From: Dave Hansen <dave.hansen@intel.com>
To: "Ren, Qiaowei" <qiaowei.ren@intel.com>,
One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "x86@kernel.org" <x86@kernel.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v8 08/10] x86, mpx: add prctl commands PR_MPX_REGISTER, PR_MPX_UNREGISTER
Date: Mon, 15 Sep 2014 21:17:02 -0700 [thread overview]
Message-ID: <5417B9BE.1030209@intel.com> (raw)
In-Reply-To: <9E0BE1322F2F2246BD820DA9FC397ADE017AE183@shsmsx102.ccr.corp.intel.com>
On 09/15/2014 08:20 PM, Ren, Qiaowei wrote:
>> What are the semantics across execve() ?
>>
> This will not impact on the semantics of execve(). One runtime
> library
> for MPX will be provided (or merged into Glibc), and when the
> application starts, this runtime will be called to initialize MPX
> runtime environment, including calling prctl() to notify the kernel to
> start managing the bounds directories. You can see the discussion
> about exec(): https://lkml.org/lkml/2014/1/26/199
I think he's asking what happens to the kernel value at execve() time.
The short answer is that it is zero'd along with the rest of a new mm.
It probably _shouldn't_ be, though. It's actually valid to have a bound
directory at 0x0. We probably need to initialize it to -1 instead, and
that means initializing to -1 at execve() time.
next prev parent reply other threads:[~2014-09-16 4:17 UTC|newest]
Thread overview: 65+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-11 8:46 [PATCH v8 00/10] Intel MPX support Qiaowei Ren
2014-09-11 8:46 ` [PATCH v8 01/10] x86, mpx: introduce VM_MPX to indicate that a VMA is MPX specific Qiaowei Ren
2014-09-11 8:46 ` [PATCH v8 02/10] x86, mpx: add MPX specific mmap interface Qiaowei Ren
2014-09-11 8:46 ` [PATCH v8 03/10] x86, mpx: add macro cpu_has_mpx Qiaowei Ren
2014-09-11 8:46 ` [PATCH v8 04/10] x86, mpx: hook #BR exception handler to allocate bound tables Qiaowei Ren
2014-09-12 22:58 ` Dave Hansen
2014-09-13 7:24 ` Ren, Qiaowei
2014-09-24 14:40 ` Dave Hansen
2014-09-11 8:46 ` [PATCH v8 05/10] x86, mpx: extend siginfo structure to include bound violation information Qiaowei Ren
2014-09-11 8:46 ` [PATCH v8 06/10] mips: sync struct siginfo with general version Qiaowei Ren
2014-09-11 22:13 ` Thomas Gleixner
2014-09-12 2:54 ` Ren, Qiaowei
2014-09-12 8:17 ` Thomas Gleixner
2014-09-13 7:13 ` Ren, Qiaowei
2014-09-11 8:46 ` [PATCH v8 07/10] x86, mpx: decode MPX instruction to get bound violation information Qiaowei Ren
2014-09-11 22:18 ` Thomas Gleixner
2014-09-11 22:32 ` Dave Hansen
2014-09-11 22:35 ` H. Peter Anvin
2014-09-11 23:37 ` Thomas Gleixner
2014-09-12 4:44 ` H. Peter Anvin
2014-09-12 13:10 ` Thomas Gleixner
2014-09-12 13:39 ` H. Peter Anvin
2014-09-12 17:48 ` Thomas Gleixner
2014-09-12 17:52 ` Thomas Gleixner
2014-09-12 19:07 ` H. Peter Anvin
2014-09-11 8:46 ` [PATCH v8 08/10] x86, mpx: add prctl commands PR_MPX_REGISTER, PR_MPX_UNREGISTER Qiaowei Ren
2014-09-11 15:03 ` Dave Hansen
2014-09-12 3:10 ` Ren, Qiaowei
2014-09-11 23:28 ` Thomas Gleixner
2014-09-12 0:10 ` Dave Hansen
2014-09-12 8:11 ` Thomas Gleixner
2014-09-12 9:24 ` Thomas Gleixner
2014-09-12 14:36 ` Dave Hansen
2014-09-12 17:34 ` Thomas Gleixner
2014-09-12 18:42 ` Thomas Gleixner
2014-09-12 20:35 ` Dave Hansen
2014-09-12 20:18 ` Dave Hansen
2014-09-13 9:01 ` Thomas Gleixner
2014-09-12 15:22 ` Dave Hansen
2014-09-12 17:42 ` Thomas Gleixner
2014-09-12 20:33 ` Dave Hansen
2014-09-15 0:00 ` One Thousand Gnomes
2014-09-16 3:20 ` Ren, Qiaowei
2014-09-16 4:17 ` Dave Hansen [this message]
2014-09-16 7:50 ` Kevin Easton
2014-09-18 0:40 ` Ren, Qiaowei
2014-09-18 3:23 ` Kevin Easton
2014-09-18 2:37 ` Ren, Qiaowei
2014-09-18 4:43 ` Dave Hansen
2014-09-18 7:17 ` Kevin Easton
2014-09-18 6:20 ` Dave Hansen
2014-09-11 8:46 ` [PATCH v8 09/10] x86, mpx: cleanup unused bound tables Qiaowei Ren
2014-09-11 14:59 ` Dave Hansen
2014-09-12 3:02 ` Ren, Qiaowei
2014-09-12 4:59 ` Dave Hansen
2014-09-15 20:53 ` Dave Hansen
2014-09-16 8:06 ` Ren, Qiaowei
2014-09-11 8:46 ` [PATCH v8 10/10] x86, mpx: add documentation on Intel MPX Qiaowei Ren
2014-09-12 0:51 ` [PATCH v8 00/10] Intel MPX support Dave Hansen
2014-09-12 19:21 ` Thomas Gleixner
2014-09-12 21:23 ` Dave Hansen
2014-09-13 9:25 ` Thomas Gleixner
2014-09-12 21:31 ` Dave Hansen
2014-09-12 22:08 ` Dave Hansen
2014-09-13 9:39 ` Thomas Gleixner
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