Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a536093a authored by Antonino A. Daplas's avatar Antonino A. Daplas Committed by Linus Torvalds
Browse files

[PATCH] fbcon: Fix big-endian bogosity in slow_imageblit() 



The monochrome->color expansion routine that handles bitmaps which have
(widths % 8) != 0 (slow_imageblit) produces corrupt characters in big-endian.
This is caused by a bogus bit test in slow_imageblit().

Fix.

This patch may deserve to go to the stable tree.  The code has already been
well tested in little-endian machines.  It's only in big-endian where there is
uncertainty and Herbert confirmed that this is the correct way to go.

It should not introduce regressions.

Signed-off-by: default avatarAntonino Daplas <adaplas@pol.net>
Acked-by: default avatarHerbert Poetzl <herbert@13thfloor.at>
Cc: <stable@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 2cbbb3b5

drivers/video/cfbimgblt.c

+1 −1
Original line number Diff line number Diff line
@@ -169,7 +169,7 @@ static inline void slow_imageblit(const struct fb_image *image, struct fb_info * 


		while (j--) {

			l--;

			color = (*s & 1 << (FB_BIT_NR(l))) ? fgcolor : bgcolor;

			color = (*s & (1 << l)) ? fgcolor : bgcolor;

			val |= FB_SHIFT_HIGH(color, shift);

			

			/* Did the bitshift spill bits to the next long? */

include/linux/fb.h

+0 −2
Original line number Diff line number Diff line
@@ -839,12 +839,10 @@ struct fb_info { 
#define FB_LEFT_POS(bpp)          (32 - bpp)

#define FB_SHIFT_HIGH(val, bits)  ((val) >> (bits))

#define FB_SHIFT_LOW(val, bits)   ((val) << (bits))

#define FB_BIT_NR(b)              (7 - (b))

#else

#define FB_LEFT_POS(bpp)          (0)

#define FB_SHIFT_HIGH(val, bits)  ((val) << (bits))

#define FB_SHIFT_LOW(val, bits)   ((val) >> (bits))

#define FB_BIT_NR(b)              (b)

#endif



    /*