Re: drm/nvd0/disp: initial crtc object implementation

[Ben Skeggs <bskeggs@redhat.com>]

----- Original Message -----
> From: "Dan Carpenter" <dan.carpenter@oracle.com>
> To: bskeggs@redhat.com
> Cc: dri-devel@lists.freedesktop.org
> Sent: Wednesday, 27 November, 2013 7:30:27 AM
> Subject: re: drm/nvd0/disp: initial crtc object implementation
> 
> Hello Ben Skeggs,
> 
> The patch 438d99e3b175: "drm/nvd0/disp: initial crtc object
> implementation" from Jul 5, 2011, leads to the following
> static checker warning: "drivers/gpu/drm/nouveau/nv50_display.c:1272
> nv50_crtc_gamma_set()
> 	 error: buffer overflow 'nv_crtc->lut.r' 256 <= 256"
> 
> drivers/gpu/drm/nouveau/nv50_display.c
>   1263  static void
>   1264  nv50_crtc_gamma_set(struct drm_crtc *crtc, u16 *r, u16 *g, u16 *b,
>   1265                      uint32_t start, uint32_t size)
>   1266  {
>   1267          struct nouveau_crtc *nv_crtc = nouveau_crtc(crtc);
>   1268          u32 end = max(start + size, (u32)256);
>   1269          u32 i;
>   1270
>   1271          for (i = start; i < end; i++) {
>   1272                  nv_crtc->lut.r[i] = r[i];
>                                  ^^^^^^^^
> These arrays have 256 elements so going beyond seems like a bug.  Should
> the end = max() be a min() or something?
Yes, should definitely be a min.  Did you want to cook the patch or shall I?

Thanks,
Ben.

> 
>   1273                  nv_crtc->lut.g[i] = g[i];
>   1274                  nv_crtc->lut.b[i] = b[i];
>   1275          }
>   1276
>   1277          nv50_crtc_lut_load(crtc);
>   1278  }
> 
> regards,
> dan carpenter
> 
>