Date: Tue, 12 Mar 2019 23:52:35 +0200 (EET) From: Aki Tuomi <aki.tuomi@open-xchange.com> To: Alan Somers <asomers@freebsd.org>, Larry Rosenman <ler@lerctr.org> Cc: Freebsd current <freebsd-current@freebsd.org> Subject: Re: kqueue send over unix socket? Message-ID: <306073586.2112.1552427555424@appsuite-dev-gw2.open-xchange.com> In-Reply-To: <CAOtMX2g2043BCet5HWJRUFApMbUP4cUOWVnRb8m7n1Lf95tM8w@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi!
I am trying exactly that.
dtrace output gives following
# dtrace -s sendmsg.d -p 61387
dtrace: script 'sendmsg.d' matched 30667 probes
CPU ID FUNCTION:NAME
0 16637 uipc_send:return
kernel`sosend_generic+0x556
kernel`kern_sendit+0x296
kernel`sendit+0x19e
kernel`sys_sendmsg+0x61
kernel`amd64_syscall+0xa38
kernel`0xffffffff80f5891d
0 35794 sosend_generic:return
kernel`kern_sendit+0x296
kernel`sendit+0x19e
kernel`sys_sendmsg+0x61
kernel`amd64_syscall+0xa38
kernel`0xffffffff80f5891d
0 32432 kern_sendit:return
kernel`sendit+0x19e
kernel`sys_sendmsg+0x61
kernel`amd64_syscall+0xa38
kernel`0xffffffff80f5891d
0 55533 free:return
kernel`sendit+0x1b0
kernel`sys_sendmsg+0x61
kernel`amd64_syscall+0xa38
kernel`0xffffffff80f5891d
0 16604 sendit:return
kernel`sys_sendmsg+0x61
kernel`amd64_syscall+0xa38
kernel`0xffffffff80f5891d
0 30776 sys_sendmsg:return
kernel`amd64_syscall+0xa38
kernel`0xffffffff80f5891d
> On 12 March 2019 23:37 Alan Somers <asomers@freebsd.org> wrote:
>
>
> Is he trying to send the kqueue file descriptor itself using sendmsg
> with SCM_RIGHTS? It sounds like kqueues cannot be sent over unix
> sockets; not every file type necessarily can. But if you want to know
> the nitty-gritty details, just run this:
> dtrace -i 'fbt:::return /arg1 == 45/ {stack();}' -c "my_program
> my_options" and that will usually tell you the exact function that set
> the error.
>
> If the output is too large, then you can filter it by writing a D
> program like this:
>
> #sendmsg.d
> fbt:kernel:sys_sendmsg:entry
> {
> this->trigger = 1;
> }
> fbt:::return
> / this->trigger == 1 && arg1 == 45 /
> {
> stack();
> }
> fbt:kernel:sys_sendmsg:return
> {
> this->trigger = 0;
> }
>
> dtrace -s sendmsg.d -c "my_program my_options"
>
> Hope that helps.
> -Alan
>
> On Tue, Mar 12, 2019 at 3:22 PM Larry Rosenman <ler@lerctr.org> wrote:
> >
> > I'm working with Aki Tuomi of Dovecot and he asks:
> >
> > I tried to ask if you could ask from some Kernel hacker why I cannot
> > send kqueue() fd over unix socket, I get "Operation not supported".
> >
> > Can anyone help me?
> >
> >
> >
> > --
> > Larry Rosenman http://www.lerctr.org/~ler
> > Phone: +1 214-642-9640 E-Mail: ler@lerctr.org
> > US Mail: 5708 Sabbia Dr, Round Rock, TX 78665-2106
> > _______________________________________________
> > freebsd-current@freebsd.org mailing list
> > https://lists.freebsd.org/mailman/listinfo/freebsd-current
> > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org"
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?306073586.2112.1552427555424>