From: Ren Qiaowei <qiaowei.ren@intel.com>
To: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/5] x86, mpx: hook #BR exception handler to allocate bound tables
Date: Mon, 13 Jan 2014 11:17:15 +0800 [thread overview]
Message-ID: <52D35ABB.8070904@intel.com> (raw)
In-Reply-To: <20140112092019.GA3664@pd.tnic>
On 01/12/2014 05:20 PM, Borislav Petkov wrote:
> On Sun, Jan 12, 2014 at 05:20:00PM +0800, Qiaowei Ren wrote:
>> +static bool allocate_bt(unsigned long bd_entry)
>> +{
>> + unsigned long bt_size = 1UL << (MPX_L2_BITS+MPX_L2_SHIFT);
>> + unsigned long bt_addr, old_val;
>> +
>> + bt_addr = sys_mmap_pgoff(0, bt_size, PROT_READ | PROT_WRITE,
>> + MAP_ANONYMOUS | MAP_PRIVATE | MAP_POPULATE, -1, 0);
>
> Are we sure about this? We can do a possible memory allocation in
> mmap_region() in this exception handler context. And yes, we do a
> conditional_sti(), which makes it all the more susceptible.
>
> Have you run this with lockdep enabled?
>
Yes, I run this with lockdep enabled.
Thanks,
Qiaowei
next prev parent reply other threads:[~2014-01-13 3:22 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-12 9:19 [PATCH 1/5] x86, mpx: add documentation on Intel MPX Qiaowei Ren
2014-01-12 9:20 ` [PATCH 2/5] x86, mpx: hook #BR exception handler to allocate bound tables Qiaowei Ren
2014-01-12 9:20 ` Borislav Petkov
2014-01-13 3:17 ` Ren Qiaowei [this message]
2014-01-13 10:38 ` Borislav Petkov
2014-01-17 14:47 ` Ren, Qiaowei
2014-01-17 16:47 ` Borislav Petkov
2014-01-17 16:51 ` H. Peter Anvin
2014-01-17 17:14 ` Steven Rostedt
2014-01-17 17:51 ` H. Peter Anvin
2014-01-19 12:50 ` Ren, Qiaowei
2014-01-17 17:10 ` Steven Rostedt
2014-01-17 16:31 ` H. Peter Anvin
2014-01-17 16:48 ` Borislav Petkov
2014-01-17 16:51 ` H. Peter Anvin
2014-01-17 16:56 ` Borislav Petkov
2014-01-17 16:58 ` H. Peter Anvin
2014-01-17 17:04 ` Borislav Petkov
2014-01-17 17:30 ` H. Peter Anvin
2014-01-17 18:23 ` Borislav Petkov
2014-01-17 18:25 ` H. Peter Anvin
2014-01-12 9:20 ` [PATCH 3/5] x86, mpx: add prctl commands PR_MPX_INIT, PR_MPX_RELEASE Qiaowei Ren
2014-01-12 9:20 ` [PATCH 4/5] x86, mpx: add MPX related opcodes to the x86 opcode map Qiaowei Ren
2014-01-17 19:04 ` H. Peter Anvin
2014-01-17 19:22 ` [tip:x86/mpx] x86, mpx: Add " tip-bot for Qiaowei Ren
2014-01-12 9:20 ` [PATCH 5/5] x86, mpx: extend siginfo structure to include bound violation information Qiaowei Ren
2014-01-12 9:30 ` Borislav Petkov
2014-01-12 16:49 ` H. Peter Anvin
2014-01-12 17:03 ` Borislav Petkov
2014-01-12 17:06 ` H. Peter Anvin
2014-01-13 3:09 ` Ren Qiaowei
2014-01-13 8:22 ` Ren Qiaowei
2014-01-13 10:43 ` Borislav Petkov
2014-01-17 14:55 ` Ren, Qiaowei
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