From: Florian Weimer <fweimer@redhat.com>
To: Mark Wielaard <mark@klomp.org>
Cc: libc-alpha@sourceware.org, gcc@gcc.gnu.org,
llvm-dev@lists.llvm.org, x86-64-abi@googlegroups.com, "Mallappa\,
Premachandra" <Premachandra.Mallappa@amd.com>,
"H.J. Lu" <hjl.tools@gmail.com>, Michael Matz <matz@suse.de>,
Tom Stellard <tstellar@redhat.com>, Jeff Law <law@redhat.com>
Subject: Re: New x86-64 micro-architecture levels
Date: Wed, 15 Jul 2020 16:56:00 +0200 [thread overview]
Message-ID: <87o8ogzv27.fsf@oldenburg2.str.redhat.com> (raw)
In-Reply-To: <ae608575d0b2d70dc8b6c06d49efe94edd4c7350.camel@klomp.org> (Mark Wielaard's message of "Wed, 15 Jul 2020 16:38:52 +0200")
* Mark Wielaard:
> One thing that wasn't clear to me from this proposal is how the glibc
> dynamic loader checks for the CPU feature flags. This is important for
> valgrind since it can communicate those through different means. cpuid
> interception, auxv AT_HWCAP/AT_HWCAP2 interception (but not AT_PLATFORM
> at the moment) and of course we can generate SIGILL for unsupported
> instructions. We currently don't intercept /proc/cpuinfo (but could).
glibc uses CPUID in combination with XGETBV. There is also a masking
feature which I have not reviewed, but given that it only takes features
away, I don't think it matters to valgrind.
Thanks,
Florian
next prev parent reply other threads:[~2020-07-15 14:56 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-10 17:30 Florian Weimer
2020-07-10 19:14 ` Joseph Myers
2020-07-13 7:55 ` Florian Weimer
2020-07-10 21:42 ` H.J. Lu
2020-07-13 6:23 ` Richard Biener
2020-07-13 7:40 ` Florian Weimer
2020-07-13 7:47 ` Jan Beulich
2020-07-13 13:31 ` H.J. Lu
2020-07-13 13:53 ` Jakub Jelinek
2020-07-13 8:57 ` Richard Biener
2020-07-13 6:49 ` Florian Weimer
2020-07-13 13:30 ` H.J. Lu
2020-07-11 7:40 ` Allan Sandfeld Jensen
2020-07-13 6:58 ` Florian Weimer
2020-07-15 14:38 ` Mark Wielaard
2020-07-15 14:45 ` H.J. Lu
2020-07-15 14:56 ` Florian Weimer [this message]
2020-07-21 16:05 ` Mallappa, Premachandra
2020-07-21 18:04 ` Florian Weimer
2020-07-22 1:31 ` Dongsheng Song
2020-07-22 8:44 ` Florian Weimer
2020-07-22 9:26 ` Richard Biener
2020-07-22 10:16 ` Florian Weimer
2020-07-22 13:50 ` Richard Biener
2020-07-22 14:21 ` H.J. Lu
2020-07-31 13:06 ` Carlos O'Donell
2020-07-22 7:48 ` Jan Beulich
2020-07-22 10:34 ` Florian Weimer
2020-07-22 11:41 ` Jan Beulich
2020-07-31 13:20 ` Carlos O'Donell
2020-07-22 16:45 ` Mallappa, Premachandra
2020-07-23 12:44 ` Michael Matz
2020-07-23 13:21 ` H.J. Lu
2020-07-28 15:54 ` Florian Weimer
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