blob: c94d52eafd1bc3c98c9ca5108228ebd762565d36 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/****************************************************************************/
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#include <linux/module.h>
19#include <linux/config.h>
20#include <linux/kernel.h>
21#include <linux/sched.h>
22#include <linux/mm.h>
23#include <linux/mman.h>
24#include <linux/a.out.h>
25#include <linux/errno.h>
26#include <linux/signal.h>
27#include <linux/string.h>
28#include <linux/fs.h>
29#include <linux/file.h>
30#include <linux/stat.h>
31#include <linux/fcntl.h>
32#include <linux/ptrace.h>
33#include <linux/user.h>
34#include <linux/slab.h>
35#include <linux/binfmts.h>
36#include <linux/personality.h>
37#include <linux/init.h>
38#include <linux/flat.h>
Luke Yang1ad3dcc2006-03-25 03:08:24 -080039#include <linux/syscalls.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
41#include <asm/byteorder.h>
42#include <asm/system.h>
43#include <asm/uaccess.h>
44#include <asm/unaligned.h>
45#include <asm/cacheflush.h>
46
47/****************************************************************************/
48
49#if 0
50#define DEBUG 1
51#endif
52
53#ifdef DEBUG
54#define DBG_FLT(a...) printk(a)
55#else
56#define DBG_FLT(a...)
57#endif
58
59#define RELOC_FAILED 0xff00ff01 /* Relocation incorrect somewhere */
60#define UNLOADED_LIB 0x7ff000ff /* Placeholder for unused library */
61
62struct lib_info {
63 struct {
64 unsigned long start_code; /* Start of text segment */
65 unsigned long start_data; /* Start of data segment */
66 unsigned long start_brk; /* End of data segment */
67 unsigned long text_len; /* Length of text segment */
68 unsigned long entry; /* Start address for this module */
69 unsigned long build_date; /* When this one was compiled */
70 short loaded; /* Has this library been loaded? */
71 } lib_list[MAX_SHARED_LIBS];
72};
73
74#ifdef CONFIG_BINFMT_SHARED_FLAT
75static int load_flat_shared_library(int id, struct lib_info *p);
76#endif
77
78static int load_flat_binary(struct linux_binprm *, struct pt_regs * regs);
79static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file);
80
Linus Torvalds1da177e2005-04-16 15:20:36 -070081static struct linux_binfmt flat_format = {
82 .module = THIS_MODULE,
83 .load_binary = load_flat_binary,
84 .core_dump = flat_core_dump,
85 .min_coredump = PAGE_SIZE
86};
87
88/****************************************************************************/
89/*
90 * Routine writes a core dump image in the current directory.
91 * Currently only a stub-function.
92 */
93
94static int flat_core_dump(long signr, struct pt_regs * regs, struct file *file)
95{
96 printk("Process %s:%d received signr %d and should have core dumped\n",
97 current->comm, current->pid, (int) signr);
98 return(1);
99}
100
101/****************************************************************************/
102/*
103 * create_flat_tables() parses the env- and arg-strings in new user
104 * memory and creates the pointer tables from them, and puts their
105 * addresses on the "stack", returning the new stack pointer value.
106 */
107
108static unsigned long create_flat_tables(
109 unsigned long pp,
110 struct linux_binprm * bprm)
111{
112 unsigned long *argv,*envp;
113 unsigned long * sp;
114 char * p = (char*)pp;
115 int argc = bprm->argc;
116 int envc = bprm->envc;
117 char dummy;
118
119 sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p);
120
121 sp -= envc+1;
122 envp = sp;
123 sp -= argc+1;
124 argv = sp;
125
126 flat_stack_align(sp);
127 if (flat_argvp_envp_on_stack()) {
128 --sp; put_user((unsigned long) envp, sp);
129 --sp; put_user((unsigned long) argv, sp);
130 }
131
132 put_user(argc,--sp);
133 current->mm->arg_start = (unsigned long) p;
134 while (argc-->0) {
135 put_user((unsigned long) p, argv++);
136 do {
137 get_user(dummy, p); p++;
138 } while (dummy);
139 }
140 put_user((unsigned long) NULL, argv);
141 current->mm->arg_end = current->mm->env_start = (unsigned long) p;
142 while (envc-->0) {
143 put_user((unsigned long)p, envp); envp++;
144 do {
145 get_user(dummy, p); p++;
146 } while (dummy);
147 }
148 put_user((unsigned long) NULL, envp);
149 current->mm->env_end = (unsigned long) p;
150 return (unsigned long)sp;
151}
152
153/****************************************************************************/
154
155#ifdef CONFIG_BINFMT_ZFLAT
156
157#include <linux/zlib.h>
158
159#define LBUFSIZE 4000
160
161/* gzip flag byte */
162#define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */
163#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */
164#define EXTRA_FIELD 0x04 /* bit 2 set: extra field present */
165#define ORIG_NAME 0x08 /* bit 3 set: original file name present */
166#define COMMENT 0x10 /* bit 4 set: file comment present */
167#define ENCRYPTED 0x20 /* bit 5 set: file is encrypted */
168#define RESERVED 0xC0 /* bit 6,7: reserved */
169
170static int decompress_exec(
171 struct linux_binprm *bprm,
172 unsigned long offset,
173 char *dst,
174 long len,
175 int fd)
176{
177 unsigned char *buf;
178 z_stream strm;
179 loff_t fpos;
180 int ret, retval;
181
182 DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);
183
184 memset(&strm, 0, sizeof(strm));
185 strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
186 if (strm.workspace == NULL) {
187 DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
188 return -ENOMEM;
189 }
190 buf = kmalloc(LBUFSIZE, GFP_KERNEL);
191 if (buf == NULL) {
192 DBG_FLT("binfmt_flat: no memory for read buffer\n");
193 retval = -ENOMEM;
194 goto out_free;
195 }
196
197 /* Read in first chunk of data and parse gzip header. */
198 fpos = offset;
199 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
200
201 strm.next_in = buf;
202 strm.avail_in = ret;
203 strm.total_in = 0;
204
205 retval = -ENOEXEC;
206
207 /* Check minimum size -- gzip header */
208 if (ret < 10) {
209 DBG_FLT("binfmt_flat: file too small?\n");
210 goto out_free_buf;
211 }
212
213 /* Check gzip magic number */
214 if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
215 DBG_FLT("binfmt_flat: unknown compression magic?\n");
216 goto out_free_buf;
217 }
218
219 /* Check gzip method */
220 if (buf[2] != 8) {
221 DBG_FLT("binfmt_flat: unknown compression method?\n");
222 goto out_free_buf;
223 }
224 /* Check gzip flags */
225 if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
226 (buf[3] & RESERVED)) {
227 DBG_FLT("binfmt_flat: unknown flags?\n");
228 goto out_free_buf;
229 }
230
231 ret = 10;
232 if (buf[3] & EXTRA_FIELD) {
233 ret += 2 + buf[10] + (buf[11] << 8);
234 if (unlikely(LBUFSIZE == ret)) {
235 DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
236 goto out_free_buf;
237 }
238 }
239 if (buf[3] & ORIG_NAME) {
240 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
241 ;
242 if (unlikely(LBUFSIZE == ret)) {
243 DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
244 goto out_free_buf;
245 }
246 }
247 if (buf[3] & COMMENT) {
248 for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
249 ;
250 if (unlikely(LBUFSIZE == ret)) {
251 DBG_FLT("binfmt_flat: buffer overflow (COMMENT)?\n");
252 goto out_free_buf;
253 }
254 }
255
256 strm.next_in += ret;
257 strm.avail_in -= ret;
258
259 strm.next_out = dst;
260 strm.avail_out = len;
261 strm.total_out = 0;
262
263 if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {
264 DBG_FLT("binfmt_flat: zlib init failed?\n");
265 goto out_free_buf;
266 }
267
268 while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
269 ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
270 if (ret <= 0)
271 break;
272 if (ret >= (unsigned long) -4096)
273 break;
274 len -= ret;
275
276 strm.next_in = buf;
277 strm.avail_in = ret;
278 strm.total_in = 0;
279 }
280
281 if (ret < 0) {
282 DBG_FLT("binfmt_flat: decompression failed (%d), %s\n",
283 ret, strm.msg);
284 goto out_zlib;
285 }
286
287 retval = 0;
288out_zlib:
289 zlib_inflateEnd(&strm);
290out_free_buf:
291 kfree(buf);
292out_free:
293 kfree(strm.workspace);
294out:
295 return retval;
296}
297
298#endif /* CONFIG_BINFMT_ZFLAT */
299
300/****************************************************************************/
301
302static unsigned long
303calc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp)
304{
305 unsigned long addr;
306 int id;
307 unsigned long start_brk;
308 unsigned long start_data;
309 unsigned long text_len;
310 unsigned long start_code;
311
312#ifdef CONFIG_BINFMT_SHARED_FLAT
313 if (r == 0)
314 id = curid; /* Relocs of 0 are always self referring */
315 else {
316 id = (r >> 24) & 0xff; /* Find ID for this reloc */
317 r &= 0x00ffffff; /* Trim ID off here */
318 }
319 if (id >= MAX_SHARED_LIBS) {
320 printk("BINFMT_FLAT: reference 0x%x to shared library %d",
321 (unsigned) r, id);
322 goto failed;
323 }
324 if (curid != id) {
325 if (internalp) {
326 printk("BINFMT_FLAT: reloc address 0x%x not in same module "
327 "(%d != %d)", (unsigned) r, curid, id);
328 goto failed;
329 } else if ( ! p->lib_list[id].loaded &&
330 load_flat_shared_library(id, p) > (unsigned long) -4096) {
331 printk("BINFMT_FLAT: failed to load library %d", id);
332 goto failed;
333 }
334 /* Check versioning information (i.e. time stamps) */
335 if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&
336 p->lib_list[curid].build_date < p->lib_list[id].build_date) {
337 printk("BINFMT_FLAT: library %d is younger than %d", id, curid);
338 goto failed;
339 }
340 }
341#else
342 id = 0;
343#endif
344
345 start_brk = p->lib_list[id].start_brk;
346 start_data = p->lib_list[id].start_data;
347 start_code = p->lib_list[id].start_code;
348 text_len = p->lib_list[id].text_len;
349
350 if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {
351 printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
352 (int) r,(int)(start_brk-start_code),(int)text_len);
353 goto failed;
354 }
355
356 if (r < text_len) /* In text segment */
357 addr = r + start_code;
358 else /* In data segment */
359 addr = r - text_len + start_data;
360
361 /* Range checked already above so doing the range tests is redundant...*/
362 return(addr);
363
364failed:
365 printk(", killing %s!\n", current->comm);
366 send_sig(SIGSEGV, current, 0);
367
368 return RELOC_FAILED;
369}
370
371/****************************************************************************/
372
373void old_reloc(unsigned long rl)
374{
375#ifdef DEBUG
376 char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
377#endif
378 flat_v2_reloc_t r;
379 unsigned long *ptr;
380
381 r.value = rl;
382#if defined(CONFIG_COLDFIRE)
383 ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
384#else
385 ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
386#endif
387
388#ifdef DEBUG
389 printk("Relocation of variable at DATASEG+%x "
390 "(address %p, currently %x) into segment %s\n",
391 r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
392#endif
393
394 switch (r.reloc.type) {
395 case OLD_FLAT_RELOC_TYPE_TEXT:
396 *ptr += current->mm->start_code;
397 break;
398 case OLD_FLAT_RELOC_TYPE_DATA:
399 *ptr += current->mm->start_data;
400 break;
401 case OLD_FLAT_RELOC_TYPE_BSS:
402 *ptr += current->mm->end_data;
403 break;
404 default:
405 printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
406 break;
407 }
408
409#ifdef DEBUG
410 printk("Relocation became %x\n", (int)*ptr);
411#endif
412}
413
414/****************************************************************************/
415
416static int load_flat_file(struct linux_binprm * bprm,
417 struct lib_info *libinfo, int id, unsigned long *extra_stack)
418{
419 struct flat_hdr * hdr;
420 unsigned long textpos = 0, datapos = 0, result;
421 unsigned long realdatastart = 0;
422 unsigned long text_len, data_len, bss_len, stack_len, flags;
423 unsigned long memp = 0; /* for finding the brk area */
424 unsigned long extra, rlim;
425 unsigned long *reloc = 0, *rp;
426 struct inode *inode;
427 int i, rev, relocs = 0;
428 loff_t fpos;
429 unsigned long start_code, end_code;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800430 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431
432 hdr = ((struct flat_hdr *) bprm->buf); /* exec-header */
433 inode = bprm->file->f_dentry->d_inode;
434
435 text_len = ntohl(hdr->data_start);
436 data_len = ntohl(hdr->data_end) - ntohl(hdr->data_start);
437 bss_len = ntohl(hdr->bss_end) - ntohl(hdr->data_end);
438 stack_len = ntohl(hdr->stack_size);
439 if (extra_stack) {
440 stack_len += *extra_stack;
441 *extra_stack = stack_len;
442 }
443 relocs = ntohl(hdr->reloc_count);
444 flags = ntohl(hdr->flags);
445 rev = ntohl(hdr->rev);
446
Greg Ungerer845884d2006-01-10 16:59:37 +1000447 if (strncmp(hdr->magic, "bFLT", 4)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448 /*
449 * because a lot of people do not manage to produce good
450 * flat binaries, we leave this printk to help them realise
451 * the problem. We only print the error if its not a script file
452 */
453 if (strncmp(hdr->magic, "#!", 2))
Greg Ungerer845884d2006-01-10 16:59:37 +1000454 printk("BINFMT_FLAT: bad header magic\n");
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800455 ret = -ENOEXEC;
456 goto err;
Greg Ungerer845884d2006-01-10 16:59:37 +1000457 }
458
459 if (flags & FLAT_FLAG_KTRACE)
460 printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);
461
462 if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
463 printk("BINFMT_FLAT: bad flat file version 0x%x (supported 0x%x and 0x%x)\n", rev, FLAT_VERSION, OLD_FLAT_VERSION);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800464 ret = -ENOEXEC;
465 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 }
467
468 /* Don't allow old format executables to use shared libraries */
469 if (rev == OLD_FLAT_VERSION && id != 0) {
470 printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
471 (int) FLAT_VERSION);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800472 ret = -ENOEXEC;
473 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 }
475
476 /*
477 * fix up the flags for the older format, there were all kinds
478 * of endian hacks, this only works for the simple cases
479 */
480 if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))
481 flags = FLAT_FLAG_RAM;
482
483#ifndef CONFIG_BINFMT_ZFLAT
484 if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
485 printk("Support for ZFLAT executables is not enabled.\n");
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800486 ret = -ENOEXEC;
487 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 }
489#endif
490
491 /*
492 * Check initial limits. This avoids letting people circumvent
493 * size limits imposed on them by creating programs with large
494 * arrays in the data or bss.
495 */
496 rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
497 if (rlim >= RLIM_INFINITY)
498 rlim = ~0;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800499 if (data_len + bss_len > rlim) {
500 ret = -ENOMEM;
501 goto err;
502 }
503
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504 /* Flush all traces of the currently running executable */
505 if (id == 0) {
506 result = flush_old_exec(bprm);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800507 if (result) {
508 ret = result;
Andrew Mortondf889122006-05-20 15:00:01 -0700509 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800510 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511
512 /* OK, This is the point of no return */
Malcolm Parsonsfcc18e82006-06-26 11:49:41 +1000513 set_personality(PER_LINUX_32BIT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 }
515
516 /*
517 * calculate the extra space we need to map in
518 */
519 extra = max(bss_len + stack_len, relocs * sizeof(unsigned long));
520
521 /*
522 * there are a couple of cases here, the separate code/data
523 * case, and then the fully copied to RAM case which lumps
524 * it all together.
525 */
526 if ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
527 /*
528 * this should give us a ROM ptr, but if it doesn't we don't
529 * really care
530 */
531 DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");
532
533 down_write(&current->mm->mmap_sem);
Greg Ungerer213b24c2005-09-02 10:42:52 +1000534 textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC, MAP_PRIVATE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 up_write(&current->mm->mmap_sem);
536 if (!textpos || textpos >= (unsigned long) -4096) {
537 if (!textpos)
538 textpos = (unsigned long) -ENOMEM;
539 printk("Unable to mmap process text, errno %d\n", (int)-textpos);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800540 ret = textpos;
Andrew Mortondf889122006-05-20 15:00:01 -0700541 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 }
543
544 down_write(&current->mm->mmap_sem);
545 realdatastart = do_mmap(0, 0, data_len + extra +
546 MAX_SHARED_LIBS * sizeof(unsigned long),
Yoshinori Sato8f5bb042005-06-06 14:46:32 -0700547 PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 up_write(&current->mm->mmap_sem);
549
550 if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
551 if (!realdatastart)
552 realdatastart = (unsigned long) -ENOMEM;
553 printk("Unable to allocate RAM for process data, errno %d\n",
554 (int)-datapos);
555 do_munmap(current->mm, textpos, text_len);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800556 ret = realdatastart;
Andrew Mortondf889122006-05-20 15:00:01 -0700557 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 }
559 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
560
561 DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
562 (int)(data_len + bss_len + stack_len), (int)datapos);
563
564 fpos = ntohl(hdr->data_start);
565#ifdef CONFIG_BINFMT_ZFLAT
566 if (flags & FLAT_FLAG_GZDATA) {
567 result = decompress_exec(bprm, fpos, (char *) datapos,
568 data_len + (relocs * sizeof(unsigned long)), 0);
569 } else
570#endif
571 {
572 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
573 data_len + (relocs * sizeof(unsigned long)), &fpos);
574 }
575 if (result >= (unsigned long)-4096) {
576 printk("Unable to read data+bss, errno %d\n", (int)-result);
577 do_munmap(current->mm, textpos, text_len);
578 do_munmap(current->mm, realdatastart, data_len + extra);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800579 ret = result;
Andrew Mortondf889122006-05-20 15:00:01 -0700580 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581 }
582
583 reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
584 memp = realdatastart;
585
586 } else {
587
588 down_write(&current->mm->mmap_sem);
589 textpos = do_mmap(0, 0, text_len + data_len + extra +
590 MAX_SHARED_LIBS * sizeof(unsigned long),
Yoshinori Sato8f5bb042005-06-06 14:46:32 -0700591 PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700592 up_write(&current->mm->mmap_sem);
593 if (!textpos || textpos >= (unsigned long) -4096) {
594 if (!textpos)
595 textpos = (unsigned long) -ENOMEM;
596 printk("Unable to allocate RAM for process text/data, errno %d\n",
597 (int)-textpos);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800598 ret = textpos;
Andrew Mortondf889122006-05-20 15:00:01 -0700599 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600 }
601
602 realdatastart = textpos + ntohl(hdr->data_start);
603 datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
604 reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
605 MAX_SHARED_LIBS * sizeof(unsigned long));
606 memp = textpos;
607
608#ifdef CONFIG_BINFMT_ZFLAT
609 /*
610 * load it all in and treat it like a RAM load from now on
611 */
612 if (flags & FLAT_FLAG_GZIP) {
613 result = decompress_exec(bprm, sizeof (struct flat_hdr),
614 (((char *) textpos) + sizeof (struct flat_hdr)),
615 (text_len + data_len + (relocs * sizeof(unsigned long))
616 - sizeof (struct flat_hdr)),
617 0);
618 memmove((void *) datapos, (void *) realdatastart,
619 data_len + (relocs * sizeof(unsigned long)));
620 } else if (flags & FLAT_FLAG_GZDATA) {
621 fpos = 0;
622 result = bprm->file->f_op->read(bprm->file,
623 (char *) textpos, text_len, &fpos);
624 if (result < (unsigned long) -4096)
625 result = decompress_exec(bprm, text_len, (char *) datapos,
626 data_len + (relocs * sizeof(unsigned long)), 0);
627 }
628 else
629#endif
630 {
631 fpos = 0;
632 result = bprm->file->f_op->read(bprm->file,
633 (char *) textpos, text_len, &fpos);
634 if (result < (unsigned long) -4096) {
635 fpos = ntohl(hdr->data_start);
636 result = bprm->file->f_op->read(bprm->file, (char *) datapos,
637 data_len + (relocs * sizeof(unsigned long)), &fpos);
638 }
639 }
640 if (result >= (unsigned long)-4096) {
641 printk("Unable to read code+data+bss, errno %d\n",(int)-result);
642 do_munmap(current->mm, textpos, text_len + data_len + extra +
643 MAX_SHARED_LIBS * sizeof(unsigned long));
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800644 ret = result;
Andrew Mortondf889122006-05-20 15:00:01 -0700645 goto err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 }
647 }
648
649 if (flags & FLAT_FLAG_KTRACE)
650 printk("Mapping is %x, Entry point is %x, data_start is %x\n",
651 (int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
652
653 /* The main program needs a little extra setup in the task structure */
654 start_code = textpos + sizeof (struct flat_hdr);
655 end_code = textpos + text_len;
656 if (id == 0) {
657 current->mm->start_code = start_code;
658 current->mm->end_code = end_code;
659 current->mm->start_data = datapos;
660 current->mm->end_data = datapos + data_len;
661 /*
662 * set up the brk stuff, uses any slack left in data/bss/stack
663 * allocation. We put the brk after the bss (between the bss
664 * and stack) like other platforms.
665 */
666 current->mm->start_brk = datapos + data_len + bss_len;
667 current->mm->brk = (current->mm->start_brk + 3) & ~3;
668 current->mm->context.end_brk = memp + ksize((void *) memp) - stack_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 }
670
671 if (flags & FLAT_FLAG_KTRACE)
672 printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
673 id ? "Lib" : "Load", bprm->filename,
674 (int) start_code, (int) end_code,
675 (int) datapos,
676 (int) (datapos + data_len),
677 (int) (datapos + data_len),
678 (int) (((datapos + data_len + bss_len) + 3) & ~3));
679
680 text_len -= sizeof(struct flat_hdr); /* the real code len */
681
682 /* Store the current module values into the global library structure */
683 libinfo->lib_list[id].start_code = start_code;
684 libinfo->lib_list[id].start_data = datapos;
685 libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
686 libinfo->lib_list[id].text_len = text_len;
687 libinfo->lib_list[id].loaded = 1;
688 libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
689 libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
690
691 /*
692 * We just load the allocations into some temporary memory to
693 * help simplify all this mumbo jumbo
694 *
695 * We've got two different sections of relocation entries.
696 * The first is the GOT which resides at the begining of the data segment
697 * and is terminated with a -1. This one can be relocated in place.
698 * The second is the extra relocation entries tacked after the image's
699 * data segment. These require a little more processing as the entry is
700 * really an offset into the image which contains an offset into the
701 * image.
702 */
703 if (flags & FLAT_FLAG_GOTPIC) {
704 for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
705 unsigned long addr;
706 if (*rp) {
707 addr = calc_reloc(*rp, libinfo, id, 0);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800708 if (addr == RELOC_FAILED) {
709 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700710 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800711 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 *rp = addr;
713 }
714 }
715 }
716
717 /*
718 * Now run through the relocation entries.
719 * We've got to be careful here as C++ produces relocatable zero
720 * entries in the constructor and destructor tables which are then
721 * tested for being not zero (which will always occur unless we're
722 * based from address zero). This causes an endless loop as __start
723 * is at zero. The solution used is to not relocate zero addresses.
724 * This has the negative side effect of not allowing a global data
725 * reference to be statically initialised to _stext (I've moved
726 * __start to address 4 so that is okay).
727 */
728 if (rev > OLD_FLAT_VERSION) {
729 for (i=0; i < relocs; i++) {
730 unsigned long addr, relval;
731
732 /* Get the address of the pointer to be
733 relocated (of course, the address has to be
734 relocated first). */
735 relval = ntohl(reloc[i]);
736 addr = flat_get_relocate_addr(relval);
737 rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800738 if (rp == (unsigned long *)RELOC_FAILED) {
739 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700740 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800741 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742
743 /* Get the pointer's value. */
744 addr = flat_get_addr_from_rp(rp, relval, flags);
745 if (addr != 0) {
746 /*
747 * Do the relocation. PIC relocs in the data section are
748 * already in target order
749 */
750 if ((flags & FLAT_FLAG_GOTPIC) == 0)
751 addr = ntohl(addr);
752 addr = calc_reloc(addr, libinfo, id, 0);
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800753 if (addr == RELOC_FAILED) {
754 ret = -ENOEXEC;
Andrew Mortondf889122006-05-20 15:00:01 -0700755 goto err;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800756 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757
758 /* Write back the relocated pointer. */
759 flat_put_addr_at_rp(rp, addr, relval);
760 }
761 }
762 } else {
763 for (i=0; i < relocs; i++)
764 old_reloc(ntohl(reloc[i]));
765 }
766
767 flush_icache_range(start_code, end_code);
768
769 /* zero the BSS, BRK and stack areas */
770 memset((void*)(datapos + data_len), 0, bss_len +
771 (memp + ksize((void *) memp) - stack_len - /* end brk */
772 libinfo->lib_list[id].start_brk) + /* start brk */
773 stack_len);
774
775 return 0;
Luke Yang1ad3dcc2006-03-25 03:08:24 -0800776err:
777 return ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700778}
779
780
781/****************************************************************************/
782#ifdef CONFIG_BINFMT_SHARED_FLAT
783
784/*
785 * Load a shared library into memory. The library gets its own data
786 * segment (including bss) but not argv/argc/environ.
787 */
788
789static int load_flat_shared_library(int id, struct lib_info *libs)
790{
791 struct linux_binprm bprm;
792 int res;
793 char buf[16];
794
795 /* Create the file name */
796 sprintf(buf, "/lib/lib%d.so", id);
797
798 /* Open the file up */
799 bprm.filename = buf;
800 bprm.file = open_exec(bprm.filename);
801 res = PTR_ERR(bprm.file);
802 if (IS_ERR(bprm.file))
803 return res;
804
805 res = prepare_binprm(&bprm);
806
807 if (res <= (unsigned long)-4096)
808 res = load_flat_file(&bprm, libs, id, NULL);
809 if (bprm.file) {
810 allow_write_access(bprm.file);
811 fput(bprm.file);
812 bprm.file = NULL;
813 }
814 return(res);
815}
816
817#endif /* CONFIG_BINFMT_SHARED_FLAT */
818/****************************************************************************/
819
820/*
821 * These are the functions used to load flat style executables and shared
822 * libraries. There is no binary dependent code anywhere else.
823 */
824
825static int load_flat_binary(struct linux_binprm * bprm, struct pt_regs * regs)
826{
827 struct lib_info libinfo;
828 unsigned long p = bprm->p;
829 unsigned long stack_len;
830 unsigned long start_addr;
831 unsigned long *sp;
832 int res;
833 int i, j;
834
835 memset(&libinfo, 0, sizeof(libinfo));
836 /*
837 * We have to add the size of our arguments to our stack size
838 * otherwise it's too easy for users to create stack overflows
839 * by passing in a huge argument list. And yes, we have to be
840 * pedantic and include space for the argv/envp array as it may have
841 * a lot of entries.
842 */
843#define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
844 stack_len = TOP_OF_ARGS - bprm->p; /* the strings */
845 stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
846 stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */
847
848
849 res = load_flat_file(bprm, &libinfo, 0, &stack_len);
850 if (res > (unsigned long)-4096)
851 return res;
852
853 /* Update data segment pointers for all libraries */
854 for (i=0; i<MAX_SHARED_LIBS; i++)
855 if (libinfo.lib_list[i].loaded)
856 for (j=0; j<MAX_SHARED_LIBS; j++)
857 (-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
858 (libinfo.lib_list[j].loaded)?
859 libinfo.lib_list[j].start_data:UNLOADED_LIB;
860
861 compute_creds(bprm);
862 current->flags &= ~PF_FORKNOEXEC;
863
864 set_binfmt(&flat_format);
865
866 p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
867 DBG_FLT("p=%x\n", (int)p);
868
869 /* copy the arg pages onto the stack, this could be more efficient :-) */
870 for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
871 * (char *) --p =
872 ((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];
873
874 sp = (unsigned long *) create_flat_tables(p, bprm);
875
876 /* Fake some return addresses to ensure the call chain will
877 * initialise library in order for us. We are required to call
878 * lib 1 first, then 2, ... and finally the main program (id 0).
879 */
880 start_addr = libinfo.lib_list[0].entry;
881
882#ifdef CONFIG_BINFMT_SHARED_FLAT
883 for (i = MAX_SHARED_LIBS-1; i>0; i--) {
884 if (libinfo.lib_list[i].loaded) {
885 /* Push previos first to call address */
886 --sp; put_user(start_addr, sp);
887 start_addr = libinfo.lib_list[i].entry;
888 }
889 }
890#endif
891
892 /* Stash our initial stack pointer into the mm structure */
893 current->mm->start_stack = (unsigned long )sp;
894
895
896 DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
897 (int)regs, (int)start_addr, (int)current->mm->start_stack);
898
899 start_thread(regs, start_addr, current->mm->start_stack);
900
901 if (current->ptrace & PT_PTRACED)
902 send_sig(SIGTRAP, current, 0);
903
904 return 0;
905}
906
907/****************************************************************************/
908
909static int __init init_flat_binfmt(void)
910{
911 return register_binfmt(&flat_format);
912}
913
914static void __exit exit_flat_binfmt(void)
915{
916 unregister_binfmt(&flat_format);
917}
918
919/****************************************************************************/
920
921core_initcall(init_flat_binfmt);
922module_exit(exit_flat_binfmt);
923
924/****************************************************************************/