• YiFei Zhu's avatar
    x86/earlyprintk/efi: Fix infinite loop on some screen widths · 79c2206d
    YiFei Zhu authored
    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: default avatarYiFei Zhu <zhuyifei1999@gmail.com>
    Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
    Cc: Andy Lutomirski <luto@kernel.org>
    Cc: Arend van Spriel <arend.vanspriel@broadcom.com>
    Cc: Bhupesh Sharma <bhsharma@redhat.com>
    Cc: Borislav Petkov <bp@alien8.de>
    Cc: Dave Hansen <dave.hansen@intel.com>
    Cc: Eric Snowberg <eric.snowberg@oracle.com>
    Cc: Hans de Goede <hdegoede@redhat.com>
    Cc: Joe Perches <joe@perches.com>
    Cc: Jon Hunter <jonathanh@nvidia.com>
    Cc: Julien Thierry <julien.thierry@arm.com>
    Cc: Linus Torvalds <torvalds@linux-foundation.org>
    Cc: Marc Zyngier <marc.zyngier@arm.com>
    Cc: Matt Fleming <matt@codeblueprint.co.uk>
    Cc: Nathan Chancellor <natechancellor@gmail.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
    Cc: Sedat Dilek <sedat.dilek@gmail.com>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    Cc: linux-efi@vger.kernel.org
    Link: http://lkml.kernel.org/r/20181129171230.18699-12-ard.biesheuvel@linaro.orgSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
    79c2206d
early_printk.c 4.96 KB