| Message ID | 20240930-net-device_for_each_child_node_scoped-v1-1-bbdd7f9fd649@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: switch to scoped device_for_each_child_node() | expand |
On Mon, Sep 30, 2024 at 10:03:29PM +0200, Javier Carrasco wrote: > There has already been an issue with the handling of early exits from > device_for_each_child() in this driver, and it was solved with commit > b1de5c78ebe9 ("net: mdio: thunder: Add missing fwnode_handle_put()") by > adding a call to fwnode_handle_put() right after the loop. > > That solution is valid indeed, but if a new error path with a 'return' > is added to the loop, this solution will fail. A more secure approach > is using the scoped variant of the macro, which automatically > decrements the refcount of the child node when it goes out of scope, > removing the need for explicit calls to fwnode_handle_put(). Hi Javier I know you are going across the whole tree, multiple sub systems, and each has its own rules. I think naming patches is however pretty uniform across the tree. Do what other patches did: d84fe6dc7377 net: mdio: thunder: Add missing fwnode_handle_put() a93a0a15876d net: mdio: thunder: Fix a double free issue in the .remove function netdev has some additional documentation you should read: https://www.kernel.org/doc/html/latest/process/maintainer-netdev.html The change itself looks O.K, its just the processes which need work. Andrew
On 30/09/2024 22:10, Andrew Lunn wrote: > On Mon, Sep 30, 2024 at 10:03:29PM +0200, Javier Carrasco wrote: >> There has already been an issue with the handling of early exits from >> device_for_each_child() in this driver, and it was solved with commit >> b1de5c78ebe9 ("net: mdio: thunder: Add missing fwnode_handle_put()") by >> adding a call to fwnode_handle_put() right after the loop. >> >> That solution is valid indeed, but if a new error path with a 'return' >> is added to the loop, this solution will fail. A more secure approach >> is using the scoped variant of the macro, which automatically >> decrements the refcount of the child node when it goes out of scope, >> removing the need for explicit calls to fwnode_handle_put(). > > Hi Javier > > I know you are going across the whole tree, multiple sub systems, and > each has its own rules. I think naming patches is however pretty > uniform across the tree. Do what other patches did: > > d84fe6dc7377 net: mdio: thunder: Add missing fwnode_handle_put() > a93a0a15876d net: mdio: thunder: Fix a double free issue in the .remove function > > netdev has some additional documentation you should read: > > https://www.kernel.org/doc/html/latest/process/maintainer-netdev.html > > The change itself looks O.K, its just the processes which need work. > > Andrew Hi Andrew, thanks for your feedback. I used the same name I found in the first two patches for that file, and I missed the 'thunder:' because probably those patches applied to more files. And the same applies for hns_dsaf_mac.c. I will fix that for v2 alongside anything I might find in the netdev documentation that might be missing too. Best regards, Javier Carrasco
diff --git a/drivers/net/mdio/mdio-thunder.c b/drivers/net/mdio/mdio-thunder.c index 6067d96b2b7b..1e1aa72b1eff 100644 --- a/drivers/net/mdio/mdio-thunder.c +++ b/drivers/net/mdio/mdio-thunder.c @@ -23,7 +23,6 @@ static int thunder_mdiobus_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent) { struct device_node *node; - struct fwnode_handle *fwn; struct thunder_mdiobus_nexus *nexus; int err; int i; @@ -54,7 +53,7 @@ static int thunder_mdiobus_pci_probe(struct pci_dev *pdev, } i = 0; - device_for_each_child_node(&pdev->dev, fwn) { + device_for_each_child_node_scoped(&pdev->dev, fwn) { struct resource r; struct mii_bus *mii_bus; struct cavium_mdiobus *bus; @@ -106,7 +105,6 @@ static int thunder_mdiobus_pci_probe(struct pci_dev *pdev, if (i >= ARRAY_SIZE(nexus->buses)) break; } - fwnode_handle_put(fwn); return 0; err_release_regions:
There has already been an issue with the handling of early exits from device_for_each_child() in this driver, and it was solved with commit b1de5c78ebe9 ("net: mdio: thunder: Add missing fwnode_handle_put()") by adding a call to fwnode_handle_put() right after the loop. That solution is valid indeed, but if a new error path with a 'return' is added to the loop, this solution will fail. A more secure approach is using the scoped variant of the macro, which automatically decrements the refcount of the child node when it goes out of scope, removing the need for explicit calls to fwnode_handle_put(). Signed-off-by: Javier Carrasco <javier.carrasco.cruz@gmail.com> --- drivers/net/mdio/mdio-thunder.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)