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Date: Fri, 27 Jun 2025 01:17:57 +0200
Message-Id: <DAWUKB7PAZG1.2K2W9VCATZ3O0@kernel.org>
Subject: Re: [PATCH v4 4/5] rust: types: ForeignOwnable: Add type Target
From: "Benno Lossin" <lossin@kernel.org>
To: "Boqun Feng" <boqun.feng@gmail.com>, "Danilo Krummrich"
 <dakr@kernel.org>
Cc: <gregkh@linuxfoundation.org>, <rafael@kernel.org>, <ojeda@kernel.org>,
 <alex.gaynor@gmail.com>, <gary@garyguo.net>, <bjorn3_gh@protonmail.com>,
 <a.hindborg@kernel.org>, <aliceryhl@google.com>, <tmgross@umich.edu>,
 <david.m.ertman@intel.com>, <ira.weiny@intel.com>, <leon@kernel.org>,
 <kwilczynski@kernel.org>, <bhelgaas@google.com>,
 <rust-for-linux@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
 <linux-pci@vger.kernel.org>
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References: <20250626200054.243480-1-dakr@kernel.org>
 <20250626200054.243480-5-dakr@kernel.org> <aF2rpzSccqgoVvn0@tardis.local>
In-Reply-To: <aF2rpzSccqgoVvn0@tardis.local>

On Thu Jun 26, 2025 at 10:20 PM CEST, Boqun Feng wrote:
> On Thu, Jun 26, 2025 at 10:00:42PM +0200, Danilo Krummrich wrote:
>> diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
>> index 3958a5f44d56..74c787b352a9 100644
>> --- a/rust/kernel/types.rs
>> +++ b/rust/kernel/types.rs
>> @@ -27,6 +27,9 @@
>>  /// [`into_foreign`]: Self::into_foreign
>>  /// [`PointedTo`]: Self::PointedTo
>>  pub unsafe trait ForeignOwnable: Sized {
>> +    /// The payload type of the foreign-owned value.
>> +    type Target;
>
> I think `ForeignOwnable` also implies a `T` maybe get dropped via a
> pointer from `into_foreign()`. Not sure it's worth mentioning though.

What? How would that happen?

---
Cheers,
Benno