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