Experimental Physics and
Industrial Control System

Michael Davidsaver via Core-talk <core-talk at aps.anl.gov> · Mon, 10 Aug 2020 07:52:30 -0700

On 8/10/20 7:43 AM, Zimoch Dirk (PSI) via Core-talk wrote:
> Program terminated with signal 11, Segmentation fault.
> #0 0x00000028 in ?? ()
> (gdb) bt
> #0 0x00000028 in ?? ()

This is consistent a bad virtual call (this==NULL).  However,
I don't think this could happen as the preceding 'new'
should throw an exception on error.  The PVA code makes
extensive use of exceptions, so building with eg. '-fno-exception'
is not supported.

The alternative I can think of is stack corruption in 'initialize()'.

If this is happening consistently, can you set a break point on
line 4758 and inspect the value of 'internal' before the call?

> #1 0x0fc6db90 in epics::pvAccess::createClientProvider (conf=...) at ../../src/remoteClient/clientContextImpl.cpp:4758
> #2 0x0fbe33a4 in epics::pvAccess::(anonymous namespace)::FunctionFactory::newInstance (this=<optimized out>, conf=<error reading variable: value has been optimized out>)
> at ../../src/factory/ChannelAccessFactory.cpp:118
> #3 0x0fbe4ac0 in epics::pvAccess::ChannelProviderRegistry::createProvider (this=<optimized out>, providerName=..., conf=...) at ../../src/factory/ChannelAccessFactory.cpp:57
> #4 0x0fbb91b4 in pvac::ClientProvider::ClientProvider (this=0x7ff43dc0, providerName=..., conf=...) at ../../src/client/client.cpp:270
> #5 0x0ff7dafc in (anonymous namespace)::initPVALink(._91) (state=<optimized out>) at ../pvalink.cpp:120
> #6 0x0f63d49c in initHookAnnounce (state=initHookAfterInitDatabase) at ../iocsh/initHooks.c:87
> #7 0x0f7efa80 in iocBuild_2 () at ../misc/iocInit.c:168
> #8 0x0f7efd68 in iocBuild () at ../misc/iocInit.c:205
> #9 0x0f7efde0 in iocInit () at ../misc/iocInit.c:110
> #10 0x0f7f0330 in iocInitCallFunc (args=<error reading variable: value has been optimized out>) at ../misc/miscIocRegister.c:25
> #11 0x0f63c834 in iocshBody (pathname=0x14 <Address 0x14 out of bounds>, commandLine=0x0, macros=0x0) at ../iocsh/iocsh.cpp:937
> #12 0x0f63ca18 in iocsh (pathname=<error reading variable: value has been optimized out>) at ../iocsh/iocsh.cpp:1013
> #13 0x10004c8c in main (argc=1, argv=0x7ff44250) at ../softMain.cpp:236
> 
> In modules/pvAccess/src/remoteClient/clientContextImpl.cpp line 4758 'internal' seems to be NULL:
>     internal->initialize();
> 
> This only happens with one of my embedded Linux architectures using ELDK 4.2. It uses gcc 4.2.2.
> 

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System