Merge branch 'master' of git://git.dragonflybsd.org/dragonfly
[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
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75/*
76 * Function declarations.
77 */
8ca15ec8 78static const char *_getenv_ld(const char *id);
fcf53d9b 79static void die(void) __dead2;
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80static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
81 const Elf_Dyn **);
82static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *);
fcf53d9b 83static void digest_dynamic(Obj_Entry *, int);
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84static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
85static Obj_Entry *dlcheck(void *);
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86static Obj_Entry *dlopen_object(const char *name, Obj_Entry *refobj,
87 int lo_flags, int mode);
fcf53d9b 88static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
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89static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
90static bool donelist_check(DoneList *, const Obj_Entry *);
91static void errmsg_restore(char *);
92static char *errmsg_save(void);
93static void *fill_search_info(const char *, size_t, void *);
94static char *find_library(const char *, const Obj_Entry *);
95static const char *gethints(void);
96static void init_dag(Obj_Entry *);
b566341b 97static void init_rtld(caddr_t, Elf_Auxinfo **);
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98static void initlist_add_neededs(Needed_Entry *, Objlist *);
99static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
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100static bool is_exported(const Elf_Sym *);
101static void linkmap_add(Obj_Entry *);
102static void linkmap_delete(Obj_Entry *);
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103static void load_filtees(Obj_Entry *, int flags, RtldLockState *);
104static void unload_filtees(Obj_Entry *);
fcf53d9b 105static int load_needed_objects(Obj_Entry *, int);
984263bc 106static int load_preload_objects(void);
fcf53d9b 107static Obj_Entry *load_object(const char *, const Obj_Entry *, int);
e9de6dcc 108static void map_stacks_exec(RtldLockState *);
984263bc 109static Obj_Entry *obj_from_addr(const void *);
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110static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
111static void objlist_call_init(Objlist *, RtldLockState *);
b28bf640 112static void preinitialize_main_object (void);
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113static void objlist_clear(Objlist *);
114static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
115static void objlist_init(Objlist *);
116static void objlist_push_head(Objlist *, Obj_Entry *);
117static void objlist_push_tail(Objlist *, Obj_Entry *);
118static void objlist_remove(Objlist *, Obj_Entry *);
984263bc 119static void *path_enumerate(const char *, path_enum_proc, void *);
35b2b265 120static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, RtldLockState *);
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121static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now,
122 RtldLockState *lockstate);
984263bc 123static int rtld_dirname(const char *, char *);
fcf53d9b 124static int rtld_dirname_abs(const char *, char *);
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125static void rtld_exit(void);
126static char *search_library_path(const char *, const char *);
153ab392 127static const void **get_program_var_addr(const char *, RtldLockState *);
984263bc 128static void set_program_var(const char *, const void *);
35b2b265 129static int symlook_default(SymLook *, const Obj_Entry *refobj);
153ab392 130static int symlook_global(SymLook *, DoneList *);
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131static void symlook_init_from_req(SymLook *, const SymLook *);
132static int symlook_list(SymLook *, const Objlist *, DoneList *);
133static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *);
134static int symlook_obj1(SymLook *, const Obj_Entry *);
fcf53d9b 135static void trace_loaded_objects(Obj_Entry *);
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136static void unlink_object(Obj_Entry *);
137static void unload_object(Obj_Entry *);
138static void unref_dag(Obj_Entry *);
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139static void ref_dag(Obj_Entry *);
140static int origin_subst_one(char **, const char *, const char *,
141 const char *, char *);
142static char *origin_subst(const char *, const char *);
143static int rtld_verify_versions(const Objlist *);
144static int rtld_verify_object_versions(Obj_Entry *);
145static void object_add_name(Obj_Entry *, const char *);
146static int object_match_name(const Obj_Entry *, const char *);
147static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
148static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
149 struct dl_phdr_info *phdr_info);
150
8301820e 151void r_debug_state(struct r_debug *, struct link_map *) __noinline;
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152
153/*
154 * Data declarations.
155 */
156static char *error_message; /* Message for dlerror(), or NULL */
157struct r_debug r_debug; /* for GDB; */
fcf53d9b 158static bool libmap_disable; /* Disable libmap */
35b2b265 159static bool ld_loadfltr; /* Immediate filters processing */
fcf53d9b 160static char *libmap_override; /* Maps to use in addition to libmap.conf */
984263bc 161static bool trust; /* False for setuid and setgid programs */
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162static bool dangerous_ld_env; /* True if environment variables have been
163 used to affect the libraries loaded */
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164static const char *ld_bind_now; /* Environment variable for immediate binding */
165static const char *ld_debug; /* Environment variable for debugging */
166static const char *ld_library_path; /* Environment variable for search path */
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167static char *ld_preload; /* Environment variable for libraries to
168 load first */
fcf53d9b 169static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */
b566341b 170static const char *ld_tracing; /* Called from ldd to print libs */
fcf53d9b 171static const char *ld_utrace; /* Use utrace() to log events. */
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172static int (*rtld_functrace)( /* Optional function call tracing hook */
173 const char *caller_obj,
174 const char *callee_obj,
175 const char *callee_func,
176 void *stack);
35b2b265 177static const Obj_Entry *rtld_functrace_obj; /* Object thereof */
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178static Obj_Entry *obj_list; /* Head of linked list of shared objects */
179static Obj_Entry **obj_tail; /* Link field of last object in list */
8ca15ec8 180static Obj_Entry **preload_tail;
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181static Obj_Entry *obj_main; /* The main program shared object */
182static Obj_Entry obj_rtld; /* The dynamic linker shared object */
183static unsigned int obj_count; /* Number of objects in obj_list */
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184static unsigned int obj_loads; /* Number of objects in obj_list */
185
33a8b578 186static int ld_resident; /* Non-zero if resident */
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187static const char *ld_ary[LD_ARY_CACHE];
188static int ld_index;
a1eee96a 189static Objlist initlist;
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190
191static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
192 STAILQ_HEAD_INITIALIZER(list_global);
193static Objlist list_main = /* Objects loaded at program startup */
194 STAILQ_HEAD_INITIALIZER(list_main);
195static Objlist list_fini = /* Objects needing fini() calls */
196 STAILQ_HEAD_INITIALIZER(list_fini);
197
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198static Elf_Sym sym_zero; /* For resolving undefined weak refs. */
199
200#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
201
202extern Elf_Dyn _DYNAMIC;
203#pragma weak _DYNAMIC
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204#ifndef RTLD_IS_DYNAMIC
205#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL)
206#endif
984263bc 207
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208#ifdef ENABLE_OSRELDATE
209int osreldate;
210#endif
211
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212static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC;
213static int max_stack_flags;
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,
e9de6dcc 241 (func_ptr_type) &_rtld_get_stack_prot,
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242 NULL
243};
244
245/*
246 * Global declarations normally provided by crt1. The dynamic linker is
247 * not built with crt1, so we have to provide them ourselves.
248 */
249char *__progname;
250char **environ;
251
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252/*
253 * Globals passed as arguments to .init_array and .preinit_array functions
254 */
255
256int glac;
257char **glav;
258
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259/*
260 * Globals to control TLS allocation.
261 */
262size_t tls_last_offset; /* Static TLS offset of last module */
263size_t tls_last_size; /* Static TLS size of last module */
264size_t tls_static_space; /* Static TLS space allocated */
265int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
266int tls_max_index = 1; /* Largest module index allocated */
267
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268/*
269 * Fill in a DoneList with an allocation large enough to hold all of
270 * the currently-loaded objects. Keep this as a macro since it calls
271 * alloca and we want that to occur within the scope of the caller.
272 */
273#define donelist_init(dlp) \
274 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
275 assert((dlp)->objs != NULL), \
276 (dlp)->num_alloc = obj_count, \
277 (dlp)->num_used = 0)
278
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279#define UTRACE_DLOPEN_START 1
280#define UTRACE_DLOPEN_STOP 2
281#define UTRACE_DLCLOSE_START 3
282#define UTRACE_DLCLOSE_STOP 4
283#define UTRACE_LOAD_OBJECT 5
284#define UTRACE_UNLOAD_OBJECT 6
285#define UTRACE_ADD_RUNDEP 7
286#define UTRACE_PRELOAD_FINISHED 8
287#define UTRACE_INIT_CALL 9
288#define UTRACE_FINI_CALL 10
289
290struct utrace_rtld {
291 char sig[4]; /* 'RTLD' */
292 int event;
293 void *handle;
294 void *mapbase; /* Used for 'parent' and 'init/fini' */
295 size_t mapsize;
296 int refcnt; /* Used for 'mode' */
297 char name[MAXPATHLEN];
298};
984263bc 299
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300#define LD_UTRACE(e, h, mb, ms, r, n) do { \
301 if (ld_utrace != NULL) \
302 ld_utrace_log(e, h, mb, ms, r, n); \
303} while (0)
984263bc 304
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305static void
306ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
307 int refcnt, const char *name)
308{
309 struct utrace_rtld ut;
310
311 ut.sig[0] = 'R';
312 ut.sig[1] = 'T';
313 ut.sig[2] = 'L';
314 ut.sig[3] = 'D';
315 ut.event = event;
316 ut.handle = handle;
317 ut.mapbase = mapbase;
318 ut.mapsize = mapsize;
319 ut.refcnt = refcnt;
320 bzero(ut.name, sizeof(ut.name));
321 if (name)
322 strlcpy(ut.name, name, sizeof(ut.name));
323 utrace(&ut, sizeof(ut));
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324}
325
326/*
327 * Main entry point for dynamic linking. The first argument is the
328 * stack pointer. The stack is expected to be laid out as described
329 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
330 * Specifically, the stack pointer points to a word containing
331 * ARGC. Following that in the stack is a null-terminated sequence
332 * of pointers to argument strings. Then comes a null-terminated
333 * sequence of pointers to environment strings. Finally, there is a
334 * sequence of "auxiliary vector" entries.
335 *
336 * The second argument points to a place to store the dynamic linker's
337 * exit procedure pointer and the third to a place to store the main
338 * program's object.
339 *
340 * The return value is the main program's entry point.
341 */
342func_ptr_type
343_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
344{
345 Elf_Auxinfo *aux_info[AT_COUNT];
346 int i;
347 int argc;
348 char **argv;
349 char **env;
350 Elf_Auxinfo *aux;
351 Elf_Auxinfo *auxp;
352 const char *argv0;
55b88cae 353 Objlist_Entry *entry;
984263bc 354 Obj_Entry *obj;
984263bc 355
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356 /* marino: DO NOT MOVE THESE VARIABLES TO _rtld
357 Obj_Entry **preload_tail;
358 Objlist initlist;
35b2b265 359 from global to here. It will break the DWARF2 unwind scheme.
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360 The system compilers were unaffected, but not gcc 4.6
361 */
362
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363 /*
364 * On entry, the dynamic linker itself has not been relocated yet.
365 * Be very careful not to reference any global data until after
366 * init_rtld has returned. It is OK to reference file-scope statics
367 * and string constants, and to call static and global functions.
368 */
369
370 /* Find the auxiliary vector on the stack. */
371 argc = *sp++;
372 argv = (char **) sp;
373 sp += argc + 1; /* Skip over arguments and NULL terminator */
374 env = (char **) sp;
984263bc 375
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376 /*
377 * If we aren't already resident we have to dig out some more info.
378 * Note that auxinfo does not exist when we are resident.
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379 *
380 * I'm not sure about the ld_resident check. It seems to read zero
381 * prior to relocation, which is what we want. When running from a
382 * resident copy everything will be relocated so we are definitely
383 * good there.
33a8b578 384 */
5347affc 385 if (ld_resident == 0) {
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386 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
387 ;
388 aux = (Elf_Auxinfo *) sp;
389
390 /* Digest the auxiliary vector. */
391 for (i = 0; i < AT_COUNT; i++)
392 aux_info[i] = NULL;
393 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
394 if (auxp->a_type < AT_COUNT)
395 aux_info[auxp->a_type] = auxp;
396 }
397
398 /* Initialize and relocate ourselves. */
399 assert(aux_info[AT_BASE] != NULL);
b566341b 400 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
33a8b578 401 }
984263bc 402
5347affc 403 ld_index = 0; /* don't use old env cache in case we are resident */
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404 __progname = obj_rtld.path;
405 argv0 = argv[0] != NULL ? argv[0] : "(null)";
406 environ = env;
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407 glac = argc;
408 glav = argv;
984263bc 409
fcf53d9b 410 trust = !issetugid();
984263bc 411
8ca15ec8 412 ld_bind_now = _getenv_ld("LD_BIND_NOW");
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413 /*
414 * If the process is tainted, then we un-set the dangerous environment
415 * variables. The process will be marked as tainted until setuid(2)
416 * is called. If any child process calls setuid(2) we do not want any
417 * future processes to honor the potentially un-safe variables.
418 */
419 if (!trust) {
420 if ( unsetenv("LD_DEBUG")
421 || unsetenv("LD_PRELOAD")
422 || unsetenv("LD_LIBRARY_PATH")
423 || unsetenv("LD_ELF_HINTS_PATH")
424 || unsetenv("LD_LIBMAP")
425 || unsetenv("LD_LIBMAP_DISABLE")
35b2b265 426 || unsetenv("LD_LOADFLTR")
fcf53d9b
JM
427 ) {
428 _rtld_error("environment corrupt; aborting");
429 die();
430 }
984263bc 431 }
fcf53d9b 432 ld_debug = _getenv_ld("LD_DEBUG");
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433 libmap_disable = _getenv_ld("LD_LIBMAP_DISABLE") != NULL;
434 libmap_override = (char *)_getenv_ld("LD_LIBMAP");
fcf53d9b
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435 ld_library_path = _getenv_ld("LD_LIBRARY_PATH");
436 ld_preload = (char *)_getenv_ld("LD_PRELOAD");
437 ld_elf_hints_path = _getenv_ld("LD_ELF_HINTS_PATH");
35b2b265 438 ld_loadfltr = _getenv_ld("LD_LOADFLTR") != NULL;
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439 dangerous_ld_env = (ld_library_path != NULL)
440 || (ld_preload != NULL)
441 || (ld_elf_hints_path != NULL)
35b2b265 442 || ld_loadfltr
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443 || (libmap_override != NULL)
444 || libmap_disable
445 ;
8ca15ec8 446 ld_tracing = _getenv_ld("LD_TRACE_LOADED_OBJECTS");
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447 ld_utrace = _getenv_ld("LD_UTRACE");
448
449 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
450 ld_elf_hints_path = _PATH_ELF_HINTS;
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451
452 if (ld_debug != NULL && *ld_debug != '\0')
453 debug = 1;
454 dbg("%s is initialized, base address = %p", __progname,
455 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
456 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
457 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
458
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459 dbg("initializing thread locks");
460 lockdflt_init();
461
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462 /*
463 * If we are resident we can skip work that we have already done.
464 * Note that the stack is reset and there is no Elf_Auxinfo
465 * when running from a resident image, and the static globals setup
466 * between here and resident_skip will have already been setup.
467 */
8ca15ec8 468 if (ld_resident)
33a8b578 469 goto resident_skip1;
33a8b578 470
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471 /*
472 * Load the main program, or process its program header if it is
473 * already loaded.
474 */
475 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
476 int fd = aux_info[AT_EXECFD]->a_un.a_val;
477 dbg("loading main program");
478 obj_main = map_object(fd, argv0, NULL);
479 close(fd);
480 if (obj_main == NULL)
481 die();
e9de6dcc 482 max_stack_flags = obj->stack_flags;
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483 } else { /* Main program already loaded. */
484 const Elf_Phdr *phdr;
485 int phnum;
486 caddr_t entry;
487
488 dbg("processing main program's program header");
489 assert(aux_info[AT_PHDR] != NULL);
490 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
491 assert(aux_info[AT_PHNUM] != NULL);
492 phnum = aux_info[AT_PHNUM]->a_un.a_val;
493 assert(aux_info[AT_PHENT] != NULL);
494 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
495 assert(aux_info[AT_ENTRY] != NULL);
496 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
497 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
498 die();
499 }
500
fcf53d9b 501 char buf[MAXPATHLEN];
678e8cc6 502 if (aux_info[AT_EXECPATH] != NULL) {
fcf53d9b
JM
503 char *kexecpath;
504
505 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
506 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
507 if (kexecpath[0] == '/')
508 obj_main->path = kexecpath;
509 else if (getcwd(buf, sizeof(buf)) == NULL ||
510 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
511 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
512 obj_main->path = xstrdup(argv0);
513 else
514 obj_main->path = xstrdup(buf);
515 } else {
516 char resolved[MAXPATHLEN];
517 dbg("No AT_EXECPATH");
518 if (argv0[0] == '/') {
519 if (realpath(argv0, resolved) != NULL)
520 obj_main->path = xstrdup(resolved);
521 else
522 obj_main->path = xstrdup(argv0);
523 } else {
524 if (getcwd(buf, sizeof(buf)) != NULL
525 && strlcat(buf, "/", sizeof(buf)) < sizeof(buf)
526 && strlcat(buf, argv0, sizeof (buf)) < sizeof(buf)
527 && access(buf, R_OK) == 0
528 && realpath(buf, resolved) != NULL)
529 obj_main->path = xstrdup(resolved);
530 else
531 obj_main->path = xstrdup(argv0);
532 }
533 }
534 dbg("obj_main path %s", obj_main->path);
984263bc
MD
535 obj_main->mainprog = true;
536
e9de6dcc
JM
537 if (aux_info[AT_STACKPROT] != NULL &&
538 aux_info[AT_STACKPROT]->a_un.a_val != 0)
539 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val;
540
984263bc
MD
541 /*
542 * Get the actual dynamic linker pathname from the executable if
543 * possible. (It should always be possible.) That ensures that
544 * gdb will find the right dynamic linker even if a non-standard
545 * one is being used.
546 */
547 if (obj_main->interp != NULL &&
548 strcmp(obj_main->interp, obj_rtld.path) != 0) {
549 free(obj_rtld.path);
550 obj_rtld.path = xstrdup(obj_main->interp);
b7b05c9f 551 __progname = obj_rtld.path;
984263bc
MD
552 }
553
c3098c28 554 digest_dynamic(obj_main, 0);
984263bc
MD
555
556 linkmap_add(obj_main);
557 linkmap_add(&obj_rtld);
558
559 /* Link the main program into the list of objects. */
560 *obj_tail = obj_main;
561 obj_tail = &obj_main->next;
562 obj_count++;
fcf53d9b 563 obj_loads++;
984263bc 564 /* Make sure we don't call the main program's init and fini functions. */
fcf53d9b 565 obj_main->init = obj_main->fini = (Elf_Addr)NULL;
b28bf640 566 obj_main->init_array = obj_main->fini_array = (Elf_Addr)NULL;
984263bc
MD
567
568 /* Initialize a fake symbol for resolving undefined weak references. */
569 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
fcf53d9b
JM
570 sym_zero.st_shndx = SHN_UNDEF;
571 sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
572
573 if (!libmap_disable)
574 libmap_disable = (bool)lm_init(libmap_override);
984263bc
MD
575
576 dbg("loading LD_PRELOAD libraries");
577 if (load_preload_objects() == -1)
578 die();
579 preload_tail = obj_tail;
580
581 dbg("loading needed objects");
fcf53d9b 582 if (load_needed_objects(obj_main, 0) == -1)
984263bc
MD
583 die();
584
585 /* Make a list of all objects loaded at startup. */
fcf53d9b 586 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc 587 objlist_push_tail(&list_main, obj);
fcf53d9b
JM
588 obj->refcount++;
589 }
590
591 dbg("checking for required versions");
592 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
593 die();
984263bc 594
33a8b578
MD
595resident_skip1:
596
984263bc
MD
597 if (ld_tracing) { /* We're done */
598 trace_loaded_objects(obj_main);
599 exit(0);
600 }
601
33a8b578
MD
602 if (ld_resident) /* XXX clean this up! */
603 goto resident_skip2;
604
fcf53d9b 605 if (_getenv_ld("LD_DUMP_REL_PRE") != NULL) {
4a8d9350
JS
606 dump_relocations(obj_main);
607 exit (0);
608 }
609
55b88cae
DX
610 /* setup TLS for main thread */
611 dbg("initializing initial thread local storage");
612 STAILQ_FOREACH(entry, &list_main, link) {
613 /*
614 * Allocate all the initial objects out of the static TLS
615 * block even if they didn't ask for it.
616 */
617 allocate_tls_offset(entry->obj);
618 }
a1eee96a
MD
619
620 tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA;
621
622 /*
623 * Do not try to allocate the TLS here, let libc do it itself.
624 * (crt1 for the program will call _init_tls())
625 */
55b88cae 626
6192271e 627 if (relocate_objects(obj_main,
35b2b265 628 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, NULL) == -1)
6192271e 629 die();
984263bc 630
6192271e
MD
631 dbg("doing copy relocations");
632 if (do_copy_relocations(obj_main) == -1)
633 die();
1c76efe5 634
33a8b578
MD
635resident_skip2:
636
8ca15ec8 637 if (_getenv_ld("LD_RESIDENT_UNREGISTER_NOW")) {
33a8b578
MD
638 if (exec_sys_unregister(-1) < 0) {
639 dbg("exec_sys_unregister failed %d\n", errno);
640 exit(errno);
641 }
642 dbg("exec_sys_unregister success\n");
643 exit(0);
644 }
984263bc 645
fcf53d9b 646 if (_getenv_ld("LD_DUMP_REL_POST") != NULL) {
4a8d9350
JS
647 dump_relocations(obj_main);
648 exit (0);
649 }
650
984263bc
MD
651 dbg("initializing key program variables");
652 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
653 set_program_var("environ", env);
b566341b 654 set_program_var("__elf_aux_vector", aux);
984263bc 655
8ca15ec8
MD
656 if (_getenv_ld("LD_RESIDENT_REGISTER_NOW")) {
657 extern void resident_start(void);
658 ld_resident = 1;
659 if (exec_sys_register(resident_start) < 0) {
660 dbg("exec_sys_register failed %d\n", errno);
661 exit(errno);
662 }
663 dbg("exec_sys_register success\n");
664 exit(0);
665 }
666
984263bc
MD
667 /* Make a list of init functions to call. */
668 objlist_init(&initlist);
669 initlist_add_objects(obj_list, preload_tail, &initlist);
670
671 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
672
e9de6dcc
JM
673 map_stacks_exec(NULL);
674
0e63a289
JM
675 dbg("resolving ifuncs");
676 if (resolve_objects_ifunc(obj_main,
677 ld_bind_now != NULL && *ld_bind_now != '\0', NULL) == -1)
678 die();
679
a1eee96a
MD
680 /*
681 * Do NOT call the initlist here, give libc a chance to set up
682 * the initial TLS segment. crt1 will then call _rtld_call_init().
683 */
8ca15ec8 684
984263bc
MD
685 dbg("transferring control to program entry point = %p", obj_main->entry);
686
687 /* Return the exit procedure and the program entry point. */
688 *exit_proc = rtld_exit;
689 *objp = obj_main;
690 return (func_ptr_type) obj_main->entry;
691}
692
a1eee96a
MD
693/*
694 * Call the initialization list for dynamically loaded libraries.
695 * (called from crt1.c).
696 */
697void
698_rtld_call_init(void)
699{
fcf53d9b 700 RtldLockState lockstate;
35b2b265 701 Obj_Entry *obj;
fcf53d9b 702
b28bf640 703 preinitialize_main_object();
fcf53d9b
JM
704 wlock_acquire(rtld_bind_lock, &lockstate);
705 objlist_call_init(&initlist, &lockstate);
a1eee96a 706 objlist_clear(&initlist);
35b2b265
JM
707 dbg("loading filtees");
708 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
709 if (ld_loadfltr || obj->z_loadfltr)
710 load_filtees(obj, 0, &lockstate);
711 }
fcf53d9b 712 lock_release(rtld_bind_lock, &lockstate);
a1eee96a
MD
713}
714
0e63a289
JM
715void *
716rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def)
717{
718 void *ptr;
719 Elf_Addr target;
720
721 ptr = (void *)make_function_pointer(def, obj);
722 target = ((Elf_Addr (*)(void))ptr)();
723 return ((void *)target);
724}
725
984263bc 726Elf_Addr
4648abf3 727_rtld_bind(Obj_Entry *obj, Elf_Size reloff, void *stack)
984263bc
MD
728{
729 const Elf_Rel *rel;
730 const Elf_Sym *def;
731 const Obj_Entry *defobj;
732 Elf_Addr *where;
733 Elf_Addr target;
fcf53d9b 734 RtldLockState lockstate;
984263bc 735
fcf53d9b
JM
736 rlock_acquire(rtld_bind_lock, &lockstate);
737 if (sigsetjmp(lockstate.env, 0) != 0)
738 lock_upgrade(rtld_bind_lock, &lockstate);
984263bc
MD
739 if (obj->pltrel)
740 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
741 else
742 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
743
744 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
35b2b265
JM
745 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL,
746 &lockstate);
984263bc
MD
747 if (def == NULL)
748 die();
0e63a289
JM
749 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
750 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
751 else
752 target = (Elf_Addr)(defobj->relocbase + def->st_value);
984263bc
MD
753
754 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
755 defobj->strtab + def->st_name, basename(obj->path),
756 (void *)target, basename(defobj->path));
38e4b3b6
SS
757
758 /*
759 * If we have a function call tracing hook, and the
760 * hook would like to keep tracing this one function,
761 * prevent the relocation so we will wind up here
762 * the next time again.
763 *
764 * We don't want to functrace calls from the functracer
765 * to avoid recursive loops.
766 */
767 if (rtld_functrace != NULL && obj != rtld_functrace_obj) {
768 if (rtld_functrace(obj->path,
769 defobj->path,
770 defobj->strtab + def->st_name,
771 stack))
35b2b265
JM
772 lock_release(rtld_bind_lock, &lockstate);
773 return target;
38e4b3b6
SS
774 }
775
35b2b265
JM
776 /*
777 * Write the new contents for the jmpslot. Note that depending on
778 * architecture, the value which we need to return back to the
779 * lazy binding trampoline may or may not be the target
780 * address. The value returned from reloc_jmpslot() is the value
781 * that the trampoline needs.
782 */
783 target = reloc_jmpslot(where, target, defobj, obj, rel);
fcf53d9b 784 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
785 return target;
786}
787
788/*
789 * Error reporting function. Use it like printf. If formats the message
790 * into a buffer, and sets things up so that the next call to dlerror()
791 * will return the message.
792 */
793void
794_rtld_error(const char *fmt, ...)
795{
796 static char buf[512];
797 va_list ap;
798
799 va_start(ap, fmt);
abfcd5b1 800 rtld_vsnprintf(buf, sizeof buf, fmt, ap);
984263bc
MD
801 error_message = buf;
802 va_end(ap);
803}
804
805/*
806 * Return a dynamically-allocated copy of the current error message, if any.
807 */
808static char *
809errmsg_save(void)
810{
811 return error_message == NULL ? NULL : xstrdup(error_message);
812}
813
814/*
815 * Restore the current error message from a copy which was previously saved
816 * by errmsg_save(). The copy is freed.
817 */
818static void
819errmsg_restore(char *saved_msg)
820{
821 if (saved_msg == NULL)
822 error_message = NULL;
823 else {
824 _rtld_error("%s", saved_msg);
825 free(saved_msg);
826 }
827}
828
1c76efe5 829const char *
984263bc
MD
830basename(const char *name)
831{
832 const char *p = strrchr(name, '/');
833 return p != NULL ? p + 1 : name;
834}
835
fcf53d9b
JM
836static struct utsname uts;
837
838static int
839origin_subst_one(char **res, const char *real, const char *kw, const char *subst,
840 char *may_free)
841{
842 const char *p, *p1;
843 char *res1;
844 int subst_len;
845 int kw_len;
846
847 res1 = *res = NULL;
848 p = real;
849 subst_len = kw_len = 0;
850 for (;;) {
851 p1 = strstr(p, kw);
852 if (p1 != NULL) {
853 if (subst_len == 0) {
854 subst_len = strlen(subst);
855 kw_len = strlen(kw);
856 }
857 if (*res == NULL) {
858 *res = xmalloc(PATH_MAX);
859 res1 = *res;
860 }
861 if ((res1 - *res) + subst_len + (p1 - p) >= PATH_MAX) {
862 _rtld_error("Substitution of %s in %s cannot be performed",
863 kw, real);
864 if (may_free != NULL)
865 free(may_free);
866 free(res);
867 return (false);
868 }
869 memcpy(res1, p, p1 - p);
870 res1 += p1 - p;
871 memcpy(res1, subst, subst_len);
872 res1 += subst_len;
873 p = p1 + kw_len;
874 } else {
875 if (*res == NULL) {
876 if (may_free != NULL)
877 *res = may_free;
878 else
879 *res = xstrdup(real);
880 return (true);
881 }
882 *res1 = '\0';
883 if (may_free != NULL)
884 free(may_free);
885 if (strlcat(res1, p, PATH_MAX - (res1 - *res)) >= PATH_MAX) {
886 free(res);
887 return (false);
888 }
889 return (true);
890 }
891 }
892}
893
894static char *
895origin_subst(const char *real, const char *origin_path)
896{
897 char *res1, *res2, *res3, *res4;
898
899 if (uts.sysname[0] == '\0') {
900 if (uname(&uts) != 0) {
901 _rtld_error("utsname failed: %d", errno);
902 return (NULL);
903 }
904 }
905 if (!origin_subst_one(&res1, real, "$ORIGIN", origin_path, NULL) ||
906 !origin_subst_one(&res2, res1, "$OSNAME", uts.sysname, res1) ||
907 !origin_subst_one(&res3, res2, "$OSREL", uts.release, res2) ||
908 !origin_subst_one(&res4, res3, "$PLATFORM", uts.machine, res3))
909 return (NULL);
910 return (res4);
911}
912
984263bc
MD
913static void
914die(void)
915{
916 const char *msg = dlerror();
917
918 if (msg == NULL)
919 msg = "Fatal error";
abfcd5b1 920 rtld_fdputstr(STDERR_FILENO, msg);
d8eb4093 921 rtld_fdputchar(STDERR_FILENO, '\n');
abfcd5b1 922 _exit(1);
984263bc
MD
923}
924
925/*
926 * Process a shared object's DYNAMIC section, and save the important
927 * information in its Obj_Entry structure.
928 */
929static void
b566341b
JM
930digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
931 const Elf_Dyn **dyn_soname)
984263bc
MD
932{
933 const Elf_Dyn *dynp;
934 Needed_Entry **needed_tail = &obj->needed;
35b2b265
JM
935 Needed_Entry **needed_filtees_tail = &obj->needed_filtees;
936 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees;
984263bc
MD
937 int plttype = DT_REL;
938
b566341b
JM
939 *dyn_rpath = NULL;
940 *dyn_soname = NULL;
941
fcf53d9b 942 obj->bind_now = false;
984263bc
MD
943 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
944 switch (dynp->d_tag) {
945
946 case DT_REL:
947 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
948 break;
949
950 case DT_RELSZ:
951 obj->relsize = dynp->d_un.d_val;
952 break;
953
954 case DT_RELENT:
955 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
956 break;
957
958 case DT_JMPREL:
959 obj->pltrel = (const Elf_Rel *)
960 (obj->relocbase + dynp->d_un.d_ptr);
961 break;
962
963 case DT_PLTRELSZ:
964 obj->pltrelsize = dynp->d_un.d_val;
965 break;
966
967 case DT_RELA:
968 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
969 break;
970
971 case DT_RELASZ:
972 obj->relasize = dynp->d_un.d_val;
973 break;
974
975 case DT_RELAENT:
976 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
977 break;
978
979 case DT_PLTREL:
980 plttype = dynp->d_un.d_val;
981 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
982 break;
983
984 case DT_SYMTAB:
985 obj->symtab = (const Elf_Sym *)
986 (obj->relocbase + dynp->d_un.d_ptr);
987 break;
988
989 case DT_SYMENT:
990 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
991 break;
992
993 case DT_STRTAB:
994 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
995 break;
996
997 case DT_STRSZ:
998 obj->strsize = dynp->d_un.d_val;
999 break;
1000
fcf53d9b
JM
1001 case DT_VERNEED:
1002 obj->verneed = (const Elf_Verneed *) (obj->relocbase +
1003 dynp->d_un.d_val);
1004 break;
1005
1006 case DT_VERNEEDNUM:
1007 obj->verneednum = dynp->d_un.d_val;
1008 break;
1009
1010 case DT_VERDEF:
1011 obj->verdef = (const Elf_Verdef *) (obj->relocbase +
1012 dynp->d_un.d_val);
1013 break;
1014
1015 case DT_VERDEFNUM:
1016 obj->verdefnum = dynp->d_un.d_val;
1017 break;
1018
1019 case DT_VERSYM:
1020 obj->versyms = (const Elf_Versym *)(obj->relocbase +
1021 dynp->d_un.d_val);
1022 break;
1023
984263bc
MD
1024 case DT_HASH:
1025 {
d697cc44 1026 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
984263bc
MD
1027 (obj->relocbase + dynp->d_un.d_ptr);
1028 obj->nbuckets = hashtab[0];
1029 obj->nchains = hashtab[1];
1030 obj->buckets = hashtab + 2;
1031 obj->chains = obj->buckets + obj->nbuckets;
1032 }
1033 break;
1034
1035 case DT_NEEDED:
1036 if (!obj->rtld) {
1037 Needed_Entry *nep = NEW(Needed_Entry);
1038 nep->name = dynp->d_un.d_val;
1039 nep->obj = NULL;
1040 nep->next = NULL;
1041
1042 *needed_tail = nep;
1043 needed_tail = &nep->next;
1044 }
1045 break;
1046
35b2b265
JM
1047 case DT_FILTER:
1048 if (!obj->rtld) {
1049 Needed_Entry *nep = NEW(Needed_Entry);
1050 nep->name = dynp->d_un.d_val;
1051 nep->obj = NULL;
1052 nep->next = NULL;
1053
1054 *needed_filtees_tail = nep;
1055 needed_filtees_tail = &nep->next;
1056 }
1057 break;
1058
1059 case DT_AUXILIARY:
1060 if (!obj->rtld) {
1061 Needed_Entry *nep = NEW(Needed_Entry);
1062 nep->name = dynp->d_un.d_val;
1063 nep->obj = NULL;
1064 nep->next = NULL;
1065
1066 *needed_aux_filtees_tail = nep;
1067 needed_aux_filtees_tail = &nep->next;
1068 }
1069 break;
1070
984263bc
MD
1071 case DT_PLTGOT:
1072 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
1073 break;
1074
1075 case DT_TEXTREL:
1076 obj->textrel = true;
1077 break;
1078
1079 case DT_SYMBOLIC:
1080 obj->symbolic = true;
1081 break;
1082
1083 case DT_RPATH:
167f7029 1084 case DT_RUNPATH: /* XXX: process separately */
984263bc
MD
1085 /*
1086 * We have to wait until later to process this, because we
1087 * might not have gotten the address of the string table yet.
1088 */
b566341b 1089 *dyn_rpath = dynp;
984263bc
MD
1090 break;
1091
1092 case DT_SONAME:
b566341b 1093 *dyn_soname = dynp;
984263bc
MD
1094 break;
1095
1096 case DT_INIT:
fcf53d9b 1097 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
984263bc
MD
1098 break;
1099
1100 case DT_FINI:
fcf53d9b 1101 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
984263bc
MD
1102 break;
1103
b28bf640
JM
1104 case DT_PREINIT_ARRAY:
1105 obj->preinit_array = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1106 break;
1107
1108 case DT_INIT_ARRAY:
1109 obj->init_array = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1110 break;
1111
1112 case DT_FINI_ARRAY:
1113 obj->fini_array = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1114 break;
1115
1116 case DT_PREINIT_ARRAYSZ:
1117 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1118 break;
1119
1120 case DT_INIT_ARRAYSZ:
1121 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1122 break;
1123
1124 case DT_FINI_ARRAYSZ:
1125 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1126 break;
1127
984263bc
MD
1128 case DT_DEBUG:
1129 /* XXX - not implemented yet */
c3098c28
SS
1130 if (!early)
1131 dbg("Filling in DT_DEBUG entry");
984263bc
MD
1132 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
1133 break;
1134
167f7029 1135 case DT_FLAGS:
fcf53d9b
JM
1136 if ((dynp->d_un.d_val & DF_ORIGIN) && trust)
1137 obj->z_origin = true;
167f7029
JS
1138 if (dynp->d_un.d_val & DF_SYMBOLIC)
1139 obj->symbolic = true;
1140 if (dynp->d_un.d_val & DF_TEXTREL)
1141 obj->textrel = true;
1142 if (dynp->d_un.d_val & DF_BIND_NOW)
1143 obj->bind_now = true;
8301820e
JM
1144 /*if (dynp->d_un.d_val & DF_STATIC_TLS)
1145 ;*/
167f7029
JS
1146 break;
1147
fcf53d9b
JM
1148 case DT_FLAGS_1:
1149 if (dynp->d_un.d_val & DF_1_NOOPEN)
1150 obj->z_noopen = true;
1151 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
1152 obj->z_origin = true;
8301820e
JM
1153 /*if (dynp->d_un.d_val & DF_1_GLOBAL)
1154 XXX ;*/
fcf53d9b
JM
1155 if (dynp->d_un.d_val & DF_1_BIND_NOW)
1156 obj->bind_now = true;
1157 if (dynp->d_un.d_val & DF_1_NODELETE)
1158 obj->z_nodelete = true;
35b2b265
JM
1159 if (dynp->d_un.d_val & DF_1_LOADFLTR)
1160 obj->z_loadfltr = true;
fcf53d9b
JM
1161 break;
1162
984263bc 1163 default:
fcf53d9b
JM
1164 if (!early) {
1165 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
1166 (long)dynp->d_tag);
1167 }
984263bc
MD
1168 break;
1169 }
1170 }
1171
1172 obj->traced = false;
1173
1174 if (plttype == DT_RELA) {
1175 obj->pltrela = (const Elf_Rela *) obj->pltrel;
1176 obj->pltrel = NULL;
1177 obj->pltrelasize = obj->pltrelsize;
1178 obj->pltrelsize = 0;
1179 }
b566341b
JM
1180}
1181
1182static void
1183digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
1184 const Elf_Dyn *dyn_soname)
1185{
984263bc 1186
fcf53d9b
JM
1187 if (obj->z_origin && obj->origin_path == NULL) {
1188 obj->origin_path = xmalloc(PATH_MAX);
1189 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1)
1190 die();
1191 }
1192
1193 if (dyn_rpath != NULL) {
1194 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
1195 if (obj->z_origin)
1196 obj->rpath = origin_subst(obj->rpath, obj->origin_path);
1197 }
1198
1199 if (dyn_soname != NULL)
1200 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
984263bc
MD
1201}
1202
b566341b
JM
1203static void
1204digest_dynamic(Obj_Entry *obj, int early)
1205{
1206 const Elf_Dyn *dyn_rpath;
1207 const Elf_Dyn *dyn_soname;
1208
1209 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname);
1210 digest_dynamic2(obj, dyn_rpath, dyn_soname);
1211}
1212
984263bc
MD
1213/*
1214 * Process a shared object's program header. This is used only for the
1215 * main program, when the kernel has already loaded the main program
1216 * into memory before calling the dynamic linker. It creates and
1217 * returns an Obj_Entry structure.
1218 */
1219static Obj_Entry *
1220digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
1221{
1222 Obj_Entry *obj;
1223 const Elf_Phdr *phlimit = phdr + phnum;
1224 const Elf_Phdr *ph;
1225 int nsegs = 0;
1226
1227 obj = obj_new();
1228 for (ph = phdr; ph < phlimit; ph++) {
fcf53d9b
JM
1229 if (ph->p_type != PT_PHDR)
1230 continue;
984263bc 1231
fcf53d9b
JM
1232 obj->phdr = phdr;
1233 obj->phsize = ph->p_memsz;
1234 obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
1235 break;
1236 }
1237
e9de6dcc
JM
1238 obj->stack_flags = PF_X | PF_R | PF_W;
1239
fcf53d9b
JM
1240 for (ph = phdr; ph < phlimit; ph++) {
1241 switch (ph->p_type) {
984263bc
MD
1242
1243 case PT_INTERP:
fcf53d9b 1244 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
984263bc
MD
1245 break;
1246
1247 case PT_LOAD:
1248 if (nsegs == 0) { /* First load segment */
1249 obj->vaddrbase = trunc_page(ph->p_vaddr);
fcf53d9b 1250 obj->mapbase = obj->vaddrbase + obj->relocbase;
984263bc
MD
1251 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
1252 obj->vaddrbase;
1253 } else { /* Last load segment */
1254 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1255 obj->vaddrbase;
1256 }
1257 nsegs++;
1258 break;
1259
1260 case PT_DYNAMIC:
fcf53d9b 1261 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
984263bc 1262 break;
55b88cae
DX
1263
1264 case PT_TLS:
1265 obj->tlsindex = 1;
1266 obj->tlssize = ph->p_memsz;
1267 obj->tlsalign = ph->p_align;
1268 obj->tlsinitsize = ph->p_filesz;
fcf53d9b 1269 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
55b88cae 1270 break;
007f494e 1271
e9de6dcc
JM
1272 case PT_GNU_STACK:
1273 obj->stack_flags = ph->p_flags;
1274 break;
1275
007f494e
JM
1276 case PT_GNU_RELRO:
1277 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
1278 obj->relro_size = round_page(ph->p_memsz);
1279 break;
984263bc
MD
1280 }
1281 }
1282 if (nsegs < 1) {
1283 _rtld_error("%s: too few PT_LOAD segments", path);
1284 return NULL;
1285 }
1286
1287 obj->entry = entry;
1288 return obj;
1289}
1290
1291static Obj_Entry *
1292dlcheck(void *handle)
1293{
1294 Obj_Entry *obj;
1295
1296 for (obj = obj_list; obj != NULL; obj = obj->next)
1297 if (obj == (Obj_Entry *) handle)
1298 break;
1299
1300 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1301 _rtld_error("Invalid shared object handle %p", handle);
1302 return NULL;
1303 }
1304 return obj;
1305}
1306
1307/*
1308 * If the given object is already in the donelist, return true. Otherwise
1309 * add the object to the list and return false.
1310 */
1311static bool
1312donelist_check(DoneList *dlp, const Obj_Entry *obj)
1313{
1314 unsigned int i;
1315
1316 for (i = 0; i < dlp->num_used; i++)
1317 if (dlp->objs[i] == obj)
1318 return true;
1319 /*
1320 * Our donelist allocation should always be sufficient. But if
1321 * our threads locking isn't working properly, more shared objects
1322 * could have been loaded since we allocated the list. That should
1323 * never happen, but we'll handle it properly just in case it does.
1324 */
1325 if (dlp->num_used < dlp->num_alloc)
1326 dlp->objs[dlp->num_used++] = obj;
1327 return false;
1328}
1329
1330/*
1331 * Hash function for symbol table lookup. Don't even think about changing
1332 * this. It is specified by the System V ABI.
1333 */
1334unsigned long
1335elf_hash(const char *name)
1336{
1337 const unsigned char *p = (const unsigned char *) name;
1338 unsigned long h = 0;
1339 unsigned long g;
1340
1341 while (*p != '\0') {
1342 h = (h << 4) + *p++;
1343 if ((g = h & 0xf0000000) != 0)
1344 h ^= g >> 24;
1345 h &= ~g;
1346 }
1347 return h;
1348}
1349
1350/*
1351 * Find the library with the given name, and return its full pathname.
1352 * The returned string is dynamically allocated. Generates an error
1353 * message and returns NULL if the library cannot be found.
1354 *
1355 * If the second argument is non-NULL, then it refers to an already-
1356 * loaded shared object, whose library search path will be searched.
1357 *
1358 * The search order is:
984263bc 1359 * LD_LIBRARY_PATH
4e390e27 1360 * rpath in the referencing file
984263bc
MD
1361 * ldconfig hints
1362 * /usr/lib
1363 */
1364static char *
fcf53d9b 1365find_library(const char *xname, const Obj_Entry *refobj)
984263bc
MD
1366{
1367 char *pathname;
fcf53d9b 1368 char *name;
984263bc 1369
fcf53d9b
JM
1370 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */
1371 if (xname[0] != '/' && !trust) {
984263bc 1372 _rtld_error("Absolute pathname required for shared object \"%s\"",
fcf53d9b 1373 xname);
984263bc
MD
1374 return NULL;
1375 }
fcf53d9b
JM
1376 if (refobj != NULL && refobj->z_origin)
1377 return origin_subst(xname, refobj->origin_path);
1378 else
1379 return xstrdup(xname);
984263bc
MD
1380 }
1381
fcf53d9b
JM
1382 if (libmap_disable || (refobj == NULL) ||
1383 (name = lm_find(refobj->path, xname)) == NULL)
1384 name = (char *)xname;
1385
984263bc
MD
1386 dbg(" Searching for \"%s\"", name);
1387
1388 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
1389 (refobj != NULL &&
1390 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1391 (pathname = search_library_path(name, gethints())) != NULL ||
1392 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
1393 return pathname;
1394
446c0d3a
JS
1395 if(refobj != NULL && refobj->path != NULL) {
1396 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
1397 name, basename(refobj->path));
1398 } else {
1399 _rtld_error("Shared object \"%s\" not found", name);
1400 }
984263bc
MD
1401 return NULL;
1402}
1403
1404/*
1405 * Given a symbol number in a referencing object, find the corresponding
1406 * definition of the symbol. Returns a pointer to the symbol, or NULL if
1407 * no definition was found. Returns a pointer to the Obj_Entry of the
1408 * defining object via the reference parameter DEFOBJ_OUT.
1409 */
1410const Elf_Sym *
1411find_symdef(unsigned long symnum, const Obj_Entry *refobj,
35b2b265
JM
1412 const Obj_Entry **defobj_out, int flags, SymCache *cache,
1413 RtldLockState *lockstate)
984263bc
MD
1414{
1415 const Elf_Sym *ref;
1416 const Elf_Sym *def;
1417 const Obj_Entry *defobj;
35b2b265 1418 SymLook req;
984263bc 1419 const char *name;
35b2b265 1420 int res;
984263bc
MD
1421
1422 /*
1423 * If we have already found this symbol, get the information from
1424 * the cache.
1425 */
1426 if (symnum >= refobj->nchains)
1427 return NULL; /* Bad object */
1428 if (cache != NULL && cache[symnum].sym != NULL) {
1429 *defobj_out = cache[symnum].obj;
1430 return cache[symnum].sym;
1431 }
1432
1433 ref = refobj->symtab + symnum;
1434 name = refobj->strtab + ref->st_name;
35b2b265 1435 def = NULL;
984263bc
MD
1436 defobj = NULL;
1437
0e588128
SS
1438 /*
1439 * We don't have to do a full scale lookup if the symbol is local.
1440 * We know it will bind to the instance in this load module; to
1441 * which we already have a pointer (ie ref). By not doing a lookup,
1442 * we not only improve performance, but it also avoids unresolvable
1443 * symbols when local symbols are not in the hash table.
1444 *
1445 * This might occur for TLS module relocations, which simply use
1446 * symbol 0.
1447 */
1448 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1449 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
c3098c28
SS
1450 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1451 symnum);
1452 }
35b2b265
JM
1453 symlook_init(&req, name);
1454 req.flags = flags;
1455 req.ventry = fetch_ventry(refobj, symnum);
1456 req.lockstate = lockstate;
1457 res = symlook_default(&req, refobj);
1458 if (res == 0) {
1459 def = req.sym_out;
1460 defobj = req.defobj_out;
1461 }
0e588128 1462 } else {
c3098c28
SS
1463 def = ref;
1464 defobj = refobj;
0e588128 1465 }
984263bc
MD
1466
1467 /*
1468 * If we found no definition and the reference is weak, treat the
1469 * symbol as having the value zero.
1470 */
1471 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1472 def = &sym_zero;
1473 defobj = obj_main;
1474 }
1475
1476 if (def != NULL) {
1477 *defobj_out = defobj;
1478 /* Record the information in the cache to avoid subsequent lookups. */
1479 if (cache != NULL) {
1480 cache[symnum].sym = def;
1481 cache[symnum].obj = defobj;
1482 }
fcf53d9b
JM
1483 } else {
1484 if (refobj != &obj_rtld)
1485 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1486 }
984263bc
MD
1487 return def;
1488}
1489
1490/*
1491 * Return the search path from the ldconfig hints file, reading it if
1492 * necessary. Returns NULL if there are problems with the hints file,
1493 * or if the search path there is empty.
1494 */
1495static const char *
1496gethints(void)
1497{
1498 static char *hints;
1499
1500 if (hints == NULL) {
1501 int fd;
1502 struct elfhints_hdr hdr;
1503 char *p;
1504
1505 /* Keep from trying again in case the hints file is bad. */
1506 hints = "";
1507
fcf53d9b 1508 if ((fd = open(ld_elf_hints_path, O_RDONLY)) == -1)
984263bc
MD
1509 return NULL;
1510 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1511 hdr.magic != ELFHINTS_MAGIC ||
1512 hdr.version != 1) {
1513 close(fd);
1514 return NULL;
1515 }
1516 p = xmalloc(hdr.dirlistlen + 1);
1517 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
fcf53d9b 1518 read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) {
984263bc
MD
1519 free(p);
1520 close(fd);
1521 return NULL;
1522 }
1523 hints = p;
1524 close(fd);
1525 }
1526 return hints[0] != '\0' ? hints : NULL;
1527}
1528
1529static void
1530init_dag(Obj_Entry *root)
1531{
153ab392
JM
1532 const Needed_Entry *needed;
1533 const Objlist_Entry *elm;
984263bc
MD
1534 DoneList donelist;
1535
fcf53d9b
JM
1536 if (root->dag_inited)
1537 return;
984263bc 1538 donelist_init(&donelist);
984263bc 1539
153ab392
JM
1540 /* Root object belongs to own DAG. */
1541 objlist_push_tail(&root->dldags, root);
1542 objlist_push_tail(&root->dagmembers, root);
1543 donelist_check(&donelist, root);
fcf53d9b 1544
153ab392
JM
1545 /*
1546 * Add dependencies of root object to DAG in breadth order
1547 * by exploiting the fact that each new object get added
1548 * to the tail of the dagmembers list.
1549 */
1550 STAILQ_FOREACH(elm, &root->dagmembers, link) {
1551 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) {
1552 if (needed->obj == NULL || donelist_check(&donelist, needed->obj))
1553 continue;
1554 objlist_push_tail(&needed->obj->dldags, root);
1555 objlist_push_tail(&root->dagmembers, needed->obj);
1556 }
1557 }
1558 root->dag_inited = true;
984263bc
MD
1559}
1560
1561/*
1562 * Initialize the dynamic linker. The argument is the address at which
1563 * the dynamic linker has been mapped into memory. The primary task of
1564 * this function is to relocate the dynamic linker.
1565 */
1566static void
b566341b 1567init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
984263bc 1568{
c3098c28 1569 Obj_Entry objtmp; /* Temporary rtld object */
b566341b
JM
1570 const Elf_Dyn *dyn_rpath;
1571 const Elf_Dyn *dyn_soname;
c3098c28 1572
984263bc
MD
1573 /*
1574 * Conjure up an Obj_Entry structure for the dynamic linker.
1575 *
fcf53d9b
JM
1576 * The "path" member can't be initialized yet because string constants
1577 * cannot yet be accessed. Below we will set it correctly.
984263bc 1578 */
4648abf3 1579 memset(&objtmp, 0, sizeof(objtmp));
c3098c28
SS
1580 objtmp.path = NULL;
1581 objtmp.rtld = true;
1582 objtmp.mapbase = mapbase;
984263bc 1583#ifdef PIC
c3098c28 1584 objtmp.relocbase = mapbase;
984263bc 1585#endif
fcf53d9b 1586 if (RTLD_IS_DYNAMIC()) {
c3098c28 1587 objtmp.dynamic = rtld_dynamic(&objtmp);
b566341b 1588 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname);
c3098c28
SS
1589 assert(objtmp.needed == NULL);
1590 assert(!objtmp.textrel);
984263bc
MD
1591
1592 /*
1593 * Temporarily put the dynamic linker entry into the object list, so
1594 * that symbols can be found.
1595 */
984263bc 1596
35b2b265 1597 relocate_objects(&objtmp, true, &objtmp, NULL);
984263bc
MD
1598 }
1599
c3098c28 1600 /* Initialize the object list. */
984263bc 1601 obj_tail = &obj_list;
c3098c28
SS
1602
1603 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1604 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
984263bc 1605
b566341b
JM
1606#ifdef ENABLE_OSRELDATE
1607 if (aux_info[AT_OSRELDATE] != NULL)
1608 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
1609#endif
1610
1611 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname);
1612
984263bc 1613 /* Replace the path with a dynamically allocated copy. */
c3098c28 1614 obj_rtld.path = xstrdup(PATH_RTLD);
984263bc
MD
1615
1616 r_debug.r_brk = r_debug_state;
1617 r_debug.r_state = RT_CONSISTENT;
1618}
1619
1620/*
1621 * Add the init functions from a needed object list (and its recursive
1622 * needed objects) to "list". This is not used directly; it is a helper
1623 * function for initlist_add_objects(). The write lock must be held
1624 * when this function is called.
1625 */
1626static void
1627initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1628{
1629 /* Recursively process the successor needed objects. */
1630 if (needed->next != NULL)
1631 initlist_add_neededs(needed->next, list);
1632
1633 /* Process the current needed object. */
1634 if (needed->obj != NULL)
1635 initlist_add_objects(needed->obj, &needed->obj->next, list);
1636}
1637
1638/*
1639 * Scan all of the DAGs rooted in the range of objects from "obj" to
1640 * "tail" and add their init functions to "list". This recurses over
1641 * the DAGs and ensure the proper init ordering such that each object's
1642 * needed libraries are initialized before the object itself. At the
1643 * same time, this function adds the objects to the global finalization
1644 * list "list_fini" in the opposite order. The write lock must be
1645 * held when this function is called.
1646 */
1647static void
1648initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1649{
fcf53d9b 1650 if (obj->init_scanned || obj->init_done)
984263bc 1651 return;
fcf53d9b 1652 obj->init_scanned = true;
984263bc
MD
1653
1654 /* Recursively process the successor objects. */
1655 if (&obj->next != tail)
1656 initlist_add_objects(obj->next, tail, list);
1657
1658 /* Recursively process the needed objects. */
1659 if (obj->needed != NULL)
1660 initlist_add_neededs(obj->needed, list);
1661
1662 /* Add the object to the init list. */
b28bf640 1663 if (obj->init != (Elf_Addr)NULL || obj->init_array != (Elf_Addr)NULL)
984263bc
MD
1664 objlist_push_tail(list, obj);
1665
1666 /* Add the object to the global fini list in the reverse order. */
b28bf640
JM
1667 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL)
1668 && !obj->on_fini_list) {
984263bc 1669 objlist_push_head(&list_fini, obj);
fcf53d9b
JM
1670 obj->on_fini_list = true;
1671 }
984263bc
MD
1672}
1673
fcf53d9b
JM
1674#ifndef FPTR_TARGET
1675#define FPTR_TARGET(f) ((Elf_Addr) (f))
1676#endif
1677
984263bc
MD
1678static bool
1679is_exported(const Elf_Sym *def)
1680{
d697cc44 1681 Elf_Addr value;
984263bc
MD
1682 const func_ptr_type *p;
1683
d697cc44 1684 value = (Elf_Addr)(obj_rtld.relocbase + def->st_value);
fcf53d9b
JM
1685 for (p = exports; *p != NULL; p++)
1686 if (FPTR_TARGET(*p) == value)
984263bc
MD
1687 return true;
1688 return false;
1689}
1690
35b2b265
JM
1691static void
1692free_needed_filtees(Needed_Entry *n)
1693{
1694 Needed_Entry *needed, *needed1;
1695
1696 for (needed = n; needed != NULL; needed = needed->next) {
1697 if (needed->obj != NULL) {
1698 dlclose(needed->obj);
1699 needed->obj = NULL;
1700 }
1701 }
1702 for (needed = n; needed != NULL; needed = needed1) {
1703 needed1 = needed->next;
1704 free(needed);
1705 }
1706}
1707
1708static void
1709unload_filtees(Obj_Entry *obj)
1710{
1711
1712 free_needed_filtees(obj->needed_filtees);
1713 obj->needed_filtees = NULL;
1714 free_needed_filtees(obj->needed_aux_filtees);
1715 obj->needed_aux_filtees = NULL;
1716 obj->filtees_loaded = false;
1717}
1718
1719static void
1720load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags)
1721{
1722
1723 for (; needed != NULL; needed = needed->next) {
1724 needed->obj = dlopen_object(obj->strtab + needed->name, obj,
1725 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) |
1726 RTLD_LOCAL);
1727 }
1728}
1729
1730static void
1731load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate)
1732{
1733
1734 lock_restart_for_upgrade(lockstate);
1735 if (!obj->filtees_loaded) {
1736 load_filtee1(obj, obj->needed_filtees, flags);
1737 load_filtee1(obj, obj->needed_aux_filtees, flags);
1738 obj->filtees_loaded = true;
1739 }
1740}
1741
1742static int
1743process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags)
1744{
1745 Obj_Entry *obj1;
1746
1747 for (; needed != NULL; needed = needed->next) {
1748 obj1 = needed->obj = load_object(obj->strtab + needed->name, obj,
1749 flags & ~RTLD_LO_NOLOAD);
1750 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0)
1751 return (-1);
1752 if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) {
1753 dbg("obj %s nodelete", obj1->path);
1754 init_dag(obj1);
1755 ref_dag(obj1);
1756 obj1->ref_nodel = true;
1757 }
1758 }
1759 return (0);
1760}
1761
984263bc
MD
1762/*
1763 * Given a shared object, traverse its list of needed objects, and load
1764 * each of them. Returns 0 on success. Generates an error message and
1765 * returns -1 on failure.
1766 */
1767static int
fcf53d9b 1768load_needed_objects(Obj_Entry *first, int flags)
984263bc 1769{
35b2b265 1770 Obj_Entry *obj;
984263bc
MD
1771
1772 for (obj = first; obj != NULL; obj = obj->next) {
35b2b265
JM
1773 if (process_needed(obj, obj->needed, flags) == -1)
1774 return (-1);
984263bc 1775 }
fcf53d9b 1776 return (0);
984263bc
MD
1777}
1778
1779static int
1780load_preload_objects(void)
1781{
1782 char *p = ld_preload;
1783 static const char delim[] = " \t:;";
1784
1785 if (p == NULL)
eecd52b2 1786 return 0;
984263bc
MD
1787
1788 p += strspn(p, delim);
1789 while (*p != '\0') {
1790 size_t len = strcspn(p, delim);
984263bc 1791 char savech;
38e4b3b6 1792 Obj_Entry *obj;
35b2b265
JM
1793 SymLook req;
1794 int res;
984263bc
MD
1795
1796 savech = p[len];
1797 p[len] = '\0';
fcf53d9b 1798 obj = load_object(p, NULL, 0);
38e4b3b6 1799 if (obj == NULL)
984263bc
MD
1800 return -1; /* XXX - cleanup */
1801 p[len] = savech;
1802 p += len;
1803 p += strspn(p, delim);
38e4b3b6
SS
1804
1805 /* Check for the magic tracing function */
35b2b265
JM
1806 symlook_init(&req, RTLD_FUNCTRACE);
1807 res = symlook_obj(&req, obj);
1808 if (res == 0) {
1809 rtld_functrace = (void *)(req.defobj_out->relocbase +
1810 req.sym_out->st_value);
1811 rtld_functrace_obj = req.defobj_out;
38e4b3b6 1812 }
984263bc 1813 }
fcf53d9b 1814 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
984263bc
MD
1815 return 0;
1816}
1817
b6a22d96 1818/*
fcf53d9b
JM
1819 * Load a shared object into memory, if it is not already loaded.
1820 *
1821 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1822 * on failure.
b6a22d96
JS
1823 */
1824static Obj_Entry *
fcf53d9b 1825load_object(const char *name, const Obj_Entry *refobj, int flags)
b6a22d96
JS
1826{
1827 Obj_Entry *obj;
fcf53d9b
JM
1828 int fd = -1;
1829 struct stat sb;
1830 char *path;
b6a22d96 1831
fcf53d9b
JM
1832 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1833 if (object_match_name(obj, name))
1834 return obj;
b6a22d96 1835
fcf53d9b
JM
1836 path = find_library(name, refobj);
1837 if (path == NULL)
1838 return NULL;
2d6b58a8 1839
fcf53d9b
JM
1840 /*
1841 * If we didn't find a match by pathname, open the file and check
1842 * again by device and inode. This avoids false mismatches caused
1843 * by multiple links or ".." in pathnames.
1844 *
1845 * To avoid a race, we open the file and use fstat() rather than
1846 * using stat().
1847 */
1848 if ((fd = open(path, O_RDONLY)) == -1) {
2d6b58a8 1849 _rtld_error("Cannot open \"%s\"", path);
fcf53d9b
JM
1850 free(path);
1851 return NULL;
2d6b58a8 1852 }
fcf53d9b 1853 if (fstat(fd, &sb) == -1) {
2d6b58a8 1854 _rtld_error("Cannot fstat \"%s\"", path);
fcf53d9b
JM
1855 close(fd);
1856 free(path);
2d6b58a8
JS
1857 return NULL;
1858 }
fcf53d9b
JM
1859 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1860 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
2d6b58a8 1861 break;
fcf53d9b
JM
1862 if (obj != NULL) {
1863 object_add_name(obj, name);
1864 free(path);
1865 close(fd);
1866 return obj;
1867 }
1868 if (flags & RTLD_LO_NOLOAD) {
1869 free(path);
8bdeb8d3 1870 close(fd);
fcf53d9b 1871 return (NULL);
2d6b58a8
JS
1872 }
1873
fcf53d9b
JM
1874 /* First use of this object, so we must map it in */
1875 obj = do_load_object(fd, name, path, &sb, flags);
1876 if (obj == NULL)
1877 free(path);
1878 close(fd);
1879
1880 return obj;
2d6b58a8
JS
1881}
1882
984263bc 1883static Obj_Entry *
fcf53d9b
JM
1884do_load_object(int fd, const char *name, char *path, struct stat *sbp,
1885 int flags)
984263bc
MD
1886{
1887 Obj_Entry *obj;
fcf53d9b 1888 struct statfs fs;
984263bc 1889
fcf53d9b
JM
1890 /*
1891 * but first, make sure that environment variables haven't been
1892 * used to circumvent the noexec flag on a filesystem.
1893 */
1894 if (dangerous_ld_env) {
1895 if (fstatfs(fd, &fs) != 0) {
1896 _rtld_error("Cannot fstatfs \"%s\"", path);
1897 return NULL;
1898 }
1899 if (fs.f_flags & MNT_NOEXEC) {
1900 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
1901 return NULL;
1902 }
984263bc 1903 }
2d6b58a8 1904 dbg("loading \"%s\"", path);
fcf53d9b
JM
1905 obj = map_object(fd, path, sbp);
1906 if (obj == NULL)
2d6b58a8 1907 return NULL;
984263bc 1908
fcf53d9b 1909 object_add_name(obj, name);
2d6b58a8 1910 obj->path = path;
c3098c28 1911 digest_dynamic(obj, 0);
fcf53d9b
JM
1912 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
1913 RTLD_LO_DLOPEN) {
1914 dbg("refusing to load non-loadable \"%s\"", obj->path);
1915 _rtld_error("Cannot dlopen non-loadable %s", obj->path);
1916 munmap(obj->mapbase, obj->mapsize);
1917 obj_free(obj);
1918 return (NULL);
1919 }
984263bc 1920
2d6b58a8
JS
1921 *obj_tail = obj;
1922 obj_tail = &obj->next;
1923 obj_count++;
fcf53d9b 1924 obj_loads++;
2d6b58a8 1925 linkmap_add(obj); /* for GDB & dlinfo() */
e9de6dcc 1926 max_stack_flags |= obj->stack_flags;
984263bc 1927
139b8f34
SW
1928 dbg(" %p .. %p: %s", obj->mapbase,
1929 obj->mapbase + obj->mapsize - 1, obj->path);
2d6b58a8 1930 if (obj->textrel)
fcf53d9b
JM
1931 dbg(" WARNING: %s has impure text", obj->path);
1932 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
1933 obj->path);
984263bc 1934
984263bc
MD
1935 return obj;
1936}
1937
984263bc
MD
1938static Obj_Entry *
1939obj_from_addr(const void *addr)
1940{
984263bc
MD
1941 Obj_Entry *obj;
1942
984263bc 1943 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc
MD
1944 if (addr < (void *) obj->mapbase)
1945 continue;
c6873e56 1946 if (addr < (void *) (obj->mapbase + obj->mapsize))
984263bc
MD
1947 return obj;
1948 }
1949 return NULL;
1950}
1951
1952/*
1953 * Call the finalization functions for each of the objects in "list"
fcf53d9b
JM
1954 * belonging to the DAG of "root" and referenced once. If NULL "root"
1955 * is specified, every finalization function will be called regardless
1956 * of the reference count and the list elements won't be freed. All of
1957 * the objects are expected to have non-NULL fini functions.
984263bc
MD
1958 */
1959static void
fcf53d9b 1960objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
984263bc
MD
1961{
1962 Objlist_Entry *elm;
1963 char *saved_msg;
b28bf640
JM
1964 Elf_Addr *fini_addr;
1965 int index;
984263bc 1966
fcf53d9b
JM
1967 assert(root == NULL || root->refcount == 1);
1968
984263bc
MD
1969 /*
1970 * Preserve the current error message since a fini function might
1971 * call into the dynamic linker and overwrite it.
1972 */
1973 saved_msg = errmsg_save();
fcf53d9b
JM
1974 do {
1975 STAILQ_FOREACH(elm, list, link) {
1976 if (root != NULL && (elm->obj->refcount != 1 ||
1977 objlist_find(&root->dagmembers, elm->obj) == NULL))
1978 continue;
b28bf640 1979
fcf53d9b
JM
1980 /* Remove object from fini list to prevent recursive invocation. */
1981 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
1982 /*
1983 * XXX: If a dlopen() call references an object while the
1984 * fini function is in progress, we might end up trying to
1985 * unload the referenced object in dlclose() or the object
1986 * won't be unloaded although its fini function has been
1987 * called.
1988 */
1989 lock_release(rtld_bind_lock, lockstate);
b28bf640
JM
1990
1991 /*
1992 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. When this
1993 * happens, DT_FINI_ARRAY is processed first, and it is also processed
1994 * backwards. It is possible to encounter DT_FINI_ARRAY elements with
1995 * values of 0 or 1, but they need to be ignored.
1996 */
1997 fini_addr = (Elf_Addr *)elm->obj->fini_array;
1998 if (fini_addr != (Elf_Addr)NULL) {
1999 for (index = elm->obj->fini_array_num - 1; index >= 0; index--) {
2000 if (fini_addr[index] != 0 && fini_addr[index] != 1) {
2001 dbg("DSO Array: calling fini function for %s at %p",
2002 elm->obj->path, (void *)fini_addr[index]);
2003 LD_UTRACE(UTRACE_FINI_CALL, elm->obj,
2004 (void *)fini_addr[index], 0, 0, elm->obj->path);
2005 call_initfini_pointer(elm->obj, fini_addr[index]);
2006 }
2007 }
2008 }
2009 if (elm->obj->fini != (Elf_Addr)NULL) {
2010 dbg("DSO: calling fini function for %s at %p", elm->obj->path,
2011 (void *)elm->obj->fini);
2012 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini,
2013 0, 0, elm->obj->path);
2014 call_initfini_pointer(elm->obj, elm->obj->fini);
2015 }
fcf53d9b
JM
2016 wlock_acquire(rtld_bind_lock, lockstate);
2017 /* No need to free anything if process is going down. */
2018 if (root != NULL)
2019 free(elm);
2020 /*
2021 * We must restart the list traversal after every fini call
2022 * because a dlclose() call from the fini function or from
2023 * another thread might have modified the reference counts.
2024 */
2025 break;
984263bc 2026 }
fcf53d9b 2027 } while (elm != NULL);
984263bc
MD
2028 errmsg_restore(saved_msg);
2029}
2030
b28bf640
JM
2031/*
2032 * If the main program is defined with a .preinit_array section, call
2033 * each function in order. This must occur before the initialization
2034 * of any shared object or the main program.
2035 */
2036static void
2037preinitialize_main_object (void)
2038{
2039 Elf_Addr *init_addr;
2040 int index;
2041
2042 init_addr = (Elf_Addr *)obj_main->preinit_array;
2043 if (init_addr == (Elf_Addr)NULL)
2044 return;
2045
2046 for (index = 0; index < obj_main->preinit_array_num; index++)
2047 if (init_addr[index] != 0 && init_addr[index] != 1) {
2048 dbg("Calling preinit array function for %s at %p",
3673b089 2049 obj_main->path, (void *)init_addr[index]);
b28bf640
JM
2050 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)init_addr[index],
2051 0, 0, obj_main->path);
2052 call_array_pointer(init_addr[index], glac, glav, environ);
2053 }
2054}
2055
984263bc
MD
2056/*
2057 * Call the initialization functions for each of the objects in
2058 * "list". All of the objects are expected to have non-NULL init
2059 * functions.
2060 */
2061static void
fcf53d9b 2062objlist_call_init(Objlist *list, RtldLockState *lockstate)
984263bc
MD
2063{
2064 Objlist_Entry *elm;
fcf53d9b 2065 Obj_Entry *obj;
984263bc 2066 char *saved_msg;
b28bf640
JM
2067 Elf_Addr *init_addr;
2068 int index;
984263bc 2069
fcf53d9b
JM
2070 /*
2071 * Clean init_scanned flag so that objects can be rechecked and
2072 * possibly initialized earlier if any of vectors called below
2073 * cause the change by using dlopen.
2074 */
2075 for (obj = obj_list; obj != NULL; obj = obj->next)
2076 obj->init_scanned = false;
2077
984263bc
MD
2078 /*
2079 * Preserve the current error message since an init function might
2080 * call into the dynamic linker and overwrite it.
2081 */
2082 saved_msg = errmsg_save();
2083 STAILQ_FOREACH(elm, list, link) {
fcf53d9b
JM
2084 if (elm->obj->init_done) /* Initialized early. */
2085 continue;
b28bf640 2086
fcf53d9b
JM
2087 /*
2088 * Race: other thread might try to use this object before current
2089 * one completes the initilization. Not much can be done here
2090 * without better locking.
2091 */
2092 elm->obj->init_done = true;
2093 lock_release(rtld_bind_lock, lockstate);
b28bf640
JM
2094
2095 /*
2096 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. When
2097 * this happens, DT_INIT is processed first. It is possible to
2098 * encounter DT_INIT_ARRAY elements with values of 0 or 1, but they
2099 * need to be ignored.
2100 */
2101 if (elm->obj->init != (Elf_Addr)NULL) {
2102 dbg("DSO: calling init function for %s at %p", elm->obj->path,
2103 (void *)elm->obj->init);
2104 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init,
2105 0, 0, elm->obj->path);
2106 call_initfini_pointer(elm->obj, elm->obj->init);
2107 }
2108 init_addr = (Elf_Addr *)elm->obj->init_array;
2109 if (init_addr != (Elf_Addr)NULL) {
2110 for (index = 0; index < elm->obj->init_array_num; index++)
2111 if (init_addr[index] != 0 && init_addr[index] != 1) {
2112 dbg("DSO Array: calling init function for %s at %p",
2113 elm->obj->path, (void *)init_addr[index]);
2114 LD_UTRACE(UTRACE_INIT_CALL, elm->obj,
2115 (void *)init_addr[index], 0, 0, elm->obj->path);
2116 call_array_pointer(init_addr[index], glac, glav, environ);
2117 }
2118 }
fcf53d9b 2119 wlock_acquire(rtld_bind_lock, lockstate);
984263bc
MD
2120 }
2121 errmsg_restore(saved_msg);
2122}
2123
2124static void
2125objlist_clear(Objlist *list)
2126{
2127 Objlist_Entry *elm;
2128
2129 while (!STAILQ_EMPTY(list)) {
2130 elm = STAILQ_FIRST(list);
2131 STAILQ_REMOVE_HEAD(list, link);
2132 free(elm);
2133 }
2134}
2135
2136static Objlist_Entry *
2137objlist_find(Objlist *list, const Obj_Entry *obj)
2138{
2139 Objlist_Entry *elm;
2140
2141 STAILQ_FOREACH(elm, list, link)
2142 if (elm->obj == obj)
2143 return elm;
2144 return NULL;
2145}
2146
2147static void
2148objlist_init(Objlist *list)
2149{
2150 STAILQ_INIT(list);
2151}
2152
2153static void
2154objlist_push_head(Objlist *list, Obj_Entry *obj)
2155{
2156 Objlist_Entry *elm;
2157
2158 elm = NEW(Objlist_Entry);
2159 elm->obj = obj;
2160 STAILQ_INSERT_HEAD(list, elm, link);
2161}
2162
2163static void
2164objlist_push_tail(Objlist *list, Obj_Entry *obj)
2165{
2166 Objlist_Entry *elm;
2167
2168 elm = NEW(Objlist_Entry);
2169 elm->obj = obj;
2170 STAILQ_INSERT_TAIL(list, elm, link);
2171}
2172
2173static void
2174objlist_remove(Objlist *list, Obj_Entry *obj)
2175{
2176 Objlist_Entry *elm;
2177
2178 if ((elm = objlist_find(list, obj)) != NULL) {
2179 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2180 free(elm);
2181 }
2182}
2183
984263bc
MD
2184/*
2185 * Relocate newly-loaded shared objects. The argument is a pointer to
2186 * the Obj_Entry for the first such object. All objects from the first
2187 * to the end of the list of objects are relocated. Returns 0 on success,
2188 * or -1 on failure.
2189 */
2190static int
35b2b265
JM
2191relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
2192 RtldLockState *lockstate)
984263bc
MD
2193{
2194 Obj_Entry *obj;
2195
2196 for (obj = first; obj != NULL; obj = obj->next) {
c3098c28 2197 if (obj != rtldobj)
984263bc
MD
2198 dbg("relocating \"%s\"", obj->path);
2199 if (obj->nbuckets == 0 || obj->nchains == 0 || obj->buckets == NULL ||
2200 obj->symtab == NULL || obj->strtab == NULL) {
2201 _rtld_error("%s: Shared object has no run-time symbol table",
2202 obj->path);
2203 return -1;
2204 }
2205
2206 if (obj->textrel) {
2207 /* There are relocations to the write-protected text segment. */
2208 if (mprotect(obj->mapbase, obj->textsize,
2209 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
2210 _rtld_error("%s: Cannot write-enable text segment: %s",
2211 obj->path, strerror(errno));
2212 return -1;
2213 }
2214 }
2215
2216 /* Process the non-PLT relocations. */
35b2b265 2217 if (reloc_non_plt(obj, rtldobj, lockstate))
984263bc
MD
2218 return -1;
2219
4b89341e
MD
2220 /*
2221 * Reprotect the text segment. Make sure it is included in the
2222 * core dump since we modified it. This unfortunately causes the
2223 * entire text segment to core-out but we don't have much of a
2224 * choice. We could try to only reenable core dumps on pages
2225 * in which relocations occured but that is likely most of the text
2226 * pages anyway, and even that would not work because the rest of
2227 * the text pages would wind up as a read-only OBJT_DEFAULT object
2228 * (created due to our modifications) backed by the original OBJT_VNODE
2229 * object, and the ELF coredump code is currently only able to dump
2230 * vnode records for pure vnode-backed mappings, not vnode backings
2231 * to memory objects.
2232 */
2233 if (obj->textrel) {
2234 madvise(obj->mapbase, obj->textsize, MADV_CORE);
984263bc
MD
2235 if (mprotect(obj->mapbase, obj->textsize,
2236 PROT_READ|PROT_EXEC) == -1) {
2237 _rtld_error("%s: Cannot write-protect text segment: %s",
2238 obj->path, strerror(errno));
2239 return -1;
2240 }
2241 }
2242
0e63a289
JM
2243
2244 /* Set the special PLT or GOT entries. */
2245 init_pltgot(obj);
2246
984263bc
MD
2247 /* Process the PLT relocations. */
2248 if (reloc_plt(obj) == -1)
2249 return -1;
2250 /* Relocate the jump slots if we are doing immediate binding. */
167f7029 2251 if (obj->bind_now || bind_now)
35b2b265 2252 if (reloc_jmpslots(obj, lockstate) == -1)
984263bc
MD
2253 return -1;
2254
984263bc
MD
2255 /*
2256 * Set up the magic number and version in the Obj_Entry. These
2257 * were checked in the crt1.o from the original ElfKit, so we
2258 * set them for backward compatibility.
2259 */
2260 obj->magic = RTLD_MAGIC;
2261 obj->version = RTLD_VERSION;
2262
007f494e
JM
2263 /*
2264 * Set relocated data to read-only status if protection specified
2265 */
2266
2267 if (obj->relro_size) {
2268 if (mprotect(obj->relro_page, obj->relro_size, PROT_READ) == -1) {
2269 _rtld_error("%s: Cannot enforce relro relocation: %s",
2270 obj->path, strerror(errno));
2271 return -1;
2272 }
2273 }
984263bc
MD
2274 }
2275
0c151ba0 2276 return (0);
984263bc
MD
2277}
2278
0e63a289
JM
2279/*
2280 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots
2281 * referencing STT_GNU_IFUNC symbols is postponed till the other
2282 * relocations are done. The indirect functions specified as
2283 * ifunc are allowed to call other symbols, so we need to have
2284 * objects relocated before asking for resolution from indirects.
2285 *
2286 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion,
2287 * instead of the usual lazy handling of PLT slots. It is
2288 * consistent with how GNU does it.
2289 */
2290static int
2291resolve_object_ifunc(Obj_Entry *obj, bool bind_now, RtldLockState *lockstate)
2292{
2293 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1)
2294 return (-1);
2295 if ((obj->bind_now || bind_now) && obj->gnu_ifunc &&
2296 reloc_gnu_ifunc(obj, lockstate) == -1)
2297 return (-1);
2298 return (0);
2299}
2300
2301static int
2302resolve_objects_ifunc(Obj_Entry *first, bool bind_now, RtldLockState *lockstate)
2303{
2304 Obj_Entry *obj;
2305
2306 for (obj = first; obj != NULL; obj = obj->next) {
2307 if (resolve_object_ifunc(obj, bind_now, lockstate) == -1)
2308 return (-1);
2309 }
2310 return (0);
2311}
2312
2313static int
2314initlist_objects_ifunc(Objlist *list, bool bind_now, RtldLockState *lockstate)
2315{
2316 Objlist_Entry *elm;
2317
2318 STAILQ_FOREACH(elm, list, link) {
2319 if (resolve_object_ifunc(elm->obj, bind_now, lockstate) == -1)
2320 return (-1);
2321 }
2322 return (0);
2323}
2324
984263bc
MD
2325/*
2326 * Cleanup procedure. It will be called (by the atexit mechanism) just
2327 * before the process exits.
2328 */
2329static void
2330rtld_exit(void)
2331{
fcf53d9b 2332 RtldLockState lockstate;
984263bc 2333
fcf53d9b 2334 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc 2335 dbg("rtld_exit()");
fcf53d9b 2336 objlist_call_fini(&list_fini, NULL, &lockstate);
984263bc 2337 /* No need to remove the items from the list, since we are exiting. */
fcf53d9b
JM
2338 if (!libmap_disable)
2339 lm_fini();
2340 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2341}
2342
2343static void *
2344path_enumerate(const char *path, path_enum_proc callback, void *arg)
2345{
2346 if (path == NULL)
2347 return (NULL);
2348
2349 path += strspn(path, ":;");
2350 while (*path != '\0') {
2351 size_t len;
2352 char *res;
2353
2354 len = strcspn(path, ":;");
2355 res = callback(path, len, arg);
2356
2357 if (res != NULL)
2358 return (res);
2359
2360 path += len;
2361 path += strspn(path, ":;");
2362 }
2363
2364 return (NULL);
2365}
2366
2367struct try_library_args {
2368 const char *name;
2369 size_t namelen;
2370 char *buffer;
2371 size_t buflen;
2372};
2373
2374static void *
2375try_library_path(const char *dir, size_t dirlen, void *param)
2376{
2377 struct try_library_args *arg;
2378
2379 arg = param;
2380 if (*dir == '/' || trust) {
2381 char *pathname;
2382
2383 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
2384 return (NULL);
2385
2386 pathname = arg->buffer;
2387 strncpy(pathname, dir, dirlen);
2388 pathname[dirlen] = '/';
2389 strcpy(pathname + dirlen + 1, arg->name);
2390
2391 dbg(" Trying \"%s\"", pathname);
2392 if (access(pathname, F_OK) == 0) { /* We found it */
2393 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
2394 strcpy(pathname, arg->buffer);
2395 return (pathname);
2396 }
2397 }
2398 return (NULL);
2399}
2400
2401static char *
2402search_library_path(const char *name, const char *path)
2403{
2404 char *p;
2405 struct try_library_args arg;
2406
2407 if (path == NULL)
2408 return NULL;
2409
2410 arg.name = name;
2411 arg.namelen = strlen(name);
2412 arg.buffer = xmalloc(PATH_MAX);
2413 arg.buflen = PATH_MAX;
2414
2415 p = path_enumerate(path, try_library_path, &arg);
2416
2417 free(arg.buffer);
2418
2419 return (p);
2420}
2421
2422int
2423dlclose(void *handle)
2424{
2425 Obj_Entry *root;
fcf53d9b 2426 RtldLockState lockstate;
984263bc 2427
fcf53d9b 2428 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2429 root = dlcheck(handle);
2430 if (root == NULL) {
fcf53d9b 2431 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2432 return -1;
2433 }
fcf53d9b
JM
2434 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
2435 root->path);
984263bc
MD
2436
2437 /* Unreference the object and its dependencies. */
2438 root->dl_refcount--;
139b8f34 2439
fcf53d9b 2440 if (root->refcount == 1) {
984263bc 2441 /*
fcf53d9b
JM
2442 * The object will be no longer referenced, so we must unload it.
2443 * First, call the fini functions.
984263bc 2444 */
fcf53d9b
JM
2445 objlist_call_fini(&list_fini, root, &lockstate);
2446
2447 unref_dag(root);
984263bc
MD
2448
2449 /* Finish cleaning up the newly-unreferenced objects. */
2450 GDB_STATE(RT_DELETE,&root->linkmap);
2451 unload_object(root);
2452 GDB_STATE(RT_CONSISTENT,NULL);
fcf53d9b
JM
2453 } else
2454 unref_dag(root);
2455
2456 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
2457 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2458 return 0;
2459}
2460
fcf53d9b 2461char *
984263bc
MD
2462dlerror(void)
2463{
2464 char *msg = error_message;
2465 error_message = NULL;
2466 return msg;
2467}
2468
984263bc
MD
2469void *
2470dlopen(const char *name, int mode)
2471{
153ab392 2472 RtldLockState lockstate;
35b2b265 2473 int lo_flags;
984263bc 2474
fcf53d9b 2475 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
984263bc 2476 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
153ab392
JM
2477 if (ld_tracing != NULL) {
2478 rlock_acquire(rtld_bind_lock, &lockstate);
2479 if (sigsetjmp(lockstate.env, 0) != 0)
2480 lock_upgrade(rtld_bind_lock, &lockstate);
2481 environ = (char **)*get_program_var_addr("environ", &lockstate);
2482 lock_release(rtld_bind_lock, &lockstate);
2483 }
fcf53d9b
JM
2484 lo_flags = RTLD_LO_DLOPEN;
2485 if (mode & RTLD_NODELETE)
2486 lo_flags |= RTLD_LO_NODELETE;
2487 if (mode & RTLD_NOLOAD)
2488 lo_flags |= RTLD_LO_NOLOAD;
2489 if (ld_tracing != NULL)
2490 lo_flags |= RTLD_LO_TRACE;
984263bc 2491
35b2b265
JM
2492 return (dlopen_object(name, obj_main, lo_flags,
2493 mode & (RTLD_MODEMASK | RTLD_GLOBAL)));
2494}
2495
0e63a289
JM
2496static void
2497dlopen_cleanup(Obj_Entry *obj)
2498{
2499
2500 obj->dl_refcount--;
2501 unref_dag(obj);
2502 if (obj->refcount == 0)
2503 unload_object(obj);
2504}
2505
35b2b265
JM
2506static Obj_Entry *
2507dlopen_object(const char *name, Obj_Entry *refobj, int lo_flags, int mode)
2508{
2509 Obj_Entry **old_obj_tail;
2510 Obj_Entry *obj;
2511 Objlist initlist;
2512 RtldLockState lockstate;
2513 int result;
2514
984263bc
MD
2515 objlist_init(&initlist);
2516
fcf53d9b 2517 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2518 GDB_STATE(RT_ADD,NULL);
2519
2520 old_obj_tail = obj_tail;
2521 obj = NULL;
2522 if (name == NULL) {
2523 obj = obj_main;
2524 obj->refcount++;
2525 } else {
35b2b265 2526 obj = load_object(name, refobj, lo_flags);
984263bc
MD
2527 }
2528
2529 if (obj) {
2530 obj->dl_refcount++;
139b8f34 2531 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
984263bc 2532 objlist_push_tail(&list_global, obj);
984263bc
MD
2533 if (*old_obj_tail != NULL) { /* We loaded something new. */
2534 assert(*old_obj_tail == obj);
35b2b265 2535 result = load_needed_objects(obj, lo_flags & RTLD_LO_DLOPEN);
fcf53d9b
JM
2536 init_dag(obj);
2537 ref_dag(obj);
2538 if (result != -1)
2539 result = rtld_verify_versions(&obj->dagmembers);
984263bc
MD
2540 if (result != -1 && ld_tracing)
2541 goto trace;
35b2b265
JM
2542 if (result == -1 || (relocate_objects(obj, (mode & RTLD_MODEMASK)
2543 == RTLD_NOW, &obj_rtld, &lockstate)) == -1) {
0e63a289 2544 dlopen_cleanup(obj);
984263bc
MD
2545 obj = NULL;
2546 } else {
2547 /* Make list of init functions to call. */
2548 initlist_add_objects(obj, &obj->next, &initlist);
2549 }
fcf53d9b
JM
2550 } else {
2551
2552 /*
2553 * Bump the reference counts for objects on this DAG. If
2554 * this is the first dlopen() call for the object that was
2555 * already loaded as a dependency, initialize the dag
2556 * starting at it.
2557 */
2558 init_dag(obj);
2559 ref_dag(obj);
2560
2561 if ((lo_flags & RTLD_LO_TRACE) != 0)
2562 goto trace;
2563 }
2564 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
2565 obj->z_nodelete) && !obj->ref_nodel) {
2566 dbg("obj %s nodelete", obj->path);
2567 ref_dag(obj);
2568 obj->z_nodelete = obj->ref_nodel = true;
2569 }
984263bc
MD
2570 }
2571
fcf53d9b
JM
2572 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
2573 name);
984263bc
MD
2574 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
2575
e9de6dcc
JM
2576 map_stacks_exec(&lockstate);
2577
0e63a289
JM
2578 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW,
2579 &lockstate) == -1) {
2580 objlist_clear(&initlist);
2581 dlopen_cleanup(obj);
2582 lock_release(rtld_bind_lock, &lockstate);
2583 return (NULL);
2584 }
2585
fcf53d9b
JM
2586 /* Call the init functions. */
2587 objlist_call_init(&initlist, &lockstate);
984263bc 2588 objlist_clear(&initlist);
fcf53d9b 2589 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2590 return obj;
2591trace:
2592 trace_loaded_objects(obj);
fcf53d9b 2593 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2594 exit(0);
2595}
2596
fcf53d9b
JM
2597static void *
2598do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
2599 int flags)
984263bc 2600{
fcf53d9b
JM
2601 DoneList donelist;
2602 const Obj_Entry *obj, *defobj;
35b2b265
JM
2603 const Elf_Sym *def;
2604 SymLook req;
fcf53d9b 2605 RtldLockState lockstate;
35b2b265 2606 int res;
984263bc 2607
984263bc
MD
2608 def = NULL;
2609 defobj = NULL;
35b2b265
JM
2610 symlook_init(&req, name);
2611 req.ventry = ve;
2612 req.flags = flags | SYMLOOK_IN_PLT;
2613 req.lockstate = &lockstate;
984263bc 2614
fcf53d9b
JM
2615 rlock_acquire(rtld_bind_lock, &lockstate);
2616 if (sigsetjmp(lockstate.env, 0) != 0)
2617 lock_upgrade(rtld_bind_lock, &lockstate);
984263bc
MD
2618 if (handle == NULL || handle == RTLD_NEXT ||
2619 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
984263bc 2620
984263bc
MD
2621 if ((obj = obj_from_addr(retaddr)) == NULL) {
2622 _rtld_error("Cannot determine caller's shared object");
fcf53d9b 2623 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2624 return NULL;
2625 }
2626 if (handle == NULL) { /* Just the caller's shared object. */
35b2b265
JM
2627 res = symlook_obj(&req, obj);
2628 if (res == 0) {
2629 def = req.sym_out;
2630 defobj = req.defobj_out;
2631 }
984263bc
MD
2632 } else if (handle == RTLD_NEXT || /* Objects after caller's */
2633 handle == RTLD_SELF) { /* ... caller included */
2634 if (handle == RTLD_NEXT)
2635 obj = obj->next;
2636 for (; obj != NULL; obj = obj->next) {
35b2b265
JM
2637 res = symlook_obj(&req, obj);
2638 if (res == 0) {
2639 if (def == NULL ||
2640 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) {
2641 def = req.sym_out;
2642 defobj = req.defobj_out;
fcf53d9b
JM
2643 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2644 break;
2645 }
2646 }
2647 }
2648 /*
2649 * Search the dynamic linker itself, and possibly resolve the
2650 * symbol from there. This is how the application links to
2651 * dynamic linker services such as dlopen.
2652 */
2653 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
35b2b265
JM
2654 res = symlook_obj(&req, &obj_rtld);
2655 if (res == 0 && is_exported(req.sym_out)) {
2656 def = req.sym_out;
2657 defobj = req.defobj_out;
984263bc
MD
2658 }
2659 }
2660 } else {
2661 assert(handle == RTLD_DEFAULT);
35b2b265
JM
2662 res = symlook_default(&req, obj);
2663 if (res == 0) {
2664 defobj = req.defobj_out;
2665 def = req.sym_out;
2666 }
984263bc
MD
2667 }
2668 } else {
2669 if ((obj = dlcheck(handle)) == NULL) {
fcf53d9b 2670 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2671 return NULL;
2672 }
2673
fb0c631e 2674 donelist_init(&donelist);
984263bc 2675 if (obj->mainprog) {
153ab392
JM
2676 /* Handle obtained by dlopen(NULL, ...) implies global scope. */
2677 res = symlook_global(&req, &donelist);
35b2b265
JM
2678 if (res == 0) {
2679 def = req.sym_out;
2680 defobj = req.defobj_out;
153ab392 2681 }
fcf53d9b 2682 /*
153ab392
JM
2683 * Search the dynamic linker itself, and possibly resolve the
2684 * symbol from there. This is how the application links to
2685 * dynamic linker services such as dlopen.
fcf53d9b 2686 */
153ab392
JM
2687 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2688 res = symlook_obj(&req, &obj_rtld);
35b2b265
JM
2689 if (res == 0) {
2690 def = req.sym_out;
2691 defobj = req.defobj_out;
2692 }
2693 }
153ab392
JM
2694 }
2695 else {
fcf53d9b 2696 /* Search the whole DAG rooted at the given object. */
153ab392 2697 res = symlook_list(&req, &obj->dagmembers, &donelist);
35b2b265
JM
2698 if (res == 0) {
2699 def = req.sym_out;
2700 defobj = req.defobj_out;
2701 }
984263bc
MD
2702 }
2703 }
2704
2705 if (def != NULL) {
fcf53d9b
JM
2706 lock_release(rtld_bind_lock, &lockstate);
2707
2708 /*
2709 * The value required by the caller is derived from the value
2710 * of the symbol. For the ia64 architecture, we need to
2711 * construct a function descriptor which the caller can use to
2712 * call the function with the right 'gp' value. For other
2713 * architectures and for non-functions, the value is simply
2714 * the relocated value of the symbol.
2715 */
2716 if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
0c151ba0 2717 return (make_function_pointer(def, defobj));
0e63a289
JM
2718 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
2719 return (rtld_resolve_ifunc(defobj, def));
1388aaaf
SW
2720 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) {
2721 tls_index ti;
2722 ti.ti_module = defobj->tlsindex;
2723 ti.ti_offset = def->st_value;
2724 return (__tls_get_addr(&ti));
2725 } else
0c151ba0 2726 return (defobj->relocbase + def->st_value);
984263bc
MD
2727 }
2728
2729 _rtld_error("Undefined symbol \"%s\"", name);
fcf53d9b 2730 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2731 return NULL;
2732}
2733
fcf53d9b
JM
2734void *
2735dlsym(void *handle, const char *name)
2736{
2737 return do_dlsym(handle, name, __builtin_return_address(0), NULL,
2738 SYMLOOK_DLSYM);
2739}
2740
2741dlfunc_t
2742dlfunc(void *handle, const char *name)
2743{
2744 union {
2745 void *d;
2746 dlfunc_t f;
2747 } rv;
2748
2749 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
2750 SYMLOOK_DLSYM);
2751 return (rv.f);
2752}
2753
2754void *
2755dlvsym(void *handle, const char *name, const char *version)
2756{
2757 Ver_Entry ventry;
2758
2759 ventry.name = version;
2760 ventry.file = NULL;
2761 ventry.hash = elf_hash(version);
2762 ventry.flags= 0;
2763 return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
2764 SYMLOOK_DLSYM);
2765}
2766
2767int
2768_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
2769{
2770 const Obj_Entry *obj;
2771 RtldLockState lockstate;
2772
2773 rlock_acquire(rtld_bind_lock, &lockstate);
2774 obj = obj_from_addr(addr);
2775 if (obj == NULL) {
2776 _rtld_error("No shared object contains address");
2777 lock_release(rtld_bind_lock, &lockstate);
2778 return (0);
2779 }
2780 rtld_fill_dl_phdr_info(obj, phdr_info);
2781 lock_release(rtld_bind_lock, &lockstate);
2782 return (1);
2783}
2784
984263bc
MD
2785int
2786dladdr(const void *addr, Dl_info *info)
2787{
2788 const Obj_Entry *obj;
2789 const Elf_Sym *def;
2790 void *symbol_addr;
2791 unsigned long symoffset;
fcf53d9b
JM
2792 RtldLockState lockstate;
2793
2794 rlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2795 obj = obj_from_addr(addr);
2796 if (obj == NULL) {
2797 _rtld_error("No shared object contains address");
fcf53d9b 2798 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2799 return 0;
2800 }
2801 info->dli_fname = obj->path;
2802 info->dli_fbase = obj->mapbase;
60233e58 2803 info->dli_saddr = NULL;
984263bc
MD
2804 info->dli_sname = NULL;
2805
2806 /*
2807 * Walk the symbol list looking for the symbol whose address is
2808 * closest to the address sent in.
2809 */
2810 for (symoffset = 0; symoffset < obj->nchains; symoffset++) {
2811 def = obj->symtab + symoffset;
2812
2813 /*
2814 * For skip the symbol if st_shndx is either SHN_UNDEF or
2815 * SHN_COMMON.
2816 */
2817 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
2818 continue;
2819
2820 /*
2821 * If the symbol is greater than the specified address, or if it
2822 * is further away from addr than the current nearest symbol,
2823 * then reject it.
2824 */
2825 symbol_addr = obj->relocbase + def->st_value;
2826 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
2827 continue;
2828
2829 /* Update our idea of the nearest symbol. */
2830 info->dli_sname = obj->strtab + def->st_name;
2831 info->dli_saddr = symbol_addr;
2832
2833 /* Exact match? */
2834 if (info->dli_saddr == addr)
2835 break;
2836 }
fcf53d9b 2837 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2838 return 1;
2839}
2840
2841int
2842dlinfo(void *handle, int request, void *p)
2843{
2844 const Obj_Entry *obj;
fcf53d9b 2845 RtldLockState lockstate;
984263bc
MD
2846 int error;
2847
fcf53d9b 2848 rlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2849
2850 if (handle == NULL || handle == RTLD_SELF) {
2851 void *retaddr;
2852
2853 retaddr = __builtin_return_address(0); /* __GNUC__ only */
2854 if ((obj = obj_from_addr(retaddr)) == NULL)
2855 _rtld_error("Cannot determine caller's shared object");
2856 } else
2857 obj = dlcheck(handle);
2858
2859 if (obj == NULL) {
fcf53d9b 2860 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2861 return (-1);
2862 }
2863
2864 error = 0;
2865 switch (request) {
2866 case RTLD_DI_LINKMAP:
2867 *((struct link_map const **)p) = &obj->linkmap;
2868 break;
2869 case RTLD_DI_ORIGIN:
2870 error = rtld_dirname(obj->path, p);
2871 break;
2872
2873 case RTLD_DI_SERINFOSIZE:
2874 case RTLD_DI_SERINFO:
2875 error = do_search_info(obj, request, (struct dl_serinfo *)p);
2876 break;
2877
2878 default:
2879 _rtld_error("Invalid request %d passed to dlinfo()", request);
2880 error = -1;
2881 }
2882
fcf53d9b
JM
2883 lock_release(rtld_bind_lock, &lockstate);
2884
2885 return (error);
2886}
2887
2888static void
2889rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
2890{
2891
2892 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
2893 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ?
2894 STAILQ_FIRST(&obj->names)->name : obj->path;
2895 phdr_info->dlpi_phdr = obj->phdr;
2896 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
2897 phdr_info->dlpi_tls_modid = obj->tlsindex;
2898 phdr_info->dlpi_tls_data = obj->tlsinit;
2899 phdr_info->dlpi_adds = obj_loads;
2900 phdr_info->dlpi_subs = obj_loads - obj_count;
2901}
2902
2903int
2904dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
2905{
2906 struct dl_phdr_info phdr_info;
2907 const Obj_Entry *obj;
2908 RtldLockState bind_lockstate, phdr_lockstate;
2909 int error;
2910
2911 wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
2912 rlock_acquire(rtld_bind_lock, &bind_lockstate);
2913
2914 error = 0;
2915
2916 for (obj = obj_list; obj != NULL; obj = obj->next) {
2917 rtld_fill_dl_phdr_info(obj, &phdr_info);
2918 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0)
2919 break;
2920
2921 }
2922 lock_release(rtld_bind_lock, &bind_lockstate);
2923 lock_release(rtld_phdr_lock, &phdr_lockstate);
984263bc
MD
2924
2925 return (error);
2926}
2927
2928struct fill_search_info_args {
2929 int request;
2930 unsigned int flags;
2931 Dl_serinfo *serinfo;
2932 Dl_serpath *serpath;
2933 char *strspace;
2934};
2935
2936static void *
2937fill_search_info(const char *dir, size_t dirlen, void *param)
2938{
2939 struct fill_search_info_args *arg;
2940
2941 arg = param;
2942
2943 if (arg->request == RTLD_DI_SERINFOSIZE) {
2944 arg->serinfo->dls_cnt ++;
fcf53d9b 2945 arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1;
984263bc
MD
2946 } else {
2947 struct dl_serpath *s_entry;
2948
2949 s_entry = arg->serpath;
2950 s_entry->dls_name = arg->strspace;
2951 s_entry->dls_flags = arg->flags;
2952
2953 strncpy(arg->strspace, dir, dirlen);
2954 arg->strspace[dirlen] = '\0';
2955
2956 arg->strspace += dirlen + 1;
2957 arg->serpath++;
2958 }
2959
2960 return (NULL);
2961}
2962
2963static int
2964do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
2965{
2966 struct dl_serinfo _info;
2967 struct fill_search_info_args args;
2968
2969 args.request = RTLD_DI_SERINFOSIZE;
2970 args.serinfo = &_info;
2971
2972 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2973 _info.dls_cnt = 0;
2974
2975 path_enumerate(ld_library_path, fill_search_info, &args);
2976 path_enumerate(obj->rpath, fill_search_info, &args);
2977 path_enumerate(gethints(), fill_search_info, &args);
2978 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
2979
2980
2981 if (request == RTLD_DI_SERINFOSIZE) {
2982 info->dls_size = _info.dls_size;
2983 info->dls_cnt = _info.dls_cnt;
2984 return (0);
2985 }
2986
2987 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
2988 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
2989 return (-1);
2990 }
2991
2992 args.request = RTLD_DI_SERINFO;
2993 args.serinfo = info;
2994 args.serpath = &info->dls_serpath[0];
2995 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
2996
2997 args.flags = LA_SER_LIBPATH;
2998 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
2999 return (-1);
3000
3001 args.flags = LA_SER_RUNPATH;
3002 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
3003 return (-1);
3004
3005 args.flags = LA_SER_CONFIG;
3006 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
3007 return (-1);
3008
3009 args.flags = LA_SER_DEFAULT;
3010 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
3011 return (-1);
3012 return (0);
3013}
3014
3015static int
3016rtld_dirname(const char *path, char *bname)
3017{
3018 const char *endp;
3019
3020 /* Empty or NULL string gets treated as "." */
3021 if (path == NULL || *path == '\0') {
3022 bname[0] = '.';
3023 bname[1] = '\0';
3024 return (0);
3025 }
3026
3027 /* Strip trailing slashes */
3028 endp = path + strlen(path) - 1;
3029 while (endp > path && *endp == '/')
3030 endp--;
3031
3032 /* Find the start of the dir */
3033 while (endp > path && *endp != '/')
3034 endp--;
3035
3036 /* Either the dir is "/" or there are no slashes */
3037 if (endp == path) {
3038 bname[0] = *endp == '/' ? '/' : '.';
3039 bname[1] = '\0';
3040 return (0);
3041 } else {
3042 do {
3043 endp--;
3044 } while (endp > path && *endp == '/');
3045 }
3046
3047 if (endp - path + 2 > PATH_MAX)
3048 {
3049 _rtld_error("Filename is too long: %s", path);
3050 return(-1);
3051 }
3052
3053 strncpy(bname, path, endp - path + 1);
3054 bname[endp - path + 1] = '\0';
3055 return (0);
3056}
3057
fcf53d9b
JM
3058static int
3059rtld_dirname_abs(const char *path, char *base)
3060{
3061 char base_rel[PATH_MAX];
3062
3063 if (rtld_dirname(path, base) == -1)
3064 return (-1);
3065 if (base[0] == '/')
3066 return (0);
3067 if (getcwd(base_rel, sizeof(base_rel)) == NULL ||
3068 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) ||
3069 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel))
3070 return (-1);
3071 strcpy(base, base_rel);
3072 return (0);
3073}
3074
984263bc
MD
3075static void
3076linkmap_add(Obj_Entry *obj)
3077{
3078 struct link_map *l = &obj->linkmap;
3079 struct link_map *prev;
3080
3081 obj->linkmap.l_name = obj->path;
3082 obj->linkmap.l_addr = obj->mapbase;
3083 obj->linkmap.l_ld = obj->dynamic;
3084#ifdef __mips__
3085 /* GDB needs load offset on MIPS to use the symbols */
3086 obj->linkmap.l_offs = obj->relocbase;
3087#endif
3088
3089 if (r_debug.r_map == NULL) {
3090 r_debug.r_map = l;
3091 return;
3092 }
3093
3094 /*
3095 * Scan to the end of the list, but not past the entry for the
3096 * dynamic linker, which we want to keep at the very end.
3097 */
3098 for (prev = r_debug.r_map;
3099 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
3100 prev = prev->l_next)
3101 ;
3102
3103 /* Link in the new entry. */
3104 l->l_prev = prev;
3105 l->l_next = prev->l_next;
3106 if (l->l_next != NULL)
3107 l->l_next->l_prev = l;
3108 prev->l_next = l;
3109}
3110
3111static void
3112linkmap_delete(Obj_Entry *obj)
3113{
3114 struct link_map *l = &obj->linkmap;
3115
3116 if (l->l_prev == NULL) {
3117 if ((r_debug.r_map = l->l_next) != NULL)
3118 l->l_next->l_prev = NULL;
3119 return;
3120 }
3121
3122 if ((l->l_prev->l_next = l->l_next) != NULL)
3123 l->l_next->l_prev = l->l_prev;
3124}
3125
3126/*
3127 * Function for the debugger to set a breakpoint on to gain control.
3128 *
3129 * The two parameters allow the debugger to easily find and determine
3130 * what the runtime loader is doing and to whom it is doing it.
3131 *
3132 * When the loadhook trap is hit (r_debug_state, set at program
3133 * initialization), the arguments can be found on the stack:
3134 *
3135 * +8 struct link_map *m
3136 * +4 struct r_debug *rd
3137 * +0 RetAddr
3138 */
3139void
3140r_debug_state(struct r_debug* rd, struct link_map *m)
3141{
8301820e
JM
3142 /*
3143 * The following is a hack to force the compiler to emit calls to
3144 * this function, even when optimizing. If the function is empty,
3145 * the compiler is not obliged to emit any code for calls to it,
3146 * even when marked __noinline. However, gdb depends on those
3147 * calls being made.
3148 */
3149 __asm __volatile("" : : : "memory");
984263bc
MD
3150}
3151
3152/*
3153 * Get address of the pointer variable in the main program.
153ab392 3154 * Prefer non-weak symbol over the weak one.
984263bc
MD
3155 */
3156static const void **
153ab392 3157get_program_var_addr(const char *name, RtldLockState *lockstate)
984263bc 3158{
35b2b265 3159 SymLook req;
153ab392 3160 DoneList donelist;
984263bc 3161
35b2b265 3162 symlook_init(&req, name);
153ab392
JM
3163 req.lockstate = lockstate;
3164 donelist_init(&donelist);
3165 if (symlook_global(&req, &donelist) != 0)
3166 return (NULL);
3167 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC)
3168 return ((const void **)make_function_pointer(req.sym_out,
3169 req.defobj_out));
0e63a289
JM
3170 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC)
3171 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out));
153ab392 3172 else
35b2b265
JM
3173 return ((const void **)(req.defobj_out->relocbase +
3174 req.sym_out->st_value));
984263bc
MD
3175}
3176
3177/*
3178 * Set a pointer variable in the main program to the given value. This
3179 * is used to set key variables such as "environ" before any of the
3180 * init functions are called.
3181 */
3182static void
3183set_program_var(const char *name, const void *value)
3184{
3185 const void **addr;
3186
153ab392 3187 if ((addr = get_program_var_addr(name, NULL)) != NULL) {
984263bc
MD
3188 dbg("\"%s\": *%p <-- %p", name, addr, value);
3189 *addr = value;
3190 }
3191}
3192
153ab392
JM
3193/*
3194 * Search the global objects, including dependencies and main object,
3195 * for the given symbol.
3196 */
3197static int
3198symlook_global(SymLook *req, DoneList *donelist)
3199{
3200 SymLook req1;
3201 const Objlist_Entry *elm;
3202 int res;
3203
3204 symlook_init_from_req(&req1, req);
3205
3206 /* Search all objects loaded at program start up. */
3207 if (req->defobj_out == NULL ||
3208 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
3209 res = symlook_list(&req1, &list_main, donelist);
3210 if (res == 0 && (req->defobj_out == NULL ||
3211 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3212 req->sym_out = req1.sym_out;
3213 req->defobj_out = req1.defobj_out;
3214 assert(req->defobj_out != NULL);
3215 }
3216 }
3217
3218 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
3219 STAILQ_FOREACH(elm, &list_global, link) {
3220 if (req->defobj_out != NULL &&
3221 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
3222 break;
3223 res = symlook_list(&req1, &elm->obj->dagmembers, donelist);
3224 if (res == 0 && (req->defobj_out == NULL ||
3225 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3226 req->sym_out = req1.sym_out;
3227 req->defobj_out = req1.defobj_out;
3228 assert(req->defobj_out != NULL);
3229 }
3230 }
3231
3232 return (req->sym_out != NULL ? 0 : ESRCH);
3233}
3234
8ca15ec8
MD
3235/*
3236 * This is a special version of getenv which is far more efficient
3237 * at finding LD_ environment vars.
3238 */
3239static
3240const char *
3241_getenv_ld(const char *id)
3242{
3243 const char *envp;
3244 int i, j;
3245 int idlen = strlen(id);
3246
3247 if (ld_index == LD_ARY_CACHE)
3248 return(getenv(id));
3249 if (ld_index == 0) {
3250 for (i = j = 0; (envp = environ[i]) != NULL && j < LD_ARY_CACHE; ++i) {
3251 if (envp[0] == 'L' && envp[1] == 'D' && envp[2] == '_')
3252 ld_ary[j++] = envp;
3253 }
3254 if (j == 0)
3255 ld_ary[j++] = "";
3256 ld_index = j;
3257 }
3258 for (i = ld_index - 1; i >= 0; --i) {
3259 if (strncmp(ld_ary[i], id, idlen) == 0 && ld_ary[i][idlen] == '=')
3260 return(ld_ary[i] + idlen + 1);
3261 }
3262 return(NULL);
3263}
3264
984263bc
MD
3265/*
3266 * Given a symbol name in a referencing object, find the corresponding
3267 * definition of the symbol. Returns a pointer to the symbol, or NULL if
3268 * no definition was found. Returns a pointer to the Obj_Entry of the
3269 * defining object via the reference parameter DEFOBJ_OUT.
3270 */
35b2b265
JM
3271static int
3272symlook_default(SymLook *req, const Obj_Entry *refobj)
984263bc
MD
3273{
3274 DoneList donelist;
984263bc 3275 const Objlist_Entry *elm;
35b2b265
JM
3276 SymLook req1;
3277 int res;
153ab392 3278
984263bc 3279 donelist_init(&donelist);
35b2b265 3280 symlook_init_from_req(&req1, req);
984263bc
MD
3281
3282 /* Look first in the referencing object if linked symbolically. */
3283 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
35b2b265
JM
3284 res = symlook_obj(&req1, refobj);
3285 if (res == 0) {
153ab392
JM
3286 req->sym_out = req1.sym_out;
3287 req->defobj_out = req1.defobj_out;
3288 assert(req->defobj_out != NULL);
984263bc
MD
3289 }
3290 }
3291
153ab392 3292 symlook_global(req, &donelist);
984263bc
MD
3293
3294 /* Search all dlopened DAGs containing the referencing object. */
3295 STAILQ_FOREACH(elm, &refobj->dldags, link) {
153ab392
JM
3296 if (req->sym_out != NULL &&
3297 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
984263bc 3298 break;
35b2b265 3299 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist);
153ab392
JM
3300 if (res == 0 && (req->sym_out == NULL ||
3301 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3302 req->sym_out = req1.sym_out;
3303 req->defobj_out = req1.defobj_out;
3304 assert(req->defobj_out != NULL);
984263bc
MD
3305 }
3306 }
3307
3308 /*
3309 * Search the dynamic linker itself, and possibly resolve the
3310 * symbol from there. This is how the application links to
3311 * dynamic linker services such as dlopen. Only the values listed
3312 * in the "exports" array can be resolved from the dynamic linker.
3313 */
153ab392
JM
3314 if (req->sym_out == NULL ||
3315 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
35b2b265
JM
3316 res = symlook_obj(&req1, &obj_rtld);
3317 if (res == 0 && is_exported(req1.sym_out)) {
153ab392
JM
3318 req->sym_out = req1.sym_out;
3319 req->defobj_out = req1.defobj_out;
3320 assert(req->defobj_out != NULL);
984263bc
MD
3321 }
3322 }
3323
153ab392 3324 return (req->sym_out != NULL ? 0 : ESRCH);
984263bc
MD
3325}
3326
35b2b265
JM
3327static int
3328symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp)
984263bc 3329{
984263bc
MD
3330 const Elf_Sym *def;
3331 const Obj_Entry *defobj;
3332 const Objlist_Entry *elm;
35b2b265
JM
3333 SymLook req1;
3334 int res;
984263bc
MD
3335
3336 def = NULL;
3337 defobj = NULL;
3338 STAILQ_FOREACH(elm, objlist, link) {
3339 if (donelist_check(dlp, elm->obj))
3340 continue;
35b2b265
JM
3341 symlook_init_from_req(&req1, req);
3342 if ((res = symlook_obj(&req1, elm->obj)) == 0) {
3343 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
3344 def = req1.sym_out;
3345 defobj = req1.defobj_out;
984263bc
MD
3346 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3347 break;
3348 }
3349 }
3350 }
35b2b265
JM
3351 if (def != NULL) {
3352 req->sym_out = def;
3353 req->defobj_out = defobj;
3354 return (0);
3355 }
3356 return (ESRCH);
984263bc
MD
3357}
3358
cebaf0af 3359/*
153ab392
JM
3360 * Search the chain of DAGS cointed to by the given Needed_Entry
3361 * for a symbol of the given name. Each DAG is scanned completely
3362 * before advancing to the next one. Returns a pointer to the symbol,
3363 * or NULL if no definition was found.
cebaf0af 3364 */
35b2b265
JM
3365static int
3366symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp)
cebaf0af 3367{
153ab392 3368 const Elf_Sym *def;
cebaf0af 3369 const Needed_Entry *n;
153ab392 3370 const Obj_Entry *defobj;
35b2b265
JM
3371 SymLook req1;
3372 int res;
fcf53d9b 3373
153ab392 3374 def = NULL;
cebaf0af 3375 defobj = NULL;
35b2b265 3376 symlook_init_from_req(&req1, req);
cebaf0af 3377 for (n = needed; n != NULL; n = n->next) {
153ab392
JM
3378 if (n->obj == NULL ||
3379 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0)
fcf53d9b 3380 continue;
153ab392 3381 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
35b2b265
JM
3382 def = req1.sym_out;
3383 defobj = req1.defobj_out;
153ab392
JM
3384 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3385 break;
fcf53d9b 3386 }
cebaf0af 3387 }
35b2b265
JM
3388 if (def != NULL) {
3389 req->sym_out = def;
3390 req->defobj_out = defobj;
3391 return (0);
3392 }
3393 return (ESRCH);
cebaf0af
SS
3394}
3395
984263bc
MD
3396/*
3397 * Search the symbol table of a single shared object for a symbol of
fcf53d9b 3398 * the given name and version, if requested. Returns a pointer to the
35b2b265
JM
3399 * symbol, or NULL if no definition was found. If the object is
3400 * filter, return filtered symbol from filtee.
984263bc
MD
3401 *
3402 * The symbol's hash value is passed in for efficiency reasons; that
3403 * eliminates many recomputations of the hash value.
3404 */
35b2b265
JM
3405int
3406symlook_obj(SymLook *req, const Obj_Entry *obj)
3407{
3408 DoneList donelist;
3409 SymLook req1;
3410 int res, mres;
3411
3412 mres = symlook_obj1(req, obj);
3413 if (mres == 0) {
3414 if (obj->needed_filtees != NULL) {
3415 load_filtees(__DECONST(Obj_Entry *, obj), 0, req->lockstate);
3416 donelist_init(&donelist);
3417 symlook_init_from_req(&req1, req);
3418 res = symlook_needed(&req1, obj->needed_filtees, &donelist);
3419 if (res == 0) {
3420 req->sym_out = req1.sym_out;
3421 req->defobj_out = req1.defobj_out;
3422 }
3423 return (res);
3424 }
3425 if (obj->needed_aux_filtees != NULL) {
3426 load_filtees(__DECONST(Obj_Entry *, obj), 0, req->lockstate);
3427 donelist_init(&donelist);
3428 symlook_init_from_req(&req1, req);
3429 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist);
3430 if (res == 0) {
3431 req->sym_out = req1.sym_out;
3432 req->defobj_out = req1.defobj_out;
3433 return (res);
3434 }
3435 }
3436 }
3437 return (mres);
3438}
3439
3440static int
3441symlook_obj1(SymLook *req, const Obj_Entry *obj)
984263bc 3442{
fcf53d9b
JM
3443 unsigned long symnum;
3444 const Elf_Sym *vsymp;
3445 Elf_Versym verndx;
3446 int vcount;
984263bc 3447
fcf53d9b 3448 if (obj->buckets == NULL)
35b2b265 3449 return (ESRCH);
984263bc 3450
fcf53d9b
JM
3451 vsymp = NULL;
3452 vcount = 0;
35b2b265 3453 symnum = obj->buckets[req->hash % obj->nbuckets];
fcf53d9b
JM
3454
3455 for (; symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
3456 const Elf_Sym *symp;
3457 const char *strp;
3458
3459 if (symnum >= obj->nchains)
35b2b265 3460 return (ESRCH); /* Bad object */
fcf53d9b
JM
3461
3462 symp = obj->symtab + symnum;
3463 strp = obj->strtab + symp->st_name;
3464
3465 switch (ELF_ST_TYPE(symp->st_info)) {
3466 case STT_FUNC:
3467 case STT_NOTYPE:
3468 case STT_OBJECT:
0e63a289 3469 case STT_GNU_IFUNC:
fcf53d9b
JM
3470 if (symp->st_value == 0)
3471 continue;
3472 /* fallthrough */
3473 case STT_TLS:
3474 if (symp->st_shndx != SHN_UNDEF)
3475 break;
35b2b265 3476 else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
fcf53d9b
JM
3477 (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
3478 break;
3479 /* fallthrough */
3480 default:
3481 continue;
3482 }
35b2b265 3483 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0)
fcf53d9b 3484 continue;
984263bc 3485
35b2b265 3486 if (req->ventry == NULL) {
fcf53d9b
JM
3487 if (obj->versyms != NULL) {
3488 verndx = VER_NDX(obj->versyms[symnum]);
3489 if (verndx > obj->vernum) {
3490 _rtld_error("%s: symbol %s references wrong version %d",
3491 obj->path, obj->strtab + symnum, verndx);
3492 continue;
3493 }
3494 /*
3495 * If we are not called from dlsym (i.e. this is a normal
3496 * relocation from unversioned binary), accept the symbol
3497 * immediately if it happens to have first version after
3498 * this shared object became versioned. Otherwise, if
3499 * symbol is versioned and not hidden, remember it. If it
3500 * is the only symbol with this name exported by the
3501 * shared object, it will be returned as a match at the
3502 * end of the function. If symbol is global (verndx < 2)
3503 * accept it unconditionally.
3504 */
35b2b265
JM
3505 if ((req->flags & SYMLOOK_DLSYM) == 0 &&
3506 verndx == VER_NDX_GIVEN) {
3507 req->sym_out = symp;
3508 req->defobj_out = obj;
3509 return (0);
3510 }
fcf53d9b
JM
3511 else if (verndx >= VER_NDX_GIVEN) {
3512 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) {
3513 if (vsymp == NULL)
3514 vsymp = symp;
3515 vcount ++;
3516 }
3517 continue;
3518 }
3519 }
35b2b265
JM
3520 req->sym_out = symp;
3521 req->defobj_out = obj;
3522 return (0);
fcf53d9b
JM
3523 } else {
3524 if (obj->versyms == NULL) {
35b2b265 3525 if (object_match_name(obj, req->ventry->name)) {
fcf53d9b 3526 _rtld_error("%s: object %s should provide version %s for "
35b2b265
JM
3527 "symbol %s", obj_rtld.path, obj->path,
3528 req->ventry->name, obj->strtab + symnum);
fcf53d9b
JM
3529 continue;
3530 }
3531 } else {
3532 verndx = VER_NDX(obj->versyms[symnum]);
3533 if (verndx > obj->vernum) {
3534 _rtld_error("%s: symbol %s references wrong version %d",
3535 obj->path, obj->strtab + symnum, verndx);
3536 continue;
3537 }
35b2b265
JM
3538 if (obj->vertab[verndx].hash != req->ventry->hash ||
3539 strcmp(obj->vertab[verndx].name, req->ventry->name)) {
fcf53d9b
JM
3540 /*
3541 * Version does not match. Look if this is a global symbol
3542 * and if it is not hidden. If global symbol (verndx < 2)
3543 * is available, use it. Do not return symbol if we are
3544 * called by dlvsym, because dlvsym looks for a specific
3545 * version and default one is not what dlvsym wants.
3546 */
35b2b265 3547 if ((req->flags & SYMLOOK_DLSYM) ||
fcf53d9b
JM
3548 (obj->versyms[symnum] & VER_NDX_HIDDEN) ||
3549 (verndx >= VER_NDX_GIVEN))
3550 continue;
3551 }
3552 }
35b2b265
JM
3553 req->sym_out = symp;
3554 req->defobj_out = obj;
3555 return (0);
984263bc
MD
3556 }
3557 }
35b2b265
JM
3558 if (vcount == 1) {
3559 req->sym_out = vsymp;
3560 req->defobj_out = obj;
3561 return (0);
3562 }
3563 return (ESRCH);
984263bc
MD
3564}
3565
3566static void
3567trace_loaded_objects(Obj_Entry *obj)
3568{
fcf53d9b 3569 const char *fmt1, *fmt2, *fmt, *main_local, *list_containers;
984263bc
MD
3570 int c;
3571
8ca15ec8 3572 if ((main_local = _getenv_ld("LD_TRACE_LOADED_OBJECTS_PROGNAME")) == NULL)
984263bc
MD
3573 main_local = "";
3574
8ca15ec8 3575 if ((fmt1 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT1")) == NULL)
984263bc
MD
3576 fmt1 = "\t%o => %p (%x)\n";
3577
8ca15ec8 3578 if ((fmt2 = _getenv_ld("LD_TRACE_LOADED_OBJECTS_FMT2")) == NULL)
984263bc
MD
3579 fmt2 = "\t%o (%x)\n";
3580
fcf53d9b
JM
3581 list_containers = _getenv_ld("LD_TRACE_LOADED_OBJECTS_ALL");
3582
984263bc
MD
3583 for (; obj; obj = obj->next) {
3584 Needed_Entry *needed;
3585 char *name, *path;
3586 bool is_lib;
3587
fcf53d9b 3588 if (list_containers && obj->needed != NULL)
abfcd5b1 3589 rtld_printf("%s:\n", obj->path);
984263bc
MD
3590 for (needed = obj->needed; needed; needed = needed->next) {
3591 if (needed->obj != NULL) {
fcf53d9b 3592 if (needed->obj->traced && !list_containers)
984263bc
MD
3593 continue;
3594 needed->obj->traced = true;
3595 path = needed->obj->path;
3596 } else
3597 path = "not found";
3598
3599 name = (char *)obj->strtab + needed->name;
3600 is_lib = strncmp(name, "lib", 3) == 0; /* XXX - bogus */
3601
3602 fmt = is_lib ? fmt1 : fmt2;
3603 while ((c = *fmt++) != '\0') {
3604 switch (c) {
3605 default:
abfcd5b1 3606 rtld_putchar(c);
984263bc
MD
3607 continue;
3608 case '\\':
3609 switch (c = *fmt) {
3610 case '\0':
3611 continue;
3612 case 'n':
abfcd5b1 3613 rtld_putchar('\n');
984263bc
MD
3614 break;
3615 case 't':
abfcd5b1 3616 rtld_putchar('\t');
984263bc
MD
3617 break;
3618 }
3619 break;
3620 case '%':
3621 switch (c = *fmt) {
3622 case '\0':
3623 continue;
3624 case '%':
3625 default:
abfcd5b1 3626