diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst index 38fd5681fade..4abc84b1798c 100644 --- a/Documentation/dev-tools/kasan.rst +++ b/Documentation/dev-tools/kasan.rst @@ -13,10 +13,10 @@ KASAN uses compile-time instrumentation to insert validity checks before every memory access, and therefore requires a compiler version that supports that. Generic KASAN is supported in both GCC and Clang. With GCC it requires version -8.3.0 or later. With Clang it requires version 7.0.0 or later, but detection of +8.3.0 or later. Any supported Clang version is compatible, but detection of out-of-bounds accesses for global variables is only supported since Clang 11. -Tag-based KASAN is only supported in Clang and requires version 7.0.0 or later. +Tag-based KASAN is only supported in Clang. Currently generic KASAN is supported for the x86_64, arm64, xtensa, s390 and riscv architectures, and tag-based KASAN is supported only for arm64. diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index 047b53dbfd58..033a5bc67ac4 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -54,9 +54,9 @@ config KASAN_GENERIC Enables generic KASAN mode. This mode is supported in both GCC and Clang. With GCC it requires - version 8.3.0 or later. With Clang it requires version 7.0.0 or - later, but detection of out-of-bounds accesses for global variables - is supported only since Clang 11. + version 8.3.0 or later. Any supported Clang version is compatible, + but detection of out-of-bounds accesses for global variables is + supported only since Clang 11. This mode consumes about 1/8th of available memory at kernel start and introduces an overhead of ~x1.5 for the rest of the allocations. @@ -78,8 +78,7 @@ config KASAN_SW_TAGS Enables software tag-based KASAN mode. This mode requires Top Byte Ignore support by the CPU and therefore - is only supported for arm64. This mode requires Clang version 7.0.0 - or later. + is only supported for arm64. This mode requires Clang. This mode consumes about 1/16th of available memory at kernel start and introduces an overhead of ~20% for the rest of the allocations.