Re: [PATCH 4.14 58/62] mtd: rawnand: atmel: fix OF child-node lookup

[Naresh Kamboju]

Do you see build failure arm x15 beagleboard on 4.14 due to this patch ?

On Mon, 26 Nov 2018 at 16:31, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>
> 4.14-stable review patch.  If anyone has any objections, please let me know.
>
> ------------------
>
> From: Johan Hovold <johan@xxxxxxxxxx>
>
> commit 5d1e9c2212ea6b4dd735e4fc3dd6279a365d5d10 upstream.
>
> Use the new of_get_compatible_child() helper to lookup the nfc child
> node instead of using of_find_compatible_node(), which searches the
> entire tree from a given start node and thus can return an unrelated
> (i.e. non-child) node.
>
> This also addresses a potential use-after-free (e.g. after probe
> deferral) as the tree-wide helper drops a reference to its first
> argument (i.e. the node of the device being probed).
>
> While at it, also fix a related nfc-node reference leak.
>
> Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver")
> Cc: stable <stable@xxxxxxxxxxxxxxx>     # 4.11
> Cc: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
> Cc: Josh Wu <rainyfeeling@xxxxxxxxxxx>
> Cc: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>
> ---
>  drivers/mtd/nand/atmel/nand-controller.c |   11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
>
> --- a/drivers/mtd/nand/atmel/nand-controller.c
> +++ b/drivers/mtd/nand/atmel/nand-controller.c
> @@ -2077,8 +2077,7 @@ atmel_hsmc_nand_controller_legacy_init(s
>         int ret;
>
>         nand_np = dev->of_node;
> -       nfc_np = of_find_compatible_node(dev->of_node, NULL,
> -                                        "atmel,sama5d3-nfc");
> +       nfc_np = of_get_compatible_child(dev->of_node, "atmel,sama5d3-nfc");
>         if (!nfc_np) {
>                 dev_err(dev, "Could not find device node for sama5d3-nfc\n");
>                 return -ENODEV;
> @@ -2492,15 +2491,19 @@ static int atmel_nand_controller_probe(s
>         }
>
>         if (caps->legacy_of_bindings) {
> +               struct device_node *nfc_node;
>                 u32 ale_offs = 21;
>
>                 /*
>                  * If we are parsing legacy DT props and the DT contains a
>                  * valid NFC node, forward the request to the sama5 logic.
>                  */
> -               if (of_find_compatible_node(pdev->dev.of_node, NULL,
> -                                           "atmel,sama5d3-nfc"))
> +               nfc_node = of_get_compatible_child(pdev->dev.of_node,
> +                                                  "atmel,sama5d3-nfc");
> +               if (nfc_node) {
>                         caps = &atmel_sama5_nand_caps;
> +                       of_node_put(nfc_node);
> +               }
>
>                 /*
>                  * Even if the compatible says we are dealing with an
>
>

/drivers/mtd/nand/atmel/nand-controller.c: In function
'atmel_hsmc_nand_controller_legacy_init':
/drivers/mtd/nand/atmel/nand-controller.c:2080:11: error: implicit
declaration of function 'of_get_compatible_child'; did you mean
'of_get_next_available_child'? [-Werror=implicit-function-declaration]
   nfc_np = of_get_compatible_child(dev->of_node, "atmel,sama5d3-nfc");
            ^~~~~~~~~~~~~~~~~~~~~~~
            of_get_next_available_child
 /drivers/mtd/nand/atmel/nand-controller.c:2080:9: warning: assignment
makes pointer from integer without a cast [-Wint-conversion]
   nfc_np = of_get_compatible_child(dev->of_node, "atmel,sama5d3-nfc");
          ^
 /drivers/mtd/nand/atmel/nand-controller.c: In function
'atmel_nand_controller_probe':
 /drivers/mtd/nand/atmel/nand-controller.c:2501:12: warning:
assignment makes pointer from integer without a cast
[-Wint-conversion]
    nfc_node = of_get_compatible_child(pdev->dev.of_node,
             ^

Full build log link,
https://ci.linaro.org/job/openembedded-lkft-linux-stable-rc-4.14/DISTRO=rpb,MACHINE=am57xx-evm,label=docker-lkft/336/consoleFull

Best regards
Naresh Kamboju