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

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