Re: [PATCH v5 3/8] rust: uaccess: add UserSliceWriter::write_buffer() for raw pointer writes

[Danilo Krummrich]

On Sat Jan 17, 2026 at 3:23 PM CET, Alice Ryhl wrote:
> On Sat, Jan 17, 2026 at 01:23:57PM +0000, Alice Ryhl wrote:
>> On Fri, Jan 16, 2026 at 03:49:54PM -0600, Timur Tabi wrote:
>> > +    pub unsafe fn write_buffer(
>> > +        &mut self,
>> > +        data: *const u8,
>> > +        len: usize,
>> > +        offset: usize,
>> > +        count: usize,
>> > +    ) -> Result {
>> 
>> Why not this signature?
>> 
>>      unsafe fn write_raw_slice(&mut self, data: *const [u8]) -> Result;
>> 
>> You can implement `write_slice` in terms of it.
>
> To clarify, I think this would be a simpler signature for
> `write_buffer()`. And `write_raw_slice()` can be used both for DMA and
> to simplify the existing `write_slice`.

I.e. you can use it also to create a safe helper for DMA:

        fn write_dma(
            &mut self,
            data: &dma::CoherentAllocation<u8>,
            offset: usize,
            count: usize
        ) -> Result;