[PATCH 2/5] Fonts: Make font size unsigned in font_desc

[PATCH 2/5] Fonts: Make font size unsigned in font_desc

[Peilin Ye]

It is improper to define `width` and `height` as signed in `struct
font_desc`. Make them unsigned. Also, change the corresponding printk()
format identifiers from `%d` to `%u`, in sti_select_fbfont().

Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
---
Build-tested.

 drivers/video/console/sticore.c | 2 +-
 include/linux/font.h            | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/console/sticore.c b/drivers/video/console/sticore.c
index 6a26a364f9bd..d1bb5915082b 100644
--- a/drivers/video/console/sticore.c
+++ b/drivers/video/console/sticore.c
@@ -502,7 +502,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
 	if (!fbfont)
 		return NULL;
 
-	pr_info("STI selected %dx%d framebuffer font %s for sticon\n",
+	pr_info("STI selected %ux%u framebuffer font %s for sticon\n",
 			fbfont->width, fbfont->height, fbfont->name);
 			
 	bpc = ((fbfont->width+7)/8) * fbfont->height; 
diff --git a/include/linux/font.h b/include/linux/font.h
index b5b312c19e46..4f50d736ea72 100644
--- a/include/linux/font.h
+++ b/include/linux/font.h
@@ -16,7 +16,7 @@
 struct font_desc {
     int idx;
     const char *name;
-    int width, height;
+    unsigned int width, height;
     const void *data;
     int pref;
 };
-- 
2.25.1

[PATCH 5/5] parisc/sticore: Avoid hard-coding built-in font charcount

[Peilin Ye]

sti_select_fbfont() and sti_cook_fonts() are hard-coding the number of
characters of our built-in fonts as 256. Recently, we included that
information in our kernel font descriptor `struct font_desc`, so use
`fbfont->charcount` instead of hard-coded values.

This patch depends on patch "Fonts: Add charcount field to font_desc".

Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
---
$ # Build-tested (Ubuntu 20.04)
$ sudo apt-get install binutils-hppa64-linux-gnu gcc-7-hppa64-linux-gnu
$ cp arch/parisc/configs/generic-64bit_defconfig .config
$ make -j`nproc` ARCH=parisc CROSS_COMPILE=hppa64-linux-gnu- all

 drivers/video/console/sticore.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/video/console/sticore.c b/drivers/video/console/sticore.c
index d1bb5915082b..f869b723494f 100644
--- a/drivers/video/console/sticore.c
+++ b/drivers/video/console/sticore.c
@@ -506,7 +506,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
 			fbfont->width, fbfont->height, fbfont->name);
 			
 	bpc = ((fbfont->width+7)/8) * fbfont->height; 
-	size = bpc * 256;
+	size = bpc * fbfont->charcount;
 	size += sizeof(struct sti_rom_font);
 
 	nf = kzalloc(size, STI_LOWMEM);
@@ -514,7 +514,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
 		return NULL;
 
 	nf->first_char = 0;
-	nf->last_char = 255;
+	nf->last_char = fbfont->charcount - 1;
 	nf->width = fbfont->width;
 	nf->height = fbfont->height;
 	nf->font_type = STI_FONT_HPROMAN8;
@@ -525,7 +525,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
 
 	dest = nf;
 	dest += sizeof(struct sti_rom_font);
-	memcpy(dest, fbfont->data, bpc*256);
+	memcpy(dest, fbfont->data, bpc * fbfont->charcount);
 
 	cooked_font = kzalloc(sizeof(*cooked_font), GFP_KERNEL);
 	if (!cooked_font) {
@@ -660,7 +660,7 @@ static int sti_cook_fonts(struct sti_cooked_rom *cooked_rom,
 void sti_font_convert_bytemode(struct sti_struct *sti, struct sti_cooked_font *f)
 {
 	unsigned char *n, *p, *q;
-	int size = f->raw->bytes_per_char * 256 + sizeof(struct sti_rom_font);
+	int size = f->raw->bytes_per_char * (f->raw->last_char + 1) + sizeof(struct sti_rom_font);
 	struct sti_rom_font *old_font;
 
 	if (sti->wordmode)
-- 
2.25.1

Re: [PATCH 2/5] Fonts: Make font size unsigned in font_desc

[Daniel Vetter]

On Tue, Oct 27, 2020 at 12:33:05PM -0400, Peilin Ye wrote:
> It is improper to define `width` and `height` as signed in `struct
> font_desc`. Make them unsigned. Also, change the corresponding printk()
> format identifiers from `%d` to `%u`, in sti_select_fbfont().
> 
> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>

I'm not entirely sure of the motivation here ... height/width should never
ever be even close to the limit here. Or have you seen integer math that
could potentially go wrong if we go with unsigned instead of int?
-Daniel

> ---
> Build-tested.
> 
>  drivers/video/console/sticore.c | 2 +-
>  include/linux/font.h            | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/video/console/sticore.c b/drivers/video/console/sticore.c
> index 6a26a364f9bd..d1bb5915082b 100644
> --- a/drivers/video/console/sticore.c
> +++ b/drivers/video/console/sticore.c
> @@ -502,7 +502,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
>  	if (!fbfont)
>  		return NULL;
>  
> -	pr_info("STI selected %dx%d framebuffer font %s for sticon\n",
> +	pr_info("STI selected %ux%u framebuffer font %s for sticon\n",
>  			fbfont->width, fbfont->height, fbfont->name);
>  			
>  	bpc = ((fbfont->width+7)/8) * fbfont->height; 
> diff --git a/include/linux/font.h b/include/linux/font.h
> index b5b312c19e46..4f50d736ea72 100644
> --- a/include/linux/font.h
> +++ b/include/linux/font.h
> @@ -16,7 +16,7 @@
>  struct font_desc {
>      int idx;
>      const char *name;
> -    int width, height;
> +    unsigned int width, height;
>      const void *data;
>      int pref;
>  };
> -- 
> 2.25.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH 5/5] parisc/sticore: Avoid hard-coding built-in font charcount

[Daniel Vetter]

On Tue, Oct 27, 2020 at 12:41:02PM -0400, Peilin Ye wrote:
> sti_select_fbfont() and sti_cook_fonts() are hard-coding the number of
> characters of our built-in fonts as 256. Recently, we included that
> information in our kernel font descriptor `struct font_desc`, so use
> `fbfont->charcount` instead of hard-coded values.
> 
> This patch depends on patch "Fonts: Add charcount field to font_desc".
> 
> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> ---
> $ # Build-tested (Ubuntu 20.04)
> $ sudo apt-get install binutils-hppa64-linux-gnu gcc-7-hppa64-linux-gnu
> $ cp arch/parisc/configs/generic-64bit_defconfig .config
> $ make -j`nproc` ARCH=parisc CROSS_COMPILE=hppa64-linux-gnu- all
> 
>  drivers/video/console/sticore.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/video/console/sticore.c b/drivers/video/console/sticore.c
> index d1bb5915082b..f869b723494f 100644
> --- a/drivers/video/console/sticore.c
> +++ b/drivers/video/console/sticore.c
> @@ -506,7 +506,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
>  			fbfont->width, fbfont->height, fbfont->name);
>  			
>  	bpc = ((fbfont->width+7)/8) * fbfont->height; 
> -	size = bpc * 256;
> +	size = bpc * fbfont->charcount;
>  	size += sizeof(struct sti_rom_font);
>  
>  	nf = kzalloc(size, STI_LOWMEM);
> @@ -514,7 +514,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
>  		return NULL;
>  
>  	nf->first_char = 0;
> -	nf->last_char = 255;
> +	nf->last_char = fbfont->charcount - 1;
>  	nf->width = fbfont->width;
>  	nf->height = fbfont->height;
>  	nf->font_type = STI_FONT_HPROMAN8;
> @@ -525,7 +525,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
>  
>  	dest = nf;
>  	dest += sizeof(struct sti_rom_font);
> -	memcpy(dest, fbfont->data, bpc*256);
> +	memcpy(dest, fbfont->data, bpc * fbfont->charcount);
>  
>  	cooked_font = kzalloc(sizeof(*cooked_font), GFP_KERNEL);
>  	if (!cooked_font) {
> @@ -660,7 +660,7 @@ static int sti_cook_fonts(struct sti_cooked_rom *cooked_rom,
>  void sti_font_convert_bytemode(struct sti_struct *sti, struct sti_cooked_font *f)
>  {
>  	unsigned char *n, *p, *q;
> -	int size = f->raw->bytes_per_char * 256 + sizeof(struct sti_rom_font);
> +	int size = f->raw->bytes_per_char * (f->raw->last_char + 1) + sizeof(struct sti_rom_font);
>  	struct sti_rom_font *old_font;
>  
>  	if (sti->wordmode)
> -- 
> 2.25.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH 2/5] Fonts: Make font size unsigned in font_desc

[Peilin Ye]

On Tue, Oct 27, 2020 at 07:50:58PM +0100, Daniel Vetter wrote:
> On Tue, Oct 27, 2020 at 12:33:05PM -0400, Peilin Ye wrote:
> > It is improper to define `width` and `height` as signed in `struct
> > font_desc`. Make them unsigned. Also, change the corresponding printk()
> > format identifiers from `%d` to `%u`, in sti_select_fbfont().
> > 
> > Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
> 
> I'm not entirely sure of the motivation here ... height/width should never
> ever be even close to the limit here. Or have you seen integer math that
> could potentially go wrong if we go with unsigned instead of int?

Oh... No, I have not. I just thought we shouldn't represent a length
using a signed value. Also, width and height in console_font are
unsigned int - that shouldn't matter that much though.

[3/5] doesn't hunk properly without this patch, I'll send a v2 for [3/5]
soon.

Peilin

Re: [PATCH 2/5] Fonts: Make font size unsigned in font_desc

[Daniel Vetter]

On Wed, Oct 28, 2020 at 01:43:07AM -0400, Peilin Ye wrote:
> On Tue, Oct 27, 2020 at 07:50:58PM +0100, Daniel Vetter wrote:
> > On Tue, Oct 27, 2020 at 12:33:05PM -0400, Peilin Ye wrote:
> > > It is improper to define `width` and `height` as signed in `struct
> > > font_desc`. Make them unsigned. Also, change the corresponding printk()
> > > format identifiers from `%d` to `%u`, in sti_select_fbfont().
> > > 
> > > Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
> > 
> > I'm not entirely sure of the motivation here ... height/width should never
> > ever be even close to the limit here. Or have you seen integer math that
> > could potentially go wrong if we go with unsigned instead of int?
> 
> Oh... No, I have not. I just thought we shouldn't represent a length
> using a signed value. Also, width and height in console_font are
> unsigned int - that shouldn't matter that much though.

Oh this is actually a good reason, since that's the uapi structure. And so
using the exact same signedness should help a bit with accidental casting
bugs.

If you mention this in the commit message I think this is good to go.
-Daniel

> 
> [3/5] doesn't hunk properly without this patch, I'll send a v2 for [3/5]
> soon.
> 
> Peilin
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

Re: [PATCH 2/5] Fonts: Make font size unsigned in font_desc

[Peilin Ye]

On Wed, Oct 28, 2020 at 09:18:44AM +0100, Daniel Vetter wrote:
> On Wed, Oct 28, 2020 at 01:43:07AM -0400, Peilin Ye wrote:
> > On Tue, Oct 27, 2020 at 07:50:58PM +0100, Daniel Vetter wrote:
> > > On Tue, Oct 27, 2020 at 12:33:05PM -0400, Peilin Ye wrote:
> > > > It is improper to define `width` and `height` as signed in `struct
> > > > font_desc`. Make them unsigned. Also, change the corresponding printk()
> > > > format identifiers from `%d` to `%u`, in sti_select_fbfont().
> > > > 
> > > > Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
> > > 
> > > I'm not entirely sure of the motivation here ... height/width should never
> > > ever be even close to the limit here. Or have you seen integer math that
> > > could potentially go wrong if we go with unsigned instead of int?
> > 
> > Oh... No, I have not. I just thought we shouldn't represent a length
> > using a signed value. Also, width and height in console_font are
> > unsigned int - that shouldn't matter that much though.
> 
> Oh this is actually a good reason, since that's the uapi structure. And so
> using the exact same signedness should help a bit with accidental casting
> bugs.
> 
> If you mention this in the commit message I think this is good to go.

Ah, I see, v2 on the way. Please ignore [v2 3/5], that doesn't hunk with
this patch in effect...

One newbie question, should I mention in the commit message, if a patch
depends on another patch in the series in order to hunk properly?

Peilin

[PATCH v2 2/5] Fonts: Make font size unsigned in font_desc

[Peilin Ye]

`width` and `height` are defined as unsigned in our UAPI font descriptor
`struct console_font`. Make them unsigned in our kernel font descriptor
`struct font_desc`, too.

Also, change the corresponding printk() format identifiers from `%d` to
`%u`, in sti_select_fbfont().

Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
---
Change in v2:
  - Mention `struct console_font` in the commit message. (Suggested by
    Daniel Vetter <daniel@ffwll.ch>)

 drivers/video/console/sticore.c | 2 +-
 include/linux/font.h            | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/video/console/sticore.c b/drivers/video/console/sticore.c
index 6a26a364f9bd..d1bb5915082b 100644
--- a/drivers/video/console/sticore.c
+++ b/drivers/video/console/sticore.c
@@ -502,7 +502,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
 	if (!fbfont)
 		return NULL;
 
-	pr_info("STI selected %dx%d framebuffer font %s for sticon\n",
+	pr_info("STI selected %ux%u framebuffer font %s for sticon\n",
 			fbfont->width, fbfont->height, fbfont->name);
 			
 	bpc = ((fbfont->width+7)/8) * fbfont->height; 
diff --git a/include/linux/font.h b/include/linux/font.h
index b5b312c19e46..4f50d736ea72 100644
--- a/include/linux/font.h
+++ b/include/linux/font.h
@@ -16,7 +16,7 @@
 struct font_desc {
     int idx;
     const char *name;
-    int width, height;
+    unsigned int width, height;
     const void *data;
     int pref;
 };
-- 
2.25.1

Re: [PATCH v2 2/5] Fonts: Make font size unsigned in font_desc

[Daniel Vetter]

On Wed, Oct 28, 2020 at 06:56:47AM -0400, Peilin Ye wrote:
> `width` and `height` are defined as unsigned in our UAPI font descriptor
> `struct console_font`. Make them unsigned in our kernel font descriptor
> `struct font_desc`, too.
> 
> Also, change the corresponding printk() format identifiers from `%d` to
> `%u`, in sti_select_fbfont().
> 
> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>

Pushed to drm-misc-next, thanks for the patch.
-Daniel

> ---
> Change in v2:
>   - Mention `struct console_font` in the commit message. (Suggested by
>     Daniel Vetter <daniel@ffwll.ch>)
> 
>  drivers/video/console/sticore.c | 2 +-
>  include/linux/font.h            | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/video/console/sticore.c b/drivers/video/console/sticore.c
> index 6a26a364f9bd..d1bb5915082b 100644
> --- a/drivers/video/console/sticore.c
> +++ b/drivers/video/console/sticore.c
> @@ -502,7 +502,7 @@ sti_select_fbfont(struct sti_cooked_rom *cooked_rom, const char *fbfont_name)
>  	if (!fbfont)
>  		return NULL;
>  
> -	pr_info("STI selected %dx%d framebuffer font %s for sticon\n",
> +	pr_info("STI selected %ux%u framebuffer font %s for sticon\n",
>  			fbfont->width, fbfont->height, fbfont->name);
>  			
>  	bpc = ((fbfont->width+7)/8) * fbfont->height; 
> diff --git a/include/linux/font.h b/include/linux/font.h
> index b5b312c19e46..4f50d736ea72 100644
> --- a/include/linux/font.h
> +++ b/include/linux/font.h
> @@ -16,7 +16,7 @@
>  struct font_desc {
>      int idx;
>      const char *name;
> -    int width, height;
> +    unsigned int width, height;
>      const void *data;
>      int pref;
>  };
> -- 
> 2.25.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch