On Sat, Dec 04, 2021 at 10:50:47AM +0100, Dmitry Vyukov wrote: > On Wed, 1 Dec 2021 at 22:09, Paul E. McKenney <paulmck@xxxxxxxxxx> wrote: > > > > On Wed, Dec 01, 2021 at 12:50:07PM -0800, syzbot wrote: > > > syzbot suspects this issue was fixed by commit: > > > > > > commit 96017bf9039763a2e02dcc6adaa18592cd73a39d > > > Author: Paul E. McKenney <paulmck@xxxxxxxxxx> > > > Date: Wed Jul 28 17:53:41 2021 +0000 > > > > > > rcu-tasks: Simplify trc_read_check_handler() atomic operations > > > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1281d89db00000 > > > start commit: 5319255b8df9 selftests/bpf: Skip verifier tests that fail .. > > > git tree: bpf-next > > > kernel config: https://syzkaller.appspot.com/x/.config?x=9290a409049988d4 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=fe9d8c955bd1d0f02dc1 > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14990477300000 > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=105ebd84b00000 > > > > > > If the result looks correct, please mark the issue as fixed by replying with: > > > > #syz fix: rcu-tasks: Simplify trc_read_check_handler() atomic operations > > > > > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > > > > Give or take. There were quite a few related bugs, so some or all of > > the following commits might also have helped: > > > > cbe0d8d91415c rcu-tasks: Wait for trc_read_check_handler() IPIs > > 18f08e758f34e rcu-tasks: Add trc_inspect_reader() checks for exiting critical section > > 46aa886c483f5 rcu-tasks: Fix IPI failure handling in trc_wait_for_one_reader > > Thanks for checking. If we don't have one exact fix, let's go with > what syzbot suggested. At this point it does not matter much since all > of them are in most trees I assume. We just need to close the bug with > something. > > #syz fix: rcu-tasks: Simplify trc_read_check_handler() atomic operations Fair enough! > > Quibbles aside, it is nice to get an automated email about having fixed > > a bug as opposed to having added one. ;-) > > Yes, but one is not possible without the other :-) But of course it is possible! For example, syzkaller might find a bug that was already fixed, and then before notifying me about the bug, you see the fix. For example, by failing to reproduce a mainline bug on -rcu. Not that I particularly want to be auto-spammed about bugs that I have already fixed, mind you! ;-) Thanx, Paul
