Subject: Re: linux-next: build failure after merge of the rust tree

From: Greg Kroah-Hartman <[email-masked]>
Date: Fri, 10 Jan 2025 10:34:50 +0100

On Fri, Jan 10, 2025 at 10:28:46AM +0100, Alice Ryhl wrote:
> On Fri, Jan 10, 2025 at 6:28 AM Stephen Rothwell <[email-masked]> wrote:
> >
> > Hi all,
> >
> > After merging the rust tree, today's linux-next build (x86_64
> > allmodconfig) failed like this:
> >
> > error[E0423]: expected function, found macro `kernel::build_error`
> >    --> rust/kernel/miscdevice.rs:159:9
> >     |
> > 159 |         kernel::build_error(VTABLE_DEFAULT_ERROR)
> >     |         ^^^^^^^^^^^^^^^^^^^ not a function
> >     |
> > help: use `!` to invoke the macro
> >     |
> > 159 |         kernel::build_error!(VTABLE_DEFAULT_ERROR)
> >     |                            +
> > help: consider importing one of these functions instead
> >     |
> > 11  + use crate::build_assert::build_error;
> >     |
> > 11  + use build_error::build_error;
> >     |
> > help: if you import `build_error`, refer to it directly
> >     |
> > 159 -         kernel::build_error(VTABLE_DEFAULT_ERROR)
> > 159 +         build_error(VTABLE_DEFAULT_ERROR)
> >     |
> >
> > error: aborting due to 1 previous error
> >
> > For more information about this error, try `rustc --explain E0423`.
> >
> > Caused by commit
> >
> >   614724e780f5 ("rust: kernel: move `build_error` hidden function to prevent mistakes")
> >
> > interacting with commit
> >
> >   5bcc8bfe841b ("rust: miscdevice: add fops->show_fdinfo() hook")
> >
> > from the driver-core tree.
> >
> > I have added the following merge resolution patch.
> >
> > From: Stephen Rothwell <[email-masked]>
> > Date: Fri, 10 Jan 2025 16:02:19 +1100
> > Subject: [PATCH] fix up for "rust: kernel: move `build_error` hidden function
> >  to prevent mistakes"
> >
> > interacting with commit
> >
> >   5bcc8bfe841b ("rust: miscdevice: add fops->show_fdinfo() hook")
> >
> > from the driver-core tree.
> >
> > Signed-off-by: Stephen Rothwell <[email-masked]>
> > ---
> >  rust/kernel/miscdevice.rs | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/rust/kernel/miscdevice.rs b/rust/kernel/miscdevice.rs
> > index 9685e50b100d..3ba018651bc0 100644
> > --- a/rust/kernel/miscdevice.rs
> > +++ b/rust/kernel/miscdevice.rs
> > @@ -156,7 +156,7 @@ fn show_fdinfo(
> >          _m: &SeqFile,
> >          _file: &File,
> >      ) {
> > -        kernel::build_error(VTABLE_DEFAULT_ERROR)
> > +        build_error!(VTABLE_DEFAULT_ERROR)
> >      }
> >  }
> 
> Thank you, this fix is correct. Greg, can you pick this up directly,
> or do you want a real patch?

Can I take this as a real patch for my tree?  Or is this only an issue
due to the trees being merged?

thanks,

greg k-h