aboutsummaryrefslogtreecommitdiffstats
path: root/fs/compat.c
blob: 302e761bd0aa643712c4626424d4d708919017e0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
/*
 *  linux/fs/compat.c
 *
 *  Kernel compatibililty routines for e.g. 32 bit syscall support
 *  on 64 bit kernels.
 *
 *  Copyright (C) 2002       Stephen Rothwell, IBM Corporation
 *  Copyright (C) 1997-2000  Jakub Jelinek  (jakub@redhat.com)
 *  Copyright (C) 1998       Eddie C. Dost  (ecd@skynet.be)
 *  Copyright (C) 2001,2002  Andi Kleen, SuSE Labs 
 *  Copyright (C) 2003       Pavel Machek (pavel@ucw.cz)
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/linkage.h>
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/fs.h>
#include <linux/fcntl.h>
#include <linux/namei.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/vfs.h>
#include <linux/ioctl.h>
#include <linux/init.h>
#include <linux/ncp_mount.h>
#include <linux/nfs4_mount.h>
#include <linux/syscalls.h>
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/dirent.h>
#include <linux/fsnotify.h>
#include <linux/highuid.h>
#include <linux/personality.h>
#include <linux/rwsem.h>
#include <linux/tsacct_kern.h>
#include <linux/security.h>
#include <linux/highmem.h>
#include <linux/signal.h>
#include <linux/poll.h>
#include <linux/mm.h>
#include <linux/eventpoll.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>
#include <linux/pagemap.h>

#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/ioctls.h>
#include "internal.h"

int compat_log = 1;

int compat_printk(const char *fmt, ...)
{
	va_list ap;
	int ret;
	if (!compat_log)
		return 0;
	va_start(ap, fmt);
	ret = vprintk(fmt, ap);
	va_end(ap);
	return ret;
}

#include "read_write.h"

/*
 * Not all architectures have sys_utime, so implement this in terms
 * of sys_utimes.
 */
asmlinkage long compat_sys_utime(const char __user *filename,
				 struct compat_utimbuf __user *t)
{
	struct timespec tv[2];

	if (t) {
		if (get_user(tv[0].tv_sec, &t->actime) ||
		    get_user(tv[1].tv_sec, &t->modtime))
			return -EFAULT;
		tv[0].tv_nsec = 0;
		tv[1].tv_nsec = 0;
	}
	return do_utimes(AT_FDCWD, filename, t ? tv : NULL, 0);
}

asmlinkage long compat_sys_utimensat(unsigned int dfd, const char __user *filename, struct compat_timespec __user *t, int flags)
{
	struct timespec tv[2];

	if  (t) {
		if (get_compat_timespec(&tv[0], &t[0]) ||
		    get_compat_timespec(&tv[1], &t[1]))
			return -EFAULT;

		if (tv[0].tv_nsec == UTIME_OMIT && tv[1].tv_nsec == UTIME_OMIT)
			return 0;
	}
	return do_utimes(dfd, filename, t ? tv : NULL, flags);
}

asmlinkage long compat_sys_futimesat(unsigned int dfd, const char __user *filename, struct compat_timeval __user *t)
{
	struct timespec tv[2];

	if (t) {
		if (get_user(tv[0].tv_sec, &t[0].tv_sec) ||
		    get_user(tv[0].tv_nsec, &t[0].tv_usec) ||
		    get_user(tv[1].tv_sec, &t[1].tv_sec) ||
		    get_user(tv[1].tv_nsec, &t[1].tv_usec))
			return -EFAULT;
		if (tv[0].tv_nsec >= 1000000 || tv[0].tv_nsec < 0 ||
		    tv[1].tv_nsec >= 1000000 || tv[1].tv_nsec < 0)
			return -EINVAL;
		tv[0].tv_nsec *= 1000;
		tv[1].tv_nsec *= 1000;
	}
	return do_utimes(dfd, filename, t ? tv : NULL, 0);
}

asmlinkage long compat_sys_utimes(const char __user *filename, struct compat_timeval __user *t)
{
	return compat_sys_futimesat(AT_FDCWD, filename, t);
}

static int cp_compat_stat(struct kstat *stat, struct compat_stat __user *ubuf)
{
	compat_ino_t ino = stat->ino;
	typeof(ubuf->st_uid) uid = 0;
	typeof(ubuf->st_gid) gid = 0;
	int err;

	SET_UID(uid, stat->uid);
	SET_GID(gid, stat->gid);

	if ((u64) stat->size > MAX_NON_LFS ||
	    !old_valid_dev(stat->dev) ||
	    !old_valid_dev(stat->rdev))
		return -EOVERFLOW;
	if (sizeof(ino) < sizeof(stat->ino) && ino != stat->ino)
		return -EOVERFLOW;

	if (clear_user(ubuf, sizeof(*ubuf)))
		return -EFAULT;

	err  = __put_user(old_encode_dev(stat->dev), &ubuf->st_dev);
	err |= __put_user(ino, &ubuf->st_ino);
	err |= __put_user(stat->mode, &ubuf->st_mode);
	err |= __put_user(stat->nlink, &ubuf->st_nlink);
	err |= __put_user(uid, &ubuf->st_uid);
	err |= __put_user(gid, &ubuf->st_gid);
	err |= __put_user(old_encode_dev(stat->rdev), &ubuf->st_rdev);
	err |= __put_user(stat->size, &ubuf->st_size);
	err |= __put_user(stat->atime.tv_sec, &ubuf->st_atime);
	err |= __put_user(stat->atime.tv_nsec, &ubuf->st_atime_nsec);
	err |= __put_user(stat->mtime.tv_sec, &ubuf->st_mtime);
	err |= __put_user(stat->mtime.tv_nsec, &ubuf->st_mtime_nsec);
	err |= __put_user(stat->ctime.tv_sec, &ubuf->st_ctime);
	err |= __put_user(stat->ctime.tv_nsec, &ubuf->st_ctime_nsec);
	err |= __put_user(stat->blksize, &ubuf->st_blksize);
	err |= __put_user(stat->blocks, &ubuf->st_blocks);
	return err;
}

asmlinkage long compat_sys_newstat(const char __user * filename,
		struct compat_stat __user *statbuf)
{
	struct kstat stat;
	int error;

	error = vfs_stat(filename, &stat);
	if (error)
		return error;
	return cp_compat_stat(&stat, statbuf);
}

asmlinkage long compat_sys_newlstat(const char __user * filename,
		struct compat_stat __user *statbuf)
{
	struct kstat stat;
	int error;

	error = vfs_lstat(filename, &stat);
	if (error)
		return error;
	return cp_compat_stat(&stat, statbuf);
}

#ifndef __ARCH_WANT_STAT64
asmlinkage long compat_sys_newfstatat(unsigned int dfd,
		const char __user *filename,
		struct compat_stat __user *statbuf, int flag)
{
	struct kstat stat;
	int error;

	error = vfs_fstatat(dfd, filename, &stat, flag);
	if (error)
		return error;
	return cp_compat_stat(&stat, statbuf);
}
#endif

asmlinkage long compat_sys_newfstat(unsigned int fd,
		struct compat_stat __user * statbuf)
{
	struct kstat stat;
	int error = vfs_fstat(fd, &stat);

	if (!error)
		error = cp_compat_stat(&stat, statbuf);
	return error;
}

static int put_compat_statfs(struct compat_statfs __user *ubuf, struct kstatfs *kbuf)
{
	
	if (sizeof ubuf->f_blocks == 4) {
		if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail |
		     kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL)
			return -EOVERFLOW;
		/* f_files and f_ffree may be -1; it's okay
		 * to stuff that into 32 bits */
		if (kbuf->f_files != 0xffffffffffffffffULL
		 && (kbuf->f_files & 0xffffffff00000000ULL))
			return -EOVERFLOW;
		if (kbuf->f_ffree != 0xffffffffffffffffULL
		 && (kbuf->f_ffree & 0xffffffff00000000ULL))
			return -EOVERFLOW;
	}
	if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf)) ||
	    __put_user(kbuf->f_type, &ubuf->f_type) ||
	    __put_user(kbuf->f_bsize, &ubuf->f_bsize) ||
	    __put_user(kbuf->f_blocks, &ubuf->f_blocks) ||
	    __put_user(kbuf->f_bfree, &ubuf->f_bfree) ||
	    __put_user(kbuf->f_bavail, &ubuf->f_bavail) ||
	    __put_user(kbuf->f_files, &ubuf->f_files) ||
	    __put_user(kbuf->f_ffree, &ubuf->f_ffree) ||
	    __put_user(kbuf->f_namelen, &ubuf->f_namelen) ||
	    __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]) ||
	    __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]) ||
	    __put_user(kbuf->f_frsize, &ubuf->f_frsize) ||
	    __put_user(kbuf->f_flags, &ubuf->f_flags) ||
	    __clear_user(ubuf->f_spare, sizeof(ubuf->f_spare)))
		return -EFAULT;
	return 0;
}

/*
 * The following statfs calls are copies of code from fs/statfs.c and
 * should be checked against those from time to time
 */
asmlinkage long compat_sys_statfs(const char __user *pathname, struct compat_statfs __user *buf)
{
	struct kstatfs tmp;
	int error = user_statfs(pathname, &tmp);
	if (!error)
		error = put_compat_statfs(buf, &tmp);
	return error;
}

asmlinkage long compat_sys_fstatfs(unsigned int fd, struct compat_statfs __user *buf)
{
	struct kstatfs tmp;
	int error = fd_statfs(fd, &tmp);
	if (!error)
		error = put_compat_statfs(buf, &tmp);
	return error;
}

static int put_compat_statfs64(struct compat_statfs64 __user *ubuf, struct kstatfs *kbuf)
{
	if (sizeof ubuf->f_blocks == 4) {
		if ((kbuf->f_blocks | kbuf->f_bfree | kbuf->f_bavail |
		     kbuf->f_bsize | kbuf->f_frsize) & 0xffffffff00000000ULL)
			return -EOVERFLOW;
		/* f_files and f_ffree may be -1; it's okay
		 * to stuff that into 32 bits */
		if (kbuf->f_files != 0xffffffffffffffffULL
		 && (kbuf->f_files & 0xffffffff00000000ULL))
			return -EOVERFLOW;
		if (kbuf->f_ffree != 0xffffffffffffffffULL
		 && (kbuf->f_ffree & 0xffffffff00000000ULL))
			return -EOVERFLOW;
	}
	if (!access_ok(VERIFY_WRITE, ubuf, sizeof(*ubuf)) ||
	    __put_user(kbuf->f_type, &ubuf->f_type) ||
	    __put_user(kbuf->f_bsize, &ubuf->f_bsize) ||
	    __put_user(kbuf->f_blocks, &ubuf->f_blocks) ||
	    __put_user(kbuf->f_bfree, &ubuf->f_bfree) ||
	    __put_user(kbuf->f_bavail, &ubuf->f_bavail) ||
	    __put_user(kbuf->f_files, &ubuf->f_files) ||
	    __put_user(kbuf->f_ffree, &ubuf->f_ffree) ||
	    __put_user(kbuf->f_namelen, &ubuf->f_namelen) ||
	    __put_user(kbuf->f_fsid.val[0], &ubuf->f_fsid.val[0]) ||
	    __put_user(kbuf->f_fsid.val[1], &ubuf->f_fsid.val[1]) ||
	    __put_user(kbuf->f_frsize, &ubuf->f_frsize) ||
	    __put_user(kbuf->f_flags, &ubuf->f_flags) ||
	    __clear_user(ubuf->f_spare, sizeof(ubuf->f_spare)))
		return -EFAULT;
	return 0;
}

asmlinkage long compat_sys_statfs64(const char __user *pathname, compat_size_t sz, struct compat_statfs64 __user *buf)
{
	struct kstatfs tmp;
	int error;

	if (sz != sizeof(*buf))
		return -EINVAL;

	error = user_statfs(pathname, &tmp);
	if (!error)
		error = put_compat_statfs64(buf, &tmp);
	return error;
}

asmlinkage long compat_sys_fstatfs64(unsigned int fd, compat_size_t sz, struct compat_statfs64 __user *buf)
{
	struct kstatfs tmp;
	int error;

	if (sz != sizeof(*buf))
		return -EINVAL;

	error = fd_statfs(fd, &tmp);
	if (!error)
		error = put_compat_statfs64(buf, &tmp);
	return error;
}

/*
 * This is a copy of sys_ustat, just dealing with a structure layout.
 * Given how simple this syscall is that apporach is more maintainable
 * than the various conversion hacks.
 */
asmlinkage long compat_sys_ustat(unsigned dev, struct compat_ustat __user *u)
{
	struct super_block *sb;
	struct compat_ustat tmp;
	struct kstatfs sbuf;
	int err;

	sb = user_get_super(new_decode_dev(dev));
	if (!sb)
		return -EINVAL;
	err = statfs_by_dentry(sb->s_root, &sbuf);
	drop_super(sb);
	if (err)
		return err;

	memset(&tmp, 0, sizeof(struct compat_ustat));
	tmp.f_tfree = sbuf.f_bfree;
	tmp.f_tinode = sbuf.f_ffree;
	if (copy_to_user(u, &tmp, sizeof(struct compat_ustat)))
		return -EFAULT;
	return 0;
}

static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
	if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
	    __get_user(kfl->l_type, &ufl->l_type) ||
	    __get_user(kfl->l_whence, &ufl->l_whence) ||
	    __get_user(kfl->l_start, &ufl->l_start) ||
	    __get_user(kfl->l_len, &ufl->l_len) ||
	    __get_user(kfl->l_pid, &ufl->l_pid))
		return -EFAULT;
	return 0;
}

static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
{
	if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
	    __put_user(kfl->l_type, &ufl->l_type) ||
	    __put_user(kfl->l_whence, &ufl->l_whence) ||
	    __put_user(kfl->l_start, &ufl->l_start) ||
	    __put_user(kfl->l_len, &ufl->l_len) ||
	    __put_user(kfl->l_pid, &ufl->l_pid))
		return -EFAULT;
	return 0;
}

#ifndef HAVE_ARCH_GET_COMPAT_FLOCK64
static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
	if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
	    __get_user(kfl->l_type, &ufl->l_type) ||
	    __get_user(kfl->l_whence, &ufl->l_whence) ||
	    __get_user(kfl->l_start, &ufl->l_start) ||
	    __get_user(kfl->l_len, &ufl->l_len) ||
	    __get_user(kfl->l_pid, &ufl->l_pid))
		return -EFAULT;
	return 0;
}
#endif

#ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64
static int put_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
{
	if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
	    __put_user(kfl->l_type, &ufl->l_type) ||
	    __put_user(kfl->l_whence, &ufl->l_whence) ||
	    __put_user(kfl->l_start, &ufl->l_start) ||
	    __put_user(kfl->l_len, &ufl->l_len) ||
	    __put_user(kfl->l_pid, &ufl->l_pid))
		return -EFAULT;
	return 0;
}
#endif

asmlinkage long compat_sys_fcntl64(unsigned int fd, unsigned int cmd,
		unsigned long arg)
{
	mm_segment_t old_fs;
	struct flock f;
	long ret;

	switch (cmd) {
	case F_GETLK:
	case F_SETLK:
	case F_SETLKW:
		ret = get_compat_flock(&f, compat_ptr(arg));
		if (ret != 0)
			break;
		old_fs = get_fs();
		set_fs(KERNEL_DS);
		ret = sys_fcntl(fd, cmd, (unsigned long)&f);
		set_fs(old_fs);
		if (cmd == F_GETLK && ret == 0) {
			/* GETLK was successful and we need to return the data...
			 * but it needs to fit in the compat structure.
			 * l_start shouldn't be too big, unless the original
			 * start + end is greater than COMPAT_OFF_T_MAX, in which
			 * case the app was asking for trouble, so we return
			 * -EOVERFLOW in that case.
			 * l_len could be too big, in which case we just truncate it,
			 * and only allow the app to see that part of the conflicting
			 * lock that might make sense to it anyway
			 */

			if (f.l_start > COMPAT_OFF_T_MAX)
				ret = -EOVERFLOW;
			if (f.l_len > COMPAT_OFF_T_MAX)
				f.l_len = COMPAT_OFF_T_MAX;
			if (ret == 0)
				ret = put_compat_flock(&f, compat_ptr(arg));
		}
		break;

	case F_GETLK64:
	case F_SETLK64:
	case F_SETLKW64:
		ret = get_compat_flock64(&f, compat_ptr(arg));
		if (ret != 0)
			break;
		old_fs = get_fs();
		set_fs(KERNEL_DS);
		ret = sys_fcntl(fd, (cmd == F_GETLK64) ? F_GETLK :
				((cmd == F_SETLK64) ? F_SETLK : F_SETLKW),
				(unsigned long)&f);
		set_fs(old_fs);
		if (cmd == F_GETLK64 && ret == 0) {
			/* need to return lock information - see above for commentary */
			if (f.l_start > COMPAT_LOFF_T_MAX)
				ret = -EOVERFLOW;
			if (f.l_len > COMPAT_LOFF_T_MAX)
				f.l_len = COMPAT_LOFF_T_MAX;
			if (ret == 0)
				ret = put_compat_flock64(&f, compat_ptr(arg));
		}
		break;

	default:
		ret = sys_fcntl(fd, cmd, arg);
		break;
	}
	return ret;
}

asmlinkage long compat_sys_fcntl(unsigned int fd, unsigned int cmd,
		unsigned long arg)
{
	if ((cmd == F_GETLK64) || (cmd == F_SETLK64) || (cmd == F_SETLKW64))
		return -EINVAL;
	return compat_sys_fcntl64(fd, cmd, arg);
}

asmlinkage long
compat_sys_io_setup(unsigned nr_reqs, u32 __user *ctx32p)
{
	long ret;
	aio_context_t ctx64;

	mm_segment_t oldfs = get_fs();
	if (unlikely(get_user(ctx64, ctx32p)))
		return -EFAULT;

	set_fs(KERNEL_DS);
	/* The __user pointer cast is valid because of the set_fs() */
	ret = sys_io_setup(nr_reqs, (aio_context_t __user *) &ctx64);
	set_fs(oldfs);
	/* truncating is ok because it's a user address */
	if (!ret)
		ret = put_user((u32) ctx64, ctx32p);
	return ret;
}

asmlinkage long
compat_sys_io_getevents(aio_context_t ctx_id,
				 unsigned long min_nr,
				 unsigned long nr,
				 struct io_event __user *events,
				 struct compat_timespec __user *timeout)
{
	long ret;
	struct timespec t;
	struct timespec __user *ut = NULL;

	ret = -EFAULT;
	if (unlikely(!access_ok(VERIFY_WRITE, events, 
				nr * sizeof(struct io_event))))
		goto out;
	if (timeout) {
		if (get_compat_timespec(&t, timeout))
			goto out;

		ut = compat_alloc_user_space(sizeof(*ut));
		if (copy_to_user(ut, &t, sizeof(t)) )
			goto out;
	} 
	ret = sys_io_getevents(ctx_id, min_nr, nr, events, ut);
out:
	return ret;
}

/* A write operation does a read from user space and vice versa */
#define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)

ssize_t compat_rw_copy_check_uvector(int type,
		const struct compat_iovec __user *uvector, unsigned long nr_segs,
		unsigned long fast_segs, struct iovec *fast_pointer,
		struct iovec **ret_pointer)
{
	compat_ssize_t tot_len;
	struct iovec *iov = *ret_pointer = fast_pointer;
	ssize_t ret = 0;
	int seg;

	/*
	 * SuS says "The readv() function *may* fail if the iovcnt argument
	 * was less than or equal to 0, or greater than {IOV_MAX}.  Linux has
	 * traditionally returned zero for zero segments, so...
	 */
	if (nr_segs == 0)
		goto out;

	ret = -EINVAL;
	if (nr_segs > UIO_MAXIOV || nr_segs < 0)
		goto out;
	if (nr_segs > fast_segs) {
		ret = -ENOMEM;
		iov = kmalloc(nr_segs*sizeof(struct iovec), GFP_KERNEL);
		if (iov == NULL)
			goto out;
	}
	*ret_pointer = iov;

	/*
	 * Single unix specification:
	 * We should -EINVAL if an element length is not >= 0 and fitting an
	 * ssize_t.
	 *
	 * In Linux, the total length is limited to MAX_RW_COUNT, there is
	 * no overflow possibility.
	 */
	tot_len = 0;
	ret = -EINVAL;
	for (seg = 0; seg < nr_segs; seg++) {
		compat_uptr_t buf;
		compat_ssize_t len;

		if (__get_user(len, &uvector->iov_len) ||
		   __get_user(buf, &uvector->iov_base)) {
			ret = -EFAULT;
			goto out;
		}
		if (len < 0)	/* size_t not fitting in compat_ssize_t .. */
			goto out;
		if (!access_ok(vrfy_dir(type), compat_ptr(buf), len)) {
			ret = -EFAULT;
			goto out;
		}
		if (len > MAX_RW_COUNT - tot_len)
			len = MAX_RW_COUNT - tot_len;
		tot_len += len;
		iov->iov_base = compat_ptr(buf);
		iov->iov_len = (compat_size_t) len;
		uvector++;
		iov++;
	}
	ret = tot_len;

out:
	return ret;
}

static inline long
copy_iocb(long nr, u32 __user *ptr32, struct iocb __user * __user *ptr64)
{
	compat_uptr_t uptr;
	int i;

	for (i = 0; i < nr; ++i) {
		if (get_user(uptr, ptr32 + i))
			return -EFAULT;
		if (put_user(compat_ptr(uptr), ptr64 + i))
			return -EFAULT;
	}
	return 0;
}

#define MAX_AIO_SUBMITS 	(PAGE_SIZE/sizeof(struct iocb *))

asmlinkage long
compat_sys_io_submit(aio_context_t ctx_id, int nr, u32 __user *iocb)
{
	struct iocb __user * __user *iocb64; 
	long ret;

	if (unlikely(nr < 0))
		return -EINVAL;

	if (nr > MAX_AIO_SUBMITS)
		nr = MAX_AIO_SUBMITS;
	
	iocb64 = compat_alloc_user_space(nr * sizeof(*iocb64));
	ret = copy_iocb(nr, iocb, iocb64);
	if (!ret)
		ret = do_io_submit(ctx_id, nr, iocb64, 1);
	return ret;
}

struct compat_ncp_mount_data {
	compat_int_t version;
	compat_uint_t ncp_fd;
	__compat_uid_t mounted_uid;
	compat_pid_t wdog_pid;
	unsigned char mounted_vol[NCP_VOLNAME_LEN + 1];
	compat_uint_t time_out;
	compat_uint_t retry_count;
	compat_uint_t flags;
	__compat_uid_t uid;
	__compat_gid_t gid;
	compat_mode_t file_mode;
	compat_mode_t dir_mode;
};

struct compat_ncp_mount_data_v4 {
	compat_int_t version;
	compat_ulong_t flags;
	compat_ulong_t mounted_uid;
	compat_long_t wdog_pid;
	compat_uint_t ncp_fd;
	compat_uint_t time_out;
	compat_uint_t retry_count;
	compat_ulong_t uid;
	compat_ulong_t gid;
	compat_ulong_t file_mode;
	compat_ulong_t dir_mode;
};

static void *do_ncp_super_data_conv(void *raw_data)
{
	int version = *(unsigned int *)raw_data;

	if (version == 3) {
		struct compat_ncp_mount_data *c_n = raw_data;
		struct ncp_mount_data *n = raw_data;

		n->dir_mode = c_n->dir_mode;
		n->file_mode = c_n->file_mode;
		n->gid = c_n->gid;
		n->uid = c_n->uid;
		memmove (n->mounted_vol, c_n->mounted_vol, (sizeof (c_n->mounted_vol) + 3 * sizeof (unsigned int)));
		n->wdog_pid = c_n->wdog_pid;
		n->mounted_uid = c_n->mounted_uid;
	} else if (version == 4) {
		struct compat_ncp_mount_data_v4 *c_n = raw_data;
		struct ncp_mount_data_v4 *n = raw_data;

		n->dir_mode = c_n->dir_mode;
		n->file_mode = c_n->file_mode;
		n->gid = c_n->gid;
		n->uid = c_n->uid;
		n->retry_count = c_n->retry_count;
		n->time_out = c_n->time_out;
		n->ncp_fd = c_n->ncp_fd;
		n->wdog_pid = c_n->wdog_pid;
		n->mounted_uid = c_n->mounted_uid;
		n->flags = c_n->flags;
	} else if (version != 5) {
		return NULL;
	}

	return raw_data;
}


struct compat_nfs_string {
	compat_uint_t len;
	compat_uptr_t data;
};

static inline void compat_nfs_string(struct nfs_string *dst,
				     struct compat_nfs_string *src)
{
	dst->data = compat_ptr(src->data);
	dst->len = src->len;
}

struct compat_nfs4_mount_data_v1 {
	compat_int_t version;
	compat_int_t flags;
	compat_int_t rsize;
	compat_int_t wsize;
	compat_int_t timeo;
	compat_int_t retrans;
	compat_int_t acregmin;
	compat_int_t acregmax;
	compat_int_t acdirmin;
	compat_int_t acdirmax;
	struct compat_nfs_string client_addr;
	struct compat_nfs_string mnt_path;
	struct compat_nfs_string hostname;
	compat_uint_t host_addrlen;
	compat_uptr_t host_addr;
	compat_int_t proto;
	compat_int_t auth_flavourlen;
	compat_uptr_t auth_flavours;
};

static int do_nfs4_super_data_conv(void *raw_data)
{
	int version = *(compat_uint_t *) raw_data;

	if (version == 1) {
		struct compat_nfs4_mount_data_v1 *raw = raw_data;
		struct nfs4_mount_data *real = raw_data;

		/* copy the fields backwards */
		real->auth_flavours = compat_ptr(raw->auth_flavours);
		real->auth_flavourlen = raw->auth_flavourlen;
		real->proto = raw->proto;
		real->host_addr = compat_ptr(raw->host_addr);
		real->host_addrlen = raw->host_addrlen;
		compat_nfs_string(&real->hostname, &raw->hostname);
		compat_nfs_string(&real->mnt_path, &raw->mnt_path);
		compat_nfs_string(&real->client_addr, &raw->client_addr);
		real->acdirmax = raw->acdirmax;
		real->acdirmin = raw->acdirmin;
		real->acregmax = raw->acregmax;
		real->acregmin = raw->acregmin;
		real->retrans = raw->retrans;
		real->timeo = raw->timeo;
		real->wsize = raw->wsize;
		real->rsize = raw->rsize;
		real->flags = raw->flags;
		real->version = raw->version;
	}

	return 0;
}

#define NCPFS_NAME      "ncpfs"
#define NFS4_NAME	"nfs4"

asmlinkage long compat_sys_mount(const char __user * dev_name,
				 const char __user * dir_name,
				 const char __user * type, unsigned long flags,
				 const void __user * data)
{
	char *kernel_type;
	unsigned long data_page;
	char *kernel_dev;
	char *dir_page;
	int retval;

	retval = copy_mount_string(type, &kernel_type);
	if (retval < 0)
		goto out;

	dir_page = getname(dir_name);
	retval = PTR_ERR(dir_page);
	if (IS_ERR(dir_page))
		goto out1;

	retval = copy_mount_string(dev_name, &kernel_dev);
	if (retval < 0)
		goto out2;

	retval = copy_mount_options(data, &data_page);
	if (retval < 0)
		goto out3;

	retval = -EINVAL;

	if (kernel_type && data_page) {
		if (!strcmp(kernel_type, NCPFS_NAME)) {
			do_ncp_super_data_conv((void *)data_page);
		} else if (!strcmp(kernel_type, NFS4_NAME)) {
			if (do_nfs4_super_data_conv((void *) data_page))
				goto out4;
		}
	}

	retval = do_mount(kernel_dev, dir_page, kernel_type,
			flags, (void*)data_page);

 out4:
	free_page(data_page);
 out3:
	kfree(kernel_dev);
 out2:
	putname(dir_page);
 out1:
	kfree(kernel_type);
 out:
	return retval;
}

struct compat_old_linux_dirent {
	compat_ulong_t	d_ino;
	compat_ulong_t	d_offset;
	unsigned short	d_namlen;
	char		d_name[1];
};

struct compat_readdir_callback {
	struct compat_old_linux_dirent __user *dirent;
	int result;
};

static int compat_fillonedir(void *__buf, const char *name, int namlen,
			loff_t offset, u64 ino, unsigned int d_type)
{
	struct compat_readdir_callback *buf = __buf;
	struct compat_old_linux_dirent __user *dirent;
	compat_ulong_t d_ino;

	if (buf->result)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
		buf->result = -EOVERFLOW;
		return -EOVERFLOW;
	}
	buf->result++;
	dirent = buf->dirent;
	if (!access_ok(VERIFY_WRITE, dirent,
			(unsigned long)(dirent->d_name + namlen + 1) -
				(unsigned long)dirent))
		goto efault;
	if (	__put_user(d_ino, &dirent->d_ino) ||
		__put_user(offset, &dirent->d_offset) ||
		__put_user(namlen, &dirent->d_namlen) ||
		__copy_to_user(dirent->d_name, name, namlen) ||
		__put_user(0, dirent->d_name + namlen))
		goto efault;
	return 0;
efault:
	buf->result = -EFAULT;
	return -EFAULT;
}

asmlinkage long compat_sys_old_readdir(unsigned int fd,
	struct compat_old_linux_dirent __user *dirent, unsigned int count)
{
	int error;
	struct file *file;
	struct compat_readdir_callback buf;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.result = 0;
	buf.dirent = dirent;

	error = vfs_readdir(file, compat_fillonedir, &buf);
	if (buf.result)
		error = buf.result;

	fput(file);
out:
	return error;
}

struct compat_linux_dirent {
	compat_ulong_t	d_ino;
	compat_ulong_t	d_off;
	unsigned short	d_reclen;
	char		d_name[1];
};

struct compat_getdents_callback {
	struct compat_linux_dirent __user *current_dir;
	struct compat_linux_dirent __user *previous;
	int count;
	int error;
};

static int compat_filldir(void *__buf, const char *name, int namlen,
		loff_t offset, u64 ino, unsigned int d_type)
{
	struct compat_linux_dirent __user * dirent;
	struct compat_getdents_callback *buf = __buf;
	compat_ulong_t d_ino;
	int reclen = ALIGN(offsetof(struct compat_linux_dirent, d_name) +
		namlen + 2, sizeof(compat_long_t));

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	d_ino = ino;
	if (sizeof(d_ino) < sizeof(ino) && d_ino != ino) {
		buf->error = -EOVERFLOW;
		return -EOVERFLOW;
	}
	dirent = buf->previous;
	if (dirent) {
		if (__put_user(offset, &dirent->d_off))
			goto efault;
	}
	dirent = buf->current_dir;
	if (__put_user(d_ino, &dirent->d_ino))
		goto efault;
	if (__put_user(reclen, &dirent->d_reclen))
		goto efault;
	if (copy_to_user(dirent->d_name, name, namlen))
		goto efault;
	if (__put_user(0, dirent->d_name + namlen))
		goto efault;
	if (__put_user(d_type, (char  __user *) dirent + reclen - 1))
		goto efault;
	buf->previous = dirent;
	dirent = (void __user *)dirent + reclen;
	buf->current_dir = dirent;
	buf->count -= reclen;
	return 0;
efault:
	buf->error = -EFAULT;
	return -EFAULT;
}

asmlinkage long compat_sys_getdents(unsigned int fd,
		struct compat_linux_dirent __user *dirent, unsigned int count)
{
	struct file * file;
	struct compat_linux_dirent __user * lastdirent;
	struct compat_getdents_callback buf;
	int error;

	error = -EFAULT;
	if (!access_ok(VERIFY_WRITE, dirent, count))
		goto out;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.current_dir = dirent;
	buf.previous = NULL;
	buf.count = count;
	buf.error = 0;

	error = vfs_readdir(file, compat_filldir, &buf);
	if (error >= 0)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		if (put_user(file->f_pos, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}
	fput(file);
out:
	return error;
}

#ifndef __ARCH_OMIT_COMPAT_SYS_GETDENTS64

struct compat_getdents_callback64 {
	struct linux_dirent64 __user *current_dir;
	struct linux_dirent64 __user *previous;
	int count;
	int error;
};

static int compat_filldir64(void * __buf, const char * name, int namlen, loff_t offset,
		     u64 ino, unsigned int d_type)
{
	struct linux_dirent64 __user *dirent;
	struct compat_getdents_callback64 *buf = __buf;
	int reclen = ALIGN(offsetof(struct linux_dirent64, d_name) + namlen + 1,
		sizeof(u64));
	u64 off;

	buf->error = -EINVAL;	/* only used if we fail.. */
	if (reclen > buf->count)
		return -EINVAL;
	dirent = buf->previous;

	if (dirent) {
		if (__put_user_unaligned(offset, &dirent->d_off))
			goto efault;
	}
	dirent = buf->current_dir;
	if (__put_user_unaligned(ino, &dirent->d_ino))
		goto efault;
	off = 0;
	if (__put_user_unaligned(off, &dirent->d_off))
		goto efault;
	if (__put_user(reclen, &dirent->d_reclen))
		goto efault;
	if (__put_user(d_type, &dirent->d_type))
		goto efault;
	if (copy_to_user(dirent->d_name, name, namlen))
		goto efault;
	if (__put_user(0, dirent->d_name + namlen))
		goto efault;
	buf->previous = dirent;
	dirent = (void __user *)dirent + reclen;
	buf->current_dir = dirent;
	buf->count -= reclen;
	return 0;
efault:
	buf->error = -EFAULT;
	return -EFAULT;
}

asmlinkage long compat_sys_getdents64(unsigned int fd,
		struct linux_dirent64 __user * dirent, unsigned int count)
{
	struct file * file;
	struct linux_dirent64 __user * lastdirent;
	struct compat_getdents_callback64 buf;
	int error;

	error = -EFAULT;
	if (!access_ok(VERIFY_WRITE, dirent, count))
		goto out;

	error = -EBADF;
	file = fget(fd);
	if (!file)
		goto out;

	buf.current_dir = dirent;
	buf.previous = NULL;
	buf.count = count;
	buf.error = 0;

	error = vfs_readdir(file, compat_filldir64, &buf);
	if (error >= 0)
		error = buf.error;
	lastdirent = buf.previous;
	if (lastdirent) {
		typeof(lastdirent->d_off) d_off = file->f_pos;
		if (__put_user_unaligned(d_off, &lastdirent->d_off))
			error = -EFAULT;
		else
			error = count - buf.count;
	}
	fput(file);
out:
	return error;
}
#endif /* ! __ARCH_OMIT_COMPAT_SYS_GETDENTS64 */

static ssize_t compat_do_readv_writev(int type, struct file *file,
			       const struct compat_iovec __user *uvector,
			       unsigned long nr_segs, loff_t *pos)
{
	compat_ssize_t tot_len;
	struct iovec iovstack[UIO_FASTIOV];
	struct iovec *iov = iovstack;
	ssize_t ret;
	io_fn_t fn;
	iov_fn_t fnv;

	ret = -EINVAL;
	if (!file->f_op)
		goto out;

	ret = -EFAULT;
	if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector)))
		goto out;

	tot_len = compat_rw_copy_check_uvector(type, uvector, nr_segs,
					       UIO_FASTIOV, iovstack, &iov);
	if (tot_len == 0) {
		ret = 0;
		goto out;
	}

	ret = rw_verify_area(type, file, pos, tot_len);
	if (ret < 0)
		goto out;

	fnv = NULL;
	if (type == READ) {
		fn = file->f_op->read;
		fnv = file->f_op->aio_read;
	} else {
		fn = (io_fn_t)file->f_op->write;
		fnv = file->f_op->aio_write;
	}

	if (fnv)
		ret = do_sync_readv_writev(file, iov, nr_segs, tot_len,
						pos, fnv);
	else
		ret = do_loop_readv_writev(file, iov, nr_segs, pos, fn);

out:
	if (iov != iovstack)
		kfree(iov);
	if ((ret + (type == READ)) > 0) {
		if (type == READ)
			fsnotify_access(file);
		else
			fsnotify_modify(file);
	}
	return ret;
}

static size_t compat_readv(struct file *file,
			   const struct compat_iovec __user *vec,
			   unsigned long vlen, loff_t *pos)
{
	ssize_t ret = -EBADF;

	if (!(file->f_mode & FMODE_READ))
		goto out;

	ret = -EINVAL;
	if (!file->f_op || (!file->f_op->aio_read && !file->f_op->read))
		goto out;

	ret = compat_do_readv_writev(READ, file, vec, vlen, pos);

out:
	if (ret > 0)
		add_rchar(current, ret);
	inc_syscr(current);
	return ret;
}

asmlinkage ssize_t
compat_sys_readv(unsigned long fd, const struct compat_iovec __user *vec,
		 unsigned long vlen)
{
	struct file *file;
	int fput_needed;
	ssize_t ret;

	file = fget_light(fd, &fput_needed);
	if (!file)
		return -EBADF;
	ret = compat_readv(file, vec, vlen, &file->f_pos);
	fput_light(file, fput_needed);
	return ret;
}

asmlinkage ssize_t
compat_sys_preadv(unsigned long fd, const struct compat_iovec __user *vec,
		  unsigned long vlen, u32 pos_low, u32 pos_high)
{
	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
	struct file *file;
	int fput_needed;
	ssize_t ret;

	if (pos < 0)
		return -EINVAL;
	file = fget_light(fd, &fput_needed);
	if (!file)
		return -EBADF;
	ret = -ESPIPE;
	if (file->f_mode & FMODE_PREAD)
		ret = compat_readv(file, vec, vlen, &pos);
	fput_light(file, fput_needed);
	return ret;
}

static size_t compat_writev(struct file *file,
			    const struct compat_iovec __user *vec,
			    unsigned long vlen, loff_t *pos)
{
	ssize_t ret = -EBADF;

	if (!(file->f_mode & FMODE_WRITE))
		goto out;

	ret = -EINVAL;
	if (!file->f_op || (!file->f_op->aio_write && !file->f_op->write))
		goto out;

	ret = compat_do_readv_writev(WRITE, file, vec, vlen, pos);

out:
	if (ret > 0)
		add_wchar(current, ret);
	inc_syscw(current);
	return ret;
}

asmlinkage ssize_t
compat_sys_writev(unsigned long fd, const struct compat_iovec __user *vec,
		  unsigned long vlen)
{
	struct file *file;
	int fput_needed;
	ssize_t ret;

	file = fget_light(fd, &fput_needed);
	if (!file)
		return -EBADF;
	ret = compat_writev(file, vec, vlen, &file->f_pos);
	fput_light(file, fput_needed);
	return ret;
}

asmlinkage ssize_t
compat_sys_pwritev(unsigned long fd, const struct compat_iovec __user *vec,
		   unsigned long vlen, u32 pos_low, u32 pos_high)
{
	loff_t pos = ((loff_t)pos_high << 32) | pos_low;
	struct file *file;
	int fput_needed;
	ssize_t ret;

	if (pos < 0)
		return -EINVAL;
	file = fget_light(fd, &fput_needed);
	if (!file)
		return -EBADF;
	ret = -ESPIPE;
	if (file->f_mode & FMODE_PWRITE)
		ret = compat_writev(file, vec, vlen, &pos);
	fput_light(file, fput_needed);
	return ret;
}

asmlinkage long
compat_sys_vmsplice(int fd, const struct compat_iovec __user *iov32,
		    unsigned int nr_segs, unsigned int flags)
{
	unsigned i;
	struct iovec __user *iov;
	if (nr_segs > UIO_MAXIOV)
		return -EINVAL;
	iov = compat_alloc_user_space(nr_segs * sizeof(struct iovec));
	for (i = 0; i < nr_segs; i++) {
		struct compat_iovec v;
		if (get_user(v.iov_base, &iov32[i].iov_base) ||
		    get_user(v.iov_len, &iov32[i].iov_len) ||
		    put_user(compat_ptr(v.iov_base), &iov[i].iov_base) ||
		    put_user(v.iov_len, &iov[i].iov_len))
			return -EFAULT;
	}
	return sys_vmsplice(fd, iov, nr_segs, flags);
}

/*
 * Exactly like fs/open.c:sys_open(), except that it doesn't set the
 * O_LARGEFILE flag.
 */
asmlinkage long
compat_sys_open(const char __user *filename, int flags, int mode)
{
	return do_sys_open(AT_FDCWD, filename, flags, mode);
}

/*
 * Exactly like fs/open.c:sys_openat(), except that it doesn't set the
 * O_LARGEFILE flag.
 */
asmlinkage long
compat_sys_openat(unsigned int dfd, const char __user *filename, int flags, int mode)
{
	return do_sys_open(dfd, filename, flags, mode);
}

#define __COMPAT_NFDBITS       (8 * sizeof(compat_ulong_t))

static int poll_select_copy_remaining(struct timespec *end_time, void __user *p,
				      int timeval, int ret)
{
	struct timespec ts;

	if (!p)
		return ret;

	if (current->personality & STICKY_TIMEOUTS)
		goto sticky;

	/* No update for zero timeout */
	if (!end_time->tv_sec && !end_time->tv_nsec)
		return ret;

	ktime_get_ts(&ts);
	ts = timespec_sub(*end_time, ts);
	if (ts.tv_sec < 0)
		ts.tv_sec = ts.tv_nsec = 0;

	if (timeval) {
		struct compat_timeval rtv;

		rtv.tv_sec = ts.tv_sec;
		rtv.tv_usec = ts.tv_nsec / NSEC_PER_USEC;

		if (!copy_to_user(p, &rtv, sizeof(rtv)))
			return ret;
	} else {
		struct compat_timespec rts;

		rts.tv_sec = ts.tv_sec;
		rts.tv_nsec = ts.tv_nsec;

		if (!copy_to_user(p, &rts, sizeof(rts)))
			return ret;
	}
	/*
	 * If an application puts its timeval in read-only memory, we
	 * don't want the Linux-specific update to the timeval to
	 * cause a fault after the select has completed
	 * successfully. However, because we're not updating the
	 * timeval, we can't restart the system call.
	 */

sticky:
	if (ret == -ERESTARTNOHAND)
		ret = -EINTR;
	return ret;
}

/*
 * Ooo, nasty.  We need here to frob 32-bit unsigned longs to
 * 64-bit unsigned longs.
 */
static
int compat_get_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
			unsigned long *fdset)
{
	nr = DIV_ROUND_UP(nr, __COMPAT_NFDBITS);
	if (ufdset) {
		unsigned long odd;

		if (!access_ok(VERIFY_WRITE, ufdset, nr*sizeof(compat_ulong_t)))
			return -EFAULT;

		odd = nr & 1UL;
		nr &= ~1UL;
		while (nr) {
			unsigned long h, l;
			if (__get_user(l, ufdset) || __get_user(h, ufdset+1))
				return -EFAULT;
			ufdset += 2;
			*fdset++ = h << 32 | l;
			nr -= 2;
		}
		if (odd && __get_user(*fdset, ufdset))
			return -EFAULT;
	} else {
		/* Tricky, must clear full unsigned long in the
		 * kernel fdset at the end, this makes sure that
		 * actually happens.
		 */
		memset(fdset, 0, ((nr + 1) & ~1)*sizeof(compat_ulong_t));
	}
	return 0;
}

static
int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
		      unsigned long *fdset)
{
	unsigned long odd;
	nr = DIV_ROUND_UP(nr, __COMPAT_NFDBITS);

	if (!ufdset)
		return 0;

	odd = nr & 1UL;
	nr &= ~1UL;
	while (nr) {
		unsigned long h, l;
		l = *fdset++;
		h = l >> 32;
		if (__put_user(l, ufdset) || __put_user(h, ufdset+1))
			return -EFAULT;
		ufdset += 2;
		nr -= 2;
	}
	if (odd && __put_user(*fdset, ufdset))
		return -EFAULT;
	return 0;
}


/*
 * This is a virtual copy of sys_select from fs/select.c and probably
 * should be compared to it from time to time
 */

/*
 * We can actually return ERESTARTSYS instead of EINTR, but I'd
 * like to be certain this leads to no problems. So I return
 * EINTR just for safety.
 *
 * Update: ERESTARTSYS breaks at least the xview clock binary, so
 * I'm trying ERESTARTNOHAND which restart only when you want to.
 */
int compat_core_sys_select(int n, compat_ulong_t __user *inp,
	compat_ulong_t __user *outp, compat_ulong_t __user *exp,
	struct timespec *end_time)
{
	fd_set_bits fds;
	void *bits;
	int size, max_fds, ret = -EINVAL;
	struct fdtable *fdt;
	long stack_fds[SELECT_STACK_ALLOC/sizeof(long)];

	if (n < 0)
		goto out_nofds;

	/* max_fds can increase, so grab it once to avoid race */
	rcu_read_lock();
	fdt = files_fdtable(current->files);
	max_fds = fdt->max_fds;
	rcu_read_unlock();
	if (n > max_fds)
		n = max_fds;

	/*
	 * We need 6 bitmaps (in/out/ex for both incoming and outgoing),
	 * since we used fdset we need to allocate memory in units of
	 * long-words.
	 */
	size = FDS_BYTES(n);
	bits = stack_fds;
	if (size > sizeof(stack_fds) / 6) {
		bits = kmalloc(6 * size, GFP_KERNEL);
		ret = -ENOMEM;
		if (!bits)
			goto out_nofds;
	}
	fds.in      = (unsigned long *)  bits;
	fds.out     = (unsigned long *) (bits +   size);
	fds.ex      = (unsigned long *) (bits + 2*size);
	fds.res_in  = (unsigned long *) (bits + 3*size);
	fds.res_out = (unsigned long *) (bits + 4*size);
	fds.res_ex  = (unsigned long *) (bits + 5*size);

	if ((ret = compat_get_fd_set(n, inp, fds.in)) ||
	    (ret = compat_get_fd_set(n, outp, fds.out)) ||
	    (ret = compat_get_fd_set(n, exp, fds.ex)))
		goto out;
	zero_fd_set(n, fds.res_in);
	zero_fd_set(n, fds.res_out);
	zero_fd_set(n, fds.res_ex);

	ret = do_select(n, &fds, end_time);

	if (ret < 0)
		goto out;
	if (!ret) {
		ret = -ERESTARTNOHAND;
		if (signal_pending(current))
			goto out;
		ret = 0;
	}

	if (compat_set_fd_set(n, inp, fds.res_in) ||
	    compat_set_fd_set(n, outp, fds.res_out) ||
	    compat_set_fd_set(n, exp, fds.res_ex))
		ret = -EFAULT;
out:
	if (bits != stack_fds)
		kfree(bits);
out_nofds:
	return ret;
}

asmlinkage long compat_sys_select(int n, compat_ulong_t __user *inp,
	compat_ulong_t __user *outp, compat_ulong_t __user *exp,
	struct compat_timeval __user *tvp)
{
	struct timespec end_time, *to = NULL;
	struct compat_timeval tv;
	int ret;

	if (tvp) {
		if (copy_from_user(&tv, tvp, sizeof(tv)))
			return -EFAULT;

		to = &end_time;
		if (poll_select_set_timeout(to,
				tv.tv_sec + (tv.tv_usec / USEC_PER_SEC),
				(tv.tv_usec % USEC_PER_SEC) * NSEC_PER_USEC))
			return -EINVAL;
	}

	ret = compat_core_sys_select(n, inp, outp, exp, to);
	ret = poll_select_copy_remaining(&end_time, tvp, 1, ret);

	return ret;
}

struct compat_sel_arg_struct {
	compat_ulong_t n;
	compat_uptr_t inp;
	compat_uptr_t outp;
	compat_uptr_t exp;
	compat_uptr_t tvp;
};

asmlinkage long compat_sys_old_select(struct compat_sel_arg_struct __user *arg)
{
	struct compat_sel_arg_struct a;

	if (copy_from_user(&a, arg, sizeof(a)))
		return -EFAULT;
	return compat_sys_select(a.n, compat_ptr(a.inp), compat_ptr(a.outp),
				 compat_ptr(a.exp), compat_ptr(a.tvp));
}

#ifdef HAVE_SET_RESTORE_SIGMASK
static long do_compat_pselect(int n, compat_ulong_t __user *inp,
	compat_ulong_t __user *outp, compat_ulong_t __user *exp,
	struct compat_timespec __user *tsp, compat_sigset_t __user *sigmask,
	compat_size_t sigsetsize)
{
	compat_sigset_t ss32;
	sigset_t ksigmask, sigsaved;
	struct compat_timespec ts;
	struct timespec end_time, *to = NULL;
	int ret;

	if (tsp) {
		if (copy_from_user(&ts, tsp, sizeof(ts)))
			return -EFAULT;

		to = &end_time;
		if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
			return -EINVAL;
	}

	if (sigmask) {
		if (sigsetsize != sizeof(compat_sigset_t))
			return -EINVAL;
		if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
			return -EFAULT;
		sigset_from_compat(&ksigmask, &ss32);

		sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP));
		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
	}

	ret = compat_core_sys_select(n, inp, outp, exp, to);
	ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);

	if (ret == -ERESTARTNOHAND) {
		/*
		 * Don't restore the signal mask yet. Let do_signal() deliver
		 * the signal on the way back to userspace, before the signal
		 * mask is restored.
		 */
		if (sigmask) {
			memcpy(&current->saved_sigmask, &sigsaved,
					sizeof(sigsaved));
			set_restore_sigmask();
		}
	} else if (sigmask)
		sigprocmask(SIG_SETMASK, &sigsaved, NULL);

	return ret;
}

asmlinkage long compat_sys_pselect6(int n, compat_ulong_t __user *inp,
	compat_ulong_t __user *outp, compat_ulong_t __user *exp,
	struct compat_timespec __user *tsp, void __user *sig)
{
	compat_size_t sigsetsize = 0;
	compat_uptr_t up = 0;

	if (sig) {
		if (!access_ok(VERIFY_READ, sig,
				sizeof(compat_uptr_t)+sizeof(compat_size_t)) ||
		    	__get_user(up, (compat_uptr_t __user *)sig) ||
		    	__get_user(sigsetsize,
				(compat_size_t __user *)(sig+sizeof(up))))
			return -EFAULT;
	}
	return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(up),
				 sigsetsize);
}

asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds,
	unsigned int nfds, struct compat_timespec __user *tsp,
	const compat_sigset_t __user *sigmask, compat_size_t sigsetsize)
{
	compat_sigset_t ss32;
	sigset_t ksigmask, sigsaved;
	struct compat_timespec ts;
	struct timespec end_time, *to = NULL;
	int ret;

	if (tsp) {
		if (copy_from_user(&ts, tsp, sizeof(ts)))
			return -EFAULT;

		to = &end_time;
		if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
			return -EINVAL;
	}

	if (sigmask) {
		if (sigsetsize != sizeof(compat_sigset_t))
			return -EINVAL;
		if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
			return -EFAULT;
		sigset_from_compat(&ksigmask, &ss32);

		sigdelsetmask(&ksigmask, sigmask(SIGKILL)|sigmask(SIGSTOP));
		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
	}

	ret = do_sys_poll(ufds, nfds, to);

	/* We can restart this syscall, usually */
	if (ret == -EINTR) {
		/*
		 * Don't restore the signal mask yet. Let do_signal() deliver
		 * the signal on the way back to userspace, before the signal
		 * mask is restored.
		 */
		if (sigmask) {
			memcpy(&current->saved_sigmask, &sigsaved,
				sizeof(sigsaved));
			set_restore_sigmask();
		}
		ret = -ERESTARTNOHAND;
	} else if (sigmask)
		sigprocmask(SIG_SETMASK, &sigsaved, NULL);

	ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);

	return ret;
}
#endif /* HAVE_SET_RESTORE_SIGMASK */

#ifdef CONFIG_EPOLL

#ifdef HAVE_SET_RESTORE_SIGMASK
asmlinkage long compat_sys_epoll_pwait(int epfd,
			struct compat_epoll_event __user *events,
			int maxevents, int timeout,
			const compat_sigset_t __user *sigmask,
			compat_size_t sigsetsize)
{
	long err;
	compat_sigset_t csigmask;
	sigset_t ksigmask, sigsaved;

	/*
	 * If the caller wants a certain signal mask to be set during the wait,
	 * we apply it here.
	 */
	if (sigmask) {
		if (sigsetsize != sizeof(compat_sigset_t))
			return -EINVAL;
		if (copy_from_user(&csigmask, sigmask, sizeof(csigmask)))
			return -EFAULT;
		sigset_from_compat(&ksigmask, &csigmask);
		sigdelsetmask(&ksigmask, sigmask(SIGKILL) | sigmask(SIGSTOP));
		sigprocmask(SIG_SETMASK, &ksigmask, &sigsaved);
	}

	err = sys_epoll_wait(epfd, events, maxevents, timeout);

	/*
	 * If we changed the signal mask, we need to restore the original one.
	 * In case we've got a signal while waiting, we do not restore the
	 * signal mask yet, and we allow do_signal() to deliver the signal on
	 * the way back to userspace, before the signal mask is restored.
	 */
	if (sigmask) {
		if (err == -EINTR) {
			memcpy(&current->saved_sigmask, &sigsaved,
			       sizeof(sigsaved));
			set_restore_sigmask();
		} else
			sigprocmask(SIG_SETMASK, &sigsaved, NULL);
	}

	return err;
}
#endif /* HAVE_SET_RESTORE_SIGMASK */

#endif /* CONFIG_EPOLL */

#ifdef CONFIG_SIGNALFD

asmlinkage long compat_sys_signalfd4(int ufd,
				     const compat_sigset_t __user *sigmask,
				     compat_size_t sigsetsize, int flags)
{
	compat_sigset_t ss32;
	sigset_t tmp;
	sigset_t __user *ksigmask;

	if (sigsetsize != sizeof(compat_sigset_t))
		return -EINVAL;
	if (copy_from_user(&ss32, sigmask, sizeof(ss32)))
		return -EFAULT;
	sigset_from_compat(&tmp, &ss32);
	ksigmask = compat_alloc_user_space(sizeof(sigset_t));
	if (copy_to_user(ksigmask, &tmp, sizeof(sigset_t)))
		return -EFAULT;

	return sys_signalfd4(ufd, ksigmask, sizeof(sigset_t), flags);
}

asmlinkage long compat_sys_signalfd(int ufd,
				    const compat_sigset_t __user *sigmask,
				    compat_size_t sigsetsize)
{
	return compat_sys_signalfd4(ufd, sigmask, sigsetsize, 0);
}
#endif /* CONFIG_SIGNALFD */

#ifdef CONFIG_TIMERFD

asmlinkage long compat_sys_timerfd_settime(int ufd, int flags,
				   const struct compat_itimerspec __user *utmr,
				   struct compat_itimerspec __user *otmr)
{
	int error;
	struct itimerspec t;
	struct itimerspec __user *ut;

	if (get_compat_itimerspec(&t, utmr))
		return -EFAULT;
	ut = compat_alloc_user_space(2 * sizeof(struct itimerspec));
	if (copy_to_user(&ut[0], &t, sizeof(t)))
		return -EFAULT;
	error = sys_timerfd_settime(ufd, flags, &ut[0], &ut[1]);
	if (!error && otmr)
		error = (copy_from_user(&t, &ut[1], sizeof(struct itimerspec)) ||
			 put_compat_itimerspec(otmr, &t)) ? -EFAULT: 0;

	return error;
}

asmlinkage long compat_sys_timerfd_gettime(int ufd,
				   struct compat_itimerspec __user *otmr)
{
	int error;
	struct itimerspec t;
	struct itimerspec __user *ut;

	ut = compat_alloc_user_space(sizeof(struct itimerspec));
	error = sys_timerfd_gettime(ufd, ut);
	if (!error)
		error = (copy_from_user(&t, ut, sizeof(struct itimerspec)) ||
			 put_compat_itimerspec(otmr, &t)) ? -EFAULT: 0;

	return error;
}

#endif /* CONFIG_TIMERFD */

#ifdef CONFIG_FHANDLE
/*
 * Exactly like fs/open.c:sys_open_by_handle_at(), except that it
 * doesn't set the O_LARGEFILE flag.
 */
asmlinkage long
compat_sys_open_by_handle_at(int mountdirfd,
			     struct file_handle __user *handle, int flags)
{
	return do_handle_open(mountdirfd, handle, flags);
}
#endif