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.
 321          */
 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                 goto error;
 348 #endif
 349
 350         /* load the executable and interpreter into memory */
 351         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 352                                     "executable");
 353         if (retval < 0)
 354                 goto error;
 355
 356         if (interpreter_name) {
 357                 retval = elf_fdpic_map_file(&interp_params, interpreter,
 358                                             current->mm, "interpreter");
 359                 if (retval < 0) {
 360                         printk(KERN_ERR "Unable to load interpreter\n");
 361                         goto error;
 362                 }
 363
 364                 allow_write_access(interpreter);
 365                 fput(interpreter);
 366                 interpreter = NULL;
 367         }
 368
 369 #ifdef CONFIG_MMU
 370         if (!current->mm->start_brk)
 371                 current->mm->start_brk = current->mm->end_data;
 372
 373         current->mm->brk = current->mm->start_brk =
 374                 PAGE_ALIGN(current->mm->start_brk);
 375
 376 #else
 377         /* create a stack and brk area big enough for everyone
 378          * - the brk heap starts at the bottom and works up
 379          * - the stack starts at the top and works down
 380          */
 381         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 382         if (stack_size < PAGE_SIZE * 2)
 383                 stack_size = PAGE_SIZE * 2;
 384
 385         stack_prot = PROT_READ | PROT_WRITE;
 386         if (executable_stack == EXSTACK_ENABLE_X ||
 387             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 388                 stack_prot |= PROT_EXEC;
 389
 390         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 391                                          MAP_PRIVATE | MAP_ANONYMOUS |
 392                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
 393                                          0);
 394
 395         if (IS_ERR_VALUE(current->mm->start_brk)) {
 396                 retval = current->mm->start_brk;
 397                 current->mm->start_brk = 0;
 398                 goto error;
 399         }
 400
 401         current->mm->brk = current->mm->start_brk;
 402         current->mm->context.end_brk = current->mm->start_brk;
 403         current->mm->context.end_brk +=
 404                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 405         current->mm->start_stack = current->mm->start_brk + stack_size;
 406 #endif
 407
 408         install_exec_creds(bprm);
 409         if (create_elf_fdpic_tables(bprm, current->mm,
 410                                     &exec_params, &interp_params) < 0)
 411                 goto error;
 412
 413         kdebug("- start_code  %lx", current->mm->start_code);
 414         kdebug("- end_code    %lx", current->mm->end_code);
 415         kdebug("- start_data  %lx", current->mm->start_data);
 416         kdebug("- end_data    %lx", current->mm->end_data);
 417         kdebug("- start_brk   %lx", current->mm->start_brk);
 418         kdebug("- brk         %lx", current->mm->brk);
 419         kdebug("- start_stack %lx", current->mm->start_stack);
 420
 421 #ifdef ELF_FDPIC_PLAT_INIT
 422         /*
 423          * The ABI may specify that certain registers be set up in special
 424          * ways (on i386 %edx is the address of a DT_FINI function, for
 425          * example.  This macro performs whatever initialization to
 426          * the regs structure is required.
 427          */
 428         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 429         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 430                             dynaddr);
 431 #endif
 432
 433         /* everything is now ready... get the userspace context ready to roll */
 434         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 435         start_thread(regs, entryaddr, current->mm->start_stack);
 436
 437         retval = 0;
 438
 439 error:
 440         if (interpreter) {
 441                 allow_write_access(interpreter);
 442                 fput(interpreter);
 443         }
 444         kfree(interpreter_name);
 445         kfree(exec_params.phdrs);
 446         kfree(exec_params.loadmap);
 447         kfree(interp_params.phdrs);
 448         kfree(interp_params.loadmap);
 449         return retval;
 450 }
 451
 452 /*****************************************************************************/
 453
 454 #ifndef ELF_BASE_PLATFORM
 455 /*
 456  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 457  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 458  * will be copied to the user stack in the same manner as AT_PLATFORM.
 459  */
 460 #define ELF_BASE_PLATFORM NULL
 461 #endif
 462
 463 /*
 464  * present useful information to the program by shovelling it onto the new
 465  * process's stack
 466  */
 467 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 468                                    struct mm_struct *mm,
 469                                    struct elf_fdpic_params *exec_params,
 470                                    struct elf_fdpic_params *interp_params)
 471 {
 472         const struct cred *cred = current_cred();
 473         unsigned long sp, csp, nitems;
 474         elf_caddr_t __user *argv, *envp;
 475         size_t platform_len = 0, len;
 476         char *k_platform, *k_base_platform;
 477         char __user *u_platform, *u_base_platform, *p;
 478         int loop;
 479         int nr; /* reset for each csp adjustment */
 480
 481 #ifdef CONFIG_MMU
 482         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 483          * by the processes running on the same package. One thing we can do is
 484          * to shuffle the initial stack for them, so we give the architecture
 485          * an opportunity to do so here.
 486          */
 487         sp = arch_align_stack(bprm->p);
 488 #else
 489         sp = mm->start_stack;
 490
 491         /* stack the program arguments and environment */
 492         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 493                 return -EFAULT;
 494 #endif
 495
 496         /*
 497          * If this architecture has a platform capability string, copy it
 498          * to userspace.  In some cases (Sparc), this info is impossible
 499          * for userspace to get any other way, in others (i386) it is
 500          * merely difficult.
 501          */
 502         k_platform = ELF_PLATFORM;
 503         u_platform = NULL;
 504
 505         if (k_platform) {
 506                 platform_len = strlen(k_platform) + 1;
 507                 sp -= platform_len;
 508                 u_platform = (char __user *) sp;
 509                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 510                         return -EFAULT;
 511         }
 512
 513         /*
 514          * If this architecture has a "base" platform capability
 515          * string, copy it to userspace.
 516          */
 517         k_base_platform = ELF_BASE_PLATFORM;
 518         u_base_platform = NULL;
 519
 520         if (k_base_platform) {
 521                 platform_len = strlen(k_base_platform) + 1;
 522                 sp -= platform_len;
 523                 u_base_platform = (char __user *) sp;
 524                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 525                         return -EFAULT;
 526         }
 527
 528         sp &= ~7UL;
 529
 530         /* stack the load map(s) */
 531         len = sizeof(struct elf32_fdpic_loadmap);
 532         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 533         sp = (sp - len) & ~7UL;
 534         exec_params->map_addr = sp;
 535
 536         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 537                 return -EFAULT;
 538
 539         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 540
 541         if (interp_params->loadmap) {
 542                 len = sizeof(struct elf32_fdpic_loadmap);
 543                 len += sizeof(struct elf32_fdpic_loadseg) *
 544                         interp_params->loadmap->nsegs;
 545                 sp = (sp - len) & ~7UL;
 546                 interp_params->map_addr = sp;
 547
 548                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
 549                                  len) != 0)
 550                         return -EFAULT;
 551
 552                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 553         }
 554
 555         /* force 16 byte _final_ alignment here for generality */
 556 #define DLINFO_ITEMS 15
 557
 558         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 559                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 560
 561         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
 562                 nitems++;
 563
 564         csp = sp;
 565         sp -= nitems * 2 * sizeof(unsigned long);
 566         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 567         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 568         sp -= 1 * sizeof(unsigned long);                /* argc */
 569
 570         csp -= sp & 15UL;
 571         sp -= sp & 15UL;
 572
 573         /* put the ELF interpreter info on the stack */
 574 #define NEW_AUX_ENT(id, val)                                            \
 575         do {                                                            \
 576                 struct { unsigned long _id, _val; } __user *ent;        \
 577                                                                         \
 578                 ent = (void __user *) csp;                              \
 579                 __put_user((id), &ent[nr]._id);                         \
 580                 __put_user((val), &ent[nr]._val);                       \
 581                 nr++;                                                   \
 582         } while (0)
 583
 584         nr = 0;
 585         csp -= 2 * sizeof(unsigned long);
 586         NEW_AUX_ENT(AT_NULL, 0);
 587         if (k_platform) {
 588                 nr = 0;
 589                 csp -= 2 * sizeof(unsigned long);
 590                 NEW_AUX_ENT(AT_PLATFORM,
 591                             (elf_addr_t) (unsigned long) u_platform);
 592         }
 593
 594         if (k_base_platform) {
 595                 nr = 0;
 596                 csp -= 2 * sizeof(unsigned long);
 597                 NEW_AUX_ENT(AT_BASE_PLATFORM,
 598                             (elf_addr_t) (unsigned long) u_base_platform);
 599         }
 600
 601         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 602                 nr = 0;
 603                 csp -= 2 * sizeof(unsigned long);
 604                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 605         }
 606
 607         nr = 0;
 608         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 609         NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 610 #ifdef ELF_HWCAP2
 611         NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 612 #endif
 613         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 614         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 615         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 616         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 617         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 618         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 619         NEW_AUX_ENT(AT_FLAGS,   0);
 620         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 621         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 622         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 623         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 624         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 625         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
 626         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 627
 628 #ifdef ARCH_DLINFO
 629         nr = 0;
 630         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 631
 632         /* ARCH_DLINFO must come last so platform specific code can enforce
 633          * special alignment requirements on the AUXV if necessary (eg. PPC).
 634          */
 635         ARCH_DLINFO;
 636 #endif
 637 #undef NEW_AUX_ENT
 638
 639         /* allocate room for argv[] and envv[] */
 640         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 641         envp = (elf_caddr_t __user *) csp;
 642         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 643         argv = (elf_caddr_t __user *) csp;
 644
 645         /* stack argc */
 646         csp -= sizeof(unsigned long);
 647         __put_user(bprm->argc, (unsigned long __user *) csp);
 648
 649         BUG_ON(csp != sp);
 650
 651         /* fill in the argv[] array */
 652 #ifdef CONFIG_MMU
 653         current->mm->arg_start = bprm->p;
 654 #else
 655         current->mm->arg_start = current->mm->start_stack -
 656                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 657 #endif
 658
 659         p = (char __user *) current->mm->arg_start;
 660         for (loop = bprm->argc; loop > 0; loop--) {
 661                 __put_user((elf_caddr_t) p, argv++);
 662                 len = strnlen_user(p, MAX_ARG_STRLEN);
 663                 if (!len || len > MAX_ARG_STRLEN)
 664                         return -EINVAL;
 665                 p += len;
 666         }
 667         __put_user(NULL, argv);
 668         current->mm->arg_end = (unsigned long) p;
 669
 670         /* fill in the envv[] array */
 671         current->mm->env_start = (unsigned long) p;
 672         for (loop = bprm->envc; loop > 0; loop--) {
 673                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
 674                 len = strnlen_user(p, MAX_ARG_STRLEN);
 675                 if (!len || len > MAX_ARG_STRLEN)
 676                         return -EINVAL;
 677                 p += len;
 678         }
 679         __put_user(NULL, envp);
 680         current->mm->env_end = (unsigned long) p;
 681
 682         mm->start_stack = (unsigned long) sp;
 683         return 0;
 684 }
 685
 686 /*****************************************************************************/
 687 /*
 688  * transfer the program arguments and environment from the holding pages onto
 689  * the stack
 690  */
 691 #ifndef CONFIG_MMU
 692 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 693                                             unsigned long *_sp)
 694 {
 695         unsigned long index, stop, sp;
 696         char *src;
 697         int ret = 0;
 698
 699         stop = bprm->p >> PAGE_SHIFT;
 700         sp = *_sp;
 701
 702         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 703                 src = kmap(bprm->page[index]);
 704                 sp -= PAGE_SIZE;
 705                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 706                         ret = -EFAULT;
 707                 kunmap(bprm->page[index]);
 708                 if (ret < 0)
 709                         goto out;
 710         }
 711
 712         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 713
 714 out:
 715         return ret;
 716 }
 717 #endif
 718
 719 /*****************************************************************************/
 720 /*
 721  * load the appropriate binary image (executable or interpreter) into memory
 722  * - we assume no MMU is available
 723  * - if no other PIC bits are set in params->hdr->e_flags
 724  *   - we assume that the LOADable segments in the binary are independently relocatable
 725  *   - we assume R/O executable segments are shareable
 726  * - else
 727  *   - we assume the loadable parts of the image to require fixed displacement
 728  *   - the image is not shareable
 729  */
 730 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 731                               struct file *file,
 732                               struct mm_struct *mm,
 733                               const char *what)
 734 {
 735         struct elf32_fdpic_loadmap *loadmap;
 736 #ifdef CONFIG_MMU
 737         struct elf32_fdpic_loadseg *mseg;
 738 #endif
 739         struct elf32_fdpic_loadseg *seg;
 740         struct elf32_phdr *phdr;
 741         unsigned long load_addr, stop;
 742         unsigned nloads, tmp;
 743         size_t size;
 744         int loop, ret;
 745
 746         /* allocate a load map table */
 747         nloads = 0;
 748         for (loop = 0; loop < params->hdr.e_phnum; loop++)
 749                 if (params->phdrs[loop].p_type == PT_LOAD)
 750                         nloads++;
 751
 752         if (nloads == 0)
 753                 return -ELIBBAD;
 754
 755         size = sizeof(*loadmap) + nloads * sizeof(*seg);
 756         loadmap = kzalloc(size, GFP_KERNEL);
 757         if (!loadmap)
 758                 return -ENOMEM;
 759
 760         params->loadmap = loadmap;
 761
 762         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 763         loadmap->nsegs = nloads;
 764
 765         load_addr = params->load_addr;
 766         seg = loadmap->segs;
 767
 768         /* map the requested LOADs into the memory space */
 769         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 770         case ELF_FDPIC_FLAG_CONSTDISP:
 771         case ELF_FDPIC_FLAG_CONTIGUOUS:
 772 #ifndef CONFIG_MMU
 773                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 774                 if (ret < 0)
 775                         return ret;
 776                 break;
 777 #endif
 778         default:
 779                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 780                 if (ret < 0)
 781                         return ret;
 782                 break;
 783         }
 784
 785         /* map the entry point */
 786         if (params->hdr.e_entry) {
 787                 seg = loadmap->segs;
 788                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 789                         if (params->hdr.e_entry >= seg->p_vaddr &&
 790                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 791                                 params->entry_addr =
 792                                         (params->hdr.e_entry - seg->p_vaddr) +
 793                                         seg->addr;
 794                                 break;
 795                         }
 796                 }
 797         }
 798
 799         /* determine where the program header table has wound up if mapped */
 800         stop = params->hdr.e_phoff;
 801         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 802         phdr = params->phdrs;
 803
 804         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 805                 if (phdr->p_type != PT_LOAD)
 806                         continue;
 807
 808                 if (phdr->p_offset > params->hdr.e_phoff ||
 809                     phdr->p_offset + phdr->p_filesz < stop)
 810                         continue;
 811
 812                 seg = loadmap->segs;
 813                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 814                         if (phdr->p_vaddr >= seg->p_vaddr &&
 815                             phdr->p_vaddr + phdr->p_filesz <=
 816                             seg->p_vaddr + seg->p_memsz) {
 817                                 params->ph_addr =
 818                                         (phdr->p_vaddr - seg->p_vaddr) +
 819                                         seg->addr +
 820                                         params->hdr.e_phoff - phdr->p_offset;
 821                                 break;
 822                         }
 823                 }
 824                 break;
 825         }
 826
 827         /* determine where the dynamic section has wound up if there is one */
 828         phdr = params->phdrs;
 829         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 830                 if (phdr->p_type != PT_DYNAMIC)
 831                         continue;
 832
 833                 seg = loadmap->segs;
 834                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 835                         if (phdr->p_vaddr >= seg->p_vaddr &&
 836                             phdr->p_vaddr + phdr->p_memsz <=
 837                             seg->p_vaddr + seg->p_memsz) {
 838                                 params->dynamic_addr =
 839                                         (phdr->p_vaddr - seg->p_vaddr) +
 840                                         seg->addr;
 841
 842                                 /* check the dynamic section contains at least
 843                                  * one item, and that the last item is a NULL
 844                                  * entry */
 845                                 if (phdr->p_memsz == 0 ||
 846                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 847                                         goto dynamic_error;
 848
 849                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 850                                 if (((Elf32_Dyn *)
 851                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
 852                                         goto dynamic_error;
 853                                 break;
 854                         }
 855                 }
 856                 break;
 857         }
 858
 859         /* now elide adjacent segments in the load map on MMU linux
 860          * - on uClinux the holes between may actually be filled with system
 861          *   stuff or stuff from other processes
 862          */
 863 #ifdef CONFIG_MMU
 864         nloads = loadmap->nsegs;
 865         mseg = loadmap->segs;
 866         seg = mseg + 1;
 867         for (loop = 1; loop < nloads; loop++) {
 868                 /* see if we have a candidate for merging */
 869                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 870                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 871                         if (load_addr == (seg->addr & PAGE_MASK)) {
 872                                 mseg->p_memsz +=
 873                                         load_addr -
 874                                         (mseg->addr + mseg->p_memsz);
 875                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
 876                                 mseg->p_memsz += seg->p_memsz;
 877                                 loadmap->nsegs--;
 878                                 continue;
 879                         }
 880                 }
 881
 882                 mseg++;
 883                 if (mseg != seg)
 884                         *mseg = *seg;
 885         }
 886 #endif
 887
 888         kdebug("Mapped Object [%s]:", what);
 889         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 890         kdebug("- entry    : %lx", params->entry_addr);
 891         kdebug("- PHDR[]   : %lx", params->ph_addr);
 892         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 893         seg = loadmap->segs;
 894         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 895                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 896                        loop,
 897                        seg->addr, seg->addr + seg->p_memsz - 1,
 898                        seg->p_vaddr, seg->p_memsz);
 899
 900         return 0;
 901
 902 dynamic_error:
 903         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 904                what, file_inode(file)->i_ino);
 905         return -ELIBBAD;
 906 }
 907
 908 /*****************************************************************************/
 909 /*
 910  * map a file with constant displacement under uClinux
 911  */
 912 #ifndef CONFIG_MMU
 913 static int elf_fdpic_map_file_constdisp_on_uclinux(
 914         struct elf_fdpic_params *params,
 915         struct file *file,
 916         struct mm_struct *mm)
 917 {
 918         struct elf32_fdpic_loadseg *seg;
 919         struct elf32_phdr *phdr;
 920         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 921         int loop, ret;
 922
 923         load_addr = params->load_addr;
 924         seg = params->loadmap->segs;
 925
 926         /* determine the bounds of the contiguous overall allocation we must
 927          * make */
 928         phdr = params->phdrs;
 929         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 930                 if (params->phdrs[loop].p_type != PT_LOAD)
 931                         continue;
 932
 933                 if (base > phdr->p_vaddr)
 934                         base = phdr->p_vaddr;
 935                 if (top < phdr->p_vaddr + phdr->p_memsz)
 936                         top = phdr->p_vaddr + phdr->p_memsz;
 937         }
 938
 939         /* allocate one big anon block for everything */
 940         mflags = MAP_PRIVATE;
 941         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 942                 mflags |= MAP_EXECUTABLE;
 943
 944         maddr = vm_mmap(NULL, load_addr, top - base,
 945                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 946         if (IS_ERR_VALUE(maddr))
 947                 return (int) maddr;
 948
 949         if (load_addr != 0)
 950                 load_addr += PAGE_ALIGN(top - base);
 951
 952         /* and then load the file segments into it */
 953         phdr = params->phdrs;
 954         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 955                 if (params->phdrs[loop].p_type != PT_LOAD)
 956                         continue;
 957
 958                 seg->addr = maddr + (phdr->p_vaddr - base);
 959                 seg->p_vaddr = phdr->p_vaddr;
 960                 seg->p_memsz = phdr->p_memsz;
 961
 962                 ret = read_code(file, seg->addr, phdr->p_offset,
 963                                        phdr->p_filesz);
 964                 if (ret < 0)
 965                         return ret;
 966
 967                 /* map the ELF header address if in this segment */
 968                 if (phdr->p_offset == 0)
 969                         params->elfhdr_addr = seg->addr;
 970
 971                 /* clear any space allocated but not loaded */
 972                 if (phdr->p_filesz < phdr->p_memsz) {
 973                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
 974                                        phdr->p_memsz - phdr->p_filesz))
 975                                 return -EFAULT;
 976                 }
 977
 978                 if (mm) {
 979                         if (phdr->p_flags & PF_X) {
 980                                 if (!mm->start_code) {
 981                                         mm->start_code = seg->addr;
 982                                         mm->end_code = seg->addr +
 983                                                 phdr->p_memsz;
 984                                 }
 985                         } else if (!mm->start_data) {
 986                                 mm->start_data = seg->addr;
 987                                 mm->end_data = seg->addr + phdr->p_memsz;
 988                         }
 989                 }
 990
 991                 seg++;
 992         }
 993
 994         return 0;
 995 }
 996 #endif
 997
 998 /*****************************************************************************/
 999 /*
1000  * map a binary by direct mmap() of the individual PT_LOAD segments
1001  */
1002 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1003                                              struct file *file,
1004                                              struct mm_struct *mm)
1005 {
1006         struct elf32_fdpic_loadseg *seg;
1007         struct elf32_phdr *phdr;
1008         unsigned long load_addr, delta_vaddr;
1009         int loop, dvset;
1010
1011         load_addr = params->load_addr;
1012         delta_vaddr = 0;
1013         dvset = 0;
1014
1015         seg = params->loadmap->segs;
1016
1017         /* deal with each load segment separately */
1018         phdr = params->phdrs;
1019         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1020                 unsigned long maddr, disp, excess, excess1;
1021                 int prot = 0, flags;
1022
1023                 if (phdr->p_type != PT_LOAD)
1024                         continue;
1025
1026                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1027                        (unsigned long) phdr->p_vaddr,
1028                        (unsigned long) phdr->p_offset,
1029                        (unsigned long) phdr->p_filesz,
1030                        (unsigned long) phdr->p_memsz);
1031
1032                 /* determine the mapping parameters */
1033                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1034                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1035                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1036
1037                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1038                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1039                         flags |= MAP_EXECUTABLE;
1040
1041                 maddr = 0;
1042
1043                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1044                 case ELF_FDPIC_FLAG_INDEPENDENT:
1045                         /* PT_LOADs are independently locatable */
1046                         break;
1047
1048                 case ELF_FDPIC_FLAG_HONOURVADDR:
1049                         /* the specified virtual address must be honoured */
1050                         maddr = phdr->p_vaddr;
1051                         flags |= MAP_FIXED;
1052                         break;
1053
1054                 case ELF_FDPIC_FLAG_CONSTDISP:
1055                         /* constant displacement
1056                          * - can be mapped anywhere, but must be mapped as a
1057                          *   unit
1058                          */
1059                         if (!dvset) {
1060                                 maddr = load_addr;
1061                                 delta_vaddr = phdr->p_vaddr;
1062                                 dvset = 1;
1063                         } else {
1064                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1065                                 flags |= MAP_FIXED;
1066                         }
1067                         break;
1068
1069                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1070                         /* contiguity handled later */
1071                         break;
1072
1073                 default:
1074                         BUG();
1075                 }
1076
1077                 maddr &= PAGE_MASK;
1078
1079                 /* create the mapping */
1080                 disp = phdr->p_vaddr & ~PAGE_MASK;
1081                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1082                                 phdr->p_offset - disp);
1083
1084                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1085                        loop, phdr->p_memsz + disp, prot, flags,
1086                        phdr->p_offset - disp, maddr);
1087
1088                 if (IS_ERR_VALUE(maddr))
1089                         return (int) maddr;
1090
1091                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1092                     ELF_FDPIC_FLAG_CONTIGUOUS)
1093                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1094
1095                 seg->addr = maddr + disp;
1096                 seg->p_vaddr = phdr->p_vaddr;
1097                 seg->p_memsz = phdr->p_memsz;
1098
1099                 /* map the ELF header address if in this segment */
1100                 if (phdr->p_offset == 0)
1101                         params->elfhdr_addr = seg->addr;
1102
1103                 /* clear the bit between beginning of mapping and beginning of
1104                  * PT_LOAD */
1105                 if (prot & PROT_WRITE && disp > 0) {
1106                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1107                         if (clear_user((void __user *) maddr, disp))
1108                                 return -EFAULT;
1109                         maddr += disp;
1110                 }
1111
1112                 /* clear any space allocated but not loaded
1113                  * - on uClinux we can just clear the lot
1114                  * - on MMU linux we'll get a SIGBUS beyond the last page
1115                  *   extant in the file
1116                  */
1117                 excess = phdr->p_memsz - phdr->p_filesz;
1118                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1119
1120 #ifdef CONFIG_MMU
1121                 if (excess > excess1) {
1122                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1123                         unsigned long xmaddr;
1124
1125                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1126                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1127                                          prot, flags, 0);
1128
1129                         kdebug("mmap[%d] <anon>"
1130                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1131                                loop, xaddr, excess - excess1, prot, flags,
1132                                xmaddr);
1133
1134                         if (xmaddr != xaddr)
1135                                 return -ENOMEM;
1136                 }
1137
1138                 if (prot & PROT_WRITE && excess1 > 0) {
1139                         kdebug("clear[%d] ad=%lx sz=%lx",
1140                                loop, maddr + phdr->p_filesz, excess1);
1141                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1142                                        excess1))
1143                                 return -EFAULT;
1144                 }
1145
1146 #else
1147                 if (excess > 0) {
1148                         kdebug("clear[%d] ad=%lx sz=%lx",
1149                                loop, maddr + phdr->p_filesz, excess);
1150                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1151                                 return -EFAULT;
1152                 }
1153 #endif
1154
1155                 if (mm) {
1156                         if (phdr->p_flags & PF_X) {
1157                                 if (!mm->start_code) {
1158                                         mm->start_code = maddr;
1159                                         mm->end_code = maddr + phdr->p_memsz;
1160                                 }
1161                         } else if (!mm->start_data) {
1162                                 mm->start_data = maddr;
1163                                 mm->end_data = maddr + phdr->p_memsz;
1164                         }
1165                 }
1166
1167                 seg++;
1168         }
1169
1170         return 0;
1171 }
1172
1173 /*****************************************************************************/
1174 /*
1175  * ELF-FDPIC core dumper
1176  *
1177  * Modelled on fs/exec.c:aout_core_dump()
1178  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1179  *
1180  * Modelled on fs/binfmt_elf.c core dumper
1181  */
1182 #ifdef CONFIG_ELF_CORE
1183
1184 /*
1185  * Decide whether a segment is worth dumping; default is yes to be
1186  * sure (missing info is worse than too much; etc).
1187  * Personally I'd include everything, and use the coredump limit...
1188  *
1189  * I think we should skip something. But I am not sure how. H.J.
1190  */
1191 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1192 {
1193         int dump_ok;
1194
1195         /* Do not dump I/O mapped devices or special mappings */
1196         if (vma->vm_flags & VM_IO) {
1197                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1198                 return 0;
1199         }
1200
1201         /* If we may not read the contents, don't allow us to dump
1202          * them either. "dump_write()" can't handle it anyway.
1203          */
1204         if (!(vma->vm_flags & VM_READ)) {
1205                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1206                 return 0;
1207         }
1208
1209         /* By default, dump shared memory if mapped from an anonymous file. */
1210         if (vma->vm_flags & VM_SHARED) {
1211                 if (file_inode(vma->vm_file)->i_nlink == 0) {
1212                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1213                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1214                                vma->vm_flags, dump_ok ? "yes" : "no");
1215                         return dump_ok;
1216                 }
1217
1218                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1219                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1220                        vma->vm_flags, dump_ok ? "yes" : "no");
1221                 return dump_ok;
1222         }
1223
1224 #ifdef CONFIG_MMU
1225         /* By default, if it hasn't been written to, don't write it out */
1226         if (!vma->anon_vma) {
1227                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1228                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1229                        vma->vm_flags, dump_ok ? "yes" : "no");
1230                 return dump_ok;
1231         }
1232 #endif
1233
1234         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1235         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1236                dump_ok ? "yes" : "no");
1237         return dump_ok;
1238 }
1239
1240 /* An ELF note in memory */
1241 struct memelfnote
1242 {
1243         const char *name;
1244         int type;
1245         unsigned int datasz;
1246         void *data;
1247 };
1248
1249 static int notesize(struct memelfnote *en)
1250 {
1251         int sz;
1252
1253         sz = sizeof(struct elf_note);
1254         sz += roundup(strlen(en->name) + 1, 4);
1255         sz += roundup(en->datasz, 4);
1256
1257         return sz;
1258 }
1259
1260 /* #define DEBUG */
1261
1262 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1263 {
1264         struct elf_note en;
1265         en.n_namesz = strlen(men->name) + 1;
1266         en.n_descsz = men->datasz;
1267         en.n_type = men->type;
1268
1269         return dump_emit(cprm, &en, sizeof(en)) &&
1270                 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1271                 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1272 }
1273
1274 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1275 {
1276         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1277         elf->e_ident[EI_CLASS] = ELF_CLASS;
1278         elf->e_ident[EI_DATA] = ELF_DATA;
1279         elf->e_ident[EI_VERSION] = EV_CURRENT;
1280         elf->e_ident[EI_OSABI] = ELF_OSABI;
1281         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1282
1283         elf->e_type = ET_CORE;
1284         elf->e_machine = ELF_ARCH;
1285         elf->e_version = EV_CURRENT;
1286         elf->e_entry = 0;
1287         elf->e_phoff = sizeof(struct elfhdr);
1288         elf->e_shoff = 0;
1289         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1290         elf->e_ehsize = sizeof(struct elfhdr);
1291         elf->e_phentsize = sizeof(struct elf_phdr);
1292         elf->e_phnum = segs;
1293         elf->e_shentsize = 0;
1294         elf->e_shnum = 0;
1295         elf->e_shstrndx = 0;
1296         return;
1297 }
1298
1299 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1300 {
1301         phdr->p_type = PT_NOTE;
1302         phdr->p_offset = offset;
1303         phdr->p_vaddr = 0;
1304         phdr->p_paddr = 0;
1305         phdr->p_filesz = sz;
1306         phdr->p_memsz = 0;
1307         phdr->p_flags = 0;
1308         phdr->p_align = 0;
1309         return;
1310 }
1311
1312 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1313                 unsigned int sz, void *data)
1314 {
1315         note->name = name;
1316         note->type = type;
1317         note->datasz = sz;
1318         note->data = data;
1319         return;
1320 }
1321
1322 /*
1323  * fill up all the fields in prstatus from the given task struct, except
1324  * registers which need to be filled up separately.
1325  */
1326 static void fill_prstatus(struct elf_prstatus *prstatus,
1327                           struct task_struct *p, long signr)
1328 {
1329         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1330         prstatus->pr_sigpend = p->pending.signal.sig[0];
1331         prstatus->pr_sighold = p->blocked.sig[0];
1332         rcu_read_lock();
1333         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1334         rcu_read_unlock();
1335         prstatus->pr_pid = task_pid_vnr(p);
1336         prstatus->pr_pgrp = task_pgrp_vnr(p);
1337         prstatus->pr_sid = task_session_vnr(p);
1338         if (thread_group_leader(p)) {
1339                 struct task_cputime cputime;
1340
1341                 /*
1342                  * This is the record for the group leader.  It shows the
1343                  * group-wide total, not its individual thread total.
1344                  */
1345                 thread_group_cputime(p, &cputime);
1346                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1347                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1348         } else {
1349                 cputime_t utime, stime;
1350
1351                 task_cputime(p, &utime, &stime);
1352                 cputime_to_timeval(utime, &prstatus->pr_utime);
1353                 cputime_to_timeval(stime, &prstatus->pr_stime);
1354         }
1355         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1356         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1357
1358         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1359         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1360 }
1361
1362 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1363                        struct mm_struct *mm)
1364 {
1365         const struct cred *cred;
1366         unsigned int i, len;
1367
1368         /* first copy the parameters from user space */
1369         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1370
1371         len = mm->arg_end - mm->arg_start;
1372         if (len >= ELF_PRARGSZ)
1373                 len = ELF_PRARGSZ - 1;
1374         if (copy_from_user(&psinfo->pr_psargs,
1375                            (const char __user *) mm->arg_start, len))
1376                 return -EFAULT;
1377         for (i = 0; i < len; i++)
1378                 if (psinfo->pr_psargs[i] == 0)
1379                         psinfo->pr_psargs[i] = ' ';
1380         psinfo->pr_psargs[len] = 0;
1381
1382         rcu_read_lock();
1383         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1384         rcu_read_unlock();
1385         psinfo->pr_pid = task_pid_vnr(p);
1386         psinfo->pr_pgrp = task_pgrp_vnr(p);
1387         psinfo->pr_sid = task_session_vnr(p);
1388
1389         i = p->state ? ffz(~p->state) + 1 : 0;
1390         psinfo->pr_state = i;
1391         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1392         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1393         psinfo->pr_nice = task_nice(p);
1394         psinfo->pr_flag = p->flags;
1395         rcu_read_lock();
1396         cred = __task_cred(p);
1397         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1398         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1399         rcu_read_unlock();
1400         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1401
1402         return 0;
1403 }
1404
1405 /* Here is the structure in which status of each thread is captured. */
1406 struct elf_thread_status
1407 {
1408         struct list_head list;
1409         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1410         elf_fpregset_t fpu;             /* NT_PRFPREG */
1411         struct task_struct *thread;
1412 #ifdef ELF_CORE_COPY_XFPREGS
1413         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1414 #endif
1415         struct memelfnote notes[3];
1416         int num_notes;
1417 };
1418
1419 /*
1420  * In order to add the specific thread information for the elf file format,
1421  * we need to keep a linked list of every thread's pr_status and then create
1422  * a single section for them in the final core file.
1423  */
1424 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1425 {
1426         struct task_struct *p = t->thread;
1427         int sz = 0;
1428
1429         t->num_notes = 0;
1430
1431         fill_prstatus(&t->prstatus, p, signr);
1432         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1433
1434         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1435                   &t->prstatus);
1436         t->num_notes++;
1437         sz += notesize(&t->notes[0]);
1438
1439         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1440         if (t->prstatus.pr_fpvalid) {
1441                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1442                           &t->fpu);
1443                 t->num_notes++;
1444                 sz += notesize(&t->notes[1]);
1445         }
1446
1447 #ifdef ELF_CORE_COPY_XFPREGS
1448         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1449                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1450                           sizeof(t->xfpu), &t->xfpu);
1451                 t->num_notes++;
1452                 sz += notesize(&t->notes[2]);
1453         }
1454 #endif
1455         return sz;
1456 }
1457
1458 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1459                              elf_addr_t e_shoff, int segs)
1460 {
1461         elf->e_shoff = e_shoff;
1462         elf->e_shentsize = sizeof(*shdr4extnum);
1463         elf->e_shnum = 1;
1464         elf->e_shstrndx = SHN_UNDEF;
1465
1466         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1467
1468         shdr4extnum->sh_type = SHT_NULL;
1469         shdr4extnum->sh_size = elf->e_shnum;
1470         shdr4extnum->sh_link = elf->e_shstrndx;
1471         shdr4extnum->sh_info = segs;
1472 }
1473
1474 /*
1475  * dump the segments for an MMU process
1476  */
1477 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1478 {
1479         struct vm_area_struct *vma;
1480
1481         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1482                 unsigned long addr;
1483
1484                 if (!maydump(vma, cprm->mm_flags))
1485                         continue;
1486
1487 #ifdef CONFIG_MMU
1488                 for (addr = vma->vm_start; addr < vma->vm_end;
1489                                                         addr += PAGE_SIZE) {
1490                         bool res;
1491                         struct page *page = get_dump_page(addr);
1492                         if (page) {
1493                                 void *kaddr = kmap(page);
1494                                 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1495                                 kunmap(page);
1496                                 page_cache_release(page);
1497                         } else {
1498                                 res = dump_skip(cprm, PAGE_SIZE);
1499                         }
1500                         if (!res)
1501                                 return false;
1502                 }
1503 #else
1504                 if (!dump_emit(cprm, (void *) vma->vm_start,
1505                                 vma->vm_end - vma->vm_start))
1506                         return false;
1507 #endif
1508         }
1509         return true;
1510 }
1511
1512 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1513 {
1514         struct vm_area_struct *vma;
1515         size_t size = 0;
1516
1517         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1518                 if (maydump(vma, mm_flags))
1519                         size += vma->vm_end - vma->vm_start;
1520         return size;
1521 }
1522
1523 /*
1524  * Actual dumper
1525  *
1526  * This is a two-pass process; first we find the offsets of the bits,
1527  * and then they are actually written out.  If we run out of core limit
1528  * we just truncate.
1529  */
1530 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1531 {
1532 #define NUM_NOTES       6
1533         int has_dumped = 0;
1534         mm_segment_t fs;
1535         int segs;
1536         int i;
1537         struct vm_area_struct *vma;
1538         struct elfhdr *elf = NULL;
1539         loff_t offset = 0, dataoff;
1540         int numnote;
1541         struct memelfnote *notes = NULL;
1542         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1543         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1544         LIST_HEAD(thread_list);
1545         struct list_head *t;
1546         elf_fpregset_t *fpu = NULL;
1547 #ifdef ELF_CORE_COPY_XFPREGS
1548         elf_fpxregset_t *xfpu = NULL;
1549 #endif
1550         int thread_status_size = 0;
1551         elf_addr_t *auxv;
1552         struct elf_phdr *phdr4note = NULL;
1553         struct elf_shdr *shdr4extnum = NULL;
1554         Elf_Half e_phnum;
1555         elf_addr_t e_shoff;
1556         struct core_thread *ct;
1557         struct elf_thread_status *tmp;
1558
1559         /*
1560          * We no longer stop all VM operations.
1561          *
1562          * This is because those proceses that could possibly change map_count
1563          * or the mmap / vma pages are now blocked in do_exit on current
1564          * finishing this core dump.
1565          *
1566          * Only ptrace can touch these memory addresses, but it doesn't change
1567          * the map_count or the pages allocated. So no possibility of crashing
1568          * exists while dumping the mm->vm_next areas to the core file.
1569          */
1570
1571         /* alloc memory for large data structures: too large to be on stack */
1572         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1573         if (!elf)
1574                 goto cleanup;
1575         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1576         if (!prstatus)
1577                 goto cleanup;
1578         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1579         if (!psinfo)
1580                 goto cleanup;
1581         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1582         if (!notes)
1583                 goto cleanup;
1584         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1585         if (!fpu)
1586                 goto cleanup;
1587 #ifdef ELF_CORE_COPY_XFPREGS
1588         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1589         if (!xfpu)
1590                 goto cleanup;
1591 #endif
1592
1593         for (ct = current->mm->core_state->dumper.next;
1594                                         ct; ct = ct->next) {
1595                 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1596                 if (!tmp)
1597                         goto cleanup;
1598
1599                 tmp->thread = ct->task;
1600                 list_add(&tmp->list, &thread_list);
1601         }
1602
1603         list_for_each(t, &thread_list) {
1604                 struct elf_thread_status *tmp;
1605                 int sz;
1606
1607                 tmp = list_entry(t, struct elf_thread_status, list);
1608                 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1609                 thread_status_size += sz;
1610         }
1611
1612         /* now collect the dump for the current */
1613         fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1614         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1615
1616         segs = current->mm->map_count;
1617         segs += elf_core_extra_phdrs();
1618
1619         /* for notes section */
1620         segs++;
1621
1622         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1623          * this, kernel supports extended numbering. Have a look at
1624          * include/linux/elf.h for further information. */
1625         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1626
1627         /* Set up header */
1628         fill_elf_fdpic_header(elf, e_phnum);
1629
1630         has_dumped = 1;
1631         /*
1632          * Set up the notes in similar form to SVR4 core dumps made
1633          * with info from their /proc.
1634          */
1635
1636         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1637         fill_psinfo(psinfo, current->group_leader, current->mm);
1638         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1639
1640         numnote = 2;
1641
1642         auxv = (elf_addr_t *) current->mm->saved_auxv;
1643
1644         i = 0;
1645         do
1646                 i += 2;
1647         while (auxv[i - 2] != AT_NULL);
1648         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1649                   i * sizeof(elf_addr_t), auxv);
1650
1651         /* Try to dump the FPU. */
1652         if ((prstatus->pr_fpvalid =
1653              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1654                 fill_note(notes + numnote++,
1655                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1656 #ifdef ELF_CORE_COPY_XFPREGS
1657         if (elf_core_copy_task_xfpregs(current, xfpu))
1658                 fill_note(notes + numnote++,
1659                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1660 #endif
1661
1662         fs = get_fs();
1663         set_fs(KERNEL_DS);
1664
1665         offset += sizeof(*elf);                         /* Elf header */
1666         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1667
1668         /* Write notes phdr entry */
1669         {
1670                 int sz = 0;
1671
1672                 for (i = 0; i < numnote; i++)
1673                         sz += notesize(notes + i);
1674
1675                 sz += thread_status_size;
1676
1677                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1678                 if (!phdr4note)
1679                         goto end_coredump;
1680
1681                 fill_elf_note_phdr(phdr4note, sz, offset);
1682                 offset += sz;
1683         }
1684
1685         /* Page-align dumped data */
1686         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1687
1688         offset += elf_core_vma_data_size(cprm->mm_flags);
1689         offset += elf_core_extra_data_size();
1690         e_shoff = offset;
1691
1692         if (e_phnum == PN_XNUM) {
1693                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1694                 if (!shdr4extnum)
1695                         goto end_coredump;
1696                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1697         }
1698
1699         offset = dataoff;
1700
1701         if (!dump_emit(cprm, elf, sizeof(*elf)))
1702                 goto end_coredump;
1703
1704         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1705                 goto end_coredump;
1706
1707         /* write program headers for segments dump */
1708         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1709                 struct elf_phdr phdr;
1710                 size_t sz;
1711
1712                 sz = vma->vm_end - vma->vm_start;
1713
1714                 phdr.p_type = PT_LOAD;
1715                 phdr.p_offset = offset;
1716                 phdr.p_vaddr = vma->vm_start;
1717                 phdr.p_paddr = 0;
1718                 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1719                 phdr.p_memsz = sz;
1720                 offset += phdr.p_filesz;
1721                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1722                 if (vma->vm_flags & VM_WRITE)
1723                         phdr.p_flags |= PF_W;
1724                 if (vma->vm_flags & VM_EXEC)
1725                         phdr.p_flags |= PF_X;
1726                 phdr.p_align = ELF_EXEC_PAGESIZE;
1727
1728                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1729                         goto end_coredump;
1730         }
1731
1732         if (!elf_core_write_extra_phdrs(cprm, offset))
1733                 goto end_coredump;
1734
1735         /* write out the notes section */
1736         for (i = 0; i < numnote; i++)
1737                 if (!writenote(notes + i, cprm))
1738                         goto end_coredump;
1739
1740         /* write out the thread status notes section */
1741         list_for_each(t, &thread_list) {
1742                 struct elf_thread_status *tmp =
1743                                 list_entry(t, struct elf_thread_status, list);
1744
1745                 for (i = 0; i < tmp->num_notes; i++)
1746                         if (!writenote(&tmp->notes[i], cprm))
1747                                 goto end_coredump;
1748         }
1749
1750         if (!dump_skip(cprm, dataoff - cprm->written))
1751                 goto end_coredump;
1752
1753         if (!elf_fdpic_dump_segments(cprm))
1754                 goto end_coredump;
1755
1756         if (!elf_core_write_extra_data(cprm))
1757                 goto end_coredump;
1758
1759         if (e_phnum == PN_XNUM) {
1760                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1761                         goto end_coredump;
1762         }
1763
1764         if (cprm->file->f_pos != offset) {
1765                 /* Sanity check */
1766                 printk(KERN_WARNING
1767                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1768                        cprm->file->f_pos, offset);
1769         }
1770
1771 end_coredump:
1772         set_fs(fs);
1773
1774 cleanup:
1775         while (!list_empty(&thread_list)) {
1776                 struct list_head *tmp = thread_list.next;
1777                 list_del(tmp);
1778                 kfree(list_entry(tmp, struct elf_thread_status, list));
1779         }
1780         kfree(phdr4note);
1781         kfree(elf);
1782         kfree(prstatus);
1783         kfree(psinfo);
1784         kfree(notes);
1785         kfree(fpu);
1786         kfree(shdr4extnum);
1787 #ifdef ELF_CORE_COPY_XFPREGS
1788         kfree(xfpu);
1789 #endif
1790         return has_dumped;
1791 #undef NUM_NOTES
1792 }
1793
1794 #endif          /* CONFIG_ELF_CORE */