From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ey0-f177.google.com ([209.85.215.177]) by canuck.infradead.org with esmtps (Exim 4.72 #1 (Red Hat Linux)) id 1PSWmi-0007G8-Bf for linux-mtd@lists.infradead.org; Tue, 14 Dec 2010 15:27:25 +0000 Received: by eyd9 with SMTP id 9so465660eyd.22 for ; Tue, 14 Dec 2010 07:27:19 -0800 (PST) Subject: Re: [PATCH 1/1] mtd: nand: add check for out of page read From: Artem Bityutskiy To: Jason Liu In-Reply-To: <1290156045-11719-1-git-send-email-r64343@freescale.com> References: <1290156045-11719-1-git-send-email-r64343@freescale.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 14 Dec 2010 17:26:49 +0200 Message-ID: <1292340409.2538.40.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: linux-mtd@lists.infradead.org, David.Woodhouse@intel.com, linux-kernel@vger.kernel.org Reply-To: dedekind1@gmail.com List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2010-11-19 at 16:40 +0800, Jason Liu wrote: > When run mtd_oobtest case, there will be one error for step(4), > which turned out it need add one check for out of page read in > nand_do_read_oob just like mtd_do_write_oob did it already. > This commit also fix one typo error for comments in mtd_do_write_oob > > Signed-off-by: Jason Liu I cannot reproduce this with nandsim, can you? I tried: 1. sudo modprobe nandsim sudo modprobe mtd_oobtest dev=0 2. sudo ./load_nandsim.sh 128 128 2048 sudo modprobe mtd_oobtest dev=0 In both cases the test passes: "mtd_oobtest: finished with 0 errors" And in 'nand_do_read_oob()' I see the following piece of code: /* Do not allow reads past end of device */ if (unlikely(from >= mtd->size || ops->ooboffs + readlen > ((mtd->size >> chip->page_shift) - (from >> chip->page_shift)) * len)) { DEBUG(MTD_DEBUG_LEVEL0, "%s: Attempt read beyond end " "of device\n", __func__); return -EINVAL; } which should handle the case AFAICS. So, although I did think hard about this, it looks like there is no problem. What is the kernel version you are looking at? I checked it with my l2-mtd-2.6.git, which is the latest mtd-2.6.git plus a revert commit of your patch: http://git.infradead.org/users/dedekind/l2-mtd-2.6.git -- Best Regards, Artem Bityutskiy (Артём Битюцкий)