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

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <stdarg.h>
   5 #include <stddef.h>
   6 #include <string.h>
   7 #include <unistd.h>
   8 #include <stdint.h>
   9 #include <elf.h>
  10 #include <sys/mman.h>
  11 #include <limits.h>
  12 #include <fcntl.h>
  13 #include <sys/stat.h>
  14 #include <errno.h>
  15 #include <link.h>
  16 #include <setjmp.h>
  17 #include <pthread.h>
  18 #include <ctype.h>
  19 #include <dlfcn.h>
  20 #include "pthread_impl.h"
  21 #include "libc.h"
  22 #include "dynlink.h"
  23 #include "malloc_impl.h"
  24
  25 static void error(const char *, ...);
  26
  27 #define MAXP2(a,b) (-(-(a)&-(b)))
  28 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  29
  30 struct debug {
  31         int ver;
  32         void *head;
  33         void (*bp)(void);
  34         int state;
  35         void *base;
  36 };
  37
  38 struct td_index {
  39         size_t args[2];
  40         struct td_index *next;
  41 };
  42
  43 struct dso {
  44 #if DL_FDPIC
  45         struct fdpic_loadmap *loadmap;
  46 #else
  47         unsigned char *base;
  48 #endif
  49         char *name;
  50         size_t *dynv;
  51         struct dso *next, *prev;
  52
  53         Phdr *phdr;
  54         int phnum;
  55         size_t phentsize;
  56         Sym *syms;
  57         Elf_Symndx *hashtab;
  58         uint32_t *ghashtab;
  59         int16_t *versym;
  60         char *strings;
  61         struct dso *syms_next, *lazy_next;
  62         size_t *lazy, lazy_cnt;
  63         unsigned char *map;
  64         size_t map_len;
  65         dev_t dev;
  66         ino_t ino;
  67         char relocated;
  68         char constructed;
  69         char kernel_mapped;
  70         struct dso **deps, *needed_by;
  71         char *rpath_orig, *rpath;
  72         struct tls_module tls;
  73         size_t tls_id;
  74         size_t relro_start, relro_end;
  75         void **new_dtv;
  76         unsigned char *new_tls;
  77         volatile int new_dtv_idx, new_tls_idx;
  78         struct td_index *td_index;
  79         struct dso *fini_next;
  80         char *shortname;
  81 #if DL_FDPIC
  82         unsigned char *base;
  83 #else
  84         struct fdpic_loadmap *loadmap;
  85 #endif
  86         struct funcdesc {
  87                 void *addr;
  88                 size_t *got;
  89         } *funcdescs;
  90         size_t *got;
  91         char buf[];
  92 };
  93
  94 struct symdef {
  95         Sym *sym;
  96         struct dso *dso;
  97 };
  98
  99 int __init_tp(void *);
 100 void __init_libc(char **, char *);
 101 void *__copy_tls(unsigned char *);
 102
 103 static struct builtin_tls {
 104         char c;
 105         struct pthread pt;
 106         void *space[16];
 107 } builtin_tls[1];
 108 #define MIN_TLS_ALIGN offsetof(struct builtin_tls, pt)
 109
 110 #define ADDEND_LIMIT 4096
 111 static size_t *saved_addends, *apply_addends_to;
 112
 113 static struct dso ldso;
 114 static struct dso *head, *tail, *fini_head, *syms_tail, *lazy_head;
 115 static char *env_path, *sys_path;
 116 static unsigned long long gencnt;
 117 static int runtime;
 118 static int ldd_mode;
 119 static int ldso_fail;
 120 static int noload;
 121 static jmp_buf *rtld_fail;
 122 static pthread_rwlock_t lock;
 123 static struct debug debug;
 124 static struct tls_module *tls_tail;
 125 static size_t tls_cnt, tls_offset, tls_align = MIN_TLS_ALIGN;
 126 static size_t static_tls_cnt;
 127 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 128 static struct fdpic_loadmap *app_loadmap;
 129 static struct fdpic_dummy_loadmap app_dummy_loadmap;
 130 static struct dso *const nodeps_dummy;
 131
 132 struct debug *_dl_debug_addr = &debug;
 133
 134 extern hidden int __malloc_replaced;
 135
 136 hidden void (*const __init_array_start)(void)=0, (*const __fini_array_start)(void)=0;
 137
 138 extern hidden void (*const __init_array_end)(void), (*const __fini_array_end)(void);
 139
 140 weak_alias(__init_array_start, __init_array_end);
 141 weak_alias(__fini_array_start, __fini_array_end);
 142
 143 static int dl_strcmp(const char *l, const char *r)
 144 {
 145         for (; *l==*r && *l; l++, r++);
 146         return *(unsigned char *)l - *(unsigned char *)r;
 147 }
 148 #define strcmp(l,r) dl_strcmp(l,r)
 149
 150 /* Compute load address for a virtual address in a given dso. */
 151 #if DL_FDPIC
 152 static void *laddr(const struct dso *p, size_t v)
 153 {
 154         size_t j=0;
 155         if (!p->loadmap) return p->base + v;
 156         for (j=0; v-p->loadmap->segs[j].p_vaddr >= p->loadmap->segs[j].p_memsz; j++);
 157         return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
 158 }
 159 static void *laddr_pg(const struct dso *p, size_t v)
 160 {
 161         size_t j=0;
 162         size_t pgsz = PAGE_SIZE;
 163         if (!p->loadmap) return p->base + v;
 164         for (j=0; ; j++) {
 165                 size_t a = p->loadmap->segs[j].p_vaddr;
 166                 size_t b = a + p->loadmap->segs[j].p_memsz;
 167                 a &= -pgsz;
 168                 b += pgsz-1;
 169                 b &= -pgsz;
 170                 if (v-a<b-a) break;
 171         }
 172         return (void *)(v - p->loadmap->segs[j].p_vaddr + p->loadmap->segs[j].addr);
 173 }
 174 #define fpaddr(p, v) ((void (*)())&(struct funcdesc){ \
 175         laddr(p, v), (p)->got })
 176 #else
 177 #define laddr(p, v) (void *)((p)->base + (v))
 178 #define laddr_pg(p, v) laddr(p, v)
 179 #define fpaddr(p, v) ((void (*)())laddr(p, v))
 180 #endif
 181
 182 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 183 {
 184         size_t i;
 185         for (i=0; i<cnt; i++) a[i] = 0;
 186         for (; v[0]; v+=2) if (v[0]-1<cnt-1) {
 187                 a[0] |= 1UL<<v[0];
 188                 a[v[0]] = v[1];
 189         }
 190 }
 191
 192 static int search_vec(size_t *v, size_t *r, size_t key)
 193 {
 194         for (; v[0]!=key; v+=2)
 195                 if (!v[0]) return 0;
 196         *r = v[1];
 197         return 1;
 198 }
 199
 200 static uint32_t sysv_hash(const char *s0)
 201 {
 202         const unsigned char *s = (void *)s0;
 203         uint_fast32_t h = 0;
 204         while (*s) {
 205                 h = 16*h + *s++;
 206                 h ^= h>>24 & 0xf0;
 207         }
 208         return h & 0xfffffff;
 209 }
 210
 211 static uint32_t gnu_hash(const char *s0)
 212 {
 213         const unsigned char *s = (void *)s0;
 214         uint_fast32_t h = 5381;
 215         for (; *s; s++)
 216                 h += h*32 + *s;
 217         return h;
 218 }
 219
 220 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 221 {
 222         size_t i;
 223         Sym *syms = dso->syms;
 224         Elf_Symndx *hashtab = dso->hashtab;
 225         char *strings = dso->strings;
 226         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 227                 if ((!dso->versym || dso->versym[i] >= 0)
 228                     && (!strcmp(s, strings+syms[i].st_name)))
 229                         return syms+i;
 230         }
 231         return 0;
 232 }
 233
 234 static Sym *gnu_lookup(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s)
 235 {
 236         uint32_t nbuckets = hashtab[0];
 237         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 238         uint32_t i = buckets[h1 % nbuckets];
 239
 240         if (!i) return 0;
 241
 242         uint32_t *hashval = buckets + nbuckets + (i - hashtab[1]);
 243
 244         for (h1 |= 1; ; i++) {
 245                 uint32_t h2 = *hashval++;
 246                 if ((h1 == (h2|1)) && (!dso->versym || dso->versym[i] >= 0)
 247                     && !strcmp(s, dso->strings + dso->syms[i].st_name))
 248                         return dso->syms+i;
 249                 if (h2 & 1) break;
 250         }
 251
 252         return 0;
 253 }
 254
 255 static Sym *gnu_lookup_filtered(uint32_t h1, uint32_t *hashtab, struct dso *dso, const char *s, uint32_t fofs, size_t fmask)
 256 {
 257         const size_t *bloomwords = (const void *)(hashtab+4);
 258         size_t f = bloomwords[fofs & (hashtab[2]-1)];
 259         if (!(f & fmask)) return 0;
 260
 261         f >>= (h1 >> hashtab[3]) % (8 * sizeof f);
 262         if (!(f & 1)) return 0;
 263
 264         return gnu_lookup(h1, hashtab, dso, s);
 265 }
 266
 267 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 268 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 269
 270 #ifndef ARCH_SYM_REJECT_UND
 271 #define ARCH_SYM_REJECT_UND(s) 0
 272 #endif
 273
 274 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 275 {
 276         uint32_t h = 0, gh = gnu_hash(s), gho = gh / (8*sizeof(size_t)), *ght;
 277         size_t ghm = 1ul << gh % (8*sizeof(size_t));
 278         struct symdef def = {0};
 279         for (; dso; dso=dso->syms_next) {
 280                 Sym *sym;
 281                 if ((ght = dso->ghashtab)) {
 282                         sym = gnu_lookup_filtered(gh, ght, dso, s, gho, ghm);
 283                 } else {
 284                         if (!h) h = sysv_hash(s);
 285                         sym = sysv_lookup(s, h, dso);
 286                 }
 287                 if (!sym) continue;
 288                 if (!sym->st_shndx)
 289                         if (need_def || (sym->st_info&0xf) == STT_TLS
 290                             || ARCH_SYM_REJECT_UND(sym))
 291                                 continue;
 292                 if (!sym->st_value)
 293                         if ((sym->st_info&0xf) != STT_TLS)
 294                                 continue;
 295                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 296                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 297                 def.sym = sym;
 298                 def.dso = dso;
 299                 break;
 300         }
 301         return def;
 302 }
 303
 304 hidden ptrdiff_t __tlsdesc_static(), __tlsdesc_dynamic();
 305
 306 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 307 {
 308         unsigned char *base = dso->base;
 309         Sym *syms = dso->syms;
 310         char *strings = dso->strings;
 311         Sym *sym;
 312         const char *name;
 313         void *ctx;
 314         int type;
 315         int sym_index;
 316         struct symdef def;
 317         size_t *reloc_addr;
 318         size_t sym_val;
 319         size_t tls_val;
 320         size_t addend;
 321         int skip_relative = 0, reuse_addends = 0, save_slot = 0;
 322
 323         if (dso == &ldso) {
 324                 /* Only ldso's REL table needs addend saving/reuse. */
 325                 if (rel == apply_addends_to)
 326                         reuse_addends = 1;
 327                 skip_relative = 1;
 328         }
 329
 330         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 331                 if (skip_relative && IS_RELATIVE(rel[1], dso->syms)) continue;
 332                 type = R_TYPE(rel[1]);
 333                 if (type == REL_NONE) continue;
 334                 reloc_addr = laddr(dso, rel[0]);
 335
 336                 if (stride > 2) {
 337                         addend = rel[2];
 338                 } else if (type==REL_GOT || type==REL_PLT|| type==REL_COPY) {
 339                         addend = 0;
 340                 } else if (reuse_addends) {
 341                         /* Save original addend in stage 2 where the dso
 342                          * chain consists of just ldso; otherwise read back
 343                          * saved addend since the inline one was clobbered. */
 344                         if (head==&ldso)
 345                                 saved_addends[save_slot] = *reloc_addr;
 346                         addend = saved_addends[save_slot++];
 347                 } else {
 348                         addend = *reloc_addr;
 349                 }
 350
 351                 sym_index = R_SYM(rel[1]);
 352                 if (sym_index) {
 353                         sym = syms + sym_index;
 354                         name = strings + sym->st_name;
 355                         ctx = type==REL_COPY ? head->syms_next : head;
 356                         def = (sym->st_info&0xf) == STT_SECTION
 357                                 ? (struct symdef){ .dso = dso, .sym = sym }
 358                                 : find_sym(ctx, name, type==REL_PLT);
 359                         if (!def.sym && (sym->st_shndx != SHN_UNDEF
 360                             || sym->st_info>>4 != STB_WEAK)) {
 361                                 if (dso->lazy && (type==REL_PLT || type==REL_GOT)) {
 362                                         dso->lazy[3*dso->lazy_cnt+0] = rel[0];
 363                                         dso->lazy[3*dso->lazy_cnt+1] = rel[1];
 364                                         dso->lazy[3*dso->lazy_cnt+2] = addend;
 365                                         dso->lazy_cnt++;
 366                                         continue;
 367                                 }
 368                                 error("Error relocating %s: %s: symbol not found",
 369                                         dso->name, name);
 370                                 if (runtime) longjmp(*rtld_fail, 1);
 371                                 continue;
 372                         }
 373                 } else {
 374                         sym = 0;
 375                         def.sym = 0;
 376                         def.dso = dso;
 377                 }
 378
 379                 sym_val = def.sym ? (size_t)laddr(def.dso, def.sym->st_value) : 0;
 380                 tls_val = def.sym ? def.sym->st_value : 0;
 381
 382                 if ((type == REL_TPOFF || type == REL_TPOFF_NEG)
 383                     && runtime && def.dso->tls_id > static_tls_cnt) {
 384                         error("Error relocating %s: %s: initial-exec TLS "
 385                                 "resolves to dynamic definition in %s",
 386                                 dso->name, name, def.dso->name);
 387                         longjmp(*rtld_fail, 1);
 388                 }
 389
 390                 switch(type) {
 391                 case REL_NONE:
 392                         break;
 393                 case REL_OFFSET:
 394                         addend -= (size_t)reloc_addr;
 395                 case REL_SYMBOLIC:
 396                 case REL_GOT:
 397                 case REL_PLT:
 398                         *reloc_addr = sym_val + addend;
 399                         break;
 400                 case REL_RELATIVE:
 401                         *reloc_addr = (size_t)base + addend;
 402                         break;
 403                 case REL_SYM_OR_REL:
 404                         if (sym) *reloc_addr = sym_val + addend;
 405                         else *reloc_addr = (size_t)base + addend;
 406                         break;
 407                 case REL_COPY:
 408                         memcpy(reloc_addr, (void *)sym_val, sym->st_size);
 409                         break;
 410                 case REL_OFFSET32:
 411                         *(uint32_t *)reloc_addr = sym_val + addend
 412                                 - (size_t)reloc_addr;
 413                         break;
 414                 case REL_FUNCDESC:
 415                         *reloc_addr = def.sym ? (size_t)(def.dso->funcdescs
 416                                 + (def.sym - def.dso->syms)) : 0;
 417                         break;
 418                 case REL_FUNCDESC_VAL:
 419                         if ((sym->st_info&0xf) == STT_SECTION) *reloc_addr += sym_val;
 420                         else *reloc_addr = sym_val;
 421                         reloc_addr[1] = def.sym ? (size_t)def.dso->got : 0;
 422                         break;
 423                 case REL_DTPMOD:
 424                         *reloc_addr = def.dso->tls_id;
 425                         break;
 426                 case REL_DTPOFF:
 427                         *reloc_addr = tls_val + addend - DTP_OFFSET;
 428                         break;
 429 #ifdef TLS_ABOVE_TP
 430                 case REL_TPOFF:
 431                         *reloc_addr = tls_val + def.dso->tls.offset + TPOFF_K + addend;
 432                         break;
 433 #else
 434                 case REL_TPOFF:
 435                         *reloc_addr = tls_val - def.dso->tls.offset + addend;
 436                         break;
 437                 case REL_TPOFF_NEG:
 438                         *reloc_addr = def.dso->tls.offset - tls_val + addend;
 439                         break;
 440 #endif
 441                 case REL_TLSDESC:
 442                         if (stride<3) addend = reloc_addr[1];
 443                         if (runtime && def.dso->tls_id > static_tls_cnt) {
 444                                 struct td_index *new = malloc(sizeof *new);
 445                                 if (!new) {
 446                                         error(
 447                                         "Error relocating %s: cannot allocate TLSDESC for %s",
 448                                         dso->name, sym ? name : "(local)" );
 449                                         longjmp(*rtld_fail, 1);
 450                                 }
 451                                 new->next = dso->td_index;
 452                                 dso->td_index = new;
 453                                 new->args[0] = def.dso->tls_id;
 454                                 new->args[1] = tls_val + addend;
 455                                 reloc_addr[0] = (size_t)__tlsdesc_dynamic;
 456                                 reloc_addr[1] = (size_t)new;
 457                         } else {
 458                                 reloc_addr[0] = (size_t)__tlsdesc_static;
 459 #ifdef TLS_ABOVE_TP
 460                                 reloc_addr[1] = tls_val + def.dso->tls.offset
 461                                         + TPOFF_K + addend;
 462 #else
 463                                 reloc_addr[1] = tls_val - def.dso->tls.offset
 464                                         + addend;
 465 #endif
 466                         }
 467                         break;
 468                 default:
 469                         error("Error relocating %s: unsupported relocation type %d",
 470                                 dso->name, type);
 471                         if (runtime) longjmp(*rtld_fail, 1);
 472                         continue;
 473                 }
 474         }
 475 }
 476
 477 static void redo_lazy_relocs()
 478 {
 479         struct dso *p = lazy_head, *next;
 480         lazy_head = 0;
 481         for (; p; p=next) {
 482                 next = p->lazy_next;
 483                 size_t size = p->lazy_cnt*3*sizeof(size_t);
 484                 p->lazy_cnt = 0;
 485                 do_relocs(p, p->lazy, size, 3);
 486                 if (p->lazy_cnt) {
 487                         p->lazy_next = lazy_head;
 488                         lazy_head = p;
 489                 } else {
 490                         free(p->lazy);
 491                         p->lazy = 0;
 492                         p->lazy_next = 0;
 493                 }
 494         }
 495 }
 496
 497 /* A huge hack: to make up for the wastefulness of shared libraries
 498  * needing at least a page of dirty memory even if they have no global
 499  * data, we reclaim the gaps at the beginning and end of writable maps
 500  * and "donate" them to the heap. */
 501
 502 static void reclaim(struct dso *dso, size_t start, size_t end)
 503 {
 504         if (start >= dso->relro_start && start < dso->relro_end) start = dso->relro_end;
 505         if (end   >= dso->relro_start && end   < dso->relro_end) end = dso->relro_start;
 506         if (start >= end) return;
 507         char *base = laddr_pg(dso, start);
 508         __malloc_donate(base, base+(end-start));
 509 }
 510
 511 static void reclaim_gaps(struct dso *dso)
 512 {
 513         Phdr *ph = dso->phdr;
 514         size_t phcnt = dso->phnum;
 515
 516         for (; phcnt--; ph=(void *)((char *)ph+dso->phentsize)) {
 517                 if (ph->p_type!=PT_LOAD) continue;
 518                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 519                 reclaim(dso, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 520                 reclaim(dso, ph->p_vaddr+ph->p_memsz,
 521                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 522         }
 523 }
 524
 525 static void *mmap_fixed(void *p, size_t n, int prot, int flags, int fd, off_t off)
 526 {
 527         static int no_map_fixed;
 528         char *q;
 529         if (!no_map_fixed) {
 530                 q = mmap(p, n, prot, flags|MAP_FIXED, fd, off);
 531                 if (!DL_NOMMU_SUPPORT || q != MAP_FAILED || errno != EINVAL)
 532                         return q;
 533                 no_map_fixed = 1;
 534         }
 535         /* Fallbacks for MAP_FIXED failure on NOMMU kernels. */
 536         if (flags & MAP_ANONYMOUS) {
 537                 memset(p, 0, n);
 538                 return p;
 539         }
 540         ssize_t r;
 541         if (lseek(fd, off, SEEK_SET) < 0) return MAP_FAILED;
 542         for (q=p; n; q+=r, off+=r, n-=r) {
 543                 r = read(fd, q, n);
 544                 if (r < 0 && errno != EINTR) return MAP_FAILED;
 545                 if (!r) {
 546                         memset(q, 0, n);
 547                         break;
 548                 }
 549         }
 550         return p;
 551 }
 552
 553 static void unmap_library(struct dso *dso)
 554 {
 555         if (dso->loadmap) {
 556                 size_t i;
 557                 for (i=0; i<dso->loadmap->nsegs; i++) {
 558                         if (!dso->loadmap->segs[i].p_memsz)
 559                                 continue;
 560                         munmap((void *)dso->loadmap->segs[i].addr,
 561                                 dso->loadmap->segs[i].p_memsz);
 562                 }
 563                 free(dso->loadmap);
 564         } else if (dso->map && dso->map_len) {
 565                 munmap(dso->map, dso->map_len);
 566         }
 567 }
 568
 569 static void *map_library(int fd, struct dso *dso)
 570 {
 571         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 572         void *allocated_buf=0;
 573         size_t phsize;
 574         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 575         size_t this_min, this_max;
 576         size_t nsegs = 0;
 577         off_t off_start;
 578         Ehdr *eh;
 579         Phdr *ph, *ph0;
 580         unsigned prot;
 581         unsigned char *map=MAP_FAILED, *base;
 582         size_t dyn=0;
 583         size_t tls_image=0;
 584         size_t i;
 585
 586         ssize_t l = read(fd, buf, sizeof buf);
 587         eh = buf;
 588         if (l<0) return 0;
 589         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 590                 goto noexec;
 591         phsize = eh->e_phentsize * eh->e_phnum;
 592         if (phsize > sizeof buf - sizeof *eh) {
 593                 allocated_buf = malloc(phsize);
 594                 if (!allocated_buf) return 0;
 595                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 596                 if (l < 0) goto error;
 597                 if (l != phsize) goto noexec;
 598                 ph = ph0 = allocated_buf;
 599         } else if (eh->e_phoff + phsize > l) {
 600                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 601                 if (l < 0) goto error;
 602                 if (l != phsize) goto noexec;
 603                 ph = ph0 = (void *)(buf + 1);
 604         } else {
 605                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 606         }
 607         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 608                 if (ph->p_type == PT_DYNAMIC) {
 609                         dyn = ph->p_vaddr;
 610                 } else if (ph->p_type == PT_TLS) {
 611                         tls_image = ph->p_vaddr;
 612                         dso->tls.align = ph->p_align;
 613                         dso->tls.len = ph->p_filesz;
 614                         dso->tls.size = ph->p_memsz;
 615                 } else if (ph->p_type == PT_GNU_RELRO) {
 616                         dso->relro_start = ph->p_vaddr & -PAGE_SIZE;
 617                         dso->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
 618                 }
 619                 if (ph->p_type != PT_LOAD) continue;
 620                 nsegs++;
 621                 if (ph->p_vaddr < addr_min) {
 622                         addr_min = ph->p_vaddr;
 623                         off_start = ph->p_offset;
 624                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 625                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 626                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 627                 }
 628                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 629                         addr_max = ph->p_vaddr+ph->p_memsz;
 630                 }
 631         }
 632         if (!dyn) goto noexec;
 633         if (DL_FDPIC && !(eh->e_flags & FDPIC_CONSTDISP_FLAG)) {
 634                 dso->loadmap = calloc(1, sizeof *dso->loadmap
 635                         + nsegs * sizeof *dso->loadmap->segs);
 636                 if (!dso->loadmap) goto error;
 637                 dso->loadmap->nsegs = nsegs;
 638                 for (ph=ph0, i=0; i<nsegs; ph=(void *)((char *)ph+eh->e_phentsize)) {
 639                         if (ph->p_type != PT_LOAD) continue;
 640                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 641                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 642                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 643                         map = mmap(0, ph->p_memsz + (ph->p_vaddr & PAGE_SIZE-1),
 644                                 prot, MAP_PRIVATE,
 645                                 fd, ph->p_offset & -PAGE_SIZE);
 646                         if (map == MAP_FAILED) {
 647                                 unmap_library(dso);
 648                                 goto error;
 649                         }
 650                         dso->loadmap->segs[i].addr = (size_t)map +
 651                                 (ph->p_vaddr & PAGE_SIZE-1);
 652                         dso->loadmap->segs[i].p_vaddr = ph->p_vaddr;
 653                         dso->loadmap->segs[i].p_memsz = ph->p_memsz;
 654                         i++;
 655                         if (prot & PROT_WRITE) {
 656                                 size_t brk = (ph->p_vaddr & PAGE_SIZE-1)
 657                                         + ph->p_filesz;
 658                                 size_t pgbrk = brk + PAGE_SIZE-1 & -PAGE_SIZE;
 659                                 size_t pgend = brk + ph->p_memsz - ph->p_filesz
 660                                         + PAGE_SIZE-1 & -PAGE_SIZE;
 661                                 if (pgend > pgbrk && mmap_fixed(map+pgbrk,
 662                                         pgend-pgbrk, prot,
 663                                         MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS,
 664                                         -1, off_start) == MAP_FAILED)
 665                                         goto error;
 666                                 memset(map + brk, 0, pgbrk-brk);
 667                         }
 668                 }
 669                 map = (void *)dso->loadmap->segs[0].addr;
 670                 map_len = 0;
 671                 goto done_mapping;
 672         }
 673         addr_max += PAGE_SIZE-1;
 674         addr_max &= -PAGE_SIZE;
 675         addr_min &= -PAGE_SIZE;
 676         off_start &= -PAGE_SIZE;
 677         map_len = addr_max - addr_min + off_start;
 678         /* The first time, we map too much, possibly even more than
 679          * the length of the file. This is okay because we will not
 680          * use the invalid part; we just need to reserve the right
 681          * amount of virtual address space to map over later. */
 682         map = DL_NOMMU_SUPPORT
 683                 ? mmap((void *)addr_min, map_len, PROT_READ|PROT_WRITE|PROT_EXEC,
 684                         MAP_PRIVATE|MAP_ANONYMOUS, -1, 0)
 685                 : mmap((void *)addr_min, map_len, prot,
 686                         MAP_PRIVATE, fd, off_start);
 687         if (map==MAP_FAILED) goto error;
 688         dso->map = map;
 689         dso->map_len = map_len;
 690         /* If the loaded file is not relocatable and the requested address is
 691          * not available, then the load operation must fail. */
 692         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 693                 errno = EBUSY;
 694                 goto error;
 695         }
 696         base = map - addr_min;
 697         dso->phdr = 0;
 698         dso->phnum = 0;
 699         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 700                 if (ph->p_type != PT_LOAD) continue;
 701                 /* Check if the programs headers are in this load segment, and
 702                  * if so, record the address for use by dl_iterate_phdr. */
 703                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 704                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 705                         dso->phdr = (void *)(base + ph->p_vaddr
 706                                 + (eh->e_phoff-ph->p_offset));
 707                         dso->phnum = eh->e_phnum;
 708                         dso->phentsize = eh->e_phentsize;
 709                 }
 710                 this_min = ph->p_vaddr & -PAGE_SIZE;
 711                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 712                 off_start = ph->p_offset & -PAGE_SIZE;
 713                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 714                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 715                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 716                 /* Reuse the existing mapping for the lowest-address LOAD */
 717                 if ((ph->p_vaddr & -PAGE_SIZE) != addr_min || DL_NOMMU_SUPPORT)
 718                         if (mmap_fixed(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 719                                 goto error;
 720                 if (ph->p_memsz > ph->p_filesz && (ph->p_flags&PF_W)) {
 721                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 722                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 723                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 724                         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)
 725                                 goto error;
 726                 }
 727         }
 728         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 729                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 730                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC)
 731                             && errno != ENOSYS)
 732                                 goto error;
 733                         break;
 734                 }
 735 done_mapping:
 736         dso->base = base;
 737         dso->dynv = laddr(dso, dyn);
 738         if (dso->tls.size) dso->tls.image = laddr(dso, tls_image);
 739         free(allocated_buf);
 740         return map;
 741 noexec:
 742         errno = ENOEXEC;
 743 error:
 744         if (map!=MAP_FAILED) unmap_library(dso);
 745         free(allocated_buf);
 746         return 0;
 747 }
 748
 749 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 750 {
 751         size_t l;
 752         int fd;
 753         for (;;) {
 754                 s += strspn(s, ":\n");
 755                 l = strcspn(s, ":\n");
 756                 if (l-1 >= INT_MAX) return -1;
 757                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) < buf_size) {
 758                         if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 759                         switch (errno) {
 760                         case ENOENT:
 761                         case ENOTDIR:
 762                         case EACCES:
 763                         case ENAMETOOLONG:
 764                                 break;
 765                         default:
 766                                 /* Any negative value but -1 will inhibit
 767                                  * futher path search. */
 768                                 return -2;
 769                         }
 770                 }
 771                 s += l;
 772         }
 773 }
 774
 775 static int fixup_rpath(struct dso *p, char *buf, size_t buf_size)
 776 {
 777         size_t n, l;
 778         const char *s, *t, *origin;
 779         char *d;
 780         if (p->rpath || !p->rpath_orig) return 0;
 781         if (!strchr(p->rpath_orig, '$')) {
 782                 p->rpath = p->rpath_orig;
 783                 return 0;
 784         }
 785         n = 0;
 786         s = p->rpath_orig;
 787         while ((t=strchr(s, '$'))) {
 788                 if (strncmp(t, "$ORIGIN", 7) && strncmp(t, "${ORIGIN}", 9))
 789                         return 0;
 790                 s = t+1;
 791                 n++;
 792         }
 793         if (n > SSIZE_MAX/PATH_MAX) return 0;
 794
 795         if (p->kernel_mapped) {
 796                 /* $ORIGIN searches cannot be performed for the main program
 797                  * when it is suid/sgid/AT_SECURE. This is because the
 798                  * pathname is under the control of the caller of execve.
 799                  * For libraries, however, $ORIGIN can be processed safely
 800                  * since the library's pathname came from a trusted source
 801                  * (either system paths or a call to dlopen). */
 802                 if (libc.secure)
 803                         return 0;
 804                 l = readlink("/proc/self/exe", buf, buf_size);
 805                 if (l == -1) switch (errno) {
 806                 case ENOENT:
 807                 case ENOTDIR:
 808                 case EACCES:
 809                         break;
 810                 default:
 811                         return -1;
 812                 }
 813                 if (l >= buf_size)
 814                         return 0;
 815                 buf[l] = 0;
 816                 origin = buf;
 817         } else {
 818                 origin = p->name;
 819         }
 820         t = strrchr(origin, '/');
 821         if (t) {
 822                 l = t-origin;
 823         } else {
 824                 /* Normally p->name will always be an absolute or relative
 825                  * pathname containing at least one '/' character, but in the
 826                  * case where ldso was invoked as a command to execute a
 827                  * program in the working directory, app.name may not. Fix. */
 828                 origin = ".";
 829                 l = 1;
 830         }
 831         /* Disallow non-absolute origins for suid/sgid/AT_SECURE. */
 832         if (libc.secure && *origin != '/')
 833                 return 0;
 834         p->rpath = malloc(strlen(p->rpath_orig) + n*l + 1);
 835         if (!p->rpath) return -1;
 836
 837         d = p->rpath;
 838         s = p->rpath_orig;
 839         while ((t=strchr(s, '$'))) {
 840                 memcpy(d, s, t-s);
 841                 d += t-s;
 842                 memcpy(d, origin, l);
 843                 d += l;
 844                 /* It was determined previously that the '$' is followed
 845                  * either by "ORIGIN" or "{ORIGIN}". */
 846                 s = t + 7 + 2*(t[1]=='{');
 847         }
 848         strcpy(d, s);
 849         return 0;
 850 }
 851
 852 static void decode_dyn(struct dso *p)
 853 {
 854         size_t dyn[DYN_CNT];
 855         decode_vec(p->dynv, dyn, DYN_CNT);
 856         p->syms = laddr(p, dyn[DT_SYMTAB]);
 857         p->strings = laddr(p, dyn[DT_STRTAB]);
 858         if (dyn[0]&(1<<DT_HASH))
 859                 p->hashtab = laddr(p, dyn[DT_HASH]);
 860         if (dyn[0]&(1<<DT_RPATH))
 861                 p->rpath_orig = p->strings + dyn[DT_RPATH];
 862         if (dyn[0]&(1<<DT_RUNPATH))
 863                 p->rpath_orig = p->strings + dyn[DT_RUNPATH];
 864         if (dyn[0]&(1<<DT_PLTGOT))
 865                 p->got = laddr(p, dyn[DT_PLTGOT]);
 866         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 867                 p->ghashtab = laddr(p, *dyn);
 868         if (search_vec(p->dynv, dyn, DT_VERSYM))
 869                 p->versym = laddr(p, *dyn);
 870 }
 871
 872 static size_t count_syms(struct dso *p)
 873 {
 874         if (p->hashtab) return p->hashtab[1];
 875
 876         size_t nsym, i;
 877         uint32_t *buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
 878         uint32_t *hashval;
 879         for (i = nsym = 0; i < p->ghashtab[0]; i++) {
 880                 if (buckets[i] > nsym)
 881                         nsym = buckets[i];
 882         }
 883         if (nsym) {
 884                 hashval = buckets + p->ghashtab[0] + (nsym - p->ghashtab[1]);
 885                 do nsym++;
 886                 while (!(*hashval++ & 1));
 887         }
 888         return nsym;
 889 }
 890
 891 static void *dl_mmap(size_t n)
 892 {
 893         void *p;
 894         int prot = PROT_READ|PROT_WRITE, flags = MAP_ANONYMOUS|MAP_PRIVATE;
 895 #ifdef SYS_mmap2
 896         p = (void *)__syscall(SYS_mmap2, 0, n, prot, flags, -1, 0);
 897 #else
 898         p = (void *)__syscall(SYS_mmap, 0, n, prot, flags, -1, 0);
 899 #endif
 900         return p == MAP_FAILED ? 0 : p;
 901 }
 902
 903 static void makefuncdescs(struct dso *p)
 904 {
 905         static int self_done;
 906         size_t nsym = count_syms(p);
 907         size_t i, size = nsym * sizeof(*p->funcdescs);
 908
 909         if (!self_done) {
 910                 p->funcdescs = dl_mmap(size);
 911                 self_done = 1;
 912         } else {
 913                 p->funcdescs = malloc(size);
 914         }
 915         if (!p->funcdescs) {
 916                 if (!runtime) a_crash();
 917                 error("Error allocating function descriptors for %s", p->name);
 918                 longjmp(*rtld_fail, 1);
 919         }
 920         for (i=0; i<nsym; i++) {
 921                 if ((p->syms[i].st_info&0xf)==STT_FUNC && p->syms[i].st_shndx) {
 922                         p->funcdescs[i].addr = laddr(p, p->syms[i].st_value);
 923                         p->funcdescs[i].got = p->got;
 924                 } else {
 925                         p->funcdescs[i].addr = 0;
 926                         p->funcdescs[i].got = 0;
 927                 }
 928         }
 929 }
 930
 931 static struct dso *load_library(const char *name, struct dso *needed_by)
 932 {
 933         char buf[2*NAME_MAX+2];
 934         const char *pathname;
 935         unsigned char *map;
 936         struct dso *p, temp_dso = {0};
 937         int fd;
 938         struct stat st;
 939         size_t alloc_size;
 940         int n_th = 0;
 941         int is_self = 0;
 942
 943         if (!*name) {
 944                 errno = EINVAL;
 945                 return 0;
 946         }
 947
 948         /* Catch and block attempts to reload the implementation itself */
 949         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 950                 static const char reserved[] =
 951                         "c.pthread.rt.m.dl.util.xnet.";
 952                 const char *rp, *next;
 953                 for (rp=reserved; *rp; rp=next) {
 954                         next = strchr(rp, '.') + 1;
 955                         if (strncmp(name+3, rp, next-rp) == 0)
 956                                 break;
 957                 }
 958                 if (*rp) {
 959                         if (ldd_mode) {
 960                                 /* Track which names have been resolved
 961                                  * and only report each one once. */
 962                                 static unsigned reported;
 963                                 unsigned mask = 1U<<(rp-reserved);
 964                                 if (!(reported & mask)) {
 965                                         reported |= mask;
 966                                         dprintf(1, "\t%s => %s (%p)\n",
 967                                                 name, ldso.name,
 968                                                 ldso.base);
 969                                 }
 970                         }
 971                         is_self = 1;
 972                 }
 973         }
 974         if (!strcmp(name, ldso.name)) is_self = 1;
 975         if (is_self) {
 976                 if (!ldso.prev) {
 977                         tail->next = &ldso;
 978                         ldso.prev = tail;
 979                         tail = &ldso;
 980                 }
 981                 return &ldso;
 982         }
 983         if (strchr(name, '/')) {
 984                 pathname = name;
 985                 fd = open(name, O_RDONLY|O_CLOEXEC);
 986         } else {
 987                 /* Search for the name to see if it's already loaded */
 988                 for (p=head->next; p; p=p->next) {
 989                         if (p->shortname && !strcmp(p->shortname, name)) {
 990                                 return p;
 991                         }
 992                 }
 993                 if (strlen(name) > NAME_MAX) return 0;
 994                 fd = -1;
 995                 if (env_path) fd = path_open(name, env_path, buf, sizeof buf);
 996                 for (p=needed_by; fd == -1 && p; p=p->needed_by) {
 997                         if (fixup_rpath(p, buf, sizeof buf) < 0)
 998                                 fd = -2; /* Inhibit further search. */
 999                         if (p->rpath)
1000                                 fd = path_open(name, p->rpath, buf, sizeof buf);
1001                 }
1002                 if (fd == -1) {
1003                         if (!sys_path) {
1004                                 char *prefix = 0;
1005                                 size_t prefix_len;
1006                                 if (ldso.name[0]=='/') {
1007                                         char *s, *t, *z;
1008                                         for (s=t=z=ldso.name; *s; s++)
1009                                                 if (*s=='/') z=t, t=s;
1010                                         prefix_len = z-ldso.name;
1011                                         if (prefix_len < PATH_MAX)
1012                                                 prefix = ldso.name;
1013                                 }
1014                                 if (!prefix) {
1015                                         prefix = "";
1016                                         prefix_len = 0;
1017                                 }
1018                                 char etc_ldso_path[prefix_len + 1
1019                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
1020                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
1021                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
1022                                         (int)prefix_len, prefix);
1023                                 FILE *f = fopen(etc_ldso_path, "rbe");
1024                                 if (f) {
1025                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
1026                                                 free(sys_path);
1027                                                 sys_path = "";
1028                                         }
1029                                         fclose(f);
1030                                 } else if (errno != ENOENT) {
1031                                         sys_path = "";
1032                                 }
1033                         }
1034                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
1035                         fd = path_open(name, sys_path, buf, sizeof buf);
1036                 }
1037                 pathname = buf;
1038         }
1039         if (fd < 0) return 0;
1040         if (fstat(fd, &st) < 0) {
1041                 close(fd);
1042                 return 0;
1043         }
1044         for (p=head->next; p; p=p->next) {
1045                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
1046                         /* If this library was previously loaded with a
1047                          * pathname but a search found the same inode,
1048                          * setup its shortname so it can be found by name. */
1049                         if (!p->shortname && pathname != name)
1050                                 p->shortname = strrchr(p->name, '/')+1;
1051                         close(fd);
1052                         return p;
1053                 }
1054         }
1055         map = noload ? 0 : map_library(fd, &temp_dso);
1056         close(fd);
1057         if (!map) return 0;
1058
1059         /* Avoid the danger of getting two versions of libc mapped into the
1060          * same process when an absolute pathname was used. The symbols
1061          * checked are chosen to catch both musl and glibc, and to avoid
1062          * false positives from interposition-hack libraries. */
1063         decode_dyn(&temp_dso);
1064         if (find_sym(&temp_dso, "__libc_start_main", 1).sym &&
1065             find_sym(&temp_dso, "stdin", 1).sym) {
1066                 unmap_library(&temp_dso);
1067                 return load_library("libc.so", needed_by);
1068         }
1069         /* Past this point, if we haven't reached runtime yet, ldso has
1070          * committed either to use the mapped library or to abort execution.
1071          * Unmapping is not possible, so we can safely reclaim gaps. */
1072         if (!runtime) reclaim_gaps(&temp_dso);
1073
1074         /* Allocate storage for the new DSO. When there is TLS, this
1075          * storage must include a reservation for all pre-existing
1076          * threads to obtain copies of both the new TLS, and an
1077          * extended DTV capable of storing an additional slot for
1078          * the newly-loaded DSO. */
1079         alloc_size = sizeof *p + strlen(pathname) + 1;
1080         if (runtime && temp_dso.tls.image) {
1081                 size_t per_th = temp_dso.tls.size + temp_dso.tls.align
1082                         + sizeof(void *) * (tls_cnt+3);
1083                 n_th = libc.threads_minus_1 + 1;
1084                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
1085                 else alloc_size += n_th * per_th;
1086         }
1087         p = calloc(1, alloc_size);
1088         if (!p) {
1089                 unmap_library(&temp_dso);
1090                 return 0;
1091         }
1092         memcpy(p, &temp_dso, sizeof temp_dso);
1093         p->dev = st.st_dev;
1094         p->ino = st.st_ino;
1095         p->needed_by = needed_by;
1096         p->name = p->buf;
1097         strcpy(p->name, pathname);
1098         /* Add a shortname only if name arg was not an explicit pathname. */
1099         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
1100         if (p->tls.image) {
1101                 p->tls_id = ++tls_cnt;
1102                 tls_align = MAXP2(tls_align, p->tls.align);
1103 #ifdef TLS_ABOVE_TP
1104                 p->tls.offset = tls_offset + ( (tls_align-1) &
1105                         -(tls_offset + (uintptr_t)p->tls.image) );
1106                 tls_offset += p->tls.size;
1107 #else
1108                 tls_offset += p->tls.size + p->tls.align - 1;
1109                 tls_offset -= (tls_offset + (uintptr_t)p->tls.image)
1110                         & (p->tls.align-1);
1111                 p->tls.offset = tls_offset;
1112 #endif
1113                 p->new_dtv = (void *)(-sizeof(size_t) &
1114                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
1115                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
1116                 if (tls_tail) tls_tail->next = &p->tls;
1117                 else libc.tls_head = &p->tls;
1118                 tls_tail = &p->tls;
1119         }
1120
1121         tail->next = p;
1122         p->prev = tail;
1123         tail = p;
1124
1125         if (DL_FDPIC) makefuncdescs(p);
1126
1127         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
1128
1129         return p;
1130 }
1131
1132 static void load_deps(struct dso *p)
1133 {
1134         size_t i, ndeps=0;
1135         struct dso ***deps = &p->deps, **tmp, *dep;
1136         for (; p; p=p->next) {
1137                 for (i=0; p->dynv[i]; i+=2) {
1138                         if (p->dynv[i] != DT_NEEDED) continue;
1139                         dep = load_library(p->strings + p->dynv[i+1], p);
1140                         if (!dep) {
1141                                 error("Error loading shared library %s: %m (needed by %s)",
1142                                         p->strings + p->dynv[i+1], p->name);
1143                                 if (runtime) longjmp(*rtld_fail, 1);
1144                                 continue;
1145                         }
1146                         if (runtime) {
1147                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
1148                                 if (!tmp) longjmp(*rtld_fail, 1);
1149                                 tmp[ndeps++] = dep;
1150                                 tmp[ndeps] = 0;
1151                                 *deps = tmp;
1152                         }
1153                 }
1154         }
1155         if (!*deps) *deps = (struct dso **)&nodeps_dummy;
1156 }
1157
1158 static void load_preload(char *s)
1159 {
1160         int tmp;
1161         char *z;
1162         for (z=s; *z; s=z) {
1163                 for (   ; *s && (isspace(*s) || *s==':'); s++);
1164                 for (z=s; *z && !isspace(*z) && *z!=':'; z++);
1165                 tmp = *z;
1166                 *z = 0;
1167                 load_library(s, 0);
1168                 *z = tmp;
1169         }
1170 }
1171
1172 static void add_syms(struct dso *p)
1173 {
1174         if (!p->syms_next && syms_tail != p) {
1175                 syms_tail->syms_next = p;
1176                 syms_tail = p;
1177         }
1178 }
1179
1180 static void revert_syms(struct dso *old_tail)
1181 {
1182         struct dso *p, *next;
1183         /* Chop off the tail of the list of dsos that participate in
1184          * the global symbol table, reverting them to RTLD_LOCAL. */
1185         for (p=old_tail; p; p=next) {
1186                 next = p->syms_next;
1187                 p->syms_next = 0;
1188         }
1189         syms_tail = old_tail;
1190 }
1191
1192 static void do_mips_relocs(struct dso *p, size_t *got)
1193 {
1194         size_t i, j, rel[2];
1195         unsigned char *base = p->base;
1196         i=0; search_vec(p->dynv, &i, DT_MIPS_LOCAL_GOTNO);
1197         if (p==&ldso) {
1198                 got += i;
1199         } else {
1200                 while (i--) *got++ += (size_t)base;
1201         }
1202         j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1203         i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1204         Sym *sym = p->syms + j;
1205         rel[0] = (unsigned char *)got - base;
1206         for (i-=j; i; i--, sym++, rel[0]+=sizeof(size_t)) {
1207                 rel[1] = R_INFO(sym-p->syms, R_MIPS_JUMP_SLOT);
1208                 do_relocs(p, rel, sizeof rel, 2);
1209         }
1210 }
1211
1212 static void reloc_all(struct dso *p)
1213 {
1214         size_t dyn[DYN_CNT];
1215         for (; p; p=p->next) {
1216                 if (p->relocated) continue;
1217                 decode_vec(p->dynv, dyn, DYN_CNT);
1218                 if (NEED_MIPS_GOT_RELOCS)
1219                         do_mips_relocs(p, laddr(p, dyn[DT_PLTGOT]));
1220                 do_relocs(p, laddr(p, dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
1221                         2+(dyn[DT_PLTREL]==DT_RELA));
1222                 do_relocs(p, laddr(p, dyn[DT_REL]), dyn[DT_RELSZ], 2);
1223                 do_relocs(p, laddr(p, dyn[DT_RELA]), dyn[DT_RELASZ], 3);
1224
1225                 if (head != &ldso && p->relro_start != p->relro_end &&
1226                     mprotect(laddr(p, p->relro_start), p->relro_end-p->relro_start, PROT_READ)
1227                     && errno != ENOSYS) {
1228                         error("Error relocating %s: RELRO protection failed: %m",
1229                                 p->name);
1230                         if (runtime) longjmp(*rtld_fail, 1);
1231                 }
1232
1233                 p->relocated = 1;
1234         }
1235 }
1236
1237 static void kernel_mapped_dso(struct dso *p)
1238 {
1239         size_t min_addr = -1, max_addr = 0, cnt;
1240         Phdr *ph = p->phdr;
1241         for (cnt = p->phnum; cnt--; ph = (void *)((char *)ph + p->phentsize)) {
1242                 if (ph->p_type == PT_DYNAMIC) {
1243                         p->dynv = laddr(p, ph->p_vaddr);
1244                 } else if (ph->p_type == PT_GNU_RELRO) {
1245                         p->relro_start = ph->p_vaddr & -PAGE_SIZE;
1246                         p->relro_end = (ph->p_vaddr + ph->p_memsz) & -PAGE_SIZE;
1247                 }
1248                 if (ph->p_type != PT_LOAD) continue;
1249                 if (ph->p_vaddr < min_addr)
1250                         min_addr = ph->p_vaddr;
1251                 if (ph->p_vaddr+ph->p_memsz > max_addr)
1252                         max_addr = ph->p_vaddr+ph->p_memsz;
1253         }
1254         min_addr &= -PAGE_SIZE;
1255         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
1256         p->map = p->base + min_addr;
1257         p->map_len = max_addr - min_addr;
1258         p->kernel_mapped = 1;
1259 }
1260
1261 void __libc_exit_fini()
1262 {
1263         struct dso *p;
1264         size_t dyn[DYN_CNT];
1265         for (p=fini_head; p; p=p->fini_next) {
1266                 if (!p->constructed) continue;
1267                 decode_vec(p->dynv, dyn, DYN_CNT);
1268                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
1269                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
1270                         size_t *fn = (size_t *)laddr(p, dyn[DT_FINI_ARRAY])+n;
1271                         while (n--) ((void (*)(void))*--fn)();
1272                 }
1273 #ifndef NO_LEGACY_INITFINI
1274                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
1275                         fpaddr(p, dyn[DT_FINI])();
1276 #endif
1277         }
1278 }
1279
1280 static void do_init_fini(struct dso *p)
1281 {
1282         size_t dyn[DYN_CNT];
1283         int need_locking = libc.threads_minus_1;
1284         /* Allow recursive calls that arise when a library calls
1285          * dlopen from one of its constructors, but block any
1286          * other threads until all ctors have finished. */
1287         if (need_locking) pthread_mutex_lock(&init_fini_lock);
1288         for (; p; p=p->prev) {
1289                 if (p->constructed) continue;
1290                 p->constructed = 1;
1291                 decode_vec(p->dynv, dyn, DYN_CNT);
1292                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
1293                         p->fini_next = fini_head;
1294                         fini_head = p;
1295                 }
1296 #ifndef NO_LEGACY_INITFINI
1297                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
1298                         fpaddr(p, dyn[DT_INIT])();
1299 #endif
1300                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
1301                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
1302                         size_t *fn = laddr(p, dyn[DT_INIT_ARRAY]);
1303                         while (n--) ((void (*)(void))*fn++)();
1304                 }
1305                 if (!need_locking && libc.threads_minus_1) {
1306                         need_locking = 1;
1307                         pthread_mutex_lock(&init_fini_lock);
1308                 }
1309         }
1310         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
1311 }
1312
1313 void __libc_start_init(void)
1314 {
1315         do_init_fini(tail);
1316 }
1317
1318 static void dl_debug_state(void)
1319 {
1320 }
1321
1322 weak_alias(dl_debug_state, _dl_debug_state);
1323
1324 void __init_tls(size_t *auxv)
1325 {
1326 }
1327
1328 hidden void *__tls_get_new(tls_mod_off_t *v)
1329 {
1330         pthread_t self = __pthread_self();
1331
1332         /* Block signals to make accessing new TLS async-signal-safe */
1333         sigset_t set;
1334         __block_all_sigs(&set);
1335         if (v[0]<=(size_t)self->dtv[0]) {
1336                 __restore_sigs(&set);
1337                 return (char *)self->dtv[v[0]]+v[1]+DTP_OFFSET;
1338         }
1339
1340         /* This is safe without any locks held because, if the caller
1341          * is able to request the Nth entry of the DTV, the DSO list
1342          * must be valid at least that far out and it was synchronized
1343          * at program startup or by an already-completed call to dlopen. */
1344         struct dso *p;
1345         for (p=head; p->tls_id != v[0]; p=p->next);
1346
1347         /* Get new DTV space from new DSO if needed */
1348         if (v[0] > (size_t)self->dtv[0]) {
1349                 void **newdtv = p->new_dtv +
1350                         (v[0]+1)*a_fetch_add(&p->new_dtv_idx,1);
1351                 memcpy(newdtv, self->dtv,
1352                         ((size_t)self->dtv[0]+1) * sizeof(void *));
1353                 newdtv[0] = (void *)v[0];
1354                 self->dtv = self->dtv_copy = newdtv;
1355         }
1356
1357         /* Get new TLS memory from all new DSOs up to the requested one */
1358         unsigned char *mem;
1359         for (p=head; ; p=p->next) {
1360                 if (!p->tls_id || self->dtv[p->tls_id]) continue;
1361                 mem = p->new_tls + (p->tls.size + p->tls.align)
1362                         * a_fetch_add(&p->new_tls_idx,1);
1363                 mem += ((uintptr_t)p->tls.image - (uintptr_t)mem)
1364                         & (p->tls.align-1);
1365                 self->dtv[p->tls_id] = mem;
1366                 memcpy(mem, p->tls.image, p->tls.len);
1367                 if (p->tls_id == v[0]) break;
1368         }
1369         __restore_sigs(&set);
1370         return mem + v[1] + DTP_OFFSET;
1371 }
1372
1373 static void update_tls_size()
1374 {
1375         libc.tls_cnt = tls_cnt;
1376         libc.tls_align = tls_align;
1377         libc.tls_size = ALIGN(
1378                 (1+tls_cnt) * sizeof(void *) +
1379                 tls_offset +
1380                 sizeof(struct pthread) +
1381                 tls_align * 2,
1382         tls_align);
1383 }
1384
1385 /* Stage 1 of the dynamic linker is defined in dlstart.c. It calls the
1386  * following stage 2 and stage 3 functions via primitive symbolic lookup
1387  * since it does not have access to their addresses to begin with. */
1388
1389 /* Stage 2 of the dynamic linker is called after relative relocations
1390  * have been processed. It can make function calls to static functions
1391  * and access string literals and static data, but cannot use extern
1392  * symbols. Its job is to perform symbolic relocations on the dynamic
1393  * linker itself, but some of the relocations performed may need to be
1394  * replaced later due to copy relocations in the main program. */
1395
1396 hidden void __dls2(unsigned char *base, size_t *sp)
1397 {
1398         if (DL_FDPIC) {
1399                 void *p1 = (void *)sp[-2];
1400                 void *p2 = (void *)sp[-1];
1401                 if (!p1) {
1402                         size_t *auxv, aux[AUX_CNT];
1403                         for (auxv=sp+1+*sp+1; *auxv; auxv++); auxv++;
1404                         decode_vec(auxv, aux, AUX_CNT);
1405                         if (aux[AT_BASE]) ldso.base = (void *)aux[AT_BASE];
1406                         else ldso.base = (void *)(aux[AT_PHDR] & -4096);
1407                 }
1408                 app_loadmap = p2 ? p1 : 0;
1409                 ldso.loadmap = p2 ? p2 : p1;
1410                 ldso.base = laddr(&ldso, 0);
1411         } else {
1412                 ldso.base = base;
1413         }
1414         Ehdr *ehdr = (void *)ldso.base;
1415         ldso.name = ldso.shortname = "libc.so";
1416         ldso.phnum = ehdr->e_phnum;
1417         ldso.phdr = laddr(&ldso, ehdr->e_phoff);
1418         ldso.phentsize = ehdr->e_phentsize;
1419         kernel_mapped_dso(&ldso);
1420         decode_dyn(&ldso);
1421
1422         if (DL_FDPIC) makefuncdescs(&ldso);
1423
1424         /* Prepare storage for to save clobbered REL addends so they
1425          * can be reused in stage 3. There should be very few. If
1426          * something goes wrong and there are a huge number, abort
1427          * instead of risking stack overflow. */
1428         size_t dyn[DYN_CNT];
1429         decode_vec(ldso.dynv, dyn, DYN_CNT);
1430         size_t *rel = laddr(&ldso, dyn[DT_REL]);
1431         size_t rel_size = dyn[DT_RELSZ];
1432         size_t symbolic_rel_cnt = 0;
1433         apply_addends_to = rel;
1434         for (; rel_size; rel+=2, rel_size-=2*sizeof(size_t))
1435                 if (!IS_RELATIVE(rel[1], ldso.syms)) symbolic_rel_cnt++;
1436         if (symbolic_rel_cnt >= ADDEND_LIMIT) a_crash();
1437         size_t addends[symbolic_rel_cnt+1];
1438         saved_addends = addends;
1439
1440         head = &ldso;
1441         reloc_all(&ldso);
1442
1443         ldso.relocated = 0;
1444
1445         /* Call dynamic linker stage-3, __dls3, looking it up
1446          * symbolically as a barrier against moving the address
1447          * load across the above relocation processing. */
1448         struct symdef dls3_def = find_sym(&ldso, "__dls3", 0);
1449         if (DL_FDPIC) ((stage3_func)&ldso.funcdescs[dls3_def.sym-ldso.syms])(sp);
1450         else ((stage3_func)laddr(&ldso, dls3_def.sym->st_value))(sp);
1451 }
1452
1453 /* Stage 3 of the dynamic linker is called with the dynamic linker/libc
1454  * fully functional. Its job is to load (if not already loaded) and
1455  * process dependencies and relocations for the main application and
1456  * transfer control to its entry point. */
1457
1458 _Noreturn void __dls3(size_t *sp)
1459 {
1460         static struct dso app, vdso;
1461         size_t aux[AUX_CNT], *auxv;
1462         size_t i;
1463         char *env_preload=0;
1464         char *replace_argv0=0;
1465         size_t vdso_base;
1466         int argc = *sp;
1467         char **argv = (void *)(sp+1);
1468         char **argv_orig = argv;
1469         char **envp = argv+argc+1;
1470
1471         /* Find aux vector just past environ[] and use it to initialize
1472          * global data that may be needed before we can make syscalls. */
1473         __environ = envp;
1474         for (i=argc+1; argv[i]; i++);
1475         libc.auxv = auxv = (void *)(argv+i+1);
1476         decode_vec(auxv, aux, AUX_CNT);
1477         __hwcap = aux[AT_HWCAP];
1478         libc.page_size = aux[AT_PAGESZ];
1479         libc.secure = ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
1480                 || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]);
1481
1482         /* Setup early thread pointer in builtin_tls for ldso/libc itself to
1483          * use during dynamic linking. If possible it will also serve as the
1484          * thread pointer at runtime. */
1485         libc.tls_size = sizeof builtin_tls;
1486         libc.tls_align = tls_align;
1487         if (__init_tp(__copy_tls((void *)builtin_tls)) < 0) {
1488                 a_crash();
1489         }
1490
1491         /* Only trust user/env if kernel says we're not suid/sgid */
1492         if (!libc.secure) {
1493                 env_path = getenv("LD_LIBRARY_PATH");
1494                 env_preload = getenv("LD_PRELOAD");
1495         }
1496
1497         /* If the main program was already loaded by the kernel,
1498          * AT_PHDR will point to some location other than the dynamic
1499          * linker's program headers. */
1500         if (aux[AT_PHDR] != (size_t)ldso.phdr) {
1501                 size_t interp_off = 0;
1502                 size_t tls_image = 0;
1503                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
1504                 Phdr *phdr = app.phdr = (void *)aux[AT_PHDR];
1505                 app.phnum = aux[AT_PHNUM];
1506                 app.phentsize = aux[AT_PHENT];
1507                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
1508                         if (phdr->p_type == PT_PHDR)
1509                                 app.base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
1510                         else if (phdr->p_type == PT_INTERP)
1511                                 interp_off = (size_t)phdr->p_vaddr;
1512                         else if (phdr->p_type == PT_TLS) {
1513                                 tls_image = phdr->p_vaddr;
1514                                 app.tls.len = phdr->p_filesz;
1515                                 app.tls.size = phdr->p_memsz;
1516                                 app.tls.align = phdr->p_align;
1517                         }
1518                 }
1519                 if (DL_FDPIC) app.loadmap = app_loadmap;
1520                 if (app.tls.size) app.tls.image = laddr(&app, tls_image);
1521                 if (interp_off) ldso.name = laddr(&app, interp_off);
1522                 if ((aux[0] & (1UL<<AT_EXECFN))
1523                     && strncmp((char *)aux[AT_EXECFN], "/proc/", 6))
1524                         app.name = (char *)aux[AT_EXECFN];
1525                 else
1526                         app.name = argv[0];
1527                 kernel_mapped_dso(&app);
1528         } else {
1529                 int fd;
1530                 char *ldname = argv[0];
1531                 size_t l = strlen(ldname);
1532                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
1533                 argv++;
1534                 while (argv[0] && argv[0][0]=='-' && argv[0][1]=='-') {
1535                         char *opt = argv[0]+2;
1536                         *argv++ = (void *)-1;
1537                         if (!*opt) {
1538                                 break;
1539                         } else if (!memcmp(opt, "list", 5)) {
1540                                 ldd_mode = 1;
1541                         } else if (!memcmp(opt, "library-path", 12)) {
1542                                 if (opt[12]=='=') env_path = opt+13;
1543                                 else if (opt[12]) *argv = 0;
1544                                 else if (*argv) env_path = *argv++;
1545                         } else if (!memcmp(opt, "preload", 7)) {
1546                                 if (opt[7]=='=') env_preload = opt+8;
1547                                 else if (opt[7]) *argv = 0;
1548                                 else if (*argv) env_preload = *argv++;
1549                         } else if (!memcmp(opt, "argv0", 5)) {
1550                                 if (opt[5]=='=') replace_argv0 = opt+6;
1551                                 else if (opt[5]) *argv = 0;
1552                                 else if (*argv) replace_argv0 = *argv++;
1553                         } else {
1554                                 argv[0] = 0;
1555                         }
1556                 }
1557                 argv[-1] = (void *)(argc - (argv-argv_orig));
1558                 if (!argv[0]) {
1559                         dprintf(2, "musl libc (" LDSO_ARCH ")\n"
1560                                 "Version %s\n"
1561                                 "Dynamic Program Loader\n"
1562                                 "Usage: %s [options] [--] pathname%s\n",
1563                                 __libc_version, ldname,
1564                                 ldd_mode ? "" : " [args]");
1565                         _exit(1);
1566                 }
1567                 fd = open(argv[0], O_RDONLY);
1568                 if (fd < 0) {
1569                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
1570                         _exit(1);
1571                 }
1572                 Ehdr *ehdr = (void *)map_library(fd, &app);
1573                 if (!ehdr) {
1574                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
1575                         _exit(1);
1576                 }
1577                 close(fd);
1578                 ldso.name = ldname;
1579                 app.name = argv[0];
1580                 aux[AT_ENTRY] = (size_t)laddr(&app, ehdr->e_entry);
1581                 /* Find the name that would have been used for the dynamic
1582                  * linker had ldd not taken its place. */
1583                 if (ldd_mode) {
1584                         for (i=0; i<app.phnum; i++) {
1585                                 if (app.phdr[i].p_type == PT_INTERP)
1586                                         ldso.name = laddr(&app, app.phdr[i].p_vaddr);
1587                         }
1588                         dprintf(1, "\t%s (%p)\n", ldso.name, ldso.base);
1589                 }
1590         }
1591         if (app.tls.size) {
1592                 libc.tls_head = tls_tail = &app.tls;
1593                 app.tls_id = tls_cnt = 1;
1594 #ifdef TLS_ABOVE_TP
1595                 app.tls.offset = GAP_ABOVE_TP;
1596                 app.tls.offset += -GAP_ABOVE_TP & (app.tls.align-1);
1597                 tls_offset = app.tls.offset + app.tls.size
1598                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1599                         & (app.tls.align-1) );
1600 #else
1601                 tls_offset = app.tls.offset = app.tls.size
1602                         + ( -((uintptr_t)app.tls.image + app.tls.size)
1603                         & (app.tls.align-1) );
1604 #endif
1605                 tls_align = MAXP2(tls_align, app.tls.align);
1606         }
1607         decode_dyn(&app);
1608         if (DL_FDPIC) {
1609                 makefuncdescs(&app);
1610                 if (!app.loadmap) {
1611                         app.loadmap = (void *)&app_dummy_loadmap;
1612                         app.loadmap->nsegs = 1;
1613                         app.loadmap->segs[0].addr = (size_t)app.map;
1614                         app.loadmap->segs[0].p_vaddr = (size_t)app.map
1615                                 - (size_t)app.base;
1616                         app.loadmap->segs[0].p_memsz = app.map_len;
1617                 }
1618                 argv[-3] = (void *)app.loadmap;
1619         }
1620
1621         /* Initial dso chain consists only of the app. */
1622         head = tail = syms_tail = &app;
1623
1624         /* Donate unused parts of app and library mapping to malloc */
1625         reclaim_gaps(&app);
1626         reclaim_gaps(&ldso);
1627
1628         /* Load preload/needed libraries, add symbols to global namespace. */
1629         if (env_preload) load_preload(env_preload);
1630         load_deps(&app);
1631         for (struct dso *p=head; p; p=p->next)
1632                 add_syms(p);
1633
1634         /* Attach to vdso, if provided by the kernel, last so that it does
1635          * not become part of the global namespace.  */
1636         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR) && vdso_base) {
1637                 Ehdr *ehdr = (void *)vdso_base;
1638                 Phdr *phdr = vdso.phdr = (void *)(vdso_base + ehdr->e_phoff);
1639                 vdso.phnum = ehdr->e_phnum;
1640                 vdso.phentsize = ehdr->e_phentsize;
1641                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1642                         if (phdr->p_type == PT_DYNAMIC)
1643                                 vdso.dynv = (void *)(vdso_base + phdr->p_offset);
1644                         if (phdr->p_type == PT_LOAD)
1645                                 vdso.base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1646                 }
1647                 vdso.name = "";
1648                 vdso.shortname = "linux-gate.so.1";
1649                 vdso.relocated = 1;
1650                 decode_dyn(&vdso);
1651                 vdso.prev = tail;
1652                 tail->next = &vdso;
1653                 tail = &vdso;
1654         }
1655
1656         for (i=0; app.dynv[i]; i+=2) {
1657                 if (!DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG)
1658                         app.dynv[i+1] = (size_t)&debug;
1659                 if (DT_DEBUG_INDIRECT && app.dynv[i]==DT_DEBUG_INDIRECT) {
1660                         size_t *ptr = (size_t *) app.dynv[i+1];
1661                         *ptr = (size_t)&debug;
1662                 }
1663         }
1664
1665         /* The main program must be relocated LAST since it may contin
1666          * copy relocations which depend on libraries' relocations. */
1667         reloc_all(app.next);
1668         reloc_all(&app);
1669
1670         update_tls_size();
1671         if (libc.tls_size > sizeof builtin_tls || tls_align > MIN_TLS_ALIGN) {
1672                 void *initial_tls = calloc(libc.tls_size, 1);
1673                 if (!initial_tls) {
1674                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1675                                 argv[0], libc.tls_size);
1676                         _exit(127);
1677                 }
1678                 if (__init_tp(__copy_tls(initial_tls)) < 0) {
1679                         a_crash();
1680                 }
1681         } else {
1682                 size_t tmp_tls_size = libc.tls_size;
1683                 pthread_t self = __pthread_self();
1684                 /* Temporarily set the tls size to the full size of
1685                  * builtin_tls so that __copy_tls will use the same layout
1686                  * as it did for before. Then check, just to be safe. */
1687                 libc.tls_size = sizeof builtin_tls;
1688                 if (__copy_tls((void*)builtin_tls) != self) a_crash();
1689                 libc.tls_size = tmp_tls_size;
1690         }
1691         static_tls_cnt = tls_cnt;
1692
1693         if (ldso_fail) _exit(127);
1694         if (ldd_mode) _exit(0);
1695
1696         /* Determine if malloc was interposed by a replacement implementation
1697          * so that calloc and the memalign family can harden against the
1698          * possibility of incomplete replacement. */
1699         if (find_sym(head, "malloc", 1).dso != &ldso)
1700                 __malloc_replaced = 1;
1701
1702         /* Switch to runtime mode: any further failures in the dynamic
1703          * linker are a reportable failure rather than a fatal startup
1704          * error. */
1705         runtime = 1;
1706
1707         debug.ver = 1;
1708         debug.bp = dl_debug_state;
1709         debug.head = head;
1710         debug.base = ldso.base;
1711         debug.state = 0;
1712         _dl_debug_state();
1713
1714         if (replace_argv0) argv[0] = replace_argv0;
1715
1716         errno = 0;
1717
1718         CRTJMP((void *)aux[AT_ENTRY], argv-1);
1719         for(;;);
1720 }
1721
1722 static void prepare_lazy(struct dso *p)
1723 {
1724         size_t dyn[DYN_CNT], n, flags1=0;
1725         decode_vec(p->dynv, dyn, DYN_CNT);
1726         search_vec(p->dynv, &flags1, DT_FLAGS_1);
1727         if (dyn[DT_BIND_NOW] || (dyn[DT_FLAGS] & DF_BIND_NOW) || (flags1 & DF_1_NOW))
1728                 return;
1729         n = dyn[DT_RELSZ]/2 + dyn[DT_RELASZ]/3 + dyn[DT_PLTRELSZ]/2 + 1;
1730         if (NEED_MIPS_GOT_RELOCS) {
1731                 size_t j=0; search_vec(p->dynv, &j, DT_MIPS_GOTSYM);
1732                 size_t i=0; search_vec(p->dynv, &i, DT_MIPS_SYMTABNO);
1733                 n += i-j;
1734         }
1735         p->lazy = calloc(n, 3*sizeof(size_t));
1736         if (!p->lazy) {
1737                 error("Error preparing lazy relocation for %s: %m", p->name);
1738                 longjmp(*rtld_fail, 1);
1739         }
1740         p->lazy_next = lazy_head;
1741         lazy_head = p;
1742 }
1743
1744 void *dlopen(const char *file, int mode)
1745 {
1746         struct dso *volatile p, *orig_tail, *orig_syms_tail, *orig_lazy_head, *next;
1747         struct tls_module *orig_tls_tail;
1748         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1749         size_t i;
1750         int cs;
1751         jmp_buf jb;
1752
1753         if (!file) return head;
1754
1755         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1756         pthread_rwlock_wrlock(&lock);
1757         __inhibit_ptc();
1758
1759         p = 0;
1760         orig_tls_tail = tls_tail;
1761         orig_tls_cnt = tls_cnt;
1762         orig_tls_offset = tls_offset;
1763         orig_tls_align = tls_align;
1764         orig_lazy_head = lazy_head;
1765         orig_syms_tail = syms_tail;
1766         orig_tail = tail;
1767         noload = mode & RTLD_NOLOAD;
1768
1769         rtld_fail = &jb;
1770         if (setjmp(*rtld_fail)) {
1771                 /* Clean up anything new that was (partially) loaded */
1772                 revert_syms(orig_syms_tail);
1773                 for (p=orig_tail->next; p; p=next) {
1774                         next = p->next;
1775                         while (p->td_index) {
1776                                 void *tmp = p->td_index->next;
1777                                 free(p->td_index);
1778                                 p->td_index = tmp;
1779                         }
1780                         free(p->funcdescs);
1781                         if (p->rpath != p->rpath_orig)
1782                                 free(p->rpath);
1783                         if (p->deps != &nodeps_dummy)
1784                                 free(p->deps);
1785                         unmap_library(p);
1786                         free(p);
1787                 }
1788                 if (!orig_tls_tail) libc.tls_head = 0;
1789                 tls_tail = orig_tls_tail;
1790                 if (tls_tail) tls_tail->next = 0;
1791                 tls_cnt = orig_tls_cnt;
1792                 tls_offset = orig_tls_offset;
1793                 tls_align = orig_tls_align;
1794                 lazy_head = orig_lazy_head;
1795                 tail = orig_tail;
1796                 tail->next = 0;
1797                 p = 0;
1798                 goto end;
1799         } else p = load_library(file, head);
1800
1801         if (!p) {
1802                 error(noload ?
1803                         "Library %s is not already loaded" :
1804                         "Error loading shared library %s: %m",
1805                         file);
1806                 goto end;
1807         }
1808
1809         /* First load handling */
1810         int first_load = !p->deps;
1811         if (first_load) {
1812                 load_deps(p);
1813                 if (!p->relocated && (mode & RTLD_LAZY)) {
1814                         prepare_lazy(p);
1815                         for (i=0; p->deps[i]; i++)
1816                                 if (!p->deps[i]->relocated)
1817                                         prepare_lazy(p->deps[i]);
1818                 }
1819         }
1820         if (first_load || (mode & RTLD_GLOBAL)) {
1821                 /* Make new symbols global, at least temporarily, so we can do
1822                  * relocations. If not RTLD_GLOBAL, this is reverted below. */
1823                 add_syms(p);
1824                 for (i=0; p->deps[i]; i++)
1825                         add_syms(p->deps[i]);
1826         }
1827         if (first_load) {
1828                 reloc_all(p);
1829         }
1830
1831         /* If RTLD_GLOBAL was not specified, undo any new additions
1832          * to the global symbol table. This is a nop if the library was
1833          * previously loaded and already global. */
1834         if (!(mode & RTLD_GLOBAL))
1835                 revert_syms(orig_syms_tail);
1836
1837         /* Processing of deferred lazy relocations must not happen until
1838          * the new libraries are committed; otherwise we could end up with
1839          * relocations resolved to symbol definitions that get removed. */
1840         redo_lazy_relocs();
1841
1842         update_tls_size();
1843         _dl_debug_state();
1844         orig_tail = tail;
1845 end:
1846         __release_ptc();
1847         if (p) gencnt++;
1848         pthread_rwlock_unlock(&lock);
1849         if (p) do_init_fini(orig_tail);
1850         pthread_setcancelstate(cs, 0);
1851         return p;
1852 }
1853
1854 hidden int __dl_invalid_handle(void *h)
1855 {
1856         struct dso *p;
1857         for (p=head; p; p=p->next) if (h==p) return 0;
1858         error("Invalid library handle %p", (void *)h);
1859         return 1;
1860 }
1861
1862 static void *addr2dso(size_t a)
1863 {
1864         struct dso *p;
1865         size_t i;
1866         if (DL_FDPIC) for (p=head; p; p=p->next) {
1867                 i = count_syms(p);
1868                 if (a-(size_t)p->funcdescs < i*sizeof(*p->funcdescs))
1869                         return p;
1870         }
1871         for (p=head; p; p=p->next) {
1872                 if (DL_FDPIC && p->loadmap) {
1873                         for (i=0; i<p->loadmap->nsegs; i++) {
1874                                 if (a-p->loadmap->segs[i].p_vaddr
1875                                     < p->loadmap->segs[i].p_memsz)
1876                                         return p;
1877                         }
1878                 } else {
1879                         Phdr *ph = p->phdr;
1880                         size_t phcnt = p->phnum;
1881                         size_t entsz = p->phentsize;
1882                         size_t base = (size_t)p->base;
1883                         for (; phcnt--; ph=(void *)((char *)ph+entsz)) {
1884                                 if (ph->p_type != PT_LOAD) continue;
1885                                 if (a-base-ph->p_vaddr < ph->p_memsz)
1886                                         return p;
1887                         }
1888                         if (a-(size_t)p->map < p->map_len)
1889                                 return 0;
1890                 }
1891         }
1892         return 0;
1893 }
1894
1895 void *__tls_get_addr(tls_mod_off_t *);
1896
1897 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1898 {
1899         size_t i;
1900         uint32_t h = 0, gh = 0, *ght;
1901         Sym *sym;
1902         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1903                 if (p == RTLD_DEFAULT) {
1904                         p = head;
1905                 } else if (p == RTLD_NEXT) {
1906                         p = addr2dso((size_t)ra);
1907                         if (!p) p=head;
1908                         p = p->next;
1909                 }
1910                 struct symdef def = find_sym(p, s, 0);
1911                 if (!def.sym) goto failed;
1912                 if ((def.sym->st_info&0xf) == STT_TLS)
1913                         return __tls_get_addr((tls_mod_off_t []){def.dso->tls_id, def.sym->st_value});
1914                 if (DL_FDPIC && (def.sym->st_info&0xf) == STT_FUNC)
1915                         return def.dso->funcdescs + (def.sym - def.dso->syms);
1916                 return laddr(def.dso, def.sym->st_value);
1917         }
1918         if (__dl_invalid_handle(p))
1919                 return 0;
1920         if ((ght = p->ghashtab)) {
1921                 gh = gnu_hash(s);
1922                 sym = gnu_lookup(gh, ght, p, s);
1923         } else {
1924                 h = sysv_hash(s);
1925                 sym = sysv_lookup(s, h, p);
1926         }
1927         if (sym && (sym->st_info&0xf) == STT_TLS)
1928                 return __tls_get_addr((tls_mod_off_t []){p->tls_id, sym->st_value});
1929         if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1930                 return p->funcdescs + (sym - p->syms);
1931         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1932                 return laddr(p, sym->st_value);
1933         for (i=0; p->deps[i]; i++) {
1934                 if ((ght = p->deps[i]->ghashtab)) {
1935                         if (!gh) gh = gnu_hash(s);
1936                         sym = gnu_lookup(gh, ght, p->deps[i], s);
1937                 } else {
1938                         if (!h) h = sysv_hash(s);
1939                         sym = sysv_lookup(s, h, p->deps[i]);
1940                 }
1941                 if (sym && (sym->st_info&0xf) == STT_TLS)
1942                         return __tls_get_addr((tls_mod_off_t []){p->deps[i]->tls_id, sym->st_value});
1943                 if (DL_FDPIC && sym && sym->st_shndx && (sym->st_info&0xf) == STT_FUNC)
1944                         return p->deps[i]->funcdescs + (sym - p->deps[i]->syms);
1945                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1946                         return laddr(p->deps[i], sym->st_value);
1947         }
1948 failed:
1949         error("Symbol not found: %s", s);
1950         return 0;
1951 }
1952
1953 int dladdr(const void *addr_arg, Dl_info *info)
1954 {
1955         size_t addr = (size_t)addr_arg;
1956         struct dso *p;
1957         Sym *sym, *bestsym;
1958         uint32_t nsym;
1959         char *strings;
1960         size_t best = 0;
1961         size_t besterr = -1;
1962
1963         pthread_rwlock_rdlock(&lock);
1964         p = addr2dso(addr);
1965         pthread_rwlock_unlock(&lock);
1966
1967         if (!p) return 0;
1968
1969         sym = p->syms;
1970         strings = p->strings;
1971         nsym = count_syms(p);
1972
1973         if (DL_FDPIC) {
1974                 size_t idx = (addr-(size_t)p->funcdescs)
1975                         / sizeof(*p->funcdescs);
1976                 if (idx < nsym && (sym[idx].st_info&0xf) == STT_FUNC) {
1977                         best = (size_t)(p->funcdescs + idx);
1978                         bestsym = sym + idx;
1979                         besterr = 0;
1980                 }
1981         }
1982
1983         if (!best) for (; nsym; nsym--, sym++) {
1984                 if (sym->st_value
1985                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1986                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1987                         size_t symaddr = (size_t)laddr(p, sym->st_value);
1988                         if (symaddr > addr || symaddr <= best)
1989                                 continue;
1990                         best = symaddr;
1991                         bestsym = sym;
1992                         besterr = addr - symaddr;
1993                         if (addr == symaddr)
1994                                 break;
1995                 }
1996         }
1997
1998         if (bestsym && besterr > bestsym->st_size-1) {
1999                 best = 0;
2000                 bestsym = 0;
2001         }
2002
2003         info->dli_fname = p->name;
2004         info->dli_fbase = p->map;
2005
2006         if (!best) {
2007                 info->dli_sname = 0;
2008                 info->dli_saddr = 0;
2009                 return 1;
2010         }
2011
2012         if (DL_FDPIC && (bestsym->st_info&0xf) == STT_FUNC)
2013                 best = (size_t)(p->funcdescs + (bestsym - p->syms));
2014         info->dli_sname = strings + bestsym->st_name;
2015         info->dli_saddr = (void *)best;
2016
2017         return 1;
2018 }
2019
2020 hidden void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
2021 {
2022         void *res;
2023         pthread_rwlock_rdlock(&lock);
2024         res = do_dlsym(p, s, ra);
2025         pthread_rwlock_unlock(&lock);
2026         return res;
2027 }
2028
2029 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
2030 {
2031         struct dso *current;
2032         struct dl_phdr_info info;
2033         int ret = 0;
2034         for(current = head; current;) {
2035                 info.dlpi_addr      = (uintptr_t)current->base;
2036                 info.dlpi_name      = current->name;
2037                 info.dlpi_phdr      = current->phdr;
2038                 info.dlpi_phnum     = current->phnum;
2039                 info.dlpi_adds      = gencnt;
2040                 info.dlpi_subs      = 0;
2041                 info.dlpi_tls_modid = current->tls_id;
2042                 info.dlpi_tls_data  = current->tls.image;
2043
2044                 ret = (callback)(&info, sizeof (info), data);
2045
2046                 if (ret != 0) break;
2047
2048                 pthread_rwlock_rdlock(&lock);
2049                 current = current->next;
2050                 pthread_rwlock_unlock(&lock);
2051         }
2052         return ret;
2053 }
2054
2055 hidden void __dl_vseterr(const char *, va_list);
2056
2057 static void error(const char *fmt, ...)
2058 {
2059         va_list ap;
2060         va_start(ap, fmt);
2061         if (!runtime) {
2062                 vdprintf(2, fmt, ap);
2063                 dprintf(2, "\n");
2064                 ldso_fail = 1;
2065                 va_end(ap);
2066                 return;
2067         }
2068         __dl_vseterr(fmt, ap);
2069         va_end(ap);
2070 }