From: Colin Ian King <colin.king@canonical.com>
To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>,
kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, kernel-janitors@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH][next] vhost: only return early if ret indicates an error or no iovecs have been processed
Date: Tue, 19 Feb 2019 16:40:45 +0000 [thread overview]
Message-ID: <4145121c-83b8-e4a4-6c95-ee0151ac70c0@canonical.com> (raw)
In-Reply-To: <20190219113510-mutt-send-email-mst@kernel.org>
On 19/02/2019 16:35, Michael S. Tsirkin wrote:
> On Tue, Feb 19, 2019 at 01:57:13PM +0000, Colin King wrote:
>> From: Colin Ian King <colin.king@canonical.com>
>>
>> Currently the loop that calls log_write_hva on each iovec is never
>> executed because of an incorrect error check on the return from the
>> call to translate_desc. The check should be checking for a -ve error
>> return and because it makes no sense to iterate over zero items, the
>> checks should also check for zero too.
>>
>> Detected by CoverityScan, CID#1476969 ("Logically dead code")
>>
>> Fixes: cc5e71075947 ("vhost: log dirty page correctly")
>> Signed-off-by: Colin Ian King <colin.king@canonical.com>
>
> Jason posted a similar patch recently.
>
> Are you happy with that one?
Sure, ignore mine, I was late to the party.
>
>> ---
>> drivers/vhost/vhost.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
>> index 24a129fcdd61..a9a1709a859a 100644
>> --- a/drivers/vhost/vhost.c
>> +++ b/drivers/vhost/vhost.c
>> @@ -1788,7 +1788,7 @@ static int log_used(struct vhost_virtqueue *vq, u64 used_offset, u64 len)
>>
>> ret = translate_desc(vq, (uintptr_t)vq->used + used_offset,
>> len, iov, 64, VHOST_ACCESS_WO);
>> - if (ret)
>> + if (ret <= 0)
>> return ret;
>>
>> for (i = 0; i < ret; i++) {
>> --
>> 2.20.1
prev parent reply other threads:[~2019-02-19 16:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-19 13:57 [PATCH][next] vhost: only return early if ret indicates an error or no iovecs have been processed Colin King
2019-02-19 16:35 ` Michael S. Tsirkin
2019-02-19 16:40 ` Colin Ian King [this message]
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