lsm,rust: mark SecurityCtx methods inline

When you build the kernel using the llvm-19.1.4-rust-1.83.0-x86_64
toolchain provided by kernel.org with ARCH=arm64, the following symbols
are generated:

$ nm vmlinux | grep ' _R'.*SecurityCtx | rustfilt
... T <kernel::security::SecurityCtx>::from_secid
... T <kernel::security::SecurityCtx as core::ops::drop::Drop>::drop

However, these Rust symbols are trivial wrappers around the functions
security_secid_to_secctx and security_release_secctx respectively. It
doesn't make sense to go through a trivial wrapper for these functions,
so mark them inline. Also mark other trivial methods inline to prevent
similar cases in the future.

After applying this patch, the above command will produce no output.

Reviewed-by: Andreas Hindborg <[email protected]>
Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Fiona Behrens <[email protected]>
[PM: trimmed long description lines, subj tweak]
Signed-off-by: Paul Moore <[email protected]>

Author: Darksonn

rust/kernel/security.rs

@@ -23,6 +23,7 @@ pub struct SecurityCtx {
 
 impl SecurityCtx {
     /// Get the security context given its id.
+    #[inline]
     pub fn from_secid(secid: u32) -> Result<Self> {
         // SAFETY: `struct lsm_context` can be initialized to all zeros.
         let mut ctx: bindings::lsm_context = unsafe { core::mem::zeroed() };
@@ -35,16 +36,19 @@ impl SecurityCtx {
     }
 
     /// Returns whether the security context is empty.
+    #[inline]
     pub fn is_empty(&self) -> bool {
         self.ctx.len == 0
     }
 
     /// Returns the length of this security context.
+    #[inline]
     pub fn len(&self) -> usize {
         self.ctx.len as usize
     }
 
     /// Returns the bytes for this security context.
+    #[inline]
     pub fn as_bytes(&self) -> &[u8] {
         let ptr = self.ctx.context;
         if ptr.is_null() {
@@ -61,6 +65,7 @@ impl SecurityCtx {
 }
 
 impl Drop for SecurityCtx {
+    #[inline]
     fn drop(&mut self) {
         // SAFETY: By the invariant of `Self`, this frees a context that came from a successful
         // call to `security_secid_to_secctx` and has not yet been destroyed by