[Samba] Strange crashes and disconnection from PDC?

[Nir Soffer]

Cc:'d to samba-technical

( Background - I'm trying to see how I can get smbd to dump core,
 with a user supplied option to allow tell it where to dump it, I'm
 poring over the related code) 
 
> A 'corefile directory' option might be nice - but we will have to be
> careful.  Look into smb_panic() and exit_server() for somewhere to
> start.

Err. Okay. Can anyone explain me what's up here? From server.c

#if DUMP_CORE
/*******************************************************************
 Prepare to dump a core file - carefully !
********************************************************************/

static BOOL dump_core(void)
{
        char *p;
        pstring dname;
        pstrcpy(dname,lp_logfile());
        if ((p=strrchr(dname,'/'))) *p=0;
        pstrcat(dname,"/corefiles");
        mkdir(dname,0700);
        sys_chown(dname,getuid(),getgid());
        chmod(dname,0700);
        if (chdir(dname)) return(False);
        umask(~(0700));

dump_core is already there, DUMP_CORE is set to 1 (it looks like this
is the default one shipped, btw), yet nothing bloody happens.

The above snippet appears to create a corefiles directory above the log
dir, (which is, I assume, what you want to change using the core
directory
option), but it doesn't create it anywhere I can see after killing a
process with
sig11. What am I missing here?

Also - from what I see, the execution flow of a panic is something like:

exit_servers is set is a fault handler, however in fault_setup (fault.c)
a
SIGSEGV handler is set to sig_fault which calls fault_report which
calls smb_panic which calls abort().

When the heck is exit_servers called, then? And what function does
dump_core perform if there's no one to call it?

I'm probably missing something fundamental here, enlightment will
be appreciated.
  

Thanks,
Nir.


--
Nir Soffer -=- Software Engineer, Exanet Inc. -=-
"Father, why are all the children weeping? / They are merely crying son
 O, are they merely crying, father? / Yes, true weeping is yet to come"
        -- Nick Cave and the Bad Seeds, The Weeping Song>