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 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 126 {
 127         size_t i;
 128         for (i=0; i<cnt; i++) a[i] = 0;
 129         for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
 130                 a[0] |= 1UL<<v[0];
 131                 a[v[0]] = v[1];
 132         }
 133 }
 134
 135 static int search_vec(size_t *v, size_t *r, size_t key)
 136 {
 137         for (; v[0]!=key; v+=2)
 138                 if (!v[0]) return 0;
 139         *r = v[1];
 140         return 1;
 141 }
 142
 143 static uint32_t sysv_hash(const char *s0)
 144 {
 145         const unsigned char *s = (void *)s0;
 146         uint_fast32_t h = 0;
 147         while (*s) {
 148                 h = 16*h + *s++;
 149                 h ^= h>>24 & 0xf0;
 150         }
 151         return h & 0xfffffff;
 152 }
 153
 154 static uint32_t gnu_hash(const char *s0)
 155 {
 156         const unsigned char *s = (void *)s0;
 157         uint_fast32_t h = 5381;
 158         for (; *s; s++)
 159                 h += h*32 + *s;
 160         return h;
 161 }
 162
 163 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 164 {
 165         size_t i;
 166         Sym *syms = dso->syms;
 167         uint32_t *hashtab = dso->hashtab;
 168         char *strings = dso->strings;
 169         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 170                 if ((!dso->versym || dso->versym[i] >= 0)
 171                     && (!strcmp(s, strings+syms[i].st_name)))
 172                         return syms+i;
 173         }
 174         return 0;
 175 }
 176
 177 static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
 178 {
 179         Sym *syms = dso->syms;
 180         char *strings = dso->strings;
 181         uint32_t *hashtab = dso->ghashtab;
 182         uint32_t nbuckets = hashtab[0];
 183         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 184         uint32_t h2;
 185         uint32_t *hashval;
 186         uint32_t i = buckets[h1 % nbuckets];
 187
 188         if (!i) return 0;
 189
 190         hashval = buckets + nbuckets + (i - hashtab[1]);
 191
 192         for (h1 |= 1; ; i++) {
 193                 h2 = *hashval++;
 194                 if ((!dso->versym || dso->versym[i] >= 0)
 195                     && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name))
 196                         return syms+i;
 197                 if (h2 & 1) break;
 198         }
 199
 200         return 0;
 201 }
 202
 203 static Sym *gnu_lookup_filtered(const char *s, uint32_t h1, struct dso *dso, uint32_t fofs, size_t fmask)
 204 {
 205         uint32_t *hashtab = dso->ghashtab;
 206         const size_t *bloomwords = (const void *)(hashtab+4);
 207         size_t f = bloomwords[fofs & (hashtab[2]-1)];
 208         if (!(f & fmask)) return 0;
 209
 210         f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
 211         if (!(f & 1)) return 0;
 212
 213         return gnu_lookup(s, h1, dso);
 214 }
 215
 216 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 217 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 218
 219 #ifndef ARCH_SYM_REJECT_UND
 220 #define ARCH_SYM_REJECT_UND(s) 0
 221 #endif
 222
 223 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 224 {
 225         uint32_t h = 0, gh, gho;
 226         size_t ghm = 0;
 227         struct symdef def = {0};
 228         for (; dso; dso=dso->next) {
 229                 Sym *sym;
 230                 if (!dso->global) continue;
 231                 if (dso->ghashtab) {
 232                         if (!ghm) {
 233                                 gh = gnu_hash(s);
 234                                 int maskbits = 8 * sizeof ghm;
 235                                 gho = gh / maskbits;
 236                                 ghm = 1ul << gh % maskbits;
 237                         }
 238                         sym = gnu_lookup_filtered(s, gh, dso, gho, ghm);
 239                 } else {
 240                         if (!h) h = sysv_hash(s);
 241                         sym = sysv_lookup(s, h, dso);
 242                 }
 243                 if (!sym) continue;
 244                 if (!sym->st_shndx)
 245                         if (need_def || (sym->st_info&0xf) == STT_TLS
 246                             || ARCH_SYM_REJECT_UND(sym))
 247                                 continue;
 248                 if (!sym->st_value)
 249                         if ((sym->st_info&0xf) != STT_TLS)
 250                                 continue;
 251                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 252                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 253
 254                 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
 255                 def.sym = sym;
 256                 def.dso = dso;
 257                 if (sym->st_info>>4 == STB_GLOBAL) break;
 258         }
 259         return def;
 260 }
 261
 262 __attribute__((__visibility__("hidden")))
 263 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
 264
 265 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 266 {
 267         unsigned char *base = dso->base;
 268         Sym *syms = dso->syms;
 269         char *strings = dso->strings;
 270         Sym *sym;
 271         const char *name;
 272         void *ctx;
 273         int type;
 274         int sym_index;
 275         struct symdef def;
 276         size_t *reloc_addr;
 277         size_t sym_val;
 278         size_t tls_val;
 279         size_t addend;
 280         int skip_relative = 0, reuse_addends = 0, save_slot = 0;
 281
 282         if (dso == &ldso) {
 283                 /* Only ldso's REL table needs addend saving/reuse. */
 284                 if (rel == apply_addends_to)
 285                         reuse_addends = 1;
 286                 skip_relative = 1;
 287         }
 288
 289         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 290                 if (skip_relative && IS_RELATIVE(rel[1])) continue;
 291                 type = R_TYPE(rel[1]);
 292                 if (type == REL_NONE) continue;
 293                 sym_index = R_SYM(rel[1]);
 294                 reloc_addr = (void *)(base + rel[0]);
 295                 if (sym_index) {
 296                         sym = syms + sym_index;
 297                         name = strings + sym->st_name;
 298                         ctx = type==REL_COPY ? head->next : head;
 299                         def = find_sym(ctx, name, type==REL_PLT);
 300                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 301                             || sym->st_info>>4 != STB_WEAK)) {
 302                                 error("Error relocating %s: %s: symbol not found",
 303                                         dso->name, name);
 304                                 if (runtime) longjmp(*rtld_fail, 1);
 305                                 continue;
 306                         }
 307                 } else {
 308                         sym = 0;
 309                         def.sym = 0;
 310                         def.dso = dso;
 311                 }
 312
 313                 if (stride > 2) {
 314                         addend = rel[2];
 315                 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
 316                         addend = 0;
 317                 } else if (reuse_addends) {
 318                         /* Save original addend in stage 2 where the dso
 319                          * chain consists of just ldso; otherwise read back
 320                          * saved addend since the inline one was clobbered. */
 321                         if (head==&ldso)
 322                                 saved_addends[save_slot] = *reloc_addr;
 323                         addend = saved_addends[save_slot++];
 324                 } else {
 325                         addend = *reloc_addr;
 326                 }
 327
 328                 sym_val = def.sym ? (size_t)def.dso->base+def.sym->st_value : 0;
 329                 tls_val = def.sym ? def.sym->st_value : 0;
 330
 331                 switch(type) {
 332                 case REL_NONE:
 333                         break;
 334                 case REL_OFFSET:
 335                         addend -= (size_t)reloc_addr;
 336                 case REL_SYMBOLIC:
 337                 case REL_GOT:
 338                 case REL_PLT:
 339                         *reloc_addr = sym_val + addend;
 340                         break;
 341                 case REL_RELATIVE:
 342                         *reloc_addr = (size_t)base + addend;
 343                         break;
 344                 case REL_SYM_OR_REL:
 345                         if (sym) *reloc_addr = sym_val + addend;
 346                         else *reloc_addr = (size_t)base + addend;
 347                         break;
 348                 case REL_COPY:
 349                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 350                         break;
 351                 case REL_OFFSET32:
 352                         *(uint32_t *)reloc_addr = sym_val + addend
 353                                 - (size_t)reloc_addr;
 354                         break;
 355                 case REL_DTPMOD:
 356                         *reloc_addr = def.dso->tls_id;
 357                         break;
 358                 case REL_DTPOFF:
 359                         *reloc_addr = tls_val + addend - DTP_OFFSET;
 360                         break;
 361 #ifdef TLS_ABOVE_TP
 362                 case REL_TPOFF:
 363                         *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend;
 364                         break;
 365 #else
 366                 case REL_TPOFF:
 367                         *reloc_addr = tls_val - def.dso->tls_offset + addend;
 368                         break;
 369                 case REL_TPOFF_NEG:
 370                         *reloc_addr = def.dso->tls_offset - tls_val + addend;
 371                         break;
 372 #endif
 373                 case REL_TLSDESC:
 374                         if (stride<3) addend = reloc_addr[1];
 375                         if (runtime && def.dso->tls_id >= static_tls_cnt) {
 376                                 struct td_index *new = malloc(sizeof *new);
 377                                 if (!new) {
 378                                         error(
 379                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 380                                         dso->name, sym ? name : "(local)" );
 381                                         longjmp(*rtld_fail, 1);
 382                                 }
 383                                 new->next = dso->td_index;
 384                                 dso->td_index = new;
 385                                 new->args[0] = def.dso->tls_id;
 386                                 new->args[1] = tls_val + addend;
 387                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 388                                 reloc_addr[1] = (size_t)new;
 389                         } else {
 390                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 391 #ifdef TLS_ABOVE_TP
 392                                 reloc_addr[1] = tls_val + def.dso->tls_offset
 393                                         + TPOFF_K + addend;
 394 #else
 395                                 reloc_addr[1] = tls_val - def.dso->tls_offset
 396                                         + addend;
 397 #endif
 398                         }
 399                         break;
 400                 default:
 401                         error("Error relocating %s: unsupported relocation type %d",
 402                                 dso->name, type);
 403                         if (runtime) longjmp(*rtld_fail, 1);
 404                         continue;
 405                 }
 406         }
 407 }
 408
 409 /* A huge hack: to make up for the wastefulness of shared libraries
 410  * needing at least a page of dirty memory even if they have no global
 411  * data, we reclaim the gaps at the beginning and end of writable maps
 412  * and "donate" them to the heap by setting up minimal malloc
 413  * structures and then freeing them. */
 414
 415 static void reclaim(struct dso *dso, size_t start, size_t end)
 416 {
 417         size_t *a, *z;
 418         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 419         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 420         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 421         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 422         if (start>end || end-start < 4*sizeof(size_t)) return;
 423         a = (size_t *)(dso->base + start);
 424         z = (size_t *)(dso->base + end);
 425         a[-2] = 1;
 426         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 427         z[1] = 1;
 428         free(a);
 429 }
 430
 431 static void reclaim_gaps(struct dso *dso)
 432 {
 433         Phdr *ph = dso->phdr;
 434         size_t phcnt = dso->phnum;
 435
 436         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 437                 if (ph->p_type!=PT_LOAD) continue;
 438                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 439                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 440                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 441                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 442         }
 443 }
 444
 445 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
 446 {
 447         char *q = mmap(p, n, prot, flags, fd, off);
 448         if (q != MAP_FAILED || errno != EINVAL) return q;
 449         /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
 450         if (flags & MAP_ANONYMOUS) {
 451                 memset(p, 0, n);
 452                 return p;
 453         }
 454         ssize_t r;
 455         if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
 456         for (q=p; n; q+=r, off+=r, n-=r) {
 457                 r = read(fd, q, n);
 458                 if (r < 0 && errno != EINTR) return MAP_FAILED;
 459                 if (!r) {
 460                         memset(q, 0, n);
 461                         break;
 462                 }
 463         }
 464         return p;
 465 }
 466
 467 static void *map_library(int fd, struct dso *dso)
 468 {
 469         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 470         void *allocated_buf=0;
 471         size_t phsize;
 472         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 473         size_t this_min, this_max;
 474         off_t off_start;
 475         Ehdr *eh;
 476         Phdr *ph, *ph0;
 477         unsigned prot;
 478         unsigned char *map=MAP_FAILED, *base;
 479         size_t dyn=0;
 480         size_t tls_image=0;
 481         size_t i;
 482
 483         ssize_t l = read(fd, buf, sizeof buf);
 484         eh = buf;
 485         if (l<0) return 0;
 486         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 487                 goto noexec;
 488         phsize = eh->e_phentsize * eh->e_phnum;
 489         if (phsize > sizeof buf - sizeof *eh) {
 490                 allocated_buf = malloc(phsize);
 491                 if (!allocated_buf) return 0;
 492                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 493                 if (l < 0) goto error;
 494                 if (l != phsize) goto noexec;
 495                 ph = ph0 = allocated_buf;
 496         } else if (eh->e_phoff + phsize > l) {
 497                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 498                 if (l < 0) goto error;
 499                 if (l != phsize) goto noexec;
 500                 ph = ph0 = (void *)(buf + 1);
 501         } else {
 502                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 503         }
 504         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 505                 if (ph->p_type == PT_DYNAMIC) {
 506                         dyn = ph->p_vaddr;
 507                 } else if (ph->p_type == PT_TLS) {
 508                         tls_image = ph->p_vaddr;
 509                         dso->tls_align = ph->p_align;
 510                         dso->tls_len = ph->p_filesz;
 511                         dso->tls_size = ph->p_memsz;
 512                 } else if (ph->p_type == PT_GNU_RELRO) {
 513                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 514                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 515                 }
 516                 if (ph->p_type != PT_LOAD) continue;
 517                 if (ph->p_vaddr < addr_min) {
 518                         addr_min = ph->p_vaddr;
 519                         off_start = ph->p_offset;
 520                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 521                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 522                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 523                 }
 524                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 525                         addr_max = ph->p_vaddr+ph->p_memsz;
 526                 }
 527         }
 528         if (!dyn) goto noexec;
 529         addr_max += PAGE_SIZE-1;
 530         addr_max &= -PAGE_SIZE;
 531         addr_min &= -PAGE_SIZE;
 532         off_start &= -PAGE_SIZE;
 533         map_len = addr_max - addr_min + off_start;
 534         /* The first time, we map too much, possibly even more than
 535          * the length of the file. This is okay because we will not
 536          * use the invalid part; we just need to reserve the right
 537          * amount of virtual address space to map over later. */
 538         map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
 539         if (map==MAP_FAILED) goto error;
 540         /* If the loaded file is not relocatable and the requested address is
 541          * not available, then the load operation must fail. */
 542         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 543                 errno = EBUSY;
 544                 goto error;
 545         }
 546         base = map - addr_min;
 547         dso->phdr = 0;
 548         dso->phnum = 0;
 549         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 550                 if (ph->p_type != PT_LOAD) continue;
 551                 /* Check if the programs headers are in this load segment, and
 552                  * if so, record the address for use by dl_iterate_phdr. */
 553                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 554                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 555                         dso->phdr = (void *)(base + ph->p_vaddr
 556                                 + (eh->e_phoff-ph->p_offset));
 557                         dso->phnum = eh->e_phnum;
 558                         dso->phentsize = eh->e_phentsize;
 559                 }
 560                 /* Reuse the existing mapping for the lowest-address LOAD */
 561                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
 562                 this_min = ph->p_vaddr & -PAGE_SIZE;
 563                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 564                 off_start = ph->p_offset & -PAGE_SIZE;
 565                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 566                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 567                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 568                 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 569                         goto error;
 570                 if (ph->p_memsz > ph->p_filesz) {
 571                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 572                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 573                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 574                         if (pgbrk-(size_t)base < this_max && mmap_fixed((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
 575                                 goto error;
 576                 }
 577         }
 578         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 579                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 580                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
 581                             && errno != ENOSYS)
 582                                 goto error;
 583                         break;
 584                 }
 585         dso->map = map;
 586         dso->map_len = map_len;
 587         dso->base = base;
 588         dso->dynv = (void *)(base+dyn);
 589         if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
 590         if (!runtime) reclaim_gaps(dso);
 591         free(allocated_buf);
 592         return map;
 593 noexec:
 594         errno = ENOEXEC;
 595 error:
 596         if (map!=MAP_FAILED) munmap(map, map_len);
 597         free(allocated_buf);
 598         return 0;
 599 }
 600
 601 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 602 {
 603         size_t l;
 604         int fd;
 605         for (;;) {
 606                 s += strspn(s, ":\n");
 607                 l = strcspn(s, ":\n");
 608                 if (l-1 >= INT_MAX) return -1;
 609                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
 610                         if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 611                         switch (errno) {
 612                         case ENOENT:
 613                         case ENOTDIR:
 614                         case EACCES:
 615                         case ENAMETOOLONG:
 616                                 break;
 617                         default:
 618                                 /* Any negative value but -1 will inhibit
 619                                  * futher path search. */
 620                                 return -2;
 621                         }
 622                 }
 623                 s += l;
 624         }
 625 }
 626
 627 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 628 {
 629         size_t n, l;
 630         const char *s, *t, *origin;
 631         char *d;
 632         if (p->rpath || !p->rpath_orig) return 0;
 633         if (!strchr(p->rpath_orig, '$')) {
 634                 p->rpath = p->rpath_orig;
 635                 return 0;
 636         }
 637         n = 0;
 638         s = p->rpath_orig;
 639         while ((t=strchr(s, '$'))) {
 640                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 641                         return 0;
 642                 s = t+1;
 643                 n++;
 644         }
 645         if (n > SSIZE_MAX/PATH_MAX) return 0;
 646
 647         if (p->kernel_mapped) {
 648                 /* $ORIGIN searches cannot be performed for the main program
 649                  * when it is suid/sgid/AT_SECURE. This is because the
 650                  * pathname is under the control of the caller of execve.
 651                  * For libraries, however, $ORIGIN can be processed safely
 652                  * since the library's pathname came from a trusted source
 653                  * (either system paths or a call to dlopen). */
 654                 if (libc.secure)
 655                         return 0;
 656                 l = readlink("/proc/self/exe", buf, buf_size);
 657                 if (l == -1) switch (errno) {
 658                 case ENOENT:
 659                 case ENOTDIR:
 660                 case EACCES:
 661                         break;
 662                 default:
 663                         return -1;
 664                 }
 665                 if (l >= buf_size)
 666                         return 0;
 667                 buf[l] = 0;
 668                 origin = buf;
 669         } else {
 670                 origin = p->name;
 671         }
 672         t = strrchr(origin, '/');
 673         l = t ? t-origin : 0;
 674         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 675         if (!p->rpath) return -1;
 676
 677         d = p->rpath;
 678         s = p->rpath_orig;
 679         while ((t=strchr(s, '$'))) {
 680                 memcpy(d, s, t-s);
 681                 d += t-s;
 682                 memcpy(d, origin, l);
 683                 d += l;
 684                 /* It was determined previously that the '$' is followed
 685                  * either by "ORIGIN" or "{ORIGIN}". */
 686                 s = t + 7 + 2*(t[1]=='{');
 687         }
 688         strcpy(d, s);
 689         return 0;
 690 }
 691
 692 static void decode_dyn(struct dso *p)
 693 {
 694         size_t dyn[DYN_CNT];
 695         decode_vec(p->dynv, dyn, DYN_CNT);
 696         p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
 697         p->strings = (void *)(p->base + dyn[DT_STRTAB]);
 698         if (dyn[0]&(1<<DT_HASH))
 699                 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
 700         if (dyn[0]&(1<<DT_RPATH))
 701                 p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
 702         if (dyn[0]&(1<<DT_RUNPATH))
 703                 p->rpath_orig = (void *)(p->strings + dyn[DT_RUNPATH]);
 704         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 705                 p->ghashtab = (void *)(p->base + *dyn);
 706         if (search_vec(p->dynv, dyn, DT_VERSYM))
 707                 p->versym = (void *)(p->base + *dyn);
 708 }
 709
 710 static struct dso *load_library(const char *name, struct dso *needed_by)
 711 {
 712         char buf[2*NAME_MAX+2];
 713         const char *pathname;
 714         unsigned char *map;
 715         struct dso *p, temp_dso = {0};
 716         int fd;
 717         struct stat st;
 718         size_t alloc_size;
 719         int n_th = 0;
 720         int is_self = 0;
 721
 722         if (!*name) {
 723                 errno = EINVAL;
 724                 return 0;
 725         }
 726
 727         /* Catch and block attempts to reload the implementation itself */
 728         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 729                 static const char *rp, reserved[] =
 730                         "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
 731                 char *z = strchr(name, '.');
 732                 if (z) {
 733                         size_t l = z-name;
 734                         for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
 735                         if (*rp) {
 736                                 if (ldd_mode) {
 737                                         /* Track which names have been resolved
 738                                          * and only report each one once. */
 739                                         static unsigned reported;
 740                                         unsigned mask = 1U<<(rp-reserved);
 741                                         if (!(reported & mask)) {
 742                                                 reported |= mask;
 743                                                 dprintf(1, "\t%s => %s (%p)\n",
 744                                                         name, ldso.name,
 745                                                         ldso.base);
 746                                         }
 747                                 }
 748                                 is_self = 1;
 749                         }
 750                 }
 751         }
 752         if (!strcmp(name, ldso.name)) is_self = 1;
 753         if (is_self) {
 754                 if (!ldso.prev) {
 755                         tail->next = &ldso;
 756                         ldso.prev = tail;
 757                         tail = ldso.next ? ldso.next : &ldso;
 758                 }
 759                 return &ldso;
 760         }
 761         if (strchr(name, '/')) {
 762                 pathname = name;
 763                 fd = open(name, O_RDONLY|O_CLOEXEC);
 764         } else {
 765                 /* Search for the name to see if it's already loaded */
 766                 for (p=head->next; p; p=p->next) {
 767                         if (p->shortname && !strcmp(p->shortname, name)) {
 768                                 p->refcnt++;
 769                                 return p;
 770                         }
 771                 }
 772                 if (strlen(name) > NAME_MAX) return 0;
 773                 fd = -1;
 774                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 775                 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
 776                         if (fixup_rpath(p, buf, sizeof buf) < 0)
 777                                 fd = -2; /* Inhibit further search. */
 778                         if (p->rpath)
 779                                 fd = path_open(name, p->rpath, buf, sizeof buf);
 780                 }
 781                 if (fd == -1) {
 782                         if (!sys_path) {
 783                                 char *prefix = 0;
 784                                 size_t prefix_len;
 785                                 if (ldso.name[0]=='/') {
 786                                         char *s, *t, *z;
 787                                         for (s=t=z=ldso.name; *s; s++)
 788                                                 if (*s=='/') z=t, t=s;
 789                                         prefix_len = z-ldso.name;
 790                                         if (prefix_len < PATH_MAX)
 791                                                 prefix = ldso.name;
 792                                 }
 793                                 if (!prefix) {
 794                                         prefix = "";
 795                                         prefix_len = 0;
 796                                 }
 797                                 char etc_ldso_path[prefix_len + 1
 798                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
 799                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
 800                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 801                                         (int)prefix_len, prefix);
 802                                 FILE *f = fopen(etc_ldso_path, "rbe");
 803                                 if (f) {
 804                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
 805                                                 free(sys_path);
 806                                                 sys_path = "";
 807                                         }
 808                                         fclose(f);
 809                                 } else if (errno != ENOENT) {
 810                                         sys_path = "";
 811                                 }
 812                         }
 813                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
 814                         fd = path_open(name, sys_path, buf, sizeof buf);
 815                 }
 816                 pathname = buf;
 817         }
 818         if (fd < 0) return 0;
 819         if (fstat(fd, &st) < 0) {
 820                 close(fd);
 821                 return 0;
 822         }
 823         for (p=head->next; p; p=p->next) {
 824                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
 825                         /* If this library was previously loaded with a
 826                          * pathname but a search found the same inode,
 827                          * setup its shortname so it can be found by name. */
 828                         if (!p->shortname && pathname != name)
 829                                 p->shortname = strrchr(p->name, '/')+1;
 830                         close(fd);
 831                         p->refcnt++;
 832                         return p;
 833                 }
 834         }
 835         map = noload ? 0 : map_library(fd, &temp_dso);
 836         close(fd);
 837         if (!map) return 0;
 838
 839         /* Allocate storage for the new DSO. When there is TLS, this
 840          * storage must include a reservation for all pre-existing
 841          * threads to obtain copies of both the new TLS, and an
 842          * extended DTV capable of storing an additional slot for
 843          * the newly-loaded DSO. */
 844         alloc_size = sizeof *p + strlen(pathname) + 1;
 845         if (runtime && temp_dso.tls_image) {
 846                 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
 847                         + sizeof(void *) * (tls_cnt+3);
 848                 n_th = libc.threads_minus_1 + 1;
 849                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
 850                 else alloc_size += n_th * per_th;
 851         }
 852         p = calloc(1, alloc_size);
 853         if (!p) {
 854                 munmap(map, temp_dso.map_len);
 855                 return 0;
 856         }
 857         memcpy(p, &temp_dso, sizeof temp_dso);
 858         decode_dyn(p);
 859         p->dev = st.st_dev;
 860         p->ino = st.st_ino;
 861         p->refcnt = 1;
 862         p->needed_by = needed_by;
 863         p->name = p->buf;
 864         strcpy(p->name, pathname);
 865         /* Add a shortname only if name arg was not an explicit pathname. */
 866         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
 867         if (p->tls_image) {
 868                 p->tls_id = ++tls_cnt;
 869                 tls_align = MAXP2(tls_align, p->tls_align);
 870 #ifdef TLS_ABOVE_TP
 871                 p->tls_offset = tls_offset + ( (tls_align-1) &
 872                         -(tls_offset + (uintptr_t)p->tls_image) );
 873                 tls_offset += p->tls_size;
 874 #else
 875                 tls_offset += p->tls_size + p->tls_align - 1;
 876                 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
 877                         & (p->tls_align-1);
 878                 p->tls_offset = tls_offset;
 879 #endif
 880                 p->new_dtv = (void *)(-sizeof(size_t) &
 881                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
 882                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
 883         }
 884
 885         tail->next = p;
 886         p->prev = tail;
 887         tail = p;
 888
 889         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
 890
 891         return p;
 892 }
 893
 894 static void load_deps(struct dso *p)
 895 {
 896         size_t i, ndeps=0;
 897         struct dso ***deps = &p->deps, **tmp, *dep;
 898         for (; p; p=p->next) {
 899                 for (i=0; p->dynv[i]; i+=2) {
 900                         if (p->dynv[i] != DT_NEEDED) continue;
 901                         dep = load_library(p->strings + p->dynv[i+1], p);
 902                         if (!dep) {
 903                                 error("Error loading shared library %s: %m (needed by %s)",
 904                                         p->strings + p->dynv[i+1], p->name);
 905                                 if (runtime) longjmp(*rtld_fail, 1);
 906                                 continue;
 907                         }
 908                         if (runtime) {
 909                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
 910                                 if (!tmp) longjmp(*rtld_fail, 1);
 911                                 tmp[ndeps++] = dep;
 912                                 tmp[ndeps] = 0;
 913                                 *deps = tmp;
 914                         }
 915                 }
 916         }
 917 }
 918
 919 static void load_preload(char *s)
 920 {
 921         int tmp;
 922         char *z;
 923         for (z=s; *z; s=z) {
 924                 for (   ; *s && (isspace(*s) || *s==':'); s++);
 925                 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
 926                 tmp = *z;
 927                 *z = 0;
 928                 load_library(s, 0);
 929                 *z = tmp;
 930         }
 931 }
 932
 933 static void make_global(struct dso *p)
 934 {
 935         for (; p; p=p->next) p->global = 1;
 936 }
 937
 938 static void do_mips_relocs(struct dso *p, size_t *got)
 939 {
 940         size_t i, j, rel[2];
 941         unsigned char *base = p->base;
 942         i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
 943         if (p==&ldso) {
 944                 got += i;
 945         } else {
 946                 while (i--) *got++ += (size_t)base;
 947         }
 948         j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
 949         i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
 950         Sym *sym = p->syms + j;
 951         rel[0] = (unsigned char *)got - base;
 952         for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
 953                 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
 954                 do_relocs(p, rel, sizeof rel, 2);
 955         }
 956 }
 957
 958 static void reloc_all(struct dso *p)
 959 {
 960         size_t dyn[DYN_CNT];
 961         for (; p; p=p->next) {
 962                 if (p->relocated) continue;
 963                 decode_vec(p->dynv, dyn, DYN_CNT);
 964                 if (NEED_MIPS_GOT_RELOCS)
 965                         do_mips_relocs(p, (void *)(p->base+dyn[DT_PLTGOT]));
 966                 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
 967                         2+(dyn[DT_PLTREL]==DT_RELA));
 968                 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
 969                 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
 970
 971                 if (head != &ldso && p->relro_start != p->relro_end &&
 972                     mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ)
 973                     && errno != ENOSYS) {
 974                         error("Error relocating %s: RELRO protection failed: %m",
 975                                 p->name);
 976                         if (runtime) longjmp(*rtld_fail, 1);
 977                 }
 978
 979                 p->relocated = 1;
 980         }
 981 }
 982
 983 static void kernel_mapped_dso(struct dso *p)
 984 {
 985         size_t min_addr = -1, max_addr = 0, cnt;
 986         Phdr *ph = p->phdr;
 987         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
 988                 if (ph->p_type == PT_DYNAMIC) {
 989                         p->dynv = (void *)(p->base + ph->p_vaddr);
 990                 } else if (ph->p_type == PT_GNU_RELRO) {
 991                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
 992                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 993                 }
 994                 if (ph->p_type != PT_LOAD) continue;
 995                 if (ph->p_vaddr < min_addr)
 996                         min_addr = ph->p_vaddr;
 997                 if (ph->p_vaddr+ph->p_memsz > max_addr)
 998                         max_addr = ph->p_vaddr+ph->p_memsz;
 999         }
1000         min_addr &= -PAGE_SIZE;
1001         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1002         p->map = p->base + min_addr;
1003         p->map_len = max_addr - min_addr;
1004         p->kernel_mapped = 1;
1005 }
1006
1007 static void do_fini()
1008 {
1009         struct dso *p;
1010         size_t dyn[DYN_CNT];
1011         for (p=fini_head; p; p=p->fini_next) {
1012                 if (!p->constructed) continue;
1013                 decode_vec(p->dynv, dyn, DYN_CNT);
1014                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1015                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1016                         size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
1017                         while (n--) ((void (*)(void))*--fn)();
1018                 }
1019 #ifndef NO_LEGACY_INITFINI
1020                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1021                         ((void (*)(void))(p->base + dyn[DT_FINI]))();
1022 #endif
1023         }
1024 }
1025
1026 static void do_init_fini(struct dso *p)
1027 {
1028         size_t dyn[DYN_CNT];
1029         int need_locking = libc.threads_minus_1;
1030         /* Allow recursive calls that arise when a library calls
1031          * dlopen from one of its constructors, but block any
1032          * other threads until all ctors have finished. */
1033         if (need_locking) pthread_mutex_lock(&init_fini_lock);
1034         for (; p; p=p->prev) {
1035                 if (p->constructed) continue;
1036                 p->constructed = 1;
1037                 decode_vec(p->dynv, dyn, DYN_CNT);
1038                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1039                         p->fini_next = fini_head;
1040                         fini_head = p;
1041                 }
1042 #ifndef NO_LEGACY_INITFINI
1043                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1044                         ((void (*)(void))(p->base + dyn[DT_INIT]))();
1045 #endif
1046                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1047                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1048                         size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
1049                         while (n--) ((void (*)(void))*fn++)();
1050                 }
1051                 if (!need_locking && libc.threads_minus_1) {
1052                         need_locking = 1;
1053                         pthread_mutex_lock(&init_fini_lock);
1054                 }
1055         }
1056         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1057 }
1058
1059 static void dl_debug_state(void)
1060 {
1061 }
1062
1063 weak_alias(dl_debug_state, _dl_debug_state);
1064
1065 void __reset_tls()
1066 {
1067         pthread_t self = __pthread_self();
1068         struct dso *p;
1069         for (p=head; p; p=p->next) {
1070                 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
1071                 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
1072                 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
1073                         p->tls_size - p->tls_len);
1074                 if (p->tls_id == (size_t)self->dtv[0]) break;
1075         }
1076 }
1077
1078 void *__copy_tls(unsigned char *mem)
1079 {
1080         pthread_t td;
1081         struct dso *p;
1082         void **dtv;
1083
1084 #ifdef TLS_ABOVE_TP
1085         dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1);
1086
1087         mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1088         td = (pthread_t)mem;
1089         mem += sizeof(struct pthread);
1090
1091         for (p=head; p; p=p->next) {
1092                 if (!p->tls_id) continue;
1093                 dtv[p->tls_id] = mem + p->tls_offset;
1094                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1095         }
1096 #else
1097         dtv = (void **)mem;
1098
1099         mem += libc.tls_size - sizeof(struct pthread);
1100         mem -= (uintptr_t)mem & (tls_align-1);
1101         td = (pthread_t)mem;
1102
1103         for (p=head; p; p=p->next) {
1104                 if (!p->tls_id) continue;
1105                 dtv[p->tls_id] = mem - p->tls_offset;
1106                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1107         }
1108 #endif
1109         dtv[0] = (void *)tls_cnt;
1110         td->dtv = td->dtv_copy = dtv;
1111         return td;
1112 }
1113
1114 __attribute__((__visibility__("hidden")))
1115 void *__tls_get_new(size_t *v)
1116 {
1117         pthread_t self = __pthread_self();
1118
1119         /* Block signals to make accessing new TLS async-signal-safe */
1120         sigset_t set;
1121         __block_all_sigs(&set);
1122         if (v[0]<=(size_t)self->dtv[0]) {
1123                 __restore_sigs(&set);
1124                 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1125         }
1126
1127         /* This is safe without any locks held because, if the caller
1128          * is able to request the Nth entry of the DTV, the DSO list
1129          * must be valid at least that far out and it was synchronized
1130          * at program startup or by an already-completed call to dlopen. */
1131         struct dso *p;
1132         for (p=head; p->tls_id != v[0]; p=p->next);
1133
1134         /* Get new DTV space from new DSO if needed */
1135         if (v[0] > (size_t)self->dtv[0]) {
1136                 void **newdtv = p->new_dtv +
1137                         (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
1138                 memcpy(newdtv, self->dtv,
1139                         ((size_t)self->dtv[0]+1) * sizeof(void *));
1140                 newdtv[0] = (void *)v[0];
1141                 self->dtv = self->dtv_copy = newdtv;
1142         }
1143
1144         /* Get new TLS memory from all new DSOs up to the requested one */
1145         unsigned char *mem;
1146         for (p=head; ; p=p->next) {
1147                 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1148                 mem = p->new_tls + (p->tls_size + p->tls_align)
1149                         * a_fetch_add(&p->new_tls_idx,1);
1150                 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1151                         & (p->tls_align-1);
1152                 self->dtv[p->tls_id] = mem;
1153                 memcpy(mem, p->tls_image, p->tls_len);
1154                 if (p->tls_id == v[0]) break;
1155         }
1156         __restore_sigs(&set);
1157         return mem + v[1] + DTP_OFFSET;
1158 }
1159
1160 static void update_tls_size()
1161 {
1162         libc.tls_size = ALIGN(
1163                 (1+tls_cnt) * sizeof(void *) +
1164                 tls_offset +
1165                 sizeof(struct pthread) +
1166                 tls_align * 2,
1167         tls_align);
1168 }
1169
1170 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1171  * following stage 2 and stage 3 functions via primitive symbolic lookup
1172  * since it does not have access to their addresses to begin with. */
1173
1174 /* Stage 2 of the dynamic linker is called after relative relocations
1175  * have been processed. It can make function calls to static functions
1176  * and access string literals and static data, but cannot use extern
1177  * symbols. Its job is to perform symbolic relocations on the dynamic
1178  * linker itself, but some of the relocations performed may need to be
1179  * replaced later due to copy relocations in the main program. */
1180
1181 void __dls2(unsigned char *base, size_t *sp)
1182 {
1183         Ehdr *ehdr = (void *)base;
1184         ldso.base = base;
1185         ldso.name = ldso.shortname = "libc.so";
1186         ldso.global = 1;
1187         ldso.phnum = ehdr->e_phnum;
1188         ldso.phdr = (void *)(base + ehdr->e_phoff);
1189         ldso.phentsize = ehdr->e_phentsize;
1190         kernel_mapped_dso(&ldso);
1191         decode_dyn(&ldso);
1192
1193         /* Prepare storage for to save clobbered REL addends so they
1194          * can be reused in stage 3. There should be very few. If
1195          * something goes wrong and there are a huge number, abort
1196          * instead of risking stack overflow. */
1197         size_t dyn[DYN_CNT];
1198         decode_vec(ldso.dynv, dyn, DYN_CNT);
1199         size_t *rel = (void *)(base+dyn[DT_REL]);
1200         size_t rel_size = dyn[DT_RELSZ];
1201         size_t symbolic_rel_cnt = 0;
1202         apply_addends_to = rel;
1203         for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1204                 if (!IS_RELATIVE(rel[1])) symbolic_rel_cnt++;
1205         if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1206         size_t addends[symbolic_rel_cnt+1];
1207         saved_addends = addends;
1208
1209         head = &ldso;
1210         reloc_all(&ldso);
1211
1212         ldso.relocated = 0;
1213
1214         /* Call dynamic linker stage-3, __dls3, looking it up
1215          * symbolically as a barrier against moving the address
1216          * load across the above relocation processing. */
1217         struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1218         ((stage3_func)(ldso.base+dls3_def.sym->st_value))(sp);
1219 }
1220
1221 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1222  * fully functional. Its job is to load (if not already loaded) and
1223  * process dependencies and relocations for the main application and
1224  * transfer control to its entry point. */
1225
1226 _Noreturn void __dls3(size_t *sp)
1227 {
1228         static struct dso app, vdso;
1229         size_t aux[AUX_CNT], *auxv;
1230         size_t i;
1231         char *env_preload=0;
1232         size_t vdso_base;
1233         int argc = *sp;
1234         char **argv = (void *)(sp+1);
1235         char **argv_orig = argv;
1236         char **envp = argv+argc+1;
1237
1238         /* Find aux vector just past environ[] and use it to initialize
1239          * global data that may be needed before we can make syscalls. */
1240         __environ = envp;
1241         for (i=argc+1; argv[i]; i++);
1242         libc.auxv = auxv = (void *)(argv+i+1);
1243         decode_vec(auxv, aux, AUX_CNT);
1244         __hwcap = aux[AT_HWCAP];
1245         libc.page_size = aux[AT_PAGESZ];
1246         libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1247                 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1248
1249         /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1250          * use during dynamic linking. If possible it will also serve as the
1251          * thread pointer at runtime. */
1252         libc.tls_size = sizeof builtin_tls;
1253         if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1254                 a_crash();
1255         }
1256
1257         /* Only trust user/env if kernel says we're not suid/sgid */
1258         if (!libc.secure) {
1259                 env_path = getenv("LD_LIBRARY_PATH");
1260                 env_preload = getenv("LD_PRELOAD");
1261         }
1262
1263         /* If the main program was already loaded by the kernel,
1264          * AT_PHDR will point to some location other than the dynamic
1265          * linker's program headers. */
1266         if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1267                 size_t interp_off = 0;
1268                 size_t tls_image = 0;
1269                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1270                 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1271                 app.phnum = aux[AT_PHNUM];
1272                 app.phentsize = aux[AT_PHENT];
1273                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1274                         if (phdr->p_type == PT_PHDR)
1275                                 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1276                         else if (phdr->p_type == PT_INTERP)
1277                                 interp_off = (size_t)phdr->p_vaddr;
1278                         else if (phdr->p_type == PT_TLS) {
1279                                 tls_image = phdr->p_vaddr;
1280                                 app.tls_len = phdr->p_filesz;
1281                                 app.tls_size = phdr->p_memsz;
1282                                 app.tls_align = phdr->p_align;
1283                         }
1284                 }
1285                 if (app.tls_size) app.tls_image = (char *)app.base + tls_image;
1286                 if (interp_off) ldso.name = (char *)app.base + interp_off;
1287                 if ((aux[0] & (1UL<<AT_EXECFN))
1288                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1289                         app.name = (char *)aux[AT_EXECFN];
1290                 else
1291                         app.name = argv[0];
1292                 kernel_mapped_dso(&app);
1293         } else {
1294                 int fd;
1295                 char *ldname = argv[0];
1296                 size_t l = strlen(ldname);
1297                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1298                 argv++;
1299                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1300                         char *opt = argv[0]+2;
1301                         *argv++ = (void *)-1;
1302                         if (!*opt) {
1303                                 break;
1304                         } else if (!memcmp(opt, "list", 5)) {
1305                                 ldd_mode = 1;
1306                         } else if (!memcmp(opt, "library-path", 12)) {
1307                                 if (opt[12]=='=') env_path = opt+13;
1308                                 else if (opt[12]) *argv = 0;
1309                                 else if (*argv) env_path = *argv++;
1310                         } else if (!memcmp(opt, "preload", 7)) {
1311                                 if (opt[7]=='=') env_preload = opt+8;
1312                                 else if (opt[7]) *argv = 0;
1313                                 else if (*argv) env_preload = *argv++;
1314                         } else {
1315                                 argv[0] = 0;
1316                         }
1317                 }
1318                 argv[-1] = (void *)(argc - (argv-argv_orig));
1319                 if (!argv[0]) {
1320                         dprintf(2, "musl libc\n"
1321                                 "Version %s\n"
1322                                 "Dynamic Program Loader\n"
1323                                 "Usage: %s [options] [--] pathname%s\n",
1324                                 __libc_get_version(), ldname,
1325                                 ldd_mode ? "" : " [args]");
1326                         _exit(1);
1327                 }
1328                 fd = open(argv[0], O_RDONLY);
1329                 if (fd < 0) {
1330                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1331                         _exit(1);
1332                 }
1333                 runtime = 1;
1334                 Ehdr *ehdr = (void *)map_library(fd, &app);
1335                 if (!ehdr) {
1336                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1337                         _exit(1);
1338                 }
1339                 runtime = 0;
1340                 close(fd);
1341                 ldso.name = ldname;
1342                 app.name = argv[0];
1343                 aux[AT_ENTRY] = (size_t)app.base + ehdr->e_entry;
1344                 /* Find the name that would have been used for the dynamic
1345                  * linker had ldd not taken its place. */
1346                 if (ldd_mode) {
1347                         for (i=0; i<app.phnum; i++) {
1348                                 if (app.phdr[i].p_type == PT_INTERP)
1349                                         ldso.name = (void *)(app.base
1350                                                 + app.phdr[i].p_vaddr);
1351                         }
1352                         dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1353                 }
1354         }
1355         if (app.tls_size) {
1356                 app.tls_id = tls_cnt = 1;
1357 #ifdef TLS_ABOVE_TP
1358                 app.tls_offset = 0;
1359                 tls_offset = app.tls_size
1360                         + ( -((uintptr_t)app.tls_image + app.tls_size)
1361                         & (app.tls_align-1) );
1362 #else
1363                 tls_offset = app.tls_offset = app.tls_size
1364                         + ( -((uintptr_t)app.tls_image + app.tls_size)
1365                         & (app.tls_align-1) );
1366 #endif
1367                 tls_align = MAXP2(tls_align, app.tls_align);
1368         }
1369         app.global = 1;
1370         decode_dyn(&app);
1371
1372         /* Attach to vdso, if provided by the kernel */
1373         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1374                 Ehdr *ehdr = (void *)vdso_base;
1375                 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1376                 vdso.phnum = ehdr->e_phnum;
1377                 vdso.phentsize = ehdr->e_phentsize;
1378                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1379                         if (phdr->p_type == PT_DYNAMIC)
1380                                 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1381                         if (phdr->p_type == PT_LOAD)
1382                                 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1383                 }
1384                 vdso.name = "";
1385                 vdso.shortname = "linux-gate.so.1";
1386                 vdso.global = 1;
1387                 vdso.relocated = 1;
1388                 decode_dyn(&vdso);
1389                 vdso.prev = &ldso;
1390                 ldso.next = &vdso;
1391         }
1392
1393         /* Initial dso chain consists only of the app. */
1394         head = tail = &app;
1395
1396         /* Donate unused parts of app and library mapping to malloc */
1397         reclaim_gaps(&app);
1398         reclaim_gaps(&ldso);
1399
1400         /* Load preload/needed libraries, add their symbols to the global
1401          * namespace, and perform all remaining relocations. */
1402         if (env_preload) load_preload(env_preload);
1403         load_deps(&app);
1404         make_global(&app);
1405
1406 #ifndef DYNAMIC_IS_RO
1407         for (i=0; app.dynv[i]; i+=2)
1408                 if (app.dynv[i]==DT_DEBUG)
1409                         app.dynv[i+1] = (size_t)&debug;
1410 #endif
1411
1412         /* The main program must be relocated LAST since it may contin
1413          * copy relocations which depend on libraries' relocations. */
1414         reloc_all(app.next);
1415         reloc_all(&app);
1416
1417         update_tls_size();
1418         if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1419                 void *initial_tls = calloc(libc.tls_size, 1);
1420                 if (!initial_tls) {
1421                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1422                                 argv[0], libc.tls_size);
1423                         _exit(127);
1424                 }
1425                 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1426                         a_crash();
1427                 }
1428         } else {
1429                 size_t tmp_tls_size = libc.tls_size;
1430                 pthread_t self = __pthread_self();
1431                 /* Temporarily set the tls size to the full size of
1432                  * builtin_tls so that __copy_tls will use the same layout
1433                  * as it did for before. Then check, just to be safe. */
1434                 libc.tls_size = sizeof builtin_tls;
1435                 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1436                 libc.tls_size = tmp_tls_size;
1437         }
1438         static_tls_cnt = tls_cnt;
1439
1440         if (ldso_fail) _exit(127);
1441         if (ldd_mode) _exit(0);
1442
1443         /* Switch to runtime mode: any further failures in the dynamic
1444          * linker are a reportable failure rather than a fatal startup
1445          * error. */
1446         runtime = 1;
1447
1448         debug.ver = 1;
1449         debug.bp = dl_debug_state;
1450         debug.head = head;
1451         debug.base = ldso.base;
1452         debug.state = 0;
1453         _dl_debug_state();
1454
1455         __init_libc(envp, argv[0]);
1456         atexit(do_fini);
1457         errno = 0;
1458         do_init_fini(tail);
1459
1460         CRTJMP((void *)aux[AT_ENTRY], argv-1);
1461         for(;;);
1462 }
1463
1464 void *dlopen(const char *file, int mode)
1465 {
1466         struct dso *volatile p, *orig_tail, *next;
1467         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1468         size_t i;
1469         int cs;
1470         jmp_buf jb;
1471
1472         if (!file) return head;
1473
1474         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1475         pthread_rwlock_wrlock(&lock);
1476         __inhibit_ptc();
1477
1478         p = 0;
1479         orig_tls_cnt = tls_cnt;
1480         orig_tls_offset = tls_offset;
1481         orig_tls_align = tls_align;
1482         orig_tail = tail;
1483         noload = mode & RTLD_NOLOAD;
1484
1485         rtld_fail = &jb;
1486         if (setjmp(*rtld_fail)) {
1487                 /* Clean up anything new that was (partially) loaded */
1488                 if (p && p->deps) for (i=0; p->deps[i]; i++)
1489                         if (p->deps[i]->global < 0)
1490                                 p->deps[i]->global = 0;
1491                 for (p=orig_tail->next; p; p=next) {
1492                         next = p->next;
1493                         munmap(p->map, p->map_len);
1494                         while (p->td_index) {
1495                                 void *tmp = p->td_index->next;
1496                                 free(p->td_index);
1497                                 p->td_index = tmp;
1498                         }
1499                         if (p->rpath != p->rpath_orig)
1500                                 free(p->rpath);
1501                         free(p->deps);
1502                         free(p);
1503                 }
1504                 tls_cnt = orig_tls_cnt;
1505                 tls_offset = orig_tls_offset;
1506                 tls_align = orig_tls_align;
1507                 tail = orig_tail;
1508                 tail->next = 0;
1509                 p = 0;
1510                 goto end;
1511         } else p = load_library(file, head);
1512
1513         if (!p) {
1514                 error(noload ?
1515                         "Library %s is not already loaded" :
1516                         "Error loading shared library %s: %m",
1517                         file);
1518                 goto end;
1519         }
1520
1521         /* First load handling */
1522         if (!p->deps) {
1523                 load_deps(p);
1524                 if (p->deps) for (i=0; p->deps[i]; i++)
1525                         if (!p->deps[i]->global)
1526                                 p->deps[i]->global = -1;
1527                 if (!p->global) p->global = -1;
1528                 reloc_all(p);
1529                 if (p->deps) for (i=0; p->deps[i]; i++)
1530                         if (p->deps[i]->global < 0)
1531                                 p->deps[i]->global = 0;
1532                 if (p->global < 0) p->global = 0;
1533         }
1534
1535         if (mode & RTLD_GLOBAL) {
1536                 if (p->deps) for (i=0; p->deps[i]; i++)
1537                         p->deps[i]->global = 1;
1538                 p->global = 1;
1539         }
1540
1541         update_tls_size();
1542         _dl_debug_state();
1543         orig_tail = tail;
1544 end:
1545         __release_ptc();
1546         if (p) gencnt++;
1547         pthread_rwlock_unlock(&lock);
1548         if (p) do_init_fini(orig_tail);
1549         pthread_setcancelstate(cs, 0);
1550         return p;
1551 }
1552
1553 static int invalid_dso_handle(void *h)
1554 {
1555         struct dso *p;
1556         for (p=head; p; p=p->next) if (h==p) return 0;
1557         error("Invalid library handle %p", (void *)h);
1558         return 1;
1559 }
1560
1561 void *__tls_get_addr(size_t *);
1562
1563 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1564 {
1565         size_t i;
1566         uint32_t h = 0, gh = 0;
1567         Sym *sym;
1568         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1569                 if (p == RTLD_DEFAULT) {
1570                         p = head;
1571                 } else if (p == RTLD_NEXT) {
1572                         for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1573                         if (!p) p=head;
1574                         p = p->next;
1575                 }
1576                 struct symdef def = find_sym(p, s, 0);
1577                 if (!def.sym) goto failed;
1578                 if ((def.sym->st_info&0xf) == STT_TLS)
1579                         return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1580                 return def.dso->base + def.sym->st_value;
1581         }
1582         if (invalid_dso_handle(p))
1583                 return 0;
1584         if (p->ghashtab) {
1585                 gh = gnu_hash(s);
1586                 sym = gnu_lookup(s, gh, p);
1587         } else {
1588                 h = sysv_hash(s);
1589                 sym = sysv_lookup(s, h, p);
1590         }
1591         if (sym && (sym->st_info&0xf) == STT_TLS)
1592                 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1593         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1594                 return p->base + sym->st_value;
1595         if (p->deps) for (i=0; p->deps[i]; i++) {
1596                 if (p->deps[i]->ghashtab) {
1597                         if (!gh) gh = gnu_hash(s);
1598                         sym = gnu_lookup(s, gh, p->deps[i]);
1599                 } else {
1600                         if (!h) h = sysv_hash(s);
1601                         sym = sysv_lookup(s, h, p->deps[i]);
1602                 }
1603                 if (sym && (sym->st_info&0xf) == STT_TLS)
1604                         return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1605                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1606                         return p->deps[i]->base + sym->st_value;
1607         }
1608 failed:
1609         error("Symbol not found: %s", s);
1610         return 0;
1611 }
1612
1613 int __dladdr(const void *addr, Dl_info *info)
1614 {
1615         struct dso *p;
1616         Sym *sym;
1617         uint32_t nsym;
1618         char *strings;
1619         size_t i;
1620         void *best = 0;
1621         char *bestname;
1622
1623         pthread_rwlock_rdlock(&lock);
1624         for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1625         pthread_rwlock_unlock(&lock);
1626
1627         if (!p) return 0;
1628
1629         sym = p->syms;
1630         strings = p->strings;
1631         if (p->hashtab) {
1632                 nsym = p->hashtab[1];
1633         } else {
1634                 uint32_t *buckets;
1635                 uint32_t *hashval;
1636                 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1637                 sym += p->ghashtab[1];
1638                 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1639                         if (buckets[i] > nsym)
1640                                 nsym = buckets[i];
1641                 }
1642                 if (nsym) {
1643                         nsym -= p->ghashtab[1];
1644                         hashval = buckets + p->ghashtab[0] + nsym;
1645                         do nsym++;
1646                         while (!(*hashval++ & 1));
1647                 }
1648         }
1649
1650         for (; nsym; nsym--, sym++) {
1651                 if (sym->st_value
1652                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1653                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1654                         void *symaddr = p->base + sym->st_value;
1655                         if (symaddr > addr || symaddr < best)
1656                                 continue;
1657                         best = symaddr;
1658                         bestname = strings + sym->st_name;
1659                         if (addr == symaddr)
1660                                 break;
1661                 }
1662         }
1663
1664         if (!best) return 0;
1665
1666         info->dli_fname = p->name;
1667         info->dli_fbase = p->base;
1668         info->dli_sname = bestname;
1669         info->dli_saddr = best;
1670
1671         return 1;
1672 }
1673
1674 __attribute__((__visibility__("hidden")))
1675 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1676 {
1677         void *res;
1678         pthread_rwlock_rdlock(&lock);
1679         res = do_dlsym(p, s, ra);
1680         pthread_rwlock_unlock(&lock);
1681         return res;
1682 }
1683
1684 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1685 {
1686         struct dso *current;
1687         struct dl_phdr_info info;
1688         int ret = 0;
1689         for(current = head; current;) {
1690                 info.dlpi_addr      = (uintptr_t)current->base;
1691                 info.dlpi_name      = current->name;
1692                 info.dlpi_phdr      = current->phdr;
1693                 info.dlpi_phnum     = current->phnum;
1694                 info.dlpi_adds      = gencnt;
1695                 info.dlpi_subs      = 0;
1696                 info.dlpi_tls_modid = current->tls_id;
1697                 info.dlpi_tls_data  = current->tls_image;
1698
1699                 ret = (callback)(&info, sizeof (info), data);
1700
1701                 if (ret != 0) break;
1702
1703                 pthread_rwlock_rdlock(&lock);
1704                 current = current->next;
1705                 pthread_rwlock_unlock(&lock);
1706         }
1707         return ret;
1708 }
1709 #else
1710 static int invalid_dso_handle(void *h)
1711 {
1712         error("Invalid library handle %p", (void *)h);
1713         return 1;
1714 }
1715 void *dlopen(const char *file, int mode)
1716 {
1717         error("Dynamic loading not supported");
1718         return 0;
1719 }
1720 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1721 {
1722         error("Symbol not found: %s", s);
1723         return 0;
1724 }
1725 int __dladdr (const void *addr, Dl_info *info)
1726 {
1727         return 0;
1728 }
1729 #endif
1730
1731 int __dlinfo(void *dso, int req, void *res)
1732 {
1733         if (invalid_dso_handle(dso)) return -1;
1734         if (req != RTLD_DI_LINKMAP) {
1735                 error("Unsupported request %d", req);
1736                 return -1;
1737         }
1738         *(struct link_map **)res = dso;
1739         return 0;
1740 }
1741
1742 char *dlerror()
1743 {
1744         pthread_t self = __pthread_self();
1745         if (!self->dlerror_flag) return 0;
1746         self->dlerror_flag = 0;
1747         char *s = self->dlerror_buf;
1748         if (s == (void *)-1)
1749                 return "Dynamic linker failed to allocate memory for error message";
1750         else
1751                 return s;
1752 }
1753
1754 int dlclose(void *p)
1755 {
1756         return invalid_dso_handle(p);
1757 }
1758
1759 void __dl_thread_cleanup(void)
1760 {
1761         pthread_t self = __pthread_self();
1762         if (self->dlerror_buf != (void *)-1)
1763                 free(self->dlerror_buf);
1764 }
1765
1766 static void error(const char *fmt, ...)
1767 {
1768         va_list ap;
1769         va_start(ap, fmt);
1770 #ifdef SHARED
1771         if (!runtime) {
1772                 vdprintf(2, fmt, ap);
1773                 dprintf(2, "\n");
1774                 ldso_fail = 1;
1775                 va_end(ap);
1776                 return;
1777         }
1778 #endif
1779         pthread_t self = __pthread_self();
1780         if (self->dlerror_buf != (void *)-1)
1781                 free(self->dlerror_buf);
1782         size_t len = vsnprintf(0, 0, fmt, ap);
1783         va_end(ap);
1784         char *buf = malloc(len+1);
1785         if (buf) {
1786                 va_start(ap, fmt);
1787                 vsnprintf(buf, len+1, fmt, ap);
1788                 va_end(ap);
1789         } else {
1790                 buf = (void *)-1;
1791         }
1792         self->dlerror_buf = buf;
1793         self->dlerror_flag = 1;
1794 }