1b2441318SGreg Kroah-Hartman# SPDX-License-Identifier: GPL-2.0 2fb32e03fSMathieu Desnoyers# 3fb32e03fSMathieu Desnoyers# General architecture dependent options 4fb32e03fSMathieu Desnoyers# 5125e5645SMathieu Desnoyers 61572497cSChristoph Hellwig# 71572497cSChristoph Hellwig# Note: arch/$(SRCARCH)/Kconfig needs to be included first so that it can 81572497cSChristoph Hellwig# override the default values in this file. 91572497cSChristoph Hellwig# 101572497cSChristoph Hellwigsource "arch/$(SRCARCH)/Kconfig" 111572497cSChristoph Hellwig 1222471e13SRandy Dunlapmenu "General architecture-dependent options" 1322471e13SRandy Dunlap 14692f66f2SHari Bathiniconfig CRASH_CORE 15692f66f2SHari Bathini bool 16692f66f2SHari Bathini 172965faa5SDave Youngconfig KEXEC_CORE 18692f66f2SHari Bathini select CRASH_CORE 192965faa5SDave Young bool 202965faa5SDave Young 21175fca3bSSven Schnelleconfig KEXEC_ELF 22175fca3bSSven Schnelle bool 23175fca3bSSven Schnelle 24467d2782SThiago Jung Bauermannconfig HAVE_IMA_KEXEC 25467d2782SThiago Jung Bauermann bool 26467d2782SThiago Jung Bauermann 27da32b581SCatalin Marinasconfig ARCH_HAS_SUBPAGE_FAULTS 28da32b581SCatalin Marinas bool 29da32b581SCatalin Marinas help 30da32b581SCatalin Marinas Select if the architecture can check permissions at sub-page 31da32b581SCatalin Marinas granularity (e.g. arm64 MTE). The probe_user_*() functions 32da32b581SCatalin Marinas must be implemented. 33da32b581SCatalin Marinas 3405736e4aSThomas Gleixnerconfig HOTPLUG_SMT 3505736e4aSThomas Gleixner bool 3605736e4aSThomas Gleixner 37142781e1SThomas Gleixnerconfig GENERIC_ENTRY 38142781e1SThomas Gleixner bool 39142781e1SThomas Gleixner 40125e5645SMathieu Desnoyersconfig KPROBES 41125e5645SMathieu Desnoyers bool "Kprobes" 4205ed160eSMasami Hiramatsu depends on MODULES 43125e5645SMathieu Desnoyers depends on HAVE_KPROBES 4405ed160eSMasami Hiramatsu select KALLSYMS 45835f14edSPaul E. McKenney select TASKS_RCU if PREEMPTION 46125e5645SMathieu Desnoyers help 47125e5645SMathieu Desnoyers Kprobes allows you to trap at almost any kernel address and 48125e5645SMathieu Desnoyers execute a callback function. register_kprobe() establishes 49125e5645SMathieu Desnoyers a probepoint and specifies the callback. Kprobes is useful 50125e5645SMathieu Desnoyers for kernel debugging, non-intrusive instrumentation and testing. 51125e5645SMathieu Desnoyers If in doubt, say "N". 52125e5645SMathieu Desnoyers 5345f81b1cSSteven Rostedtconfig JUMP_LABEL 54c5905afbSIngo Molnar bool "Optimize very unlikely/likely branches" 5545f81b1cSSteven Rostedt depends on HAVE_ARCH_JUMP_LABEL 564ab7674fSJosh Poimboeuf select OBJTOOL if HAVE_JUMP_LABEL_HACK 5745f81b1cSSteven Rostedt help 58c5905afbSIngo Molnar This option enables a transparent branch optimization that 59c5905afbSIngo Molnar makes certain almost-always-true or almost-always-false branch 60c5905afbSIngo Molnar conditions even cheaper to execute within the kernel. 6145f81b1cSSteven Rostedt 62c5905afbSIngo Molnar Certain performance-sensitive kernel code, such as trace points, 63c5905afbSIngo Molnar scheduler functionality, networking code and KVM have such 64c5905afbSIngo Molnar branches and include support for this optimization technique. 65c5905afbSIngo Molnar 66c5905afbSIngo Molnar If it is detected that the compiler has support for "asm goto", 67c5905afbSIngo Molnar the kernel will compile such branches with just a nop 68c5905afbSIngo Molnar instruction. When the condition flag is toggled to true, the 69c5905afbSIngo Molnar nop will be converted to a jump instruction to execute the 70c5905afbSIngo Molnar conditional block of instructions. 71c5905afbSIngo Molnar 72c5905afbSIngo Molnar This technique lowers overhead and stress on the branch prediction 73c5905afbSIngo Molnar of the processor and generally makes the kernel faster. The update 74c5905afbSIngo Molnar of the condition is slower, but those are always very rare. 75c5905afbSIngo Molnar 76c5905afbSIngo Molnar ( On 32-bit x86, the necessary options added to the compiler 77c5905afbSIngo Molnar flags may increase the size of the kernel slightly. ) 7845f81b1cSSteven Rostedt 791987c947SPeter Zijlstraconfig STATIC_KEYS_SELFTEST 801987c947SPeter Zijlstra bool "Static key selftest" 811987c947SPeter Zijlstra depends on JUMP_LABEL 821987c947SPeter Zijlstra help 831987c947SPeter Zijlstra Boot time self-test of the branch patching code. 841987c947SPeter Zijlstra 85f03c4129SPeter Zijlstraconfig STATIC_CALL_SELFTEST 86f03c4129SPeter Zijlstra bool "Static call selftest" 87f03c4129SPeter Zijlstra depends on HAVE_STATIC_CALL 88f03c4129SPeter Zijlstra help 89f03c4129SPeter Zijlstra Boot time self-test of the call patching code. 90f03c4129SPeter Zijlstra 91afd66255SMasami Hiramatsuconfig OPTPROBES 925cc718b9SMasami Hiramatsu def_bool y 935cc718b9SMasami Hiramatsu depends on KPROBES && HAVE_OPTPROBES 9401b1d88bSThomas Gleixner select TASKS_RCU if PREEMPTION 95afd66255SMasami Hiramatsu 96e7dbfe34SMasami Hiramatsuconfig KPROBES_ON_FTRACE 97e7dbfe34SMasami Hiramatsu def_bool y 98e7dbfe34SMasami Hiramatsu depends on KPROBES && HAVE_KPROBES_ON_FTRACE 99e7dbfe34SMasami Hiramatsu depends on DYNAMIC_FTRACE_WITH_REGS 100e7dbfe34SMasami Hiramatsu help 101e7dbfe34SMasami Hiramatsu If function tracer is enabled and the arch supports full 102e7dbfe34SMasami Hiramatsu passing of pt_regs to function tracing, then kprobes can 103e7dbfe34SMasami Hiramatsu optimize on top of function tracing. 104e7dbfe34SMasami Hiramatsu 1052b144498SSrikar Dronamrajuconfig UPROBES 10609294e31SDavid A. Long def_bool n 107e8f4aa60SAllen Pais depends on ARCH_SUPPORTS_UPROBES 1082b144498SSrikar Dronamraju help 1097b2d81d4SIngo Molnar Uprobes is the user-space counterpart to kprobes: they 1107b2d81d4SIngo Molnar enable instrumentation applications (such as 'perf probe') 1117b2d81d4SIngo Molnar to establish unintrusive probes in user-space binaries and 1127b2d81d4SIngo Molnar libraries, by executing handler functions when the probes 1137b2d81d4SIngo Molnar are hit by user-space applications. 1147b2d81d4SIngo Molnar 1157b2d81d4SIngo Molnar ( These probes come in the form of single-byte breakpoints, 1167b2d81d4SIngo Molnar managed by the kernel and kept transparent to the probed 1177b2d81d4SIngo Molnar application. ) 1182b144498SSrikar Dronamraju 119adab66b7SSteven Rostedt (VMware)config HAVE_64BIT_ALIGNED_ACCESS 120adab66b7SSteven Rostedt (VMware) def_bool 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS 121adab66b7SSteven Rostedt (VMware) help 122adab66b7SSteven Rostedt (VMware) Some architectures require 64 bit accesses to be 64 bit 123adab66b7SSteven Rostedt (VMware) aligned, which also requires structs containing 64 bit values 124adab66b7SSteven Rostedt (VMware) to be 64 bit aligned too. This includes some 32 bit 125adab66b7SSteven Rostedt (VMware) architectures which can do 64 bit accesses, as well as 64 bit 126adab66b7SSteven Rostedt (VMware) architectures without unaligned access. 127adab66b7SSteven Rostedt (VMware) 128adab66b7SSteven Rostedt (VMware) This symbol should be selected by an architecture if 64 bit 129adab66b7SSteven Rostedt (VMware) accesses are required to be 64 bit aligned in this way even 130adab66b7SSteven Rostedt (VMware) though it is not a 64 bit architecture. 131adab66b7SSteven Rostedt (VMware) 132ba1a297dSLukas Bulwahn See Documentation/core-api/unaligned-memory-access.rst for 133ba1a297dSLukas Bulwahn more information on the topic of unaligned memory accesses. 134adab66b7SSteven Rostedt (VMware) 13558340a07SJohannes Bergconfig HAVE_EFFICIENT_UNALIGNED_ACCESS 1369ba16087SJan Beulich bool 13758340a07SJohannes Berg help 13858340a07SJohannes Berg Some architectures are unable to perform unaligned accesses 13958340a07SJohannes Berg without the use of get_unaligned/put_unaligned. Others are 14058340a07SJohannes Berg unable to perform such accesses efficiently (e.g. trap on 14158340a07SJohannes Berg unaligned access and require fixing it up in the exception 14258340a07SJohannes Berg handler.) 14358340a07SJohannes Berg 14458340a07SJohannes Berg This symbol should be selected by an architecture if it can 14558340a07SJohannes Berg perform unaligned accesses efficiently to allow different 14658340a07SJohannes Berg code paths to be selected for these cases. Some network 14758340a07SJohannes Berg drivers, for example, could opt to not fix up alignment 14858340a07SJohannes Berg problems with received packets if doing so would not help 14958340a07SJohannes Berg much. 15058340a07SJohannes Berg 151c9b54d6fSMauro Carvalho Chehab See Documentation/core-api/unaligned-memory-access.rst for more 15258340a07SJohannes Berg information on the topic of unaligned memory accesses. 15358340a07SJohannes Berg 154cf66bb93SDavid Woodhouseconfig ARCH_USE_BUILTIN_BSWAP 155cf66bb93SDavid Woodhouse bool 156cf66bb93SDavid Woodhouse help 157cf66bb93SDavid Woodhouse Modern versions of GCC (since 4.4) have builtin functions 158cf66bb93SDavid Woodhouse for handling byte-swapping. Using these, instead of the old 159cf66bb93SDavid Woodhouse inline assembler that the architecture code provides in the 160cf66bb93SDavid Woodhouse __arch_bswapXX() macros, allows the compiler to see what's 161cf66bb93SDavid Woodhouse happening and offers more opportunity for optimisation. In 162cf66bb93SDavid Woodhouse particular, the compiler will be able to combine the byteswap 163cf66bb93SDavid Woodhouse with a nearby load or store and use load-and-swap or 164cf66bb93SDavid Woodhouse store-and-swap instructions if the architecture has them. It 165cf66bb93SDavid Woodhouse should almost *never* result in code which is worse than the 166cf66bb93SDavid Woodhouse hand-coded assembler in <asm/swab.h>. But just in case it 167cf66bb93SDavid Woodhouse does, the use of the builtins is optional. 168cf66bb93SDavid Woodhouse 169cf66bb93SDavid Woodhouse Any architecture with load-and-swap or store-and-swap 170cf66bb93SDavid Woodhouse instructions should set this. And it shouldn't hurt to set it 171cf66bb93SDavid Woodhouse on architectures that don't have such instructions. 172cf66bb93SDavid Woodhouse 1739edddaa2SAnanth N Mavinakayanahalliconfig KRETPROBES 1749edddaa2SAnanth N Mavinakayanahalli def_bool y 17573f9b911SMasami Hiramatsu depends on KPROBES && (HAVE_KRETPROBES || HAVE_RETHOOK) 17673f9b911SMasami Hiramatsu 17773f9b911SMasami Hiramatsuconfig KRETPROBE_ON_RETHOOK 17873f9b911SMasami Hiramatsu def_bool y 17973f9b911SMasami Hiramatsu depends on HAVE_RETHOOK 18073f9b911SMasami Hiramatsu depends on KRETPROBES 18173f9b911SMasami Hiramatsu select RETHOOK 1829edddaa2SAnanth N Mavinakayanahalli 1837c68af6eSAvi Kivityconfig USER_RETURN_NOTIFIER 1847c68af6eSAvi Kivity bool 1857c68af6eSAvi Kivity depends on HAVE_USER_RETURN_NOTIFIER 1867c68af6eSAvi Kivity help 1877c68af6eSAvi Kivity Provide a kernel-internal notification when a cpu is about to 1887c68af6eSAvi Kivity switch to user mode. 1897c68af6eSAvi Kivity 19028b2ee20SRik van Rielconfig HAVE_IOREMAP_PROT 1919ba16087SJan Beulich bool 19228b2ee20SRik van Riel 193125e5645SMathieu Desnoyersconfig HAVE_KPROBES 1949ba16087SJan Beulich bool 1959edddaa2SAnanth N Mavinakayanahalli 1969edddaa2SAnanth N Mavinakayanahalliconfig HAVE_KRETPROBES 1979ba16087SJan Beulich bool 19874bc7ceeSArthur Kepner 199afd66255SMasami Hiramatsuconfig HAVE_OPTPROBES 200afd66255SMasami Hiramatsu bool 201d314d74cSCong Wang 202e7dbfe34SMasami Hiramatsuconfig HAVE_KPROBES_ON_FTRACE 203e7dbfe34SMasami Hiramatsu bool 204e7dbfe34SMasami Hiramatsu 2051f6d3a8fSMasami Hiramatsuconfig ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 2061f6d3a8fSMasami Hiramatsu bool 2071f6d3a8fSMasami Hiramatsu help 2081f6d3a8fSMasami Hiramatsu Since kretprobes modifies return address on the stack, the 2091f6d3a8fSMasami Hiramatsu stacktrace may see the kretprobe trampoline address instead 2101f6d3a8fSMasami Hiramatsu of correct one. If the architecture stacktrace code and 2111f6d3a8fSMasami Hiramatsu unwinder can adjust such entries, select this configuration. 2121f6d3a8fSMasami Hiramatsu 213540adea3SMasami Hiramatsuconfig HAVE_FUNCTION_ERROR_INJECTION 2149802d865SJosef Bacik bool 2159802d865SJosef Bacik 21642a0bb3fSPetr Mladekconfig HAVE_NMI 21742a0bb3fSPetr Mladek bool 21842a0bb3fSPetr Mladek 219a257caccSChristophe Leroyconfig HAVE_FUNCTION_DESCRIPTORS 220a257caccSChristophe Leroy bool 221a257caccSChristophe Leroy 2224aae683fSMasahiro Yamadaconfig TRACE_IRQFLAGS_SUPPORT 2234aae683fSMasahiro Yamada bool 2244aae683fSMasahiro Yamada 2254510bffbSMark Rutlandconfig TRACE_IRQFLAGS_NMI_SUPPORT 2264510bffbSMark Rutland bool 2274510bffbSMark Rutland 2281f5a4ad9SRoland McGrath# 2291f5a4ad9SRoland McGrath# An arch should select this if it provides all these things: 2301f5a4ad9SRoland McGrath# 2311f5a4ad9SRoland McGrath# task_pt_regs() in asm/processor.h or asm/ptrace.h 2321f5a4ad9SRoland McGrath# arch_has_single_step() if there is hardware single-step support 2331f5a4ad9SRoland McGrath# arch_has_block_step() if there is hardware block-step support 2341f5a4ad9SRoland McGrath# asm/syscall.h supplying asm-generic/syscall.h interface 2351f5a4ad9SRoland McGrath# linux/regset.h user_regset interfaces 2361f5a4ad9SRoland McGrath# CORE_DUMP_USE_REGSET #define'd in linux/elf.h 237153474baSEric W. Biederman# TIF_SYSCALL_TRACE calls ptrace_report_syscall_{entry,exit} 23803248addSEric W. Biederman# TIF_NOTIFY_RESUME calls resume_user_mode_work() 2391f5a4ad9SRoland McGrath# 2401f5a4ad9SRoland McGrathconfig HAVE_ARCH_TRACEHOOK 2419ba16087SJan Beulich bool 2421f5a4ad9SRoland McGrath 243c64be2bbSMarek Szyprowskiconfig HAVE_DMA_CONTIGUOUS 244c64be2bbSMarek Szyprowski bool 245c64be2bbSMarek Szyprowski 24629d5e047SThomas Gleixnerconfig GENERIC_SMP_IDLE_THREAD 24729d5e047SThomas Gleixner bool 24829d5e047SThomas Gleixner 249485cf5daSKevin Hilmanconfig GENERIC_IDLE_POLL_SETUP 250485cf5daSKevin Hilman bool 251485cf5daSKevin Hilman 2526974f0c4SDaniel Micayconfig ARCH_HAS_FORTIFY_SOURCE 2536974f0c4SDaniel Micay bool 2546974f0c4SDaniel Micay help 2556974f0c4SDaniel Micay An architecture should select this when it can successfully 2566974f0c4SDaniel Micay build and run with CONFIG_FORTIFY_SOURCE. 2576974f0c4SDaniel Micay 258d8ae8a37SChristoph Hellwig# 259d8ae8a37SChristoph Hellwig# Select if the arch provides a historic keepinit alias for the retain_initrd 260d8ae8a37SChristoph Hellwig# command line option 261d8ae8a37SChristoph Hellwig# 262d8ae8a37SChristoph Hellwigconfig ARCH_HAS_KEEPINITRD 263d8ae8a37SChristoph Hellwig bool 264d8ae8a37SChristoph Hellwig 265d2852a22SDaniel Borkmann# Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h 266d2852a22SDaniel Borkmannconfig ARCH_HAS_SET_MEMORY 267d2852a22SDaniel Borkmann bool 268d2852a22SDaniel Borkmann 269d253ca0cSRick Edgecombe# Select if arch has all set_direct_map_invalid/default() functions 270d253ca0cSRick Edgecombeconfig ARCH_HAS_SET_DIRECT_MAP 271d253ca0cSRick Edgecombe bool 272d253ca0cSRick Edgecombe 273c30700dbSChristoph Hellwig# 274fa7e2247SChristoph Hellwig# Select if the architecture provides the arch_dma_set_uncached symbol to 275a86ecfa6SColin Ian King# either provide an uncached segment alias for a DMA allocation, or 276fa7e2247SChristoph Hellwig# to remap the page tables in place. 277c30700dbSChristoph Hellwig# 278fa7e2247SChristoph Hellwigconfig ARCH_HAS_DMA_SET_UNCACHED 279c30700dbSChristoph Hellwig bool 280c30700dbSChristoph Hellwig 281999a5d12SChristoph Hellwig# 282999a5d12SChristoph Hellwig# Select if the architectures provides the arch_dma_clear_uncached symbol 283999a5d12SChristoph Hellwig# to undo an in-place page table remap for uncached access. 284999a5d12SChristoph Hellwig# 285999a5d12SChristoph Hellwigconfig ARCH_HAS_DMA_CLEAR_UNCACHED 286f5e10287SThomas Gleixner bool 287f5e10287SThomas Gleixner 2885905429aSKees Cook# Select if arch init_task must go in the __init_task_data section 2895905429aSKees Cookconfig ARCH_TASK_STRUCT_ON_STACK 2905905429aSKees Cook bool 2915905429aSKees Cook 2925905429aSKees Cook# Select if arch has its private alloc_task_struct() function 2935905429aSKees Cookconfig ARCH_TASK_STRUCT_ALLOCATOR 2945905429aSKees Cook bool 2955905429aSKees Cook 2965905429aSKees Cookconfig HAVE_ARCH_THREAD_STRUCT_WHITELIST 2975905429aSKees Cook bool 2985905429aSKees Cook depends on !ARCH_TASK_STRUCT_ALLOCATOR 299b235beeaSLinus Torvalds help 300b235beeaSLinus Torvalds An architecture should select this to provide hardened usercopy 301f5e10287SThomas Gleixner knowledge about what region of the thread_struct should be 302f5e10287SThomas Gleixner whitelisted for copying to userspace. Normally this is only the 3035aaeb5c0SIngo Molnar FPU registers. Specifically, arch_thread_struct_whitelist() 3045aaeb5c0SIngo Molnar should be implemented. Without this, the entire thread_struct 3055aaeb5c0SIngo Molnar field in task_struct will be left whitelisted. 3065aaeb5c0SIngo Molnar 307942fa985SYury Norov# Select if arch has its private alloc_thread_stack() function 308942fa985SYury Norovconfig ARCH_THREAD_STACK_ALLOCATOR 309942fa985SYury Norov bool 310942fa985SYury Norov 311942fa985SYury Norov# Select if arch wants to size task_struct dynamically via arch_task_struct_size: 312942fa985SYury Norovconfig ARCH_WANTS_DYNAMIC_TASK_STRUCT 313942fa985SYury Norov bool 314942fa985SYury Norov 31551c2ee6dSNick Desaulniersconfig ARCH_WANTS_NO_INSTR 31651c2ee6dSNick Desaulniers bool 31751c2ee6dSNick Desaulniers help 31851c2ee6dSNick Desaulniers An architecture should select this if the noinstr macro is being used on 31951c2ee6dSNick Desaulniers functions to denote that the toolchain should avoid instrumenting such 32051c2ee6dSNick Desaulniers functions and is required for correctness. 32151c2ee6dSNick Desaulniers 322942fa985SYury Norovconfig ARCH_32BIT_OFF_T 323942fa985SYury Norov bool 324942fa985SYury Norov depends on !64BIT 325942fa985SYury Norov help 326942fa985SYury Norov All new 32-bit architectures should have 64-bit off_t type on 327942fa985SYury Norov userspace side which corresponds to the loff_t kernel type. This 328942fa985SYury Norov is the requirement for modern ABIs. Some existing architectures 329942fa985SYury Norov still support 32-bit off_t. This option is enabled for all such 330942fa985SYury Norov architectures explicitly. 331942fa985SYury Norov 33296c0a6a7SHeiko Carstens# Selected by 64 bit architectures which have a 32 bit f_tinode in struct ustat 33396c0a6a7SHeiko Carstensconfig ARCH_32BIT_USTAT_F_TINODE 33496c0a6a7SHeiko Carstens bool 33596c0a6a7SHeiko Carstens 3362ff2b7ecSMasahiro Yamadaconfig HAVE_ASM_MODVERSIONS 3372ff2b7ecSMasahiro Yamada bool 3382ff2b7ecSMasahiro Yamada help 339a86ecfa6SColin Ian King This symbol should be selected by an architecture if it provides 3402ff2b7ecSMasahiro Yamada <asm/asm-prototypes.h> to support the module versioning for symbols 3412ff2b7ecSMasahiro Yamada exported from assembly code. 3422ff2b7ecSMasahiro Yamada 343f850c30cSHeiko Carstensconfig HAVE_REGS_AND_STACK_ACCESS_API 344f850c30cSHeiko Carstens bool 345e01292b1SHeiko Carstens help 346a86ecfa6SColin Ian King This symbol should be selected by an architecture if it supports 347e01292b1SHeiko Carstens the API needed to access registers and stack entries from pt_regs, 348e01292b1SHeiko Carstens declared in asm/ptrace.h 349e01292b1SHeiko Carstens For example the kprobes-based event tracer needs this API. 350f850c30cSHeiko Carstens 351d7822b1eSMathieu Desnoyersconfig HAVE_RSEQ 352d7822b1eSMathieu Desnoyers bool 353d7822b1eSMathieu Desnoyers depends on HAVE_REGS_AND_STACK_ACCESS_API 354d7822b1eSMathieu Desnoyers help 355d7822b1eSMathieu Desnoyers This symbol should be selected by an architecture if it 356d7822b1eSMathieu Desnoyers supports an implementation of restartable sequences. 357d7822b1eSMathieu Desnoyers 3582f7ab126SMiguel Ojedaconfig HAVE_RUST 3592f7ab126SMiguel Ojeda bool 3602f7ab126SMiguel Ojeda help 3612f7ab126SMiguel Ojeda This symbol should be selected by an architecture if it 3622f7ab126SMiguel Ojeda supports Rust. 3632f7ab126SMiguel Ojeda 3643c88ee19SMasami Hiramatsuconfig HAVE_FUNCTION_ARG_ACCESS_API 3653c88ee19SMasami Hiramatsu bool 3663c88ee19SMasami Hiramatsu help 367a86ecfa6SColin Ian King This symbol should be selected by an architecture if it supports 3683c88ee19SMasami Hiramatsu the API needed to access function arguments from pt_regs, 3693c88ee19SMasami Hiramatsu declared in asm/ptrace.h 3703c88ee19SMasami Hiramatsu 37162a038d3SK.Prasadconfig HAVE_HW_BREAKPOINT 37262a038d3SK.Prasad bool 37399e8c5a3SFrederic Weisbecker depends on PERF_EVENTS 37462a038d3SK.Prasad 3750102752eSFrederic Weisbeckerconfig HAVE_MIXED_BREAKPOINTS_REGS 3760102752eSFrederic Weisbecker bool 3770102752eSFrederic Weisbecker depends on HAVE_HW_BREAKPOINT 3780102752eSFrederic Weisbecker help 3790102752eSFrederic Weisbecker Depending on the arch implementation of hardware breakpoints, 3800102752eSFrederic Weisbecker some of them have separate registers for data and instruction 3810102752eSFrederic Weisbecker breakpoints addresses, others have mixed registers to store 3820102752eSFrederic Weisbecker them but define the access type in a control register. 3830102752eSFrederic Weisbecker Select this option if your arch implements breakpoints under the 3840102752eSFrederic Weisbecker latter fashion. 3850102752eSFrederic Weisbecker 3867c68af6eSAvi Kivityconfig HAVE_USER_RETURN_NOTIFIER 3877c68af6eSAvi Kivity bool 388a1922ed6SIngo Molnar 389c01d4323SFrederic Weisbeckerconfig HAVE_PERF_EVENTS_NMI 390c01d4323SFrederic Weisbecker bool 39123637d47SFrederic Weisbecker help 39223637d47SFrederic Weisbecker System hardware can generate an NMI using the perf event 39323637d47SFrederic Weisbecker subsystem. Also has support for calculating CPU cycle events 39423637d47SFrederic Weisbecker to determine how many clock cycles in a given period. 395c01d4323SFrederic Weisbecker 39605a4a952SNicholas Pigginconfig HAVE_HARDLOCKUP_DETECTOR_PERF 39705a4a952SNicholas Piggin bool 39805a4a952SNicholas Piggin depends on HAVE_PERF_EVENTS_NMI 39905a4a952SNicholas Piggin help 40005a4a952SNicholas Piggin The arch chooses to use the generic perf-NMI-based hardlockup 40105a4a952SNicholas Piggin detector. Must define HAVE_PERF_EVENTS_NMI. 40205a4a952SNicholas Piggin 40305a4a952SNicholas Pigginconfig HAVE_NMI_WATCHDOG 40405a4a952SNicholas Piggin depends on HAVE_NMI 40505a4a952SNicholas Piggin bool 40605a4a952SNicholas Piggin help 40705a4a952SNicholas Piggin The arch provides a low level NMI watchdog. It provides 40805a4a952SNicholas Piggin asm/nmi.h, and defines its own arch_touch_nmi_watchdog(). 40905a4a952SNicholas Piggin 41005a4a952SNicholas Pigginconfig HAVE_HARDLOCKUP_DETECTOR_ARCH 41105a4a952SNicholas Piggin bool 41205a4a952SNicholas Piggin select HAVE_NMI_WATCHDOG 41305a4a952SNicholas Piggin help 41405a4a952SNicholas Piggin The arch chooses to provide its own hardlockup detector, which is 41505a4a952SNicholas Piggin a superset of the HAVE_NMI_WATCHDOG. It also conforms to config 41605a4a952SNicholas Piggin interfaces and parameters provided by hardlockup detector subsystem. 41705a4a952SNicholas Piggin 418c5e63197SJiri Olsaconfig HAVE_PERF_REGS 419c5e63197SJiri Olsa bool 420c5e63197SJiri Olsa help 421c5e63197SJiri Olsa Support selective register dumps for perf events. This includes 422c5e63197SJiri Olsa bit-mapping of each registers and a unique architecture id. 423c5e63197SJiri Olsa 424c5ebcedbSJiri Olsaconfig HAVE_PERF_USER_STACK_DUMP 425c5ebcedbSJiri Olsa bool 426c5ebcedbSJiri Olsa help 427c5ebcedbSJiri Olsa Support user stack dumps for perf event samples. This needs 428c5ebcedbSJiri Olsa access to the user stack pointer which is not unified across 429c5ebcedbSJiri Olsa architectures. 430c5ebcedbSJiri Olsa 431bf5438fcSJason Baronconfig HAVE_ARCH_JUMP_LABEL 432bf5438fcSJason Baron bool 433bf5438fcSJason Baron 43450ff18abSArd Biesheuvelconfig HAVE_ARCH_JUMP_LABEL_RELATIVE 43550ff18abSArd Biesheuvel bool 43650ff18abSArd Biesheuvel 4370d6e24d4SPeter Zijlstraconfig MMU_GATHER_TABLE_FREE 4380d6e24d4SPeter Zijlstra bool 4390d6e24d4SPeter Zijlstra 440ff2e6d72SPeter Zijlstraconfig MMU_GATHER_RCU_TABLE_FREE 44126723911SPeter Zijlstra bool 4420d6e24d4SPeter Zijlstra select MMU_GATHER_TABLE_FREE 44326723911SPeter Zijlstra 4443af4bd03SPeter Zijlstraconfig MMU_GATHER_PAGE_SIZE 445ed6a7935SPeter Zijlstra bool 446ed6a7935SPeter Zijlstra 44727796d03SPeter Zijlstraconfig MMU_GATHER_NO_RANGE 44827796d03SPeter Zijlstra bool 4491e9fdf21SPeter Zijlstra select MMU_GATHER_MERGE_VMAS 4501e9fdf21SPeter Zijlstra 4511e9fdf21SPeter Zijlstraconfig MMU_GATHER_NO_FLUSH_CACHE 4521e9fdf21SPeter Zijlstra bool 4531e9fdf21SPeter Zijlstra 4541e9fdf21SPeter Zijlstraconfig MMU_GATHER_MERGE_VMAS 4551e9fdf21SPeter Zijlstra bool 45627796d03SPeter Zijlstra 457580a586cSPeter Zijlstraconfig MMU_GATHER_NO_GATHER 458952a31c9SMartin Schwidefsky bool 4590d6e24d4SPeter Zijlstra depends on MMU_GATHER_TABLE_FREE 460952a31c9SMartin Schwidefsky 461d53c3dfbSNicholas Pigginconfig ARCH_WANT_IRQS_OFF_ACTIVATE_MM 462d53c3dfbSNicholas Piggin bool 463d53c3dfbSNicholas Piggin help 464d53c3dfbSNicholas Piggin Temporary select until all architectures can be converted to have 465d53c3dfbSNicholas Piggin irqs disabled over activate_mm. Architectures that do IPI based TLB 466d53c3dfbSNicholas Piggin shootdowns should enable this. 467d53c3dfbSNicholas Piggin 468df013ffbSHuang Yingconfig ARCH_HAVE_NMI_SAFE_CMPXCHG 469df013ffbSHuang Ying bool 470df013ffbSHuang Ying 47143570fd2SHeiko Carstensconfig HAVE_ALIGNED_STRUCT_PAGE 47243570fd2SHeiko Carstens bool 47343570fd2SHeiko Carstens help 47443570fd2SHeiko Carstens This makes sure that struct pages are double word aligned and that 47543570fd2SHeiko Carstens e.g. the SLUB allocator can perform double word atomic operations 47643570fd2SHeiko Carstens on a struct page for better performance. However selecting this 47743570fd2SHeiko Carstens might increase the size of a struct page by a word. 47843570fd2SHeiko Carstens 4794156153cSHeiko Carstensconfig HAVE_CMPXCHG_LOCAL 4804156153cSHeiko Carstens bool 4814156153cSHeiko Carstens 4822565409fSHeiko Carstensconfig HAVE_CMPXCHG_DOUBLE 4832565409fSHeiko Carstens bool 4842565409fSHeiko Carstens 48577e58496SPaul E. McKenneyconfig ARCH_WEAK_RELEASE_ACQUIRE 48677e58496SPaul E. McKenney bool 48777e58496SPaul E. McKenney 488c1d7e01dSWill Deaconconfig ARCH_WANT_IPC_PARSE_VERSION 489c1d7e01dSWill Deacon bool 490c1d7e01dSWill Deacon 491c1d7e01dSWill Deaconconfig ARCH_WANT_COMPAT_IPC_PARSE_VERSION 492c1d7e01dSWill Deacon bool 493c1d7e01dSWill Deacon 49448b25c43SChris Metcalfconfig ARCH_WANT_OLD_COMPAT_IPC 495c1d7e01dSWill Deacon select ARCH_WANT_COMPAT_IPC_PARSE_VERSION 49648b25c43SChris Metcalf bool 49748b25c43SChris Metcalf 498282a181bSYiFei Zhuconfig HAVE_ARCH_SECCOMP 499e2cfabdfSWill Drewry bool 500e2cfabdfSWill Drewry help 501282a181bSYiFei Zhu An arch should select this symbol to support seccomp mode 1 (the fixed 502282a181bSYiFei Zhu syscall policy), and must provide an overrides for __NR_seccomp_sigreturn, 503282a181bSYiFei Zhu and compat syscalls if the asm-generic/seccomp.h defaults need adjustment: 504282a181bSYiFei Zhu - __NR_seccomp_read_32 505282a181bSYiFei Zhu - __NR_seccomp_write_32 506282a181bSYiFei Zhu - __NR_seccomp_exit_32 507282a181bSYiFei Zhu - __NR_seccomp_sigreturn_32 508282a181bSYiFei Zhu 509282a181bSYiFei Zhuconfig HAVE_ARCH_SECCOMP_FILTER 510282a181bSYiFei Zhu bool 511282a181bSYiFei Zhu select HAVE_ARCH_SECCOMP 512282a181bSYiFei Zhu help 513fb0fadf9SWill Drewry An arch should select this symbol if it provides all of these things: 514282a181bSYiFei Zhu - all the requirements for HAVE_ARCH_SECCOMP 515bb6ea430SWill Drewry - syscall_get_arch() 516bb6ea430SWill Drewry - syscall_get_arguments() 517bb6ea430SWill Drewry - syscall_rollback() 518bb6ea430SWill Drewry - syscall_set_return_value() 519fb0fadf9SWill Drewry - SIGSYS siginfo_t support 520fb0fadf9SWill Drewry - secure_computing is called from a ptrace_event()-safe context 521fb0fadf9SWill Drewry - secure_computing return value is checked and a return value of -1 522fb0fadf9SWill Drewry results in the system call being skipped immediately. 52348dc92b9SKees Cook - seccomp syscall wired up 5240d8315ddSYiFei Zhu - if !HAVE_SPARSE_SYSCALL_NR, have SECCOMP_ARCH_NATIVE, 5250d8315ddSYiFei Zhu SECCOMP_ARCH_NATIVE_NR, SECCOMP_ARCH_NATIVE_NAME defined. If 5260d8315ddSYiFei Zhu COMPAT is supported, have the SECCOMP_ARCH_COMPAT* defines too. 527e2cfabdfSWill Drewry 528282a181bSYiFei Zhuconfig SECCOMP 529282a181bSYiFei Zhu prompt "Enable seccomp to safely execute untrusted bytecode" 530282a181bSYiFei Zhu def_bool y 531282a181bSYiFei Zhu depends on HAVE_ARCH_SECCOMP 532282a181bSYiFei Zhu help 533282a181bSYiFei Zhu This kernel feature is useful for number crunching applications 534282a181bSYiFei Zhu that may need to handle untrusted bytecode during their 535282a181bSYiFei Zhu execution. By using pipes or other transports made available 536282a181bSYiFei Zhu to the process as file descriptors supporting the read/write 537282a181bSYiFei Zhu syscalls, it's possible to isolate those applications in their 538282a181bSYiFei Zhu own address space using seccomp. Once seccomp is enabled via 539282a181bSYiFei Zhu prctl(PR_SET_SECCOMP) or the seccomp() syscall, it cannot be 540282a181bSYiFei Zhu disabled and the task is only allowed to execute a few safe 541282a181bSYiFei Zhu syscalls defined by each seccomp mode. 542282a181bSYiFei Zhu 543282a181bSYiFei Zhu If unsure, say Y. 544282a181bSYiFei Zhu 545e2cfabdfSWill Drewryconfig SECCOMP_FILTER 546e2cfabdfSWill Drewry def_bool y 547e2cfabdfSWill Drewry depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET 548e2cfabdfSWill Drewry help 549e2cfabdfSWill Drewry Enable tasks to build secure computing environments defined 550e2cfabdfSWill Drewry in terms of Berkeley Packet Filter programs which implement 551e2cfabdfSWill Drewry task-defined system call filtering polices. 552e2cfabdfSWill Drewry 5535fb94e9cSMauro Carvalho Chehab See Documentation/userspace-api/seccomp_filter.rst for details. 554e2cfabdfSWill Drewry 5550d8315ddSYiFei Zhuconfig SECCOMP_CACHE_DEBUG 5560d8315ddSYiFei Zhu bool "Show seccomp filter cache status in /proc/pid/seccomp_cache" 5570d8315ddSYiFei Zhu depends on SECCOMP_FILTER && !HAVE_SPARSE_SYSCALL_NR 5580d8315ddSYiFei Zhu depends on PROC_FS 5590d8315ddSYiFei Zhu help 5600d8315ddSYiFei Zhu This enables the /proc/pid/seccomp_cache interface to monitor 5610d8315ddSYiFei Zhu seccomp cache data. The file format is subject to change. Reading 5620d8315ddSYiFei Zhu the file requires CAP_SYS_ADMIN. 5630d8315ddSYiFei Zhu 5640d8315ddSYiFei Zhu This option is for debugging only. Enabling presents the risk that 5650d8315ddSYiFei Zhu an adversary may be able to infer the seccomp filter logic. 5660d8315ddSYiFei Zhu 5670d8315ddSYiFei Zhu If unsure, say N. 5680d8315ddSYiFei Zhu 569afaef01cSAlexander Popovconfig HAVE_ARCH_STACKLEAK 570afaef01cSAlexander Popov bool 571afaef01cSAlexander Popov help 572afaef01cSAlexander Popov An architecture should select this if it has the code which 573afaef01cSAlexander Popov fills the used part of the kernel stack with the STACKLEAK_POISON 574afaef01cSAlexander Popov value before returning from system calls. 575afaef01cSAlexander Popov 576d148eac0SMasahiro Yamadaconfig HAVE_STACKPROTECTOR 57719952a92SKees Cook bool 57819952a92SKees Cook help 57919952a92SKees Cook An arch should select this symbol if: 58019952a92SKees Cook - it has implemented a stack canary (e.g. __stack_chk_guard) 58119952a92SKees Cook 582050e9baaSLinus Torvaldsconfig STACKPROTECTOR 5832a61f474SMasahiro Yamada bool "Stack Protector buffer overflow detection" 584d148eac0SMasahiro Yamada depends on HAVE_STACKPROTECTOR 5852a61f474SMasahiro Yamada depends on $(cc-option,-fstack-protector) 5862a61f474SMasahiro Yamada default y 5878779657dSKees Cook help 5888779657dSKees Cook This option turns on the "stack-protector" GCC feature. This 58919952a92SKees Cook feature puts, at the beginning of functions, a canary value on 59019952a92SKees Cook the stack just before the return address, and validates 59119952a92SKees Cook the value just before actually returning. Stack based buffer 59219952a92SKees Cook overflows (that need to overwrite this return address) now also 59319952a92SKees Cook overwrite the canary, which gets detected and the attack is then 59419952a92SKees Cook neutralized via a kernel panic. 59519952a92SKees Cook 5968779657dSKees Cook Functions will have the stack-protector canary logic added if they 5978779657dSKees Cook have an 8-byte or larger character array on the stack. 5988779657dSKees Cook 59919952a92SKees Cook This feature requires gcc version 4.2 or above, or a distribution 6008779657dSKees Cook gcc with the feature backported ("-fstack-protector"). 6018779657dSKees Cook 6028779657dSKees Cook On an x86 "defconfig" build, this feature adds canary checks to 6038779657dSKees Cook about 3% of all kernel functions, which increases kernel code size 6048779657dSKees Cook by about 0.3%. 6058779657dSKees Cook 606050e9baaSLinus Torvaldsconfig STACKPROTECTOR_STRONG 6072a61f474SMasahiro Yamada bool "Strong Stack Protector" 608050e9baaSLinus Torvalds depends on STACKPROTECTOR 6092a61f474SMasahiro Yamada depends on $(cc-option,-fstack-protector-strong) 6102a61f474SMasahiro Yamada default y 6118779657dSKees Cook help 6128779657dSKees Cook Functions will have the stack-protector canary logic added in any 6138779657dSKees Cook of the following conditions: 6148779657dSKees Cook 6158779657dSKees Cook - local variable's address used as part of the right hand side of an 6168779657dSKees Cook assignment or function argument 6178779657dSKees Cook - local variable is an array (or union containing an array), 6188779657dSKees Cook regardless of array type or length 6198779657dSKees Cook - uses register local variables 6208779657dSKees Cook 6218779657dSKees Cook This feature requires gcc version 4.9 or above, or a distribution 6228779657dSKees Cook gcc with the feature backported ("-fstack-protector-strong"). 6238779657dSKees Cook 6248779657dSKees Cook On an x86 "defconfig" build, this feature adds canary checks to 6258779657dSKees Cook about 20% of all kernel functions, which increases the kernel code 6268779657dSKees Cook size by about 2%. 6278779657dSKees Cook 628d08b9f0cSSami Tolvanenconfig ARCH_SUPPORTS_SHADOW_CALL_STACK 629d08b9f0cSSami Tolvanen bool 630d08b9f0cSSami Tolvanen help 631afcf5441SDan Li An architecture should select this if it supports the compiler's 632afcf5441SDan Li Shadow Call Stack and implements runtime support for shadow stack 633aa7a65aeSWill Deacon switching. 634d08b9f0cSSami Tolvanen 635d08b9f0cSSami Tolvanenconfig SHADOW_CALL_STACK 636afcf5441SDan Li bool "Shadow Call Stack" 637afcf5441SDan Li depends on ARCH_SUPPORTS_SHADOW_CALL_STACK 638ddc9863eSSami Tolvanen depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER 639d08b9f0cSSami Tolvanen help 640afcf5441SDan Li This option enables the compiler's Shadow Call Stack, which 641afcf5441SDan Li uses a shadow stack to protect function return addresses from 642afcf5441SDan Li being overwritten by an attacker. More information can be found 643afcf5441SDan Li in the compiler's documentation: 644d08b9f0cSSami Tolvanen 645afcf5441SDan Li - Clang: https://clang.llvm.org/docs/ShadowCallStack.html 646afcf5441SDan Li - GCC: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options 647d08b9f0cSSami Tolvanen 648d08b9f0cSSami Tolvanen Note that security guarantees in the kernel differ from the 649d08b9f0cSSami Tolvanen ones documented for user space. The kernel must store addresses 650d08b9f0cSSami Tolvanen of shadow stacks in memory, which means an attacker capable of 651d08b9f0cSSami Tolvanen reading and writing arbitrary memory may be able to locate them 652d08b9f0cSSami Tolvanen and hijack control flow by modifying the stacks. 653d08b9f0cSSami Tolvanen 654dc5723b0SSami Tolvanenconfig LTO 655dc5723b0SSami Tolvanen bool 656dc5723b0SSami Tolvanen help 657dc5723b0SSami Tolvanen Selected if the kernel will be built using the compiler's LTO feature. 658dc5723b0SSami Tolvanen 659dc5723b0SSami Tolvanenconfig LTO_CLANG 660dc5723b0SSami Tolvanen bool 661dc5723b0SSami Tolvanen select LTO 662dc5723b0SSami Tolvanen help 663dc5723b0SSami Tolvanen Selected if the kernel will be built using Clang's LTO feature. 664dc5723b0SSami Tolvanen 665dc5723b0SSami Tolvanenconfig ARCH_SUPPORTS_LTO_CLANG 666dc5723b0SSami Tolvanen bool 667dc5723b0SSami Tolvanen help 668dc5723b0SSami Tolvanen An architecture should select this option if it supports: 669dc5723b0SSami Tolvanen - compiling with Clang, 670dc5723b0SSami Tolvanen - compiling inline assembly with Clang's integrated assembler, 671dc5723b0SSami Tolvanen - and linking with LLD. 672dc5723b0SSami Tolvanen 673dc5723b0SSami Tolvanenconfig ARCH_SUPPORTS_LTO_CLANG_THIN 674dc5723b0SSami Tolvanen bool 675dc5723b0SSami Tolvanen help 676dc5723b0SSami Tolvanen An architecture should select this option if it can support Clang's 677dc5723b0SSami Tolvanen ThinLTO mode. 678dc5723b0SSami Tolvanen 679dc5723b0SSami Tolvanenconfig HAS_LTO_CLANG 680dc5723b0SSami Tolvanen def_bool y 6811e68a8afSNathan Chancellor depends on CC_IS_CLANG && LD_IS_LLD && AS_IS_LLVM 682dc5723b0SSami Tolvanen depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm) 683dc5723b0SSami Tolvanen depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm) 684dc5723b0SSami Tolvanen depends on ARCH_SUPPORTS_LTO_CLANG 685dc5723b0SSami Tolvanen depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT 686bf3c2551SSami Tolvanen depends on !KASAN || KASAN_HW_TAGS 687dc5723b0SSami Tolvanen depends on !GCOV_KERNEL 688dc5723b0SSami Tolvanen help 689dc5723b0SSami Tolvanen The compiler and Kconfig options support building with Clang's 690dc5723b0SSami Tolvanen LTO. 691dc5723b0SSami Tolvanen 692dc5723b0SSami Tolvanenchoice 693dc5723b0SSami Tolvanen prompt "Link Time Optimization (LTO)" 694dc5723b0SSami Tolvanen default LTO_NONE 695dc5723b0SSami Tolvanen help 696dc5723b0SSami Tolvanen This option enables Link Time Optimization (LTO), which allows the 697dc5723b0SSami Tolvanen compiler to optimize binaries globally. 698dc5723b0SSami Tolvanen 699dc5723b0SSami Tolvanen If unsure, select LTO_NONE. Note that LTO is very resource-intensive 700dc5723b0SSami Tolvanen so it's disabled by default. 701dc5723b0SSami Tolvanen 702dc5723b0SSami Tolvanenconfig LTO_NONE 703dc5723b0SSami Tolvanen bool "None" 704dc5723b0SSami Tolvanen help 705dc5723b0SSami Tolvanen Build the kernel normally, without Link Time Optimization (LTO). 706dc5723b0SSami Tolvanen 707dc5723b0SSami Tolvanenconfig LTO_CLANG_FULL 708dc5723b0SSami Tolvanen bool "Clang Full LTO (EXPERIMENTAL)" 709dc5723b0SSami Tolvanen depends on HAS_LTO_CLANG 710dc5723b0SSami Tolvanen depends on !COMPILE_TEST 711dc5723b0SSami Tolvanen select LTO_CLANG 712dc5723b0SSami Tolvanen help 713dc5723b0SSami Tolvanen This option enables Clang's full Link Time Optimization (LTO), which 714dc5723b0SSami Tolvanen allows the compiler to optimize the kernel globally. If you enable 715dc5723b0SSami Tolvanen this option, the compiler generates LLVM bitcode instead of ELF 716dc5723b0SSami Tolvanen object files, and the actual compilation from bitcode happens at 717dc5723b0SSami Tolvanen the LTO link step, which may take several minutes depending on the 718dc5723b0SSami Tolvanen kernel configuration. More information can be found from LLVM's 719dc5723b0SSami Tolvanen documentation: 720dc5723b0SSami Tolvanen 721dc5723b0SSami Tolvanen https://llvm.org/docs/LinkTimeOptimization.html 722dc5723b0SSami Tolvanen 723dc5723b0SSami Tolvanen During link time, this option can use a large amount of RAM, and 724dc5723b0SSami Tolvanen may take much longer than the ThinLTO option. 725dc5723b0SSami Tolvanen 726dc5723b0SSami Tolvanenconfig LTO_CLANG_THIN 727dc5723b0SSami Tolvanen bool "Clang ThinLTO (EXPERIMENTAL)" 728dc5723b0SSami Tolvanen depends on HAS_LTO_CLANG && ARCH_SUPPORTS_LTO_CLANG_THIN 729dc5723b0SSami Tolvanen select LTO_CLANG 730dc5723b0SSami Tolvanen help 731dc5723b0SSami Tolvanen This option enables Clang's ThinLTO, which allows for parallel 732dc5723b0SSami Tolvanen optimization and faster incremental compiles compared to the 733dc5723b0SSami Tolvanen CONFIG_LTO_CLANG_FULL option. More information can be found 734dc5723b0SSami Tolvanen from Clang's documentation: 735dc5723b0SSami Tolvanen 736dc5723b0SSami Tolvanen https://clang.llvm.org/docs/ThinLTO.html 737dc5723b0SSami Tolvanen 738dc5723b0SSami Tolvanen If unsure, say Y. 739dc5723b0SSami Tolvanenendchoice 740dc5723b0SSami Tolvanen 741cf68fffbSSami Tolvanenconfig ARCH_SUPPORTS_CFI_CLANG 742cf68fffbSSami Tolvanen bool 743cf68fffbSSami Tolvanen help 744cf68fffbSSami Tolvanen An architecture should select this option if it can support Clang's 745cf68fffbSSami Tolvanen Control-Flow Integrity (CFI) checking. 746cf68fffbSSami Tolvanen 74789245600SSami Tolvanenconfig ARCH_USES_CFI_TRAPS 74889245600SSami Tolvanen bool 74989245600SSami Tolvanen 750cf68fffbSSami Tolvanenconfig CFI_CLANG 751cf68fffbSSami Tolvanen bool "Use Clang's Control Flow Integrity (CFI)" 75289245600SSami Tolvanen depends on ARCH_SUPPORTS_CFI_CLANG 75389245600SSami Tolvanen depends on $(cc-option,-fsanitize=kcfi) 754cf68fffbSSami Tolvanen help 755cf68fffbSSami Tolvanen This option enables Clang’s forward-edge Control Flow Integrity 756cf68fffbSSami Tolvanen (CFI) checking, where the compiler injects a runtime check to each 757cf68fffbSSami Tolvanen indirect function call to ensure the target is a valid function with 758cf68fffbSSami Tolvanen the correct static type. This restricts possible call targets and 759cf68fffbSSami Tolvanen makes it more difficult for an attacker to exploit bugs that allow 760cf68fffbSSami Tolvanen the modification of stored function pointers. More information can be 761cf68fffbSSami Tolvanen found from Clang's documentation: 762cf68fffbSSami Tolvanen 763cf68fffbSSami Tolvanen https://clang.llvm.org/docs/ControlFlowIntegrity.html 764cf68fffbSSami Tolvanen 765cf68fffbSSami Tolvanenconfig CFI_PERMISSIVE 766cf68fffbSSami Tolvanen bool "Use CFI in permissive mode" 767cf68fffbSSami Tolvanen depends on CFI_CLANG 768cf68fffbSSami Tolvanen help 769cf68fffbSSami Tolvanen When selected, Control Flow Integrity (CFI) violations result in a 770cf68fffbSSami Tolvanen warning instead of a kernel panic. This option should only be used 771cf68fffbSSami Tolvanen for finding indirect call type mismatches during development. 772cf68fffbSSami Tolvanen 773cf68fffbSSami Tolvanen If unsure, say N. 774cf68fffbSSami Tolvanen 7750f60a8efSKees Cookconfig HAVE_ARCH_WITHIN_STACK_FRAMES 7760f60a8efSKees Cook bool 7770f60a8efSKees Cook help 7780f60a8efSKees Cook An architecture should select this if it can walk the kernel stack 7790f60a8efSKees Cook frames to determine if an object is part of either the arguments 7800f60a8efSKees Cook or local variables (i.e. that it excludes saved return addresses, 7810f60a8efSKees Cook and similar) by implementing an inline arch_within_stack_frames(), 7820f60a8efSKees Cook which is used by CONFIG_HARDENED_USERCOPY. 7830f60a8efSKees Cook 78424a9c541SFrederic Weisbeckerconfig HAVE_CONTEXT_TRACKING_USER 7852b1d5024SFrederic Weisbecker bool 7862b1d5024SFrederic Weisbecker help 78791d1aa43SFrederic Weisbecker Provide kernel/user boundaries probes necessary for subsystems 78891d1aa43SFrederic Weisbecker that need it, such as userspace RCU extended quiescent state. 789490f561bSFrederic Weisbecker Syscalls need to be wrapped inside user_exit()-user_enter(), either 790490f561bSFrederic Weisbecker optimized behind static key or through the slow path using TIF_NOHZ 791490f561bSFrederic Weisbecker flag. Exceptions handlers must be wrapped as well. Irqs are already 7926f0e6c15SFrederic Weisbecker protected inside ct_irq_enter/ct_irq_exit() but preemption or signal 793490f561bSFrederic Weisbecker handling on irq exit still need to be protected. 794490f561bSFrederic Weisbecker 79524a9c541SFrederic Weisbeckerconfig HAVE_CONTEXT_TRACKING_USER_OFFSTACK 79683c2da2eSFrederic Weisbecker bool 79783c2da2eSFrederic Weisbecker help 79883c2da2eSFrederic Weisbecker Architecture neither relies on exception_enter()/exception_exit() 79983c2da2eSFrederic Weisbecker nor on schedule_user(). Also preempt_schedule_notrace() and 80083c2da2eSFrederic Weisbecker preempt_schedule_irq() can't be called in a preemptible section 80183c2da2eSFrederic Weisbecker while context tracking is CONTEXT_USER. This feature reflects a sane 80283c2da2eSFrederic Weisbecker entry implementation where the following requirements are met on 80383c2da2eSFrederic Weisbecker critical entry code, ie: before user_exit() or after user_enter(): 80483c2da2eSFrederic Weisbecker 80583c2da2eSFrederic Weisbecker - Critical entry code isn't preemptible (or better yet: 80683c2da2eSFrederic Weisbecker not interruptible). 807493c1822SFrederic Weisbecker - No use of RCU read side critical sections, unless ct_nmi_enter() 80883c2da2eSFrederic Weisbecker got called. 80983c2da2eSFrederic Weisbecker - No use of instrumentation, unless instrumentation_begin() got 81083c2da2eSFrederic Weisbecker called. 81183c2da2eSFrederic Weisbecker 812490f561bSFrederic Weisbeckerconfig HAVE_TIF_NOHZ 813490f561bSFrederic Weisbecker bool 814490f561bSFrederic Weisbecker help 815490f561bSFrederic Weisbecker Arch relies on TIF_NOHZ and syscall slow path to implement context 816490f561bSFrederic Weisbecker tracking calls to user_enter()/user_exit(). 8172b1d5024SFrederic Weisbecker 818b952741cSFrederic Weisbeckerconfig HAVE_VIRT_CPU_ACCOUNTING 819b952741cSFrederic Weisbecker bool 820b952741cSFrederic Weisbecker 8212b91ec9fSFrederic Weisbeckerconfig HAVE_VIRT_CPU_ACCOUNTING_IDLE 8222b91ec9fSFrederic Weisbecker bool 8232b91ec9fSFrederic Weisbecker help 8242b91ec9fSFrederic Weisbecker Architecture has its own way to account idle CPU time and therefore 8252b91ec9fSFrederic Weisbecker doesn't implement vtime_account_idle(). 8262b91ec9fSFrederic Weisbecker 82740565b5aSStanislaw Gruszkaconfig ARCH_HAS_SCALED_CPUTIME 82840565b5aSStanislaw Gruszka bool 82940565b5aSStanislaw Gruszka 830554b0004SKevin Hilmanconfig HAVE_VIRT_CPU_ACCOUNTING_GEN 831554b0004SKevin Hilman bool 832554b0004SKevin Hilman default y if 64BIT 833554b0004SKevin Hilman help 834554b0004SKevin Hilman With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit. 835554b0004SKevin Hilman Before enabling this option, arch code must be audited 836554b0004SKevin Hilman to ensure there are no races in concurrent read/write of 837554b0004SKevin Hilman cputime_t. For example, reading/writing 64-bit cputime_t on 838554b0004SKevin Hilman some 32-bit arches may require multiple accesses, so proper 839554b0004SKevin Hilman locking is needed to protect against concurrent accesses. 840554b0004SKevin Hilman 841fdf9c356SFrederic Weisbeckerconfig HAVE_IRQ_TIME_ACCOUNTING 842fdf9c356SFrederic Weisbecker bool 843fdf9c356SFrederic Weisbecker help 844fdf9c356SFrederic Weisbecker Archs need to ensure they use a high enough resolution clock to 845fdf9c356SFrederic Weisbecker support irq time accounting and then call enable_sched_clock_irqtime(). 846fdf9c356SFrederic Weisbecker 847c49dd340SKalesh Singhconfig HAVE_MOVE_PUD 848c49dd340SKalesh Singh bool 849c49dd340SKalesh Singh help 850c49dd340SKalesh Singh Architectures that select this are able to move page tables at the 851c49dd340SKalesh Singh PUD level. If there are only 3 page table levels, the move effectively 852c49dd340SKalesh Singh happens at the PGD level. 853c49dd340SKalesh Singh 8542c91bd4aSJoel Fernandes (Google)config HAVE_MOVE_PMD 8552c91bd4aSJoel Fernandes (Google) bool 8562c91bd4aSJoel Fernandes (Google) help 8572c91bd4aSJoel Fernandes (Google) Archs that select this are able to move page tables at the PMD level. 8582c91bd4aSJoel Fernandes (Google) 85915626062SGerald Schaeferconfig HAVE_ARCH_TRANSPARENT_HUGEPAGE 86015626062SGerald Schaefer bool 86115626062SGerald Schaefer 862a00cc7d9SMatthew Wilcoxconfig HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 863a00cc7d9SMatthew Wilcox bool 864a00cc7d9SMatthew Wilcox 8650ddab1d2SToshi Kaniconfig HAVE_ARCH_HUGE_VMAP 8660ddab1d2SToshi Kani bool 8670ddab1d2SToshi Kani 868121e6f32SNicholas Piggin# 869121e6f32SNicholas Piggin# Archs that select this would be capable of PMD-sized vmaps (i.e., 870559089e0SSong Liu# arch_vmap_pmd_supported() returns true). The VM_ALLOW_HUGE_VMAP flag 871559089e0SSong Liu# must be used to enable allocations to use hugepages. 872121e6f32SNicholas Piggin# 873121e6f32SNicholas Pigginconfig HAVE_ARCH_HUGE_VMALLOC 874121e6f32SNicholas Piggin depends on HAVE_ARCH_HUGE_VMAP 875121e6f32SNicholas Piggin bool 876121e6f32SNicholas Piggin 8773876d4a3SAlexandre Ghiticonfig ARCH_WANT_HUGE_PMD_SHARE 8783876d4a3SAlexandre Ghiti bool 8793876d4a3SAlexandre Ghiti 8800f8975ecSPavel Emelyanovconfig HAVE_ARCH_SOFT_DIRTY 8810f8975ecSPavel Emelyanov bool 8820f8975ecSPavel Emelyanov 883786d35d4SDavid Howellsconfig HAVE_MOD_ARCH_SPECIFIC 884786d35d4SDavid Howells bool 885786d35d4SDavid Howells help 886786d35d4SDavid Howells The arch uses struct mod_arch_specific to store data. Many arches 887786d35d4SDavid Howells just need a simple module loader without arch specific data - those 888786d35d4SDavid Howells should not enable this. 889786d35d4SDavid Howells 890786d35d4SDavid Howellsconfig MODULES_USE_ELF_RELA 891786d35d4SDavid Howells bool 892786d35d4SDavid Howells help 893786d35d4SDavid Howells Modules only use ELF RELA relocations. Modules with ELF REL 894786d35d4SDavid Howells relocations will give an error. 895786d35d4SDavid Howells 896786d35d4SDavid Howellsconfig MODULES_USE_ELF_REL 897786d35d4SDavid Howells bool 898786d35d4SDavid Howells help 899786d35d4SDavid Howells Modules only use ELF REL relocations. Modules with ELF RELA 900786d35d4SDavid Howells relocations will give an error. 901786d35d4SDavid Howells 90201dc0386SChristophe Leroyconfig ARCH_WANTS_MODULES_DATA_IN_VMALLOC 90301dc0386SChristophe Leroy bool 90401dc0386SChristophe Leroy help 90501dc0386SChristophe Leroy For architectures like powerpc/32 which have constraints on module 90601dc0386SChristophe Leroy allocation and need to allocate module data outside of module area. 90701dc0386SChristophe Leroy 908cc1f0274SFrederic Weisbeckerconfig HAVE_IRQ_EXIT_ON_IRQ_STACK 909cc1f0274SFrederic Weisbecker bool 910cc1f0274SFrederic Weisbecker help 911cc1f0274SFrederic Weisbecker Architecture doesn't only execute the irq handler on the irq stack 912cc1f0274SFrederic Weisbecker but also irq_exit(). This way we can process softirqs on this irq 913cc1f0274SFrederic Weisbecker stack instead of switching to a new one when we call __do_softirq() 914cc1f0274SFrederic Weisbecker in the end of an hardirq. 915cc1f0274SFrederic Weisbecker This spares a stack switch and improves cache usage on softirq 916cc1f0274SFrederic Weisbecker processing. 917cc1f0274SFrederic Weisbecker 918cd1a41ceSThomas Gleixnerconfig HAVE_SOFTIRQ_ON_OWN_STACK 919cd1a41ceSThomas Gleixner bool 920cd1a41ceSThomas Gleixner help 921cd1a41ceSThomas Gleixner Architecture provides a function to run __do_softirq() on a 922c226bc3cSColin Ian King separate stack. 923cd1a41ceSThomas Gleixner 9248cbb2b50SSebastian Andrzej Siewiorconfig SOFTIRQ_ON_OWN_STACK 9258cbb2b50SSebastian Andrzej Siewior def_bool HAVE_SOFTIRQ_ON_OWN_STACK && !PREEMPT_RT 9268cbb2b50SSebastian Andrzej Siewior 92712700c17SArnd Bergmannconfig ALTERNATE_USER_ADDRESS_SPACE 92812700c17SArnd Bergmann bool 92912700c17SArnd Bergmann help 93012700c17SArnd Bergmann Architectures set this when the CPU uses separate address 93112700c17SArnd Bergmann spaces for kernel and user space pointers. In this case, the 93212700c17SArnd Bergmann access_ok() check on a __user pointer is skipped. 93312700c17SArnd Bergmann 934235a8f02SKirill A. Shutemovconfig PGTABLE_LEVELS 935235a8f02SKirill A. Shutemov int 936235a8f02SKirill A. Shutemov default 2 937235a8f02SKirill A. Shutemov 9382b68f6caSKees Cookconfig ARCH_HAS_ELF_RANDOMIZE 9392b68f6caSKees Cook bool 9402b68f6caSKees Cook help 9412b68f6caSKees Cook An architecture supports choosing randomized locations for 9422b68f6caSKees Cook stack, mmap, brk, and ET_DYN. Defined functions: 9432b68f6caSKees Cook - arch_mmap_rnd() 944204db6edSKees Cook - arch_randomize_brk() 9452b68f6caSKees Cook 946d07e2259SDaniel Cashmanconfig HAVE_ARCH_MMAP_RND_BITS 947d07e2259SDaniel Cashman bool 948d07e2259SDaniel Cashman help 949d07e2259SDaniel Cashman An arch should select this symbol if it supports setting a variable 950d07e2259SDaniel Cashman number of bits for use in establishing the base address for mmap 951d07e2259SDaniel Cashman allocations, has MMU enabled and provides values for both: 952d07e2259SDaniel Cashman - ARCH_MMAP_RND_BITS_MIN 953d07e2259SDaniel Cashman - ARCH_MMAP_RND_BITS_MAX 954d07e2259SDaniel Cashman 9555f56a5dfSJiri Slabyconfig HAVE_EXIT_THREAD 9565f56a5dfSJiri Slaby bool 9575f56a5dfSJiri Slaby help 9585f56a5dfSJiri Slaby An architecture implements exit_thread. 9595f56a5dfSJiri Slaby 960d07e2259SDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MIN 961d07e2259SDaniel Cashman int 962d07e2259SDaniel Cashman 963d07e2259SDaniel Cashmanconfig ARCH_MMAP_RND_BITS_MAX 964d07e2259SDaniel Cashman int 965d07e2259SDaniel Cashman 966d07e2259SDaniel Cashmanconfig ARCH_MMAP_RND_BITS_DEFAULT 967d07e2259SDaniel Cashman int 968d07e2259SDaniel Cashman 969d07e2259SDaniel Cashmanconfig ARCH_MMAP_RND_BITS 970d07e2259SDaniel Cashman int "Number of bits to use for ASLR of mmap base address" if EXPERT 971d07e2259SDaniel Cashman range ARCH_MMAP_RND_BITS_MIN ARCH_MMAP_RND_BITS_MAX 972d07e2259SDaniel Cashman default ARCH_MMAP_RND_BITS_DEFAULT if ARCH_MMAP_RND_BITS_DEFAULT 973d07e2259SDaniel Cashman default ARCH_MMAP_RND_BITS_MIN 974d07e2259SDaniel Cashman depends on HAVE_ARCH_MMAP_RND_BITS 975d07e2259SDaniel Cashman help 976d07e2259SDaniel Cashman This value can be used to select the number of bits to use to 977d07e2259SDaniel Cashman determine the random offset to the base address of vma regions 978d07e2259SDaniel Cashman resulting from mmap allocations. This value will be bounded 979d07e2259SDaniel Cashman by the architecture's minimum and maximum supported values. 980d07e2259SDaniel Cashman 981d07e2259SDaniel Cashman This value can be changed after boot using the 982d07e2259SDaniel Cashman /proc/sys/vm/mmap_rnd_bits tunable 983d07e2259SDaniel Cashman 984d07e2259SDaniel Cashmanconfig HAVE_ARCH_MMAP_RND_COMPAT_BITS 985d07e2259SDaniel Cashman bool 986d07e2259SDaniel Cashman help 987d07e2259SDaniel Cashman An arch should select this symbol if it supports running applications 988d07e2259SDaniel Cashman in compatibility mode, supports setting a variable number of bits for 989d07e2259SDaniel Cashman use in establishing the base address for mmap allocations, has MMU 990d07e2259SDaniel Cashman enabled and provides values for both: 991d07e2259SDaniel Cashman - ARCH_MMAP_RND_COMPAT_BITS_MIN 992d07e2259SDaniel Cashman - ARCH_MMAP_RND_COMPAT_BITS_MAX 993d07e2259SDaniel Cashman 994d07e2259SDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MIN 995d07e2259SDaniel Cashman int 996d07e2259SDaniel Cashman 997d07e2259SDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_MAX 998d07e2259SDaniel Cashman int 999d07e2259SDaniel Cashman 1000d07e2259SDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS_DEFAULT 1001d07e2259SDaniel Cashman int 1002d07e2259SDaniel Cashman 1003d07e2259SDaniel Cashmanconfig ARCH_MMAP_RND_COMPAT_BITS 1004d07e2259SDaniel Cashman int "Number of bits to use for ASLR of mmap base address for compatible applications" if EXPERT 1005d07e2259SDaniel Cashman range ARCH_MMAP_RND_COMPAT_BITS_MIN ARCH_MMAP_RND_COMPAT_BITS_MAX 1006d07e2259SDaniel Cashman default ARCH_MMAP_RND_COMPAT_BITS_DEFAULT if ARCH_MMAP_RND_COMPAT_BITS_DEFAULT 1007d07e2259SDaniel Cashman default ARCH_MMAP_RND_COMPAT_BITS_MIN 1008d07e2259SDaniel Cashman depends on HAVE_ARCH_MMAP_RND_COMPAT_BITS 1009d07e2259SDaniel Cashman help 1010d07e2259SDaniel Cashman This value can be used to select the number of bits to use to 1011d07e2259SDaniel Cashman determine the random offset to the base address of vma regions 1012d07e2259SDaniel Cashman resulting from mmap allocations for compatible applications This 1013d07e2259SDaniel Cashman value will be bounded by the architecture's minimum and maximum 1014d07e2259SDaniel Cashman supported values. 1015d07e2259SDaniel Cashman 1016d07e2259SDaniel Cashman This value can be changed after boot using the 1017d07e2259SDaniel Cashman /proc/sys/vm/mmap_rnd_compat_bits tunable 1018d07e2259SDaniel Cashman 10191b028f78SDmitry Safonovconfig HAVE_ARCH_COMPAT_MMAP_BASES 10201b028f78SDmitry Safonov bool 10211b028f78SDmitry Safonov help 10221b028f78SDmitry Safonov This allows 64bit applications to invoke 32-bit mmap() syscall 10231b028f78SDmitry Safonov and vice-versa 32-bit applications to call 64-bit mmap(). 10241b028f78SDmitry Safonov Required for applications doing different bitness syscalls. 10251b028f78SDmitry Safonov 10261f0e290cSGuenter Roeckconfig PAGE_SIZE_LESS_THAN_64KB 10271f0e290cSGuenter Roeck def_bool y 10281f0e290cSGuenter Roeck depends on !ARM64_64K_PAGES 10291f0e290cSGuenter Roeck depends on !IA64_PAGE_SIZE_64KB 10301f0e290cSGuenter Roeck depends on !PAGE_SIZE_64KB 10311f0e290cSGuenter Roeck depends on !PARISC_PAGE_SIZE_64KB 1032e4bbd20dSNathan Chancellor depends on PAGE_SIZE_LESS_THAN_256KB 1033e4bbd20dSNathan Chancellor 1034e4bbd20dSNathan Chancellorconfig PAGE_SIZE_LESS_THAN_256KB 1035e4bbd20dSNathan Chancellor def_bool y 10361f0e290cSGuenter Roeck depends on !PAGE_SIZE_256KB 10371f0e290cSGuenter Roeck 103867f3977fSAlexandre Ghiti# This allows to use a set of generic functions to determine mmap base 103967f3977fSAlexandre Ghiti# address by giving priority to top-down scheme only if the process 104067f3977fSAlexandre Ghiti# is not in legacy mode (compat task, unlimited stack size or 104167f3977fSAlexandre Ghiti# sysctl_legacy_va_layout). 104267f3977fSAlexandre Ghiti# Architecture that selects this option can provide its own version of: 104367f3977fSAlexandre Ghiti# - STACK_RND_MASK 104467f3977fSAlexandre Ghiticonfig ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 104567f3977fSAlexandre Ghiti bool 104667f3977fSAlexandre Ghiti depends on MMU 1047e7142bf5SAlexandre Ghiti select ARCH_HAS_ELF_RANDOMIZE 104867f3977fSAlexandre Ghiti 104903f16cd0SJosh Poimboeufconfig HAVE_OBJTOOL 105003f16cd0SJosh Poimboeuf bool 105103f16cd0SJosh Poimboeuf 10524ab7674fSJosh Poimboeufconfig HAVE_JUMP_LABEL_HACK 10534ab7674fSJosh Poimboeuf bool 10544ab7674fSJosh Poimboeuf 105522102f45SJosh Poimboeufconfig HAVE_NOINSTR_HACK 105622102f45SJosh Poimboeuf bool 105722102f45SJosh Poimboeuf 1058489e355bSJosh Poimboeufconfig HAVE_NOINSTR_VALIDATION 1059489e355bSJosh Poimboeuf bool 1060489e355bSJosh Poimboeuf 10615f3da8c0SJosh Poimboeufconfig HAVE_UACCESS_VALIDATION 10625f3da8c0SJosh Poimboeuf bool 10635f3da8c0SJosh Poimboeuf select OBJTOOL 10645f3da8c0SJosh Poimboeuf 1065b9ab5ebbSJosh Poimboeufconfig HAVE_STACK_VALIDATION 1066b9ab5ebbSJosh Poimboeuf bool 1067b9ab5ebbSJosh Poimboeuf help 106803f16cd0SJosh Poimboeuf Architecture supports objtool compile-time frame pointer rule 106903f16cd0SJosh Poimboeuf validation. 1070b9ab5ebbSJosh Poimboeuf 1071af085d90SJosh Poimboeufconfig HAVE_RELIABLE_STACKTRACE 1072af085d90SJosh Poimboeuf bool 1073af085d90SJosh Poimboeuf help 1074140d7e88SMiroslav Benes Architecture has either save_stack_trace_tsk_reliable() or 1075140d7e88SMiroslav Benes arch_stack_walk_reliable() function which only returns a stack trace 1076140d7e88SMiroslav Benes if it can guarantee the trace is reliable. 1077af085d90SJosh Poimboeuf 1078468a9428SGeorge Spelvinconfig HAVE_ARCH_HASH 1079468a9428SGeorge Spelvin bool 1080468a9428SGeorge Spelvin default n 1081468a9428SGeorge Spelvin help 1082468a9428SGeorge Spelvin If this is set, the architecture provides an <asm/hash.h> 1083468a9428SGeorge Spelvin file which provides platform-specific implementations of some 1084468a9428SGeorge Spelvin functions in <linux/hash.h> or fs/namei.c. 1085468a9428SGeorge Spelvin 1086666047feSFinn Thainconfig HAVE_ARCH_NVRAM_OPS 1087666047feSFinn Thain bool 1088666047feSFinn Thain 10893a495511SWilliam Breathitt Grayconfig ISA_BUS_API 10903a495511SWilliam Breathitt Gray def_bool ISA 10913a495511SWilliam Breathitt Gray 1092d2125043SAl Viro# 1093d2125043SAl Viro# ABI hall of shame 1094d2125043SAl Viro# 1095d2125043SAl Viroconfig CLONE_BACKWARDS 1096d2125043SAl Viro bool 1097d2125043SAl Viro help 1098d2125043SAl Viro Architecture has tls passed as the 4th argument of clone(2), 1099d2125043SAl Viro not the 5th one. 1100d2125043SAl Viro 1101d2125043SAl Viroconfig CLONE_BACKWARDS2 1102d2125043SAl Viro bool 1103d2125043SAl Viro help 1104d2125043SAl Viro Architecture has the first two arguments of clone(2) swapped. 1105d2125043SAl Viro 1106dfa9771aSMichal Simekconfig CLONE_BACKWARDS3 1107dfa9771aSMichal Simek bool 1108dfa9771aSMichal Simek help 1109dfa9771aSMichal Simek Architecture has tls passed as the 3rd argument of clone(2), 1110dfa9771aSMichal Simek not the 5th one. 1111dfa9771aSMichal Simek 1112eaca6eaeSAl Viroconfig ODD_RT_SIGACTION 1113eaca6eaeSAl Viro bool 1114eaca6eaeSAl Viro help 1115eaca6eaeSAl Viro Architecture has unusual rt_sigaction(2) arguments 1116eaca6eaeSAl Viro 11170a0e8cdfSAl Viroconfig OLD_SIGSUSPEND 11180a0e8cdfSAl Viro bool 11190a0e8cdfSAl Viro help 11200a0e8cdfSAl Viro Architecture has old sigsuspend(2) syscall, of one-argument variety 11210a0e8cdfSAl Viro 11220a0e8cdfSAl Viroconfig OLD_SIGSUSPEND3 11230a0e8cdfSAl Viro bool 11240a0e8cdfSAl Viro help 11250a0e8cdfSAl Viro Even weirder antique ABI - three-argument sigsuspend(2) 11260a0e8cdfSAl Viro 1127495dfbf7SAl Viroconfig OLD_SIGACTION 1128495dfbf7SAl Viro bool 1129495dfbf7SAl Viro help 1130495dfbf7SAl Viro Architecture has old sigaction(2) syscall. Nope, not the same 1131495dfbf7SAl Viro as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2), 1132495dfbf7SAl Viro but fairly different variant of sigaction(2), thanks to OSF/1 1133495dfbf7SAl Viro compatibility... 1134495dfbf7SAl Viro 1135495dfbf7SAl Viroconfig COMPAT_OLD_SIGACTION 1136495dfbf7SAl Viro bool 1137495dfbf7SAl Viro 113817435e5fSDeepa Dinamaniconfig COMPAT_32BIT_TIME 1139942437c9SArnd Bergmann bool "Provide system calls for 32-bit time_t" 1140942437c9SArnd Bergmann default !64BIT || COMPAT 114117435e5fSDeepa Dinamani help 114217435e5fSDeepa Dinamani This enables 32 bit time_t support in addition to 64 bit time_t support. 114317435e5fSDeepa Dinamani This is relevant on all 32-bit architectures, and 64-bit architectures 114417435e5fSDeepa Dinamani as part of compat syscall handling. 114517435e5fSDeepa Dinamani 114687a4c375SChristoph Hellwigconfig ARCH_NO_PREEMPT 114787a4c375SChristoph Hellwig bool 114887a4c375SChristoph Hellwig 1149cb2c7d1aSMickaël Salaünconfig ARCH_EPHEMERAL_INODES 1150cb2c7d1aSMickaël Salaün def_bool n 1151cb2c7d1aSMickaël Salaün help 1152cb2c7d1aSMickaël Salaün An arch should select this symbol if it doesn't keep track of inode 1153cb2c7d1aSMickaël Salaün instances on its own, but instead relies on something else (e.g. the 1154cb2c7d1aSMickaël Salaün host kernel for an UML kernel). 1155cb2c7d1aSMickaël Salaün 1156a50a3f4bSThomas Gleixnerconfig ARCH_SUPPORTS_RT 1157a50a3f4bSThomas Gleixner bool 1158a50a3f4bSThomas Gleixner 1159fff7fb0bSZhaoxiu Zengconfig CPU_NO_EFFICIENT_FFS 1160fff7fb0bSZhaoxiu Zeng def_bool n 1161fff7fb0bSZhaoxiu Zeng 1162ba14a194SAndy Lutomirskiconfig HAVE_ARCH_VMAP_STACK 1163ba14a194SAndy Lutomirski def_bool n 1164ba14a194SAndy Lutomirski help 1165ba14a194SAndy Lutomirski An arch should select this symbol if it can support kernel stacks 1166ba14a194SAndy Lutomirski in vmalloc space. This means: 1167ba14a194SAndy Lutomirski 1168ba14a194SAndy Lutomirski - vmalloc space must be large enough to hold many kernel stacks. 1169ba14a194SAndy Lutomirski This may rule out many 32-bit architectures. 1170ba14a194SAndy Lutomirski 1171ba14a194SAndy Lutomirski - Stacks in vmalloc space need to work reliably. For example, if 1172ba14a194SAndy Lutomirski vmap page tables are created on demand, either this mechanism 1173ba14a194SAndy Lutomirski needs to work while the stack points to a virtual address with 1174ba14a194SAndy Lutomirski unpopulated page tables or arch code (switch_to() and switch_mm(), 1175ba14a194SAndy Lutomirski most likely) needs to ensure that the stack's page table entries 1176ba14a194SAndy Lutomirski are populated before running on a possibly unpopulated stack. 1177ba14a194SAndy Lutomirski 1178ba14a194SAndy Lutomirski - If the stack overflows into a guard page, something reasonable 1179ba14a194SAndy Lutomirski should happen. The definition of "reasonable" is flexible, but 1180ba14a194SAndy Lutomirski instantly rebooting without logging anything would be unfriendly. 1181ba14a194SAndy Lutomirski 1182ba14a194SAndy Lutomirskiconfig VMAP_STACK 1183ba14a194SAndy Lutomirski default y 1184ba14a194SAndy Lutomirski bool "Use a virtually-mapped stack" 1185eafb149eSDaniel Axtens depends on HAVE_ARCH_VMAP_STACK 118638dd767dSAndrey Konovalov depends on !KASAN || KASAN_HW_TAGS || KASAN_VMALLOC 1187a7f7f624SMasahiro Yamada help 1188ba14a194SAndy Lutomirski Enable this if you want the use virtually-mapped kernel stacks 1189ba14a194SAndy Lutomirski with guard pages. This causes kernel stack overflows to be 1190ba14a194SAndy Lutomirski caught immediately rather than causing difficult-to-diagnose 1191ba14a194SAndy Lutomirski corruption. 1192ba14a194SAndy Lutomirski 119338dd767dSAndrey Konovalov To use this with software KASAN modes, the architecture must support 119438dd767dSAndrey Konovalov backing virtual mappings with real shadow memory, and KASAN_VMALLOC 119538dd767dSAndrey Konovalov must be enabled. 1196ba14a194SAndy Lutomirski 119739218ff4SKees Cookconfig HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 119839218ff4SKees Cook def_bool n 119939218ff4SKees Cook help 120039218ff4SKees Cook An arch should select this symbol if it can support kernel stack 120139218ff4SKees Cook offset randomization with calls to add_random_kstack_offset() 120239218ff4SKees Cook during syscall entry and choose_random_kstack_offset() during 120339218ff4SKees Cook syscall exit. Careful removal of -fstack-protector-strong and 120439218ff4SKees Cook -fstack-protector should also be applied to the entry code and 120539218ff4SKees Cook closely examined, as the artificial stack bump looks like an array 120639218ff4SKees Cook to the compiler, so it will attempt to add canary checks regardless 120739218ff4SKees Cook of the static branch state. 120839218ff4SKees Cook 12098cb37a59SMarco Elverconfig RANDOMIZE_KSTACK_OFFSET 12108cb37a59SMarco Elver bool "Support for randomizing kernel stack offset on syscall entry" if EXPERT 12118cb37a59SMarco Elver default y 121239218ff4SKees Cook depends on HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 1213efa90c11SMarco Elver depends on INIT_STACK_NONE || !CC_IS_CLANG || CLANG_VERSION >= 140000 121439218ff4SKees Cook help 121539218ff4SKees Cook The kernel stack offset can be randomized (after pt_regs) by 121639218ff4SKees Cook roughly 5 bits of entropy, frustrating memory corruption 121739218ff4SKees Cook attacks that depend on stack address determinism or 12188cb37a59SMarco Elver cross-syscall address exposures. 12198cb37a59SMarco Elver 12208cb37a59SMarco Elver The feature is controlled via the "randomize_kstack_offset=on/off" 12218cb37a59SMarco Elver kernel boot param, and if turned off has zero overhead due to its use 12228cb37a59SMarco Elver of static branches (see JUMP_LABEL). 12238cb37a59SMarco Elver 12248cb37a59SMarco Elver If unsure, say Y. 12258cb37a59SMarco Elver 12268cb37a59SMarco Elverconfig RANDOMIZE_KSTACK_OFFSET_DEFAULT 12278cb37a59SMarco Elver bool "Default state of kernel stack offset randomization" 12288cb37a59SMarco Elver depends on RANDOMIZE_KSTACK_OFFSET 12298cb37a59SMarco Elver help 12308cb37a59SMarco Elver Kernel stack offset randomization is controlled by kernel boot param 12318cb37a59SMarco Elver "randomize_kstack_offset=on/off", and this config chooses the default 12328cb37a59SMarco Elver boot state. 123339218ff4SKees Cook 1234ad21fc4fSLaura Abbottconfig ARCH_OPTIONAL_KERNEL_RWX 1235ad21fc4fSLaura Abbott def_bool n 1236ad21fc4fSLaura Abbott 1237ad21fc4fSLaura Abbottconfig ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 1238ad21fc4fSLaura Abbott def_bool n 1239ad21fc4fSLaura Abbott 1240ad21fc4fSLaura Abbottconfig ARCH_HAS_STRICT_KERNEL_RWX 1241ad21fc4fSLaura Abbott def_bool n 1242ad21fc4fSLaura Abbott 12430f5bf6d0SLaura Abbottconfig STRICT_KERNEL_RWX 1244ad21fc4fSLaura Abbott bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX 1245ad21fc4fSLaura Abbott depends on ARCH_HAS_STRICT_KERNEL_RWX 1246ad21fc4fSLaura Abbott default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 1247ad21fc4fSLaura Abbott help 1248ad21fc4fSLaura Abbott If this is set, kernel text and rodata memory will be made read-only, 1249ad21fc4fSLaura Abbott and non-text memory will be made non-executable. This provides 1250ad21fc4fSLaura Abbott protection against certain security exploits (e.g. executing the heap 1251ad21fc4fSLaura Abbott or modifying text) 1252ad21fc4fSLaura Abbott 1253ad21fc4fSLaura Abbott These features are considered standard security practice these days. 1254ad21fc4fSLaura Abbott You should say Y here in almost all cases. 1255ad21fc4fSLaura Abbott 1256ad21fc4fSLaura Abbottconfig ARCH_HAS_STRICT_MODULE_RWX 1257ad21fc4fSLaura Abbott def_bool n 1258ad21fc4fSLaura Abbott 12590f5bf6d0SLaura Abbottconfig STRICT_MODULE_RWX 1260ad21fc4fSLaura Abbott bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX 1261ad21fc4fSLaura Abbott depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES 1262ad21fc4fSLaura Abbott default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 1263ad21fc4fSLaura Abbott help 1264ad21fc4fSLaura Abbott If this is set, module text and rodata memory will be made read-only, 1265ad21fc4fSLaura Abbott and non-text memory will be made non-executable. This provides 1266ad21fc4fSLaura Abbott protection against certain security exploits (e.g. writing to text) 1267ad21fc4fSLaura Abbott 1268ea8c64acSChristoph Hellwig# select if the architecture provides an asm/dma-direct.h header 1269ea8c64acSChristoph Hellwigconfig ARCH_HAS_PHYS_TO_DMA 1270ea8c64acSChristoph Hellwig bool 1271ea8c64acSChristoph Hellwig 127204f264d3SPaul Burtonconfig HAVE_ARCH_COMPILER_H 127304f264d3SPaul Burton bool 127404f264d3SPaul Burton help 127504f264d3SPaul Burton An architecture can select this if it provides an 127604f264d3SPaul Burton asm/compiler.h header that should be included after 127704f264d3SPaul Burton linux/compiler-*.h in order to override macro definitions that those 127804f264d3SPaul Burton headers generally provide. 127904f264d3SPaul Burton 1280271ca788SArd Biesheuvelconfig HAVE_ARCH_PREL32_RELOCATIONS 1281271ca788SArd Biesheuvel bool 1282271ca788SArd Biesheuvel help 1283271ca788SArd Biesheuvel May be selected by an architecture if it supports place-relative 1284271ca788SArd Biesheuvel 32-bit relocations, both in the toolchain and in the module loader, 1285271ca788SArd Biesheuvel in which case relative references can be used in special sections 1286271ca788SArd Biesheuvel for PCI fixup, initcalls etc which are only half the size on 64 bit 1287271ca788SArd Biesheuvel architectures, and don't require runtime relocation on relocatable 1288271ca788SArd Biesheuvel kernels. 1289271ca788SArd Biesheuvel 1290ce9084baSArd Biesheuvelconfig ARCH_USE_MEMREMAP_PROT 1291ce9084baSArd Biesheuvel bool 1292ce9084baSArd Biesheuvel 1293fb346fd9SWaiman Longconfig LOCK_EVENT_COUNTS 1294fb346fd9SWaiman Long bool "Locking event counts collection" 1295fb346fd9SWaiman Long depends on DEBUG_FS 1296a7f7f624SMasahiro Yamada help 1297fb346fd9SWaiman Long Enable light-weight counting of various locking related events 1298fb346fd9SWaiman Long in the system with minimal performance impact. This reduces 1299fb346fd9SWaiman Long the chance of application behavior change because of timing 1300fb346fd9SWaiman Long differences. The counts are reported via debugfs. 1301fb346fd9SWaiman Long 13025cf896fbSPeter Collingbourne# Select if the architecture has support for applying RELR relocations. 13035cf896fbSPeter Collingbourneconfig ARCH_HAS_RELR 13045cf896fbSPeter Collingbourne bool 13055cf896fbSPeter Collingbourne 13065cf896fbSPeter Collingbourneconfig RELR 13075cf896fbSPeter Collingbourne bool "Use RELR relocation packing" 13085cf896fbSPeter Collingbourne depends on ARCH_HAS_RELR && TOOLS_SUPPORT_RELR 13095cf896fbSPeter Collingbourne default y 13105cf896fbSPeter Collingbourne help 13115cf896fbSPeter Collingbourne Store the kernel's dynamic relocations in the RELR relocation packing 13125cf896fbSPeter Collingbourne format. Requires a compatible linker (LLD supports this feature), as 13135cf896fbSPeter Collingbourne well as compatible NM and OBJCOPY utilities (llvm-nm and llvm-objcopy 13145cf896fbSPeter Collingbourne are compatible). 13155cf896fbSPeter Collingbourne 13160c9c1d56SThiago Jung Bauermannconfig ARCH_HAS_MEM_ENCRYPT 13170c9c1d56SThiago Jung Bauermann bool 13180c9c1d56SThiago Jung Bauermann 131946b49b12STom Lendackyconfig ARCH_HAS_CC_PLATFORM 132046b49b12STom Lendacky bool 132146b49b12STom Lendacky 13220e242208SHassan Naveedconfig HAVE_SPARSE_SYSCALL_NR 13230e242208SHassan Naveed bool 13240e242208SHassan Naveed help 13250e242208SHassan Naveed An architecture should select this if its syscall numbering is sparse 13260e242208SHassan Naveed to save space. For example, MIPS architecture has a syscall array with 13270e242208SHassan Naveed entries at 4000, 5000 and 6000 locations. This option turns on syscall 13280e242208SHassan Naveed related optimizations for a given architecture. 13290e242208SHassan Naveed 1330d60d7de3SSven Schnelleconfig ARCH_HAS_VDSO_DATA 1331d60d7de3SSven Schnelle bool 1332d60d7de3SSven Schnelle 1333115284d8SJosh Poimboeufconfig HAVE_STATIC_CALL 1334115284d8SJosh Poimboeuf bool 1335115284d8SJosh Poimboeuf 13369183c3f9SJosh Poimboeufconfig HAVE_STATIC_CALL_INLINE 13379183c3f9SJosh Poimboeuf bool 13389183c3f9SJosh Poimboeuf depends on HAVE_STATIC_CALL 133903f16cd0SJosh Poimboeuf select OBJTOOL 13409183c3f9SJosh Poimboeuf 13416ef869e0SMichal Hockoconfig HAVE_PREEMPT_DYNAMIC 13426ef869e0SMichal Hocko bool 134399cf983cSMark Rutland 134499cf983cSMark Rutlandconfig HAVE_PREEMPT_DYNAMIC_CALL 134599cf983cSMark Rutland bool 13466ef869e0SMichal Hocko depends on HAVE_STATIC_CALL 134799cf983cSMark Rutland select HAVE_PREEMPT_DYNAMIC 13486ef869e0SMichal Hocko help 134999cf983cSMark Rutland An architecture should select this if it can handle the preemption 135099cf983cSMark Rutland model being selected at boot time using static calls. 135199cf983cSMark Rutland 135299cf983cSMark Rutland Where an architecture selects HAVE_STATIC_CALL_INLINE, any call to a 135399cf983cSMark Rutland preemption function will be patched directly. 135499cf983cSMark Rutland 135599cf983cSMark Rutland Where an architecture does not select HAVE_STATIC_CALL_INLINE, any 135699cf983cSMark Rutland call to a preemption function will go through a trampoline, and the 135799cf983cSMark Rutland trampoline will be patched. 135899cf983cSMark Rutland 135999cf983cSMark Rutland It is strongly advised to support inline static call to avoid any 136099cf983cSMark Rutland overhead. 136199cf983cSMark Rutland 136299cf983cSMark Rutlandconfig HAVE_PREEMPT_DYNAMIC_KEY 136399cf983cSMark Rutland bool 1364a0a12c3eSNick Desaulniers depends on HAVE_ARCH_JUMP_LABEL 136599cf983cSMark Rutland select HAVE_PREEMPT_DYNAMIC 136699cf983cSMark Rutland help 136799cf983cSMark Rutland An architecture should select this if it can handle the preemption 136899cf983cSMark Rutland model being selected at boot time using static keys. 136999cf983cSMark Rutland 137099cf983cSMark Rutland Each preemption function will be given an early return based on a 137199cf983cSMark Rutland static key. This should have slightly lower overhead than non-inline 137299cf983cSMark Rutland static calls, as this effectively inlines each trampoline into the 137399cf983cSMark Rutland start of its callee. This may avoid redundant work, and may 137499cf983cSMark Rutland integrate better with CFI schemes. 137599cf983cSMark Rutland 137699cf983cSMark Rutland This will have greater overhead than using inline static calls as 137799cf983cSMark Rutland the call to the preemption function cannot be entirely elided. 13786ef869e0SMichal Hocko 137959612b24SNathan Chancellorconfig ARCH_WANT_LD_ORPHAN_WARN 138059612b24SNathan Chancellor bool 138159612b24SNathan Chancellor help 138259612b24SNathan Chancellor An arch should select this symbol once all linker sections are explicitly 138359612b24SNathan Chancellor included, size-asserted, or discarded in the linker scripts. This is 138459612b24SNathan Chancellor important because we never want expected sections to be placed heuristically 138559612b24SNathan Chancellor by the linker, since the locations of such sections can change between linker 138659612b24SNathan Chancellor versions. 138759612b24SNathan Chancellor 13884f5b0c17SMike Rapoportconfig HAVE_ARCH_PFN_VALID 13894f5b0c17SMike Rapoport bool 13904f5b0c17SMike Rapoport 13915d6ad668SMike Rapoportconfig ARCH_SUPPORTS_DEBUG_PAGEALLOC 13925d6ad668SMike Rapoport bool 13935d6ad668SMike Rapoport 1394df4e817bSPasha Tatashinconfig ARCH_SUPPORTS_PAGE_TABLE_CHECK 1395df4e817bSPasha Tatashin bool 1396df4e817bSPasha Tatashin 13972ca408d9SBrian Gerstconfig ARCH_SPLIT_ARG64 13982ca408d9SBrian Gerst bool 13992ca408d9SBrian Gerst help 14002ca408d9SBrian Gerst If a 32-bit architecture requires 64-bit arguments to be split into 14012ca408d9SBrian Gerst pairs of 32-bit arguments, select this option. 14022ca408d9SBrian Gerst 14037facdc42SAl Viroconfig ARCH_HAS_ELFCORE_COMPAT 14047facdc42SAl Viro bool 14057facdc42SAl Viro 140658e106e7SBalbir Singhconfig ARCH_HAS_PARANOID_L1D_FLUSH 140758e106e7SBalbir Singh bool 140858e106e7SBalbir Singh 1409d593d64fSPrasad Sodagudiconfig ARCH_HAVE_TRACE_MMIO_ACCESS 1410d593d64fSPrasad Sodagudi bool 1411d593d64fSPrasad Sodagudi 14121bdda24cSThomas Gleixnerconfig DYNAMIC_SIGFRAME 14131bdda24cSThomas Gleixner bool 14141bdda24cSThomas Gleixner 141550468e43SJarkko Sakkinen# Select, if arch has a named attribute group bound to NUMA device nodes. 141650468e43SJarkko Sakkinenconfig HAVE_ARCH_NODE_DEV_GROUP 141750468e43SJarkko Sakkinen bool 141850468e43SJarkko Sakkinen 1419eed9a328SYu Zhaoconfig ARCH_HAS_NONLEAF_PMD_YOUNG 1420eed9a328SYu Zhao bool 1421eed9a328SYu Zhao help 1422eed9a328SYu Zhao Architectures that select this option are capable of setting the 1423eed9a328SYu Zhao accessed bit in non-leaf PMD entries when using them as part of linear 1424eed9a328SYu Zhao address translations. Page table walkers that clear the accessed bit 1425eed9a328SYu Zhao may use this capability to reduce their search space. 1426eed9a328SYu Zhao 14272521f2c2SPeter Oberparleitersource "kernel/gcov/Kconfig" 142845332b1bSMasahiro Yamada 142945332b1bSMasahiro Yamadasource "scripts/gcc-plugins/Kconfig" 1430fa1b5d09SLinus Torvalds 1431*d49a0626SPeter Zijlstraconfig FUNCTION_ALIGNMENT_4B 1432*d49a0626SPeter Zijlstra bool 1433*d49a0626SPeter Zijlstra 1434*d49a0626SPeter Zijlstraconfig FUNCTION_ALIGNMENT_8B 1435*d49a0626SPeter Zijlstra bool 1436*d49a0626SPeter Zijlstra 1437*d49a0626SPeter Zijlstraconfig FUNCTION_ALIGNMENT_16B 1438*d49a0626SPeter Zijlstra bool 1439*d49a0626SPeter Zijlstra 1440*d49a0626SPeter Zijlstraconfig FUNCTION_ALIGNMENT_32B 1441*d49a0626SPeter Zijlstra bool 1442*d49a0626SPeter Zijlstra 1443*d49a0626SPeter Zijlstraconfig FUNCTION_ALIGNMENT_64B 1444*d49a0626SPeter Zijlstra bool 1445*d49a0626SPeter Zijlstra 1446*d49a0626SPeter Zijlstraconfig FUNCTION_ALIGNMENT 1447*d49a0626SPeter Zijlstra int 1448*d49a0626SPeter Zijlstra default 64 if FUNCTION_ALIGNMENT_64B 1449*d49a0626SPeter Zijlstra default 32 if FUNCTION_ALIGNMENT_32B 1450*d49a0626SPeter Zijlstra default 16 if FUNCTION_ALIGNMENT_16B 1451*d49a0626SPeter Zijlstra default 8 if FUNCTION_ALIGNMENT_8B 1452*d49a0626SPeter Zijlstra default 4 if FUNCTION_ALIGNMENT_4B 1453*d49a0626SPeter Zijlstra default 0 1454*d49a0626SPeter Zijlstra 145522471e13SRandy Dunlapendmenu 1456