blob: Use bytemuck and provide slice-variant

Author: Drakulix

drm-ffi/src/mode.rs

@@ -639,12 +639,9 @@ pub fn get_property_blob(
 }
 
 /// Create a property blob
-pub fn create_property_blob(
-    fd: BorrowedFd<'_>,
-    data: &mut [u8],
-) -> io::Result<drm_mode_create_blob> {
+pub fn create_property_blob(fd: BorrowedFd<'_>, data: &[u8]) -> io::Result<drm_mode_create_blob> {
     let mut blob = drm_mode_create_blob {
-        data: data.as_mut_ptr() as _,
+        data: data.as_ptr() as _,
         length: data.len() as _,
         ..Default::default()
     };

src/control/mod.rs

@@ -56,7 +56,6 @@ use std::error;
 use std::fmt;
 use std::io;
 use std::iter::Zip;
-use std::mem;
 use std::ops::RangeBounds;
 use std::os::unix::io::{AsFd, BorrowedFd, FromRawFd, OwnedFd, RawFd};
 use std::time::Duration;
@@ -534,9 +533,23 @@ pub trait Device: super::Device {
     }
 
     /// Create a property blob value from a given data blob
-    fn create_property_blob<T: ?Sized>(&self, data: &T) -> io::Result<property::Value<'static>> {
-        let size = mem::size_of_val(data);
-        let data = unsafe { std::slice::from_raw_parts_mut(data as *const _ as *mut u8, size) };
+    fn create_property_blob<T: bytemuck::NoUninit>(
+        &self,
+        data: &T,
+    ) -> io::Result<property::Value<'static>> {
+        let data = bytemuck::bytes_of(data);
+        let blob = ffi::mode::create_property_blob(self.as_fd(), data)?;
+
+        Ok(property::Value::Blob(blob.blob_id.into()))
+    }
+
+    /// Create a property blob value from a given data slice
+    fn create_property_blob_from_slice<T: bytemuck::NoUninit>(
+        &self,
+        data: &[T],
+    ) -> io::Result<property::Value<'static>> {
+        let data = bytemuck::try_cast_slice(data)
+            .map_err(|_| io::Error::from(io::ErrorKind::InvalidData))?;
         let blob = ffi::mode::create_property_blob(self.as_fd(), data)?;
 
         Ok(property::Value::Blob(blob.blob_id.into()))