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 (stack, data section and bss) needs to be aligned 60 * for the same reasons as SLAB memory is, and to the same amount. 61 * Avoid duplicating architecture specific code by using the same 62 * macro as with SLAB allocation: 63 */ 64 #ifdef ARCH_SLAB_MINALIGN 65 #define FLAT_DATA_ALIGN (ARCH_SLAB_MINALIGN) 66 #else 67 #define FLAT_DATA_ALIGN (sizeof(void *)) 68 #endif 69 70 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 71 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 72 73 struct lib_info { 74 struct { 75 unsigned long start_code; /* Start of text segment */ 76 unsigned long start_data; /* Start of data segment */ 77 unsigned long start_brk; /* End of data segment */ 78 unsigned long text_len; /* Length of text segment */ 79 unsigned long entry; /* Start address for this module */ 80 unsigned long build_date; /* When this one was compiled */ 81 short loaded; /* Has this library been loaded? */ 82 } lib_list[MAX_SHARED_LIBS]; 83 }; 84 85 #ifdef CONFIG_BINFMT_SHARED_FLAT 86 static int load_flat_shared_library(int id, struct lib_info *p); 87 #endif 88 89 static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs); 90 static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit); 91 92 static struct linux_binfmt flat_format = { 93 .module = THIS_MODULE, 94 .load_binary = load_flat_binary, 95 .core_dump = flat_core_dump, 96 .min_coredump = PAGE_SIZE 97 }; 98 99 /****************************************************************************/ 100 /* 101 * Routine writes a core dump image in the current directory. 102 * Currently only a stub-function. 103 */ 104 105 static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit) 106 { 107 printk("Process %s:%d received signr %d and should have core dumped\n", 108 current->comm, current->pid, (int) signr); 109 return(1); 110 } 111 112 /****************************************************************************/ 113 /* 114 * create_flat_tables() parses the env- and arg-strings in new user 115 * memory and creates the pointer tables from them, and puts their 116 * addresses on the "stack", returning the new stack pointer value. 117 */ 118 119 static unsigned long create_flat_tables( 120 unsigned long pp, 121 struct linux_binprm * bprm) 122 { 123 unsigned long *argv,*envp; 124 unsigned long * sp; 125 char * p = (char*)pp; 126 int argc = bprm->argc; 127 int envc = bprm->envc; 128 char uninitialized_var(dummy); 129 130 sp = (unsigned long *)p; 131 sp -= (envc + argc + 2) + 1 + (flat_argvp_envp_on_stack() ? 2 : 0); 132 sp = (unsigned long *) ((unsigned long)sp & -FLAT_DATA_ALIGN); 133 argv = sp + 1 + (flat_argvp_envp_on_stack() ? 2 : 0); 134 envp = argv + (argc + 1); 135 136 if (flat_argvp_envp_on_stack()) { 137 put_user((unsigned long) envp, sp + 2); 138 put_user((unsigned long) argv, sp + 1); 139 } 140 141 put_user(argc, sp); 142 current->mm->arg_start = (unsigned long) p; 143 while (argc-->0) { 144 put_user((unsigned long) p, argv++); 145 do { 146 get_user(dummy, p); p++; 147 } while (dummy); 148 } 149 put_user((unsigned long) NULL, argv); 150 current->mm->arg_end = current->mm->env_start = (unsigned long) p; 151 while (envc-->0) { 152 put_user((unsigned long)p, envp); envp++; 153 do { 154 get_user(dummy, p); p++; 155 } while (dummy); 156 } 157 put_user((unsigned long) NULL, envp); 158 current->mm->env_end = (unsigned long) p; 159 return (unsigned long)sp; 160 } 161 162 /****************************************************************************/ 163 164 #ifdef CONFIG_BINFMT_ZFLAT 165 166 #include <linux/zlib.h> 167 168 #define LBUFSIZE 4000 169 170 /* gzip flag byte */ 171 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 172 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 173 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 174 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 175 #define COMMENT 0x10 /* bit 4 set: file comment present */ 176 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 177 #define RESERVED 0xC0 /* bit 6,7: reserved */ 178 179 static int decompress_exec( 180 struct linux_binprm *bprm, 181 unsigned long offset, 182 char *dst, 183 long len, 184 int fd) 185 { 186 unsigned char *buf; 187 z_stream strm; 188 loff_t fpos; 189 int ret, retval; 190 191 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len); 192 193 memset(&strm, 0, sizeof(strm)); 194 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 195 if (strm.workspace == NULL) { 196 DBG_FLT("binfmt_flat: no memory for decompress workspace\n"); 197 return -ENOMEM; 198 } 199 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 200 if (buf == NULL) { 201 DBG_FLT("binfmt_flat: no memory for read buffer\n"); 202 retval = -ENOMEM; 203 goto out_free; 204 } 205 206 /* Read in first chunk of data and parse gzip header. */ 207 fpos = offset; 208 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 209 210 strm.next_in = buf; 211 strm.avail_in = ret; 212 strm.total_in = 0; 213 214 retval = -ENOEXEC; 215 216 /* Check minimum size -- gzip header */ 217 if (ret < 10) { 218 DBG_FLT("binfmt_flat: file too small?\n"); 219 goto out_free_buf; 220 } 221 222 /* Check gzip magic number */ 223 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 224 DBG_FLT("binfmt_flat: unknown compression magic?\n"); 225 goto out_free_buf; 226 } 227 228 /* Check gzip method */ 229 if (buf[2] != 8) { 230 DBG_FLT("binfmt_flat: unknown compression method?\n"); 231 goto out_free_buf; 232 } 233 /* Check gzip flags */ 234 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 235 (buf[3] & RESERVED)) { 236 DBG_FLT("binfmt_flat: unknown flags?\n"); 237 goto out_free_buf; 238 } 239 240 ret = 10; 241 if (buf[3] & EXTRA_FIELD) { 242 ret += 2 + buf[10] + (buf[11] << 8); 243 if (unlikely(LBUFSIZE <= ret)) { 244 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n"); 245 goto out_free_buf; 246 } 247 } 248 if (buf[3] & ORIG_NAME) { 249 while (ret < LBUFSIZE && buf[ret++] != 0) 250 ; 251 if (unlikely(LBUFSIZE == ret)) { 252 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n"); 253 goto out_free_buf; 254 } 255 } 256 if (buf[3] & COMMENT) { 257 while (ret < LBUFSIZE && buf[ret++] != 0) 258 ; 259 if (unlikely(LBUFSIZE == ret)) { 260 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n"); 261 goto out_free_buf; 262 } 263 } 264 265 strm.next_in += ret; 266 strm.avail_in -= ret; 267 268 strm.next_out = dst; 269 strm.avail_out = len; 270 strm.total_out = 0; 271 272 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 273 DBG_FLT("binfmt_flat: zlib init failed?\n"); 274 goto out_free_buf; 275 } 276 277 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 278 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos); 279 if (ret <= 0) 280 break; 281 if (ret >= (unsigned long) -4096) 282 break; 283 len -= ret; 284 285 strm.next_in = buf; 286 strm.avail_in = ret; 287 strm.total_in = 0; 288 } 289 290 if (ret < 0) { 291 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n", 292 ret, strm.msg); 293 goto out_zlib; 294 } 295 296 retval = 0; 297 out_zlib: 298 zlib_inflateEnd(&strm); 299 out_free_buf: 300 kfree(buf); 301 out_free: 302 kfree(strm.workspace); 303 return retval; 304 } 305 306 #endif /* CONFIG_BINFMT_ZFLAT */ 307 308 /****************************************************************************/ 309 310 static unsigned long 311 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp) 312 { 313 unsigned long addr; 314 int id; 315 unsigned long start_brk; 316 unsigned long start_data; 317 unsigned long text_len; 318 unsigned long start_code; 319 320 #ifdef CONFIG_BINFMT_SHARED_FLAT 321 if (r == 0) 322 id = curid; /* Relocs of 0 are always self referring */ 323 else { 324 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 325 r &= 0x00ffffff; /* Trim ID off here */ 326 } 327 if (id >= MAX_SHARED_LIBS) { 328 printk("BINFMT_FLAT: reference 0x%x to shared library %d", 329 (unsigned) r, id); 330 goto failed; 331 } 332 if (curid != id) { 333 if (internalp) { 334 printk("BINFMT_FLAT: reloc address 0x%x not in same module " 335 "(%d != %d)", (unsigned) r, curid, id); 336 goto failed; 337 } else if ( ! p->lib_list[id].loaded && 338 load_flat_shared_library(id, p) > (unsigned long) -4096) { 339 printk("BINFMT_FLAT: failed to load library %d", id); 340 goto failed; 341 } 342 /* Check versioning information (i.e. time stamps) */ 343 if (p->lib_list[id].build_date && p->lib_list[curid].build_date && 344 p->lib_list[curid].build_date < p->lib_list[id].build_date) { 345 printk("BINFMT_FLAT: library %d is younger than %d", id, curid); 346 goto failed; 347 } 348 } 349 #else 350 id = 0; 351 #endif 352 353 start_brk = p->lib_list[id].start_brk; 354 start_data = p->lib_list[id].start_data; 355 start_code = p->lib_list[id].start_code; 356 text_len = p->lib_list[id].text_len; 357 358 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) { 359 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)", 360 (int) r,(int)(start_brk-start_code),(int)text_len); 361 goto failed; 362 } 363 364 if (r < text_len) /* In text segment */ 365 addr = r + start_code; 366 else /* In data segment */ 367 addr = r - text_len + start_data; 368 369 /* Range checked already above so doing the range tests is redundant...*/ 370 return(addr); 371 372 failed: 373 printk(", killing %s!\n", current->comm); 374 send_sig(SIGSEGV, current, 0); 375 376 return RELOC_FAILED; 377 } 378 379 /****************************************************************************/ 380 381 void old_reloc(unsigned long rl) 382 { 383 #ifdef DEBUG 384 char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 385 #endif 386 flat_v2_reloc_t r; 387 unsigned long *ptr; 388 389 r.value = rl; 390 #if defined(CONFIG_COLDFIRE) 391 ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset); 392 #else 393 ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset); 394 #endif 395 396 #ifdef DEBUG 397 printk("Relocation of variable at DATASEG+%x " 398 "(address %p, currently %x) into segment %s\n", 399 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]); 400 #endif 401 402 switch (r.reloc.type) { 403 case OLD_FLAT_RELOC_TYPE_TEXT: 404 *ptr += current->mm->start_code; 405 break; 406 case OLD_FLAT_RELOC_TYPE_DATA: 407 *ptr += current->mm->start_data; 408 break; 409 case OLD_FLAT_RELOC_TYPE_BSS: 410 *ptr += current->mm->end_data; 411 break; 412 default: 413 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type); 414 break; 415 } 416 417 #ifdef DEBUG 418 printk("Relocation became %x\n", (int)*ptr); 419 #endif 420 } 421 422 /****************************************************************************/ 423 424 static int load_flat_file(struct linux_binprm * bprm, 425 struct lib_info *libinfo, int id, unsigned long *extra_stack) 426 { 427 struct flat_hdr * hdr; 428 unsigned long textpos = 0, datapos = 0, result; 429 unsigned long realdatastart = 0; 430 unsigned long text_len, data_len, bss_len, stack_len, flags; 431 unsigned long len, memp = 0; 432 unsigned long memp_size, extra, rlim; 433 unsigned long *reloc = 0, *rp; 434 struct inode *inode; 435 int i, rev, relocs = 0; 436 loff_t fpos; 437 unsigned long start_code, end_code; 438 int ret; 439 440 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 441 inode = bprm->file->f_path.dentry->d_inode; 442 443 text_len = ntohl(hdr->data_start); 444 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 445 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 446 stack_len = ntohl(hdr->stack_size); 447 if (extra_stack) { 448 stack_len += *extra_stack; 449 *extra_stack = stack_len; 450 } 451 relocs = ntohl(hdr->reloc_count); 452 flags = ntohl(hdr->flags); 453 rev = ntohl(hdr->rev); 454 455 if (strncmp(hdr->magic, "bFLT", 4)) { 456 /* 457 * Previously, here was a printk to tell people 458 * "BINFMT_FLAT: bad header magic". 459 * But for the kernel which also use ELF FD-PIC format, this 460 * error message is confusing. 461 * because a lot of people do not manage to produce good 462 */ 463 ret = -ENOEXEC; 464 goto err; 465 } 466 467 if (flags & FLAT_FLAG_KTRACE) 468 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename); 469 470 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 471 printk("BINFMT_FLAT: bad flat file version 0x%x (supported " 472 "0x%lx and 0x%lx)\n", 473 rev, FLAT_VERSION, OLD_FLAT_VERSION); 474 ret = -ENOEXEC; 475 goto err; 476 } 477 478 /* Don't allow old format executables to use shared libraries */ 479 if (rev == OLD_FLAT_VERSION && id != 0) { 480 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n", 481 (int) FLAT_VERSION); 482 ret = -ENOEXEC; 483 goto err; 484 } 485 486 /* 487 * fix up the flags for the older format, there were all kinds 488 * of endian hacks, this only works for the simple cases 489 */ 490 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags)) 491 flags = FLAT_FLAG_RAM; 492 493 #ifndef CONFIG_BINFMT_ZFLAT 494 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 495 printk("Support for ZFLAT executables is not enabled.\n"); 496 ret = -ENOEXEC; 497 goto err; 498 } 499 #endif 500 501 /* 502 * Check initial limits. This avoids letting people circumvent 503 * size limits imposed on them by creating programs with large 504 * arrays in the data or bss. 505 */ 506 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur; 507 if (rlim >= RLIM_INFINITY) 508 rlim = ~0; 509 if (data_len + bss_len > rlim) { 510 ret = -ENOMEM; 511 goto err; 512 } 513 514 /* Flush all traces of the currently running executable */ 515 if (id == 0) { 516 result = flush_old_exec(bprm); 517 if (result) { 518 ret = result; 519 goto err; 520 } 521 522 /* OK, This is the point of no return */ 523 set_personality(PER_LINUX_32BIT); 524 } 525 526 /* 527 * calculate the extra space we need to map in 528 */ 529 extra = max_t(unsigned long, bss_len + stack_len, 530 relocs * sizeof(unsigned long)); 531 532 /* 533 * there are a couple of cases here, the separate code/data 534 * case, and then the fully copied to RAM case which lumps 535 * it all together. 536 */ 537 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) { 538 /* 539 * this should give us a ROM ptr, but if it doesn't we don't 540 * really care 541 */ 542 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n"); 543 544 down_write(¤t->mm->mmap_sem); 545 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, 546 MAP_PRIVATE|MAP_EXECUTABLE, 0); 547 up_write(¤t->mm->mmap_sem); 548 if (!textpos || textpos >= (unsigned long) -4096) { 549 if (!textpos) 550 textpos = (unsigned long) -ENOMEM; 551 printk("Unable to mmap process text, errno %d\n", (int)-textpos); 552 ret = textpos; 553 goto err; 554 } 555 556 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 557 len = PAGE_ALIGN(len); 558 down_write(¤t->mm->mmap_sem); 559 realdatastart = do_mmap(0, 0, len, 560 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); 561 up_write(¤t->mm->mmap_sem); 562 563 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) { 564 if (!realdatastart) 565 realdatastart = (unsigned long) -ENOMEM; 566 printk("Unable to allocate RAM for process data, errno %d\n", 567 (int)-realdatastart); 568 do_munmap(current->mm, textpos, text_len); 569 ret = realdatastart; 570 goto err; 571 } 572 datapos = ALIGN(realdatastart + 573 MAX_SHARED_LIBS * sizeof(unsigned long), 574 FLAT_DATA_ALIGN); 575 576 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n", 577 (int)(data_len + bss_len + stack_len), (int)datapos); 578 579 fpos = ntohl(hdr->data_start); 580 #ifdef CONFIG_BINFMT_ZFLAT 581 if (flags & FLAT_FLAG_GZDATA) { 582 result = decompress_exec(bprm, fpos, (char *) datapos, 583 data_len + (relocs * sizeof(unsigned long)), 0); 584 } else 585 #endif 586 { 587 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 588 data_len + (relocs * sizeof(unsigned long)), &fpos); 589 } 590 if (result >= (unsigned long)-4096) { 591 printk("Unable to read data+bss, errno %d\n", (int)-result); 592 do_munmap(current->mm, textpos, text_len); 593 do_munmap(current->mm, realdatastart, data_len + extra); 594 ret = result; 595 goto err; 596 } 597 598 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len)); 599 memp = realdatastart; 600 memp_size = len; 601 } else { 602 603 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long); 604 len = PAGE_ALIGN(len); 605 down_write(¤t->mm->mmap_sem); 606 textpos = do_mmap(0, 0, len, 607 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); 608 up_write(¤t->mm->mmap_sem); 609 610 if (!textpos || textpos >= (unsigned long) -4096) { 611 if (!textpos) 612 textpos = (unsigned long) -ENOMEM; 613 printk("Unable to allocate RAM for process text/data, errno %d\n", 614 (int)-textpos); 615 ret = textpos; 616 goto err; 617 } 618 619 realdatastart = textpos + ntohl(hdr->data_start); 620 datapos = ALIGN(realdatastart + 621 MAX_SHARED_LIBS * sizeof(unsigned long), 622 FLAT_DATA_ALIGN); 623 624 reloc = (unsigned long *) 625 (datapos + (ntohl(hdr->reloc_start) - text_len)); 626 memp = textpos; 627 memp_size = len; 628 #ifdef CONFIG_BINFMT_ZFLAT 629 /* 630 * load it all in and treat it like a RAM load from now on 631 */ 632 if (flags & FLAT_FLAG_GZIP) { 633 result = decompress_exec(bprm, sizeof (struct flat_hdr), 634 (((char *) textpos) + sizeof (struct flat_hdr)), 635 (text_len + data_len + (relocs * sizeof(unsigned long)) 636 - sizeof (struct flat_hdr)), 637 0); 638 memmove((void *) datapos, (void *) realdatastart, 639 data_len + (relocs * sizeof(unsigned long))); 640 } else if (flags & FLAT_FLAG_GZDATA) { 641 fpos = 0; 642 result = bprm->file->f_op->read(bprm->file, 643 (char *) textpos, text_len, &fpos); 644 if (result < (unsigned long) -4096) 645 result = decompress_exec(bprm, text_len, (char *) datapos, 646 data_len + (relocs * sizeof(unsigned long)), 0); 647 } 648 else 649 #endif 650 { 651 fpos = 0; 652 result = bprm->file->f_op->read(bprm->file, 653 (char *) textpos, text_len, &fpos); 654 if (result < (unsigned long) -4096) { 655 fpos = ntohl(hdr->data_start); 656 result = bprm->file->f_op->read(bprm->file, (char *) datapos, 657 data_len + (relocs * sizeof(unsigned long)), &fpos); 658 } 659 } 660 if (result >= (unsigned long)-4096) { 661 printk("Unable to read code+data+bss, errno %d\n",(int)-result); 662 do_munmap(current->mm, textpos, text_len + data_len + extra + 663 MAX_SHARED_LIBS * sizeof(unsigned long)); 664 ret = result; 665 goto err; 666 } 667 } 668 669 if (flags & FLAT_FLAG_KTRACE) 670 printk("Mapping is %x, Entry point is %x, data_start is %x\n", 671 (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start)); 672 673 /* The main program needs a little extra setup in the task structure */ 674 start_code = textpos + sizeof (struct flat_hdr); 675 end_code = textpos + text_len; 676 if (id == 0) { 677 current->mm->start_code = start_code; 678 current->mm->end_code = end_code; 679 current->mm->start_data = datapos; 680 current->mm->end_data = datapos + data_len; 681 /* 682 * set up the brk stuff, uses any slack left in data/bss/stack 683 * allocation. We put the brk after the bss (between the bss 684 * and stack) like other platforms. 685 * Userspace code relies on the stack pointer starting out at 686 * an address right at the end of a page. 687 */ 688 current->mm->start_brk = datapos + data_len + bss_len; 689 current->mm->brk = (current->mm->start_brk + 3) & ~3; 690 current->mm->context.end_brk = memp + memp_size - stack_len; 691 } 692 693 if (flags & FLAT_FLAG_KTRACE) 694 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n", 695 id ? "Lib" : "Load", bprm->filename, 696 (int) start_code, (int) end_code, 697 (int) datapos, 698 (int) (datapos + data_len), 699 (int) (datapos + data_len), 700 (int) (((datapos + data_len + bss_len) + 3) & ~3)); 701 702 text_len -= sizeof(struct flat_hdr); /* the real code len */ 703 704 /* Store the current module values into the global library structure */ 705 libinfo->lib_list[id].start_code = start_code; 706 libinfo->lib_list[id].start_data = datapos; 707 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len; 708 libinfo->lib_list[id].text_len = text_len; 709 libinfo->lib_list[id].loaded = 1; 710 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 711 libinfo->lib_list[id].build_date = ntohl(hdr->build_date); 712 713 /* 714 * We just load the allocations into some temporary memory to 715 * help simplify all this mumbo jumbo 716 * 717 * We've got two different sections of relocation entries. 718 * The first is the GOT which resides at the begining of the data segment 719 * and is terminated with a -1. This one can be relocated in place. 720 * The second is the extra relocation entries tacked after the image's 721 * data segment. These require a little more processing as the entry is 722 * really an offset into the image which contains an offset into the 723 * image. 724 */ 725 if (flags & FLAT_FLAG_GOTPIC) { 726 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) { 727 unsigned long addr; 728 if (*rp) { 729 addr = calc_reloc(*rp, libinfo, id, 0); 730 if (addr == RELOC_FAILED) { 731 ret = -ENOEXEC; 732 goto err; 733 } 734 *rp = addr; 735 } 736 } 737 } 738 739 /* 740 * Now run through the relocation entries. 741 * We've got to be careful here as C++ produces relocatable zero 742 * entries in the constructor and destructor tables which are then 743 * tested for being not zero (which will always occur unless we're 744 * based from address zero). This causes an endless loop as __start 745 * is at zero. The solution used is to not relocate zero addresses. 746 * This has the negative side effect of not allowing a global data 747 * reference to be statically initialised to _stext (I've moved 748 * __start to address 4 so that is okay). 749 */ 750 if (rev > OLD_FLAT_VERSION) { 751 unsigned long persistent = 0; 752 for (i=0; i < relocs; i++) { 753 unsigned long addr, relval; 754 755 /* Get the address of the pointer to be 756 relocated (of course, the address has to be 757 relocated first). */ 758 relval = ntohl(reloc[i]); 759 if (flat_set_persistent (relval, &persistent)) 760 continue; 761 addr = flat_get_relocate_addr(relval); 762 rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1); 763 if (rp == (unsigned long *)RELOC_FAILED) { 764 ret = -ENOEXEC; 765 goto err; 766 } 767 768 /* Get the pointer's value. */ 769 addr = flat_get_addr_from_rp(rp, relval, flags, 770 &persistent); 771 if (addr != 0) { 772 /* 773 * Do the relocation. PIC relocs in the data section are 774 * already in target order 775 */ 776 if ((flags & FLAT_FLAG_GOTPIC) == 0) 777 addr = ntohl(addr); 778 addr = calc_reloc(addr, libinfo, id, 0); 779 if (addr == RELOC_FAILED) { 780 ret = -ENOEXEC; 781 goto err; 782 } 783 784 /* Write back the relocated pointer. */ 785 flat_put_addr_at_rp(rp, addr, relval); 786 } 787 } 788 } else { 789 for (i=0; i < relocs; i++) 790 old_reloc(ntohl(reloc[i])); 791 } 792 793 flush_icache_range(start_code, end_code); 794 795 /* zero the BSS, BRK and stack areas */ 796 memset((void*)(datapos + data_len), 0, bss_len + 797 (memp + memp_size - stack_len - /* end brk */ 798 libinfo->lib_list[id].start_brk) + /* start brk */ 799 stack_len); 800 801 return 0; 802 err: 803 return ret; 804 } 805 806 807 /****************************************************************************/ 808 #ifdef CONFIG_BINFMT_SHARED_FLAT 809 810 /* 811 * Load a shared library into memory. The library gets its own data 812 * segment (including bss) but not argv/argc/environ. 813 */ 814 815 static int load_flat_shared_library(int id, struct lib_info *libs) 816 { 817 struct linux_binprm bprm; 818 int res; 819 char buf[16]; 820 821 /* Create the file name */ 822 sprintf(buf, "/lib/lib%d.so", id); 823 824 /* Open the file up */ 825 bprm.filename = buf; 826 bprm.file = open_exec(bprm.filename); 827 res = PTR_ERR(bprm.file); 828 if (IS_ERR(bprm.file)) 829 return res; 830 831 res = prepare_binprm(&bprm); 832 833 if (res <= (unsigned long)-4096) 834 res = load_flat_file(&bprm, libs, id, NULL); 835 if (bprm.file) { 836 allow_write_access(bprm.file); 837 fput(bprm.file); 838 bprm.file = NULL; 839 } 840 return(res); 841 } 842 843 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 844 /****************************************************************************/ 845 846 /* 847 * These are the functions used to load flat style executables and shared 848 * libraries. There is no binary dependent code anywhere else. 849 */ 850 851 static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs) 852 { 853 struct lib_info libinfo; 854 unsigned long p = bprm->p; 855 unsigned long stack_len; 856 unsigned long start_addr; 857 unsigned long *sp; 858 int res; 859 int i, j; 860 861 memset(&libinfo, 0, sizeof(libinfo)); 862 /* 863 * We have to add the size of our arguments to our stack size 864 * otherwise it's too easy for users to create stack overflows 865 * by passing in a huge argument list. And yes, we have to be 866 * pedantic and include space for the argv/envp array as it may have 867 * a lot of entries. 868 */ 869 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *)) 870 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */ 871 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ 872 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ 873 stack_len += FLAT_DATA_ALIGN - 1; /* reserve for upcoming alignment */ 874 875 res = load_flat_file(bprm, &libinfo, 0, &stack_len); 876 if (res > (unsigned long)-4096) 877 return res; 878 879 /* Update data segment pointers for all libraries */ 880 for (i=0; i<MAX_SHARED_LIBS; i++) 881 if (libinfo.lib_list[i].loaded) 882 for (j=0; j<MAX_SHARED_LIBS; j++) 883 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] = 884 (libinfo.lib_list[j].loaded)? 885 libinfo.lib_list[j].start_data:UNLOADED_LIB; 886 887 install_exec_creds(bprm); 888 current->flags &= ~PF_FORKNOEXEC; 889 890 set_binfmt(&flat_format); 891 892 p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; 893 DBG_FLT("p=%x\n", (int)p); 894 895 /* copy the arg pages onto the stack, this could be more efficient :-) */ 896 for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--) 897 * (char *) --p = 898 ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE]; 899 900 sp = (unsigned long *) create_flat_tables(p, bprm); 901 902 /* Fake some return addresses to ensure the call chain will 903 * initialise library in order for us. We are required to call 904 * lib 1 first, then 2, ... and finally the main program (id 0). 905 */ 906 start_addr = libinfo.lib_list[0].entry; 907 908 #ifdef CONFIG_BINFMT_SHARED_FLAT 909 for (i = MAX_SHARED_LIBS-1; i>0; i--) { 910 if (libinfo.lib_list[i].loaded) { 911 /* Push previos first to call address */ 912 --sp; put_user(start_addr, sp); 913 start_addr = libinfo.lib_list[i].entry; 914 } 915 } 916 #endif 917 918 /* Stash our initial stack pointer into the mm structure */ 919 current->mm->start_stack = (unsigned long )sp; 920 921 #ifdef FLAT_PLAT_INIT 922 FLAT_PLAT_INIT(regs); 923 #endif 924 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n", 925 (int)regs, (int)start_addr, (int)current->mm->start_stack); 926 927 start_thread(regs, start_addr, current->mm->start_stack); 928 929 return 0; 930 } 931 932 /****************************************************************************/ 933 934 static int __init init_flat_binfmt(void) 935 { 936 return register_binfmt(&flat_format); 937 } 938 939 /****************************************************************************/ 940 941 core_initcall(init_flat_binfmt); 942 943 /****************************************************************************/ 944