git.oblomov.eu Git - linux-2.6/blob - fs/binfmt_elf_fdpic.c

   1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
   2  *
   3  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  * Derived from binfmt_elf.c
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14
  15 #include <linux/fs.h>
  16 #include <linux/stat.h>
  17 #include <linux/sched.h>
  18 #include <linux/mm.h>
  19 #include <linux/mman.h>
  20 #include <linux/errno.h>
  21 #include <linux/signal.h>
  22 #include <linux/binfmts.h>
  23 #include <linux/string.h>
  24 #include <linux/file.h>
  25 #include <linux/fcntl.h>
  26 #include <linux/slab.h>
  27 #include <linux/pagemap.h>
  28 #include <linux/highmem.h>
  29 #include <linux/highuid.h>
  30 #include <linux/personality.h>
  31 #include <linux/ptrace.h>
  32 #include <linux/init.h>
  33 #include <linux/elf.h>
  34 #include <linux/elf-fdpic.h>
  35 #include <linux/elfcore.h>
  36
  37 #include <asm/uaccess.h>
  38 #include <asm/param.h>
  39 #include <asm/pgalloc.h>
  40
  41 typedef char *elf_caddr_t;
  42
  43 #if 0
  44 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  45 #else
  46 #define kdebug(fmt, ...) do {} while(0)
  47 #endif
  48
  49 #if 0
  50 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  51 #else
  52 #define kdcore(fmt, ...) do {} while(0)
  53 #endif
  54
  55 MODULE_LICENSE("GPL");
  56
  57 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
  58 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  59 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  60                               struct mm_struct *, const char *);
  61
  62 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  63                                    struct elf_fdpic_params *,
  64                                    struct elf_fdpic_params *);
  65
  66 #ifndef CONFIG_MMU
  67 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
  68                                             unsigned long *);
  69 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  70                                                    struct file *,
  71                                                    struct mm_struct *);
  72 #endif
  73
  74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  75                                              struct file *, struct mm_struct *);
  76
  77 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  78 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit);
  79 #endif
  80
  81 static struct linux_binfmt elf_fdpic_format = {
  82         .module         = THIS_MODULE,
  83         .load_binary    = load_elf_fdpic_binary,
  84 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  85         .core_dump      = elf_fdpic_core_dump,
  86 #endif
  87         .min_coredump   = ELF_EXEC_PAGESIZE,
  88 };
  89
  90 static int __init init_elf_fdpic_binfmt(void)
  91 {
  92         return register_binfmt(&elf_fdpic_format);
  93 }
  94
  95 static void __exit exit_elf_fdpic_binfmt(void)
  96 {
  97         unregister_binfmt(&elf_fdpic_format);
  98 }
  99
 100 core_initcall(init_elf_fdpic_binfmt);
 101 module_exit(exit_elf_fdpic_binfmt);
 102
 103 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
 104 {
 105         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 106                 return 0;
 107         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 108                 return 0;
 109         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
 110                 return 0;
 111         if (!file->f_op || !file->f_op->mmap)
 112                 return 0;
 113         return 1;
 114 }
 115
 116 /*****************************************************************************/
 117 /*
 118  * read the program headers table into memory
 119  */
 120 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 121                                  struct file *file)
 122 {
 123         struct elf32_phdr *phdr;
 124         unsigned long size;
 125         int retval, loop;
 126
 127         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 128                 return -ENOMEM;
 129         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 130                 return -ENOMEM;
 131
 132         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 133         params->phdrs = kmalloc(size, GFP_KERNEL);
 134         if (!params->phdrs)
 135                 return -ENOMEM;
 136
 137         retval = kernel_read(file, params->hdr.e_phoff,
 138                              (char *) params->phdrs, size);
 139         if (retval < 0)
 140                 return retval;
 141
 142         /* determine stack size for this binary */
 143         phdr = params->phdrs;
 144         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 145                 if (phdr->p_type != PT_GNU_STACK)
 146                         continue;
 147
 148                 if (phdr->p_flags & PF_X)
 149                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 150                 else
 151                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 152
 153                 params->stack_size = phdr->p_memsz;
 154                 break;
 155         }
 156
 157         return 0;
 158 }
 159
 160 /*****************************************************************************/
 161 /*
 162  * load an fdpic binary into various bits of memory
 163  */
 164 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
 165                                  struct pt_regs *regs)
 166 {
 167         struct elf_fdpic_params exec_params, interp_params;
 168         struct elf_phdr *phdr;
 169         unsigned long stack_size, entryaddr;
 170 #ifndef CONFIG_MMU
 171         unsigned long fullsize;
 172 #endif
 173 #ifdef ELF_FDPIC_PLAT_INIT
 174         unsigned long dynaddr;
 175 #endif
 176         struct file *interpreter = NULL; /* to shut gcc up */
 177         char *interpreter_name = NULL;
 178         int executable_stack;
 179         int retval, i;
 180
 181         kdebug("____ LOAD %d ____", current->pid);
 182
 183         memset(&exec_params, 0, sizeof(exec_params));
 184         memset(&interp_params, 0, sizeof(interp_params));
 185
 186         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 187         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 188
 189         /* check that this is a binary we know how to deal with */
 190         retval = -ENOEXEC;
 191         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
 192                 goto error;
 193
 194         /* read the program header table */
 195         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 196         if (retval < 0)
 197                 goto error;
 198
 199         /* scan for a program header that specifies an interpreter */
 200         phdr = exec_params.phdrs;
 201
 202         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 203                 switch (phdr->p_type) {
 204                 case PT_INTERP:
 205                         retval = -ENOMEM;
 206                         if (phdr->p_filesz > PATH_MAX)
 207                                 goto error;
 208                         retval = -ENOENT;
 209                         if (phdr->p_filesz < 2)
 210                                 goto error;
 211
 212                         /* read the name of the interpreter into memory */
 213                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 214                         if (!interpreter_name)
 215                                 goto error;
 216
 217                         retval = kernel_read(bprm->file,
 218                                              phdr->p_offset,
 219                                              interpreter_name,
 220                                              phdr->p_filesz);
 221                         if (retval < 0)
 222                                 goto error;
 223
 224                         retval = -ENOENT;
 225                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 226                                 goto error;
 227
 228                         kdebug("Using ELF interpreter %s", interpreter_name);
 229
 230                         /* replace the program with the interpreter */
 231                         interpreter = open_exec(interpreter_name);
 232                         retval = PTR_ERR(interpreter);
 233                         if (IS_ERR(interpreter)) {
 234                                 interpreter = NULL;
 235                                 goto error;
 236                         }
 237
 238                         /*
 239                          * If the binary is not readable then enforce
 240                          * mm->dumpable = 0 regardless of the interpreter's
 241                          * permissions.
 242                          */
 243                         if (file_permission(interpreter, MAY_READ) < 0)
 244                                 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
 245
 246                         retval = kernel_read(interpreter, 0, bprm->buf,
 247                                              BINPRM_BUF_SIZE);
 248                         if (retval < 0)
 249                                 goto error;
 250
 251                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 252                         break;
 253
 254                 case PT_LOAD:
 255 #ifdef CONFIG_MMU
 256                         if (exec_params.load_addr == 0)
 257                                 exec_params.load_addr = phdr->p_vaddr;
 258 #endif
 259                         break;
 260                 }
 261
 262         }
 263
 264         if (elf_check_const_displacement(&exec_params.hdr))
 265                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 266
 267         /* perform insanity checks on the interpreter */
 268         if (interpreter_name) {
 269                 retval = -ELIBBAD;
 270                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
 271                         goto error;
 272
 273                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 274
 275                 /* read the interpreter's program header table */
 276                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 277                 if (retval < 0)
 278                         goto error;
 279         }
 280
 281         stack_size = exec_params.stack_size;
 282         if (stack_size < interp_params.stack_size)
 283                 stack_size = interp_params.stack_size;
 284
 285         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 286                 executable_stack = EXSTACK_ENABLE_X;
 287         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 288                 executable_stack = EXSTACK_DISABLE_X;
 289         else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 290                 executable_stack = EXSTACK_ENABLE_X;
 291         else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 292                 executable_stack = EXSTACK_DISABLE_X;
 293         else
 294                 executable_stack = EXSTACK_DEFAULT;
 295
 296         retval = -ENOEXEC;
 297         if (stack_size == 0)
 298                 goto error;
 299
 300         if (elf_check_const_displacement(&interp_params.hdr))
 301                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 302
 303         /* flush all traces of the currently running executable */
 304         retval = flush_old_exec(bprm);
 305         if (retval)
 306                 goto error;
 307
 308         /* there's now no turning back... the old userspace image is dead,
 309          * defunct, deceased, etc. after this point we have to exit via
 310          * error_kill */
 311         set_personality(PER_LINUX_FDPIC);
 312         set_binfmt(&elf_fdpic_format);
 313
 314         current->mm->start_code = 0;
 315         current->mm->end_code = 0;
 316         current->mm->start_stack = 0;
 317         current->mm->start_data = 0;
 318         current->mm->end_data = 0;
 319         current->mm->context.exec_fdpic_loadmap = 0;
 320         current->mm->context.interp_fdpic_loadmap = 0;
 321
 322         current->flags &= ~PF_FORKNOEXEC;
 323
 324 #ifdef CONFIG_MMU
 325         elf_fdpic_arch_lay_out_mm(&exec_params,
 326                                   &interp_params,
 327                                   &current->mm->start_stack,
 328                                   &current->mm->start_brk);
 329
 330         retval = setup_arg_pages(bprm, current->mm->start_stack,
 331                                  executable_stack);
 332         if (retval < 0) {
 333                 send_sig(SIGKILL, current, 0);
 334                 goto error_kill;
 335         }
 336 #endif
 337
 338         /* load the executable and interpreter into memory */
 339         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 340                                     "executable");
 341         if (retval < 0)
 342                 goto error_kill;
 343
 344         if (interpreter_name) {
 345                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 346                                             current->mm, "interpreter");
 347                 if (retval < 0) {
 348                         printk(KERN_ERR "Unable to load interpreter\n");
 349                         goto error_kill;
 350                 }
 351
 352                 allow_write_access(interpreter);
 353                 fput(interpreter);
 354                 interpreter = NULL;
 355         }
 356
 357 #ifdef CONFIG_MMU
 358         if (!current->mm->start_brk)
 359                 current->mm->start_brk = current->mm->end_data;
 360
 361         current->mm->brk = current->mm->start_brk =
 362                 PAGE_ALIGN(current->mm->start_brk);
 363
 364 #else
 365         /* create a stack and brk area big enough for everyone
 366          * - the brk heap starts at the bottom and works up
 367          * - the stack starts at the top and works down
 368          */
 369         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 370         if (stack_size < PAGE_SIZE * 2)
 371                 stack_size = PAGE_SIZE * 2;
 372
 373         down_write(&current->mm->mmap_sem);
 374         current->mm->start_brk = do_mmap(NULL, 0, stack_size,
 375                                          PROT_READ | PROT_WRITE | PROT_EXEC,
 376                                          MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
 377                                          0);
 378
 379         if (IS_ERR_VALUE(current->mm->start_brk)) {
 380                 up_write(&current->mm->mmap_sem);
 381                 retval = current->mm->start_brk;
 382                 current->mm->start_brk = 0;
 383                 goto error_kill;
 384         }
 385
 386         /* expand the stack mapping to use up the entire allocation granule */
 387         fullsize = ksize((char *) current->mm->start_brk);
 388         if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
 389                                     fullsize, 0, 0)))
 390                 stack_size = fullsize;
 391         up_write(&current->mm->mmap_sem);
 392
 393         current->mm->brk = current->mm->start_brk;
 394         current->mm->context.end_brk = current->mm->start_brk;
 395         current->mm->context.end_brk +=
 396                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 397         current->mm->start_stack = current->mm->start_brk + stack_size;
 398 #endif
 399
 400         compute_creds(bprm);
 401         current->flags &= ~PF_FORKNOEXEC;
 402         if (create_elf_fdpic_tables(bprm, current->mm,
 403                                     &exec_params, &interp_params) < 0)
 404                 goto error_kill;
 405
 406         kdebug("- start_code  %lx", current->mm->start_code);
 407         kdebug("- end_code    %lx", current->mm->end_code);
 408         kdebug("- start_data  %lx", current->mm->start_data);
 409         kdebug("- end_data    %lx", current->mm->end_data);
 410         kdebug("- start_brk   %lx", current->mm->start_brk);
 411         kdebug("- brk         %lx", current->mm->brk);
 412         kdebug("- start_stack %lx", current->mm->start_stack);
 413
 414 #ifdef ELF_FDPIC_PLAT_INIT
 415         /*
 416          * The ABI may specify that certain registers be set up in special
 417          * ways (on i386 %edx is the address of a DT_FINI function, for
 418          * example.  This macro performs whatever initialization to
 419          * the regs structure is required.
 420          */
 421         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 422         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 423                             dynaddr);
 424 #endif
 425
 426         /* everything is now ready... get the userspace context ready to roll */
 427         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 428         start_thread(regs, entryaddr, current->mm->start_stack);
 429
 430         if (unlikely(current->ptrace & PT_PTRACED)) {
 431                 if (current->ptrace & PT_TRACE_EXEC)
 432                         ptrace_notify((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
 433                 else
 434                         send_sig(SIGTRAP, current, 0);
 435         }
 436
 437         retval = 0;
 438
 439 error:
 440         if (interpreter) {
 441                 allow_write_access(interpreter);
 442                 fput(interpreter);
 443         }
 444         kfree(interpreter_name);
 445         kfree(exec_params.phdrs);
 446         kfree(exec_params.loadmap);
 447         kfree(interp_params.phdrs);
 448         kfree(interp_params.loadmap);
 449         return retval;
 450
 451         /* unrecoverable error - kill the process */
 452 error_kill:
 453         send_sig(SIGSEGV, current, 0);
 454         goto error;
 455
 456 }
 457
 458 /*****************************************************************************/
 459 /*
 460  * present useful information to the program
 461  */
 462 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 463                                    struct mm_struct *mm,
 464                                    struct elf_fdpic_params *exec_params,
 465                                    struct elf_fdpic_params *interp_params)
 466 {
 467         unsigned long sp, csp, nitems;
 468         elf_caddr_t __user *argv, *envp;
 469         size_t platform_len = 0, len;
 470         char *k_platform;
 471         char __user *u_platform, *p;
 472         long hwcap;
 473         int loop;
 474
 475         /* we're going to shovel a whole load of stuff onto the stack */
 476 #ifdef CONFIG_MMU
 477         sp = bprm->p;
 478 #else
 479         sp = mm->start_stack;
 480
 481         /* stack the program arguments and environment */
 482         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 483                 return -EFAULT;
 484 #endif
 485
 486         /* get hold of platform and hardware capabilities masks for the machine
 487          * we are running on.  In some cases (Sparc), this info is impossible
 488          * to get, in others (i386) it is merely difficult.
 489          */
 490         hwcap = ELF_HWCAP;
 491         k_platform = ELF_PLATFORM;
 492         u_platform = NULL;
 493
 494         if (k_platform) {
 495                 platform_len = strlen(k_platform) + 1;
 496                 sp -= platform_len;
 497                 u_platform = (char __user *) sp;
 498                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 499                         return -EFAULT;
 500         }
 501
 502 #if defined(__i386__) && defined(CONFIG_SMP)
 503         /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 504          * by the processes running on the same package. One thing we can do is
 505          * to shuffle the initial stack for them.
 506          *
 507          * the conditionals here are unneeded, but kept in to make the code
 508          * behaviour the same as pre change unless we have hyperthreaded
 509          * processors. This keeps Mr Marcelo Person happier but should be
 510          * removed for 2.5
 511          */
 512         if (smp_num_siblings > 1)
 513                 sp = sp - ((current->pid % 64) << 7);
 514 #endif
 515
 516         sp &= ~7UL;
 517
 518         /* stack the load map(s) */
 519         len = sizeof(struct elf32_fdpic_loadmap);
 520         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 521         sp = (sp - len) & ~7UL;
 522         exec_params->map_addr = sp;
 523
 524         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 525                 return -EFAULT;
 526
 527         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 528
 529         if (interp_params->loadmap) {
 530                 len = sizeof(struct elf32_fdpic_loadmap);
 531                 len += sizeof(struct elf32_fdpic_loadseg) *
 532                         interp_params->loadmap->nsegs;
 533                 sp = (sp - len) & ~7UL;
 534                 interp_params->map_addr = sp;
 535
 536                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 537                                  len) != 0)
 538                         return -EFAULT;
 539
 540                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 541         }
 542
 543         /* force 16 byte _final_ alignment here for generality */
 544 #define DLINFO_ITEMS 13
 545
 546         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
 547 #ifdef DLINFO_ARCH_ITEMS
 548         nitems += DLINFO_ARCH_ITEMS;
 549 #endif
 550
 551         csp = sp;
 552         sp -= nitems * 2 * sizeof(unsigned long);
 553         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 554         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 555         sp -= 1 * sizeof(unsigned long);                /* argc */
 556
 557         csp -= sp & 15UL;
 558         sp -= sp & 15UL;
 559
 560         /* put the ELF interpreter info on the stack */
 561 #define NEW_AUX_ENT(nr, id, val)                                        \
 562         do {                                                            \
 563                 struct { unsigned long _id, _val; } __user *ent;        \
 564                                                                         \
 565                 ent = (void __user *) csp;                              \
 566                 __put_user((id), &ent[nr]._id);                         \
 567                 __put_user((val), &ent[nr]._val);                       \
 568         } while (0)
 569
 570         csp -= 2 * sizeof(unsigned long);
 571         NEW_AUX_ENT(0, AT_NULL, 0);
 572         if (k_platform) {
 573                 csp -= 2 * sizeof(unsigned long);
 574                 NEW_AUX_ENT(0, AT_PLATFORM,
 575                             (elf_addr_t) (unsigned long) u_platform);
 576         }
 577
 578         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 579         NEW_AUX_ENT( 0, AT_HWCAP,       hwcap);
 580         NEW_AUX_ENT( 1, AT_PAGESZ,      PAGE_SIZE);
 581         NEW_AUX_ENT( 2, AT_CLKTCK,      CLOCKS_PER_SEC);
 582         NEW_AUX_ENT( 3, AT_PHDR,        exec_params->ph_addr);
 583         NEW_AUX_ENT( 4, AT_PHENT,       sizeof(struct elf_phdr));
 584         NEW_AUX_ENT( 5, AT_PHNUM,       exec_params->hdr.e_phnum);
 585         NEW_AUX_ENT( 6, AT_BASE,        interp_params->elfhdr_addr);
 586         NEW_AUX_ENT( 7, AT_FLAGS,       0);
 587         NEW_AUX_ENT( 8, AT_ENTRY,       exec_params->entry_addr);
 588         NEW_AUX_ENT( 9, AT_UID,         (elf_addr_t) current->uid);
 589         NEW_AUX_ENT(10, AT_EUID,        (elf_addr_t) current->euid);
 590         NEW_AUX_ENT(11, AT_GID,         (elf_addr_t) current->gid);
 591         NEW_AUX_ENT(12, AT_EGID,        (elf_addr_t) current->egid);
 592
 593 #ifdef ARCH_DLINFO
 594         /* ARCH_DLINFO must come last so platform specific code can enforce
 595          * special alignment requirements on the AUXV if necessary (eg. PPC).
 596          */
 597         ARCH_DLINFO;
 598 #endif
 599 #undef NEW_AUX_ENT
 600
 601         /* allocate room for argv[] and envv[] */
 602         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 603         envp = (elf_caddr_t __user *) csp;
 604         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 605         argv = (elf_caddr_t __user *) csp;
 606
 607         /* stack argc */
 608         csp -= sizeof(unsigned long);
 609         __put_user(bprm->argc, (unsigned long __user *) csp);
 610
 611         BUG_ON(csp != sp);
 612
 613         /* fill in the argv[] array */
 614 #ifdef CONFIG_MMU
 615         current->mm->arg_start = bprm->p;
 616 #else
 617         current->mm->arg_start = current->mm->start_stack -
 618                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 619 #endif
 620
 621         p = (char __user *) current->mm->arg_start;
 622         for (loop = bprm->argc; loop > 0; loop--) {
 623                 __put_user((elf_caddr_t) p, argv++);
 624                 len = strnlen_user(p, MAX_ARG_STRLEN);
 625                 if (!len || len > MAX_ARG_STRLEN)
 626                         return -EINVAL;
 627                 p += len;
 628         }
 629         __put_user(NULL, argv);
 630         current->mm->arg_end = (unsigned long) p;
 631
 632         /* fill in the envv[] array */
 633         current->mm->env_start = (unsigned long) p;
 634         for (loop = bprm->envc; loop > 0; loop--) {
 635                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 636                 len = strnlen_user(p, MAX_ARG_STRLEN);
 637                 if (!len || len > MAX_ARG_STRLEN)
 638                         return -EINVAL;
 639                 p += len;
 640         }
 641         __put_user(NULL, envp);
 642         current->mm->env_end = (unsigned long) p;
 643
 644         mm->start_stack = (unsigned long) sp;
 645         return 0;
 646 }
 647
 648 /*****************************************************************************/
 649 /*
 650  * transfer the program arguments and environment from the holding pages onto
 651  * the stack
 652  */
 653 #ifndef CONFIG_MMU
 654 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 655                                             unsigned long *_sp)
 656 {
 657         unsigned long index, stop, sp;
 658         char *src;
 659         int ret = 0;
 660
 661         stop = bprm->p >> PAGE_SHIFT;
 662         sp = *_sp;
 663
 664         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 665                 src = kmap(bprm->page[index]);
 666                 sp -= PAGE_SIZE;
 667                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 668                         ret = -EFAULT;
 669                 kunmap(bprm->page[index]);
 670                 if (ret < 0)
 671                         goto out;
 672         }
 673
 674         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 675
 676 out:
 677         return ret;
 678 }
 679 #endif
 680
 681 /*****************************************************************************/
 682 /*
 683  * load the appropriate binary image (executable or interpreter) into memory
 684  * - we assume no MMU is available
 685  * - if no other PIC bits are set in params->hdr->e_flags
 686  *   - we assume that the LOADable segments in the binary are independently relocatable
 687  *   - we assume R/O executable segments are shareable
 688  * - else
 689  *   - we assume the loadable parts of the image to require fixed displacement
 690  *   - the image is not shareable
 691  */
 692 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 693                               struct file *file,
 694                               struct mm_struct *mm,
 695                               const char *what)
 696 {
 697         struct elf32_fdpic_loadmap *loadmap;
 698 #ifdef CONFIG_MMU
 699         struct elf32_fdpic_loadseg *mseg;
 700 #endif
 701         struct elf32_fdpic_loadseg *seg;
 702         struct elf32_phdr *phdr;
 703         unsigned long load_addr, stop;
 704         unsigned nloads, tmp;
 705         size_t size;
 706         int loop, ret;
 707
 708         /* allocate a load map table */
 709         nloads = 0;
 710         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 711                 if (params->phdrs[loop].p_type == PT_LOAD)
 712                         nloads++;
 713
 714         if (nloads == 0)
 715                 return -ELIBBAD;
 716
 717         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 718         loadmap = kzalloc(size, GFP_KERNEL);
 719         if (!loadmap)
 720                 return -ENOMEM;
 721
 722         params->loadmap = loadmap;
 723
 724         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 725         loadmap->nsegs = nloads;
 726
 727         load_addr = params->load_addr;
 728         seg = loadmap->segs;
 729
 730         /* map the requested LOADs into the memory space */
 731         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 732         case ELF_FDPIC_FLAG_CONSTDISP:
 733         case ELF_FDPIC_FLAG_CONTIGUOUS:
 734 #ifndef CONFIG_MMU
 735                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 736                 if (ret < 0)
 737                         return ret;
 738                 break;
 739 #endif
 740         default:
 741                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 742                 if (ret < 0)
 743                         return ret;
 744                 break;
 745         }
 746
 747         /* map the entry point */
 748         if (params->hdr.e_entry) {
 749                 seg = loadmap->segs;
 750                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 751                         if (params->hdr.e_entry >= seg->p_vaddr &&
 752                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 753                                 params->entry_addr =
 754                                         (params->hdr.e_entry - seg->p_vaddr) +
 755                                         seg->addr;
 756                                 break;
 757                         }
 758                 }
 759         }
 760
 761         /* determine where the program header table has wound up if mapped */
 762         stop = params->hdr.e_phoff;
 763         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 764         phdr = params->phdrs;
 765
 766         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 767                 if (phdr->p_type != PT_LOAD)
 768                         continue;
 769
 770                 if (phdr->p_offset > params->hdr.e_phoff ||
 771                     phdr->p_offset + phdr->p_filesz < stop)
 772                         continue;
 773
 774                 seg = loadmap->segs;
 775                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 776                         if (phdr->p_vaddr >= seg->p_vaddr &&
 777                             phdr->p_vaddr + phdr->p_filesz <=
 778                             seg->p_vaddr + seg->p_memsz) {
 779                                 params->ph_addr =
 780                                         (phdr->p_vaddr - seg->p_vaddr) +
 781                                         seg->addr +
 782                                         params->hdr.e_phoff - phdr->p_offset;
 783                                 break;
 784                         }
 785                 }
 786                 break;
 787         }
 788
 789         /* determine where the dynamic section has wound up if there is one */
 790         phdr = params->phdrs;
 791         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 792                 if (phdr->p_type != PT_DYNAMIC)
 793                         continue;
 794
 795                 seg = loadmap->segs;
 796                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 797                         if (phdr->p_vaddr >= seg->p_vaddr &&
 798                             phdr->p_vaddr + phdr->p_memsz <=
 799                             seg->p_vaddr + seg->p_memsz) {
 800                                 params->dynamic_addr =
 801                                         (phdr->p_vaddr - seg->p_vaddr) +
 802                                         seg->addr;
 803
 804                                 /* check the dynamic section contains at least
 805                                  * one item, and that the last item is a NULL
 806                                  * entry */
 807                                 if (phdr->p_memsz == 0 ||
 808                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 809                                         goto dynamic_error;
 810
 811                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 812                                 if (((Elf32_Dyn *)
 813                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
 814                                         goto dynamic_error;
 815                                 break;
 816                         }
 817                 }
 818                 break;
 819         }
 820
 821         /* now elide adjacent segments in the load map on MMU linux
 822          * - on uClinux the holes between may actually be filled with system
 823          *   stuff or stuff from other processes
 824          */
 825 #ifdef CONFIG_MMU
 826         nloads = loadmap->nsegs;
 827         mseg = loadmap->segs;
 828         seg = mseg + 1;
 829         for (loop = 1; loop < nloads; loop++) {
 830                 /* see if we have a candidate for merging */
 831                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 832                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 833                         if (load_addr == (seg->addr & PAGE_MASK)) {
 834                                 mseg->p_memsz +=
 835                                         load_addr -
 836                                         (mseg->addr + mseg->p_memsz);
 837                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 838                                 mseg->p_memsz += seg->p_memsz;
 839                                 loadmap->nsegs--;
 840                                 continue;
 841                         }
 842                 }
 843
 844                 mseg++;
 845                 if (mseg != seg)
 846                         *mseg = *seg;
 847         }
 848 #endif
 849
 850         kdebug("Mapped Object [%s]:", what);
 851         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 852         kdebug("- entry    : %lx", params->entry_addr);
 853         kdebug("- PHDR[]   : %lx", params->ph_addr);
 854         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 855         seg = loadmap->segs;
 856         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 857                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 858                        loop,
 859                        seg->addr, seg->addr + seg->p_memsz - 1,
 860                        seg->p_vaddr, seg->p_memsz);
 861
 862         return 0;
 863
 864 dynamic_error:
 865         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 866                what, file->f_path.dentry->d_inode->i_ino);
 867         return -ELIBBAD;
 868 }
 869
 870 /*****************************************************************************/
 871 /*
 872  * map a file with constant displacement under uClinux
 873  */
 874 #ifndef CONFIG_MMU
 875 static int elf_fdpic_map_file_constdisp_on_uclinux(
 876         struct elf_fdpic_params *params,
 877         struct file *file,
 878         struct mm_struct *mm)
 879 {
 880         struct elf32_fdpic_loadseg *seg;
 881         struct elf32_phdr *phdr;
 882         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 883         loff_t fpos;
 884         int loop, ret;
 885
 886         load_addr = params->load_addr;
 887         seg = params->loadmap->segs;
 888
 889         /* determine the bounds of the contiguous overall allocation we must
 890          * make */
 891         phdr = params->phdrs;
 892         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 893                 if (params->phdrs[loop].p_type != PT_LOAD)
 894                         continue;
 895
 896                 if (base > phdr->p_vaddr)
 897                         base = phdr->p_vaddr;
 898                 if (top < phdr->p_vaddr + phdr->p_memsz)
 899                         top = phdr->p_vaddr + phdr->p_memsz;
 900         }
 901
 902         /* allocate one big anon block for everything */
 903         mflags = MAP_PRIVATE;
 904         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 905                 mflags |= MAP_EXECUTABLE;
 906
 907         down_write(&mm->mmap_sem);
 908         maddr = do_mmap(NULL, load_addr, top - base,
 909                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 910         up_write(&mm->mmap_sem);
 911         if (IS_ERR_VALUE(maddr))
 912                 return (int) maddr;
 913
 914         if (load_addr != 0)
 915                 load_addr += PAGE_ALIGN(top - base);
 916
 917         /* and then load the file segments into it */
 918         phdr = params->phdrs;
 919         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 920                 if (params->phdrs[loop].p_type != PT_LOAD)
 921                         continue;
 922
 923                 fpos = phdr->p_offset;
 924
 925                 seg->addr = maddr + (phdr->p_vaddr - base);
 926                 seg->p_vaddr = phdr->p_vaddr;
 927                 seg->p_memsz = phdr->p_memsz;
 928
 929                 ret = file->f_op->read(file, (void *) seg->addr,
 930                                        phdr->p_filesz, &fpos);
 931                 if (ret < 0)
 932                         return ret;
 933
 934                 /* map the ELF header address if in this segment */
 935                 if (phdr->p_offset == 0)
 936                         params->elfhdr_addr = seg->addr;
 937
 938                 /* clear any space allocated but not loaded */
 939                 if (phdr->p_filesz < phdr->p_memsz)
 940                         clear_user((void *) (seg->addr + phdr->p_filesz),
 941                                    phdr->p_memsz - phdr->p_filesz);
 942
 943                 if (mm) {
 944                         if (phdr->p_flags & PF_X) {
 945                                 if (!mm->start_code) {
 946                                         mm->start_code = seg->addr;
 947                                         mm->end_code = seg->addr +
 948                                                 phdr->p_memsz;
 949                                 }
 950                         } else if (!mm->start_data) {
 951                                 mm->start_data = seg->addr;
 952 #ifndef CONFIG_MMU
 953                                 mm->end_data = seg->addr + phdr->p_memsz;
 954 #endif
 955                         }
 956
 957 #ifdef CONFIG_MMU
 958                         if (seg->addr + phdr->p_memsz > mm->end_data)
 959                                 mm->end_data = seg->addr + phdr->p_memsz;
 960 #endif
 961                 }
 962
 963                 seg++;
 964         }
 965
 966         return 0;
 967 }
 968 #endif
 969
 970 /*****************************************************************************/
 971 /*
 972  * map a binary by direct mmap() of the individual PT_LOAD segments
 973  */
 974 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
 975                                              struct file *file,
 976                                              struct mm_struct *mm)
 977 {
 978         struct elf32_fdpic_loadseg *seg;
 979         struct elf32_phdr *phdr;
 980         unsigned long load_addr, delta_vaddr;
 981         int loop, dvset;
 982
 983         load_addr = params->load_addr;
 984         delta_vaddr = 0;
 985         dvset = 0;
 986
 987         seg = params->loadmap->segs;
 988
 989         /* deal with each load segment separately */
 990         phdr = params->phdrs;
 991         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 992                 unsigned long maddr, disp, excess, excess1;
 993                 int prot = 0, flags;
 994
 995                 if (phdr->p_type != PT_LOAD)
 996                         continue;
 997
 998                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
 999                        (unsigned long) phdr->p_vaddr,
1000                        (unsigned long) phdr->p_offset,
1001                        (unsigned long) phdr->p_filesz,
1002                        (unsigned long) phdr->p_memsz);
1003
1004                 /* determine the mapping parameters */
1005                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1006                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1007                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1008
1009                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1010                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1011                         flags |= MAP_EXECUTABLE;
1012
1013                 maddr = 0;
1014
1015                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1016                 case ELF_FDPIC_FLAG_INDEPENDENT:
1017                         /* PT_LOADs are independently locatable */
1018                         break;
1019
1020                 case ELF_FDPIC_FLAG_HONOURVADDR:
1021                         /* the specified virtual address must be honoured */
1022                         maddr = phdr->p_vaddr;
1023                         flags |= MAP_FIXED;
1024                         break;
1025
1026                 case ELF_FDPIC_FLAG_CONSTDISP:
1027                         /* constant displacement
1028                          * - can be mapped anywhere, but must be mapped as a
1029                          *   unit
1030                          */
1031                         if (!dvset) {
1032                                 maddr = load_addr;
1033                                 delta_vaddr = phdr->p_vaddr;
1034                                 dvset = 1;
1035                         } else {
1036                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1037                                 flags |= MAP_FIXED;
1038                         }
1039                         break;
1040
1041                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1042                         /* contiguity handled later */
1043                         break;
1044
1045                 default:
1046                         BUG();
1047                 }
1048
1049                 maddr &= PAGE_MASK;
1050
1051                 /* create the mapping */
1052                 disp = phdr->p_vaddr & ~PAGE_MASK;
1053                 down_write(&mm->mmap_sem);
1054                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1055                                 phdr->p_offset - disp);
1056                 up_write(&mm->mmap_sem);
1057
1058                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1059                        loop, phdr->p_memsz + disp, prot, flags,
1060                        phdr->p_offset - disp, maddr);
1061
1062                 if (IS_ERR_VALUE(maddr))
1063                         return (int) maddr;
1064
1065                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1066                     ELF_FDPIC_FLAG_CONTIGUOUS)
1067                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1068
1069                 seg->addr = maddr + disp;
1070                 seg->p_vaddr = phdr->p_vaddr;
1071                 seg->p_memsz = phdr->p_memsz;
1072
1073                 /* map the ELF header address if in this segment */
1074                 if (phdr->p_offset == 0)
1075                         params->elfhdr_addr = seg->addr;
1076
1077                 /* clear the bit between beginning of mapping and beginning of
1078                  * PT_LOAD */
1079                 if (prot & PROT_WRITE && disp > 0) {
1080                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1081                         clear_user((void __user *) maddr, disp);
1082                         maddr += disp;
1083                 }
1084
1085                 /* clear any space allocated but not loaded
1086                  * - on uClinux we can just clear the lot
1087                  * - on MMU linux we'll get a SIGBUS beyond the last page
1088                  *   extant in the file
1089                  */
1090                 excess = phdr->p_memsz - phdr->p_filesz;
1091                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1092
1093 #ifdef CONFIG_MMU
1094                 if (excess > excess1) {
1095                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1096                         unsigned long xmaddr;
1097
1098                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1099                         down_write(&mm->mmap_sem);
1100                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1101                                          prot, flags, 0);
1102                         up_write(&mm->mmap_sem);
1103
1104                         kdebug("mmap[%d] <anon>"
1105                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1106                                loop, xaddr, excess - excess1, prot, flags,
1107                                xmaddr);
1108
1109                         if (xmaddr != xaddr)
1110                                 return -ENOMEM;
1111                 }
1112
1113                 if (prot & PROT_WRITE && excess1 > 0) {
1114                         kdebug("clear[%d] ad=%lx sz=%lx",
1115                                loop, maddr + phdr->p_filesz, excess1);
1116                         clear_user((void __user *) maddr + phdr->p_filesz,
1117                                    excess1);
1118                 }
1119
1120 #else
1121                 if (excess > 0) {
1122                         kdebug("clear[%d] ad=%lx sz=%lx",
1123                                loop, maddr + phdr->p_filesz, excess);
1124                         clear_user((void *) maddr + phdr->p_filesz, excess);
1125                 }
1126 #endif
1127
1128                 if (mm) {
1129                         if (phdr->p_flags & PF_X) {
1130                                 if (!mm->start_code) {
1131                                         mm->start_code = maddr;
1132                                         mm->end_code = maddr + phdr->p_memsz;
1133                                 }
1134                         } else if (!mm->start_data) {
1135                                 mm->start_data = maddr;
1136                                 mm->end_data = maddr + phdr->p_memsz;
1137                         }
1138                 }
1139
1140                 seg++;
1141         }
1142
1143         return 0;
1144 }
1145
1146 /*****************************************************************************/
1147 /*
1148  * ELF-FDPIC core dumper
1149  *
1150  * Modelled on fs/exec.c:aout_core_dump()
1151  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1152  *
1153  * Modelled on fs/binfmt_elf.c core dumper
1154  */
1155 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1156
1157 /*
1158  * These are the only things you should do on a core-file: use only these
1159  * functions to write out all the necessary info.
1160  */
1161 static int dump_write(struct file *file, const void *addr, int nr)
1162 {
1163         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1164 }
1165
1166 static int dump_seek(struct file *file, loff_t off)
1167 {
1168         if (file->f_op->llseek) {
1169                 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1170                         return 0;
1171         } else {
1172                 file->f_pos = off;
1173         }
1174         return 1;
1175 }
1176
1177 /*
1178  * Decide whether a segment is worth dumping; default is yes to be
1179  * sure (missing info is worse than too much; etc).
1180  * Personally I'd include everything, and use the coredump limit...
1181  *
1182  * I think we should skip something. But I am not sure how. H.J.
1183  */
1184 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1185 {
1186         int dump_ok;
1187
1188         /* Do not dump I/O mapped devices or special mappings */
1189         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1190                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1191                 return 0;
1192         }
1193
1194         /* If we may not read the contents, don't allow us to dump
1195          * them either. "dump_write()" can't handle it anyway.
1196          */
1197         if (!(vma->vm_flags & VM_READ)) {
1198                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1199                 return 0;
1200         }
1201
1202         /* By default, dump shared memory if mapped from an anonymous file. */
1203         if (vma->vm_flags & VM_SHARED) {
1204                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1205                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1206                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1207                                vma->vm_flags, dump_ok ? "yes" : "no");
1208                         return dump_ok;
1209                 }
1210
1211                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1212                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1213                        vma->vm_flags, dump_ok ? "yes" : "no");
1214                 return dump_ok;
1215         }
1216
1217 #ifdef CONFIG_MMU
1218         /* By default, if it hasn't been written to, don't write it out */
1219         if (!vma->anon_vma) {
1220                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1221                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1222                        vma->vm_flags, dump_ok ? "yes" : "no");
1223                 return dump_ok;
1224         }
1225 #endif
1226
1227         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1228         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1229                dump_ok ? "yes" : "no");
1230         return dump_ok;
1231 }
1232
1233 /* An ELF note in memory */
1234 struct memelfnote
1235 {
1236         const char *name;
1237         int type;
1238         unsigned int datasz;
1239         void *data;
1240 };
1241
1242 static int notesize(struct memelfnote *en)
1243 {
1244         int sz;
1245
1246         sz = sizeof(struct elf_note);
1247         sz += roundup(strlen(en->name) + 1, 4);
1248         sz += roundup(en->datasz, 4);
1249
1250         return sz;
1251 }
1252
1253 /* #define DEBUG */
1254
1255 #define DUMP_WRITE(addr, nr)    \
1256         do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1257 #define DUMP_SEEK(off)  \
1258         do { if (!dump_seek(file, (off))) return 0; } while(0)
1259
1260 static int writenote(struct memelfnote *men, struct file *file)
1261 {
1262         struct elf_note en;
1263
1264         en.n_namesz = strlen(men->name) + 1;
1265         en.n_descsz = men->datasz;
1266         en.n_type = men->type;
1267
1268         DUMP_WRITE(&en, sizeof(en));
1269         DUMP_WRITE(men->name, en.n_namesz);
1270         /* XXX - cast from long long to long to avoid need for libgcc.a */
1271         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1272         DUMP_WRITE(men->data, men->datasz);
1273         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1274
1275         return 1;
1276 }
1277 #undef DUMP_WRITE
1278 #undef DUMP_SEEK
1279
1280 #define DUMP_WRITE(addr, nr)    \
1281         if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1282                 goto end_coredump;
1283 #define DUMP_SEEK(off)  \
1284         if (!dump_seek(file, (off))) \
1285                 goto end_coredump;
1286
1287 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1288 {
1289         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1290         elf->e_ident[EI_CLASS] = ELF_CLASS;
1291         elf->e_ident[EI_DATA] = ELF_DATA;
1292         elf->e_ident[EI_VERSION] = EV_CURRENT;
1293         elf->e_ident[EI_OSABI] = ELF_OSABI;
1294         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1295
1296         elf->e_type = ET_CORE;
1297         elf->e_machine = ELF_ARCH;
1298         elf->e_version = EV_CURRENT;
1299         elf->e_entry = 0;
1300         elf->e_phoff = sizeof(struct elfhdr);
1301         elf->e_shoff = 0;
1302         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1303         elf->e_ehsize = sizeof(struct elfhdr);
1304         elf->e_phentsize = sizeof(struct elf_phdr);
1305         elf->e_phnum = segs;
1306         elf->e_shentsize = 0;
1307         elf->e_shnum = 0;
1308         elf->e_shstrndx = 0;
1309         return;
1310 }
1311
1312 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1313 {
1314         phdr->p_type = PT_NOTE;
1315         phdr->p_offset = offset;
1316         phdr->p_vaddr = 0;
1317         phdr->p_paddr = 0;
1318         phdr->p_filesz = sz;
1319         phdr->p_memsz = 0;
1320         phdr->p_flags = 0;
1321         phdr->p_align = 0;
1322         return;
1323 }
1324
1325 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1326                 unsigned int sz, void *data)
1327 {
1328         note->name = name;
1329         note->type = type;
1330         note->datasz = sz;
1331         note->data = data;
1332         return;
1333 }
1334
1335 /*
1336  * fill up all the fields in prstatus from the given task struct, except
1337  * registers which need to be filled up seperately.
1338  */
1339 static void fill_prstatus(struct elf_prstatus *prstatus,
1340                           struct task_struct *p, long signr)
1341 {
1342         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1343         prstatus->pr_sigpend = p->pending.signal.sig[0];
1344         prstatus->pr_sighold = p->blocked.sig[0];
1345         prstatus->pr_pid = task_pid_vnr(p);
1346         prstatus->pr_ppid = task_pid_vnr(p->parent);
1347         prstatus->pr_pgrp = task_pgrp_vnr(p);
1348         prstatus->pr_sid = task_session_vnr(p);
1349         if (thread_group_leader(p)) {
1350                 /*
1351                  * This is the record for the group leader.  Add in the
1352                  * cumulative times of previous dead threads.  This total
1353                  * won't include the time of each live thread whose state
1354                  * is included in the core dump.  The final total reported
1355                  * to our parent process when it calls wait4 will include
1356                  * those sums as well as the little bit more time it takes
1357                  * this and each other thread to finish dying after the
1358                  * core dump synchronization phase.
1359                  */
1360                 cputime_to_timeval(cputime_add(p->utime, p->signal->utime),
1361                                    &prstatus->pr_utime);
1362                 cputime_to_timeval(cputime_add(p->stime, p->signal->stime),
1363                                    &prstatus->pr_stime);
1364         } else {
1365                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1366                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1367         }
1368         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1369         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1370
1371         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1372         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1373 }
1374
1375 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1376                        struct mm_struct *mm)
1377 {
1378         unsigned int i, len;
1379
1380         /* first copy the parameters from user space */
1381         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1382
1383         len = mm->arg_end - mm->arg_start;
1384         if (len >= ELF_PRARGSZ)
1385                 len = ELF_PRARGSZ - 1;
1386         if (copy_from_user(&psinfo->pr_psargs,
1387                            (const char __user *) mm->arg_start, len))
1388                 return -EFAULT;
1389         for (i = 0; i < len; i++)
1390                 if (psinfo->pr_psargs[i] == 0)
1391                         psinfo->pr_psargs[i] = ' ';
1392         psinfo->pr_psargs[len] = 0;
1393
1394         psinfo->pr_pid = task_pid_vnr(p);
1395         psinfo->pr_ppid = task_pid_vnr(p->parent);
1396         psinfo->pr_pgrp = task_pgrp_vnr(p);
1397         psinfo->pr_sid = task_session_vnr(p);
1398
1399         i = p->state ? ffz(~p->state) + 1 : 0;
1400         psinfo->pr_state = i;
1401         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1402         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1403         psinfo->pr_nice = task_nice(p);
1404         psinfo->pr_flag = p->flags;
1405         SET_UID(psinfo->pr_uid, p->uid);
1406         SET_GID(psinfo->pr_gid, p->gid);
1407         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1408
1409         return 0;
1410 }
1411
1412 /* Here is the structure in which status of each thread is captured. */
1413 struct elf_thread_status
1414 {
1415         struct list_head list;
1416         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1417         elf_fpregset_t fpu;             /* NT_PRFPREG */
1418         struct task_struct *thread;
1419 #ifdef ELF_CORE_COPY_XFPREGS
1420         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1421 #endif
1422         struct memelfnote notes[3];
1423         int num_notes;
1424 };
1425
1426 /*
1427  * In order to add the specific thread information for the elf file format,
1428  * we need to keep a linked list of every thread's pr_status and then create
1429  * a single section for them in the final core file.
1430  */
1431 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1432 {
1433         struct task_struct *p = t->thread;
1434         int sz = 0;
1435
1436         t->num_notes = 0;
1437
1438         fill_prstatus(&t->prstatus, p, signr);
1439         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1440
1441         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1442                   &t->prstatus);
1443         t->num_notes++;
1444         sz += notesize(&t->notes[0]);
1445
1446         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1447         if (t->prstatus.pr_fpvalid) {
1448                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1449                           &t->fpu);
1450                 t->num_notes++;
1451                 sz += notesize(&t->notes[1]);
1452         }
1453
1454 #ifdef ELF_CORE_COPY_XFPREGS
1455         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1456                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1457                           sizeof(t->xfpu), &t->xfpu);
1458                 t->num_notes++;
1459                 sz += notesize(&t->notes[2]);
1460         }
1461 #endif
1462         return sz;
1463 }
1464
1465 /*
1466  * dump the segments for an MMU process
1467  */
1468 #ifdef CONFIG_MMU
1469 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1470                            unsigned long *limit, unsigned long mm_flags)
1471 {
1472         struct vm_area_struct *vma;
1473
1474         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1475                 unsigned long addr;
1476
1477                 if (!maydump(vma, mm_flags))
1478                         continue;
1479
1480                 for (addr = vma->vm_start;
1481                      addr < vma->vm_end;
1482                      addr += PAGE_SIZE
1483                      ) {
1484                         struct vm_area_struct *vma;
1485                         struct page *page;
1486
1487                         if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1488                                            &page, &vma) <= 0) {
1489                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1490                         }
1491                         else if (page == ZERO_PAGE(0)) {
1492                                 page_cache_release(page);
1493                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1494                         }
1495                         else {
1496                                 void *kaddr;
1497
1498                                 flush_cache_page(vma, addr, page_to_pfn(page));
1499                                 kaddr = kmap(page);
1500                                 if ((*size += PAGE_SIZE) > *limit ||
1501                                     !dump_write(file, kaddr, PAGE_SIZE)
1502                                     ) {
1503                                         kunmap(page);
1504                                         page_cache_release(page);
1505                                         return -EIO;
1506                                 }
1507                                 kunmap(page);
1508                                 page_cache_release(page);
1509                         }
1510                 }
1511         }
1512
1513         return 0;
1514
1515 end_coredump:
1516         return -EFBIG;
1517 }
1518 #endif
1519
1520 /*
1521  * dump the segments for a NOMMU process
1522  */
1523 #ifndef CONFIG_MMU
1524 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1525                            unsigned long *limit, unsigned long mm_flags)
1526 {
1527         struct vm_list_struct *vml;
1528
1529         for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1530         struct vm_area_struct *vma = vml->vma;
1531
1532                 if (!maydump(vma, mm_flags))
1533                         continue;
1534
1535                 if ((*size += PAGE_SIZE) > *limit)
1536                         return -EFBIG;
1537
1538                 if (!dump_write(file, (void *) vma->vm_start,
1539                                 vma->vm_end - vma->vm_start))
1540                         return -EIO;
1541         }
1542
1543         return 0;
1544 }
1545 #endif
1546
1547 /*
1548  * Actual dumper
1549  *
1550  * This is a two-pass process; first we find the offsets of the bits,
1551  * and then they are actually written out.  If we run out of core limit
1552  * we just truncate.
1553  */
1554 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1555                                struct file *file, unsigned long limit)
1556 {
1557 #define NUM_NOTES       6
1558         int has_dumped = 0;
1559         mm_segment_t fs;
1560         int segs;
1561         size_t size = 0;
1562         int i;
1563         struct vm_area_struct *vma;
1564         struct elfhdr *elf = NULL;
1565         loff_t offset = 0, dataoff;
1566         int numnote;
1567         struct memelfnote *notes = NULL;
1568         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1569         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1570         struct task_struct *g, *p;
1571         LIST_HEAD(thread_list);
1572         struct list_head *t;
1573         elf_fpregset_t *fpu = NULL;
1574 #ifdef ELF_CORE_COPY_XFPREGS
1575         elf_fpxregset_t *xfpu = NULL;
1576 #endif
1577         int thread_status_size = 0;
1578 #ifndef CONFIG_MMU
1579         struct vm_list_struct *vml;
1580 #endif
1581         elf_addr_t *auxv;
1582         unsigned long mm_flags;
1583
1584         /*
1585          * We no longer stop all VM operations.
1586          *
1587          * This is because those proceses that could possibly change map_count
1588          * or the mmap / vma pages are now blocked in do_exit on current
1589          * finishing this core dump.
1590          *
1591          * Only ptrace can touch these memory addresses, but it doesn't change
1592          * the map_count or the pages allocated. So no possibility of crashing
1593          * exists while dumping the mm->vm_next areas to the core file.
1594          */
1595
1596         /* alloc memory for large data structures: too large to be on stack */
1597         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1598         if (!elf)
1599                 goto cleanup;
1600         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1601         if (!prstatus)
1602                 goto cleanup;
1603         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1604         if (!psinfo)
1605                 goto cleanup;
1606         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1607         if (!notes)
1608                 goto cleanup;
1609         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1610         if (!fpu)
1611                 goto cleanup;
1612 #ifdef ELF_CORE_COPY_XFPREGS
1613         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1614         if (!xfpu)
1615                 goto cleanup;
1616 #endif
1617
1618         if (signr) {
1619                 struct elf_thread_status *tmp;
1620                 rcu_read_lock();
1621                 do_each_thread(g,p)
1622                         if (current->mm == p->mm && current != p) {
1623                                 tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
1624                                 if (!tmp) {
1625                                         rcu_read_unlock();
1626                                         goto cleanup;
1627                                 }
1628                                 tmp->thread = p;
1629                                 list_add(&tmp->list, &thread_list);
1630                         }
1631                 while_each_thread(g,p);
1632                 rcu_read_unlock();
1633                 list_for_each(t, &thread_list) {
1634                         struct elf_thread_status *tmp;
1635                         int sz;
1636
1637                         tmp = list_entry(t, struct elf_thread_status, list);
1638                         sz = elf_dump_thread_status(signr, tmp);
1639                         thread_status_size += sz;
1640                 }
1641         }
1642
1643         /* now collect the dump for the current */
1644         fill_prstatus(prstatus, current, signr);
1645         elf_core_copy_regs(&prstatus->pr_reg, regs);
1646
1647 #ifdef CONFIG_MMU
1648         segs = current->mm->map_count;
1649 #else
1650         segs = 0;
1651         for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1652             segs++;
1653 #endif
1654 #ifdef ELF_CORE_EXTRA_PHDRS
1655         segs += ELF_CORE_EXTRA_PHDRS;
1656 #endif
1657
1658         /* Set up header */
1659         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1660
1661         has_dumped = 1;
1662         current->flags |= PF_DUMPCORE;
1663
1664         /*
1665          * Set up the notes in similar form to SVR4 core dumps made
1666          * with info from their /proc.
1667          */
1668
1669         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1670         fill_psinfo(psinfo, current->group_leader, current->mm);
1671         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1672
1673         numnote = 2;
1674
1675         auxv = (elf_addr_t *) current->mm->saved_auxv;
1676
1677         i = 0;
1678         do
1679                 i += 2;
1680         while (auxv[i - 2] != AT_NULL);
1681         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1682                   i * sizeof(elf_addr_t), auxv);
1683
1684         /* Try to dump the FPU. */
1685         if ((prstatus->pr_fpvalid =
1686              elf_core_copy_task_fpregs(current, regs, fpu)))
1687                 fill_note(notes + numnote++,
1688                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1689 #ifdef ELF_CORE_COPY_XFPREGS
1690         if (elf_core_copy_task_xfpregs(current, xfpu))
1691                 fill_note(notes + numnote++,
1692                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1693 #endif
1694
1695         fs = get_fs();
1696         set_fs(KERNEL_DS);
1697
1698         DUMP_WRITE(elf, sizeof(*elf));
1699         offset += sizeof(*elf);                         /* Elf header */
1700         offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1701
1702         /* Write notes phdr entry */
1703         {
1704                 struct elf_phdr phdr;
1705                 int sz = 0;
1706
1707                 for (i = 0; i < numnote; i++)
1708                         sz += notesize(notes + i);
1709
1710                 sz += thread_status_size;
1711
1712                 fill_elf_note_phdr(&phdr, sz, offset);
1713                 offset += sz;
1714                 DUMP_WRITE(&phdr, sizeof(phdr));
1715         }
1716
1717         /* Page-align dumped data */
1718         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1719
1720         /*
1721          * We must use the same mm->flags while dumping core to avoid
1722          * inconsistency between the program headers and bodies, otherwise an
1723          * unusable core file can be generated.
1724          */
1725         mm_flags = current->mm->flags;
1726
1727         /* write program headers for segments dump */
1728         for (
1729 #ifdef CONFIG_MMU
1730                 vma = current->mm->mmap; vma; vma = vma->vm_next
1731 #else
1732                         vml = current->mm->context.vmlist; vml; vml = vml->next
1733 #endif
1734              ) {
1735                 struct elf_phdr phdr;
1736                 size_t sz;
1737
1738 #ifndef CONFIG_MMU
1739                 vma = vml->vma;
1740 #endif
1741
1742                 sz = vma->vm_end - vma->vm_start;
1743
1744                 phdr.p_type = PT_LOAD;
1745                 phdr.p_offset = offset;
1746                 phdr.p_vaddr = vma->vm_start;
1747                 phdr.p_paddr = 0;
1748                 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1749                 phdr.p_memsz = sz;
1750                 offset += phdr.p_filesz;
1751                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1752                 if (vma->vm_flags & VM_WRITE)
1753                         phdr.p_flags |= PF_W;
1754                 if (vma->vm_flags & VM_EXEC)
1755                         phdr.p_flags |= PF_X;
1756                 phdr.p_align = ELF_EXEC_PAGESIZE;
1757
1758                 DUMP_WRITE(&phdr, sizeof(phdr));
1759         }
1760
1761 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1762         ELF_CORE_WRITE_EXTRA_PHDRS;
1763 #endif
1764
1765         /* write out the notes section */
1766         for (i = 0; i < numnote; i++)
1767                 if (!writenote(notes + i, file))
1768                         goto end_coredump;
1769
1770         /* write out the thread status notes section */
1771         list_for_each(t, &thread_list) {
1772                 struct elf_thread_status *tmp =
1773                                 list_entry(t, struct elf_thread_status, list);
1774
1775                 for (i = 0; i < tmp->num_notes; i++)
1776                         if (!writenote(&tmp->notes[i], file))
1777                                 goto end_coredump;
1778         }
1779
1780         DUMP_SEEK(dataoff);
1781
1782         if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1783                 goto end_coredump;
1784
1785 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1786         ELF_CORE_WRITE_EXTRA_DATA;
1787 #endif
1788
1789         if (file->f_pos != offset) {
1790                 /* Sanity check */
1791                 printk(KERN_WARNING
1792                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1793                        file->f_pos, offset);
1794         }
1795
1796 end_coredump:
1797         set_fs(fs);
1798
1799 cleanup:
1800         while (!list_empty(&thread_list)) {
1801                 struct list_head *tmp = thread_list.next;
1802                 list_del(tmp);
1803                 kfree(list_entry(tmp, struct elf_thread_status, list));
1804         }
1805
1806         kfree(elf);
1807         kfree(prstatus);
1808         kfree(psinfo);
1809         kfree(notes);
1810         kfree(fpu);
1811 #ifdef ELF_CORE_COPY_XFPREGS
1812         kfree(xfpu);
1813 #endif
1814         return has_dumped;
1815 #undef NUM_NOTES
1816 }
1817
1818 #endif          /* USE_ELF_CORE_DUMP */