From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: Florian Weimer <fweimer@redhat.com>,
Tulio Magno Quites Machado Filho via Libc-alpha
<libc-alpha@sourceware.org>
Subject: Re: [PATCH v2] powerpc64: Workaround sigtramp vdso return call
Date: Thu, 11 Feb 2021 23:14:00 -0300 [thread overview]
Message-ID: <d9fd15ac-7f01-d81d-373d-16485f2268c8@linaro.org> (raw)
In-Reply-To: <87lfbumfpx.fsf@oldenburg.str.redhat.com>
On 11/02/2021 18:55, Florian Weimer wrote:
> * Tulio Magno Quites Machado Filho via Libc-alpha:
>
>>> LGTM, it is ok for 2.33.
>>>
>>> Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
>>
>> Pushed as 5ee506ed35a2c9184bcb1fb5e79b6cceb9bb0dd1
>
> Why isn't this handled as a kernel regression?
I don't have a strong opinion about it, but this issue is presented on
at least two already released versions (5.9 and 5.10) and it falls on
the category where it might characterize as ABI abuse: backtrace is
relying on a specific semantic where kernel/vDSO does provide a working
solution that does not suffer from this inherent limitation (unwinder
information produced by CFI).
It see this similar to how some sanitizer code expects some invariant
glibc internals and need to handle with ad-hoc code (such as struct
pthread internal size). This issue for the sanitize case is slight
worse because there is proper solution.
That's why I suggested in the original thread to get rid of the powerpc
optimization and implement the backtrace as other architectures does
(through libgcc). I was hopping that IBM could work on this one.
next prev parent reply other threads:[~2021-02-12 2:14 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-27 19:23 Raoni Fassina Firmino
2021-01-27 19:33 ` Adhemerval Zanella
2021-01-28 16:59 ` Tulio Magno Quites Machado Filho
2021-02-11 21:55 ` Florian Weimer
2021-02-12 2:14 ` Adhemerval Zanella [this message]
2021-02-15 17:51 ` Raoni Fassina Firmino
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