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 | #define MAX_SHARED_LIBS (1) |
72 | |
73 | #ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET |
74 | #define DATA_START_OFFSET_WORDS (0) |
75 | #else |
76 | #define DATA_START_OFFSET_WORDS (MAX_SHARED_LIBS) |
77 | #endif |
78 | |
79 | struct lib_info { |
80 | struct { |
81 | unsigned long start_code; /* Start of text segment */ |
82 | unsigned long start_data; /* Start of data segment */ |
83 | unsigned long start_brk; /* End of data segment */ |
84 | unsigned long text_len; /* Length of text segment */ |
85 | unsigned long entry; /* Start address for this module */ |
86 | unsigned long build_date; /* When this one was compiled */ |
87 | bool loaded; /* Has this library been loaded? */ |
88 | } lib_list[MAX_SHARED_LIBS]; |
89 | }; |
90 | |
91 | static int load_flat_binary(struct linux_binprm *); |
92 | |
93 | static struct linux_binfmt flat_format = { |
94 | .module = THIS_MODULE, |
95 | .load_binary = load_flat_binary, |
96 | }; |
97 | |
98 | |
99 | /****************************************************************************/ |
100 | /* |
101 | * create_flat_tables() parses the env- and arg-strings in new user |
102 | * memory and creates the pointer tables from them, and puts their |
103 | * addresses on the "stack", recording the new stack pointer value. |
104 | */ |
105 | |
106 | static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start) |
107 | { |
108 | char __user *p; |
109 | unsigned long __user *sp; |
110 | long i, len; |
111 | |
112 | p = (char __user *)arg_start; |
113 | sp = (unsigned long __user *)current->mm->start_stack; |
114 | |
115 | sp -= bprm->envc + 1; |
116 | sp -= bprm->argc + 1; |
117 | if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) |
118 | sp -= 2; /* argvp + envp */ |
119 | sp -= 1; /* &argc */ |
120 | |
121 | current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN; |
122 | sp = (unsigned long __user *)current->mm->start_stack; |
123 | |
124 | if (put_user(bprm->argc, sp++)) |
125 | return -EFAULT; |
126 | if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) { |
127 | unsigned long argv, envp; |
128 | argv = (unsigned long)(sp + 2); |
129 | envp = (unsigned long)(sp + 2 + bprm->argc + 1); |
130 | if (put_user(argv, sp++) || put_user(envp, sp++)) |
131 | return -EFAULT; |
132 | } |
133 | |
134 | current->mm->arg_start = (unsigned long)p; |
135 | for (i = bprm->argc; i > 0; i--) { |
136 | if (put_user((unsigned long)p, sp++)) |
137 | return -EFAULT; |
138 | len = strnlen_user(str: p, MAX_ARG_STRLEN); |
139 | if (!len || len > MAX_ARG_STRLEN) |
140 | return -EINVAL; |
141 | p += len; |
142 | } |
143 | if (put_user(0, sp++)) |
144 | return -EFAULT; |
145 | current->mm->arg_end = (unsigned long)p; |
146 | |
147 | current->mm->env_start = (unsigned long) p; |
148 | for (i = bprm->envc; i > 0; i--) { |
149 | if (put_user((unsigned long)p, sp++)) |
150 | return -EFAULT; |
151 | len = strnlen_user(str: p, MAX_ARG_STRLEN); |
152 | if (!len || len > MAX_ARG_STRLEN) |
153 | return -EINVAL; |
154 | p += len; |
155 | } |
156 | if (put_user(0, sp++)) |
157 | return -EFAULT; |
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) |
303 | { |
304 | unsigned long addr; |
305 | unsigned long start_brk; |
306 | unsigned long start_data; |
307 | unsigned long text_len; |
308 | unsigned long start_code; |
309 | |
310 | start_brk = p->lib_list[0].start_brk; |
311 | start_data = p->lib_list[0].start_data; |
312 | start_code = p->lib_list[0].start_code; |
313 | text_len = p->lib_list[0].text_len; |
314 | |
315 | if (r > start_brk - start_data + text_len) { |
316 | pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)" , |
317 | r, start_brk-start_data+text_len, text_len); |
318 | goto failed; |
319 | } |
320 | |
321 | if (r < text_len) /* In text segment */ |
322 | addr = r + start_code; |
323 | else /* In data segment */ |
324 | addr = r - text_len + start_data; |
325 | |
326 | /* Range checked already above so doing the range tests is redundant...*/ |
327 | return addr; |
328 | |
329 | failed: |
330 | pr_cont(", killing %s!\n" , current->comm); |
331 | send_sig(SIGSEGV, current, 0); |
332 | |
333 | return RELOC_FAILED; |
334 | } |
335 | |
336 | /****************************************************************************/ |
337 | |
338 | #ifdef CONFIG_BINFMT_FLAT_OLD |
339 | static void old_reloc(unsigned long rl) |
340 | { |
341 | static const char *segment[] = { "TEXT" , "DATA" , "BSS" , "*UNKNOWN*" }; |
342 | flat_v2_reloc_t r; |
343 | unsigned long __user *ptr; |
344 | unsigned long val; |
345 | |
346 | r.value = rl; |
347 | #if defined(CONFIG_COLDFIRE) |
348 | ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset); |
349 | #else |
350 | ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset); |
351 | #endif |
352 | get_user(val, ptr); |
353 | |
354 | pr_debug("Relocation of variable at DATASEG+%x " |
355 | "(address %p, currently %lx) into segment %s\n" , |
356 | r.reloc.offset, ptr, val, segment[r.reloc.type]); |
357 | |
358 | switch (r.reloc.type) { |
359 | case OLD_FLAT_RELOC_TYPE_TEXT: |
360 | val += current->mm->start_code; |
361 | break; |
362 | case OLD_FLAT_RELOC_TYPE_DATA: |
363 | val += current->mm->start_data; |
364 | break; |
365 | case OLD_FLAT_RELOC_TYPE_BSS: |
366 | val += current->mm->end_data; |
367 | break; |
368 | default: |
369 | pr_err("Unknown relocation type=%x\n" , r.reloc.type); |
370 | break; |
371 | } |
372 | put_user(val, ptr); |
373 | |
374 | pr_debug("Relocation became %lx\n" , val); |
375 | } |
376 | #endif /* CONFIG_BINFMT_FLAT_OLD */ |
377 | |
378 | /****************************************************************************/ |
379 | |
380 | static inline u32 __user *(u32 __user *rp) |
381 | { |
382 | if (IS_ENABLED(CONFIG_RISCV)) { |
383 | /* |
384 | * RISC-V has a 16 byte GOT PLT header for elf64-riscv |
385 | * and 8 byte GOT PLT header for elf32-riscv. |
386 | * Skip the whole GOT PLT header, since it is reserved |
387 | * for the dynamic linker (ld.so). |
388 | */ |
389 | u32 rp_val0, rp_val1; |
390 | |
391 | if (get_user(rp_val0, rp)) |
392 | return rp; |
393 | if (get_user(rp_val1, rp + 1)) |
394 | return rp; |
395 | |
396 | if (rp_val0 == 0xffffffff && rp_val1 == 0xffffffff) |
397 | rp += 4; |
398 | else if (rp_val0 == 0xffffffff) |
399 | rp += 2; |
400 | } |
401 | return rp; |
402 | } |
403 | |
404 | static int load_flat_file(struct linux_binprm *bprm, |
405 | struct lib_info *libinfo, unsigned long *) |
406 | { |
407 | struct flat_hdr *hdr; |
408 | unsigned long textpos, datapos, realdatastart; |
409 | u32 text_len, data_len, bss_len, stack_len, full_data, flags; |
410 | unsigned long len, memp, memp_size, , rlim; |
411 | __be32 __user *reloc; |
412 | u32 __user *rp; |
413 | int i, rev, relocs; |
414 | loff_t fpos; |
415 | unsigned long start_code, end_code; |
416 | ssize_t result; |
417 | int ret; |
418 | |
419 | hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */ |
420 | |
421 | text_len = ntohl(hdr->data_start); |
422 | data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start); |
423 | bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end); |
424 | stack_len = ntohl(hdr->stack_size); |
425 | if (extra_stack) { |
426 | stack_len += *extra_stack; |
427 | *extra_stack = stack_len; |
428 | } |
429 | relocs = ntohl(hdr->reloc_count); |
430 | flags = ntohl(hdr->flags); |
431 | rev = ntohl(hdr->rev); |
432 | full_data = data_len + relocs * sizeof(unsigned long); |
433 | |
434 | if (strncmp(hdr->magic, "bFLT" , 4)) { |
435 | /* |
436 | * Previously, here was a printk to tell people |
437 | * "BINFMT_FLAT: bad header magic". |
438 | * But for the kernel which also use ELF FD-PIC format, this |
439 | * error message is confusing. |
440 | * because a lot of people do not manage to produce good |
441 | */ |
442 | ret = -ENOEXEC; |
443 | goto err; |
444 | } |
445 | |
446 | if (flags & FLAT_FLAG_KTRACE) |
447 | pr_info("Loading file: %s\n" , bprm->filename); |
448 | |
449 | #ifdef CONFIG_BINFMT_FLAT_OLD |
450 | if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) { |
451 | pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n" , |
452 | rev, FLAT_VERSION, OLD_FLAT_VERSION); |
453 | ret = -ENOEXEC; |
454 | goto err; |
455 | } |
456 | |
457 | /* |
458 | * fix up the flags for the older format, there were all kinds |
459 | * of endian hacks, this only works for the simple cases |
460 | */ |
461 | if (rev == OLD_FLAT_VERSION && |
462 | (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM))) |
463 | flags = FLAT_FLAG_RAM; |
464 | |
465 | #else /* CONFIG_BINFMT_FLAT_OLD */ |
466 | if (rev != FLAT_VERSION) { |
467 | pr_err("bad flat file version 0x%x (supported 0x%lx)\n" , |
468 | rev, FLAT_VERSION); |
469 | ret = -ENOEXEC; |
470 | goto err; |
471 | } |
472 | #endif /* !CONFIG_BINFMT_FLAT_OLD */ |
473 | |
474 | /* |
475 | * Make sure the header params are sane. |
476 | * 28 bits (256 MB) is way more than reasonable in this case. |
477 | * If some top bits are set we have probable binary corruption. |
478 | */ |
479 | if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) { |
480 | pr_err("bad header\n" ); |
481 | ret = -ENOEXEC; |
482 | goto err; |
483 | } |
484 | |
485 | #ifndef CONFIG_BINFMT_ZFLAT |
486 | if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) { |
487 | pr_err("Support for ZFLAT executables is not enabled.\n" ); |
488 | ret = -ENOEXEC; |
489 | goto err; |
490 | } |
491 | #endif |
492 | |
493 | /* |
494 | * Check initial limits. This avoids letting people circumvent |
495 | * size limits imposed on them by creating programs with large |
496 | * arrays in the data or bss. |
497 | */ |
498 | rlim = rlimit(RLIMIT_DATA); |
499 | if (rlim >= RLIM_INFINITY) |
500 | rlim = ~0; |
501 | if (data_len + bss_len > rlim) { |
502 | ret = -ENOMEM; |
503 | goto err; |
504 | } |
505 | |
506 | /* Flush all traces of the currently running executable */ |
507 | ret = begin_new_exec(bprm); |
508 | if (ret) |
509 | goto err; |
510 | |
511 | /* OK, This is the point of no return */ |
512 | set_personality(PER_LINUX_32BIT); |
513 | setup_new_exec(bprm); |
514 | |
515 | /* |
516 | * calculate the extra space we need to map in |
517 | */ |
518 | extra = max_t(unsigned long, bss_len + stack_len, |
519 | relocs * sizeof(unsigned long)); |
520 | |
521 | /* |
522 | * there are a couple of cases here, the separate code/data |
523 | * case, and then the fully copied to RAM case which lumps |
524 | * it all together. |
525 | */ |
526 | if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) { |
527 | /* |
528 | * this should give us a ROM ptr, but if it doesn't we don't |
529 | * really care |
530 | */ |
531 | pr_debug("ROM mapping of file (we hope)\n" ); |
532 | |
533 | textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, |
534 | MAP_PRIVATE, 0); |
535 | if (!textpos || IS_ERR_VALUE(textpos)) { |
536 | ret = textpos; |
537 | if (!textpos) |
538 | ret = -ENOMEM; |
539 | pr_err("Unable to mmap process text, errno %d\n" , ret); |
540 | goto err; |
541 | } |
542 | |
543 | len = data_len + extra + |
544 | DATA_START_OFFSET_WORDS * sizeof(unsigned long); |
545 | len = PAGE_ALIGN(len); |
546 | realdatastart = vm_mmap(NULL, 0, len, |
547 | PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0); |
548 | |
549 | if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) { |
550 | ret = realdatastart; |
551 | if (!realdatastart) |
552 | ret = -ENOMEM; |
553 | pr_err("Unable to allocate RAM for process data, " |
554 | "errno %d\n" , ret); |
555 | vm_munmap(textpos, text_len); |
556 | goto err; |
557 | } |
558 | datapos = ALIGN(realdatastart + |
559 | DATA_START_OFFSET_WORDS * sizeof(unsigned long), |
560 | FLAT_DATA_ALIGN); |
561 | |
562 | pr_debug("Allocated data+bss+stack (%u bytes): %lx\n" , |
563 | data_len + bss_len + stack_len, datapos); |
564 | |
565 | fpos = ntohl(hdr->data_start); |
566 | #ifdef CONFIG_BINFMT_ZFLAT |
567 | if (flags & FLAT_FLAG_GZDATA) { |
568 | result = decompress_exec(bprm, fpos, (char *)datapos, |
569 | full_data, 0); |
570 | } else |
571 | #endif |
572 | { |
573 | result = read_code(bprm->file, datapos, fpos, |
574 | full_data); |
575 | } |
576 | if (IS_ERR_VALUE(result)) { |
577 | ret = result; |
578 | pr_err("Unable to read data+bss, errno %d\n" , ret); |
579 | vm_munmap(textpos, text_len); |
580 | vm_munmap(realdatastart, len); |
581 | goto err; |
582 | } |
583 | |
584 | reloc = (__be32 __user *) |
585 | (datapos + (ntohl(hdr->reloc_start) - text_len)); |
586 | memp = realdatastart; |
587 | memp_size = len; |
588 | } else { |
589 | |
590 | len = text_len + data_len + extra + |
591 | DATA_START_OFFSET_WORDS * sizeof(u32); |
592 | len = PAGE_ALIGN(len); |
593 | textpos = vm_mmap(NULL, 0, len, |
594 | PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0); |
595 | |
596 | if (!textpos || IS_ERR_VALUE(textpos)) { |
597 | ret = textpos; |
598 | if (!textpos) |
599 | ret = -ENOMEM; |
600 | pr_err("Unable to allocate RAM for process text/data, " |
601 | "errno %d\n" , ret); |
602 | goto err; |
603 | } |
604 | |
605 | realdatastart = textpos + ntohl(hdr->data_start); |
606 | datapos = ALIGN(realdatastart + |
607 | DATA_START_OFFSET_WORDS * sizeof(u32), |
608 | FLAT_DATA_ALIGN); |
609 | |
610 | reloc = (__be32 __user *) |
611 | (datapos + (ntohl(hdr->reloc_start) - text_len)); |
612 | memp = textpos; |
613 | memp_size = len; |
614 | #ifdef CONFIG_BINFMT_ZFLAT |
615 | /* |
616 | * load it all in and treat it like a RAM load from now on |
617 | */ |
618 | if (flags & FLAT_FLAG_GZIP) { |
619 | #ifndef CONFIG_MMU |
620 | result = decompress_exec(bprm, sizeof(struct flat_hdr), |
621 | (((char *)textpos) + sizeof(struct flat_hdr)), |
622 | (text_len + full_data |
623 | - sizeof(struct flat_hdr)), |
624 | 0); |
625 | memmove((void *) datapos, (void *) realdatastart, |
626 | full_data); |
627 | #else |
628 | /* |
629 | * This is used on MMU systems mainly for testing. |
630 | * Let's use a kernel buffer to simplify things. |
631 | */ |
632 | long unz_text_len = text_len - sizeof(struct flat_hdr); |
633 | long unz_len = unz_text_len + full_data; |
634 | char *unz_data = vmalloc(unz_len); |
635 | if (!unz_data) { |
636 | result = -ENOMEM; |
637 | } else { |
638 | result = decompress_exec(bprm, sizeof(struct flat_hdr), |
639 | unz_data, unz_len, 0); |
640 | if (result == 0 && |
641 | (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr), |
642 | unz_data, unz_text_len) || |
643 | copy_to_user((void __user *)datapos, |
644 | unz_data + unz_text_len, full_data))) |
645 | result = -EFAULT; |
646 | vfree(unz_data); |
647 | } |
648 | #endif |
649 | } else if (flags & FLAT_FLAG_GZDATA) { |
650 | result = read_code(bprm->file, textpos, 0, text_len); |
651 | if (!IS_ERR_VALUE(result)) { |
652 | #ifndef CONFIG_MMU |
653 | result = decompress_exec(bprm, text_len, (char *) datapos, |
654 | full_data, 0); |
655 | #else |
656 | char *unz_data = vmalloc(full_data); |
657 | if (!unz_data) { |
658 | result = -ENOMEM; |
659 | } else { |
660 | result = decompress_exec(bprm, text_len, |
661 | unz_data, full_data, 0); |
662 | if (result == 0 && |
663 | copy_to_user((void __user *)datapos, |
664 | unz_data, full_data)) |
665 | result = -EFAULT; |
666 | vfree(unz_data); |
667 | } |
668 | #endif |
669 | } |
670 | } else |
671 | #endif /* CONFIG_BINFMT_ZFLAT */ |
672 | { |
673 | result = read_code(bprm->file, textpos, 0, text_len); |
674 | if (!IS_ERR_VALUE(result)) |
675 | result = read_code(bprm->file, datapos, |
676 | ntohl(hdr->data_start), |
677 | full_data); |
678 | } |
679 | if (IS_ERR_VALUE(result)) { |
680 | ret = result; |
681 | pr_err("Unable to read code+data+bss, errno %d\n" , ret); |
682 | vm_munmap(textpos, text_len + data_len + extra + |
683 | DATA_START_OFFSET_WORDS * sizeof(u32)); |
684 | goto err; |
685 | } |
686 | } |
687 | |
688 | start_code = textpos + sizeof(struct flat_hdr); |
689 | end_code = textpos + text_len; |
690 | text_len -= sizeof(struct flat_hdr); /* the real code len */ |
691 | |
692 | /* The main program needs a little extra setup in the task structure */ |
693 | current->mm->start_code = start_code; |
694 | current->mm->end_code = end_code; |
695 | current->mm->start_data = datapos; |
696 | current->mm->end_data = datapos + data_len; |
697 | /* |
698 | * set up the brk stuff, uses any slack left in data/bss/stack |
699 | * allocation. We put the brk after the bss (between the bss |
700 | * and stack) like other platforms. |
701 | * Userspace code relies on the stack pointer starting out at |
702 | * an address right at the end of a page. |
703 | */ |
704 | current->mm->start_brk = datapos + data_len + bss_len; |
705 | current->mm->brk = (current->mm->start_brk + 3) & ~3; |
706 | #ifndef CONFIG_MMU |
707 | current->mm->context.end_brk = memp + memp_size - stack_len; |
708 | #endif |
709 | |
710 | if (flags & FLAT_FLAG_KTRACE) { |
711 | pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n" , |
712 | textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start)); |
713 | pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n" , |
714 | "Load" , bprm->filename, |
715 | start_code, end_code, datapos, datapos + data_len, |
716 | datapos + data_len, (datapos + data_len + bss_len + 3) & ~3); |
717 | } |
718 | |
719 | /* Store the current module values into the global library structure */ |
720 | libinfo->lib_list[0].start_code = start_code; |
721 | libinfo->lib_list[0].start_data = datapos; |
722 | libinfo->lib_list[0].start_brk = datapos + data_len + bss_len; |
723 | libinfo->lib_list[0].text_len = text_len; |
724 | libinfo->lib_list[0].loaded = 1; |
725 | libinfo->lib_list[0].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos; |
726 | libinfo->lib_list[0].build_date = ntohl(hdr->build_date); |
727 | |
728 | /* |
729 | * We just load the allocations into some temporary memory to |
730 | * help simplify all this mumbo jumbo |
731 | * |
732 | * We've got two different sections of relocation entries. |
733 | * The first is the GOT which resides at the beginning of the data segment |
734 | * and is terminated with a -1. This one can be relocated in place. |
735 | * The second is the extra relocation entries tacked after the image's |
736 | * data segment. These require a little more processing as the entry is |
737 | * really an offset into the image which contains an offset into the |
738 | * image. |
739 | */ |
740 | if (flags & FLAT_FLAG_GOTPIC) { |
741 | rp = skip_got_header(rp: (u32 __user *) datapos); |
742 | for (; ; rp++) { |
743 | u32 addr, rp_val; |
744 | if (get_user(rp_val, rp)) |
745 | return -EFAULT; |
746 | if (rp_val == 0xffffffff) |
747 | break; |
748 | if (rp_val) { |
749 | addr = calc_reloc(r: rp_val, p: libinfo); |
750 | if (addr == RELOC_FAILED) { |
751 | ret = -ENOEXEC; |
752 | goto err; |
753 | } |
754 | if (put_user(addr, rp)) |
755 | return -EFAULT; |
756 | } |
757 | } |
758 | } |
759 | |
760 | /* |
761 | * Now run through the relocation entries. |
762 | * We've got to be careful here as C++ produces relocatable zero |
763 | * entries in the constructor and destructor tables which are then |
764 | * tested for being not zero (which will always occur unless we're |
765 | * based from address zero). This causes an endless loop as __start |
766 | * is at zero. The solution used is to not relocate zero addresses. |
767 | * This has the negative side effect of not allowing a global data |
768 | * reference to be statically initialised to _stext (I've moved |
769 | * __start to address 4 so that is okay). |
770 | */ |
771 | if (rev > OLD_FLAT_VERSION) { |
772 | for (i = 0; i < relocs; i++) { |
773 | u32 addr, relval; |
774 | __be32 tmp; |
775 | |
776 | /* |
777 | * Get the address of the pointer to be |
778 | * relocated (of course, the address has to be |
779 | * relocated first). |
780 | */ |
781 | if (get_user(tmp, reloc + i)) |
782 | return -EFAULT; |
783 | relval = ntohl(tmp); |
784 | addr = flat_get_relocate_addr(relval); |
785 | rp = (u32 __user *)calc_reloc(r: addr, p: libinfo); |
786 | if (rp == (u32 __user *)RELOC_FAILED) { |
787 | ret = -ENOEXEC; |
788 | goto err; |
789 | } |
790 | |
791 | /* Get the pointer's value. */ |
792 | ret = flat_get_addr_from_rp(rp, relval, flags, &addr); |
793 | if (unlikely(ret)) |
794 | goto err; |
795 | |
796 | if (addr != 0) { |
797 | /* |
798 | * Do the relocation. PIC relocs in the data section are |
799 | * already in target order |
800 | */ |
801 | if ((flags & FLAT_FLAG_GOTPIC) == 0) { |
802 | /* |
803 | * Meh, the same value can have a different |
804 | * byte order based on a flag.. |
805 | */ |
806 | addr = ntohl((__force __be32)addr); |
807 | } |
808 | addr = calc_reloc(r: addr, p: libinfo); |
809 | if (addr == RELOC_FAILED) { |
810 | ret = -ENOEXEC; |
811 | goto err; |
812 | } |
813 | |
814 | /* Write back the relocated pointer. */ |
815 | ret = flat_put_addr_at_rp(rp, addr, relval); |
816 | if (unlikely(ret)) |
817 | goto err; |
818 | } |
819 | } |
820 | #ifdef CONFIG_BINFMT_FLAT_OLD |
821 | } else { |
822 | for (i = 0; i < relocs; i++) { |
823 | __be32 relval; |
824 | if (get_user(relval, reloc + i)) |
825 | return -EFAULT; |
826 | old_reloc(ntohl(relval)); |
827 | } |
828 | #endif /* CONFIG_BINFMT_FLAT_OLD */ |
829 | } |
830 | |
831 | flush_icache_user_range(start: start_code, end: end_code); |
832 | |
833 | /* zero the BSS, BRK and stack areas */ |
834 | if (clear_user(to: (void __user *)(datapos + data_len), n: bss_len + |
835 | (memp + memp_size - stack_len - /* end brk */ |
836 | libinfo->lib_list[0].start_brk) + /* start brk */ |
837 | stack_len)) |
838 | return -EFAULT; |
839 | |
840 | return 0; |
841 | err: |
842 | return ret; |
843 | } |
844 | |
845 | |
846 | /****************************************************************************/ |
847 | |
848 | /* |
849 | * These are the functions used to load flat style executables and shared |
850 | * libraries. There is no binary dependent code anywhere else. |
851 | */ |
852 | |
853 | static int load_flat_binary(struct linux_binprm *bprm) |
854 | { |
855 | struct lib_info libinfo; |
856 | struct pt_regs *regs = current_pt_regs(); |
857 | unsigned long stack_len = 0; |
858 | unsigned long start_addr; |
859 | int res; |
860 | int i, j; |
861 | |
862 | memset(&libinfo, 0, sizeof(libinfo)); |
863 | |
864 | /* |
865 | * We have to add the size of our arguments to our stack size |
866 | * otherwise it's too easy for users to create stack overflows |
867 | * by passing in a huge argument list. And yes, we have to be |
868 | * pedantic and include space for the argv/envp array as it may have |
869 | * a lot of entries. |
870 | */ |
871 | #ifndef CONFIG_MMU |
872 | stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */ |
873 | #endif |
874 | stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */ |
875 | stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */ |
876 | stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN); |
877 | |
878 | res = load_flat_file(bprm, libinfo: &libinfo, extra_stack: &stack_len); |
879 | if (res < 0) |
880 | return res; |
881 | |
882 | /* Update data segment pointers for all libraries */ |
883 | for (i = 0; i < MAX_SHARED_LIBS; i++) { |
884 | if (!libinfo.lib_list[i].loaded) |
885 | continue; |
886 | for (j = 0; j < MAX_SHARED_LIBS; j++) { |
887 | unsigned long val = libinfo.lib_list[j].loaded ? |
888 | libinfo.lib_list[j].start_data : UNLOADED_LIB; |
889 | unsigned long __user *p = (unsigned long __user *) |
890 | libinfo.lib_list[i].start_data; |
891 | p -= j + 1; |
892 | if (put_user(val, p)) |
893 | return -EFAULT; |
894 | } |
895 | } |
896 | |
897 | set_binfmt(&flat_format); |
898 | |
899 | #ifdef CONFIG_MMU |
900 | res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT); |
901 | if (!res) |
902 | res = create_flat_tables(bprm, arg_start: bprm->p); |
903 | #else |
904 | /* Stash our initial stack pointer into the mm structure */ |
905 | current->mm->start_stack = |
906 | ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4; |
907 | pr_debug("sp=%lx\n" , current->mm->start_stack); |
908 | |
909 | /* copy the arg pages onto the stack */ |
910 | res = transfer_args_to_stack(bprm, ¤t->mm->start_stack); |
911 | if (!res) |
912 | res = create_flat_tables(bprm, current->mm->start_stack); |
913 | #endif |
914 | if (res) |
915 | return res; |
916 | |
917 | /* Fake some return addresses to ensure the call chain will |
918 | * initialise library in order for us. We are required to call |
919 | * lib 1 first, then 2, ... and finally the main program (id 0). |
920 | */ |
921 | start_addr = libinfo.lib_list[0].entry; |
922 | |
923 | #ifdef FLAT_PLAT_INIT |
924 | FLAT_PLAT_INIT(regs); |
925 | #endif |
926 | |
927 | finalize_exec(bprm); |
928 | pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n" , |
929 | regs, start_addr, current->mm->start_stack); |
930 | start_thread(regs, new_ip: start_addr, current->mm->start_stack); |
931 | |
932 | return 0; |
933 | } |
934 | |
935 | /****************************************************************************/ |
936 | |
937 | static int __init init_flat_binfmt(void) |
938 | { |
939 | register_binfmt(fmt: &flat_format); |
940 | return 0; |
941 | } |
942 | core_initcall(init_flat_binfmt); |
943 | |
944 | /****************************************************************************/ |
945 | |