20 #include "pthread_impl.h"
24 static void error(const char *, ...);
28 #define MAXP2(a,b) (-(-(a)&-(b)))
29 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
41 struct td_index *next;
48 struct dso *next, *prev;
67 struct dso **deps, *needed_by;
68 char *rpath_orig, *rpath;
70 size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
71 size_t relro_start, relro_end;
73 unsigned char *new_tls;
74 volatile int new_dtv_idx, new_tls_idx;
75 struct td_index *td_index;
76 struct dso *fini_next;
86 int __init_tp(void *);
87 void __init_libc(char **, char *);
89 const char *__libc_get_version(void);
91 static struct builtin_tls {
96 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
98 #define ADDEND_LIMIT 4096
99 static size_t *saved_addends, *apply_addends_to;
101 static struct dso ldso;
102 static struct dso *head, *tail, *fini_head;
103 static char *env_path, *sys_path;
104 static unsigned long long gencnt;
107 static int ldso_fail;
109 static jmp_buf *rtld_fail;
110 static pthread_rwlock_t lock;
111 static struct debug debug;
112 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
113 static size_t static_tls_cnt;
114 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
116 struct debug *_dl_debug_addr = &debug;
118 static int dl_strcmp(const char *l, const char *r)
120 for (; *l==*r && *l; l++, r++);
121 return *(unsigned char *)l - *(unsigned char *)r;
123 #define strcmp(l,r) dl_strcmp(l,r)
125 static void decode_vec(size_t *v, size_t *a, size_t cnt)
128 for (i=0; i<cnt; i++) a[i] = 0;
129 for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
135 static int search_vec(size_t *v, size_t *r, size_t key)
137 for (; v[0]!=key; v+=2)
143 static uint32_t sysv_hash(const char *s0)
145 const unsigned char *s = (void *)s0;
151 return h & 0xfffffff;
154 static uint32_t gnu_hash(const char *s0)
156 const unsigned char *s = (void *)s0;
157 uint_fast32_t h = 5381;
163 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
166 Sym *syms = dso->syms;
167 uint32_t *hashtab = dso->hashtab;
168 char *strings = dso->strings;
169 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
170 if ((!dso->versym || dso->versym[i] >= 0)
171 && (!strcmp(s, strings+syms[i].st_name)))
177 static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
179 uint32_t *hashtab = dso->ghashtab;
180 uint32_t nbuckets = hashtab[0];
181 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
182 uint32_t i = buckets[h1 % nbuckets];
186 uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
188 for (h1 |= 1; ; i++) {
189 uint32_t h2 = *hashval++;
190 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
191 && !strcmp(s, dso->strings + dso->syms[i].st_name))
199 static Sym *gnu_lookup_filtered(const char *s, uint32_t h1, struct dso *dso, uint32_t fofs, size_t fmask)
201 uint32_t *hashtab = dso->ghashtab;
202 const size_t *bloomwords = (const void *)(hashtab+4);
203 size_t f = bloomwords[fofs & (hashtab[2]-1)];
204 if (!(f & fmask)) return 0;
206 f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
207 if (!(f & 1)) return 0;
209 return gnu_lookup(s, h1, dso);
212 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
213 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
215 #ifndef ARCH_SYM_REJECT_UND
216 #define ARCH_SYM_REJECT_UND(s) 0
219 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
221 uint32_t h = 0, gh, gho;
223 struct symdef def = {0};
224 for (; dso; dso=dso->next) {
226 if (!dso->global) continue;
230 int maskbits = 8 * sizeof ghm;
232 ghm = 1ul << gh % maskbits;
234 sym = gnu_lookup_filtered(s, gh, dso, gho, ghm);
236 if (!h) h = sysv_hash(s);
237 sym = sysv_lookup(s, h, dso);
241 if (need_def || (sym->st_info&0xf) == STT_TLS
242 || ARCH_SYM_REJECT_UND(sym))
245 if ((sym->st_info&0xf) != STT_TLS)
247 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
248 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
250 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
253 if (sym->st_info>>4 == STB_GLOBAL) break;
258 __attribute__((__visibility__("hidden")))
259 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
261 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
263 unsigned char *base = dso->base;
264 Sym *syms = dso->syms;
265 char *strings = dso->strings;
276 int skip_relative = 0, reuse_addends = 0, save_slot = 0;
279 /* Only ldso's REL table needs addend saving/reuse. */
280 if (rel == apply_addends_to)
285 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
286 if (skip_relative && IS_RELATIVE(rel[1])) continue;
287 type = R_TYPE(rel[1]);
288 if (type == REL_NONE) continue;
289 sym_index = R_SYM(rel[1]);
290 reloc_addr = (void *)(base + rel[0]);
292 sym = syms + sym_index;
293 name = strings + sym->st_name;
294 ctx = type==REL_COPY ? head->next : head;
295 def = find_sym(ctx, name, type==REL_PLT);
296 if (!def.sym && (sym->st_shndx != SHN_UNDEF
297 || sym->st_info>>4 != STB_WEAK)) {
298 error("Error relocating %s: %s: symbol not found",
300 if (runtime) longjmp(*rtld_fail, 1);
311 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
313 } else if (reuse_addends) {
314 /* Save original addend in stage 2 where the dso
315 * chain consists of just ldso; otherwise read back
316 * saved addend since the inline one was clobbered. */
318 saved_addends[save_slot] = *reloc_addr;
319 addend = saved_addends[save_slot++];
321 addend = *reloc_addr;
324 sym_val = def.sym ? (size_t)def.dso->base+def.sym->st_value : 0;
325 tls_val = def.sym ? def.sym->st_value : 0;
331 addend -= (size_t)reloc_addr;
335 *reloc_addr = sym_val + addend;
338 *reloc_addr = (size_t)base + addend;
341 if (sym) *reloc_addr = sym_val + addend;
342 else *reloc_addr = (size_t)base + addend;
345 memcpy(reloc_addr, (void *)sym_val, sym->st_size);
348 *(uint32_t *)reloc_addr = sym_val + addend
349 - (size_t)reloc_addr;
352 *reloc_addr = def.dso->tls_id;
355 *reloc_addr = tls_val + addend - DTP_OFFSET;
359 *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend;
363 *reloc_addr = tls_val - def.dso->tls_offset + addend;
366 *reloc_addr = def.dso->tls_offset - tls_val + addend;
370 if (stride<3) addend = reloc_addr[1];
371 if (runtime && def.dso->tls_id >= static_tls_cnt) {
372 struct td_index *new = malloc(sizeof *new);
375 "Error relocating %s: cannot allocate TLSDESC for %s",
376 dso->name, sym ? name : "(local)" );
377 longjmp(*rtld_fail, 1);
379 new->next = dso->td_index;
381 new->args[0] = def.dso->tls_id;
382 new->args[1] = tls_val + addend;
383 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
384 reloc_addr[1] = (size_t)new;
386 reloc_addr[0] = (size_t)__tlsdesc_static;
388 reloc_addr[1] = tls_val + def.dso->tls_offset
391 reloc_addr[1] = tls_val - def.dso->tls_offset
397 error("Error relocating %s: unsupported relocation type %d",
399 if (runtime) longjmp(*rtld_fail, 1);
405 /* A huge hack: to make up for the wastefulness of shared libraries
406 * needing at least a page of dirty memory even if they have no global
407 * data, we reclaim the gaps at the beginning and end of writable maps
408 * and "donate" them to the heap by setting up minimal malloc
409 * structures and then freeing them. */
411 static void reclaim(struct dso *dso, size_t start, size_t end)
414 if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
415 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
416 start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
417 end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
418 if (start>end || end-start < 4*sizeof(size_t)) return;
419 a = (size_t *)(dso->base + start);
420 z = (size_t *)(dso->base + end);
422 a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
427 static void reclaim_gaps(struct dso *dso)
429 Phdr *ph = dso->phdr;
430 size_t phcnt = dso->phnum;
432 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
433 if (ph->p_type!=PT_LOAD) continue;
434 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
435 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
436 reclaim(dso, ph->p_vaddr+ph->p_memsz,
437 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
441 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
443 char *q = mmap(p, n, prot, flags, fd, off);
444 if (q != MAP_FAILED || errno != EINVAL) return q;
445 /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
446 if (flags & MAP_ANONYMOUS) {
451 if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
452 for (q=p; n; q+=r, off+=r, n-=r) {
454 if (r < 0 && errno != EINTR) return MAP_FAILED;
463 static void *map_library(int fd, struct dso *dso)
465 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
466 void *allocated_buf=0;
468 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
469 size_t this_min, this_max;
474 unsigned char *map=MAP_FAILED, *base;
479 ssize_t l = read(fd, buf, sizeof buf);
482 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
484 phsize = eh->e_phentsize * eh->e_phnum;
485 if (phsize > sizeof buf - sizeof *eh) {
486 allocated_buf = malloc(phsize);
487 if (!allocated_buf) return 0;
488 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
489 if (l < 0) goto error;
490 if (l != phsize) goto noexec;
491 ph = ph0 = allocated_buf;
492 } else if (eh->e_phoff + phsize > l) {
493 l = pread(fd, buf+1, phsize, eh->e_phoff);
494 if (l < 0) goto error;
495 if (l != phsize) goto noexec;
496 ph = ph0 = (void *)(buf + 1);
498 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
500 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
501 if (ph->p_type == PT_DYNAMIC) {
503 } else if (ph->p_type == PT_TLS) {
504 tls_image = ph->p_vaddr;
505 dso->tls_align = ph->p_align;
506 dso->tls_len = ph->p_filesz;
507 dso->tls_size = ph->p_memsz;
508 } else if (ph->p_type == PT_GNU_RELRO) {
509 dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
510 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
512 if (ph->p_type != PT_LOAD) continue;
513 if (ph->p_vaddr < addr_min) {
514 addr_min = ph->p_vaddr;
515 off_start = ph->p_offset;
516 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
517 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
518 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
520 if (ph->p_vaddr+ph->p_memsz > addr_max) {
521 addr_max = ph->p_vaddr+ph->p_memsz;
524 if (!dyn) goto noexec;
525 addr_max += PAGE_SIZE-1;
526 addr_max &= -PAGE_SIZE;
527 addr_min &= -PAGE_SIZE;
528 off_start &= -PAGE_SIZE;
529 map_len = addr_max - addr_min + off_start;
530 /* The first time, we map too much, possibly even more than
531 * the length of the file. This is okay because we will not
532 * use the invalid part; we just need to reserve the right
533 * amount of virtual address space to map over later. */
534 map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
535 if (map==MAP_FAILED) goto error;
536 /* If the loaded file is not relocatable and the requested address is
537 * not available, then the load operation must fail. */
538 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
542 base = map - addr_min;
545 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
546 if (ph->p_type != PT_LOAD) continue;
547 /* Check if the programs headers are in this load segment, and
548 * if so, record the address for use by dl_iterate_phdr. */
549 if (!dso->phdr && eh->e_phoff >= ph->p_offset
550 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
551 dso->phdr = (void *)(base + ph->p_vaddr
552 + (eh->e_phoff-ph->p_offset));
553 dso->phnum = eh->e_phnum;
554 dso->phentsize = eh->e_phentsize;
556 /* Reuse the existing mapping for the lowest-address LOAD */
557 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
558 this_min = ph->p_vaddr & -PAGE_SIZE;
559 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
560 off_start = ph->p_offset & -PAGE_SIZE;
561 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
562 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
563 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
564 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
566 if (ph->p_memsz > ph->p_filesz) {
567 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
568 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
569 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
570 if (pgbrk-(size_t)base < this_max && mmap_fixed((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
574 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
575 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
576 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
582 dso->map_len = map_len;
584 dso->dynv = (void *)(base+dyn);
585 if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
586 if (!runtime) reclaim_gaps(dso);
592 if (map!=MAP_FAILED) munmap(map, map_len);
597 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
602 s += strspn(s, ":\n");
603 l = strcspn(s, ":\n");
604 if (l-1 >= INT_MAX) return -1;
605 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
606 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
614 /* Any negative value but -1 will inhibit
615 * futher path search. */
623 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
626 const char *s, *t, *origin;
628 if (p->rpath || !p->rpath_orig) return 0;
629 if (!strchr(p->rpath_orig, '$')) {
630 p->rpath = p->rpath_orig;
635 while ((t=strchr(s, '$'))) {
636 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
641 if (n > SSIZE_MAX/PATH_MAX) return 0;
643 if (p->kernel_mapped) {
644 /* $ORIGIN searches cannot be performed for the main program
645 * when it is suid/sgid/AT_SECURE. This is because the
646 * pathname is under the control of the caller of execve.
647 * For libraries, however, $ORIGIN can be processed safely
648 * since the library's pathname came from a trusted source
649 * (either system paths or a call to dlopen). */
652 l = readlink("/proc/self/exe", buf, buf_size);
653 if (l == -1) switch (errno) {
668 t = strrchr(origin, '/');
669 l = t ? t-origin : 0;
670 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
671 if (!p->rpath) return -1;
675 while ((t=strchr(s, '$'))) {
678 memcpy(d, origin, l);
680 /* It was determined previously that the '$' is followed
681 * either by "ORIGIN" or "{ORIGIN}". */
682 s = t + 7 + 2*(t[1]=='{');
688 static void decode_dyn(struct dso *p)
691 decode_vec(p->dynv, dyn, DYN_CNT);
692 p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
693 p->strings = (void *)(p->base + dyn[DT_STRTAB]);
694 if (dyn[0]&(1<<DT_HASH))
695 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
696 if (dyn[0]&(1<<DT_RPATH))
697 p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
698 if (dyn[0]&(1<<DT_RUNPATH))
699 p->rpath_orig = (void *)(p->strings + dyn[DT_RUNPATH]);
700 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
701 p->ghashtab = (void *)(p->base + *dyn);
702 if (search_vec(p->dynv, dyn, DT_VERSYM))
703 p->versym = (void *)(p->base + *dyn);
706 static struct dso *load_library(const char *name, struct dso *needed_by)
708 char buf[2*NAME_MAX+2];
709 const char *pathname;
711 struct dso *p, temp_dso = {0};
723 /* Catch and block attempts to reload the implementation itself */
724 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
725 static const char *rp, reserved[] =
726 "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
727 char *z = strchr(name, '.');
730 for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
733 /* Track which names have been resolved
734 * and only report each one once. */
735 static unsigned reported;
736 unsigned mask = 1U<<(rp-reserved);
737 if (!(reported & mask)) {
739 dprintf(1, "\t%s => %s (%p)\n",
748 if (!strcmp(name, ldso.name)) is_self = 1;
753 tail = ldso.next ? ldso.next : &ldso;
757 if (strchr(name, '/')) {
759 fd = open(name, O_RDONLY|O_CLOEXEC);
761 /* Search for the name to see if it's already loaded */
762 for (p=head->next; p; p=p->next) {
763 if (p->shortname && !strcmp(p->shortname, name)) {
768 if (strlen(name) > NAME_MAX) return 0;
770 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
771 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
772 if (fixup_rpath(p, buf, sizeof buf) < 0)
773 fd = -2; /* Inhibit further search. */
775 fd = path_open(name, p->rpath, buf, sizeof buf);
781 if (ldso.name[0]=='/') {
783 for (s=t=z=ldso.name; *s; s++)
784 if (*s=='/') z=t, t=s;
785 prefix_len = z-ldso.name;
786 if (prefix_len < PATH_MAX)
793 char etc_ldso_path[prefix_len + 1
794 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
795 snprintf(etc_ldso_path, sizeof etc_ldso_path,
796 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
797 (int)prefix_len, prefix);
798 FILE *f = fopen(etc_ldso_path, "rbe");
800 if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
805 } else if (errno != ENOENT) {
809 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
810 fd = path_open(name, sys_path, buf, sizeof buf);
814 if (fd < 0) return 0;
815 if (fstat(fd, &st) < 0) {
819 for (p=head->next; p; p=p->next) {
820 if (p->dev == st.st_dev && p->ino == st.st_ino) {
821 /* If this library was previously loaded with a
822 * pathname but a search found the same inode,
823 * setup its shortname so it can be found by name. */
824 if (!p->shortname && pathname != name)
825 p->shortname = strrchr(p->name, '/')+1;
831 map = noload ? 0 : map_library(fd, &temp_dso);
835 /* Allocate storage for the new DSO. When there is TLS, this
836 * storage must include a reservation for all pre-existing
837 * threads to obtain copies of both the new TLS, and an
838 * extended DTV capable of storing an additional slot for
839 * the newly-loaded DSO. */
840 alloc_size = sizeof *p + strlen(pathname) + 1;
841 if (runtime && temp_dso.tls_image) {
842 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
843 + sizeof(void *) * (tls_cnt+3);
844 n_th = libc.threads_minus_1 + 1;
845 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
846 else alloc_size += n_th * per_th;
848 p = calloc(1, alloc_size);
850 munmap(map, temp_dso.map_len);
853 memcpy(p, &temp_dso, sizeof temp_dso);
858 p->needed_by = needed_by;
860 strcpy(p->name, pathname);
861 /* Add a shortname only if name arg was not an explicit pathname. */
862 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
864 p->tls_id = ++tls_cnt;
865 tls_align = MAXP2(tls_align, p->tls_align);
867 p->tls_offset = tls_offset + ( (tls_align-1) &
868 -(tls_offset + (uintptr_t)p->tls_image) );
869 tls_offset += p->tls_size;
871 tls_offset += p->tls_size + p->tls_align - 1;
872 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
874 p->tls_offset = tls_offset;
876 p->new_dtv = (void *)(-sizeof(size_t) &
877 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
878 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
885 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
890 static void load_deps(struct dso *p)
893 struct dso ***deps = &p->deps, **tmp, *dep;
894 for (; p; p=p->next) {
895 for (i=0; p->dynv[i]; i+=2) {
896 if (p->dynv[i] != DT_NEEDED) continue;
897 dep = load_library(p->strings + p->dynv[i+1], p);
899 error("Error loading shared library %s: %m (needed by %s)",
900 p->strings + p->dynv[i+1], p->name);
901 if (runtime) longjmp(*rtld_fail, 1);
905 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
906 if (!tmp) longjmp(*rtld_fail, 1);
915 static void load_preload(char *s)
920 for ( ; *s && (isspace(*s) || *s==':'); s++);
921 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
929 static void make_global(struct dso *p)
931 for (; p; p=p->next) p->global = 1;
934 static void do_mips_relocs(struct dso *p, size_t *got)
937 unsigned char *base = p->base;
938 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
942 while (i--) *got++ += (size_t)base;
944 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
945 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
946 Sym *sym = p->syms + j;
947 rel[0] = (unsigned char *)got - base;
948 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
949 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
950 do_relocs(p, rel, sizeof rel, 2);
954 static void reloc_all(struct dso *p)
957 for (; p; p=p->next) {
958 if (p->relocated) continue;
959 decode_vec(p->dynv, dyn, DYN_CNT);
960 if (NEED_MIPS_GOT_RELOCS)
961 do_mips_relocs(p, (void *)(p->base+dyn[DT_PLTGOT]));
962 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
963 2+(dyn[DT_PLTREL]==DT_RELA));
964 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
965 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
967 if (head != &ldso && p->relro_start != p->relro_end &&
968 mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ)
969 && errno != ENOSYS) {
970 error("Error relocating %s: RELRO protection failed: %m",
972 if (runtime) longjmp(*rtld_fail, 1);
979 static void kernel_mapped_dso(struct dso *p)
981 size_t min_addr = -1, max_addr = 0, cnt;
983 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
984 if (ph->p_type == PT_DYNAMIC) {
985 p->dynv = (void *)(p->base + ph->p_vaddr);
986 } else if (ph->p_type == PT_GNU_RELRO) {
987 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
988 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
990 if (ph->p_type != PT_LOAD) continue;
991 if (ph->p_vaddr < min_addr)
992 min_addr = ph->p_vaddr;
993 if (ph->p_vaddr+ph->p_memsz > max_addr)
994 max_addr = ph->p_vaddr+ph->p_memsz;
996 min_addr &= -PAGE_SIZE;
997 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
998 p->map = p->base + min_addr;
999 p->map_len = max_addr - min_addr;
1000 p->kernel_mapped = 1;
1003 static void do_fini()
1006 size_t dyn[DYN_CNT];
1007 for (p=fini_head; p; p=p->fini_next) {
1008 if (!p->constructed) continue;
1009 decode_vec(p->dynv, dyn, DYN_CNT);
1010 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1011 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1012 size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
1013 while (n--) ((void (*)(void))*--fn)();
1015 #ifndef NO_LEGACY_INITFINI
1016 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1017 ((void (*)(void))(p->base + dyn[DT_FINI]))();
1022 static void do_init_fini(struct dso *p)
1024 size_t dyn[DYN_CNT];
1025 int need_locking = libc.threads_minus_1;
1026 /* Allow recursive calls that arise when a library calls
1027 * dlopen from one of its constructors, but block any
1028 * other threads until all ctors have finished. */
1029 if (need_locking) pthread_mutex_lock(&init_fini_lock);
1030 for (; p; p=p->prev) {
1031 if (p->constructed) continue;
1033 decode_vec(p->dynv, dyn, DYN_CNT);
1034 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1035 p->fini_next = fini_head;
1038 #ifndef NO_LEGACY_INITFINI
1039 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1040 ((void (*)(void))(p->base + dyn[DT_INIT]))();
1042 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1043 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1044 size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
1045 while (n--) ((void (*)(void))*fn++)();
1047 if (!need_locking && libc.threads_minus_1) {
1049 pthread_mutex_lock(&init_fini_lock);
1052 if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1055 static void dl_debug_state(void)
1059 weak_alias(dl_debug_state, _dl_debug_state);
1063 pthread_t self = __pthread_self();
1065 for (p=head; p; p=p->next) {
1066 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
1067 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
1068 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
1069 p->tls_size - p->tls_len);
1070 if (p->tls_id == (size_t)self->dtv[0]) break;
1074 void *__copy_tls(unsigned char *mem)
1081 dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1);
1083 mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1084 td = (pthread_t)mem;
1085 mem += sizeof(struct pthread);
1087 for (p=head; p; p=p->next) {
1088 if (!p->tls_id) continue;
1089 dtv[p->tls_id] = mem + p->tls_offset;
1090 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1095 mem += libc.tls_size - sizeof(struct pthread);
1096 mem -= (uintptr_t)mem & (tls_align-1);
1097 td = (pthread_t)mem;
1099 for (p=head; p; p=p->next) {
1100 if (!p->tls_id) continue;
1101 dtv[p->tls_id] = mem - p->tls_offset;
1102 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1105 dtv[0] = (void *)tls_cnt;
1106 td->dtv = td->dtv_copy = dtv;
1110 __attribute__((__visibility__("hidden")))
1111 void *__tls_get_new(size_t *v)
1113 pthread_t self = __pthread_self();
1115 /* Block signals to make accessing new TLS async-signal-safe */
1117 __block_all_sigs(&set);
1118 if (v[0]<=(size_t)self->dtv[0]) {
1119 __restore_sigs(&set);
1120 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1123 /* This is safe without any locks held because, if the caller
1124 * is able to request the Nth entry of the DTV, the DSO list
1125 * must be valid at least that far out and it was synchronized
1126 * at program startup or by an already-completed call to dlopen. */
1128 for (p=head; p->tls_id != v[0]; p=p->next);
1130 /* Get new DTV space from new DSO if needed */
1131 if (v[0] > (size_t)self->dtv[0]) {
1132 void **newdtv = p->new_dtv +
1133 (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
1134 memcpy(newdtv, self->dtv,
1135 ((size_t)self->dtv[0]+1) * sizeof(void *));
1136 newdtv[0] = (void *)v[0];
1137 self->dtv = self->dtv_copy = newdtv;
1140 /* Get new TLS memory from all new DSOs up to the requested one */
1142 for (p=head; ; p=p->next) {
1143 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1144 mem = p->new_tls + (p->tls_size + p->tls_align)
1145 * a_fetch_add(&p->new_tls_idx,1);
1146 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1148 self->dtv[p->tls_id] = mem;
1149 memcpy(mem, p->tls_image, p->tls_len);
1150 if (p->tls_id == v[0]) break;
1152 __restore_sigs(&set);
1153 return mem + v[1] + DTP_OFFSET;
1156 static void update_tls_size()
1158 libc.tls_size = ALIGN(
1159 (1+tls_cnt) * sizeof(void *) +
1161 sizeof(struct pthread) +
1166 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1167 * following stage 2 and stage 3 functions via primitive symbolic lookup
1168 * since it does not have access to their addresses to begin with. */
1170 /* Stage 2 of the dynamic linker is called after relative relocations
1171 * have been processed. It can make function calls to static functions
1172 * and access string literals and static data, but cannot use extern
1173 * symbols. Its job is to perform symbolic relocations on the dynamic
1174 * linker itself, but some of the relocations performed may need to be
1175 * replaced later due to copy relocations in the main program. */
1177 void __dls2(unsigned char *base, size_t *sp)
1179 Ehdr *ehdr = (void *)base;
1181 ldso.name = ldso.shortname = "libc.so";
1183 ldso.phnum = ehdr->e_phnum;
1184 ldso.phdr = (void *)(base + ehdr->e_phoff);
1185 ldso.phentsize = ehdr->e_phentsize;
1186 kernel_mapped_dso(&ldso);
1189 /* Prepare storage for to save clobbered REL addends so they
1190 * can be reused in stage 3. There should be very few. If
1191 * something goes wrong and there are a huge number, abort
1192 * instead of risking stack overflow. */
1193 size_t dyn[DYN_CNT];
1194 decode_vec(ldso.dynv, dyn, DYN_CNT);
1195 size_t *rel = (void *)(base+dyn[DT_REL]);
1196 size_t rel_size = dyn[DT_RELSZ];
1197 size_t symbolic_rel_cnt = 0;
1198 apply_addends_to = rel;
1199 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1200 if (!IS_RELATIVE(rel[1])) symbolic_rel_cnt++;
1201 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1202 size_t addends[symbolic_rel_cnt+1];
1203 saved_addends = addends;
1210 /* Call dynamic linker stage-3, __dls3, looking it up
1211 * symbolically as a barrier against moving the address
1212 * load across the above relocation processing. */
1213 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1214 ((stage3_func)(ldso.base+dls3_def.sym->st_value))(sp);
1217 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1218 * fully functional. Its job is to load (if not already loaded) and
1219 * process dependencies and relocations for the main application and
1220 * transfer control to its entry point. */
1222 _Noreturn void __dls3(size_t *sp)
1224 static struct dso app, vdso;
1225 size_t aux[AUX_CNT], *auxv;
1227 char *env_preload=0;
1230 char **argv = (void *)(sp+1);
1231 char **argv_orig = argv;
1232 char **envp = argv+argc+1;
1234 /* Find aux vector just past environ[] and use it to initialize
1235 * global data that may be needed before we can make syscalls. */
1237 for (i=argc+1; argv[i]; i++);
1238 libc.auxv = auxv = (void *)(argv+i+1);
1239 decode_vec(auxv, aux, AUX_CNT);
1240 __hwcap = aux[AT_HWCAP];
1241 libc.page_size = aux[AT_PAGESZ];
1242 libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1243 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1245 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1246 * use during dynamic linking. If possible it will also serve as the
1247 * thread pointer at runtime. */
1248 libc.tls_size = sizeof builtin_tls;
1249 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1253 /* Only trust user/env if kernel says we're not suid/sgid */
1255 env_path = getenv("LD_LIBRARY_PATH");
1256 env_preload = getenv("LD_PRELOAD");
1259 /* If the main program was already loaded by the kernel,
1260 * AT_PHDR will point to some location other than the dynamic
1261 * linker's program headers. */
1262 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1263 size_t interp_off = 0;
1264 size_t tls_image = 0;
1265 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1266 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1267 app.phnum = aux[AT_PHNUM];
1268 app.phentsize = aux[AT_PHENT];
1269 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1270 if (phdr->p_type == PT_PHDR)
1271 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1272 else if (phdr->p_type == PT_INTERP)
1273 interp_off = (size_t)phdr->p_vaddr;
1274 else if (phdr->p_type == PT_TLS) {
1275 tls_image = phdr->p_vaddr;
1276 app.tls_len = phdr->p_filesz;
1277 app.tls_size = phdr->p_memsz;
1278 app.tls_align = phdr->p_align;
1281 if (app.tls_size) app.tls_image = (char *)app.base + tls_image;
1282 if (interp_off) ldso.name = (char *)app.base + interp_off;
1283 if ((aux[0] & (1UL<<AT_EXECFN))
1284 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1285 app.name = (char *)aux[AT_EXECFN];
1288 kernel_mapped_dso(&app);
1291 char *ldname = argv[0];
1292 size_t l = strlen(ldname);
1293 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1295 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1296 char *opt = argv[0]+2;
1297 *argv++ = (void *)-1;
1300 } else if (!memcmp(opt, "list", 5)) {
1302 } else if (!memcmp(opt, "library-path", 12)) {
1303 if (opt[12]=='=') env_path = opt+13;
1304 else if (opt[12]) *argv = 0;
1305 else if (*argv) env_path = *argv++;
1306 } else if (!memcmp(opt, "preload", 7)) {
1307 if (opt[7]=='=') env_preload = opt+8;
1308 else if (opt[7]) *argv = 0;
1309 else if (*argv) env_preload = *argv++;
1314 argv[-1] = (void *)(argc - (argv-argv_orig));
1316 dprintf(2, "musl libc\n"
1318 "Dynamic Program Loader\n"
1319 "Usage: %s [options] [--] pathname%s\n",
1320 __libc_get_version(), ldname,
1321 ldd_mode ? "" : " [args]");
1324 fd = open(argv[0], O_RDONLY);
1326 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1330 Ehdr *ehdr = (void *)map_library(fd, &app);
1332 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1339 aux[AT_ENTRY] = (size_t)app.base + ehdr->e_entry;
1340 /* Find the name that would have been used for the dynamic
1341 * linker had ldd not taken its place. */
1343 for (i=0; i<app.phnum; i++) {
1344 if (app.phdr[i].p_type == PT_INTERP)
1345 ldso.name = (void *)(app.base
1346 + app.phdr[i].p_vaddr);
1348 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1352 app.tls_id = tls_cnt = 1;
1355 tls_offset = app.tls_size
1356 + ( -((uintptr_t)app.tls_image + app.tls_size)
1357 & (app.tls_align-1) );
1359 tls_offset = app.tls_offset = app.tls_size
1360 + ( -((uintptr_t)app.tls_image + app.tls_size)
1361 & (app.tls_align-1) );
1363 tls_align = MAXP2(tls_align, app.tls_align);
1368 /* Attach to vdso, if provided by the kernel */
1369 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1370 Ehdr *ehdr = (void *)vdso_base;
1371 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1372 vdso.phnum = ehdr->e_phnum;
1373 vdso.phentsize = ehdr->e_phentsize;
1374 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1375 if (phdr->p_type == PT_DYNAMIC)
1376 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1377 if (phdr->p_type == PT_LOAD)
1378 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1381 vdso.shortname = "linux-gate.so.1";
1389 /* Initial dso chain consists only of the app. */
1392 /* Donate unused parts of app and library mapping to malloc */
1394 reclaim_gaps(&ldso);
1396 /* Load preload/needed libraries, add their symbols to the global
1397 * namespace, and perform all remaining relocations. */
1398 if (env_preload) load_preload(env_preload);
1402 #ifndef DYNAMIC_IS_RO
1403 for (i=0; app.dynv[i]; i+=2)
1404 if (app.dynv[i]==DT_DEBUG)
1405 app.dynv[i+1] = (size_t)&debug;
1408 /* The main program must be relocated LAST since it may contin
1409 * copy relocations which depend on libraries' relocations. */
1410 reloc_all(app.next);
1414 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1415 void *initial_tls = calloc(libc.tls_size, 1);
1417 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1418 argv[0], libc.tls_size);
1421 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1425 size_t tmp_tls_size = libc.tls_size;
1426 pthread_t self = __pthread_self();
1427 /* Temporarily set the tls size to the full size of
1428 * builtin_tls so that __copy_tls will use the same layout
1429 * as it did for before. Then check, just to be safe. */
1430 libc.tls_size = sizeof builtin_tls;
1431 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1432 libc.tls_size = tmp_tls_size;
1434 static_tls_cnt = tls_cnt;
1436 if (ldso_fail) _exit(127);
1437 if (ldd_mode) _exit(0);
1439 /* Switch to runtime mode: any further failures in the dynamic
1440 * linker are a reportable failure rather than a fatal startup
1445 debug.bp = dl_debug_state;
1447 debug.base = ldso.base;
1451 __init_libc(envp, argv[0]);
1456 CRTJMP((void *)aux[AT_ENTRY], argv-1);
1460 void *dlopen(const char *file, int mode)
1462 struct dso *volatile p, *orig_tail, *next;
1463 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1468 if (!file) return head;
1470 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1471 pthread_rwlock_wrlock(&lock);
1475 orig_tls_cnt = tls_cnt;
1476 orig_tls_offset = tls_offset;
1477 orig_tls_align = tls_align;
1479 noload = mode & RTLD_NOLOAD;
1482 if (setjmp(*rtld_fail)) {
1483 /* Clean up anything new that was (partially) loaded */
1484 if (p && p->deps) for (i=0; p->deps[i]; i++)
1485 if (p->deps[i]->global < 0)
1486 p->deps[i]->global = 0;
1487 for (p=orig_tail->next; p; p=next) {
1489 munmap(p->map, p->map_len);
1490 while (p->td_index) {
1491 void *tmp = p->td_index->next;
1495 if (p->rpath != p->rpath_orig)
1500 tls_cnt = orig_tls_cnt;
1501 tls_offset = orig_tls_offset;
1502 tls_align = orig_tls_align;
1507 } else p = load_library(file, head);
1511 "Library %s is not already loaded" :
1512 "Error loading shared library %s: %m",
1517 /* First load handling */
1520 if (p->deps) for (i=0; p->deps[i]; i++)
1521 if (!p->deps[i]->global)
1522 p->deps[i]->global = -1;
1523 if (!p->global) p->global = -1;
1525 if (p->deps) for (i=0; p->deps[i]; i++)
1526 if (p->deps[i]->global < 0)
1527 p->deps[i]->global = 0;
1528 if (p->global < 0) p->global = 0;
1531 if (mode & RTLD_GLOBAL) {
1532 if (p->deps) for (i=0; p->deps[i]; i++)
1533 p->deps[i]->global = 1;
1543 pthread_rwlock_unlock(&lock);
1544 if (p) do_init_fini(orig_tail);
1545 pthread_setcancelstate(cs, 0);
1549 static int invalid_dso_handle(void *h)
1552 for (p=head; p; p=p->next) if (h==p) return 0;
1553 error("Invalid library handle %p", (void *)h);
1557 void *__tls_get_addr(size_t *);
1559 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1562 uint32_t h = 0, gh = 0;
1564 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1565 if (p == RTLD_DEFAULT) {
1567 } else if (p == RTLD_NEXT) {
1568 for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1572 struct symdef def = find_sym(p, s, 0);
1573 if (!def.sym) goto failed;
1574 if ((def.sym->st_info&0xf) == STT_TLS)
1575 return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1576 return def.dso->base + def.sym->st_value;
1578 if (invalid_dso_handle(p))
1582 sym = gnu_lookup(s, gh, p);
1585 sym = sysv_lookup(s, h, p);
1587 if (sym && (sym->st_info&0xf) == STT_TLS)
1588 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1589 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1590 return p->base + sym->st_value;
1591 if (p->deps) for (i=0; p->deps[i]; i++) {
1592 if (p->deps[i]->ghashtab) {
1593 if (!gh) gh = gnu_hash(s);
1594 sym = gnu_lookup(s, gh, p->deps[i]);
1596 if (!h) h = sysv_hash(s);
1597 sym = sysv_lookup(s, h, p->deps[i]);
1599 if (sym && (sym->st_info&0xf) == STT_TLS)
1600 return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1601 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1602 return p->deps[i]->base + sym->st_value;
1605 error("Symbol not found: %s", s);
1609 int __dladdr(const void *addr, Dl_info *info)
1619 pthread_rwlock_rdlock(&lock);
1620 for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1621 pthread_rwlock_unlock(&lock);
1626 strings = p->strings;
1628 nsym = p->hashtab[1];
1632 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1633 sym += p->ghashtab[1];
1634 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1635 if (buckets[i] > nsym)
1639 nsym -= p->ghashtab[1];
1640 hashval = buckets + p->ghashtab[0] + nsym;
1642 while (!(*hashval++ & 1));
1646 for (; nsym; nsym--, sym++) {
1648 && (1<<(sym->st_info&0xf) & OK_TYPES)
1649 && (1<<(sym->st_info>>4) & OK_BINDS)) {
1650 void *symaddr = p->base + sym->st_value;
1651 if (symaddr > addr || symaddr < best)
1654 bestname = strings + sym->st_name;
1655 if (addr == symaddr)
1660 if (!best) return 0;
1662 info->dli_fname = p->name;
1663 info->dli_fbase = p->base;
1664 info->dli_sname = bestname;
1665 info->dli_saddr = best;
1670 __attribute__((__visibility__("hidden")))
1671 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1674 pthread_rwlock_rdlock(&lock);
1675 res = do_dlsym(p, s, ra);
1676 pthread_rwlock_unlock(&lock);
1680 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1682 struct dso *current;
1683 struct dl_phdr_info info;
1685 for(current = head; current;) {
1686 info.dlpi_addr = (uintptr_t)current->base;
1687 info.dlpi_name = current->name;
1688 info.dlpi_phdr = current->phdr;
1689 info.dlpi_phnum = current->phnum;
1690 info.dlpi_adds = gencnt;
1692 info.dlpi_tls_modid = current->tls_id;
1693 info.dlpi_tls_data = current->tls_image;
1695 ret = (callback)(&info, sizeof (info), data);
1697 if (ret != 0) break;
1699 pthread_rwlock_rdlock(&lock);
1700 current = current->next;
1701 pthread_rwlock_unlock(&lock);
1706 static int invalid_dso_handle(void *h)
1708 error("Invalid library handle %p", (void *)h);
1711 void *dlopen(const char *file, int mode)
1713 error("Dynamic loading not supported");
1716 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1718 error("Symbol not found: %s", s);
1721 int __dladdr (const void *addr, Dl_info *info)
1727 int __dlinfo(void *dso, int req, void *res)
1729 if (invalid_dso_handle(dso)) return -1;
1730 if (req != RTLD_DI_LINKMAP) {
1731 error("Unsupported request %d", req);
1734 *(struct link_map **)res = dso;
1740 pthread_t self = __pthread_self();
1741 if (!self->dlerror_flag) return 0;
1742 self->dlerror_flag = 0;
1743 char *s = self->dlerror_buf;
1744 if (s == (void *)-1)
1745 return "Dynamic linker failed to allocate memory for error message";
1750 int dlclose(void *p)
1752 return invalid_dso_handle(p);
1755 void __dl_thread_cleanup(void)
1757 pthread_t self = __pthread_self();
1758 if (self->dlerror_buf != (void *)-1)
1759 free(self->dlerror_buf);
1762 static void error(const char *fmt, ...)
1768 vdprintf(2, fmt, ap);
1775 pthread_t self = __pthread_self();
1776 if (self->dlerror_buf != (void *)-1)
1777 free(self->dlerror_buf);
1778 size_t len = vsnprintf(0, 0, fmt, ap);
1780 char *buf = malloc(len+1);
1783 vsnprintf(buf, len+1, fmt, ap);
1788 self->dlerror_buf = buf;
1789 self->dlerror_flag = 1;