llvm dev - Feb 2019 - [cfe-dev] [8.0.0 Release] Need help with PR40761: Sanitizers broken on FreeBSD

That's excellent!

I think the check-sanitizer target should cover it.

Thanks,
Hans

On Fri, Feb 22, 2019 at 1:34 PM Kim Gräsman <kim.grasman at gmail.com>
wrote:
>
> Hi Hans,
>
> I have a freebsd machine and some time to spare this weekend.
>
> Could you offer the minimal git bisect command to repro? I'm hoping not
to have to run the full check-clang test suite if there's a smaller subset
of tests for ASAN.
>
> Thanks,
> - Kim
>
> On Thu, Feb 21, 2019, 11:27 Hans Wennborg via cfe-dev <cfe-dev at
lists.llvm.org> wrote:
>>
>> I think the release is looking pretty good, but there is one blocker
>> that's worrying me: https://llvm.org/PR40761
>>
>> From what I understand, ASan et al. used to work on FreeBSD but
don't
>> anymore, and there's nobody working on it.
>>
>> Is there someone who has access to a FreeBSD machine that could help
>> investigate this? Just getting it bisected would be super helpful.
>>
>> Thanks,
>> Hans
>> _______________________________________________
>> cfe-dev mailing list
>> cfe-dev at lists.llvm.org
>> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev

Hi again,

It took me a while to get the environment up and running. Turns out
the sanitizer test suite is in pretty bad shape overall on FreeBSD.

The target reproducing the DEADLYSIGNAL loop is check-asan-dynamic.

I ran the bisect all the way from release/7.x to release/8.x --

* release/7.x - normal test run
* $somewhere - another hang bug where the lit invocation stops dead
immediately after warning about %shared_libasan:

    llvm-lit: /home/kimgr/code/llvm-project/compiler-rt/test/asan/lit.cfg:110:
warning: %shared_libasan substitution not set but dynamic ASan is
available.

* 342d03e71fbc302cf5a1683dcd03c366bf96d4bb (Reimplement Thread Static
Data ASan routines with TLS) - AddressSanitizer:DEADLYSIGNAL

The DEADLYSIGNAL behavior is in fact introduced by
https://reviews.llvm.org/D55596. But it looks like FreeBSD was broken
even before this. I'll see if I can bisect where $somewhere is.

- Kim

On Fri, Feb 22, 2019 at 1:39 PM Hans Wennborg <hans at chromium.org>
wrote:
>
> That's excellent!
>
> I think the check-sanitizer target should cover it.
>
> Thanks,
> Hans
>
> On Fri, Feb 22, 2019 at 1:34 PM Kim Gräsman <kim.grasman at
gmail.com> wrote:
> >
> > Hi Hans,
> >
> > I have a freebsd machine and some time to spare this weekend.
> >
> > Could you offer the minimal git bisect command to repro? I'm
hoping not to have to run the full check-clang test suite if there's a
smaller subset of tests for ASAN.
> >
> > Thanks,
> > - Kim
> >
> > On Thu, Feb 21, 2019, 11:27 Hans Wennborg via cfe-dev <cfe-dev at
lists.llvm.org> wrote:
> >>
> >> I think the release is looking pretty good, but there is one
blocker
> >> that's worrying me: https://llvm.org/PR40761
> >>
> >> From what I understand, ASan et al. used to work on FreeBSD but
don't
> >> anymore, and there's nobody working on it.
> >>
> >> Is there someone who has access to a FreeBSD machine that could
help
> >> investigate this? Just getting it bisected would be super helpful.
> >>
> >> Thanks,
> >> Hans
> >> _______________________________________________
> >> cfe-dev mailing list
> >> cfe-dev at lists.llvm.org
> >> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev

Many thanks for digging into this, and sorry for my slow reply.

Kamil: it sounds like your commit is involved here. Any idea what's
happening?

Dimitry: If we don't find anyone to debug and fix this before the
release, how bad is it for FreeBSD? Can it be worked around downstream
if 8.0.0 ships without a fix? Since I'm not entirely sure how
supported this functionality is on FreeBSD, I'm not sure how much we
should block the release on it.

Kim: If you can bisect to find that $somewhere revision, that would be
very helpful.

Thanks,
Hans

On Sun, Feb 24, 2019 at 11:36 AM Kim Gräsman <kim.grasman at gmail.com>
wrote:
>
> Hi again,
>
> It took me a while to get the environment up and running. Turns out
> the sanitizer test suite is in pretty bad shape overall on FreeBSD.
>
> The target reproducing the DEADLYSIGNAL loop is check-asan-dynamic.
>
> I ran the bisect all the way from release/7.x to release/8.x --
>
> * release/7.x - normal test run
> * $somewhere - another hang bug where the lit invocation stops dead
> immediately after warning about %shared_libasan:
>
>     llvm-lit:
/home/kimgr/code/llvm-project/compiler-rt/test/asan/lit.cfg:110:
> warning: %shared_libasan substitution not set but dynamic ASan is
> available.
>
> * 342d03e71fbc302cf5a1683dcd03c366bf96d4bb (Reimplement Thread Static
> Data ASan routines with TLS) - AddressSanitizer:DEADLYSIGNAL
>
> The DEADLYSIGNAL behavior is in fact introduced by
> https://reviews.llvm.org/D55596. But it looks like FreeBSD was broken
> even before this. I'll see if I can bisect where $somewhere is.
>
> - Kim
>
> On Fri, Feb 22, 2019 at 1:39 PM Hans Wennborg <hans at chromium.org>
wrote:
> >
> > That's excellent!
> >
> > I think the check-sanitizer target should cover it.
> >
> > Thanks,
> > Hans
> >
> > On Fri, Feb 22, 2019 at 1:34 PM Kim Gräsman <kim.grasman at
gmail.com> wrote:
> > >
> > > Hi Hans,
> > >
> > > I have a freebsd machine and some time to spare this weekend.
> > >
> > > Could you offer the minimal git bisect command to repro? I'm
hoping not to have to run the full check-clang test suite if there's a
smaller subset of tests for ASAN.
> > >
> > > Thanks,
> > > - Kim
> > >
> > > On Thu, Feb 21, 2019, 11:27 Hans Wennborg via cfe-dev <cfe-dev
at lists.llvm.org> wrote:
> > >>
> > >> I think the release is looking pretty good, but there is one
blocker
> > >> that's worrying me: https://llvm.org/PR40761
> > >>
> > >> From what I understand, ASan et al. used to work on FreeBSD
but don't
> > >> anymore, and there's nobody working on it.
> > >>
> > >> Is there someone who has access to a FreeBSD machine that
could help
> > >> investigate this? Just getting it bisected would be super
helpful.
> > >>
> > >> Thanks,
> > >> Hans
> > >> _______________________________________________
> > >> cfe-dev mailing list
> > >> cfe-dev at lists.llvm.org
> > >> https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-dev