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Re: [PATCH][RFA] Fix -fstack-check with really big frames on aarch64
On 06/22/2017 12:23 PM, Florian Weimer wrote:
> * Mike Stump:
>> On Jun 22, 2017, at 8:32 AM, Jeff Law <firstname.lastname@example.org> wrote:
>>> Sure. I'll do something with 20031023-1.c to ensure it or an equivalent
>>> is compiled with -fstack-check. That isn't totally unexpected. I
>>> would have also been receptive to adding -fstack-check to the torture flags.
>> Ouch. Though stack checking might be important, the feature is very,
>> very narrow, and once tested, if unlike to ever break or interact
>> badly with other work. I'd rather people default it to on, run the
>> entire suite, fix all bugs (with test cases added for all the bugs),
>> then turn it back off.
> Are there many tests which give different results with and without
> stack checking?
It's not terrible. Some are simply dump scanning regexps that need
updating and some guality stuff -- at least on x86, ppc & aarch.
> I expect that eventually, there will be a configure flag which
> controls whether stack checking is enabled by default (similar to
> PIE-by-default), and we could thus rely on tester variance to cover
> the test suite with both flag states.
That'd be my expectation as well.
But I still think we're going to want to explicitly test the various
cases where we want to see probes vs when we do not. That kind of
testing won't be covered unless we explicitly do so and the least
painful way to cover may be via dump messages or the unit testing framework.