diff options
Diffstat (limited to 'arch/Kconfig')
| -rw-r--r-- | arch/Kconfig | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index ecfd3520b676..f6a85ba6cba2 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -692,6 +692,51 @@ config LTO_CLANG_THIN If unsure, say Y. endchoice +config ARCH_SUPPORTS_CFI_CLANG + bool + help + An architecture should select this option if it can support Clang's + Control-Flow Integrity (CFI) checking. + +config CFI_CLANG + bool "Use Clang's Control Flow Integrity (CFI)" + depends on LTO_CLANG && ARCH_SUPPORTS_CFI_CLANG + # Clang >= 12: + # - https://bugs.llvm.org/show_bug.cgi?id=46258 + # - https://bugs.llvm.org/show_bug.cgi?id=47479 + depends on CLANG_VERSION >= 120000 + select KALLSYMS + help + This option enables Clang’s forward-edge Control Flow Integrity + (CFI) checking, where the compiler injects a runtime check to each + indirect function call to ensure the target is a valid function with + the correct static type. This restricts possible call targets and + makes it more difficult for an attacker to exploit bugs that allow + the modification of stored function pointers. More information can be + found from Clang's documentation: + + https://clang.llvm.org/docs/ControlFlowIntegrity.html + +config CFI_CLANG_SHADOW + bool "Use CFI shadow to speed up cross-module checks" + default y + depends on CFI_CLANG && MODULES + help + If you select this option, the kernel builds a fast look-up table of + CFI check functions in loaded modules to reduce performance overhead. + + If unsure, say Y. + +config CFI_PERMISSIVE + bool "Use CFI in permissive mode" + depends on CFI_CLANG + help + When selected, Control Flow Integrity (CFI) violations result in a + warning instead of a kernel panic. This option should only be used + for finding indirect call type mismatches during development. + + If unsure, say N. + config HAVE_ARCH_WITHIN_STACK_FRAMES bool help |