2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright 1996, 1997, 1998, 1999, 2000 John D. Polstra.
5 * Copyright 2003 Alexander Kabaev <kan@FreeBSD.ORG>.
6 * Copyright 2009-2013 Konstantin Belousov <kib@FreeBSD.ORG>.
7 * Copyright 2012 John Marino <draco@marino.st>.
8 * Copyright 2014-2017 The FreeBSD Foundation
11 * Portions of this software were developed by Konstantin Belousov
12 * under sponsorship from the FreeBSD Foundation.
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 * Dynamic linker for ELF.
38 * John Polstra <jdp@polstra.com>.
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
44 #include <sys/param.h>
45 #include <sys/mount.h>
48 #include <sys/sysctl.h>
50 #include <sys/utsname.h>
51 #include <sys/ktrace.h>
66 #include "rtld_paths.h"
68 #include "rtld_printf.h"
69 #include "rtld_malloc.h"
70 #include "rtld_utrace.h"
72 #include "rtld_libc.h"
75 typedef void (*func_ptr_type)(void);
76 typedef void * (*path_enum_proc) (const char *path, size_t len, void *arg);
79 /* Variables that cannot be static: */
80 extern struct r_debug r_debug; /* For GDB */
81 extern int _thread_autoinit_dummy_decl;
82 extern void (*__cleanup)(void);
90 * Function declarations.
92 static const char *basename(const char *);
93 static void digest_dynamic1(Obj_Entry *, int, const Elf_Dyn **,
94 const Elf_Dyn **, const Elf_Dyn **);
95 static bool digest_dynamic2(Obj_Entry *, const Elf_Dyn *, const Elf_Dyn *,
97 static bool digest_dynamic(Obj_Entry *, int);
98 static Obj_Entry *digest_phdr(const Elf_Phdr *, int, caddr_t, const char *);
99 static void distribute_static_tls(Objlist *, RtldLockState *);
100 static Obj_Entry *dlcheck(void *);
101 static int dlclose_locked(void *, RtldLockState *);
102 static Obj_Entry *dlopen_object(const char *name, int fd, Obj_Entry *refobj,
103 int lo_flags, int mode, RtldLockState *lockstate);
104 static Obj_Entry *do_load_object(int, const char *, char *, struct stat *, int);
105 static int do_search_info(const Obj_Entry *obj, int, struct dl_serinfo *);
106 static bool donelist_check(DoneList *, const Obj_Entry *);
107 static void dump_auxv(Elf_Auxinfo **aux_info);
108 static void errmsg_restore(struct dlerror_save *);
109 static struct dlerror_save *errmsg_save(void);
110 static void *fill_search_info(const char *, size_t, void *);
111 static char *find_library(const char *, const Obj_Entry *, int *);
112 static const char *gethints(bool);
113 static void hold_object(Obj_Entry *);
114 static void unhold_object(Obj_Entry *);
115 static void init_dag(Obj_Entry *);
116 static void init_marker(Obj_Entry *);
117 static void init_pagesizes(Elf_Auxinfo **aux_info);
118 static void init_rtld(caddr_t, Elf_Auxinfo **);
119 static void initlist_add_neededs(Needed_Entry *, Objlist *);
120 static void initlist_add_objects(Obj_Entry *, Obj_Entry *, Objlist *);
121 static int initlist_objects_ifunc(Objlist *, bool, int, RtldLockState *);
122 static void linkmap_add(Obj_Entry *);
123 static void linkmap_delete(Obj_Entry *);
124 static void load_filtees(Obj_Entry *, int flags, RtldLockState *);
125 static void unload_filtees(Obj_Entry *, RtldLockState *);
126 static int load_needed_objects(Obj_Entry *, int);
127 static int load_preload_objects(const char *, bool);
128 static int load_kpreload(const void *addr);
129 static Obj_Entry *load_object(const char *, int fd, const Obj_Entry *, int);
130 static void map_stacks_exec(RtldLockState *);
131 static int obj_disable_relro(Obj_Entry *);
132 static int obj_enforce_relro(Obj_Entry *);
133 static void objlist_call_fini(Objlist *, Obj_Entry *, RtldLockState *);
134 static void objlist_call_init(Objlist *, RtldLockState *);
135 static void objlist_clear(Objlist *);
136 static Objlist_Entry *objlist_find(Objlist *, const Obj_Entry *);
137 static void objlist_init(Objlist *);
138 static void objlist_push_head(Objlist *, Obj_Entry *);
139 static void objlist_push_tail(Objlist *, Obj_Entry *);
140 static void objlist_put_after(Objlist *, Obj_Entry *, Obj_Entry *);
141 static void objlist_remove(Objlist *, Obj_Entry *);
142 static int open_binary_fd(const char *argv0, bool search_in_path,
143 const char **binpath_res);
144 static int parse_args(char* argv[], int argc, bool *use_pathp, int *fdp,
145 const char **argv0, bool *dir_ignore);
146 static int parse_integer(const char *);
147 static void *path_enumerate(const char *, path_enum_proc, const char *, void *);
148 static void print_usage(const char *argv0);
149 static void release_object(Obj_Entry *);
150 static int relocate_object_dag(Obj_Entry *root, bool bind_now,
151 Obj_Entry *rtldobj, int flags, RtldLockState *lockstate);
152 static int relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
153 int flags, RtldLockState *lockstate);
154 static int relocate_objects(Obj_Entry *, bool, Obj_Entry *, int,
156 static int resolve_object_ifunc(Obj_Entry *, bool, int, RtldLockState *);
157 static int rtld_dirname(const char *, char *);
158 static int rtld_dirname_abs(const char *, char *);
159 static void *rtld_dlopen(const char *name, int fd, int mode);
160 static void rtld_exit(void);
161 static void rtld_nop_exit(void);
162 static char *search_library_path(const char *, const char *, const char *,
164 static char *search_library_pathfds(const char *, const char *, int *);
165 static const void **get_program_var_addr(const char *, RtldLockState *);
166 static void set_program_var(const char *, const void *);
167 static int symlook_default(SymLook *, const Obj_Entry *refobj);
168 static int symlook_global(SymLook *, DoneList *);
169 static void symlook_init_from_req(SymLook *, const SymLook *);
170 static int symlook_list(SymLook *, const Objlist *, DoneList *);
171 static int symlook_needed(SymLook *, const Needed_Entry *, DoneList *);
172 static int symlook_obj1_sysv(SymLook *, const Obj_Entry *);
173 static int symlook_obj1_gnu(SymLook *, const Obj_Entry *);
174 static void *tls_get_addr_slow(Elf_Addr **, int, size_t, bool) __noinline;
175 static void trace_loaded_objects(Obj_Entry *, bool);
176 static void unlink_object(Obj_Entry *);
177 static void unload_object(Obj_Entry *, RtldLockState *lockstate);
178 static void unref_dag(Obj_Entry *);
179 static void ref_dag(Obj_Entry *);
180 static char *origin_subst_one(Obj_Entry *, char *, const char *,
182 static char *origin_subst(Obj_Entry *, const char *);
183 static bool obj_resolve_origin(Obj_Entry *obj);
184 static void preinit_main(void);
185 static int rtld_verify_versions(const Objlist *);
186 static int rtld_verify_object_versions(Obj_Entry *);
187 static void object_add_name(Obj_Entry *, const char *);
188 static int object_match_name(const Obj_Entry *, const char *);
189 static void ld_utrace_log(int, void *, void *, size_t, int, const char *);
190 static void rtld_fill_dl_phdr_info(const Obj_Entry *obj,
191 struct dl_phdr_info *phdr_info);
192 static uint32_t gnu_hash(const char *);
193 static bool matched_symbol(SymLook *, const Obj_Entry *, Sym_Match_Result *,
194 const unsigned long);
196 void r_debug_state(struct r_debug *, struct link_map *) __noinline __exported;
197 void _r_debug_postinit(struct link_map *) __noinline __exported;
199 int __sys_openat(int, const char *, int, ...);
204 struct r_debug r_debug __exported; /* for GDB; */
205 static bool libmap_disable; /* Disable libmap */
206 static bool ld_loadfltr; /* Immediate filters processing */
207 static const char *libmap_override;/* Maps to use in addition to libmap.conf */
208 static bool trust; /* False for setuid and setgid programs */
209 static bool dangerous_ld_env; /* True if environment variables have been
210 used to affect the libraries loaded */
211 bool ld_bind_not; /* Disable PLT update */
212 static const char *ld_bind_now; /* Environment variable for immediate binding */
213 static const char *ld_debug; /* Environment variable for debugging */
214 static bool ld_dynamic_weak = true; /* True if non-weak definition overrides
216 static const char *ld_library_path;/* Environment variable for search path */
217 static const char *ld_library_dirs;/* Environment variable for library descriptors */
218 static const char *ld_preload; /* Environment variable for libraries to
220 static const char *ld_preload_fds;/* Environment variable for libraries represented by
222 static const char *ld_elf_hints_path; /* Environment variable for alternative hints path */
223 static const char *ld_tracing; /* Called from ldd to print libs */
224 static const char *ld_utrace; /* Use utrace() to log events. */
225 static struct obj_entry_q obj_list; /* Queue of all loaded objects */
226 static Obj_Entry *obj_main; /* The main program shared object */
227 static Obj_Entry obj_rtld; /* The dynamic linker shared object */
228 static unsigned int obj_count; /* Number of objects in obj_list */
229 static unsigned int obj_loads; /* Number of loads of objects (gen count) */
231 static Objlist list_global = /* Objects dlopened with RTLD_GLOBAL */
232 STAILQ_HEAD_INITIALIZER(list_global);
233 static Objlist list_main = /* Objects loaded at program startup */
234 STAILQ_HEAD_INITIALIZER(list_main);
235 static Objlist list_fini = /* Objects needing fini() calls */
236 STAILQ_HEAD_INITIALIZER(list_fini);
238 Elf_Sym sym_zero; /* For resolving undefined weak refs. */
240 #define GDB_STATE(s,m) r_debug.r_state = s; r_debug_state(&r_debug,m);
242 extern Elf_Dyn _DYNAMIC;
243 #pragma weak _DYNAMIC
245 int dlclose(void *) __exported;
246 char *dlerror(void) __exported;
247 void *dlopen(const char *, int) __exported;
248 void *fdlopen(int, int) __exported;
249 void *dlsym(void *, const char *) __exported;
250 dlfunc_t dlfunc(void *, const char *) __exported;
251 void *dlvsym(void *, const char *, const char *) __exported;
252 int dladdr(const void *, Dl_info *) __exported;
253 void dllockinit(void *, void *(*)(void *), void (*)(void *), void (*)(void *),
254 void (*)(void *), void (*)(void *), void (*)(void *)) __exported;
255 int dlinfo(void *, int , void *) __exported;
256 int dl_iterate_phdr(__dl_iterate_hdr_callback, void *) __exported;
257 int _rtld_addr_phdr(const void *, struct dl_phdr_info *) __exported;
258 int _rtld_get_stack_prot(void) __exported;
259 int _rtld_is_dlopened(void *) __exported;
260 void _rtld_error(const char *, ...) __exported;
262 /* Only here to fix -Wmissing-prototypes warnings */
263 int __getosreldate(void);
264 func_ptr_type _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp);
265 Elf_Addr _rtld_bind(Obj_Entry *obj, Elf_Size reloff);
269 static int osreldate;
272 static int stack_prot = PROT_READ | PROT_WRITE | RTLD_DEFAULT_STACK_EXEC;
273 static int max_stack_flags;
276 * Global declarations normally provided by crt1. The dynamic linker is
277 * not built with crt1, so we have to provide them ourselves.
283 * Used to pass argc, argv to init functions.
289 * Globals to control TLS allocation.
291 size_t tls_last_offset; /* Static TLS offset of last module */
292 size_t tls_last_size; /* Static TLS size of last module */
293 size_t tls_static_space; /* Static TLS space allocated */
294 static size_t tls_static_max_align;
295 Elf_Addr tls_dtv_generation = 1; /* Used to detect when dtv size changes */
296 int tls_max_index = 1; /* Largest module index allocated */
298 static bool ld_library_path_rpath = false;
299 bool ld_fast_sigblock = false;
302 * Globals for path names, and such
304 const char *ld_elf_hints_default = _PATH_ELF_HINTS;
305 const char *ld_path_libmap_conf = _PATH_LIBMAP_CONF;
306 const char *ld_path_rtld = _PATH_RTLD;
307 const char *ld_standard_library_path = STANDARD_LIBRARY_PATH;
308 const char *ld_env_prefix = LD_;
310 static void (*rtld_exit_ptr)(void);
313 * Fill in a DoneList with an allocation large enough to hold all of
314 * the currently-loaded objects. Keep this as a macro since it calls
315 * alloca and we want that to occur within the scope of the caller.
317 #define donelist_init(dlp) \
318 ((dlp)->objs = alloca(obj_count * sizeof (dlp)->objs[0]), \
319 assert((dlp)->objs != NULL), \
320 (dlp)->num_alloc = obj_count, \
323 #define LD_UTRACE(e, h, mb, ms, r, n) do { \
324 if (ld_utrace != NULL) \
325 ld_utrace_log(e, h, mb, ms, r, n); \
329 ld_utrace_log(int event, void *handle, void *mapbase, size_t mapsize,
330 int refcnt, const char *name)
332 struct utrace_rtld ut;
333 static const char rtld_utrace_sig[RTLD_UTRACE_SIG_SZ] = RTLD_UTRACE_SIG;
335 memcpy(ut.sig, rtld_utrace_sig, sizeof(ut.sig));
338 ut.mapbase = mapbase;
339 ut.mapsize = mapsize;
341 bzero(ut.name, sizeof(ut.name));
343 strlcpy(ut.name, name, sizeof(ut.name));
344 utrace(&ut, sizeof(ut));
358 LD_LIBRARY_PATH_RPATH,
361 LD_TRACE_LOADED_OBJECTS,
365 LD_TRACE_LOADED_OBJECTS_PROGNAME,
366 LD_TRACE_LOADED_OBJECTS_FMT1,
367 LD_TRACE_LOADED_OBJECTS_FMT2,
368 LD_TRACE_LOADED_OBJECTS_ALL,
372 struct ld_env_var_desc {
373 const char * const n;
377 #define LD_ENV_DESC(var, unsec) \
378 [LD_##var] = { .n = #var, .unsecure = unsec }
380 static struct ld_env_var_desc ld_env_vars[] = {
381 LD_ENV_DESC(BIND_NOW, false),
382 LD_ENV_DESC(PRELOAD, true),
383 LD_ENV_DESC(LIBMAP, true),
384 LD_ENV_DESC(LIBRARY_PATH, true),
385 LD_ENV_DESC(LIBRARY_PATH_FDS, true),
386 LD_ENV_DESC(LIBMAP_DISABLE, true),
387 LD_ENV_DESC(BIND_NOT, true),
388 LD_ENV_DESC(DEBUG, true),
389 LD_ENV_DESC(ELF_HINTS_PATH, true),
390 LD_ENV_DESC(LOADFLTR, true),
391 LD_ENV_DESC(LIBRARY_PATH_RPATH, true),
392 LD_ENV_DESC(PRELOAD_FDS, true),
393 LD_ENV_DESC(DYNAMIC_WEAK, true),
394 LD_ENV_DESC(TRACE_LOADED_OBJECTS, false),
395 LD_ENV_DESC(UTRACE, false),
396 LD_ENV_DESC(DUMP_REL_PRE, false),
397 LD_ENV_DESC(DUMP_REL_POST, false),
398 LD_ENV_DESC(TRACE_LOADED_OBJECTS_PROGNAME, false),
399 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT1, false),
400 LD_ENV_DESC(TRACE_LOADED_OBJECTS_FMT2, false),
401 LD_ENV_DESC(TRACE_LOADED_OBJECTS_ALL, false),
402 LD_ENV_DESC(SHOW_AUXV, false),
406 ld_get_env_var(int idx)
408 return (ld_env_vars[idx].val);
412 rtld_get_env_val(char **env, const char *name, size_t name_len)
416 for (m = env; *m != NULL; m++) {
420 /* corrupt environment? */
423 if (v - n == (ptrdiff_t)name_len &&
424 strncmp(name, n, name_len) == 0)
431 rtld_init_env_vars_for_prefix(char **env, const char *env_prefix)
433 struct ld_env_var_desc *lvd;
434 size_t prefix_len, nlen;
438 prefix_len = strlen(env_prefix);
439 for (m = env; *m != NULL; m++) {
441 if (strncmp(env_prefix, n, prefix_len) != 0) {
442 /* Not a rtld environment variable. */
448 /* corrupt environment? */
451 for (i = 0; i < (int)nitems(ld_env_vars); i++) {
452 lvd = &ld_env_vars[i];
453 if (lvd->val != NULL) {
454 /* Saw higher-priority variable name already. */
457 nlen = strlen(lvd->n);
458 if (v - n == (ptrdiff_t)nlen &&
459 strncmp(lvd->n, n, nlen) == 0) {
468 rtld_init_env_vars(char **env)
470 rtld_init_env_vars_for_prefix(env, ld_env_prefix);
474 set_ld_elf_hints_path(void)
476 if (ld_elf_hints_path == NULL || strlen(ld_elf_hints_path) == 0)
477 ld_elf_hints_path = ld_elf_hints_default;
481 * Main entry point for dynamic linking. The first argument is the
482 * stack pointer. The stack is expected to be laid out as described
483 * in the SVR4 ABI specification, Intel 386 Processor Supplement.
484 * Specifically, the stack pointer points to a word containing
485 * ARGC. Following that in the stack is a null-terminated sequence
486 * of pointers to argument strings. Then comes a null-terminated
487 * sequence of pointers to environment strings. Finally, there is a
488 * sequence of "auxiliary vector" entries.
490 * The second argument points to a place to store the dynamic linker's
491 * exit procedure pointer and the third to a place to store the main
494 * The return value is the main program's entry point.
497 _rtld(Elf_Addr *sp, func_ptr_type *exit_proc, Obj_Entry **objp)
499 Elf_Auxinfo *aux, *auxp, *auxpf, *aux_info[AT_COUNT];
500 Objlist_Entry *entry;
501 Obj_Entry *last_interposer, *obj, *preload_tail;
502 const Elf_Phdr *phdr;
504 RtldLockState lockstate;
507 char **argv, **env, **envp, *kexecpath;
508 const char *argv0, *binpath, *library_path_rpath;
509 struct ld_env_var_desc *lvd;
511 char buf[MAXPATHLEN];
512 int argc, fd, i, mib[4], old_osrel, osrel, phnum, rtld_argc;
515 int old_auxv_format = 1;
517 bool dir_enable, dir_ignore, direct_exec, explicit_fd, search_in_path;
520 * On entry, the dynamic linker itself has not been relocated yet.
521 * Be very careful not to reference any global data until after
522 * init_rtld has returned. It is OK to reference file-scope statics
523 * and string constants, and to call static and global functions.
526 /* Find the auxiliary vector on the stack. */
530 sp += argc + 1; /* Skip over arguments and NULL terminator */
532 while (*sp++ != 0) /* Skip over environment, and NULL terminator */
534 aux = (Elf_Auxinfo *) sp;
536 /* Digest the auxiliary vector. */
537 for (i = 0; i < AT_COUNT; i++)
539 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
540 if (auxp->a_type < AT_COUNT)
541 aux_info[auxp->a_type] = auxp;
543 if (auxp->a_type == 23) /* AT_STACKPROT */
549 if (old_auxv_format) {
550 /* Remap from old-style auxv numbers. */
551 aux_info[23] = aux_info[21]; /* AT_STACKPROT */
552 aux_info[21] = aux_info[19]; /* AT_PAGESIZESLEN */
553 aux_info[19] = aux_info[17]; /* AT_NCPUS */
554 aux_info[17] = aux_info[15]; /* AT_CANARYLEN */
555 aux_info[15] = aux_info[13]; /* AT_EXECPATH */
556 aux_info[13] = NULL; /* AT_GID */
558 aux_info[20] = aux_info[18]; /* AT_PAGESIZES */
559 aux_info[18] = aux_info[16]; /* AT_OSRELDATE */
560 aux_info[16] = aux_info[14]; /* AT_CANARY */
561 aux_info[14] = NULL; /* AT_EGID */
565 /* Initialize and relocate ourselves. */
566 assert(aux_info[AT_BASE] != NULL);
567 init_rtld((caddr_t) aux_info[AT_BASE]->a_un.a_ptr, aux_info);
571 __progname = obj_rtld.path;
572 argv0 = argv[0] != NULL ? argv[0] : "(null)";
577 if (aux_info[AT_BSDFLAGS] != NULL &&
578 (aux_info[AT_BSDFLAGS]->a_un.a_val & ELF_BSDF_SIGFASTBLK) != 0)
579 ld_fast_sigblock = true;
581 trust = !issetugid();
584 md_abi_variant_hook(aux_info);
585 rtld_init_env_vars(env);
588 if (aux_info[AT_EXECFD] != NULL) {
589 fd = aux_info[AT_EXECFD]->a_un.a_val;
591 assert(aux_info[AT_PHDR] != NULL);
592 phdr = (const Elf_Phdr *)aux_info[AT_PHDR]->a_un.a_ptr;
593 if (phdr == obj_rtld.phdr) {
595 _rtld_error("Tainted process refusing to run binary %s",
601 dbg("opening main program in direct exec mode");
603 rtld_argc = parse_args(argv, argc, &search_in_path, &fd,
604 &argv0, &dir_ignore);
605 explicit_fd = (fd != -1);
608 fd = open_binary_fd(argv0, search_in_path, &binpath);
609 if (fstat(fd, &st) == -1) {
610 _rtld_error("Failed to fstat FD %d (%s): %s", fd,
611 explicit_fd ? "user-provided descriptor" : argv0,
612 rtld_strerror(errno));
617 * Rough emulation of the permission checks done by
618 * execve(2), only Unix DACs are checked, ACLs are
619 * ignored. Preserve the semantic of disabling owner
620 * to execute if owner x bit is cleared, even if
621 * others x bit is enabled.
622 * mmap(2) does not allow to mmap with PROT_EXEC if
623 * binary' file comes from noexec mount. We cannot
624 * set a text reference on the binary.
627 if (st.st_uid == geteuid()) {
628 if ((st.st_mode & S_IXUSR) != 0)
630 } else if (st.st_gid == getegid()) {
631 if ((st.st_mode & S_IXGRP) != 0)
633 } else if ((st.st_mode & S_IXOTH) != 0) {
636 if (!dir_enable && !dir_ignore) {
637 _rtld_error("No execute permission for binary %s",
643 * For direct exec mode, argv[0] is the interpreter
644 * name, we must remove it and shift arguments left
645 * before invoking binary main. Since stack layout
646 * places environment pointers and aux vectors right
647 * after the terminating NULL, we must shift
648 * environment and aux as well.
650 main_argc = argc - rtld_argc;
651 for (i = 0; i <= main_argc; i++)
652 argv[i] = argv[i + rtld_argc];
654 environ = env = envp = argv + main_argc + 1;
655 dbg("move env from %p to %p", envp + rtld_argc, envp);
657 *envp = *(envp + rtld_argc);
658 } while (*envp++ != NULL);
659 aux = auxp = (Elf_Auxinfo *)envp;
660 auxpf = (Elf_Auxinfo *)(envp + rtld_argc);
661 dbg("move aux from %p to %p", auxpf, aux);
662 /* XXXKIB insert place for AT_EXECPATH if not present */
663 for (;; auxp++, auxpf++) {
665 if (auxp->a_type == AT_NULL)
668 /* Since the auxiliary vector has moved, redigest it. */
669 for (i = 0; i < AT_COUNT; i++)
671 for (auxp = aux; auxp->a_type != AT_NULL; auxp++) {
672 if (auxp->a_type < AT_COUNT)
673 aux_info[auxp->a_type] = auxp;
676 /* Point AT_EXECPATH auxv and aux_info to the binary path. */
677 if (binpath == NULL) {
678 aux_info[AT_EXECPATH] = NULL;
680 if (aux_info[AT_EXECPATH] == NULL) {
681 aux_info[AT_EXECPATH] = xmalloc(sizeof(Elf_Auxinfo));
682 aux_info[AT_EXECPATH]->a_type = AT_EXECPATH;
684 aux_info[AT_EXECPATH]->a_un.a_ptr = __DECONST(void *,
688 _rtld_error("No binary");
694 ld_bind_now = ld_get_env_var(LD_BIND_NOW);
697 * If the process is tainted, then we un-set the dangerous environment
698 * variables. The process will be marked as tainted until setuid(2)
699 * is called. If any child process calls setuid(2) we do not want any
700 * future processes to honor the potentially un-safe variables.
703 for (i = 0; i < (int)nitems(ld_env_vars); i++) {
704 lvd = &ld_env_vars[i];
710 ld_debug = ld_get_env_var(LD_DEBUG);
711 if (ld_bind_now == NULL)
712 ld_bind_not = ld_get_env_var(LD_BIND_NOT) != NULL;
713 ld_dynamic_weak = ld_get_env_var(LD_DYNAMIC_WEAK) == NULL;
714 libmap_disable = ld_get_env_var(LD_LIBMAP_DISABLE) != NULL;
715 libmap_override = ld_get_env_var(LD_LIBMAP);
716 ld_library_path = ld_get_env_var(LD_LIBRARY_PATH);
717 ld_library_dirs = ld_get_env_var(LD_LIBRARY_PATH_FDS);
718 ld_preload = ld_get_env_var(LD_PRELOAD);
719 ld_preload_fds = ld_get_env_var(LD_PRELOAD_FDS);
720 ld_elf_hints_path = ld_get_env_var(LD_ELF_HINTS_PATH);
721 ld_loadfltr = ld_get_env_var(LD_LOADFLTR) != NULL;
722 library_path_rpath = ld_get_env_var(LD_LIBRARY_PATH_RPATH);
723 if (library_path_rpath != NULL) {
724 if (library_path_rpath[0] == 'y' ||
725 library_path_rpath[0] == 'Y' ||
726 library_path_rpath[0] == '1')
727 ld_library_path_rpath = true;
729 ld_library_path_rpath = false;
731 dangerous_ld_env = libmap_disable || libmap_override != NULL ||
732 ld_library_path != NULL || ld_preload != NULL ||
733 ld_elf_hints_path != NULL || ld_loadfltr || !ld_dynamic_weak;
734 ld_tracing = ld_get_env_var(LD_TRACE_LOADED_OBJECTS);
735 ld_utrace = ld_get_env_var(LD_UTRACE);
737 set_ld_elf_hints_path();
738 if (ld_debug != NULL && *ld_debug != '\0')
740 dbg("%s is initialized, base address = %p", __progname,
741 (caddr_t) aux_info[AT_BASE]->a_un.a_ptr);
742 dbg("RTLD dynamic = %p", obj_rtld.dynamic);
743 dbg("RTLD pltgot = %p", obj_rtld.pltgot);
745 dbg("initializing thread locks");
749 * Load the main program, or process its program header if it is
752 if (fd != -1) { /* Load the main program. */
753 dbg("loading main program");
754 obj_main = map_object(fd, argv0, NULL);
756 if (obj_main == NULL)
758 max_stack_flags = obj_main->stack_flags;
759 } else { /* Main program already loaded. */
760 dbg("processing main program's program header");
761 assert(aux_info[AT_PHDR] != NULL);
762 phdr = (const Elf_Phdr *) aux_info[AT_PHDR]->a_un.a_ptr;
763 assert(aux_info[AT_PHNUM] != NULL);
764 phnum = aux_info[AT_PHNUM]->a_un.a_val;
765 assert(aux_info[AT_PHENT] != NULL);
766 assert(aux_info[AT_PHENT]->a_un.a_val == sizeof(Elf_Phdr));
767 assert(aux_info[AT_ENTRY] != NULL);
768 imgentry = (caddr_t) aux_info[AT_ENTRY]->a_un.a_ptr;
769 if ((obj_main = digest_phdr(phdr, phnum, imgentry, argv0)) == NULL)
773 if (aux_info[AT_EXECPATH] != NULL && fd == -1) {
774 kexecpath = aux_info[AT_EXECPATH]->a_un.a_ptr;
775 dbg("AT_EXECPATH %p %s", kexecpath, kexecpath);
776 if (kexecpath[0] == '/')
777 obj_main->path = kexecpath;
778 else if (getcwd(buf, sizeof(buf)) == NULL ||
779 strlcat(buf, "/", sizeof(buf)) >= sizeof(buf) ||
780 strlcat(buf, kexecpath, sizeof(buf)) >= sizeof(buf))
781 obj_main->path = xstrdup(argv0);
783 obj_main->path = xstrdup(buf);
785 dbg("No AT_EXECPATH or direct exec");
786 obj_main->path = xstrdup(argv0);
788 dbg("obj_main path %s", obj_main->path);
789 obj_main->mainprog = true;
791 if (aux_info[AT_STACKPROT] != NULL &&
792 aux_info[AT_STACKPROT]->a_un.a_val != 0)
793 stack_prot = aux_info[AT_STACKPROT]->a_un.a_val;
797 * Get the actual dynamic linker pathname from the executable if
798 * possible. (It should always be possible.) That ensures that
799 * gdb will find the right dynamic linker even if a non-standard
802 if (obj_main->interp != NULL &&
803 strcmp(obj_main->interp, obj_rtld.path) != 0) {
805 obj_rtld.path = xstrdup(obj_main->interp);
806 __progname = obj_rtld.path;
810 if (!digest_dynamic(obj_main, 0))
812 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d",
813 obj_main->path, obj_main->valid_hash_sysv, obj_main->valid_hash_gnu,
814 obj_main->dynsymcount);
816 linkmap_add(obj_main);
817 linkmap_add(&obj_rtld);
819 /* Link the main program into the list of objects. */
820 TAILQ_INSERT_HEAD(&obj_list, obj_main, next);
824 /* Initialize a fake symbol for resolving undefined weak references. */
825 sym_zero.st_info = ELF_ST_INFO(STB_GLOBAL, STT_NOTYPE);
826 sym_zero.st_shndx = SHN_UNDEF;
827 sym_zero.st_value = -(uintptr_t)obj_main->relocbase;
830 libmap_disable = (bool)lm_init(libmap_override);
832 if (aux_info[AT_KPRELOAD] != NULL &&
833 aux_info[AT_KPRELOAD]->a_un.a_ptr != NULL) {
834 dbg("loading kernel vdso");
835 if (load_kpreload(aux_info[AT_KPRELOAD]->a_un.a_ptr) == -1)
839 dbg("loading LD_PRELOAD_FDS libraries");
840 if (load_preload_objects(ld_preload_fds, true) == -1)
843 dbg("loading LD_PRELOAD libraries");
844 if (load_preload_objects(ld_preload, false) == -1)
846 preload_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q));
848 dbg("loading needed objects");
849 if (load_needed_objects(obj_main, ld_tracing != NULL ? RTLD_LO_TRACE :
853 /* Make a list of all objects loaded at startup. */
854 last_interposer = obj_main;
855 TAILQ_FOREACH(obj, &obj_list, next) {
858 if (obj->z_interpose && obj != obj_main) {
859 objlist_put_after(&list_main, last_interposer, obj);
860 last_interposer = obj;
862 objlist_push_tail(&list_main, obj);
867 dbg("checking for required versions");
868 if (rtld_verify_versions(&list_main) == -1 && !ld_tracing)
871 if (ld_get_env_var(LD_SHOW_AUXV) != NULL)
874 if (ld_tracing) { /* We're done */
875 trace_loaded_objects(obj_main, true);
879 if (ld_get_env_var(LD_DUMP_REL_PRE) != NULL) {
880 dump_relocations(obj_main);
885 * Processing tls relocations requires having the tls offsets
886 * initialized. Prepare offsets before starting initial
887 * relocation processing.
889 dbg("initializing initial thread local storage offsets");
890 STAILQ_FOREACH(entry, &list_main, link) {
892 * Allocate all the initial objects out of the static TLS
893 * block even if they didn't ask for it.
895 allocate_tls_offset(entry->obj);
898 if (relocate_objects(obj_main,
899 ld_bind_now != NULL && *ld_bind_now != '\0',
900 &obj_rtld, SYMLOOK_EARLY, NULL) == -1)
903 dbg("doing copy relocations");
904 if (do_copy_relocations(obj_main) == -1)
907 if (ld_get_env_var(LD_DUMP_REL_POST) != NULL) {
908 dump_relocations(obj_main);
915 * Setup TLS for main thread. This must be done after the
916 * relocations are processed, since tls initialization section
917 * might be the subject for relocations.
919 dbg("initializing initial thread local storage");
920 allocate_initial_tls(globallist_curr(TAILQ_FIRST(&obj_list)));
922 dbg("initializing key program variables");
923 set_program_var("__progname", argv[0] != NULL ? basename(argv[0]) : "");
924 set_program_var("environ", env);
925 set_program_var("__elf_aux_vector", aux);
927 /* Make a list of init functions to call. */
928 objlist_init(&initlist);
929 initlist_add_objects(globallist_curr(TAILQ_FIRST(&obj_list)),
930 preload_tail, &initlist);
932 r_debug_state(NULL, &obj_main->linkmap); /* say hello to gdb! */
934 map_stacks_exec(NULL);
936 if (!obj_main->crt_no_init) {
938 * Make sure we don't call the main program's init and fini
939 * functions for binaries linked with old crt1 which calls
942 obj_main->init = obj_main->fini = (Elf_Addr)NULL;
943 obj_main->preinit_array = obj_main->init_array =
944 obj_main->fini_array = (Elf_Addr)NULL;
948 /* Set osrel for direct-execed binary */
951 mib[2] = KERN_PROC_OSREL;
953 osrel = obj_main->osrel;
954 sz = sizeof(old_osrel);
955 dbg("setting osrel to %d", osrel);
956 (void)sysctl(mib, 4, &old_osrel, &sz, &osrel, sizeof(osrel));
959 wlock_acquire(rtld_bind_lock, &lockstate);
961 dbg("resolving ifuncs");
962 if (initlist_objects_ifunc(&initlist, ld_bind_now != NULL &&
963 *ld_bind_now != '\0', SYMLOOK_EARLY, &lockstate) == -1)
966 rtld_exit_ptr = rtld_exit;
967 if (obj_main->crt_no_init)
969 objlist_call_init(&initlist, &lockstate);
970 _r_debug_postinit(&obj_main->linkmap);
971 objlist_clear(&initlist);
972 dbg("loading filtees");
973 TAILQ_FOREACH(obj, &obj_list, next) {
976 if (ld_loadfltr || obj->z_loadfltr)
977 load_filtees(obj, 0, &lockstate);
980 dbg("enforcing main obj relro");
981 if (obj_enforce_relro(obj_main) == -1)
984 lock_release(rtld_bind_lock, &lockstate);
986 dbg("transferring control to program entry point = %p", obj_main->entry);
988 /* Return the exit procedure and the program entry point. */
989 *exit_proc = rtld_exit_ptr;
991 return ((func_ptr_type)obj_main->entry);
995 rtld_resolve_ifunc(const Obj_Entry *obj, const Elf_Sym *def)
1000 ptr = (void *)make_function_pointer(def, obj);
1001 target = call_ifunc_resolver(ptr);
1002 return ((void *)target);
1006 _rtld_bind(Obj_Entry *obj, Elf_Size reloff)
1010 const Obj_Entry *defobj;
1013 RtldLockState lockstate;
1015 rlock_acquire(rtld_bind_lock, &lockstate);
1016 if (sigsetjmp(lockstate.env, 0) != 0)
1017 lock_upgrade(rtld_bind_lock, &lockstate);
1019 rel = (const Elf_Rel *)((const char *)obj->pltrel + reloff);
1021 rel = (const Elf_Rel *)((const char *)obj->pltrela + reloff);
1023 where = (Elf_Addr *)(obj->relocbase + rel->r_offset);
1024 def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, SYMLOOK_IN_PLT,
1028 if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
1029 target = (Elf_Addr)rtld_resolve_ifunc(defobj, def);
1031 target = (Elf_Addr)(defobj->relocbase + def->st_value);
1033 dbg("\"%s\" in \"%s\" ==> %p in \"%s\"",
1034 defobj->strtab + def->st_name,
1035 obj->path == NULL ? NULL : basename(obj->path),
1037 defobj->path == NULL ? NULL : basename(defobj->path));
1040 * Write the new contents for the jmpslot. Note that depending on
1041 * architecture, the value which we need to return back to the
1042 * lazy binding trampoline may or may not be the target
1043 * address. The value returned from reloc_jmpslot() is the value
1044 * that the trampoline needs.
1046 target = reloc_jmpslot(where, target, defobj, obj, rel);
1047 lock_release(rtld_bind_lock, &lockstate);
1052 * Error reporting function. Use it like printf. If formats the message
1053 * into a buffer, and sets things up so that the next call to dlerror()
1054 * will return the message.
1057 _rtld_error(const char *fmt, ...)
1062 rtld_vsnprintf(lockinfo.dlerror_loc(), lockinfo.dlerror_loc_sz,
1065 *lockinfo.dlerror_seen() = 0;
1066 LD_UTRACE(UTRACE_RTLD_ERROR, NULL, NULL, 0, 0, lockinfo.dlerror_loc());
1070 * Return a dynamically-allocated copy of the current error message, if any.
1072 static struct dlerror_save *
1075 struct dlerror_save *res;
1077 res = xmalloc(sizeof(*res));
1078 res->seen = *lockinfo.dlerror_seen();
1080 res->msg = xstrdup(lockinfo.dlerror_loc());
1085 * Restore the current error message from a copy which was previously saved
1086 * by errmsg_save(). The copy is freed.
1089 errmsg_restore(struct dlerror_save *saved_msg)
1091 if (saved_msg == NULL || saved_msg->seen == 1) {
1092 *lockinfo.dlerror_seen() = 1;
1094 *lockinfo.dlerror_seen() = 0;
1095 strlcpy(lockinfo.dlerror_loc(), saved_msg->msg,
1096 lockinfo.dlerror_loc_sz);
1097 free(saved_msg->msg);
1103 basename(const char *name)
1107 p = strrchr(name, '/');
1108 return (p != NULL ? p + 1 : name);
1111 static struct utsname uts;
1114 origin_subst_one(Obj_Entry *obj, char *real, const char *kw,
1115 const char *subst, bool may_free)
1117 char *p, *p1, *res, *resp;
1118 int subst_len, kw_len, subst_count, old_len, new_len;
1120 kw_len = strlen(kw);
1123 * First, count the number of the keyword occurrences, to
1124 * preallocate the final string.
1126 for (p = real, subst_count = 0;; p = p1 + kw_len, subst_count++) {
1133 * If the keyword is not found, just return.
1135 * Return non-substituted string if resolution failed. We
1136 * cannot do anything more reasonable, the failure mode of the
1137 * caller is unresolved library anyway.
1139 if (subst_count == 0 || (obj != NULL && !obj_resolve_origin(obj)))
1140 return (may_free ? real : xstrdup(real));
1142 subst = obj->origin_path;
1145 * There is indeed something to substitute. Calculate the
1146 * length of the resulting string, and allocate it.
1148 subst_len = strlen(subst);
1149 old_len = strlen(real);
1150 new_len = old_len + (subst_len - kw_len) * subst_count;
1151 res = xmalloc(new_len + 1);
1154 * Now, execute the substitution loop.
1156 for (p = real, resp = res, *resp = '\0';;) {
1159 /* Copy the prefix before keyword. */
1160 memcpy(resp, p, p1 - p);
1162 /* Keyword replacement. */
1163 memcpy(resp, subst, subst_len);
1171 /* Copy to the end of string and finish. */
1178 static const struct {
1183 { .kw = "$ORIGIN", .pass_obj = true, .subst = NULL },
1184 { .kw = "${ORIGIN}", .pass_obj = true, .subst = NULL },
1185 { .kw = "$OSNAME", .pass_obj = false, .subst = uts.sysname },
1186 { .kw = "${OSNAME}", .pass_obj = false, .subst = uts.sysname },
1187 { .kw = "$OSREL", .pass_obj = false, .subst = uts.release },
1188 { .kw = "${OSREL}", .pass_obj = false, .subst = uts.release },
1189 { .kw = "$PLATFORM", .pass_obj = false, .subst = uts.machine },
1190 { .kw = "${PLATFORM}", .pass_obj = false, .subst = uts.machine },
1194 origin_subst(Obj_Entry *obj, const char *real)
1199 if (obj == NULL || !trust)
1200 return (xstrdup(real));
1201 if (uts.sysname[0] == '\0') {
1202 if (uname(&uts) != 0) {
1203 _rtld_error("utsname failed: %d", errno);
1208 /* __DECONST is safe here since without may_free real is unchanged */
1209 res = __DECONST(char *, real);
1210 for (i = 0; i < (int)nitems(tokens); i++) {
1211 res = origin_subst_one(tokens[i].pass_obj ? obj : NULL,
1212 res, tokens[i].kw, tokens[i].subst, i == 0);
1220 const char *msg = dlerror();
1223 msg = "Fatal error";
1224 rtld_fdputstr(STDERR_FILENO, _BASENAME_RTLD ": ");
1225 rtld_fdputstr(STDERR_FILENO, msg);
1226 rtld_fdputchar(STDERR_FILENO, '\n');
1231 * Process a shared object's DYNAMIC section, and save the important
1232 * information in its Obj_Entry structure.
1235 digest_dynamic1(Obj_Entry *obj, int early, const Elf_Dyn **dyn_rpath,
1236 const Elf_Dyn **dyn_soname, const Elf_Dyn **dyn_runpath)
1238 const Elf_Dyn *dynp;
1239 Needed_Entry **needed_tail = &obj->needed;
1240 Needed_Entry **needed_filtees_tail = &obj->needed_filtees;
1241 Needed_Entry **needed_aux_filtees_tail = &obj->needed_aux_filtees;
1242 const Elf_Hashelt *hashtab;
1243 const Elf32_Word *hashval;
1244 Elf32_Word bkt, nmaskwords;
1246 int plttype = DT_REL;
1250 *dyn_runpath = NULL;
1252 obj->bind_now = false;
1253 dynp = obj->dynamic;
1256 for (; dynp->d_tag != DT_NULL; dynp++) {
1257 switch (dynp->d_tag) {
1260 obj->rel = (const Elf_Rel *)(obj->relocbase + dynp->d_un.d_ptr);
1264 obj->relsize = dynp->d_un.d_val;
1268 assert(dynp->d_un.d_val == sizeof(Elf_Rel));
1272 obj->pltrel = (const Elf_Rel *)
1273 (obj->relocbase + dynp->d_un.d_ptr);
1277 obj->pltrelsize = dynp->d_un.d_val;
1281 obj->rela = (const Elf_Rela *)(obj->relocbase + dynp->d_un.d_ptr);
1285 obj->relasize = dynp->d_un.d_val;
1289 assert(dynp->d_un.d_val == sizeof(Elf_Rela));
1293 obj->relr = (const Elf_Relr *)(obj->relocbase + dynp->d_un.d_ptr);
1297 obj->relrsize = dynp->d_un.d_val;
1301 assert(dynp->d_un.d_val == sizeof(Elf_Relr));
1305 plttype = dynp->d_un.d_val;
1306 assert(dynp->d_un.d_val == DT_REL || plttype == DT_RELA);
1310 obj->symtab = (const Elf_Sym *)
1311 (obj->relocbase + dynp->d_un.d_ptr);
1315 assert(dynp->d_un.d_val == sizeof(Elf_Sym));
1319 obj->strtab = (const char *)(obj->relocbase + dynp->d_un.d_ptr);
1323 obj->strsize = dynp->d_un.d_val;
1327 obj->verneed = (const Elf_Verneed *)(obj->relocbase +
1332 obj->verneednum = dynp->d_un.d_val;
1336 obj->verdef = (const Elf_Verdef *)(obj->relocbase +
1341 obj->verdefnum = dynp->d_un.d_val;
1345 obj->versyms = (const Elf_Versym *)(obj->relocbase +
1351 hashtab = (const Elf_Hashelt *)(obj->relocbase +
1353 obj->nbuckets = hashtab[0];
1354 obj->nchains = hashtab[1];
1355 obj->buckets = hashtab + 2;
1356 obj->chains = obj->buckets + obj->nbuckets;
1357 obj->valid_hash_sysv = obj->nbuckets > 0 && obj->nchains > 0 &&
1358 obj->buckets != NULL;
1364 hashtab = (const Elf_Hashelt *)(obj->relocbase +
1366 obj->nbuckets_gnu = hashtab[0];
1367 obj->symndx_gnu = hashtab[1];
1368 nmaskwords = hashtab[2];
1369 bloom_size32 = (__ELF_WORD_SIZE / 32) * nmaskwords;
1370 obj->maskwords_bm_gnu = nmaskwords - 1;
1371 obj->shift2_gnu = hashtab[3];
1372 obj->bloom_gnu = (const Elf_Addr *)(hashtab + 4);
1373 obj->buckets_gnu = hashtab + 4 + bloom_size32;
1374 obj->chain_zero_gnu = obj->buckets_gnu + obj->nbuckets_gnu -
1376 /* Number of bitmask words is required to be power of 2 */
1377 obj->valid_hash_gnu = powerof2(nmaskwords) &&
1378 obj->nbuckets_gnu > 0 && obj->buckets_gnu != NULL;
1384 Needed_Entry *nep = NEW(Needed_Entry);
1385 nep->name = dynp->d_un.d_val;
1390 needed_tail = &nep->next;
1396 Needed_Entry *nep = NEW(Needed_Entry);
1397 nep->name = dynp->d_un.d_val;
1401 *needed_filtees_tail = nep;
1402 needed_filtees_tail = &nep->next;
1404 if (obj->linkmap.l_refname == NULL)
1405 obj->linkmap.l_refname = (char *)dynp->d_un.d_val;
1411 Needed_Entry *nep = NEW(Needed_Entry);
1412 nep->name = dynp->d_un.d_val;
1416 *needed_aux_filtees_tail = nep;
1417 needed_aux_filtees_tail = &nep->next;
1422 obj->pltgot = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr);
1426 obj->textrel = true;
1430 obj->symbolic = true;
1435 * We have to wait until later to process this, because we
1436 * might not have gotten the address of the string table yet.
1446 *dyn_runpath = dynp;
1450 obj->init = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1453 case DT_PREINIT_ARRAY:
1454 obj->preinit_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1457 case DT_PREINIT_ARRAYSZ:
1458 obj->preinit_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1462 obj->init_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1465 case DT_INIT_ARRAYSZ:
1466 obj->init_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1470 obj->fini = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1474 obj->fini_array = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1477 case DT_FINI_ARRAYSZ:
1478 obj->fini_array_num = dynp->d_un.d_val / sizeof(Elf_Addr);
1483 dbg("Filling in DT_DEBUG entry");
1484 (__DECONST(Elf_Dyn *, dynp))->d_un.d_ptr = (Elf_Addr)&r_debug;
1488 if (dynp->d_un.d_val & DF_ORIGIN)
1489 obj->z_origin = true;
1490 if (dynp->d_un.d_val & DF_SYMBOLIC)
1491 obj->symbolic = true;
1492 if (dynp->d_un.d_val & DF_TEXTREL)
1493 obj->textrel = true;
1494 if (dynp->d_un.d_val & DF_BIND_NOW)
1495 obj->bind_now = true;
1496 if (dynp->d_un.d_val & DF_STATIC_TLS)
1497 obj->static_tls = true;
1501 #ifdef __powerpc64__
1502 case DT_PPC64_GLINK:
1503 obj->glink = (Elf_Addr)(obj->relocbase + dynp->d_un.d_ptr);
1507 obj->gotptr = (Elf_Addr *)(obj->relocbase + dynp->d_un.d_ptr);
1513 if (dynp->d_un.d_val & DF_1_NOOPEN)
1514 obj->z_noopen = true;
1515 if (dynp->d_un.d_val & DF_1_ORIGIN)
1516 obj->z_origin = true;
1517 if (dynp->d_un.d_val & DF_1_GLOBAL)
1518 obj->z_global = true;
1519 if (dynp->d_un.d_val & DF_1_BIND_NOW)
1520 obj->bind_now = true;
1521 if (dynp->d_un.d_val & DF_1_NODELETE)
1522 obj->z_nodelete = true;
1523 if (dynp->d_un.d_val & DF_1_LOADFLTR)
1524 obj->z_loadfltr = true;
1525 if (dynp->d_un.d_val & DF_1_INTERPOSE)
1526 obj->z_interpose = true;
1527 if (dynp->d_un.d_val & DF_1_NODEFLIB)
1528 obj->z_nodeflib = true;
1529 if (dynp->d_un.d_val & DF_1_PIE)
1535 dbg("Ignoring d_tag %ld = %#lx", (long)dynp->d_tag,
1542 obj->traced = false;
1544 if (plttype == DT_RELA) {
1545 obj->pltrela = (const Elf_Rela *) obj->pltrel;
1547 obj->pltrelasize = obj->pltrelsize;
1548 obj->pltrelsize = 0;
1551 /* Determine size of dynsym table (equal to nchains of sysv hash) */
1552 if (obj->valid_hash_sysv)
1553 obj->dynsymcount = obj->nchains;
1554 else if (obj->valid_hash_gnu) {
1555 obj->dynsymcount = 0;
1556 for (bkt = 0; bkt < obj->nbuckets_gnu; bkt++) {
1557 if (obj->buckets_gnu[bkt] == 0)
1559 hashval = &obj->chain_zero_gnu[obj->buckets_gnu[bkt]];
1562 while ((*hashval++ & 1u) == 0);
1564 obj->dynsymcount += obj->symndx_gnu;
1567 if (obj->linkmap.l_refname != NULL)
1568 obj->linkmap.l_refname = obj->strtab + (unsigned long)obj->
1573 obj_resolve_origin(Obj_Entry *obj)
1576 if (obj->origin_path != NULL)
1578 obj->origin_path = xmalloc(PATH_MAX);
1579 return (rtld_dirname_abs(obj->path, obj->origin_path) != -1);
1583 digest_dynamic2(Obj_Entry *obj, const Elf_Dyn *dyn_rpath,
1584 const Elf_Dyn *dyn_soname, const Elf_Dyn *dyn_runpath)
1587 if (obj->z_origin && !obj_resolve_origin(obj))
1590 if (dyn_runpath != NULL) {
1591 obj->runpath = (const char *)obj->strtab + dyn_runpath->d_un.d_val;
1592 obj->runpath = origin_subst(obj, obj->runpath);
1593 } else if (dyn_rpath != NULL) {
1594 obj->rpath = (const char *)obj->strtab + dyn_rpath->d_un.d_val;
1595 obj->rpath = origin_subst(obj, obj->rpath);
1597 if (dyn_soname != NULL)
1598 object_add_name(obj, obj->strtab + dyn_soname->d_un.d_val);
1603 digest_dynamic(Obj_Entry *obj, int early)
1605 const Elf_Dyn *dyn_rpath;
1606 const Elf_Dyn *dyn_soname;
1607 const Elf_Dyn *dyn_runpath;
1609 digest_dynamic1(obj, early, &dyn_rpath, &dyn_soname, &dyn_runpath);
1610 return (digest_dynamic2(obj, dyn_rpath, dyn_soname, dyn_runpath));
1614 * Process a shared object's program header. This is used only for the
1615 * main program, when the kernel has already loaded the main program
1616 * into memory before calling the dynamic linker. It creates and
1617 * returns an Obj_Entry structure.
1620 digest_phdr(const Elf_Phdr *phdr, int phnum, caddr_t entry, const char *path)
1623 const Elf_Phdr *phlimit = phdr + phnum;
1625 Elf_Addr note_start, note_end;
1629 for (ph = phdr; ph < phlimit; ph++) {
1630 if (ph->p_type != PT_PHDR)
1634 obj->phsize = ph->p_memsz;
1635 obj->relocbase = __DECONST(char *, phdr) - ph->p_vaddr;
1639 obj->stack_flags = PF_X | PF_R | PF_W;
1641 for (ph = phdr; ph < phlimit; ph++) {
1642 switch (ph->p_type) {
1645 obj->interp = (const char *)(ph->p_vaddr + obj->relocbase);
1649 if (nsegs == 0) { /* First load segment */
1650 obj->vaddrbase = trunc_page(ph->p_vaddr);
1651 obj->mapbase = obj->vaddrbase + obj->relocbase;
1652 } else { /* Last load segment */
1653 obj->mapsize = round_page(ph->p_vaddr + ph->p_memsz) -
1660 obj->dynamic = (const Elf_Dyn *)(ph->p_vaddr + obj->relocbase);
1665 obj->tlssize = ph->p_memsz;
1666 obj->tlsalign = ph->p_align;
1667 obj->tlsinitsize = ph->p_filesz;
1668 obj->tlsinit = (void*)(ph->p_vaddr + obj->relocbase);
1669 obj->tlspoffset = ph->p_offset;
1673 obj->stack_flags = ph->p_flags;
1677 obj->relro_page = obj->relocbase + trunc_page(ph->p_vaddr);
1678 obj->relro_size = trunc_page(ph->p_vaddr + ph->p_memsz) -
1679 trunc_page(ph->p_vaddr);
1683 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr;
1684 note_end = note_start + ph->p_filesz;
1685 digest_notes(obj, note_start, note_end);
1690 _rtld_error("%s: too few PT_LOAD segments", path);
1699 digest_notes(Obj_Entry *obj, Elf_Addr note_start, Elf_Addr note_end)
1701 const Elf_Note *note;
1702 const char *note_name;
1705 for (note = (const Elf_Note *)note_start; (Elf_Addr)note < note_end;
1706 note = (const Elf_Note *)((const char *)(note + 1) +
1707 roundup2(note->n_namesz, sizeof(Elf32_Addr)) +
1708 roundup2(note->n_descsz, sizeof(Elf32_Addr)))) {
1709 if (note->n_namesz != sizeof(NOTE_FREEBSD_VENDOR) ||
1710 note->n_descsz != sizeof(int32_t))
1712 if (note->n_type != NT_FREEBSD_ABI_TAG &&
1713 note->n_type != NT_FREEBSD_FEATURE_CTL &&
1714 note->n_type != NT_FREEBSD_NOINIT_TAG)
1716 note_name = (const char *)(note + 1);
1717 if (strncmp(NOTE_FREEBSD_VENDOR, note_name,
1718 sizeof(NOTE_FREEBSD_VENDOR)) != 0)
1720 switch (note->n_type) {
1721 case NT_FREEBSD_ABI_TAG:
1722 /* FreeBSD osrel note */
1723 p = (uintptr_t)(note + 1);
1724 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1725 obj->osrel = *(const int32_t *)(p);
1726 dbg("note osrel %d", obj->osrel);
1728 case NT_FREEBSD_FEATURE_CTL:
1729 /* FreeBSD ABI feature control note */
1730 p = (uintptr_t)(note + 1);
1731 p += roundup2(note->n_namesz, sizeof(Elf32_Addr));
1732 obj->fctl0 = *(const uint32_t *)(p);
1733 dbg("note fctl0 %#x", obj->fctl0);
1735 case NT_FREEBSD_NOINIT_TAG:
1736 /* FreeBSD 'crt does not call init' note */
1737 obj->crt_no_init = true;
1738 dbg("note crt_no_init");
1745 dlcheck(void *handle)
1749 TAILQ_FOREACH(obj, &obj_list, next) {
1750 if (obj == (Obj_Entry *) handle)
1754 if (obj == NULL || obj->refcount == 0 || obj->dl_refcount == 0) {
1755 _rtld_error("Invalid shared object handle %p", handle);
1762 * If the given object is already in the donelist, return true. Otherwise
1763 * add the object to the list and return false.
1766 donelist_check(DoneList *dlp, const Obj_Entry *obj)
1770 for (i = 0; i < dlp->num_used; i++)
1771 if (dlp->objs[i] == obj)
1774 * Our donelist allocation should always be sufficient. But if
1775 * our threads locking isn't working properly, more shared objects
1776 * could have been loaded since we allocated the list. That should
1777 * never happen, but we'll handle it properly just in case it does.
1779 if (dlp->num_used < dlp->num_alloc)
1780 dlp->objs[dlp->num_used++] = obj;
1785 * Hash function for symbol table lookup. Don't even think about changing
1786 * this. It is specified by the System V ABI.
1789 elf_hash(const char *name)
1791 const unsigned char *p = (const unsigned char *) name;
1792 unsigned long h = 0;
1795 while (*p != '\0') {
1796 h = (h << 4) + *p++;
1797 if ((g = h & 0xf0000000) != 0)
1805 * The GNU hash function is the Daniel J. Bernstein hash clipped to 32 bits
1806 * unsigned in case it's implemented with a wider type.
1809 gnu_hash(const char *s)
1815 for (c = *s; c != '\0'; c = *++s)
1817 return (h & 0xffffffff);
1822 * Find the library with the given name, and return its full pathname.
1823 * The returned string is dynamically allocated. Generates an error
1824 * message and returns NULL if the library cannot be found.
1826 * If the second argument is non-NULL, then it refers to an already-
1827 * loaded shared object, whose library search path will be searched.
1829 * If a library is successfully located via LD_LIBRARY_PATH_FDS, its
1830 * descriptor (which is close-on-exec) will be passed out via the third
1833 * The search order is:
1834 * DT_RPATH in the referencing file _unless_ DT_RUNPATH is present (1)
1835 * DT_RPATH of the main object if DSO without defined DT_RUNPATH (1)
1837 * DT_RUNPATH in the referencing file
1838 * ldconfig hints (if -z nodefaultlib, filter out default library directories
1840 * /lib:/usr/lib _unless_ the referencing file is linked with -z nodefaultlib
1842 * (1) Handled in digest_dynamic2 - rpath left NULL if runpath defined.
1845 find_library(const char *xname, const Obj_Entry *refobj, int *fdp)
1847 char *pathname, *refobj_path;
1849 bool nodeflib, objgiven;
1851 objgiven = refobj != NULL;
1853 if (libmap_disable || !objgiven ||
1854 (name = lm_find(refobj->path, xname)) == NULL)
1857 if (strchr(name, '/') != NULL) { /* Hard coded pathname */
1858 if (name[0] != '/' && !trust) {
1859 _rtld_error("Absolute pathname required "
1860 "for shared object \"%s\"", name);
1863 return (origin_subst(__DECONST(Obj_Entry *, refobj),
1864 __DECONST(char *, name)));
1867 dbg(" Searching for \"%s\"", name);
1868 refobj_path = objgiven ? refobj->path : NULL;
1871 * If refobj->rpath != NULL, then refobj->runpath is NULL. Fall
1872 * back to pre-conforming behaviour if user requested so with
1873 * LD_LIBRARY_PATH_RPATH environment variable and ignore -z
1876 if (objgiven && refobj->rpath != NULL && ld_library_path_rpath) {
1877 pathname = search_library_path(name, ld_library_path,
1879 if (pathname != NULL)
1881 if (refobj != NULL) {
1882 pathname = search_library_path(name, refobj->rpath,
1884 if (pathname != NULL)
1887 pathname = search_library_pathfds(name, ld_library_dirs, fdp);
1888 if (pathname != NULL)
1890 pathname = search_library_path(name, gethints(false),
1892 if (pathname != NULL)
1894 pathname = search_library_path(name, ld_standard_library_path,
1896 if (pathname != NULL)
1899 nodeflib = objgiven ? refobj->z_nodeflib : false;
1901 pathname = search_library_path(name, refobj->rpath,
1903 if (pathname != NULL)
1906 if (objgiven && refobj->runpath == NULL && refobj != obj_main) {
1907 pathname = search_library_path(name, obj_main->rpath,
1909 if (pathname != NULL)
1912 pathname = search_library_path(name, ld_library_path,
1914 if (pathname != NULL)
1917 pathname = search_library_path(name, refobj->runpath,
1919 if (pathname != NULL)
1922 pathname = search_library_pathfds(name, ld_library_dirs, fdp);
1923 if (pathname != NULL)
1925 pathname = search_library_path(name, gethints(nodeflib),
1927 if (pathname != NULL)
1929 if (objgiven && !nodeflib) {
1930 pathname = search_library_path(name,
1931 ld_standard_library_path, refobj_path, fdp);
1932 if (pathname != NULL)
1937 if (objgiven && refobj->path != NULL) {
1938 _rtld_error("Shared object \"%s\" not found, "
1939 "required by \"%s\"", name, basename(refobj->path));
1941 _rtld_error("Shared object \"%s\" not found", name);
1947 * Given a symbol number in a referencing object, find the corresponding
1948 * definition of the symbol. Returns a pointer to the symbol, or NULL if
1949 * no definition was found. Returns a pointer to the Obj_Entry of the
1950 * defining object via the reference parameter DEFOBJ_OUT.
1953 find_symdef(unsigned long symnum, const Obj_Entry *refobj,
1954 const Obj_Entry **defobj_out, int flags, SymCache *cache,
1955 RtldLockState *lockstate)
1959 const Obj_Entry *defobj;
1960 const Ver_Entry *ve;
1966 * If we have already found this symbol, get the information from
1969 if (symnum >= refobj->dynsymcount)
1970 return (NULL); /* Bad object */
1971 if (cache != NULL && cache[symnum].sym != NULL) {
1972 *defobj_out = cache[symnum].obj;
1973 return (cache[symnum].sym);
1976 ref = refobj->symtab + symnum;
1977 name = refobj->strtab + ref->st_name;
1983 * We don't have to do a full scale lookup if the symbol is local.
1984 * We know it will bind to the instance in this load module; to
1985 * which we already have a pointer (ie ref). By not doing a lookup,
1986 * we not only improve performance, but it also avoids unresolvable
1987 * symbols when local symbols are not in the hash table. This has
1988 * been seen with the ia64 toolchain.
1990 if (ELF_ST_BIND(ref->st_info) != STB_LOCAL) {
1991 if (ELF_ST_TYPE(ref->st_info) == STT_SECTION) {
1992 _rtld_error("%s: Bogus symbol table entry %lu", refobj->path,
1995 symlook_init(&req, name);
1997 ve = req.ventry = fetch_ventry(refobj, symnum);
1998 req.lockstate = lockstate;
1999 res = symlook_default(&req, refobj);
2002 defobj = req.defobj_out;
2010 * If we found no definition and the reference is weak, treat the
2011 * symbol as having the value zero.
2013 if (def == NULL && ELF_ST_BIND(ref->st_info) == STB_WEAK) {
2019 *defobj_out = defobj;
2020 /* Record the information in the cache to avoid subsequent lookups. */
2021 if (cache != NULL) {
2022 cache[symnum].sym = def;
2023 cache[symnum].obj = defobj;
2026 if (refobj != &obj_rtld)
2027 _rtld_error("%s: Undefined symbol \"%s%s%s\"", refobj->path, name,
2028 ve != NULL ? "@" : "", ve != NULL ? ve->name : "");
2034 * Return the search path from the ldconfig hints file, reading it if
2035 * necessary. If nostdlib is true, then the default search paths are
2036 * not added to result.
2038 * Returns NULL if there are problems with the hints file,
2039 * or if the search path there is empty.
2042 gethints(bool nostdlib)
2044 static char *filtered_path;
2045 static const char *hints;
2046 static struct elfhints_hdr hdr;
2047 struct fill_search_info_args sargs, hargs;
2048 struct dl_serinfo smeta, hmeta, *SLPinfo, *hintinfo;
2049 struct dl_serpath *SLPpath, *hintpath;
2051 struct stat hint_stat;
2052 unsigned int SLPndx, hintndx, fndx, fcount;
2058 /* First call, read the hints file */
2059 if (hints == NULL) {
2060 /* Keep from trying again in case the hints file is bad. */
2063 if ((fd = open(ld_elf_hints_path, O_RDONLY | O_CLOEXEC)) == -1)
2067 * Check of hdr.dirlistlen value against type limit
2068 * intends to pacify static analyzers. Further
2069 * paranoia leads to checks that dirlist is fully
2070 * contained in the file range.
2072 if (read(fd, &hdr, sizeof hdr) != sizeof hdr ||
2073 hdr.magic != ELFHINTS_MAGIC ||
2074 hdr.version != 1 || hdr.dirlistlen > UINT_MAX / 2 ||
2075 fstat(fd, &hint_stat) == -1) {
2082 if (dl + hdr.dirlist < dl)
2085 if (dl + hdr.dirlistlen < dl)
2087 dl += hdr.dirlistlen;
2088 if (dl > hint_stat.st_size)
2090 p = xmalloc(hdr.dirlistlen + 1);
2091 if (pread(fd, p, hdr.dirlistlen + 1,
2092 hdr.strtab + hdr.dirlist) != (ssize_t)hdr.dirlistlen + 1 ||
2093 p[hdr.dirlistlen] != '\0') {
2102 * If caller agreed to receive list which includes the default
2103 * paths, we are done. Otherwise, if we still did not
2104 * calculated filtered result, do it now.
2107 return (hints[0] != '\0' ? hints : NULL);
2108 if (filtered_path != NULL)
2112 * Obtain the list of all configured search paths, and the
2113 * list of the default paths.
2115 * First estimate the size of the results.
2117 smeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2119 hmeta.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
2122 sargs.request = RTLD_DI_SERINFOSIZE;
2123 sargs.serinfo = &smeta;
2124 hargs.request = RTLD_DI_SERINFOSIZE;
2125 hargs.serinfo = &hmeta;
2127 path_enumerate(ld_standard_library_path, fill_search_info, NULL,
2129 path_enumerate(hints, fill_search_info, NULL, &hargs);
2131 SLPinfo = xmalloc(smeta.dls_size);
2132 hintinfo = xmalloc(hmeta.dls_size);
2135 * Next fetch both sets of paths.
2137 sargs.request = RTLD_DI_SERINFO;
2138 sargs.serinfo = SLPinfo;
2139 sargs.serpath = &SLPinfo->dls_serpath[0];
2140 sargs.strspace = (char *)&SLPinfo->dls_serpath[smeta.dls_cnt];
2142 hargs.request = RTLD_DI_SERINFO;
2143 hargs.serinfo = hintinfo;
2144 hargs.serpath = &hintinfo->dls_serpath[0];
2145 hargs.strspace = (char *)&hintinfo->dls_serpath[hmeta.dls_cnt];
2147 path_enumerate(ld_standard_library_path, fill_search_info, NULL,
2149 path_enumerate(hints, fill_search_info, NULL, &hargs);
2152 * Now calculate the difference between two sets, by excluding
2153 * standard paths from the full set.
2157 filtered_path = xmalloc(hdr.dirlistlen + 1);
2158 hintpath = &hintinfo->dls_serpath[0];
2159 for (hintndx = 0; hintndx < hmeta.dls_cnt; hintndx++, hintpath++) {
2161 SLPpath = &SLPinfo->dls_serpath[0];
2163 * Check each standard path against current.
2165 for (SLPndx = 0; SLPndx < smeta.dls_cnt; SLPndx++, SLPpath++) {
2166 /* matched, skip the path */
2167 if (!strcmp(hintpath->dls_name, SLPpath->dls_name)) {
2175 * Not matched against any standard path, add the path
2176 * to result. Separate consequtive paths with ':'.
2179 filtered_path[fndx] = ':';
2183 flen = strlen(hintpath->dls_name);
2184 strncpy((filtered_path + fndx), hintpath->dls_name, flen);
2187 filtered_path[fndx] = '\0';
2193 return (filtered_path[0] != '\0' ? filtered_path : NULL);
2197 init_dag(Obj_Entry *root)
2199 const Needed_Entry *needed;
2200 const Objlist_Entry *elm;
2203 if (root->dag_inited)
2205 donelist_init(&donelist);
2207 /* Root object belongs to own DAG. */
2208 objlist_push_tail(&root->dldags, root);
2209 objlist_push_tail(&root->dagmembers, root);
2210 donelist_check(&donelist, root);
2213 * Add dependencies of root object to DAG in breadth order
2214 * by exploiting the fact that each new object get added
2215 * to the tail of the dagmembers list.
2217 STAILQ_FOREACH(elm, &root->dagmembers, link) {
2218 for (needed = elm->obj->needed; needed != NULL; needed = needed->next) {
2219 if (needed->obj == NULL || donelist_check(&donelist, needed->obj))
2221 objlist_push_tail(&needed->obj->dldags, root);
2222 objlist_push_tail(&root->dagmembers, needed->obj);
2225 root->dag_inited = true;
2229 init_marker(Obj_Entry *marker)
2232 bzero(marker, sizeof(*marker));
2233 marker->marker = true;
2237 globallist_curr(const Obj_Entry *obj)
2244 return (__DECONST(Obj_Entry *, obj));
2245 obj = TAILQ_PREV(obj, obj_entry_q, next);
2250 globallist_next(const Obj_Entry *obj)
2254 obj = TAILQ_NEXT(obj, next);
2258 return (__DECONST(Obj_Entry *, obj));
2262 /* Prevent the object from being unmapped while the bind lock is dropped. */
2264 hold_object(Obj_Entry *obj)
2271 unhold_object(Obj_Entry *obj)
2274 assert(obj->holdcount > 0);
2275 if (--obj->holdcount == 0 && obj->unholdfree)
2276 release_object(obj);
2280 process_z(Obj_Entry *root)
2282 const Objlist_Entry *elm;
2286 * Walk over object DAG and process every dependent object
2287 * that is marked as DF_1_NODELETE or DF_1_GLOBAL. They need
2288 * to grow their own DAG.
2290 * For DF_1_GLOBAL, DAG is required for symbol lookups in
2291 * symlook_global() to work.
2293 * For DF_1_NODELETE, the DAG should have its reference upped.
2295 STAILQ_FOREACH(elm, &root->dagmembers, link) {
2299 if (obj->z_nodelete && !obj->ref_nodel) {
2300 dbg("obj %s -z nodelete", obj->path);
2303 obj->ref_nodel = true;
2305 if (obj->z_global && objlist_find(&list_global, obj) == NULL) {
2306 dbg("obj %s -z global", obj->path);
2307 objlist_push_tail(&list_global, obj);
2314 parse_rtld_phdr(Obj_Entry *obj)
2317 Elf_Addr note_start, note_end;
2319 obj->stack_flags = PF_X | PF_R | PF_W;
2320 for (ph = obj->phdr; (const char *)ph < (const char *)obj->phdr +
2321 obj->phsize; ph++) {
2322 switch (ph->p_type) {
2324 obj->stack_flags = ph->p_flags;
2327 obj->relro_page = obj->relocbase +
2328 trunc_page(ph->p_vaddr);
2329 obj->relro_size = round_page(ph->p_memsz);
2332 note_start = (Elf_Addr)obj->relocbase + ph->p_vaddr;
2333 note_end = note_start + ph->p_filesz;
2334 digest_notes(obj, note_start, note_end);
2341 * Initialize the dynamic linker. The argument is the address at which
2342 * the dynamic linker has been mapped into memory. The primary task of
2343 * this function is to relocate the dynamic linker.
2346 init_rtld(caddr_t mapbase, Elf_Auxinfo **aux_info)
2348 Obj_Entry objtmp; /* Temporary rtld object */
2349 const Elf_Ehdr *ehdr;
2350 const Elf_Dyn *dyn_rpath;
2351 const Elf_Dyn *dyn_soname;
2352 const Elf_Dyn *dyn_runpath;
2354 #ifdef RTLD_INIT_PAGESIZES_EARLY
2355 /* The page size is required by the dynamic memory allocator. */
2356 init_pagesizes(aux_info);
2360 * Conjure up an Obj_Entry structure for the dynamic linker.
2362 * The "path" member can't be initialized yet because string constants
2363 * cannot yet be accessed. Below we will set it correctly.
2365 memset(&objtmp, 0, sizeof(objtmp));
2368 objtmp.mapbase = mapbase;
2370 objtmp.relocbase = mapbase;
2373 objtmp.dynamic = rtld_dynamic(&objtmp);
2374 digest_dynamic1(&objtmp, 1, &dyn_rpath, &dyn_soname, &dyn_runpath);
2375 assert(objtmp.needed == NULL);
2376 assert(!objtmp.textrel);
2378 * Temporarily put the dynamic linker entry into the object list, so
2379 * that symbols can be found.
2381 relocate_objects(&objtmp, true, &objtmp, 0, NULL);
2383 ehdr = (Elf_Ehdr *)mapbase;
2384 objtmp.phdr = (Elf_Phdr *)((char *)mapbase + ehdr->e_phoff);
2385 objtmp.phsize = ehdr->e_phnum * sizeof(objtmp.phdr[0]);
2387 /* Initialize the object list. */
2388 TAILQ_INIT(&obj_list);
2390 /* Now that non-local variables can be accesses, copy out obj_rtld. */
2391 memcpy(&obj_rtld, &objtmp, sizeof(obj_rtld));
2393 #ifndef RTLD_INIT_PAGESIZES_EARLY
2394 /* The page size is required by the dynamic memory allocator. */
2395 init_pagesizes(aux_info);
2398 if (aux_info[AT_OSRELDATE] != NULL)
2399 osreldate = aux_info[AT_OSRELDATE]->a_un.a_val;
2401 digest_dynamic2(&obj_rtld, dyn_rpath, dyn_soname, dyn_runpath);
2403 /* Replace the path with a dynamically allocated copy. */
2404 obj_rtld.path = xstrdup(ld_path_rtld);
2406 parse_rtld_phdr(&obj_rtld);
2407 if (obj_enforce_relro(&obj_rtld) == -1)
2410 r_debug.r_version = R_DEBUG_VERSION;
2411 r_debug.r_brk = r_debug_state;
2412 r_debug.r_state = RT_CONSISTENT;
2413 r_debug.r_ldbase = obj_rtld.relocbase;
2417 * Retrieve the array of supported page sizes. The kernel provides the page
2418 * sizes in increasing order.
2421 init_pagesizes(Elf_Auxinfo **aux_info)
2423 static size_t psa[MAXPAGESIZES];
2427 if (aux_info[AT_PAGESIZES] != NULL && aux_info[AT_PAGESIZESLEN] !=
2429 size = aux_info[AT_PAGESIZESLEN]->a_un.a_val;
2430 pagesizes = aux_info[AT_PAGESIZES]->a_un.a_ptr;
2433 if (sysctlnametomib("hw.pagesizes", mib, &len) == 0)
2436 /* As a fallback, retrieve the base page size. */
2437 size = sizeof(psa[0]);
2438 if (aux_info[AT_PAGESZ] != NULL) {
2439 psa[0] = aux_info[AT_PAGESZ]->a_un.a_val;
2443 mib[1] = HW_PAGESIZE;
2447 if (sysctl(mib, len, psa, &size, NULL, 0) == -1) {
2448 _rtld_error("sysctl for hw.pagesize(s) failed");
2454 npagesizes = size / sizeof(pagesizes[0]);
2455 /* Discard any invalid entries at the end of the array. */
2456 while (npagesizes > 0 && pagesizes[npagesizes - 1] == 0)
2461 * Add the init functions from a needed object list (and its recursive
2462 * needed objects) to "list". This is not used directly; it is a helper
2463 * function for initlist_add_objects(). The write lock must be held
2464 * when this function is called.
2467 initlist_add_neededs(Needed_Entry *needed, Objlist *list)
2469 /* Recursively process the successor needed objects. */
2470 if (needed->next != NULL)
2471 initlist_add_neededs(needed->next, list);
2473 /* Process the current needed object. */
2474 if (needed->obj != NULL)
2475 initlist_add_objects(needed->obj, needed->obj, list);
2479 * Scan all of the DAGs rooted in the range of objects from "obj" to
2480 * "tail" and add their init functions to "list". This recurses over
2481 * the DAGs and ensure the proper init ordering such that each object's
2482 * needed libraries are initialized before the object itself. At the
2483 * same time, this function adds the objects to the global finalization
2484 * list "list_fini" in the opposite order. The write lock must be
2485 * held when this function is called.
2488 initlist_add_objects(Obj_Entry *obj, Obj_Entry *tail, Objlist *list)
2492 if (obj->init_scanned || obj->init_done)
2494 obj->init_scanned = true;
2496 /* Recursively process the successor objects. */
2497 nobj = globallist_next(obj);
2498 if (nobj != NULL && obj != tail)
2499 initlist_add_objects(nobj, tail, list);
2501 /* Recursively process the needed objects. */
2502 if (obj->needed != NULL)
2503 initlist_add_neededs(obj->needed, list);
2504 if (obj->needed_filtees != NULL)
2505 initlist_add_neededs(obj->needed_filtees, list);
2506 if (obj->needed_aux_filtees != NULL)
2507 initlist_add_neededs(obj->needed_aux_filtees, list);
2509 /* Add the object to the init list. */
2510 objlist_push_tail(list, obj);
2512 /* Add the object to the global fini list in the reverse order. */
2513 if ((obj->fini != (Elf_Addr)NULL || obj->fini_array != (Elf_Addr)NULL)
2514 && !obj->on_fini_list) {
2515 objlist_push_head(&list_fini, obj);
2516 obj->on_fini_list = true;
2521 #define FPTR_TARGET(f) ((Elf_Addr) (f))
2525 free_needed_filtees(Needed_Entry *n, RtldLockState *lockstate)
2527 Needed_Entry *needed, *needed1;
2529 for (needed = n; needed != NULL; needed = needed->next) {
2530 if (needed->obj != NULL) {
2531 dlclose_locked(needed->obj, lockstate);
2535 for (needed = n; needed != NULL; needed = needed1) {
2536 needed1 = needed->next;
2542 unload_filtees(Obj_Entry *obj, RtldLockState *lockstate)
2545 free_needed_filtees(obj->needed_filtees, lockstate);
2546 obj->needed_filtees = NULL;
2547 free_needed_filtees(obj->needed_aux_filtees, lockstate);
2548 obj->needed_aux_filtees = NULL;
2549 obj->filtees_loaded = false;
2553 load_filtee1(Obj_Entry *obj, Needed_Entry *needed, int flags,
2554 RtldLockState *lockstate)
2557 for (; needed != NULL; needed = needed->next) {
2558 needed->obj = dlopen_object(obj->strtab + needed->name, -1, obj,
2559 flags, ((ld_loadfltr || obj->z_loadfltr) ? RTLD_NOW : RTLD_LAZY) |
2560 RTLD_LOCAL, lockstate);
2565 load_filtees(Obj_Entry *obj, int flags, RtldLockState *lockstate)
2568 lock_restart_for_upgrade(lockstate);
2569 if (!obj->filtees_loaded) {
2570 load_filtee1(obj, obj->needed_filtees, flags, lockstate);
2571 load_filtee1(obj, obj->needed_aux_filtees, flags, lockstate);
2572 obj->filtees_loaded = true;
2577 process_needed(Obj_Entry *obj, Needed_Entry *needed, int flags)
2581 for (; needed != NULL; needed = needed->next) {
2582 obj1 = needed->obj = load_object(obj->strtab + needed->name, -1, obj,
2583 flags & ~RTLD_LO_NOLOAD);
2584 if (obj1 == NULL && !ld_tracing && (flags & RTLD_LO_FILTEES) == 0)
2591 * Given a shared object, traverse its list of needed objects, and load
2592 * each of them. Returns 0 on success. Generates an error message and
2593 * returns -1 on failure.
2596 load_needed_objects(Obj_Entry *first, int flags)
2600 for (obj = first; obj != NULL; obj = TAILQ_NEXT(obj, next)) {
2603 if (process_needed(obj, obj->needed, flags) == -1)
2610 load_preload_objects(const char *penv, bool isfd)
2615 char savech, *p, *psave;
2617 static const char delim[] = " \t:;";
2622 p = psave = xstrdup(penv);
2623 p += strspn(p, delim);
2624 while (*p != '\0') {
2625 len = strcspn(p, delim);
2631 fd = parse_integer(p);
2641 obj = load_object(name, fd, NULL, 0);
2644 return (-1); /* XXX - cleanup */
2646 obj->z_interpose = true;
2649 p += strspn(p, delim);
2651 LD_UTRACE(UTRACE_PRELOAD_FINISHED, NULL, NULL, 0, 0, NULL);
2658 printable_path(const char *path)
2661 return (path == NULL ? "<unknown>" : path);
2665 * Load a shared object into memory, if it is not already loaded. The
2666 * object may be specified by name or by user-supplied file descriptor
2667 * fd_u. In the later case, the fd_u descriptor is not closed, but its
2670 * Returns a pointer to the Obj_Entry for the object. Returns NULL
2674 load_object(const char *name, int fd_u, const Obj_Entry *refobj, int flags)
2683 TAILQ_FOREACH(obj, &obj_list, next) {
2684 if (obj->marker || obj->doomed)
2686 if (object_match_name(obj, name))
2690 path = find_library(name, refobj, &fd);
2698 * search_library_pathfds() opens a fresh file descriptor for the
2699 * library, so there is no need to dup().
2701 } else if (fd_u == -1) {
2703 * If we didn't find a match by pathname, or the name is not
2704 * supplied, open the file and check again by device and inode.
2705 * This avoids false mismatches caused by multiple links or ".."
2708 * To avoid a race, we open the file and use fstat() rather than
2711 if ((fd = open(path, O_RDONLY | O_CLOEXEC | O_VERIFY)) == -1) {
2712 _rtld_error("Cannot open \"%s\"", path);
2717 fd = fcntl(fd_u, F_DUPFD_CLOEXEC, 0);
2719 _rtld_error("Cannot dup fd");
2724 if (fstat(fd, &sb) == -1) {
2725 _rtld_error("Cannot fstat \"%s\"", printable_path(path));
2730 TAILQ_FOREACH(obj, &obj_list, next) {
2731 if (obj->marker || obj->doomed)
2733 if (obj->ino == sb.st_ino && obj->dev == sb.st_dev)
2736 if (obj != NULL && name != NULL) {
2737 object_add_name(obj, name);
2742 if (flags & RTLD_LO_NOLOAD) {
2748 /* First use of this object, so we must map it in */
2749 obj = do_load_object(fd, name, path, &sb, flags);
2758 do_load_object(int fd, const char *name, char *path, struct stat *sbp,
2765 * First, make sure that environment variables haven't been
2766 * used to circumvent the noexec flag on a filesystem.
2767 * We ignore fstatfs(2) failures, since fd might reference
2768 * not a file, e.g. shmfd.
2770 if (dangerous_ld_env && fstatfs(fd, &fs) == 0 &&
2771 (fs.f_flags & MNT_NOEXEC) != 0) {
2772 _rtld_error("Cannot execute objects on %s", fs.f_mntonname);
2776 dbg("loading \"%s\"", printable_path(path));
2777 obj = map_object(fd, printable_path(path), sbp);
2782 * If DT_SONAME is present in the object, digest_dynamic2 already
2783 * added it to the object names.
2786 object_add_name(obj, name);
2788 if (!digest_dynamic(obj, 0))
2790 dbg("%s valid_hash_sysv %d valid_hash_gnu %d dynsymcount %d", obj->path,
2791 obj->valid_hash_sysv, obj->valid_hash_gnu, obj->dynsymcount);
2792 if (obj->z_pie && (flags & RTLD_LO_TRACE) == 0) {
2793 dbg("refusing to load PIE executable \"%s\"", obj->path);
2794 _rtld_error("Cannot load PIE binary %s as DSO", obj->path);
2797 if (obj->z_noopen && (flags & (RTLD_LO_DLOPEN | RTLD_LO_TRACE)) ==
2799 dbg("refusing to load non-loadable \"%s\"", obj->path);
2800 _rtld_error("Cannot dlopen non-loadable %s", obj->path);
2804 obj->dlopened = (flags & RTLD_LO_DLOPEN) != 0;
2805 TAILQ_INSERT_TAIL(&obj_list, obj, next);
2808 linkmap_add(obj); /* for GDB & dlinfo() */
2809 max_stack_flags |= obj->stack_flags;
2811 dbg(" %p .. %p: %s", obj->mapbase,
2812 obj->mapbase + obj->mapsize - 1, obj->path);
2814 dbg(" WARNING: %s has impure text", obj->path);
2815 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, obj->mapsize, 0,
2821 munmap(obj->mapbase, obj->mapsize);
2827 load_kpreload(const void *addr)
2830 const Elf_Ehdr *ehdr;
2831 const Elf_Phdr *phdr, *phlimit, *phdyn, *seg0, *segn;
2832 static const char kname[] = "[vdso]";
2835 if (!check_elf_headers(ehdr, "kpreload"))
2838 phdr = (const Elf_Phdr *)((const char *)addr + ehdr->e_phoff);
2840 obj->phsize = ehdr->e_phnum * sizeof(*phdr);
2841 phlimit = phdr + ehdr->e_phnum;
2844 for (; phdr < phlimit; phdr++) {
2845 switch (phdr->p_type) {
2850 /* Absense of PT_GNU_STACK implies stack_flags == 0. */
2851 obj->stack_flags = phdr->p_flags;
2854 if (seg0 == NULL || seg0->p_vaddr > phdr->p_vaddr)
2856 if (segn == NULL || segn->p_vaddr + segn->p_memsz <
2857 phdr->p_vaddr + phdr->p_memsz)
2863 obj->mapbase = __DECONST(caddr_t, addr);
2864 obj->mapsize = segn->p_vaddr + segn->p_memsz - (Elf_Addr)addr;
2866 obj->relocbase = obj->mapbase;
2868 object_add_name(obj, kname);
2869 obj->path = xstrdup(kname);
2870 obj->dynamic = (const Elf_Dyn *)(obj->relocbase + phdyn->p_vaddr);
2872 if (!digest_dynamic(obj, 0)) {
2878 * We assume that kernel-preloaded object does not need
2879 * relocation. It is currently written into read-only page,
2880 * handling relocations would mean we need to allocate at
2881 * least one additional page per AS.
2883 dbg("%s mapbase %p phdrs %p PT_LOAD phdr %p vaddr %p dynamic %p",
2884 obj->path, obj->mapbase, obj->phdr, seg0,
2885 obj->relocbase + seg0->p_vaddr, obj->dynamic);
2887 TAILQ_INSERT_TAIL(&obj_list, obj, next);
2890 linkmap_add(obj); /* for GDB & dlinfo() */
2891 max_stack_flags |= obj->stack_flags;
2893 LD_UTRACE(UTRACE_LOAD_OBJECT, obj, obj->mapbase, 0, 0, obj->path);
2898 obj_from_addr(const void *addr)
2902 TAILQ_FOREACH(obj, &obj_list, next) {
2905 if (addr < (void *) obj->mapbase)
2907 if (addr < (void *)(obj->mapbase + obj->mapsize))
2916 Elf_Addr *preinit_addr;
2919 preinit_addr = (Elf_Addr *)obj_main->preinit_array;
2920 if (preinit_addr == NULL)
2923 for (index = 0; index < obj_main->preinit_array_num; index++) {
2924 if (preinit_addr[index] != 0 && preinit_addr[index] != 1) {
2925 dbg("calling preinit function for %s at %p", obj_main->path,
2926 (void *)preinit_addr[index]);
2927 LD_UTRACE(UTRACE_INIT_CALL, obj_main, (void *)preinit_addr[index],
2928 0, 0, obj_main->path);
2929 call_init_pointer(obj_main, preinit_addr[index]);
2935 * Call the finalization functions for each of the objects in "list"
2936 * belonging to the DAG of "root" and referenced once. If NULL "root"
2937 * is specified, every finalization function will be called regardless
2938 * of the reference count and the list elements won't be freed. All of
2939 * the objects are expected to have non-NULL fini functions.
2942 objlist_call_fini(Objlist *list, Obj_Entry *root, RtldLockState *lockstate)
2945 struct dlerror_save *saved_msg;
2946 Elf_Addr *fini_addr;
2949 assert(root == NULL || root->refcount == 1);
2952 root->doomed = true;
2955 * Preserve the current error message since a fini function might
2956 * call into the dynamic linker and overwrite it.
2958 saved_msg = errmsg_save();
2960 STAILQ_FOREACH(elm, list, link) {
2961 if (root != NULL && (elm->obj->refcount != 1 ||
2962 objlist_find(&root->dagmembers, elm->obj) == NULL))
2964 /* Remove object from fini list to prevent recursive invocation. */
2965 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
2966 /* Ensure that new references cannot be acquired. */
2967 elm->obj->doomed = true;
2969 hold_object(elm->obj);
2970 lock_release(rtld_bind_lock, lockstate);
2972 * It is legal to have both DT_FINI and DT_FINI_ARRAY defined.
2973 * When this happens, DT_FINI_ARRAY is processed first.
2975 fini_addr = (Elf_Addr *)elm->obj->fini_array;
2976 if (fini_addr != NULL && elm->obj->fini_array_num > 0) {
2977 for (index = elm->obj->fini_array_num - 1; index >= 0;
2979 if (fini_addr[index] != 0 && fini_addr[index] != 1) {
2980 dbg("calling fini function for %s at %p",
2981 elm->obj->path, (void *)fini_addr[index]);
2982 LD_UTRACE(UTRACE_FINI_CALL, elm->obj,
2983 (void *)fini_addr[index], 0, 0, elm->obj->path);
2984 call_initfini_pointer(elm->obj, fini_addr[index]);
2988 if (elm->obj->fini != (Elf_Addr)NULL) {
2989 dbg("calling fini function for %s at %p", elm->obj->path,
2990 (void *)elm->obj->fini);
2991 LD_UTRACE(UTRACE_FINI_CALL, elm->obj, (void *)elm->obj->fini,
2992 0, 0, elm->obj->path);
2993 call_initfini_pointer(elm->obj, elm->obj->fini);
2995 wlock_acquire(rtld_bind_lock, lockstate);
2996 unhold_object(elm->obj);
2997 /* No need to free anything if process is going down. */
3001 * We must restart the list traversal after every fini call
3002 * because a dlclose() call from the fini function or from
3003 * another thread might have modified the reference counts.
3007 } while (elm != NULL);
3008 errmsg_restore(saved_msg);
3012 * Call the initialization functions for each of the objects in
3013 * "list". All of the objects are expected to have non-NULL init
3017 objlist_call_init(Objlist *list, RtldLockState *lockstate)
3021 struct dlerror_save *saved_msg;
3022 Elf_Addr *init_addr;
3023 void (*reg)(void (*)(void));
3027 * Clean init_scanned flag so that objects can be rechecked and
3028 * possibly initialized earlier if any of vectors called below
3029 * cause the change by using dlopen.
3031 TAILQ_FOREACH(obj, &obj_list, next) {
3034 obj->init_scanned = false;
3038 * Preserve the current error message since an init function might
3039 * call into the dynamic linker and overwrite it.
3041 saved_msg = errmsg_save();
3042 STAILQ_FOREACH(elm, list, link) {
3043 if (elm->obj->init_done) /* Initialized early. */
3046 * Race: other thread might try to use this object before current
3047 * one completes the initialization. Not much can be done here
3048 * without better locking.
3050 elm->obj->init_done = true;
3051 hold_object(elm->obj);
3053 if (elm->obj == obj_main && obj_main->crt_no_init) {
3054 reg = (void (*)(void (*)(void)))get_program_var_addr(
3055 "__libc_atexit", lockstate);
3057 lock_release(rtld_bind_lock, lockstate);
3060 rtld_exit_ptr = rtld_nop_exit;
3064 * It is legal to have both DT_INIT and DT_INIT_ARRAY defined.
3065 * When this happens, DT_INIT is processed first.
3067 if (elm->obj->init != (Elf_Addr)NULL) {
3068 dbg("calling init function for %s at %p", elm->obj->path,
3069 (void *)elm->obj->init);
3070 LD_UTRACE(UTRACE_INIT_CALL, elm->obj, (void *)elm->obj->init,
3071 0, 0, elm->obj->path);
3072 call_init_pointer(elm->obj, elm->obj->init);
3074 init_addr = (Elf_Addr *)elm->obj->init_array;
3075 if (init_addr != NULL) {
3076 for (index = 0; index < elm->obj->init_array_num; index++) {
3077 if (init_addr[index] != 0 && init_addr[index] != 1) {
3078 dbg("calling init function for %s at %p", elm->obj->path,
3079 (void *)init_addr[index]);
3080 LD_UTRACE(UTRACE_INIT_CALL, elm->obj,
3081 (void *)init_addr[index], 0, 0, elm->obj->path);
3082 call_init_pointer(elm->obj, init_addr[index]);
3086 wlock_acquire(rtld_bind_lock, lockstate);
3087 unhold_object(elm->obj);
3089 errmsg_restore(saved_msg);
3093 objlist_clear(Objlist *list)
3097 while (!STAILQ_EMPTY(list)) {
3098 elm = STAILQ_FIRST(list);
3099 STAILQ_REMOVE_HEAD(list, link);
3104 static Objlist_Entry *
3105 objlist_find(Objlist *list, const Obj_Entry *obj)
3109 STAILQ_FOREACH(elm, list, link)
3110 if (elm->obj == obj)
3116 objlist_init(Objlist *list)
3122 objlist_push_head(Objlist *list, Obj_Entry *obj)
3126 elm = NEW(Objlist_Entry);
3128 STAILQ_INSERT_HEAD(list, elm, link);
3132 objlist_push_tail(Objlist *list, Obj_Entry *obj)
3136 elm = NEW(Objlist_Entry);
3138 STAILQ_INSERT_TAIL(list, elm, link);
3142 objlist_put_after(Objlist *list, Obj_Entry *listobj, Obj_Entry *obj)
3144 Objlist_Entry *elm, *listelm;
3146 STAILQ_FOREACH(listelm, list, link) {
3147 if (listelm->obj == listobj)
3150 elm = NEW(Objlist_Entry);
3152 if (listelm != NULL)
3153 STAILQ_INSERT_AFTER(list, listelm, elm, link);
3155 STAILQ_INSERT_TAIL(list, elm, link);
3159 objlist_remove(Objlist *list, Obj_Entry *obj)
3163 if ((elm = objlist_find(list, obj)) != NULL) {
3164 STAILQ_REMOVE(list, elm, Struct_Objlist_Entry, link);
3170 * Relocate dag rooted in the specified object.
3171 * Returns 0 on success, or -1 on failure.
3175 relocate_object_dag(Obj_Entry *root, bool bind_now, Obj_Entry *rtldobj,
3176 int flags, RtldLockState *lockstate)
3182 STAILQ_FOREACH(elm, &root->dagmembers, link) {
3183 error = relocate_object(elm->obj, bind_now, rtldobj, flags,
3192 * Prepare for, or clean after, relocating an object marked with
3193 * DT_TEXTREL or DF_TEXTREL. Before relocating, all read-only
3194 * segments are remapped read-write. After relocations are done, the
3195 * segment's permissions are returned back to the modes specified in
3196 * the phdrs. If any relocation happened, or always for wired
3197 * program, COW is triggered.
3200 reloc_textrel_prot(Obj_Entry *obj, bool before)
3207 for (l = obj->phsize / sizeof(*ph), ph = obj->phdr; l > 0;
3209 if (ph->p_type != PT_LOAD || (ph->p_flags & PF_W) != 0)
3211 base = obj->relocbase + trunc_page(ph->p_vaddr);
3212 sz = round_page(ph->p_vaddr + ph->p_filesz) -
3213 trunc_page(ph->p_vaddr);
3214 prot = before ? (PROT_READ | PROT_WRITE) :
3215 convert_prot(ph->p_flags);
3216 if (mprotect(base, sz, prot) == -1) {
3217 _rtld_error("%s: Cannot write-%sable text segment: %s",
3218 obj->path, before ? "en" : "dis",
3219 rtld_strerror(errno));
3226 /* Process RELR relative relocations. */
3228 reloc_relr(Obj_Entry *obj)
3230 const Elf_Relr *relr, *relrlim;
3233 relrlim = (const Elf_Relr *)((const char *)obj->relr + obj->relrsize);
3234 for (relr = obj->relr; relr < relrlim; relr++) {
3235 Elf_Relr entry = *relr;
3237 if ((entry & 1) == 0) {
3238 where = (Elf_Addr *)(obj->relocbase + entry);
3239 *where++ += (Elf_Addr)obj->relocbase;
3241 for (long i = 0; (entry >>= 1) != 0; i++)
3242 if ((entry & 1) != 0)
3243 where[i] += (Elf_Addr)obj->relocbase;
3244 where += CHAR_BIT * sizeof(Elf_Relr) - 1;
3250 * Relocate single object.
3251 * Returns 0 on success, or -1 on failure.
3254 relocate_object(Obj_Entry *obj, bool bind_now, Obj_Entry *rtldobj,
3255 int flags, RtldLockState *lockstate)
3260 obj->relocated = true;
3262 dbg("relocating \"%s\"", obj->path);
3264 if (obj->symtab == NULL || obj->strtab == NULL ||
3265 !(obj->valid_hash_sysv || obj->valid_hash_gnu))
3266 dbg("object %s has no run-time symbol table", obj->path);
3268 /* There are relocations to the write-protected text segment. */
3269 if (obj->textrel && reloc_textrel_prot(obj, true) != 0)
3272 /* Process the non-PLT non-IFUNC relocations. */
3273 if (reloc_non_plt(obj, rtldobj, flags, lockstate))
3277 /* Re-protected the text segment. */
3278 if (obj->textrel && reloc_textrel_prot(obj, false) != 0)
3281 /* Set the special PLT or GOT entries. */
3284 /* Process the PLT relocations. */
3285 if (reloc_plt(obj, flags, lockstate) == -1)
3287 /* Relocate the jump slots if we are doing immediate binding. */
3288 if ((obj->bind_now || bind_now) && reloc_jmpslots(obj, flags,
3292 if (!obj->mainprog && obj_enforce_relro(obj) == -1)
3296 * Set up the magic number and version in the Obj_Entry. These
3297 * were checked in the crt1.o from the original ElfKit, so we
3298 * set them for backward compatibility.
3300 obj->magic = RTLD_MAGIC;
3301 obj->version = RTLD_VERSION;
3307 * Relocate newly-loaded shared objects. The argument is a pointer to
3308 * the Obj_Entry for the first such object. All objects from the first
3309 * to the end of the list of objects are relocated. Returns 0 on success,
3313 relocate_objects(Obj_Entry *first, bool bind_now, Obj_Entry *rtldobj,
3314 int flags, RtldLockState *lockstate)
3319 for (error = 0, obj = first; obj != NULL;
3320 obj = TAILQ_NEXT(obj, next)) {
3323 error = relocate_object(obj, bind_now, rtldobj, flags,
3332 * The handling of R_MACHINE_IRELATIVE relocations and jumpslots
3333 * referencing STT_GNU_IFUNC symbols is postponed till the other
3334 * relocations are done. The indirect functions specified as
3335 * ifunc are allowed to call other symbols, so we need to have
3336 * objects relocated before asking for resolution from indirects.
3338 * The R_MACHINE_IRELATIVE slots are resolved in greedy fashion,
3339 * instead of the usual lazy handling of PLT slots. It is
3340 * consistent with how GNU does it.
3343 resolve_object_ifunc(Obj_Entry *obj, bool bind_now, int flags,
3344 RtldLockState *lockstate)
3347 if (obj->ifuncs_resolved)
3349 obj->ifuncs_resolved = true;
3350 if (!obj->irelative && !obj->irelative_nonplt &&
3351 !((obj->bind_now || bind_now) && obj->gnu_ifunc) &&
3352 !obj->non_plt_gnu_ifunc)
3354 if (obj_disable_relro(obj) == -1 ||
3355 (obj->irelative && reloc_iresolve(obj, lockstate) == -1) ||
3356 (obj->irelative_nonplt && reloc_iresolve_nonplt(obj,
3357 lockstate) == -1) ||
3358 ((obj->bind_now || bind_now) && obj->gnu_ifunc &&
3359 reloc_gnu_ifunc(obj, flags, lockstate) == -1) ||
3360 (obj->non_plt_gnu_ifunc && reloc_non_plt(obj, &obj_rtld,
3361 flags | SYMLOOK_IFUNC, lockstate) == -1) ||
3362 obj_enforce_relro(obj) == -1)
3368 initlist_objects_ifunc(Objlist *list, bool bind_now, int flags,
3369 RtldLockState *lockstate)
3374 STAILQ_FOREACH(elm, list, link) {
3378 if (resolve_object_ifunc(obj, bind_now, flags,
3386 * Cleanup procedure. It will be called (by the atexit mechanism) just
3387 * before the process exits.
3392 RtldLockState lockstate;
3394 wlock_acquire(rtld_bind_lock, &lockstate);
3396 objlist_call_fini(&list_fini, NULL, &lockstate);
3397 /* No need to remove the items from the list, since we are exiting. */
3398 if (!libmap_disable)
3400 lock_release(rtld_bind_lock, &lockstate);
3409 * Iterate over a search path, translate each element, and invoke the
3410 * callback on the result.
3413 path_enumerate(const char *path, path_enum_proc callback,
3414 const char *refobj_path, void *arg)
3420 path += strspn(path, ":;");
3421 while (*path != '\0') {
3425 len = strcspn(path, ":;");
3426 trans = lm_findn(refobj_path, path, len);
3428 res = callback(trans, strlen(trans), arg);
3430 res = callback(path, len, arg);
3436 path += strspn(path, ":;");
3442 struct try_library_args {
3451 try_library_path(const char *dir, size_t dirlen, void *param)
3453 struct try_library_args *arg;
3457 if (*dir == '/' || trust) {
3460 if (dirlen + 1 + arg->namelen + 1 > arg->buflen)
3463 pathname = arg->buffer;
3464 strncpy(pathname, dir, dirlen);
3465 pathname[dirlen] = '/';
3466 strcpy(pathname + dirlen + 1, arg->name);
3468 dbg(" Trying \"%s\"", pathname);
3469 fd = open(pathname, O_RDONLY | O_CLOEXEC | O_VERIFY);
3471 dbg(" Opened \"%s\", fd %d", pathname, fd);
3472 pathname = xmalloc(dirlen + 1 + arg->namelen + 1);
3473 strcpy(pathname, arg->buffer);
3477 dbg(" Failed to open \"%s\": %s",
3478 pathname, rtld_strerror(errno));
3485 search_library_path(const char *name, const char *path,
3486 const char *refobj_path, int *fdp)
3489 struct try_library_args arg;
3495 arg.namelen = strlen(name);
3496 arg.buffer = xmalloc(PATH_MAX);
3497 arg.buflen = PATH_MAX;
3500 p = path_enumerate(path, try_library_path, refobj_path, &arg);
3510 * Finds the library with the given name using the directory descriptors
3511 * listed in the LD_LIBRARY_PATH_FDS environment variable.
3513 * Returns a freshly-opened close-on-exec file descriptor for the library,
3514 * or -1 if the library cannot be found.
3517 search_library_pathfds(const char *name, const char *path, int *fdp)
3519 char *envcopy, *fdstr, *found, *last_token;
3523 dbg("%s('%s', '%s', fdp)", __func__, name, path);
3525 /* Don't load from user-specified libdirs into setuid binaries. */
3529 /* We can't do anything if LD_LIBRARY_PATH_FDS isn't set. */
3533 /* LD_LIBRARY_PATH_FDS only works with relative paths. */
3534 if (name[0] == '/') {
3535 dbg("Absolute path (%s) passed to %s", name, __func__);
3540 * Use strtok_r() to walk the FD:FD:FD list. This requires a local
3541 * copy of the path, as strtok_r rewrites separator tokens
3545 envcopy = xstrdup(path);
3546 for (fdstr = strtok_r(envcopy, ":", &last_token); fdstr != NULL;
3547 fdstr = strtok_r(NULL, ":", &last_token)) {
3548 dirfd = parse_integer(fdstr);
3550 _rtld_error("failed to parse directory FD: '%s'",
3554 fd = __sys_openat(dirfd, name, O_RDONLY | O_CLOEXEC | O_VERIFY);
3557 len = strlen(fdstr) + strlen(name) + 3;
3558 found = xmalloc(len);
3559 if (rtld_snprintf(found, len, "#%d/%s", dirfd, name) < 0) {
3560 _rtld_error("error generating '%d/%s'",
3564 dbg("open('%s') => %d", found, fd);
3575 dlclose(void *handle)
3577 RtldLockState lockstate;
3580 wlock_acquire(rtld_bind_lock, &lockstate);
3581 error = dlclose_locked(handle, &lockstate);
3582 lock_release(rtld_bind_lock, &lockstate);
3587 dlclose_locked(void *handle, RtldLockState *lockstate)
3591 root = dlcheck(handle);
3594 LD_UTRACE(UTRACE_DLCLOSE_START, handle, NULL, 0, root->dl_refcount,
3597 /* Unreference the object and its dependencies. */
3598 root->dl_refcount--;
3600 if (root->refcount == 1) {
3602 * The object will be no longer referenced, so we must unload it.
3603 * First, call the fini functions.
3605 objlist_call_fini(&list_fini, root, lockstate);
3609 /* Finish cleaning up the newly-unreferenced objects. */
3610 GDB_STATE(RT_DELETE,&root->linkmap);
3611 unload_object(root, lockstate);
3612 GDB_STATE(RT_CONSISTENT,NULL);
3616 LD_UTRACE(UTRACE_DLCLOSE_STOP, handle, NULL, 0, 0, NULL);
3623 if (*(lockinfo.dlerror_seen()) != 0)
3625 *lockinfo.dlerror_seen() = 1;
3626 return (lockinfo.dlerror_loc());
3630 * This function is deprecated and has no effect.
3633 dllockinit(void *context,
3634 void *(*_lock_create)(void *context) __unused,
3635 void (*_rlock_acquire)(void *lock) __unused,
3636 void (*_wlock_acquire)(void *lock) __unused,
3637 void (*_lock_release)(void *lock) __unused,
3638 void (*_lock_destroy)(void *lock) __unused,
3639 void (*context_destroy)(void *context))
3641 static void *cur_context;
3642 static void (*cur_context_destroy)(void *);
3644 /* Just destroy the context from the previous call, if necessary. */
3645 if (cur_context_destroy != NULL)
3646 cur_context_destroy(cur_context);
3647 cur_context = context;
3648 cur_context_destroy = context_destroy;
3652 dlopen(const char *name, int mode)
3655 return (rtld_dlopen(name, -1, mode));
3659 fdlopen(int fd, int mode)
3662 return (rtld_dlopen(NULL, fd, mode));
3666 rtld_dlopen(const char *name, int fd, int mode)
3668 RtldLockState lockstate;
3671 LD_UTRACE(UTRACE_DLOPEN_START, NULL, NULL, 0, mode, name);
3672 ld_tracing = (mode & RTLD_TRACE) == 0 ? NULL : "1";
3673 if (ld_tracing != NULL) {
3674 rlock_acquire(rtld_bind_lock, &lockstate);
3675 if (sigsetjmp(lockstate.env, 0) != 0)
3676 lock_upgrade(rtld_bind_lock, &lockstate);
3677 environ = __DECONST(char **, *get_program_var_addr("environ", &lockstate));
3678 lock_release(rtld_bind_lock, &lockstate);
3680 lo_flags = RTLD_LO_DLOPEN;
3681 if (mode & RTLD_NODELETE)
3682 lo_flags |= RTLD_LO_NODELETE;
3683 if (mode & RTLD_NOLOAD)
3684 lo_flags |= RTLD_LO_NOLOAD;
3685 if (mode & RTLD_DEEPBIND)
3686 lo_flags |= RTLD_LO_DEEPBIND;
3687 if (ld_tracing != NULL)
3688 lo_flags |= RTLD_LO_TRACE | RTLD_LO_IGNSTLS;
3690 return (dlopen_object(name, fd, obj_main, lo_flags,
3691 mode & (RTLD_MODEMASK | RTLD_GLOBAL), NULL));
3695 dlopen_cleanup(Obj_Entry *obj, RtldLockState *lockstate)
3700 if (obj->refcount == 0)
3701 unload_object(obj, lockstate);
3705 dlopen_object(const char *name, int fd, Obj_Entry *refobj, int lo_flags,
3706 int mode, RtldLockState *lockstate)
3708 Obj_Entry *old_obj_tail;
3711 RtldLockState mlockstate;
3714 dbg("dlopen_object name \"%s\" fd %d refobj \"%s\" lo_flags %#x mode %#x",
3715 name != NULL ? name : "<null>", fd, refobj == NULL ? "<null>" :
3716 refobj->path, lo_flags, mode);
3717 objlist_init(&initlist);
3719 if (lockstate == NULL && !(lo_flags & RTLD_LO_EARLY)) {
3720 wlock_acquire(rtld_bind_lock, &mlockstate);
3721 lockstate = &mlockstate;
3723 GDB_STATE(RT_ADD,NULL);
3725 old_obj_tail = globallist_curr(TAILQ_LAST(&obj_list, obj_entry_q));
3727 if (name == NULL && fd == -1) {
3731 obj = load_object(name, fd, refobj, lo_flags);
3736 if (mode & RTLD_GLOBAL && objlist_find(&list_global, obj) == NULL)
3737 objlist_push_tail(&list_global, obj);
3738 if (globallist_next(old_obj_tail) != NULL) {
3739 /* We loaded something new. */
3740 assert(globallist_next(old_obj_tail) == obj);
3741 if ((lo_flags & RTLD_LO_DEEPBIND) != 0)
3742 obj->symbolic = true;
3744 if ((lo_flags & (RTLD_LO_EARLY | RTLD_LO_IGNSTLS)) == 0 &&
3745 obj->static_tls && !allocate_tls_offset(obj)) {
3746 _rtld_error("%s: No space available "
3747 "for static Thread Local Storage", obj->path);
3751 result = load_needed_objects(obj, lo_flags & (RTLD_LO_DLOPEN |
3752 RTLD_LO_EARLY | RTLD_LO_IGNSTLS | RTLD_LO_TRACE));
3756 result = rtld_verify_versions(&obj->dagmembers);
3757 if (result != -1 && ld_tracing)
3759 if (result == -1 || relocate_object_dag(obj,
3760 (mode & RTLD_MODEMASK) == RTLD_NOW, &obj_rtld,
3761 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
3763 dlopen_cleanup(obj, lockstate);
3765 } else if (lo_flags & RTLD_LO_EARLY) {
3767 * Do not call the init functions for early loaded
3768 * filtees. The image is still not initialized enough
3771 * Our object is found by the global object list and
3772 * will be ordered among all init calls done right
3773 * before transferring control to main.
3776 /* Make list of init functions to call. */
3777 initlist_add_objects(obj, obj, &initlist);
3780 * Process all no_delete or global objects here, given
3781 * them own DAGs to prevent their dependencies from being
3782 * unloaded. This has to be done after we have loaded all
3783 * of the dependencies, so that we do not miss any.
3789 * Bump the reference counts for objects on this DAG. If
3790 * this is the first dlopen() call for the object that was
3791 * already loaded as a dependency, initialize the dag
3797 if ((lo_flags & RTLD_LO_TRACE) != 0)
3800 if (obj != NULL && ((lo_flags & RTLD_LO_NODELETE) != 0 ||
3801 obj->z_nodelete) && !obj->ref_nodel) {
3802 dbg("obj %s nodelete", obj->path);
3804 obj->z_nodelete = obj->ref_nodel = true;
3808 LD_UTRACE(UTRACE_DLOPEN_STOP, obj, NULL, 0, obj ? obj->dl_refcount : 0,
3810 GDB_STATE(RT_CONSISTENT,obj ? &obj->linkmap : NULL);
3812 if ((lo_flags & RTLD_LO_EARLY) == 0) {
3813 map_stacks_exec(lockstate);
3815 distribute_static_tls(&initlist, lockstate);
3818 if (initlist_objects_ifunc(&initlist, (mode & RTLD_MODEMASK) == RTLD_NOW,
3819 (lo_flags & RTLD_LO_EARLY) ? SYMLOOK_EARLY : 0,
3821 objlist_clear(&initlist);
3822 dlopen_cleanup(obj, lockstate);
3823 if (lockstate == &mlockstate)
3824 lock_release(rtld_bind_lock, lockstate);
3828 if (!(lo_flags & RTLD_LO_EARLY)) {
3829 /* Call the init functions. */
3830 objlist_call_init(&initlist, lockstate);
3832 objlist_clear(&initlist);
3833 if (lockstate == &mlockstate)
3834 lock_release(rtld_bind_lock, lockstate);
3837 trace_loaded_objects(obj, false);
3838 if (lockstate == &mlockstate)
3839 lock_release(rtld_bind_lock, lockstate);
3844 do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
3848 const Obj_Entry *obj, *defobj;
3851 RtldLockState lockstate;
3858 symlook_init(&req, name);
3860 req.flags = flags | SYMLOOK_IN_PLT;
3861 req.lockstate = &lockstate;
3863 LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name);
3864 rlock_acquire(rtld_bind_lock, &lockstate);
3865 if (sigsetjmp(lockstate.env, 0) != 0)
3866 lock_upgrade(rtld_bind_lock, &lockstate);
3867 if (handle == NULL || handle == RTLD_NEXT ||
3868 handle == RTLD_DEFAULT || handle == RTLD_SELF) {
3870 if ((obj = obj_from_addr(retaddr)) == NULL) {
3871 _rtld_error("Cannot determine caller's shared object");
3872 lock_release(rtld_bind_lock, &lockstate);
3873 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3876 if (handle == NULL) { /* Just the caller's shared object. */
3877 res = symlook_obj(&req, obj);
3880 defobj = req.defobj_out;
3882 } else if (handle == RTLD_NEXT || /* Objects after caller's */
3883 handle == RTLD_SELF) { /* ... caller included */
3884 if (handle == RTLD_NEXT)
3885 obj = globallist_next(obj);
3886 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) {
3889 res = symlook_obj(&req, obj);
3891 if (def == NULL || (ld_dynamic_weak &&
3892 ELF_ST_BIND(req.sym_out->st_info) != STB_WEAK)) {
3894 defobj = req.defobj_out;
3895 if (!ld_dynamic_weak ||
3896 ELF_ST_BIND(def->st_info) != STB_WEAK)
3902 * Search the dynamic linker itself, and possibly resolve the
3903 * symbol from there. This is how the application links to
3904 * dynamic linker services such as dlopen.
3905 * Note that we ignore ld_dynamic_weak == false case,
3906 * always overriding weak symbols by rtld definitions.
3908 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3909 res = symlook_obj(&req, &obj_rtld);
3912 defobj = req.defobj_out;
3916 assert(handle == RTLD_DEFAULT);
3917 res = symlook_default(&req, obj);
3919 defobj = req.defobj_out;
3924 if ((obj = dlcheck(handle)) == NULL) {
3925 lock_release(rtld_bind_lock, &lockstate);
3926 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3930 donelist_init(&donelist);
3931 if (obj->mainprog) {
3932 /* Handle obtained by dlopen(NULL, ...) implies global scope. */
3933 res = symlook_global(&req, &donelist);
3936 defobj = req.defobj_out;
3939 * Search the dynamic linker itself, and possibly resolve the
3940 * symbol from there. This is how the application links to
3941 * dynamic linker services such as dlopen.
3943 if (def == NULL || ELF_ST_BIND(def->st_info) == STB_WEAK) {
3944 res = symlook_obj(&req, &obj_rtld);
3947 defobj = req.defobj_out;
3952 /* Search the whole DAG rooted at the given object. */
3953 res = symlook_list(&req, &obj->dagmembers, &donelist);
3956 defobj = req.defobj_out;
3962 lock_release(rtld_bind_lock, &lockstate);
3965 * The value required by the caller is derived from the value
3966 * of the symbol. this is simply the relocated value of the
3969 if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
3970 sym = make_function_pointer(def, defobj);
3971 else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
3972 sym = rtld_resolve_ifunc(defobj, def);
3973 else if (ELF_ST_TYPE(def->st_info) == STT_TLS) {
3974 ti.ti_module = defobj->tlsindex;
3975 ti.ti_offset = def->st_value;
3976 sym = __tls_get_addr(&ti);
3978 sym = defobj->relocbase + def->st_value;
3979 LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name);
3983 _rtld_error("Undefined symbol \"%s%s%s\"", name, ve != NULL ? "@" : "",
3984 ve != NULL ? ve->name : "");
3985 lock_release(rtld_bind_lock, &lockstate);
3986 LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
3991 dlsym(void *handle, const char *name)
3993 return (do_dlsym(handle, name, __builtin_return_address(0), NULL,
3998 dlfunc(void *handle, const char *name)
4005 rv.d = do_dlsym(handle, name, __builtin_return_address(0), NULL,
4011 dlvsym(void *handle, const char *name, const char *version)
4015 ventry.name = version;
4017 ventry.hash = elf_hash(version);
4019 return (do_dlsym(handle, name, __builtin_return_address(0), &ventry,
4024 _rtld_addr_phdr(const void *addr, struct dl_phdr_info *phdr_info)
4026 const Obj_Entry *obj;
4027 RtldLockState lockstate;
4029 rlock_acquire(rtld_bind_lock, &lockstate);
4030 obj = obj_from_addr(addr);
4032 _rtld_error("No shared object contains address");
4033 lock_release(rtld_bind_lock, &lockstate);
4036 rtld_fill_dl_phdr_info(obj, phdr_info);
4037 lock_release(rtld_bind_lock, &lockstate);
4042 dladdr(const void *addr, Dl_info *info)
4044 const Obj_Entry *obj;
4047 unsigned long symoffset;
4048 RtldLockState lockstate;
4050 rlock_acquire(rtld_bind_lock, &lockstate);
4051 obj = obj_from_addr(addr);
4053 _rtld_error("No shared object contains address");
4054 lock_release(rtld_bind_lock, &lockstate);
4057 info->dli_fname = obj->path;
4058 info->dli_fbase = obj->mapbase;
4059 info->dli_saddr = (void *)0;
4060 info->dli_sname = NULL;
4063 * Walk the symbol list looking for the symbol whose address is
4064 * closest to the address sent in.
4066 for (symoffset = 0; symoffset < obj->dynsymcount; symoffset++) {
4067 def = obj->symtab + symoffset;
4070 * For skip the symbol if st_shndx is either SHN_UNDEF or
4073 if (def->st_shndx == SHN_UNDEF || def->st_shndx == SHN_COMMON)
4077 * If the symbol is greater than the specified address, or if it
4078 * is further away from addr than the current nearest symbol,
4081 symbol_addr = obj->relocbase + def->st_value;
4082 if (symbol_addr > addr || symbol_addr < info->dli_saddr)
4085 /* Update our idea of the nearest symbol. */
4086 info->dli_sname = obj->strtab + def->st_name;
4087 info->dli_saddr = symbol_addr;
4090 if (info->dli_saddr == addr)
4093 lock_release(rtld_bind_lock, &lockstate);
4098 dlinfo(void *handle, int request, void *p)
4100 const Obj_Entry *obj;
4101 RtldLockState lockstate;
4104 rlock_acquire(rtld_bind_lock, &lockstate);
4106 if (handle == NULL || handle == RTLD_SELF) {
4109 retaddr = __builtin_return_address(0); /* __GNUC__ only */
4110 if ((obj = obj_from_addr(retaddr)) == NULL)
4111 _rtld_error("Cannot determine caller's shared object");
4113 obj = dlcheck(handle);
4116 lock_release(rtld_bind_lock, &lockstate);
4122 case RTLD_DI_LINKMAP:
4123 *((struct link_map const **)p) = &obj->linkmap;
4125 case RTLD_DI_ORIGIN:
4126 error = rtld_dirname(obj->path, p);
4129 case RTLD_DI_SERINFOSIZE:
4130 case RTLD_DI_SERINFO:
4131 error = do_search_info(obj, request, (struct dl_serinfo *)p);
4135 _rtld_error("Invalid request %d passed to dlinfo()", request);
4139 lock_release(rtld_bind_lock, &lockstate);
4145 rtld_fill_dl_phdr_info(const Obj_Entry *obj, struct dl_phdr_info *phdr_info)
4149 phdr_info->dlpi_addr = (Elf_Addr)obj->relocbase;
4150 phdr_info->dlpi_name = obj->path;
4151 phdr_info->dlpi_phdr = obj->phdr;
4152 phdr_info->dlpi_phnum = obj->phsize / sizeof(obj->phdr[0]);
4153 phdr_info->dlpi_tls_modid = obj->tlsindex;
4154 dtvp = &_tcb_get()->tcb_dtv;
4155 phdr_info->dlpi_tls_data = (char *)tls_get_addr_slow(dtvp,
4156 obj->tlsindex, 0, true) + TLS_DTV_OFFSET;
4157 phdr_info->dlpi_adds = obj_loads;
4158 phdr_info->dlpi_subs = obj_loads - obj_count;
4162 dl_iterate_phdr(__dl_iterate_hdr_callback callback, void *param)
4164 struct dl_phdr_info phdr_info;
4165 Obj_Entry *obj, marker;
4166 RtldLockState bind_lockstate, phdr_lockstate;
4169 init_marker(&marker);
4172 wlock_acquire(rtld_phdr_lock, &phdr_lockstate);
4173 wlock_acquire(rtld_bind_lock, &bind_lockstate);
4174 for (obj = globallist_curr(TAILQ_FIRST(&obj_list)); obj != NULL;) {
4175 TAILQ_INSERT_AFTER(&obj_list, obj, &marker, next);
4176 rtld_fill_dl_phdr_info(obj, &phdr_info);
4178 lock_release(rtld_bind_lock, &bind_lockstate);
4180 error = callback(&phdr_info, sizeof phdr_info, param);
4182 wlock_acquire(rtld_bind_lock, &bind_lockstate);
4184 obj = globallist_next(&marker);
4185 TAILQ_REMOVE(&obj_list, &marker, next);
4187 lock_release(rtld_bind_lock, &bind_lockstate);
4188 lock_release(rtld_phdr_lock, &phdr_lockstate);
4194 rtld_fill_dl_phdr_info(&obj_rtld, &phdr_info);
4195 lock_release(rtld_bind_lock, &bind_lockstate);
4196 error = callback(&phdr_info, sizeof(phdr_info), param);
4198 lock_release(rtld_phdr_lock, &phdr_lockstate);
4203 fill_search_info(const char *dir, size_t dirlen, void *param)
4205 struct fill_search_info_args *arg;
4209 if (arg->request == RTLD_DI_SERINFOSIZE) {
4210 arg->serinfo->dls_cnt ++;
4211 arg->serinfo->dls_size += sizeof(struct dl_serpath) + dirlen + 1;
4213 struct dl_serpath *s_entry;
4215 s_entry = arg->serpath;
4216 s_entry->dls_name = arg->strspace;
4217 s_entry->dls_flags = arg->flags;
4219 strncpy(arg->strspace, dir, dirlen);
4220 arg->strspace[dirlen] = '\0';
4222 arg->strspace += dirlen + 1;
4230 do_search_info(const Obj_Entry *obj, int request, struct dl_serinfo *info)
4232 struct dl_serinfo _info;
4233 struct fill_search_info_args args;
4235 args.request = RTLD_DI_SERINFOSIZE;
4236 args.serinfo = &_info;
4238 _info.dls_size = __offsetof(struct dl_serinfo, dls_serpath);
4241 path_enumerate(obj->rpath, fill_search_info, NULL, &args);
4242 path_enumerate(ld_library_path, fill_search_info, NULL, &args);
4243 path_enumerate(obj->runpath, fill_search_info, NULL, &args);
4244 path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args);
4245 if (!obj->z_nodeflib)
4246 path_enumerate(ld_standard_library_path, fill_search_info, NULL, &args);
4249 if (request == RTLD_DI_SERINFOSIZE) {
4250 info->dls_size = _info.dls_size;
4251 info->dls_cnt = _info.dls_cnt;
4255 if (info->dls_cnt != _info.dls_cnt || info->dls_size != _info.dls_size) {
4256 _rtld_error("Uninitialized Dl_serinfo struct passed to dlinfo()");
4260 args.request = RTLD_DI_SERINFO;
4261 args.serinfo = info;
4262 args.serpath = &info->dls_serpath[0];
4263 args.strspace = (char *)&info->dls_serpath[_info.dls_cnt];
4265 args.flags = LA_SER_RUNPATH;
4266 if (path_enumerate(obj->rpath, fill_search_info, NULL, &args) != NULL)
4269 args.flags = LA_SER_LIBPATH;
4270 if (path_enumerate(ld_library_path, fill_search_info, NULL, &args) != NULL)
4273 args.flags = LA_SER_RUNPATH;
4274 if (path_enumerate(obj->runpath, fill_search_info, NULL, &args) != NULL)
4277 args.flags = LA_SER_CONFIG;
4278 if (path_enumerate(gethints(obj->z_nodeflib), fill_search_info, NULL, &args)
4282 args.flags = LA_SER_DEFAULT;
4283 if (!obj->z_nodeflib && path_enumerate(ld_standard_library_path,
4284 fill_search_info, NULL, &args) != NULL)
4290 rtld_dirname(const char *path, char *bname)
4294 /* Empty or NULL string gets treated as "." */
4295 if (path == NULL || *path == '\0') {
4301 /* Strip trailing slashes */
4302 endp = path + strlen(path) - 1;
4303 while (endp > path && *endp == '/')
4306 /* Find the start of the dir */
4307 while (endp > path && *endp != '/')
4310 /* Either the dir is "/" or there are no slashes */
4312 bname[0] = *endp == '/' ? '/' : '.';
4318 } while (endp > path && *endp == '/');
4321 if (endp - path + 2 > PATH_MAX)
4323 _rtld_error("Filename is too long: %s", path);
4327 strncpy(bname, path, endp - path + 1);
4328 bname[endp - path + 1] = '\0';
4333 rtld_dirname_abs(const char *path, char *base)
4337 if (realpath(path, base) == NULL) {
4338 _rtld_error("realpath \"%s\" failed (%s)", path,
4339 rtld_strerror(errno));
4342 dbg("%s -> %s", path, base);
4343 last = strrchr(base, '/');
4345 _rtld_error("non-abs result from realpath \"%s\"", path);
4354 linkmap_add(Obj_Entry *obj)
4356 struct link_map *l, *prev;
4359 l->l_name = obj->path;
4360 l->l_base = obj->mapbase;
4361 l->l_ld = obj->dynamic;
4362 l->l_addr = obj->relocbase;
4364 if (r_debug.r_map == NULL) {
4370 * Scan to the end of the list, but not past the entry for the
4371 * dynamic linker, which we want to keep at the very end.
4373 for (prev = r_debug.r_map;
4374 prev->l_next != NULL && prev->l_next != &obj_rtld.linkmap;
4375 prev = prev->l_next)
4378 /* Link in the new entry. */
4380 l->l_next = prev->l_next;
4381 if (l->l_next != NULL)
4382 l->l_next->l_prev = l;
4387 linkmap_delete(Obj_Entry *obj)
4392 if (l->l_prev == NULL) {
4393 if ((r_debug.r_map = l->l_next) != NULL)
4394 l->l_next->l_prev = NULL;
4398 if ((l->l_prev->l_next = l->l_next) != NULL)
4399 l->l_next->l_prev = l->l_prev;
4403 * Function for the debugger to set a breakpoint on to gain control.
4405 * The two parameters allow the debugger to easily find and determine
4406 * what the runtime loader is doing and to whom it is doing it.
4408 * When the loadhook trap is hit (r_debug_state, set at program
4409 * initialization), the arguments can be found on the stack:
4411 * +8 struct link_map *m
4412 * +4 struct r_debug *rd
4416 r_debug_state(struct r_debug* rd __unused, struct link_map *m __unused)
4419 * The following is a hack to force the compiler to emit calls to
4420 * this function, even when optimizing. If the function is empty,
4421 * the compiler is not obliged to emit any code for calls to it,
4422 * even when marked __noinline. However, gdb depends on those
4425 __compiler_membar();
4429 * A function called after init routines have completed. This can be used to
4430 * break before a program's entry routine is called, and can be used when
4431 * main is not available in the symbol table.
4434 _r_debug_postinit(struct link_map *m __unused)
4437 /* See r_debug_state(). */
4438 __compiler_membar();
4442 release_object(Obj_Entry *obj)
4445 if (obj->holdcount > 0) {
4446 obj->unholdfree = true;
4449 munmap(obj->mapbase, obj->mapsize);
4450 linkmap_delete(obj);
4455 * Get address of the pointer variable in the main program.
4456 * Prefer non-weak symbol over the weak one.
4458 static const void **
4459 get_program_var_addr(const char *name, RtldLockState *lockstate)
4464 symlook_init(&req, name);
4465 req.lockstate = lockstate;
4466 donelist_init(&donelist);
4467 if (symlook_global(&req, &donelist) != 0)
4469 if (ELF_ST_TYPE(req.sym_out->st_info) == STT_FUNC)
4470 return ((const void **)make_function_pointer(req.sym_out,
4472 else if (ELF_ST_TYPE(req.sym_out->st_info) == STT_GNU_IFUNC)
4473 return ((const void **)rtld_resolve_ifunc(req.defobj_out, req.sym_out));
4475 return ((const void **)(req.defobj_out->relocbase +
4476 req.sym_out->st_value));
4480 * Set a pointer variable in the main program to the given value. This
4481 * is used to set key variables such as "environ" before any of the
4482 * init functions are called.
4485 set_program_var(const char *name, const void *value)
4489 if ((addr = get_program_var_addr(name, NULL)) != NULL) {
4490 dbg("\"%s\": *%p <-- %p", name, addr, value);
4496 * Search the global objects, including dependencies and main object,
4497 * for the given symbol.
4500 symlook_global(SymLook *req, DoneList *donelist)
4503 const Objlist_Entry *elm;
4506 symlook_init_from_req(&req1, req);
4508 /* Search all objects loaded at program start up. */
4509 if (req->defobj_out == NULL || (ld_dynamic_weak &&
4510 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK)) {
4511 res = symlook_list(&req1, &list_main, donelist);
4512 if (res == 0 && (!ld_dynamic_weak || req->defobj_out == NULL ||
4513 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
4514 req->sym_out = req1.sym_out;
4515 req->defobj_out = req1.defobj_out;
4516 assert(req->defobj_out != NULL);
4520 /* Search all DAGs whose roots are RTLD_GLOBAL objects. */
4521 STAILQ_FOREACH(elm, &list_global, link) {
4522 if (req->defobj_out != NULL && (!ld_dynamic_weak ||
4523 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK))
4525 res = symlook_list(&req1, &elm->obj->dagmembers, donelist);
4526 if (res == 0 && (req->defobj_out == NULL ||
4527 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
4528 req->sym_out = req1.sym_out;
4529 req->defobj_out = req1.defobj_out;
4530 assert(req->defobj_out != NULL);
4534 return (req->sym_out != NULL ? 0 : ESRCH);
4538 * Given a symbol name in a referencing object, find the corresponding
4539 * definition of the symbol. Returns a pointer to the symbol, or NULL if
4540 * no definition was found. Returns a pointer to the Obj_Entry of the
4541 * defining object via the reference parameter DEFOBJ_OUT.
4544 symlook_default(SymLook *req, const Obj_Entry *refobj)
4547 const Objlist_Entry *elm;
4551 donelist_init(&donelist);
4552 symlook_init_from_req(&req1, req);
4555 * Look first in the referencing object if linked symbolically,
4556 * and similarly handle protected symbols.
4558 res = symlook_obj(&req1, refobj);
4559 if (res == 0 && (refobj->symbolic ||
4560 ELF_ST_VISIBILITY(req1.sym_out->st_other) == STV_PROTECTED)) {
4561 req->sym_out = req1.sym_out;
4562 req->defobj_out = req1.defobj_out;
4563 assert(req->defobj_out != NULL);
4565 if (refobj->symbolic || req->defobj_out != NULL)
4566 donelist_check(&donelist, refobj);
4568 symlook_global(req, &donelist);
4570 /* Search all dlopened DAGs containing the referencing object. */
4571 STAILQ_FOREACH(elm, &refobj->dldags, link) {
4572 if (req->sym_out != NULL && (!ld_dynamic_weak ||
4573 ELF_ST_BIND(req->sym_out->st_info) != STB_WEAK))
4575 res = symlook_list(&req1, &elm->obj->dagmembers, &donelist);
4576 if (res == 0 && (req->sym_out == NULL ||
4577 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
4578 req->sym_out = req1.sym_out;
4579 req->defobj_out = req1.defobj_out;
4580 assert(req->defobj_out != NULL);
4585 * Search the dynamic linker itself, and possibly resolve the
4586 * symbol from there. This is how the application links to
4587 * dynamic linker services such as dlopen.
4589 if (req->sym_out == NULL ||
4590 ELF_ST_BIND(req->sym_out->st_info) == STB_WEAK) {
4591 res = symlook_obj(&req1, &obj_rtld);
4593 req->sym_out = req1.sym_out;
4594 req->defobj_out = req1.defobj_out;
4595 assert(req->defobj_out != NULL);
4599 return (req->sym_out != NULL ? 0 : ESRCH);
4603 symlook_list(SymLook *req, const Objlist *objlist, DoneList *dlp)
4606 const Obj_Entry *defobj;
4607 const Objlist_Entry *elm;
4613 STAILQ_FOREACH(elm, objlist, link) {
4614 if (donelist_check(dlp, elm->obj))
4616 symlook_init_from_req(&req1, req);
4617 if ((res = symlook_obj(&req1, elm->obj)) == 0) {
4618 if (def == NULL || (ld_dynamic_weak &&
4619 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
4621 defobj = req1.defobj_out;
4622 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK)
4629 req->defobj_out = defobj;
4636 * Search the chain of DAGS cointed to by the given Needed_Entry
4637 * for a symbol of the given name. Each DAG is scanned completely
4638 * before advancing to the next one. Returns a pointer to the symbol,
4639 * or NULL if no definition was found.
4642 symlook_needed(SymLook *req, const Needed_Entry *needed, DoneList *dlp)
4645 const Needed_Entry *n;
4646 const Obj_Entry *defobj;
4652 symlook_init_from_req(&req1, req);
4653 for (n = needed; n != NULL; n = n->next) {
4654 if (n->obj == NULL ||
4655 (res = symlook_list(&req1, &n->obj->dagmembers, dlp)) != 0)
4657 if (def == NULL || (ld_dynamic_weak &&
4658 ELF_ST_BIND(req1.sym_out->st_info) != STB_WEAK)) {
4660 defobj = req1.defobj_out;
4661 if (!ld_dynamic_weak || ELF_ST_BIND(def->st_info) != STB_WEAK)
4667 req->defobj_out = defobj;
4674 * Search the symbol table of a single shared object for a symbol of
4675 * the given name and version, if requested. Returns a pointer to the
4676 * symbol, or NULL if no definition was found. If the object is
4677 * filter, return filtered symbol from filtee.
4679 * The symbol's hash value is passed in for efficiency reasons; that
4680 * eliminates many recomputations of the hash value.
4683 symlook_obj(SymLook *req, const Obj_Entry *obj)
4687 int flags, res, mres;
4690 * If there is at least one valid hash at this point, we prefer to
4691 * use the faster GNU version if available.
4693 if (obj->valid_hash_gnu)
4694 mres = symlook_obj1_gnu(req, obj);
4695 else if (obj->valid_hash_sysv)
4696 mres = symlook_obj1_sysv(req, obj);
4701 if (obj->needed_filtees != NULL) {
4702 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
4703 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
4704 donelist_init(&donelist);
4705 symlook_init_from_req(&req1, req);
4706 res = symlook_needed(&req1, obj->needed_filtees, &donelist);
4708 req->sym_out = req1.sym_out;
4709 req->defobj_out = req1.defobj_out;
4713 if (obj->needed_aux_filtees != NULL) {
4714 flags = (req->flags & SYMLOOK_EARLY) ? RTLD_LO_EARLY : 0;
4715 load_filtees(__DECONST(Obj_Entry *, obj), flags, req->lockstate);
4716 donelist_init(&donelist);
4717 symlook_init_from_req(&req1, req);
4718 res = symlook_needed(&req1, obj->needed_aux_filtees, &donelist);
4720 req->sym_out = req1.sym_out;
4721 req->defobj_out = req1.defobj_out;
4729 /* Symbol match routine common to both hash functions */
4731 matched_symbol(SymLook *req, const Obj_Entry *obj, Sym_Match_Result *result,
4732 const unsigned long symnum)
4735 const Elf_Sym *symp;
4738 symp = obj->symtab + symnum;
4739 strp = obj->strtab + symp->st_name;
4741 switch (ELF_ST_TYPE(symp->st_info)) {
4747 if (symp->st_value == 0)
4751 if (symp->st_shndx != SHN_UNDEF)
4753 else if (((req->flags & SYMLOOK_IN_PLT) == 0) &&
4754 (ELF_ST_TYPE(symp->st_info) == STT_FUNC))
4760 if (req->name[0] != strp[0] || strcmp(req->name, strp) != 0)
4763 if (req->ventry == NULL) {
4764 if (obj->versyms != NULL) {
4765 verndx = VER_NDX(obj->versyms[symnum]);
4766 if (verndx > obj->vernum) {
4768 "%s: symbol %s references wrong version %d",
4769 obj->path, obj->strtab + symnum, verndx);
4773 * If we are not called from dlsym (i.e. this
4774 * is a normal relocation from unversioned
4775 * binary), accept the symbol immediately if
4776 * it happens to have first version after this
4777 * shared object became versioned. Otherwise,
4778 * if symbol is versioned and not hidden,
4779 * remember it. If it is the only symbol with
4780 * this name exported by the shared object, it
4781 * will be returned as a match by the calling
4782 * function. If symbol is global (verndx < 2)
4783 * accept it unconditionally.
4785 if ((req->flags & SYMLOOK_DLSYM) == 0 &&
4786 verndx == VER_NDX_GIVEN) {
4787 result->sym_out = symp;
4790 else if (verndx >= VER_NDX_GIVEN) {
4791 if ((obj->versyms[symnum] & VER_NDX_HIDDEN)
4793 if (result->vsymp == NULL)
4794 result->vsymp = symp;
4800 result->sym_out = symp;
4803 if (obj->versyms == NULL) {
4804 if (object_match_name(obj, req->ventry->name)) {
4805 _rtld_error("%s: object %s should provide version %s "
4806 "for symbol %s", obj_rtld.path, obj->path,
4807 req->ventry->name, obj->strtab + symnum);
4811 verndx = VER_NDX(obj->versyms[symnum]);
4812 if (verndx > obj->vernum) {
4813 _rtld_error("%s: symbol %s references wrong version %d",
4814 obj->path, obj->strtab + symnum, verndx);
4817 if (obj->vertab[verndx].hash != req->ventry->hash ||
4818 strcmp(obj->vertab[verndx].name, req->ventry->name)) {
4820 * Version does not match. Look if this is a
4821 * global symbol and if it is not hidden. If
4822 * global symbol (verndx < 2) is available,
4823 * use it. Do not return symbol if we are
4824 * called by dlvsym, because dlvsym looks for
4825 * a specific version and default one is not
4826 * what dlvsym wants.
4828 if ((req->flags & SYMLOOK_DLSYM) ||
4829 (verndx >= VER_NDX_GIVEN) ||
4830 (obj->versyms[symnum] & VER_NDX_HIDDEN))
4834 result->sym_out = symp;
4839 * Search for symbol using SysV hash function.
4840 * obj->buckets is known not to be NULL at this point; the test for this was
4841 * performed with the obj->valid_hash_sysv assignment.
4844 symlook_obj1_sysv(SymLook *req, const Obj_Entry *obj)
4846 unsigned long symnum;
4847 Sym_Match_Result matchres;
4849 matchres.sym_out = NULL;
4850 matchres.vsymp = NULL;
4851 matchres.vcount = 0;
4853 for (symnum = obj->buckets[req->hash % obj->nbuckets];
4854 symnum != STN_UNDEF; symnum = obj->chains[symnum]) {
4855 if (symnum >= obj->nchains)
4856 return (ESRCH); /* Bad object */
4858 if (matched_symbol(req, obj, &matchres, symnum)) {
4859 req->sym_out = matchres.sym_out;
4860 req->defobj_out = obj;
4864 if (matchres.vcount == 1) {
4865 req->sym_out = matchres.vsymp;
4866 req->defobj_out = obj;
4872 /* Search for symbol using GNU hash function */
4874 symlook_obj1_gnu(SymLook *req, const Obj_Entry *obj)
4876 Elf_Addr bloom_word;
4877 const Elf32_Word *hashval;
4879 Sym_Match_Result matchres;
4880 unsigned int h1, h2;
4881 unsigned long symnum;
4883 matchres.sym_out = NULL;
4884 matchres.vsymp = NULL;
4885 matchres.vcount = 0;
4887 /* Pick right bitmask word from Bloom filter array */
4888 bloom_word = obj->bloom_gnu[(req->hash_gnu / __ELF_WORD_SIZE) &
4889 obj->maskwords_bm_gnu];
4891 /* Calculate modulus word size of gnu hash and its derivative */
4892 h1 = req->hash_gnu & (__ELF_WORD_SIZE - 1);
4893 h2 = ((req->hash_gnu >> obj->shift2_gnu) & (__ELF_WORD_SIZE - 1));
4895 /* Filter out the "definitely not in set" queries */
4896 if (((bloom_word >> h1) & (bloom_word >> h2) & 1) == 0)
4899 /* Locate hash chain and corresponding value element*/
4900 bucket = obj->buckets_gnu[req->hash_gnu % obj->nbuckets_gnu];
4903 hashval = &obj->chain_zero_gnu[bucket];
4905 if (((*hashval ^ req->hash_gnu) >> 1) == 0) {
4906 symnum = hashval - obj->chain_zero_gnu;
4907 if (matched_symbol(req, obj, &matchres, symnum)) {
4908 req->sym_out = matchres.sym_out;
4909 req->defobj_out = obj;
4913 } while ((*hashval++ & 1) == 0);
4914 if (matchres.vcount == 1) {
4915 req->sym_out = matchres.vsymp;
4916 req->defobj_out = obj;
4923 trace_calc_fmts(const char **main_local, const char **fmt1, const char **fmt2)
4925 *main_local = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_PROGNAME);
4926 if (*main_local == NULL)
4929 *fmt1 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT1);
4931 *fmt1 = "\t%o => %p (%x)\n";
4933 *fmt2 = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_FMT2);
4935 *fmt2 = "\t%o (%x)\n";
4939 trace_print_obj(Obj_Entry *obj, const char *name, const char *path,
4940 const char *main_local, const char *fmt1, const char *fmt2)
4945 fmt = strncmp(name, "lib", 3) == 0 ? fmt1 : fmt2; /* XXX bogus */
4946 while ((c = *fmt++) != '\0') {
4972 rtld_putstr(main_local);
4975 rtld_putstr(obj_main->path);
4984 rtld_printf("%p", obj != NULL ?
4985 obj->mapbase : NULL);
4995 trace_loaded_objects(Obj_Entry *obj, bool show_preload)
4997 const char *fmt1, *fmt2, *main_local;
4998 const char *name, *path;
4999 bool first_spurious, list_containers;
5001 trace_calc_fmts(&main_local, &fmt1, &fmt2);
5002 list_containers = ld_get_env_var(LD_TRACE_LOADED_OBJECTS_ALL) != NULL;
5004 for (; obj != NULL; obj = TAILQ_NEXT(obj, next)) {
5005 Needed_Entry *needed;
5009 if (list_containers && obj->needed != NULL)
5010 rtld_printf("%s:\n", obj->path);
5011 for (needed = obj->needed; needed; needed = needed->next) {
5012 if (needed->obj != NULL) {
5013 if (needed->obj->traced && !list_containers)
5015 needed->obj->traced = true;
5016 path = needed->obj->path;
5020 name = obj->strtab + needed->name;
5021 trace_print_obj(obj, name, path, main_local,
5027 first_spurious = true;
5028 TAILQ_FOREACH(obj, &obj_list, next) {
5029 if (obj->marker || obj == obj_main || obj->traced)
5032 if (first_spurious) {
5033 rtld_printf("[preloaded]\n");
5034 first_spurious = false;
5036 Name_Entry *fname = STAILQ_FIRST(&obj->names);
5037 name = fname == NULL ? "<unknown>" : fname->name;
5038 trace_print_obj(obj, name, obj->path, main_local,
5045 * Unload a dlopened object and its dependencies from memory and from
5046 * our data structures. It is assumed that the DAG rooted in the
5047 * object has already been unreferenced, and that the object has a
5048 * reference count of 0.
5051 unload_object(Obj_Entry *root, RtldLockState *lockstate)
5053 Obj_Entry marker, *obj, *next;
5055 assert(root->refcount == 0);
5058 * Pass over the DAG removing unreferenced objects from
5059 * appropriate lists.
5061 unlink_object(root);
5063 /* Unmap all objects that are no longer referenced. */
5064 for (obj = TAILQ_FIRST(&obj_list); obj != NULL; obj = next) {
5065 next = TAILQ_NEXT(obj, next);
5066 if (obj->marker || obj->refcount != 0)
5068 LD_UTRACE(UTRACE_UNLOAD_OBJECT, obj, obj->mapbase,
5069 obj->mapsize, 0, obj->path);
5070 dbg("unloading \"%s\"", obj->path);
5072 * Unlink the object now to prevent new references from
5073 * being acquired while the bind lock is dropped in
5074 * recursive dlclose() invocations.
5076 TAILQ_REMOVE(&obj_list, obj, next);
5079 if (obj->filtees_loaded) {
5081 init_marker(&marker);
5082 TAILQ_INSERT_BEFORE(next, &marker, next);
5083 unload_filtees(obj, lockstate);
5084 next = TAILQ_NEXT(&marker, next);
5085 TAILQ_REMOVE(&obj_list, &marker, next);
5087 unload_filtees(obj, lockstate);
5089 release_object(obj);
5094 unlink_object(Obj_Entry *root)
5098 if (root->refcount == 0) {
5099 /* Remove the object from the RTLD_GLOBAL list. */
5100 objlist_remove(&list_global, root);
5102 /* Remove the object from all objects' DAG lists. */
5103 STAILQ_FOREACH(elm, &root->dagmembers, link) {
5104 objlist_remove(&elm->obj->dldags, root);
5105 if (elm->obj != root)
5106 unlink_object(elm->obj);
5112 ref_dag(Obj_Entry *root)
5116 assert(root->dag_inited);
5117 STAILQ_FOREACH(elm, &root->dagmembers, link)
5118 elm->obj->refcount++;
5122 unref_dag(Obj_Entry *root)
5126 assert(root->dag_inited);
5127 STAILQ_FOREACH(elm, &root->dagmembers, link)
5128 elm->obj->refcount--;
5132 * Common code for MD __tls_get_addr().
5135 tls_get_addr_slow(Elf_Addr **dtvp, int index, size_t offset, bool locked)
5137 Elf_Addr *newdtv, *dtv;
5138 RtldLockState lockstate;
5142 /* Check dtv generation in case new modules have arrived */
5143 if (dtv[0] != tls_dtv_generation) {
5145 wlock_acquire(rtld_bind_lock, &lockstate);
5146 newdtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
5148 if (to_copy > tls_max_index)
5149 to_copy = tls_max_index;
5150 memcpy(&newdtv[2], &dtv[2], to_copy * sizeof(Elf_Addr));
5151 newdtv[0] = tls_dtv_generation;
5152 newdtv[1] = tls_max_index;
5155 lock_release(rtld_bind_lock, &lockstate);
5156 dtv = *dtvp = newdtv;
5159 /* Dynamically allocate module TLS if necessary */
5160 if (dtv[index + 1] == 0) {
5161 /* Signal safe, wlock will block out signals. */
5163 wlock_acquire(rtld_bind_lock, &lockstate);
5164 if (!dtv[index + 1])
5165 dtv[index + 1] = (Elf_Addr)allocate_module_tls(index);
5167 lock_release(rtld_bind_lock, &lockstate);
5169 return ((void *)(dtv[index + 1] + offset));
5173 tls_get_addr_common(uintptr_t **dtvp, int index, size_t offset)
5178 /* Check dtv generation in case new modules have arrived */
5179 if (__predict_true(dtv[0] == tls_dtv_generation &&
5180 dtv[index + 1] != 0))
5181 return ((void *)(dtv[index + 1] + offset));
5182 return (tls_get_addr_slow(dtvp, index, offset, false));
5185 #ifdef TLS_VARIANT_I
5188 * Return pointer to allocated TLS block
5191 get_tls_block_ptr(void *tcb, size_t tcbsize)
5193 size_t extra_size, post_size, pre_size, tls_block_size;
5194 size_t tls_init_align;
5196 tls_init_align = MAX(obj_main->tlsalign, 1);
5198 /* Compute fragments sizes. */
5199 extra_size = tcbsize - TLS_TCB_SIZE;
5200 post_size = calculate_tls_post_size(tls_init_align);
5201 tls_block_size = tcbsize + post_size;
5202 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size;
5204 return ((char *)tcb - pre_size - extra_size);
5208 * Allocate Static TLS using the Variant I method.
5210 * For details on the layout, see lib/libc/gen/tls.c.
5212 * NB: rtld's tls_static_space variable includes TLS_TCB_SIZE and post_size as
5213 * it is based on tls_last_offset, and TLS offsets here are really TCB
5214 * offsets, whereas libc's tls_static_space is just the executable's static
5218 allocate_tls(Obj_Entry *objs, void *oldtcb, size_t tcbsize, size_t tcbalign)
5222 Elf_Addr *dtv, **tcb;
5225 size_t extra_size, maxalign, post_size, pre_size, tls_block_size;
5226 size_t tls_init_align, tls_init_offset;
5228 if (oldtcb != NULL && tcbsize == TLS_TCB_SIZE)
5231 assert(tcbsize >= TLS_TCB_SIZE);
5232 maxalign = MAX(tcbalign, tls_static_max_align);
5233 tls_init_align = MAX(obj_main->tlsalign, 1);
5235 /* Compute fragmets sizes. */
5236 extra_size = tcbsize - TLS_TCB_SIZE;
5237 post_size = calculate_tls_post_size(tls_init_align);
5238 tls_block_size = tcbsize + post_size;
5239 pre_size = roundup2(tls_block_size, tls_init_align) - tls_block_size;
5240 tls_block_size += pre_size + tls_static_space - TLS_TCB_SIZE - post_size;
5242 /* Allocate whole TLS block */
5243 tls_block = malloc_aligned(tls_block_size, maxalign, 0);
5244 tcb = (Elf_Addr **)(tls_block + pre_size + extra_size);
5246 if (oldtcb != NULL) {
5247 memcpy(tls_block, get_tls_block_ptr(oldtcb, tcbsize),
5249 free_aligned(get_tls_block_ptr(oldtcb, tcbsize));
5251 /* Adjust the DTV. */
5253 for (i = 0; i < dtv[1]; i++) {
5254 if (dtv[i+2] >= (Elf_Addr)oldtcb &&
5255 dtv[i+2] < (Elf_Addr)oldtcb + tls_static_space) {
5256 dtv[i+2] = dtv[i+2] - (Elf_Addr)oldtcb + (Elf_Addr)tcb;
5260 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
5262 dtv[0] = tls_dtv_generation;
5263 dtv[1] = tls_max_index;
5265 for (obj = globallist_curr(objs); obj != NULL;
5266 obj = globallist_next(obj)) {
5267 if (obj->tlsoffset == 0)
5269 tls_init_offset = obj->tlspoffset & (obj->tlsalign - 1);
5270 addr = (Elf_Addr)tcb + obj->tlsoffset;
5271 if (tls_init_offset > 0)
5272 memset((void *)addr, 0, tls_init_offset);
5273 if (obj->tlsinitsize > 0) {
5274 memcpy((void *)(addr + tls_init_offset), obj->tlsinit,
5277 if (obj->tlssize > obj->tlsinitsize) {
5278 memset((void *)(addr + tls_init_offset + obj->tlsinitsize),
5279 0, obj->tlssize - obj->tlsinitsize - tls_init_offset);
5281 dtv[obj->tlsindex + 1] = addr;
5289 free_tls(void *tcb, size_t tcbsize, size_t tcbalign __unused)
5292 Elf_Addr tlsstart, tlsend;
5294 size_t dtvsize, i, tls_init_align;
5296 assert(tcbsize >= TLS_TCB_SIZE);
5297 tls_init_align = MAX(obj_main->tlsalign, 1);
5299 /* Compute fragments sizes. */
5300 post_size = calculate_tls_post_size(tls_init_align);
5302 tlsstart = (Elf_Addr)tcb + TLS_TCB_SIZE + post_size;
5303 tlsend = (Elf_Addr)tcb + tls_static_space;
5305 dtv = *(Elf_Addr **)tcb;
5307 for (i = 0; i < dtvsize; i++) {
5308 if (dtv[i+2] && (dtv[i+2] < tlsstart || dtv[i+2] >= tlsend)) {
5309 free((void*)dtv[i+2]);
5313 free_aligned(get_tls_block_ptr(tcb, tcbsize));
5316 #endif /* TLS_VARIANT_I */
5318 #ifdef TLS_VARIANT_II
5321 * Allocate Static TLS using the Variant II method.
5324 allocate_tls(Obj_Entry *objs, void *oldtls, size_t tcbsize, size_t tcbalign)
5327 size_t size, ralign;
5329 Elf_Addr *dtv, *olddtv;
5330 Elf_Addr segbase, oldsegbase, addr;
5334 if (tls_static_max_align > ralign)
5335 ralign = tls_static_max_align;
5336 size = roundup(tls_static_space, ralign) + roundup(tcbsize, ralign);
5338 assert(tcbsize >= 2*sizeof(Elf_Addr));
5339 tls = malloc_aligned(size, ralign, 0 /* XXX */);
5340 dtv = xcalloc(tls_max_index + 2, sizeof(Elf_Addr));
5342 segbase = (Elf_Addr)(tls + roundup(tls_static_space, ralign));
5343 ((Elf_Addr *)segbase)[0] = segbase;
5344 ((Elf_Addr *)segbase)[1] = (Elf_Addr) dtv;
5346 dtv[0] = tls_dtv_generation;
5347 dtv[1] = tls_max_index;
5351 * Copy the static TLS block over whole.
5353 oldsegbase = (Elf_Addr) oldtls;
5354 memcpy((void *)(segbase - tls_static_space),
5355 (const void *)(oldsegbase - tls_static_space),
5359 * If any dynamic TLS blocks have been created tls_get_addr(),
5362 olddtv = ((Elf_Addr **)oldsegbase)[1];
5363 for (i = 0; i < olddtv[1]; i++) {
5364 if (olddtv[i + 2] < oldsegbase - size ||
5365 olddtv[i + 2] > oldsegbase) {
5366 dtv[i + 2] = olddtv[i + 2];
5372 * We assume that this block was the one we created with
5373 * allocate_initial_tls().
5375 free_tls(oldtls, 2 * sizeof(Elf_Addr), sizeof(Elf_Addr));
5377 for (obj = objs; obj != NULL; obj = TAILQ_NEXT(obj, next)) {
5378 if (obj->marker || obj->tlsoffset == 0)
5380 addr = segbase - obj->tlsoffset;
5381 memset((void *)(addr + obj->tlsinitsize),
5382 0, obj->tlssize - obj->tlsinitsize);
5384 memcpy((void *)addr, obj->tlsinit, obj->tlsinitsize);
5385 obj->static_tls_copied = true;
5387 dtv[obj->tlsindex + 1] = addr;
5391 return ((void *)segbase);
5395 free_tls(void *tls, size_t tcbsize __unused, size_t tcbalign)
5398 size_t size, ralign;
5400 Elf_Addr tlsstart, tlsend;
5403 * Figure out the size of the initial TLS block so that we can
5404 * find stuff which ___tls_get_addr() allocated dynamically.
5407 if (tls_static_max_align > ralign)
5408 ralign = tls_static_max_align;
5409 size = roundup(tls_static_space, ralign);
5411 dtv = ((Elf_Addr **)tls)[1];
5413 tlsend = (Elf_Addr)tls;
5414 tlsstart = tlsend - size;
5415 for (i = 0; i < dtvsize; i++) {
5416 if (dtv[i + 2] != 0 && (dtv[i + 2] < tlsstart ||
5417 dtv[i + 2] > tlsend)) {
5418 free_aligned((void *)dtv[i + 2]);
5422 free_aligned((void *)tlsstart);
5426 #endif /* TLS_VARIANT_II */
5429 * Allocate TLS block for module with given index.
5432 allocate_module_tls(int index)
5437 TAILQ_FOREACH(obj, &obj_list, next) {
5440 if (obj->tlsindex == index)
5444 _rtld_error("Can't find module with TLS index %d", index);
5448 p = malloc_aligned(obj->tlssize, obj->tlsalign, obj->tlspoffset);
5449 memcpy(p, obj->tlsinit, obj->tlsinitsize);
5450 memset(p + obj->tlsinitsize, 0, obj->tlssize - obj->tlsinitsize);
5455 allocate_tls_offset(Obj_Entry *obj)
5462 if (obj->tlssize == 0) {
5463 obj->tls_done = true;
5467 if (tls_last_offset == 0)
5468 off = calculate_first_tls_offset(obj->tlssize, obj->tlsalign,
5471 off = calculate_tls_offset(tls_last_offset, tls_last_size,
5472 obj->tlssize, obj->tlsalign, obj->tlspoffset);
5474 obj->tlsoffset = off;
5475 #ifdef TLS_VARIANT_I
5476 off += obj->tlssize;
5480 * If we have already fixed the size of the static TLS block, we
5481 * must stay within that size. When allocating the static TLS, we
5482 * leave a small amount of space spare to be used for dynamically
5483 * loading modules which use static TLS.
5485 if (tls_static_space != 0) {
5486 if (off > tls_static_space)
5488 } else if (obj->tlsalign > tls_static_max_align) {
5489 tls_static_max_align = obj->tlsalign;
5492 tls_last_offset = off;
5493 tls_last_size = obj->tlssize;
5494 obj->tls_done = true;
5500 free_tls_offset(Obj_Entry *obj)
5504 * If we were the last thing to allocate out of the static TLS
5505 * block, we give our space back to the 'allocator'. This is a
5506 * simplistic workaround to allow libGL.so.1 to be loaded and
5507 * unloaded multiple times.
5509 size_t off = obj->tlsoffset;
5510 #ifdef TLS_VARIANT_I
5511 off += obj->tlssize;
5513 if (off == tls_last_offset) {
5514 tls_last_offset -= obj->tlssize;
5520 _rtld_allocate_tls(void *oldtls, size_t tcbsize, size_t tcbalign)
5523 RtldLockState lockstate;
5525 wlock_acquire(rtld_bind_lock, &lockstate);
5526 ret = allocate_tls(globallist_curr(TAILQ_FIRST(&obj_list)), oldtls,
5528 lock_release(rtld_bind_lock, &lockstate);
5533 _rtld_free_tls(void *tcb, size_t tcbsize, size_t tcbalign)
5535 RtldLockState lockstate;
5537 wlock_acquire(rtld_bind_lock, &lockstate);
5538 free_tls(tcb, tcbsize, tcbalign);
5539 lock_release(rtld_bind_lock, &lockstate);
5543 object_add_name(Obj_Entry *obj, const char *name)
5549 entry = malloc(sizeof(Name_Entry) + len);
5551 if (entry != NULL) {
5552 strcpy(entry->name, name);
5553 STAILQ_INSERT_TAIL(&obj->names, entry, link);
5558 object_match_name(const Obj_Entry *obj, const char *name)
5562 STAILQ_FOREACH(entry, &obj->names, link) {
5563 if (strcmp(name, entry->name) == 0)
5570 locate_dependency(const Obj_Entry *obj, const char *name)
5572 const Objlist_Entry *entry;
5573 const Needed_Entry *needed;
5575 STAILQ_FOREACH(entry, &list_main, link) {
5576 if (object_match_name(entry->obj, name))
5577 return (entry->obj);
5580 for (needed = obj->needed; needed != NULL; needed = needed->next) {
5581 if (strcmp(obj->strtab + needed->name, name) == 0 ||
5582 (needed->obj != NULL && object_match_name(needed->obj, name))) {
5584 * If there is DT_NEEDED for the name we are looking for,
5585 * we are all set. Note that object might not be found if
5586 * dependency was not loaded yet, so the function can
5587 * return NULL here. This is expected and handled
5588 * properly by the caller.
5590 return (needed->obj);
5593 _rtld_error("%s: Unexpected inconsistency: dependency %s not found",
5599 check_object_provided_version(Obj_Entry *refobj, const Obj_Entry *depobj,
5600 const Elf_Vernaux *vna)
5602 const Elf_Verdef *vd;
5603 const char *vername;
5605 vername = refobj->strtab + vna->vna_name;
5606 vd = depobj->verdef;
5608 _rtld_error("%s: version %s required by %s not defined",
5609 depobj->path, vername, refobj->path);
5613 if (vd->vd_version != VER_DEF_CURRENT) {
5614 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
5615 depobj->path, vd->vd_version);
5618 if (vna->vna_hash == vd->vd_hash) {
5619 const Elf_Verdaux *aux = (const Elf_Verdaux *)
5620 ((const char *)vd + vd->vd_aux);
5621 if (strcmp(vername, depobj->strtab + aux->vda_name) == 0)
5624 if (vd->vd_next == 0)
5626 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next);
5628 if (vna->vna_flags & VER_FLG_WEAK)
5630 _rtld_error("%s: version %s required by %s not found",
5631 depobj->path, vername, refobj->path);
5636 rtld_verify_object_versions(Obj_Entry *obj)
5638 const Elf_Verneed *vn;
5639 const Elf_Verdef *vd;
5640 const Elf_Verdaux *vda;
5641 const Elf_Vernaux *vna;
5642 const Obj_Entry *depobj;
5643 int maxvernum, vernum;
5645 if (obj->ver_checked)
5647 obj->ver_checked = true;
5651 * Walk over defined and required version records and figure out
5652 * max index used by any of them. Do very basic sanity checking
5656 while (vn != NULL) {
5657 if (vn->vn_version != VER_NEED_CURRENT) {
5658 _rtld_error("%s: Unsupported version %d of Elf_Verneed entry",
5659 obj->path, vn->vn_version);
5662 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux);
5664 vernum = VER_NEED_IDX(vna->vna_other);
5665 if (vernum > maxvernum)
5667 if (vna->vna_next == 0)
5669 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next);
5671 if (vn->vn_next == 0)
5673 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next);
5677 while (vd != NULL) {
5678 if (vd->vd_version != VER_DEF_CURRENT) {
5679 _rtld_error("%s: Unsupported version %d of Elf_Verdef entry",
5680 obj->path, vd->vd_version);
5683 vernum = VER_DEF_IDX(vd->vd_ndx);
5684 if (vernum > maxvernum)
5686 if (vd->vd_next == 0)
5688 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next);
5695 * Store version information in array indexable by version index.
5696 * Verify that object version requirements are satisfied along the
5699 obj->vernum = maxvernum + 1;
5700 obj->vertab = xcalloc(obj->vernum, sizeof(Ver_Entry));
5703 while (vd != NULL) {
5704 if ((vd->vd_flags & VER_FLG_BASE) == 0) {
5705 vernum = VER_DEF_IDX(vd->vd_ndx);
5706 assert(vernum <= maxvernum);
5707 vda = (const Elf_Verdaux *)((const char *)vd + vd->vd_aux);
5708 obj->vertab[vernum].hash = vd->vd_hash;
5709 obj->vertab[vernum].name = obj->strtab + vda->vda_name;
5710 obj->vertab[vernum].file = NULL;
5711 obj->vertab[vernum].flags = 0;
5713 if (vd->vd_next == 0)
5715 vd = (const Elf_Verdef *)((const char *)vd + vd->vd_next);
5719 while (vn != NULL) {
5720 depobj = locate_dependency(obj, obj->strtab + vn->vn_file);
5723 vna = (const Elf_Vernaux *)((const char *)vn + vn->vn_aux);
5725 if (check_object_provided_version(obj, depobj, vna))
5727 vernum = VER_NEED_IDX(vna->vna_other);
5728 assert(vernum <= maxvernum);
5729 obj->vertab[vernum].hash = vna->vna_hash;
5730 obj->vertab[vernum].name = obj->strtab + vna->vna_name;
5731 obj->vertab[vernum].file = obj->strtab + vn->vn_file;
5732 obj->vertab[vernum].flags = (vna->vna_other & VER_NEED_HIDDEN) ?
5733 VER_INFO_HIDDEN : 0;
5734 if (vna->vna_next == 0)
5736 vna = (const Elf_Vernaux *)((const char *)vna + vna->vna_next);
5738 if (vn->vn_next == 0)
5740 vn = (const Elf_Verneed *)((const char *)vn + vn->vn_next);
5746 rtld_verify_versions(const Objlist *objlist)
5748 Objlist_Entry *entry;
5752 STAILQ_FOREACH(entry, objlist, link) {
5754 * Skip dummy objects or objects that have their version requirements
5757 if (entry->obj->strtab == NULL || entry->obj->vertab != NULL)
5759 if (rtld_verify_object_versions(entry->obj) == -1) {
5761 if (ld_tracing == NULL)
5765 if (rc == 0 || ld_tracing != NULL)
5766 rc = rtld_verify_object_versions(&obj_rtld);
5771 fetch_ventry(const Obj_Entry *obj, unsigned long symnum)
5776 vernum = VER_NDX(obj->versyms[symnum]);
5777 if (vernum >= obj->vernum) {
5778 _rtld_error("%s: symbol %s has wrong verneed value %d",
5779 obj->path, obj->strtab + symnum, vernum);
5780 } else if (obj->vertab[vernum].hash != 0) {
5781 return (&obj->vertab[vernum]);
5788 _rtld_get_stack_prot(void)
5791 return (stack_prot);
5795 _rtld_is_dlopened(void *arg)
5798 RtldLockState lockstate;
5801 rlock_acquire(rtld_bind_lock, &lockstate);
5804 obj = obj_from_addr(arg);
5806 _rtld_error("No shared object contains address");
5807 lock_release(rtld_bind_lock, &lockstate);
5810 res = obj->dlopened ? 1 : 0;
5811 lock_release(rtld_bind_lock, &lockstate);
5816 obj_remap_relro(Obj_Entry *obj, int prot)
5819 if (obj->relro_size > 0 && mprotect(obj->relro_page, obj->relro_size,
5821 _rtld_error("%s: Cannot set relro protection to %#x: %s",
5822 obj->path, prot, rtld_strerror(errno));
5829 obj_disable_relro(Obj_Entry *obj)
5832 return (obj_remap_relro(obj, PROT_READ | PROT_WRITE));
5836 obj_enforce_relro(Obj_Entry *obj)
5839 return (obj_remap_relro(obj, PROT_READ));
5843 map_stacks_exec(RtldLockState *lockstate)
5845 void (*thr_map_stacks_exec)(void);
5847 if ((max_stack_flags & PF_X) == 0 || (stack_prot & PROT_EXEC) != 0)
5849 thr_map_stacks_exec = (void (*)(void))(uintptr_t)
5850 get_program_var_addr("__pthread_map_stacks_exec", lockstate);
5851 if (thr_map_stacks_exec != NULL) {
5852 stack_prot |= PROT_EXEC;
5853 thr_map_stacks_exec();
5858 distribute_static_tls(Objlist *list, RtldLockState *lockstate)
5862 void (*distrib)(size_t, void *, size_t, size_t);
5864 distrib = (void (*)(size_t, void *, size_t, size_t))(uintptr_t)
5865 get_program_var_addr("__pthread_distribute_static_tls", lockstate);
5866 if (distrib == NULL)
5868 STAILQ_FOREACH(elm, list, link) {
5870 if (obj->marker || !obj->tls_done || obj->static_tls_copied)
5872 distrib(obj->tlsoffset, obj->tlsinit, obj->tlsinitsize,
5874 obj->static_tls_copied = true;
5879 symlook_init(SymLook *dst, const char *name)
5882 bzero(dst, sizeof(*dst));
5884 dst->hash = elf_hash(name);
5885 dst->hash_gnu = gnu_hash(name);
5889 symlook_init_from_req(SymLook *dst, const SymLook *src)
5892 dst->name = src->name;
5893 dst->hash = src->hash;
5894 dst->hash_gnu = src->hash_gnu;
5895 dst->ventry = src->ventry;
5896 dst->flags = src->flags;
5897 dst->defobj_out = NULL;
5898 dst->sym_out = NULL;
5899 dst->lockstate = src->lockstate;
5903 open_binary_fd(const char *argv0, bool search_in_path,
5904 const char **binpath_res)
5906 char *binpath, *pathenv, *pe, *res1;
5912 if (search_in_path && strchr(argv0, '/') == NULL) {
5913 binpath = xmalloc(PATH_MAX);
5914 pathenv = getenv("PATH");
5915 if (pathenv == NULL) {
5916 _rtld_error("-p and no PATH environment variable");
5919 pathenv = strdup(pathenv);
5920 if (pathenv == NULL) {
5921 _rtld_error("Cannot allocate memory");
5926 while ((pe = strsep(&pathenv, ":")) != NULL) {
5927 if (strlcpy(binpath, pe, PATH_MAX) >= PATH_MAX)
5929 if (binpath[0] != '\0' &&
5930 strlcat(binpath, "/", PATH_MAX) >= PATH_MAX)
5932 if (strlcat(binpath, argv0, PATH_MAX) >= PATH_MAX)
5934 fd = open(binpath, O_RDONLY | O_CLOEXEC | O_VERIFY);
5935 if (fd != -1 || errno != ENOENT) {
5942 fd = open(argv0, O_RDONLY | O_CLOEXEC | O_VERIFY);
5947 _rtld_error("Cannot open %s: %s", argv0, rtld_strerror(errno));
5950 if (res != NULL && res[0] != '/') {
5951 res1 = xmalloc(PATH_MAX);
5952 if (realpath(res, res1) != NULL) {
5954 free(__DECONST(char *, res));
5965 * Parse a set of command-line arguments.
5968 parse_args(char* argv[], int argc, bool *use_pathp, int *fdp,
5969 const char **argv0, bool *dir_ignore)
5974 int arglen, fd, i, j, mib[2];
5976 bool seen_b, seen_f;
5978 dbg("Parsing command-line arguments");
5981 *dir_ignore = false;
5982 seen_b = seen_f = false;
5984 for (i = 1; i < argc; i++ ) {
5986 dbg("argv[%d]: '%s'", i, arg);
5989 * rtld arguments end with an explicit "--" or with the first
5990 * non-prefixed argument.
5992 if (strcmp(arg, "--") == 0) {
6000 * All other arguments are single-character options that can
6001 * be combined, so we need to search through `arg` for them.
6003 arglen = strlen(arg);
6004 for (j = 1; j < arglen; j++) {
6007 print_usage(argv[0]);
6009 } else if (opt == 'b') {
6011 _rtld_error("Both -b and -f specified");
6018 } else if (opt == 'd') {
6021 } else if (opt == 'f') {
6023 _rtld_error("Both -b and -f specified");
6028 * -f XX can be used to specify a
6029 * descriptor for the binary named at
6030 * the command line (i.e., the later
6031 * argument will specify the process
6032 * name but the descriptor is what
6033 * will actually be executed).
6035 * -f must be the last option in, e.g., -abcf.
6037 if (j != arglen - 1) {
6038 _rtld_error("Invalid options: %s", arg);
6042 fd = parse_integer(argv[i]);
6045 "Invalid file descriptor: '%s'",
6052 } else if (opt == 'p') {
6054 } else if (opt == 'u') {
6056 } else if (opt == 'v') {
6059 mib[1] = HW_MACHINE;
6060 sz = sizeof(machine);
6061 sysctl(mib, nitems(mib), machine, &sz, NULL, 0);
6062 ld_elf_hints_path = ld_get_env_var(
6064 set_ld_elf_hints_path();
6066 "FreeBSD ld-elf.so.1 %s\n"
6067 "FreeBSD_version %d\n"
6068 "Default lib path %s\n"
6069 "Hints lib path %s\n"
6071 "Default hint file %s\n"
6075 __FreeBSD_version, ld_standard_library_path,
6077 ld_env_prefix, ld_elf_hints_default,
6079 ld_path_libmap_conf);
6082 _rtld_error("Invalid argument: '%s'", arg);
6083 print_usage(argv[0]);
6095 * Parse a file descriptor number without pulling in more of libc (e.g. atoi).
6098 parse_integer(const char *str)
6100 static const int RADIX = 10; /* XXXJA: possibly support hex? */
6107 for (c = *str; c != '\0'; c = *++str) {
6108 if (c < '0' || c > '9')
6115 /* Make sure we actually parsed something. */
6122 print_usage(const char *argv0)
6126 "Usage: %s [-h] [-b <exe>] [-d] [-f <FD>] [-p] [--] <binary> [<args>]\n"
6129 " -h Display this help message\n"
6130 " -b <exe> Execute <exe> instead of <binary>, arg0 is <binary>\n"
6131 " -d Ignore lack of exec permissions for the binary\n"
6132 " -f <FD> Execute <FD> instead of searching for <binary>\n"
6133 " -p Search in PATH for named binary\n"
6134 " -u Ignore LD_ environment variables\n"
6135 " -v Display identification information\n"
6136 " -- End of RTLD options\n"
6137 " <binary> Name of process to execute\n"
6138 " <args> Arguments to the executed process\n", argv0);
6141 #define AUXFMT(at, xfmt) [at] = { .name = #at, .fmt = xfmt }
6142 static const struct auxfmt {
6146 AUXFMT(AT_NULL, NULL),
6147 AUXFMT(AT_IGNORE, NULL),
6148 AUXFMT(AT_EXECFD, "%ld"),
6149 AUXFMT(AT_PHDR, "%p"),
6150 AUXFMT(AT_PHENT, "%lu"),
6151 AUXFMT(AT_PHNUM, "%lu"),
6152 AUXFMT(AT_PAGESZ, "%lu"),
6153 AUXFMT(AT_BASE, "%#lx"),
6154 AUXFMT(AT_FLAGS, "%#lx"),
6155 AUXFMT(AT_ENTRY, "%p"),
6156 AUXFMT(AT_NOTELF, NULL),
6157 AUXFMT(AT_UID, "%ld"),
6158 AUXFMT(AT_EUID, "%ld"),
6159 AUXFMT(AT_GID, "%ld"),
6160 AUXFMT(AT_EGID, "%ld"),
6161 AUXFMT(AT_EXECPATH, "%s"),
6162 AUXFMT(AT_CANARY, "%p"),
6163 AUXFMT(AT_CANARYLEN, "%lu"),
6164 AUXFMT(AT_OSRELDATE, "%lu"),
6165 AUXFMT(AT_NCPUS, "%lu"),
6166 AUXFMT(AT_PAGESIZES, "%p"),
6167 AUXFMT(AT_PAGESIZESLEN, "%lu"),
6168 AUXFMT(AT_TIMEKEEP, "%p"),
6169 AUXFMT(AT_STACKPROT, "%#lx"),
6170 AUXFMT(AT_EHDRFLAGS, "%#lx"),
6171 AUXFMT(AT_HWCAP, "%#lx"),
6172 AUXFMT(AT_HWCAP2, "%#lx"),
6173 AUXFMT(AT_BSDFLAGS, "%#lx"),
6174 AUXFMT(AT_ARGC, "%lu"),
6175 AUXFMT(AT_ARGV, "%p"),
6176 AUXFMT(AT_ENVC, "%p"),
6177 AUXFMT(AT_ENVV, "%p"),
6178 AUXFMT(AT_PS_STRINGS, "%p"),
6179 AUXFMT(AT_FXRNG, "%p"),
6180 AUXFMT(AT_KPRELOAD, "%p"),
6184 is_ptr_fmt(const char *fmt)
6188 last = fmt[strlen(fmt) - 1];
6189 return (last == 'p' || last == 's');
6193 dump_auxv(Elf_Auxinfo **aux_info)
6196 const struct auxfmt *fmt;
6199 for (i = 0; i < AT_COUNT; i++) {
6204 if (fmt->fmt == NULL)
6206 rtld_fdprintf(STDOUT_FILENO, "%s:\t", fmt->name);
6207 if (is_ptr_fmt(fmt->fmt)) {
6208 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt,
6211 rtld_fdprintfx(STDOUT_FILENO, fmt->fmt,
6214 rtld_fdprintf(STDOUT_FILENO, "\n");
6219 * Overrides for libc_pic-provided functions.
6223 __getosreldate(void)
6233 oid[1] = KERN_OSRELDATE;
6235 len = sizeof(osrel);
6236 error = sysctl(oid, 2, &osrel, &len, NULL, 0);
6237 if (error == 0 && osrel > 0 && len == sizeof(osrel))
6242 rtld_strerror(int errnum)
6245 if (errnum < 0 || errnum >= sys_nerr)
6246 return ("Unknown error");
6247 return (sys_errlist[errnum]);
6251 getenv(const char *name)
6253 return (__DECONST(char *, rtld_get_env_val(environ, name,
6259 malloc(size_t nbytes)
6262 return (__crt_malloc(nbytes));
6266 calloc(size_t num, size_t size)
6269 return (__crt_calloc(num, size));
6280 realloc(void *cp, size_t nbytes)
6283 return (__crt_realloc(cp, nbytes));
6286 extern int _rtld_version__FreeBSD_version __exported;
6287 int _rtld_version__FreeBSD_version = __FreeBSD_version;
6289 extern char _rtld_version_laddr_offset __exported;
6290 char _rtld_version_laddr_offset;
6292 extern char _rtld_version_dlpi_tls_data __exported;
6293 char _rtld_version_dlpi_tls_data;