Nouveau - Jan 2023 - [RESEND][PATCH] drm/nouveau/fb/ga102: Replace zero-length array of trailing structs with flex-array

On Tue, Jan 03, 2023 at 03:48:36PM -0800, Kees Cook
wrote:
> Zero-length arrays are deprecated[1] and are being replaced with
> flexible array members in support of the ongoing efforts to tighten the
> FORTIFY_SOURCE routines on memcpy(), correctly instrument array indexing
> with UBSAN_BOUNDS, and to globally enable -fstrict-flex-arrays=3.
> 
> Replace zero-length array with flexible-array member.
> 
> This results in no differences in binary output.
> 
> [1] https://github.com/KSPP/linux/issues/78
> 
> Cc: Ben Skeggs <bskeggs at redhat.com>
> Cc: Karol Herbst <kherbst at redhat.com>
> Cc: Lyude Paul <lyude at redhat.com>
> Cc: David Airlie <airlied at gmail.com>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: Gourav Samaiya <gsamaiya at nvidia.com>
> Cc: "Gustavo A. R. Silva" <gustavoars at kernel.org>
> Cc: dri-devel at lists.freedesktop.org
> Cc: nouveau at lists.freedesktop.org
> Signed-off-by: Kees Cook <keescook at chromium.org>
Here is my RB again:

Reviewed-by: Gustavo A. R. Silva <gustavoars at kernel.org>

Thanks!
--
Gustavo
> ---
> Sent before as: https://lore.kernel.org/all/20221118211207.never.039-kees
at kernel.org/
> ---
>  drivers/gpu/drm/nouveau/include/nvfw/hs.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/include/nvfw/hs.h
b/drivers/gpu/drm/nouveau/include/nvfw/hs.h
> index 8c4cd08a7b5f..8b58b668fc0c 100644
> --- a/drivers/gpu/drm/nouveau/include/nvfw/hs.h
> +++ b/drivers/gpu/drm/nouveau/include/nvfw/hs.h
> @@ -52,7 +52,7 @@ struct nvfw_hs_load_header_v2 {
>  	struct {
>  		u32 offset;
>  		u32 size;
> -	} app[0];
> +	} app[];
>  };
>  
>  const struct nvfw_hs_load_header_v2 *nvfw_hs_load_header_v2(struct
nvkm_subdev *, const void *);
> -- 
> 2.34.1
>

On Wed, Jan 4, 2023 at 1:52 AM Gustavo A. R. Silva
<gustavoars at kernel.org> wrote:
>
> On Tue, Jan 03, 2023 at 03:48:36PM -0800, Kees Cook wrote:
> > Zero-length arrays are deprecated[1] and are being replaced with
> > flexible array members in support of the ongoing efforts to tighten
the
> > FORTIFY_SOURCE routines on memcpy(), correctly instrument array
indexing
> > with UBSAN_BOUNDS, and to globally enable -fstrict-flex-arrays=3.
> >
> > Replace zero-length array with flexible-array member.
> >
> > This results in no differences in binary output.
> >
> > [1] https://github.com/KSPP/linux/issues/78
> >
> > Cc: Ben Skeggs <bskeggs at redhat.com>
> > Cc: Karol Herbst <kherbst at redhat.com>
> > Cc: Lyude Paul <lyude at redhat.com>
> > Cc: David Airlie <airlied at gmail.com>
> > Cc: Daniel Vetter <daniel at ffwll.ch>
> > Cc: Gourav Samaiya <gsamaiya at nvidia.com>
> > Cc: "Gustavo A. R. Silva" <gustavoars at kernel.org>
> > Cc: dri-devel at lists.freedesktop.org
> > Cc: nouveau at lists.freedesktop.org
> > Signed-off-by: Kees Cook <keescook at chromium.org>
>
> Here is my RB again:
>
> Reviewed-by: Gustavo A. R. Silva <gustavoars at kernel.org>
>
Reviewed-by: Karol Herbst <kherbst at redhat.com>

will push in a moment
> Thanks!
> --
> Gustavo
>
> > ---
> > Sent before as:
https://lore.kernel.org/all/20221118211207.never.039-kees at kernel.org/
> > ---
> >  drivers/gpu/drm/nouveau/include/nvfw/hs.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/nouveau/include/nvfw/hs.h
b/drivers/gpu/drm/nouveau/include/nvfw/hs.h
> > index 8c4cd08a7b5f..8b58b668fc0c 100644
> > --- a/drivers/gpu/drm/nouveau/include/nvfw/hs.h
> > +++ b/drivers/gpu/drm/nouveau/include/nvfw/hs.h
> > @@ -52,7 +52,7 @@ struct nvfw_hs_load_header_v2 {
> >       struct {
> >               u32 offset;
> >               u32 size;
> > -     } app[0];
> > +     } app[];
> >  };
> >
> >  const struct nvfw_hs_load_header_v2 *nvfw_hs_load_header_v2(struct
nvkm_subdev *, const void *);
> > --
> > 2.34.1
> >
>

Hi! Sorry for the late response, I've had my head buried in some regressions
from AMD for a while now and am now just catching up on my email.

Does this still need to be pushed upstream?

On Tue, 2023-01-03 at 18:52 -0600, Gustavo A. R. Silva
wrote:
> On Tue, Jan 03, 2023 at 03:48:36PM -0800, Kees Cook wrote:
> > Zero-length arrays are deprecated[1] and are being replaced with
> > flexible array members in support of the ongoing efforts to tighten
the
> > FORTIFY_SOURCE routines on memcpy(), correctly instrument array
indexing
> > with UBSAN_BOUNDS, and to globally enable -fstrict-flex-arrays=3.
> > 
> > Replace zero-length array with flexible-array member.
> > 
> > This results in no differences in binary output.
> > 
> > [1] https://github.com/KSPP/linux/issues/78
> > 
> > Cc: Ben Skeggs <bskeggs at redhat.com>
> > Cc: Karol Herbst <kherbst at redhat.com>
> > Cc: Lyude Paul <lyude at redhat.com>
> > Cc: David Airlie <airlied at gmail.com>
> > Cc: Daniel Vetter <daniel at ffwll.ch>
> > Cc: Gourav Samaiya <gsamaiya at nvidia.com>
> > Cc: "Gustavo A. R. Silva" <gustavoars at kernel.org>
> > Cc: dri-devel at lists.freedesktop.org
> > Cc: nouveau at lists.freedesktop.org
> > Signed-off-by: Kees Cook <keescook at chromium.org>
> 
> Here is my RB again:
> 
> Reviewed-by: Gustavo A. R. Silva <gustavoars at kernel.org>
> 
> Thanks!
> --
> Gustavo
> 
> > ---
> > Sent before as:
https://lore.kernel.org/all/20221118211207.never.039-kees at kernel.org/
> > ---
> >  drivers/gpu/drm/nouveau/include/nvfw/hs.h | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/nouveau/include/nvfw/hs.h
b/drivers/gpu/drm/nouveau/include/nvfw/hs.h
> > index 8c4cd08a7b5f..8b58b668fc0c 100644
> > --- a/drivers/gpu/drm/nouveau/include/nvfw/hs.h
> > +++ b/drivers/gpu/drm/nouveau/include/nvfw/hs.h
> > @@ -52,7 +52,7 @@ struct nvfw_hs_load_header_v2 {
> >  	struct {
> >  		u32 offset;
> >  		u32 size;
> > -	} app[0];
> > +	} app[];
> >  };
> >  
> >  const struct nvfw_hs_load_header_v2 *nvfw_hs_load_header_v2(struct
nvkm_subdev *, const void *);
> > -- 
> > 2.34.1
> > 
> 
-- 
Cheers,
 Lyude Paul (she/her)
 Software Engineer at Red Hat