On Tue, Feb 04, 2020 at 12:32:15PM -0700, Nathan Chancellor wrote:
On Tue, Feb 04, 2020 at 10:00:39AM +0000, Mark Brown wrote:
I'm not convincd this is a sensible warning, at the use site a pointer to an array in a struct looks identical to an array embedded in the struct so it's not such a bad idea to check and refactoring of the struct could easily introduce problems.
Other static checkers like smatch will warn about this as well (since I am sure that is how Dan Carpenter found the same issue in the wcd9335 driver). Isn't an antipattern in the kernel to do things "just in case we do something later"? There are plenty of NULL checks removed from the kernel because they do not do anything now.
I'm not convinced it is an antipattern - adding the checks would be a bit silly but with the way C works the warnings feel like false positives. If the compiler were able to warn about missing NULL checks in the case where the thing in the struct is a pointer I'd be a lot happier with this.
I'd be fine with changing the check to something else that keeps the same logic but doesn't create a warning; I am not exactly sure what that would be because that is more of a specific driver logic thing, which I am not familiar with.
I've queued the change to be applied since it's shuts the compiler up but I'm really not convinced the compiler is helping here.