Commit 91ae26b0 authored by Danilo Krummrich's avatar Danilo Krummrich
Browse files

rust: devres: initialize Devres::inner::data last 

Users may want to access the Devres object from callbacks registered
through the initialization of Devres::inner::data.

For those accesses to be valid, Devres::inner::data must be initialized
last [1].

Credit to Boqun for spotting this [2].

Link: https://lore.kernel.org/lkml/DBBPHO26CPBS.2OVI1OERCB2J5@kernel.org/ [1]
Link: https://lore.kernel.org/lkml/aHSmxWeIy3L-AKIV@Mac.home/

 [2]
Reviewed-by: default avatarAlice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250714113712.22158-1-dakr@kernel.org


Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
parent 3964d07d

rust/kernel/devres.rs

+8 −8
Original line number Diff line number Diff line
@@ -137,14 +137,10 @@ pub fn new<'a, E>( 
        let callback = Self::devres_callback;



        try_pin_init!(&this in Self {

            // INVARIANT: `inner` is properly initialized.

            inner <- Opaque::pin_init(try_pin_init!(Inner {

                data <- Revocable::new(data),

                devm <- Completion::new(),

                revoke <- Completion::new(),

            })),

            dev: dev.into(),

            callback,

            dev: {

            // INVARIANT: `inner` is properly initialized.

            inner <- {

                // SAFETY: `this` is a valid pointer to uninitialized memory.

                let inner = unsafe { &raw mut (*this.as_ptr()).inner };
@@ -158,7 +154,11 @@ pub fn new<'a, E>( 
                    bindings::devm_add_action(dev.as_raw(), Some(callback), inner.cast())

                })?;



                dev.into()

                Opaque::pin_init(try_pin_init!(Inner {

                    devm <- Completion::new(),

                    revoke <- Completion::new(),

                    data <- Revocable::new(data),

                }))

            },

        })

    }