On 06/03/2019 04:34 PM, Tyrel Datwyler wrote:
> On 06/03/2019 04:25 PM, Tyrel Datwyler wrote:
>> On 06/03/2019 03:19 PM, Nathan Chancellor wrote:
>>> clang warns:
>>>
>>> drivers/scsi/ibmvscsi/ibmvscsi.c:2126:7: warning: variable 'rc' is used
>>> uninitialized whenever switch case is taken [-Wsometimes-uninitialized]
>>> case IBMVSCSI_HOST_ACTION_NONE:
>>> ^~~~~~~~~~~~~~~~~~~~~~~~~
>>> drivers/scsi/ibmvscsi/ibmvscsi.c:2151:6: note: uninitialized use occurs
>>> here
>>> if (rc) {
>>> ^~
>>>
>>> Initialize rc to zero in the case statements that clang mentions so that
>>> the atomic_set and dev_err statement don't trigger for them.
>>>
>>> Fixes: 035a3c4046b5 ("scsi: ibmvscsi: redo driver work thread to use enum action states")
>>> Link: https://github.com/ClangBuiltLinux/linux/issues/502
>>> Suggested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
>>> Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
>>
>> Acked-by: Tyrel Datwyler <tyreld@xxxxxxxxxxxxx>
>>
>
> On second thought NACK. See my response to Michael earlier in the thread.
>
> I think this is the better solution:
>
> diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
> index 727c31dc11a0..c3cf05dd8733 100644
> --- a/drivers/scsi/ibmvscsi/ibmvscsi.c
> +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
> @@ -2123,8 +2123,8 @@ static void ibmvscsi_do_work(struct ibmvscsi_host_data
> *hostdata)
>
> spin_lock_irqsave(hostdata->host->host_lock, flags);
> switch (hostdata->action) {
> - case IBMVSCSI_HOST_ACTION_NONE:
> case IBMVSCSI_HOST_ACTION_UNBLOCK:
> + rc = 0;
> break;
> case IBMVSCSI_HOST_ACTION_RESET:
> spin_unlock_irqrestore(hostdata->host->host_lock, flags);
> @@ -2142,8 +2142,9 @@ static void ibmvscsi_do_work(struct ibmvscsi_host_data
> *hostdata)
> if (!rc)
> rc = ibmvscsi_send_crq(hostdata, 0xC001000000000000LL, 0);
> break;
> + case IBMVSCSI_HOST_ACTION_NONE:
> default:
> - break;
Need a spin_unlock_irqrestore() here before the return.
-Tyrel
> + return;
> }
>
> hostdata->action = IBMVSCSI_HOST_ACTION_NONE;
>
