fs/binfmt_flat.c

   1 /****************************************************************************/
   2 /*
   3  *  linux/fs/binfmt_flat.c
   4  *
   5  *      Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
   6  *      Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
   7  *      Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
   8  *      Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
   9  *  based heavily on:
  10  *
  11  *  linux/fs/binfmt_aout.c:
  12  *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
  13  *  linux/fs/binfmt_flat.c for 2.0 kernel
  14  *          Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
  15  *      JAN/99 -- coded full program relocation (gerg@snapgear.com)
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/kernel.h>
  20 #include <linux/sched.h>
  21 #include <linux/mm.h>
  22 #include <linux/mman.h>
  23 #include <linux/a.out.h>
  24 #include <linux/errno.h>
  25 #include <linux/signal.h>
  26 #include <linux/string.h>
  27 #include <linux/fs.h>
  28 #include <linux/file.h>
  29 #include <linux/stat.h>
  30 #include <linux/fcntl.h>
  31 #include <linux/ptrace.h>
  32 #include <linux/user.h>
  33 #include <linux/slab.h>
  34 #include <linux/binfmts.h>
  35 #include <linux/personality.h>
  36 #include <linux/init.h>
  37 #include <linux/flat.h>
  38 #include <linux/syscalls.h>
  39
  40 #include <asm/byteorder.h>
  41 #include <asm/system.h>
  42 #include <asm/uaccess.h>
  43 #include <asm/unaligned.h>
  44 #include <asm/cacheflush.h>
  45
  46 /****************************************************************************/
  47
  48 #if 0
  49 #define DEBUG 1
  50 #endif
  51
  52 #ifdef DEBUG
  53 #define DBG_FLT(a...)   printk(a)
  54 #else
  55 #define DBG_FLT(a...)
  56 #endif
  57
  58 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  59 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  60
  61 struct lib_info {
  62         struct {
  63                 unsigned long start_code;               /* Start of text segment */
  64                 unsigned long start_data;               /* Start of data segment */
  65                 unsigned long start_brk;                /* End of data segment */
  66                 unsigned long text_len;                 /* Length of text segment */
  67                 unsigned long entry;                    /* Start address for this module */
  68                 unsigned long build_date;               /* When this one was compiled */
  69                 short loaded;                           /* Has this library been loaded? */
  70         } lib_list[MAX_SHARED_LIBS];
  71 };
  72
  73 #ifdef CONFIG_BINFMT_SHARED_FLAT
  74 static int load_flat_shared_library(int id, struct lib_info *p);
  75 #endif
  76
  77 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
  78 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file);
  79
  80 static struct linux_binfmt flat_format = {
  81         .module         = THIS_MODULE,
  82         .load_binary    = load_flat_binary,
  83         .core_dump      = flat_core_dump,
  84         .min_coredump   = PAGE_SIZE
  85 };
  86
  87 /****************************************************************************/
  88 /*
  89  * Routine writes a core dump image in the current directory.
  90  * Currently only a stub-function.
  91  */
  92
  93 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file)
  94 {
  95         printk("Process %s:%d received signr %d and should have core dumped\n",
  96                         current->comm, current->pid, (int) signr);
  97         return(1);
  98 }
  99
 100 /****************************************************************************/
 101 /*
 102  * create_flat_tables() parses the env- and arg-strings in new user
 103  * memory and creates the pointer tables from them, and puts their
 104  * addresses on the "stack", returning the new stack pointer value.
 105  */
 106
 107 static unsigned long create_flat_tables(
 108         unsigned long pp,
 109         struct linux_binprm * bprm)
 110 {
 111         unsigned long *argv,*envp;
 112         unsigned long * sp;
 113         char * p = (char*)pp;
 114         int argc = bprm->argc;
 115         int envc = bprm->envc;
 116         char dummy;
 117
 118         sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p);
 119
 120         sp -= envc+1;
 121         envp = sp;
 122         sp -= argc+1;
 123         argv = sp;
 124
 125         flat_stack_align(sp);
 126         if (flat_argvp_envp_on_stack()) {
 127                 --sp; put_user((unsigned long) envp, sp);
 128                 --sp; put_user((unsigned long) argv, sp);
 129         }
 130
 131         put_user(argc,--sp);
 132         current->mm->arg_start = (unsigned long) p;
 133         while (argc-->0) {
 134                 put_user((unsigned long) p, argv++);
 135                 do {
 136                         get_user(dummy, p); p++;
 137                 } while (dummy);
 138         }
 139         put_user((unsigned long) NULL, argv);
 140         current->mm->arg_end = current->mm->env_start = (unsigned long) p;
 141         while (envc-->0) {
 142                 put_user((unsigned long)p, envp); envp++;
 143                 do {
 144                         get_user(dummy, p); p++;
 145                 } while (dummy);
 146         }
 147         put_user((unsigned long) NULL, envp);
 148         current->mm->env_end = (unsigned long) p;
 149         return (unsigned long)sp;
 150 }
 151
 152 /****************************************************************************/
 153
 154 #ifdef CONFIG_BINFMT_ZFLAT
 155
 156 #include <linux/zlib.h>
 157
 158 #define LBUFSIZE        4000
 159
 160 /* gzip flag byte */
 161 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 162 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 163 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 164 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 165 #define COMMENT      0x10 /* bit 4 set: file comment present */
 166 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 167 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 168
 169 static int decompress_exec(
 170         struct linux_binprm *bprm,
 171         unsigned long offset,
 172         char *dst,
 173         long len,
 174         int fd)
 175 {
 176         unsigned char *buf;
 177         z_stream strm;
 178         loff_t fpos;
 179         int ret, retval;
 180
 181         DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
 182
 183         memset(&strm, 0, sizeof(strm));
 184         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 185         if (strm.workspace == NULL) {
 186                 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
 187                 return -ENOMEM;
 188         }
 189         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 190         if (buf == NULL) {
 191                 DBG_FLT("binfmt_flat: no memory for read buffer\n");
 192                 retval = -ENOMEM;
 193                 goto out_free;
 194         }
 195
 196         /* Read in first chunk of data and parse gzip header. */
 197         fpos = offset;
 198         ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 199
 200         strm.next_in = buf;
 201         strm.avail_in = ret;
 202         strm.total_in = 0;
 203
 204         retval = -ENOEXEC;
 205
 206         /* Check minimum size -- gzip header */
 207         if (ret < 10) {
 208                 DBG_FLT("binfmt_flat: file too small?\n");
 209                 goto out_free_buf;
 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                 goto out_free_buf;
 216         }
 217
 218         /* Check gzip method */
 219         if (buf[2] != 8) {
 220                 DBG_FLT("binfmt_flat: unknown compression method?\n");
 221                 goto out_free_buf;
 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                 goto out_free_buf;
 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                         goto out_free_buf;
 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                         goto out_free_buf;
 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                         goto out_free_buf;
 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                 goto out_free_buf;
 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                 goto out_zlib;
 284         }
 285
 286         retval = 0;
 287 out_zlib:
 288         zlib_inflateEnd(&strm);
 289 out_free_buf:
 290         kfree(buf);
 291 out_free:
 292         kfree(strm.workspace);
 293 out:
 294         return retval;
 295 }
 296
 297 #endif /* CONFIG_BINFMT_ZFLAT */
 298
 299 /****************************************************************************/
 300
 301 static unsigned long
 302 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 303 {
 304         unsigned long addr;
 305         int id;
 306         unsigned long start_brk;
 307         unsigned long start_data;
 308         unsigned long text_len;
 309         unsigned long start_code;
 310
 311 #ifdef CONFIG_BINFMT_SHARED_FLAT
 312         if (r == 0)
 313                 id = curid;     /* Relocs of 0 are always self referring */
 314         else {
 315                 id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 316                 r &= 0x00ffffff;        /* Trim ID off here */
 317         }
 318         if (id >= MAX_SHARED_LIBS) {
 319                 printk("BINFMT_FLAT: reference 0x%x to shared library %d",
 320                                 (unsigned) r, id);
 321                 goto failed;
 322         }
 323         if (curid != id) {
 324                 if (internalp) {
 325                         printk("BINFMT_FLAT: reloc address 0x%x not in same module "
 326                                         "(%d != %d)", (unsigned) r, curid, id);
 327                         goto failed;
 328                 } else if ( ! p->lib_list[id].loaded &&
 329                                 load_flat_shared_library(id, p) > (unsigned long) -4096) {
 330                         printk("BINFMT_FLAT: failed to load library %d", id);
 331                         goto failed;
 332                 }
 333                 /* Check versioning information (i.e. time stamps) */
 334                 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
 335                                 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
 336                         printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
 337                         goto failed;
 338                 }
 339         }
 340 #else
 341         id = 0;
 342 #endif
 343
 344         start_brk = p->lib_list[id].start_brk;
 345         start_data = p->lib_list[id].start_data;
 346         start_code = p->lib_list[id].start_code;
 347         text_len = p->lib_list[id].text_len;
 348
 349         if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
 350                 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
 351                        (int) r,(int)(start_brk-start_code),(int)text_len);
 352                 goto failed;
 353         }
 354
 355         if (r < text_len)                       /* In text segment */
 356                 addr = r + start_code;
 357         else                                    /* In data segment */
 358                 addr = r - text_len + start_data;
 359
 360         /* Range checked already above so doing the range tests is redundant...*/
 361         return(addr);
 362
 363 failed:
 364         printk(", killing %s!\n", current->comm);
 365         send_sig(SIGSEGV, current, 0);
 366
 367         return RELOC_FAILED;
 368 }
 369
 370 /****************************************************************************/
 371
 372 void old_reloc(unsigned long rl)
 373 {
 374 #ifdef DEBUG
 375         char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 376 #endif
 377         flat_v2_reloc_t r;
 378         unsigned long *ptr;
 379
 380         r.value = rl;
 381 #if defined(CONFIG_COLDFIRE)
 382         ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
 383 #else
 384         ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
 385 #endif
 386
 387 #ifdef DEBUG
 388         printk("Relocation of variable at DATASEG+%x "
 389                 "(address %p, currently %x) into segment %s\n",
 390                 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
 391 #endif
 392
 393         switch (r.reloc.type) {
 394         case OLD_FLAT_RELOC_TYPE_TEXT:
 395                 *ptr += current->mm->start_code;
 396                 break;
 397         case OLD_FLAT_RELOC_TYPE_DATA:
 398                 *ptr += current->mm->start_data;
 399                 break;
 400         case OLD_FLAT_RELOC_TYPE_BSS:
 401                 *ptr += current->mm->end_data;
 402                 break;
 403         default:
 404                 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
 405                 break;
 406         }
 407
 408 #ifdef DEBUG
 409         printk("Relocation became %x\n", (int)*ptr);
 410 #endif
 411 }
 412
 413 /****************************************************************************/
 414
 415 static int load_flat_file(struct linux_binprm * bprm,
 416                 struct lib_info *libinfo, int id, unsigned long *extra_stack)
 417 {
 418         struct flat_hdr * hdr;
 419         unsigned long textpos = 0, datapos = 0, result;
 420         unsigned long realdatastart = 0;
 421         unsigned long text_len, data_len, bss_len, stack_len, flags;
 422         unsigned long memp = 0; /* for finding the brk area */
 423         unsigned long extra, rlim;
 424         unsigned long *reloc = 0, *rp;
 425         struct inode *inode;
 426         int i, rev, relocs = 0;
 427         loff_t fpos;
 428         unsigned long start_code, end_code;
 429         int ret;
 430
 431         hdr = ((struct flat_hdr *) bprm->buf);          /* exec-header */
 432         inode = bprm->file->f_dentry->d_inode;
 433
 434         text_len  = ntohl(hdr->data_start);
 435         data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 436         bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 437         stack_len = ntohl(hdr->stack_size);
 438         if (extra_stack) {
 439                 stack_len += *extra_stack;
 440                 *extra_stack = stack_len;
 441         }
 442         relocs    = ntohl(hdr->reloc_count);
 443         flags     = ntohl(hdr->flags);
 444         rev       = ntohl(hdr->rev);
 445
 446         if (strncmp(hdr->magic, "bFLT", 4)) {
 447                 /*
 448                  * because a lot of people do not manage to produce good
 449                  * flat binaries,  we leave this printk to help them realise
 450                  * the problem.  We only print the error if its not a script file
 451                  */
 452                 if (strncmp(hdr->magic, "#!", 2))
 453                         printk("BINFMT_FLAT: bad header magic\n");
 454                 ret = -ENOEXEC;
 455                 goto err;
 456         }
 457
 458         if (flags & FLAT_FLAG_KTRACE)
 459                 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
 460
 461         if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 462                 printk("BINFMT_FLAT: bad flat file version 0x%x (supported 0x%x and 0x%x)\n", rev, FLAT_VERSION, OLD_FLAT_VERSION);
 463                 ret = -ENOEXEC;
 464                 goto err;
 465         }
 466
 467         /* Don't allow old format executables to use shared libraries */
 468         if (rev == OLD_FLAT_VERSION && id != 0) {
 469                 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
 470                                 (int) FLAT_VERSION);
 471                 ret = -ENOEXEC;
 472                 goto err;
 473         }
 474
 475         /*
 476          * fix up the flags for the older format,  there were all kinds
 477          * of endian hacks,  this only works for the simple cases
 478          */
 479         if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 480                 flags = FLAT_FLAG_RAM;
 481
 482 #ifndef CONFIG_BINFMT_ZFLAT
 483         if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 484                 printk("Support for ZFLAT executables is not enabled.\n");
 485                 ret = -ENOEXEC;
 486                 goto err;
 487         }
 488 #endif
 489
 490         /*
 491          * Check initial limits. This avoids letting people circumvent
 492          * size limits imposed on them by creating programs with large
 493          * arrays in the data or bss.
 494          */
 495         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
 496         if (rlim >= RLIM_INFINITY)
 497                 rlim = ~0;
 498         if (data_len + bss_len > rlim) {
 499                 ret = -ENOMEM;
 500                 goto err;
 501         }
 502
 503         /* Flush all traces of the currently running executable */
 504         if (id == 0) {
 505                 result = flush_old_exec(bprm);
 506                 if (result) {
 507                         ret = result;
 508                         goto err;
 509                 }
 510
 511                 /* OK, This is the point of no return */
 512                 set_personality(PER_LINUX_32BIT);
 513         }
 514
 515         /*
 516          * calculate the extra space we need to map in
 517          */
 518         extra = max(bss_len + stack_len, relocs * sizeof(unsigned long));
 519
 520         /*
 521          * there are a couple of cases here,  the separate code/data
 522          * case,  and then the fully copied to RAM case which lumps
 523          * it all together.
 524          */
 525         if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
 526                 /*
 527                  * this should give us a ROM ptr,  but if it doesn't we don't
 528                  * really care
 529                  */
 530                 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
 531
 532                 down_write(&current->mm->mmap_sem);
 533                 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0);
 534                 up_write(&current->mm->mmap_sem);
 535                 if (!textpos  || textpos >= (unsigned long) -4096) {
 536                         if (!textpos)
 537                                 textpos = (unsigned long) -ENOMEM;
 538                         printk("Unable to mmap process text, errno %d\n", (int)-textpos);
 539                         ret = textpos;
 540                         goto err;
 541                 }
 542
 543                 down_write(&current->mm->mmap_sem);
 544                 realdatastart = do_mmap(0, 0, data_len + extra +
 545                                 MAX_SHARED_LIBS * sizeof(unsigned long),
 546                                 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
 547                 up_write(&current->mm->mmap_sem);
 548
 549                 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
 550                         if (!realdatastart)
 551                                 realdatastart = (unsigned long) -ENOMEM;
 552                         printk("Unable to allocate RAM for process data, errno %d\n",
 553                                         (int)-datapos);
 554                         do_munmap(current->mm, textpos, text_len);
 555                         ret = realdatastart;
 556                         goto err;
 557                 }
 558                 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
 559
 560                 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
 561                                 (int)(data_len + bss_len + stack_len), (int)datapos);
 562
 563                 fpos = ntohl(hdr->data_start);
 564 #ifdef CONFIG_BINFMT_ZFLAT
 565                 if (flags & FLAT_FLAG_GZDATA) {
 566                         result = decompress_exec(bprm, fpos, (char *) datapos,
 567                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 568                 } else
 569 #endif
 570                 {
 571                         result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 572                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 573                 }
 574                 if (result >= (unsigned long)-4096) {
 575                         printk("Unable to read data+bss, errno %d\n", (int)-result);
 576                         do_munmap(current->mm, textpos, text_len);
 577                         do_munmap(current->mm, realdatastart, data_len + extra);
 578                         ret = result;
 579                         goto err;
 580                 }
 581
 582                 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
 583                 memp = realdatastart;
 584
 585         } else {
 586
 587                 down_write(&current->mm->mmap_sem);
 588                 textpos = do_mmap(0, 0, text_len + data_len + extra +
 589                                         MAX_SHARED_LIBS * sizeof(unsigned long),
 590                                 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
 591                 up_write(&current->mm->mmap_sem);
 592                 if (!textpos  || textpos >= (unsigned long) -4096) {
 593                         if (!textpos)
 594                                 textpos = (unsigned long) -ENOMEM;
 595                         printk("Unable to allocate RAM for process text/data, errno %d\n",
 596                                         (int)-textpos);
 597                         ret = textpos;
 598                         goto err;
 599                 }
 600
 601                 realdatastart = textpos + ntohl(hdr->data_start);
 602                 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
 603                 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
 604                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 605                 memp = textpos;
 606
 607 #ifdef CONFIG_BINFMT_ZFLAT
 608                 /*
 609                  * load it all in and treat it like a RAM load from now on
 610                  */
 611                 if (flags & FLAT_FLAG_GZIP) {
 612                         result = decompress_exec(bprm, sizeof (struct flat_hdr),
 613                                          (((char *) textpos) + sizeof (struct flat_hdr)),
 614                                          (text_len + data_len + (relocs * sizeof(unsigned long))
 615                                                   - sizeof (struct flat_hdr)),
 616                                          0);
 617                         memmove((void *) datapos, (void *) realdatastart,
 618                                         data_len + (relocs * sizeof(unsigned long)));
 619                 } else if (flags & FLAT_FLAG_GZDATA) {
 620                         fpos = 0;
 621                         result = bprm->file->f_op->read(bprm->file,
 622                                         (char *) textpos, text_len, &fpos);
 623                         if (result < (unsigned long) -4096)
 624                                 result = decompress_exec(bprm, text_len, (char *) datapos,
 625                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 626                 }
 627                 else
 628 #endif
 629                 {
 630                         fpos = 0;
 631                         result = bprm->file->f_op->read(bprm->file,
 632                                         (char *) textpos, text_len, &fpos);
 633                         if (result < (unsigned long) -4096) {
 634                                 fpos = ntohl(hdr->data_start);
 635                                 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 636                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 637                         }
 638                 }
 639                 if (result >= (unsigned long)-4096) {
 640                         printk("Unable to read code+data+bss, errno %d\n",(int)-result);
 641                         do_munmap(current->mm, textpos, text_len + data_len + extra +
 642                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 643                         ret = result;
 644                         goto err;
 645                 }
 646         }
 647
 648         if (flags & FLAT_FLAG_KTRACE)
 649                 printk("Mapping is %x, Entry point is %x, data_start is %x\n",
 650                         (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
 651
 652         /* The main program needs a little extra setup in the task structure */
 653         start_code = textpos + sizeof (struct flat_hdr);
 654         end_code = textpos + text_len;
 655         if (id == 0) {
 656                 current->mm->start_code = start_code;
 657                 current->mm->end_code = end_code;
 658                 current->mm->start_data = datapos;
 659                 current->mm->end_data = datapos + data_len;
 660                 /*
 661                  * set up the brk stuff, uses any slack left in data/bss/stack
 662                  * allocation.  We put the brk after the bss (between the bss
 663                  * and stack) like other platforms.
 664                  */
 665                 current->mm->start_brk = datapos + data_len + bss_len;
 666                 current->mm->brk = (current->mm->start_brk + 3) & ~3;
 667                 current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len;
 668         }
 669
 670         if (flags & FLAT_FLAG_KTRACE)
 671                 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
 672                         id ? "Lib" : "Load", bprm->filename,
 673                         (int) start_code, (int) end_code,
 674                         (int) datapos,
 675                         (int) (datapos + data_len),
 676                         (int) (datapos + data_len),
 677                         (int) (((datapos + data_len + bss_len) + 3) & ~3));
 678
 679         text_len -= sizeof(struct flat_hdr); /* the real code len */
 680
 681         /* Store the current module values into the global library structure */
 682         libinfo->lib_list[id].start_code = start_code;
 683         libinfo->lib_list[id].start_data = datapos;
 684         libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
 685         libinfo->lib_list[id].text_len = text_len;
 686         libinfo->lib_list[id].loaded = 1;
 687         libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 688         libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
 689
 690         /*
 691          * We just load the allocations into some temporary memory to
 692          * help simplify all this mumbo jumbo
 693          *
 694          * We've got two different sections of relocation entries.
 695          * The first is the GOT which resides at the begining of the data segment
 696          * and is terminated with a -1.  This one can be relocated in place.
 697          * The second is the extra relocation entries tacked after the image's
 698          * data segment. These require a little more processing as the entry is
 699          * really an offset into the image which contains an offset into the
 700          * image.
 701          */
 702         if (flags & FLAT_FLAG_GOTPIC) {
 703                 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
 704                         unsigned long addr;
 705                         if (*rp) {
 706                                 addr = calc_reloc(*rp, libinfo, id, 0);
 707                                 if (addr == RELOC_FAILED) {
 708                                         ret = -ENOEXEC;
 709                                         goto err;
 710                                 }
 711                                 *rp = addr;
 712                         }
 713                 }
 714         }
 715
 716         /*
 717          * Now run through the relocation entries.
 718          * We've got to be careful here as C++ produces relocatable zero
 719          * entries in the constructor and destructor tables which are then
 720          * tested for being not zero (which will always occur unless we're
 721          * based from address zero).  This causes an endless loop as __start
 722          * is at zero.  The solution used is to not relocate zero addresses.
 723          * This has the negative side effect of not allowing a global data
 724          * reference to be statically initialised to _stext (I've moved
 725          * __start to address 4 so that is okay).
 726          */
 727         if (rev > OLD_FLAT_VERSION) {
 728                 for (i=0; i < relocs; i++) {
 729                         unsigned long addr, relval;
 730
 731                         /* Get the address of the pointer to be
 732                            relocated (of course, the address has to be
 733                            relocated first).  */
 734                         relval = ntohl(reloc[i]);
 735                         addr = flat_get_relocate_addr(relval);
 736                         rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
 737                         if (rp == (unsigned long *)RELOC_FAILED) {
 738                                 ret = -ENOEXEC;
 739                                 goto err;
 740                         }
 741
 742                         /* Get the pointer's value.  */
 743                         addr = flat_get_addr_from_rp(rp, relval, flags);
 744                         if (addr != 0) {
 745                                 /*
 746                                  * Do the relocation.  PIC relocs in the data section are
 747                                  * already in target order
 748                                  */
 749                                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
 750                                         addr = ntohl(addr);
 751                                 addr = calc_reloc(addr, libinfo, id, 0);
 752                                 if (addr == RELOC_FAILED) {
 753                                         ret = -ENOEXEC;
 754                                         goto err;
 755                                 }
 756
 757                                 /* Write back the relocated pointer.  */
 758                                 flat_put_addr_at_rp(rp, addr, relval);
 759                         }
 760                 }
 761         } else {
 762                 for (i=0; i < relocs; i++)
 763                         old_reloc(ntohl(reloc[i]));
 764         }
 765
 766         flush_icache_range(start_code, end_code);
 767
 768         /* zero the BSS,  BRK and stack areas */
 769         memset((void*)(datapos + data_len), 0, bss_len +
 770                         (memp + ksize((void *) memp) - stack_len -      /* end brk */
 771                         libinfo->lib_list[id].start_brk) +              /* start brk */
 772                         stack_len);
 773
 774         return 0;
 775 err:
 776         return ret;
 777 }
 778
 779
 780 /****************************************************************************/
 781 #ifdef CONFIG_BINFMT_SHARED_FLAT
 782
 783 /*
 784  * Load a shared library into memory.  The library gets its own data
 785  * segment (including bss) but not argv/argc/environ.
 786  */
 787
 788 static int load_flat_shared_library(int id, struct lib_info *libs)
 789 {
 790         struct linux_binprm bprm;
 791         int res;
 792         char buf[16];
 793
 794         /* Create the file name */
 795         sprintf(buf, "/lib/lib%d.so", id);
 796
 797         /* Open the file up */
 798         bprm.filename = buf;
 799         bprm.file = open_exec(bprm.filename);
 800         res = PTR_ERR(bprm.file);
 801         if (IS_ERR(bprm.file))
 802                 return res;
 803
 804         res = prepare_binprm(&bprm);
 805
 806         if (res <= (unsigned long)-4096)
 807                 res = load_flat_file(&bprm, libs, id, NULL);
 808         if (bprm.file) {
 809                 allow_write_access(bprm.file);
 810                 fput(bprm.file);
 811                 bprm.file = NULL;
 812         }
 813         return(res);
 814 }
 815
 816 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 817 /****************************************************************************/
 818
 819 /*
 820  * These are the functions used to load flat style executables and shared
 821  * libraries.  There is no binary dependent code anywhere else.
 822  */
 823
 824 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 825 {
 826         struct lib_info libinfo;
 827         unsigned long p = bprm->p;
 828         unsigned long stack_len;
 829         unsigned long start_addr;
 830         unsigned long *sp;
 831         int res;
 832         int i, j;
 833
 834         memset(&libinfo, 0, sizeof(libinfo));
 835         /*
 836          * We have to add the size of our arguments to our stack size
 837          * otherwise it's too easy for users to create stack overflows
 838          * by passing in a huge argument list.  And yes,  we have to be
 839          * pedantic and include space for the argv/envp array as it may have
 840          * a lot of entries.
 841          */
 842 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
 843         stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
 844         stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
 845         stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
 846
 847
 848         res = load_flat_file(bprm, &libinfo, 0, &stack_len);
 849         if (res > (unsigned long)-4096)
 850                 return res;
 851
 852         /* Update data segment pointers for all libraries */
 853         for (i=0; i<MAX_SHARED_LIBS; i++)
 854                 if (libinfo.lib_list[i].loaded)
 855                         for (j=0; j<MAX_SHARED_LIBS; j++)
 856                                 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
 857                                         (libinfo.lib_list[j].loaded)?
 858                                                 libinfo.lib_list[j].start_data:UNLOADED_LIB;
 859
 860         compute_creds(bprm);
 861         current->flags &= ~PF_FORKNOEXEC;
 862
 863         set_binfmt(&flat_format);
 864
 865         p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
 866         DBG_FLT("p=%x\n", (int)p);
 867
 868         /* copy the arg pages onto the stack, this could be more efficient :-) */
 869         for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
 870                 * (char *) --p =
 871                         ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
 872
 873         sp = (unsigned long *) create_flat_tables(p, bprm);
 874
 875         /* Fake some return addresses to ensure the call chain will
 876          * initialise library in order for us.  We are required to call
 877          * lib 1 first, then 2, ... and finally the main program (id 0).
 878          */
 879         start_addr = libinfo.lib_list[0].entry;
 880
 881 #ifdef CONFIG_BINFMT_SHARED_FLAT
 882         for (i = MAX_SHARED_LIBS-1; i>0; i--) {
 883                 if (libinfo.lib_list[i].loaded) {
 884                         /* Push previos first to call address */
 885                         --sp;   put_user(start_addr, sp);
 886                         start_addr = libinfo.lib_list[i].entry;
 887                 }
 888         }
 889 #endif
 890
 891         /* Stash our initial stack pointer into the mm structure */
 892         current->mm->start_stack = (unsigned long )sp;
 893
 894
 895         DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
 896                 (int)regs, (int)start_addr, (int)current->mm->start_stack);
 897
 898         start_thread(regs, start_addr, current->mm->start_stack);
 899
 900         if (current->ptrace & PT_PTRACED)
 901                 send_sig(SIGTRAP, current, 0);
 902
 903         return 0;
 904 }
 905
 906 /****************************************************************************/
 907
 908 static int __init init_flat_binfmt(void)
 909 {
 910         return register_binfmt(&flat_format);
 911 }
 912
 913 static void __exit exit_flat_binfmt(void)
 914 {
 915         unregister_binfmt(&flat_format);
 916 }
 917
 918 /****************************************************************************/
 919
 920 core_initcall(init_flat_binfmt);
 921 module_exit(exit_flat_binfmt);
 922
 923 /****************************************************************************/