diff options
| author | Alice Ryhl <aliceryhl@google.com> | 2026-01-05 14:25:03 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-01-16 14:54:11 +0100 |
| commit | 68aabb29a5469e4b7358e70e64a7fac433e27f06 (patch) | |
| tree | 72303b34479bac95233632668c1e737f30abd7b2 /drivers | |
| parent | b0e930a6360ff5f81045146f0a8fcac4f7897eda (diff) | |
rust: redefine `bindings::compat_ptr_ioctl` in Rust
There is currently an inconsistency between C and Rust, which is that
when Rust requires cfg(CONFIG_COMPAT) on compat_ioctl when using the
compat_ptr_ioctl symbol because '#define compat_ptr_ioctl NULL' does not
get translated to anything by bindgen.
But it's not *just* a matter of translating the '#define' into Rust when
CONFIG_COMPAT=n. This is because when CONFIG_COMPAT=y, the type of
compat_ptr_ioctl is a non-nullable function pointer, and to seamlessly
use it regardless of the config, we need a nullable function pointer.
I think it's important to do something about this; I've seen the mistake
of accidentally forgetting '#[cfg(CONFIG_COMPAT)]' when compat_ptr_ioctl
is used multiple times now.
This explicitly declares 'bindings::compat_ptr_ioctl' as an Option that
is always defined but might be None. This matches C, but isn't ideal:
it modifies the bindings crate. But I'm not sure if there's a better way
to do it. If we just redefine in kernel/, then people may still use the
one in bindings::, since that is where you would normally find it. I am
open to suggestions.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260105-redefine-compat_ptr_ioctl-v1-1-25edb3d91acc@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/android/binder/rust_binder_main.rs | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/android/binder/rust_binder_main.rs b/drivers/android/binder/rust_binder_main.rs index d84c3c360be0..30e4517f90a3 100644 --- a/drivers/android/binder/rust_binder_main.rs +++ b/drivers/android/binder/rust_binder_main.rs @@ -322,8 +322,7 @@ pub static rust_binder_fops: AssertSync<kernel::bindings::file_operations> = { owner: THIS_MODULE.as_ptr(), poll: Some(rust_binder_poll), unlocked_ioctl: Some(rust_binder_ioctl), - #[cfg(CONFIG_COMPAT)] - compat_ioctl: Some(bindings::compat_ptr_ioctl), + compat_ioctl: bindings::compat_ptr_ioctl, mmap: Some(rust_binder_mmap), open: Some(rust_binder_open), release: Some(rust_binder_release), |