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Greg Kroah-Hartmanb2441312017-11-01 15:07:57 +01001# SPDX-License-Identifier: GPL-2.0
Mathieu Desnoyersfb32e032008-02-02 15:10:33 -05002#
3# General architecture dependent options
4#
Mathieu Desnoyers125e5642008-02-02 15:10:36 -05005
Christoph Hellwig15724972018-07-31 13:39:30 +02006#
7# Note: arch/$(SRCARCH)/Kconfig needs to be included first so that it can
8# override the default values in this file.
9#
10source "arch/$(SRCARCH)/Kconfig"
11
Randy Dunlap22471e12018-07-31 13:39:33 +020012menu "General architecture-dependent options"
13
Hari Bathini692f66f2017-05-08 15:56:18 -070014config CRASH_CORE
15 bool
16
Dave Young2965faa2015-09-09 15:38:55 -070017config KEXEC_CORE
Hari Bathini692f66f2017-05-08 15:56:18 -070018 select CRASH_CORE
Dave Young2965faa2015-09-09 15:38:55 -070019 bool
20
Sven Schnelle175fca32019-08-23 21:49:13 +020021config KEXEC_ELF
22 bool
23
Thiago Jung Bauermann467d2782016-12-19 16:22:32 -080024config HAVE_IMA_KEXEC
25 bool
26
Catalin Marinasda32b582022-04-23 11:07:49 +010027config ARCH_HAS_SUBPAGE_FAULTS
28 bool
29 help
30 Select if the architecture can check permissions at sub-page
31 granularity (e.g. arm64 MTE). The probe_user_*() functions
32 must be implemented.
33
Thomas Gleixner05736e42018-05-29 17:48:27 +020034config HOTPLUG_SMT
35 bool
36
Thomas Gleixner142781e2020-07-22 23:59:56 +020037config GENERIC_ENTRY
38 bool
39
Mathieu Desnoyers125e5642008-02-02 15:10:36 -050040config KPROBES
41 bool "Kprobes"
Masami Hiramatsu05ed1602010-09-13 19:25:41 +090042 depends on MODULES
Mathieu Desnoyers125e5642008-02-02 15:10:36 -050043 depends on HAVE_KPROBES
Masami Hiramatsu05ed1602010-09-13 19:25:41 +090044 select KALLSYMS
Paul E. McKenney835f14e2022-03-17 11:05:09 -070045 select TASKS_RCU if PREEMPTION
Mathieu Desnoyers125e5642008-02-02 15:10:36 -050046 help
47 Kprobes allows you to trap at almost any kernel address and
48 execute a callback function. register_kprobe() establishes
49 a probepoint and specifies the callback. Kprobes is useful
50 for kernel debugging, non-intrusive instrumentation and testing.
51 If in doubt, say "N".
52
Steven Rostedt45f81b12010-10-29 12:33:43 -040053config JUMP_LABEL
Krzysztof Kozlowski24b54fe2019-12-04 16:50:26 -080054 bool "Optimize very unlikely/likely branches"
55 depends on HAVE_ARCH_JUMP_LABEL
Josh Poimboeuf4ab76742022-04-18 09:50:39 -070056 select OBJTOOL if HAVE_JUMP_LABEL_HACK
Krzysztof Kozlowski24b54fe2019-12-04 16:50:26 -080057 help
58 This option enables a transparent branch optimization that
Ingo Molnarc5905af2012-02-24 08:31:31 +010059 makes certain almost-always-true or almost-always-false branch
60 conditions even cheaper to execute within the kernel.
Steven Rostedt45f81b12010-10-29 12:33:43 -040061
Ingo Molnarc5905af2012-02-24 08:31:31 +010062 Certain performance-sensitive kernel code, such as trace points,
63 scheduler functionality, networking code and KVM have such
64 branches and include support for this optimization technique.
65
Krzysztof Kozlowski24b54fe2019-12-04 16:50:26 -080066 If it is detected that the compiler has support for "asm goto",
Ingo Molnarc5905af2012-02-24 08:31:31 +010067 the kernel will compile such branches with just a nop
68 instruction. When the condition flag is toggled to true, the
69 nop will be converted to a jump instruction to execute the
70 conditional block of instructions.
71
72 This technique lowers overhead and stress on the branch prediction
73 of the processor and generally makes the kernel faster. The update
74 of the condition is slower, but those are always very rare.
75
76 ( On 32-bit x86, the necessary options added to the compiler
77 flags may increase the size of the kernel slightly. )
Steven Rostedt45f81b12010-10-29 12:33:43 -040078
Peter Zijlstra1987c942015-07-27 18:32:09 +020079config STATIC_KEYS_SELFTEST
80 bool "Static key selftest"
81 depends on JUMP_LABEL
82 help
83 Boot time self-test of the branch patching code.
84
Peter Zijlstraf03c4122020-08-18 15:57:46 +020085config STATIC_CALL_SELFTEST
86 bool "Static call selftest"
87 depends on HAVE_STATIC_CALL
88 help
89 Boot time self-test of the call patching code.
90
Masami Hiramatsuafd66252010-02-25 08:34:07 -050091config OPTPROBES
Masami Hiramatsu5cc718b2010-03-15 13:00:54 -040092 def_bool y
93 depends on KPROBES && HAVE_OPTPROBES
Thomas Gleixner01b1d882019-07-26 23:19:38 +020094 select TASKS_RCU if PREEMPTION
Masami Hiramatsuafd66252010-02-25 08:34:07 -050095
Masami Hiramatsue7dbfe32012-09-28 17:15:20 +090096config KPROBES_ON_FTRACE
97 def_bool y
98 depends on KPROBES && HAVE_KPROBES_ON_FTRACE
99 depends on DYNAMIC_FTRACE_WITH_REGS
100 help
101 If function tracer is enabled and the arch supports full
102 passing of pt_regs to function tracing, then kprobes can
103 optimize on top of function tracing.
104
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530105config UPROBES
David A. Long09294e32014-03-07 10:32:22 -0500106 def_bool n
Allen Paise8f4aa62016-10-13 10:06:13 +0530107 depends on ARCH_SUPPORTS_UPROBES
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530108 help
Ingo Molnar7b2d81d2012-02-17 09:27:41 +0100109 Uprobes is the user-space counterpart to kprobes: they
110 enable instrumentation applications (such as 'perf probe')
111 to establish unintrusive probes in user-space binaries and
112 libraries, by executing handler functions when the probes
113 are hit by user-space applications.
114
115 ( These probes come in the form of single-byte breakpoints,
116 managed by the kernel and kept transparent to the probed
117 application. )
Srikar Dronamraju2b144492012-02-09 14:56:42 +0530118
Steven Rostedt (VMware)adab66b2020-12-14 12:33:51 -0500119config HAVE_64BIT_ALIGNED_ACCESS
120 def_bool 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS
121 help
122 Some architectures require 64 bit accesses to be 64 bit
123 aligned, which also requires structs containing 64 bit values
124 to be 64 bit aligned too. This includes some 32 bit
125 architectures which can do 64 bit accesses, as well as 64 bit
126 architectures without unaligned access.
127
128 This symbol should be selected by an architecture if 64 bit
129 accesses are required to be 64 bit aligned in this way even
130 though it is not a 64 bit architecture.
131
Lukas Bulwahnba1a2972021-01-19 10:53:26 +0100132 See Documentation/core-api/unaligned-memory-access.rst for
133 more information on the topic of unaligned memory accesses.
Steven Rostedt (VMware)adab66b2020-12-14 12:33:51 -0500134
Johannes Berg58340a02008-07-25 01:45:33 -0700135config HAVE_EFFICIENT_UNALIGNED_ACCESS
Jan Beulich9ba16082008-10-15 22:01:38 -0700136 bool
Johannes Berg58340a02008-07-25 01:45:33 -0700137 help
138 Some architectures are unable to perform unaligned accesses
139 without the use of get_unaligned/put_unaligned. Others are
140 unable to perform such accesses efficiently (e.g. trap on
141 unaligned access and require fixing it up in the exception
142 handler.)
143
144 This symbol should be selected by an architecture if it can
145 perform unaligned accesses efficiently to allow different
146 code paths to be selected for these cases. Some network
147 drivers, for example, could opt to not fix up alignment
148 problems with received packets if doing so would not help
149 much.
150
Mauro Carvalho Chehabc9b54d62020-06-23 15:31:38 +0200151 See Documentation/core-api/unaligned-memory-access.rst for more
Johannes Berg58340a02008-07-25 01:45:33 -0700152 information on the topic of unaligned memory accesses.
153
David Woodhousecf66bb92012-12-03 16:25:40 +0000154config ARCH_USE_BUILTIN_BSWAP
Krzysztof Kozlowski24b54fe2019-12-04 16:50:26 -0800155 bool
156 help
David Woodhousecf66bb92012-12-03 16:25:40 +0000157 Modern versions of GCC (since 4.4) have builtin functions
158 for handling byte-swapping. Using these, instead of the old
159 inline assembler that the architecture code provides in the
160 __arch_bswapXX() macros, allows the compiler to see what's
161 happening and offers more opportunity for optimisation. In
162 particular, the compiler will be able to combine the byteswap
163 with a nearby load or store and use load-and-swap or
164 store-and-swap instructions if the architecture has them. It
165 should almost *never* result in code which is worse than the
166 hand-coded assembler in <asm/swab.h>. But just in case it
167 does, the use of the builtins is optional.
168
169 Any architecture with load-and-swap or store-and-swap
170 instructions should set this. And it shouldn't hurt to set it
171 on architectures that don't have such instructions.
172
Ananth N Mavinakayanahalli9edddaa2008-03-04 14:28:37 -0800173config KRETPROBES
174 def_bool y
Masami Hiramatsu73f9b912022-03-26 11:27:05 +0900175 depends on KPROBES && (HAVE_KRETPROBES || HAVE_RETHOOK)
176
177config KRETPROBE_ON_RETHOOK
178 def_bool y
179 depends on HAVE_RETHOOK
180 depends on KRETPROBES
181 select RETHOOK
Ananth N Mavinakayanahalli9edddaa2008-03-04 14:28:37 -0800182
Avi Kivity7c68af62009-09-19 09:40:22 +0300183config USER_RETURN_NOTIFIER
184 bool
185 depends on HAVE_USER_RETURN_NOTIFIER
186 help
187 Provide a kernel-internal notification when a cpu is about to
188 switch to user mode.
189
Rik van Riel28b2ee22008-07-23 21:27:05 -0700190config HAVE_IOREMAP_PROT
Jan Beulich9ba16082008-10-15 22:01:38 -0700191 bool
Rik van Riel28b2ee22008-07-23 21:27:05 -0700192
Mathieu Desnoyers125e5642008-02-02 15:10:36 -0500193config HAVE_KPROBES
Jan Beulich9ba16082008-10-15 22:01:38 -0700194 bool
Ananth N Mavinakayanahalli9edddaa2008-03-04 14:28:37 -0800195
196config HAVE_KRETPROBES
Jan Beulich9ba16082008-10-15 22:01:38 -0700197 bool
Arthur Kepner74bc7ce2008-04-29 01:00:30 -0700198
Masami Hiramatsuafd66252010-02-25 08:34:07 -0500199config HAVE_OPTPROBES
200 bool
Cong Wangd314d742012-03-23 15:01:51 -0700201
Masami Hiramatsue7dbfe32012-09-28 17:15:20 +0900202config HAVE_KPROBES_ON_FTRACE
203 bool
204
Masami Hiramatsu1f6d3a82021-10-25 20:41:52 +0900205config ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
206 bool
207 help
208 Since kretprobes modifies return address on the stack, the
209 stacktrace may see the kretprobe trampoline address instead
210 of correct one. If the architecture stacktrace code and
211 unwinder can adjust such entries, select this configuration.
212
Masami Hiramatsu540adea2018-01-13 02:55:03 +0900213config HAVE_FUNCTION_ERROR_INJECTION
Josef Bacik9802d862017-12-11 11:36:48 -0500214 bool
215
Petr Mladek42a0bb32016-05-20 17:00:33 -0700216config HAVE_NMI
217 bool
218
Christophe Leroya257cac2022-02-15 13:41:02 +0100219config HAVE_FUNCTION_DESCRIPTORS
220 bool
221
Masahiro Yamada4aae6832021-07-31 14:22:32 +0900222config TRACE_IRQFLAGS_SUPPORT
223 bool
224
Mark Rutland4510bff2022-05-11 14:17:32 +0100225config TRACE_IRQFLAGS_NMI_SUPPORT
226 bool
227
Roland McGrath1f5a4ad2008-07-25 19:45:57 -0700228#
229# An arch should select this if it provides all these things:
230#
231# task_pt_regs() in asm/processor.h or asm/ptrace.h
232# arch_has_single_step() if there is hardware single-step support
233# arch_has_block_step() if there is hardware block-step support
Roland McGrath1f5a4ad2008-07-25 19:45:57 -0700234# asm/syscall.h supplying asm-generic/syscall.h interface
235# linux/regset.h user_regset interfaces
236# CORE_DUMP_USE_REGSET #define'd in linux/elf.h
Eric W. Biederman153474b2022-01-27 11:46:37 -0600237# TIF_SYSCALL_TRACE calls ptrace_report_syscall_{entry,exit}
Eric W. Biederman03248ad2022-02-09 12:20:45 -0600238# TIF_NOTIFY_RESUME calls resume_user_mode_work()
Roland McGrath1f5a4ad2008-07-25 19:45:57 -0700239#
240config HAVE_ARCH_TRACEHOOK
Jan Beulich9ba16082008-10-15 22:01:38 -0700241 bool
Roland McGrath1f5a4ad2008-07-25 19:45:57 -0700242
Marek Szyprowskic64be2b2011-12-29 13:09:51 +0100243config HAVE_DMA_CONTIGUOUS
244 bool
245
Thomas Gleixner29d5e042012-04-20 13:05:45 +0000246config GENERIC_SMP_IDLE_THREAD
Krzysztof Kozlowski24b54fe2019-12-04 16:50:26 -0800247 bool
Thomas Gleixner29d5e042012-04-20 13:05:45 +0000248
Kevin Hilman485cf5d2013-04-24 17:19:13 -0700249config GENERIC_IDLE_POLL_SETUP
Krzysztof Kozlowski24b54fe2019-12-04 16:50:26 -0800250 bool
Kevin Hilman485cf5d2013-04-24 17:19:13 -0700251
Daniel Micay6974f0c2017-07-12 14:36:10 -0700252config ARCH_HAS_FORTIFY_SOURCE
253 bool
254 help
255 An architecture should select this when it can successfully
256 build and run with CONFIG_FORTIFY_SOURCE.
257
Christoph Hellwigd8ae8a32019-05-13 17:18:30 -0700258#
259# Select if the arch provides a historic keepinit alias for the retain_initrd
260# command line option
261#
262config ARCH_HAS_KEEPINITRD
263 bool
264
Daniel Borkmannd2852a22017-02-21 16:09:33 +0100265# Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h
266config ARCH_HAS_SET_MEMORY
267 bool
268
Rick Edgecombed253ca02019-04-25 17:11:34 -0700269# Select if arch has all set_direct_map_invalid/default() functions
270config ARCH_HAS_SET_DIRECT_MAP
271 bool
272
Christoph Hellwigc30700d2019-06-03 08:43:51 +0200273#
Christoph Hellwigfa7e2242020-02-21 15:55:43 -0800274# Select if the architecture provides the arch_dma_set_uncached symbol to
Colin Ian Kinga86ecfa2020-12-14 19:03:44 -0800275# either provide an uncached segment alias for a DMA allocation, or
Christoph Hellwigfa7e2242020-02-21 15:55:43 -0800276# to remap the page tables in place.
Christoph Hellwigc30700d2019-06-03 08:43:51 +0200277#
Christoph Hellwigfa7e2242020-02-21 15:55:43 -0800278config ARCH_HAS_DMA_SET_UNCACHED
Christoph Hellwigc30700d2019-06-03 08:43:51 +0200279 bool
280
Christoph Hellwig999a5d12020-02-21 12:35:05 -0800281#
282# Select if the architectures provides the arch_dma_clear_uncached symbol
283# to undo an in-place page table remap for uncached access.
284#
285config ARCH_HAS_DMA_CLEAR_UNCACHED
Thomas Gleixnerf5e10282012-05-05 15:05:48 +0000286 bool
287
Kees Cook59054292017-08-16 13:00:58 -0700288# Select if arch init_task must go in the __init_task_data section
289config ARCH_TASK_STRUCT_ON_STACK
Krzysztof Kozlowski24b54fe2019-12-04 16:50:26 -0800290 bool
Thomas Gleixnera4a2eb42012-05-03 09:02:48 +0000291
Thomas Gleixnerf5e10282012-05-05 15:05:48 +0000292# Select if arch has its private alloc_task_struct() function
293config ARCH_TASK_STRUCT_ALLOCATOR
294 bool
295
Kees Cook59054292017-08-16 13:00:58 -0700296config HAVE_ARCH_THREAD_STRUCT_WHITELIST
297 bool
298 depends on !ARCH_TASK_STRUCT_ALLOCATOR
299 help
300 An architecture should select this to provide hardened usercopy
301 knowledge about what region of the thread_struct should be
302 whitelisted for copying to userspace. Normally this is only the
303 FPU registers. Specifically, arch_thread_struct_whitelist()
304 should be implemented. Without this, the entire thread_struct
305 field in task_struct will be left whitelisted.
306
Linus Torvaldsb235bee2016-06-24 15:09:37 -0700307# Select if arch has its private alloc_thread_stack() function
308config ARCH_THREAD_STACK_ALLOCATOR
Thomas Gleixnerf5e10282012-05-05 15:05:48 +0000309 bool
310
Ingo Molnar5aaeb5c2015-07-17 12:28:12 +0200311# Select if arch wants to size task_struct dynamically via arch_task_struct_size:
312config ARCH_WANTS_DYNAMIC_TASK_STRUCT
313 bool
314
Nick Desaulniers51c2ee62021-06-21 16:18:22 -0700315config ARCH_WANTS_NO_INSTR
316 bool
317 help
318 An architecture should select this if the noinstr macro is being used on
319 functions to denote that the toolchain should avoid instrumenting such
320 functions and is required for correctness.
321
Yury Norov942fa982018-05-16 11:18:49 +0300322config ARCH_32BIT_OFF_T
323 bool
324 depends on !64BIT
325 help
326 All new 32-bit architectures should have 64-bit off_t type on
327 userspace side which corresponds to the loff_t kernel type. This
328 is the requirement for modern ABIs. Some existing architectures
329 still support 32-bit off_t. This option is enabled for all such
330 architectures explicitly.
331
Heiko Carstens96c0a6a2021-02-10 21:51:02 +0100332# Selected by 64 bit architectures which have a 32 bit f_tinode in struct ustat
333config ARCH_32BIT_USTAT_F_TINODE
334 bool
335
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900336config HAVE_ASM_MODVERSIONS
337 bool
338 help
Colin Ian Kinga86ecfa2020-12-14 19:03:44 -0800339 This symbol should be selected by an architecture if it provides
Masahiro Yamada2ff2b7e2019-08-19 14:54:20 +0900340 <asm/asm-prototypes.h> to support the module versioning for symbols
341 exported from assembly code.
342
Heiko Carstensf850c30c2010-02-10 17:25:17 +0100343config HAVE_REGS_AND_STACK_ACCESS_API
344 bool
Heiko Carstense01292b2010-02-18 14:25:21 +0100345 help
Colin Ian Kinga86ecfa2020-12-14 19:03:44 -0800346 This symbol should be selected by an architecture if it supports
Heiko Carstense01292b2010-02-18 14:25:21 +0100347 the API needed to access registers and stack entries from pt_regs,
348 declared in asm/ptrace.h
349 For example the kprobes-based event tracer needs this API.
Heiko Carstensf850c30c2010-02-10 17:25:17 +0100350
Mathieu Desnoyersd7822b12018-06-02 08:43:54 -0400351config HAVE_RSEQ
352 bool
353 depends on HAVE_REGS_AND_STACK_ACCESS_API
354 help
355 This symbol should be selected by an architecture if it
356 supports an implementation of restartable sequences.
357
Miguel Ojeda2f7ab122021-07-03 16:42:57 +0200358config HAVE_RUST
359 bool
360 help
361 This symbol should be selected by an architecture if it
362 supports Rust.
363
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900364config HAVE_FUNCTION_ARG_ACCESS_API
365 bool
366 help
Colin Ian Kinga86ecfa2020-12-14 19:03:44 -0800367 This symbol should be selected by an architecture if it supports
Masami Hiramatsu3c88ee194c2018-04-25 21:20:57 +0900368 the API needed to access function arguments from pt_regs,
369 declared in asm/ptrace.h
370
K.Prasad62a038d2009-06-01 23:43:33 +0530371config HAVE_HW_BREAKPOINT
372 bool
Frederic Weisbecker99e8c5a2009-12-17 01:33:54 +0100373 depends on PERF_EVENTS
K.Prasad62a038d2009-06-01 23:43:33 +0530374
Frederic Weisbecker01027522010-04-11 18:55:56 +0200375config HAVE_MIXED_BREAKPOINTS_REGS
376 bool
377 depends on HAVE_HW_BREAKPOINT
378 help
379 Depending on the arch implementation of hardware breakpoints,
380 some of them have separate registers for data and instruction
381 breakpoints addresses, others have mixed registers to store
382 them but define the access type in a control register.
383 Select this option if your arch implements breakpoints under the
384 latter fashion.
385
Avi Kivity7c68af62009-09-19 09:40:22 +0300386config HAVE_USER_RETURN_NOTIFIER
387 bool
Ingo Molnara1922ed2009-09-07 08:19:51 +0200388
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200389config HAVE_PERF_EVENTS_NMI
390 bool
Frederic Weisbecker23637d42010-05-15 23:15:20 +0200391 help
392 System hardware can generate an NMI using the perf event
393 subsystem. Also has support for calculating CPU cycle events
394 to determine how many clock cycles in a given period.
Frederic Weisbeckerc01d4322010-05-15 22:57:48 +0200395
Nicholas Piggin05a4a952017-07-12 14:35:46 -0700396config HAVE_HARDLOCKUP_DETECTOR_PERF
397 bool
398 depends on HAVE_PERF_EVENTS_NMI
399 help
400 The arch chooses to use the generic perf-NMI-based hardlockup
401 detector. Must define HAVE_PERF_EVENTS_NMI.
402
403config HAVE_NMI_WATCHDOG
404 depends on HAVE_NMI
405 bool
406 help
407 The arch provides a low level NMI watchdog. It provides
408 asm/nmi.h, and defines its own arch_touch_nmi_watchdog().
409
410config HAVE_HARDLOCKUP_DETECTOR_ARCH
411 bool
412 select HAVE_NMI_WATCHDOG
413 help
414 The arch chooses to provide its own hardlockup detector, which is
415 a superset of the HAVE_NMI_WATCHDOG. It also conforms to config
416 interfaces and parameters provided by hardlockup detector subsystem.
417
Jiri Olsac5e63192012-08-07 15:20:36 +0200418config HAVE_PERF_REGS
419 bool
420 help
421 Support selective register dumps for perf events. This includes
422 bit-mapping of each registers and a unique architecture id.
423
Jiri Olsac5ebced2012-08-07 15:20:40 +0200424config HAVE_PERF_USER_STACK_DUMP
425 bool
426 help
427 Support user stack dumps for perf event samples. This needs
428 access to the user stack pointer which is not unified across
429 architectures.
430
Jason Baronbf5438fc2010-09-17 11:09:00 -0400431config HAVE_ARCH_JUMP_LABEL
432 bool
433
Ard Biesheuvel50ff18a2018-09-18 23:51:37 -0700434config HAVE_ARCH_JUMP_LABEL_RELATIVE
435 bool
436
Peter Zijlstra0d6e24d2020-02-03 17:37:11 -0800437config MMU_GATHER_TABLE_FREE
438 bool
439
Peter Zijlstraff2e6d722020-02-03 17:37:02 -0800440config MMU_GATHER_RCU_TABLE_FREE
Peter Zijlstra26723912011-05-24 17:12:00 -0700441 bool
Peter Zijlstra0d6e24d2020-02-03 17:37:11 -0800442 select MMU_GATHER_TABLE_FREE
Peter Zijlstra26723912011-05-24 17:12:00 -0700443
Peter Zijlstra3af4bd02020-02-03 17:37:05 -0800444config MMU_GATHER_PAGE_SIZE
Peter Zijlstraed6a7932018-08-31 14:46:08 +0200445 bool
446
Peter Zijlstra27796d032020-02-03 17:36:59 -0800447config MMU_GATHER_NO_RANGE
448 bool
Peter Zijlstra1e9fdf22022-07-08 09:18:03 +0200449 select MMU_GATHER_MERGE_VMAS
450
451config MMU_GATHER_NO_FLUSH_CACHE
452 bool
453
454config MMU_GATHER_MERGE_VMAS
455 bool
Peter Zijlstra27796d032020-02-03 17:36:59 -0800456
Peter Zijlstra580a5862020-02-03 17:37:08 -0800457config MMU_GATHER_NO_GATHER
Martin Schwidefsky952a31c2018-09-18 14:51:50 +0200458 bool
Peter Zijlstra0d6e24d2020-02-03 17:37:11 -0800459 depends on MMU_GATHER_TABLE_FREE
Martin Schwidefsky952a31c2018-09-18 14:51:50 +0200460
Nicholas Piggind53c3df2020-09-14 14:52:16 +1000461config ARCH_WANT_IRQS_OFF_ACTIVATE_MM
462 bool
463 help
464 Temporary select until all architectures can be converted to have
465 irqs disabled over activate_mm. Architectures that do IPI based TLB
466 shootdowns should enable this.
467
Huang Yingdf013ff2011-07-13 13:14:22 +0800468config ARCH_HAVE_NMI_SAFE_CMPXCHG
469 bool
470
Heiko Carstens43570fd2012-01-12 17:17:27 -0800471config HAVE_ALIGNED_STRUCT_PAGE
472 bool
473 help
474 This makes sure that struct pages are double word aligned and that
475 e.g. the SLUB allocator can perform double word atomic operations
476 on a struct page for better performance. However selecting this
477 might increase the size of a struct page by a word.
478
Heiko Carstens41561532012-01-12 17:17:30 -0800479config HAVE_CMPXCHG_LOCAL
480 bool
481
Heiko Carstens25654092012-01-12 17:17:33 -0800482config HAVE_CMPXCHG_DOUBLE
483 bool
484
Paul E. McKenney77e58492017-01-14 13:32:50 -0800485config ARCH_WEAK_RELEASE_ACQUIRE
486 bool
487
Will Deaconc1d7e012012-07-30 14:42:46 -0700488config ARCH_WANT_IPC_PARSE_VERSION
489 bool
490
491config ARCH_WANT_COMPAT_IPC_PARSE_VERSION
492 bool
493
Chris Metcalf48b25c42012-03-15 13:13:38 -0400494config ARCH_WANT_OLD_COMPAT_IPC
Will Deaconc1d7e012012-07-30 14:42:46 -0700495 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
Chris Metcalf48b25c42012-03-15 13:13:38 -0400496 bool
497
YiFei Zhu282a1812020-09-24 07:44:16 -0500498config HAVE_ARCH_SECCOMP
Will Drewrye2cfabdf2012-04-12 16:47:57 -0500499 bool
500 help
YiFei Zhu282a1812020-09-24 07:44:16 -0500501 An arch should select this symbol to support seccomp mode 1 (the fixed
502 syscall policy), and must provide an overrides for __NR_seccomp_sigreturn,
503 and compat syscalls if the asm-generic/seccomp.h defaults need adjustment:
504 - __NR_seccomp_read_32
505 - __NR_seccomp_write_32
506 - __NR_seccomp_exit_32
507 - __NR_seccomp_sigreturn_32
508
509config HAVE_ARCH_SECCOMP_FILTER
510 bool
511 select HAVE_ARCH_SECCOMP
512 help
Will Drewryfb0fadf2012-04-12 16:48:02 -0500513 An arch should select this symbol if it provides all of these things:
YiFei Zhu282a1812020-09-24 07:44:16 -0500514 - all the requirements for HAVE_ARCH_SECCOMP
Will Drewrybb6ea432012-04-12 16:48:01 -0500515 - syscall_get_arch()
516 - syscall_get_arguments()
517 - syscall_rollback()
518 - syscall_set_return_value()
Will Drewryfb0fadf2012-04-12 16:48:02 -0500519 - SIGSYS siginfo_t support
520 - secure_computing is called from a ptrace_event()-safe context
521 - secure_computing return value is checked and a return value of -1
522 results in the system call being skipped immediately.
Kees Cook48dc92b2014-06-25 16:08:24 -0700523 - seccomp syscall wired up
YiFei Zhu0d8315d2020-11-11 07:33:54 -0600524 - if !HAVE_SPARSE_SYSCALL_NR, have SECCOMP_ARCH_NATIVE,
525 SECCOMP_ARCH_NATIVE_NR, SECCOMP_ARCH_NATIVE_NAME defined. If
526 COMPAT is supported, have the SECCOMP_ARCH_COMPAT* defines too.
Will Drewrye2cfabdf2012-04-12 16:47:57 -0500527
YiFei Zhu282a1812020-09-24 07:44:16 -0500528config SECCOMP
529 prompt "Enable seccomp to safely execute untrusted bytecode"
530 def_bool y
531 depends on HAVE_ARCH_SECCOMP
532 help
533 This kernel feature is useful for number crunching applications
534 that may need to handle untrusted bytecode during their
535 execution. By using pipes or other transports made available
536 to the process as file descriptors supporting the read/write
537 syscalls, it's possible to isolate those applications in their
538 own address space using seccomp. Once seccomp is enabled via
539 prctl(PR_SET_SECCOMP) or the seccomp() syscall, it cannot be
540 disabled and the task is only allowed to execute a few safe
541 syscalls defined by each seccomp mode.
542
543 If unsure, say Y.
544
Will Drewrye2cfabdf2012-04-12 16:47:57 -0500545config SECCOMP_FILTER
546 def_bool y
547 depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET
548 help
549 Enable tasks to build secure computing environments defined
550 in terms of Berkeley Packet Filter programs which implement
551 task-defined system call filtering polices.
552
Mauro Carvalho Chehab5fb94e92018-05-08 15:14:57 -0300553 See Documentation/userspace-api/seccomp_filter.rst for details.
Will Drewrye2cfabdf2012-04-12 16:47:57 -0500554
YiFei Zhu0d8315d2020-11-11 07:33:54 -0600555config SECCOMP_CACHE_DEBUG
556 bool "Show seccomp filter cache status in /proc/pid/seccomp_cache"
557 depends on SECCOMP_FILTER && !HAVE_SPARSE_SYSCALL_NR
558 depends on PROC_FS
559 help
560 This enables the /proc/pid/seccomp_cache interface to monitor
561 seccomp cache data. The file format is subject to change. Reading
562 the file requires CAP_SYS_ADMIN.
563
564 This option is for debugging only. Enabling presents the risk that
565 an adversary may be able to infer the seccomp filter logic.
566
567 If unsure, say N.
568
Alexander Popovafaef012018-08-17 01:16:58 +0300569config HAVE_ARCH_STACKLEAK
570 bool
571 help
572 An architecture should select this if it has the code which
573 fills the used part of the kernel stack with the STACKLEAK_POISON
574 value before returning from system calls.
575
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900576config HAVE_STACKPROTECTOR
Kees Cook19952a92013-12-19 11:35:58 -0800577 bool
578 help
579 An arch should select this symbol if:
Kees Cook19952a92013-12-19 11:35:58 -0800580 - it has implemented a stack canary (e.g. __stack_chk_guard)
581
Linus Torvalds050e9ba2018-06-14 12:21:18 +0900582config STACKPROTECTOR
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900583 bool "Stack Protector buffer overflow detection"
Masahiro Yamadad148eac2018-06-14 19:36:45 +0900584 depends on HAVE_STACKPROTECTOR
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900585 depends on $(cc-option,-fstack-protector)
586 default y
Kees Cook87796572013-12-19 11:35:59 -0800587 help
588 This option turns on the "stack-protector" GCC feature. This
Kees Cook19952a92013-12-19 11:35:58 -0800589 feature puts, at the beginning of functions, a canary value on
590 the stack just before the return address, and validates
591 the value just before actually returning. Stack based buffer
592 overflows (that need to overwrite this return address) now also
593 overwrite the canary, which gets detected and the attack is then
594 neutralized via a kernel panic.
595
Kees Cook87796572013-12-19 11:35:59 -0800596 Functions will have the stack-protector canary logic added if they
597 have an 8-byte or larger character array on the stack.
598
Kees Cook19952a92013-12-19 11:35:58 -0800599 This feature requires gcc version 4.2 or above, or a distribution
Kees Cook87796572013-12-19 11:35:59 -0800600 gcc with the feature backported ("-fstack-protector").
601
602 On an x86 "defconfig" build, this feature adds canary checks to
603 about 3% of all kernel functions, which increases kernel code size
604 by about 0.3%.
605
Linus Torvalds050e9ba2018-06-14 12:21:18 +0900606config STACKPROTECTOR_STRONG
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900607 bool "Strong Stack Protector"
Linus Torvalds050e9ba2018-06-14 12:21:18 +0900608 depends on STACKPROTECTOR
Masahiro Yamada2a61f472018-05-28 18:22:00 +0900609 depends on $(cc-option,-fstack-protector-strong)
610 default y
Kees Cook87796572013-12-19 11:35:59 -0800611 help
612 Functions will have the stack-protector canary logic added in any
613 of the following conditions:
614
615 - local variable's address used as part of the right hand side of an
616 assignment or function argument
617 - local variable is an array (or union containing an array),
618 regardless of array type or length
619 - uses register local variables
620
621 This feature requires gcc version 4.9 or above, or a distribution
622 gcc with the feature backported ("-fstack-protector-strong").
623
624 On an x86 "defconfig" build, this feature adds canary checks to
625 about 20% of all kernel functions, which increases the kernel code
626 size by about 2%.
627
Sami Tolvanend08b9f02020-04-27 09:00:07 -0700628config ARCH_SUPPORTS_SHADOW_CALL_STACK
629 bool
630 help
Dan Liafcf5442022-03-02 23:43:23 -0800631 An architecture should select this if it supports the compiler's
632 Shadow Call Stack and implements runtime support for shadow stack
Will Deaconaa7a65a2020-05-15 16:15:46 +0100633 switching.
Sami Tolvanend08b9f02020-04-27 09:00:07 -0700634
635config SHADOW_CALL_STACK
Dan Liafcf5442022-03-02 23:43:23 -0800636 bool "Shadow Call Stack"
637 depends on ARCH_SUPPORTS_SHADOW_CALL_STACK
Sami Tolvanenddc98632020-04-27 09:00:10 -0700638 depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER
Sami Tolvanend08b9f02020-04-27 09:00:07 -0700639 help
Dan Liafcf5442022-03-02 23:43:23 -0800640 This option enables the compiler's Shadow Call Stack, which
641 uses a shadow stack to protect function return addresses from
642 being overwritten by an attacker. More information can be found
643 in the compiler's documentation:
Sami Tolvanend08b9f02020-04-27 09:00:07 -0700644
Dan Liafcf5442022-03-02 23:43:23 -0800645 - Clang: https://clang.llvm.org/docs/ShadowCallStack.html
646 - GCC: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options
Sami Tolvanend08b9f02020-04-27 09:00:07 -0700647
648 Note that security guarantees in the kernel differ from the
649 ones documented for user space. The kernel must store addresses
650 of shadow stacks in memory, which means an attacker capable of
651 reading and writing arbitrary memory may be able to locate them
652 and hijack control flow by modifying the stacks.
653
Sami Tolvanendc5723b2020-12-11 10:46:19 -0800654config LTO
655 bool
656 help
657 Selected if the kernel will be built using the compiler's LTO feature.
658
659config LTO_CLANG
660 bool
661 select LTO
662 help
663 Selected if the kernel will be built using Clang's LTO feature.
664
665config ARCH_SUPPORTS_LTO_CLANG
666 bool
667 help
668 An architecture should select this option if it supports:
669 - compiling with Clang,
670 - compiling inline assembly with Clang's integrated assembler,
671 - and linking with LLD.
672
673config ARCH_SUPPORTS_LTO_CLANG_THIN
674 bool
675 help
676 An architecture should select this option if it can support Clang's
677 ThinLTO mode.
678
679config HAS_LTO_CLANG
680 def_bool y
Nathan Chancellor1e68a8af2021-11-29 09:58:00 -0700681 depends on CC_IS_CLANG && LD_IS_LLD && AS_IS_LLVM
Sami Tolvanendc5723b2020-12-11 10:46:19 -0800682 depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm)
683 depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
684 depends on ARCH_SUPPORTS_LTO_CLANG
685 depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT
Sami Tolvanenbf3c2552021-03-08 10:46:56 -0800686 depends on !KASAN || KASAN_HW_TAGS
Sami Tolvanendc5723b2020-12-11 10:46:19 -0800687 depends on !GCOV_KERNEL
Sami Tolvanendc5723b2020-12-11 10:46:19 -0800688 help
689 The compiler and Kconfig options support building with Clang's
690 LTO.
691
692choice
693 prompt "Link Time Optimization (LTO)"
694 default LTO_NONE
695 help
696 This option enables Link Time Optimization (LTO), which allows the
697 compiler to optimize binaries globally.
698
699 If unsure, select LTO_NONE. Note that LTO is very resource-intensive
700 so it's disabled by default.
701
702config LTO_NONE
703 bool "None"
704 help
705 Build the kernel normally, without Link Time Optimization (LTO).
706
707config LTO_CLANG_FULL
708 bool "Clang Full LTO (EXPERIMENTAL)"
709 depends on HAS_LTO_CLANG
710 depends on !COMPILE_TEST
711 select LTO_CLANG
712 help
713 This option enables Clang's full Link Time Optimization (LTO), which
714 allows the compiler to optimize the kernel globally. If you enable
715 this option, the compiler generates LLVM bitcode instead of ELF
716 object files, and the actual compilation from bitcode happens at
717 the LTO link step, which may take several minutes depending on the
718 kernel configuration. More information can be found from LLVM's
719 documentation:
720
721 https://llvm.org/docs/LinkTimeOptimization.html
722
723 During link time, this option can use a large amount of RAM, and
724 may take much longer than the ThinLTO option.
725
726config LTO_CLANG_THIN
727 bool "Clang ThinLTO (EXPERIMENTAL)"
728 depends on HAS_LTO_CLANG && ARCH_SUPPORTS_LTO_CLANG_THIN
729 select LTO_CLANG
730 help
731 This option enables Clang's ThinLTO, which allows for parallel
732 optimization and faster incremental compiles compared to the
733 CONFIG_LTO_CLANG_FULL option. More information can be found
734 from Clang's documentation:
735
736 https://clang.llvm.org/docs/ThinLTO.html
737
738 If unsure, say Y.
739endchoice
740
Sami Tolvanencf68fff2021-04-08 11:28:26 -0700741config ARCH_SUPPORTS_CFI_CLANG
742 bool
743 help
744 An architecture should select this option if it can support Clang's
745 Control-Flow Integrity (CFI) checking.
746
Sami Tolvanen89245602022-09-08 14:54:47 -0700747config ARCH_USES_CFI_TRAPS
748 bool
749
Sami Tolvanencf68fff2021-04-08 11:28:26 -0700750config CFI_CLANG
751 bool "Use Clang's Control Flow Integrity (CFI)"
Sami Tolvanen89245602022-09-08 14:54:47 -0700752 depends on ARCH_SUPPORTS_CFI_CLANG
753 depends on $(cc-option,-fsanitize=kcfi)
Sami Tolvanencf68fff2021-04-08 11:28:26 -0700754 help
755 This option enables Clang’s forward-edge Control Flow Integrity
756 (CFI) checking, where the compiler injects a runtime check to each
757 indirect function call to ensure the target is a valid function with
758 the correct static type. This restricts possible call targets and
759 makes it more difficult for an attacker to exploit bugs that allow
760 the modification of stored function pointers. More information can be
761 found from Clang's documentation:
762
763 https://clang.llvm.org/docs/ControlFlowIntegrity.html
764
Sami Tolvanencf68fff2021-04-08 11:28:26 -0700765config CFI_PERMISSIVE
766 bool "Use CFI in permissive mode"
767 depends on CFI_CLANG
768 help
769 When selected, Control Flow Integrity (CFI) violations result in a
770 warning instead of a kernel panic. This option should only be used
771 for finding indirect call type mismatches during development.
772
773 If unsure, say N.
774
Kees Cook0f60a8e2016-07-12 16:19:48 -0700775config HAVE_ARCH_WITHIN_STACK_FRAMES
776 bool
777 help
778 An architecture should select this if it can walk the kernel stack
779 frames to determine if an object is part of either the arguments
780 or local variables (i.e. that it excludes saved return addresses,
781 and similar) by implementing an inline arch_within_stack_frames(),
782 which is used by CONFIG_HARDENED_USERCOPY.
783
Frederic Weisbecker24a9c5412022-06-08 16:40:24 +0200784config HAVE_CONTEXT_TRACKING_USER
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200785 bool
786 help
Frederic Weisbecker91d1aa432012-11-27 19:33:25 +0100787 Provide kernel/user boundaries probes necessary for subsystems
788 that need it, such as userspace RCU extended quiescent state.
Frederic Weisbecker490f5612020-01-27 16:41:52 +0100789 Syscalls need to be wrapped inside user_exit()-user_enter(), either
790 optimized behind static key or through the slow path using TIF_NOHZ
791 flag. Exceptions handlers must be wrapped as well. Irqs are already
Frederic Weisbecker6f0e6c12022-06-08 16:40:26 +0200792 protected inside ct_irq_enter/ct_irq_exit() but preemption or signal
Frederic Weisbecker490f5612020-01-27 16:41:52 +0100793 handling on irq exit still need to be protected.
794
Frederic Weisbecker24a9c5412022-06-08 16:40:24 +0200795config HAVE_CONTEXT_TRACKING_USER_OFFSTACK
Frederic Weisbecker83c2da22020-11-17 16:16:33 +0100796 bool
797 help
798 Architecture neither relies on exception_enter()/exception_exit()
799 nor on schedule_user(). Also preempt_schedule_notrace() and
800 preempt_schedule_irq() can't be called in a preemptible section
801 while context tracking is CONTEXT_USER. This feature reflects a sane
802 entry implementation where the following requirements are met on
803 critical entry code, ie: before user_exit() or after user_enter():
804
805 - Critical entry code isn't preemptible (or better yet:
806 not interruptible).
Frederic Weisbecker493c1822022-06-08 16:40:27 +0200807 - No use of RCU read side critical sections, unless ct_nmi_enter()
Frederic Weisbecker83c2da22020-11-17 16:16:33 +0100808 got called.
809 - No use of instrumentation, unless instrumentation_begin() got
810 called.
811
Frederic Weisbecker490f5612020-01-27 16:41:52 +0100812config HAVE_TIF_NOHZ
813 bool
814 help
815 Arch relies on TIF_NOHZ and syscall slow path to implement context
816 tracking calls to user_enter()/user_exit().
Frederic Weisbecker2b1d5022012-07-11 20:26:30 +0200817
Frederic Weisbeckerb9527412012-06-16 15:39:34 +0200818config HAVE_VIRT_CPU_ACCOUNTING
819 bool
820
Frederic Weisbecker2b91ec9f2020-12-02 12:57:29 +0100821config HAVE_VIRT_CPU_ACCOUNTING_IDLE
822 bool
823 help
824 Architecture has its own way to account idle CPU time and therefore
825 doesn't implement vtime_account_idle().
826
Stanislaw Gruszka40565b52016-11-15 03:06:51 +0100827config ARCH_HAS_SCALED_CPUTIME
828 bool
829
Kevin Hilman554b0002013-09-16 15:28:21 -0700830config HAVE_VIRT_CPU_ACCOUNTING_GEN
831 bool
832 default y if 64BIT
833 help
834 With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit.
835 Before enabling this option, arch code must be audited
836 to ensure there are no races in concurrent read/write of
837 cputime_t. For example, reading/writing 64-bit cputime_t on
838 some 32-bit arches may require multiple accesses, so proper
839 locking is needed to protect against concurrent accesses.
840
Frederic Weisbeckerfdf9c352012-09-09 14:56:31 +0200841config HAVE_IRQ_TIME_ACCOUNTING
842 bool
843 help
844 Archs need to ensure they use a high enough resolution clock to
845 support irq time accounting and then call enable_sched_clock_irqtime().
846
Kalesh Singhc49dd342020-12-14 19:07:30 -0800847config HAVE_MOVE_PUD
848 bool
849 help
850 Architectures that select this are able to move page tables at the
851 PUD level. If there are only 3 page table levels, the move effectively
852 happens at the PGD level.
853
Joel Fernandes (Google)2c91bd4a2019-01-03 15:28:38 -0800854config HAVE_MOVE_PMD
855 bool
856 help
857 Archs that select this are able to move page tables at the PMD level.
858
Gerald Schaefer15626062012-10-08 16:30:04 -0700859config HAVE_ARCH_TRANSPARENT_HUGEPAGE
860 bool
861
Matthew Wilcoxa00cc7d2017-02-24 14:57:02 -0800862config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
863 bool
864
Toshi Kani0ddab1d2015-04-14 15:47:20 -0700865config HAVE_ARCH_HUGE_VMAP
866 bool
867
Nicholas Piggin121e6f32021-04-29 22:58:49 -0700868#
869# Archs that select this would be capable of PMD-sized vmaps (i.e.,
Song Liu559089e2022-04-15 09:44:10 -0700870# arch_vmap_pmd_supported() returns true). The VM_ALLOW_HUGE_VMAP flag
871# must be used to enable allocations to use hugepages.
Nicholas Piggin121e6f32021-04-29 22:58:49 -0700872#
873config HAVE_ARCH_HUGE_VMALLOC
874 depends on HAVE_ARCH_HUGE_VMAP
875 bool
876
Alexandre Ghiti3876d4a2019-06-27 15:00:11 -0700877config ARCH_WANT_HUGE_PMD_SHARE
878 bool
879
Pavel Emelyanov0f8975e2013-07-03 15:01:20 -0700880config HAVE_ARCH_SOFT_DIRTY
881 bool
882
David Howells786d35d2012-09-28 14:31:03 +0930883config HAVE_MOD_ARCH_SPECIFIC
884 bool
885 help
886 The arch uses struct mod_arch_specific to store data. Many arches
887 just need a simple module loader without arch specific data - those
888 should not enable this.
889
890config MODULES_USE_ELF_RELA
891 bool
892 help
893 Modules only use ELF RELA relocations. Modules with ELF REL
894 relocations will give an error.
895
896config MODULES_USE_ELF_REL
897 bool
898 help
899 Modules only use ELF REL relocations. Modules with ELF RELA
900 relocations will give an error.
901
Christophe Leroy01dc0382022-02-23 13:02:14 +0100902config ARCH_WANTS_MODULES_DATA_IN_VMALLOC
903 bool
904 help
905 For architectures like powerpc/32 which have constraints on module
906 allocation and need to allocate module data outside of module area.
907
Frederic Weisbeckercc1f0272013-09-24 17:17:47 +0200908config HAVE_IRQ_EXIT_ON_IRQ_STACK
909 bool
910 help
911 Architecture doesn't only execute the irq handler on the irq stack
912 but also irq_exit(). This way we can process softirqs on this irq
913 stack instead of switching to a new one when we call __do_softirq()
914 in the end of an hardirq.
915 This spares a stack switch and improves cache usage on softirq
916 processing.
917
Thomas Gleixnercd1a41c2021-02-10 00:40:52 +0100918config HAVE_SOFTIRQ_ON_OWN_STACK
919 bool
920 help
921 Architecture provides a function to run __do_softirq() on a
Colin Ian Kingc226bc32021-09-07 19:57:38 -0700922 separate stack.
Thomas Gleixnercd1a41c2021-02-10 00:40:52 +0100923
Sebastian Andrzej Siewior8cbb2b52022-08-25 10:25:05 +0200924config SOFTIRQ_ON_OWN_STACK
925 def_bool HAVE_SOFTIRQ_ON_OWN_STACK && !PREEMPT_RT
926
Arnd Bergmann12700c12022-02-15 17:55:04 +0100927config ALTERNATE_USER_ADDRESS_SPACE
928 bool
929 help
930 Architectures set this when the CPU uses separate address
931 spaces for kernel and user space pointers. In this case, the
932 access_ok() check on a __user pointer is skipped.
933
Kirill A. Shutemov235a8f02015-04-14 15:46:17 -0700934config PGTABLE_LEVELS
935 int
936 default 2
937
Kees Cook2b68f6c2015-04-14 15:48:00 -0700938config ARCH_HAS_ELF_RANDOMIZE
939 bool
940 help
941 An architecture supports choosing randomized locations for
942 stack, mmap, brk, and ET_DYN. Defined functions:
943 - arch_mmap_rnd()
Kees Cook204db6e2015-04-14 15:48:12 -0700944 - arch_randomize_brk()
Kees Cook2b68f6c2015-04-14 15:48:00 -0700945
Daniel Cashmand07e2252016-01-14 15:19:53 -0800946config HAVE_ARCH_MMAP_RND_BITS
947 bool
948 help
949 An arch should select this symbol if it supports setting a variable
950 number of bits for use in establishing the base address for mmap
951 allocations, has MMU enabled and provides values for both:
952 - ARCH_MMAP_RND_BITS_MIN
953 - ARCH_MMAP_RND_BITS_MAX
954
Jiri Slaby5f56a5d2016-05-20 17:00:16 -0700955config HAVE_EXIT_THREAD
956 bool
957 help
958 An architecture implements exit_thread.
959
Daniel Cashmand07e2252016-01-14 15:19:53 -0800960config ARCH_MMAP_RND_BITS_MIN
961 int
962
963config ARCH_MMAP_RND_BITS_MAX
964 int
965
966config ARCH_MMAP_RND_BITS_DEFAULT
967 int
968
969config ARCH_MMAP_RND_BITS
970 int "Number of bits to use for ASLR of mmap base address" if EXPERT
971 range ARCH_MMAP_RND_BITS_MIN ARCH_MMAP_RND_BITS_MAX
972 default ARCH_MMAP_RND_BITS_DEFAULT if ARCH_MMAP_RND_BITS_DEFAULT
973 default ARCH_MMAP_RND_BITS_MIN
974 depends on HAVE_ARCH_MMAP_RND_BITS
975 help
976 This value can be used to select the number of bits to use to
977 determine the random offset to the base address of vma regions
978 resulting from mmap allocations. This value will be bounded
979 by the architecture's minimum and maximum supported values.
980
981 This value can be changed after boot using the
982 /proc/sys/vm/mmap_rnd_bits tunable
983
984config HAVE_ARCH_MMAP_RND_COMPAT_BITS
985 bool
986 help
987 An arch should select this symbol if it supports running applications
988 in compatibility mode, supports setting a variable number of bits for
989 use in establishing the base address for mmap allocations, has MMU
990 enabled and provides values for both:
991 - ARCH_MMAP_RND_COMPAT_BITS_MIN
992 - ARCH_MMAP_RND_COMPAT_BITS_MAX
993
994config ARCH_MMAP_RND_COMPAT_BITS_MIN
995 int
996
997config ARCH_MMAP_RND_COMPAT_BITS_MAX
998 int
999
1000config ARCH_MMAP_RND_COMPAT_BITS_DEFAULT
1001 int
1002
1003config ARCH_MMAP_RND_COMPAT_BITS
1004 int "Number of bits to use for ASLR of mmap base address for compatible applications" if EXPERT
1005 range ARCH_MMAP_RND_COMPAT_BITS_MIN ARCH_MMAP_RND_COMPAT_BITS_MAX
1006 default ARCH_MMAP_RND_COMPAT_BITS_DEFAULT if ARCH_MMAP_RND_COMPAT_BITS_DEFAULT
1007 default ARCH_MMAP_RND_COMPAT_BITS_MIN
1008 depends on HAVE_ARCH_MMAP_RND_COMPAT_BITS
1009 help
1010 This value can be used to select the number of bits to use to
1011 determine the random offset to the base address of vma regions
1012 resulting from mmap allocations for compatible applications This
1013 value will be bounded by the architecture's minimum and maximum
1014 supported values.
1015
1016 This value can be changed after boot using the
1017 /proc/sys/vm/mmap_rnd_compat_bits tunable
1018
Dmitry Safonov1b028f72017-03-06 17:17:19 +03001019config HAVE_ARCH_COMPAT_MMAP_BASES
1020 bool
1021 help
1022 This allows 64bit applications to invoke 32-bit mmap() syscall
1023 and vice-versa 32-bit applications to call 64-bit mmap().
1024 Required for applications doing different bitness syscalls.
1025
Guenter Roeck1f0e2902021-11-27 07:44:40 -08001026config PAGE_SIZE_LESS_THAN_64KB
1027 def_bool y
1028 depends on !ARM64_64K_PAGES
1029 depends on !IA64_PAGE_SIZE_64KB
1030 depends on !PAGE_SIZE_64KB
1031 depends on !PARISC_PAGE_SIZE_64KB
Nathan Chancellore4bbd202022-01-19 18:10:22 -08001032 depends on PAGE_SIZE_LESS_THAN_256KB
1033
1034config PAGE_SIZE_LESS_THAN_256KB
1035 def_bool y
Guenter Roeck1f0e2902021-11-27 07:44:40 -08001036 depends on !PAGE_SIZE_256KB
1037
Alexandre Ghiti67f39772019-09-23 15:38:47 -07001038# This allows to use a set of generic functions to determine mmap base
1039# address by giving priority to top-down scheme only if the process
1040# is not in legacy mode (compat task, unlimited stack size or
1041# sysctl_legacy_va_layout).
1042# Architecture that selects this option can provide its own version of:
1043# - STACK_RND_MASK
1044config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
1045 bool
1046 depends on MMU
Alexandre Ghitie7142bf2019-09-23 15:38:50 -07001047 select ARCH_HAS_ELF_RANDOMIZE
Alexandre Ghiti67f39772019-09-23 15:38:47 -07001048
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -07001049config HAVE_OBJTOOL
1050 bool
1051
Josh Poimboeuf4ab76742022-04-18 09:50:39 -07001052config HAVE_JUMP_LABEL_HACK
1053 bool
1054
Josh Poimboeuf22102f42022-04-18 09:50:40 -07001055config HAVE_NOINSTR_HACK
1056 bool
1057
Josh Poimboeuf489e3552022-04-18 09:50:42 -07001058config HAVE_NOINSTR_VALIDATION
1059 bool
1060
Josh Poimboeuf5f3da8c2022-04-19 09:05:09 -07001061config HAVE_UACCESS_VALIDATION
1062 bool
1063 select OBJTOOL
1064
Josh Poimboeufb9ab5eb2016-02-28 22:22:42 -06001065config HAVE_STACK_VALIDATION
1066 bool
1067 help
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -07001068 Architecture supports objtool compile-time frame pointer rule
1069 validation.
Josh Poimboeufb9ab5eb2016-02-28 22:22:42 -06001070
Josh Poimboeufaf085d92017-02-13 19:42:28 -06001071config HAVE_RELIABLE_STACKTRACE
1072 bool
1073 help
Miroslav Benes140d7e82020-03-05 22:28:45 -08001074 Architecture has either save_stack_trace_tsk_reliable() or
1075 arch_stack_walk_reliable() function which only returns a stack trace
1076 if it can guarantee the trace is reliable.
Josh Poimboeufaf085d92017-02-13 19:42:28 -06001077
George Spelvin468a9422016-05-26 22:11:51 -04001078config HAVE_ARCH_HASH
1079 bool
1080 default n
1081 help
1082 If this is set, the architecture provides an <asm/hash.h>
1083 file which provides platform-specific implementations of some
1084 functions in <linux/hash.h> or fs/namei.c.
1085
Finn Thain666047fe2019-01-15 15:18:56 +11001086config HAVE_ARCH_NVRAM_OPS
1087 bool
1088
William Breathitt Gray3a495512016-05-27 18:08:27 -04001089config ISA_BUS_API
1090 def_bool ISA
1091
Al Virod2125042012-10-23 13:17:59 -04001092#
1093# ABI hall of shame
1094#
1095config CLONE_BACKWARDS
1096 bool
1097 help
1098 Architecture has tls passed as the 4th argument of clone(2),
1099 not the 5th one.
1100
1101config CLONE_BACKWARDS2
1102 bool
1103 help
1104 Architecture has the first two arguments of clone(2) swapped.
1105
Michal Simekdfa97712013-08-13 16:00:53 -07001106config CLONE_BACKWARDS3
1107 bool
1108 help
1109 Architecture has tls passed as the 3rd argument of clone(2),
1110 not the 5th one.
1111
Al Viroeaca6ea2012-11-25 23:12:10 -05001112config ODD_RT_SIGACTION
1113 bool
1114 help
1115 Architecture has unusual rt_sigaction(2) arguments
1116
Al Viro0a0e8cd2012-12-25 16:04:12 -05001117config OLD_SIGSUSPEND
1118 bool
1119 help
1120 Architecture has old sigsuspend(2) syscall, of one-argument variety
1121
1122config OLD_SIGSUSPEND3
1123 bool
1124 help
1125 Even weirder antique ABI - three-argument sigsuspend(2)
1126
Al Viro495dfbf2012-12-25 19:09:45 -05001127config OLD_SIGACTION
1128 bool
1129 help
1130 Architecture has old sigaction(2) syscall. Nope, not the same
1131 as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2),
1132 but fairly different variant of sigaction(2), thanks to OSF/1
1133 compatibility...
1134
1135config COMPAT_OLD_SIGACTION
1136 bool
1137
Deepa Dinamani17435e52018-03-13 21:03:28 -07001138config COMPAT_32BIT_TIME
Arnd Bergmann942437c2019-07-15 11:46:10 +02001139 bool "Provide system calls for 32-bit time_t"
1140 default !64BIT || COMPAT
Deepa Dinamani17435e52018-03-13 21:03:28 -07001141 help
1142 This enables 32 bit time_t support in addition to 64 bit time_t support.
1143 This is relevant on all 32-bit architectures, and 64-bit architectures
1144 as part of compat syscall handling.
1145
Christoph Hellwig87a4c372018-07-31 13:39:32 +02001146config ARCH_NO_PREEMPT
1147 bool
1148
Mickaël Salaüncb2c7d12021-04-22 17:41:17 +02001149config ARCH_EPHEMERAL_INODES
1150 def_bool n
1151 help
1152 An arch should select this symbol if it doesn't keep track of inode
1153 instances on its own, but instead relies on something else (e.g. the
1154 host kernel for an UML kernel).
1155
Thomas Gleixnera50a3f42019-07-17 22:01:49 +02001156config ARCH_SUPPORTS_RT
1157 bool
1158
Zhaoxiu Zengfff7fb02016-05-20 17:03:57 -07001159config CPU_NO_EFFICIENT_FFS
1160 def_bool n
1161
Andy Lutomirskiba14a192016-08-11 02:35:21 -07001162config HAVE_ARCH_VMAP_STACK
1163 def_bool n
1164 help
1165 An arch should select this symbol if it can support kernel stacks
1166 in vmalloc space. This means:
1167
1168 - vmalloc space must be large enough to hold many kernel stacks.
1169 This may rule out many 32-bit architectures.
1170
1171 - Stacks in vmalloc space need to work reliably. For example, if
1172 vmap page tables are created on demand, either this mechanism
1173 needs to work while the stack points to a virtual address with
1174 unpopulated page tables or arch code (switch_to() and switch_mm(),
1175 most likely) needs to ensure that the stack's page table entries
1176 are populated before running on a possibly unpopulated stack.
1177
1178 - If the stack overflows into a guard page, something reasonable
1179 should happen. The definition of "reasonable" is flexible, but
1180 instantly rebooting without logging anything would be unfriendly.
1181
1182config VMAP_STACK
1183 default y
1184 bool "Use a virtually-mapped stack"
Daniel Axtenseafb1492019-11-30 17:54:57 -08001185 depends on HAVE_ARCH_VMAP_STACK
Andrey Konovalov38dd767d2020-12-22 12:02:45 -08001186 depends on !KASAN || KASAN_HW_TAGS || KASAN_VMALLOC
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001187 help
Andy Lutomirskiba14a192016-08-11 02:35:21 -07001188 Enable this if you want the use virtually-mapped kernel stacks
1189 with guard pages. This causes kernel stack overflows to be
1190 caught immediately rather than causing difficult-to-diagnose
1191 corruption.
1192
Andrey Konovalov38dd767d2020-12-22 12:02:45 -08001193 To use this with software KASAN modes, the architecture must support
1194 backing virtual mappings with real shadow memory, and KASAN_VMALLOC
1195 must be enabled.
Andy Lutomirskiba14a192016-08-11 02:35:21 -07001196
Kees Cook39218ff2021-04-01 16:23:44 -07001197config HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
1198 def_bool n
1199 help
1200 An arch should select this symbol if it can support kernel stack
1201 offset randomization with calls to add_random_kstack_offset()
1202 during syscall entry and choose_random_kstack_offset() during
1203 syscall exit. Careful removal of -fstack-protector-strong and
1204 -fstack-protector should also be applied to the entry code and
1205 closely examined, as the artificial stack bump looks like an array
1206 to the compiler, so it will attempt to add canary checks regardless
1207 of the static branch state.
1208
Marco Elver8cb37a52022-01-31 10:05:20 +01001209config RANDOMIZE_KSTACK_OFFSET
1210 bool "Support for randomizing kernel stack offset on syscall entry" if EXPERT
1211 default y
Kees Cook39218ff2021-04-01 16:23:44 -07001212 depends on HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
Marco Elverefa90c12022-01-31 10:05:21 +01001213 depends on INIT_STACK_NONE || !CC_IS_CLANG || CLANG_VERSION >= 140000
Kees Cook39218ff2021-04-01 16:23:44 -07001214 help
1215 The kernel stack offset can be randomized (after pt_regs) by
1216 roughly 5 bits of entropy, frustrating memory corruption
1217 attacks that depend on stack address determinism or
Marco Elver8cb37a52022-01-31 10:05:20 +01001218 cross-syscall address exposures.
1219
1220 The feature is controlled via the "randomize_kstack_offset=on/off"
1221 kernel boot param, and if turned off has zero overhead due to its use
1222 of static branches (see JUMP_LABEL).
1223
1224 If unsure, say Y.
1225
1226config RANDOMIZE_KSTACK_OFFSET_DEFAULT
1227 bool "Default state of kernel stack offset randomization"
1228 depends on RANDOMIZE_KSTACK_OFFSET
1229 help
1230 Kernel stack offset randomization is controlled by kernel boot param
1231 "randomize_kstack_offset=on/off", and this config chooses the default
1232 boot state.
Kees Cook39218ff2021-04-01 16:23:44 -07001233
Laura Abbottad21fc42017-02-06 16:31:57 -08001234config ARCH_OPTIONAL_KERNEL_RWX
1235 def_bool n
1236
1237config ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
1238 def_bool n
1239
1240config ARCH_HAS_STRICT_KERNEL_RWX
1241 def_bool n
1242
Laura Abbott0f5bf6d2017-02-06 16:31:58 -08001243config STRICT_KERNEL_RWX
Laura Abbottad21fc42017-02-06 16:31:57 -08001244 bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX
1245 depends on ARCH_HAS_STRICT_KERNEL_RWX
1246 default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
1247 help
1248 If this is set, kernel text and rodata memory will be made read-only,
1249 and non-text memory will be made non-executable. This provides
1250 protection against certain security exploits (e.g. executing the heap
1251 or modifying text)
1252
1253 These features are considered standard security practice these days.
1254 You should say Y here in almost all cases.
1255
1256config ARCH_HAS_STRICT_MODULE_RWX
1257 def_bool n
1258
Laura Abbott0f5bf6d2017-02-06 16:31:58 -08001259config STRICT_MODULE_RWX
Laura Abbottad21fc42017-02-06 16:31:57 -08001260 bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX
1261 depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES
1262 default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT
1263 help
1264 If this is set, module text and rodata memory will be made read-only,
1265 and non-text memory will be made non-executable. This provides
1266 protection against certain security exploits (e.g. writing to text)
1267
Christoph Hellwigea8c64a2018-01-10 16:21:13 +01001268# select if the architecture provides an asm/dma-direct.h header
1269config ARCH_HAS_PHYS_TO_DMA
1270 bool
1271
Paul Burton04f264d2018-08-20 15:36:17 -07001272config HAVE_ARCH_COMPILER_H
1273 bool
1274 help
1275 An architecture can select this if it provides an
1276 asm/compiler.h header that should be included after
1277 linux/compiler-*.h in order to override macro definitions that those
1278 headers generally provide.
1279
Ard Biesheuvel271ca782018-08-21 21:56:00 -07001280config HAVE_ARCH_PREL32_RELOCATIONS
1281 bool
1282 help
1283 May be selected by an architecture if it supports place-relative
1284 32-bit relocations, both in the toolchain and in the module loader,
1285 in which case relative references can be used in special sections
1286 for PCI fixup, initcalls etc which are only half the size on 64 bit
1287 architectures, and don't require runtime relocation on relocatable
1288 kernels.
1289
Ard Biesheuvelce9084b2019-02-02 10:41:17 +01001290config ARCH_USE_MEMREMAP_PROT
1291 bool
1292
Waiman Longfb346fd2019-04-04 13:43:17 -04001293config LOCK_EVENT_COUNTS
1294 bool "Locking event counts collection"
1295 depends on DEBUG_FS
Masahiro Yamadaa7f7f622020-06-14 01:50:22 +09001296 help
Waiman Longfb346fd2019-04-04 13:43:17 -04001297 Enable light-weight counting of various locking related events
1298 in the system with minimal performance impact. This reduces
1299 the chance of application behavior change because of timing
1300 differences. The counts are reported via debugfs.
1301
Peter Collingbourne5cf896fb62019-07-31 18:18:42 -07001302# Select if the architecture has support for applying RELR relocations.
1303config ARCH_HAS_RELR
1304 bool
1305
1306config RELR
1307 bool "Use RELR relocation packing"
1308 depends on ARCH_HAS_RELR && TOOLS_SUPPORT_RELR
1309 default y
1310 help
1311 Store the kernel's dynamic relocations in the RELR relocation packing
1312 format. Requires a compatible linker (LLD supports this feature), as
1313 well as compatible NM and OBJCOPY utilities (llvm-nm and llvm-objcopy
1314 are compatible).
1315
Thiago Jung Bauermann0c9c1d52019-08-06 01:49:14 -03001316config ARCH_HAS_MEM_ENCRYPT
1317 bool
1318
Tom Lendacky46b49b12021-09-08 17:58:33 -05001319config ARCH_HAS_CC_PLATFORM
1320 bool
1321
Hassan Naveed0e242202019-11-15 23:44:42 +00001322config HAVE_SPARSE_SYSCALL_NR
1323 bool
1324 help
1325 An architecture should select this if its syscall numbering is sparse
1326 to save space. For example, MIPS architecture has a syscall array with
1327 entries at 4000, 5000 and 6000 locations. This option turns on syscall
1328 related optimizations for a given architecture.
1329
Sven Schnelled60d7de2020-08-04 17:01:22 +02001330config ARCH_HAS_VDSO_DATA
1331 bool
1332
Josh Poimboeuf115284d2020-08-18 15:57:41 +02001333config HAVE_STATIC_CALL
1334 bool
1335
Josh Poimboeuf9183c3f2020-08-18 15:57:42 +02001336config HAVE_STATIC_CALL_INLINE
1337 bool
1338 depends on HAVE_STATIC_CALL
Josh Poimboeuf03f16cd2022-04-18 09:50:36 -07001339 select OBJTOOL
Josh Poimboeuf9183c3f2020-08-18 15:57:42 +02001340
Michal Hocko6ef869e2021-01-18 15:12:19 +01001341config HAVE_PREEMPT_DYNAMIC
1342 bool
Mark Rutland99cf983c2022-02-14 16:52:14 +00001343
1344config HAVE_PREEMPT_DYNAMIC_CALL
1345 bool
Michal Hocko6ef869e2021-01-18 15:12:19 +01001346 depends on HAVE_STATIC_CALL
Mark Rutland99cf983c2022-02-14 16:52:14 +00001347 select HAVE_PREEMPT_DYNAMIC
Michal Hocko6ef869e2021-01-18 15:12:19 +01001348 help
Mark Rutland99cf983c2022-02-14 16:52:14 +00001349 An architecture should select this if it can handle the preemption
1350 model being selected at boot time using static calls.
1351
1352 Where an architecture selects HAVE_STATIC_CALL_INLINE, any call to a
1353 preemption function will be patched directly.
1354
1355 Where an architecture does not select HAVE_STATIC_CALL_INLINE, any
1356 call to a preemption function will go through a trampoline, and the
1357 trampoline will be patched.
1358
1359 It is strongly advised to support inline static call to avoid any
1360 overhead.
1361
1362config HAVE_PREEMPT_DYNAMIC_KEY
1363 bool
Nick Desaulniersa0a12c32022-08-19 12:06:40 -07001364 depends on HAVE_ARCH_JUMP_LABEL
Mark Rutland99cf983c2022-02-14 16:52:14 +00001365 select HAVE_PREEMPT_DYNAMIC
1366 help
1367 An architecture should select this if it can handle the preemption
1368 model being selected at boot time using static keys.
1369
1370 Each preemption function will be given an early return based on a
1371 static key. This should have slightly lower overhead than non-inline
1372 static calls, as this effectively inlines each trampoline into the
1373 start of its callee. This may avoid redundant work, and may
1374 integrate better with CFI schemes.
1375
1376 This will have greater overhead than using inline static calls as
1377 the call to the preemption function cannot be entirely elided.
Michal Hocko6ef869e2021-01-18 15:12:19 +01001378
Nathan Chancellor59612b22020-11-19 13:46:56 -07001379config ARCH_WANT_LD_ORPHAN_WARN
1380 bool
1381 help
1382 An arch should select this symbol once all linker sections are explicitly
1383 included, size-asserted, or discarded in the linker scripts. This is
1384 important because we never want expected sections to be placed heuristically
1385 by the linker, since the locations of such sections can change between linker
1386 versions.
1387
Mike Rapoport4f5b0c12020-12-14 19:09:59 -08001388config HAVE_ARCH_PFN_VALID
1389 bool
1390
Mike Rapoport5d6ad662020-12-14 19:10:30 -08001391config ARCH_SUPPORTS_DEBUG_PAGEALLOC
1392 bool
1393
Pasha Tatashindf4e8172022-01-14 14:06:37 -08001394config ARCH_SUPPORTS_PAGE_TABLE_CHECK
1395 bool
1396
Brian Gerst2ca408d2020-11-30 17:30:59 -05001397config ARCH_SPLIT_ARG64
1398 bool
1399 help
1400 If a 32-bit architecture requires 64-bit arguments to be split into
1401 pairs of 32-bit arguments, select this option.
1402
Al Viro7facdc42020-06-13 23:03:25 -04001403config ARCH_HAS_ELFCORE_COMPAT
1404 bool
1405
Balbir Singh58e106e2021-04-26 21:59:11 +02001406config ARCH_HAS_PARANOID_L1D_FLUSH
1407 bool
1408
Prasad Sodagudid593d642022-05-18 22:14:14 +05301409config ARCH_HAVE_TRACE_MMIO_ACCESS
1410 bool
1411
Thomas Gleixner1bdda242021-10-21 15:55:05 -07001412config DYNAMIC_SIGFRAME
1413 bool
1414
Jarkko Sakkinen50468e42021-11-16 18:21:16 +02001415# Select, if arch has a named attribute group bound to NUMA device nodes.
1416config HAVE_ARCH_NODE_DEV_GROUP
1417 bool
1418
Yu Zhaoeed9a322022-09-18 01:59:59 -06001419config ARCH_HAS_NONLEAF_PMD_YOUNG
1420 bool
1421 help
1422 Architectures that select this option are capable of setting the
1423 accessed bit in non-leaf PMD entries when using them as part of linear
1424 address translations. Page table walkers that clear the accessed bit
1425 may use this capability to reduce their search space.
1426
Peter Oberparleiter2521f2c2009-06-17 16:28:08 -07001427source "kernel/gcov/Kconfig"
Masahiro Yamada45332b12018-07-05 15:24:12 +09001428
1429source "scripts/gcc-plugins/Kconfig"
Linus Torvaldsfa1b5d02018-08-15 13:05:12 -07001430
Randy Dunlap22471e12018-07-31 13:39:33 +02001431endmenu