[PATCH 1/1] rust: module_param: support bool parameters

[Wenzhao Liao]

Add support for parsing boolean module parameters in the Rust
module! macro.

Currently, only integer types are supported by the `module_param!`
macros. This patch implements the `ModuleParam` trait for `bool`
by delegating the string parsing to the existing C implementation
via `kstrtobool_bytes()`. It also wires up `PARAM_OPS_BOOL` so that
the Rust parameter system correctly links to the C `param_ops_bool`
structure.

For demonstration and verification, a boolean parameter is added
to `samples/rust/rust_minimal.rs`.

Assisted-by: Codex:GPT-5
Signed-off-by: Wenzhao Liao <wenzhaoliao@xxxxxxxxxx>
---
 rust/kernel/module_param.rs  | 9 ++++++++-
 rust/macros/lib.rs           | 1 +
 rust/macros/module.rs        | 1 +
 samples/rust/rust_minimal.rs | 8 ++++++++
 4 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/rust/kernel/module_param.rs b/rust/kernel/module_param.rs
index 6a8a7a875643..04ce9eda6731 100644
--- a/rust/kernel/module_param.rs
+++ b/rust/kernel/module_param.rs
@@ -5,7 +5,7 @@
 //! C header: [`include/linux/moduleparam.h`](srctree/include/linux/moduleparam.h)
 
 use crate::prelude::*;
-use crate::str::BStr;
+use crate::str::{kstrtobool_bytes, BStr};
 use bindings;
 use kernel::sync::SetOnce;
 
@@ -106,6 +106,12 @@ fn try_from_param_arg(arg: &BStr) -> Result<Self> {
 impl_int_module_param!(isize);
 impl_int_module_param!(usize);
 
+impl ModuleParam for bool {
+    fn try_from_param_arg(arg: &BStr) -> Result<Self> {
+        kstrtobool_bytes(arg)
+    }
+}
+
 /// A wrapper for kernel parameters.
 ///
 /// This type is instantiated by the [`module!`] macro when module parameters are
@@ -180,3 +186,4 @@ macro_rules! make_param_ops {
 make_param_ops!(PARAM_OPS_U64, u64);
 make_param_ops!(PARAM_OPS_ISIZE, isize);
 make_param_ops!(PARAM_OPS_USIZE, usize);
+make_param_ops!(PARAM_OPS_BOOL, bool);
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs
index 0c36194d9971..95bc3f066b49 100644
--- a/rust/macros/lib.rs
+++ b/rust/macros/lib.rs
@@ -52,6 +52,7 @@
 /// - [`u64`]
 /// - [`isize`]
 /// - [`usize`]
+/// - [`bool`]
 ///
 /// C header: [`include/linux/moduleparam.h`](srctree/include/linux/moduleparam.h)
 ///
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index e16298e520c7..feafa0c1623c 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -197,6 +197,7 @@ fn param_ops_path(param_type: &str) -> Path {
         "u64" => parse_quote!(::kernel::module_param::PARAM_OPS_U64),
         "isize" => parse_quote!(::kernel::module_param::PARAM_OPS_ISIZE),
         "usize" => parse_quote!(::kernel::module_param::PARAM_OPS_USIZE),
+        "bool" => parse_quote!(::kernel::module_param::PARAM_OPS_BOOL),
         t => panic!("Unsupported parameter type {}", t),
     }
 }
diff --git a/samples/rust/rust_minimal.rs b/samples/rust/rust_minimal.rs
index 8eb9583571d7..fedf5be1f713 100644
--- a/samples/rust/rust_minimal.rs
+++ b/samples/rust/rust_minimal.rs
@@ -15,6 +15,10 @@
             default: 1,
             description: "This parameter has a default of 1",
         },
+        test_bool_parameter: bool {
+            default: false,
+            description: "This boolean parameter defaults to false",
+        },
     },
 }
 
@@ -30,6 +34,10 @@ fn init(_module: &'static ThisModule) -> Result<Self> {
             "test_parameter: {}\n",
             *module_parameters::test_parameter.value()
         );
+        pr_info!(
+            "test_bool_parameter: {}\n",
+            *module_parameters::test_bool_parameter.value()
+        );
 
         let mut numbers = KVec::new();
         numbers.push(72, GFP_KERNEL)?;
-- 
2.34.1