From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@kernel.org>, Ren Qiaowei <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: Re: [PATCH v3 3/4] x86, mpx: add prctl commands PR_MPX_INIT, PR_MPX_RELEASE
Date: Sun, 26 Jan 2014 17:50:30 -0800 [thread overview]
Message-ID: <52E5BB66.8060104@zytor.com> (raw)
In-Reply-To: <20140126083942.GB29339@gmail.com>
On 01/26/2014 12:39 AM, Ingo Molnar wrote:
>>
>> It will be only once per startup.
>
> In that case it would be more efficient to make this part of the
> binary execution environment so that exec() sets it up automatically,
> not a separate prctl() syscall.
>
This is not necessarily possible, and in particular it might need to be
deferred until the MPX runtime has initialized.
What isn't clear to me is if these syscalls are needed at all, or if it
would be better to just let the MPX runtile set BNDSTATUS and BNDCFGU
directly in userspace. The kernel cannot rely on them staying
consistent across userspace anyway.
Now, it might be beneficial for the kernel to have them anyway. It's a
bit of a tough call.
-hpa
next prev parent reply other threads:[~2014-01-27 1:50 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-26 9:08 [PATCH v3 0/4] Intel MPX support Qiaowei Ren
2014-01-26 8:19 ` Ingo Molnar
2014-01-26 8:20 ` Ren Qiaowei
2014-01-28 6:42 ` Ingo Molnar
2014-01-28 7:01 ` Ren Qiaowei
2014-01-28 18:26 ` H. Peter Anvin
2014-01-26 9:08 ` [PATCH v3 1/4] x86, mpx: add documentation on Intel MPX Qiaowei Ren
2014-01-26 3:06 ` Randy Dunlap
2014-01-26 3:15 ` Ren Qiaowei
2014-01-27 20:27 ` Andy Lutomirski
2014-01-28 3:40 ` Ren Qiaowei
2014-01-26 9:08 ` [PATCH v3 2/4] x86, mpx: hook #BR exception handler to allocate bound tables Qiaowei Ren
2014-01-27 20:36 ` Andy Lutomirski
2014-01-28 3:35 ` Ren Qiaowei
2014-01-28 5:21 ` Andy Lutomirski
2014-01-28 5:39 ` Ren Qiaowei
2014-01-28 6:42 ` Andy Lutomirski
2014-01-28 6:46 ` Ren Qiaowei
2014-01-26 9:08 ` [PATCH v3 3/4] x86, mpx: add prctl commands PR_MPX_INIT, PR_MPX_RELEASE Qiaowei Ren
2014-01-26 8:22 ` Ingo Molnar
2014-01-26 8:23 ` Ren Qiaowei
2014-01-26 8:39 ` Ingo Molnar
2014-01-26 11:37 ` Ren, Qiaowei
2014-01-27 1:50 ` H. Peter Anvin [this message]
2014-01-27 1:55 ` Ren Qiaowei
2014-01-27 2:10 ` H. Peter Anvin
2014-01-27 2:16 ` Ren Qiaowei
2014-01-27 21:54 ` Andy Lutomirski
2014-01-27 22:01 ` H. Peter Anvin
2014-01-26 9:08 ` Ingo Molnar
2014-01-26 12:49 ` Ren, Qiaowei
2014-01-26 15:14 ` Ingo Molnar
2014-01-27 2:01 ` Ren Qiaowei
2014-01-27 20:59 ` Andy Lutomirski
2014-01-26 9:08 ` [PATCH v3 4/4] x86, mpx: extend siginfo structure to include bound violation information Qiaowei Ren
2014-01-26 4:22 ` David Rientjes
2014-01-26 4:39 ` Ren Qiaowei
2014-01-26 21:38 ` David Rientjes
2014-01-27 1:34 ` Ren Qiaowei
2014-01-27 1:53 ` H. Peter Anvin
2014-01-27 1:56 ` Ren Qiaowei
2014-01-27 21:58 ` Andy Lutomirski
2014-01-28 2:43 ` Ren Qiaowei
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