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From:   Michael Ellerman <mpe@ellerman.id.au>
To:     Zhouyi Zhou <zhouzhouyi@gmail.com>
Cc:     linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
        rcu <rcu@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>, lance@osuosl.org,
        "Paul E. McKenney" <paulmck@kernel.org>
Subject: Re: BUG : PowerPC RCU: torture test failed with __stack_chk_fail
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Date:   Fri, 28 Apr 2023 00:13:11 +1000
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Zhouyi Zhou <zhouzhouyi@gmail.com> writes:
> On Thu, Apr 27, 2023 at 11:09=E2=80=AFAM Michael Ellerman <mpe@ellerman.i=
d.au> wrote:
>>
>> Zhouyi Zhou <zhouzhouyi@gmail.com> writes:
>> > On Tue, Apr 25, 2023 at 2:01=E2=80=AFPM Zhouyi Zhou <zhouzhouyi@gmail.=
com> wrote:
>> >> On Tue, Apr 25, 2023 at 6:07=E2=80=AFAM Michael Ellerman <mpe@ellerma=
n.id.au> wrote:
>> ...
>> >> >
>> >> > There's 12.2.0 here:
>> >> >   https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/x86=
_64/12.2.0/
>> >> >   https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/ppc=
64le/12.2.0/
>>
>> > powerpc64le-linux-gnu-gcc-12 cross compiler on my Ubuntu 22.04 does
>> > not seem to have that issue as gcc-10 does
>>
>> OK. So so far it's only that GCC 10 that shows the problem.
>>
>> If you have time, you could use some of the other versions to narrow
>> down which versions show the bug:
>>
>>   https://mirrors.edge.kernel.org/pub/tools/crosstool/files/bin/ppc64le/
>>
>> There's an 11.0, 11.1 and 11.3 there, as well as 9.5 and so on.
> GCC test results (Tested on PPC VM of Open Source Lab of Oregon State
> University)
> gcc 9.4 (ubuntu native):          positive, show bug
> gcc 9.5 (download form [1]):   positive, show bug
> gcc 10.1 (download from [1]): positive, show bug
> gcc 10.3 (download from [1]): positive, show bug
> gcc 10.4 (download from [1]): positive, show bug
>
> gcc 11.0 (download from [1]): negative, no bug
> gcc 11.1 (download from [1]): negative, no bug
> gcc 11.3 (download from [1]): negative, no bug
> gcc 12.1 (download from [1]): negative, no bug
> gcc 12.2 (download from [1]): negative, no bug

Awesome work.

How are you testing for presence/absence of the bug? By running your
test and seeing if it crashes, or by looking at the generated code?

cheers