while ((c = *fmt++) != '\0') {
3184 switch (c) {
3185 default:
abfcd5b1 3186 rtld_putchar(c);
984263bc
MD
3187 continue;
3188 case '\\':
3189 switch (c = *fmt) {
3190 case '\0':
3191 continue;
3192 case 'n':
abfcd5b1 3193 rtld_putchar('\n');
984263bc
MD
3194 break;
3195 case 't':
abfcd5b1 3196 rtld_putchar('\t');
984263bc
MD
3197 break;
3198 }
3199 break;
3200 case '%':
3201 switch (c = *fmt) {
3202 case '\0':
3203 continue;
3204 case '%':
3205 default:
abfcd5b1 3206 rtld_putchar(c);
984263bc
MD
3207 break;
3208 case 'A':
abfcd5b1 3209 rtld_putstr(main_local);
984263bc
MD
3210 break;
3211 case 'a':
abfcd5b1 3212 rtld_putstr(obj_main->path);
984263bc
MD
3213 break;
3214 case 'o':
abfcd5b1 3215 rtld_putstr(name);
984263bc 3216 break;
984263bc 3217 case 'p':
abfcd5b1 3218 rtld_putstr(path);
984263bc
MD
3219 break;
3220 case 'x':
abfcd5b1
JM
3221 rtld_printf("%p", needed->obj ? needed->obj->mapbase :
3222 0);
984263bc
MD
3223 break;
3224 }
3225 break;
3226 }
3227 ++fmt;
3228 }
3229 }
3230 }
3231}
3232
3233/*
3234 * Unload a dlopened object and its dependencies from memory and from
3235 * our data structures. It is assumed that the DAG rooted in the
3236 * object has already been unreferenced, and that the object has a
3237 * reference count of 0.
3238 */
3239static void
3240unload_object(Obj_Entry *root)
3241{
3242 Obj_Entry *obj;
3243 Obj_Entry **linkp;
3244
3245 assert(root->refcount == 0);
3246
3247 /*
3248 * Pass over the DAG removing unreferenced objects from
3249 * appropriate lists.
fcf53d9b 3250 */
984263bc
MD
3251 unlink_object(root);
3252
3253 /* Unmap all objects that are no longer referenced. */
3254 linkp = &obj_list->next;
3255 while ((obj = *linkp) != NULL) {
3256 if (obj->refcount == 0) {
fcf53d9b
JM
3257 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
3258 obj->path);
984263bc
MD
3259 dbg("unloading \"%s\"", obj->path);
3260 munmap(obj->mapbase, obj->mapsize);
3261 linkmap_delete(obj);
3262 *linkp = obj->next;
3263 obj_count--;
3264 obj_free(obj);
3265 } else
3266 linkp = &obj->next;
3267 }
3268 obj_tail = linkp;
3269}
3270
3271static void
3272unlink_object(Obj_Entry *root)
3273{
984263bc
MD
3274 Objlist_Entry *elm;
3275
3276 if (root->refcount == 0) {
3277 /* Remove the object from the RTLD_GLOBAL list. */
3278 objlist_remove(&list_global, root);
3279
3280 /* Remove the object from all objects' DAG lists. */
fcf53d9b 3281 STAILQ_FOREACH(elm, &root->dagmembers, link) {
984263bc 3282 objlist_remove(&elm->obj->dldags, root);
fcf53d9b
JM
3283 if (elm->obj != root)
3284 unlink_object(elm->obj);
3285 }
984263bc 3286 }
fcf53d9b 3287}
984263bc 3288
fcf53d9b
JM
3289static void
3290ref_dag(Obj_Entry *root)
3291{
3292 Objlist_Entry *elm;
3293
3294 assert(root->dag_inited);
3295 STAILQ_FOREACH(elm, &root->dagmembers, link)
3296 elm->obj->refcount++;
984263bc
MD
3297}
3298
3299static void
3300unref_dag(Obj_Entry *root)
3301{
fcf53d9b 3302 Objlist_Entry *elm;
984263bc 3303
fcf53d9b
JM
3304 assert(root->dag_inited);
3305 STAILQ_FOREACH(elm, &root->dagmembers, link)
3306 elm->obj->refcount--;
984263bc 3307}
55b88cae
DX
3308
3309/*
3310 * Common code for MD __tls_get_addr().
3311 */
3312void *
fcf53d9b 3313tls_get_addr_common(Elf_Addr** dtvp, int index, size_t offset)
55b88cae
DX
3314{
3315 Elf_Addr* dtv = *dtvp;
fcf53d9b 3316 RtldLockState lockstate;
55b88cae
DX
3317
3318 /* Check dtv generation in case new modules have arrived */
3319 if (dtv[0] != tls_dtv_generation) {
3320 Elf_Addr* newdtv;
3321 int to_copy;
3322
fcf53d9b 3323 wlock_acquire(rtld_bind_lock, &lockstate);
55b88cae
DX
3324 newdtv = calloc(1, (tls_max_index + 2) * sizeof(Elf_Addr));
3325 to_copy = dtv[1];
3326 if (to_copy > tls_max_index)
3327 to_copy = tls_max_index;
3328 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
3329 newdtv[0] = tls_dtv_generation;
3330 newdtv[1] = tls_max_index;
3331 free(dtv);
fcf53d9b 3332 lock_release(rtld_bind_lock, &lockstate);
0c151ba0 3333 dtv = *dtvp = newdtv;
55b88cae
DX
3334 }
3335
3336 /* Dynamically allocate module TLS if necessary */
3337 if (!dtv[index + 1]) {
fcf53d9b
JM
3338 /* Signal safe, wlock will block out signals. */
3339 wlock_acquire(rtld_bind_lock, &lockstate);
3340 if (!dtv[index + 1])
55b88cae 3341 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
fcf53d9b 3342 lock_release(rtld_bind_lock, &lockstate);
55b88cae 3343 }
55b88cae
DX
3344 return (void*) (dtv[index + 1] + offset);
3345}
3346
9e2ee207 3347#if defined(RTLD_STATIC_TLS_VARIANT_II)
55b88cae
DX
3348
3349/*
bc633d63
MD
3350 * Allocate the static TLS area. Return a pointer to the TCB. The
3351 * static area is based on negative offsets relative to the tcb.
a1eee96a
MD
3352 *
3353 * The TCB contains an errno pointer for the system call layer, but because
3354 * we are the RTLD we really have no idea how the caller was compiled so
3355 * the information has to be passed in. errno can either be:
3356 *
3357 * type 0 errno is a simple non-TLS global pointer.
3358 * (special case for e.g. libc_rtld)
3359 * type 1 errno accessed by GOT entry (dynamically linked programs)
3360 * type 2 errno accessed by %gs:OFFSET (statically linked programs)
55b88cae 3361 */
bc633d63 3362struct tls_tcb *
a1eee96a 3363allocate_tls(Obj_Entry *objs)
55b88cae
DX
3364{
3365 Obj_Entry *obj;
bc633d63 3366 size_t data_size;
bc633d63
MD
3367 size_t dtv_size;
3368 struct tls_tcb *tcb;
a1eee96a 3369 Elf_Addr *dtv;
bc633d63 3370 Elf_Addr addr;
55b88cae 3371
bc633d63
MD
3372 /*
3373 * Allocate the new TCB. static TLS storage is placed just before the
3374 * TCB to support the %gs:OFFSET (negative offset) model.
3375 */
bc633d63
MD
3376 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
3377 ~RTLD_STATIC_TLS_ALIGN_MASK;
f20fd431 3378 tcb = malloc(data_size + sizeof(*tcb));
bc633d63 3379 tcb = (void *)((char *)tcb + data_size); /* actual tcb location */
55b88cae 3380
bc633d63
MD
3381 dtv_size = (tls_max_index + 2) * sizeof(Elf_Addr);
3382 dtv = malloc(dtv_size);
3383 bzero(dtv, dtv_size);
55b88cae 3384
9e2ee207
JS
3385#ifdef RTLD_TCB_HAS_SELF_POINTER
3386 tcb->tcb_self = tcb;
3387#endif
3388 tcb->tcb_dtv = dtv;
3389 tcb->tcb_pthread = NULL;
55b88cae
DX
3390
3391 dtv[0] = tls_dtv_generation;
3392 dtv[1] = tls_max_index;
3393
a1eee96a
MD
3394 for (obj = objs; obj; obj = obj->next) {
3395 if (obj->tlsoffset) {
3396 addr = (Elf_Addr)tcb - obj->tlsoffset;
3397 memset((void *)(addr + obj->tlsinitsize),
3398 0, obj->tlssize - obj->tlsinitsize);
3399 if (obj->tlsinit)
3400 memcpy((void*) addr, obj->tlsinit, obj->tlsinitsize);
3401 dtv[obj->tlsindex + 1] = addr;
55b88cae
DX
3402 }
3403 }
bc633d63 3404 return(tcb);
55b88cae
DX
3405}
3406
3407void
f20fd431 3408free_tls(struct tls_tcb *tcb)
bc633d63
MD
3409{
3410 Elf_Addr *dtv;
3411 int dtv_size, i;
3412 Elf_Addr tls_start, tls_end;
3413 size_t data_size;
3414
3415 data_size = (tls_static_space + RTLD_STATIC_TLS_ALIGN_MASK) &
3416 ~RTLD_STATIC_TLS_ALIGN_MASK;
fcf53d9b 3417
9e2ee207 3418 dtv = tcb->tcb_dtv;
bc633d63
MD
3419 dtv_size = dtv[1];
3420 tls_end = (Elf_Addr)tcb;
3421 tls_start = (Elf_Addr)tcb - data_size;
3422 for (i = 0; i < dtv_size; i++) {
eecd52b2 3423 if (dtv[i+2] != 0 && (dtv[i+2] < tls_start || dtv[i+2] > tls_end)) {
bc633d63 3424 free((void *)dtv[i+2]);
55b88cae
DX
3425 }
3426 }
fcf53d9b
JM
3427
3428 free((void*) tls_start);
55b88cae
DX
3429}
3430
9e2ee207
JS
3431#else
3432#error "Unsupported TLS layout"
55b88cae
DX
3433#endif
3434
3435/*
3436 * Allocate TLS block for module with given index.
3437 */
3438void *
3439allocate_module_tls(int index)
3440{
3441 Obj_Entry* obj;
3442 char* p;
3443
3444 for (obj = obj_list; obj; obj = obj->next) {
3445 if (obj->tlsindex == index)
3446 break;
3447 }
3448 if (!obj) {
3449 _rtld_error("Can't find module with TLS index %d", index);
3450 die();
3451 }
3452
3453 p = malloc(obj->tlssize);
fcf53d9b
JM
3454 if (p == NULL) {
3455 _rtld_error("Cannot allocate TLS block for index %d", index);
3456 die();
3457 }
55b88cae
DX
3458 memcpy(p, obj->tlsinit, obj->tlsinitsize);
3459 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
3460
3461 return p;
3462}
3463
3464bool
3465allocate_tls_offset(Obj_Entry *obj)
3466{
3467 size_t off;
3468
3469 if (obj->tls_done)
3470 return true;
3471
3472 if (obj->tlssize == 0) {
3473 obj->tls_done = true;
3474 return true;
3475 }
3476
3477 if (obj->tlsindex == 1)
3478 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign);
3479 else
3480 off = calculate_tls_offset(tls_last_offset, tls_last_size,
3481 obj->tlssize, obj->tlsalign);
3482
3483 /*
3484 * If we have already fixed the size of the static TLS block, we
3485 * must stay within that size. When allocating the static TLS, we
3486 * leave a small amount of space spare to be used for dynamically
3487 * loading modules which use static TLS.
3488 */
3489 if (tls_static_space) {
3490 if (calculate_tls_end(off, obj->tlssize) > tls_static_space)
3491 return false;
3492 }
3493
3494 tls_last_offset = obj->tlsoffset = off;
3495 tls_last_size = obj->tlssize;
3496 obj->tls_done = true;
3497
3498 return true;
3499}
3500
3501void
3502free_tls_offset(Obj_Entry *obj)
3503{
9e2ee207 3504#ifdef RTLD_STATIC_TLS_VARIANT_II
55b88cae
DX
3505 /*
3506 * If we were the last thing to allocate out of the static TLS
3507 * block, we give our space back to the 'allocator'. This is a
3508 * simplistic workaround to allow libGL.so.1 to be loaded and
3509 * unloaded multiple times. We only handle the Variant II
3510 * mechanism for now - this really needs a proper allocator.
3511 */
3512 if (calculate_tls_end(obj->tlsoffset, obj->tlssize)
3513 == calculate_tls_end(tls_last_offset, tls_last_size)) {
3514 tls_last_offset -= obj->tlssize;
3515 tls_last_size = 0;
3516 }
3517#endif
3518}
3519
bc633d63 3520struct tls_tcb *
a1eee96a 3521_rtld_allocate_tls(void)
55b88cae 3522{
bc633d63 3523 struct tls_tcb *new_tcb;
fcf53d9b 3524 RtldLockState lockstate;
55b88cae 3525
fcf53d9b 3526 wlock_acquire(rtld_bind_lock, &lockstate);
a1eee96a 3527 new_tcb = allocate_tls(obj_list);
fcf53d9b 3528 lock_release(rtld_bind_lock, &lockstate);
bc633d63 3529 return (new_tcb);
55b88cae
DX
3530}
3531
3532void
f20fd431 3533_rtld_free_tls(struct tls_tcb *tcb)
55b88cae 3534{
fcf53d9b
JM
3535 RtldLockState lockstate;
3536
3537 wlock_acquire(rtld_bind_lock, &lockstate);
f20fd431 3538 free_tls(tcb);
fcf53d9b
JM
3539 lock_release(rtld_bind_lock, &lockstate);
3540}
3541
3542static void
3543object_add_name(Obj_Entry *obj, const char *name)
3544{
3545 Name_Entry *entry;
3546 size_t len;
3547
3548 len = strlen(name);
3549 entry = malloc(sizeof(Name_Entry) + len);
3550
3551 if (entry != NULL) {
3552 strcpy(entry->name, name);
3553 STAILQ_INSERT_TAIL(&obj->names, entry, link);
3554 }
3555}
3556
3557static int
3558object_match_name(const Obj_Entry *obj, const char *name)
3559{
3560 Name_Entry *entry;
3561
3562 STAILQ_FOREACH(entry, &obj->names, link) {
3563 if (strcmp(name, entry->name) == 0)
3564 return (1);
3565 }
3566 return (0);
3567}
3568
3569static Obj_Entry *
3570locate_dependency(const Obj_Entry *obj, const char *name)
3571{
3572 const Objlist_Entry *entry;
3573 const Needed_Entry *needed;
3574
3575 STAILQ_FOREACH(entry, &list_main, link) {
3576 if (object_match_name(entry->obj, name))
3577 return entry->obj;
3578 }
3579
3580 for (needed = obj->needed; needed != NULL; needed = needed->next) {
3581 if (strcmp(obj->strtab + needed->name, name) == 0 ||
3582 (needed->obj != NULL && object_match_name(needed->obj, name))) {
3583 /*
3584 * If there is DT_NEEDED for the name we are looking for,
3585 * we are all set. Note that object might not be found if
3586 * dependency was not loaded yet, so the function can
3587 * return NULL here. This is expected and handled
3588 * properly by the caller.
3589 */
3590 return (needed->obj);
3591 }
3592 }
3593 _rtld_error("%s: Unexpected inconsistency: dependency %s not found",
3594 obj->path, name);
3595 die();
3596}
3597
3598static int
3599check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
3600 const Elf_Vernaux *vna)
3601{
3602 const Elf_Verdef *vd;
3603 const char *vername;
3604
3605 vername = refobj->strtab + vna->vna_name;
3606 vd = depobj->verdef;
3607 if (vd == NULL) {
3608 _rtld_error("%s: version %s required by %s not defined",
3609 depobj->path, vername, refobj->path);
3610 return (-1);
3611 }
3612 for (;;) {
3613 if (vd->vd_version != VER_DEF_CURRENT) {
3614 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
3615 depobj->path, vd->vd_version);
3616 return (-1);
3617 }
3618 if (vna->vna_hash == vd->vd_hash) {
3619 const Elf_Verdaux *aux = (const Elf_Verdaux *)
3620 ((char *)vd + vd->vd_aux);
3621 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
3622 return (0);
3623 }
3624 if (vd->vd_next == 0)
3625 break;
3626 vd = (const Elf_Verdef *) ((char *)vd + vd->vd_next);
3627 }
3628 if (vna->vna_flags & VER_FLG_WEAK)
3629 return (0);
3630 _rtld_error("%s: version %s required by %s not found",
3631 depobj->path, vername, refobj->path);
3632 return (-1);
55b88cae 3633}
bc633d63 3634
fcf53d9b
JM
3635static int
3636rtld_verify_object_versions(Obj_Entry *obj)
3637{
3638 const Elf_Verneed *vn;
3639 const Elf_Verdef *vd;
3640 const Elf_Verdaux *vda;
3641 const Elf_Vernaux *vna;
3642 const Obj_Entry *depobj;
3643 int maxvernum, vernum;
3644
3645 maxvernum = 0;
3646 /*
3647 * Walk over defined and required version records and figure out
3648 * max index used by any of them. Do very basic sanity checking
3649 * while there.
3650 */
3651 vn = obj->verneed;
3652 while (vn != NULL) {
3653 if (vn->vn_version != VER_NEED_CURRENT) {
3654 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
3655 obj->path, vn->vn_version);
3656 return (-1);
3657 }
3658 vna = (const Elf_Vernaux *) ((char *)vn + vn->vn_aux);
3659 for (;;) {
3660 vernum = VER_NEED_IDX(vna->vna_other);
3661 if (vernum > maxvernum)
3662 maxvernum = vernum;
3663 if (vna->vna_next == 0)
3664 break;
3665 vna = (const Elf_Vernaux *) ((char *)vna + vna->vna_next);
3666 }
3667 if (vn->vn_next == 0)
3668 break;
3669 vn = (const Elf_Verneed *) ((char *)vn + vn->vn_next);