linux/fs/binfmt_elf_fdpic.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* binfmt_elf_fdpic.c: FDPIC ELF binary format
   3 *
   4 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
   5 * Written by David Howells (dhowells@redhat.com)
   6 * Derived from binfmt_elf.c
   7 */
   8
   9#include <linux/module.h>
  10
  11#include <linux/fs.h>
  12#include <linux/stat.h>
  13#include <linux/sched.h>
  14#include <linux/sched/coredump.h>
  15#include <linux/sched/task_stack.h>
  16#include <linux/sched/cputime.h>
  17#include <linux/mm.h>
  18#include <linux/mman.h>
  19#include <linux/errno.h>
  20#include <linux/signal.h>
  21#include <linux/binfmts.h>
  22#include <linux/string.h>
  23#include <linux/file.h>
  24#include <linux/fcntl.h>
  25#include <linux/slab.h>
  26#include <linux/pagemap.h>
  27#include <linux/security.h>
  28#include <linux/highmem.h>
  29#include <linux/highuid.h>
  30#include <linux/personality.h>
  31#include <linux/ptrace.h>
  32#include <linux/init.h>
  33#include <linux/elf.h>
  34#include <linux/elf-fdpic.h>
  35#include <linux/elfcore.h>
  36#include <linux/coredump.h>
  37#include <linux/dax.h>
  38#include <linux/regset.h>
  39
  40#include <linux/uaccess.h>
  41#include <asm/param.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_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  70                                                   struct file *,
  71                                                   struct mm_struct *);
  72#endif
  73
  74static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  75                                             struct file *, struct mm_struct *);
  76
  77#ifdef CONFIG_ELF_CORE
  78static int elf_fdpic_core_dump(struct coredump_params *cprm);
  79#endif
  80
  81static struct linux_binfmt elf_fdpic_format = {
  82        .module         = THIS_MODULE,
  83        .load_binary    = load_elf_fdpic_binary,
  84#ifdef CONFIG_ELF_CORE
  85        .core_dump      = elf_fdpic_core_dump,
  86#endif
  87        .min_coredump   = ELF_EXEC_PAGESIZE,
  88};
  89
  90static int __init init_elf_fdpic_binfmt(void)
  91{
  92        register_binfmt(&elf_fdpic_format);
  93        return 0;
  94}
  95
  96static void __exit exit_elf_fdpic_binfmt(void)
  97{
  98        unregister_binfmt(&elf_fdpic_format);
  99}
 100
 101core_initcall(init_elf_fdpic_binfmt);
 102module_exit(exit_elf_fdpic_binfmt);
 103
 104static int is_elf(struct elfhdr *hdr, struct file *file)
 105{
 106        if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 107                return 0;
 108        if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 109                return 0;
 110        if (!elf_check_arch(hdr))
 111                return 0;
 112        if (!file->f_op->mmap)
 113                return 0;
 114        return 1;
 115}
 116
 117#ifndef elf_check_fdpic
 118#define elf_check_fdpic(x) 0
 119#endif
 120
 121#ifndef elf_check_const_displacement
 122#define elf_check_const_displacement(x) 0
 123#endif
 124
 125static int is_constdisp(struct elfhdr *hdr)
 126{
 127        if (!elf_check_fdpic(hdr))
 128                return 1;
 129        if (elf_check_const_displacement(hdr))
 130                return 1;
 131        return 0;
 132}
 133
 134/*****************************************************************************/
 135/*
 136 * read the program headers table into memory
 137 */
 138static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 139                                 struct file *file)
 140{
 141        struct elf32_phdr *phdr;
 142        unsigned long size;
 143        int retval, loop;
 144        loff_t pos = params->hdr.e_phoff;
 145
 146        if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 147                return -ENOMEM;
 148        if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 149                return -ENOMEM;
 150
 151        size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 152        params->phdrs = kmalloc(size, GFP_KERNEL);
 153        if (!params->phdrs)
 154                return -ENOMEM;
 155
 156        retval = kernel_read(file, params->phdrs, size, &pos);
 157        if (unlikely(retval != size))
 158                return retval < 0 ? retval : -ENOEXEC;
 159
 160        /* determine stack size for this binary */
 161        phdr = params->phdrs;
 162        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 163                if (phdr->p_type != PT_GNU_STACK)
 164                        continue;
 165
 166                if (phdr->p_flags & PF_X)
 167                        params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 168                else
 169                        params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 170
 171                params->stack_size = phdr->p_memsz;
 172                break;
 173        }
 174
 175        return 0;
 176}
 177
 178/*****************************************************************************/
 179/*
 180 * load an fdpic binary into various bits of memory
 181 */
 182static int load_elf_fdpic_binary(struct linux_binprm *bprm)
 183{
 184        struct elf_fdpic_params exec_params, interp_params;
 185        struct pt_regs *regs = current_pt_regs();
 186        struct elf_phdr *phdr;
 187        unsigned long stack_size, entryaddr;
 188#ifdef ELF_FDPIC_PLAT_INIT
 189        unsigned long dynaddr;
 190#endif
 191#ifndef CONFIG_MMU
 192        unsigned long stack_prot;
 193#endif
 194        struct file *interpreter = NULL; /* to shut gcc up */
 195        char *interpreter_name = NULL;
 196        int executable_stack;
 197        int retval, i;
 198        loff_t pos;
 199
 200        kdebug("____ LOAD %d ____", current->pid);
 201
 202        memset(&exec_params, 0, sizeof(exec_params));
 203        memset(&interp_params, 0, sizeof(interp_params));
 204
 205        exec_params.hdr = *(struct elfhdr *) bprm->buf;
 206        exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 207
 208        /* check that this is a binary we know how to deal with */
 209        retval = -ENOEXEC;
 210        if (!is_elf(&exec_params.hdr, bprm->file))
 211                goto error;
 212        if (!elf_check_fdpic(&exec_params.hdr)) {
 213#ifdef CONFIG_MMU
 214                /* binfmt_elf handles non-fdpic elf except on nommu */
 215                goto error;
 216#else
 217                /* nommu can only load ET_DYN (PIE) ELF */
 218                if (exec_params.hdr.e_type != ET_DYN)
 219                        goto error;
 220#endif
 221        }
 222
 223        /* read the program header table */
 224        retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 225        if (retval < 0)
 226                goto error;
 227
 228        /* scan for a program header that specifies an interpreter */
 229        phdr = exec_params.phdrs;
 230
 231        for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 232                switch (phdr->p_type) {
 233                case PT_INTERP:
 234                        retval = -ENOMEM;
 235                        if (phdr->p_filesz > PATH_MAX)
 236                                goto error;
 237                        retval = -ENOENT;
 238                        if (phdr->p_filesz < 2)
 239                                goto error;
 240
 241                        /* read the name of the interpreter into memory */
 242                        interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 243                        if (!interpreter_name)
 244                                goto error;
 245
 246                        pos = phdr->p_offset;
 247                        retval = kernel_read(bprm->file, interpreter_name,
 248                                             phdr->p_filesz, &pos);
 249                        if (unlikely(retval != phdr->p_filesz)) {
 250                                if (retval >= 0)
 251                                        retval = -ENOEXEC;
 252                                goto error;
 253                        }
 254
 255                        retval = -ENOENT;
 256                        if (interpreter_name[phdr->p_filesz - 1] != '\0')
 257                                goto error;
 258
 259                        kdebug("Using ELF interpreter %s", interpreter_name);
 260
 261                        /* replace the program with the interpreter */
 262                        interpreter = open_exec(interpreter_name);
 263                        retval = PTR_ERR(interpreter);
 264                        if (IS_ERR(interpreter)) {
 265                                interpreter = NULL;
 266                                goto error;
 267                        }
 268
 269                        /*
 270                         * If the binary is not readable then enforce
 271                         * mm->dumpable = 0 regardless of the interpreter's
 272                         * permissions.
 273                         */
 274                        would_dump(bprm, interpreter);
 275
 276                        pos = 0;
 277                        retval = kernel_read(interpreter, bprm->buf,
 278                                        BINPRM_BUF_SIZE, &pos);
 279                        if (unlikely(retval != BINPRM_BUF_SIZE)) {
 280                                if (retval >= 0)
 281                                        retval = -ENOEXEC;
 282                                goto error;
 283                        }
 284
 285                        interp_params.hdr = *((struct elfhdr *) bprm->buf);
 286                        break;
 287
 288                case PT_LOAD:
 289#ifdef CONFIG_MMU
 290                        if (exec_params.load_addr == 0)
 291                                exec_params.load_addr = phdr->p_vaddr;
 292#endif
 293                        break;
 294                }
 295
 296        }
 297
 298        if (is_constdisp(&exec_params.hdr))
 299                exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 300
 301        /* perform insanity checks on the interpreter */
 302        if (interpreter_name) {
 303                retval = -ELIBBAD;
 304                if (!is_elf(&interp_params.hdr, interpreter))
 305                        goto error;
 306
 307                interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 308
 309                /* read the interpreter's program header table */
 310                retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 311                if (retval < 0)
 312                        goto error;
 313        }
 314
 315        stack_size = exec_params.stack_size;
 316        if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 317                executable_stack = EXSTACK_ENABLE_X;
 318        else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 319                executable_stack = EXSTACK_DISABLE_X;
 320        else
 321                executable_stack = EXSTACK_DEFAULT;
 322
 323        if (stack_size == 0) {
 324                stack_size = interp_params.stack_size;
 325                if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 326                        executable_stack = EXSTACK_ENABLE_X;
 327                else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 328                        executable_stack = EXSTACK_DISABLE_X;
 329                else
 330                        executable_stack = EXSTACK_DEFAULT;
 331        }
 332
 333        retval = -ENOEXEC;
 334        if (stack_size == 0)
 335                stack_size = 131072UL; /* same as exec.c's default commit */
 336
 337        if (is_constdisp(&interp_params.hdr))
 338                interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 339
 340        /* flush all traces of the currently running executable */
 341        retval = begin_new_exec(bprm);
 342        if (retval)
 343                goto error;
 344
 345        /* there's now no turning back... the old userspace image is dead,
 346         * defunct, deceased, etc.
 347         */
 348        if (elf_check_fdpic(&exec_params.hdr))
 349                set_personality(PER_LINUX_FDPIC);
 350        else
 351                set_personality(PER_LINUX);
 352        if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
 353                current->personality |= READ_IMPLIES_EXEC;
 354
 355        setup_new_exec(bprm);
 356
 357        set_binfmt(&elf_fdpic_format);
 358
 359        current->mm->start_code = 0;
 360        current->mm->end_code = 0;
 361        current->mm->start_stack = 0;
 362        current->mm->start_data = 0;
 363        current->mm->end_data = 0;
 364        current->mm->context.exec_fdpic_loadmap = 0;
 365        current->mm->context.interp_fdpic_loadmap = 0;
 366
 367#ifdef CONFIG_MMU
 368        elf_fdpic_arch_lay_out_mm(&exec_params,
 369                                  &interp_params,
 370                                  &current->mm->start_stack,
 371                                  &current->mm->start_brk);
 372
 373        retval = setup_arg_pages(bprm, current->mm->start_stack,
 374                                 executable_stack);
 375        if (retval < 0)
 376                goto error;
 377#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
 378        retval = arch_setup_additional_pages(bprm, !!interpreter_name);
 379        if (retval < 0)
 380                goto error;
 381#endif
 382#endif
 383
 384        /* load the executable and interpreter into memory */
 385        retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 386                                    "executable");
 387        if (retval < 0)
 388                goto error;
 389
 390        if (interpreter_name) {
 391                retval = elf_fdpic_map_file(&interp_params, interpreter,
 392                                            current->mm, "interpreter");
 393                if (retval < 0) {
 394                        printk(KERN_ERR "Unable to load interpreter\n");
 395                        goto error;
 396                }
 397
 398                allow_write_access(interpreter);
 399                fput(interpreter);
 400                interpreter = NULL;
 401        }
 402
 403#ifdef CONFIG_MMU
 404        if (!current->mm->start_brk)
 405                current->mm->start_brk = current->mm->end_data;
 406
 407        current->mm->brk = current->mm->start_brk =
 408                PAGE_ALIGN(current->mm->start_brk);
 409
 410#else
 411        /* create a stack area and zero-size brk area */
 412        stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 413        if (stack_size < PAGE_SIZE * 2)
 414                stack_size = PAGE_SIZE * 2;
 415
 416        stack_prot = PROT_READ | PROT_WRITE;
 417        if (executable_stack == EXSTACK_ENABLE_X ||
 418            (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 419                stack_prot |= PROT_EXEC;
 420
 421        current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 422                                         MAP_PRIVATE | MAP_ANONYMOUS |
 423                                         MAP_UNINITIALIZED | MAP_GROWSDOWN,
 424                                         0);
 425
 426        if (IS_ERR_VALUE(current->mm->start_brk)) {
 427                retval = current->mm->start_brk;
 428                current->mm->start_brk = 0;
 429                goto error;
 430        }
 431
 432        current->mm->brk = current->mm->start_brk;
 433        current->mm->context.end_brk = current->mm->start_brk;
 434        current->mm->start_stack = current->mm->start_brk + stack_size;
 435#endif
 436
 437        if (create_elf_fdpic_tables(bprm, current->mm,
 438                                    &exec_params, &interp_params) < 0)
 439                goto error;
 440
 441        kdebug("- start_code  %lx", current->mm->start_code);
 442        kdebug("- end_code    %lx", current->mm->end_code);
 443        kdebug("- start_data  %lx", current->mm->start_data);
 444        kdebug("- end_data    %lx", current->mm->end_data);
 445        kdebug("- start_brk   %lx", current->mm->start_brk);
 446        kdebug("- brk         %lx", current->mm->brk);
 447        kdebug("- start_stack %lx", current->mm->start_stack);
 448
 449#ifdef ELF_FDPIC_PLAT_INIT
 450        /*
 451         * The ABI may specify that certain registers be set up in special
 452         * ways (on i386 %edx is the address of a DT_FINI function, for
 453         * example.  This macro performs whatever initialization to
 454         * the regs structure is required.
 455         */
 456        dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 457        ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 458                            dynaddr);
 459#endif
 460
 461        finalize_exec(bprm);
 462        /* everything is now ready... get the userspace context ready to roll */
 463        entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 464        start_thread(regs, entryaddr, current->mm->start_stack);
 465
 466        retval = 0;
 467
 468error:
 469        if (interpreter) {
 470                allow_write_access(interpreter);
 471                fput(interpreter);
 472        }
 473        kfree(interpreter_name);
 474        kfree(exec_params.phdrs);
 475        kfree(exec_params.loadmap);
 476        kfree(interp_params.phdrs);
 477        kfree(interp_params.loadmap);
 478        return retval;
 479}
 480
 481/*****************************************************************************/
 482
 483#ifndef ELF_BASE_PLATFORM
 484/*
 485 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 486 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 487 * will be copied to the user stack in the same manner as AT_PLATFORM.
 488 */
 489#define ELF_BASE_PLATFORM NULL
 490#endif
 491
 492/*
 493 * present useful information to the program by shovelling it onto the new
 494 * process's stack
 495 */
 496static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 497                                   struct mm_struct *mm,
 498                                   struct elf_fdpic_params *exec_params,
 499                                   struct elf_fdpic_params *interp_params)
 500{
 501        const struct cred *cred = current_cred();
 502        unsigned long sp, csp, nitems;
 503        elf_caddr_t __user *argv, *envp;
 504        size_t platform_len = 0, len;
 505        char *k_platform, *k_base_platform;
 506        char __user *u_platform, *u_base_platform, *p;
 507        int loop;
 508        int nr; /* reset for each csp adjustment */
 509        unsigned long flags = 0;
 510
 511#ifdef CONFIG_MMU
 512        /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 513         * by the processes running on the same package. One thing we can do is
 514         * to shuffle the initial stack for them, so we give the architecture
 515         * an opportunity to do so here.
 516         */
 517        sp = arch_align_stack(bprm->p);
 518#else
 519        sp = mm->start_stack;
 520
 521        /* stack the program arguments and environment */
 522        if (transfer_args_to_stack(bprm, &sp) < 0)
 523                return -EFAULT;
 524        sp &= ~15;
 525#endif
 526
 527        /*
 528         * If this architecture has a platform capability string, copy it
 529         * to userspace.  In some cases (Sparc), this info is impossible
 530         * for userspace to get any other way, in others (i386) it is
 531         * merely difficult.
 532         */
 533        k_platform = ELF_PLATFORM;
 534        u_platform = NULL;
 535
 536        if (k_platform) {
 537                platform_len = strlen(k_platform) + 1;
 538                sp -= platform_len;
 539                u_platform = (char __user *) sp;
 540                if (copy_to_user(u_platform, k_platform, platform_len) != 0)
 541                        return -EFAULT;
 542        }
 543
 544        /*
 545         * If this architecture has a "base" platform capability
 546         * string, copy it to userspace.
 547         */
 548        k_base_platform = ELF_BASE_PLATFORM;
 549        u_base_platform = NULL;
 550
 551        if (k_base_platform) {
 552                platform_len = strlen(k_base_platform) + 1;
 553                sp -= platform_len;
 554                u_base_platform = (char __user *) sp;
 555                if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 556                        return -EFAULT;
 557        }
 558
 559        sp &= ~7UL;
 560
 561        /* stack the load map(s) */
 562        len = sizeof(struct elf32_fdpic_loadmap);
 563        len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
 564        sp = (sp - len) & ~7UL;
 565        exec_params->map_addr = sp;
 566
 567        if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 568                return -EFAULT;
 569
 570        current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 571
 572        if (interp_params->loadmap) {
 573                len = sizeof(struct elf32_fdpic_loadmap);
 574                len += sizeof(struct elf32_fdpic_loadseg) *
 575                        interp_params->loadmap->nsegs;
 576                sp = (sp - len) & ~7UL;
 577                interp_params->map_addr = sp;
 578
 579                if (copy_to_user((void __user *) sp, interp_params->loadmap,
 580                                 len) != 0)
 581                        return -EFAULT;
 582
 583                current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 584        }
 585
 586        /* force 16 byte _final_ alignment here for generality */
 587#define DLINFO_ITEMS 15
 588
 589        nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 590                (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 591
 592        if (bprm->have_execfd)
 593                nitems++;
 594
 595        csp = sp;
 596        sp -= nitems * 2 * sizeof(unsigned long);
 597        sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
 598        sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
 599        sp -= 1 * sizeof(unsigned long);                /* argc */
 600
 601        csp -= sp & 15UL;
 602        sp -= sp & 15UL;
 603
 604        /* put the ELF interpreter info on the stack */
 605#define NEW_AUX_ENT(id, val)                                            \
 606        do {                                                            \
 607                struct { unsigned long _id, _val; } __user *ent, v;     \
 608                                                                        \
 609                ent = (void __user *) csp;                              \
 610                v._id = (id);                                           \
 611                v._val = (val);                                         \
 612                if (copy_to_user(ent + nr, &v, sizeof(v)))              \
 613                        return -EFAULT;                                 \
 614                nr++;                                                   \
 615        } while (0)
 616
 617        nr = 0;
 618        csp -= 2 * sizeof(unsigned long);
 619        NEW_AUX_ENT(AT_NULL, 0);
 620        if (k_platform) {
 621                nr = 0;
 622                csp -= 2 * sizeof(unsigned long);
 623                NEW_AUX_ENT(AT_PLATFORM,
 624                            (elf_addr_t) (unsigned long) u_platform);
 625        }
 626
 627        if (k_base_platform) {
 628                nr = 0;
 629                csp -= 2 * sizeof(unsigned long);
 630                NEW_AUX_ENT(AT_BASE_PLATFORM,
 631                            (elf_addr_t) (unsigned long) u_base_platform);
 632        }
 633
 634        if (bprm->have_execfd) {
 635                nr = 0;
 636                csp -= 2 * sizeof(unsigned long);
 637                NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
 638        }
 639
 640        nr = 0;
 641        csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
 642        NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
 643#ifdef ELF_HWCAP2
 644        NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
 645#endif
 646        NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
 647        NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
 648        NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
 649        NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
 650        NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
 651        NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
 652        if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
 653                flags |= AT_FLAGS_PRESERVE_ARGV0;
 654        NEW_AUX_ENT(AT_FLAGS,   flags);
 655        NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
 656        NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 657        NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 658        NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 659        NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 660        NEW_AUX_ENT(AT_SECURE,  bprm->secureexec);
 661        NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
 662
 663#ifdef ARCH_DLINFO
 664        nr = 0;
 665        csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
 666
 667        /* ARCH_DLINFO must come last so platform specific code can enforce
 668         * special alignment requirements on the AUXV if necessary (eg. PPC).
 669         */
 670        ARCH_DLINFO;
 671#endif
 672#undef NEW_AUX_ENT
 673
 674        /* allocate room for argv[] and envv[] */
 675        csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 676        envp = (elf_caddr_t __user *) csp;
 677        csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 678        argv = (elf_caddr_t __user *) csp;
 679
 680        /* stack argc */
 681        csp -= sizeof(unsigned long);
 682        if (put_user(bprm->argc, (unsigned long __user *) csp))
 683                return -EFAULT;
 684
 685        BUG_ON(csp != sp);
 686
 687        /* fill in the argv[] array */
 688#ifdef CONFIG_MMU
 689        current->mm->arg_start = bprm->p;
 690#else
 691        current->mm->arg_start = current->mm->start_stack -
 692                (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 693#endif
 694
 695        p = (char __user *) current->mm->arg_start;
 696        for (loop = bprm->argc; loop > 0; loop--) {
 697                if (put_user((elf_caddr_t) p, argv++))
 698                        return -EFAULT;
 699                len = strnlen_user(p, MAX_ARG_STRLEN);
 700                if (!len || len > MAX_ARG_STRLEN)
 701                        return -EINVAL;
 702                p += len;
 703        }
 704        if (put_user(NULL, argv))
 705                return -EFAULT;
 706        current->mm->arg_end = (unsigned long) p;
 707
 708        /* fill in the envv[] array */
 709        current->mm->env_start = (unsigned long) p;
 710        for (loop = bprm->envc; loop > 0; loop--) {
 711                if (put_user((elf_caddr_t)(unsigned long) p, envp++))
 712                        return -EFAULT;
 713                len = strnlen_user(p, MAX_ARG_STRLEN);
 714                if (!len || len > MAX_ARG_STRLEN)
 715                        return -EINVAL;
 716                p += len;
 717        }
 718        if (put_user(NULL, envp))
 719                return -EFAULT;
 720        current->mm->env_end = (unsigned long) p;
 721
 722        mm->start_stack = (unsigned long) sp;
 723        return 0;
 724}
 725
 726/*****************************************************************************/
 727/*
 728 * load the appropriate binary image (executable or interpreter) into memory
 729 * - we assume no MMU is available
 730 * - if no other PIC bits are set in params->hdr->e_flags
 731 *   - we assume that the LOADable segments in the binary are independently relocatable
 732 *   - we assume R/O executable segments are shareable
 733 * - else
 734 *   - we assume the loadable parts of the image to require fixed displacement
 735 *   - the image is not shareable
 736 */
 737static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 738                              struct file *file,
 739                              struct mm_struct *mm,
 740                              const char *what)
 741{
 742        struct elf32_fdpic_loadmap *loadmap;
 743#ifdef CONFIG_MMU
 744        struct elf32_fdpic_loadseg *mseg;
 745#endif
 746        struct elf32_fdpic_loadseg *seg;
 747        struct elf32_phdr *phdr;
 748        unsigned long load_addr, stop;
 749        unsigned nloads, tmp;
 750        size_t size;
 751        int loop, ret;
 752
 753        /* allocate a load map table */
 754        nloads = 0;
 755        for (loop = 0; loop < params->hdr.e_phnum; loop++)
 756                if (params->phdrs[loop].p_type == PT_LOAD)
 757                        nloads++;
 758
 759        if (nloads == 0)
 760                return -ELIBBAD;
 761
 762        size = sizeof(*loadmap) + nloads * sizeof(*seg);
 763        loadmap = kzalloc(size, GFP_KERNEL);
 764        if (!loadmap)
 765                return -ENOMEM;
 766
 767        params->loadmap = loadmap;
 768
 769        loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
 770        loadmap->nsegs = nloads;
 771
 772        load_addr = params->load_addr;
 773        seg = loadmap->segs;
 774
 775        /* map the requested LOADs into the memory space */
 776        switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 777        case ELF_FDPIC_FLAG_CONSTDISP:
 778        case ELF_FDPIC_FLAG_CONTIGUOUS:
 779#ifndef CONFIG_MMU
 780                ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 781                if (ret < 0)
 782                        return ret;
 783                break;
 784#endif
 785        default:
 786                ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 787                if (ret < 0)
 788                        return ret;
 789                break;
 790        }
 791
 792        /* map the entry point */
 793        if (params->hdr.e_entry) {
 794                seg = loadmap->segs;
 795                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 796                        if (params->hdr.e_entry >= seg->p_vaddr &&
 797                            params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 798                                params->entry_addr =
 799                                        (params->hdr.e_entry - seg->p_vaddr) +
 800                                        seg->addr;
 801                                break;
 802                        }
 803                }
 804        }
 805
 806        /* determine where the program header table has wound up if mapped */
 807        stop = params->hdr.e_phoff;
 808        stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 809        phdr = params->phdrs;
 810
 811        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 812                if (phdr->p_type != PT_LOAD)
 813                        continue;
 814
 815                if (phdr->p_offset > params->hdr.e_phoff ||
 816                    phdr->p_offset + phdr->p_filesz < stop)
 817                        continue;
 818
 819                seg = loadmap->segs;
 820                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 821                        if (phdr->p_vaddr >= seg->p_vaddr &&
 822                            phdr->p_vaddr + phdr->p_filesz <=
 823                            seg->p_vaddr + seg->p_memsz) {
 824                                params->ph_addr =
 825                                        (phdr->p_vaddr - seg->p_vaddr) +
 826                                        seg->addr +
 827                                        params->hdr.e_phoff - phdr->p_offset;
 828                                break;
 829                        }
 830                }
 831                break;
 832        }
 833
 834        /* determine where the dynamic section has wound up if there is one */
 835        phdr = params->phdrs;
 836        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 837                if (phdr->p_type != PT_DYNAMIC)
 838                        continue;
 839
 840                seg = loadmap->segs;
 841                for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 842                        if (phdr->p_vaddr >= seg->p_vaddr &&
 843                            phdr->p_vaddr + phdr->p_memsz <=
 844                            seg->p_vaddr + seg->p_memsz) {
 845                                Elf32_Dyn __user *dyn;
 846                                Elf32_Sword d_tag;
 847
 848                                params->dynamic_addr =
 849                                        (phdr->p_vaddr - seg->p_vaddr) +
 850                                        seg->addr;
 851
 852                                /* check the dynamic section contains at least
 853                                 * one item, and that the last item is a NULL
 854                                 * entry */
 855                                if (phdr->p_memsz == 0 ||
 856                                    phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
 857                                        goto dynamic_error;
 858
 859                                tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
 860                                dyn = (Elf32_Dyn __user *)params->dynamic_addr;
 861                                if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
 862                                    d_tag != 0)
 863                                        goto dynamic_error;
 864                                break;
 865                        }
 866                }
 867                break;
 868        }
 869
 870        /* now elide adjacent segments in the load map on MMU linux
 871         * - on uClinux the holes between may actually be filled with system
 872         *   stuff or stuff from other processes
 873         */
 874#ifdef CONFIG_MMU
 875        nloads = loadmap->nsegs;
 876        mseg = loadmap->segs;
 877        seg = mseg + 1;
 878        for (loop = 1; loop < nloads; loop++) {
 879                /* see if we have a candidate for merging */
 880                if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 881                        load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 882                        if (load_addr == (seg->addr & PAGE_MASK)) {
 883                                mseg->p_memsz +=
 884                                        load_addr -
 885                                        (mseg->addr + mseg->p_memsz);
 886                                mseg->p_memsz += seg->addr & ~PAGE_MASK;
 887                                mseg->p_memsz += seg->p_memsz;
 888                                loadmap->nsegs--;
 889                                continue;
 890                        }
 891                }
 892
 893                mseg++;
 894                if (mseg != seg)
 895                        *mseg = *seg;
 896        }
 897#endif
 898
 899        kdebug("Mapped Object [%s]:", what);
 900        kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 901        kdebug("- entry    : %lx", params->entry_addr);
 902        kdebug("- PHDR[]   : %lx", params->ph_addr);
 903        kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 904        seg = loadmap->segs;
 905        for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 906                kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
 907                       loop,
 908                       seg->addr, seg->addr + seg->p_memsz - 1,
 909                       seg->p_vaddr, seg->p_memsz);
 910
 911        return 0;
 912
 913dynamic_error:
 914        printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 915               what, file_inode(file)->i_ino);
 916        return -ELIBBAD;
 917}
 918
 919/*****************************************************************************/
 920/*
 921 * map a file with constant displacement under uClinux
 922 */
 923#ifndef CONFIG_MMU
 924static int elf_fdpic_map_file_constdisp_on_uclinux(
 925        struct elf_fdpic_params *params,
 926        struct file *file,
 927        struct mm_struct *mm)
 928{
 929        struct elf32_fdpic_loadseg *seg;
 930        struct elf32_phdr *phdr;
 931        unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
 932        int loop, ret;
 933
 934        load_addr = params->load_addr;
 935        seg = params->loadmap->segs;
 936
 937        /* determine the bounds of the contiguous overall allocation we must
 938         * make */
 939        phdr = params->phdrs;
 940        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 941                if (params->phdrs[loop].p_type != PT_LOAD)
 942                        continue;
 943
 944                if (base > phdr->p_vaddr)
 945                        base = phdr->p_vaddr;
 946                if (top < phdr->p_vaddr + phdr->p_memsz)
 947                        top = phdr->p_vaddr + phdr->p_memsz;
 948        }
 949
 950        /* allocate one big anon block for everything */
 951        maddr = vm_mmap(NULL, load_addr, top - base,
 952                        PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
 953        if (IS_ERR_VALUE(maddr))
 954                return (int) maddr;
 955
 956        if (load_addr != 0)
 957                load_addr += PAGE_ALIGN(top - base);
 958
 959        /* and then load the file segments into it */
 960        phdr = params->phdrs;
 961        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 962                if (params->phdrs[loop].p_type != PT_LOAD)
 963                        continue;
 964
 965                seg->addr = maddr + (phdr->p_vaddr - base);
 966                seg->p_vaddr = phdr->p_vaddr;
 967                seg->p_memsz = phdr->p_memsz;
 968
 969                ret = read_code(file, seg->addr, phdr->p_offset,
 970                                       phdr->p_filesz);
 971                if (ret < 0)
 972                        return ret;
 973
 974                /* map the ELF header address if in this segment */
 975                if (phdr->p_offset == 0)
 976                        params->elfhdr_addr = seg->addr;
 977
 978                /* clear any space allocated but not loaded */
 979                if (phdr->p_filesz < phdr->p_memsz) {
 980                        if (clear_user((void *) (seg->addr + phdr->p_filesz),
 981                                       phdr->p_memsz - phdr->p_filesz))
 982                                return -EFAULT;
 983                }
 984
 985                if (mm) {
 986                        if (phdr->p_flags & PF_X) {
 987                                if (!mm->start_code) {
 988                                        mm->start_code = seg->addr;
 989                                        mm->end_code = seg->addr +
 990                                                phdr->p_memsz;
 991                                }
 992                        } else if (!mm->start_data) {
 993                                mm->start_data = seg->addr;
 994                                mm->end_data = seg->addr + phdr->p_memsz;
 995                        }
 996                }
 997
 998                seg++;
 999        }
1000
1001        return 0;
1002}
1003#endif
1004
1005/*****************************************************************************/
1006/*
1007 * map a binary by direct mmap() of the individual PT_LOAD segments
1008 */
1009static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1010                                             struct file *file,
1011                                             struct mm_struct *mm)
1012{
1013        struct elf32_fdpic_loadseg *seg;
1014        struct elf32_phdr *phdr;
1015        unsigned long load_addr, delta_vaddr;
1016        int loop, dvset;
1017
1018        load_addr = params->load_addr;
1019        delta_vaddr = 0;
1020        dvset = 0;
1021
1022        seg = params->loadmap->segs;
1023
1024        /* deal with each load segment separately */
1025        phdr = params->phdrs;
1026        for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1027                unsigned long maddr, disp, excess, excess1;
1028                int prot = 0, flags;
1029
1030                if (phdr->p_type != PT_LOAD)
1031                        continue;
1032
1033                kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1034                       (unsigned long) phdr->p_vaddr,
1035                       (unsigned long) phdr->p_offset,
1036                       (unsigned long) phdr->p_filesz,
1037                       (unsigned long) phdr->p_memsz);
1038
1039                /* determine the mapping parameters */
1040                if (phdr->p_flags & PF_R) prot |= PROT_READ;
1041                if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1042                if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1043
1044                flags = MAP_PRIVATE | MAP_DENYWRITE;
1045                maddr = 0;
1046
1047                switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1048                case ELF_FDPIC_FLAG_INDEPENDENT:
1049                        /* PT_LOADs are independently locatable */
1050                        break;
1051
1052                case ELF_FDPIC_FLAG_HONOURVADDR:
1053                        /* the specified virtual address must be honoured */
1054                        maddr = phdr->p_vaddr;
1055                        flags |= MAP_FIXED;
1056                        break;
1057
1058                case ELF_FDPIC_FLAG_CONSTDISP:
1059                        /* constant displacement
1060                         * - can be mapped anywhere, but must be mapped as a
1061                         *   unit
1062                         */
1063                        if (!dvset) {
1064                                maddr = load_addr;
1065                                delta_vaddr = phdr->p_vaddr;
1066                                dvset = 1;
1067                        } else {
1068                                maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1069                                flags |= MAP_FIXED;
1070                        }
1071                        break;
1072
1073                case ELF_FDPIC_FLAG_CONTIGUOUS:
1074                        /* contiguity handled later */
1075                        break;
1076
1077                default:
1078                        BUG();
1079                }
1080
1081                maddr &= PAGE_MASK;
1082
1083                /* create the mapping */
1084                disp = phdr->p_vaddr & ~PAGE_MASK;
1085                maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1086                                phdr->p_offset - disp);
1087
1088                kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1089                       loop, phdr->p_memsz + disp, prot, flags,
1090                       phdr->p_offset - disp, maddr);
1091
1092                if (IS_ERR_VALUE(maddr))
1093                        return (int) maddr;
1094
1095                if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1096                    ELF_FDPIC_FLAG_CONTIGUOUS)
1097                        load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1098
1099                seg->addr = maddr + disp;
1100                seg->p_vaddr = phdr->p_vaddr;
1101                seg->p_memsz = phdr->p_memsz;
1102
1103                /* map the ELF header address if in this segment */
1104                if (phdr->p_offset == 0)
1105                        params->elfhdr_addr = seg->addr;
1106
1107                /* clear the bit between beginning of mapping and beginning of
1108                 * PT_LOAD */
1109                if (prot & PROT_WRITE && disp > 0) {
1110                        kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1111                        if (clear_user((void __user *) maddr, disp))
1112                                return -EFAULT;
1113                        maddr += disp;
1114                }
1115
1116                /* clear any space allocated but not loaded
1117                 * - on uClinux we can just clear the lot
1118                 * - on MMU linux we'll get a SIGBUS beyond the last page
1119                 *   extant in the file
1120                 */
1121                excess = phdr->p_memsz - phdr->p_filesz;
1122                excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1123
1124#ifdef CONFIG_MMU
1125                if (excess > excess1) {
1126                        unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1127                        unsigned long xmaddr;
1128
1129                        flags |= MAP_FIXED | MAP_ANONYMOUS;
1130                        xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1131                                         prot, flags, 0);
1132
1133                        kdebug("mmap[%d] <anon>"
1134                               " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1135                               loop, xaddr, excess - excess1, prot, flags,
1136                               xmaddr);
1137
1138                        if (xmaddr != xaddr)
1139                                return -ENOMEM;
1140                }
1141
1142                if (prot & PROT_WRITE && excess1 > 0) {
1143                        kdebug("clear[%d] ad=%lx sz=%lx",
1144                               loop, maddr + phdr->p_filesz, excess1);
1145                        if (clear_user((void __user *) maddr + phdr->p_filesz,
1146                                       excess1))
1147                                return -EFAULT;
1148                }
1149
1150#else
1151                if (excess > 0) {
1152                        kdebug("clear[%d] ad=%lx sz=%lx",
1153                               loop, maddr + phdr->p_filesz, excess);
1154                        if (clear_user((void *) maddr + phdr->p_filesz, excess))
1155                                return -EFAULT;
1156                }
1157#endif
1158
1159                if (mm) {
1160                        if (phdr->p_flags & PF_X) {
1161                                if (!mm->start_code) {
1162                                        mm->start_code = maddr;
1163                                        mm->end_code = maddr + phdr->p_memsz;
1164                                }
1165                        } else if (!mm->start_data) {
1166                                mm->start_data = maddr;
1167                                mm->end_data = maddr + phdr->p_memsz;
1168                        }
1169                }
1170
1171                seg++;
1172        }
1173
1174        return 0;
1175}
1176
1177/*****************************************************************************/
1178/*
1179 * ELF-FDPIC core dumper
1180 *
1181 * Modelled on fs/exec.c:aout_core_dump()
1182 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1183 *
1184 * Modelled on fs/binfmt_elf.c core dumper
1185 */
1186#ifdef CONFIG_ELF_CORE
1187
1188struct elf_prstatus_fdpic
1189{
1190        struct elf_prstatus_common      common;
1191        elf_gregset_t pr_reg;   /* GP registers */
1192        /* When using FDPIC, the loadmap addresses need to be communicated
1193         * to GDB in order for GDB to do the necessary relocations.  The
1194         * fields (below) used to communicate this information are placed
1195         * immediately after ``pr_reg'', so that the loadmap addresses may
1196         * be viewed as part of the register set if so desired.
1197         */
1198        unsigned long pr_exec_fdpic_loadmap;
1199        unsigned long pr_interp_fdpic_loadmap;
1200        int pr_fpvalid;         /* True if math co-processor being used.  */
1201};
1202
1203/* An ELF note in memory */
1204struct memelfnote
1205{
1206        const char *name;
1207        int type;
1208        unsigned int datasz;
1209        void *data;
1210};
1211
1212static int notesize(struct memelfnote *en)
1213{
1214        int sz;
1215
1216        sz = sizeof(struct elf_note);
1217        sz += roundup(strlen(en->name) + 1, 4);
1218        sz += roundup(en->datasz, 4);
1219
1220        return sz;
1221}
1222
1223/* #define DEBUG */
1224
1225static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1226{
1227        struct elf_note en;
1228        en.n_namesz = strlen(men->name) + 1;
1229        en.n_descsz = men->datasz;
1230        en.n_type = men->type;
1231
1232        return dump_emit(cprm, &en, sizeof(en)) &&
1233                dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1234                dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1235}
1236
1237static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1238{
1239        memcpy(elf->e_ident, ELFMAG, SELFMAG);
1240        elf->e_ident[EI_CLASS] = ELF_CLASS;
1241        elf->e_ident[EI_DATA] = ELF_DATA;
1242        elf->e_ident[EI_VERSION] = EV_CURRENT;
1243        elf->e_ident[EI_OSABI] = ELF_OSABI;
1244        memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1245
1246        elf->e_type = ET_CORE;
1247        elf->e_machine = ELF_ARCH;
1248        elf->e_version = EV_CURRENT;
1249        elf->e_entry = 0;
1250        elf->e_phoff = sizeof(struct elfhdr);
1251        elf->e_shoff = 0;
1252        elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1253        elf->e_ehsize = sizeof(struct elfhdr);
1254        elf->e_phentsize = sizeof(struct elf_phdr);
1255        elf->e_phnum = segs;
1256        elf->e_shentsize = 0;
1257        elf->e_shnum = 0;
1258        elf->e_shstrndx = 0;
1259        return;
1260}
1261
1262static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1263{
1264        phdr->p_type = PT_NOTE;
1265        phdr->p_offset = offset;
1266        phdr->p_vaddr = 0;
1267        phdr->p_paddr = 0;
1268        phdr->p_filesz = sz;
1269        phdr->p_memsz = 0;
1270        phdr->p_flags = 0;
1271        phdr->p_align = 0;
1272        return;
1273}
1274
1275static inline void fill_note(struct memelfnote *note, const char *name, int type,
1276                unsigned int sz, void *data)
1277{
1278        note->name = name;
1279        note->type = type;
1280        note->datasz = sz;
1281        note->data = data;
1282        return;
1283}
1284
1285/*
1286 * fill up all the fields in prstatus from the given task struct, except
1287 * registers which need to be filled up separately.
1288 */
1289static void fill_prstatus(struct elf_prstatus_common *prstatus,
1290                          struct task_struct *p, long signr)
1291{
1292        prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1293        prstatus->pr_sigpend = p->pending.signal.sig[0];
1294        prstatus->pr_sighold = p->blocked.sig[0];
1295        rcu_read_lock();
1296        prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1297        rcu_read_unlock();
1298        prstatus->pr_pid = task_pid_vnr(p);
1299        prstatus->pr_pgrp = task_pgrp_vnr(p);
1300        prstatus->pr_sid = task_session_vnr(p);
1301        if (thread_group_leader(p)) {
1302                struct task_cputime cputime;
1303
1304                /*
1305                 * This is the record for the group leader.  It shows the
1306                 * group-wide total, not its individual thread total.
1307                 */
1308                thread_group_cputime(p, &cputime);
1309                prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1310                prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1311        } else {
1312                u64 utime, stime;
1313
1314                task_cputime(p, &utime, &stime);
1315                prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1316                prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1317        }
1318        prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1319        prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1320}
1321
1322static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1323                       struct mm_struct *mm)
1324{
1325        const struct cred *cred;
1326        unsigned int i, len;
1327        unsigned int state;
1328
1329        /* first copy the parameters from user space */
1330        memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1331
1332        len = mm->arg_end - mm->arg_start;
1333        if (len >= ELF_PRARGSZ)
1334                len = ELF_PRARGSZ - 1;
1335        if (copy_from_user(&psinfo->pr_psargs,
1336                           (const char __user *) mm->arg_start, len))
1337                return -EFAULT;
1338        for (i = 0; i < len; i++)
1339                if (psinfo->pr_psargs[i] == 0)
1340                        psinfo->pr_psargs[i] = ' ';
1341        psinfo->pr_psargs[len] = 0;
1342
1343        rcu_read_lock();
1344        psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1345        rcu_read_unlock();
1346        psinfo->pr_pid = task_pid_vnr(p);
1347        psinfo->pr_pgrp = task_pgrp_vnr(p);
1348        psinfo->pr_sid = task_session_vnr(p);
1349
1350        state = READ_ONCE(p->__state);
1351        i = state ? ffz(~state) + 1 : 0;
1352        psinfo->pr_state = i;
1353        psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1354        psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1355        psinfo->pr_nice = task_nice(p);
1356        psinfo->pr_flag = p->flags;
1357        rcu_read_lock();
1358        cred = __task_cred(p);
1359        SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1360        SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1361        rcu_read_unlock();
1362        strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1363
1364        return 0;
1365}
1366
1367/* Here is the structure in which status of each thread is captured. */
1368struct elf_thread_status
1369{
1370        struct elf_thread_status *next;
1371        struct elf_prstatus_fdpic prstatus;     /* NT_PRSTATUS */
1372        elf_fpregset_t fpu;             /* NT_PRFPREG */
1373        struct memelfnote notes[2];
1374        int num_notes;
1375};
1376
1377/*
1378 * In order to add the specific thread information for the elf file format,
1379 * we need to keep a linked list of every thread's pr_status and then create
1380 * a single section for them in the final core file.
1381 */
1382static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1383{
1384        const struct user_regset_view *view = task_user_regset_view(p);
1385        struct elf_thread_status *t;
1386        int i, ret;
1387
1388        t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1389        if (!t)
1390                return t;
1391
1392        fill_prstatus(&t->prstatus.common, p, signr);
1393        t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1394        t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1395        regset_get(p, &view->regsets[0],
1396                   sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1397
1398        fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1399                  &t->prstatus);
1400        t->num_notes++;
1401        *sz += notesize(&t->notes[0]);
1402
1403        for (i = 1; i < view->n; ++i) {
1404                const struct user_regset *regset = &view->regsets[i];
1405                if (regset->core_note_type != NT_PRFPREG)
1406                        continue;
1407                if (regset->active && regset->active(p, regset) <= 0)
1408                        continue;
1409                ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1410                if (ret >= 0)
1411                        t->prstatus.pr_fpvalid = 1;
1412                break;
1413        }
1414
1415        if (t->prstatus.pr_fpvalid) {
1416                fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1417                          &t->fpu);
1418                t->num_notes++;
1419                *sz += notesize(&t->notes[1]);
1420        }
1421        return t;
1422}
1423
1424static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1425                             elf_addr_t e_shoff, int segs)
1426{
1427        elf->e_shoff = e_shoff;
1428        elf->e_shentsize = sizeof(*shdr4extnum);
1429        elf->e_shnum = 1;
1430        elf->e_shstrndx = SHN_UNDEF;
1431
1432        memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1433
1434        shdr4extnum->sh_type = SHT_NULL;
1435        shdr4extnum->sh_size = elf->e_shnum;
1436        shdr4extnum->sh_link = elf->e_shstrndx;
1437        shdr4extnum->sh_info = segs;
1438}
1439
1440/*
1441 * dump the segments for an MMU process
1442 */
1443static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1444                                    struct core_vma_metadata *vma_meta,
1445                                    int vma_count)
1446{
1447        int i;
1448
1449        for (i = 0; i < vma_count; i++) {
1450                struct core_vma_metadata *meta = vma_meta + i;
1451
1452                if (!dump_user_range(cprm, meta->start, meta->dump_size))
1453                        return false;
1454        }
1455        return true;
1456}
1457
1458/*
1459 * Actual dumper
1460 *
1461 * This is a two-pass process; first we find the offsets of the bits,
1462 * and then they are actually written out.  If we run out of core limit
1463 * we just truncate.
1464 */
1465static int elf_fdpic_core_dump(struct coredump_params *cprm)
1466{
1467        int has_dumped = 0;
1468        int vma_count, segs;
1469        int i;
1470        struct elfhdr *elf = NULL;
1471        loff_t offset = 0, dataoff;
1472        struct memelfnote psinfo_note, auxv_note;
1473        struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1474        struct elf_thread_status *thread_list = NULL;
1475        int thread_status_size = 0;
1476        elf_addr_t *auxv;
1477        struct elf_phdr *phdr4note = NULL;
1478        struct elf_shdr *shdr4extnum = NULL;
1479        Elf_Half e_phnum;
1480        elf_addr_t e_shoff;
1481        struct core_thread *ct;
1482        struct elf_thread_status *tmp;
1483        struct core_vma_metadata *vma_meta = NULL;
1484        size_t vma_data_size;
1485
1486        /* alloc memory for large data structures: too large to be on stack */
1487        elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1488        if (!elf)
1489                goto end_coredump;
1490        psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1491        if (!psinfo)
1492                goto end_coredump;
1493
1494        if (dump_vma_snapshot(cprm, &vma_count, &vma_meta, &vma_data_size))
1495                goto end_coredump;
1496
1497        for (ct = current->mm->core_state->dumper.next;
1498                                        ct; ct = ct->next) {
1499                tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1500                                             ct->task, &thread_status_size);
1501                if (!tmp)
1502                        goto end_coredump;
1503
1504                tmp->next = thread_list;
1505                thread_list = tmp;
1506        }
1507
1508        /* now collect the dump for the current */
1509        tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1510                                     current, &thread_status_size);
1511        if (!tmp)
1512                goto end_coredump;
1513        tmp->next = thread_list;
1514        thread_list = tmp;
1515
1516        segs = vma_count + elf_core_extra_phdrs();
1517
1518        /* for notes section */
1519        segs++;
1520
1521        /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1522         * this, kernel supports extended numbering. Have a look at
1523         * include/linux/elf.h for further information. */
1524        e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1525
1526        /* Set up header */
1527        fill_elf_fdpic_header(elf, e_phnum);
1528
1529        has_dumped = 1;
1530        /*
1531         * Set up the notes in similar form to SVR4 core dumps made
1532         * with info from their /proc.
1533         */
1534
1535        fill_psinfo(psinfo, current->group_leader, current->mm);
1536        fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1537        thread_status_size += notesize(&psinfo_note);
1538
1539        auxv = (elf_addr_t *) current->mm->saved_auxv;
1540        i = 0;
1541        do
1542                i += 2;
1543        while (auxv[i - 2] != AT_NULL);
1544        fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1545        thread_status_size += notesize(&auxv_note);
1546
1547        offset = sizeof(*elf);                          /* Elf header */
1548        offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1549
1550        /* Write notes phdr entry */
1551        phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1552        if (!phdr4note)
1553                goto end_coredump;
1554
1555        fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1556        offset += thread_status_size;
1557
1558        /* Page-align dumped data */
1559        dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1560
1561        offset += vma_data_size;
1562        offset += elf_core_extra_data_size();
1563        e_shoff = offset;
1564
1565        if (e_phnum == PN_XNUM) {
1566                shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1567                if (!shdr4extnum)
1568                        goto end_coredump;
1569                fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1570        }
1571
1572        offset = dataoff;
1573
1574        if (!dump_emit(cprm, elf, sizeof(*elf)))
1575                goto end_coredump;
1576
1577        if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1578                goto end_coredump;
1579
1580        /* write program headers for segments dump */
1581        for (i = 0; i < vma_count; i++) {
1582                struct core_vma_metadata *meta = vma_meta + i;
1583                struct elf_phdr phdr;
1584                size_t sz;
1585
1586                sz = meta->end - meta->start;
1587
1588                phdr.p_type = PT_LOAD;
1589                phdr.p_offset = offset;
1590                phdr.p_vaddr = meta->start;
1591                phdr.p_paddr = 0;
1592                phdr.p_filesz = meta->dump_size;
1593                phdr.p_memsz = sz;
1594                offset += phdr.p_filesz;
1595                phdr.p_flags = 0;
1596                if (meta->flags & VM_READ)
1597                        phdr.p_flags |= PF_R;
1598                if (meta->flags & VM_WRITE)
1599                        phdr.p_flags |= PF_W;
1600                if (meta->flags & VM_EXEC)
1601                        phdr.p_flags |= PF_X;
1602                phdr.p_align = ELF_EXEC_PAGESIZE;
1603
1604                if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1605                        goto end_coredump;
1606        }
1607
1608        if (!elf_core_write_extra_phdrs(cprm, offset))
1609                goto end_coredump;
1610
1611        /* write out the notes section */
1612        if (!writenote(thread_list->notes, cprm))
1613                goto end_coredump;
1614        if (!writenote(&psinfo_note, cprm))
1615                goto end_coredump;
1616        if (!writenote(&auxv_note, cprm))
1617                goto end_coredump;
1618        for (i = 1; i < thread_list->num_notes; i++)
1619                if (!writenote(thread_list->notes + i, cprm))
1620                        goto end_coredump;
1621
1622        /* write out the thread status notes section */
1623        for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1624                for (i = 0; i < tmp->num_notes; i++)
1625                        if (!writenote(&tmp->notes[i], cprm))
1626                                goto end_coredump;
1627        }
1628
1629        dump_skip_to(cprm, dataoff);
1630
1631        if (!elf_fdpic_dump_segments(cprm, vma_meta, vma_count))
1632                goto end_coredump;
1633
1634        if (!elf_core_write_extra_data(cprm))
1635                goto end_coredump;
1636
1637        if (e_phnum == PN_XNUM) {
1638                if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1639                        goto end_coredump;
1640        }
1641
1642        if (cprm->file->f_pos != offset) {
1643                /* Sanity check */
1644                printk(KERN_WARNING
1645                       "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1646                       cprm->file->f_pos, offset);
1647        }
1648
1649end_coredump:
1650        while (thread_list) {
1651                tmp = thread_list;
1652                thread_list = thread_list->next;
1653                kfree(tmp);
1654        }
1655        kvfree(vma_meta);
1656        kfree(phdr4note);
1657        kfree(elf);
1658        kfree(psinfo);
1659        kfree(shdr4extnum);
1660        return has_dumped;
1661}
1662
1663#endif          /* CONFIG_ELF_CORE */
1664
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