Config-kernel.in 46 KB

12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485868788899091929394959697989910010110210310410510610710810911011111211311411511611711811912012112212312412512612712812913013113213313413513613713813914014114214314414514614714814915015115215315415515615715815916016116216316416516616716816917017117217317417517617717817918018118218318418518618718818919019119219319419519619719819920020120220320420520620720820921021121221321421521621721821922022122222322422522622722822923023123223323423523623723823924024124224324424524624724824925025125225325425525625725825926026126226326426526626726826927027127227327427527627727827928028128228328428528628728828929029129229329429529629729829930030130230330430530630730830931031131231331431531631731831932032132232332432532632732832933033133233333433533633733833934034134234334434534634734834935035135235335435535635735835936036136236336436536636736836937037137237337437537637737837938038138238338438538638738838939039139239339439539639739839940040140240340440540640740840941041141241341441541641741841942042142242342442542642742842943043143243343443543643743843944044144244344444544644744844945045145245345445545645745845946046146246346446546646746846947047147247347447547647747847948048148248348448548648748848949049149249349449549649749849950050150250350450550650750850951051151251351451551651751851952052152252352452552652752852953053153253353453553653753853954054154254354454554654754854955055155255355455555655755855956056156256356456556656756856957057157257357457557657757857958058158258358458558658758858959059159259359459559659759859960060160260360460560660760860961061161261361461561661761861962062162262362462562662762862963063163263363463563663763863964064164264364464564664764864965065165265365465565665765865966066166266366466566666766866967067167267367467567667767867968068168268368468568668768868969069169269369469569669769869970070170270370470570670770870971071171271371471571671771871972072172272372472572672772872973073173273373473573673773873974074174274374474574674774874975075175275375475575675775875976076176276376476576676776876977077177277377477577677777877978078178278378478578678778878979079179279379479579679779879980080180280380480580680780880981081181281381481581681781881982082182282382482582682782882983083183283383483583683783883984084184284384484584684784884985085185285385485585685785885986086186286386486586686786886987087187287387487587687787887988088188288388488588688788888989089189289389489589689789889990090190290390490590690790890991091191291391491591691791891992092192292392492592692792892993093193293393493593693793893994094194294394494594694794894995095195295395495595695795895996096196296396496596696796896997097197297397497597697797897998098198298398498598698798898999099199299399499599699799899910001001100210031004100510061007100810091010101110121013101410151016101710181019102010211022102310241025102610271028102910301031103210331034103510361037103810391040104110421043104410451046104710481049105010511052105310541055105610571058105910601061106210631064106510661067106810691070107110721073107410751076107710781079108010811082108310841085108610871088108910901091109210931094109510961097109810991100110111021103110411051106110711081109111011111112111311141115111611171118111911201121112211231124112511261127112811291130113111321133113411351136113711381139114011411142114311441145114611471148114911501151115211531154115511561157115811591160116111621163116411651166116711681169117011711172117311741175117611771178117911801181118211831184118511861187118811891190119111921193119411951196119711981199120012011202120312041205120612071208120912101211121212131214121512161217121812191220122112221223122412251226122712281229123012311232123312341235123612371238123912401241124212431244124512461247124812491250125112521253125412551256125712581259126012611262126312641265126612671268126912701271127212731274127512761277127812791280128112821283128412851286128712881289129012911292129312941295129612971298129913001301130213031304130513061307130813091310131113121313131413151316131713181319132013211322132313241325132613271328132913301331133213331334133513361337133813391340134113421343134413451346134713481349135013511352135313541355135613571358135913601361136213631364136513661367136813691370137113721373137413751376137713781379138013811382138313841385138613871388138913901391139213931394139513961397139813991400140114021403140414051406140714081409141014111412141314141415141614171418141914201421142214231424142514261427142814291430143114321433143414351436143714381439144014411442144314441445144614471448144914501451145214531454145514561457145814591460146114621463146414651466146714681469147014711472147314741475147614771478147914801481148214831484148514861487148814891490149114921493149414951496149714981499150015011502150315041505150615071508150915101511151215131514151515161517151815191520152115221523152415251526152715281529153015311532153315341535153615371538153915401541154215431544154515461547154815491550155115521553155415551556
  1. # SPDX-License-Identifier: GPL-2.0-only
  2. #
  3. # Copyright (C) 2006-2014 OpenWrt.org
  4. config KERNEL_BUILD_USER
  5. string "Custom Kernel Build User Name"
  6. default "builder" if BUILDBOT
  7. default ""
  8. help
  9. Sets the Kernel build user string, which for example will be returned
  10. by 'uname -a' on running systems.
  11. If not set, uses system user at build time.
  12. config KERNEL_BUILD_DOMAIN
  13. string "Custom Kernel Build Domain Name"
  14. default "buildhost" if BUILDBOT
  15. default ""
  16. help
  17. Sets the Kernel build domain string, which for example will be
  18. returned by 'uname -a' on running systems.
  19. If not set, uses system hostname at build time.
  20. config KERNEL_PRINTK
  21. bool "Enable support for printk"
  22. default y
  23. config KERNEL_SWAP
  24. bool "Support for paging of anonymous memory (swap)"
  25. default y if !SMALL_FLASH
  26. config KERNEL_PROC_STRIPPED
  27. bool "Strip non-essential /proc functionality to reduce code size"
  28. default y if SMALL_FLASH
  29. config KERNEL_DEBUG_FS
  30. bool "Compile the kernel with debug filesystem enabled"
  31. default y
  32. help
  33. debugfs is a virtual file system that kernel developers use to put
  34. debugging files into. Enable this option to be able to read and
  35. write to these files. Many common debugging facilities, such as
  36. ftrace, require the existence of debugfs.
  37. config KERNEL_MIPS_FP_SUPPORT
  38. bool
  39. default y if TARGET_pistachio
  40. config KERNEL_ARM_PMU
  41. bool
  42. default y if TARGET_armsr_armv8
  43. depends on (arm || aarch64)
  44. config KERNEL_ARM_PMUV3
  45. bool
  46. default y if TARGET_armsr_armv8
  47. depends on (arm_v7 || aarch64) && LINUX_6_6
  48. config KERNEL_RISCV_PMU
  49. bool
  50. select KERNEL_RISCV_PMU_SBI
  51. depends on riscv64
  52. config KERNEL_RISCV_PMU_SBI
  53. bool
  54. depends on riscv64
  55. config KERNEL_X86_VSYSCALL_EMULATION
  56. bool "Enable vsyscall emulation"
  57. depends on x86_64
  58. help
  59. This enables emulation of the legacy vsyscall page. Disabling
  60. it is roughly equivalent to booting with vsyscall=none, except
  61. that it will also disable the helpful warning if a program
  62. tries to use a vsyscall. With this option set to N, offending
  63. programs will just segfault, citing addresses of the form
  64. 0xffffffffff600?00.
  65. This option is required by many programs built before 2013, and
  66. care should be used even with newer programs if set to N.
  67. Disabling this option saves about 7K of kernel size and
  68. possibly 4K of additional runtime pagetable memory.
  69. config KERNEL_PERF_EVENTS
  70. bool "Compile the kernel with performance events and counters"
  71. select KERNEL_ARM_PMU if (arm || aarch64)
  72. select KERNEL_ARM_PMUV3 if (arm_v7 || aarch64) && LINUX_6_6
  73. select KERNEL_RISCV_PMU if riscv64
  74. config KERNEL_PROFILING
  75. bool "Compile the kernel with profiling enabled"
  76. select KERNEL_PERF_EVENTS
  77. help
  78. Enable the extended profiling support mechanisms used by profilers such
  79. as OProfile.
  80. config KERNEL_RPI_AXIPERF
  81. bool "Compile the kernel with RaspberryPi AXI Performance monitors"
  82. default y
  83. depends on KERNEL_PERF_EVENTS && TARGET_bcm27xx
  84. config KERNEL_UBSAN
  85. bool "Compile the kernel with undefined behaviour sanity checker"
  86. help
  87. This option enables undefined behaviour sanity checker
  88. Compile-time instrumentation is used to detect various undefined
  89. behaviours in runtime. Various types of checks may be enabled
  90. via boot parameter ubsan_handle
  91. (see: Documentation/dev-tools/ubsan.rst).
  92. config KERNEL_UBSAN_SANITIZE_ALL
  93. bool "Enable instrumentation for the entire kernel"
  94. depends on KERNEL_UBSAN
  95. default y
  96. help
  97. This option activates instrumentation for the entire kernel.
  98. If you don't enable this option, you have to explicitly specify
  99. UBSAN_SANITIZE := y for the files/directories you want to check for UB.
  100. Enabling this option will get kernel image size increased
  101. significantly.
  102. config KERNEL_UBSAN_ALIGNMENT
  103. bool "Enable checking of pointers alignment"
  104. depends on KERNEL_UBSAN
  105. help
  106. This option enables detection of unaligned memory accesses.
  107. Enabling this option on architectures that support unaligned
  108. accesses may produce a lot of false positives.
  109. config KERNEL_UBSAN_BOUNDS
  110. bool "Perform array index bounds checking"
  111. depends on KERNEL_UBSAN
  112. help
  113. This option enables detection of directly indexed out of bounds array
  114. accesses, where the array size is known at compile time. Note that
  115. this does not protect array overflows via bad calls to the
  116. {str,mem}*cpy() family of functions (that is addressed by
  117. FORTIFY_SOURCE).
  118. config KERNEL_UBSAN_NULL
  119. bool "Enable checking of null pointers"
  120. depends on KERNEL_UBSAN
  121. help
  122. This option enables detection of memory accesses via a
  123. null pointer.
  124. config KERNEL_UBSAN_TRAP
  125. bool "On Sanitizer warnings, abort the running kernel code"
  126. depends on KERNEL_UBSAN
  127. help
  128. Building kernels with Sanitizer features enabled tends to grow the
  129. kernel size by around 5%, due to adding all the debugging text on
  130. failure paths. To avoid this, Sanitizer instrumentation can just
  131. issue a trap. This reduces the kernel size overhead but turns all
  132. warnings (including potentially harmless conditions) into full
  133. exceptions that abort the running kernel code (regardless of context,
  134. locks held, etc), which may destabilize the system. For some system
  135. builders this is an acceptable trade-off.
  136. config KERNEL_KASAN
  137. bool "Compile the kernel with KASan: runtime memory debugger"
  138. select KERNEL_SLUB_DEBUG
  139. depends on (x86_64 || aarch64 || arm || powerpc || riscv64)
  140. help
  141. Enables kernel address sanitizer - runtime memory debugger,
  142. designed to find out-of-bounds accesses and use-after-free bugs.
  143. This is strictly a debugging feature and it requires a gcc version
  144. of 4.9.2 or later. Detection of out of bounds accesses to stack or
  145. global variables requires gcc 5.0 or later.
  146. This feature consumes about 1/8 of available memory and brings about
  147. ~x3 performance slowdown.
  148. For better error detection enable CONFIG_STACKTRACE.
  149. Currently CONFIG_KASAN doesn't work with CONFIG_DEBUG_SLAB
  150. (the resulting kernel does not boot).
  151. config KERNEL_KASAN_VMALLOC
  152. bool "Back mappings in vmalloc space with real shadow memory"
  153. depends on KERNEL_KASAN
  154. help
  155. By default, the shadow region for vmalloc space is the read-only
  156. zero page. This means that KASAN cannot detect errors involving
  157. vmalloc space.
  158. Enabling this option will hook in to vmap/vmalloc and back those
  159. mappings with real shadow memory allocated on demand. This allows
  160. for KASAN to detect more sorts of errors (and to support vmapped
  161. stacks), but at the cost of higher memory usage.
  162. This option depends on HAVE_ARCH_KASAN_VMALLOC, but we can't
  163. depend on that in here, so it is possible that enabling this
  164. will have no effect.
  165. if KERNEL_KASAN
  166. choice
  167. prompt "KASAN mode"
  168. depends on KERNEL_KASAN
  169. default KERNEL_KASAN_GENERIC
  170. help
  171. KASAN has three modes:
  172. 1. Generic KASAN (supported by many architectures, enabled with
  173. CONFIG_KASAN_GENERIC, similar to userspace ASan),
  174. 2. Software Tag-Based KASAN (arm64 only, based on software memory
  175. tagging, enabled with CONFIG_KASAN_SW_TAGS, similar to userspace
  176. HWASan), and
  177. 3. Hardware Tag-Based KASAN (arm64 only, based on hardware memory
  178. tagging, enabled with CONFIG_KASAN_HW_TAGS).
  179. config KERNEL_KASAN_GENERIC
  180. bool "Generic KASAN"
  181. select KERNEL_SLUB_DEBUG
  182. help
  183. Enables Generic KASAN.
  184. Consumes about 1/8th of available memory at kernel start and adds an
  185. overhead of ~50% for dynamic allocations.
  186. The performance slowdown is ~x3.
  187. config KERNEL_KASAN_SW_TAGS
  188. bool "Software Tag-Based KASAN"
  189. depends on aarch64
  190. select KERNEL_SLUB_DEBUG
  191. help
  192. Enables Software Tag-Based KASAN.
  193. Supported only on arm64 CPUs and relies on Top Byte Ignore.
  194. Consumes about 1/16th of available memory at kernel start and
  195. add an overhead of ~20% for dynamic allocations.
  196. May potentially introduce problems related to pointer casting and
  197. comparison, as it embeds a tag into the top byte of each pointer.
  198. config KERNEL_KASAN_HW_TAGS
  199. bool "Hardware Tag-Based KASAN"
  200. depends on aarch64
  201. select KERNEL_SLUB_DEBUG
  202. select KERNEL_ARM64_MTE
  203. help
  204. Enables Hardware Tag-Based KASAN.
  205. Supported only on arm64 CPUs starting from ARMv8.5 and relies on
  206. Memory Tagging Extension and Top Byte Ignore.
  207. Consumes about 1/32nd of available memory.
  208. May potentially introduce problems related to pointer casting and
  209. comparison, as it embeds a tag into the top byte of each pointer.
  210. endchoice
  211. config KERNEL_ARM64_MTE
  212. def_bool n
  213. endif
  214. choice
  215. prompt "Instrumentation type"
  216. depends on KERNEL_KASAN
  217. depends on !KERNEL_KASAN_HW_TAGS
  218. default KERNEL_KASAN_OUTLINE
  219. config KERNEL_KASAN_OUTLINE
  220. bool "Outline instrumentation"
  221. help
  222. Before every memory access compiler insert function call
  223. __asan_load*/__asan_store*. These functions performs check
  224. of shadow memory. This is slower than inline instrumentation,
  225. however it doesn't bloat size of kernel's .text section so
  226. much as inline does.
  227. config KERNEL_KASAN_INLINE
  228. bool "Inline instrumentation"
  229. help
  230. Compiler directly inserts code checking shadow memory before
  231. memory accesses. This is faster than outline (in some workloads
  232. it gives about x2 boost over outline instrumentation), but
  233. make kernel's .text size much bigger.
  234. This requires a gcc version of 5.0 or later.
  235. endchoice
  236. config KERNEL_KCOV
  237. bool "Compile the kernel with code coverage for fuzzing"
  238. select KERNEL_DEBUG_FS
  239. help
  240. KCOV exposes kernel code coverage information in a form suitable
  241. for coverage-guided fuzzing (randomized testing).
  242. If RANDOMIZE_BASE is enabled, PC values will not be stable across
  243. different machines and across reboots. If you need stable PC values,
  244. disable RANDOMIZE_BASE.
  245. For more details, see Documentation/kcov.txt.
  246. config KERNEL_KCOV_ENABLE_COMPARISONS
  247. bool "Enable comparison operands collection by KCOV"
  248. depends on KERNEL_KCOV
  249. help
  250. KCOV also exposes operands of every comparison in the instrumented
  251. code along with operand sizes and PCs of the comparison instructions.
  252. These operands can be used by fuzzing engines to improve the quality
  253. of fuzzing coverage.
  254. config KERNEL_KCOV_INSTRUMENT_ALL
  255. bool "Instrument all code by default"
  256. depends on KERNEL_KCOV
  257. default y if KERNEL_KCOV
  258. help
  259. If you are doing generic system call fuzzing (like e.g. syzkaller),
  260. then you will want to instrument the whole kernel and you should
  261. say y here. If you are doing more targeted fuzzing (like e.g.
  262. filesystem fuzzing with AFL) then you will want to enable coverage
  263. for more specific subsets of files, and should say n here.
  264. config KERNEL_TASKSTATS
  265. bool "Compile the kernel with task resource/io statistics and accounting"
  266. help
  267. Enable the collection and publishing of task/io statistics and
  268. accounting. Enable this option to enable i/o monitoring in system
  269. monitors.
  270. if KERNEL_TASKSTATS
  271. config KERNEL_TASK_DELAY_ACCT
  272. def_bool y
  273. config KERNEL_TASK_IO_ACCOUNTING
  274. def_bool y
  275. config KERNEL_TASK_XACCT
  276. def_bool y
  277. endif
  278. config KERNEL_PSI
  279. bool "Compile the kernel with pressure stall information tracking"
  280. help
  281. Collect metrics that indicate how overcommitted the CPU, memory,
  282. and IO capacity are in the system.
  283. If you say Y here, the kernel will create /proc/pressure/ with the
  284. pressure statistics files cpu, memory, and io. These will indicate
  285. the share of walltime in which some or all tasks in the system are
  286. delayed due to contention of the respective resource.
  287. In kernels with cgroup support, cgroups (cgroup2 only) will
  288. have cpu.pressure, memory.pressure, and io.pressure files,
  289. which aggregate pressure stalls for the grouped tasks only.
  290. For more details see Documentation/accounting/psi.rst.
  291. Say N if unsure.
  292. config KERNEL_KALLSYMS
  293. bool "Compile the kernel with symbol table information"
  294. default y if !SMALL_FLASH
  295. help
  296. This will give you more information in stack traces from kernel oopses.
  297. config KERNEL_FTRACE
  298. bool "Compile the kernel with tracing support"
  299. depends on !TARGET_uml
  300. config KERNEL_FTRACE_SYSCALLS
  301. bool "Trace system calls"
  302. depends on KERNEL_FTRACE
  303. config KERNEL_ENABLE_DEFAULT_TRACERS
  304. bool "Trace process context switches and events"
  305. depends on KERNEL_FTRACE
  306. config KERNEL_FUNCTION_TRACER
  307. bool "Function tracer"
  308. depends on KERNEL_FTRACE
  309. config KERNEL_FUNCTION_GRAPH_TRACER
  310. bool "Function graph tracer"
  311. depends on KERNEL_FUNCTION_TRACER
  312. config KERNEL_DYNAMIC_FTRACE
  313. bool "Enable/disable function tracing dynamically"
  314. depends on KERNEL_FUNCTION_TRACER
  315. config KERNEL_FUNCTION_PROFILER
  316. bool "Function profiler"
  317. depends on KERNEL_FUNCTION_TRACER
  318. config KERNEL_IRQSOFF_TRACER
  319. bool "Interrupts-off Latency Tracer"
  320. depends on KERNEL_FTRACE
  321. help
  322. This option measures the time spent in irqs-off critical
  323. sections, with microsecond accuracy.
  324. The default measurement method is a maximum search, which is
  325. disabled by default and can be runtime (re-)started
  326. via:
  327. echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
  328. (Note that kernel size and overhead increase with this option
  329. enabled. This option and the preempt-off timing option can be
  330. used together or separately.)
  331. config KERNEL_PREEMPT_TRACER
  332. bool "Preemption-off Latency Tracer"
  333. depends on KERNEL_FTRACE
  334. help
  335. This option measures the time spent in preemption-off critical
  336. sections, with microsecond accuracy.
  337. The default measurement method is a maximum search, which is
  338. disabled by default and can be runtime (re-)started
  339. via:
  340. echo 0 > /sys/kernel/debug/tracing/tracing_max_latency
  341. (Note that kernel size and overhead increase with this option
  342. enabled. This option and the irqs-off timing option can be
  343. used together or separately.)
  344. config KERNEL_HIST_TRIGGERS
  345. bool "Histogram triggers"
  346. depends on KERNEL_FTRACE
  347. help
  348. Hist triggers allow one or more arbitrary trace event fields to be
  349. aggregated into hash tables and dumped to stdout by reading a
  350. debugfs/tracefs file. They're useful for gathering quick and dirty
  351. (though precise) summaries of event activity as an initial guide for
  352. further investigation using more advanced tools.
  353. Inter-event tracing of quantities such as latencies is also
  354. supported using hist triggers under this option.
  355. config KERNEL_DEBUG_KERNEL
  356. bool
  357. config KERNEL_DEBUG_INFO
  358. bool "Compile the kernel with debug information"
  359. default y if !SMALL_FLASH
  360. select KERNEL_DEBUG_KERNEL
  361. help
  362. This will compile your kernel and modules with debug information.
  363. config KERNEL_DEBUG_INFO_BTF
  364. bool "Enable additional BTF type information"
  365. depends on !HOST_OS_MACOS
  366. depends on KERNEL_DEBUG_INFO && !KERNEL_DEBUG_INFO_REDUCED
  367. select DWARVES
  368. help
  369. Generate BPF Type Format (BTF) information from DWARF debug info.
  370. Turning this on expects presence of pahole tool, which will convert
  371. DWARF type info into equivalent deduplicated BTF type info.
  372. Required to run BPF CO-RE applications.
  373. config KERNEL_DEBUG_INFO_BTF_MODULES
  374. def_bool y
  375. depends on KERNEL_DEBUG_INFO_BTF
  376. config KERNEL_MODULE_ALLOW_BTF_MISMATCH
  377. bool "Allow loading modules with non-matching BTF type info"
  378. depends on KERNEL_DEBUG_INFO_BTF_MODULES
  379. help
  380. For modules whose split BTF does not match vmlinux, load without
  381. BTF rather than refusing to load. The default behavior with
  382. module BTF enabled is to reject modules with such mismatches;
  383. this option will still load module BTF where possible but ignore
  384. it when a mismatch is found.
  385. config KERNEL_DEBUG_INFO_REDUCED
  386. bool "Reduce debugging information"
  387. default y
  388. depends on KERNEL_DEBUG_INFO
  389. help
  390. If you say Y here gcc is instructed to generate less debugging
  391. information for structure types. This means that tools that
  392. need full debugging information (like kgdb or systemtap) won't
  393. be happy. But if you merely need debugging information to
  394. resolve line numbers there is no loss. Advantage is that
  395. build directory object sizes shrink dramatically over a full
  396. DEBUG_INFO build and compile times are reduced too.
  397. Only works with newer gcc versions.
  398. config KERNEL_FRAME_WARN
  399. int
  400. range 0 8192
  401. default 1280 if KERNEL_KASAN && !ARCH_64BIT
  402. default 1024 if !ARCH_64BIT
  403. default 2048 if ARCH_64BIT
  404. help
  405. Tell the compiler to warn at build time for stack frames larger than this.
  406. Setting this too low will cause a lot of warnings.
  407. Setting it to 0 disables the warning.
  408. # KERNEL_DEBUG_LL symbols must have the default value set as otherwise
  409. # KConfig wont evaluate them unless KERNEL_EARLY_PRINTK is selected
  410. # which means that buildroot wont override the DEBUG_LL symbols in target
  411. # kernel configurations and lead to devices that dont have working console
  412. config KERNEL_DEBUG_LL_UART_NONE
  413. bool
  414. default n
  415. depends on arm
  416. config KERNEL_DEBUG_LL
  417. bool
  418. default n
  419. depends on arm
  420. select KERNEL_DEBUG_LL_UART_NONE
  421. help
  422. ARM low level debugging.
  423. config KERNEL_DEBUG_VIRTUAL
  424. bool "Compile the kernel with VM translations debugging"
  425. select KERNEL_DEBUG_KERNEL
  426. help
  427. Enable checks sanity checks to catch invalid uses of
  428. virt_to_phys()/phys_to_virt() against the non-linear address space.
  429. config KERNEL_DYNAMIC_DEBUG
  430. bool "Compile the kernel with dynamic printk"
  431. select KERNEL_DEBUG_FS
  432. help
  433. Compiles debug level messages into the kernel, which would not
  434. otherwise be available at runtime. These messages can then be
  435. enabled/disabled based on various levels of scope - per source file,
  436. function, module, format string, and line number. This mechanism
  437. implicitly compiles in all pr_debug() and dev_dbg() calls, which
  438. enlarges the kernel text size by about 2%.
  439. config KERNEL_EARLY_PRINTK
  440. bool "Compile the kernel with early printk"
  441. default y if TARGET_bcm53xx
  442. depends on arm
  443. select KERNEL_DEBUG_KERNEL
  444. select KERNEL_DEBUG_LL if arm
  445. help
  446. Compile the kernel with early printk support. This is only useful for
  447. debugging purposes to send messages over the serial console in early boot.
  448. Enable this to debug early boot problems.
  449. config KERNEL_KPROBES
  450. bool "Compile the kernel with kprobes support"
  451. select KERNEL_FTRACE
  452. select KERNEL_PERF_EVENTS
  453. help
  454. Compiles the kernel with KPROBES support, which allows you to trap
  455. at almost any kernel address and execute a callback function.
  456. register_kprobe() establishes a probepoint and specifies the
  457. callback. Kprobes is useful for kernel debugging, non-intrusive
  458. instrumentation and testing.
  459. If in doubt, say "N".
  460. config KERNEL_KPROBE_EVENTS
  461. bool
  462. default y if KERNEL_KPROBES
  463. config KERNEL_BPF_EVENTS
  464. bool "Compile the kernel with BPF event support"
  465. select KERNEL_KPROBES
  466. help
  467. Allows to attach BPF programs to kprobe, uprobe and tracepoint events.
  468. This is required to use BPF maps of type BPF_MAP_TYPE_PERF_EVENT_ARRAY
  469. for sending data from BPF programs to user-space for post-processing
  470. or logging.
  471. config KERNEL_PROBE_EVENTS_BTF_ARGS
  472. bool "Support BTF function arguments for probe events"
  473. depends on KERNEL_DEBUG_INFO_BTF && KERNEL_KPROBE_EVENTS
  474. config KERNEL_BPF_KPROBE_OVERRIDE
  475. bool
  476. depends on KERNEL_KPROBES
  477. default n
  478. config KERNEL_AIO
  479. bool "Compile the kernel with asynchronous IO support"
  480. default y if !SMALL_FLASH
  481. config KERNEL_IO_URING
  482. bool "Compile the kernel with io_uring support"
  483. depends on !SMALL_FLASH
  484. default y if (x86_64 || aarch64)
  485. config KERNEL_FHANDLE
  486. bool "Compile the kernel with support for fhandle syscalls"
  487. default y if !SMALL_FLASH
  488. config KERNEL_FANOTIFY
  489. bool "Compile the kernel with modern file notification support"
  490. default y if !SMALL_FLASH
  491. config KERNEL_BLK_DEV_BSG
  492. bool "Compile the kernel with SCSI generic v4 support for any block device"
  493. config KERNEL_TRANSPARENT_HUGEPAGE
  494. bool
  495. choice
  496. prompt "Transparent Hugepage Support sysfs defaults"
  497. depends on KERNEL_TRANSPARENT_HUGEPAGE
  498. default KERNEL_TRANSPARENT_HUGEPAGE_ALWAYS
  499. config KERNEL_TRANSPARENT_HUGEPAGE_ALWAYS
  500. bool "always"
  501. config KERNEL_TRANSPARENT_HUGEPAGE_MADVISE
  502. bool "madvise"
  503. config KERNEL_TRANSPARENT_HUGEPAGE_NEVER
  504. bool "never"
  505. depends on !LINUX_6_6
  506. endchoice
  507. config KERNEL_ARM64_CONTPTE
  508. bool "Compile the kernel with Contiguous PTE mappings for user memory"
  509. depends on KERNEL_ARM64
  510. depends on KERNEL_TRANSPARENT_HUGEPAGE
  511. depends on !LINUX_6_6
  512. default y
  513. config KERNEL_HUGETLBFS
  514. bool
  515. config KERNEL_HUGETLB_PAGE
  516. bool "Compile the kernel with HugeTLB support"
  517. select KERNEL_TRANSPARENT_HUGEPAGE
  518. select KERNEL_HUGETLBFS
  519. config KERNEL_MAGIC_SYSRQ
  520. bool "Compile the kernel with SysRq support"
  521. default y
  522. config KERNEL_DEBUG_PINCTRL
  523. bool "Compile the kernel with pinctrl debugging"
  524. select KERNEL_DEBUG_KERNEL
  525. config KERNEL_DEBUG_GPIO
  526. bool "Compile the kernel with gpio debugging"
  527. select KERNEL_DEBUG_KERNEL
  528. config KERNEL_COREDUMP
  529. bool
  530. config KERNEL_ELF_CORE
  531. bool "Enable process core dump support"
  532. select KERNEL_COREDUMP
  533. default y if !SMALL_FLASH
  534. config KERNEL_PROVE_LOCKING
  535. bool "Enable kernel lock checking"
  536. select KERNEL_DEBUG_KERNEL
  537. config KERNEL_SOFTLOCKUP_DETECTOR
  538. bool "Compile the kernel with detect Soft Lockups"
  539. depends on KERNEL_DEBUG_KERNEL
  540. help
  541. Say Y here to enable the kernel to act as a watchdog to detect
  542. soft lockups.
  543. Softlockups are bugs that cause the kernel to loop in kernel
  544. mode for more than 20 seconds, without giving other tasks a
  545. chance to run. The current stack trace is displayed upon
  546. detection and the system will stay locked up.
  547. config KERNEL_HARDLOCKUP_DETECTOR
  548. bool "Compile the kernel with detect Hard Lockups"
  549. depends on KERNEL_DEBUG_KERNEL
  550. help
  551. Say Y here to enable the kernel to act as a watchdog to detect
  552. hard lockups.
  553. Hardlockups are bugs that cause the CPU to loop in kernel mode
  554. for more than 10 seconds, without letting other interrupts have a
  555. chance to run. The current stack trace is displayed upon detection
  556. and the system will stay locked up.
  557. config KERNEL_DETECT_HUNG_TASK
  558. bool "Compile the kernel with detect Hung Tasks"
  559. depends on KERNEL_DEBUG_KERNEL
  560. default KERNEL_SOFTLOCKUP_DETECTOR
  561. help
  562. Say Y here to enable the kernel to detect "hung tasks",
  563. which are bugs that cause the task to be stuck in
  564. uninterruptible "D" state indefinitely.
  565. When a hung task is detected, the kernel will print the
  566. current stack trace (which you should report), but the
  567. task will stay in uninterruptible state. If lockdep is
  568. enabled then all held locks will also be reported. This
  569. feature has negligible overhead.
  570. config KERNEL_WQ_WATCHDOG
  571. bool "Compile the kernel with detect Workqueue Stalls"
  572. depends on KERNEL_DEBUG_KERNEL
  573. help
  574. Say Y here to enable stall detection on workqueues. If a
  575. worker pool doesn't make forward progress on a pending work
  576. item for over a given amount of time, 30s by default, a
  577. warning message is printed along with dump of workqueue
  578. state. This can be configured through kernel parameter
  579. "workqueue.watchdog_thresh" and its sysfs counterpart.
  580. config KERNEL_DEBUG_ATOMIC_SLEEP
  581. bool "Compile the kernel with sleep inside atomic section checking"
  582. depends on KERNEL_DEBUG_KERNEL
  583. help
  584. If you say Y here, various routines which may sleep will become very
  585. noisy if they are called inside atomic sections: when a spinlock is
  586. held, inside an rcu read side critical section, inside preempt disabled
  587. sections, inside an interrupt, etc...
  588. config KERNEL_DEBUG_VM
  589. bool "Compile the kernel with debug VM"
  590. depends on KERNEL_DEBUG_KERNEL
  591. help
  592. Enable this to turn on extended checks in the virtual-memory system
  593. that may impact performance.
  594. If unsure, say N.
  595. config KERNEL_PRINTK_TIME
  596. bool "Enable printk timestamps"
  597. default y
  598. config KERNEL_SLUB_DEBUG
  599. bool "Enable SLUB debugging support"
  600. help
  601. This enables various debugging features:
  602. - Accepts "slub_debug" kernel parameter
  603. - Provides caches debugging options (e.g. tracing, validating)
  604. - Adds /sys/kernel/slab/ attrs for reading amounts of *objects*
  605. - Enables /proc/slabinfo support
  606. - Prints info when running out of memory
  607. Enabling this can result in a significant increase of code size.
  608. config KERNEL_SLUB_DEBUG_ON
  609. depends on KERNEL_SLUB_DEBUG
  610. bool "Boot kernel with basic caches debugging enabled"
  611. help
  612. This enables by default sanity_checks, red_zone, poison and store_user
  613. debugging options for all caches.
  614. config KERNEL_SLABINFO
  615. select KERNEL_SLUB_DEBUG
  616. select KERNEL_SLUB_DEBUG_ON
  617. bool "Enable /proc slab debug info"
  618. config KERNEL_STACKDEPOT_MAX_FRAMES
  619. int
  620. default 64
  621. depends on KERNEL_SLUB_DEBUG
  622. config KERNEL_PROC_PAGE_MONITOR
  623. bool "Enable /proc page monitoring"
  624. config KERNEL_RELAY
  625. bool
  626. config KERNEL_KEXEC
  627. bool "Enable kexec support"
  628. config KERNEL_PROC_VMCORE
  629. bool
  630. config KERNEL_PROC_KCORE
  631. bool
  632. config KERNEL_CRASH_DUMP
  633. depends on i386 || x86_64 || arm || armeb
  634. select KERNEL_KEXEC
  635. select KERNEL_PROC_VMCORE
  636. select KERNEL_PROC_KCORE
  637. bool "Enable support for kexec crashdump"
  638. default y
  639. config USE_RFKILL
  640. bool "Enable rfkill support"
  641. default RFKILL_SUPPORT
  642. config USE_SPARSE
  643. bool "Enable sparse check during kernel build"
  644. config KERNEL_DEVTMPFS
  645. bool "Compile the kernel with device tmpfs enabled"
  646. help
  647. devtmpfs is a simple, kernel-managed /dev filesystem. The kernel creates
  648. devices nodes for all registered devices to simplify boot, but leaves more
  649. complex tasks to userspace (e.g. udev).
  650. if KERNEL_DEVTMPFS
  651. config KERNEL_DEVTMPFS_MOUNT
  652. bool "Automatically mount devtmpfs after root filesystem is mounted"
  653. endif
  654. config KERNEL_KEYS
  655. bool "Enable kernel access key retention support"
  656. default !SMALL_FLASH
  657. config KERNEL_PERSISTENT_KEYRINGS
  658. bool "Enable kernel persistent keyrings"
  659. depends on KERNEL_KEYS
  660. config KERNEL_KEYS_REQUEST_CACHE
  661. bool "Enable temporary caching of the last request_key() result"
  662. depends on KERNEL_KEYS
  663. config KERNEL_BIG_KEYS
  664. bool "Enable large payload keys on kernel keyrings"
  665. depends on KERNEL_KEYS
  666. #
  667. # CGROUP support symbols
  668. #
  669. config KERNEL_CGROUPS
  670. bool "Enable kernel cgroups"
  671. default y if !SMALL_FLASH
  672. if KERNEL_CGROUPS
  673. config KERNEL_CGROUP_DEBUG
  674. bool "Example debug cgroup subsystem"
  675. help
  676. This option enables a simple cgroup subsystem that
  677. exports useful debugging information about the cgroups
  678. framework.
  679. config KERNEL_FREEZER
  680. bool
  681. config KERNEL_CGROUP_FREEZER
  682. bool "legacy Freezer cgroup subsystem"
  683. select KERNEL_FREEZER
  684. help
  685. Provides a way to freeze and unfreeze all tasks in a
  686. cgroup.
  687. (legacy cgroup1-only controller, in cgroup2 freezer
  688. is integrated in the Memory controller)
  689. config KERNEL_CGROUP_DEVICE
  690. bool "legacy Device controller for cgroups"
  691. help
  692. Provides a cgroup implementing whitelists for devices which
  693. a process in the cgroup can mknod or open.
  694. (legacy cgroup1-only controller)
  695. config KERNEL_CGROUP_HUGETLB
  696. bool "HugeTLB controller"
  697. select KERNEL_HUGETLB_PAGE
  698. config KERNEL_CGROUP_PIDS
  699. bool "PIDs cgroup subsystem"
  700. default y
  701. help
  702. Provides enforcement of process number limits in the scope of a
  703. cgroup.
  704. config KERNEL_CGROUP_RDMA
  705. bool "RDMA controller for cgroups"
  706. default y
  707. config KERNEL_CGROUP_BPF
  708. bool "Support for eBPF programs attached to cgroups"
  709. default y
  710. config KERNEL_CPUSETS
  711. bool "Cpuset support"
  712. default y
  713. help
  714. This option will let you create and manage CPUSETs which
  715. allow dynamically partitioning a system into sets of CPUs and
  716. Memory Nodes and assigning tasks to run only within those sets.
  717. This is primarily useful on large SMP or NUMA systems.
  718. config KERNEL_CPUSETS_V1
  719. bool "Legacy cgroup v1 cpusets controller"
  720. depends on KERNEL_CPUSETS
  721. depends on !LINUX_6_6
  722. default n
  723. help
  724. Legacy cgroup v1 cpusets controller which has been deprecated by
  725. cgroup v2 implementation. The v1 is there for legacy applications
  726. which haven't migrated to the new cgroup v2 interface yet. If you
  727. do not have any such application then you are completely fine leaving
  728. this option disabled.
  729. config KERNEL_PROC_PID_CPUSET
  730. bool "Include legacy /proc/<pid>/cpuset file"
  731. depends on KERNEL_CPUSETS
  732. config KERNEL_CGROUP_CPUACCT
  733. bool "Simple CPU accounting cgroup subsystem"
  734. default y
  735. help
  736. Provides a simple Resource Controller for monitoring the
  737. total CPU consumed by the tasks in a cgroup.
  738. config KERNEL_RESOURCE_COUNTERS
  739. bool "Resource counters"
  740. default y
  741. help
  742. This option enables controller independent resource accounting
  743. infrastructure that works with cgroups.
  744. config KERNEL_MM_OWNER
  745. bool
  746. default y if KERNEL_MEMCG
  747. config KERNEL_MEMCG
  748. bool "Memory Resource Controller for Control Groups"
  749. default y
  750. select KERNEL_FREEZER
  751. depends on KERNEL_RESOURCE_COUNTERS
  752. help
  753. Provides a memory resource controller that manages both anonymous
  754. memory and page cache. (See Documentation/cgroups/memory.txt)
  755. Note that setting this option increases fixed memory overhead
  756. associated with each page of memory in the system. By this,
  757. 20(40)bytes/PAGE_SIZE on 32(64)bit system will be occupied by memory
  758. usage tracking struct at boot. Total amount of this is printed out
  759. at boot.
  760. Only enable when you're ok with these tradeoffs and really
  761. sure you need the memory resource controller. Even when you enable
  762. this, you can set "cgroup_disable=memory" at your boot option to
  763. disable memory resource controller and you can avoid overheads
  764. (but lose benefits of memory resource controller).
  765. This config option also selects MM_OWNER config option, which
  766. could in turn add some fork/exit overhead.
  767. config KERNEL_MEMCG_SWAP
  768. bool "Memory Resource Controller Swap Extension"
  769. default y
  770. depends on KERNEL_MEMCG
  771. help
  772. Add swap management feature to memory resource controller. When you
  773. enable this, you can limit mem+swap usage per cgroup. In other words,
  774. when you disable this, memory resource controller has no cares to
  775. usage of swap...a process can exhaust all of the swap. This extension
  776. is useful when you want to avoid exhaustion swap but this itself
  777. adds more overheads and consumes memory for remembering information.
  778. Especially if you use 32bit system or small memory system, please
  779. be careful about enabling this. When memory resource controller
  780. is disabled by boot option, this will be automatically disabled and
  781. there will be no overhead from this. Even when you set this config=y,
  782. if boot option "swapaccount=0" is set, swap will not be accounted.
  783. Now, memory usage of swap_cgroup is 2 bytes per entry. If swap page
  784. size is 4096bytes, 512k per 1Gbytes of swap.
  785. config KERNEL_MEMCG_SWAP_ENABLED
  786. bool "Memory Resource Controller Swap Extension enabled by default"
  787. depends on KERNEL_MEMCG_SWAP
  788. help
  789. Memory Resource Controller Swap Extension comes with its price in
  790. a bigger memory consumption. General purpose distribution kernels
  791. which want to enable the feature but keep it disabled by default
  792. and let the user enable it by swapaccount boot command line
  793. parameter should have this option unselected.
  794. Those who want to have the feature enabled by default should
  795. select this option (if, for some reason, they need to disable it,
  796. then swapaccount=0 does the trick).
  797. config KERNEL_MEMCG_KMEM
  798. bool "Memory Resource Controller Kernel Memory accounting (EXPERIMENTAL)"
  799. default y
  800. depends on KERNEL_MEMCG
  801. help
  802. The Kernel Memory extension for Memory Resource Controller can limit
  803. the amount of memory used by kernel objects in the system. Those are
  804. fundamentally different from the entities handled by the standard
  805. Memory Controller, which are page-based, and can be swapped. Users of
  806. the kmem extension can use it to guarantee that no group of processes
  807. will ever exhaust kernel resources alone.
  808. config KERNEL_MEMCG_V1
  809. bool "Legacy cgroup v1 memory controller"
  810. default n
  811. depends on KERNEL_MEMCG
  812. depends on !LINUX_6_6
  813. help
  814. Legacy cgroup v1 memory controller which has been deprecated by
  815. cgroup v2 implementation. The v1 is there for legacy applications
  816. which haven't migrated to the new cgroup v2 interface yet. If you
  817. do not have any such application then you are completely fine leaving
  818. this option disabled.
  819. Please note that feature set of the legacy memory controller is likely
  820. going to shrink due to deprecation process. New deployments with v1
  821. controller are highly discouraged.
  822. config KERNEL_CGROUP_PERF
  823. bool "Enable perf_event per-cpu per-container group (cgroup) monitoring"
  824. select KERNEL_PERF_EVENTS
  825. help
  826. This option extends the per-cpu mode to restrict monitoring to
  827. threads which belong to the cgroup specified and run on the
  828. designated cpu.
  829. menuconfig KERNEL_CGROUP_SCHED
  830. bool "Group CPU scheduler"
  831. default y
  832. help
  833. This feature lets CPU scheduler recognize task groups and control CPU
  834. bandwidth allocation to such task groups. It uses cgroups to group
  835. tasks.
  836. if KERNEL_CGROUP_SCHED
  837. config KERNEL_FAIR_GROUP_SCHED
  838. bool "Group scheduling for SCHED_OTHER"
  839. default y
  840. config KERNEL_CFS_BANDWIDTH
  841. bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
  842. default y
  843. depends on KERNEL_FAIR_GROUP_SCHED
  844. help
  845. This option allows users to define CPU bandwidth rates (limits) for
  846. tasks running within the fair group scheduler. Groups with no limit
  847. set are considered to be unconstrained and will run with no
  848. restriction.
  849. See tip/Documentation/scheduler/sched-bwc.txt for more information.
  850. config KERNEL_RT_GROUP_SCHED
  851. bool "Group scheduling for SCHED_RR/FIFO"
  852. default y
  853. help
  854. This feature lets you explicitly allocate real CPU bandwidth
  855. to task groups. If enabled, it will also make it impossible to
  856. schedule realtime tasks for non-root users until you allocate
  857. realtime bandwidth for them.
  858. endif
  859. config KERNEL_BLK_CGROUP
  860. bool "Block IO controller"
  861. default y
  862. help
  863. Generic block IO controller cgroup interface. This is the common
  864. cgroup interface which should be used by various IO controlling
  865. policies.
  866. Currently, CFQ IO scheduler uses it to recognize task groups and
  867. control disk bandwidth allocation (proportional time slice allocation)
  868. to such task groups. It is also used by bio throttling logic in
  869. block layer to implement upper limit in IO rates on a device.
  870. This option only enables generic Block IO controller infrastructure.
  871. One needs to also enable actual IO controlling logic/policy. For
  872. enabling proportional weight division of disk bandwidth in CFQ, set
  873. CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
  874. CONFIG_BLK_DEV_THROTTLING=y.
  875. if KERNEL_BLK_CGROUP
  876. config KERNEL_CFQ_GROUP_IOSCHED
  877. bool "Proportional weight of disk bandwidth in CFQ"
  878. config KERNEL_BLK_DEV_THROTTLING
  879. bool "Enable throttling policy"
  880. default y
  881. config KERNEL_BLK_DEV_THROTTLING_LOW
  882. bool "Block throttling .low limit interface support (EXPERIMENTAL)"
  883. depends on KERNEL_BLK_DEV_THROTTLING
  884. endif
  885. config KERNEL_DEBUG_BLK_CGROUP
  886. bool "Enable Block IO controller debugging"
  887. depends on KERNEL_BLK_CGROUP
  888. help
  889. Enable some debugging help. Currently it exports additional stat
  890. files in a cgroup which can be useful for debugging.
  891. config KERNEL_NET_CLS_CGROUP
  892. bool "legacy Control Group Classifier"
  893. config KERNEL_CGROUP_NET_CLASSID
  894. bool "legacy Network classid cgroup"
  895. config KERNEL_CGROUP_NET_PRIO
  896. bool "legacy Network priority cgroup"
  897. endif
  898. #
  899. # Namespace support symbols
  900. #
  901. config KERNEL_NAMESPACES
  902. bool "Enable kernel namespaces"
  903. default y if !SMALL_FLASH
  904. if KERNEL_NAMESPACES
  905. config KERNEL_UTS_NS
  906. bool "UTS namespace"
  907. default y
  908. help
  909. In this namespace, tasks see different info provided
  910. with the uname() system call.
  911. config KERNEL_IPC_NS
  912. bool "IPC namespace"
  913. default y
  914. help
  915. In this namespace, tasks work with IPC ids which correspond to
  916. different IPC objects in different namespaces.
  917. config KERNEL_USER_NS
  918. bool "User namespace (EXPERIMENTAL)"
  919. default y
  920. help
  921. This allows containers, i.e. vservers, to use user namespaces
  922. to provide different user info for different servers.
  923. config KERNEL_PID_NS
  924. bool "PID Namespaces"
  925. default y
  926. help
  927. Support process id namespaces. This allows having multiple
  928. processes with the same pid as long as they are in different
  929. pid namespaces. This is a building block of containers.
  930. config KERNEL_NET_NS
  931. bool "Network namespace"
  932. default y
  933. help
  934. Allow user space to create what appear to be multiple instances
  935. of the network stack.
  936. endif
  937. config KERNEL_DEVPTS_MULTIPLE_INSTANCES
  938. bool "Support multiple instances of devpts"
  939. default y if !SMALL_FLASH
  940. help
  941. Enable support for multiple instances of devpts filesystem.
  942. If you want to have isolated PTY namespaces (eg: in containers),
  943. say Y here. Otherwise, say N. If enabled, each mount of devpts
  944. filesystem with the '-o newinstance' option will create an
  945. independent PTY namespace.
  946. config KERNEL_POSIX_MQUEUE
  947. bool "POSIX Message Queues"
  948. default y if !SMALL_FLASH
  949. help
  950. POSIX variant of message queues is a part of IPC. In POSIX message
  951. queues every message has a priority which decides about succession
  952. of receiving it by a process. If you want to compile and run
  953. programs written e.g. for Solaris with use of its POSIX message
  954. queues (functions mq_*) say Y here.
  955. POSIX message queues are visible as a filesystem called 'mqueue'
  956. and can be mounted somewhere if you want to do filesystem
  957. operations on message queues.
  958. config KERNEL_SECCOMP_FILTER
  959. bool
  960. default y if !SMALL_FLASH
  961. config KERNEL_SECCOMP
  962. bool "Enable seccomp support"
  963. depends on !(TARGET_uml)
  964. select KERNEL_SECCOMP_FILTER
  965. default y if !SMALL_FLASH
  966. help
  967. Build kernel with support for seccomp.
  968. #
  969. # IPv4 configuration
  970. #
  971. config KERNEL_IP_MROUTE
  972. bool "Enable IPv4 multicast routing"
  973. default y
  974. help
  975. Multicast routing requires a multicast routing daemon in
  976. addition to kernel support.
  977. if KERNEL_IP_MROUTE
  978. config KERNEL_IP_MROUTE_MULTIPLE_TABLES
  979. def_bool y
  980. config KERNEL_IP_PIMSM_V1
  981. def_bool y
  982. config KERNEL_IP_PIMSM_V2
  983. def_bool y
  984. endif
  985. #
  986. # IPv6 configuration
  987. #
  988. config KERNEL_IPV6
  989. def_bool IPV6
  990. if KERNEL_IPV6
  991. config KERNEL_IPV6_MULTIPLE_TABLES
  992. def_bool y
  993. config KERNEL_IPV6_SUBTREES
  994. def_bool y
  995. config KERNEL_IPV6_MROUTE
  996. bool "Enable IPv6 multicast routing"
  997. default y
  998. help
  999. Multicast routing requires a multicast routing daemon in
  1000. addition to kernel support.
  1001. if KERNEL_IPV6_MROUTE
  1002. config KERNEL_IPV6_MROUTE_MULTIPLE_TABLES
  1003. def_bool y
  1004. config KERNEL_IPV6_PIMSM_V2
  1005. def_bool y
  1006. endif
  1007. config KERNEL_IPV6_SEG6_LWTUNNEL
  1008. bool "Enable support for lightweight tunnels"
  1009. default y if !SMALL_FLASH
  1010. help
  1011. Using lwtunnel (needed for IPv6 segment routing) requires ip-full package.
  1012. config KERNEL_LWTUNNEL_BPF
  1013. def_bool n
  1014. endif
  1015. #
  1016. # Miscellaneous network configuration
  1017. #
  1018. config KERNEL_NET_L3_MASTER_DEV
  1019. bool "L3 Master device support"
  1020. default y if !SMALL_FLASH
  1021. help
  1022. This module provides glue between core networking code and device
  1023. drivers to support L3 master devices like VRF.
  1024. Increases the compressed kernel size by ~4kB (as of Linux 6.6).
  1025. config KERNEL_DCB
  1026. bool "Data Center Bridging support"
  1027. default y if TARGET_armsr_armv8
  1028. default y if TARGET_x86_64
  1029. help
  1030. This enables support for configuring Data Center Bridging (DCB)
  1031. features on DCB capable Ethernet adapters via rtnetlink. Say 'Y'
  1032. if you have a DCB capable Ethernet adapter which supports this
  1033. interface and you are connected to a DCB capable switch.
  1034. DCB is a collection of Ethernet enhancements which allow DCB capable
  1035. NICs and switches to support network traffic with differing
  1036. requirements (highly reliable, no drops vs. best effort vs. low
  1037. latency) to co-exist on Ethernet.
  1038. DCB features include:
  1039. Enhanced Transmission Selection (aka Priority Grouping) - provides a
  1040. framework for assigning bandwidth guarantees to traffic classes.
  1041. Priority-based Flow Control (PFC) - a MAC control pause frame which
  1042. works at the granularity of the 802.1p priority instead of the
  1043. link (802.3x).
  1044. config KERNEL_XDP_SOCKETS
  1045. bool "XDP sockets support"
  1046. help
  1047. XDP sockets allows a channel between XDP programs and
  1048. userspace applications.
  1049. config KERNEL_PAGE_POOL
  1050. def_bool n
  1051. config KERNEL_PAGE_POOL_STATS
  1052. bool "Page pool stats support"
  1053. depends on KERNEL_PAGE_POOL
  1054. config KERNEL_MPTCP
  1055. bool "Multi-Path TCP support"
  1056. default y if !SMALL_FLASH
  1057. help
  1058. Select this option to enable support for Multi-Path TCP.
  1059. Increases the compressed kernel size by ~214kB (as of Linux 6.6).
  1060. if KERNEL_IPV6
  1061. config KERNEL_MPTCP_IPV6
  1062. bool "IPv6 support for Multipath TCP"
  1063. depends on KERNEL_MPTCP
  1064. default KERNEL_MPTCP
  1065. endif
  1066. config KERNEL_NF_CONNTRACK_TIMEOUT
  1067. bool "Per-connection connection tracking timeout"
  1068. default y if !SMALL_FLASH
  1069. help
  1070. Select this option to enable support for per-connection conntrack timeouts.
  1071. Increases the (uncompressed) size of nf_conntrack.ko by ~8kB.
  1072. #
  1073. # NFS related symbols
  1074. #
  1075. config KERNEL_IP_PNP
  1076. bool "Compile the kernel with rootfs on NFS"
  1077. help
  1078. If you want to make your kernel boot off a NFS server as root
  1079. filesystem, select Y here.
  1080. if KERNEL_IP_PNP
  1081. config KERNEL_IP_PNP_DHCP
  1082. def_bool y
  1083. config KERNEL_IP_PNP_BOOTP
  1084. def_bool n
  1085. config KERNEL_IP_PNP_RARP
  1086. def_bool n
  1087. config KERNEL_NFS_FS
  1088. def_bool y
  1089. config KERNEL_NFS_V2
  1090. def_bool y
  1091. config KERNEL_NFS_V3
  1092. def_bool y
  1093. config KERNEL_ROOT_NFS
  1094. def_bool y
  1095. endif
  1096. config KERNEL_BTRFS_FS
  1097. bool "Compile the kernel with built-in BTRFS support"
  1098. help
  1099. Say Y here if you want to make the kernel to be able to boot off a
  1100. BTRFS partition.
  1101. menu "Filesystem ACL and attr support options"
  1102. config USE_FS_ACL_ATTR
  1103. bool "Use filesystem ACL and attr support by default"
  1104. default y if !SMALL_FLASH
  1105. help
  1106. Make using ACLs (e.g. POSIX ACL, NFSv4 ACL) the default
  1107. for kernel and packages, except old NFS.
  1108. Also enable userspace extended attribute support
  1109. by default. (OpenWrt already has an expection it will be
  1110. present in the kernel).
  1111. config KERNEL_FS_POSIX_ACL
  1112. bool "Enable POSIX ACL support"
  1113. default y if USE_FS_ACL_ATTR
  1114. config KERNEL_BTRFS_FS_POSIX_ACL
  1115. bool "Enable POSIX ACL for BtrFS Filesystems"
  1116. select KERNEL_FS_POSIX_ACL
  1117. default y if USE_FS_ACL_ATTR
  1118. config KERNEL_EXT4_FS_POSIX_ACL
  1119. bool "Enable POSIX ACL for Ext4 Filesystems"
  1120. select KERNEL_FS_POSIX_ACL
  1121. default y if USE_FS_ACL_ATTR
  1122. config KERNEL_F2FS_FS_POSIX_ACL
  1123. bool "Enable POSIX ACL for F2FS Filesystems"
  1124. select KERNEL_FS_POSIX_ACL
  1125. default y if USE_FS_ACL_ATTR
  1126. config KERNEL_JFFS2_FS_POSIX_ACL
  1127. bool "Enable POSIX ACL for JFFS2 Filesystems"
  1128. select KERNEL_FS_POSIX_ACL
  1129. default y if USE_FS_ACL_ATTR
  1130. config KERNEL_TMPFS_POSIX_ACL
  1131. bool "Enable POSIX ACL for TMPFS Filesystems"
  1132. select KERNEL_FS_POSIX_ACL
  1133. default y if USE_FS_ACL_ATTR
  1134. config KERNEL_CIFS_ACL
  1135. bool "Enable CIFS ACLs"
  1136. select KERNEL_FS_POSIX_ACL
  1137. default y if USE_FS_ACL_ATTR
  1138. config KERNEL_HFS_FS_POSIX_ACL
  1139. bool "Enable POSIX ACL for HFS Filesystems"
  1140. select KERNEL_FS_POSIX_ACL
  1141. default y if USE_FS_ACL_ATTR
  1142. config KERNEL_HFSPLUS_FS_POSIX_ACL
  1143. bool "Enable POSIX ACL for HFS+ Filesystems"
  1144. select KERNEL_FS_POSIX_ACL
  1145. default y if USE_FS_ACL_ATTR
  1146. config KERNEL_NFS_ACL_SUPPORT
  1147. bool "Enable ACLs for NFS"
  1148. default y if USE_FS_ACL_ATTR
  1149. config KERNEL_NFS_V3_ACL_SUPPORT
  1150. bool "Enable ACLs for NFSv3"
  1151. config KERNEL_NFSD_V2_ACL_SUPPORT
  1152. bool "Enable ACLs for NFSDv2"
  1153. config KERNEL_NFSD_V3_ACL_SUPPORT
  1154. bool "Enable ACLs for NFSDv3"
  1155. config KERNEL_REISER_FS_POSIX_ACL
  1156. bool "Enable POSIX ACLs for ReiserFS"
  1157. select KERNEL_FS_POSIX_ACL
  1158. default y if USE_FS_ACL_ATTR
  1159. config KERNEL_XFS_POSIX_ACL
  1160. bool "Enable POSIX ACLs for XFS"
  1161. select KERNEL_FS_POSIX_ACL
  1162. default y if USE_FS_ACL_ATTR
  1163. config KERNEL_JFS_POSIX_ACL
  1164. bool "Enable POSIX ACLs for JFS"
  1165. select KERNEL_FS_POSIX_ACL
  1166. default y if USE_FS_ACL_ATTR
  1167. endmenu
  1168. config KERNEL_DEVMEM
  1169. bool "/dev/mem virtual device support"
  1170. help
  1171. Say Y here if you want to support the /dev/mem device.
  1172. The /dev/mem device is used to access areas of physical
  1173. memory.
  1174. config KERNEL_DEVKMEM
  1175. bool "/dev/kmem virtual device support"
  1176. help
  1177. Say Y here if you want to support the /dev/kmem device. The
  1178. /dev/kmem device is rarely used, but can be used for certain
  1179. kind of kernel debugging operations.
  1180. config KERNEL_SQUASHFS_FRAGMENT_CACHE_SIZE
  1181. int "Number of squashfs fragments cached"
  1182. default 2 if (SMALL_FLASH && !LOW_MEMORY_FOOTPRINT)
  1183. default 3
  1184. config KERNEL_SQUASHFS_XATTR
  1185. bool "Squashfs XATTR support"
  1186. #
  1187. # compile optimization setting
  1188. #
  1189. choice
  1190. prompt "Compiler optimization level"
  1191. default KERNEL_CC_OPTIMIZE_FOR_SIZE if SMALL_FLASH
  1192. config KERNEL_CC_OPTIMIZE_FOR_PERFORMANCE
  1193. bool "Optimize for performance"
  1194. help
  1195. This is the default optimization level for the kernel, building
  1196. with the "-O2" compiler flag for best performance and most
  1197. helpful compile-time warnings.
  1198. config KERNEL_CC_OPTIMIZE_FOR_SIZE
  1199. bool "Optimize for size"
  1200. help
  1201. Enabling this option will pass "-Os" instead of "-O2" to
  1202. your compiler resulting in a smaller kernel.
  1203. endchoice
  1204. config KERNEL_AUDIT
  1205. bool "Auditing support"
  1206. config KERNEL_SECURITY
  1207. bool "Enable different security models"
  1208. config KERNEL_SECURITY_NETWORK
  1209. bool "Socket and Networking Security Hooks"
  1210. select KERNEL_SECURITY
  1211. config KERNEL_SECURITY_SELINUX
  1212. bool "NSA SELinux Support"
  1213. select KERNEL_SECURITY_NETWORK
  1214. select KERNEL_AUDIT
  1215. config KERNEL_SECURITY_SELINUX_BOOTPARAM
  1216. bool "NSA SELinux boot parameter"
  1217. depends on KERNEL_SECURITY_SELINUX
  1218. default y
  1219. config KERNEL_SECURITY_SELINUX_DISABLE
  1220. bool "NSA SELinux runtime disable"
  1221. depends on KERNEL_SECURITY_SELINUX
  1222. config KERNEL_SECURITY_SELINUX_DEVELOP
  1223. bool "NSA SELinux Development Support"
  1224. depends on KERNEL_SECURITY_SELINUX
  1225. default y
  1226. config KERNEL_SECURITY_SELINUX_SIDTAB_HASH_BITS
  1227. int
  1228. depends on KERNEL_SECURITY_SELINUX
  1229. default 9
  1230. config KERNEL_SECURITY_SELINUX_SID2STR_CACHE_SIZE
  1231. int
  1232. depends on KERNEL_SECURITY_SELINUX
  1233. default 256
  1234. config KERNEL_LSM
  1235. string
  1236. default "lockdown,yama,loadpin,safesetid,integrity,selinux"
  1237. depends on KERNEL_SECURITY_SELINUX
  1238. config KERNEL_EXT4_FS_SECURITY
  1239. bool "Ext4 Security Labels"
  1240. default y if !SMALL_FLASH
  1241. config KERNEL_F2FS_FS_SECURITY
  1242. bool "F2FS Security Labels"
  1243. default y if !SMALL_FLASH
  1244. config KERNEL_UBIFS_FS_SECURITY
  1245. bool "UBIFS Security Labels"
  1246. default y if !SMALL_FLASH
  1247. config KERNEL_JFFS2_FS_SECURITY
  1248. bool "JFFS2 Security Labels"
  1249. default y if !SMALL_FLASH
  1250. config KERNEL_WERROR
  1251. bool "Compile the kernel with warnings as errors"
  1252. help
  1253. A kernel build should not cause any compiler warnings, and this
  1254. enables the '-Werror' (for C) and '-Dwarnings' (for Rust) flags
  1255. to enforce that rule by default. Certain warnings from other tools
  1256. such as the linker may be upgraded to errors with this option as
  1257. well.
  1258. However, if you have a new (or very old) compiler or linker with odd
  1259. and unusual warnings, or you have some architecture with problems,
  1260. you may need to disable this config option in order to
  1261. successfully build the kernel.