[PATCH] rust: drm: gem: clean up GEM state in init failure case

[PATCH] rust: drm: gem: clean up GEM state in init failure case

[Eliot Courtney]

Currently, if `drm_gem_object_init` fails, the object is freed without
any cleanup. Perform the cleanup in that case.

Signed-off-by: Eliot Courtney <ecourtney@nvidia.com>
---
I looked at `drm_gem_shmem_init` for an example, and it seems like the
correct cleanup here is to do `drm_gem_private_object_fini` if
`drm_gem_object_init` fails. Other C drivers do different things, but
looking at the implementation of `drm_gem_object_init`, this looks like
the only thing we need to clean up.
---
 rust/kernel/drm/gem/mod.rs | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
index 75acda7ba500..7b6a085ace27 100644
--- a/rust/kernel/drm/gem/mod.rs
+++ b/rust/kernel/drm/gem/mod.rs
@@ -278,7 +278,14 @@ pub fn new(dev: &drm::Device<T::Driver>, size: usize, args: T::Args) -> Result<A
         unsafe { (*obj.as_raw()).funcs = &Self::OBJECT_FUNCS };
 
         // SAFETY: The arguments are all valid per the type invariants.
-        to_result(unsafe { bindings::drm_gem_object_init(dev.as_raw(), obj.obj.get(), size) })?;
+        if let Err(err) =
+            to_result(unsafe { bindings::drm_gem_object_init(dev.as_raw(), obj.obj.get(), size) })
+        {
+            // SAFETY: `drm_gem_object_init()` initializes the private GEM object state before
+            // failing, so `drm_gem_private_object_fini()` is the matching cleanup.
+            unsafe { bindings::drm_gem_private_object_fini(obj.obj.get()) };
+            return Err(err);
+        }
 
         // SAFETY: We will never move out of `Self` as `ARef<Self>` is always treated as pinned.
         let ptr = KBox::into_raw(unsafe { Pin::into_inner_unchecked(obj) });

---
base-commit: a7a080bb4236ebe577b6776d940d1717912ff6dd
change-id: 20260423-fix-gem-1-6c68b9fa0972

Best regards,
--  
Eliot Courtney <ecourtney@nvidia.com>