diff options
Diffstat (limited to 'arch/arm/mm/Kconfig')
| -rw-r--r-- | arch/arm/mm/Kconfig | 46 |
1 files changed, 35 insertions, 11 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 58afba346729..fc439c2c16f8 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -386,6 +386,7 @@ config CPU_V6 select CPU_PABRT_V6 select CPU_THUMB_CAPABLE select CPU_TLB_V6 if MMU + select SMP_ON_UP if SMP # ARMv6k config CPU_V6K @@ -630,7 +631,11 @@ config CPU_USE_DOMAINS bool help This option enables or disables the use of domain switching - via the set_fs() function. + using the DACR (domain access control register) to protect memory + domains from each other. In Linux we use three domains: kernel, user + and IO. The domains are used to protect userspace from kernelspace + and to handle IO-space as a special type of memory by assigning + manager or client roles to running code (such as a process). config CPU_V7M_NUM_IRQ int "Number of external interrupts connected to the NVIC" @@ -737,15 +742,29 @@ config SWP_EMULATE If unsure, say Y. +choice + prompt "CPU Endianess" + default CPU_LITTLE_ENDIAN + +config CPU_LITTLE_ENDIAN + bool "Built little-endian kernel" + help + Say Y if you plan on running a kernel in little-endian mode. + This is the default and is used in practically all modern user + space builds. + config CPU_BIG_ENDIAN bool "Build big-endian kernel" - depends on ARCH_SUPPORTS_BIG_ENDIAN depends on !LD_IS_LLD help Say Y if you plan on running a kernel in big-endian mode. - Note that your board must be properly built and your board - port must properly enable any big-endian related features - of your chipset/board/processor. + This works on many machines using ARMv6 or newer processors + but requires big-endian user space. + + The only ARMv5 platform with big-endian support is + Intel IXP4xx. + +endchoice config CPU_ENDIAN_BE8 bool @@ -830,6 +849,7 @@ config CPU_BPREDICT_DISABLE config CPU_SPECTRE bool + select GENERIC_CPU_VULNERABILITIES config HARDEN_BRANCH_PREDICTOR bool "Harden the branch predictor against aliasing attacks" if EXPERT @@ -850,6 +870,16 @@ config HARDEN_BRANCH_PREDICTOR If unsure, say Y. +config HARDEN_BRANCH_HISTORY + bool "Harden Spectre style attacks against branch history" if EXPERT + depends on CPU_SPECTRE + default y + help + Speculation attacks against some high-performance processors can + make use of branch history to influence future speculation. When + taking an exception, a sequence of branches overwrites the branch + history, or branch history is invalidated. + config TLS_REG_EMUL bool select NEED_KUSER_HELPERS @@ -1110,12 +1140,6 @@ config ARM_DMA_MEM_BUFFERABLE config ARM_HEAVY_MB bool -config ARCH_SUPPORTS_BIG_ENDIAN - bool - help - This option specifies the architecture can support big endian - operation. - config DEBUG_ALIGN_RODATA bool "Make rodata strictly non-executable" depends on STRICT_KERNEL_RWX |