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From: Florian Weimer <fweimer@redhat.com>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>,
	 Andrew Morton <akpm@linux-foundation.org>,
	 linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	 linux-api@vger.kernel.org,  x86@kernel.org
Subject: Re: [PATCH v2] ELF: supply userspace with available page shifts (AT_PAGE_SHIFT_MASK)
Date: Thu, 07 Dec 2023 16:32:51 +0100	[thread overview]
Message-ID: <8734wehvto.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <4f5f29d4-9c50-453c-8ad3-03a92fed192e@p183> (Alexey Dobriyan's message of "Thu, 7 Dec 2023 17:57:05 +0300")

* Alexey Dobriyan:

> On Wed, Dec 06, 2023 at 12:47:27PM -0800, Kees Cook wrote:
>> On Tue, Dec 05, 2023 at 07:01:34PM +0300, Alexey Dobriyan wrote:
>> > Report available page shifts in arch independent manner, so that
>> > userspace developers won't have to parse /proc/cpuinfo hunting
>> > for arch specific strings:
>> > 
>> > Note!
>> > 
>> > This is strictly for userspace, if some page size is shutdown due
>> > to kernel command line option or CPU bug workaround, than is must not
>> > be reported in aux vector!
>> 
>> Given Florian in CC, I assume this is something glibc would like to be
>> using? Please mention this in the commit log.
>
> glibc can use it. Main user is libhugetlbfs, I guess:
>
> 	https://github.com/libhugetlbfs/libhugetlbfs/blob/master/hugeutils.c#L915
>
> Loop inside getauxval() can run faster than opendir().

Is libhugetlbfs still maintained?  Last commit was three years ago?

Thanks,
Florian


  reply	other threads:[~2023-12-07 15:32 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-12-04 17:18 [PATCH] ELF: supply userspace with available page shifts (AT_PAGE_SHIFT_LIST) Alexey Dobriyan
2023-12-05  9:51 ` Florian Weimer
2023-12-05 14:26   ` Alexey Dobriyan
2023-12-05 16:01   ` [PATCH v2] ELF: supply userspace with available page shifts (AT_PAGE_SHIFT_MASK) Alexey Dobriyan
2023-12-06 20:47     ` Kees Cook
2023-12-06 21:05       ` Florian Weimer
2023-12-06 21:09         ` Kees Cook
2023-12-07 15:04           ` Alexey Dobriyan
2023-12-07 14:57       ` Alexey Dobriyan
2023-12-07 15:32         ` Florian Weimer [this message]
2023-12-08 18:29         ` Kees Cook
2023-12-08 18:35           ` Florian Weimer
2023-12-08 18:38             ` Kees Cook
2023-12-09  9:44           ` Alexey Dobriyan
2023-12-07 18:44     ` [PATCH v3] ELF: AT_PAGE_SHIFT_MASK -- supply userspace with available page shifts Alexey Dobriyan
2023-12-12 21:09       ` Kees Cook

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