I'd add something like assert (head && entry) up there.

eatbitseveryday · on Oct 26, 2016

A NULL head is not an error (= empty list) and 'assert' would be better as a BUG_ON or panic if it is technically an error.

avip · on Oct 26, 2016

It is an error though if your code SEGFAULT on NULL head (and this one does).

I wouldn't care, but if you claim to be defensive, go full monty.

eatbitseveryday · on Oct 26, 2016

> It is an error though if your code SEGFAULT on NULL head (and this one does).

There is no "SEGFAULT" in kernel code. SIGSEGV is a signal, which is only used at user-level.

NULL dereference in the kernel results in an "oops".

I believe it is also assumed in their code that "entry" is not going to be NULL, meaning "if (head == entry)" will never succeed if head is NULL.

avip · on Oct 26, 2016

The code crashes if head is NULL, regardless of entry.