kbuild: Allow LTO to be selected with KASAN_HW_TAGS

While LTO with KASAN is normally not useful, hardware tag-based KASAN
can be used also in production kernels with ARM64_MTE. Therefore, allow
KASAN_HW_TAGS to be selected together with HAS_LTO_CLANG.

Reported-by: Alistair Delva <adelva@google.com>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

diff --git a/arch/Kconfig b/arch/Kconfig
index 2bb3067..2e7139b 100644 (file)
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -638,7 +638,7 @@ config HAS_LTO_CLANG
        depends on $(success,$(AR) --help | head -n 1 | grep -qi llvm)
        depends on ARCH_SUPPORTS_LTO_CLANG
        depends on !FTRACE_MCOUNT_USE_RECORDMCOUNT
-       depends on !KASAN
+       depends on !KASAN || KASAN_HW_TAGS
        depends on !GCOV_KERNEL
        help
          The compiler and Kconfig options support building with Clang's