Re: commit 64ff3b938ec6782e6585a83d5459b98b0c3f6eb8 breaks rlogin

Linus Torvalds
2009-02-09T15:46:04Z

On Mon, 9 Feb 2009, Herbert Xu wrote:
>
> Then the problem isn't my patch at all. My patch only affects
> the side sending the urgent data, according to your straces, rlogin
> is only receiving urgent data, not sending it. So the patch cannot
> have an affect.

The trace is incolclusive about that - just look at it. It's not following
threads/children etc, so it's missing all the relevant pieces.

Which you should have realized, Herbert, since you had the knowledge that
your patch _DOES_ make a difference, enough to bisect to it, and enough
to see that reverting it changes behaviour.

Why are you arguing against facts?

>From the trace:

clone(child_stack=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0xb7d81918) = 6433
rt_sigaction(SIGURG, {0x80491d0, [URG], SA_RESTART}, {SIG_DFL}, 8) = 0
rt_sigaction(SIGUSR1, {0x8048de0, [USR1], SA_RESTART}, {SIG_DFL}, 8) = 0
rt_sigprocmask(SIG_SETMASK, [], [USR1 URG], 8) = 0
--- SIGURG (Urgent I/O condition) @ 0 (0) ---
kill(6433, SIGURG) = 0

IOW, the trace isn't saying anything at all, because all the real work
probably got done in that child process.

> No you're still stracing rlogin, which in this case is the receiver
> of the urgent data. Please strace the sending side, which would be
> presumably be rlogind in this case.

Herbert, how sure are you that there is no URG data on that side?

You clearly spent _zero_ time actually looking at the trace, so...

Linus