fs/binfmt_flat.c

   1 /****************************************************************************/
   2 /*
   3  *  linux/fs/binfmt_flat.c
   4  *
   5  *      Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
   6  *      Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
   7  *      Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
   8  *      Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
   9  *  based heavily on:
  10  *
  11  *  linux/fs/binfmt_aout.c:
  12  *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
  13  *  linux/fs/binfmt_flat.c for 2.0 kernel
  14  *          Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
  15  *      JAN/99 -- coded full program relocation (gerg@snapgear.com)
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/kernel.h>
  20 #include <linux/sched.h>
  21 #include <linux/mm.h>
  22 #include <linux/mman.h>
  23 #include <linux/errno.h>
  24 #include <linux/signal.h>
  25 #include <linux/string.h>
  26 #include <linux/fs.h>
  27 #include <linux/file.h>
  28 #include <linux/stat.h>
  29 #include <linux/fcntl.h>
  30 #include <linux/ptrace.h>
  31 #include <linux/user.h>
  32 #include <linux/slab.h>
  33 #include <linux/binfmts.h>
  34 #include <linux/personality.h>
  35 #include <linux/init.h>
  36 #include <linux/flat.h>
  37 #include <linux/syscalls.h>
  38
  39 #include <asm/byteorder.h>
  40 #include <asm/system.h>
  41 #include <asm/uaccess.h>
  42 #include <asm/unaligned.h>
  43 #include <asm/cacheflush.h>
  44 #include <asm/page.h>
  45
  46 /****************************************************************************/
  47
  48 #if 0
  49 #define DEBUG 1
  50 #endif
  51
  52 #ifdef DEBUG
  53 #define DBG_FLT(a...)   printk(a)
  54 #else
  55 #define DBG_FLT(a...)
  56 #endif
  57
  58 /*
  59  * User data (stack, data section and bss) needs to be aligned
  60  * for the same reasons as SLAB memory is, and to the same amount.
  61  * Avoid duplicating architecture specific code by using the same
  62  * macro as with SLAB allocation:
  63  */
  64 #ifdef ARCH_SLAB_MINALIGN
  65 #define FLAT_DATA_ALIGN (ARCH_SLAB_MINALIGN)
  66 #else
  67 #define FLAT_DATA_ALIGN (sizeof(void *))
  68 #endif
  69
  70 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  71 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  72
  73 struct lib_info {
  74         struct {
  75                 unsigned long start_code;               /* Start of text segment */
  76                 unsigned long start_data;               /* Start of data segment */
  77                 unsigned long start_brk;                /* End of data segment */
  78                 unsigned long text_len;                 /* Length of text segment */
  79                 unsigned long entry;                    /* Start address for this module */
  80                 unsigned long build_date;               /* When this one was compiled */
  81                 short loaded;                           /* Has this library been loaded? */
  82         } lib_list[MAX_SHARED_LIBS];
  83 };
  84
  85 #ifdef CONFIG_BINFMT_SHARED_FLAT
  86 static int load_flat_shared_library(int id, struct lib_info *p);
  87 #endif
  88
  89 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
  90 static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
  91
  92 static struct linux_binfmt flat_format = {
  93         .module         = THIS_MODULE,
  94         .load_binary    = load_flat_binary,
  95         .core_dump      = flat_core_dump,
  96         .min_coredump   = PAGE_SIZE
  97 };
  98
  99 /****************************************************************************/
 100 /*
 101  * Routine writes a core dump image in the current directory.
 102  * Currently only a stub-function.
 103  */
 104
 105 static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
 106 {
 107         printk("Process %s:%d received signr %d and should have core dumped\n",
 108                         current->comm, current->pid, (int) signr);
 109         return(1);
 110 }
 111
 112 /****************************************************************************/
 113 /*
 114  * create_flat_tables() parses the env- and arg-strings in new user
 115  * memory and creates the pointer tables from them, and puts their
 116  * addresses on the "stack", returning the new stack pointer value.
 117  */
 118
 119 static unsigned long create_flat_tables(
 120         unsigned long pp,
 121         struct linux_binprm * bprm)
 122 {
 123         unsigned long *argv,*envp;
 124         unsigned long * sp;
 125         char * p = (char*)pp;
 126         int argc = bprm->argc;
 127         int envc = bprm->envc;
 128         char uninitialized_var(dummy);
 129
 130         sp = (unsigned long *)p;
 131         sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
 132         sp = (unsigned long *) ((unsigned long)sp & -FLAT_DATA_ALIGN);
 133         argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0);
 134         envp = argv + (argc + 1);
 135
 136         if (flat_argvp_envp_on_stack()) {
 137                 put_user((unsigned long) envp, sp + 2);
 138                 put_user((unsigned long) argv, sp + 1);
 139         }
 140
 141         put_user(argc, sp);
 142         current->mm->arg_start = (unsigned long) p;
 143         while (argc-->0) {
 144                 put_user((unsigned long) p, argv++);
 145                 do {
 146                         get_user(dummy, p); p++;
 147                 } while (dummy);
 148         }
 149         put_user((unsigned long) NULL, argv);
 150         current->mm->arg_end = current->mm->env_start = (unsigned long) p;
 151         while (envc-->0) {
 152                 put_user((unsigned long)p, envp); envp++;
 153                 do {
 154                         get_user(dummy, p); p++;
 155                 } while (dummy);
 156         }
 157         put_user((unsigned long) NULL, envp);
 158         current->mm->env_end = (unsigned long) p;
 159         return (unsigned long)sp;
 160 }
 161
 162 /****************************************************************************/
 163
 164 #ifdef CONFIG_BINFMT_ZFLAT
 165
 166 #include <linux/zlib.h>
 167
 168 #define LBUFSIZE        4000
 169
 170 /* gzip flag byte */
 171 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 172 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 173 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 174 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 175 #define COMMENT      0x10 /* bit 4 set: file comment present */
 176 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 177 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 178
 179 static int decompress_exec(
 180         struct linux_binprm *bprm,
 181         unsigned long offset,
 182         char *dst,
 183         long len,
 184         int fd)
 185 {
 186         unsigned char *buf;
 187         z_stream strm;
 188         loff_t fpos;
 189         int ret, retval;
 190
 191         DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
 192
 193         memset(&strm, 0, sizeof(strm));
 194         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 195         if (strm.workspace == NULL) {
 196                 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
 197                 return -ENOMEM;
 198         }
 199         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 200         if (buf == NULL) {
 201                 DBG_FLT("binfmt_flat: no memory for read buffer\n");
 202                 retval = -ENOMEM;
 203                 goto out_free;
 204         }
 205
 206         /* Read in first chunk of data and parse gzip header. */
 207         fpos = offset;
 208         ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 209
 210         strm.next_in = buf;
 211         strm.avail_in = ret;
 212         strm.total_in = 0;
 213
 214         retval = -ENOEXEC;
 215
 216         /* Check minimum size -- gzip header */
 217         if (ret < 10) {
 218                 DBG_FLT("binfmt_flat: file too small?\n");
 219                 goto out_free_buf;
 220         }
 221
 222         /* Check gzip magic number */
 223         if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 224                 DBG_FLT("binfmt_flat: unknown compression magic?\n");
 225                 goto out_free_buf;
 226         }
 227
 228         /* Check gzip method */
 229         if (buf[2] != 8) {
 230                 DBG_FLT("binfmt_flat: unknown compression method?\n");
 231                 goto out_free_buf;
 232         }
 233         /* Check gzip flags */
 234         if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 235             (buf[3] & RESERVED)) {
 236                 DBG_FLT("binfmt_flat: unknown flags?\n");
 237                 goto out_free_buf;
 238         }
 239
 240         ret = 10;
 241         if (buf[3] & EXTRA_FIELD) {
 242                 ret += 2 + buf[10] + (buf[11] << 8);
 243                 if (unlikely(LBUFSIZE <= ret)) {
 244                         DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
 245                         goto out_free_buf;
 246                 }
 247         }
 248         if (buf[3] & ORIG_NAME) {
 249                 while (ret < LBUFSIZE && buf[ret++] != 0)
 250                         ;
 251                 if (unlikely(LBUFSIZE == ret)) {
 252                         DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
 253                         goto out_free_buf;
 254                 }
 255         }
 256         if (buf[3] & COMMENT) {
 257                 while (ret < LBUFSIZE && buf[ret++] != 0)
 258                         ;
 259                 if (unlikely(LBUFSIZE == ret)) {
 260                         DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
 261                         goto out_free_buf;
 262                 }
 263         }
 264
 265         strm.next_in += ret;
 266         strm.avail_in -= ret;
 267
 268         strm.next_out = dst;
 269         strm.avail_out = len;
 270         strm.total_out = 0;
 271
 272         if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 273                 DBG_FLT("binfmt_flat: zlib init failed?\n");
 274                 goto out_free_buf;
 275         }
 276
 277         while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 278                 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
 279                 if (ret <= 0)
 280                         break;
 281                 len -= ret;
 282
 283                 strm.next_in = buf;
 284                 strm.avail_in = ret;
 285                 strm.total_in = 0;
 286         }
 287
 288         if (ret < 0) {
 289                 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
 290                         ret, strm.msg);
 291                 goto out_zlib;
 292         }
 293
 294         retval = 0;
 295 out_zlib:
 296         zlib_inflateEnd(&strm);
 297 out_free_buf:
 298         kfree(buf);
 299 out_free:
 300         kfree(strm.workspace);
 301         return retval;
 302 }
 303
 304 #endif /* CONFIG_BINFMT_ZFLAT */
 305
 306 /****************************************************************************/
 307
 308 static unsigned long
 309 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 310 {
 311         unsigned long addr;
 312         int id;
 313         unsigned long start_brk;
 314         unsigned long start_data;
 315         unsigned long text_len;
 316         unsigned long start_code;
 317
 318 #ifdef CONFIG_BINFMT_SHARED_FLAT
 319         if (r == 0)
 320                 id = curid;     /* Relocs of 0 are always self referring */
 321         else {
 322                 id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 323                 r &= 0x00ffffff;        /* Trim ID off here */
 324         }
 325         if (id >= MAX_SHARED_LIBS) {
 326                 printk("BINFMT_FLAT: reference 0x%x to shared library %d",
 327                                 (unsigned) r, id);
 328                 goto failed;
 329         }
 330         if (curid != id) {
 331                 if (internalp) {
 332                         printk("BINFMT_FLAT: reloc address 0x%x not in same module "
 333                                         "(%d != %d)", (unsigned) r, curid, id);
 334                         goto failed;
 335                 } else if ( ! p->lib_list[id].loaded &&
 336                                 IS_ERR_VALUE(load_flat_shared_library(id, p))) {
 337                         printk("BINFMT_FLAT: failed to load library %d", id);
 338                         goto failed;
 339                 }
 340                 /* Check versioning information (i.e. time stamps) */
 341                 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
 342                                 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
 343                         printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
 344                         goto failed;
 345                 }
 346         }
 347 #else
 348         id = 0;
 349 #endif
 350
 351         start_brk = p->lib_list[id].start_brk;
 352         start_data = p->lib_list[id].start_data;
 353         start_code = p->lib_list[id].start_code;
 354         text_len = p->lib_list[id].text_len;
 355
 356         if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
 357                 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
 358                        (int) r,(int)(start_brk-start_code),(int)text_len);
 359                 goto failed;
 360         }
 361
 362         if (r < text_len)                       /* In text segment */
 363                 addr = r + start_code;
 364         else                                    /* In data segment */
 365                 addr = r - text_len + start_data;
 366
 367         /* Range checked already above so doing the range tests is redundant...*/
 368         return(addr);
 369
 370 failed:
 371         printk(", killing %s!\n", current->comm);
 372         send_sig(SIGSEGV, current, 0);
 373
 374         return RELOC_FAILED;
 375 }
 376
 377 /****************************************************************************/
 378
 379 void old_reloc(unsigned long rl)
 380 {
 381 #ifdef DEBUG
 382         char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 383 #endif
 384         flat_v2_reloc_t r;
 385         unsigned long *ptr;
 386
 387         r.value = rl;
 388 #if defined(CONFIG_COLDFIRE)
 389         ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
 390 #else
 391         ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
 392 #endif
 393
 394 #ifdef DEBUG
 395         printk("Relocation of variable at DATASEG+%x "
 396                 "(address %p, currently %x) into segment %s\n",
 397                 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
 398 #endif
 399
 400         switch (r.reloc.type) {
 401         case OLD_FLAT_RELOC_TYPE_TEXT:
 402                 *ptr += current->mm->start_code;
 403                 break;
 404         case OLD_FLAT_RELOC_TYPE_DATA:
 405                 *ptr += current->mm->start_data;
 406                 break;
 407         case OLD_FLAT_RELOC_TYPE_BSS:
 408                 *ptr += current->mm->end_data;
 409                 break;
 410         default:
 411                 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
 412                 break;
 413         }
 414
 415 #ifdef DEBUG
 416         printk("Relocation became %x\n", (int)*ptr);
 417 #endif
 418 }
 419
 420 /****************************************************************************/
 421
 422 static int load_flat_file(struct linux_binprm * bprm,
 423                 struct lib_info *libinfo, int id, unsigned long *extra_stack)
 424 {
 425         struct flat_hdr * hdr;
 426         unsigned long textpos = 0, datapos = 0, result;
 427         unsigned long realdatastart = 0;
 428         unsigned long text_len, data_len, bss_len, stack_len, flags;
 429         unsigned long len, memp = 0;
 430         unsigned long memp_size, extra, rlim;
 431         unsigned long *reloc = 0, *rp;
 432         struct inode *inode;
 433         int i, rev, relocs = 0;
 434         loff_t fpos;
 435         unsigned long start_code, end_code;
 436         int ret;
 437
 438         hdr = ((struct flat_hdr *) bprm->buf);          /* exec-header */
 439         inode = bprm->file->f_path.dentry->d_inode;
 440
 441         text_len  = ntohl(hdr->data_start);
 442         data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 443         bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 444         stack_len = ntohl(hdr->stack_size);
 445         if (extra_stack) {
 446                 stack_len += *extra_stack;
 447                 *extra_stack = stack_len;
 448         }
 449         relocs    = ntohl(hdr->reloc_count);
 450         flags     = ntohl(hdr->flags);
 451         rev       = ntohl(hdr->rev);
 452
 453         if (strncmp(hdr->magic, "bFLT", 4)) {
 454                 /*
 455                  * Previously, here was a printk to tell people
 456                  *   "BINFMT_FLAT: bad header magic".
 457                  * But for the kernel which also use ELF FD-PIC format, this
 458                  * error message is confusing.
 459                  * because a lot of people do not manage to produce good
 460                  */
 461                 ret = -ENOEXEC;
 462                 goto err;
 463         }
 464
 465         if (flags & FLAT_FLAG_KTRACE)
 466                 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
 467
 468         if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 469                 printk("BINFMT_FLAT: bad flat file version 0x%x (supported "
 470                         "0x%lx and 0x%lx)\n",
 471                         rev, FLAT_VERSION, OLD_FLAT_VERSION);
 472                 ret = -ENOEXEC;
 473                 goto err;
 474         }
 475
 476         /* Don't allow old format executables to use shared libraries */
 477         if (rev == OLD_FLAT_VERSION && id != 0) {
 478                 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
 479                                 (int) FLAT_VERSION);
 480                 ret = -ENOEXEC;
 481                 goto err;
 482         }
 483
 484         /*
 485          * fix up the flags for the older format,  there were all kinds
 486          * of endian hacks,  this only works for the simple cases
 487          */
 488         if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
 489                 flags = FLAT_FLAG_RAM;
 490
 491 #ifndef CONFIG_BINFMT_ZFLAT
 492         if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 493                 printk("Support for ZFLAT executables is not enabled.\n");
 494                 ret = -ENOEXEC;
 495                 goto err;
 496         }
 497 #endif
 498
 499         /*
 500          * Check initial limits. This avoids letting people circumvent
 501          * size limits imposed on them by creating programs with large
 502          * arrays in the data or bss.
 503          */
 504         rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
 505         if (rlim >= RLIM_INFINITY)
 506                 rlim = ~0;
 507         if (data_len + bss_len > rlim) {
 508                 ret = -ENOMEM;
 509                 goto err;
 510         }
 511
 512         /* Flush all traces of the currently running executable */
 513         if (id == 0) {
 514                 result = flush_old_exec(bprm);
 515                 if (result) {
 516                         ret = result;
 517                         goto err;
 518                 }
 519
 520                 /* OK, This is the point of no return */
 521                 set_personality(PER_LINUX_32BIT);
 522                 setup_new_exec(bprm);
 523         }
 524
 525         /*
 526          * calculate the extra space we need to map in
 527          */
 528         extra = max_t(unsigned long, bss_len + stack_len,
 529                         relocs * sizeof(unsigned long));
 530
 531         /*
 532          * there are a couple of cases here,  the separate code/data
 533          * case,  and then the fully copied to RAM case which lumps
 534          * it all together.
 535          */
 536         if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
 537                 /*
 538                  * this should give us a ROM ptr,  but if it doesn't we don't
 539                  * really care
 540                  */
 541                 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
 542
 543                 down_write(&current->mm->mmap_sem);
 544                 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
 545                                   MAP_PRIVATE|MAP_EXECUTABLE, 0);
 546                 up_write(&current->mm->mmap_sem);
 547                 if (!textpos || IS_ERR_VALUE(textpos)) {
 548                         if (!textpos)
 549                                 textpos = (unsigned long) -ENOMEM;
 550                         printk("Unable to mmap process text, errno %d\n", (int)-textpos);
 551                         ret = textpos;
 552                         goto err;
 553                 }
 554
 555                 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
 556                 len = PAGE_ALIGN(len);
 557                 down_write(&current->mm->mmap_sem);
 558                 realdatastart = do_mmap(0, 0, len,
 559                         PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
 560                 up_write(&current->mm->mmap_sem);
 561
 562                 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
 563                         if (!realdatastart)
 564                                 realdatastart = (unsigned long) -ENOMEM;
 565                         printk("Unable to allocate RAM for process data, errno %d\n",
 566                                         (int)-realdatastart);
 567                         do_munmap(current->mm, textpos, text_len);
 568                         ret = realdatastart;
 569                         goto err;
 570                 }
 571                 datapos = ALIGN(realdatastart +
 572                                 MAX_SHARED_LIBS * sizeof(unsigned long),
 573                                 FLAT_DATA_ALIGN);
 574
 575                 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
 576                                 (int)(data_len + bss_len + stack_len), (int)datapos);
 577
 578                 fpos = ntohl(hdr->data_start);
 579 #ifdef CONFIG_BINFMT_ZFLAT
 580                 if (flags & FLAT_FLAG_GZDATA) {
 581                         result = decompress_exec(bprm, fpos, (char *) datapos,
 582                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 583                 } else
 584 #endif
 585                 {
 586                         result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 587                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 588                 }
 589                 if (IS_ERR_VALUE(result)) {
 590                         printk("Unable to read data+bss, errno %d\n", (int)-result);
 591                         do_munmap(current->mm, textpos, text_len);
 592                         do_munmap(current->mm, realdatastart, data_len + extra);
 593                         ret = result;
 594                         goto err;
 595                 }
 596
 597                 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
 598                 memp = realdatastart;
 599                 memp_size = len;
 600         } else {
 601
 602                 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
 603                 len = PAGE_ALIGN(len);
 604                 down_write(&current->mm->mmap_sem);
 605                 textpos = do_mmap(0, 0, len,
 606                         PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
 607                 up_write(&current->mm->mmap_sem);
 608
 609                 if (!textpos || IS_ERR_VALUE(textpos)) {
 610                         if (!textpos)
 611                                 textpos = (unsigned long) -ENOMEM;
 612                         printk("Unable to allocate RAM for process text/data, errno %d\n",
 613                                         (int)-textpos);
 614                         ret = textpos;
 615                         goto err;
 616                 }
 617
 618                 realdatastart = textpos + ntohl(hdr->data_start);
 619                 datapos = ALIGN(realdatastart +
 620                                 MAX_SHARED_LIBS * sizeof(unsigned long),
 621                                 FLAT_DATA_ALIGN);
 622
 623                 reloc = (unsigned long *)
 624                         (datapos + (ntohl(hdr->reloc_start) - text_len));
 625                 memp = textpos;
 626                 memp_size = len;
 627 #ifdef CONFIG_BINFMT_ZFLAT
 628                 /*
 629                  * load it all in and treat it like a RAM load from now on
 630                  */
 631                 if (flags & FLAT_FLAG_GZIP) {
 632                         result = decompress_exec(bprm, sizeof (struct flat_hdr),
 633                                          (((char *) textpos) + sizeof (struct flat_hdr)),
 634                                          (text_len + data_len + (relocs * sizeof(unsigned long))
 635                                                   - sizeof (struct flat_hdr)),
 636                                          0);
 637                         memmove((void *) datapos, (void *) realdatastart,
 638                                         data_len + (relocs * sizeof(unsigned long)));
 639                 } else if (flags & FLAT_FLAG_GZDATA) {
 640                         fpos = 0;
 641                         result = bprm->file->f_op->read(bprm->file,
 642                                         (char *) textpos, text_len, &fpos);
 643                         if (!IS_ERR_VALUE(result))
 644                                 result = decompress_exec(bprm, text_len, (char *) datapos,
 645                                                  data_len + (relocs * sizeof(unsigned long)), 0);
 646                 }
 647                 else
 648 #endif
 649                 {
 650                         fpos = 0;
 651                         result = bprm->file->f_op->read(bprm->file,
 652                                         (char *) textpos, text_len, &fpos);
 653                         if (!IS_ERR_VALUE(result)) {
 654                                 fpos = ntohl(hdr->data_start);
 655                                 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
 656                                         data_len + (relocs * sizeof(unsigned long)), &fpos);
 657                         }
 658                 }
 659                 if (IS_ERR_VALUE(result)) {
 660                         printk("Unable to read code+data+bss, errno %d\n",(int)-result);
 661                         do_munmap(current->mm, textpos, text_len + data_len + extra +
 662                                 MAX_SHARED_LIBS * sizeof(unsigned long));
 663                         ret = result;
 664                         goto err;
 665                 }
 666         }
 667
 668         if (flags & FLAT_FLAG_KTRACE)
 669                 printk("Mapping is %x, Entry point is %x, data_start is %x\n",
 670                         (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
 671
 672         /* The main program needs a little extra setup in the task structure */
 673         start_code = textpos + sizeof (struct flat_hdr);
 674         end_code = textpos + text_len;
 675         if (id == 0) {
 676                 current->mm->start_code = start_code;
 677                 current->mm->end_code = end_code;
 678                 current->mm->start_data = datapos;
 679                 current->mm->end_data = datapos + data_len;
 680                 /*
 681                  * set up the brk stuff, uses any slack left in data/bss/stack
 682                  * allocation.  We put the brk after the bss (between the bss
 683                  * and stack) like other platforms.
 684                  * Userspace code relies on the stack pointer starting out at
 685                  * an address right at the end of a page.
 686                  */
 687                 current->mm->start_brk = datapos + data_len + bss_len;
 688                 current->mm->brk = (current->mm->start_brk + 3) & ~3;
 689                 current->mm->context.end_brk = memp + memp_size - stack_len;
 690         }
 691
 692         if (flags & FLAT_FLAG_KTRACE)
 693                 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
 694                         id ? "Lib" : "Load", bprm->filename,
 695                         (int) start_code, (int) end_code,
 696                         (int) datapos,
 697                         (int) (datapos + data_len),
 698                         (int) (datapos + data_len),
 699                         (int) (((datapos + data_len + bss_len) + 3) & ~3));
 700
 701         text_len -= sizeof(struct flat_hdr); /* the real code len */
 702
 703         /* Store the current module values into the global library structure */
 704         libinfo->lib_list[id].start_code = start_code;
 705         libinfo->lib_list[id].start_data = datapos;
 706         libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
 707         libinfo->lib_list[id].text_len = text_len;
 708         libinfo->lib_list[id].loaded = 1;
 709         libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 710         libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
 711
 712         /*
 713          * We just load the allocations into some temporary memory to
 714          * help simplify all this mumbo jumbo
 715          *
 716          * We've got two different sections of relocation entries.
 717          * The first is the GOT which resides at the begining of the data segment
 718          * and is terminated with a -1.  This one can be relocated in place.
 719          * The second is the extra relocation entries tacked after the image's
 720          * data segment. These require a little more processing as the entry is
 721          * really an offset into the image which contains an offset into the
 722          * image.
 723          */
 724         if (flags & FLAT_FLAG_GOTPIC) {
 725                 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
 726                         unsigned long addr;
 727                         if (*rp) {
 728                                 addr = calc_reloc(*rp, libinfo, id, 0);
 729                                 if (addr == RELOC_FAILED) {
 730                                         ret = -ENOEXEC;
 731                                         goto err;
 732                                 }
 733                                 *rp = addr;
 734                         }
 735                 }
 736         }
 737
 738         /*
 739          * Now run through the relocation entries.
 740          * We've got to be careful here as C++ produces relocatable zero
 741          * entries in the constructor and destructor tables which are then
 742          * tested for being not zero (which will always occur unless we're
 743          * based from address zero).  This causes an endless loop as __start
 744          * is at zero.  The solution used is to not relocate zero addresses.
 745          * This has the negative side effect of not allowing a global data
 746          * reference to be statically initialised to _stext (I've moved
 747          * __start to address 4 so that is okay).
 748          */
 749         if (rev > OLD_FLAT_VERSION) {
 750                 unsigned long persistent = 0;
 751                 for (i=0; i < relocs; i++) {
 752                         unsigned long addr, relval;
 753
 754                         /* Get the address of the pointer to be
 755                            relocated (of course, the address has to be
 756                            relocated first).  */
 757                         relval = ntohl(reloc[i]);
 758                         if (flat_set_persistent (relval, &persistent))
 759                                 continue;
 760                         addr = flat_get_relocate_addr(relval);
 761                         rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
 762                         if (rp == (unsigned long *)RELOC_FAILED) {
 763                                 ret = -ENOEXEC;
 764                                 goto err;
 765                         }
 766
 767                         /* Get the pointer's value.  */
 768                         addr = flat_get_addr_from_rp(rp, relval, flags,
 769                                                         &persistent);
 770                         if (addr != 0) {
 771                                 /*
 772                                  * Do the relocation.  PIC relocs in the data section are
 773                                  * already in target order
 774                                  */
 775                                 if ((flags & FLAT_FLAG_GOTPIC) == 0)
 776                                         addr = ntohl(addr);
 777                                 addr = calc_reloc(addr, libinfo, id, 0);
 778                                 if (addr == RELOC_FAILED) {
 779                                         ret = -ENOEXEC;
 780                                         goto err;
 781                                 }
 782
 783                                 /* Write back the relocated pointer.  */
 784                                 flat_put_addr_at_rp(rp, addr, relval);
 785                         }
 786                 }
 787         } else {
 788                 for (i=0; i < relocs; i++)
 789                         old_reloc(ntohl(reloc[i]));
 790         }
 791
 792         flush_icache_range(start_code, end_code);
 793
 794         /* zero the BSS,  BRK and stack areas */
 795         memset((void*)(datapos + data_len), 0, bss_len +
 796                         (memp + memp_size - stack_len -         /* end brk */
 797                         libinfo->lib_list[id].start_brk) +      /* start brk */
 798                         stack_len);
 799
 800         return 0;
 801 err:
 802         return ret;
 803 }
 804
 805
 806 /****************************************************************************/
 807 #ifdef CONFIG_BINFMT_SHARED_FLAT
 808
 809 /*
 810  * Load a shared library into memory.  The library gets its own data
 811  * segment (including bss) but not argv/argc/environ.
 812  */
 813
 814 static int load_flat_shared_library(int id, struct lib_info *libs)
 815 {
 816         struct linux_binprm bprm;
 817         int res;
 818         char buf[16];
 819
 820         /* Create the file name */
 821         sprintf(buf, "/lib/lib%d.so", id);
 822
 823         /* Open the file up */
 824         bprm.filename = buf;
 825         bprm.file = open_exec(bprm.filename);
 826         res = PTR_ERR(bprm.file);
 827         if (IS_ERR(bprm.file))
 828                 return res;
 829
 830         bprm.cred = prepare_exec_creds();
 831         res = -ENOMEM;
 832         if (!bprm.cred)
 833                 goto out;
 834
 835         res = prepare_binprm(&bprm);
 836
 837         if (!IS_ERR_VALUE(res))
 838                 res = load_flat_file(&bprm, libs, id, NULL);
 839
 840         abort_creds(bprm.cred);
 841
 842 out:
 843         allow_write_access(bprm.file);
 844         fput(bprm.file);
 845
 846         return(res);
 847 }
 848
 849 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 850 /****************************************************************************/
 851
 852 /*
 853  * These are the functions used to load flat style executables and shared
 854  * libraries.  There is no binary dependent code anywhere else.
 855  */
 856
 857 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 858 {
 859         struct lib_info libinfo;
 860         unsigned long p = bprm->p;
 861         unsigned long stack_len;
 862         unsigned long start_addr;
 863         unsigned long *sp;
 864         int res;
 865         int i, j;
 866
 867         memset(&libinfo, 0, sizeof(libinfo));
 868         /*
 869          * We have to add the size of our arguments to our stack size
 870          * otherwise it's too easy for users to create stack overflows
 871          * by passing in a huge argument list.  And yes,  we have to be
 872          * pedantic and include space for the argv/envp array as it may have
 873          * a lot of entries.
 874          */
 875 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
 876         stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
 877         stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
 878         stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
 879         stack_len += FLAT_DATA_ALIGN - 1;  /* reserve for upcoming alignment */
 880
 881         res = load_flat_file(bprm, &libinfo, 0, &stack_len);
 882         if (IS_ERR_VALUE(res))
 883                 return res;
 884
 885         /* Update data segment pointers for all libraries */
 886         for (i=0; i<MAX_SHARED_LIBS; i++)
 887                 if (libinfo.lib_list[i].loaded)
 888                         for (j=0; j<MAX_SHARED_LIBS; j++)
 889                                 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
 890                                         (libinfo.lib_list[j].loaded)?
 891                                                 libinfo.lib_list[j].start_data:UNLOADED_LIB;
 892
 893         install_exec_creds(bprm);
 894         current->flags &= ~PF_FORKNOEXEC;
 895
 896         set_binfmt(&flat_format);
 897
 898         p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
 899         DBG_FLT("p=%x\n", (int)p);
 900
 901         /* copy the arg pages onto the stack, this could be more efficient :-) */
 902         for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
 903                 * (char *) --p =
 904                         ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
 905
 906         sp = (unsigned long *) create_flat_tables(p, bprm);
 907
 908         /* Fake some return addresses to ensure the call chain will
 909          * initialise library in order for us.  We are required to call
 910          * lib 1 first, then 2, ... and finally the main program (id 0).
 911          */
 912         start_addr = libinfo.lib_list[0].entry;
 913
 914 #ifdef CONFIG_BINFMT_SHARED_FLAT
 915         for (i = MAX_SHARED_LIBS-1; i>0; i--) {
 916                 if (libinfo.lib_list[i].loaded) {
 917                         /* Push previos first to call address */
 918                         --sp;   put_user(start_addr, sp);
 919                         start_addr = libinfo.lib_list[i].entry;
 920                 }
 921         }
 922 #endif
 923
 924         /* Stash our initial stack pointer into the mm structure */
 925         current->mm->start_stack = (unsigned long )sp;
 926
 927 #ifdef FLAT_PLAT_INIT
 928         FLAT_PLAT_INIT(regs);
 929 #endif
 930         DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
 931                 (int)regs, (int)start_addr, (int)current->mm->start_stack);
 932
 933         start_thread(regs, start_addr, current->mm->start_stack);
 934
 935         return 0;
 936 }
 937
 938 /****************************************************************************/
 939
 940 static int __init init_flat_binfmt(void)
 941 {
 942         return register_binfmt(&flat_format);
 943 }
 944
 945 /****************************************************************************/
 946
 947 core_initcall(init_flat_binfmt);
 948
 949 /****************************************************************************/