Question about pkg/vc/git.go:GetCommitsByTitles()

[Alexander Egorenkov]

Hi all,

i have a question about the function which finds fix commits.
At the moment syzkaller looks back a fixed period of time back in git
history to find a fix commit by title provided with "#syz fix". The fixed
value is 2 years, see pkg/vc/git.go:GetCommitsByTitles().

I found out that this is sometimes too short to find a fix commit for
our s390 syzbot :(

Do you see a problem increasing it to e.g. 5 years or longer ?
Or maybe introduce a syz-ci config for this to make it flexible ?

Thanks
Regards
Alex

[Dmitry Vyukov]

I guess we could increase it to 5 year. It seems to be called once per
repo/per poll. On syzbot we have 20 repos and poll every hour. So
should be fine.

Wonder how it happens that you have so old fix commits.
Is it because these old commits are backported to the tested tree? And
git log --since uses author date, while we would need commit date?
I don't see anything in 'man git log' that allows to use commit date
unfortunately.

[Alexander Egorenkov]

The problem is on our side :/

When i first set up our syzbot for s390 back in 2020, it found some
issues which your syzbot found as well, in the mean time they were fixed
and closed but not on our side, of course. Then i wrote a couple of
tools to compare s390 bug reports with the official ones in order to
identify already closed bug reports, that way i could close our bug
reports which are already fixed upstream. And now i'm trying to close
some old bug reports from 2020 and s390 syzbot cannot find the corresponding
fix commit because it looks only 2 years back in the git history.

The problem is i have to keep up with the bug reports found and fixed by
the official syzbot. And if i wait too long with that, then this
situation happens.

Regards
Alex

[Dmitry Vyukov]

I don't mind extending it to 5 years.
A slightly more elaborate solution would be to do a 5y poll first time
and do subsequent ones for 1y.