fs/binfmt_flat.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /****************************************************************************/
   3 /*
   4  *  linux/fs/binfmt_flat.c
   5  *
   6  *      Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
   7  *      Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
   8  *      Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
   9  *      Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
  10  *  based heavily on:
  11  *
  12  *  linux/fs/binfmt_aout.c:
  13  *      Copyright (C) 1991, 1992, 1996  Linus Torvalds
  14  *  linux/fs/binfmt_flat.c for 2.0 kernel
  15  *          Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com>
  16  *      JAN/99 -- coded full program relocation (gerg@snapgear.com)
  17  */
  18
  19 #define pr_fmt(fmt)     KBUILD_MODNAME ": " fmt
  20
  21 #include <linux/kernel.h>
  22 #include <linux/sched.h>
  23 #include <linux/sched/task_stack.h>
  24 #include <linux/mm.h>
  25 #include <linux/mman.h>
  26 #include <linux/errno.h>
  27 #include <linux/signal.h>
  28 #include <linux/string.h>
  29 #include <linux/fs.h>
  30 #include <linux/file.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/uaccess.h>
  39 #include <linux/vmalloc.h>
  40
  41 #include <asm/byteorder.h>
  42 #include <asm/unaligned.h>
  43 #include <asm/cacheflush.h>
  44 #include <asm/page.h>
  45 #include <asm/flat.h>
  46
  47 #ifndef flat_get_relocate_addr
  48 #define flat_get_relocate_addr(rel)     (rel)
  49 #endif
  50
  51 /****************************************************************************/
  52
  53 /*
  54  * User data (data section and bss) needs to be aligned.
  55  * We pick 0x20 here because it is the max value elf2flt has always
  56  * used in producing FLAT files, and because it seems to be large
  57  * enough to make all the gcc alignment related tests happy.
  58  */
  59 #define FLAT_DATA_ALIGN (0x20)
  60
  61 /*
  62  * User data (stack) also needs to be aligned.
  63  * Here we can be a bit looser than the data sections since this
  64  * needs to only meet arch ABI requirements.
  65  */
  66 #define FLAT_STACK_ALIGN        max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
  67
  68 #define RELOC_FAILED 0xff00ff01         /* Relocation incorrect somewhere */
  69 #define UNLOADED_LIB 0x7ff000ff         /* Placeholder for unused library */
  70
  71 #ifdef CONFIG_BINFMT_SHARED_FLAT
  72 #define MAX_SHARED_LIBS                 (4)
  73 #else
  74 #define MAX_SHARED_LIBS                 (1)
  75 #endif
  76
  77 struct lib_info {
  78         struct {
  79                 unsigned long start_code;               /* Start of text segment */
  80                 unsigned long start_data;               /* Start of data segment */
  81                 unsigned long start_brk;                /* End of data segment */
  82                 unsigned long text_len;                 /* Length of text segment */
  83                 unsigned long entry;                    /* Start address for this module */
  84                 unsigned long build_date;               /* When this one was compiled */
  85                 bool loaded;                            /* Has this library been loaded? */
  86         } lib_list[MAX_SHARED_LIBS];
  87 };
  88
  89 #ifdef CONFIG_BINFMT_SHARED_FLAT
  90 static int load_flat_shared_library(int id, struct lib_info *p);
  91 #endif
  92
  93 static int load_flat_binary(struct linux_binprm *);
  94 static int flat_core_dump(struct coredump_params *cprm);
  95
  96 static struct linux_binfmt flat_format = {
  97         .module         = THIS_MODULE,
  98         .load_binary    = load_flat_binary,
  99         .core_dump      = flat_core_dump,
 100         .min_coredump   = PAGE_SIZE
 101 };
 102
 103 /****************************************************************************/
 104 /*
 105  * Routine writes a core dump image in the current directory.
 106  * Currently only a stub-function.
 107  */
 108
 109 static int flat_core_dump(struct coredump_params *cprm)
 110 {
 111         pr_warn("Process %s:%d received signr %d and should have core dumped\n",
 112                 current->comm, current->pid, cprm->siginfo->si_signo);
 113         return 1;
 114 }
 115
 116 /****************************************************************************/
 117 /*
 118  * create_flat_tables() parses the env- and arg-strings in new user
 119  * memory and creates the pointer tables from them, and puts their
 120  * addresses on the "stack", recording the new stack pointer value.
 121  */
 122
 123 static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)
 124 {
 125         char __user *p;
 126         unsigned long __user *sp;
 127         long i, len;
 128
 129         p = (char __user *)arg_start;
 130         sp = (unsigned long __user *)current->mm->start_stack;
 131
 132         sp -= bprm->envc + 1;
 133         sp -= bprm->argc + 1;
 134         if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK))
 135                 sp -= 2; /* argvp + envp */
 136         sp -= 1;  /* &argc */
 137
 138         current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
 139         sp = (unsigned long __user *)current->mm->start_stack;
 140
 141         if (put_user(bprm->argc, sp++))
 142                 return -EFAULT;
 143         if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
 144                 unsigned long argv, envp;
 145                 argv = (unsigned long)(sp + 2);
 146                 envp = (unsigned long)(sp + 2 + bprm->argc + 1);
 147                 if (put_user(argv, sp++) || put_user(envp, sp++))
 148                         return -EFAULT;
 149         }
 150
 151         current->mm->arg_start = (unsigned long)p;
 152         for (i = bprm->argc; i > 0; i--) {
 153                 if (put_user((unsigned long)p, sp++))
 154                         return -EFAULT;
 155                 len = strnlen_user(p, MAX_ARG_STRLEN);
 156                 if (!len || len > MAX_ARG_STRLEN)
 157                         return -EINVAL;
 158                 p += len;
 159         }
 160         if (put_user(0, sp++))
 161                 return -EFAULT;
 162         current->mm->arg_end = (unsigned long)p;
 163
 164         current->mm->env_start = (unsigned long) p;
 165         for (i = bprm->envc; i > 0; i--) {
 166                 if (put_user((unsigned long)p, sp++))
 167                         return -EFAULT;
 168                 len = strnlen_user(p, MAX_ARG_STRLEN);
 169                 if (!len || len > MAX_ARG_STRLEN)
 170                         return -EINVAL;
 171                 p += len;
 172         }
 173         if (put_user(0, sp++))
 174                 return -EFAULT;
 175         current->mm->env_end = (unsigned long)p;
 176
 177         return 0;
 178 }
 179
 180 /****************************************************************************/
 181
 182 #ifdef CONFIG_BINFMT_ZFLAT
 183
 184 #include <linux/zlib.h>
 185
 186 #define LBUFSIZE        4000
 187
 188 /* gzip flag byte */
 189 #define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */
 190 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
 191 #define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */
 192 #define ORIG_NAME    0x08 /* bit 3 set: original file name present */
 193 #define COMMENT      0x10 /* bit 4 set: file comment present */
 194 #define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */
 195 #define RESERVED     0xC0 /* bit 6,7:   reserved */
 196
 197 static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst,
 198                 long len, int fd)
 199 {
 200         unsigned char *buf;
 201         z_stream strm;
 202         int ret, retval;
 203
 204         pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
 205
 206         memset(&strm, 0, sizeof(strm));
 207         strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
 208         if (!strm.workspace)
 209                 return -ENOMEM;
 210
 211         buf = kmalloc(LBUFSIZE, GFP_KERNEL);
 212         if (!buf) {
 213                 retval = -ENOMEM;
 214                 goto out_free;
 215         }
 216
 217         /* Read in first chunk of data and parse gzip header. */
 218         ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
 219
 220         strm.next_in = buf;
 221         strm.avail_in = ret;
 222         strm.total_in = 0;
 223
 224         retval = -ENOEXEC;
 225
 226         /* Check minimum size -- gzip header */
 227         if (ret < 10) {
 228                 pr_debug("file too small?\n");
 229                 goto out_free_buf;
 230         }
 231
 232         /* Check gzip magic number */
 233         if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
 234                 pr_debug("unknown compression magic?\n");
 235                 goto out_free_buf;
 236         }
 237
 238         /* Check gzip method */
 239         if (buf[2] != 8) {
 240                 pr_debug("unknown compression method?\n");
 241                 goto out_free_buf;
 242         }
 243         /* Check gzip flags */
 244         if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
 245             (buf[3] & RESERVED)) {
 246                 pr_debug("unknown flags?\n");
 247                 goto out_free_buf;
 248         }
 249
 250         ret = 10;
 251         if (buf[3] & EXTRA_FIELD) {
 252                 ret += 2 + buf[10] + (buf[11] << 8);
 253                 if (unlikely(ret >= LBUFSIZE)) {
 254                         pr_debug("buffer overflow (EXTRA)?\n");
 255                         goto out_free_buf;
 256                 }
 257         }
 258         if (buf[3] & ORIG_NAME) {
 259                 while (ret < LBUFSIZE && buf[ret++] != 0)
 260                         ;
 261                 if (unlikely(ret == LBUFSIZE)) {
 262                         pr_debug("buffer overflow (ORIG_NAME)?\n");
 263                         goto out_free_buf;
 264                 }
 265         }
 266         if (buf[3] & COMMENT) {
 267                 while (ret < LBUFSIZE && buf[ret++] != 0)
 268                         ;
 269                 if (unlikely(ret == LBUFSIZE)) {
 270                         pr_debug("buffer overflow (COMMENT)?\n");
 271                         goto out_free_buf;
 272                 }
 273         }
 274
 275         strm.next_in += ret;
 276         strm.avail_in -= ret;
 277
 278         strm.next_out = dst;
 279         strm.avail_out = len;
 280         strm.total_out = 0;
 281
 282         if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
 283                 pr_debug("zlib init failed?\n");
 284                 goto out_free_buf;
 285         }
 286
 287         while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
 288                 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
 289                 if (ret <= 0)
 290                         break;
 291                 len -= ret;
 292
 293                 strm.next_in = buf;
 294                 strm.avail_in = ret;
 295                 strm.total_in = 0;
 296         }
 297
 298         if (ret < 0) {
 299                 pr_debug("decompression failed (%d), %s\n",
 300                         ret, strm.msg);
 301                 goto out_zlib;
 302         }
 303
 304         retval = 0;
 305 out_zlib:
 306         zlib_inflateEnd(&strm);
 307 out_free_buf:
 308         kfree(buf);
 309 out_free:
 310         kfree(strm.workspace);
 311         return retval;
 312 }
 313
 314 #endif /* CONFIG_BINFMT_ZFLAT */
 315
 316 /****************************************************************************/
 317
 318 static unsigned long
 319 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
 320 {
 321         unsigned long addr;
 322         int id;
 323         unsigned long start_brk;
 324         unsigned long start_data;
 325         unsigned long text_len;
 326         unsigned long start_code;
 327
 328 #ifdef CONFIG_BINFMT_SHARED_FLAT
 329         if (r == 0)
 330                 id = curid;     /* Relocs of 0 are always self referring */
 331         else {
 332                 id = (r >> 24) & 0xff;  /* Find ID for this reloc */
 333                 r &= 0x00ffffff;        /* Trim ID off here */
 334         }
 335         if (id >= MAX_SHARED_LIBS) {
 336                 pr_err("reference 0x%lx to shared library %d", r, id);
 337                 goto failed;
 338         }
 339         if (curid != id) {
 340                 if (internalp) {
 341                         pr_err("reloc address 0x%lx not in same module "
 342                                "(%d != %d)", r, curid, id);
 343                         goto failed;
 344                 } else if (!p->lib_list[id].loaded &&
 345                            load_flat_shared_library(id, p) < 0) {
 346                         pr_err("failed to load library %d", id);
 347                         goto failed;
 348                 }
 349                 /* Check versioning information (i.e. time stamps) */
 350                 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
 351                                 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
 352                         pr_err("library %d is younger than %d", id, curid);
 353                         goto failed;
 354                 }
 355         }
 356 #else
 357         id = 0;
 358 #endif
 359
 360         start_brk = p->lib_list[id].start_brk;
 361         start_data = p->lib_list[id].start_data;
 362         start_code = p->lib_list[id].start_code;
 363         text_len = p->lib_list[id].text_len;
 364
 365         if (r > start_brk - start_data + text_len) {
 366                 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
 367                        r, start_brk-start_data+text_len, text_len);
 368                 goto failed;
 369         }
 370
 371         if (r < text_len)                       /* In text segment */
 372                 addr = r + start_code;
 373         else                                    /* In data segment */
 374                 addr = r - text_len + start_data;
 375
 376         /* Range checked already above so doing the range tests is redundant...*/
 377         return addr;
 378
 379 failed:
 380         pr_cont(", killing %s!\n", current->comm);
 381         send_sig(SIGSEGV, current, 0);
 382
 383         return RELOC_FAILED;
 384 }
 385
 386 /****************************************************************************/
 387
 388 #ifdef CONFIG_BINFMT_FLAT_OLD
 389 static void old_reloc(unsigned long rl)
 390 {
 391         static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
 392         flat_v2_reloc_t r;
 393         unsigned long __user *ptr;
 394         unsigned long val;
 395
 396         r.value = rl;
 397 #if defined(CONFIG_COLDFIRE)
 398         ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
 399 #else
 400         ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
 401 #endif
 402         get_user(val, ptr);
 403
 404         pr_debug("Relocation of variable at DATASEG+%x "
 405                  "(address %p, currently %lx) into segment %s\n",
 406                  r.reloc.offset, ptr, val, segment[r.reloc.type]);
 407
 408         switch (r.reloc.type) {
 409         case OLD_FLAT_RELOC_TYPE_TEXT:
 410                 val += current->mm->start_code;
 411                 break;
 412         case OLD_FLAT_RELOC_TYPE_DATA:
 413                 val += current->mm->start_data;
 414                 break;
 415         case OLD_FLAT_RELOC_TYPE_BSS:
 416                 val += current->mm->end_data;
 417                 break;
 418         default:
 419                 pr_err("Unknown relocation type=%x\n", r.reloc.type);
 420                 break;
 421         }
 422         put_user(val, ptr);
 423
 424         pr_debug("Relocation became %lx\n", val);
 425 }
 426 #endif /* CONFIG_BINFMT_FLAT_OLD */
 427
 428 /****************************************************************************/
 429
 430 static int load_flat_file(struct linux_binprm *bprm,
 431                 struct lib_info *libinfo, int id, unsigned long *extra_stack)
 432 {
 433         struct flat_hdr *hdr;
 434         unsigned long textpos, datapos, realdatastart;
 435         u32 text_len, data_len, bss_len, stack_len, full_data, flags;
 436         unsigned long len, memp, memp_size, extra, rlim;
 437         __be32 __user *reloc;
 438         u32 __user *rp;
 439         int i, rev, relocs;
 440         loff_t fpos;
 441         unsigned long start_code, end_code;
 442         ssize_t result;
 443         int ret;
 444
 445         hdr = ((struct flat_hdr *) bprm->buf);          /* exec-header */
 446
 447         text_len  = ntohl(hdr->data_start);
 448         data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);
 449         bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
 450         stack_len = ntohl(hdr->stack_size);
 451         if (extra_stack) {
 452                 stack_len += *extra_stack;
 453                 *extra_stack = stack_len;
 454         }
 455         relocs    = ntohl(hdr->reloc_count);
 456         flags     = ntohl(hdr->flags);
 457         rev       = ntohl(hdr->rev);
 458         full_data = data_len + relocs * sizeof(unsigned long);
 459
 460         if (strncmp(hdr->magic, "bFLT", 4)) {
 461                 /*
 462                  * Previously, here was a printk to tell people
 463                  *   "BINFMT_FLAT: bad header magic".
 464                  * But for the kernel which also use ELF FD-PIC format, this
 465                  * error message is confusing.
 466                  * because a lot of people do not manage to produce good
 467                  */
 468                 ret = -ENOEXEC;
 469                 goto err;
 470         }
 471
 472         if (flags & FLAT_FLAG_KTRACE)
 473                 pr_info("Loading file: %s\n", bprm->filename);
 474
 475 #ifdef CONFIG_BINFMT_FLAT_OLD
 476         if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
 477                 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
 478                        rev, FLAT_VERSION, OLD_FLAT_VERSION);
 479                 ret = -ENOEXEC;
 480                 goto err;
 481         }
 482
 483         /* Don't allow old format executables to use shared libraries */
 484         if (rev == OLD_FLAT_VERSION && id != 0) {
 485                 pr_err("shared libraries are not available before rev 0x%lx\n",
 486                        FLAT_VERSION);
 487                 ret = -ENOEXEC;
 488                 goto err;
 489         }
 490
 491         /*
 492          * fix up the flags for the older format,  there were all kinds
 493          * of endian hacks,  this only works for the simple cases
 494          */
 495         if (rev == OLD_FLAT_VERSION &&
 496            (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
 497                 flags = FLAT_FLAG_RAM;
 498
 499 #else /* CONFIG_BINFMT_FLAT_OLD */
 500         if (rev != FLAT_VERSION) {
 501                 pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
 502                        rev, FLAT_VERSION);
 503                 ret = -ENOEXEC;
 504                 goto err;
 505         }
 506 #endif /* !CONFIG_BINFMT_FLAT_OLD */
 507
 508         /*
 509          * Make sure the header params are sane.
 510          * 28 bits (256 MB) is way more than reasonable in this case.
 511          * If some top bits are set we have probable binary corruption.
 512         */
 513         if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
 514                 pr_err("bad header\n");
 515                 ret = -ENOEXEC;
 516                 goto err;
 517         }
 518
 519 #ifndef CONFIG_BINFMT_ZFLAT
 520         if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
 521                 pr_err("Support for ZFLAT executables is not enabled.\n");
 522                 ret = -ENOEXEC;
 523                 goto err;
 524         }
 525 #endif
 526
 527         /*
 528          * Check initial limits. This avoids letting people circumvent
 529          * size limits imposed on them by creating programs with large
 530          * arrays in the data or bss.
 531          */
 532         rlim = rlimit(RLIMIT_DATA);
 533         if (rlim >= RLIM_INFINITY)
 534                 rlim = ~0;
 535         if (data_len + bss_len > rlim) {
 536                 ret = -ENOMEM;
 537                 goto err;
 538         }
 539
 540         /* Flush all traces of the currently running executable */
 541         if (id == 0) {
 542                 ret = begin_new_exec(bprm);
 543                 if (ret)
 544                         goto err;
 545
 546                 /* OK, This is the point of no return */
 547                 set_personality(PER_LINUX_32BIT);
 548                 setup_new_exec(bprm);
 549         }
 550
 551         /*
 552          * calculate the extra space we need to map in
 553          */
 554         extra = max_t(unsigned long, bss_len + stack_len,
 555                         relocs * sizeof(unsigned long));
 556
 557         /*
 558          * there are a couple of cases here,  the separate code/data
 559          * case,  and then the fully copied to RAM case which lumps
 560          * it all together.
 561          */
 562         if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
 563                 /*
 564                  * this should give us a ROM ptr,  but if it doesn't we don't
 565                  * really care
 566                  */
 567                 pr_debug("ROM mapping of file (we hope)\n");
 568
 569                 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
 570                                   MAP_PRIVATE|MAP_EXECUTABLE, 0);
 571                 if (!textpos || IS_ERR_VALUE(textpos)) {
 572                         ret = textpos;
 573                         if (!textpos)
 574                                 ret = -ENOMEM;
 575                         pr_err("Unable to mmap process text, errno %d\n", ret);
 576                         goto err;
 577                 }
 578
 579                 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
 580                 len = PAGE_ALIGN(len);
 581                 realdatastart = vm_mmap(NULL, 0, len,
 582                         PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
 583
 584                 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
 585                         ret = realdatastart;
 586                         if (!realdatastart)
 587                                 ret = -ENOMEM;
 588                         pr_err("Unable to allocate RAM for process data, "
 589                                "errno %d\n", ret);
 590                         vm_munmap(textpos, text_len);
 591                         goto err;
 592                 }
 593                 datapos = ALIGN(realdatastart +
 594                                 MAX_SHARED_LIBS * sizeof(unsigned long),
 595                                 FLAT_DATA_ALIGN);
 596
 597                 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
 598                          data_len + bss_len + stack_len, datapos);
 599
 600                 fpos = ntohl(hdr->data_start);
 601 #ifdef CONFIG_BINFMT_ZFLAT
 602                 if (flags & FLAT_FLAG_GZDATA) {
 603                         result = decompress_exec(bprm, fpos, (char *)datapos,
 604                                                  full_data, 0);
 605                 } else
 606 #endif
 607                 {
 608                         result = read_code(bprm->file, datapos, fpos,
 609                                         full_data);
 610                 }
 611                 if (IS_ERR_VALUE(result)) {
 612                         ret = result;
 613                         pr_err("Unable to read data+bss, errno %d\n", ret);
 614                         vm_munmap(textpos, text_len);
 615                         vm_munmap(realdatastart, len);
 616                         goto err;
 617                 }
 618
 619                 reloc = (__be32 __user *)
 620                         (datapos + (ntohl(hdr->reloc_start) - text_len));
 621                 memp = realdatastart;
 622                 memp_size = len;
 623         } else {
 624
 625                 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);
 626                 len = PAGE_ALIGN(len);
 627                 textpos = vm_mmap(NULL, 0, len,
 628                         PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
 629
 630                 if (!textpos || IS_ERR_VALUE(textpos)) {
 631                         ret = textpos;
 632                         if (!textpos)
 633                                 ret = -ENOMEM;
 634                         pr_err("Unable to allocate RAM for process text/data, "
 635                                "errno %d\n", ret);
 636                         goto err;
 637                 }
 638
 639                 realdatastart = textpos + ntohl(hdr->data_start);
 640                 datapos = ALIGN(realdatastart +
 641                                 MAX_SHARED_LIBS * sizeof(u32),
 642                                 FLAT_DATA_ALIGN);
 643
 644                 reloc = (__be32 __user *)
 645                         (datapos + (ntohl(hdr->reloc_start) - text_len));
 646                 memp = textpos;
 647                 memp_size = len;
 648 #ifdef CONFIG_BINFMT_ZFLAT
 649                 /*
 650                  * load it all in and treat it like a RAM load from now on
 651                  */
 652                 if (flags & FLAT_FLAG_GZIP) {
 653 #ifndef CONFIG_MMU
 654                         result = decompress_exec(bprm, sizeof(struct flat_hdr),
 655                                          (((char *)textpos) + sizeof(struct flat_hdr)),
 656                                          (text_len + full_data
 657                                                   - sizeof(struct flat_hdr)),
 658                                          0);
 659                         memmove((void *) datapos, (void *) realdatastart,
 660                                         full_data);
 661 #else
 662                         /*
 663                          * This is used on MMU systems mainly for testing.
 664                          * Let's use a kernel buffer to simplify things.
 665                          */
 666                         long unz_text_len = text_len - sizeof(struct flat_hdr);
 667                         long unz_len = unz_text_len + full_data;
 668                         char *unz_data = vmalloc(unz_len);
 669                         if (!unz_data) {
 670                                 result = -ENOMEM;
 671                         } else {
 672                                 result = decompress_exec(bprm, sizeof(struct flat_hdr),
 673                                                          unz_data, unz_len, 0);
 674                                 if (result == 0 &&
 675                                     (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
 676                                                   unz_data, unz_text_len) ||
 677                                      copy_to_user((void __user *)datapos,
 678                                                   unz_data + unz_text_len, full_data)))
 679                                         result = -EFAULT;
 680                                 vfree(unz_data);
 681                         }
 682 #endif
 683                 } else if (flags & FLAT_FLAG_GZDATA) {
 684                         result = read_code(bprm->file, textpos, 0, text_len);
 685                         if (!IS_ERR_VALUE(result)) {
 686 #ifndef CONFIG_MMU
 687                                 result = decompress_exec(bprm, text_len, (char *) datapos,
 688                                                  full_data, 0);
 689 #else
 690                                 char *unz_data = vmalloc(full_data);
 691                                 if (!unz_data) {
 692                                         result = -ENOMEM;
 693                                 } else {
 694                                         result = decompress_exec(bprm, text_len,
 695                                                        unz_data, full_data, 0);
 696                                         if (result == 0 &&
 697                                             copy_to_user((void __user *)datapos,
 698                                                          unz_data, full_data))
 699                                                 result = -EFAULT;
 700                                         vfree(unz_data);
 701                                 }
 702 #endif
 703                         }
 704                 } else
 705 #endif /* CONFIG_BINFMT_ZFLAT */
 706                 {
 707                         result = read_code(bprm->file, textpos, 0, text_len);
 708                         if (!IS_ERR_VALUE(result))
 709                                 result = read_code(bprm->file, datapos,
 710                                                    ntohl(hdr->data_start),
 711                                                    full_data);
 712                 }
 713                 if (IS_ERR_VALUE(result)) {
 714                         ret = result;
 715                         pr_err("Unable to read code+data+bss, errno %d\n", ret);
 716                         vm_munmap(textpos, text_len + data_len + extra +
 717                                 MAX_SHARED_LIBS * sizeof(u32));
 718                         goto err;
 719                 }
 720         }
 721
 722         start_code = textpos + sizeof(struct flat_hdr);
 723         end_code = textpos + text_len;
 724         text_len -= sizeof(struct flat_hdr); /* the real code len */
 725
 726         /* The main program needs a little extra setup in the task structure */
 727         if (id == 0) {
 728                 current->mm->start_code = start_code;
 729                 current->mm->end_code = end_code;
 730                 current->mm->start_data = datapos;
 731                 current->mm->end_data = datapos + data_len;
 732                 /*
 733                  * set up the brk stuff, uses any slack left in data/bss/stack
 734                  * allocation.  We put the brk after the bss (between the bss
 735                  * and stack) like other platforms.
 736                  * Userspace code relies on the stack pointer starting out at
 737                  * an address right at the end of a page.
 738                  */
 739                 current->mm->start_brk = datapos + data_len + bss_len;
 740                 current->mm->brk = (current->mm->start_brk + 3) & ~3;
 741 #ifndef CONFIG_MMU
 742                 current->mm->context.end_brk = memp + memp_size - stack_len;
 743 #endif
 744         }
 745
 746         if (flags & FLAT_FLAG_KTRACE) {
 747                 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
 748                         textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
 749                 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
 750                         id ? "Lib" : "Load", bprm->filename,
 751                         start_code, end_code, datapos, datapos + data_len,
 752                         datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
 753         }
 754
 755         /* Store the current module values into the global library structure */
 756         libinfo->lib_list[id].start_code = start_code;
 757         libinfo->lib_list[id].start_data = datapos;
 758         libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
 759         libinfo->lib_list[id].text_len = text_len;
 760         libinfo->lib_list[id].loaded = 1;
 761         libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
 762         libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
 763
 764         /*
 765          * We just load the allocations into some temporary memory to
 766          * help simplify all this mumbo jumbo
 767          *
 768          * We've got two different sections of relocation entries.
 769          * The first is the GOT which resides at the beginning of the data segment
 770          * and is terminated with a -1.  This one can be relocated in place.
 771          * The second is the extra relocation entries tacked after the image's
 772          * data segment. These require a little more processing as the entry is
 773          * really an offset into the image which contains an offset into the
 774          * image.
 775          */
 776         if (flags & FLAT_FLAG_GOTPIC) {
 777                 for (rp = (u32 __user *)datapos; ; rp++) {
 778                         u32 addr, rp_val;
 779                         if (get_user(rp_val, rp))
 780                                 return -EFAULT;
 781                         if (rp_val == 0xffffffff)
 782                                 break;
 783                         if (rp_val) {
 784                                 addr = calc_reloc(rp_val, libinfo, id, 0);
 785                                 if (addr == RELOC_FAILED) {
 786                                         ret = -ENOEXEC;
 787                                         goto err;
 788                                 }
 789                                 if (put_user(addr, rp))
 790                                         return -EFAULT;
 791                         }
 792                 }
 793         }
 794
 795         /*
 796          * Now run through the relocation entries.
 797          * We've got to be careful here as C++ produces relocatable zero
 798          * entries in the constructor and destructor tables which are then
 799          * tested for being not zero (which will always occur unless we're
 800          * based from address zero).  This causes an endless loop as __start
 801          * is at zero.  The solution used is to not relocate zero addresses.
 802          * This has the negative side effect of not allowing a global data
 803          * reference to be statically initialised to _stext (I've moved
 804          * __start to address 4 so that is okay).
 805          */
 806         if (rev > OLD_FLAT_VERSION) {
 807                 for (i = 0; i < relocs; i++) {
 808                         u32 addr, relval;
 809                         __be32 tmp;
 810
 811                         /*
 812                          * Get the address of the pointer to be
 813                          * relocated (of course, the address has to be
 814                          * relocated first).
 815                          */
 816                         if (get_user(tmp, reloc + i))
 817                                 return -EFAULT;
 818                         relval = ntohl(tmp);
 819                         addr = flat_get_relocate_addr(relval);
 820                         rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
 821                         if (rp == (u32 __user *)RELOC_FAILED) {
 822                                 ret = -ENOEXEC;
 823                                 goto err;
 824                         }
 825
 826                         /* Get the pointer's value.  */
 827                         ret = flat_get_addr_from_rp(rp, relval, flags, &addr);
 828                         if (unlikely(ret))
 829                                 goto err;
 830
 831                         if (addr != 0) {
 832                                 /*
 833                                  * Do the relocation.  PIC relocs in the data section are
 834                                  * already in target order
 835                                  */
 836                                 if ((flags & FLAT_FLAG_GOTPIC) == 0) {
 837                                         /*
 838                                          * Meh, the same value can have a different
 839                                          * byte order based on a flag..
 840                                          */
 841                                         addr = ntohl((__force __be32)addr);
 842                                 }
 843                                 addr = calc_reloc(addr, libinfo, id, 0);
 844                                 if (addr == RELOC_FAILED) {
 845                                         ret = -ENOEXEC;
 846                                         goto err;
 847                                 }
 848
 849                                 /* Write back the relocated pointer.  */
 850                                 ret = flat_put_addr_at_rp(rp, addr, relval);
 851                                 if (unlikely(ret))
 852                                         goto err;
 853                         }
 854                 }
 855 #ifdef CONFIG_BINFMT_FLAT_OLD
 856         } else {
 857                 for (i = 0; i < relocs; i++) {
 858                         __be32 relval;
 859                         if (get_user(relval, reloc + i))
 860                                 return -EFAULT;
 861                         old_reloc(ntohl(relval));
 862                 }
 863 #endif /* CONFIG_BINFMT_FLAT_OLD */
 864         }
 865
 866         flush_icache_user_range(start_code, end_code);
 867
 868         /* zero the BSS,  BRK and stack areas */
 869         if (clear_user((void __user *)(datapos + data_len), bss_len +
 870                        (memp + memp_size - stack_len -          /* end brk */
 871                        libinfo->lib_list[id].start_brk) +       /* start brk */
 872                        stack_len))
 873                 return -EFAULT;
 874
 875         return 0;
 876 err:
 877         return ret;
 878 }
 879
 880
 881 /****************************************************************************/
 882 #ifdef CONFIG_BINFMT_SHARED_FLAT
 883
 884 /*
 885  * Load a shared library into memory.  The library gets its own data
 886  * segment (including bss) but not argv/argc/environ.
 887  */
 888
 889 static int load_flat_shared_library(int id, struct lib_info *libs)
 890 {
 891         /*
 892          * This is a fake bprm struct; only the members "buf", "file" and
 893          * "filename" are actually used.
 894          */
 895         struct linux_binprm bprm;
 896         int res;
 897         char buf[16];
 898         loff_t pos = 0;
 899
 900         memset(&bprm, 0, sizeof(bprm));
 901
 902         /* Create the file name */
 903         sprintf(buf, "/lib/lib%d.so", id);
 904
 905         /* Open the file up */
 906         bprm.filename = buf;
 907         bprm.file = open_exec(bprm.filename);
 908         res = PTR_ERR(bprm.file);
 909         if (IS_ERR(bprm.file))
 910                 return res;
 911
 912         res = kernel_read(bprm.file, bprm.buf, BINPRM_BUF_SIZE, &pos);
 913
 914         if (res >= 0)
 915                 res = load_flat_file(&bprm, libs, id, NULL);
 916
 917         allow_write_access(bprm.file);
 918         fput(bprm.file);
 919
 920         return res;
 921 }
 922
 923 #endif /* CONFIG_BINFMT_SHARED_FLAT */
 924 /****************************************************************************/
 925
 926 /*
 927  * These are the functions used to load flat style executables and shared
 928  * libraries.  There is no binary dependent code anywhere else.
 929  */
 930
 931 static int load_flat_binary(struct linux_binprm *bprm)
 932 {
 933         struct lib_info libinfo;
 934         struct pt_regs *regs = current_pt_regs();
 935         unsigned long stack_len = 0;
 936         unsigned long start_addr;
 937         int res;
 938         int i, j;
 939
 940         memset(&libinfo, 0, sizeof(libinfo));
 941
 942         /*
 943          * We have to add the size of our arguments to our stack size
 944          * otherwise it's too easy for users to create stack overflows
 945          * by passing in a huge argument list.  And yes,  we have to be
 946          * pedantic and include space for the argv/envp array as it may have
 947          * a lot of entries.
 948          */
 949 #ifndef CONFIG_MMU
 950         stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
 951 #endif
 952         stack_len += (bprm->argc + 1) * sizeof(char *);   /* the argv array */
 953         stack_len += (bprm->envc + 1) * sizeof(char *);   /* the envp array */
 954         stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
 955
 956         res = load_flat_file(bprm, &libinfo, 0, &stack_len);
 957         if (res < 0)
 958                 return res;
 959
 960         /* Update data segment pointers for all libraries */
 961         for (i = 0; i < MAX_SHARED_LIBS; i++) {
 962                 if (!libinfo.lib_list[i].loaded)
 963                         continue;
 964                 for (j = 0; j < MAX_SHARED_LIBS; j++) {
 965                         unsigned long val = libinfo.lib_list[j].loaded ?
 966                                 libinfo.lib_list[j].start_data : UNLOADED_LIB;
 967                         unsigned long __user *p = (unsigned long __user *)
 968                                 libinfo.lib_list[i].start_data;
 969                         p -= j + 1;
 970                         if (put_user(val, p))
 971                                 return -EFAULT;
 972                 }
 973         }
 974
 975         set_binfmt(&flat_format);
 976
 977 #ifdef CONFIG_MMU
 978         res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
 979         if (!res)
 980                 res = create_flat_tables(bprm, bprm->p);
 981 #else
 982         /* Stash our initial stack pointer into the mm structure */
 983         current->mm->start_stack =
 984                 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
 985         pr_debug("sp=%lx\n", current->mm->start_stack);
 986
 987         /* copy the arg pages onto the stack */
 988         res = transfer_args_to_stack(bprm, &current->mm->start_stack);
 989         if (!res)
 990                 res = create_flat_tables(bprm, current->mm->start_stack);
 991 #endif
 992         if (res)
 993                 return res;
 994
 995         /* Fake some return addresses to ensure the call chain will
 996          * initialise library in order for us.  We are required to call
 997          * lib 1 first, then 2, ... and finally the main program (id 0).
 998          */
 999         start_addr = libinfo.lib_list[0].entry;
1000
1001 #ifdef CONFIG_BINFMT_SHARED_FLAT
1002         for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
1003                 if (libinfo.lib_list[i].loaded) {
1004                         /* Push previos first to call address */
1005                         unsigned long __user *sp;
1006                         current->mm->start_stack -= sizeof(unsigned long);
1007                         sp = (unsigned long __user *)current->mm->start_stack;
1008                         if (put_user(start_addr, sp))
1009                                 return -EFAULT;
1010                         start_addr = libinfo.lib_list[i].entry;
1011                 }
1012         }
1013 #endif
1014
1015 #ifdef FLAT_PLAT_INIT
1016         FLAT_PLAT_INIT(regs);
1017 #endif
1018
1019         finalize_exec(bprm);
1020         pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
1021                  regs, start_addr, current->mm->start_stack);
1022         start_thread(regs, start_addr, current->mm->start_stack);
1023
1024         return 0;
1025 }
1026
1027 /****************************************************************************/
1028
1029 static int __init init_flat_binfmt(void)
1030 {
1031         register_binfmt(&flat_format);
1032         return 0;
1033 }
1034 core_initcall(init_flat_binfmt);
1035
1036 /****************************************************************************/