1 /****************************************************************************/ 2 /* 3 * linux/fs/binfmt_flat.c 4 * 5 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com> 6 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com> 7 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com> 8 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com> 9 * based heavily on: 10 * 11 * linux/fs/binfmt_aout.c: 12 * Copyright (C) 1991, 1992, 1996 Linus Torvalds 13 * linux/fs/binfmt_flat.c for 2.0 kernel 14 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com> 15 * JAN/99 -- coded full program relocation (gerg@snapgear.com) 16 */ 17 18 #include <linux/module.h> 19 #include <linux/kernel.h> 20 #include <linux/sched.h> 21 #include <linux/mm.h> 22 #include <linux/mman.h> 23 #include <linux/errno.h> 24 #include <linux/signal.h> 25 #include <linux/string.h> 26 #include <linux/fs.h> 27 #include <linux/file.h> 28 #include <linux/stat.h> 29 #include <linux/fcntl.h> 30 #include <linux/ptrace.h> 31 #include <linux/user.h> 32 #include <linux/slab.h> 33 #include <linux/binfmts.h> 34 #include <linux/personality.h> 35 #include <linux/init.h> 36 #include <linux/flat.h> 37 #include <linux/syscalls.h> 38 39 #include <asm/byteorder.h> 40 #include <asm/uaccess.h> 41 #include <asm/unaligned.h> 42 #include <asm/cacheflush.h> 43 #include <asm/page.h> 44 45 /****************************************************************************/ 46 47 #if 0 48 #define DEBUG 1 49 #endif 50 51 #ifdef DEBUG 52 #define DBG_FLT(a...) printk(a) 53 #else 54 #define DBG_FLT(a...) 55 #endif 56 57 /* 58 * User data (data section and bss) needs to be aligned. 59 * We pick 0x20 here because it is the max value elf2flt has always 60 * used in producing FLAT files, and because it seems to be large 61 * enough to make all the gcc alignment related tests happy. 62 */ 63 #define FLAT_DATA_ALIGN (0x20) 64 65 /* 66 * User data (stack) also needs to be aligned. 67 * Here we can be a bit looser than the data sections since this 68 * needs to only meet arch ABI requirements. 69 */ 70 #define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN) 71 72 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 73 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 74 75 struct lib_info { 76 struct { 77 unsigned long start_code; /* Start of text segment */ 78 unsigned long start_data; /* Start of data segment */ 79 unsigned long start_brk; /* End of data segment */ 80 unsigned long text_len; /* Length of text segment */ 81 unsigned long entry; /* Start address for this module */ 82 unsigned long build_date; /* When this one was compiled */ 83 short loaded; /* Has this library been loaded? */ 84 } lib_list[MAX_SHARED_LIBS]; 85 }; 86 87 #ifdef CONFIG_BINFMT_SHARED_FLAT 88 static int load_flat_shared_library(int id, struct lib_info *p); 89 #endif 90 91 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs); 92 static int flat_core_dump(struct coredump_params *cprm); 93 94 static struct linux_binfmt flat_format = { 95 .module = THIS_MODULE, 96 .load_binary = load_flat_binary, 97 .core_dump = flat_core_dump, 98 .min_coredump = PAGE_SIZE 99 }; 100 101 /****************************************************************************/ 102 /* 103 * Routine writes a core dump image in the current directory. 104 * Currently only a stub-function. 105 */ 106 107 static int flat_core_dump(struct coredump_params *cprm) 108 { 109 printk("Process %s:%d received signr %d and should have core dumped\n", 110 current->comm, current->pid, (int) cprm->signr); 111 return(1); 112 } 113 114 /****************************************************************************/ 115 /* 116 * create_flat_tables() parses the env- and arg-strings in new user 117 * memory and creates the pointer tables from them, and puts their 118 * addresses on the "stack", returning the new stack pointer value. 119 */ 120 121 static unsigned long create_flat_tables( 122 unsigned long pp, 123 struct linux_binprm * bprm) 124 { 125 unsigned long *argv,*envp; 126 unsigned long * sp; 127 char * p = (char*)pp; 128 int argc = bprm->argc; 129 int envc = bprm->envc; 130 char uninitialized_var(dummy); 131 132 sp = (unsigned long *)p; 133 sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0); 134 sp = (unsigned long *) ((unsigned long)sp & -FLAT_STACK_ALIGN); 135 argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0); 136 envp = argv + (argc + 1); 137 138 if (flat_argvp_envp_on_stack()) { 139 put_user((unsigned long) envp, sp + 2); 140 put_user((unsigned long) argv, sp + 1); 141 } 142 143 put_user(argc, sp); 144 current->mm->arg_start = (unsigned long) p; 145 while (argc-->0) { 146 put_user((unsigned long) p, argv++); 147 do { 148 get_user(dummy, p); p++; 149 } while (dummy); 150 } 151 put_user((unsigned long) NULL, argv); 152 current->mm->arg_end = current->mm->env_start = (unsigned long) p; 153 while (envc-->0) { 154 put_user((unsigned long)p, envp); envp++; 155 do { 156 get_user(dummy, p); p++; 157 } while (dummy); 158 } 159 put_user((unsigned long) NULL, envp); 160 current->mm->env_end = (unsigned long) p; 161 return (unsigned long)sp; 162 } 163 164 /****************************************************************************/ 165 166 #ifdef CONFIG_BINFMT_ZFLAT 167 168 #include <linux/zlib.h> 169 170 #define LBUFSIZE 4000 171 172 /* gzip flag byte */ 173 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 174 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 175 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 176 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 177 #define COMMENT 0x10 /* bit 4 set: file comment present */ 178 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 179 #define RESERVED 0xC0 /* bit 6,7: reserved */ 180 181 static int decompress_exec( 182 struct linux_binprm *bprm, 183 unsigned long offset, 184 char *dst, 185 long len, 186 int fd) 187 { 188 unsigned char *buf; 189 z_stream strm; 190 loff_t fpos; 191 int ret, retval; 192 193 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 194 195 memset(&strm, 0, sizeof(strm)); 196 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 197 if (strm.workspace == NULL) { 198 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 199 return -ENOMEM; 200 } 201 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 202 if (buf == NULL) { 203 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 204 retval = -ENOMEM; 205 goto out_free; 206 } 207 208 /* Read in first chunk of data and parse gzip header. */ 209 fpos = offset; 210 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 211 212 strm.next_in = buf; 213 strm.avail_in = ret; 214 strm.total_in = 0; 215 216 retval = -ENOEXEC; 217 218 /* Check minimum size -- gzip header */ 219 if (ret < 10) { 220 DBG_FLT("binfmt_flat: file too small?\n"); 221 goto out_free_buf; 222 } 223 224 /* Check gzip magic number */ 225 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 226 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 227 goto out_free_buf; 228 } 229 230 /* Check gzip method */ 231 if (buf[2] != 8) { 232 DBG_FLT("binfmt_flat: unknown compression method?\n"); 233 goto out_free_buf; 234 } 235 /* Check gzip flags */ 236 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 237 (buf[3] & RESERVED)) { 238 DBG_FLT("binfmt_flat: unknown flags?\n"); 239 goto out_free_buf; 240 } 241 242 ret = 10; 243 if (buf[3] & EXTRA_FIELD) { 244 ret += 2 + buf[10] + (buf[11] << 8); 245 if (unlikely(LBUFSIZE <= ret)) { 246 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 247 goto out_free_buf; 248 } 249 } 250 if (buf[3] & ORIG_NAME) { 251 while (ret < LBUFSIZE && buf[ret++] != 0) 252 ; 253 if (unlikely(LBUFSIZE == ret)) { 254 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 255 goto out_free_buf; 256 } 257 } 258 if (buf[3] & COMMENT) { 259 while (ret < LBUFSIZE && buf[ret++] != 0) 260 ; 261 if (unlikely(LBUFSIZE == ret)) { 262 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 263 goto out_free_buf; 264 } 265 } 266 267 strm.next_in += ret; 268 strm.avail_in -= ret; 269 270 strm.next_out = dst; 271 strm.avail_out = len; 272 strm.total_out = 0; 273 274 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 275 DBG_FLT("binfmt_flat: zlib init failed?\n"); 276 goto out_free_buf; 277 } 278 279 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 280 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 281 if (ret <= 0) 282 break; 283 len -= ret; 284 285 strm.next_in = buf; 286 strm.avail_in = ret; 287 strm.total_in = 0; 288 } 289 290 if (ret < 0) { 291 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 292 ret, strm.msg); 293 goto out_zlib; 294 } 295 296 retval = 0; 297 out_zlib: 298 zlib_inflateEnd(&strm); 299 out_free_buf: 300 kfree(buf); 301 out_free: 302 kfree(strm.workspace); 303 return retval; 304 } 305 306 #endif /* CONFIG_BINFMT_ZFLAT */ 307 308 /****************************************************************************/ 309 310 static unsigned long 311 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp) 312 { 313 unsigned long addr; 314 int id; 315 unsigned long start_brk; 316 unsigned long start_data; 317 unsigned long text_len; 318 unsigned long start_code; 319 320 #ifdef CONFIG_BINFMT_SHARED_FLAT 321 if (r == 0) 322 id = curid; /* Relocs of 0 are always self referring */ 323 else { 324 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 325 r &= 0x00ffffff; /* Trim ID off here */ 326 } 327 if (id >= MAX_SHARED_LIBS) { 328 printk("BINFMT_FLAT: reference 0x%x to shared library %d", 329 (unsigned) r, id); 330 goto failed; 331 } 332 if (curid != id) { 333 if (internalp) { 334 printk("BINFMT_FLAT: reloc address 0x%x not in same module " 335 "(%d != %d)", (unsigned) r, curid, id); 336 goto failed; 337 } else if ( ! p->lib_list[id].loaded && 338 IS_ERR_VALUE(load_flat_shared_library(id, p))) { 339 printk("BINFMT_FLAT: failed to load library %d", id); 340 goto failed; 341 } 342 /* Check versioning information (i.e. time stamps) */ 343 if (p->lib_list[id].build_date && p->lib_list[curid].build_date && 344 p->lib_list[curid].build_date < p->lib_list[id].build_date) { 345 printk("BINFMT_FLAT: library %d is younger than %d", id, curid); 346 goto failed; 347 } 348 } 349 #else 350 id = 0; 351 #endif 352 353 start_brk = p->lib_list[id].start_brk; 354 start_data = p->lib_list[id].start_data; 355 start_code = p->lib_list[id].start_code; 356 text_len = p->lib_list[id].text_len; 357 358 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 359 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)", 360 (int) r,(int)(start_brk-start_data+text_len),(int)text_len); 361 goto failed; 362 } 363 364 if (r < text_len) /* In text segment */ 365 addr = r + start_code; 366 else /* In data segment */ 367 addr = r - text_len + start_data; 368 369 /* Range checked already above so doing the range tests is redundant...*/ 370 return(addr); 371 372 failed: 373 printk(", killing %s!\n", current->comm); 374 send_sig(SIGSEGV, current, 0); 375 376 return RELOC_FAILED; 377 } 378 379 /****************************************************************************/ 380 381 void old_reloc(unsigned long rl) 382 { 383 #ifdef DEBUG 384 char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 385 #endif 386 flat_v2_reloc_t r; 387 unsigned long *ptr; 388 389 r.value = rl; 390 #if defined(CONFIG_COLDFIRE) 391 ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset); 392 #else 393 ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset); 394 #endif 395 396 #ifdef DEBUG 397 printk("Relocation of variable at DATASEG+%x " 398 "(address %p, currently %x) into segment %s\n", 399 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]); 400 #endif 401 402 switch (r.reloc.type) { 403 case OLD_FLAT_RELOC_TYPE_TEXT: 404 *ptr += current->mm->start_code; 405 break; 406 case OLD_FLAT_RELOC_TYPE_DATA: 407 *ptr += current->mm->start_data; 408 break; 409 case OLD_FLAT_RELOC_TYPE_BSS: 410 *ptr += current->mm->end_data; 411 break; 412 default: 413 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type); 414 break; 415 } 416 417 #ifdef DEBUG 418 printk("Relocation became %x\n", (int)*ptr); 419 #endif 420 } 421 422 /****************************************************************************/ 423 424 static int load_flat_file(struct linux_binprm * bprm, 425 struct lib_info *libinfo, int id, unsigned long *extra_stack) 426 { 427 struct flat_hdr * hdr; 428 unsigned long textpos = 0, datapos = 0, result; 429 unsigned long realdatastart = 0; 430 unsigned long text_len, data_len, bss_len, stack_len, flags; 431 unsigned long len, memp = 0; 432 unsigned long memp_size, extra, rlim; 433 unsigned long *reloc = 0, *rp; 434 struct inode *inode; 435 int i, rev, relocs = 0; 436 loff_t fpos; 437 unsigned long start_code, end_code; 438 int ret; 439 440 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 441 inode = bprm->file->f_path.dentry->d_inode; 442 443 text_len = ntohl(hdr->data_start); 444 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 445 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 446 stack_len = ntohl(hdr->stack_size); 447 if (extra_stack) { 448 stack_len += *extra_stack; 449 *extra_stack = stack_len; 450 } 451 relocs = ntohl(hdr->reloc_count); 452 flags = ntohl(hdr->flags); 453 rev = ntohl(hdr->rev); 454 455 if (strncmp(hdr->magic, "bFLT", 4)) { 456 /* 457 * Previously, here was a printk to tell people 458 * "BINFMT_FLAT: bad header magic". 459 * But for the kernel which also use ELF FD-PIC format, this 460 * error message is confusing. 461 * because a lot of people do not manage to produce good 462 */ 463 ret = -ENOEXEC; 464 goto err; 465 } 466 467 if (flags & FLAT_FLAG_KTRACE) 468 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 469 470 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 471 printk("BINFMT_FLAT: bad flat file version 0x%x (supported " 472 "0x%lx and 0x%lx)\n", 473 rev, FLAT_VERSION, OLD_FLAT_VERSION); 474 ret = -ENOEXEC; 475 goto err; 476 } 477 478 /* Don't allow old format executables to use shared libraries */ 479 if (rev == OLD_FLAT_VERSION && id != 0) { 480 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n", 481 (int) FLAT_VERSION); 482 ret = -ENOEXEC; 483 goto err; 484 } 485 486 /* 487 * fix up the flags for the older format, there were all kinds 488 * of endian hacks, this only works for the simple cases 489 */ 490 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 491 flags = FLAT_FLAG_RAM; 492 493 #ifndef CONFIG_BINFMT_ZFLAT 494 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 495 printk("Support for ZFLAT executables is not enabled.\n"); 496 ret = -ENOEXEC; 497 goto err; 498 } 499 #endif 500 501 /* 502 * Check initial limits. This avoids letting people circumvent 503 * size limits imposed on them by creating programs with large 504 * arrays in the data or bss. 505 */ 506 rlim = rlimit(RLIMIT_DATA); 507 if (rlim >= RLIM_INFINITY) 508 rlim = ~0; 509 if (data_len + bss_len > rlim) { 510 ret = -ENOMEM; 511 goto err; 512 } 513 514 /* Flush all traces of the currently running executable */ 515 if (id == 0) { 516 result = flush_old_exec(bprm); 517 if (result) { 518 ret = result; 519 goto err; 520 } 521 522 /* OK, This is the point of no return */ 523 set_personality(PER_LINUX_32BIT); 524 setup_new_exec(bprm); 525 } 526 527 /* 528 * calculate the extra space we need to map in 529 */ 530 extra = max_t(unsigned long, bss_len + stack_len, 531 relocs * sizeof(unsigned long)); 532 533 /* 534 * there are a couple of cases here, the separate code/data 535 * case, and then the fully copied to RAM case which lumps 536 * it all together. 537 */ 538 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 539 /* 540 * this should give us a ROM ptr, but if it doesn't we don't 541 * really care 542 */ 543 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 544 545 down_write(¤t->mm->mmap_sem); 546 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, 547 MAP_PRIVATE|MAP_EXECUTABLE, 0); 548 up_write(¤t->mm->mmap_sem); 549 if (!textpos || IS_ERR_VALUE(textpos)) { 550 if (!textpos) 551 textpos = (unsigned long) -ENOMEM; 552 printk("Unable to mmap process text, errno %d\n", (int)-textpos); 553 ret = textpos; 554 goto err; 555 } 556 557 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 558 len = PAGE_ALIGN(len); 559 down_write(¤t->mm->mmap_sem); 560 realdatastart = do_mmap(0, 0, len, 561 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); 562 up_write(¤t->mm->mmap_sem); 563 564 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) { 565 if (!realdatastart) 566 realdatastart = (unsigned long) -ENOMEM; 567 printk("Unable to allocate RAM for process data, errno %d\n", 568 (int)-realdatastart); 569 do_munmap(current->mm, textpos, text_len); 570 ret = realdatastart; 571 goto err; 572 } 573 datapos = ALIGN(realdatastart + 574 MAX_SHARED_LIBS * sizeof(unsigned long), 575 FLAT_DATA_ALIGN); 576 577 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 578 (int)(data_len + bss_len + stack_len), (int)datapos); 579 580 fpos = ntohl(hdr->data_start); 581 #ifdef CONFIG_BINFMT_ZFLAT 582 if (flags & FLAT_FLAG_GZDATA) { 583 result = decompress_exec(bprm, fpos, (char *) datapos, 584 data_len + (relocs * sizeof(unsigned long)), 0); 585 } else 586 #endif 587 { 588 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 589 data_len + (relocs * sizeof(unsigned long)), &fpos); 590 } 591 if (IS_ERR_VALUE(result)) { 592 printk("Unable to read data+bss, errno %d\n", (int)-result); 593 do_munmap(current->mm, textpos, text_len); 594 do_munmap(current->mm, realdatastart, len); 595 ret = result; 596 goto err; 597 } 598 599 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len)); 600 memp = realdatastart; 601 memp_size = len; 602 } else { 603 604 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 605 len = PAGE_ALIGN(len); 606 down_write(¤t->mm->mmap_sem); 607 textpos = do_mmap(0, 0, len, 608 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); 609 up_write(¤t->mm->mmap_sem); 610 611 if (!textpos || IS_ERR_VALUE(textpos)) { 612 if (!textpos) 613 textpos = (unsigned long) -ENOMEM; 614 printk("Unable to allocate RAM for process text/data, errno %d\n", 615 (int)-textpos); 616 ret = textpos; 617 goto err; 618 } 619 620 realdatastart = textpos + ntohl(hdr->data_start); 621 datapos = ALIGN(realdatastart + 622 MAX_SHARED_LIBS * sizeof(unsigned long), 623 FLAT_DATA_ALIGN); 624 625 reloc = (unsigned long *) 626 (datapos + (ntohl(hdr->reloc_start) - text_len)); 627 memp = textpos; 628 memp_size = len; 629 #ifdef CONFIG_BINFMT_ZFLAT 630 /* 631 * load it all in and treat it like a RAM load from now on 632 */ 633 if (flags & FLAT_FLAG_GZIP) { 634 result = decompress_exec(bprm, sizeof (struct flat_hdr), 635 (((char *) textpos) + sizeof (struct flat_hdr)), 636 (text_len + data_len + (relocs * sizeof(unsigned long)) 637 - sizeof (struct flat_hdr)), 638 0); 639 memmove((void *) datapos, (void *) realdatastart, 640 data_len + (relocs * sizeof(unsigned long))); 641 } else if (flags & FLAT_FLAG_GZDATA) { 642 fpos = 0; 643 result = bprm->file->f_op->read(bprm->file, 644 (char *) textpos, text_len, &fpos); 645 if (!IS_ERR_VALUE(result)) 646 result = decompress_exec(bprm, text_len, (char *) datapos, 647 data_len + (relocs * sizeof(unsigned long)), 0); 648 } 649 else 650 #endif 651 { 652 fpos = 0; 653 result = bprm->file->f_op->read(bprm->file, 654 (char *) textpos, text_len, &fpos); 655 if (!IS_ERR_VALUE(result)) { 656 fpos = ntohl(hdr->data_start); 657 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 658 data_len + (relocs * sizeof(unsigned long)), &fpos); 659 } 660 } 661 if (IS_ERR_VALUE(result)) { 662 printk("Unable to read code+data+bss, errno %d\n",(int)-result); 663 do_munmap(current->mm, textpos, text_len + data_len + extra + 664 MAX_SHARED_LIBS * sizeof(unsigned long)); 665 ret = result; 666 goto err; 667 } 668 } 669 670 if (flags & FLAT_FLAG_KTRACE) 671 printk("Mapping is %x, Entry point is %x, data_start is %x\n", 672 (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start)); 673 674 /* The main program needs a little extra setup in the task structure */ 675 start_code = textpos + sizeof (struct flat_hdr); 676 end_code = textpos + text_len; 677 if (id == 0) { 678 current->mm->start_code = start_code; 679 current->mm->end_code = end_code; 680 current->mm->start_data = datapos; 681 current->mm->end_data = datapos + data_len; 682 /* 683 * set up the brk stuff, uses any slack left in data/bss/stack 684 * allocation. We put the brk after the bss (between the bss 685 * and stack) like other platforms. 686 * Userspace code relies on the stack pointer starting out at 687 * an address right at the end of a page. 688 */ 689 current->mm->start_brk = datapos + data_len + bss_len; 690 current->mm->brk = (current->mm->start_brk + 3) & ~3; 691 current->mm->context.end_brk = memp + memp_size - stack_len; 692 } 693 694 if (flags & FLAT_FLAG_KTRACE) 695 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 696 id ? "Lib" : "Load", bprm->filename, 697 (int) start_code, (int) end_code, 698 (int) datapos, 699 (int) (datapos + data_len), 700 (int) (datapos + data_len), 701 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 702 703 text_len -= sizeof(struct flat_hdr); /* the real code len */ 704 705 /* Store the current module values into the global library structure */ 706 libinfo->lib_list[id].start_code = start_code; 707 libinfo->lib_list[id].start_data = datapos; 708 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len; 709 libinfo->lib_list[id].text_len = text_len; 710 libinfo->lib_list[id].loaded = 1; 711 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 712 libinfo->lib_list[id].build_date = ntohl(hdr->build_date); 713 714 /* 715 * We just load the allocations into some temporary memory to 716 * help simplify all this mumbo jumbo 717 * 718 * We've got two different sections of relocation entries. 719 * The first is the GOT which resides at the beginning of the data segment 720 * and is terminated with a -1. This one can be relocated in place. 721 * The second is the extra relocation entries tacked after the image's 722 * data segment. These require a little more processing as the entry is 723 * really an offset into the image which contains an offset into the 724 * image. 725 */ 726 if (flags & FLAT_FLAG_GOTPIC) { 727 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) { 728 unsigned long addr; 729 if (*rp) { 730 addr = calc_reloc(*rp, libinfo, id, 0); 731 if (addr == RELOC_FAILED) { 732 ret = -ENOEXEC; 733 goto err; 734 } 735 *rp = addr; 736 } 737 } 738 } 739 740 /* 741 * Now run through the relocation entries. 742 * We've got to be careful here as C++ produces relocatable zero 743 * entries in the constructor and destructor tables which are then 744 * tested for being not zero (which will always occur unless we're 745 * based from address zero). This causes an endless loop as __start 746 * is at zero. The solution used is to not relocate zero addresses. 747 * This has the negative side effect of not allowing a global data 748 * reference to be statically initialised to _stext (I've moved 749 * __start to address 4 so that is okay). 750 */ 751 if (rev > OLD_FLAT_VERSION) { 752 unsigned long persistent = 0; 753 for (i=0; i < relocs; i++) { 754 unsigned long addr, relval; 755 756 /* Get the address of the pointer to be 757 relocated (of course, the address has to be 758 relocated first). */ 759 relval = ntohl(reloc[i]); 760 if (flat_set_persistent (relval, &persistent)) 761 continue; 762 addr = flat_get_relocate_addr(relval); 763 rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1); 764 if (rp == (unsigned long *)RELOC_FAILED) { 765 ret = -ENOEXEC; 766 goto err; 767 } 768 769 /* Get the pointer's value. */ 770 addr = flat_get_addr_from_rp(rp, relval, flags, 771 &persistent); 772 if (addr != 0) { 773 /* 774 * Do the relocation. PIC relocs in the data section are 775 * already in target order 776 */ 777 if ((flags & FLAT_FLAG_GOTPIC) == 0) 778 addr = ntohl(addr); 779 addr = calc_reloc(addr, libinfo, id, 0); 780 if (addr == RELOC_FAILED) { 781 ret = -ENOEXEC; 782 goto err; 783 } 784 785 /* Write back the relocated pointer. */ 786 flat_put_addr_at_rp(rp, addr, relval); 787 } 788 } 789 } else { 790 for (i=0; i < relocs; i++) 791 old_reloc(ntohl(reloc[i])); 792 } 793 794 flush_icache_range(start_code, end_code); 795 796 /* zero the BSS, BRK and stack areas */ 797 memset((void*)(datapos + data_len), 0, bss_len + 798 (memp + memp_size - stack_len - /* end brk */ 799 libinfo->lib_list[id].start_brk) + /* start brk */ 800 stack_len); 801 802 return 0; 803 err: 804 return ret; 805 } 806 807 808 /****************************************************************************/ 809 #ifdef CONFIG_BINFMT_SHARED_FLAT 810 811 /* 812 * Load a shared library into memory. The library gets its own data 813 * segment (including bss) but not argv/argc/environ. 814 */ 815 816 static int load_flat_shared_library(int id, struct lib_info *libs) 817 { 818 struct linux_binprm bprm; 819 int res; 820 char buf[16]; 821 822 memset(&bprm, 0, sizeof(bprm)); 823 824 /* Create the file name */ 825 sprintf(buf, "/lib/lib%d.so", id); 826 827 /* Open the file up */ 828 bprm.filename = buf; 829 bprm.file = open_exec(bprm.filename); 830 res = PTR_ERR(bprm.file); 831 if (IS_ERR(bprm.file)) 832 return res; 833 834 bprm.cred = prepare_exec_creds(); 835 res = -ENOMEM; 836 if (!bprm.cred) 837 goto out; 838 839 /* We don't really care about recalculating credentials at this point 840 * as we're past the point of no return and are dealing with shared 841 * libraries. 842 */ 843 bprm.cred_prepared = 1; 844 845 res = prepare_binprm(&bprm); 846 847 if (!IS_ERR_VALUE(res)) 848 res = load_flat_file(&bprm, libs, id, NULL); 849 850 abort_creds(bprm.cred); 851 852 out: 853 allow_write_access(bprm.file); 854 fput(bprm.file); 855 856 return(res); 857 } 858 859 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 860 /****************************************************************************/ 861 862 /* 863 * These are the functions used to load flat style executables and shared 864 * libraries. There is no binary dependent code anywhere else. 865 */ 866 867 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) 868 { 869 struct lib_info libinfo; 870 unsigned long p = bprm->p; 871 unsigned long stack_len; 872 unsigned long start_addr; 873 unsigned long *sp; 874 int res; 875 int i, j; 876 877 memset(&libinfo, 0, sizeof(libinfo)); 878 /* 879 * We have to add the size of our arguments to our stack size 880 * otherwise it's too easy for users to create stack overflows 881 * by passing in a huge argument list. And yes, we have to be 882 * pedantic and include space for the argv/envp array as it may have 883 * a lot of entries. 884 */ 885 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *)) 886 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */ 887 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ 888 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ 889 stack_len += FLAT_STACK_ALIGN - 1; /* reserve for upcoming alignment */ 890 891 res = load_flat_file(bprm, &libinfo, 0, &stack_len); 892 if (IS_ERR_VALUE(res)) 893 return res; 894 895 /* Update data segment pointers for all libraries */ 896 for (i=0; i<MAX_SHARED_LIBS; i++) 897 if (libinfo.lib_list[i].loaded) 898 for (j=0; j<MAX_SHARED_LIBS; j++) 899 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] = 900 (libinfo.lib_list[j].loaded)? 901 libinfo.lib_list[j].start_data:UNLOADED_LIB; 902 903 install_exec_creds(bprm); 904 905 set_binfmt(&flat_format); 906 907 p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; 908 DBG_FLT("p=%x\n", (int)p); 909 910 /* copy the arg pages onto the stack, this could be more efficient :-) */ 911 for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--) 912 * (char *) --p = 913 ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE]; 914 915 sp = (unsigned long *) create_flat_tables(p, bprm); 916 917 /* Fake some return addresses to ensure the call chain will 918 * initialise library in order for us. We are required to call 919 * lib 1 first, then 2, ... and finally the main program (id 0). 920 */ 921 start_addr = libinfo.lib_list[0].entry; 922 923 #ifdef CONFIG_BINFMT_SHARED_FLAT 924 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 925 if (libinfo.lib_list[i].loaded) { 926 /* Push previos first to call address */ 927 --sp; put_user(start_addr, sp); 928 start_addr = libinfo.lib_list[i].entry; 929 } 930 } 931 #endif 932 933 /* Stash our initial stack pointer into the mm structure */ 934 current->mm->start_stack = (unsigned long )sp; 935 936 #ifdef FLAT_PLAT_INIT 937 FLAT_PLAT_INIT(regs); 938 #endif 939 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n", 940 (int)regs, (int)start_addr, (int)current->mm->start_stack); 941 942 start_thread(regs, start_addr, current->mm->start_stack); 943 944 return 0; 945 } 946 947 /****************************************************************************/ 948 949 static int __init init_flat_binfmt(void) 950 { 951 register_binfmt(&flat_format); 952 return 0; 953 } 954 955 /****************************************************************************/ 956 957 core_initcall(init_flat_binfmt); 958 959 /****************************************************************************/ 960