fs/binfmt_elf.c

   1 /*
   2  * linux/fs/binfmt_elf.c
   3  *
   4  * These are the functions used to load ELF format executables as used
   5  * on SVr4 machines.  Information on the format may be found in the book
   6  * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
   7  * Tools".
   8  *
   9  * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/fs.h>
  15 #include <linux/stat.h>
  16 #include <linux/time.h>
  17 #include <linux/mm.h>
  18 #include <linux/mman.h>
  19 #include <linux/a.out.h>
  20 #include <linux/errno.h>
  21 #include <linux/signal.h>
  22 #include <linux/binfmts.h>
  23 #include <linux/string.h>
  24 #include <linux/file.h>
  25 #include <linux/fcntl.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/slab.h>
  28 #include <linux/shm.h>
  29 #include <linux/personality.h>
  30 #include <linux/elfcore.h>
  31 #include <linux/init.h>
  32 #include <linux/highuid.h>
  33 #include <linux/smp.h>
  34 #include <linux/compiler.h>
  35 #include <linux/highmem.h>
  36 #include <linux/pagemap.h>
  37 #include <linux/security.h>
  38 #include <linux/syscalls.h>
  39 #include <linux/random.h>
  40 #include <linux/elf.h>
  41 #include <linux/utsname.h>
  42 #include <asm/uaccess.h>
  43 #include <asm/param.h>
  44 #include <asm/page.h>
  45
  46 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
  47 static int load_elf_library(struct file *);
  48 static unsigned long elf_map (struct file *, unsigned long, struct elf_phdr *, int, int, unsigned long);
  49
  50 /*
  51  * If we don't support core dumping, then supply a NULL so we
  52  * don't even try.
  53  */
  54 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  55 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file);
  56 #else
  57 #define elf_core_dump   NULL
  58 #endif
  59
  60 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
  61 #define ELF_MIN_ALIGN   ELF_EXEC_PAGESIZE
  62 #else
  63 #define ELF_MIN_ALIGN   PAGE_SIZE
  64 #endif
  65
  66 #ifndef ELF_CORE_EFLAGS
  67 #define ELF_CORE_EFLAGS 0
  68 #endif
  69
  70 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
  71 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
  72 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
  73
  74 static struct linux_binfmt elf_format = {
  75                 .module         = THIS_MODULE,
  76                 .load_binary    = load_elf_binary,
  77                 .load_shlib     = load_elf_library,
  78                 .core_dump      = elf_core_dump,
  79                 .min_coredump   = ELF_EXEC_PAGESIZE,
  80                 .hasvdso        = 1
  81 };
  82
  83 #define BAD_ADDR(x) IS_ERR_VALUE(x)
  84
  85 static int set_brk(unsigned long start, unsigned long end)
  86 {
  87         start = ELF_PAGEALIGN(start);
  88         end = ELF_PAGEALIGN(end);
  89         if (end > start) {
  90                 unsigned long addr;
  91                 down_write(&current->mm->mmap_sem);
  92                 addr = do_brk(start, end - start);
  93                 up_write(&current->mm->mmap_sem);
  94                 if (BAD_ADDR(addr))
  95                         return addr;
  96         }
  97         current->mm->start_brk = current->mm->brk = end;
  98         return 0;
  99 }
 100
 101 /* We need to explicitly zero any fractional pages
 102    after the data section (i.e. bss).  This would
 103    contain the junk from the file that should not
 104    be in memory
 105  */
 106 static int padzero(unsigned long elf_bss)
 107 {
 108         unsigned long nbyte;
 109
 110         nbyte = ELF_PAGEOFFSET(elf_bss);
 111         if (nbyte) {
 112                 nbyte = ELF_MIN_ALIGN - nbyte;
 113                 if (clear_user((void __user *) elf_bss, nbyte))
 114                         return -EFAULT;
 115         }
 116         return 0;
 117 }
 118
 119 /* Let's use some macros to make this stack manipulation a litle clearer */
 120 #ifdef CONFIG_STACK_GROWSUP
 121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
 122 #define STACK_ROUND(sp, items) \
 123         ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
 124 #define STACK_ALLOC(sp, len) ({ \
 125         elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
 126         old_sp; })
 127 #else
 128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
 129 #define STACK_ROUND(sp, items) \
 130         (((unsigned long) (sp - items)) &~ 15UL)
 131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
 132 #endif
 133
 134 static int
 135 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
 136                 int interp_aout, unsigned long load_addr,
 137                 unsigned long interp_load_addr)
 138 {
 139         unsigned long p = bprm->p;
 140         int argc = bprm->argc;
 141         int envc = bprm->envc;
 142         elf_addr_t __user *argv;
 143         elf_addr_t __user *envp;
 144         elf_addr_t __user *sp;
 145         elf_addr_t __user *u_platform;
 146         const char *k_platform = ELF_PLATFORM;
 147         int items;
 148         elf_addr_t *elf_info;
 149         int ei_index = 0;
 150         struct task_struct *tsk = current;
 151
 152         /*
 153          * If this architecture has a platform capability string, copy it
 154          * to userspace.  In some cases (Sparc), this info is impossible
 155          * for userspace to get any other way, in others (i386) it is
 156          * merely difficult.
 157          */
 158         u_platform = NULL;
 159         if (k_platform) {
 160                 size_t len = strlen(k_platform) + 1;
 161
 162                 /*
 163                  * In some cases (e.g. Hyper-Threading), we want to avoid L1
 164                  * evictions by the processes running on the same package. One
 165                  * thing we can do is to shuffle the initial stack for them.
 166                  */
 167
 168                 p = arch_align_stack(p);
 169
 170                 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
 171                 if (__copy_to_user(u_platform, k_platform, len))
 172                         return -EFAULT;
 173         }
 174
 175         /* Create the ELF interpreter info */
 176         elf_info = (elf_addr_t *)current->mm->saved_auxv;
 177 #define NEW_AUX_ENT(id, val) \
 178         do { \
 179                 elf_info[ei_index++] = id; \
 180                 elf_info[ei_index++] = val; \
 181         } while (0)
 182
 183 #ifdef ARCH_DLINFO
 184         /*
 185          * ARCH_DLINFO must come first so PPC can do its special alignment of
 186          * AUXV.
 187          */
 188         ARCH_DLINFO;
 189 #endif
 190         NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
 191         NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
 192         NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
 193         NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
 194         NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
 195         NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
 196         NEW_AUX_ENT(AT_BASE, interp_load_addr);
 197         NEW_AUX_ENT(AT_FLAGS, 0);
 198         NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
 199         NEW_AUX_ENT(AT_UID, tsk->uid);
 200         NEW_AUX_ENT(AT_EUID, tsk->euid);
 201         NEW_AUX_ENT(AT_GID, tsk->gid);
 202         NEW_AUX_ENT(AT_EGID, tsk->egid);
 203         NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
 204         if (k_platform) {
 205                 NEW_AUX_ENT(AT_PLATFORM,
 206                             (elf_addr_t)(unsigned long)u_platform);
 207         }
 208         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 209                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 210         }
 211 #undef NEW_AUX_ENT
 212         /* AT_NULL is zero; clear the rest too */
 213         memset(&elf_info[ei_index], 0,
 214                sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
 215
 216         /* And advance past the AT_NULL entry.  */
 217         ei_index += 2;
 218
 219         sp = STACK_ADD(p, ei_index);
 220
 221         items = (argc + 1) + (envc + 1);
 222         if (interp_aout) {
 223                 items += 3; /* a.out interpreters require argv & envp too */
 224         } else {
 225                 items += 1; /* ELF interpreters only put argc on the stack */
 226         }
 227         bprm->p = STACK_ROUND(sp, items);
 228
 229         /* Point sp at the lowest address on the stack */
 230 #ifdef CONFIG_STACK_GROWSUP
 231         sp = (elf_addr_t __user *)bprm->p - items - ei_index;
 232         bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
 233 #else
 234         sp = (elf_addr_t __user *)bprm->p;
 235 #endif
 236
 237         /* Now, let's put argc (and argv, envp if appropriate) on the stack */
 238         if (__put_user(argc, sp++))
 239                 return -EFAULT;
 240         if (interp_aout) {
 241                 argv = sp + 2;
 242                 envp = argv + argc + 1;
 243                 if (__put_user((elf_addr_t)(unsigned long)argv, sp++) ||
 244                     __put_user((elf_addr_t)(unsigned long)envp, sp++))
 245                         return -EFAULT;
 246         } else {
 247                 argv = sp;
 248                 envp = argv + argc + 1;
 249         }
 250
 251         /* Populate argv and envp */
 252         p = current->mm->arg_end = current->mm->arg_start;
 253         while (argc-- > 0) {
 254                 size_t len;
 255                 if (__put_user((elf_addr_t)p, argv++))
 256                         return -EFAULT;
 257                 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
 258                 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
 259                         return 0;
 260                 p += len;
 261         }
 262         if (__put_user(0, argv))
 263                 return -EFAULT;
 264         current->mm->arg_end = current->mm->env_start = p;
 265         while (envc-- > 0) {
 266                 size_t len;
 267                 if (__put_user((elf_addr_t)p, envp++))
 268                         return -EFAULT;
 269                 len = strnlen_user((void __user *)p, PAGE_SIZE*MAX_ARG_PAGES);
 270                 if (!len || len > PAGE_SIZE*MAX_ARG_PAGES)
 271                         return 0;
 272                 p += len;
 273         }
 274         if (__put_user(0, envp))
 275                 return -EFAULT;
 276         current->mm->env_end = p;
 277
 278         /* Put the elf_info on the stack in the right place.  */
 279         sp = (elf_addr_t __user *)envp + 1;
 280         if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
 281                 return -EFAULT;
 282         return 0;
 283 }
 284
 285 #ifndef elf_map
 286
 287 static unsigned long elf_map(struct file *filep, unsigned long addr,
 288                 struct elf_phdr *eppnt, int prot, int type,
 289                 unsigned long total_size)
 290 {
 291         unsigned long map_addr;
 292         unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
 293         unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
 294         addr = ELF_PAGESTART(addr);
 295         size = ELF_PAGEALIGN(size);
 296
 297         /* mmap() will return -EINVAL if given a zero size, but a
 298          * segment with zero filesize is perfectly valid */
 299         if (!size)
 300                 return addr;
 301
 302         down_write(&current->mm->mmap_sem);
 303         /*
 304         * total_size is the size of the ELF (interpreter) image.
 305         * The _first_ mmap needs to know the full size, otherwise
 306         * randomization might put this image into an overlapping
 307         * position with the ELF binary image. (since size < total_size)
 308         * So we first map the 'big' image - and unmap the remainder at
 309         * the end. (which unmap is needed for ELF images with holes.)
 310         */
 311         if (total_size) {
 312                 total_size = ELF_PAGEALIGN(total_size);
 313                 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
 314                 if (!BAD_ADDR(map_addr))
 315                         do_munmap(current->mm, map_addr+size, total_size-size);
 316         } else
 317                 map_addr = do_mmap(filep, addr, size, prot, type, off);
 318
 319         up_write(&current->mm->mmap_sem);
 320         return(map_addr);
 321 }
 322
 323 #endif /* !elf_map */
 324
 325 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
 326 {
 327         int i, first_idx = -1, last_idx = -1;
 328
 329         for (i = 0; i < nr; i++) {
 330                 if (cmds[i].p_type == PT_LOAD) {
 331                         last_idx = i;
 332                         if (first_idx == -1)
 333                                 first_idx = i;
 334                 }
 335         }
 336         if (first_idx == -1)
 337                 return 0;
 338
 339         return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
 340                                 ELF_PAGESTART(cmds[first_idx].p_vaddr);
 341 }
 342
 343
 344 /* This is much more generalized than the library routine read function,
 345    so we keep this separate.  Technically the library read function
 346    is only provided so that we can read a.out libraries that have
 347    an ELF header */
 348
 349 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
 350                 struct file *interpreter, unsigned long *interp_map_addr,
 351                 unsigned long no_base)
 352 {
 353         struct elf_phdr *elf_phdata;
 354         struct elf_phdr *eppnt;
 355         unsigned long load_addr = 0;
 356         int load_addr_set = 0;
 357         unsigned long last_bss = 0, elf_bss = 0;
 358         unsigned long error = ~0UL;
 359         unsigned long total_size;
 360         int retval, i, size;
 361
 362         /* First of all, some simple consistency checks */
 363         if (interp_elf_ex->e_type != ET_EXEC &&
 364             interp_elf_ex->e_type != ET_DYN)
 365                 goto out;
 366         if (!elf_check_arch(interp_elf_ex))
 367                 goto out;
 368         if (!interpreter->f_op || !interpreter->f_op->mmap)
 369                 goto out;
 370
 371         /*
 372          * If the size of this structure has changed, then punt, since
 373          * we will be doing the wrong thing.
 374          */
 375         if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
 376                 goto out;
 377         if (interp_elf_ex->e_phnum < 1 ||
 378                 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
 379                 goto out;
 380
 381         /* Now read in all of the header information */
 382         size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
 383         if (size > ELF_MIN_ALIGN)
 384                 goto out;
 385         elf_phdata = kmalloc(size, GFP_KERNEL);
 386         if (!elf_phdata)
 387                 goto out;
 388
 389         retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
 390                              (char *)elf_phdata,size);
 391         error = -EIO;
 392         if (retval != size) {
 393                 if (retval < 0)
 394                         error = retval;
 395                 goto out_close;
 396         }
 397
 398         total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
 399         if (!total_size) {
 400                 error = -EINVAL;
 401                 goto out_close;
 402         }
 403
 404         eppnt = elf_phdata;
 405         for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
 406                 if (eppnt->p_type == PT_LOAD) {
 407                         int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
 408                         int elf_prot = 0;
 409                         unsigned long vaddr = 0;
 410                         unsigned long k, map_addr;
 411
 412                         if (eppnt->p_flags & PF_R)
 413                                 elf_prot = PROT_READ;
 414                         if (eppnt->p_flags & PF_W)
 415                                 elf_prot |= PROT_WRITE;
 416                         if (eppnt->p_flags & PF_X)
 417                                 elf_prot |= PROT_EXEC;
 418                         vaddr = eppnt->p_vaddr;
 419                         if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
 420                                 elf_type |= MAP_FIXED;
 421                         else if (no_base && interp_elf_ex->e_type == ET_DYN)
 422                                 load_addr = -vaddr;
 423
 424                         map_addr = elf_map(interpreter, load_addr + vaddr,
 425                                            eppnt, elf_prot, elf_type, total_size);
 426                         total_size = 0;
 427                         if (!*interp_map_addr)
 428                                 *interp_map_addr = map_addr;
 429                         error = map_addr;
 430                         if (BAD_ADDR(map_addr))
 431                                 goto out_close;
 432
 433                         if (!load_addr_set &&
 434                             interp_elf_ex->e_type == ET_DYN) {
 435                                 load_addr = map_addr - ELF_PAGESTART(vaddr);
 436                                 load_addr_set = 1;
 437                         }
 438
 439                         /*
 440                          * Check to see if the section's size will overflow the
 441                          * allowed task size. Note that p_filesz must always be
 442                          * <= p_memsize so it's only necessary to check p_memsz.
 443                          */
 444                         k = load_addr + eppnt->p_vaddr;
 445                         if (BAD_ADDR(k) ||
 446                             eppnt->p_filesz > eppnt->p_memsz ||
 447                             eppnt->p_memsz > TASK_SIZE ||
 448                             TASK_SIZE - eppnt->p_memsz < k) {
 449                                 error = -ENOMEM;
 450                                 goto out_close;
 451                         }
 452
 453                         /*
 454                          * Find the end of the file mapping for this phdr, and
 455                          * keep track of the largest address we see for this.
 456                          */
 457                         k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
 458                         if (k > elf_bss)
 459                                 elf_bss = k;
 460
 461                         /*
 462                          * Do the same thing for the memory mapping - between
 463                          * elf_bss and last_bss is the bss section.
 464                          */
 465                         k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
 466                         if (k > last_bss)
 467                                 last_bss = k;
 468                 }
 469         }
 470
 471         /*
 472          * Now fill out the bss section.  First pad the last page up
 473          * to the page boundary, and then perform a mmap to make sure
 474          * that there are zero-mapped pages up to and including the
 475          * last bss page.
 476          */
 477         if (padzero(elf_bss)) {
 478                 error = -EFAULT;
 479                 goto out_close;
 480         }
 481
 482         /* What we have mapped so far */
 483         elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
 484
 485         /* Map the last of the bss segment */
 486         if (last_bss > elf_bss) {
 487                 down_write(&current->mm->mmap_sem);
 488                 error = do_brk(elf_bss, last_bss - elf_bss);
 489                 up_write(&current->mm->mmap_sem);
 490                 if (BAD_ADDR(error))
 491                         goto out_close;
 492         }
 493
 494         error = load_addr;
 495
 496 out_close:
 497         kfree(elf_phdata);
 498 out:
 499         return error;
 500 }
 501
 502 static unsigned long load_aout_interp(struct exec *interp_ex,
 503                 struct file *interpreter)
 504 {
 505         unsigned long text_data, elf_entry = ~0UL;
 506         char __user * addr;
 507         loff_t offset;
 508
 509         current->mm->end_code = interp_ex->a_text;
 510         text_data = interp_ex->a_text + interp_ex->a_data;
 511         current->mm->end_data = text_data;
 512         current->mm->brk = interp_ex->a_bss + text_data;
 513
 514         switch (N_MAGIC(*interp_ex)) {
 515         case OMAGIC:
 516                 offset = 32;
 517                 addr = (char __user *)0;
 518                 break;
 519         case ZMAGIC:
 520         case QMAGIC:
 521                 offset = N_TXTOFF(*interp_ex);
 522                 addr = (char __user *)N_TXTADDR(*interp_ex);
 523                 break;
 524         default:
 525                 goto out;
 526         }
 527
 528         down_write(&current->mm->mmap_sem);
 529         do_brk(0, text_data);
 530         up_write(&current->mm->mmap_sem);
 531         if (!interpreter->f_op || !interpreter->f_op->read)
 532                 goto out;
 533         if (interpreter->f_op->read(interpreter, addr, text_data, &offset) < 0)
 534                 goto out;
 535         flush_icache_range((unsigned long)addr,
 536                            (unsigned long)addr + text_data);
 537
 538         down_write(&current->mm->mmap_sem);
 539         do_brk(ELF_PAGESTART(text_data + ELF_MIN_ALIGN - 1),
 540                 interp_ex->a_bss);
 541         up_write(&current->mm->mmap_sem);
 542         elf_entry = interp_ex->a_entry;
 543
 544 out:
 545         return elf_entry;
 546 }
 547
 548 /*
 549  * These are the functions used to load ELF style executables and shared
 550  * libraries.  There is no binary dependent code anywhere else.
 551  */
 552
 553 #define INTERPRETER_NONE 0
 554 #define INTERPRETER_AOUT 1
 555 #define INTERPRETER_ELF 2
 556
 557 #ifndef STACK_RND_MASK
 558 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12))     /* 8MB of VA */
 559 #endif
 560
 561 static unsigned long randomize_stack_top(unsigned long stack_top)
 562 {
 563         unsigned int random_variable = 0;
 564
 565         if ((current->flags & PF_RANDOMIZE) &&
 566                 !(current->personality & ADDR_NO_RANDOMIZE)) {
 567                 random_variable = get_random_int() & STACK_RND_MASK;
 568                 random_variable <<= PAGE_SHIFT;
 569         }
 570 #ifdef CONFIG_STACK_GROWSUP
 571         return PAGE_ALIGN(stack_top) + random_variable;
 572 #else
 573         return PAGE_ALIGN(stack_top) - random_variable;
 574 #endif
 575 }
 576
 577 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 578 {
 579         struct file *interpreter = NULL; /* to shut gcc up */
 580         unsigned long load_addr = 0, load_bias = 0;
 581         int load_addr_set = 0;
 582         char * elf_interpreter = NULL;
 583         unsigned int interpreter_type = INTERPRETER_NONE;
 584         unsigned char ibcs2_interpreter = 0;
 585         unsigned long error;
 586         struct elf_phdr *elf_ppnt, *elf_phdata;
 587         unsigned long elf_bss, elf_brk;
 588         int elf_exec_fileno;
 589         int retval, i;
 590         unsigned int size;
 591         unsigned long elf_entry;
 592         unsigned long interp_load_addr = 0;
 593         unsigned long start_code, end_code, start_data, end_data;
 594         unsigned long reloc_func_desc = 0;
 595         char passed_fileno[6];
 596         struct files_struct *files;
 597         int executable_stack = EXSTACK_DEFAULT;
 598         unsigned long def_flags = 0;
 599         struct {
 600                 struct elfhdr elf_ex;
 601                 struct elfhdr interp_elf_ex;
 602                 struct exec interp_ex;
 603         } *loc;
 604
 605         loc = kmalloc(sizeof(*loc), GFP_KERNEL);
 606         if (!loc) {
 607                 retval = -ENOMEM;
 608                 goto out_ret;
 609         }
 610
 611         /* Get the exec-header */
 612         loc->elf_ex = *((struct elfhdr *)bprm->buf);
 613
 614         retval = -ENOEXEC;
 615         /* First of all, some simple consistency checks */
 616         if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
 617                 goto out;
 618
 619         if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
 620                 goto out;
 621         if (!elf_check_arch(&loc->elf_ex))
 622                 goto out;
 623         if (!bprm->file->f_op||!bprm->file->f_op->mmap)
 624                 goto out;
 625
 626         /* Now read in all of the header information */
 627         if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
 628                 goto out;
 629         if (loc->elf_ex.e_phnum < 1 ||
 630                 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
 631                 goto out;
 632         size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
 633         retval = -ENOMEM;
 634         elf_phdata = kmalloc(size, GFP_KERNEL);
 635         if (!elf_phdata)
 636                 goto out;
 637
 638         retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
 639                              (char *)elf_phdata, size);
 640         if (retval != size) {
 641                 if (retval >= 0)
 642                         retval = -EIO;
 643                 goto out_free_ph;
 644         }
 645
 646         files = current->files; /* Refcounted so ok */
 647         retval = unshare_files();
 648         if (retval < 0)
 649                 goto out_free_ph;
 650         if (files == current->files) {
 651                 put_files_struct(files);
 652                 files = NULL;
 653         }
 654
 655         /* exec will make our files private anyway, but for the a.out
 656            loader stuff we need to do it earlier */
 657         retval = get_unused_fd();
 658         if (retval < 0)
 659                 goto out_free_fh;
 660         get_file(bprm->file);
 661         fd_install(elf_exec_fileno = retval, bprm->file);
 662
 663         elf_ppnt = elf_phdata;
 664         elf_bss = 0;
 665         elf_brk = 0;
 666
 667         start_code = ~0UL;
 668         end_code = 0;
 669         start_data = 0;
 670         end_data = 0;
 671
 672         for (i = 0; i < loc->elf_ex.e_phnum; i++) {
 673                 if (elf_ppnt->p_type == PT_INTERP) {
 674                         /* This is the program interpreter used for
 675                          * shared libraries - for now assume that this
 676                          * is an a.out format binary
 677                          */
 678                         retval = -ENOEXEC;
 679                         if (elf_ppnt->p_filesz > PATH_MAX ||
 680                             elf_ppnt->p_filesz < 2)
 681                                 goto out_free_file;
 682
 683                         retval = -ENOMEM;
 684                         elf_interpreter = kmalloc(elf_ppnt->p_filesz,
 685                                                   GFP_KERNEL);
 686                         if (!elf_interpreter)
 687                                 goto out_free_file;
 688
 689                         retval = kernel_read(bprm->file, elf_ppnt->p_offset,
 690                                              elf_interpreter,
 691                                              elf_ppnt->p_filesz);
 692                         if (retval != elf_ppnt->p_filesz) {
 693                                 if (retval >= 0)
 694                                         retval = -EIO;
 695                                 goto out_free_interp;
 696                         }
 697                         /* make sure path is NULL terminated */
 698                         retval = -ENOEXEC;
 699                         if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
 700                                 goto out_free_interp;
 701
 702                         /* If the program interpreter is one of these two,
 703                          * then assume an iBCS2 image. Otherwise assume
 704                          * a native linux image.
 705                          */
 706                         if (strcmp(elf_interpreter,"/usr/lib/libc.so.1") == 0 ||
 707                             strcmp(elf_interpreter,"/usr/lib/ld.so.1") == 0)
 708                                 ibcs2_interpreter = 1;
 709
 710                         /*
 711                          * The early SET_PERSONALITY here is so that the lookup
 712                          * for the interpreter happens in the namespace of the
 713                          * to-be-execed image.  SET_PERSONALITY can select an
 714                          * alternate root.
 715                          *
 716                          * However, SET_PERSONALITY is NOT allowed to switch
 717                          * this task into the new images's memory mapping
 718                          * policy - that is, TASK_SIZE must still evaluate to
 719                          * that which is appropriate to the execing application.
 720                          * This is because exit_mmap() needs to have TASK_SIZE
 721                          * evaluate to the size of the old image.
 722                          *
 723                          * So if (say) a 64-bit application is execing a 32-bit
 724                          * application it is the architecture's responsibility
 725                          * to defer changing the value of TASK_SIZE until the
 726                          * switch really is going to happen - do this in
 727                          * flush_thread().      - akpm
 728                          */
 729                         SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
 730
 731                         interpreter = open_exec(elf_interpreter);
 732                         retval = PTR_ERR(interpreter);
 733                         if (IS_ERR(interpreter))
 734                                 goto out_free_interp;
 735
 736                         /*
 737                          * If the binary is not readable then enforce
 738                          * mm->dumpable = 0 regardless of the interpreter's
 739                          * permissions.
 740                          */
 741                         if (file_permission(interpreter, MAY_READ) < 0)
 742                                 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
 743
 744                         retval = kernel_read(interpreter, 0, bprm->buf,
 745                                              BINPRM_BUF_SIZE);
 746                         if (retval != BINPRM_BUF_SIZE) {
 747                                 if (retval >= 0)
 748                                         retval = -EIO;
 749                                 goto out_free_dentry;
 750                         }
 751
 752                         /* Get the exec headers */
 753                         loc->interp_ex = *((struct exec *)bprm->buf);
 754                         loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
 755                         break;
 756                 }
 757                 elf_ppnt++;
 758         }
 759
 760         elf_ppnt = elf_phdata;
 761         for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
 762                 if (elf_ppnt->p_type == PT_GNU_STACK) {
 763                         if (elf_ppnt->p_flags & PF_X)
 764                                 executable_stack = EXSTACK_ENABLE_X;
 765                         else
 766                                 executable_stack = EXSTACK_DISABLE_X;
 767                         break;
 768                 }
 769
 770         /* Some simple consistency checks for the interpreter */
 771         if (elf_interpreter) {
 772                 interpreter_type = INTERPRETER_ELF | INTERPRETER_AOUT;
 773
 774                 /* Now figure out which format our binary is */
 775                 if ((N_MAGIC(loc->interp_ex) != OMAGIC) &&
 776                     (N_MAGIC(loc->interp_ex) != ZMAGIC) &&
 777                     (N_MAGIC(loc->interp_ex) != QMAGIC))
 778                         interpreter_type = INTERPRETER_ELF;
 779
 780                 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
 781                         interpreter_type &= ~INTERPRETER_ELF;
 782
 783                 retval = -ELIBBAD;
 784                 if (!interpreter_type)
 785                         goto out_free_dentry;
 786
 787                 /* Make sure only one type was selected */
 788                 if ((interpreter_type & INTERPRETER_ELF) &&
 789                      interpreter_type != INTERPRETER_ELF) {
 790                         // FIXME - ratelimit this before re-enabling
 791                         // printk(KERN_WARNING "ELF: Ambiguous type, using ELF\n");
 792                         interpreter_type = INTERPRETER_ELF;
 793                 }
 794                 /* Verify the interpreter has a valid arch */
 795                 if ((interpreter_type == INTERPRETER_ELF) &&
 796                     !elf_check_arch(&loc->interp_elf_ex))
 797                         goto out_free_dentry;
 798         } else {
 799                 /* Executables without an interpreter also need a personality  */
 800                 SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
 801         }
 802
 803         /* OK, we are done with that, now set up the arg stuff,
 804            and then start this sucker up */
 805         if ((!bprm->sh_bang) && (interpreter_type == INTERPRETER_AOUT)) {
 806                 char *passed_p = passed_fileno;
 807                 sprintf(passed_fileno, "%d", elf_exec_fileno);
 808
 809                 if (elf_interpreter) {
 810                         retval = copy_strings_kernel(1, &passed_p, bprm);
 811                         if (retval)
 812                                 goto out_free_dentry;
 813                         bprm->argc++;
 814                 }
 815         }
 816
 817         /* Flush all traces of the currently running executable */
 818         retval = flush_old_exec(bprm);
 819         if (retval)
 820                 goto out_free_dentry;
 821
 822         /* Discard our unneeded old files struct */
 823         if (files) {
 824                 put_files_struct(files);
 825                 files = NULL;
 826         }
 827
 828         /* OK, This is the point of no return */
 829         current->mm->start_data = 0;
 830         current->mm->end_data = 0;
 831         current->mm->end_code = 0;
 832         current->mm->mmap = NULL;
 833         current->flags &= ~PF_FORKNOEXEC;
 834         current->mm->def_flags = def_flags;
 835
 836         /* Do this immediately, since STACK_TOP as used in setup_arg_pages
 837            may depend on the personality.  */
 838         SET_PERSONALITY(loc->elf_ex, ibcs2_interpreter);
 839         if (elf_read_implies_exec(loc->elf_ex, executable_stack))
 840                 current->personality |= READ_IMPLIES_EXEC;
 841
 842         if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
 843                 current->flags |= PF_RANDOMIZE;
 844         arch_pick_mmap_layout(current->mm);
 845
 846         /* Do this so that we can load the interpreter, if need be.  We will
 847            change some of these later */
 848         current->mm->free_area_cache = current->mm->mmap_base;
 849         current->mm->cached_hole_size = 0;
 850         retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
 851                                  executable_stack);
 852         if (retval < 0) {
 853                 send_sig(SIGKILL, current, 0);
 854                 goto out_free_dentry;
 855         }
 856
 857         current->mm->start_stack = bprm->p;
 858
 859         /* Now we do a little grungy work by mmaping the ELF image into
 860            the correct location in memory. */
 861         for(i = 0, elf_ppnt = elf_phdata;
 862             i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
 863                 int elf_prot = 0, elf_flags;
 864                 unsigned long k, vaddr;
 865
 866                 if (elf_ppnt->p_type != PT_LOAD)
 867                         continue;
 868
 869                 if (unlikely (elf_brk > elf_bss)) {
 870                         unsigned long nbyte;
 871
 872                         /* There was a PT_LOAD segment with p_memsz > p_filesz
 873                            before this one. Map anonymous pages, if needed,
 874                            and clear the area.  */
 875                         retval = set_brk (elf_bss + load_bias,
 876                                           elf_brk + load_bias);
 877                         if (retval) {
 878                                 send_sig(SIGKILL, current, 0);
 879                                 goto out_free_dentry;
 880                         }
 881                         nbyte = ELF_PAGEOFFSET(elf_bss);
 882                         if (nbyte) {
 883                                 nbyte = ELF_MIN_ALIGN - nbyte;
 884                                 if (nbyte > elf_brk - elf_bss)
 885                                         nbyte = elf_brk - elf_bss;
 886                                 if (clear_user((void __user *)elf_bss +
 887                                                         load_bias, nbyte)) {
 888                                         /*
 889                                          * This bss-zeroing can fail if the ELF
 890                                          * file specifies odd protections. So
 891                                          * we don't check the return value
 892                                          */
 893                                 }
 894                         }
 895                 }
 896
 897                 if (elf_ppnt->p_flags & PF_R)
 898                         elf_prot |= PROT_READ;
 899                 if (elf_ppnt->p_flags & PF_W)
 900                         elf_prot |= PROT_WRITE;
 901                 if (elf_ppnt->p_flags & PF_X)
 902                         elf_prot |= PROT_EXEC;
 903
 904                 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
 905
 906                 vaddr = elf_ppnt->p_vaddr;
 907                 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
 908                         elf_flags |= MAP_FIXED;
 909                 } else if (loc->elf_ex.e_type == ET_DYN) {
 910                         /* Try and get dynamic programs out of the way of the
 911                          * default mmap base, as well as whatever program they
 912                          * might try to exec.  This is because the brk will
 913                          * follow the loader, and is not movable.  */
 914 #ifdef CONFIG_X86
 915                         load_bias = 0;
 916 #else
 917                         load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
 918 #endif
 919                 }
 920
 921                 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
 922                                 elf_prot, elf_flags,0);
 923                 if (BAD_ADDR(error)) {
 924                         send_sig(SIGKILL, current, 0);
 925                         retval = IS_ERR((void *)error) ?
 926                                 PTR_ERR((void*)error) : -EINVAL;
 927                         goto out_free_dentry;
 928                 }
 929
 930                 if (!load_addr_set) {
 931                         load_addr_set = 1;
 932                         load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
 933                         if (loc->elf_ex.e_type == ET_DYN) {
 934                                 load_bias += error -
 935                                              ELF_PAGESTART(load_bias + vaddr);
 936                                 load_addr += load_bias;
 937                                 reloc_func_desc = load_bias;
 938                         }
 939                 }
 940                 k = elf_ppnt->p_vaddr;
 941                 if (k < start_code)
 942                         start_code = k;
 943                 if (start_data < k)
 944                         start_data = k;
 945
 946                 /*
 947                  * Check to see if the section's size will overflow the
 948                  * allowed task size. Note that p_filesz must always be
 949                  * <= p_memsz so it is only necessary to check p_memsz.
 950                  */
 951                 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
 952                     elf_ppnt->p_memsz > TASK_SIZE ||
 953                     TASK_SIZE - elf_ppnt->p_memsz < k) {
 954                         /* set_brk can never work. Avoid overflows. */
 955                         send_sig(SIGKILL, current, 0);
 956                         retval = -EINVAL;
 957                         goto out_free_dentry;
 958                 }
 959
 960                 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
 961
 962                 if (k > elf_bss)
 963                         elf_bss = k;
 964                 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
 965                         end_code = k;
 966                 if (end_data < k)
 967                         end_data = k;
 968                 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
 969                 if (k > elf_brk)
 970                         elf_brk = k;
 971         }
 972
 973         loc->elf_ex.e_entry += load_bias;
 974         elf_bss += load_bias;
 975         elf_brk += load_bias;
 976         start_code += load_bias;
 977         end_code += load_bias;
 978         start_data += load_bias;
 979         end_data += load_bias;
 980
 981         /* Calling set_brk effectively mmaps the pages that we need
 982          * for the bss and break sections.  We must do this before
 983          * mapping in the interpreter, to make sure it doesn't wind
 984          * up getting placed where the bss needs to go.
 985          */
 986         retval = set_brk(elf_bss, elf_brk);
 987         if (retval) {
 988                 send_sig(SIGKILL, current, 0);
 989                 goto out_free_dentry;
 990         }
 991         if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
 992                 send_sig(SIGSEGV, current, 0);
 993                 retval = -EFAULT; /* Nobody gets to see this, but.. */
 994                 goto out_free_dentry;
 995         }
 996
 997         if (elf_interpreter) {
 998                 if (interpreter_type == INTERPRETER_AOUT) {
 999                         elf_entry = load_aout_interp(&loc->interp_ex,
1000                                                      interpreter);
1001                 } else {
1002                         unsigned long uninitialized_var(interp_map_addr);
1003
1004                         elf_entry = load_elf_interp(&loc->interp_elf_ex,
1005                                                     interpreter,
1006                                                     &interp_map_addr,
1007                                                     load_bias);
1008                         if (!BAD_ADDR(elf_entry)) {
1009                                 /*
1010                                  * load_elf_interp() returns relocation
1011                                  * adjustment
1012                                  */
1013                                 interp_load_addr = elf_entry;
1014                                 elf_entry += loc->interp_elf_ex.e_entry;
1015                         }
1016                 }
1017                 if (BAD_ADDR(elf_entry)) {
1018                         force_sig(SIGSEGV, current);
1019                         retval = IS_ERR((void *)elf_entry) ?
1020                                         (int)elf_entry : -EINVAL;
1021                         goto out_free_dentry;
1022                 }
1023                 reloc_func_desc = interp_load_addr;
1024
1025                 allow_write_access(interpreter);
1026                 fput(interpreter);
1027                 kfree(elf_interpreter);
1028         } else {
1029                 elf_entry = loc->elf_ex.e_entry;
1030                 if (BAD_ADDR(elf_entry)) {
1031                         force_sig(SIGSEGV, current);
1032                         retval = -EINVAL;
1033                         goto out_free_dentry;
1034                 }
1035         }
1036
1037         kfree(elf_phdata);
1038
1039         if (interpreter_type != INTERPRETER_AOUT)
1040                 sys_close(elf_exec_fileno);
1041
1042         set_binfmt(&elf_format);
1043
1044 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
1045         retval = arch_setup_additional_pages(bprm, executable_stack);
1046         if (retval < 0) {
1047                 send_sig(SIGKILL, current, 0);
1048                 goto out;
1049         }
1050 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
1051
1052         compute_creds(bprm);
1053         current->flags &= ~PF_FORKNOEXEC;
1054         create_elf_tables(bprm, &loc->elf_ex,
1055                           (interpreter_type == INTERPRETER_AOUT),
1056                           load_addr, interp_load_addr);
1057         /* N.B. passed_fileno might not be initialized? */
1058         if (interpreter_type == INTERPRETER_AOUT)
1059                 current->mm->arg_start += strlen(passed_fileno) + 1;
1060         current->mm->end_code = end_code;
1061         current->mm->start_code = start_code;
1062         current->mm->start_data = start_data;
1063         current->mm->end_data = end_data;
1064         current->mm->start_stack = bprm->p;
1065
1066         if (current->personality & MMAP_PAGE_ZERO) {
1067                 /* Why this, you ask???  Well SVr4 maps page 0 as read-only,
1068                    and some applications "depend" upon this behavior.
1069                    Since we do not have the power to recompile these, we
1070                    emulate the SVr4 behavior. Sigh. */
1071                 down_write(&current->mm->mmap_sem);
1072                 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
1073                                 MAP_FIXED | MAP_PRIVATE, 0);
1074                 up_write(&current->mm->mmap_sem);
1075         }
1076
1077 #ifdef ELF_PLAT_INIT
1078         /*
1079          * The ABI may specify that certain registers be set up in special
1080          * ways (on i386 %edx is the address of a DT_FINI function, for
1081          * example.  In addition, it may also specify (eg, PowerPC64 ELF)
1082          * that the e_entry field is the address of the function descriptor
1083          * for the startup routine, rather than the address of the startup
1084          * routine itself.  This macro performs whatever initialization to
1085          * the regs structure is required as well as any relocations to the
1086          * function descriptor entries when executing dynamically links apps.
1087          */
1088         ELF_PLAT_INIT(regs, reloc_func_desc);
1089 #endif
1090
1091         start_thread(regs, elf_entry, bprm->p);
1092         if (unlikely(current->ptrace & PT_PTRACED)) {
1093                 if (current->ptrace & PT_TRACE_EXEC)
1094                         ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
1095                 else
1096                         send_sig(SIGTRAP, current, 0);
1097         }
1098         retval = 0;
1099 out:
1100         kfree(loc);
1101 out_ret:
1102         return retval;
1103
1104         /* error cleanup */
1105 out_free_dentry:
1106         allow_write_access(interpreter);
1107         if (interpreter)
1108                 fput(interpreter);
1109 out_free_interp:
1110         kfree(elf_interpreter);
1111 out_free_file:
1112         sys_close(elf_exec_fileno);
1113 out_free_fh:
1114         if (files)
1115                 reset_files_struct(current, files);
1116 out_free_ph:
1117         kfree(elf_phdata);
1118         goto out;
1119 }
1120
1121 /* This is really simpleminded and specialized - we are loading an
1122    a.out library that is given an ELF header. */
1123 static int load_elf_library(struct file *file)
1124 {
1125         struct elf_phdr *elf_phdata;
1126         struct elf_phdr *eppnt;
1127         unsigned long elf_bss, bss, len;
1128         int retval, error, i, j;
1129         struct elfhdr elf_ex;
1130
1131         error = -ENOEXEC;
1132         retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1133         if (retval != sizeof(elf_ex))
1134                 goto out;
1135
1136         if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1137                 goto out;
1138
1139         /* First of all, some simple consistency checks */
1140         if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1141             !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1142                 goto out;
1143
1144         /* Now read in all of the header information */
1145
1146         j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1147         /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1148
1149         error = -ENOMEM;
1150         elf_phdata = kmalloc(j, GFP_KERNEL);
1151         if (!elf_phdata)
1152                 goto out;
1153
1154         eppnt = elf_phdata;
1155         error = -ENOEXEC;
1156         retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1157         if (retval != j)
1158                 goto out_free_ph;
1159
1160         for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1161                 if ((eppnt + i)->p_type == PT_LOAD)
1162                         j++;
1163         if (j != 1)
1164                 goto out_free_ph;
1165
1166         while (eppnt->p_type != PT_LOAD)
1167                 eppnt++;
1168
1169         /* Now use mmap to map the library into memory. */
1170         down_write(&current->mm->mmap_sem);
1171         error = do_mmap(file,
1172                         ELF_PAGESTART(eppnt->p_vaddr),
1173                         (eppnt->p_filesz +
1174                          ELF_PAGEOFFSET(eppnt->p_vaddr)),
1175                         PROT_READ | PROT_WRITE | PROT_EXEC,
1176                         MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1177                         (eppnt->p_offset -
1178                          ELF_PAGEOFFSET(eppnt->p_vaddr)));
1179         up_write(&current->mm->mmap_sem);
1180         if (error != ELF_PAGESTART(eppnt->p_vaddr))
1181                 goto out_free_ph;
1182
1183         elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1184         if (padzero(elf_bss)) {
1185                 error = -EFAULT;
1186                 goto out_free_ph;
1187         }
1188
1189         len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1190                             ELF_MIN_ALIGN - 1);
1191         bss = eppnt->p_memsz + eppnt->p_vaddr;
1192         if (bss > len) {
1193                 down_write(&current->mm->mmap_sem);
1194                 do_brk(len, bss - len);
1195                 up_write(&current->mm->mmap_sem);
1196         }
1197         error = 0;
1198
1199 out_free_ph:
1200         kfree(elf_phdata);
1201 out:
1202         return error;
1203 }
1204
1205 /*
1206  * Note that some platforms still use traditional core dumps and not
1207  * the ELF core dump.  Each platform can select it as appropriate.
1208  */
1209 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1210
1211 /*
1212  * ELF core dumper
1213  *
1214  * Modelled on fs/exec.c:aout_core_dump()
1215  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1216  */
1217 /*
1218  * These are the only things you should do on a core-file: use only these
1219  * functions to write out all the necessary info.
1220  */
1221 static int dump_write(struct file *file, const void *addr, int nr)
1222 {
1223         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1224 }
1225
1226 static int dump_seek(struct file *file, loff_t off)
1227 {
1228         if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1229                 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1230                         return 0;
1231         } else {
1232                 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1233                 if (!buf)
1234                         return 0;
1235                 while (off > 0) {
1236                         unsigned long n = off;
1237                         if (n > PAGE_SIZE)
1238                                 n = PAGE_SIZE;
1239                         if (!dump_write(file, buf, n))
1240                                 return 0;
1241                         off -= n;
1242                 }
1243                 free_page((unsigned long)buf);
1244         }
1245         return 1;
1246 }
1247
1248 /*
1249  * Decide whether a segment is worth dumping; default is yes to be
1250  * sure (missing info is worse than too much; etc).
1251  * Personally I'd include everything, and use the coredump limit...
1252  *
1253  * I think we should skip something. But I am not sure how. H.J.
1254  */
1255 static int maydump(struct vm_area_struct *vma)
1256 {
1257         /* The vma can be set up to tell us the answer directly.  */
1258         if (vma->vm_flags & VM_ALWAYSDUMP)
1259                 return 1;
1260
1261         /* Do not dump I/O mapped devices or special mappings */
1262         if (vma->vm_flags & (VM_IO | VM_RESERVED))
1263                 return 0;
1264
1265         /* Dump shared memory only if mapped from an anonymous file. */
1266         if (vma->vm_flags & VM_SHARED)
1267                 return vma->vm_file->f_path.dentry->d_inode->i_nlink == 0;
1268
1269         /* If it hasn't been written to, don't write it out */
1270         if (!vma->anon_vma)
1271                 return 0;
1272
1273         return 1;
1274 }
1275
1276 /* An ELF note in memory */
1277 struct memelfnote
1278 {
1279         const char *name;
1280         int type;
1281         unsigned int datasz;
1282         void *data;
1283 };
1284
1285 static int notesize(struct memelfnote *en)
1286 {
1287         int sz;
1288
1289         sz = sizeof(struct elf_note);
1290         sz += roundup(strlen(en->name) + 1, 4);
1291         sz += roundup(en->datasz, 4);
1292
1293         return sz;
1294 }
1295
1296 #define DUMP_WRITE(addr, nr, foffset)   \
1297         do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1298
1299 static int alignfile(struct file *file, loff_t *foffset)
1300 {
1301         static const char buf[4] = { 0, };
1302         DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1303         return 1;
1304 }
1305
1306 static int writenote(struct memelfnote *men, struct file *file,
1307                         loff_t *foffset)
1308 {
1309         struct elf_note en;
1310         en.n_namesz = strlen(men->name) + 1;
1311         en.n_descsz = men->datasz;
1312         en.n_type = men->type;
1313
1314         DUMP_WRITE(&en, sizeof(en), foffset);
1315         DUMP_WRITE(men->name, en.n_namesz, foffset);
1316         if (!alignfile(file, foffset))
1317                 return 0;
1318         DUMP_WRITE(men->data, men->datasz, foffset);
1319         if (!alignfile(file, foffset))
1320                 return 0;
1321
1322         return 1;
1323 }
1324 #undef DUMP_WRITE
1325
1326 #define DUMP_WRITE(addr, nr)    \
1327         if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1328                 goto end_coredump;
1329 #define DUMP_SEEK(off)  \
1330         if (!dump_seek(file, (off))) \
1331                 goto end_coredump;
1332
1333 static void fill_elf_header(struct elfhdr *elf, int segs)
1334 {
1335         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1336         elf->e_ident[EI_CLASS] = ELF_CLASS;
1337         elf->e_ident[EI_DATA] = ELF_DATA;
1338         elf->e_ident[EI_VERSION] = EV_CURRENT;
1339         elf->e_ident[EI_OSABI] = ELF_OSABI;
1340         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1341
1342         elf->e_type = ET_CORE;
1343         elf->e_machine = ELF_ARCH;
1344         elf->e_version = EV_CURRENT;
1345         elf->e_entry = 0;
1346         elf->e_phoff = sizeof(struct elfhdr);
1347         elf->e_shoff = 0;
1348         elf->e_flags = ELF_CORE_EFLAGS;
1349         elf->e_ehsize = sizeof(struct elfhdr);
1350         elf->e_phentsize = sizeof(struct elf_phdr);
1351         elf->e_phnum = segs;
1352         elf->e_shentsize = 0;
1353         elf->e_shnum = 0;
1354         elf->e_shstrndx = 0;
1355         return;
1356 }
1357
1358 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1359 {
1360         phdr->p_type = PT_NOTE;
1361         phdr->p_offset = offset;
1362         phdr->p_vaddr = 0;
1363         phdr->p_paddr = 0;
1364         phdr->p_filesz = sz;
1365         phdr->p_memsz = 0;
1366         phdr->p_flags = 0;
1367         phdr->p_align = 0;
1368         return;
1369 }
1370
1371 static void fill_note(struct memelfnote *note, const char *name, int type,
1372                 unsigned int sz, void *data)
1373 {
1374         note->name = name;
1375         note->type = type;
1376         note->datasz = sz;
1377         note->data = data;
1378         return;
1379 }
1380
1381 /*
1382  * fill up all the fields in prstatus from the given task struct, except
1383  * registers which need to be filled up separately.
1384  */
1385 static void fill_prstatus(struct elf_prstatus *prstatus,
1386                 struct task_struct *p, long signr)
1387 {
1388         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1389         prstatus->pr_sigpend = p->pending.signal.sig[0];
1390         prstatus->pr_sighold = p->blocked.sig[0];
1391         prstatus->pr_pid = p->pid;
1392         prstatus->pr_ppid = p->parent->pid;
1393         prstatus->pr_pgrp = process_group(p);
1394         prstatus->pr_sid = process_session(p);
1395         if (thread_group_leader(p)) {
1396                 /*
1397                  * This is the record for the group leader.  Add in the
1398                  * cumulative times of previous dead threads.  This total
1399                  * won't include the time of each live thread whose state
1400                  * is included in the core dump.  The final total reported
1401                  * to our parent process when it calls wait4 will include
1402                  * those sums as well as the little bit more time it takes
1403                  * this and each other thread to finish dying after the
1404                  * core dump synchronization phase.
1405                  */
1406                 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1407                                    &prstatus->pr_utime);
1408                 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1409                                    &prstatus->pr_stime);
1410         } else {
1411                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1412                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1413         }
1414         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1415         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1416 }
1417
1418 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1419                        struct mm_struct *mm)
1420 {
1421         unsigned int i, len;
1422
1423         /* first copy the parameters from user space */
1424         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1425
1426         len = mm->arg_end - mm->arg_start;
1427         if (len >= ELF_PRARGSZ)
1428                 len = ELF_PRARGSZ-1;
1429         if (copy_from_user(&psinfo->pr_psargs,
1430                            (const char __user *)mm->arg_start, len))
1431                 return -EFAULT;
1432         for(i = 0; i < len; i++)
1433                 if (psinfo->pr_psargs[i] == 0)
1434                         psinfo->pr_psargs[i] = ' ';
1435         psinfo->pr_psargs[len] = 0;
1436
1437         psinfo->pr_pid = p->pid;
1438         psinfo->pr_ppid = p->parent->pid;
1439         psinfo->pr_pgrp = process_group(p);
1440         psinfo->pr_sid = process_session(p);
1441
1442         i = p->state ? ffz(~p->state) + 1 : 0;
1443         psinfo->pr_state = i;
1444         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1445         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1446         psinfo->pr_nice = task_nice(p);
1447         psinfo->pr_flag = p->flags;
1448         SET_UID(psinfo->pr_uid, p->uid);
1449         SET_GID(psinfo->pr_gid, p->gid);
1450         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1451
1452         return 0;
1453 }
1454
1455 /* Here is the structure in which status of each thread is captured. */
1456 struct elf_thread_status
1457 {
1458         struct list_head list;
1459         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1460         elf_fpregset_t fpu;             /* NT_PRFPREG */
1461         struct task_struct *thread;
1462 #ifdef ELF_CORE_COPY_XFPREGS
1463         elf_fpxregset_t xfpu;           /* NT_PRXFPREG */
1464 #endif
1465         struct memelfnote notes[3];
1466         int num_notes;
1467 };
1468
1469 /*
1470  * In order to add the specific thread information for the elf file format,
1471  * we need to keep a linked list of every threads pr_status and then create
1472  * a single section for them in the final core file.
1473  */
1474 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1475 {
1476         int sz = 0;
1477         struct task_struct *p = t->thread;
1478         t->num_notes = 0;
1479
1480         fill_prstatus(&t->prstatus, p, signr);
1481         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1482
1483         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1484                   &(t->prstatus));
1485         t->num_notes++;
1486         sz += notesize(&t->notes[0]);
1487
1488         if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1489                                                                 &t->fpu))) {
1490                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1491                           &(t->fpu));
1492                 t->num_notes++;
1493                 sz += notesize(&t->notes[1]);
1494         }
1495
1496 #ifdef ELF_CORE_COPY_XFPREGS
1497         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1498                 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1499                           &t->xfpu);
1500                 t->num_notes++;
1501                 sz += notesize(&t->notes[2]);
1502         }
1503 #endif
1504         return sz;
1505 }
1506
1507 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1508                                         struct vm_area_struct *gate_vma)
1509 {
1510         struct vm_area_struct *ret = tsk->mm->mmap;
1511
1512         if (ret)
1513                 return ret;
1514         return gate_vma;
1515 }
1516 /*
1517  * Helper function for iterating across a vma list.  It ensures that the caller
1518  * will visit `gate_vma' prior to terminating the search.
1519  */
1520 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1521                                         struct vm_area_struct *gate_vma)
1522 {
1523         struct vm_area_struct *ret;
1524
1525         ret = this_vma->vm_next;
1526         if (ret)
1527                 return ret;
1528         if (this_vma == gate_vma)
1529                 return NULL;
1530         return gate_vma;
1531 }
1532
1533 /*
1534  * Actual dumper
1535  *
1536  * This is a two-pass process; first we find the offsets of the bits,
1537  * and then they are actually written out.  If we run out of core limit
1538  * we just truncate.
1539  */
1540 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file)
1541 {
1542 #define NUM_NOTES       6
1543         int has_dumped = 0;
1544         mm_segment_t fs;
1545         int segs;
1546         size_t size = 0;
1547         int i;
1548         struct vm_area_struct *vma, *gate_vma;
1549         struct elfhdr *elf = NULL;
1550         loff_t offset = 0, dataoff, foffset;
1551         unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1552         int numnote;
1553         struct memelfnote *notes = NULL;
1554         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1555         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1556         struct task_struct *g, *p;
1557         LIST_HEAD(thread_list);
1558         struct list_head *t;
1559         elf_fpregset_t *fpu = NULL;
1560 #ifdef ELF_CORE_COPY_XFPREGS
1561         elf_fpxregset_t *xfpu = NULL;
1562 #endif
1563         int thread_status_size = 0;
1564         elf_addr_t *auxv;
1565 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1566         int extra_notes_size;
1567 #endif
1568
1569         /*
1570          * We no longer stop all VM operations.
1571          *
1572          * This is because those proceses that could possibly change map_count
1573          * or the mmap / vma pages are now blocked in do_exit on current
1574          * finishing this core dump.
1575          *
1576          * Only ptrace can touch these memory addresses, but it doesn't change
1577          * the map_count or the pages allocated. So no possibility of crashing
1578          * exists while dumping the mm->vm_next areas to the core file.
1579          */
1580
1581         /* alloc memory for large data structures: too large to be on stack */
1582         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1583         if (!elf)
1584                 goto cleanup;
1585         prstatus = kmalloc(sizeof(*prstatus), GFP_KERNEL);
1586         if (!prstatus)
1587                 goto cleanup;
1588         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1589         if (!psinfo)
1590                 goto cleanup;
1591         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1592         if (!notes)
1593                 goto cleanup;
1594         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1595         if (!fpu)
1596                 goto cleanup;
1597 #ifdef ELF_CORE_COPY_XFPREGS
1598         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1599         if (!xfpu)
1600                 goto cleanup;
1601 #endif
1602
1603         if (signr) {
1604                 struct elf_thread_status *tmp;
1605                 rcu_read_lock();
1606                 do_each_thread(g,p)
1607                         if (current->mm == p->mm && current != p) {
1608                                 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1609                                 if (!tmp) {
1610                                         rcu_read_unlock();
1611                                         goto cleanup;
1612                                 }
1613                                 tmp->thread = p;
1614                                 list_add(&tmp->list, &thread_list);
1615                         }
1616                 while_each_thread(g,p);
1617                 rcu_read_unlock();
1618                 list_for_each(t, &thread_list) {
1619                         struct elf_thread_status *tmp;
1620                         int sz;
1621
1622                         tmp = list_entry(t, struct elf_thread_status, list);
1623                         sz = elf_dump_thread_status(signr, tmp);
1624                         thread_status_size += sz;
1625                 }
1626         }
1627         /* now collect the dump for the current */
1628         memset(prstatus, 0, sizeof(*prstatus));
1629         fill_prstatus(prstatus, current, signr);
1630         elf_core_copy_regs(&prstatus->pr_reg, regs);
1631
1632         segs = current->mm->map_count;
1633 #ifdef ELF_CORE_EXTRA_PHDRS
1634         segs += ELF_CORE_EXTRA_PHDRS;
1635 #endif
1636
1637         gate_vma = get_gate_vma(current);
1638         if (gate_vma != NULL)
1639                 segs++;
1640
1641         /* Set up header */
1642         fill_elf_header(elf, segs + 1); /* including notes section */
1643
1644         has_dumped = 1;
1645         current->flags |= PF_DUMPCORE;
1646
1647         /*
1648          * Set up the notes in similar form to SVR4 core dumps made
1649          * with info from their /proc.
1650          */
1651
1652         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1653         fill_psinfo(psinfo, current->group_leader, current->mm);
1654         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1655
1656         numnote = 2;
1657
1658         auxv = (elf_addr_t *)current->mm->saved_auxv;
1659
1660         i = 0;
1661         do
1662                 i += 2;
1663         while (auxv[i - 2] != AT_NULL);
1664         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1665                   i * sizeof(elf_addr_t), auxv);
1666
1667         /* Try to dump the FPU. */
1668         if ((prstatus->pr_fpvalid =
1669              elf_core_copy_task_fpregs(current, regs, fpu)))
1670                 fill_note(notes + numnote++,
1671                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1672 #ifdef ELF_CORE_COPY_XFPREGS
1673         if (elf_core_copy_task_xfpregs(current, xfpu))
1674                 fill_note(notes + numnote++,
1675                           "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1676 #endif
1677
1678         fs = get_fs();
1679         set_fs(KERNEL_DS);
1680
1681         DUMP_WRITE(elf, sizeof(*elf));
1682         offset += sizeof(*elf);                         /* Elf header */
1683         offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1684         foffset = offset;
1685
1686         /* Write notes phdr entry */
1687         {
1688                 struct elf_phdr phdr;
1689                 int sz = 0;
1690
1691                 for (i = 0; i < numnote; i++)
1692                         sz += notesize(notes + i);
1693
1694                 sz += thread_status_size;
1695
1696 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1697                 extra_notes_size = ELF_CORE_EXTRA_NOTES_SIZE;
1698                 sz += extra_notes_size;
1699 #endif
1700
1701                 fill_elf_note_phdr(&phdr, sz, offset);
1702                 offset += sz;
1703                 DUMP_WRITE(&phdr, sizeof(phdr));
1704         }
1705
1706         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1707
1708         /* Write program headers for segments dump */
1709         for (vma = first_vma(current, gate_vma); vma != NULL;
1710                         vma = next_vma(vma, gate_vma)) {
1711                 struct elf_phdr phdr;
1712                 size_t sz;
1713
1714                 sz = vma->vm_end - vma->vm_start;
1715
1716                 phdr.p_type = PT_LOAD;
1717                 phdr.p_offset = offset;
1718                 phdr.p_vaddr = vma->vm_start;
1719                 phdr.p_paddr = 0;
1720                 phdr.p_filesz = maydump(vma) ? sz : 0;
1721                 phdr.p_memsz = sz;
1722                 offset += phdr.p_filesz;
1723                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1724                 if (vma->vm_flags & VM_WRITE)
1725                         phdr.p_flags |= PF_W;
1726                 if (vma->vm_flags & VM_EXEC)
1727                         phdr.p_flags |= PF_X;
1728                 phdr.p_align = ELF_EXEC_PAGESIZE;
1729
1730                 DUMP_WRITE(&phdr, sizeof(phdr));
1731         }
1732
1733 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1734         ELF_CORE_WRITE_EXTRA_PHDRS;
1735 #endif
1736
1737         /* write out the notes section */
1738         for (i = 0; i < numnote; i++)
1739                 if (!writenote(notes + i, file, &foffset))
1740                         goto end_coredump;
1741
1742 #ifdef ELF_CORE_WRITE_EXTRA_NOTES
1743         ELF_CORE_WRITE_EXTRA_NOTES;
1744         foffset += extra_notes_size;
1745 #endif
1746
1747         /* write out the thread status notes section */
1748         list_for_each(t, &thread_list) {
1749                 struct elf_thread_status *tmp =
1750                                 list_entry(t, struct elf_thread_status, list);
1751
1752                 for (i = 0; i < tmp->num_notes; i++)
1753                         if (!writenote(&tmp->notes[i], file, &foffset))
1754                                 goto end_coredump;
1755         }
1756
1757         /* Align to page */
1758         DUMP_SEEK(dataoff - foffset);
1759
1760         for (vma = first_vma(current, gate_vma); vma != NULL;
1761                         vma = next_vma(vma, gate_vma)) {
1762                 unsigned long addr;
1763
1764                 if (!maydump(vma))
1765                         continue;
1766
1767                 for (addr = vma->vm_start;
1768                      addr < vma->vm_end;
1769                      addr += PAGE_SIZE) {
1770                         struct page *page;
1771                         struct vm_area_struct *vma;
1772
1773                         if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1774                                                 &page, &vma) <= 0) {
1775                                 DUMP_SEEK(PAGE_SIZE);
1776                         } else {
1777                                 if (page == ZERO_PAGE(addr)) {
1778                                         if (!dump_seek(file, PAGE_SIZE)) {
1779                                                 page_cache_release(page);
1780                                                 goto end_coredump;
1781                                         }
1782                                 } else {
1783                                         void *kaddr;
1784                                         flush_cache_page(vma, addr,
1785                                                          page_to_pfn(page));
1786                                         kaddr = kmap(page);
1787                                         if ((size += PAGE_SIZE) > limit ||
1788                                             !dump_write(file, kaddr,
1789                                             PAGE_SIZE)) {
1790                                                 kunmap(page);
1791                                                 page_cache_release(page);
1792                                                 goto end_coredump;
1793                                         }
1794                                         kunmap(page);
1795                                 }
1796                                 page_cache_release(page);
1797                         }
1798                 }
1799         }
1800
1801 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1802         ELF_CORE_WRITE_EXTRA_DATA;
1803 #endif
1804
1805 end_coredump:
1806         set_fs(fs);
1807
1808 cleanup:
1809         while (!list_empty(&thread_list)) {
1810                 struct list_head *tmp = thread_list.next;
1811                 list_del(tmp);
1812                 kfree(list_entry(tmp, struct elf_thread_status, list));
1813         }
1814
1815         kfree(elf);
1816         kfree(prstatus);
1817         kfree(psinfo);
1818         kfree(notes);
1819         kfree(fpu);
1820 #ifdef ELF_CORE_COPY_XFPREGS
1821         kfree(xfpu);
1822 #endif
1823         return has_dumped;
1824 #undef NUM_NOTES
1825 }
1826
1827 #endif          /* USE_ELF_CORE_DUMP */
1828
1829 static int __init init_elf_binfmt(void)
1830 {
1831         return register_binfmt(&elf_format);
1832 }
1833
1834 static void __exit exit_elf_binfmt(void)
1835 {
1836         /* Remove the COFF and ELF loaders. */
1837         unregister_binfmt(&elf_format);
1838 }
1839
1840 core_initcall(init_elf_binfmt);
1841 module_exit(exit_elf_binfmt);
1842 MODULE_LICENSE("GPL");