5e677e6afdef72b4b55b3a93af33b6189980efc1
[openwrt/staging/wigyori.git] / config / Config-kernel.in
1 # Copyright (C) 2006-2014 OpenWrt.org
2 #
3 # This is free software, licensed under the GNU General Public License v2.
4 # See /LICENSE for more information.
5 #
6
7 config KERNEL_BUILD_USER
8 string "Custom Kernel Build User Name"
9 default "builder" if BUILDBOT
10 default ""
11 help
12 Sets the Kernel build user string, which for example will be returned
13 by 'uname -a' on running systems.
14 If not set, uses system user at build time.
15
16 config KERNEL_BUILD_DOMAIN
17 string "Custom Kernel Build Domain Name"
18 default "buildhost" if BUILDBOT
19 default ""
20 help
21 Sets the Kernel build domain string, which for example will be
22 returned by 'uname -a' on running systems.
23 If not set, uses system hostname at build time.
24
25 config KERNEL_PRINTK
26 bool "Enable support for printk"
27 default y
28
29 config KERNEL_CRASHLOG
30 bool "Crash logging"
31 depends on !(arm || powerpc || sparc || TARGET_uml || i386 || x86_64)
32 default y
33
34 config KERNEL_SWAP
35 bool "Support for paging of anonymous memory (swap)"
36 default y if !SMALL_FLASH
37
38 config KERNEL_DEBUG_FS
39 bool "Compile the kernel with debug filesystem enabled"
40 default y
41 help
42 debugfs is a virtual file system that kernel developers use to put
43 debugging files into. Enable this option to be able to read and
44 write to these files. Many common debugging facilities, such as
45 ftrace, require the existence of debugfs.
46
47 config KERNEL_MIPS_FPU_EMULATOR
48 bool "Compile the kernel with MIPS FPU Emulator"
49 default y if TARGET_pistachio
50 depends on (mips || mipsel || mips64 || mips64el)
51
52 config KERNEL_ARM_PMU
53 bool
54 default n
55 depends on (arm || aarch64)
56
57 config KERNEL_X86_VSYSCALL_EMULATION
58 bool "Enable vsyscall emulation"
59 default n
60 depends on x86_64
61 help
62 This enables emulation of the legacy vsyscall page. Disabling
63 it is roughly equivalent to booting with vsyscall=none, except
64 that it will also disable the helpful warning if a program
65 tries to use a vsyscall. With this option set to N, offending
66 programs will just segfault, citing addresses of the form
67 0xffffffffff600?00.
68
69 This option is required by many programs built before 2013, and
70 care should be used even with newer programs if set to N.
71
72 Disabling this option saves about 7K of kernel size and
73 possibly 4K of additional runtime pagetable memory.
74
75 config KERNEL_PERF_EVENTS
76 bool "Compile the kernel with performance events and counters"
77 default n
78 select KERNEL_ARM_PMU if (arm || aarch64)
79
80 config KERNEL_PROFILING
81 bool "Compile the kernel with profiling enabled"
82 default n
83 select KERNEL_PERF_EVENTS
84 help
85 Enable the extended profiling support mechanisms used by profilers such
86 as OProfile.
87
88 config KERNEL_UBSAN
89 bool "Compile the kernel with undefined behaviour sanity checker"
90 help
91 This option enables undefined behaviour sanity checker
92 Compile-time instrumentation is used to detect various undefined
93 behaviours in runtime. Various types of checks may be enabled
94 via boot parameter ubsan_handle
95 (see: Documentation/dev-tools/ubsan.rst).
96
97 config KERNEL_UBSAN_SANITIZE_ALL
98 bool "Enable instrumentation for the entire kernel"
99 depends on KERNEL_UBSAN
100 default y
101 help
102 This option activates instrumentation for the entire kernel.
103 If you don't enable this option, you have to explicitly specify
104 UBSAN_SANITIZE := y for the files/directories you want to check for UB.
105 Enabling this option will get kernel image size increased
106 significantly.
107
108 config KERNEL_UBSAN_ALIGNMENT
109 bool "Enable checking of pointers alignment"
110 depends on KERNEL_UBSAN
111 help
112 This option enables detection of unaligned memory accesses.
113 Enabling this option on architectures that support unaligned
114 accesses may produce a lot of false positives.
115
116 config KERNEL_UBSAN_NULL
117 bool "Enable checking of null pointers"
118 depends on KERNEL_UBSAN
119 help
120 This option enables detection of memory accesses via a
121 null pointer.
122
123 config KERNEL_KASAN
124 bool "Compile the kernel with KASan: runtime memory debugger"
125 select KERNEL_SLUB_DEBUG
126 depends on (x86_64 || aarch64)
127 help
128 Enables kernel address sanitizer - runtime memory debugger,
129 designed to find out-of-bounds accesses and use-after-free bugs.
130 This is strictly a debugging feature and it requires a gcc version
131 of 4.9.2 or later. Detection of out of bounds accesses to stack or
132 global variables requires gcc 5.0 or later.
133 This feature consumes about 1/8 of available memory and brings about
134 ~x3 performance slowdown.
135 For better error detection enable CONFIG_STACKTRACE.
136 Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
137 (the resulting kernel does not boot).
138
139 config KERNEL_KASAN_EXTRA
140 bool "KAsan: extra checks"
141 depends on KERNEL_KASAN && KERNEL_DEBUG_KERNEL
142 help
143 This enables further checks in the kernel address sanitizer, for now
144 it only includes the address-use-after-scope check that can lead
145 to excessive kernel stack usage, frame size warnings and longer
146 compile time.
147 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 has more
148
149
150 choice
151 prompt "Instrumentation type"
152 depends on KERNEL_KASAN
153 default KERNEL_KASAN_OUTLINE
154
155 config KERNEL_KASAN_OUTLINE
156 bool "Outline instrumentation"
157 help
158 Before every memory access compiler insert function call
159 __asan_load*/__asan_store*. These functions performs check
160 of shadow memory. This is slower than inline instrumentation,
161 however it doesn't bloat size of kernel's .text section so
162 much as inline does.
163
164 config KERNEL_KASAN_INLINE
165 bool "Inline instrumentation"
166 help
167 Compiler directly inserts code checking shadow memory before
168 memory accesses. This is faster than outline (in some workloads
169 it gives about x2 boost over outline instrumentation), but
170 make kernel's .text size much bigger.
171 This requires a gcc version of 5.0 or later.
172
173 endchoice
174
175 config KERNEL_KCOV
176 bool "Compile the kernel with code coverage for fuzzing"
177 select KERNEL_DEBUG_FS
178 help
179 KCOV exposes kernel code coverage information in a form suitable
180 for coverage-guided fuzzing (randomized testing).
181
182 If RANDOMIZE_BASE is enabled, PC values will not be stable across
183 different machines and across reboots. If you need stable PC values,
184 disable RANDOMIZE_BASE.
185
186 For more details, see Documentation/kcov.txt.
187
188 config KERNEL_KCOV_ENABLE_COMPARISONS
189 bool "Enable comparison operands collection by KCOV"
190 depends on KERNEL_KCOV
191 help
192 KCOV also exposes operands of every comparison in the instrumented
193 code along with operand sizes and PCs of the comparison instructions.
194 These operands can be used by fuzzing engines to improve the quality
195 of fuzzing coverage.
196
197 config KERNEL_KCOV_INSTRUMENT_ALL
198 bool "Instrument all code by default"
199 depends on KERNEL_KCOV
200 default y if KERNEL_KCOV
201 help
202 If you are doing generic system call fuzzing (like e.g. syzkaller),
203 then you will want to instrument the whole kernel and you should
204 say y here. If you are doing more targeted fuzzing (like e.g.
205 filesystem fuzzing with AFL) then you will want to enable coverage
206 for more specific subsets of files, and should say n here.
207
208 config KERNEL_TASKSTATS
209 bool "Compile the kernel with task resource/io statistics and accounting"
210 default n
211 help
212 Enable the collection and publishing of task/io statistics and
213 accounting. Enable this option to enable i/o monitoring in system
214 monitors.
215
216 if KERNEL_TASKSTATS
217
218 config KERNEL_TASK_DELAY_ACCT
219 def_bool y
220
221 config KERNEL_TASK_IO_ACCOUNTING
222 def_bool y
223
224 config KERNEL_TASK_XACCT
225 def_bool y
226
227 endif
228
229 config KERNEL_KALLSYMS
230 bool "Compile the kernel with symbol table information"
231 default y if !SMALL_FLASH
232 help
233 This will give you more information in stack traces from kernel oopses.
234
235 config KERNEL_FTRACE
236 bool "Compile the kernel with tracing support"
237 depends on !TARGET_uml
238 default n
239
240 config KERNEL_FTRACE_SYSCALLS
241 bool "Trace system calls"
242 depends on KERNEL_FTRACE
243 default n
244
245 config KERNEL_ENABLE_DEFAULT_TRACERS
246 bool "Trace process context switches and events"
247 depends on KERNEL_FTRACE
248 default n
249
250 config KERNEL_FUNCTION_TRACER
251 bool "Function tracer"
252 depends on KERNEL_FTRACE
253 default n
254
255 config KERNEL_FUNCTION_GRAPH_TRACER
256 bool "Function graph tracer"
257 depends on KERNEL_FUNCTION_TRACER
258 default n
259
260 config KERNEL_DYNAMIC_FTRACE
261 bool "Enable/disable function tracing dynamically"
262 depends on KERNEL_FUNCTION_TRACER
263 default n
264
265 config KERNEL_FUNCTION_PROFILER
266 bool "Function profiler"
267 depends on KERNEL_FUNCTION_TRACER
268 default n
269
270 config KERNEL_DEBUG_KERNEL
271 bool
272 default n
273
274 config KERNEL_DEBUG_INFO
275 bool "Compile the kernel with debug information"
276 default y if !SMALL_FLASH
277 select KERNEL_DEBUG_KERNEL
278 help
279 This will compile your kernel and modules with debug information.
280
281 config KERNEL_DEBUG_LL_UART_NONE
282 bool
283 default n
284 depends on arm
285
286 config KERNEL_DEBUG_LL
287 bool
288 default n
289 depends on arm
290 select KERNEL_DEBUG_LL_UART_NONE
291 help
292 ARM low level debugging.
293
294 config KERNEL_DYNAMIC_DEBUG
295 bool "Compile the kernel with dynamic printk"
296 select KERNEL_DEBUG_FS
297 default n
298 help
299 Compiles debug level messages into the kernel, which would not
300 otherwise be available at runtime. These messages can then be
301 enabled/disabled based on various levels of scope - per source file,
302 function, module, format string, and line number. This mechanism
303 implicitly compiles in all pr_debug() and dev_dbg() calls, which
304 enlarges the kernel text size by about 2%.
305
306 config KERNEL_EARLY_PRINTK
307 bool "Compile the kernel with early printk"
308 default y if TARGET_bcm53xx
309 default n
310 depends on arm
311 select KERNEL_DEBUG_KERNEL
312 select KERNEL_DEBUG_LL if arm
313 help
314 Compile the kernel with early printk support. This is only useful for
315 debugging purposes to send messages over the serial console in early boot.
316 Enable this to debug early boot problems.
317
318 config KERNEL_KPROBES
319 bool "Compile the kernel with kprobes support"
320 default n
321 select KERNEL_FTRACE
322 select KERNEL_PERF_EVENTS
323 help
324 Compiles the kernel with KPROBES support, which allows you to trap
325 at almost any kernel address and execute a callback function.
326 register_kprobe() establishes a probepoint and specifies the
327 callback. Kprobes is useful for kernel debugging, non-intrusive
328 instrumentation and testing.
329 If in doubt, say "N".
330
331 config KERNEL_KPROBE_EVENT
332 bool
333 default y if KERNEL_KPROBES
334
335 config KERNEL_KPROBE_EVENTS
336 bool
337 default y if KERNEL_KPROBES
338
339 config KERNEL_AIO
340 bool "Compile the kernel with asynchronous IO support"
341 default y if !SMALL_FLASH
342
343 config KERNEL_FHANDLE
344 bool "Compile the kernel with support for fhandle syscalls"
345 default y if !SMALL_FLASH
346
347 config KERNEL_FANOTIFY
348 bool "Compile the kernel with modern file notification support"
349 default y if !SMALL_FLASH
350
351 config KERNEL_BLK_DEV_BSG
352 bool "Compile the kernel with SCSI generic v4 support for any block device"
353 default n
354
355 config KERNEL_MAGIC_SYSRQ
356 bool "Compile the kernel with SysRq support"
357 default y
358
359 config KERNEL_DEBUG_PINCTRL
360 bool "Compile the kernel with pinctrl debugging"
361 select KERNEL_DEBUG_KERNEL
362
363 config KERNEL_DEBUG_GPIO
364 bool "Compile the kernel with gpio debugging"
365 select KERNEL_DEBUG_KERNEL
366
367 config KERNEL_COREDUMP
368 bool
369
370 config KERNEL_ELF_CORE
371 bool "Enable process core dump support"
372 select KERNEL_COREDUMP
373 default y if !SMALL_FLASH
374
375 config KERNEL_PROVE_LOCKING
376 bool "Enable kernel lock checking"
377 select KERNEL_DEBUG_KERNEL
378 default n
379
380 config KERNEL_PRINTK_TIME
381 bool "Enable printk timestamps"
382 default y
383
384 config KERNEL_SLUB_DEBUG
385 bool
386
387 config KERNEL_SLUB_DEBUG_ON
388 bool
389
390 config KERNEL_SLABINFO
391 select KERNEL_SLUB_DEBUG
392 select KERNEL_SLUB_DEBUG_ON
393 bool "Enable /proc slab debug info"
394
395 config KERNEL_PROC_PAGE_MONITOR
396 bool "Enable /proc page monitoring"
397
398 config KERNEL_RELAY
399 bool
400
401 config KERNEL_KEXEC
402 bool "Enable kexec support"
403
404 config KERNEL_PROC_VMCORE
405 bool
406
407 config KERNEL_CRASH_DUMP
408 depends on i386 || x86_64 || arm || armeb
409 select KERNEL_KEXEC
410 select KERNEL_PROC_VMCORE
411 bool "Enable support for kexec crashdump"
412 default y
413
414 config USE_RFKILL
415 bool "Enable rfkill support"
416 default RFKILL_SUPPORT
417
418 config USE_SPARSE
419 bool "Enable sparse check during kernel build"
420 default n
421
422 config KERNEL_DEVTMPFS
423 bool "Compile the kernel with device tmpfs enabled"
424 default n
425 help
426 devtmpfs is a simple, kernel-managed /dev filesystem. The kernel creates
427 devices nodes for all registered devices to simplify boot, but leaves more
428 complex tasks to userspace (e.g. udev).
429
430 if KERNEL_DEVTMPFS
431
432 config KERNEL_DEVTMPFS_MOUNT
433 bool "Automatically mount devtmpfs after root filesystem is mounted"
434 default n
435
436 endif
437
438 config KERNEL_KEYS
439 bool "Enable kernel access key retention support"
440 default n
441
442 config KERNEL_PERSISTENT_KEYRINGS
443 bool "Enable kernel persistent keyrings"
444 depends on KERNEL_KEYS
445 default n
446
447 config KERNEL_BIG_KEYS
448 bool "Enable large payload keys on kernel keyrings"
449 depends on KERNEL_KEYS
450 default n
451
452 config KERNEL_ENCRYPTED_KEYS
453 tristate "Enable keys with encrypted payloads on kernel keyrings"
454 depends on KERNEL_KEYS
455 default n
456
457 #
458 # CGROUP support symbols
459 #
460
461 config KERNEL_CGROUPS
462 bool "Enable kernel cgroups"
463 default y if !SMALL_FLASH
464
465 if KERNEL_CGROUPS
466
467 config KERNEL_CGROUP_DEBUG
468 bool "Example debug cgroup subsystem"
469 default n
470 help
471 This option enables a simple cgroup subsystem that
472 exports useful debugging information about the cgroups
473 framework.
474
475 config KERNEL_FREEZER
476 bool
477 default y if KERNEL_CGROUP_FREEZER
478
479 config KERNEL_CGROUP_FREEZER
480 bool "Freezer cgroup subsystem"
481 default y
482 help
483 Provides a way to freeze and unfreeze all tasks in a
484 cgroup.
485
486 config KERNEL_CGROUP_DEVICE
487 bool "Device controller for cgroups"
488 default y
489 help
490 Provides a cgroup implementing whitelists for devices which
491 a process in the cgroup can mknod or open.
492
493 config KERNEL_CGROUP_PIDS
494 bool "PIDs cgroup subsystem"
495 default y
496 help
497 Provides enforcement of process number limits in the scope of a
498 cgroup.
499
500 config KERNEL_CPUSETS
501 bool "Cpuset support"
502 default y if !SMALL_FLASH
503 help
504 This option will let you create and manage CPUSETs which
505 allow dynamically partitioning a system into sets of CPUs and
506 Memory Nodes and assigning tasks to run only within those sets.
507 This is primarily useful on large SMP or NUMA systems.
508
509 config KERNEL_PROC_PID_CPUSET
510 bool "Include legacy /proc/<pid>/cpuset file"
511 default n
512 depends on KERNEL_CPUSETS
513
514 config KERNEL_CGROUP_CPUACCT
515 bool "Simple CPU accounting cgroup subsystem"
516 default y if !SMALL_FLASH
517 help
518 Provides a simple Resource Controller for monitoring the
519 total CPU consumed by the tasks in a cgroup.
520
521 config KERNEL_RESOURCE_COUNTERS
522 bool "Resource counters"
523 default y if !SMALL_FLASH
524 help
525 This option enables controller independent resource accounting
526 infrastructure that works with cgroups.
527
528 config KERNEL_MM_OWNER
529 bool
530 default y if KERNEL_MEMCG
531
532 config KERNEL_MEMCG
533 bool "Memory Resource Controller for Control Groups"
534 default y if !SMALL_FLASH
535 depends on KERNEL_RESOURCE_COUNTERS || !LINUX_3_18
536 help
537 Provides a memory resource controller that manages both anonymous
538 memory and page cache. (See Documentation/cgroups/memory.txt)
539
540 Note that setting this option increases fixed memory overhead
541 associated with each page of memory in the system. By this,
542 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
543 usage tracking struct at boot. Total amount of this is printed out
544 at boot.
545
546 Only enable when you're ok with these tradeoffs and really
547 sure you need the memory resource controller. Even when you enable
548 this, you can set "cgroup_disable=memory" at your boot option to
549 disable memory resource controller and you can avoid overheads
550 (but lose benefits of memory resource controller).
551
552 This config option also selects MM_OWNER config option, which
553 could in turn add some fork/exit overhead.
554
555 config KERNEL_MEMCG_SWAP
556 bool "Memory Resource Controller Swap Extension"
557 default n
558 depends on KERNEL_MEMCG
559 help
560 Add swap management feature to memory resource controller. When you
561 enable this, you can limit mem+swap usage per cgroup. In other words,
562 when you disable this, memory resource controller has no cares to
563 usage of swap...a process can exhaust all of the swap. This extension
564 is useful when you want to avoid exhaustion swap but this itself
565 adds more overheads and consumes memory for remembering information.
566 Especially if you use 32bit system or small memory system, please
567 be careful about enabling this. When memory resource controller
568 is disabled by boot option, this will be automatically disabled and
569 there will be no overhead from this. Even when you set this config=y,
570 if boot option "swapaccount=0" is set, swap will not be accounted.
571 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
572 size is 4096bytes, 512k per 1Gbytes of swap.
573
574 config KERNEL_MEMCG_SWAP_ENABLED
575 bool "Memory Resource Controller Swap Extension enabled by default"
576 default n
577 depends on KERNEL_MEMCG_SWAP
578 help
579 Memory Resource Controller Swap Extension comes with its price in
580 a bigger memory consumption. General purpose distribution kernels
581 which want to enable the feature but keep it disabled by default
582 and let the user enable it by swapaccount boot command line
583 parameter should have this option unselected.
584
585 Those who want to have the feature enabled by default should
586 select this option (if, for some reason, they need to disable it,
587 then swapaccount=0 does the trick).
588
589
590 config KERNEL_MEMCG_KMEM
591 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
592 default y if !SMALL_FLASH
593 depends on KERNEL_MEMCG
594 help
595 The Kernel Memory extension for Memory Resource Controller can limit
596 the amount of memory used by kernel objects in the system. Those are
597 fundamentally different from the entities handled by the standard
598 Memory Controller, which are page-based, and can be swapped. Users of
599 the kmem extension can use it to guarantee that no group of processes
600 will ever exhaust kernel resources alone.
601
602 config KERNEL_CGROUP_PERF
603 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
604 select KERNEL_PERF_EVENTS
605 default n
606 help
607 This option extends the per-cpu mode to restrict monitoring to
608 threads which belong to the cgroup specified and run on the
609 designated cpu.
610
611 menuconfig KERNEL_CGROUP_SCHED
612 bool "Group CPU scheduler"
613 default y if !SMALL_FLASH
614 help
615 This feature lets CPU scheduler recognize task groups and control CPU
616 bandwidth allocation to such task groups. It uses cgroups to group
617 tasks.
618
619 if KERNEL_CGROUP_SCHED
620
621 config KERNEL_FAIR_GROUP_SCHED
622 bool "Group scheduling for SCHED_OTHER"
623 default y if !SMALL_FLASH
624
625 config KERNEL_CFS_BANDWIDTH
626 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
627 default n
628 depends on KERNEL_FAIR_GROUP_SCHED
629 help
630 This option allows users to define CPU bandwidth rates (limits) for
631 tasks running within the fair group scheduler. Groups with no limit
632 set are considered to be unconstrained and will run with no
633 restriction.
634 See tip/Documentation/scheduler/sched-bwc.txt for more information.
635
636 config KERNEL_RT_GROUP_SCHED
637 bool "Group scheduling for SCHED_RR/FIFO"
638 default y if !SMALL_FLASH
639 help
640 This feature lets you explicitly allocate real CPU bandwidth
641 to task groups. If enabled, it will also make it impossible to
642 schedule realtime tasks for non-root users until you allocate
643 realtime bandwidth for them.
644
645 endif
646
647 config KERNEL_BLK_CGROUP
648 bool "Block IO controller"
649 default y
650 help
651 Generic block IO controller cgroup interface. This is the common
652 cgroup interface which should be used by various IO controlling
653 policies.
654
655 Currently, CFQ IO scheduler uses it to recognize task groups and
656 control disk bandwidth allocation (proportional time slice allocation)
657 to such task groups. It is also used by bio throttling logic in
658 block layer to implement upper limit in IO rates on a device.
659
660 This option only enables generic Block IO controller infrastructure.
661 One needs to also enable actual IO controlling logic/policy. For
662 enabling proportional weight division of disk bandwidth in CFQ, set
663 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
664 CONFIG_BLK_DEV_THROTTLING=y.
665
666 if KERNEL_BLK_CGROUP
667
668 config KERNEL_CFQ_GROUP_IOSCHED
669 bool "Proportional weight of disk bandwidth in CFQ"
670
671 config KERNEL_BLK_DEV_THROTTLING
672 bool "Enable throttling policy"
673 default y if TARGET_bcm27xx
674
675 config KERNEL_BLK_DEV_THROTTLING_LOW
676 bool "Block throttling .low limit interface support (EXPERIMENTAL)"
677 depends on KERNEL_BLK_DEV_THROTTLING
678 endif
679
680 config KERNEL_DEBUG_BLK_CGROUP
681 bool "Enable Block IO controller debugging"
682 default n
683 depends on KERNEL_BLK_CGROUP
684 help
685 Enable some debugging help. Currently it exports additional stat
686 files in a cgroup which can be useful for debugging.
687
688 config KERNEL_NET_CLS_CGROUP
689 bool "Control Group Classifier"
690 default y
691
692 config KERNEL_NETPRIO_CGROUP
693 bool "Network priority cgroup"
694 default y
695
696 endif
697
698 #
699 # Namespace support symbols
700 #
701
702 config KERNEL_NAMESPACES
703 bool "Enable kernel namespaces"
704 default y if !SMALL_FLASH
705
706 if KERNEL_NAMESPACES
707
708 config KERNEL_UTS_NS
709 bool "UTS namespace"
710 default y
711 help
712 In this namespace, tasks see different info provided
713 with the uname() system call.
714
715 config KERNEL_IPC_NS
716 bool "IPC namespace"
717 default y
718 help
719 In this namespace, tasks work with IPC ids which correspond to
720 different IPC objects in different namespaces.
721
722 config KERNEL_USER_NS
723 bool "User namespace (EXPERIMENTAL)"
724 default y
725 help
726 This allows containers, i.e. vservers, to use user namespaces
727 to provide different user info for different servers.
728
729 config KERNEL_PID_NS
730 bool "PID Namespaces"
731 default y
732 help
733 Support process id namespaces. This allows having multiple
734 processes with the same pid as long as they are in different
735 pid namespaces. This is a building block of containers.
736
737 config KERNEL_NET_NS
738 bool "Network namespace"
739 default y
740 help
741 Allow user space to create what appear to be multiple instances
742 of the network stack.
743
744 endif
745
746 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
747 bool "Support multiple instances of devpts"
748 default y if !SMALL_FLASH
749 help
750 Enable support for multiple instances of devpts filesystem.
751 If you want to have isolated PTY namespaces (eg: in containers),
752 say Y here. Otherwise, say N. If enabled, each mount of devpts
753 filesystem with the '-o newinstance' option will create an
754 independent PTY namespace.
755
756 config KERNEL_POSIX_MQUEUE
757 bool "POSIX Message Queues"
758 default y if !SMALL_FLASH
759 help
760 POSIX variant of message queues is a part of IPC. In POSIX message
761 queues every message has a priority which decides about succession
762 of receiving it by a process. If you want to compile and run
763 programs written e.g. for Solaris with use of its POSIX message
764 queues (functions mq_*) say Y here.
765
766 POSIX message queues are visible as a filesystem called 'mqueue'
767 and can be mounted somewhere if you want to do filesystem
768 operations on message queues.
769
770
771 config KERNEL_SECCOMP_FILTER
772 bool
773 default y if !SMALL_FLASH
774
775 config KERNEL_SECCOMP
776 bool "Enable seccomp support"
777 depends on !(TARGET_uml)
778 select KERNEL_SECCOMP_FILTER
779 default y if !SMALL_FLASH
780 help
781 Build kernel with support for seccomp.
782
783 #
784 # IPv4 configuration
785 #
786
787 config KERNEL_IP_MROUTE
788 bool "Enable IPv4 multicast routing"
789 default y
790 help
791 Multicast routing requires a multicast routing daemon in
792 addition to kernel support.
793
794 #
795 # IPv6 configuration
796 #
797
798 config KERNEL_IPV6
799 def_bool IPV6
800
801 if KERNEL_IPV6
802
803 config KERNEL_IPV6_MULTIPLE_TABLES
804 def_bool y
805
806 config KERNEL_IPV6_SUBTREES
807 def_bool y
808
809 config KERNEL_IPV6_MROUTE
810 bool "Enable IPv6 multicast routing"
811 default y
812 help
813 Multicast routing requires a multicast routing daemon in
814 addition to kernel support.
815
816 config KERNEL_IPV6_PIMSM_V2
817 def_bool n
818
819 endif
820
821 #
822 # NFS related symbols
823 #
824 config KERNEL_IP_PNP
825 bool "Compile the kernel with rootfs on NFS"
826 help
827 If you want to make your kernel boot off a NFS server as root
828 filesystem, select Y here.
829
830 if KERNEL_IP_PNP
831
832 config KERNEL_IP_PNP_DHCP
833 def_bool y
834
835 config KERNEL_IP_PNP_BOOTP
836 def_bool n
837
838 config KERNEL_IP_PNP_RARP
839 def_bool n
840
841 config KERNEL_NFS_FS
842 def_bool y
843
844 config KERNEL_NFS_V2
845 def_bool y
846
847 config KERNEL_NFS_V3
848 def_bool y
849
850 config KERNEL_ROOT_NFS
851 def_bool y
852
853 endif
854
855 menu "Filesystem ACL and attr support options"
856 config USE_FS_ACL_ATTR
857 bool "Use filesystem ACL and attr support by default"
858 default n
859 help
860 Make using ACLs (e.g. POSIX ACL, NFSv4 ACL) the default
861 for kernel and packages, except tmpfs, flash filesystems,
862 and old NFS. Also enable userspace extended attribute support
863 by default. (OpenWrt already has an expection it will be
864 present in the kernel).
865
866 config KERNEL_FS_POSIX_ACL
867 bool "Enable POSIX ACL support"
868 default y if USE_FS_ACL_ATTR
869
870 config KERNEL_BTRFS_FS_POSIX_ACL
871 bool "Enable POSIX ACL for BtrFS Filesystems"
872 select KERNEL_FS_POSIX_ACL
873 default y if USE_FS_ACL_ATTR
874
875 config KERNEL_EXT4_FS_POSIX_ACL
876 bool "Enable POSIX ACL for Ext4 Filesystems"
877 select KERNEL_FS_POSIX_ACL
878 default y if USE_FS_ACL_ATTR
879
880 config KERNEL_F2FS_FS_POSIX_ACL
881 bool "Enable POSIX ACL for F2FS Filesystems"
882 select KERNEL_FS_POSIX_ACL
883 default n
884
885 config KERNEL_JFFS2_FS_POSIX_ACL
886 bool "Enable POSIX ACL for JFFS2 Filesystems"
887 select KERNEL_FS_POSIX_ACL
888 default n
889
890 config KERNEL_TMPFS_POSIX_ACL
891 bool "Enable POSIX ACL for TMPFS Filesystems"
892 select KERNEL_FS_POSIX_ACL
893 default n
894
895 config KERNEL_CIFS_ACL
896 bool "Enable CIFS ACLs"
897 select KERNEL_FS_POSIX_ACL
898 default y if USE_FS_ACL_ATTR
899
900 config KERNEL_HFS_FS_POSIX_ACL
901 bool "Enable POSIX ACL for HFS Filesystems"
902 select KERNEL_FS_POSIX_ACL
903 default y if USE_FS_ACL_ATTR
904
905 config KERNEL_HFSPLUS_FS_POSIX_ACL
906 bool "Enable POSIX ACL for HFS+ Filesystems"
907 select KERNEL_FS_POSIX_ACL
908 default y if USE_FS_ACL_ATTR
909
910 config KERNEL_NFS_ACL_SUPPORT
911 bool "Enable ACLs for NFS"
912 default y if USE_FS_ACL_ATTR
913
914 config KERNEL_NFS_V3_ACL_SUPPORT
915 bool "Enable ACLs for NFSv3"
916 default n
917
918 config KERNEL_NFSD_V2_ACL_SUPPORT
919 bool "Enable ACLs for NFSDv2"
920 default n
921
922 config KERNEL_NFSD_V3_ACL_SUPPORT
923 bool "Enable ACLs for NFSDv3"
924 default n
925
926 config KERNEL_REISER_FS_POSIX_ACL
927 bool "Enable POSIX ACLs for ReiserFS"
928 select KERNEL_FS_POSIX_ACL
929 default y if USE_FS_ACL_ATTR
930
931 config KERNEL_XFS_POSIX_ACL
932 bool "Enable POSIX ACLs for XFS"
933 select KERNEL_FS_POSIX_ACL
934 default y if USE_FS_ACL_ATTR
935
936 config KERNEL_JFS_POSIX_ACL
937 bool "Enable POSIX ACLs for JFS"
938 select KERNEL_FS_POSIX_ACL
939 default y if USE_FS_ACL_ATTR
940
941 endmenu
942
943 config KERNEL_DEVMEM
944 bool "/dev/mem virtual device support"
945 help
946 Say Y here if you want to support the /dev/mem device.
947 The /dev/mem device is used to access areas of physical
948 memory.
949
950 config KERNEL_DEVKMEM
951 bool "/dev/kmem virtual device support"
952 help
953 Say Y here if you want to support the /dev/kmem device. The
954 /dev/kmem device is rarely used, but can be used for certain
955 kind of kernel debugging operations.
956
957 config KERNEL_SQUASHFS_FRAGMENT_CACHE_SIZE
958 int "Number of squashfs fragments cached"
959 default 2 if (SMALL_FLASH && !LOW_MEMORY_FOOTPRINT)
960 default 3
961
962 #
963 # compile optimiziation setting
964 #
965 choice
966 prompt "Compiler optimization level"
967 default KERNEL_CC_OPTIMIZE_FOR_SIZE if SMALL_FLASH
968
969 config KERNEL_CC_OPTIMIZE_FOR_PERFORMANCE
970 bool "Optimize for performance"
971 help
972 This is the default optimization level for the kernel, building
973 with the "-O2" compiler flag for best performance and most
974 helpful compile-time warnings.
975
976 config KERNEL_CC_OPTIMIZE_FOR_SIZE
977 bool "Optimize for size"
978 help
979 Enabling this option will pass "-Os" instead of "-O2" to
980 your compiler resulting in a smaller kernel.
981
982 endchoice