Re: [PATCH v5 4/5] rust_binder: consolidate transaction failure prints

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Oct 01, 2026 at 02:32:41PM +0200, Greg Kroah-Hartman wrote:
> On Tue, Sep 01, 2026 at 06:15:52PM +0200, Miguel Ojeda wrote:
> > On Mon, Aug 3, 2026 at 9:30 AM Alice Ryhl <aliceryhl@google.com> wrote:
> > >
> > > diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
> > > index a56ba6309594..380cd3f7276b 100644
> > > --- a/rust/kernel/error.rs
> > > +++ b/rust/kernel/error.rs
> > > @@ -135,7 +135,7 @@ pub fn from_errno(errno: crate::ffi::c_int) -> Error {
> > >      /// Creates an [`Error`] from a kernel error code.
> > >      ///
> > >      /// Returns [`None`] if `errno` is out-of-range.
> > > -    const fn try_from_errno(errno: crate::ffi::c_int) -> Option<Error> {
> > > +    pub const fn try_from_errno(errno: crate::ffi::c_int) -> Option<Error> {
> > >          if errno < -(bindings::MAX_ERRNO as i32) || errno >= 0 {
> > >              return None;
> > >          }
> > 
> > Generally speaking, one should know from the context whether an
> > integer is supposed to be an error or not, and thus it is rare to need
> > this function instead of the public one (this one is private, and the
> > two callers are here, not elsewhere in `kernel`).
> > 
> > So I wondered if Binder needs this -- I noticed the change when doing
> > my usual go-through-the-ML exercise and asked Alice about it, since it
> > seemed to me like Binder could perhaps avoid using the fallible
> > operation (and maybe even define an `enum` for `BinderError` instead
> > of a `struct` to be more precise about when a `source` is needed).
> > 
> > Alice told me that the `Option` in `BinderError` is just meant for the
> > zero case, i.e. the raw integer there should not be a random value.
> > Thus, since the `if` already covers the zero case, it does look like
> > this could use the infallible operation since we do know statically it
> > should be an error (modulo a bug).
> > 
> > So it sounds like the change can indeed be avoided, which should also
> > improve the code.
> > 
> > In any case, if we keep it, then the `error.rs` change should be
> > mentioned in the commit message.
> > 
> > By the way, I am still happy to take the first three patches unless
> > Binder is picking this up.
> 
> I'll just take them all now, thanks.
 
Nope, the first patch doesn't apply against my tree, so I can't take
this :(