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From: Arnd Bergmann <arnd@kernel.org>
To: Masahiro Yamada <masahiroy@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>,
	Nathan Chancellor <nathan@kernel.org>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Nicolas Schier <nicolas@fjasle.eu>,
	Guenter Roeck <linux@roeck-us.net>, Lee Jones <lee@kernel.org>,
	Stephen Rothwell <sfr@canb.auug.org.au>,
	linux-kbuild@vger.kernel.org, linux-arch@vger.kernel.org
Subject: [PATCH 5/9] extrawarn: enable format and stringop overflow warnings in W=1
Date: Fri, 11 Aug 2023 16:03:23 +0200	[thread overview]
Message-ID: <20230811140327.3754597-6-arnd@kernel.org> (raw)
In-Reply-To: <20230811140327.3754597-1-arnd@kernel.org>

From: Arnd Bergmann <arnd@arndb.de>

The stringop and format warnings got disabled globally when they were
newly introduced in commit bd664f6b3e376 ("disable new gcc-7.1.1 warnings
for now"), 217c3e0196758 ("disable stringop truncation warnings for now")
and 5a76021c2eff7 ("gcc-10: disable 'stringop-overflow' warning for now").

In all cases, the sentiment at the time was that the warnings are
useful, and we actually addressed a number of real bugs based on
them, but we never managed to eliminate them all because even the
build bots using W=1 builds only see the -Wstringop-truncation
warnings that are enabled at that level.

Move these into the W=1 section to give them a larger build coverage
and actually eliminate them over time.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 scripts/Makefile.extrawarn | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index 87bfe153198f1..ec528972371fa 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -16,8 +16,6 @@ KBUILD_CFLAGS += -Werror=strict-prototypes
 KBUILD_CFLAGS += -Wno-format-security
 KBUILD_CFLAGS += -Wno-trigraphs
 KBUILD_CFLAGS += $(call cc-disable-warning,frame-address,)
-KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
-KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
 KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)
 
 ifneq ($(CONFIG_FRAME_WARN),0)
@@ -56,9 +54,6 @@ KBUILD_CFLAGS += -Wno-pointer-sign
 # globally built with -Wcast-function-type.
 KBUILD_CFLAGS += $(call cc-option, -Wcast-function-type)
 
-# We'll want to enable this eventually, but it's not going away for 5.7 at least
-KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
-
 # Another good warning that we'll want to enable eventually
 KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
 
@@ -111,6 +106,9 @@ KBUILD_CFLAGS += -Wmissing-include-dirs
 KBUILD_CFLAGS += $(call cc-option, -Wunused-but-set-variable)
 KBUILD_CFLAGS += $(call cc-option, -Wunused-const-variable)
 KBUILD_CFLAGS += $(call cc-option, -Wpacked-not-aligned)
+KBUILD_CFLAGS += $(call cc-option, -Wformat-overflow)
+KBUILD_CFLAGS += $(call cc-option, -Wformat-truncation)
+KBUILD_CFLAGS += $(call cc-option, -Wstringop-overflow)
 KBUILD_CFLAGS += $(call cc-option, -Wstringop-truncation)
 
 KBUILD_CPPFLAGS += -Wundef
@@ -123,6 +121,9 @@ else
 KBUILD_CFLAGS += $(call cc-disable-warning, unused-but-set-variable)
 KBUILD_CFLAGS += $(call cc-disable-warning, unused-const-variable)
 KBUILD_CFLAGS += $(call cc-disable-warning, packed-not-aligned)
+KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow)
+KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
+KBUILD_CFLAGS += $(call cc-disable-warning, stringop-overflow)
 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
 
 ifdef CONFIG_CC_IS_CLANG
-- 
2.39.2


  parent reply	other threads:[~2023-08-11 14:03 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-08-11 14:03 [PATCH 0/9] Kbuild: warning options cleanup and more warnings Arnd Bergmann
2023-08-11 14:03 ` [PATCH 1/9] Kbuild: only pass -fno-inline-functions-called-once for gcc Arnd Bergmann
2023-08-11 14:14   ` Nathan Chancellor
2023-08-11 14:23     ` Arnd Bergmann
2023-08-11 14:03 ` [PATCH 2/9] Kbuild: consolidate warning flags in scripts/Makefile.extrawarn Arnd Bergmann
2023-08-11 14:19   ` Nathan Chancellor
2023-08-11 14:26     ` Arnd Bergmann
2023-08-12  7:21       ` Masahiro Yamada
2023-08-20  1:36       ` Masahiro Yamada
2023-08-11 14:03 ` [PATCH 3/9] Kbuild: avoid duplicate warning options Arnd Bergmann
2023-08-12  9:21   ` Masahiro Yamada
2023-08-12  9:28     ` Arnd Bergmann
2023-08-20  1:38       ` Masahiro Yamada
2023-08-11 14:03 ` [PATCH 4/9] extrawarn: don't turn off -Wshift-negative-value for gcc-9 Arnd Bergmann
2023-08-12 12:04   ` Masahiro Yamada
2023-08-11 14:03 ` Arnd Bergmann [this message]
2023-08-12 13:10   ` [PATCH 5/9] extrawarn: enable format and stringop overflow warnings in W=1 Masahiro Yamada
2023-08-20  1:40     ` Masahiro Yamada
2023-08-21 18:26     ` Nick Desaulniers
2023-08-11 14:03 ` [PATCH 6/9] extrawarn: move -Wrestrict into W=1 warnings Arnd Bergmann
2023-08-12 13:20   ` Masahiro Yamada
2023-08-20  1:45   ` Masahiro Yamada
2023-08-11 14:03 ` [PATCH 7/9] extrawarn: do not disable -Wmain at W=1 level Arnd Bergmann
2023-08-11 14:03 ` [PATCH 8/9] extrawarn: enable more warnings in W=2 Arnd Bergmann
2023-08-11 14:03 ` [PATCH 9/9] [RFC] extrawarn: enable more W=1 warnings by default Arnd Bergmann
2023-08-11 16:09   ` Nathan Chancellor
2023-08-11 18:23     ` Arnd Bergmann
2023-08-14 19:52       ` Nathan Chancellor

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