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