Fix clippy.sh script and fix a number of clippy warnings

src/syscall/fs.rs

@@ -29,12 +29,12 @@ pub fn file_op(a: usize, fd: FileHandle, c: usize, d: usize) -> Result<usize> {
     let mut packet = Packet {
         id: 0,
         pid: pid.into(),
-        uid: uid,
-        gid: gid,
-        a: a,
+        uid,
+        gid,
+        a,
         b: file.description.read().number,
-        c: c,
-        d: d
+        c,
+        d
     };
 
     scheme.handle(&mut packet);
@@ -406,8 +406,7 @@ pub fn frename(fd: FileHandle, path: &[u8]) -> Result<usize> {
         let contexts = context::contexts();
         let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
         let context = context_lock.read();
-        let file = context.get_file(fd).ok_or(Error::new(EBADF))?;
-        file
+        context.get_file(fd).ok_or(Error::new(EBADF))?
     };
 
     let (path_canon, uid, gid, scheme_ns) = {

src/syscall/process.rs

@@ -149,7 +149,7 @@ pub fn clone(flags: CloneFlags, stack_base: usize) -> Result<ContextId> {
                     // Change the return address of the child
                     // (previously syscall) to the arch-specific
                     // clone_ret callback
-                    let func_ptr = new_stack.as_mut_ptr().offset(offset as isize);
+                    let func_ptr = new_stack.as_mut_ptr().add(offset);
                     *(func_ptr as *mut usize) = interrupt::syscall::clone_ret as usize;
                 }
 
@@ -1044,7 +1044,6 @@ pub fn fexec(fd: FileHandle, arg_ptrs: &[[usize; 2]], var_ptrs: &[[usize; 2]]) -
         // Argument must be moved into kernel space before exec unmaps all memory
         args.push(arg.to_vec().into_boxed_slice());
     }
-    drop(arg_ptrs);
 
     let mut vars = Vec::new();
     for var_ptr in var_ptrs {
@@ -1052,7 +1051,9 @@ pub fn fexec(fd: FileHandle, arg_ptrs: &[[usize; 2]], var_ptrs: &[[usize; 2]]) -
         // Argument must be moved into kernel space before exec unmaps all memory
         vars.push(var.to_vec().into_boxed_slice());
     }
-    drop(var_ptrs);
+
+    // Neither arg_ptrs nor var_ptrs should be used after this point, the kernel
+    // now has owned copies in args and vars
 
     fexec_kernel(fd, args.into_boxed_slice(), vars.into_boxed_slice(), None)
 }
@@ -1125,10 +1126,8 @@ pub fn exit(status: usize) -> ! {
             if let Some(parent_lock) = contexts.get(ppid) {
                 let waitpid = {
                     let mut parent = parent_lock.write();
-                    if vfork {
-                        if ! parent.unblock() {
-                            println!("{}: {} not blocked for exit vfork unblock", pid.into(), ppid.into());
-                        }
+                    if vfork && ! parent.unblock() {
+                        println!("{}: {} not blocked for exit vfork unblock", pid.into(), ppid.into());
                     }
                     Arc::clone(&parent.waitpid)
                 };

src/syscall/validate.rs

@@ -28,6 +28,7 @@ fn validate(address: usize, size: usize, flags: EntryFlags) -> Result<()> {
 }
 
 /// Convert a pointer and length to slice, if valid
+//TODO: Mark unsafe
 pub fn validate_slice<T>(ptr: *const T, len: usize) -> Result<&'static [T]> {
     if len == 0 {
         Ok(&[])
@@ -38,6 +39,7 @@ pub fn validate_slice<T>(ptr: *const T, len: usize) -> Result<&'static [T]> {
 }
 
 /// Convert a pointer and length to slice, if valid
+//TODO: Mark unsafe
 pub fn validate_slice_mut<T>(ptr: *mut T, len: usize) -> Result<&'static mut [T]> {
     if len == 0 {
         Ok(&mut [])