Commit Graph

4 Commits

Author SHA1 Message Date
Peilin Ye 4ee573086b Fonts: Add charcount field to font_desc
Subsystems are hard-coding the number of characters of our built-in fonts
as 256. Include that information in our kernel font descriptor, `struct
font_desc`.

Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/65952296d1d9486093bd955d1536f7dcd11112c6.1605169912.git.yepeilin.cs@gmail.com
2020-11-16 16:31:41 +01:00
Lee Jones 9522750c66 Fonts: Replace discarded const qualifier
Commit 6735b4632d ("Fonts: Support FONT_EXTRA_WORDS macros for built-in
fonts") introduced the following error when building rpc_defconfig (only
this build appears to be affected):

 `acorndata_8x8' referenced in section `.text' of arch/arm/boot/compressed/ll_char_wr.o:
    defined in discarded section `.data' of arch/arm/boot/compressed/font.o
 `acorndata_8x8' referenced in section `.data.rel.ro' of arch/arm/boot/compressed/font.o:
    defined in discarded section `.data' of arch/arm/boot/compressed/font.o
 make[3]: *** [/scratch/linux/arch/arm/boot/compressed/Makefile:191: arch/arm/boot/compressed/vmlinux] Error 1
 make[2]: *** [/scratch/linux/arch/arm/boot/Makefile:61: arch/arm/boot/compressed/vmlinux] Error 2
 make[1]: *** [/scratch/linux/arch/arm/Makefile:317: zImage] Error 2

The .data section is discarded at link time.  Reinstating acorndata_8x8 as
const ensures it is still available after linking.  Do the same for the
other 12 built-in fonts as well, for consistency purposes.

Cc: <stable@vger.kernel.org>
Cc: Russell King <linux@armlinux.org.uk>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: 6735b4632d ("Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts")
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Co-developed-by: Peilin Ye <yepeilin.cs@gmail.com>
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20201102183242.2031659-1-yepeilin.cs@gmail.com
2020-11-03 10:51:34 +01:00
Peilin Ye 6735b4632d Fonts: Support FONT_EXTRA_WORDS macros for built-in fonts
syzbot has reported an issue in the framebuffer layer, where a malicious
user may overflow our built-in font data buffers.

In order to perform a reliable range check, subsystems need to know
`FONTDATAMAX` for each built-in font. Unfortunately, our font descriptor,
`struct console_font` does not contain `FONTDATAMAX`, and is part of the
UAPI, making it infeasible to modify it.

For user-provided fonts, the framebuffer layer resolves this issue by
reserving four extra words at the beginning of data buffers. Later,
whenever a function needs to access them, it simply uses the following
macros:

Recently we have gathered all the above macros to <linux/font.h>. Let us
do the same thing for built-in fonts, prepend four extra words (including
`FONTDATAMAX`) to their data buffers, so that subsystems can use these
macros for all fonts, no matter built-in or user-provided.

This patch depends on patch "fbdev, newport_con: Move FONT_EXTRA_WORDS
macros into linux/font.h".

Cc: stable@vger.kernel.org
Link: https://syzkaller.appspot.com/bug?id=08b8be45afea11888776f897895aef9ad1c3ecfd
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/ef18af00c35fb3cc826048a5f70924ed6ddce95b.1600953813.git.yepeilin.cs@gmail.com
2020-09-25 10:28:51 +02:00
Geert Uytterhoeven ee89bd6bc7 lib: Move fonts from drivers/video/console/ to lib/fonts/
Several drivers need font support independent of CONFIG_VT, cfr. commit
9cbce8d7e1dae0744ca4f68d62aa7de18196b6f4, "console/font: Refactor font
support code selection logic").
Hence move the fonts and their support logic from drivers/video/console/ to
its own library directory lib/fonts/.
This also allows to limit processing of drivers/video/console/Makefile to
CONFIG_VT=y again.

[Kevin Hilman <khilman@linaro.org>: Update arch/arm/boot/compressed/Makefile]
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
2013-06-28 10:28:22 +02:00