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 */
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>
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>
45 /****************************************************************************/
47 #if 0
48 #define DEBUG 1
49 #endif
51 #ifdef DEBUG
52 #define DBG_FLT(a...) printk(a)
53 #else
54 #define DBG_FLT(a...)
55 #endif
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)
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)
72 #define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
73 #define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
75 struct 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 };
87 #ifdef CONFIG_BINFMT_SHARED_FLAT
88 static int load_flat_shared_library(int id, struct lib_info *p);
89 #endif
91 static int load_flat_binary(struct linux_binprm *);
92 static int flat_core_dump(struct coredump_params *cprm);
94 static 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 };
101 /****************************************************************************/
102 /*
103 * Routine writes a core dump image in the current directory.
104 * Currently only a stub-function.
105 */
107 static 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 }
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 */
121 static 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);
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);
138 if (flat_argvp_envp_on_stack()) {
139 put_user((unsigned long) envp, sp + 2);
140 put_user((unsigned long) argv, sp + 1);
141 }
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 }
164 /****************************************************************************/
166 #ifdef CONFIG_BINFMT_ZFLAT
168 #include <linux/zlib.h>
170 #define LBUFSIZE 4000
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 */
181 static 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;
193 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
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 }
208 /* Read in first chunk of data and parse gzip header. */
209 fpos = offset;
210 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
212 strm.next_in = buf;
213 strm.avail_in = ret;
214 strm.total_in = 0;
216 retval = -ENOEXEC;
218 /* Check minimum size -- gzip header */
219 if (ret < 10) {
220 DBG_FLT("binfmt_flat: file too small?\n");
221 goto out_free_buf;
222 }
224 /* Check gzip magic number */
225 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
226 DBG_FLT("binfmt_flat: unknown compression magic?\n");
227 goto out_free_buf;
228 }
230 /* Check gzip method */
231 if (buf[2] != 8) {
232 DBG_FLT("binfmt_flat: unknown compression method?\n");
233 goto out_free_buf;
234 }
235 /* Check gzip flags */
236 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
237 (buf[3] & RESERVED)) {
238 DBG_FLT("binfmt_flat: unknown flags?\n");
239 goto out_free_buf;
240 }
242 ret = 10;
243 if (buf[3] & EXTRA_FIELD) {
244 ret += 2 + buf[10] + (buf[11] << 8);
245 if (unlikely(LBUFSIZE <= ret)) {
246 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
247 goto out_free_buf;
248 }
249 }
250 if (buf[3] & ORIG_NAME) {
251 while (ret < LBUFSIZE && buf[ret++] != 0)
252 ;
253 if (unlikely(LBUFSIZE == ret)) {
254 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
255 goto out_free_buf;
256 }
257 }
258 if (buf[3] & COMMENT) {
259 while (ret < LBUFSIZE && buf[ret++] != 0)
260 ;
261 if (unlikely(LBUFSIZE == ret)) {
262 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
263 goto out_free_buf;
264 }
265 }
267 strm.next_in += ret;
268 strm.avail_in -= ret;
270 strm.next_out = dst;
271 strm.avail_out = len;
272 strm.total_out = 0;
274 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
275 DBG_FLT("binfmt_flat: zlib init failed?\n");
276 goto out_free_buf;
277 }
279 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
280 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
281 if (ret <= 0)
282 break;
283 len -= ret;
285 strm.next_in = buf;
286 strm.avail_in = ret;
287 strm.total_in = 0;
288 }
290 if (ret < 0) {
291 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
292 ret, strm.msg);
293 goto out_zlib;
294 }
296 retval = 0;
297 out_zlib:
298 zlib_inflateEnd(&strm);
299 out_free_buf:
300 kfree(buf);
301 out_free:
302 kfree(strm.workspace);
303 return retval;
304 }
306 #endif /* CONFIG_BINFMT_ZFLAT */
308 /****************************************************************************/
310 static unsigned long
311 calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
312 {
313 unsigned long addr;
314 int id;
315 unsigned long start_brk;
316 unsigned long start_data;
317 unsigned long text_len;
318 unsigned long start_code;
320 #ifdef CONFIG_BINFMT_SHARED_FLAT
321 if (r == 0)
322 id = curid; /* Relocs of 0 are always self referring */
323 else {
324 id = (r >> 24) & 0xff; /* Find ID for this reloc */
325 r &= 0x00ffffff; /* Trim ID off here */
326 }
327 if (id >= MAX_SHARED_LIBS) {
328 printk("BINFMT_FLAT: reference 0x%x to shared library %d",
329 (unsigned) r, id);
330 goto failed;
331 }
332 if (curid != id) {
333 if (internalp) {
334 printk("BINFMT_FLAT: reloc address 0x%x not in same module "
335 "(%d != %d)", (unsigned) r, curid, id);
336 goto failed;
337 } else if ( ! p->lib_list[id].loaded &&
338 IS_ERR_VALUE(load_flat_shared_library(id, p))) {
339 printk("BINFMT_FLAT: failed to load library %d", id);
340 goto failed;
341 }
342 /* Check versioning information (i.e. time stamps) */
343 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
344 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
345 printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
346 goto failed;
347 }
348 }
349 #else
350 id = 0;
351 #endif
353 start_brk = p->lib_list[id].start_brk;
354 start_data = p->lib_list[id].start_data;
355 start_code = p->lib_list[id].start_code;
356 text_len = p->lib_list[id].text_len;
358 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
359 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
360 (int) r,(int)(start_brk-start_data+text_len),(int)text_len);
361 goto failed;
362 }
364 if (r < text_len) /* In text segment */
365 addr = r + start_code;
366 else /* In data segment */
367 addr = r - text_len + start_data;
369 /* Range checked already above so doing the range tests is redundant...*/
370 return(addr);
372 failed:
373 printk(", killing %s!\n", current->comm);
374 send_sig(SIGSEGV, current, 0);
376 return RELOC_FAILED;
377 }
379 /****************************************************************************/
381 void old_reloc(unsigned long rl)
382 {
383 #ifdef DEBUG
384 char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
385 #endif
386 flat_v2_reloc_t r;
387 unsigned long *ptr;
389 r.value = rl;
390 #if defined(CONFIG_COLDFIRE)
391 ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
392 #else
393 ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
394 #endif
396 #ifdef DEBUG
397 printk("Relocation of variable at DATASEG+%x "
398 "(address %p, currently %x) into segment %s\n",
399 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
400 #endif
402 switch (r.reloc.type) {
403 case OLD_FLAT_RELOC_TYPE_TEXT:
404 *ptr += current->mm->start_code;
405 break;
406 case OLD_FLAT_RELOC_TYPE_DATA:
407 *ptr += current->mm->start_data;
408 break;
409 case OLD_FLAT_RELOC_TYPE_BSS:
410 *ptr += current->mm->end_data;
411 break;
412 default:
413 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
414 break;
415 }
417 #ifdef DEBUG
418 printk("Relocation became %x\n", (int)*ptr);
419 #endif
420 }
422 /****************************************************************************/
424 static int load_flat_file(struct linux_binprm * bprm,
425 struct lib_info *libinfo, int id, unsigned long *extra_stack)
426 {
427 struct flat_hdr * hdr;
428 unsigned long textpos = 0, datapos = 0, result;
429 unsigned long realdatastart = 0;
430 unsigned long text_len, data_len, bss_len, stack_len, flags;
431 unsigned long len, memp = 0;
432 unsigned long memp_size, extra, rlim;
433 unsigned long *reloc = 0, *rp;
434 struct inode *inode;
435 int i, rev, relocs = 0;
436 loff_t fpos;
437 unsigned long start_code, end_code;
438 int ret;
440 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
441 inode = bprm->file->f_path.dentry->d_inode;
443 text_len = ntohl(hdr->data_start);
444 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
445 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
446 stack_len = ntohl(hdr->stack_size);
447 if (extra_stack) {
448 stack_len += *extra_stack;
449 *extra_stack = stack_len;
450 }
451 relocs = ntohl(hdr->reloc_count);
452 flags = ntohl(hdr->flags);
453 rev = ntohl(hdr->rev);
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 }
467 if (flags & FLAT_FLAG_KTRACE)
468 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
470 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
471 printk("BINFMT_FLAT: bad flat file version 0x%x (supported "
472 "0x%lx and 0x%lx)\n",
473 rev, FLAT_VERSION, OLD_FLAT_VERSION);
474 ret = -ENOEXEC;
475 goto err;
476 }
478 /* Don't allow old format executables to use shared libraries */
479 if (rev == OLD_FLAT_VERSION && id != 0) {
480 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
481 (int) FLAT_VERSION);
482 ret = -ENOEXEC;
483 goto err;
484 }
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 && flat_old_ram_flag(flags))
491 flags = FLAT_FLAG_RAM;
493 #ifndef CONFIG_BINFMT_ZFLAT
494 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
495 printk("Support for ZFLAT executables is not enabled.\n");
496 ret = -ENOEXEC;
497 goto err;
498 }
499 #endif
501 /*
502 * Check initial limits. This avoids letting people circumvent
503 * size limits imposed on them by creating programs with large
504 * arrays in the data or bss.
505 */
506 rlim = rlimit(RLIMIT_DATA);
507 if (rlim >= RLIM_INFINITY)
508 rlim = ~0;
509 if (data_len + bss_len > rlim) {
510 ret = -ENOMEM;
511 goto err;
512 }
514 /* Flush all traces of the currently running executable */
515 if (id == 0) {
516 result = flush_old_exec(bprm);
517 if (result) {
518 ret = result;
519 goto err;
520 }
522 /* OK, This is the point of no return */
523 set_personality(PER_LINUX_32BIT);
524 setup_new_exec(bprm);
525 }
527 /*
528 * calculate the extra space we need to map in
529 */
530 extra = max_t(unsigned long, bss_len + stack_len,
531 relocs * sizeof(unsigned long));
533 /*
534 * there are a couple of cases here, the separate code/data
535 * case, and then the fully copied to RAM case which lumps
536 * it all together.
537 */
538 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
539 /*
540 * this should give us a ROM ptr, but if it doesn't we don't
541 * really care
542 */
543 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
545 textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
546 MAP_PRIVATE|MAP_EXECUTABLE, 0);
547 if (!textpos || IS_ERR_VALUE(textpos)) {
548 if (!textpos)
549 textpos = (unsigned long) -ENOMEM;
550 printk("Unable to mmap process text, errno %d\n", (int)-textpos);
551 ret = textpos;
552 goto err;
553 }
555 len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
556 len = PAGE_ALIGN(len);
557 realdatastart = vm_mmap(0, 0, len,
558 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
560 if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
561 if (!realdatastart)
562 realdatastart = (unsigned long) -ENOMEM;
563 printk("Unable to allocate RAM for process data, errno %d\n",
564 (int)-realdatastart);
565 vm_munmap(textpos, text_len);
566 ret = realdatastart;
567 goto err;
568 }
569 datapos = ALIGN(realdatastart +
570 MAX_SHARED_LIBS * sizeof(unsigned long),
571 FLAT_DATA_ALIGN);
573 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
574 (int)(data_len + bss_len + stack_len), (int)datapos);
576 fpos = ntohl(hdr->data_start);
577 #ifdef CONFIG_BINFMT_ZFLAT
578 if (flags & FLAT_FLAG_GZDATA) {
579 result = decompress_exec(bprm, fpos, (char *) datapos,
580 data_len + (relocs * sizeof(unsigned long)), 0);
581 } else
582 #endif
583 {
584 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
585 data_len + (relocs * sizeof(unsigned long)), &fpos);
586 }
587 if (IS_ERR_VALUE(result)) {
588 printk("Unable to read data+bss, errno %d\n", (int)-result);
589 vm_munmap(textpos, text_len);
590 vm_munmap(realdatastart, len);
591 ret = result;
592 goto err;
593 }
595 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
596 memp = realdatastart;
597 memp_size = len;
598 } else {
600 len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
601 len = PAGE_ALIGN(len);
602 textpos = vm_mmap(0, 0, len,
603 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
605 if (!textpos || IS_ERR_VALUE(textpos)) {
606 if (!textpos)
607 textpos = (unsigned long) -ENOMEM;
608 printk("Unable to allocate RAM for process text/data, errno %d\n",
609 (int)-textpos);
610 ret = textpos;
611 goto err;
612 }
614 realdatastart = textpos + ntohl(hdr->data_start);
615 datapos = ALIGN(realdatastart +
616 MAX_SHARED_LIBS * sizeof(unsigned long),
617 FLAT_DATA_ALIGN);
619 reloc = (unsigned long *)
620 (datapos + (ntohl(hdr->reloc_start) - text_len));
621 memp = textpos;
622 memp_size = len;
623 #ifdef CONFIG_BINFMT_ZFLAT
624 /*
625 * load it all in and treat it like a RAM load from now on
626 */
627 if (flags & FLAT_FLAG_GZIP) {
628 result = decompress_exec(bprm, sizeof (struct flat_hdr),
629 (((char *) textpos) + sizeof (struct flat_hdr)),
630 (text_len + data_len + (relocs * sizeof(unsigned long))
631 - sizeof (struct flat_hdr)),
632 0);
633 memmove((void *) datapos, (void *) realdatastart,
634 data_len + (relocs * sizeof(unsigned long)));
635 } else if (flags & FLAT_FLAG_GZDATA) {
636 fpos = 0;
637 result = bprm->file->f_op->read(bprm->file,
638 (char *) textpos, text_len, &fpos);
639 if (!IS_ERR_VALUE(result))
640 result = decompress_exec(bprm, text_len, (char *) datapos,
641 data_len + (relocs * sizeof(unsigned long)), 0);
642 }
643 else
644 #endif
645 {
646 fpos = 0;
647 result = bprm->file->f_op->read(bprm->file,
648 (char *) textpos, text_len, &fpos);
649 if (!IS_ERR_VALUE(result)) {
650 fpos = ntohl(hdr->data_start);
651 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
652 data_len + (relocs * sizeof(unsigned long)), &fpos);
653 }
654 }
655 if (IS_ERR_VALUE(result)) {
656 printk("Unable to read code+data+bss, errno %d\n",(int)-result);
657 vm_munmap(textpos, text_len + data_len + extra +
658 MAX_SHARED_LIBS * sizeof(unsigned long));
659 ret = result;
660 goto err;
661 }
662 }
664 if (flags & FLAT_FLAG_KTRACE)
665 printk("Mapping is %x, Entry point is %x, data_start is %x\n",
666 (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
668 /* The main program needs a little extra setup in the task structure */
669 start_code = textpos + sizeof (struct flat_hdr);
670 end_code = textpos + text_len;
671 if (id == 0) {
672 current->mm->start_code = start_code;
673 current->mm->end_code = end_code;
674 current->mm->start_data = datapos;
675 current->mm->end_data = datapos + data_len;
676 /*
677 * set up the brk stuff, uses any slack left in data/bss/stack
678 * allocation. We put the brk after the bss (between the bss
679 * and stack) like other platforms.
680 * Userspace code relies on the stack pointer starting out at
681 * an address right at the end of a page.
682 */
683 current->mm->start_brk = datapos + data_len + bss_len;
684 current->mm->brk = (current->mm->start_brk + 3) & ~3;
685 current->mm->context.end_brk = memp + memp_size - stack_len;
686 }
688 if (flags & FLAT_FLAG_KTRACE)
689 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
690 id ? "Lib" : "Load", bprm->filename,
691 (int) start_code, (int) end_code,
692 (int) datapos,
693 (int) (datapos + data_len),
694 (int) (datapos + data_len),
695 (int) (((datapos + data_len + bss_len) + 3) & ~3));
697 text_len -= sizeof(struct flat_hdr); /* the real code len */
699 /* Store the current module values into the global library structure */
700 libinfo->lib_list[id].start_code = start_code;
701 libinfo->lib_list[id].start_data = datapos;
702 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
703 libinfo->lib_list[id].text_len = text_len;
704 libinfo->lib_list[id].loaded = 1;
705 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
706 libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
708 /*
709 * We just load the allocations into some temporary memory to
710 * help simplify all this mumbo jumbo
711 *
712 * We've got two different sections of relocation entries.
713 * The first is the GOT which resides at the beginning of the data segment
714 * and is terminated with a -1. This one can be relocated in place.
715 * The second is the extra relocation entries tacked after the image's
716 * data segment. These require a little more processing as the entry is
717 * really an offset into the image which contains an offset into the
718 * image.
719 */
720 if (flags & FLAT_FLAG_GOTPIC) {
721 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
722 unsigned long addr;
723 if (*rp) {
724 addr = calc_reloc(*rp, libinfo, id, 0);
725 if (addr == RELOC_FAILED) {
726 ret = -ENOEXEC;
727 goto err;
728 }
729 *rp = addr;
730 }
731 }
732 }
734 /*
735 * Now run through the relocation entries.
736 * We've got to be careful here as C++ produces relocatable zero
737 * entries in the constructor and destructor tables which are then
738 * tested for being not zero (which will always occur unless we're
739 * based from address zero). This causes an endless loop as __start
740 * is at zero. The solution used is to not relocate zero addresses.
741 * This has the negative side effect of not allowing a global data
742 * reference to be statically initialised to _stext (I've moved
743 * __start to address 4 so that is okay).
744 */
745 if (rev > OLD_FLAT_VERSION) {
746 unsigned long persistent = 0;
747 for (i=0; i < relocs; i++) {
748 unsigned long addr, relval;
750 /* Get the address of the pointer to be
751 relocated (of course, the address has to be
752 relocated first). */
753 relval = ntohl(reloc[i]);
754 if (flat_set_persistent (relval, &persistent))
755 continue;
756 addr = flat_get_relocate_addr(relval);
757 rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
758 if (rp == (unsigned long *)RELOC_FAILED) {
759 ret = -ENOEXEC;
760 goto err;
761 }
763 /* Get the pointer's value. */
764 addr = flat_get_addr_from_rp(rp, relval, flags,
765 &persistent);
766 if (addr != 0) {
767 /*
768 * Do the relocation. PIC relocs in the data section are
769 * already in target order
770 */
771 if ((flags & FLAT_FLAG_GOTPIC) == 0)
772 addr = ntohl(addr);
773 addr = calc_reloc(addr, libinfo, id, 0);
774 if (addr == RELOC_FAILED) {
775 ret = -ENOEXEC;
776 goto err;
777 }
779 /* Write back the relocated pointer. */
780 flat_put_addr_at_rp(rp, addr, relval);
781 }
782 }
783 } else {
784 for (i=0; i < relocs; i++)
785 old_reloc(ntohl(reloc[i]));
786 }
788 flush_icache_range(start_code, end_code);
790 /* zero the BSS, BRK and stack areas */
791 memset((void*)(datapos + data_len), 0, bss_len +
792 (memp + memp_size - stack_len - /* end brk */
793 libinfo->lib_list[id].start_brk) + /* start brk */
794 stack_len);
796 return 0;
797 err:
798 return ret;
799 }
802 /****************************************************************************/
803 #ifdef CONFIG_BINFMT_SHARED_FLAT
805 /*
806 * Load a shared library into memory. The library gets its own data
807 * segment (including bss) but not argv/argc/environ.
808 */
810 static int load_flat_shared_library(int id, struct lib_info *libs)
811 {
812 struct linux_binprm bprm;
813 int res;
814 char buf[16];
816 memset(&bprm, 0, sizeof(bprm));
818 /* Create the file name */
819 sprintf(buf, "/lib/lib%d.so", id);
821 /* Open the file up */
822 bprm.filename = buf;
823 bprm.file = open_exec(bprm.filename);
824 res = PTR_ERR(bprm.file);
825 if (IS_ERR(bprm.file))
826 return res;
828 bprm.cred = prepare_exec_creds();
829 res = -ENOMEM;
830 if (!bprm.cred)
831 goto out;
833 /* We don't really care about recalculating credentials at this point
834 * as we're past the point of no return and are dealing with shared
835 * libraries.
836 */
837 bprm.cred_prepared = 1;
839 res = prepare_binprm(&bprm);
841 if (!IS_ERR_VALUE(res))
842 res = load_flat_file(&bprm, libs, id, NULL);
844 abort_creds(bprm.cred);
846 out:
847 allow_write_access(bprm.file);
848 fput(bprm.file);
850 return(res);
851 }
853 #endif /* CONFIG_BINFMT_SHARED_FLAT */
854 /****************************************************************************/
856 /*
857 * These are the functions used to load flat style executables and shared
858 * libraries. There is no binary dependent code anywhere else.
859 */
861 static int load_flat_binary(struct linux_binprm * bprm)
862 {
863 struct lib_info libinfo;
864 struct pt_regs *regs = current_pt_regs();
865 unsigned long p = bprm->p;
866 unsigned long stack_len;
867 unsigned long start_addr;
868 unsigned long *sp;
869 int res;
870 int i, j;
872 memset(&libinfo, 0, sizeof(libinfo));
873 /*
874 * We have to add the size of our arguments to our stack size
875 * otherwise it's too easy for users to create stack overflows
876 * by passing in a huge argument list. And yes, we have to be
877 * pedantic and include space for the argv/envp array as it may have
878 * a lot of entries.
879 */
880 #define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
881 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */
882 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
883 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
884 stack_len += FLAT_STACK_ALIGN - 1; /* reserve for upcoming alignment */
886 res = load_flat_file(bprm, &libinfo, 0, &stack_len);
887 if (IS_ERR_VALUE(res))
888 return res;
890 /* Update data segment pointers for all libraries */
891 for (i=0; i<MAX_SHARED_LIBS; i++)
892 if (libinfo.lib_list[i].loaded)
893 for (j=0; j<MAX_SHARED_LIBS; j++)
894 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
895 (libinfo.lib_list[j].loaded)?
896 libinfo.lib_list[j].start_data:UNLOADED_LIB;
898 install_exec_creds(bprm);
900 set_binfmt(&flat_format);
902 p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
903 DBG_FLT("p=%x\n", (int)p);
905 /* copy the arg pages onto the stack, this could be more efficient :-) */
906 for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
907 * (char *) --p =
908 ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
910 sp = (unsigned long *) create_flat_tables(p, bprm);
912 /* Fake some return addresses to ensure the call chain will
913 * initialise library in order for us. We are required to call
914 * lib 1 first, then 2, ... and finally the main program (id 0).
915 */
916 start_addr = libinfo.lib_list[0].entry;
918 #ifdef CONFIG_BINFMT_SHARED_FLAT
919 for (i = MAX_SHARED_LIBS-1; i>0; i--) {
920 if (libinfo.lib_list[i].loaded) {
921 /* Push previos first to call address */
922 --sp; put_user(start_addr, sp);
923 start_addr = libinfo.lib_list[i].entry;
924 }
925 }
926 #endif
928 /* Stash our initial stack pointer into the mm structure */
929 current->mm->start_stack = (unsigned long )sp;
931 #ifdef FLAT_PLAT_INIT
932 FLAT_PLAT_INIT(regs);
933 #endif
934 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
935 (int)regs, (int)start_addr, (int)current->mm->start_stack);
937 start_thread(regs, start_addr, current->mm->start_stack);
939 return 0;
940 }
942 /****************************************************************************/
944 static int __init init_flat_binfmt(void)
945 {
946 register_binfmt(&flat_format);
947 return 0;
948 }
950 /****************************************************************************/
952 core_initcall(init_flat_binfmt);
954 /****************************************************************************/