From e27b0e3c54f057ef6cb26ac60a2291f1451ea142 Mon Sep 17 00:00:00 2001
From: Kunwu Chan <kunwu.chan@hotmail.com>
Date: Mon, 17 Mar 2025 10:37:02 +0800
Subject: rust: file: optimize rust symbol generation for
 FileDescriptorReservation

When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
with ARCH=arm64, the following symbols are generated:

$ nm vmlinux | grep ' _R'.*FileDescriptorReservation | rustfilt
... T <kernel::fs::file::FileDescriptorReservation>::fd_install
... T <kernel::fs::file::FileDescriptorReservation>::get_unused_fd_flags
... T <kernel::fs::file::FileDescriptorReservation as core::ops::drop::Drop>::drop

These Rust symbols are trivial wrappers around the C functions
fd_install, put_unused_fd and put_task_struct. It
doesn't make sense to go through a trivial wrapper for these
functions, so mark them inline.

Link: https://github.com/Rust-for-Linux/linux/issues/1145
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>
Link: https://lore.kernel.org/r/20250317023702.2360726-1-kunwu.chan@linux.dev
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 rust/kernel/fs/file.rs | 4 ++++
 1 file changed, 4 insertions(+)

(limited to 'rust')

diff --git a/rust/kernel/fs/file.rs b/rust/kernel/fs/file.rs
index e03dbe14d62a..736209a1b983 100644
--- a/rust/kernel/fs/file.rs
+++ b/rust/kernel/fs/file.rs
@@ -392,6 +392,7 @@ pub struct FileDescriptorReservation {
 
 impl FileDescriptorReservation {
     /// Creates a new file descriptor reservation.
+    #[inline]
     pub fn get_unused_fd_flags(flags: u32) -> Result<Self> {
         // SAFETY: FFI call, there are no safety requirements on `flags`.
         let fd: i32 = unsafe { bindings::get_unused_fd_flags(flags) };
@@ -405,6 +406,7 @@ impl FileDescriptorReservation {
     }
 
     /// Returns the file descriptor number that was reserved.
+    #[inline]
     pub fn reserved_fd(&self) -> u32 {
         self.fd
     }
@@ -413,6 +415,7 @@ impl FileDescriptorReservation {
     ///
     /// The previously reserved file descriptor is bound to `file`. This method consumes the
     /// [`FileDescriptorReservation`], so it will not be usable after this call.
+    #[inline]
     pub fn fd_install(self, file: ARef<File>) {
         // SAFETY: `self.fd` was previously returned by `get_unused_fd_flags`. We have not yet used
         // the fd, so it is still valid, and `current` still refers to the same task, as this type
@@ -433,6 +436,7 @@ impl FileDescriptorReservation {
 }
 
 impl Drop for FileDescriptorReservation {
+    #[inline]
     fn drop(&mut self) {
         // SAFETY: By the type invariants of this type, `self.fd` was previously returned by
         // `get_unused_fd_flags`. We have not yet used the fd, so it is still valid, and `current`
-- 
cgit 


From 0b9817caac1d4d6bf7dc8f7f23ffd95a3f5bb43a Mon Sep 17 00:00:00 2001
From: Kunwu Chan <kunwu.chan@hotmail.com>
Date: Mon, 17 Mar 2025 11:04:18 +0800
Subject: rust: optimize rust symbol generation for SeqFile

When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64
with ARCH=arm64, the following symbols are generated:

$nm vmlinux | grep ' _R'.*SeqFile | rustfilt
ffff8000805b78ac T <kernel::seq_file::SeqFile>::call_printf

This Rust symbol is trivial wrappers around the C functions seq_printf.
It doesn't make sense to go through a trivial wrapper for its functions,
so mark it inline.

Link: https://github.com/Rust-for-Linux/linux/issues/1145
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com>
Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com>
Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com>
Link: https://lore.kernel.org/r/20250317030418.2371265-1-kunwu.chan@linux.dev
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 rust/kernel/seq_file.rs | 1 +
 1 file changed, 1 insertion(+)

(limited to 'rust')

diff --git a/rust/kernel/seq_file.rs b/rust/kernel/seq_file.rs
index 04947c672979..efc4dd09850a 100644
--- a/rust/kernel/seq_file.rs
+++ b/rust/kernel/seq_file.rs
@@ -30,6 +30,7 @@ impl SeqFile {
     }
 
     /// Used by the [`seq_print`] macro.
+    #[inline]
     pub fn call_printf(&self, args: core::fmt::Arguments<'_>) {
         // SAFETY: Passing a void pointer to `Arguments` is valid for `%pA`.
         unsafe {
-- 
cgit