Re: TCP quickack race ? (Was Problem: sending mail ...)

Alan Cox (alan@lxorguk.ukuu.org.uk)
Fri, 26 Feb 1999 02:05:42 +0000 (GMT)

> It all runs from BH context only, the rest of the quickack code does
> the same exact "non-atomic" thing. The code paths in question always
> run in BH with knowledge that they have the socket to themselves. All
> user contexts will do lock_sock() (and thus synchronize_bh() ) before

Which interestingly got some surgery in 2.2.2

> doing anything with these bits of state. In fact I do not know of any
> TCP code paths from user context (besides backlog processing, which
> again is BH protected) which mess with tp->ato

Hohum

tcp_recvmsg->cleanup_rbuf -> tcp_read_wakeuk -> tcp_send_ack

Now that does appear to be a locked path.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/