On Fri, Oct 15, 2021 at 07:47:22PM +0200, Mischa wrote:
>
>
> On 2021-10-15 19:42, Otto Moerbeek wrote:
> > On Fri, Oct 15, 2021 at 07:16:55PM +0200, Mischa wrote:
> >
> > > On 2021-10-15 18:27, Otto Moerbeek wrote:
> > > >
> > > > The actual problem (SIGSEGV) happens in the child processes: ktrace the
> > > > children as well: ktrace -di ...
> > > >
> > > > -Otto
> > >
> > > Thanx Otto.
> > > Below is the the kdump with ktrace -di
> > > It's quite a lot of data but I didn't want to remove something that
> > > could
> > > potentially be useful.
> > >
> > > Mischa
> > >
> >
> > The pattern below happens multiple times:
> >
> > A recvfrom of 101 bytes and after that a SIGSEGV.
> >
> > Now we do not know for sure if those two lines are related.
> >
> > I suspect that it is no coincidence that the 101 is one larger than
> > 100...
> >
> > No other clue yet.
>
> Anything else I can collect.
You might want to compile and install nsd wit debug symbols info:
cd /usr/src/usr.sbin/nsd
make -f Makefile.bsd-wrapper obj
make -f Makefile.bsd-wrapper clean
DEBUG=-g make -f Makefile.bsd-wrapper
make -f Makefile.bsd-wrapper install
Then: collect a gdb trace from a running process: install gdb from ports,
run
egdb --pid=pidofnsdchild /usr/sbin/nsd
and wait for the crash.
But I'm mostly unfamiliar with the nsd code and what has been changed
recently. I's say make sure sthen@ and florian@ see this: move to
bugs@ as I do not know if they read misc@.
-Otto
>
> Mischa
>
>
> >
> > -Otto
> >
> > > 91127 nsd CALL
> > > recvfrom(7,0xb2ac85b8000,0x20109,0,0xb2acfa96018,0xb27e485a968)
> > > 91127 nsd GIO fd 7 read 101 bytes
> > > "By\0\0\0\^A\0\0\0\0\0\^A\^A6\^A0\^A1\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A0\^A1\^A0\^A0\^A0\^A4\^A0\^A0\^A1\^A0\^A0\^A0\^A6\^A3\^A0\^Aa\^A2\^Cip6\^Darpa\0\0\f\0\
> > > \^A\0\0)\^E\M-,\0\0\M^@\0\0\0"
> > > 91127 nsd STRU struct sockaddr { AF_INET,
> > > 141.101.75.185:10029 }
> > > 91127 nsd RET recvfrom 101/0x65
> > > 91127 nsd PSIG SIGSEGV SIG_DFL code SEGV_MAPERR<1> addr=0x10
> > > trapno=6
> > > 36104 nsd STRU struct pollfd [2] { fd=16, events=0x1<POLLIN>,
> > > revents=0<> } { fd=15, events=0x1<POLLIN>, revents=0<> }
> > > 36104 nsd PSIG SIGCHLD caught handler=0xb27e47fa340 mask=0<>
