Re: BUG : PowerPC RCU: torture test failed with __stack_chk_fail

[Michael Ellerman]

Zhouyi Zhou <zhouzhouyi@xxxxxxxxx> writes:
> On Thu, Apr 27, 2023 at 11:09 AM Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote:
>>
>> Zhouyi Zhou <zhouzhouyi@xxxxxxxxx> writes:
>> > On Tue, Apr 25, 2023 at 2:01 PM Zhouyi Zhou <zhouzhouyi@xxxxxxxxx> wrote:
>> >> On Tue, Apr 25, 2023 at 6:07 AM Michael Ellerman <mpe@xxxxxxxxxxxxxx> 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/ppc64le/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