Nouveau - May 2024 - [PATCH 1/4] drm/amdgpu: fix -Wformat-truncation warning in amdgpu_gfx_kiq_init_ring()

Enabling -Wformat-truncation yields the following warning:

../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c: In function
?amdgpu_gfx_kiq_init_ring?:
../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:61: error: ?%d? directive output
may be truncated writing between 1 and 10 bytes into a region of size between 0
and 8 [-Werror=format-truncation=]
  332 |         snprintf(ring->name, sizeof(ring->name),
"kiq_%d.%d.%d.%d",
      |                                                             ^~
../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:50: note: directive argument in
the range [0, 2147483647]
  332 |         snprintf(ring->name, sizeof(ring->name),
"kiq_%d.%d.%d.%d",
      |                                                  ^~~~~~~~~~~~~~~~~
../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:9: note: ?snprintf? output
between 12 and 41 bytes into a destination of size 16
  332 |         snprintf(ring->name, sizeof(ring->name),
"kiq_%d.%d.%d.%d",
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  333 |                  xcc_id, ring->me, ring->pipe, ring->queue);
      |                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Silence the warning by checking the snprintf() return value.

Signed-off-by: Jani Nikula <jani.nikula at intel.com>

---

Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: "Christian K?nig" <christian.koenig at amd.com>
Cc: Pan Xinhui <Xinhui.Pan at amd.com>
Cc: amd-gfx at lists.freedesktop.org
Cc: dri-devel at lists.freedesktop.org
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
index 1d955652f3ba..92744d0d2c10 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
@@ -329,8 +329,10 @@ int amdgpu_gfx_kiq_init_ring(struct amdgpu_device *adev,
int xcc_id)
 
 	ring->eop_gpu_addr = kiq->eop_gpu_addr;
 	ring->no_scheduler = true;
-	snprintf(ring->name, sizeof(ring->name), "kiq_%d.%d.%d.%d",
-		 xcc_id, ring->me, ring->pipe, ring->queue);
+	r = snprintf(ring->name, sizeof(ring->name),
"kiq_%d.%d.%d.%d",
+		     xcc_id, ring->me, ring->pipe, ring->queue);
+	if (r >= sizeof(ring->name))
+		dev_warn(adev->dev, "kiq ring name truncated\n");
 	r = amdgpu_ring_init(adev, ring, 1024, irq, AMDGPU_CP_KIQ_IRQ_DRIVER0,
 			     AMDGPU_RING_PRIO_DEFAULT, NULL);
 	if (r)
-- 
2.39.2

On Thu, May 23, 2024 at 11:51?AM Jani Nikula <jani.nikula at intel.com>
wrote:
>
> Enabling -Wformat-truncation yields the following warning:
>
> ../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c: In function
?amdgpu_gfx_kiq_init_ring?:
> ../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:61: error: ?%d? directive
output may be truncated writing between 1 and 10 bytes into a region of size
between 0 and 8 [-Werror=format-truncation=]
>   332 |         snprintf(ring->name, sizeof(ring->name),
"kiq_%d.%d.%d.%d",
>       |                                                             ^~
> ../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:50: note: directive argument
in the range [0, 2147483647]
>   332 |         snprintf(ring->name, sizeof(ring->name),
"kiq_%d.%d.%d.%d",
>       |                                                  ^~~~~~~~~~~~~~~~~
> ../drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c:332:9: note: ?snprintf? output
between 12 and 41 bytes into a destination of size 16
>   332 |         snprintf(ring->name, sizeof(ring->name),
"kiq_%d.%d.%d.%d",
>       |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>   333 |                  xcc_id, ring->me, ring->pipe,
ring->queue);
>       |                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> Silence the warning by checking the snprintf() return value.
>
Already fixed with this patch:
https://patchwork.freedesktop.org/patch/594864/

Thanks,

Alex
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
>
> ---
>
> Cc: Alex Deucher <alexander.deucher at amd.com>
> Cc: "Christian K?nig" <christian.koenig at amd.com>
> Cc: Pan Xinhui <Xinhui.Pan at amd.com>
> Cc: amd-gfx at lists.freedesktop.org
> Cc: dri-devel at lists.freedesktop.org
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> index 1d955652f3ba..92744d0d2c10 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gfx.c
> @@ -329,8 +329,10 @@ int amdgpu_gfx_kiq_init_ring(struct amdgpu_device
*adev, int xcc_id)
>
>         ring->eop_gpu_addr = kiq->eop_gpu_addr;
>         ring->no_scheduler = true;
> -       snprintf(ring->name, sizeof(ring->name),
"kiq_%d.%d.%d.%d",
> -                xcc_id, ring->me, ring->pipe, ring->queue);
> +       r = snprintf(ring->name, sizeof(ring->name),
"kiq_%d.%d.%d.%d",
> +                    xcc_id, ring->me, ring->pipe, ring->queue);
> +       if (r >= sizeof(ring->name))
> +               dev_warn(adev->dev, "kiq ring name
truncated\n");
>         r = amdgpu_ring_init(adev, ring, 1024, irq,
AMDGPU_CP_KIQ_IRQ_DRIVER0,
>                              AMDGPU_RING_PRIO_DEFAULT, NULL);
>         if (r)
> --
> 2.39.2
>