diff options
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 71 |
1 files changed, 26 insertions, 45 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 5f8a5d84dbbe..48b5e103bdb0 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -72,11 +72,11 @@ config KPROBES If in doubt, say "N". config JUMP_LABEL - bool "Optimize very unlikely/likely branches" - depends on HAVE_ARCH_JUMP_LABEL - depends on CC_HAS_ASM_GOTO - help - This option enables a transparent branch optimization that + bool "Optimize very unlikely/likely branches" + depends on HAVE_ARCH_JUMP_LABEL + depends on CC_HAS_ASM_GOTO + 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. @@ -84,7 +84,7 @@ config JUMP_LABEL 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", + 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 @@ -151,8 +151,8 @@ config HAVE_EFFICIENT_UNALIGNED_ACCESS information on the topic of unaligned memory accesses. config ARCH_USE_BUILTIN_BSWAP - bool - help + 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 @@ -221,10 +221,10 @@ config HAVE_DMA_CONTIGUOUS bool config GENERIC_SMP_IDLE_THREAD - bool + bool config GENERIC_IDLE_POLL_SETUP - bool + bool config ARCH_HAS_FORTIFY_SOURCE bool @@ -257,7 +257,7 @@ config ARCH_HAS_UNCACHED_SEGMENT # Select if arch init_task must go in the __init_task_data section config ARCH_TASK_STRUCT_ON_STACK - bool + bool # Select if arch has its private alloc_task_struct() function config ARCH_TASK_STRUCT_ALLOCATOR @@ -796,16 +796,9 @@ config OLD_SIGACTION config COMPAT_OLD_SIGACTION bool -config 64BIT_TIME - def_bool y - help - This should be selected by all architectures that need to support - new system calls with a 64-bit time_t. This is relevant on all 32-bit - architectures, and 64-bit architectures as part of compat syscall - handling. - config COMPAT_32BIT_TIME - def_bool !64BIT || COMPAT + bool "Provide system calls for 32-bit time_t" + default !64BIT || COMPAT help This enables 32 bit time_t support in addition to 64 bit time_t support. This is relevant on all 32-bit architectures, and 64-bit architectures @@ -843,16 +836,17 @@ config HAVE_ARCH_VMAP_STACK config VMAP_STACK default y bool "Use a virtually-mapped stack" - depends on HAVE_ARCH_VMAP_STACK && !KASAN + depends on HAVE_ARCH_VMAP_STACK + depends on !KASAN || KASAN_VMALLOC ---help--- Enable this if you want the use virtually-mapped kernel stacks with guard pages. This causes kernel stack overflows to be caught immediately rather than causing difficult-to-diagnose corruption. - This is presently incompatible with KASAN because KASAN expects - the stack to map directly to the KASAN shadow map using a formula - that is incorrect if the stack is in vmalloc space. + To use this with KASAN, the architecture must support backing + virtual mappings with real shadow memory, and KASAN_VMALLOC must + be enabled. config ARCH_OPTIONAL_KERNEL_RWX def_bool n @@ -892,27 +886,6 @@ config STRICT_MODULE_RWX config ARCH_HAS_PHYS_TO_DMA bool -config ARCH_HAS_REFCOUNT - bool - help - An architecture selects this when it has implemented refcount_t - using open coded assembly primitives that provide an optimized - refcount_t implementation, possibly at the expense of some full - refcount state checks of CONFIG_REFCOUNT_FULL=y. - - The refcount overflow check behavior, however, must be retained. - Catching overflows is the primary security concern for protecting - against bugs in reference counts. - -config REFCOUNT_FULL - bool "Perform full reference count validation at the expense of speed" - help - Enabling this switches the refcounting infrastructure from a fast - unchecked atomic_t implementation to a fully state checked - implementation, which can be (slightly) slower but provides protections - against various use-after-free conditions that can be used in - security flaw exploits. - config HAVE_ARCH_COMPILER_H bool help @@ -960,6 +933,14 @@ config RELR config ARCH_HAS_MEM_ENCRYPT bool +config HAVE_SPARSE_SYSCALL_NR + 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. + source "kernel/gcov/Kconfig" source "scripts/gcc-plugins/Kconfig" |