Hello!
I think the patch breaks things because it consumes (or rather skips)
the urgent data ( in the code after the label found_ok_skb: ).
Since this happens before the SIGURG handler is run, it won't find
any urgent data.
What do you think?
Yes, you are absolutely right. I missed exactly this thing.
The patch by Linus seems to be fine though.
I think the patch suggested by Linus is 100% correct and
in fact it is the only solution.
Alexey