projects/linux·blob v4.3 · refs

953 lines · 26.4 KiB

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