summaryrefslogtreecommitdiff
path: root/vm/vm_map.c
blob: 914741ecbd643c6ff215f91e6dda15a1fc196fe9 (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
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
/*
 * Mach Operating System
 * Copyright (c) 1991,1990,1989,1988,1987 Carnegie Mellon University.
 * Copyright (c) 1993,1994 The University of Utah and
 * the Computer Systems Laboratory (CSL).
 * All rights reserved.
 *
 * Permission to use, copy, modify and distribute this software and its
 * documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON, THE UNIVERSITY OF UTAH AND CSL ALLOW FREE USE OF
 * THIS SOFTWARE IN ITS "AS IS" CONDITION, AND DISCLAIM ANY LIABILITY
 * OF ANY KIND FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF
 * THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie Mellon
 * the rights to redistribute these changes.
 */
/*
 *	File:	vm/vm_map.c
 *	Author:	Avadis Tevanian, Jr., Michael Wayne Young
 *	Date:	1985
 *
 *	Virtual memory mapping module.
 */

#include <kern/printf.h>
#include <mach/kern_return.h>
#include <mach/port.h>
#include <mach/vm_attributes.h>
#include <mach/vm_param.h>
#include <kern/assert.h>
#include <kern/debug.h>
#include <kern/kalloc.h>
#include <kern/rbtree.h>
#include <kern/slab.h>
#include <vm/pmap.h>
#include <vm/vm_fault.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_resident.h>
#include <vm/vm_kern.h>
#include <ipc/ipc_port.h>

#if	MACH_KDB
#include <ddb/db_output.h>
#include <vm/vm_print.h>
#endif	/* MACH_KDB */

/*
 * Macros to copy a vm_map_entry. We must be careful to correctly
 * manage the wired page count. vm_map_entry_copy() creates a new
 * map entry to the same memory - the wired count in the new entry
 * must be set to zero. vm_map_entry_copy_full() creates a new
 * entry that is identical to the old entry.  This preserves the
 * wire count; it's used for map splitting and cache changing in
 * vm_map_copyout.
 */
#define vm_map_entry_copy(NEW,OLD) \
MACRO_BEGIN                                     \
                *(NEW) = *(OLD);                \
                (NEW)->is_shared = FALSE;	\
                (NEW)->needs_wakeup = FALSE;    \
                (NEW)->in_transition = FALSE;   \
                (NEW)->wired_count = 0;         \
                (NEW)->user_wired_count = 0;    \
MACRO_END

#define vm_map_entry_copy_full(NEW,OLD)        (*(NEW) = *(OLD))

/*
 *	Virtual memory maps provide for the mapping, protection,
 *	and sharing of virtual memory objects.  In addition,
 *	this module provides for an efficient virtual copy of
 *	memory from one map to another.
 *
 *	Synchronization is required prior to most operations.
 *
 *	Maps consist of an ordered doubly-linked list of simple
 *	entries; a hint and a red-black tree are used to speed up lookups.
 *
 *	Sharing maps have been deleted from this version of Mach.
 *	All shared objects are now mapped directly into the respective
 *	maps.  This requires a change in the copy on write strategy;
 *	the asymmetric (delayed) strategy is used for shared temporary
 *	objects instead of the symmetric (shadow) strategy.  This is
 *	selected by the (new) use_shared_copy bit in the object.  See
 *	vm_object_copy_temporary in vm_object.c for details.  All maps
 *	are now "top level" maps (either task map, kernel map or submap
 *	of the kernel map).
 *
 *	Since portions of maps are specified by start/end addreses,
 *	which may not align with existing map entries, all
 *	routines merely "clip" entries to these start/end values.
 *	[That is, an entry is split into two, bordering at a
 *	start or end value.]  Note that these clippings may not
 *	always be necessary (as the two resulting entries are then
 *	not changed); however, the clipping is done for convenience.
 *	No attempt is currently made to "glue back together" two
 *	abutting entries.
 *
 *	The symmetric (shadow) copy strategy implements virtual copy
 *	by copying VM object references from one map to
 *	another, and then marking both regions as copy-on-write.
 *	It is important to note that only one writeable reference
 *	to a VM object region exists in any map when this strategy
 *	is used -- this means that shadow object creation can be
 *	delayed until a write operation occurs.  The asymmetric (delayed)
 *	strategy allows multiple maps to have writeable references to
 *	the same region of a vm object, and hence cannot delay creating
 *	its copy objects.  See vm_object_copy_temporary() in vm_object.c.
 *	Copying of permanent objects is completely different; see
 *	vm_object_copy_strategically() in vm_object.c.
 */

struct kmem_cache    vm_map_cache;		/* cache for vm_map structures */
struct kmem_cache    vm_map_entry_cache;	/* cache for vm_map_entry structures */
struct kmem_cache    vm_map_kentry_cache;	/* cache for kernel entry structures */
struct kmem_cache    vm_map_copy_cache; 	/* cache for vm_map_copy structures */

/*
 *	Placeholder object for submap operations.  This object is dropped
 *	into the range by a call to vm_map_find, and removed when
 *	vm_map_submap creates the submap.
 */

static struct vm_object	vm_submap_object_store;
vm_object_t		vm_submap_object = &vm_submap_object_store;

/*
 *	vm_map_init:
 *
 *	Initialize the vm_map module.  Must be called before
 *	any other vm_map routines.
 *
 *	Map and entry structures are allocated from caches -- we must
 *	initialize those caches.
 *
 *	There are three caches of interest:
 *
 *	vm_map_cache:		used to allocate maps.
 *	vm_map_entry_cache:	used to allocate map entries.
 *	vm_map_kentry_cache:	used to allocate map entries for the kernel.
 *
 *	Kernel map entries are allocated from a special cache, using a custom
 *	page allocation function to avoid recursion. It would be difficult
 *	(perhaps impossible) for the kernel to allocate more memory to an entry
 *	cache when it became empty since the very act of allocating memory
 *	implies the creation of a new entry.
 */

vm_offset_t	kentry_data;
vm_size_t	kentry_data_size = KENTRY_DATA_SIZE;

static vm_offset_t kentry_pagealloc(vm_size_t size)
{
	vm_offset_t result;

	if (size > kentry_data_size)
		panic("vm_map: kentry memory exhausted");

	result = kentry_data;
	kentry_data += size;
	kentry_data_size -= size;
	return result;
}

void vm_map_init(void)
{
	kmem_cache_init(&vm_map_cache, "vm_map", sizeof(struct vm_map), 0,
			NULL, NULL, NULL, 0);
	kmem_cache_init(&vm_map_entry_cache, "vm_map_entry",
			sizeof(struct vm_map_entry), 0, NULL, NULL, NULL, 0);
	kmem_cache_init(&vm_map_kentry_cache, "vm_map_kentry",
			sizeof(struct vm_map_entry), 0, NULL, kentry_pagealloc,
			NULL, KMEM_CACHE_NOCPUPOOL | KMEM_CACHE_NOOFFSLAB
			      | KMEM_CACHE_NORECLAIM);
	kmem_cache_init(&vm_map_copy_cache, "vm_map_copy",
			sizeof(struct vm_map_copy), 0, NULL, NULL, NULL, 0);

	/*
	 *	Submap object is initialized by vm_object_init.
	 */
}

void vm_map_setup(map, pmap, min, max, pageable)
	vm_map_t	map;
	pmap_t		pmap;
	vm_offset_t	min, max;
	boolean_t	pageable;
{
	vm_map_first_entry(map) = vm_map_to_entry(map);
	vm_map_last_entry(map)  = vm_map_to_entry(map);
	map->hdr.nentries = 0;
	map->hdr.entries_pageable = pageable;
	rbtree_init(&map->hdr.tree);

	map->size = 0;
	map->ref_count = 1;
	map->pmap = pmap;
	map->min_offset = min;
	map->max_offset = max;
	map->wiring_required = FALSE;
	map->wait_for_space = FALSE;
	map->first_free = vm_map_to_entry(map);
	map->hint = vm_map_to_entry(map);
	vm_map_lock_init(map);
	simple_lock_init(&map->ref_lock);
	simple_lock_init(&map->hint_lock);
}

/*
 *	vm_map_create:
 *
 *	Creates and returns a new empty VM map with
 *	the given physical map structure, and having
 *	the given lower and upper address bounds.
 */
vm_map_t vm_map_create(pmap, min, max, pageable)
	pmap_t		pmap;
	vm_offset_t	min, max;
	boolean_t	pageable;
{
	vm_map_t	result;

	result = (vm_map_t) kmem_cache_alloc(&vm_map_cache);
	if (result == VM_MAP_NULL)
		panic("vm_map_create");

	vm_map_setup(result, pmap, min, max, pageable);

	return(result);
}

/*
 *	vm_map_entry_create:	[ internal use only ]
 *
 *	Allocates a VM map entry for insertion in the
 *	given map (or map copy).  No fields are filled.
 */
#define	vm_map_entry_create(map) \
	    _vm_map_entry_create(&(map)->hdr)

#define	vm_map_copy_entry_create(copy) \
	    _vm_map_entry_create(&(copy)->cpy_hdr)

vm_map_entry_t _vm_map_entry_create(map_header)
	struct vm_map_header *map_header;
{
	kmem_cache_t cache;
	vm_map_entry_t	entry;

	if (map_header->entries_pageable)
	    cache = &vm_map_entry_cache;
	else
	    cache = &vm_map_kentry_cache;

	entry = (vm_map_entry_t) kmem_cache_alloc(cache);
	if (entry == VM_MAP_ENTRY_NULL)
		panic("vm_map_entry_create");

	return(entry);
}

/*
 *	vm_map_entry_dispose:	[ internal use only ]
 *
 *	Inverse of vm_map_entry_create.
 */
#define	vm_map_entry_dispose(map, entry) \
	_vm_map_entry_dispose(&(map)->hdr, (entry))

#define	vm_map_copy_entry_dispose(map, entry) \
	_vm_map_entry_dispose(&(copy)->cpy_hdr, (entry))

void _vm_map_entry_dispose(map_header, entry)
	struct vm_map_header *map_header;
	vm_map_entry_t	entry;
{
	kmem_cache_t cache;

	if (map_header->entries_pageable)
	    cache = &vm_map_entry_cache;
	else
	    cache = &vm_map_kentry_cache;

	kmem_cache_free(cache, (vm_offset_t) entry);
}

/*
 *	Red-black tree lookup/insert comparison functions
 */
static inline int vm_map_entry_cmp_lookup(vm_offset_t addr,
                                          const struct rbtree_node *node)
{
	struct vm_map_entry *entry;

	entry = rbtree_entry(node, struct vm_map_entry, tree_node);

	if (addr < entry->vme_start)
		return -1;
	else if (addr < entry->vme_end)
		return 0;
	else
		return 1;
}

static inline int vm_map_entry_cmp_insert(const struct rbtree_node *a,
                                          const struct rbtree_node *b)
{
	struct vm_map_entry *entry;

	entry = rbtree_entry(a, struct vm_map_entry, tree_node);
	return vm_map_entry_cmp_lookup(entry->vme_start, b);
}

/*
 *	vm_map_entry_{un,}link:
 *
 *	Insert/remove entries from maps (or map copies).
 *
 *	The start and end addresses of the entries must be properly set
 *	before using these macros.
 */
#define vm_map_entry_link(map, after_where, entry)	\
	_vm_map_entry_link(&(map)->hdr, after_where, entry)

#define vm_map_copy_entry_link(copy, after_where, entry)	\
	_vm_map_entry_link(&(copy)->cpy_hdr, after_where, entry)

#define _vm_map_entry_link(hdr, after_where, entry)	\
	MACRO_BEGIN					\
	(hdr)->nentries++;				\
	(entry)->vme_prev = (after_where);		\
	(entry)->vme_next = (after_where)->vme_next;	\
	(entry)->vme_prev->vme_next =			\
	 (entry)->vme_next->vme_prev = (entry);		\
	rbtree_insert(&(hdr)->tree, &(entry)->tree_node,	\
		      vm_map_entry_cmp_insert);		\
	MACRO_END

#define vm_map_entry_unlink(map, entry)			\
	_vm_map_entry_unlink(&(map)->hdr, entry)

#define vm_map_copy_entry_unlink(copy, entry)			\
	_vm_map_entry_unlink(&(copy)->cpy_hdr, entry)

#define _vm_map_entry_unlink(hdr, entry)		\
	MACRO_BEGIN					\
	(hdr)->nentries--;				\
	(entry)->vme_next->vme_prev = (entry)->vme_prev; \
	(entry)->vme_prev->vme_next = (entry)->vme_next; \
	rbtree_remove(&(hdr)->tree, &(entry)->tree_node);	\
	MACRO_END

/*
 *	vm_map_reference:
 *
 *	Creates another valid reference to the given map.
 *
 */
void vm_map_reference(map)
	vm_map_t	map;
{
	if (map == VM_MAP_NULL)
		return;

	simple_lock(&map->ref_lock);
	map->ref_count++;
	simple_unlock(&map->ref_lock);
}

/*
 *	vm_map_deallocate:
 *
 *	Removes a reference from the specified map,
 *	destroying it if no references remain.
 *	The map should not be locked.
 */
void vm_map_deallocate(map)
	vm_map_t	map;
{
	int		c;

	if (map == VM_MAP_NULL)
		return;

	simple_lock(&map->ref_lock);
	c = --map->ref_count;
	simple_unlock(&map->ref_lock);

	if (c > 0) {
		return;
	}

	projected_buffer_collect(map);
	(void) vm_map_delete(map, map->min_offset, map->max_offset);

	pmap_destroy(map->pmap);

	kmem_cache_free(&vm_map_cache, (vm_offset_t) map);
}

/*
 *	SAVE_HINT:
 *
 *	Saves the specified entry as the hint for
 *	future lookups.  Performs necessary interlocks.
 */
#define	SAVE_HINT(map,value) \
		simple_lock(&(map)->hint_lock); \
		(map)->hint = (value); \
		simple_unlock(&(map)->hint_lock);

/*
 *	vm_map_lookup_entry:	[ internal use only ]
 *
 *	Finds the map entry containing (or
 *	immediately preceding) the specified address
 *	in the given map; the entry is returned
 *	in the "entry" parameter.  The boolean
 *	result indicates whether the address is
 *	actually contained in the map.
 */
boolean_t vm_map_lookup_entry(map, address, entry)
	vm_map_t	map;
	vm_offset_t	address;
	vm_map_entry_t	*entry;		/* OUT */
{
	struct rbtree_node	*node;
	vm_map_entry_t		hint;

	/*
	 *	First, make a quick check to see if we are already
	 *	looking at the entry we want (which is often the case).
	 */

	simple_lock(&map->hint_lock);
	hint = map->hint;
	simple_unlock(&map->hint_lock);

	if ((hint != vm_map_to_entry(map)) && (address >= hint->vme_start)) {
		if (address < hint->vme_end) {
			*entry = hint;
			return(TRUE);
		} else {
			vm_map_entry_t next = hint->vme_next;

			if ((next == vm_map_to_entry(map))
			    || (address < next->vme_start)) {
				*entry = hint;
				return(FALSE);
			}
		}
	}

	/*
	 *	If the hint didn't help, use the red-black tree.
	 */

	node = rbtree_lookup_nearest(&map->hdr.tree, address,
				     vm_map_entry_cmp_lookup, RBTREE_LEFT);

	if (node == NULL) {
		*entry = vm_map_to_entry(map);
		SAVE_HINT(map, *entry);
		return(FALSE);
	} else {
		*entry = rbtree_entry(node, struct vm_map_entry, tree_node);
		SAVE_HINT(map, *entry);
		return((address < (*entry)->vme_end) ? TRUE : FALSE);
	}
}

/*
 *      Routine:     invalid_user_access
 *
 *	Verifies whether user access is valid.
 */

boolean_t
invalid_user_access(map, start, end, prot)
        vm_map_t map;
        vm_offset_t start, end;
        vm_prot_t prot;
{
        vm_map_entry_t entry;

        return (map == VM_MAP_NULL || map == kernel_map ||
		!vm_map_lookup_entry(map, start, &entry) ||
		entry->vme_end < end ||
		(prot & ~(entry->protection)));
}


/*
 *	Routine:	vm_map_find_entry
 *	Purpose:
 *		Allocate a range in the specified virtual address map,
 *		returning the entry allocated for that range.
 *		Used by kmem_alloc, etc.  Returns wired entries.
 *
 *		The map must be locked.
 *
 *		If an entry is allocated, the object/offset fields
 *		are initialized to zero.  If an object is supplied,
 *		then an existing entry may be extended.
 */
kern_return_t vm_map_find_entry(map, address, size, mask, object, o_entry)
	vm_map_t		map;
	vm_offset_t		*address;	/* OUT */
	vm_size_t		size;
	vm_offset_t		mask;
	vm_object_t		object;
	vm_map_entry_t		*o_entry;	/* OUT */
{
	vm_map_entry_t	entry, new_entry;
	vm_offset_t	start;
	vm_offset_t	end;

	/*
	 *	Look for the first possible address;
	 *	if there's already something at this
	 *	address, we have to start after it.
	 */

	if ((entry = map->first_free) == vm_map_to_entry(map))
		start = map->min_offset;
	else
		start = entry->vme_end;

	/*
	 *	In any case, the "entry" always precedes
	 *	the proposed new region throughout the loop:
	 */

	while (TRUE) {
		vm_map_entry_t	next;

		/*
		 *	Find the end of the proposed new region.
		 *	Be sure we didn't go beyond the end, or
		 *	wrap around the address.
		 */

		if (((start + mask) & ~mask) < start) {
			printf_once("no more room for vm_map_find_entry in %p\n", map);
			return(KERN_NO_SPACE);
		}
		start = ((start + mask) & ~mask);
		end = start + size;

		if ((end > map->max_offset) || (end < start)) {
			printf_once("no more room for vm_map_find_entry in %p\n", map);
			return(KERN_NO_SPACE);
		}

		/*
		 *	If there are no more entries, we must win.
		 */

		next = entry->vme_next;
		if (next == vm_map_to_entry(map))
			break;

		/*
		 *	If there is another entry, it must be
		 *	after the end of the potential new region.
		 */

		if (next->vme_start >= end)
			break;

		/*
		 *	Didn't fit -- move to the next entry.
		 */

		entry = next;
		start = entry->vme_end;
	}

	/*
	 *	At this point,
	 *		"start" and "end" should define the endpoints of the
	 *			available new range, and
	 *		"entry" should refer to the region before the new
	 *			range, and
	 *
	 *		the map should be locked.
	 */

	*address = start;

	/*
	 *	See whether we can avoid creating a new entry by
	 *	extending one of our neighbors.  [So far, we only attempt to
	 *	extend from below.]
	 */

	if ((object != VM_OBJECT_NULL) &&
	    (entry != vm_map_to_entry(map)) &&
	    (entry->vme_end == start) &&
	    (!entry->is_shared) &&
	    (!entry->is_sub_map) &&
	    (entry->object.vm_object == object) &&
	    (entry->needs_copy == FALSE) &&
	    (entry->inheritance == VM_INHERIT_DEFAULT) &&
	    (entry->protection == VM_PROT_DEFAULT) &&
	    (entry->max_protection == VM_PROT_ALL) &&
	    (entry->wired_count == 1) &&
	    (entry->user_wired_count == 0) &&
	    (entry->projected_on == 0)) {
		/*
		 *	Because this is a special case,
		 *	we don't need to use vm_object_coalesce.
		 */

		entry->vme_end = end;
		new_entry = entry;
	} else {
		new_entry = vm_map_entry_create(map);

		new_entry->vme_start = start;
		new_entry->vme_end = end;

		new_entry->is_shared = FALSE;
		new_entry->is_sub_map = FALSE;
		new_entry->object.vm_object = VM_OBJECT_NULL;
		new_entry->offset = (vm_offset_t) 0;

		new_entry->needs_copy = FALSE;

		new_entry->inheritance = VM_INHERIT_DEFAULT;
		new_entry->protection = VM_PROT_DEFAULT;
		new_entry->max_protection = VM_PROT_ALL;
		new_entry->wired_count = 1;
		new_entry->user_wired_count = 0;

		new_entry->in_transition = FALSE;
		new_entry->needs_wakeup = FALSE;
		new_entry->projected_on = 0;

		/*
		 *	Insert the new entry into the list
		 */

		vm_map_entry_link(map, entry, new_entry);
    	}

	map->size += size;

	/*
	 *	Update the free space hint and the lookup hint
	 */

	map->first_free = new_entry;
	SAVE_HINT(map, new_entry);

	*o_entry = new_entry;
	return(KERN_SUCCESS);
}

int vm_map_pmap_enter_print = FALSE;
int vm_map_pmap_enter_enable = FALSE;

/*
 *	Routine:	vm_map_pmap_enter
 *
 *	Description:
 *		Force pages from the specified object to be entered into
 *		the pmap at the specified address if they are present.
 *		As soon as a page not found in the object the scan ends.
 *
 *	Returns:
 *		Nothing.
 *
 *	In/out conditions:
 *		The source map should not be locked on entry.
 */
void
vm_map_pmap_enter(map, addr, end_addr, object, offset, protection)
	vm_map_t	map;
	vm_offset_t 	addr;
	vm_offset_t	end_addr;
	vm_object_t 	object;
	vm_offset_t	offset;
	vm_prot_t	protection;
{
	while (addr < end_addr) {
		vm_page_t	m;

		vm_object_lock(object);
		vm_object_paging_begin(object);

		m = vm_page_lookup(object, offset);
		if (m == VM_PAGE_NULL || m->absent) {
			vm_object_paging_end(object);
			vm_object_unlock(object);
			return;
		}

		if (vm_map_pmap_enter_print) {
			printf("vm_map_pmap_enter:");
			printf("map: %p, addr: %lx, object: %p, offset: %lx\n",
				map, addr, object, offset);
		}

		m->busy = TRUE;
		vm_object_unlock(object);

		PMAP_ENTER(map->pmap, addr, m,
			   protection, FALSE);

		vm_object_lock(object);
		PAGE_WAKEUP_DONE(m);
		vm_page_lock_queues();
		if (!m->active && !m->inactive)
		    vm_page_activate(m);
		vm_page_unlock_queues();
		vm_object_paging_end(object);
		vm_object_unlock(object);

		offset += PAGE_SIZE;
		addr += PAGE_SIZE;
	}
}

/*
 *	Routine:	vm_map_enter
 *
 *	Description:
 *		Allocate a range in the specified virtual address map.
 *		The resulting range will refer to memory defined by
 *		the given memory object and offset into that object.
 *
 *		Arguments are as defined in the vm_map call.
 */
kern_return_t vm_map_enter(
		map,
		address, size, mask, anywhere,
		object, offset, needs_copy,
		cur_protection, max_protection,	inheritance)
	vm_map_t	map;
	vm_offset_t	*address;	/* IN/OUT */
	vm_size_t	size;
	vm_offset_t	mask;
	boolean_t	anywhere;
	vm_object_t	object;
	vm_offset_t	offset;
	boolean_t	needs_copy;
	vm_prot_t	cur_protection;
	vm_prot_t	max_protection;
	vm_inherit_t	inheritance;
{
	vm_map_entry_t	entry;
	vm_offset_t	start;
	vm_offset_t	end;
	kern_return_t	result = KERN_SUCCESS;

#define	RETURN(value)	{ result = value; goto BailOut; }

	if (size == 0)
		return KERN_INVALID_ARGUMENT;

 StartAgain: ;

	start = *address;

	if (anywhere) {
		vm_map_lock(map);

		/*
		 *	Calculate the first possible address.
		 */

		if (start < map->min_offset)
			start = map->min_offset;
		if (start > map->max_offset)
			RETURN(KERN_NO_SPACE);

		/*
		 *	Look for the first possible address;
		 *	if there's already something at this
		 *	address, we have to start after it.
		 */

		if (start == map->min_offset) {
			if ((entry = map->first_free) != vm_map_to_entry(map))
				start = entry->vme_end;
		} else {
			vm_map_entry_t	tmp_entry;
			if (vm_map_lookup_entry(map, start, &tmp_entry))
				start = tmp_entry->vme_end;
			entry = tmp_entry;
		}

		/*
		 *	In any case, the "entry" always precedes
		 *	the proposed new region throughout the
		 *	loop:
		 */

		while (TRUE) {
			vm_map_entry_t	next;

		    	/*
			 *	Find the end of the proposed new region.
			 *	Be sure we didn't go beyond the end, or
			 *	wrap around the address.
			 */

			if (((start + mask) & ~mask) < start) {
				printf_once("no more room for vm_map_enter in %p\n", map);
				RETURN(KERN_NO_SPACE);
			}
			start = ((start + mask) & ~mask);
			end = start + size;

			if ((end > map->max_offset) || (end < start)) {
				if (map->wait_for_space) {
					if (size <= (map->max_offset -
						     map->min_offset)) {
						assert_wait((event_t) map, TRUE);
						vm_map_unlock(map);
						thread_block((void (*)()) 0);
						goto StartAgain;
					}
				}

				printf_once("no more room for vm_map_enter in %p\n", map);
				RETURN(KERN_NO_SPACE);
			}

			/*
			 *	If there are no more entries, we must win.
			 */

			next = entry->vme_next;
			if (next == vm_map_to_entry(map))
				break;

			/*
			 *	If there is another entry, it must be
			 *	after the end of the potential new region.
			 */

			if (next->vme_start >= end)
				break;

			/*
			 *	Didn't fit -- move to the next entry.
			 */

			entry = next;
			start = entry->vme_end;
		}
		*address = start;
	} else {
		vm_map_entry_t		temp_entry;

		/*
		 *	Verify that:
		 *		the address doesn't itself violate
		 *		the mask requirement.
		 */

		if ((start & mask) != 0)
			return(KERN_NO_SPACE);

		vm_map_lock(map);

		/*
		 *	...	the address is within bounds
		 */

		end = start + size;

		if ((start < map->min_offset) ||
		    (end > map->max_offset) ||
		    (start >= end)) {
			RETURN(KERN_INVALID_ADDRESS);
		}

		/*
		 *	...	the starting address isn't allocated
		 */

		if (vm_map_lookup_entry(map, start, &temp_entry))
			RETURN(KERN_NO_SPACE);

		entry = temp_entry;

		/*
		 *	...	the next region doesn't overlap the
		 *		end point.
		 */

		if ((entry->vme_next != vm_map_to_entry(map)) &&
		    (entry->vme_next->vme_start < end))
			RETURN(KERN_NO_SPACE);
	}

	/*
	 *	At this point,
	 *		"start" and "end" should define the endpoints of the
	 *			available new range, and
	 *		"entry" should refer to the region before the new
	 *			range, and
	 *
	 *		the map should be locked.
	 */

	/*
	 *	See whether we can avoid creating a new entry (and object) by
	 *	extending one of our neighbors.  [So far, we only attempt to
	 *	extend from below.]
	 */

	if ((object == VM_OBJECT_NULL) &&
	    (entry != vm_map_to_entry(map)) &&
	    (entry->vme_end == start) &&
	    (!entry->is_shared) &&
	    (!entry->is_sub_map) &&
	    (entry->inheritance == inheritance) &&
	    (entry->protection == cur_protection) &&
	    (entry->max_protection == max_protection) &&
	    (entry->wired_count == 0) &&  /* implies user_wired_count == 0 */
	    (entry->projected_on == 0)) {
		if (vm_object_coalesce(entry->object.vm_object,
				VM_OBJECT_NULL,
				entry->offset,
				(vm_offset_t) 0,
				(vm_size_t)(entry->vme_end - entry->vme_start),
				(vm_size_t)(end - entry->vme_end))) {

			/*
			 *	Coalesced the two objects - can extend
			 *	the previous map entry to include the
			 *	new range.
			 */
			map->size += (end - entry->vme_end);
			entry->vme_end = end;
			RETURN(KERN_SUCCESS);
		}
	}

	/*
	 *	Create a new entry
	 */

	/**/ {
	vm_map_entry_t	new_entry;

	new_entry = vm_map_entry_create(map);

	new_entry->vme_start = start;
	new_entry->vme_end = end;

	new_entry->is_shared = FALSE;
	new_entry->is_sub_map = FALSE;
	new_entry->object.vm_object = object;
	new_entry->offset = offset;

	new_entry->needs_copy = needs_copy;

	new_entry->inheritance = inheritance;
	new_entry->protection = cur_protection;
	new_entry->max_protection = max_protection;
	new_entry->wired_count = 0;
	new_entry->user_wired_count = 0;

	new_entry->in_transition = FALSE;
	new_entry->needs_wakeup = FALSE;
	new_entry->projected_on = 0;

	/*
	 *	Insert the new entry into the list
	 */

	vm_map_entry_link(map, entry, new_entry);
	map->size += size;

	/*
	 *	Update the free space hint and the lookup hint
	 */

	if ((map->first_free == entry) &&
	    ((entry == vm_map_to_entry(map) ? map->min_offset : entry->vme_end)
	     >= new_entry->vme_start))
		map->first_free = new_entry;

	SAVE_HINT(map, new_entry);

	vm_map_unlock(map);

	if ((object != VM_OBJECT_NULL) &&
	    (vm_map_pmap_enter_enable) &&
	    (!anywhere)	 &&
	    (!needs_copy) &&
	    (size < (128*1024))) {
		vm_map_pmap_enter(map, start, end,
				  object, offset, cur_protection);
	}

	return(result);
	/**/ }

 BailOut: ;

	vm_map_unlock(map);
	return(result);

#undef	RETURN
}

/*
 *	vm_map_clip_start:	[ internal use only ]
 *
 *	Asserts that the given entry begins at or after
 *	the specified address; if necessary,
 *	it splits the entry into two.
 */
#define vm_map_clip_start(map, entry, startaddr) \
	MACRO_BEGIN \
	if ((startaddr) > (entry)->vme_start) \
		_vm_map_clip_start(&(map)->hdr,(entry),(startaddr)); \
	MACRO_END

#define vm_map_copy_clip_start(copy, entry, startaddr) \
	MACRO_BEGIN \
	if ((startaddr) > (entry)->vme_start) \
		_vm_map_clip_start(&(copy)->cpy_hdr,(entry),(startaddr)); \
	MACRO_END

/*
 *	This routine is called only when it is known that
 *	the entry must be split.
 */
void _vm_map_clip_start(map_header, entry, start)
	struct vm_map_header 	*map_header;
	vm_map_entry_t		entry;
	vm_offset_t		start;
{
	vm_map_entry_t	new_entry;

	/*
	 *	Split off the front portion --
	 *	note that we must insert the new
	 *	entry BEFORE this one, so that
	 *	this entry has the specified starting
	 *	address.
	 */

	new_entry = _vm_map_entry_create(map_header);
	vm_map_entry_copy_full(new_entry, entry);

	new_entry->vme_end = start;
	entry->offset += (start - entry->vme_start);
	entry->vme_start = start;

	_vm_map_entry_link(map_header, entry->vme_prev, new_entry);

	if (entry->is_sub_map)
	 	vm_map_reference(new_entry->object.sub_map);
	else
		vm_object_reference(new_entry->object.vm_object);
}

/*
 *	vm_map_clip_end:	[ internal use only ]
 *
 *	Asserts that the given entry ends at or before
 *	the specified address; if necessary,
 *	it splits the entry into two.
 */
#define vm_map_clip_end(map, entry, endaddr) \
	MACRO_BEGIN \
	if ((endaddr) < (entry)->vme_end) \
		_vm_map_clip_end(&(map)->hdr,(entry),(endaddr)); \
	MACRO_END

#define vm_map_copy_clip_end(copy, entry, endaddr) \
	MACRO_BEGIN \
	if ((endaddr) < (entry)->vme_end) \
		_vm_map_clip_end(&(copy)->cpy_hdr,(entry),(endaddr)); \
	MACRO_END

/*
 *	This routine is called only when it is known that
 *	the entry must be split.
 */
void _vm_map_clip_end(map_header, entry, end)
	struct vm_map_header 	*map_header;
	vm_map_entry_t		entry;
	vm_offset_t		end;
{
	vm_map_entry_t	new_entry;

	/*
	 *	Create a new entry and insert it
	 *	AFTER the specified entry
	 */

	new_entry = _vm_map_entry_create(map_header);
	vm_map_entry_copy_full(new_entry, entry);

	new_entry->vme_start = entry->vme_end = end;
	new_entry->offset += (end - entry->vme_start);

	_vm_map_entry_link(map_header, entry, new_entry);

	if (entry->is_sub_map)
	 	vm_map_reference(new_entry->object.sub_map);
	else
		vm_object_reference(new_entry->object.vm_object);
}

/*
 *	VM_MAP_RANGE_CHECK:	[ internal use only ]
 *
 *	Asserts that the starting and ending region
 *	addresses fall within the valid range of the map.
 */
#define	VM_MAP_RANGE_CHECK(map, start, end)		\
		{					\
		if (start < vm_map_min(map))		\
			start = vm_map_min(map);	\
		if (end > vm_map_max(map))		\
			end = vm_map_max(map);		\
		if (start > end)			\
			start = end;			\
		}

/*
 *	vm_map_submap:		[ kernel use only ]
 *
 *	Mark the given range as handled by a subordinate map.
 *
 *	This range must have been created with vm_map_find using
 *	the vm_submap_object, and no other operations may have been
 *	performed on this range prior to calling vm_map_submap.
 *
 *	Only a limited number of operations can be performed
 *	within this rage after calling vm_map_submap:
 *		vm_fault
 *	[Don't try vm_map_copyin!]
 *
 *	To remove a submapping, one must first remove the
 *	range from the superior map, and then destroy the
 *	submap (if desired).  [Better yet, don't try it.]
 */
kern_return_t vm_map_submap(map, start, end, submap)
	vm_map_t	map;
	vm_offset_t	start;
	vm_offset_t	end;
	vm_map_t	submap;
{
	vm_map_entry_t		entry;
	kern_return_t		result = KERN_INVALID_ARGUMENT;
	vm_object_t		object;

	vm_map_lock(map);

	VM_MAP_RANGE_CHECK(map, start, end);

	if (vm_map_lookup_entry(map, start, &entry)) {
		vm_map_clip_start(map, entry, start);
	}
	 else
		entry = entry->vme_next;

	vm_map_clip_end(map, entry, end);

	if ((entry->vme_start == start) && (entry->vme_end == end) &&
	    (!entry->is_sub_map) &&
	    ((object = entry->object.vm_object) == vm_submap_object) &&
	    (object->resident_page_count == 0) &&
	    (object->copy == VM_OBJECT_NULL) &&
	    (object->shadow == VM_OBJECT_NULL) &&
	    (!object->pager_created)) {
		entry->object.vm_object = VM_OBJECT_NULL;
		vm_object_deallocate(object);
		entry->is_sub_map = TRUE;
		vm_map_reference(entry->object.sub_map = submap);
		result = KERN_SUCCESS;
	}
	vm_map_unlock(map);

	return(result);
}

/*
 *	vm_map_protect:
 *
 *	Sets the protection of the specified address
 *	region in the target map.  If "set_max" is
 *	specified, the maximum protection is to be set;
 *	otherwise, only the current protection is affected.
 */
kern_return_t vm_map_protect(map, start, end, new_prot, set_max)
	vm_map_t	map;
	vm_offset_t	start;
	vm_offset_t	end;
	vm_prot_t	new_prot;
	boolean_t	set_max;
{
	vm_map_entry_t		current;
	vm_map_entry_t		entry;

	vm_map_lock(map);

	VM_MAP_RANGE_CHECK(map, start, end);

	if (vm_map_lookup_entry(map, start, &entry)) {
		vm_map_clip_start(map, entry, start);
	}
	 else
		entry = entry->vme_next;

	/*
	 *	Make a first pass to check for protection
	 *	violations.
	 */

	current = entry;
	while ((current != vm_map_to_entry(map)) &&
	       (current->vme_start < end)) {

		if (current->is_sub_map) {
			vm_map_unlock(map);
			return(KERN_INVALID_ARGUMENT);
		}
		if ((new_prot & (VM_PROT_NOTIFY | current->max_protection))
		    != new_prot) {
		       vm_map_unlock(map);
		       return(KERN_PROTECTION_FAILURE);
		}

		current = current->vme_next;
	}

	/*
	 *	Go back and fix up protections.
	 *	[Note that clipping is not necessary the second time.]
	 */

	current = entry;

	while ((current != vm_map_to_entry(map)) &&
	       (current->vme_start < end)) {

		vm_prot_t	old_prot;

		vm_map_clip_end(map, current, end);

		old_prot = current->protection;
		if (set_max)
			current->protection =
				(current->max_protection = new_prot) &
					old_prot;
		else
			current->protection = new_prot;

		/*
		 *	Update physical map if necessary.
		 */

		if (current->protection != old_prot) {
			pmap_protect(map->pmap, current->vme_start,
					current->vme_end,
					current->protection);
		}
		current = current->vme_next;
	}

	vm_map_unlock(map);
	return(KERN_SUCCESS);
}

/*
 *	vm_map_inherit:
 *
 *	Sets the inheritance of the specified address
 *	range in the target map.  Inheritance
 *	affects how the map will be shared with
 *	child maps at the time of vm_map_fork.
 */
kern_return_t vm_map_inherit(map, start, end, new_inheritance)
	vm_map_t	map;
	vm_offset_t	start;
	vm_offset_t	end;
	vm_inherit_t	new_inheritance;
{
	vm_map_entry_t	entry;
	vm_map_entry_t	temp_entry;

	vm_map_lock(map);

	VM_MAP_RANGE_CHECK(map, start, end);

	if (vm_map_lookup_entry(map, start, &temp_entry)) {
		entry = temp_entry;
		vm_map_clip_start(map, entry, start);
	}
	else
		entry = temp_entry->vme_next;

	while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
		vm_map_clip_end(map, entry, end);

		entry->inheritance = new_inheritance;

		entry = entry->vme_next;
	}

	vm_map_unlock(map);
	return(KERN_SUCCESS);
}

/*
 *	vm_map_pageable_common:
 *
 *	Sets the pageability of the specified address
 *	range in the target map.  Regions specified
 *	as not pageable require locked-down physical
 *	memory and physical page maps.  access_type indicates
 *	types of accesses that must not generate page faults.
 *	This is checked against protection of memory being locked-down.
 *	access_type of VM_PROT_NONE makes memory pageable.
 *
 *	The map must not be locked, but a reference
 *	must remain to the map throughout the call.
 *
 *	Callers should use macros in vm/vm_map.h (i.e. vm_map_pageable,
 *	or vm_map_pageable_user); don't call vm_map_pageable directly.
 */
kern_return_t vm_map_pageable_common(map, start, end, access_type, user_wire)
	vm_map_t	map;
	vm_offset_t	start;
	vm_offset_t	end;
	vm_prot_t	access_type;
	boolean_t	user_wire;
{
	vm_map_entry_t		entry;
	vm_map_entry_t		start_entry;

	vm_map_lock(map);

	VM_MAP_RANGE_CHECK(map, start, end);

	if (vm_map_lookup_entry(map, start, &start_entry)) {
		entry = start_entry;
		/*
		 *	vm_map_clip_start will be done later.
		 */
	}
	else {
		/*
		 *	Start address is not in map; this is fatal.
		 */
		vm_map_unlock(map);
		return(KERN_FAILURE);
	}

	/*
	 *	Actions are rather different for wiring and unwiring,
	 *	so we have two separate cases.
	 */

	if (access_type == VM_PROT_NONE) {

		vm_map_clip_start(map, entry, start);

		/*
		 *	Unwiring.  First ensure that the range to be
		 *	unwired is really wired down.
		 */
		while ((entry != vm_map_to_entry(map)) &&
		       (entry->vme_start < end)) {

		    if ((entry->wired_count == 0) ||
		    	((entry->vme_end < end) &&
			 ((entry->vme_next == vm_map_to_entry(map)) ||
			  (entry->vme_next->vme_start > entry->vme_end))) ||
			(user_wire && (entry->user_wired_count == 0))) {
			    vm_map_unlock(map);
			    return(KERN_INVALID_ARGUMENT);
		    }
		    entry = entry->vme_next;
		}

		/*
		 *	Now decrement the wiring count for each region.
		 *	If a region becomes completely unwired,
		 *	unwire its physical pages and mappings.
		 */
		entry = start_entry;
		while ((entry != vm_map_to_entry(map)) &&
		       (entry->vme_start < end)) {
		    vm_map_clip_end(map, entry, end);

		    if (user_wire) {
			if (--(entry->user_wired_count) == 0)
			    entry->wired_count--;
		    }
		    else {
			entry->wired_count--;
		    }

		    if (entry->wired_count == 0)
			vm_fault_unwire(map, entry);

		    entry = entry->vme_next;
		}
	}

	else {
		/*
		 *	Wiring.  We must do this in two passes:
		 *
		 *	1.  Holding the write lock, we create any shadow
		 *	    or zero-fill objects that need to be created.
		 *	    Then we clip each map entry to the region to be
		 *	    wired and increment its wiring count.  We
		 *	    create objects before clipping the map entries
		 *	    to avoid object proliferation.
		 *
		 *	2.  We downgrade to a read lock, and call
		 *	    vm_fault_wire to fault in the pages for any
		 *	    newly wired area (wired_count is 1).
		 *
		 *	Downgrading to a read lock for vm_fault_wire avoids
		 *	a possible deadlock with another thread that may have
		 *	faulted on one of the pages to be wired (it would mark
		 *	the page busy, blocking us, then in turn block on the
		 *	map lock that we hold).  Because of problems in the
		 *	recursive lock package, we cannot upgrade to a write
		 *	lock in vm_map_lookup.  Thus, any actions that require
		 *	the write lock must be done beforehand.  Because we
		 *	keep the read lock on the map, the copy-on-write
		 *	status of the entries we modify here cannot change.
		 */

		/*
		 *	Pass 1.
		 */
		while ((entry != vm_map_to_entry(map)) &&
		       (entry->vme_start < end)) {
		    vm_map_clip_end(map, entry, end);

		    if (entry->wired_count == 0) {

			/*
			 *	Perform actions of vm_map_lookup that need
			 *	the write lock on the map: create a shadow
			 *	object for a copy-on-write region, or an
			 *	object for a zero-fill region.
			 */
			if (entry->needs_copy &&
			    ((entry->protection & VM_PROT_WRITE) != 0)) {

				vm_object_shadow(&entry->object.vm_object,
						&entry->offset,
						(vm_size_t)(entry->vme_end
							- entry->vme_start));
				entry->needs_copy = FALSE;
			}
			if (entry->object.vm_object == VM_OBJECT_NULL) {
				entry->object.vm_object =
				        vm_object_allocate(
					    (vm_size_t)(entry->vme_end
				    			- entry->vme_start));
				entry->offset = (vm_offset_t)0;
			}
		    }
		    vm_map_clip_start(map, entry, start);
		    vm_map_clip_end(map, entry, end);

		    if (user_wire) {
			if ((entry->user_wired_count)++ == 0)
			    entry->wired_count++;
		    }
		    else {
			entry->wired_count++;
		    }

		    /*
		     *	Check for holes and protection mismatch.
		     *  Holes: Next entry should be contiguous unless
		     *		this is the end of the region.
		     *	Protection: Access requested must be allowed.
		     */
		    if (((entry->vme_end < end) &&
			 ((entry->vme_next == vm_map_to_entry(map)) ||
			  (entry->vme_next->vme_start > entry->vme_end))) ||
			((entry->protection & access_type) != access_type)) {
			    /*
			     *	Found a hole or protection problem.
			     *	Object creation actions
			     *	do not need to be undone, but the
			     *	wired counts need to be restored.
			     */
			    while ((entry != vm_map_to_entry(map)) &&
				(entry->vme_end > start)) {
				    if (user_wire) {
					if (--(entry->user_wired_count) == 0)
					    entry->wired_count--;
				    }
				    else {
				       entry->wired_count--;
				    }

				    entry = entry->vme_prev;
			    }

			    vm_map_unlock(map);
			    return(KERN_FAILURE);
		    }
		    entry = entry->vme_next;
		}

		/*
		 *	Pass 2.
		 */

		/*
		 * HACK HACK HACK HACK
		 *
		 * If we are wiring in the kernel map or a submap of it,
		 * unlock the map to avoid deadlocks.  We trust that the
		 * kernel threads are well-behaved, and therefore will
		 * not do anything destructive to this region of the map
		 * while we have it unlocked.  We cannot trust user threads
		 * to do the same.
		 *
		 * HACK HACK HACK HACK
		 */
		if (vm_map_pmap(map) == kernel_pmap) {
		    vm_map_unlock(map);		/* trust me ... */
		}
		else {
		    vm_map_lock_set_recursive(map);
		    vm_map_lock_write_to_read(map);
		}

		entry = start_entry;
		while (entry != vm_map_to_entry(map) &&
			entry->vme_start < end) {
		    /*
		     *	Wiring cases:
		     *	    Kernel: wired == 1 && user_wired == 0
		     *	    User:   wired == 1 && user_wired == 1
		     *
		     *  Don't need to wire if either is > 1.  wired = 0 &&
		     *	user_wired == 1 can't happen.
		     */

		    /*
		     *	XXX This assumes that the faults always succeed.
		     */
		    if ((entry->wired_count == 1) &&
			(entry->user_wired_count <= 1)) {
			    vm_fault_wire(map, entry);
		    }
		    entry = entry->vme_next;
		}

		if (vm_map_pmap(map) == kernel_pmap) {
		    vm_map_lock(map);
		}
		else {
		    vm_map_lock_clear_recursive(map);
		}
	}

	vm_map_unlock(map);

	return(KERN_SUCCESS);
}

/*
 *	vm_map_entry_delete:	[ internal use only ]
 *
 *	Deallocate the given entry from the target map.
 */
void vm_map_entry_delete(map, entry)
	vm_map_t	map;
	vm_map_entry_t	entry;
{
	vm_offset_t		s, e;
	vm_object_t		object;
	extern vm_object_t	kernel_object;

	s = entry->vme_start;
	e = entry->vme_end;

	/*Check if projected buffer*/
	if (map != kernel_map && entry->projected_on != 0) {
	  /*Check if projected kernel entry is persistent;
	    may only manipulate directly if it is*/
	  if (entry->projected_on->projected_on == 0)
	    entry->wired_count = 0;    /*Avoid unwire fault*/
	  else
	    return;
	}

	/*
	 *	Get the object.    Null objects cannot have pmap entries.
	 */

	if ((object = entry->object.vm_object) != VM_OBJECT_NULL) {

	    /*
	     *	Unwire before removing addresses from the pmap;
	     *	otherwise, unwiring will put the entries back in
	     *	the pmap.
	     */

	    if (entry->wired_count != 0) {
		vm_fault_unwire(map, entry);
		entry->wired_count = 0;
		entry->user_wired_count = 0;
	    }

	    /*
	     *	If the object is shared, we must remove
	     *	*all* references to this data, since we can't
	     *	find all of the physical maps which are sharing
	     *	it.
	     */

	    if (object == kernel_object) {
		vm_object_lock(object);
		vm_object_page_remove(object, entry->offset,
				entry->offset + (e - s));
		vm_object_unlock(object);
	    } else if (entry->is_shared) {
		vm_object_pmap_remove(object,
				 entry->offset,
				 entry->offset + (e - s));
	    }
	    else {
		pmap_remove(map->pmap, s, e);
	    }
        }

	/*
	 *	Deallocate the object only after removing all
	 *	pmap entries pointing to its pages.
	 */

	if (entry->is_sub_map)
		vm_map_deallocate(entry->object.sub_map);
	else
	 	vm_object_deallocate(entry->object.vm_object);

	vm_map_entry_unlink(map, entry);
	map->size -= e - s;

	vm_map_entry_dispose(map, entry);
}

/*
 *	vm_map_delete:	[ internal use only ]
 *
 *	Deallocates the given address range from the target
 *	map.
 */

kern_return_t vm_map_delete(map, start, end)
	vm_map_t		map;
	vm_offset_t		start;
	vm_offset_t		end;
{
	vm_map_entry_t		entry;
	vm_map_entry_t		first_entry;

	/*
	 *	Find the start of the region, and clip it
	 */

	if (!vm_map_lookup_entry(map, start, &first_entry))
		entry = first_entry->vme_next;
	else {
		entry = first_entry;
		vm_map_clip_start(map, entry, start);

		/*
		 *	Fix the lookup hint now, rather than each
		 *	time though the loop.
		 */

		SAVE_HINT(map, entry->vme_prev);
	}

	/*
	 *	Save the free space hint
	 */

	if (map->first_free->vme_start >= start)
		map->first_free = entry->vme_prev;

	/*
	 *	Step through all entries in this region
	 */

	while ((entry != vm_map_to_entry(map)) && (entry->vme_start < end)) {
		vm_map_entry_t		next;

		vm_map_clip_end(map, entry, end);

		/*
		 *	If the entry is in transition, we must wait
		 *	for it to exit that state.  It could be clipped
		 *	while we leave the map unlocked.
		 */
                if(entry->in_transition) {
                        /*
                         * Say that we are waiting, and wait for entry.
                         */
                        entry->needs_wakeup = TRUE;
                        vm_map_entry_wait(map, FALSE);
                        vm_map_lock(map);

                        /*
                         * The entry could have been clipped or it
                         * may not exist anymore.  look it up again.
                         */
                        if(!vm_map_lookup_entry(map, start, &entry)) {
				entry = entry->vme_next;
			}
			continue;
		}

		next = entry->vme_next;

		vm_map_entry_delete(map, entry);
		entry = next;
	}

	if (map->wait_for_space)
		thread_wakeup((event_t) map);

	return(KERN_SUCCESS);
}

/*
 *	vm_map_remove:
 *
 *	Remove the given address range from the target map.
 *	This is the exported form of vm_map_delete.
 */
kern_return_t vm_map_remove(map, start, end)
	vm_map_t	map;
	vm_offset_t	start;
	vm_offset_t	end;
{
	kern_return_t	result;

	vm_map_lock(map);
	VM_MAP_RANGE_CHECK(map, start, end);
	result = vm_map_delete(map, start, end);
	vm_map_unlock(map);

	return(result);
}


/*
 *	vm_map_copy_steal_pages:
 *
 *	Steal all the pages from a vm_map_copy page_list by copying ones
 *	that have not already been stolen.
 */
void
vm_map_copy_steal_pages(copy)
vm_map_copy_t	copy;
{
	vm_page_t	m, new_m;
	int		i;
	vm_object_t	object;

	for (i = 0; i < copy->cpy_npages; i++) {

		/*
		 *	If the page is not tabled, then it's already stolen.
		 */
		m = copy->cpy_page_list[i];
		if (!m->tabled)
			continue;

		/*
		 *	Page was not stolen,  get a new
		 *	one and do the copy now.
		 */
		while ((new_m = vm_page_grab(FALSE)) == VM_PAGE_NULL) {
			VM_PAGE_WAIT((void(*)()) 0);
		}

		vm_page_copy(m, new_m);

		object = m->object;
		vm_object_lock(object);
		vm_page_lock_queues();
		if (!m->active && !m->inactive)
			vm_page_activate(m);
		vm_page_unlock_queues();
		PAGE_WAKEUP_DONE(m);
		vm_object_paging_end(object);
		vm_object_unlock(object);

		copy->cpy_page_list[i] = new_m;
	}
}

/*
 *	vm_map_copy_page_discard:
 *
 *	Get rid of the pages in a page_list copy.  If the pages are
 *	stolen, they are freed.  If the pages are not stolen, they
 *	are unbusied, and associated state is cleaned up.
 */
void vm_map_copy_page_discard(copy)
vm_map_copy_t	copy;
{
	while (copy->cpy_npages > 0) {
		vm_page_t	m;

		if((m = copy->cpy_page_list[--(copy->cpy_npages)]) !=
		    VM_PAGE_NULL) {

			/*
			 *	If it's not in the table, then it's
			 *	a stolen page that goes back
			 *	to the free list.  Else it belongs
			 *	to some object, and we hold a
			 *	paging reference on that object.
			 */
			if (!m->tabled) {
				VM_PAGE_FREE(m);
			}
			else {
				vm_object_t	object;

				object = m->object;

				vm_object_lock(object);
				vm_page_lock_queues();
				if (!m->active && !m->inactive)
					vm_page_activate(m);
				vm_page_unlock_queues();

				PAGE_WAKEUP_DONE(m);
				vm_object_paging_end(object);
				vm_object_unlock(object);
			}
		}
	}
}

/*
 *	Routine:	vm_map_copy_discard
 *
 *	Description:
 *		Dispose of a map copy object (returned by
 *		vm_map_copyin).
 */
void
vm_map_copy_discard(copy)
	vm_map_copy_t	copy;
{
free_next_copy:
	if (copy == VM_MAP_COPY_NULL)
		return;

	switch (copy->type) {
	case VM_MAP_COPY_ENTRY_LIST:
		while (vm_map_copy_first_entry(copy) !=
					vm_map_copy_to_entry(copy)) {
			vm_map_entry_t	entry = vm_map_copy_first_entry(copy);

			vm_map_copy_entry_unlink(copy, entry);
			vm_object_deallocate(entry->object.vm_object);
			vm_map_copy_entry_dispose(copy, entry);
		}
		break;
        case VM_MAP_COPY_OBJECT:
		vm_object_deallocate(copy->cpy_object);
		break;
	case VM_MAP_COPY_PAGE_LIST:

		/*
		 *	To clean this up, we have to unbusy all the pages
		 *	and release the paging references in their objects.
		 */
		if (copy->cpy_npages > 0)
			vm_map_copy_page_discard(copy);

		/*
		 *	If there's a continuation, abort it.  The
		 *	abort routine releases any storage.
		 */
		if (vm_map_copy_has_cont(copy)) {

			/*
			 *	Special case: recognize
			 *	vm_map_copy_discard_cont and optimize
			 *	here to avoid tail recursion.
			 */
			if (copy->cpy_cont == vm_map_copy_discard_cont) {
				vm_map_copy_t	new_copy;

				new_copy = (vm_map_copy_t) copy->cpy_cont_args;
				kmem_cache_free(&vm_map_copy_cache, (vm_offset_t) copy);
				copy = new_copy;
				goto free_next_copy;
			}
			else {
				vm_map_copy_abort_cont(copy);
			}
		}

		break;
	}
	kmem_cache_free(&vm_map_copy_cache, (vm_offset_t) copy);
}

/*
 *	Routine:	vm_map_copy_copy
 *
 *	Description:
 *			Move the information in a map copy object to
 *			a new map copy object, leaving the old one
 *			empty.
 *
 *			This is used by kernel routines that need
 *			to look at out-of-line data (in copyin form)
 *			before deciding whether to return SUCCESS.
 *			If the routine returns FAILURE, the original
 *			copy object will be deallocated; therefore,
 *			these routines must make a copy of the copy
 *			object and leave the original empty so that
 *			deallocation will not fail.
 */
vm_map_copy_t
vm_map_copy_copy(copy)
	vm_map_copy_t	copy;
{
	vm_map_copy_t	new_copy;

	if (copy == VM_MAP_COPY_NULL)
		return VM_MAP_COPY_NULL;

	/*
	 * Allocate a new copy object, and copy the information
	 * from the old one into it.
	 */

	new_copy = (vm_map_copy_t) kmem_cache_alloc(&vm_map_copy_cache);
	*new_copy = *copy;

	if (copy->type == VM_MAP_COPY_ENTRY_LIST) {
		/*
		 * The links in the entry chain must be
		 * changed to point to the new copy object.
		 */
		vm_map_copy_first_entry(copy)->vme_prev
			= vm_map_copy_to_entry(new_copy);
		vm_map_copy_last_entry(copy)->vme_next
			= vm_map_copy_to_entry(new_copy);
	}

	/*
	 * Change the old copy object into one that contains
	 * nothing to be deallocated.
	 */
	copy->type = VM_MAP_COPY_OBJECT;
	copy->cpy_object = VM_OBJECT_NULL;

	/*
	 * Return the new object.
	 */
	return new_copy;
}

/*
 *	Routine:	vm_map_copy_discard_cont
 *
 *	Description:
 *		A version of vm_map_copy_discard that can be called
 *		as a continuation from a vm_map_copy page list.
 */
kern_return_t	vm_map_copy_discard_cont(cont_args, copy_result)
vm_map_copyin_args_t	cont_args;
vm_map_copy_t		*copy_result;	/* OUT */
{
	vm_map_copy_discard((vm_map_copy_t) cont_args);
	if (copy_result != (vm_map_copy_t *)0)
		*copy_result = VM_MAP_COPY_NULL;
	return(KERN_SUCCESS);
}

/*
 *	Routine:	vm_map_copy_overwrite
 *
 *	Description:
 *		Copy the memory described by the map copy
 *		object (copy; returned by vm_map_copyin) onto
 *		the specified destination region (dst_map, dst_addr).
 *		The destination must be writeable.
 *
 *		Unlike vm_map_copyout, this routine actually
 *		writes over previously-mapped memory.  If the
 *		previous mapping was to a permanent (user-supplied)
 *		memory object, it is preserved.
 *
 *		The attributes (protection and inheritance) of the
 *		destination region are preserved.
 *
 *		If successful, consumes the copy object.
 *		Otherwise, the caller is responsible for it.
 *
 *	Implementation notes:
 *		To overwrite temporary virtual memory, it is
 *		sufficient to remove the previous mapping and insert
 *		the new copy.  This replacement is done either on
 *		the whole region (if no permanent virtual memory
 *		objects are embedded in the destination region) or
 *		in individual map entries.
 *
 *		To overwrite permanent virtual memory, it is
 *		necessary to copy each page, as the external
 *		memory management interface currently does not
 *		provide any optimizations.
 *
 *		Once a page of permanent memory has been overwritten,
 *		it is impossible to interrupt this function; otherwise,
 *		the call would be neither atomic nor location-independent.
 *		The kernel-state portion of a user thread must be
 *		interruptible.
 *
 *		It may be expensive to forward all requests that might
 *		overwrite permanent memory (vm_write, vm_copy) to
 *		uninterruptible kernel threads.  This routine may be
 *		called by interruptible threads; however, success is
 *		not guaranteed -- if the request cannot be performed
 *		atomically and interruptibly, an error indication is
 *		returned.
 */
kern_return_t vm_map_copy_overwrite(dst_map, dst_addr, copy, interruptible)
	vm_map_t	dst_map;
	vm_offset_t	dst_addr;
	vm_map_copy_t	copy;
	boolean_t	interruptible;
{
	vm_size_t	size;
	vm_offset_t	start;
	vm_map_entry_t	tmp_entry;
	vm_map_entry_t	entry;

	boolean_t	contains_permanent_objects = FALSE;

	interruptible = FALSE;	/* XXX */

	/*
	 *	Check for null copy object.
	 */

	if (copy == VM_MAP_COPY_NULL)
		return(KERN_SUCCESS);

	/*
	 *	Only works for entry lists at the moment.  Will
	 *      support page lists LATER.
	 */

	assert(copy->type == VM_MAP_COPY_ENTRY_LIST);

	/*
	 *	Currently this routine only handles page-aligned
	 *	regions.  Eventually, it should handle misalignments
	 *	by actually copying pages.
	 */

	if (!page_aligned(copy->offset) ||
	    !page_aligned(copy->size) ||
	    !page_aligned(dst_addr))
		return(KERN_INVALID_ARGUMENT);

	size = copy->size;

	if (size == 0) {
		vm_map_copy_discard(copy);
		return(KERN_SUCCESS);
	}

	/*
	 *	Verify that the destination is all writeable
	 *	initially.
	 */
start_pass_1:
	vm_map_lock(dst_map);
	if (!vm_map_lookup_entry(dst_map, dst_addr, &tmp_entry)) {
		vm_map_unlock(dst_map);
		return(KERN_INVALID_ADDRESS);
	}
	vm_map_clip_start(dst_map, tmp_entry, dst_addr);
	for (entry = tmp_entry;;) {
		vm_size_t	sub_size = (entry->vme_end - entry->vme_start);
		vm_map_entry_t	next = entry->vme_next;

		if ( ! (entry->protection & VM_PROT_WRITE)) {
			vm_map_unlock(dst_map);
			return(KERN_PROTECTION_FAILURE);
		}

		/*
		 *	If the entry is in transition, we must wait
		 *	for it to exit that state.  Anything could happen
		 *	when we unlock the map, so start over.
		 */
                if (entry->in_transition) {

                        /*
                         * Say that we are waiting, and wait for entry.
                         */
                        entry->needs_wakeup = TRUE;
                        vm_map_entry_wait(dst_map, FALSE);

			goto start_pass_1;
		}

		if (size <= sub_size)
			break;

		if ((next == vm_map_to_entry(dst_map)) ||
		    (next->vme_start != entry->vme_end)) {
			vm_map_unlock(dst_map);
			return(KERN_INVALID_ADDRESS);
		}


		/*
		 *	Check for permanent objects in the destination.
		 */

		if ((entry->object.vm_object != VM_OBJECT_NULL) &&
			   !entry->object.vm_object->temporary)
			contains_permanent_objects = TRUE;

		size -= sub_size;
		entry = next;
	}

	/*
	 *	If there are permanent objects in the destination, then
	 *	the copy cannot be interrupted.
	 */

	if (interruptible && contains_permanent_objects) {
		vm_map_unlock(dst_map);
		return(KERN_FAILURE);	/* XXX */
	}

	/*
	 * XXXO	If there are no permanent objects in the destination,
	 * XXXO	and the source and destination map entry caches match,
	 * XXXO and the destination map entry is not shared,
	 * XXXO	then the map entries can be deleted and replaced
	 * XXXO	with those from the copy.  The following code is the
	 * XXXO	basic idea of what to do, but there are lots of annoying
	 * XXXO	little details about getting protection and inheritance
	 * XXXO	right.  Should add protection, inheritance, and sharing checks
	 * XXXO	to the above pass and make sure that no wiring is involved.
	 */
/*
 *	if (!contains_permanent_objects &&
 *	    copy->cpy_hdr.entries_pageable == dst_map->hdr.entries_pageable) {
 *
 *		 *
 *		 *	Run over copy and adjust entries.  Steal code
 *		 *	from vm_map_copyout() to do this.
 *		 *
 *
 *		tmp_entry = tmp_entry->vme_prev;
 *		vm_map_delete(dst_map, dst_addr, dst_addr + copy->size);
 *		vm_map_copy_insert(dst_map, tmp_entry, copy);
 *
 *		vm_map_unlock(dst_map);
 *		vm_map_copy_discard(copy);
 *	}
 */
	/*
	 *
	 *	Make a second pass, overwriting the data
	 *	At the beginning of each loop iteration,
	 *	the next entry to be overwritten is "tmp_entry"
	 *	(initially, the value returned from the lookup above),
	 *	and the starting address expected in that entry
	 *	is "start".
	 */

	start = dst_addr;

	while (vm_map_copy_first_entry(copy) != vm_map_copy_to_entry(copy)) {
		vm_map_entry_t	copy_entry = vm_map_copy_first_entry(copy);
		vm_size_t	copy_size = (copy_entry->vme_end - copy_entry->vme_start);
		vm_object_t	object;

		entry = tmp_entry;
		size = (entry->vme_end - entry->vme_start);
		/*
		 *	Make sure that no holes popped up in the
		 *	address map, and that the protection is
		 *	still valid, in case the map was unlocked
		 *	earlier.
		 */

		if (entry->vme_start != start) {
			vm_map_unlock(dst_map);
			return(KERN_INVALID_ADDRESS);
		}
		assert(entry != vm_map_to_entry(dst_map));

		/*
		 *	Check protection again
		 */

		if ( ! (entry->protection & VM_PROT_WRITE)) {
			vm_map_unlock(dst_map);
			return(KERN_PROTECTION_FAILURE);
		}

		/*
		 *	Adjust to source size first
		 */

		if (copy_size < size) {
			vm_map_clip_end(dst_map, entry, entry->vme_start + copy_size);
			size = copy_size;
		}

		/*
		 *	Adjust to destination size
		 */

		if (size < copy_size) {
			vm_map_copy_clip_end(copy, copy_entry,
				copy_entry->vme_start + size);
			copy_size = size;
		}

		assert((entry->vme_end - entry->vme_start) == size);
		assert((tmp_entry->vme_end - tmp_entry->vme_start) == size);
		assert((copy_entry->vme_end - copy_entry->vme_start) == size);

		/*
		 *	If the destination contains temporary unshared memory,
		 *	we can perform the copy by throwing it away and
		 *	installing the source data.
		 */

		object = entry->object.vm_object;
		if (!entry->is_shared &&
		    ((object == VM_OBJECT_NULL) || object->temporary)) {
			vm_object_t	old_object = entry->object.vm_object;
			vm_offset_t	old_offset = entry->offset;

			entry->object = copy_entry->object;
			entry->offset = copy_entry->offset;
			entry->needs_copy = copy_entry->needs_copy;
			entry->wired_count = 0;
			entry->user_wired_count = 0;

			vm_map_copy_entry_unlink(copy, copy_entry);
			vm_map_copy_entry_dispose(copy, copy_entry);

			vm_object_pmap_protect(
				old_object,
				old_offset,
				size,
				dst_map->pmap,
				tmp_entry->vme_start,
				VM_PROT_NONE);

			vm_object_deallocate(old_object);

			/*
			 *	Set up for the next iteration.  The map
			 *	has not been unlocked, so the next
			 *	address should be at the end of this
			 *	entry, and the next map entry should be
			 *	the one following it.
			 */

			start = tmp_entry->vme_end;
			tmp_entry = tmp_entry->vme_next;
		} else {
			vm_map_version_t	version;
			vm_object_t		dst_object = entry->object.vm_object;
			vm_offset_t		dst_offset = entry->offset;
			kern_return_t		r;

			/*
			 *	Take an object reference, and record
			 *	the map version information so that the
			 *	map can be safely unlocked.
			 */

			vm_object_reference(dst_object);

			version.main_timestamp = dst_map->timestamp;

			vm_map_unlock(dst_map);

			/*
			 *	Copy as much as possible in one pass
			 */

			copy_size = size;
			r = vm_fault_copy(
					copy_entry->object.vm_object,
					copy_entry->offset,
					&copy_size,
					dst_object,
					dst_offset,
					dst_map,
					&version,
					FALSE /* XXX interruptible */ );

			/*
			 *	Release the object reference
			 */

			vm_object_deallocate(dst_object);

			/*
			 *	If a hard error occurred, return it now
			 */

			if (r != KERN_SUCCESS)
				return(r);

			if (copy_size != 0) {
				/*
				 *	Dispose of the copied region
				 */

				vm_map_copy_clip_end(copy, copy_entry,
					copy_entry->vme_start + copy_size);
				vm_map_copy_entry_unlink(copy, copy_entry);
				vm_object_deallocate(copy_entry->object.vm_object);
				vm_map_copy_entry_dispose(copy, copy_entry);
			}

			/*
			 *	Pick up in the destination map where we left off.
			 *
			 *	Use the version information to avoid a lookup
			 *	in the normal case.
			 */

			start += copy_size;
			vm_map_lock(dst_map);
			if ((version.main_timestamp + 1) == dst_map->timestamp) {
				/* We can safely use saved tmp_entry value */

				vm_map_clip_end(dst_map, tmp_entry, start);
				tmp_entry = tmp_entry->vme_next;
			} else {
				/* Must do lookup of tmp_entry */

				if (!vm_map_lookup_entry(dst_map, start, &tmp_entry)) {
					vm_map_unlock(dst_map);
					return(KERN_INVALID_ADDRESS);
				}
				vm_map_clip_start(dst_map, tmp_entry, start);
			}
		}

	}
	vm_map_unlock(dst_map);

	/*
	 *	Throw away the vm_map_copy object
	 */
	vm_map_copy_discard(copy);

	return(KERN_SUCCESS);
}

/*
 *	Macro:		vm_map_copy_insert
 *
 *	Description:
 *		Link a copy chain ("copy") into a map at the
 *		specified location (after "where").
 *	Side effects:
 *		The copy chain is destroyed.
 *	Warning:
 *		The arguments are evaluated multiple times.
 */
#define	vm_map_copy_insert(map, where, copy)				\
	MACRO_BEGIN							\
	struct rbtree_node *node, *tmp;					\
	rbtree_for_each_remove(&(copy)->cpy_hdr.tree, node, tmp)	\
		rbtree_insert(&(map)->hdr.tree, node,			\
			      vm_map_entry_cmp_insert);			\
	(((where)->vme_next)->vme_prev = vm_map_copy_last_entry(copy))	\
		->vme_next = ((where)->vme_next);			\
	((where)->vme_next = vm_map_copy_first_entry(copy))		\
		->vme_prev = (where);					\
	(map)->hdr.nentries += (copy)->cpy_hdr.nentries;		\
	kmem_cache_free(&vm_map_copy_cache, (vm_offset_t) copy);	\
	MACRO_END

/*
 *	Routine:	vm_map_copyout
 *
 *	Description:
 *		Copy out a copy chain ("copy") into newly-allocated
 *		space in the destination map.
 *
 *		If successful, consumes the copy object.
 *		Otherwise, the caller is responsible for it.
 */
kern_return_t vm_map_copyout(dst_map, dst_addr, copy)
	vm_map_t	dst_map;
	vm_offset_t	*dst_addr;	/* OUT */
	vm_map_copy_t	copy;
{
	vm_size_t	size;
	vm_size_t	adjustment;
	vm_offset_t	start;
	vm_offset_t	vm_copy_start;
	vm_map_entry_t	last;
	vm_map_entry_t	entry;

	/*
	 *	Check for null copy object.
	 */

	if (copy == VM_MAP_COPY_NULL) {
		*dst_addr = 0;
		return(KERN_SUCCESS);
	}

	/*
	 *	Check for special copy object, created
	 *	by vm_map_copyin_object.
	 */

	if (copy->type == VM_MAP_COPY_OBJECT) {
		vm_object_t object = copy->cpy_object;
		vm_size_t offset = copy->offset;
		vm_size_t tmp_size = copy->size;
		kern_return_t kr;

		*dst_addr = 0;
		kr = vm_map_enter(dst_map, dst_addr, tmp_size,
				  (vm_offset_t) 0, TRUE,
				  object, offset, FALSE,
				  VM_PROT_DEFAULT, VM_PROT_ALL,
				  VM_INHERIT_DEFAULT);
		if (kr != KERN_SUCCESS)
			return(kr);
		kmem_cache_free(&vm_map_copy_cache, (vm_offset_t) copy);
		return(KERN_SUCCESS);
	}

	if (copy->type == VM_MAP_COPY_PAGE_LIST)
		return(vm_map_copyout_page_list(dst_map, dst_addr, copy));

	/*
	 *	Find space for the data
	 */

	vm_copy_start = trunc_page(copy->offset);
	size =	round_page(copy->offset + copy->size) - vm_copy_start;

 StartAgain: ;

	vm_map_lock(dst_map);
	start = ((last = dst_map->first_free) == vm_map_to_entry(dst_map)) ?
		vm_map_min(dst_map) : last->vme_end;

	while (TRUE) {
		vm_map_entry_t	next = last->vme_next;
		vm_offset_t	end = start + size;

		if ((end > dst_map->max_offset) || (end < start)) {
			if (dst_map->wait_for_space) {
				if (size <= (dst_map->max_offset - dst_map->min_offset)) {
					assert_wait((event_t) dst_map, TRUE);
					vm_map_unlock(dst_map);
					thread_block((void (*)()) 0);
					goto StartAgain;
				}
			}
			vm_map_unlock(dst_map);
			printf_once("no more room for vm_map_copyout in %p\n", dst_map);
			return(KERN_NO_SPACE);
		}

		if ((next == vm_map_to_entry(dst_map)) ||
		    (next->vme_start >= end))
			break;

		last = next;
		start = last->vme_end;
	}

	/*
	 *	Since we're going to just drop the map
	 *	entries from the copy into the destination
	 *	map, they must come from the same pool.
	 */

	if (copy->cpy_hdr.entries_pageable != dst_map->hdr.entries_pageable) {
	    /*
	     * Mismatches occur when dealing with the default
	     * pager.
	     */
	    kmem_cache_t	old_cache;
	    vm_map_entry_t	next, new;

	    /*
	     * Find the cache that the copies were allocated from
	     */
	    old_cache = (copy->cpy_hdr.entries_pageable)
			? &vm_map_entry_cache
			: &vm_map_kentry_cache;
	    entry = vm_map_copy_first_entry(copy);

	    /*
	     * Reinitialize the copy so that vm_map_copy_entry_link
	     * will work.
	     */
	    copy->cpy_hdr.nentries = 0;
	    copy->cpy_hdr.entries_pageable = dst_map->hdr.entries_pageable;
	    vm_map_copy_first_entry(copy) =
	     vm_map_copy_last_entry(copy) =
		vm_map_copy_to_entry(copy);

	    /*
	     * Copy each entry.
	     */
	    while (entry != vm_map_copy_to_entry(copy)) {
		new = vm_map_copy_entry_create(copy);
		vm_map_entry_copy_full(new, entry);
		vm_map_copy_entry_link(copy,
				vm_map_copy_last_entry(copy),
				new);
		next = entry->vme_next;
		kmem_cache_free(old_cache, (vm_offset_t) entry);
		entry = next;
	    }
	}

	/*
	 *	Adjust the addresses in the copy chain, and
	 *	reset the region attributes.
	 */

	adjustment = start - vm_copy_start;
	for (entry = vm_map_copy_first_entry(copy);
	     entry != vm_map_copy_to_entry(copy);
	     entry = entry->vme_next) {
		entry->vme_start += adjustment;
		entry->vme_end += adjustment;

		entry->inheritance = VM_INHERIT_DEFAULT;
		entry->protection = VM_PROT_DEFAULT;
		entry->max_protection = VM_PROT_ALL;
		entry->projected_on = 0;

		/*
		 * If the entry is now wired,
		 * map the pages into the destination map.
		 */
		if (entry->wired_count != 0) {
		    vm_offset_t 	va;
		    vm_offset_t		offset;
		    vm_object_t 	object;

		    object = entry->object.vm_object;
		    offset = entry->offset;
		    va = entry->vme_start;

		    pmap_pageable(dst_map->pmap,
				  entry->vme_start,
				  entry->vme_end,
				  TRUE);

		    while (va < entry->vme_end) {
			vm_page_t	m;

			/*
			 * Look up the page in the object.
			 * Assert that the page will be found in the
			 * top object:
			 * either
			 *	the object was newly created by
			 *	vm_object_copy_slowly, and has
			 *	copies of all of the pages from
			 *	the source object
			 * or
			 *	the object was moved from the old
			 *	map entry; because the old map
			 *	entry was wired, all of the pages
			 *	were in the top-level object.
			 *	(XXX not true if we wire pages for
			 *	 reading)
			 */
			vm_object_lock(object);
			vm_object_paging_begin(object);

			m = vm_page_lookup(object, offset);
			if (m == VM_PAGE_NULL || m->wire_count == 0 ||
			    m->absent)
			    panic("vm_map_copyout: wiring 0x%x", m);

			m->busy = TRUE;
			vm_object_unlock(object);

			PMAP_ENTER(dst_map->pmap, va, m,
				   entry->protection, TRUE);

			vm_object_lock(object);
			PAGE_WAKEUP_DONE(m);
			/* the page is wired, so we don't have to activate */
			vm_object_paging_end(object);
			vm_object_unlock(object);

			offset += PAGE_SIZE;
			va += PAGE_SIZE;
		    }
		}


	}

	/*
	 *	Correct the page alignment for the result
	 */

	*dst_addr = start + (copy->offset - vm_copy_start);

	/*
	 *	Update the hints and the map size
	 */

	if (dst_map->first_free == last)
		dst_map->first_free = vm_map_copy_last_entry(copy);
	SAVE_HINT(dst_map, vm_map_copy_last_entry(copy));

	dst_map->size += size;

	/*
	 *	Link in the copy
	 */

	vm_map_copy_insert(dst_map, last, copy);

	vm_map_unlock(dst_map);

	/*
	 * XXX	If wiring_required, call vm_map_pageable
	 */

	return(KERN_SUCCESS);
}

/*
 *
 *	vm_map_copyout_page_list:
 *
 *	Version of vm_map_copyout() for page list vm map copies.
 *
 */
kern_return_t vm_map_copyout_page_list(dst_map, dst_addr, copy)
	vm_map_t	dst_map;
	vm_offset_t	*dst_addr;	/* OUT */
	vm_map_copy_t	copy;
{
	vm_size_t	size;
	vm_offset_t	start;
	vm_offset_t	end;
	vm_offset_t	offset;
	vm_map_entry_t	last;
	vm_object_t	object;
	vm_page_t	*page_list, m;
	vm_map_entry_t	entry;
	vm_offset_t	old_last_offset;
	boolean_t	cont_invoked, needs_wakeup = FALSE;
	kern_return_t	result = KERN_SUCCESS;
	vm_map_copy_t	orig_copy;
	vm_offset_t	dst_offset;
	boolean_t	must_wire;

	/*
	 *	Make sure the pages are stolen, because we are
	 *	going to put them in a new object.  Assume that
	 *	all pages are identical to first in this regard.
	 */

	page_list = &copy->cpy_page_list[0];
	if ((*page_list)->tabled)
		vm_map_copy_steal_pages(copy);

	/*
	 *	Find space for the data
	 */

	size =	round_page(copy->offset + copy->size) -
		trunc_page(copy->offset);
StartAgain:
	vm_map_lock(dst_map);
	must_wire = dst_map->wiring_required;

	last = dst_map->first_free;
	if (last == vm_map_to_entry(dst_map)) {
		start = vm_map_min(dst_map);
	} else {
		start = last->vme_end;
	}

	while (TRUE) {
		vm_map_entry_t next = last->vme_next;
		end = start + size;

		if ((end > dst_map->max_offset) || (end < start)) {
			if (dst_map->wait_for_space) {
				if (size <= (dst_map->max_offset -
					     dst_map->min_offset)) {
					assert_wait((event_t) dst_map, TRUE);
					vm_map_unlock(dst_map);
					thread_block((void (*)()) 0);
					goto StartAgain;
				}
			}
			vm_map_unlock(dst_map);
			printf_once("no more room for vm_map_copyout_page_list in %p\n", dst_map);
			return(KERN_NO_SPACE);
		}

		if ((next == vm_map_to_entry(dst_map)) ||
		    (next->vme_start >= end)) {
			break;
		}

		last = next;
		start = last->vme_end;
	}

	/*
	 *	See whether we can avoid creating a new entry (and object) by
	 *	extending one of our neighbors.  [So far, we only attempt to
	 *	extend from below.]
	 *
	 *	The code path below here is a bit twisted.  If any of the
	 *	extension checks fails, we branch to create_object.  If
	 *	it all works, we fall out the bottom and goto insert_pages.
	 */
	if (last == vm_map_to_entry(dst_map) ||
	    last->vme_end != start ||
	    last->is_shared != FALSE ||
	    last->is_sub_map != FALSE ||
	    last->inheritance != VM_INHERIT_DEFAULT ||
	    last->protection != VM_PROT_DEFAULT ||
	    last->max_protection != VM_PROT_ALL ||
	    (must_wire ? (last->wired_count != 1 ||
		    last->user_wired_count != 1) :
		(last->wired_count != 0))) {
		    goto create_object;
	}

	/*
	 * If this entry needs an object, make one.
	 */
	if (last->object.vm_object == VM_OBJECT_NULL) {
		object = vm_object_allocate(
			(vm_size_t)(last->vme_end - last->vme_start + size));
		last->object.vm_object = object;
		last->offset = 0;
		vm_object_lock(object);
	}
	else {
	    vm_offset_t	prev_offset = last->offset;
	    vm_size_t	prev_size = start - last->vme_start;
	    vm_size_t	new_size;

	    /*
	     *	This is basically vm_object_coalesce.
	     */

	    object = last->object.vm_object;
	    vm_object_lock(object);

	    /*
	     *	Try to collapse the object first
	     */
	    vm_object_collapse(object);

	    /*
	     *	Can't coalesce if pages not mapped to
	     *	last may be in use anyway:
	     *	. more than one reference
	     *	. paged out
	     *	. shadows another object
	     *	. has a copy elsewhere
	     *	. paging references (pages might be in page-list)
	     */

	    if ((object->ref_count > 1) ||
		object->pager_created ||
		(object->shadow != VM_OBJECT_NULL) ||
		(object->copy != VM_OBJECT_NULL) ||
		(object->paging_in_progress != 0)) {
		    vm_object_unlock(object);
		    goto create_object;
	    }

	    /*
	     *	Extend the object if necessary.  Don't have to call
	     *  vm_object_page_remove because the pages aren't mapped,
	     *	and vm_page_replace will free up any old ones it encounters.
	     */
	    new_size = prev_offset + prev_size + size;
	    if (new_size > object->size)
		object->size = new_size;
        }

	/*
	 *	Coalesced the two objects - can extend
	 *	the previous map entry to include the
	 *	new range.
	 */
	dst_map->size += size;
	last->vme_end = end;

	SAVE_HINT(dst_map, last);

	goto insert_pages;

create_object:

	/*
	 *	Create object
	 */
	object = vm_object_allocate(size);

	/*
	 *	Create entry
	 */

	entry = vm_map_entry_create(dst_map);

	entry->object.vm_object = object;
	entry->offset = 0;

	entry->is_shared = FALSE;
	entry->is_sub_map = FALSE;
	entry->needs_copy = FALSE;

	if (must_wire) {
		entry->wired_count = 1;
		entry->user_wired_count = 1;
	} else {
		entry->wired_count = 0;
		entry->user_wired_count = 0;
	}

	entry->in_transition = TRUE;
	entry->needs_wakeup = FALSE;

	entry->vme_start = start;
	entry->vme_end = start + size;

	entry->inheritance = VM_INHERIT_DEFAULT;
	entry->protection = VM_PROT_DEFAULT;
	entry->max_protection = VM_PROT_ALL;
	entry->projected_on = 0;

	vm_object_lock(object);

	/*
	 *	Update the hints and the map size
	 */
	if (dst_map->first_free == last) {
		dst_map->first_free = entry;
	}
	SAVE_HINT(dst_map, entry);
	dst_map->size += size;

	/*
	 *	Link in the entry
	 */
	vm_map_entry_link(dst_map, last, entry);
	last = entry;

	/*
	 *	Transfer pages into new object.
	 *	Scan page list in vm_map_copy.
	 */
insert_pages:
	dst_offset = copy->offset & PAGE_MASK;
	cont_invoked = FALSE;
	orig_copy = copy;
	last->in_transition = TRUE;
	old_last_offset = last->offset
	    + (start - last->vme_start);

	vm_page_lock_queues();

	for (offset = 0; offset < size; offset += PAGE_SIZE) {
		m = *page_list;
		assert(m && !m->tabled);

		/*
		 *	Must clear busy bit in page before inserting it.
		 *	Ok to skip wakeup logic because nobody else
		 *	can possibly know about this page.
		 *	The page is dirty in its new object.
		 */

		assert(!m->wanted);

		m->busy = FALSE;
		m->dirty = TRUE;
		vm_page_replace(m, object, old_last_offset + offset);
		if (must_wire) {
			vm_page_wire(m);
			PMAP_ENTER(dst_map->pmap,
				   last->vme_start + m->offset - last->offset,
				   m, last->protection, TRUE);
		} else {
			vm_page_activate(m);
		}

		*page_list++ = VM_PAGE_NULL;
		if (--(copy->cpy_npages) == 0 &&
		    vm_map_copy_has_cont(copy)) {
			vm_map_copy_t	new_copy;

			/*
			 *	Ok to unlock map because entry is
			 *	marked in_transition.
			 */
			cont_invoked = TRUE;
			vm_page_unlock_queues();
			vm_object_unlock(object);
			vm_map_unlock(dst_map);
			vm_map_copy_invoke_cont(copy, &new_copy, &result);

			if (result == KERN_SUCCESS) {

				/*
				 *	If we got back a copy with real pages,
				 *	steal them now.  Either all of the
				 *	pages in the list are tabled or none
				 *	of them are; mixtures are not possible.
				 *
				 *	Save original copy for consume on
				 *	success logic at end of routine.
				 */
				if (copy != orig_copy)
					vm_map_copy_discard(copy);

				if ((copy = new_copy) != VM_MAP_COPY_NULL) {
					page_list = &copy->cpy_page_list[0];
					if ((*page_list)->tabled)
				    		vm_map_copy_steal_pages(copy);
				}
			}
			else {
				/*
				 *	Continuation failed.
				 */
				vm_map_lock(dst_map);
				goto error;
			}

			vm_map_lock(dst_map);
			vm_object_lock(object);
			vm_page_lock_queues();
		}
	}

	vm_page_unlock_queues();
	vm_object_unlock(object);

	*dst_addr = start + dst_offset;

	/*
	 *	Clear the in transition bits.  This is easy if we
	 *	didn't have a continuation.
	 */
error:
	if (!cont_invoked) {
		/*
		 *	We didn't unlock the map, so nobody could
		 *	be waiting.
		 */
		last->in_transition = FALSE;
		assert(!last->needs_wakeup);
		needs_wakeup = FALSE;
	}
	else {
		if (!vm_map_lookup_entry(dst_map, start, &entry))
			panic("vm_map_copyout_page_list: missing entry");

                /*
                 * Clear transition bit for all constituent entries that
                 * were in the original entry.  Also check for waiters.
                 */
                while((entry != vm_map_to_entry(dst_map)) &&
                      (entry->vme_start < end)) {
                        assert(entry->in_transition);
                        entry->in_transition = FALSE;
                        if(entry->needs_wakeup) {
                                entry->needs_wakeup = FALSE;
                                needs_wakeup = TRUE;
                        }
                        entry = entry->vme_next;
                }
	}

	if (result != KERN_SUCCESS)
		vm_map_delete(dst_map, start, end);

	vm_map_unlock(dst_map);

	if (needs_wakeup)
		vm_map_entry_wakeup(dst_map);

	/*
	 *	Consume on success logic.
	 */
	if (copy != orig_copy) {
		kmem_cache_free(&vm_map_copy_cache, (vm_offset_t) copy);
	}
	if (result == KERN_SUCCESS) {
		kmem_cache_free(&vm_map_copy_cache, (vm_offset_t) orig_copy);
	}

	return(result);
}

/*
 *	Routine:	vm_map_copyin
 *
 *	Description:
 *		Copy the specified region (src_addr, len) from the
 *		source address space (src_map), possibly removing
 *		the region from the source address space (src_destroy).
 *
 *	Returns:
 *		A vm_map_copy_t object (copy_result), suitable for
 *		insertion into another address space (using vm_map_copyout),
 *		copying over another address space region (using
 *		vm_map_copy_overwrite).  If the copy is unused, it
 *		should be destroyed (using vm_map_copy_discard).
 *
 *	In/out conditions:
 *		The source map should not be locked on entry.
 */
kern_return_t vm_map_copyin(src_map, src_addr, len, src_destroy, copy_result)
	vm_map_t	src_map;
	vm_offset_t	src_addr;
	vm_size_t	len;
	boolean_t	src_destroy;
	vm_map_copy_t	*copy_result;	/* OUT */
{
	vm_map_entry_t	tmp_entry;	/* Result of last map lookup --
					 * in multi-level lookup, this
					 * entry contains the actual
					 * vm_object/offset.
					 */

	vm_offset_t	src_start;	/* Start of current entry --
					 * where copy is taking place now
					 */
	vm_offset_t	src_end;	/* End of entire region to be
					 * copied */

	vm_map_copy_t	copy;		/* Resulting copy */

	/*
	 *	Check for copies of zero bytes.
	 */

	if (len == 0) {
		*copy_result = VM_MAP_COPY_NULL;
		return(KERN_SUCCESS);
	}

	/*
	 *	Compute start and end of region
	 */

	src_start = trunc_page(src_addr);
	src_end = round_page(src_addr + len);

	/*
	 *	Check that the end address doesn't overflow
	 */

	if (src_end <= src_start)
		if ((src_end < src_start) || (src_start != 0))
			return(KERN_INVALID_ADDRESS);

	/*
	 *	Allocate a header element for the list.
	 *
	 *	Use the start and end in the header to
	 *	remember the endpoints prior to rounding.
	 */

	copy = (vm_map_copy_t) kmem_cache_alloc(&vm_map_copy_cache);
	vm_map_copy_first_entry(copy) =
	 vm_map_copy_last_entry(copy) = vm_map_copy_to_entry(copy);
	copy->type = VM_MAP_COPY_ENTRY_LIST;
	copy->cpy_hdr.nentries = 0;
	copy->cpy_hdr.entries_pageable = TRUE;
	rbtree_init(&copy->cpy_hdr.tree);

	copy->offset = src_addr;
	copy->size = len;

#define	RETURN(x)						\
	MACRO_BEGIN						\
	vm_map_unlock(src_map);					\
	vm_map_copy_discard(copy);				\
	MACRO_RETURN(x);					\
	MACRO_END

	/*
	 *	Find the beginning of the region.
	 */

 	vm_map_lock(src_map);

	if (!vm_map_lookup_entry(src_map, src_start, &tmp_entry))
		RETURN(KERN_INVALID_ADDRESS);
	vm_map_clip_start(src_map, tmp_entry, src_start);

	/*
	 *	Go through entries until we get to the end.
	 */

	while (TRUE) {
		vm_map_entry_t	src_entry = tmp_entry;	/* Top-level entry */
		vm_size_t	src_size;		/* Size of source
							 * map entry (in both
							 * maps)
							 */

		vm_object_t	src_object;		/* Object to copy */
		vm_offset_t	src_offset;

		boolean_t	src_needs_copy;		/* Should source map
							 * be made read-only
							 * for copy-on-write?
							 */

		vm_map_entry_t	new_entry;		/* Map entry for copy */
		boolean_t	new_entry_needs_copy;	/* Will new entry be COW? */

		boolean_t	was_wired;		/* Was source wired? */
		vm_map_version_t version;		/* Version before locks
							 * dropped to make copy
							 */

		/*
		 *	Verify that the region can be read.
		 */

		if (! (src_entry->protection & VM_PROT_READ))
			RETURN(KERN_PROTECTION_FAILURE);

		/*
		 *	Clip against the endpoints of the entire region.
		 */

		vm_map_clip_end(src_map, src_entry, src_end);

		src_size = src_entry->vme_end - src_start;
		src_object = src_entry->object.vm_object;
		src_offset = src_entry->offset;
		was_wired = (src_entry->wired_count != 0);

		/*
		 *	Create a new address map entry to
		 *	hold the result.  Fill in the fields from
		 *	the appropriate source entries.
		 */

		new_entry = vm_map_copy_entry_create(copy);
		vm_map_entry_copy(new_entry, src_entry);

		/*
		 *	Attempt non-blocking copy-on-write optimizations.
		 */

		if (src_destroy &&
		    (src_object == VM_OBJECT_NULL ||
		     (src_object->temporary && !src_object->use_shared_copy)))
		{
		    /*
		     * If we are destroying the source, and the object
		     * is temporary, and not shared writable,
		     * we can move the object reference
		     * from the source to the copy.  The copy is
		     * copy-on-write only if the source is.
		     * We make another reference to the object, because
		     * destroying the source entry will deallocate it.
		     */
		    vm_object_reference(src_object);

		    /*
		     * Copy is always unwired.  vm_map_copy_entry
		     * set its wired count to zero.
		     */

		    goto CopySuccessful;
		}

		if (!was_wired &&
		    vm_object_copy_temporary(
				&new_entry->object.vm_object,
				&new_entry->offset,
				&src_needs_copy,
				&new_entry_needs_copy)) {

			new_entry->needs_copy = new_entry_needs_copy;

			/*
			 *	Handle copy-on-write obligations
			 */

			if (src_needs_copy && !tmp_entry->needs_copy) {
				vm_object_pmap_protect(
					src_object,
					src_offset,
					src_size,
			      		(src_entry->is_shared ? PMAP_NULL
						: src_map->pmap),
					src_entry->vme_start,
					src_entry->protection &
						~VM_PROT_WRITE);

				tmp_entry->needs_copy = TRUE;
			}

			/*
			 *	The map has never been unlocked, so it's safe to
			 *	move to the next entry rather than doing another
			 *	lookup.
			 */

			goto CopySuccessful;
		}

		new_entry->needs_copy = FALSE;

		/*
		 *	Take an object reference, so that we may
		 *	release the map lock(s).
		 */

		assert(src_object != VM_OBJECT_NULL);
		vm_object_reference(src_object);

		/*
		 *	Record the timestamp for later verification.
		 *	Unlock the map.
		 */

		version.main_timestamp = src_map->timestamp;
		vm_map_unlock(src_map);

		/*
		 *	Perform the copy
		 */

		if (was_wired) {
			vm_object_lock(src_object);
			(void) vm_object_copy_slowly(
					src_object,
					src_offset,
					src_size,
					FALSE,
					&new_entry->object.vm_object);
			new_entry->offset = 0;
			new_entry->needs_copy = FALSE;
		} else {
			kern_return_t	result;

			result = vm_object_copy_strategically(src_object,
				src_offset,
				src_size,
				&new_entry->object.vm_object,
				&new_entry->offset,
				&new_entry_needs_copy);

			new_entry->needs_copy = new_entry_needs_copy;


			if (result != KERN_SUCCESS) {
				vm_map_copy_entry_dispose(copy, new_entry);

				vm_map_lock(src_map);
				RETURN(result);
			}

		}

		/*
		 *	Throw away the extra reference
		 */

		vm_object_deallocate(src_object);

		/*
		 *	Verify that the map has not substantially
		 *	changed while the copy was being made.
		 */

		vm_map_lock(src_map);	/* Increments timestamp once! */

		if ((version.main_timestamp + 1) == src_map->timestamp)
			goto CopySuccessful;

		/*
		 *	Simple version comparison failed.
		 *
		 *	Retry the lookup and verify that the
		 *	same object/offset are still present.
		 *
		 *	[Note: a memory manager that colludes with
		 *	the calling task can detect that we have
		 *	cheated.  While the map was unlocked, the
		 *	mapping could have been changed and restored.]
		 */

		if (!vm_map_lookup_entry(src_map, src_start, &tmp_entry)) {
			vm_map_copy_entry_dispose(copy, new_entry);
			RETURN(KERN_INVALID_ADDRESS);
		}

		src_entry = tmp_entry;
		vm_map_clip_start(src_map, src_entry, src_start);

		if ((src_entry->protection & VM_PROT_READ) == VM_PROT_NONE)
			goto VerificationFailed;

		if (src_entry->vme_end < new_entry->vme_end)
			src_size = (new_entry->vme_end = src_entry->vme_end) - src_start;

		if ((src_entry->object.vm_object != src_object) ||
		    (src_entry->offset != src_offset) ) {

			/*
			 *	Verification failed.
			 *
			 *	Start over with this top-level entry.
			 */

		 VerificationFailed: ;

			vm_object_deallocate(new_entry->object.vm_object);
			vm_map_copy_entry_dispose(copy, new_entry);
			tmp_entry = src_entry;
			continue;
		}

		/*
		 *	Verification succeeded.
		 */

	 CopySuccessful: ;

		/*
		 *	Link in the new copy entry.
		 */

		vm_map_copy_entry_link(copy, vm_map_copy_last_entry(copy),
				       new_entry);

		/*
		 *	Determine whether the entire region
		 *	has been copied.
		 */
		src_start = new_entry->vme_end;
		if ((src_start >= src_end) && (src_end != 0))
			break;

		/*
		 *	Verify that there are no gaps in the region
		 */

		tmp_entry = src_entry->vme_next;
		if (tmp_entry->vme_start != src_start)
			RETURN(KERN_INVALID_ADDRESS);
	}

	/*
	 * If the source should be destroyed, do it now, since the
	 * copy was successful.
	 */
	if (src_destroy)
	    (void) vm_map_delete(src_map, trunc_page(src_addr), src_end);

	vm_map_unlock(src_map);

	*copy_result = copy;
	return(KERN_SUCCESS);

#undef	RETURN
}

/*
 *	vm_map_copyin_object:
 *
 *	Create a copy object from an object.
 *	Our caller donates an object reference.
 */

kern_return_t vm_map_copyin_object(object, offset, size, copy_result)
	vm_object_t	object;
	vm_offset_t	offset;		/* offset of region in object */
	vm_size_t	size;		/* size of region in object */
	vm_map_copy_t	*copy_result;	/* OUT */
{
	vm_map_copy_t	copy;		/* Resulting copy */

	/*
	 *	We drop the object into a special copy object
	 *	that contains the object directly.  These copy objects
	 *	are distinguished by entries_pageable == FALSE
	 *	and null links.
	 */

	copy = (vm_map_copy_t) kmem_cache_alloc(&vm_map_copy_cache);
	vm_map_copy_first_entry(copy) =
	 vm_map_copy_last_entry(copy) = VM_MAP_ENTRY_NULL;
	copy->type = VM_MAP_COPY_OBJECT;
	copy->cpy_object = object;
	copy->offset = offset;
	copy->size = size;

	*copy_result = copy;
	return(KERN_SUCCESS);
}

/*
 *	vm_map_copyin_page_list_cont:
 *
 *	Continuation routine for vm_map_copyin_page_list.
 *
 *	If vm_map_copyin_page_list can't fit the entire vm range
 *	into a single page list object, it creates a continuation.
 *	When the target of the operation has used the pages in the
 *	initial page list, it invokes the continuation, which calls
 *	this routine.  If an error happens, the continuation is aborted
 *	(abort arg to this routine is TRUE).  To avoid deadlocks, the
 *	pages are discarded from the initial page list before invoking
 *	the continuation.
 *
 *	NOTE: This is not the same sort of continuation used by
 *	the scheduler.
 */

kern_return_t	vm_map_copyin_page_list_cont(cont_args, copy_result)
vm_map_copyin_args_t	cont_args;
vm_map_copy_t		*copy_result;	/* OUT */
{
	kern_return_t	result = 0; /* '=0' to quiet gcc warnings */
	boolean_t	do_abort, src_destroy, src_destroy_only;

	/*
	 *	Check for cases that only require memory destruction.
	 */
	do_abort = (copy_result == (vm_map_copy_t *) 0);
	src_destroy = (cont_args->destroy_len != (vm_size_t) 0);
	src_destroy_only = (cont_args->src_len == (vm_size_t) 0);

	if (do_abort || src_destroy_only) {
		if (src_destroy)
			result = vm_map_remove(cont_args->map,
			    cont_args->destroy_addr,
			    cont_args->destroy_addr + cont_args->destroy_len);
		if (!do_abort)
			*copy_result = VM_MAP_COPY_NULL;
	}
	else {
		result = vm_map_copyin_page_list(cont_args->map,
			cont_args->src_addr, cont_args->src_len, src_destroy,
			cont_args->steal_pages, copy_result, TRUE);

		if (src_destroy && !cont_args->steal_pages &&
			vm_map_copy_has_cont(*copy_result)) {
			    vm_map_copyin_args_t	new_args;
		    	    /*
			     *	Transfer old destroy info.
			     */
			    new_args = (vm_map_copyin_args_t)
			    		(*copy_result)->cpy_cont_args;
		            new_args->destroy_addr = cont_args->destroy_addr;
		            new_args->destroy_len = cont_args->destroy_len;
		}
	}

	vm_map_deallocate(cont_args->map);
	kfree((vm_offset_t)cont_args, sizeof(vm_map_copyin_args_data_t));

	return(result);
}

/*
 *	vm_map_copyin_page_list:
 *
 *	This is a variant of vm_map_copyin that copies in a list of pages.
 *	If steal_pages is TRUE, the pages are only in the returned list.
 *	If steal_pages is FALSE, the pages are busy and still in their
 *	objects.  A continuation may be returned if not all the pages fit:
 *	the recipient of this copy_result must be prepared to deal with it.
 */

kern_return_t vm_map_copyin_page_list(src_map, src_addr, len, src_destroy,
			    steal_pages, copy_result, is_cont)
	vm_map_t	src_map;
	vm_offset_t	src_addr;
	vm_size_t	len;
	boolean_t	src_destroy;
	boolean_t	steal_pages;
	vm_map_copy_t	*copy_result;	/* OUT */
	boolean_t	is_cont;
{
	vm_map_entry_t	src_entry;
	vm_page_t 	m;
	vm_offset_t	src_start;
	vm_offset_t	src_end;
	vm_size_t	src_size;
	vm_object_t	src_object;
	vm_offset_t	src_offset;
	vm_offset_t	src_last_offset;
	vm_map_copy_t	copy;		/* Resulting copy */
	kern_return_t	result = KERN_SUCCESS;
	boolean_t	need_map_lookup;
        vm_map_copyin_args_t	cont_args;

	/*
	 * 	If steal_pages is FALSE, this leaves busy pages in
	 *	the object.  A continuation must be used if src_destroy
	 *	is true in this case (!steal_pages && src_destroy).
	 *
	 * XXX	Still have a more general problem of what happens
	 * XXX	if the same page occurs twice in a list.  Deadlock
	 * XXX	can happen if vm_fault_page was called.  A
	 * XXX	possible solution is to use a continuation if vm_fault_page
	 * XXX	is called and we cross a map entry boundary.
	 */

	/*
	 *	Check for copies of zero bytes.
	 */

	if (len == 0) {
		*copy_result = VM_MAP_COPY_NULL;
		return(KERN_SUCCESS);
	}

	/*
	 *	Compute start and end of region
	 */

	src_start = trunc_page(src_addr);
	src_end = round_page(src_addr + len);

	/*
	 *	Check that the end address doesn't overflow
	 */

	if (src_end <= src_start && (src_end < src_start || src_start != 0)) {
		return KERN_INVALID_ADDRESS;
	}

	/*
	 *	Allocate a header element for the page list.
	 *
	 *	Record original offset and size, as caller may not
	 *      be page-aligned.
	 */

	copy = (vm_map_copy_t) kmem_cache_alloc(&vm_map_copy_cache);
	copy->type = VM_MAP_COPY_PAGE_LIST;
	copy->cpy_npages = 0;
	copy->offset = src_addr;
	copy->size = len;
	copy->cpy_cont = ((kern_return_t (*)()) 0);
	copy->cpy_cont_args = (char *) VM_MAP_COPYIN_ARGS_NULL;

	/*
	 *	Find the beginning of the region.
	 */

do_map_lookup:

 	vm_map_lock(src_map);

	if (!vm_map_lookup_entry(src_map, src_start, &src_entry)) {
		result = KERN_INVALID_ADDRESS;
		goto error;
	}
	need_map_lookup = FALSE;

	/*
	 *	Go through entries until we get to the end.
	 */

	while (TRUE) {

		if (! (src_entry->protection & VM_PROT_READ)) {
			result = KERN_PROTECTION_FAILURE;
			goto error;
		}

		if (src_end > src_entry->vme_end)
			src_size = src_entry->vme_end - src_start;
		else
			src_size = src_end - src_start;

		src_object = src_entry->object.vm_object;
		src_offset = src_entry->offset +
				(src_start - src_entry->vme_start);

		/*
		 *	If src_object is NULL, allocate it now;
		 *	we're going to fault on it shortly.
		 */
		if (src_object == VM_OBJECT_NULL) {
			src_object = vm_object_allocate((vm_size_t)
				src_entry->vme_end -
				src_entry->vme_start);
			src_entry->object.vm_object = src_object;
		}

		/*
		 * Iterate over pages.  Fault in ones that aren't present.
		 */
		src_last_offset = src_offset + src_size;
		for (; (src_offset < src_last_offset && !need_map_lookup);
		       src_offset += PAGE_SIZE, src_start += PAGE_SIZE) {

			if (copy->cpy_npages == VM_MAP_COPY_PAGE_LIST_MAX) {
make_continuation:
			    /*
			     *	At this point we have the max number of
			     *  pages busy for this thread that we're
			     *  willing to allow.  Stop here and record
			     *  arguments for the remainder.  Note:
			     *  this means that this routine isn't atomic,
			     *  but that's the breaks.  Note that only
			     *  the first vm_map_copy_t that comes back
			     *  from this routine has the right offset
			     *  and size; those from continuations are
			     *  page rounded, and short by the amount
			     *	already done.
			     *
			     *	Reset src_end so the src_destroy
			     *	code at the bottom doesn't do
			     *	something stupid.
			     */

			    cont_args = (vm_map_copyin_args_t)
			    	    kalloc(sizeof(vm_map_copyin_args_data_t));
			    cont_args->map = src_map;
			    vm_map_reference(src_map);
			    cont_args->src_addr = src_start;
			    cont_args->src_len = len - (src_start - src_addr);
			    if (src_destroy) {
			    	cont_args->destroy_addr = cont_args->src_addr;
				cont_args->destroy_len = cont_args->src_len;
			    }
			    else {
			    	cont_args->destroy_addr = (vm_offset_t) 0;
				cont_args->destroy_len = (vm_offset_t) 0;
			    }
			    cont_args->steal_pages = steal_pages;

			    copy->cpy_cont_args = (char *) cont_args;
			    copy->cpy_cont = vm_map_copyin_page_list_cont;

			    src_end = src_start;
			    vm_map_clip_end(src_map, src_entry, src_end);
			    break;
			}

			/*
			 *	Try to find the page of data.
			 */
			vm_object_lock(src_object);
			vm_object_paging_begin(src_object);
			if (((m = vm_page_lookup(src_object, src_offset)) !=
			    VM_PAGE_NULL) && !m->busy && !m->fictitious &&
			    !m->absent && !m->error) {

				/*
				 *	This is the page.  Mark it busy
				 *	and keep the paging reference on
				 *	the object whilst we do our thing.
				 */
				m->busy = TRUE;

				/*
				 *	Also write-protect the page, so
				 *	that the map`s owner cannot change
				 *	the data.  The busy bit will prevent
				 *	faults on the page from succeeding
				 *	until the copy is released; after
				 *	that, the page can be re-entered
				 *	as writable, since we didn`t alter
				 *	the map entry.  This scheme is a
				 *	cheap copy-on-write.
				 *
				 *	Don`t forget the protection and
				 *	the page_lock value!
				 *
				 *	If the source is being destroyed
				 *	AND not shared writable, we don`t
				 *	have to protect the page, since
				 *	we will destroy the (only)
				 *	writable mapping later.
				 */
				if (!src_destroy ||
				    src_object->use_shared_copy)
				{
				    pmap_page_protect(m->phys_addr,
						  src_entry->protection
						& ~m->page_lock
						& ~VM_PROT_WRITE);
				}

			}
			else {
				vm_prot_t result_prot;
				vm_page_t top_page;
				kern_return_t kr;

				/*
				 *	Have to fault the page in; must
				 *	unlock the map to do so.  While
				 *	the map is unlocked, anything
				 *	can happen, we must lookup the
				 *	map entry before continuing.
				 */
				vm_map_unlock(src_map);
				need_map_lookup = TRUE;
retry:
				result_prot = VM_PROT_READ;

				kr = vm_fault_page(src_object, src_offset,
						   VM_PROT_READ, FALSE, FALSE,
						   &result_prot, &m, &top_page,
						   FALSE, (void (*)()) 0);
				/*
				 *	Cope with what happened.
				 */
				switch (kr) {
				case VM_FAULT_SUCCESS:
					break;
				case VM_FAULT_INTERRUPTED: /* ??? */
			        case VM_FAULT_RETRY:
					vm_object_lock(src_object);
					vm_object_paging_begin(src_object);
					goto retry;
				case VM_FAULT_MEMORY_SHORTAGE:
					VM_PAGE_WAIT((void (*)()) 0);
					vm_object_lock(src_object);
					vm_object_paging_begin(src_object);
					goto retry;
				case VM_FAULT_FICTITIOUS_SHORTAGE:
					vm_page_more_fictitious();
					vm_object_lock(src_object);
					vm_object_paging_begin(src_object);
					goto retry;
				case VM_FAULT_MEMORY_ERROR:
					/*
					 *	Something broke.  If this
					 *	is a continuation, return
					 *	a partial result if possible,
					 *	else fail the whole thing.
					 *	In the continuation case, the
					 *	next continuation call will
					 *	get this error if it persists.
					 */
					vm_map_lock(src_map);
					if (is_cont &&
					    copy->cpy_npages != 0)
						goto make_continuation;

					result = KERN_MEMORY_ERROR;
					goto error;
				}

				if (top_page != VM_PAGE_NULL) {
					vm_object_lock(src_object);
					VM_PAGE_FREE(top_page);
					vm_object_paging_end(src_object);
					vm_object_unlock(src_object);
				 }

				 /*
				  *	We do not need to write-protect
				  *	the page, since it cannot have
				  *	been in the pmap (and we did not
				  *	enter it above).  The busy bit
				  *	will protect the page from being
				  *	entered as writable until it is
				  *	unlocked.
				  */

			}

			/*
			 *	The page is busy, its object is locked, and
			 *	we have a paging reference on it.  Either
			 *	the map is locked, or need_map_lookup is
			 *	TRUE.
			 *
			 *	Put the page in the page list.
			 */
			copy->cpy_page_list[copy->cpy_npages++] = m;
			vm_object_unlock(m->object);
		}

		/*
		 *	DETERMINE whether the entire region
		 *	has been copied.
		 */
		if (src_start >= src_end && src_end != 0) {
			if (need_map_lookup)
				vm_map_lock(src_map);
			break;
		}

		/*
		 *	If need_map_lookup is TRUE, have to start over with
		 *	another map lookup.  Note that we dropped the map
		 *	lock (to call vm_fault_page) above only in this case.
		 */
		if (need_map_lookup)
			goto do_map_lookup;

		/*
		 *	Verify that there are no gaps in the region
		 */

		src_start = src_entry->vme_end;
		src_entry = src_entry->vme_next;
		if (src_entry->vme_start != src_start) {
			result = KERN_INVALID_ADDRESS;
			goto error;
		}
	}

	/*
	 *	If steal_pages is true, make sure all
	 *	pages in the copy are not in any object
	 *	We try to remove them from the original
	 *	object, but we may have to copy them.
	 *
	 *	At this point every page in the list is busy
	 *	and holds a paging reference to its object.
	 *	When we're done stealing, every page is busy,
	 *	and in no object (m->tabled == FALSE).
	 */
	src_start = trunc_page(src_addr);
	if (steal_pages) {
		int 		i;
		vm_offset_t	unwire_end;

		unwire_end = src_start;
		for (i = 0; i < copy->cpy_npages; i++) {

			/*
			 *	Remove the page from its object if it
			 *	can be stolen.  It can be stolen if:
 			 *
			 *	(1) The source is being destroyed,
			 *	      the object is temporary, and
			 *	      not shared.
			 *	(2) The page is not precious.
			 *
			 *	The not shared check consists of two
			 *	parts:  (a) there are no objects that
			 *	shadow this object.  (b) it is not the
			 *	object in any shared map entries (i.e.,
			 *	use_shared_copy is not set).
			 *
			 *	The first check (a) means that we can't
			 *	steal pages from objects that are not
			 *	at the top of their shadow chains.  This
			 *	should not be a frequent occurrence.
			 *
			 *	Stealing wired pages requires telling the
			 *	pmap module to let go of them.
			 *
			 *	NOTE: stealing clean pages from objects
			 *  	whose mappings survive requires a call to
			 *	the pmap module.  Maybe later.
 			 */
			m = copy->cpy_page_list[i];
			src_object = m->object;
			vm_object_lock(src_object);

			if (src_destroy &&
			    src_object->temporary &&
			    (!src_object->shadowed) &&
			    (!src_object->use_shared_copy) &&
			    !m->precious) {
				vm_offset_t	page_vaddr;

				page_vaddr = src_start + (i * PAGE_SIZE);
				if (m->wire_count > 0) {

				    assert(m->wire_count == 1);
				    /*
				     *	In order to steal a wired
				     *	page, we have to unwire it
				     *	first.  We do this inline
				     *	here because we have the page.
				     *
				     *	Step 1: Unwire the map entry.
				     *		Also tell the pmap module
				     *		that this piece of the
				     *		pmap is pageable.
				     */
				    vm_object_unlock(src_object);
				    if (page_vaddr >= unwire_end) {
				        if (!vm_map_lookup_entry(src_map,
				            page_vaddr, &src_entry))
		    panic("vm_map_copyin_page_list: missing wired map entry");

				        vm_map_clip_start(src_map, src_entry,
						page_vaddr);
				    	vm_map_clip_end(src_map, src_entry,
						src_start + src_size);

					assert(src_entry->wired_count > 0);
				        src_entry->wired_count = 0;
				        src_entry->user_wired_count = 0;
					unwire_end = src_entry->vme_end;
				        pmap_pageable(vm_map_pmap(src_map),
					    page_vaddr, unwire_end, TRUE);
				    }

				    /*
				     *	Step 2: Unwire the page.
				     *	pmap_remove handles this for us.
				     */
				    vm_object_lock(src_object);
				}

				/*
				 *	Don't need to remove the mapping;
				 *	vm_map_delete will handle it.
				 *
				 *	Steal the page.  Setting the wire count
				 *	to zero is vm_page_unwire without
				 *	activating the page.
  				 */
				vm_page_lock_queues();
	 			vm_page_remove(m);
				if (m->wire_count > 0) {
				    m->wire_count = 0;
				    vm_page_wire_count--;
				} else {
				    VM_PAGE_QUEUES_REMOVE(m);
				}
				vm_page_unlock_queues();
			}
			else {
			        /*
				 *	Have to copy this page.  Have to
				 *	unlock the map while copying,
				 *	hence no further page stealing.
				 *	Hence just copy all the pages.
				 *	Unlock the map while copying;
				 *	This means no further page stealing.
				 */
				vm_object_unlock(src_object);
				vm_map_unlock(src_map);

				vm_map_copy_steal_pages(copy);

				vm_map_lock(src_map);
				break;
		        }

			vm_object_paging_end(src_object);
			vm_object_unlock(src_object);
	        }

		/*
		 * If the source should be destroyed, do it now, since the
		 * copy was successful.
		 */

		if (src_destroy) {
		    (void) vm_map_delete(src_map, src_start, src_end);
		}
	}
	else {
		/*
		 *	!steal_pages leaves busy pages in the map.
		 *	This will cause src_destroy to hang.  Use
		 *	a continuation to prevent this.
		 */
	        if (src_destroy && !vm_map_copy_has_cont(copy)) {
			cont_args = (vm_map_copyin_args_t)
				kalloc(sizeof(vm_map_copyin_args_data_t));
			vm_map_reference(src_map);
			cont_args->map = src_map;
			cont_args->src_addr = (vm_offset_t) 0;
			cont_args->src_len = (vm_size_t) 0;
			cont_args->destroy_addr = src_start;
			cont_args->destroy_len = src_end - src_start;
			cont_args->steal_pages = FALSE;

			copy->cpy_cont_args = (char *) cont_args;
			copy->cpy_cont = vm_map_copyin_page_list_cont;
		}

	}

	vm_map_unlock(src_map);

	*copy_result = copy;
	return(result);

error:
	vm_map_unlock(src_map);
	vm_map_copy_discard(copy);
	return(result);
}

/*
 *	vm_map_fork:
 *
 *	Create and return a new map based on the old
 *	map, according to the inheritance values on the
 *	regions in that map.
 *
 *	The source map must not be locked.
 */
vm_map_t vm_map_fork(old_map)
	vm_map_t	old_map;
{
	vm_map_t	new_map;
	vm_map_entry_t	old_entry;
	vm_map_entry_t	new_entry;
	pmap_t		new_pmap = pmap_create((vm_size_t) 0);
	vm_size_t	new_size = 0;
	vm_size_t	entry_size;
	vm_object_t	object;

	vm_map_lock(old_map);

	new_map = vm_map_create(new_pmap,
			old_map->min_offset,
			old_map->max_offset,
			old_map->hdr.entries_pageable);

	for (
	    old_entry = vm_map_first_entry(old_map);
	    old_entry != vm_map_to_entry(old_map);
	    ) {
		if (old_entry->is_sub_map)
			panic("vm_map_fork: encountered a submap");

		entry_size = (old_entry->vme_end - old_entry->vme_start);

		switch (old_entry->inheritance) {
		case VM_INHERIT_NONE:
			break;

		case VM_INHERIT_SHARE:
		        /*
			 *	New sharing code.  New map entry
			 *	references original object.  Temporary
			 *	objects use asynchronous copy algorithm for
			 *	future copies.  First make sure we have
			 *	the right object.  If we need a shadow,
			 *	or someone else already has one, then
			 *	make a new shadow and share it.
			 */

			object = old_entry->object.vm_object;
			if (object == VM_OBJECT_NULL) {
				object = vm_object_allocate(
					    (vm_size_t)(old_entry->vme_end -
							old_entry->vme_start));
				old_entry->offset = 0;
				old_entry->object.vm_object = object;
				assert(!old_entry->needs_copy);
			}
			else if (old_entry->needs_copy || object->shadowed ||
			    (object->temporary && !old_entry->is_shared &&
			     object->size > (vm_size_t)(old_entry->vme_end -
						old_entry->vme_start))) {

			    assert(object->temporary);
			    assert(!(object->shadowed && old_entry->is_shared));
			    vm_object_shadow(
			        &old_entry->object.vm_object,
			        &old_entry->offset,
			        (vm_size_t) (old_entry->vme_end -
					     old_entry->vme_start));

			    /*
			     *	If we're making a shadow for other than
			     *	copy on write reasons, then we have
			     *	to remove write permission.
			     */

			    if (!old_entry->needs_copy &&
				(old_entry->protection & VM_PROT_WRITE)) {
			    	pmap_protect(vm_map_pmap(old_map),
					     old_entry->vme_start,
					     old_entry->vme_end,
					     old_entry->protection &
					     	~VM_PROT_WRITE);
			    }
			    old_entry->needs_copy = FALSE;
			    object = old_entry->object.vm_object;
			}

			/*
			 *	Set use_shared_copy to indicate that
			 *	object must use shared (delayed) copy-on
			 *	write.  This is ignored for permanent objects.
			 *	Bump the reference count for the new entry
			 */

			vm_object_lock(object);
			object->use_shared_copy = TRUE;
			object->ref_count++;
			vm_object_unlock(object);

			new_entry = vm_map_entry_create(new_map);

			if (old_entry->projected_on != 0) {
			  /*
			   *   If entry is projected buffer, clone the
                           *   entry exactly.
                           */

			  vm_map_entry_copy_full(new_entry, old_entry);

			} else {
			  /*
			   *	Clone the entry, using object ref from above.
			   *	Mark both entries as shared.
			   */

			  vm_map_entry_copy(new_entry, old_entry);
			  old_entry->is_shared = TRUE;
			  new_entry->is_shared = TRUE;
			}

			/*
			 *	Insert the entry into the new map -- we
			 *	know we're inserting at the end of the new
			 *	map.
			 */

			vm_map_entry_link(
				new_map,
				vm_map_last_entry(new_map),
				new_entry);

			/*
			 *	Update the physical map
			 */

			pmap_copy(new_map->pmap, old_map->pmap,
				new_entry->vme_start,
				entry_size,
				old_entry->vme_start);

			new_size += entry_size;
			break;

		case VM_INHERIT_COPY:
			if (old_entry->wired_count == 0) {
				boolean_t	src_needs_copy;
				boolean_t	new_entry_needs_copy;

				new_entry = vm_map_entry_create(new_map);
				vm_map_entry_copy(new_entry, old_entry);

				if (vm_object_copy_temporary(
					&new_entry->object.vm_object,
					&new_entry->offset,
					&src_needs_copy,
					&new_entry_needs_copy)) {

					/*
					 *	Handle copy-on-write obligations
					 */

					if (src_needs_copy && !old_entry->needs_copy) {
						vm_object_pmap_protect(
							old_entry->object.vm_object,
							old_entry->offset,
							entry_size,
							(old_entry->is_shared ?
								PMAP_NULL :
								old_map->pmap),
							old_entry->vme_start,
							old_entry->protection &
							    ~VM_PROT_WRITE);

						old_entry->needs_copy = TRUE;
					}

					new_entry->needs_copy = new_entry_needs_copy;

					/*
					 *	Insert the entry at the end
					 *	of the map.
					 */

					vm_map_entry_link(new_map,
						vm_map_last_entry(new_map),
						new_entry);


					new_size += entry_size;
					break;
				}

				vm_map_entry_dispose(new_map, new_entry);
			}

			/* INNER BLOCK (copy cannot be optimized) */ {

			vm_offset_t	start = old_entry->vme_start;
			vm_map_copy_t	copy;
			vm_map_entry_t	last = vm_map_last_entry(new_map);

			vm_map_unlock(old_map);
			if (vm_map_copyin(old_map,
					start,
					entry_size,
					FALSE,
					&copy)
			    != KERN_SUCCESS) {
			    	vm_map_lock(old_map);
				if (!vm_map_lookup_entry(old_map, start, &last))
					last = last->vme_next;
				old_entry = last;
				/*
				 *	For some error returns, want to
				 *	skip to the next element.
				 */

				continue;
			}

			/*
			 *	Insert the copy into the new map
			 */

			vm_map_copy_insert(new_map, last, copy);
			new_size += entry_size;

			/*
			 *	Pick up the traversal at the end of
			 *	the copied region.
			 */

			vm_map_lock(old_map);
			start += entry_size;
			if (!vm_map_lookup_entry(old_map, start, &last))
				last = last->vme_next;
			 else
				vm_map_clip_start(old_map, last, start);
			old_entry = last;

			continue;
			/* INNER BLOCK (copy cannot be optimized) */ }
		}
		old_entry = old_entry->vme_next;
	}

	new_map->size = new_size;
	vm_map_unlock(old_map);

	return(new_map);
}

/*
 *	vm_map_lookup:
 *
 *	Finds the VM object, offset, and
 *	protection for a given virtual address in the
 *	specified map, assuming a page fault of the
 *	type specified.
 *
 *	Returns the (object, offset, protection) for
 *	this address, whether it is wired down, and whether
 *	this map has the only reference to the data in question.
 *	In order to later verify this lookup, a "version"
 *	is returned.
 *
 *	The map should not be locked; it will not be
 *	locked on exit.  In order to guarantee the
 *	existence of the returned object, it is returned
 *	locked.
 *
 *	If a lookup is requested with "write protection"
 *	specified, the map may be changed to perform virtual
 *	copying operations, although the data referenced will
 *	remain the same.
 */
kern_return_t vm_map_lookup(var_map, vaddr, fault_type, out_version,
				object, offset, out_prot, wired)
	vm_map_t		*var_map;	/* IN/OUT */
	vm_offset_t		vaddr;
	vm_prot_t		fault_type;

	vm_map_version_t	*out_version;	/* OUT */
	vm_object_t		*object;	/* OUT */
	vm_offset_t		*offset;	/* OUT */
	vm_prot_t		*out_prot;	/* OUT */
	boolean_t		*wired;		/* OUT */
{
	vm_map_entry_t		entry;
	vm_map_t		map = *var_map;
	vm_prot_t		prot;

	RetryLookup: ;

	/*
	 *	Lookup the faulting address.
	 */

	vm_map_lock_read(map);

#define	RETURN(why) \
		{ \
		vm_map_unlock_read(map); \
		return(why); \
		}

	/*
	 *	If the map has an interesting hint, try it before calling
	 *	full blown lookup routine.
	 */

	simple_lock(&map->hint_lock);
	entry = map->hint;
	simple_unlock(&map->hint_lock);

	if ((entry == vm_map_to_entry(map)) ||
	    (vaddr < entry->vme_start) || (vaddr >= entry->vme_end)) {
		vm_map_entry_t	tmp_entry;

		/*
		 *	Entry was either not a valid hint, or the vaddr
		 *	was not contained in the entry, so do a full lookup.
		 */
		if (!vm_map_lookup_entry(map, vaddr, &tmp_entry))
			RETURN(KERN_INVALID_ADDRESS);

		entry = tmp_entry;
	}

	/*
	 *	Handle submaps.
	 */

	if (entry->is_sub_map) {
		vm_map_t	old_map = map;

		*var_map = map = entry->object.sub_map;
		vm_map_unlock_read(old_map);
		goto RetryLookup;
	}

	/*
	 *	Check whether this task is allowed to have
	 *	this page.
	 */

	prot = entry->protection;

	if ((fault_type & (prot)) != fault_type) {
		if ((prot & VM_PROT_NOTIFY) && (fault_type & VM_PROT_WRITE)) {
			RETURN(KERN_WRITE_PROTECTION_FAILURE);
		} else {
			RETURN(KERN_PROTECTION_FAILURE);
		}
	}

	/*
	 *	If this page is not pageable, we have to get
	 *	it for all possible accesses.
	 */

	if ((*wired = (entry->wired_count != 0)))
		prot = fault_type = entry->protection;

	/*
	 *	If the entry was copy-on-write, we either ...
	 */

	if (entry->needs_copy) {
	    	/*
		 *	If we want to write the page, we may as well
		 *	handle that now since we've got the map locked.
		 *
		 *	If we don't need to write the page, we just
		 *	demote the permissions allowed.
		 */

		if (fault_type & VM_PROT_WRITE) {
			/*
			 *	Make a new object, and place it in the
			 *	object chain.  Note that no new references
			 *	have appeared -- one just moved from the
			 *	map to the new object.
			 */

			if (vm_map_lock_read_to_write(map)) {
				goto RetryLookup;
			}
			map->timestamp++;

			vm_object_shadow(
			    &entry->object.vm_object,
			    &entry->offset,
			    (vm_size_t) (entry->vme_end - entry->vme_start));

			entry->needs_copy = FALSE;

			vm_map_lock_write_to_read(map);
		}
		else {
			/*
			 *	We're attempting to read a copy-on-write
			 *	page -- don't allow writes.
			 */

			prot &= (~VM_PROT_WRITE);
		}
	}

	/*
	 *	Create an object if necessary.
	 */
	if (entry->object.vm_object == VM_OBJECT_NULL) {

		if (vm_map_lock_read_to_write(map)) {
			goto RetryLookup;
		}

		entry->object.vm_object = vm_object_allocate(
				(vm_size_t)(entry->vme_end - entry->vme_start));
		entry->offset = 0;
		vm_map_lock_write_to_read(map);
	}

	/*
	 *	Return the object/offset from this entry.  If the entry
	 *	was copy-on-write or empty, it has been fixed up.  Also
	 *	return the protection.
	 */

        *offset = (vaddr - entry->vme_start) + entry->offset;
        *object = entry->object.vm_object;
	*out_prot = prot;

	/*
	 *	Lock the object to prevent it from disappearing
	 */

	vm_object_lock(*object);

	/*
	 *	Save the version number and unlock the map.
	 */

	out_version->main_timestamp = map->timestamp;

	RETURN(KERN_SUCCESS);

#undef	RETURN
}

/*
 *	vm_map_verify:
 *
 *	Verifies that the map in question has not changed
 *	since the given version.  If successful, the map
 *	will not change until vm_map_verify_done() is called.
 */
boolean_t	vm_map_verify(map, version)
	vm_map_t	map;
	vm_map_version_t *version;	/* REF */
{
	boolean_t	result;

	vm_map_lock_read(map);
	result = (map->timestamp == version->main_timestamp);

	if (!result)
		vm_map_unlock_read(map);

	return(result);
}

/*
 *	vm_map_verify_done:
 *
 *	Releases locks acquired by a vm_map_verify.
 *
 *	This is now a macro in vm/vm_map.h.  It does a
 *	vm_map_unlock_read on the map.
 */

/*
 *	vm_region:
 *
 *	User call to obtain information about a region in
 *	a task's address map.
 */

kern_return_t	vm_region(map, address, size,
				protection, max_protection,
				inheritance, is_shared,
				object_name, offset_in_object)
	vm_map_t	map;
	vm_offset_t	*address;		/* IN/OUT */
	vm_size_t	*size;			/* OUT */
	vm_prot_t	*protection;		/* OUT */
	vm_prot_t	*max_protection;	/* OUT */
	vm_inherit_t	*inheritance;		/* OUT */
	boolean_t	*is_shared;		/* OUT */
	ipc_port_t	*object_name;		/* OUT */
	vm_offset_t	*offset_in_object;	/* OUT */
{
	vm_map_entry_t	tmp_entry;
	vm_map_entry_t	entry;
	vm_offset_t	tmp_offset;
	vm_offset_t	start;

	if (map == VM_MAP_NULL)
		return(KERN_INVALID_ARGUMENT);

	start = *address;

	vm_map_lock_read(map);
	if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
		if ((entry = tmp_entry->vme_next) == vm_map_to_entry(map)) {
			vm_map_unlock_read(map);
		   	return(KERN_NO_SPACE);
		}
	} else {
		entry = tmp_entry;
	}

	start = entry->vme_start;
	*protection = entry->protection;
	*max_protection = entry->max_protection;
	*inheritance = entry->inheritance;
	*address = start;
	*size = (entry->vme_end - start);

	tmp_offset = entry->offset;


	if (entry->is_sub_map) {
		*is_shared = FALSE;
		*object_name = IP_NULL;
		*offset_in_object = tmp_offset;
	} else {
		*is_shared = entry->is_shared;
		*object_name = vm_object_name(entry->object.vm_object);
		*offset_in_object = tmp_offset;
	}

	vm_map_unlock_read(map);

	return(KERN_SUCCESS);
}

/*
 *	Routine:	vm_map_simplify
 *
 *	Description:
 *		Attempt to simplify the map representation in
 *		the vicinity of the given starting address.
 *	Note:
 *		This routine is intended primarily to keep the
 *		kernel maps more compact -- they generally don't
 *		benefit from the "expand a map entry" technology
 *		at allocation time because the adjacent entry
 *		is often wired down.
 */
void vm_map_simplify(map, start)
	vm_map_t	map;
	vm_offset_t	start;
{
	vm_map_entry_t	this_entry;
	vm_map_entry_t	prev_entry;

	vm_map_lock(map);
	if (
		(vm_map_lookup_entry(map, start, &this_entry)) &&
		((prev_entry = this_entry->vme_prev) != vm_map_to_entry(map)) &&

		(prev_entry->vme_end == start) &&

		(prev_entry->is_shared == FALSE) &&
		(prev_entry->is_sub_map == FALSE) &&

		(this_entry->is_shared == FALSE) &&
		(this_entry->is_sub_map == FALSE) &&

		(prev_entry->inheritance == this_entry->inheritance) &&
		(prev_entry->protection == this_entry->protection) &&
		(prev_entry->max_protection == this_entry->max_protection) &&
		(prev_entry->wired_count == this_entry->wired_count) &&
		(prev_entry->user_wired_count == this_entry->user_wired_count) &&

		(prev_entry->needs_copy == this_entry->needs_copy) &&

		(prev_entry->object.vm_object == this_entry->object.vm_object) &&
		((prev_entry->offset + (prev_entry->vme_end - prev_entry->vme_start))
		     == this_entry->offset) &&
	        (prev_entry->projected_on == 0) &&
	        (this_entry->projected_on == 0)
	) {
		if (map->first_free == this_entry)
			map->first_free = prev_entry;

		SAVE_HINT(map, prev_entry);
		vm_map_entry_unlink(map, this_entry);
		prev_entry->vme_end = this_entry->vme_end;
	 	vm_object_deallocate(this_entry->object.vm_object);
		vm_map_entry_dispose(map, this_entry);
	}
	vm_map_unlock(map);
}


/*
 *	Routine:	vm_map_machine_attribute
 *	Purpose:
 *		Provide machine-specific attributes to mappings,
 *		such as cachability etc. for machines that provide
 *		them.  NUMA architectures and machines with big/strange
 *		caches will use this.
 *	Note:
 *		Responsibilities for locking and checking are handled here,
 *		everything else in the pmap module. If any non-volatile
 *		information must be kept, the pmap module should handle
 *		it itself. [This assumes that attributes do not
 *		need to be inherited, which seems ok to me]
 */
kern_return_t vm_map_machine_attribute(map, address, size, attribute, value)
	vm_map_t	map;
	vm_offset_t	address;
	vm_size_t	size;
	vm_machine_attribute_t	attribute;
	vm_machine_attribute_val_t* value;		/* IN/OUT */
{
	kern_return_t	ret;

	if (address < vm_map_min(map) ||
	    (address + size) > vm_map_max(map))
		return KERN_INVALID_ARGUMENT;

	vm_map_lock(map);

	ret = pmap_attribute(map->pmap, address, size, attribute, value);

	vm_map_unlock(map);

	return ret;
}


#if	MACH_KDB

#define	printf	kdbprintf

/*
 *	vm_map_print:	[ debug ]
 */
void vm_map_print(map)
	vm_map_t	map;
{
	vm_map_entry_t	entry;

	iprintf("Task map 0x%X: pmap=0x%X,",
 		(vm_offset_t) map, (vm_offset_t) (map->pmap));
	 printf("ref=%d,nentries=%d,", map->ref_count, map->hdr.nentries);
	 printf("version=%d\n",	map->timestamp);
	indent += 2;
	for (entry = vm_map_first_entry(map);
	     entry != vm_map_to_entry(map);
	     entry = entry->vme_next) {
		static char *inheritance_name[3] = { "share", "copy", "none"};

		iprintf("map entry 0x%X: ", (vm_offset_t) entry);
		 printf("start=0x%X, end=0x%X, ",
			(vm_offset_t) entry->vme_start, (vm_offset_t) entry->vme_end);
		printf("prot=%X/%X/%s, ",
			entry->protection,
			entry->max_protection,
			inheritance_name[entry->inheritance]);
		if (entry->wired_count != 0) {
			printf("wired(");
			if (entry->user_wired_count != 0)
				printf("u");
			if (entry->wired_count >
			    ((entry->user_wired_count == 0) ? 0 : 1))
				printf("k");
			printf(") ");
		}
		if (entry->in_transition) {
			printf("in transition");
			if (entry->needs_wakeup)
				printf("(wake request)");
			printf(", ");
		}
		if (entry->is_sub_map) {
		 	printf("submap=0x%X, offset=0x%X\n",
				(vm_offset_t) entry->object.sub_map,
				(vm_offset_t) entry->offset);
		} else {
			printf("object=0x%X, offset=0x%X",
				(vm_offset_t) entry->object.vm_object,
				(vm_offset_t) entry->offset);
			if (entry->is_shared)
				printf(", shared");
			if (entry->needs_copy)
				printf(", copy needed");
			printf("\n");

			if ((entry->vme_prev == vm_map_to_entry(map)) ||
			    (entry->vme_prev->object.vm_object != entry->object.vm_object)) {
				indent += 2;
				vm_object_print(entry->object.vm_object);
				indent -= 2;
			}
		}
	}
	indent -= 2;
}

/*
 *	Routine:	vm_map_copy_print
 *	Purpose:
 *		Pretty-print a copy object for ddb.
 */

void vm_map_copy_print(copy)
	vm_map_copy_t copy;
{
	int i, npages;

	printf("copy object 0x%x\n", copy);

	indent += 2;

	iprintf("type=%d", copy->type);
	switch (copy->type) {
		case VM_MAP_COPY_ENTRY_LIST:
		printf("[entry_list]");
		break;

		case VM_MAP_COPY_OBJECT:
		printf("[object]");
		break;

		case VM_MAP_COPY_PAGE_LIST:
		printf("[page_list]");
		break;

		default:
		printf("[bad type]");
		break;
	}
	printf(", offset=0x%x", copy->offset);
	printf(", size=0x%x\n", copy->size);

	switch (copy->type) {
		case VM_MAP_COPY_ENTRY_LIST:
		/* XXX add stuff here */
		break;

		case VM_MAP_COPY_OBJECT:
		iprintf("object=0x%x\n", copy->cpy_object);
		break;

		case VM_MAP_COPY_PAGE_LIST:
		iprintf("npages=%d", copy->cpy_npages);
		printf(", cont=%x", copy->cpy_cont);
		printf(", cont_args=%x\n", copy->cpy_cont_args);
		if (copy->cpy_npages < 0) {
			npages = 0;
		} else if (copy->cpy_npages > VM_MAP_COPY_PAGE_LIST_MAX) {
			npages = VM_MAP_COPY_PAGE_LIST_MAX;
		} else {
			npages = copy->cpy_npages;
		}
		iprintf("copy->cpy_page_list[0..%d] = {", npages);
		for (i = 0; i < npages - 1; i++) {
			printf("0x%x, ", copy->cpy_page_list[i]);
		}
		if (npages > 0) {
			printf("0x%x", copy->cpy_page_list[npages - 1]);
		}
		printf("}\n");
		break;
	}

	indent -= 2;
}
#endif	/* MACH_KDB */