On 16.3.2016 16:03, Tomas Henzl wrote:
> On 15.3.2016 22:40, Arnd Bergmann wrote:
>> The qlt_check_reserve_free_req() function produces an incorrect warning
>> when CONFIG_PROFILE_ANNOTATED_BRANCHES is set:
>>
>> drivers/scsi/qla2xxx/qla_target.c: In function 'qlt_check_reserve_free_req':
>> drivers/scsi/qla2xxx/qla_target.c:1887:3: error: 'cnt_in' may be used
>> uninitialized in this function [-Werror=maybe-uninitialized]
>> ql_dbg(ql_dbg_io, vha, 0x305a,
>> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> "qla_target(%d): There is no room in the request ring:
>> vha->req->ring_index=%d, vha->req->cnt=%d, req_cnt=%d Req-out=%d Req-in=%d
>> Req-Length=%d\n",
>>
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> vha->vp_idx, vha->req->ring_index,
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> vha->req->cnt, req_cnt, cnt, cnt_in, vha->req->length);
>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/scsi/qla2xxx/qla_target.c:1887:3: error: 'cnt' may be used
>> uninitialized in this function [-Werror=maybe-uninitialized]
>>
>> The problem is that gcc fails to track the state of the condition across
>> an annotated branch.
>>
>> This slightly rearranges the code to move the second if() block
>> into the first one, to avoid the warning while retaining the
>> behavior of the code.
> When the first 'if' is true the vha->req->ring_index gets a new value
> assigned - so it could be possible that the second 'if' wont be true any more.
> The code should not be merged into that single 'if', or am I missing
> something?
Oh, I haven't noticed that the second if actually remained in place
- please ignore my previous comments.
>
> tomash
>
>> Signed-off-by: Arnd Bergmann <a...@arndb.de>
>> ---
>> drivers/scsi/qla2xxx/qla_target.c | 16 +++++++++-------
>> 1 file changed, 9 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/scsi/qla2xxx/qla_target.c
>> b/drivers/scsi/qla2xxx/qla_target.c
>> index 985231900aca..8a44d1541eb4 100644
>> --- a/drivers/scsi/qla2xxx/qla_target.c
>> +++ b/drivers/scsi/qla2xxx/qla_target.c
>> @@ -1881,15 +1881,17 @@ static int qlt_check_reserve_free_req(struct
>> scsi_qla_host *vha,
>> else
>> vha->req->cnt = vha->req->length -
>> (vha->req->ring_index - cnt);
>> - }
>>
>> - if (unlikely(vha->req->cnt < (req_cnt + 2))) {
>> - ql_dbg(ql_dbg_io, vha, 0x305a,
>> - "qla_target(%d): There is no room in the request ring:
>> vha->req->ring_index=%d, vha->req->cnt=%d, req_cnt=%d Req-out=%d Req-in=%d
>> Req-Length=%d\n",
>> - vha->vp_idx, vha->req->ring_index,
>> - vha->req->cnt, req_cnt, cnt, cnt_in, vha->req->length);
>> - return -EAGAIN;
>> + if (unlikely(vha->req->cnt < (req_cnt + 2))) {
>> + ql_dbg(ql_dbg_io, vha, 0x305a,
>> + "qla_target(%d): There is no room in the request
>> ring: vha->req->ring_index=%d, vha->req->cnt=%d, req_cnt=%d Req-out=%d
>> Req-in=%d Req-Length=%d\n",
>> + vha->vp_idx, vha->req->ring_index,
>> + vha->req->cnt, req_cnt, cnt, cnt_in,
>> + vha->req->length);
>> + return -EAGAIN;
>> + }
>> }
>> +
>> vha->req->cnt -= req_cnt;
>>
>> return 0;
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majord...@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
