[Nut-upsdev] newhidups with APC Smart-UPS 1500

[Peter Selinger]

Hi Jacob,

drats, that was a dumb mistake. Thanks for catching this. Your patch
does not quite fix the problem; the real problem is that I freed the
data structure when it sometimes hadn't been created. I just committed
a bugfix that hopefully fixes it (see below patch).

-- Peter

Schmier, Jacob wrote:
> 
> Peter,
> 
> When I test your fix (newhidups -DDD /dev/null) using a MGE Pulsar
> Evolution 2200, I get a segmentation fault.  I do not get this problem
> when running the 2.0.4 release.  There seems to be a 3-5 second delay
> between the "Waiting for notifications..." output and the segmentation
> fault.
> 
> By initializing the eventlist pointer to NULL in upsdrv_updateinfo, I
> was able to correct the problem.  So I believe the fix would be the
> following:
> 
> -HIDEvent *eventlist;
> +HIDEvent *eventlist = NULL;
> 
> 
> ~Jacob

Index: drivers/newhidups.c
===================================================================
--- drivers/newhidups.c (revision 551)
+++ drivers/newhidups.c (working copy)
@@ -558,9 +558,10 @@
                        for (p=eventlist; p!=NULL; p=p->next) 
                          {
                                /* Check if we are asked to stop (reactivity++) */
-                               if (exit_flag != 0)
+                               if (exit_flag != 0) {
+                                 HIDFreeEvents(eventlist);
                                  return;
-
+                               }
                                upsdebugx(3, "Object: %s = %ld", 
                                                  p->Path,
                                                  p->Value);
@@ -602,11 +603,11 @@
                                  }
                          }
                        dstate_dataok();
+                       HIDFreeEvents(eventlist);
                  }
                else {
                  retcode = evtCount; /* propagate error code */
                }
-               HIDFreeEvents(eventlist);
 
                /* Quick poll on main ups.status data */
                hid_ups_walk(HU_WALKMODE_QUICK_UPDATE);