1# SPDX-License-Identifier: GPL-2.0
2#
3# General architecture dependent options
4#
5
6#
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
12menu "General architecture-dependent options"
13
14config CRASH_CORE
15	bool
16
17config KEXEC_CORE
18	select CRASH_CORE
19	bool
20
21config KEXEC_ELF
22	bool
23
24config HAVE_IMA_KEXEC
25	bool
26
27config 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
34config HOTPLUG_SMT
35	bool
36
37config GENERIC_ENTRY
38       bool
39
40config KPROBES
41	bool "Kprobes"
42	depends on MODULES
43	depends on HAVE_KPROBES
44	select KALLSYMS
45	select TASKS_RCU if PREEMPTION
46	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
53config JUMP_LABEL
54	bool "Optimize very unlikely/likely branches"
55	depends on HAVE_ARCH_JUMP_LABEL
56	select OBJTOOL if HAVE_JUMP_LABEL_HACK
57	help
58	 This option enables a transparent branch optimization that
59	 makes certain almost-always-true or almost-always-false branch
60	 conditions even cheaper to execute within the kernel.
61
62	 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
66	 If it is detected that the compiler has support for "asm goto",
67	 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. )
78
79config 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
85config 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
91config OPTPROBES
92	def_bool y
93	depends on KPROBES && HAVE_OPTPROBES
94	select TASKS_RCU if PREEMPTION
95
96config 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
105config UPROBES
106	def_bool n
107	depends on ARCH_SUPPORTS_UPROBES
108	help
109	  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. )
118
119config 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
132	  See Documentation/core-api/unaligned-memory-access.rst for
133	  more information on the topic of unaligned memory accesses.
134
135config HAVE_EFFICIENT_UNALIGNED_ACCESS
136	bool
137	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
151	  See Documentation/core-api/unaligned-memory-access.rst for more
152	  information on the topic of unaligned memory accesses.
153
154config ARCH_USE_BUILTIN_BSWAP
155	bool
156	help
157	 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
173config KRETPROBES
174	def_bool y
175	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
182
183config 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
190config HAVE_IOREMAP_PROT
191	bool
192
193config HAVE_KPROBES
194	bool
195
196config HAVE_KRETPROBES
197	bool
198
199config HAVE_OPTPROBES
200	bool
201
202config HAVE_KPROBES_ON_FTRACE
203	bool
204
205config 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
213config HAVE_FUNCTION_ERROR_INJECTION
214	bool
215
216config HAVE_NMI
217	bool
218
219config HAVE_FUNCTION_DESCRIPTORS
220	bool
221
222config TRACE_IRQFLAGS_SUPPORT
223	bool
224
225config TRACE_IRQFLAGS_NMI_SUPPORT
226	bool
227
228#
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
234#	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
237#	TIF_SYSCALL_TRACE	calls ptrace_report_syscall_{entry,exit}
238#	TIF_NOTIFY_RESUME	calls resume_user_mode_work()
239#
240config HAVE_ARCH_TRACEHOOK
241	bool
242
243config HAVE_DMA_CONTIGUOUS
244	bool
245
246config GENERIC_SMP_IDLE_THREAD
247	bool
248
249config GENERIC_IDLE_POLL_SETUP
250	bool
251
252config 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
258#
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
265# Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h
266config ARCH_HAS_SET_MEMORY
267	bool
268
269# Select if arch has all set_direct_map_invalid/default() functions
270config ARCH_HAS_SET_DIRECT_MAP
271	bool
272
273#
274# Select if the architecture provides the arch_dma_set_uncached symbol to
275# either provide an uncached segment alias for a DMA allocation, or
276# to remap the page tables in place.
277#
278config ARCH_HAS_DMA_SET_UNCACHED
279	bool
280
281#
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
286	bool
287
288# Select if arch init_task must go in the __init_task_data section
289config ARCH_TASK_STRUCT_ON_STACK
290	bool
291
292# Select if arch has its private alloc_task_struct() function
293config ARCH_TASK_STRUCT_ALLOCATOR
294	bool
295
296config 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
307# Select if arch has its private alloc_thread_stack() function
308config ARCH_THREAD_STACK_ALLOCATOR
309	bool
310
311# Select if arch wants to size task_struct dynamically via arch_task_struct_size:
312config ARCH_WANTS_DYNAMIC_TASK_STRUCT
313	bool
314
315config 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
322config 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
332# Selected by 64 bit architectures which have a 32 bit f_tinode in struct ustat
333config ARCH_32BIT_USTAT_F_TINODE
334	bool
335
336config HAVE_ASM_MODVERSIONS
337	bool
338	help
339	  This symbol should be selected by an architecture if it provides
340	  <asm/asm-prototypes.h> to support the module versioning for symbols
341	  exported from assembly code.
342
343config HAVE_REGS_AND_STACK_ACCESS_API
344	bool
345	help
346	  This symbol should be selected by an architecture if it supports
347	  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.
350
351config 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
358config HAVE_RUST
359	bool
360	help
361	  This symbol should be selected by an architecture if it
362	  supports Rust.
363
364config HAVE_FUNCTION_ARG_ACCESS_API
365	bool
366	help
367	  This symbol should be selected by an architecture if it supports
368	  the API needed to access function arguments from pt_regs,
369	  declared in asm/ptrace.h
370
371config HAVE_HW_BREAKPOINT
372	bool
373	depends on PERF_EVENTS
374
375config 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
386config HAVE_USER_RETURN_NOTIFIER
387	bool
388
389config HAVE_PERF_EVENTS_NMI
390	bool
391	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.
395
396config 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
418config 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
424config 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
431config HAVE_ARCH_JUMP_LABEL
432	bool
433
434config HAVE_ARCH_JUMP_LABEL_RELATIVE
435	bool
436
437config MMU_GATHER_TABLE_FREE
438	bool
439
440config MMU_GATHER_RCU_TABLE_FREE
441	bool
442	select MMU_GATHER_TABLE_FREE
443
444config MMU_GATHER_PAGE_SIZE
445	bool
446
447config MMU_GATHER_NO_RANGE
448	bool
449	select MMU_GATHER_MERGE_VMAS
450
451config MMU_GATHER_NO_FLUSH_CACHE
452	bool
453
454config MMU_GATHER_MERGE_VMAS
455	bool
456
457config MMU_GATHER_NO_GATHER
458	bool
459	depends on MMU_GATHER_TABLE_FREE
460
461config 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
468config ARCH_HAVE_NMI_SAFE_CMPXCHG
469	bool
470
471config 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
479config HAVE_CMPXCHG_LOCAL
480	bool
481
482config HAVE_CMPXCHG_DOUBLE
483	bool
484
485config ARCH_WEAK_RELEASE_ACQUIRE
486	bool
487
488config ARCH_WANT_IPC_PARSE_VERSION
489	bool
490
491config ARCH_WANT_COMPAT_IPC_PARSE_VERSION
492	bool
493
494config ARCH_WANT_OLD_COMPAT_IPC
495	select ARCH_WANT_COMPAT_IPC_PARSE_VERSION
496	bool
497
498config HAVE_ARCH_SECCOMP
499	bool
500	help
501	  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
513	  An arch should select this symbol if it provides all of these things:
514	  - all the requirements for HAVE_ARCH_SECCOMP
515	  - syscall_get_arch()
516	  - syscall_get_arguments()
517	  - syscall_rollback()
518	  - syscall_set_return_value()
519	  - 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.
523	  - seccomp syscall wired up
524	  - 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.
527
528config 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
545config 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
553	  See Documentation/userspace-api/seccomp_filter.rst for details.
554
555config 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
569config 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
576config HAVE_STACKPROTECTOR
577	bool
578	help
579	  An arch should select this symbol if:
580	  - it has implemented a stack canary (e.g. __stack_chk_guard)
581
582config STACKPROTECTOR
583	bool "Stack Protector buffer overflow detection"
584	depends on HAVE_STACKPROTECTOR
585	depends on $(cc-option,-fstack-protector)
586	default y
587	help
588	  This option turns on the "stack-protector" GCC feature. This
589	  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
596	  Functions will have the stack-protector canary logic added if they
597	  have an 8-byte or larger character array on the stack.
598
599	  This feature requires gcc version 4.2 or above, or a distribution
600	  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
606config STACKPROTECTOR_STRONG
607	bool "Strong Stack Protector"
608	depends on STACKPROTECTOR
609	depends on $(cc-option,-fstack-protector-strong)
610	default y
611	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
628config ARCH_SUPPORTS_SHADOW_CALL_STACK
629	bool
630	help
631	  An architecture should select this if it supports the compiler's
632	  Shadow Call Stack and implements runtime support for shadow stack
633	  switching.
634
635config SHADOW_CALL_STACK
636	bool "Shadow Call Stack"
637	depends on ARCH_SUPPORTS_SHADOW_CALL_STACK
638	depends on DYNAMIC_FTRACE_WITH_ARGS || DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER
639	help
640	  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:
644
645	  - Clang: https://clang.llvm.org/docs/ShadowCallStack.html
646	  - GCC: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options
647
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
654config 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
681	depends on CC_IS_CLANG && LD_IS_LLD && AS_IS_LLVM
682	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
686	depends on !KASAN || KASAN_HW_TAGS
687	depends on !GCOV_KERNEL
688	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
741config 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
747config ARCH_USES_CFI_TRAPS
748	bool
749
750config CFI_CLANG
751	bool "Use Clang's Control Flow Integrity (CFI)"
752	depends on ARCH_SUPPORTS_CFI_CLANG
753	depends on $(cc-option,-fsanitize=kcfi)
754	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
765config 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
775config 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
784config HAVE_CONTEXT_TRACKING_USER
785	bool
786	help
787	  Provide kernel/user boundaries probes necessary for subsystems
788	  that need it, such as userspace RCU extended quiescent state.
789	  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
792	  protected inside ct_irq_enter/ct_irq_exit() but preemption or signal
793	  handling on irq exit still need to be protected.
794
795config HAVE_CONTEXT_TRACKING_USER_OFFSTACK
796	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).
807	  - No use of RCU read side critical sections, unless ct_nmi_enter()
808	    got called.
809	  - No use of instrumentation, unless instrumentation_begin() got
810	    called.
811
812config 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().
817
818config HAVE_VIRT_CPU_ACCOUNTING
819	bool
820
821config 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
827config ARCH_HAS_SCALED_CPUTIME
828	bool
829
830config 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
841config 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
847config 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
854config HAVE_MOVE_PMD
855	bool
856	help
857	  Archs that select this are able to move page tables at the PMD level.
858
859config HAVE_ARCH_TRANSPARENT_HUGEPAGE
860	bool
861
862config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
863	bool
864
865config HAVE_ARCH_HUGE_VMAP
866	bool
867
868#
869#  Archs that select this would be capable of PMD-sized vmaps (i.e.,
870#  arch_vmap_pmd_supported() returns true). The VM_ALLOW_HUGE_VMAP flag
871#  must be used to enable allocations to use hugepages.
872#
873config HAVE_ARCH_HUGE_VMALLOC
874	depends on HAVE_ARCH_HUGE_VMAP
875	bool
876
877config ARCH_WANT_HUGE_PMD_SHARE
878	bool
879
880config HAVE_ARCH_SOFT_DIRTY
881	bool
882
883config 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
902config 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
908config 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
918config HAVE_SOFTIRQ_ON_OWN_STACK
919	bool
920	help
921	  Architecture provides a function to run __do_softirq() on a
922	  separate stack.
923
924config SOFTIRQ_ON_OWN_STACK
925	def_bool HAVE_SOFTIRQ_ON_OWN_STACK && !PREEMPT_RT
926
927config 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
934config PGTABLE_LEVELS
935	int
936	default 2
937
938config 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()
944	  - arch_randomize_brk()
945
946config 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
955config HAVE_EXIT_THREAD
956	bool
957	help
958	  An architecture implements exit_thread.
959
960config 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
1019config 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
1026config 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
1032	depends on PAGE_SIZE_LESS_THAN_256KB
1033
1034config PAGE_SIZE_LESS_THAN_256KB
1035	def_bool y
1036	depends on !PAGE_SIZE_256KB
1037
1038# 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
1047	select ARCH_HAS_ELF_RANDOMIZE
1048
1049config HAVE_OBJTOOL
1050	bool
1051
1052config HAVE_JUMP_LABEL_HACK
1053	bool
1054
1055config HAVE_NOINSTR_HACK
1056	bool
1057
1058config HAVE_NOINSTR_VALIDATION
1059	bool
1060
1061config HAVE_UACCESS_VALIDATION
1062	bool
1063	select OBJTOOL
1064
1065config HAVE_STACK_VALIDATION
1066	bool
1067	help
1068	  Architecture supports objtool compile-time frame pointer rule
1069	  validation.
1070
1071config HAVE_RELIABLE_STACKTRACE
1072	bool
1073	help
1074	  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.
1077
1078config 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
1086config HAVE_ARCH_NVRAM_OPS
1087	bool
1088
1089config ISA_BUS_API
1090	def_bool ISA
1091
1092#
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
1106config CLONE_BACKWARDS3
1107	bool
1108	help
1109	  Architecture has tls passed as the 3rd argument of clone(2),
1110	  not the 5th one.
1111
1112config ODD_RT_SIGACTION
1113	bool
1114	help
1115	  Architecture has unusual rt_sigaction(2) arguments
1116
1117config 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
1127config 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
1138config COMPAT_32BIT_TIME
1139	bool "Provide system calls for 32-bit time_t"
1140	default !64BIT || COMPAT
1141	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
1146config ARCH_NO_PREEMPT
1147	bool
1148
1149config 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
1156config ARCH_SUPPORTS_RT
1157	bool
1158
1159config CPU_NO_EFFICIENT_FFS
1160	def_bool n
1161
1162config 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"
1185	depends on HAVE_ARCH_VMAP_STACK
1186	depends on !KASAN || KASAN_HW_TAGS || KASAN_VMALLOC
1187	help
1188	  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
1193	  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.
1196
1197config 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
1209config RANDOMIZE_KSTACK_OFFSET
1210	bool "Support for randomizing kernel stack offset on syscall entry" if EXPERT
1211	default y
1212	depends on HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET
1213	depends on INIT_STACK_NONE || !CC_IS_CLANG || CLANG_VERSION >= 140000
1214	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
1218	  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.
1233
1234config 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
1243config STRICT_KERNEL_RWX
1244	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
1259config STRICT_MODULE_RWX
1260	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
1268# select if the architecture provides an asm/dma-direct.h header
1269config ARCH_HAS_PHYS_TO_DMA
1270	bool
1271
1272config 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
1280config 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
1290config ARCH_USE_MEMREMAP_PROT
1291	bool
1292
1293config LOCK_EVENT_COUNTS
1294	bool "Locking event counts collection"
1295	depends on DEBUG_FS
1296	help
1297	  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
1302# 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
1316config ARCH_HAS_MEM_ENCRYPT
1317	bool
1318
1319config ARCH_HAS_CC_PLATFORM
1320	bool
1321
1322config 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
1330config ARCH_HAS_VDSO_DATA
1331	bool
1332
1333config HAVE_STATIC_CALL
1334	bool
1335
1336config HAVE_STATIC_CALL_INLINE
1337	bool
1338	depends on HAVE_STATIC_CALL
1339	select OBJTOOL
1340
1341config HAVE_PREEMPT_DYNAMIC
1342	bool
1343
1344config HAVE_PREEMPT_DYNAMIC_CALL
1345	bool
1346	depends on HAVE_STATIC_CALL
1347	select HAVE_PREEMPT_DYNAMIC
1348	help
1349	   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
1364	depends on HAVE_ARCH_JUMP_LABEL
1365	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.
1378
1379config 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
1388config HAVE_ARCH_PFN_VALID
1389	bool
1390
1391config ARCH_SUPPORTS_DEBUG_PAGEALLOC
1392	bool
1393
1394config ARCH_SUPPORTS_PAGE_TABLE_CHECK
1395	bool
1396
1397config 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
1403config ARCH_HAS_ELFCORE_COMPAT
1404	bool
1405
1406config ARCH_HAS_PARANOID_L1D_FLUSH
1407	bool
1408
1409config ARCH_HAVE_TRACE_MMIO_ACCESS
1410	bool
1411
1412config DYNAMIC_SIGFRAME
1413	bool
1414
1415# Select, if arch has a named attribute group bound to NUMA device nodes.
1416config HAVE_ARCH_NODE_DEV_GROUP
1417	bool
1418
1419config 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
1427source "kernel/gcov/Kconfig"
1428
1429source "scripts/gcc-plugins/Kconfig"
1430
1431endmenu
1432