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
 432         hdr = ((struct flat_hdr *) bprm->buf);          /* exec-header */
 433         inode = bprm->file->f_dentry->d_inode;
 434
 435         text_len  = ntohl(hdr->data_start);
 436         data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 437         bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 438         stack_len = ntohl(hdr->stack_size);
 439         if (extra_stack) {
 440                 stack_len += *extra_stack;
 441                 *extra_stack = stack_len;
 442         }
 443         relocs    = ntohl(hdr->reloc_count);
 444         flags     = ntohl(hdr->flags);
 445         rev       = ntohl(hdr->rev);
 446
 447         if (strncmp(hdr->magic, "bFLT", 4)) {
 448                 /*
 449                  * because a lot of people do not manage to produce good
 450                  * flat binaries,  we leave this printk to help them realise
 451                  * the problem.  We only print the error if its not a script file
 452                  */
 453                 if (strncmp(hdr->magic, "#!", 2))
 454                         printk("BINFMT_FLAT: bad header magic\n");
 455                 ret = -ENOEXEC;
 456                 goto err;
 457         }
 458
 459         if (flags & FLAT_FLAG_KTRACE)
 460                 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
 461
 462         if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 463                 printk("BINFMT_FLAT: bad flat file version 0x%x (supported 0x%x and 0x%x)\n", rev, FLAT_VERSION, OLD_FLAT_VERSION);
 464                 ret = -ENOEXEC;
 465                 goto err;
 466         }
 467
 468         /* Don't allow old format executables to use shared libraries */
 469         if (rev == OLD_FLAT_VERSION && id != 0) {
 470                 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
 471                                 (int) FLAT_VERSION);
 472                 ret = -ENOEXEC;
 473                 goto err;
 474         }
 475
 476         /*
 477          * fix up the flags for the older format,  there were all kinds
 478          * of endian hacks,  this only works for the simple cases
 479          */
 480         if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 481                 flags = FLAT_FLAG_RAM;
 482
 483 #ifndef CONFIG_BINFMT_ZFLAT
 484         if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 485                 printk("Support for ZFLAT executables is not enabled.\n");
 486                 ret = -ENOEXEC;
 487                 goto err;
 488         }
 489 #endif
 490
 491         /*
 492          * Check initial limits. This avoids letting people circumvent
 493          * size limits imposed on them by creating programs with large
 494          * arrays in the data or bss.
 495          */
 496         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
 497         if (rlim >= RLIM_INFINITY)
 498                 rlim = ~0;
 499         if (data_len + bss_len > rlim) {
 500                 ret = -ENOMEM;
 501                 goto err;
 502         }
 503
 504         /* Flush all traces of the currently running executable */
 505         if (id == 0) {
 506                 result = flush_old_exec(bprm);
 507                 if (result) {
 508                         ret = result;
 509                         goto err;
 510                 }
 511
 512                 /* OK, This is the point of no return */
 513                 set_personality(PER_LINUX);
 514         }
 515
 516         /*
 517          * calculate the extra space we need to map in
 518          */
 519         extra = max(bss_len + stack_len, relocs * sizeof(unsigned long));
 520
 521         /*
 522          * there are a couple of cases here,  the separate code/data
 523          * case,  and then the fully copied to RAM case which lumps
 524          * it all together.
 525          */
 526         if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
 527                 /*
 528                  * this should give us a ROM ptr,  but if it doesn't we don't
 529                  * really care
 530                  */
 531                 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
 532
 533                 down_write(&current->mm->mmap_sem);
 534                 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0);
 535                 up_write(&current->mm->mmap_sem);
 536                 if (!textpos  || textpos >= (unsigned long) -4096) {
 537                         if (!textpos)
 538                                 textpos = (unsigned long) -ENOMEM;
 539                         printk("Unable to mmap process text, errno %d\n", (int)-textpos);
 540                         ret = textpos;
 541                         goto err;
 542                 }
 543
 544                 down_write(&current->mm->mmap_sem);
 545                 realdatastart = do_mmap(0, 0, data_len + extra +
 546                                 MAX_SHARED_LIBS * sizeof(unsigned long),
 547                                 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
 548                 up_write(&current->mm->mmap_sem);
 549
 550                 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
 551                         if (!realdatastart)
 552                                 realdatastart = (unsigned long) -ENOMEM;
 553                         printk("Unable to allocate RAM for process data, errno %d\n",
 554                                         (int)-datapos);
 555                         do_munmap(current->mm, textpos, text_len);
 556                         ret = realdatastart;
 557                         goto err;
 558                 }
 559                 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
 560
 561                 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
 562                                 (int)(data_len + bss_len + stack_len), (int)datapos);
 563
 564                 fpos = ntohl(hdr->data_start);
 565 #ifdef CONFIG_BINFMT_ZFLAT
 566                 if (flags & FLAT_FLAG_GZDATA) {
 567                         result = decompress_exec(bprm, fpos, (char *) datapos,
 568                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 569                 } else
 570 #endif
 571                 {
 572                         result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 573                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 574                 }
 575                 if (result >= (unsigned long)-4096) {
 576                         printk("Unable to read data+bss, errno %d\n", (int)-result);
 577                         do_munmap(current->mm, textpos, text_len);
 578                         do_munmap(current->mm, realdatastart, data_len + extra);
 579                         ret = result;
 580                         goto err;
 581                 }
 582
 583                 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
 584                 memp = realdatastart;
 585
 586         } else {
 587
 588                 down_write(&current->mm->mmap_sem);
 589                 textpos = do_mmap(0, 0, text_len + data_len + extra +
 590                                         MAX_SHARED_LIBS * sizeof(unsigned long),
 591                                 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
 592                 up_write(&current->mm->mmap_sem);
 593                 if (!textpos  || textpos >= (unsigned long) -4096) {
 594                         if (!textpos)
 595                                 textpos = (unsigned long) -ENOMEM;
 596                         printk("Unable to allocate RAM for process text/data, errno %d\n",
 597                                         (int)-textpos);
 598                         ret = textpos;
 599                         goto err;
 600                 }
 601
 602                 realdatastart = textpos + ntohl(hdr->data_start);
 603                 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
 604                 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
 605                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 606                 memp = textpos;
 607
 608 #ifdef CONFIG_BINFMT_ZFLAT
 609                 /*
 610                  * load it all in and treat it like a RAM load from now on
 611                  */
 612                 if (flags & FLAT_FLAG_GZIP) {
 613                         result = decompress_exec(bprm, sizeof (struct flat_hdr),
 614                                          (((char *) textpos) + sizeof (struct flat_hdr)),
 615                                          (text_len + data_len + (relocs * sizeof(unsigned long))
 616                                                   - sizeof (struct flat_hdr)),
 617                                          0);
 618                         memmove((void *) datapos, (void *) realdatastart,
 619                                         data_len + (relocs * sizeof(unsigned long)));
 620                 } else if (flags & FLAT_FLAG_GZDATA) {
 621                         fpos = 0;
 622                         result = bprm->file->f_op->read(bprm->file,
 623                                         (char *) textpos, text_len, &fpos);
 624                         if (result < (unsigned long) -4096)
 625                                 result = decompress_exec(bprm, text_len, (char *) datapos,
 626                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 627                 }
 628                 else
 629 #endif
 630                 {
 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                                 fpos = ntohl(hdr->data_start);
 636                                 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 637                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 638                         }
 639                 }
 640                 if (result >= (unsigned long)-4096) {
 641                         printk("Unable to read code+data+bss, errno %d\n",(int)-result);
 642                         do_munmap(current->mm, textpos, text_len + data_len + extra +
 643                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 644                         ret = result;
 645                         goto err;
 646                 }
 647         }
 648
 649         if (flags & FLAT_FLAG_KTRACE)
 650                 printk("Mapping is %x, Entry point is %x, data_start is %x\n",
 651                         (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
 652
 653         /* The main program needs a little extra setup in the task structure */
 654         start_code = textpos + sizeof (struct flat_hdr);
 655         end_code = textpos + text_len;
 656         if (id == 0) {
 657                 current->mm->start_code = start_code;
 658                 current->mm->end_code = end_code;
 659                 current->mm->start_data = datapos;
 660                 current->mm->end_data = datapos + data_len;
 661                 /*
 662                  * set up the brk stuff, uses any slack left in data/bss/stack
 663                  * allocation.  We put the brk after the bss (between the bss
 664                  * and stack) like other platforms.
 665                  */
 666                 current->mm->start_brk = datapos + data_len + bss_len;
 667                 current->mm->brk = (current->mm->start_brk + 3) & ~3;
 668                 current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len;
 669         }
 670
 671         if (flags & FLAT_FLAG_KTRACE)
 672                 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
 673                         id ? "Lib" : "Load", bprm->filename,
 674                         (int) start_code, (int) end_code,
 675                         (int) datapos,
 676                         (int) (datapos + data_len),
 677                         (int) (datapos + data_len),
 678                         (int) (((datapos + data_len + bss_len) + 3) & ~3));
 679
 680         text_len -= sizeof(struct flat_hdr); /* the real code len */
 681
 682         /* Store the current module values into the global library structure */
 683         libinfo->lib_list[id].start_code = start_code;
 684         libinfo->lib_list[id].start_data = datapos;
 685         libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
 686         libinfo->lib_list[id].text_len = text_len;
 687         libinfo->lib_list[id].loaded = 1;
 688         libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 689         libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
 690
 691         /*
 692          * We just load the allocations into some temporary memory to
 693          * help simplify all this mumbo jumbo
 694          *
 695          * We've got two different sections of relocation entries.
 696          * The first is the GOT which resides at the begining of the data segment
 697          * and is terminated with a -1.  This one can be relocated in place.
 698          * The second is the extra relocation entries tacked after the image's
 699          * data segment. These require a little more processing as the entry is
 700          * really an offset into the image which contains an offset into the
 701          * image.
 702          */
 703         if (flags & FLAT_FLAG_GOTPIC) {
 704                 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
 705                         unsigned long addr;
 706                         if (*rp) {
 707                                 addr = calc_reloc(*rp, libinfo, id, 0);
 708                                 if (addr == RELOC_FAILED) {
 709                                         ret = -ENOEXEC;
 710                                         goto err;
 711                                 }
 712                                 *rp = addr;
 713                         }
 714                 }
 715         }
 716
 717         /*
 718          * Now run through the relocation entries.
 719          * We've got to be careful here as C++ produces relocatable zero
 720          * entries in the constructor and destructor tables which are then
 721          * tested for being not zero (which will always occur unless we're
 722          * based from address zero).  This causes an endless loop as __start
 723          * is at zero.  The solution used is to not relocate zero addresses.
 724          * This has the negative side effect of not allowing a global data
 725          * reference to be statically initialised to _stext (I've moved
 726          * __start to address 4 so that is okay).
 727          */
 728         if (rev > OLD_FLAT_VERSION) {
 729                 for (i=0; i < relocs; i++) {
 730                         unsigned long addr, relval;
 731
 732                         /* Get the address of the pointer to be
 733                            relocated (of course, the address has to be
 734                            relocated first).  */
 735                         relval = ntohl(reloc[i]);
 736                         addr = flat_get_relocate_addr(relval);
 737                         rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
 738                         if (rp == (unsigned long *)RELOC_FAILED) {
 739                                 ret = -ENOEXEC;
 740                                 goto err;
 741                         }
 742
 743                         /* Get the pointer's value.  */
 744                         addr = flat_get_addr_from_rp(rp, relval, flags);
 745                         if (addr != 0) {
 746                                 /*
 747                                  * Do the relocation.  PIC relocs in the data section are
 748                                  * already in target order
 749                                  */
 750                                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
 751                                         addr = ntohl(addr);
 752                                 addr = calc_reloc(addr, libinfo, id, 0);
 753                                 if (addr == RELOC_FAILED) {
 754                                         ret = -ENOEXEC;
 755                                         goto err;
 756                                 }
 757
 758                                 /* Write back the relocated pointer.  */
 759                                 flat_put_addr_at_rp(rp, addr, relval);
 760                         }
 761                 }
 762         } else {
 763                 for (i=0; i < relocs; i++)
 764                         old_reloc(ntohl(reloc[i]));
 765         }
 766
 767         flush_icache_range(start_code, end_code);
 768
 769         /* zero the BSS,  BRK and stack areas */
 770         memset((void*)(datapos + data_len), 0, bss_len +
 771                         (memp + ksize((void *) memp) - stack_len -      /* end brk */
 772                         libinfo->lib_list[id].start_brk) +              /* start brk */
 773                         stack_len);
 774
 775         return 0;
 776 err:
 777         return ret;
 778 }
 779
 780
 781 /****************************************************************************/
 782 #ifdef CONFIG_BINFMT_SHARED_FLAT
 783
 784 /*
 785  * Load a shared library into memory.  The library gets its own data
 786  * segment (including bss) but not argv/argc/environ.
 787  */
 788
 789 static int load_flat_shared_library(int id, struct lib_info *libs)
 790 {
 791         struct linux_binprm bprm;
 792         int res;
 793         char buf[16];
 794
 795         /* Create the file name */
 796         sprintf(buf, "/lib/lib%d.so", id);
 797
 798         /* Open the file up */
 799         bprm.filename = buf;
 800         bprm.file = open_exec(bprm.filename);
 801         res = PTR_ERR(bprm.file);
 802         if (IS_ERR(bprm.file))
 803                 return res;
 804
 805         res = prepare_binprm(&bprm);
 806
 807         if (res <= (unsigned long)-4096)
 808                 res = load_flat_file(&bprm, libs, id, NULL);
 809         if (bprm.file) {
 810                 allow_write_access(bprm.file);
 811                 fput(bprm.file);
 812                 bprm.file = NULL;
 813         }
 814         return(res);
 815 }
 816
 817 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 818 /****************************************************************************/
 819
 820 /*
 821  * These are the functions used to load flat style executables and shared
 822  * libraries.  There is no binary dependent code anywhere else.
 823  */
 824
 825 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 826 {
 827         struct lib_info libinfo;
 828         unsigned long p = bprm->p;
 829         unsigned long stack_len;
 830         unsigned long start_addr;
 831         unsigned long *sp;
 832         int res;
 833         int i, j;
 834
 835         memset(&libinfo, 0, sizeof(libinfo));
 836         /*
 837          * We have to add the size of our arguments to our stack size
 838          * otherwise it's too easy for users to create stack overflows
 839          * by passing in a huge argument list.  And yes,  we have to be
 840          * pedantic and include space for the argv/envp array as it may have
 841          * a lot of entries.
 842          */
 843 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
 844         stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
 845         stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
 846         stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
 847
 848
 849         res = load_flat_file(bprm, &libinfo, 0, &stack_len);
 850         if (res > (unsigned long)-4096)
 851                 return res;
 852
 853         /* Update data segment pointers for all libraries */
 854         for (i=0; i<MAX_SHARED_LIBS; i++)
 855                 if (libinfo.lib_list[i].loaded)
 856                         for (j=0; j<MAX_SHARED_LIBS; j++)
 857                                 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
 858                                         (libinfo.lib_list[j].loaded)?
 859                                                 libinfo.lib_list[j].start_data:UNLOADED_LIB;
 860
 861         compute_creds(bprm);
 862         current->flags &= ~PF_FORKNOEXEC;
 863
 864         set_binfmt(&flat_format);
 865
 866         p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
 867         DBG_FLT("p=%x\n", (int)p);
 868
 869         /* copy the arg pages onto the stack, this could be more efficient :-) */
 870         for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
 871                 * (char *) --p =
 872                         ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
 873
 874         sp = (unsigned long *) create_flat_tables(p, bprm);
 875
 876         /* Fake some return addresses to ensure the call chain will
 877          * initialise library in order for us.  We are required to call
 878          * lib 1 first, then 2, ... and finally the main program (id 0).
 879          */
 880         start_addr = libinfo.lib_list[0].entry;
 881
 882 #ifdef CONFIG_BINFMT_SHARED_FLAT
 883         for (i = MAX_SHARED_LIBS-1; i>0; i--) {
 884                 if (libinfo.lib_list[i].loaded) {
 885                         /* Push previos first to call address */
 886                         --sp;   put_user(start_addr, sp);
 887                         start_addr = libinfo.lib_list[i].entry;
 888                 }
 889         }
 890 #endif
 891
 892         /* Stash our initial stack pointer into the mm structure */
 893         current->mm->start_stack = (unsigned long )sp;
 894
 895
 896         DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
 897                 (int)regs, (int)start_addr, (int)current->mm->start_stack);
 898
 899         start_thread(regs, start_addr, current->mm->start_stack);
 900
 901         if (current->ptrace & PT_PTRACED)
 902                 send_sig(SIGTRAP, current, 0);
 903
 904         return 0;
 905 }
 906
 907 /****************************************************************************/
 908
 909 static int __init init_flat_binfmt(void)
 910 {
 911         return register_binfmt(&flat_format);
 912 }
 913
 914 static void __exit exit_flat_binfmt(void)
 915 {
 916         unregister_binfmt(&flat_format);
 917 }
 918
 919 /****************************************************************************/
 920
 921 core_initcall(init_flat_binfmt);
 922 module_exit(exit_flat_binfmt);
 923
 924 /****************************************************************************/