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