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