1 # Copyright (C) 2006-2014 OpenWrt.org
3 # This is free software, licensed under the GNU General Public License v2.
4 # See /LICENSE for more information.
7 config KERNEL_BUILD_USER
8 string "Custom Kernel Build User Name"
9 default "builder" if BUILDBOT
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.
16 config KERNEL_BUILD_DOMAIN
17 string "Custom Kernel Build Domain Name"
18 default "buildhost" if BUILDBOT
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.
26 bool "Enable support for printk"
29 config KERNEL_CRASHLOG
31 depends on !(arm || powerpc || sparc || TARGET_uml || i386 || x86_64)
35 bool "Support for paging of anonymous memory (swap)"
36 default y if !SMALL_FLASH
38 config KERNEL_DEBUG_FS
39 bool "Compile the kernel with debug filesystem enabled"
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.
47 config KERNEL_MIPS_FP_SUPPORT
53 depends on (arm || aarch64)
55 config KERNEL_X86_VSYSCALL_EMULATION
56 bool "Enable vsyscall emulation"
60 This enables emulation of the legacy vsyscall page. Disabling
61 it is roughly equivalent to booting with vsyscall=none, except
62 that it will also disable the helpful warning if a program
63 tries to use a vsyscall. With this option set to N, offending
64 programs will just segfault, citing addresses of the form
67 This option is required by many programs built before 2013, and
68 care should be used even with newer programs if set to N.
70 Disabling this option saves about 7K of kernel size and
71 possibly 4K of additional runtime pagetable memory.
73 config KERNEL_PERF_EVENTS
74 bool "Compile the kernel with performance events and counters"
76 select KERNEL_ARM_PMU if (arm || aarch64)
78 config KERNEL_PROFILING
79 bool "Compile the kernel with profiling enabled"
81 select KERNEL_PERF_EVENTS
83 Enable the extended profiling support mechanisms used by profilers such
87 bool "Compile the kernel with undefined behaviour sanity checker"
89 This option enables undefined behaviour sanity checker
90 Compile-time instrumentation is used to detect various undefined
91 behaviours in runtime. Various types of checks may be enabled
92 via boot parameter ubsan_handle
93 (see: Documentation/dev-tools/ubsan.rst).
95 config KERNEL_UBSAN_SANITIZE_ALL
96 bool "Enable instrumentation for the entire kernel"
97 depends on KERNEL_UBSAN
100 This option activates instrumentation for the entire kernel.
101 If you don't enable this option, you have to explicitly specify
102 UBSAN_SANITIZE := y for the files/directories you want to check for UB.
103 Enabling this option will get kernel image size increased
106 config KERNEL_UBSAN_ALIGNMENT
107 bool "Enable checking of pointers alignment"
108 depends on KERNEL_UBSAN
110 This option enables detection of unaligned memory accesses.
111 Enabling this option on architectures that support unaligned
112 accesses may produce a lot of false positives.
114 config KERNEL_UBSAN_NULL
115 bool "Enable checking of null pointers"
116 depends on KERNEL_UBSAN
118 This option enables detection of memory accesses via a
122 bool "Compile the kernel with KASan: runtime memory debugger"
123 select KERNEL_SLUB_DEBUG
124 depends on (x86_64 || aarch64)
126 Enables kernel address sanitizer - runtime memory debugger,
127 designed to find out-of-bounds accesses and use-after-free bugs.
128 This is strictly a debugging feature and it requires a gcc version
129 of 4.9.2 or later. Detection of out of bounds accesses to stack or
130 global variables requires gcc 5.0 or later.
131 This feature consumes about 1/8 of available memory and brings about
132 ~x3 performance slowdown.
133 For better error detection enable CONFIG_STACKTRACE.
134 Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
135 (the resulting kernel does not boot).
137 config KERNEL_KASAN_EXTRA
138 bool "KAsan: extra checks"
139 depends on KERNEL_KASAN && KERNEL_DEBUG_KERNEL
141 This enables further checks in the kernel address sanitizer, for now
142 it only includes the address-use-after-scope check that can lead
143 to excessive kernel stack usage, frame size warnings and longer
145 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 has more
149 prompt "Instrumentation type"
150 depends on KERNEL_KASAN
151 default KERNEL_KASAN_OUTLINE
153 config KERNEL_KASAN_OUTLINE
154 bool "Outline instrumentation"
156 Before every memory access compiler insert function call
157 __asan_load*/__asan_store*. These functions performs check
158 of shadow memory. This is slower than inline instrumentation,
159 however it doesn't bloat size of kernel's .text section so
162 config KERNEL_KASAN_INLINE
163 bool "Inline instrumentation"
165 Compiler directly inserts code checking shadow memory before
166 memory accesses. This is faster than outline (in some workloads
167 it gives about x2 boost over outline instrumentation), but
168 make kernel's .text size much bigger.
169 This requires a gcc version of 5.0 or later.
174 bool "Compile the kernel with code coverage for fuzzing"
175 select KERNEL_DEBUG_FS
177 KCOV exposes kernel code coverage information in a form suitable
178 for coverage-guided fuzzing (randomized testing).
180 If RANDOMIZE_BASE is enabled, PC values will not be stable across
181 different machines and across reboots. If you need stable PC values,
182 disable RANDOMIZE_BASE.
184 For more details, see Documentation/kcov.txt.
186 config KERNEL_KCOV_ENABLE_COMPARISONS
187 bool "Enable comparison operands collection by KCOV"
188 depends on KERNEL_KCOV
190 KCOV also exposes operands of every comparison in the instrumented
191 code along with operand sizes and PCs of the comparison instructions.
192 These operands can be used by fuzzing engines to improve the quality
195 config KERNEL_KCOV_INSTRUMENT_ALL
196 bool "Instrument all code by default"
197 depends on KERNEL_KCOV
198 default y if KERNEL_KCOV
200 If you are doing generic system call fuzzing (like e.g. syzkaller),
201 then you will want to instrument the whole kernel and you should
202 say y here. If you are doing more targeted fuzzing (like e.g.
203 filesystem fuzzing with AFL) then you will want to enable coverage
204 for more specific subsets of files, and should say n here.
206 config KERNEL_TASKSTATS
207 bool "Compile the kernel with task resource/io statistics and accounting"
210 Enable the collection and publishing of task/io statistics and
211 accounting. Enable this option to enable i/o monitoring in system
216 config KERNEL_TASK_DELAY_ACCT
219 config KERNEL_TASK_IO_ACCOUNTING
222 config KERNEL_TASK_XACCT
227 config KERNEL_KALLSYMS
228 bool "Compile the kernel with symbol table information"
229 default y if !SMALL_FLASH
231 This will give you more information in stack traces from kernel oopses.
234 bool "Compile the kernel with tracing support"
235 depends on !TARGET_uml
238 config KERNEL_FTRACE_SYSCALLS
239 bool "Trace system calls"
240 depends on KERNEL_FTRACE
243 config KERNEL_ENABLE_DEFAULT_TRACERS
244 bool "Trace process context switches and events"
245 depends on KERNEL_FTRACE
248 config KERNEL_FUNCTION_TRACER
249 bool "Function tracer"
250 depends on KERNEL_FTRACE
253 config KERNEL_FUNCTION_GRAPH_TRACER
254 bool "Function graph tracer"
255 depends on KERNEL_FUNCTION_TRACER
258 config KERNEL_DYNAMIC_FTRACE
259 bool "Enable/disable function tracing dynamically"
260 depends on KERNEL_FUNCTION_TRACER
263 config KERNEL_FUNCTION_PROFILER
264 bool "Function profiler"
265 depends on KERNEL_FUNCTION_TRACER
268 config KERNEL_DEBUG_KERNEL
272 config KERNEL_DEBUG_INFO
273 bool "Compile the kernel with debug information"
274 default y if !SMALL_FLASH
275 select KERNEL_DEBUG_KERNEL
277 This will compile your kernel and modules with debug information.
279 config KERNEL_DEBUG_LL_UART_NONE
284 config KERNEL_DEBUG_LL
288 select KERNEL_DEBUG_LL_UART_NONE
290 ARM low level debugging.
292 config KERNEL_DYNAMIC_DEBUG
293 bool "Compile the kernel with dynamic printk"
294 select KERNEL_DEBUG_FS
297 Compiles debug level messages into the kernel, which would not
298 otherwise be available at runtime. These messages can then be
299 enabled/disabled based on various levels of scope - per source file,
300 function, module, format string, and line number. This mechanism
301 implicitly compiles in all pr_debug() and dev_dbg() calls, which
302 enlarges the kernel text size by about 2%.
304 config KERNEL_EARLY_PRINTK
305 bool "Compile the kernel with early printk"
306 default y if TARGET_bcm53xx
309 select KERNEL_DEBUG_KERNEL
310 select KERNEL_DEBUG_LL if arm
312 Compile the kernel with early printk support. This is only useful for
313 debugging purposes to send messages over the serial console in early boot.
314 Enable this to debug early boot problems.
316 config KERNEL_KPROBES
317 bool "Compile the kernel with kprobes support"
320 select KERNEL_PERF_EVENTS
322 Compiles the kernel with KPROBES support, which allows you to trap
323 at almost any kernel address and execute a callback function.
324 register_kprobe() establishes a probepoint and specifies the
325 callback. Kprobes is useful for kernel debugging, non-intrusive
326 instrumentation and testing.
327 If in doubt, say "N".
329 config KERNEL_KPROBE_EVENT
331 default y if KERNEL_KPROBES
333 config KERNEL_KPROBE_EVENTS
335 default y if KERNEL_KPROBES
338 bool "Compile the kernel with asynchronous IO support"
339 default y if !SMALL_FLASH
341 config KERNEL_FHANDLE
342 bool "Compile the kernel with support for fhandle syscalls"
343 default y if !SMALL_FLASH
345 config KERNEL_FANOTIFY
346 bool "Compile the kernel with modern file notification support"
347 default y if !SMALL_FLASH
349 config KERNEL_BLK_DEV_BSG
350 bool "Compile the kernel with SCSI generic v4 support for any block device"
353 config KERNEL_TRANSPARENT_HUGEPAGE
357 prompt "Transparent Hugepage Support sysfs defaults"
358 depends on KERNEL_TRANSPARENT_HUGEPAGE
359 default KERNEL_TRANSPARENT_HUGEPAGE_ALWAYS
361 config KERNEL_TRANSPARENT_HUGEPAGE_ALWAYS
364 config KERNEL_TRANSPARENT_HUGEPAGE_MADVISE
368 config KERNEL_HUGETLBFS
371 config KERNEL_HUGETLB_PAGE
372 bool "Compile the kernel with HugeTLB support"
373 select KERNEL_TRANSPARENT_HUGEPAGE
374 select KERNEL_HUGETLBFS
377 config KERNEL_MAGIC_SYSRQ
378 bool "Compile the kernel with SysRq support"
381 config KERNEL_DEBUG_PINCTRL
382 bool "Compile the kernel with pinctrl debugging"
383 select KERNEL_DEBUG_KERNEL
385 config KERNEL_DEBUG_GPIO
386 bool "Compile the kernel with gpio debugging"
387 select KERNEL_DEBUG_KERNEL
389 config KERNEL_COREDUMP
392 config KERNEL_ELF_CORE
393 bool "Enable process core dump support"
394 select KERNEL_COREDUMP
395 default y if !SMALL_FLASH
397 config KERNEL_PROVE_LOCKING
398 bool "Enable kernel lock checking"
399 select KERNEL_DEBUG_KERNEL
402 config KERNEL_LOCKUP_DETECTOR
403 bool "Compile the kernel with detect Hard and Soft Lockups"
404 depends on KERNEL_DEBUG_KERNEL
406 Say Y here to enable the kernel to act as a watchdog to detect
407 hard and soft lockups.
409 Softlockups are bugs that cause the kernel to loop in kernel
410 mode for more than 20 seconds, without giving other tasks a
411 chance to run. The current stack trace is displayed upon
412 detection and the system will stay locked up.
414 Hardlockups are bugs that cause the CPU to loop in kernel mode
415 for more than 10 seconds, without letting other interrupts have a
416 chance to run. The current stack trace is displayed upon detection
417 and the system will stay locked up.
419 The overhead should be minimal. A periodic hrtimer runs to
420 generate interrupts and kick the watchdog task every 4 seconds.
421 An NMI is generated every 10 seconds or so to check for hardlockups.
423 The frequency of hrtimer and NMI events and the soft and hard lockup
424 thresholds can be controlled through the sysctl watchdog_thresh.
426 config KERNEL_DETECT_HUNG_TASK
427 bool "Compile the kernel with detect Hung Tasks"
428 depends on KERNEL_DEBUG_KERNEL
429 default KERNEL_LOCKUP_DETECTOR
431 Say Y here to enable the kernel to detect "hung tasks",
432 which are bugs that cause the task to be stuck in
433 uninterruptible "D" state indefinitely.
435 When a hung task is detected, the kernel will print the
436 current stack trace (which you should report), but the
437 task will stay in uninterruptible state. If lockdep is
438 enabled then all held locks will also be reported. This
439 feature has negligible overhead.
441 config KERNEL_WQ_WATCHDOG
442 bool "Compile the kernel with detect Workqueue Stalls"
443 depends on KERNEL_DEBUG_KERNEL
445 Say Y here to enable stall detection on workqueues. If a
446 worker pool doesn't make forward progress on a pending work
447 item for over a given amount of time, 30s by default, a
448 warning message is printed along with dump of workqueue
449 state. This can be configured through kernel parameter
450 "workqueue.watchdog_thresh" and its sysfs counterpart.
452 config KERNEL_DEBUG_ATOMIC_SLEEP
453 bool "Compile the kernel with sleep inside atomic section checking"
454 depends on KERNEL_DEBUG_KERNEL
456 If you say Y here, various routines which may sleep will become very
457 noisy if they are called inside atomic sections: when a spinlock is
458 held, inside an rcu read side critical section, inside preempt disabled
459 sections, inside an interrupt, etc...
461 config KERNEL_DEBUG_VM
462 bool "Compile the kernel with debug VM"
463 depends on KERNEL_DEBUG_KERNEL
465 Enable this to turn on extended checks in the virtual-memory system
466 that may impact performance.
470 config KERNEL_PRINTK_TIME
471 bool "Enable printk timestamps"
474 config KERNEL_SLUB_DEBUG
477 config KERNEL_SLUB_DEBUG_ON
480 config KERNEL_SLABINFO
481 select KERNEL_SLUB_DEBUG
482 select KERNEL_SLUB_DEBUG_ON
483 bool "Enable /proc slab debug info"
485 config KERNEL_PROC_PAGE_MONITOR
486 bool "Enable /proc page monitoring"
492 bool "Enable kexec support"
494 config KERNEL_PROC_VMCORE
497 config KERNEL_PROC_KCORE
500 config KERNEL_CRASH_DUMP
501 depends on i386 || x86_64 || arm || armeb
503 select KERNEL_PROC_VMCORE
504 select KERNEL_PROC_KCORE
505 bool "Enable support for kexec crashdump"
509 bool "Enable rfkill support"
510 default RFKILL_SUPPORT
513 bool "Enable sparse check during kernel build"
516 config KERNEL_DEVTMPFS
517 bool "Compile the kernel with device tmpfs enabled"
520 devtmpfs is a simple, kernel-managed /dev filesystem. The kernel creates
521 devices nodes for all registered devices to simplify boot, but leaves more
522 complex tasks to userspace (e.g. udev).
526 config KERNEL_DEVTMPFS_MOUNT
527 bool "Automatically mount devtmpfs after root filesystem is mounted"
533 bool "Enable kernel access key retention support"
536 config KERNEL_PERSISTENT_KEYRINGS
537 bool "Enable kernel persistent keyrings"
538 depends on KERNEL_KEYS
541 config KERNEL_BIG_KEYS
542 bool "Enable large payload keys on kernel keyrings"
543 depends on KERNEL_KEYS
546 config KERNEL_ENCRYPTED_KEYS
547 tristate "Enable keys with encrypted payloads on kernel keyrings"
548 depends on KERNEL_KEYS
552 # CGROUP support symbols
555 config KERNEL_CGROUPS
556 bool "Enable kernel cgroups"
557 default y if !SMALL_FLASH
561 config KERNEL_CGROUP_DEBUG
562 bool "Example debug cgroup subsystem"
565 This option enables a simple cgroup subsystem that
566 exports useful debugging information about the cgroups
569 config KERNEL_FREEZER
572 config KERNEL_CGROUP_FREEZER
573 bool "legacy Freezer cgroup subsystem"
575 select KERNEL_FREEZER
577 Provides a way to freeze and unfreeze all tasks in a
579 (legacy cgroup1-only controller, in cgroup2 freezer
580 is integrated in the Memory controller)
582 config KERNEL_CGROUP_DEVICE
583 bool "legacy Device controller for cgroups"
586 Provides a cgroup implementing whitelists for devices which
587 a process in the cgroup can mknod or open.
588 (legacy cgroup1-only controller)
590 config KERNEL_CGROUP_HUGETLB
591 bool "HugeTLB controller"
593 select KERNEL_HUGETLB_PAGE
595 config KERNEL_CGROUP_PIDS
596 bool "PIDs cgroup subsystem"
599 Provides enforcement of process number limits in the scope of a
602 config KERNEL_CGROUP_RDMA
603 bool "RDMA controller for cgroups"
606 config KERNEL_CGROUP_BPF
607 bool "Support for eBPF programs attached to cgroups"
610 config KERNEL_CPUSETS
611 bool "Cpuset support"
614 This option will let you create and manage CPUSETs which
615 allow dynamically partitioning a system into sets of CPUs and
616 Memory Nodes and assigning tasks to run only within those sets.
617 This is primarily useful on large SMP or NUMA systems.
619 config KERNEL_PROC_PID_CPUSET
620 bool "Include legacy /proc/<pid>/cpuset file"
622 depends on KERNEL_CPUSETS
624 config KERNEL_CGROUP_CPUACCT
625 bool "Simple CPU accounting cgroup subsystem"
628 Provides a simple Resource Controller for monitoring the
629 total CPU consumed by the tasks in a cgroup.
631 config KERNEL_RESOURCE_COUNTERS
632 bool "Resource counters"
635 This option enables controller independent resource accounting
636 infrastructure that works with cgroups.
638 config KERNEL_MM_OWNER
640 default y if KERNEL_MEMCG
643 bool "Memory Resource Controller for Control Groups"
645 select KERNEL_FREEZER
646 depends on KERNEL_RESOURCE_COUNTERS || !LINUX_3_18
648 Provides a memory resource controller that manages both anonymous
649 memory and page cache. (See Documentation/cgroups/memory.txt)
651 Note that setting this option increases fixed memory overhead
652 associated with each page of memory in the system. By this,
653 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
654 usage tracking struct at boot. Total amount of this is printed out
657 Only enable when you're ok with these tradeoffs and really
658 sure you need the memory resource controller. Even when you enable
659 this, you can set "cgroup_disable=memory" at your boot option to
660 disable memory resource controller and you can avoid overheads
661 (but lose benefits of memory resource controller).
663 This config option also selects MM_OWNER config option, which
664 could in turn add some fork/exit overhead.
666 config KERNEL_MEMCG_SWAP
667 bool "Memory Resource Controller Swap Extension"
669 depends on KERNEL_MEMCG
671 Add swap management feature to memory resource controller. When you
672 enable this, you can limit mem+swap usage per cgroup. In other words,
673 when you disable this, memory resource controller has no cares to
674 usage of swap...a process can exhaust all of the swap. This extension
675 is useful when you want to avoid exhaustion swap but this itself
676 adds more overheads and consumes memory for remembering information.
677 Especially if you use 32bit system or small memory system, please
678 be careful about enabling this. When memory resource controller
679 is disabled by boot option, this will be automatically disabled and
680 there will be no overhead from this. Even when you set this config=y,
681 if boot option "swapaccount=0" is set, swap will not be accounted.
682 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
683 size is 4096bytes, 512k per 1Gbytes of swap.
685 config KERNEL_MEMCG_SWAP_ENABLED
686 bool "Memory Resource Controller Swap Extension enabled by default"
688 depends on KERNEL_MEMCG_SWAP
690 Memory Resource Controller Swap Extension comes with its price in
691 a bigger memory consumption. General purpose distribution kernels
692 which want to enable the feature but keep it disabled by default
693 and let the user enable it by swapaccount boot command line
694 parameter should have this option unselected.
696 Those who want to have the feature enabled by default should
697 select this option (if, for some reason, they need to disable it,
698 then swapaccount=0 does the trick).
701 config KERNEL_MEMCG_KMEM
702 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
704 depends on KERNEL_MEMCG
706 The Kernel Memory extension for Memory Resource Controller can limit
707 the amount of memory used by kernel objects in the system. Those are
708 fundamentally different from the entities handled by the standard
709 Memory Controller, which are page-based, and can be swapped. Users of
710 the kmem extension can use it to guarantee that no group of processes
711 will ever exhaust kernel resources alone.
713 config KERNEL_CGROUP_PERF
714 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
715 select KERNEL_PERF_EVENTS
718 This option extends the per-cpu mode to restrict monitoring to
719 threads which belong to the cgroup specified and run on the
722 menuconfig KERNEL_CGROUP_SCHED
723 bool "Group CPU scheduler"
726 This feature lets CPU scheduler recognize task groups and control CPU
727 bandwidth allocation to such task groups. It uses cgroups to group
730 if KERNEL_CGROUP_SCHED
732 config KERNEL_FAIR_GROUP_SCHED
733 bool "Group scheduling for SCHED_OTHER"
736 config KERNEL_CFS_BANDWIDTH
737 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
739 depends on KERNEL_FAIR_GROUP_SCHED
741 This option allows users to define CPU bandwidth rates (limits) for
742 tasks running within the fair group scheduler. Groups with no limit
743 set are considered to be unconstrained and will run with no
745 See tip/Documentation/scheduler/sched-bwc.txt for more information.
747 config KERNEL_RT_GROUP_SCHED
748 bool "Group scheduling for SCHED_RR/FIFO"
751 This feature lets you explicitly allocate real CPU bandwidth
752 to task groups. If enabled, it will also make it impossible to
753 schedule realtime tasks for non-root users until you allocate
754 realtime bandwidth for them.
758 config KERNEL_BLK_CGROUP
759 bool "Block IO controller"
762 Generic block IO controller cgroup interface. This is the common
763 cgroup interface which should be used by various IO controlling
766 Currently, CFQ IO scheduler uses it to recognize task groups and
767 control disk bandwidth allocation (proportional time slice allocation)
768 to such task groups. It is also used by bio throttling logic in
769 block layer to implement upper limit in IO rates on a device.
771 This option only enables generic Block IO controller infrastructure.
772 One needs to also enable actual IO controlling logic/policy. For
773 enabling proportional weight division of disk bandwidth in CFQ, set
774 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
775 CONFIG_BLK_DEV_THROTTLING=y.
779 config KERNEL_CFQ_GROUP_IOSCHED
780 bool "Proportional weight of disk bandwidth in CFQ"
782 config KERNEL_BLK_DEV_THROTTLING
783 bool "Enable throttling policy"
786 config KERNEL_BLK_DEV_THROTTLING_LOW
787 bool "Block throttling .low limit interface support (EXPERIMENTAL)"
788 depends on KERNEL_BLK_DEV_THROTTLING
791 config KERNEL_DEBUG_BLK_CGROUP
792 bool "Enable Block IO controller debugging"
794 depends on KERNEL_BLK_CGROUP
796 Enable some debugging help. Currently it exports additional stat
797 files in a cgroup which can be useful for debugging.
799 config KERNEL_NET_CLS_CGROUP
800 bool "legacy Control Group Classifier"
803 config KERNEL_CGROUP_NET_CLASSID
804 bool "legacy Network classid cgroup"
807 config KERNEL_CGROUP_NET_PRIO
808 bool "legacy Network priority cgroup"
814 # Namespace support symbols
817 config KERNEL_NAMESPACES
818 bool "Enable kernel namespaces"
819 default y if !SMALL_FLASH
827 In this namespace, tasks see different info provided
828 with the uname() system call.
834 In this namespace, tasks work with IPC ids which correspond to
835 different IPC objects in different namespaces.
837 config KERNEL_USER_NS
838 bool "User namespace (EXPERIMENTAL)"
841 This allows containers, i.e. vservers, to use user namespaces
842 to provide different user info for different servers.
845 bool "PID Namespaces"
848 Support process id namespaces. This allows having multiple
849 processes with the same pid as long as they are in different
850 pid namespaces. This is a building block of containers.
853 bool "Network namespace"
856 Allow user space to create what appear to be multiple instances
857 of the network stack.
861 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
862 bool "Support multiple instances of devpts"
863 default y if !SMALL_FLASH
865 Enable support for multiple instances of devpts filesystem.
866 If you want to have isolated PTY namespaces (eg: in containers),
867 say Y here. Otherwise, say N. If enabled, each mount of devpts
868 filesystem with the '-o newinstance' option will create an
869 independent PTY namespace.
871 config KERNEL_POSIX_MQUEUE
872 bool "POSIX Message Queues"
873 default y if !SMALL_FLASH
875 POSIX variant of message queues is a part of IPC. In POSIX message
876 queues every message has a priority which decides about succession
877 of receiving it by a process. If you want to compile and run
878 programs written e.g. for Solaris with use of its POSIX message
879 queues (functions mq_*) say Y here.
881 POSIX message queues are visible as a filesystem called 'mqueue'
882 and can be mounted somewhere if you want to do filesystem
883 operations on message queues.
886 config KERNEL_SECCOMP_FILTER
888 default y if !SMALL_FLASH
890 config KERNEL_SECCOMP
891 bool "Enable seccomp support"
892 depends on !(TARGET_uml)
893 select KERNEL_SECCOMP_FILTER
894 default y if !SMALL_FLASH
896 Build kernel with support for seccomp.
902 config KERNEL_IP_MROUTE
903 bool "Enable IPv4 multicast routing"
906 Multicast routing requires a multicast routing daemon in
907 addition to kernel support.
918 config KERNEL_IPV6_MULTIPLE_TABLES
921 config KERNEL_IPV6_SUBTREES
924 config KERNEL_IPV6_MROUTE
925 bool "Enable IPv6 multicast routing"
928 Multicast routing requires a multicast routing daemon in
929 addition to kernel support.
931 config KERNEL_IPV6_PIMSM_V2
937 # NFS related symbols
940 bool "Compile the kernel with rootfs on NFS"
942 If you want to make your kernel boot off a NFS server as root
943 filesystem, select Y here.
947 config KERNEL_IP_PNP_DHCP
950 config KERNEL_IP_PNP_BOOTP
953 config KERNEL_IP_PNP_RARP
965 config KERNEL_ROOT_NFS
970 menu "Filesystem ACL and attr support options"
971 config USE_FS_ACL_ATTR
972 bool "Use filesystem ACL and attr support by default"
975 Make using ACLs (e.g. POSIX ACL, NFSv4 ACL) the default
976 for kernel and packages, except tmpfs, flash filesystems,
977 and old NFS. Also enable userspace extended attribute support
978 by default. (OpenWrt already has an expection it will be
979 present in the kernel).
981 config KERNEL_FS_POSIX_ACL
982 bool "Enable POSIX ACL support"
983 default y if USE_FS_ACL_ATTR
985 config KERNEL_BTRFS_FS_POSIX_ACL
986 bool "Enable POSIX ACL for BtrFS Filesystems"
987 select KERNEL_FS_POSIX_ACL
988 default y if USE_FS_ACL_ATTR
990 config KERNEL_EXT4_FS_POSIX_ACL
991 bool "Enable POSIX ACL for Ext4 Filesystems"
992 select KERNEL_FS_POSIX_ACL
993 default y if USE_FS_ACL_ATTR
995 config KERNEL_F2FS_FS_POSIX_ACL
996 bool "Enable POSIX ACL for F2FS Filesystems"
997 select KERNEL_FS_POSIX_ACL
1000 config KERNEL_JFFS2_FS_POSIX_ACL
1001 bool "Enable POSIX ACL for JFFS2 Filesystems"
1002 select KERNEL_FS_POSIX_ACL
1005 config KERNEL_TMPFS_POSIX_ACL
1006 bool "Enable POSIX ACL for TMPFS Filesystems"
1007 select KERNEL_FS_POSIX_ACL
1010 config KERNEL_CIFS_ACL
1011 bool "Enable CIFS ACLs"
1012 select KERNEL_FS_POSIX_ACL
1013 default y if USE_FS_ACL_ATTR
1015 config KERNEL_HFS_FS_POSIX_ACL
1016 bool "Enable POSIX ACL for HFS Filesystems"
1017 select KERNEL_FS_POSIX_ACL
1018 default y if USE_FS_ACL_ATTR
1020 config KERNEL_HFSPLUS_FS_POSIX_ACL
1021 bool "Enable POSIX ACL for HFS+ Filesystems"
1022 select KERNEL_FS_POSIX_ACL
1023 default y if USE_FS_ACL_ATTR
1025 config KERNEL_NFS_ACL_SUPPORT
1026 bool "Enable ACLs for NFS"
1027 default y if USE_FS_ACL_ATTR
1029 config KERNEL_NFS_V3_ACL_SUPPORT
1030 bool "Enable ACLs for NFSv3"
1033 config KERNEL_NFSD_V2_ACL_SUPPORT
1034 bool "Enable ACLs for NFSDv2"
1037 config KERNEL_NFSD_V3_ACL_SUPPORT
1038 bool "Enable ACLs for NFSDv3"
1041 config KERNEL_REISER_FS_POSIX_ACL
1042 bool "Enable POSIX ACLs for ReiserFS"
1043 select KERNEL_FS_POSIX_ACL
1044 default y if USE_FS_ACL_ATTR
1046 config KERNEL_XFS_POSIX_ACL
1047 bool "Enable POSIX ACLs for XFS"
1048 select KERNEL_FS_POSIX_ACL
1049 default y if USE_FS_ACL_ATTR
1051 config KERNEL_JFS_POSIX_ACL
1052 bool "Enable POSIX ACLs for JFS"
1053 select KERNEL_FS_POSIX_ACL
1054 default y if USE_FS_ACL_ATTR
1058 config KERNEL_DEVMEM
1059 bool "/dev/mem virtual device support"
1061 Say Y here if you want to support the /dev/mem device.
1062 The /dev/mem device is used to access areas of physical
1065 config KERNEL_DEVKMEM
1066 bool "/dev/kmem virtual device support"
1068 Say Y here if you want to support the /dev/kmem device. The
1069 /dev/kmem device is rarely used, but can be used for certain
1070 kind of kernel debugging operations.
1072 config KERNEL_SQUASHFS_FRAGMENT_CACHE_SIZE
1073 int "Number of squashfs fragments cached"
1074 default 2 if (SMALL_FLASH && !LOW_MEMORY_FOOTPRINT)
1077 config KERNEL_SQUASHFS_XATTR
1078 bool "Squashfs XATTR support"
1081 # compile optimiziation setting
1084 prompt "Compiler optimization level"
1085 default KERNEL_CC_OPTIMIZE_FOR_SIZE if SMALL_FLASH
1087 config KERNEL_CC_OPTIMIZE_FOR_PERFORMANCE
1088 bool "Optimize for performance"
1090 This is the default optimization level for the kernel, building
1091 with the "-O2" compiler flag for best performance and most
1092 helpful compile-time warnings.
1094 config KERNEL_CC_OPTIMIZE_FOR_SIZE
1095 bool "Optimize for size"
1097 Enabling this option will pass "-Os" instead of "-O2" to
1098 your compiler resulting in a smaller kernel.
1103 bool "Auditing support"
1105 config KERNEL_SECURITY
1106 bool "Enable different security models"
1108 config KERNEL_SECURITY_NETWORK
1109 bool "Socket and Networking Security Hooks"
1110 select KERNEL_SECURITY
1112 config KERNEL_SECURITY_SELINUX
1113 bool "NSA SELinux Support"
1114 select KERNEL_SECURITY_NETWORK
1117 config KERNEL_SECURITY_SELINUX_BOOTPARAM
1118 bool "NSA SELinux boot parameter"
1119 depends on KERNEL_SECURITY_SELINUX
1122 config KERNEL_SECURITY_SELINUX_DISABLE
1123 bool "NSA SELinux runtime disable"
1124 depends on KERNEL_SECURITY_SELINUX
1126 config KERNEL_SECURITY_SELINUX_DEVELOP
1127 bool "NSA SELinux Development Support"
1128 depends on KERNEL_SECURITY_SELINUX
1133 default "lockdown,yama,loadpin,safesetid,integrity,selinux"
1134 depends on KERNEL_SECURITY_SELINUX
1136 config KERNEL_EXT4_FS_SECURITY
1137 bool "Ext4 Security Labels"
1139 config KERNEL_F2FS_FS_SECURITY
1140 bool "F2FS Security Labels"
1142 config KERNEL_UBIFS_FS_SECURITY
1143 bool "UBIFS Security Labels"
1145 config KERNEL_JFFS2_FS_SECURITY
1146 bool "JFFS2 Security Labels"