Hello, On Thu, Nov 12, 2015 at 11:03:28AM +0100, LABBE Corentin wrote: > On Thu, Nov 12, 2015 at 09:19:09AM +0100, Uwe Kleine-König wrote: > > Hello Corentin, > > > > On Thu, Nov 12, 2015 at 08:46:55AM +0100, LABBE Corentin wrote: > > > of_match_device could return NULL, and so cause a NULL pointer > > > dereference later. > > > > > > Signed-off-by: LABBE Corentin <clabbe.montj...@gmail.com> > > > --- > > > drivers/mtd/nand/mxc_nand.c | 6 ++++-- > > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > > > diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c > > > index 136e73a..9e42431 100644 > > > --- a/drivers/mtd/nand/mxc_nand.c > > > +++ b/drivers/mtd/nand/mxc_nand.c > > > @@ -1464,8 +1464,7 @@ static int __init mxcnd_probe_dt(struct > > > mxc_nand_host *host) > > > { > > > struct device_node *np = host->dev->of_node; > > > struct mxc_nand_platform_data *pdata = &host->pdata; > > > - const struct of_device_id *of_id = > > > - of_match_device(mxcnd_dt_ids, host->dev); > > > + const struct of_device_id *of_id; > > > int buswidth; > > > > > > if (!np) > > > @@ -1482,6 +1481,9 @@ static int __init mxcnd_probe_dt(struct > > > mxc_nand_host *host) > > > > > > pdata->width = buswidth / 8; > > > > > > + of_id = of_match_device(mxcnd_dt_ids, host->dev); > > > + if (!of_id) > > > + return -ENODEV; > > > > You should return 1 here instead of -ENODEV. Also this check should > > better be done instead of > > > > if (!np) > > return 1; > > > > at the start of the function. > > Are you sure for the "1" value ? It seems a very bad error value. > And I found plenty of case where if (!np) return -Esomething and no example > of return 1
This is not an error value. The semantic is: 0 everything ok, initialized from dt 1 device was not probed by dt -> fall back to board-file stuff <0 error that should abort probing Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/