[v3,03/16] rust: pass module name to `Module::init`

Commit Message

Danilo Krummrich Oct. 22, 2024, 9:31 p.m. UTC

In a subsequent patch we introduce the `Registration` abstraction used
to register driver structures. Some subsystems require the module name on
driver registration (e.g. PCI in __pci_register_driver()), hence pass
the module name to `Module::init`.

Signed-off-by: Danilo Krummrich <[e-mail]>
---
 drivers/block/rnull.rs       |  2 +-
 rust/kernel/lib.rs           | 14 ++++++++++----
 rust/kernel/net/phy.rs       |  2 +-
 rust/macros/module.rs        |  6 ++++--
 samples/rust/rust_minimal.rs |  2 +-
 samples/rust/rust_print.rs   |  2 +-
 6 files changed, 18 insertions(+), 10 deletions(-)

Comments

Alice Ryhl Oct. 29, 2024, 12:55 p.m. UTC | #1

On Tue, Oct 22, 2024 at 11:32 PM Danilo Krummrich <[e-mail]> wrote:
>
> In a subsequent patch we introduce the `Registration` abstraction used
> to register driver structures. Some subsystems require the module name on
> driver registration (e.g. PCI in __pci_register_driver()), hence pass
> the module name to `Module::init`.
>
> Signed-off-by: Danilo Krummrich <[e-mail]>

The C-side just uses KBUILD_MODNAME for this. Could we do something similar?

Alice

Patch

diff --git a/drivers/block/rnull.rs b/drivers/block/rnull.rs
index 5de7223beb4d..0e0e9ed7851e 100644
--- a/drivers/block/rnull.rs
+++ b/drivers/block/rnull.rs
@@ -36,7 +36,7 @@  struct NullBlkModule {
 }
 
 impl kernel::Module for NullBlkModule {
-    fn init(_module: &'static ThisModule) -> Result<Self> {
+    fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> {
         pr_info!("Rust null_blk loaded\n");
         let tagset = Arc::pin_init(TagSet::new(1, 256, 1), flags::GFP_KERNEL)?;
 
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 4fdb0d91f2ad..83f76dc7bad2 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -80,7 +80,7 @@  pub trait Module: Sized + Sync + Send {
     /// should do.
     ///
     /// Equivalent to the `module_init` macro in the C API.
-    fn init(module: &'static ThisModule) -> error::Result<Self>;
+    fn init(name: &'static str::CStr, module: &'static ThisModule) -> error::Result<Self>;
 }
 
 /// A module that is pinned and initialised in-place.
@@ -88,13 +88,19 @@  pub trait InPlaceModule: Sync + Send {
     /// Creates an initialiser for the module.
     ///
     /// It is called when the module is loaded.
-    fn init(module: &'static ThisModule) -> impl init::PinInit<Self, error::Error>;
+    fn init(
+        name: &'static str::CStr,
+        module: &'static ThisModule,
+    ) -> impl init::PinInit<Self, error::Error>;
 }
 
 impl<T: Module> InPlaceModule for T {
-    fn init(module: &'static ThisModule) -> impl init::PinInit<Self, error::Error> {
+    fn init(
+        name: &'static str::CStr,
+        module: &'static ThisModule,
+    ) -> impl init::PinInit<Self, error::Error> {
         let initer = move |slot: *mut Self| {
-            let m = <Self as Module>::init(module)?;
+            let m = <Self as Module>::init(name, module)?;
 
             // SAFETY: `slot` is valid for write per the contract with `pin_init_from_closure`.
             unsafe { slot.write(m) };
diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs
index 910ce867480a..26631b0e127a 100644
--- a/rust/kernel/net/phy.rs
+++ b/rust/kernel/net/phy.rs
@@ -899,7 +899,7 @@  struct Module {
                 [$($crate::net::phy::create_phy_driver::<$driver>()),+];
 
             impl $crate::Module for Module {
-                fn init(module: &'static ThisModule) -> Result<Self> {
+                fn init(_name: &'static CStr, module: &'static ThisModule) -> Result<Self> {
                     // SAFETY: The anonymous constant guarantees that nobody else can access
                     // the `DRIVERS` static. The array is used only in the C side.
                     let drivers = unsafe { &mut DRIVERS };
diff --git a/rust/macros/module.rs b/rust/macros/module.rs
index a03266a78cfb..3292714ff82e 100644
--- a/rust/macros/module.rs
+++ b/rust/macros/module.rs
@@ -333,8 +333,10 @@  mod __module_init {{
                     ///
                     /// This function must only be called once.
                     unsafe fn __init() -> core::ffi::c_int {{
-                        let initer =
-                            <{type_} as kernel::InPlaceModule>::init(&super::super::THIS_MODULE);
+                        let initer = <{type_} as kernel::InPlaceModule>::init(
+                            kernel::c_str!(\"{name}\"),
+                            &super::super::THIS_MODULE
+                        );
                         // SAFETY: No data race, since `__MOD` can only be accessed by this module
                         // and there only `__init` and `__exit` access it. These functions are only
                         // called once and `__exit` cannot be called before or during `__init`.
diff --git a/samples/rust/rust_minimal.rs b/samples/rust/rust_minimal.rs
index 4aaf117bf8e3..1577dc34e563 100644
--- a/samples/rust/rust_minimal.rs
+++ b/samples/rust/rust_minimal.rs
@@ -17,7 +17,7 @@  struct RustMinimal {
 }
 
 impl kernel::Module for RustMinimal {
-    fn init(_module: &'static ThisModule) -> Result<Self> {
+    fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> {
         pr_info!("Rust minimal sample (init)\n");
         pr_info!("Am I built-in? {}\n", !cfg!(MODULE));
 
diff --git a/samples/rust/rust_print.rs b/samples/rust/rust_print.rs
index ba1606bdbd75..73763ea2dc09 100644
--- a/samples/rust/rust_print.rs
+++ b/samples/rust/rust_print.rs
@@ -41,7 +41,7 @@  fn arc_print() -> Result {
 }
 
 impl kernel::Module for RustPrint {
-    fn init(_module: &'static ThisModule) -> Result<Self> {
+    fn init(_name: &'static CStr, _module: &'static ThisModule) -> Result<Self> {
         pr_info!("Rust printing macros sample (init)\n");
 
         pr_emerg!("Emergency message (level 0) without args\n");