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Re: valgrind support for glibc master
- From: Szabolcs Nagy <szabolcs dot nagy at arm dot com>
- To: Florian Weimer <fweimer at redhat dot com>, Siddhesh Poyarekar <siddhesh at gotplt dot org>, Mark Wielaard <mjw at fedoraproject dot org>
- Cc: nd at arm dot com, GNU C Library <libc-alpha at sourceware dot org>, The GNU C Library support for Fedora <glibc at lists dot fedoraproject dot org>
- Date: Fri, 23 Jun 2017 12:25:19 +0100
- Subject: Re: valgrind support for glibc master
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On 23/06/17 12:13, Florian Weimer wrote:
> On 06/23/2017 01:10 PM, Siddhesh Poyarekar wrote:
>> On Friday 23 June 2017 04:31 PM, Mark Wielaard wrote:
>>> For now the auxv HWCAP is masked off on arm64 in valgrind fedora.
>>> https://bugzilla.redhat.com/show_bug.cgi?id=1464211#c1
>>> So you can reenable the sanity check again on fedora rawhide.
>>>
>>> Upstream bug is https://bugs.kde.org/show_bug.cgi?id=381556
>>> arm64: Handle feature registers access on 4.11 Linux kernel or later
>>
>> A better workaround would be to mask out HWCAP_CPUID (0x800) from the HWCAP.
>
> valgrind needs to mask out all unknown/unimplemented flags. And I
> thought it was 1? LD_HWCAP_MASK=1 acts as a workaround, after all.
>
because LD_HWCAP_MASK is the 'important hwcap bits'
and now that is 0x800 by default on aarch64, if you
unset that flag then the cpuid check is disabled.