Fixed transmute clippy lint warnings.

The toolchain bump from 1.79 to 1.82 introduced a new clippy lint
regarding transmutes. This commit fixes the emitted lint warnings.

Author: Ioan-Cristian CÎRSTEA

platform/src/command_return.rs

@@ -139,7 +139,7 @@ impl CommandReturn {
         if !self.is_failure() {
             return None;
         }
-        Some(unsafe { transmute(self.r1) })
+        Some(unsafe { transmute::<u32, ErrorCode>(self.r1) })
     }
 
     /// Returns the error code and value if this CommandReturn is of type
@@ -148,7 +148,7 @@ impl CommandReturn {
         if !self.is_failure_u32() {
             return None;
         }
-        Some((unsafe { transmute(self.r1) }, self.r2))
+        Some((unsafe { transmute::<u32, ErrorCode>(self.r1) }, self.r2))
     }
 
     /// Returns the error code and return values if this CommandReturn is of
@@ -157,7 +157,11 @@ impl CommandReturn {
         if !self.is_failure_2_u32() {
             return None;
         }
-        Some((unsafe { transmute(self.r1) }, self.r2, self.r3))
+        Some((
+            unsafe { transmute::<u32, ErrorCode>(self.r1) },
+            self.r2,
+            self.r3,
+        ))
     }
 
     /// Returns the error code and return value if this CommandReturn is of type
@@ -167,7 +171,7 @@ impl CommandReturn {
             return None;
         }
         Some((
-            unsafe { transmute(self.r1) },
+            unsafe { transmute::<u32, ErrorCode>(self.r1) },
             self.r2 as u64 + ((self.r3 as u64) << 32),
         ))
     }
@@ -244,7 +248,7 @@ impl CommandReturn {
         let ec: ErrorCode = if return_variant == E::RETURN_VARIANT {
             // Safety: E::RETURN_VARIANT must be a failure variant, and
             // failure variants must contain a valid ErrorCode in r1.
-            unsafe { transmute(r1) }
+            unsafe { transmute::<u32, ErrorCode>(r1) }
         } else {
             r2 = 0;
             r3 = 0;

platform/src/error_code.rs

@@ -277,7 +277,7 @@ impl TryFrom<u32> for ErrorCode {
 
     fn try_from(value: u32) -> Result<Self, Self::Error> {
         if (1..=1024).contains(&value) {
-            Ok(unsafe { transmute(value) })
+            Ok(unsafe { transmute::<u32, ErrorCode>(value) })
         } else {
             Err(NotAnErrorCode)
         }

platform/src/syscalls_impl.rs

@@ -118,7 +118,7 @@ impl<S: RawSyscalls> Syscalls for S {
                 // then r1 will contain a valid error code. ErrorCode is
                 // designed to be safely transmuted directly from a kernel error
                 // code.
-                return Err(unsafe { core::mem::transmute(r1.as_u32()) });
+                return Err(unsafe { core::mem::transmute::<u32, ErrorCode>(r1.as_u32()) });
             }
 
             // r0 indicates Success with 2 u32s. Confirm the null upcall was
@@ -231,7 +231,7 @@ impl<S: RawSyscalls> Syscalls for S {
                 // then r1 will contain a valid error code. ErrorCode is
                 // designed to be safely transmuted directly from a kernel error
                 // code.
-                return Err(unsafe { core::mem::transmute(r1.as_u32()) });
+                return Err(unsafe { core::mem::transmute::<u32, ErrorCode>(r1.as_u32()) });
             }
 
             // r0 indicates Success with 2 u32s. Confirm a zero buffer was
@@ -318,7 +318,7 @@ impl<S: RawSyscalls> Syscalls for S {
                 // then r1 will contain a valid error code. ErrorCode is
                 // designed to be safely transmuted directly from a kernel error
                 // code.
-                return Err(unsafe { core::mem::transmute(r1.as_u32()) });
+                return Err(unsafe { core::mem::transmute::<u32, ErrorCode>(r1.as_u32()) });
             }
 
             // r0 indicates Success with 2 u32s. Confirm a zero buffer was
@@ -380,7 +380,7 @@ impl<S: RawSyscalls> Syscalls for S {
             // then r1 will contain a valid error code. ErrorCode is
             // designed to be safely transmuted directly from a kernel error
             // code.
-            Err(unsafe { core::mem::transmute(r1.as_u32()) })
+            Err(unsafe { core::mem::transmute::<u32, ErrorCode>(r1.as_u32()) })
         } else {
             Ok(())
         }
@@ -407,7 +407,7 @@ impl<S: RawSyscalls> Syscalls for S {
             // then r1 will contain a valid error code. ErrorCode is
             // designed to be safely transmuted directly from a kernel error
             // code.
-            Err(unsafe { core::mem::transmute(r1.as_u32()) })
+            Err(unsafe { core::mem::transmute::<u32, ErrorCode>(r1.as_u32()) })
         } else {
             Ok(r1.into())
         }
@@ -436,7 +436,7 @@ impl<S: RawSyscalls> Syscalls for S {
             // then r1 will contain a valid error code. ErrorCode is
             // designed to be safely transmuted directly from a kernel error
             // code.
-            Err(unsafe { core::mem::transmute(r1.as_u32()) })
+            Err(unsafe { core::mem::transmute::<u32, ErrorCode>(r1.as_u32()) })
         } else {
             Ok(r1.into())
         }
@@ -464,7 +464,7 @@ impl<S: RawSyscalls> Syscalls for S {
             // then r1 will contain a valid error code. ErrorCode is
             // designed to be safely transmuted directly from a kernel error
             // code.
-            Err(unsafe { core::mem::transmute(r1.as_u32()) })
+            Err(unsafe { core::mem::transmute::<u32, ErrorCode>(r1.as_u32()) })
         } else {
             Ok(())
         }
@@ -493,7 +493,7 @@ impl<S: RawSyscalls> Syscalls for S {
             // then r1 will contain a valid error code. ErrorCode is
             // designed to be safely transmuted directly from a kernel error
             // code.
-            Err(unsafe { core::mem::transmute(r1.as_u32()) })
+            Err(unsafe { core::mem::transmute::<u32, ErrorCode>(r1.as_u32()) })
         } else {
             Ok(())
         }