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| -rw-r--r-- | rust/kernel/uaccess.rs | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/rust/kernel/uaccess.rs b/rust/kernel/uaccess.rs index dde8a0abb46d..38d1404ed9b4 100644 --- a/rust/kernel/uaccess.rs +++ b/rust/kernel/uaccess.rs @@ -481,6 +481,23 @@ impl UserSliceWriter { Ok(()) } + /// Writes raw data to this user pointer from a kernel buffer partially. + /// + /// This is the same as [`Self::write_slice`] but considers the given `offset` into `data` and + /// truncates the write to the boundaries of `self` and `data`. + /// + /// On success, returns the number of bytes written. + pub fn write_slice_partial(&mut self, data: &[u8], offset: usize) -> Result<usize> { + let end = offset.saturating_add(self.len()).min(data.len()); + + let Some(src) = data.get(offset..end) else { + return Ok(0); + }; + + self.write_slice(src)?; + Ok(src.len()) + } + /// Writes the provided Rust value to this userspace pointer. /// /// Fails with [`EFAULT`] if the write happens on a bad address, or if the write goes out of |