1 /****************************************************************************/ 2 /* 3 * linux/fs/binfmt_flat.c 4 * 5 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com> 6 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com> 7 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com> 8 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com> 9 * based heavily on: 10 * 11 * linux/fs/binfmt_aout.c: 12 * Copyright (C) 1991, 1992, 1996 Linus Torvalds 13 * linux/fs/binfmt_flat.c for 2.0 kernel 14 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com> 15 * JAN/99 -- coded full program relocation (gerg@snapgear.com) 16 */ 17 18 #include <linux/module.h> 19 #include <linux/kernel.h> 20 #include <linux/sched.h> 21 #include <linux/mm.h> 22 #include <linux/mman.h> 23 #include <linux/a.out.h> 24 #include <linux/errno.h> 25 #include <linux/signal.h> 26 #include <linux/string.h> 27 #include <linux/fs.h> 28 #include <linux/file.h> 29 #include <linux/stat.h> 30 #include <linux/fcntl.h> 31 #include <linux/ptrace.h> 32 #include <linux/user.h> 33 #include <linux/slab.h> 34 #include <linux/binfmts.h> 35 #include <linux/personality.h> 36 #include <linux/init.h> 37 #include <linux/flat.h> 38 #include <linux/syscalls.h> 39 40 #include <asm/byteorder.h> 41 #include <asm/system.h> 42 #include <asm/uaccess.h> 43 #include <asm/unaligned.h> 44 #include <asm/cacheflush.h> 45 46 /****************************************************************************/ 47 48 #if 0 49 #define DEBUG 1 50 #endif 51 52 #ifdef DEBUG 53 #define DBG_FLT(a...) printk(a) 54 #else 55 #define DBG_FLT(a...) 56 #endif 57 58 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 59 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 60 61 struct lib_info { 62 struct { 63 unsigned long start_code; /* Start of text segment */ 64 unsigned long start_data; /* Start of data segment */ 65 unsigned long start_brk; /* End of data segment */ 66 unsigned long text_len; /* Length of text segment */ 67 unsigned long entry; /* Start address for this module */ 68 unsigned long build_date; /* When this one was compiled */ 69 short loaded; /* Has this library been loaded? */ 70 } lib_list[MAX_SHARED_LIBS]; 71 }; 72 73 #ifdef CONFIG_BINFMT_SHARED_FLAT 74 static int load_flat_shared_library(int id, struct lib_info *p); 75 #endif 76 77 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs); 78 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file); 79 80 static struct linux_binfmt flat_format = { 81 .module = THIS_MODULE, 82 .load_binary = load_flat_binary, 83 .core_dump = flat_core_dump, 84 .min_coredump = PAGE_SIZE 85 }; 86 87 /****************************************************************************/ 88 /* 89 * Routine writes a core dump image in the current directory. 90 * Currently only a stub-function. 91 */ 92 93 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file) 94 { 95 printk("Process %s:%d received signr %d and should have core dumped\n", 96 current->comm, current->pid, (int) signr); 97 return(1); 98 } 99 100 /****************************************************************************/ 101 /* 102 * create_flat_tables() parses the env- and arg-strings in new user 103 * memory and creates the pointer tables from them, and puts their 104 * addresses on the "stack", returning the new stack pointer value. 105 */ 106 107 static unsigned long create_flat_tables( 108 unsigned long pp, 109 struct linux_binprm * bprm) 110 { 111 unsigned long *argv,*envp; 112 unsigned long * sp; 113 char * p = (char*)pp; 114 int argc = bprm->argc; 115 int envc = bprm->envc; 116 char dummy; 117 118 sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p); 119 120 sp -= envc+1; 121 envp = sp; 122 sp -= argc+1; 123 argv = sp; 124 125 flat_stack_align(sp); 126 if (flat_argvp_envp_on_stack()) { 127 --sp; put_user((unsigned long) envp, sp); 128 --sp; put_user((unsigned long) argv, sp); 129 } 130 131 put_user(argc,--sp); 132 current->mm->arg_start = (unsigned long) p; 133 while (argc-->0) { 134 put_user((unsigned long) p, argv++); 135 do { 136 get_user(dummy, p); p++; 137 } while (dummy); 138 } 139 put_user((unsigned long) NULL, argv); 140 current->mm->arg_end = current->mm->env_start = (unsigned long) p; 141 while (envc-->0) { 142 put_user((unsigned long)p, envp); envp++; 143 do { 144 get_user(dummy, p); p++; 145 } while (dummy); 146 } 147 put_user((unsigned long) NULL, envp); 148 current->mm->env_end = (unsigned long) p; 149 return (unsigned long)sp; 150 } 151 152 /****************************************************************************/ 153 154 #ifdef CONFIG_BINFMT_ZFLAT 155 156 #include <linux/zlib.h> 157 158 #define LBUFSIZE 4000 159 160 /* gzip flag byte */ 161 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 162 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 163 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 164 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 165 #define COMMENT 0x10 /* bit 4 set: file comment present */ 166 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 167 #define RESERVED 0xC0 /* bit 6,7: reserved */ 168 169 static int decompress_exec( 170 struct linux_binprm *bprm, 171 unsigned long offset, 172 char *dst, 173 long len, 174 int fd) 175 { 176 unsigned char *buf; 177 z_stream strm; 178 loff_t fpos; 179 int ret, retval; 180 181 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 182 183 memset(&strm, 0, sizeof(strm)); 184 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 185 if (strm.workspace == NULL) { 186 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 187 return -ENOMEM; 188 } 189 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 190 if (buf == NULL) { 191 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 192 retval = -ENOMEM; 193 goto out_free; 194 } 195 196 /* Read in first chunk of data and parse gzip header. */ 197 fpos = offset; 198 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 199 200 strm.next_in = buf; 201 strm.avail_in = ret; 202 strm.total_in = 0; 203 204 retval = -ENOEXEC; 205 206 /* Check minimum size -- gzip header */ 207 if (ret < 10) { 208 DBG_FLT("binfmt_flat: file too small?\n"); 209 goto out_free_buf; 210 } 211 212 /* Check gzip magic number */ 213 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 214 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 215 goto out_free_buf; 216 } 217 218 /* Check gzip method */ 219 if (buf[2] != 8) { 220 DBG_FLT("binfmt_flat: unknown compression method?\n"); 221 goto out_free_buf; 222 } 223 /* Check gzip flags */ 224 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 225 (buf[3] & RESERVED)) { 226 DBG_FLT("binfmt_flat: unknown flags?\n"); 227 goto out_free_buf; 228 } 229 230 ret = 10; 231 if (buf[3] & EXTRA_FIELD) { 232 ret += 2 + buf[10] + (buf[11] << 8); 233 if (unlikely(LBUFSIZE == ret)) { 234 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 235 goto out_free_buf; 236 } 237 } 238 if (buf[3] & ORIG_NAME) { 239 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 240 ; 241 if (unlikely(LBUFSIZE == ret)) { 242 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 243 goto out_free_buf; 244 } 245 } 246 if (buf[3] & COMMENT) { 247 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 248 ; 249 if (unlikely(LBUFSIZE == ret)) { 250 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 251 goto out_free_buf; 252 } 253 } 254 255 strm.next_in += ret; 256 strm.avail_in -= ret; 257 258 strm.next_out = dst; 259 strm.avail_out = len; 260 strm.total_out = 0; 261 262 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 263 DBG_FLT("binfmt_flat: zlib init failed?\n"); 264 goto out_free_buf; 265 } 266 267 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 268 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 269 if (ret <= 0) 270 break; 271 if (ret >= (unsigned long) -4096) 272 break; 273 len -= ret; 274 275 strm.next_in = buf; 276 strm.avail_in = ret; 277 strm.total_in = 0; 278 } 279 280 if (ret < 0) { 281 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 282 ret, strm.msg); 283 goto out_zlib; 284 } 285 286 retval = 0; 287 out_zlib: 288 zlib_inflateEnd(&strm); 289 out_free_buf: 290 kfree(buf); 291 out_free: 292 kfree(strm.workspace); 293 out: 294 return retval; 295 } 296 297 #endif /* CONFIG_BINFMT_ZFLAT */ 298 299 /****************************************************************************/ 300 301 static unsigned long 302 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp) 303 { 304 unsigned long addr; 305 int id; 306 unsigned long start_brk; 307 unsigned long start_data; 308 unsigned long text_len; 309 unsigned long start_code; 310 311 #ifdef CONFIG_BINFMT_SHARED_FLAT 312 if (r == 0) 313 id = curid; /* Relocs of 0 are always self referring */ 314 else { 315 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 316 r &= 0x00ffffff; /* Trim ID off here */ 317 } 318 if (id >= MAX_SHARED_LIBS) { 319 printk("BINFMT_FLAT: reference 0x%x to shared library %d", 320 (unsigned) r, id); 321 goto failed; 322 } 323 if (curid != id) { 324 if (internalp) { 325 printk("BINFMT_FLAT: reloc address 0x%x not in same module " 326 "(%d != %d)", (unsigned) r, curid, id); 327 goto failed; 328 } else if ( ! p->lib_list[id].loaded && 329 load_flat_shared_library(id, p) > (unsigned long) -4096) { 330 printk("BINFMT_FLAT: failed to load library %d", id); 331 goto failed; 332 } 333 /* Check versioning information (i.e. time stamps) */ 334 if (p->lib_list[id].build_date && p->lib_list[curid].build_date && 335 p->lib_list[curid].build_date < p->lib_list[id].build_date) { 336 printk("BINFMT_FLAT: library %d is younger than %d", id, curid); 337 goto failed; 338 } 339 } 340 #else 341 id = 0; 342 #endif 343 344 start_brk = p->lib_list[id].start_brk; 345 start_data = p->lib_list[id].start_data; 346 start_code = p->lib_list[id].start_code; 347 text_len = p->lib_list[id].text_len; 348 349 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 350 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)", 351 (int) r,(int)(start_brk-start_code),(int)text_len); 352 goto failed; 353 } 354 355 if (r < text_len) /* In text segment */ 356 addr = r + start_code; 357 else /* In data segment */ 358 addr = r - text_len + start_data; 359 360 /* Range checked already above so doing the range tests is redundant...*/ 361 return(addr); 362 363 failed: 364 printk(", killing %s!\n", current->comm); 365 send_sig(SIGSEGV, current, 0); 366 367 return RELOC_FAILED; 368 } 369 370 /****************************************************************************/ 371 372 void old_reloc(unsigned long rl) 373 { 374 #ifdef DEBUG 375 char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 376 #endif 377 flat_v2_reloc_t r; 378 unsigned long *ptr; 379 380 r.value = rl; 381 #if defined(CONFIG_COLDFIRE) 382 ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset); 383 #else 384 ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset); 385 #endif 386 387 #ifdef DEBUG 388 printk("Relocation of variable at DATASEG+%x " 389 "(address %p, currently %x) into segment %s\n", 390 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]); 391 #endif 392 393 switch (r.reloc.type) { 394 case OLD_FLAT_RELOC_TYPE_TEXT: 395 *ptr += current->mm->start_code; 396 break; 397 case OLD_FLAT_RELOC_TYPE_DATA: 398 *ptr += current->mm->start_data; 399 break; 400 case OLD_FLAT_RELOC_TYPE_BSS: 401 *ptr += current->mm->end_data; 402 break; 403 default: 404 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type); 405 break; 406 } 407 408 #ifdef DEBUG 409 printk("Relocation became %x\n", (int)*ptr); 410 #endif 411 } 412 413 /****************************************************************************/ 414 415 static int load_flat_file(struct linux_binprm * bprm, 416 struct lib_info *libinfo, int id, unsigned long *extra_stack) 417 { 418 struct flat_hdr * hdr; 419 unsigned long textpos = 0, datapos = 0, result; 420 unsigned long realdatastart = 0; 421 unsigned long text_len, data_len, bss_len, stack_len, flags; 422 unsigned long len, reallen, memp = 0; 423 unsigned long extra, rlim; 424 unsigned long *reloc = 0, *rp; 425 struct inode *inode; 426 int i, rev, relocs = 0; 427 loff_t fpos; 428 unsigned long start_code, end_code; 429 int ret; 430 431 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 432 inode = bprm->file->f_path.dentry->d_inode; 433 434 text_len = ntohl(hdr->data_start); 435 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 436 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 437 stack_len = ntohl(hdr->stack_size); 438 if (extra_stack) { 439 stack_len += *extra_stack; 440 *extra_stack = stack_len; 441 } 442 relocs = ntohl(hdr->reloc_count); 443 flags = ntohl(hdr->flags); 444 rev = ntohl(hdr->rev); 445 446 if (strncmp(hdr->magic, "bFLT", 4)) { 447 /* 448 * because a lot of people do not manage to produce good 449 * flat binaries, we leave this printk to help them realise 450 * the problem. We only print the error if its not a script file 451 */ 452 if (strncmp(hdr->magic, "#!", 2)) 453 printk("BINFMT_FLAT: bad header magic\n"); 454 ret = -ENOEXEC; 455 goto err; 456 } 457 458 if (flags & FLAT_FLAG_KTRACE) 459 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 460 461 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 462 printk("BINFMT_FLAT: bad flat file version 0x%x (supported 0x%x and 0x%x)\n", rev, FLAT_VERSION, OLD_FLAT_VERSION); 463 ret = -ENOEXEC; 464 goto err; 465 } 466 467 /* Don't allow old format executables to use shared libraries */ 468 if (rev == OLD_FLAT_VERSION && id != 0) { 469 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n", 470 (int) FLAT_VERSION); 471 ret = -ENOEXEC; 472 goto err; 473 } 474 475 /* 476 * fix up the flags for the older format, there were all kinds 477 * of endian hacks, this only works for the simple cases 478 */ 479 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 480 flags = FLAT_FLAG_RAM; 481 482 #ifndef CONFIG_BINFMT_ZFLAT 483 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 484 printk("Support for ZFLAT executables is not enabled.\n"); 485 ret = -ENOEXEC; 486 goto err; 487 } 488 #endif 489 490 /* 491 * Check initial limits. This avoids letting people circumvent 492 * size limits imposed on them by creating programs with large 493 * arrays in the data or bss. 494 */ 495 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; 496 if (rlim >= RLIM_INFINITY) 497 rlim = ~0; 498 if (data_len + bss_len > rlim) { 499 ret = -ENOMEM; 500 goto err; 501 } 502 503 /* Flush all traces of the currently running executable */ 504 if (id == 0) { 505 result = flush_old_exec(bprm); 506 if (result) { 507 ret = result; 508 goto err; 509 } 510 511 /* OK, This is the point of no return */ 512 set_personality(PER_LINUX_32BIT); 513 } 514 515 /* 516 * calculate the extra space we need to map in 517 */ 518 extra = max(bss_len + stack_len, relocs * sizeof(unsigned long)); 519 520 /* 521 * there are a couple of cases here, the separate code/data 522 * case, and then the fully copied to RAM case which lumps 523 * it all together. 524 */ 525 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 526 /* 527 * this should give us a ROM ptr, but if it doesn't we don't 528 * really care 529 */ 530 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 531 532 down_write(¤t->mm->mmap_sem); 533 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0); 534 up_write(¤t->mm->mmap_sem); 535 if (!textpos || textpos >= (unsigned long) -4096) { 536 if (!textpos) 537 textpos = (unsigned long) -ENOMEM; 538 printk("Unable to mmap process text, errno %d\n", (int)-textpos); 539 ret = textpos; 540 goto err; 541 } 542 543 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 544 down_write(¤t->mm->mmap_sem); 545 realdatastart = do_mmap(0, 0, len, 546 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); 547 /* Remap to use all availabe slack region space */ 548 if (realdatastart && (realdatastart < (unsigned long)-4096)) { 549 reallen = ksize(realdatastart); 550 if (reallen > len) { 551 realdatastart = do_mremap(realdatastart, len, 552 reallen, MREMAP_FIXED, realdatastart); 553 } 554 } 555 up_write(¤t->mm->mmap_sem); 556 557 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) { 558 if (!realdatastart) 559 realdatastart = (unsigned long) -ENOMEM; 560 printk("Unable to allocate RAM for process data, errno %d\n", 561 (int)-datapos); 562 do_munmap(current->mm, textpos, text_len); 563 ret = realdatastart; 564 goto err; 565 } 566 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long); 567 568 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 569 (int)(data_len + bss_len + stack_len), (int)datapos); 570 571 fpos = ntohl(hdr->data_start); 572 #ifdef CONFIG_BINFMT_ZFLAT 573 if (flags & FLAT_FLAG_GZDATA) { 574 result = decompress_exec(bprm, fpos, (char *) datapos, 575 data_len + (relocs * sizeof(unsigned long)), 0); 576 } else 577 #endif 578 { 579 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 580 data_len + (relocs * sizeof(unsigned long)), &fpos); 581 } 582 if (result >= (unsigned long)-4096) { 583 printk("Unable to read data+bss, errno %d\n", (int)-result); 584 do_munmap(current->mm, textpos, text_len); 585 do_munmap(current->mm, realdatastart, data_len + extra); 586 ret = result; 587 goto err; 588 } 589 590 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len)); 591 memp = realdatastart; 592 593 } else { 594 595 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 596 down_write(¤t->mm->mmap_sem); 597 textpos = do_mmap(0, 0, len, 598 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); 599 /* Remap to use all availabe slack region space */ 600 if (textpos && (textpos < (unsigned long) -4096)) { 601 reallen = ksize(textpos); 602 if (reallen > len) { 603 textpos = do_mremap(textpos, len, reallen, 604 MREMAP_FIXED, textpos); 605 } 606 } 607 up_write(¤t->mm->mmap_sem); 608 609 if (!textpos || textpos >= (unsigned long) -4096) { 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 = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long); 620 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) + 621 MAX_SHARED_LIBS * sizeof(unsigned long)); 622 memp = textpos; 623 624 #ifdef CONFIG_BINFMT_ZFLAT 625 /* 626 * load it all in and treat it like a RAM load from now on 627 */ 628 if (flags & FLAT_FLAG_GZIP) { 629 result = decompress_exec(bprm, sizeof (struct flat_hdr), 630 (((char *) textpos) + sizeof (struct flat_hdr)), 631 (text_len + data_len + (relocs * sizeof(unsigned long)) 632 - sizeof (struct flat_hdr)), 633 0); 634 memmove((void *) datapos, (void *) realdatastart, 635 data_len + (relocs * sizeof(unsigned long))); 636 } else if (flags & FLAT_FLAG_GZDATA) { 637 fpos = 0; 638 result = bprm->file->f_op->read(bprm->file, 639 (char *) textpos, text_len, &fpos); 640 if (result < (unsigned long) -4096) 641 result = decompress_exec(bprm, text_len, (char *) datapos, 642 data_len + (relocs * sizeof(unsigned long)), 0); 643 } 644 else 645 #endif 646 { 647 fpos = 0; 648 result = bprm->file->f_op->read(bprm->file, 649 (char *) textpos, text_len, &fpos); 650 if (result < (unsigned long) -4096) { 651 fpos = ntohl(hdr->data_start); 652 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 653 data_len + (relocs * sizeof(unsigned long)), &fpos); 654 } 655 } 656 if (result >= (unsigned long)-4096) { 657 printk("Unable to read code+data+bss, errno %d\n",(int)-result); 658 do_munmap(current->mm, textpos, text_len + data_len + extra + 659 MAX_SHARED_LIBS * sizeof(unsigned long)); 660 ret = result; 661 goto err; 662 } 663 } 664 665 if (flags & FLAT_FLAG_KTRACE) 666 printk("Mapping is %x, Entry point is %x, data_start is %x\n", 667 (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start)); 668 669 /* The main program needs a little extra setup in the task structure */ 670 start_code = textpos + sizeof (struct flat_hdr); 671 end_code = textpos + text_len; 672 if (id == 0) { 673 current->mm->start_code = start_code; 674 current->mm->end_code = end_code; 675 current->mm->start_data = datapos; 676 current->mm->end_data = datapos + data_len; 677 /* 678 * set up the brk stuff, uses any slack left in data/bss/stack 679 * allocation. We put the brk after the bss (between the bss 680 * and stack) like other platforms. 681 */ 682 current->mm->start_brk = datapos + data_len + bss_len; 683 current->mm->brk = (current->mm->start_brk + 3) & ~3; 684 current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len; 685 } 686 687 if (flags & FLAT_FLAG_KTRACE) 688 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 689 id ? "Lib" : "Load", bprm->filename, 690 (int) start_code, (int) end_code, 691 (int) datapos, 692 (int) (datapos + data_len), 693 (int) (datapos + data_len), 694 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 695 696 text_len -= sizeof(struct flat_hdr); /* the real code len */ 697 698 /* Store the current module values into the global library structure */ 699 libinfo->lib_list[id].start_code = start_code; 700 libinfo->lib_list[id].start_data = datapos; 701 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len; 702 libinfo->lib_list[id].text_len = text_len; 703 libinfo->lib_list[id].loaded = 1; 704 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 705 libinfo->lib_list[id].build_date = ntohl(hdr->build_date); 706 707 /* 708 * We just load the allocations into some temporary memory to 709 * help simplify all this mumbo jumbo 710 * 711 * We've got two different sections of relocation entries. 712 * The first is the GOT which resides at the begining of the data segment 713 * and is terminated with a -1. This one can be relocated in place. 714 * The second is the extra relocation entries tacked after the image's 715 * data segment. These require a little more processing as the entry is 716 * really an offset into the image which contains an offset into the 717 * image. 718 */ 719 if (flags & FLAT_FLAG_GOTPIC) { 720 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) { 721 unsigned long addr; 722 if (*rp) { 723 addr = calc_reloc(*rp, libinfo, id, 0); 724 if (addr == RELOC_FAILED) { 725 ret = -ENOEXEC; 726 goto err; 727 } 728 *rp = addr; 729 } 730 } 731 } 732 733 /* 734 * Now run through the relocation entries. 735 * We've got to be careful here as C++ produces relocatable zero 736 * entries in the constructor and destructor tables which are then 737 * tested for being not zero (which will always occur unless we're 738 * based from address zero). This causes an endless loop as __start 739 * is at zero. The solution used is to not relocate zero addresses. 740 * This has the negative side effect of not allowing a global data 741 * reference to be statically initialised to _stext (I've moved 742 * __start to address 4 so that is okay). 743 */ 744 if (rev > OLD_FLAT_VERSION) { 745 for (i=0; i < relocs; i++) { 746 unsigned long addr, relval; 747 748 /* Get the address of the pointer to be 749 relocated (of course, the address has to be 750 relocated first). */ 751 relval = ntohl(reloc[i]); 752 addr = flat_get_relocate_addr(relval); 753 rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1); 754 if (rp == (unsigned long *)RELOC_FAILED) { 755 ret = -ENOEXEC; 756 goto err; 757 } 758 759 /* Get the pointer's value. */ 760 addr = flat_get_addr_from_rp(rp, relval, flags); 761 if (addr != 0) { 762 /* 763 * Do the relocation. PIC relocs in the data section are 764 * already in target order 765 */ 766 if ((flags & FLAT_FLAG_GOTPIC) == 0) 767 addr = ntohl(addr); 768 addr = calc_reloc(addr, libinfo, id, 0); 769 if (addr == RELOC_FAILED) { 770 ret = -ENOEXEC; 771 goto err; 772 } 773 774 /* Write back the relocated pointer. */ 775 flat_put_addr_at_rp(rp, addr, relval); 776 } 777 } 778 } else { 779 for (i=0; i < relocs; i++) 780 old_reloc(ntohl(reloc[i])); 781 } 782 783 flush_icache_range(start_code, end_code); 784 785 /* zero the BSS, BRK and stack areas */ 786 memset((void*)(datapos + data_len), 0, bss_len + 787 (memp + ksize((void *) memp) - stack_len - /* end brk */ 788 libinfo->lib_list[id].start_brk) + /* start brk */ 789 stack_len); 790 791 return 0; 792 err: 793 return ret; 794 } 795 796 797 /****************************************************************************/ 798 #ifdef CONFIG_BINFMT_SHARED_FLAT 799 800 /* 801 * Load a shared library into memory. The library gets its own data 802 * segment (including bss) but not argv/argc/environ. 803 */ 804 805 static int load_flat_shared_library(int id, struct lib_info *libs) 806 { 807 struct linux_binprm bprm; 808 int res; 809 char buf[16]; 810 811 /* Create the file name */ 812 sprintf(buf, "/lib/lib%d.so", id); 813 814 /* Open the file up */ 815 bprm.filename = buf; 816 bprm.file = open_exec(bprm.filename); 817 res = PTR_ERR(bprm.file); 818 if (IS_ERR(bprm.file)) 819 return res; 820 821 res = prepare_binprm(&bprm); 822 823 if (res <= (unsigned long)-4096) 824 res = load_flat_file(&bprm, libs, id, NULL); 825 if (bprm.file) { 826 allow_write_access(bprm.file); 827 fput(bprm.file); 828 bprm.file = NULL; 829 } 830 return(res); 831 } 832 833 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 834 /****************************************************************************/ 835 836 /* 837 * These are the functions used to load flat style executables and shared 838 * libraries. There is no binary dependent code anywhere else. 839 */ 840 841 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) 842 { 843 struct lib_info libinfo; 844 unsigned long p = bprm->p; 845 unsigned long stack_len; 846 unsigned long start_addr; 847 unsigned long *sp; 848 int res; 849 int i, j; 850 851 memset(&libinfo, 0, sizeof(libinfo)); 852 /* 853 * We have to add the size of our arguments to our stack size 854 * otherwise it's too easy for users to create stack overflows 855 * by passing in a huge argument list. And yes, we have to be 856 * pedantic and include space for the argv/envp array as it may have 857 * a lot of entries. 858 */ 859 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *)) 860 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */ 861 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ 862 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ 863 864 865 res = load_flat_file(bprm, &libinfo, 0, &stack_len); 866 if (res > (unsigned long)-4096) 867 return res; 868 869 /* Update data segment pointers for all libraries */ 870 for (i=0; i<MAX_SHARED_LIBS; i++) 871 if (libinfo.lib_list[i].loaded) 872 for (j=0; j<MAX_SHARED_LIBS; j++) 873 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] = 874 (libinfo.lib_list[j].loaded)? 875 libinfo.lib_list[j].start_data:UNLOADED_LIB; 876 877 compute_creds(bprm); 878 current->flags &= ~PF_FORKNOEXEC; 879 880 set_binfmt(&flat_format); 881 882 p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; 883 DBG_FLT("p=%x\n", (int)p); 884 885 /* copy the arg pages onto the stack, this could be more efficient :-) */ 886 for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--) 887 * (char *) --p = 888 ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE]; 889 890 sp = (unsigned long *) create_flat_tables(p, bprm); 891 892 /* Fake some return addresses to ensure the call chain will 893 * initialise library in order for us. We are required to call 894 * lib 1 first, then 2, ... and finally the main program (id 0). 895 */ 896 start_addr = libinfo.lib_list[0].entry; 897 898 #ifdef CONFIG_BINFMT_SHARED_FLAT 899 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 900 if (libinfo.lib_list[i].loaded) { 901 /* Push previos first to call address */ 902 --sp; put_user(start_addr, sp); 903 start_addr = libinfo.lib_list[i].entry; 904 } 905 } 906 #endif 907 908 /* Stash our initial stack pointer into the mm structure */ 909 current->mm->start_stack = (unsigned long )sp; 910 911 912 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n", 913 (int)regs, (int)start_addr, (int)current->mm->start_stack); 914 915 start_thread(regs, start_addr, current->mm->start_stack); 916 917 if (current->ptrace & PT_PTRACED) 918 send_sig(SIGTRAP, current, 0); 919 920 return 0; 921 } 922 923 /****************************************************************************/ 924 925 static int __init init_flat_binfmt(void) 926 { 927 return register_binfmt(&flat_format); 928 } 929 930 static void __exit exit_flat_binfmt(void) 931 { 932 unregister_binfmt(&flat_format); 933 } 934 935 /****************************************************************************/ 936 937 core_initcall(init_flat_binfmt); 938 module_exit(exit_flat_binfmt); 939 940 /****************************************************************************/ 941