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