1 // SPDX-License-Identifier: GPL-2.0 2 /****************************************************************************/ 3 /* 4 * linux/fs/binfmt_flat.c 5 * 6 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com> 7 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com> 8 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com> 9 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com> 10 * based heavily on: 11 * 12 * linux/fs/binfmt_aout.c: 13 * Copyright (C) 1991, 1992, 1996 Linus Torvalds 14 * linux/fs/binfmt_flat.c for 2.0 kernel 15 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com> 16 * JAN/99 -- coded full program relocation (gerg@snapgear.com) 17 */ 18 19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 20 21 #include <linux/kernel.h> 22 #include <linux/sched.h> 23 #include <linux/sched/task_stack.h> 24 #include <linux/mm.h> 25 #include <linux/mman.h> 26 #include <linux/errno.h> 27 #include <linux/signal.h> 28 #include <linux/string.h> 29 #include <linux/fs.h> 30 #include <linux/file.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/uaccess.h> 39 #include <linux/vmalloc.h> 40 41 #include <asm/byteorder.h> 42 #include <asm/unaligned.h> 43 #include <asm/cacheflush.h> 44 #include <asm/page.h> 45 #include <asm/flat.h> 46 47 #ifndef flat_get_relocate_addr 48 #define flat_get_relocate_addr(rel) (rel) 49 #endif 50 51 /****************************************************************************/ 52 53 /* 54 * User data (data section and bss) needs to be aligned. 55 * We pick 0x20 here because it is the max value elf2flt has always 56 * used in producing FLAT files, and because it seems to be large 57 * enough to make all the gcc alignment related tests happy. 58 */ 59 #define FLAT_DATA_ALIGN (0x20) 60 61 /* 62 * User data (stack) also needs to be aligned. 63 * Here we can be a bit looser than the data sections since this 64 * needs to only meet arch ABI requirements. 65 */ 66 #define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN) 67 68 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */ 69 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */ 70 71 #ifdef CONFIG_BINFMT_SHARED_FLAT 72 #define MAX_SHARED_LIBS (4) 73 #else 74 #define MAX_SHARED_LIBS (1) 75 #endif 76 77 #ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET 78 #define DATA_START_OFFSET_WORDS (0) 79 #else 80 #define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) 81 #endif 82 83 struct lib_info { 84 struct { 85 unsigned long start_code; /* Start of text segment */ 86 unsigned long start_data; /* Start of data segment */ 87 unsigned long start_brk; /* End of data segment */ 88 unsigned long text_len; /* Length of text segment */ 89 unsigned long entry; /* Start address for this module */ 90 unsigned long build_date; /* When this one was compiled */ 91 bool loaded; /* Has this library been loaded? */ 92 } lib_list[MAX_SHARED_LIBS]; 93 }; 94 95 #ifdef CONFIG_BINFMT_SHARED_FLAT 96 static int load_flat_shared_library(int id, struct lib_info *p); 97 #endif 98 99 static int load_flat_binary(struct linux_binprm *); 100 static int flat_core_dump(struct coredump_params *cprm); 101 102 static struct linux_binfmt flat_format = { 103 .module = THIS_MODULE, 104 .load_binary = load_flat_binary, 105 .core_dump = flat_core_dump, 106 .min_coredump = PAGE_SIZE 107 }; 108 109 /****************************************************************************/ 110 /* 111 * Routine writes a core dump image in the current directory. 112 * Currently only a stub-function. 113 */ 114 115 static int flat_core_dump(struct coredump_params *cprm) 116 { 117 pr_warn("Process %s:%d received signr %d and should have core dumped\n", 118 current->comm, current->pid, cprm->siginfo->si_signo); 119 return 1; 120 } 121 122 /****************************************************************************/ 123 /* 124 * create_flat_tables() parses the env- and arg-strings in new user 125 * memory and creates the pointer tables from them, and puts their 126 * addresses on the "stack", recording the new stack pointer value. 127 */ 128 129 static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start) 130 { 131 char __user *p; 132 unsigned long __user *sp; 133 long i, len; 134 135 p = (char __user *)arg_start; 136 sp = (unsigned long __user *)current->mm->start_stack; 137 138 sp -= bprm->envc + 1; 139 sp -= bprm->argc + 1; 140 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) 141 sp -= 2; /* argvp + envp */ 142 sp -= 1; /* &argc */ 143 144 current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN; 145 sp = (unsigned long __user *)current->mm->start_stack; 146 147 if (put_user(bprm->argc, sp++)) 148 return -EFAULT; 149 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) { 150 unsigned long argv, envp; 151 argv = (unsigned long)(sp + 2); 152 envp = (unsigned long)(sp + 2 + bprm->argc + 1); 153 if (put_user(argv, sp++) || put_user(envp, sp++)) 154 return -EFAULT; 155 } 156 157 current->mm->arg_start = (unsigned long)p; 158 for (i = bprm->argc; i > 0; i--) { 159 if (put_user((unsigned long)p, sp++)) 160 return -EFAULT; 161 len = strnlen_user(p, MAX_ARG_STRLEN); 162 if (!len || len > MAX_ARG_STRLEN) 163 return -EINVAL; 164 p += len; 165 } 166 if (put_user(0, sp++)) 167 return -EFAULT; 168 current->mm->arg_end = (unsigned long)p; 169 170 current->mm->env_start = (unsigned long) p; 171 for (i = bprm->envc; i > 0; i--) { 172 if (put_user((unsigned long)p, sp++)) 173 return -EFAULT; 174 len = strnlen_user(p, MAX_ARG_STRLEN); 175 if (!len || len > MAX_ARG_STRLEN) 176 return -EINVAL; 177 p += len; 178 } 179 if (put_user(0, sp++)) 180 return -EFAULT; 181 current->mm->env_end = (unsigned long)p; 182 183 return 0; 184 } 185 186 /****************************************************************************/ 187 188 #ifdef CONFIG_BINFMT_ZFLAT 189 190 #include <linux/zlib.h> 191 192 #define LBUFSIZE 4000 193 194 /* gzip flag byte */ 195 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ 196 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */ 197 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */ 198 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */ 199 #define COMMENT 0x10 /* bit 4 set: file comment present */ 200 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */ 201 #define RESERVED 0xC0 /* bit 6,7: reserved */ 202 203 static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst, 204 long len, int fd) 205 { 206 unsigned char *buf; 207 z_stream strm; 208 int ret, retval; 209 210 pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len); 211 212 memset(&strm, 0, sizeof(strm)); 213 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL); 214 if (!strm.workspace) 215 return -ENOMEM; 216 217 buf = kmalloc(LBUFSIZE, GFP_KERNEL); 218 if (!buf) { 219 retval = -ENOMEM; 220 goto out_free; 221 } 222 223 /* Read in first chunk of data and parse gzip header. */ 224 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos); 225 226 strm.next_in = buf; 227 strm.avail_in = ret; 228 strm.total_in = 0; 229 230 retval = -ENOEXEC; 231 232 /* Check minimum size -- gzip header */ 233 if (ret < 10) { 234 pr_debug("file too small?\n"); 235 goto out_free_buf; 236 } 237 238 /* Check gzip magic number */ 239 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) { 240 pr_debug("unknown compression magic?\n"); 241 goto out_free_buf; 242 } 243 244 /* Check gzip method */ 245 if (buf[2] != 8) { 246 pr_debug("unknown compression method?\n"); 247 goto out_free_buf; 248 } 249 /* Check gzip flags */ 250 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) || 251 (buf[3] & RESERVED)) { 252 pr_debug("unknown flags?\n"); 253 goto out_free_buf; 254 } 255 256 ret = 10; 257 if (buf[3] & EXTRA_FIELD) { 258 ret += 2 + buf[10] + (buf[11] << 8); 259 if (unlikely(ret >= LBUFSIZE)) { 260 pr_debug("buffer overflow (EXTRA)?\n"); 261 goto out_free_buf; 262 } 263 } 264 if (buf[3] & ORIG_NAME) { 265 while (ret < LBUFSIZE && buf[ret++] != 0) 266 ; 267 if (unlikely(ret == LBUFSIZE)) { 268 pr_debug("buffer overflow (ORIG_NAME)?\n"); 269 goto out_free_buf; 270 } 271 } 272 if (buf[3] & COMMENT) { 273 while (ret < LBUFSIZE && buf[ret++] != 0) 274 ; 275 if (unlikely(ret == LBUFSIZE)) { 276 pr_debug("buffer overflow (COMMENT)?\n"); 277 goto out_free_buf; 278 } 279 } 280 281 strm.next_in += ret; 282 strm.avail_in -= ret; 283 284 strm.next_out = dst; 285 strm.avail_out = len; 286 strm.total_out = 0; 287 288 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) { 289 pr_debug("zlib init failed?\n"); 290 goto out_free_buf; 291 } 292 293 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) { 294 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos); 295 if (ret <= 0) 296 break; 297 len -= ret; 298 299 strm.next_in = buf; 300 strm.avail_in = ret; 301 strm.total_in = 0; 302 } 303 304 if (ret < 0) { 305 pr_debug("decompression failed (%d), %s\n", 306 ret, strm.msg); 307 goto out_zlib; 308 } 309 310 retval = 0; 311 out_zlib: 312 zlib_inflateEnd(&strm); 313 out_free_buf: 314 kfree(buf); 315 out_free: 316 kfree(strm.workspace); 317 return retval; 318 } 319 320 #endif /* CONFIG_BINFMT_ZFLAT */ 321 322 /****************************************************************************/ 323 324 static unsigned long 325 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp) 326 { 327 unsigned long addr; 328 int id; 329 unsigned long start_brk; 330 unsigned long start_data; 331 unsigned long text_len; 332 unsigned long start_code; 333 334 #ifdef CONFIG_BINFMT_SHARED_FLAT 335 if (r == 0) 336 id = curid; /* Relocs of 0 are always self referring */ 337 else { 338 id = (r >> 24) & 0xff; /* Find ID for this reloc */ 339 r &= 0x00ffffff; /* Trim ID off here */ 340 } 341 if (id >= MAX_SHARED_LIBS) { 342 pr_err("reference 0x%lx to shared library %d", r, id); 343 goto failed; 344 } 345 if (curid != id) { 346 if (internalp) { 347 pr_err("reloc address 0x%lx not in same module " 348 "(%d != %d)", r, curid, id); 349 goto failed; 350 } else if (!p->lib_list[id].loaded && 351 load_flat_shared_library(id, p) < 0) { 352 pr_err("failed to load library %d", id); 353 goto failed; 354 } 355 /* Check versioning information (i.e. time stamps) */ 356 if (p->lib_list[id].build_date && p->lib_list[curid].build_date && 357 p->lib_list[curid].build_date < p->lib_list[id].build_date) { 358 pr_err("library %d is younger than %d", id, curid); 359 goto failed; 360 } 361 } 362 #else 363 id = 0; 364 #endif 365 366 start_brk = p->lib_list[id].start_brk; 367 start_data = p->lib_list[id].start_data; 368 start_code = p->lib_list[id].start_code; 369 text_len = p->lib_list[id].text_len; 370 371 if (r > start_brk - start_data + text_len) { 372 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)", 373 r, start_brk-start_data+text_len, text_len); 374 goto failed; 375 } 376 377 if (r < text_len) /* In text segment */ 378 addr = r + start_code; 379 else /* In data segment */ 380 addr = r - text_len + start_data; 381 382 /* Range checked already above so doing the range tests is redundant...*/ 383 return addr; 384 385 failed: 386 pr_cont(", killing %s!\n", current->comm); 387 send_sig(SIGSEGV, current, 0); 388 389 return RELOC_FAILED; 390 } 391 392 /****************************************************************************/ 393 394 #ifdef CONFIG_BINFMT_FLAT_OLD 395 static void old_reloc(unsigned long rl) 396 { 397 static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" }; 398 flat_v2_reloc_t r; 399 unsigned long __user *ptr; 400 unsigned long val; 401 402 r.value = rl; 403 #if defined(CONFIG_COLDFIRE) 404 ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset); 405 #else 406 ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset); 407 #endif 408 get_user(val, ptr); 409 410 pr_debug("Relocation of variable at DATASEG+%x " 411 "(address %p, currently %lx) into segment %s\n", 412 r.reloc.offset, ptr, val, segment[r.reloc.type]); 413 414 switch (r.reloc.type) { 415 case OLD_FLAT_RELOC_TYPE_TEXT: 416 val += current->mm->start_code; 417 break; 418 case OLD_FLAT_RELOC_TYPE_DATA: 419 val += current->mm->start_data; 420 break; 421 case OLD_FLAT_RELOC_TYPE_BSS: 422 val += current->mm->end_data; 423 break; 424 default: 425 pr_err("Unknown relocation type=%x\n", r.reloc.type); 426 break; 427 } 428 put_user(val, ptr); 429 430 pr_debug("Relocation became %lx\n", val); 431 } 432 #endif /* CONFIG_BINFMT_FLAT_OLD */ 433 434 /****************************************************************************/ 435 436 static int load_flat_file(struct linux_binprm *bprm, 437 struct lib_info *libinfo, int id, unsigned long *extra_stack) 438 { 439 struct flat_hdr *hdr; 440 unsigned long textpos, datapos, realdatastart; 441 u32 text_len, data_len, bss_len, stack_len, full_data, flags; 442 unsigned long len, memp, memp_size, extra, rlim; 443 __be32 __user *reloc; 444 u32 __user *rp; 445 int i, rev, relocs; 446 loff_t fpos; 447 unsigned long start_code, end_code; 448 ssize_t result; 449 int ret; 450 451 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ 452 453 text_len = ntohl(hdr->data_start); 454 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); 455 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); 456 stack_len = ntohl(hdr->stack_size); 457 if (extra_stack) { 458 stack_len += *extra_stack; 459 *extra_stack = stack_len; 460 } 461 relocs = ntohl(hdr->reloc_count); 462 flags = ntohl(hdr->flags); 463 rev = ntohl(hdr->rev); 464 full_data = data_len + relocs * sizeof(unsigned long); 465 466 if (strncmp(hdr->magic, "bFLT", 4)) { 467 /* 468 * Previously, here was a printk to tell people 469 * "BINFMT_FLAT: bad header magic". 470 * But for the kernel which also use ELF FD-PIC format, this 471 * error message is confusing. 472 * because a lot of people do not manage to produce good 473 */ 474 ret = -ENOEXEC; 475 goto err; 476 } 477 478 if (flags & FLAT_FLAG_KTRACE) 479 pr_info("Loading file: %s\n", bprm->filename); 480 481 #ifdef CONFIG_BINFMT_FLAT_OLD 482 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { 483 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n", 484 rev, FLAT_VERSION, OLD_FLAT_VERSION); 485 ret = -ENOEXEC; 486 goto err; 487 } 488 489 /* Don't allow old format executables to use shared libraries */ 490 if (rev == OLD_FLAT_VERSION && id != 0) { 491 pr_err("shared libraries are not available before rev 0x%lx\n", 492 FLAT_VERSION); 493 ret = -ENOEXEC; 494 goto err; 495 } 496 497 /* 498 * fix up the flags for the older format, there were all kinds 499 * of endian hacks, this only works for the simple cases 500 */ 501 if (rev == OLD_FLAT_VERSION && 502 (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM))) 503 flags = FLAT_FLAG_RAM; 504 505 #else /* CONFIG_BINFMT_FLAT_OLD */ 506 if (rev != FLAT_VERSION) { 507 pr_err("bad flat file version 0x%x (supported 0x%lx)\n", 508 rev, FLAT_VERSION); 509 ret = -ENOEXEC; 510 goto err; 511 } 512 #endif /* !CONFIG_BINFMT_FLAT_OLD */ 513 514 /* 515 * Make sure the header params are sane. 516 * 28 bits (256 MB) is way more than reasonable in this case. 517 * If some top bits are set we have probable binary corruption. 518 */ 519 if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) { 520 pr_err("bad header\n"); 521 ret = -ENOEXEC; 522 goto err; 523 } 524 525 #ifndef CONFIG_BINFMT_ZFLAT 526 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { 527 pr_err("Support for ZFLAT executables is not enabled.\n"); 528 ret = -ENOEXEC; 529 goto err; 530 } 531 #endif 532 533 /* 534 * Check initial limits. This avoids letting people circumvent 535 * size limits imposed on them by creating programs with large 536 * arrays in the data or bss. 537 */ 538 rlim = rlimit(RLIMIT_DATA); 539 if (rlim >= RLIM_INFINITY) 540 rlim = ~0; 541 if (data_len + bss_len > rlim) { 542 ret = -ENOMEM; 543 goto err; 544 } 545 546 /* Flush all traces of the currently running executable */ 547 if (id == 0) { 548 ret = begin_new_exec(bprm); 549 if (ret) 550 goto err; 551 552 /* OK, This is the point of no return */ 553 set_personality(PER_LINUX_32BIT); 554 setup_new_exec(bprm); 555 } 556 557 /* 558 * calculate the extra space we need to map in 559 */ 560 extra = max_t(unsigned long, bss_len + stack_len, 561 relocs * sizeof(unsigned long)); 562 563 /* 564 * there are a couple of cases here, the separate code/data 565 * case, and then the fully copied to RAM case which lumps 566 * it all together. 567 */ 568 if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { 569 /* 570 * this should give us a ROM ptr, but if it doesn't we don't 571 * really care 572 */ 573 pr_debug("ROM mapping of file (we hope)\n"); 574 575 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, 576 MAP_PRIVATE, 0); 577 if (!textpos || IS_ERR_VALUE(textpos)) { 578 ret = textpos; 579 if (!textpos) 580 ret = -ENOMEM; 581 pr_err("Unable to mmap process text, errno %d\n", ret); 582 goto err; 583 } 584 585 len = data_len + extra + 586 DATA_START_OFFSET_WORDS * sizeof(unsigned long); 587 len = PAGE_ALIGN(len); 588 realdatastart = vm_mmap(NULL, 0, len, 589 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); 590 591 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) { 592 ret = realdatastart; 593 if (!realdatastart) 594 ret = -ENOMEM; 595 pr_err("Unable to allocate RAM for process data, " 596 "errno %d\n", ret); 597 vm_munmap(textpos, text_len); 598 goto err; 599 } 600 datapos = ALIGN(realdatastart + 601 DATA_START_OFFSET_WORDS * sizeof(unsigned long), 602 FLAT_DATA_ALIGN); 603 604 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n", 605 data_len + bss_len + stack_len, datapos); 606 607 fpos = ntohl(hdr->data_start); 608 #ifdef CONFIG_BINFMT_ZFLAT 609 if (flags & FLAT_FLAG_GZDATA) { 610 result = decompress_exec(bprm, fpos, (char *)datapos, 611 full_data, 0); 612 } else 613 #endif 614 { 615 result = read_code(bprm->file, datapos, fpos, 616 full_data); 617 } 618 if (IS_ERR_VALUE(result)) { 619 ret = result; 620 pr_err("Unable to read data+bss, errno %d\n", ret); 621 vm_munmap(textpos, text_len); 622 vm_munmap(realdatastart, len); 623 goto err; 624 } 625 626 reloc = (__be32 __user *) 627 (datapos + (ntohl(hdr->reloc_start) - text_len)); 628 memp = realdatastart; 629 memp_size = len; 630 } else { 631 632 len = text_len + data_len + extra + 633 DATA_START_OFFSET_WORDS * sizeof(u32); 634 len = PAGE_ALIGN(len); 635 textpos = vm_mmap(NULL, 0, len, 636 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); 637 638 if (!textpos || IS_ERR_VALUE(textpos)) { 639 ret = textpos; 640 if (!textpos) 641 ret = -ENOMEM; 642 pr_err("Unable to allocate RAM for process text/data, " 643 "errno %d\n", ret); 644 goto err; 645 } 646 647 realdatastart = textpos + ntohl(hdr->data_start); 648 datapos = ALIGN(realdatastart + 649 DATA_START_OFFSET_WORDS * sizeof(u32), 650 FLAT_DATA_ALIGN); 651 652 reloc = (__be32 __user *) 653 (datapos + (ntohl(hdr->reloc_start) - text_len)); 654 memp = textpos; 655 memp_size = len; 656 #ifdef CONFIG_BINFMT_ZFLAT 657 /* 658 * load it all in and treat it like a RAM load from now on 659 */ 660 if (flags & FLAT_FLAG_GZIP) { 661 #ifndef CONFIG_MMU 662 result = decompress_exec(bprm, sizeof(struct flat_hdr), 663 (((char *)textpos) + sizeof(struct flat_hdr)), 664 (text_len + full_data 665 - sizeof(struct flat_hdr)), 666 0); 667 memmove((void *) datapos, (void *) realdatastart, 668 full_data); 669 #else 670 /* 671 * This is used on MMU systems mainly for testing. 672 * Let's use a kernel buffer to simplify things. 673 */ 674 long unz_text_len = text_len - sizeof(struct flat_hdr); 675 long unz_len = unz_text_len + full_data; 676 char *unz_data = vmalloc(unz_len); 677 if (!unz_data) { 678 result = -ENOMEM; 679 } else { 680 result = decompress_exec(bprm, sizeof(struct flat_hdr), 681 unz_data, unz_len, 0); 682 if (result == 0 && 683 (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr), 684 unz_data, unz_text_len) || 685 copy_to_user((void __user *)datapos, 686 unz_data + unz_text_len, full_data))) 687 result = -EFAULT; 688 vfree(unz_data); 689 } 690 #endif 691 } else if (flags & FLAT_FLAG_GZDATA) { 692 result = read_code(bprm->file, textpos, 0, text_len); 693 if (!IS_ERR_VALUE(result)) { 694 #ifndef CONFIG_MMU 695 result = decompress_exec(bprm, text_len, (char *) datapos, 696 full_data, 0); 697 #else 698 char *unz_data = vmalloc(full_data); 699 if (!unz_data) { 700 result = -ENOMEM; 701 } else { 702 result = decompress_exec(bprm, text_len, 703 unz_data, full_data, 0); 704 if (result == 0 && 705 copy_to_user((void __user *)datapos, 706 unz_data, full_data)) 707 result = -EFAULT; 708 vfree(unz_data); 709 } 710 #endif 711 } 712 } else 713 #endif /* CONFIG_BINFMT_ZFLAT */ 714 { 715 result = read_code(bprm->file, textpos, 0, text_len); 716 if (!IS_ERR_VALUE(result)) 717 result = read_code(bprm->file, datapos, 718 ntohl(hdr->data_start), 719 full_data); 720 } 721 if (IS_ERR_VALUE(result)) { 722 ret = result; 723 pr_err("Unable to read code+data+bss, errno %d\n", ret); 724 vm_munmap(textpos, text_len + data_len + extra + 725 DATA_START_OFFSET_WORDS * sizeof(u32)); 726 goto err; 727 } 728 } 729 730 start_code = textpos + sizeof(struct flat_hdr); 731 end_code = textpos + text_len; 732 text_len -= sizeof(struct flat_hdr); /* the real code len */ 733 734 /* The main program needs a little extra setup in the task structure */ 735 if (id == 0) { 736 current->mm->start_code = start_code; 737 current->mm->end_code = end_code; 738 current->mm->start_data = datapos; 739 current->mm->end_data = datapos + data_len; 740 /* 741 * set up the brk stuff, uses any slack left in data/bss/stack 742 * allocation. We put the brk after the bss (between the bss 743 * and stack) like other platforms. 744 * Userspace code relies on the stack pointer starting out at 745 * an address right at the end of a page. 746 */ 747 current->mm->start_brk = datapos + data_len + bss_len; 748 current->mm->brk = (current->mm->start_brk + 3) & ~3; 749 #ifndef CONFIG_MMU 750 current->mm->context.end_brk = memp + memp_size - stack_len; 751 #endif 752 } 753 754 if (flags & FLAT_FLAG_KTRACE) { 755 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n", 756 textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start)); 757 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n", 758 id ? "Lib" : "Load", bprm->filename, 759 start_code, end_code, datapos, datapos + data_len, 760 datapos + data_len, (datapos + data_len + bss_len + 3) & ~3); 761 } 762 763 /* Store the current module values into the global library structure */ 764 libinfo->lib_list[id].start_code = start_code; 765 libinfo->lib_list[id].start_data = datapos; 766 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len; 767 libinfo->lib_list[id].text_len = text_len; 768 libinfo->lib_list[id].loaded = 1; 769 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; 770 libinfo->lib_list[id].build_date = ntohl(hdr->build_date); 771 772 /* 773 * We just load the allocations into some temporary memory to 774 * help simplify all this mumbo jumbo 775 * 776 * We've got two different sections of relocation entries. 777 * The first is the GOT which resides at the beginning of the data segment 778 * and is terminated with a -1. This one can be relocated in place. 779 * The second is the extra relocation entries tacked after the image's 780 * data segment. These require a little more processing as the entry is 781 * really an offset into the image which contains an offset into the 782 * image. 783 */ 784 if (flags & FLAT_FLAG_GOTPIC) { 785 for (rp = (u32 __user *)datapos; ; rp++) { 786 u32 addr, rp_val; 787 if (get_user(rp_val, rp)) 788 return -EFAULT; 789 if (rp_val == 0xffffffff) 790 break; 791 if (rp_val) { 792 addr = calc_reloc(rp_val, libinfo, id, 0); 793 if (addr == RELOC_FAILED) { 794 ret = -ENOEXEC; 795 goto err; 796 } 797 if (put_user(addr, rp)) 798 return -EFAULT; 799 } 800 } 801 } 802 803 /* 804 * Now run through the relocation entries. 805 * We've got to be careful here as C++ produces relocatable zero 806 * entries in the constructor and destructor tables which are then 807 * tested for being not zero (which will always occur unless we're 808 * based from address zero). This causes an endless loop as __start 809 * is at zero. The solution used is to not relocate zero addresses. 810 * This has the negative side effect of not allowing a global data 811 * reference to be statically initialised to _stext (I've moved 812 * __start to address 4 so that is okay). 813 */ 814 if (rev > OLD_FLAT_VERSION) { 815 for (i = 0; i < relocs; i++) { 816 u32 addr, relval; 817 __be32 tmp; 818 819 /* 820 * Get the address of the pointer to be 821 * relocated (of course, the address has to be 822 * relocated first). 823 */ 824 if (get_user(tmp, reloc + i)) 825 return -EFAULT; 826 relval = ntohl(tmp); 827 addr = flat_get_relocate_addr(relval); 828 rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1); 829 if (rp == (u32 __user *)RELOC_FAILED) { 830 ret = -ENOEXEC; 831 goto err; 832 } 833 834 /* Get the pointer's value. */ 835 ret = flat_get_addr_from_rp(rp, relval, flags, &addr); 836 if (unlikely(ret)) 837 goto err; 838 839 if (addr != 0) { 840 /* 841 * Do the relocation. PIC relocs in the data section are 842 * already in target order 843 */ 844 if ((flags & FLAT_FLAG_GOTPIC) == 0) { 845 /* 846 * Meh, the same value can have a different 847 * byte order based on a flag.. 848 */ 849 addr = ntohl((__force __be32)addr); 850 } 851 addr = calc_reloc(addr, libinfo, id, 0); 852 if (addr == RELOC_FAILED) { 853 ret = -ENOEXEC; 854 goto err; 855 } 856 857 /* Write back the relocated pointer. */ 858 ret = flat_put_addr_at_rp(rp, addr, relval); 859 if (unlikely(ret)) 860 goto err; 861 } 862 } 863 #ifdef CONFIG_BINFMT_FLAT_OLD 864 } else { 865 for (i = 0; i < relocs; i++) { 866 __be32 relval; 867 if (get_user(relval, reloc + i)) 868 return -EFAULT; 869 old_reloc(ntohl(relval)); 870 } 871 #endif /* CONFIG_BINFMT_FLAT_OLD */ 872 } 873 874 flush_icache_user_range(start_code, end_code); 875 876 /* zero the BSS, BRK and stack areas */ 877 if (clear_user((void __user *)(datapos + data_len), bss_len + 878 (memp + memp_size - stack_len - /* end brk */ 879 libinfo->lib_list[id].start_brk) + /* start brk */ 880 stack_len)) 881 return -EFAULT; 882 883 return 0; 884 err: 885 return ret; 886 } 887 888 889 /****************************************************************************/ 890 #ifdef CONFIG_BINFMT_SHARED_FLAT 891 892 /* 893 * Load a shared library into memory. The library gets its own data 894 * segment (including bss) but not argv/argc/environ. 895 */ 896 897 static int load_flat_shared_library(int id, struct lib_info *libs) 898 { 899 /* 900 * This is a fake bprm struct; only the members "buf", "file" and 901 * "filename" are actually used. 902 */ 903 struct linux_binprm bprm; 904 int res; 905 char buf[16]; 906 loff_t pos = 0; 907 908 memset(&bprm, 0, sizeof(bprm)); 909 910 /* Create the file name */ 911 sprintf(buf, "/lib/lib%d.so", id); 912 913 /* Open the file up */ 914 bprm.filename = buf; 915 bprm.file = open_exec(bprm.filename); 916 res = PTR_ERR(bprm.file); 917 if (IS_ERR(bprm.file)) 918 return res; 919 920 res = kernel_read(bprm.file, bprm.buf, BINPRM_BUF_SIZE, &pos); 921 922 if (res >= 0) 923 res = load_flat_file(&bprm, libs, id, NULL); 924 925 allow_write_access(bprm.file); 926 fput(bprm.file); 927 928 return res; 929 } 930 931 #endif /* CONFIG_BINFMT_SHARED_FLAT */ 932 /****************************************************************************/ 933 934 /* 935 * These are the functions used to load flat style executables and shared 936 * libraries. There is no binary dependent code anywhere else. 937 */ 938 939 static int load_flat_binary(struct linux_binprm *bprm) 940 { 941 struct lib_info libinfo; 942 struct pt_regs *regs = current_pt_regs(); 943 unsigned long stack_len = 0; 944 unsigned long start_addr; 945 int res; 946 int i, j; 947 948 memset(&libinfo, 0, sizeof(libinfo)); 949 950 /* 951 * We have to add the size of our arguments to our stack size 952 * otherwise it's too easy for users to create stack overflows 953 * by passing in a huge argument list. And yes, we have to be 954 * pedantic and include space for the argv/envp array as it may have 955 * a lot of entries. 956 */ 957 #ifndef CONFIG_MMU 958 stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */ 959 #endif 960 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ 961 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ 962 stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN); 963 964 res = load_flat_file(bprm, &libinfo, 0, &stack_len); 965 if (res < 0) 966 return res; 967 968 /* Update data segment pointers for all libraries */ 969 for (i = 0; i < MAX_SHARED_LIBS; i++) { 970 if (!libinfo.lib_list[i].loaded) 971 continue; 972 for (j = 0; j < MAX_SHARED_LIBS; j++) { 973 unsigned long val = libinfo.lib_list[j].loaded ? 974 libinfo.lib_list[j].start_data : UNLOADED_LIB; 975 unsigned long __user *p = (unsigned long __user *) 976 libinfo.lib_list[i].start_data; 977 p -= j + 1; 978 if (put_user(val, p)) 979 return -EFAULT; 980 } 981 } 982 983 set_binfmt(&flat_format); 984 985 #ifdef CONFIG_MMU 986 res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT); 987 if (!res) 988 res = create_flat_tables(bprm, bprm->p); 989 #else 990 /* Stash our initial stack pointer into the mm structure */ 991 current->mm->start_stack = 992 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; 993 pr_debug("sp=%lx\n", current->mm->start_stack); 994 995 /* copy the arg pages onto the stack */ 996 res = transfer_args_to_stack(bprm, ¤t->mm->start_stack); 997 if (!res) 998 res = create_flat_tables(bprm, current->mm->start_stack); 999 #endif 1000 if (res) 1001 return res; 1002 1003 /* Fake some return addresses to ensure the call chain will 1004 * initialise library in order for us. We are required to call 1005 * lib 1 first, then 2, ... and finally the main program (id 0). 1006 */ 1007 start_addr = libinfo.lib_list[0].entry; 1008 1009 #ifdef CONFIG_BINFMT_SHARED_FLAT 1010 for (i = MAX_SHARED_LIBS-1; i > 0; i--) { 1011 if (libinfo.lib_list[i].loaded) { 1012 /* Push previos first to call address */ 1013 unsigned long __user *sp; 1014 current->mm->start_stack -= sizeof(unsigned long); 1015 sp = (unsigned long __user *)current->mm->start_stack; 1016 if (put_user(start_addr, sp)) 1017 return -EFAULT; 1018 start_addr = libinfo.lib_list[i].entry; 1019 } 1020 } 1021 #endif 1022 1023 #ifdef FLAT_PLAT_INIT 1024 FLAT_PLAT_INIT(regs); 1025 #endif 1026 1027 finalize_exec(bprm); 1028 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n", 1029 regs, start_addr, current->mm->start_stack); 1030 start_thread(regs, start_addr, current->mm->start_stack); 1031 1032 return 0; 1033 } 1034 1035 /****************************************************************************/ 1036 1037 static int __init init_flat_binfmt(void) 1038 { 1039 register_binfmt(&flat_format); 1040 return 0; 1041 } 1042 core_initcall(init_flat_binfmt); 1043 1044 /****************************************************************************/ 1045