linux/fs/binfmt_elf_fdpic.c
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   1/* binfmt_elf_fdpic.c: FDPIC ELF binary format
   2 *
   3 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
   4 * Written by David Howells (dhowells@redhat.com)
   5 * Derived from binfmt_elf.c
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * as published by the Free Software Foundation; either version
  10 * 2 of the License, or (at your option) any later version.
  11 */
  12
  13#include <linux/module.h>
  14
  15#include <linux/fs.h>
  16#include <linux/stat.h>
  17#include <linux/sched.h>
  18#include <linux/mm.h>
  19#include <linux/mman.h>
  20#include <linux/errno.h>
  21#include <linux/signal.h>
  22#include <linux/binfmts.h>
  23#include <linux/string.h>
  24#include <linux/file.h>
  25#include <linux/fcntl.h>
  26#include <linux/slab.h>
  27#include <linux/pagemap.h>
  28#include <linux/security.h>
  29#include <linux/highmem.h>
  30#include <linux/highuid.h>
  31#include <linux/personality.h>
  32#include <linux/ptrace.h>
  33#include <linux/init.h>
  34#include <linux/elf.h>
  35#include <linux/elf-fdpic.h>
  36#include <linux/elfcore.h>
  37
  38#include <asm/uaccess.h>
  39#include <asm/param.h>
  40#include <asm/pgalloc.h>
  41
  42typedef char *elf_caddr_t;
  43
  44#if 0
  45#define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  46#else
  47#define kdebug(fmt, ...) do {} while(0)
  48#endif
  49
  50#if 0
  51#define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  52#else
  53#define kdcore(fmt, ...) do {} while(0)
  54#endif
  55
  56MODULE_LICENSE("GPL");
  57
  58static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
  59static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  60static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  61                              struct mm_struct *, const char *);
  62
  63static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  64                                   struct elf_fdpic_params *,
  65                                   struct elf_fdpic_params *);
  66
  67#ifndef CONFIG_MMU
  68static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
  69                                            unsigned long *);
  70static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  71                                                   struct file *,
  72                                                   struct mm_struct *);
  73#endif
  74
  75static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  76                                             struct file *, struct mm_struct *);
  77
  78#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  79static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit);
  80#endif
  81
  82static struct linux_binfmt elf_fdpic_format = {
  83        .module         = THIS_MODULE,
  84        .load_binary    = load_elf_fdpic_binary,
  85#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
  86        .core_dump      = elf_fdpic_core_dump,
  87#endif
  88        .min_coredump   = ELF_EXEC_PAGESIZE,
  89};
  90
  91static int __init init_elf_fdpic_binfmt(void)
  92{
  93        return register_binfmt(&elf_fdpic_format);
  94}
  95
  96static void __exit exit_elf_fdpic_binfmt(void)
  97{
  98        unregister_binfmt(&elf_fdpic_format);
  99}
 100
 101core_initcall(init_elf_fdpic_binfmt);
 102module_exit(exit_elf_fdpic_binfmt);
 103
 104static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
 105{
 106        if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 107                return 0;
 108        if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 109                return 0;
 110        if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
 111                return 0;
 112        if (!file->f_op || !file->f_op->mmap)
 113                return 0;
 114        return 1;
 115}
 116
 117/*****************************************************************************/
 118/*
 119 * read the program headers table into memory
 120 */
 121static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 122                                 struct file *file)
 123{
 124        struct elf32_phdr *phdr;
 125        unsigned long size;
 126        int retval, loop;
 127
 128        if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 129                return -ENOMEM;
 130        if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 131                return -ENOMEM;
 132
 133        size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 134        params->phdrs = kmalloc(size, GFP_KERNEL);
 135        if (!params->phdrs)
 136                return -ENOMEM;
 137
 138        retval = kernel_read(file, params->hdr.e_phoff,
 139                             (char *) params->phdrs, size);
 140        if (unlikely(retval != size))
 141                return retval < 0 ? retval : -ENOEXEC;
 142
 143        /* determine stack size for this binary */
 144        phdr = params->phdrs;
 145        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 146                if (phdr->p_type != PT_GNU_STACK)
 147                        continue;
 148
 149                if (phdr->p_flags & PF_X)
 150                        params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 151                else
 152                        params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 153
 154                params->stack_size = phdr->p_memsz;
 155                break;
 156        }
 157
 158        return 0;
 159}
 160
 161/*****************************************************************************/
 162/*
 163 * load an fdpic binary into various bits of memory
 164 */
 165static int load_elf_fdpic_binary(struct linux_binprm *bprm,
 166                                 struct pt_regs *regs)
 167{
 168        struct elf_fdpic_params exec_params, interp_params;
 169        struct elf_phdr *phdr;
 170        unsigned long stack_size, entryaddr;
 171#ifndef CONFIG_MMU
 172        unsigned long fullsize;
 173#endif
 174#ifdef ELF_FDPIC_PLAT_INIT
 175        unsigned long dynaddr;
 176#endif
 177        struct file *interpreter = NULL; /* to shut gcc up */
 178        char *interpreter_name = NULL;
 179        int executable_stack;
 180        int retval, i;
 181
 182        kdebug("____ LOAD %d ____", current->pid);
 183
 184        memset(&exec_params, 0, sizeof(exec_params));
 185        memset(&interp_params, 0, sizeof(interp_params));
 186
 187        exec_params.hdr = *(struct elfhdr *) bprm->buf;
 188        exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 189
 190        /* check that this is a binary we know how to deal with */
 191        retval = -ENOEXEC;
 192        if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
 193                goto error;
 194
 195        /* read the program header table */
 196        retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 197        if (retval < 0)
 198                goto error;
 199
 200        /* scan for a program header that specifies an interpreter */
 201        phdr = exec_params.phdrs;
 202
 203        for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 204                switch (phdr->p_type) {
 205                case PT_INTERP:
 206                        retval = -ENOMEM;
 207                        if (phdr->p_filesz > PATH_MAX)
 208                                goto error;
 209                        retval = -ENOENT;
 210                        if (phdr->p_filesz < 2)
 211                                goto error;
 212
 213                        /* read the name of the interpreter into memory */
 214                        interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 215                        if (!interpreter_name)
 216                                goto error;
 217
 218                        retval = kernel_read(bprm->file,
 219                                             phdr->p_offset,
 220                                             interpreter_name,
 221                                             phdr->p_filesz);
 222                        if (unlikely(retval != phdr->p_filesz)) {
 223                                if (retval >= 0)
 224                                        retval = -ENOEXEC;
 225                                goto error;
 226                        }
 227
 228                        retval = -ENOENT;
 229                        if (interpreter_name[phdr->p_filesz - 1] != '\0')
 230                                goto error;
 231
 232                        kdebug("Using ELF interpreter %s", interpreter_name);
 233
 234                        /* replace the program with the interpreter */
 235                        interpreter = open_exec(interpreter_name);
 236                        retval = PTR_ERR(interpreter);
 237                        if (IS_ERR(interpreter)) {
 238                                interpreter = NULL;
 239                                goto error;
 240                        }
 241
 242                        /*
 243                         * If the binary is not readable then enforce
 244                         * mm->dumpable = 0 regardless of the interpreter's
 245                         * permissions.
 246                         */
 247                        if (file_permission(interpreter, MAY_READ) < 0)
 248                                bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
 249
 250                        retval = kernel_read(interpreter, 0, bprm->buf,
 251                                             BINPRM_BUF_SIZE);
 252                        if (unlikely(retval != BINPRM_BUF_SIZE)) {
 253                                if (retval >= 0)
 254                                        retval = -ENOEXEC;
 255                                goto error;
 256                        }
 257
 258                        interp_params.hdr = *((struct elfhdr *) bprm->buf);
 259                        break;
 260
 261                case PT_LOAD:
 262#ifdef CONFIG_MMU
 263                        if (exec_params.load_addr == 0)
 264                                exec_params.load_addr = phdr->p_vaddr;
 265#endif
 266                        break;
 267                }
 268
 269        }
 270
 271        if (elf_check_const_displacement(&exec_params.hdr))
 272                exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 273
 274        /* perform insanity checks on the interpreter */
 275        if (interpreter_name) {
 276                retval = -ELIBBAD;
 277                if (!is_elf_fdpic(&interp_params.hdr, interpreter))
 278                        goto error;
 279
 280                interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 281
 282                /* read the interpreter's program header table */
 283                retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 284                if (retval < 0)
 285                        goto error;
 286        }
 287
 288        stack_size = exec_params.stack_size;
 289        if (stack_size < interp_params.stack_size)
 290                stack_size = interp_params.stack_size;
 291
 292        if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 293                executable_stack = EXSTACK_ENABLE_X;
 294        else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 295                executable_stack = EXSTACK_DISABLE_X;
 296        else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 297                executable_stack = EXSTACK_ENABLE_X;
 298        else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 299                executable_stack = EXSTACK_DISABLE_X;
 300        else
 301                executable_stack = EXSTACK_DEFAULT;
 302
 303        retval = -ENOEXEC;
 304        if (stack_size == 0)
 305                goto error;
 306
 307        if (elf_check_const_displacement(&interp_params.hdr))
 308                interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 309
 310        /* flush all traces of the currently running executable */
 311        retval = flush_old_exec(bprm);
 312        if (retval)
 313                goto error;
 314
 315        /* there's now no turning back... the old userspace image is dead,
 316         * defunct, deceased, etc. after this point we have to exit via
 317         * error_kill */
 318        set_personality(PER_LINUX_FDPIC);
 319        set_binfmt(&elf_fdpic_format);
 320
 321        current->mm->start_code = 0;
 322        current->mm->end_code = 0;
 323        current->mm->start_stack = 0;
 324        current->mm->start_data = 0;
 325        current->mm->end_data = 0;
 326        current->mm->context.exec_fdpic_loadmap = 0;
 327        current->mm->context.interp_fdpic_loadmap = 0;
 328
 329        current->flags &= ~PF_FORKNOEXEC;
 330
 331#ifdef CONFIG_MMU
 332        elf_fdpic_arch_lay_out_mm(&exec_params,
 333                                  &interp_params,
 334                                  &current->mm->start_stack,
 335                                  &current->mm->start_brk);
 336
 337        retval = setup_arg_pages(bprm, current->mm->start_stack,
 338                                 executable_stack);
 339        if (retval < 0) {
 340                send_sig(SIGKILL, current, 0);
 341                goto error_kill;
 342        }
 343#endif
 344
 345        /* load the executable and interpreter into memory */
 346        retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 347                                    "executable");
 348        if (retval < 0)
 349                goto error_kill;
 350
 351        if (interpreter_name) {
 352                retval = elf_fdpic_map_file(&interp_params, interpreter,
 353                                            current->mm, "interpreter");
 354                if (retval < 0) {
 355                        printk(KERN_ERR "Unable to load interpreter\n");
 356                        goto error_kill;
 357                }
 358
 359                allow_write_access(interpreter);
 360                fput(interpreter);
 361                interpreter = NULL;
 362        }
 363
 364#ifdef CONFIG_MMU
 365        if (!current->mm->start_brk)
 366                current->mm->start_brk = current->mm->end_data;
 367
 368        current->mm->brk = current->mm->start_brk =
 369                PAGE_ALIGN(current->mm->start_brk);
 370
 371#else
 372        /* create a stack and brk area big enough for everyone
 373         * - the brk heap starts at the bottom and works up
 374         * - the stack starts at the top and works down
 375         */
 376        stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 377        if (stack_size < PAGE_SIZE * 2)
 378                stack_size = PAGE_SIZE * 2;
 379
 380        down_write(&current->mm->mmap_sem);
 381        current->mm->start_brk = do_mmap(NULL, 0, stack_size,
 382                                         PROT_READ | PROT_WRITE | PROT_EXEC,
 383                                         MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
 384                                         0);
 385
 386        if (IS_ERR_VALUE(current->mm->start_brk)) {
 387                up_write(&current->mm->mmap_sem);
 388                retval = current->mm->start_brk;
 389                current->mm->start_brk = 0;
 390                goto error_kill;
 391        }
 392
 393        /* expand the stack mapping to use up the entire allocation granule */
 394        fullsize = kobjsize((char *) current->mm->start_brk);
 395        if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
 396                                    fullsize, 0, 0)))
 397                stack_size = fullsize;
 398        up_write(&current->mm->mmap_sem);
 399
 400        current->mm->brk = current->mm->start_brk;
 401        current->mm->context.end_brk = current->mm->start_brk;
 402        current->mm->context.end_brk +=
 403                (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 404        current->mm->start_stack = current->mm->start_brk + stack_size;
 405#endif
 406
 407        compute_creds(bprm);
 408        current->flags &= ~PF_FORKNOEXEC;
 409        if (create_elf_fdpic_tables(bprm, current->mm,
 410                                    &exec_params, &interp_params) < 0)
 411                goto error_kill;
 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
 439error:
 440        if (interpreter) {
 441                allow_write_access(interpreter);
 442                fput(interpreter);
 443        }
 444        kfree(interpreter_name);
 445        kfree(exec_params.phdrs);
 446        kfree(exec_params.loadmap);
 447        kfree(interp_params.phdrs);
 448        kfree(interp_params.loadmap);
 449        return retval;
 450
 451        /* unrecoverable error - kill the process */
 452error_kill:
 453        send_sig(SIGSEGV, current, 0);
 454        goto error;
 455
 456}
 457
 458/*****************************************************************************/
 459
 460#ifndef ELF_BASE_PLATFORM
 461/*
 462 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 463 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 464 * will be copied to the user stack in the same manner as AT_PLATFORM.
 465 */
 466#define ELF_BASE_PLATFORM NULL
 467#endif
 468
 469/*
 470 * present useful information to the program by shovelling it onto the new
 471 * process's stack
 472 */
 473static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 474                                   struct mm_struct *mm,
 475                                   struct elf_fdpic_params *exec_params,
 476                                   struct elf_fdpic_params *interp_params)
 477{
 478        unsigned long sp, csp, nitems;
 479        elf_caddr_t __user *argv, *envp;
 480        size_t platform_len = 0, len;
 481        char *k_platform, *k_base_platform;
 482        char __user *u_platform, *u_base_platform, *p;
 483        long hwcap;
 484        int loop;
 485        int nr; /* reset for each csp adjustment */
 486
 487#ifdef CONFIG_MMU
 488        /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 489         * by the processes running on the same package. One thing we can do is
 490         * to shuffle the initial stack for them, so we give the architecture
 491         * an opportunity to do so here.
 492         */
 493        sp = arch_align_stack(bprm->p);
 494#else
 495        sp = mm->start_stack;
 496
 497        /* stack the program arguments and environment */
 498        if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 499                return -EFAULT;
 500#endif
 501
 502        hwcap = ELF_HWCAP;
 503
 504        /*
 505         * If this architecture has a platform capability string, copy it
 506         * to userspace.  In some cases (Sparc), this info is impossible
 507         * for userspace to get any other way, in others (i386) it is
 508         * merely difficult.
 509         */
 510        k_platform = ELF_PLATFORM;
 511        u_platform = NULL;
 512
 513        if (k_platform) {
 514                platform_len = strlen(k_platform) + 1;
 515                sp -= platform_len;
 516                u_platform = (char __user *) sp;
 517                if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 518                        return -EFAULT;
 519        }
 520
 521        /*
 522         * If this architecture has a "base" platform capability
 523         * string, copy it to userspace.
 524         */
 525        k_base_platform = ELF_BASE_PLATFORM;
 526        u_base_platform = NULL;
 527
 528        if (k_base_platform) {
 529                platform_len = strlen(k_base_platform) + 1;
 530                sp -= platform_len;
 531                u_base_platform = (char __user *) sp;
 532                if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 533                        return -EFAULT;
 534        }
 535
 536        sp &= ~7UL;
 537
 538        /* stack the load map(s) */
 539        len = sizeof(struct elf32_fdpic_loadmap);
 540        len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 541        sp = (sp - len) & ~7UL;
 542        exec_params->map_addr = sp;
 543
 544        if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 545                return -EFAULT;
 546
 547        current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 548
 549        if (interp_params->loadmap) {
 550                len = sizeof(struct elf32_fdpic_loadmap);
 551                len += sizeof(struct elf32_fdpic_loadseg) *
 552                        interp_params->loadmap->nsegs;
 553                sp = (sp - len) & ~7UL;
 554                interp_params->map_addr = sp;
 555
 556                if (copy_to_user((void __user *) sp, interp_params->loadmap,
 557                                 len) != 0)
 558                        return -EFAULT;
 559
 560                current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 561        }
 562
 563        /* force 16 byte _final_ alignment here for generality */
 564#define DLINFO_ITEMS 15
 565
 566        nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 567                (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 568
 569        if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
 570                nitems++;
 571
 572        csp = sp;
 573        sp -= nitems * 2 * sizeof(unsigned long);
 574        sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 575        sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 576        sp -= 1 * sizeof(unsigned long);                /* argc */
 577
 578        csp -= sp & 15UL;
 579        sp -= sp & 15UL;
 580
 581        /* put the ELF interpreter info on the stack */
 582#define NEW_AUX_ENT(id, val)                                            \
 583        do {                                                            \
 584                struct { unsigned long _id, _val; } __user *ent;        \
 585                                                                        \
 586                ent = (void __user *) csp;                              \
 587                __put_user((id), &ent[nr]._id);                         \
 588                __put_user((val), &ent[nr]._val);                       \
 589                nr++;                                                   \
 590        } while (0)
 591
 592        nr = 0;
 593        csp -= 2 * sizeof(unsigned long);
 594        NEW_AUX_ENT(AT_NULL, 0);
 595        if (k_platform) {
 596                nr = 0;
 597                csp -= 2 * sizeof(unsigned long);
 598                NEW_AUX_ENT(AT_PLATFORM,
 599                            (elf_addr_t) (unsigned long) u_platform);
 600        }
 601
 602        if (k_base_platform) {
 603                nr = 0;
 604                csp -= 2 * sizeof(unsigned long);
 605                NEW_AUX_ENT(AT_BASE_PLATFORM,
 606                            (elf_addr_t) (unsigned long) u_base_platform);
 607        }
 608
 609        if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 610                nr = 0;
 611                csp -= 2 * sizeof(unsigned long);
 612                NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 613        }
 614
 615        nr = 0;
 616        csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 617        NEW_AUX_ENT(AT_HWCAP,   hwcap);
 618        NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 619        NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 620        NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 621        NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 622        NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 623        NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 624        NEW_AUX_ENT(AT_FLAGS,   0);
 625        NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 626        NEW_AUX_ENT(AT_UID,     (elf_addr_t) current->uid);
 627        NEW_AUX_ENT(AT_EUID,    (elf_addr_t) current->euid);
 628        NEW_AUX_ENT(AT_GID,     (elf_addr_t) current->gid);
 629        NEW_AUX_ENT(AT_EGID,    (elf_addr_t) current->egid);
 630        NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
 631        NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 632
 633#ifdef ARCH_DLINFO
 634        nr = 0;
 635        csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 636
 637        /* ARCH_DLINFO must come last so platform specific code can enforce
 638         * special alignment requirements on the AUXV if necessary (eg. PPC).
 639         */
 640        ARCH_DLINFO;
 641#endif
 642#undef NEW_AUX_ENT
 643
 644        /* allocate room for argv[] and envv[] */
 645        csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 646        envp = (elf_caddr_t __user *) csp;
 647        csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 648        argv = (elf_caddr_t __user *) csp;
 649
 650        /* stack argc */
 651        csp -= sizeof(unsigned long);
 652        __put_user(bprm->argc, (unsigned long __user *) csp);
 653
 654        BUG_ON(csp != sp);
 655
 656        /* fill in the argv[] array */
 657#ifdef CONFIG_MMU
 658        current->mm->arg_start = bprm->p;
 659#else
 660        current->mm->arg_start = current->mm->start_stack -
 661                (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 662#endif
 663
 664        p = (char __user *) current->mm->arg_start;
 665        for (loop = bprm->argc; loop > 0; loop--) {
 666                __put_user((elf_caddr_t) p, argv++);
 667                len = strnlen_user(p, MAX_ARG_STRLEN);
 668                if (!len || len > MAX_ARG_STRLEN)
 669                        return -EINVAL;
 670                p += len;
 671        }
 672        __put_user(NULL, argv);
 673        current->mm->arg_end = (unsigned long) p;
 674
 675        /* fill in the envv[] array */
 676        current->mm->env_start = (unsigned long) p;
 677        for (loop = bprm->envc; loop > 0; loop--) {
 678                __put_user((elf_caddr_t)(unsigned long) p, envp++);
 679                len = strnlen_user(p, MAX_ARG_STRLEN);
 680                if (!len || len > MAX_ARG_STRLEN)
 681                        return -EINVAL;
 682                p += len;
 683        }
 684        __put_user(NULL, envp);
 685        current->mm->env_end = (unsigned long) p;
 686
 687        mm->start_stack = (unsigned long) sp;
 688        return 0;
 689}
 690
 691/*****************************************************************************/
 692/*
 693 * transfer the program arguments and environment from the holding pages onto
 694 * the stack
 695 */
 696#ifndef CONFIG_MMU
 697static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 698                                            unsigned long *_sp)
 699{
 700        unsigned long index, stop, sp;
 701        char *src;
 702        int ret = 0;
 703
 704        stop = bprm->p >> PAGE_SHIFT;
 705        sp = *_sp;
 706
 707        for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 708                src = kmap(bprm->page[index]);
 709                sp -= PAGE_SIZE;
 710                if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 711                        ret = -EFAULT;
 712                kunmap(bprm->page[index]);
 713                if (ret < 0)
 714                        goto out;
 715        }
 716
 717        *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 718
 719out:
 720        return ret;
 721}
 722#endif
 723
 724/*****************************************************************************/
 725/*
 726 * load the appropriate binary image (executable or interpreter) into memory
 727 * - we assume no MMU is available
 728 * - if no other PIC bits are set in params->hdr->e_flags
 729 *   - we assume that the LOADable segments in the binary are independently relocatable
 730 *   - we assume R/O executable segments are shareable
 731 * - else
 732 *   - we assume the loadable parts of the image to require fixed displacement
 733 *   - the image is not shareable
 734 */
 735static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 736                              struct file *file,
 737                              struct mm_struct *mm,
 738                              const char *what)
 739{
 740        struct elf32_fdpic_loadmap *loadmap;
 741#ifdef CONFIG_MMU
 742        struct elf32_fdpic_loadseg *mseg;
 743#endif
 744        struct elf32_fdpic_loadseg *seg;
 745        struct elf32_phdr *phdr;
 746        unsigned long load_addr, stop;
 747        unsigned nloads, tmp;
 748        size_t size;
 749        int loop, ret;
 750
 751        /* allocate a load map table */
 752        nloads = 0;
 753        for (loop = 0; loop < params->hdr.e_phnum; loop++)
 754                if (params->phdrs[loop].p_type == PT_LOAD)
 755                        nloads++;
 756
 757        if (nloads == 0)
 758                return -ELIBBAD;
 759
 760        size = sizeof(*loadmap) + nloads * sizeof(*seg);
 761        loadmap = kzalloc(size, GFP_KERNEL);
 762        if (!loadmap)
 763                return -ENOMEM;
 764
 765        params->loadmap = loadmap;
 766
 767        loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 768        loadmap->nsegs = nloads;
 769
 770        load_addr = params->load_addr;
 771        seg = loadmap->segs;
 772
 773        /* map the requested LOADs into the memory space */
 774        switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 775        case ELF_FDPIC_FLAG_CONSTDISP:
 776        case ELF_FDPIC_FLAG_CONTIGUOUS:
 777#ifndef CONFIG_MMU
 778                ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 779                if (ret < 0)
 780                        return ret;
 781                break;
 782#endif
 783        default:
 784                ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 785                if (ret < 0)
 786                        return ret;
 787                break;
 788        }
 789
 790        /* map the entry point */
 791        if (params->hdr.e_entry) {
 792                seg = loadmap->segs;
 793                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 794                        if (params->hdr.e_entry >= seg->p_vaddr &&
 795                            params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 796                                params->entry_addr =
 797                                        (params->hdr.e_entry - seg->p_vaddr) +
 798                                        seg->addr;
 799                                break;
 800                        }
 801                }
 802        }
 803
 804        /* determine where the program header table has wound up if mapped */
 805        stop = params->hdr.e_phoff;
 806        stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 807        phdr = params->phdrs;
 808
 809        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 810                if (phdr->p_type != PT_LOAD)
 811                        continue;
 812
 813                if (phdr->p_offset > params->hdr.e_phoff ||
 814                    phdr->p_offset + phdr->p_filesz < stop)
 815                        continue;
 816
 817                seg = loadmap->segs;
 818                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 819                        if (phdr->p_vaddr >= seg->p_vaddr &&
 820                            phdr->p_vaddr + phdr->p_filesz <=
 821                            seg->p_vaddr + seg->p_memsz) {
 822                                params->ph_addr =
 823                                        (phdr->p_vaddr - seg->p_vaddr) +
 824                                        seg->addr +
 825                                        params->hdr.e_phoff - phdr->p_offset;
 826                                break;
 827                        }
 828                }
 829                break;
 830        }
 831
 832        /* determine where the dynamic section has wound up if there is one */
 833        phdr = params->phdrs;
 834        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 835                if (phdr->p_type != PT_DYNAMIC)
 836                        continue;
 837
 838                seg = loadmap->segs;
 839                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 840                        if (phdr->p_vaddr >= seg->p_vaddr &&
 841                            phdr->p_vaddr + phdr->p_memsz <=
 842                            seg->p_vaddr + seg->p_memsz) {
 843                                params->dynamic_addr =
 844                                        (phdr->p_vaddr - seg->p_vaddr) +
 845                                        seg->addr;
 846
 847                                /* check the dynamic section contains at least
 848                                 * one item, and that the last item is a NULL
 849                                 * entry */
 850                                if (phdr->p_memsz == 0 ||
 851                                    phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 852                                        goto dynamic_error;
 853
 854                                tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 855                                if (((Elf32_Dyn *)
 856                                     params->dynamic_addr)[tmp - 1].d_tag != 0)
 857                                        goto dynamic_error;
 858                                break;
 859                        }
 860                }
 861                break;
 862        }
 863
 864        /* now elide adjacent segments in the load map on MMU linux
 865         * - on uClinux the holes between may actually be filled with system
 866         *   stuff or stuff from other processes
 867         */
 868#ifdef CONFIG_MMU
 869        nloads = loadmap->nsegs;
 870        mseg = loadmap->segs;
 871        seg = mseg + 1;
 872        for (loop = 1; loop < nloads; loop++) {
 873                /* see if we have a candidate for merging */
 874                if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 875                        load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 876                        if (load_addr == (seg->addr & PAGE_MASK)) {
 877                                mseg->p_memsz +=
 878                                        load_addr -
 879                                        (mseg->addr + mseg->p_memsz);
 880                                mseg->p_memsz += seg->addr & ~PAGE_MASK;
 881                                mseg->p_memsz += seg->p_memsz;
 882                                loadmap->nsegs--;
 883                                continue;
 884                        }
 885                }
 886
 887                mseg++;
 888                if (mseg != seg)
 889                        *mseg = *seg;
 890        }
 891#endif
 892
 893        kdebug("Mapped Object [%s]:", what);
 894        kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 895        kdebug("- entry    : %lx", params->entry_addr);
 896        kdebug("- PHDR[]   : %lx", params->ph_addr);
 897        kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 898        seg = loadmap->segs;
 899        for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 900                kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 901                       loop,
 902                       seg->addr, seg->addr + seg->p_memsz - 1,
 903                       seg->p_vaddr, seg->p_memsz);
 904
 905        return 0;
 906
 907dynamic_error:
 908        printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 909               what, file->f_path.dentry->d_inode->i_ino);
 910        return -ELIBBAD;
 911}
 912
 913/*****************************************************************************/
 914/*
 915 * map a file with constant displacement under uClinux
 916 */
 917#ifndef CONFIG_MMU
 918static int elf_fdpic_map_file_constdisp_on_uclinux(
 919        struct elf_fdpic_params *params,
 920        struct file *file,
 921        struct mm_struct *mm)
 922{
 923        struct elf32_fdpic_loadseg *seg;
 924        struct elf32_phdr *phdr;
 925        unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 926        loff_t fpos;
 927        int loop, ret;
 928
 929        load_addr = params->load_addr;
 930        seg = params->loadmap->segs;
 931
 932        /* determine the bounds of the contiguous overall allocation we must
 933         * make */
 934        phdr = params->phdrs;
 935        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 936                if (params->phdrs[loop].p_type != PT_LOAD)
 937                        continue;
 938
 939                if (base > phdr->p_vaddr)
 940                        base = phdr->p_vaddr;
 941                if (top < phdr->p_vaddr + phdr->p_memsz)
 942                        top = phdr->p_vaddr + phdr->p_memsz;
 943        }
 944
 945        /* allocate one big anon block for everything */
 946        mflags = MAP_PRIVATE;
 947        if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 948                mflags |= MAP_EXECUTABLE;
 949
 950        down_write(&mm->mmap_sem);
 951        maddr = do_mmap(NULL, load_addr, top - base,
 952                        PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 953        up_write(&mm->mmap_sem);
 954        if (IS_ERR_VALUE(maddr))
 955                return (int) maddr;
 956
 957        if (load_addr != 0)
 958                load_addr += PAGE_ALIGN(top - base);
 959
 960        /* and then load the file segments into it */
 961        phdr = params->phdrs;
 962        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 963                if (params->phdrs[loop].p_type != PT_LOAD)
 964                        continue;
 965
 966                fpos = phdr->p_offset;
 967
 968                seg->addr = maddr + (phdr->p_vaddr - base);
 969                seg->p_vaddr = phdr->p_vaddr;
 970                seg->p_memsz = phdr->p_memsz;
 971
 972                ret = file->f_op->read(file, (void *) seg->addr,
 973                                       phdr->p_filesz, &fpos);
 974                if (ret < 0)
 975                        return ret;
 976
 977                /* map the ELF header address if in this segment */
 978                if (phdr->p_offset == 0)
 979                        params->elfhdr_addr = seg->addr;
 980
 981                /* clear any space allocated but not loaded */
 982                if (phdr->p_filesz < phdr->p_memsz)
 983                        clear_user((void *) (seg->addr + phdr->p_filesz),
 984                                   phdr->p_memsz - phdr->p_filesz);
 985
 986                if (mm) {
 987                        if (phdr->p_flags & PF_X) {
 988                                if (!mm->start_code) {
 989                                        mm->start_code = seg->addr;
 990                                        mm->end_code = seg->addr +
 991                                                phdr->p_memsz;
 992                                }
 993                        } else if (!mm->start_data) {
 994                                mm->start_data = seg->addr;
 995#ifndef CONFIG_MMU
 996                                mm->end_data = seg->addr + phdr->p_memsz;
 997#endif
 998                        }
 999
1000#ifdef CONFIG_MMU
1001                        if (seg->addr + phdr->p_memsz > mm->end_data)
1002                                mm->end_data = seg->addr + phdr->p_memsz;
1003#endif
1004                }
1005
1006                seg++;
1007        }
1008
1009        return 0;
1010}
1011#endif
1012
1013/*****************************************************************************/
1014/*
1015 * map a binary by direct mmap() of the individual PT_LOAD segments
1016 */
1017static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1018                                             struct file *file,
1019                                             struct mm_struct *mm)
1020{
1021        struct elf32_fdpic_loadseg *seg;
1022        struct elf32_phdr *phdr;
1023        unsigned long load_addr, delta_vaddr;
1024        int loop, dvset;
1025
1026        load_addr = params->load_addr;
1027        delta_vaddr = 0;
1028        dvset = 0;
1029
1030        seg = params->loadmap->segs;
1031
1032        /* deal with each load segment separately */
1033        phdr = params->phdrs;
1034        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1035                unsigned long maddr, disp, excess, excess1;
1036                int prot = 0, flags;
1037
1038                if (phdr->p_type != PT_LOAD)
1039                        continue;
1040
1041                kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1042                       (unsigned long) phdr->p_vaddr,
1043                       (unsigned long) phdr->p_offset,
1044                       (unsigned long) phdr->p_filesz,
1045                       (unsigned long) phdr->p_memsz);
1046
1047                /* determine the mapping parameters */
1048                if (phdr->p_flags & PF_R) prot |= PROT_READ;
1049                if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1050                if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1051
1052                flags = MAP_PRIVATE | MAP_DENYWRITE;
1053                if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1054                        flags |= MAP_EXECUTABLE;
1055
1056                maddr = 0;
1057
1058                switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1059                case ELF_FDPIC_FLAG_INDEPENDENT:
1060                        /* PT_LOADs are independently locatable */
1061                        break;
1062
1063                case ELF_FDPIC_FLAG_HONOURVADDR:
1064                        /* the specified virtual address must be honoured */
1065                        maddr = phdr->p_vaddr;
1066                        flags |= MAP_FIXED;
1067                        break;
1068
1069                case ELF_FDPIC_FLAG_CONSTDISP:
1070                        /* constant displacement
1071                         * - can be mapped anywhere, but must be mapped as a
1072                         *   unit
1073                         */
1074                        if (!dvset) {
1075                                maddr = load_addr;
1076                                delta_vaddr = phdr->p_vaddr;
1077                                dvset = 1;
1078                        } else {
1079                                maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1080                                flags |= MAP_FIXED;
1081                        }
1082                        break;
1083
1084                case ELF_FDPIC_FLAG_CONTIGUOUS:
1085                        /* contiguity handled later */
1086                        break;
1087
1088                default:
1089                        BUG();
1090                }
1091
1092                maddr &= PAGE_MASK;
1093
1094                /* create the mapping */
1095                disp = phdr->p_vaddr & ~PAGE_MASK;
1096                down_write(&mm->mmap_sem);
1097                maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1098                                phdr->p_offset - disp);
1099                up_write(&mm->mmap_sem);
1100
1101                kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1102                       loop, phdr->p_memsz + disp, prot, flags,
1103                       phdr->p_offset - disp, maddr);
1104
1105                if (IS_ERR_VALUE(maddr))
1106                        return (int) maddr;
1107
1108                if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1109                    ELF_FDPIC_FLAG_CONTIGUOUS)
1110                        load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1111
1112                seg->addr = maddr + disp;
1113                seg->p_vaddr = phdr->p_vaddr;
1114                seg->p_memsz = phdr->p_memsz;
1115
1116                /* map the ELF header address if in this segment */
1117                if (phdr->p_offset == 0)
1118                        params->elfhdr_addr = seg->addr;
1119
1120                /* clear the bit between beginning of mapping and beginning of
1121                 * PT_LOAD */
1122                if (prot & PROT_WRITE && disp > 0) {
1123                        kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1124                        clear_user((void __user *) maddr, disp);
1125                        maddr += disp;
1126                }
1127
1128                /* clear any space allocated but not loaded
1129                 * - on uClinux we can just clear the lot
1130                 * - on MMU linux we'll get a SIGBUS beyond the last page
1131                 *   extant in the file
1132                 */
1133                excess = phdr->p_memsz - phdr->p_filesz;
1134                excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1135
1136#ifdef CONFIG_MMU
1137                if (excess > excess1) {
1138                        unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1139                        unsigned long xmaddr;
1140
1141                        flags |= MAP_FIXED | MAP_ANONYMOUS;
1142                        down_write(&mm->mmap_sem);
1143                        xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1144                                         prot, flags, 0);
1145                        up_write(&mm->mmap_sem);
1146
1147                        kdebug("mmap[%d] <anon>"
1148                               " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1149                               loop, xaddr, excess - excess1, prot, flags,
1150                               xmaddr);
1151
1152                        if (xmaddr != xaddr)
1153                                return -ENOMEM;
1154                }
1155
1156                if (prot & PROT_WRITE && excess1 > 0) {
1157                        kdebug("clear[%d] ad=%lx sz=%lx",
1158                               loop, maddr + phdr->p_filesz, excess1);
1159                        clear_user((void __user *) maddr + phdr->p_filesz,
1160                                   excess1);
1161                }
1162
1163#else
1164                if (excess > 0) {
1165                        kdebug("clear[%d] ad=%lx sz=%lx",
1166                               loop, maddr + phdr->p_filesz, excess);
1167                        clear_user((void *) maddr + phdr->p_filesz, excess);
1168                }
1169#endif
1170
1171                if (mm) {
1172                        if (phdr->p_flags & PF_X) {
1173                                if (!mm->start_code) {
1174                                        mm->start_code = maddr;
1175                                        mm->end_code = maddr + phdr->p_memsz;
1176                                }
1177                        } else if (!mm->start_data) {
1178                                mm->start_data = maddr;
1179                                mm->end_data = maddr + phdr->p_memsz;
1180                        }
1181                }
1182
1183                seg++;
1184        }
1185
1186        return 0;
1187}
1188
1189/*****************************************************************************/
1190/*
1191 * ELF-FDPIC core dumper
1192 *
1193 * Modelled on fs/exec.c:aout_core_dump()
1194 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1195 *
1196 * Modelled on fs/binfmt_elf.c core dumper
1197 */
1198#if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1199
1200/*
1201 * These are the only things you should do on a core-file: use only these
1202 * functions to write out all the necessary info.
1203 */
1204static int dump_write(struct file *file, const void *addr, int nr)
1205{
1206        return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1207}
1208
1209static int dump_seek(struct file *file, loff_t off)
1210{
1211        if (file->f_op->llseek) {
1212                if (file->f_op->llseek(file, off, SEEK_SET) != off)
1213                        return 0;
1214        } else {
1215                file->f_pos = off;
1216        }
1217        return 1;
1218}
1219
1220/*
1221 * Decide whether a segment is worth dumping; default is yes to be
1222 * sure (missing info is worse than too much; etc).
1223 * Personally I'd include everything, and use the coredump limit...
1224 *
1225 * I think we should skip something. But I am not sure how. H.J.
1226 */
1227static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1228{
1229        int dump_ok;
1230
1231        /* Do not dump I/O mapped devices or special mappings */
1232        if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1233                kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1234                return 0;
1235        }
1236
1237        /* If we may not read the contents, don't allow us to dump
1238         * them either. "dump_write()" can't handle it anyway.
1239         */
1240        if (!(vma->vm_flags & VM_READ)) {
1241                kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1242                return 0;
1243        }
1244
1245        /* By default, dump shared memory if mapped from an anonymous file. */
1246        if (vma->vm_flags & VM_SHARED) {
1247                if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1248                        dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1249                        kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1250                               vma->vm_flags, dump_ok ? "yes" : "no");
1251                        return dump_ok;
1252                }
1253
1254                dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1255                kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1256                       vma->vm_flags, dump_ok ? "yes" : "no");
1257                return dump_ok;
1258        }
1259
1260#ifdef CONFIG_MMU
1261        /* By default, if it hasn't been written to, don't write it out */
1262        if (!vma->anon_vma) {
1263                dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1264                kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1265                       vma->vm_flags, dump_ok ? "yes" : "no");
1266                return dump_ok;
1267        }
1268#endif
1269
1270        dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1271        kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1272               dump_ok ? "yes" : "no");
1273        return dump_ok;
1274}
1275
1276/* An ELF note in memory */
1277struct memelfnote
1278{
1279        const char *name;
1280        int type;
1281        unsigned int datasz;
1282        void *data;
1283};
1284
1285static int notesize(struct memelfnote *en)
1286{
1287        int sz;
1288
1289        sz = sizeof(struct elf_note);
1290        sz += roundup(strlen(en->name) + 1, 4);
1291        sz += roundup(en->datasz, 4);
1292
1293        return sz;
1294}
1295
1296/* #define DEBUG */
1297
1298#define DUMP_WRITE(addr, nr)    \
1299        do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1300#define DUMP_SEEK(off)  \
1301        do { if (!dump_seek(file, (off))) return 0; } while(0)
1302
1303static int writenote(struct memelfnote *men, struct file *file)
1304{
1305        struct elf_note en;
1306
1307        en.n_namesz = strlen(men->name) + 1;
1308        en.n_descsz = men->datasz;
1309        en.n_type = men->type;
1310
1311        DUMP_WRITE(&en, sizeof(en));
1312        DUMP_WRITE(men->name, en.n_namesz);
1313        /* XXX - cast from long long to long to avoid need for libgcc.a */
1314        DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1315        DUMP_WRITE(men->data, men->datasz);
1316        DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1317
1318        return 1;
1319}
1320#undef DUMP_WRITE
1321#undef DUMP_SEEK
1322
1323#define DUMP_WRITE(addr, nr)    \
1324        if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1325                goto end_coredump;
1326#define DUMP_SEEK(off)  \
1327        if (!dump_seek(file, (off))) \
1328                goto end_coredump;
1329
1330static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1331{
1332        memcpy(elf->e_ident, ELFMAG, SELFMAG);
1333        elf->e_ident[EI_CLASS] = ELF_CLASS;
1334        elf->e_ident[EI_DATA] = ELF_DATA;
1335        elf->e_ident[EI_VERSION] = EV_CURRENT;
1336        elf->e_ident[EI_OSABI] = ELF_OSABI;
1337        memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1338
1339        elf->e_type = ET_CORE;
1340        elf->e_machine = ELF_ARCH;
1341        elf->e_version = EV_CURRENT;
1342        elf->e_entry = 0;
1343        elf->e_phoff = sizeof(struct elfhdr);
1344        elf->e_shoff = 0;
1345        elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1346        elf->e_ehsize = sizeof(struct elfhdr);
1347        elf->e_phentsize = sizeof(struct elf_phdr);
1348        elf->e_phnum = segs;
1349        elf->e_shentsize = 0;
1350        elf->e_shnum = 0;
1351        elf->e_shstrndx = 0;
1352        return;
1353}
1354
1355static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1356{
1357        phdr->p_type = PT_NOTE;
1358        phdr->p_offset = offset;
1359        phdr->p_vaddr = 0;
1360        phdr->p_paddr = 0;
1361        phdr->p_filesz = sz;
1362        phdr->p_memsz = 0;
1363        phdr->p_flags = 0;
1364        phdr->p_align = 0;
1365        return;
1366}
1367
1368static inline void fill_note(struct memelfnote *note, const char *name, int type,
1369                unsigned int sz, void *data)
1370{
1371        note->name = name;
1372        note->type = type;
1373        note->datasz = sz;
1374        note->data = data;
1375        return;
1376}
1377
1378/*
1379 * fill up all the fields in prstatus from the given task struct, except
1380 * registers which need to be filled up seperately.
1381 */
1382static void fill_prstatus(struct elf_prstatus *prstatus,
1383                          struct task_struct *p, long signr)
1384{
1385        prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1386        prstatus->pr_sigpend = p->pending.signal.sig[0];
1387        prstatus->pr_sighold = p->blocked.sig[0];
1388        prstatus->pr_pid = task_pid_vnr(p);
1389        prstatus->pr_ppid = task_pid_vnr(p->parent);
1390        prstatus->pr_pgrp = task_pgrp_vnr(p);
1391        prstatus->pr_sid = task_session_vnr(p);
1392        if (thread_group_leader(p)) {
1393                struct task_cputime cputime;
1394
1395                /*
1396                 * This is the record for the group leader.  It shows the
1397                 * group-wide total, not its individual thread total.
1398                 */
1399                thread_group_cputime(p, &cputime);
1400                cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1401                cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1402        } else {
1403                cputime_to_timeval(p->utime, &prstatus->pr_utime);
1404                cputime_to_timeval(p->stime, &prstatus->pr_stime);
1405        }
1406        cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1407        cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1408
1409        prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1410        prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1411}
1412
1413static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1414                       struct mm_struct *mm)
1415{
1416        unsigned int i, len;
1417
1418        /* first copy the parameters from user space */
1419        memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1420
1421        len = mm->arg_end - mm->arg_start;
1422        if (len >= ELF_PRARGSZ)
1423                len = ELF_PRARGSZ - 1;
1424        if (copy_from_user(&psinfo->pr_psargs,
1425                           (const char __user *) mm->arg_start, len))
1426                return -EFAULT;
1427        for (i = 0; i < len; i++)
1428                if (psinfo->pr_psargs[i] == 0)
1429                        psinfo->pr_psargs[i] = ' ';
1430        psinfo->pr_psargs[len] = 0;
1431
1432        psinfo->pr_pid = task_pid_vnr(p);
1433        psinfo->pr_ppid = task_pid_vnr(p->parent);
1434        psinfo->pr_pgrp = task_pgrp_vnr(p);
1435        psinfo->pr_sid = task_session_vnr(p);
1436
1437        i = p->state ? ffz(~p->state) + 1 : 0;
1438        psinfo->pr_state = i;
1439        psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1440        psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1441        psinfo->pr_nice = task_nice(p);
1442        psinfo->pr_flag = p->flags;
1443        SET_UID(psinfo->pr_uid, p->uid);
1444        SET_GID(psinfo->pr_gid, p->gid);
1445        strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1446
1447        return 0;
1448}
1449
1450/* Here is the structure in which status of each thread is captured. */
1451struct elf_thread_status
1452{
1453        struct list_head list;
1454        struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1455        elf_fpregset_t fpu;             /* NT_PRFPREG */
1456        struct task_struct *thread;
1457#ifdef ELF_CORE_COPY_XFPREGS
1458        elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1459#endif
1460        struct memelfnote notes[3];
1461        int num_notes;
1462};
1463
1464/*
1465 * In order to add the specific thread information for the elf file format,
1466 * we need to keep a linked list of every thread's pr_status and then create
1467 * a single section for them in the final core file.
1468 */
1469static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1470{
1471        struct task_struct *p = t->thread;
1472        int sz = 0;
1473
1474        t->num_notes = 0;
1475
1476        fill_prstatus(&t->prstatus, p, signr);
1477        elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1478
1479        fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1480                  &t->prstatus);
1481        t->num_notes++;
1482        sz += notesize(&t->notes[0]);
1483
1484        t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1485        if (t->prstatus.pr_fpvalid) {
1486                fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1487                          &t->fpu);
1488                t->num_notes++;
1489                sz += notesize(&t->notes[1]);
1490        }
1491
1492#ifdef ELF_CORE_COPY_XFPREGS
1493        if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1494                fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1495                          sizeof(t->xfpu), &t->xfpu);
1496                t->num_notes++;
1497                sz += notesize(&t->notes[2]);
1498        }
1499#endif
1500        return sz;
1501}
1502
1503/*
1504 * dump the segments for an MMU process
1505 */
1506#ifdef CONFIG_MMU
1507static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1508                           unsigned long *limit, unsigned long mm_flags)
1509{
1510        struct vm_area_struct *vma;
1511
1512        for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1513                unsigned long addr;
1514
1515                if (!maydump(vma, mm_flags))
1516                        continue;
1517
1518                for (addr = vma->vm_start;
1519                     addr < vma->vm_end;
1520                     addr += PAGE_SIZE
1521                     ) {
1522                        struct vm_area_struct *vma;
1523                        struct page *page;
1524
1525                        if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1526                                           &page, &vma) <= 0) {
1527                                DUMP_SEEK(file->f_pos + PAGE_SIZE);
1528                        }
1529                        else if (page == ZERO_PAGE(0)) {
1530                                page_cache_release(page);
1531                                DUMP_SEEK(file->f_pos + PAGE_SIZE);
1532                        }
1533                        else {
1534                                void *kaddr;
1535
1536                                flush_cache_page(vma, addr, page_to_pfn(page));
1537                                kaddr = kmap(page);
1538                                if ((*size += PAGE_SIZE) > *limit ||
1539                                    !dump_write(file, kaddr, PAGE_SIZE)
1540                                    ) {
1541                                        kunmap(page);
1542                                        page_cache_release(page);
1543                                        return -EIO;
1544                                }
1545                                kunmap(page);
1546                                page_cache_release(page);
1547                        }
1548                }
1549        }
1550
1551        return 0;
1552
1553end_coredump:
1554        return -EFBIG;
1555}
1556#endif
1557
1558/*
1559 * dump the segments for a NOMMU process
1560 */
1561#ifndef CONFIG_MMU
1562static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1563                           unsigned long *limit, unsigned long mm_flags)
1564{
1565        struct vm_list_struct *vml;
1566
1567        for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1568        struct vm_area_struct *vma = vml->vma;
1569
1570                if (!maydump(vma, mm_flags))
1571                        continue;
1572
1573                if ((*size += PAGE_SIZE) > *limit)
1574                        return -EFBIG;
1575
1576                if (!dump_write(file, (void *) vma->vm_start,
1577                                vma->vm_end - vma->vm_start))
1578                        return -EIO;
1579        }
1580
1581        return 0;
1582}
1583#endif
1584
1585/*
1586 * Actual dumper
1587 *
1588 * This is a two-pass process; first we find the offsets of the bits,
1589 * and then they are actually written out.  If we run out of core limit
1590 * we just truncate.
1591 */
1592static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1593                               struct file *file, unsigned long limit)
1594{
1595#define NUM_NOTES       6
1596        int has_dumped = 0;
1597        mm_segment_t fs;
1598        int segs;
1599        size_t size = 0;
1600        int i;
1601        struct vm_area_struct *vma;
1602        struct elfhdr *elf = NULL;
1603        loff_t offset = 0, dataoff;
1604        int numnote;
1605        struct memelfnote *notes = NULL;
1606        struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1607        struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1608        LIST_HEAD(thread_list);
1609        struct list_head *t;
1610        elf_fpregset_t *fpu = NULL;
1611#ifdef ELF_CORE_COPY_XFPREGS
1612        elf_fpxregset_t *xfpu = NULL;
1613#endif
1614        int thread_status_size = 0;
1615#ifndef CONFIG_MMU
1616        struct vm_list_struct *vml;
1617#endif
1618        elf_addr_t *auxv;
1619        unsigned long mm_flags;
1620
1621        /*
1622         * We no longer stop all VM operations.
1623         *
1624         * This is because those proceses that could possibly change map_count
1625         * or the mmap / vma pages are now blocked in do_exit on current
1626         * finishing this core dump.
1627         *
1628         * Only ptrace can touch these memory addresses, but it doesn't change
1629         * the map_count or the pages allocated. So no possibility of crashing
1630         * exists while dumping the mm->vm_next areas to the core file.
1631         */
1632
1633        /* alloc memory for large data structures: too large to be on stack */
1634        elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1635        if (!elf)
1636                goto cleanup;
1637        prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1638        if (!prstatus)
1639                goto cleanup;
1640        psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1641        if (!psinfo)
1642                goto cleanup;
1643        notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1644        if (!notes)
1645                goto cleanup;
1646        fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1647        if (!fpu)
1648                goto cleanup;
1649#ifdef ELF_CORE_COPY_XFPREGS
1650        xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1651        if (!xfpu)
1652                goto cleanup;
1653#endif
1654
1655        if (signr) {
1656                struct core_thread *ct;
1657                struct elf_thread_status *tmp;
1658
1659                for (ct = current->mm->core_state->dumper.next;
1660                                                ct; ct = ct->next) {
1661                        tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1662                        if (!tmp)
1663                                goto cleanup;
1664
1665                        tmp->thread = ct->task;
1666                        list_add(&tmp->list, &thread_list);
1667                }
1668
1669                list_for_each(t, &thread_list) {
1670                        struct elf_thread_status *tmp;
1671                        int sz;
1672
1673                        tmp = list_entry(t, struct elf_thread_status, list);
1674                        sz = elf_dump_thread_status(signr, tmp);
1675                        thread_status_size += sz;
1676                }
1677        }
1678
1679        /* now collect the dump for the current */
1680        fill_prstatus(prstatus, current, signr);
1681        elf_core_copy_regs(&prstatus->pr_reg, regs);
1682
1683#ifdef CONFIG_MMU
1684        segs = current->mm->map_count;
1685#else
1686        segs = 0;
1687        for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1688            segs++;
1689#endif
1690#ifdef ELF_CORE_EXTRA_PHDRS
1691        segs += ELF_CORE_EXTRA_PHDRS;
1692#endif
1693
1694        /* Set up header */
1695        fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1696
1697        has_dumped = 1;
1698        current->flags |= PF_DUMPCORE;
1699
1700        /*
1701         * Set up the notes in similar form to SVR4 core dumps made
1702         * with info from their /proc.
1703         */
1704
1705        fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1706        fill_psinfo(psinfo, current->group_leader, current->mm);
1707        fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1708
1709        numnote = 2;
1710
1711        auxv = (elf_addr_t *) current->mm->saved_auxv;
1712
1713        i = 0;
1714        do
1715                i += 2;
1716        while (auxv[i - 2] != AT_NULL);
1717        fill_note(&notes[numnote++], "CORE", NT_AUXV,
1718                  i * sizeof(elf_addr_t), auxv);
1719
1720        /* Try to dump the FPU. */
1721        if ((prstatus->pr_fpvalid =
1722             elf_core_copy_task_fpregs(current, regs, fpu)))
1723                fill_note(notes + numnote++,
1724                          "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1725#ifdef ELF_CORE_COPY_XFPREGS
1726        if (elf_core_copy_task_xfpregs(current, xfpu))
1727                fill_note(notes + numnote++,
1728                          "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1729#endif
1730
1731        fs = get_fs();
1732        set_fs(KERNEL_DS);
1733
1734        DUMP_WRITE(elf, sizeof(*elf));
1735        offset += sizeof(*elf);                         /* Elf header */
1736        offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1737
1738        /* Write notes phdr entry */
1739        {
1740                struct elf_phdr phdr;
1741                int sz = 0;
1742
1743                for (i = 0; i < numnote; i++)
1744                        sz += notesize(notes + i);
1745
1746                sz += thread_status_size;
1747
1748                fill_elf_note_phdr(&phdr, sz, offset);
1749                offset += sz;
1750                DUMP_WRITE(&phdr, sizeof(phdr));
1751        }
1752
1753        /* Page-align dumped data */
1754        dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1755
1756        /*
1757         * We must use the same mm->flags while dumping core to avoid
1758         * inconsistency between the program headers and bodies, otherwise an
1759         * unusable core file can be generated.
1760         */
1761        mm_flags = current->mm->flags;
1762
1763        /* write program headers for segments dump */
1764        for (
1765#ifdef CONFIG_MMU
1766                vma = current->mm->mmap; vma; vma = vma->vm_next
1767#else
1768                        vml = current->mm->context.vmlist; vml; vml = vml->next
1769#endif
1770             ) {
1771                struct elf_phdr phdr;
1772                size_t sz;
1773
1774#ifndef CONFIG_MMU
1775                vma = vml->vma;
1776#endif
1777
1778                sz = vma->vm_end - vma->vm_start;
1779
1780                phdr.p_type = PT_LOAD;
1781                phdr.p_offset = offset;
1782                phdr.p_vaddr = vma->vm_start;
1783                phdr.p_paddr = 0;
1784                phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1785                phdr.p_memsz = sz;
1786                offset += phdr.p_filesz;
1787                phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1788                if (vma->vm_flags & VM_WRITE)
1789                        phdr.p_flags |= PF_W;
1790                if (vma->vm_flags & VM_EXEC)
1791                        phdr.p_flags |= PF_X;
1792                phdr.p_align = ELF_EXEC_PAGESIZE;
1793
1794                DUMP_WRITE(&phdr, sizeof(phdr));
1795        }
1796
1797#ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1798        ELF_CORE_WRITE_EXTRA_PHDRS;
1799#endif
1800
1801        /* write out the notes section */
1802        for (i = 0; i < numnote; i++)
1803                if (!writenote(notes + i, file))
1804                        goto end_coredump;
1805
1806        /* write out the thread status notes section */
1807        list_for_each(t, &thread_list) {
1808                struct elf_thread_status *tmp =
1809                                list_entry(t, struct elf_thread_status, list);
1810
1811                for (i = 0; i < tmp->num_notes; i++)
1812                        if (!writenote(&tmp->notes[i], file))
1813                                goto end_coredump;
1814        }
1815
1816        DUMP_SEEK(dataoff);
1817
1818        if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1819                goto end_coredump;
1820
1821#ifdef ELF_CORE_WRITE_EXTRA_DATA
1822        ELF_CORE_WRITE_EXTRA_DATA;
1823#endif
1824
1825        if (file->f_pos != offset) {
1826                /* Sanity check */
1827                printk(KERN_WARNING
1828                       "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1829                       file->f_pos, offset);
1830        }
1831
1832end_coredump:
1833        set_fs(fs);
1834
1835cleanup:
1836        while (!list_empty(&thread_list)) {
1837                struct list_head *tmp = thread_list.next;
1838                list_del(tmp);
1839                kfree(list_entry(tmp, struct elf_thread_status, list));
1840        }
1841
1842        kfree(elf);
1843        kfree(prstatus);
1844        kfree(psinfo);
1845        kfree(notes);
1846        kfree(fpu);
1847#ifdef ELF_CORE_COPY_XFPREGS
1848        kfree(xfpu);
1849#endif
1850        return has_dumped;
1851#undef NUM_NOTES
1852}
1853
1854#endif          /* USE_ELF_CORE_DUMP */
1855