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