io: make {set,get}_{fs,gs}_base indirect functions

Signed-off-by: Anhad Singh <[email protected]>

Author: Andy-Python-Programmer

bootstrap.yml

@@ -902,7 +902,7 @@ packages:
         - '--prefix=/usr'
         - '-Dheaders_only=true'
         - '-Ddisable_iconv_option=true'
-        - '-Dbuildtype=debug'
+        - '--buildtype=release'
         - '-Dlinux_kernel_headers=@BUILD_ROOT@/packages/linux-headers/usr/include'
         - '@THIS_SOURCE_DIR@'
     build:
@@ -929,7 +929,7 @@ packages:
         - '--libdir=lib'
         - '-Dmlibc_no_headers=true'
         - '-Ddisable_iconv_option=true'
-        - '-Dbuildtype=debug'
+        - '--buildtype=release'
         - '-Dlinux_kernel_headers=@BUILD_ROOT@/packages/linux-headers/usr/include'
         - '@THIS_SOURCE_DIR@'
     build:

src/aero_kernel/src/arch/x86_64/io.rs

@@ -261,7 +261,7 @@ pub fn rdgsbase() -> VirtAddr {
 
 /// # Safety
 /// The caller must ensure that the swap operation does not cause any undefined behavior.
-#[inline]
+#[inline(always)]
 pub unsafe fn swapgs() {
     asm!("swapgs", options(nostack, preserves_flags));
 }
@@ -271,48 +271,80 @@ pub unsafe fn swapgs() {
 // the `KERNEL_GS_BASE` MSR.
 
 /// Sets the inactive `GS` segment's base address.
-#[inline]
-pub unsafe fn set_inactive_gsbase(base: VirtAddr) {
-    if super::has_fsgsbase() {
+#[indirect]
+pub fn set_inactive_gsbase() -> fn(base: VirtAddr) {
+    unsafe fn with_wrgsbase(base: VirtAddr) {
         swapgs();
         wrgsbase(base);
         swapgs();
-    } else {
+    }
+
+    unsafe fn with_wrmsr(base: VirtAddr) {
         wrmsr(IA32_KERNEL_GSBASE, base.as_u64());
     }
+
+    if super::has_fsgsbase() {
+        with_wrgsbase
+    } else {
+        with_wrmsr
+    }
 }
 
 /// Returns the inactive `GS` segment's base address.
-#[inline]
-pub fn get_inactive_gsbase() -> VirtAddr {
-    if super::has_fsgsbase() {
+#[indirect]
+pub fn get_inactive_gsbase() -> fn() -> VirtAddr {
+    fn with_rdgsbase() -> VirtAddr {
         // SAFETY: The GS base is swapped back to the original value after the read.
         unsafe { swapgs() };
         let base = rdgsbase();
         unsafe { swapgs() };
 
         base
-    } else {
+    }
+
+    fn with_rdmsr() -> VirtAddr {
         VirtAddr::new(unsafe { rdmsr(IA32_KERNEL_GSBASE) })
     }
-}
 
-/// Returns the `FS` segment's base address.
-#[inline]
-pub fn get_fsbase() -> VirtAddr {
     if super::has_fsgsbase() {
-        rdfsbase()
+        with_rdgsbase
     } else {
-        VirtAddr::new(unsafe { rdmsr(IA32_FS_BASE) })
+        with_rdmsr
     }
 }
 
 /// Sets the `FS` segment's base address.
-#[inline]
-pub unsafe fn set_fsbase(base: VirtAddr) {
-    if super::has_fsgsbase() {
+#[indirect]
+pub fn set_fsbase() -> fn(base: VirtAddr) {
+    unsafe fn with_wrfsbase(base: VirtAddr) {
         wrfsbase(base);
-    } else {
+    }
+
+    unsafe fn with_wrmsr(base: VirtAddr) {
         wrmsr(IA32_FS_BASE, base.as_u64());
     }
+
+    if super::has_fsgsbase() {
+        with_wrfsbase
+    } else {
+        with_wrmsr
+    }
+}
+
+/// Returns the `FS` segment's base address.
+#[indirect]
+pub fn get_fsbase() -> fn() -> VirtAddr {
+    fn with_rdfsbase() -> VirtAddr {
+        rdfsbase()
+    }
+
+    fn with_rdmsr() -> VirtAddr {
+        VirtAddr::new(unsafe { rdmsr(IA32_FS_BASE) })
+    }
+
+    if super::has_fsgsbase() {
+        with_rdfsbase
+    } else {
+        with_rdmsr
+    }
 }

src/aero_kernel/src/arch/x86_64/mem.rs

@@ -67,7 +67,7 @@ unsafe extern "C" fn memcpy_movsb(dest: *mut u8, src: *const u8, len: usize) ->
 }
 
 #[indirect]
-extern "C" fn memcpy() -> fn(*mut u8, *const u8, usize) {
+extern "C" fn memcpy() -> fn(dest: *mut u8, src: *const u8, len: usize) {
     if should_store_by_byte() {
         memcpy_movsb
     } else {
@@ -125,7 +125,7 @@ unsafe extern "C" fn memset_stosb(dest: *mut u8, byte: i32, len: usize) -> *mut
 }
 
 #[indirect]
-extern "C" fn memset() -> fn(*mut u8, i32, usize) {
+extern "C" fn memset() -> fn(dest: *mut u8, byte: i32, len: usize) {
     if should_store_by_byte() {
         memset_stosb
     } else {

src/aero_proc/src/indirect.rs

@@ -1,11 +1,28 @@
 use proc_macro::TokenStream;
 use proc_macro2::{Ident, Span};
+use syn::spanned::Spanned;
 
 pub fn parse(_: TokenStream, item: TokenStream) -> TokenStream {
     let item = syn::parse_macro_input!(item as syn::ItemFn);
     let args = item.sig.inputs;
 
+    if !args.is_empty() {
+        abort!(args.span(), "resolver is expected to take no arguments");
+    }
+
     let name = item.sig.ident.to_string();
+    let vis = item.vis;
+
+    let output_fn = match item.sig.output {
+        syn::ReturnType::Type(_, ty) => match ty.as_ref() {
+            syn::Type::BareFn(bare_fn) => bare_fn.clone(),
+            ty => abort!(ty.span(), "expected output function type"),
+        },
+        ty => abort!(ty.span(), "expected output function type"),
+    };
+
+    let output_args = &output_fn.inputs;
+    let output_ret = &output_fn.output;
 
     // Underscores at the beginning of the identifier make it reserved, and the more underscores
     // there are, the more reserveder it is.
@@ -35,7 +52,7 @@ pub fn parse(_: TokenStream, item: TokenStream) -> TokenStream {
         ::core::arch::global_asm!(#inline, sym #resolve_name);
 
         extern "C" {
-            fn #name(#args);
+            #vis fn #name(#output_args) #output_ret;
         }
     }
     .into()