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Re: [PATCH] [BZ #21391] x86: Set dl_platform and dl_hwcap from CPU features
- From: "H.J. Lu" <hjl dot tools at gmail dot com>
- To: Florian Weimer <fweimer at redhat dot com>
- Cc: GNU C Library <libc-alpha at sourceware dot org>
- Date: Wed, 3 May 2017 07:36:42 -0700
- Subject: Re: [PATCH] [BZ #21391] x86: Set dl_platform and dl_hwcap from CPU features
- Authentication-results: sourceware.org; auth=none
- References: <20170419183532.GA18407@intel.com> <792761c6-5f72-cadf-eb94-9fa408d111b3@redhat.com> <CAMe9rOooS5tjBs4PkLvSoAqbfpRfMNBwoh6OCGxx-ERTSUPtZA@mail.gmail.com> <da98ac61-dde1-7c6d-8543-13f472f38f3e@redhat.com> <CAMe9rOqB5EMPx8foHSb67354JOuio38fk=YwV_R0yH9Nu1yusg@mail.gmail.com> <CAMe9rOq9RjbJScAzxV0GiBAmb=U8YiYiiYYr6yU1qjtBVHx-7g@mail.gmail.com> <0a8475bd-ca19-1ecf-588d-574578f82d0e@redhat.com> <CAMe9rOoLd-16Gqk9mBgMFwa-nxR-baFiH9FoBfa6PqGA7cZ1TQ@mail.gmail.com>
On Fri, Apr 28, 2017 at 8:51 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Fri, Apr 28, 2017 at 7:45 AM, Florian Weimer <fweimer@redhat.com> wrote:
>> On 04/28/2017 04:44 PM, H.J. Lu wrote:
>>>
>>> Any other comments?
>>
>>
>> I don't have any further comments.
>>
>> Except maybe this: Why isn't this is in the kernel, like for the other
>> architectures?
>>
>
> On x86, CPUID is available to both kernel and user space. Kernel
> sets AT_PLATFORM and AT_HWCAP from CPUID. But it isn't flexible
> for setting dynamic linker search path. There is no support for platform
> nor hardware capability in dynamic linker search path for x86-64.
> AT_HWCAP only provides a small subset of features from CPUID. My
> patch sets dynamic linker search path in user space from CPUID. It
> works for both i386 and x86-64.
>
I will check it today.
--
H.J.