Re: [PATCH, resend] scsi: advansys: fix big-endian builds

From: Hannes Reinecke
Date: Tue Nov 17 2015 - 01:46:10 EST


On 11/16/2015 05:49 PM, Arnd Bergmann wrote:
> Building the advansys driver in a big-endian configuration such as
> ARM allmodconfig shows a warning:
>
> drivers/scsi/advansys.c: In function 'adv_build_req':
> include/uapi/linux/byteorder/big_endian.h:32:26: warning: large integer implicitly truncated to unsigned type [-Woverflow]
> #define __cpu_to_le32(x) ((__force __le32)__swab32((x)))
> drivers/scsi/advansys.c:7806:22: note: in expansion of macro 'cpu_to_le32'
> scsiqp->sense_len = cpu_to_le32(SCSI_SENSE_BUFFERSIZE);
>
> It turns out that the commit that introduced this used the cpu_to_le32()
> incorrectly on an 8-bit field, which results in the sense_len to always
> be set to zero, as the SCSI_SENSE_BUFFERSIZE value gets moved to upper
> byte of the 32-bit intermediate.
>
> This removes the cpu_to_le32() call to restore the original version.
>
> I found this only by looking at the compiler output and have not done
> a full review for possible further endianess bugs in the same driver.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Fixes: 811ddc057aac ("advansys: use DMA-API for mapping sense buffer")
> Cc: stable@xxxxxxxxxxxxxxx # v4.2+
> ---
> Using willy@xxxxxxxxxxxxxxx, as the address listed in MAINTAINERS
> failed:
>
> Failed to transport message. Message sending failed since the following recipients were rejected by the server: matthew@xxxxxx (The server responded: Requested action not taken: mailbox unavailable invalid DNS MX or A/AAAA resource record)
>
> Geert found the same bug and submitted the same patch earlier:
> https://lkml.org/lkml/2015/6/24/89
>
> Neither one has been reviewed or accepted so far. Can we get one of the
> two merged please?
>
> diff --git a/drivers/scsi/advansys.c b/drivers/scsi/advansys.c
> index 4305178e4e01..1c1cd657c380 100644
> --- a/drivers/scsi/advansys.c
> +++ b/drivers/scsi/advansys.c
> @@ -7803,7 +7803,7 @@ adv_build_req(struct asc_board *boardp, struct scsi_cmnd *scp,
> return ASC_BUSY;
> }
> scsiqp->sense_addr = cpu_to_le32(sense_addr);
> - scsiqp->sense_len = cpu_to_le32(SCSI_SENSE_BUFFERSIZE);
> + scsiqp->sense_len = SCSI_SENSE_BUFFERSIZE;
>
> /* Build ADV_SCSI_REQ_Q */
>
>
Ho-hum. You are right.

Reviewed-by: Hannes Reinecke <hare@xxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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HRB 21284 (AG Nürnberg)
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