SAFE public projects git trees. - safe/jmp/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/security.h>
  29 #include <linux/highmem.h>
  30 #include <linux/highuid.h>
  31 #include <linux/personality.h>
  32 #include <linux/ptrace.h>
  33 #include <linux/init.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 *, unsigned long limit);
  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 (unlikely(retval != size))
 141                 return retval < 0 ? retval : -ENOEXEC;
 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 #ifdef ELF_FDPIC_PLAT_INIT
 172         unsigned long dynaddr;
 173 #endif
 174         struct file *interpreter = NULL; /* to shut gcc up */
 175         char *interpreter_name = NULL;
 176         int executable_stack;
 177         int retval, i;
 178
 179         kdebug("____ LOAD %d ____", current->pid);
 180
 181         memset(&exec_params, 0, sizeof(exec_params));
 182         memset(&interp_params, 0, sizeof(interp_params));
 183
 184         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 185         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 186
 187         /* check that this is a binary we know how to deal with */
 188         retval = -ENOEXEC;
 189         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
 190                 goto error;
 191
 192         /* read the program header table */
 193         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 194         if (retval < 0)
 195                 goto error;
 196
 197         /* scan for a program header that specifies an interpreter */
 198         phdr = exec_params.phdrs;
 199
 200         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 201                 switch (phdr->p_type) {
 202                 case PT_INTERP:
 203                         retval = -ENOMEM;
 204                         if (phdr->p_filesz > PATH_MAX)
 205                                 goto error;
 206                         retval = -ENOENT;
 207                         if (phdr->p_filesz < 2)
 208                                 goto error;
 209
 210                         /* read the name of the interpreter into memory */
 211                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 212                         if (!interpreter_name)
 213                                 goto error;
 214
 215                         retval = kernel_read(bprm->file,
 216                                              phdr->p_offset,
 217                                              interpreter_name,
 218                                              phdr->p_filesz);
 219                         if (unlikely(retval != phdr->p_filesz)) {
 220                                 if (retval >= 0)
 221                                         retval = -ENOEXEC;
 222                                 goto error;
 223                         }
 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 (unlikely(retval != BINPRM_BUF_SIZE)) {
 250                                 if (retval >= 0)
 251                                         retval = -ENOEXEC;
 252                                 goto error;
 253                         }
 254
 255                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 256                         break;
 257
 258                 case PT_LOAD:
 259 #ifdef CONFIG_MMU
 260                         if (exec_params.load_addr == 0)
 261                                 exec_params.load_addr = phdr->p_vaddr;
 262 #endif
 263                         break;
 264                 }
 265
 266         }
 267
 268         if (elf_check_const_displacement(&exec_params.hdr))
 269                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 270
 271         /* perform insanity checks on the interpreter */
 272         if (interpreter_name) {
 273                 retval = -ELIBBAD;
 274                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
 275                         goto error;
 276
 277                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 278
 279                 /* read the interpreter's program header table */
 280                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 281                 if (retval < 0)
 282                         goto error;
 283         }
 284
 285         stack_size = exec_params.stack_size;
 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
 291                 executable_stack = EXSTACK_DEFAULT;
 292
 293         if (stack_size == 0) {
 294                 stack_size = interp_params.stack_size;
 295                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 296                         executable_stack = EXSTACK_ENABLE_X;
 297                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 298                         executable_stack = EXSTACK_DISABLE_X;
 299                 else
 300                         executable_stack = EXSTACK_DEFAULT;
 301         }
 302
 303         retval = -ENOEXEC;
 304         if (stack_size == 0)
 305                 goto error;
 306
 307         if (elf_check_const_displacement(&interp_params.hdr))
 308                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 309
 310         /* flush all traces of the currently running executable */
 311         retval = flush_old_exec(bprm);
 312         if (retval)
 313                 goto error;
 314
 315         /* there's now no turning back... the old userspace image is dead,
 316          * defunct, deceased, etc. after this point we have to exit via
 317          * error_kill */
 318         set_personality(PER_LINUX_FDPIC);
 319         set_binfmt(&elf_fdpic_format);
 320
 321         current->mm->start_code = 0;
 322         current->mm->end_code = 0;
 323         current->mm->start_stack = 0;
 324         current->mm->start_data = 0;
 325         current->mm->end_data = 0;
 326         current->mm->context.exec_fdpic_loadmap = 0;
 327         current->mm->context.interp_fdpic_loadmap = 0;
 328
 329         current->flags &= ~PF_FORKNOEXEC;
 330
 331 #ifdef CONFIG_MMU
 332         elf_fdpic_arch_lay_out_mm(&exec_params,
 333                                   &interp_params,
 334                                   &current->mm->start_stack,
 335                                   &current->mm->start_brk);
 336
 337         retval = setup_arg_pages(bprm, current->mm->start_stack,
 338                                  executable_stack);
 339         if (retval < 0) {
 340                 send_sig(SIGKILL, current, 0);
 341                 goto error_kill;
 342         }
 343 #endif
 344
 345         /* load the executable and interpreter into memory */
 346         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 347                                     "executable");
 348         if (retval < 0)
 349                 goto error_kill;
 350
 351         if (interpreter_name) {
 352                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 353                                             current->mm, "interpreter");
 354                 if (retval < 0) {
 355                         printk(KERN_ERR "Unable to load interpreter\n");
 356                         goto error_kill;
 357                 }
 358
 359                 allow_write_access(interpreter);
 360                 fput(interpreter);
 361                 interpreter = NULL;
 362         }
 363
 364 #ifdef CONFIG_MMU
 365         if (!current->mm->start_brk)
 366                 current->mm->start_brk = current->mm->end_data;
 367
 368         current->mm->brk = current->mm->start_brk =
 369                 PAGE_ALIGN(current->mm->start_brk);
 370
 371 #else
 372         /* create a stack and brk area big enough for everyone
 373          * - the brk heap starts at the bottom and works up
 374          * - the stack starts at the top and works down
 375          */
 376         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 377         if (stack_size < PAGE_SIZE * 2)
 378                 stack_size = PAGE_SIZE * 2;
 379
 380         down_write(&current->mm->mmap_sem);
 381         current->mm->start_brk = do_mmap(NULL, 0, stack_size,
 382                                          PROT_READ | PROT_WRITE | PROT_EXEC,
 383                                          MAP_PRIVATE | MAP_ANONYMOUS |
 384                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
 385                                          0);
 386
 387         if (IS_ERR_VALUE(current->mm->start_brk)) {
 388                 up_write(&current->mm->mmap_sem);
 389                 retval = current->mm->start_brk;
 390                 current->mm->start_brk = 0;
 391                 goto error_kill;
 392         }
 393
 394         up_write(&current->mm->mmap_sem);
 395
 396         current->mm->brk = current->mm->start_brk;
 397         current->mm->context.end_brk = current->mm->start_brk;
 398         current->mm->context.end_brk +=
 399                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 400         current->mm->start_stack = current->mm->start_brk + stack_size;
 401 #endif
 402
 403         install_exec_creds(bprm);
 404         current->flags &= ~PF_FORKNOEXEC;
 405         if (create_elf_fdpic_tables(bprm, current->mm,
 406                                     &exec_params, &interp_params) < 0)
 407                 goto error_kill;
 408
 409         kdebug("- start_code  %lx", current->mm->start_code);
 410         kdebug("- end_code    %lx", current->mm->end_code);
 411         kdebug("- start_data  %lx", current->mm->start_data);
 412         kdebug("- end_data    %lx", current->mm->end_data);
 413         kdebug("- start_brk   %lx", current->mm->start_brk);
 414         kdebug("- brk         %lx", current->mm->brk);
 415         kdebug("- start_stack %lx", current->mm->start_stack);
 416
 417 #ifdef ELF_FDPIC_PLAT_INIT
 418         /*
 419          * The ABI may specify that certain registers be set up in special
 420          * ways (on i386 %edx is the address of a DT_FINI function, for
 421          * example.  This macro performs whatever initialization to
 422          * the regs structure is required.
 423          */
 424         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 425         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 426                             dynaddr);
 427 #endif
 428
 429         /* everything is now ready... get the userspace context ready to roll */
 430         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 431         start_thread(regs, entryaddr, current->mm->start_stack);
 432
 433         retval = 0;
 434
 435 error:
 436         if (interpreter) {
 437                 allow_write_access(interpreter);
 438                 fput(interpreter);
 439         }
 440         kfree(interpreter_name);
 441         kfree(exec_params.phdrs);
 442         kfree(exec_params.loadmap);
 443         kfree(interp_params.phdrs);
 444         kfree(interp_params.loadmap);
 445         return retval;
 446
 447         /* unrecoverable error - kill the process */
 448 error_kill:
 449         send_sig(SIGSEGV, current, 0);
 450         goto error;
 451
 452 }
 453
 454 /*****************************************************************************/
 455
 456 #ifndef ELF_BASE_PLATFORM
 457 /*
 458  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 459  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 460  * will be copied to the user stack in the same manner as AT_PLATFORM.
 461  */
 462 #define ELF_BASE_PLATFORM NULL
 463 #endif
 464
 465 /*
 466  * present useful information to the program by shovelling it onto the new
 467  * process's stack
 468  */
 469 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 470                                    struct mm_struct *mm,
 471                                    struct elf_fdpic_params *exec_params,
 472                                    struct elf_fdpic_params *interp_params)
 473 {
 474         const struct cred *cred = current_cred();
 475         unsigned long sp, csp, nitems;
 476         elf_caddr_t __user *argv, *envp;
 477         size_t platform_len = 0, len;
 478         char *k_platform, *k_base_platform;
 479         char __user *u_platform, *u_base_platform, *p;
 480         long hwcap;
 481         int loop;
 482         int nr; /* reset for each csp adjustment */
 483
 484 #ifdef CONFIG_MMU
 485         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 486          * by the processes running on the same package. One thing we can do is
 487          * to shuffle the initial stack for them, so we give the architecture
 488          * an opportunity to do so here.
 489          */
 490         sp = arch_align_stack(bprm->p);
 491 #else
 492         sp = mm->start_stack;
 493
 494         /* stack the program arguments and environment */
 495         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 496                 return -EFAULT;
 497 #endif
 498
 499         hwcap = ELF_HWCAP;
 500
 501         /*
 502          * If this architecture has a platform capability string, copy it
 503          * to userspace.  In some cases (Sparc), this info is impossible
 504          * for userspace to get any other way, in others (i386) it is
 505          * merely difficult.
 506          */
 507         k_platform = ELF_PLATFORM;
 508         u_platform = NULL;
 509
 510         if (k_platform) {
 511                 platform_len = strlen(k_platform) + 1;
 512                 sp -= platform_len;
 513                 u_platform = (char __user *) sp;
 514                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 515                         return -EFAULT;
 516         }
 517
 518         /*
 519          * If this architecture has a "base" platform capability
 520          * string, copy it to userspace.
 521          */
 522         k_base_platform = ELF_BASE_PLATFORM;
 523         u_base_platform = NULL;
 524
 525         if (k_base_platform) {
 526                 platform_len = strlen(k_base_platform) + 1;
 527                 sp -= platform_len;
 528                 u_base_platform = (char __user *) sp;
 529                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 530                         return -EFAULT;
 531         }
 532
 533         sp &= ~7UL;
 534
 535         /* stack the load map(s) */
 536         len = sizeof(struct elf32_fdpic_loadmap);
 537         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 538         sp = (sp - len) & ~7UL;
 539         exec_params->map_addr = sp;
 540
 541         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 542                 return -EFAULT;
 543
 544         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 545
 546         if (interp_params->loadmap) {
 547                 len = sizeof(struct elf32_fdpic_loadmap);
 548                 len += sizeof(struct elf32_fdpic_loadseg) *
 549                         interp_params->loadmap->nsegs;
 550                 sp = (sp - len) & ~7UL;
 551                 interp_params->map_addr = sp;
 552
 553                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 554                                  len) != 0)
 555                         return -EFAULT;
 556
 557                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 558         }
 559
 560         /* force 16 byte _final_ alignment here for generality */
 561 #define DLINFO_ITEMS 15
 562
 563         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 564                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 565
 566         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
 567                 nitems++;
 568
 569         csp = sp;
 570         sp -= nitems * 2 * sizeof(unsigned long);
 571         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 572         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 573         sp -= 1 * sizeof(unsigned long);                /* argc */
 574
 575         csp -= sp & 15UL;
 576         sp -= sp & 15UL;
 577
 578         /* put the ELF interpreter info on the stack */
 579 #define NEW_AUX_ENT(id, val)                                            \
 580         do {                                                            \
 581                 struct { unsigned long _id, _val; } __user *ent;        \
 582                                                                         \
 583                 ent = (void __user *) csp;                              \
 584                 __put_user((id), &ent[nr]._id);                         \
 585                 __put_user((val), &ent[nr]._val);                       \
 586                 nr++;                                                   \
 587         } while (0)
 588
 589         nr = 0;
 590         csp -= 2 * sizeof(unsigned long);
 591         NEW_AUX_ENT(AT_NULL, 0);
 592         if (k_platform) {
 593                 nr = 0;
 594                 csp -= 2 * sizeof(unsigned long);
 595                 NEW_AUX_ENT(AT_PLATFORM,
 596                             (elf_addr_t) (unsigned long) u_platform);
 597         }
 598
 599         if (k_base_platform) {
 600                 nr = 0;
 601                 csp -= 2 * sizeof(unsigned long);
 602                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 603                             (elf_addr_t) (unsigned long) u_base_platform);
 604         }
 605
 606         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 607                 nr = 0;
 608                 csp -= 2 * sizeof(unsigned long);
 609                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 610         }
 611
 612         nr = 0;
 613         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 614         NEW_AUX_ENT(AT_HWCAP,   hwcap);
 615         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 616         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 617         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 618         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 619         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 620         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 621         NEW_AUX_ENT(AT_FLAGS,   0);
 622         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 623         NEW_AUX_ENT(AT_UID,     (elf_addr_t) cred->uid);
 624         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) cred->euid);
 625         NEW_AUX_ENT(AT_GID,     (elf_addr_t) cred->gid);
 626         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) cred->egid);
 627         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
 628         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 629
 630 #ifdef ARCH_DLINFO
 631         nr = 0;
 632         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 633
 634         /* ARCH_DLINFO must come last so platform specific code can enforce
 635          * special alignment requirements on the AUXV if necessary (eg. PPC).
 636          */
 637         ARCH_DLINFO;
 638 #endif
 639 #undef NEW_AUX_ENT
 640
 641         /* allocate room for argv[] and envv[] */
 642         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 643         envp = (elf_caddr_t __user *) csp;
 644         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 645         argv = (elf_caddr_t __user *) csp;
 646
 647         /* stack argc */
 648         csp -= sizeof(unsigned long);
 649         __put_user(bprm->argc, (unsigned long __user *) csp);
 650
 651         BUG_ON(csp != sp);
 652
 653         /* fill in the argv[] array */
 654 #ifdef CONFIG_MMU
 655         current->mm->arg_start = bprm->p;
 656 #else
 657         current->mm->arg_start = current->mm->start_stack -
 658                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 659 #endif
 660
 661         p = (char __user *) current->mm->arg_start;
 662         for (loop = bprm->argc; loop > 0; loop--) {
 663                 __put_user((elf_caddr_t) p, argv++);
 664                 len = strnlen_user(p, MAX_ARG_STRLEN);
 665                 if (!len || len > MAX_ARG_STRLEN)
 666                         return -EINVAL;
 667                 p += len;
 668         }
 669         __put_user(NULL, argv);
 670         current->mm->arg_end = (unsigned long) p;
 671
 672         /* fill in the envv[] array */
 673         current->mm->env_start = (unsigned long) p;
 674         for (loop = bprm->envc; loop > 0; loop--) {
 675                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 676                 len = strnlen_user(p, MAX_ARG_STRLEN);
 677                 if (!len || len > MAX_ARG_STRLEN)
 678                         return -EINVAL;
 679                 p += len;
 680         }
 681         __put_user(NULL, envp);
 682         current->mm->env_end = (unsigned long) p;
 683
 684         mm->start_stack = (unsigned long) sp;
 685         return 0;
 686 }
 687
 688 /*****************************************************************************/
 689 /*
 690  * transfer the program arguments and environment from the holding pages onto
 691  * the stack
 692  */
 693 #ifndef CONFIG_MMU
 694 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 695                                             unsigned long *_sp)
 696 {
 697         unsigned long index, stop, sp;
 698         char *src;
 699         int ret = 0;
 700
 701         stop = bprm->p >> PAGE_SHIFT;
 702         sp = *_sp;
 703
 704         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 705                 src = kmap(bprm->page[index]);
 706                 sp -= PAGE_SIZE;
 707                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 708                         ret = -EFAULT;
 709                 kunmap(bprm->page[index]);
 710                 if (ret < 0)
 711                         goto out;
 712         }
 713
 714         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 715
 716 out:
 717         return ret;
 718 }
 719 #endif
 720
 721 /*****************************************************************************/
 722 /*
 723  * load the appropriate binary image (executable or interpreter) into memory
 724  * - we assume no MMU is available
 725  * - if no other PIC bits are set in params->hdr->e_flags
 726  *   - we assume that the LOADable segments in the binary are independently relocatable
 727  *   - we assume R/O executable segments are shareable
 728  * - else
 729  *   - we assume the loadable parts of the image to require fixed displacement
 730  *   - the image is not shareable
 731  */
 732 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 733                               struct file *file,
 734                               struct mm_struct *mm,
 735                               const char *what)
 736 {
 737         struct elf32_fdpic_loadmap *loadmap;
 738 #ifdef CONFIG_MMU
 739         struct elf32_fdpic_loadseg *mseg;
 740 #endif
 741         struct elf32_fdpic_loadseg *seg;
 742         struct elf32_phdr *phdr;
 743         unsigned long load_addr, stop;
 744         unsigned nloads, tmp;
 745         size_t size;
 746         int loop, ret;
 747
 748         /* allocate a load map table */
 749         nloads = 0;
 750         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 751                 if (params->phdrs[loop].p_type == PT_LOAD)
 752                         nloads++;
 753
 754         if (nloads == 0)
 755                 return -ELIBBAD;
 756
 757         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 758         loadmap = kzalloc(size, GFP_KERNEL);
 759         if (!loadmap)
 760                 return -ENOMEM;
 761
 762         params->loadmap = loadmap;
 763
 764         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 765         loadmap->nsegs = nloads;
 766
 767         load_addr = params->load_addr;
 768         seg = loadmap->segs;
 769
 770         /* map the requested LOADs into the memory space */
 771         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 772         case ELF_FDPIC_FLAG_CONSTDISP:
 773         case ELF_FDPIC_FLAG_CONTIGUOUS:
 774 #ifndef CONFIG_MMU
 775                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 776                 if (ret < 0)
 777                         return ret;
 778                 break;
 779 #endif
 780         default:
 781                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 782                 if (ret < 0)
 783                         return ret;
 784                 break;
 785         }
 786
 787         /* map the entry point */
 788         if (params->hdr.e_entry) {
 789                 seg = loadmap->segs;
 790                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 791                         if (params->hdr.e_entry >= seg->p_vaddr &&
 792                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 793                                 params->entry_addr =
 794                                         (params->hdr.e_entry - seg->p_vaddr) +
 795                                         seg->addr;
 796                                 break;
 797                         }
 798                 }
 799         }
 800
 801         /* determine where the program header table has wound up if mapped */
 802         stop = params->hdr.e_phoff;
 803         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 804         phdr = params->phdrs;
 805
 806         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 807                 if (phdr->p_type != PT_LOAD)
 808                         continue;
 809
 810                 if (phdr->p_offset > params->hdr.e_phoff ||
 811                     phdr->p_offset + phdr->p_filesz < stop)
 812                         continue;
 813
 814                 seg = loadmap->segs;
 815                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 816                         if (phdr->p_vaddr >= seg->p_vaddr &&
 817                             phdr->p_vaddr + phdr->p_filesz <=
 818                             seg->p_vaddr + seg->p_memsz) {
 819                                 params->ph_addr =
 820                                         (phdr->p_vaddr - seg->p_vaddr) +
 821                                         seg->addr +
 822                                         params->hdr.e_phoff - phdr->p_offset;
 823                                 break;
 824                         }
 825                 }
 826                 break;
 827         }
 828
 829         /* determine where the dynamic section has wound up if there is one */
 830         phdr = params->phdrs;
 831         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 832                 if (phdr->p_type != PT_DYNAMIC)
 833                         continue;
 834
 835                 seg = loadmap->segs;
 836                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 837                         if (phdr->p_vaddr >= seg->p_vaddr &&
 838                             phdr->p_vaddr + phdr->p_memsz <=
 839                             seg->p_vaddr + seg->p_memsz) {
 840                                 params->dynamic_addr =
 841                                         (phdr->p_vaddr - seg->p_vaddr) +
 842                                         seg->addr;
 843
 844                                 /* check the dynamic section contains at least
 845                                  * one item, and that the last item is a NULL
 846                                  * entry */
 847                                 if (phdr->p_memsz == 0 ||
 848                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 849                                         goto dynamic_error;
 850
 851                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 852                                 if (((Elf32_Dyn *)
 853                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
 854                                         goto dynamic_error;
 855                                 break;
 856                         }
 857                 }
 858                 break;
 859         }
 860
 861         /* now elide adjacent segments in the load map on MMU linux
 862          * - on uClinux the holes between may actually be filled with system
 863          *   stuff or stuff from other processes
 864          */
 865 #ifdef CONFIG_MMU
 866         nloads = loadmap->nsegs;
 867         mseg = loadmap->segs;
 868         seg = mseg + 1;
 869         for (loop = 1; loop < nloads; loop++) {
 870                 /* see if we have a candidate for merging */
 871                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 872                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 873                         if (load_addr == (seg->addr & PAGE_MASK)) {
 874                                 mseg->p_memsz +=
 875                                         load_addr -
 876                                         (mseg->addr + mseg->p_memsz);
 877                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 878                                 mseg->p_memsz += seg->p_memsz;
 879                                 loadmap->nsegs--;
 880                                 continue;
 881                         }
 882                 }
 883
 884                 mseg++;
 885                 if (mseg != seg)
 886                         *mseg = *seg;
 887         }
 888 #endif
 889
 890         kdebug("Mapped Object [%s]:", what);
 891         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 892         kdebug("- entry    : %lx", params->entry_addr);
 893         kdebug("- PHDR[]   : %lx", params->ph_addr);
 894         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 895         seg = loadmap->segs;
 896         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 897                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 898                        loop,
 899                        seg->addr, seg->addr + seg->p_memsz - 1,
 900                        seg->p_vaddr, seg->p_memsz);
 901
 902         return 0;
 903
 904 dynamic_error:
 905         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 906                what, file->f_path.dentry->d_inode->i_ino);
 907         return -ELIBBAD;
 908 }
 909
 910 /*****************************************************************************/
 911 /*
 912  * map a file with constant displacement under uClinux
 913  */
 914 #ifndef CONFIG_MMU
 915 static int elf_fdpic_map_file_constdisp_on_uclinux(
 916         struct elf_fdpic_params *params,
 917         struct file *file,
 918         struct mm_struct *mm)
 919 {
 920         struct elf32_fdpic_loadseg *seg;
 921         struct elf32_phdr *phdr;
 922         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 923         loff_t fpos;
 924         int loop, ret;
 925
 926         load_addr = params->load_addr;
 927         seg = params->loadmap->segs;
 928
 929         /* determine the bounds of the contiguous overall allocation we must
 930          * make */
 931         phdr = params->phdrs;
 932         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 933                 if (params->phdrs[loop].p_type != PT_LOAD)
 934                         continue;
 935
 936                 if (base > phdr->p_vaddr)
 937                         base = phdr->p_vaddr;
 938                 if (top < phdr->p_vaddr + phdr->p_memsz)
 939                         top = phdr->p_vaddr + phdr->p_memsz;
 940         }
 941
 942         /* allocate one big anon block for everything */
 943         mflags = MAP_PRIVATE;
 944         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 945                 mflags |= MAP_EXECUTABLE;
 946
 947         down_write(&mm->mmap_sem);
 948         maddr = do_mmap(NULL, load_addr, top - base,
 949                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 950         up_write(&mm->mmap_sem);
 951         if (IS_ERR_VALUE(maddr))
 952                 return (int) maddr;
 953
 954         if (load_addr != 0)
 955                 load_addr += PAGE_ALIGN(top - base);
 956
 957         /* and then load the file segments into it */
 958         phdr = params->phdrs;
 959         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 960                 if (params->phdrs[loop].p_type != PT_LOAD)
 961                         continue;
 962
 963                 fpos = phdr->p_offset;
 964
 965                 seg->addr = maddr + (phdr->p_vaddr - base);
 966                 seg->p_vaddr = phdr->p_vaddr;
 967                 seg->p_memsz = phdr->p_memsz;
 968
 969                 ret = file->f_op->read(file, (void *) seg->addr,
 970                                        phdr->p_filesz, &fpos);
 971                 if (ret < 0)
 972                         return ret;
 973
 974                 /* map the ELF header address if in this segment */
 975                 if (phdr->p_offset == 0)
 976                         params->elfhdr_addr = seg->addr;
 977
 978                 /* clear any space allocated but not loaded */
 979                 if (phdr->p_filesz < phdr->p_memsz) {
 980                         ret = clear_user((void *) (seg->addr + phdr->p_filesz),
 981                                          phdr->p_memsz - phdr->p_filesz);
 982                         if (ret)
 983                                 return ret;
 984                 }
 985
 986                 if (mm) {
 987                         if (phdr->p_flags & PF_X) {
 988                                 if (!mm->start_code) {
 989                                         mm->start_code = seg->addr;
 990                                         mm->end_code = seg->addr +
 991                                                 phdr->p_memsz;
 992                                 }
 993                         } else if (!mm->start_data) {
 994                                 mm->start_data = seg->addr;
 995 #ifndef CONFIG_MMU
 996                                 mm->end_data = seg->addr + phdr->p_memsz;
 997 #endif
 998                         }
 999
1000 #ifdef CONFIG_MMU
1001                         if (seg->addr + phdr->p_memsz > mm->end_data)
1002                                 mm->end_data = seg->addr + phdr->p_memsz;
1003 #endif
1004                 }
1005
1006                 seg++;
1007         }
1008
1009         return 0;
1010 }
1011 #endif
1012
1013 /*****************************************************************************/
1014 /*
1015  * map a binary by direct mmap() of the individual PT_LOAD segments
1016  */
1017 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1018                                              struct file *file,
1019                                              struct mm_struct *mm)
1020 {
1021         struct elf32_fdpic_loadseg *seg;
1022         struct elf32_phdr *phdr;
1023         unsigned long load_addr, delta_vaddr;
1024         int loop, dvset, ret;
1025
1026         load_addr = params->load_addr;
1027         delta_vaddr = 0;
1028         dvset = 0;
1029
1030         seg = params->loadmap->segs;
1031
1032         /* deal with each load segment separately */
1033         phdr = params->phdrs;
1034         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1035                 unsigned long maddr, disp, excess, excess1;
1036                 int prot = 0, flags;
1037
1038                 if (phdr->p_type != PT_LOAD)
1039                         continue;
1040
1041                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1042                        (unsigned long) phdr->p_vaddr,
1043                        (unsigned long) phdr->p_offset,
1044                        (unsigned long) phdr->p_filesz,
1045                        (unsigned long) phdr->p_memsz);
1046
1047                 /* determine the mapping parameters */
1048                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1049                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1050                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1051
1052                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1053                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1054                         flags |= MAP_EXECUTABLE;
1055
1056                 maddr = 0;
1057
1058                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1059                 case ELF_FDPIC_FLAG_INDEPENDENT:
1060                         /* PT_LOADs are independently locatable */
1061                         break;
1062
1063                 case ELF_FDPIC_FLAG_HONOURVADDR:
1064                         /* the specified virtual address must be honoured */
1065                         maddr = phdr->p_vaddr;
1066                         flags |= MAP_FIXED;
1067                         break;
1068
1069                 case ELF_FDPIC_FLAG_CONSTDISP:
1070                         /* constant displacement
1071                          * - can be mapped anywhere, but must be mapped as a
1072                          *   unit
1073                          */
1074                         if (!dvset) {
1075                                 maddr = load_addr;
1076                                 delta_vaddr = phdr->p_vaddr;
1077                                 dvset = 1;
1078                         } else {
1079                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1080                                 flags |= MAP_FIXED;
1081                         }
1082                         break;
1083
1084                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1085                         /* contiguity handled later */
1086                         break;
1087
1088                 default:
1089                         BUG();
1090                 }
1091
1092                 maddr &= PAGE_MASK;
1093
1094                 /* create the mapping */
1095                 disp = phdr->p_vaddr & ~PAGE_MASK;
1096                 down_write(&mm->mmap_sem);
1097                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1098                                 phdr->p_offset - disp);
1099                 up_write(&mm->mmap_sem);
1100
1101                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1102                        loop, phdr->p_memsz + disp, prot, flags,
1103                        phdr->p_offset - disp, maddr);
1104
1105                 if (IS_ERR_VALUE(maddr))
1106                         return (int) maddr;
1107
1108                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1109                     ELF_FDPIC_FLAG_CONTIGUOUS)
1110                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1111
1112                 seg->addr = maddr + disp;
1113                 seg->p_vaddr = phdr->p_vaddr;
1114                 seg->p_memsz = phdr->p_memsz;
1115
1116                 /* map the ELF header address if in this segment */
1117                 if (phdr->p_offset == 0)
1118                         params->elfhdr_addr = seg->addr;
1119
1120                 /* clear the bit between beginning of mapping and beginning of
1121                  * PT_LOAD */
1122                 if (prot & PROT_WRITE && disp > 0) {
1123                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1124                         ret = clear_user((void __user *) maddr, disp);
1125                         if (ret)
1126                                 return ret;
1127                         maddr += disp;
1128                 }
1129
1130                 /* clear any space allocated but not loaded
1131                  * - on uClinux we can just clear the lot
1132                  * - on MMU linux we'll get a SIGBUS beyond the last page
1133                  *   extant in the file
1134                  */
1135                 excess = phdr->p_memsz - phdr->p_filesz;
1136                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1137
1138 #ifdef CONFIG_MMU
1139                 if (excess > excess1) {
1140                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1141                         unsigned long xmaddr;
1142
1143                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1144                         down_write(&mm->mmap_sem);
1145                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1146                                          prot, flags, 0);
1147                         up_write(&mm->mmap_sem);
1148
1149                         kdebug("mmap[%d] <anon>"
1150                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1151                                loop, xaddr, excess - excess1, prot, flags,
1152                                xmaddr);
1153
1154                         if (xmaddr != xaddr)
1155                                 return -ENOMEM;
1156                 }
1157
1158                 if (prot & PROT_WRITE && excess1 > 0) {
1159                         kdebug("clear[%d] ad=%lx sz=%lx",
1160                                loop, maddr + phdr->p_filesz, excess1);
1161                         ret = clear_user((void __user *) maddr + phdr->p_filesz,
1162                                          excess1);
1163                         if (ret)
1164                                 return ret;
1165                 }
1166
1167 #else
1168                 if (excess > 0) {
1169                         kdebug("clear[%d] ad=%lx sz=%lx",
1170                                loop, maddr + phdr->p_filesz, excess);
1171                         ret = clear_user((void *) maddr + phdr->p_filesz, excess);
1172                         if (ret)
1173                                 return ret;
1174                 }
1175 #endif
1176
1177                 if (mm) {
1178                         if (phdr->p_flags & PF_X) {
1179                                 if (!mm->start_code) {
1180                                         mm->start_code = maddr;
1181                                         mm->end_code = maddr + phdr->p_memsz;
1182                                 }
1183                         } else if (!mm->start_data) {
1184                                 mm->start_data = maddr;
1185                                 mm->end_data = maddr + phdr->p_memsz;
1186                         }
1187                 }
1188
1189                 seg++;
1190         }
1191
1192         return 0;
1193 }
1194
1195 /*****************************************************************************/
1196 /*
1197  * ELF-FDPIC core dumper
1198  *
1199  * Modelled on fs/exec.c:aout_core_dump()
1200  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1201  *
1202  * Modelled on fs/binfmt_elf.c core dumper
1203  */
1204 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1205
1206 /*
1207  * These are the only things you should do on a core-file: use only these
1208  * functions to write out all the necessary info.
1209  */
1210 static int dump_write(struct file *file, const void *addr, int nr)
1211 {
1212         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1213 }
1214
1215 static int dump_seek(struct file *file, loff_t off)
1216 {
1217         if (file->f_op->llseek) {
1218                 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1219                         return 0;
1220         } else {
1221                 file->f_pos = off;
1222         }
1223         return 1;
1224 }
1225
1226 /*
1227  * Decide whether a segment is worth dumping; default is yes to be
1228  * sure (missing info is worse than too much; etc).
1229  * Personally I'd include everything, and use the coredump limit...
1230  *
1231  * I think we should skip something. But I am not sure how. H.J.
1232  */
1233 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1234 {
1235         int dump_ok;
1236
1237         /* Do not dump I/O mapped devices or special mappings */
1238         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1239                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1240                 return 0;
1241         }
1242
1243         /* If we may not read the contents, don't allow us to dump
1244          * them either. "dump_write()" can't handle it anyway.
1245          */
1246         if (!(vma->vm_flags & VM_READ)) {
1247                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1248                 return 0;
1249         }
1250
1251         /* By default, dump shared memory if mapped from an anonymous file. */
1252         if (vma->vm_flags & VM_SHARED) {
1253                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1254                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1255                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1256                                vma->vm_flags, dump_ok ? "yes" : "no");
1257                         return dump_ok;
1258                 }
1259
1260                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1261                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1262                        vma->vm_flags, dump_ok ? "yes" : "no");
1263                 return dump_ok;
1264         }
1265
1266 #ifdef CONFIG_MMU
1267         /* By default, if it hasn't been written to, don't write it out */
1268         if (!vma->anon_vma) {
1269                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1270                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1271                        vma->vm_flags, dump_ok ? "yes" : "no");
1272                 return dump_ok;
1273         }
1274 #endif
1275
1276         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1277         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1278                dump_ok ? "yes" : "no");
1279         return dump_ok;
1280 }
1281
1282 /* An ELF note in memory */
1283 struct memelfnote
1284 {
1285         const char *name;
1286         int type;
1287         unsigned int datasz;
1288         void *data;
1289 };
1290
1291 static int notesize(struct memelfnote *en)
1292 {
1293         int sz;
1294
1295         sz = sizeof(struct elf_note);
1296         sz += roundup(strlen(en->name) + 1, 4);
1297         sz += roundup(en->datasz, 4);
1298
1299         return sz;
1300 }
1301
1302 /* #define DEBUG */
1303
1304 #define DUMP_WRITE(addr, nr)    \
1305         do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1306 #define DUMP_SEEK(off)  \
1307         do { if (!dump_seek(file, (off))) return 0; } while(0)
1308
1309 static int writenote(struct memelfnote *men, struct file *file)
1310 {
1311         struct elf_note en;
1312
1313         en.n_namesz = strlen(men->name) + 1;
1314         en.n_descsz = men->datasz;
1315         en.n_type = men->type;
1316
1317         DUMP_WRITE(&en, sizeof(en));
1318         DUMP_WRITE(men->name, en.n_namesz);
1319         /* XXX - cast from long long to long to avoid need for libgcc.a */
1320         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1321         DUMP_WRITE(men->data, men->datasz);
1322         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1323
1324         return 1;
1325 }
1326 #undef DUMP_WRITE
1327 #undef DUMP_SEEK
1328
1329 #define DUMP_WRITE(addr, nr)    \
1330         if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1331                 goto end_coredump;
1332
1333 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1334 {
1335         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1336         elf->e_ident[EI_CLASS] = ELF_CLASS;
1337         elf->e_ident[EI_DATA] = ELF_DATA;
1338         elf->e_ident[EI_VERSION] = EV_CURRENT;
1339         elf->e_ident[EI_OSABI] = ELF_OSABI;
1340         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1341
1342         elf->e_type = ET_CORE;
1343         elf->e_machine = ELF_ARCH;
1344         elf->e_version = EV_CURRENT;
1345         elf->e_entry = 0;
1346         elf->e_phoff = sizeof(struct elfhdr);
1347         elf->e_shoff = 0;
1348         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1349         elf->e_ehsize = sizeof(struct elfhdr);
1350         elf->e_phentsize = sizeof(struct elf_phdr);
1351         elf->e_phnum = segs;
1352         elf->e_shentsize = 0;
1353         elf->e_shnum = 0;
1354         elf->e_shstrndx = 0;
1355         return;
1356 }
1357
1358 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1359 {
1360         phdr->p_type = PT_NOTE;
1361         phdr->p_offset = offset;
1362         phdr->p_vaddr = 0;
1363         phdr->p_paddr = 0;
1364         phdr->p_filesz = sz;
1365         phdr->p_memsz = 0;
1366         phdr->p_flags = 0;
1367         phdr->p_align = 0;
1368         return;
1369 }
1370
1371 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1372                 unsigned int sz, void *data)
1373 {
1374         note->name = name;
1375         note->type = type;
1376         note->datasz = sz;
1377         note->data = data;
1378         return;
1379 }
1380
1381 /*
1382  * fill up all the fields in prstatus from the given task struct, except
1383  * registers which need to be filled up seperately.
1384  */
1385 static void fill_prstatus(struct elf_prstatus *prstatus,
1386                           struct task_struct *p, long signr)
1387 {
1388         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1389         prstatus->pr_sigpend = p->pending.signal.sig[0];
1390         prstatus->pr_sighold = p->blocked.sig[0];
1391         rcu_read_lock();
1392         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1393         rcu_read_unlock();
1394         prstatus->pr_pid = task_pid_vnr(p);
1395         prstatus->pr_pgrp = task_pgrp_vnr(p);
1396         prstatus->pr_sid = task_session_vnr(p);
1397         if (thread_group_leader(p)) {
1398                 struct task_cputime cputime;
1399
1400                 /*
1401                  * This is the record for the group leader.  It shows the
1402                  * group-wide total, not its individual thread total.
1403                  */
1404                 thread_group_cputime(p, &cputime);
1405                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1406                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1407         } else {
1408                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1409                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1410         }
1411         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1412         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1413
1414         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1415         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1416 }
1417
1418 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1419                        struct mm_struct *mm)
1420 {
1421         const struct cred *cred;
1422         unsigned int i, len;
1423
1424         /* first copy the parameters from user space */
1425         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1426
1427         len = mm->arg_end - mm->arg_start;
1428         if (len >= ELF_PRARGSZ)
1429                 len = ELF_PRARGSZ - 1;
1430         if (copy_from_user(&psinfo->pr_psargs,
1431                            (const char __user *) mm->arg_start, len))
1432                 return -EFAULT;
1433         for (i = 0; i < len; i++)
1434                 if (psinfo->pr_psargs[i] == 0)
1435                         psinfo->pr_psargs[i] = ' ';
1436         psinfo->pr_psargs[len] = 0;
1437
1438         rcu_read_lock();
1439         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1440         rcu_read_unlock();
1441         psinfo->pr_pid = task_pid_vnr(p);
1442         psinfo->pr_pgrp = task_pgrp_vnr(p);
1443         psinfo->pr_sid = task_session_vnr(p);
1444
1445         i = p->state ? ffz(~p->state) + 1 : 0;
1446         psinfo->pr_state = i;
1447         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1448         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1449         psinfo->pr_nice = task_nice(p);
1450         psinfo->pr_flag = p->flags;
1451         rcu_read_lock();
1452         cred = __task_cred(p);
1453         SET_UID(psinfo->pr_uid, cred->uid);
1454         SET_GID(psinfo->pr_gid, cred->gid);
1455         rcu_read_unlock();
1456         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1457
1458         return 0;
1459 }
1460
1461 /* Here is the structure in which status of each thread is captured. */
1462 struct elf_thread_status
1463 {
1464         struct list_head list;
1465         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1466         elf_fpregset_t fpu;             /* NT_PRFPREG */
1467         struct task_struct *thread;
1468 #ifdef ELF_CORE_COPY_XFPREGS
1469         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1470 #endif
1471         struct memelfnote notes[3];
1472         int num_notes;
1473 };
1474
1475 /*
1476  * In order to add the specific thread information for the elf file format,
1477  * we need to keep a linked list of every thread's pr_status and then create
1478  * a single section for them in the final core file.
1479  */
1480 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1481 {
1482         struct task_struct *p = t->thread;
1483         int sz = 0;
1484
1485         t->num_notes = 0;
1486
1487         fill_prstatus(&t->prstatus, p, signr);
1488         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1489
1490         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1491                   &t->prstatus);
1492         t->num_notes++;
1493         sz += notesize(&t->notes[0]);
1494
1495         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1496         if (t->prstatus.pr_fpvalid) {
1497                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1498                           &t->fpu);
1499                 t->num_notes++;
1500                 sz += notesize(&t->notes[1]);
1501         }
1502
1503 #ifdef ELF_CORE_COPY_XFPREGS
1504         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1505                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1506                           sizeof(t->xfpu), &t->xfpu);
1507                 t->num_notes++;
1508                 sz += notesize(&t->notes[2]);
1509         }
1510 #endif
1511         return sz;
1512 }
1513
1514 /*
1515  * dump the segments for an MMU process
1516  */
1517 #ifdef CONFIG_MMU
1518 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1519                            unsigned long *limit, unsigned long mm_flags)
1520 {
1521         struct vm_area_struct *vma;
1522         int err = 0;
1523
1524         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1525                 unsigned long addr;
1526
1527                 if (!maydump(vma, mm_flags))
1528                         continue;
1529
1530                 for (addr = vma->vm_start; addr < vma->vm_end;
1531                                                         addr += PAGE_SIZE) {
1532                         struct page *page = get_dump_page(addr);
1533                         if (page) {
1534                                 void *kaddr = kmap(page);
1535                                 *size += PAGE_SIZE;
1536                                 if (*size > *limit)
1537                                         err = -EFBIG;
1538                                 else if (!dump_write(file, kaddr, PAGE_SIZE))
1539                                         err = -EIO;
1540                                 kunmap(page);
1541                                 page_cache_release(page);
1542                         } else if (!dump_seek(file, file->f_pos + PAGE_SIZE))
1543                                 err = -EFBIG;
1544                         if (err)
1545                                 goto out;
1546                 }
1547         }
1548 out:
1549         return err;
1550 }
1551 #endif
1552
1553 /*
1554  * dump the segments for a NOMMU process
1555  */
1556 #ifndef CONFIG_MMU
1557 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1558                            unsigned long *limit, unsigned long mm_flags)
1559 {
1560         struct vm_area_struct *vma;
1561
1562         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1563                 if (!maydump(vma, mm_flags))
1564                         continue;
1565
1566                 if ((*size += PAGE_SIZE) > *limit)
1567                         return -EFBIG;
1568
1569                 if (!dump_write(file, (void *) vma->vm_start,
1570                                 vma->vm_end - vma->vm_start))
1571                         return -EIO;
1572         }
1573
1574         return 0;
1575 }
1576 #endif
1577
1578 /*
1579  * Actual dumper
1580  *
1581  * This is a two-pass process; first we find the offsets of the bits,
1582  * and then they are actually written out.  If we run out of core limit
1583  * we just truncate.
1584  */
1585 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1586                                struct file *file, unsigned long limit)
1587 {
1588 #define NUM_NOTES       6
1589         int has_dumped = 0;
1590         mm_segment_t fs;
1591         int segs;
1592         size_t size = 0;
1593         int i;
1594         struct vm_area_struct *vma;
1595         struct elfhdr *elf = NULL;
1596         loff_t offset = 0, dataoff;
1597         int numnote;
1598         struct memelfnote *notes = NULL;
1599         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1600         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1601         LIST_HEAD(thread_list);
1602         struct list_head *t;
1603         elf_fpregset_t *fpu = NULL;
1604 #ifdef ELF_CORE_COPY_XFPREGS
1605         elf_fpxregset_t *xfpu = NULL;
1606 #endif
1607         int thread_status_size = 0;
1608         elf_addr_t *auxv;
1609         unsigned long mm_flags;
1610
1611         /*
1612          * We no longer stop all VM operations.
1613          *
1614          * This is because those proceses that could possibly change map_count
1615          * or the mmap / vma pages are now blocked in do_exit on current
1616          * finishing this core dump.
1617          *
1618          * Only ptrace can touch these memory addresses, but it doesn't change
1619          * the map_count or the pages allocated. So no possibility of crashing
1620          * exists while dumping the mm->vm_next areas to the core file.
1621          */
1622
1623         /* alloc memory for large data structures: too large to be on stack */
1624         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1625         if (!elf)
1626                 goto cleanup;
1627         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1628         if (!prstatus)
1629                 goto cleanup;
1630         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1631         if (!psinfo)
1632                 goto cleanup;
1633         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1634         if (!notes)
1635                 goto cleanup;
1636         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1637         if (!fpu)
1638                 goto cleanup;
1639 #ifdef ELF_CORE_COPY_XFPREGS
1640         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1641         if (!xfpu)
1642                 goto cleanup;
1643 #endif
1644
1645         if (signr) {
1646                 struct core_thread *ct;
1647                 struct elf_thread_status *tmp;
1648
1649                 for (ct = current->mm->core_state->dumper.next;
1650                                                 ct; ct = ct->next) {
1651                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1652                         if (!tmp)
1653                                 goto cleanup;
1654
1655                         tmp->thread = ct->task;
1656                         list_add(&tmp->list, &thread_list);
1657                 }
1658
1659                 list_for_each(t, &thread_list) {
1660                         struct elf_thread_status *tmp;
1661                         int sz;
1662
1663                         tmp = list_entry(t, struct elf_thread_status, list);
1664                         sz = elf_dump_thread_status(signr, tmp);
1665                         thread_status_size += sz;
1666                 }
1667         }
1668
1669         /* now collect the dump for the current */
1670         fill_prstatus(prstatus, current, signr);
1671         elf_core_copy_regs(&prstatus->pr_reg, regs);
1672
1673         segs = current->mm->map_count;
1674 #ifdef ELF_CORE_EXTRA_PHDRS
1675         segs += ELF_CORE_EXTRA_PHDRS;
1676 #endif
1677
1678         /* Set up header */
1679         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1680
1681         has_dumped = 1;
1682         current->flags |= PF_DUMPCORE;
1683
1684         /*
1685          * Set up the notes in similar form to SVR4 core dumps made
1686          * with info from their /proc.
1687          */
1688
1689         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1690         fill_psinfo(psinfo, current->group_leader, current->mm);
1691         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1692
1693         numnote = 2;
1694
1695         auxv = (elf_addr_t *) current->mm->saved_auxv;
1696
1697         i = 0;
1698         do
1699                 i += 2;
1700         while (auxv[i - 2] != AT_NULL);
1701         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1702                   i * sizeof(elf_addr_t), auxv);
1703
1704         /* Try to dump the FPU. */
1705         if ((prstatus->pr_fpvalid =
1706              elf_core_copy_task_fpregs(current, regs, fpu)))
1707                 fill_note(notes + numnote++,
1708                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1709 #ifdef ELF_CORE_COPY_XFPREGS
1710         if (elf_core_copy_task_xfpregs(current, xfpu))
1711                 fill_note(notes + numnote++,
1712                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1713 #endif
1714
1715         fs = get_fs();
1716         set_fs(KERNEL_DS);
1717
1718         DUMP_WRITE(elf, sizeof(*elf));
1719         offset += sizeof(*elf);                         /* Elf header */
1720         offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1721
1722         /* Write notes phdr entry */
1723         {
1724                 struct elf_phdr phdr;
1725                 int sz = 0;
1726
1727                 for (i = 0; i < numnote; i++)
1728                         sz += notesize(notes + i);
1729
1730                 sz += thread_status_size;
1731
1732                 fill_elf_note_phdr(&phdr, sz, offset);
1733                 offset += sz;
1734                 DUMP_WRITE(&phdr, sizeof(phdr));
1735         }
1736
1737         /* Page-align dumped data */
1738         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1739
1740         /*
1741          * We must use the same mm->flags while dumping core to avoid
1742          * inconsistency between the program headers and bodies, otherwise an
1743          * unusable core file can be generated.
1744          */
1745         mm_flags = current->mm->flags;
1746
1747         /* write program headers for segments dump */
1748         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1749                 struct elf_phdr phdr;
1750                 size_t sz;
1751
1752                 sz = vma->vm_end - vma->vm_start;
1753
1754                 phdr.p_type = PT_LOAD;
1755                 phdr.p_offset = offset;
1756                 phdr.p_vaddr = vma->vm_start;
1757                 phdr.p_paddr = 0;
1758                 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1759                 phdr.p_memsz = sz;
1760                 offset += phdr.p_filesz;
1761                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1762                 if (vma->vm_flags & VM_WRITE)
1763                         phdr.p_flags |= PF_W;
1764                 if (vma->vm_flags & VM_EXEC)
1765                         phdr.p_flags |= PF_X;
1766                 phdr.p_align = ELF_EXEC_PAGESIZE;
1767
1768                 DUMP_WRITE(&phdr, sizeof(phdr));
1769         }
1770
1771 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1772         ELF_CORE_WRITE_EXTRA_PHDRS;
1773 #endif
1774
1775         /* write out the notes section */
1776         for (i = 0; i < numnote; i++)
1777                 if (!writenote(notes + i, file))
1778                         goto end_coredump;
1779
1780         /* write out the thread status notes section */
1781         list_for_each(t, &thread_list) {
1782                 struct elf_thread_status *tmp =
1783                                 list_entry(t, struct elf_thread_status, list);
1784
1785                 for (i = 0; i < tmp->num_notes; i++)
1786                         if (!writenote(&tmp->notes[i], file))
1787                                 goto end_coredump;
1788         }
1789
1790         if (!dump_seek(file, dataoff))
1791                 goto end_coredump;
1792
1793         if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1794                 goto end_coredump;
1795
1796 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1797         ELF_CORE_WRITE_EXTRA_DATA;
1798 #endif
1799
1800         if (file->f_pos != offset) {
1801                 /* Sanity check */
1802                 printk(KERN_WARNING
1803                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1804                        file->f_pos, offset);
1805         }
1806
1807 end_coredump:
1808         set_fs(fs);
1809
1810 cleanup:
1811         while (!list_empty(&thread_list)) {
1812                 struct list_head *tmp = thread_list.next;
1813                 list_del(tmp);
1814                 kfree(list_entry(tmp, struct elf_thread_status, list));
1815         }
1816
1817         kfree(elf);
1818         kfree(prstatus);
1819         kfree(psinfo);
1820         kfree(notes);
1821         kfree(fpu);
1822 #ifdef ELF_CORE_COPY_XFPREGS
1823         kfree(xfpu);
1824 #endif
1825         return has_dumped;
1826 #undef NUM_NOTES
1827 }
1828
1829 #endif          /* USE_ELF_CORE_DUMP */