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