2023-08-04 11:25:19

by Tomi Valkeinen

Subject: [PATCH 2/2] drm/framebuffer: Fix use of uninitialized variable

smatch reports:

drivers/gpu/drm/drm_framebuffer.c:654 drm_mode_getfb2_ioctl() error: uninitialized symbol 'ret'.

'ret' is possibly not set when there are no errors, causing the error
above. I can't say if that ever happens in real-life, but in any case I
think it is good to initialize 'ret' to 0.

Signed-off-by: Tomi Valkeinen <[email protected]>
---
drivers/gpu/drm/drm_framebuffer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
index aff3746dedfb..1955eaeba0ab 100644
--- a/drivers/gpu/drm/drm_framebuffer.c
+++ b/drivers/gpu/drm/drm_framebuffer.c
@@ -570,7 +570,7 @@ int drm_mode_getfb2_ioctl(struct drm_device *dev,
struct drm_mode_fb_cmd2 *r = data;
struct drm_framebuffer *fb;
unsigned int i;
- int ret;
+ int ret = 0;

if (!drm_core_check_feature(dev, DRIVER_MODESET))
return -EINVAL;

--
2.34.1

2023-08-04 14:30:47

by Laurent Pinchart

Subject: Re: [PATCH 2/2] drm/framebuffer: Fix use of uninitialized variable

On Fri, Aug 04, 2023 at 01:57:40PM +0300, Tomi Valkeinen wrote:
> smatch reports:
>
> drivers/gpu/drm/drm_framebuffer.c:654 drm_mode_getfb2_ioctl() error: uninitialized symbol 'ret'.
>
> 'ret' is possibly not set when there are no errors, causing the error
> above. I can't say if that ever happens in real-life, but in any case I
> think it is good to initialize 'ret' to 0.

I don't think it can happen in practice, but tools have no way to know
that.

Reviewed-by: Laurent Pinchart <[email protected]>

> Signed-off-by: Tomi Valkeinen <[email protected]>
> ---
> drivers/gpu/drm/drm_framebuffer.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index aff3746dedfb..1955eaeba0ab 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -570,7 +570,7 @@ int drm_mode_getfb2_ioctl(struct drm_device *dev,
> struct drm_mode_fb_cmd2 *r = data;
> struct drm_framebuffer *fb;
> unsigned int i;
> - int ret;
> + int ret = 0;
>
> if (!drm_core_check_feature(dev, DRIVER_MODESET))
> return -EINVAL;
>

--
Regards,

Laurent Pinchart