Re: small dmesg regression in kernel 4.17.3

From: Andy Shevchenko
Date: Wed Jun 27 2018 - 13:28:42 EST


+Cc: Erik

On Tue, Jun 26, 2018 at 8:57 PM, Toralf FÃrster <toralf.foerster@xxxxxx> wrote:
> The attached dmesg contains non printable chars 0x01 33 around "ACPI BIOS Error (bug): Could not resolve" which is a new issue compared to the dmesg of 4.17.2
>
> System is a stable hardened Gentoo Linux at a ThinkPad T440s.

I bet the below commit makes this.

commit 2e78935d1e27d31955ad2dad4abe6c453cf669fd
Author: Erik Schmauss <erik.schmauss@xxxxxxxxx>
Date: Fri Jun 1 12:06:43 2018 -0700

ACPICA: AML parser: attempt to continue loading table after error


So, it does add leading '\n' which flushes buffers followed by
printing the message you see. But, I'm guessing now, kernel adds a
default level since it's going to dmesg which you can see as
unprintable symbols.
Personally I'm not a fan of leading '\n':s since it brings more pain
than fixing something. It has special meaning (flushing buffers) and
many developers forget this.

--
With Best Regards,
Andy Shevchenko