In function rtw_free_netdev() there are two "goto" jumps to a no-op exit
label called "RETURN". Remove the label and return in line.
Signed-off-by: Fabio M. De Francesco <[email protected]>
---
drivers/staging/r8188eu/os_dep/osdep_service.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/drivers/staging/r8188eu/os_dep/osdep_service.c b/drivers/staging/r8188eu/os_dep/osdep_service.c
index 7a6fcc96081a..d680bfba7f5d 100644
--- a/drivers/staging/r8188eu/os_dep/osdep_service.c
+++ b/drivers/staging/r8188eu/os_dep/osdep_service.c
@@ -117,18 +117,15 @@ void rtw_free_netdev(struct net_device *netdev)
struct rtw_netdev_priv_indicator *pnpi;
if (!netdev)
- goto RETURN;
+ return;
pnpi = netdev_priv(netdev);
if (!pnpi->priv)
- goto RETURN;
+ return;
vfree(pnpi->priv);
free_netdev(netdev);
-
-RETURN:
- return;
}
int rtw_change_ifname(struct adapter *padapter, const char *ifname)
--
2.34.1
On venerd? 1 aprile 2022 22:41:40 CEST Ira Weiny wrote:
> On Fri, Apr 01, 2022 at 08:35:13PM +0200, Fabio M. De Francesco wrote:
> > In function rtw_free_netdev() there are two "goto" jumps to a no-op exit
> > label called "RETURN". Remove the label and return in line.
>
> Thanks for the patch! However, A good commit message lists the why and what of
> a change. I don't see a why for this commit?
Yes I forgot the "why" :(
I'll rework the commit message for v2.
>
> FWIW (For what it's worth) I know of a couple of good reasons for this change
> but you should get in the habit of putting that in the commit message. Even
> for obvious things like this.
>
> Anyway, I think this patch can stand on it's own with an updated commit
> message. However, see below...
>
> >
> > Signed-off-by: Fabio M. De Francesco <[email protected]>
> > ---
> > drivers/staging/r8188eu/os_dep/osdep_service.c | 7 ++-----
> > 1 file changed, 2 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/staging/r8188eu/os_dep/osdep_service.c b/drivers/staging/r8188eu/os_dep/osdep_service.c
> > index 7a6fcc96081a..d680bfba7f5d 100644
> > --- a/drivers/staging/r8188eu/os_dep/osdep_service.c
> > +++ b/drivers/staging/r8188eu/os_dep/osdep_service.c
> > @@ -117,18 +117,15 @@ void rtw_free_netdev(struct net_device *netdev)
> > struct rtw_netdev_priv_indicator *pnpi;
> >
> > if (!netdev)
> > - goto RETURN;
> > + return;
Actually this function doesn't need to test for a valid "netdev". There are only
two callers of this function (they are in os_dep/usb_intf.c) and they already test
the pointer soon before calling rtw_free_netdev().
Therefore, I'll remove the test for a valid "netdev" and (obviously) the code has
no more need to return at that point in function.
> >
> > pnpi = netdev_priv(netdev);
> >
> > if (!pnpi->priv)
> > - goto RETURN;
> > + return;
I cannot see how pnpi->priv might ever be NULL. Pavel Skripkin made me notice
that "in rtw_alloc_etherdev() (I can confirm this information because now I've
just read the code), if pnpi->priv allocation fails, then netdev will
be just freed.". If "netdev" is already free, this function is never called.
Therefore, I'll remove this test too.
> This does not look right. If netdev is not NULL why does this function skip
> free_netdev()?
After the two removals I've talked about above, the code will always call
vfree(pnpi->priv) and then free_netdev(netdev).
Therefore, the code won't anymore skip free_netdev() and the bug is avoided.
>
> Fabio could you follow up with Larry and/or Phillip and see why the code does
> this? To me it looks like a potential bug.
>
> Thanks!
> Ira
>
> >
> > vfree(pnpi->priv);
> > free_netdev(netdev);
> > -
> > -RETURN:
> > - return;
> > }
> >
> > int rtw_change_ifname(struct adapter *padapter, const char *ifname)
> > --
> > 2.34.1
> >
>
This is how I think to rework rtw_free_netdev():
void rtw_free_netdev(struct net_device *netdev)
{
struct rtw_netdev_priv_indicator *pnpi = netdev_priv(netdev);
vfree(pnpi->priv);
free_netdev(netdev);
}
Am I missing something?
@Greg: please discard this patch; I'll send another that has the purpose
to rework rtw_free_netdev() as I showed above for the purpose to avoid
redundant tests and avoid the potential skipping of free_netdev() (as Ira
has correctly noted, currently we have a bug).
Thanks,
Fabio
Thus wrote Fabio M. De Francesco ([email protected]):
> > > pnpi = netdev_priv(netdev);
> > > if (!pnpi->priv)
> > > - goto RETURN;
> > > + return;
> I cannot see how pnpi->priv might ever be NULL.
Even if pnpi->priv was NULL, we wouldn't need the check. It's ok to call
vfree(NULL).
> After the two removals I've talked about above, the code will always call
> vfree(pnpi->priv) and then free_netdev(netdev).
That makes sense.
Best regards,
Martin
On sabato 2 aprile 2022 13:45:33 CEST Martin Kaiser wrote:
> Thus wrote Fabio M. De Francesco ([email protected]):
>
> > > > pnpi = netdev_priv(netdev);
>
> > > > if (!pnpi->priv)
> > > > - goto RETURN;
> > > > + return;
>
> > I cannot see how pnpi->priv might ever be NULL.
>
> Even if pnpi->priv was NULL, we wouldn't need the check. It's ok to call
> vfree(NULL).
>
> > After the two removals I've talked about above, the code will always call
> > vfree(pnpi->priv) and then free_netdev(netdev).
>
> That makes sense.
>
> Best regards,
> Martin
>
Hi Martin,
Thanks for reminding to me that a vfree() on a NULL pointer is a no-op.
I'm going to submit a new patch with the purpose to re-work rtw_free_netdev().
Thanks again,
Fabio
On Fri, Apr 01, 2022 at 01:41:40PM -0700, Ira Weiny wrote:
> On Fri, Apr 01, 2022 at 08:35:13PM +0200, Fabio M. De Francesco wrote:
> > In function rtw_free_netdev() there are two "goto" jumps to a no-op exit
> > label called "RETURN". Remove the label and return in line.
>
> Thanks for the patch! However, A good commit message lists the why and what of
> a change. I don't see a why for this commit?
People, stop belly aching about commit messages.
"Delete no-op goto" is sufficient justification.
regards,
dan carpenter
On Fri, Apr 01, 2022 at 08:35:13PM +0200, Fabio M. De Francesco wrote:
> In function rtw_free_netdev() there are two "goto" jumps to a no-op exit
> label called "RETURN". Remove the label and return in line.
Thanks for the patch! However, A good commit message lists the why and what of
a change. I don't see a why for this commit?
FWIW (For what it's worth) I know of a couple of good reasons for this change
but you should get in the habit of putting that in the commit message. Even
for obvious things like this.
Anyway, I think this patch can stand on it's own with an updated commit
message. However, see below...
>
> Signed-off-by: Fabio M. De Francesco <[email protected]>
> ---
> drivers/staging/r8188eu/os_dep/osdep_service.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/staging/r8188eu/os_dep/osdep_service.c b/drivers/staging/r8188eu/os_dep/osdep_service.c
> index 7a6fcc96081a..d680bfba7f5d 100644
> --- a/drivers/staging/r8188eu/os_dep/osdep_service.c
> +++ b/drivers/staging/r8188eu/os_dep/osdep_service.c
> @@ -117,18 +117,15 @@ void rtw_free_netdev(struct net_device *netdev)
> struct rtw_netdev_priv_indicator *pnpi;
>
> if (!netdev)
> - goto RETURN;
> + return;
>
> pnpi = netdev_priv(netdev);
>
> if (!pnpi->priv)
> - goto RETURN;
> + return;
This does not look right. If netdev is not NULL why does this function skip
free_netdev()?
Fabio could you follow up with Larry and/or Phillip and see why the code does
this? To me it looks like a potential bug.
Thanks!
Ira
>
> vfree(pnpi->priv);
> free_netdev(netdev);
> -
> -RETURN:
> - return;
> }
>
> int rtw_change_ifname(struct adapter *padapter, const char *ifname)
> --
> 2.34.1
>