Re: [PATCH v2] rust: place generated init_module() function in .init.text

[Alice Ryhl <aliceryhl@google.com>]

On Tue, Feb 6, 2024 at 11:01 AM Greg KH <greg@kroah.com> wrote:
>
> On Mon, Feb 05, 2024 at 06:25:35PM -0700, Thomas Bertschinger wrote:
> >              // Loadable modules need to export the `{{init,cleanup}}_module` identifiers.
> > +            /// # Safety
> > +            /// This function must only be called once, during module initialization, because it
> > +            /// may be freed after it returns.
>
> Oh, and the compiler will catch this if you get it wrong, correct?
>
> If not, you all should work on that, as it is caught in C code :)

Based on the commit message, it sounds like the warning that C uses to
catch this happens a link-time, which means that it is also triggered
on Rust code:

> If a Rust `init_module()` function (that lives in `.text`) calls a C
> function annotated with `__init`, then a warning is generated because
> the C function lives in `.init.text`.

I suggested that we make this function unsafe too, to make it even
harder to call incorrectly. But I think for the more general case of
this problem, it makes sense to rely on the existing warning for this.

Alice