On Thu, May 28, 2026 at 06:23:50AM +0000, Alice Ryhl wrote:
> On Wed, May 27, 2026 at 04:03:30PM -0700, Paul E. McKenney wrote:
> > On Wed, May 27, 2026 at 08:40:42PM +0300, Onur Özkan wrote:
> > > Add helper wrappers for SRCU functions that are exposed to Rust
> > > through generated bindings.
> > >
> > > Signed-off-by: Onur Özkan <[email protected]>
> > > ---
> > > rust/helpers/helpers.c | 1 +
> > > rust/helpers/srcu.c | 34 ++++++++++++++++++++++++++++++++++
> > > 2 files changed, 35 insertions(+)
> > > create mode 100644 rust/helpers/srcu.c
> > >
> > > diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
> > > index 625921e27dfb..f3562d3b3888 100644
> > > --- a/rust/helpers/helpers.c
> > > +++ b/rust/helpers/helpers.c
> > > @@ -88,6 +88,7 @@
> > > #include "signal.c"
> > > #include "slab.c"
> > > #include "spinlock.c"
> > > +#include "srcu.c"
> > > #include "sync.c"
> > > #include "task.c"
> > > #include "time.c"
> > > diff --git a/rust/helpers/srcu.c b/rust/helpers/srcu.c
> > > new file mode 100644
> > > index 000000000000..79dd24a104ef
> > > --- /dev/null
> > > +++ b/rust/helpers/srcu.c
> > > @@ -0,0 +1,34 @@
> > > +// SPDX-License-Identifier: GPL-2.0
> > > +
> > > +#include <linux/srcu.h>
> > > +
> > > +__rust_helper int rust_helper_init_srcu_struct_with_key(struct
> > > srcu_struct *ssp,
> > > + const char *name,
> > > + struct lock_class_key
> > > *key)
> > > +{
> > > +#ifdef CONFIG_DEBUG_LOCK_ALLOC
> > > + return __init_srcu_struct(ssp, name, key);
> > > +#else /* !CONFIG_DEBUG_LOCK_ALLOC */
> > > + return init_srcu_struct(ssp);
> > > +#endif /* CONFIG_DEBUG_LOCK_ALLOC */
> > > +}
> >
> > Similar to Boqun's feedback on a later patch, could you please make
> > these be two functions under the corresponding legs of the existing
> > CONFIG_DEBUG_LOCK_ALLOC #ifdef in include/linux/srcu.h? You are including
> > that file above, so it should work well.
> >
> > Actually, you could just name thefunction __init_srcu_struct(), use the
> > existing definition under #ifdef CONFIG_DEBUG_LOCK_ALLOC, and just create
> > the simple wrapper in the other leg of this #ifdef. That would be more
> > aligned with the Linux-kernel coding guidelines and also be less code.
> >
> > Or is the "rust_helper_" prefix mandatory? If so, you could make
> > rust_helper_init_srcu_struct() be a wrapper for __init_srcu_struct()
> > in this file, then just define __init_srcu_struct() as a wrapper around
> > init_srcu_struct() in the !CONFIG_DEBUG_LOCK_ALLOC leg of the #ifdef
> > in include/linux/srcu.h.
>
> The rust_helper_ prefix helps avoid duplicate symbol errors.
>
> When you invoke `bindings::foo` then it will prefer to call the symbol
> actually called `foo()`, but if there is no `foo` symbol, then it will
> fall back to `rust_helper_foo()`.
>
> This is useful because many symbols are only marked inline under some
> configurations, and this makes it automatically pick the right one
> depending on whether the real symbol exists or not.
Thank you both for the Rust-bindings tutorial! ;-)
Thanx, Paul
