check device core dump

[Jan-Henrik Haukeland]

Martin, I just ran a test (as a non-root user) using the following
monitrc:

check device cdrom with path /dev/cdrom
   start "/bin/mount /dev/cdrom"
   stop  "/bin/umount /dev/cdrom"
   if space > 1000 MB then alert
   alert address@hidden

check device disk1 with path /
   alert address@hidden

Running monit: monit -Iv

Gives the following core dump:

  The service list contains the following entries:
  
  Device Name           = cdrom
  Group                = (not defined)
  Path                 = /dev/cdrom
  Monitoring mode      = active
  Start program        = /bin/mount /dev/cdrom
  Stop program         = /bin/umount /dev/cdrom
  
  Program received signal SIGSEGV, Segmentation fault.
  [Switching to Thread 1024 (LWP 14146)]
  0x42080c63 in strlen () from /lib/i686/libc.so.6
  (gdb) 

The problematic code is in util.c:659:


    } else if(dl->resource == RESOURCE_ID_SPACE) {

 =>   printf(" %-20s = if %s %ld %s then %s\n",
           "Space usage limit",
           operatornames[dl->operator],
           (dl->limit_absolute > -1)?dl->limit_absolute:dl->limit_percent,
           (dl->limit_absolute > -1)?"blocks":"%",
           actionnames[dl->action]);

    }

(gdb) p *dl
$2 = {resource = 11, operator = 0, limit_absolute = -2147483648, 
  limit_percent = -1, action = 1000, next = 0x0}


The core dump happens because actionnames[1000] points way out of the
actionnames array. The limit_absolute value looks rotten to. Can you
please take a look at it?

------------------------------------------------------------------------------

Also I think that using simply

check device disk1 with path /dev/hda5
   alert address@hidden

should lead to a call to DeviceInfo_Usage in validate.c:check_device,
because it's first after this call, when you try to read info from the
device you will now if the device was mounted or not, the other tests
in validate.c:check_device almost always will be true since they
simply test the /dev/device if it exist, which it usually will.

As the parser is now, this function will not be called, unless an
IF-THEN test was added to the entry.

BTW, I have changed the event to START if monit cannot read from the
device, so monit will call the entry's start method, and not UNMONITOR
as I wrongly added before.

-- 
Jan-Henrik Haukeland