Re: [PATCH] netlabel: remove redundant assignment to pointer iter

[Christophe JAILLET]

Le 01/09/2019 Ã 18:04, Paul Moore a ÃcritÂ:
> On Sun, Sep 1, 2019 at 11:52 AM Colin King <colin.king@xxxxxxxxxxxxx> wrote:
> > From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> >
> > Pointer iter is being initialized with a value that is never read and
> > is being re-assigned a little later on. The assignment is redundant
> > and hence can be removed.
> >
> > Addresses-Coverity: ("Unused value")
> > Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> > ---
> >   net/netlabel/netlabel_kapi.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> This patch doesn't seem correct to me, at least not in current form.
> At the top of _netlbl_catmap_getnode() is a check to see if iter is
> NULL (as well as a few other checks on iter after that); this patch
> would break that code.
>
> Perhaps we can get rid of the iter/catmap assignment when we define
> iter, but I don't think this patch is the right way to do it.
>
> > diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
> > index 2b0ef55cf89e..409a3ae47ce2 100644
> > --- a/net/netlabel/netlabel_kapi.c
> > +++ b/net/netlabel/netlabel_kapi.c
> > @@ -607,7 +607,7 @@ static struct netlbl_lsm_catmap *_netlbl_catmap_getnode(
> >    */
> >   int netlbl_catmap_walk(struct netlbl_lsm_catmap *catmap, u32 offset)
> >   {
> > -       struct netlbl_lsm_catmap *iter = catmap;
> > +       struct netlbl_lsm_catmap *iter;
> >          u32 idx;
> >          u32 bit;
> >          NETLBL_CATMAP_MAPTYPE bitmap;
> > --
> > 2.20.1

Hi,

'iter' is reassigned a value between the declaration and the NULL test, so removing the first initialization looks good to me.
int  netlbl_catmap_walk(struct  netlbl_lsm_catmap  *catmap,  u32  offset)
{
|

	struct  netlbl_lsm_catmap  *iter  =  catmap;
	u32  idx;
	u32  bit;
	NETLBL_CATMAP_MAPTYPE  bitmap;

	iter  =  _netlbl_catmap_getnode(&catmap,  offset,  _CM_F_WALK,  0);			<-- Here
	if  (iter  ==  NULL)
		return  -ENOENT; This is dead code since commit d960a6184a92 ("netlabel: fix the catmap walking functions") where the call to _netlbl_catmap_getnode has been introduced.

Just my 2c,

CJ|