lkml.org 
[lkml]   [2018]   [Nov]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 11/11] efi/x86: earlyprintk - Fix infinite loop on some screen widths

* Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:

> From: YiFei Zhu <zhuyifei1999@gmail.com>
>
> An affected screen resolution is 1366 x 768, which width is not
> divisible by 8, the default font width. On such screens, when longer
> lines are earlyprintk'ed, overflow-to-next-line can never trigger,
> due to the left-most x-coordinate of the next character always less
> than the screen width. Earlyprintk will infinite loop in trying to
> print the rest of the string but unable to, due to the line being
> full.
>
> This patch makes the trigger consider the right-most x-coordinate,
> instead of left-most, as the value to compare against the screen
> width threshold.
>
> Signed-off-by: YiFei Zhu <zhuyifei1999@gmail.com>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> ---
> arch/x86/platform/efi/early_printk.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/platform/efi/early_printk.c b/arch/x86/platform/efi/early_printk.c
> index 7476b3b097e1..7138bc7a265c 100644
> --- a/arch/x86/platform/efi/early_printk.c
> +++ b/arch/x86/platform/efi/early_printk.c
> @@ -183,7 +183,7 @@ early_efi_write(struct console *con, const char *str, unsigned int num)
> num--;
> }
>
> - if (efi_x >= si->lfb_width) {
> + if (efi_x + font->width > si->lfb_width) {
> efi_x = 0;
> efi_y += font->height;
> }

Any objections to marking this for -stable and queueing it up in
efi/urgent as well?

Thanks,

Ingo

\
 
 \ /
  Last update: 2018-11-30 09:06    [W:0.229 / U:12.436 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site