From 89245600941e4e0f87d77f60ee269b5e61ef4e49 Mon Sep 17 00:00:00 2001 From: Sami Tolvanen Date: Thu, 8 Sep 2022 14:54:47 -0700 Subject: cfi: Switch to -fsanitize=kcfi Switch from Clang's original forward-edge control-flow integrity implementation to -fsanitize=kcfi, which is better suited for the kernel, as it doesn't require LTO, doesn't use a jump table that requires altering function references, and won't break cross-module function address equality. Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Tested-by: Kees Cook Tested-by: Nathan Chancellor Acked-by: Peter Zijlstra (Intel) Tested-by: Peter Zijlstra (Intel) Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220908215504.3686827-6-samitolvanen@google.com --- arch/Kconfig | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'arch/Kconfig') diff --git a/arch/Kconfig b/arch/Kconfig index 5fd875e18c99..1c1eca0c0019 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -738,11 +738,13 @@ config ARCH_SUPPORTS_CFI_CLANG An architecture should select this option if it can support Clang's Control-Flow Integrity (CFI) checking. +config ARCH_USES_CFI_TRAPS + bool + config CFI_CLANG bool "Use Clang's Control Flow Integrity (CFI)" - depends on LTO_CLANG && ARCH_SUPPORTS_CFI_CLANG - depends on CLANG_VERSION >= 140000 - select KALLSYMS + depends on ARCH_SUPPORTS_CFI_CLANG + depends on $(cc-option,-fsanitize=kcfi) help This option enables Clang’s forward-edge Control Flow Integrity (CFI) checking, where the compiler injects a runtime check to each -- cgit v1.2.3