From dde5cf39d4d2cce71f2997c37210dd624d0e4bf6 Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Tue, 22 Mar 2016 14:27:45 -0700 Subject: [PATCH] ubsan: fix tree-wide -Wmaybe-uninitialized false positives -fsanitize=* options makes GCC less smart than usual and increase number of 'maybe-uninitialized' false-positives. So this patch does two things: * Add -Wno-maybe-uninitialized to CFLAGS_UBSAN which will disable all such warnings for instrumented files. * Remove CONFIG_UBSAN_SANITIZE_ALL from all[yes|mod]config builds. So the all[yes|mod]config build goes without -fsanitize=* and still with -Wmaybe-uninitialized. Signed-off-by: Andrey Ryabinin Reported-by: Fengguang Wu Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.ubsan | 5 +++++ scripts/Makefile.ubsan | 4 ++++ 2 files changed, 9 insertions(+) diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index e07c1ba9ba13..39494af9a84a 100644 --- a/lib/Kconfig.ubsan +++ b/lib/Kconfig.ubsan @@ -13,6 +13,11 @@ config UBSAN_SANITIZE_ALL bool "Enable instrumentation for the entire kernel" depends on UBSAN depends on ARCH_HAS_UBSAN_SANITIZE_ALL + + # We build with -Wno-maybe-uninitilzed, but we still want to + # use -Wmaybe-uninitilized in allmodconfig builds. + # So dependsy bellow used to disable this option in allmodconfig + depends on !COMPILE_TEST default y help This option activates instrumentation for the entire kernel. diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan index 8ab68679cfb5..77ce538268b5 100644 --- a/scripts/Makefile.ubsan +++ b/scripts/Makefile.ubsan @@ -14,4 +14,8 @@ ifdef CONFIG_UBSAN ifdef CONFIG_UBSAN_ALIGNMENT CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment) endif + + # -fsanitize=* options makes GCC less smart than usual and + # increase number of 'maybe-uninitialized false-positives + CFLAGS_UBSAN += $(call cc-option, -Wno-maybe-uninitialized) endif -- 2.20.1