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