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