[REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[Peter Rosin]

Blitting an image with "negative" offsets is not working since there
is no clipping. It hopefully just crashes. For the bootup logo, there
is protection so that blitting does not happen as the image is drawn
further and further to the right (ROTATE_UR) or further and further
down (ROTATE_CW). There is however no protection when drawing in the
opposite directions (ROTATE_UD and ROTATE_CCW).

Add back this protection.

The regression is 20-odd years old but the mindless warning-killing
mentality displayed in commit 34bdb666f4b2 ("fbdev: fbmem: remove
positive test on unsigned values") is also to blame, methinks.

Fixes: 448d479747b8 ("fbdev: fb_do_show_logo() updates")
Signed-off-by: Peter Rosin <peda@axentia.se>
---
 drivers/video/fbdev/core/fbmem.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index bb7f5f23e347..1abeb0b72455 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -435,7 +435,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
 			image->dx += image->width + 8;
 		}
 	} else if (rotate == FB_ROTATE_UD) {
-		for (x = 0; x < num; x++) {
+		u32 dx = image->dx;
+
+		for (x = 0; x < num && image->dx <= dx; x++) {
 			info->fbops->fb_imageblit(info, image);
 			image->dx -= image->width + 8;
 		}
@@ -447,7 +449,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
 			image->dy += image->height + 8;
 		}
 	} else if (rotate == FB_ROTATE_CCW) {
-		for (x = 0; x < num; x++) {
+		u32 dy = image->dy;
+
+		for (x = 0; x < num && image->dy <= dy; x++) {
 			info->fbops->fb_imageblit(info, image);
 			image->dy -= image->height + 8;
 		}
-- 
2.11.0

[REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[Peter Rosin]

Blitting an image with "negative" offsets is not working since there
is no clipping. It hopefully just crashes. For the bootup logo, there
is protection so that blitting does not happen as the image is drawn
further and further to the right (ROTATE_UR) or further and further
down (ROTATE_CW). There is however no protection when drawing in the
opposite directions (ROTATE_UD and ROTATE_CCW).

Add back this protection.

The regression is 20-odd years old but the mindless warning-killing
mentality displayed in commit 34bdb666f4b2 ("fbdev: fbmem: remove
positive test on unsigned values") is also to blame, methinks.

Fixes: 448d479747b8 ("fbdev: fb_do_show_logo() updates")
Signed-off-by: Peter Rosin <peda@axentia.se>
---
 drivers/video/fbdev/core/fbmem.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index bb7f5f23e347..1abeb0b72455 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -435,7 +435,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
 			image->dx += image->width + 8;
 		}
 	} else if (rotate == FB_ROTATE_UD) {
-		for (x = 0; x < num; x++) {
+		u32 dx = image->dx;
+
+		for (x = 0; x < num && image->dx <= dx; x++) {
 			info->fbops->fb_imageblit(info, image);
 			image->dx -= image->width + 8;
 		}
@@ -447,7 +449,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
 			image->dy += image->height + 8;
 		}
 	} else if (rotate == FB_ROTATE_CCW) {
-		for (x = 0; x < num; x++) {
+		u32 dy = image->dy;
+
+		for (x = 0; x < num && image->dy <= dy; x++) {
 			info->fbops->fb_imageblit(info, image);
 			image->dy -= image->height + 8;
 		}
-- 
2.11.0

Re: [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[Peter Rosin]

Ping?!

Cheers,
Peter

On 2018-11-08 10:54, Peter Rosin wrote:
> Blitting an image with "negative" offsets is not working since there
> is no clipping. It hopefully just crashes. For the bootup logo, there
> is protection so that blitting does not happen as the image is drawn
> further and further to the right (ROTATE_UR) or further and further
> down (ROTATE_CW). There is however no protection when drawing in the
> opposite directions (ROTATE_UD and ROTATE_CCW).
> 
> Add back this protection.
> 
> The regression is 20-odd years old but the mindless warning-killing
> mentality displayed in commit 34bdb666f4b2 ("fbdev: fbmem: remove
> positive test on unsigned values") is also to blame, methinks.
> 
> Fixes: 448d479747b8 ("fbdev: fb_do_show_logo() updates")
> Signed-off-by: Peter Rosin <peda@axentia.se>
> ---
>  drivers/video/fbdev/core/fbmem.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
> index bb7f5f23e347..1abeb0b72455 100644
> --- a/drivers/video/fbdev/core/fbmem.c
> +++ b/drivers/video/fbdev/core/fbmem.c
> @@ -435,7 +435,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
>  			image->dx += image->width + 8;
>  		}
>  	} else if (rotate == FB_ROTATE_UD) {
> -		for (x = 0; x < num; x++) {
> +		u32 dx = image->dx;
> +
> +		for (x = 0; x < num && image->dx <= dx; x++) {
>  			info->fbops->fb_imageblit(info, image);
>  			image->dx -= image->width + 8;
>  		}
> @@ -447,7 +449,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
>  			image->dy += image->height + 8;
>  		}
>  	} else if (rotate == FB_ROTATE_CCW) {
> -		for (x = 0; x < num; x++) {
> +		u32 dy = image->dy;
> +
> +		for (x = 0; x < num && image->dy <= dy; x++) {
>  			info->fbops->fb_imageblit(info, image);
>  			image->dy -= image->height + 8;
>  		}
> 

Re: [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[Peter Rosin]
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Re: [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[Bartlomiej Zolnierkiewicz]

On 11/26/2018 03:16 PM, Peter Rosin wrote:
> Ping?!

Hi,

Thank you for your patch, it will be considered for 4.21 (as it is not
a recent regression + I'm busy with other things currently).

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

> Cheers,
> Peter
> 
> On 2018-11-08 10:54, Peter Rosin wrote:
>> Blitting an image with "negative" offsets is not working since there
>> is no clipping. It hopefully just crashes. For the bootup logo, there
>> is protection so that blitting does not happen as the image is drawn
>> further and further to the right (ROTATE_UR) or further and further
>> down (ROTATE_CW). There is however no protection when drawing in the
>> opposite directions (ROTATE_UD and ROTATE_CCW).
>>
>> Add back this protection.
>>
>> The regression is 20-odd years old but the mindless warning-killing
>> mentality displayed in commit 34bdb666f4b2 ("fbdev: fbmem: remove
>> positive test on unsigned values") is also to blame, methinks.
>>
>> Fixes: 448d479747b8 ("fbdev: fb_do_show_logo() updates")
>> Signed-off-by: Peter Rosin <peda@axentia.se>
>> ---
>>  drivers/video/fbdev/core/fbmem.c | 8 ++++++--
>>  1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
>> index bb7f5f23e347..1abeb0b72455 100644
>> --- a/drivers/video/fbdev/core/fbmem.c
>> +++ b/drivers/video/fbdev/core/fbmem.c
>> @@ -435,7 +435,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
>>  			image->dx += image->width + 8;
>>  		}
>>  	} else if (rotate == FB_ROTATE_UD) {
>> -		for (x = 0; x < num; x++) {
>> +		u32 dx = image->dx;
>> +
>> +		for (x = 0; x < num && image->dx <= dx; x++) {
>>  			info->fbops->fb_imageblit(info, image);
>>  			image->dx -= image->width + 8;
>>  		}
>> @@ -447,7 +449,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
>>  			image->dy += image->height + 8;
>>  		}
>>  	} else if (rotate == FB_ROTATE_CCW) {
>> -		for (x = 0; x < num; x++) {
>> +		u32 dy = image->dy;
>> +
>> +		for (x = 0; x < num && image->dy <= dy; x++) {
>>  			info->fbops->fb_imageblit(info, image);
>>  			image->dy -= image->height + 8;
>>  		}

Re: [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[Bartlomiej Zolnierkiewicz]

On 11/26/2018 03:16 PM, Peter Rosin wrote:
> Ping?!

Hi,

Thank you for your patch, it will be considered for 4.21 (as it is not
a recent regression + I'm busy with other things currently).

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

> Cheers,
> Peter
> 
> On 2018-11-08 10:54, Peter Rosin wrote:
>> Blitting an image with "negative" offsets is not working since there
>> is no clipping. It hopefully just crashes. For the bootup logo, there
>> is protection so that blitting does not happen as the image is drawn
>> further and further to the right (ROTATE_UR) or further and further
>> down (ROTATE_CW). There is however no protection when drawing in the
>> opposite directions (ROTATE_UD and ROTATE_CCW).
>>
>> Add back this protection.
>>
>> The regression is 20-odd years old but the mindless warning-killing
>> mentality displayed in commit 34bdb666f4b2 ("fbdev: fbmem: remove
>> positive test on unsigned values") is also to blame, methinks.
>>
>> Fixes: 448d479747b8 ("fbdev: fb_do_show_logo() updates")
>> Signed-off-by: Peter Rosin <peda@axentia.se>
>> ---
>>  drivers/video/fbdev/core/fbmem.c | 8 ++++++--
>>  1 file changed, 6 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
>> index bb7f5f23e347..1abeb0b72455 100644
>> --- a/drivers/video/fbdev/core/fbmem.c
>> +++ b/drivers/video/fbdev/core/fbmem.c
>> @@ -435,7 +435,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
>>  			image->dx += image->width + 8;
>>  		}
>>  	} else if (rotate = FB_ROTATE_UD) {
>> -		for (x = 0; x < num; x++) {
>> +		u32 dx = image->dx;
>> +
>> +		for (x = 0; x < num && image->dx <= dx; x++) {
>>  			info->fbops->fb_imageblit(info, image);
>>  			image->dx -= image->width + 8;
>>  		}
>> @@ -447,7 +449,9 @@ static void fb_do_show_logo(struct fb_info *info, struct fb_image *image,
>>  			image->dy += image->height + 8;
>>  		}
>>  	} else if (rotate = FB_ROTATE_CCW) {
>> -		for (x = 0; x < num; x++) {
>> +		u32 dy = image->dy;
>> +
>> +		for (x = 0; x < num && image->dy <= dy; x++) {
>>  			info->fbops->fb_imageblit(info, image);
>>  			image->dy -= image->height + 8;
>>  		}

Re: [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[Peter Rosin]

On 2018-11-26 15:33, Bartlomiej Zolnierkiewicz wrote:
> On 11/26/2018 03:16 PM, Peter Rosin wrote:
>> Ping?!
> 
> Hi,
> 
> Thank you for your patch, it will be considered for 4.21 (as it is not
> a recent regression + I'm busy with other things currently).

Right, thanks for letting me know!

Cheers,
Peter

Re: [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[Peter Rosin]

T24gMjAxOC0xMS0yNiAxNTozMywgQmFydGxvbWllaiBab2xuaWVya2lld2ljeiB3cm90ZToNCj4g
T24gMTEvMjYvMjAxOCAwMzoxNiBQTSwgUGV0ZXIgUm9zaW4gd3JvdGU6DQo+PiBQaW5nPyENCj4g
DQo+IEhpLA0KPiANCj4gVGhhbmsgeW91IGZvciB5b3VyIHBhdGNoLCBpdCB3aWxsIGJlIGNvbnNp
ZGVyZWQgZm9yIDQuMjEgKGFzIGl0IGlzIG5vdA0KPiBhIHJlY2VudCByZWdyZXNzaW9uICsgSSdt
IGJ1c3kgd2l0aCBvdGhlciB0aGluZ3MgY3VycmVudGx5KS4NCg0KUmlnaHQsIHRoYW5rcyBmb3Ig
bGV0dGluZyBtZSBrbm93IQ0KDQpDaGVlcnMsDQpQZXRlcg0K

Re: [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[Bartlomiej Zolnierkiewicz]

On 11/26/2018 10:19 PM, Peter Rosin wrote:
> On 2018-11-26 15:33, Bartlomiej Zolnierkiewicz wrote:
>> On 11/26/2018 03:16 PM, Peter Rosin wrote:
>>> Ping?!
>>
>> Hi,
>>
>> Thank you for your patch, it will be considered for 4.21 (as it is not
>> a recent regression + I'm busy with other things currently).
> 
> Right, thanks for letting me know!

Patch queued for 4.21, thanks.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

Re: [REGRESSION PATCH] fbdev: fbmem: behave better with small rotated displays and many CPUs

[Bartlomiej Zolnierkiewicz]

On 11/26/2018 10:19 PM, Peter Rosin wrote:
> On 2018-11-26 15:33, Bartlomiej Zolnierkiewicz wrote:
>> On 11/26/2018 03:16 PM, Peter Rosin wrote:
>>> Ping?!
>>
>> Hi,
>>
>> Thank you for your patch, it will be considered for 4.21 (as it is not
>> a recent regression + I'm busy with other things currently).
> 
> Right, thanks for letting me know!

Patch queued for 4.21, thanks.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics