1 // SPDX-License-Identifier: GPL-2.0
2 /****************************************************************************/
3 /*
4 * linux/fs/binfmt_flat.c
5 *
6 * Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com>
7 * Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com>
8 * Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com>
9 * Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com>
10 * based heavily on:
11 *
12 * linux/fs/binfmt_aout.c:
13 * Copyright (C) 1991, 1992, 1996 Linus Torvalds
14 * linux/fs/binfmt_flat.c for 2.0 kernel
15 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>
16 * JAN/99 -- coded full program relocation (gerg@snapgear.com)
17 */
18
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
21 #include <linux/kernel.h>
22 #include <linux/sched.h>
23 #include <linux/sched/task_stack.h>
24 #include <linux/mm.h>
25 #include <linux/mman.h>
26 #include <linux/errno.h>
27 #include <linux/signal.h>
28 #include <linux/string.h>
29 #include <linux/fs.h>
30 #include <linux/file.h>
31 #include <linux/ptrace.h>
32 #include <linux/user.h>
33 #include <linux/slab.h>
34 #include <linux/binfmts.h>
35 #include <linux/personality.h>
36 #include <linux/init.h>
37 #include <linux/flat.h>
38 #include <linux/uaccess.h>
39 #include <linux/vmalloc.h>
40
41 #include <asm/byteorder.h>
42 #include <asm/unaligned.h>
43 #include <asm/cacheflush.h>
44 #include <asm/page.h>
45 #include <asm/flat.h>
46
47 #ifndef flat_get_relocate_addr
48 #define flat_get_relocate_addr(rel) (rel)
49 #endif
50
51 /****************************************************************************/
52
53 /*
54 * User data (data section and bss) needs to be aligned.
55 * We pick 0x20 here because it is the max value elf2flt has always
56 * used in producing FLAT files, and because it seems to be large
57 * enough to make all the gcc alignment related tests happy.
58 */
59 #define FLAT_DATA_ALIGN (0x20)
60
61 /*
62 * User data (stack) also needs to be aligned.
63 * Here we can be a bit looser than the data sections since this
64 * needs to only meet arch ABI requirements.
65 */
66 #define FLAT_STACK_ALIGN max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN)
67
68 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
69 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
70
71 #ifdef CONFIG_BINFMT_SHARED_FLAT
72 #define MAX_SHARED_LIBS (4)
73 #else
74 #define MAX_SHARED_LIBS (1)
75 #endif
76
77 struct lib_info {
78 struct {
79 unsigned long start_code; /* Start of text segment */
80 unsigned long start_data; /* Start of data segment */
81 unsigned long start_brk; /* End of data segment */
82 unsigned long text_len; /* Length of text segment */
83 unsigned long entry; /* Start address for this module */
84 unsigned long build_date; /* When this one was compiled */
85 bool loaded; /* Has this library been loaded? */
86 } lib_list[MAX_SHARED_LIBS];
87 };
88
89 #ifdef CONFIG_BINFMT_SHARED_FLAT
90 static int load_flat_shared_library(int id, struct lib_info *p);
91 #endif
92
93 static int load_flat_binary(struct linux_binprm *);
94 static int flat_core_dump(struct coredump_params *cprm);
95
96 static struct linux_binfmt flat_format = {
97 .module = THIS_MODULE,
98 .load_binary = load_flat_binary,
99 .core_dump = flat_core_dump,
100 .min_coredump = PAGE_SIZE
101 };
102
103 /****************************************************************************/
104 /*
105 * Routine writes a core dump image in the current directory.
106 * Currently only a stub-function.
107 */
108
flat_core_dump(struct coredump_params * cprm)109 static int flat_core_dump(struct coredump_params *cprm)
110 {
111 pr_warn("Process %s:%d received signr %d and should have core dumped\n",
112 current->comm, current->pid, cprm->siginfo->si_signo);
113 return 1;
114 }
115
116 /****************************************************************************/
117 /*
118 * create_flat_tables() parses the env- and arg-strings in new user
119 * memory and creates the pointer tables from them, and puts their
120 * addresses on the "stack", recording the new stack pointer value.
121 */
122
create_flat_tables(struct linux_binprm * bprm,unsigned long arg_start)123 static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start)
124 {
125 char __user *p;
126 unsigned long __user *sp;
127 long i, len;
128
129 p = (char __user *)arg_start;
130 sp = (unsigned long __user *)current->mm->start_stack;
131
132 sp -= bprm->envc + 1;
133 sp -= bprm->argc + 1;
134 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK))
135 sp -= 2; /* argvp + envp */
136 sp -= 1; /* &argc */
137
138 current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
139 sp = (unsigned long __user *)current->mm->start_stack;
140
141 if (put_user(bprm->argc, sp++))
142 return -EFAULT;
143 if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
144 unsigned long argv, envp;
145 argv = (unsigned long)(sp + 2);
146 envp = (unsigned long)(sp + 2 + bprm->argc + 1);
147 if (put_user(argv, sp++) || put_user(envp, sp++))
148 return -EFAULT;
149 }
150
151 current->mm->arg_start = (unsigned long)p;
152 for (i = bprm->argc; i > 0; i--) {
153 if (put_user((unsigned long)p, sp++))
154 return -EFAULT;
155 len = strnlen_user(p, MAX_ARG_STRLEN);
156 if (!len || len > MAX_ARG_STRLEN)
157 return -EINVAL;
158 p += len;
159 }
160 if (put_user(0, sp++))
161 return -EFAULT;
162 current->mm->arg_end = (unsigned long)p;
163
164 current->mm->env_start = (unsigned long) p;
165 for (i = bprm->envc; i > 0; i--) {
166 if (put_user((unsigned long)p, sp++))
167 return -EFAULT;
168 len = strnlen_user(p, MAX_ARG_STRLEN);
169 if (!len || len > MAX_ARG_STRLEN)
170 return -EINVAL;
171 p += len;
172 }
173 if (put_user(0, sp++))
174 return -EFAULT;
175 current->mm->env_end = (unsigned long)p;
176
177 return 0;
178 }
179
180 /****************************************************************************/
181
182 #ifdef CONFIG_BINFMT_ZFLAT
183
184 #include <linux/zlib.h>
185
186 #define LBUFSIZE 4000
187
188 /* gzip flag byte */
189 #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
190 #define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
191 #define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
192 #define ORIG_NAME 0x08 /* bit 3 set: original file name present */
193 #define COMMENT 0x10 /* bit 4 set: file comment present */
194 #define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
195 #define RESERVED 0xC0 /* bit 6,7: reserved */
196
decompress_exec(struct linux_binprm * bprm,loff_t fpos,char * dst,long len,int fd)197 static int decompress_exec(struct linux_binprm *bprm, loff_t fpos, char *dst,
198 long len, int fd)
199 {
200 unsigned char *buf;
201 z_stream strm;
202 int ret, retval;
203
204 pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
205
206 memset(&strm, 0, sizeof(strm));
207 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
208 if (!strm.workspace)
209 return -ENOMEM;
210
211 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
212 if (!buf) {
213 retval = -ENOMEM;
214 goto out_free;
215 }
216
217 /* Read in first chunk of data and parse gzip header. */
218 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
219
220 strm.next_in = buf;
221 strm.avail_in = ret;
222 strm.total_in = 0;
223
224 retval = -ENOEXEC;
225
226 /* Check minimum size -- gzip header */
227 if (ret < 10) {
228 pr_debug("file too small?\n");
229 goto out_free_buf;
230 }
231
232 /* Check gzip magic number */
233 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
234 pr_debug("unknown compression magic?\n");
235 goto out_free_buf;
236 }
237
238 /* Check gzip method */
239 if (buf[2] != 8) {
240 pr_debug("unknown compression method?\n");
241 goto out_free_buf;
242 }
243 /* Check gzip flags */
244 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
245 (buf[3] & RESERVED)) {
246 pr_debug("unknown flags?\n");
247 goto out_free_buf;
248 }
249
250 ret = 10;
251 if (buf[3] & EXTRA_FIELD) {
252 ret += 2 + buf[10] + (buf[11] << 8);
253 if (unlikely(ret >= LBUFSIZE)) {
254 pr_debug("buffer overflow (EXTRA)?\n");
255 goto out_free_buf;
256 }
257 }
258 if (buf[3] & ORIG_NAME) {
259 while (ret < LBUFSIZE && buf[ret++] != 0)
260 ;
261 if (unlikely(ret == LBUFSIZE)) {
262 pr_debug("buffer overflow (ORIG_NAME)?\n");
263 goto out_free_buf;
264 }
265 }
266 if (buf[3] & COMMENT) {
267 while (ret < LBUFSIZE && buf[ret++] != 0)
268 ;
269 if (unlikely(ret == LBUFSIZE)) {
270 pr_debug("buffer overflow (COMMENT)?\n");
271 goto out_free_buf;
272 }
273 }
274
275 strm.next_in += ret;
276 strm.avail_in -= ret;
277
278 strm.next_out = dst;
279 strm.avail_out = len;
280 strm.total_out = 0;
281
282 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
283 pr_debug("zlib init failed?\n");
284 goto out_free_buf;
285 }
286
287 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
288 ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
289 if (ret <= 0)
290 break;
291 len -= ret;
292
293 strm.next_in = buf;
294 strm.avail_in = ret;
295 strm.total_in = 0;
296 }
297
298 if (ret < 0) {
299 pr_debug("decompression failed (%d), %s\n",
300 ret, strm.msg);
301 goto out_zlib;
302 }
303
304 retval = 0;
305 out_zlib:
306 zlib_inflateEnd(&strm);
307 out_free_buf:
308 kfree(buf);
309 out_free:
310 kfree(strm.workspace);
311 return retval;
312 }
313
314 #endif /* CONFIG_BINFMT_ZFLAT */
315
316 /****************************************************************************/
317
318 static unsigned long
calc_reloc(unsigned long r,struct lib_info * p,int curid,int internalp)319 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
320 {
321 unsigned long addr;
322 int id;
323 unsigned long start_brk;
324 unsigned long start_data;
325 unsigned long text_len;
326 unsigned long start_code;
327
328 #ifdef CONFIG_BINFMT_SHARED_FLAT
329 if (r == 0)
330 id = curid; /* Relocs of 0 are always self referring */
331 else {
332 id = (r >> 24) & 0xff; /* Find ID for this reloc */
333 r &= 0x00ffffff; /* Trim ID off here */
334 }
335 if (id >= MAX_SHARED_LIBS) {
336 pr_err("reference 0x%lx to shared library %d", r, id);
337 goto failed;
338 }
339 if (curid != id) {
340 if (internalp) {
341 pr_err("reloc address 0x%lx not in same module "
342 "(%d != %d)", r, curid, id);
343 goto failed;
344 } else if (!p->lib_list[id].loaded &&
345 load_flat_shared_library(id, p) < 0) {
346 pr_err("failed to load library %d", id);
347 goto failed;
348 }
349 /* Check versioning information (i.e. time stamps) */
350 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
351 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
352 pr_err("library %d is younger than %d", id, curid);
353 goto failed;
354 }
355 }
356 #else
357 id = 0;
358 #endif
359
360 start_brk = p->lib_list[id].start_brk;
361 start_data = p->lib_list[id].start_data;
362 start_code = p->lib_list[id].start_code;
363 text_len = p->lib_list[id].text_len;
364
365 if (r > start_brk - start_data + text_len) {
366 pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",
367 r, start_brk-start_data+text_len, text_len);
368 goto failed;
369 }
370
371 if (r < text_len) /* In text segment */
372 addr = r + start_code;
373 else /* In data segment */
374 addr = r - text_len + start_data;
375
376 /* Range checked already above so doing the range tests is redundant...*/
377 return addr;
378
379 failed:
380 pr_cont(", killing %s!\n", current->comm);
381 send_sig(SIGSEGV, current, 0);
382
383 return RELOC_FAILED;
384 }
385
386 /****************************************************************************/
387
388 #ifdef CONFIG_BINFMT_FLAT_OLD
old_reloc(unsigned long rl)389 static void old_reloc(unsigned long rl)
390 {
391 static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
392 flat_v2_reloc_t r;
393 unsigned long __user *ptr;
394 unsigned long val;
395
396 r.value = rl;
397 #if defined(CONFIG_COLDFIRE)
398 ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);
399 #else
400 ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);
401 #endif
402 get_user(val, ptr);
403
404 pr_debug("Relocation of variable at DATASEG+%x "
405 "(address %p, currently %lx) into segment %s\n",
406 r.reloc.offset, ptr, val, segment[r.reloc.type]);
407
408 switch (r.reloc.type) {
409 case OLD_FLAT_RELOC_TYPE_TEXT:
410 val += current->mm->start_code;
411 break;
412 case OLD_FLAT_RELOC_TYPE_DATA:
413 val += current->mm->start_data;
414 break;
415 case OLD_FLAT_RELOC_TYPE_BSS:
416 val += current->mm->end_data;
417 break;
418 default:
419 pr_err("Unknown relocation type=%x\n", r.reloc.type);
420 break;
421 }
422 put_user(val, ptr);
423
424 pr_debug("Relocation became %lx\n", val);
425 }
426 #endif /* CONFIG_BINFMT_FLAT_OLD */
427
428 /****************************************************************************/
429
skip_got_header(u32 __user * rp)430 static inline u32 __user *skip_got_header(u32 __user *rp)
431 {
432 if (IS_ENABLED(CONFIG_RISCV)) {
433 /*
434 * RISC-V has a 16 byte GOT PLT header for elf64-riscv
435 * and 8 byte GOT PLT header for elf32-riscv.
436 * Skip the whole GOT PLT header, since it is reserved
437 * for the dynamic linker (ld.so).
438 */
439 u32 rp_val0, rp_val1;
440
441 if (get_user(rp_val0, rp))
442 return rp;
443 if (get_user(rp_val1, rp + 1))
444 return rp;
445
446 if (rp_val0 == 0xffffffff && rp_val1 == 0xffffffff)
447 rp += 4;
448 else if (rp_val0 == 0xffffffff)
449 rp += 2;
450 }
451 return rp;
452 }
453
load_flat_file(struct linux_binprm * bprm,struct lib_info * libinfo,int id,unsigned long * extra_stack)454 static int load_flat_file(struct linux_binprm *bprm,
455 struct lib_info *libinfo, int id, unsigned long *extra_stack)
456 {
457 struct flat_hdr *hdr;
458 unsigned long textpos, datapos, realdatastart;
459 u32 text_len, data_len, bss_len, stack_len, full_data, flags;
460 unsigned long len, memp, memp_size, extra, rlim;
461 __be32 __user *reloc;
462 u32 __user *rp;
463 int i, rev, relocs;
464 loff_t fpos;
465 unsigned long start_code, end_code;
466 ssize_t result;
467 int ret;
468
469 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
470
471 text_len = ntohl(hdr->data_start);
472 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
473 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
474 stack_len = ntohl(hdr->stack_size);
475 if (extra_stack) {
476 stack_len += *extra_stack;
477 *extra_stack = stack_len;
478 }
479 relocs = ntohl(hdr->reloc_count);
480 flags = ntohl(hdr->flags);
481 rev = ntohl(hdr->rev);
482 full_data = data_len + relocs * sizeof(unsigned long);
483
484 if (strncmp(hdr->magic, "bFLT", 4)) {
485 /*
486 * Previously, here was a printk to tell people
487 * "BINFMT_FLAT: bad header magic".
488 * But for the kernel which also use ELF FD-PIC format, this
489 * error message is confusing.
490 * because a lot of people do not manage to produce good
491 */
492 ret = -ENOEXEC;
493 goto err;
494 }
495
496 if (flags & FLAT_FLAG_KTRACE)
497 pr_info("Loading file: %s\n", bprm->filename);
498
499 #ifdef CONFIG_BINFMT_FLAT_OLD
500 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
501 pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",
502 rev, FLAT_VERSION, OLD_FLAT_VERSION);
503 ret = -ENOEXEC;
504 goto err;
505 }
506
507 /* Don't allow old format executables to use shared libraries */
508 if (rev == OLD_FLAT_VERSION && id != 0) {
509 pr_err("shared libraries are not available before rev 0x%lx\n",
510 FLAT_VERSION);
511 ret = -ENOEXEC;
512 goto err;
513 }
514
515 /*
516 * fix up the flags for the older format, there were all kinds
517 * of endian hacks, this only works for the simple cases
518 */
519 if (rev == OLD_FLAT_VERSION &&
520 (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
521 flags = FLAT_FLAG_RAM;
522
523 #else /* CONFIG_BINFMT_FLAT_OLD */
524 if (rev != FLAT_VERSION) {
525 pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
526 rev, FLAT_VERSION);
527 ret = -ENOEXEC;
528 goto err;
529 }
530 #endif /* !CONFIG_BINFMT_FLAT_OLD */
531
532 /*
533 * Make sure the header params are sane.
534 * 28 bits (256 MB) is way more than reasonable in this case.
535 * If some top bits are set we have probable binary corruption.
536 */
537 if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
538 pr_err("bad header\n");
539 ret = -ENOEXEC;
540 goto err;
541 }
542
543 #ifndef CONFIG_BINFMT_ZFLAT
544 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
545 pr_err("Support for ZFLAT executables is not enabled.\n");
546 ret = -ENOEXEC;
547 goto err;
548 }
549 #endif
550
551 /*
552 * Check initial limits. This avoids letting people circumvent
553 * size limits imposed on them by creating programs with large
554 * arrays in the data or bss.
555 */
556 rlim = rlimit(RLIMIT_DATA);
557 if (rlim >= RLIM_INFINITY)
558 rlim = ~0;
559 if (data_len + bss_len > rlim) {
560 ret = -ENOMEM;
561 goto err;
562 }
563
564 /* Flush all traces of the currently running executable */
565 if (id == 0) {
566 ret = begin_new_exec(bprm);
567 if (ret)
568 goto err;
569
570 /* OK, This is the point of no return */
571 set_personality(PER_LINUX_32BIT);
572 setup_new_exec(bprm);
573 }
574
575 /*
576 * calculate the extra space we need to map in
577 */
578 extra = max_t(unsigned long, bss_len + stack_len,
579 relocs * sizeof(unsigned long));
580
581 /*
582 * there are a couple of cases here, the separate code/data
583 * case, and then the fully copied to RAM case which lumps
584 * it all together.
585 */
586 if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
587 /*
588 * this should give us a ROM ptr, but if it doesn't we don't
589 * really care
590 */
591 pr_debug("ROM mapping of file (we hope)\n");
592
593 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
594 MAP_PRIVATE|MAP_EXECUTABLE, 0);
595 if (!textpos || IS_ERR_VALUE(textpos)) {
596 ret = textpos;
597 if (!textpos)
598 ret = -ENOMEM;
599 pr_err("Unable to mmap process text, errno %d\n", ret);
600 goto err;
601 }
602
603 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
604 len = PAGE_ALIGN(len);
605 realdatastart = vm_mmap(NULL, 0, len,
606 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
607
608 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
609 ret = realdatastart;
610 if (!realdatastart)
611 ret = -ENOMEM;
612 pr_err("Unable to allocate RAM for process data, "
613 "errno %d\n", ret);
614 vm_munmap(textpos, text_len);
615 goto err;
616 }
617 datapos = ALIGN(realdatastart +
618 MAX_SHARED_LIBS * sizeof(unsigned long),
619 FLAT_DATA_ALIGN);
620
621 pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
622 data_len + bss_len + stack_len, datapos);
623
624 fpos = ntohl(hdr->data_start);
625 #ifdef CONFIG_BINFMT_ZFLAT
626 if (flags & FLAT_FLAG_GZDATA) {
627 result = decompress_exec(bprm, fpos, (char *)datapos,
628 full_data, 0);
629 } else
630 #endif
631 {
632 result = read_code(bprm->file, datapos, fpos,
633 full_data);
634 }
635 if (IS_ERR_VALUE(result)) {
636 ret = result;
637 pr_err("Unable to read data+bss, errno %d\n", ret);
638 vm_munmap(textpos, text_len);
639 vm_munmap(realdatastart, len);
640 goto err;
641 }
642
643 reloc = (__be32 __user *)
644 (datapos + (ntohl(hdr->reloc_start) - text_len));
645 memp = realdatastart;
646 memp_size = len;
647 } else {
648
649 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);
650 len = PAGE_ALIGN(len);
651 textpos = vm_mmap(NULL, 0, len,
652 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
653
654 if (!textpos || IS_ERR_VALUE(textpos)) {
655 ret = textpos;
656 if (!textpos)
657 ret = -ENOMEM;
658 pr_err("Unable to allocate RAM for process text/data, "
659 "errno %d\n", ret);
660 goto err;
661 }
662
663 realdatastart = textpos + ntohl(hdr->data_start);
664 datapos = ALIGN(realdatastart +
665 MAX_SHARED_LIBS * sizeof(u32),
666 FLAT_DATA_ALIGN);
667
668 reloc = (__be32 __user *)
669 (datapos + (ntohl(hdr->reloc_start) - text_len));
670 memp = textpos;
671 memp_size = len;
672 #ifdef CONFIG_BINFMT_ZFLAT
673 /*
674 * load it all in and treat it like a RAM load from now on
675 */
676 if (flags & FLAT_FLAG_GZIP) {
677 #ifndef CONFIG_MMU
678 result = decompress_exec(bprm, sizeof(struct flat_hdr),
679 (((char *)textpos) + sizeof(struct flat_hdr)),
680 (text_len + full_data
681 - sizeof(struct flat_hdr)),
682 0);
683 memmove((void *) datapos, (void *) realdatastart,
684 full_data);
685 #else
686 /*
687 * This is used on MMU systems mainly for testing.
688 * Let's use a kernel buffer to simplify things.
689 */
690 long unz_text_len = text_len - sizeof(struct flat_hdr);
691 long unz_len = unz_text_len + full_data;
692 char *unz_data = vmalloc(unz_len);
693 if (!unz_data) {
694 result = -ENOMEM;
695 } else {
696 result = decompress_exec(bprm, sizeof(struct flat_hdr),
697 unz_data, unz_len, 0);
698 if (result == 0 &&
699 (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
700 unz_data, unz_text_len) ||
701 copy_to_user((void __user *)datapos,
702 unz_data + unz_text_len, full_data)))
703 result = -EFAULT;
704 vfree(unz_data);
705 }
706 #endif
707 } else if (flags & FLAT_FLAG_GZDATA) {
708 result = read_code(bprm->file, textpos, 0, text_len);
709 if (!IS_ERR_VALUE(result)) {
710 #ifndef CONFIG_MMU
711 result = decompress_exec(bprm, text_len, (char *) datapos,
712 full_data, 0);
713 #else
714 char *unz_data = vmalloc(full_data);
715 if (!unz_data) {
716 result = -ENOMEM;
717 } else {
718 result = decompress_exec(bprm, text_len,
719 unz_data, full_data, 0);
720 if (result == 0 &&
721 copy_to_user((void __user *)datapos,
722 unz_data, full_data))
723 result = -EFAULT;
724 vfree(unz_data);
725 }
726 #endif
727 }
728 } else
729 #endif /* CONFIG_BINFMT_ZFLAT */
730 {
731 result = read_code(bprm->file, textpos, 0, text_len);
732 if (!IS_ERR_VALUE(result))
733 result = read_code(bprm->file, datapos,
734 ntohl(hdr->data_start),
735 full_data);
736 }
737 if (IS_ERR_VALUE(result)) {
738 ret = result;
739 pr_err("Unable to read code+data+bss, errno %d\n", ret);
740 vm_munmap(textpos, text_len + data_len + extra +
741 MAX_SHARED_LIBS * sizeof(u32));
742 goto err;
743 }
744 }
745
746 start_code = textpos + sizeof(struct flat_hdr);
747 end_code = textpos + text_len;
748 text_len -= sizeof(struct flat_hdr); /* the real code len */
749
750 /* The main program needs a little extra setup in the task structure */
751 if (id == 0) {
752 current->mm->start_code = start_code;
753 current->mm->end_code = end_code;
754 current->mm->start_data = datapos;
755 current->mm->end_data = datapos + data_len;
756 /*
757 * set up the brk stuff, uses any slack left in data/bss/stack
758 * allocation. We put the brk after the bss (between the bss
759 * and stack) like other platforms.
760 * Userspace code relies on the stack pointer starting out at
761 * an address right at the end of a page.
762 */
763 current->mm->start_brk = datapos + data_len + bss_len;
764 current->mm->brk = (current->mm->start_brk + 3) & ~3;
765 #ifndef CONFIG_MMU
766 current->mm->context.end_brk = memp + memp_size - stack_len;
767 #endif
768 }
769
770 if (flags & FLAT_FLAG_KTRACE) {
771 pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
772 textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
773 pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
774 id ? "Lib" : "Load", bprm->filename,
775 start_code, end_code, datapos, datapos + data_len,
776 datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
777 }
778
779 /* Store the current module values into the global library structure */
780 libinfo->lib_list[id].start_code = start_code;
781 libinfo->lib_list[id].start_data = datapos;
782 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
783 libinfo->lib_list[id].text_len = text_len;
784 libinfo->lib_list[id].loaded = 1;
785 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
786 libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
787
788 /*
789 * We just load the allocations into some temporary memory to
790 * help simplify all this mumbo jumbo
791 *
792 * We've got two different sections of relocation entries.
793 * The first is the GOT which resides at the beginning of the data segment
794 * and is terminated with a -1. This one can be relocated in place.
795 * The second is the extra relocation entries tacked after the image's
796 * data segment. These require a little more processing as the entry is
797 * really an offset into the image which contains an offset into the
798 * image.
799 */
800 if (flags & FLAT_FLAG_GOTPIC) {
801 rp = skip_got_header((u32 __user *) datapos);
802 for (; ; rp++) {
803 u32 addr, rp_val;
804 if (get_user(rp_val, rp))
805 return -EFAULT;
806 if (rp_val == 0xffffffff)
807 break;
808 if (rp_val) {
809 addr = calc_reloc(rp_val, libinfo, id, 0);
810 if (addr == RELOC_FAILED) {
811 ret = -ENOEXEC;
812 goto err;
813 }
814 if (put_user(addr, rp))
815 return -EFAULT;
816 }
817 }
818 }
819
820 /*
821 * Now run through the relocation entries.
822 * We've got to be careful here as C++ produces relocatable zero
823 * entries in the constructor and destructor tables which are then
824 * tested for being not zero (which will always occur unless we're
825 * based from address zero). This causes an endless loop as __start
826 * is at zero. The solution used is to not relocate zero addresses.
827 * This has the negative side effect of not allowing a global data
828 * reference to be statically initialised to _stext (I've moved
829 * __start to address 4 so that is okay).
830 */
831 if (rev > OLD_FLAT_VERSION) {
832 for (i = 0; i < relocs; i++) {
833 u32 addr, relval;
834 __be32 tmp;
835
836 /*
837 * Get the address of the pointer to be
838 * relocated (of course, the address has to be
839 * relocated first).
840 */
841 if (get_user(tmp, reloc + i))
842 return -EFAULT;
843 relval = ntohl(tmp);
844 addr = flat_get_relocate_addr(relval);
845 rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
846 if (rp == (u32 __user *)RELOC_FAILED) {
847 ret = -ENOEXEC;
848 goto err;
849 }
850
851 /* Get the pointer's value. */
852 ret = flat_get_addr_from_rp(rp, relval, flags, &addr);
853 if (unlikely(ret))
854 goto err;
855
856 if (addr != 0) {
857 /*
858 * Do the relocation. PIC relocs in the data section are
859 * already in target order
860 */
861 if ((flags & FLAT_FLAG_GOTPIC) == 0) {
862 /*
863 * Meh, the same value can have a different
864 * byte order based on a flag..
865 */
866 addr = ntohl((__force __be32)addr);
867 }
868 addr = calc_reloc(addr, libinfo, id, 0);
869 if (addr == RELOC_FAILED) {
870 ret = -ENOEXEC;
871 goto err;
872 }
873
874 /* Write back the relocated pointer. */
875 ret = flat_put_addr_at_rp(rp, addr, relval);
876 if (unlikely(ret))
877 goto err;
878 }
879 }
880 #ifdef CONFIG_BINFMT_FLAT_OLD
881 } else {
882 for (i = 0; i < relocs; i++) {
883 __be32 relval;
884 if (get_user(relval, reloc + i))
885 return -EFAULT;
886 old_reloc(ntohl(relval));
887 }
888 #endif /* CONFIG_BINFMT_FLAT_OLD */
889 }
890
891 flush_icache_user_range(start_code, end_code);
892
893 /* zero the BSS, BRK and stack areas */
894 if (clear_user((void __user *)(datapos + data_len), bss_len +
895 (memp + memp_size - stack_len - /* end brk */
896 libinfo->lib_list[id].start_brk) + /* start brk */
897 stack_len))
898 return -EFAULT;
899
900 return 0;
901 err:
902 return ret;
903 }
904
905
906 /****************************************************************************/
907 #ifdef CONFIG_BINFMT_SHARED_FLAT
908
909 /*
910 * Load a shared library into memory. The library gets its own data
911 * segment (including bss) but not argv/argc/environ.
912 */
913
load_flat_shared_library(int id,struct lib_info * libs)914 static int load_flat_shared_library(int id, struct lib_info *libs)
915 {
916 /*
917 * This is a fake bprm struct; only the members "buf", "file" and
918 * "filename" are actually used.
919 */
920 struct linux_binprm bprm;
921 int res;
922 char buf[16];
923 loff_t pos = 0;
924
925 memset(&bprm, 0, sizeof(bprm));
926
927 /* Create the file name */
928 sprintf(buf, "/lib/lib%d.so", id);
929
930 /* Open the file up */
931 bprm.filename = buf;
932 bprm.file = open_exec(bprm.filename);
933 res = PTR_ERR(bprm.file);
934 if (IS_ERR(bprm.file))
935 return res;
936
937 res = kernel_read(bprm.file, bprm.buf, BINPRM_BUF_SIZE, &pos);
938
939 if (res >= 0)
940 res = load_flat_file(&bprm, libs, id, NULL);
941
942 allow_write_access(bprm.file);
943 fput(bprm.file);
944
945 return res;
946 }
947
948 #endif /* CONFIG_BINFMT_SHARED_FLAT */
949 /****************************************************************************/
950
951 /*
952 * These are the functions used to load flat style executables and shared
953 * libraries. There is no binary dependent code anywhere else.
954 */
955
load_flat_binary(struct linux_binprm * bprm)956 static int load_flat_binary(struct linux_binprm *bprm)
957 {
958 struct lib_info libinfo;
959 struct pt_regs *regs = current_pt_regs();
960 unsigned long stack_len = 0;
961 unsigned long start_addr;
962 int res;
963 int i, j;
964
965 memset(&libinfo, 0, sizeof(libinfo));
966
967 /*
968 * We have to add the size of our arguments to our stack size
969 * otherwise it's too easy for users to create stack overflows
970 * by passing in a huge argument list. And yes, we have to be
971 * pedantic and include space for the argv/envp array as it may have
972 * a lot of entries.
973 */
974 #ifndef CONFIG_MMU
975 stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
976 #endif
977 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
978 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
979 stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
980
981 res = load_flat_file(bprm, &libinfo, 0, &stack_len);
982 if (res < 0)
983 return res;
984
985 /* Update data segment pointers for all libraries */
986 for (i = 0; i < MAX_SHARED_LIBS; i++) {
987 if (!libinfo.lib_list[i].loaded)
988 continue;
989 for (j = 0; j < MAX_SHARED_LIBS; j++) {
990 unsigned long val = libinfo.lib_list[j].loaded ?
991 libinfo.lib_list[j].start_data : UNLOADED_LIB;
992 unsigned long __user *p = (unsigned long __user *)
993 libinfo.lib_list[i].start_data;
994 p -= j + 1;
995 if (put_user(val, p))
996 return -EFAULT;
997 }
998 }
999
1000 set_binfmt(&flat_format);
1001
1002 #ifdef CONFIG_MMU
1003 res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
1004 if (!res)
1005 res = create_flat_tables(bprm, bprm->p);
1006 #else
1007 /* Stash our initial stack pointer into the mm structure */
1008 current->mm->start_stack =
1009 ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
1010 pr_debug("sp=%lx\n", current->mm->start_stack);
1011
1012 /* copy the arg pages onto the stack */
1013 res = transfer_args_to_stack(bprm, ¤t->mm->start_stack);
1014 if (!res)
1015 res = create_flat_tables(bprm, current->mm->start_stack);
1016 #endif
1017 if (res)
1018 return res;
1019
1020 /* Fake some return addresses to ensure the call chain will
1021 * initialise library in order for us. We are required to call
1022 * lib 1 first, then 2, ... and finally the main program (id 0).
1023 */
1024 start_addr = libinfo.lib_list[0].entry;
1025
1026 #ifdef CONFIG_BINFMT_SHARED_FLAT
1027 for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
1028 if (libinfo.lib_list[i].loaded) {
1029 /* Push previos first to call address */
1030 unsigned long __user *sp;
1031 current->mm->start_stack -= sizeof(unsigned long);
1032 sp = (unsigned long __user *)current->mm->start_stack;
1033 if (put_user(start_addr, sp))
1034 return -EFAULT;
1035 start_addr = libinfo.lib_list[i].entry;
1036 }
1037 }
1038 #endif
1039
1040 #ifdef FLAT_PLAT_INIT
1041 FLAT_PLAT_INIT(regs);
1042 #endif
1043
1044 finalize_exec(bprm);
1045 pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
1046 regs, start_addr, current->mm->start_stack);
1047 start_thread(regs, start_addr, current->mm->start_stack);
1048
1049 return 0;
1050 }
1051
1052 /****************************************************************************/
1053
init_flat_binfmt(void)1054 static int __init init_flat_binfmt(void)
1055 {
1056 register_binfmt(&flat_format);
1057 return 0;
1058 }
1059 core_initcall(init_flat_binfmt);
1060
1061 /****************************************************************************/
1062