linux/fs/binfmt_flat.c
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   1/****************************************************************************/
   2/*
   3 *  linux/fs/binfmt_flat.c
   4 *
   5 *      Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
   6 *      Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
   7 *      Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
   8 *      Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
   9 *  based heavily on:
  10 *
  11 *  linux/fs/binfmt_aout.c:
  12 *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
  13 *  linux/fs/binfmt_flat.c for 2.0 kernel
  14 *          Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
  15 *      JAN/99 -- coded full program relocation (gerg@snapgear.com)
  16 */
  17
  18#include <linux/module.h>
  19#include <linux/kernel.h>
  20#include <linux/sched.h>
  21#include <linux/mm.h>
  22#include <linux/mman.h>
  23#include <linux/errno.h>
  24#include <linux/signal.h>
  25#include <linux/string.h>
  26#include <linux/fs.h>
  27#include <linux/file.h>
  28#include <linux/stat.h>
  29#include <linux/fcntl.h>
  30#include <linux/ptrace.h>
  31#include <linux/user.h>
  32#include <linux/slab.h>
  33#include <linux/binfmts.h>
  34#include <linux/personality.h>
  35#include <linux/init.h>
  36#include <linux/flat.h>
  37#include <linux/syscalls.h>
  38
  39#include <asm/byteorder.h>
  40#include <asm/system.h>
  41#include <asm/uaccess.h>
  42#include <asm/unaligned.h>
  43#include <asm/cacheflush.h>
  44#include <asm/page.h>
  45
  46/****************************************************************************/
  47
  48#if 0
  49#define DEBUG 1
  50#endif
  51
  52#ifdef DEBUG
  53#define DBG_FLT(a...)   printk(a)
  54#else
  55#define DBG_FLT(a...)
  56#endif
  57
  58/*
  59 * User data (data section and bss) needs to be aligned.
  60 * We pick 0x20 here because it is the max value elf2flt has always
  61 * used in producing FLAT files, and because it seems to be large
  62 * enough to make all the gcc alignment related tests happy.
  63 */
  64#define FLAT_DATA_ALIGN (0x20)
  65
  66/*
  67 * User data (stack) also needs to be aligned.
  68 * Here we can be a bit looser than the data sections since this
  69 * needs to only meet arch ABI requirements.
  70 */
  71#define FLAT_STACK_ALIGN        max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
  72
  73#define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  74#define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  75
  76struct lib_info {
  77        struct {
  78                unsigned long start_code;               /* Start of text segment */
  79                unsigned long start_data;               /* Start of data segment */
  80                unsigned long start_brk;                /* End of data segment */
  81                unsigned long text_len;                 /* Length of text segment */
  82                unsigned long entry;                    /* Start address for this module */
  83                unsigned long build_date;               /* When this one was compiled */
  84                short loaded;                           /* Has this library been loaded? */
  85        } lib_list[MAX_SHARED_LIBS];
  86};
  87
  88#ifdef CONFIG_BINFMT_SHARED_FLAT
  89static int load_flat_shared_library(int id, struct lib_info *p);
  90#endif
  91
  92static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
  93static int flat_core_dump(struct coredump_params *cprm);
  94
  95static struct linux_binfmt flat_format = {
  96        .module         = THIS_MODULE,
  97        .load_binary    = load_flat_binary,
  98        .core_dump      = flat_core_dump,
  99        .min_coredump   = PAGE_SIZE
 100};
 101
 102/****************************************************************************/
 103/*
 104 * Routine writes a core dump image in the current directory.
 105 * Currently only a stub-function.
 106 */
 107
 108static int flat_core_dump(struct coredump_params *cprm)
 109{
 110        printk("Process %s:%d received signr %d and should have core dumped\n",
 111                        current->comm, current->pid, (int) cprm->signr);
 112        return(1);
 113}
 114
 115/****************************************************************************/
 116/*
 117 * create_flat_tables() parses the env- and arg-strings in new user
 118 * memory and creates the pointer tables from them, and puts their
 119 * addresses on the "stack", returning the new stack pointer value.
 120 */
 121
 122static unsigned long create_flat_tables(
 123        unsigned long pp,
 124        struct linux_binprm * bprm)
 125{
 126        unsigned long *argv,*envp;
 127        unsigned long * sp;
 128        char * p = (char*)pp;
 129        int argc = bprm->argc;
 130        int envc = bprm->envc;
 131        char uninitialized_var(dummy);
 132
 133        sp = (unsigned long *)p;
 134        sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
 135        sp = (unsigned long *) ((unsigned long)sp & -FLAT_STACK_ALIGN);
 136        argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
 137        envp = argv + (argc + 1);
 138
 139        if (flat_argvp_envp_on_stack()) {
 140                put_user((unsigned long) envp, sp + 2);
 141                put_user((unsigned long) argv, sp + 1);
 142        }
 143
 144        put_user(argc, sp);
 145        current->mm->arg_start = (unsigned long) p;
 146        while (argc-->0) {
 147                put_user((unsigned long) p, argv++);
 148                do {
 149                        get_user(dummy, p); p++;
 150                } while (dummy);
 151        }
 152        put_user((unsigned long) NULL, argv);
 153        current->mm->arg_end = current->mm->env_start = (unsigned long) p;
 154        while (envc-->0) {
 155                put_user((unsigned long)p, envp); envp++;
 156                do {
 157                        get_user(dummy, p); p++;
 158                } while (dummy);
 159        }
 160        put_user((unsigned long) NULL, envp);
 161        current->mm->env_end = (unsigned long) p;
 162        return (unsigned long)sp;
 163}
 164
 165/****************************************************************************/
 166
 167#ifdef CONFIG_BINFMT_ZFLAT
 168
 169#include <linux/zlib.h>
 170
 171#define LBUFSIZE        4000
 172
 173/* gzip flag byte */
 174#define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 175#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 176#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 177#define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 178#define COMMENT      0x10 /* bit 4 set: file comment present */
 179#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 180#define RESERVED     0xC0 /* bit 6,7:   reserved */
 181
 182static int decompress_exec(
 183        struct linux_binprm *bprm,
 184        unsigned long offset,
 185        char *dst,
 186        long len,
 187        int fd)
 188{
 189        unsigned char *buf;
 190        z_stream strm;
 191        loff_t fpos;
 192        int ret, retval;
 193
 194        DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
 195
 196        memset(&strm, 0, sizeof(strm));
 197        strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 198        if (strm.workspace == NULL) {
 199                DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
 200                return -ENOMEM;
 201        }
 202        buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 203        if (buf == NULL) {
 204                DBG_FLT("binfmt_flat: no memory for read buffer\n");
 205                retval = -ENOMEM;
 206                goto out_free;
 207        }
 208
 209        /* Read in first chunk of data and parse gzip header. */
 210        fpos = offset;
 211        ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 212
 213        strm.next_in = buf;
 214        strm.avail_in = ret;
 215        strm.total_in = 0;
 216
 217        retval = -ENOEXEC;
 218
 219        /* Check minimum size -- gzip header */
 220        if (ret < 10) {
 221                DBG_FLT("binfmt_flat: file too small?\n");
 222                goto out_free_buf;
 223        }
 224
 225        /* Check gzip magic number */
 226        if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 227                DBG_FLT("binfmt_flat: unknown compression magic?\n");
 228                goto out_free_buf;
 229        }
 230
 231        /* Check gzip method */
 232        if (buf[2] != 8) {
 233                DBG_FLT("binfmt_flat: unknown compression method?\n");
 234                goto out_free_buf;
 235        }
 236        /* Check gzip flags */
 237        if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 238            (buf[3] & RESERVED)) {
 239                DBG_FLT("binfmt_flat: unknown flags?\n");
 240                goto out_free_buf;
 241        }
 242
 243        ret = 10;
 244        if (buf[3] & EXTRA_FIELD) {
 245                ret += 2 + buf[10] + (buf[11] << 8);
 246                if (unlikely(LBUFSIZE <= ret)) {
 247                        DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
 248                        goto out_free_buf;
 249                }
 250        }
 251        if (buf[3] & ORIG_NAME) {
 252                while (ret < LBUFSIZE && buf[ret++] != 0)
 253                        ;
 254                if (unlikely(LBUFSIZE == ret)) {
 255                        DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
 256                        goto out_free_buf;
 257                }
 258        }
 259        if (buf[3] & COMMENT) {
 260                while (ret < LBUFSIZE && buf[ret++] != 0)
 261                        ;
 262                if (unlikely(LBUFSIZE == ret)) {
 263                        DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
 264                        goto out_free_buf;
 265                }
 266        }
 267
 268        strm.next_in += ret;
 269        strm.avail_in -= ret;
 270
 271        strm.next_out = dst;
 272        strm.avail_out = len;
 273        strm.total_out = 0;
 274
 275        if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 276                DBG_FLT("binfmt_flat: zlib init failed?\n");
 277                goto out_free_buf;
 278        }
 279
 280        while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 281                ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 282                if (ret <= 0)
 283                        break;
 284                len -= ret;
 285
 286                strm.next_in = buf;
 287                strm.avail_in = ret;
 288                strm.total_in = 0;
 289        }
 290
 291        if (ret < 0) {
 292                DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
 293                        ret, strm.msg);
 294                goto out_zlib;
 295        }
 296
 297        retval = 0;
 298out_zlib:
 299        zlib_inflateEnd(&strm);
 300out_free_buf:
 301        kfree(buf);
 302out_free:
 303        kfree(strm.workspace);
 304        return retval;
 305}
 306
 307#endif /* CONFIG_BINFMT_ZFLAT */
 308
 309/****************************************************************************/
 310
 311static unsigned long
 312calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 313{
 314        unsigned long addr;
 315        int id;
 316        unsigned long start_brk;
 317        unsigned long start_data;
 318        unsigned long text_len;
 319        unsigned long start_code;
 320
 321#ifdef CONFIG_BINFMT_SHARED_FLAT
 322        if (r == 0)
 323                id = curid;     /* Relocs of 0 are always self referring */
 324        else {
 325                id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 326                r &= 0x00ffffff;        /* Trim ID off here */
 327        }
 328        if (id >= MAX_SHARED_LIBS) {
 329                printk("BINFMT_FLAT: reference 0x%x to shared library %d",
 330                                (unsigned) r, id);
 331                goto failed;
 332        }
 333        if (curid != id) {
 334                if (internalp) {
 335                        printk("BINFMT_FLAT: reloc address 0x%x not in same module "
 336                                        "(%d != %d)", (unsigned) r, curid, id);
 337                        goto failed;
 338                } else if ( ! p->lib_list[id].loaded &&
 339                                IS_ERR_VALUE(load_flat_shared_library(id, p))) {
 340                        printk("BINFMT_FLAT: failed to load library %d", id);
 341                        goto failed;
 342                }
 343                /* Check versioning information (i.e. time stamps) */
 344                if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
 345                                p->lib_list[curid].build_date < p->lib_list[id].build_date) {
 346                        printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
 347                        goto failed;
 348                }
 349        }
 350#else
 351        id = 0;
 352#endif
 353
 354        start_brk = p->lib_list[id].start_brk;
 355        start_data = p->lib_list[id].start_data;
 356        start_code = p->lib_list[id].start_code;
 357        text_len = p->lib_list[id].text_len;
 358
 359        if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
 360                printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
 361                       (int) r,(int)(start_brk-start_data+text_len),(int)text_len);
 362                goto failed;
 363        }
 364
 365        if (r < text_len)                       /* In text segment */
 366                addr = r + start_code;
 367        else                                    /* In data segment */
 368                addr = r - text_len + start_data;
 369
 370        /* Range checked already above so doing the range tests is redundant...*/
 371        return(addr);
 372
 373failed:
 374        printk(", killing %s!\n", current->comm);
 375        send_sig(SIGSEGV, current, 0);
 376
 377        return RELOC_FAILED;
 378}
 379
 380/****************************************************************************/
 381
 382void old_reloc(unsigned long rl)
 383{
 384#ifdef DEBUG
 385        char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 386#endif
 387        flat_v2_reloc_t r;
 388        unsigned long *ptr;
 389        
 390        r.value = rl;
 391#if defined(CONFIG_COLDFIRE)
 392        ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
 393#else
 394        ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
 395#endif
 396
 397#ifdef DEBUG
 398        printk("Relocation of variable at DATASEG+%x "
 399                "(address %p, currently %x) into segment %s\n",
 400                r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
 401#endif
 402        
 403        switch (r.reloc.type) {
 404        case OLD_FLAT_RELOC_TYPE_TEXT:
 405                *ptr += current->mm->start_code;
 406                break;
 407        case OLD_FLAT_RELOC_TYPE_DATA:
 408                *ptr += current->mm->start_data;
 409                break;
 410        case OLD_FLAT_RELOC_TYPE_BSS:
 411                *ptr += current->mm->end_data;
 412                break;
 413        default:
 414                printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
 415                break;
 416        }
 417
 418#ifdef DEBUG
 419        printk("Relocation became %x\n", (int)*ptr);
 420#endif
 421}               
 422
 423/****************************************************************************/
 424
 425static int load_flat_file(struct linux_binprm * bprm,
 426                struct lib_info *libinfo, int id, unsigned long *extra_stack)
 427{
 428        struct flat_hdr * hdr;
 429        unsigned long textpos = 0, datapos = 0, result;
 430        unsigned long realdatastart = 0;
 431        unsigned long text_len, data_len, bss_len, stack_len, flags;
 432        unsigned long len, memp = 0;
 433        unsigned long memp_size, extra, rlim;
 434        unsigned long *reloc = 0, *rp;
 435        struct inode *inode;
 436        int i, rev, relocs = 0;
 437        loff_t fpos;
 438        unsigned long start_code, end_code;
 439        int ret;
 440
 441        hdr = ((struct flat_hdr *) bprm->buf);          /* exec-header */
 442        inode = bprm->file->f_path.dentry->d_inode;
 443
 444        text_len  = ntohl(hdr->data_start);
 445        data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 446        bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 447        stack_len = ntohl(hdr->stack_size);
 448        if (extra_stack) {
 449                stack_len += *extra_stack;
 450                *extra_stack = stack_len;
 451        }
 452        relocs    = ntohl(hdr->reloc_count);
 453        flags     = ntohl(hdr->flags);
 454        rev       = ntohl(hdr->rev);
 455
 456        if (strncmp(hdr->magic, "bFLT", 4)) {
 457                /*
 458                 * Previously, here was a printk to tell people
 459                 *   "BINFMT_FLAT: bad header magic".
 460                 * But for the kernel which also use ELF FD-PIC format, this
 461                 * error message is confusing.
 462                 * because a lot of people do not manage to produce good
 463                 */
 464                ret = -ENOEXEC;
 465                goto err;
 466        }
 467
 468        if (flags & FLAT_FLAG_KTRACE)
 469                printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
 470
 471        if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 472                printk("BINFMT_FLAT: bad flat file version 0x%x (supported "
 473                        "0x%lx and 0x%lx)\n",
 474                        rev, FLAT_VERSION, OLD_FLAT_VERSION);
 475                ret = -ENOEXEC;
 476                goto err;
 477        }
 478        
 479        /* Don't allow old format executables to use shared libraries */
 480        if (rev == OLD_FLAT_VERSION && id != 0) {
 481                printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
 482                                (int) FLAT_VERSION);
 483                ret = -ENOEXEC;
 484                goto err;
 485        }
 486
 487        /*
 488         * fix up the flags for the older format,  there were all kinds
 489         * of endian hacks,  this only works for the simple cases
 490         */
 491        if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 492                flags = FLAT_FLAG_RAM;
 493
 494#ifndef CONFIG_BINFMT_ZFLAT
 495        if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 496                printk("Support for ZFLAT executables is not enabled.\n");
 497                ret = -ENOEXEC;
 498                goto err;
 499        }
 500#endif
 501
 502        /*
 503         * Check initial limits. This avoids letting people circumvent
 504         * size limits imposed on them by creating programs with large
 505         * arrays in the data or bss.
 506         */
 507        rlim = rlimit(RLIMIT_DATA);
 508        if (rlim >= RLIM_INFINITY)
 509                rlim = ~0;
 510        if (data_len + bss_len > rlim) {
 511                ret = -ENOMEM;
 512                goto err;
 513        }
 514
 515        /* Flush all traces of the currently running executable */
 516        if (id == 0) {
 517                result = flush_old_exec(bprm);
 518                if (result) {
 519                        ret = result;
 520                        goto err;
 521                }
 522
 523                /* OK, This is the point of no return */
 524                set_personality(PER_LINUX_32BIT);
 525                setup_new_exec(bprm);
 526        }
 527
 528        /*
 529         * calculate the extra space we need to map in
 530         */
 531        extra = max_t(unsigned long, bss_len + stack_len,
 532                        relocs * sizeof(unsigned long));
 533
 534        /*
 535         * there are a couple of cases here,  the separate code/data
 536         * case,  and then the fully copied to RAM case which lumps
 537         * it all together.
 538         */
 539        if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
 540                /*
 541                 * this should give us a ROM ptr,  but if it doesn't we don't
 542                 * really care
 543                 */
 544                DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
 545
 546                down_write(&current->mm->mmap_sem);
 547                textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
 548                                  MAP_PRIVATE|MAP_EXECUTABLE, 0);
 549                up_write(&current->mm->mmap_sem);
 550                if (!textpos || IS_ERR_VALUE(textpos)) {
 551                        if (!textpos)
 552                                textpos = (unsigned long) -ENOMEM;
 553                        printk("Unable to mmap process text, errno %d\n", (int)-textpos);
 554                        ret = textpos;
 555                        goto err;
 556                }
 557
 558                len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
 559                len = PAGE_ALIGN(len);
 560                down_write(&current->mm->mmap_sem);
 561                realdatastart = do_mmap(0, 0, len,
 562                        PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
 563                up_write(&current->mm->mmap_sem);
 564
 565                if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
 566                        if (!realdatastart)
 567                                realdatastart = (unsigned long) -ENOMEM;
 568                        printk("Unable to allocate RAM for process data, errno %d\n",
 569                                        (int)-realdatastart);
 570                        do_munmap(current->mm, textpos, text_len);
 571                        ret = realdatastart;
 572                        goto err;
 573                }
 574                datapos = ALIGN(realdatastart +
 575                                MAX_SHARED_LIBS * sizeof(unsigned long),
 576                                FLAT_DATA_ALIGN);
 577
 578                DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
 579                                (int)(data_len + bss_len + stack_len), (int)datapos);
 580
 581                fpos = ntohl(hdr->data_start);
 582#ifdef CONFIG_BINFMT_ZFLAT
 583                if (flags & FLAT_FLAG_GZDATA) {
 584                        result = decompress_exec(bprm, fpos, (char *) datapos, 
 585                                                 data_len + (relocs * sizeof(unsigned long)), 0);
 586                } else
 587#endif
 588                {
 589                        result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 590                                        data_len + (relocs * sizeof(unsigned long)), &fpos);
 591                }
 592                if (IS_ERR_VALUE(result)) {
 593                        printk("Unable to read data+bss, errno %d\n", (int)-result);
 594                        do_munmap(current->mm, textpos, text_len);
 595                        do_munmap(current->mm, realdatastart, len);
 596                        ret = result;
 597                        goto err;
 598                }
 599
 600                reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
 601                memp = realdatastart;
 602                memp_size = len;
 603        } else {
 604
 605                len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
 606                len = PAGE_ALIGN(len);
 607                down_write(&current->mm->mmap_sem);
 608                textpos = do_mmap(0, 0, len,
 609                        PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
 610                up_write(&current->mm->mmap_sem);
 611
 612                if (!textpos || IS_ERR_VALUE(textpos)) {
 613                        if (!textpos)
 614                                textpos = (unsigned long) -ENOMEM;
 615                        printk("Unable to allocate RAM for process text/data, errno %d\n",
 616                                        (int)-textpos);
 617                        ret = textpos;
 618                        goto err;
 619                }
 620
 621                realdatastart = textpos + ntohl(hdr->data_start);
 622                datapos = ALIGN(realdatastart +
 623                                MAX_SHARED_LIBS * sizeof(unsigned long),
 624                                FLAT_DATA_ALIGN);
 625
 626                reloc = (unsigned long *)
 627                        (datapos + (ntohl(hdr->reloc_start) - text_len));
 628                memp = textpos;
 629                memp_size = len;
 630#ifdef CONFIG_BINFMT_ZFLAT
 631                /*
 632                 * load it all in and treat it like a RAM load from now on
 633                 */
 634                if (flags & FLAT_FLAG_GZIP) {
 635                        result = decompress_exec(bprm, sizeof (struct flat_hdr),
 636                                         (((char *) textpos) + sizeof (struct flat_hdr)),
 637                                         (text_len + data_len + (relocs * sizeof(unsigned long))
 638                                                  - sizeof (struct flat_hdr)),
 639                                         0);
 640                        memmove((void *) datapos, (void *) realdatastart,
 641                                        data_len + (relocs * sizeof(unsigned long)));
 642                } else if (flags & FLAT_FLAG_GZDATA) {
 643                        fpos = 0;
 644                        result = bprm->file->f_op->read(bprm->file,
 645                                        (char *) textpos, text_len, &fpos);
 646                        if (!IS_ERR_VALUE(result))
 647                                result = decompress_exec(bprm, text_len, (char *) datapos,
 648                                                 data_len + (relocs * sizeof(unsigned long)), 0);
 649                }
 650                else
 651#endif
 652                {
 653                        fpos = 0;
 654                        result = bprm->file->f_op->read(bprm->file,
 655                                        (char *) textpos, text_len, &fpos);
 656                        if (!IS_ERR_VALUE(result)) {
 657                                fpos = ntohl(hdr->data_start);
 658                                result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 659                                        data_len + (relocs * sizeof(unsigned long)), &fpos);
 660                        }
 661                }
 662                if (IS_ERR_VALUE(result)) {
 663                        printk("Unable to read code+data+bss, errno %d\n",(int)-result);
 664                        do_munmap(current->mm, textpos, text_len + data_len + extra +
 665                                MAX_SHARED_LIBS * sizeof(unsigned long));
 666                        ret = result;
 667                        goto err;
 668                }
 669        }
 670
 671        if (flags & FLAT_FLAG_KTRACE)
 672                printk("Mapping is %x, Entry point is %x, data_start is %x\n",
 673                        (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
 674
 675        /* The main program needs a little extra setup in the task structure */
 676        start_code = textpos + sizeof (struct flat_hdr);
 677        end_code = textpos + text_len;
 678        if (id == 0) {
 679                current->mm->start_code = start_code;
 680                current->mm->end_code = end_code;
 681                current->mm->start_data = datapos;
 682                current->mm->end_data = datapos + data_len;
 683                /*
 684                 * set up the brk stuff, uses any slack left in data/bss/stack
 685                 * allocation.  We put the brk after the bss (between the bss
 686                 * and stack) like other platforms.
 687                 * Userspace code relies on the stack pointer starting out at
 688                 * an address right at the end of a page.
 689                 */
 690                current->mm->start_brk = datapos + data_len + bss_len;
 691                current->mm->brk = (current->mm->start_brk + 3) & ~3;
 692                current->mm->context.end_brk = memp + memp_size - stack_len;
 693        }
 694
 695        if (flags & FLAT_FLAG_KTRACE)
 696                printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
 697                        id ? "Lib" : "Load", bprm->filename,
 698                        (int) start_code, (int) end_code,
 699                        (int) datapos,
 700                        (int) (datapos + data_len),
 701                        (int) (datapos + data_len),
 702                        (int) (((datapos + data_len + bss_len) + 3) & ~3));
 703
 704        text_len -= sizeof(struct flat_hdr); /* the real code len */
 705
 706        /* Store the current module values into the global library structure */
 707        libinfo->lib_list[id].start_code = start_code;
 708        libinfo->lib_list[id].start_data = datapos;
 709        libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
 710        libinfo->lib_list[id].text_len = text_len;
 711        libinfo->lib_list[id].loaded = 1;
 712        libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 713        libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
 714        
 715        /*
 716         * We just load the allocations into some temporary memory to
 717         * help simplify all this mumbo jumbo
 718         *
 719         * We've got two different sections of relocation entries.
 720         * The first is the GOT which resides at the begining of the data segment
 721         * and is terminated with a -1.  This one can be relocated in place.
 722         * The second is the extra relocation entries tacked after the image's
 723         * data segment. These require a little more processing as the entry is
 724         * really an offset into the image which contains an offset into the
 725         * image.
 726         */
 727        if (flags & FLAT_FLAG_GOTPIC) {
 728                for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
 729                        unsigned long addr;
 730                        if (*rp) {
 731                                addr = calc_reloc(*rp, libinfo, id, 0);
 732                                if (addr == RELOC_FAILED) {
 733                                        ret = -ENOEXEC;
 734                                        goto err;
 735                                }
 736                                *rp = addr;
 737                        }
 738                }
 739        }
 740
 741        /*
 742         * Now run through the relocation entries.
 743         * We've got to be careful here as C++ produces relocatable zero
 744         * entries in the constructor and destructor tables which are then
 745         * tested for being not zero (which will always occur unless we're
 746         * based from address zero).  This causes an endless loop as __start
 747         * is at zero.  The solution used is to not relocate zero addresses.
 748         * This has the negative side effect of not allowing a global data
 749         * reference to be statically initialised to _stext (I've moved
 750         * __start to address 4 so that is okay).
 751         */
 752        if (rev > OLD_FLAT_VERSION) {
 753                unsigned long persistent = 0;
 754                for (i=0; i < relocs; i++) {
 755                        unsigned long addr, relval;
 756
 757                        /* Get the address of the pointer to be
 758                           relocated (of course, the address has to be
 759                           relocated first).  */
 760                        relval = ntohl(reloc[i]);
 761                        if (flat_set_persistent (relval, &persistent))
 762                                continue;
 763                        addr = flat_get_relocate_addr(relval);
 764                        rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
 765                        if (rp == (unsigned long *)RELOC_FAILED) {
 766                                ret = -ENOEXEC;
 767                                goto err;
 768                        }
 769
 770                        /* Get the pointer's value.  */
 771                        addr = flat_get_addr_from_rp(rp, relval, flags,
 772                                                        &persistent);
 773                        if (addr != 0) {
 774                                /*
 775                                 * Do the relocation.  PIC relocs in the data section are
 776                                 * already in target order
 777                                 */
 778                                if ((flags & FLAT_FLAG_GOTPIC) == 0)
 779                                        addr = ntohl(addr);
 780                                addr = calc_reloc(addr, libinfo, id, 0);
 781                                if (addr == RELOC_FAILED) {
 782                                        ret = -ENOEXEC;
 783                                        goto err;
 784                                }
 785
 786                                /* Write back the relocated pointer.  */
 787                                flat_put_addr_at_rp(rp, addr, relval);
 788                        }
 789                }
 790        } else {
 791                for (i=0; i < relocs; i++)
 792                        old_reloc(ntohl(reloc[i]));
 793        }
 794        
 795        flush_icache_range(start_code, end_code);
 796
 797        /* zero the BSS,  BRK and stack areas */
 798        memset((void*)(datapos + data_len), 0, bss_len + 
 799                        (memp + memp_size - stack_len -         /* end brk */
 800                        libinfo->lib_list[id].start_brk) +      /* start brk */
 801                        stack_len);
 802
 803        return 0;
 804err:
 805        return ret;
 806}
 807
 808
 809/****************************************************************************/
 810#ifdef CONFIG_BINFMT_SHARED_FLAT
 811
 812/*
 813 * Load a shared library into memory.  The library gets its own data
 814 * segment (including bss) but not argv/argc/environ.
 815 */
 816
 817static int load_flat_shared_library(int id, struct lib_info *libs)
 818{
 819        struct linux_binprm bprm;
 820        int res;
 821        char buf[16];
 822
 823        /* Create the file name */
 824        sprintf(buf, "/lib/lib%d.so", id);
 825
 826        /* Open the file up */
 827        bprm.filename = buf;
 828        bprm.file = open_exec(bprm.filename);
 829        res = PTR_ERR(bprm.file);
 830        if (IS_ERR(bprm.file))
 831                return res;
 832
 833        bprm.cred = prepare_exec_creds();
 834        res = -ENOMEM;
 835        if (!bprm.cred)
 836                goto out;
 837
 838        res = prepare_binprm(&bprm);
 839
 840        if (!IS_ERR_VALUE(res))
 841                res = load_flat_file(&bprm, libs, id, NULL);
 842
 843        abort_creds(bprm.cred);
 844
 845out:
 846        allow_write_access(bprm.file);
 847        fput(bprm.file);
 848
 849        return(res);
 850}
 851
 852#endif /* CONFIG_BINFMT_SHARED_FLAT */
 853/****************************************************************************/
 854
 855/*
 856 * These are the functions used to load flat style executables and shared
 857 * libraries.  There is no binary dependent code anywhere else.
 858 */
 859
 860static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 861{
 862        struct lib_info libinfo;
 863        unsigned long p = bprm->p;
 864        unsigned long stack_len;
 865        unsigned long start_addr;
 866        unsigned long *sp;
 867        int res;
 868        int i, j;
 869
 870        memset(&libinfo, 0, sizeof(libinfo));
 871        /*
 872         * We have to add the size of our arguments to our stack size
 873         * otherwise it's too easy for users to create stack overflows
 874         * by passing in a huge argument list.  And yes,  we have to be
 875         * pedantic and include space for the argv/envp array as it may have
 876         * a lot of entries.
 877         */
 878#define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
 879        stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
 880        stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
 881        stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
 882        stack_len += FLAT_STACK_ALIGN - 1;  /* reserve for upcoming alignment */
 883        
 884        res = load_flat_file(bprm, &libinfo, 0, &stack_len);
 885        if (IS_ERR_VALUE(res))
 886                return res;
 887        
 888        /* Update data segment pointers for all libraries */
 889        for (i=0; i<MAX_SHARED_LIBS; i++)
 890                if (libinfo.lib_list[i].loaded)
 891                        for (j=0; j<MAX_SHARED_LIBS; j++)
 892                                (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
 893                                        (libinfo.lib_list[j].loaded)?
 894                                                libinfo.lib_list[j].start_data:UNLOADED_LIB;
 895
 896        install_exec_creds(bprm);
 897        current->flags &= ~PF_FORKNOEXEC;
 898
 899        set_binfmt(&flat_format);
 900
 901        p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
 902        DBG_FLT("p=%x\n", (int)p);
 903
 904        /* copy the arg pages onto the stack, this could be more efficient :-) */
 905        for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
 906                * (char *) --p =
 907                        ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
 908
 909        sp = (unsigned long *) create_flat_tables(p, bprm);
 910        
 911        /* Fake some return addresses to ensure the call chain will
 912         * initialise library in order for us.  We are required to call
 913         * lib 1 first, then 2, ... and finally the main program (id 0).
 914         */
 915        start_addr = libinfo.lib_list[0].entry;
 916
 917#ifdef CONFIG_BINFMT_SHARED_FLAT
 918        for (i = MAX_SHARED_LIBS-1; i>0; i--) {
 919                if (libinfo.lib_list[i].loaded) {
 920                        /* Push previos first to call address */
 921                        --sp;   put_user(start_addr, sp);
 922                        start_addr = libinfo.lib_list[i].entry;
 923                }
 924        }
 925#endif
 926        
 927        /* Stash our initial stack pointer into the mm structure */
 928        current->mm->start_stack = (unsigned long )sp;
 929
 930#ifdef FLAT_PLAT_INIT
 931        FLAT_PLAT_INIT(regs);
 932#endif
 933        DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
 934                (int)regs, (int)start_addr, (int)current->mm->start_stack);
 935        
 936        start_thread(regs, start_addr, current->mm->start_stack);
 937
 938        return 0;
 939}
 940
 941/****************************************************************************/
 942
 943static int __init init_flat_binfmt(void)
 944{
 945        return register_binfmt(&flat_format);
 946}
 947
 948/****************************************************************************/
 949
 950core_initcall(init_flat_binfmt);
 951
 952/****************************************************************************/
 953
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