nsz Git - musl/blob - 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
  23 static int errflag;
  24 static char errbuf[128];
  25
  26 #ifdef SHARED
  27
  28 #if ULONG_MAX == 0xffffffff
  29 typedef Elf32_Ehdr Ehdr;
  30 typedef Elf32_Phdr Phdr;
  31 typedef Elf32_Sym Sym;
  32 #define R_TYPE(x) ((x)&255)
  33 #define R_SYM(x) ((x)>>8)
  34 #else
  35 typedef Elf64_Ehdr Ehdr;
  36 typedef Elf64_Phdr Phdr;
  37 typedef Elf64_Sym Sym;
  38 #define R_TYPE(x) ((x)&0xffffffff)
  39 #define R_SYM(x) ((x)>>32)
  40 #endif
  41
  42 #define MAXP2(a,b) (-(-(a)&-(b)))
  43 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  44
  45 struct debug {
  46         int ver;
  47         void *head;
  48         void (*bp)(void);
  49         int state;
  50         void *base;
  51 };
  52
  53 struct td_index {
  54         size_t args[2];
  55         struct td_index *next;
  56 };
  57
  58 struct dso {
  59         unsigned char *base;
  60         char *name;
  61         size_t *dynv;
  62         struct dso *next, *prev;
  63
  64         Phdr *phdr;
  65         int phnum;
  66         size_t phentsize;
  67         int refcnt;
  68         Sym *syms;
  69         uint32_t *hashtab;
  70         uint32_t *ghashtab;
  71         int16_t *versym;
  72         char *strings;
  73         unsigned char *map;
  74         size_t map_len;
  75         dev_t dev;
  76         ino_t ino;
  77         signed char global;
  78         char relocated;
  79         char constructed;
  80         char kernel_mapped;
  81         struct dso **deps, *needed_by;
  82         char *rpath_orig, *rpath;
  83         void *tls_image;
  84         size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
  85         size_t relro_start, relro_end;
  86         void **new_dtv;
  87         unsigned char *new_tls;
  88         int new_dtv_idx, new_tls_idx;
  89         struct td_index *td_index;
  90         struct dso *fini_next;
  91         char *shortname;
  92         char buf[];
  93 };
  94
  95 struct symdef {
  96         Sym *sym;
  97         struct dso *dso;
  98 };
  99
 100 enum {
 101         REL_ERR,
 102         REL_SYMBOLIC,
 103         REL_GOT,
 104         REL_PLT,
 105         REL_RELATIVE,
 106         REL_OFFSET,
 107         REL_OFFSET32,
 108         REL_COPY,
 109         REL_SYM_OR_REL,
 110         REL_TLS, /* everything past here is TLS */
 111         REL_DTPMOD,
 112         REL_DTPOFF,
 113         REL_TPOFF,
 114         REL_TPOFF_NEG,
 115         REL_TLSDESC,
 116 };
 117
 118 #include "reloc.h"
 119
 120 int __init_tp(void *);
 121 void __init_libc(char **, char *);
 122
 123 const char *__libc_get_version(void);
 124
 125 static struct dso *head, *tail, *ldso, *fini_head;
 126 static char *env_path, *sys_path;
 127 static unsigned long long gencnt;
 128 static int runtime;
 129 static int ldd_mode;
 130 static int ldso_fail;
 131 static int noload;
 132 static jmp_buf *rtld_fail;
 133 static pthread_rwlock_t lock;
 134 static struct debug debug;
 135 static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
 136 static size_t static_tls_cnt;
 137 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 138 static long long builtin_tls[(sizeof(struct pthread) + 64)/sizeof(long long)];
 139
 140 struct debug *_dl_debug_addr = &debug;
 141
 142 #define AUX_CNT 38
 143 #define DYN_CNT 34
 144
 145 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 146 {
 147         memset(a, 0, cnt*sizeof(size_t));
 148         for (; v[0]; v+=2) if (v[0]<cnt) {
 149                 a[0] |= 1ULL<<v[0];
 150                 a[v[0]] = v[1];
 151         }
 152 }
 153
 154 static int search_vec(size_t *v, size_t *r, size_t key)
 155 {
 156         for (; v[0]!=key; v+=2)
 157                 if (!v[0]) return 0;
 158         *r = v[1];
 159         return 1;
 160 }
 161
 162 static void error(const char *fmt, ...)
 163 {
 164         va_list ap;
 165         va_start(ap, fmt);
 166         vsnprintf(errbuf, sizeof errbuf, fmt, ap);
 167         va_end(ap);
 168         if (runtime) longjmp(*rtld_fail, 1);
 169         dprintf(2, "%s\n", errbuf);
 170         ldso_fail = 1;
 171 }
 172
 173 static uint32_t sysv_hash(const char *s0)
 174 {
 175         const unsigned char *s = (void *)s0;
 176         uint_fast32_t h = 0;
 177         while (*s) {
 178                 h = 16*h + *s++;
 179                 h ^= h>>24 & 0xf0;
 180         }
 181         return h & 0xfffffff;
 182 }
 183
 184 static uint32_t gnu_hash(const char *s0)
 185 {
 186         const unsigned char *s = (void *)s0;
 187         uint_fast32_t h = 5381;
 188         for (; *s; s++)
 189                 h = h*33 + *s;
 190         return h;
 191 }
 192
 193 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 194 {
 195         size_t i;
 196         Sym *syms = dso->syms;
 197         uint32_t *hashtab = dso->hashtab;
 198         char *strings = dso->strings;
 199         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 200                 if ((!dso->versym || dso->versym[i] >= 0)
 201                     && (!strcmp(s, strings+syms[i].st_name)))
 202                         return syms+i;
 203         }
 204         return 0;
 205 }
 206
 207 static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
 208 {
 209         Sym *syms = dso->syms;
 210         char *strings = dso->strings;
 211         uint32_t *hashtab = dso->ghashtab;
 212         uint32_t nbuckets = hashtab[0];
 213         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 214         uint32_t h2;
 215         uint32_t *hashval;
 216         uint32_t i = buckets[h1 % nbuckets];
 217
 218         if (!i) return 0;
 219
 220         hashval = buckets + nbuckets + (i - hashtab[1]);
 221
 222         for (h1 |= 1; ; i++) {
 223                 h2 = *hashval++;
 224                 if ((!dso->versym || dso->versym[i] >= 0)
 225                     && (h1 == (h2|1)) && !strcmp(s, strings + syms[i].st_name))
 226                         return syms+i;
 227                 if (h2 & 1) break;
 228         }
 229
 230         return 0;
 231 }
 232
 233 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 234 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 235
 236 #ifndef ARCH_SYM_REJECT_UND
 237 #define ARCH_SYM_REJECT_UND(s) 0
 238 #endif
 239
 240 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 241 {
 242         uint32_t h = 0, gh = 0;
 243         struct symdef def = {0};
 244         for (; dso; dso=dso->next) {
 245                 Sym *sym;
 246                 if (!dso->global) continue;
 247                 if (dso->ghashtab) {
 248                         if (!gh) gh = gnu_hash(s);
 249                         sym = gnu_lookup(s, gh, dso);
 250                 } else {
 251                         if (!h) h = sysv_hash(s);
 252                         sym = sysv_lookup(s, h, dso);
 253                 }
 254                 if (!sym) continue;
 255                 if (!sym->st_shndx)
 256                         if (need_def || (sym->st_info&0xf) == STT_TLS
 257                             || ARCH_SYM_REJECT_UND(sym))
 258                                 continue;
 259                 if (!sym->st_value)
 260                         if ((sym->st_info&0xf) != STT_TLS)
 261                                 continue;
 262                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 263                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 264
 265                 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
 266                 def.sym = sym;
 267                 def.dso = dso;
 268                 if (sym->st_info>>4 == STB_GLOBAL) break;
 269         }
 270         return def;
 271 }
 272
 273 #define NO_INLINE_ADDEND (1<<REL_COPY | 1<<REL_GOT | 1<<REL_PLT)
 274
 275 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
 276
 277 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 278 {
 279         unsigned char *base = dso->base;
 280         Sym *syms = dso->syms;
 281         char *strings = dso->strings;
 282         Sym *sym;
 283         const char *name;
 284         void *ctx;
 285         int astype, type;
 286         int sym_index;
 287         struct symdef def;
 288         size_t *reloc_addr;
 289         size_t sym_val;
 290         size_t tls_val;
 291         size_t addend;
 292
 293         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 294                 astype = R_TYPE(rel[1]);
 295                 if (!astype) continue;
 296                 type = remap_rel(astype);
 297                 if (!type) {
 298                         error("Error relocating %s: unsupported relocation type %d",
 299                                 dso->name, astype);
 300                         continue;
 301                 }
 302                 sym_index = R_SYM(rel[1]);
 303                 reloc_addr = (void *)(base + rel[0]);
 304                 if (sym_index) {
 305                         sym = syms + sym_index;
 306                         name = strings + sym->st_name;
 307                         ctx = type==REL_COPY ? head->next : head;
 308                         def = find_sym(ctx, name, type==REL_PLT);
 309                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 310                             || sym->st_info>>4 != STB_WEAK)) {
 311                                 error("Error relocating %s: %s: symbol not found",
 312                                         dso->name, name);
 313                                 continue;
 314                         }
 315                 } else {
 316                         sym = 0;
 317                         def.sym = 0;
 318                         def.dso = dso;
 319                 }
 320
 321                 addend = stride>2 ? rel[2]
 322                         : (1<<type & NO_INLINE_ADDEND) ? 0
 323                         : *reloc_addr;
 324
 325                 sym_val = def.sym ? (size_t)def.dso->base+def.sym->st_value : 0;
 326                 tls_val = def.sym ? def.sym->st_value : 0;
 327
 328                 switch(type) {
 329                 case REL_OFFSET:
 330                         addend -= (size_t)reloc_addr;
 331                 case REL_SYMBOLIC:
 332                 case REL_GOT:
 333                 case REL_PLT:
 334                         *reloc_addr = sym_val + addend;
 335                         break;
 336                 case REL_RELATIVE:
 337                         *reloc_addr = (size_t)base + addend;
 338                         break;
 339                 case REL_SYM_OR_REL:
 340                         if (sym) *reloc_addr = sym_val + addend;
 341                         else *reloc_addr = (size_t)base + addend;
 342                         break;
 343                 case REL_COPY:
 344                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 345                         break;
 346                 case REL_OFFSET32:
 347                         *(uint32_t *)reloc_addr = sym_val + addend
 348                                 - (size_t)reloc_addr;
 349                         break;
 350                 case REL_DTPMOD:
 351                         *reloc_addr = def.dso->tls_id;
 352                         break;
 353                 case REL_DTPOFF:
 354                         *reloc_addr = tls_val + addend;
 355                         break;
 356 #ifdef TLS_ABOVE_TP
 357                 case REL_TPOFF:
 358                         *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend;
 359                         break;
 360 #else
 361                 case REL_TPOFF:
 362                         *reloc_addr = tls_val - def.dso->tls_offset + addend;
 363                         break;
 364                 case REL_TPOFF_NEG:
 365                         *reloc_addr = def.dso->tls_offset - tls_val + addend;
 366                         break;
 367 #endif
 368                 case REL_TLSDESC:
 369                         if (stride<3) addend = reloc_addr[1];
 370                         if (runtime && def.dso->tls_id >= static_tls_cnt) {
 371                                 struct td_index *new = malloc(sizeof *new);
 372                                 if (!new) error(
 373                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 374                                         dso->name, sym ? name : "(local)" );
 375                                 new->next = dso->td_index;
 376                                 dso->td_index = new;
 377                                 new->args[0] = def.dso->tls_id;
 378                                 new->args[1] = tls_val + addend;
 379                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 380                                 reloc_addr[1] = (size_t)new;
 381                         } else {
 382                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 383 #ifdef TLS_ABOVE_TP
 384                                 reloc_addr[1] = tls_val + def.dso->tls_offset
 385                                         + TPOFF_K + addend;
 386 #else
 387                                 reloc_addr[1] = tls_val - def.dso->tls_offset
 388                                         + addend;
 389 #endif
 390                         }
 391                         break;
 392                 }
 393         }
 394 }
 395
 396 /* A huge hack: to make up for the wastefulness of shared libraries
 397  * needing at least a page of dirty memory even if they have no global
 398  * data, we reclaim the gaps at the beginning and end of writable maps
 399  * and "donate" them to the heap by setting up minimal malloc
 400  * structures and then freeing them. */
 401
 402 static void reclaim(struct dso *dso, size_t start, size_t end)
 403 {
 404         size_t *a, *z;
 405         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 406         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 407         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 408         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 409         if (start>end || end-start < 4*sizeof(size_t)) return;
 410         a = (size_t *)(dso->base + start);
 411         z = (size_t *)(dso->base + end);
 412         a[-2] = 1;
 413         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 414         z[1] = 1;
 415         free(a);
 416 }
 417
 418 static void reclaim_gaps(struct dso *dso)
 419 {
 420         Phdr *ph = dso->phdr;
 421         size_t phcnt = dso->phnum;
 422
 423         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 424                 if (ph->p_type!=PT_LOAD) continue;
 425                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 426                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 427                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 428                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 429         }
 430 }
 431
 432 static void *map_library(int fd, struct dso *dso)
 433 {
 434         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 435         void *allocated_buf=0;
 436         size_t phsize;
 437         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 438         size_t this_min, this_max;
 439         off_t off_start;
 440         Ehdr *eh;
 441         Phdr *ph, *ph0;
 442         unsigned prot;
 443         unsigned char *map=MAP_FAILED, *base;
 444         size_t dyn=0;
 445         size_t tls_image=0;
 446         size_t i;
 447
 448         ssize_t l = read(fd, buf, sizeof buf);
 449         eh = buf;
 450         if (l<0) return 0;
 451         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 452                 goto noexec;
 453         phsize = eh->e_phentsize * eh->e_phnum;
 454         if (phsize > sizeof buf - sizeof *eh) {
 455                 allocated_buf = malloc(phsize);
 456                 if (!allocated_buf) return 0;
 457                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 458                 if (l < 0) goto error;
 459                 if (l != phsize) goto noexec;
 460                 ph = ph0 = allocated_buf;
 461         } else if (eh->e_phoff + phsize > l) {
 462                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 463                 if (l < 0) goto error;
 464                 if (l != phsize) goto noexec;
 465                 ph = ph0 = (void *)(buf + 1);
 466         } else {
 467                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 468         }
 469         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 470                 if (ph->p_type == PT_DYNAMIC) {
 471                         dyn = ph->p_vaddr;
 472                 } else if (ph->p_type == PT_TLS) {
 473                         tls_image = ph->p_vaddr;
 474                         dso->tls_align = ph->p_align;
 475                         dso->tls_len = ph->p_filesz;
 476                         dso->tls_size = ph->p_memsz;
 477                 } else if (ph->p_type == PT_GNU_RELRO) {
 478                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 479                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 480                 }
 481                 if (ph->p_type != PT_LOAD) continue;
 482                 if (ph->p_vaddr < addr_min) {
 483                         addr_min = ph->p_vaddr;
 484                         off_start = ph->p_offset;
 485                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 486                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 487                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 488                 }
 489                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 490                         addr_max = ph->p_vaddr+ph->p_memsz;
 491                 }
 492         }
 493         if (!dyn) goto noexec;
 494         addr_max += PAGE_SIZE-1;
 495         addr_max &= -PAGE_SIZE;
 496         addr_min &= -PAGE_SIZE;
 497         off_start &= -PAGE_SIZE;
 498         map_len = addr_max - addr_min + off_start;
 499         /* The first time, we map too much, possibly even more than
 500          * the length of the file. This is okay because we will not
 501          * use the invalid part; we just need to reserve the right
 502          * amount of virtual address space to map over later. */
 503         map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
 504         if (map==MAP_FAILED) goto error;
 505         /* If the loaded file is not relocatable and the requested address is
 506          * not available, then the load operation must fail. */
 507         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 508                 errno = EBUSY;
 509                 goto error;
 510         }
 511         base = map - addr_min;
 512         dso->phdr = 0;
 513         dso->phnum = 0;
 514         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 515                 if (ph->p_type != PT_LOAD) continue;
 516                 /* Check if the programs headers are in this load segment, and
 517                  * if so, record the address for use by dl_iterate_phdr. */
 518                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 519                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 520                         dso->phdr = (void *)(base + ph->p_vaddr
 521                                 + (eh->e_phoff-ph->p_offset));
 522                         dso->phnum = eh->e_phnum;
 523                         dso->phentsize = eh->e_phentsize;
 524                 }
 525                 /* Reuse the existing mapping for the lowest-address LOAD */
 526                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
 527                 this_min = ph->p_vaddr & -PAGE_SIZE;
 528                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 529                 off_start = ph->p_offset & -PAGE_SIZE;
 530                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 531                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 532                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 533                 if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 534                         goto error;
 535                 if (ph->p_memsz > ph->p_filesz) {
 536                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 537                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 538                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 539                         if (pgbrk-(size_t)base < this_max && mmap((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
 540                                 goto error;
 541                 }
 542         }
 543         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 544                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 545                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
 546                                 goto error;
 547                         break;
 548                 }
 549         dso->map = map;
 550         dso->map_len = map_len;
 551         dso->base = base;
 552         dso->dynv = (void *)(base+dyn);
 553         if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
 554         if (!runtime) reclaim_gaps(dso);
 555         free(allocated_buf);
 556         return map;
 557 noexec:
 558         errno = ENOEXEC;
 559 error:
 560         if (map!=MAP_FAILED) munmap(map, map_len);
 561         free(allocated_buf);
 562         return 0;
 563 }
 564
 565 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 566 {
 567         size_t l;
 568         int fd;
 569         for (;;) {
 570                 s += strspn(s, ":\n");
 571                 l = strcspn(s, ":\n");
 572                 if (l-1 >= INT_MAX) return -1;
 573                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) >= buf_size)
 574                         continue;
 575                 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 576                 s += l;
 577         }
 578 }
 579
 580 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 581 {
 582         size_t n, l;
 583         const char *s, *t, *origin;
 584         char *d;
 585         if (p->rpath) return 0;
 586         if (!p->rpath_orig) return -1;
 587         if (!strchr(p->rpath_orig, '$')) {
 588                 p->rpath = p->rpath_orig;
 589                 return 0;
 590         }
 591         n = 0;
 592         s = p->rpath_orig;
 593         while ((t=strchr(s, '$'))) {
 594                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 595                         return -1;
 596                 s = t+1;
 597                 n++;
 598         }
 599         if (n > SSIZE_MAX/PATH_MAX) return -1;
 600
 601         if (p->kernel_mapped) {
 602                 /* $ORIGIN searches cannot be performed for the main program
 603                  * when it is suid/sgid/AT_SECURE. This is because the
 604                  * pathname is under the control of the caller of execve.
 605                  * For libraries, however, $ORIGIN can be processed safely
 606                  * since the library's pathname came from a trusted source
 607                  * (either system paths or a call to dlopen). */
 608                 if (libc.secure)
 609                         return -1;
 610                 l = readlink("/proc/self/exe", buf, buf_size);
 611                 if (l >= buf_size)
 612                         return -1;
 613                 buf[l] = 0;
 614                 origin = buf;
 615         } else {
 616                 origin = p->name;
 617         }
 618         t = strrchr(origin, '/');
 619         l = t ? t-origin : 0;
 620         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 621         if (!p->rpath) return -1;
 622
 623         d = p->rpath;
 624         s = p->rpath_orig;
 625         while ((t=strchr(s, '$'))) {
 626                 memcpy(d, s, t-s);
 627                 d += t-s;
 628                 memcpy(d, origin, l);
 629                 d += l;
 630                 /* It was determined previously that the '$' is followed
 631                  * either by "ORIGIN" or "{ORIGIN}". */
 632                 s = t + 7 + 2*(t[1]=='{');
 633         }
 634         strcpy(d, s);
 635         return 0;
 636 }
 637
 638 static void decode_dyn(struct dso *p)
 639 {
 640         size_t dyn[DYN_CNT] = {0};
 641         decode_vec(p->dynv, dyn, DYN_CNT);
 642         p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
 643         p->strings = (void *)(p->base + dyn[DT_STRTAB]);
 644         if (dyn[0]&(1<<DT_HASH))
 645                 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
 646         if (dyn[0]&(1<<DT_RPATH))
 647                 p->rpath_orig = (void *)(p->strings + dyn[DT_RPATH]);
 648         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 649                 p->ghashtab = (void *)(p->base + *dyn);
 650         if (search_vec(p->dynv, dyn, DT_VERSYM))
 651                 p->versym = (void *)(p->base + *dyn);
 652 }
 653
 654 static struct dso *load_library(const char *name, struct dso *needed_by)
 655 {
 656         char buf[2*NAME_MAX+2];
 657         const char *pathname;
 658         unsigned char *map;
 659         struct dso *p, temp_dso = {0};
 660         int fd;
 661         struct stat st;
 662         size_t alloc_size;
 663         int n_th = 0;
 664         int is_self = 0;
 665
 666         /* Catch and block attempts to reload the implementation itself */
 667         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 668                 static const char *rp, reserved[] =
 669                         "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
 670                 char *z = strchr(name, '.');
 671                 if (z) {
 672                         size_t l = z-name;
 673                         for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
 674                         if (*rp) {
 675                                 if (ldd_mode) {
 676                                         /* Track which names have been resolved
 677                                          * and only report each one once. */
 678                                         static unsigned reported;
 679                                         unsigned mask = 1U<<(rp-reserved);
 680                                         if (!(reported & mask)) {
 681                                                 reported |= mask;
 682                                                 dprintf(1, "\t%s => %s (%p)\n",
 683                                                         name, ldso->name,
 684                                                         ldso->base);
 685                                         }
 686                                 }
 687                                 is_self = 1;
 688                         }
 689                 }
 690         }
 691         if (!strcmp(name, ldso->name)) is_self = 1;
 692         if (is_self) {
 693                 if (!ldso->prev) {
 694                         tail->next = ldso;
 695                         ldso->prev = tail;
 696                         tail = ldso->next ? ldso->next : ldso;
 697                 }
 698                 return ldso;
 699         }
 700         if (strchr(name, '/')) {
 701                 pathname = name;
 702                 fd = open(name, O_RDONLY|O_CLOEXEC);
 703         } else {
 704                 /* Search for the name to see if it's already loaded */
 705                 for (p=head->next; p; p=p->next) {
 706                         if (p->shortname && !strcmp(p->shortname, name)) {
 707                                 p->refcnt++;
 708                                 return p;
 709                         }
 710                 }
 711                 if (strlen(name) > NAME_MAX) return 0;
 712                 fd = -1;
 713                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 714                 for (p=needed_by; fd < 0 && p; p=p->needed_by)
 715                         if (!fixup_rpath(p, buf, sizeof buf))
 716                                 fd = path_open(name, p->rpath, buf, sizeof buf);
 717                 if (fd < 0) {
 718                         if (!sys_path) {
 719                                 char *prefix = 0;
 720                                 size_t prefix_len;
 721                                 if (ldso->name[0]=='/') {
 722                                         char *s, *t, *z;
 723                                         for (s=t=z=ldso->name; *s; s++)
 724                                                 if (*s=='/') z=t, t=s;
 725                                         prefix_len = z-ldso->name;
 726                                         if (prefix_len < PATH_MAX)
 727                                                 prefix = ldso->name;
 728                                 }
 729                                 if (!prefix) {
 730                                         prefix = "";
 731                                         prefix_len = 0;
 732                                 }
 733                                 char etc_ldso_path[prefix_len + 1
 734                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
 735                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
 736                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 737                                         (int)prefix_len, prefix);
 738                                 FILE *f = fopen(etc_ldso_path, "rbe");
 739                                 if (f) {
 740                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
 741                                                 free(sys_path);
 742                                                 sys_path = "";
 743                                         }
 744                                         fclose(f);
 745                                 } else if (errno != ENOENT) {
 746                                         sys_path = "";
 747                                 }
 748                         }
 749                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
 750                         fd = path_open(name, sys_path, buf, sizeof buf);
 751                 }
 752                 pathname = buf;
 753         }
 754         if (fd < 0) return 0;
 755         if (fstat(fd, &st) < 0) {
 756                 close(fd);
 757                 return 0;
 758         }
 759         for (p=head->next; p; p=p->next) {
 760                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
 761                         /* If this library was previously loaded with a
 762                          * pathname but a search found the same inode,
 763                          * setup its shortname so it can be found by name. */
 764                         if (!p->shortname && pathname != name)
 765                                 p->shortname = strrchr(p->name, '/')+1;
 766                         close(fd);
 767                         p->refcnt++;
 768                         return p;
 769                 }
 770         }
 771         map = noload ? 0 : map_library(fd, &temp_dso);
 772         close(fd);
 773         if (!map) return 0;
 774
 775         /* Allocate storage for the new DSO. When there is TLS, this
 776          * storage must include a reservation for all pre-existing
 777          * threads to obtain copies of both the new TLS, and an
 778          * extended DTV capable of storing an additional slot for
 779          * the newly-loaded DSO. */
 780         alloc_size = sizeof *p + strlen(pathname) + 1;
 781         if (runtime && temp_dso.tls_image) {
 782                 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
 783                         + sizeof(void *) * (tls_cnt+3);
 784                 n_th = libc.threads_minus_1 + 1;
 785                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
 786                 else alloc_size += n_th * per_th;
 787         }
 788         p = calloc(1, alloc_size);
 789         if (!p) {
 790                 munmap(map, temp_dso.map_len);
 791                 return 0;
 792         }
 793         memcpy(p, &temp_dso, sizeof temp_dso);
 794         decode_dyn(p);
 795         p->dev = st.st_dev;
 796         p->ino = st.st_ino;
 797         p->refcnt = 1;
 798         p->needed_by = needed_by;
 799         p->name = p->buf;
 800         strcpy(p->name, pathname);
 801         /* Add a shortname only if name arg was not an explicit pathname. */
 802         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
 803         if (p->tls_image) {
 804                 if (runtime && !libc.has_thread_pointer) {
 805                         munmap(map, p->map_len);
 806                         free(p);
 807                         errno = ENOSYS;
 808                         return 0;
 809                 }
 810                 p->tls_id = ++tls_cnt;
 811                 tls_align = MAXP2(tls_align, p->tls_align);
 812 #ifdef TLS_ABOVE_TP
 813                 p->tls_offset = tls_offset + ( (tls_align-1) &
 814                         -(tls_offset + (uintptr_t)p->tls_image) );
 815                 tls_offset += p->tls_size;
 816 #else
 817                 tls_offset += p->tls_size + p->tls_align - 1;
 818                 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
 819                         & (p->tls_align-1);
 820                 p->tls_offset = tls_offset;
 821 #endif
 822                 p->new_dtv = (void *)(-sizeof(size_t) &
 823                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
 824                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
 825         }
 826
 827         tail->next = p;
 828         p->prev = tail;
 829         tail = p;
 830
 831         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
 832
 833         return p;
 834 }
 835
 836 static void load_deps(struct dso *p)
 837 {
 838         size_t i, ndeps=0;
 839         struct dso ***deps = &p->deps, **tmp, *dep;
 840         for (; p; p=p->next) {
 841                 for (i=0; p->dynv[i]; i+=2) {
 842                         if (p->dynv[i] != DT_NEEDED) continue;
 843                         dep = load_library(p->strings + p->dynv[i+1], p);
 844                         if (!dep) {
 845                                 error("Error loading shared library %s: %m (needed by %s)",
 846                                         p->strings + p->dynv[i+1], p->name);
 847                                 continue;
 848                         }
 849                         if (runtime) {
 850                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
 851                                 if (!tmp) longjmp(*rtld_fail, 1);
 852                                 tmp[ndeps++] = dep;
 853                                 tmp[ndeps] = 0;
 854                                 *deps = tmp;
 855                         }
 856                 }
 857         }
 858 }
 859
 860 static void load_preload(char *s)
 861 {
 862         int tmp;
 863         char *z;
 864         for (z=s; *z; s=z) {
 865                 for (   ; *s && (isspace(*s) || *s==':'); s++);
 866                 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
 867                 tmp = *z;
 868                 *z = 0;
 869                 load_library(s, 0);
 870                 *z = tmp;
 871         }
 872 }
 873
 874 static void make_global(struct dso *p)
 875 {
 876         for (; p; p=p->next) p->global = 1;
 877 }
 878
 879 static void reloc_all(struct dso *p)
 880 {
 881         size_t dyn[DYN_CNT] = {0};
 882         for (; p; p=p->next) {
 883                 if (p->relocated) continue;
 884                 decode_vec(p->dynv, dyn, DYN_CNT);
 885 #ifdef NEED_ARCH_RELOCS
 886                 do_arch_relocs(p, head);
 887 #endif
 888                 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
 889                         2+(dyn[DT_PLTREL]==DT_RELA));
 890                 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
 891                 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
 892
 893                 if (p->relro_start != p->relro_end &&
 894                     mprotect(p->base+p->relro_start, p->relro_end-p->relro_start, PROT_READ) < 0) {
 895                         error("Error relocating %s: RELRO protection failed: %m",
 896                                 p->name);
 897                 }
 898
 899                 p->relocated = 1;
 900         }
 901 }
 902
 903 static void kernel_mapped_dso(struct dso *p)
 904 {
 905         size_t min_addr = -1, max_addr = 0, cnt;
 906         Phdr *ph = p->phdr;
 907         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
 908                 if (ph->p_type == PT_DYNAMIC) {
 909                         p->dynv = (void *)(p->base + ph->p_vaddr);
 910                 } else if (ph->p_type == PT_GNU_RELRO) {
 911                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
 912                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 913                 }
 914                 if (ph->p_type != PT_LOAD) continue;
 915                 if (ph->p_vaddr < min_addr)
 916                         min_addr = ph->p_vaddr;
 917                 if (ph->p_vaddr+ph->p_memsz > max_addr)
 918                         max_addr = ph->p_vaddr+ph->p_memsz;
 919         }
 920         min_addr &= -PAGE_SIZE;
 921         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
 922         p->map = p->base + min_addr;
 923         p->map_len = max_addr - min_addr;
 924         p->kernel_mapped = 1;
 925 }
 926
 927 static void do_fini()
 928 {
 929         struct dso *p;
 930         size_t dyn[DYN_CNT] = {0};
 931         for (p=fini_head; p; p=p->fini_next) {
 932                 if (!p->constructed) continue;
 933                 decode_vec(p->dynv, dyn, DYN_CNT);
 934                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
 935                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
 936                         size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
 937                         while (n--) ((void (*)(void))*--fn)();
 938                 }
 939 #ifndef NO_LEGACY_INITFINI
 940                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
 941                         ((void (*)(void))(p->base + dyn[DT_FINI]))();
 942 #endif
 943         }
 944 }
 945
 946 static void do_init_fini(struct dso *p)
 947 {
 948         size_t dyn[DYN_CNT] = {0};
 949         int need_locking = libc.threads_minus_1;
 950         /* Allow recursive calls that arise when a library calls
 951          * dlopen from one of its constructors, but block any
 952          * other threads until all ctors have finished. */
 953         if (need_locking) pthread_mutex_lock(&init_fini_lock);
 954         for (; p; p=p->prev) {
 955                 if (p->constructed) continue;
 956                 p->constructed = 1;
 957                 decode_vec(p->dynv, dyn, DYN_CNT);
 958                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
 959                         p->fini_next = fini_head;
 960                         fini_head = p;
 961                 }
 962 #ifndef NO_LEGACY_INITFINI
 963                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
 964                         ((void (*)(void))(p->base + dyn[DT_INIT]))();
 965 #endif
 966                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
 967                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
 968                         size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
 969                         while (n--) ((void (*)(void))*fn++)();
 970                 }
 971                 if (!need_locking && libc.threads_minus_1) {
 972                         need_locking = 1;
 973                         pthread_mutex_lock(&init_fini_lock);
 974                 }
 975         }
 976         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
 977 }
 978
 979 void _dl_debug_state(void)
 980 {
 981 }
 982
 983 void __reset_tls()
 984 {
 985         pthread_t self = __pthread_self();
 986         struct dso *p;
 987         for (p=head; p; p=p->next) {
 988                 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
 989                 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
 990                 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
 991                         p->tls_size - p->tls_len);
 992                 if (p->tls_id == (size_t)self->dtv[0]) break;
 993         }
 994 }
 995
 996 void *__copy_tls(unsigned char *mem)
 997 {
 998         pthread_t td;
 999         struct dso *p;
1000
1001         void **dtv = (void *)mem;
1002         dtv[0] = (void *)tls_cnt;
1003         if (!tls_cnt) {
1004                 td = (void *)(dtv+1);
1005                 td->dtv = dtv;
1006                 return td;
1007         }
1008
1009 #ifdef TLS_ABOVE_TP
1010         mem += sizeof(void *) * (tls_cnt+1);
1011         mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1012         td = (pthread_t)mem;
1013         mem += sizeof(struct pthread);
1014
1015         for (p=head; p; p=p->next) {
1016                 if (!p->tls_id) continue;
1017                 dtv[p->tls_id] = mem + p->tls_offset;
1018                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1019         }
1020 #else
1021         mem += libc.tls_size - sizeof(struct pthread);
1022         mem -= (uintptr_t)mem & (tls_align-1);
1023         td = (pthread_t)mem;
1024
1025         for (p=head; p; p=p->next) {
1026                 if (!p->tls_id) continue;
1027                 dtv[p->tls_id] = mem - p->tls_offset;
1028                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1029         }
1030 #endif
1031         td->dtv = dtv;
1032         return td;
1033 }
1034
1035 void *__tls_get_new(size_t *v)
1036 {
1037         pthread_t self = __pthread_self();
1038
1039         /* Block signals to make accessing new TLS async-signal-safe */
1040         sigset_t set;
1041         __block_all_sigs(&set);
1042         if (v[0]<=(size_t)self->dtv[0]) {
1043                 __restore_sigs(&set);
1044                 return (char *)self->dtv[v[0]]+v[1];
1045         }
1046
1047         /* This is safe without any locks held because, if the caller
1048          * is able to request the Nth entry of the DTV, the DSO list
1049          * must be valid at least that far out and it was synchronized
1050          * at program startup or by an already-completed call to dlopen. */
1051         struct dso *p;
1052         for (p=head; p->tls_id != v[0]; p=p->next);
1053
1054         /* Get new DTV space from new DSO if needed */
1055         if (v[0] > (size_t)self->dtv[0]) {
1056                 void **newdtv = p->new_dtv +
1057                         (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
1058                 memcpy(newdtv, self->dtv,
1059                         ((size_t)self->dtv[0]+1) * sizeof(void *));
1060                 newdtv[0] = (void *)v[0];
1061                 self->dtv = newdtv;
1062         }
1063
1064         /* Get new TLS memory from all new DSOs up to the requested one */
1065         unsigned char *mem;
1066         for (p=head; ; p=p->next) {
1067                 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1068                 mem = p->new_tls + (p->tls_size + p->tls_align)
1069                         * a_fetch_add(&p->new_tls_idx,1);
1070                 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1071                         & (p->tls_align-1);
1072                 self->dtv[p->tls_id] = mem;
1073                 memcpy(mem, p->tls_image, p->tls_len);
1074                 if (p->tls_id == v[0]) break;
1075         }
1076         __restore_sigs(&set);
1077         return mem + v[1];
1078 }
1079
1080 static void update_tls_size()
1081 {
1082         libc.tls_size = ALIGN(
1083                 (1+tls_cnt) * sizeof(void *) +
1084                 tls_offset +
1085                 sizeof(struct pthread) +
1086                 tls_align * 2,
1087         tls_align);
1088 }
1089
1090 void *__dynlink(int argc, char **argv)
1091 {
1092         size_t aux[AUX_CNT] = {0};
1093         size_t i;
1094         Phdr *phdr;
1095         Ehdr *ehdr;
1096         static struct dso builtin_dsos[3];
1097         struct dso *const app = builtin_dsos+0;
1098         struct dso *const lib = builtin_dsos+1;
1099         struct dso *const vdso = builtin_dsos+2;
1100         char *env_preload=0;
1101         size_t vdso_base;
1102         size_t *auxv;
1103         char **envp = argv+argc+1;
1104         void *initial_tls;
1105
1106         /* Find aux vector just past environ[] */
1107         for (i=argc+1; argv[i]; i++)
1108                 if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
1109                         env_path = argv[i]+16;
1110                 else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
1111                         env_preload = argv[i]+11;
1112         auxv = (void *)(argv+i+1);
1113
1114         decode_vec(auxv, aux, AUX_CNT);
1115
1116         /* Only trust user/env if kernel says we're not suid/sgid */
1117         if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1118           || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
1119                 env_path = 0;
1120                 env_preload = 0;
1121                 libc.secure = 1;
1122         }
1123         libc.page_size = aux[AT_PAGESZ];
1124
1125         /* If the dynamic linker was invoked as a program itself, AT_BASE
1126          * will not be set. In that case, we assume the base address is
1127          * the start of the page containing the PHDRs; I don't know any
1128          * better approach... */
1129         if (!aux[AT_BASE]) {
1130                 aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE;
1131                 aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0;
1132         }
1133
1134         /* The dynamic linker load address is passed by the kernel
1135          * in the AUX vector, so this is easy. */
1136         lib->base = (void *)aux[AT_BASE];
1137         lib->name = lib->shortname = "libc.so";
1138         lib->global = 1;
1139         ehdr = (void *)lib->base;
1140         lib->phnum = ehdr->e_phnum;
1141         lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff);
1142         lib->phentsize = ehdr->e_phentsize;
1143         kernel_mapped_dso(lib);
1144         decode_dyn(lib);
1145
1146         if (aux[AT_PHDR]) {
1147                 size_t interp_off = 0;
1148                 size_t tls_image = 0;
1149                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1150                 app->phdr = phdr = (void *)aux[AT_PHDR];
1151                 app->phnum = aux[AT_PHNUM];
1152                 app->phentsize = aux[AT_PHENT];
1153                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1154                         if (phdr->p_type == PT_PHDR)
1155                                 app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1156                         else if (phdr->p_type == PT_INTERP)
1157                                 interp_off = (size_t)phdr->p_vaddr;
1158                         else if (phdr->p_type == PT_TLS) {
1159                                 tls_image = phdr->p_vaddr;
1160                                 app->tls_len = phdr->p_filesz;
1161                                 app->tls_size = phdr->p_memsz;
1162                                 app->tls_align = phdr->p_align;
1163                         }
1164                 }
1165                 if (app->tls_size) app->tls_image = (char *)app->base + tls_image;
1166                 if (interp_off) lib->name = (char *)app->base + interp_off;
1167                 if ((aux[0] & (1UL<<AT_EXECFN))
1168                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1169                         app->name = (char *)aux[AT_EXECFN];
1170                 else
1171                         app->name = argv[0];
1172                 kernel_mapped_dso(app);
1173         } else {
1174                 int fd;
1175                 char *ldname = argv[0];
1176                 size_t l = strlen(ldname);
1177                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1178                 *argv++ = (void *)-1;
1179                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1180                         char *opt = argv[0]+2;
1181                         *argv++ = (void *)-1;
1182                         if (!*opt) {
1183                                 break;
1184                         } else if (!memcmp(opt, "list", 5)) {
1185                                 ldd_mode = 1;
1186                         } else if (!memcmp(opt, "library-path", 12)) {
1187                                 if (opt[12]=='=') env_path = opt+13;
1188                                 else if (opt[12]) *argv = 0;
1189                                 else if (*argv) env_path = *argv++;
1190                         } else if (!memcmp(opt, "preload", 7)) {
1191                                 if (opt[7]=='=') env_preload = opt+8;
1192                                 else if (opt[7]) *argv = 0;
1193                                 else if (*argv) env_preload = *argv++;
1194                         } else {
1195                                 argv[0] = 0;
1196                         }
1197                         argv[-1] = (void *)-1;
1198                 }
1199                 if (!argv[0]) {
1200                         dprintf(2, "musl libc\n"
1201                                 "Version %s\n"
1202                                 "Dynamic Program Loader\n"
1203                                 "Usage: %s [options] [--] pathname%s\n",
1204                                 __libc_get_version(), ldname,
1205                                 ldd_mode ? "" : " [args]");
1206                         _exit(1);
1207                 }
1208                 fd = open(argv[0], O_RDONLY);
1209                 if (fd < 0) {
1210                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1211                         _exit(1);
1212                 }
1213                 runtime = 1;
1214                 ehdr = (void *)map_library(fd, app);
1215                 if (!ehdr) {
1216                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1217                         _exit(1);
1218                 }
1219                 runtime = 0;
1220                 close(fd);
1221                 lib->name = ldname;
1222                 app->name = argv[0];
1223                 aux[AT_ENTRY] = (size_t)app->base + ehdr->e_entry;
1224                 /* Find the name that would have been used for the dynamic
1225                  * linker had ldd not taken its place. */
1226                 if (ldd_mode) {
1227                         for (i=0; i<app->phnum; i++) {
1228                                 if (app->phdr[i].p_type == PT_INTERP)
1229                                         lib->name = (void *)(app->base
1230                                                 + app->phdr[i].p_vaddr);
1231                         }
1232                         dprintf(1, "\t%s (%p)\n", lib->name, lib->base);
1233                 }
1234         }
1235         if (app->tls_size) {
1236                 app->tls_id = tls_cnt = 1;
1237 #ifdef TLS_ABOVE_TP
1238                 app->tls_offset = 0;
1239                 tls_offset = app->tls_size
1240                         + ( -((uintptr_t)app->tls_image + app->tls_size)
1241                         & (app->tls_align-1) );
1242 #else
1243                 tls_offset = app->tls_offset = app->tls_size
1244                         + ( -((uintptr_t)app->tls_image + app->tls_size)
1245                         & (app->tls_align-1) );
1246 #endif
1247                 tls_align = MAXP2(tls_align, app->tls_align);
1248         }
1249         app->global = 1;
1250         decode_dyn(app);
1251
1252         /* Attach to vdso, if provided by the kernel */
1253         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1254                 ehdr = (void *)vdso_base;
1255                 vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff);
1256                 vdso->phnum = ehdr->e_phnum;
1257                 vdso->phentsize = ehdr->e_phentsize;
1258                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1259                         if (phdr->p_type == PT_DYNAMIC)
1260                                 vdso->dynv = (void *)(vdso_base + phdr->p_offset);
1261                         if (phdr->p_type == PT_LOAD)
1262                                 vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1263                 }
1264                 vdso->name = "";
1265                 vdso->shortname = "linux-gate.so.1";
1266                 vdso->global = 1;
1267                 decode_dyn(vdso);
1268                 vdso->prev = lib;
1269                 lib->next = vdso;
1270         }
1271
1272         /* Initial dso chain consists only of the app. We temporarily
1273          * append the dynamic linker/libc so we can relocate it, then
1274          * restore the initial chain in preparation for loading third
1275          * party libraries (preload/needed). */
1276         head = tail = app;
1277         ldso = lib;
1278         app->next = lib;
1279         reloc_all(lib);
1280         app->next = 0;
1281
1282         /* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */
1283
1284         /* Donate unused parts of app and library mapping to malloc */
1285         reclaim_gaps(app);
1286         reclaim_gaps(lib);
1287
1288         /* Load preload/needed libraries, add their symbols to the global
1289          * namespace, and perform all remaining relocations. The main
1290          * program must be relocated LAST since it may contain copy
1291          * relocations which depend on libraries' relocations. */
1292         if (env_preload) load_preload(env_preload);
1293         load_deps(app);
1294         make_global(app);
1295
1296 #ifndef DYNAMIC_IS_RO
1297         for (i=0; app->dynv[i]; i+=2)
1298                 if (app->dynv[i]==DT_DEBUG)
1299                         app->dynv[i+1] = (size_t)&debug;
1300 #endif
1301
1302         reloc_all(app->next);
1303         reloc_all(app);
1304
1305         update_tls_size();
1306         if (libc.tls_size > sizeof builtin_tls) {
1307                 initial_tls = calloc(libc.tls_size, 1);
1308                 if (!initial_tls) {
1309                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1310                                 argv[0], libc.tls_size);
1311                         _exit(127);
1312                 }
1313         } else {
1314                 initial_tls = builtin_tls;
1315         }
1316         if (__init_tp(__copy_tls(initial_tls)) < 0 && tls_cnt) {
1317                 dprintf(2, "%s: Thread-local storage not supported by kernel.\n", argv[0]);
1318                 _exit(127);
1319         }
1320         static_tls_cnt = tls_cnt;
1321
1322         if (ldso_fail) _exit(127);
1323         if (ldd_mode) _exit(0);
1324
1325         /* Switch to runtime mode: any further failures in the dynamic
1326          * linker are a reportable failure rather than a fatal startup
1327          * error. If the dynamic loader (dlopen) will not be used, free
1328          * all memory used by the dynamic linker. */
1329         runtime = 1;
1330
1331         debug.ver = 1;
1332         debug.bp = _dl_debug_state;
1333         debug.head = head;
1334         debug.base = lib->base;
1335         debug.state = 0;
1336         _dl_debug_state();
1337
1338         __init_libc(envp, argv[0]);
1339         atexit(do_fini);
1340         errno = 0;
1341         do_init_fini(tail);
1342
1343         return (void *)aux[AT_ENTRY];
1344 }
1345
1346 void *dlopen(const char *file, int mode)
1347 {
1348         struct dso *volatile p, *orig_tail, *next;
1349         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1350         size_t i;
1351         int cs;
1352         jmp_buf jb;
1353
1354         if (!file) return head;
1355
1356         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1357         pthread_rwlock_wrlock(&lock);
1358         __inhibit_ptc();
1359
1360         p = 0;
1361         orig_tls_cnt = tls_cnt;
1362         orig_tls_offset = tls_offset;
1363         orig_tls_align = tls_align;
1364         orig_tail = tail;
1365         noload = mode & RTLD_NOLOAD;
1366
1367         rtld_fail = &jb;
1368         if (setjmp(*rtld_fail)) {
1369                 /* Clean up anything new that was (partially) loaded */
1370                 if (p && p->deps) for (i=0; p->deps[i]; i++)
1371                         if (p->deps[i]->global < 0)
1372                                 p->deps[i]->global = 0;
1373                 for (p=orig_tail->next; p; p=next) {
1374                         next = p->next;
1375                         munmap(p->map, p->map_len);
1376                         while (p->td_index) {
1377                                 void *tmp = p->td_index->next;
1378                                 free(p->td_index);
1379                                 p->td_index = tmp;
1380                         }
1381                         free(p->deps);
1382                         free(p);
1383                 }
1384                 tls_cnt = orig_tls_cnt;
1385                 tls_offset = orig_tls_offset;
1386                 tls_align = orig_tls_align;
1387                 tail = orig_tail;
1388                 tail->next = 0;
1389                 p = 0;
1390                 errflag = 1;
1391                 goto end;
1392         } else p = load_library(file, head);
1393
1394         if (!p) {
1395                 snprintf(errbuf, sizeof errbuf, noload ?
1396                         "Library %s is not already loaded" :
1397                         "Error loading shared library %s: %m",
1398                         file);
1399                 errflag = 1;
1400                 goto end;
1401         }
1402
1403         /* First load handling */
1404         if (!p->deps) {
1405                 load_deps(p);
1406                 if (p->deps) for (i=0; p->deps[i]; i++)
1407                         if (!p->deps[i]->global)
1408                                 p->deps[i]->global = -1;
1409                 if (!p->global) p->global = -1;
1410                 reloc_all(p);
1411                 if (p->deps) for (i=0; p->deps[i]; i++)
1412                         if (p->deps[i]->global < 0)
1413                                 p->deps[i]->global = 0;
1414                 if (p->global < 0) p->global = 0;
1415         }
1416
1417         if (mode & RTLD_GLOBAL) {
1418                 if (p->deps) for (i=0; p->deps[i]; i++)
1419                         p->deps[i]->global = 1;
1420                 p->global = 1;
1421         }
1422
1423         update_tls_size();
1424         _dl_debug_state();
1425         orig_tail = tail;
1426 end:
1427         __release_ptc();
1428         if (p) gencnt++;
1429         pthread_rwlock_unlock(&lock);
1430         if (p) do_init_fini(orig_tail);
1431         pthread_setcancelstate(cs, 0);
1432         return p;
1433 }
1434
1435 static int invalid_dso_handle(void *h)
1436 {
1437         struct dso *p;
1438         for (p=head; p; p=p->next) if (h==p) return 0;
1439         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1440         errflag = 1;
1441         return 1;
1442 }
1443
1444 void *__tls_get_addr(size_t *);
1445
1446 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1447 {
1448         size_t i;
1449         uint32_t h = 0, gh = 0;
1450         Sym *sym;
1451         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1452                 if (p == RTLD_DEFAULT) {
1453                         p = head;
1454                 } else if (p == RTLD_NEXT) {
1455                         for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1456                         if (!p) p=head;
1457                         p = p->next;
1458                 }
1459                 struct symdef def = find_sym(p, s, 0);
1460                 if (!def.sym) goto failed;
1461                 if ((def.sym->st_info&0xf) == STT_TLS)
1462                         return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1463                 return def.dso->base + def.sym->st_value;
1464         }
1465         if (p != RTLD_DEFAULT && p != RTLD_NEXT && invalid_dso_handle(p))
1466                 return 0;
1467         if (p->ghashtab) {
1468                 gh = gnu_hash(s);
1469                 sym = gnu_lookup(s, gh, p);
1470         } else {
1471                 h = sysv_hash(s);
1472                 sym = sysv_lookup(s, h, p);
1473         }
1474         if (sym && (sym->st_info&0xf) == STT_TLS)
1475                 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1476         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1477                 return p->base + sym->st_value;
1478         if (p->deps) for (i=0; p->deps[i]; i++) {
1479                 if (p->deps[i]->ghashtab) {
1480                         if (!gh) gh = gnu_hash(s);
1481                         sym = gnu_lookup(s, gh, p->deps[i]);
1482                 } else {
1483                         if (!h) h = sysv_hash(s);
1484                         sym = sysv_lookup(s, h, p->deps[i]);
1485                 }
1486                 if (sym && (sym->st_info&0xf) == STT_TLS)
1487                         return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1488                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1489                         return p->deps[i]->base + sym->st_value;
1490         }
1491 failed:
1492         errflag = 1;
1493         snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
1494         return 0;
1495 }
1496
1497 int __dladdr(const void *addr, Dl_info *info)
1498 {
1499         struct dso *p;
1500         Sym *sym;
1501         uint32_t nsym;
1502         char *strings;
1503         size_t i;
1504         void *best = 0;
1505         char *bestname;
1506
1507         pthread_rwlock_rdlock(&lock);
1508         for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1509         pthread_rwlock_unlock(&lock);
1510
1511         if (!p) return 0;
1512
1513         sym = p->syms;
1514         strings = p->strings;
1515         if (p->hashtab) {
1516                 nsym = p->hashtab[1];
1517         } else {
1518                 uint32_t *buckets;
1519                 uint32_t *hashval;
1520                 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1521                 sym += p->ghashtab[1];
1522                 for (i = nsym = 0; i < p->ghashtab[0]; i++) {
1523                         if (buckets[i] > nsym)
1524                                 nsym = buckets[i];
1525                 }
1526                 if (nsym) {
1527                         nsym -= p->ghashtab[1];
1528                         hashval = buckets + p->ghashtab[0] + nsym;
1529                         do nsym++;
1530                         while (!(*hashval++ & 1));
1531                 }
1532         }
1533
1534         for (; nsym; nsym--, sym++) {
1535                 if (sym->st_value
1536                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1537                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1538                         void *symaddr = p->base + sym->st_value;
1539                         if (symaddr > addr || symaddr < best)
1540                                 continue;
1541                         best = symaddr;
1542                         bestname = strings + sym->st_name;
1543                         if (addr == symaddr)
1544                                 break;
1545                 }
1546         }
1547
1548         if (!best) return 0;
1549
1550         info->dli_fname = p->name;
1551         info->dli_fbase = p->base;
1552         info->dli_sname = bestname;
1553         info->dli_saddr = best;
1554
1555         return 1;
1556 }
1557
1558 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1559 {
1560         void *res;
1561         pthread_rwlock_rdlock(&lock);
1562         res = do_dlsym(p, s, ra);
1563         pthread_rwlock_unlock(&lock);
1564         return res;
1565 }
1566
1567 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1568 {
1569         struct dso *current;
1570         struct dl_phdr_info info;
1571         int ret = 0;
1572         for(current = head; current;) {
1573                 info.dlpi_addr      = (uintptr_t)current->base;
1574                 info.dlpi_name      = current->name;
1575                 info.dlpi_phdr      = current->phdr;
1576                 info.dlpi_phnum     = current->phnum;
1577                 info.dlpi_adds      = gencnt;
1578                 info.dlpi_subs      = 0;
1579                 info.dlpi_tls_modid = current->tls_id;
1580                 info.dlpi_tls_data  = current->tls_image;
1581
1582                 ret = (callback)(&info, sizeof (info), data);
1583
1584                 if (ret != 0) break;
1585
1586                 pthread_rwlock_rdlock(&lock);
1587                 current = current->next;
1588                 pthread_rwlock_unlock(&lock);
1589         }
1590         return ret;
1591 }
1592 #else
1593 static int invalid_dso_handle(void *h)
1594 {
1595         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1596         errflag = 1;
1597         return 1;
1598 }
1599 void *dlopen(const char *file, int mode)
1600 {
1601         return 0;
1602 }
1603 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1604 {
1605         return 0;
1606 }
1607 int __dladdr (const void *addr, Dl_info *info)
1608 {
1609         return 0;
1610 }
1611 #endif
1612
1613 int __dlinfo(void *dso, int req, void *res)
1614 {
1615         if (invalid_dso_handle(dso)) return -1;
1616         if (req != RTLD_DI_LINKMAP) {
1617                 snprintf(errbuf, sizeof errbuf, "Unsupported request %d", req);
1618                 errflag = 1;
1619                 return -1;
1620         }
1621         *(struct link_map **)res = dso;
1622         return 0;
1623 }
1624
1625 char *dlerror()
1626 {
1627         if (!errflag) return 0;
1628         errflag = 0;
1629         return errbuf;
1630 }
1631
1632 int dlclose(void *p)
1633 {
1634         return invalid_dso_handle(p);
1635 }