From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751981AbbIORWc (ORCPT ); Tue, 15 Sep 2015 13:22:32 -0400 Received: from quartz.orcorp.ca ([184.70.90.242]:34412 "EHLO quartz.orcorp.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751567AbbIORWb (ORCPT ); Tue, 15 Sep 2015 13:22:31 -0400 Date: Tue, 15 Sep 2015 11:22:27 -0600 From: Jason Gunthorpe To: Jarkko Sakkinen Cc: tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Peter Huewe , Marcel Selhorst Subject: Re: [PATCH v3] tpm, tpm_crb: fix unaligned read of the command buffer address Message-ID: <20150915172227.GA24173@obsidianresearch.com> References: <1442336740-9383-1-git-send-email-jarkko.sakkinen@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1442336740-9383-1-git-send-email-jarkko.sakkinen@linux.intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-Broken-Reverse-DNS: no host name found for IP address 10.0.0.160 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 15, 2015 at 08:05:40PM +0300, Jarkko Sakkinen wrote: > The command buffer address must be read with exactly two 32-bit reads. > Otherwise, on some HW platforms, it seems that HW will abort the read > operation, which causes CPU to fill the read bytes with 1's. Therefore, > we cannot rely on memcpy_fromio() but must call ioread32() two times > instead. > > Also, this matches the PC Client Platform TPM Profile specification, > which defines command buffer address with two 32-bit fields. > > Signed-off-by: Jarkko Sakkinen > drivers/char/tpm/tpm_crb.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c > index b4564b6..c09b370 100644 > +++ b/drivers/char/tpm/tpm_crb.c > @@ -68,7 +68,8 @@ struct crb_control_area { > u32 int_enable; > u32 int_sts; > u32 cmd_size; > - u64 cmd_pa; > + u32 cmd_pa_low; > + u32 cmd_pa_high; > u32 rsp_size; > u64 rsp_pa; What about rsp_pa? > } __packed; As I mentioned, drop the __packed. Otherwise: Reviewed-By: Jason Gunthorpe Jason