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_FUNCTION_ARG_ACCESS_API 359 bool 360 help 361 This symbol should be selected by an architecture if it supports 362 the API needed to access function arguments from pt_regs, 363 declared in asm/ptrace.h 364 365config HAVE_HW_BREAKPOINT 366 bool 367 depends on PERF_EVENTS 368 369config HAVE_MIXED_BREAKPOINTS_REGS 370 bool 371 depends on HAVE_HW_BREAKPOINT 372 help 373 Depending on the arch implementation of hardware breakpoints, 374 some of them have separate registers for data and instruction 375 breakpoints addresses, others have mixed registers to store 376 them but define the access type in a control register. 377 Select this option if your arch implements breakpoints under the 378 latter fashion. 379 380config HAVE_USER_RETURN_NOTIFIER 381 bool 382 383config HAVE_PERF_EVENTS_NMI 384 bool 385 help 386 System hardware can generate an NMI using the perf event 387 subsystem. Also has support for calculating CPU cycle events 388 to determine how many clock cycles in a given period. 389 390config HAVE_HARDLOCKUP_DETECTOR_PERF 391 bool 392 depends on HAVE_PERF_EVENTS_NMI 393 help 394 The arch chooses to use the generic perf-NMI-based hardlockup 395 detector. Must define HAVE_PERF_EVENTS_NMI. 396 397config HAVE_NMI_WATCHDOG 398 depends on HAVE_NMI 399 bool 400 help 401 The arch provides a low level NMI watchdog. It provides 402 asm/nmi.h, and defines its own arch_touch_nmi_watchdog(). 403 404config HAVE_HARDLOCKUP_DETECTOR_ARCH 405 bool 406 select HAVE_NMI_WATCHDOG 407 help 408 The arch chooses to provide its own hardlockup detector, which is 409 a superset of the HAVE_NMI_WATCHDOG. It also conforms to config 410 interfaces and parameters provided by hardlockup detector subsystem. 411 412config HAVE_PERF_REGS 413 bool 414 help 415 Support selective register dumps for perf events. This includes 416 bit-mapping of each registers and a unique architecture id. 417 418config HAVE_PERF_USER_STACK_DUMP 419 bool 420 help 421 Support user stack dumps for perf event samples. This needs 422 access to the user stack pointer which is not unified across 423 architectures. 424 425config HAVE_ARCH_JUMP_LABEL 426 bool 427 428config HAVE_ARCH_JUMP_LABEL_RELATIVE 429 bool 430 431config MMU_GATHER_TABLE_FREE 432 bool 433 434config MMU_GATHER_RCU_TABLE_FREE 435 bool 436 select MMU_GATHER_TABLE_FREE 437 438config MMU_GATHER_PAGE_SIZE 439 bool 440 441config MMU_GATHER_NO_RANGE 442 bool 443 select MMU_GATHER_MERGE_VMAS 444 445config MMU_GATHER_NO_FLUSH_CACHE 446 bool 447 448config MMU_GATHER_MERGE_VMAS 449 bool 450 451config MMU_GATHER_NO_GATHER 452 bool 453 depends on MMU_GATHER_TABLE_FREE 454 455config ARCH_WANT_IRQS_OFF_ACTIVATE_MM 456 bool 457 help 458 Temporary select until all architectures can be converted to have 459 irqs disabled over activate_mm. Architectures that do IPI based TLB 460 shootdowns should enable this. 461 462config ARCH_HAVE_NMI_SAFE_CMPXCHG 463 bool 464 465config HAVE_ALIGNED_STRUCT_PAGE 466 bool 467 help 468 This makes sure that struct pages are double word aligned and that 469 e.g. the SLUB allocator can perform double word atomic operations 470 on a struct page for better performance. However selecting this 471 might increase the size of a struct page by a word. 472 473config HAVE_CMPXCHG_LOCAL 474 bool 475 476config HAVE_CMPXCHG_DOUBLE 477 bool 478 479config ARCH_WEAK_RELEASE_ACQUIRE 480 bool 481 482config ARCH_WANT_IPC_PARSE_VERSION 483 bool 484 485config ARCH_WANT_COMPAT_IPC_PARSE_VERSION 486 bool 487 488config ARCH_WANT_OLD_COMPAT_IPC 489 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION 490 bool 491 492config HAVE_ARCH_SECCOMP 493 bool 494 help 495 An arch should select this symbol to support seccomp mode 1 (the fixed 496 syscall policy), and must provide an overrides for __NR_seccomp_sigreturn, 497 and compat syscalls if the asm-generic/seccomp.h defaults need adjustment: 498 - __NR_seccomp_read_32 499 - __NR_seccomp_write_32 500 - __NR_seccomp_exit_32 501 - __NR_seccomp_sigreturn_32 502 503config HAVE_ARCH_SECCOMP_FILTER 504 bool 505 select HAVE_ARCH_SECCOMP 506 help 507 An arch should select this symbol if it provides all of these things: 508 - all the requirements for HAVE_ARCH_SECCOMP 509 - syscall_get_arch() 510 - syscall_get_arguments() 511 - syscall_rollback() 512 - syscall_set_return_value() 513 - SIGSYS siginfo_t support 514 - secure_computing is called from a ptrace_event()-safe context 515 - secure_computing return value is checked and a return value of -1 516 results in the system call being skipped immediately. 517 - seccomp syscall wired up 518 - if !HAVE_SPARSE_SYSCALL_NR, have SECCOMP_ARCH_NATIVE, 519 SECCOMP_ARCH_NATIVE_NR, SECCOMP_ARCH_NATIVE_NAME defined. If 520 COMPAT is supported, have the SECCOMP_ARCH_COMPAT* defines too. 521 522config SECCOMP 523 prompt "Enable seccomp to safely execute untrusted bytecode" 524 def_bool y 525 depends on HAVE_ARCH_SECCOMP 526 help 527 This kernel feature is useful for number crunching applications 528 that may need to handle untrusted bytecode during their 529 execution. By using pipes or other transports made available 530 to the process as file descriptors supporting the read/write 531 syscalls, it's possible to isolate those applications in their 532 own address space using seccomp. Once seccomp is enabled via 533 prctl(PR_SET_SECCOMP) or the seccomp() syscall, it cannot be 534 disabled and the task is only allowed to execute a few safe 535 syscalls defined by each seccomp mode. 536 537 If unsure, say Y. 538 539config SECCOMP_FILTER 540 def_bool y 541 depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET 542 help 543 Enable tasks to build secure computing environments defined 544 in terms of Berkeley Packet Filter programs which implement 545 task-defined system call filtering polices. 546 547 See Documentation/userspace-api/seccomp_filter.rst for details. 548 549config SECCOMP_CACHE_DEBUG 550 bool "Show seccomp filter cache status in /proc/pid/seccomp_cache" 551 depends on SECCOMP_FILTER && !HAVE_SPARSE_SYSCALL_NR 552 depends on PROC_FS 553 help 554 This enables the /proc/pid/seccomp_cache interface to monitor 555 seccomp cache data. The file format is subject to change. Reading 556 the file requires CAP_SYS_ADMIN. 557 558 This option is for debugging only. Enabling presents the risk that 559 an adversary may be able to infer the seccomp filter logic. 560 561 If unsure, say N. 562 563config HAVE_ARCH_STACKLEAK 564 bool 565 help 566 An architecture should select this if it has the code which 567 fills the used part of the kernel stack with the STACKLEAK_POISON 568 value before returning from system calls. 569 570config HAVE_STACKPROTECTOR 571 bool 572 help 573 An arch should select this symbol if: 574 - it has implemented a stack canary (e.g. __stack_chk_guard) 575 576config STACKPROTECTOR 577 bool "Stack Protector buffer overflow detection" 578 depends on HAVE_STACKPROTECTOR 579 depends on $(cc-option,-fstack-protector) 580 default y 581 help 582 This option turns on the "stack-protector" GCC feature. This 583 feature puts, at the beginning of functions, a canary value on 584 the stack just before the return address, and validates 585 the value just before actually returning. Stack based buffer 586 overflows (that need to overwrite this return address) now also 587 overwrite the canary, which gets detected and the attack is then 588 neutralized via a kernel panic. 589 590 Functions will have the stack-protector canary logic added if they 591 have an 8-byte or larger character array on the stack. 592 593 This feature requires gcc version 4.2 or above, or a distribution 594 gcc with the feature backported ("-fstack-protector"). 595 596 On an x86 "defconfig" build, this feature adds canary checks to 597 about 3% of all kernel functions, which increases kernel code size 598 by about 0.3%. 599 600config STACKPROTECTOR_STRONG 601 bool "Strong Stack Protector" 602 depends on STACKPROTECTOR 603 depends on $(cc-option,-fstack-protector-strong) 604 default y 605 help 606 Functions will have the stack-protector canary logic added in any 607 of the following conditions: 608 609 - local variable's address used as part of the right hand side of an 610 assignment or function argument 611 - local variable is an array (or union containing an array), 612 regardless of array type or length 613 - uses register local variables 614 615 This feature requires gcc version 4.9 or above, or a distribution 616 gcc with the feature backported ("-fstack-protector-strong"). 617 618 On an x86 "defconfig" build, this feature adds canary checks to 619 about 20% of all kernel functions, which increases the kernel code 620 size by about 2%. 621 622config ARCH_SUPPORTS_SHADOW_CALL_STACK 623 bool 624 help 625 An architecture should select this if it supports the compiler's 626 Shadow Call Stack and implements runtime support for shadow stack 627 switching. 628 629config SHADOW_CALL_STACK 630 bool "Shadow Call Stack" 631 depends on ARCH_SUPPORTS_SHADOW_CALL_STACK 632 depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER 633 help 634 This option enables the compiler's Shadow Call Stack, which 635 uses a shadow stack to protect function return addresses from 636 being overwritten by an attacker. More information can be found 637 in the compiler's documentation: 638 639 - Clang: https://clang.llvm.org/docs/ShadowCallStack.html 640 - GCC: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options 641 642 Note that security guarantees in the kernel differ from the 643 ones documented for user space. The kernel must store addresses 644 of shadow stacks in memory, which means an attacker capable of 645 reading and writing arbitrary memory may be able to locate them 646 and hijack control flow by modifying the stacks. 647 648config LTO 649 bool 650 help 651 Selected if the kernel will be built using the compiler's LTO feature. 652 653config LTO_CLANG 654 bool 655 select LTO 656 help 657 Selected if the kernel will be built using Clang's LTO feature. 658 659config ARCH_SUPPORTS_LTO_CLANG 660 bool 661 help 662 An architecture should select this option if it supports: 663 - compiling with Clang, 664 - compiling inline assembly with Clang's integrated assembler, 665 - and linking with LLD. 666 667config ARCH_SUPPORTS_LTO_CLANG_THIN 668 bool 669 help 670 An architecture should select this option if it can support Clang's 671 ThinLTO mode. 672 673config HAS_LTO_CLANG 674 def_bool y 675 depends on CC_IS_CLANG && LD_IS_LLD && AS_IS_LLVM 676 depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm) 677 depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm) 678 depends on ARCH_SUPPORTS_LTO_CLANG 679 depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT 680 depends on !KASAN || KASAN_HW_TAGS 681 depends on !GCOV_KERNEL 682 help 683 The compiler and Kconfig options support building with Clang's 684 LTO. 685 686choice 687 prompt "Link Time Optimization (LTO)" 688 default LTO_NONE 689 help 690 This option enables Link Time Optimization (LTO), which allows the 691 compiler to optimize binaries globally. 692 693 If unsure, select LTO_NONE. Note that LTO is very resource-intensive 694 so it's disabled by default. 695 696config LTO_NONE 697 bool "None" 698 help 699 Build the kernel normally, without Link Time Optimization (LTO). 700 701config LTO_CLANG_FULL 702 bool "Clang Full LTO (EXPERIMENTAL)" 703 depends on HAS_LTO_CLANG 704 depends on !COMPILE_TEST 705 select LTO_CLANG 706 help 707 This option enables Clang's full Link Time Optimization (LTO), which 708 allows the compiler to optimize the kernel globally. If you enable 709 this option, the compiler generates LLVM bitcode instead of ELF 710 object files, and the actual compilation from bitcode happens at 711 the LTO link step, which may take several minutes depending on the 712 kernel configuration. More information can be found from LLVM's 713 documentation: 714 715 https://llvm.org/docs/LinkTimeOptimization.html 716 717 During link time, this option can use a large amount of RAM, and 718 may take much longer than the ThinLTO option. 719 720config LTO_CLANG_THIN 721 bool "Clang ThinLTO (EXPERIMENTAL)" 722 depends on HAS_LTO_CLANG && ARCH_SUPPORTS_LTO_CLANG_THIN 723 select LTO_CLANG 724 help 725 This option enables Clang's ThinLTO, which allows for parallel 726 optimization and faster incremental compiles compared to the 727 CONFIG_LTO_CLANG_FULL option. More information can be found 728 from Clang's documentation: 729 730 https://clang.llvm.org/docs/ThinLTO.html 731 732 If unsure, say Y. 733endchoice 734 735config ARCH_SUPPORTS_CFI_CLANG 736 bool 737 help 738 An architecture should select this option if it can support Clang's 739 Control-Flow Integrity (CFI) checking. 740 741config CFI_CLANG 742 bool "Use Clang's Control Flow Integrity (CFI)" 743 depends on LTO_CLANG && ARCH_SUPPORTS_CFI_CLANG 744 depends on CLANG_VERSION >= 140000 745 select KALLSYMS 746 help 747 This option enables Clang’s forward-edge Control Flow Integrity 748 (CFI) checking, where the compiler injects a runtime check to each 749 indirect function call to ensure the target is a valid function with 750 the correct static type. This restricts possible call targets and 751 makes it more difficult for an attacker to exploit bugs that allow 752 the modification of stored function pointers. More information can be 753 found from Clang's documentation: 754 755 https://clang.llvm.org/docs/ControlFlowIntegrity.html 756 757config CFI_CLANG_SHADOW 758 bool "Use CFI shadow to speed up cross-module checks" 759 default y 760 depends on CFI_CLANG && MODULES 761 help 762 If you select this option, the kernel builds a fast look-up table of 763 CFI check functions in loaded modules to reduce performance overhead. 764 765 If unsure, say Y. 766 767config CFI_PERMISSIVE 768 bool "Use CFI in permissive mode" 769 depends on CFI_CLANG 770 help 771 When selected, Control Flow Integrity (CFI) violations result in a 772 warning instead of a kernel panic. This option should only be used 773 for finding indirect call type mismatches during development. 774 775 If unsure, say N. 776 777config HAVE_ARCH_WITHIN_STACK_FRAMES 778 bool 779 help 780 An architecture should select this if it can walk the kernel stack 781 frames to determine if an object is part of either the arguments 782 or local variables (i.e. that it excludes saved return addresses, 783 and similar) by implementing an inline arch_within_stack_frames(), 784 which is used by CONFIG_HARDENED_USERCOPY. 785 786config HAVE_CONTEXT_TRACKING_USER 787 bool 788 help 789 Provide kernel/user boundaries probes necessary for subsystems 790 that need it, such as userspace RCU extended quiescent state. 791 Syscalls need to be wrapped inside user_exit()-user_enter(), either 792 optimized behind static key or through the slow path using TIF_NOHZ 793 flag. Exceptions handlers must be wrapped as well. Irqs are already 794 protected inside ct_irq_enter/ct_irq_exit() but preemption or signal 795 handling on irq exit still need to be protected. 796 797config HAVE_CONTEXT_TRACKING_USER_OFFSTACK 798 bool 799 help 800 Architecture neither relies on exception_enter()/exception_exit() 801 nor on schedule_user(). Also preempt_schedule_notrace() and 802 preempt_schedule_irq() can't be called in a preemptible section 803 while context tracking is CONTEXT_USER. This feature reflects a sane 804 entry implementation where the following requirements are met on 805 critical entry code, ie: before user_exit() or after user_enter(): 806 807 - Critical entry code isn't preemptible (or better yet: 808 not interruptible). 809 - No use of RCU read side critical sections, unless ct_nmi_enter() 810 got called. 811 - No use of instrumentation, unless instrumentation_begin() got 812 called. 813 814config HAVE_TIF_NOHZ 815 bool 816 help 817 Arch relies on TIF_NOHZ and syscall slow path to implement context 818 tracking calls to user_enter()/user_exit(). 819 820config HAVE_VIRT_CPU_ACCOUNTING 821 bool 822 823config HAVE_VIRT_CPU_ACCOUNTING_IDLE 824 bool 825 help 826 Architecture has its own way to account idle CPU time and therefore 827 doesn't implement vtime_account_idle(). 828 829config ARCH_HAS_SCALED_CPUTIME 830 bool 831 832config HAVE_VIRT_CPU_ACCOUNTING_GEN 833 bool 834 default y if 64BIT 835 help 836 With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit. 837 Before enabling this option, arch code must be audited 838 to ensure there are no races in concurrent read/write of 839 cputime_t. For example, reading/writing 64-bit cputime_t on 840 some 32-bit arches may require multiple accesses, so proper 841 locking is needed to protect against concurrent accesses. 842 843config HAVE_IRQ_TIME_ACCOUNTING 844 bool 845 help 846 Archs need to ensure they use a high enough resolution clock to 847 support irq time accounting and then call enable_sched_clock_irqtime(). 848 849config HAVE_MOVE_PUD 850 bool 851 help 852 Architectures that select this are able to move page tables at the 853 PUD level. If there are only 3 page table levels, the move effectively 854 happens at the PGD level. 855 856config HAVE_MOVE_PMD 857 bool 858 help 859 Archs that select this are able to move page tables at the PMD level. 860 861config HAVE_ARCH_TRANSPARENT_HUGEPAGE 862 bool 863 864config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 865 bool 866 867config HAVE_ARCH_HUGE_VMAP 868 bool 869 870# 871# Archs that select this would be capable of PMD-sized vmaps (i.e., 872# arch_vmap_pmd_supported() returns true). The VM_ALLOW_HUGE_VMAP flag 873# must be used to enable allocations to use hugepages. 874# 875config HAVE_ARCH_HUGE_VMALLOC 876 depends on HAVE_ARCH_HUGE_VMAP 877 bool 878 879config ARCH_WANT_HUGE_PMD_SHARE 880 bool 881 882config HAVE_ARCH_SOFT_DIRTY 883 bool 884 885config HAVE_MOD_ARCH_SPECIFIC 886 bool 887 help 888 The arch uses struct mod_arch_specific to store data. Many arches 889 just need a simple module loader without arch specific data - those 890 should not enable this. 891 892config MODULES_USE_ELF_RELA 893 bool 894 help 895 Modules only use ELF RELA relocations. Modules with ELF REL 896 relocations will give an error. 897 898config MODULES_USE_ELF_REL 899 bool 900 help 901 Modules only use ELF REL relocations. Modules with ELF RELA 902 relocations will give an error. 903 904config ARCH_WANTS_MODULES_DATA_IN_VMALLOC 905 bool 906 help 907 For architectures like powerpc/32 which have constraints on module 908 allocation and need to allocate module data outside of module area. 909 910config HAVE_IRQ_EXIT_ON_IRQ_STACK 911 bool 912 help 913 Architecture doesn't only execute the irq handler on the irq stack 914 but also irq_exit(). This way we can process softirqs on this irq 915 stack instead of switching to a new one when we call __do_softirq() 916 in the end of an hardirq. 917 This spares a stack switch and improves cache usage on softirq 918 processing. 919 920config HAVE_SOFTIRQ_ON_OWN_STACK 921 bool 922 help 923 Architecture provides a function to run __do_softirq() on a 924 separate stack. 925 926config SOFTIRQ_ON_OWN_STACK 927 def_bool HAVE_SOFTIRQ_ON_OWN_STACK && !PREEMPT_RT 928 929config ALTERNATE_USER_ADDRESS_SPACE 930 bool 931 help 932 Architectures set this when the CPU uses separate address 933 spaces for kernel and user space pointers. In this case, the 934 access_ok() check on a __user pointer is skipped. 935 936config PGTABLE_LEVELS 937 int 938 default 2 939 940config ARCH_HAS_ELF_RANDOMIZE 941 bool 942 help 943 An architecture supports choosing randomized locations for 944 stack, mmap, brk, and ET_DYN. Defined functions: 945 - arch_mmap_rnd() 946 - arch_randomize_brk() 947 948config HAVE_ARCH_MMAP_RND_BITS 949 bool 950 help 951 An arch should select this symbol if it supports setting a variable 952 number of bits for use in establishing the base address for mmap 953 allocations, has MMU enabled and provides values for both: 954 - ARCH_MMAP_RND_BITS_MIN 955 - ARCH_MMAP_RND_BITS_MAX 956 957config HAVE_EXIT_THREAD 958 bool 959 help 960 An architecture implements exit_thread. 961 962config ARCH_MMAP_RND_BITS_MIN 963 int 964 965config ARCH_MMAP_RND_BITS_MAX 966 int 967 968config ARCH_MMAP_RND_BITS_DEFAULT 969 int 970 971config ARCH_MMAP_RND_BITS 972 int "Number of bits to use for ASLR of mmap base address" if EXPERT 973 range ARCH_MMAP_RND_BITS_MIN ARCH_MMAP_RND_BITS_MAX 974 default ARCH_MMAP_RND_BITS_DEFAULT if ARCH_MMAP_RND_BITS_DEFAULT 975 default ARCH_MMAP_RND_BITS_MIN 976 depends on HAVE_ARCH_MMAP_RND_BITS 977 help 978 This value can be used to select the number of bits to use to 979 determine the random offset to the base address of vma regions 980 resulting from mmap allocations. This value will be bounded 981 by the architecture's minimum and maximum supported values. 982 983 This value can be changed after boot using the 984 /proc/sys/vm/mmap_rnd_bits tunable 985 986config HAVE_ARCH_MMAP_RND_COMPAT_BITS 987 bool 988 help 989 An arch should select this symbol if it supports running applications 990 in compatibility mode, supports setting a variable number of bits for 991 use in establishing the base address for mmap allocations, has MMU 992 enabled and provides values for both: 993 - ARCH_MMAP_RND_COMPAT_BITS_MIN 994 - ARCH_MMAP_RND_COMPAT_BITS_MAX 995 996config ARCH_MMAP_RND_COMPAT_BITS_MIN 997 int 998 999config ARCH_MMAP_RND_COMPAT_BITS_MAX 1000 int 1001 1002config ARCH_MMAP_RND_COMPAT_BITS_DEFAULT 1003 int 1004 1005config ARCH_MMAP_RND_COMPAT_BITS 1006 int "Number of bits to use for ASLR of mmap base address for compatible applications" if EXPERT 1007 range ARCH_MMAP_RND_COMPAT_BITS_MIN ARCH_MMAP_RND_COMPAT_BITS_MAX 1008 default ARCH_MMAP_RND_COMPAT_BITS_DEFAULT if ARCH_MMAP_RND_COMPAT_BITS_DEFAULT 1009 default ARCH_MMAP_RND_COMPAT_BITS_MIN 1010 depends on HAVE_ARCH_MMAP_RND_COMPAT_BITS 1011 help 1012 This value can be used to select the number of bits to use to 1013 determine the random offset to the base address of vma regions 1014 resulting from mmap allocations for compatible applications This 1015 value will be bounded by the architecture's minimum and maximum 1016 supported values. 1017 1018 This value can be changed after boot using the 1019 /proc/sys/vm/mmap_rnd_compat_bits tunable 1020 1021config HAVE_ARCH_COMPAT_MMAP_BASES 1022 bool 1023 help 1024 This allows 64bit applications to invoke 32-bit mmap() syscall 1025 and vice-versa 32-bit applications to call 64-bit mmap(). 1026 Required for applications doing different bitness syscalls. 1027 1028config PAGE_SIZE_LESS_THAN_64KB 1029 def_bool y 1030 depends on !ARM64_64K_PAGES 1031 depends on !IA64_PAGE_SIZE_64KB 1032 depends on !PAGE_SIZE_64KB 1033 depends on !PARISC_PAGE_SIZE_64KB 1034 depends on PAGE_SIZE_LESS_THAN_256KB 1035 1036config PAGE_SIZE_LESS_THAN_256KB 1037 def_bool y 1038 depends on !PAGE_SIZE_256KB 1039 1040# This allows to use a set of generic functions to determine mmap base 1041# address by giving priority to top-down scheme only if the process 1042# is not in legacy mode (compat task, unlimited stack size or 1043# sysctl_legacy_va_layout). 1044# Architecture that selects this option can provide its own version of: 1045# - STACK_RND_MASK 1046config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 1047 bool 1048 depends on MMU 1049 select ARCH_HAS_ELF_RANDOMIZE 1050 1051config HAVE_OBJTOOL 1052 bool 1053 1054config HAVE_JUMP_LABEL_HACK 1055 bool 1056 1057config HAVE_NOINSTR_HACK 1058 bool 1059 1060config HAVE_NOINSTR_VALIDATION 1061 bool 1062 1063config HAVE_UACCESS_VALIDATION 1064 bool 1065 select OBJTOOL 1066 1067config HAVE_STACK_VALIDATION 1068 bool 1069 help 1070 Architecture supports objtool compile-time frame pointer rule 1071 validation. 1072 1073config HAVE_RELIABLE_STACKTRACE 1074 bool 1075 help 1076 Architecture has either save_stack_trace_tsk_reliable() or 1077 arch_stack_walk_reliable() function which only returns a stack trace 1078 if it can guarantee the trace is reliable. 1079 1080config HAVE_ARCH_HASH 1081 bool 1082 default n 1083 help 1084 If this is set, the architecture provides an <asm/hash.h> 1085 file which provides platform-specific implementations of some 1086 functions in <linux/hash.h> or fs/namei.c. 1087 1088config HAVE_ARCH_NVRAM_OPS 1089 bool 1090 1091config ISA_BUS_API 1092 def_bool ISA 1093 1094# 1095# ABI hall of shame 1096# 1097config CLONE_BACKWARDS 1098 bool 1099 help 1100 Architecture has tls passed as the 4th argument of clone(2), 1101 not the 5th one. 1102 1103config CLONE_BACKWARDS2 1104 bool 1105 help 1106 Architecture has the first two arguments of clone(2) swapped. 1107 1108config CLONE_BACKWARDS3 1109 bool 1110 help 1111 Architecture has tls passed as the 3rd argument of clone(2), 1112 not the 5th one. 1113 1114config ODD_RT_SIGACTION 1115 bool 1116 help 1117 Architecture has unusual rt_sigaction(2) arguments 1118 1119config OLD_SIGSUSPEND 1120 bool 1121 help 1122 Architecture has old sigsuspend(2) syscall, of one-argument variety 1123 1124config OLD_SIGSUSPEND3 1125 bool 1126 help 1127 Even weirder antique ABI - three-argument sigsuspend(2) 1128 1129config OLD_SIGACTION 1130 bool 1131 help 1132 Architecture has old sigaction(2) syscall. Nope, not the same 1133 as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2), 1134 but fairly different variant of sigaction(2), thanks to OSF/1 1135 compatibility... 1136 1137config COMPAT_OLD_SIGACTION 1138 bool 1139 1140config COMPAT_32BIT_TIME 1141 bool "Provide system calls for 32-bit time_t" 1142 default !64BIT || COMPAT 1143 help 1144 This enables 32 bit time_t support in addition to 64 bit time_t support. 1145 This is relevant on all 32-bit architectures, and 64-bit architectures 1146 as part of compat syscall handling. 1147 1148config ARCH_NO_PREEMPT 1149 bool 1150 1151config ARCH_EPHEMERAL_INODES 1152 def_bool n 1153 help 1154 An arch should select this symbol if it doesn't keep track of inode 1155 instances on its own, but instead relies on something else (e.g. the 1156 host kernel for an UML kernel). 1157 1158config ARCH_SUPPORTS_RT 1159 bool 1160 1161config CPU_NO_EFFICIENT_FFS 1162 def_bool n 1163 1164config HAVE_ARCH_VMAP_STACK 1165 def_bool n 1166 help 1167 An arch should select this symbol if it can support kernel stacks 1168 in vmalloc space. This means: 1169 1170 - vmalloc space must be large enough to hold many kernel stacks. 1171 This may rule out many 32-bit architectures. 1172 1173 - Stacks in vmalloc space need to work reliably. For example, if 1174 vmap page tables are created on demand, either this mechanism 1175 needs to work while the stack points to a virtual address with 1176 unpopulated page tables or arch code (switch_to() and switch_mm(), 1177 most likely) needs to ensure that the stack's page table entries 1178 are populated before running on a possibly unpopulated stack. 1179 1180 - If the stack overflows into a guard page, something reasonable 1181 should happen. The definition of "reasonable" is flexible, but 1182 instantly rebooting without logging anything would be unfriendly. 1183 1184config VMAP_STACK 1185 default y 1186 bool "Use a virtually-mapped stack" 1187 depends on HAVE_ARCH_VMAP_STACK 1188 depends on !KASAN || KASAN_HW_TAGS || KASAN_VMALLOC 1189 help 1190 Enable this if you want the use virtually-mapped kernel stacks 1191 with guard pages. This causes kernel stack overflows to be 1192 caught immediately rather than causing difficult-to-diagnose 1193 corruption. 1194 1195 To use this with software KASAN modes, the architecture must support 1196 backing virtual mappings with real shadow memory, and KASAN_VMALLOC 1197 must be enabled. 1198 1199config HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 1200 def_bool n 1201 help 1202 An arch should select this symbol if it can support kernel stack 1203 offset randomization with calls to add_random_kstack_offset() 1204 during syscall entry and choose_random_kstack_offset() during 1205 syscall exit. Careful removal of -fstack-protector-strong and 1206 -fstack-protector should also be applied to the entry code and 1207 closely examined, as the artificial stack bump looks like an array 1208 to the compiler, so it will attempt to add canary checks regardless 1209 of the static branch state. 1210 1211config RANDOMIZE_KSTACK_OFFSET 1212 bool "Support for randomizing kernel stack offset on syscall entry" if EXPERT 1213 default y 1214 depends on HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 1215 depends on INIT_STACK_NONE || !CC_IS_CLANG || CLANG_VERSION >= 140000 1216 help 1217 The kernel stack offset can be randomized (after pt_regs) by 1218 roughly 5 bits of entropy, frustrating memory corruption 1219 attacks that depend on stack address determinism or 1220 cross-syscall address exposures. 1221 1222 The feature is controlled via the "randomize_kstack_offset=on/off" 1223 kernel boot param, and if turned off has zero overhead due to its use 1224 of static branches (see JUMP_LABEL). 1225 1226 If unsure, say Y. 1227 1228config RANDOMIZE_KSTACK_OFFSET_DEFAULT 1229 bool "Default state of kernel stack offset randomization" 1230 depends on RANDOMIZE_KSTACK_OFFSET 1231 help 1232 Kernel stack offset randomization is controlled by kernel boot param 1233 "randomize_kstack_offset=on/off", and this config chooses the default 1234 boot state. 1235 1236config ARCH_OPTIONAL_KERNEL_RWX 1237 def_bool n 1238 1239config ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 1240 def_bool n 1241 1242config ARCH_HAS_STRICT_KERNEL_RWX 1243 def_bool n 1244 1245config STRICT_KERNEL_RWX 1246 bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX 1247 depends on ARCH_HAS_STRICT_KERNEL_RWX 1248 default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 1249 help 1250 If this is set, kernel text and rodata memory will be made read-only, 1251 and non-text memory will be made non-executable. This provides 1252 protection against certain security exploits (e.g. executing the heap 1253 or modifying text) 1254 1255 These features are considered standard security practice these days. 1256 You should say Y here in almost all cases. 1257 1258config ARCH_HAS_STRICT_MODULE_RWX 1259 def_bool n 1260 1261config STRICT_MODULE_RWX 1262 bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX 1263 depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES 1264 default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 1265 help 1266 If this is set, module text and rodata memory will be made read-only, 1267 and non-text memory will be made non-executable. This provides 1268 protection against certain security exploits (e.g. writing to text) 1269 1270# select if the architecture provides an asm/dma-direct.h header 1271config ARCH_HAS_PHYS_TO_DMA 1272 bool 1273 1274config HAVE_ARCH_COMPILER_H 1275 bool 1276 help 1277 An architecture can select this if it provides an 1278 asm/compiler.h header that should be included after 1279 linux/compiler-*.h in order to override macro definitions that those 1280 headers generally provide. 1281 1282config HAVE_ARCH_PREL32_RELOCATIONS 1283 bool 1284 help 1285 May be selected by an architecture if it supports place-relative 1286 32-bit relocations, both in the toolchain and in the module loader, 1287 in which case relative references can be used in special sections 1288 for PCI fixup, initcalls etc which are only half the size on 64 bit 1289 architectures, and don't require runtime relocation on relocatable 1290 kernels. 1291 1292config ARCH_USE_MEMREMAP_PROT 1293 bool 1294 1295config LOCK_EVENT_COUNTS 1296 bool "Locking event counts collection" 1297 depends on DEBUG_FS 1298 help 1299 Enable light-weight counting of various locking related events 1300 in the system with minimal performance impact. This reduces 1301 the chance of application behavior change because of timing 1302 differences. The counts are reported via debugfs. 1303 1304# Select if the architecture has support for applying RELR relocations. 1305config ARCH_HAS_RELR 1306 bool 1307 1308config RELR 1309 bool "Use RELR relocation packing" 1310 depends on ARCH_HAS_RELR && TOOLS_SUPPORT_RELR 1311 default y 1312 help 1313 Store the kernel's dynamic relocations in the RELR relocation packing 1314 format. Requires a compatible linker (LLD supports this feature), as 1315 well as compatible NM and OBJCOPY utilities (llvm-nm and llvm-objcopy 1316 are compatible). 1317 1318config ARCH_HAS_MEM_ENCRYPT 1319 bool 1320 1321config ARCH_HAS_CC_PLATFORM 1322 bool 1323 1324config HAVE_SPARSE_SYSCALL_NR 1325 bool 1326 help 1327 An architecture should select this if its syscall numbering is sparse 1328 to save space. For example, MIPS architecture has a syscall array with 1329 entries at 4000, 5000 and 6000 locations. This option turns on syscall 1330 related optimizations for a given architecture. 1331 1332config ARCH_HAS_VDSO_DATA 1333 bool 1334 1335config HAVE_STATIC_CALL 1336 bool 1337 1338config HAVE_STATIC_CALL_INLINE 1339 bool 1340 depends on HAVE_STATIC_CALL 1341 select OBJTOOL 1342 1343config HAVE_PREEMPT_DYNAMIC 1344 bool 1345 1346config HAVE_PREEMPT_DYNAMIC_CALL 1347 bool 1348 depends on HAVE_STATIC_CALL 1349 select HAVE_PREEMPT_DYNAMIC 1350 help 1351 An architecture should select this if it can handle the preemption 1352 model being selected at boot time using static calls. 1353 1354 Where an architecture selects HAVE_STATIC_CALL_INLINE, any call to a 1355 preemption function will be patched directly. 1356 1357 Where an architecture does not select HAVE_STATIC_CALL_INLINE, any 1358 call to a preemption function will go through a trampoline, and the 1359 trampoline will be patched. 1360 1361 It is strongly advised to support inline static call to avoid any 1362 overhead. 1363 1364config HAVE_PREEMPT_DYNAMIC_KEY 1365 bool 1366 depends on HAVE_ARCH_JUMP_LABEL 1367 select HAVE_PREEMPT_DYNAMIC 1368 help 1369 An architecture should select this if it can handle the preemption 1370 model being selected at boot time using static keys. 1371 1372 Each preemption function will be given an early return based on a 1373 static key. This should have slightly lower overhead than non-inline 1374 static calls, as this effectively inlines each trampoline into the 1375 start of its callee. This may avoid redundant work, and may 1376 integrate better with CFI schemes. 1377 1378 This will have greater overhead than using inline static calls as 1379 the call to the preemption function cannot be entirely elided. 1380 1381config ARCH_WANT_LD_ORPHAN_WARN 1382 bool 1383 help 1384 An arch should select this symbol once all linker sections are explicitly 1385 included, size-asserted, or discarded in the linker scripts. This is 1386 important because we never want expected sections to be placed heuristically 1387 by the linker, since the locations of such sections can change between linker 1388 versions. 1389 1390config HAVE_ARCH_PFN_VALID 1391 bool 1392 1393config ARCH_SUPPORTS_DEBUG_PAGEALLOC 1394 bool 1395 1396config ARCH_SUPPORTS_PAGE_TABLE_CHECK 1397 bool 1398 1399config ARCH_SPLIT_ARG64 1400 bool 1401 help 1402 If a 32-bit architecture requires 64-bit arguments to be split into 1403 pairs of 32-bit arguments, select this option. 1404 1405config ARCH_HAS_ELFCORE_COMPAT 1406 bool 1407 1408config ARCH_HAS_PARANOID_L1D_FLUSH 1409 bool 1410 1411config ARCH_HAVE_TRACE_MMIO_ACCESS 1412 bool 1413 1414config DYNAMIC_SIGFRAME 1415 bool 1416 1417# Select, if arch has a named attribute group bound to NUMA device nodes. 1418config HAVE_ARCH_NODE_DEV_GROUP 1419 bool 1420 1421source "kernel/gcov/Kconfig" 1422 1423source "scripts/gcc-plugins/Kconfig" 1424 1425endmenu 1426