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