upstream build error (12)

upstream build error (12)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    e609571b Merge tag 'nfs-for-5.11-2' of git://git.linux-nfs..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15965a00d00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6157970d0a91b812
dashboard link: https://syzkaller.appspot.com/bug?extid=76880518931d755473cf
compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+76880518931d755473cf@syzkaller.appspotmail.com

clang-11: error: unable to execute command: Aborted (core dumped)
clang-11: error: clang frontend command failed due to signal (use -v to see invocation)

---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

Re: upstream build error (12)

[Nathan Chancellor]

On Tue, Jan 12, 2021 at 11:20:27AM -0800, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    e609571b Merge tag 'nfs-for-5.11-2' of git://git.linux-nfs..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=15965a00d00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=6157970d0a91b812
> dashboard link: https://syzkaller.appspot.com/bug?extid=76880518931d755473cf
> compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+76880518931d755473cf@syzkaller.appspotmail.com
> 
> clang-11: error: unable to execute command: Aborted (core dumped)
> clang-11: error: clang frontend command failed due to signal (use -v to see invocation)
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

Would it be possible for clang-built-linux@googlegroups.com to be CC'd
when there is a build error and the compiler is clang? Especially if
clang is hitting an assertion.

Cheers,
Nathan

Re: upstream build error (12)

[Nathan Chancellor]

On Tue, Jan 12, 2021 at 12:40:58PM -0700, Nathan Chancellor wrote:
> On Tue, Jan 12, 2021 at 11:20:27AM -0800, syzbot wrote:
> > Hello,
> > 
> > syzbot found the following issue on:
> > 
> > HEAD commit:    e609571b Merge tag 'nfs-for-5.11-2' of git://git.linux-nfs..
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=15965a00d00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=6157970d0a91b812
> > dashboard link: https://syzkaller.appspot.com/bug?extid=76880518931d755473cf
> > compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
> > 
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+76880518931d755473cf@syzkaller.appspotmail.com
> > 
> > clang-11: error: unable to execute command: Aborted (core dumped)
> > clang-11: error: clang frontend command failed due to signal (use -v to see invocation)
> > 
> > ---
> > This report is generated by a bot. It may contain errors.
> > See https://goo.gl/tpsmEJ for more information about syzbot.
> > syzbot engineers can be reached at syzkaller@googlegroups.com.
> > 
> > syzbot will keep track of this issue. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 
> Would it be possible for clang-built-linux@googlegroups.com to be CC'd
> when there is a build error and the compiler is clang? Especially if
> clang is hitting an assertion.

I cannot reproduce this with clang 11.0.1. I did a reverse bisect on
LLVM and found commit 4b0aa5724fea ("Change the INLINEASM_BR MachineInstr
to be a non-terminating instruction.") as the fix (which makes sense,
that commit has direct kernel implications). It is probably worth
upgrading syzkaller's clang to 11.0.1, where I have not seen any
assertions across all of the configurations that I test.

Ccing Dmitry and Marco directly.

Cheers,
Nathan

Re: upstream build error (12)

[Marco Elver]

On Tue, 12 Jan 2021 at 21:32, Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> On Tue, Jan 12, 2021 at 12:40:58PM -0700, Nathan Chancellor wrote:
> > On Tue, Jan 12, 2021 at 11:20:27AM -0800, syzbot wrote:
> > > Hello,
> > >
> > > syzbot found the following issue on:
> > >
> > > HEAD commit:    e609571b Merge tag 'nfs-for-5.11-2' of git://git.linux-nfs..
> > > git tree:       upstream
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=15965a00d00000
> > > kernel config:  https://syzkaller.appspot.com/x/.config?x=6157970d0a91b812
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=76880518931d755473cf
> > > compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
> > >
> > > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > Reported-by: syzbot+76880518931d755473cf@syzkaller.appspotmail.com
> > >
> > > clang-11: error: unable to execute command: Aborted (core dumped)
> > > clang-11: error: clang frontend command failed due to signal (use -v to see invocation)
> > >
> > > ---
> > > This report is generated by a bot. It may contain errors.
> > > See https://goo.gl/tpsmEJ for more information about syzbot.
> > > syzbot engineers can be reached at syzkaller@googlegroups.com.
> > >
> > > syzbot will keep track of this issue. See:
> > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >
> > Would it be possible for clang-built-linux@googlegroups.com to be CC'd
> > when there is a build error and the compiler is clang? Especially if
> > clang is hitting an assertion.
>
> I cannot reproduce this with clang 11.0.1. I did a reverse bisect on
> LLVM and found commit 4b0aa5724fea ("Change the INLINEASM_BR MachineInstr
> to be a non-terminating instruction.") as the fix (which makes sense,
> that commit has direct kernel implications). It is probably worth
> upgrading syzkaller's clang to 11.0.1, where I have not seen any
> assertions across all of the configurations that I test.
>
> Ccing Dmitry and Marco directly.

I'll upgrade syzbot's clang 11. I think the version we use right now
was still a pre-release.

Thanks,
-- Marco

Re: upstream build error (12)

[Dmitry Vyukov]

On Tue, Jan 12, 2021 at 8:41 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> On Tue, Jan 12, 2021 at 11:20:27AM -0800, syzbot wrote:
> > Hello,
> >
> > syzbot found the following issue on:
> >
> > HEAD commit:    e609571b Merge tag 'nfs-for-5.11-2' of git://git.linux-nfs..
> > git tree:       upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=15965a00d00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=6157970d0a91b812
> > dashboard link: https://syzkaller.appspot.com/bug?extid=76880518931d755473cf
> > compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
> >
> > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > Reported-by: syzbot+76880518931d755473cf@syzkaller.appspotmail.com
> >
> > clang-11: error: unable to execute command: Aborted (core dumped)
> > clang-11: error: clang frontend command failed due to signal (use -v to see invocation)
> >
> > ---
> > This report is generated by a bot. It may contain errors.
> > See https://goo.gl/tpsmEJ for more information about syzbot.
> > syzbot engineers can be reached at syzkaller@googlegroups.com.
> >
> > syzbot will keep track of this issue. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> Would it be possible for clang-built-linux@googlegroups.com to be CC'd
> when there is a build error and the compiler is clang? Especially if
> clang is hitting an assertion.

Hi Nathan,

I am adding functionality to CC specific emails on build errors on
specific instances:
https://github.com/google/syzkaller/pull/2388

Re: upstream build error (12)

[Dmitry Vyukov]

On Thu, Jan 14, 2021 at 12:32 PM Dmitry Vyukov <dvyukov@google.com> wrote:
>
> On Tue, Jan 12, 2021 at 8:41 PM Nathan Chancellor
> <natechancellor@gmail.com> wrote:
> >
> > On Tue, Jan 12, 2021 at 11:20:27AM -0800, syzbot wrote:
> > > Hello,
> > >
> > > syzbot found the following issue on:
> > >
> > > HEAD commit:    e609571b Merge tag 'nfs-for-5.11-2' of git://git.linux-nfs..
> > > git tree:       upstream
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=15965a00d00000
> > > kernel config:  https://syzkaller.appspot.com/x/.config?x=6157970d0a91b812
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=76880518931d755473cf
> > > compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
> > >
> > > IMPORTANT: if you fix the issue, please add the following tag to the commit:
> > > Reported-by: syzbot+76880518931d755473cf@syzkaller.appspotmail.com
> > >
> > > clang-11: error: unable to execute command: Aborted (core dumped)
> > > clang-11: error: clang frontend command failed due to signal (use -v to see invocation)
> > >
> > > ---
> > > This report is generated by a bot. It may contain errors.
> > > See https://goo.gl/tpsmEJ for more information about syzbot.
> > > syzbot engineers can be reached at syzkaller@googlegroups.com.
> > >
> > > syzbot will keep track of this issue. See:
> > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >
> > Would it be possible for clang-built-linux@googlegroups.com to be CC'd
> > when there is a build error and the compiler is clang? Especially if
> > clang is hitting an assertion.
>
> Hi Nathan,
>
> I am adding functionality to CC specific emails on build errors on
> specific instances:
> https://github.com/google/syzkaller/pull/2388

I've updated configs to CC clang-built-linux@googlegroups.com. This
should take effect on the next build failure (hopefully).

Re: upstream build error (12)

[Nick Desaulniers]

On Thu, Jan 14, 2021 at 4:38 AM 'Dmitry Vyukov' via Clang Built Linux
<clang-built-linux@googlegroups.com> wrote:
>
> On Thu, Jan 14, 2021 at 12:32 PM Dmitry Vyukov <dvyukov@google.com> wrote:
> >
> > On Tue, Jan 12, 2021 at 8:41 PM Nathan Chancellor
> > <natechancellor@gmail.com> wrote:
> > >
> > > Would it be possible for clang-built-linux@googlegroups.com to be CC'd
> > > when there is a build error and the compiler is clang? Especially if
> > > clang is hitting an assertion.
> >
> > Hi Nathan,
> >
> > I am adding functionality to CC specific emails on build errors on
> > specific instances:
> > https://github.com/google/syzkaller/pull/2388
>
> I've updated configs to CC clang-built-linux@googlegroups.com. This
> should take effect on the next build failure (hopefully).

Thanks Dmitry, (and thanks Marco for updating syzbot's clang).

Marco, can you update:
https://github.com/google/syzkaller/blob/master/docs/syzbot.md#crash-does-not-reproduce

I wasn't able to reproduce the reported compiler crash with ToT llvm
and the reported config, so I assume it was a mid-release of llvm-11
bug that has since been fixed.  Do we need to report to syzbot to
close the issue? I did a quick skim of
https://github.com/google/syzkaller/blob/master/docs/syzbot.md, but it
looks like communication with syzbot is based on commit messages?
--
Thanks,
~Nick Desaulniers

Re: upstream build error (12)

[Marco Elver]

On Thu, 14 Jan 2021 at 19:07, Nick Desaulniers <ndesaulniers@google.com> wrote:
> On Thu, Jan 14, 2021 at 4:38 AM 'Dmitry Vyukov' via Clang Built Linux
> <clang-built-linux@googlegroups.com> wrote:
> >
> > On Thu, Jan 14, 2021 at 12:32 PM Dmitry Vyukov <dvyukov@google.com> wrote:
> > >
> > > On Tue, Jan 12, 2021 at 8:41 PM Nathan Chancellor
> > > <natechancellor@gmail.com> wrote:
> > > >
> > > > Would it be possible for clang-built-linux@googlegroups.com to be CC'd
> > > > when there is a build error and the compiler is clang? Especially if
> > > > clang is hitting an assertion.
> > >
> > > Hi Nathan,
> > >
> > > I am adding functionality to CC specific emails on build errors on
> > > specific instances:
> > > https://github.com/google/syzkaller/pull/2388
> >
> > I've updated configs to CC clang-built-linux@googlegroups.com. This
> > should take effect on the next build failure (hopefully).
>
> Thanks Dmitry, (and thanks Marco for updating syzbot's clang).
>
> Marco, can you update:
> https://github.com/google/syzkaller/blob/master/docs/syzbot.md#crash-does-not-reproduce

We have:

> compiler:       clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)

Which is in the list of compilers:
https://storage.googleapis.com/syzkaller/clang-11-prerelease-ca2dcbd030e.tar.xz

> I wasn't able to reproduce the reported compiler crash with ToT llvm
> and the reported config, so I assume it was a mid-release of llvm-11
> bug that has since been fixed.  Do we need to report to syzbot to
> close the issue? I did a quick skim of
> https://github.com/google/syzkaller/blob/master/docs/syzbot.md, but it
> looks like communication with syzbot is based on commit messages?

Given we this is likely due to a prerelease compiler, we can just use:

#syz invalid

^^ it should pick this up.

Thanks,
-- Marco