linux-kernel - Re: [GIT pull] timers/core for v6.13-rc1

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20241120-kurort-belehren-9f5212e1dc18@brauner>
Date: Wed, 20 Nov 2024 20:44:33 +0100
From: Christian Brauner <brauner@...nel.org>
To: Ingo Molnar <mingo@...nel.org>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>, 
	Thomas Gleixner <tglx@...utronix.de>, linux-kernel@...r.kernel.org, x86@...nel.org
Subject: Re: [GIT pull] timers/core for v6.13-rc1

On Wed, Nov 20, 2024 at 05:10:37PM +0100, Ingo Molnar wrote:
> 
> * Christian Brauner <brauner@...nel.org> wrote:
> 
> > On Wed, Nov 20, 2024 at 01:12:28PM +0100, Ingo Molnar wrote:
> > > 
> > > * Christian Brauner <brauner@...nel.org> wrote:
> > > 
> > > > On Tue, Nov 19, 2024 at 04:33:45PM -0800, Linus Torvalds wrote:
> > > > > On Mon, 18 Nov 2024 at 11:22, Thomas Gleixner <tglx@...utronix.de> wrote:
> > > > > >
> > > > > 
> > > > > >   - Core infrastructure for VFS multigrain timestamping
> > > > > >
> > > > > >     This is required to allow the kernel to use coarse grained time stamps
> > > > > >     by default and switch to fine grained time stamps when inode attributes
> > > > > >     are actively observed via getattr().
> > > > > >
> > > > > >     These changes have been provided to the VFS tree as well, so that the
> > > > > >     VFS specific infrastructure could be built on top.
> > > > > 
> > > > > Bah. Except the vfs tree didn't take it as a shared branch, but
> > > > > instead cherry-picked the commits and as a result they are duplicate
> > > > > and caused a (trivial) merge conflict.
> > > > 
> > > > Wait, I'm confused. I definitely pulled that branch the day after Thomas
> > > > gave it to me and in my vfs.mgtime branch I clearly see:
> > > > 
> > > > commit d7c898a73f875bd205df53074c1d542766171da1
> > > > Merge: 8cf0b93919e1 2a15385742c6
> > > > Author:     Christian Brauner <brauner@...nel.org>
> > > > AuthorDate: Mon Oct 7 12:47:19 2024 +0200
> > > > Commit:     Christian Brauner <brauner@...nel.org>
> > > > CommitDate: Thu Oct 10 10:20:57 2024 +0200
> > > > 
> > > >     Merge tag 'timers-core-for-vfs' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tip/tip into vfs.mgtime
> > > > 
> > > >     Timekeeping interfaces for consumption by the VFS tree.
> > > > 
> > > >     Signed-off-by: Christian Brauner <brauner@...nel.org>
> > > > 
> > > > Unless I did something odd during the pull?
> > > 
> > > The problem was caused by two commits which got rebased in the VFS 
> > > tree:
> > > 
> > > Commit 1:
> > > 
> > >   ee3283c608df ("timekeeping: Add interfaces for handling timestamps with a floor value")
> > > 
> > >   commit ee3283c608dfa21251b0821d7bb198c7ae3189f6
> > >   Author:     Jeff Layton <jlayton@...nel.org>
> > >   AuthorDate: Wed Oct 2 17:27:16 2024 -0400
> > >   Commit:     Christian Brauner <brauner@...nel.org>
> > >   CommitDate: Thu Oct 10 10:20:46 2024 +0200
> > >               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > 
> > > Which is a rebase of Thomas's original commit:
> > > 
> > >   70c8fd00a9bd ("timekeeping: Add interfaces for handling timestamps with a floor value")
> > > 
> > >   commit 70c8fd00a9bd0509bbf7bccd9baea8bbd5ddc756
> > >   Author:     Jeff Layton <jlayton@...nel.org>
> > >   AuthorDate: Wed Oct 2 17:27:16 2024 -0400
> > >   Commit:     Thomas Gleixner <tglx@...utronix.de>
> > >   CommitDate: Sun Oct 6 20:56:07 2024 +0200
> > > 
> > > And commit 2:
> > > 
> > >   2a15385742c6 ("timekeeping: Add percpu counter for tracking floor swap events")
> > > 
> > >   commit 2a15385742c689a271345dcbb4c28b9c568bc7ce
> > >   Author:     Jeff Layton <jlayton@...nel.org>
> > >   AuthorDate: Wed Oct 2 17:27:17 2024 -0400
> > >   Commit:     Christian Brauner <brauner@...nel.org>
> > >   CommitDate: Thu Oct 10 10:20:46 2024 +0200
> > >               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > > 
> > > Which is a rebase of Thomas's original commit:
> > > 
> > >   96f9a366ec8a timekeeping: Add percpu counter for tracking floor swap events
> > > 
> > >   commit 96f9a366ec8abe027326d7aab84d64370019f0f1 (tag: timers-core-for-vfs)
> > >   Author:     Jeff Layton <jlayton@...nel.org>
> > >   AuthorDate: Wed Oct 2 17:27:17 2024 -0400
> > >   Commit:     Thomas Gleixner <tglx@...utronix.de>
> > >   CommitDate: Sun Oct 6 20:56:07 2024 +0200
> > 
> > I was just looking through my reflog and I realised that I did a rebase
> > onto v6.12-rc2 (v6.12-rc1 had a horribly virtqueue bug that made testing
> > in a vm a giant pain). Sorry about that I should've noticed that
> > earlier.
> 
> So, so sh1t happens, but I think there could also be a workflow bug 
> here: somehow your tooling added your Signed-off-by during the rebase, 
> to a commit not committed by you originally.

I see. I assume that happens because I have an ancient
.git/hooks/prepare-commit-msg which contains:

COMMIT_MSG_FILE=$1
COMMIT_SOURCE=$2

SOB=$(git var GIT_COMMITTER_IDENT | sed -n 's/^\(.*>\).*$/Signed-off-by: \1/p')
git interpret-trailers --in-place --trailer "$SOB" "$COMMIT_MSG_FILE"

I honestly have no idea anymore why I added that hook originally...

> 
> > Though I'm confused why -next didn't catch this. When that happens -next
> > usually reports duplicate commits. Hm... Did I miss the report?
> 
> I haven't seen duplicate commit warnings from -next for some time - but 
> it can detect accidental rebases, because without your SOB added -next 
> would have detected the incorrect SOB chain I believe. So I'd 
> investigate how your SOB got there. I don't think vanilla rebase is 
> adding it automatically?

Yes, vanilla rebase doesn't do this.