On Thu, 1 Jul 2021 10:31:59 -0700 Paul Burton paulburton@google.com wrote:
I was tempted to just add the redundant checks anyway (pick your battles and all) but for show() in particular it wound up making things seem non-sensical to me ("display the value describing this non-NULL pointer into tgid_map only if tgid_map is not NULL?").
I agree with your assessment, and will actually take your first patch, as I don't think the comment is that helpful, not to mention, we don't use '//' comments in the kernel, so that would have to be changed.
But for cases like this, I usually have something like:
if (WARN_ON_ONCE(!tgid_map)) return -1;
Because the logic is what makes tgid_map not being NULL, but as experience has taught me, the logic can sometimes be mistaken, at least as time goes by. And things that are protected by logic, deserve a WARN*() when it doesn't go as planned.
We can always add that later, if needed.
-- Steve