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Groups > linux.kernel > #1719602
| From | David Miller <davem@davemloft.net> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH][next] net: hinic: fix comparison of a uint16_t type with -1 |
| Date | 2017-08-24 23:40 +0200 |
| Message-ID | <ui813-3xK-9@gated-at.bofh.it> (permalink) |
| References | <uhFV7-2iZ-17@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
From: Colin King <colin.king@canonical.com>
Date: Wed, 23 Aug 2017 16:39:36 +0100
> From: Colin Ian King <colin.king@canonical.com>
>
> The comparison of hw_ioctxt.rx_buf_sz_idx == -1 is always false because
> rx_buf_sz_idx is a uint16_t. Fix this by explicitly casting -1 to uint16_t.
>
> Detected by CoverityScan, CID#1454559 ("Operands don't affect result")
>
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
> drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c b/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c
> index 09dec6de8dd5..71e26070fb7f 100644
> --- a/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c
> +++ b/drivers/net/ethernet/huawei/hinic/hinic_hw_dev.c
> @@ -352,7 +352,7 @@ static int set_hw_ioctxt(struct hinic_hwdev *hwdev, unsigned int rq_depth,
> }
> }
>
> - if (hw_ioctxt.rx_buf_sz_idx == -1)
> + if (hw_ioctxt.rx_buf_sz_idx == (uint16_t)-1)
> return -EINVAL;
>
> hw_ioctxt.sq_depth = ilog2(sq_depth);
This is really silly.
The code in question is trying to convert a size (HINIC_RX_BUF_SZ)
into a table index, using a loop.
It should just compute this at compile time and do away with this
overly confusing code.
Even a switch statement would be much better and the compiler
would optimize the whole away into a single assignment in
the generated code.
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[PATCH][next] net: hinic: fix comparison of a uint16_t type with -1 Colin King <colin.king@canonical.com> - 2017-08-23 17:40 +0200
Re: [PATCH][next] net: hinic: fix comparison of a uint16_t type with -1 Aviad Krawczyk <aviad.krawczyk@huawei.com> - 2017-08-24 10:50 +0200
Re: [PATCH][next] net: hinic: fix comparison of a uint16_t type with -1 Colin Ian King <colin.king@canonical.com> - 2017-08-24 11:00 +0200
Re: [PATCH][next] net: hinic: fix comparison of a uint16_t type with -1 Dan Carpenter <dan.carpenter@oracle.com> - 2017-08-24 11:40 +0200
Re: [PATCH][next] net: hinic: fix comparison of a uint16_t type with -1 Aviad Krawczyk <aviad.krawczyk@huawei.com> - 2017-08-24 11:40 +0200
Re: [PATCH][next] net: hinic: fix comparison of a uint16_t type with -1 David Miller <davem@davemloft.net> - 2017-08-24 23:40 +0200
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