diff options
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 436 |
1 files changed, 314 insertions, 122 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 761d169ba7fd..59dee290d94b 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -11,31 +11,44 @@ source "arch/$(SRCARCH)/Kconfig" menu "General architecture-dependent options" -config CRASH_CORE +config ARCH_HAS_SUBPAGE_FAULTS bool + help + Select if the architecture can check permissions at sub-page + granularity (e.g. arm64 MTE). The probe_user_*() functions + must be implemented. -config KEXEC_CORE - select CRASH_CORE +config HOTPLUG_SMT bool -config KEXEC_ELF +config SMT_NUM_THREADS_DYNAMIC bool -config HAVE_IMA_KEXEC +# Selected by HOTPLUG_CORE_SYNC_DEAD or HOTPLUG_CORE_SYNC_FULL +config HOTPLUG_CORE_SYNC bool -config ARCH_HAS_SUBPAGE_FAULTS +# Basic CPU dead synchronization selected by architecture +config HOTPLUG_CORE_SYNC_DEAD bool - help - Select if the architecture can check permissions at sub-page - granularity (e.g. arm64 MTE). The probe_user_*() functions - must be implemented. + select HOTPLUG_CORE_SYNC -config HOTPLUG_SMT +# Full CPU synchronization with alive state selected by architecture +config HOTPLUG_CORE_SYNC_FULL bool + select HOTPLUG_CORE_SYNC_DEAD if HOTPLUG_CPU + select HOTPLUG_CORE_SYNC + +config HOTPLUG_SPLIT_STARTUP + bool + select HOTPLUG_CORE_SYNC_FULL + +config HOTPLUG_PARALLEL + bool + select HOTPLUG_SPLIT_STARTUP config GENERIC_ENTRY - bool + bool config KPROBES bool "Kprobes" @@ -53,29 +66,28 @@ config KPROBES config JUMP_LABEL bool "Optimize very unlikely/likely branches" depends on HAVE_ARCH_JUMP_LABEL - depends on CC_HAS_ASM_GOTO select OBJTOOL if HAVE_JUMP_LABEL_HACK help - This option enables a transparent branch optimization that - makes certain almost-always-true or almost-always-false branch - conditions even cheaper to execute within the kernel. + This option enables a transparent branch optimization that + makes certain almost-always-true or almost-always-false branch + conditions even cheaper to execute within the kernel. - Certain performance-sensitive kernel code, such as trace points, - scheduler functionality, networking code and KVM have such - branches and include support for this optimization technique. + Certain performance-sensitive kernel code, such as trace points, + scheduler functionality, networking code and KVM have such + branches and include support for this optimization technique. - If it is detected that the compiler has support for "asm goto", - the kernel will compile such branches with just a nop - instruction. When the condition flag is toggled to true, the - nop will be converted to a jump instruction to execute the - conditional block of instructions. + If it is detected that the compiler has support for "asm goto", + the kernel will compile such branches with just a nop + instruction. When the condition flag is toggled to true, the + nop will be converted to a jump instruction to execute the + conditional block of instructions. - This technique lowers overhead and stress on the branch prediction - of the processor and generally makes the kernel faster. The update - of the condition is slower, but those are always very rare. + This technique lowers overhead and stress on the branch prediction + of the processor and generally makes the kernel faster. The update + of the condition is slower, but those are always very rare. - ( On 32-bit x86, the necessary options added to the compiler - flags may increase the size of the kernel slightly. ) + ( On 32-bit x86, the necessary options added to the compiler + flags may increase the size of the kernel slightly. ) config STATIC_KEYS_SELFTEST bool "Static key selftest" @@ -99,9 +111,9 @@ config KPROBES_ON_FTRACE depends on KPROBES && HAVE_KPROBES_ON_FTRACE depends on DYNAMIC_FTRACE_WITH_REGS help - If function tracer is enabled and the arch supports full - passing of pt_regs to function tracing, then kprobes can - optimize on top of function tracing. + If function tracer is enabled and the arch supports full + passing of pt_regs to function tracing, then kprobes can + optimize on top of function tracing. config UPROBES def_bool n @@ -155,21 +167,21 @@ config HAVE_EFFICIENT_UNALIGNED_ACCESS config ARCH_USE_BUILTIN_BSWAP bool help - Modern versions of GCC (since 4.4) have builtin functions - for handling byte-swapping. Using these, instead of the old - inline assembler that the architecture code provides in the - __arch_bswapXX() macros, allows the compiler to see what's - happening and offers more opportunity for optimisation. In - particular, the compiler will be able to combine the byteswap - with a nearby load or store and use load-and-swap or - store-and-swap instructions if the architecture has them. It - should almost *never* result in code which is worse than the - hand-coded assembler in <asm/swab.h>. But just in case it - does, the use of the builtins is optional. + Modern versions of GCC (since 4.4) have builtin functions + for handling byte-swapping. Using these, instead of the old + inline assembler that the architecture code provides in the + __arch_bswapXX() macros, allows the compiler to see what's + happening and offers more opportunity for optimisation. In + particular, the compiler will be able to combine the byteswap + with a nearby load or store and use load-and-swap or + store-and-swap instructions if the architecture has them. It + should almost *never* result in code which is worse than the + hand-coded assembler in <asm/swab.h>. But just in case it + does, the use of the builtins is optional. - Any architecture with load-and-swap or store-and-swap - instructions should set this. And it shouldn't hurt to set it - on architectures that don't have such instructions. + Any architecture with load-and-swap or store-and-swap + instructions should set this. And it shouldn't hurt to set it + on architectures that don't have such instructions. config KRETPROBES def_bool y @@ -286,17 +298,16 @@ config ARCH_HAS_DMA_SET_UNCACHED config ARCH_HAS_DMA_CLEAR_UNCACHED bool -# Select if arch init_task must go in the __init_task_data section -config ARCH_TASK_STRUCT_ON_STACK +config ARCH_HAS_CPU_FINALIZE_INIT bool -# Select if arch has its private alloc_task_struct() function -config ARCH_TASK_STRUCT_ALLOCATOR +# The architecture has a per-task state that includes the mm's PASID +config ARCH_HAS_CPU_PASID bool + select IOMMU_MM_DATA config HAVE_ARCH_THREAD_STRUCT_WHITELIST bool - depends on !ARCH_TASK_STRUCT_ALLOCATOR help An architecture should select this to provide hardened usercopy knowledge about what region of the thread_struct should be @@ -305,10 +316,6 @@ config HAVE_ARCH_THREAD_STRUCT_WHITELIST should be implemented. Without this, the entire thread_struct field in task_struct will be left whitelisted. -# Select if arch has its private alloc_thread_stack() function -config ARCH_THREAD_STACK_ALLOCATOR - bool - # Select if arch wants to size task_struct dynamically via arch_task_struct_size: config ARCH_WANTS_DYNAMIC_TASK_STRUCT bool @@ -356,6 +363,12 @@ config HAVE_RSEQ This symbol should be selected by an architecture if it supports an implementation of restartable sequences. +config HAVE_RUST + bool + help + This symbol should be selected by an architecture if it + supports Rust. + config HAVE_FUNCTION_ARG_ACCESS_API bool help @@ -395,20 +408,14 @@ config HAVE_HARDLOCKUP_DETECTOR_PERF The arch chooses to use the generic perf-NMI-based hardlockup detector. Must define HAVE_PERF_EVENTS_NMI. -config HAVE_NMI_WATCHDOG - depends on HAVE_NMI - bool - help - The arch provides a low level NMI watchdog. It provides - asm/nmi.h, and defines its own arch_touch_nmi_watchdog(). - config HAVE_HARDLOCKUP_DETECTOR_ARCH bool - select HAVE_NMI_WATCHDOG help - The arch chooses to provide its own hardlockup detector, which is - a superset of the HAVE_NMI_WATCHDOG. It also conforms to config - interfaces and parameters provided by hardlockup detector subsystem. + The arch provides its own hardlockup detector implementation instead + of the generic ones. + + It uses the same command line parameters, and sysctl interface, + as the generic hardlockup detectors. config HAVE_PERF_REGS bool @@ -460,9 +467,44 @@ config ARCH_WANT_IRQS_OFF_ACTIVATE_MM irqs disabled over activate_mm. Architectures that do IPI based TLB shootdowns should enable this. +# Use normal mm refcounting for MMU_LAZY_TLB kernel thread references. +# MMU_LAZY_TLB_REFCOUNT=n can improve the scalability of context switching +# to/from kernel threads when the same mm is running on a lot of CPUs (a large +# multi-threaded application), by reducing contention on the mm refcount. +# +# This can be disabled if the architecture ensures no CPUs are using an mm as a +# "lazy tlb" beyond its final refcount (i.e., by the time __mmdrop frees the mm +# or its kernel page tables). This could be arranged by arch_exit_mmap(), or +# final exit(2) TLB flush, for example. +# +# To implement this, an arch *must*: +# Ensure the _lazy_tlb variants of mmgrab/mmdrop are used when manipulating +# the lazy tlb reference of a kthread's ->active_mm (non-arch code has been +# converted already). +config MMU_LAZY_TLB_REFCOUNT + def_bool y + depends on !MMU_LAZY_TLB_SHOOTDOWN + +# This option allows MMU_LAZY_TLB_REFCOUNT=n. It ensures no CPUs are using an +# mm as a lazy tlb beyond its last reference count, by shooting down these +# users before the mm is deallocated. __mmdrop() first IPIs all CPUs that may +# be using the mm as a lazy tlb, so that they may switch themselves to using +# init_mm for their active mm. mm_cpumask(mm) is used to determine which CPUs +# may be using mm as a lazy tlb mm. +# +# To implement this, an arch *must*: +# - At the time of the final mmdrop of the mm, ensure mm_cpumask(mm) contains +# at least all possible CPUs in which the mm is lazy. +# - It must meet the requirements for MMU_LAZY_TLB_REFCOUNT=n (see above). +config MMU_LAZY_TLB_SHOOTDOWN + bool + config ARCH_HAVE_NMI_SAFE_CMPXCHG bool +config ARCH_HAS_NMI_SAFE_THIS_CPU_OPS + bool + config HAVE_ALIGNED_STRUCT_PAGE bool help @@ -630,7 +672,8 @@ config ARCH_SUPPORTS_SHADOW_CALL_STACK config SHADOW_CALL_STACK bool "Shadow Call Stack" depends on ARCH_SUPPORTS_SHADOW_CALL_STACK - depends on DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER + depends on DYNAMIC_FTRACE_WITH_ARGS || DYNAMIC_FTRACE_WITH_REGS || !FUNCTION_GRAPH_TRACER + depends on MMU help This option enables the compiler's Shadow Call Stack, which uses a shadow stack to protect function return addresses from @@ -646,6 +689,13 @@ config SHADOW_CALL_STACK reading and writing arbitrary memory may be able to locate them and hijack control flow by modifying the stacks. +config DYNAMIC_SCS + bool + help + Set by the arch code if it relies on code patching to insert the + shadow call stack push and pop instructions rather than on the + compiler. + config LTO bool help @@ -678,7 +728,9 @@ config HAS_LTO_CLANG depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm) depends on ARCH_SUPPORTS_LTO_CLANG depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT - depends on !KASAN || KASAN_HW_TAGS + # https://github.com/ClangBuiltLinux/linux/issues/1721 + depends on (!KASAN || KASAN_HW_TAGS || CLANG_VERSION >= 170000) || !DEBUG_INFO + depends on (!KCOV || CLANG_VERSION >= 170000) || !DEBUG_INFO depends on !GCOV_KERNEL help The compiler and Kconfig options support building with Clang's @@ -705,13 +757,13 @@ config LTO_CLANG_FULL depends on !COMPILE_TEST select LTO_CLANG help - This option enables Clang's full Link Time Optimization (LTO), which - allows the compiler to optimize the kernel globally. If you enable - this option, the compiler generates LLVM bitcode instead of ELF - object files, and the actual compilation from bitcode happens at - the LTO link step, which may take several minutes depending on the - kernel configuration. More information can be found from LLVM's - documentation: + This option enables Clang's full Link Time Optimization (LTO), which + allows the compiler to optimize the kernel globally. If you enable + this option, the compiler generates LLVM bitcode instead of ELF + object files, and the actual compilation from bitcode happens at + the LTO link step, which may take several minutes depending on the + kernel configuration. More information can be found from LLVM's + documentation: https://llvm.org/docs/LinkTimeOptimization.html @@ -739,11 +791,13 @@ config ARCH_SUPPORTS_CFI_CLANG An architecture should select this option if it can support Clang's Control-Flow Integrity (CFI) checking. +config ARCH_USES_CFI_TRAPS + bool + config CFI_CLANG bool "Use Clang's Control Flow Integrity (CFI)" - depends on LTO_CLANG && ARCH_SUPPORTS_CFI_CLANG - depends on CLANG_VERSION >= 140000 - select KALLSYMS + depends on ARCH_SUPPORTS_CFI_CLANG + depends on $(cc-option,-fsanitize=kcfi) help This option enables Clang’s forward-edge Control Flow Integrity (CFI) checking, where the compiler injects a runtime check to each @@ -755,16 +809,6 @@ config CFI_CLANG https://clang.llvm.org/docs/ControlFlowIntegrity.html -config CFI_CLANG_SHADOW - bool "Use CFI shadow to speed up cross-module checks" - default y - depends on CFI_CLANG && MODULES - help - If you select this option, the kernel builds a fast look-up table of - CFI check functions in loaded modules to reduce performance overhead. - - If unsure, say Y. - config CFI_PERMISSIVE bool "Use CFI in permissive mode" depends on CFI_CLANG @@ -880,6 +924,14 @@ config HAVE_ARCH_HUGE_VMALLOC config ARCH_WANT_HUGE_PMD_SHARE bool +# Archs that want to use pmd_mkwrite on kernel memory need it defined even +# if there are no userspace memory management features that use it +config ARCH_WANT_KERNEL_PMD_MKWRITE + bool + +config ARCH_WANT_PMD_MKWRITE + def_bool TRANSPARENT_HUGEPAGE || ARCH_WANT_KERNEL_PMD_MKWRITE + config HAVE_ARCH_SOFT_DIRTY bool @@ -924,6 +976,9 @@ config HAVE_SOFTIRQ_ON_OWN_STACK Architecture provides a function to run __do_softirq() on a separate stack. +config SOFTIRQ_ON_OWN_STACK + def_bool HAVE_SOFTIRQ_ON_OWN_STACK && !PREEMPT_RT + config ALTERNATE_USER_ADDRESS_SPACE bool help @@ -1023,18 +1078,107 @@ config HAVE_ARCH_COMPAT_MMAP_BASES and vice-versa 32-bit applications to call 64-bit mmap(). Required for applications doing different bitness syscalls. +config HAVE_PAGE_SIZE_4KB + bool + +config HAVE_PAGE_SIZE_8KB + bool + +config HAVE_PAGE_SIZE_16KB + bool + +config HAVE_PAGE_SIZE_32KB + bool + +config HAVE_PAGE_SIZE_64KB + bool + +config HAVE_PAGE_SIZE_256KB + bool + +choice + prompt "MMU page size" + +config PAGE_SIZE_4KB + bool "4KiB pages" + depends on HAVE_PAGE_SIZE_4KB + help + This option select the standard 4KiB Linux page size and the only + available option on many architectures. Using 4KiB page size will + minimize memory consumption and is therefore recommended for low + memory systems. + Some software that is written for x86 systems makes incorrect + assumptions about the page size and only runs on 4KiB pages. + +config PAGE_SIZE_8KB + bool "8KiB pages" + depends on HAVE_PAGE_SIZE_8KB + help + This option is the only supported page size on a few older + processors, and can be slightly faster than 4KiB pages. + +config PAGE_SIZE_16KB + bool "16KiB pages" + depends on HAVE_PAGE_SIZE_16KB + help + This option is usually a good compromise between memory + consumption and performance for typical desktop and server + workloads, often saving a level of page table lookups compared + to 4KB pages as well as reducing TLB pressure and overhead of + per-page operations in the kernel at the expense of a larger + page cache. + +config PAGE_SIZE_32KB + bool "32KiB pages" + depends on HAVE_PAGE_SIZE_32KB + help + Using 32KiB page size will result in slightly higher performance + kernel at the price of higher memory consumption compared to + 16KiB pages. This option is available only on cnMIPS cores. + Note that you will need a suitable Linux distribution to + support this. + +config PAGE_SIZE_64KB + bool "64KiB pages" + depends on HAVE_PAGE_SIZE_64KB + help + Using 64KiB page size will result in slightly higher performance + kernel at the price of much higher memory consumption compared to + 4KiB or 16KiB pages. + This is not suitable for general-purpose workloads but the + better performance may be worth the cost for certain types of + supercomputing or database applications that work mostly with + large in-memory data rather than small files. + +config PAGE_SIZE_256KB + bool "256KiB pages" + depends on HAVE_PAGE_SIZE_256KB + help + 256KiB pages have little practical value due to their extreme + memory usage. The kernel will only be able to run applications + that have been compiled with '-zmax-page-size' set to 256KiB + (the default is 64KiB or 4KiB on most architectures). + +endchoice + config PAGE_SIZE_LESS_THAN_64KB def_bool y - depends on !ARM64_64K_PAGES - depends on !IA64_PAGE_SIZE_64KB depends on !PAGE_SIZE_64KB - depends on !PARISC_PAGE_SIZE_64KB depends on PAGE_SIZE_LESS_THAN_256KB config PAGE_SIZE_LESS_THAN_256KB def_bool y depends on !PAGE_SIZE_256KB +config PAGE_SHIFT + int + default 12 if PAGE_SIZE_4KB + default 13 if PAGE_SIZE_8KB + default 14 if PAGE_SIZE_16KB + default 15 if PAGE_SIZE_32KB + default 16 if PAGE_SIZE_64KB + default 18 if PAGE_SIZE_256KB + # This allows to use a set of generic functions to determine mmap base # address by giving priority to top-down scheme only if the process # is not in legacy mode (compat task, unlimited stack size or @@ -1146,13 +1290,6 @@ config COMPAT_32BIT_TIME config ARCH_NO_PREEMPT bool -config ARCH_EPHEMERAL_INODES - def_bool n - help - An arch should select this symbol if it doesn't keep track of inode - instances on its own, but instead relies on something else (e.g. the - host kernel for an UML kernel). - config ARCH_SUPPORTS_RT bool @@ -1320,9 +1457,9 @@ config ARCH_HAS_CC_PLATFORM bool config HAVE_SPARSE_SYSCALL_NR - bool - help - An architecture should select this if its syscall numbering is sparse + bool + help + An architecture should select this if its syscall numbering is sparse to save space. For example, MIPS architecture has a syscall array with entries at 4000, 5000 and 6000 locations. This option turns on syscall related optimizations for a given architecture. @@ -1346,35 +1483,35 @@ config HAVE_PREEMPT_DYNAMIC_CALL depends on HAVE_STATIC_CALL select HAVE_PREEMPT_DYNAMIC help - An architecture should select this if it can handle the preemption - model being selected at boot time using static calls. + An architecture should select this if it can handle the preemption + model being selected at boot time using static calls. - Where an architecture selects HAVE_STATIC_CALL_INLINE, any call to a - preemption function will be patched directly. + Where an architecture selects HAVE_STATIC_CALL_INLINE, any call to a + preemption function will be patched directly. - Where an architecture does not select HAVE_STATIC_CALL_INLINE, any - call to a preemption function will go through a trampoline, and the - trampoline will be patched. + Where an architecture does not select HAVE_STATIC_CALL_INLINE, any + call to a preemption function will go through a trampoline, and the + trampoline will be patched. - It is strongly advised to support inline static call to avoid any - overhead. + It is strongly advised to support inline static call to avoid any + overhead. config HAVE_PREEMPT_DYNAMIC_KEY bool - depends on HAVE_ARCH_JUMP_LABEL && CC_HAS_ASM_GOTO + depends on HAVE_ARCH_JUMP_LABEL select HAVE_PREEMPT_DYNAMIC help - An architecture should select this if it can handle the preemption - model being selected at boot time using static keys. + An architecture should select this if it can handle the preemption + model being selected at boot time using static keys. - Each preemption function will be given an early return based on a - static key. This should have slightly lower overhead than non-inline - static calls, as this effectively inlines each trampoline into the - start of its callee. This may avoid redundant work, and may - integrate better with CFI schemes. + Each preemption function will be given an early return based on a + static key. This should have slightly lower overhead than non-inline + static calls, as this effectively inlines each trampoline into the + start of its callee. This may avoid redundant work, and may + integrate better with CFI schemes. - This will have greater overhead than using inline static calls as - the call to the preemption function cannot be entirely elided. + This will have greater overhead than using inline static calls as + the call to the preemption function cannot be entirely elided. config ARCH_WANT_LD_ORPHAN_WARN bool @@ -1397,8 +1534,8 @@ config ARCH_SUPPORTS_PAGE_TABLE_CHECK config ARCH_SPLIT_ARG64 bool help - If a 32-bit architecture requires 64-bit arguments to be split into - pairs of 32-bit arguments, select this option. + If a 32-bit architecture requires 64-bit arguments to be split into + pairs of 32-bit arguments, select this option. config ARCH_HAS_ELFCORE_COMPAT bool @@ -1406,6 +1543,9 @@ config ARCH_HAS_ELFCORE_COMPAT config ARCH_HAS_PARANOID_L1D_FLUSH bool +config ARCH_HAVE_TRACE_MMIO_ACCESS + bool + config DYNAMIC_SIGFRAME bool @@ -1413,8 +1553,60 @@ config DYNAMIC_SIGFRAME config HAVE_ARCH_NODE_DEV_GROUP bool +config ARCH_HAS_HW_PTE_YOUNG + bool + help + Architectures that select this option are capable of setting the + accessed bit in PTE entries when using them as part of linear address + translations. Architectures that require runtime check should select + this option and override arch_has_hw_pte_young(). + +config ARCH_HAS_NONLEAF_PMD_YOUNG + bool + help + Architectures that select this option are capable of setting the + accessed bit in non-leaf PMD entries when using them as part of linear + address translations. Page table walkers that clear the accessed bit + may use this capability to reduce their search space. + source "kernel/gcov/Kconfig" source "scripts/gcc-plugins/Kconfig" +config FUNCTION_ALIGNMENT_4B + bool + +config FUNCTION_ALIGNMENT_8B + bool + +config FUNCTION_ALIGNMENT_16B + bool + +config FUNCTION_ALIGNMENT_32B + bool + +config FUNCTION_ALIGNMENT_64B + bool + +config FUNCTION_ALIGNMENT + int + default 64 if FUNCTION_ALIGNMENT_64B + default 32 if FUNCTION_ALIGNMENT_32B + default 16 if FUNCTION_ALIGNMENT_16B + default 8 if FUNCTION_ALIGNMENT_8B + default 4 if FUNCTION_ALIGNMENT_4B + default 0 + +config CC_HAS_MIN_FUNCTION_ALIGNMENT + # Detect availability of the GCC option -fmin-function-alignment which + # guarantees minimal alignment for all functions, unlike + # -falign-functions which the compiler ignores for cold functions. + def_bool $(cc-option, -fmin-function-alignment=8) + +config CC_HAS_SANE_FUNCTION_ALIGNMENT + # Set if the guaranteed alignment with -fmin-function-alignment is + # available or extra care is required in the kernel. Clang provides + # strict alignment always, even with -falign-functions. + def_bool CC_HAS_MIN_FUNCTION_ALIGNMENT || CC_IS_CLANG + endmenu |