50:
756:—they have a single address space for all user-mode code. (The kernel-mode code may be in the same address space, or it may be in a second address space). Other operating systems have a per-process address space, with a separate address space for each and every user-mode process.
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for all software, and rely on a programming language's semantics to make sure that arbitrary memory cannot be accessed – applications simply cannot acquire any
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232:. With enough privileges, processes can request the kernel to map part of another process's memory space to its own, as is the case for
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193:) refers to all code that runs outside the operating system's kernel. User space usually refers to the various programs and
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space, and, unless explicitly allowed, cannot access the memory of other processes. This is the basis for
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to the objects that they are not allowed to access. This approach has been implemented in
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to provide separate address spaces, or separate regions of a single address space, called
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regions with other processes, although other techniques are also available to allow
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that the operating system uses to interact with the kernel: software that performs
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228:. A separate user mode can also be used to build efficient virtual machines – see
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Another approach taken in experimental operating systems is to have a single
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and hardware protection from malicious or errant software behaviour.
982:
49:
30:"Kernel space" redirects here. For the mathematical definition, see
1476:
688:
233:
177:
and some drivers execute, typically one address space per process.
224:
in today's mainstream operating systems, and a building block for
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1170:
424:
342:
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289:
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Various layers within Linux, also showing separation between the
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Kernel space is strictly reserved for running a privileged
1456:
824:
400:
749:; normal applications in user space run in user mode.
737:. Protection rings, in turn, are implemented using
173:. In contrast, user space is the memory area where
74:. Unsourced material may be challenged and removed.
1511:
158:. Primarily, this separation serves to provide
230:Popek and Goldberg virtualization requirements
998:
940:"uuu/docs/system_introduction/uuu_intro.tex"
1005:
991:
855:. Address space options for 32bit systems.
741:. Typically, kernel space programs run in
520:
259:
134:Learn how and when to remove this message
14:
1512:
754:single address space operating systems
725:The most common way of implementing a
1012:
986:
701:
37:For the user space on Knowledge, see
72:adding citations to reliable sources
43:
771:, Unununium as well as Microsoft's
24:
25:
1536:
961:
823:Older operating systems, such as
720:
1109:Object-oriented operating system
48:
915:"Unununium System Introduction"
831:, do not use this architecture.
590:, etc. (about 380 system calls)
59:needs additional citations for
1119:Supercomputer operating system
979: (archived March 26, 2016)
932:
907:
889:
859:
845:
817:
169:, kernel extensions, and most
13:
1:
968:Linux Kernel Space Definition
944:UUU System Introduction Guide
838:
83:"User space and kernel space"
1094:Just enough operating system
1079:Distributed operating system
236:. Programs can also request
27:Way of using computer memory
7:
1520:Operating system technology
1207:User space and kernel space
901:Kernel.org git repositories
778:
752:Some operating systems are
242:inter-process communication
180:
156:user space and kernel space
10:
1541:
1114:Real-time operating system
733:involves operating system
498:targets embedded systems,
36:
29:
1449:
1386:
1332:
1310:Multilevel feedback queue
1305:Fixed-priority preemptive
1293:
1228:
1219:
1189:
1136:
1127:
1089:Hobbyist operating system
1084:Embedded operating system
1066:
1020:
637:
530:
523:
439:
267:
216:normally runs in its own
1353:General protection fault
1104:Network operating system
1058:User features comparison
810:
492:aims to be lightweight,
1099:Mobile operating system
805:OS-level virtualization
664:Linux Network Scheduler
167:operating system kernel
1202:Loadable kernel module
672:Linux Security Modules
1270:Process control block
1236:Computer multitasking
1074:Disk operating system
633:Networking subsystem
594:System Call Interface
508:, etc. All aim to be
1441:Virtual tape library
1033:Forensic engineering
897:"Admin Guide README"
712:data storage devices
226:privilege separation
207:application software
175:application software
68:improve this article
39:Knowledge:User pages
1450:Supporting concepts
1436:Virtual file system
256:
1373:Segmentation fault
1221:Process management
973:Entering User Mode
775:research project.
638:Other components:
610:Process scheduling
596:(SCI), aims to be
435:C standard library
247:
146:A modern computer
1507:
1506:
1363:Memory protection
1334:Memory management
1328:
1327:
1320:Shortest job next
1215:
1214:
1014:Operating systems
829:Windows 3.1x
800:Memory protection
718:
717:
622:Memory management
592:The Linux kernel
486:aims to be fast,
299:System components
264:User applications
222:memory protection
160:memory protection
144:
143:
136:
118:
16:(Redirected from
1532:
1462:Computer network
1226:
1225:
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1133:
1007:
1000:
993:
984:
983:
955:
954:
952:
951:
936:
930:
929:
927:
926:
917:. Archived from
911:
905:
904:
893:
887:
886:
884:
883:
863:
857:
856:
849:
832:
821:
795:Early user space
735:protection rings
589:
583:
577:
571:
565:
559:
553:
547:
541:
535:
504:was written for
475:... (up to 2000
474:
468:
462:
456:
450:
444:
396:Other libraries:
257:
246:
212:Each user space
148:operating system
139:
132:
128:
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119:
117:
76:
52:
44:
21:
1540:
1539:
1535:
1534:
1533:
1531:
1530:
1529:
1510:
1509:
1508:
1503:
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1406:Defragmentation
1391:
1382:
1368:Protection ring
1337:
1324:
1296:
1289:
1211:
1185:
1123:
1062:
1016:
1011:
977:Wayback Machine
964:
959:
958:
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938:
937:
933:
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922:
913:
912:
908:
895:
894:
890:
881:
879:
877:Eric S. Raymond
865:
864:
860:
853:"Address space"
851:
850:
846:
841:
836:
835:
822:
818:
813:
781:
747:supervisor mode
723:
670:
591:
585:
579:
573:
567:
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549:
543:
537:
531:
480:
470:
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398:
380:
359:
332:
309:
290:Mozilla Firefox
183:
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65:
53:
42:
35:
28:
23:
22:
15:
12:
11:
5:
1538:
1528:
1527:
1525:Device drivers
1522:
1505:
1504:
1502:
1501:
1496:
1495:
1494:
1492:User interface
1489:
1479:
1474:
1469:
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1453:
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1443:
1438:
1433:
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1423:
1418:
1416:File attribute
1413:
1408:
1403:
1397:
1395:
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1383:
1381:
1380:
1378:Virtual memory
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1250:Context switch
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1024:
1022:
1018:
1017:
1010:
1009:
1002:
995:
987:
981:
980:
970:
963:
962:External links
960:
957:
956:
931:
906:
888:
867:"userland, n."
858:
843:
842:
840:
837:
834:
833:
815:
814:
812:
809:
808:
807:
802:
797:
792:
787:
780:
777:
745:, also called
729:separate from
722:
721:Implementation
719:
716:
715:
699:
698:
635:
634:
631:
625:
619:
613:
606:
605:
529:
522:
518:
517:
472:pthread_create
438:
430:
429:
393:
374:
370:SurfaceFlinger
355:Window manager
351:
328:System daemons
324:
301:
295:
294:
266:
261:
218:virtual memory
201:, manipulates
182:
179:
171:device drivers
152:virtual memory
142:
141:
56:
54:
47:
26:
9:
6:
4:
3:
2:
1537:
1526:
1523:
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1500:
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1371:
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1361:
1359:
1358:Memory paging
1356:
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1198:
1197:Device driver
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1169:
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1162:
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1143:
1141:
1139:
1138:Architectures
1135:
1132:
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1120:
1117:
1115:
1112:
1110:
1107:
1105:
1102:
1100:
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994:
989:
988:
985:
978:
974:
971:
969:
966:
965:
945:
941:
935:
921:on 2001-12-15
920:
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873:
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854:
848:
844:
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801:
798:
796:
793:
791:
788:
786:
783:
782:
776:
774:
770:
766:
762:
761:address space
757:
755:
750:
748:
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740:
736:
732:
728:
713:
709:
705:
700:
697:
696:
691:
690:
685:
684:
679:
678:
673:
669:
665:
661:
660:device mapper
657:
653:
649:
645:
641:
636:
632:
629:
628:Virtual files
626:
623:
620:
617:
614:
611:
608:
607:
603:
599:
595:
588:
582:
576:
570:
564:
558:
552:
546:
540:
534:
528:
527:
519:
516:-compatible.
515:
511:
507:
503:
502:
497:
496:
491:
490:
485:
484:
478:
473:
467:
461:
455:
449:
443:
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293:
291:
287:
283:
279:
275:
271:
265:
262:
258:
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251:
245:
243:
239:
238:shared memory
235:
231:
227:
223:
219:
215:
210:
208:
204:
200:
196:
192:
188:
178:
176:
172:
168:
163:
161:
157:
153:
150:usually uses
149:
138:
135:
127:
116:
113:
109:
106:
102:
99:
95:
92:
88:
85: –
84:
80:
79:Find sources:
73:
69:
63:
62:
57:This article
55:
51:
46:
45:
40:
33:
19:
1393:file systems
1285:Time-sharing
1206:
948:. Retrieved
946:. 2001-06-01
943:
934:
923:. Retrieved
919:the original
909:
900:
891:
880:. Retrieved
869:
861:
847:
819:
758:
751:
726:
724:
693:
687:
681:
675:
604:-compatible
526:Linux kernel
524:
521:Kernel mode
499:
493:
487:
481:
433:
399:
395:
389:AMD Catalyst
387:
381:
376:
360:
353:
333:
326:
310:
303:
298:
268:
263:
254:kernel space
253:
249:
211:
199:input/output
190:
186:
184:
164:
155:
145:
130:
124:October 2012
121:
111:
104:
97:
90:
78:
66:Please help
61:verification
58:
18:Kernel space
1411:Device file
1401:Boot loader
1315:Round-robin
1240:Cooperative
1176:Rump kernel
1166:Multikernel
1156:Microkernel
1053:Usage share
872:Jargon File
773:Singularity
743:kernel mode
731:kernel mode
708:main memory
477:subroutines
305:init daemon
274:LibreOffice
203:file system
1514:Categories
1341:protection
1297:algorithms
1295:Scheduling
1244:Preemptive
1190:Components
1161:Monolithic
1028:Comparison
950:2016-08-14
925:2016-08-14
882:2016-08-14
839:References
765:references
702:Hardware (
630:subsystem
624:subsystem
618:subsystem
612:subsystem
260:User mode
187:user space
94:newspapers
32:Null space
1431:Partition
1348:Bus error
1275:Real-time
1255:Interrupt
1181:Unikernel
1146:Exokernel
790:CPU modes
739:CPU modes
727:user mode
668:Netfilter
466:localtime
372:(Android)
234:debuggers
205:objects,
195:libraries
185:The term
1477:Live USB
1339:resource
1229:Concepts
1067:Variants
1048:Timeline
779:See also
714:, etc.)
689:AppArmor
377:Graphics
250:userland
191:userland
181:Overview
1472:Live CD
1426:Journal
1390:access,
1388:Storage
1265:Process
1171:vkernel
1038:History
1021:General
975:at the
677:SELinux
506:Android
425:GNUstep
366:Wayland
335:polkitd
320:systemd
282:Blender
214:process
209:, etc.
108:scholar
1280:Thread
1151:Hybrid
1129:Kernel
683:TOMOYO
539:splice
501:bionic
495:uClibc
460:memcpy
454:malloc
312:OpenRC
286:0 A.D.
110:
103:
96:
89:
81:
1482:Shell
1421:Inode
811:Notes
695:Smack
652:klibc
648:evdev
598:POSIX
581:close
569:write
563:ioctl
510:POSIX
483:glibc
448:execv
442:fopen
427:, ...
391:, ...
347:udevd
316:runit
292:, ...
115:JSTOR
101:books
1043:List
870:The
827:and
785:BIOS
769:JXOS
640:ALSA
587:exit
575:mmap
557:open
551:read
533:stat
489:musl
421:FLTK
417:SFML
383:Mesa
343:sshd
339:smbd
278:GIMP
270:bash
252:and
189:(or
87:news
1499:PXE
1487:CLI
1467:HAL
1457:API
1260:IPC
825:DOS
704:CPU
656:LVM
644:DRI
616:IPC
602:SUS
545:dup
514:SUS
413:SDL
409:EFL
401:GTK
362:X11
349:...
322:...
70:by
1516::
1242:,
942:.
899:.
875:.
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680:,
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405:Qt
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928:.
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479:)
379::
358::
331::
308::
137:)
131:(
126:)
122:(
112:·
105:·
98:·
91:·
64:.
41:.
34:.
20:)
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