From: Hemant Agrawal <hemant.agrawal@nxp.com>
To: Andy Green <andy@warmcat.com>, "dev@dpdk.org" <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH v2 03/18] drivers/bus/dpaa: fix inconsistent struct alignment
Date: Wed, 9 May 2018 08:06:31 +0000 [thread overview]
Message-ID: <AM2PR04MB0753949363608CBEC42F937689990@AM2PR04MB0753.eurprd04.prod.outlook.com> (raw)
In-Reply-To: <152582946580.6809.14461590402993659685.stgit@localhost.localdomain>
On 5/9/2018 7:01 AM, Andy Green wrote:
> The actual descriptor for qm_mr_entry is 64-byte aligned.
>
> But the original code plays a trick, and puts a u8 common
> to the three descriptor subtypes in the union afterwards
> outside their structure definitions.
>
> Unfortunately since they compose a struct qm_fd with
> alignment 8, this trick destroys the ability of the compiler
> to understand what has happened, resulting in this kind of
> problem:
>
> /home/agreen/projects/dpdk/drivers/bus/dpaa/include/
> fsl_qman.h:354:3: error: alignment 1 of ‘struct <anonymous>’
> is less than 8 [-Werror=packed-not-aligned]
> } __packed dcern;
>
> on gcc 8 / Fedora 28 out of the box.
>
> This patch moves the u8 verb into the structure definitions
> composed into the union, so the alignment of the parent struct
> containing the alignment 8 object can also be seen to be
> alignment 8 by the compiler. Uses of .verb are fixed up to use
> .ern.verb (the same offset of +0 inside all the structs in
> the union).
>
> The final struct layout should be unchanged.
>
> Signed-off-by: Andy Green <andy@warmcat.com>
> ---
> drivers/bus/dpaa/base/qbman/qman.c | 14 +++++++-------
> drivers/bus/dpaa/include/fsl_qman.h | 24 +++++++++++++-----------
> 2 files changed, 20 insertions(+), 18 deletions(-)
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
Tested on ubuntu 18.04 with GCC 8.1.0
next prev parent reply other threads:[~2018-05-09 8:07 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-09 1:30 [dpdk-dev] [PATCH v2 00/18] Fix build on gcc8 and various bugs Andy Green
2018-05-09 1:30 ` [dpdk-dev] [PATCH v2 01/18] lib/libtre_table: workaround hash function cast error Andy Green
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 02/18] drivers/bus/pci: fix strncpy dangerous code Andy Green
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 03/18] drivers/bus/dpaa: fix inconsistent struct alignment Andy Green
2018-05-09 8:06 ` Hemant Agrawal [this message]
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 04/18] drivers/net/axgbe: fix broken eeprom string comp Andy Green
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 05/18] drivers/net/nfp/nfpcore: fix strncpy misuse Andy Green
2018-05-09 9:49 ` Alejandro Lucero
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 06/18] drivers/net/nfp/nfpcore: fix off-by-one and no NUL on strncpy use Andy Green
2018-05-09 9:53 ` Alejandro Lucero
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 07/18] drivers/net/nfp: don't memcpy out of source range Andy Green
2018-05-09 9:54 ` Alejandro Lucero
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 08/18] drivers/net/nfp: fix buffer overflow in fw_name Andy Green
2018-05-09 10:04 ` Alejandro Lucero
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 09/18] drivers/net/qede: fix strncpy constant and NUL Andy Green
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 10/18] drivers/net/qede: fix broken strncpy Andy Green
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 11/18] drivers/net/sfc: fix strncpy length Andy Green
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 12/18] drivers/net/sfc: fix strncpy size and NUL Andy Green
2018-05-09 1:31 ` [dpdk-dev] [PATCH v2 13/18] drivers/net/vdev: readlink inputs cannot be aliased Andy Green
2018-05-09 15:33 ` Stephen Hemminger
2018-05-09 1:32 ` [dpdk-dev] [PATCH v2 14/18] drivers/net/vdev: fix 3 x strncpy misuse Andy Green
2018-05-09 1:32 ` [dpdk-dev] [PATCH v2 15/18] app/test-pmd: can't find include Andy Green
2018-05-09 1:32 ` [dpdk-dev] [PATCH v2 16/18] app/proc-info: fix sprintf overrun bug Andy Green
2018-05-09 1:32 ` [dpdk-dev] [PATCH v2 17/18] app/test-bbdev: test-bbdev: strcpy ok for allocated string Andy Green
2018-05-09 1:32 ` [dpdk-dev] [PATCH v2 18/18] app/test-bbdev: " Andy Green
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