[PATCH 0/9] enabled -Wformat-truncation for clang

[PATCH 0/9] enabled -Wformat-truncation for clang

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

With randconfig build testing, I found only eight files that produce
warnings with clang when -Wformat-truncation is enabled. This means
we can just turn it on by default rather than only enabling it for
"make W=1".

Unfortunately, gcc produces a lot more warnings when the option
is enabled, so it's not yet possible to turn it on both both
compilers.

I hope that the patches can get picked up by platform maintainers
directly, so the final patch can go in later on.

     Arnd

Arnd Bergmann (9):
  fbdev: shmobile: fix snprintf truncation
  enetc: avoid truncating error message
  qed: avoid truncating work queue length
  mlx5: avoid truncating error message
  surface3_power: avoid format string truncation warning
  Input: IMS: fix printf string overflow
  scsi: mylex: fix sysfs buffer lengths
  ALSA: aoa: avoid false-positive format truncation warning
  kbuild: enable -Wformat-truncation on clang

 drivers/input/misc/ims-pcu.c                  |  4 ++--
 drivers/net/ethernet/freescale/enetc/enetc.c  |  2 +-
 .../ethernet/mellanox/mlx5/core/esw/bridge.c  |  2 +-
 drivers/net/ethernet/qlogic/qed/qed_main.c    |  9 ++++---
 drivers/platform/surface/surface3_power.c     |  2 +-
 drivers/scsi/myrb.c                           | 20 ++++++++--------
 drivers/scsi/myrs.c                           | 24 +++++++++----------
 drivers/video/fbdev/sh_mobile_lcdcfb.c        |  2 +-
 scripts/Makefile.extrawarn                    |  2 ++
 sound/aoa/soundbus/i2sbus/core.c              |  2 +-
 10 files changed, 35 insertions(+), 34 deletions(-)

-- 
2.39.2

Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Claudiu Manoil <claudiu.manoil@nxp.com>
Cc: Vladimir Oltean <vladimir.oltean@nxp.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Saeed Mahameed <saeedm@nvidia.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Ariel Elior <aelior@marvell.com>
Cc: Manish Chopra <manishc@marvell.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
Cc: Maximilian Luz <luzmaximilian@gmail.com>
Cc: Hannes Reinecke <hare@kernel.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Cc: platform-driver-x86@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kbuild@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: alsa-devel@alsa-project.org
Cc: linux-sound@vger.kernel.org
Cc: llvm@lists.linux.dev

[PATCH 9/9] kbuild: enable -Wformat-truncation on clang

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

This warning option still produces output on gcc but is now clean when
building with clang, so enable it conditionally on the compiler for now.

As far as I can tell, the remaining warnings with gcc are the result of
analysing the code more deeply across inlining, while clang only does
this within a function.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 scripts/Makefile.extrawarn | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index bff6c686df7c..aa1c716c4812 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -99,7 +99,9 @@ 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)
+ifdef CONFIG_CC_IS_GCC
 KBUILD_CFLAGS += $(call cc-disable-warning, format-truncation)
+endif
 KBUILD_CFLAGS += $(call cc-disable-warning, stringop-truncation)
 
 KBUILD_CFLAGS += -Wno-override-init # alias for -Wno-initializer-overrides in clang
-- 
2.39.2

Re: [PATCH 0/9] enabled -Wformat-truncation for clang

[Jakub Kicinski]

On Tue, 26 Mar 2024 23:37:59 +0100 Arnd Bergmann wrote:
> I hope that the patches can get picked up by platform maintainers
> directly, so the final patch can go in later on.

platform == subsystem? :)

Re: [PATCH 0/9] enabled -Wformat-truncation for clang

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue, 26 Mar 2024 23:37:59 +0100 you wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> With randconfig build testing, I found only eight files that produce
> warnings with clang when -Wformat-truncation is enabled. This means
> we can just turn it on by default rather than only enabling it for
> "make W=1".
> 
> [...]

Here is the summary with links:
  - [2/9] enetc: avoid truncating error message
    https://git.kernel.org/netdev/net-next/c/9046d581ed58
  - [3/9] qed: avoid truncating work queue length
    https://git.kernel.org/netdev/net-next/c/954fd908f177
  - [4/9] mlx5: avoid truncating error message
    https://git.kernel.org/netdev/net-next/c/b324a960354b

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: (subset) [PATCH 0/9] enabled -Wformat-truncation for clang

[Martin K. Petersen]

On Tue, 26 Mar 2024 23:37:59 +0100, Arnd Bergmann wrote:

> With randconfig build testing, I found only eight files that produce
> warnings with clang when -Wformat-truncation is enabled. This means
> we can just turn it on by default rather than only enabling it for
> "make W=1".
> 
> Unfortunately, gcc produces a lot more warnings when the option
> is enabled, so it's not yet possible to turn it on both both
> compilers.
> 
> [...]

Applied to 6.9/scsi-fixes, thanks!

[7/9] scsi: mylex: fix sysfs buffer lengths
      https://git.kernel.org/mkp/scsi/c/1197c5b2099f

-- 
Martin K. Petersen	Oracle Linux Engineering