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crypto: atmel-sha - remove unnecessary static in atmel_sha_remove()
[linux-stable.git] / fs / binfmt_flat.c
blob69ec23daa25e003ff94ef306c93a0a77c51b00a3
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 (%ld 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, &current->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 /****************************************************************************/
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