Commit 0dab138d authored by Danilo Krummrich's avatar Danilo Krummrich
Browse files

rust: devres: require T: Send for Devres 



Due to calling Revocable::revoke() from Devres::devres_callback() T may
be dropped from Devres::devres_callback() and hence must be Send.

Fix this by adding the corresponding bound to Devres and DevresInner.

Reported-by: default avatarBoqun Feng <boqun.feng@gmail.com>
Closes: https://lore.kernel.org/lkml/aFzI5L__OcB9hqdG@Mac.home/


Fixes: 76c01ded ("rust: add devres abstraction")
Reviewed-by: default avatarBoqun Feng <boqun.fenng@gmail.com>
Reviewed-by: default avatarBenno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/20250626132544.72866-1-dakr@kernel.org


Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
parent 140a9d04

rust/kernel/devres.rs

+5 −5
Original line number Diff line number Diff line
@@ -18,7 +18,7 @@ 
};



#[pin_data]

struct DevresInner<T> {

struct DevresInner<T: Send> {

    dev: ARef<Device>,

    callback: unsafe extern "C" fn(*mut c_void),

    #[pin]
@@ -95,9 +95,9 @@ struct DevresInner<T> { 
/// # Ok(())

/// # }

/// ```

pub struct Devres<T>(Arc<DevresInner<T>>);

pub struct Devres<T: Send>(Arc<DevresInner<T>>);



impl<T> DevresInner<T> {

impl<T: Send> DevresInner<T> {

    fn new(dev: &Device<Bound>, data: T, flags: Flags) -> Result<Arc<DevresInner<T>>> {

        let inner = Arc::pin_init(

            pin_init!( DevresInner {
@@ -175,7 +175,7 @@ fn remove_action(this: &Arc<Self>) -> bool { 
    }

}



impl<T> Devres<T> {

impl<T: Send> Devres<T> {

    /// Creates a new [`Devres`] instance of the given `data`. The `data` encapsulated within the

    /// returned `Devres` instance' `data` will be revoked once the device is detached.

    pub fn new(dev: &Device<Bound>, data: T, flags: Flags) -> Result<Self> {
@@ -247,7 +247,7 @@ pub fn try_access_with_guard<'a>(&'a self, guard: &'a rcu::Guard) -> Option<&'a 
    }

}



impl<T> Drop for Devres<T> {

impl<T: Send> Drop for Devres<T> {

    fn drop(&mut self) {

        // SAFETY: When `drop` runs, it is guaranteed that nobody is accessing the revocable data

        // anymore, hence it is safe not to wait for the grace period to finish.