From: "H. Peter Anvin" <hpa@zytor.com>
To: Mike Waychison <mikew@google.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>,
Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] x86: Allow disabling of sys_iopl, sys_ioperm
Date: Thu, 14 Jul 2011 13:37:20 -0700 [thread overview]
Message-ID: <4E1F5380.9020709@zytor.com> (raw)
In-Reply-To: <1310675693-9204-2-git-send-email-mikew@google.com>
On 07/14/2011 01:34 PM, Mike Waychison wrote:
> In some build environments, it is useful to allow disabling of IO
> accesses to hardware, without having to rely on CAP_SYS_RAWIO (which is
> already overloaded to mean many other things). One way that userland
> has access to IO accesses is via the iopl(2) and ioperm(2) system calls.
>
> Allow disabling of these system calls from ever being available via a
> configuration option, X86_SYS_IOPL. This is implemented by simply
> stubbing out the system calls and having them return ENOSYS when their
> functionality is disabled.
>
> Note that we default this option to 'y', so that existing kernel configs
> will continue to support sys_iopl and sys_ioperm as before.
>
Wouldn't it be more useful for this to be a sysctl? In particular, like
many similar things it probably should be a lockable sysctl (three
states: enabled, disabled, and locked-disabled).
Making it a compile-time option I'm very skeptical to.
-hpa
next prev parent reply other threads:[~2011-07-14 20:37 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-14 20:34 [PATCH 1/2] Kconfig: Allow disabling of CONFIG_DEVPORT Mike Waychison
2011-07-14 20:34 ` [PATCH 2/2] x86: Allow disabling of sys_iopl, sys_ioperm Mike Waychison
2011-07-14 20:37 ` H. Peter Anvin [this message]
2011-07-14 20:38 ` Mike Waychison
2011-07-14 20:40 ` H. Peter Anvin
2011-07-18 14:35 ` Jiri Kosina
2011-07-14 22:31 ` Andrew Morton
2011-07-14 22:35 ` H. Peter Anvin
2011-07-14 22:40 ` Mike Waychison
2011-07-14 22:45 ` H. Peter Anvin
2011-07-14 23:03 ` Alan Cox
2011-07-14 23:04 ` Alan Cox
2011-07-20 19:42 ` Ingo Molnar
2011-07-14 22:42 ` Alan Cox
2011-07-14 22:48 ` Mike Waychison
2011-07-14 23:00 ` Alan Cox
2011-07-14 23:20 ` Mike Waychison
2011-07-14 23:39 ` Alan Cox
2011-07-15 0:48 ` Mike Waychison
2011-07-15 9:55 ` Alan Cox
2011-07-15 18:13 ` Mike Waychison
2011-07-15 18:14 ` H. Peter Anvin
2011-07-15 22:30 ` Andrew G. Morgan
2011-07-15 22:42 ` Mike Waychison
2011-07-17 23:19 ` Eric Paris
2011-07-18 0:04 ` H. Peter Anvin
2011-07-14 21:21 ` [PATCH 1/2] Kconfig: Allow disabling of CONFIG_DEVPORT Greg KH
2011-07-14 22:17 ` Mike Waychison
2011-07-15 6:41 ` Greg KH
2011-07-15 13:13 ` Theodore Tso
2011-07-15 14:51 ` Greg KH
2011-07-15 14:58 ` Alan Cox
2011-07-15 15:19 ` Greg KH
2011-07-15 16:45 ` Mike Waychison
2011-07-15 17:01 ` Greg KH
2011-07-15 17:51 ` Mike Waychison
2011-07-15 18:10 ` H. Peter Anvin
2011-07-15 18:50 ` Andrew Morton
2011-07-15 18:55 ` Ted Ts'o
2011-07-16 7:56 ` Greg KH
2011-07-16 13:05 ` Ted Ts'o
2011-07-16 16:38 ` Christoph Hellwig
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