Re: [PATCH] cxgb4: fix invalid checks in alloc_uld_rxqs

On 08/23/2016 09:46 AM, Hariprasad Shenai wrote:

On Tuesday, August 08/23/16, 2016 at 08:16:19 +0200, Andrzej Hajda wrote:

quoted

Local variable msi_idx defined as unsigned int is always >= 0, thus both
'if' checks are always true. On the other side presence of USING_MSIX flag
suggests the checks should not be trivially true.
The simplest solution is to replace incorrect checks with direct testing
of adap->flags and remove spare variables.

The problem has been detected using semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci

The correct fix is to have local variable 'msi_idx' as int instead of unsigned
int. Thanks for reporting the issue. Do you want me to send a V2?

Thanks,
Hari

If adap->flags is constant during the call I see no point in creating
separate

variable with complicated initialization used only for the same thing as

'adap->flags & USING_MSIX', and even if adap->flags changes during the call

much simpler would be to use local var:

    int using_msix = adap->flags & USING_MSIX;

and later use tests:

    if (using_msix)

        ...

Am I correct?


Regards

Andrzej