Re: [PATCH] gpu: nova-core: firmware: fwsec: use zeroed() to zero-pad buffers

["Danilo Krummrich" <dakr@kernel.org>]

On Wed Oct 7, 2026 at 2:33 AM CEST, Alexandre Courbot wrote:
> On Wed Oct 7, 2026 at 7:20 AM JST, Danilo Krummrich wrote:
>> On Tue Oct 6, 2026 at 12:04 PM CEST, Thorsten Blum wrote:
>>> -            let mut ucode = KVec::with_capacity(aligned_code_size, GFP_KERNEL)?;
>>> -            ucode.extend_from_slice(code, GFP_KERNEL)?;
>>> -            ucode.resize(aligned_code_size, 0, GFP_KERNEL)?;
>>> -
>>> +            let mut ucode = KVec::zeroed(aligned_code_size, GFP_KERNEL)?;
>>> +            ucode[..code.len()].copy_from_slice(code);
>>
>> I kinda dislike that this is now a potential panic, but it does better express
>> the intent.
>
> IMHO the original code expresses the intent just as well, and avoids
> writing the area covered by `code` twice, on top of not introducing a
> potential panic site.

I'm referring to the fact that the original code expresses "I may allocate"
three times, while the intent is that the allocation is exactly
aligned_code_size.

This is much more clear with the new code, if we really want to avoid a
potential panic here, we could use get_mut(), but the ergonomics isn't great.

That said, I wouldn't mind adding something like Vec::extend_within_capacity(),
which fails if there's not enough capacity.

Thanks,
Danilo