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/config.h>
  20 #include <linux/kernel.h>
  21 #include <linux/sched.h>
  22 #include <linux/mm.h>
  23 #include <linux/mman.h>
  24 #include <linux/a.out.h>
  25 #include <linux/errno.h>
  26 #include <linux/signal.h>
  27 #include <linux/string.h>
  28 #include <linux/fs.h>
  29 #include <linux/file.h>
  30 #include <linux/stat.h>
  31 #include <linux/fcntl.h>
  32 #include <linux/ptrace.h>
  33 #include <linux/user.h>
  34 #include <linux/slab.h>
  35 #include <linux/binfmts.h>
  36 #include <linux/personality.h>
  37 #include <linux/init.h>
  38 #include <linux/flat.h>
  39 #include <linux/syscalls.h>
  40
  41 #include <asm/byteorder.h>
  42 #include <asm/system.h>
  43 #include <asm/uaccess.h>
  44 #include <asm/unaligned.h>
  45 #include <asm/cacheflush.h>
  46
  47 /****************************************************************************/
  48
  49 #if 0
  50 #define DEBUG 1
  51 #endif
  52
  53 #ifdef DEBUG
  54 #define DBG_FLT(a...)   printk(a)
  55 #else
  56 #define DBG_FLT(a...)
  57 #endif
  58
  59 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  60 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  61
  62 struct lib_info {
  63         struct {
  64                 unsigned long start_code;               /* Start of text segment */
  65                 unsigned long start_data;               /* Start of data segment */
  66                 unsigned long start_brk;                /* End of data segment */
  67                 unsigned long text_len;                 /* Length of text segment */
  68                 unsigned long entry;                    /* Start address for this module */
  69                 unsigned long build_date;               /* When this one was compiled */
  70                 short loaded;                           /* Has this library been loaded? */
  71         } lib_list[MAX_SHARED_LIBS];
  72 };
  73
  74 #ifdef CONFIG_BINFMT_SHARED_FLAT
  75 static int load_flat_shared_library(int id, struct lib_info *p);
  76 #endif
  77
  78 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
  79 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file);
  80
  81 static struct linux_binfmt flat_format = {
  82         .module         = THIS_MODULE,
  83         .load_binary    = load_flat_binary,
  84         .core_dump      = flat_core_dump,
  85         .min_coredump   = PAGE_SIZE
  86 };
  87
  88 /****************************************************************************/
  89 /*
  90  * Routine writes a core dump image in the current directory.
  91  * Currently only a stub-function.
  92  */
  93
  94 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file)
  95 {
  96         printk("Process %s:%d received signr %d and should have core dumped\n",
  97                         current->comm, current->pid, (int) signr);
  98         return(1);
  99 }
 100
 101 /****************************************************************************/
 102 /*
 103  * create_flat_tables() parses the env- and arg-strings in new user
 104  * memory and creates the pointer tables from them, and puts their
 105  * addresses on the "stack", returning the new stack pointer value.
 106  */
 107
 108 static unsigned long create_flat_tables(
 109         unsigned long pp,
 110         struct linux_binprm * bprm)
 111 {
 112         unsigned long *argv,*envp;
 113         unsigned long * sp;
 114         char * p = (char*)pp;
 115         int argc = bprm->argc;
 116         int envc = bprm->envc;
 117         char dummy;
 118
 119         sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p);
 120
 121         sp -= envc+1;
 122         envp = sp;
 123         sp -= argc+1;
 124         argv = sp;
 125
 126         flat_stack_align(sp);
 127         if (flat_argvp_envp_on_stack()) {
 128                 --sp; put_user((unsigned long) envp, sp);
 129                 --sp; put_user((unsigned long) argv, sp);
 130         }
 131
 132         put_user(argc,--sp);
 133         current->mm->arg_start = (unsigned long) p;
 134         while (argc-->0) {
 135                 put_user((unsigned long) p, argv++);
 136                 do {
 137                         get_user(dummy, p); p++;
 138                 } while (dummy);
 139         }
 140         put_user((unsigned long) NULL, argv);
 141         current->mm->arg_end = current->mm->env_start = (unsigned long) p;
 142         while (envc-->0) {
 143                 put_user((unsigned long)p, envp); envp++;
 144                 do {
 145                         get_user(dummy, p); p++;
 146                 } while (dummy);
 147         }
 148         put_user((unsigned long) NULL, envp);
 149         current->mm->env_end = (unsigned long) p;
 150         return (unsigned long)sp;
 151 }
 152
 153 /****************************************************************************/
 154
 155 #ifdef CONFIG_BINFMT_ZFLAT
 156
 157 #include <linux/zlib.h>
 158
 159 #define LBUFSIZE        4000
 160
 161 /* gzip flag byte */
 162 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 163 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 164 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 165 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 166 #define COMMENT      0x10 /* bit 4 set: file comment present */
 167 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 168 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 169
 170 static int decompress_exec(
 171         struct linux_binprm *bprm,
 172         unsigned long offset,
 173         char *dst,
 174         long len,
 175         int fd)
 176 {
 177         unsigned char *buf;
 178         z_stream strm;
 179         loff_t fpos;
 180         int ret, retval;
 181
 182         DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
 183
 184         memset(&strm, 0, sizeof(strm));
 185         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 186         if (strm.workspace == NULL) {
 187                 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
 188                 return -ENOMEM;
 189         }
 190         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 191         if (buf == NULL) {
 192                 DBG_FLT("binfmt_flat: no memory for read buffer\n");
 193                 retval = -ENOMEM;
 194                 goto out_free;
 195         }
 196
 197         /* Read in first chunk of data and parse gzip header. */
 198         fpos = offset;
 199         ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 200
 201         strm.next_in = buf;
 202         strm.avail_in = ret;
 203         strm.total_in = 0;
 204
 205         retval = -ENOEXEC;
 206
 207         /* Check minimum size -- gzip header */
 208         if (ret < 10) {
 209                 DBG_FLT("binfmt_flat: file too small?\n");
 210                 goto out_free_buf;
 211         }
 212
 213         /* Check gzip magic number */
 214         if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 215                 DBG_FLT("binfmt_flat: unknown compression magic?\n");
 216                 goto out_free_buf;
 217         }
 218
 219         /* Check gzip method */
 220         if (buf[2] != 8) {
 221                 DBG_FLT("binfmt_flat: unknown compression method?\n");
 222                 goto out_free_buf;
 223         }
 224         /* Check gzip flags */
 225         if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 226             (buf[3] & RESERVED)) {
 227                 DBG_FLT("binfmt_flat: unknown flags?\n");
 228                 goto out_free_buf;
 229         }
 230
 231         ret = 10;
 232         if (buf[3] & EXTRA_FIELD) {
 233                 ret += 2 + buf[10] + (buf[11] << 8);
 234                 if (unlikely(LBUFSIZE == ret)) {
 235                         DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
 236                         goto out_free_buf;
 237                 }
 238         }
 239         if (buf[3] & ORIG_NAME) {
 240                 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
 241                         ;
 242                 if (unlikely(LBUFSIZE == ret)) {
 243                         DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
 244                         goto out_free_buf;
 245                 }
 246         }
 247         if (buf[3] & COMMENT) {
 248                 for (;  ret < LBUFSIZE && (buf[ret] != 0); ret++)
 249                         ;
 250                 if (unlikely(LBUFSIZE == ret)) {
 251                         DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
 252                         goto out_free_buf;
 253                 }
 254         }
 255
 256         strm.next_in += ret;
 257         strm.avail_in -= ret;
 258
 259         strm.next_out = dst;
 260         strm.avail_out = len;
 261         strm.total_out = 0;
 262
 263         if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 264                 DBG_FLT("binfmt_flat: zlib init failed?\n");
 265                 goto out_free_buf;
 266         }
 267
 268         while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 269                 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 270                 if (ret <= 0)
 271                         break;
 272                 if (ret >= (unsigned long) -4096)
 273                         break;
 274                 len -= ret;
 275
 276                 strm.next_in = buf;
 277                 strm.avail_in = ret;
 278                 strm.total_in = 0;
 279         }
 280
 281         if (ret < 0) {
 282                 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
 283                         ret, strm.msg);
 284                 goto out_zlib;
 285         }
 286
 287         retval = 0;
 288 out_zlib:
 289         zlib_inflateEnd(&strm);
 290 out_free_buf:
 291         kfree(buf);
 292 out_free:
 293         kfree(strm.workspace);
 294 out:
 295         return retval;
 296 }
 297
 298 #endif /* CONFIG_BINFMT_ZFLAT */
 299
 300 /****************************************************************************/
 301
 302 static unsigned long
 303 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 304 {
 305         unsigned long addr;
 306         int id;
 307         unsigned long start_brk;
 308         unsigned long start_data;
 309         unsigned long text_len;
 310         unsigned long start_code;
 311
 312 #ifdef CONFIG_BINFMT_SHARED_FLAT
 313         if (r == 0)
 314                 id = curid;     /* Relocs of 0 are always self referring */
 315         else {
 316                 id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 317                 r &= 0x00ffffff;        /* Trim ID off here */
 318         }
 319         if (id >= MAX_SHARED_LIBS) {
 320                 printk("BINFMT_FLAT: reference 0x%x to shared library %d",
 321                                 (unsigned) r, id);
 322                 goto failed;
 323         }
 324         if (curid != id) {
 325                 if (internalp) {
 326                         printk("BINFMT_FLAT: reloc address 0x%x not in same module "
 327                                         "(%d != %d)", (unsigned) r, curid, id);
 328                         goto failed;
 329                 } else if ( ! p->lib_list[id].loaded &&
 330                                 load_flat_shared_library(id, p) > (unsigned long) -4096) {
 331                         printk("BINFMT_FLAT: failed to load library %d", id);
 332                         goto failed;
 333                 }
 334                 /* Check versioning information (i.e. time stamps) */
 335                 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
 336                                 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
 337                         printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
 338                         goto failed;
 339                 }
 340         }
 341 #else
 342         id = 0;
 343 #endif
 344
 345         start_brk = p->lib_list[id].start_brk;
 346         start_data = p->lib_list[id].start_data;
 347         start_code = p->lib_list[id].start_code;
 348         text_len = p->lib_list[id].text_len;
 349
 350         if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
 351                 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
 352                        (int) r,(int)(start_brk-start_code),(int)text_len);
 353                 goto failed;
 354         }
 355
 356         if (r < text_len)                       /* In text segment */
 357                 addr = r + start_code;
 358         else                                    /* In data segment */
 359                 addr = r - text_len + start_data;
 360
 361         /* Range checked already above so doing the range tests is redundant...*/
 362         return(addr);
 363
 364 failed:
 365         printk(", killing %s!\n", current->comm);
 366         send_sig(SIGSEGV, current, 0);
 367
 368         return RELOC_FAILED;
 369 }
 370
 371 /****************************************************************************/
 372
 373 void old_reloc(unsigned long rl)
 374 {
 375 #ifdef DEBUG
 376         char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 377 #endif
 378         flat_v2_reloc_t r;
 379         unsigned long *ptr;
 380
 381         r.value = rl;
 382 #if defined(CONFIG_COLDFIRE)
 383         ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
 384 #else
 385         ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
 386 #endif
 387
 388 #ifdef DEBUG
 389         printk("Relocation of variable at DATASEG+%x "
 390                 "(address %p, currently %x) into segment %s\n",
 391                 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
 392 #endif
 393
 394         switch (r.reloc.type) {
 395         case OLD_FLAT_RELOC_TYPE_TEXT:
 396                 *ptr += current->mm->start_code;
 397                 break;
 398         case OLD_FLAT_RELOC_TYPE_DATA:
 399                 *ptr += current->mm->start_data;
 400                 break;
 401         case OLD_FLAT_RELOC_TYPE_BSS:
 402                 *ptr += current->mm->end_data;
 403                 break;
 404         default:
 405                 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
 406                 break;
 407         }
 408
 409 #ifdef DEBUG
 410         printk("Relocation became %x\n", (int)*ptr);
 411 #endif
 412 }
 413
 414 /****************************************************************************/
 415
 416 static int load_flat_file(struct linux_binprm * bprm,
 417                 struct lib_info *libinfo, int id, unsigned long *extra_stack)
 418 {
 419         struct flat_hdr * hdr;
 420         unsigned long textpos = 0, datapos = 0, result;
 421         unsigned long realdatastart = 0;
 422         unsigned long text_len, data_len, bss_len, stack_len, flags;
 423         unsigned long memp = 0; /* for finding the brk area */
 424         unsigned long extra, rlim;
 425         unsigned long *reloc = 0, *rp;
 426         struct inode *inode;
 427         int i, rev, relocs = 0;
 428         loff_t fpos;
 429         unsigned long start_code, end_code;
 430         int ret;
 431         int exec_fileno;
 432
 433         hdr = ((struct flat_hdr *) bprm->buf);          /* exec-header */
 434         inode = bprm->file->f_dentry->d_inode;
 435
 436         text_len  = ntohl(hdr->data_start);
 437         data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 438         bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 439         stack_len = ntohl(hdr->stack_size);
 440         if (extra_stack) {
 441                 stack_len += *extra_stack;
 442                 *extra_stack = stack_len;
 443         }
 444         relocs    = ntohl(hdr->reloc_count);
 445         flags     = ntohl(hdr->flags);
 446         rev       = ntohl(hdr->rev);
 447
 448         if (strncmp(hdr->magic, "bFLT", 4)) {
 449                 /*
 450                  * because a lot of people do not manage to produce good
 451                  * flat binaries,  we leave this printk to help them realise
 452                  * the problem.  We only print the error if its not a script file
 453                  */
 454                 if (strncmp(hdr->magic, "#!", 2))
 455                         printk("BINFMT_FLAT: bad header magic\n");
 456                 ret = -ENOEXEC;
 457                 goto err;
 458         }
 459
 460         if (flags & FLAT_FLAG_KTRACE)
 461                 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
 462
 463         if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 464                 printk("BINFMT_FLAT: bad flat file version 0x%x (supported 0x%x and 0x%x)\n", rev, FLAT_VERSION, OLD_FLAT_VERSION);
 465                 ret = -ENOEXEC;
 466                 goto err;
 467         }
 468
 469         /* Don't allow old format executables to use shared libraries */
 470         if (rev == OLD_FLAT_VERSION && id != 0) {
 471                 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
 472                                 (int) FLAT_VERSION);
 473                 ret = -ENOEXEC;
 474                 goto err;
 475         }
 476
 477         /*
 478          * fix up the flags for the older format,  there were all kinds
 479          * of endian hacks,  this only works for the simple cases
 480          */
 481         if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 482                 flags = FLAT_FLAG_RAM;
 483
 484 #ifndef CONFIG_BINFMT_ZFLAT
 485         if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 486                 printk("Support for ZFLAT executables is not enabled.\n");
 487                 ret = -ENOEXEC;
 488                 goto err;
 489         }
 490 #endif
 491
 492         /*
 493          * Check initial limits. This avoids letting people circumvent
 494          * size limits imposed on them by creating programs with large
 495          * arrays in the data or bss.
 496          */
 497         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
 498         if (rlim >= RLIM_INFINITY)
 499                 rlim = ~0;
 500         if (data_len + bss_len > rlim) {
 501                 ret = -ENOMEM;
 502                 goto err;
 503         }
 504
 505         /* check file descriptor */
 506         exec_fileno = get_unused_fd();
 507         if (exec_fileno < 0) {
 508                 ret = -EMFILE;
 509                 goto err;
 510         }
 511         get_file(bprm->file);
 512         fd_install(exec_fileno, bprm->file);
 513
 514         /* Flush all traces of the currently running executable */
 515         if (id == 0) {
 516                 result = flush_old_exec(bprm);
 517                 if (result) {
 518                         ret = result;
 519                         goto err_close;
 520                 }
 521
 522                 /* OK, This is the point of no return */
 523                 set_personality(PER_LINUX);
 524         }
 525
 526         /*
 527          * calculate the extra space we need to map in
 528          */
 529         extra = max(bss_len + stack_len, relocs * sizeof(unsigned long));
 530
 531         /*
 532          * there are a couple of cases here,  the separate code/data
 533          * case,  and then the fully copied to RAM case which lumps
 534          * it all together.
 535          */
 536         if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
 537                 /*
 538                  * this should give us a ROM ptr,  but if it doesn't we don't
 539                  * really care
 540                  */
 541                 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
 542
 543                 down_write(&current->mm->mmap_sem);
 544                 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0);
 545                 up_write(&current->mm->mmap_sem);
 546                 if (!textpos  || textpos >= (unsigned long) -4096) {
 547                         if (!textpos)
 548                                 textpos = (unsigned long) -ENOMEM;
 549                         printk("Unable to mmap process text, errno %d\n", (int)-textpos);
 550                         ret = textpos;
 551                         goto err_close;
 552                 }
 553
 554                 down_write(&current->mm->mmap_sem);
 555                 realdatastart = do_mmap(0, 0, data_len + extra +
 556                                 MAX_SHARED_LIBS * sizeof(unsigned long),
 557                                 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
 558                 up_write(&current->mm->mmap_sem);
 559
 560                 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
 561                         if (!realdatastart)
 562                                 realdatastart = (unsigned long) -ENOMEM;
 563                         printk("Unable to allocate RAM for process data, errno %d\n",
 564                                         (int)-datapos);
 565                         do_munmap(current->mm, textpos, text_len);
 566                         ret = realdatastart;
 567                         goto err_close;
 568                 }
 569                 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
 570
 571                 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
 572                                 (int)(data_len + bss_len + stack_len), (int)datapos);
 573
 574                 fpos = ntohl(hdr->data_start);
 575 #ifdef CONFIG_BINFMT_ZFLAT
 576                 if (flags & FLAT_FLAG_GZDATA) {
 577                         result = decompress_exec(bprm, fpos, (char *) datapos,
 578                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 579                 } else
 580 #endif
 581                 {
 582                         result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 583                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 584                 }
 585                 if (result >= (unsigned long)-4096) {
 586                         printk("Unable to read data+bss, errno %d\n", (int)-result);
 587                         do_munmap(current->mm, textpos, text_len);
 588                         do_munmap(current->mm, realdatastart, data_len + extra);
 589                         ret = result;
 590                         goto err_close;
 591                 }
 592
 593                 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
 594                 memp = realdatastart;
 595
 596         } else {
 597
 598                 down_write(&current->mm->mmap_sem);
 599                 textpos = do_mmap(0, 0, text_len + data_len + extra +
 600                                         MAX_SHARED_LIBS * sizeof(unsigned long),
 601                                 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
 602                 up_write(&current->mm->mmap_sem);
 603                 if (!textpos  || textpos >= (unsigned long) -4096) {
 604                         if (!textpos)
 605                                 textpos = (unsigned long) -ENOMEM;
 606                         printk("Unable to allocate RAM for process text/data, errno %d\n",
 607                                         (int)-textpos);
 608                         ret = textpos;
 609                         goto err_close;
 610                 }
 611
 612                 realdatastart = textpos + ntohl(hdr->data_start);
 613                 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
 614                 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
 615                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 616                 memp = textpos;
 617
 618 #ifdef CONFIG_BINFMT_ZFLAT
 619                 /*
 620                  * load it all in and treat it like a RAM load from now on
 621                  */
 622                 if (flags & FLAT_FLAG_GZIP) {
 623                         result = decompress_exec(bprm, sizeof (struct flat_hdr),
 624                                          (((char *) textpos) + sizeof (struct flat_hdr)),
 625                                          (text_len + data_len + (relocs * sizeof(unsigned long))
 626                                                   - sizeof (struct flat_hdr)),
 627                                          0);
 628                         memmove((void *) datapos, (void *) realdatastart,
 629                                         data_len + (relocs * sizeof(unsigned long)));
 630                 } else if (flags & FLAT_FLAG_GZDATA) {
 631                         fpos = 0;
 632                         result = bprm->file->f_op->read(bprm->file,
 633                                         (char *) textpos, text_len, &fpos);
 634                         if (result < (unsigned long) -4096)
 635                                 result = decompress_exec(bprm, text_len, (char *) datapos,
 636                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 637                 }
 638                 else
 639 #endif
 640                 {
 641                         fpos = 0;
 642                         result = bprm->file->f_op->read(bprm->file,
 643                                         (char *) textpos, text_len, &fpos);
 644                         if (result < (unsigned long) -4096) {
 645                                 fpos = ntohl(hdr->data_start);
 646                                 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 647                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 648                         }
 649                 }
 650                 if (result >= (unsigned long)-4096) {
 651                         printk("Unable to read code+data+bss, errno %d\n",(int)-result);
 652                         do_munmap(current->mm, textpos, text_len + data_len + extra +
 653                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 654                         ret = result;
 655                         goto err_close;
 656                 }
 657         }
 658
 659         if (flags & FLAT_FLAG_KTRACE)
 660                 printk("Mapping is %x, Entry point is %x, data_start is %x\n",
 661                         (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
 662
 663         /* The main program needs a little extra setup in the task structure */
 664         start_code = textpos + sizeof (struct flat_hdr);
 665         end_code = textpos + text_len;
 666         if (id == 0) {
 667                 current->mm->start_code = start_code;
 668                 current->mm->end_code = end_code;
 669                 current->mm->start_data = datapos;
 670                 current->mm->end_data = datapos + data_len;
 671                 /*
 672                  * set up the brk stuff, uses any slack left in data/bss/stack
 673                  * allocation.  We put the brk after the bss (between the bss
 674                  * and stack) like other platforms.
 675                  */
 676                 current->mm->start_brk = datapos + data_len + bss_len;
 677                 current->mm->brk = (current->mm->start_brk + 3) & ~3;
 678                 current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len;
 679         }
 680
 681         if (flags & FLAT_FLAG_KTRACE)
 682                 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
 683                         id ? "Lib" : "Load", bprm->filename,
 684                         (int) start_code, (int) end_code,
 685                         (int) datapos,
 686                         (int) (datapos + data_len),
 687                         (int) (datapos + data_len),
 688                         (int) (((datapos + data_len + bss_len) + 3) & ~3));
 689
 690         text_len -= sizeof(struct flat_hdr); /* the real code len */
 691
 692         /* Store the current module values into the global library structure */
 693         libinfo->lib_list[id].start_code = start_code;
 694         libinfo->lib_list[id].start_data = datapos;
 695         libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
 696         libinfo->lib_list[id].text_len = text_len;
 697         libinfo->lib_list[id].loaded = 1;
 698         libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 699         libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
 700
 701         /*
 702          * We just load the allocations into some temporary memory to
 703          * help simplify all this mumbo jumbo
 704          *
 705          * We've got two different sections of relocation entries.
 706          * The first is the GOT which resides at the begining of the data segment
 707          * and is terminated with a -1.  This one can be relocated in place.
 708          * The second is the extra relocation entries tacked after the image's
 709          * data segment. These require a little more processing as the entry is
 710          * really an offset into the image which contains an offset into the
 711          * image.
 712          */
 713         if (flags & FLAT_FLAG_GOTPIC) {
 714                 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
 715                         unsigned long addr;
 716                         if (*rp) {
 717                                 addr = calc_reloc(*rp, libinfo, id, 0);
 718                                 if (addr == RELOC_FAILED) {
 719                                         ret = -ENOEXEC;
 720                                         goto err_close;
 721                                 }
 722                                 *rp = addr;
 723                         }
 724                 }
 725         }
 726
 727         /*
 728          * Now run through the relocation entries.
 729          * We've got to be careful here as C++ produces relocatable zero
 730          * entries in the constructor and destructor tables which are then
 731          * tested for being not zero (which will always occur unless we're
 732          * based from address zero).  This causes an endless loop as __start
 733          * is at zero.  The solution used is to not relocate zero addresses.
 734          * This has the negative side effect of not allowing a global data
 735          * reference to be statically initialised to _stext (I've moved
 736          * __start to address 4 so that is okay).
 737          */
 738         if (rev > OLD_FLAT_VERSION) {
 739                 for (i=0; i < relocs; i++) {
 740                         unsigned long addr, relval;
 741
 742                         /* Get the address of the pointer to be
 743                            relocated (of course, the address has to be
 744                            relocated first).  */
 745                         relval = ntohl(reloc[i]);
 746                         addr = flat_get_relocate_addr(relval);
 747                         rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
 748                         if (rp == (unsigned long *)RELOC_FAILED) {
 749                                 ret = -ENOEXEC;
 750                                 goto err_close;
 751                         }
 752
 753                         /* Get the pointer's value.  */
 754                         addr = flat_get_addr_from_rp(rp, relval, flags);
 755                         if (addr != 0) {
 756                                 /*
 757                                  * Do the relocation.  PIC relocs in the data section are
 758                                  * already in target order
 759                                  */
 760                                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
 761                                         addr = ntohl(addr);
 762                                 addr = calc_reloc(addr, libinfo, id, 0);
 763                                 if (addr == RELOC_FAILED) {
 764                                         ret = -ENOEXEC;
 765                                         goto err_close;
 766                                 }
 767
 768                                 /* Write back the relocated pointer.  */
 769                                 flat_put_addr_at_rp(rp, addr, relval);
 770                         }
 771                 }
 772         } else {
 773                 for (i=0; i < relocs; i++)
 774                         old_reloc(ntohl(reloc[i]));
 775         }
 776
 777         flush_icache_range(start_code, end_code);
 778
 779         /* zero the BSS,  BRK and stack areas */
 780         memset((void*)(datapos + data_len), 0, bss_len +
 781                         (memp + ksize((void *) memp) - stack_len -      /* end brk */
 782                         libinfo->lib_list[id].start_brk) +              /* start brk */
 783                         stack_len);
 784
 785         return 0;
 786 err_close:
 787         sys_close(exec_fileno);
 788 err:
 789         return ret;
 790 }
 791
 792
 793 /****************************************************************************/
 794 #ifdef CONFIG_BINFMT_SHARED_FLAT
 795
 796 /*
 797  * Load a shared library into memory.  The library gets its own data
 798  * segment (including bss) but not argv/argc/environ.
 799  */
 800
 801 static int load_flat_shared_library(int id, struct lib_info *libs)
 802 {
 803         struct linux_binprm bprm;
 804         int res;
 805         char buf[16];
 806
 807         /* Create the file name */
 808         sprintf(buf, "/lib/lib%d.so", id);
 809
 810         /* Open the file up */
 811         bprm.filename = buf;
 812         bprm.file = open_exec(bprm.filename);
 813         res = PTR_ERR(bprm.file);
 814         if (IS_ERR(bprm.file))
 815                 return res;
 816
 817         res = prepare_binprm(&bprm);
 818
 819         if (res <= (unsigned long)-4096)
 820                 res = load_flat_file(&bprm, libs, id, NULL);
 821         if (bprm.file) {
 822                 allow_write_access(bprm.file);
 823                 fput(bprm.file);
 824                 bprm.file = NULL;
 825         }
 826         return(res);
 827 }
 828
 829 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 830 /****************************************************************************/
 831
 832 /*
 833  * These are the functions used to load flat style executables and shared
 834  * libraries.  There is no binary dependent code anywhere else.
 835  */
 836
 837 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 838 {
 839         struct lib_info libinfo;
 840         unsigned long p = bprm->p;
 841         unsigned long stack_len;
 842         unsigned long start_addr;
 843         unsigned long *sp;
 844         int res;
 845         int i, j;
 846
 847         memset(&libinfo, 0, sizeof(libinfo));
 848         /*
 849          * We have to add the size of our arguments to our stack size
 850          * otherwise it's too easy for users to create stack overflows
 851          * by passing in a huge argument list.  And yes,  we have to be
 852          * pedantic and include space for the argv/envp array as it may have
 853          * a lot of entries.
 854          */
 855 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
 856         stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
 857         stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
 858         stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
 859
 860
 861         res = load_flat_file(bprm, &libinfo, 0, &stack_len);
 862         if (res > (unsigned long)-4096)
 863                 return res;
 864
 865         /* Update data segment pointers for all libraries */
 866         for (i=0; i<MAX_SHARED_LIBS; i++)
 867                 if (libinfo.lib_list[i].loaded)
 868                         for (j=0; j<MAX_SHARED_LIBS; j++)
 869                                 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
 870                                         (libinfo.lib_list[j].loaded)?
 871                                                 libinfo.lib_list[j].start_data:UNLOADED_LIB;
 872
 873         compute_creds(bprm);
 874         current->flags &= ~PF_FORKNOEXEC;
 875
 876         set_binfmt(&flat_format);
 877
 878         p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
 879         DBG_FLT("p=%x\n", (int)p);
 880
 881         /* copy the arg pages onto the stack, this could be more efficient :-) */
 882         for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
 883                 * (char *) --p =
 884                         ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
 885
 886         sp = (unsigned long *) create_flat_tables(p, bprm);
 887
 888         /* Fake some return addresses to ensure the call chain will
 889          * initialise library in order for us.  We are required to call
 890          * lib 1 first, then 2, ... and finally the main program (id 0).
 891          */
 892         start_addr = libinfo.lib_list[0].entry;
 893
 894 #ifdef CONFIG_BINFMT_SHARED_FLAT
 895         for (i = MAX_SHARED_LIBS-1; i>0; i--) {
 896                 if (libinfo.lib_list[i].loaded) {
 897                         /* Push previos first to call address */
 898                         --sp;   put_user(start_addr, sp);
 899                         start_addr = libinfo.lib_list[i].entry;
 900                 }
 901         }
 902 #endif
 903
 904         /* Stash our initial stack pointer into the mm structure */
 905         current->mm->start_stack = (unsigned long )sp;
 906
 907
 908         DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
 909                 (int)regs, (int)start_addr, (int)current->mm->start_stack);
 910
 911         start_thread(regs, start_addr, current->mm->start_stack);
 912
 913         if (current->ptrace & PT_PTRACED)
 914                 send_sig(SIGTRAP, current, 0);
 915
 916         return 0;
 917 }
 918
 919 /****************************************************************************/
 920
 921 static int __init init_flat_binfmt(void)
 922 {
 923         return register_binfmt(&flat_format);
 924 }
 925
 926 static void __exit exit_flat_binfmt(void)
 927 {
 928         unregister_binfmt(&flat_format);
 929 }
 930
 931 /****************************************************************************/
 932
 933 core_initcall(init_flat_binfmt);
 934 module_exit(exit_flat_binfmt);
 935
 936 /****************************************************************************/