fs/binfmt_elf_fdpic.c

   1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
   2  *
   3  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  * Derived from binfmt_elf.c
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14
  15 #include <linux/fs.h>
  16 #include <linux/stat.h>
  17 #include <linux/sched.h>
  18 #include <linux/mm.h>
  19 #include <linux/mman.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/slab.h>
  27 #include <linux/pagemap.h>
  28 #include <linux/highmem.h>
  29 #include <linux/highuid.h>
  30 #include <linux/personality.h>
  31 #include <linux/ptrace.h>
  32 #include <linux/init.h>
  33 #include <linux/elf.h>
  34 #include <linux/elf-fdpic.h>
  35 #include <linux/elfcore.h>
  36
  37 #include <asm/uaccess.h>
  38 #include <asm/param.h>
  39 #include <asm/pgalloc.h>
  40
  41 typedef char *elf_caddr_t;
  42
  43 #if 0
  44 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  45 #else
  46 #define kdebug(fmt, ...) do {} while(0)
  47 #endif
  48
  49 #if 0
  50 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  51 #else
  52 #define kdcore(fmt, ...) do {} while(0)
  53 #endif
  54
  55 MODULE_LICENSE("GPL");
  56
  57 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
  58 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  59 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  60                               struct mm_struct *, const char *);
  61
  62 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  63                                    struct elf_fdpic_params *,
  64                                    struct elf_fdpic_params *);
  65
  66 #ifndef CONFIG_MMU
  67 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
  68                                             unsigned long *);
  69 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  70                                                    struct file *,
  71                                                    struct mm_struct *);
  72 #endif
  73
  74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  75                                              struct file *, struct mm_struct *);
  76
  77 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  78 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit);
  79 #endif
  80
  81 static struct linux_binfmt elf_fdpic_format = {
  82         .module         = THIS_MODULE,
  83         .load_binary    = load_elf_fdpic_binary,
  84 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  85         .core_dump      = elf_fdpic_core_dump,
  86 #endif
  87         .min_coredump   = ELF_EXEC_PAGESIZE,
  88 };
  89
  90 static int __init init_elf_fdpic_binfmt(void)
  91 {
  92         return register_binfmt(&elf_fdpic_format);
  93 }
  94
  95 static void __exit exit_elf_fdpic_binfmt(void)
  96 {
  97         unregister_binfmt(&elf_fdpic_format);
  98 }
  99
 100 core_initcall(init_elf_fdpic_binfmt);
 101 module_exit(exit_elf_fdpic_binfmt);
 102
 103 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
 104 {
 105         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 106                 return 0;
 107         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 108                 return 0;
 109         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
 110                 return 0;
 111         if (!file->f_op || !file->f_op->mmap)
 112                 return 0;
 113         return 1;
 114 }
 115
 116 /*****************************************************************************/
 117 /*
 118  * read the program headers table into memory
 119  */
 120 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 121                                  struct file *file)
 122 {
 123         struct elf32_phdr *phdr;
 124         unsigned long size;
 125         int retval, loop;
 126
 127         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 128                 return -ENOMEM;
 129         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 130                 return -ENOMEM;
 131
 132         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 133         params->phdrs = kmalloc(size, GFP_KERNEL);
 134         if (!params->phdrs)
 135                 return -ENOMEM;
 136
 137         retval = kernel_read(file, params->hdr.e_phoff,
 138                              (char *) params->phdrs, size);
 139         if (unlikely(retval != size))
 140                 return retval < 0 ? retval : -ENOEXEC;
 141
 142         /* determine stack size for this binary */
 143         phdr = params->phdrs;
 144         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 145                 if (phdr->p_type != PT_GNU_STACK)
 146                         continue;
 147
 148                 if (phdr->p_flags & PF_X)
 149                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 150                 else
 151                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 152
 153                 params->stack_size = phdr->p_memsz;
 154                 break;
 155         }
 156
 157         return 0;
 158 }
 159
 160 /*****************************************************************************/
 161 /*
 162  * load an fdpic binary into various bits of memory
 163  */
 164 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
 165                                  struct pt_regs *regs)
 166 {
 167         struct elf_fdpic_params exec_params, interp_params;
 168         struct elf_phdr *phdr;
 169         unsigned long stack_size, entryaddr;
 170 #ifndef CONFIG_MMU
 171         unsigned long fullsize;
 172 #endif
 173 #ifdef ELF_FDPIC_PLAT_INIT
 174         unsigned long dynaddr;
 175 #endif
 176         struct file *interpreter = NULL; /* to shut gcc up */
 177         char *interpreter_name = NULL;
 178         int executable_stack;
 179         int retval, i;
 180
 181         kdebug("____ LOAD %d ____", current->pid);
 182
 183         memset(&exec_params, 0, sizeof(exec_params));
 184         memset(&interp_params, 0, sizeof(interp_params));
 185
 186         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 187         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 188
 189         /* check that this is a binary we know how to deal with */
 190         retval = -ENOEXEC;
 191         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
 192                 goto error;
 193
 194         /* read the program header table */
 195         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 196         if (retval < 0)
 197                 goto error;
 198
 199         /* scan for a program header that specifies an interpreter */
 200         phdr = exec_params.phdrs;
 201
 202         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 203                 switch (phdr->p_type) {
 204                 case PT_INTERP:
 205                         retval = -ENOMEM;
 206                         if (phdr->p_filesz > PATH_MAX)
 207                                 goto error;
 208                         retval = -ENOENT;
 209                         if (phdr->p_filesz < 2)
 210                                 goto error;
 211
 212                         /* read the name of the interpreter into memory */
 213                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 214                         if (!interpreter_name)
 215                                 goto error;
 216
 217                         retval = kernel_read(bprm->file,
 218                                              phdr->p_offset,
 219                                              interpreter_name,
 220                                              phdr->p_filesz);
 221                         if (unlikely(retval != phdr->p_filesz)) {
 222                                 if (retval >= 0)
 223                                         retval = -ENOEXEC;
 224                                 goto error;
 225                         }
 226
 227                         retval = -ENOENT;
 228                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 229                                 goto error;
 230
 231                         kdebug("Using ELF interpreter %s", interpreter_name);
 232
 233                         /* replace the program with the interpreter */
 234                         interpreter = open_exec(interpreter_name);
 235                         retval = PTR_ERR(interpreter);
 236                         if (IS_ERR(interpreter)) {
 237                                 interpreter = NULL;
 238                                 goto error;
 239                         }
 240
 241                         /*
 242                          * If the binary is not readable then enforce
 243                          * mm->dumpable = 0 regardless of the interpreter's
 244                          * permissions.
 245                          */
 246                         if (file_permission(interpreter, MAY_READ) < 0)
 247                                 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
 248
 249                         retval = kernel_read(interpreter, 0, bprm->buf,
 250                                              BINPRM_BUF_SIZE);
 251                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
 252                                 if (retval >= 0)
 253                                         retval = -ENOEXEC;
 254                                 goto error;
 255                         }
 256
 257                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 258                         break;
 259
 260                 case PT_LOAD:
 261 #ifdef CONFIG_MMU
 262                         if (exec_params.load_addr == 0)
 263                                 exec_params.load_addr = phdr->p_vaddr;
 264 #endif
 265                         break;
 266                 }
 267
 268         }
 269
 270         if (elf_check_const_displacement(&exec_params.hdr))
 271                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 272
 273         /* perform insanity checks on the interpreter */
 274         if (interpreter_name) {
 275                 retval = -ELIBBAD;
 276                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
 277                         goto error;
 278
 279                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 280
 281                 /* read the interpreter's program header table */
 282                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 283                 if (retval < 0)
 284                         goto error;
 285         }
 286
 287         stack_size = exec_params.stack_size;
 288         if (stack_size < interp_params.stack_size)
 289                 stack_size = interp_params.stack_size;
 290
 291         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 292                 executable_stack = EXSTACK_ENABLE_X;
 293         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 294                 executable_stack = EXSTACK_DISABLE_X;
 295         else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 296                 executable_stack = EXSTACK_ENABLE_X;
 297         else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 298                 executable_stack = EXSTACK_DISABLE_X;
 299         else
 300                 executable_stack = EXSTACK_DEFAULT;
 301
 302         retval = -ENOEXEC;
 303         if (stack_size == 0)
 304                 goto error;
 305
 306         if (elf_check_const_displacement(&interp_params.hdr))
 307                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 308
 309         /* flush all traces of the currently running executable */
 310         retval = flush_old_exec(bprm);
 311         if (retval)
 312                 goto error;
 313
 314         /* there's now no turning back... the old userspace image is dead,
 315          * defunct, deceased, etc. after this point we have to exit via
 316          * error_kill */
 317         set_personality(PER_LINUX_FDPIC);
 318         set_binfmt(&elf_fdpic_format);
 319
 320         current->mm->start_code = 0;
 321         current->mm->end_code = 0;
 322         current->mm->start_stack = 0;
 323         current->mm->start_data = 0;
 324         current->mm->end_data = 0;
 325         current->mm->context.exec_fdpic_loadmap = 0;
 326         current->mm->context.interp_fdpic_loadmap = 0;
 327
 328         current->flags &= ~PF_FORKNOEXEC;
 329
 330 #ifdef CONFIG_MMU
 331         elf_fdpic_arch_lay_out_mm(&exec_params,
 332                                   &interp_params,
 333                                   &current->mm->start_stack,
 334                                   &current->mm->start_brk);
 335
 336         retval = setup_arg_pages(bprm, current->mm->start_stack,
 337                                  executable_stack);
 338         if (retval < 0) {
 339                 send_sig(SIGKILL, current, 0);
 340                 goto error_kill;
 341         }
 342 #endif
 343
 344         /* load the executable and interpreter into memory */
 345         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 346                                     "executable");
 347         if (retval < 0)
 348                 goto error_kill;
 349
 350         if (interpreter_name) {
 351                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 352                                             current->mm, "interpreter");
 353                 if (retval < 0) {
 354                         printk(KERN_ERR "Unable to load interpreter\n");
 355                         goto error_kill;
 356                 }
 357
 358                 allow_write_access(interpreter);
 359                 fput(interpreter);
 360                 interpreter = NULL;
 361         }
 362
 363 #ifdef CONFIG_MMU
 364         if (!current->mm->start_brk)
 365                 current->mm->start_brk = current->mm->end_data;
 366
 367         current->mm->brk = current->mm->start_brk =
 368                 PAGE_ALIGN(current->mm->start_brk);
 369
 370 #else
 371         /* create a stack and brk area big enough for everyone
 372          * - the brk heap starts at the bottom and works up
 373          * - the stack starts at the top and works down
 374          */
 375         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 376         if (stack_size < PAGE_SIZE * 2)
 377                 stack_size = PAGE_SIZE * 2;
 378
 379         down_write(&current->mm->mmap_sem);
 380         current->mm->start_brk = do_mmap(NULL, 0, stack_size,
 381                                          PROT_READ | PROT_WRITE | PROT_EXEC,
 382                                          MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
 383                                          0);
 384
 385         if (IS_ERR_VALUE(current->mm->start_brk)) {
 386                 up_write(&current->mm->mmap_sem);
 387                 retval = current->mm->start_brk;
 388                 current->mm->start_brk = 0;
 389                 goto error_kill;
 390         }
 391
 392         /* expand the stack mapping to use up the entire allocation granule */
 393         fullsize = kobjsize((char *) current->mm->start_brk);
 394         if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
 395                                     fullsize, 0, 0)))
 396                 stack_size = fullsize;
 397         up_write(&current->mm->mmap_sem);
 398
 399         current->mm->brk = current->mm->start_brk;
 400         current->mm->context.end_brk = current->mm->start_brk;
 401         current->mm->context.end_brk +=
 402                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 403         current->mm->start_stack = current->mm->start_brk + stack_size;
 404 #endif
 405
 406         compute_creds(bprm);
 407         current->flags &= ~PF_FORKNOEXEC;
 408         if (create_elf_fdpic_tables(bprm, current->mm,
 409                                     &exec_params, &interp_params) < 0)
 410                 goto error_kill;
 411
 412         kdebug("- start_code  %lx", current->mm->start_code);
 413         kdebug("- end_code    %lx", current->mm->end_code);
 414         kdebug("- start_data  %lx", current->mm->start_data);
 415         kdebug("- end_data    %lx", current->mm->end_data);
 416         kdebug("- start_brk   %lx", current->mm->start_brk);
 417         kdebug("- brk         %lx", current->mm->brk);
 418         kdebug("- start_stack %lx", current->mm->start_stack);
 419
 420 #ifdef ELF_FDPIC_PLAT_INIT
 421         /*
 422          * The ABI may specify that certain registers be set up in special
 423          * ways (on i386 %edx is the address of a DT_FINI function, for
 424          * example.  This macro performs whatever initialization to
 425          * the regs structure is required.
 426          */
 427         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 428         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 429                             dynaddr);
 430 #endif
 431
 432         /* everything is now ready... get the userspace context ready to roll */
 433         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 434         start_thread(regs, entryaddr, current->mm->start_stack);
 435
 436         if (unlikely(current->ptrace & PT_PTRACED)) {
 437                 if (current->ptrace & PT_TRACE_EXEC)
 438                         ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
 439                 else
 440                         send_sig(SIGTRAP, current, 0);
 441         }
 442
 443         retval = 0;
 444
 445 error:
 446         if (interpreter) {
 447                 allow_write_access(interpreter);
 448                 fput(interpreter);
 449         }
 450         kfree(interpreter_name);
 451         kfree(exec_params.phdrs);
 452         kfree(exec_params.loadmap);
 453         kfree(interp_params.phdrs);
 454         kfree(interp_params.loadmap);
 455         return retval;
 456
 457         /* unrecoverable error - kill the process */
 458 error_kill:
 459         send_sig(SIGSEGV, current, 0);
 460         goto error;
 461
 462 }
 463
 464 /*****************************************************************************/
 465 /*
 466  * present useful information to the program
 467  */
 468 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 469                                    struct mm_struct *mm,
 470                                    struct elf_fdpic_params *exec_params,
 471                                    struct elf_fdpic_params *interp_params)
 472 {
 473         unsigned long sp, csp, nitems;
 474         elf_caddr_t __user *argv, *envp;
 475         size_t platform_len = 0, len;
 476         char *k_platform;
 477         char __user *u_platform, *p;
 478         long hwcap;
 479         int loop;
 480
 481         /* we're going to shovel a whole load of stuff onto the stack */
 482 #ifdef CONFIG_MMU
 483         sp = bprm->p;
 484 #else
 485         sp = mm->start_stack;
 486
 487         /* stack the program arguments and environment */
 488         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 489                 return -EFAULT;
 490 #endif
 491
 492         /* get hold of platform and hardware capabilities masks for the machine
 493          * we are running on.  In some cases (Sparc), this info is impossible
 494          * to get, in others (i386) it is merely difficult.
 495          */
 496         hwcap = ELF_HWCAP;
 497         k_platform = ELF_PLATFORM;
 498         u_platform = NULL;
 499
 500         if (k_platform) {
 501                 platform_len = strlen(k_platform) + 1;
 502                 sp -= platform_len;
 503                 u_platform = (char __user *) sp;
 504                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 505                         return -EFAULT;
 506         }
 507
 508 #if defined(__i386__) && defined(CONFIG_SMP)
 509         /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 510          * by the processes running on the same package. One thing we can do is
 511          * to shuffle the initial stack for them.
 512          *
 513          * the conditionals here are unneeded, but kept in to make the code
 514          * behaviour the same as pre change unless we have hyperthreaded
 515          * processors. This keeps Mr Marcelo Person happier but should be
 516          * removed for 2.5
 517          */
 518         if (smp_num_siblings > 1)
 519                 sp = sp - ((current->pid % 64) << 7);
 520 #endif
 521
 522         sp &= ~7UL;
 523
 524         /* stack the load map(s) */
 525         len = sizeof(struct elf32_fdpic_loadmap);
 526         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 527         sp = (sp - len) & ~7UL;
 528         exec_params->map_addr = sp;
 529
 530         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 531                 return -EFAULT;
 532
 533         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 534
 535         if (interp_params->loadmap) {
 536                 len = sizeof(struct elf32_fdpic_loadmap);
 537                 len += sizeof(struct elf32_fdpic_loadseg) *
 538                         interp_params->loadmap->nsegs;
 539                 sp = (sp - len) & ~7UL;
 540                 interp_params->map_addr = sp;
 541
 542                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 543                                  len) != 0)
 544                         return -EFAULT;
 545
 546                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 547         }
 548
 549         /* force 16 byte _final_ alignment here for generality */
 550 #define DLINFO_ITEMS 13
 551
 552         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
 553 #ifdef DLINFO_ARCH_ITEMS
 554         nitems += DLINFO_ARCH_ITEMS;
 555 #endif
 556
 557         csp = sp;
 558         sp -= nitems * 2 * sizeof(unsigned long);
 559         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 560         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 561         sp -= 1 * sizeof(unsigned long);                /* argc */
 562
 563         csp -= sp & 15UL;
 564         sp -= sp & 15UL;
 565
 566         /* put the ELF interpreter info on the stack */
 567 #define NEW_AUX_ENT(nr, id, val)                                        \
 568         do {                                                            \
 569                 struct { unsigned long _id, _val; } __user *ent;        \
 570                                                                         \
 571                 ent = (void __user *) csp;                              \
 572                 __put_user((id), &ent[nr]._id);                         \
 573                 __put_user((val), &ent[nr]._val);                       \
 574         } while (0)
 575
 576         csp -= 2 * sizeof(unsigned long);
 577         NEW_AUX_ENT(0, AT_NULL, 0);
 578         if (k_platform) {
 579                 csp -= 2 * sizeof(unsigned long);
 580                 NEW_AUX_ENT(0, AT_PLATFORM,
 581                             (elf_addr_t) (unsigned long) u_platform);
 582         }
 583
 584         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 585         NEW_AUX_ENT( 0, AT_HWCAP,       hwcap);
 586         NEW_AUX_ENT( 1, AT_PAGESZ,      PAGE_SIZE);
 587         NEW_AUX_ENT( 2, AT_CLKTCK,      CLOCKS_PER_SEC);
 588         NEW_AUX_ENT( 3, AT_PHDR,        exec_params->ph_addr);
 589         NEW_AUX_ENT( 4, AT_PHENT,       sizeof(struct elf_phdr));
 590         NEW_AUX_ENT( 5, AT_PHNUM,       exec_params->hdr.e_phnum);
 591         NEW_AUX_ENT( 6, AT_BASE,        interp_params->elfhdr_addr);
 592         NEW_AUX_ENT( 7, AT_FLAGS,       0);
 593         NEW_AUX_ENT( 8, AT_ENTRY,       exec_params->entry_addr);
 594         NEW_AUX_ENT( 9, AT_UID,         (elf_addr_t) current->uid);
 595         NEW_AUX_ENT(10, AT_EUID,        (elf_addr_t) current->euid);
 596         NEW_AUX_ENT(11, AT_GID,         (elf_addr_t) current->gid);
 597         NEW_AUX_ENT(12, AT_EGID,        (elf_addr_t) current->egid);
 598
 599 #ifdef ARCH_DLINFO
 600         /* ARCH_DLINFO must come last so platform specific code can enforce
 601          * special alignment requirements on the AUXV if necessary (eg. PPC).
 602          */
 603         ARCH_DLINFO;
 604 #endif
 605 #undef NEW_AUX_ENT
 606
 607         /* allocate room for argv[] and envv[] */
 608         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 609         envp = (elf_caddr_t __user *) csp;
 610         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 611         argv = (elf_caddr_t __user *) csp;
 612
 613         /* stack argc */
 614         csp -= sizeof(unsigned long);
 615         __put_user(bprm->argc, (unsigned long __user *) csp);
 616
 617         BUG_ON(csp != sp);
 618
 619         /* fill in the argv[] array */
 620 #ifdef CONFIG_MMU
 621         current->mm->arg_start = bprm->p;
 622 #else
 623         current->mm->arg_start = current->mm->start_stack -
 624                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 625 #endif
 626
 627         p = (char __user *) current->mm->arg_start;
 628         for (loop = bprm->argc; loop > 0; loop--) {
 629                 __put_user((elf_caddr_t) p, argv++);
 630                 len = strnlen_user(p, MAX_ARG_STRLEN);
 631                 if (!len || len > MAX_ARG_STRLEN)
 632                         return -EINVAL;
 633                 p += len;
 634         }
 635         __put_user(NULL, argv);
 636         current->mm->arg_end = (unsigned long) p;
 637
 638         /* fill in the envv[] array */
 639         current->mm->env_start = (unsigned long) p;
 640         for (loop = bprm->envc; loop > 0; loop--) {
 641                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 642                 len = strnlen_user(p, MAX_ARG_STRLEN);
 643                 if (!len || len > MAX_ARG_STRLEN)
 644                         return -EINVAL;
 645                 p += len;
 646         }
 647         __put_user(NULL, envp);
 648         current->mm->env_end = (unsigned long) p;
 649
 650         mm->start_stack = (unsigned long) sp;
 651         return 0;
 652 }
 653
 654 /*****************************************************************************/
 655 /*
 656  * transfer the program arguments and environment from the holding pages onto
 657  * the stack
 658  */
 659 #ifndef CONFIG_MMU
 660 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 661                                             unsigned long *_sp)
 662 {
 663         unsigned long index, stop, sp;
 664         char *src;
 665         int ret = 0;
 666
 667         stop = bprm->p >> PAGE_SHIFT;
 668         sp = *_sp;
 669
 670         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 671                 src = kmap(bprm->page[index]);
 672                 sp -= PAGE_SIZE;
 673                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 674                         ret = -EFAULT;
 675                 kunmap(bprm->page[index]);
 676                 if (ret < 0)
 677                         goto out;
 678         }
 679
 680         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 681
 682 out:
 683         return ret;
 684 }
 685 #endif
 686
 687 /*****************************************************************************/
 688 /*
 689  * load the appropriate binary image (executable or interpreter) into memory
 690  * - we assume no MMU is available
 691  * - if no other PIC bits are set in params->hdr->e_flags
 692  *   - we assume that the LOADable segments in the binary are independently relocatable
 693  *   - we assume R/O executable segments are shareable
 694  * - else
 695  *   - we assume the loadable parts of the image to require fixed displacement
 696  *   - the image is not shareable
 697  */
 698 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 699                               struct file *file,
 700                               struct mm_struct *mm,
 701                               const char *what)
 702 {
 703         struct elf32_fdpic_loadmap *loadmap;
 704 #ifdef CONFIG_MMU
 705         struct elf32_fdpic_loadseg *mseg;
 706 #endif
 707         struct elf32_fdpic_loadseg *seg;
 708         struct elf32_phdr *phdr;
 709         unsigned long load_addr, stop;
 710         unsigned nloads, tmp;
 711         size_t size;
 712         int loop, ret;
 713
 714         /* allocate a load map table */
 715         nloads = 0;
 716         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 717                 if (params->phdrs[loop].p_type == PT_LOAD)
 718                         nloads++;
 719
 720         if (nloads == 0)
 721                 return -ELIBBAD;
 722
 723         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 724         loadmap = kzalloc(size, GFP_KERNEL);
 725         if (!loadmap)
 726                 return -ENOMEM;
 727
 728         params->loadmap = loadmap;
 729
 730         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 731         loadmap->nsegs = nloads;
 732
 733         load_addr = params->load_addr;
 734         seg = loadmap->segs;
 735
 736         /* map the requested LOADs into the memory space */
 737         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 738         case ELF_FDPIC_FLAG_CONSTDISP:
 739         case ELF_FDPIC_FLAG_CONTIGUOUS:
 740 #ifndef CONFIG_MMU
 741                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 742                 if (ret < 0)
 743                         return ret;
 744                 break;
 745 #endif
 746         default:
 747                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 748                 if (ret < 0)
 749                         return ret;
 750                 break;
 751         }
 752
 753         /* map the entry point */
 754         if (params->hdr.e_entry) {
 755                 seg = loadmap->segs;
 756                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 757                         if (params->hdr.e_entry >= seg->p_vaddr &&
 758                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 759                                 params->entry_addr =
 760                                         (params->hdr.e_entry - seg->p_vaddr) +
 761                                         seg->addr;
 762                                 break;
 763                         }
 764                 }
 765         }
 766
 767         /* determine where the program header table has wound up if mapped */
 768         stop = params->hdr.e_phoff;
 769         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 770         phdr = params->phdrs;
 771
 772         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 773                 if (phdr->p_type != PT_LOAD)
 774                         continue;
 775
 776                 if (phdr->p_offset > params->hdr.e_phoff ||
 777                     phdr->p_offset + phdr->p_filesz < stop)
 778                         continue;
 779
 780                 seg = loadmap->segs;
 781                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 782                         if (phdr->p_vaddr >= seg->p_vaddr &&
 783                             phdr->p_vaddr + phdr->p_filesz <=
 784                             seg->p_vaddr + seg->p_memsz) {
 785                                 params->ph_addr =
 786                                         (phdr->p_vaddr - seg->p_vaddr) +
 787                                         seg->addr +
 788                                         params->hdr.e_phoff - phdr->p_offset;
 789                                 break;
 790                         }
 791                 }
 792                 break;
 793         }
 794
 795         /* determine where the dynamic section has wound up if there is one */
 796         phdr = params->phdrs;
 797         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 798                 if (phdr->p_type != PT_DYNAMIC)
 799                         continue;
 800
 801                 seg = loadmap->segs;
 802                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 803                         if (phdr->p_vaddr >= seg->p_vaddr &&
 804                             phdr->p_vaddr + phdr->p_memsz <=
 805                             seg->p_vaddr + seg->p_memsz) {
 806                                 params->dynamic_addr =
 807                                         (phdr->p_vaddr - seg->p_vaddr) +
 808                                         seg->addr;
 809
 810                                 /* check the dynamic section contains at least
 811                                  * one item, and that the last item is a NULL
 812                                  * entry */
 813                                 if (phdr->p_memsz == 0 ||
 814                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 815                                         goto dynamic_error;
 816
 817                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 818                                 if (((Elf32_Dyn *)
 819                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
 820                                         goto dynamic_error;
 821                                 break;
 822                         }
 823                 }
 824                 break;
 825         }
 826
 827         /* now elide adjacent segments in the load map on MMU linux
 828          * - on uClinux the holes between may actually be filled with system
 829          *   stuff or stuff from other processes
 830          */
 831 #ifdef CONFIG_MMU
 832         nloads = loadmap->nsegs;
 833         mseg = loadmap->segs;
 834         seg = mseg + 1;
 835         for (loop = 1; loop < nloads; loop++) {
 836                 /* see if we have a candidate for merging */
 837                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 838                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 839                         if (load_addr == (seg->addr & PAGE_MASK)) {
 840                                 mseg->p_memsz +=
 841                                         load_addr -
 842                                         (mseg->addr + mseg->p_memsz);
 843                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 844                                 mseg->p_memsz += seg->p_memsz;
 845                                 loadmap->nsegs--;
 846                                 continue;
 847                         }
 848                 }
 849
 850                 mseg++;
 851                 if (mseg != seg)
 852                         *mseg = *seg;
 853         }
 854 #endif
 855
 856         kdebug("Mapped Object [%s]:", what);
 857         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 858         kdebug("- entry    : %lx", params->entry_addr);
 859         kdebug("- PHDR[]   : %lx", params->ph_addr);
 860         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 861         seg = loadmap->segs;
 862         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 863                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 864                        loop,
 865                        seg->addr, seg->addr + seg->p_memsz - 1,
 866                        seg->p_vaddr, seg->p_memsz);
 867
 868         return 0;
 869
 870 dynamic_error:
 871         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 872                what, file->f_path.dentry->d_inode->i_ino);
 873         return -ELIBBAD;
 874 }
 875
 876 /*****************************************************************************/
 877 /*
 878  * map a file with constant displacement under uClinux
 879  */
 880 #ifndef CONFIG_MMU
 881 static int elf_fdpic_map_file_constdisp_on_uclinux(
 882         struct elf_fdpic_params *params,
 883         struct file *file,
 884         struct mm_struct *mm)
 885 {
 886         struct elf32_fdpic_loadseg *seg;
 887         struct elf32_phdr *phdr;
 888         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 889         loff_t fpos;
 890         int loop, ret;
 891
 892         load_addr = params->load_addr;
 893         seg = params->loadmap->segs;
 894
 895         /* determine the bounds of the contiguous overall allocation we must
 896          * make */
 897         phdr = params->phdrs;
 898         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 899                 if (params->phdrs[loop].p_type != PT_LOAD)
 900                         continue;
 901
 902                 if (base > phdr->p_vaddr)
 903                         base = phdr->p_vaddr;
 904                 if (top < phdr->p_vaddr + phdr->p_memsz)
 905                         top = phdr->p_vaddr + phdr->p_memsz;
 906         }
 907
 908         /* allocate one big anon block for everything */
 909         mflags = MAP_PRIVATE;
 910         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 911                 mflags |= MAP_EXECUTABLE;
 912
 913         down_write(&mm->mmap_sem);
 914         maddr = do_mmap(NULL, load_addr, top - base,
 915                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 916         up_write(&mm->mmap_sem);
 917         if (IS_ERR_VALUE(maddr))
 918                 return (int) maddr;
 919
 920         if (load_addr != 0)
 921                 load_addr += PAGE_ALIGN(top - base);
 922
 923         /* and then load the file segments into it */
 924         phdr = params->phdrs;
 925         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 926                 if (params->phdrs[loop].p_type != PT_LOAD)
 927                         continue;
 928
 929                 fpos = phdr->p_offset;
 930
 931                 seg->addr = maddr + (phdr->p_vaddr - base);
 932                 seg->p_vaddr = phdr->p_vaddr;
 933                 seg->p_memsz = phdr->p_memsz;
 934
 935                 ret = file->f_op->read(file, (void *) seg->addr,
 936                                        phdr->p_filesz, &fpos);
 937                 if (ret < 0)
 938                         return ret;
 939
 940                 /* map the ELF header address if in this segment */
 941                 if (phdr->p_offset == 0)
 942                         params->elfhdr_addr = seg->addr;
 943
 944                 /* clear any space allocated but not loaded */
 945                 if (phdr->p_filesz < phdr->p_memsz)
 946                         clear_user((void *) (seg->addr + phdr->p_filesz),
 947                                    phdr->p_memsz - phdr->p_filesz);
 948
 949                 if (mm) {
 950                         if (phdr->p_flags & PF_X) {
 951                                 if (!mm->start_code) {
 952                                         mm->start_code = seg->addr;
 953                                         mm->end_code = seg->addr +
 954                                                 phdr->p_memsz;
 955                                 }
 956                         } else if (!mm->start_data) {
 957                                 mm->start_data = seg->addr;
 958 #ifndef CONFIG_MMU
 959                                 mm->end_data = seg->addr + phdr->p_memsz;
 960 #endif
 961                         }
 962
 963 #ifdef CONFIG_MMU
 964                         if (seg->addr + phdr->p_memsz > mm->end_data)
 965                                 mm->end_data = seg->addr + phdr->p_memsz;
 966 #endif
 967                 }
 968
 969                 seg++;
 970         }
 971
 972         return 0;
 973 }
 974 #endif
 975
 976 /*****************************************************************************/
 977 /*
 978  * map a binary by direct mmap() of the individual PT_LOAD segments
 979  */
 980 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
 981                                              struct file *file,
 982                                              struct mm_struct *mm)
 983 {
 984         struct elf32_fdpic_loadseg *seg;
 985         struct elf32_phdr *phdr;
 986         unsigned long load_addr, delta_vaddr;
 987         int loop, dvset;
 988
 989         load_addr = params->load_addr;
 990         delta_vaddr = 0;
 991         dvset = 0;
 992
 993         seg = params->loadmap->segs;
 994
 995         /* deal with each load segment separately */
 996         phdr = params->phdrs;
 997         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 998                 unsigned long maddr, disp, excess, excess1;
 999                 int prot = 0, flags;
1000
1001                 if (phdr->p_type != PT_LOAD)
1002                         continue;
1003
1004                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1005                        (unsigned long) phdr->p_vaddr,
1006                        (unsigned long) phdr->p_offset,
1007                        (unsigned long) phdr->p_filesz,
1008                        (unsigned long) phdr->p_memsz);
1009
1010                 /* determine the mapping parameters */
1011                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1012                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1013                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1014
1015                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1016                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1017                         flags |= MAP_EXECUTABLE;
1018
1019                 maddr = 0;
1020
1021                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1022                 case ELF_FDPIC_FLAG_INDEPENDENT:
1023                         /* PT_LOADs are independently locatable */
1024                         break;
1025
1026                 case ELF_FDPIC_FLAG_HONOURVADDR:
1027                         /* the specified virtual address must be honoured */
1028                         maddr = phdr->p_vaddr;
1029                         flags |= MAP_FIXED;
1030                         break;
1031
1032                 case ELF_FDPIC_FLAG_CONSTDISP:
1033                         /* constant displacement
1034                          * - can be mapped anywhere, but must be mapped as a
1035                          *   unit
1036                          */
1037                         if (!dvset) {
1038                                 maddr = load_addr;
1039                                 delta_vaddr = phdr->p_vaddr;
1040                                 dvset = 1;
1041                         } else {
1042                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1043                                 flags |= MAP_FIXED;
1044                         }
1045                         break;
1046
1047                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1048                         /* contiguity handled later */
1049                         break;
1050
1051                 default:
1052                         BUG();
1053                 }
1054
1055                 maddr &= PAGE_MASK;
1056
1057                 /* create the mapping */
1058                 disp = phdr->p_vaddr & ~PAGE_MASK;
1059                 down_write(&mm->mmap_sem);
1060                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1061                                 phdr->p_offset - disp);
1062                 up_write(&mm->mmap_sem);
1063
1064                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1065                        loop, phdr->p_memsz + disp, prot, flags,
1066                        phdr->p_offset - disp, maddr);
1067
1068                 if (IS_ERR_VALUE(maddr))
1069                         return (int) maddr;
1070
1071                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1072                     ELF_FDPIC_FLAG_CONTIGUOUS)
1073                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1074
1075                 seg->addr = maddr + disp;
1076                 seg->p_vaddr = phdr->p_vaddr;
1077                 seg->p_memsz = phdr->p_memsz;
1078
1079                 /* map the ELF header address if in this segment */
1080                 if (phdr->p_offset == 0)
1081                         params->elfhdr_addr = seg->addr;
1082
1083                 /* clear the bit between beginning of mapping and beginning of
1084                  * PT_LOAD */
1085                 if (prot & PROT_WRITE && disp > 0) {
1086                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1087                         clear_user((void __user *) maddr, disp);
1088                         maddr += disp;
1089                 }
1090
1091                 /* clear any space allocated but not loaded
1092                  * - on uClinux we can just clear the lot
1093                  * - on MMU linux we'll get a SIGBUS beyond the last page
1094                  *   extant in the file
1095                  */
1096                 excess = phdr->p_memsz - phdr->p_filesz;
1097                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1098
1099 #ifdef CONFIG_MMU
1100                 if (excess > excess1) {
1101                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1102                         unsigned long xmaddr;
1103
1104                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1105                         down_write(&mm->mmap_sem);
1106                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1107                                          prot, flags, 0);
1108                         up_write(&mm->mmap_sem);
1109
1110                         kdebug("mmap[%d] <anon>"
1111                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1112                                loop, xaddr, excess - excess1, prot, flags,
1113                                xmaddr);
1114
1115                         if (xmaddr != xaddr)
1116                                 return -ENOMEM;
1117                 }
1118
1119                 if (prot & PROT_WRITE && excess1 > 0) {
1120                         kdebug("clear[%d] ad=%lx sz=%lx",
1121                                loop, maddr + phdr->p_filesz, excess1);
1122                         clear_user((void __user *) maddr + phdr->p_filesz,
1123                                    excess1);
1124                 }
1125
1126 #else
1127                 if (excess > 0) {
1128                         kdebug("clear[%d] ad=%lx sz=%lx",
1129                                loop, maddr + phdr->p_filesz, excess);
1130                         clear_user((void *) maddr + phdr->p_filesz, excess);
1131                 }
1132 #endif
1133
1134                 if (mm) {
1135                         if (phdr->p_flags & PF_X) {
1136                                 if (!mm->start_code) {
1137                                         mm->start_code = maddr;
1138                                         mm->end_code = maddr + phdr->p_memsz;
1139                                 }
1140                         } else if (!mm->start_data) {
1141                                 mm->start_data = maddr;
1142                                 mm->end_data = maddr + phdr->p_memsz;
1143                         }
1144                 }
1145
1146                 seg++;
1147         }
1148
1149         return 0;
1150 }
1151
1152 /*****************************************************************************/
1153 /*
1154  * ELF-FDPIC core dumper
1155  *
1156  * Modelled on fs/exec.c:aout_core_dump()
1157  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1158  *
1159  * Modelled on fs/binfmt_elf.c core dumper
1160  */
1161 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1162
1163 /*
1164  * These are the only things you should do on a core-file: use only these
1165  * functions to write out all the necessary info.
1166  */
1167 static int dump_write(struct file *file, const void *addr, int nr)
1168 {
1169         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1170 }
1171
1172 static int dump_seek(struct file *file, loff_t off)
1173 {
1174         if (file->f_op->llseek) {
1175                 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1176                         return 0;
1177         } else {
1178                 file->f_pos = off;
1179         }
1180         return 1;
1181 }
1182
1183 /*
1184  * Decide whether a segment is worth dumping; default is yes to be
1185  * sure (missing info is worse than too much; etc).
1186  * Personally I'd include everything, and use the coredump limit...
1187  *
1188  * I think we should skip something. But I am not sure how. H.J.
1189  */
1190 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1191 {
1192         int dump_ok;
1193
1194         /* Do not dump I/O mapped devices or special mappings */
1195         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1196                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1197                 return 0;
1198         }
1199
1200         /* If we may not read the contents, don't allow us to dump
1201          * them either. "dump_write()" can't handle it anyway.
1202          */
1203         if (!(vma->vm_flags & VM_READ)) {
1204                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1205                 return 0;
1206         }
1207
1208         /* By default, dump shared memory if mapped from an anonymous file. */
1209         if (vma->vm_flags & VM_SHARED) {
1210                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1211                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1212                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1213                                vma->vm_flags, dump_ok ? "yes" : "no");
1214                         return dump_ok;
1215                 }
1216
1217                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1218                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1219                        vma->vm_flags, dump_ok ? "yes" : "no");
1220                 return dump_ok;
1221         }
1222
1223 #ifdef CONFIG_MMU
1224         /* By default, if it hasn't been written to, don't write it out */
1225         if (!vma->anon_vma) {
1226                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1227                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1228                        vma->vm_flags, dump_ok ? "yes" : "no");
1229                 return dump_ok;
1230         }
1231 #endif
1232
1233         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1234         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1235                dump_ok ? "yes" : "no");
1236         return dump_ok;
1237 }
1238
1239 /* An ELF note in memory */
1240 struct memelfnote
1241 {
1242         const char *name;
1243         int type;
1244         unsigned int datasz;
1245         void *data;
1246 };
1247
1248 static int notesize(struct memelfnote *en)
1249 {
1250         int sz;
1251
1252         sz = sizeof(struct elf_note);
1253         sz += roundup(strlen(en->name) + 1, 4);
1254         sz += roundup(en->datasz, 4);
1255
1256         return sz;
1257 }
1258
1259 /* #define DEBUG */
1260
1261 #define DUMP_WRITE(addr, nr)    \
1262         do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1263 #define DUMP_SEEK(off)  \
1264         do { if (!dump_seek(file, (off))) return 0; } while(0)
1265
1266 static int writenote(struct memelfnote *men, struct file *file)
1267 {
1268         struct elf_note en;
1269
1270         en.n_namesz = strlen(men->name) + 1;
1271         en.n_descsz = men->datasz;
1272         en.n_type = men->type;
1273
1274         DUMP_WRITE(&en, sizeof(en));
1275         DUMP_WRITE(men->name, en.n_namesz);
1276         /* XXX - cast from long long to long to avoid need for libgcc.a */
1277         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1278         DUMP_WRITE(men->data, men->datasz);
1279         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1280
1281         return 1;
1282 }
1283 #undef DUMP_WRITE
1284 #undef DUMP_SEEK
1285
1286 #define DUMP_WRITE(addr, nr)    \
1287         if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1288                 goto end_coredump;
1289 #define DUMP_SEEK(off)  \
1290         if (!dump_seek(file, (off))) \
1291                 goto end_coredump;
1292
1293 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1294 {
1295         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1296         elf->e_ident[EI_CLASS] = ELF_CLASS;
1297         elf->e_ident[EI_DATA] = ELF_DATA;
1298         elf->e_ident[EI_VERSION] = EV_CURRENT;
1299         elf->e_ident[EI_OSABI] = ELF_OSABI;
1300         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1301
1302         elf->e_type = ET_CORE;
1303         elf->e_machine = ELF_ARCH;
1304         elf->e_version = EV_CURRENT;
1305         elf->e_entry = 0;
1306         elf->e_phoff = sizeof(struct elfhdr);
1307         elf->e_shoff = 0;
1308         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1309         elf->e_ehsize = sizeof(struct elfhdr);
1310         elf->e_phentsize = sizeof(struct elf_phdr);
1311         elf->e_phnum = segs;
1312         elf->e_shentsize = 0;
1313         elf->e_shnum = 0;
1314         elf->e_shstrndx = 0;
1315         return;
1316 }
1317
1318 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1319 {
1320         phdr->p_type = PT_NOTE;
1321         phdr->p_offset = offset;
1322         phdr->p_vaddr = 0;
1323         phdr->p_paddr = 0;
1324         phdr->p_filesz = sz;
1325         phdr->p_memsz = 0;
1326         phdr->p_flags = 0;
1327         phdr->p_align = 0;
1328         return;
1329 }
1330
1331 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1332                 unsigned int sz, void *data)
1333 {
1334         note->name = name;
1335         note->type = type;
1336         note->datasz = sz;
1337         note->data = data;
1338         return;
1339 }
1340
1341 /*
1342  * fill up all the fields in prstatus from the given task struct, except
1343  * registers which need to be filled up seperately.
1344  */
1345 static void fill_prstatus(struct elf_prstatus *prstatus,
1346                           struct task_struct *p, long signr)
1347 {
1348         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1349         prstatus->pr_sigpend = p->pending.signal.sig[0];
1350         prstatus->pr_sighold = p->blocked.sig[0];
1351         prstatus->pr_pid = task_pid_vnr(p);
1352         prstatus->pr_ppid = task_pid_vnr(p->parent);
1353         prstatus->pr_pgrp = task_pgrp_vnr(p);
1354         prstatus->pr_sid = task_session_vnr(p);
1355         if (thread_group_leader(p)) {
1356                 /*
1357                  * This is the record for the group leader.  Add in the
1358                  * cumulative times of previous dead threads.  This total
1359                  * won't include the time of each live thread whose state
1360                  * is included in the core dump.  The final total reported
1361                  * to our parent process when it calls wait4 will include
1362                  * those sums as well as the little bit more time it takes
1363                  * this and each other thread to finish dying after the
1364                  * core dump synchronization phase.
1365                  */
1366                 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1367                                    &prstatus->pr_utime);
1368                 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1369                                    &prstatus->pr_stime);
1370         } else {
1371                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1372                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1373         }
1374         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1375         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1376
1377         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1378         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1379 }
1380
1381 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1382                        struct mm_struct *mm)
1383 {
1384         unsigned int i, len;
1385
1386         /* first copy the parameters from user space */
1387         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1388
1389         len = mm->arg_end - mm->arg_start;
1390         if (len >= ELF_PRARGSZ)
1391                 len = ELF_PRARGSZ - 1;
1392         if (copy_from_user(&psinfo->pr_psargs,
1393                            (const char __user *) mm->arg_start, len))
1394                 return -EFAULT;
1395         for (i = 0; i < len; i++)
1396                 if (psinfo->pr_psargs[i] == 0)
1397                         psinfo->pr_psargs[i] = ' ';
1398         psinfo->pr_psargs[len] = 0;
1399
1400         psinfo->pr_pid = task_pid_vnr(p);
1401         psinfo->pr_ppid = task_pid_vnr(p->parent);
1402         psinfo->pr_pgrp = task_pgrp_vnr(p);
1403         psinfo->pr_sid = task_session_vnr(p);
1404
1405         i = p->state ? ffz(~p->state) + 1 : 0;
1406         psinfo->pr_state = i;
1407         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1408         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1409         psinfo->pr_nice = task_nice(p);
1410         psinfo->pr_flag = p->flags;
1411         SET_UID(psinfo->pr_uid, p->uid);
1412         SET_GID(psinfo->pr_gid, p->gid);
1413         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1414
1415         return 0;
1416 }
1417
1418 /* Here is the structure in which status of each thread is captured. */
1419 struct elf_thread_status
1420 {
1421         struct list_head list;
1422         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1423         elf_fpregset_t fpu;             /* NT_PRFPREG */
1424         struct task_struct *thread;
1425 #ifdef ELF_CORE_COPY_XFPREGS
1426         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1427 #endif
1428         struct memelfnote notes[3];
1429         int num_notes;
1430 };
1431
1432 /*
1433  * In order to add the specific thread information for the elf file format,
1434  * we need to keep a linked list of every thread's pr_status and then create
1435  * a single section for them in the final core file.
1436  */
1437 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1438 {
1439         struct task_struct *p = t->thread;
1440         int sz = 0;
1441
1442         t->num_notes = 0;
1443
1444         fill_prstatus(&t->prstatus, p, signr);
1445         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1446
1447         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1448                   &t->prstatus);
1449         t->num_notes++;
1450         sz += notesize(&t->notes[0]);
1451
1452         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1453         if (t->prstatus.pr_fpvalid) {
1454                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1455                           &t->fpu);
1456                 t->num_notes++;
1457                 sz += notesize(&t->notes[1]);
1458         }
1459
1460 #ifdef ELF_CORE_COPY_XFPREGS
1461         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1462                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1463                           sizeof(t->xfpu), &t->xfpu);
1464                 t->num_notes++;
1465                 sz += notesize(&t->notes[2]);
1466         }
1467 #endif
1468         return sz;
1469 }
1470
1471 /*
1472  * dump the segments for an MMU process
1473  */
1474 #ifdef CONFIG_MMU
1475 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1476                            unsigned long *limit, unsigned long mm_flags)
1477 {
1478         struct vm_area_struct *vma;
1479
1480         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1481                 unsigned long addr;
1482
1483                 if (!maydump(vma, mm_flags))
1484                         continue;
1485
1486                 for (addr = vma->vm_start;
1487                      addr < vma->vm_end;
1488                      addr += PAGE_SIZE
1489                      ) {
1490                         struct vm_area_struct *vma;
1491                         struct page *page;
1492
1493                         if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1494                                            &page, &vma) <= 0) {
1495                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1496                         }
1497                         else if (page == ZERO_PAGE(0)) {
1498                                 page_cache_release(page);
1499                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1500                         }
1501                         else {
1502                                 void *kaddr;
1503
1504                                 flush_cache_page(vma, addr, page_to_pfn(page));
1505                                 kaddr = kmap(page);
1506                                 if ((*size += PAGE_SIZE) > *limit ||
1507                                     !dump_write(file, kaddr, PAGE_SIZE)
1508                                     ) {
1509                                         kunmap(page);
1510                                         page_cache_release(page);
1511                                         return -EIO;
1512                                 }
1513                                 kunmap(page);
1514                                 page_cache_release(page);
1515                         }
1516                 }
1517         }
1518
1519         return 0;
1520
1521 end_coredump:
1522         return -EFBIG;
1523 }
1524 #endif
1525
1526 /*
1527  * dump the segments for a NOMMU process
1528  */
1529 #ifndef CONFIG_MMU
1530 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1531                            unsigned long *limit, unsigned long mm_flags)
1532 {
1533         struct vm_list_struct *vml;
1534
1535         for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1536         struct vm_area_struct *vma = vml->vma;
1537
1538                 if (!maydump(vma, mm_flags))
1539                         continue;
1540
1541                 if ((*size += PAGE_SIZE) > *limit)
1542                         return -EFBIG;
1543
1544                 if (!dump_write(file, (void *) vma->vm_start,
1545                                 vma->vm_end - vma->vm_start))
1546                         return -EIO;
1547         }
1548
1549         return 0;
1550 }
1551 #endif
1552
1553 /*
1554  * Actual dumper
1555  *
1556  * This is a two-pass process; first we find the offsets of the bits,
1557  * and then they are actually written out.  If we run out of core limit
1558  * we just truncate.
1559  */
1560 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1561                                struct file *file, unsigned long limit)
1562 {
1563 #define NUM_NOTES       6
1564         int has_dumped = 0;
1565         mm_segment_t fs;
1566         int segs;
1567         size_t size = 0;
1568         int i;
1569         struct vm_area_struct *vma;
1570         struct elfhdr *elf = NULL;
1571         loff_t offset = 0, dataoff;
1572         int numnote;
1573         struct memelfnote *notes = NULL;
1574         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1575         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1576         struct task_struct *g, *p;
1577         LIST_HEAD(thread_list);
1578         struct list_head *t;
1579         elf_fpregset_t *fpu = NULL;
1580 #ifdef ELF_CORE_COPY_XFPREGS
1581         elf_fpxregset_t *xfpu = NULL;
1582 #endif
1583         int thread_status_size = 0;
1584 #ifndef CONFIG_MMU
1585         struct vm_list_struct *vml;
1586 #endif
1587         elf_addr_t *auxv;
1588         unsigned long mm_flags;
1589
1590         /*
1591          * We no longer stop all VM operations.
1592          *
1593          * This is because those proceses that could possibly change map_count
1594          * or the mmap / vma pages are now blocked in do_exit on current
1595          * finishing this core dump.
1596          *
1597          * Only ptrace can touch these memory addresses, but it doesn't change
1598          * the map_count or the pages allocated. So no possibility of crashing
1599          * exists while dumping the mm->vm_next areas to the core file.
1600          */
1601
1602         /* alloc memory for large data structures: too large to be on stack */
1603         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1604         if (!elf)
1605                 goto cleanup;
1606         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1607         if (!prstatus)
1608                 goto cleanup;
1609         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1610         if (!psinfo)
1611                 goto cleanup;
1612         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1613         if (!notes)
1614                 goto cleanup;
1615         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1616         if (!fpu)
1617                 goto cleanup;
1618 #ifdef ELF_CORE_COPY_XFPREGS
1619         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1620         if (!xfpu)
1621                 goto cleanup;
1622 #endif
1623
1624         if (signr) {
1625                 struct elf_thread_status *tmp;
1626                 rcu_read_lock();
1627                 do_each_thread(g,p)
1628                         if (current->mm == p->mm && current != p) {
1629                                 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1630                                 if (!tmp) {
1631                                         rcu_read_unlock();
1632                                         goto cleanup;
1633                                 }
1634                                 tmp->thread = p;
1635                                 list_add(&tmp->list, &thread_list);
1636                         }
1637                 while_each_thread(g,p);
1638                 rcu_read_unlock();
1639                 list_for_each(t, &thread_list) {
1640                         struct elf_thread_status *tmp;
1641                         int sz;
1642
1643                         tmp = list_entry(t, struct elf_thread_status, list);
1644                         sz = elf_dump_thread_status(signr, tmp);
1645                         thread_status_size += sz;
1646                 }
1647         }
1648
1649         /* now collect the dump for the current */
1650         fill_prstatus(prstatus, current, signr);
1651         elf_core_copy_regs(&prstatus->pr_reg, regs);
1652
1653 #ifdef CONFIG_MMU
1654         segs = current->mm->map_count;
1655 #else
1656         segs = 0;
1657         for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1658             segs++;
1659 #endif
1660 #ifdef ELF_CORE_EXTRA_PHDRS
1661         segs += ELF_CORE_EXTRA_PHDRS;
1662 #endif
1663
1664         /* Set up header */
1665         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1666
1667         has_dumped = 1;
1668         current->flags |= PF_DUMPCORE;
1669
1670         /*
1671          * Set up the notes in similar form to SVR4 core dumps made
1672          * with info from their /proc.
1673          */
1674
1675         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1676         fill_psinfo(psinfo, current->group_leader, current->mm);
1677         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1678
1679         numnote = 2;
1680
1681         auxv = (elf_addr_t *) current->mm->saved_auxv;
1682
1683         i = 0;
1684         do
1685                 i += 2;
1686         while (auxv[i - 2] != AT_NULL);
1687         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1688                   i * sizeof(elf_addr_t), auxv);
1689
1690         /* Try to dump the FPU. */
1691         if ((prstatus->pr_fpvalid =
1692              elf_core_copy_task_fpregs(current, regs, fpu)))
1693                 fill_note(notes + numnote++,
1694                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1695 #ifdef ELF_CORE_COPY_XFPREGS
1696         if (elf_core_copy_task_xfpregs(current, xfpu))
1697                 fill_note(notes + numnote++,
1698                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1699 #endif
1700
1701         fs = get_fs();
1702         set_fs(KERNEL_DS);
1703
1704         DUMP_WRITE(elf, sizeof(*elf));
1705         offset += sizeof(*elf);                         /* Elf header */
1706         offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1707
1708         /* Write notes phdr entry */
1709         {
1710                 struct elf_phdr phdr;
1711                 int sz = 0;
1712
1713                 for (i = 0; i < numnote; i++)
1714                         sz += notesize(notes + i);
1715
1716                 sz += thread_status_size;
1717
1718                 fill_elf_note_phdr(&phdr, sz, offset);
1719                 offset += sz;
1720                 DUMP_WRITE(&phdr, sizeof(phdr));
1721         }
1722
1723         /* Page-align dumped data */
1724         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1725
1726         /*
1727          * We must use the same mm->flags while dumping core to avoid
1728          * inconsistency between the program headers and bodies, otherwise an
1729          * unusable core file can be generated.
1730          */
1731         mm_flags = current->mm->flags;
1732
1733         /* write program headers for segments dump */
1734         for (
1735 #ifdef CONFIG_MMU
1736                 vma = current->mm->mmap; vma; vma = vma->vm_next
1737 #else
1738                         vml = current->mm->context.vmlist; vml; vml = vml->next
1739 #endif
1740              ) {
1741                 struct elf_phdr phdr;
1742                 size_t sz;
1743
1744 #ifndef CONFIG_MMU
1745                 vma = vml->vma;
1746 #endif
1747
1748                 sz = vma->vm_end - vma->vm_start;
1749
1750                 phdr.p_type = PT_LOAD;
1751                 phdr.p_offset = offset;
1752                 phdr.p_vaddr = vma->vm_start;
1753                 phdr.p_paddr = 0;
1754                 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1755                 phdr.p_memsz = sz;
1756                 offset += phdr.p_filesz;
1757                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1758                 if (vma->vm_flags & VM_WRITE)
1759                         phdr.p_flags |= PF_W;
1760                 if (vma->vm_flags & VM_EXEC)
1761                         phdr.p_flags |= PF_X;
1762                 phdr.p_align = ELF_EXEC_PAGESIZE;
1763
1764                 DUMP_WRITE(&phdr, sizeof(phdr));
1765         }
1766
1767 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1768         ELF_CORE_WRITE_EXTRA_PHDRS;
1769 #endif
1770
1771         /* write out the notes section */
1772         for (i = 0; i < numnote; i++)
1773                 if (!writenote(notes + i, file))
1774                         goto end_coredump;
1775
1776         /* write out the thread status notes section */
1777         list_for_each(t, &thread_list) {
1778                 struct elf_thread_status *tmp =
1779                                 list_entry(t, struct elf_thread_status, list);
1780
1781                 for (i = 0; i < tmp->num_notes; i++)
1782                         if (!writenote(&tmp->notes[i], file))
1783                                 goto end_coredump;
1784         }
1785
1786         DUMP_SEEK(dataoff);
1787
1788         if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1789                 goto end_coredump;
1790
1791 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1792         ELF_CORE_WRITE_EXTRA_DATA;
1793 #endif
1794
1795         if (file->f_pos != offset) {
1796                 /* Sanity check */
1797                 printk(KERN_WARNING
1798                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1799                        file->f_pos, offset);
1800         }
1801
1802 end_coredump:
1803         set_fs(fs);
1804
1805 cleanup:
1806         while (!list_empty(&thread_list)) {
1807                 struct list_head *tmp = thread_list.next;
1808                 list_del(tmp);
1809                 kfree(list_entry(tmp, struct elf_thread_status, list));
1810         }
1811
1812         kfree(elf);
1813         kfree(prstatus);
1814         kfree(psinfo);
1815         kfree(notes);
1816         kfree(fpu);
1817 #ifdef ELF_CORE_COPY_XFPREGS
1818         kfree(xfpu);
1819 #endif
1820         return has_dumped;
1821 #undef NUM_NOTES
1822 }
1823
1824 #endif          /* USE_ELF_CORE_DUMP */