Atomics in Rust Binder

[Darksonn]

The Rust Binder driver still uses core::sync::atomic, but since 4333928 this is deprecated. It needs to be switched over to using the new kernel-specific atomic type.

Rust Binder has uses of AtomicBool, which should be replaced with a new AtomicFlag that wraps an Atomic<u32>.

[AryanBagade]

Hey @Darksonn
Myself Aryan,
Learning Rust, contributor to multiple rust repos including facebook/pyrefly, nvidia/dynamo.
if this issue if open for external contributors, could you please assign me this issue
Thanks

[ojeda]

Yes, these good first issues are, so please feel free to go ahead and send the patch whenever you have it. We normally don't assign issues, but I have done it in case it helps you. Thanks!

[AryanBagade]

Thanks!!

[AryanBagade]

Hi @ojeda,
I've implemented the fix for this issue:

• Added AtomicFlag wrapper in rust/kernel/sync/atomic.rs that wraps Atomic
• Replaced all core::sync::atomic::AtomicBool usage in Rust Binder with AtomicFlag
• Updated drivers/android/binder/transaction.rs and drivers/android/binder/rust_binder_main.rs
• Code passes rustfmt and checkpatch.pl with 0 errors/warnings

Testing limitation: I'm working on macOS with a case-insensitive filesystem, which prevents me from doing a full local kernel build due to the repository having files with conflicting case-sensitive names (e.g., xt_CONNMARK.h vs xt_connmark.h). The code changes are ready, but I haven't been able to test with CLIPPY=1 locally.

Before submitting, I wanted to confirm: Should I create a GitHub Pull Request, or send patches via email/mailing list?
Im new to contributing to kernel, could you please help me here !

[ojeda]

Testing limitation: I'm working on macOS with a case-insensitive filesystem, which prevents me from doing a full local kernel build due to the repository having files with conflicting case-sensitive names (e.g., xt_CONNMARK.h vs xt_connmark.h). The code changes are ready, but I haven't been able to test with CLIPPY=1 locally.

I think a few people work natively with macOS builds (Cc @tamird), but I would just recommend using a Linux VM for Linux-related work.

Before submitting, I wanted to confirm: Should I create a GitHub Pull Request, or send patches via email/mailing list?
Im new to contributing to kernel, could you please help me here !

We don't use PRs since we got merged upstream -- please see https://rust-for-linux.com/contributing (it has links to the relevant files in the kernel docs etc.) and feel free to ask for help in our Zulip if needed (https://rust-for-linux.com/contact).

Thanks!

[tamird]

You can overcome the case sensitive issue by creating a case-sensitive APFS volume inside your primary case-insensitive volume. APFS volumes resize automatically. I have my Linux repo mounted at /Volumes/Linux which is case-sensitive while the rest of the system is case-insensitive. I use https://github.com/bee-headers/homebrew-bee-headers to allow building on macOS.

[AryanBagade]

Thanks