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[15/20] drm/tegra/hub: Increase buffer size to ensure all possible values can be stored

Message ID 20230824073710.2677348-16-lee@kernel.org
State New
Headers
Series Rid W=1 warnings from GPU |

Commit Message

Lee Jones Aug. 24, 2023, 7:37 a.m. UTC 
  When converting from int to string, we must allow for up to 10-chars (2147483647).

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/tegra/hub.c: In function ‘tegra_display_hub_probe’:
 drivers/gpu/drm/tegra/hub.c:1106:47: warning: ‘%u’ directive output may be truncated writing between 1 and 10 bytes into a region of size 4 [-Wformat-truncation=]
 drivers/gpu/drm/tegra/hub.c:1106:42: note: directive argument in the range [0, 4294967294]
 drivers/gpu/drm/tegra/hub.c:1106:17: note: ‘snprintf’ output between 6 and 15 bytes into a destination of size 8

Signed-off-by: Lee Jones <lee@kernel.org>
---
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Mikko Perttunen <mperttunen@nvidia.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-tegra@vger.kernel.org
---
 drivers/gpu/drm/tegra/hub.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Lee Jones Aug. 24, 2023, 12:01 p.m. UTC | #1 
On Thu, 24 Aug 2023, Jani Nikula wrote:

> On Thu, 24 Aug 2023, Thierry Reding <thierry.reding@gmail.com> wrote:
> > On Thu, Aug 24, 2023 at 08:37:00AM +0100, Lee Jones wrote:
> >> When converting from int to string, we must allow for up to 10-chars (2147483647).
> >> 
> >> Fixes the following W=1 kernel build warning(s):
> >> 
> >>  drivers/gpu/drm/tegra/hub.c: In function ‘tegra_display_hub_probe’:
> >>  drivers/gpu/drm/tegra/hub.c:1106:47: warning: ‘%u’ directive output may be truncated writing between 1 and 10 bytes into a region of size 4 [-Wformat-truncation=]
> >>  drivers/gpu/drm/tegra/hub.c:1106:42: note: directive argument in the range [0, 4294967294]
> >>  drivers/gpu/drm/tegra/hub.c:1106:17: note: ‘snprintf’ output between 6 and 15 bytes into a destination of size 8
> >
> > I wish there was (perhaps there is?) a better way to annotate that i
> > will always be within a given range. In practice this is always going to
> > be smaller than 10 and even in future hardware I wouldn't expect this to
> > ever exceed anything like 32 or 64, so 8 characters is already generous.
> 
> I assume you could do
> 
> 	snprintf(id, sizeof(id), "wgrp%u", (unsigned char)i);
> 
> but it's perhaps less obvious than just increasing the size of the
> buffer.

I had the very same thought process.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/tegra/hub.c b/drivers/gpu/drm/tegra/hub.c
index 1af5f8318d914..f21e57e8599ee 100644
--- a/drivers/gpu/drm/tegra/hub.c
+++ b/drivers/gpu/drm/tegra/hub.c
@@ -1101,7 +1101,7 @@  static int tegra_display_hub_probe(struct platform_device *pdev)
 
 	for (i = 0; i < hub->soc->num_wgrps; i++) {
 		struct tegra_windowgroup *wgrp = &hub->wgrps[i];
-		char id[8];
+		char id[16];
 
 		snprintf(id, sizeof(id), "wgrp%u", i);
 		mutex_init(&wgrp->lock);