ELF: Update header, sync with binutils 2.22
[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>.
7629c631 5 * Copyright 2012 John Marino <draco@marino.st>.
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6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
f4f4bfd5 28 * $FreeBSD$
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29 */
30
31/*
32 * Dynamic linker for ELF.
33 *
34 * John Polstra <jdp@polstra.com>.
35 */
36
37#ifndef __GNUC__
38#error "GCC is needed to compile this file"
39#endif
40
41#include <sys/param.h>
fcf53d9b 42#include <sys/mount.h>
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43#include <sys/mman.h>
44#include <sys/stat.h>
b566341b 45#include <sys/sysctl.h>
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46#include <sys/uio.h>
47#include <sys/utsname.h>
48#include <sys/ktrace.h>
8ca15ec8 49#include <sys/resident.h>
bc633d63 50#include <sys/tls.h>
984263bc 51
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52#include <machine/tls.h>
53
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54#include <dlfcn.h>
55#include <err.h>
56#include <errno.h>
57#include <fcntl.h>
58#include <stdarg.h>
59#include <stdio.h>
60#include <stdlib.h>
61#include <string.h>
62#include <unistd.h>
63
64#include "debug.h"
65#include "rtld.h"
fcf53d9b 66#include "libmap.h"
abfcd5b1 67#include "rtld_printf.h"
7f5c8f97 68#include "notes.h"
984263bc 69
a1eee96a 70#define PATH_RTLD "/usr/libexec/ld-elf.so.2"
8ca15ec8 71#define LD_ARY_CACHE 16
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72
73/* Types. */
74typedef void (*func_ptr_type)();
75typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
76
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77/*
78 * Function declarations.
79 */
8ca15ec8 80static const char *_getenv_ld(const char *id);
fcf53d9b 81static void die(void) __dead2;
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82static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
83 const Elf_Dyn **);
84static void digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *);
fcf53d9b 85static void digest_dynamic(Obj_Entry *, int);
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86static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
87static Obj_Entry *dlcheck(void *);
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88static Obj_Entry *dlopen_object(const char *name, Obj_Entry *refobj,
89 int lo_flags, int mode);
fcf53d9b 90static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
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91static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
92static bool donelist_check(DoneList *, const Obj_Entry *);
93static void errmsg_restore(char *);
94static char *errmsg_save(void);
95static void *fill_search_info(const char *, size_t, void *);
96static char *find_library(const char *, const Obj_Entry *);
97static const char *gethints(void);
98static void init_dag(Obj_Entry *);
b566341b 99static void init_rtld(caddr_t, Elf_Auxinfo **);
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100static void initlist_add_neededs(Needed_Entry *, Objlist *);
101static void initlist_add_objects(Obj_Entry *, Obj_Entry **, Objlist *);
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102static bool is_exported(const Elf_Sym *);
103static void linkmap_add(Obj_Entry *);
104static void linkmap_delete(Obj_Entry *);
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105static void load_filtees(Obj_Entry *, int flags, RtldLockState *);
106static void unload_filtees(Obj_Entry *);
fcf53d9b 107static int load_needed_objects(Obj_Entry *, int);
984263bc 108static int load_preload_objects(void);
fcf53d9b 109static Obj_Entry *load_object(const char *, const Obj_Entry *, int);
e9de6dcc 110static void map_stacks_exec(RtldLockState *);
984263bc 111static Obj_Entry *obj_from_addr(const void *);
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112static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
113static void objlist_call_init(Objlist *, RtldLockState *);
b28bf640 114static void preinitialize_main_object (void);
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115static void objlist_clear(Objlist *);
116static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
117static void objlist_init(Objlist *);
118static void objlist_push_head(Objlist *, Obj_Entry *);
119static void objlist_push_tail(Objlist *, Obj_Entry *);
120static void objlist_remove(Objlist *, Obj_Entry *);
984263bc 121static void *path_enumerate(const char *, path_enum_proc, void *);
35b2b265 122static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, RtldLockState *);
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123static int resolve_objects_ifunc(Obj_Entry *first, bool bind_now,
124 RtldLockState *lockstate);
984263bc 125static int rtld_dirname(const char *, char *);
fcf53d9b 126static int rtld_dirname_abs(const char *, char *);
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127static void rtld_exit(void);
128static char *search_library_path(const char *, const char *);
153ab392 129static const void **get_program_var_addr(const char *, RtldLockState *);
984263bc 130static void set_program_var(const char *, const void *);
35b2b265 131static int symlook_default(SymLook *, const Obj_Entry *refobj);
153ab392 132static int symlook_global(SymLook *, DoneList *);
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133static void symlook_init_from_req(SymLook *, const SymLook *);
134static int symlook_list(SymLook *, const Objlist *, DoneList *);
135static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *);
136static int symlook_obj1(SymLook *, const Obj_Entry *);
7629c631 137static int symlook_obj2(SymLook *, const Obj_Entry *);
fcf53d9b 138static void trace_loaded_objects(Obj_Entry *);
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139static void unlink_object(Obj_Entry *);
140static void unload_object(Obj_Entry *);
141static void unref_dag(Obj_Entry *);
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142static void ref_dag(Obj_Entry *);
143static int origin_subst_one(char **, const char *, const char *,
144 const char *, char *);
145static char *origin_subst(const char *, const char *);
146static int rtld_verify_versions(const Objlist *);
147static int rtld_verify_object_versions(Obj_Entry *);
148static void object_add_name(Obj_Entry *, const char *);
149static int object_match_name(const Obj_Entry *, const char *);
150static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
151static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
152 struct dl_phdr_info *phdr_info);
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153static uint_fast32_t gnu_hash (const char *);
154static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *,
155 const unsigned long);
fcf53d9b 156
8301820e 157void r_debug_state(struct r_debug *, struct link_map *) __noinline;
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158
159/*
160 * Data declarations.
161 */
162static char *error_message; /* Message for dlerror(), or NULL */
163struct r_debug r_debug; /* for GDB; */
fcf53d9b 164static bool libmap_disable; /* Disable libmap */
35b2b265 165static bool ld_loadfltr; /* Immediate filters processing */
fcf53d9b 166static char *libmap_override; /* Maps to use in addition to libmap.conf */
984263bc 167static bool trust; /* False for setuid and setgid programs */
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168static bool dangerous_ld_env; /* True if environment variables have been
169 used to affect the libraries loaded */
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170static const char *ld_bind_now; /* Environment variable for immediate binding */
171static const char *ld_debug; /* Environment variable for debugging */
172static const char *ld_library_path; /* Environment variable for search path */
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173static char *ld_preload; /* Environment variable for libraries to
174 load first */
fcf53d9b 175static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */
b566341b 176static const char *ld_tracing; /* Called from ldd to print libs */
fcf53d9b 177static const char *ld_utrace; /* Use utrace() to log events. */
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178static int (*rtld_functrace)( /* Optional function call tracing hook */
179 const char *caller_obj,
180 const char *callee_obj,
181 const char *callee_func,
182 void *stack);
35b2b265 183static const Obj_Entry *rtld_functrace_obj; /* Object thereof */
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184static Obj_Entry *obj_list; /* Head of linked list of shared objects */
185static Obj_Entry **obj_tail; /* Link field of last object in list */
8ca15ec8 186static Obj_Entry **preload_tail;
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187static Obj_Entry *obj_main; /* The main program shared object */
188static Obj_Entry obj_rtld; /* The dynamic linker shared object */
189static unsigned int obj_count; /* Number of objects in obj_list */
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190static unsigned int obj_loads; /* Number of objects in obj_list */
191
33a8b578 192static int ld_resident; /* Non-zero if resident */
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193static const char *ld_ary[LD_ARY_CACHE];
194static int ld_index;
a1eee96a 195static Objlist initlist;
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196
197static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
198 STAILQ_HEAD_INITIALIZER(list_global);
199static Objlist list_main = /* Objects loaded at program startup */
200 STAILQ_HEAD_INITIALIZER(list_main);
201static Objlist list_fini = /* Objects needing fini() calls */
202 STAILQ_HEAD_INITIALIZER(list_fini);
203
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204static Elf_Sym sym_zero; /* For resolving undefined weak refs. */
205
206#define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
207
208extern Elf_Dyn _DYNAMIC;
209#pragma weak _DYNAMIC
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210#ifndef RTLD_IS_DYNAMIC
211#define RTLD_IS_DYNAMIC() (&_DYNAMIC != NULL)
212#endif
984263bc 213
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214#ifdef ENABLE_OSRELDATE
215int osreldate;
216#endif
217
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218static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC;
219static int max_stack_flags;
220
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221/*
222 * These are the functions the dynamic linker exports to application
223 * programs. They are the only symbols the dynamic linker is willing
224 * to export from itself.
225 */
226static func_ptr_type exports[] = {
227 (func_ptr_type) &_rtld_error,
228 (func_ptr_type) &dlclose,
229 (func_ptr_type) &dlerror,
230 (func_ptr_type) &dlopen,
fcf53d9b 231 (func_ptr_type) &dlfunc,
984263bc 232 (func_ptr_type) &dlsym,
fcf53d9b 233 (func_ptr_type) &dlvsym,
984263bc 234 (func_ptr_type) &dladdr,
984263bc 235 (func_ptr_type) &dlinfo,
fcf53d9b 236 (func_ptr_type) &dl_iterate_phdr,
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237#ifdef __i386__
238 (func_ptr_type) &___tls_get_addr,
239#endif
240 (func_ptr_type) &__tls_get_addr,
a1eee96a 241 (func_ptr_type) &__tls_get_addr_tcb,
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242 (func_ptr_type) &_rtld_allocate_tls,
243 (func_ptr_type) &_rtld_free_tls,
a1eee96a 244 (func_ptr_type) &_rtld_call_init,
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245 (func_ptr_type) &_rtld_thread_init,
246 (func_ptr_type) &_rtld_addr_phdr,
e9de6dcc 247 (func_ptr_type) &_rtld_get_stack_prot,
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248 NULL
249};
250
251/*
252 * Global declarations normally provided by crt1. The dynamic linker is
253 * not built with crt1, so we have to provide them ourselves.
254 */
255char *__progname;
256char **environ;
257
b28bf640 258/*
7f5c8f97 259 * Used to pass argc, argv to init functions.
b28bf640 260 */
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261int main_argc;
262char **main_argv;
b28bf640 263
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264/*
265 * Globals to control TLS allocation.
266 */
267size_t tls_last_offset; /* Static TLS offset of last module */
268size_t tls_last_size; /* Static TLS size of last module */
269size_t tls_static_space; /* Static TLS space allocated */
270int tls_dtv_generation = 1; /* Used to detect when dtv size changes */
271int tls_max_index = 1; /* Largest module index allocated */
272
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273/*
274 * Fill in a DoneList with an allocation large enough to hold all of
275 * the currently-loaded objects. Keep this as a macro since it calls
276 * alloca and we want that to occur within the scope of the caller.
277 */
278#define donelist_init(dlp) \
279 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
280 assert((dlp)->objs != NULL), \
281 (dlp)->num_alloc = obj_count, \
282 (dlp)->num_used = 0)
283
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284#define UTRACE_DLOPEN_START 1
285#define UTRACE_DLOPEN_STOP 2
286#define UTRACE_DLCLOSE_START 3
287#define UTRACE_DLCLOSE_STOP 4
288#define UTRACE_LOAD_OBJECT 5
289#define UTRACE_UNLOAD_OBJECT 6
290#define UTRACE_ADD_RUNDEP 7
291#define UTRACE_PRELOAD_FINISHED 8
292#define UTRACE_INIT_CALL 9
293#define UTRACE_FINI_CALL 10
294
295struct utrace_rtld {
296 char sig[4]; /* 'RTLD' */
297 int event;
298 void *handle;
299 void *mapbase; /* Used for 'parent' and 'init/fini' */
300 size_t mapsize;
301 int refcnt; /* Used for 'mode' */
302 char name[MAXPATHLEN];
303};
984263bc 304
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305#define LD_UTRACE(e, h, mb, ms, r, n) do { \
306 if (ld_utrace != NULL) \
307 ld_utrace_log(e, h, mb, ms, r, n); \
308} while (0)
984263bc 309
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310static void
311ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
312 int refcnt, const char *name)
313{
314 struct utrace_rtld ut;
315
316 ut.sig[0] = 'R';
317 ut.sig[1] = 'T';
318 ut.sig[2] = 'L';
319 ut.sig[3] = 'D';
320 ut.event = event;
321 ut.handle = handle;
322 ut.mapbase = mapbase;
323 ut.mapsize = mapsize;
324 ut.refcnt = refcnt;
325 bzero(ut.name, sizeof(ut.name));
326 if (name)
327 strlcpy(ut.name, name, sizeof(ut.name));
328 utrace(&ut, sizeof(ut));
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329}
330
331/*
332 * Main entry point for dynamic linking. The first argument is the
333 * stack pointer. The stack is expected to be laid out as described
334 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
335 * Specifically, the stack pointer points to a word containing
336 * ARGC. Following that in the stack is a null-terminated sequence
337 * of pointers to argument strings. Then comes a null-terminated
338 * sequence of pointers to environment strings. Finally, there is a
339 * sequence of "auxiliary vector" entries.
340 *
341 * The second argument points to a place to store the dynamic linker's
342 * exit procedure pointer and the third to a place to store the main
343 * program's object.
344 *
345 * The return value is the main program's entry point.
346 */
347func_ptr_type
348_rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
349{
350 Elf_Auxinfo *aux_info[AT_COUNT];
351 int i;
352 int argc;
353 char **argv;
354 char **env;
355 Elf_Auxinfo *aux;
356 Elf_Auxinfo *auxp;
357 const char *argv0;
55b88cae 358 Objlist_Entry *entry;
984263bc 359 Obj_Entry *obj;
984263bc 360
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361 /* marino: DO NOT MOVE THESE VARIABLES TO _rtld
362 Obj_Entry **preload_tail;
363 Objlist initlist;
35b2b265 364 from global to here. It will break the DWARF2 unwind scheme.
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365 The system compilers were unaffected, but not gcc 4.6
366 */
367
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368 /*
369 * On entry, the dynamic linker itself has not been relocated yet.
370 * Be very careful not to reference any global data until after
371 * init_rtld has returned. It is OK to reference file-scope statics
372 * and string constants, and to call static and global functions.
373 */
374
375 /* Find the auxiliary vector on the stack. */
376 argc = *sp++;
377 argv = (char **) sp;
378 sp += argc + 1; /* Skip over arguments and NULL terminator */
379 env = (char **) sp;
984263bc 380
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381 /*
382 * If we aren't already resident we have to dig out some more info.
383 * Note that auxinfo does not exist when we are resident.
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384 *
385 * I'm not sure about the ld_resident check. It seems to read zero
386 * prior to relocation, which is what we want. When running from a
387 * resident copy everything will be relocated so we are definitely
388 * good there.
33a8b578 389 */
5347affc 390 if (ld_resident == 0) {
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MD
391 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
392 ;
393 aux = (Elf_Auxinfo *) sp;
394
395 /* Digest the auxiliary vector. */
396 for (i = 0; i < AT_COUNT; i++)
397 aux_info[i] = NULL;
398 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
399 if (auxp->a_type < AT_COUNT)
400 aux_info[auxp->a_type] = auxp;
401 }
402
403 /* Initialize and relocate ourselves. */
404 assert(aux_info[AT_BASE] != NULL);
b566341b 405 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
33a8b578 406 }
984263bc 407
5347affc 408 ld_index = 0; /* don't use old env cache in case we are resident */
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409 __progname = obj_rtld.path;
410 argv0 = argv[0] != NULL ? argv[0] : "(null)";
411 environ = env;
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412 main_argc = argc;
413 main_argv = argv;
984263bc 414
fcf53d9b 415 trust = !issetugid();
984263bc 416
8ca15ec8 417 ld_bind_now = _getenv_ld("LD_BIND_NOW");
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418 /*
419 * If the process is tainted, then we un-set the dangerous environment
420 * variables. The process will be marked as tainted until setuid(2)
421 * is called. If any child process calls setuid(2) we do not want any
422 * future processes to honor the potentially un-safe variables.
423 */
424 if (!trust) {
425 if ( unsetenv("LD_DEBUG")
426 || unsetenv("LD_PRELOAD")
427 || unsetenv("LD_LIBRARY_PATH")
428 || unsetenv("LD_ELF_HINTS_PATH")
429 || unsetenv("LD_LIBMAP")
430 || unsetenv("LD_LIBMAP_DISABLE")
35b2b265 431 || unsetenv("LD_LOADFLTR")
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432 ) {
433 _rtld_error("environment corrupt; aborting");
434 die();
435 }
984263bc 436 }
fcf53d9b 437 ld_debug = _getenv_ld("LD_DEBUG");
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438 libmap_disable = _getenv_ld("LD_LIBMAP_DISABLE") != NULL;
439 libmap_override = (char *)_getenv_ld("LD_LIBMAP");
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440 ld_library_path = _getenv_ld("LD_LIBRARY_PATH");
441 ld_preload = (char *)_getenv_ld("LD_PRELOAD");
442 ld_elf_hints_path = _getenv_ld("LD_ELF_HINTS_PATH");
35b2b265 443 ld_loadfltr = _getenv_ld("LD_LOADFLTR") != NULL;
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444 dangerous_ld_env = (ld_library_path != NULL)
445 || (ld_preload != NULL)
446 || (ld_elf_hints_path != NULL)
35b2b265 447 || ld_loadfltr
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448 || (libmap_override != NULL)
449 || libmap_disable
450 ;
8ca15ec8 451 ld_tracing = _getenv_ld("LD_TRACE_LOADED_OBJECTS");
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452 ld_utrace = _getenv_ld("LD_UTRACE");
453
454 if ((ld_elf_hints_path == NULL) || strlen(ld_elf_hints_path) == 0)
455 ld_elf_hints_path = _PATH_ELF_HINTS;
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456
457 if (ld_debug != NULL && *ld_debug != '\0')
458 debug = 1;
459 dbg("%s is initialized, base address = %p", __progname,
460 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
461 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
462 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
463
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464 dbg("initializing thread locks");
465 lockdflt_init();
466
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467 /*
468 * If we are resident we can skip work that we have already done.
469 * Note that the stack is reset and there is no Elf_Auxinfo
470 * when running from a resident image, and the static globals setup
471 * between here and resident_skip will have already been setup.
472 */
8ca15ec8 473 if (ld_resident)
33a8b578 474 goto resident_skip1;
33a8b578 475
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476 /*
477 * Load the main program, or process its program header if it is
478 * already loaded.
479 */
480 if (aux_info[AT_EXECFD] != NULL) { /* Load the main program. */
481 int fd = aux_info[AT_EXECFD]->a_un.a_val;
482 dbg("loading main program");
483 obj_main = map_object(fd, argv0, NULL);
484 close(fd);
485 if (obj_main == NULL)
486 die();
e9de6dcc 487 max_stack_flags = obj->stack_flags;
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488 } else { /* Main program already loaded. */
489 const Elf_Phdr *phdr;
490 int phnum;
491 caddr_t entry;
492
493 dbg("processing main program's program header");
494 assert(aux_info[AT_PHDR] != NULL);
495 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
496 assert(aux_info[AT_PHNUM] != NULL);
497 phnum = aux_info[AT_PHNUM]->a_un.a_val;
498 assert(aux_info[AT_PHENT] != NULL);
499 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
500 assert(aux_info[AT_ENTRY] != NULL);
501 entry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
502 if ((obj_main = digest_phdr(phdr, phnum, entry, argv0)) == NULL)
503 die();
504 }
505
fcf53d9b 506 char buf[MAXPATHLEN];
678e8cc6 507 if (aux_info[AT_EXECPATH] != NULL) {
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508 char *kexecpath;
509
510 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
511 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
512 if (kexecpath[0] == '/')
513 obj_main->path = kexecpath;
514 else if (getcwd(buf, sizeof(buf)) == NULL ||
515 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
516 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
517 obj_main->path = xstrdup(argv0);
518 else
519 obj_main->path = xstrdup(buf);
520 } else {
521 char resolved[MAXPATHLEN];
522 dbg("No AT_EXECPATH");
523 if (argv0[0] == '/') {
524 if (realpath(argv0, resolved) != NULL)
525 obj_main->path = xstrdup(resolved);
526 else
527 obj_main->path = xstrdup(argv0);
528 } else {
529 if (getcwd(buf, sizeof(buf)) != NULL
530 && strlcat(buf, "/", sizeof(buf)) < sizeof(buf)
531 && strlcat(buf, argv0, sizeof (buf)) < sizeof(buf)
532 && access(buf, R_OK) == 0
533 && realpath(buf, resolved) != NULL)
534 obj_main->path = xstrdup(resolved);
535 else
536 obj_main->path = xstrdup(argv0);
537 }
538 }
539 dbg("obj_main path %s", obj_main->path);
984263bc
MD
540 obj_main->mainprog = true;
541
e9de6dcc
JM
542 if (aux_info[AT_STACKPROT] != NULL &&
543 aux_info[AT_STACKPROT]->a_un.a_val != 0)
544 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val;
545
984263bc
MD
546 /*
547 * Get the actual dynamic linker pathname from the executable if
548 * possible. (It should always be possible.) That ensures that
549 * gdb will find the right dynamic linker even if a non-standard
550 * one is being used.
551 */
552 if (obj_main->interp != NULL &&
553 strcmp(obj_main->interp, obj_rtld.path) != 0) {
554 free(obj_rtld.path);
555 obj_rtld.path = xstrdup(obj_main->interp);
b7b05c9f 556 __progname = obj_rtld.path;
984263bc
MD
557 }
558
c3098c28 559 digest_dynamic(obj_main, 0);
984263bc
MD
560
561 linkmap_add(obj_main);
562 linkmap_add(&obj_rtld);
563
564 /* Link the main program into the list of objects. */
565 *obj_tail = obj_main;
566 obj_tail = &obj_main->next;
567 obj_count++;
fcf53d9b 568 obj_loads++;
984263bc
MD
569
570 /* Initialize a fake symbol for resolving undefined weak references. */
571 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
fcf53d9b
JM
572 sym_zero.st_shndx = SHN_UNDEF;
573 sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
574
575 if (!libmap_disable)
576 libmap_disable = (bool)lm_init(libmap_override);
984263bc
MD
577
578 dbg("loading LD_PRELOAD libraries");
579 if (load_preload_objects() == -1)
580 die();
581 preload_tail = obj_tail;
582
583 dbg("loading needed objects");
fcf53d9b 584 if (load_needed_objects(obj_main, 0) == -1)
984263bc
MD
585 die();
586
587 /* Make a list of all objects loaded at startup. */
fcf53d9b 588 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc 589 objlist_push_tail(&list_main, obj);
fcf53d9b
JM
590 obj->refcount++;
591 }
592
593 dbg("checking for required versions");
594 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
595 die();
984263bc 596
33a8b578
MD
597resident_skip1:
598
984263bc
MD
599 if (ld_tracing) { /* We're done */
600 trace_loaded_objects(obj_main);
601 exit(0);
602 }
603
33a8b578
MD
604 if (ld_resident) /* XXX clean this up! */
605 goto resident_skip2;
606
fcf53d9b 607 if (_getenv_ld("LD_DUMP_REL_PRE") != NULL) {
4a8d9350
JS
608 dump_relocations(obj_main);
609 exit (0);
610 }
611
55b88cae
DX
612 /* setup TLS for main thread */
613 dbg("initializing initial thread local storage");
614 STAILQ_FOREACH(entry, &list_main, link) {
615 /*
616 * Allocate all the initial objects out of the static TLS
617 * block even if they didn't ask for it.
618 */
619 allocate_tls_offset(entry->obj);
620 }
a1eee96a
MD
621
622 tls_static_space = tls_last_offset + RTLD_STATIC_TLS_EXTRA;
623
624 /*
625 * Do not try to allocate the TLS here, let libc do it itself.
626 * (crt1 for the program will call _init_tls())
627 */
55b88cae 628
6192271e 629 if (relocate_objects(obj_main,
35b2b265 630 ld_bind_now != NULL && *ld_bind_now != '\0', &obj_rtld, NULL) == -1)
6192271e 631 die();
984263bc 632
6192271e
MD
633 dbg("doing copy relocations");
634 if (do_copy_relocations(obj_main) == -1)
635 die();
1c76efe5 636
33a8b578
MD
637resident_skip2:
638
8ca15ec8 639 if (_getenv_ld("LD_RESIDENT_UNREGISTER_NOW")) {
33a8b578
MD
640 if (exec_sys_unregister(-1) < 0) {
641 dbg("exec_sys_unregister failed %d\n", errno);
642 exit(errno);
643 }
644 dbg("exec_sys_unregister success\n");
645 exit(0);
646 }
984263bc 647
fcf53d9b 648 if (_getenv_ld("LD_DUMP_REL_POST") != NULL) {
4a8d9350
JS
649 dump_relocations(obj_main);
650 exit (0);
651 }
652
984263bc
MD
653 dbg("initializing key program variables");
654 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
655 set_program_var("environ", env);
b566341b 656 set_program_var("__elf_aux_vector", aux);
984263bc 657
8ca15ec8
MD
658 if (_getenv_ld("LD_RESIDENT_REGISTER_NOW")) {
659 extern void resident_start(void);
660 ld_resident = 1;
661 if (exec_sys_register(resident_start) < 0) {
662 dbg("exec_sys_register failed %d\n", errno);
663 exit(errno);
664 }
665 dbg("exec_sys_register success\n");
666 exit(0);
667 }
668
984263bc
MD
669 /* Make a list of init functions to call. */
670 objlist_init(&initlist);
671 initlist_add_objects(obj_list, preload_tail, &initlist);
672
673 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
674
e9de6dcc
JM
675 map_stacks_exec(NULL);
676
0e63a289
JM
677 dbg("resolving ifuncs");
678 if (resolve_objects_ifunc(obj_main,
679 ld_bind_now != NULL && *ld_bind_now != '\0', NULL) == -1)
680 die();
681
a1eee96a
MD
682 /*
683 * Do NOT call the initlist here, give libc a chance to set up
684 * the initial TLS segment. crt1 will then call _rtld_call_init().
685 */
8ca15ec8 686
984263bc
MD
687 dbg("transferring control to program entry point = %p", obj_main->entry);
688
689 /* Return the exit procedure and the program entry point. */
690 *exit_proc = rtld_exit;
691 *objp = obj_main;
692 return (func_ptr_type) obj_main->entry;
693}
694
a1eee96a
MD
695/*
696 * Call the initialization list for dynamically loaded libraries.
697 * (called from crt1.c).
698 */
699void
700_rtld_call_init(void)
701{
fcf53d9b 702 RtldLockState lockstate;
35b2b265 703 Obj_Entry *obj;
fcf53d9b 704
e64cf055
JM
705 if (!obj_main->note_present && obj_main->valid_hash_gnu) {
706 /*
707 * The use of a linker script with a PHDRS directive that does not include
708 * PT_NOTE will block the crt_no_init note. In this case we'll look for the
709 * recently added GNU hash dynamic tag which gets built by default. It is
710 * extremely unlikely to find a pre-3.1 binary without a PT_NOTE header and
711 * a gnu hash tag. If gnu hash found, consider binary to use new crt code.
712 */
713 obj_main->crt_no_init = true;
714 dbg("Setting crt_no_init without presence of PT_NOTE header");
715 }
716
fcf53d9b 717 wlock_acquire(rtld_bind_lock, &lockstate);
7f5c8f97
JM
718 if (obj_main->crt_no_init) {
719 preinitialize_main_object();
720 }
721 else {
722 /*
723 * Make sure we don't call the main program's init and fini functions
724 * for binaries linked with old crt1 which calls _init itself.
725 */
726 obj_main->init = obj_main->fini = (Elf_Addr)NULL;
727 obj_main->init_array = obj_main->fini_array = (Elf_Addr)NULL;
728 }
fcf53d9b 729 objlist_call_init(&initlist, &lockstate);
a1eee96a 730 objlist_clear(&initlist);
35b2b265
JM
731 dbg("loading filtees");
732 for (obj = obj_list->next; obj != NULL; obj = obj->next) {
733 if (ld_loadfltr || obj->z_loadfltr)
734 load_filtees(obj, 0, &lockstate);
735 }
fcf53d9b 736 lock_release(rtld_bind_lock, &lockstate);
a1eee96a
MD
737}
738
0e63a289
JM
739void *
740rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def)
741{
742 void *ptr;
743 Elf_Addr target;
744
745 ptr = (void *)make_function_pointer(def, obj);
746 target = ((Elf_Addr (*)(void))ptr)();
747 return ((void *)target);
748}
749
984263bc 750Elf_Addr
4648abf3 751_rtld_bind(Obj_Entry *obj, Elf_Size reloff, void *stack)
984263bc
MD
752{
753 const Elf_Rel *rel;
754 const Elf_Sym *def;
755 const Obj_Entry *defobj;
756 Elf_Addr *where;
757 Elf_Addr target;
fcf53d9b 758 RtldLockState lockstate;
984263bc 759
fcf53d9b
JM
760 rlock_acquire(rtld_bind_lock, &lockstate);
761 if (sigsetjmp(lockstate.env, 0) != 0)
762 lock_upgrade(rtld_bind_lock, &lockstate);
984263bc
MD
763 if (obj->pltrel)
764 rel = (const Elf_Rel *) ((caddr_t) obj->pltrel + reloff);
765 else
766 rel = (const Elf_Rel *) ((caddr_t) obj->pltrela + reloff);
767
768 where = (Elf_Addr *) (obj->relocbase + rel->r_offset);
35b2b265
JM
769 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, NULL,
770 &lockstate);
984263bc
MD
771 if (def == NULL)
772 die();
0e63a289
JM
773 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
774 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
775 else
776 target = (Elf_Addr)(defobj->relocbase + def->st_value);
984263bc
MD
777
778 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
779 defobj->strtab + def->st_name, basename(obj->path),
780 (void *)target, basename(defobj->path));
38e4b3b6
SS
781
782 /*
783 * If we have a function call tracing hook, and the
784 * hook would like to keep tracing this one function,
785 * prevent the relocation so we will wind up here
786 * the next time again.
787 *
788 * We don't want to functrace calls from the functracer
789 * to avoid recursive loops.
790 */
791 if (rtld_functrace != NULL && obj != rtld_functrace_obj) {
792 if (rtld_functrace(obj->path,
793 defobj->path,
794 defobj->strtab + def->st_name,
795 stack))
35b2b265
JM
796 lock_release(rtld_bind_lock, &lockstate);
797 return target;
38e4b3b6
SS
798 }
799
35b2b265
JM
800 /*
801 * Write the new contents for the jmpslot. Note that depending on
802 * architecture, the value which we need to return back to the
803 * lazy binding trampoline may or may not be the target
804 * address. The value returned from reloc_jmpslot() is the value
805 * that the trampoline needs.
806 */
807 target = reloc_jmpslot(where, target, defobj, obj, rel);
fcf53d9b 808 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
809 return target;
810}
811
812/*
813 * Error reporting function. Use it like printf. If formats the message
814 * into a buffer, and sets things up so that the next call to dlerror()
815 * will return the message.
816 */
817void
818_rtld_error(const char *fmt, ...)
819{
820 static char buf[512];
821 va_list ap;
822
823 va_start(ap, fmt);
abfcd5b1 824 rtld_vsnprintf(buf, sizeof buf, fmt, ap);
984263bc
MD
825 error_message = buf;
826 va_end(ap);
827}
828
829/*
830 * Return a dynamically-allocated copy of the current error message, if any.
831 */
832static char *
833errmsg_save(void)
834{
835 return error_message == NULL ? NULL : xstrdup(error_message);
836}
837
838/*
839 * Restore the current error message from a copy which was previously saved
840 * by errmsg_save(). The copy is freed.
841 */
842static void
843errmsg_restore(char *saved_msg)
844{
845 if (saved_msg == NULL)
846 error_message = NULL;
847 else {
848 _rtld_error("%s", saved_msg);
849 free(saved_msg);
850 }
851}
852
1c76efe5 853const char *
984263bc
MD
854basename(const char *name)
855{
856 const char *p = strrchr(name, '/');
857 return p != NULL ? p + 1 : name;
858}
859
fcf53d9b
JM
860static struct utsname uts;
861
862static int
863origin_subst_one(char **res, const char *real, const char *kw, const char *subst,
864 char *may_free)
865{
866 const char *p, *p1;
867 char *res1;
868 int subst_len;
869 int kw_len;
870
871 res1 = *res = NULL;
872 p = real;
873 subst_len = kw_len = 0;
874 for (;;) {
875 p1 = strstr(p, kw);
876 if (p1 != NULL) {
877 if (subst_len == 0) {
878 subst_len = strlen(subst);
879 kw_len = strlen(kw);
880 }
881 if (*res == NULL) {
882 *res = xmalloc(PATH_MAX);
883 res1 = *res;
884 }
885 if ((res1 - *res) + subst_len + (p1 - p) >= PATH_MAX) {
886 _rtld_error("Substitution of %s in %s cannot be performed",
887 kw, real);
888 if (may_free != NULL)
889 free(may_free);
890 free(res);
891 return (false);
892 }
893 memcpy(res1, p, p1 - p);
894 res1 += p1 - p;
895 memcpy(res1, subst, subst_len);
896 res1 += subst_len;
897 p = p1 + kw_len;
898 } else {
899 if (*res == NULL) {
900 if (may_free != NULL)
901 *res = may_free;
902 else
903 *res = xstrdup(real);
904 return (true);
905 }
906 *res1 = '\0';
907 if (may_free != NULL)
908 free(may_free);
909 if (strlcat(res1, p, PATH_MAX - (res1 - *res)) >= PATH_MAX) {
910 free(res);
911 return (false);
912 }
913 return (true);
914 }
915 }
916}
917
918static char *
919origin_subst(const char *real, const char *origin_path)
920{
921 char *res1, *res2, *res3, *res4;
922
923 if (uts.sysname[0] == '\0') {
924 if (uname(&uts) != 0) {
925 _rtld_error("utsname failed: %d", errno);
926 return (NULL);
927 }
928 }
929 if (!origin_subst_one(&res1, real, "$ORIGIN", origin_path, NULL) ||
930 !origin_subst_one(&res2, res1, "$OSNAME", uts.sysname, res1) ||
931 !origin_subst_one(&res3, res2, "$OSREL", uts.release, res2) ||
932 !origin_subst_one(&res4, res3, "$PLATFORM", uts.machine, res3))
933 return (NULL);
934 return (res4);
935}
936
984263bc
MD
937static void
938die(void)
939{
940 const char *msg = dlerror();
941
942 if (msg == NULL)
943 msg = "Fatal error";
abfcd5b1 944 rtld_fdputstr(STDERR_FILENO, msg);
d8eb4093 945 rtld_fdputchar(STDERR_FILENO, '\n');
abfcd5b1 946 _exit(1);
984263bc
MD
947}
948
949/*
950 * Process a shared object's DYNAMIC section, and save the important
951 * information in its Obj_Entry structure.
952 */
953static void
b566341b
JM
954digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
955 const Elf_Dyn **dyn_soname)
984263bc
MD
956{
957 const Elf_Dyn *dynp;
958 Needed_Entry **needed_tail = &obj->needed;
35b2b265
JM
959 Needed_Entry **needed_filtees_tail = &obj->needed_filtees;
960 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees;
984263bc
MD
961 int plttype = DT_REL;
962
b566341b
JM
963 *dyn_rpath = NULL;
964 *dyn_soname = NULL;
965
fcf53d9b 966 obj->bind_now = false;
984263bc
MD
967 for (dynp = obj->dynamic; dynp->d_tag != DT_NULL; dynp++) {
968 switch (dynp->d_tag) {
969
970 case DT_REL:
971 obj->rel = (const Elf_Rel *) (obj->relocbase + dynp->d_un.d_ptr);
972 break;
973
974 case DT_RELSZ:
975 obj->relsize = dynp->d_un.d_val;
976 break;
977
978 case DT_RELENT:
979 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
980 break;
981
982 case DT_JMPREL:
983 obj->pltrel = (const Elf_Rel *)
984 (obj->relocbase + dynp->d_un.d_ptr);
985 break;
986
987 case DT_PLTRELSZ:
988 obj->pltrelsize = dynp->d_un.d_val;
989 break;
990
991 case DT_RELA:
992 obj->rela = (const Elf_Rela *) (obj->relocbase + dynp->d_un.d_ptr);
993 break;
994
995 case DT_RELASZ:
996 obj->relasize = dynp->d_un.d_val;
997 break;
998
999 case DT_RELAENT:
1000 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
1001 break;
1002
1003 case DT_PLTREL:
1004 plttype = dynp->d_un.d_val;
1005 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
1006 break;
1007
1008 case DT_SYMTAB:
1009 obj->symtab = (const Elf_Sym *)
1010 (obj->relocbase + dynp->d_un.d_ptr);
1011 break;
1012
1013 case DT_SYMENT:
1014 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
1015 break;
1016
1017 case DT_STRTAB:
1018 obj->strtab = (const char *) (obj->relocbase + dynp->d_un.d_ptr);
1019 break;
1020
1021 case DT_STRSZ:
1022 obj->strsize = dynp->d_un.d_val;
1023 break;
1024
fcf53d9b
JM
1025 case DT_VERNEED:
1026 obj->verneed = (const Elf_Verneed *) (obj->relocbase +
1027 dynp->d_un.d_val);
1028 break;
1029
1030 case DT_VERNEEDNUM:
1031 obj->verneednum = dynp->d_un.d_val;
1032 break;
1033
1034 case DT_VERDEF:
1035 obj->verdef = (const Elf_Verdef *) (obj->relocbase +
1036 dynp->d_un.d_val);
1037 break;
1038
1039 case DT_VERDEFNUM:
1040 obj->verdefnum = dynp->d_un.d_val;
1041 break;
1042
1043 case DT_VERSYM:
1044 obj->versyms = (const Elf_Versym *)(obj->relocbase +
1045 dynp->d_un.d_val);
1046 break;
1047
984263bc
MD
1048 case DT_HASH:
1049 {
d697cc44 1050 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
984263bc
MD
1051 (obj->relocbase + dynp->d_un.d_ptr);
1052 obj->nbuckets = hashtab[0];
1053 obj->nchains = hashtab[1];
1054 obj->buckets = hashtab + 2;
1055 obj->chains = obj->buckets + obj->nbuckets;
7629c631
JM
1056 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 &&
1057 obj->buckets != NULL;
1058 }
1059 break;
1060
1061 case DT_GNU_HASH:
1062 {
1063 const Elf_Hashelt *hashtab = (const Elf_Hashelt *)
1064 (obj->relocbase + dynp->d_un.d_ptr);
1065 obj->nbuckets_gnu = hashtab[0];
1066 obj->symndx_gnu = hashtab[1];
1067 const Elf32_Word nmaskwords = hashtab[2];
1068 const int bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords;
1069 /* Number of bitmask words is required to be power of 2 */
1070 const bool nmw_power2 = ((nmaskwords & (nmaskwords - 1)) == 0);
1071 obj->maskwords_bm_gnu = nmaskwords - 1;
1072 obj->shift2_gnu = hashtab[3];
1073 obj->bloom_gnu = (Elf_Addr *) (hashtab + 4);
1074 obj->buckets_gnu = hashtab + 4 + bloom_size32;
1075 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu -
1076 obj->symndx_gnu;
1077 obj->valid_hash_gnu = nmw_power2 && obj->nbuckets_gnu > 0 &&
1078 obj->buckets_gnu != NULL;
984263bc
MD
1079 }
1080 break;
1081
1082 case DT_NEEDED:
1083 if (!obj->rtld) {
1084 Needed_Entry *nep = NEW(Needed_Entry);
1085 nep->name = dynp->d_un.d_val;
1086 nep->obj = NULL;
1087 nep->next = NULL;
1088
1089 *needed_tail = nep;
1090 needed_tail = &nep->next;
1091 }
1092 break;
1093
35b2b265
JM
1094 case DT_FILTER:
1095 if (!obj->rtld) {
1096 Needed_Entry *nep = NEW(Needed_Entry);
1097 nep->name = dynp->d_un.d_val;
1098 nep->obj = NULL;
1099 nep->next = NULL;
1100
1101 *needed_filtees_tail = nep;
1102 needed_filtees_tail = &nep->next;
1103 }
1104 break;
1105
1106 case DT_AUXILIARY:
1107 if (!obj->rtld) {
1108 Needed_Entry *nep = NEW(Needed_Entry);
1109 nep->name = dynp->d_un.d_val;
1110 nep->obj = NULL;
1111 nep->next = NULL;
1112
1113 *needed_aux_filtees_tail = nep;
1114 needed_aux_filtees_tail = &nep->next;
1115 }
1116 break;
1117
984263bc
MD
1118 case DT_PLTGOT:
1119 obj->pltgot = (Elf_Addr *) (obj->relocbase + dynp->d_un.d_ptr);
1120 break;
1121
1122 case DT_TEXTREL:
1123 obj->textrel = true;
1124 break;
1125
1126 case DT_SYMBOLIC:
1127 obj->symbolic = true;
1128 break;
1129
1130 case DT_RPATH:
167f7029 1131 case DT_RUNPATH: /* XXX: process separately */
984263bc
MD
1132 /*
1133 * We have to wait until later to process this, because we
1134 * might not have gotten the address of the string table yet.
1135 */
b566341b 1136 *dyn_rpath = dynp;
984263bc
MD
1137 break;
1138
1139 case DT_SONAME:
b566341b 1140 *dyn_soname = dynp;
984263bc
MD
1141 break;
1142
1143 case DT_INIT:
fcf53d9b 1144 obj->init = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
984263bc
MD
1145 break;
1146
1147 case DT_FINI:
fcf53d9b 1148 obj->fini = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
984263bc
MD
1149 break;
1150
b28bf640
JM
1151 case DT_PREINIT_ARRAY:
1152 obj->preinit_array = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1153 break;
1154
1155 case DT_INIT_ARRAY:
1156 obj->init_array = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1157 break;
1158
1159 case DT_FINI_ARRAY:
1160 obj->fini_array = (Elf_Addr) (obj->relocbase + dynp->d_un.d_ptr);
1161 break;
1162
1163 case DT_PREINIT_ARRAYSZ:
1164 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1165 break;
1166
1167 case DT_INIT_ARRAYSZ:
1168 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1169 break;
1170
1171 case DT_FINI_ARRAYSZ:
1172 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1173 break;
1174
984263bc
MD
1175 case DT_DEBUG:
1176 /* XXX - not implemented yet */
c3098c28
SS
1177 if (!early)
1178 dbg("Filling in DT_DEBUG entry");
984263bc
MD
1179 ((Elf_Dyn*)dynp)->d_un.d_ptr = (Elf_Addr) &r_debug;
1180 break;
1181
167f7029 1182 case DT_FLAGS:
fcf53d9b
JM
1183 if ((dynp->d_un.d_val & DF_ORIGIN) && trust)
1184 obj->z_origin = true;
167f7029
JS
1185 if (dynp->d_un.d_val & DF_SYMBOLIC)
1186 obj->symbolic = true;
1187 if (dynp->d_un.d_val & DF_TEXTREL)
1188 obj->textrel = true;
1189 if (dynp->d_un.d_val & DF_BIND_NOW)
1190 obj->bind_now = true;
8301820e
JM
1191 /*if (dynp->d_un.d_val & DF_STATIC_TLS)
1192 ;*/
167f7029
JS
1193 break;
1194
fcf53d9b
JM
1195 case DT_FLAGS_1:
1196 if (dynp->d_un.d_val & DF_1_NOOPEN)
1197 obj->z_noopen = true;
1198 if ((dynp->d_un.d_val & DF_1_ORIGIN) && trust)
1199 obj->z_origin = true;
8301820e
JM
1200 /*if (dynp->d_un.d_val & DF_1_GLOBAL)
1201 XXX ;*/
fcf53d9b
JM
1202 if (dynp->d_un.d_val & DF_1_BIND_NOW)
1203 obj->bind_now = true;
1204 if (dynp->d_un.d_val & DF_1_NODELETE)
1205 obj->z_nodelete = true;
35b2b265
JM
1206 if (dynp->d_un.d_val & DF_1_LOADFLTR)
1207 obj->z_loadfltr = true;
fcf53d9b
JM
1208 break;
1209
984263bc 1210 default:
fcf53d9b
JM
1211 if (!early) {
1212 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
1213 (long)dynp->d_tag);
1214 }
984263bc
MD
1215 break;
1216 }
1217 }
1218
1219 obj->traced = false;
1220
1221 if (plttype == DT_RELA) {
1222 obj->pltrela = (const Elf_Rela *) obj->pltrel;
1223 obj->pltrel = NULL;
1224 obj->pltrelasize = obj->pltrelsize;
1225 obj->pltrelsize = 0;
1226 }
7629c631
JM
1227
1228 /* Determine size of dynsym table (equal to nchains of sysv hash) */
1229 if (obj->valid_hash_sysv)
1230 obj->dynsymcount = obj->nchains;
1231 else if (obj->valid_hash_gnu) {
1232 obj->dynsymcount = 0;
1233 for (Elf32_Word bkt = 0; bkt < obj->nbuckets_gnu; bkt++) {
1234 if (obj->buckets_gnu[bkt] == 0)
1235 continue;
1236 const Elf32_Word *hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]];
1237 do
1238 obj->dynsymcount++;
1239 while ((*hashval++ & 1u) == 0);
1240 }
1241 obj->dynsymcount += obj->symndx_gnu;
1242 }
b566341b
JM
1243}
1244
1245static void
1246digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
1247 const Elf_Dyn *dyn_soname)
1248{
984263bc 1249
fcf53d9b
JM
1250 if (obj->z_origin && obj->origin_path == NULL) {
1251 obj->origin_path = xmalloc(PATH_MAX);
1252 if (rtld_dirname_abs(obj->path, obj->origin_path) == -1)
1253 die();
1254 }
1255
1256 if (dyn_rpath != NULL) {
1257 obj->rpath = (char *)obj->strtab + dyn_rpath->d_un.d_val;
1258 if (obj->z_origin)
1259 obj->rpath = origin_subst(obj->rpath, obj->origin_path);
1260 }
1261
1262 if (dyn_soname != NULL)
1263 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
984263bc
MD
1264}
1265
b566341b
JM
1266static void
1267digest_dynamic(Obj_Entry *obj, int early)
1268{
1269 const Elf_Dyn *dyn_rpath;
1270 const Elf_Dyn *dyn_soname;
1271
1272 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname);
1273 digest_dynamic2(obj, dyn_rpath, dyn_soname);
1274}
1275
984263bc
MD
1276/*
1277 * Process a shared object's program header. This is used only for the
1278 * main program, when the kernel has already loaded the main program
1279 * into memory before calling the dynamic linker. It creates and
1280 * returns an Obj_Entry structure.
1281 */
1282static Obj_Entry *
1283digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
1284{
1285 Obj_Entry *obj;
1286 const Elf_Phdr *phlimit = phdr + phnum;
1287 const Elf_Phdr *ph;
7f5c8f97 1288 Elf_Addr note_start, note_end;
984263bc
MD
1289 int nsegs = 0;
1290
1291 obj = obj_new();
1292 for (ph = phdr; ph < phlimit; ph++) {
fcf53d9b
JM
1293 if (ph->p_type != PT_PHDR)
1294 continue;
984263bc 1295
fcf53d9b
JM
1296 obj->phdr = phdr;
1297 obj->phsize = ph->p_memsz;
1298 obj->relocbase = (caddr_t)phdr - ph->p_vaddr;
1299 break;
1300 }
1301
e9de6dcc
JM
1302 obj->stack_flags = PF_X | PF_R | PF_W;
1303
fcf53d9b
JM
1304 for (ph = phdr; ph < phlimit; ph++) {
1305 switch (ph->p_type) {
984263bc
MD
1306
1307 case PT_INTERP:
fcf53d9b 1308 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
984263bc
MD
1309 break;
1310
1311 case PT_LOAD:
1312 if (nsegs == 0) { /* First load segment */
1313 obj->vaddrbase = trunc_page(ph->p_vaddr);
fcf53d9b 1314 obj->mapbase = obj->vaddrbase + obj->relocbase;
984263bc
MD
1315 obj->textsize = round_page(ph->p_vaddr + ph->p_memsz) -
1316 obj->vaddrbase;
1317 } else { /* Last load segment */
1318 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1319 obj->vaddrbase;
1320 }
1321 nsegs++;
1322 break;
1323
1324 case PT_DYNAMIC:
fcf53d9b 1325 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
984263bc 1326 break;
55b88cae
DX
1327
1328 case PT_TLS:
1329 obj->tlsindex = 1;
1330 obj->tlssize = ph->p_memsz;
1331 obj->tlsalign = ph->p_align;
1332 obj->tlsinitsize = ph->p_filesz;
fcf53d9b 1333 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
55b88cae 1334 break;
007f494e 1335
e9de6dcc
JM
1336 case PT_GNU_STACK:
1337 obj->stack_flags = ph->p_flags;
1338 break;
1339
007f494e
JM
1340 case PT_GNU_RELRO:
1341 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
1342 obj->relro_size = round_page(ph->p_memsz);
1343 break;
7f5c8f97
JM
1344
1345 case PT_NOTE:
e64cf055 1346 obj->note_present = true;
7f5c8f97
JM
1347 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr;
1348 note_end = note_start + ph->p_filesz;
1349 digest_notes(obj, note_start, note_end);
1350 break;
984263bc
MD
1351 }
1352 }
1353 if (nsegs < 1) {
1354 _rtld_error("%s: too few PT_LOAD segments", path);
1355 return NULL;
1356 }
1357
1358 obj->entry = entry;
1359 return obj;
1360}
1361
7f5c8f97
JM
1362void
1363digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end)
1364{
1365 const Elf_Note *note;
1366 const char *note_name;
1367 uintptr_t p;
1368
1369 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end;
1370 note = (const Elf_Note *)((const char *)(note + 1) +
1371 roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
1372 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) {
1373 if (note->n_namesz != sizeof(NOTE_VENDOR) ||
1374 note->n_descsz != sizeof(int32_t))
1375 continue;
1376 if (note->n_type != ABI_NOTETYPE && note->n_type != CRT_NOINIT_NOTETYPE)
1377 continue;
1378 note_name = (const char *)(note + 1);
1379 if (strncmp(NOTE_VENDOR, note_name, sizeof(NOTE_VENDOR)) != 0)
1380 continue;
1381 switch (note->n_type) {
1382 case ABI_NOTETYPE:
e64cf055 1383 /* DragonFly osrel note */
7f5c8f97
JM
1384 p = (uintptr_t)(note + 1);
1385 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1386 obj->osrel = *(const int32_t *)(p);
1387 dbg("note osrel %d", obj->osrel);
1388 break;
1389 case CRT_NOINIT_NOTETYPE:
e64cf055 1390 /* DragonFly 'crt does not call init' note */
7f5c8f97
JM
1391 obj->crt_no_init = true;
1392 dbg("note crt_no_init");
1393 break;
1394 }
1395 }
1396}
1397
984263bc
MD
1398static Obj_Entry *
1399dlcheck(void *handle)
1400{
1401 Obj_Entry *obj;
1402
1403 for (obj = obj_list; obj != NULL; obj = obj->next)
1404 if (obj == (Obj_Entry *) handle)
1405 break;
1406
1407 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1408 _rtld_error("Invalid shared object handle %p", handle);
1409 return NULL;
1410 }
1411 return obj;
1412}
1413
1414/*
1415 * If the given object is already in the donelist, return true. Otherwise
1416 * add the object to the list and return false.
1417 */
1418static bool
1419donelist_check(DoneList *dlp, const Obj_Entry *obj)
1420{
1421 unsigned int i;
1422
1423 for (i = 0; i < dlp->num_used; i++)
1424 if (dlp->objs[i] == obj)
1425 return true;
1426 /*
1427 * Our donelist allocation should always be sufficient. But if
1428 * our threads locking isn't working properly, more shared objects
1429 * could have been loaded since we allocated the list. That should
1430 * never happen, but we'll handle it properly just in case it does.
1431 */
1432 if (dlp->num_used < dlp->num_alloc)
1433 dlp->objs[dlp->num_used++] = obj;
1434 return false;
1435}
1436
1437/*
1438 * Hash function for symbol table lookup. Don't even think about changing
1439 * this. It is specified by the System V ABI.
1440 */
1441unsigned long
1442elf_hash(const char *name)
1443{
1444 const unsigned char *p = (const unsigned char *) name;
1445 unsigned long h = 0;
1446 unsigned long g;
1447
1448 while (*p != '\0') {
1449 h = (h << 4) + *p++;
1450 if ((g = h & 0xf0000000) != 0)
1451 h ^= g >> 24;
1452 h &= ~g;
1453 }
1454 return h;
1455}
1456
7629c631
JM
1457/*
1458 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits
1459 * unsigned in case it's implemented with a wider type.
1460 */
1461static uint_fast32_t
1462gnu_hash (const char *s)
1463{
1464 uint_fast32_t h = 5381;
1465 for (unsigned char c = *s; c != '\0'; c = *++s)
1466 h = h * 33 + c;
1467 return h & 0xffffffff;
1468}
1469
984263bc
MD
1470/*
1471 * Find the library with the given name, and return its full pathname.
1472 * The returned string is dynamically allocated. Generates an error
1473 * message and returns NULL if the library cannot be found.
1474 *
1475 * If the second argument is non-NULL, then it refers to an already-
1476 * loaded shared object, whose library search path will be searched.
1477 *
1478 * The search order is:
984263bc 1479 * LD_LIBRARY_PATH
4e390e27 1480 * rpath in the referencing file
984263bc
MD
1481 * ldconfig hints
1482 * /usr/lib
1483 */
1484static char *
fcf53d9b 1485find_library(const char *xname, const Obj_Entry *refobj)
984263bc
MD
1486{
1487 char *pathname;
fcf53d9b 1488 char *name;
984263bc 1489
fcf53d9b
JM
1490 if (strchr(xname, '/') != NULL) { /* Hard coded pathname */
1491 if (xname[0] != '/' && !trust) {
984263bc 1492 _rtld_error("Absolute pathname required for shared object \"%s\"",
fcf53d9b 1493 xname);
984263bc
MD
1494 return NULL;
1495 }
fcf53d9b
JM
1496 if (refobj != NULL && refobj->z_origin)
1497 return origin_subst(xname, refobj->origin_path);
1498 else
1499 return xstrdup(xname);
984263bc
MD
1500 }
1501
fcf53d9b
JM
1502 if (libmap_disable || (refobj == NULL) ||
1503 (name = lm_find(refobj->path, xname)) == NULL)
1504 name = (char *)xname;
1505
984263bc
MD
1506 dbg(" Searching for \"%s\"", name);
1507
1508 if ((pathname = search_library_path(name, ld_library_path)) != NULL ||
1509 (refobj != NULL &&
1510 (pathname = search_library_path(name, refobj->rpath)) != NULL) ||
1511 (pathname = search_library_path(name, gethints())) != NULL ||
1512 (pathname = search_library_path(name, STANDARD_LIBRARY_PATH)) != NULL)
1513 return pathname;
1514
446c0d3a
JS
1515 if(refobj != NULL && refobj->path != NULL) {
1516 _rtld_error("Shared object \"%s\" not found, required by \"%s\"",
1517 name, basename(refobj->path));
1518 } else {
1519 _rtld_error("Shared object \"%s\" not found", name);
1520 }
984263bc
MD
1521 return NULL;
1522}
1523
1524/*
1525 * Given a symbol number in a referencing object, find the corresponding
1526 * definition of the symbol. Returns a pointer to the symbol, or NULL if
1527 * no definition was found. Returns a pointer to the Obj_Entry of the
1528 * defining object via the reference parameter DEFOBJ_OUT.
1529 */
1530const Elf_Sym *
1531find_symdef(unsigned long symnum, const Obj_Entry *refobj,
35b2b265
JM
1532 const Obj_Entry **defobj_out, int flags, SymCache *cache,
1533 RtldLockState *lockstate)
984263bc
MD
1534{
1535 const Elf_Sym *ref;
1536 const Elf_Sym *def;
1537 const Obj_Entry *defobj;
35b2b265 1538 SymLook req;
984263bc 1539 const char *name;
35b2b265 1540 int res;
984263bc
MD
1541
1542 /*
1543 * If we have already found this symbol, get the information from
1544 * the cache.
1545 */
7629c631 1546 if (symnum >= refobj->dynsymcount)
984263bc
MD
1547 return NULL; /* Bad object */
1548 if (cache != NULL && cache[symnum].sym != NULL) {
1549 *defobj_out = cache[symnum].obj;
1550 return cache[symnum].sym;
1551 }
1552
1553 ref = refobj->symtab + symnum;
1554 name = refobj->strtab + ref->st_name;
35b2b265 1555 def = NULL;
984263bc
MD
1556 defobj = NULL;
1557
0e588128
SS
1558 /*
1559 * We don't have to do a full scale lookup if the symbol is local.
1560 * We know it will bind to the instance in this load module; to
1561 * which we already have a pointer (ie ref). By not doing a lookup,
1562 * we not only improve performance, but it also avoids unresolvable
1563 * symbols when local symbols are not in the hash table.
1564 *
1565 * This might occur for TLS module relocations, which simply use
1566 * symbol 0.
1567 */
1568 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1569 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
c3098c28
SS
1570 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1571 symnum);
1572 }
35b2b265
JM
1573 symlook_init(&req, name);
1574 req.flags = flags;
1575 req.ventry = fetch_ventry(refobj, symnum);
1576 req.lockstate = lockstate;
1577 res = symlook_default(&req, refobj);
1578 if (res == 0) {
1579 def = req.sym_out;
1580 defobj = req.defobj_out;
1581 }
0e588128 1582 } else {
c3098c28
SS
1583 def = ref;
1584 defobj = refobj;
0e588128 1585 }
984263bc
MD
1586
1587 /*
1588 * If we found no definition and the reference is weak, treat the
1589 * symbol as having the value zero.
1590 */
1591 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
1592 def = &sym_zero;
1593 defobj = obj_main;
1594 }
1595
1596 if (def != NULL) {
1597 *defobj_out = defobj;
1598 /* Record the information in the cache to avoid subsequent lookups. */
1599 if (cache != NULL) {
1600 cache[symnum].sym = def;
1601 cache[symnum].obj = defobj;
1602 }
fcf53d9b
JM
1603 } else {
1604 if (refobj != &obj_rtld)
1605 _rtld_error("%s: Undefined symbol \"%s\"", refobj->path, name);
1606 }
984263bc
MD
1607 return def;
1608}
1609
1610/*
1611 * Return the search path from the ldconfig hints file, reading it if
1612 * necessary. Returns NULL if there are problems with the hints file,
1613 * or if the search path there is empty.
1614 */
1615static const char *
1616gethints(void)
1617{
1618 static char *hints;
1619
1620 if (hints == NULL) {
1621 int fd;
1622 struct elfhints_hdr hdr;
1623 char *p;
1624
1625 /* Keep from trying again in case the hints file is bad. */
1626 hints = "";
1627
fcf53d9b 1628 if ((fd = open(ld_elf_hints_path, O_RDONLY)) == -1)
984263bc
MD
1629 return NULL;
1630 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
1631 hdr.magic != ELFHINTS_MAGIC ||
1632 hdr.version != 1) {
1633 close(fd);
1634 return NULL;
1635 }
1636 p = xmalloc(hdr.dirlistlen + 1);
1637 if (lseek(fd, hdr.strtab + hdr.dirlist, SEEK_SET) == -1 ||
fcf53d9b 1638 read(fd, p, hdr.dirlistlen + 1) != (ssize_t)hdr.dirlistlen + 1) {
984263bc
MD
1639 free(p);
1640 close(fd);
1641 return NULL;
1642 }
1643 hints = p;
1644 close(fd);
1645 }
1646 return hints[0] != '\0' ? hints : NULL;
1647}
1648
1649static void
1650init_dag(Obj_Entry *root)
1651{
153ab392
JM
1652 const Needed_Entry *needed;
1653 const Objlist_Entry *elm;
984263bc
MD
1654 DoneList donelist;
1655
fcf53d9b
JM
1656 if (root->dag_inited)
1657 return;
984263bc 1658 donelist_init(&donelist);
984263bc 1659
153ab392
JM
1660 /* Root object belongs to own DAG. */
1661 objlist_push_tail(&root->dldags, root);
1662 objlist_push_tail(&root->dagmembers, root);
1663 donelist_check(&donelist, root);
fcf53d9b 1664
153ab392
JM
1665 /*
1666 * Add dependencies of root object to DAG in breadth order
1667 * by exploiting the fact that each new object get added
1668 * to the tail of the dagmembers list.
1669 */
1670 STAILQ_FOREACH(elm, &root->dagmembers, link) {
1671 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) {
1672 if (needed->obj == NULL || donelist_check(&donelist, needed->obj))
1673 continue;
1674 objlist_push_tail(&needed->obj->dldags, root);
1675 objlist_push_tail(&root->dagmembers, needed->obj);
1676 }
1677 }
1678 root->dag_inited = true;
984263bc
MD
1679}
1680
1681/*
1682 * Initialize the dynamic linker. The argument is the address at which
1683 * the dynamic linker has been mapped into memory. The primary task of
1684 * this function is to relocate the dynamic linker.
1685 */
1686static void
b566341b 1687init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
984263bc 1688{
c3098c28 1689 Obj_Entry objtmp; /* Temporary rtld object */
b566341b
JM
1690 const Elf_Dyn *dyn_rpath;
1691 const Elf_Dyn *dyn_soname;
c3098c28 1692
984263bc
MD
1693 /*
1694 * Conjure up an Obj_Entry structure for the dynamic linker.
1695 *
fcf53d9b
JM
1696 * The "path" member can't be initialized yet because string constants
1697 * cannot yet be accessed. Below we will set it correctly.
984263bc 1698 */
4648abf3 1699 memset(&objtmp, 0, sizeof(objtmp));
c3098c28
SS
1700 objtmp.path = NULL;
1701 objtmp.rtld = true;
1702 objtmp.mapbase = mapbase;
984263bc 1703#ifdef PIC
c3098c28 1704 objtmp.relocbase = mapbase;
984263bc 1705#endif
fcf53d9b 1706 if (RTLD_IS_DYNAMIC()) {
c3098c28 1707 objtmp.dynamic = rtld_dynamic(&objtmp);
b566341b 1708 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname);
c3098c28
SS
1709 assert(objtmp.needed == NULL);
1710 assert(!objtmp.textrel);
984263bc
MD
1711
1712 /*
1713 * Temporarily put the dynamic linker entry into the object list, so
1714 * that symbols can be found.
1715 */
984263bc 1716
35b2b265 1717 relocate_objects(&objtmp, true, &objtmp, NULL);
984263bc
MD
1718 }
1719
c3098c28 1720 /* Initialize the object list. */
984263bc 1721 obj_tail = &obj_list;
c3098c28
SS
1722
1723 /* Now that non-local variables can be accesses, copy out obj_rtld. */
1724 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
984263bc 1725
b566341b
JM
1726#ifdef ENABLE_OSRELDATE
1727 if (aux_info[AT_OSRELDATE] != NULL)
1728 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
1729#endif
1730
1731 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname);
1732
984263bc 1733 /* Replace the path with a dynamically allocated copy. */
c3098c28 1734 obj_rtld.path = xstrdup(PATH_RTLD);
984263bc
MD
1735
1736 r_debug.r_brk = r_debug_state;
1737 r_debug.r_state = RT_CONSISTENT;
1738}
1739
1740/*
1741 * Add the init functions from a needed object list (and its recursive
1742 * needed objects) to "list". This is not used directly; it is a helper
1743 * function for initlist_add_objects(). The write lock must be held
1744 * when this function is called.
1745 */
1746static void
1747initlist_add_neededs(Needed_Entry *needed, Objlist *list)
1748{
1749 /* Recursively process the successor needed objects. */
1750 if (needed->next != NULL)
1751 initlist_add_neededs(needed->next, list);
1752
1753 /* Process the current needed object. */
1754 if (needed->obj != NULL)
1755 initlist_add_objects(needed->obj, &needed->obj->next, list);
1756}
1757
1758/*
1759 * Scan all of the DAGs rooted in the range of objects from "obj" to
1760 * "tail" and add their init functions to "list". This recurses over
1761 * the DAGs and ensure the proper init ordering such that each object's
1762 * needed libraries are initialized before the object itself. At the
1763 * same time, this function adds the objects to the global finalization
1764 * list "list_fini" in the opposite order. The write lock must be
1765 * held when this function is called.
1766 */
1767static void
1768initlist_add_objects(Obj_Entry *obj, Obj_Entry **tail, Objlist *list)
1769{
fcf53d9b 1770 if (obj->init_scanned || obj->init_done)
984263bc 1771 return;
fcf53d9b 1772 obj->init_scanned = true;
984263bc
MD
1773
1774 /* Recursively process the successor objects. */
1775 if (&obj->next != tail)
1776 initlist_add_objects(obj->next, tail, list);
1777
1778 /* Recursively process the needed objects. */
1779 if (obj->needed != NULL)
1780 initlist_add_neededs(obj->needed, list);
1781
1782 /* Add the object to the init list. */
7f5c8f97
JM
1783 if (obj->preinit_array != (Elf_Addr)NULL || obj->init != (Elf_Addr)NULL ||
1784 obj->init_array != (Elf_Addr)NULL)
984263bc
MD
1785 objlist_push_tail(list, obj);
1786
1787 /* Add the object to the global fini list in the reverse order. */
b28bf640
JM
1788 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL)
1789 && !obj->on_fini_list) {
984263bc 1790 objlist_push_head(&list_fini, obj);
fcf53d9b
JM
1791 obj->on_fini_list = true;
1792 }
984263bc
MD
1793}
1794
fcf53d9b
JM
1795#ifndef FPTR_TARGET
1796#define FPTR_TARGET(f) ((Elf_Addr) (f))
1797#endif
1798
984263bc
MD
1799static bool
1800is_exported(const Elf_Sym *def)
1801{
d697cc44 1802 Elf_Addr value;
984263bc
MD
1803 const func_ptr_type *p;
1804
d697cc44 1805 value = (Elf_Addr)(obj_rtld.relocbase + def->st_value);
fcf53d9b
JM
1806 for (p = exports; *p != NULL; p++)
1807 if (FPTR_TARGET(*p) == value)
984263bc
MD
1808 return true;
1809 return false;
1810}
1811
35b2b265
JM
1812static void
1813free_needed_filtees(Needed_Entry *n)
1814{
1815 Needed_Entry *needed, *needed1;
1816
1817 for (needed = n; needed != NULL; needed = needed->next) {
1818 if (needed->obj != NULL) {
1819 dlclose(needed->obj);
1820 needed->obj = NULL;
1821 }
1822 }
1823 for (needed = n; needed != NULL; needed = needed1) {
1824 needed1 = needed->next;
1825 free(needed);
1826 }
1827}
1828
1829static void
1830unload_filtees(Obj_Entry *obj)
1831{
1832
1833 free_needed_filtees(obj->needed_filtees);
1834 obj->needed_filtees = NULL;
1835 free_needed_filtees(obj->needed_aux_filtees);
1836 obj->needed_aux_filtees = NULL;
1837 obj->filtees_loaded = false;
1838}
1839
1840static void
1841load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags)
1842{
1843
1844 for (; needed != NULL; needed = needed->next) {
1845 needed->obj = dlopen_object(obj->strtab + needed->name, obj,
1846 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) |
1847 RTLD_LOCAL);
1848 }
1849}
1850
1851static void
1852load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate)
1853{
1854
1855 lock_restart_for_upgrade(lockstate);
1856 if (!obj->filtees_loaded) {
1857 load_filtee1(obj, obj->needed_filtees, flags);
1858 load_filtee1(obj, obj->needed_aux_filtees, flags);
1859 obj->filtees_loaded = true;
1860 }
1861}
1862
1863static int
1864process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags)
1865{
1866 Obj_Entry *obj1;
1867
1868 for (; needed != NULL; needed = needed->next) {
1869 obj1 = needed->obj = load_object(obj->strtab + needed->name, obj,
1870 flags & ~RTLD_LO_NOLOAD);
1871 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0)
1872 return (-1);
1873 if (obj1 != NULL && obj1->z_nodelete && !obj1->ref_nodel) {
1874 dbg("obj %s nodelete", obj1->path);
1875 init_dag(obj1);
1876 ref_dag(obj1);
1877 obj1->ref_nodel = true;
1878 }
1879 }
1880 return (0);
1881}
1882
984263bc
MD
1883/*
1884 * Given a shared object, traverse its list of needed objects, and load
1885 * each of them. Returns 0 on success. Generates an error message and
1886 * returns -1 on failure.
1887 */
1888static int
fcf53d9b 1889load_needed_objects(Obj_Entry *first, int flags)
984263bc 1890{
35b2b265 1891 Obj_Entry *obj;
984263bc
MD
1892
1893 for (obj = first; obj != NULL; obj = obj->next) {
35b2b265
JM
1894 if (process_needed(obj, obj->needed, flags) == -1)
1895 return (-1);
984263bc 1896 }
fcf53d9b 1897 return (0);
984263bc
MD
1898}
1899
1900static int
1901load_preload_objects(void)
1902{
1903 char *p = ld_preload;
1904 static const char delim[] = " \t:;";
1905
1906 if (p == NULL)
eecd52b2 1907 return 0;
984263bc
MD
1908
1909 p += strspn(p, delim);
1910 while (*p != '\0') {
1911 size_t len = strcspn(p, delim);
984263bc 1912 char savech;
38e4b3b6 1913 Obj_Entry *obj;
35b2b265
JM
1914 SymLook req;
1915 int res;
984263bc
MD
1916
1917 savech = p[len];
1918 p[len] = '\0';
fcf53d9b 1919 obj = load_object(p, NULL, 0);
38e4b3b6 1920 if (obj == NULL)
984263bc
MD
1921 return -1; /* XXX - cleanup */
1922 p[len] = savech;
1923 p += len;
1924 p += strspn(p, delim);
38e4b3b6
SS
1925
1926 /* Check for the magic tracing function */
35b2b265
JM
1927 symlook_init(&req, RTLD_FUNCTRACE);
1928 res = symlook_obj(&req, obj);
1929 if (res == 0) {
1930 rtld_functrace = (void *)(req.defobj_out->relocbase +
1931 req.sym_out->st_value);
1932 rtld_functrace_obj = req.defobj_out;
38e4b3b6 1933 }
984263bc 1934 }
fcf53d9b 1935 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
984263bc
MD
1936 return 0;
1937}
1938
b6a22d96 1939/*
fcf53d9b
JM
1940 * Load a shared object into memory, if it is not already loaded.
1941 *
1942 * Returns a pointer to the Obj_Entry for the object. Returns NULL
1943 * on failure.
b6a22d96
JS
1944 */
1945static Obj_Entry *
fcf53d9b 1946load_object(const char *name, const Obj_Entry *refobj, int flags)
b6a22d96
JS
1947{
1948 Obj_Entry *obj;
fcf53d9b
JM
1949 int fd = -1;
1950 struct stat sb;
1951 char *path;
b6a22d96 1952
fcf53d9b
JM
1953 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1954 if (object_match_name(obj, name))
1955 return obj;
b6a22d96 1956
fcf53d9b
JM
1957 path = find_library(name, refobj);
1958 if (path == NULL)
1959 return NULL;
2d6b58a8 1960
fcf53d9b
JM
1961 /*
1962 * If we didn't find a match by pathname, open the file and check
1963 * again by device and inode. This avoids false mismatches caused
1964 * by multiple links or ".." in pathnames.
1965 *
1966 * To avoid a race, we open the file and use fstat() rather than
1967 * using stat().
1968 */
1969 if ((fd = open(path, O_RDONLY)) == -1) {
2d6b58a8 1970 _rtld_error("Cannot open \"%s\"", path);
fcf53d9b
JM
1971 free(path);
1972 return NULL;
2d6b58a8 1973 }
fcf53d9b 1974 if (fstat(fd, &sb) == -1) {
2d6b58a8 1975 _rtld_error("Cannot fstat \"%s\"", path);
fcf53d9b
JM
1976 close(fd);
1977 free(path);
2d6b58a8
JS
1978 return NULL;
1979 }
fcf53d9b
JM
1980 for (obj = obj_list->next; obj != NULL; obj = obj->next)
1981 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
2d6b58a8 1982 break;
fcf53d9b
JM
1983 if (obj != NULL) {
1984 object_add_name(obj, name);
1985 free(path);
1986 close(fd);
1987 return obj;
1988 }
1989 if (flags & RTLD_LO_NOLOAD) {
1990 free(path);
8bdeb8d3 1991 close(fd);
fcf53d9b 1992 return (NULL);
2d6b58a8
JS
1993 }
1994
fcf53d9b
JM
1995 /* First use of this object, so we must map it in */
1996 obj = do_load_object(fd, name, path, &sb, flags);
1997 if (obj == NULL)
1998 free(path);
1999 close(fd);
2000
2001 return obj;
2d6b58a8
JS
2002}
2003
984263bc 2004static Obj_Entry *
fcf53d9b
JM
2005do_load_object(int fd, const char *name, char *path, struct stat *sbp,
2006 int flags)
984263bc
MD
2007{
2008 Obj_Entry *obj;
fcf53d9b 2009 struct statfs fs;
984263bc 2010
fcf53d9b
JM
2011 /*
2012 * but first, make sure that environment variables haven't been
2013 * used to circumvent the noexec flag on a filesystem.
2014 */
2015 if (dangerous_ld_env) {
2016 if (fstatfs(fd, &fs) != 0) {
2017 _rtld_error("Cannot fstatfs \"%s\"", path);
2018 return NULL;
2019 }
2020 if (fs.f_flags & MNT_NOEXEC) {
2021 _rtld_error("Cannot execute objects on %s\n", fs.f_mntonname);
2022 return NULL;
2023 }
984263bc 2024 }
2d6b58a8 2025 dbg("loading \"%s\"", path);
fcf53d9b
JM
2026 obj = map_object(fd, path, sbp);
2027 if (obj == NULL)
2d6b58a8 2028 return NULL;
984263bc 2029
fcf53d9b 2030 object_add_name(obj, name);
2d6b58a8 2031 obj->path = path;
c3098c28 2032 digest_dynamic(obj, 0);
fcf53d9b
JM
2033 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
2034 RTLD_LO_DLOPEN) {
2035 dbg("refusing to load non-loadable \"%s\"", obj->path);
2036 _rtld_error("Cannot dlopen non-loadable %s", obj->path);
2037 munmap(obj->mapbase, obj->mapsize);
2038 obj_free(obj);
2039 return (NULL);
2040 }
984263bc 2041
2d6b58a8
JS
2042 *obj_tail = obj;
2043 obj_tail = &obj->next;
2044 obj_count++;
fcf53d9b 2045 obj_loads++;
2d6b58a8 2046 linkmap_add(obj); /* for GDB & dlinfo() */
e9de6dcc 2047 max_stack_flags |= obj->stack_flags;
984263bc 2048
139b8f34
SW
2049 dbg(" %p .. %p: %s", obj->mapbase,
2050 obj->mapbase + obj->mapsize - 1, obj->path);
2d6b58a8 2051 if (obj->textrel)
fcf53d9b
JM
2052 dbg(" WARNING: %s has impure text", obj->path);
2053 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
2054 obj->path);
984263bc 2055
984263bc
MD
2056 return obj;
2057}
2058
984263bc
MD
2059static Obj_Entry *
2060obj_from_addr(const void *addr)
2061{
984263bc
MD
2062 Obj_Entry *obj;
2063
984263bc 2064 for (obj = obj_list; obj != NULL; obj = obj->next) {
984263bc
MD
2065 if (addr < (void *) obj->mapbase)
2066 continue;
c6873e56 2067 if (addr < (void *) (obj->mapbase + obj->mapsize))
984263bc
MD
2068 return obj;
2069 }
2070 return NULL;
2071}
2072
2073/*
2074 * Call the finalization functions for each of the objects in "list"
fcf53d9b
JM
2075 * belonging to the DAG of "root" and referenced once. If NULL "root"
2076 * is specified, every finalization function will be called regardless
2077 * of the reference count and the list elements won't be freed. All of
2078 * the objects are expected to have non-NULL fini functions.
984263bc
MD
2079 */
2080static void
fcf53d9b 2081objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
984263bc
MD
2082{
2083 Objlist_Entry *elm;
2084 char *saved_msg;
b28bf640
JM
2085 Elf_Addr *fini_addr;
2086 int index;
984263bc 2087
fcf53d9b
JM
2088 assert(root == NULL || root->refcount == 1);
2089
984263bc
MD
2090 /*
2091 * Preserve the current error message since a fini function might
2092 * call into the dynamic linker and overwrite it.
2093 */
2094 saved_msg = errmsg_save();
fcf53d9b
JM
2095 do {
2096 STAILQ_FOREACH(elm, list, link) {
2097 if (root != NULL && (elm->obj->refcount != 1 ||
2098 objlist_find(&root->dagmembers, elm->obj) == NULL))
2099 continue;
b28bf640 2100
fcf53d9b
JM
2101 /* Remove object from fini list to prevent recursive invocation. */
2102 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2103 /*
2104 * XXX: If a dlopen() call references an object while the
2105 * fini function is in progress, we might end up trying to
2106 * unload the referenced object in dlclose() or the object
2107 * won't be unloaded although its fini function has been
2108 * called.
2109 */
2110 lock_release(rtld_bind_lock, lockstate);
b28bf640
JM
2111
2112 /*
2113 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined. When this
2114 * happens, DT_FINI_ARRAY is processed first, and it is also processed
2115 * backwards. It is possible to encounter DT_FINI_ARRAY elements with
2116 * values of 0 or 1, but they need to be ignored.
2117 */
2118 fini_addr = (Elf_Addr *)elm->obj->fini_array;
7f5c8f97 2119 if (fini_addr != NULL && elm->obj->fini_array_num > 0) {
b28bf640
JM
2120 for (index = elm->obj->fini_array_num - 1; index >= 0; index--) {
2121 if (fini_addr[index] != 0 && fini_addr[index] != 1) {
7f5c8f97 2122 dbg("calling fini array function for %s at %p",
b28bf640
JM
2123 elm->obj->path, (void *)fini_addr[index]);
2124 LD_UTRACE(UTRACE_FINI_CALL, elm->obj,
2125 (void *)fini_addr[index], 0, 0, elm->obj->path);
2126 call_initfini_pointer(elm->obj, fini_addr[index]);
2127 }
2128 }
2129 }
2130 if (elm->obj->fini != (Elf_Addr)NULL) {
e64cf055 2131 dbg("calling fini function for %s at %p", elm->obj->path,
b28bf640
JM
2132 (void *)elm->obj->fini);
2133 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini,
2134 0, 0, elm->obj->path);
2135 call_initfini_pointer(elm->obj, elm->obj->fini);
2136 }
fcf53d9b
JM
2137 wlock_acquire(rtld_bind_lock, lockstate);
2138 /* No need to free anything if process is going down. */
2139 if (root != NULL)
2140 free(elm);
2141 /*
2142 * We must restart the list traversal after every fini call
2143 * because a dlclose() call from the fini function or from
2144 * another thread might have modified the reference counts.
2145 */
2146 break;
984263bc 2147 }
fcf53d9b 2148 } while (elm != NULL);
984263bc
MD
2149 errmsg_restore(saved_msg);
2150}
2151
b28bf640
JM
2152/*
2153 * If the main program is defined with a .preinit_array section, call
2154 * each function in order. This must occur before the initialization
2155 * of any shared object or the main program.
2156 */
2157static void
2158preinitialize_main_object (void)
2159{
7f5c8f97 2160 Elf_Addr *preinit_addr;
b28bf640
JM
2161 int index;
2162
7f5c8f97
JM
2163 preinit_addr = (Elf_Addr *)obj_main->preinit_array;
2164 if (preinit_addr == NULL)
b28bf640
JM
2165 return;
2166
7f5c8f97
JM
2167 for (index = 0; index < obj_main->preinit_array_num; index++) {
2168 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) {
2169 dbg("calling preinit function for %s at %p", obj_main->path,
2170 (void *)preinit_addr[index]);
2171 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index],
b28bf640 2172 0, 0, obj_main->path);
7f5c8f97 2173 call_init_pointer(obj_main, preinit_addr[index]);
b28bf640 2174 }
7f5c8f97 2175 }
b28bf640
JM
2176}
2177
984263bc
MD
2178/*
2179 * Call the initialization functions for each of the objects in
2180 * "list". All of the objects are expected to have non-NULL init
2181 * functions.
2182 */
2183static void
fcf53d9b 2184objlist_call_init(Objlist *list, RtldLockState *lockstate)
984263bc
MD
2185{
2186 Objlist_Entry *elm;
fcf53d9b 2187 Obj_Entry *obj;
984263bc 2188 char *saved_msg;
b28bf640
JM
2189 Elf_Addr *init_addr;
2190 int index;
984263bc 2191
fcf53d9b
JM
2192 /*
2193 * Clean init_scanned flag so that objects can be rechecked and
2194 * possibly initialized earlier if any of vectors called below
2195 * cause the change by using dlopen.
2196 */
2197 for (obj = obj_list; obj != NULL; obj = obj->next)
2198 obj->init_scanned = false;
2199
984263bc
MD
2200 /*
2201 * Preserve the current error message since an init function might
2202 * call into the dynamic linker and overwrite it.
2203 */
2204 saved_msg = errmsg_save();
2205 STAILQ_FOREACH(elm, list, link) {
fcf53d9b
JM
2206 if (elm->obj->init_done) /* Initialized early. */
2207 continue;
b28bf640 2208
fcf53d9b
JM
2209 /*
2210 * Race: other thread might try to use this object before current
2211 * one completes the initilization. Not much can be done here
2212 * without better locking.
2213 */
2214 elm->obj->init_done = true;
2215 lock_release(rtld_bind_lock, lockstate);
b28bf640
JM
2216
2217 /*
2218 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined. When
2219 * this happens, DT_INIT is processed first. It is possible to
2220 * encounter DT_INIT_ARRAY elements with values of 0 or 1, but they
2221 * need to be ignored.
2222 */
2223 if (elm->obj->init != (Elf_Addr)NULL) {
7f5c8f97 2224 dbg("calling init function for %s at %p", elm->obj->path,
b28bf640
JM
2225 (void *)elm->obj->init);
2226 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init,
2227 0, 0, elm->obj->path);
2228 call_initfini_pointer(elm->obj, elm->obj->init);
2229 }
2230 init_addr = (Elf_Addr *)elm->obj->init_array;
7f5c8f97
JM
2231 if (init_addr != NULL) {
2232 for (index = 0; index < elm->obj->init_array_num; index++) {
b28bf640 2233 if (init_addr[index] != 0 && init_addr[index] != 1) {
7f5c8f97
JM
2234 dbg("calling init array function for %s at %p", elm->obj->path,
2235 (void *)init_addr[index]);
b28bf640
JM
2236 LD_UTRACE(UTRACE_INIT_CALL, elm->obj,
2237 (void *)init_addr[index], 0, 0, elm->obj->path);
7f5c8f97 2238 call_init_pointer(elm->obj, init_addr[index]);
b28bf640 2239 }
7f5c8f97 2240 }
b28bf640 2241 }
fcf53d9b 2242 wlock_acquire(rtld_bind_lock, lockstate);
984263bc
MD
2243 }
2244 errmsg_restore(saved_msg);
2245}
2246
2247static void
2248objlist_clear(Objlist *list)
2249{
2250 Objlist_Entry *elm;
2251
2252 while (!STAILQ_EMPTY(list)) {
2253 elm = STAILQ_FIRST(list);
2254 STAILQ_REMOVE_HEAD(list, link);
2255 free(elm);
2256 }
2257}
2258
2259static Objlist_Entry *
2260objlist_find(Objlist *list, const Obj_Entry *obj)
2261{
2262 Objlist_Entry *elm;
2263
2264 STAILQ_FOREACH(elm, list, link)
2265 if (elm->obj == obj)
2266 return elm;
2267 return NULL;
2268}
2269
2270static void
2271objlist_init(Objlist *list)
2272{
2273 STAILQ_INIT(list);
2274}
2275
2276static void
2277objlist_push_head(Objlist *list, Obj_Entry *obj)
2278{
2279 Objlist_Entry *elm;
2280
2281 elm = NEW(Objlist_Entry);
2282 elm->obj = obj;
2283 STAILQ_INSERT_HEAD(list, elm, link);
2284}
2285
2286static void
2287objlist_push_tail(Objlist *list, Obj_Entry *obj)
2288{
2289 Objlist_Entry *elm;
2290
2291 elm = NEW(Objlist_Entry);
2292 elm->obj = obj;
2293 STAILQ_INSERT_TAIL(list, elm, link);
2294}
2295
2296static void
2297objlist_remove(Objlist *list, Obj_Entry *obj)
2298{
2299 Objlist_Entry *elm;
2300
2301 if ((elm = objlist_find(list, obj)) != NULL) {
2302 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2303 free(elm);
2304 }
2305}
2306
984263bc
MD
2307/*
2308 * Relocate newly-loaded shared objects. The argument is a pointer to
2309 * the Obj_Entry for the first such object. All objects from the first
2310 * to the end of the list of objects are relocated. Returns 0 on success,
2311 * or -1 on failure.
2312 */
2313static int
35b2b265
JM
2314relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
2315 RtldLockState *lockstate)
984263bc
MD
2316{
2317 Obj_Entry *obj;
2318
2319 for (obj = first; obj != NULL; obj = obj->next) {
c3098c28 2320 if (obj != rtldobj)
984263bc 2321 dbg("relocating \"%s\"", obj->path);
7629c631
JM
2322 if (obj->symtab == NULL || obj->strtab == NULL ||
2323 !(obj->valid_hash_sysv || obj->valid_hash_gnu)) {
984263bc
MD
2324 _rtld_error("%s: Shared object has no run-time symbol table",
2325 obj->path);
2326 return -1;
2327 }
2328
2329 if (obj->textrel) {
2330 /* There are relocations to the write-protected text segment. */
2331 if (mprotect(obj->mapbase, obj->textsize,
2332 PROT_READ|PROT_WRITE|PROT_EXEC) == -1) {
2333 _rtld_error("%s: Cannot write-enable text segment: %s",
b2cf2649 2334 obj->path, rtld_strerror(errno));
984263bc
MD
2335 return -1;
2336 }
2337 }
2338
2339 /* Process the non-PLT relocations. */
35b2b265 2340 if (reloc_non_plt(obj, rtldobj, lockstate))
984263bc
MD
2341 return -1;
2342
4b89341e
MD
2343 /*
2344 * Reprotect the text segment. Make sure it is included in the
2345 * core dump since we modified it. This unfortunately causes the
2346 * entire text segment to core-out but we don't have much of a
2347 * choice. We could try to only reenable core dumps on pages
2348 * in which relocations occured but that is likely most of the text
2349 * pages anyway, and even that would not work because the rest of
2350 * the text pages would wind up as a read-only OBJT_DEFAULT object
2351 * (created due to our modifications) backed by the original OBJT_VNODE
2352 * object, and the ELF coredump code is currently only able to dump
2353 * vnode records for pure vnode-backed mappings, not vnode backings
2354 * to memory objects.
2355 */
2356 if (obj->textrel) {
2357 madvise(obj->mapbase, obj->textsize, MADV_CORE);
984263bc
MD
2358 if (mprotect(obj->mapbase, obj->textsize,
2359 PROT_READ|PROT_EXEC) == -1) {
2360 _rtld_error("%s: Cannot write-protect text segment: %s",
b2cf2649 2361 obj->path, rtld_strerror(errno));
984263bc
MD
2362 return -1;
2363 }
2364 }
2365
0e63a289
JM
2366
2367 /* Set the special PLT or GOT entries. */
2368 init_pltgot(obj);
2369
984263bc
MD
2370 /* Process the PLT relocations. */
2371 if (reloc_plt(obj) == -1)
2372 return -1;
2373 /* Relocate the jump slots if we are doing immediate binding. */
167f7029 2374 if (obj->bind_now || bind_now)
35b2b265 2375 if (reloc_jmpslots(obj, lockstate) == -1)
984263bc
MD
2376 return -1;
2377
984263bc
MD
2378 /*
2379 * Set up the magic number and version in the Obj_Entry. These
2380 * were checked in the crt1.o from the original ElfKit, so we
2381 * set them for backward compatibility.
2382 */
2383 obj->magic = RTLD_MAGIC;
2384 obj->version = RTLD_VERSION;
2385
007f494e
JM
2386 /*
2387 * Set relocated data to read-only status if protection specified
2388 */
2389
2390 if (obj->relro_size) {
2391 if (mprotect(obj->relro_page, obj->relro_size, PROT_READ) == -1) {
2392 _rtld_error("%s: Cannot enforce relro relocation: %s",
b2cf2649 2393 obj->path, rtld_strerror(errno));
007f494e
JM
2394 return -1;
2395 }
2396 }
984263bc
MD
2397 }
2398
0c151ba0 2399 return (0);
984263bc
MD
2400}
2401
0e63a289
JM
2402/*
2403 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots
2404 * referencing STT_GNU_IFUNC symbols is postponed till the other
2405 * relocations are done. The indirect functions specified as
2406 * ifunc are allowed to call other symbols, so we need to have
2407 * objects relocated before asking for resolution from indirects.
2408 *
2409 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion,
2410 * instead of the usual lazy handling of PLT slots. It is
2411 * consistent with how GNU does it.
2412 */
2413static int
2414resolve_object_ifunc(Obj_Entry *obj, bool bind_now, RtldLockState *lockstate)
2415{
2416 if (obj->irelative && reloc_iresolve(obj, lockstate) == -1)
2417 return (-1);
2418 if ((obj->bind_now || bind_now) && obj->gnu_ifunc &&
2419 reloc_gnu_ifunc(obj, lockstate) == -1)
2420 return (-1);
2421 return (0);
2422}
2423
2424static int
2425resolve_objects_ifunc(Obj_Entry *first, bool bind_now, RtldLockState *lockstate)
2426{
2427 Obj_Entry *obj;
2428
2429 for (obj = first; obj != NULL; obj = obj->next) {
2430 if (resolve_object_ifunc(obj, bind_now, lockstate) == -1)
2431 return (-1);
2432 }
2433 return (0);
2434}
2435
2436static int
2437initlist_objects_ifunc(Objlist *list, bool bind_now, RtldLockState *lockstate)
2438{
2439 Objlist_Entry *elm;
2440
2441 STAILQ_FOREACH(elm, list, link) {
2442 if (resolve_object_ifunc(elm->obj, bind_now, lockstate) == -1)
2443 return (-1);
2444 }
2445 return (0);
2446}
2447
984263bc
MD
2448/*
2449 * Cleanup procedure. It will be called (by the atexit mechanism) just
2450 * before the process exits.
2451 */
2452static void
2453rtld_exit(void)
2454{
fcf53d9b 2455 RtldLockState lockstate;
984263bc 2456
fcf53d9b 2457 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc 2458 dbg("rtld_exit()");
fcf53d9b 2459 objlist_call_fini(&list_fini, NULL, &lockstate);
984263bc 2460 /* No need to remove the items from the list, since we are exiting. */
fcf53d9b
JM
2461 if (!libmap_disable)
2462 lm_fini();
2463 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2464}
2465
2466static void *
2467path_enumerate(const char *path, path_enum_proc callback, void *arg)
2468{
2469 if (path == NULL)
2470 return (NULL);
2471
2472 path += strspn(path, ":;");
2473 while (*path != '\0') {
2474 size_t len;
2475 char *res;
2476
2477 len = strcspn(path, ":;");
2478 res = callback(path, len, arg);
2479
2480 if (res != NULL)
2481 return (res);
2482
2483 path += len;
2484 path += strspn(path, ":;");
2485 }
2486
2487 return (NULL);
2488}
2489
2490struct try_library_args {
2491 const char *name;
2492 size_t namelen;
2493 char *buffer;
2494 size_t buflen;
2495};
2496
2497static void *
2498try_library_path(const char *dir, size_t dirlen, void *param)
2499{
2500 struct try_library_args *arg;
2501
2502 arg = param;
2503 if (*dir == '/' || trust) {
2504 char *pathname;
2505
2506 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
2507 return (NULL);
2508
2509 pathname = arg->buffer;
2510 strncpy(pathname, dir, dirlen);
2511 pathname[dirlen] = '/';
2512 strcpy(pathname + dirlen + 1, arg->name);
2513
2514 dbg(" Trying \"%s\"", pathname);
2515 if (access(pathname, F_OK) == 0) { /* We found it */
2516 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
2517 strcpy(pathname, arg->buffer);
2518 return (pathname);
2519 }
2520 }
2521 return (NULL);
2522}
2523
2524static char *
2525search_library_path(const char *name, const char *path)
2526{
2527 char *p;
2528 struct try_library_args arg;
2529
2530 if (path == NULL)
2531 return NULL;
2532
2533 arg.name = name;
2534 arg.namelen = strlen(name);
2535 arg.buffer = xmalloc(PATH_MAX);
2536 arg.buflen = PATH_MAX;
2537
2538 p = path_enumerate(path, try_library_path, &arg);
2539
2540 free(arg.buffer);
2541
2542 return (p);
2543}
2544
2545int
2546dlclose(void *handle)
2547{
2548 Obj_Entry *root;
fcf53d9b 2549 RtldLockState lockstate;
984263bc 2550
fcf53d9b 2551 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2552 root = dlcheck(handle);
2553 if (root == NULL) {
fcf53d9b 2554 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2555 return -1;
2556 }
fcf53d9b
JM
2557 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
2558 root->path);
984263bc
MD
2559
2560 /* Unreference the object and its dependencies. */
2561 root->dl_refcount--;
139b8f34 2562
fcf53d9b 2563 if (root->refcount == 1) {
984263bc 2564 /*
fcf53d9b
JM
2565 * The object will be no longer referenced, so we must unload it.
2566 * First, call the fini functions.
984263bc 2567 */
fcf53d9b
JM
2568 objlist_call_fini(&list_fini, root, &lockstate);
2569
2570 unref_dag(root);
984263bc
MD
2571
2572 /* Finish cleaning up the newly-unreferenced objects. */
2573 GDB_STATE(RT_DELETE,&root->linkmap);
2574 unload_object(root);
2575 GDB_STATE(RT_CONSISTENT,NULL);
fcf53d9b
JM
2576 } else
2577 unref_dag(root);
2578
2579 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
2580 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2581 return 0;
2582}
2583
fcf53d9b 2584char *
984263bc
MD
2585dlerror(void)
2586{
2587 char *msg = error_message;
2588 error_message = NULL;
2589 return msg;
2590}
2591
984263bc
MD
2592void *
2593dlopen(const char *name, int mode)
2594{
153ab392 2595 RtldLockState lockstate;
35b2b265 2596 int lo_flags;
984263bc 2597
fcf53d9b 2598 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
984263bc 2599 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
153ab392
JM
2600 if (ld_tracing != NULL) {
2601 rlock_acquire(rtld_bind_lock, &lockstate);
2602 if (sigsetjmp(lockstate.env, 0) != 0)
2603 lock_upgrade(rtld_bind_lock, &lockstate);
2604 environ = (char **)*get_program_var_addr("environ", &lockstate);
2605 lock_release(rtld_bind_lock, &lockstate);
2606 }
fcf53d9b
JM
2607 lo_flags = RTLD_LO_DLOPEN;
2608 if (mode & RTLD_NODELETE)
2609 lo_flags |= RTLD_LO_NODELETE;
2610 if (mode & RTLD_NOLOAD)
2611 lo_flags |= RTLD_LO_NOLOAD;
2612 if (ld_tracing != NULL)
2613 lo_flags |= RTLD_LO_TRACE;
984263bc 2614
35b2b265
JM
2615 return (dlopen_object(name, obj_main, lo_flags,
2616 mode & (RTLD_MODEMASK | RTLD_GLOBAL)));
2617}
2618
0e63a289
JM
2619static void
2620dlopen_cleanup(Obj_Entry *obj)
2621{
2622
2623 obj->dl_refcount--;
2624 unref_dag(obj);
2625 if (obj->refcount == 0)
2626 unload_object(obj);
2627}
2628
35b2b265
JM
2629static Obj_Entry *
2630dlopen_object(const char *name, Obj_Entry *refobj, int lo_flags, int mode)
2631{
2632 Obj_Entry **old_obj_tail;
2633 Obj_Entry *obj;
2634 Objlist initlist;
2635 RtldLockState lockstate;
2636 int result;
2637
984263bc
MD
2638 objlist_init(&initlist);
2639
fcf53d9b 2640 wlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2641 GDB_STATE(RT_ADD,NULL);
2642
2643 old_obj_tail = obj_tail;
2644 obj = NULL;
2645 if (name == NULL) {
2646 obj = obj_main;
2647 obj->refcount++;
2648 } else {
35b2b265 2649 obj = load_object(name, refobj, lo_flags);
984263bc
MD
2650 }
2651
2652 if (obj) {
2653 obj->dl_refcount++;
139b8f34 2654 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
984263bc 2655 objlist_push_tail(&list_global, obj);
984263bc
MD
2656 if (*old_obj_tail != NULL) { /* We loaded something new. */
2657 assert(*old_obj_tail == obj);
35b2b265 2658 result = load_needed_objects(obj, lo_flags & RTLD_LO_DLOPEN);
fcf53d9b
JM
2659 init_dag(obj);
2660 ref_dag(obj);
2661 if (result != -1)
2662 result = rtld_verify_versions(&obj->dagmembers);
984263bc
MD
2663 if (result != -1 && ld_tracing)
2664 goto trace;
35b2b265
JM
2665 if (result == -1 || (relocate_objects(obj, (mode & RTLD_MODEMASK)
2666 == RTLD_NOW, &obj_rtld, &lockstate)) == -1) {
0e63a289 2667 dlopen_cleanup(obj);
984263bc
MD
2668 obj = NULL;
2669 } else {
2670 /* Make list of init functions to call. */
2671 initlist_add_objects(obj, &obj->next, &initlist);
2672 }
fcf53d9b
JM
2673 } else {
2674
2675 /*
2676 * Bump the reference counts for objects on this DAG. If
2677 * this is the first dlopen() call for the object that was
2678 * already loaded as a dependency, initialize the dag
2679 * starting at it.
2680 */
2681 init_dag(obj);
2682 ref_dag(obj);
2683
2684 if ((lo_flags & RTLD_LO_TRACE) != 0)
2685 goto trace;
2686 }
2687 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
2688 obj->z_nodelete) && !obj->ref_nodel) {
2689 dbg("obj %s nodelete", obj->path);
2690 ref_dag(obj);
2691 obj->z_nodelete = obj->ref_nodel = true;
2692 }
984263bc
MD
2693 }
2694
fcf53d9b
JM
2695 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
2696 name);
984263bc
MD
2697 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
2698
e9de6dcc
JM
2699 map_stacks_exec(&lockstate);
2700
0e63a289
JM
2701 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW,
2702 &lockstate) == -1) {
2703 objlist_clear(&initlist);
2704 dlopen_cleanup(obj);
2705 lock_release(rtld_bind_lock, &lockstate);
2706 return (NULL);
2707 }
2708
fcf53d9b
JM
2709 /* Call the init functions. */
2710 objlist_call_init(&initlist, &lockstate);
984263bc 2711 objlist_clear(&initlist);
fcf53d9b 2712 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2713 return obj;
2714trace:
2715 trace_loaded_objects(obj);
fcf53d9b 2716 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2717 exit(0);
2718}
2719
fcf53d9b
JM
2720static void *
2721do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
2722 int flags)
984263bc 2723{
fcf53d9b
JM
2724 DoneList donelist;
2725 const Obj_Entry *obj, *defobj;
35b2b265
JM
2726 const Elf_Sym *def;
2727 SymLook req;
fcf53d9b 2728 RtldLockState lockstate;
35b2b265 2729 int res;
984263bc 2730
984263bc
MD
2731 def = NULL;
2732 defobj = NULL;
35b2b265
JM
2733 symlook_init(&req, name);
2734 req.ventry = ve;
2735 req.flags = flags | SYMLOOK_IN_PLT;
2736 req.lockstate = &lockstate;
984263bc 2737
fcf53d9b
JM
2738 rlock_acquire(rtld_bind_lock, &lockstate);
2739 if (sigsetjmp(lockstate.env, 0) != 0)
2740 lock_upgrade(rtld_bind_lock, &lockstate);
984263bc
MD
2741 if (handle == NULL || handle == RTLD_NEXT ||
2742 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
984263bc 2743
984263bc
MD
2744 if ((obj = obj_from_addr(retaddr)) == NULL) {
2745 _rtld_error("Cannot determine caller's shared object");
fcf53d9b 2746 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2747 return NULL;
2748 }
2749 if (handle == NULL) { /* Just the caller's shared object. */
35b2b265
JM
2750 res = symlook_obj(&req, obj);
2751 if (res == 0) {
2752 def = req.sym_out;
2753 defobj = req.defobj_out;
2754 }
984263bc
MD
2755 } else if (handle == RTLD_NEXT || /* Objects after caller's */
2756 handle == RTLD_SELF) { /* ... caller included */
2757 if (handle == RTLD_NEXT)
2758 obj = obj->next;
2759 for (; obj != NULL; obj = obj->next) {
35b2b265
JM
2760 res = symlook_obj(&req, obj);
2761 if (res == 0) {
2762 if (def == NULL ||
2763 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK) {
2764 def = req.sym_out;
2765 defobj = req.defobj_out;
fcf53d9b
JM
2766 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
2767 break;
2768 }
2769 }
2770 }
2771 /*
2772 * Search the dynamic linker itself, and possibly resolve the
2773 * symbol from there. This is how the application links to
2774 * dynamic linker services such as dlopen.
2775 */
2776 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
35b2b265
JM
2777 res = symlook_obj(&req, &obj_rtld);
2778 if (res == 0 && is_exported(req.sym_out)) {
2779 def = req.sym_out;
2780 defobj = req.defobj_out;
984263bc
MD
2781 }
2782 }
2783 } else {
2784 assert(handle == RTLD_DEFAULT);
35b2b265
JM
2785 res = symlook_default(&req, obj);
2786 if (res == 0) {
2787 defobj = req.defobj_out;
2788 def = req.sym_out;
2789 }
984263bc
MD
2790 }
2791 } else {
2792 if ((obj = dlcheck(handle)) == NULL) {
fcf53d9b 2793 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2794 return NULL;
2795 }
2796
fb0c631e 2797 donelist_init(&donelist);
984263bc 2798 if (obj->mainprog) {
153ab392
JM
2799 /* Handle obtained by dlopen(NULL, ...) implies global scope. */
2800 res = symlook_global(&req, &donelist);
35b2b265
JM
2801 if (res == 0) {
2802 def = req.sym_out;
2803 defobj = req.defobj_out;
153ab392 2804 }
fcf53d9b 2805 /*
153ab392
JM
2806 * Search the dynamic linker itself, and possibly resolve the
2807 * symbol from there. This is how the application links to
2808 * dynamic linker services such as dlopen.
fcf53d9b 2809 */
153ab392
JM
2810 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
2811 res = symlook_obj(&req, &obj_rtld);
35b2b265
JM
2812 if (res == 0) {
2813 def = req.sym_out;
2814 defobj = req.defobj_out;
2815 }
2816 }
153ab392
JM
2817 }
2818 else {
fcf53d9b 2819 /* Search the whole DAG rooted at the given object. */
153ab392 2820 res = symlook_list(&req, &obj->dagmembers, &donelist);
35b2b265
JM
2821 if (res == 0) {
2822 def = req.sym_out;
2823 defobj = req.defobj_out;
2824 }
984263bc
MD
2825 }
2826 }
2827
2828 if (def != NULL) {
fcf53d9b
JM
2829 lock_release(rtld_bind_lock, &lockstate);
2830
2831 /*
2832 * The value required by the caller is derived from the value
2833 * of the symbol. For the ia64 architecture, we need to
2834 * construct a function descriptor which the caller can use to
2835 * call the function with the right 'gp' value. For other
2836 * architectures and for non-functions, the value is simply
2837 * the relocated value of the symbol.
2838 */
2839 if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
0c151ba0 2840 return (make_function_pointer(def, defobj));
0e63a289
JM
2841 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
2842 return (rtld_resolve_ifunc(defobj, def));
1388aaaf
SW
2843 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) {
2844 tls_index ti;
2845 ti.ti_module = defobj->tlsindex;
2846 ti.ti_offset = def->st_value;
2847 return (__tls_get_addr(&ti));
2848 } else
0c151ba0 2849 return (defobj->relocbase + def->st_value);
984263bc
MD
2850 }
2851
2852 _rtld_error("Undefined symbol \"%s\"", name);
fcf53d9b 2853 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2854 return NULL;
2855}
2856
fcf53d9b
JM
2857void *
2858dlsym(void *handle, const char *name)
2859{
2860 return do_dlsym(handle, name, __builtin_return_address(0), NULL,
2861 SYMLOOK_DLSYM);
2862}
2863
2864dlfunc_t
2865dlfunc(void *handle, const char *name)
2866{
2867 union {
2868 void *d;
2869 dlfunc_t f;
2870 } rv;
2871
2872 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
2873 SYMLOOK_DLSYM);
2874 return (rv.f);
2875}
2876
2877void *
2878dlvsym(void *handle, const char *name, const char *version)
2879{
2880 Ver_Entry ventry;
2881
2882 ventry.name = version;
2883 ventry.file = NULL;
2884 ventry.hash = elf_hash(version);
2885 ventry.flags= 0;
2886 return do_dlsym(handle, name, __builtin_return_address(0), &ventry,
2887 SYMLOOK_DLSYM);
2888}
2889
2890int
2891_rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
2892{
2893 const Obj_Entry *obj;
2894 RtldLockState lockstate;
2895
2896 rlock_acquire(rtld_bind_lock, &lockstate);
2897 obj = obj_from_addr(addr);
2898 if (obj == NULL) {
2899 _rtld_error("No shared object contains address");
2900 lock_release(rtld_bind_lock, &lockstate);
2901 return (0);
2902 }
2903 rtld_fill_dl_phdr_info(obj, phdr_info);
2904 lock_release(rtld_bind_lock, &lockstate);
2905 return (1);
2906}
2907
984263bc
MD
2908int
2909dladdr(const void *addr, Dl_info *info)
2910{
2911 const Obj_Entry *obj;
2912 const Elf_Sym *def;
2913 void *symbol_addr;
2914 unsigned long symoffset;
fcf53d9b
JM
2915 RtldLockState lockstate;
2916
2917 rlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2918 obj = obj_from_addr(addr);
2919 if (obj == NULL) {
2920 _rtld_error("No shared object contains address");
fcf53d9b 2921 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2922 return 0;
2923 }
2924 info->dli_fname = obj->path;
2925 info->dli_fbase = obj->mapbase;
60233e58 2926 info->dli_saddr = NULL;
984263bc
MD
2927 info->dli_sname = NULL;
2928
2929 /*
2930 * Walk the symbol list looking for the symbol whose address is
2931 * closest to the address sent in.
2932 */
7629c631 2933 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) {
984263bc
MD
2934 def = obj->symtab + symoffset;
2935
2936 /*
2937 * For skip the symbol if st_shndx is either SHN_UNDEF or
2938 * SHN_COMMON.
2939 */
2940 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
2941 continue;
2942
2943 /*
2944 * If the symbol is greater than the specified address, or if it
2945 * is further away from addr than the current nearest symbol,
2946 * then reject it.
2947 */
2948 symbol_addr = obj->relocbase + def->st_value;
2949 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
2950 continue;
2951
2952 /* Update our idea of the nearest symbol. */
2953 info->dli_sname = obj->strtab + def->st_name;
2954 info->dli_saddr = symbol_addr;
2955
2956 /* Exact match? */
2957 if (info->dli_saddr == addr)
2958 break;
2959 }
fcf53d9b 2960 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2961 return 1;
2962}
2963
2964int
2965dlinfo(void *handle, int request, void *p)
2966{
2967 const Obj_Entry *obj;
fcf53d9b 2968 RtldLockState lockstate;
984263bc
MD
2969 int error;
2970
fcf53d9b 2971 rlock_acquire(rtld_bind_lock, &lockstate);
984263bc
MD
2972
2973 if (handle == NULL || handle == RTLD_SELF) {
2974 void *retaddr;
2975
2976 retaddr = __builtin_return_address(0); /* __GNUC__ only */
2977 if ((obj = obj_from_addr(retaddr)) == NULL)
2978 _rtld_error("Cannot determine caller's shared object");
2979 } else
2980 obj = dlcheck(handle);
2981
2982 if (obj == NULL) {
fcf53d9b 2983 lock_release(rtld_bind_lock, &lockstate);
984263bc
MD
2984 return (-1);
2985 }
2986
2987 error = 0;
2988 switch (request) {
2989 case RTLD_DI_LINKMAP:
2990 *((struct link_map const **)p) = &obj->linkmap;
2991 break;
2992 case RTLD_DI_ORIGIN:
2993 error = rtld_dirname(obj->path, p);
2994 break;
2995
2996 case RTLD_DI_SERINFOSIZE:
2997 case RTLD_DI_SERINFO:
2998 error = do_search_info(obj, request, (struct dl_serinfo *)p);
2999 break;
3000
3001 default:
3002 _rtld_error("Invalid request %d passed to dlinfo()", request);
3003 error = -1;
3004 }
3005
fcf53d9b
JM
3006 lock_release(rtld_bind_lock, &lockstate);
3007
3008 return (error);
3009}
3010
3011static void
3012rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
3013{
3014
3015 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
3016 phdr_info->dlpi_name = STAILQ_FIRST(&obj->names) ?
3017 STAILQ_FIRST(&obj->names)->name : obj->path;
3018 phdr_info->dlpi_phdr = obj->phdr;
3019 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
3020 phdr_info->dlpi_tls_modid = obj->tlsindex;
3021 phdr_info->dlpi_tls_data = obj->tlsinit;
3022 phdr_info->dlpi_adds = obj_loads;
3023 phdr_info->dlpi_subs = obj_loads - obj_count;
3024}
3025
3026int
3027dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
3028{
3029 struct dl_phdr_info phdr_info;
3030 const Obj_Entry *obj;
3031 RtldLockState bind_lockstate, phdr_lockstate;
3032 int error;
3033
3034 wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
3035 rlock_acquire(rtld_bind_lock, &bind_lockstate);
3036
3037 error = 0;
3038
3039 for (obj = obj_list; obj != NULL; obj = obj->next) {
3040 rtld_fill_dl_phdr_info(obj, &phdr_info);
3041 if ((error = callback(&phdr_info, sizeof phdr_info, param)) != 0)
3042 break;
3043
3044 }
3045 lock_release(rtld_bind_lock, &bind_lockstate);
3046 lock_release(rtld_phdr_lock, &phdr_lockstate);
984263bc
MD
3047
3048 return (error);
3049}
3050
3051struct fill_search_info_args {
3052 int request;
3053 unsigned int flags;
3054 Dl_serinfo *serinfo;
3055 Dl_serpath *serpath;
3056 char *strspace;
3057};
3058
3059static void *
3060fill_search_info(const char *dir, size_t dirlen, void *param)
3061{
3062 struct fill_search_info_args *arg;
3063
3064 arg = param;
3065
3066 if (arg->request == RTLD_DI_SERINFOSIZE) {
3067 arg->serinfo->dls_cnt ++;
fcf53d9b 3068 arg->serinfo->dls_size += sizeof(Dl_serpath) + dirlen + 1;
984263bc
MD
3069 } else {
3070 struct dl_serpath *s_entry;
3071
3072 s_entry = arg->serpath;
3073 s_entry->dls_name = arg->strspace;
3074 s_entry->dls_flags = arg->flags;
3075
3076 strncpy(arg->strspace, dir, dirlen);
3077 arg->strspace[dirlen] = '\0';
3078
3079 arg->strspace += dirlen + 1;
3080 arg->serpath++;
3081 }
3082
3083 return (NULL);
3084}
3085
3086static int
3087do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
3088{
3089 struct dl_serinfo _info;
3090 struct fill_search_info_args args;
3091
3092 args.request = RTLD_DI_SERINFOSIZE;
3093 args.serinfo = &_info;
3094
3095 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
3096 _info.dls_cnt = 0;
3097
3098 path_enumerate(ld_library_path, fill_search_info, &args);
3099 path_enumerate(obj->rpath, fill_search_info, &args);
3100 path_enumerate(gethints(), fill_search_info, &args);
3101 path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args);
3102
3103
3104 if (request == RTLD_DI_SERINFOSIZE) {
3105 info->dls_size = _info.dls_size;
3106 info->dls_cnt = _info.dls_cnt;
3107 return (0);
3108 }
3109
3110 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
3111 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
3112 return (-1);
3113 }
3114
3115 args.request = RTLD_DI_SERINFO;
3116 args.serinfo = info;
3117 args.serpath = &info->dls_serpath[0];
3118 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
3119
3120 args.flags = LA_SER_LIBPATH;
3121 if (path_enumerate(ld_library_path, fill_search_info, &args) != NULL)
3122 return (-1);
3123
3124 args.flags = LA_SER_RUNPATH;
3125 if (path_enumerate(obj->rpath, fill_search_info, &args) != NULL)
3126 return (-1);
3127
3128 args.flags = LA_SER_CONFIG;
3129 if (path_enumerate(gethints(), fill_search_info, &args) != NULL)
3130 return (-1);
3131
3132 args.flags = LA_SER_DEFAULT;
3133 if (path_enumerate(STANDARD_LIBRARY_PATH, fill_search_info, &args) != NULL)
3134 return (-1);
3135 return (0);
3136}
3137
3138static int
3139rtld_dirname(const char *path, char *bname)
3140{
3141 const char *endp;
3142
3143 /* Empty or NULL string gets treated as "." */
3144 if (path == NULL || *path == '\0') {
3145 bname[0] = '.';
3146 bname[1] = '\0';
3147 return (0);
3148 }
3149
3150 /* Strip trailing slashes */
3151 endp = path + strlen(path) - 1;
3152 while (endp > path && *endp == '/')
3153 endp--;
3154
3155 /* Find the start of the dir */
3156 while (endp > path && *endp != '/')
3157 endp--;
3158
3159 /* Either the dir is "/" or there are no slashes */
3160 if (endp == path) {
3161 bname[0] = *endp == '/' ? '/' : '.';
3162 bname[1] = '\0';
3163 return (0);
3164 } else {
3165 do {
3166 endp--;
3167 } while (endp > path && *endp == '/');
3168 }
3169
3170 if (endp - path + 2 > PATH_MAX)
3171 {
3172 _rtld_error("Filename is too long: %s", path);
3173 return(-1);
3174 }
3175
3176 strncpy(bname, path, endp - path + 1);
3177 bname[endp - path + 1] = '\0';
3178 return (0);
3179}
3180
fcf53d9b
JM
3181static int
3182rtld_dirname_abs(const char *path, char *base)
3183{
3184 char base_rel[PATH_MAX];
3185
3186 if (rtld_dirname(path, base) == -1)
3187 return (-1);
3188 if (base[0] == '/')
3189 return (0);
3190 if (getcwd(base_rel, sizeof(base_rel)) == NULL ||
3191 strlcat(base_rel, "/", sizeof(base_rel)) >= sizeof(base_rel) ||
3192 strlcat(base_rel, base, sizeof(base_rel)) >= sizeof(base_rel))
3193 return (-1);
3194 strcpy(base, base_rel);
3195 return (0);
3196}
3197
984263bc
MD
3198static void
3199linkmap_add(Obj_Entry *obj)
3200{
3201 struct link_map *l = &obj->linkmap;
3202 struct link_map *prev;
3203
3204 obj->linkmap.l_name = obj->path;
3205 obj->linkmap.l_addr = obj->mapbase;
3206 obj->linkmap.l_ld = obj->dynamic;
3207#ifdef __mips__
3208 /* GDB needs load offset on MIPS to use the symbols */
3209 obj->linkmap.l_offs = obj->relocbase;
3210#endif
3211
3212 if (r_debug.r_map == NULL) {
3213 r_debug.r_map = l;
3214 return;
3215 }
3216
3217 /*
3218 * Scan to the end of the list, but not past the entry for the
3219 * dynamic linker, which we want to keep at the very end.
3220 */
3221 for (prev = r_debug.r_map;
3222 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
3223 prev = prev->l_next)
3224 ;
3225
3226 /* Link in the new entry. */
3227 l->l_prev = prev;
3228 l->l_next = prev->l_next;
3229 if (l->l_next != NULL)
3230 l->l_next->l_prev = l;
3231 prev->l_next = l;
3232}
3233
3234static void
3235linkmap_delete(Obj_Entry *obj)
3236{
3237 struct link_map *l = &obj->linkmap;
3238
3239 if (l->l_prev == NULL) {
3240 if ((r_debug.r_map = l->l_next) != NULL)
3241 l->l_next->l_prev = NULL;
3242 return;
3243 }
3244
3245 if ((l->l_prev->l_next = l->l_next) != NULL)
3246 l->l_next->l_prev = l->l_prev;
3247}
3248
3249/*
3250 * Function for the debugger to set a breakpoint on to gain control.
3251 *
3252 * The two parameters allow the debugger to easily find and determine
3253 * what the runtime loader is doing and to whom it is doing it.
3254 *
3255 * When the loadhook trap is hit (r_debug_state, set at program
3256 * initialization), the arguments can be found on the stack:
3257 *
3258 * +8 struct link_map *m
3259 * +4 struct r_debug *rd
3260 * +0 RetAddr
3261 */
3262void
3263r_debug_state(struct r_debug* rd, struct link_map *m)
3264{
8301820e
JM
3265 /*
3266 * The following is a hack to force the compiler to emit calls to
3267 * this function, even when optimizing. If the function is empty,
3268 * the compiler is not obliged to emit any code for calls to it,
3269 * even when marked __noinline. However, gdb depends on those
3270 * calls being made.
3271 */
3272 __asm __volatile("" : : : "memory");
984263bc
MD
3273}
3274
3275/*
3276 * Get address of the pointer variable in the main program.
153ab392 3277 * Prefer non-weak symbol over the weak one.
984263bc
MD
3278 */
3279static const void **
153ab392 3280get_program_var_addr(const char *name, RtldLockState *lockstate)
984263bc 3281{
35b2b265 3282 SymLook req;
153ab392 3283 DoneList donelist;
984263bc 3284
35b2b265 3285 symlook_init(&req, name);
153ab392
JM
3286 req.lockstate = lockstate;
3287 donelist_init(&donelist);
3288 if (symlook_global(&req, &donelist) != 0)
3289 return (NULL);
3290 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC)
3291 return ((const void **)make_function_pointer(req.sym_out,
3292 req.defobj_out));
0e63a289
JM
3293 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC)
3294 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out));
153ab392 3295 else
7629c631 3296 return ((const void **)(req.defobj_out->relocbase + req.sym_out->st_value));
984263bc
MD
3297}
3298
3299/*
3300 * Set a pointer variable in the main program to the given value. This
3301 * is used to set key variables such as "environ" before any of the
3302 * init functions are called.
3303 */
3304static void
3305set_program_var(const char *name, const void *value)
3306{
3307 const void **addr;
3308
153ab392 3309 if ((addr = get_program_var_addr(name, NULL)) != NULL) {
984263bc
MD
3310 dbg("\"%s\": *%p <-- %p", name, addr, value);
3311 *addr = value;
3312 }
3313}
3314
153ab392
JM
3315/*
3316 * Search the global objects, including dependencies and main object,
3317 * for the given symbol.
3318 */
3319static int
3320symlook_global(SymLook *req, DoneList *donelist)
3321{
3322 SymLook req1;
3323 const Objlist_Entry *elm;
3324 int res;
3325
3326 symlook_init_from_req(&req1, req);
3327
3328 /* Search all objects loaded at program start up. */
3329 if (req->defobj_out == NULL ||
3330 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
3331 res = symlook_list(&req1, &list_main, donelist);
3332 if (res == 0 && (req->defobj_out == NULL ||
3333 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3334 req->sym_out = req1.sym_out;
3335 req->defobj_out = req1.defobj_out;
3336 assert(req->defobj_out != NULL);
3337 }
3338 }
3339
3340 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
3341 STAILQ_FOREACH(elm, &list_global, link) {
3342 if (req->defobj_out != NULL &&
3343 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
3344 break;
3345 res = symlook_list(&req1, &elm->obj->dagmembers, donelist);
3346 if (res == 0 && (req->defobj_out == NULL ||
3347 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3348 req->sym_out = req1.sym_out;
3349 req->defobj_out = req1.defobj_out;
3350 assert(req->defobj_out != NULL);
3351 }
3352 }
3353
3354 return (req->sym_out != NULL ? 0 : ESRCH);
3355}
3356
8ca15ec8
MD
3357/*
3358 * This is a special version of getenv which is far more efficient
3359 * at finding LD_ environment vars.
3360 */
3361static
3362const char *
3363_getenv_ld(const char *id)
3364{
3365 const char *envp;
3366 int i, j;
3367 int idlen = strlen(id);
3368
3369 if (ld_index == LD_ARY_CACHE)
3370 return(getenv(id));
3371 if (ld_index == 0) {
3372 for (i = j = 0; (envp = environ[i]) != NULL && j < LD_ARY_CACHE; ++i) {
3373 if (envp[0] == 'L' && envp[1] == 'D' && envp[2] == '_')
3374 ld_ary[j++] = envp;
3375 }
3376 if (j == 0)
3377 ld_ary[j++] = "";
3378 ld_index = j;
3379 }
3380 for (i = ld_index - 1; i >= 0; --i) {
3381 if (strncmp(ld_ary[i], id, idlen) == 0 && ld_ary[i][idlen] == '=')
3382 return(ld_ary[i] + idlen + 1);
3383 }
3384 return(NULL);
3385}
3386
984263bc
MD
3387/*
3388 * Given a symbol name in a referencing object, find the corresponding
3389 * definition of the symbol. Returns a pointer to the symbol, or NULL if
3390 * no definition was found. Returns a pointer to the Obj_Entry of the
3391 * defining object via the reference parameter DEFOBJ_OUT.
3392 */
35b2b265
JM
3393static int
3394symlook_default(SymLook *req, const Obj_Entry *refobj)
984263bc
MD
3395{
3396 DoneList donelist;
984263bc 3397 const Objlist_Entry *elm;
35b2b265
JM
3398 SymLook req1;
3399 int res;
153ab392 3400
984263bc 3401 donelist_init(&donelist);
35b2b265 3402 symlook_init_from_req(&req1, req);
984263bc
MD
3403
3404 /* Look first in the referencing object if linked symbolically. */
3405 if (refobj->symbolic && !donelist_check(&donelist, refobj)) {
35b2b265
JM
3406 res = symlook_obj(&req1, refobj);
3407 if (res == 0) {
153ab392
JM
3408 req->sym_out = req1.sym_out;
3409 req->defobj_out = req1.defobj_out;
3410 assert(req->defobj_out != NULL);
984263bc
MD
3411 }
3412 }
3413
153ab392 3414 symlook_global(req, &donelist);
984263bc
MD
3415
3416 /* Search all dlopened DAGs containing the referencing object. */
3417 STAILQ_FOREACH(elm, &refobj->dldags, link) {
153ab392
JM
3418 if (req->sym_out != NULL &&
3419 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK)
984263bc 3420 break;
35b2b265 3421 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist);
153ab392
JM
3422 if (res == 0 && (req->sym_out == NULL ||
3423 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
3424 req->sym_out = req1.sym_out;
3425 req->defobj_out = req1.defobj_out;
3426 assert(req->defobj_out != NULL);
984263bc
MD
3427 }
3428 }
3429
3430 /*
3431 * Search the dynamic linker itself, and possibly resolve the
3432 * symbol from there. This is how the application links to
3433 * dynamic linker services such as dlopen. Only the values listed
3434 * in the "exports" array can be resolved from the dynamic linker.
3435 */
153ab392
JM
3436 if (req->sym_out == NULL ||
3437 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
35b2b265
JM
3438 res = symlook_obj(&req1, &obj_rtld);
3439 if (res == 0 && is_exported(req1.sym_out)) {
153ab392
JM
3440 req->sym_out = req1.sym_out;
3441 req->defobj_out = req1.defobj_out;
3442 assert(req->defobj_out != NULL);
984263bc
MD
3443 }
3444 }
3445
153ab392 3446 return (req->sym_out != NULL ? 0 : ESRCH);
984263bc
MD
3447}
3448
35b2b265
JM
3449static int
3450symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp)
984263bc 3451{
984263bc
MD
3452 const Elf_Sym *def;
3453 const Obj_Entry *defobj;
3454 const Objlist_Entry *elm;
35b2b265
JM
3455 SymLook req1;
3456 int res;
984263bc
MD
3457
3458 def = NULL;
3459 defobj = NULL;
3460 STAILQ_FOREACH(elm, objlist, link) {
3461 if (donelist_check(dlp, elm->obj))
3462 continue;
35b2b265
JM
3463 symlook_init_from_req(&req1, req);
3464 if ((res = symlook_obj(&req1, elm->obj)) == 0) {
3465 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
3466 def = req1.sym_out;
3467 defobj = req1.defobj_out;
984263bc
MD
3468 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3469 break;
3470 }
3471 }
3472 }
35b2b265
JM
3473 if (def != NULL) {
3474 req->sym_out = def;
3475 req->defobj_out = defobj;
3476 return (0);
3477 }
3478 return (ESRCH);
984263bc
MD
3479}
3480
cebaf0af 3481/*
153ab392
JM
3482 * Search the chain of DAGS cointed to by the given Needed_Entry
3483 * for a symbol of the given name. Each DAG is scanned completely
3484 * before advancing to the next one. Returns a pointer to the symbol,
3485 * or NULL if no definition was found.
cebaf0af 3486 */
35b2b265
JM
3487static int
3488symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp)
cebaf0af 3489{
153ab392 3490 const Elf_Sym *def;
cebaf0af 3491 const Needed_Entry *n;
153ab392 3492 const Obj_Entry *defobj;
35b2b265
JM
3493 SymLook req1;
3494 int res;
fcf53d9b 3495
153ab392 3496 def = NULL;
cebaf0af 3497 defobj = NULL;
35b2b265 3498 symlook_init_from_req(&req1, req);
cebaf0af 3499 for (n = needed; n != NULL; n = n->next) {
153ab392
JM
3500 if (n->obj == NULL ||
3501 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0)
fcf53d9b 3502 continue;
153ab392 3503 if (def == NULL || ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK) {
35b2b265
JM
3504 def = req1.sym_out;
3505 defobj = req1.defobj_out;
153ab392
JM
3506 if (ELF_ST_BIND(def->st_info) != STB_WEAK)
3507 break;
fcf53d9b 3508 }
cebaf0af 3509 }
35b2b265
JM
3510 if (def != NULL) {
3511 req->sym_out = def;
3512 req->defobj_out = defobj;
3513 return (0);
3514 }
3515 return (ESRCH);
cebaf0af
SS
3516}
3517
984263bc
MD
3518/*
3519 * Search the symbol table of a single shared object for a symbol of
fcf53d9b 3520 * the given name and version, if requested. Returns a pointer to the
35b2b265
JM
3521 * symbol, or NULL if no definition was found. If the object is
3522 * filter, return filtered symbol from filtee.
984263bc
MD
3523 *
3524 * The symbol's hash value is passed in for efficiency reasons; that
3525 * eliminates many recomputations of the hash value.
3526 */
35b2b265
JM
3527int
3528symlook_obj(SymLook *req, const Obj_Entry *obj)
3529{
3530 DoneList donelist;
3531 SymLook req1;
3532 int res, mres;
3533
7629c631
JM
3534 /*
3535 * There is at least one valid hash at this point, and we prefer to use
3536 * the faster GNU version if available.
3537 */
3538 if (obj->valid_hash_gnu)
3539 mres = symlook_obj2(req, obj);
3540 else
3541 mres = symlook_obj1(req, obj);
3542
35b2b265
JM
3543 if (mres == 0) {
3544 if (obj->needed_filtees != NULL) {
3545 load_filtees(__DECONST(Obj_Entry *, obj), 0, req->lockstate);
3546 donelist_init(&donelist);
3547 symlook_init_from_req(&req1, req);
3548 res = symlook_needed(&req1, obj->needed_filtees, &donelist);
3549 if (res == 0) {
3550 req->sym_out = req1.sym_out;
3551 req->defobj_out = req1.defobj_out;
3552 }
3553 return (res);
3554 }
3555 if (obj->needed_aux_filtees != NULL) {
3556 load_filtees(__DECONST(Obj_Entry *, obj), 0, req->lockstate);
3557 donelist_init(&donelist);
3558 symlook_init_from_req(&req1, req);
3559 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist);
3560 if (res == 0) {
3561 req->sym_out = req1.sym_out;
3562 req->defobj_out = req1.defobj_out;
3563 return (res);
3564 }
3565 }
3566 }
3567 return (mres);
3568}
3569
7629c631
JM
3570/* Symbol match routine common to both hash functions */
3571static bool
3572matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result,
3573 const unsigned long symnum)
3574{
3575 Elf_Versym verndx;
3576 const Elf_Sym *symp = obj->symtab + symnum;
3577 const char *strp = obj->strtab + symp->st_name;
3578
3579 switch (ELF_ST_TYPE(symp->st_info)) {
3580 case STT_FUNC:
3581 case STT_NOTYPE:
3582 case STT_OBJECT:
3583 case STT_COMMON:
3584 case STT_GNU_IFUNC:
3585 if (symp->st_value == 0)
3586 return (false);
3587 /* fallthrough */
3588 case STT_TLS:
3589 if (symp->st_shndx != SHN_UNDEF)
3590 break;
3591 else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
3592 (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
3593 break;
3594 /* fallthrough */
3595 default:
3596 return (false);
3597 }
3598 if (strcmp(req->name, strp) != 0)
3599 return (false);
3600
3601 if (req->ventry == NULL) {
3602 if (obj->versyms != NULL) {
3603 verndx = VER_NDX(obj->versyms[symnum]);
3604 if (verndx > obj->vernum) {
3605 _rtld_error("%s: symbol %s references wrong version %d",
3606 obj->path, obj->strtab + symnum, verndx);
3607 return (false);
3608 }
3609 /*
3610 * If we are not called from dlsym (i.e. this is a normal relocation
3611 * from unversioned binary), accept the symbol immediately if it happens
3612 * to have first version after this shared object became versioned.
3613 * Otherwise, if symbol is versioned and not hidden, remember it. If it
3614 * is the only symbol with this name exported by the shared object, it
3615 * will be returned as a match by the calling function. If symbol is
3616 * global (verndx < 2) accept it unconditionally.
3617 */
3618 if ((req->flags & SYMLOOK_DLSYM) == 0 && verndx == VER_NDX_GIVEN) {
3619 result->sym_out = symp;
3620 return (true);
3621 }
3622 else if (verndx >= VER_NDX_GIVEN) {
3623 if ((obj->versyms[symnum] & VER_NDX_HIDDEN) == 0) {