Re: [PATCH] [RFC] Initialization of unused function parameters

[Linus Torvalds]

On Tue, Jun 14, 2022 at 11:08 AM Alexander Potapenko <glider@xxxxxxxxxx> wrote:
>
> On Tue, Jun 14, 2022 at 6:48 PM Linus Torvalds
> >
> > I'm assuming you mean pass by reference.
>
> No, sorry for being unclear. I mean passing by value.

Pass-by-value most definitely should warn about uninitialized variables.

> In the given example the prototype of step_into looks as follows (see
> https://elixir.bootlin.com/linux/latest/source/fs/namei.c#L1846):
>
>   static const char *step_into(struct nameidata *nd, int flags, struct
> dentry *dentry, struct inode *inode, unsigned seq);
>
> , and the local variables `struct inode *inode` and `unsigned seq` are
> being passed to it by value, i.e. in certain cases the struct inode
> pointer and the unsigned seq are uninitialized.

Then those cases should warn. No question about it.

I assume the only reason they don't warn right now is that the
compiler doesn't see that they are uninitialized, possibly due to some
earlier pass-by-reference use.

             Linus