[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 8/9] ALSA: aoa: avoid false-positive format truncation warning

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

clang warns about what it interprets as a truncated snprintf:

sound/aoa/soundbus/i2sbus/core.c:171:6: error: 'snprintf' will always be truncated; specified size is 6, but format string expands to at least 7 [-Werror,-Wformat-truncation-non-kprintf]

The actual problem here is that it does not understand the special
%pOFn format string and assumes that it is a pointer followed by
the string "OFn", which would indeed not fit.

Slightly increasing the size of the buffer to its natural alignment
avoids the warning, as it is now long enough for the correct and
the incorrect interprations.

Fixes: b917d58dcfaa ("ALSA: aoa: Convert to using %pOFn instead of device_node.name")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 sound/aoa/soundbus/i2sbus/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/aoa/soundbus/i2sbus/core.c b/sound/aoa/soundbus/i2sbus/core.c
index b8ff5cccd0c8..5431d2c49421 100644
--- a/sound/aoa/soundbus/i2sbus/core.c
+++ b/sound/aoa/soundbus/i2sbus/core.c
@@ -158,7 +158,7 @@ static int i2sbus_add_dev(struct macio_dev *macio,
 	struct device_node *child, *sound = NULL;
 	struct resource *r;
 	int i, layout = 0, rlen, ok = force;
-	char node_name[6];
+	char node_name[8];
 	static const char *rnames[] = { "i2sbus: %pOFn (control)",
 					"i2sbus: %pOFn (tx)",
 					"i2sbus: %pOFn (rx)" };
-- 
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 8/9] ALSA: aoa: avoid false-positive format truncation warning

[Takashi Iwai]

On Tue, 26 Mar 2024 23:38:07 +0100,
Arnd Bergmann wrote:
> 
> From: Arnd Bergmann <arnd@arndb.de>
> 
> clang warns about what it interprets as a truncated snprintf:
> 
> sound/aoa/soundbus/i2sbus/core.c:171:6: error: 'snprintf' will always be truncated; specified size is 6, but format string expands to at least 7 [-Werror,-Wformat-truncation-non-kprintf]
> 
> The actual problem here is that it does not understand the special
> %pOFn format string and assumes that it is a pointer followed by
> the string "OFn", which would indeed not fit.
> 
> Slightly increasing the size of the buffer to its natural alignment
> avoids the warning, as it is now long enough for the correct and
> the incorrect interprations.
> 
> Fixes: b917d58dcfaa ("ALSA: aoa: Convert to using %pOFn instead of device_node.name")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Applied this one now to sound.git tree.  Thanks.


Takashi

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