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)
545 dso->map_len = map_len;
547 dso->dynv = (void *)(base+dyn);
548 if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
549 if (!runtime) reclaim_gaps(dso);
555 if (map!=MAP_FAILED) munmap(map, map_len);
560 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
565 s += strspn(s, ":\n");
566 l = strcspn(s, ":\n");
567 if (l-1 >= INT_MAX) return -1;
568 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
569 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
577 /* Any negative value but -1 will inhibit
578 * futher path search. */
586 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
589 const char *s, *t, *origin;
591 if (p->rpath || !p->rpath_orig) return 0;
592 if (!strchr(p->rpath_orig, '$')) {
593 p->rpath = p->rpath_orig;
598 while ((t=strchr(s, '$'))) {
599 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
604 if (n > SSIZE_MAX/PATH_MAX) return 0;
606 if (p->kernel_mapped) {
607 /* $ORIGIN searches cannot be performed for the main program
608 * when it is suid/sgid/AT_SECURE. This is because the
609 * pathname is under the control of the caller of execve.
610 * For libraries, however, $ORIGIN can be processed safely
611 * since the library's pathname came from a trusted source
612 * (either system paths or a call to dlopen). */
615 l = readlink("/proc/self/exe", buf, buf_size);
616 if (l == -1) switch (errno) {
631 t = strrchr(origin, '/');
632 l = t ? t-origin : 0;
633 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
634 if (!p->rpath) return -1;
638 while ((t=strchr(s, '$'))) {
641 memcpy(d, origin, l);
643 /* It was determined previously that the '$' is followed
644 * either by "ORIGIN" or "{ORIGIN}". */
645 s = t + 7 + 2*(t[1]=='{');
651 static void decode_dyn(struct dso *p)
654 decode_vec(p->dynv, dyn, DYN_CNT);
655 p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
656 p->strings = (void *)(p->base + dyn[DT_STRTAB]);
657 if (dyn[0]&(1<<DT_HASH))
658 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
659 if (dyn[0]&(1<<DT_RPATH))
660 p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
661 if (dyn[0]&(1<<DT_RUNPATH))
662 p->rpath_orig = (void *)(p->strings + dyn[DT_RUNPATH]);
663 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
664 p->ghashtab = (void *)(p->base + *dyn);
665 if (search_vec(p->dynv, dyn, DT_VERSYM))
666 p->versym = (void *)(p->base + *dyn);
669 static struct dso *load_library(const char *name, struct dso *needed_by)
671 char buf[2*NAME_MAX+2];
672 const char *pathname;
674 struct dso *p, temp_dso = {0};
686 /* Catch and block attempts to reload the implementation itself */
687 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
688 static const char *rp, reserved[] =
689 "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
690 char *z = strchr(name, '.');
693 for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
696 /* Track which names have been resolved
697 * and only report each one once. */
698 static unsigned reported;
699 unsigned mask = 1U<<(rp-reserved);
700 if (!(reported & mask)) {
702 dprintf(1, "\t%s => %s (%p)\n",
711 if (!strcmp(name, ldso.name)) is_self = 1;
716 tail = ldso.next ? ldso.next : &ldso;
720 if (strchr(name, '/')) {
722 fd = open(name, O_RDONLY|O_CLOEXEC);
724 /* Search for the name to see if it's already loaded */
725 for (p=head->next; p; p=p->next) {
726 if (p->shortname && !strcmp(p->shortname, name)) {
731 if (strlen(name) > NAME_MAX) return 0;
733 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
734 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
735 if (fixup_rpath(p, buf, sizeof buf) < 0)
736 fd = -2; /* Inhibit further search. */
738 fd = path_open(name, p->rpath, buf, sizeof buf);
744 if (ldso.name[0]=='/') {
746 for (s=t=z=ldso.name; *s; s++)
747 if (*s=='/') z=t, t=s;
748 prefix_len = z-ldso.name;
749 if (prefix_len < PATH_MAX)
756 char etc_ldso_path[prefix_len + 1
757 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
758 snprintf(etc_ldso_path, sizeof etc_ldso_path,
759 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
760 (int)prefix_len, prefix);
761 FILE *f = fopen(etc_ldso_path, "rbe");
763 if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
768 } else if (errno != ENOENT) {
772 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
773 fd = path_open(name, sys_path, buf, sizeof buf);
777 if (fd < 0) return 0;
778 if (fstat(fd, &st) < 0) {
782 for (p=head->next; p; p=p->next) {
783 if (p->dev == st.st_dev && p->ino == st.st_ino) {
784 /* If this library was previously loaded with a
785 * pathname but a search found the same inode,
786 * setup its shortname so it can be found by name. */
787 if (!p->shortname && pathname != name)
788 p->shortname = strrchr(p->name, '/')+1;
794 map = noload ? 0 : map_library(fd, &temp_dso);
798 /* Allocate storage for the new DSO. When there is TLS, this
799 * storage must include a reservation for all pre-existing
800 * threads to obtain copies of both the new TLS, and an
801 * extended DTV capable of storing an additional slot for
802 * the newly-loaded DSO. */
803 alloc_size = sizeof *p + strlen(pathname) + 1;
804 if (runtime && temp_dso.tls_image) {
805 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
806 + sizeof(void *) * (tls_cnt+3);
807 n_th = libc.threads_minus_1 + 1;
808 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
809 else alloc_size += n_th * per_th;
811 p = calloc(1, alloc_size);
813 munmap(map, temp_dso.map_len);
816 memcpy(p, &temp_dso, sizeof temp_dso);
821 p->needed_by = needed_by;
823 strcpy(p->name, pathname);
824 /* Add a shortname only if name arg was not an explicit pathname. */
825 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
827 p->tls_id = ++tls_cnt;
828 tls_align = MAXP2(tls_align, p->tls_align);
830 p->tls_offset = tls_offset + ( (tls_align-1) &
831 -(tls_offset + (uintptr_t)p->tls_image) );
832 tls_offset += p->tls_size;
834 tls_offset += p->tls_size + p->tls_align - 1;
835 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
837 p->tls_offset = tls_offset;
839 p->new_dtv = (void *)(-sizeof(size_t) &
840 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
841 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
848 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
853 static void load_deps(struct dso *p)
856 struct dso ***deps = &p->deps, **tmp, *dep;
857 for (; p; p=p->next) {
858 for (i=0; p->dynv[i]; i+=2) {
859 if (p->dynv[i] != DT_NEEDED) continue;
860 dep = load_library(p->strings + p->dynv[i+1], p);
862 error("Error loading shared library %s: %m (needed by %s)",
863 p->strings + p->dynv[i+1], p->name);
864 if (runtime) longjmp(*rtld_fail, 1);
868 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
869 if (!tmp) longjmp(*rtld_fail, 1);
878 static void load_preload(char *s)
883 for ( ; *s && (isspace(*s) || *s==':'); s++);
884 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
892 static void make_global(struct dso *p)
894 for (; p; p=p->next) p->global = 1;
897 static void do_mips_relocs(struct dso *p, size_t *got)
900 unsigned char *base = p->base;
901 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
905 while (i--) *got++ += (size_t)base;
907 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
908 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
909 Sym *sym = p->syms + j;
910 rel[0] = (unsigned char *)got - base;
911 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
912 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
913 do_relocs(p, rel, sizeof rel, 2);
917 static void reloc_all(struct dso *p)
920 for (; p; p=p->next) {
921 if (p->relocated) continue;
922 decode_vec(p->dynv, dyn, DYN_CNT);
923 if (NEED_MIPS_GOT_RELOCS)
924 do_mips_relocs(p, (void *)(p->base+dyn[DT_PLTGOT]));
925 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
926 2+(dyn[DT_PLTREL]==DT_RELA));
927 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
928 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
930 if (head != &ldso && p->relro_start != p->relro_end &&
931 mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ)
932 && errno != ENOSYS) {
933 error("Error relocating %s: RELRO protection failed: %m",
935 if (runtime) longjmp(*rtld_fail, 1);
942 static void kernel_mapped_dso(struct dso *p)
944 size_t min_addr = -1, max_addr = 0, cnt;
946 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
947 if (ph->p_type == PT_DYNAMIC) {
948 p->dynv = (void *)(p->base + ph->p_vaddr);
949 } else if (ph->p_type == PT_GNU_RELRO) {
950 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
951 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
953 if (ph->p_type != PT_LOAD) continue;
954 if (ph->p_vaddr < min_addr)
955 min_addr = ph->p_vaddr;
956 if (ph->p_vaddr+ph->p_memsz > max_addr)
957 max_addr = ph->p_vaddr+ph->p_memsz;
959 min_addr &= -PAGE_SIZE;
960 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
961 p->map = p->base + min_addr;
962 p->map_len = max_addr - min_addr;
963 p->kernel_mapped = 1;
966 static void do_fini()
970 for (p=fini_head; p; p=p->fini_next) {
971 if (!p->constructed) continue;
972 decode_vec(p->dynv, dyn, DYN_CNT);
973 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
974 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
975 size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
976 while (n--) ((void (*)(void))*--fn)();
978 #ifndef NO_LEGACY_INITFINI
979 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
980 ((void (*)(void))(p->base + dyn[DT_FINI]))();
985 static void do_init_fini(struct dso *p)
988 int need_locking = libc.threads_minus_1;
989 /* Allow recursive calls that arise when a library calls
990 * dlopen from one of its constructors, but block any
991 * other threads until all ctors have finished. */
992 if (need_locking) pthread_mutex_lock(&init_fini_lock);
993 for (; p; p=p->prev) {
994 if (p->constructed) continue;
996 decode_vec(p->dynv, dyn, DYN_CNT);
997 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
998 p->fini_next = fini_head;
1001 #ifndef NO_LEGACY_INITFINI
1002 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1003 ((void (*)(void))(p->base + dyn[DT_INIT]))();
1005 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1006 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1007 size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
1008 while (n--) ((void (*)(void))*fn++)();
1010 if (!need_locking && libc.threads_minus_1) {
1012 pthread_mutex_lock(&init_fini_lock);
1015 if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1018 static void dl_debug_state(void)
1022 weak_alias(dl_debug_state, _dl_debug_state);
1026 pthread_t self = __pthread_self();
1028 for (p=head; p; p=p->next) {
1029 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
1030 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
1031 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
1032 p->tls_size - p->tls_len);
1033 if (p->tls_id == (size_t)self->dtv[0]) break;
1037 void *__copy_tls(unsigned char *mem)
1044 dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1);
1046 mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1047 td = (pthread_t)mem;
1048 mem += sizeof(struct pthread);
1050 for (p=head; p; p=p->next) {
1051 if (!p->tls_id) continue;
1052 dtv[p->tls_id] = mem + p->tls_offset;
1053 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1058 mem += libc.tls_size - sizeof(struct pthread);
1059 mem -= (uintptr_t)mem & (tls_align-1);
1060 td = (pthread_t)mem;
1062 for (p=head; p; p=p->next) {
1063 if (!p->tls_id) continue;
1064 dtv[p->tls_id] = mem - p->tls_offset;
1065 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1068 dtv[0] = (void *)tls_cnt;
1069 td->dtv = td->dtv_copy = dtv;
1073 __attribute__((__visibility__("hidden")))
1074 void *__tls_get_new(size_t *v)
1076 pthread_t self = __pthread_self();
1078 /* Block signals to make accessing new TLS async-signal-safe */
1080 __block_all_sigs(&set);
1081 if (v[0]<=(size_t)self->dtv[0]) {
1082 __restore_sigs(&set);
1083 return (char *)self->dtv[v[0]]+v[1];
1086 /* This is safe without any locks held because, if the caller
1087 * is able to request the Nth entry of the DTV, the DSO list
1088 * must be valid at least that far out and it was synchronized
1089 * at program startup or by an already-completed call to dlopen. */
1091 for (p=head; p->tls_id != v[0]; p=p->next);
1093 /* Get new DTV space from new DSO if needed */
1094 if (v[0] > (size_t)self->dtv[0]) {
1095 void **newdtv = p->new_dtv +
1096 (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
1097 memcpy(newdtv, self->dtv,
1098 ((size_t)self->dtv[0]+1) * sizeof(void *));
1099 newdtv[0] = (void *)v[0];
1100 self->dtv = self->dtv_copy = newdtv;
1103 /* Get new TLS memory from all new DSOs up to the requested one */
1105 for (p=head; ; p=p->next) {
1106 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1107 mem = p->new_tls + (p->tls_size + p->tls_align)
1108 * a_fetch_add(&p->new_tls_idx,1);
1109 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1111 self->dtv[p->tls_id] = mem;
1112 memcpy(mem, p->tls_image, p->tls_len);
1113 if (p->tls_id == v[0]) break;
1115 __restore_sigs(&set);
1119 static void update_tls_size()
1121 libc.tls_size = ALIGN(
1122 (1+tls_cnt) * sizeof(void *) +
1124 sizeof(struct pthread) +
1129 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1130 * following stage 2 and stage 3 functions via primitive symbolic lookup
1131 * since it does not have access to their addresses to begin with. */
1133 /* Stage 2 of the dynamic linker is called after relative relocations
1134 * have been processed. It can make function calls to static functions
1135 * and access string literals and static data, but cannot use extern
1136 * symbols. Its job is to perform symbolic relocations on the dynamic
1137 * linker itself, but some of the relocations performed may need to be
1138 * replaced later due to copy relocations in the main program. */
1140 void __dls2(unsigned char *base, size_t *sp)
1142 Ehdr *ehdr = (void *)base;
1144 ldso.name = ldso.shortname = "libc.so";
1146 ldso.phnum = ehdr->e_phnum;
1147 ldso.phdr = (void *)(base + ehdr->e_phoff);
1148 ldso.phentsize = ehdr->e_phentsize;
1149 kernel_mapped_dso(&ldso);
1152 /* Prepare storage for to save clobbered REL addends so they
1153 * can be reused in stage 3. There should be very few. If
1154 * something goes wrong and there are a huge number, abort
1155 * instead of risking stack overflow. */
1156 size_t dyn[DYN_CNT];
1157 decode_vec(ldso.dynv, dyn, DYN_CNT);
1158 size_t *rel = (void *)(base+dyn[DT_REL]);
1159 size_t rel_size = dyn[DT_RELSZ];
1160 size_t symbolic_rel_cnt = 0;
1161 apply_addends_to = rel;
1162 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1163 if (!IS_RELATIVE(rel[1])) symbolic_rel_cnt++;
1164 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1165 size_t addends[symbolic_rel_cnt+1];
1166 saved_addends = addends;
1173 /* Call dynamic linker stage-3, __dls3, looking it up
1174 * symbolically as a barrier against moving the address
1175 * load across the above relocation processing. */
1176 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1177 ((stage3_func)(ldso.base+dls3_def.sym->st_value))(sp);
1180 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1181 * fully functional. Its job is to load (if not already loaded) and
1182 * process dependencies and relocations for the main application and
1183 * transfer control to its entry point. */
1185 _Noreturn void __dls3(size_t *sp)
1187 static struct dso app, vdso;
1188 size_t aux[AUX_CNT], *auxv;
1190 char *env_preload=0;
1193 char **argv = (void *)(sp+1);
1194 char **argv_orig = argv;
1195 char **envp = argv+argc+1;
1197 /* Find aux vector just past environ[] and use it to initialize
1198 * global data that may be needed before we can make syscalls. */
1200 for (i=argc+1; argv[i]; i++);
1201 libc.auxv = auxv = (void *)(argv+i+1);
1202 decode_vec(auxv, aux, AUX_CNT);
1203 __hwcap = aux[AT_HWCAP];
1204 libc.page_size = aux[AT_PAGESZ];
1205 libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1206 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1208 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1209 * use during dynamic linking. If possible it will also serve as the
1210 * thread pointer at runtime. */
1211 libc.tls_size = sizeof builtin_tls;
1212 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1216 /* Only trust user/env if kernel says we're not suid/sgid */
1218 env_path = getenv("LD_LIBRARY_PATH");
1219 env_preload = getenv("LD_PRELOAD");
1222 /* If the main program was already loaded by the kernel,
1223 * AT_PHDR will point to some location other than the dynamic
1224 * linker's program headers. */
1225 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1226 size_t interp_off = 0;
1227 size_t tls_image = 0;
1228 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1229 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1230 app.phnum = aux[AT_PHNUM];
1231 app.phentsize = aux[AT_PHENT];
1232 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1233 if (phdr->p_type == PT_PHDR)
1234 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1235 else if (phdr->p_type == PT_INTERP)
1236 interp_off = (size_t)phdr->p_vaddr;
1237 else if (phdr->p_type == PT_TLS) {
1238 tls_image = phdr->p_vaddr;
1239 app.tls_len = phdr->p_filesz;
1240 app.tls_size = phdr->p_memsz;
1241 app.tls_align = phdr->p_align;
1244 if (app.tls_size) app.tls_image = (char *)app.base + tls_image;
1245 if (interp_off) ldso.name = (char *)app.base + interp_off;
1246 if ((aux[0] & (1UL<<AT_EXECFN))
1247 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1248 app.name = (char *)aux[AT_EXECFN];
1251 kernel_mapped_dso(&app);
1254 char *ldname = argv[0];
1255 size_t l = strlen(ldname);
1256 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1258 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1259 char *opt = argv[0]+2;
1260 *argv++ = (void *)-1;
1263 } else if (!memcmp(opt, "list", 5)) {
1265 } else if (!memcmp(opt, "library-path", 12)) {
1266 if (opt[12]=='=') env_path = opt+13;
1267 else if (opt[12]) *argv = 0;
1268 else if (*argv) env_path = *argv++;
1269 } else if (!memcmp(opt, "preload", 7)) {
1270 if (opt[7]=='=') env_preload = opt+8;
1271 else if (opt[7]) *argv = 0;
1272 else if (*argv) env_preload = *argv++;
1277 argv[-1] = (void *)(argc - (argv-argv_orig));
1279 dprintf(2, "musl libc\n"
1281 "Dynamic Program Loader\n"
1282 "Usage: %s [options] [--] pathname%s\n",
1283 __libc_get_version(), ldname,
1284 ldd_mode ? "" : " [args]");
1287 fd = open(argv[0], O_RDONLY);
1289 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1293 Ehdr *ehdr = (void *)map_library(fd, &app);
1295 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1302 aux[AT_ENTRY] = (size_t)app.base + ehdr->e_entry;
1303 /* Find the name that would have been used for the dynamic
1304 * linker had ldd not taken its place. */
1306 for (i=0; i<app.phnum; i++) {
1307 if (app.phdr[i].p_type == PT_INTERP)
1308 ldso.name = (void *)(app.base
1309 + app.phdr[i].p_vaddr);
1311 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1315 app.tls_id = tls_cnt = 1;
1318 tls_offset = app.tls_size
1319 + ( -((uintptr_t)app.tls_image + app.tls_size)
1320 & (app.tls_align-1) );
1322 tls_offset = app.tls_offset = app.tls_size
1323 + ( -((uintptr_t)app.tls_image + app.tls_size)
1324 & (app.tls_align-1) );
1326 tls_align = MAXP2(tls_align, app.tls_align);
1331 /* Attach to vdso, if provided by the kernel */
1332 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1333 Ehdr *ehdr = (void *)vdso_base;
1334 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1335 vdso.phnum = ehdr->e_phnum;
1336 vdso.phentsize = ehdr->e_phentsize;
1337 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1338 if (phdr->p_type == PT_DYNAMIC)
1339 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1340 if (phdr->p_type == PT_LOAD)
1341 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1344 vdso.shortname = "linux-gate.so.1";
1352 /* Initial dso chain consists only of the app. */
1355 /* Donate unused parts of app and library mapping to malloc */
1357 reclaim_gaps(&ldso);
1359 /* Load preload/needed libraries, add their symbols to the global
1360 * namespace, and perform all remaining relocations. */
1361 if (env_preload) load_preload(env_preload);
1365 #ifndef DYNAMIC_IS_RO
1366 for (i=0; app.dynv[i]; i+=2)
1367 if (app.dynv[i]==DT_DEBUG)
1368 app.dynv[i+1] = (size_t)&debug;
1371 /* The main program must be relocated LAST since it may contin
1372 * copy relocations which depend on libraries' relocations. */
1373 reloc_all(app.next);
1377 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1378 void *initial_tls = calloc(libc.tls_size, 1);
1380 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1381 argv[0], libc.tls_size);
1384 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1388 size_t tmp_tls_size = libc.tls_size;
1389 pthread_t self = __pthread_self();
1390 /* Temporarily set the tls size to the full size of
1391 * builtin_tls so that __copy_tls will use the same layout
1392 * as it did for before. Then check, just to be safe. */
1393 libc.tls_size = sizeof builtin_tls;
1394 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1395 libc.tls_size = tmp_tls_size;
1397 static_tls_cnt = tls_cnt;
1399 if (ldso_fail) _exit(127);
1400 if (ldd_mode) _exit(0);
1402 /* Switch to runtime mode: any further failures in the dynamic
1403 * linker are a reportable failure rather than a fatal startup
1408 debug.bp = dl_debug_state;
1410 debug.base = ldso.base;
1414 __init_libc(envp, argv[0]);
1419 CRTJMP((void *)aux[AT_ENTRY], argv-1);
1423 void *dlopen(const char *file, int mode)
1425 struct dso *volatile p, *orig_tail, *next;
1426 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1431 if (!file) return head;
1433 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1434 pthread_rwlock_wrlock(&lock);
1438 orig_tls_cnt = tls_cnt;
1439 orig_tls_offset = tls_offset;
1440 orig_tls_align = tls_align;
1442 noload = mode & RTLD_NOLOAD;
1445 if (setjmp(*rtld_fail)) {
1446 /* Clean up anything new that was (partially) loaded */
1447 if (p && p->deps) for (i=0; p->deps[i]; i++)
1448 if (p->deps[i]->global < 0)
1449 p->deps[i]->global = 0;
1450 for (p=orig_tail->next; p; p=next) {
1452 munmap(p->map, p->map_len);
1453 while (p->td_index) {
1454 void *tmp = p->td_index->next;
1458 if (p->rpath != p->rpath_orig)
1463 tls_cnt = orig_tls_cnt;
1464 tls_offset = orig_tls_offset;
1465 tls_align = orig_tls_align;
1470 } else p = load_library(file, head);
1474 "Library %s is not already loaded" :
1475 "Error loading shared library %s: %m",
1480 /* First load handling */
1483 if (p->deps) for (i=0; p->deps[i]; i++)
1484 if (!p->deps[i]->global)
1485 p->deps[i]->global = -1;
1486 if (!p->global) p->global = -1;
1488 if (p->deps) for (i=0; p->deps[i]; i++)
1489 if (p->deps[i]->global < 0)
1490 p->deps[i]->global = 0;
1491 if (p->global < 0) p->global = 0;
1494 if (mode & RTLD_GLOBAL) {
1495 if (p->deps) for (i=0; p->deps[i]; i++)
1496 p->deps[i]->global = 1;
1506 pthread_rwlock_unlock(&lock);
1507 if (p) do_init_fini(orig_tail);
1508 pthread_setcancelstate(cs, 0);
1512 static int invalid_dso_handle(void *h)
1515 for (p=head; p; p=p->next) if (h==p) return 0;
1516 error("Invalid library handle %p", (void *)h);
1520 void *__tls_get_addr(size_t *);
1522 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1525 uint32_t h = 0, gh = 0;
1527 if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1528 if (p == RTLD_DEFAULT) {
1530 } else if (p == RTLD_NEXT) {
1531 for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1535 struct symdef def = find_sym(p, s, 0);
1536 if (!def.sym) goto failed;
1537 if ((def.sym->st_info&0xf) == STT_TLS)
1538 return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1539 return def.dso->base + def.sym->st_value;
1541 if (invalid_dso_handle(p))
1545 sym = gnu_lookup(s, gh, p);
1548 sym = sysv_lookup(s, h, p);
1550 if (sym && (sym->st_info&0xf) == STT_TLS)
1551 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1552 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1553 return p->base + sym->st_value;
1554 if (p->deps) for (i=0; p->deps[i]; i++) {
1555 if (p->deps[i]->ghashtab) {
1556 if (!gh) gh = gnu_hash(s);
1557 sym = gnu_lookup(s, gh, p->deps[i]);
1559 if (!h) h = sysv_hash(s);
1560 sym = sysv_lookup(s, h, p->deps[i]);
1562 if (sym && (sym->st_info&0xf) == STT_TLS)
1563 return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1564 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1565 return p->deps[i]->base + sym->st_value;
1568 error("Symbol not found: %s", s);
1572 int __dladdr(const void *addr, Dl_info *info)
1582 pthread_rwlock_rdlock(&lock);
1583 for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1584 pthread_rwlock_unlock(&lock);
1589 strings = p->strings;
1591 nsym = p->hashtab[1];
1595 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1596 sym += p->ghashtab[1];
1597 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1598 if (buckets[i] > nsym)
1602 nsym -= p->ghashtab[1];
1603 hashval = buckets + p->ghashtab[0] + nsym;
1605 while (!(*hashval++ & 1));
1609 for (; nsym; nsym--, sym++) {
1611 && (1<<(sym->st_info&0xf) & OK_TYPES)
1612 && (1<<(sym->st_info>>4) & OK_BINDS)) {
1613 void *symaddr = p->base + sym->st_value;
1614 if (symaddr > addr || symaddr < best)
1617 bestname = strings + sym->st_name;
1618 if (addr == symaddr)
1623 if (!best) return 0;
1625 info->dli_fname = p->name;
1626 info->dli_fbase = p->base;
1627 info->dli_sname = bestname;
1628 info->dli_saddr = best;
1633 __attribute__((__visibility__("hidden")))
1634 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1637 pthread_rwlock_rdlock(&lock);
1638 res = do_dlsym(p, s, ra);
1639 pthread_rwlock_unlock(&lock);
1643 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1645 struct dso *current;
1646 struct dl_phdr_info info;
1648 for(current = head; current;) {
1649 info.dlpi_addr = (uintptr_t)current->base;
1650 info.dlpi_name = current->name;
1651 info.dlpi_phdr = current->phdr;
1652 info.dlpi_phnum = current->phnum;
1653 info.dlpi_adds = gencnt;
1655 info.dlpi_tls_modid = current->tls_id;
1656 info.dlpi_tls_data = current->tls_image;
1658 ret = (callback)(&info, sizeof (info), data);
1660 if (ret != 0) break;
1662 pthread_rwlock_rdlock(&lock);
1663 current = current->next;
1664 pthread_rwlock_unlock(&lock);
1669 static int invalid_dso_handle(void *h)
1671 error("Invalid library handle %p", (void *)h);
1674 void *dlopen(const char *file, int mode)
1676 error("Dynamic loading not supported");
1679 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1681 error("Symbol not found: %s", s);
1684 int __dladdr (const void *addr, Dl_info *info)
1690 int __dlinfo(void *dso, int req, void *res)
1692 if (invalid_dso_handle(dso)) return -1;
1693 if (req != RTLD_DI_LINKMAP) {
1694 error("Unsupported request %d", req);
1697 *(struct link_map **)res = dso;
1703 pthread_t self = __pthread_self();
1704 if (!self->dlerror_flag) return 0;
1705 self->dlerror_flag = 0;
1706 char *s = self->dlerror_buf;
1707 if (s == (void *)-1)
1708 return "Dynamic linker failed to allocate memory for error message";
1713 int dlclose(void *p)
1715 return invalid_dso_handle(p);
1718 void __dl_thread_cleanup(void)
1720 pthread_t self = __pthread_self();
1721 if (self->dlerror_buf != (void *)-1)
1722 free(self->dlerror_buf);
1725 static void error(const char *fmt, ...)
1731 vdprintf(2, fmt, ap);
1738 pthread_t self = __pthread_self();
1739 if (self->dlerror_buf != (void *)-1)
1740 free(self->dlerror_buf);
1741 size_t len = vsnprintf(0, 0, fmt, ap);
1743 char *buf = malloc(len+1);
1746 vsnprintf(buf, len+1, fmt, ap);
1751 self->dlerror_buf = buf;
1752 self->dlerror_flag = 1;