1# SPDX-License-Identifier: GPL-2.0-only 2config ARM64 3 def_bool y 4 select ACPI_CCA_REQUIRED if ACPI 5 select ACPI_GENERIC_GSI if ACPI 6 select ACPI_GTDT if ACPI 7 select ACPI_IORT if ACPI 8 select ACPI_REDUCED_HARDWARE_ONLY if ACPI 9 select ACPI_MCFG if (ACPI && PCI) 10 select ACPI_SPCR_TABLE if ACPI 11 select ACPI_PPTT if ACPI 12 select ARCH_HAS_DEBUG_WX 13 select ARCH_BINFMT_ELF_STATE 14 select ARCH_HAS_DEBUG_VIRTUAL 15 select ARCH_HAS_DEBUG_VM_PGTABLE 16 select ARCH_HAS_DMA_PREP_COHERENT 17 select ARCH_HAS_ACPI_TABLE_UPGRADE if ACPI 18 select ARCH_HAS_FAST_MULTIPLIER 19 select ARCH_HAS_FORTIFY_SOURCE 20 select ARCH_HAS_GCOV_PROFILE_ALL 21 select ARCH_HAS_GIGANTIC_PAGE 22 select ARCH_HAS_KCOV 23 select ARCH_HAS_KEEPINITRD 24 select ARCH_HAS_MEMBARRIER_SYNC_CORE 25 select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE 26 select ARCH_HAS_PTE_DEVMAP 27 select ARCH_HAS_PTE_SPECIAL 28 select ARCH_HAS_SETUP_DMA_OPS 29 select ARCH_HAS_SET_DIRECT_MAP 30 select ARCH_HAS_SET_MEMORY 31 select ARCH_STACKWALK 32 select ARCH_HAS_STRICT_KERNEL_RWX 33 select ARCH_HAS_STRICT_MODULE_RWX 34 select ARCH_HAS_SYNC_DMA_FOR_DEVICE 35 select ARCH_HAS_SYNC_DMA_FOR_CPU 36 select ARCH_HAS_SYSCALL_WRAPPER 37 select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT 38 select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST 39 select ARCH_HAVE_ELF_PROT 40 select ARCH_HAVE_NMI_SAFE_CMPXCHG 41 select ARCH_INLINE_READ_LOCK if !PREEMPTION 42 select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION 43 select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION 44 select ARCH_INLINE_READ_LOCK_IRQSAVE if !PREEMPTION 45 select ARCH_INLINE_READ_UNLOCK if !PREEMPTION 46 select ARCH_INLINE_READ_UNLOCK_BH if !PREEMPTION 47 select ARCH_INLINE_READ_UNLOCK_IRQ if !PREEMPTION 48 select ARCH_INLINE_READ_UNLOCK_IRQRESTORE if !PREEMPTION 49 select ARCH_INLINE_WRITE_LOCK if !PREEMPTION 50 select ARCH_INLINE_WRITE_LOCK_BH if !PREEMPTION 51 select ARCH_INLINE_WRITE_LOCK_IRQ if !PREEMPTION 52 select ARCH_INLINE_WRITE_LOCK_IRQSAVE if !PREEMPTION 53 select ARCH_INLINE_WRITE_UNLOCK if !PREEMPTION 54 select ARCH_INLINE_WRITE_UNLOCK_BH if !PREEMPTION 55 select ARCH_INLINE_WRITE_UNLOCK_IRQ if !PREEMPTION 56 select ARCH_INLINE_WRITE_UNLOCK_IRQRESTORE if !PREEMPTION 57 select ARCH_INLINE_SPIN_TRYLOCK if !PREEMPTION 58 select ARCH_INLINE_SPIN_TRYLOCK_BH if !PREEMPTION 59 select ARCH_INLINE_SPIN_LOCK if !PREEMPTION 60 select ARCH_INLINE_SPIN_LOCK_BH if !PREEMPTION 61 select ARCH_INLINE_SPIN_LOCK_IRQ if !PREEMPTION 62 select ARCH_INLINE_SPIN_LOCK_IRQSAVE if !PREEMPTION 63 select ARCH_INLINE_SPIN_UNLOCK if !PREEMPTION 64 select ARCH_INLINE_SPIN_UNLOCK_BH if !PREEMPTION 65 select ARCH_INLINE_SPIN_UNLOCK_IRQ if !PREEMPTION 66 select ARCH_INLINE_SPIN_UNLOCK_IRQRESTORE if !PREEMPTION 67 select ARCH_KEEP_MEMBLOCK 68 select ARCH_USE_CMPXCHG_LOCKREF 69 select ARCH_USE_GNU_PROPERTY 70 select ARCH_USE_QUEUED_RWLOCKS 71 select ARCH_USE_QUEUED_SPINLOCKS 72 select ARCH_USE_SYM_ANNOTATIONS 73 select ARCH_SUPPORTS_DEBUG_PAGEALLOC 74 select ARCH_SUPPORTS_MEMORY_FAILURE 75 select ARCH_SUPPORTS_SHADOW_CALL_STACK if CC_HAVE_SHADOW_CALL_STACK 76 select ARCH_SUPPORTS_LTO_CLANG if CPU_LITTLE_ENDIAN 77 select ARCH_SUPPORTS_LTO_CLANG_THIN 78 select ARCH_SUPPORTS_ATOMIC_RMW 79 select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && (GCC_VERSION >= 50000 || CC_IS_CLANG) 80 select ARCH_SUPPORTS_NUMA_BALANCING 81 select ARCH_WANT_COMPAT_IPC_PARSE_VERSION if COMPAT 82 select ARCH_WANT_DEFAULT_BPF_JIT 83 select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT 84 select ARCH_WANT_FRAME_POINTERS 85 select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36) 86 select ARCH_WANT_LD_ORPHAN_WARN 87 select ARCH_HAS_UBSAN_SANITIZE_ALL 88 select ARM_AMBA 89 select ARM_ARCH_TIMER 90 select ARM_GIC 91 select AUDIT_ARCH_COMPAT_GENERIC 92 select ARM_GIC_V2M if PCI 93 select ARM_GIC_V3 94 select ARM_GIC_V3_ITS if PCI 95 select ARM_PSCI_FW 96 select BUILDTIME_TABLE_SORT 97 select CLONE_BACKWARDS 98 select COMMON_CLK 99 select CPU_PM if (SUSPEND || CPU_IDLE) 100 select CRC32 101 select DCACHE_WORD_ACCESS 102 select DMA_DIRECT_REMAP 103 select EDAC_SUPPORT 104 select FRAME_POINTER 105 select GENERIC_ALLOCATOR 106 select GENERIC_ARCH_TOPOLOGY 107 select GENERIC_CLOCKEVENTS_BROADCAST 108 select GENERIC_CPU_AUTOPROBE 109 select GENERIC_CPU_VULNERABILITIES 110 select GENERIC_EARLY_IOREMAP 111 select GENERIC_IDLE_POLL_SETUP 112 select GENERIC_IRQ_IPI 113 select GENERIC_IRQ_MULTI_HANDLER 114 select GENERIC_IRQ_PROBE 115 select GENERIC_IRQ_SHOW 116 select GENERIC_IRQ_SHOW_LEVEL 117 select GENERIC_LIB_DEVMEM_IS_ALLOWED 118 select GENERIC_PCI_IOMAP 119 select GENERIC_PTDUMP 120 select GENERIC_SCHED_CLOCK 121 select GENERIC_SMP_IDLE_THREAD 122 select GENERIC_STRNCPY_FROM_USER 123 select GENERIC_STRNLEN_USER 124 select GENERIC_TIME_VSYSCALL 125 select GENERIC_GETTIMEOFDAY 126 select GENERIC_VDSO_TIME_NS 127 select HANDLE_DOMAIN_IRQ 128 select HARDIRQS_SW_RESEND 129 select HAVE_MOVE_PMD 130 select HAVE_MOVE_PUD 131 select HAVE_PCI 132 select HAVE_ACPI_APEI if (ACPI && EFI) 133 select HAVE_ALIGNED_STRUCT_PAGE if SLUB 134 select HAVE_ARCH_AUDITSYSCALL 135 select HAVE_ARCH_BITREVERSE 136 select HAVE_ARCH_COMPILER_H 137 select HAVE_ARCH_HUGE_VMAP 138 select HAVE_ARCH_JUMP_LABEL 139 select HAVE_ARCH_JUMP_LABEL_RELATIVE 140 select HAVE_ARCH_KASAN if !(ARM64_16K_PAGES && ARM64_VA_BITS_48) 141 select HAVE_ARCH_KASAN_SW_TAGS if HAVE_ARCH_KASAN 142 select HAVE_ARCH_KASAN_HW_TAGS if (HAVE_ARCH_KASAN && ARM64_MTE) 143 select HAVE_ARCH_KFENCE 144 select HAVE_ARCH_KGDB 145 select HAVE_ARCH_MMAP_RND_BITS 146 select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT 147 select HAVE_ARCH_PFN_VALID 148 select HAVE_ARCH_PREL32_RELOCATIONS 149 select HAVE_ARCH_SECCOMP_FILTER 150 select HAVE_ARCH_STACKLEAK 151 select HAVE_ARCH_THREAD_STRUCT_WHITELIST 152 select HAVE_ARCH_TRACEHOOK 153 select HAVE_ARCH_TRANSPARENT_HUGEPAGE 154 select HAVE_ARCH_VMAP_STACK 155 select HAVE_ARM_SMCCC 156 select HAVE_ASM_MODVERSIONS 157 select HAVE_EBPF_JIT 158 select HAVE_C_RECORDMCOUNT 159 select HAVE_CMPXCHG_DOUBLE 160 select HAVE_CMPXCHG_LOCAL 161 select HAVE_CONTEXT_TRACKING 162 select HAVE_DEBUG_BUGVERBOSE 163 select HAVE_DEBUG_KMEMLEAK 164 select HAVE_DMA_CONTIGUOUS 165 select HAVE_DYNAMIC_FTRACE 166 select HAVE_DYNAMIC_FTRACE_WITH_REGS \ 167 if $(cc-option,-fpatchable-function-entry=2) 168 select FTRACE_MCOUNT_USE_PATCHABLE_FUNCTION_ENTRY \ 169 if DYNAMIC_FTRACE_WITH_REGS 170 select HAVE_EFFICIENT_UNALIGNED_ACCESS 171 select HAVE_FAST_GUP 172 select HAVE_FTRACE_MCOUNT_RECORD 173 select HAVE_FUNCTION_TRACER 174 select HAVE_FUNCTION_ERROR_INJECTION 175 select HAVE_FUNCTION_GRAPH_TRACER 176 select HAVE_GCC_PLUGINS 177 select HAVE_HW_BREAKPOINT if PERF_EVENTS 178 select HAVE_IRQ_TIME_ACCOUNTING 179 select HAVE_NMI 180 select HAVE_PATA_PLATFORM 181 select HAVE_PERF_EVENTS 182 select HAVE_PERF_REGS 183 select HAVE_PERF_USER_STACK_DUMP 184 select HAVE_REGS_AND_STACK_ACCESS_API 185 select HAVE_FUNCTION_ARG_ACCESS_API 186 select HAVE_FUTEX_CMPXCHG if FUTEX 187 select MMU_GATHER_RCU_TABLE_FREE 188 select HAVE_RSEQ 189 select HAVE_STACKPROTECTOR 190 select HAVE_SYSCALL_TRACEPOINTS 191 select HAVE_KPROBES 192 select HAVE_KRETPROBES 193 select HAVE_GENERIC_VDSO 194 select IOMMU_DMA if IOMMU_SUPPORT 195 select IRQ_DOMAIN 196 select IRQ_FORCED_THREADING 197 select MODULES_USE_ELF_RELA 198 select NEED_DMA_MAP_STATE 199 select NEED_SG_DMA_LENGTH 200 select OF 201 select OF_EARLY_FLATTREE 202 select PCI_DOMAINS_GENERIC if PCI 203 select PCI_ECAM if (ACPI && PCI) 204 select PCI_SYSCALL if PCI 205 select POWER_RESET 206 select POWER_SUPPLY 207 select SPARSE_IRQ 208 select SWIOTLB 209 select SYSCTL_EXCEPTION_TRACE 210 select THREAD_INFO_IN_TASK 211 help 212 ARM 64-bit (AArch64) Linux support. 213 214config 64BIT 215 def_bool y 216 217config MMU 218 def_bool y 219 220config ARM64_PAGE_SHIFT 221 int 222 default 16 if ARM64_64K_PAGES 223 default 14 if ARM64_16K_PAGES 224 default 12 225 226config ARM64_CONT_PTE_SHIFT 227 int 228 default 5 if ARM64_64K_PAGES 229 default 7 if ARM64_16K_PAGES 230 default 4 231 232config ARM64_CONT_PMD_SHIFT 233 int 234 default 5 if ARM64_64K_PAGES 235 default 5 if ARM64_16K_PAGES 236 default 4 237 238config ARCH_MMAP_RND_BITS_MIN 239 default 14 if ARM64_64K_PAGES 240 default 16 if ARM64_16K_PAGES 241 default 18 242 243# max bits determined by the following formula: 244# VA_BITS - PAGE_SHIFT - 3 245config ARCH_MMAP_RND_BITS_MAX 246 default 19 if ARM64_VA_BITS=36 247 default 24 if ARM64_VA_BITS=39 248 default 27 if ARM64_VA_BITS=42 249 default 30 if ARM64_VA_BITS=47 250 default 29 if ARM64_VA_BITS=48 && ARM64_64K_PAGES 251 default 31 if ARM64_VA_BITS=48 && ARM64_16K_PAGES 252 default 33 if ARM64_VA_BITS=48 253 default 14 if ARM64_64K_PAGES 254 default 16 if ARM64_16K_PAGES 255 default 18 256 257config ARCH_MMAP_RND_COMPAT_BITS_MIN 258 default 7 if ARM64_64K_PAGES 259 default 9 if ARM64_16K_PAGES 260 default 11 261 262config ARCH_MMAP_RND_COMPAT_BITS_MAX 263 default 16 264 265config NO_IOPORT_MAP 266 def_bool y if !PCI 267 268config STACKTRACE_SUPPORT 269 def_bool y 270 271config ILLEGAL_POINTER_VALUE 272 hex 273 default 0xdead000000000000 274 275config LOCKDEP_SUPPORT 276 def_bool y 277 278config TRACE_IRQFLAGS_SUPPORT 279 def_bool y 280 281config GENERIC_BUG 282 def_bool y 283 depends on BUG 284 285config GENERIC_BUG_RELATIVE_POINTERS 286 def_bool y 287 depends on GENERIC_BUG 288 289config GENERIC_HWEIGHT 290 def_bool y 291 292config GENERIC_CSUM 293 def_bool y 294 295config GENERIC_CALIBRATE_DELAY 296 def_bool y 297 298config ZONE_DMA 299 bool "Support DMA zone" if EXPERT 300 default y 301 302config ZONE_DMA32 303 bool "Support DMA32 zone" if EXPERT 304 default y 305 306config ARCH_ENABLE_MEMORY_HOTPLUG 307 def_bool y 308 309config ARCH_ENABLE_MEMORY_HOTREMOVE 310 def_bool y 311 312config SMP 313 def_bool y 314 315config KERNEL_MODE_NEON 316 def_bool y 317 318config FIX_EARLYCON_MEM 319 def_bool y 320 321config PGTABLE_LEVELS 322 int 323 default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 324 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 325 default 3 if ARM64_64K_PAGES && (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) 326 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 327 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 328 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 329 330config ARCH_SUPPORTS_UPROBES 331 def_bool y 332 333config ARCH_PROC_KCORE_TEXT 334 def_bool y 335 336config BROKEN_GAS_INST 337 def_bool !$(as-instr,1:\n.inst 0\n.rept . - 1b\n\nnop\n.endr\n) 338 339config KASAN_SHADOW_OFFSET 340 hex 341 depends on KASAN_GENERIC || KASAN_SW_TAGS 342 default 0xdfff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && !KASAN_SW_TAGS 343 default 0xdfffc00000000000 if ARM64_VA_BITS_47 && !KASAN_SW_TAGS 344 default 0xdffffe0000000000 if ARM64_VA_BITS_42 && !KASAN_SW_TAGS 345 default 0xdfffffc000000000 if ARM64_VA_BITS_39 && !KASAN_SW_TAGS 346 default 0xdffffff800000000 if ARM64_VA_BITS_36 && !KASAN_SW_TAGS 347 default 0xefff800000000000 if (ARM64_VA_BITS_48 || ARM64_VA_BITS_52) && KASAN_SW_TAGS 348 default 0xefffc00000000000 if ARM64_VA_BITS_47 && KASAN_SW_TAGS 349 default 0xeffffe0000000000 if ARM64_VA_BITS_42 && KASAN_SW_TAGS 350 default 0xefffffc000000000 if ARM64_VA_BITS_39 && KASAN_SW_TAGS 351 default 0xeffffff800000000 if ARM64_VA_BITS_36 && KASAN_SW_TAGS 352 default 0xffffffffffffffff 353 354source "arch/arm64/Kconfig.platforms" 355 356menu "Kernel Features" 357 358menu "ARM errata workarounds via the alternatives framework" 359 360config ARM64_WORKAROUND_CLEAN_CACHE 361 bool 362 363config ARM64_ERRATUM_826319 364 bool "Cortex-A53: 826319: System might deadlock if a write cannot complete until read data is accepted" 365 default y 366 select ARM64_WORKAROUND_CLEAN_CACHE 367 help 368 This option adds an alternative code sequence to work around ARM 369 erratum 826319 on Cortex-A53 parts up to r0p2 with an AMBA 4 ACE or 370 AXI master interface and an L2 cache. 371 372 If a Cortex-A53 uses an AMBA AXI4 ACE interface to other processors 373 and is unable to accept a certain write via this interface, it will 374 not progress on read data presented on the read data channel and the 375 system can deadlock. 376 377 The workaround promotes data cache clean instructions to 378 data cache clean-and-invalidate. 379 Please note that this does not necessarily enable the workaround, 380 as it depends on the alternative framework, which will only patch 381 the kernel if an affected CPU is detected. 382 383 If unsure, say Y. 384 385config ARM64_ERRATUM_827319 386 bool "Cortex-A53: 827319: Data cache clean instructions might cause overlapping transactions to the interconnect" 387 default y 388 select ARM64_WORKAROUND_CLEAN_CACHE 389 help 390 This option adds an alternative code sequence to work around ARM 391 erratum 827319 on Cortex-A53 parts up to r0p2 with an AMBA 5 CHI 392 master interface and an L2 cache. 393 394 Under certain conditions this erratum can cause a clean line eviction 395 to occur at the same time as another transaction to the same address 396 on the AMBA 5 CHI interface, which can cause data corruption if the 397 interconnect reorders the two transactions. 398 399 The workaround promotes data cache clean instructions to 400 data cache clean-and-invalidate. 401 Please note that this does not necessarily enable the workaround, 402 as it depends on the alternative framework, which will only patch 403 the kernel if an affected CPU is detected. 404 405 If unsure, say Y. 406 407config ARM64_ERRATUM_824069 408 bool "Cortex-A53: 824069: Cache line might not be marked as clean after a CleanShared snoop" 409 default y 410 select ARM64_WORKAROUND_CLEAN_CACHE 411 help 412 This option adds an alternative code sequence to work around ARM 413 erratum 824069 on Cortex-A53 parts up to r0p2 when it is connected 414 to a coherent interconnect. 415 416 If a Cortex-A53 processor is executing a store or prefetch for 417 write instruction at the same time as a processor in another 418 cluster is executing a cache maintenance operation to the same 419 address, then this erratum might cause a clean cache line to be 420 incorrectly marked as dirty. 421 422 The workaround promotes data cache clean instructions to 423 data cache clean-and-invalidate. 424 Please note that this option does not necessarily enable the 425 workaround, as it depends on the alternative framework, which will 426 only patch the kernel if an affected CPU is detected. 427 428 If unsure, say Y. 429 430config ARM64_ERRATUM_819472 431 bool "Cortex-A53: 819472: Store exclusive instructions might cause data corruption" 432 default y 433 select ARM64_WORKAROUND_CLEAN_CACHE 434 help 435 This option adds an alternative code sequence to work around ARM 436 erratum 819472 on Cortex-A53 parts up to r0p1 with an L2 cache 437 present when it is connected to a coherent interconnect. 438 439 If the processor is executing a load and store exclusive sequence at 440 the same time as a processor in another cluster is executing a cache 441 maintenance operation to the same address, then this erratum might 442 cause data corruption. 443 444 The workaround promotes data cache clean instructions to 445 data cache clean-and-invalidate. 446 Please note that this does not necessarily enable the workaround, 447 as it depends on the alternative framework, which will only patch 448 the kernel if an affected CPU is detected. 449 450 If unsure, say Y. 451 452config ARM64_ERRATUM_832075 453 bool "Cortex-A57: 832075: possible deadlock on mixing exclusive memory accesses with device loads" 454 default y 455 help 456 This option adds an alternative code sequence to work around ARM 457 erratum 832075 on Cortex-A57 parts up to r1p2. 458 459 Affected Cortex-A57 parts might deadlock when exclusive load/store 460 instructions to Write-Back memory are mixed with Device loads. 461 462 The workaround is to promote device loads to use Load-Acquire 463 semantics. 464 Please note that this does not necessarily enable the workaround, 465 as it depends on the alternative framework, which will only patch 466 the kernel if an affected CPU is detected. 467 468 If unsure, say Y. 469 470config ARM64_ERRATUM_834220 471 bool "Cortex-A57: 834220: Stage 2 translation fault might be incorrectly reported in presence of a Stage 1 fault" 472 depends on KVM 473 default y 474 help 475 This option adds an alternative code sequence to work around ARM 476 erratum 834220 on Cortex-A57 parts up to r1p2. 477 478 Affected Cortex-A57 parts might report a Stage 2 translation 479 fault as the result of a Stage 1 fault for load crossing a 480 page boundary when there is a permission or device memory 481 alignment fault at Stage 1 and a translation fault at Stage 2. 482 483 The workaround is to verify that the Stage 1 translation 484 doesn't generate a fault before handling the Stage 2 fault. 485 Please note that this does not necessarily enable the workaround, 486 as it depends on the alternative framework, which will only patch 487 the kernel if an affected CPU is detected. 488 489 If unsure, say Y. 490 491config ARM64_ERRATUM_845719 492 bool "Cortex-A53: 845719: a load might read incorrect data" 493 depends on COMPAT 494 default y 495 help 496 This option adds an alternative code sequence to work around ARM 497 erratum 845719 on Cortex-A53 parts up to r0p4. 498 499 When running a compat (AArch32) userspace on an affected Cortex-A53 500 part, a load at EL0 from a virtual address that matches the bottom 32 501 bits of the virtual address used by a recent load at (AArch64) EL1 502 might return incorrect data. 503 504 The workaround is to write the contextidr_el1 register on exception 505 return to a 32-bit task. 506 Please note that this does not necessarily enable the workaround, 507 as it depends on the alternative framework, which will only patch 508 the kernel if an affected CPU is detected. 509 510 If unsure, say Y. 511 512config ARM64_ERRATUM_843419 513 bool "Cortex-A53: 843419: A load or store might access an incorrect address" 514 default y 515 select ARM64_MODULE_PLTS if MODULES 516 help 517 This option links the kernel with '--fix-cortex-a53-843419' and 518 enables PLT support to replace certain ADRP instructions, which can 519 cause subsequent memory accesses to use an incorrect address on 520 Cortex-A53 parts up to r0p4. 521 522 If unsure, say Y. 523 524config ARM64_ERRATUM_1024718 525 bool "Cortex-A55: 1024718: Update of DBM/AP bits without break before make might result in incorrect update" 526 default y 527 help 528 This option adds a workaround for ARM Cortex-A55 Erratum 1024718. 529 530 Affected Cortex-A55 cores (all revisions) could cause incorrect 531 update of the hardware dirty bit when the DBM/AP bits are updated 532 without a break-before-make. The workaround is to disable the usage 533 of hardware DBM locally on the affected cores. CPUs not affected by 534 this erratum will continue to use the feature. 535 536 If unsure, say Y. 537 538config ARM64_ERRATUM_1418040 539 bool "Cortex-A76/Neoverse-N1: MRC read following MRRC read of specific Generic Timer in AArch32 might give incorrect result" 540 default y 541 depends on COMPAT 542 help 543 This option adds a workaround for ARM Cortex-A76/Neoverse-N1 544 errata 1188873 and 1418040. 545 546 Affected Cortex-A76/Neoverse-N1 cores (r0p0 to r3p1) could 547 cause register corruption when accessing the timer registers 548 from AArch32 userspace. 549 550 If unsure, say Y. 551 552config ARM64_WORKAROUND_SPECULATIVE_AT 553 bool 554 555config ARM64_ERRATUM_1165522 556 bool "Cortex-A76: 1165522: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 557 default y 558 select ARM64_WORKAROUND_SPECULATIVE_AT 559 help 560 This option adds a workaround for ARM Cortex-A76 erratum 1165522. 561 562 Affected Cortex-A76 cores (r0p0, r1p0, r2p0) could end-up with 563 corrupted TLBs by speculating an AT instruction during a guest 564 context switch. 565 566 If unsure, say Y. 567 568config ARM64_ERRATUM_1319367 569 bool "Cortex-A57/A72: 1319537: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 570 default y 571 select ARM64_WORKAROUND_SPECULATIVE_AT 572 help 573 This option adds work arounds for ARM Cortex-A57 erratum 1319537 574 and A72 erratum 1319367 575 576 Cortex-A57 and A72 cores could end-up with corrupted TLBs by 577 speculating an AT instruction during a guest context switch. 578 579 If unsure, say Y. 580 581config ARM64_ERRATUM_1530923 582 bool "Cortex-A55: 1530923: Speculative AT instruction using out-of-context translation regime could cause subsequent request to generate an incorrect translation" 583 default y 584 select ARM64_WORKAROUND_SPECULATIVE_AT 585 help 586 This option adds a workaround for ARM Cortex-A55 erratum 1530923. 587 588 Affected Cortex-A55 cores (r0p0, r0p1, r1p0, r2p0) could end-up with 589 corrupted TLBs by speculating an AT instruction during a guest 590 context switch. 591 592 If unsure, say Y. 593 594config ARM64_WORKAROUND_REPEAT_TLBI 595 bool 596 597config ARM64_ERRATUM_1286807 598 bool "Cortex-A76: Modification of the translation table for a virtual address might lead to read-after-read ordering violation" 599 default y 600 select ARM64_WORKAROUND_REPEAT_TLBI 601 help 602 This option adds a workaround for ARM Cortex-A76 erratum 1286807. 603 604 On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual 605 address for a cacheable mapping of a location is being 606 accessed by a core while another core is remapping the virtual 607 address to a new physical page using the recommended 608 break-before-make sequence, then under very rare circumstances 609 TLBI+DSB completes before a read using the translation being 610 invalidated has been observed by other observers. The 611 workaround repeats the TLBI+DSB operation. 612 613config ARM64_ERRATUM_1463225 614 bool "Cortex-A76: Software Step might prevent interrupt recognition" 615 default y 616 help 617 This option adds a workaround for Arm Cortex-A76 erratum 1463225. 618 619 On the affected Cortex-A76 cores (r0p0 to r3p1), software stepping 620 of a system call instruction (SVC) can prevent recognition of 621 subsequent interrupts when software stepping is disabled in the 622 exception handler of the system call and either kernel debugging 623 is enabled or VHE is in use. 624 625 Work around the erratum by triggering a dummy step exception 626 when handling a system call from a task that is being stepped 627 in a VHE configuration of the kernel. 628 629 If unsure, say Y. 630 631config ARM64_ERRATUM_1542419 632 bool "Neoverse-N1: workaround mis-ordering of instruction fetches" 633 default y 634 help 635 This option adds a workaround for ARM Neoverse-N1 erratum 636 1542419. 637 638 Affected Neoverse-N1 cores could execute a stale instruction when 639 modified by another CPU. The workaround depends on a firmware 640 counterpart. 641 642 Workaround the issue by hiding the DIC feature from EL0. This 643 forces user-space to perform cache maintenance. 644 645 If unsure, say Y. 646 647config ARM64_ERRATUM_1508412 648 bool "Cortex-A77: 1508412: workaround deadlock on sequence of NC/Device load and store exclusive or PAR read" 649 default y 650 help 651 This option adds a workaround for Arm Cortex-A77 erratum 1508412. 652 653 Affected Cortex-A77 cores (r0p0, r1p0) could deadlock on a sequence 654 of a store-exclusive or read of PAR_EL1 and a load with device or 655 non-cacheable memory attributes. The workaround depends on a firmware 656 counterpart. 657 658 KVM guests must also have the workaround implemented or they can 659 deadlock the system. 660 661 Work around the issue by inserting DMB SY barriers around PAR_EL1 662 register reads and warning KVM users. The DMB barrier is sufficient 663 to prevent a speculative PAR_EL1 read. 664 665 If unsure, say Y. 666 667config CAVIUM_ERRATUM_22375 668 bool "Cavium erratum 22375, 24313" 669 default y 670 help 671 Enable workaround for errata 22375 and 24313. 672 673 This implements two gicv3-its errata workarounds for ThunderX. Both 674 with a small impact affecting only ITS table allocation. 675 676 erratum 22375: only alloc 8MB table size 677 erratum 24313: ignore memory access type 678 679 The fixes are in ITS initialization and basically ignore memory access 680 type and table size provided by the TYPER and BASER registers. 681 682 If unsure, say Y. 683 684config CAVIUM_ERRATUM_23144 685 bool "Cavium erratum 23144: ITS SYNC hang on dual socket system" 686 depends on NUMA 687 default y 688 help 689 ITS SYNC command hang for cross node io and collections/cpu mapping. 690 691 If unsure, say Y. 692 693config CAVIUM_ERRATUM_23154 694 bool "Cavium erratum 23154: Access to ICC_IAR1_EL1 is not sync'ed" 695 default y 696 help 697 The gicv3 of ThunderX requires a modified version for 698 reading the IAR status to ensure data synchronization 699 (access to icc_iar1_el1 is not sync'ed before and after). 700 701 If unsure, say Y. 702 703config CAVIUM_ERRATUM_27456 704 bool "Cavium erratum 27456: Broadcast TLBI instructions may cause icache corruption" 705 default y 706 help 707 On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI 708 instructions may cause the icache to become corrupted if it 709 contains data for a non-current ASID. The fix is to 710 invalidate the icache when changing the mm context. 711 712 If unsure, say Y. 713 714config CAVIUM_ERRATUM_30115 715 bool "Cavium erratum 30115: Guest may disable interrupts in host" 716 default y 717 help 718 On ThunderX T88 pass 1.x through 2.2, T81 pass 1.0 through 719 1.2, and T83 Pass 1.0, KVM guest execution may disable 720 interrupts in host. Trapping both GICv3 group-0 and group-1 721 accesses sidesteps the issue. 722 723 If unsure, say Y. 724 725config CAVIUM_TX2_ERRATUM_219 726 bool "Cavium ThunderX2 erratum 219: PRFM between TTBR change and ISB fails" 727 default y 728 help 729 On Cavium ThunderX2, a load, store or prefetch instruction between a 730 TTBR update and the corresponding context synchronizing operation can 731 cause a spurious Data Abort to be delivered to any hardware thread in 732 the CPU core. 733 734 Work around the issue by avoiding the problematic code sequence and 735 trapping KVM guest TTBRx_EL1 writes to EL2 when SMT is enabled. The 736 trap handler performs the corresponding register access, skips the 737 instruction and ensures context synchronization by virtue of the 738 exception return. 739 740 If unsure, say Y. 741 742config FUJITSU_ERRATUM_010001 743 bool "Fujitsu-A64FX erratum E#010001: Undefined fault may occur wrongly" 744 default y 745 help 746 This option adds a workaround for Fujitsu-A64FX erratum E#010001. 747 On some variants of the Fujitsu-A64FX cores ver(1.0, 1.1), memory 748 accesses may cause undefined fault (Data abort, DFSC=0b111111). 749 This fault occurs under a specific hardware condition when a 750 load/store instruction performs an address translation using: 751 case-1 TTBR0_EL1 with TCR_EL1.NFD0 == 1. 752 case-2 TTBR0_EL2 with TCR_EL2.NFD0 == 1. 753 case-3 TTBR1_EL1 with TCR_EL1.NFD1 == 1. 754 case-4 TTBR1_EL2 with TCR_EL2.NFD1 == 1. 755 756 The workaround is to ensure these bits are clear in TCR_ELx. 757 The workaround only affects the Fujitsu-A64FX. 758 759 If unsure, say Y. 760 761config HISILICON_ERRATUM_161600802 762 bool "Hip07 161600802: Erroneous redistributor VLPI base" 763 default y 764 help 765 The HiSilicon Hip07 SoC uses the wrong redistributor base 766 when issued ITS commands such as VMOVP and VMAPP, and requires 767 a 128kB offset to be applied to the target address in this commands. 768 769 If unsure, say Y. 770 771config QCOM_FALKOR_ERRATUM_1003 772 bool "Falkor E1003: Incorrect translation due to ASID change" 773 default y 774 help 775 On Falkor v1, an incorrect ASID may be cached in the TLB when ASID 776 and BADDR are changed together in TTBRx_EL1. Since we keep the ASID 777 in TTBR1_EL1, this situation only occurs in the entry trampoline and 778 then only for entries in the walk cache, since the leaf translation 779 is unchanged. Work around the erratum by invalidating the walk cache 780 entries for the trampoline before entering the kernel proper. 781 782config QCOM_FALKOR_ERRATUM_1009 783 bool "Falkor E1009: Prematurely complete a DSB after a TLBI" 784 default y 785 select ARM64_WORKAROUND_REPEAT_TLBI 786 help 787 On Falkor v1, the CPU may prematurely complete a DSB following a 788 TLBI xxIS invalidate maintenance operation. Repeat the TLBI operation 789 one more time to fix the issue. 790 791 If unsure, say Y. 792 793config QCOM_QDF2400_ERRATUM_0065 794 bool "QDF2400 E0065: Incorrect GITS_TYPER.ITT_Entry_size" 795 default y 796 help 797 On Qualcomm Datacenter Technologies QDF2400 SoC, ITS hardware reports 798 ITE size incorrectly. The GITS_TYPER.ITT_Entry_size field should have 799 been indicated as 16Bytes (0xf), not 8Bytes (0x7). 800 801 If unsure, say Y. 802 803config QCOM_FALKOR_ERRATUM_E1041 804 bool "Falkor E1041: Speculative instruction fetches might cause errant memory access" 805 default y 806 help 807 Falkor CPU may speculatively fetch instructions from an improper 808 memory location when MMU translation is changed from SCTLR_ELn[M]=1 809 to SCTLR_ELn[M]=0. Prefix an ISB instruction to fix the problem. 810 811 If unsure, say Y. 812 813config SOCIONEXT_SYNQUACER_PREITS 814 bool "Socionext Synquacer: Workaround for GICv3 pre-ITS" 815 default y 816 help 817 Socionext Synquacer SoCs implement a separate h/w block to generate 818 MSI doorbell writes with non-zero values for the device ID. 819 820 If unsure, say Y. 821 822endmenu 823 824 825choice 826 prompt "Page size" 827 default ARM64_4K_PAGES 828 help 829 Page size (translation granule) configuration. 830 831config ARM64_4K_PAGES 832 bool "4KB" 833 help 834 This feature enables 4KB pages support. 835 836config ARM64_16K_PAGES 837 bool "16KB" 838 help 839 The system will use 16KB pages support. AArch32 emulation 840 requires applications compiled with 16K (or a multiple of 16K) 841 aligned segments. 842 843config ARM64_64K_PAGES 844 bool "64KB" 845 help 846 This feature enables 64KB pages support (4KB by default) 847 allowing only two levels of page tables and faster TLB 848 look-up. AArch32 emulation requires applications compiled 849 with 64K aligned segments. 850 851endchoice 852 853choice 854 prompt "Virtual address space size" 855 default ARM64_VA_BITS_39 if ARM64_4K_PAGES 856 default ARM64_VA_BITS_47 if ARM64_16K_PAGES 857 default ARM64_VA_BITS_42 if ARM64_64K_PAGES 858 help 859 Allows choosing one of multiple possible virtual address 860 space sizes. The level of translation table is determined by 861 a combination of page size and virtual address space size. 862 863config ARM64_VA_BITS_36 864 bool "36-bit" if EXPERT 865 depends on ARM64_16K_PAGES 866 867config ARM64_VA_BITS_39 868 bool "39-bit" 869 depends on ARM64_4K_PAGES 870 871config ARM64_VA_BITS_42 872 bool "42-bit" 873 depends on ARM64_64K_PAGES 874 875config ARM64_VA_BITS_47 876 bool "47-bit" 877 depends on ARM64_16K_PAGES 878 879config ARM64_VA_BITS_48 880 bool "48-bit" 881 882config ARM64_VA_BITS_52 883 bool "52-bit" 884 depends on ARM64_64K_PAGES && (ARM64_PAN || !ARM64_SW_TTBR0_PAN) 885 help 886 Enable 52-bit virtual addressing for userspace when explicitly 887 requested via a hint to mmap(). The kernel will also use 52-bit 888 virtual addresses for its own mappings (provided HW support for 889 this feature is available, otherwise it reverts to 48-bit). 890 891 NOTE: Enabling 52-bit virtual addressing in conjunction with 892 ARMv8.3 Pointer Authentication will result in the PAC being 893 reduced from 7 bits to 3 bits, which may have a significant 894 impact on its susceptibility to brute-force attacks. 895 896 If unsure, select 48-bit virtual addressing instead. 897 898endchoice 899 900config ARM64_FORCE_52BIT 901 bool "Force 52-bit virtual addresses for userspace" 902 depends on ARM64_VA_BITS_52 && EXPERT 903 help 904 For systems with 52-bit userspace VAs enabled, the kernel will attempt 905 to maintain compatibility with older software by providing 48-bit VAs 906 unless a hint is supplied to mmap. 907 908 This configuration option disables the 48-bit compatibility logic, and 909 forces all userspace addresses to be 52-bit on HW that supports it. One 910 should only enable this configuration option for stress testing userspace 911 memory management code. If unsure say N here. 912 913config ARM64_VA_BITS 914 int 915 default 36 if ARM64_VA_BITS_36 916 default 39 if ARM64_VA_BITS_39 917 default 42 if ARM64_VA_BITS_42 918 default 47 if ARM64_VA_BITS_47 919 default 48 if ARM64_VA_BITS_48 920 default 52 if ARM64_VA_BITS_52 921 922choice 923 prompt "Physical address space size" 924 default ARM64_PA_BITS_48 925 help 926 Choose the maximum physical address range that the kernel will 927 support. 928 929config ARM64_PA_BITS_48 930 bool "48-bit" 931 932config ARM64_PA_BITS_52 933 bool "52-bit (ARMv8.2)" 934 depends on ARM64_64K_PAGES 935 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 936 help 937 Enable support for a 52-bit physical address space, introduced as 938 part of the ARMv8.2-LPA extension. 939 940 With this enabled, the kernel will also continue to work on CPUs that 941 do not support ARMv8.2-LPA, but with some added memory overhead (and 942 minor performance overhead). 943 944endchoice 945 946config ARM64_PA_BITS 947 int 948 default 48 if ARM64_PA_BITS_48 949 default 52 if ARM64_PA_BITS_52 950 951choice 952 prompt "Endianness" 953 default CPU_LITTLE_ENDIAN 954 help 955 Select the endianness of data accesses performed by the CPU. Userspace 956 applications will need to be compiled and linked for the endianness 957 that is selected here. 958 959config CPU_BIG_ENDIAN 960 bool "Build big-endian kernel" 961 depends on !LD_IS_LLD || LLD_VERSION >= 130000 962 help 963 Say Y if you plan on running a kernel with a big-endian userspace. 964 965config CPU_LITTLE_ENDIAN 966 bool "Build little-endian kernel" 967 help 968 Say Y if you plan on running a kernel with a little-endian userspace. 969 This is usually the case for distributions targeting arm64. 970 971endchoice 972 973config SCHED_MC 974 bool "Multi-core scheduler support" 975 help 976 Multi-core scheduler support improves the CPU scheduler's decision 977 making when dealing with multi-core CPU chips at a cost of slightly 978 increased overhead in some places. If unsure say N here. 979 980config SCHED_SMT 981 bool "SMT scheduler support" 982 help 983 Improves the CPU scheduler's decision making when dealing with 984 MultiThreading at a cost of slightly increased overhead in some 985 places. If unsure say N here. 986 987config NR_CPUS 988 int "Maximum number of CPUs (2-4096)" 989 range 2 4096 990 default "256" 991 992config HOTPLUG_CPU 993 bool "Support for hot-pluggable CPUs" 994 select GENERIC_IRQ_MIGRATION 995 help 996 Say Y here to experiment with turning CPUs off and on. CPUs 997 can be controlled through /sys/devices/system/cpu. 998 999# Common NUMA Features 1000config NUMA 1001 bool "NUMA Memory Allocation and Scheduler Support" 1002 select GENERIC_ARCH_NUMA 1003 select ACPI_NUMA if ACPI 1004 select OF_NUMA 1005 help 1006 Enable NUMA (Non-Uniform Memory Access) support. 1007 1008 The kernel will try to allocate memory used by a CPU on the 1009 local memory of the CPU and add some more 1010 NUMA awareness to the kernel. 1011 1012config NODES_SHIFT 1013 int "Maximum NUMA Nodes (as a power of 2)" 1014 range 1 10 1015 default "4" 1016 depends on NEED_MULTIPLE_NODES 1017 help 1018 Specify the maximum number of NUMA Nodes available on the target 1019 system. Increases memory reserved to accommodate various tables. 1020 1021config USE_PERCPU_NUMA_NODE_ID 1022 def_bool y 1023 depends on NUMA 1024 1025config HAVE_SETUP_PER_CPU_AREA 1026 def_bool y 1027 depends on NUMA 1028 1029config NEED_PER_CPU_EMBED_FIRST_CHUNK 1030 def_bool y 1031 depends on NUMA 1032 1033config HOLES_IN_ZONE 1034 def_bool y 1035 1036source "kernel/Kconfig.hz" 1037 1038config ARCH_SPARSEMEM_ENABLE 1039 def_bool y 1040 select SPARSEMEM_VMEMMAP_ENABLE 1041 1042config ARCH_SPARSEMEM_DEFAULT 1043 def_bool ARCH_SPARSEMEM_ENABLE 1044 1045config ARCH_SELECT_MEMORY_MODEL 1046 def_bool ARCH_SPARSEMEM_ENABLE 1047 1048config ARCH_FLATMEM_ENABLE 1049 def_bool !NUMA 1050 1051config HW_PERF_EVENTS 1052 def_bool y 1053 depends on ARM_PMU 1054 1055config SYS_SUPPORTS_HUGETLBFS 1056 def_bool y 1057 1058config ARCH_HAS_CACHE_LINE_SIZE 1059 def_bool y 1060 1061config ARCH_ENABLE_SPLIT_PMD_PTLOCK 1062 def_bool y if PGTABLE_LEVELS > 2 1063 1064# Supported by clang >= 7.0 1065config CC_HAVE_SHADOW_CALL_STACK 1066 def_bool $(cc-option, -fsanitize=shadow-call-stack -ffixed-x18) 1067 1068config PARAVIRT 1069 bool "Enable paravirtualization code" 1070 help 1071 This changes the kernel so it can modify itself when it is run 1072 under a hypervisor, potentially improving performance significantly 1073 over full virtualization. 1074 1075config PARAVIRT_TIME_ACCOUNTING 1076 bool "Paravirtual steal time accounting" 1077 select PARAVIRT 1078 help 1079 Select this option to enable fine granularity task steal time 1080 accounting. Time spent executing other tasks in parallel with 1081 the current vCPU is discounted from the vCPU power. To account for 1082 that, there can be a small performance impact. 1083 1084 If in doubt, say N here. 1085 1086config KEXEC 1087 depends on PM_SLEEP_SMP 1088 select KEXEC_CORE 1089 bool "kexec system call" 1090 help 1091 kexec is a system call that implements the ability to shutdown your 1092 current kernel, and to start another kernel. It is like a reboot 1093 but it is independent of the system firmware. And like a reboot 1094 you can start any kernel with it, not just Linux. 1095 1096config KEXEC_FILE 1097 bool "kexec file based system call" 1098 select KEXEC_CORE 1099 help 1100 This is new version of kexec system call. This system call is 1101 file based and takes file descriptors as system call argument 1102 for kernel and initramfs as opposed to list of segments as 1103 accepted by previous system call. 1104 1105config KEXEC_SIG 1106 bool "Verify kernel signature during kexec_file_load() syscall" 1107 depends on KEXEC_FILE 1108 help 1109 Select this option to verify a signature with loaded kernel 1110 image. If configured, any attempt of loading a image without 1111 valid signature will fail. 1112 1113 In addition to that option, you need to enable signature 1114 verification for the corresponding kernel image type being 1115 loaded in order for this to work. 1116 1117config KEXEC_IMAGE_VERIFY_SIG 1118 bool "Enable Image signature verification support" 1119 default y 1120 depends on KEXEC_SIG 1121 depends on EFI && SIGNED_PE_FILE_VERIFICATION 1122 help 1123 Enable Image signature verification support. 1124 1125comment "Support for PE file signature verification disabled" 1126 depends on KEXEC_SIG 1127 depends on !EFI || !SIGNED_PE_FILE_VERIFICATION 1128 1129config CRASH_DUMP 1130 bool "Build kdump crash kernel" 1131 help 1132 Generate crash dump after being started by kexec. This should 1133 be normally only set in special crash dump kernels which are 1134 loaded in the main kernel with kexec-tools into a specially 1135 reserved region and then later executed after a crash by 1136 kdump/kexec. 1137 1138 For more details see Documentation/admin-guide/kdump/kdump.rst 1139 1140config TRANS_TABLE 1141 def_bool y 1142 depends on HIBERNATION 1143 1144config XEN_DOM0 1145 def_bool y 1146 depends on XEN 1147 1148config XEN 1149 bool "Xen guest support on ARM64" 1150 depends on ARM64 && OF 1151 select SWIOTLB_XEN 1152 select PARAVIRT 1153 help 1154 Say Y if you want to run Linux in a Virtual Machine on Xen on ARM64. 1155 1156config FORCE_MAX_ZONEORDER 1157 int 1158 default "14" if ARM64_64K_PAGES 1159 default "12" if ARM64_16K_PAGES 1160 default "11" 1161 help 1162 The kernel memory allocator divides physically contiguous memory 1163 blocks into "zones", where each zone is a power of two number of 1164 pages. This option selects the largest power of two that the kernel 1165 keeps in the memory allocator. If you need to allocate very large 1166 blocks of physically contiguous memory, then you may need to 1167 increase this value. 1168 1169 This config option is actually maximum order plus one. For example, 1170 a value of 11 means that the largest free memory block is 2^10 pages. 1171 1172 We make sure that we can allocate upto a HugePage size for each configuration. 1173 Hence we have : 1174 MAX_ORDER = (PMD_SHIFT - PAGE_SHIFT) + 1 => PAGE_SHIFT - 2 1175 1176 However for 4K, we choose a higher default value, 11 as opposed to 10, giving us 1177 4M allocations matching the default size used by generic code. 1178 1179config UNMAP_KERNEL_AT_EL0 1180 bool "Unmap kernel when running in userspace (aka \"KAISER\")" if EXPERT 1181 default y 1182 help 1183 Speculation attacks against some high-performance processors can 1184 be used to bypass MMU permission checks and leak kernel data to 1185 userspace. This can be defended against by unmapping the kernel 1186 when running in userspace, mapping it back in on exception entry 1187 via a trampoline page in the vector table. 1188 1189 If unsure, say Y. 1190 1191config RODATA_FULL_DEFAULT_ENABLED 1192 bool "Apply r/o permissions of VM areas also to their linear aliases" 1193 default y 1194 help 1195 Apply read-only attributes of VM areas to the linear alias of 1196 the backing pages as well. This prevents code or read-only data 1197 from being modified (inadvertently or intentionally) via another 1198 mapping of the same memory page. This additional enhancement can 1199 be turned off at runtime by passing rodata=[off|on] (and turned on 1200 with rodata=full if this option is set to 'n') 1201 1202 This requires the linear region to be mapped down to pages, 1203 which may adversely affect performance in some cases. 1204 1205config ARM64_SW_TTBR0_PAN 1206 bool "Emulate Privileged Access Never using TTBR0_EL1 switching" 1207 help 1208 Enabling this option prevents the kernel from accessing 1209 user-space memory directly by pointing TTBR0_EL1 to a reserved 1210 zeroed area and reserved ASID. The user access routines 1211 restore the valid TTBR0_EL1 temporarily. 1212 1213config ARM64_TAGGED_ADDR_ABI 1214 bool "Enable the tagged user addresses syscall ABI" 1215 default y 1216 help 1217 When this option is enabled, user applications can opt in to a 1218 relaxed ABI via prctl() allowing tagged addresses to be passed 1219 to system calls as pointer arguments. For details, see 1220 Documentation/arm64/tagged-address-abi.rst. 1221 1222menuconfig COMPAT 1223 bool "Kernel support for 32-bit EL0" 1224 depends on ARM64_4K_PAGES || EXPERT 1225 select HAVE_UID16 1226 select OLD_SIGSUSPEND3 1227 select COMPAT_OLD_SIGACTION 1228 help 1229 This option enables support for a 32-bit EL0 running under a 64-bit 1230 kernel at EL1. AArch32-specific components such as system calls, 1231 the user helper functions, VFP support and the ptrace interface are 1232 handled appropriately by the kernel. 1233 1234 If you use a page size other than 4KB (i.e, 16KB or 64KB), please be aware 1235 that you will only be able to execute AArch32 binaries that were compiled 1236 with page size aligned segments. 1237 1238 If you want to execute 32-bit userspace applications, say Y. 1239 1240if COMPAT 1241 1242config KUSER_HELPERS 1243 bool "Enable kuser helpers page for 32-bit applications" 1244 default y 1245 help 1246 Warning: disabling this option may break 32-bit user programs. 1247 1248 Provide kuser helpers to compat tasks. The kernel provides 1249 helper code to userspace in read only form at a fixed location 1250 to allow userspace to be independent of the CPU type fitted to 1251 the system. This permits binaries to be run on ARMv4 through 1252 to ARMv8 without modification. 1253 1254 See Documentation/arm/kernel_user_helpers.rst for details. 1255 1256 However, the fixed address nature of these helpers can be used 1257 by ROP (return orientated programming) authors when creating 1258 exploits. 1259 1260 If all of the binaries and libraries which run on your platform 1261 are built specifically for your platform, and make no use of 1262 these helpers, then you can turn this option off to hinder 1263 such exploits. However, in that case, if a binary or library 1264 relying on those helpers is run, it will not function correctly. 1265 1266 Say N here only if you are absolutely certain that you do not 1267 need these helpers; otherwise, the safe option is to say Y. 1268 1269config COMPAT_VDSO 1270 bool "Enable vDSO for 32-bit applications" 1271 depends on !CPU_BIG_ENDIAN && "$(CROSS_COMPILE_COMPAT)" != "" 1272 select GENERIC_COMPAT_VDSO 1273 default y 1274 help 1275 Place in the process address space of 32-bit applications an 1276 ELF shared object providing fast implementations of gettimeofday 1277 and clock_gettime. 1278 1279 You must have a 32-bit build of glibc 2.22 or later for programs 1280 to seamlessly take advantage of this. 1281 1282config THUMB2_COMPAT_VDSO 1283 bool "Compile the 32-bit vDSO for Thumb-2 mode" if EXPERT 1284 depends on COMPAT_VDSO 1285 default y 1286 help 1287 Compile the compat vDSO with '-mthumb -fomit-frame-pointer' if y, 1288 otherwise with '-marm'. 1289 1290menuconfig ARMV8_DEPRECATED 1291 bool "Emulate deprecated/obsolete ARMv8 instructions" 1292 depends on SYSCTL 1293 help 1294 Legacy software support may require certain instructions 1295 that have been deprecated or obsoleted in the architecture. 1296 1297 Enable this config to enable selective emulation of these 1298 features. 1299 1300 If unsure, say Y 1301 1302if ARMV8_DEPRECATED 1303 1304config SWP_EMULATION 1305 bool "Emulate SWP/SWPB instructions" 1306 help 1307 ARMv8 obsoletes the use of A32 SWP/SWPB instructions such that 1308 they are always undefined. Say Y here to enable software 1309 emulation of these instructions for userspace using LDXR/STXR. 1310 This feature can be controlled at runtime with the abi.swp 1311 sysctl which is disabled by default. 1312 1313 In some older versions of glibc [<=2.8] SWP is used during futex 1314 trylock() operations with the assumption that the code will not 1315 be preempted. This invalid assumption may be more likely to fail 1316 with SWP emulation enabled, leading to deadlock of the user 1317 application. 1318 1319 NOTE: when accessing uncached shared regions, LDXR/STXR rely 1320 on an external transaction monitoring block called a global 1321 monitor to maintain update atomicity. If your system does not 1322 implement a global monitor, this option can cause programs that 1323 perform SWP operations to uncached memory to deadlock. 1324 1325 If unsure, say Y 1326 1327config CP15_BARRIER_EMULATION 1328 bool "Emulate CP15 Barrier instructions" 1329 help 1330 The CP15 barrier instructions - CP15ISB, CP15DSB, and 1331 CP15DMB - are deprecated in ARMv8 (and ARMv7). It is 1332 strongly recommended to use the ISB, DSB, and DMB 1333 instructions instead. 1334 1335 Say Y here to enable software emulation of these 1336 instructions for AArch32 userspace code. When this option is 1337 enabled, CP15 barrier usage is traced which can help 1338 identify software that needs updating. This feature can be 1339 controlled at runtime with the abi.cp15_barrier sysctl. 1340 1341 If unsure, say Y 1342 1343config SETEND_EMULATION 1344 bool "Emulate SETEND instruction" 1345 help 1346 The SETEND instruction alters the data-endianness of the 1347 AArch32 EL0, and is deprecated in ARMv8. 1348 1349 Say Y here to enable software emulation of the instruction 1350 for AArch32 userspace code. This feature can be controlled 1351 at runtime with the abi.setend sysctl. 1352 1353 Note: All the cpus on the system must have mixed endian support at EL0 1354 for this feature to be enabled. If a new CPU - which doesn't support mixed 1355 endian - is hotplugged in after this feature has been enabled, there could 1356 be unexpected results in the applications. 1357 1358 If unsure, say Y 1359endif 1360 1361endif 1362 1363menu "ARMv8.1 architectural features" 1364 1365config ARM64_HW_AFDBM 1366 bool "Support for hardware updates of the Access and Dirty page flags" 1367 default y 1368 help 1369 The ARMv8.1 architecture extensions introduce support for 1370 hardware updates of the access and dirty information in page 1371 table entries. When enabled in TCR_EL1 (HA and HD bits) on 1372 capable processors, accesses to pages with PTE_AF cleared will 1373 set this bit instead of raising an access flag fault. 1374 Similarly, writes to read-only pages with the DBM bit set will 1375 clear the read-only bit (AP[2]) instead of raising a 1376 permission fault. 1377 1378 Kernels built with this configuration option enabled continue 1379 to work on pre-ARMv8.1 hardware and the performance impact is 1380 minimal. If unsure, say Y. 1381 1382config ARM64_PAN 1383 bool "Enable support for Privileged Access Never (PAN)" 1384 default y 1385 help 1386 Privileged Access Never (PAN; part of the ARMv8.1 Extensions) 1387 prevents the kernel or hypervisor from accessing user-space (EL0) 1388 memory directly. 1389 1390 Choosing this option will cause any unprotected (not using 1391 copy_to_user et al) memory access to fail with a permission fault. 1392 1393 The feature is detected at runtime, and will remain as a 'nop' 1394 instruction if the cpu does not implement the feature. 1395 1396config AS_HAS_LDAPR 1397 def_bool $(as-instr,.arch_extension rcpc) 1398 1399config ARM64_LSE_ATOMICS 1400 bool 1401 default ARM64_USE_LSE_ATOMICS 1402 depends on $(as-instr,.arch_extension lse) 1403 1404config ARM64_USE_LSE_ATOMICS 1405 bool "Atomic instructions" 1406 depends on JUMP_LABEL 1407 default y 1408 help 1409 As part of the Large System Extensions, ARMv8.1 introduces new 1410 atomic instructions that are designed specifically to scale in 1411 very large systems. 1412 1413 Say Y here to make use of these instructions for the in-kernel 1414 atomic routines. This incurs a small overhead on CPUs that do 1415 not support these instructions and requires the kernel to be 1416 built with binutils >= 2.25 in order for the new instructions 1417 to be used. 1418 1419config ARM64_VHE 1420 bool "Enable support for Virtualization Host Extensions (VHE)" 1421 default y 1422 help 1423 Virtualization Host Extensions (VHE) allow the kernel to run 1424 directly at EL2 (instead of EL1) on processors that support 1425 it. This leads to better performance for KVM, as they reduce 1426 the cost of the world switch. 1427 1428 Selecting this option allows the VHE feature to be detected 1429 at runtime, and does not affect processors that do not 1430 implement this feature. 1431 1432endmenu 1433 1434menu "ARMv8.2 architectural features" 1435 1436config ARM64_PMEM 1437 bool "Enable support for persistent memory" 1438 select ARCH_HAS_PMEM_API 1439 select ARCH_HAS_UACCESS_FLUSHCACHE 1440 help 1441 Say Y to enable support for the persistent memory API based on the 1442 ARMv8.2 DCPoP feature. 1443 1444 The feature is detected at runtime, and the kernel will use DC CVAC 1445 operations if DC CVAP is not supported (following the behaviour of 1446 DC CVAP itself if the system does not define a point of persistence). 1447 1448config ARM64_RAS_EXTN 1449 bool "Enable support for RAS CPU Extensions" 1450 default y 1451 help 1452 CPUs that support the Reliability, Availability and Serviceability 1453 (RAS) Extensions, part of ARMv8.2 are able to track faults and 1454 errors, classify them and report them to software. 1455 1456 On CPUs with these extensions system software can use additional 1457 barriers to determine if faults are pending and read the 1458 classification from a new set of registers. 1459 1460 Selecting this feature will allow the kernel to use these barriers 1461 and access the new registers if the system supports the extension. 1462 Platform RAS features may additionally depend on firmware support. 1463 1464config ARM64_CNP 1465 bool "Enable support for Common Not Private (CNP) translations" 1466 default y 1467 depends on ARM64_PAN || !ARM64_SW_TTBR0_PAN 1468 help 1469 Common Not Private (CNP) allows translation table entries to 1470 be shared between different PEs in the same inner shareable 1471 domain, so the hardware can use this fact to optimise the 1472 caching of such entries in the TLB. 1473 1474 Selecting this option allows the CNP feature to be detected 1475 at runtime, and does not affect PEs that do not implement 1476 this feature. 1477 1478endmenu 1479 1480menu "ARMv8.3 architectural features" 1481 1482config ARM64_PTR_AUTH 1483 bool "Enable support for pointer authentication" 1484 default y 1485 depends on (CC_HAS_SIGN_RETURN_ADDRESS || CC_HAS_BRANCH_PROT_PAC_RET) && AS_HAS_PAC 1486 # Modern compilers insert a .note.gnu.property section note for PAC 1487 # which is only understood by binutils starting with version 2.33.1. 1488 depends on LD_IS_LLD || LD_VERSION >= 23301 || (CC_IS_GCC && GCC_VERSION < 90100) 1489 depends on !CC_IS_CLANG || AS_HAS_CFI_NEGATE_RA_STATE 1490 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) 1491 help 1492 Pointer authentication (part of the ARMv8.3 Extensions) provides 1493 instructions for signing and authenticating pointers against secret 1494 keys, which can be used to mitigate Return Oriented Programming (ROP) 1495 and other attacks. 1496 1497 This option enables these instructions at EL0 (i.e. for userspace). 1498 Choosing this option will cause the kernel to initialise secret keys 1499 for each process at exec() time, with these keys being 1500 context-switched along with the process. 1501 1502 If the compiler supports the -mbranch-protection or 1503 -msign-return-address flag (e.g. GCC 7 or later), then this option 1504 will also cause the kernel itself to be compiled with return address 1505 protection. In this case, and if the target hardware is known to 1506 support pointer authentication, then CONFIG_STACKPROTECTOR can be 1507 disabled with minimal loss of protection. 1508 1509 The feature is detected at runtime. If the feature is not present in 1510 hardware it will not be advertised to userspace/KVM guest nor will it 1511 be enabled. 1512 1513 If the feature is present on the boot CPU but not on a late CPU, then 1514 the late CPU will be parked. Also, if the boot CPU does not have 1515 address auth and the late CPU has then the late CPU will still boot 1516 but with the feature disabled. On such a system, this option should 1517 not be selected. 1518 1519 This feature works with FUNCTION_GRAPH_TRACER option only if 1520 DYNAMIC_FTRACE_WITH_REGS is enabled. 1521 1522config CC_HAS_BRANCH_PROT_PAC_RET 1523 # GCC 9 or later, clang 8 or later 1524 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf) 1525 1526config CC_HAS_SIGN_RETURN_ADDRESS 1527 # GCC 7, 8 1528 def_bool $(cc-option,-msign-return-address=all) 1529 1530config AS_HAS_PAC 1531 def_bool $(cc-option,-Wa$(comma)-march=armv8.3-a) 1532 1533config AS_HAS_CFI_NEGATE_RA_STATE 1534 def_bool $(as-instr,.cfi_startproc\n.cfi_negate_ra_state\n.cfi_endproc\n) 1535 1536endmenu 1537 1538menu "ARMv8.4 architectural features" 1539 1540config ARM64_AMU_EXTN 1541 bool "Enable support for the Activity Monitors Unit CPU extension" 1542 default y 1543 help 1544 The activity monitors extension is an optional extension introduced 1545 by the ARMv8.4 CPU architecture. This enables support for version 1 1546 of the activity monitors architecture, AMUv1. 1547 1548 To enable the use of this extension on CPUs that implement it, say Y. 1549 1550 Note that for architectural reasons, firmware _must_ implement AMU 1551 support when running on CPUs that present the activity monitors 1552 extension. The required support is present in: 1553 * Version 1.5 and later of the ARM Trusted Firmware 1554 1555 For kernels that have this configuration enabled but boot with broken 1556 firmware, you may need to say N here until the firmware is fixed. 1557 Otherwise you may experience firmware panics or lockups when 1558 accessing the counter registers. Even if you are not observing these 1559 symptoms, the values returned by the register reads might not 1560 correctly reflect reality. Most commonly, the value read will be 0, 1561 indicating that the counter is not enabled. 1562 1563config AS_HAS_ARMV8_4 1564 def_bool $(cc-option,-Wa$(comma)-march=armv8.4-a) 1565 1566config ARM64_TLB_RANGE 1567 bool "Enable support for tlbi range feature" 1568 default y 1569 depends on AS_HAS_ARMV8_4 1570 help 1571 ARMv8.4-TLBI provides TLBI invalidation instruction that apply to a 1572 range of input addresses. 1573 1574 The feature introduces new assembly instructions, and they were 1575 support when binutils >= 2.30. 1576 1577endmenu 1578 1579menu "ARMv8.5 architectural features" 1580 1581config AS_HAS_ARMV8_5 1582 def_bool $(cc-option,-Wa$(comma)-march=armv8.5-a) 1583 1584config ARM64_BTI 1585 bool "Branch Target Identification support" 1586 default y 1587 help 1588 Branch Target Identification (part of the ARMv8.5 Extensions) 1589 provides a mechanism to limit the set of locations to which computed 1590 branch instructions such as BR or BLR can jump. 1591 1592 To make use of BTI on CPUs that support it, say Y. 1593 1594 BTI is intended to provide complementary protection to other control 1595 flow integrity protection mechanisms, such as the Pointer 1596 authentication mechanism provided as part of the ARMv8.3 Extensions. 1597 For this reason, it does not make sense to enable this option without 1598 also enabling support for pointer authentication. Thus, when 1599 enabling this option you should also select ARM64_PTR_AUTH=y. 1600 1601 Userspace binaries must also be specifically compiled to make use of 1602 this mechanism. If you say N here or the hardware does not support 1603 BTI, such binaries can still run, but you get no additional 1604 enforcement of branch destinations. 1605 1606config ARM64_BTI_KERNEL 1607 bool "Use Branch Target Identification for kernel" 1608 default y 1609 depends on ARM64_BTI 1610 depends on ARM64_PTR_AUTH 1611 depends on CC_HAS_BRANCH_PROT_PAC_RET_BTI 1612 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94697 1613 depends on !CC_IS_GCC || GCC_VERSION >= 100100 1614 depends on !(CC_IS_CLANG && GCOV_KERNEL) 1615 depends on (!FUNCTION_GRAPH_TRACER || DYNAMIC_FTRACE_WITH_REGS) 1616 help 1617 Build the kernel with Branch Target Identification annotations 1618 and enable enforcement of this for kernel code. When this option 1619 is enabled and the system supports BTI all kernel code including 1620 modular code must have BTI enabled. 1621 1622config CC_HAS_BRANCH_PROT_PAC_RET_BTI 1623 # GCC 9 or later, clang 8 or later 1624 def_bool $(cc-option,-mbranch-protection=pac-ret+leaf+bti) 1625 1626config ARM64_E0PD 1627 bool "Enable support for E0PD" 1628 default y 1629 help 1630 E0PD (part of the ARMv8.5 extensions) allows us to ensure 1631 that EL0 accesses made via TTBR1 always fault in constant time, 1632 providing similar benefits to KASLR as those provided by KPTI, but 1633 with lower overhead and without disrupting legitimate access to 1634 kernel memory such as SPE. 1635 1636 This option enables E0PD for TTBR1 where available. 1637 1638config ARCH_RANDOM 1639 bool "Enable support for random number generation" 1640 default y 1641 help 1642 Random number generation (part of the ARMv8.5 Extensions) 1643 provides a high bandwidth, cryptographically secure 1644 hardware random number generator. 1645 1646config ARM64_AS_HAS_MTE 1647 # Initial support for MTE went in binutils 2.32.0, checked with 1648 # ".arch armv8.5-a+memtag" below. However, this was incomplete 1649 # as a late addition to the final architecture spec (LDGM/STGM) 1650 # is only supported in the newer 2.32.x and 2.33 binutils 1651 # versions, hence the extra "stgm" instruction check below. 1652 def_bool $(as-instr,.arch armv8.5-a+memtag\nstgm xzr$(comma)[x0]) 1653 1654config ARM64_MTE 1655 bool "Memory Tagging Extension support" 1656 default y 1657 depends on ARM64_AS_HAS_MTE && ARM64_TAGGED_ADDR_ABI 1658 depends on AS_HAS_ARMV8_5 1659 # Required for tag checking in the uaccess routines 1660 depends on ARM64_PAN 1661 select ARCH_USES_HIGH_VMA_FLAGS 1662 help 1663 Memory Tagging (part of the ARMv8.5 Extensions) provides 1664 architectural support for run-time, always-on detection of 1665 various classes of memory error to aid with software debugging 1666 to eliminate vulnerabilities arising from memory-unsafe 1667 languages. 1668 1669 This option enables the support for the Memory Tagging 1670 Extension at EL0 (i.e. for userspace). 1671 1672 Selecting this option allows the feature to be detected at 1673 runtime. Any secondary CPU not implementing this feature will 1674 not be allowed a late bring-up. 1675 1676 Userspace binaries that want to use this feature must 1677 explicitly opt in. The mechanism for the userspace is 1678 described in: 1679 1680 Documentation/arm64/memory-tagging-extension.rst. 1681 1682endmenu 1683 1684config ARM64_SVE 1685 bool "ARM Scalable Vector Extension support" 1686 default y 1687 depends on !KVM || ARM64_VHE 1688 help 1689 The Scalable Vector Extension (SVE) is an extension to the AArch64 1690 execution state which complements and extends the SIMD functionality 1691 of the base architecture to support much larger vectors and to enable 1692 additional vectorisation opportunities. 1693 1694 To enable use of this extension on CPUs that implement it, say Y. 1695 1696 On CPUs that support the SVE2 extensions, this option will enable 1697 those too. 1698 1699 Note that for architectural reasons, firmware _must_ implement SVE 1700 support when running on SVE capable hardware. The required support 1701 is present in: 1702 1703 * version 1.5 and later of the ARM Trusted Firmware 1704 * the AArch64 boot wrapper since commit 5e1261e08abf 1705 ("bootwrapper: SVE: Enable SVE for EL2 and below"). 1706 1707 For other firmware implementations, consult the firmware documentation 1708 or vendor. 1709 1710 If you need the kernel to boot on SVE-capable hardware with broken 1711 firmware, you may need to say N here until you get your firmware 1712 fixed. Otherwise, you may experience firmware panics or lockups when 1713 booting the kernel. If unsure and you are not observing these 1714 symptoms, you should assume that it is safe to say Y. 1715 1716 CPUs that support SVE are architecturally required to support the 1717 Virtualization Host Extensions (VHE), so the kernel makes no 1718 provision for supporting SVE alongside KVM without VHE enabled. 1719 Thus, you will need to enable CONFIG_ARM64_VHE if you want to support 1720 KVM in the same kernel image. 1721 1722config ARM64_MODULE_PLTS 1723 bool "Use PLTs to allow module memory to spill over into vmalloc area" 1724 depends on MODULES 1725 select HAVE_MOD_ARCH_SPECIFIC 1726 help 1727 Allocate PLTs when loading modules so that jumps and calls whose 1728 targets are too far away for their relative offsets to be encoded 1729 in the instructions themselves can be bounced via veneers in the 1730 module's PLT. This allows modules to be allocated in the generic 1731 vmalloc area after the dedicated module memory area has been 1732 exhausted. 1733 1734 When running with address space randomization (KASLR), the module 1735 region itself may be too far away for ordinary relative jumps and 1736 calls, and so in that case, module PLTs are required and cannot be 1737 disabled. 1738 1739 Specific errata workaround(s) might also force module PLTs to be 1740 enabled (ARM64_ERRATUM_843419). 1741 1742config ARM64_PSEUDO_NMI 1743 bool "Support for NMI-like interrupts" 1744 select ARM_GIC_V3 1745 help 1746 Adds support for mimicking Non-Maskable Interrupts through the use of 1747 GIC interrupt priority. This support requires version 3 or later of 1748 ARM GIC. 1749 1750 This high priority configuration for interrupts needs to be 1751 explicitly enabled by setting the kernel parameter 1752 "irqchip.gicv3_pseudo_nmi" to 1. 1753 1754 If unsure, say N 1755 1756if ARM64_PSEUDO_NMI 1757config ARM64_DEBUG_PRIORITY_MASKING 1758 bool "Debug interrupt priority masking" 1759 help 1760 This adds runtime checks to functions enabling/disabling 1761 interrupts when using priority masking. The additional checks verify 1762 the validity of ICC_PMR_EL1 when calling concerned functions. 1763 1764 If unsure, say N 1765endif 1766 1767config RELOCATABLE 1768 bool "Build a relocatable kernel image" if EXPERT 1769 select ARCH_HAS_RELR 1770 default y 1771 help 1772 This builds the kernel as a Position Independent Executable (PIE), 1773 which retains all relocation metadata required to relocate the 1774 kernel binary at runtime to a different virtual address than the 1775 address it was linked at. 1776 Since AArch64 uses the RELA relocation format, this requires a 1777 relocation pass at runtime even if the kernel is loaded at the 1778 same address it was linked at. 1779 1780config RANDOMIZE_BASE 1781 bool "Randomize the address of the kernel image" 1782 select ARM64_MODULE_PLTS if MODULES 1783 select RELOCATABLE 1784 help 1785 Randomizes the virtual address at which the kernel image is 1786 loaded, as a security feature that deters exploit attempts 1787 relying on knowledge of the location of kernel internals. 1788 1789 It is the bootloader's job to provide entropy, by passing a 1790 random u64 value in /chosen/kaslr-seed at kernel entry. 1791 1792 When booting via the UEFI stub, it will invoke the firmware's 1793 EFI_RNG_PROTOCOL implementation (if available) to supply entropy 1794 to the kernel proper. In addition, it will randomise the physical 1795 location of the kernel Image as well. 1796 1797 If unsure, say N. 1798 1799config RANDOMIZE_MODULE_REGION_FULL 1800 bool "Randomize the module region over a 4 GB range" 1801 depends on RANDOMIZE_BASE 1802 default y 1803 help 1804 Randomizes the location of the module region inside a 4 GB window 1805 covering the core kernel. This way, it is less likely for modules 1806 to leak information about the location of core kernel data structures 1807 but it does imply that function calls between modules and the core 1808 kernel will need to be resolved via veneers in the module PLT. 1809 1810 When this option is not set, the module region will be randomized over 1811 a limited range that contains the [_stext, _etext] interval of the 1812 core kernel, so branch relocations are always in range. 1813 1814config CC_HAVE_STACKPROTECTOR_SYSREG 1815 def_bool $(cc-option,-mstack-protector-guard=sysreg -mstack-protector-guard-reg=sp_el0 -mstack-protector-guard-offset=0) 1816 1817config STACKPROTECTOR_PER_TASK 1818 def_bool y 1819 depends on STACKPROTECTOR && CC_HAVE_STACKPROTECTOR_SYSREG 1820 1821endmenu 1822 1823menu "Boot options" 1824 1825config ARM64_ACPI_PARKING_PROTOCOL 1826 bool "Enable support for the ARM64 ACPI parking protocol" 1827 depends on ACPI 1828 help 1829 Enable support for the ARM64 ACPI parking protocol. If disabled 1830 the kernel will not allow booting through the ARM64 ACPI parking 1831 protocol even if the corresponding data is present in the ACPI 1832 MADT table. 1833 1834config CMDLINE 1835 string "Default kernel command string" 1836 default "" 1837 help 1838 Provide a set of default command-line options at build time by 1839 entering them here. As a minimum, you should specify the the 1840 root device (e.g. root=/dev/nfs). 1841 1842choice 1843 prompt "Kernel command line type" if CMDLINE != "" 1844 default CMDLINE_FROM_BOOTLOADER 1845 help 1846 Choose how the kernel will handle the provided default kernel 1847 command line string. 1848 1849config CMDLINE_FROM_BOOTLOADER 1850 bool "Use bootloader kernel arguments if available" 1851 help 1852 Uses the command-line options passed by the boot loader. If 1853 the boot loader doesn't provide any, the default kernel command 1854 string provided in CMDLINE will be used. 1855 1856config CMDLINE_FORCE 1857 bool "Always use the default kernel command string" 1858 help 1859 Always use the default kernel command string, even if the boot 1860 loader passes other arguments to the kernel. 1861 This is useful if you cannot or don't want to change the 1862 command-line options your boot loader passes to the kernel. 1863 1864endchoice 1865 1866config EFI_STUB 1867 bool 1868 1869config EFI 1870 bool "UEFI runtime support" 1871 depends on OF && !CPU_BIG_ENDIAN 1872 depends on KERNEL_MODE_NEON 1873 select ARCH_SUPPORTS_ACPI 1874 select LIBFDT 1875 select UCS2_STRING 1876 select EFI_PARAMS_FROM_FDT 1877 select EFI_RUNTIME_WRAPPERS 1878 select EFI_STUB 1879 select EFI_GENERIC_STUB 1880 imply IMA_SECURE_AND_OR_TRUSTED_BOOT 1881 default y 1882 help 1883 This option provides support for runtime services provided 1884 by UEFI firmware (such as non-volatile variables, realtime 1885 clock, and platform reset). A UEFI stub is also provided to 1886 allow the kernel to be booted as an EFI application. This 1887 is only useful on systems that have UEFI firmware. 1888 1889config DMI 1890 bool "Enable support for SMBIOS (DMI) tables" 1891 depends on EFI 1892 default y 1893 help 1894 This enables SMBIOS/DMI feature for systems. 1895 1896 This option is only useful on systems that have UEFI firmware. 1897 However, even with this option, the resultant kernel should 1898 continue to boot on existing non-UEFI platforms. 1899 1900endmenu 1901 1902config SYSVIPC_COMPAT 1903 def_bool y 1904 depends on COMPAT && SYSVIPC 1905 1906config ARCH_ENABLE_HUGEPAGE_MIGRATION 1907 def_bool y 1908 depends on HUGETLB_PAGE && MIGRATION 1909 1910config ARCH_ENABLE_THP_MIGRATION 1911 def_bool y 1912 depends on TRANSPARENT_HUGEPAGE 1913 1914menu "Power management options" 1915 1916source "kernel/power/Kconfig" 1917 1918config ARCH_HIBERNATION_POSSIBLE 1919 def_bool y 1920 depends on CPU_PM 1921 1922config ARCH_HIBERNATION_HEADER 1923 def_bool y 1924 depends on HIBERNATION 1925 1926config ARCH_SUSPEND_POSSIBLE 1927 def_bool y 1928 1929endmenu 1930 1931menu "CPU Power Management" 1932 1933source "drivers/cpuidle/Kconfig" 1934 1935source "drivers/cpufreq/Kconfig" 1936 1937endmenu 1938 1939source "drivers/firmware/Kconfig" 1940 1941source "drivers/acpi/Kconfig" 1942 1943source "arch/arm64/kvm/Kconfig" 1944 1945if CRYPTO 1946source "arch/arm64/crypto/Kconfig" 1947endif 1948