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