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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id fz22sm2557221pjb.46.2020.10.02.15.15.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 02 Oct 2020 15:15:29 -0700 (PDT) From: Kees Cook To: Andrew Morton Cc: Kees Cook , Linus Torvalds , Ard Biesheuvel , Arnd Bergmann , Masahiro Yamada , Michal Marek , Nathan Chancellor , Nick Desaulniers , Marco Elver , Randy Dunlap , Dmitry Vyukov , George Popescu , Herbert Xu , Peter Oberparleiter , Andrey Ryabinin , clang-built-linux@googlegroups.com, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/4] ubsan: Force -Wno-maybe-uninitialized only for GCC Date: Fri, 2 Oct 2020 15:15:26 -0700 Message-Id: <20201002221527.177500-4-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20201002221527.177500-1-keescook@chromium.org> References: <20201002221527.177500-1-keescook@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kbuild@vger.kernel.org Clang handles 'maybe-uninitialized' better in the face of using UBSAN, so do not make this universally disabled for UBSAN builds. Signed-off-by: Kees Cook --- lib/Kconfig.ubsan | 6 ++++++ scripts/Makefile.ubsan | 6 +++--- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index aeb2cdea0b94..1fc07f936e06 100644 --- a/lib/Kconfig.ubsan +++ b/lib/Kconfig.ubsan @@ -36,6 +36,12 @@ config UBSAN_KCOV_BROKEN See https://bugs.llvm.org/show_bug.cgi?id=45831 for the status in newer releases. +config UBSAN_DISABLE_MAYBE_UNINITIALIZED + def_bool CC_IS_GCC + help + -fsanitize=* options makes GCC less smart than usual and + increases the number of 'maybe-uninitialized' false-positives. + config CC_HAS_UBSAN_BOUNDS def_bool $(cc-option,-fsanitize=bounds) diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan index 72862da47baf..c5ef6bac09d4 100644 --- a/scripts/Makefile.ubsan +++ b/scripts/Makefile.ubsan @@ -1,8 +1,8 @@ # SPDX-License-Identifier: GPL-2.0 -# -fsanitize=* options makes GCC less smart than usual and -# increases the number of 'maybe-uninitialized' false-positives. -ubsan-cflags-$(CONFIG_UBSAN) += $(call cc-disable-warning, maybe-uninitialized) +# The "maybe-uninitialized" warning can be very noisy. +ubsan-cflags-$(CONFIG_UBSAN_DISABLE_MAYBE_UNINITIALIZED) += \ + $(call cc-disable-warning, maybe-uninitialized) # Enable available and selected UBSAN features. ubsan-cflags-$(CONFIG_UBSAN_ALIGNMENT) += -fsanitize=alignment