Commit 6770b211 (ARM: OMAP2+: Export SoC information to userspace)
had some broken return value handling as noted by Russell King:
+ soc_dev = soc_device_register(soc_dev_attr);
+ if (IS_ERR_OR_NULL(soc_dev)) {
+ kfree(soc_dev_attr);
+ return;
+ }
+
+ parent = soc_device_to_device(soc_dev);
+ if (!IS_ERR_OR_NULL(parent))
+ device_create_file(parent, &omap_soc_attr);
This is nonsense. For the first, IS_ERR() is sufficient. For the second,
tell me what error checking is required in the return value of this
function:
struct device *soc_device_to_device(struct soc_device *soc_dev)
{
return &soc_dev->dev;
}
when you've already determined that the passed soc_dev is a valid pointer.
If you read the comments against the prototype:
/**
* soc_device_to_device - helper function to fetch struct device
* @soc: Previously registered SoC device container
*/
struct device *soc_device_to_device(struct soc_device *soc);
if "soc" is valid, it means the "previously registered SoC device container"
must have succeeded and that can only happen if the struct device has been
registered. Ergo, there will always be a valid struct device pointer for
any registered SoC device container. Therefore, if soc_device_register()
succeeds, then the return value from soc_device_to_device() will always be
valid and no error checking of it is required.
Simples. The rule as ever applies here: get to know the APIs your using
and don't fumble around in the dark hoping that you'll get this stuff
right.
Fix it as noted by Russell.
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>
b1dd11d60e