Re: [PATCH v5 2/2] uaccess: rust: add UserSliceReader::strcpy_into_buf

[Benno Lossin]

On Tue Jun 17, 2025 at 10:55 AM CEST, Alice Ryhl wrote:
> On Tue, Jun 17, 2025 at 9:38 AM Benno Lossin <lossin@xxxxxxxxxx> wrote:
>> What about the case `self.length == 0`? Will `raw_strncpy_from_user`
>> return early with a page fault, or will it return with `len == 0`?
>> Because if it is the latter, then this will result in UB.
>
> If `self.length == 0`, then you will either:
> 1. If buf.is_empty() then you return EINVAL at the top.
> 2. Otherwise, you return EFAULT from the `len < buf.len()` case.

Ah that makes sense. Thanks for explaining.

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Cheers,
Benno