On 2016/10/27 12:02, Gao Feng wrote:
> On Thu, Oct 27, 2016 at 11:56 AM, zhongjiang <zhongji...@huawei.com> wrote:
>> From: zhong jiang <zhongji...@huawei.com>
>>
>> when I compiler the newest kernel, I hit the following error with
>> Werror=may-uninitalized.
>>
>> net/core/flow_dissector.c: In function ?._skb_flow_dissect?
>> include/uapi/linux/swab.h:100:46: error: ?.lan?.may be used uninitialized in
>> this function [-Werror=maybe-uninitialized]
>> net/core/flow_dissector.c:248:26: note: ?.lan?.was declared here
>>
>> This adds an additional check for proto to explicitly tell the compiler
>> that vlan pointer have the correct value before it is used.
>>
>> Signed-off-by: zhong jiang <zhongji...@huawei.com>
>> ---
>> net/core/flow_dissector.c | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
>> index 1a7b80f..a04d9cf 100644
>> --- a/net/core/flow_dissector.c
>> +++ b/net/core/flow_dissector.c
>> @@ -245,7 +245,7 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
>> }
>> case htons(ETH_P_8021AD):
>> case htons(ETH_P_8021Q): {
>> - const struct vlan_hdr *vlan;
>> + const struct vlan_hdr *vlan = NULL;
>>
>> if (skb_vlan_tag_present(skb))
>> proto = skb->protocol;
>> @@ -276,7 +276,8 @@ bool __skb_flow_dissect(const struct sk_buff *skb,
>> key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
>> key_vlan->vlan_priority =
>> (skb_vlan_tag_get_prio(skb) >>
>> VLAN_PRIO_SHIFT);
>> - } else {
>> + } else if (proto == cpu_to_be16(ETH_P_8021Q) ||
>> + proto ==
>> cpu_to_be16(ETH_P_8021AD)) {
>> key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
>> VLAN_VID_MASK;
>> key_vlan->vlan_priority =
>> --
>> 1.8.3.1
>>
> It seems there is one similar patch already.
> You could refer to https://patchwork.kernel.org/patch/9389565/
>
> Regards
> Feng
>
> .
>
sorry, I doesn't notice that patch.
Thanks
zhongjiang
