Re: [PATCH net-next V2 12/13] selftests: drv-net: psp: Fix responder parsing

On Mon, 2026-08-10 at 13:33 -0700, Jakub Kicinski wrote:

On Mon, 10 Aug 2026 11:42:36 +0000 Cosmin Ratiu wrote:

quoted

quoted

quoted

+#define cmd(_name,
_extra_sz)						\
 		({					
	
	\
 			ssize_t sz =
sizeof(_name);			\
-			bool match = n >= sz
&&	!memcmp(buf, _name, sz); \
+			bool match = off >= sz + (_extra_sz)
&&		\
+				!memcmp(buf, _name,
sz);		\  

Please don't replace off by n.  

I actually replaced n by off. Did you mean "don't replace n by
off"?

Of course!

quoted

Because the two are identical after the recv error checking. I
don't
see the point of maintaining two variables when one suffices.
Either n
or off can describe the number of bytes in buf. off is static and
persists across chunks, while n is temporary.

The variables have semantic meaning, which makes it easier to follow
the code.

quoted

So to clarify, do you want to keep both?

Yes.

I'm sorry, but the code is wrong.
cmd() matches on n (which never changes!) but __consume() only
decrements off. Strap a loop on top and the result is just confusion
and a source of bugs (e.g. the one I'm trying to fix with this patch).

A single variable should be used to keep track of the length of data
left to parse.

Cosmin.