nsz Git - musl/blob - 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 #include "malloc_impl.h"
  24
  25 static void error(const char *, ...);
  26
  27 #define MAXP2(a,b) (-(-(a)&-(b)))
  28 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  29
  30 struct debug {
  31         int ver;
  32         void *head;
  33         void (*bp)(void);
  34         int state;
  35         void *base;
  36 };
  37
  38 struct td_index {
  39         size_t args[2];
  40         struct td_index *next;
  41 };
  42
  43 struct dso {
  44 #if DL_FDPIC
  45         struct fdpic_loadmap *loadmap;
  46 #else
  47         unsigned char *base;
  48 #endif
  49         char *name;
  50         size_t *dynv;
  51         struct dso *next, *prev;
  52
  53         Phdr *phdr;
  54         int phnum;
  55         size_t phentsize;
  56         Sym *syms;
  57         Elf_Symndx *hashtab;
  58         uint32_t *ghashtab;
  59         int16_t *versym;
  60         char *strings;
  61         struct dso *syms_next, *lazy_next;
  62         size_t *lazy, lazy_cnt;
  63         unsigned char *map;
  64         size_t map_len;
  65         dev_t dev;
  66         ino_t ino;
  67         char relocated;
  68         char constructed;
  69         char kernel_mapped;
  70         struct dso **deps, *needed_by;
  71         char *rpath_orig, *rpath;
  72         struct tls_module tls;
  73         size_t tls_id;
  74         size_t relro_start, relro_end;
  75         void **new_dtv;
  76         unsigned char *new_tls;
  77         volatile int new_dtv_idx, new_tls_idx;
  78         struct td_index *td_index;
  79         struct dso *fini_next;
  80         char *shortname;
  81 #if DL_FDPIC
  82         unsigned char *base;
  83 #else
  84         struct fdpic_loadmap *loadmap;
  85 #endif
  86         struct funcdesc {
  87                 void *addr;
  88                 size_t *got;
  89         } *funcdescs;
  90         size_t *got;
  91         char buf[];
  92 };
  93
  94 struct symdef {
  95         Sym *sym;
  96         struct dso *dso;
  97 };
  98
  99 static struct builtin_tls {
 100         char c;
 101         struct pthread pt;
 102         void *space[16];
 103 } builtin_tls[1];
 104 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
 105
 106 #define ADDEND_LIMIT 4096
 107 static size_t *saved_addends, *apply_addends_to;
 108
 109 static struct dso ldso;
 110 static struct dso *head, *tail, *fini_head, *syms_tail, *lazy_head;
 111 static char *env_path, *sys_path;
 112 static unsigned long long gencnt;
 113 static int runtime;
 114 static int ldd_mode;
 115 static int ldso_fail;
 116 static int noload;
 117 static jmp_buf *rtld_fail;
 118 static pthread_rwlock_t lock;
 119 static struct debug debug;
 120 static struct tls_module *tls_tail;
 121 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
 122 static size_t static_tls_cnt;
 123 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 124 static struct fdpic_loadmap *app_loadmap;
 125 static struct fdpic_dummy_loadmap app_dummy_loadmap;
 126 static struct dso *const nodeps_dummy;
 127
 128 struct debug *_dl_debug_addr = &debug;
 129
 130 extern hidden int __malloc_replaced;
 131
 132 hidden void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
 133
 134 extern hidden void (*const __init_array_end)(void), (*const __fini_array_end)(void);
 135
 136 weak_alias(__init_array_start, __init_array_end);
 137 weak_alias(__fini_array_start, __fini_array_end);
 138
 139 static int dl_strcmp(const char *l, const char *r)
 140 {
 141         for (; *l==*r && *l; l++, r++);
 142         return *(unsigned char *)l - *(unsigned char *)r;
 143 }
 144 #define strcmp(l,r) dl_strcmp(l,r)
 145
 146 /* Compute load address for a virtual address in a given dso. */
 147 #if DL_FDPIC
 148 static void *laddr(const struct dso *p, size_t v)
 149 {
 150         size_t j=0;
 151         if (!p->loadmap) return p->base + v;
 152         for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
 153         return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
 154 }
 155 static void *laddr_pg(const struct dso *p, size_t v)
 156 {
 157         size_t j=0;
 158         size_t pgsz = PAGE_SIZE;
 159         if (!p->loadmap) return p->base + v;
 160         for (j=0; ; j++) {
 161                 size_t a = p->loadmap->segs[j].p_vaddr;
 162                 size_t b = a + p->loadmap->segs[j].p_memsz;
 163                 a &= -pgsz;
 164                 b += pgsz-1;
 165                 b &= -pgsz;
 166                 if (v-a<b-a) break;
 167         }
 168         return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
 169 }
 170 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
 171         laddr(p, v), (p)->got })
 172 #else
 173 #define laddr(p, v) (void *)((p)->base + (v))
 174 #define laddr_pg(p, v) laddr(p, v)
 175 #define fpaddr(p, v) ((void (*)())laddr(p, v))
 176 #endif
 177
 178 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 179 {
 180         size_t i;
 181         for (i=0; i<cnt; i++) a[i] = 0;
 182         for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
 183                 a[0] |= 1UL<<v[0];
 184                 a[v[0]] = v[1];
 185         }
 186 }
 187
 188 static int search_vec(size_t *v, size_t *r, size_t key)
 189 {
 190         for (; v[0]!=key; v+=2)
 191                 if (!v[0]) return 0;
 192         *r = v[1];
 193         return 1;
 194 }
 195
 196 static uint32_t sysv_hash(const char *s0)
 197 {
 198         const unsigned char *s = (void *)s0;
 199         uint_fast32_t h = 0;
 200         while (*s) {
 201                 h = 16*h + *s++;
 202                 h ^= h>>24 & 0xf0;
 203         }
 204         return h & 0xfffffff;
 205 }
 206
 207 static uint32_t gnu_hash(const char *s0)
 208 {
 209         const unsigned char *s = (void *)s0;
 210         uint_fast32_t h = 5381;
 211         for (; *s; s++)
 212                 h += h*32 + *s;
 213         return h;
 214 }
 215
 216 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 217 {
 218         size_t i;
 219         Sym *syms = dso->syms;
 220         Elf_Symndx *hashtab = dso->hashtab;
 221         char *strings = dso->strings;
 222         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 223                 if ((!dso->versym || dso->versym[i] >= 0)
 224                     && (!strcmp(s, strings+syms[i].st_name)))
 225                         return syms+i;
 226         }
 227         return 0;
 228 }
 229
 230 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
 231 {
 232         uint32_t nbuckets = hashtab[0];
 233         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 234         uint32_t i = buckets[h1 % nbuckets];
 235
 236         if (!i) return 0;
 237
 238         uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
 239
 240         for (h1 |= 1; ; i++) {
 241                 uint32_t h2 = *hashval++;
 242                 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
 243                     && !strcmp(s, dso->strings + dso->syms[i].st_name))
 244                         return dso->syms+i;
 245                 if (h2 & 1) break;
 246         }
 247
 248         return 0;
 249 }
 250
 251 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
 252 {
 253         const size_t *bloomwords = (const void *)(hashtab+4);
 254         size_t f = bloomwords[fofs & (hashtab[2]-1)];
 255         if (!(f & fmask)) return 0;
 256
 257         f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
 258         if (!(f & 1)) return 0;
 259
 260         return gnu_lookup(h1, hashtab, dso, s);
 261 }
 262
 263 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 264 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 265
 266 #ifndef ARCH_SYM_REJECT_UND
 267 #define ARCH_SYM_REJECT_UND(s) 0
 268 #endif
 269
 270 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 271 {
 272         uint32_t h = 0, gh = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght;
 273         size_t ghm = 1ul << gh % (8*sizeof(size_t));
 274         struct symdef def = {0};
 275         for (; dso; dso=dso->syms_next) {
 276                 Sym *sym;
 277                 if ((ght = dso->ghashtab)) {
 278                         sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
 279                 } else {
 280                         if (!h) h = sysv_hash(s);
 281                         sym = sysv_lookup(s, h, dso);
 282                 }
 283                 if (!sym) continue;
 284                 if (!sym->st_shndx)
 285                         if (need_def || (sym->st_info&0xf) == STT_TLS
 286                             || ARCH_SYM_REJECT_UND(sym))
 287                                 continue;
 288                 if (!sym->st_value)
 289                         if ((sym->st_info&0xf) != STT_TLS)
 290                                 continue;
 291                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 292                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 293                 def.sym = sym;
 294                 def.dso = dso;
 295                 break;
 296         }
 297         return def;
 298 }
 299
 300 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 301 {
 302         unsigned char *base = dso->base;
 303         Sym *syms = dso->syms;
 304         char *strings = dso->strings;
 305         Sym *sym;
 306         const char *name;
 307         void *ctx;
 308         int type;
 309         int sym_index;
 310         struct symdef def;
 311         size_t *reloc_addr;
 312         size_t sym_val;
 313         size_t tls_val;
 314         size_t addend;
 315         int skip_relative = 0, reuse_addends = 0, save_slot = 0;
 316
 317         if (dso == &ldso) {
 318                 /* Only ldso's REL table needs addend saving/reuse. */
 319                 if (rel == apply_addends_to)
 320                         reuse_addends = 1;
 321                 skip_relative = 1;
 322         }
 323
 324         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 325                 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
 326                 type = R_TYPE(rel[1]);
 327                 if (type == REL_NONE) continue;
 328                 reloc_addr = laddr(dso, rel[0]);
 329
 330                 if (stride > 2) {
 331                         addend = rel[2];
 332                 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
 333                         addend = 0;
 334                 } else if (reuse_addends) {
 335                         /* Save original addend in stage 2 where the dso
 336                          * chain consists of just ldso; otherwise read back
 337                          * saved addend since the inline one was clobbered. */
 338                         if (head==&ldso)
 339                                 saved_addends[save_slot] = *reloc_addr;
 340                         addend = saved_addends[save_slot++];
 341                 } else {
 342                         addend = *reloc_addr;
 343                 }
 344
 345                 sym_index = R_SYM(rel[1]);
 346                 if (sym_index) {
 347                         sym = syms + sym_index;
 348                         name = strings + sym->st_name;
 349                         ctx = type==REL_COPY ? head->syms_next : head;
 350                         def = (sym->st_info&0xf) == STT_SECTION
 351                                 ? (struct symdef){ .dso = dso, .sym = sym }
 352                                 : find_sym(ctx, name, type==REL_PLT);
 353                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 354                             || sym->st_info>>4 != STB_WEAK)) {
 355                                 if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
 356                                         dso->lazy[3*dso->lazy_cnt+0] = rel[0];
 357                                         dso->lazy[3*dso->lazy_cnt+1] = rel[1];
 358                                         dso->lazy[3*dso->lazy_cnt+2] = addend;
 359                                         dso->lazy_cnt++;
 360                                         continue;
 361                                 }
 362                                 error("Error relocating %s: %s: symbol not found",
 363                                         dso->name, name);
 364                                 if (runtime) longjmp(*rtld_fail, 1);
 365                                 continue;
 366                         }
 367                 } else {
 368                         sym = 0;
 369                         def.sym = 0;
 370                         def.dso = dso;
 371                 }
 372
 373                 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
 374                 tls_val = def.sym ? def.sym->st_value : 0;
 375
 376                 if ((type == REL_TPOFF || type == REL_TPOFF_NEG)
 377                     && runtime && def.dso->tls_id > static_tls_cnt) {
 378                         error("Error relocating %s: %s: initial-exec TLS "
 379                                 "resolves to dynamic definition in %s",
 380                                 dso->name, name, def.dso->name);
 381                         longjmp(*rtld_fail, 1);
 382                 }
 383
 384                 switch(type) {
 385                 case REL_NONE:
 386                         break;
 387                 case REL_OFFSET:
 388                         addend -= (size_t)reloc_addr;
 389                 case REL_SYMBOLIC:
 390                 case REL_GOT:
 391                 case REL_PLT:
 392                         *reloc_addr = sym_val + addend;
 393                         break;
 394                 case REL_RELATIVE:
 395                         *reloc_addr = (size_t)base + addend;
 396                         break;
 397                 case REL_SYM_OR_REL:
 398                         if (sym) *reloc_addr = sym_val + addend;
 399                         else *reloc_addr = (size_t)base + addend;
 400                         break;
 401                 case REL_COPY:
 402                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 403                         break;
 404                 case REL_OFFSET32:
 405                         *(uint32_t *)reloc_addr = sym_val + addend
 406                                 - (size_t)reloc_addr;
 407                         break;
 408                 case REL_FUNCDESC:
 409                         *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
 410                                 + (def.sym - def.dso->syms)) : 0;
 411                         break;
 412                 case REL_FUNCDESC_VAL:
 413                         if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
 414                         else *reloc_addr = sym_val;
 415                         reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
 416                         break;
 417                 case REL_DTPMOD:
 418                         *reloc_addr = def.dso->tls_id;
 419                         break;
 420                 case REL_DTPOFF:
 421                         *reloc_addr = tls_val + addend - DTP_OFFSET;
 422                         break;
 423 #ifdef TLS_ABOVE_TP
 424                 case REL_TPOFF:
 425                         *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
 426                         break;
 427 #else
 428                 case REL_TPOFF:
 429                         *reloc_addr = tls_val - def.dso->tls.offset + addend;
 430                         break;
 431                 case REL_TPOFF_NEG:
 432                         *reloc_addr = def.dso->tls.offset - tls_val + addend;
 433                         break;
 434 #endif
 435                 case REL_TLSDESC:
 436                         if (stride<3) addend = reloc_addr[1];
 437                         if (runtime && def.dso->tls_id > static_tls_cnt) {
 438                                 struct td_index *new = malloc(sizeof *new);
 439                                 if (!new) {
 440                                         error(
 441                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 442                                         dso->name, sym ? name : "(local)" );
 443                                         longjmp(*rtld_fail, 1);
 444                                 }
 445                                 new->next = dso->td_index;
 446                                 dso->td_index = new;
 447                                 new->args[0] = def.dso->tls_id;
 448                                 new->args[1] = tls_val + addend;
 449                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 450                                 reloc_addr[1] = (size_t)new;
 451                         } else {
 452                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 453 #ifdef TLS_ABOVE_TP
 454                                 reloc_addr[1] = tls_val + def.dso->tls.offset
 455                                         + TPOFF_K + addend;
 456 #else
 457                                 reloc_addr[1] = tls_val - def.dso->tls.offset
 458                                         + addend;
 459 #endif
 460                         }
 461                         break;
 462                 default:
 463                         error("Error relocating %s: unsupported relocation type %d",
 464                                 dso->name, type);
 465                         if (runtime) longjmp(*rtld_fail, 1);
 466                         continue;
 467                 }
 468         }
 469 }
 470
 471 static void redo_lazy_relocs()
 472 {
 473         struct dso *p = lazy_head, *next;
 474         lazy_head = 0;
 475         for (; p; p=next) {
 476                 next = p->lazy_next;
 477                 size_t size = p->lazy_cnt*3*sizeof(size_t);
 478                 p->lazy_cnt = 0;
 479                 do_relocs(p, p->lazy, size, 3);
 480                 if (p->lazy_cnt) {
 481                         p->lazy_next = lazy_head;
 482                         lazy_head = p;
 483                 } else {
 484                         free(p->lazy);
 485                         p->lazy = 0;
 486                         p->lazy_next = 0;
 487                 }
 488         }
 489 }
 490
 491 /* A huge hack: to make up for the wastefulness of shared libraries
 492  * needing at least a page of dirty memory even if they have no global
 493  * data, we reclaim the gaps at the beginning and end of writable maps
 494  * and "donate" them to the heap. */
 495
 496 static void reclaim(struct dso *dso, size_t start, size_t end)
 497 {
 498         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 499         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 500         if (start >= end) return;
 501         char *base = laddr_pg(dso, start);
 502         __malloc_donate(base, base+(end-start));
 503 }
 504
 505 static void reclaim_gaps(struct dso *dso)
 506 {
 507         Phdr *ph = dso->phdr;
 508         size_t phcnt = dso->phnum;
 509
 510         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 511                 if (ph->p_type!=PT_LOAD) continue;
 512                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 513                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 514                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 515                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 516         }
 517 }
 518
 519 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
 520 {
 521         static int no_map_fixed;
 522         char *q;
 523         if (!no_map_fixed) {
 524                 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
 525                 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
 526                         return q;
 527                 no_map_fixed = 1;
 528         }
 529         /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
 530         if (flags & MAP_ANONYMOUS) {
 531                 memset(p, 0, n);
 532                 return p;
 533         }
 534         ssize_t r;
 535         if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
 536         for (q=p; n; q+=r, off+=r, n-=r) {
 537                 r = read(fd, q, n);
 538                 if (r < 0 && errno != EINTR) return MAP_FAILED;
 539                 if (!r) {
 540                         memset(q, 0, n);
 541                         break;
 542                 }
 543         }
 544         return p;
 545 }
 546
 547 static void unmap_library(struct dso *dso)
 548 {
 549         if (dso->loadmap) {
 550                 size_t i;
 551                 for (i=0; i<dso->loadmap->nsegs; i++) {
 552                         if (!dso->loadmap->segs[i].p_memsz)
 553                                 continue;
 554                         munmap((void *)dso->loadmap->segs[i].addr,
 555                                 dso->loadmap->segs[i].p_memsz);
 556                 }
 557                 free(dso->loadmap);
 558         } else if (dso->map && dso->map_len) {
 559                 munmap(dso->map, dso->map_len);
 560         }
 561 }
 562
 563 static void *map_library(int fd, struct dso *dso)
 564 {
 565         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 566         void *allocated_buf=0;
 567         size_t phsize;
 568         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 569         size_t this_min, this_max;
 570         size_t nsegs = 0;
 571         off_t off_start;
 572         Ehdr *eh;
 573         Phdr *ph, *ph0;
 574         unsigned prot;
 575         unsigned char *map=MAP_FAILED, *base;
 576         size_t dyn=0;
 577         size_t tls_image=0;
 578         size_t i;
 579
 580         ssize_t l = read(fd, buf, sizeof buf);
 581         eh = buf;
 582         if (l<0) return 0;
 583         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 584                 goto noexec;
 585         phsize = eh->e_phentsize * eh->e_phnum;
 586         if (phsize > sizeof buf - sizeof *eh) {
 587                 allocated_buf = malloc(phsize);
 588                 if (!allocated_buf) return 0;
 589                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 590                 if (l < 0) goto error;
 591                 if (l != phsize) goto noexec;
 592                 ph = ph0 = allocated_buf;
 593         } else if (eh->e_phoff + phsize > l) {
 594                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 595                 if (l < 0) goto error;
 596                 if (l != phsize) goto noexec;
 597                 ph = ph0 = (void *)(buf + 1);
 598         } else {
 599                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 600         }
 601         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 602                 if (ph->p_type == PT_DYNAMIC) {
 603                         dyn = ph->p_vaddr;
 604                 } else if (ph->p_type == PT_TLS) {
 605                         tls_image = ph->p_vaddr;
 606                         dso->tls.align = ph->p_align;
 607                         dso->tls.len = ph->p_filesz;
 608                         dso->tls.size = ph->p_memsz;
 609                 } else if (ph->p_type == PT_GNU_RELRO) {
 610                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 611                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 612                 }
 613                 if (ph->p_type != PT_LOAD) continue;
 614                 nsegs++;
 615                 if (ph->p_vaddr < addr_min) {
 616                         addr_min = ph->p_vaddr;
 617                         off_start = ph->p_offset;
 618                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 619                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 620                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 621                 }
 622                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 623                         addr_max = ph->p_vaddr+ph->p_memsz;
 624                 }
 625         }
 626         if (!dyn) goto noexec;
 627         if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
 628                 dso->loadmap = calloc(1, sizeof *dso->loadmap
 629                         + nsegs * sizeof *dso->loadmap->segs);
 630                 if (!dso->loadmap) goto error;
 631                 dso->loadmap->nsegs = nsegs;
 632                 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
 633                         if (ph->p_type != PT_LOAD) continue;
 634                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 635                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 636                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 637                         map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
 638                                 prot, MAP_PRIVATE,
 639                                 fd, ph->p_offset & -PAGE_SIZE);
 640                         if (map == MAP_FAILED) {
 641                                 unmap_library(dso);
 642                                 goto error;
 643                         }
 644                         dso->loadmap->segs[i].addr = (size_t)map +
 645                                 (ph->p_vaddr & PAGE_SIZE-1);
 646                         dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
 647                         dso->loadmap->segs[i].p_memsz = ph->p_memsz;
 648                         i++;
 649                         if (prot & PROT_WRITE) {
 650                                 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
 651                                         + ph->p_filesz;
 652                                 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
 653                                 size_t pgend = brk + ph->p_memsz - ph->p_filesz
 654                                         + PAGE_SIZE-1 & -PAGE_SIZE;
 655                                 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
 656                                         pgend-pgbrk, prot,
 657                                         MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
 658                                         -1, off_start) == MAP_FAILED)
 659                                         goto error;
 660                                 memset(map + brk, 0, pgbrk-brk);
 661                         }
 662                 }
 663                 map = (void *)dso->loadmap->segs[0].addr;
 664                 map_len = 0;
 665                 goto done_mapping;
 666         }
 667         addr_max += PAGE_SIZE-1;
 668         addr_max &= -PAGE_SIZE;
 669         addr_min &= -PAGE_SIZE;
 670         off_start &= -PAGE_SIZE;
 671         map_len = addr_max - addr_min + off_start;
 672         /* The first time, we map too much, possibly even more than
 673          * the length of the file. This is okay because we will not
 674          * use the invalid part; we just need to reserve the right
 675          * amount of virtual address space to map over later. */
 676         map = DL_NOMMU_SUPPORT
 677                 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
 678                         MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
 679                 : mmap((void *)addr_min, map_len, prot,
 680                         MAP_PRIVATE, fd, off_start);
 681         if (map==MAP_FAILED) goto error;
 682         dso->map = map;
 683         dso->map_len = map_len;
 684         /* If the loaded file is not relocatable and the requested address is
 685          * not available, then the load operation must fail. */
 686         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 687                 errno = EBUSY;
 688                 goto error;
 689         }
 690         base = map - addr_min;
 691         dso->phdr = 0;
 692         dso->phnum = 0;
 693         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 694                 if (ph->p_type != PT_LOAD) continue;
 695                 /* Check if the programs headers are in this load segment, and
 696                  * if so, record the address for use by dl_iterate_phdr. */
 697                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 698                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 699                         dso->phdr = (void *)(base + ph->p_vaddr
 700                                 + (eh->e_phoff-ph->p_offset));
 701                         dso->phnum = eh->e_phnum;
 702                         dso->phentsize = eh->e_phentsize;
 703                 }
 704                 this_min = ph->p_vaddr & -PAGE_SIZE;
 705                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 706                 off_start = ph->p_offset & -PAGE_SIZE;
 707                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 708                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 709                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 710                 /* Reuse the existing mapping for the lowest-address LOAD */
 711                 if ((ph->p_vaddr & -PAGE_SIZE) != addr_min || DL_NOMMU_SUPPORT)
 712                         if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 713                                 goto error;
 714                 if (ph->p_memsz > ph->p_filesz && (ph->p_flags&PF_W)) {
 715                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 716                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 717                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 718                         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)
 719                                 goto error;
 720                 }
 721         }
 722         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 723                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 724                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
 725                             && errno != ENOSYS)
 726                                 goto error;
 727                         break;
 728                 }
 729 done_mapping:
 730         dso->base = base;
 731         dso->dynv = laddr(dso, dyn);
 732         if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
 733         free(allocated_buf);
 734         return map;
 735 noexec:
 736         errno = ENOEXEC;
 737 error:
 738         if (map!=MAP_FAILED) unmap_library(dso);
 739         free(allocated_buf);
 740         return 0;
 741 }
 742
 743 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 744 {
 745         size_t l;
 746         int fd;
 747         for (;;) {
 748                 s += strspn(s, ":\n");
 749                 l = strcspn(s, ":\n");
 750                 if (l-1 >= INT_MAX) return -1;
 751                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
 752                         if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 753                         switch (errno) {
 754                         case ENOENT:
 755                         case ENOTDIR:
 756                         case EACCES:
 757                         case ENAMETOOLONG:
 758                                 break;
 759                         default:
 760                                 /* Any negative value but -1 will inhibit
 761                                  * futher path search. */
 762                                 return -2;
 763                         }
 764                 }
 765                 s += l;
 766         }
 767 }
 768
 769 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 770 {
 771         size_t n, l;
 772         const char *s, *t, *origin;
 773         char *d;
 774         if (p->rpath || !p->rpath_orig) return 0;
 775         if (!strchr(p->rpath_orig, '$')) {
 776                 p->rpath = p->rpath_orig;
 777                 return 0;
 778         }
 779         n = 0;
 780         s = p->rpath_orig;
 781         while ((t=strchr(s, '$'))) {
 782                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 783                         return 0;
 784                 s = t+1;
 785                 n++;
 786         }
 787         if (n > SSIZE_MAX/PATH_MAX) return 0;
 788
 789         if (p->kernel_mapped) {
 790                 /* $ORIGIN searches cannot be performed for the main program
 791                  * when it is suid/sgid/AT_SECURE. This is because the
 792                  * pathname is under the control of the caller of execve.
 793                  * For libraries, however, $ORIGIN can be processed safely
 794                  * since the library's pathname came from a trusted source
 795                  * (either system paths or a call to dlopen). */
 796                 if (libc.secure)
 797                         return 0;
 798                 l = readlink("/proc/self/exe", buf, buf_size);
 799                 if (l == -1) switch (errno) {
 800                 case ENOENT:
 801                 case ENOTDIR:
 802                 case EACCES:
 803                         break;
 804                 default:
 805                         return -1;
 806                 }
 807                 if (l >= buf_size)
 808                         return 0;
 809                 buf[l] = 0;
 810                 origin = buf;
 811         } else {
 812                 origin = p->name;
 813         }
 814         t = strrchr(origin, '/');
 815         if (t) {
 816                 l = t-origin;
 817         } else {
 818                 /* Normally p->name will always be an absolute or relative
 819                  * pathname containing at least one '/' character, but in the
 820                  * case where ldso was invoked as a command to execute a
 821                  * program in the working directory, app.name may not. Fix. */
 822                 origin = ".";
 823                 l = 1;
 824         }
 825         /* Disallow non-absolute origins for suid/sgid/AT_SECURE. */
 826         if (libc.secure && *origin != '/')
 827                 return 0;
 828         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 829         if (!p->rpath) return -1;
 830
 831         d = p->rpath;
 832         s = p->rpath_orig;
 833         while ((t=strchr(s, '$'))) {
 834                 memcpy(d, s, t-s);
 835                 d += t-s;
 836                 memcpy(d, origin, l);
 837                 d += l;
 838                 /* It was determined previously that the '$' is followed
 839                  * either by "ORIGIN" or "{ORIGIN}". */
 840                 s = t + 7 + 2*(t[1]=='{');
 841         }
 842         strcpy(d, s);
 843         return 0;
 844 }
 845
 846 static void decode_dyn(struct dso *p)
 847 {
 848         size_t dyn[DYN_CNT];
 849         decode_vec(p->dynv, dyn, DYN_CNT);
 850         p->syms = laddr(p, dyn[DT_SYMTAB]);
 851         p->strings = laddr(p, dyn[DT_STRTAB]);
 852         if (dyn[0]&(1<<DT_HASH))
 853                 p->hashtab = laddr(p, dyn[DT_HASH]);
 854         if (dyn[0]&(1<<DT_RPATH))
 855                 p->rpath_orig = p->strings + dyn[DT_RPATH];
 856         if (dyn[0]&(1<<DT_RUNPATH))
 857                 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
 858         if (dyn[0]&(1<<DT_PLTGOT))
 859                 p->got = laddr(p, dyn[DT_PLTGOT]);
 860         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 861                 p->ghashtab = laddr(p, *dyn);
 862         if (search_vec(p->dynv, dyn, DT_VERSYM))
 863                 p->versym = laddr(p, *dyn);
 864 }
 865
 866 static size_t count_syms(struct dso *p)
 867 {
 868         if (p->hashtab) return p->hashtab[1];
 869
 870         size_t nsym, i;
 871         uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
 872         uint32_t *hashval;
 873         for (i = nsym = 0; i < p->ghashtab[0]; i++) {
 874                 if (buckets[i] > nsym)
 875                         nsym = buckets[i];
 876         }
 877         if (nsym) {
 878                 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
 879                 do nsym++;
 880                 while (!(*hashval++ & 1));
 881         }
 882         return nsym;
 883 }
 884
 885 static void *dl_mmap(size_t n)
 886 {
 887         void *p;
 888         int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
 889 #ifdef SYS_mmap2
 890         p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
 891 #else
 892         p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
 893 #endif
 894         return p == MAP_FAILED ? 0 : p;
 895 }
 896
 897 static void makefuncdescs(struct dso *p)
 898 {
 899         static int self_done;
 900         size_t nsym = count_syms(p);
 901         size_t i, size = nsym * sizeof(*p->funcdescs);
 902
 903         if (!self_done) {
 904                 p->funcdescs = dl_mmap(size);
 905                 self_done = 1;
 906         } else {
 907                 p->funcdescs = malloc(size);
 908         }
 909         if (!p->funcdescs) {
 910                 if (!runtime) a_crash();
 911                 error("Error allocating function descriptors for %s", p->name);
 912                 longjmp(*rtld_fail, 1);
 913         }
 914         for (i=0; i<nsym; i++) {
 915                 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
 916                         p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
 917                         p->funcdescs[i].got = p->got;
 918                 } else {
 919                         p->funcdescs[i].addr = 0;
 920                         p->funcdescs[i].got = 0;
 921                 }
 922         }
 923 }
 924
 925 static struct dso *load_library(const char *name, struct dso *needed_by)
 926 {
 927         char buf[2*NAME_MAX+2];
 928         const char *pathname;
 929         unsigned char *map;
 930         struct dso *p, temp_dso = {0};
 931         int fd;
 932         struct stat st;
 933         size_t alloc_size;
 934         int n_th = 0;
 935         int is_self = 0;
 936
 937         if (!*name) {
 938                 errno = EINVAL;
 939                 return 0;
 940         }
 941
 942         /* Catch and block attempts to reload the implementation itself */
 943         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 944                 static const char reserved[] =
 945                         "c.pthread.rt.m.dl.util.xnet.";
 946                 const char *rp, *next;
 947                 for (rp=reserved; *rp; rp=next) {
 948                         next = strchr(rp, '.') + 1;
 949                         if (strncmp(name+3, rp, next-rp) == 0)
 950                                 break;
 951                 }
 952                 if (*rp) {
 953                         if (ldd_mode) {
 954                                 /* Track which names have been resolved
 955                                  * and only report each one once. */
 956                                 static unsigned reported;
 957                                 unsigned mask = 1U<<(rp-reserved);
 958                                 if (!(reported & mask)) {
 959                                         reported |= mask;
 960                                         dprintf(1, "\t%s => %s (%p)\n",
 961                                                 name, ldso.name,
 962                                                 ldso.base);
 963                                 }
 964                         }
 965                         is_self = 1;
 966                 }
 967         }
 968         if (!strcmp(name, ldso.name)) is_self = 1;
 969         if (is_self) {
 970                 if (!ldso.prev) {
 971                         tail->next = &ldso;
 972                         ldso.prev = tail;
 973                         tail = &ldso;
 974                 }
 975                 return &ldso;
 976         }
 977         if (strchr(name, '/')) {
 978                 pathname = name;
 979                 fd = open(name, O_RDONLY|O_CLOEXEC);
 980         } else {
 981                 /* Search for the name to see if it's already loaded */
 982                 for (p=head->next; p; p=p->next) {
 983                         if (p->shortname && !strcmp(p->shortname, name)) {
 984                                 return p;
 985                         }
 986                 }
 987                 if (strlen(name) > NAME_MAX) return 0;
 988                 fd = -1;
 989                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 990                 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
 991                         if (fixup_rpath(p, buf, sizeof buf) < 0)
 992                                 fd = -2; /* Inhibit further search. */
 993                         if (p->rpath)
 994                                 fd = path_open(name, p->rpath, buf, sizeof buf);
 995                 }
 996                 if (fd == -1) {
 997                         if (!sys_path) {
 998                                 char *prefix = 0;
 999                                 size_t prefix_len;
1000                                 if (ldso.name[0]=='/') {
1001                                         char *s, *t, *z;
1002                                         for (s=t=z=ldso.name; *s; s++)
1003                                                 if (*s=='/') z=t, t=s;
1004                                         prefix_len = z-ldso.name;
1005                                         if (prefix_len < PATH_MAX)
1006                                                 prefix = ldso.name;
1007                                 }
1008                                 if (!prefix) {
1009                                         prefix = "";
1010                                         prefix_len = 0;
1011                                 }
1012                                 char etc_ldso_path[prefix_len + 1
1013                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
1014                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
1015                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
1016                                         (int)prefix_len, prefix);
1017                                 FILE *f = fopen(etc_ldso_path, "rbe");
1018                                 if (f) {
1019                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
1020                                                 free(sys_path);
1021                                                 sys_path = "";
1022                                         }
1023                                         fclose(f);
1024                                 } else if (errno != ENOENT) {
1025                                         sys_path = "";
1026                                 }
1027                         }
1028                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
1029                         fd = path_open(name, sys_path, buf, sizeof buf);
1030                 }
1031                 pathname = buf;
1032         }
1033         if (fd < 0) return 0;
1034         if (fstat(fd, &st) < 0) {
1035                 close(fd);
1036                 return 0;
1037         }
1038         for (p=head->next; p; p=p->next) {
1039                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1040                         /* If this library was previously loaded with a
1041                          * pathname but a search found the same inode,
1042                          * setup its shortname so it can be found by name. */
1043                         if (!p->shortname && pathname != name)
1044                                 p->shortname = strrchr(p->name, '/')+1;
1045                         close(fd);
1046                         return p;
1047                 }
1048         }
1049         map = noload ? 0 : map_library(fd, &temp_dso);
1050         close(fd);
1051         if (!map) return 0;
1052
1053         /* Avoid the danger of getting two versions of libc mapped into the
1054          * same process when an absolute pathname was used. The symbols
1055          * checked are chosen to catch both musl and glibc, and to avoid
1056          * false positives from interposition-hack libraries. */
1057         decode_dyn(&temp_dso);
1058         if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
1059             find_sym(&temp_dso, "stdin", 1).sym) {
1060                 unmap_library(&temp_dso);
1061                 return load_library("libc.so", needed_by);
1062         }
1063         /* Past this point, if we haven't reached runtime yet, ldso has
1064          * committed either to use the mapped library or to abort execution.
1065          * Unmapping is not possible, so we can safely reclaim gaps. */
1066         if (!runtime) reclaim_gaps(&temp_dso);
1067
1068         /* Allocate storage for the new DSO. When there is TLS, this
1069          * storage must include a reservation for all pre-existing
1070          * threads to obtain copies of both the new TLS, and an
1071          * extended DTV capable of storing an additional slot for
1072          * the newly-loaded DSO. */
1073         alloc_size = sizeof *p + strlen(pathname) + 1;
1074         if (runtime && temp_dso.tls.image) {
1075                 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1076                         + sizeof(void *) * (tls_cnt+3);
1077                 n_th = libc.threads_minus_1 + 1;
1078                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1079                 else alloc_size += n_th * per_th;
1080         }
1081         p = calloc(1, alloc_size);
1082         if (!p) {
1083                 unmap_library(&temp_dso);
1084                 return 0;
1085         }
1086         memcpy(p, &temp_dso, sizeof temp_dso);
1087         p->dev = st.st_dev;
1088         p->ino = st.st_ino;
1089         p->needed_by = needed_by;
1090         p->name = p->buf;
1091         strcpy(p->name, pathname);
1092         /* Add a shortname only if name arg was not an explicit pathname. */
1093         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1094         if (p->tls.image) {
1095                 p->tls_id = ++tls_cnt;
1096                 tls_align = MAXP2(tls_align, p->tls.align);
1097 #ifdef TLS_ABOVE_TP
1098                 p->tls.offset = tls_offset + ( (tls_align-1) &
1099                         -(tls_offset + (uintptr_t)p->tls.image) );
1100                 tls_offset += p->tls.size;
1101 #else
1102                 tls_offset += p->tls.size + p->tls.align - 1;
1103                 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1104                         & (p->tls.align-1);
1105                 p->tls.offset = tls_offset;
1106 #endif
1107                 p->new_dtv = (void *)(-sizeof(size_t) &
1108                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1109                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1110                 if (tls_tail) tls_tail->next = &p->tls;
1111                 else libc.tls_head = &p->tls;
1112                 tls_tail = &p->tls;
1113         }
1114
1115         tail->next = p;
1116         p->prev = tail;
1117         tail = p;
1118
1119         if (DL_FDPIC) makefuncdescs(p);
1120
1121         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1122
1123         return p;
1124 }
1125
1126 static void load_deps(struct dso *p)
1127 {
1128         size_t i, ndeps=0;
1129         struct dso ***deps = &p->deps, **tmp, *dep;
1130         for (; p; p=p->next) {
1131                 for (i=0; p->dynv[i]; i+=2) {
1132                         if (p->dynv[i] != DT_NEEDED) continue;
1133                         dep = load_library(p->strings + p->dynv[i+1], p);
1134                         if (!dep) {
1135                                 error("Error loading shared library %s: %m (needed by %s)",
1136                                         p->strings + p->dynv[i+1], p->name);
1137                                 if (runtime) longjmp(*rtld_fail, 1);
1138                                 continue;
1139                         }
1140                         if (runtime) {
1141                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
1142                                 if (!tmp) longjmp(*rtld_fail, 1);
1143                                 tmp[ndeps++] = dep;
1144                                 tmp[ndeps] = 0;
1145                                 *deps = tmp;
1146                         }
1147                 }
1148         }
1149         if (!*deps) *deps = (struct dso **)&nodeps_dummy;
1150 }
1151
1152 static void load_preload(char *s)
1153 {
1154         int tmp;
1155         char *z;
1156         for (z=s; *z; s=z) {
1157                 for (   ; *s && (isspace(*s) || *s==':'); s++);
1158                 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1159                 tmp = *z;
1160                 *z = 0;
1161                 load_library(s, 0);
1162                 *z = tmp;
1163         }
1164 }
1165
1166 static void add_syms(struct dso *p)
1167 {
1168         if (!p->syms_next && syms_tail != p) {
1169                 syms_tail->syms_next = p;
1170                 syms_tail = p;
1171         }
1172 }
1173
1174 static void revert_syms(struct dso *old_tail)
1175 {
1176         struct dso *p, *next;
1177         /* Chop off the tail of the list of dsos that participate in
1178          * the global symbol table, reverting them to RTLD_LOCAL. */
1179         for (p=old_tail; p; p=next) {
1180                 next = p->syms_next;
1181                 p->syms_next = 0;
1182         }
1183         syms_tail = old_tail;
1184 }
1185
1186 static void do_mips_relocs(struct dso *p, size_t *got)
1187 {
1188         size_t i, j, rel[2];
1189         unsigned char *base = p->base;
1190         i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1191         if (p==&ldso) {
1192                 got += i;
1193         } else {
1194                 while (i--) *got++ += (size_t)base;
1195         }
1196         j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1197         i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1198         Sym *sym = p->syms + j;
1199         rel[0] = (unsigned char *)got - base;
1200         for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1201                 rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
1202                 do_relocs(p, rel, sizeof rel, 2);
1203         }
1204 }
1205
1206 static void reloc_all(struct dso *p)
1207 {
1208         size_t dyn[DYN_CNT];
1209         for (; p; p=p->next) {
1210                 if (p->relocated) continue;
1211                 decode_vec(p->dynv, dyn, DYN_CNT);
1212                 if (NEED_MIPS_GOT_RELOCS)
1213                         do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1214                 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1215                         2+(dyn[DT_PLTREL]==DT_RELA));
1216                 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1217                 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1218
1219                 if (head != &ldso && p->relro_start != p->relro_end &&
1220                     mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1221                     && errno != ENOSYS) {
1222                         error("Error relocating %s: RELRO protection failed: %m",
1223                                 p->name);
1224                         if (runtime) longjmp(*rtld_fail, 1);
1225                 }
1226
1227                 p->relocated = 1;
1228         }
1229 }
1230
1231 static void kernel_mapped_dso(struct dso *p)
1232 {
1233         size_t min_addr = -1, max_addr = 0, cnt;
1234         Phdr *ph = p->phdr;
1235         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1236                 if (ph->p_type == PT_DYNAMIC) {
1237                         p->dynv = laddr(p, ph->p_vaddr);
1238                 } else if (ph->p_type == PT_GNU_RELRO) {
1239                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1240                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1241                 }
1242                 if (ph->p_type != PT_LOAD) continue;
1243                 if (ph->p_vaddr < min_addr)
1244                         min_addr = ph->p_vaddr;
1245                 if (ph->p_vaddr+ph->p_memsz > max_addr)
1246                         max_addr = ph->p_vaddr+ph->p_memsz;
1247         }
1248         min_addr &= -PAGE_SIZE;
1249         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1250         p->map = p->base + min_addr;
1251         p->map_len = max_addr - min_addr;
1252         p->kernel_mapped = 1;
1253 }
1254
1255 void __libc_exit_fini()
1256 {
1257         struct dso *p;
1258         size_t dyn[DYN_CNT];
1259         for (p=fini_head; p; p=p->fini_next) {
1260                 if (!p->constructed) continue;
1261                 decode_vec(p->dynv, dyn, DYN_CNT);
1262                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1263                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1264                         size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1265                         while (n--) ((void (*)(void))*--fn)();
1266                 }
1267 #ifndef NO_LEGACY_INITFINI
1268                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1269                         fpaddr(p, dyn[DT_FINI])();
1270 #endif
1271         }
1272 }
1273
1274 static void do_init_fini(struct dso *p)
1275 {
1276         size_t dyn[DYN_CNT];
1277         int need_locking = libc.threads_minus_1;
1278         /* Allow recursive calls that arise when a library calls
1279          * dlopen from one of its constructors, but block any
1280          * other threads until all ctors have finished. */
1281         if (need_locking) pthread_mutex_lock(&init_fini_lock);
1282         for (; p; p=p->prev) {
1283                 if (p->constructed) continue;
1284                 p->constructed = 1;
1285                 decode_vec(p->dynv, dyn, DYN_CNT);
1286                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1287                         p->fini_next = fini_head;
1288                         fini_head = p;
1289                 }
1290 #ifndef NO_LEGACY_INITFINI
1291                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1292                         fpaddr(p, dyn[DT_INIT])();
1293 #endif
1294                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1295                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1296                         size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1297                         while (n--) ((void (*)(void))*fn++)();
1298                 }
1299                 if (!need_locking && libc.threads_minus_1) {
1300                         need_locking = 1;
1301                         pthread_mutex_lock(&init_fini_lock);
1302                 }
1303         }
1304         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1305 }
1306
1307 void __libc_start_init(void)
1308 {
1309         do_init_fini(tail);
1310 }
1311
1312 static void dl_debug_state(void)
1313 {
1314 }
1315
1316 weak_alias(dl_debug_state, _dl_debug_state);
1317
1318 void __init_tls(size_t *auxv)
1319 {
1320 }
1321
1322 hidden void *__tls_get_new(tls_mod_off_t *v)
1323 {
1324         pthread_t self = __pthread_self();
1325
1326         /* Block signals to make accessing new TLS async-signal-safe */
1327         sigset_t set;
1328         __block_all_sigs(&set);
1329         if (v[0]<=(size_t)self->dtv[0]) {
1330                 __restore_sigs(&set);
1331                 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1332         }
1333
1334         /* This is safe without any locks held because, if the caller
1335          * is able to request the Nth entry of the DTV, the DSO list
1336          * must be valid at least that far out and it was synchronized
1337          * at program startup or by an already-completed call to dlopen. */
1338         struct dso *p;
1339         for (p=head; p->tls_id != v[0]; p=p->next);
1340
1341         /* Get new DTV space from new DSO if needed */
1342         if (v[0] > (size_t)self->dtv[0]) {
1343                 void **newdtv = p->new_dtv +
1344                         (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
1345                 memcpy(newdtv, self->dtv,
1346                         ((size_t)self->dtv[0]+1) * sizeof(void *));
1347                 newdtv[0] = (void *)v[0];
1348                 self->dtv = self->dtv_copy = newdtv;
1349         }
1350
1351         /* Get new TLS memory from all new DSOs up to the requested one */
1352         unsigned char *mem;
1353         for (p=head; ; p=p->next) {
1354                 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1355                 mem = p->new_tls + (p->tls.size + p->tls.align)
1356                         * a_fetch_add(&p->new_tls_idx,1);
1357                 mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1358                         & (p->tls.align-1);
1359                 self->dtv[p->tls_id] = mem;
1360                 memcpy(mem, p->tls.image, p->tls.len);
1361                 if (p->tls_id == v[0]) break;
1362         }
1363         __restore_sigs(&set);
1364         return mem + v[1] + DTP_OFFSET;
1365 }
1366
1367 static void update_tls_size()
1368 {
1369         libc.tls_cnt = tls_cnt;
1370         libc.tls_align = tls_align;
1371         libc.tls_size = ALIGN(
1372                 (1+tls_cnt) * sizeof(void *) +
1373                 tls_offset +
1374                 sizeof(struct pthread) +
1375                 tls_align * 2,
1376         tls_align);
1377 }
1378
1379 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1380  * following stage 2 and stage 3 functions via primitive symbolic lookup
1381  * since it does not have access to their addresses to begin with. */
1382
1383 /* Stage 2 of the dynamic linker is called after relative relocations
1384  * have been processed. It can make function calls to static functions
1385  * and access string literals and static data, but cannot use extern
1386  * symbols. Its job is to perform symbolic relocations on the dynamic
1387  * linker itself, but some of the relocations performed may need to be
1388  * replaced later due to copy relocations in the main program. */
1389
1390 hidden void __dls2(unsigned char *base, size_t *sp)
1391 {
1392         if (DL_FDPIC) {
1393                 void *p1 = (void *)sp[-2];
1394                 void *p2 = (void *)sp[-1];
1395                 if (!p1) {
1396                         size_t *auxv, aux[AUX_CNT];
1397                         for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
1398                         decode_vec(auxv, aux, AUX_CNT);
1399                         if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1400                         else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1401                 }
1402                 app_loadmap = p2 ? p1 : 0;
1403                 ldso.loadmap = p2 ? p2 : p1;
1404                 ldso.base = laddr(&ldso, 0);
1405         } else {
1406                 ldso.base = base;
1407         }
1408         Ehdr *ehdr = (void *)ldso.base;
1409         ldso.name = ldso.shortname = "libc.so";
1410         ldso.phnum = ehdr->e_phnum;
1411         ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1412         ldso.phentsize = ehdr->e_phentsize;
1413         kernel_mapped_dso(&ldso);
1414         decode_dyn(&ldso);
1415
1416         if (DL_FDPIC) makefuncdescs(&ldso);
1417
1418         /* Prepare storage for to save clobbered REL addends so they
1419          * can be reused in stage 3. There should be very few. If
1420          * something goes wrong and there are a huge number, abort
1421          * instead of risking stack overflow. */
1422         size_t dyn[DYN_CNT];
1423         decode_vec(ldso.dynv, dyn, DYN_CNT);
1424         size_t *rel = laddr(&ldso, dyn[DT_REL]);
1425         size_t rel_size = dyn[DT_RELSZ];
1426         size_t symbolic_rel_cnt = 0;
1427         apply_addends_to = rel;
1428         for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1429                 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1430         if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1431         size_t addends[symbolic_rel_cnt+1];
1432         saved_addends = addends;
1433
1434         head = &ldso;
1435         reloc_all(&ldso);
1436
1437         ldso.relocated = 0;
1438
1439         /* Call dynamic linker stage-3, __dls3, looking it up
1440          * symbolically as a barrier against moving the address
1441          * load across the above relocation processing. */
1442         struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1443         if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1444         else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1445 }
1446
1447 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1448  * fully functional. Its job is to load (if not already loaded) and
1449  * process dependencies and relocations for the main application and
1450  * transfer control to its entry point. */
1451
1452 _Noreturn void __dls3(size_t *sp)
1453 {
1454         static struct dso app, vdso;
1455         size_t aux[AUX_CNT], *auxv;
1456         size_t i;
1457         char *env_preload=0;
1458         char *replace_argv0=0;
1459         size_t vdso_base;
1460         int argc = *sp;
1461         char **argv = (void *)(sp+1);
1462         char **argv_orig = argv;
1463         char **envp = argv+argc+1;
1464
1465         /* Find aux vector just past environ[] and use it to initialize
1466          * global data that may be needed before we can make syscalls. */
1467         __environ = envp;
1468         for (i=argc+1; argv[i]; i++);
1469         libc.auxv = auxv = (void *)(argv+i+1);
1470         decode_vec(auxv, aux, AUX_CNT);
1471         __hwcap = aux[AT_HWCAP];
1472         libc.page_size = aux[AT_PAGESZ];
1473         libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1474                 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1475
1476         /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1477          * use during dynamic linking. If possible it will also serve as the
1478          * thread pointer at runtime. */
1479         libc.tls_size = sizeof builtin_tls;
1480         libc.tls_align = tls_align;
1481         if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1482                 a_crash();
1483         }
1484
1485         /* Only trust user/env if kernel says we're not suid/sgid */
1486         if (!libc.secure) {
1487                 env_path = getenv("LD_LIBRARY_PATH");
1488                 env_preload = getenv("LD_PRELOAD");
1489         }
1490
1491         /* If the main program was already loaded by the kernel,
1492          * AT_PHDR will point to some location other than the dynamic
1493          * linker's program headers. */
1494         if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1495                 size_t interp_off = 0;
1496                 size_t tls_image = 0;
1497                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1498                 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1499                 app.phnum = aux[AT_PHNUM];
1500                 app.phentsize = aux[AT_PHENT];
1501                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1502                         if (phdr->p_type == PT_PHDR)
1503                                 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1504                         else if (phdr->p_type == PT_INTERP)
1505                                 interp_off = (size_t)phdr->p_vaddr;
1506                         else if (phdr->p_type == PT_TLS) {
1507                                 tls_image = phdr->p_vaddr;
1508                                 app.tls.len = phdr->p_filesz;
1509                                 app.tls.size = phdr->p_memsz;
1510                                 app.tls.align = phdr->p_align;
1511                         }
1512                 }
1513                 if (DL_FDPIC) app.loadmap = app_loadmap;
1514                 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1515                 if (interp_off) ldso.name = laddr(&app, interp_off);
1516                 if ((aux[0] & (1UL<<AT_EXECFN))
1517                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1518                         app.name = (char *)aux[AT_EXECFN];
1519                 else
1520                         app.name = argv[0];
1521                 kernel_mapped_dso(&app);
1522         } else {
1523                 int fd;
1524                 char *ldname = argv[0];
1525                 size_t l = strlen(ldname);
1526                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1527                 argv++;
1528                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1529                         char *opt = argv[0]+2;
1530                         *argv++ = (void *)-1;
1531                         if (!*opt) {
1532                                 break;
1533                         } else if (!memcmp(opt, "list", 5)) {
1534                                 ldd_mode = 1;
1535                         } else if (!memcmp(opt, "library-path", 12)) {
1536                                 if (opt[12]=='=') env_path = opt+13;
1537                                 else if (opt[12]) *argv = 0;
1538                                 else if (*argv) env_path = *argv++;
1539                         } else if (!memcmp(opt, "preload", 7)) {
1540                                 if (opt[7]=='=') env_preload = opt+8;
1541                                 else if (opt[7]) *argv = 0;
1542                                 else if (*argv) env_preload = *argv++;
1543                         } else if (!memcmp(opt, "argv0", 5)) {
1544                                 if (opt[5]=='=') replace_argv0 = opt+6;
1545                                 else if (opt[5]) *argv = 0;
1546                                 else if (*argv) replace_argv0 = *argv++;
1547                         } else {
1548                                 argv[0] = 0;
1549                         }
1550                 }
1551                 argv[-1] = (void *)(argc - (argv-argv_orig));
1552                 if (!argv[0]) {
1553                         dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1554                                 "Version %s\n"
1555                                 "Dynamic Program Loader\n"
1556                                 "Usage: %s [options] [--] pathname%s\n",
1557                                 __libc_version, ldname,
1558                                 ldd_mode ? "" : " [args]");
1559                         _exit(1);
1560                 }
1561                 fd = open(argv[0], O_RDONLY);
1562                 if (fd < 0) {
1563                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1564                         _exit(1);
1565                 }
1566                 Ehdr *ehdr = (void *)map_library(fd, &app);
1567                 if (!ehdr) {
1568                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1569                         _exit(1);
1570                 }
1571                 close(fd);
1572                 ldso.name = ldname;
1573                 app.name = argv[0];
1574                 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1575                 /* Find the name that would have been used for the dynamic
1576                  * linker had ldd not taken its place. */
1577                 if (ldd_mode) {
1578                         for (i=0; i<app.phnum; i++) {
1579                                 if (app.phdr[i].p_type == PT_INTERP)
1580                                         ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1581                         }
1582                         dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1583                 }
1584         }
1585         if (app.tls.size) {
1586                 libc.tls_head = tls_tail = &app.tls;
1587                 app.tls_id = tls_cnt = 1;
1588 #ifdef TLS_ABOVE_TP
1589                 app.tls.offset = GAP_ABOVE_TP;
1590                 app.tls.offset += -GAP_ABOVE_TP & (app.tls.align-1);
1591                 tls_offset = app.tls.offset + app.tls.size
1592                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1593                         & (app.tls.align-1) );
1594 #else
1595                 tls_offset = app.tls.offset = app.tls.size
1596                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1597                         & (app.tls.align-1) );
1598 #endif
1599                 tls_align = MAXP2(tls_align, app.tls.align);
1600         }
1601         decode_dyn(&app);
1602         if (DL_FDPIC) {
1603                 makefuncdescs(&app);
1604                 if (!app.loadmap) {
1605                         app.loadmap = (void *)&app_dummy_loadmap;
1606                         app.loadmap->nsegs = 1;
1607                         app.loadmap->segs[0].addr = (size_t)app.map;
1608                         app.loadmap->segs[0].p_vaddr = (size_t)app.map
1609                                 - (size_t)app.base;
1610                         app.loadmap->segs[0].p_memsz = app.map_len;
1611                 }
1612                 argv[-3] = (void *)app.loadmap;
1613         }
1614
1615         /* Initial dso chain consists only of the app. */
1616         head = tail = syms_tail = &app;
1617
1618         /* Donate unused parts of app and library mapping to malloc */
1619         reclaim_gaps(&app);
1620         reclaim_gaps(&ldso);
1621
1622         /* Load preload/needed libraries, add symbols to global namespace. */
1623         if (env_preload) load_preload(env_preload);
1624         load_deps(&app);
1625         for (struct dso *p=head; p; p=p->next)
1626                 add_syms(p);
1627
1628         /* Attach to vdso, if provided by the kernel, last so that it does
1629          * not become part of the global namespace.  */
1630         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
1631                 Ehdr *ehdr = (void *)vdso_base;
1632                 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1633                 vdso.phnum = ehdr->e_phnum;
1634                 vdso.phentsize = ehdr->e_phentsize;
1635                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1636                         if (phdr->p_type == PT_DYNAMIC)
1637                                 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1638                         if (phdr->p_type == PT_LOAD)
1639                                 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1640                 }
1641                 vdso.name = "";
1642                 vdso.shortname = "linux-gate.so.1";
1643                 vdso.relocated = 1;
1644                 decode_dyn(&vdso);
1645                 vdso.prev = tail;
1646                 tail->next = &vdso;
1647                 tail = &vdso;
1648         }
1649
1650         for (i=0; app.dynv[i]; i+=2) {
1651                 if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
1652                         app.dynv[i+1] = (size_t)&debug;
1653                 if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
1654                         size_t *ptr = (size_t *) app.dynv[i+1];
1655                         *ptr = (size_t)&debug;
1656                 }
1657         }
1658
1659         /* The main program must be relocated LAST since it may contin
1660          * copy relocations which depend on libraries' relocations. */
1661         reloc_all(app.next);
1662         reloc_all(&app);
1663
1664         update_tls_size();
1665         if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1666                 void *initial_tls = calloc(libc.tls_size, 1);
1667                 if (!initial_tls) {
1668                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1669                                 argv[0], libc.tls_size);
1670                         _exit(127);
1671                 }
1672                 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1673                         a_crash();
1674                 }
1675         } else {
1676                 size_t tmp_tls_size = libc.tls_size;
1677                 pthread_t self = __pthread_self();
1678                 /* Temporarily set the tls size to the full size of
1679                  * builtin_tls so that __copy_tls will use the same layout
1680                  * as it did for before. Then check, just to be safe. */
1681                 libc.tls_size = sizeof builtin_tls;
1682                 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1683                 libc.tls_size = tmp_tls_size;
1684         }
1685         static_tls_cnt = tls_cnt;
1686
1687         if (ldso_fail) _exit(127);
1688         if (ldd_mode) _exit(0);
1689
1690         /* Determine if malloc was interposed by a replacement implementation
1691          * so that calloc and the memalign family can harden against the
1692          * possibility of incomplete replacement. */
1693         if (find_sym(head, "malloc", 1).dso != &ldso)
1694                 __malloc_replaced = 1;
1695
1696         /* Switch to runtime mode: any further failures in the dynamic
1697          * linker are a reportable failure rather than a fatal startup
1698          * error. */
1699         runtime = 1;
1700
1701         debug.ver = 1;
1702         debug.bp = dl_debug_state;
1703         debug.head = head;
1704         debug.base = ldso.base;
1705         debug.state = 0;
1706         _dl_debug_state();
1707
1708         if (replace_argv0) argv[0] = replace_argv0;
1709
1710         errno = 0;
1711
1712         CRTJMP((void *)aux[AT_ENTRY], argv-1);
1713         for(;;);
1714 }
1715
1716 static void prepare_lazy(struct dso *p)
1717 {
1718         size_t dyn[DYN_CNT], n, flags1=0;
1719         decode_vec(p->dynv, dyn, DYN_CNT);
1720         search_vec(p->dynv, &flags1, DT_FLAGS_1);
1721         if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
1722                 return;
1723         n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
1724         if (NEED_MIPS_GOT_RELOCS) {
1725                 size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1726                 size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1727                 n += i-j;
1728         }
1729         p->lazy = calloc(n, 3*sizeof(size_t));
1730         if (!p->lazy) {
1731                 error("Error preparing lazy relocation for %s: %m", p->name);
1732                 longjmp(*rtld_fail, 1);
1733         }
1734         p->lazy_next = lazy_head;
1735         lazy_head = p;
1736 }
1737
1738 void *dlopen(const char *file, int mode)
1739 {
1740         struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
1741         struct tls_module *orig_tls_tail;
1742         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1743         size_t i;
1744         int cs;
1745         jmp_buf jb;
1746
1747         if (!file) return head;
1748
1749         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1750         pthread_rwlock_wrlock(&lock);
1751         __inhibit_ptc();
1752
1753         p = 0;
1754         orig_tls_tail = tls_tail;
1755         orig_tls_cnt = tls_cnt;
1756         orig_tls_offset = tls_offset;
1757         orig_tls_align = tls_align;
1758         orig_lazy_head = lazy_head;
1759         orig_syms_tail = syms_tail;
1760         orig_tail = tail;
1761         noload = mode & RTLD_NOLOAD;
1762
1763         rtld_fail = &jb;
1764         if (setjmp(*rtld_fail)) {
1765                 /* Clean up anything new that was (partially) loaded */
1766                 revert_syms(orig_syms_tail);
1767                 for (p=orig_tail->next; p; p=next) {
1768                         next = p->next;
1769                         while (p->td_index) {
1770                                 void *tmp = p->td_index->next;
1771                                 free(p->td_index);
1772                                 p->td_index = tmp;
1773                         }
1774                         free(p->funcdescs);
1775                         if (p->rpath != p->rpath_orig)
1776                                 free(p->rpath);
1777                         if (p->deps != &nodeps_dummy)
1778                                 free(p->deps);
1779                         unmap_library(p);
1780                         free(p);
1781                 }
1782                 if (!orig_tls_tail) libc.tls_head = 0;
1783                 tls_tail = orig_tls_tail;
1784                 if (tls_tail) tls_tail->next = 0;
1785                 tls_cnt = orig_tls_cnt;
1786                 tls_offset = orig_tls_offset;
1787                 tls_align = orig_tls_align;
1788                 lazy_head = orig_lazy_head;
1789                 tail = orig_tail;
1790                 tail->next = 0;
1791                 p = 0;
1792                 goto end;
1793         } else p = load_library(file, head);
1794
1795         if (!p) {
1796                 error(noload ?
1797                         "Library %s is not already loaded" :
1798                         "Error loading shared library %s: %m",
1799                         file);
1800                 goto end;
1801         }
1802
1803         /* First load handling */
1804         int first_load = !p->deps;
1805         if (first_load) {
1806                 load_deps(p);
1807                 if (!p->relocated && (mode & RTLD_LAZY)) {
1808                         prepare_lazy(p);
1809                         for (i=0; p->deps[i]; i++)
1810                                 if (!p->deps[i]->relocated)
1811                                         prepare_lazy(p->deps[i]);
1812                 }
1813         }
1814         if (first_load || (mode & RTLD_GLOBAL)) {
1815                 /* Make new symbols global, at least temporarily, so we can do
1816                  * relocations. If not RTLD_GLOBAL, this is reverted below. */
1817                 add_syms(p);
1818                 for (i=0; p->deps[i]; i++)
1819                         add_syms(p->deps[i]);
1820         }
1821         if (first_load) {
1822                 reloc_all(p);
1823         }
1824
1825         /* If RTLD_GLOBAL was not specified, undo any new additions
1826          * to the global symbol table. This is a nop if the library was
1827          * previously loaded and already global. */
1828         if (!(mode & RTLD_GLOBAL))
1829                 revert_syms(orig_syms_tail);
1830
1831         /* Processing of deferred lazy relocations must not happen until
1832          * the new libraries are committed; otherwise we could end up with
1833          * relocations resolved to symbol definitions that get removed. */
1834         redo_lazy_relocs();
1835
1836         update_tls_size();
1837         _dl_debug_state();
1838         orig_tail = tail;
1839 end:
1840         __release_ptc();
1841         if (p) gencnt++;
1842         pthread_rwlock_unlock(&lock);
1843         if (p) do_init_fini(orig_tail);
1844         pthread_setcancelstate(cs, 0);
1845         return p;
1846 }
1847
1848 hidden int __dl_invalid_handle(void *h)
1849 {
1850         struct dso *p;
1851         for (p=head; p; p=p->next) if (h==p) return 0;
1852         error("Invalid library handle %p", (void *)h);
1853         return 1;
1854 }
1855
1856 static void *addr2dso(size_t a)
1857 {
1858         struct dso *p;
1859         size_t i;
1860         if (DL_FDPIC) for (p=head; p; p=p->next) {
1861                 i = count_syms(p);
1862                 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
1863                         return p;
1864         }
1865         for (p=head; p; p=p->next) {
1866                 if (DL_FDPIC && p->loadmap) {
1867                         for (i=0; i<p->loadmap->nsegs; i++) {
1868                                 if (a-p->loadmap->segs[i].p_vaddr
1869                                     < p->loadmap->segs[i].p_memsz)
1870                                         return p;
1871                         }
1872                 } else {
1873                         Phdr *ph = p->phdr;
1874                         size_t phcnt = p->phnum;
1875                         size_t entsz = p->phentsize;
1876                         size_t base = (size_t)p->base;
1877                         for (; phcnt--; ph=(void *)((char *)ph+entsz)) {
1878                                 if (ph->p_type != PT_LOAD) continue;
1879                                 if (a-base-ph->p_vaddr < ph->p_memsz)
1880                                         return p;
1881                         }
1882                         if (a-(size_t)p->map < p->map_len)
1883                                 return 0;
1884                 }
1885         }
1886         return 0;
1887 }
1888
1889 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1890 {
1891         size_t i;
1892         uint32_t h = 0, gh = 0, *ght;
1893         Sym *sym;
1894         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1895                 if (p == RTLD_DEFAULT) {
1896                         p = head;
1897                 } else if (p == RTLD_NEXT) {
1898                         p = addr2dso((size_t)ra);
1899                         if (!p) p=head;
1900                         p = p->next;
1901                 }
1902                 struct symdef def = find_sym(p, s, 0);
1903                 if (!def.sym) goto failed;
1904                 if ((def.sym->st_info&0xf) == STT_TLS)
1905                         return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value});
1906                 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
1907                         return def.dso->funcdescs + (def.sym - def.dso->syms);
1908                 return laddr(def.dso, def.sym->st_value);
1909         }
1910         if (__dl_invalid_handle(p))
1911                 return 0;
1912         if ((ght = p->ghashtab)) {
1913                 gh = gnu_hash(s);
1914                 sym = gnu_lookup(gh, ght, p, s);
1915         } else {
1916                 h = sysv_hash(s);
1917                 sym = sysv_lookup(s, h, p);
1918         }
1919         if (sym && (sym->st_info&0xf) == STT_TLS)
1920                 return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value});
1921         if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1922                 return p->funcdescs + (sym - p->syms);
1923         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1924                 return laddr(p, sym->st_value);
1925         for (i=0; p->deps[i]; i++) {
1926                 if ((ght = p->deps[i]->ghashtab)) {
1927                         if (!gh) gh = gnu_hash(s);
1928                         sym = gnu_lookup(gh, ght, p->deps[i], s);
1929                 } else {
1930                         if (!h) h = sysv_hash(s);
1931                         sym = sysv_lookup(s, h, p->deps[i]);
1932                 }
1933                 if (sym && (sym->st_info&0xf) == STT_TLS)
1934                         return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value});
1935                 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1936                         return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
1937                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1938                         return laddr(p->deps[i], sym->st_value);
1939         }
1940 failed:
1941         error("Symbol not found: %s", s);
1942         return 0;
1943 }
1944
1945 int dladdr(const void *addr_arg, Dl_info *info)
1946 {
1947         size_t addr = (size_t)addr_arg;
1948         struct dso *p;
1949         Sym *sym, *bestsym;
1950         uint32_t nsym;
1951         char *strings;
1952         size_t best = 0;
1953         size_t besterr = -1;
1954
1955         pthread_rwlock_rdlock(&lock);
1956         p = addr2dso(addr);
1957         pthread_rwlock_unlock(&lock);
1958
1959         if (!p) return 0;
1960
1961         sym = p->syms;
1962         strings = p->strings;
1963         nsym = count_syms(p);
1964
1965         if (DL_FDPIC) {
1966                 size_t idx = (addr-(size_t)p->funcdescs)
1967                         / sizeof(*p->funcdescs);
1968                 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
1969                         best = (size_t)(p->funcdescs + idx);
1970                         bestsym = sym + idx;
1971                         besterr = 0;
1972                 }
1973         }
1974
1975         if (!best) for (; nsym; nsym--, sym++) {
1976                 if (sym->st_value
1977                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1978                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1979                         size_t symaddr = (size_t)laddr(p, sym->st_value);
1980                         if (symaddr > addr || symaddr <= best)
1981                                 continue;
1982                         best = symaddr;
1983                         bestsym = sym;
1984                         besterr = addr - symaddr;
1985                         if (addr == symaddr)
1986                                 break;
1987                 }
1988         }
1989
1990         if (bestsym && besterr > bestsym->st_size-1) {
1991                 best = 0;
1992                 bestsym = 0;
1993         }
1994
1995         info->dli_fname = p->name;
1996         info->dli_fbase = p->map;
1997
1998         if (!best) {
1999                 info->dli_sname = 0;
2000                 info->dli_saddr = 0;
2001                 return 1;
2002         }
2003
2004         if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
2005                 best = (size_t)(p->funcdescs + (bestsym - p->syms));
2006         info->dli_sname = strings + bestsym->st_name;
2007         info->dli_saddr = (void *)best;
2008
2009         return 1;
2010 }
2011
2012 hidden void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
2013 {
2014         void *res;
2015         pthread_rwlock_rdlock(&lock);
2016         res = do_dlsym(p, s, ra);
2017         pthread_rwlock_unlock(&lock);
2018         return res;
2019 }
2020
2021 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
2022 {
2023         struct dso *current;
2024         struct dl_phdr_info info;
2025         int ret = 0;
2026         for(current = head; current;) {
2027                 info.dlpi_addr      = (uintptr_t)current->base;
2028                 info.dlpi_name      = current->name;
2029                 info.dlpi_phdr      = current->phdr;
2030                 info.dlpi_phnum     = current->phnum;
2031                 info.dlpi_adds      = gencnt;
2032                 info.dlpi_subs      = 0;
2033                 info.dlpi_tls_modid = current->tls_id;
2034                 info.dlpi_tls_data  = current->tls.image;
2035
2036                 ret = (callback)(&info, sizeof (info), data);
2037
2038                 if (ret != 0) break;
2039
2040                 pthread_rwlock_rdlock(&lock);
2041                 current = current->next;
2042                 pthread_rwlock_unlock(&lock);
2043         }
2044         return ret;
2045 }
2046
2047 static void error(const char *fmt, ...)
2048 {
2049         va_list ap;
2050         va_start(ap, fmt);
2051         if (!runtime) {
2052                 vdprintf(2, fmt, ap);
2053                 dprintf(2, "\n");
2054                 ldso_fail = 1;
2055                 va_end(ap);
2056                 return;
2057         }
2058         __dl_vseterr(fmt, ap);
2059         va_end(ap);
2060 }