nsz Git - musl/blob - ldso/dynlink.c

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <stdarg.h>
   5 #include <stddef.h>
   6 #include <string.h>
   7 #include <unistd.h>
   8 #include <stdint.h>
   9 #include <elf.h>
  10 #include <sys/mman.h>
  11 #include <limits.h>
  12 #include <fcntl.h>
  13 #include <sys/stat.h>
  14 #include <errno.h>
  15 #include <link.h>
  16 #include <setjmp.h>
  17 #include <pthread.h>
  18 #include <ctype.h>
  19 #include <dlfcn.h>
  20 #include "pthread_impl.h"
  21 #include "libc.h"
  22 #include "dynlink.h"
  23
  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         Sym *syms;
  56         Elf_Symndx *hashtab;
  57         uint32_t *ghashtab;
  58         int16_t *versym;
  59         char *strings;
  60         struct dso *syms_next, *lazy_next;
  61         size_t *lazy, lazy_cnt;
  62         unsigned char *map;
  63         size_t map_len;
  64         dev_t dev;
  65         ino_t ino;
  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, *syms_tail, *lazy_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         Elf_Symndx *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 = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght;
 262         size_t ghm = 1ul << gh % (8*sizeof(size_t));
 263         struct symdef def = {0};
 264         for (; dso; dso=dso->syms_next) {
 265                 Sym *sym;
 266                 if ((ght = dso->ghashtab)) {
 267                         sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
 268                 } else {
 269                         if (!h) h = sysv_hash(s);
 270                         sym = sysv_lookup(s, h, dso);
 271                 }
 272                 if (!sym) continue;
 273                 if (!sym->st_shndx)
 274                         if (need_def || (sym->st_info&0xf) == STT_TLS
 275                             || ARCH_SYM_REJECT_UND(sym))
 276                                 continue;
 277                 if (!sym->st_value)
 278                         if ((sym->st_info&0xf) != STT_TLS)
 279                                 continue;
 280                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 281                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 282                 def.sym = sym;
 283                 def.dso = dso;
 284                 break;
 285         }
 286         return def;
 287 }
 288
 289 __attribute__((__visibility__("hidden")))
 290 ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
 291
 292 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 293 {
 294         unsigned char *base = dso->base;
 295         Sym *syms = dso->syms;
 296         char *strings = dso->strings;
 297         Sym *sym;
 298         const char *name;
 299         void *ctx;
 300         int type;
 301         int sym_index;
 302         struct symdef def;
 303         size_t *reloc_addr;
 304         size_t sym_val;
 305         size_t tls_val;
 306         size_t addend;
 307         int skip_relative = 0, reuse_addends = 0, save_slot = 0;
 308
 309         if (dso == &ldso) {
 310                 /* Only ldso's REL table needs addend saving/reuse. */
 311                 if (rel == apply_addends_to)
 312                         reuse_addends = 1;
 313                 skip_relative = 1;
 314         }
 315
 316         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 317                 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
 318                 type = R_TYPE(rel[1]);
 319                 if (type == REL_NONE) continue;
 320                 reloc_addr = laddr(dso, rel[0]);
 321
 322                 if (stride > 2) {
 323                         addend = rel[2];
 324                 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
 325                         addend = 0;
 326                 } else if (reuse_addends) {
 327                         /* Save original addend in stage 2 where the dso
 328                          * chain consists of just ldso; otherwise read back
 329                          * saved addend since the inline one was clobbered. */
 330                         if (head==&ldso)
 331                                 saved_addends[save_slot] = *reloc_addr;
 332                         addend = saved_addends[save_slot++];
 333                 } else {
 334                         addend = *reloc_addr;
 335                 }
 336
 337                 sym_index = R_SYM(rel[1]);
 338                 if (sym_index) {
 339                         sym = syms + sym_index;
 340                         name = strings + sym->st_name;
 341                         ctx = type==REL_COPY ? head->syms_next : head;
 342                         def = (sym->st_info&0xf) == STT_SECTION
 343                                 ? (struct symdef){ .dso = dso, .sym = sym }
 344                                 : find_sym(ctx, name, type==REL_PLT);
 345                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 346                             || sym->st_info>>4 != STB_WEAK)) {
 347                                 if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
 348                                         dso->lazy[3*dso->lazy_cnt+0] = rel[0];
 349                                         dso->lazy[3*dso->lazy_cnt+1] = rel[1];
 350                                         dso->lazy[3*dso->lazy_cnt+2] = addend;
 351                                         dso->lazy_cnt++;
 352                                         continue;
 353                                 }
 354                                 error("Error relocating %s: %s: symbol not found",
 355                                         dso->name, name);
 356                                 if (runtime) longjmp(*rtld_fail, 1);
 357                                 continue;
 358                         }
 359                 } else {
 360                         sym = 0;
 361                         def.sym = 0;
 362                         def.dso = dso;
 363                 }
 364
 365                 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
 366                 tls_val = def.sym ? def.sym->st_value : 0;
 367
 368                 switch(type) {
 369                 case REL_NONE:
 370                         break;
 371                 case REL_OFFSET:
 372                         addend -= (size_t)reloc_addr;
 373                 case REL_SYMBOLIC:
 374                 case REL_GOT:
 375                 case REL_PLT:
 376                         *reloc_addr = sym_val + addend;
 377                         break;
 378                 case REL_RELATIVE:
 379                         *reloc_addr = (size_t)base + addend;
 380                         break;
 381                 case REL_SYM_OR_REL:
 382                         if (sym) *reloc_addr = sym_val + addend;
 383                         else *reloc_addr = (size_t)base + addend;
 384                         break;
 385                 case REL_COPY:
 386                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 387                         break;
 388                 case REL_OFFSET32:
 389                         *(uint32_t *)reloc_addr = sym_val + addend
 390                                 - (size_t)reloc_addr;
 391                         break;
 392                 case REL_FUNCDESC:
 393                         *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
 394                                 + (def.sym - def.dso->syms)) : 0;
 395                         break;
 396                 case REL_FUNCDESC_VAL:
 397                         if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
 398                         else *reloc_addr = sym_val;
 399                         reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
 400                         break;
 401                 case REL_DTPMOD:
 402                         *reloc_addr = def.dso->tls_id;
 403                         break;
 404                 case REL_DTPOFF:
 405                         *reloc_addr = tls_val + addend - DTP_OFFSET;
 406                         break;
 407 #ifdef TLS_ABOVE_TP
 408                 case REL_TPOFF:
 409                         *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
 410                         break;
 411 #else
 412                 case REL_TPOFF:
 413                         *reloc_addr = tls_val - def.dso->tls.offset + addend;
 414                         break;
 415                 case REL_TPOFF_NEG:
 416                         *reloc_addr = def.dso->tls.offset - tls_val + addend;
 417                         break;
 418 #endif
 419                 case REL_TLSDESC:
 420                         if (stride<3) addend = reloc_addr[1];
 421                         if (runtime && def.dso->tls_id >= static_tls_cnt) {
 422                                 struct td_index *new = malloc(sizeof *new);
 423                                 if (!new) {
 424                                         error(
 425                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 426                                         dso->name, sym ? name : "(local)" );
 427                                         longjmp(*rtld_fail, 1);
 428                                 }
 429                                 new->next = dso->td_index;
 430                                 dso->td_index = new;
 431                                 new->args[0] = def.dso->tls_id;
 432                                 new->args[1] = tls_val + addend;
 433                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 434                                 reloc_addr[1] = (size_t)new;
 435                         } else {
 436                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 437 #ifdef TLS_ABOVE_TP
 438                                 reloc_addr[1] = tls_val + def.dso->tls.offset
 439                                         + TPOFF_K + addend;
 440 #else
 441                                 reloc_addr[1] = tls_val - def.dso->tls.offset
 442                                         + addend;
 443 #endif
 444                         }
 445                         break;
 446                 default:
 447                         error("Error relocating %s: unsupported relocation type %d",
 448                                 dso->name, type);
 449                         if (runtime) longjmp(*rtld_fail, 1);
 450                         continue;
 451                 }
 452         }
 453 }
 454
 455 static void redo_lazy_relocs()
 456 {
 457         struct dso *p = lazy_head, *next;
 458         lazy_head = 0;
 459         for (; p; p=next) {
 460                 next = p->lazy_next;
 461                 size_t size = p->lazy_cnt*3*sizeof(size_t);
 462                 p->lazy_cnt = 0;
 463                 do_relocs(p, p->lazy, size, 3);
 464                 if (p->lazy_cnt) {
 465                         p->lazy_next = lazy_head;
 466                         lazy_head = p;
 467                 } else {
 468                         free(p->lazy);
 469                         p->lazy = 0;
 470                         p->lazy_next = 0;
 471                 }
 472         }
 473 }
 474
 475 /* A huge hack: to make up for the wastefulness of shared libraries
 476  * needing at least a page of dirty memory even if they have no global
 477  * data, we reclaim the gaps at the beginning and end of writable maps
 478  * and "donate" them to the heap by setting up minimal malloc
 479  * structures and then freeing them. */
 480
 481 static void reclaim(struct dso *dso, size_t start, size_t end)
 482 {
 483         size_t *a, *z;
 484         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 485         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 486         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 487         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 488         if (start>end || end-start < 4*sizeof(size_t)) return;
 489         a = laddr(dso, start);
 490         z = laddr(dso, end);
 491         a[-2] = 1;
 492         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 493         z[1] = 1;
 494         free(a);
 495 }
 496
 497 static void reclaim_gaps(struct dso *dso)
 498 {
 499         Phdr *ph = dso->phdr;
 500         size_t phcnt = dso->phnum;
 501
 502         if (DL_FDPIC) return; // FIXME
 503         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 504                 if (ph->p_type!=PT_LOAD) continue;
 505                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 506                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 507                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 508                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 509         }
 510 }
 511
 512 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
 513 {
 514         static int no_map_fixed;
 515         char *q;
 516         if (!no_map_fixed) {
 517                 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
 518                 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
 519                         return q;
 520                 no_map_fixed = 1;
 521         }
 522         /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
 523         if (flags & MAP_ANONYMOUS) {
 524                 memset(p, 0, n);
 525                 return p;
 526         }
 527         ssize_t r;
 528         if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
 529         for (q=p; n; q+=r, off+=r, n-=r) {
 530                 r = read(fd, q, n);
 531                 if (r < 0 && errno != EINTR) return MAP_FAILED;
 532                 if (!r) {
 533                         memset(q, 0, n);
 534                         break;
 535                 }
 536         }
 537         return p;
 538 }
 539
 540 static void unmap_library(struct dso *dso)
 541 {
 542         if (dso->loadmap) {
 543                 size_t i;
 544                 for (i=0; i<dso->loadmap->nsegs; i++) {
 545                         if (!dso->loadmap->segs[i].p_memsz)
 546                                 continue;
 547                         munmap((void *)dso->loadmap->segs[i].addr,
 548                                 dso->loadmap->segs[i].p_memsz);
 549                 }
 550                 free(dso->loadmap);
 551         } else if (dso->map && dso->map_len) {
 552                 munmap(dso->map, dso->map_len);
 553         }
 554 }
 555
 556 static void *map_library(int fd, struct dso *dso)
 557 {
 558         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 559         void *allocated_buf=0;
 560         size_t phsize;
 561         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 562         size_t this_min, this_max;
 563         size_t nsegs = 0;
 564         off_t off_start;
 565         Ehdr *eh;
 566         Phdr *ph, *ph0;
 567         unsigned prot;
 568         unsigned char *map=MAP_FAILED, *base;
 569         size_t dyn=0;
 570         size_t tls_image=0;
 571         size_t i;
 572
 573         ssize_t l = read(fd, buf, sizeof buf);
 574         eh = buf;
 575         if (l<0) return 0;
 576         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 577                 goto noexec;
 578         phsize = eh->e_phentsize * eh->e_phnum;
 579         if (phsize > sizeof buf - sizeof *eh) {
 580                 allocated_buf = malloc(phsize);
 581                 if (!allocated_buf) return 0;
 582                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 583                 if (l < 0) goto error;
 584                 if (l != phsize) goto noexec;
 585                 ph = ph0 = allocated_buf;
 586         } else if (eh->e_phoff + phsize > l) {
 587                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 588                 if (l < 0) goto error;
 589                 if (l != phsize) goto noexec;
 590                 ph = ph0 = (void *)(buf + 1);
 591         } else {
 592                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 593         }
 594         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 595                 if (ph->p_type == PT_DYNAMIC) {
 596                         dyn = ph->p_vaddr;
 597                 } else if (ph->p_type == PT_TLS) {
 598                         tls_image = ph->p_vaddr;
 599                         dso->tls.align = ph->p_align;
 600                         dso->tls.len = ph->p_filesz;
 601                         dso->tls.size = ph->p_memsz;
 602                 } else if (ph->p_type == PT_GNU_RELRO) {
 603                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 604                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 605                 }
 606                 if (ph->p_type != PT_LOAD) continue;
 607                 nsegs++;
 608                 if (ph->p_vaddr < addr_min) {
 609                         addr_min = ph->p_vaddr;
 610                         off_start = ph->p_offset;
 611                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 612                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 613                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 614                 }
 615                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 616                         addr_max = ph->p_vaddr+ph->p_memsz;
 617                 }
 618         }
 619         if (!dyn) goto noexec;
 620         if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
 621                 dso->loadmap = calloc(1, sizeof *dso->loadmap
 622                         + nsegs * sizeof *dso->loadmap->segs);
 623                 if (!dso->loadmap) goto error;
 624                 dso->loadmap->nsegs = nsegs;
 625                 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
 626                         if (ph->p_type != PT_LOAD) continue;
 627                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 628                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 629                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 630                         map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
 631                                 prot, MAP_PRIVATE,
 632                                 fd, ph->p_offset & -PAGE_SIZE);
 633                         if (map == MAP_FAILED) {
 634                                 unmap_library(dso);
 635                                 goto error;
 636                         }
 637                         dso->loadmap->segs[i].addr = (size_t)map +
 638                                 (ph->p_vaddr & PAGE_SIZE-1);
 639                         dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
 640                         dso->loadmap->segs[i].p_memsz = ph->p_memsz;
 641                         i++;
 642                         if (prot & PROT_WRITE) {
 643                                 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
 644                                         + ph->p_filesz;
 645                                 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
 646                                 size_t pgend = brk + ph->p_memsz - ph->p_filesz
 647                                         + PAGE_SIZE-1 & -PAGE_SIZE;
 648                                 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
 649                                         pgend-pgbrk, prot,
 650                                         MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
 651                                         -1, off_start) == MAP_FAILED)
 652                                         goto error;
 653                                 memset(map + brk, 0, pgbrk-brk);
 654                         }
 655                 }
 656                 map = (void *)dso->loadmap->segs[0].addr;
 657                 map_len = 0;
 658                 goto done_mapping;
 659         }
 660         addr_max += PAGE_SIZE-1;
 661         addr_max &= -PAGE_SIZE;
 662         addr_min &= -PAGE_SIZE;
 663         off_start &= -PAGE_SIZE;
 664         map_len = addr_max - addr_min + off_start;
 665         /* The first time, we map too much, possibly even more than
 666          * the length of the file. This is okay because we will not
 667          * use the invalid part; we just need to reserve the right
 668          * amount of virtual address space to map over later. */
 669         map = DL_NOMMU_SUPPORT
 670                 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
 671                         MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
 672                 : mmap((void *)addr_min, map_len, prot,
 673                         MAP_PRIVATE, fd, off_start);
 674         if (map==MAP_FAILED) goto error;
 675         dso->map = map;
 676         dso->map_len = map_len;
 677         /* If the loaded file is not relocatable and the requested address is
 678          * not available, then the load operation must fail. */
 679         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 680                 errno = EBUSY;
 681                 goto error;
 682         }
 683         base = map - addr_min;
 684         dso->phdr = 0;
 685         dso->phnum = 0;
 686         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 687                 if (ph->p_type != PT_LOAD) continue;
 688                 /* Check if the programs headers are in this load segment, and
 689                  * if so, record the address for use by dl_iterate_phdr. */
 690                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 691                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 692                         dso->phdr = (void *)(base + ph->p_vaddr
 693                                 + (eh->e_phoff-ph->p_offset));
 694                         dso->phnum = eh->e_phnum;
 695                         dso->phentsize = eh->e_phentsize;
 696                 }
 697                 /* Reuse the existing mapping for the lowest-address LOAD */
 698                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min && !DL_NOMMU_SUPPORT)
 699                         continue;
 700                 this_min = ph->p_vaddr & -PAGE_SIZE;
 701                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 702                 off_start = ph->p_offset & -PAGE_SIZE;
 703                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 704                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 705                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 706                 if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 707                         goto error;
 708                 if (ph->p_memsz > ph->p_filesz) {
 709                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 710                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 711                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 712                         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)
 713                                 goto error;
 714                 }
 715         }
 716         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 717                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 718                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
 719                             && errno != ENOSYS)
 720                                 goto error;
 721                         break;
 722                 }
 723 done_mapping:
 724         dso->base = base;
 725         dso->dynv = laddr(dso, dyn);
 726         if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
 727         if (!runtime) reclaim_gaps(dso);
 728         free(allocated_buf);
 729         return map;
 730 noexec:
 731         errno = ENOEXEC;
 732 error:
 733         if (map!=MAP_FAILED) unmap_library(dso);
 734         free(allocated_buf);
 735         return 0;
 736 }
 737
 738 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 739 {
 740         size_t l;
 741         int fd;
 742         for (;;) {
 743                 s += strspn(s, ":\n");
 744                 l = strcspn(s, ":\n");
 745                 if (l-1 >= INT_MAX) return -1;
 746                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
 747                         if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 748                         switch (errno) {
 749                         case ENOENT:
 750                         case ENOTDIR:
 751                         case EACCES:
 752                         case ENAMETOOLONG:
 753                                 break;
 754                         default:
 755                                 /* Any negative value but -1 will inhibit
 756                                  * futher path search. */
 757                                 return -2;
 758                         }
 759                 }
 760                 s += l;
 761         }
 762 }
 763
 764 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 765 {
 766         size_t n, l;
 767         const char *s, *t, *origin;
 768         char *d;
 769         if (p->rpath || !p->rpath_orig) return 0;
 770         if (!strchr(p->rpath_orig, '$')) {
 771                 p->rpath = p->rpath_orig;
 772                 return 0;
 773         }
 774         n = 0;
 775         s = p->rpath_orig;
 776         while ((t=strchr(s, '$'))) {
 777                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 778                         return 0;
 779                 s = t+1;
 780                 n++;
 781         }
 782         if (n > SSIZE_MAX/PATH_MAX) return 0;
 783
 784         if (p->kernel_mapped) {
 785                 /* $ORIGIN searches cannot be performed for the main program
 786                  * when it is suid/sgid/AT_SECURE. This is because the
 787                  * pathname is under the control of the caller of execve.
 788                  * For libraries, however, $ORIGIN can be processed safely
 789                  * since the library's pathname came from a trusted source
 790                  * (either system paths or a call to dlopen). */
 791                 if (libc.secure)
 792                         return 0;
 793                 l = readlink("/proc/self/exe", buf, buf_size);
 794                 if (l == -1) switch (errno) {
 795                 case ENOENT:
 796                 case ENOTDIR:
 797                 case EACCES:
 798                         break;
 799                 default:
 800                         return -1;
 801                 }
 802                 if (l >= buf_size)
 803                         return 0;
 804                 buf[l] = 0;
 805                 origin = buf;
 806         } else {
 807                 origin = p->name;
 808         }
 809         t = strrchr(origin, '/');
 810         l = t ? t-origin : 0;
 811         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 812         if (!p->rpath) return -1;
 813
 814         d = p->rpath;
 815         s = p->rpath_orig;
 816         while ((t=strchr(s, '$'))) {
 817                 memcpy(d, s, t-s);
 818                 d += t-s;
 819                 memcpy(d, origin, l);
 820                 d += l;
 821                 /* It was determined previously that the '$' is followed
 822                  * either by "ORIGIN" or "{ORIGIN}". */
 823                 s = t + 7 + 2*(t[1]=='{');
 824         }
 825         strcpy(d, s);
 826         return 0;
 827 }
 828
 829 static void decode_dyn(struct dso *p)
 830 {
 831         size_t dyn[DYN_CNT];
 832         decode_vec(p->dynv, dyn, DYN_CNT);
 833         p->syms = laddr(p, dyn[DT_SYMTAB]);
 834         p->strings = laddr(p, dyn[DT_STRTAB]);
 835         if (dyn[0]&(1<<DT_HASH))
 836                 p->hashtab = laddr(p, dyn[DT_HASH]);
 837         if (dyn[0]&(1<<DT_RPATH))
 838                 p->rpath_orig = p->strings + dyn[DT_RPATH];
 839         if (dyn[0]&(1<<DT_RUNPATH))
 840                 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
 841         if (dyn[0]&(1<<DT_PLTGOT))
 842                 p->got = laddr(p, dyn[DT_PLTGOT]);
 843         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 844                 p->ghashtab = laddr(p, *dyn);
 845         if (search_vec(p->dynv, dyn, DT_VERSYM))
 846                 p->versym = laddr(p, *dyn);
 847 }
 848
 849 static size_t count_syms(struct dso *p)
 850 {
 851         if (p->hashtab) return p->hashtab[1];
 852
 853         size_t nsym, i;
 854         uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
 855         uint32_t *hashval;
 856         for (i = nsym = 0; i < p->ghashtab[0]; i++) {
 857                 if (buckets[i] > nsym)
 858                         nsym = buckets[i];
 859         }
 860         if (nsym) {
 861                 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
 862                 do nsym++;
 863                 while (!(*hashval++ & 1));
 864         }
 865         return nsym;
 866 }
 867
 868 static void *dl_mmap(size_t n)
 869 {
 870         void *p;
 871         int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
 872 #ifdef SYS_mmap2
 873         p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
 874 #else
 875         p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
 876 #endif
 877         return p == MAP_FAILED ? 0 : p;
 878 }
 879
 880 static void makefuncdescs(struct dso *p)
 881 {
 882         static int self_done;
 883         size_t nsym = count_syms(p);
 884         size_t i, size = nsym * sizeof(*p->funcdescs);
 885
 886         if (!self_done) {
 887                 p->funcdescs = dl_mmap(size);
 888                 self_done = 1;
 889         } else {
 890                 p->funcdescs = malloc(size);
 891         }
 892         if (!p->funcdescs) {
 893                 if (!runtime) a_crash();
 894                 error("Error allocating function descriptors for %s", p->name);
 895                 longjmp(*rtld_fail, 1);
 896         }
 897         for (i=0; i<nsym; i++) {
 898                 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
 899                         p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
 900                         p->funcdescs[i].got = p->got;
 901                 } else {
 902                         p->funcdescs[i].addr = 0;
 903                         p->funcdescs[i].got = 0;
 904                 }
 905         }
 906 }
 907
 908 static struct dso *load_library(const char *name, struct dso *needed_by)
 909 {
 910         char buf[2*NAME_MAX+2];
 911         const char *pathname;
 912         unsigned char *map;
 913         struct dso *p, temp_dso = {0};
 914         int fd;
 915         struct stat st;
 916         size_t alloc_size;
 917         int n_th = 0;
 918         int is_self = 0;
 919
 920         if (!*name) {
 921                 errno = EINVAL;
 922                 return 0;
 923         }
 924
 925         /* Catch and block attempts to reload the implementation itself */
 926         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 927                 static const char reserved[] =
 928                         "c.pthread.rt.m.dl.util.xnet.";
 929                 const char *rp, *next;
 930                 for (rp=reserved; *rp; rp=next) {
 931                         next = strchr(rp, '.') + 1;
 932                         if (strncmp(name+3, rp, next-rp) == 0)
 933                                 break;
 934                 }
 935                 if (*rp) {
 936                         if (ldd_mode) {
 937                                 /* Track which names have been resolved
 938                                  * and only report each one once. */
 939                                 static unsigned reported;
 940                                 unsigned mask = 1U<<(rp-reserved);
 941                                 if (!(reported & mask)) {
 942                                         reported |= mask;
 943                                         dprintf(1, "\t%s => %s (%p)\n",
 944                                                 name, ldso.name,
 945                                                 ldso.base);
 946                                 }
 947                         }
 948                         is_self = 1;
 949                 }
 950         }
 951         if (!strcmp(name, ldso.name)) is_self = 1;
 952         if (is_self) {
 953                 if (!ldso.prev) {
 954                         tail->next = &ldso;
 955                         ldso.prev = tail;
 956                         tail = &ldso;
 957                 }
 958                 return &ldso;
 959         }
 960         if (strchr(name, '/')) {
 961                 pathname = name;
 962                 fd = open(name, O_RDONLY|O_CLOEXEC);
 963         } else {
 964                 /* Search for the name to see if it's already loaded */
 965                 for (p=head->next; p; p=p->next) {
 966                         if (p->shortname && !strcmp(p->shortname, name)) {
 967                                 return p;
 968                         }
 969                 }
 970                 if (strlen(name) > NAME_MAX) return 0;
 971                 fd = -1;
 972                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 973                 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
 974                         if (fixup_rpath(p, buf, sizeof buf) < 0)
 975                                 fd = -2; /* Inhibit further search. */
 976                         if (p->rpath)
 977                                 fd = path_open(name, p->rpath, buf, sizeof buf);
 978                 }
 979                 if (fd == -1) {
 980                         if (!sys_path) {
 981                                 char *prefix = 0;
 982                                 size_t prefix_len;
 983                                 if (ldso.name[0]=='/') {
 984                                         char *s, *t, *z;
 985                                         for (s=t=z=ldso.name; *s; s++)
 986                                                 if (*s=='/') z=t, t=s;
 987                                         prefix_len = z-ldso.name;
 988                                         if (prefix_len < PATH_MAX)
 989                                                 prefix = ldso.name;
 990                                 }
 991                                 if (!prefix) {
 992                                         prefix = "";
 993                                         prefix_len = 0;
 994                                 }
 995                                 char etc_ldso_path[prefix_len + 1
 996                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
 997                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
 998                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 999                                         (int)prefix_len, prefix);
1000                                 FILE *f = fopen(etc_ldso_path, "rbe");
1001                                 if (f) {
1002                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
1003                                                 free(sys_path);
1004                                                 sys_path = "";
1005                                         }
1006                                         fclose(f);
1007                                 } else if (errno != ENOENT) {
1008                                         sys_path = "";
1009                                 }
1010                         }
1011                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
1012                         fd = path_open(name, sys_path, buf, sizeof buf);
1013                 }
1014                 pathname = buf;
1015         }
1016         if (fd < 0) return 0;
1017         if (fstat(fd, &st) < 0) {
1018                 close(fd);
1019                 return 0;
1020         }
1021         for (p=head->next; p; p=p->next) {
1022                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1023                         /* If this library was previously loaded with a
1024                          * pathname but a search found the same inode,
1025                          * setup its shortname so it can be found by name. */
1026                         if (!p->shortname && pathname != name)
1027                                 p->shortname = strrchr(p->name, '/')+1;
1028                         close(fd);
1029                         return p;
1030                 }
1031         }
1032         map = noload ? 0 : map_library(fd, &temp_dso);
1033         close(fd);
1034         if (!map) return 0;
1035
1036         /* Avoid the danger of getting two versions of libc mapped into the
1037          * same process when an absolute pathname was used. The symbols
1038          * checked are chosen to catch both musl and glibc, and to avoid
1039          * false positives from interposition-hack libraries. */
1040         decode_dyn(&temp_dso);
1041         if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
1042             find_sym(&temp_dso, "stdin", 1).sym) {
1043                 unmap_library(&temp_dso);
1044                 return load_library("libc.so", needed_by);
1045         }
1046
1047         /* Allocate storage for the new DSO. When there is TLS, this
1048          * storage must include a reservation for all pre-existing
1049          * threads to obtain copies of both the new TLS, and an
1050          * extended DTV capable of storing an additional slot for
1051          * the newly-loaded DSO. */
1052         alloc_size = sizeof *p + strlen(pathname) + 1;
1053         if (runtime && temp_dso.tls.image) {
1054                 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1055                         + sizeof(void *) * (tls_cnt+3);
1056                 n_th = libc.threads_minus_1 + 1;
1057                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1058                 else alloc_size += n_th * per_th;
1059         }
1060         p = calloc(1, alloc_size);
1061         if (!p) {
1062                 unmap_library(&temp_dso);
1063                 return 0;
1064         }
1065         memcpy(p, &temp_dso, sizeof temp_dso);
1066         p->dev = st.st_dev;
1067         p->ino = st.st_ino;
1068         p->needed_by = needed_by;
1069         p->name = p->buf;
1070         strcpy(p->name, pathname);
1071         /* Add a shortname only if name arg was not an explicit pathname. */
1072         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1073         if (p->tls.image) {
1074                 p->tls_id = ++tls_cnt;
1075                 tls_align = MAXP2(tls_align, p->tls.align);
1076 #ifdef TLS_ABOVE_TP
1077                 p->tls.offset = tls_offset + ( (tls_align-1) &
1078                         -(tls_offset + (uintptr_t)p->tls.image) );
1079                 tls_offset += p->tls.size;
1080 #else
1081                 tls_offset += p->tls.size + p->tls.align - 1;
1082                 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1083                         & (p->tls.align-1);
1084                 p->tls.offset = tls_offset;
1085 #endif
1086                 p->new_dtv = (void *)(-sizeof(size_t) &
1087                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1088                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1089                 if (tls_tail) tls_tail->next = &p->tls;
1090                 else libc.tls_head = &p->tls;
1091                 tls_tail = &p->tls;
1092         }
1093
1094         tail->next = p;
1095         p->prev = tail;
1096         tail = p;
1097
1098         if (DL_FDPIC) makefuncdescs(p);
1099
1100         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1101
1102         return p;
1103 }
1104
1105 static void load_deps(struct dso *p)
1106 {
1107         size_t i, ndeps=0;
1108         struct dso ***deps = &p->deps, **tmp, *dep;
1109         for (; p; p=p->next) {
1110                 for (i=0; p->dynv[i]; i+=2) {
1111                         if (p->dynv[i] != DT_NEEDED) continue;
1112                         dep = load_library(p->strings + p->dynv[i+1], p);
1113                         if (!dep) {
1114                                 error("Error loading shared library %s: %m (needed by %s)",
1115                                         p->strings + p->dynv[i+1], p->name);
1116                                 if (runtime) longjmp(*rtld_fail, 1);
1117                                 continue;
1118                         }
1119                         if (runtime) {
1120                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
1121                                 if (!tmp) longjmp(*rtld_fail, 1);
1122                                 tmp[ndeps++] = dep;
1123                                 tmp[ndeps] = 0;
1124                                 *deps = tmp;
1125                         }
1126                 }
1127         }
1128 }
1129
1130 static void load_preload(char *s)
1131 {
1132         int tmp;
1133         char *z;
1134         for (z=s; *z; s=z) {
1135                 for (   ; *s && (isspace(*s) || *s==':'); s++);
1136                 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1137                 tmp = *z;
1138                 *z = 0;
1139                 load_library(s, 0);
1140                 *z = tmp;
1141         }
1142 }
1143
1144 static void add_syms(struct dso *p)
1145 {
1146         if (!p->syms_next && syms_tail != p) {
1147                 syms_tail->syms_next = p;
1148                 syms_tail = p;
1149         }
1150 }
1151
1152 static void revert_syms(struct dso *old_tail)
1153 {
1154         struct dso *p, *next;
1155         /* Chop off the tail of the list of dsos that participate in
1156          * the global symbol table, reverting them to RTLD_LOCAL. */
1157         for (p=old_tail; p; p=next) {
1158                 next = p->syms_next;
1159                 p->syms_next = 0;
1160         }
1161         syms_tail = old_tail;
1162 }
1163
1164 static void do_mips_relocs(struct dso *p, size_t *got)
1165 {
1166         size_t i, j, rel[2];
1167         unsigned char *base = p->base;
1168         i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1169         if (p==&ldso) {
1170                 got += i;
1171         } else {
1172                 while (i--) *got++ += (size_t)base;
1173         }
1174         j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1175         i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1176         Sym *sym = p->syms + j;
1177         rel[0] = (unsigned char *)got - base;
1178         for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1179                 rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
1180                 do_relocs(p, rel, sizeof rel, 2);
1181         }
1182 }
1183
1184 static void reloc_all(struct dso *p)
1185 {
1186         size_t dyn[DYN_CNT];
1187         for (; p; p=p->next) {
1188                 if (p->relocated) continue;
1189                 decode_vec(p->dynv, dyn, DYN_CNT);
1190                 if (NEED_MIPS_GOT_RELOCS)
1191                         do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1192                 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1193                         2+(dyn[DT_PLTREL]==DT_RELA));
1194                 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1195                 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1196
1197                 if (head != &ldso && p->relro_start != p->relro_end &&
1198                     mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1199                     && errno != ENOSYS) {
1200                         error("Error relocating %s: RELRO protection failed: %m",
1201                                 p->name);
1202                         if (runtime) longjmp(*rtld_fail, 1);
1203                 }
1204
1205                 p->relocated = 1;
1206         }
1207 }
1208
1209 static void kernel_mapped_dso(struct dso *p)
1210 {
1211         size_t min_addr = -1, max_addr = 0, cnt;
1212         Phdr *ph = p->phdr;
1213         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1214                 if (ph->p_type == PT_DYNAMIC) {
1215                         p->dynv = laddr(p, ph->p_vaddr);
1216                 } else if (ph->p_type == PT_GNU_RELRO) {
1217                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1218                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1219                 }
1220                 if (ph->p_type != PT_LOAD) continue;
1221                 if (ph->p_vaddr < min_addr)
1222                         min_addr = ph->p_vaddr;
1223                 if (ph->p_vaddr+ph->p_memsz > max_addr)
1224                         max_addr = ph->p_vaddr+ph->p_memsz;
1225         }
1226         min_addr &= -PAGE_SIZE;
1227         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1228         p->map = p->base + min_addr;
1229         p->map_len = max_addr - min_addr;
1230         p->kernel_mapped = 1;
1231 }
1232
1233 void __libc_exit_fini()
1234 {
1235         struct dso *p;
1236         size_t dyn[DYN_CNT];
1237         for (p=fini_head; p; p=p->fini_next) {
1238                 if (!p->constructed) continue;
1239                 decode_vec(p->dynv, dyn, DYN_CNT);
1240                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1241                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1242                         size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1243                         while (n--) ((void (*)(void))*--fn)();
1244                 }
1245 #ifndef NO_LEGACY_INITFINI
1246                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1247                         fpaddr(p, dyn[DT_FINI])();
1248 #endif
1249         }
1250 }
1251
1252 static void do_init_fini(struct dso *p)
1253 {
1254         size_t dyn[DYN_CNT];
1255         int need_locking = libc.threads_minus_1;
1256         /* Allow recursive calls that arise when a library calls
1257          * dlopen from one of its constructors, but block any
1258          * other threads until all ctors have finished. */
1259         if (need_locking) pthread_mutex_lock(&init_fini_lock);
1260         for (; p; p=p->prev) {
1261                 if (p->constructed) continue;
1262                 p->constructed = 1;
1263                 decode_vec(p->dynv, dyn, DYN_CNT);
1264                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1265                         p->fini_next = fini_head;
1266                         fini_head = p;
1267                 }
1268 #ifndef NO_LEGACY_INITFINI
1269                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1270                         fpaddr(p, dyn[DT_INIT])();
1271 #endif
1272                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1273                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1274                         size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1275                         while (n--) ((void (*)(void))*fn++)();
1276                 }
1277                 if (!need_locking && libc.threads_minus_1) {
1278                         need_locking = 1;
1279                         pthread_mutex_lock(&init_fini_lock);
1280                 }
1281         }
1282         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1283 }
1284
1285 void __libc_start_init(void)
1286 {
1287         do_init_fini(tail);
1288 }
1289
1290 static void dl_debug_state(void)
1291 {
1292 }
1293
1294 weak_alias(dl_debug_state, _dl_debug_state);
1295
1296 void __init_tls(size_t *auxv)
1297 {
1298 }
1299
1300 __attribute__((__visibility__("hidden")))
1301 void *__tls_get_new(tls_mod_off_t *v)
1302 {
1303         pthread_t self = __pthread_self();
1304
1305         /* Block signals to make accessing new TLS async-signal-safe */
1306         sigset_t set;
1307         __block_all_sigs(&set);
1308         if (v[0]<=(size_t)self->dtv[0]) {
1309                 __restore_sigs(&set);
1310                 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1311         }
1312
1313         /* This is safe without any locks held because, if the caller
1314          * is able to request the Nth entry of the DTV, the DSO list
1315          * must be valid at least that far out and it was synchronized
1316          * at program startup or by an already-completed call to dlopen. */
1317         struct dso *p;
1318         for (p=head; p->tls_id != v[0]; p=p->next);
1319
1320         /* Get new DTV space from new DSO if needed */
1321         if (v[0] > (size_t)self->dtv[0]) {
1322                 void **newdtv = p->new_dtv +
1323                         (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
1324                 memcpy(newdtv, self->dtv,
1325                         ((size_t)self->dtv[0]+1) * sizeof(void *));
1326                 newdtv[0] = (void *)v[0];
1327                 self->dtv = self->dtv_copy = newdtv;
1328         }
1329
1330         /* Get new TLS memory from all new DSOs up to the requested one */
1331         unsigned char *mem;
1332         for (p=head; ; p=p->next) {
1333                 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1334                 mem = p->new_tls + (p->tls.size + p->tls.align)
1335                         * a_fetch_add(&p->new_tls_idx,1);
1336                 mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1337                         & (p->tls.align-1);
1338                 self->dtv[p->tls_id] = mem;
1339                 memcpy(mem, p->tls.image, p->tls.len);
1340                 if (p->tls_id == v[0]) break;
1341         }
1342         __restore_sigs(&set);
1343         return mem + v[1] + DTP_OFFSET;
1344 }
1345
1346 static void update_tls_size()
1347 {
1348         libc.tls_cnt = tls_cnt;
1349         libc.tls_align = tls_align;
1350         libc.tls_size = ALIGN(
1351                 (1+tls_cnt) * sizeof(void *) +
1352                 tls_offset +
1353                 sizeof(struct pthread) +
1354                 tls_align * 2,
1355         tls_align);
1356 }
1357
1358 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1359  * following stage 2 and stage 3 functions via primitive symbolic lookup
1360  * since it does not have access to their addresses to begin with. */
1361
1362 /* Stage 2 of the dynamic linker is called after relative relocations
1363  * have been processed. It can make function calls to static functions
1364  * and access string literals and static data, but cannot use extern
1365  * symbols. Its job is to perform symbolic relocations on the dynamic
1366  * linker itself, but some of the relocations performed may need to be
1367  * replaced later due to copy relocations in the main program. */
1368
1369 __attribute__((__visibility__("hidden")))
1370 void __dls2(unsigned char *base, size_t *sp)
1371 {
1372         if (DL_FDPIC) {
1373                 void *p1 = (void *)sp[-2];
1374                 void *p2 = (void *)sp[-1];
1375                 if (!p1) {
1376                         size_t *auxv, aux[AUX_CNT];
1377                         for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
1378                         decode_vec(auxv, aux, AUX_CNT);
1379                         if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1380                         else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1381                 }
1382                 app_loadmap = p2 ? p1 : 0;
1383                 ldso.loadmap = p2 ? p2 : p1;
1384                 ldso.base = laddr(&ldso, 0);
1385         } else {
1386                 ldso.base = base;
1387         }
1388         Ehdr *ehdr = (void *)ldso.base;
1389         ldso.name = ldso.shortname = "libc.so";
1390         ldso.phnum = ehdr->e_phnum;
1391         ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1392         ldso.phentsize = ehdr->e_phentsize;
1393         kernel_mapped_dso(&ldso);
1394         decode_dyn(&ldso);
1395
1396         if (DL_FDPIC) makefuncdescs(&ldso);
1397
1398         /* Prepare storage for to save clobbered REL addends so they
1399          * can be reused in stage 3. There should be very few. If
1400          * something goes wrong and there are a huge number, abort
1401          * instead of risking stack overflow. */
1402         size_t dyn[DYN_CNT];
1403         decode_vec(ldso.dynv, dyn, DYN_CNT);
1404         size_t *rel = laddr(&ldso, dyn[DT_REL]);
1405         size_t rel_size = dyn[DT_RELSZ];
1406         size_t symbolic_rel_cnt = 0;
1407         apply_addends_to = rel;
1408         for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1409                 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1410         if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1411         size_t addends[symbolic_rel_cnt+1];
1412         saved_addends = addends;
1413
1414         head = &ldso;
1415         reloc_all(&ldso);
1416
1417         ldso.relocated = 0;
1418
1419         /* Call dynamic linker stage-3, __dls3, looking it up
1420          * symbolically as a barrier against moving the address
1421          * load across the above relocation processing. */
1422         struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1423         if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1424         else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1425 }
1426
1427 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1428  * fully functional. Its job is to load (if not already loaded) and
1429  * process dependencies and relocations for the main application and
1430  * transfer control to its entry point. */
1431
1432 _Noreturn void __dls3(size_t *sp)
1433 {
1434         static struct dso app, vdso;
1435         size_t aux[AUX_CNT], *auxv;
1436         size_t i;
1437         char *env_preload=0;
1438         size_t vdso_base;
1439         int argc = *sp;
1440         char **argv = (void *)(sp+1);
1441         char **argv_orig = argv;
1442         char **envp = argv+argc+1;
1443
1444         /* Find aux vector just past environ[] and use it to initialize
1445          * global data that may be needed before we can make syscalls. */
1446         __environ = envp;
1447         for (i=argc+1; argv[i]; i++);
1448         libc.auxv = auxv = (void *)(argv+i+1);
1449         decode_vec(auxv, aux, AUX_CNT);
1450         __hwcap = aux[AT_HWCAP];
1451         libc.page_size = aux[AT_PAGESZ];
1452         libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1453                 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1454
1455         /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1456          * use during dynamic linking. If possible it will also serve as the
1457          * thread pointer at runtime. */
1458         libc.tls_size = sizeof builtin_tls;
1459         libc.tls_align = tls_align;
1460         if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1461                 a_crash();
1462         }
1463
1464         /* Only trust user/env if kernel says we're not suid/sgid */
1465         if (!libc.secure) {
1466                 env_path = getenv("LD_LIBRARY_PATH");
1467                 env_preload = getenv("LD_PRELOAD");
1468         }
1469
1470         /* If the main program was already loaded by the kernel,
1471          * AT_PHDR will point to some location other than the dynamic
1472          * linker's program headers. */
1473         if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1474                 size_t interp_off = 0;
1475                 size_t tls_image = 0;
1476                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1477                 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1478                 app.phnum = aux[AT_PHNUM];
1479                 app.phentsize = aux[AT_PHENT];
1480                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1481                         if (phdr->p_type == PT_PHDR)
1482                                 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1483                         else if (phdr->p_type == PT_INTERP)
1484                                 interp_off = (size_t)phdr->p_vaddr;
1485                         else if (phdr->p_type == PT_TLS) {
1486                                 tls_image = phdr->p_vaddr;
1487                                 app.tls.len = phdr->p_filesz;
1488                                 app.tls.size = phdr->p_memsz;
1489                                 app.tls.align = phdr->p_align;
1490                         }
1491                 }
1492                 if (DL_FDPIC) app.loadmap = app_loadmap;
1493                 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1494                 if (interp_off) ldso.name = laddr(&app, interp_off);
1495                 if ((aux[0] & (1UL<<AT_EXECFN))
1496                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1497                         app.name = (char *)aux[AT_EXECFN];
1498                 else
1499                         app.name = argv[0];
1500                 kernel_mapped_dso(&app);
1501         } else {
1502                 int fd;
1503                 char *ldname = argv[0];
1504                 size_t l = strlen(ldname);
1505                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1506                 argv++;
1507                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1508                         char *opt = argv[0]+2;
1509                         *argv++ = (void *)-1;
1510                         if (!*opt) {
1511                                 break;
1512                         } else if (!memcmp(opt, "list", 5)) {
1513                                 ldd_mode = 1;
1514                         } else if (!memcmp(opt, "library-path", 12)) {
1515                                 if (opt[12]=='=') env_path = opt+13;
1516                                 else if (opt[12]) *argv = 0;
1517                                 else if (*argv) env_path = *argv++;
1518                         } else if (!memcmp(opt, "preload", 7)) {
1519                                 if (opt[7]=='=') env_preload = opt+8;
1520                                 else if (opt[7]) *argv = 0;
1521                                 else if (*argv) env_preload = *argv++;
1522                         } else {
1523                                 argv[0] = 0;
1524                         }
1525                 }
1526                 argv[-1] = (void *)(argc - (argv-argv_orig));
1527                 if (!argv[0]) {
1528                         dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1529                                 "Version %s\n"
1530                                 "Dynamic Program Loader\n"
1531                                 "Usage: %s [options] [--] pathname%s\n",
1532                                 __libc_get_version(), ldname,
1533                                 ldd_mode ? "" : " [args]");
1534                         _exit(1);
1535                 }
1536                 fd = open(argv[0], O_RDONLY);
1537                 if (fd < 0) {
1538                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1539                         _exit(1);
1540                 }
1541                 runtime = 1;
1542                 Ehdr *ehdr = (void *)map_library(fd, &app);
1543                 if (!ehdr) {
1544                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1545                         _exit(1);
1546                 }
1547                 runtime = 0;
1548                 close(fd);
1549                 ldso.name = ldname;
1550                 app.name = argv[0];
1551                 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1552                 /* Find the name that would have been used for the dynamic
1553                  * linker had ldd not taken its place. */
1554                 if (ldd_mode) {
1555                         for (i=0; i<app.phnum; i++) {
1556                                 if (app.phdr[i].p_type == PT_INTERP)
1557                                         ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1558                         }
1559                         dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1560                 }
1561         }
1562         if (app.tls.size) {
1563                 libc.tls_head = tls_tail = &app.tls;
1564                 app.tls_id = tls_cnt = 1;
1565 #ifdef TLS_ABOVE_TP
1566                 app.tls.offset = 0;
1567                 tls_offset = app.tls.size
1568                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1569                         & (app.tls.align-1) );
1570 #else
1571                 tls_offset = app.tls.offset = app.tls.size
1572                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1573                         & (app.tls.align-1) );
1574 #endif
1575                 tls_align = MAXP2(tls_align, app.tls.align);
1576         }
1577         decode_dyn(&app);
1578         if (DL_FDPIC) {
1579                 makefuncdescs(&app);
1580                 if (!app.loadmap) {
1581                         app.loadmap = (void *)&app_dummy_loadmap;
1582                         app.loadmap->nsegs = 1;
1583                         app.loadmap->segs[0].addr = (size_t)app.map;
1584                         app.loadmap->segs[0].p_vaddr = (size_t)app.map
1585                                 - (size_t)app.base;
1586                         app.loadmap->segs[0].p_memsz = app.map_len;
1587                 }
1588                 argv[-3] = (void *)app.loadmap;
1589         }
1590
1591         /* Initial dso chain consists only of the app. */
1592         head = tail = syms_tail = &app;
1593
1594         /* Donate unused parts of app and library mapping to malloc */
1595         reclaim_gaps(&app);
1596         reclaim_gaps(&ldso);
1597
1598         /* Load preload/needed libraries, add symbols to global namespace. */
1599         if (env_preload) load_preload(env_preload);
1600         load_deps(&app);
1601         for (struct dso *p=head; p; p=p->next)
1602                 add_syms(p);
1603
1604         /* Attach to vdso, if provided by the kernel, last so that it does
1605          * not become part of the global namespace.  */
1606         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
1607                 Ehdr *ehdr = (void *)vdso_base;
1608                 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1609                 vdso.phnum = ehdr->e_phnum;
1610                 vdso.phentsize = ehdr->e_phentsize;
1611                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1612                         if (phdr->p_type == PT_DYNAMIC)
1613                                 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1614                         if (phdr->p_type == PT_LOAD)
1615                                 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1616                 }
1617                 vdso.name = "";
1618                 vdso.shortname = "linux-gate.so.1";
1619                 vdso.relocated = 1;
1620                 decode_dyn(&vdso);
1621                 vdso.prev = tail;
1622                 tail->next = &vdso;
1623                 tail = &vdso;
1624         }
1625
1626         for (i=0; app.dynv[i]; i+=2) {
1627                 if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
1628                         app.dynv[i+1] = (size_t)&debug;
1629                 if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
1630                         size_t *ptr = (size_t *) app.dynv[i+1];
1631                         *ptr = (size_t)&debug;
1632                 }
1633         }
1634
1635         /* The main program must be relocated LAST since it may contin
1636          * copy relocations which depend on libraries' relocations. */
1637         reloc_all(app.next);
1638         reloc_all(&app);
1639
1640         update_tls_size();
1641         if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1642                 void *initial_tls = calloc(libc.tls_size, 1);
1643                 if (!initial_tls) {
1644                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1645                                 argv[0], libc.tls_size);
1646                         _exit(127);
1647                 }
1648                 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1649                         a_crash();
1650                 }
1651         } else {
1652                 size_t tmp_tls_size = libc.tls_size;
1653                 pthread_t self = __pthread_self();
1654                 /* Temporarily set the tls size to the full size of
1655                  * builtin_tls so that __copy_tls will use the same layout
1656                  * as it did for before. Then check, just to be safe. */
1657                 libc.tls_size = sizeof builtin_tls;
1658                 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1659                 libc.tls_size = tmp_tls_size;
1660         }
1661         static_tls_cnt = tls_cnt;
1662
1663         if (ldso_fail) _exit(127);
1664         if (ldd_mode) _exit(0);
1665
1666         /* Switch to runtime mode: any further failures in the dynamic
1667          * linker are a reportable failure rather than a fatal startup
1668          * error. */
1669         runtime = 1;
1670
1671         debug.ver = 1;
1672         debug.bp = dl_debug_state;
1673         debug.head = head;
1674         debug.base = ldso.base;
1675         debug.state = 0;
1676         _dl_debug_state();
1677
1678         errno = 0;
1679
1680         CRTJMP((void *)aux[AT_ENTRY], argv-1);
1681         for(;;);
1682 }
1683
1684 static void prepare_lazy(struct dso *p)
1685 {
1686         size_t dyn[DYN_CNT], n, flags1=0;
1687         decode_vec(p->dynv, dyn, DYN_CNT);
1688         search_vec(p->dynv, &flags1, DT_FLAGS_1);
1689         if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
1690                 return;
1691         n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
1692         if (NEED_MIPS_GOT_RELOCS) {
1693                 size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1694                 size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1695                 n += i-j;
1696         }
1697         p->lazy = calloc(n, 3*sizeof(size_t));
1698         if (!p->lazy) {
1699                 error("Error preparing lazy relocation for %s: %m", p->name);
1700                 longjmp(*rtld_fail, 1);
1701         }
1702         p->lazy_next = lazy_head;
1703         lazy_head = p;
1704 }
1705
1706 void *dlopen(const char *file, int mode)
1707 {
1708         struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
1709         struct tls_module *orig_tls_tail;
1710         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1711         size_t i;
1712         int cs;
1713         jmp_buf jb;
1714
1715         if (!file) return head;
1716
1717         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1718         pthread_rwlock_wrlock(&lock);
1719         __inhibit_ptc();
1720
1721         p = 0;
1722         orig_tls_tail = tls_tail;
1723         orig_tls_cnt = tls_cnt;
1724         orig_tls_offset = tls_offset;
1725         orig_tls_align = tls_align;
1726         orig_lazy_head = lazy_head;
1727         orig_syms_tail = syms_tail;
1728         orig_tail = tail;
1729         noload = mode & RTLD_NOLOAD;
1730
1731         rtld_fail = &jb;
1732         if (setjmp(*rtld_fail)) {
1733                 /* Clean up anything new that was (partially) loaded */
1734                 revert_syms(orig_syms_tail);
1735                 for (p=orig_tail->next; p; p=next) {
1736                         next = p->next;
1737                         while (p->td_index) {
1738                                 void *tmp = p->td_index->next;
1739                                 free(p->td_index);
1740                                 p->td_index = tmp;
1741                         }
1742                         free(p->funcdescs);
1743                         if (p->rpath != p->rpath_orig)
1744                                 free(p->rpath);
1745                         free(p->deps);
1746                         unmap_library(p);
1747                         free(p);
1748                 }
1749                 if (!orig_tls_tail) libc.tls_head = 0;
1750                 tls_tail = orig_tls_tail;
1751                 if (tls_tail) tls_tail->next = 0;
1752                 tls_cnt = orig_tls_cnt;
1753                 tls_offset = orig_tls_offset;
1754                 tls_align = orig_tls_align;
1755                 lazy_head = orig_lazy_head;
1756                 tail = orig_tail;
1757                 tail->next = 0;
1758                 p = 0;
1759                 goto end;
1760         } else p = load_library(file, head);
1761
1762         if (!p) {
1763                 error(noload ?
1764                         "Library %s is not already loaded" :
1765                         "Error loading shared library %s: %m",
1766                         file);
1767                 goto end;
1768         }
1769
1770         /* First load handling */
1771         if (!p->deps) {
1772                 load_deps(p);
1773                 if (!p->relocated && (mode & RTLD_LAZY)) {
1774                         prepare_lazy(p);
1775                         if (p->deps) for (i=0; p->deps[i]; i++)
1776                                 if (!p->deps[i]->relocated)
1777                                         prepare_lazy(p->deps[i]);
1778                 }
1779                 /* Make new symbols global, at least temporarily, so we can do
1780                  * relocations. If not RTLD_GLOBAL, this is reverted below. */
1781                 add_syms(p);
1782                 if (p->deps) for (i=0; p->deps[i]; i++)
1783                         add_syms(p->deps[i]);
1784                 reloc_all(p);
1785         }
1786
1787         /* If RTLD_GLOBAL was not specified, undo any new additions
1788          * to the global symbol table. This is a nop if the library was
1789          * previously loaded and already global. */
1790         if (!(mode & RTLD_GLOBAL))
1791                 revert_syms(orig_syms_tail);
1792
1793         /* Processing of deferred lazy relocations must not happen until
1794          * the new libraries are committed; otherwise we could end up with
1795          * relocations resolved to symbol definitions that get removed. */
1796         redo_lazy_relocs();
1797
1798         update_tls_size();
1799         _dl_debug_state();
1800         orig_tail = tail;
1801 end:
1802         __release_ptc();
1803         if (p) gencnt++;
1804         pthread_rwlock_unlock(&lock);
1805         if (p) do_init_fini(orig_tail);
1806         pthread_setcancelstate(cs, 0);
1807         return p;
1808 }
1809
1810 __attribute__((__visibility__("hidden")))
1811 int __dl_invalid_handle(void *h)
1812 {
1813         struct dso *p;
1814         for (p=head; p; p=p->next) if (h==p) return 0;
1815         error("Invalid library handle %p", (void *)h);
1816         return 1;
1817 }
1818
1819 static void *addr2dso(size_t a)
1820 {
1821         struct dso *p;
1822         size_t i;
1823         if (DL_FDPIC) for (p=head; p; p=p->next) {
1824                 i = count_syms(p);
1825                 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
1826                         return p;
1827         }
1828         for (p=head; p; p=p->next) {
1829                 if (DL_FDPIC && p->loadmap) {
1830                         for (i=0; i<p->loadmap->nsegs; i++) {
1831                                 if (a-p->loadmap->segs[i].p_vaddr
1832                                     < p->loadmap->segs[i].p_memsz)
1833                                         return p;
1834                         }
1835                 } else {
1836                         if (a-(size_t)p->map < p->map_len)
1837                                 return p;
1838                 }
1839         }
1840         return 0;
1841 }
1842
1843 void *__tls_get_addr(tls_mod_off_t *);
1844
1845 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1846 {
1847         size_t i;
1848         uint32_t h = 0, gh = 0, *ght;
1849         Sym *sym;
1850         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1851                 if (p == RTLD_DEFAULT) {
1852                         p = head;
1853                 } else if (p == RTLD_NEXT) {
1854                         p = addr2dso((size_t)ra);
1855                         if (!p) p=head;
1856                         p = p->next;
1857                 }
1858                 struct symdef def = find_sym(p, s, 0);
1859                 if (!def.sym) goto failed;
1860                 if ((def.sym->st_info&0xf) == STT_TLS)
1861                         return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value});
1862                 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
1863                         return def.dso->funcdescs + (def.sym - def.dso->syms);
1864                 return laddr(def.dso, def.sym->st_value);
1865         }
1866         if (__dl_invalid_handle(p))
1867                 return 0;
1868         if ((ght = p->ghashtab)) {
1869                 gh = gnu_hash(s);
1870                 sym = gnu_lookup(gh, ght, p, s);
1871         } else {
1872                 h = sysv_hash(s);
1873                 sym = sysv_lookup(s, h, p);
1874         }
1875         if (sym && (sym->st_info&0xf) == STT_TLS)
1876                 return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value});
1877         if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1878                 return p->funcdescs + (sym - p->syms);
1879         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1880                 return laddr(p, sym->st_value);
1881         if (p->deps) for (i=0; p->deps[i]; i++) {
1882                 if ((ght = p->deps[i]->ghashtab)) {
1883                         if (!gh) gh = gnu_hash(s);
1884                         sym = gnu_lookup(gh, ght, p->deps[i], s);
1885                 } else {
1886                         if (!h) h = sysv_hash(s);
1887                         sym = sysv_lookup(s, h, p->deps[i]);
1888                 }
1889                 if (sym && (sym->st_info&0xf) == STT_TLS)
1890                         return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value});
1891                 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1892                         return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
1893                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1894                         return laddr(p->deps[i], sym->st_value);
1895         }
1896 failed:
1897         error("Symbol not found: %s", s);
1898         return 0;
1899 }
1900
1901 int dladdr(const void *addr, Dl_info *info)
1902 {
1903         struct dso *p;
1904         Sym *sym, *bestsym;
1905         uint32_t nsym;
1906         char *strings;
1907         void *best = 0;
1908
1909         pthread_rwlock_rdlock(&lock);
1910         p = addr2dso((size_t)addr);
1911         pthread_rwlock_unlock(&lock);
1912
1913         if (!p) return 0;
1914
1915         sym = p->syms;
1916         strings = p->strings;
1917         nsym = count_syms(p);
1918
1919         if (DL_FDPIC) {
1920                 size_t idx = ((size_t)addr-(size_t)p->funcdescs)
1921                         / sizeof(*p->funcdescs);
1922                 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
1923                         best = p->funcdescs + idx;
1924                         bestsym = sym + idx;
1925                 }
1926         }
1927
1928         if (!best) for (; nsym; nsym--, sym++) {
1929                 if (sym->st_value
1930                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1931                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1932                         void *symaddr = laddr(p, sym->st_value);
1933                         if (symaddr > addr || symaddr < best)
1934                                 continue;
1935                         best = symaddr;
1936                         bestsym = sym;
1937                         if (addr == symaddr)
1938                                 break;
1939                 }
1940         }
1941
1942         if (!best) return 0;
1943
1944         if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
1945                 best = p->funcdescs + (bestsym - p->syms);
1946
1947         info->dli_fname = p->name;
1948         info->dli_fbase = p->base;
1949         info->dli_sname = strings + bestsym->st_name;
1950         info->dli_saddr = best;
1951
1952         return 1;
1953 }
1954
1955 __attribute__((__visibility__("hidden")))
1956 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1957 {
1958         void *res;
1959         pthread_rwlock_rdlock(&lock);
1960         res = do_dlsym(p, s, ra);
1961         pthread_rwlock_unlock(&lock);
1962         return res;
1963 }
1964
1965 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1966 {
1967         struct dso *current;
1968         struct dl_phdr_info info;
1969         int ret = 0;
1970         for(current = head; current;) {
1971                 info.dlpi_addr      = (uintptr_t)current->base;
1972                 info.dlpi_name      = current->name;
1973                 info.dlpi_phdr      = current->phdr;
1974                 info.dlpi_phnum     = current->phnum;
1975                 info.dlpi_adds      = gencnt;
1976                 info.dlpi_subs      = 0;
1977                 info.dlpi_tls_modid = current->tls_id;
1978                 info.dlpi_tls_data  = current->tls.image;
1979
1980                 ret = (callback)(&info, sizeof (info), data);
1981
1982                 if (ret != 0) break;
1983
1984                 pthread_rwlock_rdlock(&lock);
1985                 current = current->next;
1986                 pthread_rwlock_unlock(&lock);
1987         }
1988         return ret;
1989 }
1990
1991 __attribute__((__visibility__("hidden")))
1992 void __dl_vseterr(const char *, va_list);
1993
1994 static void error(const char *fmt, ...)
1995 {
1996         va_list ap;
1997         va_start(ap, fmt);
1998         if (!runtime) {
1999                 vdprintf(2, fmt, ap);
2000                 dprintf(2, "\n");
2001                 ldso_fail = 1;
2002                 va_end(ap);
2003                 return;
2004         }
2005         __dl_vseterr(fmt, ap);
2006         va_end(ap);
2007 }