2022-08-05 06:30:35

by Bo Liu

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

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

Signed-off-by: Bo Liu <[email protected]>
---
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 = &dev_dax->dev;
dev->type = &dax_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 = &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

2022-08-05 18:36:37

by Ira Weiny

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

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 <[email protected]>
> ---
> 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 = &dev_dax->dev;
> dev->type = &dax_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 = &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
>
>

2022-09-20 18:08:54

by Dan Williams

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

Bo Liu wrote:
> It's possible that dev_set_name() returns -ENOMEM, catch and handle this.
>
> Signed-off-by: Bo Liu <[email protected]>
> ---
> 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 = &dev_dax->dev;
> dev->type = &dax_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.