src/ldso/dynlink.c

   1 #define _GNU_SOURCE
   2 #include <stdio.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <unistd.h>
   6 #include <stdint.h>
   7 #include <elf.h>
   8 #include <sys/mman.h>
   9 #include <limits.h>
  10 #include <stdint.h>
  11 #include <fcntl.h>
  12 #include <sys/stat.h>
  13 #include <errno.h>
  14 #include <limits.h>
  15 #include <elf.h>
  16 #include <link.h>
  17 #include <setjmp.h>
  18 #include <pthread.h>
  19 #include <ctype.h>
  20 #include <dlfcn.h>
  21 #include "pthread_impl.h"
  22 #include "libc.h"
  23
  24 static int errflag;
  25 static char errbuf[128];
  26
  27 #ifdef SHARED
  28
  29 #if ULONG_MAX == 0xffffffff
  30 typedef Elf32_Ehdr Ehdr;
  31 typedef Elf32_Phdr Phdr;
  32 typedef Elf32_Sym Sym;
  33 #define R_TYPE(x) ((x)&255)
  34 #define R_SYM(x) ((x)>>8)
  35 #else
  36 typedef Elf64_Ehdr Ehdr;
  37 typedef Elf64_Phdr Phdr;
  38 typedef Elf64_Sym Sym;
  39 #define R_TYPE(x) ((x)&0xffffffff)
  40 #define R_SYM(x) ((x)>>32)
  41 #endif
  42
  43 #define MAXP2(a,b) (-(-(a)&-(b)))
  44 #define ALIGN(x,y) ((x)+(y)-1 & -(y))
  45
  46 struct debug {
  47         int ver;
  48         void *head;
  49         void (*bp)(void);
  50         int state;
  51         void *base;
  52 };
  53
  54 struct dso {
  55         unsigned char *base;
  56         char *name;
  57         size_t *dynv;
  58         struct dso *next, *prev;
  59
  60         Phdr *phdr;
  61         int phnum;
  62         int refcnt;
  63         Sym *syms;
  64         uint32_t *hashtab;
  65         uint32_t *ghashtab;
  66         char *strings;
  67         unsigned char *map;
  68         size_t map_len;
  69         dev_t dev;
  70         ino_t ino;
  71         signed char global;
  72         char relocated;
  73         char constructed;
  74         struct dso **deps;
  75         void *tls_image;
  76         size_t tls_len, tls_size, tls_align, tls_id, tls_offset;
  77         void **new_dtv;
  78         unsigned char *new_tls;
  79         int new_dtv_idx, new_tls_idx;
  80         struct dso *fini_next;
  81         char *shortname;
  82         char buf[];
  83 };
  84
  85 struct symdef {
  86         Sym *sym;
  87         struct dso *dso;
  88 };
  89
  90 #include "reloc.h"
  91
  92 void __init_ssp(size_t *);
  93 void *__install_initial_tls(void *);
  94 void __init_libc(char **, char *);
  95
  96 static struct dso *head, *tail, *ldso, *fini_head;
  97 static char *env_path, *sys_path, *r_path;
  98 static unsigned long long gencnt;
  99 static int ssp_used;
 100 static int runtime;
 101 static int ldd_mode;
 102 static int ldso_fail;
 103 static int noload;
 104 static jmp_buf *rtld_fail;
 105 static pthread_rwlock_t lock;
 106 static struct debug debug;
 107 static size_t tls_cnt, tls_offset, tls_align = 4*sizeof(size_t);
 108 static pthread_mutex_t init_fini_lock = { ._m_type = PTHREAD_MUTEX_RECURSIVE };
 109
 110 struct debug *_dl_debug_addr = &debug;
 111
 112 #define AUX_CNT 38
 113 #define DYN_CNT 34
 114
 115 static void decode_vec(size_t *v, size_t *a, size_t cnt)
 116 {
 117         memset(a, 0, cnt*sizeof(size_t));
 118         for (; v[0]; v+=2) if (v[0]<cnt) {
 119                 a[0] |= 1ULL<<v[0];
 120                 a[v[0]] = v[1];
 121         }
 122 }
 123
 124 static int search_vec(size_t *v, size_t *r, size_t key)
 125 {
 126         for (; v[0]!=key; v+=2)
 127                 if (!v[0]) return 0;
 128         *r = v[1];
 129         return 1;
 130 }
 131
 132 static uint32_t sysv_hash(const char *s0)
 133 {
 134         const unsigned char *s = (void *)s0;
 135         uint_fast32_t h = 0;
 136         while (*s) {
 137                 h = 16*h + *s++;
 138                 h ^= h>>24 & 0xf0;
 139         }
 140         return h & 0xfffffff;
 141 }
 142
 143 static uint32_t gnu_hash(const char *s0)
 144 {
 145         const unsigned char *s = (void *)s0;
 146         uint_fast32_t h = 5381;
 147         for (; *s; s++)
 148                 h = h*33 + *s;
 149         return h;
 150 }
 151
 152 static Sym *sysv_lookup(const char *s, uint32_t h, struct dso *dso)
 153 {
 154         size_t i;
 155         Sym *syms = dso->syms;
 156         uint32_t *hashtab = dso->hashtab;
 157         char *strings = dso->strings;
 158         for (i=hashtab[2+h%hashtab[0]]; i; i=hashtab[2+hashtab[0]+i]) {
 159                 if (!strcmp(s, strings+syms[i].st_name))
 160                         return syms+i;
 161         }
 162         return 0;
 163 }
 164
 165 static Sym *gnu_lookup(const char *s, uint32_t h1, struct dso *dso)
 166 {
 167         Sym *sym;
 168         char *strings;
 169         uint32_t *hashtab = dso->ghashtab;
 170         uint32_t nbuckets = hashtab[0];
 171         uint32_t *buckets = hashtab + 4 + hashtab[2]*(sizeof(size_t)/4);
 172         uint32_t h2;
 173         uint32_t *hashval;
 174         uint32_t n = buckets[h1 % nbuckets];
 175
 176         if (!n) return 0;
 177
 178         strings = dso->strings;
 179         sym = dso->syms + n;
 180         hashval = buckets + nbuckets + (n - hashtab[1]);
 181
 182         for (h1 |= 1; ; sym++) {
 183                 h2 = *hashval++;
 184                 if ((h1 == (h2|1)) && !strcmp(s, strings + sym->st_name))
 185                         return sym;
 186                 if (h2 & 1) break;
 187         }
 188
 189         return 0;
 190 }
 191
 192 #define OK_TYPES (1<<STT_NOTYPE | 1<<STT_OBJECT | 1<<STT_FUNC | 1<<STT_COMMON | 1<<STT_TLS)
 193 #define OK_BINDS (1<<STB_GLOBAL | 1<<STB_WEAK | 1<<STB_GNU_UNIQUE)
 194
 195 static struct symdef find_sym(struct dso *dso, const char *s, int need_def)
 196 {
 197         uint32_t h = 0, gh = 0;
 198         struct symdef def = {0};
 199         if (dso->ghashtab) {
 200                 gh = gnu_hash(s);
 201                 if (gh == 0x1f4039c9 && !strcmp(s, "__stack_chk_fail")) ssp_used = 1;
 202         } else {
 203                 h = sysv_hash(s);
 204                 if (h == 0x595a4cc && !strcmp(s, "__stack_chk_fail")) ssp_used = 1;
 205         }
 206         for (; dso; dso=dso->next) {
 207                 Sym *sym;
 208                 if (!dso->global) continue;
 209                 if (dso->ghashtab) {
 210                         if (!gh) gh = gnu_hash(s);
 211                         sym = gnu_lookup(s, gh, dso);
 212                 } else {
 213                         if (!h) h = sysv_hash(s);
 214                         sym = sysv_lookup(s, h, dso);
 215                 }
 216                 if (!sym) continue;
 217                 if (!sym->st_shndx)
 218                         if (need_def || (sym->st_info&0xf) == STT_TLS)
 219                                 continue;
 220                 if (!sym->st_value)
 221                         if ((sym->st_info&0xf) != STT_TLS)
 222                                 continue;
 223                 if (!(1<<(sym->st_info&0xf) & OK_TYPES)) continue;
 224                 if (!(1<<(sym->st_info>>4) & OK_BINDS)) continue;
 225
 226                 if (def.sym && sym->st_info>>4 == STB_WEAK) continue;
 227                 def.sym = sym;
 228                 def.dso = dso;
 229                 if (sym->st_info>>4 == STB_GLOBAL) break;
 230         }
 231         return def;
 232 }
 233
 234 static void do_relocs(struct dso *dso, size_t *rel, size_t rel_size, size_t stride)
 235 {
 236         unsigned char *base = dso->base;
 237         Sym *syms = dso->syms;
 238         char *strings = dso->strings;
 239         Sym *sym;
 240         const char *name;
 241         void *ctx;
 242         int type;
 243         int sym_index;
 244         struct symdef def;
 245
 246         for (; rel_size; rel+=stride, rel_size-=stride*sizeof(size_t)) {
 247                 type = R_TYPE(rel[1]);
 248                 sym_index = R_SYM(rel[1]);
 249                 if (sym_index) {
 250                         sym = syms + sym_index;
 251                         name = strings + sym->st_name;
 252                         ctx = IS_COPY(type) ? head->next : head;
 253                         def = find_sym(ctx, name, IS_PLT(type));
 254                         if (!def.sym && sym->st_info>>4 != STB_WEAK) {
 255                                 snprintf(errbuf, sizeof errbuf,
 256                                         "Error relocating %s: %s: symbol not found",
 257                                         dso->name, name);
 258                                 if (runtime) longjmp(*rtld_fail, 1);
 259                                 dprintf(2, "%s\n", errbuf);
 260                                 ldso_fail = 1;
 261                                 continue;
 262                         }
 263                 } else {
 264                         sym = 0;
 265                         def.sym = 0;
 266                         def.dso = 0;
 267                 }
 268                 do_single_reloc(dso, base, (void *)(base + rel[0]), type,
 269                         stride>2 ? rel[2] : 0, sym, sym?sym->st_size:0, def,
 270                         def.sym?(size_t)(def.dso->base+def.sym->st_value):0);
 271         }
 272 }
 273
 274 /* A huge hack: to make up for the wastefulness of shared libraries
 275  * needing at least a page of dirty memory even if they have no global
 276  * data, we reclaim the gaps at the beginning and end of writable maps
 277  * and "donate" them to the heap by setting up minimal malloc
 278  * structures and then freeing them. */
 279
 280 static void reclaim(unsigned char *base, size_t start, size_t end)
 281 {
 282         size_t *a, *z;
 283         start = start + 6*sizeof(size_t)-1 & -4*sizeof(size_t);
 284         end = (end & -4*sizeof(size_t)) - 2*sizeof(size_t);
 285         if (start>end || end-start < 4*sizeof(size_t)) return;
 286         a = (size_t *)(base + start);
 287         z = (size_t *)(base + end);
 288         a[-2] = 1;
 289         a[-1] = z[0] = end-start + 2*sizeof(size_t) | 1;
 290         z[1] = 1;
 291         free(a);
 292 }
 293
 294 static void reclaim_gaps(unsigned char *base, Phdr *ph, size_t phent, size_t phcnt)
 295 {
 296         for (; phcnt--; ph=(void *)((char *)ph+phent)) {
 297                 if (ph->p_type!=PT_LOAD) continue;
 298                 if ((ph->p_flags&(PF_R|PF_W))!=(PF_R|PF_W)) continue;
 299                 reclaim(base, ph->p_vaddr & -PAGE_SIZE, ph->p_vaddr);
 300                 reclaim(base, ph->p_vaddr+ph->p_memsz,
 301                         ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE);
 302         }
 303 }
 304
 305 static void *map_library(int fd, struct dso *dso)
 306 {
 307         Ehdr buf[(896+sizeof(Ehdr))/sizeof(Ehdr)];
 308         void *allocated_buf=0;
 309         size_t phsize;
 310         size_t addr_min=SIZE_MAX, addr_max=0, map_len;
 311         size_t this_min, this_max;
 312         off_t off_start;
 313         Ehdr *eh;
 314         Phdr *ph, *ph0;
 315         unsigned prot;
 316         unsigned char *map=MAP_FAILED, *base;
 317         size_t dyn=0;
 318         size_t tls_image=0;
 319         size_t i;
 320
 321         ssize_t l = read(fd, buf, sizeof buf);
 322         eh = buf;
 323         if (l<0) return 0;
 324         if (l<sizeof *eh || (eh->e_type != ET_DYN && eh->e_type != ET_EXEC))
 325                 goto noexec;
 326         phsize = eh->e_phentsize * eh->e_phnum;
 327         if (phsize > sizeof buf - sizeof *eh) {
 328                 allocated_buf = malloc(phsize);
 329                 if (!allocated_buf) return 0;
 330                 l = pread(fd, allocated_buf, phsize, eh->e_phoff);
 331                 if (l < 0) goto error;
 332                 if (l != phsize) goto noexec;
 333                 ph = ph0 = allocated_buf;
 334         } else if (eh->e_phoff + phsize > l) {
 335                 l = pread(fd, buf+1, phsize, eh->e_phoff);
 336                 if (l < 0) goto error;
 337                 if (l != phsize) goto noexec;
 338                 ph = ph0 = (void *)(buf + 1);
 339         } else {
 340                 ph = ph0 = (void *)((char *)buf + eh->e_phoff);
 341         }
 342         for (i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 343                 if (ph->p_type == PT_DYNAMIC)
 344                         dyn = ph->p_vaddr;
 345                 if (ph->p_type == PT_TLS) {
 346                         tls_image = ph->p_vaddr;
 347                         dso->tls_align = ph->p_align;
 348                         dso->tls_len = ph->p_filesz;
 349                         dso->tls_size = ph->p_memsz;
 350                 }
 351                 if (ph->p_type != PT_LOAD) continue;
 352                 if (ph->p_vaddr < addr_min) {
 353                         addr_min = ph->p_vaddr;
 354                         off_start = ph->p_offset;
 355                         prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 356                                 ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 357                                 ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 358                 }
 359                 if (ph->p_vaddr+ph->p_memsz > addr_max) {
 360                         addr_max = ph->p_vaddr+ph->p_memsz;
 361                 }
 362         }
 363         if (!dyn) goto noexec;
 364         addr_max += PAGE_SIZE-1;
 365         addr_max &= -PAGE_SIZE;
 366         addr_min &= -PAGE_SIZE;
 367         off_start &= -PAGE_SIZE;
 368         map_len = addr_max - addr_min + off_start;
 369         /* The first time, we map too much, possibly even more than
 370          * the length of the file. This is okay because we will not
 371          * use the invalid part; we just need to reserve the right
 372          * amount of virtual address space to map over later. */
 373         map = mmap((void *)addr_min, map_len, prot, MAP_PRIVATE, fd, off_start);
 374         if (map==MAP_FAILED) goto error;
 375         /* If the loaded file is not relocatable and the requested address is
 376          * not available, then the load operation must fail. */
 377         if (eh->e_type != ET_DYN && addr_min && map!=(void *)addr_min) {
 378                 errno = EBUSY;
 379                 goto error;
 380         }
 381         base = map - addr_min;
 382         dso->phdr = 0;
 383         dso->phnum = 0;
 384         for (ph=ph0, i=eh->e_phnum; i; i--, ph=(void *)((char *)ph+eh->e_phentsize)) {
 385                 if (ph->p_type != PT_LOAD) continue;
 386                 /* Check if the programs headers are in this load segment, and
 387                  * if so, record the address for use by dl_iterate_phdr. */
 388                 if (!dso->phdr && eh->e_phoff >= ph->p_offset
 389                     && eh->e_phoff+phsize <= ph->p_offset+ph->p_filesz) {
 390                         dso->phdr = (void *)(base + ph->p_vaddr
 391                                 + (eh->e_phoff-ph->p_offset));
 392                         dso->phnum = eh->e_phnum;
 393                 }
 394                 /* Reuse the existing mapping for the lowest-address LOAD */
 395                 if ((ph->p_vaddr & -PAGE_SIZE) == addr_min) continue;
 396                 this_min = ph->p_vaddr & -PAGE_SIZE;
 397                 this_max = ph->p_vaddr+ph->p_memsz+PAGE_SIZE-1 & -PAGE_SIZE;
 398                 off_start = ph->p_offset & -PAGE_SIZE;
 399                 prot = (((ph->p_flags&PF_R) ? PROT_READ : 0) |
 400                         ((ph->p_flags&PF_W) ? PROT_WRITE: 0) |
 401                         ((ph->p_flags&PF_X) ? PROT_EXEC : 0));
 402                 if (mmap(base+this_min, this_max-this_min, prot, MAP_PRIVATE|MAP_FIXED, fd, off_start) == MAP_FAILED)
 403                         goto error;
 404                 if (ph->p_memsz > ph->p_filesz) {
 405                         size_t brk = (size_t)base+ph->p_vaddr+ph->p_filesz;
 406                         size_t pgbrk = brk+PAGE_SIZE-1 & -PAGE_SIZE;
 407                         memset((void *)brk, 0, pgbrk-brk & PAGE_SIZE-1);
 408                         if (pgbrk-(size_t)base < this_max && mmap((void *)pgbrk, (size_t)base+this_max-pgbrk, prot, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) == MAP_FAILED)
 409                                 goto error;
 410                 }
 411         }
 412         for (i=0; ((size_t *)(base+dyn))[i]; i+=2)
 413                 if (((size_t *)(base+dyn))[i]==DT_TEXTREL) {
 414                         if (mprotect(map, map_len, PROT_READ|PROT_WRITE|PROT_EXEC) < 0)
 415                                 goto error;
 416                         break;
 417                 }
 418         if (!runtime) reclaim_gaps(base, ph0, eh->e_phentsize, eh->e_phnum);
 419         dso->map = map;
 420         dso->map_len = map_len;
 421         dso->base = base;
 422         dso->dynv = (void *)(base+dyn);
 423         if (dso->tls_size) dso->tls_image = (void *)(base+tls_image);
 424         free(allocated_buf);
 425         return map;
 426 noexec:
 427         errno = ENOEXEC;
 428 error:
 429         if (map!=MAP_FAILED) munmap(map, map_len);
 430         free(allocated_buf);
 431         return 0;
 432 }
 433
 434 static int path_open(const char *name, const char *s, char *buf, size_t buf_size)
 435 {
 436         size_t l;
 437         int fd;
 438         for (;;) {
 439                 s += strspn(s, ":\n");
 440                 l = strcspn(s, ":\n");
 441                 if (l-1 >= INT_MAX) return -1;
 442                 if (snprintf(buf, buf_size, "%.*s/%s", (int)l, s, name) >= buf_size)
 443                         continue;
 444                 if ((fd = open(buf, O_RDONLY|O_CLOEXEC))>=0) return fd;
 445                 s += l;
 446         }
 447 }
 448
 449 static void decode_dyn(struct dso *p)
 450 {
 451         size_t dyn[DYN_CNT] = {0};
 452         decode_vec(p->dynv, dyn, DYN_CNT);
 453         p->syms = (void *)(p->base + dyn[DT_SYMTAB]);
 454         p->strings = (void *)(p->base + dyn[DT_STRTAB]);
 455         if (dyn[0]&(1<<DT_HASH))
 456                 p->hashtab = (void *)(p->base + dyn[DT_HASH]);
 457         if (search_vec(p->dynv, dyn, DT_GNU_HASH))
 458                 p->ghashtab = (void *)(p->base + *dyn);
 459 }
 460
 461 static struct dso *load_library(const char *name)
 462 {
 463         char buf[2*NAME_MAX+2];
 464         const char *pathname;
 465         unsigned char *map;
 466         struct dso *p, temp_dso = {0};
 467         int fd;
 468         struct stat st;
 469         size_t alloc_size;
 470         int n_th = 0;
 471         int is_self = 0;
 472
 473         /* Catch and block attempts to reload the implementation itself */
 474         if (name[0]=='l' && name[1]=='i' && name[2]=='b') {
 475                 static const char *rp, reserved[] =
 476                         "c\0pthread\0rt\0m\0dl\0util\0xnet\0";
 477                 char *z = strchr(name, '.');
 478                 if (z) {
 479                         size_t l = z-name;
 480                         for (rp=reserved; *rp && strncmp(name+3, rp, l-3); rp+=strlen(rp)+1);
 481                         if (*rp) {
 482                                 if (ldd_mode) {
 483                                         /* Track which names have been resolved
 484                                          * and only report each one once. */
 485                                         static unsigned reported;
 486                                         unsigned mask = 1U<<(rp-reserved);
 487                                         if (!(reported & mask)) {
 488                                                 reported |= mask;
 489                                                 dprintf(1, "\t%s => %s (%p)\n",
 490                                                         name, ldso->name,
 491                                                         ldso->base);
 492                                         }
 493                                 }
 494                                 is_self = 1;
 495                         }
 496                 }
 497         }
 498         if (!strcmp(name, ldso->name)) is_self = 1;
 499         if (is_self) {
 500                 if (!ldso->prev) {
 501                         tail->next = ldso;
 502                         ldso->prev = tail;
 503                         tail = ldso->next ? ldso->next : ldso;
 504                 }
 505                 return ldso;
 506         }
 507         if (strchr(name, '/')) {
 508                 pathname = name;
 509                 fd = open(name, O_RDONLY|O_CLOEXEC);
 510         } else {
 511                 /* Search for the name to see if it's already loaded */
 512                 for (p=head->next; p; p=p->next) {
 513                         if (p->shortname && !strcmp(p->shortname, name)) {
 514                                 p->refcnt++;
 515                                 return p;
 516                         }
 517                 }
 518                 if (strlen(name) > NAME_MAX) return 0;
 519                 fd = -1;
 520                 if (r_path) fd = path_open(name, r_path, buf, sizeof buf);
 521                 if (fd < 0 && env_path) fd = path_open(name, env_path, buf, sizeof buf);
 522                 if (fd < 0) {
 523                         if (!sys_path) {
 524                                 char *prefix = 0;
 525                                 size_t prefix_len;
 526                                 if (ldso->name[0]=='/') {
 527                                         char *s, *t, *z;
 528                                         for (s=t=z=ldso->name; *s; s++)
 529                                                 if (*s=='/') z=t, t=s;
 530                                         prefix_len = z-ldso->name;
 531                                         if (prefix_len < PATH_MAX)
 532                                                 prefix = ldso->name;
 533                                 }
 534                                 if (!prefix) {
 535                                         prefix = "";
 536                                         prefix_len = 0;
 537                                 }
 538                                 char etc_ldso_path[prefix_len + 1
 539                                         + sizeof "/etc/ld-musl-" LDSO_ARCH ".path"];
 540                                 snprintf(etc_ldso_path, sizeof etc_ldso_path,
 541                                         "%.*s/etc/ld-musl-" LDSO_ARCH ".path",
 542                                         (int)prefix_len, prefix);
 543                                 FILE *f = fopen(etc_ldso_path, "rbe");
 544                                 if (f) {
 545                                         if (getdelim(&sys_path, (size_t[1]){0}, 0, f) <= 0) {
 546                                                 free(sys_path);
 547                                                 sys_path = "";
 548                                         }
 549                                         fclose(f);
 550                                 }
 551                         }
 552                         if (!sys_path) sys_path = "/lib:/usr/local/lib:/usr/lib";
 553                         fd = path_open(name, sys_path, buf, sizeof buf);
 554                 }
 555                 pathname = buf;
 556         }
 557         if (fd < 0) return 0;
 558         if (fstat(fd, &st) < 0) {
 559                 close(fd);
 560                 return 0;
 561         }
 562         for (p=head->next; p; p=p->next) {
 563                 if (p->dev == st.st_dev && p->ino == st.st_ino) {
 564                         /* If this library was previously loaded with a
 565                          * pathname but a search found the same inode,
 566                          * setup its shortname so it can be found by name. */
 567                         if (!p->shortname && pathname != name)
 568                                 p->shortname = strrchr(p->name, '/')+1;
 569                         close(fd);
 570                         p->refcnt++;
 571                         return p;
 572                 }
 573         }
 574         map = noload ? 0 : map_library(fd, &temp_dso);
 575         close(fd);
 576         if (!map) return 0;
 577
 578         /* Allocate storage for the new DSO. When there is TLS, this
 579          * storage must include a reservation for all pre-existing
 580          * threads to obtain copies of both the new TLS, and an
 581          * extended DTV capable of storing an additional slot for
 582          * the newly-loaded DSO. */
 583         alloc_size = sizeof *p + strlen(pathname) + 1;
 584         if (runtime && temp_dso.tls_image) {
 585                 size_t per_th = temp_dso.tls_size + temp_dso.tls_align
 586                         + sizeof(void *) * (tls_cnt+3);
 587                 n_th = libc.threads_minus_1 + 1;
 588                 if (n_th > SSIZE_MAX / per_th) alloc_size = SIZE_MAX;
 589                 else alloc_size += n_th * per_th;
 590         }
 591         p = calloc(1, alloc_size);
 592         if (!p) {
 593                 munmap(map, temp_dso.map_len);
 594                 return 0;
 595         }
 596         memcpy(p, &temp_dso, sizeof temp_dso);
 597         decode_dyn(p);
 598         p->dev = st.st_dev;
 599         p->ino = st.st_ino;
 600         p->refcnt = 1;
 601         p->name = p->buf;
 602         strcpy(p->name, pathname);
 603         /* Add a shortname only if name arg was not an explicit pathname. */
 604         if (pathname != name) p->shortname = strrchr(p->name, '/')+1;
 605         if (p->tls_image) {
 606                 if (runtime && !__pthread_self_init()) {
 607                         munmap(map, p->map_len);
 608                         free(p);
 609                         return 0;
 610                 }
 611                 p->tls_id = ++tls_cnt;
 612                 tls_align = MAXP2(tls_align, p->tls_align);
 613 #ifdef TLS_ABOVE_TP
 614                 p->tls_offset = tls_offset + ( (tls_align-1) &
 615                         -(tls_offset + (uintptr_t)p->tls_image) );
 616                 tls_offset += p->tls_size;
 617 #else
 618                 tls_offset += p->tls_size + p->tls_align - 1;
 619                 tls_offset -= (tls_offset + (uintptr_t)p->tls_image)
 620                         & (p->tls_align-1);
 621                 p->tls_offset = tls_offset;
 622 #endif
 623                 p->new_dtv = (void *)(-sizeof(size_t) &
 624                         (uintptr_t)(p->name+strlen(p->name)+sizeof(size_t)));
 625                 p->new_tls = (void *)(p->new_dtv + n_th*(tls_cnt+1));
 626         }
 627
 628         tail->next = p;
 629         p->prev = tail;
 630         tail = p;
 631
 632         if (ldd_mode) dprintf(1, "\t%s => %s (%p)\n", name, pathname, p->base);
 633
 634         return p;
 635 }
 636
 637 static void load_deps(struct dso *p)
 638 {
 639         size_t i, ndeps=0;
 640         struct dso ***deps = &p->deps, **tmp, *dep;
 641         for (; p; p=p->next) {
 642                 for (i=0; p->dynv[i]; i+=2) {
 643                         if (p->dynv[i] != DT_RPATH) continue;
 644                         r_path = (void *)(p->strings + p->dynv[i+1]);
 645                 }
 646                 for (i=0; p->dynv[i]; i+=2) {
 647                         if (p->dynv[i] != DT_NEEDED) continue;
 648                         dep = load_library(p->strings + p->dynv[i+1]);
 649                         if (!dep) {
 650                                 snprintf(errbuf, sizeof errbuf,
 651                                         "Error loading shared library %s: %m (needed by %s)",
 652                                         p->strings + p->dynv[i+1], p->name);
 653                                 if (runtime) longjmp(*rtld_fail, 1);
 654                                 dprintf(2, "%s\n", errbuf);
 655                                 ldso_fail = 1;
 656                                 continue;
 657                         }
 658                         if (runtime) {
 659                                 tmp = realloc(*deps, sizeof(*tmp)*(ndeps+2));
 660                                 if (!tmp) longjmp(*rtld_fail, 1);
 661                                 tmp[ndeps++] = dep;
 662                                 tmp[ndeps] = 0;
 663                                 *deps = tmp;
 664                         }
 665                 }
 666                 r_path = 0;
 667         }
 668 }
 669
 670 static void load_preload(char *s)
 671 {
 672         int tmp;
 673         char *z;
 674         for (z=s; *z; s=z) {
 675                 for (   ; *s && isspace(*s); s++);
 676                 for (z=s; *z && !isspace(*z); z++);
 677                 tmp = *z;
 678                 *z = 0;
 679                 load_library(s);
 680                 *z = tmp;
 681         }
 682 }
 683
 684 static void make_global(struct dso *p)
 685 {
 686         for (; p; p=p->next) p->global = 1;
 687 }
 688
 689 static void reloc_all(struct dso *p)
 690 {
 691         size_t dyn[DYN_CNT] = {0};
 692         for (; p; p=p->next) {
 693                 if (p->relocated) continue;
 694                 decode_vec(p->dynv, dyn, DYN_CNT);
 695 #ifdef NEED_ARCH_RELOCS
 696                 do_arch_relocs(p, head);
 697 #endif
 698                 do_relocs(p, (void *)(p->base+dyn[DT_JMPREL]), dyn[DT_PLTRELSZ],
 699                         2+(dyn[DT_PLTREL]==DT_RELA));
 700                 do_relocs(p, (void *)(p->base+dyn[DT_REL]), dyn[DT_RELSZ], 2);
 701                 do_relocs(p, (void *)(p->base+dyn[DT_RELA]), dyn[DT_RELASZ], 3);
 702                 p->relocated = 1;
 703         }
 704 }
 705
 706 static size_t find_dyn(Phdr *ph, size_t cnt, size_t stride)
 707 {
 708         for (; cnt--; ph = (void *)((char *)ph + stride))
 709                 if (ph->p_type == PT_DYNAMIC)
 710                         return ph->p_vaddr;
 711         return 0;
 712 }
 713
 714 static void find_map_range(Phdr *ph, size_t cnt, size_t stride, struct dso *p)
 715 {
 716         size_t min_addr = -1, max_addr = 0;
 717         for (; cnt--; ph = (void *)((char *)ph + stride)) {
 718                 if (ph->p_type != PT_LOAD) continue;
 719                 if (ph->p_vaddr < min_addr)
 720                         min_addr = ph->p_vaddr;
 721                 if (ph->p_vaddr+ph->p_memsz > max_addr)
 722                         max_addr = ph->p_vaddr+ph->p_memsz;
 723         }
 724         min_addr &= -PAGE_SIZE;
 725         max_addr = (max_addr + PAGE_SIZE-1) & -PAGE_SIZE;
 726         p->map = p->base + min_addr;
 727         p->map_len = max_addr - min_addr;
 728 }
 729
 730 static void do_fini()
 731 {
 732         struct dso *p;
 733         size_t dyn[DYN_CNT] = {0};
 734         for (p=fini_head; p; p=p->fini_next) {
 735                 if (!p->constructed) continue;
 736                 decode_vec(p->dynv, dyn, DYN_CNT);
 737                 if (dyn[0] & (1<<DT_FINI_ARRAY)) {
 738                         size_t n = dyn[DT_FINI_ARRAYSZ]/sizeof(size_t);
 739                         size_t *fn = (size_t *)(p->base + dyn[DT_FINI_ARRAY])+n;
 740                         while (n--) ((void (*)(void))*--fn)();
 741                 }
 742 #ifndef NO_LEGACY_INITFINI
 743                 if ((dyn[0] & (1<<DT_FINI)) && dyn[DT_FINI])
 744                         ((void (*)(void))(p->base + dyn[DT_FINI]))();
 745 #endif
 746         }
 747 }
 748
 749 static void do_init_fini(struct dso *p)
 750 {
 751         size_t dyn[DYN_CNT] = {0};
 752         int need_locking = libc.threads_minus_1;
 753         /* Allow recursive calls that arise when a library calls
 754          * dlopen from one of its constructors, but block any
 755          * other threads until all ctors have finished. */
 756         if (need_locking) pthread_mutex_lock(&init_fini_lock);
 757         for (; p; p=p->prev) {
 758                 if (p->constructed) continue;
 759                 p->constructed = 1;
 760                 decode_vec(p->dynv, dyn, DYN_CNT);
 761                 if (dyn[0] & ((1<<DT_FINI) | (1<<DT_FINI_ARRAY))) {
 762                         p->fini_next = fini_head;
 763                         fini_head = p;
 764                 }
 765 #ifndef NO_LEGACY_INITFINI
 766                 if ((dyn[0] & (1<<DT_INIT)) && dyn[DT_INIT])
 767                         ((void (*)(void))(p->base + dyn[DT_INIT]))();
 768 #endif
 769                 if (dyn[0] & (1<<DT_INIT_ARRAY)) {
 770                         size_t n = dyn[DT_INIT_ARRAYSZ]/sizeof(size_t);
 771                         size_t *fn = (void *)(p->base + dyn[DT_INIT_ARRAY]);
 772                         while (n--) ((void (*)(void))*fn++)();
 773                 }
 774                 if (!need_locking && libc.threads_minus_1) {
 775                         need_locking = 1;
 776                         pthread_mutex_lock(&init_fini_lock);
 777                 }
 778         }
 779         if (need_locking) pthread_mutex_unlock(&init_fini_lock);
 780 }
 781
 782 void _dl_debug_state(void)
 783 {
 784 }
 785
 786 void *__copy_tls(unsigned char *mem)
 787 {
 788         pthread_t td;
 789         struct dso *p;
 790
 791         if (!tls_cnt) return mem;
 792
 793         void **dtv = (void *)mem;
 794         dtv[0] = (void *)tls_cnt;
 795
 796 #ifdef TLS_ABOVE_TP
 797         mem += sizeof(void *) * (tls_cnt+1);
 798         mem += -((uintptr_t)mem + sizeof(struct pthread)) & (tls_align-1);
 799         td = (pthread_t)mem;
 800         mem += sizeof(struct pthread);
 801
 802         for (p=head; p; p=p->next) {
 803                 if (!p->tls_id) continue;
 804                 dtv[p->tls_id] = mem + p->tls_offset;
 805                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
 806         }
 807 #else
 808         mem += libc.tls_size - sizeof(struct pthread);
 809         mem -= (uintptr_t)mem & (tls_align-1);
 810         td = (pthread_t)mem;
 811
 812         for (p=head; p; p=p->next) {
 813                 if (!p->tls_id) continue;
 814                 dtv[p->tls_id] = mem - p->tls_offset;
 815                 memcpy(dtv[p->tls_id], p->tls_image, p->tls_len);
 816         }
 817 #endif
 818         td->dtv = dtv;
 819         return td;
 820 }
 821
 822 void *__tls_get_addr(size_t *v)
 823 {
 824         pthread_t self = __pthread_self();
 825         if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]])
 826                 return (char *)self->dtv[v[0]]+v[1];
 827
 828         /* Block signals to make accessing new TLS async-signal-safe */
 829         sigset_t set;
 830         pthread_sigmask(SIG_BLOCK, SIGALL_SET, &set);
 831         if (v[0]<=(size_t)self->dtv[0] && self->dtv[v[0]]) {
 832                 pthread_sigmask(SIG_SETMASK, &set, 0);
 833                 return (char *)self->dtv[v[0]]+v[1];
 834         }
 835
 836         /* This is safe without any locks held because, if the caller
 837          * is able to request the Nth entry of the DTV, the DSO list
 838          * must be valid at least that far out and it was synchronized
 839          * at program startup or by an already-completed call to dlopen. */
 840         struct dso *p;
 841         for (p=head; p->tls_id != v[0]; p=p->next);
 842
 843         /* Get new DTV space from new DSO if needed */
 844         if (v[0] > (size_t)self->dtv[0]) {
 845                 void **newdtv = p->new_dtv +
 846                         (v[0]+1)*sizeof(void *)*a_fetch_add(&p->new_dtv_idx,1);
 847                 memcpy(newdtv, self->dtv,
 848                         ((size_t)self->dtv[0]+1) * sizeof(void *));
 849                 newdtv[0] = (void *)v[0];
 850                 self->dtv = newdtv;
 851         }
 852
 853         /* Get new TLS memory from new DSO */
 854         unsigned char *mem = p->new_tls +
 855                 (p->tls_size + p->tls_align) * a_fetch_add(&p->new_tls_idx,1);
 856         mem += ((uintptr_t)p->tls_image - (uintptr_t)mem) & (p->tls_align-1);
 857         self->dtv[v[0]] = mem;
 858         memcpy(mem, p->tls_image, p->tls_len);
 859         pthread_sigmask(SIG_SETMASK, &set, 0);
 860         return mem + v[1];
 861 }
 862
 863 static void update_tls_size()
 864 {
 865         libc.tls_size = ALIGN(
 866                 (1+tls_cnt) * sizeof(void *) +
 867                 tls_offset +
 868                 sizeof(struct pthread) +
 869                 tls_align * 2,
 870         tls_align);
 871 }
 872
 873 void *__dynlink(int argc, char **argv)
 874 {
 875         size_t aux[AUX_CNT] = {0};
 876         size_t i;
 877         Phdr *phdr;
 878         Ehdr *ehdr;
 879         static struct dso builtin_dsos[3];
 880         struct dso *const app = builtin_dsos+0;
 881         struct dso *const lib = builtin_dsos+1;
 882         struct dso *const vdso = builtin_dsos+2;
 883         char *env_preload=0;
 884         size_t vdso_base;
 885         size_t *auxv;
 886         char **envp = argv+argc+1;
 887
 888         /* Find aux vector just past environ[] */
 889         for (i=argc+1; argv[i]; i++)
 890                 if (!memcmp(argv[i], "LD_LIBRARY_PATH=", 16))
 891                         env_path = argv[i]+16;
 892                 else if (!memcmp(argv[i], "LD_PRELOAD=", 11))
 893                         env_preload = argv[i]+11;
 894         auxv = (void *)(argv+i+1);
 895
 896         decode_vec(auxv, aux, AUX_CNT);
 897
 898         /* Only trust user/env if kernel says we're not suid/sgid */
 899         if ((aux[0]&0x7800)!=0x7800 || aux[AT_UID]!=aux[AT_EUID]
 900           || aux[AT_GID]!=aux[AT_EGID] || aux[AT_SECURE]) {
 901                 env_path = 0;
 902                 env_preload = 0;
 903         }
 904
 905         /* If the dynamic linker was invoked as a program itself, AT_BASE
 906          * will not be set. In that case, we assume the base address is
 907          * the start of the page containing the PHDRs; I don't know any
 908          * better approach... */
 909         if (!aux[AT_BASE]) {
 910                 aux[AT_BASE] = aux[AT_PHDR] & -PAGE_SIZE;
 911                 aux[AT_PHDR] = aux[AT_PHENT] = aux[AT_PHNUM] = 0;
 912         }
 913
 914         /* The dynamic linker load address is passed by the kernel
 915          * in the AUX vector, so this is easy. */
 916         lib->base = (void *)aux[AT_BASE];
 917         lib->name = lib->shortname = "libc.so";
 918         lib->global = 1;
 919         ehdr = (void *)lib->base;
 920         lib->phnum = ehdr->e_phnum;
 921         lib->phdr = (void *)(aux[AT_BASE]+ehdr->e_phoff);
 922         find_map_range(lib->phdr, ehdr->e_phnum, ehdr->e_phentsize, lib);
 923         lib->dynv = (void *)(lib->base + find_dyn(lib->phdr,
 924                 ehdr->e_phnum, ehdr->e_phentsize));
 925         decode_dyn(lib);
 926
 927         if (aux[AT_PHDR]) {
 928                 size_t interp_off = 0;
 929                 size_t tls_image = 0;
 930                 /* Find load address of the main program, via AT_PHDR vs PT_PHDR. */
 931                 app->phdr = phdr = (void *)aux[AT_PHDR];
 932                 app->phnum = aux[AT_PHNUM];
 933                 for (i=aux[AT_PHNUM]; i; i--, phdr=(void *)((char *)phdr + aux[AT_PHENT])) {
 934                         if (phdr->p_type == PT_PHDR)
 935                                 app->base = (void *)(aux[AT_PHDR] - phdr->p_vaddr);
 936                         else if (phdr->p_type == PT_INTERP)
 937                                 interp_off = (size_t)phdr->p_vaddr;
 938                         else if (phdr->p_type == PT_TLS) {
 939                                 tls_image = phdr->p_vaddr;
 940                                 app->tls_len = phdr->p_filesz;
 941                                 app->tls_size = phdr->p_memsz;
 942                                 app->tls_align = phdr->p_align;
 943                         }
 944                 }
 945                 if (app->tls_size) app->tls_image = (char *)app->base + tls_image;
 946                 if (interp_off) lib->name = (char *)app->base + interp_off;
 947                 app->name = argv[0];
 948                 app->dynv = (void *)(app->base + find_dyn(
 949                         (void *)aux[AT_PHDR], aux[AT_PHNUM], aux[AT_PHENT]));
 950                 find_map_range((void *)aux[AT_PHDR],
 951                         aux[AT_PHNUM], aux[AT_PHENT], app);
 952         } else {
 953                 int fd;
 954                 char *ldname = argv[0];
 955                 size_t l = strlen(ldname);
 956                 if (l >= 3 && !strcmp(ldname+l-3, "ldd")) ldd_mode = 1;
 957                 *argv++ = (void *)-1;
 958                 if (argv[0] && !strcmp(argv[0], "--")) *argv++ = (void *)-1;
 959                 if (!argv[0]) {
 960                         dprintf(2, "musl libc/dynamic program loader\n");
 961                         dprintf(2, "usage: %s pathname%s\n", ldname,
 962                                 ldd_mode ? "" : " [args]");
 963                         _exit(1);
 964                 }
 965                 fd = open(argv[0], O_RDONLY);
 966                 if (fd < 0) {
 967                         dprintf(2, "%s: cannot load %s: %s\n", ldname, argv[0], strerror(errno));
 968                         _exit(1);
 969                 }
 970                 runtime = 1;
 971                 ehdr = (void *)map_library(fd, app);
 972                 if (!ehdr) {
 973                         dprintf(2, "%s: %s: Not a valid dynamic program\n", ldname, argv[0]);
 974                         _exit(1);
 975                 }
 976                 runtime = 0;
 977                 close(fd);
 978                 lib->name = ldname;
 979                 app->name = argv[0];
 980                 aux[AT_ENTRY] = (size_t)app->base + ehdr->e_entry;
 981                 /* Find the name that would have been used for the dynamic
 982                  * linker had ldd not taken its place. */
 983                 if (ldd_mode) {
 984                         for (i=0; i<app->phnum; i++) {
 985                                 if (app->phdr[i].p_type == PT_INTERP)
 986                                         lib->name = (void *)(app->base
 987                                                 + app->phdr[i].p_vaddr);
 988                         }
 989                         dprintf(1, "\t%s (%p)\n", lib->name, lib->base);
 990                 }
 991         }
 992         if (app->tls_size) {
 993                 app->tls_id = tls_cnt = 1;
 994 #ifdef TLS_ABOVE_TP
 995                 app->tls_offset = 0;
 996                 tls_offset = app->tls_size
 997                         + ( -((uintptr_t)app->tls_image + app->tls_size)
 998                         & (app->tls_align-1) );
 999 #else
1000                 tls_offset = app->tls_offset = app->tls_size
1001                         + ( -((uintptr_t)app->tls_image + app->tls_size)
1002                         & (app->tls_align-1) );
1003 #endif
1004                 tls_align = MAXP2(tls_align, app->tls_align);
1005         }
1006         app->global = 1;
1007         decode_dyn(app);
1008
1009         /* Attach to vdso, if provided by the kernel */
1010         if (search_vec(auxv, &vdso_base, AT_SYSINFO_EHDR)) {
1011                 ehdr = (void *)vdso_base;
1012                 vdso->phdr = phdr = (void *)(vdso_base + ehdr->e_phoff);
1013                 vdso->phnum = ehdr->e_phnum;
1014                 for (i=ehdr->e_phnum; i; i--, phdr=(void *)((char *)phdr + ehdr->e_phentsize)) {
1015                         if (phdr->p_type == PT_DYNAMIC)
1016                                 vdso->dynv = (void *)(vdso_base + phdr->p_offset);
1017                         if (phdr->p_type == PT_LOAD)
1018                                 vdso->base = (void *)(vdso_base - phdr->p_vaddr + phdr->p_offset);
1019                 }
1020                 vdso->name = "";
1021                 vdso->shortname = "linux-gate.so.1";
1022                 vdso->global = 1;
1023                 decode_dyn(vdso);
1024                 vdso->prev = lib;
1025                 lib->next = vdso;
1026         }
1027
1028         /* Initial dso chain consists only of the app. We temporarily
1029          * append the dynamic linker/libc so we can relocate it, then
1030          * restore the initial chain in preparation for loading third
1031          * party libraries (preload/needed). */
1032         head = tail = app;
1033         ldso = lib;
1034         app->next = lib;
1035         reloc_all(lib);
1036         app->next = 0;
1037
1038         /* PAST THIS POINT, ALL LIBC INTERFACES ARE FULLY USABLE. */
1039
1040         /* Donate unused parts of app and library mapping to malloc */
1041         reclaim_gaps(app->base, (void *)aux[AT_PHDR], aux[AT_PHENT], aux[AT_PHNUM]);
1042         ehdr = (void *)lib->base;
1043         reclaim_gaps(lib->base, (void *)(lib->base+ehdr->e_phoff),
1044                 ehdr->e_phentsize, ehdr->e_phnum);
1045
1046         /* Load preload/needed libraries, add their symbols to the global
1047          * namespace, and perform all remaining relocations. The main
1048          * program must be relocated LAST since it may contain copy
1049          * relocations which depend on libraries' relocations. */
1050         if (env_preload) load_preload(env_preload);
1051         load_deps(app);
1052         make_global(app);
1053
1054         reloc_all(app->next);
1055         reloc_all(app);
1056
1057         update_tls_size();
1058         if (tls_cnt) {
1059                 void *mem = mmap(0, libc.tls_size, PROT_READ|PROT_WRITE,
1060                         MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
1061                 if (mem==MAP_FAILED ||
1062                     !__install_initial_tls(__copy_tls(mem))) {
1063                         dprintf(2, "%s: Error getting %zu bytes thread-local storage: %m\n",
1064                                 argv[0], libc.tls_size);
1065                         _exit(127);
1066                 }
1067         }
1068
1069         if (ldso_fail) _exit(127);
1070         if (ldd_mode) _exit(0);
1071
1072         /* Switch to runtime mode: any further failures in the dynamic
1073          * linker are a reportable failure rather than a fatal startup
1074          * error. If the dynamic loader (dlopen) will not be used, free
1075          * all memory used by the dynamic linker. */
1076         runtime = 1;
1077
1078 #ifndef DYNAMIC_IS_RO
1079         for (i=0; app->dynv[i]; i+=2)
1080                 if (app->dynv[i]==DT_DEBUG)
1081                         app->dynv[i+1] = (size_t)&debug;
1082 #endif
1083         debug.ver = 1;
1084         debug.bp = _dl_debug_state;
1085         debug.head = head;
1086         debug.base = lib->base;
1087         debug.state = 0;
1088         _dl_debug_state();
1089
1090         if (ssp_used) __init_ssp((void *)aux[AT_RANDOM]);
1091         __init_libc(envp, argv[0]);
1092         atexit(do_fini);
1093         errno = 0;
1094         do_init_fini(tail);
1095
1096         return (void *)aux[AT_ENTRY];
1097 }
1098
1099 void *dlopen(const char *file, int mode)
1100 {
1101         struct dso *volatile p, *orig_tail, *next;
1102         size_t orig_tls_cnt, orig_tls_offset, orig_tls_align;
1103         size_t i;
1104         int cs;
1105         jmp_buf jb;
1106
1107         if (!file) return head;
1108
1109         pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
1110         pthread_rwlock_wrlock(&lock);
1111         __inhibit_ptc();
1112
1113         p = 0;
1114         orig_tls_cnt = tls_cnt;
1115         orig_tls_offset = tls_offset;
1116         orig_tls_align = tls_align;
1117         orig_tail = tail;
1118         noload = mode & RTLD_NOLOAD;
1119
1120         rtld_fail = &jb;
1121         if (setjmp(*rtld_fail)) {
1122                 /* Clean up anything new that was (partially) loaded */
1123                 if (p && p->deps) for (i=0; p->deps[i]; i++)
1124                         if (p->deps[i]->global < 0)
1125                                 p->deps[i]->global = 0;
1126                 for (p=orig_tail->next; p; p=next) {
1127                         next = p->next;
1128                         munmap(p->map, p->map_len);
1129                         free(p->deps);
1130                         free(p);
1131                 }
1132                 tls_cnt = orig_tls_cnt;
1133                 tls_offset = orig_tls_offset;
1134                 tls_align = orig_tls_align;
1135                 tail = orig_tail;
1136                 tail->next = 0;
1137                 p = 0;
1138                 errflag = 1;
1139                 goto end;
1140         } else p = load_library(file);
1141
1142         if (!p) {
1143                 snprintf(errbuf, sizeof errbuf, noload ?
1144                         "Library %s is not already loaded" :
1145                         "Error loading shared library %s: %m",
1146                         file);
1147                 errflag = 1;
1148                 goto end;
1149         }
1150
1151         /* First load handling */
1152         if (!p->deps) {
1153                 load_deps(p);
1154                 if (p->deps) for (i=0; p->deps[i]; i++)
1155                         if (!p->deps[i]->global)
1156                                 p->deps[i]->global = -1;
1157                 if (!p->global) p->global = -1;
1158                 reloc_all(p);
1159                 if (p->deps) for (i=0; p->deps[i]; i++)
1160                         if (p->deps[i]->global < 0)
1161                                 p->deps[i]->global = 0;
1162                 if (p->global < 0) p->global = 0;
1163         }
1164
1165         if (mode & RTLD_GLOBAL) {
1166                 if (p->deps) for (i=0; p->deps[i]; i++)
1167                         p->deps[i]->global = 1;
1168                 p->global = 1;
1169         }
1170
1171         update_tls_size();
1172
1173         if (ssp_used) __init_ssp(libc.auxv);
1174
1175         _dl_debug_state();
1176         orig_tail = tail;
1177 end:
1178         __release_ptc();
1179         if (p) gencnt++;
1180         pthread_rwlock_unlock(&lock);
1181         if (p) do_init_fini(orig_tail);
1182         pthread_setcancelstate(cs, 0);
1183         return p;
1184 }
1185
1186 static int invalid_dso_handle(void *h)
1187 {
1188         struct dso *p;
1189         for (p=head; p; p=p->next) if (h==p) return 0;
1190         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1191         errflag = 1;
1192         return 1;
1193 }
1194
1195 static void *do_dlsym(struct dso *p, const char *s, void *ra)
1196 {
1197         size_t i;
1198         uint32_t h = 0, gh = 0;
1199         Sym *sym;
1200         if (p == head || p == RTLD_DEFAULT || p == RTLD_NEXT) {
1201                 if (p == RTLD_DEFAULT) {
1202                         p = head;
1203                 } else if (p == RTLD_NEXT) {
1204                         for (p=head; p && (unsigned char *)ra-p->map>p->map_len; p=p->next);
1205                         if (!p) p=head;
1206                         p = p->next;
1207                 }
1208                 struct symdef def = find_sym(p, s, 0);
1209                 if (!def.sym) goto failed;
1210                 if ((def.sym->st_info&0xf) == STT_TLS)
1211                         return __tls_get_addr((size_t []){def.dso->tls_id, def.sym->st_value});
1212                 return def.dso->base + def.sym->st_value;
1213         }
1214         if (p != RTLD_DEFAULT && p != RTLD_NEXT && invalid_dso_handle(p))
1215                 return 0;
1216         if (p->ghashtab) {
1217                 gh = gnu_hash(s);
1218                 sym = gnu_lookup(s, gh, p);
1219         } else {
1220                 h = sysv_hash(s);
1221                 sym = sysv_lookup(s, h, p);
1222         }
1223         if (sym && (sym->st_info&0xf) == STT_TLS)
1224                 return __tls_get_addr((size_t []){p->tls_id, sym->st_value});
1225         if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1226                 return p->base + sym->st_value;
1227         if (p->deps) for (i=0; p->deps[i]; i++) {
1228                 if (p->deps[i]->ghashtab) {
1229                         if (!gh) gh = gnu_hash(s);
1230                         sym = gnu_lookup(s, gh, p->deps[i]);
1231                 } else {
1232                         if (!h) h = sysv_hash(s);
1233                         sym = sysv_lookup(s, h, p->deps[i]);
1234                 }
1235                 if (sym && (sym->st_info&0xf) == STT_TLS)
1236                         return __tls_get_addr((size_t []){p->deps[i]->tls_id, sym->st_value});
1237                 if (sym && sym->st_value && (1<<(sym->st_info&0xf) & OK_TYPES))
1238                         return p->deps[i]->base + sym->st_value;
1239         }
1240 failed:
1241         errflag = 1;
1242         snprintf(errbuf, sizeof errbuf, "Symbol not found: %s", s);
1243         return 0;
1244 }
1245
1246 int __dladdr(void *addr, Dl_info *info)
1247 {
1248         struct dso *p;
1249         Sym *sym;
1250         uint32_t nsym;
1251         char *strings;
1252         size_t i;
1253         void *best = 0;
1254         char *bestname;
1255
1256         pthread_rwlock_rdlock(&lock);
1257         for (p=head; p && (unsigned char *)addr-p->map>p->map_len; p=p->next);
1258         pthread_rwlock_unlock(&lock);
1259
1260         if (!p) return 0;
1261
1262         sym = p->syms;
1263         strings = p->strings;
1264         if (p->hashtab) {
1265                 nsym = p->hashtab[1];
1266         } else {
1267                 uint32_t *buckets;
1268                 uint32_t *hashval;
1269                 buckets = p->ghashtab + 4 + (p->ghashtab[2]*sizeof(size_t)/4);
1270                 sym += p->ghashtab[1];
1271                 for (i = 0; i < p->ghashtab[0]; i++) {
1272                         if (buckets[i] > nsym)
1273                                 nsym = buckets[i];
1274                 }
1275                 if (nsym) {
1276                         nsym -= p->ghashtab[1];
1277                         hashval = buckets + p->ghashtab[0] + nsym;
1278                         do nsym++;
1279                         while (!(*hashval++ & 1));
1280                 }
1281         }
1282
1283         for (; nsym; nsym--, sym++) {
1284                 if (sym->st_value
1285                  && (1<<(sym->st_info&0xf) & OK_TYPES)
1286                  && (1<<(sym->st_info>>4) & OK_BINDS)) {
1287                         void *symaddr = p->base + sym->st_value;
1288                         if (symaddr > addr || symaddr < best)
1289                                 continue;
1290                         best = symaddr;
1291                         bestname = strings + sym->st_name;
1292                         if (addr == symaddr)
1293                                 break;
1294                 }
1295         }
1296
1297         if (!best) return 0;
1298
1299         info->dli_fname = p->name;
1300         info->dli_fbase = p->base;
1301         info->dli_sname = bestname;
1302         info->dli_saddr = best;
1303
1304         return 1;
1305 }
1306
1307 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1308 {
1309         void *res;
1310         pthread_rwlock_rdlock(&lock);
1311         res = do_dlsym(p, s, ra);
1312         pthread_rwlock_unlock(&lock);
1313         return res;
1314 }
1315
1316 int dl_iterate_phdr(int(*callback)(struct dl_phdr_info *info, size_t size, void *data), void *data)
1317 {
1318         struct dso *current;
1319         struct dl_phdr_info info;
1320         int ret = 0;
1321         for(current = head; current;) {
1322                 info.dlpi_addr      = (uintptr_t)current->base;
1323                 info.dlpi_name      = current->name;
1324                 info.dlpi_phdr      = current->phdr;
1325                 info.dlpi_phnum     = current->phnum;
1326                 info.dlpi_adds      = gencnt;
1327                 info.dlpi_subs      = 0;
1328                 info.dlpi_tls_modid = current->tls_id;
1329                 info.dlpi_tls_data  = current->tls_image;
1330
1331                 ret = (callback)(&info, sizeof (info), data);
1332
1333                 if (ret != 0) break;
1334
1335                 pthread_rwlock_rdlock(&lock);
1336                 current = current->next;
1337                 pthread_rwlock_unlock(&lock);
1338         }
1339         return ret;
1340 }
1341 #else
1342 static int invalid_dso_handle(void *h)
1343 {
1344         snprintf(errbuf, sizeof errbuf, "Invalid library handle %p", (void *)h);
1345         errflag = 1;
1346         return 1;
1347 }
1348 void *dlopen(const char *file, int mode)
1349 {
1350         return 0;
1351 }
1352 void *__dlsym(void *restrict p, const char *restrict s, void *restrict ra)
1353 {
1354         return 0;
1355 }
1356 int __dladdr (void *addr, Dl_info *info)
1357 {
1358         return 0;
1359 }
1360 #endif
1361
1362 int __dlinfo(void *dso, int req, void *res)
1363 {
1364         if (invalid_dso_handle(dso)) return -1;
1365         if (req != RTLD_DI_LINKMAP) {
1366                 snprintf(errbuf, sizeof errbuf, "Unsupported request %d", req);
1367                 errflag = 1;
1368                 return -1;
1369         }
1370         *(struct link_map **)res = dso;
1371         return 0;
1372 }
1373
1374 char *dlerror()
1375 {
1376         if (!errflag) return 0;
1377         errflag = 0;
1378         return errbuf;
1379 }
1380
1381 int dlclose(void *p)
1382 {
1383         return invalid_dso_handle(p);
1384 }