Daniel Axtens e48fc8880d video/fb/fbfill: Use unsigned integers for width/height ...

Since commit 7ce3259f67 (video/fb/fbfill: Fix potential integer
overflow), clang builds of grub-emu have failed with messages like:

  /usr/bin/ld: libgrubmods.a(libgrubmods_a-fbfill.o): in function `grub_video_fbfill_direct24':
  fbfill.c:(.text+0x28e): undefined reference to `__muloti4'

This appears to be due to a weird quirk in how clang compiles

  grub_mul(dst->mode_info->bytes_per_pixel, width, &rowskip)

which is grub_mul(unsigned int, int, &grub_size_t).

It looks like clang somewhere promotes everything to 128-bit maths
before ultimately reducing down to 64 bit for grub_size_t. I think
this is because width is signed, and indeed converting width to an
unsigned int makes the problem go away.

This conversion also makes more sense generally:
  - the caller of all the fbfill_directN functions is
    grub_video_fb_fill_dispatch() and it takes width and height as
    unsigned ints already,
  - it doesn't make sense to fill a negative width or height.

Convert the width and height arguments and associated loop counters
to unsigned ints.

Fixes: 7ce3259f67 (video/fb/fbfill: Fix potential integer overflow)

Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>

2021-04-12 16:56:45 +02:00

..

fbblit.c

fbblit: Optimize by replacing division with additions and shifts.

2015-02-26 18:14:28 +01:00

fbfill.c

video/fb/fbfill: Use unsigned integers for width/height

2021-04-12 16:56:45 +02:00

fbutil.c

Detach optional parts of gfxterm and integrate in with coreboot init.

2013-05-31 00:42:33 +02:00

video_fb.c

video/fb/video_fb: Fix possible integer overflow

2021-03-02 15:54:17 +01:00