Re: [PATCH 7/11] drivers/net/wireless/ath9k: Move a dereferencebelow a NULL test

From: Julia Lawall
Date: Thu Dec 18 2008 - 12:11:37 EST


On Thu, 18 Dec 2008, John W. Linville wrote:

> On Tue, Dec 16, 2008 at 04:14:28PM +0100, Julia Lawall wrote:
> > From: Julia Lawall <julia@xxxxxxx>
> >
> > In each case, if the NULL test is necessary, then the dereference should be
> > moved below the NULL test.
> >
> > The semantic patch that makes this change is as follows:
> > (http://www.emn.fr/x-info/coccinelle/)
> >
> > // <smpl>
> > @@
> > type T;
> > expression E;
> > identifier i,fld;
> > statement S;
> > @@
> >
> > - T i = E->fld;
> > + T i;
> > ... when != E
> > when != i
> > if (E == NULL) S
> > + i = E->fld;
> > // </smpl>
> >
> > Signed-off-by: Julia Lawall <julia@xxxxxxx>
> >
> > ---
> > drivers/net/wireless/ath9k/hw.c | 3 ++-
> > 1 files changed, 2 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/net/wireless/ath9k/hw.c b/drivers/net/wireless/ath9k/hw.c
> > index 98bc25c..7d1dac6 100644
> > --- a/drivers/net/wireless/ath9k/hw.c
> > +++ b/drivers/net/wireless/ath9k/hw.c
> > @@ -5581,11 +5581,12 @@ static inline bool ath9k_hw_run_init_cals(struct ath_hal *ah,
> > struct ath9k_channel ichan;
> > bool isCalDone;
> > struct hal_cal_list *currCal = ahp->ah_cal_list_curr;
> > - const struct hal_percal_data *calData = currCal->calData;
> > + const struct hal_percal_data *calData;
> > int i;
> >
> > if (currCal == NULL)
> > return false;
> > + calData = currCal->calData;
> >
> > ichan.CalValid = 0;
>
> This patch doesn't seem to apply. I don't see this code anywhere.
> Perhaps this is against some older version?

I used the following version of linux-next, which indeed a bit out of
date:

commit feaf3848a813a106f163013af6fcf6c4bfec92d9
Merge: a771132... 0e435ac...
Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Wed Dec 3 16:45:56 2008 -0800


But I see the same code in the following version of linux-2.6

commit 1bda71282ded6a2e09a2db7c8884542fb46bfd4f
Merge: 7a62b17... 25a41b2...
Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Tue Dec 16 09:49:10 2008 -0800

julia
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