Re: [PATCH] kunit: tool: Force the use of the 'tty' console for UML

From: Shuah Khan
Date: Tue Jan 05 2021 - 14:52:58 EST


On 1/5/21 11:57 AM, Andy Shevchenko wrote:
On Tue, Jan 05, 2021 at 09:34:33AM -0700, Shuah Khan wrote:
On 1/5/21 9:21 AM, Petr Mladek wrote:
On Mon 2021-01-04 09:23:57, Shuah Khan wrote:
On 12/22/20 4:11 AM, Andy Shevchenko wrote:
On Mon, Dec 21, 2020 at 11:39:00PM -0800, David Gow wrote:
kunit_tool relies on the UML console outputting printk() output to the
tty in order to get results. Since the default console driver could
change, pass 'console=tty' to the kernel.

This is triggered by a change[1] to use ttynull as a fallback console
driver which -- by chance or by design -- seems to have changed the
default console output on UML, breaking kunit_tool. While this may be
fixed, we should be less fragile to such changes in the default.

[1]:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=757055ae8dedf5333af17b3b5b4b70ba9bc9da4e

Reported-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Tested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>


Thank you all. Now in linux-kselftest kunit-fixes branch.

Will send this up for rc3.

Sorry for the delay - have been away from the keyboard for a
bit.

JFYI, I am not sure that this is the right solution. I am
looking into it, see
https://lore.kernel.org/linux-kselftest/X%2FSRA1P8t+ONZFKb@alley/
for more details.


Thanks Petr. I will hold off on sending the patch up to Linus and
let you find a the right solution.

Please. leave it in Linux Next at least. Otherwise kunit will be broken for a
long time which is not good.



Yes. That is the plan. It will be in there until real fix comes in.

thanks,
-- Shuah