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