From: David Laight <David.Laight@ACULAB.COM>
To: "'Tyrel Datwyler'" <tyreld@linux.vnet.ibm.com>,
"Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
"Michal Suchánek" <msuchanek@suse.de>,
"Ashley Lai" <ashleydlai@gmail.com>,
"Paul Mackerras" <paulus@samba.org>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Peter Huewe" <peterhuewe@gmx.de>,
"Marcel Selhorst" <tpmdd@selhorst.net>,
"Jarkko Sakkinen" <jarkko.sakkinen@linux.intel.com>,
"Jason Gunthorpe" <jgunthorpe@obsidianresearch.com>,
"tpmdd-devel@lists.sourceforge.net"
<tpmdd-devel@lists.sourceforge.net>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: ibmvtpm byteswapping inconsistency
Date: Mon, 30 Jan 2017 14:42:25 +0000 [thread overview]
Message-ID: <063D6719AE5E284EB5DD2968C1650D6DB0273BCA@AcuExch.aculab.com> (raw)
In-Reply-To: <e518682f-e563-9533-9ffd-f465c662e998@linux.vnet.ibm.com>
From: Tyrel Datwyler
> Sent: 27 January 2017 18:03
> On 01/26/2017 05:50 PM, Benjamin Herrenschmidt wrote:
> > On Thu, 2017-01-26 at 17:42 -0800, Tyrel Datwyler wrote:
> >> On 01/26/2017 12:22 PM, Michal Suchnek wrote:
> >>> Hello,
> >>>
> >>> building ibmvtpm I noticed gcc warning complaining that second word
> >>> of
> >>> struct ibmvtpm_crq in tpm_ibmvtpm_suspend is uninitialized.
> >>>
> >>> The structure is defined as
> >>>
> >>> struct ibmvtpm_crq {
> >>> u8 valid;
> >>> u8 msg;
> >>> __be16 len;
> >>> __be32 data;
> >>> __be64 reserved;
> >>> } __attribute__((packed, aligned(8)));
> >>>
> >>> initialized as
> >>>
> >>> struct ibmvtpm_crq crq;
> >>> u64 *buf = (u64 *) &crq;
> >>> ...
> >>> crq.valid = (u8)IBMVTPM_VALID_CMD;
> >>> crq.msg = (u8)VTPM_PREPARE_TO_SUSPEND;
> >>>
> >>> and submitted with
> >>>
> >>> rc = ibmvtpm_send_crq(ibmvtpm->vdev, cpu_to_be64(buf[0]),
> >>> cpu_to_be64(buf[1]));
Isn't the real fubar here the use of that memory layout structure at all?
It would probably all be better if the call looked like:
rc = ibmvtpm_send_crq(ibmvtpm->vdev, MAKE_REQ(IBMVTPM_VALID_CMD,
VTPM_PREPARE_TO_SUSPEND, xxx_len, xxx_data), 0);
and MAKE_REQ() did all the required endian independant shifts to generate
the correct 32bit value.
David
next prev parent reply other threads:[~2017-01-30 14:42 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-26 20:22 ibmvtpm byteswapping inconsistency Michal Suchánek
2017-01-26 22:05 ` Jason Gunthorpe
2017-01-26 22:43 ` Michal Suchanek
2017-01-26 22:58 ` Ashley Lai
2017-02-02 4:40 ` Vicky
2017-02-02 10:55 ` Michael Ellerman
2017-02-02 11:29 ` Michal Suchánek
2017-02-02 15:17 ` David Laight
2017-01-27 1:42 ` Tyrel Datwyler
2017-01-27 1:50 ` Benjamin Herrenschmidt
2017-01-27 9:03 ` Michal Suchanek
2017-01-27 21:19 ` Tyrel Datwyler
2017-01-30 4:32 ` Michael Ellerman
2017-01-30 20:34 ` Tyrel Datwyler
2017-01-31 8:38 ` Michael Ellerman
2017-01-27 18:02 ` Tyrel Datwyler
2017-01-27 19:58 ` Benjamin Herrenschmidt
2017-01-27 20:32 ` Tyrel Datwyler
2017-01-28 0:35 ` msuchanek
2017-01-28 4:28 ` Benjamin Herrenschmidt
2017-01-30 14:42 ` David Laight [this message]
2017-01-27 11:18 ` David Laight
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