Messages in this thread | | | Date | Thu, 16 Jun 2022 11:31:32 +0100 | Subject | Re: [PATCH v2 2/5] iommu/mediatek: Add error path for loop of mm_dts_parse | From | Robin Murphy <> |
| |
On 2022-06-16 11:08, Yong Wu wrote: > On Thu, 2022-06-16 at 09:59 +0100, Robin Murphy wrote: >> On 2022-06-16 06:42, Yong Wu wrote: >>> The mtk_iommu_mm_dts_parse will parse the smi larbs nodes. if the >>> i+1 >>> larb is parsed fail(return -EINVAL), we should of_node_put for the >>> 0..i >>> larbs. In the fail path, one of_node_put matches with >>> of_parse_phandle in >>> it. >>> >>> Fixes: d2e9a1102cfc ("iommu/mediatek: Contain MM IOMMU flow with >>> the MM TYPE") >>> Signed-off-by: Yong Wu <yong.wu@mediatek.com> >>> --- >>> drivers/iommu/mtk_iommu.c | 21 ++++++++++++++++----- >>> 1 file changed, 16 insertions(+), 5 deletions(-) >>> >>> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c >>> index 3b2489e8a6dd..ab24078938bf 100644 >>> --- a/drivers/iommu/mtk_iommu.c >>> +++ b/drivers/iommu/mtk_iommu.c >>> @@ -1071,12 +1071,12 @@ static int mtk_iommu_mm_dts_parse(struct >>> device *dev, struct component_match **m >>> >>> plarbdev = of_find_device_by_node(larbnode); >>> if (!plarbdev) { >>> - of_node_put(larbnode); >>> - return -ENODEV; >>> + ret = -ENODEV; >>> + goto err_larbnode_put; >>> } >>> if (!plarbdev->dev.driver) { >>> - of_node_put(larbnode); >>> - return -EPROBE_DEFER; >>> + ret = -EPROBE_DEFER; >>> + goto err_larbnode_put; >>> } >>> data->larb_imu[id].dev = &plarbdev->dev; >>> >>> @@ -1107,9 +1107,20 @@ static int mtk_iommu_mm_dts_parse(struct >>> device *dev, struct component_match **m >>> DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME); >>> if (!link) { >>> dev_err(dev, "Unable to link %s.\n", dev_name(data- >>>> smicomm_dev)); >>> - return -EINVAL; >>> + ret = -EINVAL; >>> + goto err_larbnode_put; >>> } >>> return 0; >>> + >>> +err_larbnode_put: >>> + while (i--) { >>> + larbnode = of_parse_phandle(dev->of_node, >>> "mediatek,larbs", i); >>> + if (larbnode && of_device_is_available(larbnode)) { >>> + of_node_put(larbnode); >>> + of_node_put(larbnode); >>> + } >> >> This looks a bit awkward - could we not just iterate through >> data->larb_imu and put dev->of_node for each valid dev? > > It should work. Thanks very much. > >> >> Also, of_find_device_by_node() takes a reference on the struct >> device >> itself, so strictly we should be doing put_device() on those as well >> if we're bailing out. > > Thanks for this hint. A new reference for me. I will add it.
In fact, thinking about it some more we may as well do the of_node_put() unconditionally immediately after the of_find_device_by_node() call, so then it's *only* the device references we'd need to worry about cleaning up in the failure path.
Robin.
| |