2023-06-21 13:20:44

by Alexandre Mergnat

[permalink] [raw]
Subject: Re: [PATCH v3 3/4] drm/mediatek: Add casting before assign



On 21/06/2023 12:22, Jason-JH.Lin wrote:
> 1. Add casting before assign to avoid the unintentional integer
> overflow or unintended sign extension.
> 2. Add a int varriable for multiplier calculation instead of calculating
> different types multiplier with dma_addr_t varriable directly.
>
> Fixes: 1a64a7aff8da ("drm/mediatek: Fix cursor plane no update")
> Signed-off-by: Jason-JH.Lin <[email protected]>
> ---
> drivers/gpu/drm/mediatek/mtk_drm_gem.c | 3 ++-
> drivers/gpu/drm/mediatek/mtk_drm_plane.c | 22 +++++++++++++---------
> 2 files changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> index a25b28d3ee90..da087d74612d 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> @@ -121,7 +121,8 @@ int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
> int ret;
>
> args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
> - args->size = args->pitch * args->height;
> + args->size = args->pitch;
> + args->size *= args->height;
>
> mtk_gem = mtk_drm_gem_create(dev, args->size, false);
> if (IS_ERR(mtk_gem))
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> index 31f9420aff6f..1cd41454d545 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> @@ -145,6 +145,7 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
> dma_addr_t addr;
> dma_addr_t hdr_addr = 0;
> unsigned int hdr_pitch = 0;
> + int offset;

I agree with Angelo, please set offset as unsigned.

>
> gem = fb->obj[0];
> mtk_gem = to_mtk_gem_obj(gem);
> @@ -154,8 +155,10 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
> modifier = fb->modifier;
>
> if (modifier == DRM_FORMAT_MOD_LINEAR) {
> - addr += (new_state->src.x1 >> 16) * fb->format->cpp[0];
> - addr += (new_state->src.y1 >> 16) * pitch;
> + offset = (new_state->src.x1 >> 16) * fb->format->cpp[0];
> + addr += offset;
> + offset = (new_state->src.y1 >> 16) * pitch;
> + addr += offset;
> } else {
> int width_in_blocks = ALIGN(fb->width, AFBC_DATA_BLOCK_WIDTH)
> / AFBC_DATA_BLOCK_WIDTH;
> @@ -163,21 +166,22 @@ static void mtk_plane_update_new_state(struct drm_plane_state *new_state,
> / AFBC_DATA_BLOCK_HEIGHT;
> int x_offset_in_blocks = (new_state->src.x1 >> 16) / AFBC_DATA_BLOCK_WIDTH;
> int y_offset_in_blocks = (new_state->src.y1 >> 16) / AFBC_DATA_BLOCK_HEIGHT;
> - int hdr_size;
> + int hdr_size, hdr_offset;
>
> hdr_pitch = width_in_blocks * AFBC_HEADER_BLOCK_SIZE;
> pitch = width_in_blocks * AFBC_DATA_BLOCK_WIDTH *
> AFBC_DATA_BLOCK_HEIGHT * fb->format->cpp[0];
>
> hdr_size = ALIGN(hdr_pitch * height_in_blocks, AFBC_HEADER_ALIGNMENT);
> + hdr_offset = hdr_pitch * y_offset_in_blocks +
> + AFBC_HEADER_BLOCK_SIZE * x_offset_in_blocks;
> + hdr_addr = addr + hdr_offset;
>
> - hdr_addr = addr + hdr_pitch * y_offset_in_blocks +
> - AFBC_HEADER_BLOCK_SIZE * x_offset_in_blocks;
> /* The data plane is offset by 1 additional block. */
> - addr = addr + hdr_size +
> - pitch * y_offset_in_blocks +
> - AFBC_DATA_BLOCK_WIDTH * AFBC_DATA_BLOCK_HEIGHT *
> - fb->format->cpp[0] * (x_offset_in_blocks + 1);
> + offset = pitch * y_offset_in_blocks +
> + AFBC_DATA_BLOCK_WIDTH * AFBC_DATA_BLOCK_HEIGHT *
> + fb->format->cpp[0] * (x_offset_in_blocks + 1);
> + addr = addr + hdr_size + offset;
> }
>
> mtk_plane_state->pending.enable = true;

--
Regards,
Alexandre


2023-06-22 08:15:27

by Jason-JH.Lin

[permalink] [raw]
Subject: Re: [PATCH v3 3/4] drm/mediatek: Add casting before assign

Hi Alexandre,

Thanks for the reviews.

On Wed, 2023-06-21 at 14:34 +0200, Alexandre Mergnat wrote:
>
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>
>
> On 21/06/2023 12:22, Jason-JH.Lin wrote:
> > 1. Add casting before assign to avoid the unintentional integer
> > overflow or unintended sign extension.
> > 2. Add a int varriable for multiplier calculation instead of
> calculating
> > different types multiplier with dma_addr_t varriable directly.
> >
> > Fixes: 1a64a7aff8da ("drm/mediatek: Fix cursor plane no update")
> > Signed-off-by: Jason-JH.Lin <[email protected]>
> > ---
> > drivers/gpu/drm/mediatek/mtk_drm_gem.c | 3 ++-
> > drivers/gpu/drm/mediatek/mtk_drm_plane.c | 22 +++++++++++++----
> -----
> > 2 files changed, 15 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> > index a25b28d3ee90..da087d74612d 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> > @@ -121,7 +121,8 @@ int mtk_drm_gem_dumb_create(struct drm_file
> *file_priv, struct drm_device *dev,
> > int ret;
> >
> > args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
> > -args->size = args->pitch * args->height;
> > +args->size = args->pitch;
> > +args->size *= args->height;
> >
> > mtk_gem = mtk_drm_gem_create(dev, args->size, false);
> > if (IS_ERR(mtk_gem))
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> > index 31f9420aff6f..1cd41454d545 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
> > @@ -145,6 +145,7 @@ static void mtk_plane_update_new_state(struct
> drm_plane_state *new_state,
> > dma_addr_t addr;
> > dma_addr_t hdr_addr = 0;
> > unsigned int hdr_pitch = 0;
> > +int offset;
>
> I agree with Angelo, please set offset as unsigned.
>
I think offset should be unsigned, but since src.x1 and src.y1 are
'int'. That means 'unsigned int' offset will be very big when src.x1 or
src.y1 is negative.
So I just use 'int' for offset here.

Regards,
Jason-JH.Lin

> >
> > gem = fb->obj[0];
> > mtk_gem = to_mtk_gem_obj(gem);
> > @@ -154,8 +155,10 @@ static void mtk_plane_update_new_state(struct
> drm_plane_state *new_state,
> > modifier = fb->modifier;
> >
> > if (modifier == DRM_FORMAT_MOD_LINEAR) {
> > -addr += (new_state->src.x1 >> 16) * fb->format->cpp[0];
> > -addr += (new_state->src.y1 >> 16) * pitch;
> > +offset = (new_state->src.x1 >> 16) * fb->format->cpp[0];
> > +addr += offset;
> > +offset = (new_state->src.y1 >> 16) * pitch;
> > +addr += offset;
>

2023-07-12 13:27:02

by Alexandre Mergnat

[permalink] [raw]
Subject: Re: [PATCH v3 3/4] drm/mediatek: Add casting before assign



On 22/06/2023 10:02, Jason-JH Lin (林睿祥) wrote:
>> drm_plane_state *new_state,
>> > dma_addr_t addr;
>> > dma_addr_t hdr_addr = 0;
>> > unsigned int hdr_pitch = 0;
>> > +int offset;
>>
>> I agree with Angelo, please set offset as unsigned.
>>
> I think offset should be unsigned, but since src.x1 and src.y1 are
> 'int'. That means 'unsigned int' offset will be very big when src.x1 or
> src.y1 is negative.
> So I just use 'int' for offset here.

Ok

Reviewed-by: Alexandre Mergnat <[email protected]>

--
Regards,
Alexandre