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 Sym *syms = dso->syms;
180 char *strings = dso->strings;
181 uint32_t *hashtab = dso->ghashtab;
182 uint32_t nbuckets = hashtab[0];
183 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
186 uint32_t i = buckets[h1 % nbuckets];
190 hashval = buckets + nbuckets + (i - hashtab[1]);
192 for (h1 |= 1; ; i++) {
194 if ((!dso->versym || dso->versym[i] >= 0)
195 && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name))
203 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
204 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
206 #ifndef ARCH_SYM_REJECT_UND
207 #define ARCH_SYM_REJECT_UND(s) 0
210 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
212 uint32_t h = 0, gh = 0;
213 struct symdef def = {0};
214 for (; dso; dso=dso->next) {
216 if (!dso->global) continue;
218 if (!gh) gh = gnu_hash(s);
219 sym = gnu_lookup(s, gh, dso);
221 if (!h) h = sysv_hash(s);
222 sym = sysv_lookup(s, h, dso);
226 if (need_def || (sym->st_info&0xf) == STT_TLS
227 || ARCH_SYM_REJECT_UND(sym))
230 if ((sym->st_info&0xf) != STT_TLS)
232 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
233 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
235 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
238 if (sym->st_info>>4 == STB_GLOBAL) break;
243 __attribute__((__visibility__("hidden")))
244 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
246 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
248 unsigned char *base = dso->base;
249 Sym *syms = dso->syms;
250 char *strings = dso->strings;
261 int skip_relative = 0, reuse_addends = 0, save_slot = 0;
264 /* Only ldso's REL table needs addend saving/reuse. */
265 if (rel == apply_addends_to)
270 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
271 if (skip_relative && IS_RELATIVE(rel[1])) continue;
272 type = R_TYPE(rel[1]);
273 if (type == REL_NONE) continue;
274 sym_index = R_SYM(rel[1]);
275 reloc_addr = (void *)(base + rel[0]);
277 sym = syms + sym_index;
278 name = strings + sym->st_name;
279 ctx = type==REL_COPY ? head->next : head;
280 def = find_sym(ctx, name, type==REL_PLT);
281 if (!def.sym && (sym->st_shndx != SHN_UNDEF
282 || sym->st_info>>4 != STB_WEAK)) {
283 error("Error relocating %s: %s: symbol not found",
285 if (runtime) longjmp(*rtld_fail, 1);
296 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
298 } else if (reuse_addends) {
299 /* Save original addend in stage 2 where the dso
300 * chain consists of just ldso; otherwise read back
301 * saved addend since the inline one was clobbered. */
303 saved_addends[save_slot] = *reloc_addr;
304 addend = saved_addends[save_slot++];
306 addend = *reloc_addr;
309 sym_val = def.sym ? (size_t)def.dso->base+def.sym->st_value : 0;
310 tls_val = def.sym ? def.sym->st_value : 0;
316 addend -= (size_t)reloc_addr;
320 *reloc_addr = sym_val + addend;
323 *reloc_addr = (size_t)base + addend;
326 if (sym) *reloc_addr = sym_val + addend;
327 else *reloc_addr = (size_t)base + addend;
330 memcpy(reloc_addr, (void *)sym_val, sym->st_size);
333 *(uint32_t *)reloc_addr = sym_val + addend
334 - (size_t)reloc_addr;
337 *reloc_addr = def.dso->tls_id;
340 *reloc_addr = tls_val + addend;
344 *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend;
348 *reloc_addr = tls_val - def.dso->tls_offset + addend;
351 *reloc_addr = def.dso->tls_offset - tls_val + addend;
355 if (stride<3) addend = reloc_addr[1];
356 if (runtime && def.dso->tls_id >= static_tls_cnt) {
357 struct td_index *new = malloc(sizeof *new);
360 "Error relocating %s: cannot allocate TLSDESC for %s",
361 dso->name, sym ? name : "(local)" );
362 longjmp(*rtld_fail, 1);
364 new->next = dso->td_index;
366 new->args[0] = def.dso->tls_id;
367 new->args[1] = tls_val + addend;
368 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
369 reloc_addr[1] = (size_t)new;
371 reloc_addr[0] = (size_t)__tlsdesc_static;
373 reloc_addr[1] = tls_val + def.dso->tls_offset
376 reloc_addr[1] = tls_val - def.dso->tls_offset
382 error("Error relocating %s: unsupported relocation type %d",
384 if (runtime) longjmp(*rtld_fail, 1);
390 /* A huge hack: to make up for the wastefulness of shared libraries
391 * needing at least a page of dirty memory even if they have no global
392 * data, we reclaim the gaps at the beginning and end of writable maps
393 * and "donate" them to the heap by setting up minimal malloc
394 * structures and then freeing them. */
396 static void reclaim(struct dso *dso, size_t start, size_t end)
399 if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
400 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
401 start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
402 end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
403 if (start>end || end-start < 4*sizeof(size_t)) return;
404 a = (size_t *)(dso->base + start);
405 z = (size_t *)(dso->base + end);
407 a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
412 static void reclaim_gaps(struct dso *dso)
414 Phdr *ph = dso->phdr;
415 size_t phcnt = dso->phnum;
417 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
418 if (ph->p_type!=PT_LOAD) continue;
419 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
420 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
421 reclaim(dso, ph->p_vaddr+ph->p_memsz,
422 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
426 static void *map_library(int fd, struct dso *dso)
428 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
429 void *allocated_buf=0;
431 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
432 size_t this_min, this_max;
437 unsigned char *map=MAP_FAILED, *base;
442 ssize_t l = read(fd, buf, sizeof buf);
445 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
447 phsize = eh->e_phentsize * eh->e_phnum;
448 if (phsize > sizeof buf - sizeof *eh) {
449 allocated_buf = malloc(phsize);
450 if (!allocated_buf) return 0;
451 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
452 if (l < 0) goto error;
453 if (l != phsize) goto noexec;
454 ph = ph0 = allocated_buf;
455 } else if (eh->e_phoff + phsize > l) {
456 l = pread(fd, buf+1, phsize, eh->e_phoff);
457 if (l < 0) goto error;
458 if (l != phsize) goto noexec;
459 ph = ph0 = (void *)(buf + 1);
461 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
463 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
464 if (ph->p_type == PT_DYNAMIC) {
466 } else if (ph->p_type == PT_TLS) {
467 tls_image = ph->p_vaddr;
468 dso->tls_align = ph->p_align;
469 dso->tls_len = ph->p_filesz;
470 dso->tls_size = ph->p_memsz;
471 } else if (ph->p_type == PT_GNU_RELRO) {
472 dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
473 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
475 if (ph->p_type != PT_LOAD) continue;
476 if (ph->p_vaddr < addr_min) {
477 addr_min = ph->p_vaddr;
478 off_start = ph->p_offset;
479 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
480 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
481 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
483 if (ph->p_vaddr+ph->p_memsz > addr_max) {
484 addr_max = ph->p_vaddr+ph->p_memsz;
487 if (!dyn) goto noexec;
488 addr_max += PAGE_SIZE-1;
489 addr_max &= -PAGE_SIZE;
490 addr_min &= -PAGE_SIZE;
491 off_start &= -PAGE_SIZE;
492 map_len = addr_max - addr_min + off_start;
493 /* The first time, we map too much, possibly even more than
494 * the length of the file. This is okay because we will not
495 * use the invalid part; we just need to reserve the right
496 * amount of virtual address space to map over later. */
497 map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
498 if (map==MAP_FAILED) goto error;
499 /* If the loaded file is not relocatable and the requested address is
500 * not available, then the load operation must fail. */
501 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
505 base = map - addr_min;
508 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
509 if (ph->p_type != PT_LOAD) continue;
510 /* Check if the programs headers are in this load segment, and
511 * if so, record the address for use by dl_iterate_phdr. */
512 if (!dso->phdr && eh->e_phoff >= ph->p_offset
513 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
514 dso->phdr = (void *)(base + ph->p_vaddr
515 + (eh->e_phoff-ph->p_offset));
516 dso->phnum = eh->e_phnum;
517 dso->phentsize = eh->e_phentsize;
519 /* Reuse the existing mapping for the lowest-address LOAD */
520 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
521 this_min = ph->p_vaddr & -PAGE_SIZE;
522 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
523 off_start = ph->p_offset & -PAGE_SIZE;
524 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
525 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
526 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
527 if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
529 if (ph->p_memsz > ph->p_filesz) {
530 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
531 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
532 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
533 if (pgbrk-(size_t)base < this_max && mmap((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
537 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
538 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
539 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
544 dso->map_len = map_len;
546 dso->dynv = (void *)(base+dyn);
547 if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
548 if (!runtime) reclaim_gaps(dso);
554 if (map!=MAP_FAILED) munmap(map, map_len);
559 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
564 s += strspn(s, ":\n");
565 l = strcspn(s, ":\n");
566 if (l-1 >= INT_MAX) return -1;
567 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
568 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
576 /* Any negative value but -1 will inhibit
577 * futher path search. */
585 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
588 const char *s, *t, *origin;
590 if (p->rpath || !p->rpath_orig) return 0;
591 if (!strchr(p->rpath_orig, '$')) {
592 p->rpath = p->rpath_orig;
597 while ((t=strchr(s, '$'))) {
598 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
603 if (n > SSIZE_MAX/PATH_MAX) return 0;
605 if (p->kernel_mapped) {
606 /* $ORIGIN searches cannot be performed for the main program
607 * when it is suid/sgid/AT_SECURE. This is because the
608 * pathname is under the control of the caller of execve.
609 * For libraries, however, $ORIGIN can be processed safely
610 * since the library's pathname came from a trusted source
611 * (either system paths or a call to dlopen). */
614 l = readlink("/proc/self/exe", buf, buf_size);
615 if (l == -1) switch (errno) {
630 t = strrchr(origin, '/');
631 l = t ? t-origin : 0;
632 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
633 if (!p->rpath) return -1;
637 while ((t=strchr(s, '$'))) {
640 memcpy(d, origin, l);
642 /* It was determined previously that the '$' is followed
643 * either by "ORIGIN" or "{ORIGIN}". */
644 s = t + 7 + 2*(t[1]=='{');
650 static void decode_dyn(struct dso *p)
653 decode_vec(p->dynv, dyn, DYN_CNT);
654 p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
655 p->strings = (void *)(p->base + dyn[DT_STRTAB]);
656 if (dyn[0]&(1<<DT_HASH))
657 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
658 if (dyn[0]&(1<<DT_RPATH))
659 p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
660 if (dyn[0]&(1<<DT_RUNPATH))
661 p->rpath_orig = (void *)(p->strings + dyn[DT_RUNPATH]);
662 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
663 p->ghashtab = (void *)(p->base + *dyn);
664 if (search_vec(p->dynv, dyn, DT_VERSYM))
665 p->versym = (void *)(p->base + *dyn);
668 static struct dso *load_library(const char *name, struct dso *needed_by)
670 char buf[2*NAME_MAX+2];
671 const char *pathname;
673 struct dso *p, temp_dso = {0};
685 /* Catch and block attempts to reload the implementation itself */
686 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
687 static const char *rp, reserved[] =
688 "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
689 char *z = strchr(name, '.');
692 for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
695 /* Track which names have been resolved
696 * and only report each one once. */
697 static unsigned reported;
698 unsigned mask = 1U<<(rp-reserved);
699 if (!(reported & mask)) {
701 dprintf(1, "\t%s => %s (%p)\n",
710 if (!strcmp(name, ldso.name)) is_self = 1;
715 tail = ldso.next ? ldso.next : &ldso;
719 if (strchr(name, '/')) {
721 fd = open(name, O_RDONLY|O_CLOEXEC);
723 /* Search for the name to see if it's already loaded */
724 for (p=head->next; p; p=p->next) {
725 if (p->shortname && !strcmp(p->shortname, name)) {
730 if (strlen(name) > NAME_MAX) return 0;
732 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
733 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
734 if (fixup_rpath(p, buf, sizeof buf) < 0)
735 fd = -2; /* Inhibit further search. */
737 fd = path_open(name, p->rpath, buf, sizeof buf);
743 if (ldso.name[0]=='/') {
745 for (s=t=z=ldso.name; *s; s++)
746 if (*s=='/') z=t, t=s;
747 prefix_len = z-ldso.name;
748 if (prefix_len < PATH_MAX)
755 char etc_ldso_path[prefix_len + 1
756 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
757 snprintf(etc_ldso_path, sizeof etc_ldso_path,
758 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
759 (int)prefix_len, prefix);
760 FILE *f = fopen(etc_ldso_path, "rbe");
762 if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
767 } else if (errno != ENOENT) {
771 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
772 fd = path_open(name, sys_path, buf, sizeof buf);
776 if (fd < 0) return 0;
777 if (fstat(fd, &st) < 0) {
781 for (p=head->next; p; p=p->next) {
782 if (p->dev == st.st_dev && p->ino == st.st_ino) {
783 /* If this library was previously loaded with a
784 * pathname but a search found the same inode,
785 * setup its shortname so it can be found by name. */
786 if (!p->shortname && pathname != name)
787 p->shortname = strrchr(p->name, '/')+1;
793 map = noload ? 0 : map_library(fd, &temp_dso);
797 /* Allocate storage for the new DSO. When there is TLS, this
798 * storage must include a reservation for all pre-existing
799 * threads to obtain copies of both the new TLS, and an
800 * extended DTV capable of storing an additional slot for
801 * the newly-loaded DSO. */
802 alloc_size = sizeof *p + strlen(pathname) + 1;
803 if (runtime && temp_dso.tls_image) {
804 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
805 + sizeof(void *) * (tls_cnt+3);
806 n_th = libc.threads_minus_1 + 1;
807 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
808 else alloc_size += n_th * per_th;
810 p = calloc(1, alloc_size);
812 munmap(map, temp_dso.map_len);
815 memcpy(p, &temp_dso, sizeof temp_dso);
820 p->needed_by = needed_by;
822 strcpy(p->name, pathname);
823 /* Add a shortname only if name arg was not an explicit pathname. */
824 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
826 p->tls_id = ++tls_cnt;
827 tls_align = MAXP2(tls_align, p->tls_align);
829 p->tls_offset = tls_offset + ( (tls_align-1) &
830 -(tls_offset + (uintptr_t)p->tls_image) );
831 tls_offset += p->tls_size;
833 tls_offset += p->tls_size + p->tls_align - 1;
834 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
836 p->tls_offset = tls_offset;
838 p->new_dtv = (void *)(-sizeof(size_t) &
839 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
840 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
847 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
852 static void load_deps(struct dso *p)
855 struct dso ***deps = &p->deps, **tmp, *dep;
856 for (; p; p=p->next) {
857 for (i=0; p->dynv[i]; i+=2) {
858 if (p->dynv[i] != DT_NEEDED) continue;
859 dep = load_library(p->strings + p->dynv[i+1], p);
861 error("Error loading shared library %s: %m (needed by %s)",
862 p->strings + p->dynv[i+1], p->name);
863 if (runtime) longjmp(*rtld_fail, 1);
867 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
868 if (!tmp) longjmp(*rtld_fail, 1);
877 static void load_preload(char *s)
882 for ( ; *s && (isspace(*s) || *s==':'); s++);
883 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
891 static void make_global(struct dso *p)
893 for (; p; p=p->next) p->global = 1;
896 static void do_mips_relocs(struct dso *p, size_t *got)
899 unsigned char *base = p->base;
900 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
904 while (i--) *got++ += (size_t)base;
906 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
907 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
908 Sym *sym = p->syms + j;
909 rel[0] = (unsigned char *)got - base;
910 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
911 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
912 do_relocs(p, rel, sizeof rel, 2);
916 static void reloc_all(struct dso *p)
919 for (; p; p=p->next) {
920 if (p->relocated) continue;
921 decode_vec(p->dynv, dyn, DYN_CNT);
922 if (NEED_MIPS_GOT_RELOCS)
923 do_mips_relocs(p, (void *)(p->base+dyn[DT_PLTGOT]));
924 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
925 2+(dyn[DT_PLTREL]==DT_RELA));
926 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
927 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
929 if (head != &ldso && p->relro_start != p->relro_end &&
930 mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
931 error("Error relocating %s: RELRO protection failed: %m",
933 if (runtime) longjmp(*rtld_fail, 1);
940 static void kernel_mapped_dso(struct dso *p)
942 size_t min_addr = -1, max_addr = 0, cnt;
944 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
945 if (ph->p_type == PT_DYNAMIC) {
946 p->dynv = (void *)(p->base + ph->p_vaddr);
947 } else if (ph->p_type == PT_GNU_RELRO) {
948 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
949 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
951 if (ph->p_type != PT_LOAD) continue;
952 if (ph->p_vaddr < min_addr)
953 min_addr = ph->p_vaddr;
954 if (ph->p_vaddr+ph->p_memsz > max_addr)
955 max_addr = ph->p_vaddr+ph->p_memsz;
957 min_addr &= -PAGE_SIZE;
958 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
959 p->map = p->base + min_addr;
960 p->map_len = max_addr - min_addr;
961 p->kernel_mapped = 1;
964 static void do_fini()
968 for (p=fini_head; p; p=p->fini_next) {
969 if (!p->constructed) continue;
970 decode_vec(p->dynv, dyn, DYN_CNT);
971 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
972 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
973 size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
974 while (n--) ((void (*)(void))*--fn)();
976 #ifndef NO_LEGACY_INITFINI
977 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
978 ((void (*)(void))(p->base + dyn[DT_FINI]))();
983 static void do_init_fini(struct dso *p)
986 int need_locking = libc.threads_minus_1;
987 /* Allow recursive calls that arise when a library calls
988 * dlopen from one of its constructors, but block any
989 * other threads until all ctors have finished. */
990 if (need_locking) pthread_mutex_lock(&init_fini_lock);
991 for (; p; p=p->prev) {
992 if (p->constructed) continue;
994 decode_vec(p->dynv, dyn, DYN_CNT);
995 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
996 p->fini_next = fini_head;
999 #ifndef NO_LEGACY_INITFINI
1000 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1001 ((void (*)(void))(p->base + dyn[DT_INIT]))();
1003 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1004 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1005 size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
1006 while (n--) ((void (*)(void))*fn++)();
1008 if (!need_locking && libc.threads_minus_1) {
1010 pthread_mutex_lock(&init_fini_lock);
1013 if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1016 static void dl_debug_state(void)
1020 weak_alias(dl_debug_state, _dl_debug_state);
1024 pthread_t self = __pthread_self();
1026 for (p=head; p; p=p->next) {
1027 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
1028 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
1029 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
1030 p->tls_size - p->tls_len);
1031 if (p->tls_id == (size_t)self->dtv[0]) break;
1035 void *__copy_tls(unsigned char *mem)
1042 dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1);
1044 mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1045 td = (pthread_t)mem;
1046 mem += sizeof(struct pthread);
1048 for (p=head; p; p=p->next) {
1049 if (!p->tls_id) continue;
1050 dtv[p->tls_id] = mem + p->tls_offset;
1051 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1056 mem += libc.tls_size - sizeof(struct pthread);
1057 mem -= (uintptr_t)mem & (tls_align-1);
1058 td = (pthread_t)mem;
1060 for (p=head; p; p=p->next) {
1061 if (!p->tls_id) continue;
1062 dtv[p->tls_id] = mem - p->tls_offset;
1063 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1066 dtv[0] = (void *)tls_cnt;
1067 td->dtv = td->dtv_copy = dtv;
1071 __attribute__((__visibility__("hidden")))
1072 void *__tls_get_new(size_t *v)
1074 pthread_t self = __pthread_self();
1076 /* Block signals to make accessing new TLS async-signal-safe */
1078 __block_all_sigs(&set);
1079 if (v[0]<=(size_t)self->dtv[0]) {
1080 __restore_sigs(&set);
1081 return (char *)self->dtv[v[0]]+v[1];
1084 /* This is safe without any locks held because, if the caller
1085 * is able to request the Nth entry of the DTV, the DSO list
1086 * must be valid at least that far out and it was synchronized
1087 * at program startup or by an already-completed call to dlopen. */
1089 for (p=head; p->tls_id != v[0]; p=p->next);
1091 /* Get new DTV space from new DSO if needed */
1092 if (v[0] > (size_t)self->dtv[0]) {
1093 void **newdtv = p->new_dtv +
1094 (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
1095 memcpy(newdtv, self->dtv,
1096 ((size_t)self->dtv[0]+1) * sizeof(void *));
1097 newdtv[0] = (void *)v[0];
1098 self->dtv = self->dtv_copy = newdtv;
1101 /* Get new TLS memory from all new DSOs up to the requested one */
1103 for (p=head; ; p=p->next) {
1104 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1105 mem = p->new_tls + (p->tls_size + p->tls_align)
1106 * a_fetch_add(&p->new_tls_idx,1);
1107 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1109 self->dtv[p->tls_id] = mem;
1110 memcpy(mem, p->tls_image, p->tls_len);
1111 if (p->tls_id == v[0]) break;
1113 __restore_sigs(&set);
1117 static void update_tls_size()
1119 libc.tls_size = ALIGN(
1120 (1+tls_cnt) * sizeof(void *) +
1122 sizeof(struct pthread) +
1127 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1128 * following stage 2 and stage 3 functions via primitive symbolic lookup
1129 * since it does not have access to their addresses to begin with. */
1131 /* Stage 2 of the dynamic linker is called after relative relocations
1132 * have been processed. It can make function calls to static functions
1133 * and access string literals and static data, but cannot use extern
1134 * symbols. Its job is to perform symbolic relocations on the dynamic
1135 * linker itself, but some of the relocations performed may need to be
1136 * replaced later due to copy relocations in the main program. */
1138 void __dls2(unsigned char *base, size_t *sp)
1140 Ehdr *ehdr = (void *)base;
1142 ldso.name = ldso.shortname = "libc.so";
1144 ldso.phnum = ehdr->e_phnum;
1145 ldso.phdr = (void *)(base + ehdr->e_phoff);
1146 ldso.phentsize = ehdr->e_phentsize;
1147 kernel_mapped_dso(&ldso);
1150 /* Prepare storage for to save clobbered REL addends so they
1151 * can be reused in stage 3. There should be very few. If
1152 * something goes wrong and there are a huge number, abort
1153 * instead of risking stack overflow. */
1154 size_t dyn[DYN_CNT];
1155 decode_vec(ldso.dynv, dyn, DYN_CNT);
1156 size_t *rel = (void *)(base+dyn[DT_REL]);
1157 size_t rel_size = dyn[DT_RELSZ];
1158 size_t symbolic_rel_cnt = 0;
1159 apply_addends_to = rel;
1160 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1161 if (!IS_RELATIVE(rel[1])) symbolic_rel_cnt++;
1162 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1163 size_t addends[symbolic_rel_cnt+1];
1164 saved_addends = addends;
1171 /* Call dynamic linker stage-3, __dls3, looking it up
1172 * symbolically as a barrier against moving the address
1173 * load across the above relocation processing. */
1174 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1175 ((stage3_func)(ldso.base+dls3_def.sym->st_value))(sp);
1178 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1179 * fully functional. Its job is to load (if not already loaded) and
1180 * process dependencies and relocations for the main application and
1181 * transfer control to its entry point. */
1183 _Noreturn void __dls3(size_t *sp)
1185 static struct dso app, vdso;
1186 size_t aux[AUX_CNT], *auxv;
1188 char *env_preload=0;
1191 char **argv = (void *)(sp+1);
1192 char **argv_orig = argv;
1193 char **envp = argv+argc+1;
1195 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1196 * use during dynamic linking. If possible it will also serve as the
1197 * thread pointer at runtime. */
1198 libc.tls_size = sizeof builtin_tls;
1199 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1203 /* Find aux vector just past environ[] */
1204 for (i=argc+1; argv[i]; i++)
1205 if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
1206 env_path = argv[i]+16;
1207 else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
1208 env_preload = argv[i]+11;
1209 auxv = (void *)(argv+i+1);
1211 decode_vec(auxv, aux, AUX_CNT);
1213 /* Only trust user/env if kernel says we're not suid/sgid */
1214 if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1215 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
1220 libc.page_size = aux[AT_PAGESZ];
1223 /* If the main program was already loaded by the kernel,
1224 * AT_PHDR will point to some location other than the dynamic
1225 * linker's program headers. */
1226 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1227 size_t interp_off = 0;
1228 size_t tls_image = 0;
1229 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1230 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1231 app.phnum = aux[AT_PHNUM];
1232 app.phentsize = aux[AT_PHENT];
1233 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1234 if (phdr->p_type == PT_PHDR)
1235 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1236 else if (phdr->p_type == PT_INTERP)
1237 interp_off = (size_t)phdr->p_vaddr;
1238 else if (phdr->p_type == PT_TLS) {
1239 tls_image = phdr->p_vaddr;
1240 app.tls_len = phdr->p_filesz;
1241 app.tls_size = phdr->p_memsz;
1242 app.tls_align = phdr->p_align;
1245 if (app.tls_size) app.tls_image = (char *)app.base + tls_image;
1246 if (interp_off) ldso.name = (char *)app.base + interp_off;
1247 if ((aux[0] & (1UL<<AT_EXECFN))
1248 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1249 app.name = (char *)aux[AT_EXECFN];
1252 kernel_mapped_dso(&app);
1255 char *ldname = argv[0];
1256 size_t l = strlen(ldname);
1257 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1259 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1260 char *opt = argv[0]+2;
1261 *argv++ = (void *)-1;
1264 } else if (!memcmp(opt, "list", 5)) {
1266 } else if (!memcmp(opt, "library-path", 12)) {
1267 if (opt[12]=='=') env_path = opt+13;
1268 else if (opt[12]) *argv = 0;
1269 else if (*argv) env_path = *argv++;
1270 } else if (!memcmp(opt, "preload", 7)) {
1271 if (opt[7]=='=') env_preload = opt+8;
1272 else if (opt[7]) *argv = 0;
1273 else if (*argv) env_preload = *argv++;
1278 argv[-1] = (void *)(argc - (argv-argv_orig));
1280 dprintf(2, "musl libc\n"
1282 "Dynamic Program Loader\n"
1283 "Usage: %s [options] [--] pathname%s\n",
1284 __libc_get_version(), ldname,
1285 ldd_mode ? "" : " [args]");
1288 fd = open(argv[0], O_RDONLY);
1290 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1294 Ehdr *ehdr = (void *)map_library(fd, &app);
1296 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1303 aux[AT_ENTRY] = (size_t)app.base + ehdr->e_entry;
1304 /* Find the name that would have been used for the dynamic
1305 * linker had ldd not taken its place. */
1307 for (i=0; i<app.phnum; i++) {
1308 if (app.phdr[i].p_type == PT_INTERP)
1309 ldso.name = (void *)(app.base
1310 + app.phdr[i].p_vaddr);
1312 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1316 app.tls_id = tls_cnt = 1;
1319 tls_offset = app.tls_size
1320 + ( -((uintptr_t)app.tls_image + app.tls_size)
1321 & (app.tls_align-1) );
1323 tls_offset = app.tls_offset = app.tls_size
1324 + ( -((uintptr_t)app.tls_image + app.tls_size)
1325 & (app.tls_align-1) );
1327 tls_align = MAXP2(tls_align, app.tls_align);
1332 /* Attach to vdso, if provided by the kernel */
1333 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1334 Ehdr *ehdr = (void *)vdso_base;
1335 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1336 vdso.phnum = ehdr->e_phnum;
1337 vdso.phentsize = ehdr->e_phentsize;
1338 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1339 if (phdr->p_type == PT_DYNAMIC)
1340 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1341 if (phdr->p_type == PT_LOAD)
1342 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1345 vdso.shortname = "linux-gate.so.1";
1353 /* Initial dso chain consists only of the app. */
1356 /* Donate unused parts of app and library mapping to malloc */
1358 reclaim_gaps(&ldso);
1360 /* Load preload/needed libraries, add their symbols to the global
1361 * namespace, and perform all remaining relocations. */
1362 if (env_preload) load_preload(env_preload);
1366 #ifndef DYNAMIC_IS_RO
1367 for (i=0; app.dynv[i]; i+=2)
1368 if (app.dynv[i]==DT_DEBUG)
1369 app.dynv[i+1] = (size_t)&debug;
1372 /* The main program must be relocated LAST since it may contin
1373 * copy relocations which depend on libraries' relocations. */
1374 reloc_all(app.next);
1378 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1379 void *initial_tls = calloc(libc.tls_size, 1);
1381 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1382 argv[0], libc.tls_size);
1385 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1389 size_t tmp_tls_size = libc.tls_size;
1390 pthread_t self = __pthread_self();
1391 /* Temporarily set the tls size to the full size of
1392 * builtin_tls so that __copy_tls will use the same layout
1393 * as it did for before. Then check, just to be safe. */
1394 libc.tls_size = sizeof builtin_tls;
1395 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1396 libc.tls_size = tmp_tls_size;
1398 static_tls_cnt = tls_cnt;
1400 if (ldso_fail) _exit(127);
1401 if (ldd_mode) _exit(0);
1403 /* Switch to runtime mode: any further failures in the dynamic
1404 * linker are a reportable failure rather than a fatal startup
1409 debug.bp = dl_debug_state;
1411 debug.base = ldso.base;
1415 __init_libc(envp, argv[0]);
1420 CRTJMP((void *)aux[AT_ENTRY], argv-1);
1424 void *dlopen(const char *file, int mode)
1426 struct dso *volatile p, *orig_tail, *next;
1427 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1432 if (!file) return head;
1434 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1435 pthread_rwlock_wrlock(&lock);
1439 orig_tls_cnt = tls_cnt;
1440 orig_tls_offset = tls_offset;
1441 orig_tls_align = tls_align;
1443 noload = mode & RTLD_NOLOAD;
1446 if (setjmp(*rtld_fail)) {
1447 /* Clean up anything new that was (partially) loaded */
1448 if (p && p->deps) for (i=0; p->deps[i]; i++)
1449 if (p->deps[i]->global < 0)
1450 p->deps[i]->global = 0;
1451 for (p=orig_tail->next; p; p=next) {
1453 munmap(p->map, p->map_len);
1454 while (p->td_index) {
1455 void *tmp = p->td_index->next;
1459 if (p->rpath != p->rpath_orig)
1464 tls_cnt = orig_tls_cnt;
1465 tls_offset = orig_tls_offset;
1466 tls_align = orig_tls_align;
1471 } else p = load_library(file, head);
1475 "Library %s is not already loaded" :
1476 "Error loading shared library %s: %m",
1481 /* First load handling */
1484 if (p->deps) for (i=0; p->deps[i]; i++)
1485 if (!p->deps[i]->global)
1486 p->deps[i]->global = -1;
1487 if (!p->global) p->global = -1;
1489 if (p->deps) for (i=0; p->deps[i]; i++)
1490 if (p->deps[i]->global < 0)
1491 p->deps[i]->global = 0;
1492 if (p->global < 0) p->global = 0;
1495 if (mode & RTLD_GLOBAL) {
1496 if (p->deps) for (i=0; p->deps[i]; i++)
1497 p->deps[i]->global = 1;
1507 pthread_rwlock_unlock(&lock);
1508 if (p) do_init_fini(orig_tail);
1509 pthread_setcancelstate(cs, 0);
1513 static int invalid_dso_handle(void *h)
1516 for (p=head; p; p=p->next) if (h==p) return 0;
1517 error("Invalid library handle %p", (void *)h);
1521 void *__tls_get_addr(size_t *);
1523 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1526 uint32_t h = 0, gh = 0;
1528 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1529 if (p == RTLD_DEFAULT) {
1531 } else if (p == RTLD_NEXT) {
1532 for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1536 struct symdef def = find_sym(p, s, 0);
1537 if (!def.sym) goto failed;
1538 if ((def.sym->st_info&0xf) == STT_TLS)
1539 return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1540 return def.dso->base + def.sym->st_value;
1542 if (invalid_dso_handle(p))
1546 sym = gnu_lookup(s, gh, p);
1549 sym = sysv_lookup(s, h, p);
1551 if (sym && (sym->st_info&0xf) == STT_TLS)
1552 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1553 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1554 return p->base + sym->st_value;
1555 if (p->deps) for (i=0; p->deps[i]; i++) {
1556 if (p->deps[i]->ghashtab) {
1557 if (!gh) gh = gnu_hash(s);
1558 sym = gnu_lookup(s, gh, p->deps[i]);
1560 if (!h) h = sysv_hash(s);
1561 sym = sysv_lookup(s, h, p->deps[i]);
1563 if (sym && (sym->st_info&0xf) == STT_TLS)
1564 return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1565 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1566 return p->deps[i]->base + sym->st_value;
1569 error("Symbol not found: %s", s);
1573 int __dladdr(const void *addr, Dl_info *info)
1583 pthread_rwlock_rdlock(&lock);
1584 for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1585 pthread_rwlock_unlock(&lock);
1590 strings = p->strings;
1592 nsym = p->hashtab[1];
1596 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1597 sym += p->ghashtab[1];
1598 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1599 if (buckets[i] > nsym)
1603 nsym -= p->ghashtab[1];
1604 hashval = buckets + p->ghashtab[0] + nsym;
1606 while (!(*hashval++ & 1));
1610 for (; nsym; nsym--, sym++) {
1612 && (1<<(sym->st_info&0xf) & OK_TYPES)
1613 && (1<<(sym->st_info>>4) & OK_BINDS)) {
1614 void *symaddr = p->base + sym->st_value;
1615 if (symaddr > addr || symaddr < best)
1618 bestname = strings + sym->st_name;
1619 if (addr == symaddr)
1624 if (!best) return 0;
1626 info->dli_fname = p->name;
1627 info->dli_fbase = p->base;
1628 info->dli_sname = bestname;
1629 info->dli_saddr = best;
1634 __attribute__((__visibility__("hidden")))
1635 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1638 pthread_rwlock_rdlock(&lock);
1639 res = do_dlsym(p, s, ra);
1640 pthread_rwlock_unlock(&lock);
1644 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1646 struct dso *current;
1647 struct dl_phdr_info info;
1649 for(current = head; current;) {
1650 info.dlpi_addr = (uintptr_t)current->base;
1651 info.dlpi_name = current->name;
1652 info.dlpi_phdr = current->phdr;
1653 info.dlpi_phnum = current->phnum;
1654 info.dlpi_adds = gencnt;
1656 info.dlpi_tls_modid = current->tls_id;
1657 info.dlpi_tls_data = current->tls_image;
1659 ret = (callback)(&info, sizeof (info), data);
1661 if (ret != 0) break;
1663 pthread_rwlock_rdlock(&lock);
1664 current = current->next;
1665 pthread_rwlock_unlock(&lock);
1670 static int invalid_dso_handle(void *h)
1672 error("Invalid library handle %p", (void *)h);
1675 void *dlopen(const char *file, int mode)
1677 error("Dynamic loading not supported");
1680 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1682 error("Symbol not found: %s", s);
1685 int __dladdr (const void *addr, Dl_info *info)
1691 int __dlinfo(void *dso, int req, void *res)
1693 if (invalid_dso_handle(dso)) return -1;
1694 if (req != RTLD_DI_LINKMAP) {
1695 error("Unsupported request %d", req);
1698 *(struct link_map **)res = dso;
1704 pthread_t self = __pthread_self();
1705 if (!self->dlerror_flag) return 0;
1706 self->dlerror_flag = 0;
1707 char *s = self->dlerror_buf;
1708 if (s == (void *)-1)
1709 return "Dynamic linker failed to allocate memory for error message";
1714 int dlclose(void *p)
1716 return invalid_dso_handle(p);
1719 void __dl_thread_cleanup(void)
1721 pthread_t self = __pthread_self();
1722 if (self->dlerror_buf != (void *)-1)
1723 free(self->dlerror_buf);
1726 static void error(const char *fmt, ...)
1732 vdprintf(2, fmt, ap);
1739 pthread_t self = __pthread_self();
1740 if (self->dlerror_buf != (void *)-1)
1741 free(self->dlerror_buf);
1742 size_t len = vsnprintf(0, 0, fmt, ap);
1744 char *buf = malloc(len+1);
1747 vsnprintf(buf, len+1, fmt, ap);
1752 self->dlerror_buf = buf;
1753 self->dlerror_flag = 1;