Re: segmentation fault in ca_task_initialize running in Linux

[Margaret Votava <votava@fnal.gov>]

Hi Jeff,

I apologize profusely for a less than timely reply. My interrupt queue
was deep and we were running with a workaround.

I tried the patch today and it didn't help. See trace below. I promise
to be faster in the future.

Thanks a lot,
Margaret



Starting program: 
/home/votava/smtf/doocs/clients/rpc_util/Linux/bin/rpc_util
Breakpoint 2 at 0xdca2b5: file ../ca_client_context.cpp, line 736.
Breakpoint 3 at 0xdc7421: file ../ca_client_context.cpp, line 55.
[Thread debugging using libthread_db enabled]
[New Thread -1208031008 (LWP 27375)]
[Switching to Thread -1208031008 (LWP 27375)]

Breakpoint 3, cacOnceFunc () at ../ca_client_context.cpp:55
55          caClientCallbackThreadId = epicsThreadPrivateCreate ();
(gdb) n
56          assert ( caClientCallbackThreadId );
(gdb) n
55          caClientCallbackThreadId = epicsThreadPrivateCreate ();
(gdb) n
56          assert ( caClientCallbackThreadId );
(gdb) n
57          ca_client_context::pDefaultServiceInstallMutex = new epicsMutex;
(gdb) n
58          epicsAtExit ( cacExitHandler,0 );
(gdb) n
57          ca_client_context::pDefaultServiceInstallMutex = new epicsMutex;
(gdb) c
Continuing.

Program received signal SIGSEGV, Segmentation fault.
epicsMutex::lock (this=0x0) at ../../../src/libCom/osi/epicsMutex.cpp:118
118             epicsMutexOsdLock(pmutexNode->id);
(gdb) where
#0  epicsMutex::lock (this=0x0) at 
../../../src/libCom/osi/epicsMutex.cpp:118
#1  0x00df37d1 in ipAddrToAsciiEngine::allocate () at 
../../../src/libCom/cxxTemplates/epicsGuard.h:68
#2  0x00dd02ef in cac (this=0x99e28a8, mutualExclusionIn=@0x0, 
callbackControlIn=@0x99e26e4, notifyIn=@0x0) at ../cac.cpp:144
#3  0x00dc943d in ca_client_context (this=0x99e2670, 
enablePreemptiveCallback=false) at ../../../include/epicsMemory.h:110
#4  0x00dc638a in ca_context_create 
(premptiveCallbackSelect=ca_disable_preemptive_callback) at 
../access.cpp:204
#5  0x00dc63d5 in ca_task_initialize () at ../access.cpp:180
#6  0x00db8e19 in epics_init () at 
/home/votava/smtf/doocs/libs/clientlib/source/clientlib/eq_svr.cc:1928
#7  0x00dc08d9 in EqCall (this=0x99e2490) at 
/home/votava/smtf/doocs/libs/clientlib/source/clientlib/eq_client.cc:369
#8  0x00ff8057 in __static_initialization_and_destruction_0 
(__initialize_p=1, __priority=65535)
   at 
/home/votava/smtf/doocs/libs/dddlib/source/dddlib/panels/device_attr_stubs.cc:26
#9  0x00ff8137 in global constructors keyed to ea () at 
/home/votava/smtf/doocs/libs/dddlib/source/dddlib/panels/device_attr_stubs.cc:400
#10 0x01029329 in __do_global_ctors_aux () from 
/home/votava/smtf/doocs/ups/../ups/../libs/dddlib/ups/../ups/../Linux/lib/libddd.so.2.2.6
#11 0x00f37d7d in _init () from 
/home/votava/smtf/doocs/ups/../ups/../libs/dddlib/ups/../ups/../Linux/lib/libddd.so.2.2.6
#12 0x00271318 in _dl_init_internal () from /lib/ld-linux.so.2
#13 0x002657ff in _dl_start_user () from /lib/ld-linux.so.2
(gdb)


Jeff Hill wrote:

> I subsequently installed this patch to reduce the scope of the previously
> mentioned patch.
>
> Saved settings for D:usershillR3.14.dll_hell_fixepicsbase successfully...
> cvs diff -u -wb -i -- ca_client_context.cpp (in directory
> D:usershillR3.14.dll_hell_fixepicsbasesrcca)
> Index: ca_client_context.cpp
> ===================================================================
> RCS file:
> /net/phoebus/epicsmgr/cvsroot/epics/base/src/ca/ca_client_context.cpp,v
> retrieving revision 1.9.2.19
> diff -c -u -w -b -i -r1.9.2.19 ca_client_context.cpp
> cvs diff: conflicting specifications of output style
> --- ca_client_context.cpp 17 Feb 2006 22:31:42 -0000 1.9.2.19
> +++ ca_client_context.cpp 17 Feb 2006 22:38:36 -0000
> @@ -78,7 +78,7 @@
> }
>
> epicsThreadOnce ( & cacOnce, cacOnceFunc, 0 );
> -
> + {
> epicsGuard < epicsMutex > guard (
> *ca_client_context::pDefaultServiceInstallMutex );
> if ( ca_client_context::pDefaultService ) {
> this->pServiceContext.reset (
> @@ -88,6 +88,7 @@
> else {
> this->pServiceContext.reset ( new cac ( this->mutex, this->cbMutex, *this )
> );
> }
> + }
>
> this->sock = epicsSocketCreate ( AF_INET, SOCK_DGRAM, IPPROTO_UDP );
> if ( this->sock == INVALID_SOCKET ) {
>
> ***** CVS exited normally with code 1 *****
>
>
>  
>
> > -----Original Message-----
> > From: Margaret Votava [mailto:votava@fnal.gov]
> > Sent: Friday, February 17, 2006 10:36 AM
> > To: tech-talk@aps.anl.gov
> > Cc: doocs@doocs.desy.de; ron@fnal.gov; piccoli@fnal.ov
> > Subject: segmentation fault in ca_task_initialize running in Linux
> >
> >
> > Dear all,
> >
> > We are trying to understand a problem with a DESY/DOOCS utility.
> > It generates a segmentation fault within ca_task_initialize (stack trace
> > below). The
> >
> > epicsMutex ca_client_context::defaultServiceInstallMutex;
> >
> > constructor is not being called in all OS platform/Compiler
> > combinations.
> >
> > In particular, a failing combination is
> > Linux 2.6.8-22.0.2/gcc v3.4.3 (red hat)
> > Linux 2.6.1/gcc v3.2.3 (red hat)
> >
> > but works in Solaris with Solaris compiler.
> >
> > We believe that this is a linker problem.
> >
> > Has anyone seen before or have any clues of how to fix?
> >
> > Thank you kindly,
> > Margaret
> >
> > ### epics code ###
> >
> > (gdb) where
> > #0  epicsMutexLock (pmutexNode=0x0)
> >    at ../../../src/libCom/osi/epicsMutex.cpp:118
> > #1  0x006add15 in epicsMutex::lock (this=0x0)
> >    at ../../../src/libCom/osi/epicsMutex.cpp:211
> > #2  0x00ca19cb in ca_client_context (this=0x8d8ce08,
> >    enablePreemptiveCallback=false) at ../../../include/epicsGuard.h:68
> > #3  0x00c88305 in ca_context_create (
> >    premptiveCallbackSelect=ca_disable_preemptive_callback)
> >    at ../access.cpp:204
> > #4  0x00c8835e in ca_task_initialize () at ../access.cpp:180
> >
> > ### doocs code ####
> >
> > #5  0x00a3e9f5 in epics_init ()
> >    at
> > /home/votava/smtf/doocs/libs/clientlib/source/clientlib/eq_svr.cc:1928
> > #6  0x00a464b5 in EqCall (this=0x8d8cc88)
> >    at
> > /home/votava/smtf/doocs/libs/clientlib/source/clientlib/eq_client.cc:369
> > #7  0x00e05837 in __static_initialization_and_destruction_0
> > (__initialize_p=1,
> >    __priority=65535)
> >    at
> > /home/votava/smtf/doocs/libs/dddlib/source/dddlib/panels/device_attr_stubs
> > .cc:26
> > #8  0x00e05917 in global constructors keyed to ea ()
> >    at
> > /home/votava/smtf/doocs/libs/dddlib/source/dddlib/panels/device_attr_stubs
> > .cc:400
> > #9  0x00e36819 in __do_global_ctors_aux ()
> >   from
> > /home/votava/smtf/doocs/ups/../ups/../libs/dddlib/ups/../ups/../Linux/lib/
> > libddd.so.2.2.5
> > #10 0x00d45add in _init ()
> >   from
> > /home/votava/smtf/doocs/ups/../ups/../libs/dddlib/ups/../ups/../Linux/lib/
> > libddd.so.2.2.5
> > #11 0x00271318 in _dl_init_internal () from /lib/ld-linux.so.2
> > #12 0x002657ff in _dl_start_user () from /lib/ld-linux.so.2
> >    
>
>
>