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#include <linux/coredump.h>
  38
  39#include <asm/uaccess.h>
  40#include <asm/param.h>
  41#include <asm/pgalloc.h>
  42#include <asm/exec.h>
  43
  44typedef char *elf_caddr_t;
  45
  46#if 0
  47#define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  48#else
  49#define kdebug(fmt, ...) do {} while(0)
  50#endif
  51
  52#if 0
  53#define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  54#else
  55#define kdcore(fmt, ...) do {} while(0)
  56#endif
  57
  58MODULE_LICENSE("GPL");
  59
  60static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
  61static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  62static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  63                              struct mm_struct *, const char *);
  64
  65static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  66                                   struct elf_fdpic_params *,
  67                                   struct elf_fdpic_params *);
  68
  69#ifndef CONFIG_MMU
  70static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
  71                                            unsigned long *);
  72static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  73                                                   struct file *,
  74                                                   struct mm_struct *);
  75#endif
  76
  77static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  78                                             struct file *, struct mm_struct *);
  79
  80#ifdef CONFIG_ELF_CORE
  81static int elf_fdpic_core_dump(struct coredump_params *cprm);
  82#endif
  83
  84static struct linux_binfmt elf_fdpic_format = {
  85        .module         = THIS_MODULE,
  86        .load_binary    = load_elf_fdpic_binary,
  87#ifdef CONFIG_ELF_CORE
  88        .core_dump      = elf_fdpic_core_dump,
  89#endif
  90        .min_coredump   = ELF_EXEC_PAGESIZE,
  91};
  92
  93static int __init init_elf_fdpic_binfmt(void)
  94{
  95        register_binfmt(&elf_fdpic_format);
  96        return 0;
  97}
  98
  99static void __exit exit_elf_fdpic_binfmt(void)
 100{
 101        unregister_binfmt(&elf_fdpic_format);
 102}
 103
 104core_initcall(init_elf_fdpic_binfmt);
 105module_exit(exit_elf_fdpic_binfmt);
 106
 107static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
 108{
 109        if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 110                return 0;
 111        if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 112                return 0;
 113        if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
 114                return 0;
 115        if (!file->f_op || !file->f_op->mmap)
 116                return 0;
 117        return 1;
 118}
 119
 120/*****************************************************************************/
 121/*
 122 * read the program headers table into memory
 123 */
 124static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 125                                 struct file *file)
 126{
 127        struct elf32_phdr *phdr;
 128        unsigned long size;
 129        int retval, loop;
 130
 131        if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 132                return -ENOMEM;
 133        if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 134                return -ENOMEM;
 135
 136        size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 137        params->phdrs = kmalloc(size, GFP_KERNEL);
 138        if (!params->phdrs)
 139                return -ENOMEM;
 140
 141        retval = kernel_read(file, params->hdr.e_phoff,
 142                             (char *) params->phdrs, size);
 143        if (unlikely(retval != size))
 144                return retval < 0 ? retval : -ENOEXEC;
 145
 146        /* determine stack size for this binary */
 147        phdr = params->phdrs;
 148        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 149                if (phdr->p_type != PT_GNU_STACK)
 150                        continue;
 151
 152                if (phdr->p_flags & PF_X)
 153                        params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 154                else
 155                        params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 156
 157                params->stack_size = phdr->p_memsz;
 158                break;
 159        }
 160
 161        return 0;
 162}
 163
 164/*****************************************************************************/
 165/*
 166 * load an fdpic binary into various bits of memory
 167 */
 168static int load_elf_fdpic_binary(struct linux_binprm *bprm,
 169                                 struct pt_regs *regs)
 170{
 171        struct elf_fdpic_params exec_params, interp_params;
 172        struct elf_phdr *phdr;
 173        unsigned long stack_size, entryaddr;
 174#ifdef ELF_FDPIC_PLAT_INIT
 175        unsigned long dynaddr;
 176#endif
 177#ifndef CONFIG_MMU
 178        unsigned long stack_prot;
 179#endif
 180        struct file *interpreter = NULL; /* to shut gcc up */
 181        char *interpreter_name = NULL;
 182        int executable_stack;
 183        int retval, i;
 184
 185        kdebug("____ LOAD %d ____", current->pid);
 186
 187        memset(&exec_params, 0, sizeof(exec_params));
 188        memset(&interp_params, 0, sizeof(interp_params));
 189
 190        exec_params.hdr = *(struct elfhdr *) bprm->buf;
 191        exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 192
 193        /* check that this is a binary we know how to deal with */
 194        retval = -ENOEXEC;
 195        if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
 196                goto error;
 197
 198        /* read the program header table */
 199        retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 200        if (retval < 0)
 201                goto error;
 202
 203        /* scan for a program header that specifies an interpreter */
 204        phdr = exec_params.phdrs;
 205
 206        for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 207                switch (phdr->p_type) {
 208                case PT_INTERP:
 209                        retval = -ENOMEM;
 210                        if (phdr->p_filesz > PATH_MAX)
 211                                goto error;
 212                        retval = -ENOENT;
 213                        if (phdr->p_filesz < 2)
 214                                goto error;
 215
 216                        /* read the name of the interpreter into memory */
 217                        interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 218                        if (!interpreter_name)
 219                                goto error;
 220
 221                        retval = kernel_read(bprm->file,
 222                                             phdr->p_offset,
 223                                             interpreter_name,
 224                                             phdr->p_filesz);
 225                        if (unlikely(retval != phdr->p_filesz)) {
 226                                if (retval >= 0)
 227                                        retval = -ENOEXEC;
 228                                goto error;
 229                        }
 230
 231                        retval = -ENOENT;
 232                        if (interpreter_name[phdr->p_filesz - 1] != '\0')
 233                                goto error;
 234
 235                        kdebug("Using ELF interpreter %s", interpreter_name);
 236
 237                        /* replace the program with the interpreter */
 238                        interpreter = open_exec(interpreter_name);
 239                        retval = PTR_ERR(interpreter);
 240                        if (IS_ERR(interpreter)) {
 241                                interpreter = NULL;
 242                                goto error;
 243                        }
 244
 245                        /*
 246                         * If the binary is not readable then enforce
 247                         * mm->dumpable = 0 regardless of the interpreter's
 248                         * permissions.
 249                         */
 250                        would_dump(bprm, interpreter);
 251
 252                        retval = kernel_read(interpreter, 0, bprm->buf,
 253                                             BINPRM_BUF_SIZE);
 254                        if (unlikely(retval != BINPRM_BUF_SIZE)) {
 255                                if (retval >= 0)
 256                                        retval = -ENOEXEC;
 257                                goto error;
 258                        }
 259
 260                        interp_params.hdr = *((struct elfhdr *) bprm->buf);
 261                        break;
 262
 263                case PT_LOAD:
 264#ifdef CONFIG_MMU
 265                        if (exec_params.load_addr == 0)
 266                                exec_params.load_addr = phdr->p_vaddr;
 267#endif
 268                        break;
 269                }
 270
 271        }
 272
 273        if (elf_check_const_displacement(&exec_params.hdr))
 274                exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 275
 276        /* perform insanity checks on the interpreter */
 277        if (interpreter_name) {
 278                retval = -ELIBBAD;
 279                if (!is_elf_fdpic(&interp_params.hdr, interpreter))
 280                        goto error;
 281
 282                interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 283
 284                /* read the interpreter's program header table */
 285                retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 286                if (retval < 0)
 287                        goto error;
 288        }
 289
 290        stack_size = exec_params.stack_size;
 291        if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 292                executable_stack = EXSTACK_ENABLE_X;
 293        else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 294                executable_stack = EXSTACK_DISABLE_X;
 295        else
 296                executable_stack = EXSTACK_DEFAULT;
 297
 298        if (stack_size == 0) {
 299                stack_size = interp_params.stack_size;
 300                if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 301                        executable_stack = EXSTACK_ENABLE_X;
 302                else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 303                        executable_stack = EXSTACK_DISABLE_X;
 304                else
 305                        executable_stack = EXSTACK_DEFAULT;
 306        }
 307
 308        retval = -ENOEXEC;
 309        if (stack_size == 0)
 310                goto error;
 311
 312        if (elf_check_const_displacement(&interp_params.hdr))
 313                interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 314
 315        /* flush all traces of the currently running executable */
 316        retval = flush_old_exec(bprm);
 317        if (retval)
 318                goto error;
 319
 320        /* there's now no turning back... the old userspace image is dead,
 321         * defunct, deceased, etc. after this point we have to exit via
 322         * error_kill */
 323        set_personality(PER_LINUX_FDPIC);
 324        if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
 325                current->personality |= READ_IMPLIES_EXEC;
 326
 327        setup_new_exec(bprm);
 328
 329        set_binfmt(&elf_fdpic_format);
 330
 331        current->mm->start_code = 0;
 332        current->mm->end_code = 0;
 333        current->mm->start_stack = 0;
 334        current->mm->start_data = 0;
 335        current->mm->end_data = 0;
 336        current->mm->context.exec_fdpic_loadmap = 0;
 337        current->mm->context.interp_fdpic_loadmap = 0;
 338
 339#ifdef CONFIG_MMU
 340        elf_fdpic_arch_lay_out_mm(&exec_params,
 341                                  &interp_params,
 342                                  &current->mm->start_stack,
 343                                  &current->mm->start_brk);
 344
 345        retval = setup_arg_pages(bprm, current->mm->start_stack,
 346                                 executable_stack);
 347        if (retval < 0) {
 348                send_sig(SIGKILL, current, 0);
 349                goto error_kill;
 350        }
 351#endif
 352
 353        /* load the executable and interpreter into memory */
 354        retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 355                                    "executable");
 356        if (retval < 0)
 357                goto error_kill;
 358
 359        if (interpreter_name) {
 360                retval = elf_fdpic_map_file(&interp_params, interpreter,
 361                                            current->mm, "interpreter");
 362                if (retval < 0) {
 363                        printk(KERN_ERR "Unable to load interpreter\n");
 364                        goto error_kill;
 365                }
 366
 367                allow_write_access(interpreter);
 368                fput(interpreter);
 369                interpreter = NULL;
 370        }
 371
 372#ifdef CONFIG_MMU
 373        if (!current->mm->start_brk)
 374                current->mm->start_brk = current->mm->end_data;
 375
 376        current->mm->brk = current->mm->start_brk =
 377                PAGE_ALIGN(current->mm->start_brk);
 378
 379#else
 380        /* create a stack and brk area big enough for everyone
 381         * - the brk heap starts at the bottom and works up
 382         * - the stack starts at the top and works down
 383         */
 384        stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 385        if (stack_size < PAGE_SIZE * 2)
 386                stack_size = PAGE_SIZE * 2;
 387
 388        stack_prot = PROT_READ | PROT_WRITE;
 389        if (executable_stack == EXSTACK_ENABLE_X ||
 390            (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 391                stack_prot |= PROT_EXEC;
 392
 393        current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 394                                         MAP_PRIVATE | MAP_ANONYMOUS |
 395                                         MAP_UNINITIALIZED | MAP_GROWSDOWN,
 396                                         0);
 397
 398        if (IS_ERR_VALUE(current->mm->start_brk)) {
 399                retval = current->mm->start_brk;
 400                current->mm->start_brk = 0;
 401                goto error_kill;
 402        }
 403
 404        current->mm->brk = current->mm->start_brk;
 405        current->mm->context.end_brk = current->mm->start_brk;
 406        current->mm->context.end_brk +=
 407                (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 408        current->mm->start_stack = current->mm->start_brk + stack_size;
 409#endif
 410
 411        install_exec_creds(bprm);
 412        if (create_elf_fdpic_tables(bprm, current->mm,
 413                                    &exec_params, &interp_params) < 0)
 414                goto error_kill;
 415
 416        kdebug("- start_code  %lx", current->mm->start_code);
 417        kdebug("- end_code    %lx", current->mm->end_code);
 418        kdebug("- start_data  %lx", current->mm->start_data);
 419        kdebug("- end_data    %lx", current->mm->end_data);
 420        kdebug("- start_brk   %lx", current->mm->start_brk);
 421        kdebug("- brk         %lx", current->mm->brk);
 422        kdebug("- start_stack %lx", current->mm->start_stack);
 423
 424#ifdef ELF_FDPIC_PLAT_INIT
 425        /*
 426         * The ABI may specify that certain registers be set up in special
 427         * ways (on i386 %edx is the address of a DT_FINI function, for
 428         * example.  This macro performs whatever initialization to
 429         * the regs structure is required.
 430         */
 431        dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 432        ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 433                            dynaddr);
 434#endif
 435
 436        /* everything is now ready... get the userspace context ready to roll */
 437        entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 438        start_thread(regs, entryaddr, current->mm->start_stack);
 439
 440        retval = 0;
 441
 442error:
 443        if (interpreter) {
 444                allow_write_access(interpreter);
 445                fput(interpreter);
 446        }
 447        kfree(interpreter_name);
 448        kfree(exec_params.phdrs);
 449        kfree(exec_params.loadmap);
 450        kfree(interp_params.phdrs);
 451        kfree(interp_params.loadmap);
 452        return retval;
 453
 454        /* unrecoverable error - kill the process */
 455error_kill:
 456        send_sig(SIGSEGV, current, 0);
 457        goto error;
 458
 459}
 460
 461/*****************************************************************************/
 462
 463#ifndef ELF_BASE_PLATFORM
 464/*
 465 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 466 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 467 * will be copied to the user stack in the same manner as AT_PLATFORM.
 468 */
 469#define ELF_BASE_PLATFORM NULL
 470#endif
 471
 472/*
 473 * present useful information to the program by shovelling it onto the new
 474 * process's stack
 475 */
 476static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 477                                   struct mm_struct *mm,
 478                                   struct elf_fdpic_params *exec_params,
 479                                   struct elf_fdpic_params *interp_params)
 480{
 481        const struct cred *cred = current_cred();
 482        unsigned long sp, csp, nitems;
 483        elf_caddr_t __user *argv, *envp;
 484        size_t platform_len = 0, len;
 485        char *k_platform, *k_base_platform;
 486        char __user *u_platform, *u_base_platform, *p;
 487        long hwcap;
 488        int loop;
 489        int nr; /* reset for each csp adjustment */
 490
 491#ifdef CONFIG_MMU
 492        /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 493         * by the processes running on the same package. One thing we can do is
 494         * to shuffle the initial stack for them, so we give the architecture
 495         * an opportunity to do so here.
 496         */
 497        sp = arch_align_stack(bprm->p);
 498#else
 499        sp = mm->start_stack;
 500
 501        /* stack the program arguments and environment */
 502        if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 503                return -EFAULT;
 504#endif
 505
 506        hwcap = ELF_HWCAP;
 507
 508        /*
 509         * If this architecture has a platform capability string, copy it
 510         * to userspace.  In some cases (Sparc), this info is impossible
 511         * for userspace to get any other way, in others (i386) it is
 512         * merely difficult.
 513         */
 514        k_platform = ELF_PLATFORM;
 515        u_platform = NULL;
 516
 517        if (k_platform) {
 518                platform_len = strlen(k_platform) + 1;
 519                sp -= platform_len;
 520                u_platform = (char __user *) sp;
 521                if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 522                        return -EFAULT;
 523        }
 524
 525        /*
 526         * If this architecture has a "base" platform capability
 527         * string, copy it to userspace.
 528         */
 529        k_base_platform = ELF_BASE_PLATFORM;
 530        u_base_platform = NULL;
 531
 532        if (k_base_platform) {
 533                platform_len = strlen(k_base_platform) + 1;
 534                sp -= platform_len;
 535                u_base_platform = (char __user *) sp;
 536                if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 537                        return -EFAULT;
 538        }
 539
 540        sp &= ~7UL;
 541
 542        /* stack the load map(s) */
 543        len = sizeof(struct elf32_fdpic_loadmap);
 544        len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 545        sp = (sp - len) & ~7UL;
 546        exec_params->map_addr = sp;
 547
 548        if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 549                return -EFAULT;
 550
 551        current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 552
 553        if (interp_params->loadmap) {
 554                len = sizeof(struct elf32_fdpic_loadmap);
 555                len += sizeof(struct elf32_fdpic_loadseg) *
 556                        interp_params->loadmap->nsegs;
 557                sp = (sp - len) & ~7UL;
 558                interp_params->map_addr = sp;
 559
 560                if (copy_to_user((void __user *) sp, interp_params->loadmap,
 561                                 len) != 0)
 562                        return -EFAULT;
 563
 564                current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 565        }
 566
 567        /* force 16 byte _final_ alignment here for generality */
 568#define DLINFO_ITEMS 15
 569
 570        nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 571                (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 572
 573        if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
 574                nitems++;
 575
 576        csp = sp;
 577        sp -= nitems * 2 * sizeof(unsigned long);
 578        sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 579        sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 580        sp -= 1 * sizeof(unsigned long);                /* argc */
 581
 582        csp -= sp & 15UL;
 583        sp -= sp & 15UL;
 584
 585        /* put the ELF interpreter info on the stack */
 586#define NEW_AUX_ENT(id, val)                                            \
 587        do {                                                            \
 588                struct { unsigned long _id, _val; } __user *ent;        \
 589                                                                        \
 590                ent = (void __user *) csp;                              \
 591                __put_user((id), &ent[nr]._id);                         \
 592                __put_user((val), &ent[nr]._val);                       \
 593                nr++;                                                   \
 594        } while (0)
 595
 596        nr = 0;
 597        csp -= 2 * sizeof(unsigned long);
 598        NEW_AUX_ENT(AT_NULL, 0);
 599        if (k_platform) {
 600                nr = 0;
 601                csp -= 2 * sizeof(unsigned long);
 602                NEW_AUX_ENT(AT_PLATFORM,
 603                            (elf_addr_t) (unsigned long) u_platform);
 604        }
 605
 606        if (k_base_platform) {
 607                nr = 0;
 608                csp -= 2 * sizeof(unsigned long);
 609                NEW_AUX_ENT(AT_BASE_PLATFORM,
 610                            (elf_addr_t) (unsigned long) u_base_platform);
 611        }
 612
 613        if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 614                nr = 0;
 615                csp -= 2 * sizeof(unsigned long);
 616                NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 617        }
 618
 619        nr = 0;
 620        csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 621        NEW_AUX_ENT(AT_HWCAP,   hwcap);
 622        NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 623        NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 624        NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 625        NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 626        NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 627        NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 628        NEW_AUX_ENT(AT_FLAGS,   0);
 629        NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 630        NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 631        NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 632        NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 633        NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 634        NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
 635        NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 636
 637#ifdef ARCH_DLINFO
 638        nr = 0;
 639        csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 640
 641        /* ARCH_DLINFO must come last so platform specific code can enforce
 642         * special alignment requirements on the AUXV if necessary (eg. PPC).
 643         */
 644        ARCH_DLINFO;
 645#endif
 646#undef NEW_AUX_ENT
 647
 648        /* allocate room for argv[] and envv[] */
 649        csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 650        envp = (elf_caddr_t __user *) csp;
 651        csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 652        argv = (elf_caddr_t __user *) csp;
 653
 654        /* stack argc */
 655        csp -= sizeof(unsigned long);
 656        __put_user(bprm->argc, (unsigned long __user *) csp);
 657
 658        BUG_ON(csp != sp);
 659
 660        /* fill in the argv[] array */
 661#ifdef CONFIG_MMU
 662        current->mm->arg_start = bprm->p;
 663#else
 664        current->mm->arg_start = current->mm->start_stack -
 665                (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 666#endif
 667
 668        p = (char __user *) current->mm->arg_start;
 669        for (loop = bprm->argc; loop > 0; loop--) {
 670                __put_user((elf_caddr_t) p, argv++);
 671                len = strnlen_user(p, MAX_ARG_STRLEN);
 672                if (!len || len > MAX_ARG_STRLEN)
 673                        return -EINVAL;
 674                p += len;
 675        }
 676        __put_user(NULL, argv);
 677        current->mm->arg_end = (unsigned long) p;
 678
 679        /* fill in the envv[] array */
 680        current->mm->env_start = (unsigned long) p;
 681        for (loop = bprm->envc; loop > 0; loop--) {
 682                __put_user((elf_caddr_t)(unsigned long) p, envp++);
 683                len = strnlen_user(p, MAX_ARG_STRLEN);
 684                if (!len || len > MAX_ARG_STRLEN)
 685                        return -EINVAL;
 686                p += len;
 687        }
 688        __put_user(NULL, envp);
 689        current->mm->env_end = (unsigned long) p;
 690
 691        mm->start_stack = (unsigned long) sp;
 692        return 0;
 693}
 694
 695/*****************************************************************************/
 696/*
 697 * transfer the program arguments and environment from the holding pages onto
 698 * the stack
 699 */
 700#ifndef CONFIG_MMU
 701static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 702                                            unsigned long *_sp)
 703{
 704        unsigned long index, stop, sp;
 705        char *src;
 706        int ret = 0;
 707
 708        stop = bprm->p >> PAGE_SHIFT;
 709        sp = *_sp;
 710
 711        for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 712                src = kmap(bprm->page[index]);
 713                sp -= PAGE_SIZE;
 714                if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 715                        ret = -EFAULT;
 716                kunmap(bprm->page[index]);
 717                if (ret < 0)
 718                        goto out;
 719        }
 720
 721        *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 722
 723out:
 724        return ret;
 725}
 726#endif
 727
 728/*****************************************************************************/
 729/*
 730 * load the appropriate binary image (executable or interpreter) into memory
 731 * - we assume no MMU is available
 732 * - if no other PIC bits are set in params->hdr->e_flags
 733 *   - we assume that the LOADable segments in the binary are independently relocatable
 734 *   - we assume R/O executable segments are shareable
 735 * - else
 736 *   - we assume the loadable parts of the image to require fixed displacement
 737 *   - the image is not shareable
 738 */
 739static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 740                              struct file *file,
 741                              struct mm_struct *mm,
 742                              const char *what)
 743{
 744        struct elf32_fdpic_loadmap *loadmap;
 745#ifdef CONFIG_MMU
 746        struct elf32_fdpic_loadseg *mseg;
 747#endif
 748        struct elf32_fdpic_loadseg *seg;
 749        struct elf32_phdr *phdr;
 750        unsigned long load_addr, stop;
 751        unsigned nloads, tmp;
 752        size_t size;
 753        int loop, ret;
 754
 755        /* allocate a load map table */
 756        nloads = 0;
 757        for (loop = 0; loop < params->hdr.e_phnum; loop++)
 758                if (params->phdrs[loop].p_type == PT_LOAD)
 759                        nloads++;
 760
 761        if (nloads == 0)
 762                return -ELIBBAD;
 763
 764        size = sizeof(*loadmap) + nloads * sizeof(*seg);
 765        loadmap = kzalloc(size, GFP_KERNEL);
 766        if (!loadmap)
 767                return -ENOMEM;
 768
 769        params->loadmap = loadmap;
 770
 771        loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 772        loadmap->nsegs = nloads;
 773
 774        load_addr = params->load_addr;
 775        seg = loadmap->segs;
 776
 777        /* map the requested LOADs into the memory space */
 778        switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 779        case ELF_FDPIC_FLAG_CONSTDISP:
 780        case ELF_FDPIC_FLAG_CONTIGUOUS:
 781#ifndef CONFIG_MMU
 782                ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 783                if (ret < 0)
 784                        return ret;
 785                break;
 786#endif
 787        default:
 788                ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 789                if (ret < 0)
 790                        return ret;
 791                break;
 792        }
 793
 794        /* map the entry point */
 795        if (params->hdr.e_entry) {
 796                seg = loadmap->segs;
 797                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 798                        if (params->hdr.e_entry >= seg->p_vaddr &&
 799                            params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 800                                params->entry_addr =
 801                                        (params->hdr.e_entry - seg->p_vaddr) +
 802                                        seg->addr;
 803                                break;
 804                        }
 805                }
 806        }
 807
 808        /* determine where the program header table has wound up if mapped */
 809        stop = params->hdr.e_phoff;
 810        stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 811        phdr = params->phdrs;
 812
 813        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 814                if (phdr->p_type != PT_LOAD)
 815                        continue;
 816
 817                if (phdr->p_offset > params->hdr.e_phoff ||
 818                    phdr->p_offset + phdr->p_filesz < stop)
 819                        continue;
 820
 821                seg = loadmap->segs;
 822                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 823                        if (phdr->p_vaddr >= seg->p_vaddr &&
 824                            phdr->p_vaddr + phdr->p_filesz <=
 825                            seg->p_vaddr + seg->p_memsz) {
 826                                params->ph_addr =
 827                                        (phdr->p_vaddr - seg->p_vaddr) +
 828                                        seg->addr +
 829                                        params->hdr.e_phoff - phdr->p_offset;
 830                                break;
 831                        }
 832                }
 833                break;
 834        }
 835
 836        /* determine where the dynamic section has wound up if there is one */
 837        phdr = params->phdrs;
 838        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 839                if (phdr->p_type != PT_DYNAMIC)
 840                        continue;
 841
 842                seg = loadmap->segs;
 843                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 844                        if (phdr->p_vaddr >= seg->p_vaddr &&
 845                            phdr->p_vaddr + phdr->p_memsz <=
 846                            seg->p_vaddr + seg->p_memsz) {
 847                                params->dynamic_addr =
 848                                        (phdr->p_vaddr - seg->p_vaddr) +
 849                                        seg->addr;
 850
 851                                /* check the dynamic section contains at least
 852                                 * one item, and that the last item is a NULL
 853                                 * entry */
 854                                if (phdr->p_memsz == 0 ||
 855                                    phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 856                                        goto dynamic_error;
 857
 858                                tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 859                                if (((Elf32_Dyn *)
 860                                     params->dynamic_addr)[tmp - 1].d_tag != 0)
 861                                        goto dynamic_error;
 862                                break;
 863                        }
 864                }
 865                break;
 866        }
 867
 868        /* now elide adjacent segments in the load map on MMU linux
 869         * - on uClinux the holes between may actually be filled with system
 870         *   stuff or stuff from other processes
 871         */
 872#ifdef CONFIG_MMU
 873        nloads = loadmap->nsegs;
 874        mseg = loadmap->segs;
 875        seg = mseg + 1;
 876        for (loop = 1; loop < nloads; loop++) {
 877                /* see if we have a candidate for merging */
 878                if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 879                        load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 880                        if (load_addr == (seg->addr & PAGE_MASK)) {
 881                                mseg->p_memsz +=
 882                                        load_addr -
 883                                        (mseg->addr + mseg->p_memsz);
 884                                mseg->p_memsz += seg->addr & ~PAGE_MASK;
 885                                mseg->p_memsz += seg->p_memsz;
 886                                loadmap->nsegs--;
 887                                continue;
 888                        }
 889                }
 890
 891                mseg++;
 892                if (mseg != seg)
 893                        *mseg = *seg;
 894        }
 895#endif
 896
 897        kdebug("Mapped Object [%s]:", what);
 898        kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 899        kdebug("- entry    : %lx", params->entry_addr);
 900        kdebug("- PHDR[]   : %lx", params->ph_addr);
 901        kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 902        seg = loadmap->segs;
 903        for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 904                kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 905                       loop,
 906                       seg->addr, seg->addr + seg->p_memsz - 1,
 907                       seg->p_vaddr, seg->p_memsz);
 908
 909        return 0;
 910
 911dynamic_error:
 912        printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 913               what, file->f_path.dentry->d_inode->i_ino);
 914        return -ELIBBAD;
 915}
 916
 917/*****************************************************************************/
 918/*
 919 * map a file with constant displacement under uClinux
 920 */
 921#ifndef CONFIG_MMU
 922static int elf_fdpic_map_file_constdisp_on_uclinux(
 923        struct elf_fdpic_params *params,
 924        struct file *file,
 925        struct mm_struct *mm)
 926{
 927        struct elf32_fdpic_loadseg *seg;
 928        struct elf32_phdr *phdr;
 929        unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 930        loff_t fpos;
 931        int loop, ret;
 932
 933        load_addr = params->load_addr;
 934        seg = params->loadmap->segs;
 935
 936        /* determine the bounds of the contiguous overall allocation we must
 937         * make */
 938        phdr = params->phdrs;
 939        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 940                if (params->phdrs[loop].p_type != PT_LOAD)
 941                        continue;
 942
 943                if (base > phdr->p_vaddr)
 944                        base = phdr->p_vaddr;
 945                if (top < phdr->p_vaddr + phdr->p_memsz)
 946                        top = phdr->p_vaddr + phdr->p_memsz;
 947        }
 948
 949        /* allocate one big anon block for everything */
 950        mflags = MAP_PRIVATE;
 951        if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 952                mflags |= MAP_EXECUTABLE;
 953
 954        maddr = vm_mmap(NULL, load_addr, top - base,
 955                        PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 956        if (IS_ERR_VALUE(maddr))
 957                return (int) maddr;
 958
 959        if (load_addr != 0)
 960                load_addr += PAGE_ALIGN(top - base);
 961
 962        /* and then load the file segments into it */
 963        phdr = params->phdrs;
 964        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 965                if (params->phdrs[loop].p_type != PT_LOAD)
 966                        continue;
 967
 968                fpos = phdr->p_offset;
 969
 970                seg->addr = maddr + (phdr->p_vaddr - base);
 971                seg->p_vaddr = phdr->p_vaddr;
 972                seg->p_memsz = phdr->p_memsz;
 973
 974                ret = file->f_op->read(file, (void *) seg->addr,
 975                                       phdr->p_filesz, &fpos);
 976                if (ret < 0)
 977                        return ret;
 978
 979                /* map the ELF header address if in this segment */
 980                if (phdr->p_offset == 0)
 981                        params->elfhdr_addr = seg->addr;
 982
 983                /* clear any space allocated but not loaded */
 984                if (phdr->p_filesz < phdr->p_memsz) {
 985                        if (clear_user((void *) (seg->addr + phdr->p_filesz),
 986                                       phdr->p_memsz - phdr->p_filesz))
 987                                return -EFAULT;
 988                }
 989
 990                if (mm) {
 991                        if (phdr->p_flags & PF_X) {
 992                                if (!mm->start_code) {
 993                                        mm->start_code = seg->addr;
 994                                        mm->end_code = seg->addr +
 995                                                phdr->p_memsz;
 996                                }
 997                        } else if (!mm->start_data) {
 998                                mm->start_data = seg->addr;
 999                                mm->end_data = seg->addr + phdr->p_memsz;
1000                        }
1001                }
1002
1003                seg++;
1004        }
1005
1006        return 0;
1007}
1008#endif
1009
1010/*****************************************************************************/
1011/*
1012 * map a binary by direct mmap() of the individual PT_LOAD segments
1013 */
1014static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1015                                             struct file *file,
1016                                             struct mm_struct *mm)
1017{
1018        struct elf32_fdpic_loadseg *seg;
1019        struct elf32_phdr *phdr;
1020        unsigned long load_addr, delta_vaddr;
1021        int loop, dvset;
1022
1023        load_addr = params->load_addr;
1024        delta_vaddr = 0;
1025        dvset = 0;
1026
1027        seg = params->loadmap->segs;
1028
1029        /* deal with each load segment separately */
1030        phdr = params->phdrs;
1031        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1032                unsigned long maddr, disp, excess, excess1;
1033                int prot = 0, flags;
1034
1035                if (phdr->p_type != PT_LOAD)
1036                        continue;
1037
1038                kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1039                       (unsigned long) phdr->p_vaddr,
1040                       (unsigned long) phdr->p_offset,
1041                       (unsigned long) phdr->p_filesz,
1042                       (unsigned long) phdr->p_memsz);
1043
1044                /* determine the mapping parameters */
1045                if (phdr->p_flags & PF_R) prot |= PROT_READ;
1046                if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1047                if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1048
1049                flags = MAP_PRIVATE | MAP_DENYWRITE;
1050                if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1051                        flags |= MAP_EXECUTABLE;
1052
1053                maddr = 0;
1054
1055                switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1056                case ELF_FDPIC_FLAG_INDEPENDENT:
1057                        /* PT_LOADs are independently locatable */
1058                        break;
1059
1060                case ELF_FDPIC_FLAG_HONOURVADDR:
1061                        /* the specified virtual address must be honoured */
1062                        maddr = phdr->p_vaddr;
1063                        flags |= MAP_FIXED;
1064                        break;
1065
1066                case ELF_FDPIC_FLAG_CONSTDISP:
1067                        /* constant displacement
1068                         * - can be mapped anywhere, but must be mapped as a
1069                         *   unit
1070                         */
1071                        if (!dvset) {
1072                                maddr = load_addr;
1073                                delta_vaddr = phdr->p_vaddr;
1074                                dvset = 1;
1075                        } else {
1076                                maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1077                                flags |= MAP_FIXED;
1078                        }
1079                        break;
1080
1081                case ELF_FDPIC_FLAG_CONTIGUOUS:
1082                        /* contiguity handled later */
1083                        break;
1084
1085                default:
1086                        BUG();
1087                }
1088
1089                maddr &= PAGE_MASK;
1090
1091                /* create the mapping */
1092                disp = phdr->p_vaddr & ~PAGE_MASK;
1093                maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1094                                phdr->p_offset - disp);
1095
1096                kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1097                       loop, phdr->p_memsz + disp, prot, flags,
1098                       phdr->p_offset - disp, maddr);
1099
1100                if (IS_ERR_VALUE(maddr))
1101                        return (int) maddr;
1102
1103                if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1104                    ELF_FDPIC_FLAG_CONTIGUOUS)
1105                        load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1106
1107                seg->addr = maddr + disp;
1108                seg->p_vaddr = phdr->p_vaddr;
1109                seg->p_memsz = phdr->p_memsz;
1110
1111                /* map the ELF header address if in this segment */
1112                if (phdr->p_offset == 0)
1113                        params->elfhdr_addr = seg->addr;
1114
1115                /* clear the bit between beginning of mapping and beginning of
1116                 * PT_LOAD */
1117                if (prot & PROT_WRITE && disp > 0) {
1118                        kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1119                        if (clear_user((void __user *) maddr, disp))
1120                                return -EFAULT;
1121                        maddr += disp;
1122                }
1123
1124                /* clear any space allocated but not loaded
1125                 * - on uClinux we can just clear the lot
1126                 * - on MMU linux we'll get a SIGBUS beyond the last page
1127                 *   extant in the file
1128                 */
1129                excess = phdr->p_memsz - phdr->p_filesz;
1130                excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1131
1132#ifdef CONFIG_MMU
1133                if (excess > excess1) {
1134                        unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1135                        unsigned long xmaddr;
1136
1137                        flags |= MAP_FIXED | MAP_ANONYMOUS;
1138                        xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1139                                         prot, flags, 0);
1140
1141                        kdebug("mmap[%d] <anon>"
1142                               " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1143                               loop, xaddr, excess - excess1, prot, flags,
1144                               xmaddr);
1145
1146                        if (xmaddr != xaddr)
1147                                return -ENOMEM;
1148                }
1149
1150                if (prot & PROT_WRITE && excess1 > 0) {
1151                        kdebug("clear[%d] ad=%lx sz=%lx",
1152                               loop, maddr + phdr->p_filesz, excess1);
1153                        if (clear_user((void __user *) maddr + phdr->p_filesz,
1154                                       excess1))
1155                                return -EFAULT;
1156                }
1157
1158#else
1159                if (excess > 0) {
1160                        kdebug("clear[%d] ad=%lx sz=%lx",
1161                               loop, maddr + phdr->p_filesz, excess);
1162                        if (clear_user((void *) maddr + phdr->p_filesz, excess))
1163                                return -EFAULT;
1164                }
1165#endif
1166
1167                if (mm) {
1168                        if (phdr->p_flags & PF_X) {
1169                                if (!mm->start_code) {
1170                                        mm->start_code = maddr;
1171                                        mm->end_code = maddr + phdr->p_memsz;
1172                                }
1173                        } else if (!mm->start_data) {
1174                                mm->start_data = maddr;
1175                                mm->end_data = maddr + phdr->p_memsz;
1176                        }
1177                }
1178
1179                seg++;
1180        }
1181
1182        return 0;
1183}
1184
1185/*****************************************************************************/
1186/*
1187 * ELF-FDPIC core dumper
1188 *
1189 * Modelled on fs/exec.c:aout_core_dump()
1190 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1191 *
1192 * Modelled on fs/binfmt_elf.c core dumper
1193 */
1194#ifdef CONFIG_ELF_CORE
1195
1196/*
1197 * Decide whether a segment is worth dumping; default is yes to be
1198 * sure (missing info is worse than too much; etc).
1199 * Personally I'd include everything, and use the coredump limit...
1200 *
1201 * I think we should skip something. But I am not sure how. H.J.
1202 */
1203static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1204{
1205        int dump_ok;
1206
1207        /* Do not dump I/O mapped devices or special mappings */
1208        if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1209                kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1210                return 0;
1211        }
1212
1213        /* If we may not read the contents, don't allow us to dump
1214         * them either. "dump_write()" can't handle it anyway.
1215         */
1216        if (!(vma->vm_flags & VM_READ)) {
1217                kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1218                return 0;
1219        }
1220
1221        /* By default, dump shared memory if mapped from an anonymous file. */
1222        if (vma->vm_flags & VM_SHARED) {
1223                if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1224                        dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1225                        kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1226                               vma->vm_flags, dump_ok ? "yes" : "no");
1227                        return dump_ok;
1228                }
1229
1230                dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1231                kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1232                       vma->vm_flags, dump_ok ? "yes" : "no");
1233                return dump_ok;
1234        }
1235
1236#ifdef CONFIG_MMU
1237        /* By default, if it hasn't been written to, don't write it out */
1238        if (!vma->anon_vma) {
1239                dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1240                kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1241                       vma->vm_flags, dump_ok ? "yes" : "no");
1242                return dump_ok;
1243        }
1244#endif
1245
1246        dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1247        kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1248               dump_ok ? "yes" : "no");
1249        return dump_ok;
1250}
1251
1252/* An ELF note in memory */
1253struct memelfnote
1254{
1255        const char *name;
1256        int type;
1257        unsigned int datasz;
1258        void *data;
1259};
1260
1261static int notesize(struct memelfnote *en)
1262{
1263        int sz;
1264
1265        sz = sizeof(struct elf_note);
1266        sz += roundup(strlen(en->name) + 1, 4);
1267        sz += roundup(en->datasz, 4);
1268
1269        return sz;
1270}
1271
1272/* #define DEBUG */
1273
1274#define DUMP_WRITE(addr, nr, foffset)   \
1275        do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1276
1277static int alignfile(struct file *file, loff_t *foffset)
1278{
1279        static const char buf[4] = { 0, };
1280        DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1281        return 1;
1282}
1283
1284static int writenote(struct memelfnote *men, struct file *file,
1285                        loff_t *foffset)
1286{
1287        struct elf_note en;
1288        en.n_namesz = strlen(men->name) + 1;
1289        en.n_descsz = men->datasz;
1290        en.n_type = men->type;
1291
1292        DUMP_WRITE(&en, sizeof(en), foffset);
1293        DUMP_WRITE(men->name, en.n_namesz, foffset);
1294        if (!alignfile(file, foffset))
1295                return 0;
1296        DUMP_WRITE(men->data, men->datasz, foffset);
1297        if (!alignfile(file, foffset))
1298                return 0;
1299
1300        return 1;
1301}
1302#undef DUMP_WRITE
1303
1304static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1305{
1306        memcpy(elf->e_ident, ELFMAG, SELFMAG);
1307        elf->e_ident[EI_CLASS] = ELF_CLASS;
1308        elf->e_ident[EI_DATA] = ELF_DATA;
1309        elf->e_ident[EI_VERSION] = EV_CURRENT;
1310        elf->e_ident[EI_OSABI] = ELF_OSABI;
1311        memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1312
1313        elf->e_type = ET_CORE;
1314        elf->e_machine = ELF_ARCH;
1315        elf->e_version = EV_CURRENT;
1316        elf->e_entry = 0;
1317        elf->e_phoff = sizeof(struct elfhdr);
1318        elf->e_shoff = 0;
1319        elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1320        elf->e_ehsize = sizeof(struct elfhdr);
1321        elf->e_phentsize = sizeof(struct elf_phdr);
1322        elf->e_phnum = segs;
1323        elf->e_shentsize = 0;
1324        elf->e_shnum = 0;
1325        elf->e_shstrndx = 0;
1326        return;
1327}
1328
1329static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1330{
1331        phdr->p_type = PT_NOTE;
1332        phdr->p_offset = offset;
1333        phdr->p_vaddr = 0;
1334        phdr->p_paddr = 0;
1335        phdr->p_filesz = sz;
1336        phdr->p_memsz = 0;
1337        phdr->p_flags = 0;
1338        phdr->p_align = 0;
1339        return;
1340}
1341
1342static inline void fill_note(struct memelfnote *note, const char *name, int type,
1343                unsigned int sz, void *data)
1344{
1345        note->name = name;
1346        note->type = type;
1347        note->datasz = sz;
1348        note->data = data;
1349        return;
1350}
1351
1352/*
1353 * fill up all the fields in prstatus from the given task struct, except
1354 * registers which need to be filled up separately.
1355 */
1356static void fill_prstatus(struct elf_prstatus *prstatus,
1357                          struct task_struct *p, long signr)
1358{
1359        prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1360        prstatus->pr_sigpend = p->pending.signal.sig[0];
1361        prstatus->pr_sighold = p->blocked.sig[0];
1362        rcu_read_lock();
1363        prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1364        rcu_read_unlock();
1365        prstatus->pr_pid = task_pid_vnr(p);
1366        prstatus->pr_pgrp = task_pgrp_vnr(p);
1367        prstatus->pr_sid = task_session_vnr(p);
1368        if (thread_group_leader(p)) {
1369                struct task_cputime cputime;
1370
1371                /*
1372                 * This is the record for the group leader.  It shows the
1373                 * group-wide total, not its individual thread total.
1374                 */
1375                thread_group_cputime(p, &cputime);
1376                cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1377                cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1378        } else {
1379                cputime_to_timeval(p->utime, &prstatus->pr_utime);
1380                cputime_to_timeval(p->stime, &prstatus->pr_stime);
1381        }
1382        cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1383        cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1384
1385        prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1386        prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1387}
1388
1389static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1390                       struct mm_struct *mm)
1391{
1392        const struct cred *cred;
1393        unsigned int i, len;
1394
1395        /* first copy the parameters from user space */
1396        memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1397
1398        len = mm->arg_end - mm->arg_start;
1399        if (len >= ELF_PRARGSZ)
1400                len = ELF_PRARGSZ - 1;
1401        if (copy_from_user(&psinfo->pr_psargs,
1402                           (const char __user *) mm->arg_start, len))
1403                return -EFAULT;
1404        for (i = 0; i < len; i++)
1405                if (psinfo->pr_psargs[i] == 0)
1406                        psinfo->pr_psargs[i] = ' ';
1407        psinfo->pr_psargs[len] = 0;
1408
1409        rcu_read_lock();
1410        psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1411        rcu_read_unlock();
1412        psinfo->pr_pid = task_pid_vnr(p);
1413        psinfo->pr_pgrp = task_pgrp_vnr(p);
1414        psinfo->pr_sid = task_session_vnr(p);
1415
1416        i = p->state ? ffz(~p->state) + 1 : 0;
1417        psinfo->pr_state = i;
1418        psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1419        psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1420        psinfo->pr_nice = task_nice(p);
1421        psinfo->pr_flag = p->flags;
1422        rcu_read_lock();
1423        cred = __task_cred(p);
1424        SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1425        SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1426        rcu_read_unlock();
1427        strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1428
1429        return 0;
1430}
1431
1432/* Here is the structure in which status of each thread is captured. */
1433struct elf_thread_status
1434{
1435        struct list_head list;
1436        struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1437        elf_fpregset_t fpu;             /* NT_PRFPREG */
1438        struct task_struct *thread;
1439#ifdef ELF_CORE_COPY_XFPREGS
1440        elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1441#endif
1442        struct memelfnote notes[3];
1443        int num_notes;
1444};
1445
1446/*
1447 * In order to add the specific thread information for the elf file format,
1448 * we need to keep a linked list of every thread's pr_status and then create
1449 * a single section for them in the final core file.
1450 */
1451static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1452{
1453        struct task_struct *p = t->thread;
1454        int sz = 0;
1455
1456        t->num_notes = 0;
1457
1458        fill_prstatus(&t->prstatus, p, signr);
1459        elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1460
1461        fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1462                  &t->prstatus);
1463        t->num_notes++;
1464        sz += notesize(&t->notes[0]);
1465
1466        t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1467        if (t->prstatus.pr_fpvalid) {
1468                fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1469                          &t->fpu);
1470                t->num_notes++;
1471                sz += notesize(&t->notes[1]);
1472        }
1473
1474#ifdef ELF_CORE_COPY_XFPREGS
1475        if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1476                fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1477                          sizeof(t->xfpu), &t->xfpu);
1478                t->num_notes++;
1479                sz += notesize(&t->notes[2]);
1480        }
1481#endif
1482        return sz;
1483}
1484
1485static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1486                             elf_addr_t e_shoff, int segs)
1487{
1488        elf->e_shoff = e_shoff;
1489        elf->e_shentsize = sizeof(*shdr4extnum);
1490        elf->e_shnum = 1;
1491        elf->e_shstrndx = SHN_UNDEF;
1492
1493        memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1494
1495        shdr4extnum->sh_type = SHT_NULL;
1496        shdr4extnum->sh_size = elf->e_shnum;
1497        shdr4extnum->sh_link = elf->e_shstrndx;
1498        shdr4extnum->sh_info = segs;
1499}
1500
1501/*
1502 * dump the segments for an MMU process
1503 */
1504#ifdef CONFIG_MMU
1505static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1506                           unsigned long *limit, unsigned long mm_flags)
1507{
1508        struct vm_area_struct *vma;
1509        int err = 0;
1510
1511        for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1512                unsigned long addr;
1513
1514                if (!maydump(vma, mm_flags))
1515                        continue;
1516
1517                for (addr = vma->vm_start; addr < vma->vm_end;
1518                                                        addr += PAGE_SIZE) {
1519                        struct page *page = get_dump_page(addr);
1520                        if (page) {
1521                                void *kaddr = kmap(page);
1522                                *size += PAGE_SIZE;
1523                                if (*size > *limit)
1524                                        err = -EFBIG;
1525                                else if (!dump_write(file, kaddr, PAGE_SIZE))
1526                                        err = -EIO;
1527                                kunmap(page);
1528                                page_cache_release(page);
1529                        } else if (!dump_seek(file, PAGE_SIZE))
1530                                err = -EFBIG;
1531                        if (err)
1532                                goto out;
1533                }
1534        }
1535out:
1536        return err;
1537}
1538#endif
1539
1540/*
1541 * dump the segments for a NOMMU process
1542 */
1543#ifndef CONFIG_MMU
1544static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1545                           unsigned long *limit, unsigned long mm_flags)
1546{
1547        struct vm_area_struct *vma;
1548
1549        for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1550                if (!maydump(vma, mm_flags))
1551                        continue;
1552
1553                if ((*size += PAGE_SIZE) > *limit)
1554                        return -EFBIG;
1555
1556                if (!dump_write(file, (void *) vma->vm_start,
1557                                vma->vm_end - vma->vm_start))
1558                        return -EIO;
1559        }
1560
1561        return 0;
1562}
1563#endif
1564
1565static size_t elf_core_vma_data_size(unsigned long mm_flags)
1566{
1567        struct vm_area_struct *vma;
1568        size_t size = 0;
1569
1570        for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1571                if (maydump(vma, mm_flags))
1572                        size += vma->vm_end - vma->vm_start;
1573        return size;
1574}
1575
1576/*
1577 * Actual dumper
1578 *
1579 * This is a two-pass process; first we find the offsets of the bits,
1580 * and then they are actually written out.  If we run out of core limit
1581 * we just truncate.
1582 */
1583static int elf_fdpic_core_dump(struct coredump_params *cprm)
1584{
1585#define NUM_NOTES       6
1586        int has_dumped = 0;
1587        mm_segment_t fs;
1588        int segs;
1589        size_t size = 0;
1590        int i;
1591        struct vm_area_struct *vma;
1592        struct elfhdr *elf = NULL;
1593        loff_t offset = 0, dataoff, foffset;
1594        int numnote;
1595        struct memelfnote *notes = NULL;
1596        struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1597        struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1598        LIST_HEAD(thread_list);
1599        struct list_head *t;
1600        elf_fpregset_t *fpu = NULL;
1601#ifdef ELF_CORE_COPY_XFPREGS
1602        elf_fpxregset_t *xfpu = NULL;
1603#endif
1604        int thread_status_size = 0;
1605        elf_addr_t *auxv;
1606        struct elf_phdr *phdr4note = NULL;
1607        struct elf_shdr *shdr4extnum = NULL;
1608        Elf_Half e_phnum;
1609        elf_addr_t e_shoff;
1610
1611        /*
1612         * We no longer stop all VM operations.
1613         *
1614         * This is because those proceses that could possibly change map_count
1615         * or the mmap / vma pages are now blocked in do_exit on current
1616         * finishing this core dump.
1617         *
1618         * Only ptrace can touch these memory addresses, but it doesn't change
1619         * the map_count or the pages allocated. So no possibility of crashing
1620         * exists while dumping the mm->vm_next areas to the core file.
1621         */
1622
1623        /* alloc memory for large data structures: too large to be on stack */
1624        elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1625        if (!elf)
1626                goto cleanup;
1627        prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1628        if (!prstatus)
1629                goto cleanup;
1630        psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1631        if (!psinfo)
1632                goto cleanup;
1633        notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1634        if (!notes)
1635                goto cleanup;
1636        fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1637        if (!fpu)
1638                goto cleanup;
1639#ifdef ELF_CORE_COPY_XFPREGS
1640        xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1641        if (!xfpu)
1642                goto cleanup;
1643#endif
1644
1645        if (cprm->signr) {
1646                struct core_thread *ct;
1647                struct elf_thread_status *tmp;
1648
1649                for (ct = current->mm->core_state->dumper.next;
1650                                                ct; ct = ct->next) {
1651                        tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1652                        if (!tmp)
1653                                goto cleanup;
1654
1655                        tmp->thread = ct->task;
1656                        list_add(&tmp->list, &thread_list);
1657                }
1658
1659                list_for_each(t, &thread_list) {
1660                        struct elf_thread_status *tmp;
1661                        int sz;
1662
1663                        tmp = list_entry(t, struct elf_thread_status, list);
1664                        sz = elf_dump_thread_status(cprm->signr, tmp);
1665                        thread_status_size += sz;
1666                }
1667        }
1668
1669        /* now collect the dump for the current */
1670        fill_prstatus(prstatus, current, cprm->signr);
1671        elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1672
1673        segs = current->mm->map_count;
1674        segs += elf_core_extra_phdrs();
1675
1676        /* for notes section */
1677        segs++;
1678
1679        /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1680         * this, kernel supports extended numbering. Have a look at
1681         * include/linux/elf.h for further information. */
1682        e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1683
1684        /* Set up header */
1685        fill_elf_fdpic_header(elf, e_phnum);
1686
1687        has_dumped = 1;
1688        current->flags |= PF_DUMPCORE;
1689
1690        /*
1691         * Set up the notes in similar form to SVR4 core dumps made
1692         * with info from their /proc.
1693         */
1694
1695        fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1696        fill_psinfo(psinfo, current->group_leader, current->mm);
1697        fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1698
1699        numnote = 2;
1700
1701        auxv = (elf_addr_t *) current->mm->saved_auxv;
1702
1703        i = 0;
1704        do
1705                i += 2;
1706        while (auxv[i - 2] != AT_NULL);
1707        fill_note(&notes[numnote++], "CORE", NT_AUXV,
1708                  i * sizeof(elf_addr_t), auxv);
1709
1710        /* Try to dump the FPU. */
1711        if ((prstatus->pr_fpvalid =
1712             elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1713                fill_note(notes + numnote++,
1714                          "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1715#ifdef ELF_CORE_COPY_XFPREGS
1716        if (elf_core_copy_task_xfpregs(current, xfpu))
1717                fill_note(notes + numnote++,
1718                          "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1719#endif
1720
1721        fs = get_fs();
1722        set_fs(KERNEL_DS);
1723
1724        offset += sizeof(*elf);                         /* Elf header */
1725        offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1726        foffset = offset;
1727
1728        /* Write notes phdr entry */
1729        {
1730                int sz = 0;
1731
1732                for (i = 0; i < numnote; i++)
1733                        sz += notesize(notes + i);
1734
1735                sz += thread_status_size;
1736
1737                phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1738                if (!phdr4note)
1739                        goto end_coredump;
1740
1741                fill_elf_note_phdr(phdr4note, sz, offset);
1742                offset += sz;
1743        }
1744
1745        /* Page-align dumped data */
1746        dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1747
1748        offset += elf_core_vma_data_size(cprm->mm_flags);
1749        offset += elf_core_extra_data_size();
1750        e_shoff = offset;
1751
1752        if (e_phnum == PN_XNUM) {
1753                shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1754                if (!shdr4extnum)
1755                        goto end_coredump;
1756                fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1757        }
1758
1759        offset = dataoff;
1760
1761        size += sizeof(*elf);
1762        if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1763                goto end_coredump;
1764
1765        size += sizeof(*phdr4note);
1766        if (size > cprm->limit
1767            || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1768                goto end_coredump;
1769
1770        /* write program headers for segments dump */
1771        for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1772                struct elf_phdr phdr;
1773                size_t sz;
1774
1775                sz = vma->vm_end - vma->vm_start;
1776
1777                phdr.p_type = PT_LOAD;
1778                phdr.p_offset = offset;
1779                phdr.p_vaddr = vma->vm_start;
1780                phdr.p_paddr = 0;
1781                phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1782                phdr.p_memsz = sz;
1783                offset += phdr.p_filesz;
1784                phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1785                if (vma->vm_flags & VM_WRITE)
1786                        phdr.p_flags |= PF_W;
1787                if (vma->vm_flags & VM_EXEC)
1788                        phdr.p_flags |= PF_X;
1789                phdr.p_align = ELF_EXEC_PAGESIZE;
1790
1791                size += sizeof(phdr);
1792                if (size > cprm->limit
1793                    || !dump_write(cprm->file, &phdr, sizeof(phdr)))
1794                        goto end_coredump;
1795        }
1796
1797        if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
1798                goto end_coredump;
1799
1800        /* write out the notes section */
1801        for (i = 0; i < numnote; i++)
1802                if (!writenote(notes + i, cprm->file, &foffset))
1803                        goto end_coredump;
1804
1805        /* write out the thread status notes section */
1806        list_for_each(t, &thread_list) {
1807                struct elf_thread_status *tmp =
1808                                list_entry(t, struct elf_thread_status, list);
1809
1810                for (i = 0; i < tmp->num_notes; i++)
1811                        if (!writenote(&tmp->notes[i], cprm->file, &foffset))
1812                                goto end_coredump;
1813        }
1814
1815        if (!dump_seek(cprm->file, dataoff - foffset))
1816                goto end_coredump;
1817
1818        if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit,
1819                                    cprm->mm_flags) < 0)
1820                goto end_coredump;
1821
1822        if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
1823                goto end_coredump;
1824
1825        if (e_phnum == PN_XNUM) {
1826                size += sizeof(*shdr4extnum);
1827                if (size > cprm->limit
1828                    || !dump_write(cprm->file, shdr4extnum,
1829                                   sizeof(*shdr4extnum)))
1830                        goto end_coredump;
1831        }
1832
1833        if (cprm->file->f_pos != offset) {
1834                /* Sanity check */
1835                printk(KERN_WARNING
1836                       "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1837                       cprm->file->f_pos, offset);
1838        }
1839
1840end_coredump:
1841        set_fs(fs);
1842
1843cleanup:
1844        while (!list_empty(&thread_list)) {
1845                struct list_head *tmp = thread_list.next;
1846                list_del(tmp);
1847                kfree(list_entry(tmp, struct elf_thread_status, list));
1848        }
1849        kfree(phdr4note);
1850        kfree(elf);
1851        kfree(prstatus);
1852        kfree(psinfo);
1853        kfree(notes);
1854        kfree(fpu);
1855        kfree(shdr4extnum);
1856#ifdef ELF_CORE_COPY_XFPREGS
1857        kfree(xfpu);
1858#endif
1859        return has_dumped;
1860#undef NUM_NOTES
1861}
1862
1863#endif          /* CONFIG_ELF_CORE */
1864
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