asan-stack mode still uses dangerously large kernel stacks of tens of kilobytes in some drivers, and it does not seem that anyone is working on the clang bug.
Turn it off for all clang versions to prevent users from accidentally enabling it once they update to clang-9, and to help automated build testing with clang-9. Link: https://bugs.llvm.org/show_bug.cgi?id=38809 Fixes: 6baec880d7a5 ("kasan: turn off asan-stack for clang-8 and earlier") Signed-off-by: Arnd Bergmann <a...@arndb.de> --- v2: disable the feature for all clang versions, not just 9 and below. --- lib/Kconfig.kasan | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index 4fafba1a923b..7fa97a8b5717 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -106,7 +106,6 @@ endchoice config KASAN_STACK_ENABLE bool "Enable stack instrumentation (unsafe)" if CC_IS_CLANG && !COMPILE_TEST - default !(CLANG_VERSION < 90000) depends on KASAN help The LLVM stack address sanitizer has a know problem that @@ -115,11 +114,11 @@ config KASAN_STACK_ENABLE Disabling asan-stack makes it safe to run kernels build with clang-8 with KASAN enabled, though it loses some of the functionality. - This feature is always disabled when compile-testing with clang-8 - or earlier to avoid cluttering the output in stack overflow - warnings, but clang-8 users can still enable it for builds without - CONFIG_COMPILE_TEST. On gcc and later clang versions it is - assumed to always be safe to use and enabled by default. + This feature is always disabled when compile-testing with clang + to avoid cluttering the output in stack overflow warnings, + but clang users can still enable it for builds without + CONFIG_COMPILE_TEST. On gcc it is assumed to always be safe + to use and enabled by default. config KASAN_STACK int -- 2.20.0
