fix(hal): offset addrs by isize instead of i32 (#509)

This changes the `VAddr::offset` and `PAddr::offset` methods to takee an
`isize` offset instead of an `i32` offset. I don't know why I used `i32`
here, that was stupid.

Fixes #507

Author: hawkw

hal-core/src/addr.rs

@@ -76,10 +76,10 @@ pub trait Address:
         self.align_down(core::mem::align_of::<T>())
     }
 
-    /// Offsets this address by `offset`.
+    /// Offsets this address by `offset` bytes.
     ///
     /// If the specified offset would overflow, this function saturates instead.
-    fn offset(self, offset: i32) -> Self {
+    fn offset(self, offset: isize) -> Self {
         if offset > 0 {
             self + offset as usize
         } else {
@@ -333,11 +333,11 @@ macro_rules! impl_addrs {
                     Address::align_down(self, align)
                 }
 
-                /// Offsets this address by `offset`.
+                /// Offsets this address by `offset` bytes.
                 ///
                 /// If the specified offset would overflow, this function saturates instead.
                 #[inline]
-                pub fn offset(self, offset: i32) -> Self {
+                pub fn offset(self, offset: isize) -> Self {
                     Address::offset(self, offset)
                 }
 

hal-core/src/mem.rs

@@ -84,13 +84,13 @@ impl<A: Address> Region<A> {
     }
 
     pub fn split_front(&mut self, size: usize) -> Option<Self> {
-        assert!(size <= core::i32::MAX as usize);
+        assert!(size <= isize::MAX as usize);
         if size > self.size {
             return None;
         }
         let base = self.base;
         tracing::trace!(size, self.size, "splitting down by");
-        self.base = self.base.offset(size as i32);
+        self.base = self.base.offset(size as isize);
         self.size -= size;
         Some(Self {
             base,
@@ -100,12 +100,12 @@ impl<A: Address> Region<A> {
     }
 
     pub fn split_back(&mut self, size: usize) -> Option<Self> {
-        assert!(size <= core::i32::MAX as usize);
+        assert!(size <= isize::MAX as usize);
         if size >= self.size {
             return None;
         }
         let rem_size = self.size - size;
-        let base = self.base.offset(size as i32);
+        let base = self.base.offset(size as isize);
         tracing::trace!(
             size,
             self.size,

hal-x86_64/src/task.rs

@@ -37,7 +37,7 @@ impl StateSegment {
     /// Returns the virtual address of the I/O permission bitmap.
     #[inline]
     pub fn iomap_addr(&self) -> VAddr {
-        VAddr::of(self).offset(self.iomap_offset as i32)
+        VAddr::of(self).offset(self.iomap_offset as isize)
     }
 
     /// Loads the provided [`selector`](segment::Selector) into the current task

src/arch/x86_64/interrupt.rs

@@ -48,7 +48,7 @@ static TSS: sync::Lazy<task::StateSegment> = sync::Lazy::new(|| {
     tss.interrupt_stacks[Idt::DOUBLE_FAULT_IST_OFFSET] = unsafe {
         // safety: asdf
         VAddr::from_usize_unchecked(core::ptr::addr_of!(DOUBLE_FAULT_STACK) as usize)
-            .offset(DOUBLE_FAULT_STACK_SIZE as i32)
+            .offset(DOUBLE_FAULT_STACK_SIZE as isize)
     };
     tracing::debug!(?tss, "TSS initialized");
     tss