RE: [PATCH] dax: Check dev_set_name() return value

[Dan Williams]

Bo Liu wrote:
> It's possible that dev_set_name() returns -ENOMEM, catch and handle this.
> 
> Signed-off-by: Bo Liu 
> ---
>  drivers/dax/bus.c | 11 +--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> index 1dad813ee4a6..36cf245ee467 100644
> --- a/drivers/dax/bus.c
> +++ b/drivers/dax/bus.c
> @@ -765,7 +765,12 @@ static int devm_register_dax_mapping(struct dev_dax 
> *dev_dax, int range_id)
>   device_initialize(dev);
>   dev->parent = _dax->dev;
>   dev->type = _mapping_type;
> - dev_set_name(dev, "mapping%d", mapping->id);
> + rc = dev_set_name(dev, "mapping%d", mapping->id);
> + if (rc) {
> + kfree(mapping);

No, this needs to trigger put_device() otherwise it leaks mapping->id.

Re: [PATCH] dax: Check dev_set_name() return value

[Ira Weiny]

On Fri, Aug 05, 2022 at 01:33:19AM -0400, Bo Liu wrote:
> It's possible that dev_set_name() returns -ENOMEM, catch and handle this.

Did this cause a bug or some other problem when the name was not set?

I think it is an ok change but without digging into the code I'm not clear why
you did this.

Ira

> 
> Signed-off-by: Bo Liu 
> ---
>  drivers/dax/bus.c | 11 +--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
> index 1dad813ee4a6..36cf245ee467 100644
> --- a/drivers/dax/bus.c
> +++ b/drivers/dax/bus.c
> @@ -765,7 +765,12 @@ static int devm_register_dax_mapping(struct dev_dax 
> *dev_dax, int range_id)
>   device_initialize(dev);
>   dev->parent = _dax->dev;
>   dev->type = _mapping_type;
> - dev_set_name(dev, "mapping%d", mapping->id);
> + rc = dev_set_name(dev, "mapping%d", mapping->id);
> + if (rc) {
> + kfree(mapping);
> + return rc;
> + }
> +
>   rc = device_add(dev);
>   if (rc) {
>   put_device(dev);
> @@ -1334,7 +1339,9 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data 
> *data)
>   dev_dax->region = dax_region;
>   dev = _dax->dev;
>   device_initialize(dev);
> - dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);
> + rc = dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);
> + if (rc)
> + goto err_range;
>  
>   rc = alloc_dev_dax_range(dev_dax, dax_region->res.start, data->size);
>   if (rc)
> -- 
> 2.27.0
> 
> 

[PATCH] dax: Check dev_set_name() return value

[Bo Liu]

It's possible that dev_set_name() returns -ENOMEM, catch and handle this.

Signed-off-by: Bo Liu 
---
 drivers/dax/bus.c | 11 +--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index 1dad813ee4a6..36cf245ee467 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -765,7 +765,12 @@ static int devm_register_dax_mapping(struct dev_dax 
*dev_dax, int range_id)
device_initialize(dev);
dev->parent = _dax->dev;
dev->type = _mapping_type;
-   dev_set_name(dev, "mapping%d", mapping->id);
+   rc = dev_set_name(dev, "mapping%d", mapping->id);
+   if (rc) {
+   kfree(mapping);
+   return rc;
+   }
+
rc = device_add(dev);
if (rc) {
put_device(dev);
@@ -1334,7 +1339,9 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data 
*data)
dev_dax->region = dax_region;
dev = _dax->dev;
device_initialize(dev);
-   dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);
+   rc = dev_set_name(dev, "dax%d.%d", dax_region->id, dev_dax->id);
+   if (rc)
+   goto err_range;
 
rc = alloc_dev_dax_range(dev_dax, dax_region->res.start, data->size);
if (rc)
-- 
2.27.0