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References: <20220620085413.948265-1-hpa@redhat.com> <YrA3RffyR9VT0DjN@kroah.com>
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From:   Kate Hsuan <hpa@redhat.com>
Date:   Mon, 20 Jun 2022 17:25:37 +0800
Message-ID: <CAEth8oGSOXpEN883QMxU9b++GB27pG8tbCjvdg9GaZkUOzFwWw@mail.gmail.com>
Subject: Re: [PATCH v1] staging: r8188eu: an incorrect return value made the
 function always return fail
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Hans de Goede <hdegoede@redhat.com>,
        Larry Finger <Larry.Finger@lwfinger.net>,
        Phillip Potter <phil@philpotter.co.uk>,
        Michael Straube <straube.linux@gmail.com>,
        "Fabio M . De Francesco" <fmdefrancesco@gmail.com>,
        linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
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On Mon, Jun 20, 2022 at 5:01 PM Greg Kroah-Hartman
<gregkh@linuxfoundation.org> wrote:
>
> On Mon, Jun 20, 2022 at 04:54:13PM +0800, Kate Hsuan wrote:
> > Since _SUCCESS (1) and _FAIL (0) are used to indicate the status of the
> > functions. The previous commit 8ae7bf782eacad803f752c83a183393b0a67127b
>
> In the future, please reference commit ids as the documentation asks, as
> it's a much nicer way to understand things.  Also this commit id is not
> in Linus's tree or any tree that I can see, where did it come from?

Sorry about this. I'll improve this in my v2 patch.

>
> > fixed and prevented dereferencing a NULL pointer through checking the
> > return pointer. The NULL pointer check work properly but the return
> > values (-ENOMEM on fail and 0 on success). This work fixed the return
> > values to make sure the caller function will return the correct status.
> >
> > BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=2097526
> > Signed-off-by: Kate Hsuan <hpa@redhat.com>
> > ---
> >  drivers/staging/r8188eu/core/rtw_xmit.c | 8 +++-----
> >  1 file changed, 3 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/staging/r8188eu/core/rtw_xmit.c b/drivers/staging/r8188eu/core/rtw_xmit.c
> > index f4e9f6102539..2f8720db21d9 100644
> > --- a/drivers/staging/r8188eu/core/rtw_xmit.c
> > +++ b/drivers/staging/r8188eu/core/rtw_xmit.c
> > @@ -180,10 +180,8 @@ s32      _rtw_init_xmit_priv(struct xmit_priv *pxmitpriv, struct adapter *padapter)
> >       pxmitpriv->free_xmit_extbuf_cnt = num_xmit_extbuf;
> >
> >       res = rtw_alloc_hwxmits(padapter);
> > -     if (res) {
> > -             res = _FAIL;
> > +     if (res == _FAIL)
> >               goto exit;
> > -     }
> >
> >       rtw_init_hwxmits(pxmitpriv->hwxmits, pxmitpriv->hwxmit_entry);
> >
> > @@ -1510,7 +1508,7 @@ int rtw_alloc_hwxmits(struct adapter *padapter)
> >
> >       pxmitpriv->hwxmits = kzalloc(sizeof(struct hw_xmit) * pxmitpriv->hwxmit_entry, GFP_KERNEL);
> >       if (!pxmitpriv->hwxmits)
> > -             return -ENOMEM;
> > +             return _FAIL;
>
> No, please let's fix up the callers to properly detect normal kernel
> error values and get rid of all of the crazy _FAIL and _SUCCESS values
> in this driver.

Okay.

>
> >
> >       hwxmits = pxmitpriv->hwxmits;
> >
> > @@ -1528,7 +1526,7 @@ int rtw_alloc_hwxmits(struct adapter *padapter)
> >       } else {
> >       }
> >
> > -     return 0;
> > +     return _SUCCESS;
>
> Same here, fix up the callers if they are checking this incorrectly.
>
> thanks,
>
> greg k-h
>

Thank you :)

-- 
BR,
Kate