SAFE public projects git trees. - safe/jmp/linux-2.6/blob - fs/binfmt_elf_fdpic.c

   1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
   2  *
   3  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  * Derived from binfmt_elf.c
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14
  15 #include <linux/fs.h>
  16 #include <linux/stat.h>
  17 #include <linux/sched.h>
  18 #include <linux/mm.h>
  19 #include <linux/mman.h>
  20 #include <linux/errno.h>
  21 #include <linux/signal.h>
  22 #include <linux/binfmts.h>
  23 #include <linux/string.h>
  24 #include <linux/file.h>
  25 #include <linux/fcntl.h>
  26 #include <linux/slab.h>
  27 #include <linux/pagemap.h>
  28 #include <linux/security.h>
  29 #include <linux/highmem.h>
  30 #include <linux/highuid.h>
  31 #include <linux/personality.h>
  32 #include <linux/ptrace.h>
  33 #include <linux/init.h>
  34 #include <linux/elf.h>
  35 #include <linux/elf-fdpic.h>
  36 #include <linux/elfcore.h>
  37
  38 #include <asm/uaccess.h>
  39 #include <asm/param.h>
  40 #include <asm/pgalloc.h>
  41
  42 typedef char *elf_caddr_t;
  43
  44 #if 0
  45 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  46 #else
  47 #define kdebug(fmt, ...) do {} while(0)
  48 #endif
  49
  50 #if 0
  51 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  52 #else
  53 #define kdcore(fmt, ...) do {} while(0)
  54 #endif
  55
  56 MODULE_LICENSE("GPL");
  57
  58 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
  59 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  60 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  61                               struct mm_struct *, const char *);
  62
  63 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  64                                    struct elf_fdpic_params *,
  65                                    struct elf_fdpic_params *);
  66
  67 #ifndef CONFIG_MMU
  68 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
  69                                             unsigned long *);
  70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  71                                                    struct file *,
  72                                                    struct mm_struct *);
  73 #endif
  74
  75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  76                                              struct file *, struct mm_struct *);
  77
  78 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  79 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit);
  80 #endif
  81
  82 static struct linux_binfmt elf_fdpic_format = {
  83         .module         = THIS_MODULE,
  84         .load_binary    = load_elf_fdpic_binary,
  85 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  86         .core_dump      = elf_fdpic_core_dump,
  87 #endif
  88         .min_coredump   = ELF_EXEC_PAGESIZE,
  89 };
  90
  91 static int __init init_elf_fdpic_binfmt(void)
  92 {
  93         return register_binfmt(&elf_fdpic_format);
  94 }
  95
  96 static void __exit exit_elf_fdpic_binfmt(void)
  97 {
  98         unregister_binfmt(&elf_fdpic_format);
  99 }
 100
 101 core_initcall(init_elf_fdpic_binfmt);
 102 module_exit(exit_elf_fdpic_binfmt);
 103
 104 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
 105 {
 106         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 107                 return 0;
 108         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 109                 return 0;
 110         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
 111                 return 0;
 112         if (!file->f_op || !file->f_op->mmap)
 113                 return 0;
 114         return 1;
 115 }
 116
 117 /*****************************************************************************/
 118 /*
 119  * read the program headers table into memory
 120  */
 121 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 122                                  struct file *file)
 123 {
 124         struct elf32_phdr *phdr;
 125         unsigned long size;
 126         int retval, loop;
 127
 128         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 129                 return -ENOMEM;
 130         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 131                 return -ENOMEM;
 132
 133         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 134         params->phdrs = kmalloc(size, GFP_KERNEL);
 135         if (!params->phdrs)
 136                 return -ENOMEM;
 137
 138         retval = kernel_read(file, params->hdr.e_phoff,
 139                              (char *) params->phdrs, size);
 140         if (unlikely(retval != size))
 141                 return retval < 0 ? retval : -ENOEXEC;
 142
 143         /* determine stack size for this binary */
 144         phdr = params->phdrs;
 145         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 146                 if (phdr->p_type != PT_GNU_STACK)
 147                         continue;
 148
 149                 if (phdr->p_flags & PF_X)
 150                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 151                 else
 152                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 153
 154                 params->stack_size = phdr->p_memsz;
 155                 break;
 156         }
 157
 158         return 0;
 159 }
 160
 161 /*****************************************************************************/
 162 /*
 163  * load an fdpic binary into various bits of memory
 164  */
 165 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
 166                                  struct pt_regs *regs)
 167 {
 168         struct elf_fdpic_params exec_params, interp_params;
 169         struct elf_phdr *phdr;
 170         unsigned long stack_size, entryaddr;
 171 #ifdef ELF_FDPIC_PLAT_INIT
 172         unsigned long dynaddr;
 173 #endif
 174         struct file *interpreter = NULL; /* to shut gcc up */
 175         char *interpreter_name = NULL;
 176         int executable_stack;
 177         int retval, i;
 178
 179         kdebug("____ LOAD %d ____", current->pid);
 180
 181         memset(&exec_params, 0, sizeof(exec_params));
 182         memset(&interp_params, 0, sizeof(interp_params));
 183
 184         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 185         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 186
 187         /* check that this is a binary we know how to deal with */
 188         retval = -ENOEXEC;
 189         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
 190                 goto error;
 191
 192         /* read the program header table */
 193         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 194         if (retval < 0)
 195                 goto error;
 196
 197         /* scan for a program header that specifies an interpreter */
 198         phdr = exec_params.phdrs;
 199
 200         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 201                 switch (phdr->p_type) {
 202                 case PT_INTERP:
 203                         retval = -ENOMEM;
 204                         if (phdr->p_filesz > PATH_MAX)
 205                                 goto error;
 206                         retval = -ENOENT;
 207                         if (phdr->p_filesz < 2)
 208                                 goto error;
 209
 210                         /* read the name of the interpreter into memory */
 211                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 212                         if (!interpreter_name)
 213                                 goto error;
 214
 215                         retval = kernel_read(bprm->file,
 216                                              phdr->p_offset,
 217                                              interpreter_name,
 218                                              phdr->p_filesz);
 219                         if (unlikely(retval != phdr->p_filesz)) {
 220                                 if (retval >= 0)
 221                                         retval = -ENOEXEC;
 222                                 goto error;
 223                         }
 224
 225                         retval = -ENOENT;
 226                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 227                                 goto error;
 228
 229                         kdebug("Using ELF interpreter %s", interpreter_name);
 230
 231                         /* replace the program with the interpreter */
 232                         interpreter = open_exec(interpreter_name);
 233                         retval = PTR_ERR(interpreter);
 234                         if (IS_ERR(interpreter)) {
 235                                 interpreter = NULL;
 236                                 goto error;
 237                         }
 238
 239                         /*
 240                          * If the binary is not readable then enforce
 241                          * mm->dumpable = 0 regardless of the interpreter's
 242                          * permissions.
 243                          */
 244                         if (file_permission(interpreter, MAY_READ) < 0)
 245                                 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
 246
 247                         retval = kernel_read(interpreter, 0, bprm->buf,
 248                                              BINPRM_BUF_SIZE);
 249                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
 250                                 if (retval >= 0)
 251                                         retval = -ENOEXEC;
 252                                 goto error;
 253                         }
 254
 255                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 256                         break;
 257
 258                 case PT_LOAD:
 259 #ifdef CONFIG_MMU
 260                         if (exec_params.load_addr == 0)
 261                                 exec_params.load_addr = phdr->p_vaddr;
 262 #endif
 263                         break;
 264                 }
 265
 266         }
 267
 268         if (elf_check_const_displacement(&exec_params.hdr))
 269                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 270
 271         /* perform insanity checks on the interpreter */
 272         if (interpreter_name) {
 273                 retval = -ELIBBAD;
 274                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
 275                         goto error;
 276
 277                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 278
 279                 /* read the interpreter's program header table */
 280                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 281                 if (retval < 0)
 282                         goto error;
 283         }
 284
 285         stack_size = exec_params.stack_size;
 286         if (stack_size < interp_params.stack_size)
 287                 stack_size = interp_params.stack_size;
 288
 289         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 290                 executable_stack = EXSTACK_ENABLE_X;
 291         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 292                 executable_stack = EXSTACK_DISABLE_X;
 293         else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 294                 executable_stack = EXSTACK_ENABLE_X;
 295         else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 296                 executable_stack = EXSTACK_DISABLE_X;
 297         else
 298                 executable_stack = EXSTACK_DEFAULT;
 299
 300         retval = -ENOEXEC;
 301         if (stack_size == 0)
 302                 goto error;
 303
 304         if (elf_check_const_displacement(&interp_params.hdr))
 305                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 306
 307         /* flush all traces of the currently running executable */
 308         retval = flush_old_exec(bprm);
 309         if (retval)
 310                 goto error;
 311
 312         /* there's now no turning back... the old userspace image is dead,
 313          * defunct, deceased, etc. after this point we have to exit via
 314          * error_kill */
 315         set_personality(PER_LINUX_FDPIC);
 316         set_binfmt(&elf_fdpic_format);
 317
 318         current->mm->start_code = 0;
 319         current->mm->end_code = 0;
 320         current->mm->start_stack = 0;
 321         current->mm->start_data = 0;
 322         current->mm->end_data = 0;
 323         current->mm->context.exec_fdpic_loadmap = 0;
 324         current->mm->context.interp_fdpic_loadmap = 0;
 325
 326         current->flags &= ~PF_FORKNOEXEC;
 327
 328 #ifdef CONFIG_MMU
 329         elf_fdpic_arch_lay_out_mm(&exec_params,
 330                                   &interp_params,
 331                                   &current->mm->start_stack,
 332                                   &current->mm->start_brk);
 333
 334         retval = setup_arg_pages(bprm, current->mm->start_stack,
 335                                  executable_stack);
 336         if (retval < 0) {
 337                 send_sig(SIGKILL, current, 0);
 338                 goto error_kill;
 339         }
 340 #endif
 341
 342         /* load the executable and interpreter into memory */
 343         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 344                                     "executable");
 345         if (retval < 0)
 346                 goto error_kill;
 347
 348         if (interpreter_name) {
 349                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 350                                             current->mm, "interpreter");
 351                 if (retval < 0) {
 352                         printk(KERN_ERR "Unable to load interpreter\n");
 353                         goto error_kill;
 354                 }
 355
 356                 allow_write_access(interpreter);
 357                 fput(interpreter);
 358                 interpreter = NULL;
 359         }
 360
 361 #ifdef CONFIG_MMU
 362         if (!current->mm->start_brk)
 363                 current->mm->start_brk = current->mm->end_data;
 364
 365         current->mm->brk = current->mm->start_brk =
 366                 PAGE_ALIGN(current->mm->start_brk);
 367
 368 #else
 369         /* create a stack and brk area big enough for everyone
 370          * - the brk heap starts at the bottom and works up
 371          * - the stack starts at the top and works down
 372          */
 373         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 374         if (stack_size < PAGE_SIZE * 2)
 375                 stack_size = PAGE_SIZE * 2;
 376
 377         down_write(&current->mm->mmap_sem);
 378         current->mm->start_brk = do_mmap(NULL, 0, stack_size,
 379                                          PROT_READ | PROT_WRITE | PROT_EXEC,
 380                                          MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
 381                                          0);
 382
 383         if (IS_ERR_VALUE(current->mm->start_brk)) {
 384                 up_write(&current->mm->mmap_sem);
 385                 retval = current->mm->start_brk;
 386                 current->mm->start_brk = 0;
 387                 goto error_kill;
 388         }
 389
 390         up_write(&current->mm->mmap_sem);
 391
 392         current->mm->brk = current->mm->start_brk;
 393         current->mm->context.end_brk = current->mm->start_brk;
 394         current->mm->context.end_brk +=
 395                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 396         current->mm->start_stack = current->mm->start_brk + stack_size;
 397 #endif
 398
 399         install_exec_creds(bprm);
 400         current->flags &= ~PF_FORKNOEXEC;
 401         if (create_elf_fdpic_tables(bprm, current->mm,
 402                                     &exec_params, &interp_params) < 0)
 403                 goto error_kill;
 404
 405         kdebug("- start_code  %lx", current->mm->start_code);
 406         kdebug("- end_code    %lx", current->mm->end_code);
 407         kdebug("- start_data  %lx", current->mm->start_data);
 408         kdebug("- end_data    %lx", current->mm->end_data);
 409         kdebug("- start_brk   %lx", current->mm->start_brk);
 410         kdebug("- brk         %lx", current->mm->brk);
 411         kdebug("- start_stack %lx", current->mm->start_stack);
 412
 413 #ifdef ELF_FDPIC_PLAT_INIT
 414         /*
 415          * The ABI may specify that certain registers be set up in special
 416          * ways (on i386 %edx is the address of a DT_FINI function, for
 417          * example.  This macro performs whatever initialization to
 418          * the regs structure is required.
 419          */
 420         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 421         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 422                             dynaddr);
 423 #endif
 424
 425         /* everything is now ready... get the userspace context ready to roll */
 426         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 427         start_thread(regs, entryaddr, current->mm->start_stack);
 428
 429         retval = 0;
 430
 431 error:
 432         if (interpreter) {
 433                 allow_write_access(interpreter);
 434                 fput(interpreter);
 435         }
 436         kfree(interpreter_name);
 437         kfree(exec_params.phdrs);
 438         kfree(exec_params.loadmap);
 439         kfree(interp_params.phdrs);
 440         kfree(interp_params.loadmap);
 441         return retval;
 442
 443         /* unrecoverable error - kill the process */
 444 error_kill:
 445         send_sig(SIGSEGV, current, 0);
 446         goto error;
 447
 448 }
 449
 450 /*****************************************************************************/
 451
 452 #ifndef ELF_BASE_PLATFORM
 453 /*
 454  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 455  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 456  * will be copied to the user stack in the same manner as AT_PLATFORM.
 457  */
 458 #define ELF_BASE_PLATFORM NULL
 459 #endif
 460
 461 /*
 462  * present useful information to the program by shovelling it onto the new
 463  * process's stack
 464  */
 465 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 466                                    struct mm_struct *mm,
 467                                    struct elf_fdpic_params *exec_params,
 468                                    struct elf_fdpic_params *interp_params)
 469 {
 470         const struct cred *cred = current_cred();
 471         unsigned long sp, csp, nitems;
 472         elf_caddr_t __user *argv, *envp;
 473         size_t platform_len = 0, len;
 474         char *k_platform, *k_base_platform;
 475         char __user *u_platform, *u_base_platform, *p;
 476         long hwcap;
 477         int loop;
 478         int nr; /* reset for each csp adjustment */
 479
 480 #ifdef CONFIG_MMU
 481         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 482          * by the processes running on the same package. One thing we can do is
 483          * to shuffle the initial stack for them, so we give the architecture
 484          * an opportunity to do so here.
 485          */
 486         sp = arch_align_stack(bprm->p);
 487 #else
 488         sp = mm->start_stack;
 489
 490         /* stack the program arguments and environment */
 491         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 492                 return -EFAULT;
 493 #endif
 494
 495         hwcap = ELF_HWCAP;
 496
 497         /*
 498          * If this architecture has a platform capability string, copy it
 499          * to userspace.  In some cases (Sparc), this info is impossible
 500          * for userspace to get any other way, in others (i386) it is
 501          * merely difficult.
 502          */
 503         k_platform = ELF_PLATFORM;
 504         u_platform = NULL;
 505
 506         if (k_platform) {
 507                 platform_len = strlen(k_platform) + 1;
 508                 sp -= platform_len;
 509                 u_platform = (char __user *) sp;
 510                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 511                         return -EFAULT;
 512         }
 513
 514         /*
 515          * If this architecture has a "base" platform capability
 516          * string, copy it to userspace.
 517          */
 518         k_base_platform = ELF_BASE_PLATFORM;
 519         u_base_platform = NULL;
 520
 521         if (k_base_platform) {
 522                 platform_len = strlen(k_base_platform) + 1;
 523                 sp -= platform_len;
 524                 u_base_platform = (char __user *) sp;
 525                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 526                         return -EFAULT;
 527         }
 528
 529         sp &= ~7UL;
 530
 531         /* stack the load map(s) */
 532         len = sizeof(struct elf32_fdpic_loadmap);
 533         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 534         sp = (sp - len) & ~7UL;
 535         exec_params->map_addr = sp;
 536
 537         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 538                 return -EFAULT;
 539
 540         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 541
 542         if (interp_params->loadmap) {
 543                 len = sizeof(struct elf32_fdpic_loadmap);
 544                 len += sizeof(struct elf32_fdpic_loadseg) *
 545                         interp_params->loadmap->nsegs;
 546                 sp = (sp - len) & ~7UL;
 547                 interp_params->map_addr = sp;
 548
 549                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 550                                  len) != 0)
 551                         return -EFAULT;
 552
 553                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 554         }
 555
 556         /* force 16 byte _final_ alignment here for generality */
 557 #define DLINFO_ITEMS 15
 558
 559         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 560                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 561
 562         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
 563                 nitems++;
 564
 565         csp = sp;
 566         sp -= nitems * 2 * sizeof(unsigned long);
 567         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 568         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 569         sp -= 1 * sizeof(unsigned long);                /* argc */
 570
 571         csp -= sp & 15UL;
 572         sp -= sp & 15UL;
 573
 574         /* put the ELF interpreter info on the stack */
 575 #define NEW_AUX_ENT(id, val)                                            \
 576         do {                                                            \
 577                 struct { unsigned long _id, _val; } __user *ent;        \
 578                                                                         \
 579                 ent = (void __user *) csp;                              \
 580                 __put_user((id), &ent[nr]._id);                         \
 581                 __put_user((val), &ent[nr]._val);                       \
 582                 nr++;                                                   \
 583         } while (0)
 584
 585         nr = 0;
 586         csp -= 2 * sizeof(unsigned long);
 587         NEW_AUX_ENT(AT_NULL, 0);
 588         if (k_platform) {
 589                 nr = 0;
 590                 csp -= 2 * sizeof(unsigned long);
 591                 NEW_AUX_ENT(AT_PLATFORM,
 592                             (elf_addr_t) (unsigned long) u_platform);
 593         }
 594
 595         if (k_base_platform) {
 596                 nr = 0;
 597                 csp -= 2 * sizeof(unsigned long);
 598                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 599                             (elf_addr_t) (unsigned long) u_base_platform);
 600         }
 601
 602         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 603                 nr = 0;
 604                 csp -= 2 * sizeof(unsigned long);
 605                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 606         }
 607
 608         nr = 0;
 609         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 610         NEW_AUX_ENT(AT_HWCAP,   hwcap);
 611         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 612         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 613         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 614         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 615         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 616         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 617         NEW_AUX_ENT(AT_FLAGS,   0);
 618         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 619         NEW_AUX_ENT(AT_UID,     (elf_addr_t) cred->uid);
 620         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) cred->euid);
 621         NEW_AUX_ENT(AT_GID,     (elf_addr_t) cred->gid);
 622         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) cred->egid);
 623         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
 624         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 625
 626 #ifdef ARCH_DLINFO
 627         nr = 0;
 628         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 629
 630         /* ARCH_DLINFO must come last so platform specific code can enforce
 631          * special alignment requirements on the AUXV if necessary (eg. PPC).
 632          */
 633         ARCH_DLINFO;
 634 #endif
 635 #undef NEW_AUX_ENT
 636
 637         /* allocate room for argv[] and envv[] */
 638         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 639         envp = (elf_caddr_t __user *) csp;
 640         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 641         argv = (elf_caddr_t __user *) csp;
 642
 643         /* stack argc */
 644         csp -= sizeof(unsigned long);
 645         __put_user(bprm->argc, (unsigned long __user *) csp);
 646
 647         BUG_ON(csp != sp);
 648
 649         /* fill in the argv[] array */
 650 #ifdef CONFIG_MMU
 651         current->mm->arg_start = bprm->p;
 652 #else
 653         current->mm->arg_start = current->mm->start_stack -
 654                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 655 #endif
 656
 657         p = (char __user *) current->mm->arg_start;
 658         for (loop = bprm->argc; loop > 0; loop--) {
 659                 __put_user((elf_caddr_t) p, argv++);
 660                 len = strnlen_user(p, MAX_ARG_STRLEN);
 661                 if (!len || len > MAX_ARG_STRLEN)
 662                         return -EINVAL;
 663                 p += len;
 664         }
 665         __put_user(NULL, argv);
 666         current->mm->arg_end = (unsigned long) p;
 667
 668         /* fill in the envv[] array */
 669         current->mm->env_start = (unsigned long) p;
 670         for (loop = bprm->envc; loop > 0; loop--) {
 671                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 672                 len = strnlen_user(p, MAX_ARG_STRLEN);
 673                 if (!len || len > MAX_ARG_STRLEN)
 674                         return -EINVAL;
 675                 p += len;
 676         }
 677         __put_user(NULL, envp);
 678         current->mm->env_end = (unsigned long) p;
 679
 680         mm->start_stack = (unsigned long) sp;
 681         return 0;
 682 }
 683
 684 /*****************************************************************************/
 685 /*
 686  * transfer the program arguments and environment from the holding pages onto
 687  * the stack
 688  */
 689 #ifndef CONFIG_MMU
 690 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 691                                             unsigned long *_sp)
 692 {
 693         unsigned long index, stop, sp;
 694         char *src;
 695         int ret = 0;
 696
 697         stop = bprm->p >> PAGE_SHIFT;
 698         sp = *_sp;
 699
 700         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 701                 src = kmap(bprm->page[index]);
 702                 sp -= PAGE_SIZE;
 703                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 704                         ret = -EFAULT;
 705                 kunmap(bprm->page[index]);
 706                 if (ret < 0)
 707                         goto out;
 708         }
 709
 710         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 711
 712 out:
 713         return ret;
 714 }
 715 #endif
 716
 717 /*****************************************************************************/
 718 /*
 719  * load the appropriate binary image (executable or interpreter) into memory
 720  * - we assume no MMU is available
 721  * - if no other PIC bits are set in params->hdr->e_flags
 722  *   - we assume that the LOADable segments in the binary are independently relocatable
 723  *   - we assume R/O executable segments are shareable
 724  * - else
 725  *   - we assume the loadable parts of the image to require fixed displacement
 726  *   - the image is not shareable
 727  */
 728 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 729                               struct file *file,
 730                               struct mm_struct *mm,
 731                               const char *what)
 732 {
 733         struct elf32_fdpic_loadmap *loadmap;
 734 #ifdef CONFIG_MMU
 735         struct elf32_fdpic_loadseg *mseg;
 736 #endif
 737         struct elf32_fdpic_loadseg *seg;
 738         struct elf32_phdr *phdr;
 739         unsigned long load_addr, stop;
 740         unsigned nloads, tmp;
 741         size_t size;
 742         int loop, ret;
 743
 744         /* allocate a load map table */
 745         nloads = 0;
 746         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 747                 if (params->phdrs[loop].p_type == PT_LOAD)
 748                         nloads++;
 749
 750         if (nloads == 0)
 751                 return -ELIBBAD;
 752
 753         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 754         loadmap = kzalloc(size, GFP_KERNEL);
 755         if (!loadmap)
 756                 return -ENOMEM;
 757
 758         params->loadmap = loadmap;
 759
 760         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 761         loadmap->nsegs = nloads;
 762
 763         load_addr = params->load_addr;
 764         seg = loadmap->segs;
 765
 766         /* map the requested LOADs into the memory space */
 767         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 768         case ELF_FDPIC_FLAG_CONSTDISP:
 769         case ELF_FDPIC_FLAG_CONTIGUOUS:
 770 #ifndef CONFIG_MMU
 771                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 772                 if (ret < 0)
 773                         return ret;
 774                 break;
 775 #endif
 776         default:
 777                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 778                 if (ret < 0)
 779                         return ret;
 780                 break;
 781         }
 782
 783         /* map the entry point */
 784         if (params->hdr.e_entry) {
 785                 seg = loadmap->segs;
 786                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 787                         if (params->hdr.e_entry >= seg->p_vaddr &&
 788                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 789                                 params->entry_addr =
 790                                         (params->hdr.e_entry - seg->p_vaddr) +
 791                                         seg->addr;
 792                                 break;
 793                         }
 794                 }
 795         }
 796
 797         /* determine where the program header table has wound up if mapped */
 798         stop = params->hdr.e_phoff;
 799         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 800         phdr = params->phdrs;
 801
 802         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 803                 if (phdr->p_type != PT_LOAD)
 804                         continue;
 805
 806                 if (phdr->p_offset > params->hdr.e_phoff ||
 807                     phdr->p_offset + phdr->p_filesz < stop)
 808                         continue;
 809
 810                 seg = loadmap->segs;
 811                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 812                         if (phdr->p_vaddr >= seg->p_vaddr &&
 813                             phdr->p_vaddr + phdr->p_filesz <=
 814                             seg->p_vaddr + seg->p_memsz) {
 815                                 params->ph_addr =
 816                                         (phdr->p_vaddr - seg->p_vaddr) +
 817                                         seg->addr +
 818                                         params->hdr.e_phoff - phdr->p_offset;
 819                                 break;
 820                         }
 821                 }
 822                 break;
 823         }
 824
 825         /* determine where the dynamic section has wound up if there is one */
 826         phdr = params->phdrs;
 827         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 828                 if (phdr->p_type != PT_DYNAMIC)
 829                         continue;
 830
 831                 seg = loadmap->segs;
 832                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 833                         if (phdr->p_vaddr >= seg->p_vaddr &&
 834                             phdr->p_vaddr + phdr->p_memsz <=
 835                             seg->p_vaddr + seg->p_memsz) {
 836                                 params->dynamic_addr =
 837                                         (phdr->p_vaddr - seg->p_vaddr) +
 838                                         seg->addr;
 839
 840                                 /* check the dynamic section contains at least
 841                                  * one item, and that the last item is a NULL
 842                                  * entry */
 843                                 if (phdr->p_memsz == 0 ||
 844                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 845                                         goto dynamic_error;
 846
 847                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 848                                 if (((Elf32_Dyn *)
 849                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
 850                                         goto dynamic_error;
 851                                 break;
 852                         }
 853                 }
 854                 break;
 855         }
 856
 857         /* now elide adjacent segments in the load map on MMU linux
 858          * - on uClinux the holes between may actually be filled with system
 859          *   stuff or stuff from other processes
 860          */
 861 #ifdef CONFIG_MMU
 862         nloads = loadmap->nsegs;
 863         mseg = loadmap->segs;
 864         seg = mseg + 1;
 865         for (loop = 1; loop < nloads; loop++) {
 866                 /* see if we have a candidate for merging */
 867                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 868                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 869                         if (load_addr == (seg->addr & PAGE_MASK)) {
 870                                 mseg->p_memsz +=
 871                                         load_addr -
 872                                         (mseg->addr + mseg->p_memsz);
 873                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 874                                 mseg->p_memsz += seg->p_memsz;
 875                                 loadmap->nsegs--;
 876                                 continue;
 877                         }
 878                 }
 879
 880                 mseg++;
 881                 if (mseg != seg)
 882                         *mseg = *seg;
 883         }
 884 #endif
 885
 886         kdebug("Mapped Object [%s]:", what);
 887         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 888         kdebug("- entry    : %lx", params->entry_addr);
 889         kdebug("- PHDR[]   : %lx", params->ph_addr);
 890         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 891         seg = loadmap->segs;
 892         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 893                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 894                        loop,
 895                        seg->addr, seg->addr + seg->p_memsz - 1,
 896                        seg->p_vaddr, seg->p_memsz);
 897
 898         return 0;
 899
 900 dynamic_error:
 901         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 902                what, file->f_path.dentry->d_inode->i_ino);
 903         return -ELIBBAD;
 904 }
 905
 906 /*****************************************************************************/
 907 /*
 908  * map a file with constant displacement under uClinux
 909  */
 910 #ifndef CONFIG_MMU
 911 static int elf_fdpic_map_file_constdisp_on_uclinux(
 912         struct elf_fdpic_params *params,
 913         struct file *file,
 914         struct mm_struct *mm)
 915 {
 916         struct elf32_fdpic_loadseg *seg;
 917         struct elf32_phdr *phdr;
 918         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 919         loff_t fpos;
 920         int loop, ret;
 921
 922         load_addr = params->load_addr;
 923         seg = params->loadmap->segs;
 924
 925         /* determine the bounds of the contiguous overall allocation we must
 926          * make */
 927         phdr = params->phdrs;
 928         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 929                 if (params->phdrs[loop].p_type != PT_LOAD)
 930                         continue;
 931
 932                 if (base > phdr->p_vaddr)
 933                         base = phdr->p_vaddr;
 934                 if (top < phdr->p_vaddr + phdr->p_memsz)
 935                         top = phdr->p_vaddr + phdr->p_memsz;
 936         }
 937
 938         /* allocate one big anon block for everything */
 939         mflags = MAP_PRIVATE;
 940         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 941                 mflags |= MAP_EXECUTABLE;
 942
 943         down_write(&mm->mmap_sem);
 944         maddr = do_mmap(NULL, load_addr, top - base,
 945                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 946         up_write(&mm->mmap_sem);
 947         if (IS_ERR_VALUE(maddr))
 948                 return (int) maddr;
 949
 950         if (load_addr != 0)
 951                 load_addr += PAGE_ALIGN(top - base);
 952
 953         /* and then load the file segments into it */
 954         phdr = params->phdrs;
 955         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 956                 if (params->phdrs[loop].p_type != PT_LOAD)
 957                         continue;
 958
 959                 fpos = phdr->p_offset;
 960
 961                 seg->addr = maddr + (phdr->p_vaddr - base);
 962                 seg->p_vaddr = phdr->p_vaddr;
 963                 seg->p_memsz = phdr->p_memsz;
 964
 965                 ret = file->f_op->read(file, (void *) seg->addr,
 966                                        phdr->p_filesz, &fpos);
 967                 if (ret < 0)
 968                         return ret;
 969
 970                 /* map the ELF header address if in this segment */
 971                 if (phdr->p_offset == 0)
 972                         params->elfhdr_addr = seg->addr;
 973
 974                 /* clear any space allocated but not loaded */
 975                 if (phdr->p_filesz < phdr->p_memsz)
 976                         clear_user((void *) (seg->addr + phdr->p_filesz),
 977                                    phdr->p_memsz - phdr->p_filesz);
 978
 979                 if (mm) {
 980                         if (phdr->p_flags & PF_X) {
 981                                 if (!mm->start_code) {
 982                                         mm->start_code = seg->addr;
 983                                         mm->end_code = seg->addr +
 984                                                 phdr->p_memsz;
 985                                 }
 986                         } else if (!mm->start_data) {
 987                                 mm->start_data = seg->addr;
 988 #ifndef CONFIG_MMU
 989                                 mm->end_data = seg->addr + phdr->p_memsz;
 990 #endif
 991                         }
 992
 993 #ifdef CONFIG_MMU
 994                         if (seg->addr + phdr->p_memsz > mm->end_data)
 995                                 mm->end_data = seg->addr + phdr->p_memsz;
 996 #endif
 997                 }
 998
 999                 seg++;
1000         }
1001
1002         return 0;
1003 }
1004 #endif
1005
1006 /*****************************************************************************/
1007 /*
1008  * map a binary by direct mmap() of the individual PT_LOAD segments
1009  */
1010 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1011                                              struct file *file,
1012                                              struct mm_struct *mm)
1013 {
1014         struct elf32_fdpic_loadseg *seg;
1015         struct elf32_phdr *phdr;
1016         unsigned long load_addr, delta_vaddr;
1017         int loop, dvset;
1018
1019         load_addr = params->load_addr;
1020         delta_vaddr = 0;
1021         dvset = 0;
1022
1023         seg = params->loadmap->segs;
1024
1025         /* deal with each load segment separately */
1026         phdr = params->phdrs;
1027         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1028                 unsigned long maddr, disp, excess, excess1;
1029                 int prot = 0, flags;
1030
1031                 if (phdr->p_type != PT_LOAD)
1032                         continue;
1033
1034                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1035                        (unsigned long) phdr->p_vaddr,
1036                        (unsigned long) phdr->p_offset,
1037                        (unsigned long) phdr->p_filesz,
1038                        (unsigned long) phdr->p_memsz);
1039
1040                 /* determine the mapping parameters */
1041                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1042                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1043                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1044
1045                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1046                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1047                         flags |= MAP_EXECUTABLE;
1048
1049                 maddr = 0;
1050
1051                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1052                 case ELF_FDPIC_FLAG_INDEPENDENT:
1053                         /* PT_LOADs are independently locatable */
1054                         break;
1055
1056                 case ELF_FDPIC_FLAG_HONOURVADDR:
1057                         /* the specified virtual address must be honoured */
1058                         maddr = phdr->p_vaddr;
1059                         flags |= MAP_FIXED;
1060                         break;
1061
1062                 case ELF_FDPIC_FLAG_CONSTDISP:
1063                         /* constant displacement
1064                          * - can be mapped anywhere, but must be mapped as a
1065                          *   unit
1066                          */
1067                         if (!dvset) {
1068                                 maddr = load_addr;
1069                                 delta_vaddr = phdr->p_vaddr;
1070                                 dvset = 1;
1071                         } else {
1072                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1073                                 flags |= MAP_FIXED;
1074                         }
1075                         break;
1076
1077                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1078                         /* contiguity handled later */
1079                         break;
1080
1081                 default:
1082                         BUG();
1083                 }
1084
1085                 maddr &= PAGE_MASK;
1086
1087                 /* create the mapping */
1088                 disp = phdr->p_vaddr & ~PAGE_MASK;
1089                 down_write(&mm->mmap_sem);
1090                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1091                                 phdr->p_offset - disp);
1092                 up_write(&mm->mmap_sem);
1093
1094                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1095                        loop, phdr->p_memsz + disp, prot, flags,
1096                        phdr->p_offset - disp, maddr);
1097
1098                 if (IS_ERR_VALUE(maddr))
1099                         return (int) maddr;
1100
1101                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1102                     ELF_FDPIC_FLAG_CONTIGUOUS)
1103                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1104
1105                 seg->addr = maddr + disp;
1106                 seg->p_vaddr = phdr->p_vaddr;
1107                 seg->p_memsz = phdr->p_memsz;
1108
1109                 /* map the ELF header address if in this segment */
1110                 if (phdr->p_offset == 0)
1111                         params->elfhdr_addr = seg->addr;
1112
1113                 /* clear the bit between beginning of mapping and beginning of
1114                  * PT_LOAD */
1115                 if (prot & PROT_WRITE && disp > 0) {
1116                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1117                         clear_user((void __user *) maddr, disp);
1118                         maddr += disp;
1119                 }
1120
1121                 /* clear any space allocated but not loaded
1122                  * - on uClinux we can just clear the lot
1123                  * - on MMU linux we'll get a SIGBUS beyond the last page
1124                  *   extant in the file
1125                  */
1126                 excess = phdr->p_memsz - phdr->p_filesz;
1127                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1128
1129 #ifdef CONFIG_MMU
1130                 if (excess > excess1) {
1131                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1132                         unsigned long xmaddr;
1133
1134                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1135                         down_write(&mm->mmap_sem);
1136                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1137                                          prot, flags, 0);
1138                         up_write(&mm->mmap_sem);
1139
1140                         kdebug("mmap[%d] <anon>"
1141                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1142                                loop, xaddr, excess - excess1, prot, flags,
1143                                xmaddr);
1144
1145                         if (xmaddr != xaddr)
1146                                 return -ENOMEM;
1147                 }
1148
1149                 if (prot & PROT_WRITE && excess1 > 0) {
1150                         kdebug("clear[%d] ad=%lx sz=%lx",
1151                                loop, maddr + phdr->p_filesz, excess1);
1152                         clear_user((void __user *) maddr + phdr->p_filesz,
1153                                    excess1);
1154                 }
1155
1156 #else
1157                 if (excess > 0) {
1158                         kdebug("clear[%d] ad=%lx sz=%lx",
1159                                loop, maddr + phdr->p_filesz, excess);
1160                         clear_user((void *) maddr + phdr->p_filesz, excess);
1161                 }
1162 #endif
1163
1164                 if (mm) {
1165                         if (phdr->p_flags & PF_X) {
1166                                 if (!mm->start_code) {
1167                                         mm->start_code = maddr;
1168                                         mm->end_code = maddr + phdr->p_memsz;
1169                                 }
1170                         } else if (!mm->start_data) {
1171                                 mm->start_data = maddr;
1172                                 mm->end_data = maddr + phdr->p_memsz;
1173                         }
1174                 }
1175
1176                 seg++;
1177         }
1178
1179         return 0;
1180 }
1181
1182 /*****************************************************************************/
1183 /*
1184  * ELF-FDPIC core dumper
1185  *
1186  * Modelled on fs/exec.c:aout_core_dump()
1187  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1188  *
1189  * Modelled on fs/binfmt_elf.c core dumper
1190  */
1191 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1192
1193 /*
1194  * These are the only things you should do on a core-file: use only these
1195  * functions to write out all the necessary info.
1196  */
1197 static int dump_write(struct file *file, const void *addr, int nr)
1198 {
1199         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1200 }
1201
1202 static int dump_seek(struct file *file, loff_t off)
1203 {
1204         if (file->f_op->llseek) {
1205                 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1206                         return 0;
1207         } else {
1208                 file->f_pos = off;
1209         }
1210         return 1;
1211 }
1212
1213 /*
1214  * Decide whether a segment is worth dumping; default is yes to be
1215  * sure (missing info is worse than too much; etc).
1216  * Personally I'd include everything, and use the coredump limit...
1217  *
1218  * I think we should skip something. But I am not sure how. H.J.
1219  */
1220 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1221 {
1222         int dump_ok;
1223
1224         /* Do not dump I/O mapped devices or special mappings */
1225         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1226                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1227                 return 0;
1228         }
1229
1230         /* If we may not read the contents, don't allow us to dump
1231          * them either. "dump_write()" can't handle it anyway.
1232          */
1233         if (!(vma->vm_flags & VM_READ)) {
1234                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1235                 return 0;
1236         }
1237
1238         /* By default, dump shared memory if mapped from an anonymous file. */
1239         if (vma->vm_flags & VM_SHARED) {
1240                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1241                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1242                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1243                                vma->vm_flags, dump_ok ? "yes" : "no");
1244                         return dump_ok;
1245                 }
1246
1247                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1248                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1249                        vma->vm_flags, dump_ok ? "yes" : "no");
1250                 return dump_ok;
1251         }
1252
1253 #ifdef CONFIG_MMU
1254         /* By default, if it hasn't been written to, don't write it out */
1255         if (!vma->anon_vma) {
1256                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1257                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1258                        vma->vm_flags, dump_ok ? "yes" : "no");
1259                 return dump_ok;
1260         }
1261 #endif
1262
1263         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1264         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1265                dump_ok ? "yes" : "no");
1266         return dump_ok;
1267 }
1268
1269 /* An ELF note in memory */
1270 struct memelfnote
1271 {
1272         const char *name;
1273         int type;
1274         unsigned int datasz;
1275         void *data;
1276 };
1277
1278 static int notesize(struct memelfnote *en)
1279 {
1280         int sz;
1281
1282         sz = sizeof(struct elf_note);
1283         sz += roundup(strlen(en->name) + 1, 4);
1284         sz += roundup(en->datasz, 4);
1285
1286         return sz;
1287 }
1288
1289 /* #define DEBUG */
1290
1291 #define DUMP_WRITE(addr, nr)    \
1292         do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1293 #define DUMP_SEEK(off)  \
1294         do { if (!dump_seek(file, (off))) return 0; } while(0)
1295
1296 static int writenote(struct memelfnote *men, struct file *file)
1297 {
1298         struct elf_note en;
1299
1300         en.n_namesz = strlen(men->name) + 1;
1301         en.n_descsz = men->datasz;
1302         en.n_type = men->type;
1303
1304         DUMP_WRITE(&en, sizeof(en));
1305         DUMP_WRITE(men->name, en.n_namesz);
1306         /* XXX - cast from long long to long to avoid need for libgcc.a */
1307         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1308         DUMP_WRITE(men->data, men->datasz);
1309         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1310
1311         return 1;
1312 }
1313 #undef DUMP_WRITE
1314 #undef DUMP_SEEK
1315
1316 #define DUMP_WRITE(addr, nr)    \
1317         if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1318                 goto end_coredump;
1319 #define DUMP_SEEK(off)  \
1320         if (!dump_seek(file, (off))) \
1321                 goto end_coredump;
1322
1323 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1324 {
1325         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1326         elf->e_ident[EI_CLASS] = ELF_CLASS;
1327         elf->e_ident[EI_DATA] = ELF_DATA;
1328         elf->e_ident[EI_VERSION] = EV_CURRENT;
1329         elf->e_ident[EI_OSABI] = ELF_OSABI;
1330         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1331
1332         elf->e_type = ET_CORE;
1333         elf->e_machine = ELF_ARCH;
1334         elf->e_version = EV_CURRENT;
1335         elf->e_entry = 0;
1336         elf->e_phoff = sizeof(struct elfhdr);
1337         elf->e_shoff = 0;
1338         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1339         elf->e_ehsize = sizeof(struct elfhdr);
1340         elf->e_phentsize = sizeof(struct elf_phdr);
1341         elf->e_phnum = segs;
1342         elf->e_shentsize = 0;
1343         elf->e_shnum = 0;
1344         elf->e_shstrndx = 0;
1345         return;
1346 }
1347
1348 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1349 {
1350         phdr->p_type = PT_NOTE;
1351         phdr->p_offset = offset;
1352         phdr->p_vaddr = 0;
1353         phdr->p_paddr = 0;
1354         phdr->p_filesz = sz;
1355         phdr->p_memsz = 0;
1356         phdr->p_flags = 0;
1357         phdr->p_align = 0;
1358         return;
1359 }
1360
1361 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1362                 unsigned int sz, void *data)
1363 {
1364         note->name = name;
1365         note->type = type;
1366         note->datasz = sz;
1367         note->data = data;
1368         return;
1369 }
1370
1371 /*
1372  * fill up all the fields in prstatus from the given task struct, except
1373  * registers which need to be filled up seperately.
1374  */
1375 static void fill_prstatus(struct elf_prstatus *prstatus,
1376                           struct task_struct *p, long signr)
1377 {
1378         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1379         prstatus->pr_sigpend = p->pending.signal.sig[0];
1380         prstatus->pr_sighold = p->blocked.sig[0];
1381         prstatus->pr_pid = task_pid_vnr(p);
1382         prstatus->pr_ppid = task_pid_vnr(p->parent);
1383         prstatus->pr_pgrp = task_pgrp_vnr(p);
1384         prstatus->pr_sid = task_session_vnr(p);
1385         if (thread_group_leader(p)) {
1386                 struct task_cputime cputime;
1387
1388                 /*
1389                  * This is the record for the group leader.  It shows the
1390                  * group-wide total, not its individual thread total.
1391                  */
1392                 thread_group_cputime(p, &cputime);
1393                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1394                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1395         } else {
1396                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1397                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1398         }
1399         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1400         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1401
1402         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1403         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1404 }
1405
1406 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1407                        struct mm_struct *mm)
1408 {
1409         const struct cred *cred;
1410         unsigned int i, len;
1411
1412         /* first copy the parameters from user space */
1413         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1414
1415         len = mm->arg_end - mm->arg_start;
1416         if (len >= ELF_PRARGSZ)
1417                 len = ELF_PRARGSZ - 1;
1418         if (copy_from_user(&psinfo->pr_psargs,
1419                            (const char __user *) mm->arg_start, len))
1420                 return -EFAULT;
1421         for (i = 0; i < len; i++)
1422                 if (psinfo->pr_psargs[i] == 0)
1423                         psinfo->pr_psargs[i] = ' ';
1424         psinfo->pr_psargs[len] = 0;
1425
1426         psinfo->pr_pid = task_pid_vnr(p);
1427         psinfo->pr_ppid = task_pid_vnr(p->parent);
1428         psinfo->pr_pgrp = task_pgrp_vnr(p);
1429         psinfo->pr_sid = task_session_vnr(p);
1430
1431         i = p->state ? ffz(~p->state) + 1 : 0;
1432         psinfo->pr_state = i;
1433         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1434         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1435         psinfo->pr_nice = task_nice(p);
1436         psinfo->pr_flag = p->flags;
1437         rcu_read_lock();
1438         cred = __task_cred(p);
1439         SET_UID(psinfo->pr_uid, cred->uid);
1440         SET_GID(psinfo->pr_gid, cred->gid);
1441         rcu_read_unlock();
1442         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1443
1444         return 0;
1445 }
1446
1447 /* Here is the structure in which status of each thread is captured. */
1448 struct elf_thread_status
1449 {
1450         struct list_head list;
1451         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1452         elf_fpregset_t fpu;             /* NT_PRFPREG */
1453         struct task_struct *thread;
1454 #ifdef ELF_CORE_COPY_XFPREGS
1455         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1456 #endif
1457         struct memelfnote notes[3];
1458         int num_notes;
1459 };
1460
1461 /*
1462  * In order to add the specific thread information for the elf file format,
1463  * we need to keep a linked list of every thread's pr_status and then create
1464  * a single section for them in the final core file.
1465  */
1466 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1467 {
1468         struct task_struct *p = t->thread;
1469         int sz = 0;
1470
1471         t->num_notes = 0;
1472
1473         fill_prstatus(&t->prstatus, p, signr);
1474         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1475
1476         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1477                   &t->prstatus);
1478         t->num_notes++;
1479         sz += notesize(&t->notes[0]);
1480
1481         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1482         if (t->prstatus.pr_fpvalid) {
1483                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1484                           &t->fpu);
1485                 t->num_notes++;
1486                 sz += notesize(&t->notes[1]);
1487         }
1488
1489 #ifdef ELF_CORE_COPY_XFPREGS
1490         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1491                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1492                           sizeof(t->xfpu), &t->xfpu);
1493                 t->num_notes++;
1494                 sz += notesize(&t->notes[2]);
1495         }
1496 #endif
1497         return sz;
1498 }
1499
1500 /*
1501  * dump the segments for an MMU process
1502  */
1503 #ifdef CONFIG_MMU
1504 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1505                            unsigned long *limit, unsigned long mm_flags)
1506 {
1507         struct vm_area_struct *vma;
1508
1509         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1510                 unsigned long addr;
1511
1512                 if (!maydump(vma, mm_flags))
1513                         continue;
1514
1515                 for (addr = vma->vm_start;
1516                      addr < vma->vm_end;
1517                      addr += PAGE_SIZE
1518                      ) {
1519                         struct vm_area_struct *vma;
1520                         struct page *page;
1521
1522                         if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1523                                            &page, &vma) <= 0) {
1524                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1525                         }
1526                         else if (page == ZERO_PAGE(0)) {
1527                                 page_cache_release(page);
1528                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1529                         }
1530                         else {
1531                                 void *kaddr;
1532
1533                                 flush_cache_page(vma, addr, page_to_pfn(page));
1534                                 kaddr = kmap(page);
1535                                 if ((*size += PAGE_SIZE) > *limit ||
1536                                     !dump_write(file, kaddr, PAGE_SIZE)
1537                                     ) {
1538                                         kunmap(page);
1539                                         page_cache_release(page);
1540                                         return -EIO;
1541                                 }
1542                                 kunmap(page);
1543                                 page_cache_release(page);
1544                         }
1545                 }
1546         }
1547
1548         return 0;
1549
1550 end_coredump:
1551         return -EFBIG;
1552 }
1553 #endif
1554
1555 /*
1556  * dump the segments for a NOMMU process
1557  */
1558 #ifndef CONFIG_MMU
1559 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1560                            unsigned long *limit, unsigned long mm_flags)
1561 {
1562         struct vm_area_struct *vma;
1563
1564         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1565                 if (!maydump(vma, mm_flags))
1566                         continue;
1567
1568                 if ((*size += PAGE_SIZE) > *limit)
1569                         return -EFBIG;
1570
1571                 if (!dump_write(file, (void *) vma->vm_start,
1572                                 vma->vm_end - vma->vm_start))
1573                         return -EIO;
1574         }
1575
1576         return 0;
1577 }
1578 #endif
1579
1580 /*
1581  * Actual dumper
1582  *
1583  * This is a two-pass process; first we find the offsets of the bits,
1584  * and then they are actually written out.  If we run out of core limit
1585  * we just truncate.
1586  */
1587 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1588                                struct file *file, unsigned long limit)
1589 {
1590 #define NUM_NOTES       6
1591         int has_dumped = 0;
1592         mm_segment_t fs;
1593         int segs;
1594         size_t size = 0;
1595         int i;
1596         struct vm_area_struct *vma;
1597         struct elfhdr *elf = NULL;
1598         loff_t offset = 0, dataoff;
1599         int numnote;
1600         struct memelfnote *notes = NULL;
1601         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1602         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1603         LIST_HEAD(thread_list);
1604         struct list_head *t;
1605         elf_fpregset_t *fpu = NULL;
1606 #ifdef ELF_CORE_COPY_XFPREGS
1607         elf_fpxregset_t *xfpu = NULL;
1608 #endif
1609         int thread_status_size = 0;
1610         elf_addr_t *auxv;
1611         unsigned long mm_flags;
1612
1613         /*
1614          * We no longer stop all VM operations.
1615          *
1616          * This is because those proceses that could possibly change map_count
1617          * or the mmap / vma pages are now blocked in do_exit on current
1618          * finishing this core dump.
1619          *
1620          * Only ptrace can touch these memory addresses, but it doesn't change
1621          * the map_count or the pages allocated. So no possibility of crashing
1622          * exists while dumping the mm->vm_next areas to the core file.
1623          */
1624
1625         /* alloc memory for large data structures: too large to be on stack */
1626         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1627         if (!elf)
1628                 goto cleanup;
1629         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1630         if (!prstatus)
1631                 goto cleanup;
1632         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1633         if (!psinfo)
1634                 goto cleanup;
1635         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1636         if (!notes)
1637                 goto cleanup;
1638         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1639         if (!fpu)
1640                 goto cleanup;
1641 #ifdef ELF_CORE_COPY_XFPREGS
1642         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1643         if (!xfpu)
1644                 goto cleanup;
1645 #endif
1646
1647         if (signr) {
1648                 struct core_thread *ct;
1649                 struct elf_thread_status *tmp;
1650
1651                 for (ct = current->mm->core_state->dumper.next;
1652                                                 ct; ct = ct->next) {
1653                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1654                         if (!tmp)
1655                                 goto cleanup;
1656
1657                         tmp->thread = ct->task;
1658                         list_add(&tmp->list, &thread_list);
1659                 }
1660
1661                 list_for_each(t, &thread_list) {
1662                         struct elf_thread_status *tmp;
1663                         int sz;
1664
1665                         tmp = list_entry(t, struct elf_thread_status, list);
1666                         sz = elf_dump_thread_status(signr, tmp);
1667                         thread_status_size += sz;
1668                 }
1669         }
1670
1671         /* now collect the dump for the current */
1672         fill_prstatus(prstatus, current, signr);
1673         elf_core_copy_regs(&prstatus->pr_reg, regs);
1674
1675         segs = current->mm->map_count;
1676 #ifdef ELF_CORE_EXTRA_PHDRS
1677         segs += ELF_CORE_EXTRA_PHDRS;
1678 #endif
1679
1680         /* Set up header */
1681         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1682
1683         has_dumped = 1;
1684         current->flags |= PF_DUMPCORE;
1685
1686         /*
1687          * Set up the notes in similar form to SVR4 core dumps made
1688          * with info from their /proc.
1689          */
1690
1691         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1692         fill_psinfo(psinfo, current->group_leader, current->mm);
1693         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1694
1695         numnote = 2;
1696
1697         auxv = (elf_addr_t *) current->mm->saved_auxv;
1698
1699         i = 0;
1700         do
1701                 i += 2;
1702         while (auxv[i - 2] != AT_NULL);
1703         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1704                   i * sizeof(elf_addr_t), auxv);
1705
1706         /* Try to dump the FPU. */
1707         if ((prstatus->pr_fpvalid =
1708              elf_core_copy_task_fpregs(current, regs, fpu)))
1709                 fill_note(notes + numnote++,
1710                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1711 #ifdef ELF_CORE_COPY_XFPREGS
1712         if (elf_core_copy_task_xfpregs(current, xfpu))
1713                 fill_note(notes + numnote++,
1714                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1715 #endif
1716
1717         fs = get_fs();
1718         set_fs(KERNEL_DS);
1719
1720         DUMP_WRITE(elf, sizeof(*elf));
1721         offset += sizeof(*elf);                         /* Elf header */
1722         offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1723
1724         /* Write notes phdr entry */
1725         {
1726                 struct elf_phdr phdr;
1727                 int sz = 0;
1728
1729                 for (i = 0; i < numnote; i++)
1730                         sz += notesize(notes + i);
1731
1732                 sz += thread_status_size;
1733
1734                 fill_elf_note_phdr(&phdr, sz, offset);
1735                 offset += sz;
1736                 DUMP_WRITE(&phdr, sizeof(phdr));
1737         }
1738
1739         /* Page-align dumped data */
1740         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1741
1742         /*
1743          * We must use the same mm->flags while dumping core to avoid
1744          * inconsistency between the program headers and bodies, otherwise an
1745          * unusable core file can be generated.
1746          */
1747         mm_flags = current->mm->flags;
1748
1749         /* write program headers for segments dump */
1750         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1751                 struct elf_phdr phdr;
1752                 size_t sz;
1753
1754                 sz = vma->vm_end - vma->vm_start;
1755
1756                 phdr.p_type = PT_LOAD;
1757                 phdr.p_offset = offset;
1758                 phdr.p_vaddr = vma->vm_start;
1759                 phdr.p_paddr = 0;
1760                 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1761                 phdr.p_memsz = sz;
1762                 offset += phdr.p_filesz;
1763                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1764                 if (vma->vm_flags & VM_WRITE)
1765                         phdr.p_flags |= PF_W;
1766                 if (vma->vm_flags & VM_EXEC)
1767                         phdr.p_flags |= PF_X;
1768                 phdr.p_align = ELF_EXEC_PAGESIZE;
1769
1770                 DUMP_WRITE(&phdr, sizeof(phdr));
1771         }
1772
1773 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1774         ELF_CORE_WRITE_EXTRA_PHDRS;
1775 #endif
1776
1777         /* write out the notes section */
1778         for (i = 0; i < numnote; i++)
1779                 if (!writenote(notes + i, file))
1780                         goto end_coredump;
1781
1782         /* write out the thread status notes section */
1783         list_for_each(t, &thread_list) {
1784                 struct elf_thread_status *tmp =
1785                                 list_entry(t, struct elf_thread_status, list);
1786
1787                 for (i = 0; i < tmp->num_notes; i++)
1788                         if (!writenote(&tmp->notes[i], file))
1789                                 goto end_coredump;
1790         }
1791
1792         DUMP_SEEK(dataoff);
1793
1794         if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1795                 goto end_coredump;
1796
1797 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1798         ELF_CORE_WRITE_EXTRA_DATA;
1799 #endif
1800
1801         if (file->f_pos != offset) {
1802                 /* Sanity check */
1803                 printk(KERN_WARNING
1804                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1805                        file->f_pos, offset);
1806         }
1807
1808 end_coredump:
1809         set_fs(fs);
1810
1811 cleanup:
1812         while (!list_empty(&thread_list)) {
1813                 struct list_head *tmp = thread_list.next;
1814                 list_del(tmp);
1815                 kfree(list_entry(tmp, struct elf_thread_status, list));
1816         }
1817
1818         kfree(elf);
1819         kfree(prstatus);
1820         kfree(psinfo);
1821         kfree(notes);
1822         kfree(fpu);
1823 #ifdef ELF_CORE_COPY_XFPREGS
1824         kfree(xfpu);
1825 #endif
1826         return has_dumped;
1827 #undef NUM_NOTES
1828 }
1829
1830 #endif          /* USE_ELF_CORE_DUMP */