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