From mboxrd@z Thu Jan 1 00:00:00 1970
Return-Path: <thomas@monjalon.net>
Received: from out3-smtp.messagingengine.com (out3-smtp.messagingengine.com
[66.111.4.27]) by dpdk.org (Postfix) with ESMTP id F03C9A84C;
Fri, 12 Jan 2018 15:55:03 +0100 (CET)
Received: from compute1.internal (compute1.nyi.internal [10.202.2.41])
by mailout.nyi.internal (Postfix) with ESMTP id 681CE20F3B;
Fri, 12 Jan 2018 09:55:03 -0500 (EST)
Received: from frontend1 ([10.202.2.160])
by compute1.internal (MEProxy); Fri, 12 Jan 2018 09:55:03 -0500
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h=
cc:content-transfer-encoding:content-type:date:from:in-reply-to
:message-id:mime-version:references:subject:to:x-me-sender
:x-me-sender:x-sasl-enc; s=mesmtp; bh=O3mwQxvEhCi+DoIOP44sYnf+OO
Pn8y3d/gLgTVvGgKc=; b=I9I8s5yJhvDI30gi16hI0hIFne2ZdiaHilR1jDgJzI
qSLshMUE8Qjve7ulWBtVSQpRH3eSP9yU+3hNkGpAUqbLiaePFgb5PHZn2sldNezz
drUMATfquACk4io72b76ZBZyX27EpGyJVJkmaUHmR7epWnADyy6ZXtTssQVKjX9C
M=
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=
messagingengine.com; h=cc:content-transfer-encoding:content-type
:date:from:in-reply-to:message-id:mime-version:references
:subject:to:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=O3mwQx
vEhCi+DoIOP44sYnf+OOPn8y3d/gLgTVvGgKc=; b=EZxoxkXGjF+SZkaRJBeTIi
XfAdm9PQk0xl9AIgIkr0MJHfVawNDt0P9r9pGf4SDty9PNnTBS96WLw26hOBUPoW
dgBlBAy8Swmzzo8oliOAkVBMzPlTZ/U8AS7aeReDeK+3HUbzT/Hx8vijWCz4eAvF
5dJAH8rXiJQuPyaBDvNWNQiH6Jkw453xwzl+Eq/g8QQU3Q4KEfqC5Ql4bEoO8iF7
A/Rbf/yEBlI9Bn0ThrZjxiE4Sp47EsfsfQZy673V+5cBDzv2V+rJzXjz0fq2gIxD
ztm4R83drpJ6C5uPsrGbDAIFXXF4m6GzsAc0jywKu95yblX6pUFiTki/47MBqtrQ
==
X-ME-Sender: <xms:R8xYWmKMnTs3DBumak-0H7wmsDdRght8-4nBU3-vCaMXU7KEbHIp8g>
Received: from xps.localnet (184.203.134.77.rev.sfr.net [77.134.203.184])
by mail.messagingengine.com (Postfix) with ESMTPA id 1775D7E4C4;
Fri, 12 Jan 2018 09:55:03 -0500 (EST)
From: Thomas Monjalon <thomas@monjalon.net>
To: Anatoly Burakov <anatoly.burakov@intel.com>
Cc: dev@dpdk.org, stable@dpdk.org
Date: Fri, 12 Jan 2018 15:54:33 +0100
Message-ID: <17429603.yn0ZjX41h2@xps>
In-Reply-To: <be459294da93f5013e8a7be203a0253787224b2d.1513865614.git.anatoly.burakov@intel.com>
References: <be459294da93f5013e8a7be203a0253787224b2d.1513865614.git.anatoly.burakov@intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 7Bit
Content-Type: text/plain; charset="us-ascii"
Subject: Re: [dpdk-dev] [PATCH] eal: fix end for bounded malloc elements
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://dpdk.org/ml/options/dev>,
<mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://dpdk.org/ml/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://dpdk.org/ml/listinfo/dev>,
<mailto:dev-request@dpdk.org?subject=subscribe>
X-List-Received-Date: Fri, 12 Jan 2018 14:55:04 -0000
21/12/2017 17:54, Anatoly Burakov:
> In cases when alignment is bigger than boundary, we may incorrectly
> calculate end of a bounded malloc element.
>
> Consider this: suppose we are allocating a bounded malloc element
> that should be of 128 bytes in size, bounded to 128 bytes and
> aligned on a 256-byte boundary. Suppose our malloc element ends
> at 0x140 - that is, 256 plus one cacheline.
>
> So, right at the start, we are aligning our new_data_start to
> include the required element size, and to be aligned on a specified
> boundary - so new_data_start becomes 0. This fails the following
> bounds check, because our element cannot go above 128 bytes from
> the start, and we are at 320. So, we enter the bounds handling
> branch.
>
> While we're in there, we are aligning end_pt to our boundedness
> requirement of 128 byte, and end up with 0x100 (since 256 is
> 128-byte aligned). We recalculate new_data_size and it stays at
> 0, however our end is at 0x100, which is beyond the 128 byte
> boundary, and we report inability to reserve a bounded element
> when we could have.
>
> This patch adds an end_pt recalculation after new_data_start
> adjustment - we already know that size <= bound, so we can do it
> safely - and we then correctly report that we can, in fact, try
> using this element for bounded malloc allocation.
>
> Fixes: fafcc11985a2 ("mem: rework memzone to be allocated by malloc")
> Cc: sergio.gonzalez.monroy@intel.com
> Cc: stable@dpdk.org
> Signed-off-by: Anatoly Burakov <anatoly.burakov@intel.com>
It looks to be a headache, but as the maintainer of DPDK memory,
I trust you :)
Applied, thanks