From: Kees Cook <keescook@chromium.org>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Ard Biesheuvel <ardb@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Masahiro Yamada <masahiroy@kernel.org>,
Michal Marek <michal.lkml@markovi.net>,
Nathan Chancellor <natechancellor@gmail.com>,
Nick Desaulniers <ndesaulniers@google.com>,
Marco Elver <elver@google.com>,
Randy Dunlap <rdunlap@infradead.org>,
Dmitry Vyukov <dvyukov@google.com>,
George Popescu <georgepope@android.com>,
Herbert Xu <herbert@gondor.apana.org.au>,
Peter Oberparleiter <oberpar@linux.ibm.com>,
Andrey Ryabinin <aryabinin@virtuozzo.com>,
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 [thread overview]
Message-ID: <20201002221527.177500-4-keescook@chromium.org> (raw)
In-Reply-To: <20201002221527.177500-1-keescook@chromium.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 <keescook@chromium.org>
---
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
--
2.25.1
next prev parent reply other threads:[~2020-10-02 22:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-02 22:15 [PATCH 0/4] Clean up UBSAN Makefile Kees Cook
2020-10-02 22:15 ` [PATCH 1/4] ubsan: Move cc-option tests into Kconfig Kees Cook
2020-10-04 7:08 ` Nathan Chancellor
2020-10-06 6:01 ` Kees Cook
2020-10-02 22:15 ` [PATCH 2/4] ubsan: Disable object-size sanitizer under GCC Kees Cook
2020-10-04 7:10 ` Nathan Chancellor
2020-10-02 22:15 ` Kees Cook [this message]
2020-10-04 7:16 ` [PATCH 3/4] ubsan: Force -Wno-maybe-uninitialized only for GCC Nathan Chancellor
2020-10-06 6:03 ` Kees Cook
2020-10-02 22:15 ` [PATCH 4/4] ubsan: Disable UBSAN_TRAP for all*config Kees Cook
2020-10-04 7:16 ` Nathan Chancellor
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