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 #include "dynlink.h"
  23
  24 static void error(const char *, ...);
  25
  26 #ifdef SHARED
  27
  28 #define MAXP2(a,b) (-(-(a)&-(b)))
  29 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  30
  31 struct debug {
  32         int ver;
  33         void *head;
  34         void (*bp)(void);
  35         int state;
  36         void *base;
  37 };
  38
  39 struct td_index {
  40         size_t args[2];
  41         struct td_index *next;
  42 };
  43
  44 struct dso {
  45 #if DL_FDPIC
  46         struct fdpic_loadmap *loadmap;
  47 #else
  48         unsigned char *base;
  49 #endif
  50         char *name;
  51         size_t *dynv;
  52         struct dso *next, *prev;
  53
  54         Phdr *phdr;
  55         int phnum;
  56         size_t phentsize;
  57         int refcnt;
  58         Sym *syms;
  59         uint32_t *hashtab;
  60         uint32_t *ghashtab;
  61         int16_t *versym;
  62         char *strings;
  63         unsigned char *map;
  64         size_t map_len;
  65         dev_t dev;
  66         ino_t ino;
  67         signed char global;
  68         char relocated;
  69         char constructed;
  70         char kernel_mapped;
  71         struct dso **deps, *needed_by;
  72         char *rpath_orig, *rpath;
  73         void *tls_image;
  74         size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
  75         size_t relro_start, relro_end;
  76         void **new_dtv;
  77         unsigned char *new_tls;
  78         volatile int new_dtv_idx, new_tls_idx;
  79         struct td_index *td_index;
  80         struct dso *fini_next;
  81         char *shortname;
  82 #if DL_FDPIC
  83         unsigned char *base;
  84 #else
  85         struct fdpic_loadmap *loadmap;
  86 #endif
  87         struct funcdesc {
  88                 void *addr;
  89                 size_t *got;
  90         } *funcdescs;
  91         size_t *got;
  92         char buf[];
  93 };
  94
  95 struct symdef {
  96         Sym *sym;
  97         struct dso *dso;
  98 };
  99
 100 int __init_tp(void *);
 101 void __init_libc(char **, char *);
 102
 103 const char *__libc_get_version(void);
 104
 105 static struct builtin_tls {
 106         char c;
 107         struct pthread pt;
 108         void *space[16];
 109 } builtin_tls[1];
 110 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
 111
 112 #define ADDEND_LIMIT 4096
 113 static size_t *saved_addends, *apply_addends_to;
 114
 115 static struct dso ldso;
 116 static struct dso *head, *tail, *fini_head;
 117 static char *env_path, *sys_path;
 118 static unsigned long long gencnt;
 119 static int runtime;
 120 static int ldd_mode;
 121 static int ldso_fail;
 122 static int noload;
 123 static jmp_buf *rtld_fail;
 124 static pthread_rwlock_t lock;
 125 static struct debug debug;
 126 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
 127 static size_t static_tls_cnt;
 128 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 129 static struct fdpic_loadmap *app_loadmap;
 130 static struct fdpic_dummy_loadmap app_dummy_loadmap;
 131
 132 struct debug *_dl_debug_addr = &debug;
 133
 134 static int dl_strcmp(const char *l, const char *r)
 135 {
 136         for (; *l==*r && *l; l++, r++);
 137         return *(unsigned char *)l - *(unsigned char *)r;
 138 }
 139 #define strcmp(l,r) dl_strcmp(l,r)
 140
 141 /* Compute load address for a virtual address in a given dso. */
 142 #if DL_FDPIC
 143 static void *laddr(const struct dso *p, size_t v)
 144 {
 145         size_t j=0;
 146         if (!p->loadmap) return p->base + v;
 147         for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
 148         return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
 149 }
 150 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
 151         laddr(p, v), (p)->got })
 152 #else
 153 #define laddr(p, v) (void *)((p)->base + (v))
 154 #define fpaddr(p, v) ((void (*)())laddr(p, v))
 155 #endif
 156
 157 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 158 {
 159         size_t i;
 160         for (i=0; i<cnt; i++) a[i] = 0;
 161         for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
 162                 a[0] |= 1UL<<v[0];
 163                 a[v[0]] = v[1];
 164         }
 165 }
 166
 167 static int search_vec(size_t *v, size_t *r, size_t key)
 168 {
 169         for (; v[0]!=key; v+=2)
 170                 if (!v[0]) return 0;
 171         *r = v[1];
 172         return 1;
 173 }
 174
 175 static uint32_t sysv_hash(const char *s0)
 176 {
 177         const unsigned char *s = (void *)s0;
 178         uint_fast32_t h = 0;
 179         while (*s) {
 180                 h = 16*h + *s++;
 181                 h ^= h>>24 & 0xf0;
 182         }
 183         return h & 0xfffffff;
 184 }
 185
 186 static uint32_t gnu_hash(const char *s0)
 187 {
 188         const unsigned char *s = (void *)s0;
 189         uint_fast32_t h = 5381;
 190         for (; *s; s++)
 191                 h += h*32 + *s;
 192         return h;
 193 }
 194
 195 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 196 {
 197         size_t i;
 198         Sym *syms = dso->syms;
 199         uint32_t *hashtab = dso->hashtab;
 200         char *strings = dso->strings;
 201         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 202                 if ((!dso->versym || dso->versym[i] >= 0)
 203                     && (!strcmp(s, strings+syms[i].st_name)))
 204                         return syms+i;
 205         }
 206         return 0;
 207 }
 208
 209 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
 210 {
 211         uint32_t nbuckets = hashtab[0];
 212         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 213         uint32_t i = buckets[h1 % nbuckets];
 214
 215         if (!i) return 0;
 216
 217         uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
 218
 219         for (h1 |= 1; ; i++) {
 220                 uint32_t h2 = *hashval++;
 221                 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
 222                     && !strcmp(s, dso->strings + dso->syms[i].st_name))
 223                         return dso->syms+i;
 224                 if (h2 & 1) break;
 225         }
 226
 227         return 0;
 228 }
 229
 230 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
 231 {
 232         const size_t *bloomwords = (const void *)(hashtab+4);
 233         size_t f = bloomwords[fofs & (hashtab[2]-1)];
 234         if (!(f & fmask)) return 0;
 235
 236         f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
 237         if (!(f & 1)) return 0;
 238
 239         return gnu_lookup(h1, hashtab, dso, s);
 240 }
 241
 242 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 243 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 244
 245 #ifndef ARCH_SYM_REJECT_UND
 246 #define ARCH_SYM_REJECT_UND(s) 0
 247 #endif
 248
 249 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 250 {
 251         uint32_t h = 0, gh, gho, *ght;
 252         size_t ghm = 0;
 253         struct symdef def = {0};
 254         for (; dso; dso=dso->next) {
 255                 Sym *sym;
 256                 if (!dso->global) continue;
 257                 if ((ght = dso->ghashtab)) {
 258                         if (!ghm) {
 259                                 gh = gnu_hash(s);
 260                                 int maskbits = 8 * sizeof ghm;
 261                                 gho = gh / maskbits;
 262                                 ghm = 1ul << gh % maskbits;
 263                         }
 264                         sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
 265                 } else {
 266                         if (!h) h = sysv_hash(s);
 267                         sym = sysv_lookup(s, h, dso);
 268                 }
 269                 if (!sym) continue;
 270                 if (!sym->st_shndx)
 271                         if (need_def || (sym->st_info&0xf) == STT_TLS
 272                             || ARCH_SYM_REJECT_UND(sym))
 273                                 continue;
 274                 if (!sym->st_value)
 275                         if ((sym->st_info&0xf) != STT_TLS)
 276                                 continue;
 277                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 278                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 279
 280                 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
 281                 def.sym = sym;
 282                 def.dso = dso;
 283                 if (sym->st_info>>4 == STB_GLOBAL) break;
 284         }
 285         return def;
 286 }
 287
 288 __attribute__((__visibility__("hidden")))
 289 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
 290
 291 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 292 {
 293         unsigned char *base = dso->base;
 294         Sym *syms = dso->syms;
 295         char *strings = dso->strings;
 296         Sym *sym;
 297         const char *name;
 298         void *ctx;
 299         int type;
 300         int sym_index;
 301         struct symdef def;
 302         size_t *reloc_addr;
 303         size_t sym_val;
 304         size_t tls_val;
 305         size_t addend;
 306         int skip_relative = 0, reuse_addends = 0, save_slot = 0;
 307
 308         if (dso == &ldso) {
 309                 /* Only ldso's REL table needs addend saving/reuse. */
 310                 if (rel == apply_addends_to)
 311                         reuse_addends = 1;
 312                 skip_relative = 1;
 313         }
 314
 315         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 316                 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
 317                 type = R_TYPE(rel[1]);
 318                 if (type == REL_NONE) continue;
 319                 sym_index = R_SYM(rel[1]);
 320                 reloc_addr = laddr(dso, rel[0]);
 321                 if (sym_index) {
 322                         sym = syms + sym_index;
 323                         name = strings + sym->st_name;
 324                         ctx = type==REL_COPY ? head->next : head;
 325                         def = (sym->st_info&0xf) == STT_SECTION
 326                                 ? (struct symdef){ .dso = dso, .sym = sym }
 327                                 : find_sym(ctx, name, type==REL_PLT);
 328                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 329                             || sym->st_info>>4 != STB_WEAK)) {
 330                                 error("Error relocating %s: %s: symbol not found",
 331                                         dso->name, name);
 332                                 if (runtime) longjmp(*rtld_fail, 1);
 333                                 continue;
 334                         }
 335                 } else {
 336                         sym = 0;
 337                         def.sym = 0;
 338                         def.dso = dso;
 339                 }
 340
 341                 if (stride > 2) {
 342                         addend = rel[2];
 343                 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
 344                         addend = 0;
 345                 } else if (reuse_addends) {
 346                         /* Save original addend in stage 2 where the dso
 347                          * chain consists of just ldso; otherwise read back
 348                          * saved addend since the inline one was clobbered. */
 349                         if (head==&ldso)
 350                                 saved_addends[save_slot] = *reloc_addr;
 351                         addend = saved_addends[save_slot++];
 352                 } else {
 353                         addend = *reloc_addr;
 354                 }
 355
 356                 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
 357                 tls_val = def.sym ? def.sym->st_value : 0;
 358
 359                 switch(type) {
 360                 case REL_NONE:
 361                         break;
 362                 case REL_OFFSET:
 363                         addend -= (size_t)reloc_addr;
 364                 case REL_SYMBOLIC:
 365                 case REL_GOT:
 366                 case REL_PLT:
 367                         *reloc_addr = sym_val + addend;
 368                         break;
 369                 case REL_RELATIVE:
 370                         *reloc_addr = (size_t)base + addend;
 371                         break;
 372                 case REL_SYM_OR_REL:
 373                         if (sym) *reloc_addr = sym_val + addend;
 374                         else *reloc_addr = (size_t)base + addend;
 375                         break;
 376                 case REL_COPY:
 377                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 378                         break;
 379                 case REL_OFFSET32:
 380                         *(uint32_t *)reloc_addr = sym_val + addend
 381                                 - (size_t)reloc_addr;
 382                         break;
 383                 case REL_FUNCDESC:
 384                         *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
 385                                 + (def.sym - def.dso->syms)) : 0;
 386                         break;
 387                 case REL_FUNCDESC_VAL:
 388                         if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
 389                         else *reloc_addr = sym_val;
 390                         reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
 391                         break;
 392                 case REL_DTPMOD:
 393                         *reloc_addr = def.dso->tls_id;
 394                         break;
 395                 case REL_DTPOFF:
 396                         *reloc_addr = tls_val + addend - DTP_OFFSET;
 397                         break;
 398 #ifdef TLS_ABOVE_TP
 399                 case REL_TPOFF:
 400                         *reloc_addr = tls_val + def.dso->tls_offset + TPOFF_K + addend;
 401                         break;
 402 #else
 403                 case REL_TPOFF:
 404                         *reloc_addr = tls_val - def.dso->tls_offset + addend;
 405                         break;
 406                 case REL_TPOFF_NEG:
 407                         *reloc_addr = def.dso->tls_offset - tls_val + addend;
 408                         break;
 409 #endif
 410                 case REL_TLSDESC:
 411                         if (stride<3) addend = reloc_addr[1];
 412                         if (runtime && def.dso->tls_id >= static_tls_cnt) {
 413                                 struct td_index *new = malloc(sizeof *new);
 414                                 if (!new) {
 415                                         error(
 416                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 417                                         dso->name, sym ? name : "(local)" );
 418                                         longjmp(*rtld_fail, 1);
 419                                 }
 420                                 new->next = dso->td_index;
 421                                 dso->td_index = new;
 422                                 new->args[0] = def.dso->tls_id;
 423                                 new->args[1] = tls_val + addend;
 424                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 425                                 reloc_addr[1] = (size_t)new;
 426                         } else {
 427                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 428 #ifdef TLS_ABOVE_TP
 429                                 reloc_addr[1] = tls_val + def.dso->tls_offset
 430                                         + TPOFF_K + addend;
 431 #else
 432                                 reloc_addr[1] = tls_val - def.dso->tls_offset
 433                                         + addend;
 434 #endif
 435                         }
 436                         break;
 437                 default:
 438                         error("Error relocating %s: unsupported relocation type %d",
 439                                 dso->name, type);
 440                         if (runtime) longjmp(*rtld_fail, 1);
 441                         continue;
 442                 }
 443         }
 444 }
 445
 446 /* A huge hack: to make up for the wastefulness of shared libraries
 447  * needing at least a page of dirty memory even if they have no global
 448  * data, we reclaim the gaps at the beginning and end of writable maps
 449  * and "donate" them to the heap by setting up minimal malloc
 450  * structures and then freeing them. */
 451
 452 static void reclaim(struct dso *dso, size_t start, size_t end)
 453 {
 454         size_t *a, *z;
 455         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 456         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 457         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 458         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 459         if (start>end || end-start < 4*sizeof(size_t)) return;
 460         a = laddr(dso, start);
 461         z = laddr(dso, end);
 462         a[-2] = 1;
 463         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 464         z[1] = 1;
 465         free(a);
 466 }
 467
 468 static void reclaim_gaps(struct dso *dso)
 469 {
 470         Phdr *ph = dso->phdr;
 471         size_t phcnt = dso->phnum;
 472
 473         if (DL_FDPIC) return; // FIXME
 474         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 475                 if (ph->p_type!=PT_LOAD) continue;
 476                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 477                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 478                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 479                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 480         }
 481 }
 482
 483 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
 484 {
 485         static int no_map_fixed;
 486         char *q;
 487         if (!no_map_fixed) {
 488                 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
 489                 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
 490                         return q;
 491                 no_map_fixed = 1;
 492         }
 493         /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
 494         if (flags & MAP_ANONYMOUS) {
 495                 memset(p, 0, n);
 496                 return p;
 497         }
 498         ssize_t r;
 499         if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
 500         for (q=p; n; q+=r, off+=r, n-=r) {
 501                 r = read(fd, q, n);
 502                 if (r < 0 && errno != EINTR) return MAP_FAILED;
 503                 if (!r) {
 504                         memset(q, 0, n);
 505                         break;
 506                 }
 507         }
 508         return p;
 509 }
 510
 511 static void unmap_library(struct dso *dso)
 512 {
 513         if (dso->loadmap) {
 514                 size_t i;
 515                 for (i=0; i<dso->loadmap->nsegs; i++) {
 516                         if (!dso->loadmap->segs[i].p_memsz)
 517                                 continue;
 518                         munmap((void *)dso->loadmap->segs[i].addr,
 519                                 dso->loadmap->segs[i].p_memsz);
 520                 }
 521                 free(dso->loadmap);
 522         } else if (dso->map && dso->map_len) {
 523                 munmap(dso->map, dso->map_len);
 524         }
 525 }
 526
 527 static void *map_library(int fd, struct dso *dso)
 528 {
 529         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 530         void *allocated_buf=0;
 531         size_t phsize;
 532         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 533         size_t this_min, this_max;
 534         size_t nsegs = 0;
 535         off_t off_start;
 536         Ehdr *eh;
 537         Phdr *ph, *ph0;
 538         unsigned prot;
 539         unsigned char *map=MAP_FAILED, *base;
 540         size_t dyn=0;
 541         size_t tls_image=0;
 542         size_t i;
 543
 544         ssize_t l = read(fd, buf, sizeof buf);
 545         eh = buf;
 546         if (l<0) return 0;
 547         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 548                 goto noexec;
 549         phsize = eh->e_phentsize * eh->e_phnum;
 550         if (phsize > sizeof buf - sizeof *eh) {
 551                 allocated_buf = malloc(phsize);
 552                 if (!allocated_buf) return 0;
 553                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 554                 if (l < 0) goto error;
 555                 if (l != phsize) goto noexec;
 556                 ph = ph0 = allocated_buf;
 557         } else if (eh->e_phoff + phsize > l) {
 558                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 559                 if (l < 0) goto error;
 560                 if (l != phsize) goto noexec;
 561                 ph = ph0 = (void *)(buf + 1);
 562         } else {
 563                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 564         }
 565         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 566                 if (ph->p_type == PT_DYNAMIC) {
 567                         dyn = ph->p_vaddr;
 568                 } else if (ph->p_type == PT_TLS) {
 569                         tls_image = ph->p_vaddr;
 570                         dso->tls_align = ph->p_align;
 571                         dso->tls_len = ph->p_filesz;
 572                         dso->tls_size = ph->p_memsz;
 573                 } else if (ph->p_type == PT_GNU_RELRO) {
 574                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 575                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 576                 }
 577                 if (ph->p_type != PT_LOAD) continue;
 578                 nsegs++;
 579                 if (ph->p_vaddr < addr_min) {
 580                         addr_min = ph->p_vaddr;
 581                         off_start = ph->p_offset;
 582                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 583                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 584                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 585                 }
 586                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 587                         addr_max = ph->p_vaddr+ph->p_memsz;
 588                 }
 589         }
 590         if (!dyn) goto noexec;
 591         if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
 592                 dso->loadmap = calloc(1, sizeof *dso->loadmap
 593                         + nsegs * sizeof *dso->loadmap->segs);
 594                 if (!dso->loadmap) goto error;
 595                 dso->loadmap->nsegs = nsegs;
 596                 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
 597                         if (ph->p_type != PT_LOAD) continue;
 598                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 599                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 600                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 601                         map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
 602                                 prot, (prot&PROT_WRITE) ? MAP_PRIVATE : MAP_SHARED,
 603                                 fd, ph->p_offset & -PAGE_SIZE);
 604                         if (map == MAP_FAILED) {
 605                                 unmap_library(dso);
 606                                 goto error;
 607                         }
 608                         dso->loadmap->segs[i].addr = (size_t)map +
 609                                 (ph->p_vaddr & PAGE_SIZE-1);
 610                         dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
 611                         dso->loadmap->segs[i].p_memsz = ph->p_memsz;
 612                         i++;
 613                         if (prot & PROT_WRITE) {
 614                                 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
 615                                         + ph->p_filesz;
 616                                 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
 617                                 size_t pgend = brk + ph->p_memsz - ph->p_filesz
 618                                         + PAGE_SIZE-1 & -PAGE_SIZE;
 619                                 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
 620                                         pgend-pgbrk, prot,
 621                                         MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
 622                                         -1, off_start) == MAP_FAILED)
 623                                         goto error;
 624                                 memset(map + brk, 0, pgbrk-brk);
 625                         }
 626                 }
 627                 map = (void *)dso->loadmap->segs[0].addr;
 628                 map_len = 0;
 629                 goto done_mapping;
 630         }
 631         addr_max += PAGE_SIZE-1;
 632         addr_max &= -PAGE_SIZE;
 633         addr_min &= -PAGE_SIZE;
 634         off_start &= -PAGE_SIZE;
 635         map_len = addr_max - addr_min + off_start;
 636         /* The first time, we map too much, possibly even more than
 637          * the length of the file. This is okay because we will not
 638          * use the invalid part; we just need to reserve the right
 639          * amount of virtual address space to map over later. */
 640         map = DL_NOMMU_SUPPORT
 641                 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
 642                         MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
 643                 : mmap((void *)addr_min, map_len, prot,
 644                         MAP_PRIVATE, fd, off_start);
 645         if (map==MAP_FAILED) goto error;
 646         dso->map = map;
 647         dso->map_len = map_len;
 648         /* If the loaded file is not relocatable and the requested address is
 649          * not available, then the load operation must fail. */
 650         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 651                 errno = EBUSY;
 652                 goto error;
 653         }
 654         base = map - addr_min;
 655         dso->phdr = 0;
 656         dso->phnum = 0;
 657         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 658                 if (ph->p_type != PT_LOAD) continue;
 659                 /* Check if the programs headers are in this load segment, and
 660                  * if so, record the address for use by dl_iterate_phdr. */
 661                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 662                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 663                         dso->phdr = (void *)(base + ph->p_vaddr
 664                                 + (eh->e_phoff-ph->p_offset));
 665                         dso->phnum = eh->e_phnum;
 666                         dso->phentsize = eh->e_phentsize;
 667                 }
 668                 /* Reuse the existing mapping for the lowest-address LOAD */
 669                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min && !DL_NOMMU_SUPPORT)
 670                         continue;
 671                 this_min = ph->p_vaddr & -PAGE_SIZE;
 672                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 673                 off_start = ph->p_offset & -PAGE_SIZE;
 674                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 675                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 676                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 677                 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 678                         goto error;
 679                 if (ph->p_memsz > ph->p_filesz) {
 680                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 681                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 682                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 683                         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)
 684                                 goto error;
 685                 }
 686         }
 687         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 688                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 689                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
 690                             && errno != ENOSYS)
 691                                 goto error;
 692                         break;
 693                 }
 694 done_mapping:
 695         dso->base = base;
 696         dso->dynv = laddr(dso, dyn);
 697         if (dso->tls_size) dso->tls_image = laddr(dso, tls_image);
 698         if (!runtime) reclaim_gaps(dso);
 699         free(allocated_buf);
 700         return map;
 701 noexec:
 702         errno = ENOEXEC;
 703 error:
 704         if (map!=MAP_FAILED) unmap_library(dso);
 705         free(allocated_buf);
 706         return 0;
 707 }
 708
 709 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 710 {
 711         size_t l;
 712         int fd;
 713         for (;;) {
 714                 s += strspn(s, ":\n");
 715                 l = strcspn(s, ":\n");
 716                 if (l-1 >= INT_MAX) return -1;
 717                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
 718                         if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 719                         switch (errno) {
 720                         case ENOENT:
 721                         case ENOTDIR:
 722                         case EACCES:
 723                         case ENAMETOOLONG:
 724                                 break;
 725                         default:
 726                                 /* Any negative value but -1 will inhibit
 727                                  * futher path search. */
 728                                 return -2;
 729                         }
 730                 }
 731                 s += l;
 732         }
 733 }
 734
 735 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 736 {
 737         size_t n, l;
 738         const char *s, *t, *origin;
 739         char *d;
 740         if (p->rpath || !p->rpath_orig) return 0;
 741         if (!strchr(p->rpath_orig, '$')) {
 742                 p->rpath = p->rpath_orig;
 743                 return 0;
 744         }
 745         n = 0;
 746         s = p->rpath_orig;
 747         while ((t=strchr(s, '$'))) {
 748                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 749                         return 0;
 750                 s = t+1;
 751                 n++;
 752         }
 753         if (n > SSIZE_MAX/PATH_MAX) return 0;
 754
 755         if (p->kernel_mapped) {
 756                 /* $ORIGIN searches cannot be performed for the main program
 757                  * when it is suid/sgid/AT_SECURE. This is because the
 758                  * pathname is under the control of the caller of execve.
 759                  * For libraries, however, $ORIGIN can be processed safely
 760                  * since the library's pathname came from a trusted source
 761                  * (either system paths or a call to dlopen). */
 762                 if (libc.secure)
 763                         return 0;
 764                 l = readlink("/proc/self/exe", buf, buf_size);
 765                 if (l == -1) switch (errno) {
 766                 case ENOENT:
 767                 case ENOTDIR:
 768                 case EACCES:
 769                         break;
 770                 default:
 771                         return -1;
 772                 }
 773                 if (l >= buf_size)
 774                         return 0;
 775                 buf[l] = 0;
 776                 origin = buf;
 777         } else {
 778                 origin = p->name;
 779         }
 780         t = strrchr(origin, '/');
 781         l = t ? t-origin : 0;
 782         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 783         if (!p->rpath) return -1;
 784
 785         d = p->rpath;
 786         s = p->rpath_orig;
 787         while ((t=strchr(s, '$'))) {
 788                 memcpy(d, s, t-s);
 789                 d += t-s;
 790                 memcpy(d, origin, l);
 791                 d += l;
 792                 /* It was determined previously that the '$' is followed
 793                  * either by "ORIGIN" or "{ORIGIN}". */
 794                 s = t + 7 + 2*(t[1]=='{');
 795         }
 796         strcpy(d, s);
 797         return 0;
 798 }
 799
 800 static void decode_dyn(struct dso *p)
 801 {
 802         size_t dyn[DYN_CNT];
 803         decode_vec(p->dynv, dyn, DYN_CNT);
 804         p->syms = laddr(p, dyn[DT_SYMTAB]);
 805         p->strings = laddr(p, dyn[DT_STRTAB]);
 806         if (dyn[0]&(1<<DT_HASH))
 807                 p->hashtab = laddr(p, dyn[DT_HASH]);
 808         if (dyn[0]&(1<<DT_RPATH))
 809                 p->rpath_orig = p->strings + dyn[DT_RPATH];
 810         if (dyn[0]&(1<<DT_RUNPATH))
 811                 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
 812         if (dyn[0]&(1<<DT_PLTGOT))
 813                 p->got = laddr(p, dyn[DT_PLTGOT]);
 814         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 815                 p->ghashtab = laddr(p, *dyn);
 816         if (search_vec(p->dynv, dyn, DT_VERSYM))
 817                 p->versym = laddr(p, *dyn);
 818 }
 819
 820 static size_t count_syms(struct dso *p)
 821 {
 822         if (p->hashtab) return p->hashtab[1];
 823
 824         size_t nsym, i;
 825         uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
 826         uint32_t *hashval;
 827         for (i = nsym = 0; i < p->ghashtab[0]; i++) {
 828                 if (buckets[i] > nsym)
 829                         nsym = buckets[i];
 830         }
 831         if (nsym) {
 832                 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
 833                 do nsym++;
 834                 while (!(*hashval++ & 1));
 835         }
 836         return nsym;
 837 }
 838
 839 static void *dl_mmap(size_t n)
 840 {
 841         void *p;
 842         int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
 843 #ifdef SYS_mmap2
 844         p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
 845 #else
 846         p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
 847 #endif
 848         return p == MAP_FAILED ? 0 : p;
 849 }
 850
 851 static void makefuncdescs(struct dso *p)
 852 {
 853         static int self_done;
 854         size_t nsym = count_syms(p);
 855         size_t i, size = nsym * sizeof(*p->funcdescs);
 856
 857         if (!self_done) {
 858                 p->funcdescs = dl_mmap(size);
 859                 self_done = 1;
 860         } else {
 861                 p->funcdescs = malloc(size);
 862         }
 863         if (!p->funcdescs) {
 864                 if (!runtime) a_crash();
 865                 error("Error allocating function descriptors for %s", p->name);
 866                 longjmp(*rtld_fail, 1);
 867         }
 868         for (i=0; i<nsym; i++) {
 869                 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
 870                         p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
 871                         p->funcdescs[i].got = p->got;
 872                 } else {
 873                         p->funcdescs[i].addr = 0;
 874                         p->funcdescs[i].got = 0;
 875                 }
 876         }
 877 }
 878
 879 static struct dso *load_library(const char *name, struct dso *needed_by)
 880 {
 881         char buf[2*NAME_MAX+2];
 882         const char *pathname;
 883         unsigned char *map;
 884         struct dso *p, temp_dso = {0};
 885         int fd;
 886         struct stat st;
 887         size_t alloc_size;
 888         int n_th = 0;
 889         int is_self = 0;
 890
 891         if (!*name) {
 892                 errno = EINVAL;
 893                 return 0;
 894         }
 895
 896         /* Catch and block attempts to reload the implementation itself */
 897         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 898                 static const char *rp, reserved[] =
 899                         "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
 900                 char *z = strchr(name, '.');
 901                 if (z) {
 902                         size_t l = z-name;
 903                         for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
 904                         if (*rp) {
 905                                 if (ldd_mode) {
 906                                         /* Track which names have been resolved
 907                                          * and only report each one once. */
 908                                         static unsigned reported;
 909                                         unsigned mask = 1U<<(rp-reserved);
 910                                         if (!(reported & mask)) {
 911                                                 reported |= mask;
 912                                                 dprintf(1, "\t%s => %s (%p)\n",
 913                                                         name, ldso.name,
 914                                                         ldso.base);
 915                                         }
 916                                 }
 917                                 is_self = 1;
 918                         }
 919                 }
 920         }
 921         if (!strcmp(name, ldso.name)) is_self = 1;
 922         if (is_self) {
 923                 if (!ldso.prev) {
 924                         tail->next = &ldso;
 925                         ldso.prev = tail;
 926                         tail = ldso.next ? ldso.next : &ldso;
 927                 }
 928                 return &ldso;
 929         }
 930         if (strchr(name, '/')) {
 931                 pathname = name;
 932                 fd = open(name, O_RDONLY|O_CLOEXEC);
 933         } else {
 934                 /* Search for the name to see if it's already loaded */
 935                 for (p=head->next; p; p=p->next) {
 936                         if (p->shortname && !strcmp(p->shortname, name)) {
 937                                 p->refcnt++;
 938                                 return p;
 939                         }
 940                 }
 941                 if (strlen(name) > NAME_MAX) return 0;
 942                 fd = -1;
 943                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 944                 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
 945                         if (fixup_rpath(p, buf, sizeof buf) < 0)
 946                                 fd = -2; /* Inhibit further search. */
 947                         if (p->rpath)
 948                                 fd = path_open(name, p->rpath, buf, sizeof buf);
 949                 }
 950                 if (fd == -1) {
 951                         if (!sys_path) {
 952                                 char *prefix = 0;
 953                                 size_t prefix_len;
 954                                 if (ldso.name[0]=='/') {
 955                                         char *s, *t, *z;
 956                                         for (s=t=z=ldso.name; *s; s++)
 957                                                 if (*s=='/') z=t, t=s;
 958                                         prefix_len = z-ldso.name;
 959                                         if (prefix_len < PATH_MAX)
 960                                                 prefix = ldso.name;
 961                                 }
 962                                 if (!prefix) {
 963                                         prefix = "";
 964                                         prefix_len = 0;
 965                                 }
 966                                 char etc_ldso_path[prefix_len + 1
 967                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
 968                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
 969                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 970                                         (int)prefix_len, prefix);
 971                                 FILE *f = fopen(etc_ldso_path, "rbe");
 972                                 if (f) {
 973                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
 974                                                 free(sys_path);
 975                                                 sys_path = "";
 976                                         }
 977                                         fclose(f);
 978                                 } else if (errno != ENOENT) {
 979                                         sys_path = "";
 980                                 }
 981                         }
 982                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
 983                         fd = path_open(name, sys_path, buf, sizeof buf);
 984                 }
 985                 pathname = buf;
 986         }
 987         if (fd < 0) return 0;
 988         if (fstat(fd, &st) < 0) {
 989                 close(fd);
 990                 return 0;
 991         }
 992         for (p=head->next; p; p=p->next) {
 993                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
 994                         /* If this library was previously loaded with a
 995                          * pathname but a search found the same inode,
 996                          * setup its shortname so it can be found by name. */
 997                         if (!p->shortname && pathname != name)
 998                                 p->shortname = strrchr(p->name, '/')+1;
 999                         close(fd);
1000                         p->refcnt++;
1001                         return p;
1002                 }
1003         }
1004         map = noload ? 0 : map_library(fd, &temp_dso);
1005         close(fd);
1006         if (!map) return 0;
1007
1008         /* Allocate storage for the new DSO. When there is TLS, this
1009          * storage must include a reservation for all pre-existing
1010          * threads to obtain copies of both the new TLS, and an
1011          * extended DTV capable of storing an additional slot for
1012          * the newly-loaded DSO. */
1013         alloc_size = sizeof *p + strlen(pathname) + 1;
1014         if (runtime && temp_dso.tls_image) {
1015                 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
1016                         + sizeof(void *) * (tls_cnt+3);
1017                 n_th = libc.threads_minus_1 + 1;
1018                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1019                 else alloc_size += n_th * per_th;
1020         }
1021         p = calloc(1, alloc_size);
1022         if (!p) {
1023                 unmap_library(&temp_dso);
1024                 return 0;
1025         }
1026         memcpy(p, &temp_dso, sizeof temp_dso);
1027         decode_dyn(p);
1028         p->dev = st.st_dev;
1029         p->ino = st.st_ino;
1030         p->refcnt = 1;
1031         p->needed_by = needed_by;
1032         p->name = p->buf;
1033         strcpy(p->name, pathname);
1034         /* Add a shortname only if name arg was not an explicit pathname. */
1035         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1036         if (p->tls_image) {
1037                 p->tls_id = ++tls_cnt;
1038                 tls_align = MAXP2(tls_align, p->tls_align);
1039 #ifdef TLS_ABOVE_TP
1040                 p->tls_offset = tls_offset + ( (tls_align-1) &
1041                         -(tls_offset + (uintptr_t)p->tls_image) );
1042                 tls_offset += p->tls_size;
1043 #else
1044                 tls_offset += p->tls_size + p->tls_align - 1;
1045                 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
1046                         & (p->tls_align-1);
1047                 p->tls_offset = tls_offset;
1048 #endif
1049                 p->new_dtv = (void *)(-sizeof(size_t) &
1050                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1051                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1052         }
1053
1054         tail->next = p;
1055         p->prev = tail;
1056         tail = p;
1057
1058         if (DL_FDPIC) makefuncdescs(p);
1059
1060         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1061
1062         return p;
1063 }
1064
1065 static void load_deps(struct dso *p)
1066 {
1067         size_t i, ndeps=0;
1068         struct dso ***deps = &p->deps, **tmp, *dep;
1069         for (; p; p=p->next) {
1070                 for (i=0; p->dynv[i]; i+=2) {
1071                         if (p->dynv[i] != DT_NEEDED) continue;
1072                         dep = load_library(p->strings + p->dynv[i+1], p);
1073                         if (!dep) {
1074                                 error("Error loading shared library %s: %m (needed by %s)",
1075                                         p->strings + p->dynv[i+1], p->name);
1076                                 if (runtime) longjmp(*rtld_fail, 1);
1077                                 continue;
1078                         }
1079                         if (runtime) {
1080                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
1081                                 if (!tmp) longjmp(*rtld_fail, 1);
1082                                 tmp[ndeps++] = dep;
1083                                 tmp[ndeps] = 0;
1084                                 *deps = tmp;
1085                         }
1086                 }
1087         }
1088 }
1089
1090 static void load_preload(char *s)
1091 {
1092         int tmp;
1093         char *z;
1094         for (z=s; *z; s=z) {
1095                 for (   ; *s && (isspace(*s) || *s==':'); s++);
1096                 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1097                 tmp = *z;
1098                 *z = 0;
1099                 load_library(s, 0);
1100                 *z = tmp;
1101         }
1102 }
1103
1104 static void make_global(struct dso *p)
1105 {
1106         for (; p; p=p->next) p->global = 1;
1107 }
1108
1109 static void do_mips_relocs(struct dso *p, size_t *got)
1110 {
1111         size_t i, j, rel[2];
1112         unsigned char *base = p->base;
1113         i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1114         if (p==&ldso) {
1115                 got += i;
1116         } else {
1117                 while (i--) *got++ += (size_t)base;
1118         }
1119         j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1120         i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1121         Sym *sym = p->syms + j;
1122         rel[0] = (unsigned char *)got - base;
1123         for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1124                 rel[1] = sym-p->syms << 8 | R_MIPS_JUMP_SLOT;
1125                 do_relocs(p, rel, sizeof rel, 2);
1126         }
1127 }
1128
1129 static void reloc_all(struct dso *p)
1130 {
1131         size_t dyn[DYN_CNT];
1132         for (; p; p=p->next) {
1133                 if (p->relocated) continue;
1134                 decode_vec(p->dynv, dyn, DYN_CNT);
1135                 if (NEED_MIPS_GOT_RELOCS)
1136                         do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1137                 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1138                         2+(dyn[DT_PLTREL]==DT_RELA));
1139                 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1140                 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1141
1142                 if (head != &ldso && p->relro_start != p->relro_end &&
1143                     mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1144                     && errno != ENOSYS) {
1145                         error("Error relocating %s: RELRO protection failed: %m",
1146                                 p->name);
1147                         if (runtime) longjmp(*rtld_fail, 1);
1148                 }
1149
1150                 p->relocated = 1;
1151         }
1152 }
1153
1154 static void kernel_mapped_dso(struct dso *p)
1155 {
1156         size_t min_addr = -1, max_addr = 0, cnt;
1157         Phdr *ph = p->phdr;
1158         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1159                 if (ph->p_type == PT_DYNAMIC) {
1160                         p->dynv = laddr(p, ph->p_vaddr);
1161                 } else if (ph->p_type == PT_GNU_RELRO) {
1162                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1163                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1164                 }
1165                 if (ph->p_type != PT_LOAD) continue;
1166                 if (ph->p_vaddr < min_addr)
1167                         min_addr = ph->p_vaddr;
1168                 if (ph->p_vaddr+ph->p_memsz > max_addr)
1169                         max_addr = ph->p_vaddr+ph->p_memsz;
1170         }
1171         min_addr &= -PAGE_SIZE;
1172         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1173         p->map = p->base + min_addr;
1174         p->map_len = max_addr - min_addr;
1175         p->kernel_mapped = 1;
1176 }
1177
1178 void __libc_exit_fini()
1179 {
1180         struct dso *p;
1181         size_t dyn[DYN_CNT];
1182         for (p=fini_head; p; p=p->fini_next) {
1183                 if (!p->constructed) continue;
1184                 decode_vec(p->dynv, dyn, DYN_CNT);
1185                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1186                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1187                         size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1188                         while (n--) ((void (*)(void))*--fn)();
1189                 }
1190 #ifndef NO_LEGACY_INITFINI
1191                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1192                         fpaddr(p, dyn[DT_FINI])();
1193 #endif
1194         }
1195 }
1196
1197 static void do_init_fini(struct dso *p)
1198 {
1199         size_t dyn[DYN_CNT];
1200         int need_locking = libc.threads_minus_1;
1201         /* Allow recursive calls that arise when a library calls
1202          * dlopen from one of its constructors, but block any
1203          * other threads until all ctors have finished. */
1204         if (need_locking) pthread_mutex_lock(&init_fini_lock);
1205         for (; p; p=p->prev) {
1206                 if (p->constructed) continue;
1207                 p->constructed = 1;
1208                 decode_vec(p->dynv, dyn, DYN_CNT);
1209                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1210                         p->fini_next = fini_head;
1211                         fini_head = p;
1212                 }
1213 #ifndef NO_LEGACY_INITFINI
1214                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1215                         fpaddr(p, dyn[DT_INIT])();
1216 #endif
1217                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1218                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1219                         size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1220                         while (n--) ((void (*)(void))*fn++)();
1221                 }
1222                 if (!need_locking && libc.threads_minus_1) {
1223                         need_locking = 1;
1224                         pthread_mutex_lock(&init_fini_lock);
1225                 }
1226         }
1227         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1228 }
1229
1230 void __libc_start_init(void)
1231 {
1232         do_init_fini(tail);
1233 }
1234
1235 static void dl_debug_state(void)
1236 {
1237 }
1238
1239 weak_alias(dl_debug_state, _dl_debug_state);
1240
1241 void __reset_tls()
1242 {
1243         pthread_t self = __pthread_self();
1244         struct dso *p;
1245         for (p=head; p; p=p->next) {
1246                 if (!p->tls_id || !self->dtv[p->tls_id]) continue;
1247                 memcpy(self->dtv[p->tls_id], p->tls_image, p->tls_len);
1248                 memset((char *)self->dtv[p->tls_id]+p->tls_len, 0,
1249                         p->tls_size - p->tls_len);
1250                 if (p->tls_id == (size_t)self->dtv[0]) break;
1251         }
1252 }
1253
1254 void *__copy_tls(unsigned char *mem)
1255 {
1256         pthread_t td;
1257         struct dso *p;
1258         void **dtv;
1259
1260 #ifdef TLS_ABOVE_TP
1261         dtv = (void **)(mem + libc.tls_size) - (tls_cnt + 1);
1262
1263         mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
1264         td = (pthread_t)mem;
1265         mem += sizeof(struct pthread);
1266
1267         for (p=head; p; p=p->next) {
1268                 if (!p->tls_id) continue;
1269                 dtv[p->tls_id] = mem + p->tls_offset;
1270                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1271         }
1272 #else
1273         dtv = (void **)mem;
1274
1275         mem += libc.tls_size - sizeof(struct pthread);
1276         mem -= (uintptr_t)mem & (tls_align-1);
1277         td = (pthread_t)mem;
1278
1279         for (p=head; p; p=p->next) {
1280                 if (!p->tls_id) continue;
1281                 dtv[p->tls_id] = mem - p->tls_offset;
1282                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
1283         }
1284 #endif
1285         dtv[0] = (void *)tls_cnt;
1286         td->dtv = td->dtv_copy = dtv;
1287         return td;
1288 }
1289
1290 __attribute__((__visibility__("hidden")))
1291 void *__tls_get_new(size_t *v)
1292 {
1293         pthread_t self = __pthread_self();
1294
1295         /* Block signals to make accessing new TLS async-signal-safe */
1296         sigset_t set;
1297         __block_all_sigs(&set);
1298         if (v[0]<=(size_t)self->dtv[0]) {
1299                 __restore_sigs(&set);
1300                 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1301         }
1302
1303         /* This is safe without any locks held because, if the caller
1304          * is able to request the Nth entry of the DTV, the DSO list
1305          * must be valid at least that far out and it was synchronized
1306          * at program startup or by an already-completed call to dlopen. */
1307         struct dso *p;
1308         for (p=head; p->tls_id != v[0]; p=p->next);
1309
1310         /* Get new DTV space from new DSO if needed */
1311         if (v[0] > (size_t)self->dtv[0]) {
1312                 void **newdtv = p->new_dtv +
1313                         (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
1314                 memcpy(newdtv, self->dtv,
1315                         ((size_t)self->dtv[0]+1) * sizeof(void *));
1316                 newdtv[0] = (void *)v[0];
1317                 self->dtv = self->dtv_copy = newdtv;
1318         }
1319
1320         /* Get new TLS memory from all new DSOs up to the requested one */
1321         unsigned char *mem;
1322         for (p=head; ; p=p->next) {
1323                 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1324                 mem = p->new_tls + (p->tls_size + p->tls_align)
1325                         * a_fetch_add(&p->new_tls_idx,1);
1326                 mem += ((uintptr_t)p->tls_image - (uintptr_t)mem)
1327                         & (p->tls_align-1);
1328                 self->dtv[p->tls_id] = mem;
1329                 memcpy(mem, p->tls_image, p->tls_len);
1330                 if (p->tls_id == v[0]) break;
1331         }
1332         __restore_sigs(&set);
1333         return mem + v[1] + DTP_OFFSET;
1334 }
1335
1336 static void update_tls_size()
1337 {
1338         libc.tls_size = ALIGN(
1339                 (1+tls_cnt) * sizeof(void *) +
1340                 tls_offset +
1341                 sizeof(struct pthread) +
1342                 tls_align * 2,
1343         tls_align);
1344 }
1345
1346 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1347  * following stage 2 and stage 3 functions via primitive symbolic lookup
1348  * since it does not have access to their addresses to begin with. */
1349
1350 /* Stage 2 of the dynamic linker is called after relative relocations
1351  * have been processed. It can make function calls to static functions
1352  * and access string literals and static data, but cannot use extern
1353  * symbols. Its job is to perform symbolic relocations on the dynamic
1354  * linker itself, but some of the relocations performed may need to be
1355  * replaced later due to copy relocations in the main program. */
1356
1357 __attribute__((__visibility__("hidden")))
1358 void __dls2(unsigned char *base, size_t *sp)
1359 {
1360         if (DL_FDPIC) {
1361                 void *p1 = (void *)sp[-2];
1362                 void *p2 = (void *)sp[-1];
1363                 if (!p1) {
1364                         size_t *auxv, aux[AUX_CNT];
1365                         for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
1366                         decode_vec(auxv, aux, AUX_CNT);
1367                         if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1368                         else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1369                 }
1370                 app_loadmap = p2 ? p1 : 0;
1371                 ldso.loadmap = p2 ? p2 : p1;
1372                 ldso.base = laddr(&ldso, 0);
1373         } else {
1374                 ldso.base = base;
1375         }
1376         Ehdr *ehdr = (void *)ldso.base;
1377         ldso.name = ldso.shortname = "libc.so";
1378         ldso.global = 1;
1379         ldso.phnum = ehdr->e_phnum;
1380         ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1381         ldso.phentsize = ehdr->e_phentsize;
1382         kernel_mapped_dso(&ldso);
1383         decode_dyn(&ldso);
1384
1385         if (DL_FDPIC) makefuncdescs(&ldso);
1386
1387         /* Prepare storage for to save clobbered REL addends so they
1388          * can be reused in stage 3. There should be very few. If
1389          * something goes wrong and there are a huge number, abort
1390          * instead of risking stack overflow. */
1391         size_t dyn[DYN_CNT];
1392         decode_vec(ldso.dynv, dyn, DYN_CNT);
1393         size_t *rel = laddr(&ldso, dyn[DT_REL]);
1394         size_t rel_size = dyn[DT_RELSZ];
1395         size_t symbolic_rel_cnt = 0;
1396         apply_addends_to = rel;
1397         for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1398                 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1399         if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1400         size_t addends[symbolic_rel_cnt+1];
1401         saved_addends = addends;
1402
1403         head = &ldso;
1404         reloc_all(&ldso);
1405
1406         ldso.relocated = 0;
1407
1408         /* Call dynamic linker stage-3, __dls3, looking it up
1409          * symbolically as a barrier against moving the address
1410          * load across the above relocation processing. */
1411         struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1412         if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1413         else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1414 }
1415
1416 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1417  * fully functional. Its job is to load (if not already loaded) and
1418  * process dependencies and relocations for the main application and
1419  * transfer control to its entry point. */
1420
1421 _Noreturn void __dls3(size_t *sp)
1422 {
1423         static struct dso app, vdso;
1424         size_t aux[AUX_CNT], *auxv;
1425         size_t i;
1426         char *env_preload=0;
1427         size_t vdso_base;
1428         int argc = *sp;
1429         char **argv = (void *)(sp+1);
1430         char **argv_orig = argv;
1431         char **envp = argv+argc+1;
1432
1433         /* Find aux vector just past environ[] and use it to initialize
1434          * global data that may be needed before we can make syscalls. */
1435         __environ = envp;
1436         for (i=argc+1; argv[i]; i++);
1437         libc.auxv = auxv = (void *)(argv+i+1);
1438         decode_vec(auxv, aux, AUX_CNT);
1439         __hwcap = aux[AT_HWCAP];
1440         libc.page_size = aux[AT_PAGESZ];
1441         libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1442                 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1443
1444         /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1445          * use during dynamic linking. If possible it will also serve as the
1446          * thread pointer at runtime. */
1447         libc.tls_size = sizeof builtin_tls;
1448         if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1449                 a_crash();
1450         }
1451
1452         /* Only trust user/env if kernel says we're not suid/sgid */
1453         if (!libc.secure) {
1454                 env_path = getenv("LD_LIBRARY_PATH");
1455                 env_preload = getenv("LD_PRELOAD");
1456         }
1457
1458         /* If the main program was already loaded by the kernel,
1459          * AT_PHDR will point to some location other than the dynamic
1460          * linker's program headers. */
1461         if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1462                 size_t interp_off = 0;
1463                 size_t tls_image = 0;
1464                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1465                 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1466                 app.phnum = aux[AT_PHNUM];
1467                 app.phentsize = aux[AT_PHENT];
1468                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1469                         if (phdr->p_type == PT_PHDR)
1470                                 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1471                         else if (phdr->p_type == PT_INTERP)
1472                                 interp_off = (size_t)phdr->p_vaddr;
1473                         else if (phdr->p_type == PT_TLS) {
1474                                 tls_image = phdr->p_vaddr;
1475                                 app.tls_len = phdr->p_filesz;
1476                                 app.tls_size = phdr->p_memsz;
1477                                 app.tls_align = phdr->p_align;
1478                         }
1479                 }
1480                 if (DL_FDPIC) app.loadmap = app_loadmap;
1481                 if (app.tls_size) app.tls_image = laddr(&app, tls_image);
1482                 if (interp_off) ldso.name = laddr(&app, interp_off);
1483                 if ((aux[0] & (1UL<<AT_EXECFN))
1484                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1485                         app.name = (char *)aux[AT_EXECFN];
1486                 else
1487                         app.name = argv[0];
1488                 kernel_mapped_dso(&app);
1489         } else {
1490                 int fd;
1491                 char *ldname = argv[0];
1492                 size_t l = strlen(ldname);
1493                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1494                 argv++;
1495                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1496                         char *opt = argv[0]+2;
1497                         *argv++ = (void *)-1;
1498                         if (!*opt) {
1499                                 break;
1500                         } else if (!memcmp(opt, "list", 5)) {
1501                                 ldd_mode = 1;
1502                         } else if (!memcmp(opt, "library-path", 12)) {
1503                                 if (opt[12]=='=') env_path = opt+13;
1504                                 else if (opt[12]) *argv = 0;
1505                                 else if (*argv) env_path = *argv++;
1506                         } else if (!memcmp(opt, "preload", 7)) {
1507                                 if (opt[7]=='=') env_preload = opt+8;
1508                                 else if (opt[7]) *argv = 0;
1509                                 else if (*argv) env_preload = *argv++;
1510                         } else {
1511                                 argv[0] = 0;
1512                         }
1513                 }
1514                 argv[-1] = (void *)(argc - (argv-argv_orig));
1515                 if (!argv[0]) {
1516                         dprintf(2, "musl libc\n"
1517                                 "Version %s\n"
1518                                 "Dynamic Program Loader\n"
1519                                 "Usage: %s [options] [--] pathname%s\n",
1520                                 __libc_get_version(), ldname,
1521                                 ldd_mode ? "" : " [args]");
1522                         _exit(1);
1523                 }
1524                 fd = open(argv[0], O_RDONLY);
1525                 if (fd < 0) {
1526                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1527                         _exit(1);
1528                 }
1529                 runtime = 1;
1530                 Ehdr *ehdr = (void *)map_library(fd, &app);
1531                 if (!ehdr) {
1532                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1533                         _exit(1);
1534                 }
1535                 runtime = 0;
1536                 close(fd);
1537                 ldso.name = ldname;
1538                 app.name = argv[0];
1539                 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1540                 /* Find the name that would have been used for the dynamic
1541                  * linker had ldd not taken its place. */
1542                 if (ldd_mode) {
1543                         for (i=0; i<app.phnum; i++) {
1544                                 if (app.phdr[i].p_type == PT_INTERP)
1545                                         ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1546                         }
1547                         dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1548                 }
1549         }
1550         if (app.tls_size) {
1551                 app.tls_id = tls_cnt = 1;
1552 #ifdef TLS_ABOVE_TP
1553                 app.tls_offset = 0;
1554                 tls_offset = app.tls_size
1555                         + ( -((uintptr_t)app.tls_image + app.tls_size)
1556                         & (app.tls_align-1) );
1557 #else
1558                 tls_offset = app.tls_offset = app.tls_size
1559                         + ( -((uintptr_t)app.tls_image + app.tls_size)
1560                         & (app.tls_align-1) );
1561 #endif
1562                 tls_align = MAXP2(tls_align, app.tls_align);
1563         }
1564         app.global = 1;
1565         decode_dyn(&app);
1566         if (DL_FDPIC) {
1567                 makefuncdescs(&app);
1568                 if (!app.loadmap) {
1569                         app.loadmap = (void *)&app_dummy_loadmap;
1570                         app.loadmap->nsegs = 1;
1571                         app.loadmap->segs[0].addr = (size_t)app.map;
1572                         app.loadmap->segs[0].p_vaddr = (size_t)app.map
1573                                 - (size_t)app.base;
1574                         app.loadmap->segs[0].p_memsz = app.map_len;
1575                 }
1576                 argv[-3] = (void *)app.loadmap;
1577         }
1578
1579         /* Attach to vdso, if provided by the kernel */
1580         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1581                 Ehdr *ehdr = (void *)vdso_base;
1582                 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1583                 vdso.phnum = ehdr->e_phnum;
1584                 vdso.phentsize = ehdr->e_phentsize;
1585                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1586                         if (phdr->p_type == PT_DYNAMIC)
1587                                 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1588                         if (phdr->p_type == PT_LOAD)
1589                                 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1590                 }
1591                 vdso.name = "";
1592                 vdso.shortname = "linux-gate.so.1";
1593                 vdso.global = 1;
1594                 vdso.relocated = 1;
1595                 decode_dyn(&vdso);
1596                 vdso.prev = &ldso;
1597                 ldso.next = &vdso;
1598         }
1599
1600         /* Initial dso chain consists only of the app. */
1601         head = tail = &app;
1602
1603         /* Donate unused parts of app and library mapping to malloc */
1604         reclaim_gaps(&app);
1605         reclaim_gaps(&ldso);
1606
1607         /* Load preload/needed libraries, add their symbols to the global
1608          * namespace, and perform all remaining relocations. */
1609         if (env_preload) load_preload(env_preload);
1610         load_deps(&app);
1611         make_global(&app);
1612
1613 #ifndef DYNAMIC_IS_RO
1614         for (i=0; app.dynv[i]; i+=2)
1615                 if (app.dynv[i]==DT_DEBUG)
1616                         app.dynv[i+1] = (size_t)&debug;
1617 #endif
1618
1619         /* The main program must be relocated LAST since it may contin
1620          * copy relocations which depend on libraries' relocations. */
1621         reloc_all(app.next);
1622         reloc_all(&app);
1623
1624         update_tls_size();
1625         if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1626                 void *initial_tls = calloc(libc.tls_size, 1);
1627                 if (!initial_tls) {
1628                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1629                                 argv[0], libc.tls_size);
1630                         _exit(127);
1631                 }
1632                 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1633                         a_crash();
1634                 }
1635         } else {
1636                 size_t tmp_tls_size = libc.tls_size;
1637                 pthread_t self = __pthread_self();
1638                 /* Temporarily set the tls size to the full size of
1639                  * builtin_tls so that __copy_tls will use the same layout
1640                  * as it did for before. Then check, just to be safe. */
1641                 libc.tls_size = sizeof builtin_tls;
1642                 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1643                 libc.tls_size = tmp_tls_size;
1644         }
1645         static_tls_cnt = tls_cnt;
1646
1647         if (ldso_fail) _exit(127);
1648         if (ldd_mode) _exit(0);
1649
1650         /* Switch to runtime mode: any further failures in the dynamic
1651          * linker are a reportable failure rather than a fatal startup
1652          * error. */
1653         runtime = 1;
1654
1655         debug.ver = 1;
1656         debug.bp = dl_debug_state;
1657         debug.head = head;
1658         debug.base = ldso.base;
1659         debug.state = 0;
1660         _dl_debug_state();
1661
1662         errno = 0;
1663
1664         CRTJMP((void *)aux[AT_ENTRY], argv-1);
1665         for(;;);
1666 }
1667
1668 void *dlopen(const char *file, int mode)
1669 {
1670         struct dso *volatile p, *orig_tail, *next;
1671         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1672         size_t i;
1673         int cs;
1674         jmp_buf jb;
1675
1676         if (!file) return head;
1677
1678         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1679         pthread_rwlock_wrlock(&lock);
1680         __inhibit_ptc();
1681
1682         p = 0;
1683         orig_tls_cnt = tls_cnt;
1684         orig_tls_offset = tls_offset;
1685         orig_tls_align = tls_align;
1686         orig_tail = tail;
1687         noload = mode & RTLD_NOLOAD;
1688
1689         rtld_fail = &jb;
1690         if (setjmp(*rtld_fail)) {
1691                 /* Clean up anything new that was (partially) loaded */
1692                 if (p && p->deps) for (i=0; p->deps[i]; i++)
1693                         if (p->deps[i]->global < 0)
1694                                 p->deps[i]->global = 0;
1695                 for (p=orig_tail->next; p; p=next) {
1696                         next = p->next;
1697                         while (p->td_index) {
1698                                 void *tmp = p->td_index->next;
1699                                 free(p->td_index);
1700                                 p->td_index = tmp;
1701                         }
1702                         free(p->funcdescs);
1703                         if (p->rpath != p->rpath_orig)
1704                                 free(p->rpath);
1705                         free(p->deps);
1706                         unmap_library(p);
1707                         free(p);
1708                 }
1709                 tls_cnt = orig_tls_cnt;
1710                 tls_offset = orig_tls_offset;
1711                 tls_align = orig_tls_align;
1712                 tail = orig_tail;
1713                 tail->next = 0;
1714                 p = 0;
1715                 goto end;
1716         } else p = load_library(file, head);
1717
1718         if (!p) {
1719                 error(noload ?
1720                         "Library %s is not already loaded" :
1721                         "Error loading shared library %s: %m",
1722                         file);
1723                 goto end;
1724         }
1725
1726         /* First load handling */
1727         if (!p->deps) {
1728                 load_deps(p);
1729                 if (p->deps) for (i=0; p->deps[i]; i++)
1730                         if (!p->deps[i]->global)
1731                                 p->deps[i]->global = -1;
1732                 if (!p->global) p->global = -1;
1733                 reloc_all(p);
1734                 if (p->deps) for (i=0; p->deps[i]; i++)
1735                         if (p->deps[i]->global < 0)
1736                                 p->deps[i]->global = 0;
1737                 if (p->global < 0) p->global = 0;
1738         }
1739
1740         if (mode & RTLD_GLOBAL) {
1741                 if (p->deps) for (i=0; p->deps[i]; i++)
1742                         p->deps[i]->global = 1;
1743                 p->global = 1;
1744         }
1745
1746         update_tls_size();
1747         _dl_debug_state();
1748         orig_tail = tail;
1749 end:
1750         __release_ptc();
1751         if (p) gencnt++;
1752         pthread_rwlock_unlock(&lock);
1753         if (p) do_init_fini(orig_tail);
1754         pthread_setcancelstate(cs, 0);
1755         return p;
1756 }
1757
1758 static int invalid_dso_handle(void *h)
1759 {
1760         struct dso *p;
1761         for (p=head; p; p=p->next) if (h==p) return 0;
1762         error("Invalid library handle %p", (void *)h);
1763         return 1;
1764 }
1765
1766 static void *addr2dso(size_t a)
1767 {
1768         struct dso *p;
1769         size_t i;
1770         if (DL_FDPIC) for (p=head; p; p=p->next) {
1771                 i = count_syms(p);
1772                 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
1773                         return p;
1774         }
1775         for (p=head; p; p=p->next) {
1776                 if (DL_FDPIC && p->loadmap) {
1777                         for (i=0; i<p->loadmap->nsegs; i++) {
1778                                 if (a-p->loadmap->segs[i].p_vaddr
1779                                     < p->loadmap->segs[i].p_memsz)
1780                                         return p;
1781                         }
1782                 } else {
1783                         if (a-(size_t)p->map < p->map_len)
1784                                 return p;
1785                 }
1786         }
1787         return 0;
1788 }
1789
1790 void *__tls_get_addr(size_t *);
1791
1792 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1793 {
1794         size_t i;
1795         uint32_t h = 0, gh = 0, *ght;
1796         Sym *sym;
1797         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1798                 if (p == RTLD_DEFAULT) {
1799                         p = head;
1800                 } else if (p == RTLD_NEXT) {
1801                         p = addr2dso((size_t)ra);
1802                         if (!p) p=head;
1803                         p = p->next;
1804                 }
1805                 struct symdef def = find_sym(p, s, 0);
1806                 if (!def.sym) goto failed;
1807                 if ((def.sym->st_info&0xf) == STT_TLS)
1808                         return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1809                 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
1810                         return def.dso->funcdescs + (def.sym - def.dso->syms);
1811                 return laddr(def.dso, def.sym->st_value);
1812         }
1813         if (invalid_dso_handle(p))
1814                 return 0;
1815         if ((ght = p->ghashtab)) {
1816                 gh = gnu_hash(s);
1817                 sym = gnu_lookup(gh, ght, p, s);
1818         } else {
1819                 h = sysv_hash(s);
1820                 sym = sysv_lookup(s, h, p);
1821         }
1822         if (sym && (sym->st_info&0xf) == STT_TLS)
1823                 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1824         if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1825                 return p->funcdescs + (sym - p->syms);
1826         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1827                 return laddr(p, sym->st_value);
1828         if (p->deps) for (i=0; p->deps[i]; i++) {
1829                 if ((ght = p->deps[i]->ghashtab)) {
1830                         if (!gh) gh = gnu_hash(s);
1831                         sym = gnu_lookup(gh, ght, p->deps[i], s);
1832                 } else {
1833                         if (!h) h = sysv_hash(s);
1834                         sym = sysv_lookup(s, h, p->deps[i]);
1835                 }
1836                 if (sym && (sym->st_info&0xf) == STT_TLS)
1837                         return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1838                 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1839                         return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
1840                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1841                         return laddr(p->deps[i], sym->st_value);
1842         }
1843 failed:
1844         error("Symbol not found: %s", s);
1845         return 0;
1846 }
1847
1848 int __dladdr(const void *addr, Dl_info *info)
1849 {
1850         struct dso *p;
1851         Sym *sym, *bestsym;
1852         uint32_t nsym;
1853         char *strings;
1854         void *best = 0;
1855
1856         pthread_rwlock_rdlock(&lock);
1857         p = addr2dso((size_t)addr);
1858         pthread_rwlock_unlock(&lock);
1859
1860         if (!p) return 0;
1861
1862         sym = p->syms;
1863         strings = p->strings;
1864         nsym = count_syms(p);
1865
1866         if (DL_FDPIC) {
1867                 size_t idx = ((size_t)addr-(size_t)p->funcdescs)
1868                         / sizeof(*p->funcdescs);
1869                 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
1870                         best = p->funcdescs + idx;
1871                         bestsym = sym + idx;
1872                 }
1873         }
1874
1875         if (!best) for (; nsym; nsym--, sym++) {
1876                 if (sym->st_value
1877                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1878                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1879                         void *symaddr = laddr(p, sym->st_value);
1880                         if (symaddr > addr || symaddr < best)
1881                                 continue;
1882                         best = symaddr;
1883                         bestsym = sym;
1884                         if (addr == symaddr)
1885                                 break;
1886                 }
1887         }
1888
1889         if (!best) return 0;
1890
1891         if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
1892                 best = p->funcdescs + (bestsym - p->syms);
1893
1894         info->dli_fname = p->name;
1895         info->dli_fbase = p->base;
1896         info->dli_sname = strings + bestsym->st_name;
1897         info->dli_saddr = best;
1898
1899         return 1;
1900 }
1901
1902 __attribute__((__visibility__("hidden")))
1903 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1904 {
1905         void *res;
1906         pthread_rwlock_rdlock(&lock);
1907         res = do_dlsym(p, s, ra);
1908         pthread_rwlock_unlock(&lock);
1909         return res;
1910 }
1911
1912 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1913 {
1914         struct dso *current;
1915         struct dl_phdr_info info;
1916         int ret = 0;
1917         for(current = head; current;) {
1918                 info.dlpi_addr      = (uintptr_t)current->base;
1919                 info.dlpi_name      = current->name;
1920                 info.dlpi_phdr      = current->phdr;
1921                 info.dlpi_phnum     = current->phnum;
1922                 info.dlpi_adds      = gencnt;
1923                 info.dlpi_subs      = 0;
1924                 info.dlpi_tls_modid = current->tls_id;
1925                 info.dlpi_tls_data  = current->tls_image;
1926
1927                 ret = (callback)(&info, sizeof (info), data);
1928
1929                 if (ret != 0) break;
1930
1931                 pthread_rwlock_rdlock(&lock);
1932                 current = current->next;
1933                 pthread_rwlock_unlock(&lock);
1934         }
1935         return ret;
1936 }
1937 #else
1938 static int invalid_dso_handle(void *h)
1939 {
1940         error("Invalid library handle %p", (void *)h);
1941         return 1;
1942 }
1943 void *dlopen(const char *file, int mode)
1944 {
1945         error("Dynamic loading not supported");
1946         return 0;
1947 }
1948 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1949 {
1950         error("Symbol not found: %s", s);
1951         return 0;
1952 }
1953 int __dladdr (const void *addr, Dl_info *info)
1954 {
1955         return 0;
1956 }
1957 #endif
1958
1959 int __dlinfo(void *dso, int req, void *res)
1960 {
1961         if (invalid_dso_handle(dso)) return -1;
1962         if (req != RTLD_DI_LINKMAP) {
1963                 error("Unsupported request %d", req);
1964                 return -1;
1965         }
1966         *(struct link_map **)res = dso;
1967         return 0;
1968 }
1969
1970 char *dlerror()
1971 {
1972         pthread_t self = __pthread_self();
1973         if (!self->dlerror_flag) return 0;
1974         self->dlerror_flag = 0;
1975         char *s = self->dlerror_buf;
1976         if (s == (void *)-1)
1977                 return "Dynamic linker failed to allocate memory for error message";
1978         else
1979                 return s;
1980 }
1981
1982 int dlclose(void *p)
1983 {
1984         return invalid_dso_handle(p);
1985 }
1986
1987 void __dl_thread_cleanup(void)
1988 {
1989         pthread_t self = __pthread_self();
1990         if (self->dlerror_buf != (void *)-1)
1991                 free(self->dlerror_buf);
1992 }
1993
1994 static void error(const char *fmt, ...)
1995 {
1996         va_list ap;
1997         va_start(ap, fmt);
1998 #ifdef SHARED
1999         if (!runtime) {
2000                 vdprintf(2, fmt, ap);
2001                 dprintf(2, "\n");
2002                 ldso_fail = 1;
2003                 va_end(ap);
2004                 return;
2005         }
2006 #endif
2007         pthread_t self = __pthread_self();
2008         if (self->dlerror_buf != (void *)-1)
2009                 free(self->dlerror_buf);
2010         size_t len = vsnprintf(0, 0, fmt, ap);
2011         va_end(ap);
2012         char *buf = malloc(len+1);
2013         if (buf) {
2014                 va_start(ap, fmt);
2015                 vsnprintf(buf, len+1, fmt, ap);
2016                 va_end(ap);
2017         } else {
2018                 buf = (void *)-1;
2019         }
2020         self->dlerror_buf = buf;
2021         self->dlerror_flag = 1;
2022 }