Re: [PATCH 4/8] snd: make snd_map_bufs() deal with ITER_UBUF

[Jens Axboe <axboe@kernel.dk>]

On 3/28/23 11:50 AM, Linus Torvalds wrote:
> On Tue, Mar 28, 2023 at 10:36 AM Jens Axboe <axboe@kernel.dk> wrote:
>>
>> @@ -3516,23 +3516,28 @@ static void __user **snd_map_bufs(struct snd_pcm_runtime *runtime,
>>                                   struct iov_iter *iter,
>>                                   snd_pcm_uframes_t *frames, int max_segs)
>>  {
>> +       int nr_segs = iovec_nr_user_vecs(iter);
> 
> This has a WARN_ON_ONCE() for !user_backed, but then..
> 
>>         void __user **bufs;
>> +       struct iovec iov;
>>         unsigned long i;
>>
>>         if (!iter->user_backed)
>>                 return ERR_PTR(-EFAULT);
> 
> here the code tries to deal with it.
> 
> So I think the two should probably be switched around.

True, it was actually like that before I refactored it to include
that common helper. I'll swap them around, thanks.

-- 
Jens Axboe