Re: [PATCH] bnx2fc: shift wrapping bug in bnx2fc_process_unsol_compl()

Laurence Oberman
2016-11-28T17:05:50Z

----- Original Message -----
> From: "Christophe JAILLET" <christophe.jaillet@wanadoo.fr>
> To: QLogic-Storage-Upstream@qlogic.com, jejb@linux.vnet.ibm.com, "martin petersen" <martin.petersen@oracle.com>
> Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, "Christophe JAILLET"
> <christophe.jaillet@wanadoo.fr>
> Sent: Saturday, November 26, 2016 1:36:29 PM
> Subject: [PATCH] bnx2fc: shift wrapping bug in bnx2fc_process_unsol_compl()
>
> BNX2FC_NUM_ERR_BITS is 63. err_warn_bit_map is a u64. So, to make sure that
> no shift wrapping will occur, we need need additionnal casting.
>
> The same test is already done a few lines above and '(u64)1' is already
> used there. So just do the same here.
>
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> I guess that this could also be written with a '1ULL << i' which would be
> cleaner and less verbose IMHO, but apparently this driver does not use
> such things yet. So keep the current style with casting.
> ---
> drivers/scsi/bnx2fc/bnx2fc_hwi.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/bnx2fc/bnx2fc_hwi.c
> b/drivers/scsi/bnx2fc/bnx2fc_hwi.c
> index 5ff9f89c17c7..a9dccb3b49cc 100644
> --- a/drivers/scsi/bnx2fc/bnx2fc_hwi.c
> +++ b/drivers/scsi/bnx2fc/bnx2fc_hwi.c
> @@ -829,7 +829,7 @@ static void bnx2fc_process_unsol_compl(struct
> bnx2fc_rport *tgt, u16 wqe)
> ((u64)err_entry->data.err_warn_bitmap_hi << 32) |
> (u64)err_entry->data.err_warn_bitmap_lo;
> for (i = 0; i < BNX2FC_NUM_ERR_BITS; i++) {
> - if (err_warn_bit_map & (u64) (1 << i)) {
> + if (err_warn_bit_map & (u64)((u64)1 << i)) {
> err_warn = i;
> break;
> }
> --
> 2.9.3
>
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Looks fine to me.
Reviewed-by: Laurence Oberman <loberman@redhat.com>