diff options
author | Oleg Nesterov <oleg@redhat.com> | 2011-03-06 12:02:54 -0500 |
---|---|---|
committer | Oleg Nesterov <oleg@redhat.com> | 2011-04-09 09:53:56 -0400 |
commit | 0e028465d18b7c6797fcbdea632299d16097c5cd (patch) | |
tree | d03a1f0f688e9c4a780b2a1a3ef8354378b0ad42 /fs/compat.c | |
parent | ba2d01629d0d167598cfea85adc7926822bbfc45 (diff) |
exec: unify do_execve/compat_do_execve code
Add the appropriate members into struct user_arg_ptr and teach
get_user_arg_ptr() to handle is_compat = T case correctly.
This allows us to remove the compat_do_execve() code from fs/compat.c
and reimplement compat_do_execve() as the trivial wrapper on top of
do_execve_common(is_compat => true).
In fact, this fixes another (minor) bug. "compat_uptr_t str" can
overflow after "str += len" in compat_copy_strings() if a 64bit
application execs via sys32_execve().
Unexport acct_arg_size() and get_arg_page(), fs/compat.c doesn't
need them any longer.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Tested-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Diffstat (limited to 'fs/compat.c')
-rw-r--r-- | fs/compat.c | 235 |
1 files changed, 0 insertions, 235 deletions
diff --git a/fs/compat.c b/fs/compat.c index 72fe6cda9108..0ea00832de23 100644 --- a/fs/compat.c +++ b/fs/compat.c | |||
@@ -1306,241 +1306,6 @@ compat_sys_openat(unsigned int dfd, const char __user *filename, int flags, int | |||
1306 | return do_sys_open(dfd, filename, flags, mode); | 1306 | return do_sys_open(dfd, filename, flags, mode); |
1307 | } | 1307 | } |
1308 | 1308 | ||
1309 | /* | ||
1310 | * compat_count() counts the number of arguments/envelopes. It is basically | ||
1311 | * a copy of count() from fs/exec.c, except that it works with 32 bit argv | ||
1312 | * and envp pointers. | ||
1313 | */ | ||
1314 | static int compat_count(compat_uptr_t __user *argv, int max) | ||
1315 | { | ||
1316 | int i = 0; | ||
1317 | |||
1318 | if (argv != NULL) { | ||
1319 | for (;;) { | ||
1320 | compat_uptr_t p; | ||
1321 | |||
1322 | if (get_user(p, argv)) | ||
1323 | return -EFAULT; | ||
1324 | if (!p) | ||
1325 | break; | ||
1326 | argv++; | ||
1327 | if (i++ >= max) | ||
1328 | return -E2BIG; | ||
1329 | |||
1330 | if (fatal_signal_pending(current)) | ||
1331 | return -ERESTARTNOHAND; | ||
1332 | cond_resched(); | ||
1333 | } | ||
1334 | } | ||
1335 | return i; | ||
1336 | } | ||
1337 | |||
1338 | /* | ||
1339 | * compat_copy_strings() is basically a copy of copy_strings() from fs/exec.c | ||
1340 | * except that it works with 32 bit argv and envp pointers. | ||
1341 | */ | ||
1342 | static int compat_copy_strings(int argc, compat_uptr_t __user *argv, | ||
1343 | struct linux_binprm *bprm) | ||
1344 | { | ||
1345 | struct page *kmapped_page = NULL; | ||
1346 | char *kaddr = NULL; | ||
1347 | unsigned long kpos = 0; | ||
1348 | int ret; | ||
1349 | |||
1350 | while (argc-- > 0) { | ||
1351 | compat_uptr_t str; | ||
1352 | int len; | ||
1353 | unsigned long pos; | ||
1354 | |||
1355 | if (get_user(str, argv+argc) || | ||
1356 | !(len = strnlen_user(compat_ptr(str), MAX_ARG_STRLEN))) { | ||
1357 | ret = -EFAULT; | ||
1358 | goto out; | ||
1359 | } | ||
1360 | |||
1361 | if (len > MAX_ARG_STRLEN) { | ||
1362 | ret = -E2BIG; | ||
1363 | goto out; | ||
1364 | } | ||
1365 | |||
1366 | /* We're going to work our way backwords. */ | ||
1367 | pos = bprm->p; | ||
1368 | str += len; | ||
1369 | bprm->p -= len; | ||
1370 | |||
1371 | while (len > 0) { | ||
1372 | int offset, bytes_to_copy; | ||
1373 | |||
1374 | if (fatal_signal_pending(current)) { | ||
1375 | ret = -ERESTARTNOHAND; | ||
1376 | goto out; | ||
1377 | } | ||
1378 | cond_resched(); | ||
1379 | |||
1380 | offset = pos % PAGE_SIZE; | ||
1381 | if (offset == 0) | ||
1382 | offset = PAGE_SIZE; | ||
1383 | |||
1384 | bytes_to_copy = offset; | ||
1385 | if (bytes_to_copy > len) | ||
1386 | bytes_to_copy = len; | ||
1387 | |||
1388 | offset -= bytes_to_copy; | ||
1389 | pos -= bytes_to_copy; | ||
1390 | str -= bytes_to_copy; | ||
1391 | len -= bytes_to_copy; | ||
1392 | |||
1393 | if (!kmapped_page || kpos != (pos & PAGE_MASK)) { | ||
1394 | struct page *page; | ||
1395 | |||
1396 | page = get_arg_page(bprm, pos, 1); | ||
1397 | if (!page) { | ||
1398 | ret = -E2BIG; | ||
1399 | goto out; | ||
1400 | } | ||
1401 | |||
1402 | if (kmapped_page) { | ||
1403 | flush_kernel_dcache_page(kmapped_page); | ||
1404 | kunmap(kmapped_page); | ||
1405 | put_page(kmapped_page); | ||
1406 | } | ||
1407 | kmapped_page = page; | ||
1408 | kaddr = kmap(kmapped_page); | ||
1409 | kpos = pos & PAGE_MASK; | ||
1410 | flush_cache_page(bprm->vma, kpos, | ||
1411 | page_to_pfn(kmapped_page)); | ||
1412 | } | ||
1413 | if (copy_from_user(kaddr+offset, compat_ptr(str), | ||
1414 | bytes_to_copy)) { | ||
1415 | ret = -EFAULT; | ||
1416 | goto out; | ||
1417 | } | ||
1418 | } | ||
1419 | } | ||
1420 | ret = 0; | ||
1421 | out: | ||
1422 | if (kmapped_page) { | ||
1423 | flush_kernel_dcache_page(kmapped_page); | ||
1424 | kunmap(kmapped_page); | ||
1425 | put_page(kmapped_page); | ||
1426 | } | ||
1427 | return ret; | ||
1428 | } | ||
1429 | |||
1430 | /* | ||
1431 | * compat_do_execve() is mostly a copy of do_execve(), with the exception | ||
1432 | * that it processes 32 bit argv and envp pointers. | ||
1433 | */ | ||
1434 | int compat_do_execve(char * filename, | ||
1435 | compat_uptr_t __user *argv, | ||
1436 | compat_uptr_t __user *envp, | ||
1437 | struct pt_regs * regs) | ||
1438 | { | ||
1439 | struct linux_binprm *bprm; | ||
1440 | struct file *file; | ||
1441 | struct files_struct *displaced; | ||
1442 | bool clear_in_exec; | ||
1443 | int retval; | ||
1444 | |||
1445 | retval = unshare_files(&displaced); | ||
1446 | if (retval) | ||
1447 | goto out_ret; | ||
1448 | |||
1449 | retval = -ENOMEM; | ||
1450 | bprm = kzalloc(sizeof(*bprm), GFP_KERNEL); | ||
1451 | if (!bprm) | ||
1452 | goto out_files; | ||
1453 | |||
1454 | retval = prepare_bprm_creds(bprm); | ||
1455 | if (retval) | ||
1456 | goto out_free; | ||
1457 | |||
1458 | retval = check_unsafe_exec(bprm); | ||
1459 | if (retval < 0) | ||
1460 | goto out_free; | ||
1461 | clear_in_exec = retval; | ||
1462 | current->in_execve = 1; | ||
1463 | |||
1464 | file = open_exec(filename); | ||
1465 | retval = PTR_ERR(file); | ||
1466 | if (IS_ERR(file)) | ||
1467 | goto out_unmark; | ||
1468 | |||
1469 | sched_exec(); | ||
1470 | |||
1471 | bprm->file = file; | ||
1472 | bprm->filename = filename; | ||
1473 | bprm->interp = filename; | ||
1474 | |||
1475 | retval = bprm_mm_init(bprm); | ||
1476 | if (retval) | ||
1477 | goto out_file; | ||
1478 | |||
1479 | bprm->argc = compat_count(argv, MAX_ARG_STRINGS); | ||
1480 | if ((retval = bprm->argc) < 0) | ||
1481 | goto out; | ||
1482 | |||
1483 | bprm->envc = compat_count(envp, MAX_ARG_STRINGS); | ||
1484 | if ((retval = bprm->envc) < 0) | ||
1485 | goto out; | ||
1486 | |||
1487 | retval = prepare_binprm(bprm); | ||
1488 | if (retval < 0) | ||
1489 | goto out; | ||
1490 | |||
1491 | retval = copy_strings_kernel(1, &bprm->filename, bprm); | ||
1492 | if (retval < 0) | ||
1493 | goto out; | ||
1494 | |||
1495 | bprm->exec = bprm->p; | ||
1496 | retval = compat_copy_strings(bprm->envc, envp, bprm); | ||
1497 | if (retval < 0) | ||
1498 | goto out; | ||
1499 | |||
1500 | retval = compat_copy_strings(bprm->argc, argv, bprm); | ||
1501 | if (retval < 0) | ||
1502 | goto out; | ||
1503 | |||
1504 | retval = search_binary_handler(bprm, regs); | ||
1505 | if (retval < 0) | ||
1506 | goto out; | ||
1507 | |||
1508 | /* execve succeeded */ | ||
1509 | current->fs->in_exec = 0; | ||
1510 | current->in_execve = 0; | ||
1511 | acct_update_integrals(current); | ||
1512 | free_bprm(bprm); | ||
1513 | if (displaced) | ||
1514 | put_files_struct(displaced); | ||
1515 | return retval; | ||
1516 | |||
1517 | out: | ||
1518 | if (bprm->mm) { | ||
1519 | acct_arg_size(bprm, 0); | ||
1520 | mmput(bprm->mm); | ||
1521 | } | ||
1522 | |||
1523 | out_file: | ||
1524 | if (bprm->file) { | ||
1525 | allow_write_access(bprm->file); | ||
1526 | fput(bprm->file); | ||
1527 | } | ||
1528 | |||
1529 | out_unmark: | ||
1530 | if (clear_in_exec) | ||
1531 | current->fs->in_exec = 0; | ||
1532 | current->in_execve = 0; | ||
1533 | |||
1534 | out_free: | ||
1535 | free_bprm(bprm); | ||
1536 | |||
1537 | out_files: | ||
1538 | if (displaced) | ||
1539 | reset_files_struct(displaced); | ||
1540 | out_ret: | ||
1541 | return retval; | ||
1542 | } | ||
1543 | |||
1544 | #define __COMPAT_NFDBITS (8 * sizeof(compat_ulong_t)) | 1309 | #define __COMPAT_NFDBITS (8 * sizeof(compat_ulong_t)) |
1545 | 1310 | ||
1546 | static int poll_select_copy_remaining(struct timespec *end_time, void __user *p, | 1311 | static int poll_select_copy_remaining(struct timespec *end_time, void __user *p, |