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