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
49 default y if TARGET_pistachio
54 depends on (arm || aarch64)
56 config KERNEL_X86_VSYSCALL_EMULATION
57 bool "Enable vsyscall emulation"
61 This enables emulation of the legacy vsyscall page. Disabling
62 it is roughly equivalent to booting with vsyscall=none, except
63 that it will also disable the helpful warning if a program
64 tries to use a vsyscall. With this option set to N, offending
65 programs will just segfault, citing addresses of the form
68 This option is required by many programs built before 2013, and
69 care should be used even with newer programs if set to N.
71 Disabling this option saves about 7K of kernel size and
72 possibly 4K of additional runtime pagetable memory.
74 config KERNEL_PERF_EVENTS
75 bool "Compile the kernel with performance events and counters"
77 select KERNEL_ARM_PMU if (arm || aarch64)
79 config KERNEL_PROFILING
80 bool "Compile the kernel with profiling enabled"
82 select KERNEL_PERF_EVENTS
84 Enable the extended profiling support mechanisms used by profilers such
88 bool "Compile the kernel with undefined behaviour sanity checker"
90 This option enables undefined behaviour sanity checker
91 Compile-time instrumentation is used to detect various undefined
92 behaviours in runtime. Various types of checks may be enabled
93 via boot parameter ubsan_handle
94 (see: Documentation/dev-tools/ubsan.rst).
96 config KERNEL_UBSAN_SANITIZE_ALL
97 bool "Enable instrumentation for the entire kernel"
98 depends on KERNEL_UBSAN
101 This option activates instrumentation for the entire kernel.
102 If you don't enable this option, you have to explicitly specify
103 UBSAN_SANITIZE := y for the files/directories you want to check for UB.
104 Enabling this option will get kernel image size increased
107 config KERNEL_UBSAN_ALIGNMENT
108 bool "Enable checking of pointers alignment"
109 depends on KERNEL_UBSAN
111 This option enables detection of unaligned memory accesses.
112 Enabling this option on architectures that support unaligned
113 accesses may produce a lot of false positives.
115 config KERNEL_UBSAN_NULL
116 bool "Enable checking of null pointers"
117 depends on KERNEL_UBSAN
119 This option enables detection of memory accesses via a
123 bool "Compile the kernel with KASan: runtime memory debugger"
124 select KERNEL_SLUB_DEBUG
125 depends on (x86_64 || aarch64)
127 Enables kernel address sanitizer - runtime memory debugger,
128 designed to find out-of-bounds accesses and use-after-free bugs.
129 This is strictly a debugging feature and it requires a gcc version
130 of 4.9.2 or later. Detection of out of bounds accesses to stack or
131 global variables requires gcc 5.0 or later.
132 This feature consumes about 1/8 of available memory and brings about
133 ~x3 performance slowdown.
134 For better error detection enable CONFIG_STACKTRACE.
135 Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
136 (the resulting kernel does not boot).
138 config KERNEL_KASAN_EXTRA
139 bool "KAsan: extra checks"
140 depends on KERNEL_KASAN && KERNEL_DEBUG_KERNEL
142 This enables further checks in the kernel address sanitizer, for now
143 it only includes the address-use-after-scope check that can lead
144 to excessive kernel stack usage, frame size warnings and longer
146 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715 has more
150 prompt "Instrumentation type"
151 depends on KERNEL_KASAN
152 default KERNEL_KASAN_OUTLINE
154 config KERNEL_KASAN_OUTLINE
155 bool "Outline instrumentation"
157 Before every memory access compiler insert function call
158 __asan_load*/__asan_store*. These functions performs check
159 of shadow memory. This is slower than inline instrumentation,
160 however it doesn't bloat size of kernel's .text section so
163 config KERNEL_KASAN_INLINE
164 bool "Inline instrumentation"
166 Compiler directly inserts code checking shadow memory before
167 memory accesses. This is faster than outline (in some workloads
168 it gives about x2 boost over outline instrumentation), but
169 make kernel's .text size much bigger.
170 This requires a gcc version of 5.0 or later.
175 bool "Compile the kernel with code coverage for fuzzing"
176 select KERNEL_DEBUG_FS
178 KCOV exposes kernel code coverage information in a form suitable
179 for coverage-guided fuzzing (randomized testing).
181 If RANDOMIZE_BASE is enabled, PC values will not be stable across
182 different machines and across reboots. If you need stable PC values,
183 disable RANDOMIZE_BASE.
185 For more details, see Documentation/kcov.txt.
187 config KERNEL_KCOV_ENABLE_COMPARISONS
188 bool "Enable comparison operands collection by KCOV"
189 depends on KERNEL_KCOV
191 KCOV also exposes operands of every comparison in the instrumented
192 code along with operand sizes and PCs of the comparison instructions.
193 These operands can be used by fuzzing engines to improve the quality
196 config KERNEL_KCOV_INSTRUMENT_ALL
197 bool "Instrument all code by default"
198 depends on KERNEL_KCOV
199 default y if KERNEL_KCOV
201 If you are doing generic system call fuzzing (like e.g. syzkaller),
202 then you will want to instrument the whole kernel and you should
203 say y here. If you are doing more targeted fuzzing (like e.g.
204 filesystem fuzzing with AFL) then you will want to enable coverage
205 for more specific subsets of files, and should say n here.
207 config KERNEL_TASKSTATS
208 bool "Compile the kernel with task resource/io statistics and accounting"
211 Enable the collection and publishing of task/io statistics and
212 accounting. Enable this option to enable i/o monitoring in system
217 config KERNEL_TASK_DELAY_ACCT
220 config KERNEL_TASK_IO_ACCOUNTING
223 config KERNEL_TASK_XACCT
228 config KERNEL_KALLSYMS
229 bool "Compile the kernel with symbol table information"
230 default y if !SMALL_FLASH
232 This will give you more information in stack traces from kernel oopses.
235 bool "Compile the kernel with tracing support"
236 depends on !TARGET_uml
239 config KERNEL_FTRACE_SYSCALLS
240 bool "Trace system calls"
241 depends on KERNEL_FTRACE
244 config KERNEL_ENABLE_DEFAULT_TRACERS
245 bool "Trace process context switches and events"
246 depends on KERNEL_FTRACE
249 config KERNEL_FUNCTION_TRACER
250 bool "Function tracer"
251 depends on KERNEL_FTRACE
254 config KERNEL_FUNCTION_GRAPH_TRACER
255 bool "Function graph tracer"
256 depends on KERNEL_FUNCTION_TRACER
259 config KERNEL_DYNAMIC_FTRACE
260 bool "Enable/disable function tracing dynamically"
261 depends on KERNEL_FUNCTION_TRACER
264 config KERNEL_FUNCTION_PROFILER
265 bool "Function profiler"
266 depends on KERNEL_FUNCTION_TRACER
269 config KERNEL_DEBUG_KERNEL
273 config KERNEL_DEBUG_INFO
274 bool "Compile the kernel with debug information"
275 default y if !SMALL_FLASH
276 select KERNEL_DEBUG_KERNEL
278 This will compile your kernel and modules with debug information.
280 config KERNEL_DEBUG_LL_UART_NONE
285 config KERNEL_DEBUG_LL
289 select KERNEL_DEBUG_LL_UART_NONE
291 ARM low level debugging.
293 config KERNEL_DYNAMIC_DEBUG
294 bool "Compile the kernel with dynamic printk"
295 select KERNEL_DEBUG_FS
298 Compiles debug level messages into the kernel, which would not
299 otherwise be available at runtime. These messages can then be
300 enabled/disabled based on various levels of scope - per source file,
301 function, module, format string, and line number. This mechanism
302 implicitly compiles in all pr_debug() and dev_dbg() calls, which
303 enlarges the kernel text size by about 2%.
305 config KERNEL_EARLY_PRINTK
306 bool "Compile the kernel with early printk"
307 default y if TARGET_bcm53xx
310 select KERNEL_DEBUG_KERNEL
311 select KERNEL_DEBUG_LL if arm
313 Compile the kernel with early printk support. This is only useful for
314 debugging purposes to send messages over the serial console in early boot.
315 Enable this to debug early boot problems.
317 config KERNEL_KPROBES
318 bool "Compile the kernel with kprobes support"
321 select KERNEL_PERF_EVENTS
323 Compiles the kernel with KPROBES support, which allows you to trap
324 at almost any kernel address and execute a callback function.
325 register_kprobe() establishes a probepoint and specifies the
326 callback. Kprobes is useful for kernel debugging, non-intrusive
327 instrumentation and testing.
328 If in doubt, say "N".
330 config KERNEL_KPROBE_EVENT
332 default y if KERNEL_KPROBES
334 config KERNEL_KPROBE_EVENTS
336 default y if KERNEL_KPROBES
339 bool "Compile the kernel with asynchronous IO support"
340 default y if !SMALL_FLASH
342 config KERNEL_FHANDLE
343 bool "Compile the kernel with support for fhandle syscalls"
344 default y if !SMALL_FLASH
346 config KERNEL_FANOTIFY
347 bool "Compile the kernel with modern file notification support"
348 default y if !SMALL_FLASH
350 config KERNEL_BLK_DEV_BSG
351 bool "Compile the kernel with SCSI generic v4 support for any block device"
354 config KERNEL_TRANSPARENT_HUGEPAGE
358 prompt "Transparent Hugepage Support sysfs defaults"
359 depends on KERNEL_TRANSPARENT_HUGEPAGE
360 default KERNEL_TRANSPARENT_HUGEPAGE_ALWAYS
362 config KERNEL_TRANSPARENT_HUGEPAGE_ALWAYS
365 config KERNEL_TRANSPARENT_HUGEPAGE_MADVISE
369 config KERNEL_HUGETLBFS
372 config KERNEL_HUGETLB_PAGE
373 bool "Compile the kernel with HugeTLB support"
374 select KERNEL_TRANSPARENT_HUGEPAGE
375 select KERNEL_HUGETLBFS
378 config KERNEL_MAGIC_SYSRQ
379 bool "Compile the kernel with SysRq support"
382 config KERNEL_DEBUG_PINCTRL
383 bool "Compile the kernel with pinctrl debugging"
384 select KERNEL_DEBUG_KERNEL
386 config KERNEL_DEBUG_GPIO
387 bool "Compile the kernel with gpio debugging"
388 select KERNEL_DEBUG_KERNEL
390 config KERNEL_COREDUMP
393 config KERNEL_ELF_CORE
394 bool "Enable process core dump support"
395 select KERNEL_COREDUMP
396 default y if !SMALL_FLASH
398 config KERNEL_PROVE_LOCKING
399 bool "Enable kernel lock checking"
400 select KERNEL_DEBUG_KERNEL
403 config KERNEL_LOCKUP_DETECTOR
404 bool "Compile the kernel with detect Hard and Soft Lockups"
405 depends on KERNEL_DEBUG_KERNEL
407 Say Y here to enable the kernel to act as a watchdog to detect
408 hard and soft lockups.
410 Softlockups are bugs that cause the kernel to loop in kernel
411 mode for more than 20 seconds, without giving other tasks a
412 chance to run. The current stack trace is displayed upon
413 detection and the system will stay locked up.
415 Hardlockups are bugs that cause the CPU to loop in kernel mode
416 for more than 10 seconds, without letting other interrupts have a
417 chance to run. The current stack trace is displayed upon detection
418 and the system will stay locked up.
420 The overhead should be minimal. A periodic hrtimer runs to
421 generate interrupts and kick the watchdog task every 4 seconds.
422 An NMI is generated every 10 seconds or so to check for hardlockups.
424 The frequency of hrtimer and NMI events and the soft and hard lockup
425 thresholds can be controlled through the sysctl watchdog_thresh.
427 config KERNEL_DETECT_HUNG_TASK
428 bool "Compile the kernel with detect Hung Tasks"
429 depends on KERNEL_DEBUG_KERNEL
430 default KERNEL_LOCKUP_DETECTOR
432 Say Y here to enable the kernel to detect "hung tasks",
433 which are bugs that cause the task to be stuck in
434 uninterruptible "D" state indefinitely.
436 When a hung task is detected, the kernel will print the
437 current stack trace (which you should report), but the
438 task will stay in uninterruptible state. If lockdep is
439 enabled then all held locks will also be reported. This
440 feature has negligible overhead.
442 config KERNEL_WQ_WATCHDOG
443 bool "Compile the kernel with detect Workqueue Stalls"
444 depends on KERNEL_DEBUG_KERNEL
446 Say Y here to enable stall detection on workqueues. If a
447 worker pool doesn't make forward progress on a pending work
448 item for over a given amount of time, 30s by default, a
449 warning message is printed along with dump of workqueue
450 state. This can be configured through kernel parameter
451 "workqueue.watchdog_thresh" and its sysfs counterpart.
453 config KERNEL_DEBUG_ATOMIC_SLEEP
454 bool "Compile the kernel with sleep inside atomic section checking"
455 depends on KERNEL_DEBUG_KERNEL
457 If you say Y here, various routines which may sleep will become very
458 noisy if they are called inside atomic sections: when a spinlock is
459 held, inside an rcu read side critical section, inside preempt disabled
460 sections, inside an interrupt, etc...
462 config KERNEL_DEBUG_VM
463 bool "Compile the kernel with debug VM"
464 depends on KERNEL_DEBUG_KERNEL
466 Enable this to turn on extended checks in the virtual-memory system
467 that may impact performance.
471 config KERNEL_PRINTK_TIME
472 bool "Enable printk timestamps"
475 config KERNEL_SLUB_DEBUG
478 config KERNEL_SLUB_DEBUG_ON
481 config KERNEL_SLABINFO
482 select KERNEL_SLUB_DEBUG
483 select KERNEL_SLUB_DEBUG_ON
484 bool "Enable /proc slab debug info"
486 config KERNEL_PROC_PAGE_MONITOR
487 bool "Enable /proc page monitoring"
493 bool "Enable kexec support"
495 config KERNEL_PROC_VMCORE
498 config KERNEL_PROC_KCORE
501 config KERNEL_CRASH_DUMP
502 depends on i386 || x86_64 || arm || armeb
504 select KERNEL_PROC_VMCORE
505 select KERNEL_PROC_KCORE
506 bool "Enable support for kexec crashdump"
510 bool "Enable rfkill support"
511 default RFKILL_SUPPORT
514 bool "Enable sparse check during kernel build"
517 config KERNEL_DEVTMPFS
518 bool "Compile the kernel with device tmpfs enabled"
521 devtmpfs is a simple, kernel-managed /dev filesystem. The kernel creates
522 devices nodes for all registered devices to simplify boot, but leaves more
523 complex tasks to userspace (e.g. udev).
527 config KERNEL_DEVTMPFS_MOUNT
528 bool "Automatically mount devtmpfs after root filesystem is mounted"
534 bool "Enable kernel access key retention support"
537 config KERNEL_PERSISTENT_KEYRINGS
538 bool "Enable kernel persistent keyrings"
539 depends on KERNEL_KEYS
542 config KERNEL_BIG_KEYS
543 bool "Enable large payload keys on kernel keyrings"
544 depends on KERNEL_KEYS
547 config KERNEL_ENCRYPTED_KEYS
548 tristate "Enable keys with encrypted payloads on kernel keyrings"
549 depends on KERNEL_KEYS
553 # CGROUP support symbols
556 config KERNEL_CGROUPS
557 bool "Enable kernel cgroups"
558 default y if !SMALL_FLASH
562 config KERNEL_CGROUP_DEBUG
563 bool "Example debug cgroup subsystem"
566 This option enables a simple cgroup subsystem that
567 exports useful debugging information about the cgroups
570 config KERNEL_FREEZER
573 config KERNEL_CGROUP_FREEZER
574 bool "legacy Freezer cgroup subsystem"
576 select KERNEL_FREEZER
578 Provides a way to freeze and unfreeze all tasks in a
580 (legacy cgroup1-only controller, in cgroup2 freezer
581 is integrated in the Memory controller)
583 config KERNEL_CGROUP_DEVICE
584 bool "legacy Device controller for cgroups"
587 Provides a cgroup implementing whitelists for devices which
588 a process in the cgroup can mknod or open.
589 (legacy cgroup1-only controller)
591 config KERNEL_CGROUP_HUGETLB
592 bool "HugeTLB controller"
594 select KERNEL_HUGETLB_PAGE
596 config KERNEL_CGROUP_PIDS
597 bool "PIDs cgroup subsystem"
600 Provides enforcement of process number limits in the scope of a
603 config KERNEL_CGROUP_RDMA
604 bool "RDMA controller for cgroups"
607 config KERNEL_CGROUP_BPF
608 bool "Support for eBPF programs attached to cgroups"
611 config KERNEL_CPUSETS
612 bool "Cpuset support"
615 This option will let you create and manage CPUSETs which
616 allow dynamically partitioning a system into sets of CPUs and
617 Memory Nodes and assigning tasks to run only within those sets.
618 This is primarily useful on large SMP or NUMA systems.
620 config KERNEL_PROC_PID_CPUSET
621 bool "Include legacy /proc/<pid>/cpuset file"
623 depends on KERNEL_CPUSETS
625 config KERNEL_CGROUP_CPUACCT
626 bool "Simple CPU accounting cgroup subsystem"
629 Provides a simple Resource Controller for monitoring the
630 total CPU consumed by the tasks in a cgroup.
632 config KERNEL_RESOURCE_COUNTERS
633 bool "Resource counters"
636 This option enables controller independent resource accounting
637 infrastructure that works with cgroups.
639 config KERNEL_MM_OWNER
641 default y if KERNEL_MEMCG
644 bool "Memory Resource Controller for Control Groups"
646 select KERNEL_FREEZER
647 depends on KERNEL_RESOURCE_COUNTERS || !LINUX_3_18
649 Provides a memory resource controller that manages both anonymous
650 memory and page cache. (See Documentation/cgroups/memory.txt)
652 Note that setting this option increases fixed memory overhead
653 associated with each page of memory in the system. By this,
654 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
655 usage tracking struct at boot. Total amount of this is printed out
658 Only enable when you're ok with these tradeoffs and really
659 sure you need the memory resource controller. Even when you enable
660 this, you can set "cgroup_disable=memory" at your boot option to
661 disable memory resource controller and you can avoid overheads
662 (but lose benefits of memory resource controller).
664 This config option also selects MM_OWNER config option, which
665 could in turn add some fork/exit overhead.
667 config KERNEL_MEMCG_SWAP
668 bool "Memory Resource Controller Swap Extension"
670 depends on KERNEL_MEMCG
672 Add swap management feature to memory resource controller. When you
673 enable this, you can limit mem+swap usage per cgroup. In other words,
674 when you disable this, memory resource controller has no cares to
675 usage of swap...a process can exhaust all of the swap. This extension
676 is useful when you want to avoid exhaustion swap but this itself
677 adds more overheads and consumes memory for remembering information.
678 Especially if you use 32bit system or small memory system, please
679 be careful about enabling this. When memory resource controller
680 is disabled by boot option, this will be automatically disabled and
681 there will be no overhead from this. Even when you set this config=y,
682 if boot option "swapaccount=0" is set, swap will not be accounted.
683 Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
684 size is 4096bytes, 512k per 1Gbytes of swap.
686 config KERNEL_MEMCG_SWAP_ENABLED
687 bool "Memory Resource Controller Swap Extension enabled by default"
689 depends on KERNEL_MEMCG_SWAP
691 Memory Resource Controller Swap Extension comes with its price in
692 a bigger memory consumption. General purpose distribution kernels
693 which want to enable the feature but keep it disabled by default
694 and let the user enable it by swapaccount boot command line
695 parameter should have this option unselected.
697 Those who want to have the feature enabled by default should
698 select this option (if, for some reason, they need to disable it,
699 then swapaccount=0 does the trick).
702 config KERNEL_MEMCG_KMEM
703 bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
705 depends on KERNEL_MEMCG
707 The Kernel Memory extension for Memory Resource Controller can limit
708 the amount of memory used by kernel objects in the system. Those are
709 fundamentally different from the entities handled by the standard
710 Memory Controller, which are page-based, and can be swapped. Users of
711 the kmem extension can use it to guarantee that no group of processes
712 will ever exhaust kernel resources alone.
714 config KERNEL_CGROUP_PERF
715 bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
716 select KERNEL_PERF_EVENTS
719 This option extends the per-cpu mode to restrict monitoring to
720 threads which belong to the cgroup specified and run on the
723 menuconfig KERNEL_CGROUP_SCHED
724 bool "Group CPU scheduler"
727 This feature lets CPU scheduler recognize task groups and control CPU
728 bandwidth allocation to such task groups. It uses cgroups to group
731 if KERNEL_CGROUP_SCHED
733 config KERNEL_FAIR_GROUP_SCHED
734 bool "Group scheduling for SCHED_OTHER"
737 config KERNEL_CFS_BANDWIDTH
738 bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
740 depends on KERNEL_FAIR_GROUP_SCHED
742 This option allows users to define CPU bandwidth rates (limits) for
743 tasks running within the fair group scheduler. Groups with no limit
744 set are considered to be unconstrained and will run with no
746 See tip/Documentation/scheduler/sched-bwc.txt for more information.
748 config KERNEL_RT_GROUP_SCHED
749 bool "Group scheduling for SCHED_RR/FIFO"
752 This feature lets you explicitly allocate real CPU bandwidth
753 to task groups. If enabled, it will also make it impossible to
754 schedule realtime tasks for non-root users until you allocate
755 realtime bandwidth for them.
759 config KERNEL_BLK_CGROUP
760 bool "Block IO controller"
763 Generic block IO controller cgroup interface. This is the common
764 cgroup interface which should be used by various IO controlling
767 Currently, CFQ IO scheduler uses it to recognize task groups and
768 control disk bandwidth allocation (proportional time slice allocation)
769 to such task groups. It is also used by bio throttling logic in
770 block layer to implement upper limit in IO rates on a device.
772 This option only enables generic Block IO controller infrastructure.
773 One needs to also enable actual IO controlling logic/policy. For
774 enabling proportional weight division of disk bandwidth in CFQ, set
775 CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
776 CONFIG_BLK_DEV_THROTTLING=y.
780 config KERNEL_CFQ_GROUP_IOSCHED
781 bool "Proportional weight of disk bandwidth in CFQ"
783 config KERNEL_BLK_DEV_THROTTLING
784 bool "Enable throttling policy"
787 config KERNEL_BLK_DEV_THROTTLING_LOW
788 bool "Block throttling .low limit interface support (EXPERIMENTAL)"
789 depends on KERNEL_BLK_DEV_THROTTLING
792 config KERNEL_DEBUG_BLK_CGROUP
793 bool "Enable Block IO controller debugging"
795 depends on KERNEL_BLK_CGROUP
797 Enable some debugging help. Currently it exports additional stat
798 files in a cgroup which can be useful for debugging.
800 config KERNEL_NET_CLS_CGROUP
801 bool "legacy Control Group Classifier"
804 config KERNEL_CGROUP_NET_CLASSID
805 bool "legacy Network classid cgroup"
808 config KERNEL_CGROUP_NET_PRIO
809 bool "legacy Network priority cgroup"
815 # Namespace support symbols
818 config KERNEL_NAMESPACES
819 bool "Enable kernel namespaces"
820 default y if !SMALL_FLASH
828 In this namespace, tasks see different info provided
829 with the uname() system call.
835 In this namespace, tasks work with IPC ids which correspond to
836 different IPC objects in different namespaces.
838 config KERNEL_USER_NS
839 bool "User namespace (EXPERIMENTAL)"
842 This allows containers, i.e. vservers, to use user namespaces
843 to provide different user info for different servers.
846 bool "PID Namespaces"
849 Support process id namespaces. This allows having multiple
850 processes with the same pid as long as they are in different
851 pid namespaces. This is a building block of containers.
854 bool "Network namespace"
857 Allow user space to create what appear to be multiple instances
858 of the network stack.
862 config KERNEL_DEVPTS_MULTIPLE_INSTANCES
863 bool "Support multiple instances of devpts"
864 default y if !SMALL_FLASH
866 Enable support for multiple instances of devpts filesystem.
867 If you want to have isolated PTY namespaces (eg: in containers),
868 say Y here. Otherwise, say N. If enabled, each mount of devpts
869 filesystem with the '-o newinstance' option will create an
870 independent PTY namespace.
872 config KERNEL_POSIX_MQUEUE
873 bool "POSIX Message Queues"
874 default y if !SMALL_FLASH
876 POSIX variant of message queues is a part of IPC. In POSIX message
877 queues every message has a priority which decides about succession
878 of receiving it by a process. If you want to compile and run
879 programs written e.g. for Solaris with use of its POSIX message
880 queues (functions mq_*) say Y here.
882 POSIX message queues are visible as a filesystem called 'mqueue'
883 and can be mounted somewhere if you want to do filesystem
884 operations on message queues.
887 config KERNEL_SECCOMP_FILTER
889 default y if !SMALL_FLASH
891 config KERNEL_SECCOMP
892 bool "Enable seccomp support"
893 depends on !(TARGET_uml)
894 select KERNEL_SECCOMP_FILTER
895 default y if !SMALL_FLASH
897 Build kernel with support for seccomp.
903 config KERNEL_IP_MROUTE
904 bool "Enable IPv4 multicast routing"
907 Multicast routing requires a multicast routing daemon in
908 addition to kernel support.
919 config KERNEL_IPV6_MULTIPLE_TABLES
922 config KERNEL_IPV6_SUBTREES
925 config KERNEL_IPV6_MROUTE
926 bool "Enable IPv6 multicast routing"
929 Multicast routing requires a multicast routing daemon in
930 addition to kernel support.
932 config KERNEL_IPV6_PIMSM_V2
938 # NFS related symbols
941 bool "Compile the kernel with rootfs on NFS"
943 If you want to make your kernel boot off a NFS server as root
944 filesystem, select Y here.
948 config KERNEL_IP_PNP_DHCP
951 config KERNEL_IP_PNP_BOOTP
954 config KERNEL_IP_PNP_RARP
966 config KERNEL_ROOT_NFS
971 menu "Filesystem ACL and attr support options"
972 config USE_FS_ACL_ATTR
973 bool "Use filesystem ACL and attr support by default"
976 Make using ACLs (e.g. POSIX ACL, NFSv4 ACL) the default
977 for kernel and packages, except tmpfs, flash filesystems,
978 and old NFS. Also enable userspace extended attribute support
979 by default. (OpenWrt already has an expection it will be
980 present in the kernel).
982 config KERNEL_FS_POSIX_ACL
983 bool "Enable POSIX ACL support"
984 default y if USE_FS_ACL_ATTR
986 config KERNEL_BTRFS_FS_POSIX_ACL
987 bool "Enable POSIX ACL for BtrFS Filesystems"
988 select KERNEL_FS_POSIX_ACL
989 default y if USE_FS_ACL_ATTR
991 config KERNEL_EXT4_FS_POSIX_ACL
992 bool "Enable POSIX ACL for Ext4 Filesystems"
993 select KERNEL_FS_POSIX_ACL
994 default y if USE_FS_ACL_ATTR
996 config KERNEL_F2FS_FS_POSIX_ACL
997 bool "Enable POSIX ACL for F2FS Filesystems"
998 select KERNEL_FS_POSIX_ACL
1001 config KERNEL_JFFS2_FS_POSIX_ACL
1002 bool "Enable POSIX ACL for JFFS2 Filesystems"
1003 select KERNEL_FS_POSIX_ACL
1006 config KERNEL_TMPFS_POSIX_ACL
1007 bool "Enable POSIX ACL for TMPFS Filesystems"
1008 select KERNEL_FS_POSIX_ACL
1011 config KERNEL_CIFS_ACL
1012 bool "Enable CIFS ACLs"
1013 select KERNEL_FS_POSIX_ACL
1014 default y if USE_FS_ACL_ATTR
1016 config KERNEL_HFS_FS_POSIX_ACL
1017 bool "Enable POSIX ACL for HFS Filesystems"
1018 select KERNEL_FS_POSIX_ACL
1019 default y if USE_FS_ACL_ATTR
1021 config KERNEL_HFSPLUS_FS_POSIX_ACL
1022 bool "Enable POSIX ACL for HFS+ Filesystems"
1023 select KERNEL_FS_POSIX_ACL
1024 default y if USE_FS_ACL_ATTR
1026 config KERNEL_NFS_ACL_SUPPORT
1027 bool "Enable ACLs for NFS"
1028 default y if USE_FS_ACL_ATTR
1030 config KERNEL_NFS_V3_ACL_SUPPORT
1031 bool "Enable ACLs for NFSv3"
1034 config KERNEL_NFSD_V2_ACL_SUPPORT
1035 bool "Enable ACLs for NFSDv2"
1038 config KERNEL_NFSD_V3_ACL_SUPPORT
1039 bool "Enable ACLs for NFSDv3"
1042 config KERNEL_REISER_FS_POSIX_ACL
1043 bool "Enable POSIX ACLs for ReiserFS"
1044 select KERNEL_FS_POSIX_ACL
1045 default y if USE_FS_ACL_ATTR
1047 config KERNEL_XFS_POSIX_ACL
1048 bool "Enable POSIX ACLs for XFS"
1049 select KERNEL_FS_POSIX_ACL
1050 default y if USE_FS_ACL_ATTR
1052 config KERNEL_JFS_POSIX_ACL
1053 bool "Enable POSIX ACLs for JFS"
1054 select KERNEL_FS_POSIX_ACL
1055 default y if USE_FS_ACL_ATTR
1059 config KERNEL_DEVMEM
1060 bool "/dev/mem virtual device support"
1062 Say Y here if you want to support the /dev/mem device.
1063 The /dev/mem device is used to access areas of physical
1066 config KERNEL_DEVKMEM
1067 bool "/dev/kmem virtual device support"
1069 Say Y here if you want to support the /dev/kmem device. The
1070 /dev/kmem device is rarely used, but can be used for certain
1071 kind of kernel debugging operations.
1073 config KERNEL_SQUASHFS_FRAGMENT_CACHE_SIZE
1074 int "Number of squashfs fragments cached"
1075 default 2 if (SMALL_FLASH && !LOW_MEMORY_FOOTPRINT)
1078 config KERNEL_SQUASHFS_XATTR
1079 bool "Squashfs XATTR support"
1082 # compile optimiziation setting
1085 prompt "Compiler optimization level"
1086 default KERNEL_CC_OPTIMIZE_FOR_SIZE if SMALL_FLASH
1088 config KERNEL_CC_OPTIMIZE_FOR_PERFORMANCE
1089 bool "Optimize for performance"
1091 This is the default optimization level for the kernel, building
1092 with the "-O2" compiler flag for best performance and most
1093 helpful compile-time warnings.
1095 config KERNEL_CC_OPTIMIZE_FOR_SIZE
1096 bool "Optimize for size"
1098 Enabling this option will pass "-Os" instead of "-O2" to
1099 your compiler resulting in a smaller kernel.
1104 bool "Auditing support"
1106 config KERNEL_SECURITY
1107 bool "Enable different security models"
1109 config KERNEL_SECURITY_NETWORK
1110 bool "Socket and Networking Security Hooks"
1111 select KERNEL_SECURITY
1113 config KERNEL_SECURITY_SELINUX
1114 bool "NSA SELinux Support"
1115 select KERNEL_SECURITY_NETWORK
1118 config KERNEL_SECURITY_SELINUX_BOOTPARAM
1119 bool "NSA SELinux boot parameter"
1120 depends on KERNEL_SECURITY_SELINUX
1123 config KERNEL_SECURITY_SELINUX_DISABLE
1124 bool "NSA SELinux runtime disable"
1125 depends on KERNEL_SECURITY_SELINUX
1127 config KERNEL_SECURITY_SELINUX_DEVELOP
1128 bool "NSA SELinux Development Support"
1129 depends on KERNEL_SECURITY_SELINUX
1134 default "lockdown,yama,loadpin,safesetid,integrity,selinux"
1135 depends on KERNEL_SECURITY_SELINUX
1137 config KERNEL_EXT4_FS_SECURITY
1138 bool "Ext4 Security Labels"
1140 config KERNEL_F2FS_FS_SECURITY
1141 bool "F2FS Security Labels"
1143 config KERNEL_UBIFS_FS_SECURITY
1144 bool "UBIFS Security Labels"
1146 config KERNEL_JFFS2_FS_SECURITY
1147 bool "JFFS2 Security Labels"