fs/binfmt_flat.c

   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
  76 struct 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
  89 static int load_flat_shared_library(int id, struct lib_info *p);
  90 #endif
  91
  92 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
  93 static int flat_core_dump(struct coredump_params *cprm);
  94
  95 static 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
 108 static 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
 122 static 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
 182 static 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;
 298 out_zlib:
 299         zlib_inflateEnd(&strm);
 300 out_free_buf:
 301         kfree(buf);
 302 out_free:
 303         kfree(strm.workspace);
 304         return retval;
 305 }
 306
 307 #endif /* CONFIG_BINFMT_ZFLAT */
 308
 309 /****************************************************************************/
 310
 311 static unsigned long
 312 calc_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
 373 failed:
 374         printk(", killing %s!\n", current->comm);
 375         send_sig(SIGSEGV, current, 0);
 376
 377         return RELOC_FAILED;
 378 }
 379
 380 /****************************************************************************/
 381
 382 void 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
 425 static 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;
 804 err:
 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
 817 static 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
 845 out:
 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
 860 static 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
 943 static int __init init_flat_binfmt(void)
 944 {
 945         return register_binfmt(&flat_format);
 946 }
 947
 948 /****************************************************************************/
 949
 950 core_initcall(init_flat_binfmt);
 951
 952 /****************************************************************************/