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/config.h> 20 #include <linux/kernel.h> 21 #include <linux/sched.h> 22 #include <linux/mm.h> 23 #include <linux/mman.h> 24 #include <linux/a.out.h> 25 #include <linux/errno.h> 26 #include <linux/signal.h> 27 #include <linux/string.h> 28 #include <linux/fs.h> 29 #include <linux/file.h> 30 #include <linux/stat.h> 31 #include <linux/fcntl.h> 32 #include <linux/ptrace.h> 33 #include <linux/user.h> 34 #include <linux/slab.h> 35 #include <linux/binfmts.h> 36 #include <linux/personality.h> 37 #include <linux/init.h> 38 #include <linux/flat.h> 39 #include <linux/syscalls.h> 40 41 #include <asm/byteorder.h> 42 #include <asm/system.h> 43 #include <asm/uaccess.h> 44 #include <asm/unaligned.h> 45 #include <asm/cacheflush.h> 46 47 /****************************************************************************/ 48 49 #if 0 50 #define DEBUG 1 51 #endif 52 53 #ifdef DEBUG 54 #define DBG_FLT(a...) printk(a) 55 #else 56 #define DBG_FLT(a...) 57 #endif 58 59 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 60 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 61 62 struct lib_info { 63 struct { 64 unsigned long start_code; /* Start of text segment */ 65 unsigned long start_data; /* Start of data segment */ 66 unsigned long start_brk; /* End of data segment */ 67 unsigned long text_len; /* Length of text segment */ 68 unsigned long entry; /* Start address for this module */ 69 unsigned long build_date; /* When this one was compiled */ 70 short loaded; /* Has this library been loaded? */ 71 } lib_list[MAX_SHARED_LIBS]; 72 }; 73 74 #ifdef CONFIG_BINFMT_SHARED_FLAT 75 static int load_flat_shared_library(int id, struct lib_info *p); 76 #endif 77 78 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs); 79 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file); 80 81 static struct linux_binfmt flat_format = { 82 .module = THIS_MODULE, 83 .load_binary = load_flat_binary, 84 .core_dump = flat_core_dump, 85 .min_coredump = PAGE_SIZE 86 }; 87 88 /****************************************************************************/ 89 /* 90 * Routine writes a core dump image in the current directory. 91 * Currently only a stub-function. 92 */ 93 94 static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file) 95 { 96 printk("Process %s:%d received signr %d and should have core dumped\n", 97 current->comm, current->pid, (int) signr); 98 return(1); 99 } 100 101 /****************************************************************************/ 102 /* 103 * create_flat_tables() parses the env- and arg-strings in new user 104 * memory and creates the pointer tables from them, and puts their 105 * addresses on the "stack", returning the new stack pointer value. 106 */ 107 108 static unsigned long create_flat_tables( 109 unsigned long pp, 110 struct linux_binprm * bprm) 111 { 112 unsigned long *argv,*envp; 113 unsigned long * sp; 114 char * p = (char*)pp; 115 int argc = bprm->argc; 116 int envc = bprm->envc; 117 char dummy; 118 119 sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p); 120 121 sp -= envc+1; 122 envp = sp; 123 sp -= argc+1; 124 argv = sp; 125 126 flat_stack_align(sp); 127 if (flat_argvp_envp_on_stack()) { 128 --sp; put_user((unsigned long) envp, sp); 129 --sp; put_user((unsigned long) argv, sp); 130 } 131 132 put_user(argc,--sp); 133 current->mm->arg_start = (unsigned long) p; 134 while (argc-->0) { 135 put_user((unsigned long) p, argv++); 136 do { 137 get_user(dummy, p); p++; 138 } while (dummy); 139 } 140 put_user((unsigned long) NULL, argv); 141 current->mm->arg_end = current->mm->env_start = (unsigned long) p; 142 while (envc-->0) { 143 put_user((unsigned long)p, envp); envp++; 144 do { 145 get_user(dummy, p); p++; 146 } while (dummy); 147 } 148 put_user((unsigned long) NULL, envp); 149 current->mm->env_end = (unsigned long) p; 150 return (unsigned long)sp; 151 } 152 153 /****************************************************************************/ 154 155 #ifdef CONFIG_BINFMT_ZFLAT 156 157 #include <linux/zlib.h> 158 159 #define LBUFSIZE 4000 160 161 /* gzip flag byte */ 162 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 163 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 164 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 165 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 166 #define COMMENT 0x10 /* bit 4 set: file comment present */ 167 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 168 #define RESERVED 0xC0 /* bit 6,7: reserved */ 169 170 static int decompress_exec( 171 struct linux_binprm *bprm, 172 unsigned long offset, 173 char *dst, 174 long len, 175 int fd) 176 { 177 unsigned char *buf; 178 z_stream strm; 179 loff_t fpos; 180 int ret, retval; 181 182 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 183 184 memset(&strm, 0, sizeof(strm)); 185 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 186 if (strm.workspace == NULL) { 187 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 188 return -ENOMEM; 189 } 190 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 191 if (buf == NULL) { 192 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 193 retval = -ENOMEM; 194 goto out_free; 195 } 196 197 /* Read in first chunk of data and parse gzip header. */ 198 fpos = offset; 199 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 200 201 strm.next_in = buf; 202 strm.avail_in = ret; 203 strm.total_in = 0; 204 205 retval = -ENOEXEC; 206 207 /* Check minimum size -- gzip header */ 208 if (ret < 10) { 209 DBG_FLT("binfmt_flat: file too small?\n"); 210 goto out_free_buf; 211 } 212 213 /* Check gzip magic number */ 214 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 215 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 216 goto out_free_buf; 217 } 218 219 /* Check gzip method */ 220 if (buf[2] != 8) { 221 DBG_FLT("binfmt_flat: unknown compression method?\n"); 222 goto out_free_buf; 223 } 224 /* Check gzip flags */ 225 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 226 (buf[3] & RESERVED)) { 227 DBG_FLT("binfmt_flat: unknown flags?\n"); 228 goto out_free_buf; 229 } 230 231 ret = 10; 232 if (buf[3] & EXTRA_FIELD) { 233 ret += 2 + buf[10] + (buf[11] << 8); 234 if (unlikely(LBUFSIZE == ret)) { 235 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 236 goto out_free_buf; 237 } 238 } 239 if (buf[3] & ORIG_NAME) { 240 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 241 ; 242 if (unlikely(LBUFSIZE == ret)) { 243 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 244 goto out_free_buf; 245 } 246 } 247 if (buf[3] & COMMENT) { 248 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 249 ; 250 if (unlikely(LBUFSIZE == ret)) { 251 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 252 goto out_free_buf; 253 } 254 } 255 256 strm.next_in += ret; 257 strm.avail_in -= ret; 258 259 strm.next_out = dst; 260 strm.avail_out = len; 261 strm.total_out = 0; 262 263 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 264 DBG_FLT("binfmt_flat: zlib init failed?\n"); 265 goto out_free_buf; 266 } 267 268 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 269 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 270 if (ret <= 0) 271 break; 272 if (ret >= (unsigned long) -4096) 273 break; 274 len -= ret; 275 276 strm.next_in = buf; 277 strm.avail_in = ret; 278 strm.total_in = 0; 279 } 280 281 if (ret < 0) { 282 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 283 ret, strm.msg); 284 goto out_zlib; 285 } 286 287 retval = 0; 288 out_zlib: 289 zlib_inflateEnd(&strm); 290 out_free_buf: 291 kfree(buf); 292 out_free: 293 kfree(strm.workspace); 294 out: 295 return retval; 296 } 297 298 #endif /* CONFIG_BINFMT_ZFLAT */ 299 300 /****************************************************************************/ 301 302 static unsigned long 303 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp) 304 { 305 unsigned long addr; 306 int id; 307 unsigned long start_brk; 308 unsigned long start_data; 309 unsigned long text_len; 310 unsigned long start_code; 311 312 #ifdef CONFIG_BINFMT_SHARED_FLAT 313 if (r == 0) 314 id = curid; /* Relocs of 0 are always self referring */ 315 else { 316 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 317 r &= 0x00ffffff; /* Trim ID off here */ 318 } 319 if (id >= MAX_SHARED_LIBS) { 320 printk("BINFMT_FLAT: reference 0x%x to shared library %d", 321 (unsigned) r, id); 322 goto failed; 323 } 324 if (curid != id) { 325 if (internalp) { 326 printk("BINFMT_FLAT: reloc address 0x%x not in same module " 327 "(%d != %d)", (unsigned) r, curid, id); 328 goto failed; 329 } else if ( ! p->lib_list[id].loaded && 330 load_flat_shared_library(id, p) > (unsigned long) -4096) { 331 printk("BINFMT_FLAT: failed to load library %d", id); 332 goto failed; 333 } 334 /* Check versioning information (i.e. time stamps) */ 335 if (p->lib_list[id].build_date && p->lib_list[curid].build_date && 336 p->lib_list[curid].build_date < p->lib_list[id].build_date) { 337 printk("BINFMT_FLAT: library %d is younger than %d", id, curid); 338 goto failed; 339 } 340 } 341 #else 342 id = 0; 343 #endif 344 345 start_brk = p->lib_list[id].start_brk; 346 start_data = p->lib_list[id].start_data; 347 start_code = p->lib_list[id].start_code; 348 text_len = p->lib_list[id].text_len; 349 350 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 351 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)", 352 (int) r,(int)(start_brk-start_code),(int)text_len); 353 goto failed; 354 } 355 356 if (r < text_len) /* In text segment */ 357 addr = r + start_code; 358 else /* In data segment */ 359 addr = r - text_len + start_data; 360 361 /* Range checked already above so doing the range tests is redundant...*/ 362 return(addr); 363 364 failed: 365 printk(", killing %s!\n", current->comm); 366 send_sig(SIGSEGV, current, 0); 367 368 return RELOC_FAILED; 369 } 370 371 /****************************************************************************/ 372 373 void old_reloc(unsigned long rl) 374 { 375 #ifdef DEBUG 376 char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 377 #endif 378 flat_v2_reloc_t r; 379 unsigned long *ptr; 380 381 r.value = rl; 382 #if defined(CONFIG_COLDFIRE) 383 ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset); 384 #else 385 ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset); 386 #endif 387 388 #ifdef DEBUG 389 printk("Relocation of variable at DATASEG+%x " 390 "(address %p, currently %x) into segment %s\n", 391 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]); 392 #endif 393 394 switch (r.reloc.type) { 395 case OLD_FLAT_RELOC_TYPE_TEXT: 396 *ptr += current->mm->start_code; 397 break; 398 case OLD_FLAT_RELOC_TYPE_DATA: 399 *ptr += current->mm->start_data; 400 break; 401 case OLD_FLAT_RELOC_TYPE_BSS: 402 *ptr += current->mm->end_data; 403 break; 404 default: 405 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type); 406 break; 407 } 408 409 #ifdef DEBUG 410 printk("Relocation became %x\n", (int)*ptr); 411 #endif 412 } 413 414 /****************************************************************************/ 415 416 static int load_flat_file(struct linux_binprm * bprm, 417 struct lib_info *libinfo, int id, unsigned long *extra_stack) 418 { 419 struct flat_hdr * hdr; 420 unsigned long textpos = 0, datapos = 0, result; 421 unsigned long realdatastart = 0; 422 unsigned long text_len, data_len, bss_len, stack_len, flags; 423 unsigned long memp = 0; /* for finding the brk area */ 424 unsigned long extra, rlim; 425 unsigned long *reloc = 0, *rp; 426 struct inode *inode; 427 int i, rev, relocs = 0; 428 loff_t fpos; 429 unsigned long start_code, end_code; 430 int ret; 431 432 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 433 inode = bprm->file->f_dentry->d_inode; 434 435 text_len = ntohl(hdr->data_start); 436 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 437 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 438 stack_len = ntohl(hdr->stack_size); 439 if (extra_stack) { 440 stack_len += *extra_stack; 441 *extra_stack = stack_len; 442 } 443 relocs = ntohl(hdr->reloc_count); 444 flags = ntohl(hdr->flags); 445 rev = ntohl(hdr->rev); 446 447 if (strncmp(hdr->magic, "bFLT", 4)) { 448 /* 449 * because a lot of people do not manage to produce good 450 * flat binaries, we leave this printk to help them realise 451 * the problem. We only print the error if its not a script file 452 */ 453 if (strncmp(hdr->magic, "#!", 2)) 454 printk("BINFMT_FLAT: bad header magic\n"); 455 ret = -ENOEXEC; 456 goto err; 457 } 458 459 if (flags & FLAT_FLAG_KTRACE) 460 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 461 462 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 463 printk("BINFMT_FLAT: bad flat file version 0x%x (supported 0x%x and 0x%x)\n", rev, FLAT_VERSION, OLD_FLAT_VERSION); 464 ret = -ENOEXEC; 465 goto err; 466 } 467 468 /* Don't allow old format executables to use shared libraries */ 469 if (rev == OLD_FLAT_VERSION && id != 0) { 470 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n", 471 (int) FLAT_VERSION); 472 ret = -ENOEXEC; 473 goto err; 474 } 475 476 /* 477 * fix up the flags for the older format, there were all kinds 478 * of endian hacks, this only works for the simple cases 479 */ 480 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 481 flags = FLAT_FLAG_RAM; 482 483 #ifndef CONFIG_BINFMT_ZFLAT 484 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 485 printk("Support for ZFLAT executables is not enabled.\n"); 486 ret = -ENOEXEC; 487 goto err; 488 } 489 #endif 490 491 /* 492 * Check initial limits. This avoids letting people circumvent 493 * size limits imposed on them by creating programs with large 494 * arrays in the data or bss. 495 */ 496 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; 497 if (rlim >= RLIM_INFINITY) 498 rlim = ~0; 499 if (data_len + bss_len > rlim) { 500 ret = -ENOMEM; 501 goto err; 502 } 503 504 /* Flush all traces of the currently running executable */ 505 if (id == 0) { 506 result = flush_old_exec(bprm); 507 if (result) { 508 ret = result; 509 goto err; 510 } 511 512 /* OK, This is the point of no return */ 513 set_personality(PER_LINUX); 514 } 515 516 /* 517 * calculate the extra space we need to map in 518 */ 519 extra = max(bss_len + stack_len, relocs * sizeof(unsigned long)); 520 521 /* 522 * there are a couple of cases here, the separate code/data 523 * case, and then the fully copied to RAM case which lumps 524 * it all together. 525 */ 526 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 527 /* 528 * this should give us a ROM ptr, but if it doesn't we don't 529 * really care 530 */ 531 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 532 533 down_write(¤t->mm->mmap_sem); 534 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0); 535 up_write(¤t->mm->mmap_sem); 536 if (!textpos || textpos >= (unsigned long) -4096) { 537 if (!textpos) 538 textpos = (unsigned long) -ENOMEM; 539 printk("Unable to mmap process text, errno %d\n", (int)-textpos); 540 ret = textpos; 541 goto err; 542 } 543 544 down_write(¤t->mm->mmap_sem); 545 realdatastart = do_mmap(0, 0, data_len + extra + 546 MAX_SHARED_LIBS * sizeof(unsigned long), 547 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); 548 up_write(¤t->mm->mmap_sem); 549 550 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) { 551 if (!realdatastart) 552 realdatastart = (unsigned long) -ENOMEM; 553 printk("Unable to allocate RAM for process data, errno %d\n", 554 (int)-datapos); 555 do_munmap(current->mm, textpos, text_len); 556 ret = realdatastart; 557 goto err; 558 } 559 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long); 560 561 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 562 (int)(data_len + bss_len + stack_len), (int)datapos); 563 564 fpos = ntohl(hdr->data_start); 565 #ifdef CONFIG_BINFMT_ZFLAT 566 if (flags & FLAT_FLAG_GZDATA) { 567 result = decompress_exec(bprm, fpos, (char *) datapos, 568 data_len + (relocs * sizeof(unsigned long)), 0); 569 } else 570 #endif 571 { 572 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 573 data_len + (relocs * sizeof(unsigned long)), &fpos); 574 } 575 if (result >= (unsigned long)-4096) { 576 printk("Unable to read data+bss, errno %d\n", (int)-result); 577 do_munmap(current->mm, textpos, text_len); 578 do_munmap(current->mm, realdatastart, data_len + extra); 579 ret = result; 580 goto err; 581 } 582 583 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len)); 584 memp = realdatastart; 585 586 } else { 587 588 down_write(¤t->mm->mmap_sem); 589 textpos = do_mmap(0, 0, text_len + data_len + extra + 590 MAX_SHARED_LIBS * sizeof(unsigned long), 591 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); 592 up_write(¤t->mm->mmap_sem); 593 if (!textpos || textpos >= (unsigned long) -4096) { 594 if (!textpos) 595 textpos = (unsigned long) -ENOMEM; 596 printk("Unable to allocate RAM for process text/data, errno %d\n", 597 (int)-textpos); 598 ret = textpos; 599 goto err; 600 } 601 602 realdatastart = textpos + ntohl(hdr->data_start); 603 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long); 604 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) + 605 MAX_SHARED_LIBS * sizeof(unsigned long)); 606 memp = textpos; 607 608 #ifdef CONFIG_BINFMT_ZFLAT 609 /* 610 * load it all in and treat it like a RAM load from now on 611 */ 612 if (flags & FLAT_FLAG_GZIP) { 613 result = decompress_exec(bprm, sizeof (struct flat_hdr), 614 (((char *) textpos) + sizeof (struct flat_hdr)), 615 (text_len + data_len + (relocs * sizeof(unsigned long)) 616 - sizeof (struct flat_hdr)), 617 0); 618 memmove((void *) datapos, (void *) realdatastart, 619 data_len + (relocs * sizeof(unsigned long))); 620 } else if (flags & FLAT_FLAG_GZDATA) { 621 fpos = 0; 622 result = bprm->file->f_op->read(bprm->file, 623 (char *) textpos, text_len, &fpos); 624 if (result < (unsigned long) -4096) 625 result = decompress_exec(bprm, text_len, (char *) datapos, 626 data_len + (relocs * sizeof(unsigned long)), 0); 627 } 628 else 629 #endif 630 { 631 fpos = 0; 632 result = bprm->file->f_op->read(bprm->file, 633 (char *) textpos, text_len, &fpos); 634 if (result < (unsigned long) -4096) { 635 fpos = ntohl(hdr->data_start); 636 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 637 data_len + (relocs * sizeof(unsigned long)), &fpos); 638 } 639 } 640 if (result >= (unsigned long)-4096) { 641 printk("Unable to read code+data+bss, errno %d\n",(int)-result); 642 do_munmap(current->mm, textpos, text_len + data_len + extra + 643 MAX_SHARED_LIBS * sizeof(unsigned long)); 644 ret = result; 645 goto err; 646 } 647 } 648 649 if (flags & FLAT_FLAG_KTRACE) 650 printk("Mapping is %x, Entry point is %x, data_start is %x\n", 651 (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start)); 652 653 /* The main program needs a little extra setup in the task structure */ 654 start_code = textpos + sizeof (struct flat_hdr); 655 end_code = textpos + text_len; 656 if (id == 0) { 657 current->mm->start_code = start_code; 658 current->mm->end_code = end_code; 659 current->mm->start_data = datapos; 660 current->mm->end_data = datapos + data_len; 661 /* 662 * set up the brk stuff, uses any slack left in data/bss/stack 663 * allocation. We put the brk after the bss (between the bss 664 * and stack) like other platforms. 665 */ 666 current->mm->start_brk = datapos + data_len + bss_len; 667 current->mm->brk = (current->mm->start_brk + 3) & ~3; 668 current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len; 669 } 670 671 if (flags & FLAT_FLAG_KTRACE) 672 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 673 id ? "Lib" : "Load", bprm->filename, 674 (int) start_code, (int) end_code, 675 (int) datapos, 676 (int) (datapos + data_len), 677 (int) (datapos + data_len), 678 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 679 680 text_len -= sizeof(struct flat_hdr); /* the real code len */ 681 682 /* Store the current module values into the global library structure */ 683 libinfo->lib_list[id].start_code = start_code; 684 libinfo->lib_list[id].start_data = datapos; 685 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len; 686 libinfo->lib_list[id].text_len = text_len; 687 libinfo->lib_list[id].loaded = 1; 688 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 689 libinfo->lib_list[id].build_date = ntohl(hdr->build_date); 690 691 /* 692 * We just load the allocations into some temporary memory to 693 * help simplify all this mumbo jumbo 694 * 695 * We've got two different sections of relocation entries. 696 * The first is the GOT which resides at the begining of the data segment 697 * and is terminated with a -1. This one can be relocated in place. 698 * The second is the extra relocation entries tacked after the image's 699 * data segment. These require a little more processing as the entry is 700 * really an offset into the image which contains an offset into the 701 * image. 702 */ 703 if (flags & FLAT_FLAG_GOTPIC) { 704 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) { 705 unsigned long addr; 706 if (*rp) { 707 addr = calc_reloc(*rp, libinfo, id, 0); 708 if (addr == RELOC_FAILED) { 709 ret = -ENOEXEC; 710 goto err; 711 } 712 *rp = addr; 713 } 714 } 715 } 716 717 /* 718 * Now run through the relocation entries. 719 * We've got to be careful here as C++ produces relocatable zero 720 * entries in the constructor and destructor tables which are then 721 * tested for being not zero (which will always occur unless we're 722 * based from address zero). This causes an endless loop as __start 723 * is at zero. The solution used is to not relocate zero addresses. 724 * This has the negative side effect of not allowing a global data 725 * reference to be statically initialised to _stext (I've moved 726 * __start to address 4 so that is okay). 727 */ 728 if (rev > OLD_FLAT_VERSION) { 729 for (i=0; i < relocs; i++) { 730 unsigned long addr, relval; 731 732 /* Get the address of the pointer to be 733 relocated (of course, the address has to be 734 relocated first). */ 735 relval = ntohl(reloc[i]); 736 addr = flat_get_relocate_addr(relval); 737 rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1); 738 if (rp == (unsigned long *)RELOC_FAILED) { 739 ret = -ENOEXEC; 740 goto err; 741 } 742 743 /* Get the pointer's value. */ 744 addr = flat_get_addr_from_rp(rp, relval, flags); 745 if (addr != 0) { 746 /* 747 * Do the relocation. PIC relocs in the data section are 748 * already in target order 749 */ 750 if ((flags & FLAT_FLAG_GOTPIC) == 0) 751 addr = ntohl(addr); 752 addr = calc_reloc(addr, libinfo, id, 0); 753 if (addr == RELOC_FAILED) { 754 ret = -ENOEXEC; 755 goto err; 756 } 757 758 /* Write back the relocated pointer. */ 759 flat_put_addr_at_rp(rp, addr, relval); 760 } 761 } 762 } else { 763 for (i=0; i < relocs; i++) 764 old_reloc(ntohl(reloc[i])); 765 } 766 767 flush_icache_range(start_code, end_code); 768 769 /* zero the BSS, BRK and stack areas */ 770 memset((void*)(datapos + data_len), 0, bss_len + 771 (memp + ksize((void *) memp) - stack_len - /* end brk */ 772 libinfo->lib_list[id].start_brk) + /* start brk */ 773 stack_len); 774 775 return 0; 776 err: 777 return ret; 778 } 779 780 781 /****************************************************************************/ 782 #ifdef CONFIG_BINFMT_SHARED_FLAT 783 784 /* 785 * Load a shared library into memory. The library gets its own data 786 * segment (including bss) but not argv/argc/environ. 787 */ 788 789 static int load_flat_shared_library(int id, struct lib_info *libs) 790 { 791 struct linux_binprm bprm; 792 int res; 793 char buf[16]; 794 795 /* Create the file name */ 796 sprintf(buf, "/lib/lib%d.so", id); 797 798 /* Open the file up */ 799 bprm.filename = buf; 800 bprm.file = open_exec(bprm.filename); 801 res = PTR_ERR(bprm.file); 802 if (IS_ERR(bprm.file)) 803 return res; 804 805 res = prepare_binprm(&bprm); 806 807 if (res <= (unsigned long)-4096) 808 res = load_flat_file(&bprm, libs, id, NULL); 809 if (bprm.file) { 810 allow_write_access(bprm.file); 811 fput(bprm.file); 812 bprm.file = NULL; 813 } 814 return(res); 815 } 816 817 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 818 /****************************************************************************/ 819 820 /* 821 * These are the functions used to load flat style executables and shared 822 * libraries. There is no binary dependent code anywhere else. 823 */ 824 825 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) 826 { 827 struct lib_info libinfo; 828 unsigned long p = bprm->p; 829 unsigned long stack_len; 830 unsigned long start_addr; 831 unsigned long *sp; 832 int res; 833 int i, j; 834 835 memset(&libinfo, 0, sizeof(libinfo)); 836 /* 837 * We have to add the size of our arguments to our stack size 838 * otherwise it's too easy for users to create stack overflows 839 * by passing in a huge argument list. And yes, we have to be 840 * pedantic and include space for the argv/envp array as it may have 841 * a lot of entries. 842 */ 843 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *)) 844 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */ 845 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ 846 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ 847 848 849 res = load_flat_file(bprm, &libinfo, 0, &stack_len); 850 if (res > (unsigned long)-4096) 851 return res; 852 853 /* Update data segment pointers for all libraries */ 854 for (i=0; i<MAX_SHARED_LIBS; i++) 855 if (libinfo.lib_list[i].loaded) 856 for (j=0; j<MAX_SHARED_LIBS; j++) 857 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] = 858 (libinfo.lib_list[j].loaded)? 859 libinfo.lib_list[j].start_data:UNLOADED_LIB; 860 861 compute_creds(bprm); 862 current->flags &= ~PF_FORKNOEXEC; 863 864 set_binfmt(&flat_format); 865 866 p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; 867 DBG_FLT("p=%x\n", (int)p); 868 869 /* copy the arg pages onto the stack, this could be more efficient :-) */ 870 for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--) 871 * (char *) --p = 872 ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE]; 873 874 sp = (unsigned long *) create_flat_tables(p, bprm); 875 876 /* Fake some return addresses to ensure the call chain will 877 * initialise library in order for us. We are required to call 878 * lib 1 first, then 2, ... and finally the main program (id 0). 879 */ 880 start_addr = libinfo.lib_list[0].entry; 881 882 #ifdef CONFIG_BINFMT_SHARED_FLAT 883 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 884 if (libinfo.lib_list[i].loaded) { 885 /* Push previos first to call address */ 886 --sp; put_user(start_addr, sp); 887 start_addr = libinfo.lib_list[i].entry; 888 } 889 } 890 #endif 891 892 /* Stash our initial stack pointer into the mm structure */ 893 current->mm->start_stack = (unsigned long )sp; 894 895 896 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n", 897 (int)regs, (int)start_addr, (int)current->mm->start_stack); 898 899 start_thread(regs, start_addr, current->mm->start_stack); 900 901 if (current->ptrace & PT_PTRACED) 902 send_sig(SIGTRAP, current, 0); 903 904 return 0; 905 } 906 907 /****************************************************************************/ 908 909 static int __init init_flat_binfmt(void) 910 { 911 return register_binfmt(&flat_format); 912 } 913 914 static void __exit exit_flat_binfmt(void) 915 { 916 unregister_binfmt(&flat_format); 917 } 918 919 /****************************************************************************/ 920 921 core_initcall(init_flat_binfmt); 922 module_exit(exit_flat_binfmt); 923 924 /****************************************************************************/ 925