On Mon, 20 May 2024 at 04:22, Jan Kara <jack@xxxxxxx> wrote:
>
> * A few small cleanups
This IS NOT A CLEANUP! It's a huge mistake:
> Nikita Kiryushin (1):
> fanotify: remove unneeded sub-zero check for unsigned value
The old code did
WARN_ON_ONCE(len < 0 || len >= FANOTIFY_EVENT_ALIGN);
and that is very legible and very understandable to humans.
The new code is
WARN_ON_ONCE(len >= FANOTIFY_EVENT_ALIGN);
and now a human that reads that line needs to go back and check what
the type of 'len' is to notice that it's unsigned. It is not at all
clear from the context, and the declaration of 'len' is literally 80
lines up. Not very close at all, in other words.
And a compiler doesn't care. A compiler will know the type, and not
generate pointless code.
So this kind of change SHOULD NOT BE DONE. This was making the code
less legible for no good reason.
The reason for this change is quoted as
Found by Linux Verification Center (linuxtesting.org) with SVACE.
and honestly, that only means that linuxtesting.org is actively
detrimental, and whatever "SVACE" is is just incompetent garbage.
Please stop accepting these kinds of patches.
I have done this pull, but I reverted that damage.
Linus
