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