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| -rw-r--r-- | rust/kernel/uaccess.rs | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/rust/kernel/uaccess.rs b/rust/kernel/uaccess.rs index 38d1404ed9b4..f989539a31b4 100644 --- a/rust/kernel/uaccess.rs +++ b/rust/kernel/uaccess.rs @@ -498,6 +498,31 @@ impl UserSliceWriter { Ok(src.len()) } + /// Writes raw data to this user pointer from a kernel buffer partially. + /// + /// This is the same as [`Self::write_slice_partial`] but updates the given [`file::Offset`] by + /// the number of bytes written. + /// + /// This is equivalent to C's `simple_read_from_buffer()`. + /// + /// On success, returns the number of bytes written. + pub fn write_slice_file(&mut self, data: &[u8], offset: &mut file::Offset) -> Result<usize> { + if offset.is_negative() { + return Err(EINVAL); + } + + let Ok(offset_index) = (*offset).try_into() else { + return Ok(0); + }; + + let written = self.write_slice_partial(data, offset_index)?; + + // OVERFLOW: `offset + written <= data.len() <= isize::MAX <= Offset::MAX` + *offset += written as i64; + + Ok(written) + } + /// 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 |