"Alice Ryhl" <aliceryhl@xxxxxxxxxx> writes: > On Wed, Jun 11, 2025 at 12:46 PM Andreas Hindborg <a.hindborg@xxxxxxxxxx> wrote: >> >> "Alice Ryhl" <aliceryhl@xxxxxxxxxx> writes: >> >> > On Thu, Jun 5, 2025 at 10:00 PM Andreas Hindborg <a.hindborg@xxxxxxxxxx> wrote: >> >> >> >> The current implementation of `ForeignOwnable` is leaking the type of the >> >> opaque pointer to consumers of the API. This allows consumers of the opaque >> >> pointer to rely on the information that can be extracted from the pointer >> >> type. >> >> >> >> To prevent this, change the API to the version suggested by Maira >> >> Canal (link below): Remove `ForeignOwnable::PointedTo` in favor of a >> >> constant, which specifies the alignment of the pointers returned by >> >> `into_foreign`. >> >> >> >> Suggested-by: Alice Ryhl <aliceryhl@xxxxxxxxxx> >> >> Suggested-by: Maíra Canal <mcanal@xxxxxxxxxx> >> >> Link: https://lore.kernel.org/r/20240309235927.168915-3-mcanal@igaliacom >> >> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx> >> > >> > One nit below. With that and things other folks mentioned fixed, you may add: >> > >> > Reviewed-by: Alice Ryhl <aliceryhl@xxxxxxxxxx> >> > >> >> diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs >> >> index 22985b6f6982..025c619a2195 100644 >> >> --- a/rust/kernel/types.rs >> >> +++ b/rust/kernel/types.rs >> >> @@ -21,15 +21,11 @@ >> >> /// >> >> /// # Safety >> >> /// >> >> -/// Implementers must ensure that [`into_foreign`] returns a pointer which meets the alignment >> >> -/// requirements of [`PointedTo`]. >> >> -/// >> >> -/// [`into_foreign`]: Self::into_foreign >> >> -/// [`PointedTo`]: Self::PointedTo >> >> +/// Implementers must ensure that [`Self::into_foreign`] return pointers with alignment that is an >> >> +/// integer multiple of [`Self::FOREIGN_ALIGN`]. >> > >> > We should require non-null: >> >> What is your rationale for this? > > The rationale is that the implementation of XArray assumes that the > pointers are non-null. If we allow null pointers, we will need to fix > the XArray. OK, thanks. Also, `try_from_foreign` as Benno highlighted. Best regards, Andreas Hindborg
