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
  43typedef char *elf_caddr_t;
  44
  45#if 0
  46#define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  47#else
  48#define kdebug(fmt, ...) do {} while(0)
  49#endif
  50
  51#if 0
  52#define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
  53#else
  54#define kdcore(fmt, ...) do {} while(0)
  55#endif
  56
  57MODULE_LICENSE("GPL");
  58
  59static int load_elf_fdpic_binary(struct linux_binprm *);
  60static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  61static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  62                              struct mm_struct *, const char *);
  63
  64static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
  65                                   struct elf_fdpic_params *,
  66                                   struct elf_fdpic_params *);
  67
  68#ifndef CONFIG_MMU
  69static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
  70                                            unsigned long *);
  71static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  72                                                   struct file *,
  73                                                   struct mm_struct *);
  74#endif
  75
  76static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  77                                             struct file *, struct mm_struct *);
  78
  79#ifdef CONFIG_ELF_CORE
  80static int elf_fdpic_core_dump(struct coredump_params *cprm);
  81#endif
  82
  83static struct linux_binfmt elf_fdpic_format = {
  84        .module         = THIS_MODULE,
  85        .load_binary    = load_elf_fdpic_binary,
  86#ifdef CONFIG_ELF_CORE
  87        .core_dump      = elf_fdpic_core_dump,
  88#endif
  89        .min_coredump   = ELF_EXEC_PAGESIZE,
  90};
  91
  92static int __init init_elf_fdpic_binfmt(void)
  93{
  94        register_binfmt(&elf_fdpic_format);
  95        return 0;
  96}
  97
  98static void __exit exit_elf_fdpic_binfmt(void)
  99{
 100        unregister_binfmt(&elf_fdpic_format);
 101}
 102
 103core_initcall(init_elf_fdpic_binfmt);
 104module_exit(exit_elf_fdpic_binfmt);
 105
 106static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
 107{
 108        if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 109                return 0;
 110        if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 111                return 0;
 112        if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
 113                return 0;
 114        if (!file->f_op || !file->f_op->mmap)
 115                return 0;
 116        return 1;
 117}
 118
 119/*****************************************************************************/
 120/*
 121 * read the program headers table into memory
 122 */
 123static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 124                                 struct file *file)
 125{
 126        struct elf32_phdr *phdr;
 127        unsigned long size;
 128        int retval, loop;
 129
 130        if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 131                return -ENOMEM;
 132        if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 133                return -ENOMEM;
 134
 135        size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 136        params->phdrs = kmalloc(size, GFP_KERNEL);
 137        if (!params->phdrs)
 138                return -ENOMEM;
 139
 140        retval = kernel_read(file, params->hdr.e_phoff,
 141                             (char *) params->phdrs, size);
 142        if (unlikely(retval != size))
 143                return retval < 0 ? retval : -ENOEXEC;
 144
 145        /* determine stack size for this binary */
 146        phdr = params->phdrs;
 147        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 148                if (phdr->p_type != PT_GNU_STACK)
 149                        continue;
 150
 151                if (phdr->p_flags & PF_X)
 152                        params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 153                else
 154                        params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 155
 156                params->stack_size = phdr->p_memsz;
 157                break;
 158        }
 159
 160        return 0;
 161}
 162
 163/*****************************************************************************/
 164/*
 165 * load an fdpic binary into various bits of memory
 166 */
 167static int load_elf_fdpic_binary(struct linux_binprm *bprm)
 168{
 169        struct elf_fdpic_params exec_params, interp_params;
 170        struct pt_regs *regs = current_pt_regs();
 171        struct elf_phdr *phdr;
 172        unsigned long stack_size, entryaddr;
 173#ifdef ELF_FDPIC_PLAT_INIT
 174        unsigned long dynaddr;
 175#endif
 176#ifndef CONFIG_MMU
 177        unsigned long stack_prot;
 178#endif
 179        struct file *interpreter = NULL; /* to shut gcc up */
 180        char *interpreter_name = NULL;
 181        int executable_stack;
 182        int retval, i;
 183
 184        kdebug("____ LOAD %d ____", current->pid);
 185
 186        memset(&exec_params, 0, sizeof(exec_params));
 187        memset(&interp_params, 0, sizeof(interp_params));
 188
 189        exec_params.hdr = *(struct elfhdr *) bprm->buf;
 190        exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 191
 192        /* check that this is a binary we know how to deal with */
 193        retval = -ENOEXEC;
 194        if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
 195                goto error;
 196
 197        /* read the program header table */
 198        retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 199        if (retval < 0)
 200                goto error;
 201
 202        /* scan for a program header that specifies an interpreter */
 203        phdr = exec_params.phdrs;
 204
 205        for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 206                switch (phdr->p_type) {
 207                case PT_INTERP:
 208                        retval = -ENOMEM;
 209                        if (phdr->p_filesz > PATH_MAX)
 210                                goto error;
 211                        retval = -ENOENT;
 212                        if (phdr->p_filesz < 2)
 213                                goto error;
 214
 215                        /* read the name of the interpreter into memory */
 216                        interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 217                        if (!interpreter_name)
 218                                goto error;
 219
 220                        retval = kernel_read(bprm->file,
 221                                             phdr->p_offset,
 222                                             interpreter_name,
 223                                             phdr->p_filesz);
 224                        if (unlikely(retval != phdr->p_filesz)) {
 225                                if (retval >= 0)
 226                                        retval = -ENOEXEC;
 227                                goto error;
 228                        }
 229
 230                        retval = -ENOENT;
 231                        if (interpreter_name[phdr->p_filesz - 1] != '\0')
 232                                goto error;
 233
 234                        kdebug("Using ELF interpreter %s", interpreter_name);
 235
 236                        /* replace the program with the interpreter */
 237                        interpreter = open_exec(interpreter_name);
 238                        retval = PTR_ERR(interpreter);
 239                        if (IS_ERR(interpreter)) {
 240                                interpreter = NULL;
 241                                goto error;
 242                        }
 243
 244                        /*
 245                         * If the binary is not readable then enforce
 246                         * mm->dumpable = 0 regardless of the interpreter's
 247                         * permissions.
 248                         */
 249                        would_dump(bprm, interpreter);
 250
 251                        retval = kernel_read(interpreter, 0, bprm->buf,
 252                                             BINPRM_BUF_SIZE);
 253                        if (unlikely(retval != BINPRM_BUF_SIZE)) {
 254                                if (retval >= 0)
 255                                        retval = -ENOEXEC;
 256                                goto error;
 257                        }
 258
 259                        interp_params.hdr = *((struct elfhdr *) bprm->buf);
 260                        break;
 261
 262                case PT_LOAD:
 263#ifdef CONFIG_MMU
 264                        if (exec_params.load_addr == 0)
 265                                exec_params.load_addr = phdr->p_vaddr;
 266#endif
 267                        break;
 268                }
 269
 270        }
 271
 272        if (elf_check_const_displacement(&exec_params.hdr))
 273                exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 274
 275        /* perform insanity checks on the interpreter */
 276        if (interpreter_name) {
 277                retval = -ELIBBAD;
 278                if (!is_elf_fdpic(&interp_params.hdr, interpreter))
 279                        goto error;
 280
 281                interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 282
 283                /* read the interpreter's program header table */
 284                retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 285                if (retval < 0)
 286                        goto error;
 287        }
 288
 289        stack_size = exec_params.stack_size;
 290        if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 291                executable_stack = EXSTACK_ENABLE_X;
 292        else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 293                executable_stack = EXSTACK_DISABLE_X;
 294        else
 295                executable_stack = EXSTACK_DEFAULT;
 296
 297        if (stack_size == 0) {
 298                stack_size = interp_params.stack_size;
 299                if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 300                        executable_stack = EXSTACK_ENABLE_X;
 301                else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 302                        executable_stack = EXSTACK_DISABLE_X;
 303                else
 304                        executable_stack = EXSTACK_DEFAULT;
 305        }
 306
 307        retval = -ENOEXEC;
 308        if (stack_size == 0)
 309                goto error;
 310
 311        if (elf_check_const_displacement(&interp_params.hdr))
 312                interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 313
 314        /* flush all traces of the currently running executable */
 315        retval = flush_old_exec(bprm);
 316        if (retval)
 317                goto error;
 318
 319        /* there's now no turning back... the old userspace image is dead,
 320         * defunct, deceased, etc. after this point we have to exit via
 321         * error_kill */
 322        set_personality(PER_LINUX_FDPIC);
 323        if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
 324                current->personality |= READ_IMPLIES_EXEC;
 325
 326        setup_new_exec(bprm);
 327
 328        set_binfmt(&elf_fdpic_format);
 329
 330        current->mm->start_code = 0;
 331        current->mm->end_code = 0;
 332        current->mm->start_stack = 0;
 333        current->mm->start_data = 0;
 334        current->mm->end_data = 0;
 335        current->mm->context.exec_fdpic_loadmap = 0;
 336        current->mm->context.interp_fdpic_loadmap = 0;
 337
 338#ifdef CONFIG_MMU
 339        elf_fdpic_arch_lay_out_mm(&exec_params,
 340                                  &interp_params,
 341                                  &current->mm->start_stack,
 342                                  &current->mm->start_brk);
 343
 344        retval = setup_arg_pages(bprm, current->mm->start_stack,
 345                                 executable_stack);
 346        if (retval < 0) {
 347                send_sig(SIGKILL, current, 0);
 348                goto error_kill;
 349        }
 350#endif
 351
 352        /* load the executable and interpreter into memory */
 353        retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 354                                    "executable");
 355        if (retval < 0)
 356                goto error_kill;
 357
 358        if (interpreter_name) {
 359                retval = elf_fdpic_map_file(&interp_params, interpreter,
 360                                            current->mm, "interpreter");
 361                if (retval < 0) {
 362                        printk(KERN_ERR "Unable to load interpreter\n");
 363                        goto error_kill;
 364                }
 365
 366                allow_write_access(interpreter);
 367                fput(interpreter);
 368                interpreter = NULL;
 369        }
 370
 371#ifdef CONFIG_MMU
 372        if (!current->mm->start_brk)
 373                current->mm->start_brk = current->mm->end_data;
 374
 375        current->mm->brk = current->mm->start_brk =
 376                PAGE_ALIGN(current->mm->start_brk);
 377
 378#else
 379        /* create a stack and brk area big enough for everyone
 380         * - the brk heap starts at the bottom and works up
 381         * - the stack starts at the top and works down
 382         */
 383        stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 384        if (stack_size < PAGE_SIZE * 2)
 385                stack_size = PAGE_SIZE * 2;
 386
 387        stack_prot = PROT_READ | PROT_WRITE;
 388        if (executable_stack == EXSTACK_ENABLE_X ||
 389            (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 390                stack_prot |= PROT_EXEC;
 391
 392        current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 393                                         MAP_PRIVATE | MAP_ANONYMOUS |
 394                                         MAP_UNINITIALIZED | MAP_GROWSDOWN,
 395                                         0);
 396
 397        if (IS_ERR_VALUE(current->mm->start_brk)) {
 398                retval = current->mm->start_brk;
 399                current->mm->start_brk = 0;
 400                goto error_kill;
 401        }
 402
 403        current->mm->brk = current->mm->start_brk;
 404        current->mm->context.end_brk = current->mm->start_brk;
 405        current->mm->context.end_brk +=
 406                (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
 407        current->mm->start_stack = current->mm->start_brk + stack_size;
 408#endif
 409
 410        install_exec_creds(bprm);
 411        if (create_elf_fdpic_tables(bprm, current->mm,
 412                                    &exec_params, &interp_params) < 0)
 413                goto error_kill;
 414
 415        kdebug("- start_code  %lx", current->mm->start_code);
 416        kdebug("- end_code    %lx", current->mm->end_code);
 417        kdebug("- start_data  %lx", current->mm->start_data);
 418        kdebug("- end_data    %lx", current->mm->end_data);
 419        kdebug("- start_brk   %lx", current->mm->start_brk);
 420        kdebug("- brk         %lx", current->mm->brk);
 421        kdebug("- start_stack %lx", current->mm->start_stack);
 422
 423#ifdef ELF_FDPIC_PLAT_INIT
 424        /*
 425         * The ABI may specify that certain registers be set up in special
 426         * ways (on i386 %edx is the address of a DT_FINI function, for
 427         * example.  This macro performs whatever initialization to
 428         * the regs structure is required.
 429         */
 430        dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 431        ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 432                            dynaddr);
 433#endif
 434
 435        /* everything is now ready... get the userspace context ready to roll */
 436        entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 437        start_thread(regs, entryaddr, current->mm->start_stack);
 438
 439        retval = 0;
 440
 441error:
 442        if (interpreter) {
 443                allow_write_access(interpreter);
 444                fput(interpreter);
 445        }
 446        kfree(interpreter_name);
 447        kfree(exec_params.phdrs);
 448        kfree(exec_params.loadmap);
 449        kfree(interp_params.phdrs);
 450        kfree(interp_params.loadmap);
 451        return retval;
 452
 453        /* unrecoverable error - kill the process */
 454error_kill:
 455        send_sig(SIGSEGV, current, 0);
 456        goto error;
 457
 458}
 459
 460/*****************************************************************************/
 461
 462#ifndef ELF_BASE_PLATFORM
 463/*
 464 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 465 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 466 * will be copied to the user stack in the same manner as AT_PLATFORM.
 467 */
 468#define ELF_BASE_PLATFORM NULL
 469#endif
 470
 471/*
 472 * present useful information to the program by shovelling it onto the new
 473 * process's stack
 474 */
 475static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 476                                   struct mm_struct *mm,
 477                                   struct elf_fdpic_params *exec_params,
 478                                   struct elf_fdpic_params *interp_params)
 479{
 480        const struct cred *cred = current_cred();
 481        unsigned long sp, csp, nitems;
 482        elf_caddr_t __user *argv, *envp;
 483        size_t platform_len = 0, len;
 484        char *k_platform, *k_base_platform;
 485        char __user *u_platform, *u_base_platform, *p;
 486        int loop;
 487        int nr; /* reset for each csp adjustment */
 488
 489#ifdef CONFIG_MMU
 490        /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 491         * by the processes running on the same package. One thing we can do is
 492         * to shuffle the initial stack for them, so we give the architecture
 493         * an opportunity to do so here.
 494         */
 495        sp = arch_align_stack(bprm->p);
 496#else
 497        sp = mm->start_stack;
 498
 499        /* stack the program arguments and environment */
 500        if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
 501                return -EFAULT;
 502#endif
 503
 504        /*
 505         * If this architecture has a platform capability string, copy it
 506         * to userspace.  In some cases (Sparc), this info is impossible
 507         * for userspace to get any other way, in others (i386) it is
 508         * merely difficult.
 509         */
 510        k_platform = ELF_PLATFORM;
 511        u_platform = NULL;
 512
 513        if (k_platform) {
 514                platform_len = strlen(k_platform) + 1;
 515                sp -= platform_len;
 516                u_platform = (char __user *) sp;
 517                if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
 518                        return -EFAULT;
 519        }
 520
 521        /*
 522         * If this architecture has a "base" platform capability
 523         * string, copy it to userspace.
 524         */
 525        k_base_platform = ELF_BASE_PLATFORM;
 526        u_base_platform = NULL;
 527
 528        if (k_base_platform) {
 529                platform_len = strlen(k_base_platform) + 1;
 530                sp -= platform_len;
 531                u_base_platform = (char __user *) sp;
 532                if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 533                        return -EFAULT;
 534        }
 535
 536        sp &= ~7UL;
 537
 538        /* stack the load map(s) */
 539        len = sizeof(struct elf32_fdpic_loadmap);
 540        len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 541        sp = (sp - len) & ~7UL;
 542        exec_params->map_addr = sp;
 543
 544        if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 545                return -EFAULT;
 546
 547        current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 548
 549        if (interp_params->loadmap) {
 550                len = sizeof(struct elf32_fdpic_loadmap);
 551                len += sizeof(struct elf32_fdpic_loadseg) *
 552                        interp_params->loadmap->nsegs;
 553                sp = (sp - len) & ~7UL;
 554                interp_params->map_addr = sp;
 555
 556                if (copy_to_user((void __user *) sp, interp_params->loadmap,
 557                                 len) != 0)
 558                        return -EFAULT;
 559
 560                current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 561        }
 562
 563        /* force 16 byte _final_ alignment here for generality */
 564#define DLINFO_ITEMS 15
 565
 566        nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 567                (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 568
 569        if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
 570                nitems++;
 571
 572        csp = sp;
 573        sp -= nitems * 2 * sizeof(unsigned long);
 574        sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 575        sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 576        sp -= 1 * sizeof(unsigned long);                /* argc */
 577
 578        csp -= sp & 15UL;
 579        sp -= sp & 15UL;
 580
 581        /* put the ELF interpreter info on the stack */
 582#define NEW_AUX_ENT(id, val)                                            \
 583        do {                                                            \
 584                struct { unsigned long _id, _val; } __user *ent;        \
 585                                                                        \
 586                ent = (void __user *) csp;                              \
 587                __put_user((id), &ent[nr]._id);                         \
 588                __put_user((val), &ent[nr]._val);                       \
 589                nr++;                                                   \
 590        } while (0)
 591
 592        nr = 0;
 593        csp -= 2 * sizeof(unsigned long);
 594        NEW_AUX_ENT(AT_NULL, 0);
 595        if (k_platform) {
 596                nr = 0;
 597                csp -= 2 * sizeof(unsigned long);
 598                NEW_AUX_ENT(AT_PLATFORM,
 599                            (elf_addr_t) (unsigned long) u_platform);
 600        }
 601
 602        if (k_base_platform) {
 603                nr = 0;
 604                csp -= 2 * sizeof(unsigned long);
 605                NEW_AUX_ENT(AT_BASE_PLATFORM,
 606                            (elf_addr_t) (unsigned long) u_base_platform);
 607        }
 608
 609        if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
 610                nr = 0;
 611                csp -= 2 * sizeof(unsigned long);
 612                NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
 613        }
 614
 615        nr = 0;
 616        csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 617        NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 618#ifdef ELF_HWCAP2
 619        NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 620#endif
 621        NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 622        NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 623        NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 624        NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 625        NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 626        NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 627        NEW_AUX_ENT(AT_FLAGS,   0);
 628        NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 629        NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 630        NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 631        NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 632        NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 633        NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
 634        NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 635
 636#ifdef ARCH_DLINFO
 637        nr = 0;
 638        csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 639
 640        /* ARCH_DLINFO must come last so platform specific code can enforce
 641         * special alignment requirements on the AUXV if necessary (eg. PPC).
 642         */
 643        ARCH_DLINFO;
 644#endif
 645#undef NEW_AUX_ENT
 646
 647        /* allocate room for argv[] and envv[] */
 648        csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 649        envp = (elf_caddr_t __user *) csp;
 650        csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 651        argv = (elf_caddr_t __user *) csp;
 652
 653        /* stack argc */
 654        csp -= sizeof(unsigned long);
 655        __put_user(bprm->argc, (unsigned long __user *) csp);
 656
 657        BUG_ON(csp != sp);
 658
 659        /* fill in the argv[] array */
 660#ifdef CONFIG_MMU
 661        current->mm->arg_start = bprm->p;
 662#else
 663        current->mm->arg_start = current->mm->start_stack -
 664                (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 665#endif
 666
 667        p = (char __user *) current->mm->arg_start;
 668        for (loop = bprm->argc; loop > 0; loop--) {
 669                __put_user((elf_caddr_t) p, argv++);
 670                len = strnlen_user(p, MAX_ARG_STRLEN);
 671                if (!len || len > MAX_ARG_STRLEN)
 672                        return -EINVAL;
 673                p += len;
 674        }
 675        __put_user(NULL, argv);
 676        current->mm->arg_end = (unsigned long) p;
 677
 678        /* fill in the envv[] array */
 679        current->mm->env_start = (unsigned long) p;
 680        for (loop = bprm->envc; loop > 0; loop--) {
 681                __put_user((elf_caddr_t)(unsigned long) p, envp++);
 682                len = strnlen_user(p, MAX_ARG_STRLEN);
 683                if (!len || len > MAX_ARG_STRLEN)
 684                        return -EINVAL;
 685                p += len;
 686        }
 687        __put_user(NULL, envp);
 688        current->mm->env_end = (unsigned long) p;
 689
 690        mm->start_stack = (unsigned long) sp;
 691        return 0;
 692}
 693
 694/*****************************************************************************/
 695/*
 696 * transfer the program arguments and environment from the holding pages onto
 697 * the stack
 698 */
 699#ifndef CONFIG_MMU
 700static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
 701                                            unsigned long *_sp)
 702{
 703        unsigned long index, stop, sp;
 704        char *src;
 705        int ret = 0;
 706
 707        stop = bprm->p >> PAGE_SHIFT;
 708        sp = *_sp;
 709
 710        for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
 711                src = kmap(bprm->page[index]);
 712                sp -= PAGE_SIZE;
 713                if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
 714                        ret = -EFAULT;
 715                kunmap(bprm->page[index]);
 716                if (ret < 0)
 717                        goto out;
 718        }
 719
 720        *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
 721
 722out:
 723        return ret;
 724}
 725#endif
 726
 727/*****************************************************************************/
 728/*
 729 * load the appropriate binary image (executable or interpreter) into memory
 730 * - we assume no MMU is available
 731 * - if no other PIC bits are set in params->hdr->e_flags
 732 *   - we assume that the LOADable segments in the binary are independently relocatable
 733 *   - we assume R/O executable segments are shareable
 734 * - else
 735 *   - we assume the loadable parts of the image to require fixed displacement
 736 *   - the image is not shareable
 737 */
 738static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 739                              struct file *file,
 740                              struct mm_struct *mm,
 741                              const char *what)
 742{
 743        struct elf32_fdpic_loadmap *loadmap;
 744#ifdef CONFIG_MMU
 745        struct elf32_fdpic_loadseg *mseg;
 746#endif
 747        struct elf32_fdpic_loadseg *seg;
 748        struct elf32_phdr *phdr;
 749        unsigned long load_addr, stop;
 750        unsigned nloads, tmp;
 751        size_t size;
 752        int loop, ret;
 753
 754        /* allocate a load map table */
 755        nloads = 0;
 756        for (loop = 0; loop < params->hdr.e_phnum; loop++)
 757                if (params->phdrs[loop].p_type == PT_LOAD)
 758                        nloads++;
 759
 760        if (nloads == 0)
 761                return -ELIBBAD;
 762
 763        size = sizeof(*loadmap) + nloads * sizeof(*seg);
 764        loadmap = kzalloc(size, GFP_KERNEL);
 765        if (!loadmap)
 766                return -ENOMEM;
 767
 768        params->loadmap = loadmap;
 769
 770        loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 771        loadmap->nsegs = nloads;
 772
 773        load_addr = params->load_addr;
 774        seg = loadmap->segs;
 775
 776        /* map the requested LOADs into the memory space */
 777        switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 778        case ELF_FDPIC_FLAG_CONSTDISP:
 779        case ELF_FDPIC_FLAG_CONTIGUOUS:
 780#ifndef CONFIG_MMU
 781                ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 782                if (ret < 0)
 783                        return ret;
 784                break;
 785#endif
 786        default:
 787                ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 788                if (ret < 0)
 789                        return ret;
 790                break;
 791        }
 792
 793        /* map the entry point */
 794        if (params->hdr.e_entry) {
 795                seg = loadmap->segs;
 796                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 797                        if (params->hdr.e_entry >= seg->p_vaddr &&
 798                            params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 799                                params->entry_addr =
 800                                        (params->hdr.e_entry - seg->p_vaddr) +
 801                                        seg->addr;
 802                                break;
 803                        }
 804                }
 805        }
 806
 807        /* determine where the program header table has wound up if mapped */
 808        stop = params->hdr.e_phoff;
 809        stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 810        phdr = params->phdrs;
 811
 812        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 813                if (phdr->p_type != PT_LOAD)
 814                        continue;
 815
 816                if (phdr->p_offset > params->hdr.e_phoff ||
 817                    phdr->p_offset + phdr->p_filesz < stop)
 818                        continue;
 819
 820                seg = loadmap->segs;
 821                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 822                        if (phdr->p_vaddr >= seg->p_vaddr &&
 823                            phdr->p_vaddr + phdr->p_filesz <=
 824                            seg->p_vaddr + seg->p_memsz) {
 825                                params->ph_addr =
 826                                        (phdr->p_vaddr - seg->p_vaddr) +
 827                                        seg->addr +
 828                                        params->hdr.e_phoff - phdr->p_offset;
 829                                break;
 830                        }
 831                }
 832                break;
 833        }
 834
 835        /* determine where the dynamic section has wound up if there is one */
 836        phdr = params->phdrs;
 837        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 838                if (phdr->p_type != PT_DYNAMIC)
 839                        continue;
 840
 841                seg = loadmap->segs;
 842                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 843                        if (phdr->p_vaddr >= seg->p_vaddr &&
 844                            phdr->p_vaddr + phdr->p_memsz <=
 845                            seg->p_vaddr + seg->p_memsz) {
 846                                params->dynamic_addr =
 847                                        (phdr->p_vaddr - seg->p_vaddr) +
 848                                        seg->addr;
 849
 850                                /* check the dynamic section contains at least
 851                                 * one item, and that the last item is a NULL
 852                                 * entry */
 853                                if (phdr->p_memsz == 0 ||
 854                                    phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 855                                        goto dynamic_error;
 856
 857                                tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 858                                if (((Elf32_Dyn *)
 859                                     params->dynamic_addr)[tmp - 1].d_tag != 0)
 860                                        goto dynamic_error;
 861                                break;
 862                        }
 863                }
 864                break;
 865        }
 866
 867        /* now elide adjacent segments in the load map on MMU linux
 868         * - on uClinux the holes between may actually be filled with system
 869         *   stuff or stuff from other processes
 870         */
 871#ifdef CONFIG_MMU
 872        nloads = loadmap->nsegs;
 873        mseg = loadmap->segs;
 874        seg = mseg + 1;
 875        for (loop = 1; loop < nloads; loop++) {
 876                /* see if we have a candidate for merging */
 877                if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 878                        load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 879                        if (load_addr == (seg->addr & PAGE_MASK)) {
 880                                mseg->p_memsz +=
 881                                        load_addr -
 882                                        (mseg->addr + mseg->p_memsz);
 883                                mseg->p_memsz += seg->addr & ~PAGE_MASK;
 884                                mseg->p_memsz += seg->p_memsz;
 885                                loadmap->nsegs--;
 886                                continue;
 887                        }
 888                }
 889
 890                mseg++;
 891                if (mseg != seg)
 892                        *mseg = *seg;
 893        }
 894#endif
 895
 896        kdebug("Mapped Object [%s]:", what);
 897        kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 898        kdebug("- entry    : %lx", params->entry_addr);
 899        kdebug("- PHDR[]   : %lx", params->ph_addr);
 900        kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 901        seg = loadmap->segs;
 902        for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 903                kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 904                       loop,
 905                       seg->addr, seg->addr + seg->p_memsz - 1,
 906                       seg->p_vaddr, seg->p_memsz);
 907
 908        return 0;
 909
 910dynamic_error:
 911        printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 912               what, file_inode(file)->i_ino);
 913        return -ELIBBAD;
 914}
 915
 916/*****************************************************************************/
 917/*
 918 * map a file with constant displacement under uClinux
 919 */
 920#ifndef CONFIG_MMU
 921static int elf_fdpic_map_file_constdisp_on_uclinux(
 922        struct elf_fdpic_params *params,
 923        struct file *file,
 924        struct mm_struct *mm)
 925{
 926        struct elf32_fdpic_loadseg *seg;
 927        struct elf32_phdr *phdr;
 928        unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
 929        int loop, ret;
 930
 931        load_addr = params->load_addr;
 932        seg = params->loadmap->segs;
 933
 934        /* determine the bounds of the contiguous overall allocation we must
 935         * make */
 936        phdr = params->phdrs;
 937        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 938                if (params->phdrs[loop].p_type != PT_LOAD)
 939                        continue;
 940
 941                if (base > phdr->p_vaddr)
 942                        base = phdr->p_vaddr;
 943                if (top < phdr->p_vaddr + phdr->p_memsz)
 944                        top = phdr->p_vaddr + phdr->p_memsz;
 945        }
 946
 947        /* allocate one big anon block for everything */
 948        mflags = MAP_PRIVATE;
 949        if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
 950                mflags |= MAP_EXECUTABLE;
 951
 952        maddr = vm_mmap(NULL, load_addr, top - base,
 953                        PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
 954        if (IS_ERR_VALUE(maddr))
 955                return (int) maddr;
 956
 957        if (load_addr != 0)
 958                load_addr += PAGE_ALIGN(top - base);
 959
 960        /* and then load the file segments into it */
 961        phdr = params->phdrs;
 962        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 963                if (params->phdrs[loop].p_type != PT_LOAD)
 964                        continue;
 965
 966                seg->addr = maddr + (phdr->p_vaddr - base);
 967                seg->p_vaddr = phdr->p_vaddr;
 968                seg->p_memsz = phdr->p_memsz;
 969
 970                ret = read_code(file, seg->addr, phdr->p_offset,
 971                                       phdr->p_filesz);
 972                if (ret < 0)
 973                        return ret;
 974
 975                /* map the ELF header address if in this segment */
 976                if (phdr->p_offset == 0)
 977                        params->elfhdr_addr = seg->addr;
 978
 979                /* clear any space allocated but not loaded */
 980                if (phdr->p_filesz < phdr->p_memsz) {
 981                        if (clear_user((void *) (seg->addr + phdr->p_filesz),
 982                                       phdr->p_memsz - phdr->p_filesz))
 983                                return -EFAULT;
 984                }
 985
 986                if (mm) {
 987                        if (phdr->p_flags & PF_X) {
 988                                if (!mm->start_code) {
 989                                        mm->start_code = seg->addr;
 990                                        mm->end_code = seg->addr +
 991                                                phdr->p_memsz;
 992                                }
 993                        } else if (!mm->start_data) {
 994                                mm->start_data = seg->addr;
 995                                mm->end_data = seg->addr + phdr->p_memsz;
 996                        }
 997                }
 998
 999                seg++;
1000        }
1001
1002        return 0;
1003}
1004#endif
1005
1006/*****************************************************************************/
1007/*
1008 * map a binary by direct mmap() of the individual PT_LOAD segments
1009 */
1010static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1011                                             struct file *file,
1012                                             struct mm_struct *mm)
1013{
1014        struct elf32_fdpic_loadseg *seg;
1015        struct elf32_phdr *phdr;
1016        unsigned long load_addr, delta_vaddr;
1017        int loop, dvset;
1018
1019        load_addr = params->load_addr;
1020        delta_vaddr = 0;
1021        dvset = 0;
1022
1023        seg = params->loadmap->segs;
1024
1025        /* deal with each load segment separately */
1026        phdr = params->phdrs;
1027        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1028                unsigned long maddr, disp, excess, excess1;
1029                int prot = 0, flags;
1030
1031                if (phdr->p_type != PT_LOAD)
1032                        continue;
1033
1034                kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1035                       (unsigned long) phdr->p_vaddr,
1036                       (unsigned long) phdr->p_offset,
1037                       (unsigned long) phdr->p_filesz,
1038                       (unsigned long) phdr->p_memsz);
1039
1040                /* determine the mapping parameters */
1041                if (phdr->p_flags & PF_R) prot |= PROT_READ;
1042                if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1043                if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1044
1045                flags = MAP_PRIVATE | MAP_DENYWRITE;
1046                if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1047                        flags |= MAP_EXECUTABLE;
1048
1049                maddr = 0;
1050
1051                switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1052                case ELF_FDPIC_FLAG_INDEPENDENT:
1053                        /* PT_LOADs are independently locatable */
1054                        break;
1055
1056                case ELF_FDPIC_FLAG_HONOURVADDR:
1057                        /* the specified virtual address must be honoured */
1058                        maddr = phdr->p_vaddr;
1059                        flags |= MAP_FIXED;
1060                        break;
1061
1062                case ELF_FDPIC_FLAG_CONSTDISP:
1063                        /* constant displacement
1064                         * - can be mapped anywhere, but must be mapped as a
1065                         *   unit
1066                         */
1067                        if (!dvset) {
1068                                maddr = load_addr;
1069                                delta_vaddr = phdr->p_vaddr;
1070                                dvset = 1;
1071                        } else {
1072                                maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1073                                flags |= MAP_FIXED;
1074                        }
1075                        break;
1076
1077                case ELF_FDPIC_FLAG_CONTIGUOUS:
1078                        /* contiguity handled later */
1079                        break;
1080
1081                default:
1082                        BUG();
1083                }
1084
1085                maddr &= PAGE_MASK;
1086
1087                /* create the mapping */
1088                disp = phdr->p_vaddr & ~PAGE_MASK;
1089                maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1090                                phdr->p_offset - disp);
1091
1092                kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1093                       loop, phdr->p_memsz + disp, prot, flags,
1094                       phdr->p_offset - disp, maddr);
1095
1096                if (IS_ERR_VALUE(maddr))
1097                        return (int) maddr;
1098
1099                if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1100                    ELF_FDPIC_FLAG_CONTIGUOUS)
1101                        load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1102
1103                seg->addr = maddr + disp;
1104                seg->p_vaddr = phdr->p_vaddr;
1105                seg->p_memsz = phdr->p_memsz;
1106
1107                /* map the ELF header address if in this segment */
1108                if (phdr->p_offset == 0)
1109                        params->elfhdr_addr = seg->addr;
1110
1111                /* clear the bit between beginning of mapping and beginning of
1112                 * PT_LOAD */
1113                if (prot & PROT_WRITE && disp > 0) {
1114                        kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1115                        if (clear_user((void __user *) maddr, disp))
1116                                return -EFAULT;
1117                        maddr += disp;
1118                }
1119
1120                /* clear any space allocated but not loaded
1121                 * - on uClinux we can just clear the lot
1122                 * - on MMU linux we'll get a SIGBUS beyond the last page
1123                 *   extant in the file
1124                 */
1125                excess = phdr->p_memsz - phdr->p_filesz;
1126                excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1127
1128#ifdef CONFIG_MMU
1129                if (excess > excess1) {
1130                        unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1131                        unsigned long xmaddr;
1132
1133                        flags |= MAP_FIXED | MAP_ANONYMOUS;
1134                        xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1135                                         prot, flags, 0);
1136
1137                        kdebug("mmap[%d] <anon>"
1138                               " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1139                               loop, xaddr, excess - excess1, prot, flags,
1140                               xmaddr);
1141
1142                        if (xmaddr != xaddr)
1143                                return -ENOMEM;
1144                }
1145
1146                if (prot & PROT_WRITE && excess1 > 0) {
1147                        kdebug("clear[%d] ad=%lx sz=%lx",
1148                               loop, maddr + phdr->p_filesz, excess1);
1149                        if (clear_user((void __user *) maddr + phdr->p_filesz,
1150                                       excess1))
1151                                return -EFAULT;
1152                }
1153
1154#else
1155                if (excess > 0) {
1156                        kdebug("clear[%d] ad=%lx sz=%lx",
1157                               loop, maddr + phdr->p_filesz, excess);
1158                        if (clear_user((void *) maddr + phdr->p_filesz, excess))
1159                                return -EFAULT;
1160                }
1161#endif
1162
1163                if (mm) {
1164                        if (phdr->p_flags & PF_X) {
1165                                if (!mm->start_code) {
1166                                        mm->start_code = maddr;
1167                                        mm->end_code = maddr + phdr->p_memsz;
1168                                }
1169                        } else if (!mm->start_data) {
1170                                mm->start_data = maddr;
1171                                mm->end_data = maddr + phdr->p_memsz;
1172                        }
1173                }
1174
1175                seg++;
1176        }
1177
1178        return 0;
1179}
1180
1181/*****************************************************************************/
1182/*
1183 * ELF-FDPIC core dumper
1184 *
1185 * Modelled on fs/exec.c:aout_core_dump()
1186 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1187 *
1188 * Modelled on fs/binfmt_elf.c core dumper
1189 */
1190#ifdef CONFIG_ELF_CORE
1191
1192/*
1193 * Decide whether a segment is worth dumping; default is yes to be
1194 * sure (missing info is worse than too much; etc).
1195 * Personally I'd include everything, and use the coredump limit...
1196 *
1197 * I think we should skip something. But I am not sure how. H.J.
1198 */
1199static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1200{
1201        int dump_ok;
1202
1203        /* Do not dump I/O mapped devices or special mappings */
1204        if (vma->vm_flags & VM_IO) {
1205                kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1206                return 0;
1207        }
1208
1209        /* If we may not read the contents, don't allow us to dump
1210         * them either. "dump_write()" can't handle it anyway.
1211         */
1212        if (!(vma->vm_flags & VM_READ)) {
1213                kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1214                return 0;
1215        }
1216
1217        /* By default, dump shared memory if mapped from an anonymous file. */
1218        if (vma->vm_flags & VM_SHARED) {
1219                if (file_inode(vma->vm_file)->i_nlink == 0) {
1220                        dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1221                        kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1222                               vma->vm_flags, dump_ok ? "yes" : "no");
1223                        return dump_ok;
1224                }
1225
1226                dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1227                kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1228                       vma->vm_flags, dump_ok ? "yes" : "no");
1229                return dump_ok;
1230        }
1231
1232#ifdef CONFIG_MMU
1233        /* By default, if it hasn't been written to, don't write it out */
1234        if (!vma->anon_vma) {
1235                dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1236                kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1237                       vma->vm_flags, dump_ok ? "yes" : "no");
1238                return dump_ok;
1239        }
1240#endif
1241
1242        dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1243        kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1244               dump_ok ? "yes" : "no");
1245        return dump_ok;
1246}
1247
1248/* An ELF note in memory */
1249struct memelfnote
1250{
1251        const char *name;
1252        int type;
1253        unsigned int datasz;
1254        void *data;
1255};
1256
1257static int notesize(struct memelfnote *en)
1258{
1259        int sz;
1260
1261        sz = sizeof(struct elf_note);
1262        sz += roundup(strlen(en->name) + 1, 4);
1263        sz += roundup(en->datasz, 4);
1264
1265        return sz;
1266}
1267
1268/* #define DEBUG */
1269
1270#define DUMP_WRITE(addr, nr, foffset)   \
1271        do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1272
1273static int alignfile(struct file *file, loff_t *foffset)
1274{
1275        static const char buf[4] = { 0, };
1276        DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1277        return 1;
1278}
1279
1280static int writenote(struct memelfnote *men, struct file *file,
1281                        loff_t *foffset)
1282{
1283        struct elf_note en;
1284        en.n_namesz = strlen(men->name) + 1;
1285        en.n_descsz = men->datasz;
1286        en.n_type = men->type;
1287
1288        DUMP_WRITE(&en, sizeof(en), foffset);
1289        DUMP_WRITE(men->name, en.n_namesz, foffset);
1290        if (!alignfile(file, foffset))
1291                return 0;
1292        DUMP_WRITE(men->data, men->datasz, foffset);
1293        if (!alignfile(file, foffset))
1294                return 0;
1295
1296        return 1;
1297}
1298#undef DUMP_WRITE
1299
1300static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1301{
1302        memcpy(elf->e_ident, ELFMAG, SELFMAG);
1303        elf->e_ident[EI_CLASS] = ELF_CLASS;
1304        elf->e_ident[EI_DATA] = ELF_DATA;
1305        elf->e_ident[EI_VERSION] = EV_CURRENT;
1306        elf->e_ident[EI_OSABI] = ELF_OSABI;
1307        memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1308
1309        elf->e_type = ET_CORE;
1310        elf->e_machine = ELF_ARCH;
1311        elf->e_version = EV_CURRENT;
1312        elf->e_entry = 0;
1313        elf->e_phoff = sizeof(struct elfhdr);
1314        elf->e_shoff = 0;
1315        elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1316        elf->e_ehsize = sizeof(struct elfhdr);
1317        elf->e_phentsize = sizeof(struct elf_phdr);
1318        elf->e_phnum = segs;
1319        elf->e_shentsize = 0;
1320        elf->e_shnum = 0;
1321        elf->e_shstrndx = 0;
1322        return;
1323}
1324
1325static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1326{
1327        phdr->p_type = PT_NOTE;
1328        phdr->p_offset = offset;
1329        phdr->p_vaddr = 0;
1330        phdr->p_paddr = 0;
1331        phdr->p_filesz = sz;
1332        phdr->p_memsz = 0;
1333        phdr->p_flags = 0;
1334        phdr->p_align = 0;
1335        return;
1336}
1337
1338static inline void fill_note(struct memelfnote *note, const char *name, int type,
1339                unsigned int sz, void *data)
1340{
1341        note->name = name;
1342        note->type = type;
1343        note->datasz = sz;
1344        note->data = data;
1345        return;
1346}
1347
1348/*
1349 * fill up all the fields in prstatus from the given task struct, except
1350 * registers which need to be filled up separately.
1351 */
1352static void fill_prstatus(struct elf_prstatus *prstatus,
1353                          struct task_struct *p, long signr)
1354{
1355        prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1356        prstatus->pr_sigpend = p->pending.signal.sig[0];
1357        prstatus->pr_sighold = p->blocked.sig[0];
1358        rcu_read_lock();
1359        prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1360        rcu_read_unlock();
1361        prstatus->pr_pid = task_pid_vnr(p);
1362        prstatus->pr_pgrp = task_pgrp_vnr(p);
1363        prstatus->pr_sid = task_session_vnr(p);
1364        if (thread_group_leader(p)) {
1365                struct task_cputime cputime;
1366
1367                /*
1368                 * This is the record for the group leader.  It shows the
1369                 * group-wide total, not its individual thread total.
1370                 */
1371                thread_group_cputime(p, &cputime);
1372                cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1373                cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1374        } else {
1375                cputime_t utime, stime;
1376
1377                task_cputime(p, &utime, &stime);
1378                cputime_to_timeval(utime, &prstatus->pr_utime);
1379                cputime_to_timeval(stime, &prstatus->pr_stime);
1380        }
1381        cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1382        cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1383
1384        prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1385        prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1386}
1387
1388static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1389                       struct mm_struct *mm)
1390{
1391        const struct cred *cred;
1392        unsigned int i, len;
1393
1394        /* first copy the parameters from user space */
1395        memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1396
1397        len = mm->arg_end - mm->arg_start;
1398        if (len >= ELF_PRARGSZ)
1399                len = ELF_PRARGSZ - 1;
1400        if (copy_from_user(&psinfo->pr_psargs,
1401                           (const char __user *) mm->arg_start, len))
1402                return -EFAULT;
1403        for (i = 0; i < len; i++)
1404                if (psinfo->pr_psargs[i] == 0)
1405                        psinfo->pr_psargs[i] = ' ';
1406        psinfo->pr_psargs[len] = 0;
1407
1408        rcu_read_lock();
1409        psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1410        rcu_read_unlock();
1411        psinfo->pr_pid = task_pid_vnr(p);
1412        psinfo->pr_pgrp = task_pgrp_vnr(p);
1413        psinfo->pr_sid = task_session_vnr(p);
1414
1415        i = p->state ? ffz(~p->state) + 1 : 0;
1416        psinfo->pr_state = i;
1417        psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1418        psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1419        psinfo->pr_nice = task_nice(p);
1420        psinfo->pr_flag = p->flags;
1421        rcu_read_lock();
1422        cred = __task_cred(p);
1423        SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1424        SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1425        rcu_read_unlock();
1426        strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1427
1428        return 0;
1429}
1430
1431/* Here is the structure in which status of each thread is captured. */
1432struct elf_thread_status
1433{
1434        struct list_head list;
1435        struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1436        elf_fpregset_t fpu;             /* NT_PRFPREG */
1437        struct task_struct *thread;
1438#ifdef ELF_CORE_COPY_XFPREGS
1439        elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1440#endif
1441        struct memelfnote notes[3];
1442        int num_notes;
1443};
1444
1445/*
1446 * In order to add the specific thread information for the elf file format,
1447 * we need to keep a linked list of every thread's pr_status and then create
1448 * a single section for them in the final core file.
1449 */
1450static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1451{
1452        struct task_struct *p = t->thread;
1453        int sz = 0;
1454
1455        t->num_notes = 0;
1456
1457        fill_prstatus(&t->prstatus, p, signr);
1458        elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1459
1460        fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1461                  &t->prstatus);
1462        t->num_notes++;
1463        sz += notesize(&t->notes[0]);
1464
1465        t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1466        if (t->prstatus.pr_fpvalid) {
1467                fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1468                          &t->fpu);
1469                t->num_notes++;
1470                sz += notesize(&t->notes[1]);
1471        }
1472
1473#ifdef ELF_CORE_COPY_XFPREGS
1474        if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1475                fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1476                          sizeof(t->xfpu), &t->xfpu);
1477                t->num_notes++;
1478                sz += notesize(&t->notes[2]);
1479        }
1480#endif
1481        return sz;
1482}
1483
1484static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1485                             elf_addr_t e_shoff, int segs)
1486{
1487        elf->e_shoff = e_shoff;
1488        elf->e_shentsize = sizeof(*shdr4extnum);
1489        elf->e_shnum = 1;
1490        elf->e_shstrndx = SHN_UNDEF;
1491
1492        memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1493
1494        shdr4extnum->sh_type = SHT_NULL;
1495        shdr4extnum->sh_size = elf->e_shnum;
1496        shdr4extnum->sh_link = elf->e_shstrndx;
1497        shdr4extnum->sh_info = segs;
1498}
1499
1500/*
1501 * dump the segments for an MMU process
1502 */
1503#ifdef CONFIG_MMU
1504static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1505                           unsigned long *limit, unsigned long mm_flags)
1506{
1507        struct vm_area_struct *vma;
1508        int err = 0;
1509
1510        for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1511                unsigned long addr;
1512
1513                if (!maydump(vma, mm_flags))
1514                        continue;
1515
1516                for (addr = vma->vm_start; addr < vma->vm_end;
1517                                                        addr += PAGE_SIZE) {
1518                        struct page *page = get_dump_page(addr);
1519                        if (page) {
1520                                void *kaddr = kmap(page);
1521                                *size += PAGE_SIZE;
1522                                if (*size > *limit)
1523                                        err = -EFBIG;
1524                                else if (!dump_write(file, kaddr, PAGE_SIZE))
1525                                        err = -EIO;
1526                                kunmap(page);
1527                                page_cache_release(page);
1528                        } else if (!dump_seek(file, PAGE_SIZE))
1529                                err = -EFBIG;
1530                        if (err)
1531                                goto out;
1532                }
1533        }
1534out:
1535        return err;
1536}
1537#endif
1538
1539/*
1540 * dump the segments for a NOMMU process
1541 */
1542#ifndef CONFIG_MMU
1543static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1544                           unsigned long *limit, unsigned long mm_flags)
1545{
1546        struct vm_area_struct *vma;
1547
1548        for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1549                if (!maydump(vma, mm_flags))
1550                        continue;
1551
1552                if ((*size += PAGE_SIZE) > *limit)
1553                        return -EFBIG;
1554
1555                if (!dump_write(file, (void *) vma->vm_start,
1556                                vma->vm_end - vma->vm_start))
1557                        return -EIO;
1558        }
1559
1560        return 0;
1561}
1562#endif
1563
1564static size_t elf_core_vma_data_size(unsigned long mm_flags)
1565{
1566        struct vm_area_struct *vma;
1567        size_t size = 0;
1568
1569        for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1570                if (maydump(vma, mm_flags))
1571                        size += vma->vm_end - vma->vm_start;
1572        return size;
1573}
1574
1575/*
1576 * Actual dumper
1577 *
1578 * This is a two-pass process; first we find the offsets of the bits,
1579 * and then they are actually written out.  If we run out of core limit
1580 * we just truncate.
1581 */
1582static int elf_fdpic_core_dump(struct coredump_params *cprm)
1583{
1584#define NUM_NOTES       6
1585        int has_dumped = 0;
1586        mm_segment_t fs;
1587        int segs;
1588        size_t size = 0;
1589        int i;
1590        struct vm_area_struct *vma;
1591        struct elfhdr *elf = NULL;
1592        loff_t offset = 0, dataoff, foffset;
1593        int numnote;
1594        struct memelfnote *notes = NULL;
1595        struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1596        struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1597        LIST_HEAD(thread_list);
1598        struct list_head *t;
1599        elf_fpregset_t *fpu = NULL;
1600#ifdef ELF_CORE_COPY_XFPREGS
1601        elf_fpxregset_t *xfpu = NULL;
1602#endif
1603        int thread_status_size = 0;
1604        elf_addr_t *auxv;
1605        struct elf_phdr *phdr4note = NULL;
1606        struct elf_shdr *shdr4extnum = NULL;
1607        Elf_Half e_phnum;
1608        elf_addr_t e_shoff;
1609
1610        /*
1611         * We no longer stop all VM operations.
1612         *
1613         * This is because those proceses that could possibly change map_count
1614         * or the mmap / vma pages are now blocked in do_exit on current
1615         * finishing this core dump.
1616         *
1617         * Only ptrace can touch these memory addresses, but it doesn't change
1618         * the map_count or the pages allocated. So no possibility of crashing
1619         * exists while dumping the mm->vm_next areas to the core file.
1620         */
1621
1622        /* alloc memory for large data structures: too large to be on stack */
1623        elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1624        if (!elf)
1625                goto cleanup;
1626        prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1627        if (!prstatus)
1628                goto cleanup;
1629        psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1630        if (!psinfo)
1631                goto cleanup;
1632        notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1633        if (!notes)
1634                goto cleanup;
1635        fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1636        if (!fpu)
1637                goto cleanup;
1638#ifdef ELF_CORE_COPY_XFPREGS
1639        xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1640        if (!xfpu)
1641                goto cleanup;
1642#endif
1643
1644        if (cprm->siginfo->si_signo) {
1645                struct core_thread *ct;
1646                struct elf_thread_status *tmp;
1647
1648                for (ct = current->mm->core_state->dumper.next;
1649                                                ct; ct = ct->next) {
1650                        tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1651                        if (!tmp)
1652                                goto cleanup;
1653
1654                        tmp->thread = ct->task;
1655                        list_add(&tmp->list, &thread_list);
1656                }
1657
1658                list_for_each(t, &thread_list) {
1659                        struct elf_thread_status *tmp;
1660                        int sz;
1661
1662                        tmp = list_entry(t, struct elf_thread_status, list);
1663                        sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1664                        thread_status_size += sz;
1665                }
1666        }
1667
1668        /* now collect the dump for the current */
1669        fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1670        elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1671
1672        segs = current->mm->map_count;
1673        segs += elf_core_extra_phdrs();
1674
1675        /* for notes section */
1676        segs++;
1677
1678        /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1679         * this, kernel supports extended numbering. Have a look at
1680         * include/linux/elf.h for further information. */
1681        e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1682
1683        /* Set up header */
1684        fill_elf_fdpic_header(elf, e_phnum);
1685
1686        has_dumped = 1;
1687        /*
1688         * Set up the notes in similar form to SVR4 core dumps made
1689         * with info from their /proc.
1690         */
1691
1692        fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1693        fill_psinfo(psinfo, current->group_leader, current->mm);
1694        fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1695
1696        numnote = 2;
1697
1698        auxv = (elf_addr_t *) current->mm->saved_auxv;
1699
1700        i = 0;
1701        do
1702                i += 2;
1703        while (auxv[i - 2] != AT_NULL);
1704        fill_note(&notes[numnote++], "CORE", NT_AUXV,
1705                  i * sizeof(elf_addr_t), auxv);
1706
1707        /* Try to dump the FPU. */
1708        if ((prstatus->pr_fpvalid =
1709             elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1710                fill_note(notes + numnote++,
1711                          "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1712#ifdef ELF_CORE_COPY_XFPREGS
1713        if (elf_core_copy_task_xfpregs(current, xfpu))
1714                fill_note(notes + numnote++,
1715                          "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1716#endif
1717
1718        fs = get_fs();
1719        set_fs(KERNEL_DS);
1720
1721        offset += sizeof(*elf);                         /* Elf header */
1722        offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1723        foffset = offset;
1724
1725        /* Write notes phdr entry */
1726        {
1727                int sz = 0;
1728
1729                for (i = 0; i < numnote; i++)
1730                        sz += notesize(notes + i);
1731
1732                sz += thread_status_size;
1733
1734                phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1735                if (!phdr4note)
1736                        goto end_coredump;
1737
1738                fill_elf_note_phdr(phdr4note, sz, offset);
1739                offset += sz;
1740        }
1741
1742        /* Page-align dumped data */
1743        dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1744
1745        offset += elf_core_vma_data_size(cprm->mm_flags);
1746        offset += elf_core_extra_data_size();
1747        e_shoff = offset;
1748
1749        if (e_phnum == PN_XNUM) {
1750                shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1751                if (!shdr4extnum)
1752                        goto end_coredump;
1753                fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1754        }
1755
1756        offset = dataoff;
1757
1758        size += sizeof(*elf);
1759        if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1760                goto end_coredump;
1761
1762        size += sizeof(*phdr4note);
1763        if (size > cprm->limit
1764            || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1765                goto end_coredump;
1766
1767        /* write program headers for segments dump */
1768        for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1769                struct elf_phdr phdr;
1770                size_t sz;
1771
1772                sz = vma->vm_end - vma->vm_start;
1773
1774                phdr.p_type = PT_LOAD;
1775                phdr.p_offset = offset;
1776                phdr.p_vaddr = vma->vm_start;
1777                phdr.p_paddr = 0;
1778                phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1779                phdr.p_memsz = sz;
1780                offset += phdr.p_filesz;
1781                phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1782                if (vma->vm_flags & VM_WRITE)
1783                        phdr.p_flags |= PF_W;
1784                if (vma->vm_flags & VM_EXEC)
1785                        phdr.p_flags |= PF_X;
1786                phdr.p_align = ELF_EXEC_PAGESIZE;
1787
1788                size += sizeof(phdr);
1789                if (size > cprm->limit
1790                    || !dump_write(cprm->file, &phdr, sizeof(phdr)))
1791                        goto end_coredump;
1792        }
1793
1794        if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
1795                goto end_coredump;
1796
1797        /* write out the notes section */
1798        for (i = 0; i < numnote; i++)
1799                if (!writenote(notes + i, cprm->file, &foffset))
1800                        goto end_coredump;
1801
1802        /* write out the thread status notes section */
1803        list_for_each(t, &thread_list) {
1804                struct elf_thread_status *tmp =
1805                                list_entry(t, struct elf_thread_status, list);
1806
1807                for (i = 0; i < tmp->num_notes; i++)
1808                        if (!writenote(&tmp->notes[i], cprm->file, &foffset))
1809                                goto end_coredump;
1810        }
1811
1812        if (!dump_seek(cprm->file, dataoff - foffset))
1813                goto end_coredump;
1814
1815        if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit,
1816                                    cprm->mm_flags) < 0)
1817                goto end_coredump;
1818
1819        if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
1820                goto end_coredump;
1821
1822        if (e_phnum == PN_XNUM) {
1823                size += sizeof(*shdr4extnum);
1824                if (size > cprm->limit
1825                    || !dump_write(cprm->file, shdr4extnum,
1826                                   sizeof(*shdr4extnum)))
1827                        goto end_coredump;
1828        }
1829
1830        if (cprm->file->f_pos != offset) {
1831                /* Sanity check */
1832                printk(KERN_WARNING
1833                       "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1834                       cprm->file->f_pos, offset);
1835        }
1836
1837end_coredump:
1838        set_fs(fs);
1839
1840cleanup:
1841        while (!list_empty(&thread_list)) {
1842                struct list_head *tmp = thread_list.next;
1843                list_del(tmp);
1844                kfree(list_entry(tmp, struct elf_thread_status, list));
1845        }
1846        kfree(phdr4note);
1847        kfree(elf);
1848        kfree(prstatus);
1849        kfree(psinfo);
1850        kfree(notes);
1851        kfree(fpu);
1852        kfree(shdr4extnum);
1853#ifdef ELF_CORE_COPY_XFPREGS
1854        kfree(xfpu);
1855#endif
1856        return has_dumped;
1857#undef NUM_NOTES
1858}
1859
1860#endif          /* CONFIG_ELF_CORE */
1861
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