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