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 #include <linux/coredump.h>
  38
  39 #include <asm/uaccess.h>
  40 #include <asm/param.h>
  41 #include <asm/pgalloc.h>
  42
  43 typedef char *elf_caddr_t;
  44
  45 #if 0
  46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  47 #else
  48 #define kdebug(fmt, ...) do {} while(0)
  49 #endif
  50
  51 #if 0
  52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  53 #else
  54 #define kdcore(fmt, ...) do {} while(0)
  55 #endif
  56
  57 MODULE_LICENSE("GPL");
  58
  59 static int load_elf_fdpic_binary(struct linux_binprm *);
  60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  62                               struct mm_struct *, const char *);
  63
  64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  65                                    struct elf_fdpic_params *,
  66                                    struct elf_fdpic_params *);
  67
  68 #ifndef CONFIG_MMU
  69 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
  70                                             unsigned long *);
  71 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  72                                                    struct file *,
  73                                                    struct mm_struct *);
  74 #endif
  75
  76 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  77                                              struct file *, struct mm_struct *);
  78
  79 #ifdef CONFIG_ELF_CORE
  80 static int elf_fdpic_core_dump(struct coredump_params *cprm);
  81 #endif
  82
  83 static struct linux_binfmt elf_fdpic_format = {
  84         .module         = THIS_MODULE,
  85         .load_binary    = load_elf_fdpic_binary,
  86 #ifdef CONFIG_ELF_CORE
  87         .core_dump      = elf_fdpic_core_dump,
  88 #endif
  89         .min_coredump   = ELF_EXEC_PAGESIZE,
  90 };
  91
  92 static int __init init_elf_fdpic_binfmt(void)
  93 {
  94         register_binfmt(&elf_fdpic_format);
  95         return 0;
  96 }
  97
  98 static void __exit exit_elf_fdpic_binfmt(void)
  99 {
 100         unregister_binfmt(&elf_fdpic_format);
 101 }
 102
 103 core_initcall(init_elf_fdpic_binfmt);
 104 module_exit(exit_elf_fdpic_binfmt);
 105
 106 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
 107 {
 108         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 109                 return 0;
 110         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 111                 return 0;
 112         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
 113                 return 0;
 114         if (!file->f_op->mmap)
 115                 return 0;
 116         return 1;
 117 }
 118
 119 /*****************************************************************************/
 120 /*
 121  * read the program headers table into memory
 122  */
 123 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 124                                  struct file *file)
 125 {
 126         struct elf32_phdr *phdr;
 127         unsigned long size;
 128         int retval, loop;
 129
 130         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 131                 return -ENOMEM;
 132         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 133                 return -ENOMEM;
 134
 135         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 136         params->phdrs = kmalloc(size, GFP_KERNEL);
 137         if (!params->phdrs)
 138                 return -ENOMEM;
 139
 140         retval = kernel_read(file, params->hdr.e_phoff,
 141                              (char *) params->phdrs, size);
 142         if (unlikely(retval != size))
 143                 return retval < 0 ? retval : -ENOEXEC;
 144
 145         /* determine stack size for this binary */
 146         phdr = params->phdrs;
 147         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 148                 if (phdr->p_type != PT_GNU_STACK)
 149                         continue;
 150
 151                 if (phdr->p_flags & PF_X)
 152                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 153                 else
 154                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 155
 156                 params->stack_size = phdr->p_memsz;
 157                 break;
 158         }
 159
 160         return 0;
 161 }
 162
 163 /*****************************************************************************/
 164 /*
 165  * load an fdpic binary into various bits of memory
 166  */
 167 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
 168 {
 169         struct elf_fdpic_params exec_params, interp_params;
 170         struct pt_regs *regs = current_pt_regs();
 171         struct elf_phdr *phdr;
 172         unsigned long stack_size, entryaddr;
 173 #ifdef ELF_FDPIC_PLAT_INIT
 174         unsigned long dynaddr;
 175 #endif
 176 #ifndef CONFIG_MMU
 177         unsigned long stack_prot;
 178 #endif
 179         struct file *interpreter = NULL; /* to shut gcc up */
 180         char *interpreter_name = NULL;
 181         int executable_stack;
 182         int retval, i;
 183
 184         kdebug("____ LOAD %d ____", current->pid);
 185
 186         memset(&exec_params, 0, sizeof(exec_params));
 187         memset(&interp_params, 0, sizeof(interp_params));
 188
 189         exec_params.hdr = *(struct elfhdr *) bprm->buf;
 190         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 191
 192         /* check that this is a binary we know how to deal with */
 193         retval = -ENOEXEC;
 194         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
 195                 goto error;
 196
 197         /* read the program header table */
 198         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 199         if (retval < 0)
 200                 goto error;
 201
 202         /* scan for a program header that specifies an interpreter */
 203         phdr = exec_params.phdrs;
 204
 205         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 206                 switch (phdr->p_type) {
 207                 case PT_INTERP:
 208                         retval = -ENOMEM;
 209                         if (phdr->p_filesz > PATH_MAX)
 210                                 goto error;
 211                         retval = -ENOENT;
 212                         if (phdr->p_filesz < 2)
 213                                 goto error;
 214
 215                         /* read the name of the interpreter into memory */
 216                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 217                         if (!interpreter_name)
 218                                 goto error;
 219
 220                         retval = kernel_read(bprm->file,
 221                                              phdr->p_offset,
 222                                              interpreter_name,
 223                                              phdr->p_filesz);
 224                         if (unlikely(retval != phdr->p_filesz)) {
 225                                 if (retval >= 0)
 226                                         retval = -ENOEXEC;
 227                                 goto error;
 228                         }
 229
 230                         retval = -ENOENT;
 231                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
 232                                 goto error;
 233
 234                         kdebug("Using ELF interpreter %s", interpreter_name);
 235
 236                         /* replace the program with the interpreter */
 237                         interpreter = open_exec(interpreter_name);
 238                         retval = PTR_ERR(interpreter);
 239                         if (IS_ERR(interpreter)) {
 240                                 interpreter = NULL;
 241                                 goto error;
 242                         }
 243
 244                         /*
 245                          * If the binary is not readable then enforce
 246                          * mm->dumpable = 0 regardless of the interpreter's
 247                          * permissions.
 248                          */
 249                         would_dump(bprm, interpreter);
 250
 251                         retval = kernel_read(interpreter, 0, bprm->buf,
 252                                              BINPRM_BUF_SIZE);
 253                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
 254                                 if (retval >= 0)
 255                                         retval = -ENOEXEC;
 256                                 goto error;
 257                         }
 258
 259                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
 260                         break;
 261
 262                 case PT_LOAD:
 263 #ifdef CONFIG_MMU
 264                         if (exec_params.load_addr == 0)
 265                                 exec_params.load_addr = phdr->p_vaddr;
 266 #endif
 267                         break;
 268                 }
 269
 270         }
 271
 272         if (elf_check_const_displacement(&exec_params.hdr))
 273                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 274
 275         /* perform insanity checks on the interpreter */
 276         if (interpreter_name) {
 277                 retval = -ELIBBAD;
 278                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
 279                         goto error;
 280
 281                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 282
 283                 /* read the interpreter's program header table */
 284                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 285                 if (retval < 0)
 286                         goto error;
 287         }
 288
 289         stack_size = exec_params.stack_size;
 290         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 291                 executable_stack = EXSTACK_ENABLE_X;
 292         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 293                 executable_stack = EXSTACK_DISABLE_X;
 294         else
 295                 executable_stack = EXSTACK_DEFAULT;
 296
 297         if (stack_size == 0) {
 298                 stack_size = interp_params.stack_size;
 299                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 300                         executable_stack = EXSTACK_ENABLE_X;
 301                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 302                         executable_stack = EXSTACK_DISABLE_X;
 303                 else
 304                         executable_stack = EXSTACK_DEFAULT;
 305         }
 306
 307         retval = -ENOEXEC;
 308         if (stack_size == 0)
 309                 goto error;
 310
 311         if (elf_check_const_displacement(&interp_params.hdr))
 312                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 313
 314         /* flush all traces of the currently running executable */
 315         retval = flush_old_exec(bprm);
 316         if (retval)
 317                 goto error;
 318
 319         /* there's now no turning back... the old userspace image is dead,
 320          * defunct, deceased, etc. after this point we have to exit via
 321          * error_kill */
 322         set_personality(PER_LINUX_FDPIC);
 323         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
 324                 current->personality |= READ_IMPLIES_EXEC;
 325
 326         setup_new_exec(bprm);
 327
 328         set_binfmt(&elf_fdpic_format);
 329
 330         current->mm->start_code = 0;
 331         current->mm->end_code = 0;
 332         current->mm->start_stack = 0;
 333         current->mm->start_data = 0;
 334         current->mm->end_data = 0;
 335         current->mm->context.exec_fdpic_loadmap = 0;
 336         current->mm->context.interp_fdpic_loadmap = 0;
 337
 338 #ifdef CONFIG_MMU
 339         elf_fdpic_arch_lay_out_mm(&exec_params,
 340                                   &interp_params,
 341                                   &current->mm->start_stack,
 342                                   &current->mm->start_brk);
 343
 344         retval = setup_arg_pages(bprm, current->mm->start_stack,
 345                                  executable_stack);
 346         if (retval < 0) {
 347                 send_sig(SIGKILL, current, 0);
 348                 goto error_kill;
 349         }
 350 #endif
 351
 352         /* load the executable and interpreter into memory */
 353         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 354                                     "executable");
 355         if (retval < 0)
 356                 goto error_kill;
 357
 358         if (interpreter_name) {
 359                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 360                                             current->mm, "interpreter");
 361                 if (retval < 0) {
 362                         printk(KERN_ERR "Unable to load interpreter\n");
 363                         goto error_kill;
 364                 }
 365
 366                 allow_write_access(interpreter);
 367                 fput(interpreter);
 368                 interpreter = NULL;
 369         }
 370
 371 #ifdef CONFIG_MMU
 372         if (!current->mm->start_brk)
 373                 current->mm->start_brk = current->mm->end_data;
 374
 375         current->mm->brk = current->mm->start_brk =
 376                 PAGE_ALIGN(current->mm->start_brk);
 377
 378 #else
 379         /* create a stack and brk area big enough for everyone
 380          * - the brk heap starts at the bottom and works up
 381          * - the stack starts at the top and works down
 382          */
 383         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 384         if (stack_size < PAGE_SIZE * 2)
 385                 stack_size = PAGE_SIZE * 2;
 386
 387         stack_prot = PROT_READ | PROT_WRITE;
 388         if (executable_stack == EXSTACK_ENABLE_X ||
 389             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 390                 stack_prot |= PROT_EXEC;
 391
 392         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 393                                          MAP_PRIVATE | MAP_ANONYMOUS |
 394                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
 395                                          0);
 396
 397         if (IS_ERR_VALUE(current->mm->start_brk)) {
 398                 retval = current->mm->start_brk;
 399                 current->mm->start_brk = 0;
 400                 goto error_kill;
 401         }
 402
 403         current->mm->brk = current->mm->start_brk;
 404         current->mm->context.end_brk = current->mm->start_brk;
 405         current->mm->context.end_brk +=
 406                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 407         current->mm->start_stack = current->mm->start_brk + stack_size;
 408 #endif
 409
 410         install_exec_creds(bprm);
 411         if (create_elf_fdpic_tables(bprm, current->mm,
 412                                     &exec_params, &interp_params) < 0)
 413                 goto error_kill;
 414
 415         kdebug("- start_code  %lx", current->mm->start_code);
 416         kdebug("- end_code    %lx", current->mm->end_code);
 417         kdebug("- start_data  %lx", current->mm->start_data);
 418         kdebug("- end_data    %lx", current->mm->end_data);
 419         kdebug("- start_brk   %lx", current->mm->start_brk);
 420         kdebug("- brk         %lx", current->mm->brk);
 421         kdebug("- start_stack %lx", current->mm->start_stack);
 422
 423 #ifdef ELF_FDPIC_PLAT_INIT
 424         /*
 425          * The ABI may specify that certain registers be set up in special
 426          * ways (on i386 %edx is the address of a DT_FINI function, for
 427          * example.  This macro performs whatever initialization to
 428          * the regs structure is required.
 429          */
 430         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 431         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 432                             dynaddr);
 433 #endif
 434
 435         /* everything is now ready... get the userspace context ready to roll */
 436         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 437         start_thread(regs, entryaddr, current->mm->start_stack);
 438
 439         retval = 0;
 440
 441 error:
 442         if (interpreter) {
 443                 allow_write_access(interpreter);
 444                 fput(interpreter);
 445         }
 446         kfree(interpreter_name);
 447         kfree(exec_params.phdrs);
 448         kfree(exec_params.loadmap);
 449         kfree(interp_params.phdrs);
 450         kfree(interp_params.loadmap);
 451         return retval;
 452
 453         /* unrecoverable error - kill the process */
 454 error_kill:
 455         send_sig(SIGSEGV, current, 0);
 456         goto error;
 457
 458 }
 459
 460 /*****************************************************************************/
 461
 462 #ifndef ELF_BASE_PLATFORM
 463 /*
 464  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 465  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 466  * will be copied to the user stack in the same manner as AT_PLATFORM.
 467  */
 468 #define ELF_BASE_PLATFORM NULL
 469 #endif
 470
 471 /*
 472  * present useful information to the program by shovelling it onto the new
 473  * process's stack
 474  */
 475 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 476                                    struct mm_struct *mm,
 477                                    struct elf_fdpic_params *exec_params,
 478                                    struct elf_fdpic_params *interp_params)
 479 {
 480         const struct cred *cred = current_cred();
 481         unsigned long sp, csp, nitems;
 482         elf_caddr_t __user *argv, *envp;
 483         size_t platform_len = 0, len;
 484         char *k_platform, *k_base_platform;
 485         char __user *u_platform, *u_base_platform, *p;
 486         int loop;
 487         int nr; /* reset for each csp adjustment */
 488
 489 #ifdef CONFIG_MMU
 490         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 491          * by the processes running on the same package. One thing we can do is
 492          * to shuffle the initial stack for them, so we give the architecture
 493          * an opportunity to do so here.
 494          */
 495         sp = arch_align_stack(bprm->p);
 496 #else
 497         sp = mm->start_stack;
 498
 499         /* stack the program arguments and environment */
 500         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 501                 return -EFAULT;
 502 #endif
 503
 504         /*
 505          * If this architecture has a platform capability string, copy it
 506          * to userspace.  In some cases (Sparc), this info is impossible
 507          * for userspace to get any other way, in others (i386) it is
 508          * merely difficult.
 509          */
 510         k_platform = ELF_PLATFORM;
 511         u_platform = NULL;
 512
 513         if (k_platform) {
 514                 platform_len = strlen(k_platform) + 1;
 515                 sp -= platform_len;
 516                 u_platform = (char __user *) sp;
 517                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 518                         return -EFAULT;
 519         }
 520
 521         /*
 522          * If this architecture has a "base" platform capability
 523          * string, copy it to userspace.
 524          */
 525         k_base_platform = ELF_BASE_PLATFORM;
 526         u_base_platform = NULL;
 527
 528         if (k_base_platform) {
 529                 platform_len = strlen(k_base_platform) + 1;
 530                 sp -= platform_len;
 531                 u_base_platform = (char __user *) sp;
 532                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 533                         return -EFAULT;
 534         }
 535
 536         sp &= ~7UL;
 537
 538         /* stack the load map(s) */
 539         len = sizeof(struct elf32_fdpic_loadmap);
 540         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 541         sp = (sp - len) & ~7UL;
 542         exec_params->map_addr = sp;
 543
 544         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 545                 return -EFAULT;
 546
 547         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 548
 549         if (interp_params->loadmap) {
 550                 len = sizeof(struct elf32_fdpic_loadmap);
 551                 len += sizeof(struct elf32_fdpic_loadseg) *
 552                         interp_params->loadmap->nsegs;
 553                 sp = (sp - len) & ~7UL;
 554                 interp_params->map_addr = sp;
 555
 556                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 557                                  len) != 0)
 558                         return -EFAULT;
 559
 560                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 561         }
 562
 563         /* force 16 byte _final_ alignment here for generality */
 564 #define DLINFO_ITEMS 15
 565
 566         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 567                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 568
 569         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
 570                 nitems++;
 571
 572         csp = sp;
 573         sp -= nitems * 2 * sizeof(unsigned long);
 574         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 575         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 576         sp -= 1 * sizeof(unsigned long);                /* argc */
 577
 578         csp -= sp & 15UL;
 579         sp -= sp & 15UL;
 580
 581         /* put the ELF interpreter info on the stack */
 582 #define NEW_AUX_ENT(id, val)                                            \
 583         do {                                                            \
 584                 struct { unsigned long _id, _val; } __user *ent;        \
 585                                                                         \
 586                 ent = (void __user *) csp;                              \
 587                 __put_user((id), &ent[nr]._id);                         \
 588                 __put_user((val), &ent[nr]._val);                       \
 589                 nr++;                                                   \
 590         } while (0)
 591
 592         nr = 0;
 593         csp -= 2 * sizeof(unsigned long);
 594         NEW_AUX_ENT(AT_NULL, 0);
 595         if (k_platform) {
 596                 nr = 0;
 597                 csp -= 2 * sizeof(unsigned long);
 598                 NEW_AUX_ENT(AT_PLATFORM,
 599                             (elf_addr_t) (unsigned long) u_platform);
 600         }
 601
 602         if (k_base_platform) {
 603                 nr = 0;
 604                 csp -= 2 * sizeof(unsigned long);
 605                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 606                             (elf_addr_t) (unsigned long) u_base_platform);
 607         }
 608
 609         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 610                 nr = 0;
 611                 csp -= 2 * sizeof(unsigned long);
 612                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 613         }
 614
 615         nr = 0;
 616         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 617         NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 618 #ifdef ELF_HWCAP2
 619         NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 620 #endif
 621         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 622         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 623         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 624         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 625         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 626         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 627         NEW_AUX_ENT(AT_FLAGS,   0);
 628         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 629         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 630         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 631         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 632         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 633         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
 634         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 635
 636 #ifdef ARCH_DLINFO
 637         nr = 0;
 638         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 639
 640         /* ARCH_DLINFO must come last so platform specific code can enforce
 641          * special alignment requirements on the AUXV if necessary (eg. PPC).
 642          */
 643         ARCH_DLINFO;
 644 #endif
 645 #undef NEW_AUX_ENT
 646
 647         /* allocate room for argv[] and envv[] */
 648         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 649         envp = (elf_caddr_t __user *) csp;
 650         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 651         argv = (elf_caddr_t __user *) csp;
 652
 653         /* stack argc */
 654         csp -= sizeof(unsigned long);
 655         __put_user(bprm->argc, (unsigned long __user *) csp);
 656
 657         BUG_ON(csp != sp);
 658
 659         /* fill in the argv[] array */
 660 #ifdef CONFIG_MMU
 661         current->mm->arg_start = bprm->p;
 662 #else
 663         current->mm->arg_start = current->mm->start_stack -
 664                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 665 #endif
 666
 667         p = (char __user *) current->mm->arg_start;
 668         for (loop = bprm->argc; loop > 0; loop--) {
 669                 __put_user((elf_caddr_t) p, argv++);
 670                 len = strnlen_user(p, MAX_ARG_STRLEN);
 671                 if (!len || len > MAX_ARG_STRLEN)
 672                         return -EINVAL;
 673                 p += len;
 674         }
 675         __put_user(NULL, argv);
 676         current->mm->arg_end = (unsigned long) p;
 677
 678         /* fill in the envv[] array */
 679         current->mm->env_start = (unsigned long) p;
 680         for (loop = bprm->envc; loop > 0; loop--) {
 681                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 682                 len = strnlen_user(p, MAX_ARG_STRLEN);
 683                 if (!len || len > MAX_ARG_STRLEN)
 684                         return -EINVAL;
 685                 p += len;
 686         }
 687         __put_user(NULL, envp);
 688         current->mm->env_end = (unsigned long) p;
 689
 690         mm->start_stack = (unsigned long) sp;
 691         return 0;
 692 }
 693
 694 /*****************************************************************************/
 695 /*
 696  * transfer the program arguments and environment from the holding pages onto
 697  * the stack
 698  */
 699 #ifndef CONFIG_MMU
 700 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 701                                             unsigned long *_sp)
 702 {
 703         unsigned long index, stop, sp;
 704         char *src;
 705         int ret = 0;
 706
 707         stop = bprm->p >> PAGE_SHIFT;
 708         sp = *_sp;
 709
 710         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 711                 src = kmap(bprm->page[index]);
 712                 sp -= PAGE_SIZE;
 713                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 714                         ret = -EFAULT;
 715                 kunmap(bprm->page[index]);
 716                 if (ret < 0)
 717                         goto out;
 718         }
 719
 720         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 721
 722 out:
 723         return ret;
 724 }
 725 #endif
 726
 727 /*****************************************************************************/
 728 /*
 729  * load the appropriate binary image (executable or interpreter) into memory
 730  * - we assume no MMU is available
 731  * - if no other PIC bits are set in params->hdr->e_flags
 732  *   - we assume that the LOADable segments in the binary are independently relocatable
 733  *   - we assume R/O executable segments are shareable
 734  * - else
 735  *   - we assume the loadable parts of the image to require fixed displacement
 736  *   - the image is not shareable
 737  */
 738 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 739                               struct file *file,
 740                               struct mm_struct *mm,
 741                               const char *what)
 742 {
 743         struct elf32_fdpic_loadmap *loadmap;
 744 #ifdef CONFIG_MMU
 745         struct elf32_fdpic_loadseg *mseg;
 746 #endif
 747         struct elf32_fdpic_loadseg *seg;
 748         struct elf32_phdr *phdr;
 749         unsigned long load_addr, stop;
 750         unsigned nloads, tmp;
 751         size_t size;
 752         int loop, ret;
 753
 754         /* allocate a load map table */
 755         nloads = 0;
 756         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 757                 if (params->phdrs[loop].p_type == PT_LOAD)
 758                         nloads++;
 759
 760         if (nloads == 0)
 761                 return -ELIBBAD;
 762
 763         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 764         loadmap = kzalloc(size, GFP_KERNEL);
 765         if (!loadmap)
 766                 return -ENOMEM;
 767
 768         params->loadmap = loadmap;
 769
 770         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 771         loadmap->nsegs = nloads;
 772
 773         load_addr = params->load_addr;
 774         seg = loadmap->segs;
 775
 776         /* map the requested LOADs into the memory space */
 777         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 778         case ELF_FDPIC_FLAG_CONSTDISP:
 779         case ELF_FDPIC_FLAG_CONTIGUOUS:
 780 #ifndef CONFIG_MMU
 781                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 782                 if (ret < 0)
 783                         return ret;
 784                 break;
 785 #endif
 786         default:
 787                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 788                 if (ret < 0)
 789                         return ret;
 790                 break;
 791         }
 792
 793         /* map the entry point */
 794         if (params->hdr.e_entry) {
 795                 seg = loadmap->segs;
 796                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 797                         if (params->hdr.e_entry >= seg->p_vaddr &&
 798                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 799                                 params->entry_addr =
 800                                         (params->hdr.e_entry - seg->p_vaddr) +
 801                                         seg->addr;
 802                                 break;
 803                         }
 804                 }
 805         }
 806
 807         /* determine where the program header table has wound up if mapped */
 808         stop = params->hdr.e_phoff;
 809         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 810         phdr = params->phdrs;
 811
 812         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 813                 if (phdr->p_type != PT_LOAD)
 814                         continue;
 815
 816                 if (phdr->p_offset > params->hdr.e_phoff ||
 817                     phdr->p_offset + phdr->p_filesz < stop)
 818                         continue;
 819
 820                 seg = loadmap->segs;
 821                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 822                         if (phdr->p_vaddr >= seg->p_vaddr &&
 823                             phdr->p_vaddr + phdr->p_filesz <=
 824                             seg->p_vaddr + seg->p_memsz) {
 825                                 params->ph_addr =
 826                                         (phdr->p_vaddr - seg->p_vaddr) +
 827                                         seg->addr +
 828                                         params->hdr.e_phoff - phdr->p_offset;
 829                                 break;
 830                         }
 831                 }
 832                 break;
 833         }
 834
 835         /* determine where the dynamic section has wound up if there is one */
 836         phdr = params->phdrs;
 837         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 838                 if (phdr->p_type != PT_DYNAMIC)
 839                         continue;
 840
 841                 seg = loadmap->segs;
 842                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 843                         if (phdr->p_vaddr >= seg->p_vaddr &&
 844                             phdr->p_vaddr + phdr->p_memsz <=
 845                             seg->p_vaddr + seg->p_memsz) {
 846                                 params->dynamic_addr =
 847                                         (phdr->p_vaddr - seg->p_vaddr) +
 848                                         seg->addr;
 849
 850                                 /* check the dynamic section contains at least
 851                                  * one item, and that the last item is a NULL
 852                                  * entry */
 853                                 if (phdr->p_memsz == 0 ||
 854                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 855                                         goto dynamic_error;
 856
 857                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 858                                 if (((Elf32_Dyn *)
 859                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
 860                                         goto dynamic_error;
 861                                 break;
 862                         }
 863                 }
 864                 break;
 865         }
 866
 867         /* now elide adjacent segments in the load map on MMU linux
 868          * - on uClinux the holes between may actually be filled with system
 869          *   stuff or stuff from other processes
 870          */
 871 #ifdef CONFIG_MMU
 872         nloads = loadmap->nsegs;
 873         mseg = loadmap->segs;
 874         seg = mseg + 1;
 875         for (loop = 1; loop < nloads; loop++) {
 876                 /* see if we have a candidate for merging */
 877                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 878                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 879                         if (load_addr == (seg->addr & PAGE_MASK)) {
 880                                 mseg->p_memsz +=
 881                                         load_addr -
 882                                         (mseg->addr + mseg->p_memsz);
 883                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 884                                 mseg->p_memsz += seg->p_memsz;
 885                                 loadmap->nsegs--;
 886                                 continue;
 887                         }
 888                 }
 889
 890                 mseg++;
 891                 if (mseg != seg)
 892                         *mseg = *seg;
 893         }
 894 #endif
 895
 896         kdebug("Mapped Object [%s]:", what);
 897         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 898         kdebug("- entry    : %lx", params->entry_addr);
 899         kdebug("- PHDR[]   : %lx", params->ph_addr);
 900         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 901         seg = loadmap->segs;
 902         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 903                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 904                        loop,
 905                        seg->addr, seg->addr + seg->p_memsz - 1,
 906                        seg->p_vaddr, seg->p_memsz);
 907
 908         return 0;
 909
 910 dynamic_error:
 911         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 912                what, file_inode(file)->i_ino);
 913         return -ELIBBAD;
 914 }
 915
 916 /*****************************************************************************/
 917 /*
 918  * map a file with constant displacement under uClinux
 919  */
 920 #ifndef CONFIG_MMU
 921 static int elf_fdpic_map_file_constdisp_on_uclinux(
 922         struct elf_fdpic_params *params,
 923         struct file *file,
 924         struct mm_struct *mm)
 925 {
 926         struct elf32_fdpic_loadseg *seg;
 927         struct elf32_phdr *phdr;
 928         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 929         int loop, ret;
 930
 931         load_addr = params->load_addr;
 932         seg = params->loadmap->segs;
 933
 934         /* determine the bounds of the contiguous overall allocation we must
 935          * make */
 936         phdr = params->phdrs;
 937         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 938                 if (params->phdrs[loop].p_type != PT_LOAD)
 939                         continue;
 940
 941                 if (base > phdr->p_vaddr)
 942                         base = phdr->p_vaddr;
 943                 if (top < phdr->p_vaddr + phdr->p_memsz)
 944                         top = phdr->p_vaddr + phdr->p_memsz;
 945         }
 946
 947         /* allocate one big anon block for everything */
 948         mflags = MAP_PRIVATE;
 949         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 950                 mflags |= MAP_EXECUTABLE;
 951
 952         maddr = vm_mmap(NULL, load_addr, top - base,
 953                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 954         if (IS_ERR_VALUE(maddr))
 955                 return (int) maddr;
 956
 957         if (load_addr != 0)
 958                 load_addr += PAGE_ALIGN(top - base);
 959
 960         /* and then load the file segments into it */
 961         phdr = params->phdrs;
 962         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 963                 if (params->phdrs[loop].p_type != PT_LOAD)
 964                         continue;
 965
 966                 seg->addr = maddr + (phdr->p_vaddr - base);
 967                 seg->p_vaddr = phdr->p_vaddr;
 968                 seg->p_memsz = phdr->p_memsz;
 969
 970                 ret = read_code(file, seg->addr, phdr->p_offset,
 971                                        phdr->p_filesz);
 972                 if (ret < 0)
 973                         return ret;
 974
 975                 /* map the ELF header address if in this segment */
 976                 if (phdr->p_offset == 0)
 977                         params->elfhdr_addr = seg->addr;
 978
 979                 /* clear any space allocated but not loaded */
 980                 if (phdr->p_filesz < phdr->p_memsz) {
 981                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
 982                                        phdr->p_memsz - phdr->p_filesz))
 983                                 return -EFAULT;
 984                 }
 985
 986                 if (mm) {
 987                         if (phdr->p_flags & PF_X) {
 988                                 if (!mm->start_code) {
 989                                         mm->start_code = seg->addr;
 990                                         mm->end_code = seg->addr +
 991                                                 phdr->p_memsz;
 992                                 }
 993                         } else if (!mm->start_data) {
 994                                 mm->start_data = seg->addr;
 995                                 mm->end_data = seg->addr + phdr->p_memsz;
 996                         }
 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                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1090                                 phdr->p_offset - disp);
1091
1092                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1093                        loop, phdr->p_memsz + disp, prot, flags,
1094                        phdr->p_offset - disp, maddr);
1095
1096                 if (IS_ERR_VALUE(maddr))
1097                         return (int) maddr;
1098
1099                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1100                     ELF_FDPIC_FLAG_CONTIGUOUS)
1101                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1102
1103                 seg->addr = maddr + disp;
1104                 seg->p_vaddr = phdr->p_vaddr;
1105                 seg->p_memsz = phdr->p_memsz;
1106
1107                 /* map the ELF header address if in this segment */
1108                 if (phdr->p_offset == 0)
1109                         params->elfhdr_addr = seg->addr;
1110
1111                 /* clear the bit between beginning of mapping and beginning of
1112                  * PT_LOAD */
1113                 if (prot & PROT_WRITE && disp > 0) {
1114                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1115                         if (clear_user((void __user *) maddr, disp))
1116                                 return -EFAULT;
1117                         maddr += disp;
1118                 }
1119
1120                 /* clear any space allocated but not loaded
1121                  * - on uClinux we can just clear the lot
1122                  * - on MMU linux we'll get a SIGBUS beyond the last page
1123                  *   extant in the file
1124                  */
1125                 excess = phdr->p_memsz - phdr->p_filesz;
1126                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1127
1128 #ifdef CONFIG_MMU
1129                 if (excess > excess1) {
1130                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1131                         unsigned long xmaddr;
1132
1133                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1134                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1135                                          prot, flags, 0);
1136
1137                         kdebug("mmap[%d] <anon>"
1138                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1139                                loop, xaddr, excess - excess1, prot, flags,
1140                                xmaddr);
1141
1142                         if (xmaddr != xaddr)
1143                                 return -ENOMEM;
1144                 }
1145
1146                 if (prot & PROT_WRITE && excess1 > 0) {
1147                         kdebug("clear[%d] ad=%lx sz=%lx",
1148                                loop, maddr + phdr->p_filesz, excess1);
1149                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1150                                        excess1))
1151                                 return -EFAULT;
1152                 }
1153
1154 #else
1155                 if (excess > 0) {
1156                         kdebug("clear[%d] ad=%lx sz=%lx",
1157                                loop, maddr + phdr->p_filesz, excess);
1158                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1159                                 return -EFAULT;
1160                 }
1161 #endif
1162
1163                 if (mm) {
1164                         if (phdr->p_flags & PF_X) {
1165                                 if (!mm->start_code) {
1166                                         mm->start_code = maddr;
1167                                         mm->end_code = maddr + phdr->p_memsz;
1168                                 }
1169                         } else if (!mm->start_data) {
1170                                 mm->start_data = maddr;
1171                                 mm->end_data = maddr + phdr->p_memsz;
1172                         }
1173                 }
1174
1175                 seg++;
1176         }
1177
1178         return 0;
1179 }
1180
1181 /*****************************************************************************/
1182 /*
1183  * ELF-FDPIC core dumper
1184  *
1185  * Modelled on fs/exec.c:aout_core_dump()
1186  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1187  *
1188  * Modelled on fs/binfmt_elf.c core dumper
1189  */
1190 #ifdef CONFIG_ELF_CORE
1191
1192 /*
1193  * Decide whether a segment is worth dumping; default is yes to be
1194  * sure (missing info is worse than too much; etc).
1195  * Personally I'd include everything, and use the coredump limit...
1196  *
1197  * I think we should skip something. But I am not sure how. H.J.
1198  */
1199 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1200 {
1201         int dump_ok;
1202
1203         /* Do not dump I/O mapped devices or special mappings */
1204         if (vma->vm_flags & VM_IO) {
1205                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1206                 return 0;
1207         }
1208
1209         /* If we may not read the contents, don't allow us to dump
1210          * them either. "dump_write()" can't handle it anyway.
1211          */
1212         if (!(vma->vm_flags & VM_READ)) {
1213                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1214                 return 0;
1215         }
1216
1217         /* By default, dump shared memory if mapped from an anonymous file. */
1218         if (vma->vm_flags & VM_SHARED) {
1219                 if (file_inode(vma->vm_file)->i_nlink == 0) {
1220                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1221                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1222                                vma->vm_flags, dump_ok ? "yes" : "no");
1223                         return dump_ok;
1224                 }
1225
1226                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1227                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1228                        vma->vm_flags, dump_ok ? "yes" : "no");
1229                 return dump_ok;
1230         }
1231
1232 #ifdef CONFIG_MMU
1233         /* By default, if it hasn't been written to, don't write it out */
1234         if (!vma->anon_vma) {
1235                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1236                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1237                        vma->vm_flags, dump_ok ? "yes" : "no");
1238                 return dump_ok;
1239         }
1240 #endif
1241
1242         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1243         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1244                dump_ok ? "yes" : "no");
1245         return dump_ok;
1246 }
1247
1248 /* An ELF note in memory */
1249 struct memelfnote
1250 {
1251         const char *name;
1252         int type;
1253         unsigned int datasz;
1254         void *data;
1255 };
1256
1257 static int notesize(struct memelfnote *en)
1258 {
1259         int sz;
1260
1261         sz = sizeof(struct elf_note);
1262         sz += roundup(strlen(en->name) + 1, 4);
1263         sz += roundup(en->datasz, 4);
1264
1265         return sz;
1266 }
1267
1268 /* #define DEBUG */
1269
1270 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1271 {
1272         struct elf_note en;
1273         en.n_namesz = strlen(men->name) + 1;
1274         en.n_descsz = men->datasz;
1275         en.n_type = men->type;
1276
1277         return dump_emit(cprm, &en, sizeof(en)) &&
1278                 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1279                 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1280 }
1281
1282 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1283 {
1284         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1285         elf->e_ident[EI_CLASS] = ELF_CLASS;
1286         elf->e_ident[EI_DATA] = ELF_DATA;
1287         elf->e_ident[EI_VERSION] = EV_CURRENT;
1288         elf->e_ident[EI_OSABI] = ELF_OSABI;
1289         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1290
1291         elf->e_type = ET_CORE;
1292         elf->e_machine = ELF_ARCH;
1293         elf->e_version = EV_CURRENT;
1294         elf->e_entry = 0;
1295         elf->e_phoff = sizeof(struct elfhdr);
1296         elf->e_shoff = 0;
1297         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1298         elf->e_ehsize = sizeof(struct elfhdr);
1299         elf->e_phentsize = sizeof(struct elf_phdr);
1300         elf->e_phnum = segs;
1301         elf->e_shentsize = 0;
1302         elf->e_shnum = 0;
1303         elf->e_shstrndx = 0;
1304         return;
1305 }
1306
1307 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1308 {
1309         phdr->p_type = PT_NOTE;
1310         phdr->p_offset = offset;
1311         phdr->p_vaddr = 0;
1312         phdr->p_paddr = 0;
1313         phdr->p_filesz = sz;
1314         phdr->p_memsz = 0;
1315         phdr->p_flags = 0;
1316         phdr->p_align = 0;
1317         return;
1318 }
1319
1320 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1321                 unsigned int sz, void *data)
1322 {
1323         note->name = name;
1324         note->type = type;
1325         note->datasz = sz;
1326         note->data = data;
1327         return;
1328 }
1329
1330 /*
1331  * fill up all the fields in prstatus from the given task struct, except
1332  * registers which need to be filled up separately.
1333  */
1334 static void fill_prstatus(struct elf_prstatus *prstatus,
1335                           struct task_struct *p, long signr)
1336 {
1337         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1338         prstatus->pr_sigpend = p->pending.signal.sig[0];
1339         prstatus->pr_sighold = p->blocked.sig[0];
1340         rcu_read_lock();
1341         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1342         rcu_read_unlock();
1343         prstatus->pr_pid = task_pid_vnr(p);
1344         prstatus->pr_pgrp = task_pgrp_vnr(p);
1345         prstatus->pr_sid = task_session_vnr(p);
1346         if (thread_group_leader(p)) {
1347                 struct task_cputime cputime;
1348
1349                 /*
1350                  * This is the record for the group leader.  It shows the
1351                  * group-wide total, not its individual thread total.
1352                  */
1353                 thread_group_cputime(p, &cputime);
1354                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1355                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1356         } else {
1357                 cputime_t utime, stime;
1358
1359                 task_cputime(p, &utime, &stime);
1360                 cputime_to_timeval(utime, &prstatus->pr_utime);
1361                 cputime_to_timeval(stime, &prstatus->pr_stime);
1362         }
1363         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1364         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1365
1366         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1367         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1368 }
1369
1370 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1371                        struct mm_struct *mm)
1372 {
1373         const struct cred *cred;
1374         unsigned int i, len;
1375
1376         /* first copy the parameters from user space */
1377         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1378
1379         len = mm->arg_end - mm->arg_start;
1380         if (len >= ELF_PRARGSZ)
1381                 len = ELF_PRARGSZ - 1;
1382         if (copy_from_user(&psinfo->pr_psargs,
1383                            (const char __user *) mm->arg_start, len))
1384                 return -EFAULT;
1385         for (i = 0; i < len; i++)
1386                 if (psinfo->pr_psargs[i] == 0)
1387                         psinfo->pr_psargs[i] = ' ';
1388         psinfo->pr_psargs[len] = 0;
1389
1390         rcu_read_lock();
1391         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1392         rcu_read_unlock();
1393         psinfo->pr_pid = task_pid_vnr(p);
1394         psinfo->pr_pgrp = task_pgrp_vnr(p);
1395         psinfo->pr_sid = task_session_vnr(p);
1396
1397         i = p->state ? ffz(~p->state) + 1 : 0;
1398         psinfo->pr_state = i;
1399         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1400         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1401         psinfo->pr_nice = task_nice(p);
1402         psinfo->pr_flag = p->flags;
1403         rcu_read_lock();
1404         cred = __task_cred(p);
1405         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1406         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1407         rcu_read_unlock();
1408         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1409
1410         return 0;
1411 }
1412
1413 /* Here is the structure in which status of each thread is captured. */
1414 struct elf_thread_status
1415 {
1416         struct list_head list;
1417         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1418         elf_fpregset_t fpu;             /* NT_PRFPREG */
1419         struct task_struct *thread;
1420 #ifdef ELF_CORE_COPY_XFPREGS
1421         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1422 #endif
1423         struct memelfnote notes[3];
1424         int num_notes;
1425 };
1426
1427 /*
1428  * In order to add the specific thread information for the elf file format,
1429  * we need to keep a linked list of every thread's pr_status and then create
1430  * a single section for them in the final core file.
1431  */
1432 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1433 {
1434         struct task_struct *p = t->thread;
1435         int sz = 0;
1436
1437         t->num_notes = 0;
1438
1439         fill_prstatus(&t->prstatus, p, signr);
1440         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1441
1442         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1443                   &t->prstatus);
1444         t->num_notes++;
1445         sz += notesize(&t->notes[0]);
1446
1447         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1448         if (t->prstatus.pr_fpvalid) {
1449                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1450                           &t->fpu);
1451                 t->num_notes++;
1452                 sz += notesize(&t->notes[1]);
1453         }
1454
1455 #ifdef ELF_CORE_COPY_XFPREGS
1456         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1457                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1458                           sizeof(t->xfpu), &t->xfpu);
1459                 t->num_notes++;
1460                 sz += notesize(&t->notes[2]);
1461         }
1462 #endif
1463         return sz;
1464 }
1465
1466 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1467                              elf_addr_t e_shoff, int segs)
1468 {
1469         elf->e_shoff = e_shoff;
1470         elf->e_shentsize = sizeof(*shdr4extnum);
1471         elf->e_shnum = 1;
1472         elf->e_shstrndx = SHN_UNDEF;
1473
1474         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1475
1476         shdr4extnum->sh_type = SHT_NULL;
1477         shdr4extnum->sh_size = elf->e_shnum;
1478         shdr4extnum->sh_link = elf->e_shstrndx;
1479         shdr4extnum->sh_info = segs;
1480 }
1481
1482 /*
1483  * dump the segments for an MMU process
1484  */
1485 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1486 {
1487         struct vm_area_struct *vma;
1488
1489         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1490                 unsigned long addr;
1491
1492                 if (!maydump(vma, cprm->mm_flags))
1493                         continue;
1494
1495 #ifdef CONFIG_MMU
1496                 for (addr = vma->vm_start; addr < vma->vm_end;
1497                                                         addr += PAGE_SIZE) {
1498                         bool res;
1499                         struct page *page = get_dump_page(addr);
1500                         if (page) {
1501                                 void *kaddr = kmap(page);
1502                                 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1503                                 kunmap(page);
1504                                 page_cache_release(page);
1505                         } else {
1506                                 res = dump_skip(cprm, PAGE_SIZE);
1507                         }
1508                         if (!res)
1509                                 return false;
1510                 }
1511 #else
1512                 if (!dump_emit(cprm, (void *) vma->vm_start,
1513                                 vma->vm_end - vma->vm_start))
1514                         return false;
1515 #endif
1516         }
1517         return true;
1518 }
1519
1520 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1521 {
1522         struct vm_area_struct *vma;
1523         size_t size = 0;
1524
1525         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1526                 if (maydump(vma, mm_flags))
1527                         size += vma->vm_end - vma->vm_start;
1528         return size;
1529 }
1530
1531 /*
1532  * Actual dumper
1533  *
1534  * This is a two-pass process; first we find the offsets of the bits,
1535  * and then they are actually written out.  If we run out of core limit
1536  * we just truncate.
1537  */
1538 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1539 {
1540 #define NUM_NOTES       6
1541         int has_dumped = 0;
1542         mm_segment_t fs;
1543         int segs;
1544         int i;
1545         struct vm_area_struct *vma;
1546         struct elfhdr *elf = NULL;
1547         loff_t offset = 0, dataoff;
1548         int numnote;
1549         struct memelfnote *notes = NULL;
1550         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1551         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1552         LIST_HEAD(thread_list);
1553         struct list_head *t;
1554         elf_fpregset_t *fpu = NULL;
1555 #ifdef ELF_CORE_COPY_XFPREGS
1556         elf_fpxregset_t *xfpu = NULL;
1557 #endif
1558         int thread_status_size = 0;
1559         elf_addr_t *auxv;
1560         struct elf_phdr *phdr4note = NULL;
1561         struct elf_shdr *shdr4extnum = NULL;
1562         Elf_Half e_phnum;
1563         elf_addr_t e_shoff;
1564         struct core_thread *ct;
1565         struct elf_thread_status *tmp;
1566
1567         /*
1568          * We no longer stop all VM operations.
1569          *
1570          * This is because those proceses that could possibly change map_count
1571          * or the mmap / vma pages are now blocked in do_exit on current
1572          * finishing this core dump.
1573          *
1574          * Only ptrace can touch these memory addresses, but it doesn't change
1575          * the map_count or the pages allocated. So no possibility of crashing
1576          * exists while dumping the mm->vm_next areas to the core file.
1577          */
1578
1579         /* alloc memory for large data structures: too large to be on stack */
1580         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1581         if (!elf)
1582                 goto cleanup;
1583         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1584         if (!prstatus)
1585                 goto cleanup;
1586         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1587         if (!psinfo)
1588                 goto cleanup;
1589         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1590         if (!notes)
1591                 goto cleanup;
1592         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1593         if (!fpu)
1594                 goto cleanup;
1595 #ifdef ELF_CORE_COPY_XFPREGS
1596         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1597         if (!xfpu)
1598                 goto cleanup;
1599 #endif
1600
1601         for (ct = current->mm->core_state->dumper.next;
1602                                         ct; ct = ct->next) {
1603                 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1604                 if (!tmp)
1605                         goto cleanup;
1606
1607                 tmp->thread = ct->task;
1608                 list_add(&tmp->list, &thread_list);
1609         }
1610
1611         list_for_each(t, &thread_list) {
1612                 struct elf_thread_status *tmp;
1613                 int sz;
1614
1615                 tmp = list_entry(t, struct elf_thread_status, list);
1616                 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1617                 thread_status_size += sz;
1618         }
1619
1620         /* now collect the dump for the current */
1621         fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1622         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1623
1624         segs = current->mm->map_count;
1625         segs += elf_core_extra_phdrs();
1626
1627         /* for notes section */
1628         segs++;
1629
1630         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1631          * this, kernel supports extended numbering. Have a look at
1632          * include/linux/elf.h for further information. */
1633         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1634
1635         /* Set up header */
1636         fill_elf_fdpic_header(elf, e_phnum);
1637
1638         has_dumped = 1;
1639         /*
1640          * Set up the notes in similar form to SVR4 core dumps made
1641          * with info from their /proc.
1642          */
1643
1644         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1645         fill_psinfo(psinfo, current->group_leader, current->mm);
1646         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1647
1648         numnote = 2;
1649
1650         auxv = (elf_addr_t *) current->mm->saved_auxv;
1651
1652         i = 0;
1653         do
1654                 i += 2;
1655         while (auxv[i - 2] != AT_NULL);
1656         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1657                   i * sizeof(elf_addr_t), auxv);
1658
1659         /* Try to dump the FPU. */
1660         if ((prstatus->pr_fpvalid =
1661              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1662                 fill_note(notes + numnote++,
1663                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1664 #ifdef ELF_CORE_COPY_XFPREGS
1665         if (elf_core_copy_task_xfpregs(current, xfpu))
1666                 fill_note(notes + numnote++,
1667                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1668 #endif
1669
1670         fs = get_fs();
1671         set_fs(KERNEL_DS);
1672
1673         offset += sizeof(*elf);                         /* Elf header */
1674         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1675
1676         /* Write notes phdr entry */
1677         {
1678                 int sz = 0;
1679
1680                 for (i = 0; i < numnote; i++)
1681                         sz += notesize(notes + i);
1682
1683                 sz += thread_status_size;
1684
1685                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1686                 if (!phdr4note)
1687                         goto end_coredump;
1688
1689                 fill_elf_note_phdr(phdr4note, sz, offset);
1690                 offset += sz;
1691         }
1692
1693         /* Page-align dumped data */
1694         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1695
1696         offset += elf_core_vma_data_size(cprm->mm_flags);
1697         offset += elf_core_extra_data_size();
1698         e_shoff = offset;
1699
1700         if (e_phnum == PN_XNUM) {
1701                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1702                 if (!shdr4extnum)
1703                         goto end_coredump;
1704                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1705         }
1706
1707         offset = dataoff;
1708
1709         if (!dump_emit(cprm, elf, sizeof(*elf)))
1710                 goto end_coredump;
1711
1712         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1713                 goto end_coredump;
1714
1715         /* write program headers for segments dump */
1716         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1717                 struct elf_phdr phdr;
1718                 size_t sz;
1719
1720                 sz = vma->vm_end - vma->vm_start;
1721
1722                 phdr.p_type = PT_LOAD;
1723                 phdr.p_offset = offset;
1724                 phdr.p_vaddr = vma->vm_start;
1725                 phdr.p_paddr = 0;
1726                 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1727                 phdr.p_memsz = sz;
1728                 offset += phdr.p_filesz;
1729                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1730                 if (vma->vm_flags & VM_WRITE)
1731                         phdr.p_flags |= PF_W;
1732                 if (vma->vm_flags & VM_EXEC)
1733                         phdr.p_flags |= PF_X;
1734                 phdr.p_align = ELF_EXEC_PAGESIZE;
1735
1736                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1737                         goto end_coredump;
1738         }
1739
1740         if (!elf_core_write_extra_phdrs(cprm, offset))
1741                 goto end_coredump;
1742
1743         /* write out the notes section */
1744         for (i = 0; i < numnote; i++)
1745                 if (!writenote(notes + i, cprm))
1746                         goto end_coredump;
1747
1748         /* write out the thread status notes section */
1749         list_for_each(t, &thread_list) {
1750                 struct elf_thread_status *tmp =
1751                                 list_entry(t, struct elf_thread_status, list);
1752
1753                 for (i = 0; i < tmp->num_notes; i++)
1754                         if (!writenote(&tmp->notes[i], cprm))
1755                                 goto end_coredump;
1756         }
1757
1758         if (!dump_skip(cprm, dataoff - cprm->written))
1759                 goto end_coredump;
1760
1761         if (!elf_fdpic_dump_segments(cprm))
1762                 goto end_coredump;
1763
1764         if (!elf_core_write_extra_data(cprm))
1765                 goto end_coredump;
1766
1767         if (e_phnum == PN_XNUM) {
1768                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1769                         goto end_coredump;
1770         }
1771
1772         if (cprm->file->f_pos != offset) {
1773                 /* Sanity check */
1774                 printk(KERN_WARNING
1775                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1776                        cprm->file->f_pos, offset);
1777         }
1778
1779 end_coredump:
1780         set_fs(fs);
1781
1782 cleanup:
1783         while (!list_empty(&thread_list)) {
1784                 struct list_head *tmp = thread_list.next;
1785                 list_del(tmp);
1786                 kfree(list_entry(tmp, struct elf_thread_status, list));
1787         }
1788         kfree(phdr4note);
1789         kfree(elf);
1790         kfree(prstatus);
1791         kfree(psinfo);
1792         kfree(notes);
1793         kfree(fpu);
1794         kfree(shdr4extnum);
1795 #ifdef ELF_CORE_COPY_XFPREGS
1796         kfree(xfpu);
1797 #endif
1798         return has_dumped;
1799 #undef NUM_NOTES
1800 }
1801
1802 #endif          /* CONFIG_ELF_CORE */