linux/rust
Alice Ryhl 68aabb29a5 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>
2026-01-16 14:54:11 +01:00
..
bindings rust: redefine bindings::compat_ptr_ioctl in Rust 2026-01-16 14:54:11 +01:00
helpers Merge 6.19-rc5 into char-misc-next 2026-01-12 08:51:13 +01:00
kernel rust: redefine bindings::compat_ptr_ioctl in Rust 2026-01-16 14:54:11 +01:00
macros Modules changes for v6.19-rc1 2025-12-06 08:27:07 -08:00
pin-init Driver core changes for 6.19-rc1 2025-12-05 21:29:02 -08:00
proc-macro2 rust: proc-macro2: add README.md 2025-11-24 17:15:40 +01:00
quote rust: quote: add README.md 2025-11-24 17:15:43 +01:00
syn rust: syn: add README.md 2025-11-24 17:15:47 +01:00
uapi Char/Misc/IIO/Binder changes for 6.18-rc1 2025-10-04 16:26:32 -07:00
.gitignore rust: support running Rust documentation tests as KUnit ones 2023-07-19 09:32:53 -06:00
.kunitconfig rust: add kunitconfig 2025-03-19 23:22:21 +01:00
bindgen_parameters mm: declare VMA flags by bit 2025-11-29 10:41:08 -08:00
build_error.rs rust: add build_error crate 2022-12-04 01:59:16 +01:00
compiler_builtins.rs ARM: 9441/1: rust: Enable Rust support for ARMv7 2025-03-26 13:31:16 +00:00
exports.c rust: exports: improve grammar in commentary 2024-10-21 17:35:33 +02:00
ffi.rs rust: replace CStr with core::ffi::CStr 2025-10-22 07:47:27 +02:00
Makefile Rust changes for v6.19 2025-12-03 14:16:49 -08:00