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From: Austin S Hemmelgarn <ahferroin7@gmail.com>
To: Arjan van de Ven <arjanvandeven@gmail.com>,
	Ingo Molnar <mingo@kernel.org>
Cc: Alex Henrie <alexhenrie24@gmail.com>,
	One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>,
	Kees Cook <keescook@chromium.org>,
	"H . Peter Anvin" <hpa@zytor.com>,
	Doug Johnson <dougvj@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Tyler Hicks <tyhicks@canonical.com>,
	Al Viro <viro@zeniv.linux.org.uk>,
	LKML <linux-kernel@vger.kernel.org>,
	Andy Lutomirski <luto@kernel.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Borislav Petkov <bp@alien8.de>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Arjan van de Ven <arjan@infradead.org>,
	Denys Vlasenko <dvlasenk@redhat.com>,
	Brian Gerst <brgerst@gmail.com>
Subject: Re: [PATCH v2] x86: Preserve iopl on fork and execve
Date: Tue, 12 May 2015 11:47:40 -0400	[thread overview]
Message-ID: <5552209C.501@gmail.com> (raw)
In-Reply-To: <CADyApD2-J07zg7gfa+LrFbHB_p2gN5k2P+x7OTCW1_rybTkdQA@mail.gmail.com>

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On 2015-05-12 11:25, Arjan van de Ven wrote:
>>
>> also the interesting question is:
>> can a process give up these perms?
>> otherwise it becomes a "once given, never gotten rid of" hell hole.
>
> If you look at a modern linux distro, nothing should need/use iopl and
> co anymore, so maybe an interesting
> question is if we can stick these behind a CONFIG_ option (default on
> of course for compatibility)... just like
> some of the /dev/mem like things are now hidable for folks who know
> they don't need them.
Personally, I _really_ like this idea.  The only thing I know of on any 
modern distro that even considers using ioperm is hwclock, and it only 
does so if it can't access the RTC through other means (and if you have 
an RTC, you really should have the /dev interface enabled).



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  reply	other threads:[~2015-05-12 15:47 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-11 23:38 [PATCH v2] x86: Preserve iopl on fork and execve Alex Henrie
2015-05-12  6:40 ` Ingo Molnar
2015-05-12 15:13   ` Linus Torvalds
2015-05-12 18:24     ` H. Peter Anvin
2015-05-12 15:24   ` Arjan van de Ven
2015-05-12 15:25     ` Arjan van de Ven
2015-05-12 15:47       ` Austin S Hemmelgarn [this message]
2015-05-12 18:05         ` Alex Henrie
2015-05-12 18:12           ` Austin S Hemmelgarn
2015-05-14 10:41       ` Josh Triplett
2015-05-15  0:52         ` H. Peter Anvin

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