git.oblomov.eu Git - linux-2.6/blob - 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/smp_lock.h>
  34 #include <linux/elf.h>
  35 #include <linux/elf-fdpic.h>
  36 #include <linux/elfcore.h>
  37
  38 #include <asm/uaccess.h>
  39 #include <asm/param.h>
  40 #include <asm/pgalloc.h>
  41
  42 typedef char *elf_caddr_t;
  43
  44 #if 0
  45 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  46 #else
  47 #define kdebug(fmt, ...) do {} while(0)
  48 #endif
  49
  50 #if 0
  51 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  52 #else
  53 #define kdcore(fmt, ...) do {} while(0)
  54 #endif
  55
  56 MODULE_LICENSE("GPL");
  57
  58 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
  59 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  60 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  61                               struct mm_struct *, const char *);
  62
  63 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  64                                    struct elf_fdpic_params *,
  65                                    struct elf_fdpic_params *);
  66
  67 #ifndef CONFIG_MMU
  68 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
  69                                             unsigned long *);
  70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  71                                                    struct file *,
  72                                                    struct mm_struct *);
  73 #endif
  74
  75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  76                                              struct file *, struct mm_struct *);
  77
  78 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  79 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *);
  80 #endif
  81
  82 static struct linux_binfmt elf_fdpic_format = {
  83         .module         = THIS_MODULE,
  84         .load_binary    = load_elf_fdpic_binary,
  85 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  86         .core_dump      = elf_fdpic_core_dump,
  87 #endif
  88         .min_coredump   = ELF_EXEC_PAGESIZE,
  89 };
  90
  91 static int __init init_elf_fdpic_binfmt(void)
  92 {
  93         return register_binfmt(&elf_fdpic_format);
  94 }
  95
  96 static void __exit exit_elf_fdpic_binfmt(void)
  97 {
  98         unregister_binfmt(&elf_fdpic_format);
  99 }
 100
 101 core_initcall(init_elf_fdpic_binfmt);
 102 module_exit(exit_elf_fdpic_binfmt);
 103
 104 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
 105 {
 106         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 107                 return 0;
 108         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 109                 return 0;
 110         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
 111                 return 0;
 112         if (!file->f_op || !file->f_op->mmap)
 113                 return 0;
 114         return 1;
 115 }
 116
 117 /*****************************************************************************/
 118 /*
 119  * read the program headers table into memory
 120  */
 121 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 122                                  struct file *file)
 123 {
 124         struct elf32_phdr *phdr;
 125         unsigned long size;
 126         int retval, loop;
 127
 128         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 129                 return -ENOMEM;
 130         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 131                 return -ENOMEM;
 132
 133         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 134         params->phdrs = kmalloc(size, GFP_KERNEL);
 135         if (!params->phdrs)
 136                 return -ENOMEM;
 137
 138         retval = kernel_read(file, params->hdr.e_phoff,
 139                              (char *) params->phdrs, size);
 140         if (retval < 0)
 141                 return retval;
 142
 143         /* determine stack size for this binary */
 144         phdr = params->phdrs;
 145         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 146                 if (phdr->p_type != PT_GNU_STACK)
 147                         continue;
 148
 149                 if (phdr->p_flags & PF_X)
 150                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 151                 else
 152                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 153
 154                 params->stack_size = phdr->p_memsz;
 155                 break;
 156         }
 157
 158         return 0;
 159 }
 160
 161 /*****************************************************************************/
 162 /*
 163  * load an fdpic binary into various bits of memory
 164  */
 165 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
 166                                  struct pt_regs *regs)
 167 {
 168         struct elf_fdpic_params exec_params, interp_params;
 169         struct elf_phdr *phdr;
 170         unsigned long stack_size, entryaddr;
 171 #ifndef CONFIG_MMU
 172         unsigned long fullsize;
 173 #endif
 174 #ifdef ELF_FDPIC_PLAT_INIT
 175         unsigned long dynaddr;
 176 #endif
 177         struct file *interpreter = NULL; /* to shut gcc up */
 178         char *interpreter_name = NULL;
 179         int executable_stack;
 180         int retval, i;
 181
 182         kdebug("____ LOAD %d ____", current->pid);
 183
 184         memset(&exec_params, 0, sizeof(exec_params));
 185         memset(&interp_params, 0, sizeof(interp_params));
 186
 187         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 188         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 189
 190         /* check that this is a binary we know how to deal with */
 191         retval = -ENOEXEC;
 192         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
 193                 goto error;
 194
 195         /* read the program header table */
 196         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 197         if (retval < 0)
 198                 goto error;
 199
 200         /* scan for a program header that specifies an interpreter */
 201         phdr = exec_params.phdrs;
 202
 203         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 204                 switch (phdr->p_type) {
 205                 case PT_INTERP:
 206                         retval = -ENOMEM;
 207                         if (phdr->p_filesz > PATH_MAX)
 208                                 goto error;
 209                         retval = -ENOENT;
 210                         if (phdr->p_filesz < 2)
 211                                 goto error;
 212
 213                         /* read the name of the interpreter into memory */
 214                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 215                         if (!interpreter_name)
 216                                 goto error;
 217
 218                         retval = kernel_read(bprm->file,
 219                                              phdr->p_offset,
 220                                              interpreter_name,
 221                                              phdr->p_filesz);
 222                         if (retval < 0)
 223                                 goto error;
 224
 225                         retval = -ENOENT;
 226                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 227                                 goto error;
 228
 229                         kdebug("Using ELF interpreter %s", interpreter_name);
 230
 231                         /* replace the program with the interpreter */
 232                         interpreter = open_exec(interpreter_name);
 233                         retval = PTR_ERR(interpreter);
 234                         if (IS_ERR(interpreter)) {
 235                                 interpreter = NULL;
 236                                 goto error;
 237                         }
 238
 239                         /*
 240                          * If the binary is not readable then enforce
 241                          * mm->dumpable = 0 regardless of the interpreter's
 242                          * permissions.
 243                          */
 244                         if (file_permission(interpreter, MAY_READ) < 0)
 245                                 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
 246
 247                         retval = kernel_read(interpreter, 0, bprm->buf,
 248                                              BINPRM_BUF_SIZE);
 249                         if (retval < 0)
 250                                 goto error;
 251
 252                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 253                         break;
 254
 255                 case PT_LOAD:
 256 #ifdef CONFIG_MMU
 257                         if (exec_params.load_addr == 0)
 258                                 exec_params.load_addr = phdr->p_vaddr;
 259 #endif
 260                         break;
 261                 }
 262
 263         }
 264
 265         if (elf_check_const_displacement(&exec_params.hdr))
 266                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 267
 268         /* perform insanity checks on the interpreter */
 269         if (interpreter_name) {
 270                 retval = -ELIBBAD;
 271                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
 272                         goto error;
 273
 274                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 275
 276                 /* read the interpreter's program header table */
 277                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 278                 if (retval < 0)
 279                         goto error;
 280         }
 281
 282         stack_size = exec_params.stack_size;
 283         if (stack_size < interp_params.stack_size)
 284                 stack_size = interp_params.stack_size;
 285
 286         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 287                 executable_stack = EXSTACK_ENABLE_X;
 288         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 289                 executable_stack = EXSTACK_DISABLE_X;
 290         else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 291                 executable_stack = EXSTACK_ENABLE_X;
 292         else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 293                 executable_stack = EXSTACK_DISABLE_X;
 294         else
 295                 executable_stack = EXSTACK_DEFAULT;
 296
 297         retval = -ENOEXEC;
 298         if (stack_size == 0)
 299                 goto error;
 300
 301         if (elf_check_const_displacement(&interp_params.hdr))
 302                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 303
 304         /* flush all traces of the currently running executable */
 305         retval = flush_old_exec(bprm);
 306         if (retval)
 307                 goto error;
 308
 309         /* there's now no turning back... the old userspace image is dead,
 310          * defunct, deceased, etc. after this point we have to exit via
 311          * error_kill */
 312         set_personality(PER_LINUX_FDPIC);
 313         set_binfmt(&elf_fdpic_format);
 314
 315         current->mm->start_code = 0;
 316         current->mm->end_code = 0;
 317         current->mm->start_stack = 0;
 318         current->mm->start_data = 0;
 319         current->mm->end_data = 0;
 320         current->mm->context.exec_fdpic_loadmap = 0;
 321         current->mm->context.interp_fdpic_loadmap = 0;
 322
 323         current->flags &= ~PF_FORKNOEXEC;
 324
 325 #ifdef CONFIG_MMU
 326         elf_fdpic_arch_lay_out_mm(&exec_params,
 327                                   &interp_params,
 328                                   &current->mm->start_stack,
 329                                   &current->mm->start_brk);
 330
 331         retval = setup_arg_pages(bprm, current->mm->start_stack,
 332                                  executable_stack);
 333         if (retval < 0) {
 334                 send_sig(SIGKILL, current, 0);
 335                 goto error_kill;
 336         }
 337 #endif
 338
 339         /* load the executable and interpreter into memory */
 340         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 341                                     "executable");
 342         if (retval < 0)
 343                 goto error_kill;
 344
 345         if (interpreter_name) {
 346                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 347                                             current->mm, "interpreter");
 348                 if (retval < 0) {
 349                         printk(KERN_ERR "Unable to load interpreter\n");
 350                         goto error_kill;
 351                 }
 352
 353                 allow_write_access(interpreter);
 354                 fput(interpreter);
 355                 interpreter = NULL;
 356         }
 357
 358 #ifdef CONFIG_MMU
 359         if (!current->mm->start_brk)
 360                 current->mm->start_brk = current->mm->end_data;
 361
 362         current->mm->brk = current->mm->start_brk =
 363                 PAGE_ALIGN(current->mm->start_brk);
 364
 365 #else
 366         /* create a stack and brk area big enough for everyone
 367          * - the brk heap starts at the bottom and works up
 368          * - the stack starts at the top and works down
 369          */
 370         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 371         if (stack_size < PAGE_SIZE * 2)
 372                 stack_size = PAGE_SIZE * 2;
 373
 374         down_write(&current->mm->mmap_sem);
 375         current->mm->start_brk = do_mmap(NULL, 0, stack_size,
 376                                          PROT_READ | PROT_WRITE | PROT_EXEC,
 377                                          MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
 378                                          0);
 379
 380         if (IS_ERR_VALUE(current->mm->start_brk)) {
 381                 up_write(&current->mm->mmap_sem);
 382                 retval = current->mm->start_brk;
 383                 current->mm->start_brk = 0;
 384                 goto error_kill;
 385         }
 386
 387         /* expand the stack mapping to use up the entire allocation granule */
 388         fullsize = ksize((char *) current->mm->start_brk);
 389         if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
 390                                     fullsize, 0, 0)))
 391                 stack_size = fullsize;
 392         up_write(&current->mm->mmap_sem);
 393
 394         current->mm->brk = current->mm->start_brk;
 395         current->mm->context.end_brk = current->mm->start_brk;
 396         current->mm->context.end_brk +=
 397                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 398         current->mm->start_stack = current->mm->start_brk + stack_size;
 399 #endif
 400
 401         compute_creds(bprm);
 402         current->flags &= ~PF_FORKNOEXEC;
 403         if (create_elf_fdpic_tables(bprm, current->mm,
 404                                     &exec_params, &interp_params) < 0)
 405                 goto error_kill;
 406
 407         kdebug("- start_code  %lx", current->mm->start_code);
 408         kdebug("- end_code    %lx", current->mm->end_code);
 409         kdebug("- start_data  %lx", current->mm->start_data);
 410         kdebug("- end_data    %lx", current->mm->end_data);
 411         kdebug("- start_brk   %lx", current->mm->start_brk);
 412         kdebug("- brk         %lx", current->mm->brk);
 413         kdebug("- start_stack %lx", current->mm->start_stack);
 414
 415 #ifdef ELF_FDPIC_PLAT_INIT
 416         /*
 417          * The ABI may specify that certain registers be set up in special
 418          * ways (on i386 %edx is the address of a DT_FINI function, for
 419          * example.  This macro performs whatever initialization to
 420          * the regs structure is required.
 421          */
 422         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 423         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 424                             dynaddr);
 425 #endif
 426
 427         /* everything is now ready... get the userspace context ready to roll */
 428         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 429         start_thread(regs, entryaddr, current->mm->start_stack);
 430
 431         if (unlikely(current->ptrace & PT_PTRACED)) {
 432                 if (current->ptrace & PT_TRACE_EXEC)
 433                         ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
 434                 else
 435                         send_sig(SIGTRAP, current, 0);
 436         }
 437
 438         retval = 0;
 439
 440 error:
 441         if (interpreter) {
 442                 allow_write_access(interpreter);
 443                 fput(interpreter);
 444         }
 445         kfree(interpreter_name);
 446         kfree(exec_params.phdrs);
 447         kfree(exec_params.loadmap);
 448         kfree(interp_params.phdrs);
 449         kfree(interp_params.loadmap);
 450         return retval;
 451
 452         /* unrecoverable error - kill the process */
 453 error_kill:
 454         send_sig(SIGSEGV, current, 0);
 455         goto error;
 456
 457 }
 458
 459 /*****************************************************************************/
 460 /*
 461  * present useful information to the program
 462  */
 463 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 464                                    struct mm_struct *mm,
 465                                    struct elf_fdpic_params *exec_params,
 466                                    struct elf_fdpic_params *interp_params)
 467 {
 468         unsigned long sp, csp, nitems;
 469         elf_caddr_t __user *argv, *envp;
 470         size_t platform_len = 0, len;
 471         char *k_platform;
 472         char __user *u_platform, *p;
 473         long hwcap;
 474         int loop;
 475
 476         /* we're going to shovel a whole load of stuff onto the stack */
 477 #ifdef CONFIG_MMU
 478         sp = bprm->p;
 479 #else
 480         sp = mm->start_stack;
 481
 482         /* stack the program arguments and environment */
 483         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 484                 return -EFAULT;
 485 #endif
 486
 487         /* get hold of platform and hardware capabilities masks for the machine
 488          * we are running on.  In some cases (Sparc), this info is impossible
 489          * to get, in others (i386) it is merely difficult.
 490          */
 491         hwcap = ELF_HWCAP;
 492         k_platform = ELF_PLATFORM;
 493         u_platform = NULL;
 494
 495         if (k_platform) {
 496                 platform_len = strlen(k_platform) + 1;
 497                 sp -= platform_len;
 498                 u_platform = (char __user *) sp;
 499                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 500                         return -EFAULT;
 501         }
 502
 503 #if defined(__i386__) && defined(CONFIG_SMP)
 504         /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 505          * by the processes running on the same package. One thing we can do is
 506          * to shuffle the initial stack for them.
 507          *
 508          * the conditionals here are unneeded, but kept in to make the code
 509          * behaviour the same as pre change unless we have hyperthreaded
 510          * processors. This keeps Mr Marcelo Person happier but should be
 511          * removed for 2.5
 512          */
 513         if (smp_num_siblings > 1)
 514                 sp = sp - ((current->pid % 64) << 7);
 515 #endif
 516
 517         sp &= ~7UL;
 518
 519         /* stack the load map(s) */
 520         len = sizeof(struct elf32_fdpic_loadmap);
 521         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 522         sp = (sp - len) & ~7UL;
 523         exec_params->map_addr = sp;
 524
 525         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 526                 return -EFAULT;
 527
 528         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 529
 530         if (interp_params->loadmap) {
 531                 len = sizeof(struct elf32_fdpic_loadmap);
 532                 len += sizeof(struct elf32_fdpic_loadseg) *
 533                         interp_params->loadmap->nsegs;
 534                 sp = (sp - len) & ~7UL;
 535                 interp_params->map_addr = sp;
 536
 537                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 538                                  len) != 0)
 539                         return -EFAULT;
 540
 541                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 542         }
 543
 544         /* force 16 byte _final_ alignment here for generality */
 545 #define DLINFO_ITEMS 13
 546
 547         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
 548 #ifdef DLINFO_ARCH_ITEMS
 549         nitems += DLINFO_ARCH_ITEMS;
 550 #endif
 551
 552         csp = sp;
 553         sp -= nitems * 2 * sizeof(unsigned long);
 554         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 555         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 556         sp -= 1 * sizeof(unsigned long);                /* argc */
 557
 558         csp -= sp & 15UL;
 559         sp -= sp & 15UL;
 560
 561         /* put the ELF interpreter info on the stack */
 562 #define NEW_AUX_ENT(nr, id, val)                                        \
 563         do {                                                            \
 564                 struct { unsigned long _id, _val; } __user *ent;        \
 565                                                                         \
 566                 ent = (void __user *) csp;                              \
 567                 __put_user((id), &ent[nr]._id);                         \
 568                 __put_user((val), &ent[nr]._val);                       \
 569         } while (0)
 570
 571         csp -= 2 * sizeof(unsigned long);
 572         NEW_AUX_ENT(0, AT_NULL, 0);
 573         if (k_platform) {
 574                 csp -= 2 * sizeof(unsigned long);
 575                 NEW_AUX_ENT(0, AT_PLATFORM,
 576                             (elf_addr_t) (unsigned long) u_platform);
 577         }
 578
 579         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 580         NEW_AUX_ENT( 0, AT_HWCAP,       hwcap);
 581         NEW_AUX_ENT( 1, AT_PAGESZ,      PAGE_SIZE);
 582         NEW_AUX_ENT( 2, AT_CLKTCK,      CLOCKS_PER_SEC);
 583         NEW_AUX_ENT( 3, AT_PHDR,        exec_params->ph_addr);
 584         NEW_AUX_ENT( 4, AT_PHENT,       sizeof(struct elf_phdr));
 585         NEW_AUX_ENT( 5, AT_PHNUM,       exec_params->hdr.e_phnum);
 586         NEW_AUX_ENT( 6, AT_BASE,        interp_params->elfhdr_addr);
 587         NEW_AUX_ENT( 7, AT_FLAGS,       0);
 588         NEW_AUX_ENT( 8, AT_ENTRY,       exec_params->entry_addr);
 589         NEW_AUX_ENT( 9, AT_UID,         (elf_addr_t) current->uid);
 590         NEW_AUX_ENT(10, AT_EUID,        (elf_addr_t) current->euid);
 591         NEW_AUX_ENT(11, AT_GID,         (elf_addr_t) current->gid);
 592         NEW_AUX_ENT(12, AT_EGID,        (elf_addr_t) current->egid);
 593
 594 #ifdef ARCH_DLINFO
 595         /* ARCH_DLINFO must come last so platform specific code can enforce
 596          * special alignment requirements on the AUXV if necessary (eg. PPC).
 597          */
 598         ARCH_DLINFO;
 599 #endif
 600 #undef NEW_AUX_ENT
 601
 602         /* allocate room for argv[] and envv[] */
 603         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 604         envp = (elf_caddr_t __user *) csp;
 605         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 606         argv = (elf_caddr_t __user *) csp;
 607
 608         /* stack argc */
 609         csp -= sizeof(unsigned long);
 610         __put_user(bprm->argc, (unsigned long __user *) csp);
 611
 612         BUG_ON(csp != sp);
 613
 614         /* fill in the argv[] array */
 615 #ifdef CONFIG_MMU
 616         current->mm->arg_start = bprm->p;
 617 #else
 618         current->mm->arg_start = current->mm->start_stack -
 619                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 620 #endif
 621
 622         p = (char __user *) current->mm->arg_start;
 623         for (loop = bprm->argc; loop > 0; loop--) {
 624                 __put_user((elf_caddr_t) p, argv++);
 625                 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
 626                 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
 627                         return -EINVAL;
 628                 p += len;
 629         }
 630         __put_user(NULL, argv);
 631         current->mm->arg_end = (unsigned long) p;
 632
 633         /* fill in the envv[] array */
 634         current->mm->env_start = (unsigned long) p;
 635         for (loop = bprm->envc; loop > 0; loop--) {
 636                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 637                 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
 638                 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
 639                         return -EINVAL;
 640                 p += len;
 641         }
 642         __put_user(NULL, envp);
 643         current->mm->env_end = (unsigned long) p;
 644
 645         mm->start_stack = (unsigned long) sp;
 646         return 0;
 647 }
 648
 649 /*****************************************************************************/
 650 /*
 651  * transfer the program arguments and environment from the holding pages onto
 652  * the stack
 653  */
 654 #ifndef CONFIG_MMU
 655 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 656                                             unsigned long *_sp)
 657 {
 658         unsigned long index, stop, sp;
 659         char *src;
 660         int ret = 0;
 661
 662         stop = bprm->p >> PAGE_SHIFT;
 663         sp = *_sp;
 664
 665         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 666                 src = kmap(bprm->page[index]);
 667                 sp -= PAGE_SIZE;
 668                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 669                         ret = -EFAULT;
 670                 kunmap(bprm->page[index]);
 671                 if (ret < 0)
 672                         goto out;
 673         }
 674
 675         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 676
 677 out:
 678         return ret;
 679 }
 680 #endif
 681
 682 /*****************************************************************************/
 683 /*
 684  * load the appropriate binary image (executable or interpreter) into memory
 685  * - we assume no MMU is available
 686  * - if no other PIC bits are set in params->hdr->e_flags
 687  *   - we assume that the LOADable segments in the binary are independently relocatable
 688  *   - we assume R/O executable segments are shareable
 689  * - else
 690  *   - we assume the loadable parts of the image to require fixed displacement
 691  *   - the image is not shareable
 692  */
 693 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 694                               struct file *file,
 695                               struct mm_struct *mm,
 696                               const char *what)
 697 {
 698         struct elf32_fdpic_loadmap *loadmap;
 699 #ifdef CONFIG_MMU
 700         struct elf32_fdpic_loadseg *mseg;
 701 #endif
 702         struct elf32_fdpic_loadseg *seg;
 703         struct elf32_phdr *phdr;
 704         unsigned long load_addr, stop;
 705         unsigned nloads, tmp;
 706         size_t size;
 707         int loop, ret;
 708
 709         /* allocate a load map table */
 710         nloads = 0;
 711         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 712                 if (params->phdrs[loop].p_type == PT_LOAD)
 713                         nloads++;
 714
 715         if (nloads == 0)
 716                 return -ELIBBAD;
 717
 718         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 719         loadmap = kzalloc(size, GFP_KERNEL);
 720         if (!loadmap)
 721                 return -ENOMEM;
 722
 723         params->loadmap = loadmap;
 724
 725         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 726         loadmap->nsegs = nloads;
 727
 728         load_addr = params->load_addr;
 729         seg = loadmap->segs;
 730
 731         /* map the requested LOADs into the memory space */
 732         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 733         case ELF_FDPIC_FLAG_CONSTDISP:
 734         case ELF_FDPIC_FLAG_CONTIGUOUS:
 735 #ifndef CONFIG_MMU
 736                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 737                 if (ret < 0)
 738                         return ret;
 739                 break;
 740 #endif
 741         default:
 742                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 743                 if (ret < 0)
 744                         return ret;
 745                 break;
 746         }
 747
 748         /* map the entry point */
 749         if (params->hdr.e_entry) {
 750                 seg = loadmap->segs;
 751                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 752                         if (params->hdr.e_entry >= seg->p_vaddr &&
 753                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 754                                 params->entry_addr =
 755                                         (params->hdr.e_entry - seg->p_vaddr) +
 756                                         seg->addr;
 757                                 break;
 758                         }
 759                 }
 760         }
 761
 762         /* determine where the program header table has wound up if mapped */
 763         stop = params->hdr.e_phoff;
 764         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 765         phdr = params->phdrs;
 766
 767         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 768                 if (phdr->p_type != PT_LOAD)
 769                         continue;
 770
 771                 if (phdr->p_offset > params->hdr.e_phoff ||
 772                     phdr->p_offset + phdr->p_filesz < stop)
 773                         continue;
 774
 775                 seg = loadmap->segs;
 776                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 777                         if (phdr->p_vaddr >= seg->p_vaddr &&
 778                             phdr->p_vaddr + phdr->p_filesz <=
 779                             seg->p_vaddr + seg->p_memsz) {
 780                                 params->ph_addr =
 781                                         (phdr->p_vaddr - seg->p_vaddr) +
 782                                         seg->addr +
 783                                         params->hdr.e_phoff - phdr->p_offset;
 784                                 break;
 785                         }
 786                 }
 787                 break;
 788         }
 789
 790         /* determine where the dynamic section has wound up if there is one */
 791         phdr = params->phdrs;
 792         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 793                 if (phdr->p_type != PT_DYNAMIC)
 794                         continue;
 795
 796                 seg = loadmap->segs;
 797                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 798                         if (phdr->p_vaddr >= seg->p_vaddr &&
 799                             phdr->p_vaddr + phdr->p_memsz <=
 800                             seg->p_vaddr + seg->p_memsz) {
 801                                 params->dynamic_addr =
 802                                         (phdr->p_vaddr - seg->p_vaddr) +
 803                                         seg->addr;
 804
 805                                 /* check the dynamic section contains at least
 806                                  * one item, and that the last item is a NULL
 807                                  * entry */
 808                                 if (phdr->p_memsz == 0 ||
 809                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 810                                         goto dynamic_error;
 811
 812                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 813                                 if (((Elf32_Dyn *)
 814                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
 815                                         goto dynamic_error;
 816                                 break;
 817                         }
 818                 }
 819                 break;
 820         }
 821
 822         /* now elide adjacent segments in the load map on MMU linux
 823          * - on uClinux the holes between may actually be filled with system
 824          *   stuff or stuff from other processes
 825          */
 826 #ifdef CONFIG_MMU
 827         nloads = loadmap->nsegs;
 828         mseg = loadmap->segs;
 829         seg = mseg + 1;
 830         for (loop = 1; loop < nloads; loop++) {
 831                 /* see if we have a candidate for merging */
 832                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 833                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 834                         if (load_addr == (seg->addr & PAGE_MASK)) {
 835                                 mseg->p_memsz +=
 836                                         load_addr -
 837                                         (mseg->addr + mseg->p_memsz);
 838                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 839                                 mseg->p_memsz += seg->p_memsz;
 840                                 loadmap->nsegs--;
 841                                 continue;
 842                         }
 843                 }
 844
 845                 mseg++;
 846                 if (mseg != seg)
 847                         *mseg = *seg;
 848         }
 849 #endif
 850
 851         kdebug("Mapped Object [%s]:", what);
 852         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 853         kdebug("- entry    : %lx", params->entry_addr);
 854         kdebug("- PHDR[]   : %lx", params->ph_addr);
 855         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 856         seg = loadmap->segs;
 857         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 858                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 859                        loop,
 860                        seg->addr, seg->addr + seg->p_memsz - 1,
 861                        seg->p_vaddr, seg->p_memsz);
 862
 863         return 0;
 864
 865 dynamic_error:
 866         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 867                what, file->f_path.dentry->d_inode->i_ino);
 868         return -ELIBBAD;
 869 }
 870
 871 /*****************************************************************************/
 872 /*
 873  * map a file with constant displacement under uClinux
 874  */
 875 #ifndef CONFIG_MMU
 876 static int elf_fdpic_map_file_constdisp_on_uclinux(
 877         struct elf_fdpic_params *params,
 878         struct file *file,
 879         struct mm_struct *mm)
 880 {
 881         struct elf32_fdpic_loadseg *seg;
 882         struct elf32_phdr *phdr;
 883         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 884         loff_t fpos;
 885         int loop, ret;
 886
 887         load_addr = params->load_addr;
 888         seg = params->loadmap->segs;
 889
 890         /* determine the bounds of the contiguous overall allocation we must
 891          * make */
 892         phdr = params->phdrs;
 893         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 894                 if (params->phdrs[loop].p_type != PT_LOAD)
 895                         continue;
 896
 897                 if (base > phdr->p_vaddr)
 898                         base = phdr->p_vaddr;
 899                 if (top < phdr->p_vaddr + phdr->p_memsz)
 900                         top = phdr->p_vaddr + phdr->p_memsz;
 901         }
 902
 903         /* allocate one big anon block for everything */
 904         mflags = MAP_PRIVATE;
 905         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 906                 mflags |= MAP_EXECUTABLE;
 907
 908         down_write(&mm->mmap_sem);
 909         maddr = do_mmap(NULL, load_addr, top - base,
 910                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 911         up_write(&mm->mmap_sem);
 912         if (IS_ERR_VALUE(maddr))
 913                 return (int) maddr;
 914
 915         if (load_addr != 0)
 916                 load_addr += PAGE_ALIGN(top - base);
 917
 918         /* and then load the file segments into it */
 919         phdr = params->phdrs;
 920         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 921                 if (params->phdrs[loop].p_type != PT_LOAD)
 922                         continue;
 923
 924                 fpos = phdr->p_offset;
 925
 926                 seg->addr = maddr + (phdr->p_vaddr - base);
 927                 seg->p_vaddr = phdr->p_vaddr;
 928                 seg->p_memsz = phdr->p_memsz;
 929
 930                 ret = file->f_op->read(file, (void *) seg->addr,
 931                                        phdr->p_filesz, &fpos);
 932                 if (ret < 0)
 933                         return ret;
 934
 935                 /* map the ELF header address if in this segment */
 936                 if (phdr->p_offset == 0)
 937                         params->elfhdr_addr = seg->addr;
 938
 939                 /* clear any space allocated but not loaded */
 940                 if (phdr->p_filesz < phdr->p_memsz)
 941                         clear_user((void *) (seg->addr + phdr->p_filesz),
 942                                    phdr->p_memsz - phdr->p_filesz);
 943
 944                 if (mm) {
 945                         if (phdr->p_flags & PF_X) {
 946                                 if (!mm->start_code) {
 947                                         mm->start_code = seg->addr;
 948                                         mm->end_code = seg->addr +
 949                                                 phdr->p_memsz;
 950                                 }
 951                         } else if (!mm->start_data) {
 952                                 mm->start_data = seg->addr;
 953 #ifndef CONFIG_MMU
 954                                 mm->end_data = seg->addr + phdr->p_memsz;
 955 #endif
 956                         }
 957
 958 #ifdef CONFIG_MMU
 959                         if (seg->addr + phdr->p_memsz > mm->end_data)
 960                                 mm->end_data = seg->addr + phdr->p_memsz;
 961 #endif
 962                 }
 963
 964                 seg++;
 965         }
 966
 967         return 0;
 968 }
 969 #endif
 970
 971 /*****************************************************************************/
 972 /*
 973  * map a binary by direct mmap() of the individual PT_LOAD segments
 974  */
 975 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
 976                                              struct file *file,
 977                                              struct mm_struct *mm)
 978 {
 979         struct elf32_fdpic_loadseg *seg;
 980         struct elf32_phdr *phdr;
 981         unsigned long load_addr, delta_vaddr;
 982         int loop, dvset;
 983
 984         load_addr = params->load_addr;
 985         delta_vaddr = 0;
 986         dvset = 0;
 987
 988         seg = params->loadmap->segs;
 989
 990         /* deal with each load segment separately */
 991         phdr = params->phdrs;
 992         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 993                 unsigned long maddr, disp, excess, excess1;
 994                 int prot = 0, flags;
 995
 996                 if (phdr->p_type != PT_LOAD)
 997                         continue;
 998
 999                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1000                        (unsigned long) phdr->p_vaddr,
1001                        (unsigned long) phdr->p_offset,
1002                        (unsigned long) phdr->p_filesz,
1003                        (unsigned long) phdr->p_memsz);
1004
1005                 /* determine the mapping parameters */
1006                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1007                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1008                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1009
1010                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1011                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1012                         flags |= MAP_EXECUTABLE;
1013
1014                 maddr = 0;
1015
1016                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1017                 case ELF_FDPIC_FLAG_INDEPENDENT:
1018                         /* PT_LOADs are independently locatable */
1019                         break;
1020
1021                 case ELF_FDPIC_FLAG_HONOURVADDR:
1022                         /* the specified virtual address must be honoured */
1023                         maddr = phdr->p_vaddr;
1024                         flags |= MAP_FIXED;
1025                         break;
1026
1027                 case ELF_FDPIC_FLAG_CONSTDISP:
1028                         /* constant displacement
1029                          * - can be mapped anywhere, but must be mapped as a
1030                          *   unit
1031                          */
1032                         if (!dvset) {
1033                                 maddr = load_addr;
1034                                 delta_vaddr = phdr->p_vaddr;
1035                                 dvset = 1;
1036                         } else {
1037                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1038                                 flags |= MAP_FIXED;
1039                         }
1040                         break;
1041
1042                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1043                         /* contiguity handled later */
1044                         break;
1045
1046                 default:
1047                         BUG();
1048                 }
1049
1050                 maddr &= PAGE_MASK;
1051
1052                 /* create the mapping */
1053                 disp = phdr->p_vaddr & ~PAGE_MASK;
1054                 down_write(&mm->mmap_sem);
1055                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1056                                 phdr->p_offset - disp);
1057                 up_write(&mm->mmap_sem);
1058
1059                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1060                        loop, phdr->p_memsz + disp, prot, flags,
1061                        phdr->p_offset - disp, maddr);
1062
1063                 if (IS_ERR_VALUE(maddr))
1064                         return (int) maddr;
1065
1066                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1067                     ELF_FDPIC_FLAG_CONTIGUOUS)
1068                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1069
1070                 seg->addr = maddr + disp;
1071                 seg->p_vaddr = phdr->p_vaddr;
1072                 seg->p_memsz = phdr->p_memsz;
1073
1074                 /* map the ELF header address if in this segment */
1075                 if (phdr->p_offset == 0)
1076                         params->elfhdr_addr = seg->addr;
1077
1078                 /* clear the bit between beginning of mapping and beginning of
1079                  * PT_LOAD */
1080                 if (prot & PROT_WRITE && disp > 0) {
1081                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1082                         clear_user((void __user *) maddr, disp);
1083                         maddr += disp;
1084                 }
1085
1086                 /* clear any space allocated but not loaded
1087                  * - on uClinux we can just clear the lot
1088                  * - on MMU linux we'll get a SIGBUS beyond the last page
1089                  *   extant in the file
1090                  */
1091                 excess = phdr->p_memsz - phdr->p_filesz;
1092                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1093
1094 #ifdef CONFIG_MMU
1095                 if (excess > excess1) {
1096                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1097                         unsigned long xmaddr;
1098
1099                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1100                         down_write(&mm->mmap_sem);
1101                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1102                                          prot, flags, 0);
1103                         up_write(&mm->mmap_sem);
1104
1105                         kdebug("mmap[%d] <anon>"
1106                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1107                                loop, xaddr, excess - excess1, prot, flags,
1108                                xmaddr);
1109
1110                         if (xmaddr != xaddr)
1111                                 return -ENOMEM;
1112                 }
1113
1114                 if (prot & PROT_WRITE && excess1 > 0) {
1115                         kdebug("clear[%d] ad=%lx sz=%lx",
1116                                loop, maddr + phdr->p_filesz, excess1);
1117                         clear_user((void __user *) maddr + phdr->p_filesz,
1118                                    excess1);
1119                 }
1120
1121 #else
1122                 if (excess > 0) {
1123                         kdebug("clear[%d] ad=%lx sz=%lx",
1124                                loop, maddr + phdr->p_filesz, excess);
1125                         clear_user((void *) maddr + phdr->p_filesz, excess);
1126                 }
1127 #endif
1128
1129                 if (mm) {
1130                         if (phdr->p_flags & PF_X) {
1131                                 if (!mm->start_code) {
1132                                         mm->start_code = maddr;
1133                                         mm->end_code = maddr + phdr->p_memsz;
1134                                 }
1135                         } else if (!mm->start_data) {
1136                                 mm->start_data = maddr;
1137                                 mm->end_data = maddr + phdr->p_memsz;
1138                         }
1139                 }
1140
1141                 seg++;
1142         }
1143
1144         return 0;
1145 }
1146
1147 /*****************************************************************************/
1148 /*
1149  * ELF-FDPIC core dumper
1150  *
1151  * Modelled on fs/exec.c:aout_core_dump()
1152  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1153  *
1154  * Modelled on fs/binfmt_elf.c core dumper
1155  */
1156 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1157
1158 /*
1159  * These are the only things you should do on a core-file: use only these
1160  * functions to write out all the necessary info.
1161  */
1162 static int dump_write(struct file *file, const void *addr, int nr)
1163 {
1164         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1165 }
1166
1167 static int dump_seek(struct file *file, loff_t off)
1168 {
1169         if (file->f_op->llseek) {
1170                 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1171                         return 0;
1172         } else {
1173                 file->f_pos = off;
1174         }
1175         return 1;
1176 }
1177
1178 /*
1179  * Decide whether a segment is worth dumping; default is yes to be
1180  * sure (missing info is worse than too much; etc).
1181  * Personally I'd include everything, and use the coredump limit...
1182  *
1183  * I think we should skip something. But I am not sure how. H.J.
1184  */
1185 static int maydump(struct vm_area_struct *vma)
1186 {
1187         /* Do not dump I/O mapped devices or special mappings */
1188         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1189                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1190                 return 0;
1191         }
1192
1193         /* If we may not read the contents, don't allow us to dump
1194          * them either. "dump_write()" can't handle it anyway.
1195          */
1196         if (!(vma->vm_flags & VM_READ)) {
1197                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1198                 return 0;
1199         }
1200
1201         /* Dump shared memory only if mapped from an anonymous file. */
1202         if (vma->vm_flags & VM_SHARED) {
1203                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1204                         kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1205                         return 1;
1206                 }
1207
1208                 kdcore("%08lx: %08lx: no (share)", vma->vm_start, vma->vm_flags);
1209                 return 0;
1210         }
1211
1212 #ifdef CONFIG_MMU
1213         /* If it hasn't been written to, don't write it out */
1214         if (!vma->anon_vma) {
1215                 kdcore("%08lx: %08lx: no (!anon)", vma->vm_start, vma->vm_flags);
1216                 return 0;
1217         }
1218 #endif
1219
1220         kdcore("%08lx: %08lx: yes", vma->vm_start, vma->vm_flags);
1221         return 1;
1222 }
1223
1224 /* An ELF note in memory */
1225 struct memelfnote
1226 {
1227         const char *name;
1228         int type;
1229         unsigned int datasz;
1230         void *data;
1231 };
1232
1233 static int notesize(struct memelfnote *en)
1234 {
1235         int sz;
1236
1237         sz = sizeof(struct elf_note);
1238         sz += roundup(strlen(en->name) + 1, 4);
1239         sz += roundup(en->datasz, 4);
1240
1241         return sz;
1242 }
1243
1244 /* #define DEBUG */
1245
1246 #define DUMP_WRITE(addr, nr)    \
1247         do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1248 #define DUMP_SEEK(off)  \
1249         do { if (!dump_seek(file, (off))) return 0; } while(0)
1250
1251 static int writenote(struct memelfnote *men, struct file *file)
1252 {
1253         struct elf_note en;
1254
1255         en.n_namesz = strlen(men->name) + 1;
1256         en.n_descsz = men->datasz;
1257         en.n_type = men->type;
1258
1259         DUMP_WRITE(&en, sizeof(en));
1260         DUMP_WRITE(men->name, en.n_namesz);
1261         /* XXX - cast from long long to long to avoid need for libgcc.a */
1262         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1263         DUMP_WRITE(men->data, men->datasz);
1264         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1265
1266         return 1;
1267 }
1268 #undef DUMP_WRITE
1269 #undef DUMP_SEEK
1270
1271 #define DUMP_WRITE(addr, nr)    \
1272         if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1273                 goto end_coredump;
1274 #define DUMP_SEEK(off)  \
1275         if (!dump_seek(file, (off))) \
1276                 goto end_coredump;
1277
1278 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1279 {
1280         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1281         elf->e_ident[EI_CLASS] = ELF_CLASS;
1282         elf->e_ident[EI_DATA] = ELF_DATA;
1283         elf->e_ident[EI_VERSION] = EV_CURRENT;
1284         elf->e_ident[EI_OSABI] = ELF_OSABI;
1285         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1286
1287         elf->e_type = ET_CORE;
1288         elf->e_machine = ELF_ARCH;
1289         elf->e_version = EV_CURRENT;
1290         elf->e_entry = 0;
1291         elf->e_phoff = sizeof(struct elfhdr);
1292         elf->e_shoff = 0;
1293         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1294         elf->e_ehsize = sizeof(struct elfhdr);
1295         elf->e_phentsize = sizeof(struct elf_phdr);
1296         elf->e_phnum = segs;
1297         elf->e_shentsize = 0;
1298         elf->e_shnum = 0;
1299         elf->e_shstrndx = 0;
1300         return;
1301 }
1302
1303 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1304 {
1305         phdr->p_type = PT_NOTE;
1306         phdr->p_offset = offset;
1307         phdr->p_vaddr = 0;
1308         phdr->p_paddr = 0;
1309         phdr->p_filesz = sz;
1310         phdr->p_memsz = 0;
1311         phdr->p_flags = 0;
1312         phdr->p_align = 0;
1313         return;
1314 }
1315
1316 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1317                 unsigned int sz, void *data)
1318 {
1319         note->name = name;
1320         note->type = type;
1321         note->datasz = sz;
1322         note->data = data;
1323         return;
1324 }
1325
1326 /*
1327  * fill up all the fields in prstatus from the given task struct, except
1328  * registers which need to be filled up seperately.
1329  */
1330 static void fill_prstatus(struct elf_prstatus *prstatus,
1331                           struct task_struct *p, long signr)
1332 {
1333         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1334         prstatus->pr_sigpend = p->pending.signal.sig[0];
1335         prstatus->pr_sighold = p->blocked.sig[0];
1336         prstatus->pr_pid = p->pid;
1337         prstatus->pr_ppid = p->parent->pid;
1338         prstatus->pr_pgrp = process_group(p);
1339         prstatus->pr_sid = process_session(p);
1340         if (thread_group_leader(p)) {
1341                 /*
1342                  * This is the record for the group leader.  Add in the
1343                  * cumulative times of previous dead threads.  This total
1344                  * won't include the time of each live thread whose state
1345                  * is included in the core dump.  The final total reported
1346                  * to our parent process when it calls wait4 will include
1347                  * those sums as well as the little bit more time it takes
1348                  * this and each other thread to finish dying after the
1349                  * core dump synchronization phase.
1350                  */
1351                 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1352                                    &prstatus->pr_utime);
1353                 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1354                                    &prstatus->pr_stime);
1355         } else {
1356                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1357                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1358         }
1359         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1360         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1361
1362         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1363         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1364 }
1365
1366 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1367                        struct mm_struct *mm)
1368 {
1369         unsigned int i, len;
1370
1371         /* first copy the parameters from user space */
1372         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1373
1374         len = mm->arg_end - mm->arg_start;
1375         if (len >= ELF_PRARGSZ)
1376                 len = ELF_PRARGSZ - 1;
1377         if (copy_from_user(&psinfo->pr_psargs,
1378                            (const char __user *) mm->arg_start, len))
1379                 return -EFAULT;
1380         for (i = 0; i < len; i++)
1381                 if (psinfo->pr_psargs[i] == 0)
1382                         psinfo->pr_psargs[i] = ' ';
1383         psinfo->pr_psargs[len] = 0;
1384
1385         psinfo->pr_pid = p->pid;
1386         psinfo->pr_ppid = p->parent->pid;
1387         psinfo->pr_pgrp = process_group(p);
1388         psinfo->pr_sid = process_session(p);
1389
1390         i = p->state ? ffz(~p->state) + 1 : 0;
1391         psinfo->pr_state = i;
1392         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1393         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1394         psinfo->pr_nice = task_nice(p);
1395         psinfo->pr_flag = p->flags;
1396         SET_UID(psinfo->pr_uid, p->uid);
1397         SET_GID(psinfo->pr_gid, p->gid);
1398         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1399
1400         return 0;
1401 }
1402
1403 /* Here is the structure in which status of each thread is captured. */
1404 struct elf_thread_status
1405 {
1406         struct list_head list;
1407         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1408         elf_fpregset_t fpu;             /* NT_PRFPREG */
1409         struct task_struct *thread;
1410 #ifdef ELF_CORE_COPY_XFPREGS
1411         elf_fpxregset_t xfpu;           /* NT_PRXFPREG */
1412 #endif
1413         struct memelfnote notes[3];
1414         int num_notes;
1415 };
1416
1417 /*
1418  * In order to add the specific thread information for the elf file format,
1419  * we need to keep a linked list of every thread's pr_status and then create
1420  * a single section for them in the final core file.
1421  */
1422 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1423 {
1424         struct task_struct *p = t->thread;
1425         int sz = 0;
1426
1427         t->num_notes = 0;
1428
1429         fill_prstatus(&t->prstatus, p, signr);
1430         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1431
1432         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1433                   &t->prstatus);
1434         t->num_notes++;
1435         sz += notesize(&t->notes[0]);
1436
1437         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1438         if (t->prstatus.pr_fpvalid) {
1439                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1440                           &t->fpu);
1441                 t->num_notes++;
1442                 sz += notesize(&t->notes[1]);
1443         }
1444
1445 #ifdef ELF_CORE_COPY_XFPREGS
1446         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1447                 fill_note(&t->notes[2], "LINUX", NT_PRXFPREG, sizeof(t->xfpu),
1448                           &t->xfpu);
1449                 t->num_notes++;
1450                 sz += notesize(&t->notes[2]);
1451         }
1452 #endif
1453         return sz;
1454 }
1455
1456 /*
1457  * dump the segments for an MMU process
1458  */
1459 #ifdef CONFIG_MMU
1460 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1461                                    size_t *size, unsigned long *limit)
1462 {
1463         struct vm_area_struct *vma;
1464
1465         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1466                 unsigned long addr;
1467
1468                 if (!maydump(vma))
1469                         continue;
1470
1471                 for (addr = vma->vm_start;
1472                      addr < vma->vm_end;
1473                      addr += PAGE_SIZE
1474                      ) {
1475                         struct vm_area_struct *vma;
1476                         struct page *page;
1477
1478                         if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1479                                            &page, &vma) <= 0) {
1480                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1481                         }
1482                         else if (page == ZERO_PAGE(addr)) {
1483                                 page_cache_release(page);
1484                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1485                         }
1486                         else {
1487                                 void *kaddr;
1488
1489                                 flush_cache_page(vma, addr, page_to_pfn(page));
1490                                 kaddr = kmap(page);
1491                                 if ((*size += PAGE_SIZE) > *limit ||
1492                                     !dump_write(file, kaddr, PAGE_SIZE)
1493                                     ) {
1494                                         kunmap(page);
1495                                         page_cache_release(page);
1496                                         return -EIO;
1497                                 }
1498                                 kunmap(page);
1499                                 page_cache_release(page);
1500                         }
1501                 }
1502         }
1503
1504         return 0;
1505
1506 end_coredump:
1507         return -EFBIG;
1508 }
1509 #endif
1510
1511 /*
1512  * dump the segments for a NOMMU process
1513  */
1514 #ifndef CONFIG_MMU
1515 static int elf_fdpic_dump_segments(struct file *file, struct mm_struct *mm,
1516                                    size_t *size, unsigned long *limit)
1517 {
1518         struct vm_list_struct *vml;
1519
1520         for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1521         struct vm_area_struct *vma = vml->vma;
1522
1523                 if (!maydump(vma))
1524                         continue;
1525
1526                 if ((*size += PAGE_SIZE) > *limit)
1527                         return -EFBIG;
1528
1529                 if (!dump_write(file, (void *) vma->vm_start,
1530                                 vma->vm_end - vma->vm_start))
1531                         return -EIO;
1532         }
1533
1534         return 0;
1535 }
1536 #endif
1537
1538 /*
1539  * Actual dumper
1540  *
1541  * This is a two-pass process; first we find the offsets of the bits,
1542  * and then they are actually written out.  If we run out of core limit
1543  * we just truncate.
1544  */
1545 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1546                                struct file *file)
1547 {
1548 #define NUM_NOTES       6
1549         int has_dumped = 0;
1550         mm_segment_t fs;
1551         int segs;
1552         size_t size = 0;
1553         int i;
1554         struct vm_area_struct *vma;
1555         struct elfhdr *elf = NULL;
1556         loff_t offset = 0, dataoff;
1557         unsigned long limit = current->signal->rlim[RLIMIT_CORE].rlim_cur;
1558         int numnote;
1559         struct memelfnote *notes = NULL;
1560         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1561         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1562         struct task_struct *g, *p;
1563         LIST_HEAD(thread_list);
1564         struct list_head *t;
1565         elf_fpregset_t *fpu = NULL;
1566 #ifdef ELF_CORE_COPY_XFPREGS
1567         elf_fpxregset_t *xfpu = NULL;
1568 #endif
1569         int thread_status_size = 0;
1570 #ifndef CONFIG_MMU
1571         struct vm_list_struct *vml;
1572 #endif
1573         elf_addr_t *auxv;
1574
1575         /*
1576          * We no longer stop all VM operations.
1577          *
1578          * This is because those proceses that could possibly change map_count
1579          * or the mmap / vma pages are now blocked in do_exit on current
1580          * finishing this core dump.
1581          *
1582          * Only ptrace can touch these memory addresses, but it doesn't change
1583          * the map_count or the pages allocated. So no possibility of crashing
1584          * exists while dumping the mm->vm_next areas to the core file.
1585          */
1586
1587         /* alloc memory for large data structures: too large to be on stack */
1588         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1589         if (!elf)
1590                 goto cleanup;
1591         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1592         if (!prstatus)
1593                 goto cleanup;
1594         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1595         if (!psinfo)
1596                 goto cleanup;
1597         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1598         if (!notes)
1599                 goto cleanup;
1600         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1601         if (!fpu)
1602                 goto cleanup;
1603 #ifdef ELF_CORE_COPY_XFPREGS
1604         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1605         if (!xfpu)
1606                 goto cleanup;
1607 #endif
1608
1609         if (signr) {
1610                 struct elf_thread_status *tmp;
1611                 rcu_read_lock();
1612                 do_each_thread(g,p)
1613                         if (current->mm == p->mm && current != p) {
1614                                 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1615                                 if (!tmp) {
1616                                         rcu_read_unlock();
1617                                         goto cleanup;
1618                                 }
1619                                 tmp->thread = p;
1620                                 list_add(&tmp->list, &thread_list);
1621                         }
1622                 while_each_thread(g,p);
1623                 rcu_read_unlock();
1624                 list_for_each(t, &thread_list) {
1625                         struct elf_thread_status *tmp;
1626                         int sz;
1627
1628                         tmp = list_entry(t, struct elf_thread_status, list);
1629                         sz = elf_dump_thread_status(signr, tmp);
1630                         thread_status_size += sz;
1631                 }
1632         }
1633
1634         /* now collect the dump for the current */
1635         fill_prstatus(prstatus, current, signr);
1636         elf_core_copy_regs(&prstatus->pr_reg, regs);
1637
1638 #ifdef CONFIG_MMU
1639         segs = current->mm->map_count;
1640 #else
1641         segs = 0;
1642         for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1643             segs++;
1644 #endif
1645 #ifdef ELF_CORE_EXTRA_PHDRS
1646         segs += ELF_CORE_EXTRA_PHDRS;
1647 #endif
1648
1649         /* Set up header */
1650         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1651
1652         has_dumped = 1;
1653         current->flags |= PF_DUMPCORE;
1654
1655         /*
1656          * Set up the notes in similar form to SVR4 core dumps made
1657          * with info from their /proc.
1658          */
1659
1660         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1661         fill_psinfo(psinfo, current->group_leader, current->mm);
1662         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1663
1664         numnote = 2;
1665
1666         auxv = (elf_addr_t *) current->mm->saved_auxv;
1667
1668         i = 0;
1669         do
1670                 i += 2;
1671         while (auxv[i - 2] != AT_NULL);
1672         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1673                   i * sizeof(elf_addr_t), auxv);
1674
1675         /* Try to dump the FPU. */
1676         if ((prstatus->pr_fpvalid =
1677              elf_core_copy_task_fpregs(current, regs, fpu)))
1678                 fill_note(notes + numnote++,
1679                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1680 #ifdef ELF_CORE_COPY_XFPREGS
1681         if (elf_core_copy_task_xfpregs(current, xfpu))
1682                 fill_note(notes + numnote++,
1683                           "LINUX", NT_PRXFPREG, sizeof(*xfpu), xfpu);
1684 #endif
1685
1686         fs = get_fs();
1687         set_fs(KERNEL_DS);
1688
1689         DUMP_WRITE(elf, sizeof(*elf));
1690         offset += sizeof(*elf);                         /* Elf header */
1691         offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1692
1693         /* Write notes phdr entry */
1694         {
1695                 struct elf_phdr phdr;
1696                 int sz = 0;
1697
1698                 for (i = 0; i < numnote; i++)
1699                         sz += notesize(notes + i);
1700
1701                 sz += thread_status_size;
1702
1703                 fill_elf_note_phdr(&phdr, sz, offset);
1704                 offset += sz;
1705                 DUMP_WRITE(&phdr, sizeof(phdr));
1706         }
1707
1708         /* Page-align dumped data */
1709         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1710
1711         /* write program headers for segments dump */
1712         for (
1713 #ifdef CONFIG_MMU
1714                 vma = current->mm->mmap; vma; vma = vma->vm_next
1715 #else
1716                         vml = current->mm->context.vmlist; vml; vml = vml->next
1717 #endif
1718              ) {
1719                 struct elf_phdr phdr;
1720                 size_t sz;
1721
1722 #ifndef CONFIG_MMU
1723                 vma = vml->vma;
1724 #endif
1725
1726                 sz = vma->vm_end - vma->vm_start;
1727
1728                 phdr.p_type = PT_LOAD;
1729                 phdr.p_offset = offset;
1730                 phdr.p_vaddr = vma->vm_start;
1731                 phdr.p_paddr = 0;
1732                 phdr.p_filesz = maydump(vma) ? sz : 0;
1733                 phdr.p_memsz = sz;
1734                 offset += phdr.p_filesz;
1735                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1736                 if (vma->vm_flags & VM_WRITE)
1737                         phdr.p_flags |= PF_W;
1738                 if (vma->vm_flags & VM_EXEC)
1739                         phdr.p_flags |= PF_X;
1740                 phdr.p_align = ELF_EXEC_PAGESIZE;
1741
1742                 DUMP_WRITE(&phdr, sizeof(phdr));
1743         }
1744
1745 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1746         ELF_CORE_WRITE_EXTRA_PHDRS;
1747 #endif
1748
1749         /* write out the notes section */
1750         for (i = 0; i < numnote; i++)
1751                 if (!writenote(notes + i, file))
1752                         goto end_coredump;
1753
1754         /* write out the thread status notes section */
1755         list_for_each(t, &thread_list) {
1756                 struct elf_thread_status *tmp =
1757                                 list_entry(t, struct elf_thread_status, list);
1758
1759                 for (i = 0; i < tmp->num_notes; i++)
1760                         if (!writenote(&tmp->notes[i], file))
1761                                 goto end_coredump;
1762         }
1763
1764         DUMP_SEEK(dataoff);
1765
1766         if (elf_fdpic_dump_segments(file, current->mm, &size, &limit) < 0)
1767                 goto end_coredump;
1768
1769 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1770         ELF_CORE_WRITE_EXTRA_DATA;
1771 #endif
1772
1773         if (file->f_pos != offset) {
1774                 /* Sanity check */
1775                 printk(KERN_WARNING
1776                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1777                        file->f_pos, offset);
1778         }
1779
1780 end_coredump:
1781         set_fs(fs);
1782
1783 cleanup:
1784         while (!list_empty(&thread_list)) {
1785                 struct list_head *tmp = thread_list.next;
1786                 list_del(tmp);
1787                 kfree(list_entry(tmp, struct elf_thread_status, list));
1788         }
1789
1790         kfree(elf);
1791         kfree(prstatus);
1792         kfree(psinfo);
1793         kfree(notes);
1794         kfree(fpu);
1795 #ifdef ELF_CORE_COPY_XFPREGS
1796         kfree(xfpu);
1797 #endif
1798         return has_dumped;
1799 #undef NUM_NOTES
1800 }
1801
1802 #endif          /* USE_ELF_CORE_DUMP */