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 /* Compute load address for a virtual address in a given dso. */
126 #define laddr(p, v) (void *)((p)->base + (v))
128 static void decode_vec(size_t *v, size_t *a, size_t cnt)
131 for (i=0; i<cnt; i++) a[i] = 0;
132 for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
138 static int search_vec(size_t *v, size_t *r, size_t key)
140 for (; v[0]!=key; v+=2)
146 static uint32_t sysv_hash(const char *s0)
148 const unsigned char *s = (void *)s0;
154 return h & 0xfffffff;
157 static uint32_t gnu_hash(const char *s0)
159 const unsigned char *s = (void *)s0;
160 uint_fast32_t h = 5381;
166 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
169 Sym *syms = dso->syms;
170 uint32_t *hashtab = dso->hashtab;
171 char *strings = dso->strings;
172 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
173 if ((!dso->versym || dso->versym[i] >= 0)
174 && (!strcmp(s, strings+syms[i].st_name)))
180 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
182 uint32_t nbuckets = hashtab[0];
183 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
184 uint32_t i = buckets[h1 % nbuckets];
188 uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
190 for (h1 |= 1; ; i++) {
191 uint32_t h2 = *hashval++;
192 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
193 && !strcmp(s, dso->strings + dso->syms[i].st_name))
201 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
203 const size_t *bloomwords = (const void *)(hashtab+4);
204 size_t f = bloomwords[fofs & (hashtab[2]-1)];
205 if (!(f & fmask)) return 0;
207 f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
208 if (!(f & 1)) return 0;
210 return gnu_lookup(h1, hashtab, dso, s);
213 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
214 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
216 #ifndef ARCH_SYM_REJECT_UND
217 #define ARCH_SYM_REJECT_UND(s) 0
220 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
222 uint32_t h = 0, gh, gho, *ght;
224 struct symdef def = {0};
225 for (; dso; dso=dso->next) {
227 if (!dso->global) continue;
228 if ((ght = dso->ghashtab)) {
231 int maskbits = 8 * sizeof ghm;
233 ghm = 1ul << gh % maskbits;
235 sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
237 if (!h) h = sysv_hash(s);
238 sym = sysv_lookup(s, h, dso);
242 if (need_def || (sym->st_info&0xf) == STT_TLS
243 || ARCH_SYM_REJECT_UND(sym))
246 if ((sym->st_info&0xf) != STT_TLS)
248 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
249 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
251 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
254 if (sym->st_info>>4 == STB_GLOBAL) break;
259 __attribute__((__visibility__("hidden")))
260 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
262 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
264 unsigned char *base = dso->base;
265 Sym *syms = dso->syms;
266 char *strings = dso->strings;
277 int skip_relative = 0, reuse_addends = 0, save_slot = 0;
280 /* Only ldso's REL table needs addend saving/reuse. */
281 if (rel == apply_addends_to)
286 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
287 if (skip_relative && IS_RELATIVE(rel[1])) continue;
288 type = R_TYPE(rel[1]);
289 if (type == REL_NONE) continue;
290 sym_index = R_SYM(rel[1]);
291 reloc_addr = (void *)(base + rel[0]);
293 sym = syms + sym_index;
294 name = strings + sym->st_name;
295 ctx = type==REL_COPY ? head->next : head;
296 def = find_sym(ctx, name, type==REL_PLT);
297 if (!def.sym && (sym->st_shndx != SHN_UNDEF
298 || sym->st_info>>4 != STB_WEAK)) {
299 error("Error relocating %s: %s: symbol not found",
301 if (runtime) longjmp(*rtld_fail, 1);
312 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
314 } else if (reuse_addends) {
315 /* Save original addend in stage 2 where the dso
316 * chain consists of just ldso; otherwise read back
317 * saved addend since the inline one was clobbered. */
319 saved_addends[save_slot] = *reloc_addr;
320 addend = saved_addends[save_slot++];
322 addend = *reloc_addr;
325 sym_val = def.sym ? (size_t)def.dso->base+def.sym->st_value : 0;
326 tls_val = def.sym ? def.sym->st_value : 0;
332 addend -= (size_t)reloc_addr;
336 *reloc_addr = sym_val + addend;
339 *reloc_addr = (size_t)base + addend;
342 if (sym) *reloc_addr = sym_val + addend;
343 else *reloc_addr = (size_t)base + addend;
346 memcpy(reloc_addr, (void *)sym_val, sym->st_size);
349 *(uint32_t *)reloc_addr = sym_val + addend
350 - (size_t)reloc_addr;
353 *reloc_addr = def.dso->tls_id;
356 *reloc_addr = tls_val + addend - DTP_OFFSET;
360 *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend;
364 *reloc_addr = tls_val - def.dso->tls_offset + addend;
367 *reloc_addr = def.dso->tls_offset - tls_val + addend;
371 if (stride<3) addend = reloc_addr[1];
372 if (runtime && def.dso->tls_id >= static_tls_cnt) {
373 struct td_index *new = malloc(sizeof *new);
376 "Error relocating %s: cannot allocate TLSDESC for %s",
377 dso->name, sym ? name : "(local)" );
378 longjmp(*rtld_fail, 1);
380 new->next = dso->td_index;
382 new->args[0] = def.dso->tls_id;
383 new->args[1] = tls_val + addend;
384 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
385 reloc_addr[1] = (size_t)new;
387 reloc_addr[0] = (size_t)__tlsdesc_static;
389 reloc_addr[1] = tls_val + def.dso->tls_offset
392 reloc_addr[1] = tls_val - def.dso->tls_offset
398 error("Error relocating %s: unsupported relocation type %d",
400 if (runtime) longjmp(*rtld_fail, 1);
406 /* A huge hack: to make up for the wastefulness of shared libraries
407 * needing at least a page of dirty memory even if they have no global
408 * data, we reclaim the gaps at the beginning and end of writable maps
409 * and "donate" them to the heap by setting up minimal malloc
410 * structures and then freeing them. */
412 static void reclaim(struct dso *dso, size_t start, size_t end)
415 if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
416 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
417 start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
418 end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
419 if (start>end || end-start < 4*sizeof(size_t)) return;
420 a = laddr(dso, start);
423 a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
428 static void reclaim_gaps(struct dso *dso)
430 Phdr *ph = dso->phdr;
431 size_t phcnt = dso->phnum;
433 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
434 if (ph->p_type!=PT_LOAD) continue;
435 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
436 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
437 reclaim(dso, ph->p_vaddr+ph->p_memsz,
438 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
442 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
444 char *q = mmap(p, n, prot, flags, fd, off);
445 if (q != MAP_FAILED || errno != EINVAL) return q;
446 /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
447 if (flags & MAP_ANONYMOUS) {
452 if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
453 for (q=p; n; q+=r, off+=r, n-=r) {
455 if (r < 0 && errno != EINTR) return MAP_FAILED;
464 static void *map_library(int fd, struct dso *dso)
466 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
467 void *allocated_buf=0;
469 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
470 size_t this_min, this_max;
475 unsigned char *map=MAP_FAILED, *base;
480 ssize_t l = read(fd, buf, sizeof buf);
483 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
485 phsize = eh->e_phentsize * eh->e_phnum;
486 if (phsize > sizeof buf - sizeof *eh) {
487 allocated_buf = malloc(phsize);
488 if (!allocated_buf) return 0;
489 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
490 if (l < 0) goto error;
491 if (l != phsize) goto noexec;
492 ph = ph0 = allocated_buf;
493 } else if (eh->e_phoff + phsize > l) {
494 l = pread(fd, buf+1, phsize, eh->e_phoff);
495 if (l < 0) goto error;
496 if (l != phsize) goto noexec;
497 ph = ph0 = (void *)(buf + 1);
499 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
501 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
502 if (ph->p_type == PT_DYNAMIC) {
504 } else if (ph->p_type == PT_TLS) {
505 tls_image = ph->p_vaddr;
506 dso->tls_align = ph->p_align;
507 dso->tls_len = ph->p_filesz;
508 dso->tls_size = ph->p_memsz;
509 } else if (ph->p_type == PT_GNU_RELRO) {
510 dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
511 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
513 if (ph->p_type != PT_LOAD) continue;
514 if (ph->p_vaddr < addr_min) {
515 addr_min = ph->p_vaddr;
516 off_start = ph->p_offset;
517 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
518 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
519 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
521 if (ph->p_vaddr+ph->p_memsz > addr_max) {
522 addr_max = ph->p_vaddr+ph->p_memsz;
525 if (!dyn) goto noexec;
526 addr_max += PAGE_SIZE-1;
527 addr_max &= -PAGE_SIZE;
528 addr_min &= -PAGE_SIZE;
529 off_start &= -PAGE_SIZE;
530 map_len = addr_max - addr_min + off_start;
531 /* The first time, we map too much, possibly even more than
532 * the length of the file. This is okay because we will not
533 * use the invalid part; we just need to reserve the right
534 * amount of virtual address space to map over later. */
535 map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
536 if (map==MAP_FAILED) goto error;
537 /* If the loaded file is not relocatable and the requested address is
538 * not available, then the load operation must fail. */
539 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
543 base = map - addr_min;
546 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
547 if (ph->p_type != PT_LOAD) continue;
548 /* Check if the programs headers are in this load segment, and
549 * if so, record the address for use by dl_iterate_phdr. */
550 if (!dso->phdr && eh->e_phoff >= ph->p_offset
551 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
552 dso->phdr = (void *)(base + ph->p_vaddr
553 + (eh->e_phoff-ph->p_offset));
554 dso->phnum = eh->e_phnum;
555 dso->phentsize = eh->e_phentsize;
557 /* Reuse the existing mapping for the lowest-address LOAD */
558 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
559 this_min = ph->p_vaddr & -PAGE_SIZE;
560 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
561 off_start = ph->p_offset & -PAGE_SIZE;
562 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
563 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
564 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
565 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
567 if (ph->p_memsz > ph->p_filesz) {
568 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
569 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
570 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
571 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)
575 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
576 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
577 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
583 dso->map_len = map_len;
585 dso->dynv = (void *)(base+dyn);
586 if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
587 if (!runtime) reclaim_gaps(dso);
593 if (map!=MAP_FAILED) munmap(map, map_len);
598 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
603 s += strspn(s, ":\n");
604 l = strcspn(s, ":\n");
605 if (l-1 >= INT_MAX) return -1;
606 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
607 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
615 /* Any negative value but -1 will inhibit
616 * futher path search. */
624 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
627 const char *s, *t, *origin;
629 if (p->rpath || !p->rpath_orig) return 0;
630 if (!strchr(p->rpath_orig, '$')) {
631 p->rpath = p->rpath_orig;
636 while ((t=strchr(s, '$'))) {
637 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
642 if (n > SSIZE_MAX/PATH_MAX) return 0;
644 if (p->kernel_mapped) {
645 /* $ORIGIN searches cannot be performed for the main program
646 * when it is suid/sgid/AT_SECURE. This is because the
647 * pathname is under the control of the caller of execve.
648 * For libraries, however, $ORIGIN can be processed safely
649 * since the library's pathname came from a trusted source
650 * (either system paths or a call to dlopen). */
653 l = readlink("/proc/self/exe", buf, buf_size);
654 if (l == -1) switch (errno) {
669 t = strrchr(origin, '/');
670 l = t ? t-origin : 0;
671 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
672 if (!p->rpath) return -1;
676 while ((t=strchr(s, '$'))) {
679 memcpy(d, origin, l);
681 /* It was determined previously that the '$' is followed
682 * either by "ORIGIN" or "{ORIGIN}". */
683 s = t + 7 + 2*(t[1]=='{');
689 static void decode_dyn(struct dso *p)
692 decode_vec(p->dynv, dyn, DYN_CNT);
693 p->syms = laddr(p, dyn[DT_SYMTAB]);
694 p->strings = laddr(p, dyn[DT_STRTAB]);
695 if (dyn[0]&(1<<DT_HASH))
696 p->hashtab = laddr(p, dyn[DT_HASH]);
697 if (dyn[0]&(1<<DT_RPATH))
698 p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
699 if (dyn[0]&(1<<DT_RUNPATH))
700 p->rpath_orig = (void *)(p->strings + dyn[DT_RUNPATH]);
701 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
702 p->ghashtab = laddr(p, *dyn);
703 if (search_vec(p->dynv, dyn, DT_VERSYM))
704 p->versym = laddr(p, *dyn);
707 static struct dso *load_library(const char *name, struct dso *needed_by)
709 char buf[2*NAME_MAX+2];
710 const char *pathname;
712 struct dso *p, temp_dso = {0};
724 /* Catch and block attempts to reload the implementation itself */
725 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
726 static const char *rp, reserved[] =
727 "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
728 char *z = strchr(name, '.');
731 for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
734 /* Track which names have been resolved
735 * and only report each one once. */
736 static unsigned reported;
737 unsigned mask = 1U<<(rp-reserved);
738 if (!(reported & mask)) {
740 dprintf(1, "\t%s => %s (%p)\n",
749 if (!strcmp(name, ldso.name)) is_self = 1;
754 tail = ldso.next ? ldso.next : &ldso;
758 if (strchr(name, '/')) {
760 fd = open(name, O_RDONLY|O_CLOEXEC);
762 /* Search for the name to see if it's already loaded */
763 for (p=head->next; p; p=p->next) {
764 if (p->shortname && !strcmp(p->shortname, name)) {
769 if (strlen(name) > NAME_MAX) return 0;
771 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
772 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
773 if (fixup_rpath(p, buf, sizeof buf) < 0)
774 fd = -2; /* Inhibit further search. */
776 fd = path_open(name, p->rpath, buf, sizeof buf);
782 if (ldso.name[0]=='/') {
784 for (s=t=z=ldso.name; *s; s++)
785 if (*s=='/') z=t, t=s;
786 prefix_len = z-ldso.name;
787 if (prefix_len < PATH_MAX)
794 char etc_ldso_path[prefix_len + 1
795 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
796 snprintf(etc_ldso_path, sizeof etc_ldso_path,
797 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
798 (int)prefix_len, prefix);
799 FILE *f = fopen(etc_ldso_path, "rbe");
801 if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
806 } else if (errno != ENOENT) {
810 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
811 fd = path_open(name, sys_path, buf, sizeof buf);
815 if (fd < 0) return 0;
816 if (fstat(fd, &st) < 0) {
820 for (p=head->next; p; p=p->next) {
821 if (p->dev == st.st_dev && p->ino == st.st_ino) {
822 /* If this library was previously loaded with a
823 * pathname but a search found the same inode,
824 * setup its shortname so it can be found by name. */
825 if (!p->shortname && pathname != name)
826 p->shortname = strrchr(p->name, '/')+1;
832 map = noload ? 0 : map_library(fd, &temp_dso);
836 /* Allocate storage for the new DSO. When there is TLS, this
837 * storage must include a reservation for all pre-existing
838 * threads to obtain copies of both the new TLS, and an
839 * extended DTV capable of storing an additional slot for
840 * the newly-loaded DSO. */
841 alloc_size = sizeof *p + strlen(pathname) + 1;
842 if (runtime && temp_dso.tls_image) {
843 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
844 + sizeof(void *) * (tls_cnt+3);
845 n_th = libc.threads_minus_1 + 1;
846 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
847 else alloc_size += n_th * per_th;
849 p = calloc(1, alloc_size);
851 munmap(map, temp_dso.map_len);
854 memcpy(p, &temp_dso, sizeof temp_dso);
859 p->needed_by = needed_by;
861 strcpy(p->name, pathname);
862 /* Add a shortname only if name arg was not an explicit pathname. */
863 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
865 p->tls_id = ++tls_cnt;
866 tls_align = MAXP2(tls_align, p->tls_align);
868 p->tls_offset = tls_offset + ( (tls_align-1) &
869 -(tls_offset + (uintptr_t)p->tls_image) );
870 tls_offset += p->tls_size;
872 tls_offset += p->tls_size + p->tls_align - 1;
873 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
875 p->tls_offset = tls_offset;
877 p->new_dtv = (void *)(-sizeof(size_t) &
878 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
879 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
886 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
891 static void load_deps(struct dso *p)
894 struct dso ***deps = &p->deps, **tmp, *dep;
895 for (; p; p=p->next) {
896 for (i=0; p->dynv[i]; i+=2) {
897 if (p->dynv[i] != DT_NEEDED) continue;
898 dep = load_library(p->strings + p->dynv[i+1], p);
900 error("Error loading shared library %s: %m (needed by %s)",
901 p->strings + p->dynv[i+1], p->name);
902 if (runtime) longjmp(*rtld_fail, 1);
906 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
907 if (!tmp) longjmp(*rtld_fail, 1);
916 static void load_preload(char *s)
921 for ( ; *s && (isspace(*s) || *s==':'); s++);
922 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
930 static void make_global(struct dso *p)
932 for (; p; p=p->next) p->global = 1;
935 static void do_mips_relocs(struct dso *p, size_t *got)
938 unsigned char *base = p->base;
939 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
943 while (i--) *got++ += (size_t)base;
945 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
946 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
947 Sym *sym = p->syms + j;
948 rel[0] = (unsigned char *)got - base;
949 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
950 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
951 do_relocs(p, rel, sizeof rel, 2);
955 static void reloc_all(struct dso *p)
958 for (; p; p=p->next) {
959 if (p->relocated) continue;
960 decode_vec(p->dynv, dyn, DYN_CNT);
961 if (NEED_MIPS_GOT_RELOCS)
962 do_mips_relocs(p, (void *)(p->base+dyn[DT_PLTGOT]));
963 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
964 2+(dyn[DT_PLTREL]==DT_RELA));
965 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
966 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
968 if (head != &ldso && p->relro_start != p->relro_end &&
969 mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ)
970 && errno != ENOSYS) {
971 error("Error relocating %s: RELRO protection failed: %m",
973 if (runtime) longjmp(*rtld_fail, 1);
980 static void kernel_mapped_dso(struct dso *p)
982 size_t min_addr = -1, max_addr = 0, cnt;
984 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
985 if (ph->p_type == PT_DYNAMIC) {
986 p->dynv = laddr(p, ph->p_vaddr);
987 } else if (ph->p_type == PT_GNU_RELRO) {
988 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
989 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
991 if (ph->p_type != PT_LOAD) continue;
992 if (ph->p_vaddr < min_addr)
993 min_addr = ph->p_vaddr;
994 if (ph->p_vaddr+ph->p_memsz > max_addr)
995 max_addr = ph->p_vaddr+ph->p_memsz;
997 min_addr &= -PAGE_SIZE;
998 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
999 p->map = p->base + min_addr;
1000 p->map_len = max_addr - min_addr;
1001 p->kernel_mapped = 1;
1004 static void do_fini()
1007 size_t dyn[DYN_CNT];
1008 for (p=fini_head; p; p=p->fini_next) {
1009 if (!p->constructed) continue;
1010 decode_vec(p->dynv, dyn, DYN_CNT);
1011 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1012 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1013 size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1014 while (n--) ((void (*)(void))*--fn)();
1016 #ifndef NO_LEGACY_INITFINI
1017 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1018 ((void (*)(void))laddr(p, dyn[DT_FINI]))();
1023 static void do_init_fini(struct dso *p)
1025 size_t dyn[DYN_CNT];
1026 int need_locking = libc.threads_minus_1;
1027 /* Allow recursive calls that arise when a library calls
1028 * dlopen from one of its constructors, but block any
1029 * other threads until all ctors have finished. */
1030 if (need_locking) pthread_mutex_lock(&init_fini_lock);
1031 for (; p; p=p->prev) {
1032 if (p->constructed) continue;
1034 decode_vec(p->dynv, dyn, DYN_CNT);
1035 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1036 p->fini_next = fini_head;
1039 #ifndef NO_LEGACY_INITFINI
1040 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1041 ((void (*)(void))laddr(p, dyn[DT_INIT]))();
1043 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1044 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1045 size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1046 while (n--) ((void (*)(void))*fn++)();
1048 if (!need_locking && libc.threads_minus_1) {
1050 pthread_mutex_lock(&init_fini_lock);
1053 if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1056 static void dl_debug_state(void)
1060 weak_alias(dl_debug_state, _dl_debug_state);
1064 pthread_t self = __pthread_self();
1066 for (p=head; p; p=p->next) {
1067 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
1068 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
1069 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
1070 p->tls_size - p->tls_len);
1071 if (p->tls_id == (size_t)self->dtv[0]) break;
1075 void *__copy_tls(unsigned char *mem)
1082 dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1);
1084 mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1085 td = (pthread_t)mem;
1086 mem += sizeof(struct pthread);
1088 for (p=head; p; p=p->next) {
1089 if (!p->tls_id) continue;
1090 dtv[p->tls_id] = mem + p->tls_offset;
1091 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1096 mem += libc.tls_size - sizeof(struct pthread);
1097 mem -= (uintptr_t)mem & (tls_align-1);
1098 td = (pthread_t)mem;
1100 for (p=head; p; p=p->next) {
1101 if (!p->tls_id) continue;
1102 dtv[p->tls_id] = mem - p->tls_offset;
1103 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1106 dtv[0] = (void *)tls_cnt;
1107 td->dtv = td->dtv_copy = dtv;
1111 __attribute__((__visibility__("hidden")))
1112 void *__tls_get_new(size_t *v)
1114 pthread_t self = __pthread_self();
1116 /* Block signals to make accessing new TLS async-signal-safe */
1118 __block_all_sigs(&set);
1119 if (v[0]<=(size_t)self->dtv[0]) {
1120 __restore_sigs(&set);
1121 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1124 /* This is safe without any locks held because, if the caller
1125 * is able to request the Nth entry of the DTV, the DSO list
1126 * must be valid at least that far out and it was synchronized
1127 * at program startup or by an already-completed call to dlopen. */
1129 for (p=head; p->tls_id != v[0]; p=p->next);
1131 /* Get new DTV space from new DSO if needed */
1132 if (v[0] > (size_t)self->dtv[0]) {
1133 void **newdtv = p->new_dtv +
1134 (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
1135 memcpy(newdtv, self->dtv,
1136 ((size_t)self->dtv[0]+1) * sizeof(void *));
1137 newdtv[0] = (void *)v[0];
1138 self->dtv = self->dtv_copy = newdtv;
1141 /* Get new TLS memory from all new DSOs up to the requested one */
1143 for (p=head; ; p=p->next) {
1144 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1145 mem = p->new_tls + (p->tls_size + p->tls_align)
1146 * a_fetch_add(&p->new_tls_idx,1);
1147 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1149 self->dtv[p->tls_id] = mem;
1150 memcpy(mem, p->tls_image, p->tls_len);
1151 if (p->tls_id == v[0]) break;
1153 __restore_sigs(&set);
1154 return mem + v[1] + DTP_OFFSET;
1157 static void update_tls_size()
1159 libc.tls_size = ALIGN(
1160 (1+tls_cnt) * sizeof(void *) +
1162 sizeof(struct pthread) +
1167 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1168 * following stage 2 and stage 3 functions via primitive symbolic lookup
1169 * since it does not have access to their addresses to begin with. */
1171 /* Stage 2 of the dynamic linker is called after relative relocations
1172 * have been processed. It can make function calls to static functions
1173 * and access string literals and static data, but cannot use extern
1174 * symbols. Its job is to perform symbolic relocations on the dynamic
1175 * linker itself, but some of the relocations performed may need to be
1176 * replaced later due to copy relocations in the main program. */
1178 void __dls2(unsigned char *base, size_t *sp)
1180 Ehdr *ehdr = (void *)base;
1182 ldso.name = ldso.shortname = "libc.so";
1184 ldso.phnum = ehdr->e_phnum;
1185 ldso.phdr = (void *)(base + ehdr->e_phoff);
1186 ldso.phentsize = ehdr->e_phentsize;
1187 kernel_mapped_dso(&ldso);
1190 /* Prepare storage for to save clobbered REL addends so they
1191 * can be reused in stage 3. There should be very few. If
1192 * something goes wrong and there are a huge number, abort
1193 * instead of risking stack overflow. */
1194 size_t dyn[DYN_CNT];
1195 decode_vec(ldso.dynv, dyn, DYN_CNT);
1196 size_t *rel = (void *)(base+dyn[DT_REL]);
1197 size_t rel_size = dyn[DT_RELSZ];
1198 size_t symbolic_rel_cnt = 0;
1199 apply_addends_to = rel;
1200 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1201 if (!IS_RELATIVE(rel[1])) symbolic_rel_cnt++;
1202 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1203 size_t addends[symbolic_rel_cnt+1];
1204 saved_addends = addends;
1211 /* Call dynamic linker stage-3, __dls3, looking it up
1212 * symbolically as a barrier against moving the address
1213 * load across the above relocation processing. */
1214 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1215 ((stage3_func)(ldso.base+dls3_def.sym->st_value))(sp);
1218 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1219 * fully functional. Its job is to load (if not already loaded) and
1220 * process dependencies and relocations for the main application and
1221 * transfer control to its entry point. */
1223 _Noreturn void __dls3(size_t *sp)
1225 static struct dso app, vdso;
1226 size_t aux[AUX_CNT], *auxv;
1228 char *env_preload=0;
1231 char **argv = (void *)(sp+1);
1232 char **argv_orig = argv;
1233 char **envp = argv+argc+1;
1235 /* Find aux vector just past environ[] and use it to initialize
1236 * global data that may be needed before we can make syscalls. */
1238 for (i=argc+1; argv[i]; i++);
1239 libc.auxv = auxv = (void *)(argv+i+1);
1240 decode_vec(auxv, aux, AUX_CNT);
1241 __hwcap = aux[AT_HWCAP];
1242 libc.page_size = aux[AT_PAGESZ];
1243 libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1244 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1246 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1247 * use during dynamic linking. If possible it will also serve as the
1248 * thread pointer at runtime. */
1249 libc.tls_size = sizeof builtin_tls;
1250 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1254 /* Only trust user/env if kernel says we're not suid/sgid */
1256 env_path = getenv("LD_LIBRARY_PATH");
1257 env_preload = getenv("LD_PRELOAD");
1260 /* If the main program was already loaded by the kernel,
1261 * AT_PHDR will point to some location other than the dynamic
1262 * linker's program headers. */
1263 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1264 size_t interp_off = 0;
1265 size_t tls_image = 0;
1266 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1267 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1268 app.phnum = aux[AT_PHNUM];
1269 app.phentsize = aux[AT_PHENT];
1270 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1271 if (phdr->p_type == PT_PHDR)
1272 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1273 else if (phdr->p_type == PT_INTERP)
1274 interp_off = (size_t)phdr->p_vaddr;
1275 else if (phdr->p_type == PT_TLS) {
1276 tls_image = phdr->p_vaddr;
1277 app.tls_len = phdr->p_filesz;
1278 app.tls_size = phdr->p_memsz;
1279 app.tls_align = phdr->p_align;
1282 if (app.tls_size) app.tls_image = laddr(&app, tls_image);
1283 if (interp_off) ldso.name = laddr(&app, interp_off);
1284 if ((aux[0] & (1UL<<AT_EXECFN))
1285 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1286 app.name = (char *)aux[AT_EXECFN];
1289 kernel_mapped_dso(&app);
1292 char *ldname = argv[0];
1293 size_t l = strlen(ldname);
1294 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1296 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1297 char *opt = argv[0]+2;
1298 *argv++ = (void *)-1;
1301 } else if (!memcmp(opt, "list", 5)) {
1303 } else if (!memcmp(opt, "library-path", 12)) {
1304 if (opt[12]=='=') env_path = opt+13;
1305 else if (opt[12]) *argv = 0;
1306 else if (*argv) env_path = *argv++;
1307 } else if (!memcmp(opt, "preload", 7)) {
1308 if (opt[7]=='=') env_preload = opt+8;
1309 else if (opt[7]) *argv = 0;
1310 else if (*argv) env_preload = *argv++;
1315 argv[-1] = (void *)(argc - (argv-argv_orig));
1317 dprintf(2, "musl libc\n"
1319 "Dynamic Program Loader\n"
1320 "Usage: %s [options] [--] pathname%s\n",
1321 __libc_get_version(), ldname,
1322 ldd_mode ? "" : " [args]");
1325 fd = open(argv[0], O_RDONLY);
1327 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1331 Ehdr *ehdr = (void *)map_library(fd, &app);
1333 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1340 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1341 /* Find the name that would have been used for the dynamic
1342 * linker had ldd not taken its place. */
1344 for (i=0; i<app.phnum; i++) {
1345 if (app.phdr[i].p_type == PT_INTERP)
1346 ldso.name = (void *)(app.base
1347 + app.phdr[i].p_vaddr);
1349 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1353 app.tls_id = tls_cnt = 1;
1356 tls_offset = app.tls_size
1357 + ( -((uintptr_t)app.tls_image + app.tls_size)
1358 & (app.tls_align-1) );
1360 tls_offset = app.tls_offset = app.tls_size
1361 + ( -((uintptr_t)app.tls_image + app.tls_size)
1362 & (app.tls_align-1) );
1364 tls_align = MAXP2(tls_align, app.tls_align);
1369 /* Attach to vdso, if provided by the kernel */
1370 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1371 Ehdr *ehdr = (void *)vdso_base;
1372 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1373 vdso.phnum = ehdr->e_phnum;
1374 vdso.phentsize = ehdr->e_phentsize;
1375 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1376 if (phdr->p_type == PT_DYNAMIC)
1377 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1378 if (phdr->p_type == PT_LOAD)
1379 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1382 vdso.shortname = "linux-gate.so.1";
1390 /* Initial dso chain consists only of the app. */
1393 /* Donate unused parts of app and library mapping to malloc */
1395 reclaim_gaps(&ldso);
1397 /* Load preload/needed libraries, add their symbols to the global
1398 * namespace, and perform all remaining relocations. */
1399 if (env_preload) load_preload(env_preload);
1403 #ifndef DYNAMIC_IS_RO
1404 for (i=0; app.dynv[i]; i+=2)
1405 if (app.dynv[i]==DT_DEBUG)
1406 app.dynv[i+1] = (size_t)&debug;
1409 /* The main program must be relocated LAST since it may contin
1410 * copy relocations which depend on libraries' relocations. */
1411 reloc_all(app.next);
1415 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1416 void *initial_tls = calloc(libc.tls_size, 1);
1418 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1419 argv[0], libc.tls_size);
1422 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1426 size_t tmp_tls_size = libc.tls_size;
1427 pthread_t self = __pthread_self();
1428 /* Temporarily set the tls size to the full size of
1429 * builtin_tls so that __copy_tls will use the same layout
1430 * as it did for before. Then check, just to be safe. */
1431 libc.tls_size = sizeof builtin_tls;
1432 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1433 libc.tls_size = tmp_tls_size;
1435 static_tls_cnt = tls_cnt;
1437 if (ldso_fail) _exit(127);
1438 if (ldd_mode) _exit(0);
1440 /* Switch to runtime mode: any further failures in the dynamic
1441 * linker are a reportable failure rather than a fatal startup
1446 debug.bp = dl_debug_state;
1448 debug.base = ldso.base;
1452 __init_libc(envp, argv[0]);
1457 CRTJMP((void *)aux[AT_ENTRY], argv-1);
1461 void *dlopen(const char *file, int mode)
1463 struct dso *volatile p, *orig_tail, *next;
1464 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1469 if (!file) return head;
1471 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1472 pthread_rwlock_wrlock(&lock);
1476 orig_tls_cnt = tls_cnt;
1477 orig_tls_offset = tls_offset;
1478 orig_tls_align = tls_align;
1480 noload = mode & RTLD_NOLOAD;
1483 if (setjmp(*rtld_fail)) {
1484 /* Clean up anything new that was (partially) loaded */
1485 if (p && p->deps) for (i=0; p->deps[i]; i++)
1486 if (p->deps[i]->global < 0)
1487 p->deps[i]->global = 0;
1488 for (p=orig_tail->next; p; p=next) {
1490 munmap(p->map, p->map_len);
1491 while (p->td_index) {
1492 void *tmp = p->td_index->next;
1496 if (p->rpath != p->rpath_orig)
1501 tls_cnt = orig_tls_cnt;
1502 tls_offset = orig_tls_offset;
1503 tls_align = orig_tls_align;
1508 } else p = load_library(file, head);
1512 "Library %s is not already loaded" :
1513 "Error loading shared library %s: %m",
1518 /* First load handling */
1521 if (p->deps) for (i=0; p->deps[i]; i++)
1522 if (!p->deps[i]->global)
1523 p->deps[i]->global = -1;
1524 if (!p->global) p->global = -1;
1526 if (p->deps) for (i=0; p->deps[i]; i++)
1527 if (p->deps[i]->global < 0)
1528 p->deps[i]->global = 0;
1529 if (p->global < 0) p->global = 0;
1532 if (mode & RTLD_GLOBAL) {
1533 if (p->deps) for (i=0; p->deps[i]; i++)
1534 p->deps[i]->global = 1;
1544 pthread_rwlock_unlock(&lock);
1545 if (p) do_init_fini(orig_tail);
1546 pthread_setcancelstate(cs, 0);
1550 static int invalid_dso_handle(void *h)
1553 for (p=head; p; p=p->next) if (h==p) return 0;
1554 error("Invalid library handle %p", (void *)h);
1558 void *__tls_get_addr(size_t *);
1560 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1563 uint32_t h = 0, gh = 0, *ght;
1565 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1566 if (p == RTLD_DEFAULT) {
1568 } else if (p == RTLD_NEXT) {
1569 for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1573 struct symdef def = find_sym(p, s, 0);
1574 if (!def.sym) goto failed;
1575 if ((def.sym->st_info&0xf) == STT_TLS)
1576 return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1577 return laddr(def.dso, def.sym->st_value);
1579 if (invalid_dso_handle(p))
1581 if ((ght = p->ghashtab)) {
1583 sym = gnu_lookup(gh, ght, p, s);
1586 sym = sysv_lookup(s, h, p);
1588 if (sym && (sym->st_info&0xf) == STT_TLS)
1589 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1590 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1591 return laddr(p, sym->st_value);
1592 if (p->deps) for (i=0; p->deps[i]; i++) {
1593 if ((ght = p->deps[i]->ghashtab)) {
1594 if (!gh) gh = gnu_hash(s);
1595 sym = gnu_lookup(gh, ght, p->deps[i], s);
1597 if (!h) h = sysv_hash(s);
1598 sym = sysv_lookup(s, h, p->deps[i]);
1600 if (sym && (sym->st_info&0xf) == STT_TLS)
1601 return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1602 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1603 return laddr(p->deps[i], sym->st_value);
1606 error("Symbol not found: %s", s);
1610 int __dladdr(const void *addr, Dl_info *info)
1620 pthread_rwlock_rdlock(&lock);
1621 for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1622 pthread_rwlock_unlock(&lock);
1627 strings = p->strings;
1629 nsym = p->hashtab[1];
1633 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1634 sym += p->ghashtab[1];
1635 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1636 if (buckets[i] > nsym)
1640 nsym -= p->ghashtab[1];
1641 hashval = buckets + p->ghashtab[0] + nsym;
1643 while (!(*hashval++ & 1));
1647 for (; nsym; nsym--, sym++) {
1649 && (1<<(sym->st_info&0xf) & OK_TYPES)
1650 && (1<<(sym->st_info>>4) & OK_BINDS)) {
1651 void *symaddr = laddr(p, sym->st_value);
1652 if (symaddr > addr || symaddr < best)
1655 bestname = strings + sym->st_name;
1656 if (addr == symaddr)
1661 if (!best) return 0;
1663 info->dli_fname = p->name;
1664 info->dli_fbase = p->base;
1665 info->dli_sname = bestname;
1666 info->dli_saddr = best;
1671 __attribute__((__visibility__("hidden")))
1672 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1675 pthread_rwlock_rdlock(&lock);
1676 res = do_dlsym(p, s, ra);
1677 pthread_rwlock_unlock(&lock);
1681 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1683 struct dso *current;
1684 struct dl_phdr_info info;
1686 for(current = head; current;) {
1687 info.dlpi_addr = (uintptr_t)current->base;
1688 info.dlpi_name = current->name;
1689 info.dlpi_phdr = current->phdr;
1690 info.dlpi_phnum = current->phnum;
1691 info.dlpi_adds = gencnt;
1693 info.dlpi_tls_modid = current->tls_id;
1694 info.dlpi_tls_data = current->tls_image;
1696 ret = (callback)(&info, sizeof (info), data);
1698 if (ret != 0) break;
1700 pthread_rwlock_rdlock(&lock);
1701 current = current->next;
1702 pthread_rwlock_unlock(&lock);
1707 static int invalid_dso_handle(void *h)
1709 error("Invalid library handle %p", (void *)h);
1712 void *dlopen(const char *file, int mode)
1714 error("Dynamic loading not supported");
1717 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1719 error("Symbol not found: %s", s);
1722 int __dladdr (const void *addr, Dl_info *info)
1728 int __dlinfo(void *dso, int req, void *res)
1730 if (invalid_dso_handle(dso)) return -1;
1731 if (req != RTLD_DI_LINKMAP) {
1732 error("Unsupported request %d", req);
1735 *(struct link_map **)res = dso;
1741 pthread_t self = __pthread_self();
1742 if (!self->dlerror_flag) return 0;
1743 self->dlerror_flag = 0;
1744 char *s = self->dlerror_buf;
1745 if (s == (void *)-1)
1746 return "Dynamic linker failed to allocate memory for error message";
1751 int dlclose(void *p)
1753 return invalid_dso_handle(p);
1756 void __dl_thread_cleanup(void)
1758 pthread_t self = __pthread_self();
1759 if (self->dlerror_buf != (void *)-1)
1760 free(self->dlerror_buf);
1763 static void error(const char *fmt, ...)
1769 vdprintf(2, fmt, ap);
1776 pthread_t self = __pthread_self();
1777 if (self->dlerror_buf != (void *)-1)
1778 free(self->dlerror_buf);
1779 size_t len = vsnprintf(0, 0, fmt, ap);
1781 char *buf = malloc(len+1);
1784 vsnprintf(buf, len+1, fmt, ap);
1789 self->dlerror_buf = buf;
1790 self->dlerror_flag = 1;