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Merge tag 'trace-v4.14-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rosted...
[GitHub/LineageOS/android_kernel_motorola_exynos9610.git] / fs / binfmt_flat.c
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(struct linux_binprm *bprm, loff_t fpos, char *dst,
180 long len, int fd)
181 {
182 unsigned char *buf;
183 z_stream strm;
184 int ret, retval;
185
186 pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
187
188 memset(&strm, 0, sizeof(strm));
189 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
190 if (!strm.workspace)
191 return -ENOMEM;
192
193 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
194 if (!buf) {
195 retval = -ENOMEM;
196 goto out_free;
197 }
198
199 /* Read in first chunk of data and parse gzip header. */
200 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
201
202 strm.next_in = buf;
203 strm.avail_in = ret;
204 strm.total_in = 0;
205
206 retval = -ENOEXEC;
207
208 /* Check minimum size -- gzip header */
209 if (ret < 10) {
210 pr_debug("file too small?\n");
211 goto out_free_buf;
212 }
213
214 /* Check gzip magic number */
215 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
216 pr_debug("unknown compression magic?\n");
217 goto out_free_buf;
218 }
219
220 /* Check gzip method */
221 if (buf[2] != 8) {
222 pr_debug("unknown compression method?\n");
223 goto out_free_buf;
224 }
225 /* Check gzip flags */
226 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
227 (buf[3] & RESERVED)) {
228 pr_debug("unknown flags?\n");
229 goto out_free_buf;
230 }
231
232 ret = 10;
233 if (buf[3] & EXTRA_FIELD) {
234 ret += 2 + buf[10] + (buf[11] << 8);
235 if (unlikely(ret >= LBUFSIZE)) {
236 pr_debug("buffer overflow (EXTRA)?\n");
237 goto out_free_buf;
238 }
239 }
240 if (buf[3] & ORIG_NAME) {
241 while (ret < LBUFSIZE && buf[ret++] != 0)
242 ;
243 if (unlikely(ret == LBUFSIZE)) {
244 pr_debug("buffer overflow (ORIG_NAME)?\n");
245 goto out_free_buf;
246 }
247 }
248 if (buf[3] & COMMENT) {
249 while (ret < LBUFSIZE && buf[ret++] != 0)
250 ;
251 if (unlikely(ret == LBUFSIZE)) {
252 pr_debug("buffer overflow (COMMENT)?\n");
253 goto out_free_buf;
254 }
255 }
256
257 strm.next_in += ret;
258 strm.avail_in -= ret;
259
260 strm.next_out = dst;
261 strm.avail_out = len;
262 strm.total_out = 0;
263
264 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
265 pr_debug("zlib init failed?\n");
266 goto out_free_buf;
267 }
268
269 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
270 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
271 if (ret <= 0)
272 break;
273 len -= ret;
274
275 strm.next_in = buf;
276 strm.avail_in = ret;
277 strm.total_in = 0;
278 }
279
280 if (ret < 0) {
281 pr_debug("decompression failed (%d), %s\n",
282 ret, strm.msg);
283 goto out_zlib;
284 }
285
286 retval = 0;
287 out_zlib:
288 zlib_inflateEnd(&strm);
289 out_free_buf:
290 kfree(buf);
291 out_free:
292 kfree(strm.workspace);
293 return retval;
294 }
295
296 #endif /* CONFIG_BINFMT_ZFLAT */
297
298 /****************************************************************************/
299
300 static unsigned long
301 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
302 {
303 unsigned long addr;
304 int id;
305 unsigned long start_brk;
306 unsigned long start_data;
307 unsigned long text_len;
308 unsigned long start_code;
309
310 #ifdef CONFIG_BINFMT_SHARED_FLAT
311 if (r == 0)
312 id = curid; /* Relocs of 0 are always self referring */
313 else {
314 id = (r >> 24) & 0xff; /* Find ID for this reloc */
315 r &= 0x00ffffff; /* Trim ID off here */
316 }
317 if (id >= MAX_SHARED_LIBS) {
318 pr_err("reference 0x%lx to shared library %d", r, id);
319 goto failed;
320 }
321 if (curid != id) {
322 if (internalp) {
323 pr_err("reloc address 0x%lx not in same module "
324 "(%d != %d)", r, curid, id);
325 goto failed;
326 } else if (!p->lib_list[id].loaded &&
327 load_flat_shared_library(id, p) < 0) {
328 pr_err("failed to load library %d", id);
329 goto failed;
330 }
331 /* Check versioning information (i.e. time stamps) */
332 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
333 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
334 pr_err("library %d is younger than %d", id, curid);
335 goto failed;
336 }
337 }
338 #else
339 id = 0;
340 #endif
341
342 start_brk = p->lib_list[id].start_brk;
343 start_data = p->lib_list[id].start_data;
344 start_code = p->lib_list[id].start_code;
345 text_len = p->lib_list[id].text_len;
346
347 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
348 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
349 r, start_brk-start_data+text_len, text_len);
350 goto failed;
351 }
352
353 if (r < text_len) /* In text segment */
354 addr = r + start_code;
355 else /* In data segment */
356 addr = r - text_len + start_data;
357
358 /* Range checked already above so doing the range tests is redundant...*/
359 return addr;
360
361 failed:
362 pr_cont(", killing %s!\n", current->comm);
363 send_sig(SIGSEGV, current, 0);
364
365 return RELOC_FAILED;
366 }
367
368 /****************************************************************************/
369
370 static void old_reloc(unsigned long rl)
371 {
372 static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
373 flat_v2_reloc_t r;
374 unsigned long __user *ptr;
375 unsigned long val;
376
377 r.value = rl;
378 #if defined(CONFIG_COLDFIRE)
379 ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
380 #else
381 ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
382 #endif
383 get_user(val, ptr);
384
385 pr_debug("Relocation of variable at DATASEG+%x "
386 "(address %p, currently %lx) into segment %s\n",
387 r.reloc.offset, ptr, val, segment[r.reloc.type]);
388
389 switch (r.reloc.type) {
390 case OLD_FLAT_RELOC_TYPE_TEXT:
391 val += current->mm->start_code;
392 break;
393 case OLD_FLAT_RELOC_TYPE_DATA:
394 val += current->mm->start_data;
395 break;
396 case OLD_FLAT_RELOC_TYPE_BSS:
397 val += current->mm->end_data;
398 break;
399 default:
400 pr_err("Unknown relocation type=%x\n", r.reloc.type);
401 break;
402 }
403 put_user(val, ptr);
404
405 pr_debug("Relocation became %lx\n", val);
406 }
407
408 /****************************************************************************/
409
410 static int load_flat_file(struct linux_binprm *bprm,
411 struct lib_info *libinfo, int id, unsigned long *extra_stack)
412 {
413 struct flat_hdr *hdr;
414 unsigned long textpos, datapos, realdatastart;
415 u32 text_len, data_len, bss_len, stack_len, full_data, flags;
416 unsigned long len, memp, memp_size, extra, rlim;
417 u32 __user *reloc, *rp;
418 struct inode *inode;
419 int i, rev, relocs;
420 loff_t fpos;
421 unsigned long start_code, end_code;
422 ssize_t result;
423 int ret;
424
425 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
426 inode = file_inode(bprm->file);
427
428 text_len = ntohl(hdr->data_start);
429 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
430 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
431 stack_len = ntohl(hdr->stack_size);
432 if (extra_stack) {
433 stack_len += *extra_stack;
434 *extra_stack = stack_len;
435 }
436 relocs = ntohl(hdr->reloc_count);
437 flags = ntohl(hdr->flags);
438 rev = ntohl(hdr->rev);
439 full_data = data_len + relocs * sizeof(unsigned long);
440
441 if (strncmp(hdr->magic, "bFLT", 4)) {
442 /*
443 * Previously, here was a printk to tell people
444 * "BINFMT_FLAT: bad header magic".
445 * But for the kernel which also use ELF FD-PIC format, this
446 * error message is confusing.
447 * because a lot of people do not manage to produce good
448 */
449 ret = -ENOEXEC;
450 goto err;
451 }
452
453 if (flags & FLAT_FLAG_KTRACE)
454 pr_info("Loading file: %s\n", bprm->filename);
455
456 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
457 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
458 rev, FLAT_VERSION, OLD_FLAT_VERSION);
459 ret = -ENOEXEC;
460 goto err;
461 }
462
463 /* Don't allow old format executables to use shared libraries */
464 if (rev == OLD_FLAT_VERSION && id != 0) {
465 pr_err("shared libraries are not available before rev 0x%lx\n",
466 FLAT_VERSION);
467 ret = -ENOEXEC;
468 goto err;
469 }
470
471 /*
472 * Make sure the header params are sane.
473 * 28 bits (256 MB) is way more than reasonable in this case.
474 * If some top bits are set we have probable binary corruption.
475 */
476 if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
477 pr_err("bad header\n");
478 ret = -ENOEXEC;
479 goto err;
480 }
481
482 /*
483 * fix up the flags for the older format, there were all kinds
484 * of endian hacks, this only works for the simple cases
485 */
486 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
487 flags = FLAT_FLAG_RAM;
488
489 #ifndef CONFIG_BINFMT_ZFLAT
490 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
491 pr_err("Support for ZFLAT executables is not enabled.\n");
492 ret = -ENOEXEC;
493 goto err;
494 }
495 #endif
496
497 /*
498 * Check initial limits. This avoids letting people circumvent
499 * size limits imposed on them by creating programs with large
500 * arrays in the data or bss.
501 */
502 rlim = rlimit(RLIMIT_DATA);
503 if (rlim >= RLIM_INFINITY)
504 rlim = ~0;
505 if (data_len + bss_len > rlim) {
506 ret = -ENOMEM;
507 goto err;
508 }
509
510 /* Flush all traces of the currently running executable */
511 if (id == 0) {
512 ret = flush_old_exec(bprm);
513 if (ret)
514 goto err;
515
516 /* OK, This is the point of no return */
517 set_personality(PER_LINUX_32BIT);
518 setup_new_exec(bprm);
519 }
520
521 /*
522 * calculate the extra space we need to map in
523 */
524 extra = max_t(unsigned long, bss_len + stack_len,
525 relocs * sizeof(unsigned long));
526
527 /*
528 * there are a couple of cases here, the separate code/data
529 * case, and then the fully copied to RAM case which lumps
530 * it all together.
531 */
532 if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
533 /*
534 * this should give us a ROM ptr, but if it doesn't we don't
535 * really care
536 */
537 pr_debug("ROM mapping of file (we hope)\n");
538
539 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
540 MAP_PRIVATE|MAP_EXECUTABLE, 0);
541 if (!textpos || IS_ERR_VALUE(textpos)) {
542 ret = textpos;
543 if (!textpos)
544 ret = -ENOMEM;
545 pr_err("Unable to mmap process text, errno %d\n", ret);
546 goto err;
547 }
548
549 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
550 len = PAGE_ALIGN(len);
551 realdatastart = vm_mmap(NULL, 0, len,
552 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
553
554 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
555 ret = realdatastart;
556 if (!realdatastart)
557 ret = -ENOMEM;
558 pr_err("Unable to allocate RAM for process data, "
559 "errno %d\n", ret);
560 vm_munmap(textpos, text_len);
561 goto err;
562 }
563 datapos = ALIGN(realdatastart +
564 MAX_SHARED_LIBS * sizeof(unsigned long),
565 FLAT_DATA_ALIGN);
566
567 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
568 data_len + bss_len + stack_len, datapos);
569
570 fpos = ntohl(hdr->data_start);
571 #ifdef CONFIG_BINFMT_ZFLAT
572 if (flags & FLAT_FLAG_GZDATA) {
573 result = decompress_exec(bprm, fpos, (char *)datapos,
574 full_data, 0);
575 } else
576 #endif
577 {
578 result = read_code(bprm->file, datapos, fpos,
579 full_data);
580 }
581 if (IS_ERR_VALUE(result)) {
582 ret = result;
583 pr_err("Unable to read data+bss, errno %d\n", ret);
584 vm_munmap(textpos, text_len);
585 vm_munmap(realdatastart, len);
586 goto err;
587 }
588
589 reloc = (u32 __user *)
590 (datapos + (ntohl(hdr->reloc_start) - text_len));
591 memp = realdatastart;
592 memp_size = len;
593 } else {
594
595 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);
596 len = PAGE_ALIGN(len);
597 textpos = vm_mmap(NULL, 0, len,
598 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
599
600 if (!textpos || IS_ERR_VALUE(textpos)) {
601 ret = textpos;
602 if (!textpos)
603 ret = -ENOMEM;
604 pr_err("Unable to allocate RAM for process text/data, "
605 "errno %d\n", ret);
606 goto err;
607 }
608
609 realdatastart = textpos + ntohl(hdr->data_start);
610 datapos = ALIGN(realdatastart +
611 MAX_SHARED_LIBS * sizeof(u32),
612 FLAT_DATA_ALIGN);
613
614 reloc = (u32 __user *)
615 (datapos + (ntohl(hdr->reloc_start) - text_len));
616 memp = textpos;
617 memp_size = len;
618 #ifdef CONFIG_BINFMT_ZFLAT
619 /*
620 * load it all in and treat it like a RAM load from now on
621 */
622 if (flags & FLAT_FLAG_GZIP) {
623 #ifndef CONFIG_MMU
624 result = decompress_exec(bprm, sizeof(struct flat_hdr),
625 (((char *)textpos) + sizeof(struct flat_hdr)),
626 (text_len + full_data
627 - sizeof(struct flat_hdr)),
628 0);
629 memmove((void *) datapos, (void *) realdatastart,
630 full_data);
631 #else
632 /*
633 * This is used on MMU systems mainly for testing.
634 * Let's use a kernel buffer to simplify things.
635 */
636 long unz_text_len = text_len - sizeof(struct flat_hdr);
637 long unz_len = unz_text_len + full_data;
638 char *unz_data = vmalloc(unz_len);
639 if (!unz_data) {
640 result = -ENOMEM;
641 } else {
642 result = decompress_exec(bprm, sizeof(struct flat_hdr),
643 unz_data, unz_len, 0);
644 if (result == 0 &&
645 (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
646 unz_data, unz_text_len) ||
647 copy_to_user((void __user *)datapos,
648 unz_data + unz_text_len, full_data)))
649 result = -EFAULT;
650 vfree(unz_data);
651 }
652 #endif
653 } else if (flags & FLAT_FLAG_GZDATA) {
654 result = read_code(bprm->file, textpos, 0, text_len);
655 if (!IS_ERR_VALUE(result)) {
656 #ifndef CONFIG_MMU
657 result = decompress_exec(bprm, text_len, (char *) datapos,
658 full_data, 0);
659 #else
660 char *unz_data = vmalloc(full_data);
661 if (!unz_data) {
662 result = -ENOMEM;
663 } else {
664 result = decompress_exec(bprm, text_len,
665 unz_data, full_data, 0);
666 if (result == 0 &&
667 copy_to_user((void __user *)datapos,
668 unz_data, full_data))
669 result = -EFAULT;
670 vfree(unz_data);
671 }
672 #endif
673 }
674 } else
675 #endif /* CONFIG_BINFMT_ZFLAT */
676 {
677 result = read_code(bprm->file, textpos, 0, text_len);
678 if (!IS_ERR_VALUE(result))
679 result = read_code(bprm->file, datapos,
680 ntohl(hdr->data_start),
681 full_data);
682 }
683 if (IS_ERR_VALUE(result)) {
684 ret = result;
685 pr_err("Unable to read code+data+bss, errno %d\n", ret);
686 vm_munmap(textpos, text_len + data_len + extra +
687 MAX_SHARED_LIBS * sizeof(u32));
688 goto err;
689 }
690 }
691
692 start_code = textpos + sizeof(struct flat_hdr);
693 end_code = textpos + text_len;
694 text_len -= sizeof(struct flat_hdr); /* the real code len */
695
696 /* The main program needs a little extra setup in the task structure */
697 if (id == 0) {
698 current->mm->start_code = start_code;
699 current->mm->end_code = end_code;
700 current->mm->start_data = datapos;
701 current->mm->end_data = datapos + data_len;
702 /*
703 * set up the brk stuff, uses any slack left in data/bss/stack
704 * allocation. We put the brk after the bss (between the bss
705 * and stack) like other platforms.
706 * Userspace code relies on the stack pointer starting out at
707 * an address right at the end of a page.
708 */
709 current->mm->start_brk = datapos + data_len + bss_len;
710 current->mm->brk = (current->mm->start_brk + 3) & ~3;
711 #ifndef CONFIG_MMU
712 current->mm->context.end_brk = memp + memp_size - stack_len;
713 #endif
714 }
715
716 if (flags & FLAT_FLAG_KTRACE) {
717 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
718 textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
719 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
720 id ? "Lib" : "Load", bprm->filename,
721 start_code, end_code, datapos, datapos + data_len,
722 datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
723 }
724
725 /* Store the current module values into the global library structure */
726 libinfo->lib_list[id].start_code = start_code;
727 libinfo->lib_list[id].start_data = datapos;
728 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
729 libinfo->lib_list[id].text_len = text_len;
730 libinfo->lib_list[id].loaded = 1;
731 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
732 libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
733
734 /*
735 * We just load the allocations into some temporary memory to
736 * help simplify all this mumbo jumbo
737 *
738 * We've got two different sections of relocation entries.
739 * The first is the GOT which resides at the beginning of the data segment
740 * and is terminated with a -1. This one can be relocated in place.
741 * The second is the extra relocation entries tacked after the image's
742 * data segment. These require a little more processing as the entry is
743 * really an offset into the image which contains an offset into the
744 * image.
745 */
746 if (flags & FLAT_FLAG_GOTPIC) {
747 for (rp = (u32 __user *)datapos; ; rp++) {
748 u32 addr, rp_val;
749 if (get_user(rp_val, rp))
750 return -EFAULT;
751 if (rp_val == 0xffffffff)
752 break;
753 if (rp_val) {
754 addr = calc_reloc(rp_val, libinfo, id, 0);
755 if (addr == RELOC_FAILED) {
756 ret = -ENOEXEC;
757 goto err;
758 }
759 if (put_user(addr, rp))
760 return -EFAULT;
761 }
762 }
763 }
764
765 /*
766 * Now run through the relocation entries.
767 * We've got to be careful here as C++ produces relocatable zero
768 * entries in the constructor and destructor tables which are then
769 * tested for being not zero (which will always occur unless we're
770 * based from address zero). This causes an endless loop as __start
771 * is at zero. The solution used is to not relocate zero addresses.
772 * This has the negative side effect of not allowing a global data
773 * reference to be statically initialised to _stext (I've moved
774 * __start to address 4 so that is okay).
775 */
776 if (rev > OLD_FLAT_VERSION) {
777 u32 __maybe_unused persistent = 0;
778 for (i = 0; i < relocs; i++) {
779 u32 addr, relval;
780
781 /*
782 * Get the address of the pointer to be
783 * relocated (of course, the address has to be
784 * relocated first).
785 */
786 if (get_user(relval, reloc + i))
787 return -EFAULT;
788 relval = ntohl(relval);
789 if (flat_set_persistent(relval, &persistent))
790 continue;
791 addr = flat_get_relocate_addr(relval);
792 rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
793 if (rp == (u32 __user *)RELOC_FAILED) {
794 ret = -ENOEXEC;
795 goto err;
796 }
797
798 /* Get the pointer's value. */
799 ret = flat_get_addr_from_rp(rp, relval, flags,
800 &addr, &persistent);
801 if (unlikely(ret))
802 goto err;
803
804 if (addr != 0) {
805 /*
806 * Do the relocation. PIC relocs in the data section are
807 * already in target order
808 */
809 if ((flags & FLAT_FLAG_GOTPIC) == 0)
810 addr = ntohl(addr);
811 addr = calc_reloc(addr, libinfo, id, 0);
812 if (addr == RELOC_FAILED) {
813 ret = -ENOEXEC;
814 goto err;
815 }
816
817 /* Write back the relocated pointer. */
818 ret = flat_put_addr_at_rp(rp, addr, relval);
819 if (unlikely(ret))
820 goto err;
821 }
822 }
823 } else {
824 for (i = 0; i < relocs; i++) {
825 u32 relval;
826 if (get_user(relval, reloc + i))
827 return -EFAULT;
828 relval = ntohl(relval);
829 old_reloc(relval);
830 }
831 }
832
833 flush_icache_range(start_code, end_code);
834
835 /* zero the BSS, BRK and stack areas */
836 if (clear_user((void __user *)(datapos + data_len), bss_len +
837 (memp + memp_size - stack_len - /* end brk */
838 libinfo->lib_list[id].start_brk) + /* start brk */
839 stack_len))
840 return -EFAULT;
841
842 return 0;
843 err:
844 return ret;
845 }
846
847
848 /****************************************************************************/
849 #ifdef CONFIG_BINFMT_SHARED_FLAT
850
851 /*
852 * Load a shared library into memory. The library gets its own data
853 * segment (including bss) but not argv/argc/environ.
854 */
855
856 static int load_flat_shared_library(int id, struct lib_info *libs)
857 {
858 struct linux_binprm bprm;
859 int res;
860 char buf[16];
861
862 memset(&bprm, 0, sizeof(bprm));
863
864 /* Create the file name */
865 sprintf(buf, "/lib/lib%d.so", id);
866
867 /* Open the file up */
868 bprm.filename = buf;
869 bprm.file = open_exec(bprm.filename);
870 res = PTR_ERR(bprm.file);
871 if (IS_ERR(bprm.file))
872 return res;
873
874 bprm.cred = prepare_exec_creds();
875 res = -ENOMEM;
876 if (!bprm.cred)
877 goto out;
878
879 /* We don't really care about recalculating credentials at this point
880 * as we're past the point of no return and are dealing with shared
881 * libraries.
882 */
883 bprm.called_set_creds = 1;
884
885 res = prepare_binprm(&bprm);
886
887 if (!res)
888 res = load_flat_file(&bprm, libs, id, NULL);
889
890 abort_creds(bprm.cred);
891
892 out:
893 allow_write_access(bprm.file);
894 fput(bprm.file);
895
896 return res;
897 }
898
899 #endif /* CONFIG_BINFMT_SHARED_FLAT */
900 /****************************************************************************/
901
902 /*
903 * These are the functions used to load flat style executables and shared
904 * libraries. There is no binary dependent code anywhere else.
905 */
906
907 static int load_flat_binary(struct linux_binprm *bprm)
908 {
909 struct lib_info libinfo;
910 struct pt_regs *regs = current_pt_regs();
911 unsigned long stack_len = 0;
912 unsigned long start_addr;
913 int res;
914 int i, j;
915
916 memset(&libinfo, 0, sizeof(libinfo));
917
918 /*
919 * We have to add the size of our arguments to our stack size
920 * otherwise it's too easy for users to create stack overflows
921 * by passing in a huge argument list. And yes, we have to be
922 * pedantic and include space for the argv/envp array as it may have
923 * a lot of entries.
924 */
925 #ifndef CONFIG_MMU
926 stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
927 #endif
928 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
929 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
930 stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
931
932 res = load_flat_file(bprm, &libinfo, 0, &stack_len);
933 if (res < 0)
934 return res;
935
936 /* Update data segment pointers for all libraries */
937 for (i = 0; i < MAX_SHARED_LIBS; i++) {
938 if (!libinfo.lib_list[i].loaded)
939 continue;
940 for (j = 0; j < MAX_SHARED_LIBS; j++) {
941 unsigned long val = libinfo.lib_list[j].loaded ?
942 libinfo.lib_list[j].start_data : UNLOADED_LIB;
943 unsigned long __user *p = (unsigned long __user *)
944 libinfo.lib_list[i].start_data;
945 p -= j + 1;
946 if (put_user(val, p))
947 return -EFAULT;
948 }
949 }
950
951 install_exec_creds(bprm);
952
953 set_binfmt(&flat_format);
954
955 #ifdef CONFIG_MMU
956 res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
957 if (!res)
958 res = create_flat_tables(bprm, bprm->p);
959 #else
960 /* Stash our initial stack pointer into the mm structure */
961 current->mm->start_stack =
962 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
963 pr_debug("sp=%lx\n", current->mm->start_stack);
964
965 /* copy the arg pages onto the stack */
966 res = transfer_args_to_stack(bprm, &current->mm->start_stack);
967 if (!res)
968 res = create_flat_tables(bprm, current->mm->start_stack);
969 #endif
970 if (res)
971 return res;
972
973 /* Fake some return addresses to ensure the call chain will
974 * initialise library in order for us. We are required to call
975 * lib 1 first, then 2, ... and finally the main program (id 0).
976 */
977 start_addr = libinfo.lib_list[0].entry;
978
979 #ifdef CONFIG_BINFMT_SHARED_FLAT
980 for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
981 if (libinfo.lib_list[i].loaded) {
982 /* Push previos first to call address */
983 unsigned long __user *sp;
984 current->mm->start_stack -= sizeof(unsigned long);
985 sp = (unsigned long __user *)current->mm->start_stack;
986 __put_user(start_addr, sp);
987 start_addr = libinfo.lib_list[i].entry;
988 }
989 }
990 #endif
991
992 #ifdef FLAT_PLAT_INIT
993 FLAT_PLAT_INIT(regs);
994 #endif
995
996 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
997 regs, start_addr, current->mm->start_stack);
998 start_thread(regs, start_addr, current->mm->start_stack);
999
1000 return 0;
1001 }
1002
1003 /****************************************************************************/
1004
1005 static int __init init_flat_binfmt(void)
1006 {
1007 register_binfmt(&flat_format);
1008 return 0;
1009 }
1010 core_initcall(init_flat_binfmt);
1011
1012 /****************************************************************************/