From 2fd6f55c048d0c863ffbc8590b1bd2edb5ff13e5 Mon Sep 17 00:00:00 2001
From: Gary Guo <gary@garyguo.net>
Date: Fri, 13 Sep 2024 22:29:22 +0100
Subject: [PATCH] rust: map `__kernel_size_t` and friends also to usize/isize
Currently bindgen has special logic to recognise `size_t` and `ssize_t`
and map them to Rust `usize` and `isize`. Similarly, `ptrdiff_t` is
mapped to `isize`.
However this falls short for `__kernel_size_t`, `__kernel_ssize_t` and
`__kernel_ptrdiff_t`. To ensure that they are mapped to usize/isize
rather than 32/64 integers depending on platform, blocklist them in
bindgen parameters and manually provide their definition.
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Link: https://lore.kernel.org/r/20240913213041.395655-3-gary@garyguo.net
[ Formatted comment. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
---
rust/bindgen_parameters | 5 +++++
rust/bindings/lib.rs | 5 +++++
rust/uapi/lib.rs | 5 +++++
3 files changed, 15 insertions(+)
diff --git a/rust/bindgen_parameters b/rust/bindgen_parameters
index b7c7483123b7a..0f96af8b9a7fe 100644
--- a/rust/bindgen_parameters
+++ b/rust/bindgen_parameters
@@ -1,5 +1,10 @@
# SPDX-License-Identifier: GPL-2.0
+# We want to map these types to `isize`/`usize` manually, instead of
+# define them as `int`/`long` depending on platform bitwidth.
+--blocklist-type __kernel_s?size_t
+--blocklist-type __kernel_ptrdiff_t
+
--opaque-type xregs_state
--opaque-type desc_struct
--opaque-type arch_lbr_state
diff --git a/rust/bindings/lib.rs b/rust/bindings/lib.rs
index d6da3011281a9..014af0d1fc70c 100644
--- a/rust/bindings/lib.rs
+++ b/rust/bindings/lib.rs
@@ -27,6 +27,11 @@
#[allow(dead_code)]
#[allow(clippy::undocumented_unsafe_blocks)]
mod bindings_raw {
+ // Manual definition for blocklisted types.
+ type __kernel_size_t = usize;
+ type __kernel_ssize_t = isize;
+ type __kernel_ptrdiff_t = isize;
+
// Use glob import here to expose all helpers.
// Symbols defined within the module will take precedence to the glob import.
pub use super::bindings_helper::*;
diff --git a/rust/uapi/lib.rs b/rust/uapi/lib.rs
index fea2de330d193..13495910271fa 100644
--- a/rust/uapi/lib.rs
+++ b/rust/uapi/lib.rs
@@ -25,4 +25,9 @@
unsafe_op_in_unsafe_fn
)]
+// Manual definition of blocklisted types.
+type __kernel_size_t = usize;
+type __kernel_ssize_t = isize;
+type __kernel_ptrdiff_t = isize;
+
include!(concat!(env!("OBJTREE"), "/rust/uapi/uapi_generated.rs"));
--
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