2 #define SYSCALL_NO_TLS 1
20 #include <semaphore.h>
21 #include <sys/membarrier.h>
22 #include "pthread_impl.h"
23 #include "fork_impl.h"
27 #define malloc __libc_malloc
28 #define calloc __libc_calloc
29 #define realloc __libc_realloc
30 #define free __libc_free
32 static void error_impl(const char *, ...);
33 static void error_noop(const char *, ...);
34 static void (*error)(const char *, ...) = error_noop;
36 #define MAXP2(a,b) (-(-(a)&-(b)))
37 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
39 #define container_of(p,t,m) ((t*)((char *)(p)-offsetof(t,m)))
40 #define countof(a) ((sizeof (a))/(sizeof (a)[0]))
52 struct td_index *next;
57 struct fdpic_loadmap *loadmap;
63 struct dso *next, *prev;
73 struct dso *syms_next, *lazy_next;
74 size_t *lazy, lazy_cnt;
85 struct dso **deps, *needed_by;
88 pthread_t ctor_visitor;
89 char *rpath_orig, *rpath;
90 struct tls_module tls;
92 size_t relro_start, relro_end;
94 unsigned char *new_tls;
95 struct td_index *td_index;
96 struct dso *fini_next;
101 struct fdpic_loadmap *loadmap;
116 typedef void (*stage3_func)(size_t *, size_t *);
118 static struct builtin_tls {
123 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
125 #define ADDEND_LIMIT 4096
126 static size_t *saved_addends, *apply_addends_to;
128 static struct dso ldso;
129 static struct dso *head, *tail, *fini_head, *syms_tail, *lazy_head;
130 static char *env_path, *sys_path;
131 static unsigned long long gencnt;
134 static int ldso_fail;
136 static int shutting_down;
137 static jmp_buf *rtld_fail;
138 static pthread_rwlock_t lock;
139 static struct debug debug;
140 static struct tls_module *tls_tail;
141 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
142 static size_t static_tls_cnt;
143 static pthread_mutex_t init_fini_lock;
144 static pthread_cond_t ctor_cond;
145 static struct dso *builtin_deps[2];
146 static struct dso *const no_deps[1];
147 static struct dso *builtin_ctor_queue[4];
148 static struct dso **main_ctor_queue;
149 static struct fdpic_loadmap *app_loadmap;
150 static struct fdpic_dummy_loadmap app_dummy_loadmap;
152 struct debug *_dl_debug_addr = &debug;
154 extern hidden int __malloc_replaced;
156 hidden void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
158 extern hidden void (*const __init_array_end)(void), (*const __fini_array_end)(void);
160 weak_alias(__init_array_start, __init_array_end);
161 weak_alias(__fini_array_start, __fini_array_end);
163 static int dl_strcmp(const char *l, const char *r)
165 for (; *l==*r && *l; l++, r++);
166 return *(unsigned char *)l - *(unsigned char *)r;
168 #define strcmp(l,r) dl_strcmp(l,r)
170 /* Compute load address for a virtual address in a given dso. */
172 static void *laddr(const struct dso *p, size_t v)
175 if (!p->loadmap) return p->base + v;
176 for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
177 return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
179 static void *laddr_pg(const struct dso *p, size_t v)
182 size_t pgsz = PAGE_SIZE;
183 if (!p->loadmap) return p->base + v;
185 size_t a = p->loadmap->segs[j].p_vaddr;
186 size_t b = a + p->loadmap->segs[j].p_memsz;
192 return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
194 static void (*fdbarrier(void *p))()
197 __asm__("" : "=r"(fd) : "0"(p));
200 #define fpaddr(p, v) fdbarrier((&(struct funcdesc){ \
201 laddr(p, v), (p)->got }))
203 #define laddr(p, v) (void *)((p)->base + (v))
204 #define laddr_pg(p, v) laddr(p, v)
205 #define fpaddr(p, v) ((void (*)())laddr(p, v))
208 static void decode_vec(size_t *v, size_t *a, size_t cnt)
211 for (i=0; i<cnt; i++) a[i] = 0;
212 for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
213 if (v[0] < 8*sizeof(long))
219 static int search_vec(size_t *v, size_t *r, size_t key)
221 for (; v[0]!=key; v+=2)
227 static uint32_t sysv_hash(const char *s0)
229 const unsigned char *s = (void *)s0;
235 return h & 0xfffffff;
238 static uint32_t gnu_hash(const char *s0)
240 const unsigned char *s = (void *)s0;
241 uint_fast32_t h = 5381;
247 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
250 Sym *syms = dso->syms;
251 Elf_Symndx *hashtab = dso->hashtab;
252 char *strings = dso->strings;
253 for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
254 if ((!dso->versym || dso->versym[i] >= 0)
255 && (!strcmp(s, strings+syms[i].st_name)))
261 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
263 uint32_t nbuckets = hashtab[0];
264 uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
265 uint32_t i = buckets[h1 % nbuckets];
269 uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
271 for (h1 |= 1; ; i++) {
272 uint32_t h2 = *hashval++;
273 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
274 && !strcmp(s, dso->strings + dso->syms[i].st_name))
282 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
284 const size_t *bloomwords = (const void *)(hashtab+4);
285 size_t f = bloomwords[fofs & (hashtab[2]-1)];
286 if (!(f & fmask)) return 0;
288 f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
289 if (!(f & 1)) return 0;
291 return gnu_lookup(h1, hashtab, dso, s);
294 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
295 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
297 #ifndef ARCH_SYM_REJECT_UND
298 #define ARCH_SYM_REJECT_UND(s) 0
301 #if defined(__GNUC__)
302 __attribute__((always_inline))
304 static inline struct symdef find_sym2(struct dso *dso, const char *s, int need_def, int use_deps)
306 uint32_t h = 0, gh = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght;
307 size_t ghm = 1ul << gh % (8*sizeof(size_t));
308 struct symdef def = {0};
309 struct dso **deps = use_deps ? dso->deps : 0;
310 for (; dso; dso=use_deps ? *deps++ : dso->syms_next) {
312 if ((ght = dso->ghashtab)) {
313 sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
315 if (!h) h = sysv_hash(s);
316 sym = sysv_lookup(s, h, dso);
320 if (need_def || (sym->st_info&0xf) == STT_TLS
321 || ARCH_SYM_REJECT_UND(sym))
324 if ((sym->st_info&0xf) != STT_TLS)
326 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
327 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
335 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
337 return find_sym2(dso, s, need_def, 0);
340 static struct symdef get_lfs64(const char *name)
342 static const char *p, lfs64_list[] =
343 "aio_cancel\0aio_error\0aio_fsync\0aio_read\0aio_return\0"
344 "aio_suspend\0aio_write\0alphasort\0creat\0fallocate\0"
345 "fgetpos\0fopen\0freopen\0fseeko\0fsetpos\0fstat\0"
346 "fstatat\0fstatfs\0fstatvfs\0ftello\0ftruncate\0ftw\0"
347 "getdents\0getrlimit\0glob\0globfree\0lio_listio\0"
348 "lockf\0lseek\0lstat\0mkostemp\0mkostemps\0mkstemp\0"
349 "mkstemps\0mmap\0nftw\0open\0openat\0posix_fadvise\0"
350 "posix_fallocate\0pread\0preadv\0prlimit\0pwrite\0"
351 "pwritev\0readdir\0scandir\0sendfile\0setrlimit\0"
352 "stat\0statfs\0statvfs\0tmpfile\0truncate\0versionsort\0"
353 "__fxstat\0__fxstatat\0__lxstat\0__xstat\0";
356 for (l=0; name[l]; l++) {
357 if (l >= sizeof buf) goto nomatch;
360 if (!strcmp(name, "readdir64_r"))
361 return find_sym(&ldso, "readdir_r", 1);
362 if (l<2 || name[l-2]!='6' || name[l-1]!='4')
365 for (p=lfs64_list; *p; p++) {
366 if (!strcmp(buf, p)) return find_sym(&ldso, buf, 1);
370 return (struct symdef){ 0 };
373 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
375 unsigned char *base = dso->base;
376 Sym *syms = dso->syms;
377 char *strings = dso->strings;
388 int skip_relative = 0, reuse_addends = 0, save_slot = 0;
391 /* Only ldso's REL table needs addend saving/reuse. */
392 if (rel == apply_addends_to)
397 for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
398 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
399 type = R_TYPE(rel[1]);
400 if (type == REL_NONE) continue;
401 reloc_addr = laddr(dso, rel[0]);
405 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
407 } else if (reuse_addends) {
408 /* Save original addend in stage 2 where the dso
409 * chain consists of just ldso; otherwise read back
410 * saved addend since the inline one was clobbered. */
412 saved_addends[save_slot] = *reloc_addr;
413 addend = saved_addends[save_slot++];
415 addend = *reloc_addr;
418 sym_index = R_SYM(rel[1]);
420 sym = syms + sym_index;
421 name = strings + sym->st_name;
422 ctx = type==REL_COPY ? head->syms_next : head;
423 def = (sym->st_info>>4) == STB_LOCAL
424 ? (struct symdef){ .dso = dso, .sym = sym }
425 : find_sym(ctx, name, type==REL_PLT);
426 if (!def.sym) def = get_lfs64(name);
427 if (!def.sym && (sym->st_shndx != SHN_UNDEF
428 || sym->st_info>>4 != STB_WEAK)) {
429 if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
430 dso->lazy[3*dso->lazy_cnt+0] = rel[0];
431 dso->lazy[3*dso->lazy_cnt+1] = rel[1];
432 dso->lazy[3*dso->lazy_cnt+2] = addend;
436 error("Error relocating %s: %s: symbol not found",
438 if (runtime) longjmp(*rtld_fail, 1);
447 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
448 tls_val = def.sym ? def.sym->st_value : 0;
450 if ((type == REL_TPOFF || type == REL_TPOFF_NEG)
451 && def.dso->tls_id > static_tls_cnt) {
452 error("Error relocating %s: %s: initial-exec TLS "
453 "resolves to dynamic definition in %s",
454 dso->name, name, def.dso->name);
455 longjmp(*rtld_fail, 1);
460 addend -= (size_t)reloc_addr;
464 *reloc_addr = sym_val + addend;
467 memcpy(reloc_addr, &(size_t){sym_val + addend}, sizeof(size_t));
470 *reloc_addr = (size_t)base + addend;
473 if (sym) *reloc_addr = sym_val + addend;
474 else *reloc_addr = (size_t)base + addend;
477 memcpy(reloc_addr, (void *)sym_val, sym->st_size);
480 *(uint32_t *)reloc_addr = sym_val + addend
481 - (size_t)reloc_addr;
484 *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
485 + (def.sym - def.dso->syms)) : 0;
487 case REL_FUNCDESC_VAL:
488 if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
489 else *reloc_addr = sym_val;
490 reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
493 *reloc_addr = def.dso->tls_id;
496 *reloc_addr = tls_val + addend - DTP_OFFSET;
500 *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
504 *reloc_addr = tls_val - def.dso->tls.offset + addend;
507 *reloc_addr = def.dso->tls.offset - tls_val + addend;
511 if (stride<3) addend = reloc_addr[1];
512 if (def.dso->tls_id > static_tls_cnt) {
513 struct td_index *new = malloc(sizeof *new);
516 "Error relocating %s: cannot allocate TLSDESC for %s",
517 dso->name, sym ? name : "(local)" );
518 longjmp(*rtld_fail, 1);
520 new->next = dso->td_index;
522 new->args[0] = def.dso->tls_id;
523 new->args[1] = tls_val + addend - DTP_OFFSET;
524 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
525 reloc_addr[1] = (size_t)new;
527 reloc_addr[0] = (size_t)__tlsdesc_static;
529 reloc_addr[1] = tls_val + def.dso->tls.offset
532 reloc_addr[1] = tls_val - def.dso->tls.offset
536 #ifdef TLSDESC_BACKWARDS
537 /* Some archs (32-bit ARM at least) invert the order of
538 * the descriptor members. Fix them up here. */
539 size_t tmp = reloc_addr[0];
540 reloc_addr[0] = reloc_addr[1];
545 error("Error relocating %s: unsupported relocation type %d",
547 if (runtime) longjmp(*rtld_fail, 1);
553 static void do_relr_relocs(struct dso *dso, size_t *relr, size_t relr_size)
555 if (dso == &ldso) return; /* self-relocation was done in _dlstart */
556 unsigned char *base = dso->base;
558 for (; relr_size; relr++, relr_size-=sizeof(size_t))
559 if ((relr[0]&1) == 0) {
560 reloc_addr = laddr(dso, relr[0]);
561 *reloc_addr++ += (size_t)base;
564 for (size_t bitmap=relr[0]; (bitmap>>=1); i++)
566 reloc_addr[i] += (size_t)base;
567 reloc_addr += 8*sizeof(size_t)-1;
571 static void redo_lazy_relocs()
573 struct dso *p = lazy_head, *next;
577 size_t size = p->lazy_cnt*3*sizeof(size_t);
579 do_relocs(p, p->lazy, size, 3);
581 p->lazy_next = lazy_head;
591 /* A huge hack: to make up for the wastefulness of shared libraries
592 * needing at least a page of dirty memory even if they have no global
593 * data, we reclaim the gaps at the beginning and end of writable maps
594 * and "donate" them to the heap. */
596 static void reclaim(struct dso *dso, size_t start, size_t end)
598 if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
599 if (end >= dso->relro_start && end < dso->relro_end) end = dso->relro_start;
600 if (start >= end) return;
601 char *base = laddr_pg(dso, start);
602 __malloc_donate(base, base+(end-start));
605 static void reclaim_gaps(struct dso *dso)
607 Phdr *ph = dso->phdr;
608 size_t phcnt = dso->phnum;
610 for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
611 if (ph->p_type!=PT_LOAD) continue;
612 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
613 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
614 reclaim(dso, ph->p_vaddr+ph->p_memsz,
615 ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
619 static ssize_t read_loop(int fd, void *p, size_t n)
621 for (size_t i=0; i<n; ) {
622 ssize_t l = read(fd, (char *)p+i, n-i);
624 if (errno==EINTR) continue;
633 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
635 static int no_map_fixed;
639 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
640 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
644 /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
645 if (flags & MAP_ANONYMOUS) {
650 if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
651 for (q=p; n; q+=r, off+=r, n-=r) {
653 if (r < 0 && errno != EINTR) return MAP_FAILED;
662 static void unmap_library(struct dso *dso)
666 for (i=0; i<dso->loadmap->nsegs; i++) {
667 if (!dso->loadmap->segs[i].p_memsz)
669 munmap((void *)dso->loadmap->segs[i].addr,
670 dso->loadmap->segs[i].p_memsz);
673 } else if (dso->map && dso->map_len) {
674 munmap(dso->map, dso->map_len);
678 static void *map_library(int fd, struct dso *dso)
680 Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
681 void *allocated_buf=0;
683 size_t addr_min=SIZE_MAX, addr_max=0, map_len;
684 size_t this_min, this_max;
690 unsigned char *map=MAP_FAILED, *base;
695 ssize_t l = read(fd, buf, sizeof buf);
698 if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
700 phsize = eh->e_phentsize * eh->e_phnum;
701 if (phsize > sizeof buf - sizeof *eh) {
702 allocated_buf = malloc(phsize);
703 if (!allocated_buf) return 0;
704 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
705 if (l < 0) goto error;
706 if (l != phsize) goto noexec;
707 ph = ph0 = allocated_buf;
708 } else if (eh->e_phoff + phsize > l) {
709 l = pread(fd, buf+1, phsize, eh->e_phoff);
710 if (l < 0) goto error;
711 if (l != phsize) goto noexec;
712 ph = ph0 = (void *)(buf + 1);
714 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
716 for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
717 if (ph->p_type == PT_DYNAMIC) {
719 } else if (ph->p_type == PT_TLS) {
720 tls_image = ph->p_vaddr;
721 dso->tls.align = ph->p_align;
722 dso->tls.len = ph->p_filesz;
723 dso->tls.size = ph->p_memsz;
724 } else if (ph->p_type == PT_GNU_RELRO) {
725 dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
726 dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
727 } else if (ph->p_type == PT_GNU_STACK) {
728 if (!runtime && ph->p_memsz > __default_stacksize) {
729 __default_stacksize =
730 ph->p_memsz < DEFAULT_STACK_MAX ?
731 ph->p_memsz : DEFAULT_STACK_MAX;
734 if (ph->p_type != PT_LOAD) continue;
736 if (ph->p_vaddr < addr_min) {
737 addr_min = ph->p_vaddr;
738 off_start = ph->p_offset;
739 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
740 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
741 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
743 if (ph->p_vaddr+ph->p_memsz > addr_max) {
744 addr_max = ph->p_vaddr+ph->p_memsz;
747 if (!dyn) goto noexec;
748 if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
749 dso->loadmap = calloc(1, sizeof *dso->loadmap
750 + nsegs * sizeof *dso->loadmap->segs);
751 if (!dso->loadmap) goto error;
752 dso->loadmap->nsegs = nsegs;
753 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
754 if (ph->p_type != PT_LOAD) continue;
755 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
756 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
757 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
758 map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
760 fd, ph->p_offset & -PAGE_SIZE);
761 if (map == MAP_FAILED) {
765 dso->loadmap->segs[i].addr = (size_t)map +
766 (ph->p_vaddr & PAGE_SIZE-1);
767 dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
768 dso->loadmap->segs[i].p_memsz = ph->p_memsz;
770 if (prot & PROT_WRITE) {
771 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
773 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
774 size_t pgend = brk + ph->p_memsz - ph->p_filesz
775 + PAGE_SIZE-1 & -PAGE_SIZE;
776 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
778 MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
779 -1, off_start) == MAP_FAILED)
781 memset(map + brk, 0, pgbrk-brk);
784 map = (void *)dso->loadmap->segs[0].addr;
788 addr_max += PAGE_SIZE-1;
789 addr_max &= -PAGE_SIZE;
790 addr_min &= -PAGE_SIZE;
791 off_start &= -PAGE_SIZE;
792 map_len = addr_max - addr_min + off_start;
793 /* The first time, we map too much, possibly even more than
794 * the length of the file. This is okay because we will not
795 * use the invalid part; we just need to reserve the right
796 * amount of virtual address space to map over later. */
797 map = DL_NOMMU_SUPPORT
798 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
799 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
800 : mmap((void *)addr_min, map_len, prot,
801 MAP_PRIVATE, fd, off_start);
802 if (map==MAP_FAILED) goto error;
804 dso->map_len = map_len;
805 /* If the loaded file is not relocatable and the requested address is
806 * not available, then the load operation must fail. */
807 if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
811 base = map - addr_min;
814 for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
815 if (ph->p_type != PT_LOAD) continue;
816 /* Check if the programs headers are in this load segment, and
817 * if so, record the address for use by dl_iterate_phdr. */
818 if (!dso->phdr && eh->e_phoff >= ph->p_offset
819 && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
820 dso->phdr = (void *)(base + ph->p_vaddr
821 + (eh->e_phoff-ph->p_offset));
822 dso->phnum = eh->e_phnum;
823 dso->phentsize = eh->e_phentsize;
825 this_min = ph->p_vaddr & -PAGE_SIZE;
826 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
827 off_start = ph->p_offset & -PAGE_SIZE;
828 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
829 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
830 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
831 /* Reuse the existing mapping for the lowest-address LOAD */
832 if ((ph->p_vaddr & -PAGE_SIZE) != addr_min || DL_NOMMU_SUPPORT)
833 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
835 if (ph->p_memsz > ph->p_filesz && (ph->p_flags&PF_W)) {
836 size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
837 size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
838 memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
839 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)
843 for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
844 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
845 if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
852 dso->dynv = laddr(dso, dyn);
853 if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
859 if (map!=MAP_FAILED) unmap_library(dso);
864 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
869 s += strspn(s, ":\n");
870 l = strcspn(s, ":\n");
871 if (l-1 >= INT_MAX) return -1;
872 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
873 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
881 /* Any negative value but -1 will inhibit
882 * futher path search. */
890 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
893 const char *s, *t, *origin;
895 if (p->rpath || !p->rpath_orig) return 0;
896 if (!strchr(p->rpath_orig, '$')) {
897 p->rpath = p->rpath_orig;
902 while ((t=strchr(s, '$'))) {
903 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
908 if (n > SSIZE_MAX/PATH_MAX) return 0;
910 if (p->kernel_mapped) {
911 /* $ORIGIN searches cannot be performed for the main program
912 * when it is suid/sgid/AT_SECURE. This is because the
913 * pathname is under the control of the caller of execve.
914 * For libraries, however, $ORIGIN can be processed safely
915 * since the library's pathname came from a trusted source
916 * (either system paths or a call to dlopen). */
919 l = readlink("/proc/self/exe", buf, buf_size);
920 if (l == -1) switch (errno) {
935 t = strrchr(origin, '/');
939 /* Normally p->name will always be an absolute or relative
940 * pathname containing at least one '/' character, but in the
941 * case where ldso was invoked as a command to execute a
942 * program in the working directory, app.name may not. Fix. */
946 /* Disallow non-absolute origins for suid/sgid/AT_SECURE. */
947 if (libc.secure && *origin != '/')
949 p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
950 if (!p->rpath) return -1;
954 while ((t=strchr(s, '$'))) {
957 memcpy(d, origin, l);
959 /* It was determined previously that the '$' is followed
960 * either by "ORIGIN" or "{ORIGIN}". */
961 s = t + 7 + 2*(t[1]=='{');
967 static void decode_dyn(struct dso *p)
970 decode_vec(p->dynv, dyn, DYN_CNT);
971 p->syms = laddr(p, dyn[DT_SYMTAB]);
972 p->strings = laddr(p, dyn[DT_STRTAB]);
973 if (dyn[0]&(1<<DT_HASH))
974 p->hashtab = laddr(p, dyn[DT_HASH]);
975 if (dyn[0]&(1<<DT_RPATH))
976 p->rpath_orig = p->strings + dyn[DT_RPATH];
977 if (dyn[0]&(1<<DT_RUNPATH))
978 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
979 if (dyn[0]&(1<<DT_PLTGOT))
980 p->got = laddr(p, dyn[DT_PLTGOT]);
981 if (search_vec(p->dynv, dyn, DT_GNU_HASH))
982 p->ghashtab = laddr(p, *dyn);
983 if (search_vec(p->dynv, dyn, DT_VERSYM))
984 p->versym = laddr(p, *dyn);
987 static size_t count_syms(struct dso *p)
989 if (p->hashtab) return p->hashtab[1];
992 uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
994 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
995 if (buckets[i] > nsym)
999 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
1001 while (!(*hashval++ & 1));
1006 static void *dl_mmap(size_t n)
1009 int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
1011 p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
1013 p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
1015 return (unsigned long)p > -4096UL ? 0 : p;
1018 static void makefuncdescs(struct dso *p)
1020 static int self_done;
1021 size_t nsym = count_syms(p);
1022 size_t i, size = nsym * sizeof(*p->funcdescs);
1025 p->funcdescs = dl_mmap(size);
1028 p->funcdescs = malloc(size);
1030 if (!p->funcdescs) {
1031 if (!runtime) a_crash();
1032 error("Error allocating function descriptors for %s", p->name);
1033 longjmp(*rtld_fail, 1);
1035 for (i=0; i<nsym; i++) {
1036 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
1037 p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
1038 p->funcdescs[i].got = p->got;
1040 p->funcdescs[i].addr = 0;
1041 p->funcdescs[i].got = 0;
1046 static struct dso *load_library(const char *name, struct dso *needed_by)
1048 char buf[2*NAME_MAX+2];
1049 const char *pathname;
1051 struct dso *p, temp_dso = {0};
1063 /* Catch and block attempts to reload the implementation itself */
1064 if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
1065 static const char reserved[] =
1066 "c.pthread.rt.m.dl.util.xnet.";
1067 const char *rp, *next;
1068 for (rp=reserved; *rp; rp=next) {
1069 next = strchr(rp, '.') + 1;
1070 if (strncmp(name+3, rp, next-rp) == 0)
1075 /* Track which names have been resolved
1076 * and only report each one once. */
1077 static unsigned reported;
1078 unsigned mask = 1U<<(rp-reserved);
1079 if (!(reported & mask)) {
1081 dprintf(1, "\t%s => %s (%p)\n",
1089 if (!strcmp(name, ldso.name)) is_self = 1;
1098 if (strchr(name, '/')) {
1100 fd = open(name, O_RDONLY|O_CLOEXEC);
1102 /* Search for the name to see if it's already loaded */
1103 for (p=head->next; p; p=p->next) {
1104 if (p->shortname && !strcmp(p->shortname, name)) {
1108 if (strlen(name) > NAME_MAX) return 0;
1110 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
1111 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
1112 if (fixup_rpath(p, buf, sizeof buf) < 0)
1113 fd = -2; /* Inhibit further search. */
1115 fd = path_open(name, p->rpath, buf, sizeof buf);
1121 if (ldso.name[0]=='/') {
1123 for (s=t=z=ldso.name; *s; s++)
1124 if (*s=='/') z=t, t=s;
1125 prefix_len = z-ldso.name;
1126 if (prefix_len < PATH_MAX)
1133 char etc_ldso_path[prefix_len + 1
1134 + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
1135 snprintf(etc_ldso_path, sizeof etc_ldso_path,
1136 "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
1137 (int)prefix_len, prefix);
1138 fd = open(etc_ldso_path, O_RDONLY|O_CLOEXEC);
1141 if (!fstat(fd, &st)) n = st.st_size;
1142 if ((sys_path = malloc(n+1)))
1144 if (!sys_path || read_loop(fd, sys_path, n)<0) {
1149 } else if (errno != ENOENT) {
1153 if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
1154 fd = path_open(name, sys_path, buf, sizeof buf);
1158 if (fd < 0) return 0;
1159 if (fstat(fd, &st) < 0) {
1163 for (p=head->next; p; p=p->next) {
1164 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1165 /* If this library was previously loaded with a
1166 * pathname but a search found the same inode,
1167 * setup its shortname so it can be found by name. */
1168 if (!p->shortname && pathname != name)
1169 p->shortname = strrchr(p->name, '/')+1;
1174 map = noload ? 0 : map_library(fd, &temp_dso);
1178 /* Avoid the danger of getting two versions of libc mapped into the
1179 * same process when an absolute pathname was used. The symbols
1180 * checked are chosen to catch both musl and glibc, and to avoid
1181 * false positives from interposition-hack libraries. */
1182 decode_dyn(&temp_dso);
1183 if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
1184 find_sym(&temp_dso, "stdin", 1).sym) {
1185 unmap_library(&temp_dso);
1186 return load_library("libc.so", needed_by);
1188 /* Past this point, if we haven't reached runtime yet, ldso has
1189 * committed either to use the mapped library or to abort execution.
1190 * Unmapping is not possible, so we can safely reclaim gaps. */
1191 if (!runtime) reclaim_gaps(&temp_dso);
1193 /* Allocate storage for the new DSO. When there is TLS, this
1194 * storage must include a reservation for all pre-existing
1195 * threads to obtain copies of both the new TLS, and an
1196 * extended DTV capable of storing an additional slot for
1197 * the newly-loaded DSO. */
1198 alloc_size = sizeof *p + strlen(pathname) + 1;
1199 if (runtime && temp_dso.tls.image) {
1200 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1201 + sizeof(void *) * (tls_cnt+3);
1202 n_th = libc.threads_minus_1 + 1;
1203 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1204 else alloc_size += n_th * per_th;
1206 p = calloc(1, alloc_size);
1208 unmap_library(&temp_dso);
1211 memcpy(p, &temp_dso, sizeof temp_dso);
1214 p->needed_by = needed_by;
1216 p->runtime_loaded = runtime;
1217 strcpy(p->name, pathname);
1218 /* Add a shortname only if name arg was not an explicit pathname. */
1219 if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1221 p->tls_id = ++tls_cnt;
1222 tls_align = MAXP2(tls_align, p->tls.align);
1224 p->tls.offset = tls_offset + ( (p->tls.align-1) &
1225 (-tls_offset + (uintptr_t)p->tls.image) );
1226 tls_offset = p->tls.offset + p->tls.size;
1228 tls_offset += p->tls.size + p->tls.align - 1;
1229 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1231 p->tls.offset = tls_offset;
1233 p->new_dtv = (void *)(-sizeof(size_t) &
1234 (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1235 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1236 if (tls_tail) tls_tail->next = &p->tls;
1237 else libc.tls_head = &p->tls;
1245 if (DL_FDPIC) makefuncdescs(p);
1247 if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1252 static void load_direct_deps(struct dso *p)
1256 if (p->deps) return;
1257 /* For head, all preloads are direct pseudo-dependencies.
1258 * Count and include them now to avoid realloc later. */
1259 if (p==head) for (struct dso *q=p->next; q; q=q->next)
1261 for (i=0; p->dynv[i]; i+=2)
1262 if (p->dynv[i] == DT_NEEDED) cnt++;
1263 /* Use builtin buffer for apps with no external deps, to
1264 * preserve property of no runtime failure paths. */
1265 p->deps = (p==head && cnt<2) ? builtin_deps :
1266 calloc(cnt+1, sizeof *p->deps);
1268 error("Error loading dependencies for %s", p->name);
1269 if (runtime) longjmp(*rtld_fail, 1);
1272 if (p==head) for (struct dso *q=p->next; q; q=q->next)
1274 for (i=0; p->dynv[i]; i+=2) {
1275 if (p->dynv[i] != DT_NEEDED) continue;
1276 struct dso *dep = load_library(p->strings + p->dynv[i+1], p);
1278 error("Error loading shared library %s: %m (needed by %s)",
1279 p->strings + p->dynv[i+1], p->name);
1280 if (runtime) longjmp(*rtld_fail, 1);
1283 p->deps[cnt++] = dep;
1286 p->ndeps_direct = cnt;
1289 static void load_deps(struct dso *p)
1291 if (p->deps) return;
1292 for (; p; p=p->next)
1293 load_direct_deps(p);
1296 static void extend_bfs_deps(struct dso *p)
1298 size_t i, j, cnt, ndeps_all;
1301 /* Can't use realloc if the original p->deps was allocated at
1302 * program entry and malloc has been replaced, or if it's
1303 * the builtin non-allocated trivial main program deps array. */
1304 int no_realloc = (__malloc_replaced && !p->runtime_loaded)
1305 || p->deps == builtin_deps;
1307 if (p->bfs_built) return;
1308 ndeps_all = p->ndeps_direct;
1310 /* Mark existing (direct) deps so they won't be duplicated. */
1311 for (i=0; p->deps[i]; i++)
1312 p->deps[i]->mark = 1;
1314 /* For each dependency already in the list, copy its list of direct
1315 * dependencies to the list, excluding any items already in the
1316 * list. Note that the list this loop iterates over will grow during
1317 * the loop, but since duplicates are excluded, growth is bounded. */
1318 for (i=0; p->deps[i]; i++) {
1319 struct dso *dep = p->deps[i];
1320 for (j=cnt=0; j<dep->ndeps_direct; j++)
1321 if (!dep->deps[j]->mark) cnt++;
1323 malloc(sizeof(*tmp) * (ndeps_all+cnt+1)) :
1324 realloc(p->deps, sizeof(*tmp) * (ndeps_all+cnt+1));
1326 error("Error recording dependencies for %s", p->name);
1327 if (runtime) longjmp(*rtld_fail, 1);
1331 memcpy(tmp, p->deps, sizeof(*tmp) * (ndeps_all+1));
1335 for (j=0; j<dep->ndeps_direct; j++) {
1336 if (dep->deps[j]->mark) continue;
1337 dep->deps[j]->mark = 1;
1338 p->deps[ndeps_all++] = dep->deps[j];
1340 p->deps[ndeps_all] = 0;
1343 for (p=head; p; p=p->next)
1347 static void load_preload(char *s)
1351 for (z=s; *z; s=z) {
1352 for ( ; *s && (isspace(*s) || *s==':'); s++);
1353 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1361 static void add_syms(struct dso *p)
1363 if (!p->syms_next && syms_tail != p) {
1364 syms_tail->syms_next = p;
1369 static void revert_syms(struct dso *old_tail)
1371 struct dso *p, *next;
1372 /* Chop off the tail of the list of dsos that participate in
1373 * the global symbol table, reverting them to RTLD_LOCAL. */
1374 for (p=old_tail; p; p=next) {
1375 next = p->syms_next;
1378 syms_tail = old_tail;
1381 static void do_mips_relocs(struct dso *p, size_t *got)
1383 size_t i, j, rel[2];
1384 unsigned char *base = p->base;
1385 i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1389 while (i--) *got++ += (size_t)base;
1391 j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1392 i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1393 Sym *sym = p->syms + j;
1394 rel[0] = (unsigned char *)got - base;
1395 for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1396 rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
1397 do_relocs(p, rel, sizeof rel, 2);
1401 static void reloc_all(struct dso *p)
1403 size_t dyn[DYN_CNT];
1404 for (; p; p=p->next) {
1405 if (p->relocated) continue;
1406 decode_vec(p->dynv, dyn, DYN_CNT);
1407 if (NEED_MIPS_GOT_RELOCS)
1408 do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1409 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1410 2+(dyn[DT_PLTREL]==DT_RELA));
1411 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1412 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1414 do_relr_relocs(p, laddr(p, dyn[DT_RELR]), dyn[DT_RELRSZ]);
1416 if (head != &ldso && p->relro_start != p->relro_end) {
1417 long ret = __syscall(SYS_mprotect, laddr(p, p->relro_start),
1418 p->relro_end-p->relro_start, PROT_READ);
1419 if (ret != 0 && ret != -ENOSYS) {
1420 error("Error relocating %s: RELRO protection failed: %m",
1422 if (runtime) longjmp(*rtld_fail, 1);
1430 static void kernel_mapped_dso(struct dso *p)
1432 size_t min_addr = -1, max_addr = 0, cnt;
1434 for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1435 if (ph->p_type == PT_DYNAMIC) {
1436 p->dynv = laddr(p, ph->p_vaddr);
1437 } else if (ph->p_type == PT_GNU_RELRO) {
1438 p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1439 p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1440 } else if (ph->p_type == PT_GNU_STACK) {
1441 if (!runtime && ph->p_memsz > __default_stacksize) {
1442 __default_stacksize =
1443 ph->p_memsz < DEFAULT_STACK_MAX ?
1444 ph->p_memsz : DEFAULT_STACK_MAX;
1447 if (ph->p_type != PT_LOAD) continue;
1448 if (ph->p_vaddr < min_addr)
1449 min_addr = ph->p_vaddr;
1450 if (ph->p_vaddr+ph->p_memsz > max_addr)
1451 max_addr = ph->p_vaddr+ph->p_memsz;
1453 min_addr &= -PAGE_SIZE;
1454 max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1455 p->map = p->base + min_addr;
1456 p->map_len = max_addr - min_addr;
1457 p->kernel_mapped = 1;
1460 void __libc_exit_fini()
1463 size_t dyn[DYN_CNT];
1464 pthread_t self = __pthread_self();
1466 /* Take both locks before setting shutting_down, so that
1467 * either lock is sufficient to read its value. The lock
1468 * order matches that in dlopen to avoid deadlock. */
1469 pthread_rwlock_wrlock(&lock);
1470 pthread_mutex_lock(&init_fini_lock);
1472 pthread_rwlock_unlock(&lock);
1473 for (p=fini_head; p; p=p->fini_next) {
1474 while (p->ctor_visitor && p->ctor_visitor!=self)
1475 pthread_cond_wait(&ctor_cond, &init_fini_lock);
1476 if (!p->constructed) continue;
1477 decode_vec(p->dynv, dyn, DYN_CNT);
1478 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1479 size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1480 size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1481 while (n--) ((void (*)(void))*--fn)();
1483 #ifndef NO_LEGACY_INITFINI
1484 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1485 fpaddr(p, dyn[DT_FINI])();
1490 void __ldso_atfork(int who)
1493 pthread_rwlock_wrlock(&lock);
1494 pthread_mutex_lock(&init_fini_lock);
1496 pthread_mutex_unlock(&init_fini_lock);
1497 pthread_rwlock_unlock(&lock);
1501 static struct dso **queue_ctors(struct dso *dso)
1503 size_t cnt, qpos, spos, i;
1504 struct dso *p, **queue, **stack;
1506 if (ldd_mode) return 0;
1508 /* Bound on queue size is the total number of indirect deps.
1509 * If a bfs deps list was built, we can use it. Otherwise,
1510 * bound by the total number of DSOs, which is always safe and
1511 * is reasonable we use it (for main app at startup). */
1512 if (dso->bfs_built) {
1513 for (cnt=0; dso->deps[cnt]; cnt++)
1514 dso->deps[cnt]->mark = 0;
1515 cnt++; /* self, not included in deps */
1517 for (cnt=0, p=head; p; cnt++, p=p->next)
1520 cnt++; /* termination slot */
1521 if (dso==head && cnt <= countof(builtin_ctor_queue))
1522 queue = builtin_ctor_queue;
1524 queue = calloc(cnt, sizeof *queue);
1527 error("Error allocating constructor queue: %m\n");
1528 if (runtime) longjmp(*rtld_fail, 1);
1532 /* Opposite ends of the allocated buffer serve as an output queue
1533 * and a working stack. Setup initial stack with just the argument
1534 * dso and initial queue empty... */
1538 stack[--spos] = dso;
1542 /* Then perform pseudo-DFS sort, but ignoring circular deps. */
1545 while (p->next_dep < p->ndeps_direct) {
1546 if (p->deps[p->next_dep]->mark) {
1550 p = p->deps[p->next_dep];
1558 for (i=0; i<qpos; i++) queue[i]->mark = 0;
1559 for (i=0; i<qpos; i++)
1560 if (queue[i]->ctor_visitor && queue[i]->ctor_visitor->tid < 0) {
1561 error("State of %s is inconsistent due to multithreaded fork\n",
1564 if (runtime) longjmp(*rtld_fail, 1);
1570 static void do_init_fini(struct dso **queue)
1573 size_t dyn[DYN_CNT], i;
1574 pthread_t self = __pthread_self();
1576 pthread_mutex_lock(&init_fini_lock);
1577 for (i=0; (p=queue[i]); i++) {
1578 while ((p->ctor_visitor && p->ctor_visitor!=self) || shutting_down)
1579 pthread_cond_wait(&ctor_cond, &init_fini_lock);
1580 if (p->ctor_visitor || p->constructed)
1582 p->ctor_visitor = self;
1584 decode_vec(p->dynv, dyn, DYN_CNT);
1585 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1586 p->fini_next = fini_head;
1590 pthread_mutex_unlock(&init_fini_lock);
1592 #ifndef NO_LEGACY_INITFINI
1593 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1594 fpaddr(p, dyn[DT_INIT])();
1596 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1597 size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1598 size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1599 while (n--) ((void (*)(void))*fn++)();
1602 pthread_mutex_lock(&init_fini_lock);
1603 p->ctor_visitor = 0;
1605 pthread_cond_broadcast(&ctor_cond);
1607 pthread_mutex_unlock(&init_fini_lock);
1610 void __libc_start_init(void)
1612 do_init_fini(main_ctor_queue);
1613 if (!__malloc_replaced && main_ctor_queue != builtin_ctor_queue)
1614 free(main_ctor_queue);
1615 main_ctor_queue = 0;
1618 static void dl_debug_state(void)
1622 weak_alias(dl_debug_state, _dl_debug_state);
1624 void __init_tls(size_t *auxv)
1628 static void update_tls_size()
1630 libc.tls_cnt = tls_cnt;
1631 libc.tls_align = tls_align;
1632 libc.tls_size = ALIGN(
1633 (1+tls_cnt) * sizeof(void *) +
1635 sizeof(struct pthread) +
1640 static void install_new_tls(void)
1643 pthread_t self = __pthread_self(), td;
1644 struct dso *dtv_provider = container_of(tls_tail, struct dso, tls);
1645 uintptr_t (*newdtv)[tls_cnt+1] = (void *)dtv_provider->new_dtv;
1648 size_t old_cnt = self->dtv[0];
1650 __block_app_sigs(&set);
1652 /* Copy existing dtv contents from all existing threads. */
1653 for (i=0, td=self; !i || td!=self; i++, td=td->next) {
1654 memcpy(newdtv+i, td->dtv,
1655 (old_cnt+1)*sizeof(uintptr_t));
1656 newdtv[i][0] = tls_cnt;
1658 /* Install new dtls into the enlarged, uninstalled dtv copies. */
1659 for (p=head; ; p=p->next) {
1660 if (p->tls_id <= old_cnt) continue;
1661 unsigned char *mem = p->new_tls;
1662 for (j=0; j<i; j++) {
1663 unsigned char *new = mem;
1664 new += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1666 memcpy(new, p->tls.image, p->tls.len);
1667 newdtv[j][p->tls_id] =
1668 (uintptr_t)new + DTP_OFFSET;
1669 mem += p->tls.size + p->tls.align;
1671 if (p->tls_id == tls_cnt) break;
1674 /* Broadcast barrier to ensure contents of new dtv is visible
1675 * if the new dtv pointer is. The __membarrier function has a
1676 * fallback emulation using signals for kernels that lack the
1677 * feature at the syscall level. */
1679 __membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED, 0);
1681 /* Install new dtv for each thread. */
1682 for (j=0, td=self; !j || td!=self; j++, td=td->next) {
1683 td->dtv = newdtv[j];
1687 __restore_sigs(&set);
1690 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1691 * following stage 2 and stage 3 functions via primitive symbolic lookup
1692 * since it does not have access to their addresses to begin with. */
1694 /* Stage 2 of the dynamic linker is called after relative relocations
1695 * have been processed. It can make function calls to static functions
1696 * and access string literals and static data, but cannot use extern
1697 * symbols. Its job is to perform symbolic relocations on the dynamic
1698 * linker itself, but some of the relocations performed may need to be
1699 * replaced later due to copy relocations in the main program. */
1701 hidden void __dls2(unsigned char *base, size_t *sp)
1704 for (auxv=sp+1+*sp+1; *auxv; auxv++);
1707 void *p1 = (void *)sp[-2];
1708 void *p2 = (void *)sp[-1];
1710 size_t aux[AUX_CNT];
1711 decode_vec(auxv, aux, AUX_CNT);
1712 if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1713 else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1715 app_loadmap = p2 ? p1 : 0;
1716 ldso.loadmap = p2 ? p2 : p1;
1717 ldso.base = laddr(&ldso, 0);
1721 Ehdr *ehdr = (void *)ldso.base;
1722 ldso.name = ldso.shortname = "libc.so";
1723 ldso.phnum = ehdr->e_phnum;
1724 ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1725 ldso.phentsize = ehdr->e_phentsize;
1726 kernel_mapped_dso(&ldso);
1729 if (DL_FDPIC) makefuncdescs(&ldso);
1731 /* Prepare storage for to save clobbered REL addends so they
1732 * can be reused in stage 3. There should be very few. If
1733 * something goes wrong and there are a huge number, abort
1734 * instead of risking stack overflow. */
1735 size_t dyn[DYN_CNT];
1736 decode_vec(ldso.dynv, dyn, DYN_CNT);
1737 size_t *rel = laddr(&ldso, dyn[DT_REL]);
1738 size_t rel_size = dyn[DT_RELSZ];
1739 size_t symbolic_rel_cnt = 0;
1740 apply_addends_to = rel;
1741 for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1742 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1743 if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1744 size_t addends[symbolic_rel_cnt+1];
1745 saved_addends = addends;
1752 /* Call dynamic linker stage-2b, __dls2b, looking it up
1753 * symbolically as a barrier against moving the address
1754 * load across the above relocation processing. */
1755 struct symdef dls2b_def = find_sym(&ldso, "__dls2b", 0);
1756 if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls2b_def.sym-ldso.syms])(sp, auxv);
1757 else ((stage3_func)laddr(&ldso, dls2b_def.sym->st_value))(sp, auxv);
1760 /* Stage 2b sets up a valid thread pointer, which requires relocations
1761 * completed in stage 2, and on which stage 3 is permitted to depend.
1762 * This is done as a separate stage, with symbolic lookup as a barrier,
1763 * so that loads of the thread pointer and &errno can be pure/const and
1764 * thereby hoistable. */
1766 void __dls2b(size_t *sp, size_t *auxv)
1768 /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1769 * use during dynamic linking. If possible it will also serve as the
1770 * thread pointer at runtime. */
1771 search_vec(auxv, &__hwcap, AT_HWCAP);
1773 libc.tls_size = sizeof builtin_tls;
1774 libc.tls_align = tls_align;
1775 if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1779 struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1780 if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp, auxv);
1781 else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp, auxv);
1784 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1785 * fully functional. Its job is to load (if not already loaded) and
1786 * process dependencies and relocations for the main application and
1787 * transfer control to its entry point. */
1789 void __dls3(size_t *sp, size_t *auxv)
1791 static struct dso app, vdso;
1792 size_t aux[AUX_CNT];
1794 char *env_preload=0;
1795 char *replace_argv0=0;
1798 char **argv = (void *)(sp+1);
1799 char **argv_orig = argv;
1800 char **envp = argv+argc+1;
1802 /* Find aux vector just past environ[] and use it to initialize
1803 * global data that may be needed before we can make syscalls. */
1805 decode_vec(auxv, aux, AUX_CNT);
1806 search_vec(auxv, &__sysinfo, AT_SYSINFO);
1807 __pthread_self()->sysinfo = __sysinfo;
1808 libc.page_size = aux[AT_PAGESZ];
1809 libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1810 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1812 /* Only trust user/env if kernel says we're not suid/sgid */
1814 env_path = getenv("LD_LIBRARY_PATH");
1815 env_preload = getenv("LD_PRELOAD");
1818 /* Activate error handler function */
1821 /* If the main program was already loaded by the kernel,
1822 * AT_PHDR will point to some location other than the dynamic
1823 * linker's program headers. */
1824 if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1825 size_t interp_off = 0;
1826 size_t tls_image = 0;
1827 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1828 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1829 app.phnum = aux[AT_PHNUM];
1830 app.phentsize = aux[AT_PHENT];
1831 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1832 if (phdr->p_type == PT_PHDR)
1833 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1834 else if (phdr->p_type == PT_INTERP)
1835 interp_off = (size_t)phdr->p_vaddr;
1836 else if (phdr->p_type == PT_TLS) {
1837 tls_image = phdr->p_vaddr;
1838 app.tls.len = phdr->p_filesz;
1839 app.tls.size = phdr->p_memsz;
1840 app.tls.align = phdr->p_align;
1843 if (DL_FDPIC) app.loadmap = app_loadmap;
1844 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1845 if (interp_off) ldso.name = laddr(&app, interp_off);
1846 if ((aux[0] & (1UL<<AT_EXECFN))
1847 && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1848 app.name = (char *)aux[AT_EXECFN];
1851 kernel_mapped_dso(&app);
1854 char *ldname = argv[0];
1855 size_t l = strlen(ldname);
1856 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1858 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1859 char *opt = argv[0]+2;
1860 *argv++ = (void *)-1;
1863 } else if (!memcmp(opt, "list", 5)) {
1865 } else if (!memcmp(opt, "library-path", 12)) {
1866 if (opt[12]=='=') env_path = opt+13;
1867 else if (opt[12]) *argv = 0;
1868 else if (*argv) env_path = *argv++;
1869 } else if (!memcmp(opt, "preload", 7)) {
1870 if (opt[7]=='=') env_preload = opt+8;
1871 else if (opt[7]) *argv = 0;
1872 else if (*argv) env_preload = *argv++;
1873 } else if (!memcmp(opt, "argv0", 5)) {
1874 if (opt[5]=='=') replace_argv0 = opt+6;
1875 else if (opt[5]) *argv = 0;
1876 else if (*argv) replace_argv0 = *argv++;
1881 argv[-1] = (void *)(argc - (argv-argv_orig));
1883 dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1885 "Dynamic Program Loader\n"
1886 "Usage: %s [options] [--] pathname%s\n",
1887 __libc_version, ldname,
1888 ldd_mode ? "" : " [args]");
1891 fd = open(argv[0], O_RDONLY);
1893 dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1896 Ehdr *ehdr = map_library(fd, &app);
1898 dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1904 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1905 /* Find the name that would have been used for the dynamic
1906 * linker had ldd not taken its place. */
1908 for (i=0; i<app.phnum; i++) {
1909 if (app.phdr[i].p_type == PT_INTERP)
1910 ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1912 dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1916 libc.tls_head = tls_tail = &app.tls;
1917 app.tls_id = tls_cnt = 1;
1919 app.tls.offset = GAP_ABOVE_TP;
1920 app.tls.offset += (-GAP_ABOVE_TP + (uintptr_t)app.tls.image)
1921 & (app.tls.align-1);
1922 tls_offset = app.tls.offset + app.tls.size;
1924 tls_offset = app.tls.offset = app.tls.size
1925 + ( -((uintptr_t)app.tls.image + app.tls.size)
1926 & (app.tls.align-1) );
1928 tls_align = MAXP2(tls_align, app.tls.align);
1932 makefuncdescs(&app);
1934 app.loadmap = (void *)&app_dummy_loadmap;
1935 app.loadmap->nsegs = 1;
1936 app.loadmap->segs[0].addr = (size_t)app.map;
1937 app.loadmap->segs[0].p_vaddr = (size_t)app.map
1939 app.loadmap->segs[0].p_memsz = app.map_len;
1941 argv[-3] = (void *)app.loadmap;
1944 /* Initial dso chain consists only of the app. */
1945 head = tail = syms_tail = &app;
1947 /* Donate unused parts of app and library mapping to malloc */
1949 reclaim_gaps(&ldso);
1951 /* Load preload/needed libraries, add symbols to global namespace. */
1952 ldso.deps = (struct dso **)no_deps;
1953 if (env_preload) load_preload(env_preload);
1955 for (struct dso *p=head; p; p=p->next)
1958 /* Attach to vdso, if provided by the kernel, last so that it does
1959 * not become part of the global namespace. */
1960 if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
1961 Ehdr *ehdr = (void *)vdso_base;
1962 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1963 vdso.phnum = ehdr->e_phnum;
1964 vdso.phentsize = ehdr->e_phentsize;
1965 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1966 if (phdr->p_type == PT_DYNAMIC)
1967 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1968 if (phdr->p_type == PT_LOAD)
1969 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1972 vdso.shortname = "linux-gate.so.1";
1974 vdso.deps = (struct dso **)no_deps;
1981 for (i=0; app.dynv[i]; i+=2) {
1982 if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
1983 app.dynv[i+1] = (size_t)&debug;
1984 if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
1985 size_t *ptr = (size_t *) app.dynv[i+1];
1986 *ptr = (size_t)&debug;
1990 /* This must be done before final relocations, since it calls
1991 * malloc, which may be provided by the application. Calling any
1992 * application code prior to the jump to its entry point is not
1993 * valid in our model and does not work with FDPIC, where there
1994 * are additional relocation-like fixups that only the entry point
1995 * code can see to perform. */
1996 main_ctor_queue = queue_ctors(&app);
1998 /* Initial TLS must also be allocated before final relocations
1999 * might result in calloc being a call to application code. */
2001 void *initial_tls = builtin_tls;
2002 if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
2003 initial_tls = calloc(libc.tls_size, 1);
2005 dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
2006 argv[0], libc.tls_size);
2010 static_tls_cnt = tls_cnt;
2012 /* The main program must be relocated LAST since it may contain
2013 * copy relocations which depend on libraries' relocations. */
2014 reloc_all(app.next);
2017 /* Actual copying to new TLS needs to happen after relocations,
2018 * since the TLS images might have contained relocated addresses. */
2019 if (initial_tls != builtin_tls) {
2020 if (__init_tp(__copy_tls(initial_tls)) < 0) {
2024 size_t tmp_tls_size = libc.tls_size;
2025 pthread_t self = __pthread_self();
2026 /* Temporarily set the tls size to the full size of
2027 * builtin_tls so that __copy_tls will use the same layout
2028 * as it did for before. Then check, just to be safe. */
2029 libc.tls_size = sizeof builtin_tls;
2030 if (__copy_tls((void*)builtin_tls) != self) a_crash();
2031 libc.tls_size = tmp_tls_size;
2034 if (ldso_fail) _exit(127);
2035 if (ldd_mode) _exit(0);
2037 /* Determine if malloc was interposed by a replacement implementation
2038 * so that calloc and the memalign family can harden against the
2039 * possibility of incomplete replacement. */
2040 if (find_sym(head, "malloc", 1).dso != &ldso)
2041 __malloc_replaced = 1;
2042 if (find_sym(head, "aligned_alloc", 1).dso != &ldso)
2043 __aligned_alloc_replaced = 1;
2045 /* Switch to runtime mode: any further failures in the dynamic
2046 * linker are a reportable failure rather than a fatal startup
2051 debug.bp = dl_debug_state;
2053 debug.base = ldso.base;
2054 debug.state = RT_CONSISTENT;
2057 if (replace_argv0) argv[0] = replace_argv0;
2061 CRTJMP((void *)aux[AT_ENTRY], argv-1);
2065 static void prepare_lazy(struct dso *p)
2067 size_t dyn[DYN_CNT], n, flags1=0;
2068 decode_vec(p->dynv, dyn, DYN_CNT);
2069 search_vec(p->dynv, &flags1, DT_FLAGS_1);
2070 if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
2072 n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
2073 if (NEED_MIPS_GOT_RELOCS) {
2074 size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
2075 size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
2078 p->lazy = calloc(n, 3*sizeof(size_t));
2080 error("Error preparing lazy relocation for %s: %m", p->name);
2081 longjmp(*rtld_fail, 1);
2083 p->lazy_next = lazy_head;
2087 void *dlopen(const char *file, int mode)
2089 struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
2090 struct tls_module *orig_tls_tail;
2091 size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
2095 struct dso **volatile ctor_queue = 0;
2097 if (!file) return head;
2099 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
2100 pthread_rwlock_wrlock(&lock);
2103 debug.state = RT_ADD;
2107 if (shutting_down) {
2108 error("Cannot dlopen while program is exiting.");
2111 orig_tls_tail = tls_tail;
2112 orig_tls_cnt = tls_cnt;
2113 orig_tls_offset = tls_offset;
2114 orig_tls_align = tls_align;
2115 orig_lazy_head = lazy_head;
2116 orig_syms_tail = syms_tail;
2118 noload = mode & RTLD_NOLOAD;
2121 if (setjmp(*rtld_fail)) {
2122 /* Clean up anything new that was (partially) loaded */
2123 revert_syms(orig_syms_tail);
2124 for (p=orig_tail->next; p; p=next) {
2126 while (p->td_index) {
2127 void *tmp = p->td_index->next;
2132 if (p->rpath != p->rpath_orig)
2140 if (!orig_tls_tail) libc.tls_head = 0;
2141 tls_tail = orig_tls_tail;
2142 if (tls_tail) tls_tail->next = 0;
2143 tls_cnt = orig_tls_cnt;
2144 tls_offset = orig_tls_offset;
2145 tls_align = orig_tls_align;
2146 lazy_head = orig_lazy_head;
2151 } else p = load_library(file, head);
2155 "Library %s is not already loaded" :
2156 "Error loading shared library %s: %m",
2161 /* First load handling */
2164 pthread_mutex_lock(&init_fini_lock);
2165 int constructed = p->constructed;
2166 pthread_mutex_unlock(&init_fini_lock);
2167 if (!constructed) ctor_queue = queue_ctors(p);
2168 if (!p->relocated && (mode & RTLD_LAZY)) {
2170 for (i=0; p->deps[i]; i++)
2171 if (!p->deps[i]->relocated)
2172 prepare_lazy(p->deps[i]);
2174 if (!p->relocated || (mode & RTLD_GLOBAL)) {
2175 /* Make new symbols global, at least temporarily, so we can do
2176 * relocations. If not RTLD_GLOBAL, this is reverted below. */
2178 for (i=0; p->deps[i]; i++)
2179 add_syms(p->deps[i]);
2181 if (!p->relocated) {
2185 /* If RTLD_GLOBAL was not specified, undo any new additions
2186 * to the global symbol table. This is a nop if the library was
2187 * previously loaded and already global. */
2188 if (!(mode & RTLD_GLOBAL))
2189 revert_syms(orig_syms_tail);
2191 /* Processing of deferred lazy relocations must not happen until
2192 * the new libraries are committed; otherwise we could end up with
2193 * relocations resolved to symbol definitions that get removed. */
2197 if (tls_cnt != orig_tls_cnt)
2201 debug.state = RT_CONSISTENT;
2205 pthread_rwlock_unlock(&lock);
2207 do_init_fini(ctor_queue);
2210 pthread_setcancelstate(cs, 0);
2214 hidden int __dl_invalid_handle(void *h)
2217 for (p=head; p; p=p->next) if (h==p) return 0;
2218 error("Invalid library handle %p", (void *)h);
2222 static void *addr2dso(size_t a)
2226 if (DL_FDPIC) for (p=head; p; p=p->next) {
2228 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
2231 for (p=head; p; p=p->next) {
2232 if (DL_FDPIC && p->loadmap) {
2233 for (i=0; i<p->loadmap->nsegs; i++) {
2234 if (a-p->loadmap->segs[i].p_vaddr
2235 < p->loadmap->segs[i].p_memsz)
2240 size_t phcnt = p->phnum;
2241 size_t entsz = p->phentsize;
2242 size_t base = (size_t)p->base;
2243 for (; phcnt--; ph=(void *)((char *)ph+entsz)) {
2244 if (ph->p_type != PT_LOAD) continue;
2245 if (a-base-ph->p_vaddr < ph->p_memsz)
2248 if (a-(size_t)p->map < p->map_len)
2255 static void *do_dlsym(struct dso *p, const char *s, void *ra)
2258 if (p == head || p == RTLD_DEFAULT) {
2260 } else if (p == RTLD_NEXT) {
2261 p = addr2dso((size_t)ra);
2264 } else if (__dl_invalid_handle(p)) {
2268 struct symdef def = find_sym2(p, s, 0, use_deps);
2270 error("Symbol not found: %s", s);
2273 if ((def.sym->st_info&0xf) == STT_TLS)
2274 return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value-DTP_OFFSET});
2275 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
2276 return def.dso->funcdescs + (def.sym - def.dso->syms);
2277 return laddr(def.dso, def.sym->st_value);
2280 int dladdr(const void *addr_arg, Dl_info *info)
2282 size_t addr = (size_t)addr_arg;
2288 size_t besterr = -1;
2290 pthread_rwlock_rdlock(&lock);
2292 pthread_rwlock_unlock(&lock);
2297 strings = p->strings;
2298 nsym = count_syms(p);
2301 size_t idx = (addr-(size_t)p->funcdescs)
2302 / sizeof(*p->funcdescs);
2303 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
2304 best = (size_t)(p->funcdescs + idx);
2305 bestsym = sym + idx;
2310 if (!best) for (; nsym; nsym--, sym++) {
2312 && (1<<(sym->st_info&0xf) & OK_TYPES)
2313 && (1<<(sym->st_info>>4) & OK_BINDS)) {
2314 size_t symaddr = (size_t)laddr(p, sym->st_value);
2315 if (symaddr > addr || symaddr <= best)
2319 besterr = addr - symaddr;
2320 if (addr == symaddr)
2325 if (best && besterr > bestsym->st_size-1) {
2330 info->dli_fname = p->name;
2331 info->dli_fbase = p->map;
2334 info->dli_sname = 0;
2335 info->dli_saddr = 0;
2339 if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
2340 best = (size_t)(p->funcdescs + (bestsym - p->syms));
2341 info->dli_sname = strings + bestsym->st_name;
2342 info->dli_saddr = (void *)best;
2347 hidden void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
2350 pthread_rwlock_rdlock(&lock);
2351 res = do_dlsym(p, s, ra);
2352 pthread_rwlock_unlock(&lock);
2356 hidden void *__dlsym_redir_time64(void *restrict p, const char *restrict s, void *restrict ra)
2359 const char *suffix, *suffix2 = "";
2362 /* Map the symbol name to a time64 version of itself according to the
2363 * pattern used for naming the redirected time64 symbols. */
2364 size_t l = strnlen(s, sizeof redir);
2365 if (l<4 || l==sizeof redir) goto no_redir;
2366 if (s[l-2]=='_' && s[l-1]=='r') {
2370 if (l<4) goto no_redir;
2371 if (!strcmp(s+l-4, "time")) suffix = "64";
2372 else suffix = "_time64";
2374 /* Use the presence of the remapped symbol name in libc to determine
2375 * whether it's one that requires time64 redirection; replace if so. */
2376 snprintf(redir, sizeof redir, "__%.*s%s%s", (int)l, s, suffix, suffix2);
2377 if (find_sym(&ldso, redir, 1).sym) s = redir;
2380 return __dlsym(p, s, ra);
2383 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
2385 struct dso *current;
2386 struct dl_phdr_info info;
2388 for(current = head; current;) {
2389 info.dlpi_addr = (uintptr_t)current->base;
2390 info.dlpi_name = current->name;
2391 info.dlpi_phdr = current->phdr;
2392 info.dlpi_phnum = current->phnum;
2393 info.dlpi_adds = gencnt;
2395 info.dlpi_tls_modid = current->tls_id;
2396 info.dlpi_tls_data = !current->tls_id ? 0 :
2397 __tls_get_addr((tls_mod_off_t[]){current->tls_id,0});
2399 ret = (callback)(&info, sizeof (info), data);
2401 if (ret != 0) break;
2403 pthread_rwlock_rdlock(&lock);
2404 current = current->next;
2405 pthread_rwlock_unlock(&lock);
2410 static void error_impl(const char *fmt, ...)
2415 vdprintf(2, fmt, ap);
2421 __dl_vseterr(fmt, ap);
2425 static void error_noop(const char *fmt, ...)