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         retval = 0;
 437
 438 error:
 439         if (interpreter) {
 440                 allow_write_access(interpreter);
 441                 fput(interpreter);
 442         }
 443         kfree(interpreter_name);
 444         kfree(exec_params.phdrs);
 445         kfree(exec_params.loadmap);
 446         kfree(interp_params.phdrs);
 447         kfree(interp_params.loadmap);
 448         return retval;
 449
 450         /* unrecoverable error - kill the process */
 451 error_kill:
 452         send_sig(SIGSEGV, current, 0);
 453         goto error;
 454
 455 }
 456
 457 /*****************************************************************************/
 458 /*
 459  * present useful information to the program
 460  */
 461 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 462                                    struct mm_struct *mm,
 463                                    struct elf_fdpic_params *exec_params,
 464                                    struct elf_fdpic_params *interp_params)
 465 {
 466         unsigned long sp, csp, nitems;
 467         elf_caddr_t __user *argv, *envp;
 468         size_t platform_len = 0, len;
 469         char *k_platform;
 470         char __user *u_platform, *p;
 471         long hwcap;
 472         int loop;
 473         int nr; /* reset for each csp adjustment */
 474
 475         /* we're going to shovel a whole load of stuff onto the stack */
 476 #ifdef CONFIG_MMU
 477         sp = bprm->p;
 478 #else
 479         sp = mm->start_stack;
 480
 481         /* stack the program arguments and environment */
 482         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 483                 return -EFAULT;
 484 #endif
 485
 486         /* get hold of platform and hardware capabilities masks for the machine
 487          * we are running on.  In some cases (Sparc), this info is impossible
 488          * to get, in others (i386) it is merely difficult.
 489          */
 490         hwcap = ELF_HWCAP;
 491         k_platform = ELF_PLATFORM;
 492         u_platform = NULL;
 493
 494         if (k_platform) {
 495                 platform_len = strlen(k_platform) + 1;
 496                 sp -= platform_len;
 497                 u_platform = (char __user *) sp;
 498                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 499                         return -EFAULT;
 500         }
 501
 502 #if defined(__i386__) && defined(CONFIG_SMP)
 503         /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 504          * by the processes running on the same package. One thing we can do is
 505          * to shuffle the initial stack for them.
 506          *
 507          * the conditionals here are unneeded, but kept in to make the code
 508          * behaviour the same as pre change unless we have hyperthreaded
 509          * processors. This keeps Mr Marcelo Person happier but should be
 510          * removed for 2.5
 511          */
 512         if (smp_num_siblings > 1)
 513                 sp = sp - ((current->pid % 64) << 7);
 514 #endif
 515
 516         sp &= ~7UL;
 517
 518         /* stack the load map(s) */
 519         len = sizeof(struct elf32_fdpic_loadmap);
 520         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 521         sp = (sp - len) & ~7UL;
 522         exec_params->map_addr = sp;
 523
 524         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 525                 return -EFAULT;
 526
 527         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 528
 529         if (interp_params->loadmap) {
 530                 len = sizeof(struct elf32_fdpic_loadmap);
 531                 len += sizeof(struct elf32_fdpic_loadseg) *
 532                         interp_params->loadmap->nsegs;
 533                 sp = (sp - len) & ~7UL;
 534                 interp_params->map_addr = sp;
 535
 536                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 537                                  len) != 0)
 538                         return -EFAULT;
 539
 540                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 541         }
 542
 543         /* force 16 byte _final_ alignment here for generality */
 544 #define DLINFO_ITEMS 13
 545
 546         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 547
 548         csp = sp;
 549         sp -= nitems * 2 * sizeof(unsigned long);
 550         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 551         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 552         sp -= 1 * sizeof(unsigned long);                /* argc */
 553
 554         csp -= sp & 15UL;
 555         sp -= sp & 15UL;
 556
 557         /* put the ELF interpreter info on the stack */
 558 #define NEW_AUX_ENT(id, val)                                            \
 559         do {                                                            \
 560                 struct { unsigned long _id, _val; } __user *ent;        \
 561                                                                         \
 562                 ent = (void __user *) csp;                              \
 563                 __put_user((id), &ent[nr]._id);                         \
 564                 __put_user((val), &ent[nr]._val);                       \
 565                 nr++;                                                   \
 566         } while (0)
 567
 568         nr = 0;
 569         csp -= 2 * sizeof(unsigned long);
 570         NEW_AUX_ENT(AT_NULL, 0);
 571         if (k_platform) {
 572                 nr = 0;
 573                 csp -= 2 * sizeof(unsigned long);
 574                 NEW_AUX_ENT(AT_PLATFORM,
 575                             (elf_addr_t) (unsigned long) u_platform);
 576         }
 577
 578         nr = 0;
 579         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 580         NEW_AUX_ENT(AT_HWCAP,   hwcap);
 581         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 582         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 583         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 584         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 585         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 586         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 587         NEW_AUX_ENT(AT_FLAGS,   0);
 588         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 589         NEW_AUX_ENT(AT_UID,     (elf_addr_t) current->uid);
 590         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) current->euid);
 591         NEW_AUX_ENT(AT_GID,     (elf_addr_t) current->gid);
 592         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) current->egid);
 593
 594 #ifdef ARCH_DLINFO
 595         nr = 0;
 596         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 597
 598         /* ARCH_DLINFO must come last so platform specific code can enforce
 599          * special alignment requirements on the AUXV if necessary (eg. PPC).
 600          */
 601         ARCH_DLINFO;
 602 #endif
 603 #undef NEW_AUX_ENT
 604
 605         /* allocate room for argv[] and envv[] */
 606         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 607         envp = (elf_caddr_t __user *) csp;
 608         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 609         argv = (elf_caddr_t __user *) csp;
 610
 611         /* stack argc */
 612         csp -= sizeof(unsigned long);
 613         __put_user(bprm->argc, (unsigned long __user *) csp);
 614
 615         BUG_ON(csp != sp);
 616
 617         /* fill in the argv[] array */
 618 #ifdef CONFIG_MMU
 619         current->mm->arg_start = bprm->p;
 620 #else
 621         current->mm->arg_start = current->mm->start_stack -
 622                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 623 #endif
 624
 625         p = (char __user *) current->mm->arg_start;
 626         for (loop = bprm->argc; loop > 0; loop--) {
 627                 __put_user((elf_caddr_t) p, argv++);
 628                 len = strnlen_user(p, MAX_ARG_STRLEN);
 629                 if (!len || len > MAX_ARG_STRLEN)
 630                         return -EINVAL;
 631                 p += len;
 632         }
 633         __put_user(NULL, argv);
 634         current->mm->arg_end = (unsigned long) p;
 635
 636         /* fill in the envv[] array */
 637         current->mm->env_start = (unsigned long) p;
 638         for (loop = bprm->envc; loop > 0; loop--) {
 639                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 640                 len = strnlen_user(p, MAX_ARG_STRLEN);
 641                 if (!len || len > MAX_ARG_STRLEN)
 642                         return -EINVAL;
 643                 p += len;
 644         }
 645         __put_user(NULL, envp);
 646         current->mm->env_end = (unsigned long) p;
 647
 648         mm->start_stack = (unsigned long) sp;
 649         return 0;
 650 }
 651
 652 /*****************************************************************************/
 653 /*
 654  * transfer the program arguments and environment from the holding pages onto
 655  * the stack
 656  */
 657 #ifndef CONFIG_MMU
 658 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 659                                             unsigned long *_sp)
 660 {
 661         unsigned long index, stop, sp;
 662         char *src;
 663         int ret = 0;
 664
 665         stop = bprm->p >> PAGE_SHIFT;
 666         sp = *_sp;
 667
 668         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 669                 src = kmap(bprm->page[index]);
 670                 sp -= PAGE_SIZE;
 671                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 672                         ret = -EFAULT;
 673                 kunmap(bprm->page[index]);
 674                 if (ret < 0)
 675                         goto out;
 676         }
 677
 678         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 679
 680 out:
 681         return ret;
 682 }
 683 #endif
 684
 685 /*****************************************************************************/
 686 /*
 687  * load the appropriate binary image (executable or interpreter) into memory
 688  * - we assume no MMU is available
 689  * - if no other PIC bits are set in params->hdr->e_flags
 690  *   - we assume that the LOADable segments in the binary are independently relocatable
 691  *   - we assume R/O executable segments are shareable
 692  * - else
 693  *   - we assume the loadable parts of the image to require fixed displacement
 694  *   - the image is not shareable
 695  */
 696 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 697                               struct file *file,
 698                               struct mm_struct *mm,
 699                               const char *what)
 700 {
 701         struct elf32_fdpic_loadmap *loadmap;
 702 #ifdef CONFIG_MMU
 703         struct elf32_fdpic_loadseg *mseg;
 704 #endif
 705         struct elf32_fdpic_loadseg *seg;
 706         struct elf32_phdr *phdr;
 707         unsigned long load_addr, stop;
 708         unsigned nloads, tmp;
 709         size_t size;
 710         int loop, ret;
 711
 712         /* allocate a load map table */
 713         nloads = 0;
 714         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 715                 if (params->phdrs[loop].p_type == PT_LOAD)
 716                         nloads++;
 717
 718         if (nloads == 0)
 719                 return -ELIBBAD;
 720
 721         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 722         loadmap = kzalloc(size, GFP_KERNEL);
 723         if (!loadmap)
 724                 return -ENOMEM;
 725
 726         params->loadmap = loadmap;
 727
 728         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 729         loadmap->nsegs = nloads;
 730
 731         load_addr = params->load_addr;
 732         seg = loadmap->segs;
 733
 734         /* map the requested LOADs into the memory space */
 735         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 736         case ELF_FDPIC_FLAG_CONSTDISP:
 737         case ELF_FDPIC_FLAG_CONTIGUOUS:
 738 #ifndef CONFIG_MMU
 739                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 740                 if (ret < 0)
 741                         return ret;
 742                 break;
 743 #endif
 744         default:
 745                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 746                 if (ret < 0)
 747                         return ret;
 748                 break;
 749         }
 750
 751         /* map the entry point */
 752         if (params->hdr.e_entry) {
 753                 seg = loadmap->segs;
 754                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 755                         if (params->hdr.e_entry >= seg->p_vaddr &&
 756                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 757                                 params->entry_addr =
 758                                         (params->hdr.e_entry - seg->p_vaddr) +
 759                                         seg->addr;
 760                                 break;
 761                         }
 762                 }
 763         }
 764
 765         /* determine where the program header table has wound up if mapped */
 766         stop = params->hdr.e_phoff;
 767         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 768         phdr = params->phdrs;
 769
 770         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 771                 if (phdr->p_type != PT_LOAD)
 772                         continue;
 773
 774                 if (phdr->p_offset > params->hdr.e_phoff ||
 775                     phdr->p_offset + phdr->p_filesz < stop)
 776                         continue;
 777
 778                 seg = loadmap->segs;
 779                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 780                         if (phdr->p_vaddr >= seg->p_vaddr &&
 781                             phdr->p_vaddr + phdr->p_filesz <=
 782                             seg->p_vaddr + seg->p_memsz) {
 783                                 params->ph_addr =
 784                                         (phdr->p_vaddr - seg->p_vaddr) +
 785                                         seg->addr +
 786                                         params->hdr.e_phoff - phdr->p_offset;
 787                                 break;
 788                         }
 789                 }
 790                 break;
 791         }
 792
 793         /* determine where the dynamic section has wound up if there is one */
 794         phdr = params->phdrs;
 795         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 796                 if (phdr->p_type != PT_DYNAMIC)
 797                         continue;
 798
 799                 seg = loadmap->segs;
 800                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 801                         if (phdr->p_vaddr >= seg->p_vaddr &&
 802                             phdr->p_vaddr + phdr->p_memsz <=
 803                             seg->p_vaddr + seg->p_memsz) {
 804                                 params->dynamic_addr =
 805                                         (phdr->p_vaddr - seg->p_vaddr) +
 806                                         seg->addr;
 807
 808                                 /* check the dynamic section contains at least
 809                                  * one item, and that the last item is a NULL
 810                                  * entry */
 811                                 if (phdr->p_memsz == 0 ||
 812                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 813                                         goto dynamic_error;
 814
 815                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 816                                 if (((Elf32_Dyn *)
 817                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
 818                                         goto dynamic_error;
 819                                 break;
 820                         }
 821                 }
 822                 break;
 823         }
 824
 825         /* now elide adjacent segments in the load map on MMU linux
 826          * - on uClinux the holes between may actually be filled with system
 827          *   stuff or stuff from other processes
 828          */
 829 #ifdef CONFIG_MMU
 830         nloads = loadmap->nsegs;
 831         mseg = loadmap->segs;
 832         seg = mseg + 1;
 833         for (loop = 1; loop < nloads; loop++) {
 834                 /* see if we have a candidate for merging */
 835                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 836                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 837                         if (load_addr == (seg->addr & PAGE_MASK)) {
 838                                 mseg->p_memsz +=
 839                                         load_addr -
 840                                         (mseg->addr + mseg->p_memsz);
 841                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 842                                 mseg->p_memsz += seg->p_memsz;
 843                                 loadmap->nsegs--;
 844                                 continue;
 845                         }
 846                 }
 847
 848                 mseg++;
 849                 if (mseg != seg)
 850                         *mseg = *seg;
 851         }
 852 #endif
 853
 854         kdebug("Mapped Object [%s]:", what);
 855         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 856         kdebug("- entry    : %lx", params->entry_addr);
 857         kdebug("- PHDR[]   : %lx", params->ph_addr);
 858         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 859         seg = loadmap->segs;
 860         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 861                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 862                        loop,
 863                        seg->addr, seg->addr + seg->p_memsz - 1,
 864                        seg->p_vaddr, seg->p_memsz);
 865
 866         return 0;
 867
 868 dynamic_error:
 869         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 870                what, file->f_path.dentry->d_inode->i_ino);
 871         return -ELIBBAD;
 872 }
 873
 874 /*****************************************************************************/
 875 /*
 876  * map a file with constant displacement under uClinux
 877  */
 878 #ifndef CONFIG_MMU
 879 static int elf_fdpic_map_file_constdisp_on_uclinux(
 880         struct elf_fdpic_params *params,
 881         struct file *file,
 882         struct mm_struct *mm)
 883 {
 884         struct elf32_fdpic_loadseg *seg;
 885         struct elf32_phdr *phdr;
 886         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 887         loff_t fpos;
 888         int loop, ret;
 889
 890         load_addr = params->load_addr;
 891         seg = params->loadmap->segs;
 892
 893         /* determine the bounds of the contiguous overall allocation we must
 894          * make */
 895         phdr = params->phdrs;
 896         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 897                 if (params->phdrs[loop].p_type != PT_LOAD)
 898                         continue;
 899
 900                 if (base > phdr->p_vaddr)
 901                         base = phdr->p_vaddr;
 902                 if (top < phdr->p_vaddr + phdr->p_memsz)
 903                         top = phdr->p_vaddr + phdr->p_memsz;
 904         }
 905
 906         /* allocate one big anon block for everything */
 907         mflags = MAP_PRIVATE;
 908         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 909                 mflags |= MAP_EXECUTABLE;
 910
 911         down_write(&mm->mmap_sem);
 912         maddr = do_mmap(NULL, load_addr, top - base,
 913                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 914         up_write(&mm->mmap_sem);
 915         if (IS_ERR_VALUE(maddr))
 916                 return (int) maddr;
 917
 918         if (load_addr != 0)
 919                 load_addr += PAGE_ALIGN(top - base);
 920
 921         /* and then load the file segments into it */
 922         phdr = params->phdrs;
 923         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 924                 if (params->phdrs[loop].p_type != PT_LOAD)
 925                         continue;
 926
 927                 fpos = phdr->p_offset;
 928
 929                 seg->addr = maddr + (phdr->p_vaddr - base);
 930                 seg->p_vaddr = phdr->p_vaddr;
 931                 seg->p_memsz = phdr->p_memsz;
 932
 933                 ret = file->f_op->read(file, (void *) seg->addr,
 934                                        phdr->p_filesz, &fpos);
 935                 if (ret < 0)
 936                         return ret;
 937
 938                 /* map the ELF header address if in this segment */
 939                 if (phdr->p_offset == 0)
 940                         params->elfhdr_addr = seg->addr;
 941
 942                 /* clear any space allocated but not loaded */
 943                 if (phdr->p_filesz < phdr->p_memsz)
 944                         clear_user((void *) (seg->addr + phdr->p_filesz),
 945                                    phdr->p_memsz - phdr->p_filesz);
 946
 947                 if (mm) {
 948                         if (phdr->p_flags & PF_X) {
 949                                 if (!mm->start_code) {
 950                                         mm->start_code = seg->addr;
 951                                         mm->end_code = seg->addr +
 952                                                 phdr->p_memsz;
 953                                 }
 954                         } else if (!mm->start_data) {
 955                                 mm->start_data = seg->addr;
 956 #ifndef CONFIG_MMU
 957                                 mm->end_data = seg->addr + phdr->p_memsz;
 958 #endif
 959                         }
 960
 961 #ifdef CONFIG_MMU
 962                         if (seg->addr + phdr->p_memsz > mm->end_data)
 963                                 mm->end_data = seg->addr + phdr->p_memsz;
 964 #endif
 965                 }
 966
 967                 seg++;
 968         }
 969
 970         return 0;
 971 }
 972 #endif
 973
 974 /*****************************************************************************/
 975 /*
 976  * map a binary by direct mmap() of the individual PT_LOAD segments
 977  */
 978 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
 979                                              struct file *file,
 980                                              struct mm_struct *mm)
 981 {
 982         struct elf32_fdpic_loadseg *seg;
 983         struct elf32_phdr *phdr;
 984         unsigned long load_addr, delta_vaddr;
 985         int loop, dvset;
 986
 987         load_addr = params->load_addr;
 988         delta_vaddr = 0;
 989         dvset = 0;
 990
 991         seg = params->loadmap->segs;
 992
 993         /* deal with each load segment separately */
 994         phdr = params->phdrs;
 995         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 996                 unsigned long maddr, disp, excess, excess1;
 997                 int prot = 0, flags;
 998
 999                 if (phdr->p_type != PT_LOAD)
1000                         continue;
1001
1002                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1003                        (unsigned long) phdr->p_vaddr,
1004                        (unsigned long) phdr->p_offset,
1005                        (unsigned long) phdr->p_filesz,
1006                        (unsigned long) phdr->p_memsz);
1007
1008                 /* determine the mapping parameters */
1009                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1010                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1011                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1012
1013                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1014                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1015                         flags |= MAP_EXECUTABLE;
1016
1017                 maddr = 0;
1018
1019                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1020                 case ELF_FDPIC_FLAG_INDEPENDENT:
1021                         /* PT_LOADs are independently locatable */
1022                         break;
1023
1024                 case ELF_FDPIC_FLAG_HONOURVADDR:
1025                         /* the specified virtual address must be honoured */
1026                         maddr = phdr->p_vaddr;
1027                         flags |= MAP_FIXED;
1028                         break;
1029
1030                 case ELF_FDPIC_FLAG_CONSTDISP:
1031                         /* constant displacement
1032                          * - can be mapped anywhere, but must be mapped as a
1033                          *   unit
1034                          */
1035                         if (!dvset) {
1036                                 maddr = load_addr;
1037                                 delta_vaddr = phdr->p_vaddr;
1038                                 dvset = 1;
1039                         } else {
1040                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1041                                 flags |= MAP_FIXED;
1042                         }
1043                         break;
1044
1045                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1046                         /* contiguity handled later */
1047                         break;
1048
1049                 default:
1050                         BUG();
1051                 }
1052
1053                 maddr &= PAGE_MASK;
1054
1055                 /* create the mapping */
1056                 disp = phdr->p_vaddr & ~PAGE_MASK;
1057                 down_write(&mm->mmap_sem);
1058                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1059                                 phdr->p_offset - disp);
1060                 up_write(&mm->mmap_sem);
1061
1062                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1063                        loop, phdr->p_memsz + disp, prot, flags,
1064                        phdr->p_offset - disp, maddr);
1065
1066                 if (IS_ERR_VALUE(maddr))
1067                         return (int) maddr;
1068
1069                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1070                     ELF_FDPIC_FLAG_CONTIGUOUS)
1071                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1072
1073                 seg->addr = maddr + disp;
1074                 seg->p_vaddr = phdr->p_vaddr;
1075                 seg->p_memsz = phdr->p_memsz;
1076
1077                 /* map the ELF header address if in this segment */
1078                 if (phdr->p_offset == 0)
1079                         params->elfhdr_addr = seg->addr;
1080
1081                 /* clear the bit between beginning of mapping and beginning of
1082                  * PT_LOAD */
1083                 if (prot & PROT_WRITE && disp > 0) {
1084                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1085                         clear_user((void __user *) maddr, disp);
1086                         maddr += disp;
1087                 }
1088
1089                 /* clear any space allocated but not loaded
1090                  * - on uClinux we can just clear the lot
1091                  * - on MMU linux we'll get a SIGBUS beyond the last page
1092                  *   extant in the file
1093                  */
1094                 excess = phdr->p_memsz - phdr->p_filesz;
1095                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1096
1097 #ifdef CONFIG_MMU
1098                 if (excess > excess1) {
1099                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1100                         unsigned long xmaddr;
1101
1102                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1103                         down_write(&mm->mmap_sem);
1104                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1105                                          prot, flags, 0);
1106                         up_write(&mm->mmap_sem);
1107
1108                         kdebug("mmap[%d] <anon>"
1109                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1110                                loop, xaddr, excess - excess1, prot, flags,
1111                                xmaddr);
1112
1113                         if (xmaddr != xaddr)
1114                                 return -ENOMEM;
1115                 }
1116
1117                 if (prot & PROT_WRITE && excess1 > 0) {
1118                         kdebug("clear[%d] ad=%lx sz=%lx",
1119                                loop, maddr + phdr->p_filesz, excess1);
1120                         clear_user((void __user *) maddr + phdr->p_filesz,
1121                                    excess1);
1122                 }
1123
1124 #else
1125                 if (excess > 0) {
1126                         kdebug("clear[%d] ad=%lx sz=%lx",
1127                                loop, maddr + phdr->p_filesz, excess);
1128                         clear_user((void *) maddr + phdr->p_filesz, excess);
1129                 }
1130 #endif
1131
1132                 if (mm) {
1133                         if (phdr->p_flags & PF_X) {
1134                                 if (!mm->start_code) {
1135                                         mm->start_code = maddr;
1136                                         mm->end_code = maddr + phdr->p_memsz;
1137                                 }
1138                         } else if (!mm->start_data) {
1139                                 mm->start_data = maddr;
1140                                 mm->end_data = maddr + phdr->p_memsz;
1141                         }
1142                 }
1143
1144                 seg++;
1145         }
1146
1147         return 0;
1148 }
1149
1150 /*****************************************************************************/
1151 /*
1152  * ELF-FDPIC core dumper
1153  *
1154  * Modelled on fs/exec.c:aout_core_dump()
1155  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1156  *
1157  * Modelled on fs/binfmt_elf.c core dumper
1158  */
1159 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1160
1161 /*
1162  * These are the only things you should do on a core-file: use only these
1163  * functions to write out all the necessary info.
1164  */
1165 static int dump_write(struct file *file, const void *addr, int nr)
1166 {
1167         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1168 }
1169
1170 static int dump_seek(struct file *file, loff_t off)
1171 {
1172         if (file->f_op->llseek) {
1173                 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1174                         return 0;
1175         } else {
1176                 file->f_pos = off;
1177         }
1178         return 1;
1179 }
1180
1181 /*
1182  * Decide whether a segment is worth dumping; default is yes to be
1183  * sure (missing info is worse than too much; etc).
1184  * Personally I'd include everything, and use the coredump limit...
1185  *
1186  * I think we should skip something. But I am not sure how. H.J.
1187  */
1188 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1189 {
1190         int dump_ok;
1191
1192         /* Do not dump I/O mapped devices or special mappings */
1193         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1194                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1195                 return 0;
1196         }
1197
1198         /* If we may not read the contents, don't allow us to dump
1199          * them either. "dump_write()" can't handle it anyway.
1200          */
1201         if (!(vma->vm_flags & VM_READ)) {
1202                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1203                 return 0;
1204         }
1205
1206         /* By default, dump shared memory if mapped from an anonymous file. */
1207         if (vma->vm_flags & VM_SHARED) {
1208                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1209                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1210                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1211                                vma->vm_flags, dump_ok ? "yes" : "no");
1212                         return dump_ok;
1213                 }
1214
1215                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1216                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1217                        vma->vm_flags, dump_ok ? "yes" : "no");
1218                 return dump_ok;
1219         }
1220
1221 #ifdef CONFIG_MMU
1222         /* By default, if it hasn't been written to, don't write it out */
1223         if (!vma->anon_vma) {
1224                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1225                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1226                        vma->vm_flags, dump_ok ? "yes" : "no");
1227                 return dump_ok;
1228         }
1229 #endif
1230
1231         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1232         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1233                dump_ok ? "yes" : "no");
1234         return dump_ok;
1235 }
1236
1237 /* An ELF note in memory */
1238 struct memelfnote
1239 {
1240         const char *name;
1241         int type;
1242         unsigned int datasz;
1243         void *data;
1244 };
1245
1246 static int notesize(struct memelfnote *en)
1247 {
1248         int sz;
1249
1250         sz = sizeof(struct elf_note);
1251         sz += roundup(strlen(en->name) + 1, 4);
1252         sz += roundup(en->datasz, 4);
1253
1254         return sz;
1255 }
1256
1257 /* #define DEBUG */
1258
1259 #define DUMP_WRITE(addr, nr)    \
1260         do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1261 #define DUMP_SEEK(off)  \
1262         do { if (!dump_seek(file, (off))) return 0; } while(0)
1263
1264 static int writenote(struct memelfnote *men, struct file *file)
1265 {
1266         struct elf_note en;
1267
1268         en.n_namesz = strlen(men->name) + 1;
1269         en.n_descsz = men->datasz;
1270         en.n_type = men->type;
1271
1272         DUMP_WRITE(&en, sizeof(en));
1273         DUMP_WRITE(men->name, en.n_namesz);
1274         /* XXX - cast from long long to long to avoid need for libgcc.a */
1275         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1276         DUMP_WRITE(men->data, men->datasz);
1277         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1278
1279         return 1;
1280 }
1281 #undef DUMP_WRITE
1282 #undef DUMP_SEEK
1283
1284 #define DUMP_WRITE(addr, nr)    \
1285         if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1286                 goto end_coredump;
1287 #define DUMP_SEEK(off)  \
1288         if (!dump_seek(file, (off))) \
1289                 goto end_coredump;
1290
1291 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1292 {
1293         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1294         elf->e_ident[EI_CLASS] = ELF_CLASS;
1295         elf->e_ident[EI_DATA] = ELF_DATA;
1296         elf->e_ident[EI_VERSION] = EV_CURRENT;
1297         elf->e_ident[EI_OSABI] = ELF_OSABI;
1298         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1299
1300         elf->e_type = ET_CORE;
1301         elf->e_machine = ELF_ARCH;
1302         elf->e_version = EV_CURRENT;
1303         elf->e_entry = 0;
1304         elf->e_phoff = sizeof(struct elfhdr);
1305         elf->e_shoff = 0;
1306         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1307         elf->e_ehsize = sizeof(struct elfhdr);
1308         elf->e_phentsize = sizeof(struct elf_phdr);
1309         elf->e_phnum = segs;
1310         elf->e_shentsize = 0;
1311         elf->e_shnum = 0;
1312         elf->e_shstrndx = 0;
1313         return;
1314 }
1315
1316 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1317 {
1318         phdr->p_type = PT_NOTE;
1319         phdr->p_offset = offset;
1320         phdr->p_vaddr = 0;
1321         phdr->p_paddr = 0;
1322         phdr->p_filesz = sz;
1323         phdr->p_memsz = 0;
1324         phdr->p_flags = 0;
1325         phdr->p_align = 0;
1326         return;
1327 }
1328
1329 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1330                 unsigned int sz, void *data)
1331 {
1332         note->name = name;
1333         note->type = type;
1334         note->datasz = sz;
1335         note->data = data;
1336         return;
1337 }
1338
1339 /*
1340  * fill up all the fields in prstatus from the given task struct, except
1341  * registers which need to be filled up seperately.
1342  */
1343 static void fill_prstatus(struct elf_prstatus *prstatus,
1344                           struct task_struct *p, long signr)
1345 {
1346         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1347         prstatus->pr_sigpend = p->pending.signal.sig[0];
1348         prstatus->pr_sighold = p->blocked.sig[0];
1349         prstatus->pr_pid = task_pid_vnr(p);
1350         prstatus->pr_ppid = task_pid_vnr(p->parent);
1351         prstatus->pr_pgrp = task_pgrp_vnr(p);
1352         prstatus->pr_sid = task_session_vnr(p);
1353         if (thread_group_leader(p)) {
1354                 /*
1355                  * This is the record for the group leader.  Add in the
1356                  * cumulative times of previous dead threads.  This total
1357                  * won't include the time of each live thread whose state
1358                  * is included in the core dump.  The final total reported
1359                  * to our parent process when it calls wait4 will include
1360                  * those sums as well as the little bit more time it takes
1361                  * this and each other thread to finish dying after the
1362                  * core dump synchronization phase.
1363                  */
1364                 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1365                                    &prstatus->pr_utime);
1366                 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1367                                    &prstatus->pr_stime);
1368         } else {
1369                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1370                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1371         }
1372         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1373         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1374
1375         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1376         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1377 }
1378
1379 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1380                        struct mm_struct *mm)
1381 {
1382         unsigned int i, len;
1383
1384         /* first copy the parameters from user space */
1385         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1386
1387         len = mm->arg_end - mm->arg_start;
1388         if (len >= ELF_PRARGSZ)
1389                 len = ELF_PRARGSZ - 1;
1390         if (copy_from_user(&psinfo->pr_psargs,
1391                            (const char __user *) mm->arg_start, len))
1392                 return -EFAULT;
1393         for (i = 0; i < len; i++)
1394                 if (psinfo->pr_psargs[i] == 0)
1395                         psinfo->pr_psargs[i] = ' ';
1396         psinfo->pr_psargs[len] = 0;
1397
1398         psinfo->pr_pid = task_pid_vnr(p);
1399         psinfo->pr_ppid = task_pid_vnr(p->parent);
1400         psinfo->pr_pgrp = task_pgrp_vnr(p);
1401         psinfo->pr_sid = task_session_vnr(p);
1402
1403         i = p->state ? ffz(~p->state) + 1 : 0;
1404         psinfo->pr_state = i;
1405         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1406         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1407         psinfo->pr_nice = task_nice(p);
1408         psinfo->pr_flag = p->flags;
1409         SET_UID(psinfo->pr_uid, p->uid);
1410         SET_GID(psinfo->pr_gid, p->gid);
1411         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1412
1413         return 0;
1414 }
1415
1416 /* Here is the structure in which status of each thread is captured. */
1417 struct elf_thread_status
1418 {
1419         struct list_head list;
1420         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1421         elf_fpregset_t fpu;             /* NT_PRFPREG */
1422         struct task_struct *thread;
1423 #ifdef ELF_CORE_COPY_XFPREGS
1424         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1425 #endif
1426         struct memelfnote notes[3];
1427         int num_notes;
1428 };
1429
1430 /*
1431  * In order to add the specific thread information for the elf file format,
1432  * we need to keep a linked list of every thread's pr_status and then create
1433  * a single section for them in the final core file.
1434  */
1435 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1436 {
1437         struct task_struct *p = t->thread;
1438         int sz = 0;
1439
1440         t->num_notes = 0;
1441
1442         fill_prstatus(&t->prstatus, p, signr);
1443         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1444
1445         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1446                   &t->prstatus);
1447         t->num_notes++;
1448         sz += notesize(&t->notes[0]);
1449
1450         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1451         if (t->prstatus.pr_fpvalid) {
1452                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1453                           &t->fpu);
1454                 t->num_notes++;
1455                 sz += notesize(&t->notes[1]);
1456         }
1457
1458 #ifdef ELF_CORE_COPY_XFPREGS
1459         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1460                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1461                           sizeof(t->xfpu), &t->xfpu);
1462                 t->num_notes++;
1463                 sz += notesize(&t->notes[2]);
1464         }
1465 #endif
1466         return sz;
1467 }
1468
1469 /*
1470  * dump the segments for an MMU process
1471  */
1472 #ifdef CONFIG_MMU
1473 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1474                            unsigned long *limit, unsigned long mm_flags)
1475 {
1476         struct vm_area_struct *vma;
1477
1478         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1479                 unsigned long addr;
1480
1481                 if (!maydump(vma, mm_flags))
1482                         continue;
1483
1484                 for (addr = vma->vm_start;
1485                      addr < vma->vm_end;
1486                      addr += PAGE_SIZE
1487                      ) {
1488                         struct vm_area_struct *vma;
1489                         struct page *page;
1490
1491                         if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1492                                            &page, &vma) <= 0) {
1493                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1494                         }
1495                         else if (page == ZERO_PAGE(0)) {
1496                                 page_cache_release(page);
1497                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1498                         }
1499                         else {
1500                                 void *kaddr;
1501
1502                                 flush_cache_page(vma, addr, page_to_pfn(page));
1503                                 kaddr = kmap(page);
1504                                 if ((*size += PAGE_SIZE) > *limit ||
1505                                     !dump_write(file, kaddr, PAGE_SIZE)
1506                                     ) {
1507                                         kunmap(page);
1508                                         page_cache_release(page);
1509                                         return -EIO;
1510                                 }
1511                                 kunmap(page);
1512                                 page_cache_release(page);
1513                         }
1514                 }
1515         }
1516
1517         return 0;
1518
1519 end_coredump:
1520         return -EFBIG;
1521 }
1522 #endif
1523
1524 /*
1525  * dump the segments for a NOMMU process
1526  */
1527 #ifndef CONFIG_MMU
1528 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1529                            unsigned long *limit, unsigned long mm_flags)
1530 {
1531         struct vm_list_struct *vml;
1532
1533         for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1534         struct vm_area_struct *vma = vml->vma;
1535
1536                 if (!maydump(vma, mm_flags))
1537                         continue;
1538
1539                 if ((*size += PAGE_SIZE) > *limit)
1540                         return -EFBIG;
1541
1542                 if (!dump_write(file, (void *) vma->vm_start,
1543                                 vma->vm_end - vma->vm_start))
1544                         return -EIO;
1545         }
1546
1547         return 0;
1548 }
1549 #endif
1550
1551 /*
1552  * Actual dumper
1553  *
1554  * This is a two-pass process; first we find the offsets of the bits,
1555  * and then they are actually written out.  If we run out of core limit
1556  * we just truncate.
1557  */
1558 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1559                                struct file *file, unsigned long limit)
1560 {
1561 #define NUM_NOTES       6
1562         int has_dumped = 0;
1563         mm_segment_t fs;
1564         int segs;
1565         size_t size = 0;
1566         int i;
1567         struct vm_area_struct *vma;
1568         struct elfhdr *elf = NULL;
1569         loff_t offset = 0, dataoff;
1570         int numnote;
1571         struct memelfnote *notes = NULL;
1572         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1573         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1574         LIST_HEAD(thread_list);
1575         struct list_head *t;
1576         elf_fpregset_t *fpu = NULL;
1577 #ifdef ELF_CORE_COPY_XFPREGS
1578         elf_fpxregset_t *xfpu = NULL;
1579 #endif
1580         int thread_status_size = 0;
1581 #ifndef CONFIG_MMU
1582         struct vm_list_struct *vml;
1583 #endif
1584         elf_addr_t *auxv;
1585         unsigned long mm_flags;
1586
1587         /*
1588          * We no longer stop all VM operations.
1589          *
1590          * This is because those proceses that could possibly change map_count
1591          * or the mmap / vma pages are now blocked in do_exit on current
1592          * finishing this core dump.
1593          *
1594          * Only ptrace can touch these memory addresses, but it doesn't change
1595          * the map_count or the pages allocated. So no possibility of crashing
1596          * exists while dumping the mm->vm_next areas to the core file.
1597          */
1598
1599         /* alloc memory for large data structures: too large to be on stack */
1600         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1601         if (!elf)
1602                 goto cleanup;
1603         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1604         if (!prstatus)
1605                 goto cleanup;
1606         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1607         if (!psinfo)
1608                 goto cleanup;
1609         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1610         if (!notes)
1611                 goto cleanup;
1612         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1613         if (!fpu)
1614                 goto cleanup;
1615 #ifdef ELF_CORE_COPY_XFPREGS
1616         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1617         if (!xfpu)
1618                 goto cleanup;
1619 #endif
1620
1621         if (signr) {
1622                 struct core_thread *ct;
1623                 struct elf_thread_status *tmp;
1624
1625                 for (ct = current->mm->core_state->dumper.next;
1626                                                 ct; ct = ct->next) {
1627                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1628                         if (!tmp)
1629                                 goto cleanup;
1630
1631                         tmp->thread = ct->task;
1632                         list_add(&tmp->list, &thread_list);
1633                 }
1634
1635                 list_for_each(t, &thread_list) {
1636                         struct elf_thread_status *tmp;
1637                         int sz;
1638
1639                         tmp = list_entry(t, struct elf_thread_status, list);
1640                         sz = elf_dump_thread_status(signr, tmp);
1641                         thread_status_size += sz;
1642                 }
1643         }
1644
1645         /* now collect the dump for the current */
1646         fill_prstatus(prstatus, current, signr);
1647         elf_core_copy_regs(&prstatus->pr_reg, regs);
1648
1649 #ifdef CONFIG_MMU
1650         segs = current->mm->map_count;
1651 #else
1652         segs = 0;
1653         for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1654             segs++;
1655 #endif
1656 #ifdef ELF_CORE_EXTRA_PHDRS
1657         segs += ELF_CORE_EXTRA_PHDRS;
1658 #endif
1659
1660         /* Set up header */
1661         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1662
1663         has_dumped = 1;
1664         current->flags |= PF_DUMPCORE;
1665
1666         /*
1667          * Set up the notes in similar form to SVR4 core dumps made
1668          * with info from their /proc.
1669          */
1670
1671         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1672         fill_psinfo(psinfo, current->group_leader, current->mm);
1673         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1674
1675         numnote = 2;
1676
1677         auxv = (elf_addr_t *) current->mm->saved_auxv;
1678
1679         i = 0;
1680         do
1681                 i += 2;
1682         while (auxv[i - 2] != AT_NULL);
1683         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1684                   i * sizeof(elf_addr_t), auxv);
1685
1686         /* Try to dump the FPU. */
1687         if ((prstatus->pr_fpvalid =
1688              elf_core_copy_task_fpregs(current, regs, fpu)))
1689                 fill_note(notes + numnote++,
1690                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1691 #ifdef ELF_CORE_COPY_XFPREGS
1692         if (elf_core_copy_task_xfpregs(current, xfpu))
1693                 fill_note(notes + numnote++,
1694                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1695 #endif
1696
1697         fs = get_fs();
1698         set_fs(KERNEL_DS);
1699
1700         DUMP_WRITE(elf, sizeof(*elf));
1701         offset += sizeof(*elf);                         /* Elf header */
1702         offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1703
1704         /* Write notes phdr entry */
1705         {
1706                 struct elf_phdr phdr;
1707                 int sz = 0;
1708
1709                 for (i = 0; i < numnote; i++)
1710                         sz += notesize(notes + i);
1711
1712                 sz += thread_status_size;
1713
1714                 fill_elf_note_phdr(&phdr, sz, offset);
1715                 offset += sz;
1716                 DUMP_WRITE(&phdr, sizeof(phdr));
1717         }
1718
1719         /* Page-align dumped data */
1720         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1721
1722         /*
1723          * We must use the same mm->flags while dumping core to avoid
1724          * inconsistency between the program headers and bodies, otherwise an
1725          * unusable core file can be generated.
1726          */
1727         mm_flags = current->mm->flags;
1728
1729         /* write program headers for segments dump */
1730         for (
1731 #ifdef CONFIG_MMU
1732                 vma = current->mm->mmap; vma; vma = vma->vm_next
1733 #else
1734                         vml = current->mm->context.vmlist; vml; vml = vml->next
1735 #endif
1736              ) {
1737                 struct elf_phdr phdr;
1738                 size_t sz;
1739
1740 #ifndef CONFIG_MMU
1741                 vma = vml->vma;
1742 #endif
1743
1744                 sz = vma->vm_end - vma->vm_start;
1745
1746                 phdr.p_type = PT_LOAD;
1747                 phdr.p_offset = offset;
1748                 phdr.p_vaddr = vma->vm_start;
1749                 phdr.p_paddr = 0;
1750                 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1751                 phdr.p_memsz = sz;
1752                 offset += phdr.p_filesz;
1753                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1754                 if (vma->vm_flags & VM_WRITE)
1755                         phdr.p_flags |= PF_W;
1756                 if (vma->vm_flags & VM_EXEC)
1757                         phdr.p_flags |= PF_X;
1758                 phdr.p_align = ELF_EXEC_PAGESIZE;
1759
1760                 DUMP_WRITE(&phdr, sizeof(phdr));
1761         }
1762
1763 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1764         ELF_CORE_WRITE_EXTRA_PHDRS;
1765 #endif
1766
1767         /* write out the notes section */
1768         for (i = 0; i < numnote; i++)
1769                 if (!writenote(notes + i, file))
1770                         goto end_coredump;
1771
1772         /* write out the thread status notes section */
1773         list_for_each(t, &thread_list) {
1774                 struct elf_thread_status *tmp =
1775                                 list_entry(t, struct elf_thread_status, list);
1776
1777                 for (i = 0; i < tmp->num_notes; i++)
1778                         if (!writenote(&tmp->notes[i], file))
1779                                 goto end_coredump;
1780         }
1781
1782         DUMP_SEEK(dataoff);
1783
1784         if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1785                 goto end_coredump;
1786
1787 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1788         ELF_CORE_WRITE_EXTRA_DATA;
1789 #endif
1790
1791         if (file->f_pos != offset) {
1792                 /* Sanity check */
1793                 printk(KERN_WARNING
1794                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1795                        file->f_pos, offset);
1796         }
1797
1798 end_coredump:
1799         set_fs(fs);
1800
1801 cleanup:
1802         while (!list_empty(&thread_list)) {
1803                 struct list_head *tmp = thread_list.next;
1804                 list_del(tmp);
1805                 kfree(list_entry(tmp, struct elf_thread_status, list));
1806         }
1807
1808         kfree(elf);
1809         kfree(prstatus);
1810         kfree(psinfo);
1811         kfree(notes);
1812         kfree(fpu);
1813 #ifdef ELF_CORE_COPY_XFPREGS
1814         kfree(xfpu);
1815 #endif
1816         return has_dumped;
1817 #undef NUM_NOTES
1818 }
1819
1820 #endif          /* USE_ELF_CORE_DUMP */