linux-kernel - Re: [PATCH] staging: r8188eu: remove unnecessary NULL check

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Message-ID: <CAH1kMwRPLP998GjKx7bkL_LQE8hVNdCThwBJ7W8iNo1mPUyEZQ@mail.gmail.com>
Date:   Thu, 25 Nov 2021 07:02:20 +0530
From:   Vihas Mak <makvihas@...il.com>
To:     Greg KH <gregkh@...uxfoundation.org>
Cc:     Larry.Finger@...inger.net, Phillip Potter <phil@...lpotter.co.uk>,
        straube.linux@...il.com, martin@...ser.cx,
        Pavel Skripkin <paskripkin@...il.com>,
        linux-staging@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] staging: r8188eu: remove unnecessary NULL check

>> And are you sure this ever could be NULL?
Yes.

The function rtw_free_netdev() performs a NULL check before actually
freeing the structure, so the "if (pnetdev)" check isn't really
necessary before calling rtw_free_netdev().
That's the reason why I removed that check.


On Wed, Nov 24, 2021 at 3:30 PM Greg KH <gregkh@...uxfoundation.org> wrote:
>
> On Tue, Nov 23, 2021 at 01:23:50AM +0530, Vihas Mak wrote:
> > remove unnecessary NULL check surrounding rtw_free_netdev(), as the check
> > is already performed inside rtw_free_netdev() in
> > drivers/staging/r8188eu/os_dep/osdep_service.c.
> >
> > Signed-off-by: Vihas Mak <makvihas@...il.com>
> > ---
> >  drivers/staging/r8188eu/os_dep/usb_intf.c | 3 +--
> >  1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/drivers/staging/r8188eu/os_dep/usb_intf.c b/drivers/staging/r8188eu/os_dep/usb_intf.c
> > index 5a35d9fe3fc9..392bd7868519 100644
> > --- a/drivers/staging/r8188eu/os_dep/usb_intf.c
> > +++ b/drivers/staging/r8188eu/os_dep/usb_intf.c
> > @@ -466,8 +466,7 @@ static void rtw_usb_if1_deinit(struct adapter *if1)
> >               if1->hw_init_completed);
> >       rtw_handle_dualmac(if1, 0);
> >       rtw_free_drv_sw(if1);
> > -     if (pnetdev)
> > -             rtw_free_netdev(pnetdev);
> > +     rtw_free_netdev(pnetdev);
>
> As Dan said, this isn't usually a good idea to hide this.
>
> And are you sure this ever could be NULL?
>
> thanks,
>
> greg k-h



-- 
Thanks,
Vihas