[PATCH v3 03/28] kbuild: Add CONFIG_OBJTOOL_CONTROL_FLOW
From: Josh Poimboeuf <jpoimboe@kernel.org>
Date: 2026-09-21 22:31:38
Also in:
lkml, rust-for-linux
Subsystem:
library code, the rest, ubsan · Maintainers:
Andrew Morton, Linus Torvalds, Kees Cook
Add a config option for when objtool reverse engineers the control flow graph of every function. No functional change. Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> --- lib/Kconfig.debug | 6 ++++++ lib/Kconfig.ubsan | 2 +- 2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 55732323dc16e..798a10ded19fd 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug@@ -577,6 +577,12 @@ config OBJTOOL_DEFERRED depends on OBJTOOL depends on LTO_CLANG || X86_KERNEL_IBT || KLP_BUILD +# Objtool reverse-engineers the control flow graph +config OBJTOOL_CONTROL_FLOW + def_bool y + depends on OBJTOOL + depends on UNWINDER_ORC || STACK_VALIDATION || HAVE_UACCESS_VALIDATION + config STACK_VALIDATION bool "Compile-time stack metadata validation" depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan
index 1ecaae7064d2a..61e8c86ef63be 100644
--- a/lib/Kconfig.ubsan
+++ b/lib/Kconfig.ubsan@@ -110,7 +110,7 @@ config UBSAN_UNREACHABLE bool "Perform checking for unreachable code" # objtool already handles unreachable checking and gets angry about # seeing UBSan instrumentation located in unreachable places. - depends on !(OBJTOOL && (STACK_VALIDATION || UNWINDER_ORC || HAVE_UACCESS_VALIDATION)) + depends on !OBJTOOL_CONTROL_FLOW depends on $(cc-option,-fsanitize=unreachable) help This option enables -fsanitize=unreachable which checks for control
--
2.55.0