Re: [clear_page] 0ad07c8104 BUG: unable to handle kernel NULL pointer dereference at 0000000000000040

From: Fengguang Wu
Date: Sat Feb 18 2017 - 20:07:29 EST


On Sun, Feb 19, 2017 at 01:10:47AM +0100, Borislav Petkov wrote:
Hey Fengguang,

On Sun, Feb 19, 2017 at 07:29:50AM +0800, Fengguang Wu wrote:
Good point! I noticed it too while sending out the report. It'll be
showed as this in future:

https://github.com/0day-ci/linux/commits/Borislav-Petkov/x86-Optimize-clear_page/20170210-053052

How about pointing to the patch directly?

https://github.com/0day-ci/linux/commit/0ad07c8104eb5c12dfcb86581c1cc657183496cc

Yes if we add it as a line below the branch URL, it could be a time saver.

Sorry the 2nd report was send out manually and I only checked the
emails in my _current_ mbox. Since the previous report email has been
archived, it slipped through the duplication check.

No worries - this was all a prelude to me hinting at the email-based
talking to the bot :-)

CC Xiaolong. It's possible to automate the test-of-fixup-patches.
Firstly find out the original email report by the Message-ID being
replied to. Then fetch all the information required for deciding where
the patch should be applied to, parameters to auto-testing the patch.

Sounds like a plan.

It would probably even be easier for the bot if the reply-mail contained
specially-formatted hints like:

TEST-WITH-BELOW-PATCH: ...

or so.

Since it's hard to teach ALL people about the rule, it'd be best if we
can work w/o any rules -- unless you want to be accurate&helpful or to
customize test behaviors.

Since we already tested the original patch/commit (hence the report),
we should know where the fixup should be applied to. And it'd be
reasonably easy to tell whether the fix is incremental or a
replacement -- just try git-am onto the original commit first, if
failed, continue to try the parent commit. For old bugs the fix could
be against linus/master or linux-next/master, which could be tried too.

Btw, another nice aspect of this talking back to the bot is that before
I, as a recipient of the bug report, go and try to prepare a guest or
find a machine to reproduce properly, I can send a quick diff to the bot
in the meantime and say, "try this on the guest. I have a hunch it might
fix it."

Yes, that'd be most convenient. In general the email interface could
be something like this:

# "key: value" fields; if you Re: to an earlier bug report, they can be auto retrieved
compiler: gcc-6 # optional
base-commit: v4.10-rc8 # the robot knows kernel commits from hundreds of public git trees
---
the patch
---
attach kconfig files

Yeah we have a TODO to do email based on-demand service, which looks
close to your proposal.

Cool. Ping me if you need testers.

Thanks!

Thanks,
Fengguang