src/ldso/dynlink.c

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <stdarg.h>
   5 #include <stddef.h>
   6 #include <string.h>
   7 #include <unistd.h>
   8 #include <stdint.h>
   9 #include <elf.h>
  10 #include <sys/mman.h>
  11 #include <limits.h>
  12 #include <fcntl.h>
  13 #include <sys/stat.h>
  14 #include <errno.h>
  15 #include <link.h>
  16 #include <setjmp.h>
  17 #include <pthread.h>
  18 #include <ctype.h>
  19 #include <dlfcn.h>
  20 #include "pthread_impl.h"
  21 #include "libc.h"
  22 #include "dynlink.h"
  23
  24 static void error(const char *, ...);
  25
  26 #ifdef SHARED
  27
  28 #define MAXP2(a,b) (-(-(a)&-(b)))
  29 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  30
  31 struct debug {
  32         int ver;
  33         void *head;
  34         void (*bp)(void);
  35         int state;
  36         void *base;
  37 };
  38
  39 struct td_index {
  40         size_t args[2];
  41         struct td_index *next;
  42 };
  43
  44 struct dso {
  45         unsigned char *base;
  46         char *name;
  47         size_t *dynv;
  48         struct dso *next, *prev;
  49
  50         Phdr *phdr;
  51         int phnum;
  52         size_t phentsize;
  53         int refcnt;
  54         Sym *syms;
  55         uint32_t *hashtab;
  56         uint32_t *ghashtab;
  57         int16_t *versym;
  58         char *strings;
  59         unsigned char *map;
  60         size_t map_len;
  61         dev_t dev;
  62         ino_t ino;
  63         signed char global;
  64         char relocated;
  65         char constructed;
  66         char kernel_mapped;
  67         struct dso **deps, *needed_by;
  68         char *rpath_orig, *rpath;
  69         void *tls_image;
  70         size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
  71         size_t relro_start, relro_end;
  72         void **new_dtv;
  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;
  77         char *shortname;
  78         char buf[];
  79 };
  80
  81 struct symdef {
  82         Sym *sym;
  83         struct dso *dso;
  84 };
  85
  86 int __init_tp(void *);
  87 void __init_libc(char **, char *);
  88
  89 const char *__libc_get_version(void);
  90
  91 static struct builtin_tls {
  92         char c;
  93         struct pthread pt;
  94         void *space[16];
  95 } builtin_tls[1];
  96 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
  97
  98 #define ADDEND_LIMIT 4096
  99 static size_t *saved_addends, *apply_addends_to;
 100
 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;
 105 static int runtime;
 106 static int ldd_mode;
 107 static int ldso_fail;
 108 static int noload;
 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 };
 115
 116 struct debug *_dl_debug_addr = &debug;
 117
 118 static int dl_strcmp(const char *l, const char *r)
 119 {
 120         for (; *l==*r && *l; l++, r++);
 121         return *(unsigned char *)l - *(unsigned char *)r;
 122 }
 123 #define strcmp(l,r) dl_strcmp(l,r)
 124
 125 /* Compute load address for a virtual address in a given dso. */
 126 #define laddr(p, v) (void *)((p)->base + (v))
 127
 128 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 129 {
 130         size_t i;
 131         for (i=0; i<cnt; i++) a[i] = 0;
 132         for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
 133                 a[0] |= 1UL<<v[0];
 134                 a[v[0]] = v[1];
 135         }
 136 }
 137
 138 static int search_vec(size_t *v, size_t *r, size_t key)
 139 {
 140         for (; v[0]!=key; v+=2)
 141                 if (!v[0]) return 0;
 142         *r = v[1];
 143         return 1;
 144 }
 145
 146 static uint32_t sysv_hash(const char *s0)
 147 {
 148         const unsigned char *s = (void *)s0;
 149         uint_fast32_t h = 0;
 150         while (*s) {
 151                 h = 16*h + *s++;
 152                 h ^= h>>24 & 0xf0;
 153         }
 154         return h & 0xfffffff;
 155 }
 156
 157 static uint32_t gnu_hash(const char *s0)
 158 {
 159         const unsigned char *s = (void *)s0;
 160         uint_fast32_t h = 5381;
 161         for (; *s; s++)
 162                 h += h*32 + *s;
 163         return h;
 164 }
 165
 166 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 167 {
 168         size_t i;
 169         Sym *syms = dso->syms;
 170         uint32_t *hashtab = dso->hashtab;
 171         char *strings = dso->strings;
 172         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 173                 if ((!dso->versym || dso->versym[i] >= 0)
 174                     && (!strcmp(s, strings+syms[i].st_name)))
 175                         return syms+i;
 176         }
 177         return 0;
 178 }
 179
 180 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
 181 {
 182         uint32_t nbuckets = hashtab[0];
 183         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 184         uint32_t i = buckets[h1 % nbuckets];
 185
 186         if (!i) return 0;
 187
 188         uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
 189
 190         for (h1 |= 1; ; i++) {
 191                 uint32_t h2 = *hashval++;
 192                 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
 193                     && !strcmp(s, dso->strings + dso->syms[i].st_name))
 194                         return dso->syms+i;
 195                 if (h2 & 1) break;
 196         }
 197
 198         return 0;
 199 }
 200
 201 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
 202 {
 203         const size_t *bloomwords = (const void *)(hashtab+4);
 204         size_t f = bloomwords[fofs & (hashtab[2]-1)];
 205         if (!(f & fmask)) return 0;
 206
 207         f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
 208         if (!(f & 1)) return 0;
 209
 210         return gnu_lookup(h1, hashtab, dso, s);
 211 }
 212
 213 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 214 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 215
 216 #ifndef ARCH_SYM_REJECT_UND
 217 #define ARCH_SYM_REJECT_UND(s) 0
 218 #endif
 219
 220 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 221 {
 222         uint32_t h = 0, gh, gho, *ght;
 223         size_t ghm = 0;
 224         struct symdef def = {0};
 225         for (; dso; dso=dso->next) {
 226                 Sym *sym;
 227                 if (!dso->global) continue;
 228                 if ((ght = dso->ghashtab)) {
 229                         if (!ghm) {
 230                                 gh = gnu_hash(s);
 231                                 int maskbits = 8 * sizeof ghm;
 232                                 gho = gh / maskbits;
 233                                 ghm = 1ul << gh % maskbits;
 234                         }
 235                         sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
 236                 } else {
 237                         if (!h) h = sysv_hash(s);
 238                         sym = sysv_lookup(s, h, dso);
 239                 }
 240                 if (!sym) continue;
 241                 if (!sym->st_shndx)
 242                         if (need_def || (sym->st_info&0xf) == STT_TLS
 243                             || ARCH_SYM_REJECT_UND(sym))
 244                                 continue;
 245                 if (!sym->st_value)
 246                         if ((sym->st_info&0xf) != STT_TLS)
 247                                 continue;
 248                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 249                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 250
 251                 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
 252                 def.sym = sym;
 253                 def.dso = dso;
 254                 if (sym->st_info>>4 == STB_GLOBAL) break;
 255         }
 256         return def;
 257 }
 258
 259 __attribute__((__visibility__("hidden")))
 260 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
 261
 262 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 263 {
 264         unsigned char *base = dso->base;
 265         Sym *syms = dso->syms;
 266         char *strings = dso->strings;
 267         Sym *sym;
 268         const char *name;
 269         void *ctx;
 270         int type;
 271         int sym_index;
 272         struct symdef def;
 273         size_t *reloc_addr;
 274         size_t sym_val;
 275         size_t tls_val;
 276         size_t addend;
 277         int skip_relative = 0, reuse_addends = 0, save_slot = 0;
 278
 279         if (dso == &ldso) {
 280                 /* Only ldso's REL table needs addend saving/reuse. */
 281                 if (rel == apply_addends_to)
 282                         reuse_addends = 1;
 283                 skip_relative = 1;
 284         }
 285
 286         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 287                 if (skip_relative && IS_RELATIVE(rel[1])) continue;
 288                 type = R_TYPE(rel[1]);
 289                 if (type == REL_NONE) continue;
 290                 sym_index = R_SYM(rel[1]);
 291                 reloc_addr = laddr(dso, rel[0]);
 292                 if (sym_index) {
 293                         sym = syms + sym_index;
 294                         name = strings + sym->st_name;
 295                         ctx = type==REL_COPY ? head->next : head;
 296                         def = find_sym(ctx, name, type==REL_PLT);
 297                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 298                             || sym->st_info>>4 != STB_WEAK)) {
 299                                 error("Error relocating %s: %s: symbol not found",
 300                                         dso->name, name);
 301                                 if (runtime) longjmp(*rtld_fail, 1);
 302                                 continue;
 303                         }
 304                 } else {
 305                         sym = 0;
 306                         def.sym = 0;
 307                         def.dso = dso;
 308                 }
 309
 310                 if (stride > 2) {
 311                         addend = rel[2];
 312                 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
 313                         addend = 0;
 314                 } else if (reuse_addends) {
 315                         /* Save original addend in stage 2 where the dso
 316                          * chain consists of just ldso; otherwise read back
 317                          * saved addend since the inline one was clobbered. */
 318                         if (head==&ldso)
 319                                 saved_addends[save_slot] = *reloc_addr;
 320                         addend = saved_addends[save_slot++];
 321                 } else {
 322                         addend = *reloc_addr;
 323                 }
 324
 325                 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
 326                 tls_val = def.sym ? def.sym->st_value : 0;
 327
 328                 switch(type) {
 329                 case REL_NONE:
 330                         break;
 331                 case REL_OFFSET:
 332                         addend -= (size_t)reloc_addr;
 333                 case REL_SYMBOLIC:
 334                 case REL_GOT:
 335                 case REL_PLT:
 336                         *reloc_addr = sym_val + addend;
 337                         break;
 338                 case REL_RELATIVE:
 339                         *reloc_addr = (size_t)base + addend;
 340                         break;
 341                 case REL_SYM_OR_REL:
 342                         if (sym) *reloc_addr = sym_val + addend;
 343                         else *reloc_addr = (size_t)base + addend;
 344                         break;
 345                 case REL_COPY:
 346                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 347                         break;
 348                 case REL_OFFSET32:
 349                         *(uint32_t *)reloc_addr = sym_val + addend
 350                                 - (size_t)reloc_addr;
 351                         break;
 352                 case REL_DTPMOD:
 353                         *reloc_addr = def.dso->tls_id;
 354                         break;
 355                 case REL_DTPOFF:
 356                         *reloc_addr = tls_val + addend - DTP_OFFSET;
 357                         break;
 358 #ifdef TLS_ABOVE_TP
 359                 case REL_TPOFF:
 360                         *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend;
 361                         break;
 362 #else
 363                 case REL_TPOFF:
 364                         *reloc_addr = tls_val - def.dso->tls_offset + addend;
 365                         break;
 366                 case REL_TPOFF_NEG:
 367                         *reloc_addr = def.dso->tls_offset - tls_val + addend;
 368                         break;
 369 #endif
 370                 case REL_TLSDESC:
 371                         if (stride<3) addend = reloc_addr[1];
 372                         if (runtime && def.dso->tls_id >= static_tls_cnt) {
 373                                 struct td_index *new = malloc(sizeof *new);
 374                                 if (!new) {
 375                                         error(
 376                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 377                                         dso->name, sym ? name : "(local)" );
 378                                         longjmp(*rtld_fail, 1);
 379                                 }
 380                                 new->next = dso->td_index;
 381                                 dso->td_index = new;
 382                                 new->args[0] = def.dso->tls_id;
 383                                 new->args[1] = tls_val + addend;
 384                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 385                                 reloc_addr[1] = (size_t)new;
 386                         } else {
 387                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 388 #ifdef TLS_ABOVE_TP
 389                                 reloc_addr[1] = tls_val + def.dso->tls_offset
 390                                         + TPOFF_K + addend;
 391 #else
 392                                 reloc_addr[1] = tls_val - def.dso->tls_offset
 393                                         + addend;
 394 #endif
 395                         }
 396                         break;
 397                 default:
 398                         error("Error relocating %s: unsupported relocation type %d",
 399                                 dso->name, type);
 400                         if (runtime) longjmp(*rtld_fail, 1);
 401                         continue;
 402                 }
 403         }
 404 }
 405
 406 /* A huge hack: to make up for the wastefulness of shared libraries
 407  * needing at least a page of dirty memory even if they have no global
 408  * data, we reclaim the gaps at the beginning and end of writable maps
 409  * and "donate" them to the heap by setting up minimal malloc
 410  * structures and then freeing them. */
 411
 412 static void reclaim(struct dso *dso, size_t start, size_t end)
 413 {
 414         size_t *a, *z;
 415         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 416         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 417         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 418         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 419         if (start>end || end-start < 4*sizeof(size_t)) return;
 420         a = laddr(dso, start);
 421         z = laddr(dso, end);
 422         a[-2] = 1;
 423         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 424         z[1] = 1;
 425         free(a);
 426 }
 427
 428 static void reclaim_gaps(struct dso *dso)
 429 {
 430         Phdr *ph = dso->phdr;
 431         size_t phcnt = dso->phnum;
 432
 433         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 434                 if (ph->p_type!=PT_LOAD) continue;
 435                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 436                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 437                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 438                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 439         }
 440 }
 441
 442 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
 443 {
 444         char *q = mmap(p, n, prot, flags, fd, off);
 445         if (q != MAP_FAILED || errno != EINVAL) return q;
 446         /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
 447         if (flags & MAP_ANONYMOUS) {
 448                 memset(p, 0, n);
 449                 return p;
 450         }
 451         ssize_t r;
 452         if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
 453         for (q=p; n; q+=r, off+=r, n-=r) {
 454                 r = read(fd, q, n);
 455                 if (r < 0 && errno != EINTR) return MAP_FAILED;
 456                 if (!r) {
 457                         memset(q, 0, n);
 458                         break;
 459                 }
 460         }
 461         return p;
 462 }
 463
 464 static void *map_library(int fd, struct dso *dso)
 465 {
 466         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 467         void *allocated_buf=0;
 468         size_t phsize;
 469         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 470         size_t this_min, this_max;
 471         off_t off_start;
 472         Ehdr *eh;
 473         Phdr *ph, *ph0;
 474         unsigned prot;
 475         unsigned char *map=MAP_FAILED, *base;
 476         size_t dyn=0;
 477         size_t tls_image=0;
 478         size_t i;
 479
 480         ssize_t l = read(fd, buf, sizeof buf);
 481         eh = buf;
 482         if (l<0) return 0;
 483         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 484                 goto noexec;
 485         phsize = eh->e_phentsize * eh->e_phnum;
 486         if (phsize > sizeof buf - sizeof *eh) {
 487                 allocated_buf = malloc(phsize);
 488                 if (!allocated_buf) return 0;
 489                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 490                 if (l < 0) goto error;
 491                 if (l != phsize) goto noexec;
 492                 ph = ph0 = allocated_buf;
 493         } else if (eh->e_phoff + phsize > l) {
 494                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 495                 if (l < 0) goto error;
 496                 if (l != phsize) goto noexec;
 497                 ph = ph0 = (void *)(buf + 1);
 498         } else {
 499                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 500         }
 501         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 502                 if (ph->p_type == PT_DYNAMIC) {
 503                         dyn = ph->p_vaddr;
 504                 } else if (ph->p_type == PT_TLS) {
 505                         tls_image = ph->p_vaddr;
 506                         dso->tls_align = ph->p_align;
 507                         dso->tls_len = ph->p_filesz;
 508                         dso->tls_size = ph->p_memsz;
 509                 } else if (ph->p_type == PT_GNU_RELRO) {
 510                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 511                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 512                 }
 513                 if (ph->p_type != PT_LOAD) continue;
 514                 if (ph->p_vaddr < addr_min) {
 515                         addr_min = ph->p_vaddr;
 516                         off_start = ph->p_offset;
 517                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 518                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 519                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 520                 }
 521                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 522                         addr_max = ph->p_vaddr+ph->p_memsz;
 523                 }
 524         }
 525         if (!dyn) goto noexec;
 526         addr_max += PAGE_SIZE-1;
 527         addr_max &= -PAGE_SIZE;
 528         addr_min &= -PAGE_SIZE;
 529         off_start &= -PAGE_SIZE;
 530         map_len = addr_max - addr_min + off_start;
 531         /* The first time, we map too much, possibly even more than
 532          * the length of the file. This is okay because we will not
 533          * use the invalid part; we just need to reserve the right
 534          * amount of virtual address space to map over later. */
 535         map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
 536         if (map==MAP_FAILED) goto error;
 537         /* If the loaded file is not relocatable and the requested address is
 538          * not available, then the load operation must fail. */
 539         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 540                 errno = EBUSY;
 541                 goto error;
 542         }
 543         base = map - addr_min;
 544         dso->phdr = 0;
 545         dso->phnum = 0;
 546         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 547                 if (ph->p_type != PT_LOAD) continue;
 548                 /* Check if the programs headers are in this load segment, and
 549                  * if so, record the address for use by dl_iterate_phdr. */
 550                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 551                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 552                         dso->phdr = (void *)(base + ph->p_vaddr
 553                                 + (eh->e_phoff-ph->p_offset));
 554                         dso->phnum = eh->e_phnum;
 555                         dso->phentsize = eh->e_phentsize;
 556                 }
 557                 /* Reuse the existing mapping for the lowest-address LOAD */
 558                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
 559                 this_min = ph->p_vaddr & -PAGE_SIZE;
 560                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 561                 off_start = ph->p_offset & -PAGE_SIZE;
 562                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 563                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 564                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 565                 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 566                         goto error;
 567                 if (ph->p_memsz > ph->p_filesz) {
 568                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 569                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 570                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 571                         if (pgbrk-(size_t)base < this_max && mmap_fixed((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
 572                                 goto error;
 573                 }
 574         }
 575         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 576                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 577                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
 578                             && errno != ENOSYS)
 579                                 goto error;
 580                         break;
 581                 }
 582         dso->map = map;
 583         dso->map_len = map_len;
 584         dso->base = base;
 585         dso->dynv = (void *)(base+dyn);
 586         if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
 587         if (!runtime) reclaim_gaps(dso);
 588         free(allocated_buf);
 589         return map;
 590 noexec:
 591         errno = ENOEXEC;
 592 error:
 593         if (map!=MAP_FAILED) munmap(map, map_len);
 594         free(allocated_buf);
 595         return 0;
 596 }
 597
 598 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 599 {
 600         size_t l;
 601         int fd;
 602         for (;;) {
 603                 s += strspn(s, ":\n");
 604                 l = strcspn(s, ":\n");
 605                 if (l-1 >= INT_MAX) return -1;
 606                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
 607                         if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 608                         switch (errno) {
 609                         case ENOENT:
 610                         case ENOTDIR:
 611                         case EACCES:
 612                         case ENAMETOOLONG:
 613                                 break;
 614                         default:
 615                                 /* Any negative value but -1 will inhibit
 616                                  * futher path search. */
 617                                 return -2;
 618                         }
 619                 }
 620                 s += l;
 621         }
 622 }
 623
 624 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 625 {
 626         size_t n, l;
 627         const char *s, *t, *origin;
 628         char *d;
 629         if (p->rpath || !p->rpath_orig) return 0;
 630         if (!strchr(p->rpath_orig, '$')) {
 631                 p->rpath = p->rpath_orig;
 632                 return 0;
 633         }
 634         n = 0;
 635         s = p->rpath_orig;
 636         while ((t=strchr(s, '$'))) {
 637                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 638                         return 0;
 639                 s = t+1;
 640                 n++;
 641         }
 642         if (n > SSIZE_MAX/PATH_MAX) return 0;
 643
 644         if (p->kernel_mapped) {
 645                 /* $ORIGIN searches cannot be performed for the main program
 646                  * when it is suid/sgid/AT_SECURE. This is because the
 647                  * pathname is under the control of the caller of execve.
 648                  * For libraries, however, $ORIGIN can be processed safely
 649                  * since the library's pathname came from a trusted source
 650                  * (either system paths or a call to dlopen). */
 651                 if (libc.secure)
 652                         return 0;
 653                 l = readlink("/proc/self/exe", buf, buf_size);
 654                 if (l == -1) switch (errno) {
 655                 case ENOENT:
 656                 case ENOTDIR:
 657                 case EACCES:
 658                         break;
 659                 default:
 660                         return -1;
 661                 }
 662                 if (l >= buf_size)
 663                         return 0;
 664                 buf[l] = 0;
 665                 origin = buf;
 666         } else {
 667                 origin = p->name;
 668         }
 669         t = strrchr(origin, '/');
 670         l = t ? t-origin : 0;
 671         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 672         if (!p->rpath) return -1;
 673
 674         d = p->rpath;
 675         s = p->rpath_orig;
 676         while ((t=strchr(s, '$'))) {
 677                 memcpy(d, s, t-s);
 678                 d += t-s;
 679                 memcpy(d, origin, l);
 680                 d += l;
 681                 /* It was determined previously that the '$' is followed
 682                  * either by "ORIGIN" or "{ORIGIN}". */
 683                 s = t + 7 + 2*(t[1]=='{');
 684         }
 685         strcpy(d, s);
 686         return 0;
 687 }
 688
 689 static void decode_dyn(struct dso *p)
 690 {
 691         size_t dyn[DYN_CNT];
 692         decode_vec(p->dynv, dyn, DYN_CNT);
 693         p->syms = laddr(p, dyn[DT_SYMTAB]);
 694         p->strings = laddr(p, dyn[DT_STRTAB]);
 695         if (dyn[0]&(1<<DT_HASH))
 696                 p->hashtab = laddr(p, dyn[DT_HASH]);
 697         if (dyn[0]&(1<<DT_RPATH))
 698                 p->rpath_orig = p->strings + dyn[DT_RPATH];
 699         if (dyn[0]&(1<<DT_RUNPATH))
 700                 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
 701         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 702                 p->ghashtab = laddr(p, *dyn);
 703         if (search_vec(p->dynv, dyn, DT_VERSYM))
 704                 p->versym = laddr(p, *dyn);
 705 }
 706
 707 static struct dso *load_library(const char *name, struct dso *needed_by)
 708 {
 709         char buf[2*NAME_MAX+2];
 710         const char *pathname;
 711         unsigned char *map;
 712         struct dso *p, temp_dso = {0};
 713         int fd;
 714         struct stat st;
 715         size_t alloc_size;
 716         int n_th = 0;
 717         int is_self = 0;
 718
 719         if (!*name) {
 720                 errno = EINVAL;
 721                 return 0;
 722         }
 723
 724         /* Catch and block attempts to reload the implementation itself */
 725         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 726                 static const char *rp, reserved[] =
 727                         "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
 728                 char *z = strchr(name, '.');
 729                 if (z) {
 730                         size_t l = z-name;
 731                         for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
 732                         if (*rp) {
 733                                 if (ldd_mode) {
 734                                         /* Track which names have been resolved
 735                                          * and only report each one once. */
 736                                         static unsigned reported;
 737                                         unsigned mask = 1U<<(rp-reserved);
 738                                         if (!(reported & mask)) {
 739                                                 reported |= mask;
 740                                                 dprintf(1, "\t%s => %s (%p)\n",
 741                                                         name, ldso.name,
 742                                                         ldso.base);
 743                                         }
 744                                 }
 745                                 is_self = 1;
 746                         }
 747                 }
 748         }
 749         if (!strcmp(name, ldso.name)) is_self = 1;
 750         if (is_self) {
 751                 if (!ldso.prev) {
 752                         tail->next = &ldso;
 753                         ldso.prev = tail;
 754                         tail = ldso.next ? ldso.next : &ldso;
 755                 }
 756                 return &ldso;
 757         }
 758         if (strchr(name, '/')) {
 759                 pathname = name;
 760                 fd = open(name, O_RDONLY|O_CLOEXEC);
 761         } else {
 762                 /* Search for the name to see if it's already loaded */
 763                 for (p=head->next; p; p=p->next) {
 764                         if (p->shortname && !strcmp(p->shortname, name)) {
 765                                 p->refcnt++;
 766                                 return p;
 767                         }
 768                 }
 769                 if (strlen(name) > NAME_MAX) return 0;
 770                 fd = -1;
 771                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 772                 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
 773                         if (fixup_rpath(p, buf, sizeof buf) < 0)
 774                                 fd = -2; /* Inhibit further search. */
 775                         if (p->rpath)
 776                                 fd = path_open(name, p->rpath, buf, sizeof buf);
 777                 }
 778                 if (fd == -1) {
 779                         if (!sys_path) {
 780                                 char *prefix = 0;
 781                                 size_t prefix_len;
 782                                 if (ldso.name[0]=='/') {
 783                                         char *s, *t, *z;
 784                                         for (s=t=z=ldso.name; *s; s++)
 785                                                 if (*s=='/') z=t, t=s;
 786                                         prefix_len = z-ldso.name;
 787                                         if (prefix_len < PATH_MAX)
 788                                                 prefix = ldso.name;
 789                                 }
 790                                 if (!prefix) {
 791                                         prefix = "";
 792                                         prefix_len = 0;
 793                                 }
 794                                 char etc_ldso_path[prefix_len + 1
 795                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
 796                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
 797                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 798                                         (int)prefix_len, prefix);
 799                                 FILE *f = fopen(etc_ldso_path, "rbe");
 800                                 if (f) {
 801                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
 802                                                 free(sys_path);
 803                                                 sys_path = "";
 804                                         }
 805                                         fclose(f);
 806                                 } else if (errno != ENOENT) {
 807                                         sys_path = "";
 808                                 }
 809                         }
 810                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
 811                         fd = path_open(name, sys_path, buf, sizeof buf);
 812                 }
 813                 pathname = buf;
 814         }
 815         if (fd < 0) return 0;
 816         if (fstat(fd, &st) < 0) {
 817                 close(fd);
 818                 return 0;
 819         }
 820         for (p=head->next; p; p=p->next) {
 821                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
 822                         /* If this library was previously loaded with a
 823                          * pathname but a search found the same inode,
 824                          * setup its shortname so it can be found by name. */
 825                         if (!p->shortname && pathname != name)
 826                                 p->shortname = strrchr(p->name, '/')+1;
 827                         close(fd);
 828                         p->refcnt++;
 829                         return p;
 830                 }
 831         }
 832         map = noload ? 0 : map_library(fd, &temp_dso);
 833         close(fd);
 834         if (!map) return 0;
 835
 836         /* Allocate storage for the new DSO. When there is TLS, this
 837          * storage must include a reservation for all pre-existing
 838          * threads to obtain copies of both the new TLS, and an
 839          * extended DTV capable of storing an additional slot for
 840          * the newly-loaded DSO. */
 841         alloc_size = sizeof *p + strlen(pathname) + 1;
 842         if (runtime && temp_dso.tls_image) {
 843                 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
 844                         + sizeof(void *) * (tls_cnt+3);
 845                 n_th = libc.threads_minus_1 + 1;
 846                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
 847                 else alloc_size += n_th * per_th;
 848         }
 849         p = calloc(1, alloc_size);
 850         if (!p) {
 851                 munmap(map, temp_dso.map_len);
 852                 return 0;
 853         }
 854         memcpy(p, &temp_dso, sizeof temp_dso);
 855         decode_dyn(p);
 856         p->dev = st.st_dev;
 857         p->ino = st.st_ino;
 858         p->refcnt = 1;
 859         p->needed_by = needed_by;
 860         p->name = p->buf;
 861         strcpy(p->name, pathname);
 862         /* Add a shortname only if name arg was not an explicit pathname. */
 863         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
 864         if (p->tls_image) {
 865                 p->tls_id = ++tls_cnt;
 866                 tls_align = MAXP2(tls_align, p->tls_align);
 867 #ifdef TLS_ABOVE_TP
 868                 p->tls_offset = tls_offset + ( (tls_align-1) &
 869                         -(tls_offset + (uintptr_t)p->tls_image) );
 870                 tls_offset += p->tls_size;
 871 #else
 872                 tls_offset += p->tls_size + p->tls_align - 1;
 873                 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
 874                         & (p->tls_align-1);
 875                 p->tls_offset = tls_offset;
 876 #endif
 877                 p->new_dtv = (void *)(-sizeof(size_t) &
 878                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
 879                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
 880         }
 881
 882         tail->next = p;
 883         p->prev = tail;
 884         tail = p;
 885
 886         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
 887
 888         return p;
 889 }
 890
 891 static void load_deps(struct dso *p)
 892 {
 893         size_t i, ndeps=0;
 894         struct dso ***deps = &p->deps, **tmp, *dep;
 895         for (; p; p=p->next) {
 896                 for (i=0; p->dynv[i]; i+=2) {
 897                         if (p->dynv[i] != DT_NEEDED) continue;
 898                         dep = load_library(p->strings + p->dynv[i+1], p);
 899                         if (!dep) {
 900                                 error("Error loading shared library %s: %m (needed by %s)",
 901                                         p->strings + p->dynv[i+1], p->name);
 902                                 if (runtime) longjmp(*rtld_fail, 1);
 903                                 continue;
 904                         }
 905                         if (runtime) {
 906                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
 907                                 if (!tmp) longjmp(*rtld_fail, 1);
 908                                 tmp[ndeps++] = dep;
 909                                 tmp[ndeps] = 0;
 910                                 *deps = tmp;
 911                         }
 912                 }
 913         }
 914 }
 915
 916 static void load_preload(char *s)
 917 {
 918         int tmp;
 919         char *z;
 920         for (z=s; *z; s=z) {
 921                 for (   ; *s && (isspace(*s) || *s==':'); s++);
 922                 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
 923                 tmp = *z;
 924                 *z = 0;
 925                 load_library(s, 0);
 926                 *z = tmp;
 927         }
 928 }
 929
 930 static void make_global(struct dso *p)
 931 {
 932         for (; p; p=p->next) p->global = 1;
 933 }
 934
 935 static void do_mips_relocs(struct dso *p, size_t *got)
 936 {
 937         size_t i, j, rel[2];
 938         unsigned char *base = p->base;
 939         i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
 940         if (p==&ldso) {
 941                 got += i;
 942         } else {
 943                 while (i--) *got++ += (size_t)base;
 944         }
 945         j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
 946         i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
 947         Sym *sym = p->syms + j;
 948         rel[0] = (unsigned char *)got - base;
 949         for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
 950                 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
 951                 do_relocs(p, rel, sizeof rel, 2);
 952         }
 953 }
 954
 955 static void reloc_all(struct dso *p)
 956 {
 957         size_t dyn[DYN_CNT];
 958         for (; p; p=p->next) {
 959                 if (p->relocated) continue;
 960                 decode_vec(p->dynv, dyn, DYN_CNT);
 961                 if (NEED_MIPS_GOT_RELOCS)
 962                         do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
 963                 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
 964                         2+(dyn[DT_PLTREL]==DT_RELA));
 965                 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
 966                 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
 967
 968                 if (head != &ldso && p->relro_start != p->relro_end &&
 969                     mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
 970                     && errno != ENOSYS) {
 971                         error("Error relocating %s: RELRO protection failed: %m",
 972                                 p->name);
 973                         if (runtime) longjmp(*rtld_fail, 1);
 974                 }
 975
 976                 p->relocated = 1;
 977         }
 978 }
 979
 980 static void kernel_mapped_dso(struct dso *p)
 981 {
 982         size_t min_addr = -1, max_addr = 0, cnt;
 983         Phdr *ph = p->phdr;
 984         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
 985                 if (ph->p_type == PT_DYNAMIC) {
 986                         p->dynv = laddr(p, ph->p_vaddr);
 987                 } else if (ph->p_type == PT_GNU_RELRO) {
 988                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
 989                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 990                 }
 991                 if (ph->p_type != PT_LOAD) continue;
 992                 if (ph->p_vaddr < min_addr)
 993                         min_addr = ph->p_vaddr;
 994                 if (ph->p_vaddr+ph->p_memsz > max_addr)
 995                         max_addr = ph->p_vaddr+ph->p_memsz;
 996         }
 997         min_addr &= -PAGE_SIZE;
 998         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
 999         p->map = p->base + min_addr;
1000         p->map_len = max_addr - min_addr;
1001         p->kernel_mapped = 1;
1002 }
1003
1004 static void do_fini()
1005 {
1006         struct dso *p;
1007         size_t dyn[DYN_CNT];
1008         for (p=fini_head; p; p=p->fini_next) {
1009                 if (!p->constructed) continue;
1010                 decode_vec(p->dynv, dyn, DYN_CNT);
1011                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1012                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1013                         size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1014                         while (n--) ((void (*)(void))*--fn)();
1015                 }
1016 #ifndef NO_LEGACY_INITFINI
1017                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1018                         ((void (*)(void))laddr(p, dyn[DT_FINI]))();
1019 #endif
1020         }
1021 }
1022
1023 static void do_init_fini(struct dso *p)
1024 {
1025         size_t dyn[DYN_CNT];
1026         int need_locking = libc.threads_minus_1;
1027         /* Allow recursive calls that arise when a library calls
1028          * dlopen from one of its constructors, but block any
1029          * other threads until all ctors have finished. */
1030         if (need_locking) pthread_mutex_lock(&init_fini_lock);
1031         for (; p; p=p->prev) {
1032                 if (p->constructed) continue;
1033                 p->constructed = 1;
1034                 decode_vec(p->dynv, dyn, DYN_CNT);
1035                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1036                         p->fini_next = fini_head;
1037                         fini_head = p;
1038                 }
1039 #ifndef NO_LEGACY_INITFINI
1040                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1041                         ((void (*)(void))laddr(p, dyn[DT_INIT]))();
1042 #endif
1043                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1044                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1045                         size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1046                         while (n--) ((void (*)(void))*fn++)();
1047                 }
1048                 if (!need_locking && libc.threads_minus_1) {
1049                         need_locking = 1;
1050                         pthread_mutex_lock(&init_fini_lock);
1051                 }
1052         }
1053         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1054 }
1055
1056 static void dl_debug_state(void)
1057 {
1058 }
1059
1060 weak_alias(dl_debug_state, _dl_debug_state);
1061
1062 void __reset_tls()
1063 {
1064         pthread_t self = __pthread_self();
1065         struct dso *p;
1066         for (p=head; p; p=p->next) {
1067                 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
1068                 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
1069                 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
1070                         p->tls_size - p->tls_len);
1071                 if (p->tls_id == (size_t)self->dtv[0]) break;
1072         }
1073 }
1074
1075 void *__copy_tls(unsigned char *mem)
1076 {
1077         pthread_t td;
1078         struct dso *p;
1079         void **dtv;
1080
1081 #ifdef TLS_ABOVE_TP
1082         dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1);
1083
1084         mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1085         td = (pthread_t)mem;
1086         mem += sizeof(struct pthread);
1087
1088         for (p=head; p; p=p->next) {
1089                 if (!p->tls_id) continue;
1090                 dtv[p->tls_id] = mem + p->tls_offset;
1091                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1092         }
1093 #else
1094         dtv = (void **)mem;
1095
1096         mem += libc.tls_size - sizeof(struct pthread);
1097         mem -= (uintptr_t)mem & (tls_align-1);
1098         td = (pthread_t)mem;
1099
1100         for (p=head; p; p=p->next) {
1101                 if (!p->tls_id) continue;
1102                 dtv[p->tls_id] = mem - p->tls_offset;
1103                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1104         }
1105 #endif
1106         dtv[0] = (void *)tls_cnt;
1107         td->dtv = td->dtv_copy = dtv;
1108         return td;
1109 }
1110
1111 __attribute__((__visibility__("hidden")))
1112 void *__tls_get_new(size_t *v)
1113 {
1114         pthread_t self = __pthread_self();
1115
1116         /* Block signals to make accessing new TLS async-signal-safe */
1117         sigset_t set;
1118         __block_all_sigs(&set);
1119         if (v[0]<=(size_t)self->dtv[0]) {
1120                 __restore_sigs(&set);
1121                 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1122         }
1123
1124         /* This is safe without any locks held because, if the caller
1125          * is able to request the Nth entry of the DTV, the DSO list
1126          * must be valid at least that far out and it was synchronized
1127          * at program startup or by an already-completed call to dlopen. */
1128         struct dso *p;
1129         for (p=head; p->tls_id != v[0]; p=p->next);
1130
1131         /* Get new DTV space from new DSO if needed */
1132         if (v[0] > (size_t)self->dtv[0]) {
1133                 void **newdtv = p->new_dtv +
1134                         (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
1135                 memcpy(newdtv, self->dtv,
1136                         ((size_t)self->dtv[0]+1) * sizeof(void *));
1137                 newdtv[0] = (void *)v[0];
1138                 self->dtv = self->dtv_copy = newdtv;
1139         }
1140
1141         /* Get new TLS memory from all new DSOs up to the requested one */
1142         unsigned char *mem;
1143         for (p=head; ; p=p->next) {
1144                 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1145                 mem = p->new_tls + (p->tls_size + p->tls_align)
1146                         * a_fetch_add(&p->new_tls_idx,1);
1147                 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1148                         & (p->tls_align-1);
1149                 self->dtv[p->tls_id] = mem;
1150                 memcpy(mem, p->tls_image, p->tls_len);
1151                 if (p->tls_id == v[0]) break;
1152         }
1153         __restore_sigs(&set);
1154         return mem + v[1] + DTP_OFFSET;
1155 }
1156
1157 static void update_tls_size()
1158 {
1159         libc.tls_size = ALIGN(
1160                 (1+tls_cnt) * sizeof(void *) +
1161                 tls_offset +
1162                 sizeof(struct pthread) +
1163                 tls_align * 2,
1164         tls_align);
1165 }
1166
1167 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1168  * following stage 2 and stage 3 functions via primitive symbolic lookup
1169  * since it does not have access to their addresses to begin with. */
1170
1171 /* Stage 2 of the dynamic linker is called after relative relocations
1172  * have been processed. It can make function calls to static functions
1173  * and access string literals and static data, but cannot use extern
1174  * symbols. Its job is to perform symbolic relocations on the dynamic
1175  * linker itself, but some of the relocations performed may need to be
1176  * replaced later due to copy relocations in the main program. */
1177
1178 void __dls2(unsigned char *base, size_t *sp)
1179 {
1180         Ehdr *ehdr = (void *)base;
1181         ldso.base = base;
1182         ldso.name = ldso.shortname = "libc.so";
1183         ldso.global = 1;
1184         ldso.phnum = ehdr->e_phnum;
1185         ldso.phdr = (void *)(base + ehdr->e_phoff);
1186         ldso.phentsize = ehdr->e_phentsize;
1187         kernel_mapped_dso(&ldso);
1188         decode_dyn(&ldso);
1189
1190         /* Prepare storage for to save clobbered REL addends so they
1191          * can be reused in stage 3. There should be very few. If
1192          * something goes wrong and there are a huge number, abort
1193          * instead of risking stack overflow. */
1194         size_t dyn[DYN_CNT];
1195         decode_vec(ldso.dynv, dyn, DYN_CNT);
1196         size_t *rel = laddr(&ldso, dyn[DT_REL]);
1197         size_t rel_size = dyn[DT_RELSZ];
1198         size_t symbolic_rel_cnt = 0;
1199         apply_addends_to = rel;
1200         for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1201                 if (!IS_RELATIVE(rel[1])) symbolic_rel_cnt++;
1202         if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1203         size_t addends[symbolic_rel_cnt+1];
1204         saved_addends = addends;
1205
1206         head = &ldso;
1207         reloc_all(&ldso);
1208
1209         ldso.relocated = 0;
1210
1211         /* Call dynamic linker stage-3, __dls3, looking it up
1212          * symbolically as a barrier against moving the address
1213          * load across the above relocation processing. */
1214         struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1215         ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1216 }
1217
1218 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1219  * fully functional. Its job is to load (if not already loaded) and
1220  * process dependencies and relocations for the main application and
1221  * transfer control to its entry point. */
1222
1223 _Noreturn void __dls3(size_t *sp)
1224 {
1225         static struct dso app, vdso;
1226         size_t aux[AUX_CNT], *auxv;
1227         size_t i;
1228         char *env_preload=0;
1229         size_t vdso_base;
1230         int argc = *sp;
1231         char **argv = (void *)(sp+1);
1232         char **argv_orig = argv;
1233         char **envp = argv+argc+1;
1234
1235         /* Find aux vector just past environ[] and use it to initialize
1236          * global data that may be needed before we can make syscalls. */
1237         __environ = envp;
1238         for (i=argc+1; argv[i]; i++);
1239         libc.auxv = auxv = (void *)(argv+i+1);
1240         decode_vec(auxv, aux, AUX_CNT);
1241         __hwcap = aux[AT_HWCAP];
1242         libc.page_size = aux[AT_PAGESZ];
1243         libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1244                 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1245
1246         /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1247          * use during dynamic linking. If possible it will also serve as the
1248          * thread pointer at runtime. */
1249         libc.tls_size = sizeof builtin_tls;
1250         if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1251                 a_crash();
1252         }
1253
1254         /* Only trust user/env if kernel says we're not suid/sgid */
1255         if (!libc.secure) {
1256                 env_path = getenv("LD_LIBRARY_PATH");
1257                 env_preload = getenv("LD_PRELOAD");
1258         }
1259
1260         /* If the main program was already loaded by the kernel,
1261          * AT_PHDR will point to some location other than the dynamic
1262          * linker's program headers. */
1263         if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1264                 size_t interp_off = 0;
1265                 size_t tls_image = 0;
1266                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1267                 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1268                 app.phnum = aux[AT_PHNUM];
1269                 app.phentsize = aux[AT_PHENT];
1270                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1271                         if (phdr->p_type == PT_PHDR)
1272                                 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1273                         else if (phdr->p_type == PT_INTERP)
1274                                 interp_off = (size_t)phdr->p_vaddr;
1275                         else if (phdr->p_type == PT_TLS) {
1276                                 tls_image = phdr->p_vaddr;
1277                                 app.tls_len = phdr->p_filesz;
1278                                 app.tls_size = phdr->p_memsz;
1279                                 app.tls_align = phdr->p_align;
1280                         }
1281                 }
1282                 if (app.tls_size) app.tls_image = laddr(&app, tls_image);
1283                 if (interp_off) ldso.name = laddr(&app, interp_off);
1284                 if ((aux[0] & (1UL<<AT_EXECFN))
1285                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1286                         app.name = (char *)aux[AT_EXECFN];
1287                 else
1288                         app.name = argv[0];
1289                 kernel_mapped_dso(&app);
1290         } else {
1291                 int fd;
1292                 char *ldname = argv[0];
1293                 size_t l = strlen(ldname);
1294                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1295                 argv++;
1296                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1297                         char *opt = argv[0]+2;
1298                         *argv++ = (void *)-1;
1299                         if (!*opt) {
1300                                 break;
1301                         } else if (!memcmp(opt, "list", 5)) {
1302                                 ldd_mode = 1;
1303                         } else if (!memcmp(opt, "library-path", 12)) {
1304                                 if (opt[12]=='=') env_path = opt+13;
1305                                 else if (opt[12]) *argv = 0;
1306                                 else if (*argv) env_path = *argv++;
1307                         } else if (!memcmp(opt, "preload", 7)) {
1308                                 if (opt[7]=='=') env_preload = opt+8;
1309                                 else if (opt[7]) *argv = 0;
1310                                 else if (*argv) env_preload = *argv++;
1311                         } else {
1312                                 argv[0] = 0;
1313                         }
1314                 }
1315                 argv[-1] = (void *)(argc - (argv-argv_orig));
1316                 if (!argv[0]) {
1317                         dprintf(2, "musl libc\n"
1318                                 "Version %s\n"
1319                                 "Dynamic Program Loader\n"
1320                                 "Usage: %s [options] [--] pathname%s\n",
1321                                 __libc_get_version(), ldname,
1322                                 ldd_mode ? "" : " [args]");
1323                         _exit(1);
1324                 }
1325                 fd = open(argv[0], O_RDONLY);
1326                 if (fd < 0) {
1327                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1328                         _exit(1);
1329                 }
1330                 runtime = 1;
1331                 Ehdr *ehdr = (void *)map_library(fd, &app);
1332                 if (!ehdr) {
1333                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1334                         _exit(1);
1335                 }
1336                 runtime = 0;
1337                 close(fd);
1338                 ldso.name = ldname;
1339                 app.name = argv[0];
1340                 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1341                 /* Find the name that would have been used for the dynamic
1342                  * linker had ldd not taken its place. */
1343                 if (ldd_mode) {
1344                         for (i=0; i<app.phnum; i++) {
1345                                 if (app.phdr[i].p_type == PT_INTERP)
1346                                         ldso.name = (void *)(app.base
1347                                                 + app.phdr[i].p_vaddr);
1348                         }
1349                         dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1350                 }
1351         }
1352         if (app.tls_size) {
1353                 app.tls_id = tls_cnt = 1;
1354 #ifdef TLS_ABOVE_TP
1355                 app.tls_offset = 0;
1356                 tls_offset = app.tls_size
1357                         + ( -((uintptr_t)app.tls_image + app.tls_size)
1358                         & (app.tls_align-1) );
1359 #else
1360                 tls_offset = app.tls_offset = app.tls_size
1361                         + ( -((uintptr_t)app.tls_image + app.tls_size)
1362                         & (app.tls_align-1) );
1363 #endif
1364                 tls_align = MAXP2(tls_align, app.tls_align);
1365         }
1366         app.global = 1;
1367         decode_dyn(&app);
1368
1369         /* Attach to vdso, if provided by the kernel */
1370         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1371                 Ehdr *ehdr = (void *)vdso_base;
1372                 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1373                 vdso.phnum = ehdr->e_phnum;
1374                 vdso.phentsize = ehdr->e_phentsize;
1375                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1376                         if (phdr->p_type == PT_DYNAMIC)
1377                                 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1378                         if (phdr->p_type == PT_LOAD)
1379                                 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1380                 }
1381                 vdso.name = "";
1382                 vdso.shortname = "linux-gate.so.1";
1383                 vdso.global = 1;
1384                 vdso.relocated = 1;
1385                 decode_dyn(&vdso);
1386                 vdso.prev = &ldso;
1387                 ldso.next = &vdso;
1388         }
1389
1390         /* Initial dso chain consists only of the app. */
1391         head = tail = &app;
1392
1393         /* Donate unused parts of app and library mapping to malloc */
1394         reclaim_gaps(&app);
1395         reclaim_gaps(&ldso);
1396
1397         /* Load preload/needed libraries, add their symbols to the global
1398          * namespace, and perform all remaining relocations. */
1399         if (env_preload) load_preload(env_preload);
1400         load_deps(&app);
1401         make_global(&app);
1402
1403 #ifndef DYNAMIC_IS_RO
1404         for (i=0; app.dynv[i]; i+=2)
1405                 if (app.dynv[i]==DT_DEBUG)
1406                         app.dynv[i+1] = (size_t)&debug;
1407 #endif
1408
1409         /* The main program must be relocated LAST since it may contin
1410          * copy relocations which depend on libraries' relocations. */
1411         reloc_all(app.next);
1412         reloc_all(&app);
1413
1414         update_tls_size();
1415         if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1416                 void *initial_tls = calloc(libc.tls_size, 1);
1417                 if (!initial_tls) {
1418                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1419                                 argv[0], libc.tls_size);
1420                         _exit(127);
1421                 }
1422                 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1423                         a_crash();
1424                 }
1425         } else {
1426                 size_t tmp_tls_size = libc.tls_size;
1427                 pthread_t self = __pthread_self();
1428                 /* Temporarily set the tls size to the full size of
1429                  * builtin_tls so that __copy_tls will use the same layout
1430                  * as it did for before. Then check, just to be safe. */
1431                 libc.tls_size = sizeof builtin_tls;
1432                 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1433                 libc.tls_size = tmp_tls_size;
1434         }
1435         static_tls_cnt = tls_cnt;
1436
1437         if (ldso_fail) _exit(127);
1438         if (ldd_mode) _exit(0);
1439
1440         /* Switch to runtime mode: any further failures in the dynamic
1441          * linker are a reportable failure rather than a fatal startup
1442          * error. */
1443         runtime = 1;
1444
1445         debug.ver = 1;
1446         debug.bp = dl_debug_state;
1447         debug.head = head;
1448         debug.base = ldso.base;
1449         debug.state = 0;
1450         _dl_debug_state();
1451
1452         __init_libc(envp, argv[0]);
1453         atexit(do_fini);
1454         errno = 0;
1455         do_init_fini(tail);
1456
1457         CRTJMP((void *)aux[AT_ENTRY], argv-1);
1458         for(;;);
1459 }
1460
1461 void *dlopen(const char *file, int mode)
1462 {
1463         struct dso *volatile p, *orig_tail, *next;
1464         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1465         size_t i;
1466         int cs;
1467         jmp_buf jb;
1468
1469         if (!file) return head;
1470
1471         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1472         pthread_rwlock_wrlock(&lock);
1473         __inhibit_ptc();
1474
1475         p = 0;
1476         orig_tls_cnt = tls_cnt;
1477         orig_tls_offset = tls_offset;
1478         orig_tls_align = tls_align;
1479         orig_tail = tail;
1480         noload = mode & RTLD_NOLOAD;
1481
1482         rtld_fail = &jb;
1483         if (setjmp(*rtld_fail)) {
1484                 /* Clean up anything new that was (partially) loaded */
1485                 if (p && p->deps) for (i=0; p->deps[i]; i++)
1486                         if (p->deps[i]->global < 0)
1487                                 p->deps[i]->global = 0;
1488                 for (p=orig_tail->next; p; p=next) {
1489                         next = p->next;
1490                         munmap(p->map, p->map_len);
1491                         while (p->td_index) {
1492                                 void *tmp = p->td_index->next;
1493                                 free(p->td_index);
1494                                 p->td_index = tmp;
1495                         }
1496                         if (p->rpath != p->rpath_orig)
1497                                 free(p->rpath);
1498                         free(p->deps);
1499                         free(p);
1500                 }
1501                 tls_cnt = orig_tls_cnt;
1502                 tls_offset = orig_tls_offset;
1503                 tls_align = orig_tls_align;
1504                 tail = orig_tail;
1505                 tail->next = 0;
1506                 p = 0;
1507                 goto end;
1508         } else p = load_library(file, head);
1509
1510         if (!p) {
1511                 error(noload ?
1512                         "Library %s is not already loaded" :
1513                         "Error loading shared library %s: %m",
1514                         file);
1515                 goto end;
1516         }
1517
1518         /* First load handling */
1519         if (!p->deps) {
1520                 load_deps(p);
1521                 if (p->deps) for (i=0; p->deps[i]; i++)
1522                         if (!p->deps[i]->global)
1523                                 p->deps[i]->global = -1;
1524                 if (!p->global) p->global = -1;
1525                 reloc_all(p);
1526                 if (p->deps) for (i=0; p->deps[i]; i++)
1527                         if (p->deps[i]->global < 0)
1528                                 p->deps[i]->global = 0;
1529                 if (p->global < 0) p->global = 0;
1530         }
1531
1532         if (mode & RTLD_GLOBAL) {
1533                 if (p->deps) for (i=0; p->deps[i]; i++)
1534                         p->deps[i]->global = 1;
1535                 p->global = 1;
1536         }
1537
1538         update_tls_size();
1539         _dl_debug_state();
1540         orig_tail = tail;
1541 end:
1542         __release_ptc();
1543         if (p) gencnt++;
1544         pthread_rwlock_unlock(&lock);
1545         if (p) do_init_fini(orig_tail);
1546         pthread_setcancelstate(cs, 0);
1547         return p;
1548 }
1549
1550 static int invalid_dso_handle(void *h)
1551 {
1552         struct dso *p;
1553         for (p=head; p; p=p->next) if (h==p) return 0;
1554         error("Invalid library handle %p", (void *)h);
1555         return 1;
1556 }
1557
1558 void *__tls_get_addr(size_t *);
1559
1560 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1561 {
1562         size_t i;
1563         uint32_t h = 0, gh = 0, *ght;
1564         Sym *sym;
1565         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1566                 if (p == RTLD_DEFAULT) {
1567                         p = head;
1568                 } else if (p == RTLD_NEXT) {
1569                         for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1570                         if (!p) p=head;
1571                         p = p->next;
1572                 }
1573                 struct symdef def = find_sym(p, s, 0);
1574                 if (!def.sym) goto failed;
1575                 if ((def.sym->st_info&0xf) == STT_TLS)
1576                         return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1577                 return laddr(def.dso, def.sym->st_value);
1578         }
1579         if (invalid_dso_handle(p))
1580                 return 0;
1581         if ((ght = p->ghashtab)) {
1582                 gh = gnu_hash(s);
1583                 sym = gnu_lookup(gh, ght, p, s);
1584         } else {
1585                 h = sysv_hash(s);
1586                 sym = sysv_lookup(s, h, p);
1587         }
1588         if (sym && (sym->st_info&0xf) == STT_TLS)
1589                 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1590         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1591                 return laddr(p, sym->st_value);
1592         if (p->deps) for (i=0; p->deps[i]; i++) {
1593                 if ((ght = p->deps[i]->ghashtab)) {
1594                         if (!gh) gh = gnu_hash(s);
1595                         sym = gnu_lookup(gh, ght, p->deps[i], s);
1596                 } else {
1597                         if (!h) h = sysv_hash(s);
1598                         sym = sysv_lookup(s, h, p->deps[i]);
1599                 }
1600                 if (sym && (sym->st_info&0xf) == STT_TLS)
1601                         return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1602                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1603                         return laddr(p->deps[i], sym->st_value);
1604         }
1605 failed:
1606         error("Symbol not found: %s", s);
1607         return 0;
1608 }
1609
1610 int __dladdr(const void *addr, Dl_info *info)
1611 {
1612         struct dso *p;
1613         Sym *sym;
1614         uint32_t nsym;
1615         char *strings;
1616         size_t i;
1617         void *best = 0;
1618         char *bestname;
1619
1620         pthread_rwlock_rdlock(&lock);
1621         for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1622         pthread_rwlock_unlock(&lock);
1623
1624         if (!p) return 0;
1625
1626         sym = p->syms;
1627         strings = p->strings;
1628         if (p->hashtab) {
1629                 nsym = p->hashtab[1];
1630         } else {
1631                 uint32_t *buckets;
1632                 uint32_t *hashval;
1633                 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1634                 sym += p->ghashtab[1];
1635                 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1636                         if (buckets[i] > nsym)
1637                                 nsym = buckets[i];
1638                 }
1639                 if (nsym) {
1640                         nsym -= p->ghashtab[1];
1641                         hashval = buckets + p->ghashtab[0] + nsym;
1642                         do nsym++;
1643                         while (!(*hashval++ & 1));
1644                 }
1645         }
1646
1647         for (; nsym; nsym--, sym++) {
1648                 if (sym->st_value
1649                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1650                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1651                         void *symaddr = laddr(p, sym->st_value);
1652                         if (symaddr > addr || symaddr < best)
1653                                 continue;
1654                         best = symaddr;
1655                         bestname = strings + sym->st_name;
1656                         if (addr == symaddr)
1657                                 break;
1658                 }
1659         }
1660
1661         if (!best) return 0;
1662
1663         info->dli_fname = p->name;
1664         info->dli_fbase = p->base;
1665         info->dli_sname = bestname;
1666         info->dli_saddr = best;
1667
1668         return 1;
1669 }
1670
1671 __attribute__((__visibility__("hidden")))
1672 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1673 {
1674         void *res;
1675         pthread_rwlock_rdlock(&lock);
1676         res = do_dlsym(p, s, ra);
1677         pthread_rwlock_unlock(&lock);
1678         return res;
1679 }
1680
1681 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1682 {
1683         struct dso *current;
1684         struct dl_phdr_info info;
1685         int ret = 0;
1686         for(current = head; current;) {
1687                 info.dlpi_addr      = (uintptr_t)current->base;
1688                 info.dlpi_name      = current->name;
1689                 info.dlpi_phdr      = current->phdr;
1690                 info.dlpi_phnum     = current->phnum;
1691                 info.dlpi_adds      = gencnt;
1692                 info.dlpi_subs      = 0;
1693                 info.dlpi_tls_modid = current->tls_id;
1694                 info.dlpi_tls_data  = current->tls_image;
1695
1696                 ret = (callback)(&info, sizeof (info), data);
1697
1698                 if (ret != 0) break;
1699
1700                 pthread_rwlock_rdlock(&lock);
1701                 current = current->next;
1702                 pthread_rwlock_unlock(&lock);
1703         }
1704         return ret;
1705 }
1706 #else
1707 static int invalid_dso_handle(void *h)
1708 {
1709         error("Invalid library handle %p", (void *)h);
1710         return 1;
1711 }
1712 void *dlopen(const char *file, int mode)
1713 {
1714         error("Dynamic loading not supported");
1715         return 0;
1716 }
1717 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1718 {
1719         error("Symbol not found: %s", s);
1720         return 0;
1721 }
1722 int __dladdr (const void *addr, Dl_info *info)
1723 {
1724         return 0;
1725 }
1726 #endif
1727
1728 int __dlinfo(void *dso, int req, void *res)
1729 {
1730         if (invalid_dso_handle(dso)) return -1;
1731         if (req != RTLD_DI_LINKMAP) {
1732                 error("Unsupported request %d", req);
1733                 return -1;
1734         }
1735         *(struct link_map **)res = dso;
1736         return 0;
1737 }
1738
1739 char *dlerror()
1740 {
1741         pthread_t self = __pthread_self();
1742         if (!self->dlerror_flag) return 0;
1743         self->dlerror_flag = 0;
1744         char *s = self->dlerror_buf;
1745         if (s == (void *)-1)
1746                 return "Dynamic linker failed to allocate memory for error message";
1747         else
1748                 return s;
1749 }
1750
1751 int dlclose(void *p)
1752 {
1753         return invalid_dso_handle(p);
1754 }
1755
1756 void __dl_thread_cleanup(void)
1757 {
1758         pthread_t self = __pthread_self();
1759         if (self->dlerror_buf != (void *)-1)
1760                 free(self->dlerror_buf);
1761 }
1762
1763 static void error(const char *fmt, ...)
1764 {
1765         va_list ap;
1766         va_start(ap, fmt);
1767 #ifdef SHARED
1768         if (!runtime) {
1769                 vdprintf(2, fmt, ap);
1770                 dprintf(2, "\n");
1771                 ldso_fail = 1;
1772                 va_end(ap);
1773                 return;
1774         }
1775 #endif
1776         pthread_t self = __pthread_self();
1777         if (self->dlerror_buf != (void *)-1)
1778                 free(self->dlerror_buf);
1779         size_t len = vsnprintf(0, 0, fmt, ap);
1780         va_end(ap);
1781         char *buf = malloc(len+1);
1782         if (buf) {
1783                 va_start(ap, fmt);
1784                 vsnprintf(buf, len+1, fmt, ap);
1785                 va_end(ap);
1786         } else {
1787                 buf = (void *)-1;
1788         }
1789         self->dlerror_buf = buf;
1790         self->dlerror_flag = 1;
1791 }