diff options
Diffstat (limited to 'arch/arm/mm/Kconfig')
| -rw-r--r-- | arch/arm/mm/Kconfig | 36 |
1 files changed, 19 insertions, 17 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig index 549f6d3aec5b..55347662e5ed 100644 --- a/arch/arm/mm/Kconfig +++ b/arch/arm/mm/Kconfig @@ -1037,24 +1037,26 @@ config ARCH_SUPPORTS_BIG_ENDIAN This option specifies the architecture can support big endian operation. -config ARM_KERNMEM_PERMS - bool "Restrict kernel memory permissions" - depends on MMU - help - If this is set, kernel memory other than kernel text (and rodata) - will be made non-executable. The tradeoff is that each region is - padded to section-size (1MiB) boundaries (because their permissions - are different and splitting the 1M pages into 4K ones causes TLB - performance problems), wasting memory. - config DEBUG_RODATA bool "Make kernel text and rodata read-only" - depends on ARM_KERNMEM_PERMS + depends on MMU && !XIP_KERNEL + default y if CPU_V7 + help + If this is set, kernel text and rodata memory will be made + read-only, and non-text kernel memory will be made non-executable. + The tradeoff is that each region is padded to section-size (1MiB) + boundaries (because their permissions are different and splitting + the 1M pages into 4K ones causes TLB performance problems), which + can waste memory. + +config DEBUG_ALIGN_RODATA + bool "Make rodata strictly non-executable" + depends on DEBUG_RODATA default y help - If this is set, kernel text and rodata will be made read-only. This - is to help catch accidental or malicious attempts to change the - kernel's executable code. Additionally splits rodata from kernel - text so it can be made explicitly non-executable. This creates - another section-size padded region, so it can waste more memory - space while gaining the read-only protections. + If this is set, rodata will be made explicitly non-executable. This + provides protection on the rare chance that attackers might find and + use ROP gadgets that exist in the rodata section. This adds an + additional section-aligned split of rodata from kernel text so it + can be made explicitly non-executable. This padding may waste memory + space to gain the additional protection. |