summaryrefslogtreecommitdiff
path: root/fs/proc/base.c
blob: 92166c33395db093123cd52a0ae13add8100d148 (plain)
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
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
// SPDX-License-Identifier: GPL-2.0
/*
 *  linux/fs/proc/base.c
 *
 *  Copyright (C) 1991, 1992 Linus Torvalds
 *
 *  proc base directory handling functions
 *
 *  1999, Al Viro. Rewritten. Now it covers the whole per-process part.
 *  Instead of using magical inumbers to determine the kind of object
 *  we allocate and fill in-core inodes upon lookup. They don't even
 *  go into icache. We cache the reference to task_struct upon lookup too.
 *  Eventually it should become a filesystem in its own. We don't use the
 *  rest of procfs anymore.
 *
 *
 *  Changelog:
 *  17-Jan-2005
 *  Allan Bezerra
 *  Bruna Moreira <bruna.moreira@indt.org.br>
 *  Edjard Mota <edjard.mota@indt.org.br>
 *  Ilias Biris <ilias.biris@indt.org.br>
 *  Mauricio Lin <mauricio.lin@indt.org.br>
 *
 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
 *
 *  A new process specific entry (smaps) included in /proc. It shows the
 *  size of rss for each memory area. The maps entry lacks information
 *  about physical memory size (rss) for each mapped file, i.e.,
 *  rss information for executables and library files.
 *  This additional information is useful for any tools that need to know
 *  about physical memory consumption for a process specific library.
 *
 *  Changelog:
 *  21-Feb-2005
 *  Embedded Linux Lab - 10LE Instituto Nokia de Tecnologia - INdT
 *  Pud inclusion in the page table walking.
 *
 *  ChangeLog:
 *  10-Mar-2005
 *  10LE Instituto Nokia de Tecnologia - INdT:
 *  A better way to walks through the page table as suggested by Hugh Dickins.
 *
 *  Simo Piiroinen <simo.piiroinen@nokia.com>:
 *  Smaps information related to shared, private, clean and dirty pages.
 *
 *  Paul Mundt <paul.mundt@nokia.com>:
 *  Overall revision about smaps.
 */

#include <linux/uaccess.h>

#include <linux/errno.h>
#include <linux/time.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/task_io_accounting_ops.h>
#include <linux/init.h>
#include <linux/capability.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/generic-radix-tree.h>
#include <linux/string.h>
#include <linux/seq_file.h>
#include <linux/namei.h>
#include <linux/mnt_namespace.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/rcupdate.h>
#include <linux/kallsyms.h>
#include <linux/stacktrace.h>
#include <linux/resource.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/security.h>
#include <linux/ptrace.h>
#include <linux/printk.h>
#include <linux/cache.h>
#include <linux/cgroup.h>
#include <linux/cpuset.h>
#include <linux/audit.h>
#include <linux/poll.h>
#include <linux/nsproxy.h>
#include <linux/oom.h>
#include <linux/elf.h>
#include <linux/pid_namespace.h>
#include <linux/user_namespace.h>
#include <linux/fs_struct.h>
#include <linux/slab.h>
#include <linux/sched/autogroup.h>
#include <linux/sched/mm.h>
#include <linux/sched/coredump.h>
#include <linux/sched/debug.h>
#include <linux/sched/stat.h>
#include <linux/posix-timers.h>
#include <linux/time_namespace.h>
#include <linux/resctrl.h>
#include <linux/cn_proc.h>
#include <trace/events/oom.h>
#include "internal.h"
#include "fd.h"

#include "../../lib/kstrtox.h"

/* NOTE:
 *	Implementing inode permission operations in /proc is almost
 *	certainly an error.  Permission checks need to happen during
 *	each system call not at open time.  The reason is that most of
 *	what we wish to check for permissions in /proc varies at runtime.
 *
 *	The classic example of a problem is opening file descriptors
 *	in /proc for a task before it execs a suid executable.
 */

static u8 nlink_tid __ro_after_init;
static u8 nlink_tgid __ro_after_init;

struct pid_entry {
	const char *name;
	unsigned int len;
	umode_t mode;
	const struct inode_operations *iop;
	const struct file_operations *fop;
	union proc_op op;
};

#define NOD(NAME, MODE, IOP, FOP, OP) {			\
	.name = (NAME),					\
	.len  = sizeof(NAME) - 1,			\
	.mode = MODE,					\
	.iop  = IOP,					\
	.fop  = FOP,					\
	.op   = OP,					\
}

#define DIR(NAME, MODE, iops, fops)	\
	NOD(NAME, (S_IFDIR|(MODE)), &iops, &fops, {} )
#define LNK(NAME, get_link)					\
	NOD(NAME, (S_IFLNK|S_IRWXUGO),				\
		&proc_pid_link_inode_operations, NULL,		\
		{ .proc_get_link = get_link } )
#define REG(NAME, MODE, fops)				\
	NOD(NAME, (S_IFREG|(MODE)), NULL, &fops, {})
#define ONE(NAME, MODE, show)				\
	NOD(NAME, (S_IFREG|(MODE)),			\
		NULL, &proc_single_file_operations,	\
		{ .proc_show = show } )
#define ATTR(LSM, NAME, MODE)				\
	NOD(NAME, (S_IFREG|(MODE)),			\
		NULL, &proc_pid_attr_operations,	\
		{ .lsm = LSM })

/*
 * Count the number of hardlinks for the pid_entry table, excluding the .
 * and .. links.
 */
static unsigned int __init pid_entry_nlink(const struct pid_entry *entries,
	unsigned int n)
{
	unsigned int i;
	unsigned int count;

	count = 2;
	for (i = 0; i < n; ++i) {
		if (S_ISDIR(entries[i].mode))
			++count;
	}

	return count;
}

static int get_task_root(struct task_struct *task, struct path *root)
{
	int result = -ENOENT;

	task_lock(task);
	if (task->fs) {
		get_fs_root(task->fs, root);
		result = 0;
	}
	task_unlock(task);
	return result;
}

static int proc_cwd_link(struct dentry *dentry, struct path *path)
{
	struct task_struct *task = get_proc_task(d_inode(dentry));
	int result = -ENOENT;

	if (task) {
		task_lock(task);
		if (task->fs) {
			get_fs_pwd(task->fs, path);
			result = 0;
		}
		task_unlock(task);
		put_task_struct(task);
	}
	return result;
}

static int proc_root_link(struct dentry *dentry, struct path *path)
{
	struct task_struct *task = get_proc_task(d_inode(dentry));
	int result = -ENOENT;

	if (task) {
		result = get_task_root(task, path);
		put_task_struct(task);
	}
	return result;
}

/*
 * If the user used setproctitle(), we just get the string from
 * user space at arg_start, and limit it to a maximum of one page.
 */
static ssize_t get_mm_proctitle(struct mm_struct *mm, char __user *buf,
				size_t count, unsigned long pos,
				unsigned long arg_start)
{
	char *page;
	int ret, got;

	if (pos >= PAGE_SIZE)
		return 0;

	page = (char *)__get_free_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;

	ret = 0;
	got = access_remote_vm(mm, arg_start, page, PAGE_SIZE, FOLL_ANON);
	if (got > 0) {
		int len = strnlen(page, got);

		/* Include the NUL character if it was found */
		if (len < got)
			len++;

		if (len > pos) {
			len -= pos;
			if (len > count)
				len = count;
			len -= copy_to_user(buf, page+pos, len);
			if (!len)
				len = -EFAULT;
			ret = len;
		}
	}
	free_page((unsigned long)page);
	return ret;
}

static ssize_t get_mm_cmdline(struct mm_struct *mm, char __user *buf,
			      size_t count, loff_t *ppos)
{
	unsigned long arg_start, arg_end, env_start, env_end;
	unsigned long pos, len;
	char *page, c;

	/* Check if process spawned far enough to have cmdline. */
	if (!mm->env_end)
		return 0;

	spin_lock(&mm->arg_lock);
	arg_start = mm->arg_start;
	arg_end = mm->arg_end;
	env_start = mm->env_start;
	env_end = mm->env_end;
	spin_unlock(&mm->arg_lock);

	if (arg_start >= arg_end)
		return 0;

	/*
	 * We allow setproctitle() to overwrite the argument
	 * strings, and overflow past the original end. But
	 * only when it overflows into the environment area.
	 */
	if (env_start != arg_end || env_end < env_start)
		env_start = env_end = arg_end;
	len = env_end - arg_start;

	/* We're not going to care if "*ppos" has high bits set */
	pos = *ppos;
	if (pos >= len)
		return 0;
	if (count > len - pos)
		count = len - pos;
	if (!count)
		return 0;

	/*
	 * Magical special case: if the argv[] end byte is not
	 * zero, the user has overwritten it with setproctitle(3).
	 *
	 * Possible future enhancement: do this only once when
	 * pos is 0, and set a flag in the 'struct file'.
	 */
	if (access_remote_vm(mm, arg_end-1, &c, 1, FOLL_ANON) == 1 && c)
		return get_mm_proctitle(mm, buf, count, pos, arg_start);

	/*
	 * For the non-setproctitle() case we limit things strictly
	 * to the [arg_start, arg_end[ range.
	 */
	pos += arg_start;
	if (pos < arg_start || pos >= arg_end)
		return 0;
	if (count > arg_end - pos)
		count = arg_end - pos;

	page = (char *)__get_free_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;

	len = 0;
	while (count) {
		int got;
		size_t size = min_t(size_t, PAGE_SIZE, count);

		got = access_remote_vm(mm, pos, page, size, FOLL_ANON);
		if (got <= 0)
			break;
		got -= copy_to_user(buf, page, got);
		if (unlikely(!got)) {
			if (!len)
				len = -EFAULT;
			break;
		}
		pos += got;
		buf += got;
		len += got;
		count -= got;
	}

	free_page((unsigned long)page);
	return len;
}

static ssize_t get_task_cmdline(struct task_struct *tsk, char __user *buf,
				size_t count, loff_t *pos)
{
	struct mm_struct *mm;
	ssize_t ret;

	mm = get_task_mm(tsk);
	if (!mm)
		return 0;

	ret = get_mm_cmdline(mm, buf, count, pos);
	mmput(mm);
	return ret;
}

static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
				     size_t count, loff_t *pos)
{
	struct task_struct *tsk;
	ssize_t ret;

	BUG_ON(*pos < 0);

	tsk = get_proc_task(file_inode(file));
	if (!tsk)
		return -ESRCH;
	ret = get_task_cmdline(tsk, buf, count, pos);
	put_task_struct(tsk);
	if (ret > 0)
		*pos += ret;
	return ret;
}

static const struct file_operations proc_pid_cmdline_ops = {
	.read	= proc_pid_cmdline_read,
	.llseek	= generic_file_llseek,
};

#ifdef CONFIG_KALLSYMS
/*
 * Provides a wchan file via kallsyms in a proper one-value-per-file format.
 * Returns the resolved symbol.  If that fails, simply return the address.
 */
static int proc_pid_wchan(struct seq_file *m, struct pid_namespace *ns,
			  struct pid *pid, struct task_struct *task)
{
	unsigned long wchan;
	char symname[KSYM_NAME_LEN];

	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
		goto print0;

	wchan = get_wchan(task);
	if (wchan && !lookup_symbol_name(wchan, symname)) {
		seq_puts(m, symname);
		return 0;
	}

print0:
	seq_putc(m, '0');
	return 0;
}
#endif /* CONFIG_KALLSYMS */

static int lock_trace(struct task_struct *task)
{
	int err = down_read_killable(&task->signal->exec_update_lock);
	if (err)
		return err;
	if (!ptrace_may_access(task, PTRACE_MODE_ATTACH_FSCREDS)) {
		up_read(&task->signal->exec_update_lock);
		return -EPERM;
	}
	return 0;
}

static void unlock_trace(struct task_struct *task)
{
	up_read(&task->signal->exec_update_lock);
}

#ifdef CONFIG_STACKTRACE

#define MAX_STACK_TRACE_DEPTH	64

static int proc_pid_stack(struct seq_file *m, struct pid_namespace *ns,
			  struct pid *pid, struct task_struct *task)
{
	unsigned long *entries;
	int err;

	/*
	 * The ability to racily run the kernel stack unwinder on a running task
	 * and then observe the unwinder output is scary; while it is useful for
	 * debugging kernel issues, it can also allow an attacker to leak kernel
	 * stack contents.
	 * Doing this in a manner that is at least safe from races would require
	 * some work to ensure that the remote task can not be scheduled; and
	 * even then, this would still expose the unwinder as local attack
	 * surface.
	 * Therefore, this interface is restricted to root.
	 */
	if (!file_ns_capable(m->file, &init_user_ns, CAP_SYS_ADMIN))
		return -EACCES;

	entries = kmalloc_array(MAX_STACK_TRACE_DEPTH, sizeof(*entries),
				GFP_KERNEL);
	if (!entries)
		return -ENOMEM;

	err = lock_trace(task);
	if (!err) {
		unsigned int i, nr_entries;

		nr_entries = stack_trace_save_tsk(task, entries,
						  MAX_STACK_TRACE_DEPTH, 0);

		for (i = 0; i < nr_entries; i++) {
			seq_printf(m, "[<0>] %pB\n", (void *)entries[i]);
		}

		unlock_trace(task);
	}
	kfree(entries);

	return err;
}
#endif

#ifdef CONFIG_SCHED_INFO
/*
 * Provides /proc/PID/schedstat
 */
static int proc_pid_schedstat(struct seq_file *m, struct pid_namespace *ns,
			      struct pid *pid, struct task_struct *task)
{
	if (unlikely(!sched_info_on()))
		seq_puts(m, "0 0 0\n");
	else
		seq_printf(m, "%llu %llu %lu\n",
		   (unsigned long long)task->se.sum_exec_runtime,
		   (unsigned long long)task->sched_info.run_delay,
		   task->sched_info.pcount);

	return 0;
}
#endif

#ifdef CONFIG_LATENCYTOP
static int lstats_show_proc(struct seq_file *m, void *v)
{
	int i;
	struct inode *inode = m->private;
	struct task_struct *task = get_proc_task(inode);

	if (!task)
		return -ESRCH;
	seq_puts(m, "Latency Top version : v0.1\n");
	for (i = 0; i < LT_SAVECOUNT; i++) {
		struct latency_record *lr = &task->latency_record[i];
		if (lr->backtrace[0]) {
			int q;
			seq_printf(m, "%i %li %li",
				   lr->count, lr->time, lr->max);
			for (q = 0; q < LT_BACKTRACEDEPTH; q++) {
				unsigned long bt = lr->backtrace[q];

				if (!bt)
					break;
				seq_printf(m, " %ps", (void *)bt);
			}
			seq_putc(m, '\n');
		}

	}
	put_task_struct(task);
	return 0;
}

static int lstats_open(struct inode *inode, struct file *file)
{
	return single_open(file, lstats_show_proc, inode);
}

static ssize_t lstats_write(struct file *file, const char __user *buf,
			    size_t count, loff_t *offs)
{
	struct task_struct *task = get_proc_task(file_inode(file));

	if (!task)
		return -ESRCH;
	clear_tsk_latency_tracing(task);
	put_task_struct(task);

	return count;
}

static const struct file_operations proc_lstats_operations = {
	.open		= lstats_open,
	.read		= seq_read,
	.write		= lstats_write,
	.llseek		= seq_lseek,
	.release	= single_release,
};

#endif

static int proc_oom_score(struct seq_file *m, struct pid_namespace *ns,
			  struct pid *pid, struct task_struct *task)
{
	unsigned long totalpages = totalram_pages() + total_swap_pages;
	unsigned long points = 0;
	long badness;

	badness = oom_badness(task, totalpages);
	/*
	 * Special case OOM_SCORE_ADJ_MIN for all others scale the
	 * badness value into [0, 2000] range which we have been
	 * exporting for a long time so userspace might depend on it.
	 */
	if (badness != LONG_MIN)
		points = (1000 + badness * 1000 / (long)totalpages) * 2 / 3;

	seq_printf(m, "%lu\n", points);

	return 0;
}

struct limit_names {
	const char *name;
	const char *unit;
};

static const struct limit_names lnames[RLIM_NLIMITS] = {
	[RLIMIT_CPU] = {"Max cpu time", "seconds"},
	[RLIMIT_FSIZE] = {"Max file size", "bytes"},
	[RLIMIT_DATA] = {"Max data size", "bytes"},
	[RLIMIT_STACK] = {"Max stack size", "bytes"},
	[RLIMIT_CORE] = {"Max core file size", "bytes"},
	[RLIMIT_RSS] = {"Max resident set", "bytes"},
	[RLIMIT_NPROC] = {"Max processes", "processes"},
	[RLIMIT_NOFILE] = {"Max open files", "files"},
	[RLIMIT_MEMLOCK] = {"Max locked memory", "bytes"},
	[RLIMIT_AS] = {"Max address space", "bytes"},
	[RLIMIT_LOCKS] = {"Max file locks", "locks"},
	[RLIMIT_SIGPENDING] = {"Max pending signals", "signals"},
	[RLIMIT_MSGQUEUE] = {"Max msgqueue size", "bytes"},
	[RLIMIT_NICE] = {"Max nice priority", NULL},
	[RLIMIT_RTPRIO] = {"Max realtime priority", NULL},
	[RLIMIT_RTTIME] = {"Max realtime timeout", "us"},
};

/* Display limits for a process */
static int proc_pid_limits(struct seq_file *m, struct pid_namespace *ns,
			   struct pid *pid, struct task_struct *task)
{
	unsigned int i;
	unsigned long flags;

	struct rlimit rlim[RLIM_NLIMITS];

	if (!lock_task_sighand(task, &flags))
		return 0;
	memcpy(rlim, task->signal->rlim, sizeof(struct rlimit) * RLIM_NLIMITS);
	unlock_task_sighand(task, &flags);

	/*
	 * print the file header
	 */
	seq_puts(m, "Limit                     "
		"Soft Limit           "
		"Hard Limit           "
		"Units     \n");

	for (i = 0; i < RLIM_NLIMITS; i++) {
		if (rlim[i].rlim_cur == RLIM_INFINITY)
			seq_printf(m, "%-25s %-20s ",
				   lnames[i].name, "unlimited");
		else
			seq_printf(m, "%-25s %-20lu ",
				   lnames[i].name, rlim[i].rlim_cur);

		if (rlim[i].rlim_max == RLIM_INFINITY)
			seq_printf(m, "%-20s ", "unlimited");
		else
			seq_printf(m, "%-20lu ", rlim[i].rlim_max);

		if (lnames[i].unit)
			seq_printf(m, "%-10s\n", lnames[i].unit);
		else
			seq_putc(m, '\n');
	}

	return 0;
}

#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
static int proc_pid_syscall(struct seq_file *m, struct pid_namespace *ns,
			    struct pid *pid, struct task_struct *task)
{
	struct syscall_info info;
	u64 *args = &info.data.args[0];
	int res;

	res = lock_trace(task);
	if (res)
		return res;

	if (task_current_syscall(task, &info))
		seq_puts(m, "running\n");
	else if (info.data.nr < 0)
		seq_printf(m, "%d 0x%llx 0x%llx\n",
			   info.data.nr, info.sp, info.data.instruction_pointer);
	else
		seq_printf(m,
		       "%d 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx 0x%llx\n",
		       info.data.nr,
		       args[0], args[1], args[2], args[3], args[4], args[5],
		       info.sp, info.data.instruction_pointer);
	unlock_trace(task);

	return 0;
}
#endif /* CONFIG_HAVE_ARCH_TRACEHOOK */

/************************************************************************/
/*                       Here the fs part begins                        */
/************************************************************************/

/* permission checks */
static bool proc_fd_access_allowed(struct inode *inode)
{
	struct task_struct *task;
	bool allowed = false;
	/* Allow access to a task's file descriptors if it is us or we
	 * may use ptrace attach to the process and find out that
	 * information.
	 */
	task = get_proc_task(inode);
	if (task) {
		allowed = ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
		put_task_struct(task);
	}
	return allowed;
}

int proc_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
		 struct iattr *attr)
{
	int error;
	struct inode *inode = d_inode(dentry);

	if (attr->ia_valid & ATTR_MODE)
		return -EPERM;

	error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
	if (error)
		return error;

	setattr_copy(&nop_mnt_idmap, inode, attr);
	mark_inode_dirty(inode);
	return 0;
}

/*
 * May current process learn task's sched/cmdline info (for hide_pid_min=1)
 * or euid/egid (for hide_pid_min=2)?
 */
static bool has_pid_permissions(struct proc_fs_info *fs_info,
				 struct task_struct *task,
				 enum proc_hidepid hide_pid_min)
{
	/*
	 * If 'hidpid' mount option is set force a ptrace check,
	 * we indicate that we are using a filesystem syscall
	 * by passing PTRACE_MODE_READ_FSCREDS
	 */
	if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE)
		return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);

	if (fs_info->hide_pid < hide_pid_min)
		return true;
	if (in_group_p(fs_info->pid_gid))
		return true;
	return ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS);
}


static int proc_pid_permission(struct user_namespace *mnt_userns,
			       struct inode *inode, int mask)
{
	struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
	struct task_struct *task;
	bool has_perms;

	task = get_proc_task(inode);
	if (!task)
		return -ESRCH;
	has_perms = has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS);
	put_task_struct(task);

	if (!has_perms) {
		if (fs_info->hide_pid == HIDEPID_INVISIBLE) {
			/*
			 * Let's make getdents(), stat(), and open()
			 * consistent with each other.  If a process
			 * may not stat() a file, it shouldn't be seen
			 * in procfs at all.
			 */
			return -ENOENT;
		}

		return -EPERM;
	}
	return generic_permission(&init_user_ns, inode, mask);
}



static const struct inode_operations proc_def_inode_operations = {
	.setattr	= proc_setattr,
};

static int proc_single_show(struct seq_file *m, void *v)
{
	struct inode *inode = m->private;
	struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
	struct pid *pid = proc_pid(inode);
	struct task_struct *task;
	int ret;

	task = get_pid_task(pid, PIDTYPE_PID);
	if (!task)
		return -ESRCH;

	ret = PROC_I(inode)->op.proc_show(m, ns, pid, task);

	put_task_struct(task);
	return ret;
}

static int proc_single_open(struct inode *inode, struct file *filp)
{
	return single_open(filp, proc_single_show, inode);
}

static const struct file_operations proc_single_file_operations = {
	.open		= proc_single_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};


struct mm_struct *proc_mem_open(struct inode *inode, unsigned int mode)
{
	struct task_struct *task = get_proc_task(inode);
	struct mm_struct *mm = ERR_PTR(-ESRCH);

	if (task) {
		mm = mm_access(task, mode | PTRACE_MODE_FSCREDS);
		put_task_struct(task);

		if (!IS_ERR_OR_NULL(mm)) {
			/* ensure this mm_struct can't be freed */
			mmgrab(mm);
			/* but do not pin its memory */
			mmput(mm);
		}
	}

	return mm;
}

static int __mem_open(struct inode *inode, struct file *file, unsigned int mode)
{
	struct mm_struct *mm = proc_mem_open(inode, mode);

	if (IS_ERR(mm))
		return PTR_ERR(mm);

	file->private_data = mm;
	return 0;
}

static int mem_open(struct inode *inode, struct file *file)
{
	int ret = __mem_open(inode, file, PTRACE_MODE_ATTACH);

	/* OK to pass negative loff_t, we can catch out-of-range */
	file->f_mode |= FMODE_UNSIGNED_OFFSET;

	return ret;
}

static ssize_t mem_rw(struct file *file, char __user *buf,
			size_t count, loff_t *ppos, int write)
{
	struct mm_struct *mm = file->private_data;
	unsigned long addr = *ppos;
	ssize_t copied;
	char *page;
	unsigned int flags;

	if (!mm)
		return 0;

	page = (char *)__get_free_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;

	copied = 0;
	if (!mmget_not_zero(mm))
		goto free;

	flags = FOLL_FORCE | (write ? FOLL_WRITE : 0);

	while (count > 0) {
		size_t this_len = min_t(size_t, count, PAGE_SIZE);

		if (write && copy_from_user(page, buf, this_len)) {
			copied = -EFAULT;
			break;
		}

		this_len = access_remote_vm(mm, addr, page, this_len, flags);
		if (!this_len) {
			if (!copied)
				copied = -EIO;
			break;
		}

		if (!write && copy_to_user(buf, page, this_len)) {
			copied = -EFAULT;
			break;
		}

		buf += this_len;
		addr += this_len;
		copied += this_len;
		count -= this_len;
	}
	*ppos = addr;

	mmput(mm);
free:
	free_page((unsigned long) page);
	return copied;
}

static ssize_t mem_read(struct file *file, char __user *buf,
			size_t count, loff_t *ppos)
{
	return mem_rw(file, buf, count, ppos, 0);
}

static ssize_t mem_write(struct file *file, const char __user *buf,
			 size_t count, loff_t *ppos)
{
	return mem_rw(file, (char __user*)buf, count, ppos, 1);
}

loff_t mem_lseek(struct file *file, loff_t offset, int orig)
{
	switch (orig) {
	case 0:
		file->f_pos = offset;
		break;
	case 1:
		file->f_pos += offset;
		break;
	default:
		return -EINVAL;
	}
	force_successful_syscall_return();
	return file->f_pos;
}

static int mem_release(struct inode *inode, struct file *file)
{
	struct mm_struct *mm = file->private_data;
	if (mm)
		mmdrop(mm);
	return 0;
}

static const struct file_operations proc_mem_operations = {
	.llseek		= mem_lseek,
	.read		= mem_read,
	.write		= mem_write,
	.open		= mem_open,
	.release	= mem_release,
};

static int environ_open(struct inode *inode, struct file *file)
{
	return __mem_open(inode, file, PTRACE_MODE_READ);
}

static ssize_t environ_read(struct file *file, char __user *buf,
			size_t count, loff_t *ppos)
{
	char *page;
	unsigned long src = *ppos;
	int ret = 0;
	struct mm_struct *mm = file->private_data;
	unsigned long env_start, env_end;

	/* Ensure the process spawned far enough to have an environment. */
	if (!mm || !mm->env_end)
		return 0;

	page = (char *)__get_free_page(GFP_KERNEL);
	if (!page)
		return -ENOMEM;

	ret = 0;
	if (!mmget_not_zero(mm))
		goto free;

	spin_lock(&mm->arg_lock);
	env_start = mm->env_start;
	env_end = mm->env_end;
	spin_unlock(&mm->arg_lock);

	while (count > 0) {
		size_t this_len, max_len;
		int retval;

		if (src >= (env_end - env_start))
			break;

		this_len = env_end - (env_start + src);

		max_len = min_t(size_t, PAGE_SIZE, count);
		this_len = min(max_len, this_len);

		retval = access_remote_vm(mm, (env_start + src), page, this_len, FOLL_ANON);

		if (retval <= 0) {
			ret = retval;
			break;
		}

		if (copy_to_user(buf, page, retval)) {
			ret = -EFAULT;
			break;
		}

		ret += retval;
		src += retval;
		buf += retval;
		count -= retval;
	}
	*ppos = src;
	mmput(mm);

free:
	free_page((unsigned long) page);
	return ret;
}

static const struct file_operations proc_environ_operations = {
	.open		= environ_open,
	.read		= environ_read,
	.llseek		= generic_file_llseek,
	.release	= mem_release,
};

static int auxv_open(struct inode *inode, struct file *file)
{
	return __mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
}

static ssize_t auxv_read(struct file *file, char __user *buf,
			size_t count, loff_t *ppos)
{
	struct mm_struct *mm = file->private_data;
	unsigned int nwords = 0;

	if (!mm)
		return 0;
	do {
		nwords += 2;
	} while (mm->saved_auxv[nwords - 2] != 0); /* AT_NULL */
	return simple_read_from_buffer(buf, count, ppos, mm->saved_auxv,
				       nwords * sizeof(mm->saved_auxv[0]));
}

static const struct file_operations proc_auxv_operations = {
	.open		= auxv_open,
	.read		= auxv_read,
	.llseek		= generic_file_llseek,
	.release	= mem_release,
};

static ssize_t oom_adj_read(struct file *file, char __user *buf, size_t count,
			    loff_t *ppos)
{
	struct task_struct *task = get_proc_task(file_inode(file));
	char buffer[PROC_NUMBUF];
	int oom_adj = OOM_ADJUST_MIN;
	size_t len;

	if (!task)
		return -ESRCH;
	if (task->signal->oom_score_adj == OOM_SCORE_ADJ_MAX)
		oom_adj = OOM_ADJUST_MAX;
	else
		oom_adj = (task->signal->oom_score_adj * -OOM_DISABLE) /
			  OOM_SCORE_ADJ_MAX;
	put_task_struct(task);
	if (oom_adj > OOM_ADJUST_MAX)
		oom_adj = OOM_ADJUST_MAX;
	len = snprintf(buffer, sizeof(buffer), "%d\n", oom_adj);
	return simple_read_from_buffer(buf, count, ppos, buffer, len);
}

static int __set_oom_adj(struct file *file, int oom_adj, bool legacy)
{
	struct mm_struct *mm = NULL;
	struct task_struct *task;
	int err = 0;

	task = get_proc_task(file_inode(file));
	if (!task)
		return -ESRCH;

	mutex_lock(&oom_adj_mutex);
	if (legacy) {
		if (oom_adj < task->signal->oom_score_adj &&
				!capable(CAP_SYS_RESOURCE)) {
			err = -EACCES;
			goto err_unlock;
		}
		/*
		 * /proc/pid/oom_adj is provided for legacy purposes, ask users to use
		 * /proc/pid/oom_score_adj instead.
		 */
		pr_warn_once("%s (%d): /proc/%d/oom_adj is deprecated, please use /proc/%d/oom_score_adj instead.\n",
			  current->comm, task_pid_nr(current), task_pid_nr(task),
			  task_pid_nr(task));
	} else {
		if ((short)oom_adj < task->signal->oom_score_adj_min &&
				!capable(CAP_SYS_RESOURCE)) {
			err = -EACCES;
			goto err_unlock;
		}
	}

	/*
	 * Make sure we will check other processes sharing the mm if this is
	 * not vfrok which wants its own oom_score_adj.
	 * pin the mm so it doesn't go away and get reused after task_unlock
	 */
	if (!task->vfork_done) {
		struct task_struct *p = find_lock_task_mm(task);

		if (p) {
			if (test_bit(MMF_MULTIPROCESS, &p->mm->flags)) {
				mm = p->mm;
				mmgrab(mm);
			}
			task_unlock(p);
		}
	}

	task->signal->oom_score_adj = oom_adj;
	if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
		task->signal->oom_score_adj_min = (short)oom_adj;
	trace_oom_score_adj_update(task);

	if (mm) {
		struct task_struct *p;

		rcu_read_lock();
		for_each_process(p) {
			if (same_thread_group(task, p))
				continue;

			/* do not touch kernel threads or the global init */
			if (p->flags & PF_KTHREAD || is_global_init(p))
				continue;

			task_lock(p);
			if (!p->vfork_done && process_shares_mm(p, mm)) {
				p->signal->oom_score_adj = oom_adj;
				if (!legacy && has_capability_noaudit(current, CAP_SYS_RESOURCE))
					p->signal->oom_score_adj_min = (short)oom_adj;
			}
			task_unlock(p);
		}
		rcu_read_unlock();
		mmdrop(mm);
	}
err_unlock:
	mutex_unlock(&oom_adj_mutex);
	put_task_struct(task);
	return err;
}

/*
 * /proc/pid/oom_adj exists solely for backwards compatibility with previous
 * kernels.  The effective policy is defined by oom_score_adj, which has a
 * different scale: oom_adj grew exponentially and oom_score_adj grows linearly.
 * Values written to oom_adj are simply mapped linearly to oom_score_adj.
 * Processes that become oom disabled via oom_adj will still be oom disabled
 * with this implementation.
 *
 * oom_adj cannot be removed since existing userspace binaries use it.
 */
static ssize_t oom_adj_write(struct file *file, const char __user *buf,
			     size_t count, loff_t *ppos)
{
	char buffer[PROC_NUMBUF];
	int oom_adj;
	int err;

	memset(buffer, 0, sizeof(buffer));
	if (count > sizeof(buffer) - 1)
		count = sizeof(buffer) - 1;
	if (copy_from_user(buffer, buf, count)) {
		err = -EFAULT;
		goto out;
	}

	err = kstrtoint(strstrip(buffer), 0, &oom_adj);
	if (err)
		goto out;
	if ((oom_adj < OOM_ADJUST_MIN || oom_adj > OOM_ADJUST_MAX) &&
	     oom_adj != OOM_DISABLE) {
		err = -EINVAL;
		goto out;
	}

	/*
	 * Scale /proc/pid/oom_score_adj appropriately ensuring that a maximum
	 * value is always attainable.
	 */
	if (oom_adj == OOM_ADJUST_MAX)
		oom_adj = OOM_SCORE_ADJ_MAX;
	else
		oom_adj = (oom_adj * OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;

	err = __set_oom_adj(file, oom_adj, true);
out:
	return err < 0 ? err : count;
}

static const struct file_operations proc_oom_adj_operations = {
	.read		= oom_adj_read,
	.write		= oom_adj_write,
	.llseek		= generic_file_llseek,
};

static ssize_t oom_score_adj_read(struct file *file, char __user *buf,
					size_t count, loff_t *ppos)
{
	struct task_struct *task = get_proc_task(file_inode(file));
	char buffer[PROC_NUMBUF];
	short oom_score_adj = OOM_SCORE_ADJ_MIN;
	size_t len;

	if (!task)
		return -ESRCH;
	oom_score_adj = task->signal->oom_score_adj;
	put_task_struct(task);
	len = snprintf(buffer, sizeof(buffer), "%hd\n", oom_score_adj);
	return simple_read_from_buffer(buf, count, ppos, buffer, len);
}

static ssize_t oom_score_adj_write(struct file *file, const char __user *buf,
					size_t count, loff_t *ppos)
{
	char buffer[PROC_NUMBUF];
	int oom_score_adj;
	int err;

	memset(buffer, 0, sizeof(buffer));
	if (count > sizeof(buffer) - 1)
		count = sizeof(buffer) - 1;
	if (copy_from_user(buffer, buf, count)) {
		err = -EFAULT;
		goto out;
	}

	err = kstrtoint(strstrip(buffer), 0, &oom_score_adj);
	if (err)
		goto out;
	if (oom_score_adj < OOM_SCORE_ADJ_MIN ||
			oom_score_adj > OOM_SCORE_ADJ_MAX) {
		err = -EINVAL;
		goto out;
	}

	err = __set_oom_adj(file, oom_score_adj, false);
out:
	return err < 0 ? err : count;
}

static const struct file_operations proc_oom_score_adj_operations = {
	.read		= oom_score_adj_read,
	.write		= oom_score_adj_write,
	.llseek		= default_llseek,
};

#ifdef CONFIG_AUDIT
#define TMPBUFLEN 11
static ssize_t proc_loginuid_read(struct file * file, char __user * buf,
				  size_t count, loff_t *ppos)
{
	struct inode * inode = file_inode(file);
	struct task_struct *task = get_proc_task(inode);
	ssize_t length;
	char tmpbuf[TMPBUFLEN];

	if (!task)
		return -ESRCH;
	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
			   from_kuid(file->f_cred->user_ns,
				     audit_get_loginuid(task)));
	put_task_struct(task);
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}

static ssize_t proc_loginuid_write(struct file * file, const char __user * buf,
				   size_t count, loff_t *ppos)
{
	struct inode * inode = file_inode(file);
	uid_t loginuid;
	kuid_t kloginuid;
	int rv;

	/* Don't let kthreads write their own loginuid */
	if (current->flags & PF_KTHREAD)
		return -EPERM;

	rcu_read_lock();
	if (current != pid_task(proc_pid(inode), PIDTYPE_PID)) {
		rcu_read_unlock();
		return -EPERM;
	}
	rcu_read_unlock();

	if (*ppos != 0) {
		/* No partial writes. */
		return -EINVAL;
	}

	rv = kstrtou32_from_user(buf, count, 10, &loginuid);
	if (rv < 0)
		return rv;

	/* is userspace tring to explicitly UNSET the loginuid? */
	if (loginuid == AUDIT_UID_UNSET) {
		kloginuid = INVALID_UID;
	} else {
		kloginuid = make_kuid(file->f_cred->user_ns, loginuid);
		if (!uid_valid(kloginuid))
			return -EINVAL;
	}

	rv = audit_set_loginuid(kloginuid);
	if (rv < 0)
		return rv;
	return count;
}

static const struct file_operations proc_loginuid_operations = {
	.read		= proc_loginuid_read,
	.write		= proc_loginuid_write,
	.llseek		= generic_file_llseek,
};

static ssize_t proc_sessionid_read(struct file * file, char __user * buf,
				  size_t count, loff_t *ppos)
{
	struct inode * inode = file_inode(file);
	struct task_struct *task = get_proc_task(inode);
	ssize_t length;
	char tmpbuf[TMPBUFLEN];

	if (!task)
		return -ESRCH;
	length = scnprintf(tmpbuf, TMPBUFLEN, "%u",
				audit_get_sessionid(task));
	put_task_struct(task);
	return simple_read_from_buffer(buf, count, ppos, tmpbuf, length);
}

static const struct file_operations proc_sessionid_operations = {
	.read		= proc_sessionid_read,
	.llseek		= generic_file_llseek,
};
#endif

#ifdef CONFIG_FAULT_INJECTION
static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
				      size_t count, loff_t *ppos)
{
	struct task_struct *task = get_proc_task(file_inode(file));
	char buffer[PROC_NUMBUF];
	size_t len;
	int make_it_fail;

	if (!task)
		return -ESRCH;
	make_it_fail = task->make_it_fail;
	put_task_struct(task);

	len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);

	return simple_read_from_buffer(buf, count, ppos, buffer, len);
}

static ssize_t proc_fault_inject_write(struct file * file,
			const char __user * buf, size_t count, loff_t *ppos)
{
	struct task_struct *task;
	char buffer[PROC_NUMBUF];
	int make_it_fail;
	int rv;

	if (!capable(CAP_SYS_RESOURCE))
		return -EPERM;
	memset(buffer, 0, sizeof(buffer));
	if (count > sizeof(buffer) - 1)
		count = sizeof(buffer) - 1;
	if (copy_from_user(buffer, buf, count))
		return -EFAULT;
	rv = kstrtoint(strstrip(buffer), 0, &make_it_fail);
	if (rv < 0)
		return rv;
	if (make_it_fail < 0 || make_it_fail > 1)
		return -EINVAL;

	task = get_proc_task(file_inode(file));
	if (!task)
		return -ESRCH;
	task->make_it_fail = make_it_fail;
	put_task_struct(task);

	return count;
}

static const struct file_operations proc_fault_inject_operations = {
	.read		= proc_fault_inject_read,
	.write		= proc_fault_inject_write,
	.llseek		= generic_file_llseek,
};

static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf,
				   size_t count, loff_t *ppos)
{
	struct task_struct *task;
	int err;
	unsigned int n;

	err = kstrtouint_from_user(buf, count, 0, &n);
	if (err)
		return err;

	task = get_proc_task(file_inode(file));
	if (!task)
		return -ESRCH;
	task->fail_nth = n;
	put_task_struct(task);

	return count;
}

static ssize_t proc_fail_nth_read(struct file *file, char __user *buf,
				  size_t count, loff_t *ppos)
{
	struct task_struct *task;
	char numbuf[PROC_NUMBUF];
	ssize_t len;

	task = get_proc_task(file_inode(file));
	if (!task)
		return -ESRCH;
	len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth);
	put_task_struct(task);
	return simple_read_from_buffer(buf, count, ppos, numbuf, len);
}

static const struct file_operations proc_fail_nth_operations = {
	.read		= proc_fail_nth_read,
	.write		= proc_fail_nth_write,
};
#endif


#ifdef CONFIG_SCHED_DEBUG
/*
 * Print out various scheduling related per-task fields:
 */
static int sched_show(struct seq_file *m, void *v)
{
	struct inode *inode = m->private;
	struct pid_namespace *ns = proc_pid_ns(inode->i_sb);
	struct task_struct *p;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;
	proc_sched_show_task(p, ns, m);

	put_task_struct(p);

	return 0;
}

static ssize_t
sched_write(struct file *file, const char __user *buf,
	    size_t count, loff_t *offset)
{
	struct inode *inode = file_inode(file);
	struct task_struct *p;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;
	proc_sched_set_task(p);

	put_task_struct(p);

	return count;
}

static int sched_open(struct inode *inode, struct file *filp)
{
	return single_open(filp, sched_show, inode);
}

static const struct file_operations proc_pid_sched_operations = {
	.open		= sched_open,
	.read		= seq_read,
	.write		= sched_write,
	.llseek		= seq_lseek,
	.release	= single_release,
};

#endif

#ifdef CONFIG_SCHED_AUTOGROUP
/*
 * Print out autogroup related information:
 */
static int sched_autogroup_show(struct seq_file *m, void *v)
{
	struct inode *inode = m->private;
	struct task_struct *p;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;
	proc_sched_autogroup_show_task(p, m);

	put_task_struct(p);

	return 0;
}

static ssize_t
sched_autogroup_write(struct file *file, const char __user *buf,
	    size_t count, loff_t *offset)
{
	struct inode *inode = file_inode(file);
	struct task_struct *p;
	char buffer[PROC_NUMBUF];
	int nice;
	int err;

	memset(buffer, 0, sizeof(buffer));
	if (count > sizeof(buffer) - 1)
		count = sizeof(buffer) - 1;
	if (copy_from_user(buffer, buf, count))
		return -EFAULT;

	err = kstrtoint(strstrip(buffer), 0, &nice);
	if (err < 0)
		return err;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;

	err = proc_sched_autogroup_set_nice(p, nice);
	if (err)
		count = err;

	put_task_struct(p);

	return count;
}

static int sched_autogroup_open(struct inode *inode, struct file *filp)
{
	int ret;

	ret = single_open(filp, sched_autogroup_show, NULL);
	if (!ret) {
		struct seq_file *m = filp->private_data;

		m->private = inode;
	}
	return ret;
}

static const struct file_operations proc_pid_sched_autogroup_operations = {
	.open		= sched_autogroup_open,
	.read		= seq_read,
	.write		= sched_autogroup_write,
	.llseek		= seq_lseek,
	.release	= single_release,
};

#endif /* CONFIG_SCHED_AUTOGROUP */

#ifdef CONFIG_TIME_NS
static int timens_offsets_show(struct seq_file *m, void *v)
{
	struct task_struct *p;

	p = get_proc_task(file_inode(m->file));
	if (!p)
		return -ESRCH;
	proc_timens_show_offsets(p, m);

	put_task_struct(p);

	return 0;
}

static ssize_t timens_offsets_write(struct file *file, const char __user *buf,
				    size_t count, loff_t *ppos)
{
	struct inode *inode = file_inode(file);
	struct proc_timens_offset offsets[2];
	char *kbuf = NULL, *pos, *next_line;
	struct task_struct *p;
	int ret, noffsets;

	/* Only allow < page size writes at the beginning of the file */
	if ((*ppos != 0) || (count >= PAGE_SIZE))
		return -EINVAL;

	/* Slurp in the user data */
	kbuf = memdup_user_nul(buf, count);
	if (IS_ERR(kbuf))
		return PTR_ERR(kbuf);

	/* Parse the user data */
	ret = -EINVAL;
	noffsets = 0;
	for (pos = kbuf; pos; pos = next_line) {
		struct proc_timens_offset *off = &offsets[noffsets];
		char clock[10];
		int err;

		/* Find the end of line and ensure we don't look past it */
		next_line = strchr(pos, '\n');
		if (next_line) {
			*next_line = '\0';
			next_line++;
			if (*next_line == '\0')
				next_line = NULL;
		}

		err = sscanf(pos, "%9s %lld %lu", clock,
				&off->val.tv_sec, &off->val.tv_nsec);
		if (err != 3 || off->val.tv_nsec >= NSEC_PER_SEC)
			goto out;

		clock[sizeof(clock) - 1] = 0;
		if (strcmp(clock, "monotonic") == 0 ||
		    strcmp(clock, __stringify(CLOCK_MONOTONIC)) == 0)
			off->clockid = CLOCK_MONOTONIC;
		else if (strcmp(clock, "boottime") == 0 ||
			 strcmp(clock, __stringify(CLOCK_BOOTTIME)) == 0)
			off->clockid = CLOCK_BOOTTIME;
		else
			goto out;

		noffsets++;
		if (noffsets == ARRAY_SIZE(offsets)) {
			if (next_line)
				count = next_line - kbuf;
			break;
		}
	}

	ret = -ESRCH;
	p = get_proc_task(inode);
	if (!p)
		goto out;
	ret = proc_timens_set_offset(file, p, offsets, noffsets);
	put_task_struct(p);
	if (ret)
		goto out;

	ret = count;
out:
	kfree(kbuf);
	return ret;
}

static int timens_offsets_open(struct inode *inode, struct file *filp)
{
	return single_open(filp, timens_offsets_show, inode);
}

static const struct file_operations proc_timens_offsets_operations = {
	.open		= timens_offsets_open,
	.read		= seq_read,
	.write		= timens_offsets_write,
	.llseek		= seq_lseek,
	.release	= single_release,
};
#endif /* CONFIG_TIME_NS */

static ssize_t comm_write(struct file *file, const char __user *buf,
				size_t count, loff_t *offset)
{
	struct inode *inode = file_inode(file);
	struct task_struct *p;
	char buffer[TASK_COMM_LEN];
	const size_t maxlen = sizeof(buffer) - 1;

	memset(buffer, 0, sizeof(buffer));
	if (copy_from_user(buffer, buf, count > maxlen ? maxlen : count))
		return -EFAULT;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;

	if (same_thread_group(current, p)) {
		set_task_comm(p, buffer);
		proc_comm_connector(p);
	}
	else
		count = -EINVAL;

	put_task_struct(p);

	return count;
}

static int comm_show(struct seq_file *m, void *v)
{
	struct inode *inode = m->private;
	struct task_struct *p;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;

	proc_task_name(m, p, false);
	seq_putc(m, '\n');

	put_task_struct(p);

	return 0;
}

static int comm_open(struct inode *inode, struct file *filp)
{
	return single_open(filp, comm_show, inode);
}

static const struct file_operations proc_pid_set_comm_operations = {
	.open		= comm_open,
	.read		= seq_read,
	.write		= comm_write,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static int proc_exe_link(struct dentry *dentry, struct path *exe_path)
{
	struct task_struct *task;
	struct file *exe_file;

	task = get_proc_task(d_inode(dentry));
	if (!task)
		return -ENOENT;
	exe_file = get_task_exe_file(task);
	put_task_struct(task);
	if (exe_file) {
		*exe_path = exe_file->f_path;
		path_get(&exe_file->f_path);
		fput(exe_file);
		return 0;
	} else
		return -ENOENT;
}

static const char *proc_pid_get_link(struct dentry *dentry,
				     struct inode *inode,
				     struct delayed_call *done)
{
	struct path path;
	int error = -EACCES;

	if (!dentry)
		return ERR_PTR(-ECHILD);

	/* Are we allowed to snoop on the tasks file descriptors? */
	if (!proc_fd_access_allowed(inode))
		goto out;

	error = PROC_I(inode)->op.proc_get_link(dentry, &path);
	if (error)
		goto out;

	error = nd_jump_link(&path);
out:
	return ERR_PTR(error);
}

static int do_proc_readlink(const struct path *path, char __user *buffer, int buflen)
{
	char *tmp = kmalloc(PATH_MAX, GFP_KERNEL);
	char *pathname;
	int len;

	if (!tmp)
		return -ENOMEM;

	pathname = d_path(path, tmp, PATH_MAX);
	len = PTR_ERR(pathname);
	if (IS_ERR(pathname))
		goto out;
	len = tmp + PATH_MAX - 1 - pathname;

	if (len > buflen)
		len = buflen;
	if (copy_to_user(buffer, pathname, len))
		len = -EFAULT;
 out:
	kfree(tmp);
	return len;
}

static int proc_pid_readlink(struct dentry * dentry, char __user * buffer, int buflen)
{
	int error = -EACCES;
	struct inode *inode = d_inode(dentry);
	struct path path;

	/* Are we allowed to snoop on the tasks file descriptors? */
	if (!proc_fd_access_allowed(inode))
		goto out;

	error = PROC_I(inode)->op.proc_get_link(dentry, &path);
	if (error)
		goto out;

	error = do_proc_readlink(&path, buffer, buflen);
	path_put(&path);
out:
	return error;
}

const struct inode_operations proc_pid_link_inode_operations = {
	.readlink	= proc_pid_readlink,
	.get_link	= proc_pid_get_link,
	.setattr	= proc_setattr,
};


/* building an inode */

void task_dump_owner(struct task_struct *task, umode_t mode,
		     kuid_t *ruid, kgid_t *rgid)
{
	/* Depending on the state of dumpable compute who should own a
	 * proc file for a task.
	 */
	const struct cred *cred;
	kuid_t uid;
	kgid_t gid;

	if (unlikely(task->flags & PF_KTHREAD)) {
		*ruid = GLOBAL_ROOT_UID;
		*rgid = GLOBAL_ROOT_GID;
		return;
	}

	/* Default to the tasks effective ownership */
	rcu_read_lock();
	cred = __task_cred(task);
	uid = cred->euid;
	gid = cred->egid;
	rcu_read_unlock();

	/*
	 * Before the /proc/pid/status file was created the only way to read
	 * the effective uid of a /process was to stat /proc/pid.  Reading
	 * /proc/pid/status is slow enough that procps and other packages
	 * kept stating /proc/pid.  To keep the rules in /proc simple I have
	 * made this apply to all per process world readable and executable
	 * directories.
	 */
	if (mode != (S_IFDIR|S_IRUGO|S_IXUGO)) {
		struct mm_struct *mm;
		task_lock(task);
		mm = task->mm;
		/* Make non-dumpable tasks owned by some root */
		if (mm) {
			if (get_dumpable(mm) != SUID_DUMP_USER) {
				struct user_namespace *user_ns = mm->user_ns;

				uid = make_kuid(user_ns, 0);
				if (!uid_valid(uid))
					uid = GLOBAL_ROOT_UID;

				gid = make_kgid(user_ns, 0);
				if (!gid_valid(gid))
					gid = GLOBAL_ROOT_GID;
			}
		} else {
			uid = GLOBAL_ROOT_UID;
			gid = GLOBAL_ROOT_GID;
		}
		task_unlock(task);
	}
	*ruid = uid;
	*rgid = gid;
}

void proc_pid_evict_inode(struct proc_inode *ei)
{
	struct pid *pid = ei->pid;

	if (S_ISDIR(ei->vfs_inode.i_mode)) {
		spin_lock(&pid->lock);
		hlist_del_init_rcu(&ei->sibling_inodes);
		spin_unlock(&pid->lock);
	}

	put_pid(pid);
}

struct inode *proc_pid_make_inode(struct super_block *sb,
				  struct task_struct *task, umode_t mode)
{
	struct inode * inode;
	struct proc_inode *ei;
	struct pid *pid;

	/* We need a new inode */

	inode = new_inode(sb);
	if (!inode)
		goto out;

	/* Common stuff */
	ei = PROC_I(inode);
	inode->i_mode = mode;
	inode->i_ino = get_next_ino();
	inode->i_mtime = inode->i_atime = inode->i_ctime = current_time(inode);
	inode->i_op = &proc_def_inode_operations;

	/*
	 * grab the reference to task.
	 */
	pid = get_task_pid(task, PIDTYPE_PID);
	if (!pid)
		goto out_unlock;

	/* Let the pid remember us for quick removal */
	ei->pid = pid;

	task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
	security_task_to_inode(task, inode);

out:
	return inode;

out_unlock:
	iput(inode);
	return NULL;
}

/*
 * Generating an inode and adding it into @pid->inodes, so that task will
 * invalidate inode's dentry before being released.
 *
 * This helper is used for creating dir-type entries under '/proc' and
 * '/proc/<tgid>/task'. Other entries(eg. fd, stat) under '/proc/<tgid>'
 * can be released by invalidating '/proc/<tgid>' dentry.
 * In theory, dentries under '/proc/<tgid>/task' can also be released by
 * invalidating '/proc/<tgid>' dentry, we reserve it to handle single
 * thread exiting situation: Any one of threads should invalidate its
 * '/proc/<tgid>/task/<pid>' dentry before released.
 */
static struct inode *proc_pid_make_base_inode(struct super_block *sb,
				struct task_struct *task, umode_t mode)
{
	struct inode *inode;
	struct proc_inode *ei;
	struct pid *pid;

	inode = proc_pid_make_inode(sb, task, mode);
	if (!inode)
		return NULL;

	/* Let proc_flush_pid find this directory inode */
	ei = PROC_I(inode);
	pid = ei->pid;
	spin_lock(&pid->lock);
	hlist_add_head_rcu(&ei->sibling_inodes, &pid->inodes);
	spin_unlock(&pid->lock);

	return inode;
}

int pid_getattr(struct user_namespace *mnt_userns, const struct path *path,
		struct kstat *stat, u32 request_mask, unsigned int query_flags)
{
	struct inode *inode = d_inode(path->dentry);
	struct proc_fs_info *fs_info = proc_sb_info(inode->i_sb);
	struct task_struct *task;

	generic_fillattr(&init_user_ns, inode, stat);

	stat->uid = GLOBAL_ROOT_UID;
	stat->gid = GLOBAL_ROOT_GID;
	rcu_read_lock();
	task = pid_task(proc_pid(inode), PIDTYPE_PID);
	if (task) {
		if (!has_pid_permissions(fs_info, task, HIDEPID_INVISIBLE)) {
			rcu_read_unlock();
			/*
			 * This doesn't prevent learning whether PID exists,
			 * it only makes getattr() consistent with readdir().
			 */
			return -ENOENT;
		}
		task_dump_owner(task, inode->i_mode, &stat->uid, &stat->gid);
	}
	rcu_read_unlock();
	return 0;
}

/* dentry stuff */

/*
 * Set <pid>/... inode ownership (can change due to setuid(), etc.)
 */
void pid_update_inode(struct task_struct *task, struct inode *inode)
{
	task_dump_owner(task, inode->i_mode, &inode->i_uid, &inode->i_gid);

	inode->i_mode &= ~(S_ISUID | S_ISGID);
	security_task_to_inode(task, inode);
}

/*
 * Rewrite the inode's ownerships here because the owning task may have
 * performed a setuid(), etc.
 *
 */
static int pid_revalidate(struct dentry *dentry, unsigned int flags)
{
	struct inode *inode;
	struct task_struct *task;
	int ret = 0;

	rcu_read_lock();
	inode = d_inode_rcu(dentry);
	if (!inode)
		goto out;
	task = pid_task(proc_pid(inode), PIDTYPE_PID);

	if (task) {
		pid_update_inode(task, inode);
		ret = 1;
	}
out:
	rcu_read_unlock();
	return ret;
}

static inline bool proc_inode_is_dead(struct inode *inode)
{
	return !proc_pid(inode)->tasks[PIDTYPE_PID].first;
}

int pid_delete_dentry(const struct dentry *dentry)
{
	/* Is the task we represent dead?
	 * If so, then don't put the dentry on the lru list,
	 * kill it immediately.
	 */
	return proc_inode_is_dead(d_inode(dentry));
}

const struct dentry_operations pid_dentry_operations =
{
	.d_revalidate	= pid_revalidate,
	.d_delete	= pid_delete_dentry,
};

/* Lookups */

/*
 * Fill a directory entry.
 *
 * If possible create the dcache entry and derive our inode number and
 * file type from dcache entry.
 *
 * Since all of the proc inode numbers are dynamically generated, the inode
 * numbers do not exist until the inode is cache.  This means creating
 * the dcache entry in readdir is necessary to keep the inode numbers
 * reported by readdir in sync with the inode numbers reported
 * by stat.
 */
bool proc_fill_cache(struct file *file, struct dir_context *ctx,
	const char *name, unsigned int len,
	instantiate_t instantiate, struct task_struct *task, const void *ptr)
{
	struct dentry *child, *dir = file->f_path.dentry;
	struct qstr qname = QSTR_INIT(name, len);
	struct inode *inode;
	unsigned type = DT_UNKNOWN;
	ino_t ino = 1;

	child = d_hash_and_lookup(dir, &qname);
	if (!child) {
		DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
		child = d_alloc_parallel(dir, &qname, &wq);
		if (IS_ERR(child))
			goto end_instantiate;
		if (d_in_lookup(child)) {
			struct dentry *res;
			res = instantiate(child, task, ptr);
			d_lookup_done(child);
			if (unlikely(res)) {
				dput(child);
				child = res;
				if (IS_ERR(child))
					goto end_instantiate;
			}
		}
	}
	inode = d_inode(child);
	ino = inode->i_ino;
	type = inode->i_mode >> 12;
	dput(child);
end_instantiate:
	return dir_emit(ctx, name, len, ino, type);
}

/*
 * dname_to_vma_addr - maps a dentry name into two unsigned longs
 * which represent vma start and end addresses.
 */
static int dname_to_vma_addr(struct dentry *dentry,
			     unsigned long *start, unsigned long *end)
{
	const char *str = dentry->d_name.name;
	unsigned long long sval, eval;
	unsigned int len;

	if (str[0] == '0' && str[1] != '-')
		return -EINVAL;
	len = _parse_integer(str, 16, &sval);
	if (len & KSTRTOX_OVERFLOW)
		return -EINVAL;
	if (sval != (unsigned long)sval)
		return -EINVAL;
	str += len;

	if (*str != '-')
		return -EINVAL;
	str++;

	if (str[0] == '0' && str[1])
		return -EINVAL;
	len = _parse_integer(str, 16, &eval);
	if (len & KSTRTOX_OVERFLOW)
		return -EINVAL;
	if (eval != (unsigned long)eval)
		return -EINVAL;
	str += len;

	if (*str != '\0')
		return -EINVAL;

	*start = sval;
	*end = eval;

	return 0;
}

static int map_files_d_revalidate(struct dentry *dentry, unsigned int flags)
{
	unsigned long vm_start, vm_end;
	bool exact_vma_exists = false;
	struct mm_struct *mm = NULL;
	struct task_struct *task;
	struct inode *inode;
	int status = 0;

	if (flags & LOOKUP_RCU)
		return -ECHILD;

	inode = d_inode(dentry);
	task = get_proc_task(inode);
	if (!task)
		goto out_notask;

	mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
	if (IS_ERR_OR_NULL(mm))
		goto out;

	if (!dname_to_vma_addr(dentry, &vm_start, &vm_end)) {
		status = mmap_read_lock_killable(mm);
		if (!status) {
			exact_vma_exists = !!find_exact_vma(mm, vm_start,
							    vm_end);
			mmap_read_unlock(mm);
		}
	}

	mmput(mm);

	if (exact_vma_exists) {
		task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);

		security_task_to_inode(task, inode);
		status = 1;
	}

out:
	put_task_struct(task);

out_notask:
	return status;
}

static const struct dentry_operations tid_map_files_dentry_operations = {
	.d_revalidate	= map_files_d_revalidate,
	.d_delete	= pid_delete_dentry,
};

static int map_files_get_link(struct dentry *dentry, struct path *path)
{
	unsigned long vm_start, vm_end;
	struct vm_area_struct *vma;
	struct task_struct *task;
	struct mm_struct *mm;
	int rc;

	rc = -ENOENT;
	task = get_proc_task(d_inode(dentry));
	if (!task)
		goto out;

	mm = get_task_mm(task);
	put_task_struct(task);
	if (!mm)
		goto out;

	rc = dname_to_vma_addr(dentry, &vm_start, &vm_end);
	if (rc)
		goto out_mmput;

	rc = mmap_read_lock_killable(mm);
	if (rc)
		goto out_mmput;

	rc = -ENOENT;
	vma = find_exact_vma(mm, vm_start, vm_end);
	if (vma && vma->vm_file) {
		*path = vma->vm_file->f_path;
		path_get(path);
		rc = 0;
	}
	mmap_read_unlock(mm);

out_mmput:
	mmput(mm);
out:
	return rc;
}

struct map_files_info {
	unsigned long	start;
	unsigned long	end;
	fmode_t		mode;
};

/*
 * Only allow CAP_SYS_ADMIN and CAP_CHECKPOINT_RESTORE to follow the links, due
 * to concerns about how the symlinks may be used to bypass permissions on
 * ancestor directories in the path to the file in question.
 */
static const char *
proc_map_files_get_link(struct dentry *dentry,
			struct inode *inode,
		        struct delayed_call *done)
{
	if (!checkpoint_restore_ns_capable(&init_user_ns))
		return ERR_PTR(-EPERM);

	return proc_pid_get_link(dentry, inode, done);
}

/*
 * Identical to proc_pid_link_inode_operations except for get_link()
 */
static const struct inode_operations proc_map_files_link_inode_operations = {
	.readlink	= proc_pid_readlink,
	.get_link	= proc_map_files_get_link,
	.setattr	= proc_setattr,
};

static struct dentry *
proc_map_files_instantiate(struct dentry *dentry,
			   struct task_struct *task, const void *ptr)
{
	fmode_t mode = (fmode_t)(unsigned long)ptr;
	struct proc_inode *ei;
	struct inode *inode;

	inode = proc_pid_make_inode(dentry->d_sb, task, S_IFLNK |
				    ((mode & FMODE_READ ) ? S_IRUSR : 0) |
				    ((mode & FMODE_WRITE) ? S_IWUSR : 0));
	if (!inode)
		return ERR_PTR(-ENOENT);

	ei = PROC_I(inode);
	ei->op.proc_get_link = map_files_get_link;

	inode->i_op = &proc_map_files_link_inode_operations;
	inode->i_size = 64;

	d_set_d_op(dentry, &tid_map_files_dentry_operations);
	return d_splice_alias(inode, dentry);
}

static struct dentry *proc_map_files_lookup(struct inode *dir,
		struct dentry *dentry, unsigned int flags)
{
	unsigned long vm_start, vm_end;
	struct vm_area_struct *vma;
	struct task_struct *task;
	struct dentry *result;
	struct mm_struct *mm;

	result = ERR_PTR(-ENOENT);
	task = get_proc_task(dir);
	if (!task)
		goto out;

	result = ERR_PTR(-EACCES);
	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
		goto out_put_task;

	result = ERR_PTR(-ENOENT);
	if (dname_to_vma_addr(dentry, &vm_start, &vm_end))
		goto out_put_task;

	mm = get_task_mm(task);
	if (!mm)
		goto out_put_task;

	result = ERR_PTR(-EINTR);
	if (mmap_read_lock_killable(mm))
		goto out_put_mm;

	result = ERR_PTR(-ENOENT);
	vma = find_exact_vma(mm, vm_start, vm_end);
	if (!vma)
		goto out_no_vma;

	if (vma->vm_file)
		result = proc_map_files_instantiate(dentry, task,
				(void *)(unsigned long)vma->vm_file->f_mode);

out_no_vma:
	mmap_read_unlock(mm);
out_put_mm:
	mmput(mm);
out_put_task:
	put_task_struct(task);
out:
	return result;
}

static const struct inode_operations proc_map_files_inode_operations = {
	.lookup		= proc_map_files_lookup,
	.permission	= proc_fd_permission,
	.setattr	= proc_setattr,
};

static int
proc_map_files_readdir(struct file *file, struct dir_context *ctx)
{
	struct vm_area_struct *vma;
	struct task_struct *task;
	struct mm_struct *mm;
	unsigned long nr_files, pos, i;
	GENRADIX(struct map_files_info) fa;
	struct map_files_info *p;
	int ret;
	struct vma_iterator vmi;

	genradix_init(&fa);

	ret = -ENOENT;
	task = get_proc_task(file_inode(file));
	if (!task)
		goto out;

	ret = -EACCES;
	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS))
		goto out_put_task;

	ret = 0;
	if (!dir_emit_dots(file, ctx))
		goto out_put_task;

	mm = get_task_mm(task);
	if (!mm)
		goto out_put_task;

	ret = mmap_read_lock_killable(mm);
	if (ret) {
		mmput(mm);
		goto out_put_task;
	}

	nr_files = 0;

	/*
	 * We need two passes here:
	 *
	 *  1) Collect vmas of mapped files with mmap_lock taken
	 *  2) Release mmap_lock and instantiate entries
	 *
	 * otherwise we get lockdep complained, since filldir()
	 * routine might require mmap_lock taken in might_fault().
	 */

	pos = 2;
	vma_iter_init(&vmi, mm, 0);
	for_each_vma(vmi, vma) {
		if (!vma->vm_file)
			continue;
		if (++pos <= ctx->pos)
			continue;

		p = genradix_ptr_alloc(&fa, nr_files++, GFP_KERNEL);
		if (!p) {
			ret = -ENOMEM;
			mmap_read_unlock(mm);
			mmput(mm);
			goto out_put_task;
		}

		p->start = vma->vm_start;
		p->end = vma->vm_end;
		p->mode = vma->vm_file->f_mode;
	}
	mmap_read_unlock(mm);
	mmput(mm);

	for (i = 0; i < nr_files; i++) {
		char buf[4 * sizeof(long) + 2];	/* max: %lx-%lx\0 */
		unsigned int len;

		p = genradix_ptr(&fa, i);
		len = snprintf(buf, sizeof(buf), "%lx-%lx", p->start, p->end);
		if (!proc_fill_cache(file, ctx,
				      buf, len,
				      proc_map_files_instantiate,
				      task,
				      (void *)(unsigned long)p->mode))
			break;
		ctx->pos++;
	}

out_put_task:
	put_task_struct(task);
out:
	genradix_free(&fa);
	return ret;
}

static const struct file_operations proc_map_files_operations = {
	.read		= generic_read_dir,
	.iterate_shared	= proc_map_files_readdir,
	.llseek		= generic_file_llseek,
};

#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
struct timers_private {
	struct pid *pid;
	struct task_struct *task;
	struct sighand_struct *sighand;
	struct pid_namespace *ns;
	unsigned long flags;
};

static void *timers_start(struct seq_file *m, loff_t *pos)
{
	struct timers_private *tp = m->private;

	tp->task = get_pid_task(tp->pid, PIDTYPE_PID);
	if (!tp->task)
		return ERR_PTR(-ESRCH);

	tp->sighand = lock_task_sighand(tp->task, &tp->flags);
	if (!tp->sighand)
		return ERR_PTR(-ESRCH);

	return seq_list_start(&tp->task->signal->posix_timers, *pos);
}

static void *timers_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct timers_private *tp = m->private;
	return seq_list_next(v, &tp->task->signal->posix_timers, pos);
}

static void timers_stop(struct seq_file *m, void *v)
{
	struct timers_private *tp = m->private;

	if (tp->sighand) {
		unlock_task_sighand(tp->task, &tp->flags);
		tp->sighand = NULL;
	}

	if (tp->task) {
		put_task_struct(tp->task);
		tp->task = NULL;
	}
}

static int show_timer(struct seq_file *m, void *v)
{
	struct k_itimer *timer;
	struct timers_private *tp = m->private;
	int notify;
	static const char * const nstr[] = {
		[SIGEV_SIGNAL] = "signal",
		[SIGEV_NONE] = "none",
		[SIGEV_THREAD] = "thread",
	};

	timer = list_entry((struct list_head *)v, struct k_itimer, list);
	notify = timer->it_sigev_notify;

	seq_printf(m, "ID: %d\n", timer->it_id);
	seq_printf(m, "signal: %d/%px\n",
		   timer->sigq->info.si_signo,
		   timer->sigq->info.si_value.sival_ptr);
	seq_printf(m, "notify: %s/%s.%d\n",
		   nstr[notify & ~SIGEV_THREAD_ID],
		   (notify & SIGEV_THREAD_ID) ? "tid" : "pid",
		   pid_nr_ns(timer->it_pid, tp->ns));
	seq_printf(m, "ClockID: %d\n", timer->it_clock);

	return 0;
}

static const struct seq_operations proc_timers_seq_ops = {
	.start	= timers_start,
	.next	= timers_next,
	.stop	= timers_stop,
	.show	= show_timer,
};

static int proc_timers_open(struct inode *inode, struct file *file)
{
	struct timers_private *tp;

	tp = __seq_open_private(file, &proc_timers_seq_ops,
			sizeof(struct timers_private));
	if (!tp)
		return -ENOMEM;

	tp->pid = proc_pid(inode);
	tp->ns = proc_pid_ns(inode->i_sb);
	return 0;
}

static const struct file_operations proc_timers_operations = {
	.open		= proc_timers_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release_private,
};
#endif

static ssize_t timerslack_ns_write(struct file *file, const char __user *buf,
					size_t count, loff_t *offset)
{
	struct inode *inode = file_inode(file);
	struct task_struct *p;
	u64 slack_ns;
	int err;

	err = kstrtoull_from_user(buf, count, 10, &slack_ns);
	if (err < 0)
		return err;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;

	if (p != current) {
		rcu_read_lock();
		if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
			rcu_read_unlock();
			count = -EPERM;
			goto out;
		}
		rcu_read_unlock();

		err = security_task_setscheduler(p);
		if (err) {
			count = err;
			goto out;
		}
	}

	task_lock(p);
	if (slack_ns == 0)
		p->timer_slack_ns = p->default_timer_slack_ns;
	else
		p->timer_slack_ns = slack_ns;
	task_unlock(p);

out:
	put_task_struct(p);

	return count;
}

static int timerslack_ns_show(struct seq_file *m, void *v)
{
	struct inode *inode = m->private;
	struct task_struct *p;
	int err = 0;

	p = get_proc_task(inode);
	if (!p)
		return -ESRCH;

	if (p != current) {
		rcu_read_lock();
		if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) {
			rcu_read_unlock();
			err = -EPERM;
			goto out;
		}
		rcu_read_unlock();

		err = security_task_getscheduler(p);
		if (err)
			goto out;
	}

	task_lock(p);
	seq_printf(m, "%llu\n", p->timer_slack_ns);
	task_unlock(p);

out:
	put_task_struct(p);

	return err;
}

static int timerslack_ns_open(struct inode *inode, struct file *filp)
{
	return single_open(filp, timerslack_ns_show, inode);
}

static const struct file_operations proc_pid_set_timerslack_ns_operations = {
	.open		= timerslack_ns_open,
	.read		= seq_read,
	.write		= timerslack_ns_write,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static struct dentry *proc_pident_instantiate(struct dentry *dentry,
	struct task_struct *task, const void *ptr)
{
	const struct pid_entry *p = ptr;
	struct inode *inode;
	struct proc_inode *ei;

	inode = proc_pid_make_inode(dentry->d_sb, task, p->mode);
	if (!inode)
		return ERR_PTR(-ENOENT);

	ei = PROC_I(inode);
	if (S_ISDIR(inode->i_mode))
		set_nlink(inode, 2);	/* Use getattr to fix if necessary */
	if (p->iop)
		inode->i_op = p->iop;
	if (p->fop)
		inode->i_fop = p->fop;
	ei->op = p->op;
	pid_update_inode(task, inode);
	d_set_d_op(dentry, &pid_dentry_operations);
	return d_splice_alias(inode, dentry);
}

static struct dentry *proc_pident_lookup(struct inode *dir, 
					 struct dentry *dentry,
					 const struct pid_entry *p,
					 const struct pid_entry *end)
{
	struct task_struct *task = get_proc_task(dir);
	struct dentry *res = ERR_PTR(-ENOENT);

	if (!task)
		goto out_no_task;

	/*
	 * Yes, it does not scale. And it should not. Don't add
	 * new entries into /proc/<tgid>/ without very good reasons.
	 */
	for (; p < end; p++) {
		if (p->len != dentry->d_name.len)
			continue;
		if (!memcmp(dentry->d_name.name, p->name, p->len)) {
			res = proc_pident_instantiate(dentry, task, p);
			break;
		}
	}
	put_task_struct(task);
out_no_task:
	return res;
}

static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
		const struct pid_entry *ents, unsigned int nents)
{
	struct task_struct *task = get_proc_task(file_inode(file));
	const struct pid_entry *p;

	if (!task)
		return -ENOENT;

	if (!dir_emit_dots(file, ctx))
		goto out;

	if (ctx->pos >= nents + 2)
		goto out;

	for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
		if (!proc_fill_cache(file, ctx, p->name, p->len,
				proc_pident_instantiate, task, p))
			break;
		ctx->pos++;
	}
out:
	put_task_struct(task);
	return 0;
}

#ifdef CONFIG_SECURITY
static int proc_pid_attr_open(struct inode *inode, struct file *file)
{
	file->private_data = NULL;
	__mem_open(inode, file, PTRACE_MODE_READ_FSCREDS);
	return 0;
}

static ssize_t proc_pid_attr_read(struct file * file, char __user * buf,
				  size_t count, loff_t *ppos)
{
	struct inode * inode = file_inode(file);
	char *p = NULL;
	ssize_t length;
	struct task_struct *task = get_proc_task(inode);

	if (!task)
		return -ESRCH;

	length = security_getprocattr(task, PROC_I(inode)->op.lsm,
				      file->f_path.dentry->d_name.name,
				      &p);
	put_task_struct(task);
	if (length > 0)
		length = simple_read_from_buffer(buf, count, ppos, p, length);
	kfree(p);
	return length;
}

static ssize_t proc_pid_attr_write(struct file * file, const char __user * buf,
				   size_t count, loff_t *ppos)
{
	struct inode * inode = file_inode(file);
	struct task_struct *task;
	void *page;
	int rv;

	/* A task may only write when it was the opener. */
	if (file->private_data != current->mm)
		return -EPERM;

	rcu_read_lock();
	task = pid_task(proc_pid(inode), PIDTYPE_PID);
	if (!task) {
		rcu_read_unlock();
		return -ESRCH;
	}
	/* A task may only write its own attributes. */
	if (current != task) {
		rcu_read_unlock();
		return -EACCES;
	}
	/* Prevent changes to overridden credentials. */
	if (current_cred() != current_real_cred()) {
		rcu_read_unlock();
		return -EBUSY;
	}
	rcu_read_unlock();

	if (count > PAGE_SIZE)
		count = PAGE_SIZE;

	/* No partial writes. */
	if (*ppos != 0)
		return -EINVAL;

	page = memdup_user(buf, count);
	if (IS_ERR(page)) {
		rv = PTR_ERR(page);
		goto out;
	}

	/* Guard against adverse ptrace interaction */
	rv = mutex_lock_interruptible(&current->signal->cred_guard_mutex);
	if (rv < 0)
		goto out_free;

	rv = security_setprocattr(PROC_I(inode)->op.lsm,
				  file->f_path.dentry->d_name.name, page,
				  count);
	mutex_unlock(&current->signal->cred_guard_mutex);
out_free:
	kfree(page);
out:
	return rv;
}

static const struct file_operations proc_pid_attr_operations = {
	.open		= proc_pid_attr_open,
	.read		= proc_pid_attr_read,
	.write		= proc_pid_attr_write,
	.llseek		= generic_file_llseek,
	.release	= mem_release,
};

#define LSM_DIR_OPS(LSM) \
static int proc_##LSM##_attr_dir_iterate(struct file *filp, \
			     struct dir_context *ctx) \
{ \
	return proc_pident_readdir(filp, ctx, \
				   LSM##_attr_dir_stuff, \
				   ARRAY_SIZE(LSM##_attr_dir_stuff)); \
} \
\
static const struct file_operations proc_##LSM##_attr_dir_ops = { \
	.read		= generic_read_dir, \
	.iterate	= proc_##LSM##_attr_dir_iterate, \
	.llseek		= default_llseek, \
}; \
\
static struct dentry *proc_##LSM##_attr_dir_lookup(struct inode *dir, \
				struct dentry *dentry, unsigned int flags) \
{ \
	return proc_pident_lookup(dir, dentry, \
				  LSM##_attr_dir_stuff, \
				  LSM##_attr_dir_stuff + ARRAY_SIZE(LSM##_attr_dir_stuff)); \
} \
\
static const struct inode_operations proc_##LSM##_attr_dir_inode_ops = { \
	.lookup		= proc_##LSM##_attr_dir_lookup, \
	.getattr	= pid_getattr, \
	.setattr	= proc_setattr, \
}

#ifdef CONFIG_SECURITY_SMACK
static const struct pid_entry smack_attr_dir_stuff[] = {
	ATTR("smack", "current",	0666),
};
LSM_DIR_OPS(smack);
#endif

#ifdef CONFIG_SECURITY_APPARMOR
static const struct pid_entry apparmor_attr_dir_stuff[] = {
	ATTR("apparmor", "current",	0666),
	ATTR("apparmor", "prev",	0444),
	ATTR("apparmor", "exec",	0666),
};
LSM_DIR_OPS(apparmor);
#endif

static const struct pid_entry attr_dir_stuff[] = {
	ATTR(NULL, "current",		0666),
	ATTR(NULL, "prev",		0444),
	ATTR(NULL, "exec",		0666),
	ATTR(NULL, "fscreate",		0666),
	ATTR(NULL, "keycreate",		0666),
	ATTR(NULL, "sockcreate",	0666),
#ifdef CONFIG_SECURITY_SMACK
	DIR("smack",			0555,
	    proc_smack_attr_dir_inode_ops, proc_smack_attr_dir_ops),
#endif
#ifdef CONFIG_SECURITY_APPARMOR
	DIR("apparmor",			0555,
	    proc_apparmor_attr_dir_inode_ops, proc_apparmor_attr_dir_ops),
#endif
};

static int proc_attr_dir_readdir(struct file *file, struct dir_context *ctx)
{
	return proc_pident_readdir(file, ctx, 
				   attr_dir_stuff, ARRAY_SIZE(attr_dir_stuff));
}

static const struct file_operations proc_attr_dir_operations = {
	.read		= generic_read_dir,
	.iterate_shared	= proc_attr_dir_readdir,
	.llseek		= generic_file_llseek,
};

static struct dentry *proc_attr_dir_lookup(struct inode *dir,
				struct dentry *dentry, unsigned int flags)
{
	return proc_pident_lookup(dir, dentry,
				  attr_dir_stuff,
				  attr_dir_stuff + ARRAY_SIZE(attr_dir_stuff));
}

static const struct inode_operations proc_attr_dir_inode_operations = {
	.lookup		= proc_attr_dir_lookup,
	.getattr	= pid_getattr,
	.setattr	= proc_setattr,
};

#endif

#ifdef CONFIG_ELF_CORE
static ssize_t proc_coredump_filter_read(struct file *file, char __user *buf,
					 size_t count, loff_t *ppos)
{
	struct task_struct *task = get_proc_task(file_inode(file));
	struct mm_struct *mm;
	char buffer[PROC_NUMBUF];
	size_t len;
	int ret;

	if (!task)
		return -ESRCH;

	ret = 0;
	mm = get_task_mm(task);
	if (mm) {
		len = snprintf(buffer, sizeof(buffer), "%08lx\n",
			       ((mm->flags & MMF_DUMP_FILTER_MASK) >>
				MMF_DUMP_FILTER_SHIFT));
		mmput(mm);
		ret = simple_read_from_buffer(buf, count, ppos, buffer, len);
	}

	put_task_struct(task);

	return ret;
}

static ssize_t proc_coredump_filter_write(struct file *file,
					  const char __user *buf,
					  size_t count,
					  loff_t *ppos)
{
	struct task_struct *task;
	struct mm_struct *mm;
	unsigned int val;
	int ret;
	int i;
	unsigned long mask;

	ret = kstrtouint_from_user(buf, count, 0, &val);
	if (ret < 0)
		return ret;

	ret = -ESRCH;
	task = get_proc_task(file_inode(file));
	if (!task)
		goto out_no_task;

	mm = get_task_mm(task);
	if (!mm)
		goto out_no_mm;
	ret = 0;

	for (i = 0, mask = 1; i < MMF_DUMP_FILTER_BITS; i++, mask <<= 1) {
		if (val & mask)
			set_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
		else
			clear_bit(i + MMF_DUMP_FILTER_SHIFT, &mm->flags);
	}

	mmput(mm);
 out_no_mm:
	put_task_struct(task);
 out_no_task:
	if (ret < 0)
		return ret;
	return count;
}

static const struct file_operations proc_coredump_filter_operations = {
	.read		= proc_coredump_filter_read,
	.write		= proc_coredump_filter_write,
	.llseek		= generic_file_llseek,
};
#endif

#ifdef CONFIG_TASK_IO_ACCOUNTING
static int do_io_accounting(struct task_struct *task, struct seq_file *m, int whole)
{
	struct task_io_accounting acct = task->ioac;
	unsigned long flags;
	int result;

	result = down_read_killable(&task->signal->exec_update_lock);
	if (result)
		return result;

	if (!ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS)) {
		result = -EACCES;
		goto out_unlock;
	}

	if (whole && lock_task_sighand(task, &flags)) {
		struct task_struct *t = task;

		task_io_accounting_add(&acct, &task->signal->ioac);
		while_each_thread(task, t)
			task_io_accounting_add(&acct, &t->ioac);

		unlock_task_sighand(task, &flags);
	}
	seq_printf(m,
		   "rchar: %llu\n"
		   "wchar: %llu\n"
		   "syscr: %llu\n"
		   "syscw: %llu\n"
		   "read_bytes: %llu\n"
		   "write_bytes: %llu\n"
		   "cancelled_write_bytes: %llu\n",
		   (unsigned long long)acct.rchar,
		   (unsigned long long)acct.wchar,
		   (unsigned long long)acct.syscr,
		   (unsigned long long)acct.syscw,
		   (unsigned long long)acct.read_bytes,
		   (unsigned long long)acct.write_bytes,
		   (unsigned long long)acct.cancelled_write_bytes);
	result = 0;

out_unlock:
	up_read(&task->signal->exec_update_lock);
	return result;
}

static int proc_tid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
				  struct pid *pid, struct task_struct *task)
{
	return do_io_accounting(task, m, 0);
}

static int proc_tgid_io_accounting(struct seq_file *m, struct pid_namespace *ns,
				   struct pid *pid, struct task_struct *task)
{
	return do_io_accounting(task, m, 1);
}
#endif /* CONFIG_TASK_IO_ACCOUNTING */

#ifdef CONFIG_USER_NS
static int proc_id_map_open(struct inode *inode, struct file *file,
	const struct seq_operations *seq_ops)
{
	struct user_namespace *ns = NULL;
	struct task_struct *task;
	struct seq_file *seq;
	int ret = -EINVAL;

	task = get_proc_task(inode);
	if (task) {
		rcu_read_lock();
		ns = get_user_ns(task_cred_xxx(task, user_ns));
		rcu_read_unlock();
		put_task_struct(task);
	}
	if (!ns)
		goto err;

	ret = seq_open(file, seq_ops);
	if (ret)
		goto err_put_ns;

	seq = file->private_data;
	seq->private = ns;

	return 0;
err_put_ns:
	put_user_ns(ns);
err:
	return ret;
}

static int proc_id_map_release(struct inode *inode, struct file *file)
{
	struct seq_file *seq = file->private_data;
	struct user_namespace *ns = seq->private;
	put_user_ns(ns);
	return seq_release(inode, file);
}

static int proc_uid_map_open(struct inode *inode, struct file *file)
{
	return proc_id_map_open(inode, file, &proc_uid_seq_operations);
}

static int proc_gid_map_open(struct inode *inode, struct file *file)
{
	return proc_id_map_open(inode, file, &proc_gid_seq_operations);
}

static int proc_projid_map_open(struct inode *inode, struct file *file)
{
	return proc_id_map_open(inode, file, &proc_projid_seq_operations);
}

static const struct file_operations proc_uid_map_operations = {
	.open		= proc_uid_map_open,
	.write		= proc_uid_map_write,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= proc_id_map_release,
};

static const struct file_operations proc_gid_map_operations = {
	.open		= proc_gid_map_open,
	.write		= proc_gid_map_write,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= proc_id_map_release,
};

static const struct file_operations proc_projid_map_operations = {
	.open		= proc_projid_map_open,
	.write		= proc_projid_map_write,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= proc_id_map_release,
};

static int proc_setgroups_open(struct inode *inode, struct file *file)
{
	struct user_namespace *ns = NULL;
	struct task_struct *task;
	int ret;

	ret = -ESRCH;
	task = get_proc_task(inode);
	if (task) {
		rcu_read_lock();
		ns = get_user_ns(task_cred_xxx(task, user_ns));
		rcu_read_unlock();
		put_task_struct(task);
	}
	if (!ns)
		goto err;

	if (file->f_mode & FMODE_WRITE) {
		ret = -EACCES;
		if (!ns_capable(ns, CAP_SYS_ADMIN))
			goto err_put_ns;
	}

	ret = single_open(file, &proc_setgroups_show, ns);
	if (ret)
		goto err_put_ns;

	return 0;
err_put_ns:
	put_user_ns(ns);
err:
	return ret;
}

static int proc_setgroups_release(struct inode *inode, struct file *file)
{
	struct seq_file *seq = file->private_data;
	struct user_namespace *ns = seq->private;
	int ret = single_release(inode, file);
	put_user_ns(ns);
	return ret;
}

static const struct file_operations proc_setgroups_operations = {
	.open		= proc_setgroups_open,
	.write		= proc_setgroups_write,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= proc_setgroups_release,
};
#endif /* CONFIG_USER_NS */

static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
				struct pid *pid, struct task_struct *task)
{
	int err = lock_trace(task);
	if (!err) {
		seq_printf(m, "%08x\n", task->personality);
		unlock_trace(task);
	}
	return err;
}

#ifdef CONFIG_LIVEPATCH
static int proc_pid_patch_state(struct seq_file *m, struct pid_namespace *ns,
				struct pid *pid, struct task_struct *task)
{
	seq_printf(m, "%d\n", task->patch_state);
	return 0;
}
#endif /* CONFIG_LIVEPATCH */

#ifdef CONFIG_KSM
static int proc_pid_ksm_merging_pages(struct seq_file *m, struct pid_namespace *ns,
				struct pid *pid, struct task_struct *task)
{
	struct mm_struct *mm;

	mm = get_task_mm(task);
	if (mm) {
		seq_printf(m, "%lu\n", mm->ksm_merging_pages);
		mmput(mm);
	}

	return 0;
}
static int proc_pid_ksm_stat(struct seq_file *m, struct pid_namespace *ns,
				struct pid *pid, struct task_struct *task)
{
	struct mm_struct *mm;

	mm = get_task_mm(task);
	if (mm) {
		seq_printf(m, "ksm_rmap_items %lu\n", mm->ksm_rmap_items);
		mmput(mm);
	}

	return 0;
}
#endif /* CONFIG_KSM */

#ifdef CONFIG_STACKLEAK_METRICS
static int proc_stack_depth(struct seq_file *m, struct pid_namespace *ns,
				struct pid *pid, struct task_struct *task)
{
	unsigned long prev_depth = THREAD_SIZE -
				(task->prev_lowest_stack & (THREAD_SIZE - 1));
	unsigned long depth = THREAD_SIZE -
				(task->lowest_stack & (THREAD_SIZE - 1));

	seq_printf(m, "previous stack depth: %lu\nstack depth: %lu\n",
							prev_depth, depth);
	return 0;
}
#endif /* CONFIG_STACKLEAK_METRICS */

/*
 * Thread groups
 */
static const struct file_operations proc_task_operations;
static const struct inode_operations proc_task_inode_operations;

static const struct pid_entry tgid_base_stuff[] = {
	DIR("task",       S_IRUGO|S_IXUGO, proc_task_inode_operations, proc_task_operations),
	DIR("fd",         S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
	DIR("map_files",  S_IRUSR|S_IXUSR, proc_map_files_inode_operations, proc_map_files_operations),
	DIR("fdinfo",     S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
	DIR("ns",	  S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
#ifdef CONFIG_NET
	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
#endif
	REG("environ",    S_IRUSR, proc_environ_operations),
	REG("auxv",       S_IRUSR, proc_auxv_operations),
	ONE("status",     S_IRUGO, proc_pid_status),
	ONE("personality", S_IRUSR, proc_pid_personality),
	ONE("limits",	  S_IRUGO, proc_pid_limits),
#ifdef CONFIG_SCHED_DEBUG
	REG("sched",      S_IRUGO|S_IWUSR, proc_pid_sched_operations),
#endif
#ifdef CONFIG_SCHED_AUTOGROUP
	REG("autogroup",  S_IRUGO|S_IWUSR, proc_pid_sched_autogroup_operations),
#endif
#ifdef CONFIG_TIME_NS
	REG("timens_offsets",  S_IRUGO|S_IWUSR, proc_timens_offsets_operations),
#endif
	REG("comm",      S_IRUGO|S_IWUSR, proc_pid_set_comm_operations),
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
	ONE("syscall",    S_IRUSR, proc_pid_syscall),
#endif
	REG("cmdline",    S_IRUGO, proc_pid_cmdline_ops),
	ONE("stat",       S_IRUGO, proc_tgid_stat),
	ONE("statm",      S_IRUGO, proc_pid_statm),
	REG("maps",       S_IRUGO, proc_pid_maps_operations),
#ifdef CONFIG_NUMA
	REG("numa_maps",  S_IRUGO, proc_pid_numa_maps_operations),
#endif
	REG("mem",        S_IRUSR|S_IWUSR, proc_mem_operations),
	LNK("cwd",        proc_cwd_link),
	LNK("root",       proc_root_link),
	LNK("exe",        proc_exe_link),
	REG("mounts",     S_IRUGO, proc_mounts_operations),
	REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
	REG("mountstats", S_IRUSR, proc_mountstats_operations),
#ifdef CONFIG_PROC_PAGE_MONITOR
	REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
	REG("smaps",      S_IRUGO, proc_pid_smaps_operations),
	REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
	REG("pagemap",    S_IRUSR, proc_pagemap_operations),
#endif
#ifdef CONFIG_SECURITY
	DIR("attr",       S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
#endif
#ifdef CONFIG_KALLSYMS
	ONE("wchan",      S_IRUGO, proc_pid_wchan),
#endif
#ifdef CONFIG_STACKTRACE
	ONE("stack",      S_IRUSR, proc_pid_stack),
#endif
#ifdef CONFIG_SCHED_INFO
	ONE("schedstat",  S_IRUGO, proc_pid_schedstat),
#endif
#ifdef CONFIG_LATENCYTOP
	REG("latency",  S_IRUGO, proc_lstats_operations),
#endif
#ifdef CONFIG_PROC_PID_CPUSET
	ONE("cpuset",     S_IRUGO, proc_cpuset_show),
#endif
#ifdef CONFIG_CGROUPS
	ONE("cgroup",  S_IRUGO, proc_cgroup_show),
#endif
#ifdef CONFIG_PROC_CPU_RESCTRL
	ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
#endif
	ONE("oom_score",  S_IRUGO, proc_oom_score),
	REG("oom_adj",    S_IRUGO|S_IWUSR, proc_oom_adj_operations),
	REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
#ifdef CONFIG_AUDIT
	REG("loginuid",   S_IWUSR|S_IRUGO, proc_loginuid_operations),
	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
#endif
#ifdef CONFIG_FAULT_INJECTION
	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
	REG("fail-nth", 0644, proc_fail_nth_operations),
#endif
#ifdef CONFIG_ELF_CORE
	REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),
#endif
#ifdef CONFIG_TASK_IO_ACCOUNTING
	ONE("io",	S_IRUSR, proc_tgid_io_accounting),
#endif
#ifdef CONFIG_USER_NS
	REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
	REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
	REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
	REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),
#endif
#if defined(CONFIG_CHECKPOINT_RESTORE) && defined(CONFIG_POSIX_TIMERS)
	REG("timers",	  S_IRUGO, proc_timers_operations),
#endif
	REG("timerslack_ns", S_IRUGO|S_IWUGO, proc_pid_set_timerslack_ns_operations),
#ifdef CONFIG_LIVEPATCH
	ONE("patch_state",  S_IRUSR, proc_pid_patch_state),
#endif
#ifdef CONFIG_STACKLEAK_METRICS
	ONE("stack_depth", S_IRUGO, proc_stack_depth),
#endif
#ifdef CONFIG_PROC_PID_ARCH_STATUS
	ONE("arch_status", S_IRUGO, proc_pid_arch_status),
#endif
#ifdef CONFIG_SECCOMP_CACHE_DEBUG
	ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
#endif
#ifdef CONFIG_KSM
	ONE("ksm_merging_pages",  S_IRUSR, proc_pid_ksm_merging_pages),
	ONE("ksm_stat",  S_IRUSR, proc_pid_ksm_stat),
#endif
};

static int proc_tgid_base_readdir(struct file *file, struct dir_context *ctx)
{
	return proc_pident_readdir(file, ctx,
				   tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
}

static const struct file_operations proc_tgid_base_operations = {
	.read		= generic_read_dir,
	.iterate_shared	= proc_tgid_base_readdir,
	.llseek		= generic_file_llseek,
};

struct pid *tgid_pidfd_to_pid(const struct file *file)
{
	if (file->f_op != &proc_tgid_base_operations)
		return ERR_PTR(-EBADF);

	return proc_pid(file_inode(file));
}

static struct dentry *proc_tgid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
	return proc_pident_lookup(dir, dentry,
				  tgid_base_stuff,
				  tgid_base_stuff + ARRAY_SIZE(tgid_base_stuff));
}

static const struct inode_operations proc_tgid_base_inode_operations = {
	.lookup		= proc_tgid_base_lookup,
	.getattr	= pid_getattr,
	.setattr	= proc_setattr,
	.permission	= proc_pid_permission,
};

/**
 * proc_flush_pid -  Remove dcache entries for @pid from the /proc dcache.
 * @pid: pid that should be flushed.
 *
 * This function walks a list of inodes (that belong to any proc
 * filesystem) that are attached to the pid and flushes them from
 * the dentry cache.
 *
 * It is safe and reasonable to cache /proc entries for a task until
 * that task exits.  After that they just clog up the dcache with
 * useless entries, possibly causing useful dcache entries to be
 * flushed instead.  This routine is provided to flush those useless
 * dcache entries when a process is reaped.
 *
 * NOTE: This routine is just an optimization so it does not guarantee
 *       that no dcache entries will exist after a process is reaped
 *       it just makes it very unlikely that any will persist.
 */

void proc_flush_pid(struct pid *pid)
{
	proc_invalidate_siblings_dcache(&pid->inodes, &pid->lock);
}

static struct dentry *proc_pid_instantiate(struct dentry * dentry,
				   struct task_struct *task, const void *ptr)
{
	struct inode *inode;

	inode = proc_pid_make_base_inode(dentry->d_sb, task,
					 S_IFDIR | S_IRUGO | S_IXUGO);
	if (!inode)
		return ERR_PTR(-ENOENT);

	inode->i_op = &proc_tgid_base_inode_operations;
	inode->i_fop = &proc_tgid_base_operations;
	inode->i_flags|=S_IMMUTABLE;

	set_nlink(inode, nlink_tgid);
	pid_update_inode(task, inode);

	d_set_d_op(dentry, &pid_dentry_operations);
	return d_splice_alias(inode, dentry);
}

struct dentry *proc_pid_lookup(struct dentry *dentry, unsigned int flags)
{
	struct task_struct *task;
	unsigned tgid;
	struct proc_fs_info *fs_info;
	struct pid_namespace *ns;
	struct dentry *result = ERR_PTR(-ENOENT);

	tgid = name_to_int(&dentry->d_name);
	if (tgid == ~0U)
		goto out;

	fs_info = proc_sb_info(dentry->d_sb);
	ns = fs_info->pid_ns;
	rcu_read_lock();
	task = find_task_by_pid_ns(tgid, ns);
	if (task)
		get_task_struct(task);
	rcu_read_unlock();
	if (!task)
		goto out;

	/* Limit procfs to only ptraceable tasks */
	if (fs_info->hide_pid == HIDEPID_NOT_PTRACEABLE) {
		if (!has_pid_permissions(fs_info, task, HIDEPID_NO_ACCESS))
			goto out_put_task;
	}

	result = proc_pid_instantiate(dentry, task, NULL);
out_put_task:
	put_task_struct(task);
out:
	return result;
}

/*
 * Find the first task with tgid >= tgid
 *
 */
struct tgid_iter {
	unsigned int tgid;
	struct task_struct *task;
};
static struct tgid_iter next_tgid(struct pid_namespace *ns, struct tgid_iter iter)
{
	struct pid *pid;

	if (iter.task)
		put_task_struct(iter.task);
	rcu_read_lock();
retry:
	iter.task = NULL;
	pid = find_ge_pid(iter.tgid, ns);
	if (pid) {
		iter.tgid = pid_nr_ns(pid, ns);
		iter.task = pid_task(pid, PIDTYPE_TGID);
		if (!iter.task) {
			iter.tgid += 1;
			goto retry;
		}
		get_task_struct(iter.task);
	}
	rcu_read_unlock();
	return iter;
}

#define TGID_OFFSET (FIRST_PROCESS_ENTRY + 2)

/* for the /proc/ directory itself, after non-process stuff has been done */
int proc_pid_readdir(struct file *file, struct dir_context *ctx)
{
	struct tgid_iter iter;
	struct proc_fs_info *fs_info = proc_sb_info(file_inode(file)->i_sb);
	struct pid_namespace *ns = proc_pid_ns(file_inode(file)->i_sb);
	loff_t pos = ctx->pos;

	if (pos >= PID_MAX_LIMIT + TGID_OFFSET)
		return 0;

	if (pos == TGID_OFFSET - 2) {
		struct inode *inode = d_inode(fs_info->proc_self);
		if (!dir_emit(ctx, "self", 4, inode->i_ino, DT_LNK))
			return 0;
		ctx->pos = pos = pos + 1;
	}
	if (pos == TGID_OFFSET - 1) {
		struct inode *inode = d_inode(fs_info->proc_thread_self);
		if (!dir_emit(ctx, "thread-self", 11, inode->i_ino, DT_LNK))
			return 0;
		ctx->pos = pos = pos + 1;
	}
	iter.tgid = pos - TGID_OFFSET;
	iter.task = NULL;
	for (iter = next_tgid(ns, iter);
	     iter.task;
	     iter.tgid += 1, iter = next_tgid(ns, iter)) {
		char name[10 + 1];
		unsigned int len;

		cond_resched();
		if (!has_pid_permissions(fs_info, iter.task, HIDEPID_INVISIBLE))
			continue;

		len = snprintf(name, sizeof(name), "%u", iter.tgid);
		ctx->pos = iter.tgid + TGID_OFFSET;
		if (!proc_fill_cache(file, ctx, name, len,
				     proc_pid_instantiate, iter.task, NULL)) {
			put_task_struct(iter.task);
			return 0;
		}
	}
	ctx->pos = PID_MAX_LIMIT + TGID_OFFSET;
	return 0;
}

/*
 * proc_tid_comm_permission is a special permission function exclusively
 * used for the node /proc/<pid>/task/<tid>/comm.
 * It bypasses generic permission checks in the case where a task of the same
 * task group attempts to access the node.
 * The rationale behind this is that glibc and bionic access this node for
 * cross thread naming (pthread_set/getname_np(!self)). However, if
 * PR_SET_DUMPABLE gets set to 0 this node among others becomes uid=0 gid=0,
 * which locks out the cross thread naming implementation.
 * This function makes sure that the node is always accessible for members of
 * same thread group.
 */
static int proc_tid_comm_permission(struct user_namespace *mnt_userns,
				    struct inode *inode, int mask)
{
	bool is_same_tgroup;
	struct task_struct *task;

	task = get_proc_task(inode);
	if (!task)
		return -ESRCH;
	is_same_tgroup = same_thread_group(current, task);
	put_task_struct(task);

	if (likely(is_same_tgroup && !(mask & MAY_EXEC))) {
		/* This file (/proc/<pid>/task/<tid>/comm) can always be
		 * read or written by the members of the corresponding
		 * thread group.
		 */
		return 0;
	}

	return generic_permission(&init_user_ns, inode, mask);
}

static const struct inode_operations proc_tid_comm_inode_operations = {
		.permission = proc_tid_comm_permission,
};

/*
 * Tasks
 */
static const struct pid_entry tid_base_stuff[] = {
	DIR("fd",        S_IRUSR|S_IXUSR, proc_fd_inode_operations, proc_fd_operations),
	DIR("fdinfo",    S_IRUGO|S_IXUGO, proc_fdinfo_inode_operations, proc_fdinfo_operations),
	DIR("ns",	 S_IRUSR|S_IXUGO, proc_ns_dir_inode_operations, proc_ns_dir_operations),
#ifdef CONFIG_NET
	DIR("net",        S_IRUGO|S_IXUGO, proc_net_inode_operations, proc_net_operations),
#endif
	REG("environ",   S_IRUSR, proc_environ_operations),
	REG("auxv",      S_IRUSR, proc_auxv_operations),
	ONE("status",    S_IRUGO, proc_pid_status),
	ONE("personality", S_IRUSR, proc_pid_personality),
	ONE("limits",	 S_IRUGO, proc_pid_limits),
#ifdef CONFIG_SCHED_DEBUG
	REG("sched",     S_IRUGO|S_IWUSR, proc_pid_sched_operations),
#endif
	NOD("comm",      S_IFREG|S_IRUGO|S_IWUSR,
			 &proc_tid_comm_inode_operations,
			 &proc_pid_set_comm_operations, {}),
#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
	ONE("syscall",   S_IRUSR, proc_pid_syscall),
#endif
	REG("cmdline",   S_IRUGO, proc_pid_cmdline_ops),
	ONE("stat",      S_IRUGO, proc_tid_stat),
	ONE("statm",     S_IRUGO, proc_pid_statm),
	REG("maps",      S_IRUGO, proc_pid_maps_operations),
#ifdef CONFIG_PROC_CHILDREN
	REG("children",  S_IRUGO, proc_tid_children_operations),
#endif
#ifdef CONFIG_NUMA
	REG("numa_maps", S_IRUGO, proc_pid_numa_maps_operations),
#endif
	REG("mem",       S_IRUSR|S_IWUSR, proc_mem_operations),
	LNK("cwd",       proc_cwd_link),
	LNK("root",      proc_root_link),
	LNK("exe",       proc_exe_link),
	REG("mounts",    S_IRUGO, proc_mounts_operations),
	REG("mountinfo",  S_IRUGO, proc_mountinfo_operations),
#ifdef CONFIG_PROC_PAGE_MONITOR
	REG("clear_refs", S_IWUSR, proc_clear_refs_operations),
	REG("smaps",     S_IRUGO, proc_pid_smaps_operations),
	REG("smaps_rollup", S_IRUGO, proc_pid_smaps_rollup_operations),
	REG("pagemap",    S_IRUSR, proc_pagemap_operations),
#endif
#ifdef CONFIG_SECURITY
	DIR("attr",      S_IRUGO|S_IXUGO, proc_attr_dir_inode_operations, proc_attr_dir_operations),
#endif
#ifdef CONFIG_KALLSYMS
	ONE("wchan",     S_IRUGO, proc_pid_wchan),
#endif
#ifdef CONFIG_STACKTRACE
	ONE("stack",      S_IRUSR, proc_pid_stack),
#endif
#ifdef CONFIG_SCHED_INFO
	ONE("schedstat", S_IRUGO, proc_pid_schedstat),
#endif
#ifdef CONFIG_LATENCYTOP
	REG("latency",  S_IRUGO, proc_lstats_operations),
#endif
#ifdef CONFIG_PROC_PID_CPUSET
	ONE("cpuset",    S_IRUGO, proc_cpuset_show),
#endif
#ifdef CONFIG_CGROUPS
	ONE("cgroup",  S_IRUGO, proc_cgroup_show),
#endif
#ifdef CONFIG_PROC_CPU_RESCTRL
	ONE("cpu_resctrl_groups", S_IRUGO, proc_resctrl_show),
#endif
	ONE("oom_score", S_IRUGO, proc_oom_score),
	REG("oom_adj",   S_IRUGO|S_IWUSR, proc_oom_adj_operations),
	REG("oom_score_adj", S_IRUGO|S_IWUSR, proc_oom_score_adj_operations),
#ifdef CONFIG_AUDIT
	REG("loginuid",  S_IWUSR|S_IRUGO, proc_loginuid_operations),
	REG("sessionid",  S_IRUGO, proc_sessionid_operations),
#endif
#ifdef CONFIG_FAULT_INJECTION
	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
	REG("fail-nth", 0644, proc_fail_nth_operations),
#endif
#ifdef CONFIG_TASK_IO_ACCOUNTING
	ONE("io",	S_IRUSR, proc_tid_io_accounting),
#endif
#ifdef CONFIG_USER_NS
	REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
	REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
	REG("projid_map", S_IRUGO|S_IWUSR, proc_projid_map_operations),
	REG("setgroups",  S_IRUGO|S_IWUSR, proc_setgroups_operations),
#endif
#ifdef CONFIG_LIVEPATCH
	ONE("patch_state",  S_IRUSR, proc_pid_patch_state),
#endif
#ifdef CONFIG_PROC_PID_ARCH_STATUS
	ONE("arch_status", S_IRUGO, proc_pid_arch_status),
#endif
#ifdef CONFIG_SECCOMP_CACHE_DEBUG
	ONE("seccomp_cache", S_IRUSR, proc_pid_seccomp_cache),
#endif
#ifdef CONFIG_KSM
	ONE("ksm_merging_pages",  S_IRUSR, proc_pid_ksm_merging_pages),
	ONE("ksm_stat",  S_IRUSR, proc_pid_ksm_stat),
#endif
};

static int proc_tid_base_readdir(struct file *file, struct dir_context *ctx)
{
	return proc_pident_readdir(file, ctx,
				   tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
}

static struct dentry *proc_tid_base_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
{
	return proc_pident_lookup(dir, dentry,
				  tid_base_stuff,
				  tid_base_stuff + ARRAY_SIZE(tid_base_stuff));
}

static const struct file_operations proc_tid_base_operations = {
	.read		= generic_read_dir,
	.iterate_shared	= proc_tid_base_readdir,
	.llseek		= generic_file_llseek,
};

static const struct inode_operations proc_tid_base_inode_operations = {
	.lookup		= proc_tid_base_lookup,
	.getattr	= pid_getattr,
	.setattr	= proc_setattr,
};

static struct dentry *proc_task_instantiate(struct dentry *dentry,
	struct task_struct *task, const void *ptr)
{
	struct inode *inode;
	inode = proc_pid_make_base_inode(dentry->d_sb, task,
					 S_IFDIR | S_IRUGO | S_IXUGO);
	if (!inode)
		return ERR_PTR(-ENOENT);

	inode->i_op = &proc_tid_base_inode_operations;
	inode->i_fop = &proc_tid_base_operations;
	inode->i_flags |= S_IMMUTABLE;

	set_nlink(inode, nlink_tid);
	pid_update_inode(task, inode);

	d_set_d_op(dentry, &pid_dentry_operations);
	return d_splice_alias(inode, dentry);
}

static struct dentry *proc_task_lookup(struct inode *dir, struct dentry * dentry, unsigned int flags)
{
	struct task_struct *task;
	struct task_struct *leader = get_proc_task(dir);
	unsigned tid;
	struct proc_fs_info *fs_info;
	struct pid_namespace *ns;
	struct dentry *result = ERR_PTR(-ENOENT);

	if (!leader)
		goto out_no_task;

	tid = name_to_int(&dentry->d_name);
	if (tid == ~0U)
		goto out;

	fs_info = proc_sb_info(dentry->d_sb);
	ns = fs_info->pid_ns;
	rcu_read_lock();
	task = find_task_by_pid_ns(tid, ns);
	if (task)
		get_task_struct(task);
	rcu_read_unlock();
	if (!task)
		goto out;
	if (!same_thread_group(leader, task))
		goto out_drop_task;

	result = proc_task_instantiate(dentry, task, NULL);
out_drop_task:
	put_task_struct(task);
out:
	put_task_struct(leader);
out_no_task:
	return result;
}

/*
 * Find the first tid of a thread group to return to user space.
 *
 * Usually this is just the thread group leader, but if the users
 * buffer was too small or there was a seek into the middle of the
 * directory we have more work todo.
 *
 * In the case of a short read we start with find_task_by_pid.
 *
 * In the case of a seek we start with the leader and walk nr
 * threads past it.
 */
static struct task_struct *first_tid(struct pid *pid, int tid, loff_t f_pos,
					struct pid_namespace *ns)
{
	struct task_struct *pos, *task;
	unsigned long nr = f_pos;

	if (nr != f_pos)	/* 32bit overflow? */
		return NULL;

	rcu_read_lock();
	task = pid_task(pid, PIDTYPE_PID);
	if (!task)
		goto fail;

	/* Attempt to start with the tid of a thread */
	if (tid && nr) {
		pos = find_task_by_pid_ns(tid, ns);
		if (pos && same_thread_group(pos, task))
			goto found;
	}

	/* If nr exceeds the number of threads there is nothing todo */
	if (nr >= get_nr_threads(task))
		goto fail;

	/* If we haven't found our starting place yet start
	 * with the leader and walk nr threads forward.
	 */
	pos = task = task->group_leader;
	do {
		if (!nr--)
			goto found;
	} while_each_thread(task, pos);
fail:
	pos = NULL;
	goto out;
found:
	get_task_struct(pos);
out:
	rcu_read_unlock();
	return pos;
}

/*
 * Find the next thread in the thread list.
 * Return NULL if there is an error or no next thread.
 *
 * The reference to the input task_struct is released.
 */
static struct task_struct *next_tid(struct task_struct *start)
{
	struct task_struct *pos = NULL;
	rcu_read_lock();
	if (pid_alive(start)) {
		pos = next_thread(start);
		if (thread_group_leader(pos))
			pos = NULL;
		else
			get_task_struct(pos);
	}
	rcu_read_unlock();
	put_task_struct(start);
	return pos;
}

/* for the /proc/TGID/task/ directories */
static int proc_task_readdir(struct file *file, struct dir_context *ctx)
{
	struct inode *inode = file_inode(file);
	struct task_struct *task;
	struct pid_namespace *ns;
	int tid;

	if (proc_inode_is_dead(inode))
		return -ENOENT;

	if (!dir_emit_dots(file, ctx))
		return 0;

	/* f_version caches the tgid value that the last readdir call couldn't
	 * return. lseek aka telldir automagically resets f_version to 0.
	 */
	ns = proc_pid_ns(inode->i_sb);
	tid = (int)file->f_version;
	file->f_version = 0;
	for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns);
	     task;
	     task = next_tid(task), ctx->pos++) {
		char name[10 + 1];
		unsigned int len;

		tid = task_pid_nr_ns(task, ns);
		if (!tid)
			continue;	/* The task has just exited. */
		len = snprintf(name, sizeof(name), "%u", tid);
		if (!proc_fill_cache(file, ctx, name, len,
				proc_task_instantiate, task, NULL)) {
			/* returning this tgid failed, save it as the first
			 * pid for the next readir call */
			file->f_version = (u64)tid;
			put_task_struct(task);
			break;
		}
	}

	return 0;
}

static int proc_task_getattr(struct user_namespace *mnt_userns,
			     const struct path *path, struct kstat *stat,
			     u32 request_mask, unsigned int query_flags)
{
	struct inode *inode = d_inode(path->dentry);
	struct task_struct *p = get_proc_task(inode);
	generic_fillattr(&init_user_ns, inode, stat);

	if (p) {
		stat->nlink += get_nr_threads(p);
		put_task_struct(p);
	}

	return 0;
}

static const struct inode_operations proc_task_inode_operations = {
	.lookup		= proc_task_lookup,
	.getattr	= proc_task_getattr,
	.setattr	= proc_setattr,
	.permission	= proc_pid_permission,
};

static const struct file_operations proc_task_operations = {
	.read		= generic_read_dir,
	.iterate_shared	= proc_task_readdir,
	.llseek		= generic_file_llseek,
};

void __init set_proc_pid_nlink(void)
{
	nlink_tid = pid_entry_nlink(tid_base_stuff, ARRAY_SIZE(tid_base_stuff));
	nlink_tgid = pid_entry_nlink(tgid_base_stuff, ARRAY_SIZE(tgid_base_stuff));
}