partial `vmo_op_range`

zircon-loader/src/lib.rs

@@ -156,6 +156,9 @@ pub fn run_userboot(images: &Images<impl AsRef<[u8]>>, cmdline: &str) -> Arc<Pro
     // FIXME correct rights for decompressor engine
     handles[K_USERBOOT_DECOMPRESSOR] =
         Handle::new(decompressor_vmo, Rights::DEFAULT_VMO | Rights::EXECUTE);
+    // TODO CrashLogVmo handle
+
+    // check: handle to root proc should be only
 
     let mut data = Vec::from(cmdline);
     data.push(0);

zircon-object/src/vm/vmo/mod.rs

@@ -41,6 +41,9 @@ pub trait VMObject: KernelObject {
 
     /// Commit allocating physical memory.
     fn commit(&self, offset: usize, len: usize);
+
+    /// Decommit allocated physical memory.
+    fn decommit(&self, offset: usize, len: usize);
 }
 
 #[cfg(test)]

zircon-object/src/vm/vmo/paged.rs

@@ -94,6 +94,15 @@ impl VMObject for VMObjectPaged {
             inner.commit(start_page + i);
         }
     }
+
+    fn decommit(&self, offset: usize, len: usize) {
+        let start_page = offset / PAGE_SIZE;
+        let pages = len / PAGE_SIZE;
+        let mut inner = self.inner.lock();
+        for i in 0..pages {
+            inner.decommit(start_page + i);
+        }
+    }
 }
 
 impl VMObjectPagedInner {
@@ -142,6 +151,10 @@ impl VMObjectPagedInner {
         self.frames[page_idx]
             .get_or_insert_with(|| PhysFrame::alloc().expect("failed to alloc frame"))
     }
+
+    fn decommit(&mut self, page_idx: usize) {
+        self.frames[page_idx] = None;
+    }
 }
 
 #[cfg(test)]

zircon-object/src/vm/vmo/physical.rs

@@ -65,7 +65,13 @@ impl VMObject for VMObjectPhysical {
     }
 
     // TODO empty function should be denied
-    fn commit(&self, _offset: usize, _len: usize) {}
+    fn commit(&self, _offset: usize, _len: usize) {
+        unimplemented!()
+    }
+
+    fn decommit(&self, _offset: usize, _len: usize) {
+        unimplemented!()
+    }
 }
 
 #[cfg(test)]

zircon-syscall/src/lib.rs

@@ -151,6 +151,9 @@ impl Syscall<'_> {
                 a5 as _,
                 a6.into(),
             ),
+            SyscallType::VMO_OP_RANGE => {
+                self.sys_vmo_op_range(a0 as _, a1 as _, a2 as _, a3 as _, a4.into(), a5 as _)
+            }
             _ => {
                 warn!("syscall unimplemented: {:?}", sys_type);
                 Err(ZxError::NOT_SUPPORTED)

zircon-syscall/src/vmo.rs

@@ -131,6 +131,44 @@ impl Syscall<'_> {
         vmo.set_len(pages(size as usize));
         Ok(0)
     }
+
+    pub fn sys_vmo_op_range(
+        &self,
+        handle_value: HandleValue,
+        op: u32,
+        offset: usize,
+        len: usize,
+        _buffer: UserOutPtr<u8>,
+        _buffer_size: usize,
+    ) -> ZxResult<usize> {
+        info!(
+            "vmo.op_range: handle={}, op={:#X}, offset={:#x}, len={:#x}, buffer_size={:#x}",
+            handle_value, op, offset, len, _buffer_size,
+        );
+        let (vmo, rights) = self.thread.proc().get_vmo_and_rights(handle_value)?;
+        if !page_aligned(offset) || !page_aligned(len) {
+            return Err(ZxError::INVALID_ARGS);
+        }
+        match op {
+            VMO_OP_COMMIT => {
+                if rights.contains(Rights::WRITE) {
+                    vmo.commit(offset, len);
+                    Ok(0)
+                } else {
+                    Err(ZxError::ACCESS_DENIED)
+                }
+            }
+            VMO_OP_DECOMMIT => {
+                if rights.contains(Rights::WRITE) {
+                    vmo.decommit(offset, len);
+                    Ok(0)
+                } else {
+                    Err(ZxError::ACCESS_DENIED)
+                }
+            }
+            _ => unimplemented!(),
+        }
+    }
 }
 
 bitflags! {
@@ -143,3 +181,7 @@ bitflags! {
         const NO_WRITE                   = 1 << 5;
     }
 }
+
+/// VMO Opcodes (for vmo_op_range)
+const VMO_OP_COMMIT: u32 = 1;
+const VMO_OP_DECOMMIT: u32 = 2;