Hi all, Currently KASAN is supported but only the generic one. SW-tag and HW-tag based KASAN have less impact on memory footprint or performance, and are worth supporting.
The following patch adds a choice menu in the menuconfig, allowing SW-tag or HW-tag to be selected. commit a1db3ed8ad00a136f815a48e07962c96d777b38d Author: Zhen XIN <[email protected]> Date: Tue Jul 4 09:44:01 2023 +0000 build: Add option KERNEL_KASAN_SW_TAGS and HW_TAGS Add choice menu for software and hardware Tag-Based KASAN, in addition to the generic one. Signed-off-by: Zhen XIN <[email protected]> diff --git a/config/Config-kernel.in b/config/Config-kernel.in index 7de0d17b5e..00276bffb4 100644 --- a/config/Config-kernel.in +++ b/config/Config-kernel.in @@ -184,16 +184,73 @@ config KERNEL_KASAN_VMALLOC will have no effect. if KERNEL_KASAN - config KERNEL_KASAN_GENERIC - def_bool y +choice + prompt "KASAN mode" + depends on KERNEL_KASAN + default KERNEL_KASAN_GENERIC + help + KASAN has three modes: + + 1. Generic KASAN (supported by many architectures, enabled with + CONFIG_KASAN_GENERIC, similar to userspace ASan), + 2. Software Tag-Based KASAN (arm64 only, based on software memory + tagging, enabled with CONFIG_KASAN_SW_TAGS, similar to userspace + HWASan), and + 3. Hardware Tag-Based KASAN (arm64 only, based on hardware memory + tagging, enabled with CONFIG_KASAN_HW_TAGS). + +config KERNEL_KASAN_GENERIC + bool "Generic KASAN" + select KERNEL_SLUB_DEBUG + help + Enables Generic KASAN. + + Consumes about 1/8th of available memory at kernel start and adds an + overhead of ~50% for dynamic allocations. + The performance slowdown is ~x3. + +config KERNEL_KASAN_SW_TAGS + bool "Software Tag-Based KASAN" + depends on aarch64 + select KERNEL_SLUB_DEBUG + help + Enables Software Tag-Based KASAN. + + Supported only on arm64 CPUs and relies on Top Byte Ignore. + + Consumes about 1/16th of available memory at kernel start and + add an overhead of ~20% for dynamic allocations. + + May potentially introduce problems related to pointer casting and + comparison, as it embeds a tag into the top byte of each pointer. + +config KERNEL_KASAN_HW_TAGS + bool "Hardware Tag-Based KASAN" + depends on aarch64 + select KERNEL_SLUB_DEBUG + select KERNEL_ARM64_MTE + help + Enables Hardware Tag-Based KASAN. + + Supported only on arm64 CPUs starting from ARMv8.5 and relies on + Memory Tagging Extension and Top Byte Ignore. + + Consumes about 1/32nd of available memory. + + May potentially introduce problems related to pointer casting and + comparison, as it embeds a tag into the top byte of each pointer. + +endchoice + + config KERNEL_ARM64_MTE + def_bool n - config KERNEL_KASAN_SW_TAGS - def_bool n endif choice prompt "Instrumentation type" depends on KERNEL_KASAN + depends on !KERNEL_KASAN_HW_TAGS default KERNEL_KASAN_OUTLINE config KERNEL_KASAN_OUTLINE _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/mailman/listinfo/openwrt-devel
