1/****************************************************************************/ 2/* 3 * linux/fs/binfmt_flat.c 4 * 5 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com> 6 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com> 7 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com> 8 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com> 9 * based heavily on: 10 * 11 * linux/fs/binfmt_aout.c: 12 * Copyright (C) 1991, 1992, 1996 Linus Torvalds 13 * linux/fs/binfmt_flat.c for 2.0 kernel 14 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com> 15 * JAN/99 -- coded full program relocation (gerg@snapgear.com) 16 */ 17 18#include <linux/module.h> 19#include <linux/kernel.h> 20#include <linux/sched.h> 21#include <linux/mm.h> 22#include <linux/mman.h> 23#include <linux/a.out.h> 24#include <linux/errno.h> 25#include <linux/signal.h> 26#include <linux/string.h> 27#include <linux/fs.h> 28#include <linux/file.h> 29#include <linux/stat.h> 30#include <linux/fcntl.h> 31#include <linux/ptrace.h> 32#include <linux/user.h> 33#include <linux/slab.h> 34#include <linux/binfmts.h> 35#include <linux/personality.h> 36#include <linux/init.h> 37#include <linux/flat.h> 38#include <linux/syscalls.h> 39 40#include <asm/byteorder.h> 41#include <asm/system.h> 42#include <asm/uaccess.h> 43#include <asm/unaligned.h> 44#include <asm/cacheflush.h> 45 46/****************************************************************************/ 47 48 49#ifdef DEBUG 50#define DBG_FLT(a...) printk(a) 51#else 52#define DBG_FLT(a...) 53#endif 54 55#define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 56#define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 57 58struct lib_info { 59 struct { 60 unsigned long start_code; /* Start of text segment */ 61 unsigned long start_data; /* Start of data segment */ 62 unsigned long start_brk; /* End of data segment */ 63 unsigned long text_len; /* Length of text segment */ 64 unsigned long entry; /* Start address for this module */ 65 unsigned long build_date; /* When this one was compiled */ 66 short loaded; /* Has this library been loaded? */ 67 } lib_list[MAX_SHARED_LIBS]; 68}; 69 70#ifdef CONFIG_BINFMT_SHARED_FLAT 71static int load_flat_shared_library(int id, struct lib_info *p); 72#endif 73 74static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs); 75static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file); 76 77static struct linux_binfmt flat_format = { 78 .module = THIS_MODULE, 79 .load_binary = load_flat_binary, 80 .core_dump = flat_core_dump, 81 .min_coredump = PAGE_SIZE 82}; 83 84/****************************************************************************/ 85/* 86 * Routine writes a core dump image in the current directory. 87 * Currently only a stub-function. 88 */ 89 90static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file) 91{ 92 printk("Process %s:%d received signr %d and should have core dumped\n", 93 current->comm, current->pid, (int) signr); 94 return(1); 95} 96 97/****************************************************************************/ 98/* 99 * create_flat_tables() parses the env- and arg-strings in new user 100 * memory and creates the pointer tables from them, and puts their 101 * addresses on the "stack", returning the new stack pointer value. 102 */ 103 104static unsigned long create_flat_tables( 105 unsigned long pp, 106 struct linux_binprm * bprm) 107{ 108 unsigned long *argv,*envp; 109 unsigned long * sp; 110 char * p = (char*)pp; 111 int argc = bprm->argc; 112 int envc = bprm->envc; 113 char dummy; 114 115 sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p); 116 117 sp -= envc+1; 118 envp = sp; 119 sp -= argc+1; 120 argv = sp; 121 122 flat_stack_align(sp); 123 if (flat_argvp_envp_on_stack()) { 124 --sp; put_user((unsigned long) envp, sp); 125 --sp; put_user((unsigned long) argv, sp); 126 } 127 128 put_user(argc,--sp); 129 current->mm->arg_start = (unsigned long) p; 130 while (argc-->0) { 131 put_user((unsigned long) p, argv++); 132 do { 133 get_user(dummy, p); p++; 134 } while (dummy); 135 } 136 put_user((unsigned long) NULL, argv); 137 current->mm->arg_end = current->mm->env_start = (unsigned long) p; 138 while (envc-->0) { 139 put_user((unsigned long)p, envp); envp++; 140 do { 141 get_user(dummy, p); p++; 142 } while (dummy); 143 } 144 put_user((unsigned long) NULL, envp); 145 current->mm->env_end = (unsigned long) p; 146 return (unsigned long)sp; 147} 148 149/****************************************************************************/ 150 151#ifdef CONFIG_BINFMT_ZFLAT 152 153#include <linux/zlib.h> 154 155#define LBUFSIZE 4000 156 157/* gzip flag byte */ 158#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 159#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 160#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 161#define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 162#define COMMENT 0x10 /* bit 4 set: file comment present */ 163#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 164#define RESERVED 0xC0 /* bit 6,7: reserved */ 165 166static int decompress_exec( 167 struct linux_binprm *bprm, 168 unsigned long offset, 169 char *dst, 170 long len, 171 int fd) 172{ 173 unsigned char *buf; 174 z_stream strm; 175 loff_t fpos; 176 int ret, retval; 177 178 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 179 180 memset(&strm, 0, sizeof(strm)); 181 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 182 if (strm.workspace == NULL) { 183 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 184 return -ENOMEM; 185 } 186 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 187 if (buf == NULL) { 188 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 189 retval = -ENOMEM; 190 goto out_free; 191 } 192 193 /* Read in first chunk of data and parse gzip header. */ 194 fpos = offset; 195 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 196 197 strm.next_in = buf; 198 strm.avail_in = ret; 199 strm.total_in = 0; 200 201 retval = -ENOEXEC; 202 203 /* Check minimum size -- gzip header */ 204 if (ret < 10) { 205 DBG_FLT("binfmt_flat: file too small?\n"); 206 goto out_free_buf; 207 } 208 209 /* Check gzip magic number */ 210 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 211 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 212 goto out_free_buf; 213 } 214 215 /* Check gzip method */ 216 if (buf[2] != 8) { 217 DBG_FLT("binfmt_flat: unknown compression method?\n"); 218 goto out_free_buf; 219 } 220 /* Check gzip flags */ 221 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 222 (buf[3] & RESERVED)) { 223 DBG_FLT("binfmt_flat: unknown flags?\n"); 224 goto out_free_buf; 225 } 226 227 ret = 10; 228 if (buf[3] & EXTRA_FIELD) { 229 ret += 2 + buf[10] + (buf[11] << 8); 230 if (unlikely(LBUFSIZE == ret)) { 231 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 232 goto out_free_buf; 233 } 234 } 235 if (buf[3] & ORIG_NAME) { 236 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 237 ; 238 if (unlikely(LBUFSIZE == ret)) { 239 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 240 goto out_free_buf; 241 } 242 } 243 if (buf[3] & COMMENT) { 244 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++) 245 ; 246 if (unlikely(LBUFSIZE == ret)) { 247 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 248 goto out_free_buf; 249 } 250 } 251 252 strm.next_in += ret; 253 strm.avail_in -= ret; 254 255 strm.next_out = dst; 256 strm.avail_out = len; 257 strm.total_out = 0; 258 259 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 260 DBG_FLT("binfmt_flat: zlib init failed?\n"); 261 goto out_free_buf; 262 } 263 264 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 265 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 266 if (ret <= 0) 267 break; 268 if (ret >= (unsigned long) -4096) 269 break; 270 len -= ret; 271 272 strm.next_in = buf; 273 strm.avail_in = ret; 274 strm.total_in = 0; 275 } 276 277 if (ret < 0) { 278 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 279 ret, strm.msg); 280 goto out_zlib; 281 } 282 283 retval = 0; 284out_zlib: 285 zlib_inflateEnd(&strm); 286out_free_buf: 287 kfree(buf); 288out_free: 289 kfree(strm.workspace); 290out: 291 return retval; 292} 293 294#endif /* CONFIG_BINFMT_ZFLAT */ 295 296/****************************************************************************/ 297 298static unsigned long 299calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp) 300{ 301 unsigned long addr; 302 int id; 303 unsigned long start_brk; 304 unsigned long start_data; 305 unsigned long text_len; 306 unsigned long start_code; 307 308#ifdef CONFIG_BINFMT_SHARED_FLAT 309 if (r == 0) 310 id = curid; /* Relocs of 0 are always self referring */ 311 else { 312 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 313 r &= 0x00ffffff; /* Trim ID off here */ 314 } 315 if (id >= MAX_SHARED_LIBS) { 316 printk("BINFMT_FLAT: reference 0x%x to shared library %d", 317 (unsigned) r, id); 318 goto failed; 319 } 320 if (curid != id) { 321 if (internalp) { 322 printk("BINFMT_FLAT: reloc address 0x%x not in same module " 323 "(%d != %d)", (unsigned) r, curid, id); 324 goto failed; 325 } else if ( ! p->lib_list[id].loaded && 326 load_flat_shared_library(id, p) > (unsigned long) -4096) { 327 printk("BINFMT_FLAT: failed to load library %d", id); 328 goto failed; 329 } 330 /* Check versioning information (i.e. time stamps) */ 331 if (p->lib_list[id].build_date && p->lib_list[curid].build_date && 332 p->lib_list[curid].build_date < p->lib_list[id].build_date) { 333 printk("BINFMT_FLAT: library %d is younger than %d", id, curid); 334 goto failed; 335 } 336 } 337#else 338 id = 0; 339#endif 340 341 start_brk = p->lib_list[id].start_brk; 342 start_data = p->lib_list[id].start_data; 343 start_code = p->lib_list[id].start_code; 344 text_len = p->lib_list[id].text_len; 345 346 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 347 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)", 348 (int) r,(int)(start_brk-start_code),(int)text_len); 349 goto failed; 350 } 351 352 if (r < text_len) /* In text segment */ 353 addr = r + start_code; 354 else /* In data segment */ 355 addr = r - text_len + start_data; 356 357 /* Range checked already above so doing the range tests is redundant...*/ 358 return(addr); 359 360failed: 361 printk(", killing %s!\n", current->comm); 362 send_sig(SIGSEGV, current, 0); 363 364 return RELOC_FAILED; 365} 366 367/****************************************************************************/ 368 369void old_reloc(unsigned long rl) 370{ 371#ifdef DEBUG 372 char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 373#endif 374 flat_v2_reloc_t r; 375 unsigned long *ptr; 376 377 r.value = rl; 378#if defined(CONFIG_COLDFIRE) 379 ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset); 380#else 381 ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset); 382#endif 383 384#ifdef DEBUG 385 printk("Relocation of variable at DATASEG+%x " 386 "(address %p, currently %x) into segment %s\n", 387 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]); 388#endif 389 390 switch (r.reloc.type) { 391 case OLD_FLAT_RELOC_TYPE_TEXT: 392 *ptr += current->mm->start_code; 393 break; 394 case OLD_FLAT_RELOC_TYPE_DATA: 395 *ptr += current->mm->start_data; 396 break; 397 case OLD_FLAT_RELOC_TYPE_BSS: 398 *ptr += current->mm->end_data; 399 break; 400 default: 401 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type); 402 break; 403 } 404 405#ifdef DEBUG 406 printk("Relocation became %x\n", (int)*ptr); 407#endif 408} 409 410/****************************************************************************/ 411 412static int load_flat_file(struct linux_binprm * bprm, 413 struct lib_info *libinfo, int id, unsigned long *extra_stack) 414{ 415 struct flat_hdr * hdr; 416 unsigned long textpos = 0, datapos = 0, result; 417 unsigned long realdatastart = 0; 418 unsigned long text_len, data_len, bss_len, stack_len, flags; 419 unsigned long len, reallen, memp = 0; 420 unsigned long extra, rlim; 421 unsigned long *reloc = 0, *rp; 422 struct inode *inode; 423 int i, rev, relocs = 0; 424 loff_t fpos; 425 unsigned long start_code, end_code; 426 int ret; 427 428 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 429 inode = bprm->file->f_path.dentry->d_inode; 430 431 text_len = ntohl(hdr->data_start); 432 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 433 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 434 stack_len = ntohl(hdr->stack_size); 435 if (extra_stack) { 436 stack_len += *extra_stack; 437 *extra_stack = stack_len; 438 } 439 relocs = ntohl(hdr->reloc_count); 440 flags = ntohl(hdr->flags); 441 rev = ntohl(hdr->rev); 442 443 if (strncmp(hdr->magic, "bFLT", 4)) { 444 /* 445 * because a lot of people do not manage to produce good 446 * flat binaries, we leave this printk to help them realise 447 * the problem. We only print the error if its not a script file 448 */ 449 if (strncmp(hdr->magic, "#!", 2)) 450 printk("BINFMT_FLAT: bad header magic\n"); 451 ret = -ENOEXEC; 452 goto err; 453 } 454 455 if (flags & FLAT_FLAG_KTRACE) 456 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 457 458 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 459 printk("BINFMT_FLAT: bad flat file version 0x%x (supported 0x%x and 0x%x)\n", rev, FLAT_VERSION, OLD_FLAT_VERSION); 460 ret = -ENOEXEC; 461 goto err; 462 } 463 464 /* Don't allow old format executables to use shared libraries */ 465 if (rev == OLD_FLAT_VERSION && id != 0) { 466 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n", 467 (int) FLAT_VERSION); 468 ret = -ENOEXEC; 469 goto err; 470 } 471 472 /* 473 * fix up the flags for the older format, there were all kinds 474 * of endian hacks, this only works for the simple cases 475 */ 476 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 477 flags = FLAT_FLAG_RAM; 478 479#ifndef CONFIG_BINFMT_ZFLAT 480 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 481 printk("Support for ZFLAT executables is not enabled.\n"); 482 ret = -ENOEXEC; 483 goto err; 484 } 485#endif 486 487 /* 488 * Check initial limits. This avoids letting people circumvent 489 * size limits imposed on them by creating programs with large 490 * arrays in the data or bss. 491 */ 492 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; 493 if (rlim >= RLIM_INFINITY) 494 rlim = ~0; 495 if (data_len + bss_len > rlim) { 496 ret = -ENOMEM; 497 goto err; 498 } 499 500 /* Flush all traces of the currently running executable */ 501 if (id == 0) { 502 result = flush_old_exec(bprm); 503 if (result) { 504 ret = result; 505 goto err; 506 } 507 508 /* OK, This is the point of no return */ 509 set_personality(PER_LINUX_32BIT); 510 } 511 512 /* 513 * calculate the extra space we need to map in 514 */ 515 extra = max(bss_len + stack_len, relocs * sizeof(unsigned long)); 516 517 /* 518 * there are a couple of cases here, the separate code/data 519 * case, and then the fully copied to RAM case which lumps 520 * it all together. 521 */ 522 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 523 /* 524 * this should give us a ROM ptr, but if it doesn't we don't 525 * really care 526 */ 527 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 528 529 down_write(¤t->mm->mmap_sem); 530 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0); 531 up_write(¤t->mm->mmap_sem); 532 if (!textpos || textpos >= (unsigned long) -4096) { 533 if (!textpos) 534 textpos = (unsigned long) -ENOMEM; 535 printk("Unable to mmap process text, errno %d\n", (int)-textpos); 536 ret = textpos; 537 goto err; 538 } 539 540 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 541 down_write(¤t->mm->mmap_sem); 542 realdatastart = do_mmap(0, 0, len, 543 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); 544 /* Remap to use all availabe slack region space */ 545 if (realdatastart && (realdatastart < (unsigned long)-4096)) { 546 reallen = ksize(realdatastart); 547 if (reallen > len) { 548 realdatastart = do_mremap(realdatastart, len, 549 reallen, MREMAP_FIXED, realdatastart); 550 } 551 } 552 up_write(¤t->mm->mmap_sem); 553 554 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) { 555 if (!realdatastart) 556 realdatastart = (unsigned long) -ENOMEM; 557 printk("Unable to allocate RAM for process data, errno %d\n", 558 (int)-realdatastart); 559 do_munmap(current->mm, textpos, text_len); 560 ret = realdatastart; 561 goto err; 562 } 563 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long); 564 565 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 566 (int)(data_len + bss_len + stack_len), (int)datapos); 567 568 fpos = ntohl(hdr->data_start); 569#ifdef CONFIG_BINFMT_ZFLAT 570 if (flags & FLAT_FLAG_GZDATA) { 571 result = decompress_exec(bprm, fpos, (char *) datapos, 572 data_len + (relocs * sizeof(unsigned long)), 0); 573 } else 574#endif 575 { 576 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 577 data_len + (relocs * sizeof(unsigned long)), &fpos); 578 } 579 if (result >= (unsigned long)-4096) { 580 printk("Unable to read data+bss, errno %d\n", (int)-result); 581 do_munmap(current->mm, textpos, text_len); 582 do_munmap(current->mm, realdatastart, data_len + extra); 583 ret = result; 584 goto err; 585 } 586 587 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len)); 588 memp = realdatastart; 589 590 } else { 591 592 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 593 down_write(¤t->mm->mmap_sem); 594 textpos = do_mmap(0, 0, len, 595 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); 596 /* Remap to use all availabe slack region space */ 597 if (textpos && (textpos < (unsigned long) -4096)) { 598 reallen = ksize(textpos); 599 if (reallen > len) { 600 textpos = do_mremap(textpos, len, reallen, 601 MREMAP_FIXED, textpos); 602 } 603 } 604 up_write(¤t->mm->mmap_sem); 605 606 if (!textpos || textpos >= (unsigned long) -4096) { 607 if (!textpos) 608 textpos = (unsigned long) -ENOMEM; 609 printk("Unable to allocate RAM for process text/data, errno %d\n", 610 (int)-textpos); 611 ret = textpos; 612 goto err; 613 } 614 615 realdatastart = textpos + ntohl(hdr->data_start); 616 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long); 617 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) + 618 MAX_SHARED_LIBS * sizeof(unsigned long)); 619 memp = textpos; 620 621#ifdef CONFIG_BINFMT_ZFLAT 622 /* 623 * load it all in and treat it like a RAM load from now on 624 */ 625 if (flags & FLAT_FLAG_GZIP) { 626 result = decompress_exec(bprm, sizeof (struct flat_hdr), 627 (((char *) textpos) + sizeof (struct flat_hdr)), 628 (text_len + data_len + (relocs * sizeof(unsigned long)) 629 - sizeof (struct flat_hdr)), 630 0); 631 memmove((void *) datapos, (void *) realdatastart, 632 data_len + (relocs * sizeof(unsigned long))); 633 } else if (flags & FLAT_FLAG_GZDATA) { 634 fpos = 0; 635 result = bprm->file->f_op->read(bprm->file, 636 (char *) textpos, text_len, &fpos); 637 if (result < (unsigned long) -4096) 638 result = decompress_exec(bprm, text_len, (char *) datapos, 639 data_len + (relocs * sizeof(unsigned long)), 0); 640 } 641 else 642#endif 643 { 644 fpos = 0; 645 result = bprm->file->f_op->read(bprm->file, 646 (char *) textpos, text_len, &fpos); 647 if (result < (unsigned long) -4096) { 648 fpos = ntohl(hdr->data_start); 649 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 650 data_len + (relocs * sizeof(unsigned long)), &fpos); 651 } 652 } 653 if (result >= (unsigned long)-4096) { 654 printk("Unable to read code+data+bss, errno %d\n",(int)-result); 655 do_munmap(current->mm, textpos, text_len + data_len + extra + 656 MAX_SHARED_LIBS * sizeof(unsigned long)); 657 ret = result; 658 goto err; 659 } 660 } 661 662 if (flags & FLAT_FLAG_KTRACE) 663 printk("Mapping is %x, Entry point is %x, data_start is %x\n", 664 (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start)); 665 666 /* The main program needs a little extra setup in the task structure */ 667 start_code = textpos + sizeof (struct flat_hdr); 668 end_code = textpos + text_len; 669 if (id == 0) { 670 current->mm->start_code = start_code; 671 current->mm->end_code = end_code; 672 current->mm->start_data = datapos; 673 current->mm->end_data = datapos + data_len; 674 /* 675 * set up the brk stuff, uses any slack left in data/bss/stack 676 * allocation. We put the brk after the bss (between the bss 677 * and stack) like other platforms. 678 */ 679 current->mm->start_brk = datapos + data_len + bss_len; 680 current->mm->brk = (current->mm->start_brk + 3) & ~3; 681 current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len; 682 } 683 684 if (flags & FLAT_FLAG_KTRACE) 685 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 686 id ? "Lib" : "Load", bprm->filename, 687 (int) start_code, (int) end_code, 688 (int) datapos, 689 (int) (datapos + data_len), 690 (int) (datapos + data_len), 691 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 692 693 text_len -= sizeof(struct flat_hdr); /* the real code len */ 694 695 /* Store the current module values into the global library structure */ 696 libinfo->lib_list[id].start_code = start_code; 697 libinfo->lib_list[id].start_data = datapos; 698 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len; 699 libinfo->lib_list[id].text_len = text_len; 700 libinfo->lib_list[id].loaded = 1; 701 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 702 libinfo->lib_list[id].build_date = ntohl(hdr->build_date); 703 704 /* 705 * We just load the allocations into some temporary memory to 706 * help simplify all this mumbo jumbo 707 * 708 * We've got two different sections of relocation entries. 709 * The first is the GOT which resides at the begining of the data segment 710 * and is terminated with a -1. This one can be relocated in place. 711 * The second is the extra relocation entries tacked after the image's 712 * data segment. These require a little more processing as the entry is 713 * really an offset into the image which contains an offset into the 714 * image. 715 */ 716 if (flags & FLAT_FLAG_GOTPIC) { 717 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) { 718 unsigned long addr; 719 if (*rp) { 720 addr = calc_reloc(*rp, libinfo, id, 0); 721 if (addr == RELOC_FAILED) { 722 ret = -ENOEXEC; 723 goto err; 724 } 725 *rp = addr; 726 } 727 } 728 } 729 730 /* 731 * Now run through the relocation entries. 732 * We've got to be careful here as C++ produces relocatable zero 733 * entries in the constructor and destructor tables which are then 734 * tested for being not zero (which will always occur unless we're 735 * based from address zero). This causes an endless loop as __start 736 * is at zero. The solution used is to not relocate zero addresses. 737 * This has the negative side effect of not allowing a global data 738 * reference to be statically initialised to _stext (I've moved 739 * __start to address 4 so that is okay). 740 */ 741 if (rev > OLD_FLAT_VERSION) { 742 for (i=0; i < relocs; i++) { 743 unsigned long addr, relval; 744 745 /* Get the address of the pointer to be 746 relocated (of course, the address has to be 747 relocated first). */ 748 relval = ntohl(reloc[i]); 749 addr = flat_get_relocate_addr(relval); 750 rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1); 751 if (rp == (unsigned long *)RELOC_FAILED) { 752 ret = -ENOEXEC; 753 goto err; 754 } 755 756 /* Get the pointer's value. */ 757 addr = flat_get_addr_from_rp(rp, relval, flags); 758 if (addr != 0) { 759 /* 760 * Do the relocation. PIC relocs in the data section are 761 * already in target order 762 */ 763 if ((flags & FLAT_FLAG_GOTPIC) == 0) 764 addr = ntohl(addr); 765 addr = calc_reloc(addr, libinfo, id, 0); 766 if (addr == RELOC_FAILED) { 767 ret = -ENOEXEC; 768 goto err; 769 } 770 771 /* Write back the relocated pointer. */ 772 flat_put_addr_at_rp(rp, addr, relval); 773 } 774 } 775 } else { 776 for (i=0; i < relocs; i++) 777 old_reloc(ntohl(reloc[i])); 778 } 779 780 flush_icache_range(start_code, end_code); 781 782 /* zero the BSS, BRK and stack areas */ 783 memset((void*)(datapos + data_len), 0, bss_len + 784 (memp + ksize((void *) memp) - stack_len - /* end brk */ 785 libinfo->lib_list[id].start_brk) + /* start brk */ 786 stack_len); 787 788 return 0; 789err: 790 return ret; 791} 792 793 794/****************************************************************************/ 795#ifdef CONFIG_BINFMT_SHARED_FLAT 796 797/* 798 * Load a shared library into memory. The library gets its own data 799 * segment (including bss) but not argv/argc/environ. 800 */ 801 802static int load_flat_shared_library(int id, struct lib_info *libs) 803{ 804 struct linux_binprm bprm; 805 int res; 806 char buf[16]; 807 808 /* Create the file name */ 809 sprintf(buf, "/lib/lib%d.so", id); 810 811 /* Open the file up */ 812 bprm.filename = buf; 813 bprm.file = open_exec(bprm.filename); 814 res = PTR_ERR(bprm.file); 815 if (IS_ERR(bprm.file)) 816 return res; 817 818 res = prepare_binprm(&bprm); 819 820 if (res <= (unsigned long)-4096) 821 res = load_flat_file(&bprm, libs, id, NULL); 822 if (bprm.file) { 823 allow_write_access(bprm.file); 824 fput(bprm.file); 825 bprm.file = NULL; 826 } 827 return(res); 828} 829 830#endif /* CONFIG_BINFMT_SHARED_FLAT */ 831/****************************************************************************/ 832 833/* 834 * These are the functions used to load flat style executables and shared 835 * libraries. There is no binary dependent code anywhere else. 836 */ 837 838static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) 839{ 840 struct lib_info libinfo; 841 unsigned long p = bprm->p; 842 unsigned long stack_len; 843 unsigned long start_addr; 844 unsigned long *sp; 845 int res; 846 int i, j; 847 848 memset(&libinfo, 0, sizeof(libinfo)); 849 /* 850 * We have to add the size of our arguments to our stack size 851 * otherwise it's too easy for users to create stack overflows 852 * by passing in a huge argument list. And yes, we have to be 853 * pedantic and include space for the argv/envp array as it may have 854 * a lot of entries. 855 */ 856#define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *)) 857 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */ 858 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ 859 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ 860 861 862 res = load_flat_file(bprm, &libinfo, 0, &stack_len); 863 if (res > (unsigned long)-4096) 864 return res; 865 866 /* Update data segment pointers for all libraries */ 867 for (i=0; i<MAX_SHARED_LIBS; i++) 868 if (libinfo.lib_list[i].loaded) 869 for (j=0; j<MAX_SHARED_LIBS; j++) 870 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] = 871 (libinfo.lib_list[j].loaded)? 872 libinfo.lib_list[j].start_data:UNLOADED_LIB; 873 874 compute_creds(bprm); 875 current->flags &= ~PF_FORKNOEXEC; 876 877 set_binfmt(&flat_format); 878 879 p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; 880 DBG_FLT("p=%x\n", (int)p); 881 882 /* copy the arg pages onto the stack, this could be more efficient :-) */ 883 for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--) 884 * (char *) --p = 885 ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE]; 886 887 sp = (unsigned long *) create_flat_tables(p, bprm); 888 889 /* Fake some return addresses to ensure the call chain will 890 * initialise library in order for us. We are required to call 891 * lib 1 first, then 2, ... and finally the main program (id 0). 892 */ 893 start_addr = libinfo.lib_list[0].entry; 894 895#ifdef CONFIG_BINFMT_SHARED_FLAT 896 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 897 if (libinfo.lib_list[i].loaded) { 898 /* Push previos first to call address */ 899 --sp; put_user(start_addr, sp); 900 start_addr = libinfo.lib_list[i].entry; 901 } 902 } 903#endif 904 905 /* Stash our initial stack pointer into the mm structure */ 906 current->mm->start_stack = (unsigned long )sp; 907 908 909 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n", 910 (int)regs, (int)start_addr, (int)current->mm->start_stack); 911 912 start_thread(regs, start_addr, current->mm->start_stack); 913 914 if (current->ptrace & PT_PTRACED) 915 send_sig(SIGTRAP, current, 0); 916 917 return 0; 918} 919 920/****************************************************************************/ 921 922static int __init init_flat_binfmt(void) 923{ 924 return register_binfmt(&flat_format); 925} 926 927static void __exit exit_flat_binfmt(void) 928{ 929 unregister_binfmt(&flat_format); 930} 931 932/****************************************************************************/ 933 934core_initcall(init_flat_binfmt); 935module_exit(exit_flat_binfmt); 936 937/****************************************************************************/ 938