From 36799069b48198e5ce92d99310060c4aecb4b3e3 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Fri, 14 Mar 2025 12:29:11 -0700 Subject: [PATCH] objtool: Add CONFIG_OBJTOOL_WERROR Objtool warnings can be indicative of crashes, broken live patching, or even boot failures. Ignoring them is not recommended. Add CONFIG_OBJTOOL_WERROR to upgrade objtool warnings to errors by enabling the objtool --Werror option. Also set --backtrace to print the branches leading up to the warning, which can help considerably when debugging certain warnings. To avoid breaking bots too badly for now, make it the default for real world builds only (!COMPILE_TEST). Co-developed-by: Brendan Jackman Signed-off-by: Josh Poimboeuf Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/3e7c109313ff15da6c80788965cc7450115b0196.1741975349.git.jpoimboe@kernel.org --- lib/Kconfig.debug | 11 +++++++++++ scripts/Makefile.lib | 1 + 2 files changed, 12 insertions(+) diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 35796c290ca3..a9709a6db30f 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -545,6 +545,17 @@ config FRAME_POINTER config OBJTOOL bool +config OBJTOOL_WERROR + bool "Upgrade objtool warnings to errors" + depends on OBJTOOL && !COMPILE_TEST + help + Fail the build on objtool warnings. + + Objtool warnings can indicate kernel instability, including boot + failures. This option is highly recommended. + + If unsure, say Y. + config STACK_VALIDATION bool "Compile-time stack metadata validation" depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib index cad20f0e66ee..99e281966ba3 100644 --- a/scripts/Makefile.lib +++ b/scripts/Makefile.lib @@ -277,6 +277,7 @@ objtool-args-$(CONFIG_HAVE_STATIC_CALL_INLINE) += --static-call objtool-args-$(CONFIG_HAVE_UACCESS_VALIDATION) += --uaccess objtool-args-$(CONFIG_GCOV_KERNEL) += --no-unreachable objtool-args-$(CONFIG_PREFIX_SYMBOLS) += --prefix=$(CONFIG_FUNCTION_PADDING_BYTES) +objtool-args-$(CONFIG_OBJTOOL_WERROR) += --Werror --backtrace objtool-args = $(objtool-args-y) \ $(if $(delay-objtool), --link) \ -- 2.25.1