On Sun, 20 Sep 2020, Greg Kroah-Hartman wrote: > On Sun, Sep 20, 2020 at 01:26:13PM +0200, Julia Lawall wrote: > > sg_init_table zeroes its first argument, so the allocation of that argument > > doesn't have to. > > > > the semantic patch that makes this change is as follows: > > (http://coccinelle.lip6.fr/) > > > > // <smpl> > > @@ > > expression x,n,flags; > > @@ > > > > x = > > - kcalloc > > + kmalloc_array > > (n,sizeof(struct scatterlist),flags) > > ... > > sg_init_table(x,n) > > // </smpl> > > > > Signed-off-by: Julia Lawall <Julia.Lawall@xxxxxxxx> > > It inits the first entry in the array, but what about all of the other > ones? Is that "safe" to have uninitialized data in them like your > change causes to happen? Sorry, I don't follow. The complete code is: priv->sg_tx_p = kcalloc(num, sizeof(struct scatterlist), GFP_ATOMIC); if (!priv->sg_tx_p) { dev_err(priv->port.dev, "%s:kzalloc Failed\n", __func__); return 0; } sg_init_table(priv->sg_tx_p, num); /* Initialize SG table */ and the definition of sg_init_table is: void sg_init_table(struct scatterlist *sgl, unsigned int nents) { memset(sgl, 0, sizeof(*sgl) * nents); sg_init_marker(sgl, nents); } It looks to me like it zeroes all of the elements? The same file does contain a call: sg_init_table(&priv->sg_rx, 1); But that's not the one associated with the patch. julia
