Re: [PATCH] iio: buffer: Fix double-free in iio_buffers_alloc_sysfs_and_mask()

[Yang Yingliang]

Hi,

On 2021/10/13 4:58, Andy Shevchenko wrote:
> On Tue, Oct 12, 2021 at 8:55 PM Joe Perches <joe@xxxxxxxxxxx> wrote:
> > On Tue, 2021-10-12 at 23:48 +0300, Andy Shevchenko wrote:
> > > On Tue, Oct 12, 2021 at 8:43 PM Joe Perches <joe@xxxxxxxxxxx> wrote:
> > > > On Tue, 2021-10-12 at 23:30 +0300, Andy Shevchenko wrote:
> > > > > On Tue, Oct 12, 2021 at 2:37 PM Alexandru Ardelean
> > > > > <ardeleanalex@xxxxxxxxx> wrote:
> > > > > > On Tue, Oct 12, 2021 at 12:18 PM Yang Yingliang
> > > > > > <yangyingliang@xxxxxxxxxx> wrote:
> ...
>
> > > > > I prefer to see
> > > > >
> > > > > - for (; unwind_idx >= 0; unwind_idx--) {
> > > > > + while (unwind_idx--)
> > > > Not the same code as unwind_idx would be decremented before entering
> > > > the code block.
> > > It's kinda cryptic what you are pointing out.
> > Not really,
> It's. It lacks the very same "additional" words to explain what you
> meant and why.
>
> > > What's needed additionally is to change
> > >
> > > - unwind_idx = iio_dev_opaque->attached_buffers_cnt - 1;
> > > + unwind_idx = i;
> > You left out that 'additional change' above from your reply.
> Yes, that's true, but it took some time to decrypt your message.
>
> > > Of course not. See above. The usual pattern is
> > >
> > >    while (i--)
> > >      do_clean_item(i);
> > Of course, but that's not what you replied.
> > I was merely pointing out that your reply included a logic change
> > converting a loop from for to while.
> I expect that developers actually think about the changes they do and
> double check what's proposed by reviewers. If they just copy'n'paste
> whatever others propose, I wouldn't take any patch from such a
> developer.
I think in alloc path is using for loop, and in error/free path also 
using for loop is better to read the code.
>