Kconfig (43031B)
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 depends on CC_HAS_ASM_GOTO 57 select OBJTOOL if HAVE_JUMP_LABEL_HACK 58 help 59 This option enables a transparent branch optimization that 60 makes certain almost-always-true or almost-always-false branch 61 conditions even cheaper to execute within the kernel. 62 63 Certain performance-sensitive kernel code, such as trace points, 64 scheduler functionality, networking code and KVM have such 65 branches and include support for this optimization technique. 66 67 If it is detected that the compiler has support for "asm goto", 68 the kernel will compile such branches with just a nop 69 instruction. When the condition flag is toggled to true, the 70 nop will be converted to a jump instruction to execute the 71 conditional block of instructions. 72 73 This technique lowers overhead and stress on the branch prediction 74 of the processor and generally makes the kernel faster. The update 75 of the condition is slower, but those are always very rare. 76 77 ( On 32-bit x86, the necessary options added to the compiler 78 flags may increase the size of the kernel slightly. ) 79 80config STATIC_KEYS_SELFTEST 81 bool "Static key selftest" 82 depends on JUMP_LABEL 83 help 84 Boot time self-test of the branch patching code. 85 86config STATIC_CALL_SELFTEST 87 bool "Static call selftest" 88 depends on HAVE_STATIC_CALL 89 help 90 Boot time self-test of the call patching code. 91 92config OPTPROBES 93 def_bool y 94 depends on KPROBES && HAVE_OPTPROBES 95 select TASKS_RCU if PREEMPTION 96 97config KPROBES_ON_FTRACE 98 def_bool y 99 depends on KPROBES && HAVE_KPROBES_ON_FTRACE 100 depends on DYNAMIC_FTRACE_WITH_REGS 101 help 102 If function tracer is enabled and the arch supports full 103 passing of pt_regs to function tracing, then kprobes can 104 optimize on top of function tracing. 105 106config UPROBES 107 def_bool n 108 depends on ARCH_SUPPORTS_UPROBES 109 help 110 Uprobes is the user-space counterpart to kprobes: they 111 enable instrumentation applications (such as 'perf probe') 112 to establish unintrusive probes in user-space binaries and 113 libraries, by executing handler functions when the probes 114 are hit by user-space applications. 115 116 ( These probes come in the form of single-byte breakpoints, 117 managed by the kernel and kept transparent to the probed 118 application. ) 119 120config HAVE_64BIT_ALIGNED_ACCESS 121 def_bool 64BIT && !HAVE_EFFICIENT_UNALIGNED_ACCESS 122 help 123 Some architectures require 64 bit accesses to be 64 bit 124 aligned, which also requires structs containing 64 bit values 125 to be 64 bit aligned too. This includes some 32 bit 126 architectures which can do 64 bit accesses, as well as 64 bit 127 architectures without unaligned access. 128 129 This symbol should be selected by an architecture if 64 bit 130 accesses are required to be 64 bit aligned in this way even 131 though it is not a 64 bit architecture. 132 133 See Documentation/core-api/unaligned-memory-access.rst for 134 more information on the topic of unaligned memory accesses. 135 136config HAVE_EFFICIENT_UNALIGNED_ACCESS 137 bool 138 help 139 Some architectures are unable to perform unaligned accesses 140 without the use of get_unaligned/put_unaligned. Others are 141 unable to perform such accesses efficiently (e.g. trap on 142 unaligned access and require fixing it up in the exception 143 handler.) 144 145 This symbol should be selected by an architecture if it can 146 perform unaligned accesses efficiently to allow different 147 code paths to be selected for these cases. Some network 148 drivers, for example, could opt to not fix up alignment 149 problems with received packets if doing so would not help 150 much. 151 152 See Documentation/core-api/unaligned-memory-access.rst for more 153 information on the topic of unaligned memory accesses. 154 155config ARCH_USE_BUILTIN_BSWAP 156 bool 157 help 158 Modern versions of GCC (since 4.4) have builtin functions 159 for handling byte-swapping. Using these, instead of the old 160 inline assembler that the architecture code provides in the 161 __arch_bswapXX() macros, allows the compiler to see what's 162 happening and offers more opportunity for optimisation. In 163 particular, the compiler will be able to combine the byteswap 164 with a nearby load or store and use load-and-swap or 165 store-and-swap instructions if the architecture has them. It 166 should almost *never* result in code which is worse than the 167 hand-coded assembler in <asm/swab.h>. But just in case it 168 does, the use of the builtins is optional. 169 170 Any architecture with load-and-swap or store-and-swap 171 instructions should set this. And it shouldn't hurt to set it 172 on architectures that don't have such instructions. 173 174config KRETPROBES 175 def_bool y 176 depends on KPROBES && (HAVE_KRETPROBES || HAVE_RETHOOK) 177 178config KRETPROBE_ON_RETHOOK 179 def_bool y 180 depends on HAVE_RETHOOK 181 depends on KRETPROBES 182 select RETHOOK 183 184config USER_RETURN_NOTIFIER 185 bool 186 depends on HAVE_USER_RETURN_NOTIFIER 187 help 188 Provide a kernel-internal notification when a cpu is about to 189 switch to user mode. 190 191config HAVE_IOREMAP_PROT 192 bool 193 194config HAVE_KPROBES 195 bool 196 197config HAVE_KRETPROBES 198 bool 199 200config HAVE_OPTPROBES 201 bool 202 203config HAVE_KPROBES_ON_FTRACE 204 bool 205 206config ARCH_CORRECT_STACKTRACE_ON_KRETPROBE 207 bool 208 help 209 Since kretprobes modifies return address on the stack, the 210 stacktrace may see the kretprobe trampoline address instead 211 of correct one. If the architecture stacktrace code and 212 unwinder can adjust such entries, select this configuration. 213 214config HAVE_FUNCTION_ERROR_INJECTION 215 bool 216 217config HAVE_NMI 218 bool 219 220config HAVE_FUNCTION_DESCRIPTORS 221 bool 222 223config TRACE_IRQFLAGS_SUPPORT 224 bool 225 226# 227# An arch should select this if it provides all these things: 228# 229# task_pt_regs() in asm/processor.h or asm/ptrace.h 230# arch_has_single_step() if there is hardware single-step support 231# arch_has_block_step() if there is hardware block-step support 232# asm/syscall.h supplying asm-generic/syscall.h interface 233# linux/regset.h user_regset interfaces 234# CORE_DUMP_USE_REGSET #define'd in linux/elf.h 235# TIF_SYSCALL_TRACE calls ptrace_report_syscall_{entry,exit} 236# TIF_NOTIFY_RESUME calls resume_user_mode_work() 237# 238config HAVE_ARCH_TRACEHOOK 239 bool 240 241config HAVE_DMA_CONTIGUOUS 242 bool 243 244config GENERIC_SMP_IDLE_THREAD 245 bool 246 247config GENERIC_IDLE_POLL_SETUP 248 bool 249 250config ARCH_HAS_FORTIFY_SOURCE 251 bool 252 help 253 An architecture should select this when it can successfully 254 build and run with CONFIG_FORTIFY_SOURCE. 255 256# 257# Select if the arch provides a historic keepinit alias for the retain_initrd 258# command line option 259# 260config ARCH_HAS_KEEPINITRD 261 bool 262 263# Select if arch has all set_memory_ro/rw/x/nx() functions in asm/cacheflush.h 264config ARCH_HAS_SET_MEMORY 265 bool 266 267# Select if arch has all set_direct_map_invalid/default() functions 268config ARCH_HAS_SET_DIRECT_MAP 269 bool 270 271# 272# Select if the architecture provides the arch_dma_set_uncached symbol to 273# either provide an uncached segment alias for a DMA allocation, or 274# to remap the page tables in place. 275# 276config ARCH_HAS_DMA_SET_UNCACHED 277 bool 278 279# 280# Select if the architectures provides the arch_dma_clear_uncached symbol 281# to undo an in-place page table remap for uncached access. 282# 283config ARCH_HAS_DMA_CLEAR_UNCACHED 284 bool 285 286# Select if arch init_task must go in the __init_task_data section 287config ARCH_TASK_STRUCT_ON_STACK 288 bool 289 290# Select if arch has its private alloc_task_struct() function 291config ARCH_TASK_STRUCT_ALLOCATOR 292 bool 293 294config HAVE_ARCH_THREAD_STRUCT_WHITELIST 295 bool 296 depends on !ARCH_TASK_STRUCT_ALLOCATOR 297 help 298 An architecture should select this to provide hardened usercopy 299 knowledge about what region of the thread_struct should be 300 whitelisted for copying to userspace. Normally this is only the 301 FPU registers. Specifically, arch_thread_struct_whitelist() 302 should be implemented. Without this, the entire thread_struct 303 field in task_struct will be left whitelisted. 304 305# Select if arch has its private alloc_thread_stack() function 306config ARCH_THREAD_STACK_ALLOCATOR 307 bool 308 309# Select if arch wants to size task_struct dynamically via arch_task_struct_size: 310config ARCH_WANTS_DYNAMIC_TASK_STRUCT 311 bool 312 313config ARCH_WANTS_NO_INSTR 314 bool 315 help 316 An architecture should select this if the noinstr macro is being used on 317 functions to denote that the toolchain should avoid instrumenting such 318 functions and is required for correctness. 319 320config ARCH_32BIT_OFF_T 321 bool 322 depends on !64BIT 323 help 324 All new 32-bit architectures should have 64-bit off_t type on 325 userspace side which corresponds to the loff_t kernel type. This 326 is the requirement for modern ABIs. Some existing architectures 327 still support 32-bit off_t. This option is enabled for all such 328 architectures explicitly. 329 330# Selected by 64 bit architectures which have a 32 bit f_tinode in struct ustat 331config ARCH_32BIT_USTAT_F_TINODE 332 bool 333 334config HAVE_ASM_MODVERSIONS 335 bool 336 help 337 This symbol should be selected by an architecture if it provides 338 <asm/asm-prototypes.h> to support the module versioning for symbols 339 exported from assembly code. 340 341config HAVE_REGS_AND_STACK_ACCESS_API 342 bool 343 help 344 This symbol should be selected by an architecture if it supports 345 the API needed to access registers and stack entries from pt_regs, 346 declared in asm/ptrace.h 347 For example the kprobes-based event tracer needs this API. 348 349config HAVE_RSEQ 350 bool 351 depends on HAVE_REGS_AND_STACK_ACCESS_API 352 help 353 This symbol should be selected by an architecture if it 354 supports an implementation of restartable sequences. 355 356config HAVE_FUNCTION_ARG_ACCESS_API 357 bool 358 help 359 This symbol should be selected by an architecture if it supports 360 the API needed to access function arguments from pt_regs, 361 declared in asm/ptrace.h 362 363config HAVE_HW_BREAKPOINT 364 bool 365 depends on PERF_EVENTS 366 367config HAVE_MIXED_BREAKPOINTS_REGS 368 bool 369 depends on HAVE_HW_BREAKPOINT 370 help 371 Depending on the arch implementation of hardware breakpoints, 372 some of them have separate registers for data and instruction 373 breakpoints addresses, others have mixed registers to store 374 them but define the access type in a control register. 375 Select this option if your arch implements breakpoints under the 376 latter fashion. 377 378config HAVE_USER_RETURN_NOTIFIER 379 bool 380 381config HAVE_PERF_EVENTS_NMI 382 bool 383 help 384 System hardware can generate an NMI using the perf event 385 subsystem. Also has support for calculating CPU cycle events 386 to determine how many clock cycles in a given period. 387 388config HAVE_HARDLOCKUP_DETECTOR_PERF 389 bool 390 depends on HAVE_PERF_EVENTS_NMI 391 help 392 The arch chooses to use the generic perf-NMI-based hardlockup 393 detector. Must define HAVE_PERF_EVENTS_NMI. 394 395config HAVE_NMI_WATCHDOG 396 depends on HAVE_NMI 397 bool 398 help 399 The arch provides a low level NMI watchdog. It provides 400 asm/nmi.h, and defines its own arch_touch_nmi_watchdog(). 401 402config HAVE_HARDLOCKUP_DETECTOR_ARCH 403 bool 404 select HAVE_NMI_WATCHDOG 405 help 406 The arch chooses to provide its own hardlockup detector, which is 407 a superset of the HAVE_NMI_WATCHDOG. It also conforms to config 408 interfaces and parameters provided by hardlockup detector subsystem. 409 410config HAVE_PERF_REGS 411 bool 412 help 413 Support selective register dumps for perf events. This includes 414 bit-mapping of each registers and a unique architecture id. 415 416config HAVE_PERF_USER_STACK_DUMP 417 bool 418 help 419 Support user stack dumps for perf event samples. This needs 420 access to the user stack pointer which is not unified across 421 architectures. 422 423config HAVE_ARCH_JUMP_LABEL 424 bool 425 426config HAVE_ARCH_JUMP_LABEL_RELATIVE 427 bool 428 429config MMU_GATHER_TABLE_FREE 430 bool 431 432config MMU_GATHER_RCU_TABLE_FREE 433 bool 434 select MMU_GATHER_TABLE_FREE 435 436config MMU_GATHER_PAGE_SIZE 437 bool 438 439config MMU_GATHER_NO_RANGE 440 bool 441 442config MMU_GATHER_NO_GATHER 443 bool 444 depends on MMU_GATHER_TABLE_FREE 445 446config ARCH_WANT_IRQS_OFF_ACTIVATE_MM 447 bool 448 help 449 Temporary select until all architectures can be converted to have 450 irqs disabled over activate_mm. Architectures that do IPI based TLB 451 shootdowns should enable this. 452 453config ARCH_HAVE_NMI_SAFE_CMPXCHG 454 bool 455 456config HAVE_ALIGNED_STRUCT_PAGE 457 bool 458 help 459 This makes sure that struct pages are double word aligned and that 460 e.g. the SLUB allocator can perform double word atomic operations 461 on a struct page for better performance. However selecting this 462 might increase the size of a struct page by a word. 463 464config HAVE_CMPXCHG_LOCAL 465 bool 466 467config HAVE_CMPXCHG_DOUBLE 468 bool 469 470config ARCH_WEAK_RELEASE_ACQUIRE 471 bool 472 473config ARCH_WANT_IPC_PARSE_VERSION 474 bool 475 476config ARCH_WANT_COMPAT_IPC_PARSE_VERSION 477 bool 478 479config ARCH_WANT_OLD_COMPAT_IPC 480 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION 481 bool 482 483config HAVE_ARCH_SECCOMP 484 bool 485 help 486 An arch should select this symbol to support seccomp mode 1 (the fixed 487 syscall policy), and must provide an overrides for __NR_seccomp_sigreturn, 488 and compat syscalls if the asm-generic/seccomp.h defaults need adjustment: 489 - __NR_seccomp_read_32 490 - __NR_seccomp_write_32 491 - __NR_seccomp_exit_32 492 - __NR_seccomp_sigreturn_32 493 494config HAVE_ARCH_SECCOMP_FILTER 495 bool 496 select HAVE_ARCH_SECCOMP 497 help 498 An arch should select this symbol if it provides all of these things: 499 - all the requirements for HAVE_ARCH_SECCOMP 500 - syscall_get_arch() 501 - syscall_get_arguments() 502 - syscall_rollback() 503 - syscall_set_return_value() 504 - SIGSYS siginfo_t support 505 - secure_computing is called from a ptrace_event()-safe context 506 - secure_computing return value is checked and a return value of -1 507 results in the system call being skipped immediately. 508 - seccomp syscall wired up 509 - if !HAVE_SPARSE_SYSCALL_NR, have SECCOMP_ARCH_NATIVE, 510 SECCOMP_ARCH_NATIVE_NR, SECCOMP_ARCH_NATIVE_NAME defined. If 511 COMPAT is supported, have the SECCOMP_ARCH_COMPAT* defines too. 512 513config SECCOMP 514 prompt "Enable seccomp to safely execute untrusted bytecode" 515 def_bool y 516 depends on HAVE_ARCH_SECCOMP 517 help 518 This kernel feature is useful for number crunching applications 519 that may need to handle untrusted bytecode during their 520 execution. By using pipes or other transports made available 521 to the process as file descriptors supporting the read/write 522 syscalls, it's possible to isolate those applications in their 523 own address space using seccomp. Once seccomp is enabled via 524 prctl(PR_SET_SECCOMP) or the seccomp() syscall, it cannot be 525 disabled and the task is only allowed to execute a few safe 526 syscalls defined by each seccomp mode. 527 528 If unsure, say Y. 529 530config SECCOMP_FILTER 531 def_bool y 532 depends on HAVE_ARCH_SECCOMP_FILTER && SECCOMP && NET 533 help 534 Enable tasks to build secure computing environments defined 535 in terms of Berkeley Packet Filter programs which implement 536 task-defined system call filtering polices. 537 538 See Documentation/userspace-api/seccomp_filter.rst for details. 539 540config SECCOMP_CACHE_DEBUG 541 bool "Show seccomp filter cache status in /proc/pid/seccomp_cache" 542 depends on SECCOMP_FILTER && !HAVE_SPARSE_SYSCALL_NR 543 depends on PROC_FS 544 help 545 This enables the /proc/pid/seccomp_cache interface to monitor 546 seccomp cache data. The file format is subject to change. Reading 547 the file requires CAP_SYS_ADMIN. 548 549 This option is for debugging only. Enabling presents the risk that 550 an adversary may be able to infer the seccomp filter logic. 551 552 If unsure, say N. 553 554config HAVE_ARCH_STACKLEAK 555 bool 556 help 557 An architecture should select this if it has the code which 558 fills the used part of the kernel stack with the STACKLEAK_POISON 559 value before returning from system calls. 560 561config HAVE_STACKPROTECTOR 562 bool 563 help 564 An arch should select this symbol if: 565 - it has implemented a stack canary (e.g. __stack_chk_guard) 566 567config STACKPROTECTOR 568 bool "Stack Protector buffer overflow detection" 569 depends on HAVE_STACKPROTECTOR 570 depends on $(cc-option,-fstack-protector) 571 default y 572 help 573 This option turns on the "stack-protector" GCC feature. This 574 feature puts, at the beginning of functions, a canary value on 575 the stack just before the return address, and validates 576 the value just before actually returning. Stack based buffer 577 overflows (that need to overwrite this return address) now also 578 overwrite the canary, which gets detected and the attack is then 579 neutralized via a kernel panic. 580 581 Functions will have the stack-protector canary logic added if they 582 have an 8-byte or larger character array on the stack. 583 584 This feature requires gcc version 4.2 or above, or a distribution 585 gcc with the feature backported ("-fstack-protector"). 586 587 On an x86 "defconfig" build, this feature adds canary checks to 588 about 3% of all kernel functions, which increases kernel code size 589 by about 0.3%. 590 591config STACKPROTECTOR_STRONG 592 bool "Strong Stack Protector" 593 depends on STACKPROTECTOR 594 depends on $(cc-option,-fstack-protector-strong) 595 default y 596 help 597 Functions will have the stack-protector canary logic added in any 598 of the following conditions: 599 600 - local variable's address used as part of the right hand side of an 601 assignment or function argument 602 - local variable is an array (or union containing an array), 603 regardless of array type or length 604 - uses register local variables 605 606 This feature requires gcc version 4.9 or above, or a distribution 607 gcc with the feature backported ("-fstack-protector-strong"). 608 609 On an x86 "defconfig" build, this feature adds canary checks to 610 about 20% of all kernel functions, which increases the kernel code 611 size by about 2%. 612 613config ARCH_SUPPORTS_SHADOW_CALL_STACK 614 bool 615 help 616 An architecture should select this if it supports the compiler's 617 Shadow Call Stack and implements runtime support for shadow stack 618 switching. 619 620config SHADOW_CALL_STACK 621 bool "Shadow Call Stack" 622 depends on ARCH_SUPPORTS_SHADOW_CALL_STACK 623 depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER 624 help 625 This option enables the compiler's Shadow Call Stack, which 626 uses a shadow stack to protect function return addresses from 627 being overwritten by an attacker. More information can be found 628 in the compiler's documentation: 629 630 - Clang: https://clang.llvm.org/docs/ShadowCallStack.html 631 - GCC: https://gcc.gnu.org/onlinedocs/gcc/Instrumentation-Options.html#Instrumentation-Options 632 633 Note that security guarantees in the kernel differ from the 634 ones documented for user space. The kernel must store addresses 635 of shadow stacks in memory, which means an attacker capable of 636 reading and writing arbitrary memory may be able to locate them 637 and hijack control flow by modifying the stacks. 638 639config LTO 640 bool 641 help 642 Selected if the kernel will be built using the compiler's LTO feature. 643 644config LTO_CLANG 645 bool 646 select LTO 647 help 648 Selected if the kernel will be built using Clang's LTO feature. 649 650config ARCH_SUPPORTS_LTO_CLANG 651 bool 652 help 653 An architecture should select this option if it supports: 654 - compiling with Clang, 655 - compiling inline assembly with Clang's integrated assembler, 656 - and linking with LLD. 657 658config ARCH_SUPPORTS_LTO_CLANG_THIN 659 bool 660 help 661 An architecture should select this option if it can support Clang's 662 ThinLTO mode. 663 664config HAS_LTO_CLANG 665 def_bool y 666 depends on CC_IS_CLANG && LD_IS_LLD && AS_IS_LLVM 667 depends on $(success,$(NM) --help | head -n 1 | grep -qi llvm) 668 depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm) 669 depends on ARCH_SUPPORTS_LTO_CLANG 670 depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT 671 depends on !KASAN || KASAN_HW_TAGS 672 depends on !GCOV_KERNEL 673 help 674 The compiler and Kconfig options support building with Clang's 675 LTO. 676 677choice 678 prompt "Link Time Optimization (LTO)" 679 default LTO_NONE 680 help 681 This option enables Link Time Optimization (LTO), which allows the 682 compiler to optimize binaries globally. 683 684 If unsure, select LTO_NONE. Note that LTO is very resource-intensive 685 so it's disabled by default. 686 687config LTO_NONE 688 bool "None" 689 help 690 Build the kernel normally, without Link Time Optimization (LTO). 691 692config LTO_CLANG_FULL 693 bool "Clang Full LTO (EXPERIMENTAL)" 694 depends on HAS_LTO_CLANG 695 depends on !COMPILE_TEST 696 select LTO_CLANG 697 help 698 This option enables Clang's full Link Time Optimization (LTO), which 699 allows the compiler to optimize the kernel globally. If you enable 700 this option, the compiler generates LLVM bitcode instead of ELF 701 object files, and the actual compilation from bitcode happens at 702 the LTO link step, which may take several minutes depending on the 703 kernel configuration. More information can be found from LLVM's 704 documentation: 705 706 https://llvm.org/docs/LinkTimeOptimization.html 707 708 During link time, this option can use a large amount of RAM, and 709 may take much longer than the ThinLTO option. 710 711config LTO_CLANG_THIN 712 bool "Clang ThinLTO (EXPERIMENTAL)" 713 depends on HAS_LTO_CLANG && ARCH_SUPPORTS_LTO_CLANG_THIN 714 select LTO_CLANG 715 help 716 This option enables Clang's ThinLTO, which allows for parallel 717 optimization and faster incremental compiles compared to the 718 CONFIG_LTO_CLANG_FULL option. More information can be found 719 from Clang's documentation: 720 721 https://clang.llvm.org/docs/ThinLTO.html 722 723 If unsure, say Y. 724endchoice 725 726config ARCH_SUPPORTS_CFI_CLANG 727 bool 728 help 729 An architecture should select this option if it can support Clang's 730 Control-Flow Integrity (CFI) checking. 731 732config CFI_CLANG 733 bool "Use Clang's Control Flow Integrity (CFI)" 734 depends on LTO_CLANG && ARCH_SUPPORTS_CFI_CLANG 735 depends on CLANG_VERSION >= 140000 736 select KALLSYMS 737 help 738 This option enables Clang’s forward-edge Control Flow Integrity 739 (CFI) checking, where the compiler injects a runtime check to each 740 indirect function call to ensure the target is a valid function with 741 the correct static type. This restricts possible call targets and 742 makes it more difficult for an attacker to exploit bugs that allow 743 the modification of stored function pointers. More information can be 744 found from Clang's documentation: 745 746 https://clang.llvm.org/docs/ControlFlowIntegrity.html 747 748config CFI_CLANG_SHADOW 749 bool "Use CFI shadow to speed up cross-module checks" 750 default y 751 depends on CFI_CLANG && MODULES 752 help 753 If you select this option, the kernel builds a fast look-up table of 754 CFI check functions in loaded modules to reduce performance overhead. 755 756 If unsure, say Y. 757 758config CFI_PERMISSIVE 759 bool "Use CFI in permissive mode" 760 depends on CFI_CLANG 761 help 762 When selected, Control Flow Integrity (CFI) violations result in a 763 warning instead of a kernel panic. This option should only be used 764 for finding indirect call type mismatches during development. 765 766 If unsure, say N. 767 768config HAVE_ARCH_WITHIN_STACK_FRAMES 769 bool 770 help 771 An architecture should select this if it can walk the kernel stack 772 frames to determine if an object is part of either the arguments 773 or local variables (i.e. that it excludes saved return addresses, 774 and similar) by implementing an inline arch_within_stack_frames(), 775 which is used by CONFIG_HARDENED_USERCOPY. 776 777config HAVE_CONTEXT_TRACKING 778 bool 779 help 780 Provide kernel/user boundaries probes necessary for subsystems 781 that need it, such as userspace RCU extended quiescent state. 782 Syscalls need to be wrapped inside user_exit()-user_enter(), either 783 optimized behind static key or through the slow path using TIF_NOHZ 784 flag. Exceptions handlers must be wrapped as well. Irqs are already 785 protected inside rcu_irq_enter/rcu_irq_exit() but preemption or signal 786 handling on irq exit still need to be protected. 787 788config HAVE_CONTEXT_TRACKING_OFFSTACK 789 bool 790 help 791 Architecture neither relies on exception_enter()/exception_exit() 792 nor on schedule_user(). Also preempt_schedule_notrace() and 793 preempt_schedule_irq() can't be called in a preemptible section 794 while context tracking is CONTEXT_USER. This feature reflects a sane 795 entry implementation where the following requirements are met on 796 critical entry code, ie: before user_exit() or after user_enter(): 797 798 - Critical entry code isn't preemptible (or better yet: 799 not interruptible). 800 - No use of RCU read side critical sections, unless rcu_nmi_enter() 801 got called. 802 - No use of instrumentation, unless instrumentation_begin() got 803 called. 804 805config HAVE_TIF_NOHZ 806 bool 807 help 808 Arch relies on TIF_NOHZ and syscall slow path to implement context 809 tracking calls to user_enter()/user_exit(). 810 811config HAVE_VIRT_CPU_ACCOUNTING 812 bool 813 814config HAVE_VIRT_CPU_ACCOUNTING_IDLE 815 bool 816 help 817 Architecture has its own way to account idle CPU time and therefore 818 doesn't implement vtime_account_idle(). 819 820config ARCH_HAS_SCALED_CPUTIME 821 bool 822 823config HAVE_VIRT_CPU_ACCOUNTING_GEN 824 bool 825 default y if 64BIT 826 help 827 With VIRT_CPU_ACCOUNTING_GEN, cputime_t becomes 64-bit. 828 Before enabling this option, arch code must be audited 829 to ensure there are no races in concurrent read/write of 830 cputime_t. For example, reading/writing 64-bit cputime_t on 831 some 32-bit arches may require multiple accesses, so proper 832 locking is needed to protect against concurrent accesses. 833 834config HAVE_IRQ_TIME_ACCOUNTING 835 bool 836 help 837 Archs need to ensure they use a high enough resolution clock to 838 support irq time accounting and then call enable_sched_clock_irqtime(). 839 840config HAVE_MOVE_PUD 841 bool 842 help 843 Architectures that select this are able to move page tables at the 844 PUD level. If there are only 3 page table levels, the move effectively 845 happens at the PGD level. 846 847config HAVE_MOVE_PMD 848 bool 849 help 850 Archs that select this are able to move page tables at the PMD level. 851 852config HAVE_ARCH_TRANSPARENT_HUGEPAGE 853 bool 854 855config HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD 856 bool 857 858config HAVE_ARCH_HUGE_VMAP 859 bool 860 861# 862# Archs that select this would be capable of PMD-sized vmaps (i.e., 863# arch_vmap_pmd_supported() returns true). The VM_ALLOW_HUGE_VMAP flag 864# must be used to enable allocations to use hugepages. 865# 866config HAVE_ARCH_HUGE_VMALLOC 867 depends on HAVE_ARCH_HUGE_VMAP 868 bool 869 870config ARCH_WANT_HUGE_PMD_SHARE 871 bool 872 873config HAVE_ARCH_SOFT_DIRTY 874 bool 875 876config HAVE_MOD_ARCH_SPECIFIC 877 bool 878 help 879 The arch uses struct mod_arch_specific to store data. Many arches 880 just need a simple module loader without arch specific data - those 881 should not enable this. 882 883config MODULES_USE_ELF_RELA 884 bool 885 help 886 Modules only use ELF RELA relocations. Modules with ELF REL 887 relocations will give an error. 888 889config MODULES_USE_ELF_REL 890 bool 891 help 892 Modules only use ELF REL relocations. Modules with ELF RELA 893 relocations will give an error. 894 895config ARCH_WANTS_MODULES_DATA_IN_VMALLOC 896 bool 897 help 898 For architectures like powerpc/32 which have constraints on module 899 allocation and need to allocate module data outside of module area. 900 901config HAVE_IRQ_EXIT_ON_IRQ_STACK 902 bool 903 help 904 Architecture doesn't only execute the irq handler on the irq stack 905 but also irq_exit(). This way we can process softirqs on this irq 906 stack instead of switching to a new one when we call __do_softirq() 907 in the end of an hardirq. 908 This spares a stack switch and improves cache usage on softirq 909 processing. 910 911config HAVE_SOFTIRQ_ON_OWN_STACK 912 bool 913 help 914 Architecture provides a function to run __do_softirq() on a 915 separate stack. 916 917config ALTERNATE_USER_ADDRESS_SPACE 918 bool 919 help 920 Architectures set this when the CPU uses separate address 921 spaces for kernel and user space pointers. In this case, the 922 access_ok() check on a __user pointer is skipped. 923 924config PGTABLE_LEVELS 925 int 926 default 2 927 928config ARCH_HAS_ELF_RANDOMIZE 929 bool 930 help 931 An architecture supports choosing randomized locations for 932 stack, mmap, brk, and ET_DYN. Defined functions: 933 - arch_mmap_rnd() 934 - arch_randomize_brk() 935 936config HAVE_ARCH_MMAP_RND_BITS 937 bool 938 help 939 An arch should select this symbol if it supports setting a variable 940 number of bits for use in establishing the base address for mmap 941 allocations, has MMU enabled and provides values for both: 942 - ARCH_MMAP_RND_BITS_MIN 943 - ARCH_MMAP_RND_BITS_MAX 944 945config HAVE_EXIT_THREAD 946 bool 947 help 948 An architecture implements exit_thread. 949 950config ARCH_MMAP_RND_BITS_MIN 951 int 952 953config ARCH_MMAP_RND_BITS_MAX 954 int 955 956config ARCH_MMAP_RND_BITS_DEFAULT 957 int 958 959config ARCH_MMAP_RND_BITS 960 int "Number of bits to use for ASLR of mmap base address" if EXPERT 961 range ARCH_MMAP_RND_BITS_MIN ARCH_MMAP_RND_BITS_MAX 962 default ARCH_MMAP_RND_BITS_DEFAULT if ARCH_MMAP_RND_BITS_DEFAULT 963 default ARCH_MMAP_RND_BITS_MIN 964 depends on HAVE_ARCH_MMAP_RND_BITS 965 help 966 This value can be used to select the number of bits to use to 967 determine the random offset to the base address of vma regions 968 resulting from mmap allocations. This value will be bounded 969 by the architecture's minimum and maximum supported values. 970 971 This value can be changed after boot using the 972 /proc/sys/vm/mmap_rnd_bits tunable 973 974config HAVE_ARCH_MMAP_RND_COMPAT_BITS 975 bool 976 help 977 An arch should select this symbol if it supports running applications 978 in compatibility mode, supports setting a variable number of bits for 979 use in establishing the base address for mmap allocations, has MMU 980 enabled and provides values for both: 981 - ARCH_MMAP_RND_COMPAT_BITS_MIN 982 - ARCH_MMAP_RND_COMPAT_BITS_MAX 983 984config ARCH_MMAP_RND_COMPAT_BITS_MIN 985 int 986 987config ARCH_MMAP_RND_COMPAT_BITS_MAX 988 int 989 990config ARCH_MMAP_RND_COMPAT_BITS_DEFAULT 991 int 992 993config ARCH_MMAP_RND_COMPAT_BITS 994 int "Number of bits to use for ASLR of mmap base address for compatible applications" if EXPERT 995 range ARCH_MMAP_RND_COMPAT_BITS_MIN ARCH_MMAP_RND_COMPAT_BITS_MAX 996 default ARCH_MMAP_RND_COMPAT_BITS_DEFAULT if ARCH_MMAP_RND_COMPAT_BITS_DEFAULT 997 default ARCH_MMAP_RND_COMPAT_BITS_MIN 998 depends on HAVE_ARCH_MMAP_RND_COMPAT_BITS 999 help 1000 This value can be used to select the number of bits to use to 1001 determine the random offset to the base address of vma regions 1002 resulting from mmap allocations for compatible applications This 1003 value will be bounded by the architecture's minimum and maximum 1004 supported values. 1005 1006 This value can be changed after boot using the 1007 /proc/sys/vm/mmap_rnd_compat_bits tunable 1008 1009config HAVE_ARCH_COMPAT_MMAP_BASES 1010 bool 1011 help 1012 This allows 64bit applications to invoke 32-bit mmap() syscall 1013 and vice-versa 32-bit applications to call 64-bit mmap(). 1014 Required for applications doing different bitness syscalls. 1015 1016config PAGE_SIZE_LESS_THAN_64KB 1017 def_bool y 1018 depends on !ARM64_64K_PAGES 1019 depends on !IA64_PAGE_SIZE_64KB 1020 depends on !PAGE_SIZE_64KB 1021 depends on !PARISC_PAGE_SIZE_64KB 1022 depends on PAGE_SIZE_LESS_THAN_256KB 1023 1024config PAGE_SIZE_LESS_THAN_256KB 1025 def_bool y 1026 depends on !PAGE_SIZE_256KB 1027 1028# This allows to use a set of generic functions to determine mmap base 1029# address by giving priority to top-down scheme only if the process 1030# is not in legacy mode (compat task, unlimited stack size or 1031# sysctl_legacy_va_layout). 1032# Architecture that selects this option can provide its own version of: 1033# - STACK_RND_MASK 1034config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 1035 bool 1036 depends on MMU 1037 select ARCH_HAS_ELF_RANDOMIZE 1038 1039config HAVE_OBJTOOL 1040 bool 1041 1042config HAVE_JUMP_LABEL_HACK 1043 bool 1044 1045config HAVE_NOINSTR_HACK 1046 bool 1047 1048config HAVE_NOINSTR_VALIDATION 1049 bool 1050 1051config HAVE_UACCESS_VALIDATION 1052 bool 1053 select OBJTOOL 1054 1055config HAVE_STACK_VALIDATION 1056 bool 1057 help 1058 Architecture supports objtool compile-time frame pointer rule 1059 validation. 1060 1061config HAVE_RELIABLE_STACKTRACE 1062 bool 1063 help 1064 Architecture has either save_stack_trace_tsk_reliable() or 1065 arch_stack_walk_reliable() function which only returns a stack trace 1066 if it can guarantee the trace is reliable. 1067 1068config HAVE_ARCH_HASH 1069 bool 1070 default n 1071 help 1072 If this is set, the architecture provides an <asm/hash.h> 1073 file which provides platform-specific implementations of some 1074 functions in <linux/hash.h> or fs/namei.c. 1075 1076config HAVE_ARCH_NVRAM_OPS 1077 bool 1078 1079config ISA_BUS_API 1080 def_bool ISA 1081 1082# 1083# ABI hall of shame 1084# 1085config CLONE_BACKWARDS 1086 bool 1087 help 1088 Architecture has tls passed as the 4th argument of clone(2), 1089 not the 5th one. 1090 1091config CLONE_BACKWARDS2 1092 bool 1093 help 1094 Architecture has the first two arguments of clone(2) swapped. 1095 1096config CLONE_BACKWARDS3 1097 bool 1098 help 1099 Architecture has tls passed as the 3rd argument of clone(2), 1100 not the 5th one. 1101 1102config ODD_RT_SIGACTION 1103 bool 1104 help 1105 Architecture has unusual rt_sigaction(2) arguments 1106 1107config OLD_SIGSUSPEND 1108 bool 1109 help 1110 Architecture has old sigsuspend(2) syscall, of one-argument variety 1111 1112config OLD_SIGSUSPEND3 1113 bool 1114 help 1115 Even weirder antique ABI - three-argument sigsuspend(2) 1116 1117config OLD_SIGACTION 1118 bool 1119 help 1120 Architecture has old sigaction(2) syscall. Nope, not the same 1121 as OLD_SIGSUSPEND | OLD_SIGSUSPEND3 - alpha has sigsuspend(2), 1122 but fairly different variant of sigaction(2), thanks to OSF/1 1123 compatibility... 1124 1125config COMPAT_OLD_SIGACTION 1126 bool 1127 1128config COMPAT_32BIT_TIME 1129 bool "Provide system calls for 32-bit time_t" 1130 default !64BIT || COMPAT 1131 help 1132 This enables 32 bit time_t support in addition to 64 bit time_t support. 1133 This is relevant on all 32-bit architectures, and 64-bit architectures 1134 as part of compat syscall handling. 1135 1136config ARCH_NO_PREEMPT 1137 bool 1138 1139config ARCH_EPHEMERAL_INODES 1140 def_bool n 1141 help 1142 An arch should select this symbol if it doesn't keep track of inode 1143 instances on its own, but instead relies on something else (e.g. the 1144 host kernel for an UML kernel). 1145 1146config ARCH_SUPPORTS_RT 1147 bool 1148 1149config CPU_NO_EFFICIENT_FFS 1150 def_bool n 1151 1152config HAVE_ARCH_VMAP_STACK 1153 def_bool n 1154 help 1155 An arch should select this symbol if it can support kernel stacks 1156 in vmalloc space. This means: 1157 1158 - vmalloc space must be large enough to hold many kernel stacks. 1159 This may rule out many 32-bit architectures. 1160 1161 - Stacks in vmalloc space need to work reliably. For example, if 1162 vmap page tables are created on demand, either this mechanism 1163 needs to work while the stack points to a virtual address with 1164 unpopulated page tables or arch code (switch_to() and switch_mm(), 1165 most likely) needs to ensure that the stack's page table entries 1166 are populated before running on a possibly unpopulated stack. 1167 1168 - If the stack overflows into a guard page, something reasonable 1169 should happen. The definition of "reasonable" is flexible, but 1170 instantly rebooting without logging anything would be unfriendly. 1171 1172config VMAP_STACK 1173 default y 1174 bool "Use a virtually-mapped stack" 1175 depends on HAVE_ARCH_VMAP_STACK 1176 depends on !KASAN || KASAN_HW_TAGS || KASAN_VMALLOC 1177 help 1178 Enable this if you want the use virtually-mapped kernel stacks 1179 with guard pages. This causes kernel stack overflows to be 1180 caught immediately rather than causing difficult-to-diagnose 1181 corruption. 1182 1183 To use this with software KASAN modes, the architecture must support 1184 backing virtual mappings with real shadow memory, and KASAN_VMALLOC 1185 must be enabled. 1186 1187config HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 1188 def_bool n 1189 help 1190 An arch should select this symbol if it can support kernel stack 1191 offset randomization with calls to add_random_kstack_offset() 1192 during syscall entry and choose_random_kstack_offset() during 1193 syscall exit. Careful removal of -fstack-protector-strong and 1194 -fstack-protector should also be applied to the entry code and 1195 closely examined, as the artificial stack bump looks like an array 1196 to the compiler, so it will attempt to add canary checks regardless 1197 of the static branch state. 1198 1199config RANDOMIZE_KSTACK_OFFSET 1200 bool "Support for randomizing kernel stack offset on syscall entry" if EXPERT 1201 default y 1202 depends on HAVE_ARCH_RANDOMIZE_KSTACK_OFFSET 1203 depends on INIT_STACK_NONE || !CC_IS_CLANG || CLANG_VERSION >= 140000 1204 help 1205 The kernel stack offset can be randomized (after pt_regs) by 1206 roughly 5 bits of entropy, frustrating memory corruption 1207 attacks that depend on stack address determinism or 1208 cross-syscall address exposures. 1209 1210 The feature is controlled via the "randomize_kstack_offset=on/off" 1211 kernel boot param, and if turned off has zero overhead due to its use 1212 of static branches (see JUMP_LABEL). 1213 1214 If unsure, say Y. 1215 1216config RANDOMIZE_KSTACK_OFFSET_DEFAULT 1217 bool "Default state of kernel stack offset randomization" 1218 depends on RANDOMIZE_KSTACK_OFFSET 1219 help 1220 Kernel stack offset randomization is controlled by kernel boot param 1221 "randomize_kstack_offset=on/off", and this config chooses the default 1222 boot state. 1223 1224config ARCH_OPTIONAL_KERNEL_RWX 1225 def_bool n 1226 1227config ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 1228 def_bool n 1229 1230config ARCH_HAS_STRICT_KERNEL_RWX 1231 def_bool n 1232 1233config STRICT_KERNEL_RWX 1234 bool "Make kernel text and rodata read-only" if ARCH_OPTIONAL_KERNEL_RWX 1235 depends on ARCH_HAS_STRICT_KERNEL_RWX 1236 default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 1237 help 1238 If this is set, kernel text and rodata memory will be made read-only, 1239 and non-text memory will be made non-executable. This provides 1240 protection against certain security exploits (e.g. executing the heap 1241 or modifying text) 1242 1243 These features are considered standard security practice these days. 1244 You should say Y here in almost all cases. 1245 1246config ARCH_HAS_STRICT_MODULE_RWX 1247 def_bool n 1248 1249config STRICT_MODULE_RWX 1250 bool "Set loadable kernel module data as NX and text as RO" if ARCH_OPTIONAL_KERNEL_RWX 1251 depends on ARCH_HAS_STRICT_MODULE_RWX && MODULES 1252 default !ARCH_OPTIONAL_KERNEL_RWX || ARCH_OPTIONAL_KERNEL_RWX_DEFAULT 1253 help 1254 If this is set, module text and rodata memory will be made read-only, 1255 and non-text memory will be made non-executable. This provides 1256 protection against certain security exploits (e.g. writing to text) 1257 1258# select if the architecture provides an asm/dma-direct.h header 1259config ARCH_HAS_PHYS_TO_DMA 1260 bool 1261 1262config HAVE_ARCH_COMPILER_H 1263 bool 1264 help 1265 An architecture can select this if it provides an 1266 asm/compiler.h header that should be included after 1267 linux/compiler-*.h in order to override macro definitions that those 1268 headers generally provide. 1269 1270config HAVE_ARCH_PREL32_RELOCATIONS 1271 bool 1272 help 1273 May be selected by an architecture if it supports place-relative 1274 32-bit relocations, both in the toolchain and in the module loader, 1275 in which case relative references can be used in special sections 1276 for PCI fixup, initcalls etc which are only half the size on 64 bit 1277 architectures, and don't require runtime relocation on relocatable 1278 kernels. 1279 1280config ARCH_USE_MEMREMAP_PROT 1281 bool 1282 1283config LOCK_EVENT_COUNTS 1284 bool "Locking event counts collection" 1285 depends on DEBUG_FS 1286 help 1287 Enable light-weight counting of various locking related events 1288 in the system with minimal performance impact. This reduces 1289 the chance of application behavior change because of timing 1290 differences. The counts are reported via debugfs. 1291 1292# Select if the architecture has support for applying RELR relocations. 1293config ARCH_HAS_RELR 1294 bool 1295 1296config RELR 1297 bool "Use RELR relocation packing" 1298 depends on ARCH_HAS_RELR && TOOLS_SUPPORT_RELR 1299 default y 1300 help 1301 Store the kernel's dynamic relocations in the RELR relocation packing 1302 format. Requires a compatible linker (LLD supports this feature), as 1303 well as compatible NM and OBJCOPY utilities (llvm-nm and llvm-objcopy 1304 are compatible). 1305 1306config ARCH_HAS_MEM_ENCRYPT 1307 bool 1308 1309config ARCH_HAS_CC_PLATFORM 1310 bool 1311 1312config HAVE_SPARSE_SYSCALL_NR 1313 bool 1314 help 1315 An architecture should select this if its syscall numbering is sparse 1316 to save space. For example, MIPS architecture has a syscall array with 1317 entries at 4000, 5000 and 6000 locations. This option turns on syscall 1318 related optimizations for a given architecture. 1319 1320config ARCH_HAS_VDSO_DATA 1321 bool 1322 1323config HAVE_STATIC_CALL 1324 bool 1325 1326config HAVE_STATIC_CALL_INLINE 1327 bool 1328 depends on HAVE_STATIC_CALL 1329 select OBJTOOL 1330 1331config HAVE_PREEMPT_DYNAMIC 1332 bool 1333 1334config HAVE_PREEMPT_DYNAMIC_CALL 1335 bool 1336 depends on HAVE_STATIC_CALL 1337 select HAVE_PREEMPT_DYNAMIC 1338 help 1339 An architecture should select this if it can handle the preemption 1340 model being selected at boot time using static calls. 1341 1342 Where an architecture selects HAVE_STATIC_CALL_INLINE, any call to a 1343 preemption function will be patched directly. 1344 1345 Where an architecture does not select HAVE_STATIC_CALL_INLINE, any 1346 call to a preemption function will go through a trampoline, and the 1347 trampoline will be patched. 1348 1349 It is strongly advised to support inline static call to avoid any 1350 overhead. 1351 1352config HAVE_PREEMPT_DYNAMIC_KEY 1353 bool 1354 depends on HAVE_ARCH_JUMP_LABEL && CC_HAS_ASM_GOTO 1355 select HAVE_PREEMPT_DYNAMIC 1356 help 1357 An architecture should select this if it can handle the preemption 1358 model being selected at boot time using static keys. 1359 1360 Each preemption function will be given an early return based on a 1361 static key. This should have slightly lower overhead than non-inline 1362 static calls, as this effectively inlines each trampoline into the 1363 start of its callee. This may avoid redundant work, and may 1364 integrate better with CFI schemes. 1365 1366 This will have greater overhead than using inline static calls as 1367 the call to the preemption function cannot be entirely elided. 1368 1369config ARCH_WANT_LD_ORPHAN_WARN 1370 bool 1371 help 1372 An arch should select this symbol once all linker sections are explicitly 1373 included, size-asserted, or discarded in the linker scripts. This is 1374 important because we never want expected sections to be placed heuristically 1375 by the linker, since the locations of such sections can change between linker 1376 versions. 1377 1378config HAVE_ARCH_PFN_VALID 1379 bool 1380 1381config ARCH_SUPPORTS_DEBUG_PAGEALLOC 1382 bool 1383 1384config ARCH_SUPPORTS_PAGE_TABLE_CHECK 1385 bool 1386 1387config ARCH_SPLIT_ARG64 1388 bool 1389 help 1390 If a 32-bit architecture requires 64-bit arguments to be split into 1391 pairs of 32-bit arguments, select this option. 1392 1393config ARCH_HAS_ELFCORE_COMPAT 1394 bool 1395 1396config ARCH_HAS_PARANOID_L1D_FLUSH 1397 bool 1398 1399config DYNAMIC_SIGFRAME 1400 bool 1401 1402# Select, if arch has a named attribute group bound to NUMA device nodes. 1403config HAVE_ARCH_NODE_DEV_GROUP 1404 bool 1405 1406source "kernel/gcov/Kconfig" 1407 1408source "scripts/gcc-plugins/Kconfig" 1409 1410endmenu