Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Mon, 1 Oct 2018 09:10:12 +0200

Hello Abdalla,

In the stack trace you can see a problem with a NULL pointer access in

your record support code. No StreamDevice involved here at all.

Are you sure you load the correct dbd file? Loading a dbd file of a

wrong EPICS base version is a common cause for crashes.

I will try your code. Maybe I find something....

Dirk

On 30.09.2018 14:41, Abdalla  Ahmad wrote:

Hi

One of our IOC servers currently has the following setup:

OS: SL 6.4 32-bit

EPICS: 3.15.5 (previously 3.14.12.3)

synApps built from assemble_synApps script (previously 5.6)

Stream device R2-7-7a (Previously 2-5-1)

This IOC has some records that use a custom record called "mbbi2" which

was created here at SESAME by an engineer used to work here. The purpose

of this record is to provide alarm severity for each bit of the standard

mbbiDirect, otherwise they are the same.

The problem is integrating this record with the stream device driver.

What we found after searching the synApps 5.6 setup:

1.Adding MBBI2 definition to the stream device configure/RELEASE.

2.Including mbbi2.dbd and mbbi library in streamApp/Makefile.

3.Having mbbi2Record.h and devmbbiStream.c sources in the StreamDevice/src

4.Adding mbbi2 to RECORDS in StreamDevice/src/CONFIG_STREAM

That's all under base 3.14.12.3, we are not sure if something else is

missing under 3.15.5 setup. With all these steps, the new stream device

driver compiles with mbbi2 definitions (dbd file, ldd command), but when

running the IOC it immediately crashes with segmentation fault. I

enabled core dumps, loaded the core dump into gdb, backtrace it and I

got this

Core was generated by `./bin/linux-x86/ioc iocBoot/ioc/st.cmd'.

Program terminated with signal 11, Segmentation fault.

#0  cvt_st_us (from=0xb <Address 0xb out of bounds>, to=0x87f9354,

paddr=0x0) at ../../../src/ioc/db/dbFastLinkConv.c:161

161     if (*from == 0) {

Missing separate debuginfos, use: debuginfo-install

glibc-2.12-1.107.el6_4.5.i686 libgcc-4.4.7-3.el6.i686

libstdc++-4.4.7-3.el6.i686 ncurses-libs-5.7-3.20090208.el6.i686

net-snmp-libs-5.5-44.el6_4.4.i686 openssl-1.0.0-27.el6_4.2.i686

pcre-7.8-6.el6.i686 readline-6.0-4.el6.i686 zlib-1.2.3-29.el6.i686

(gdb) backtrace

#0  cvt_st_us (from=0xb <Address 0xb out of bounds>, to=0x87f9354,

paddr=0x0) at ../../../src/ioc/db/dbFastLinkConv.c:161

#1  0x00848d0f in dbConstLoadLink (plink=0x87f9338, dbrType=4,

pbuffer=0x87f9354) at ../../../src/ioc/db/dbLink.c:108

#2  dbLoadLink (plink=0x87f9338, dbrType=4, pbuffer=0x87f9354) at

../../../src/ioc/db/dbLink.c:475

#3  0x008556fc in recGblInitConstantLink (plink=0x87f9338, dbftype=4,

pdest=0x87f9354) at ../../../src/ioc/db/recGbl.c:167

#4  0x006c14f8 in init_record (prec=0x87f91c0, pass=1) at

../mbbi2Record.c:153

#5  0x008719c7 in doInitRecord1 () at ../../../src/ioc/misc/iocInit.c:543

#6  iterateRecords () at ../../../src/ioc/misc/iocInit.c:472

#7  initDatabase () at ../../../src/ioc/misc/iocInit.c:551

#8  iocBuild_2 () at ../../../src/ioc/misc/iocInit.c:148

#9  0x00871c0a in iocBuild () at ../../../src/ioc/misc/iocInit.c:187

#10 0x00871c77 in iocInit () at ../../../src/ioc/misc/iocInit.c:99

#11 0x008723f7 in iocInitCallFunc (args=0x878ba80) at

../../../src/ioc/misc/miscIocRegister.c:25

#12 0x00a11271 in iocshBody (pathname=<value optimized out>,

commandLine=0x0, macros=0x0) at ../../../src/libCom/iocsh/iocsh.cpp:815

#13 0x00a11a25 in iocsh (pathname=0xbfe125f0 "iocBoot/ioc/st.cmd") at

../../../src/libCom/iocsh/iocsh.cpp:883

#14 0x0804c97d in main (argc=2, argv=0xbfe10514) at ../iocMain.cpp:17

The IOC was complaining about DTYP and BFST fields which it cannot set

their values, we looked up the mbbi2.dbd and found out deprecated values

for the promotgroup. We are not sure if this is the problem or not but

we changed all promotegroup to the new values found in base 3.15.5 app

developer guide, the IOC accepted the DTYP field but still unable to set

. Still facing the same segmentation fault with the same backtrace.

Here is an example mbbi2 record:

record(mbbi2, "$(SYSTEM):getStatusWord")

{

     field(DESC, "Reads status word")

     field(SCAN, "2 second")

     field(DTYP, "stream")

     field(INP, "@work-microwave-ssx.proto getStatusWord $(CONTROLLER)")

     field(VAL, "0")

     field(PINI, "YES")

     field(B0ST, "Standby mode")        field(B0ZSV, "NO_ALARM")

field(B0OSV, "NO_ALARM")

     field(B1ST, "PLO PLL")             field(B1ZSV, "NO_ALARM")

field(B1OSV, "MINOR")

     field(B2ST, "Reference PLL")       field(B2ZSV, "NO_ALARM")

field(B2OSV, "MAJOR")

     field(B3ST, "Reference PLL")       field(B3ZSV, "NO_ALARM")

field(B3OSV, "MINOR")

     field(B4ST, "Level Control")       field(B4ZSV, "NO_ALARM")

field(B4OSV, "NO_ALARM")

     field(B5ST, "MW")                  field(B5ZSV, "NO_ALARM")

field(B5OSV, "MINOR")

     field(B6ST, "OCXO/TCXO")           field(B6ZSV, "NO_ALARM")

field(B6OSV, "NO_ALARM")

     field(B7ST, "RF OFF")              field(B7ZSV, "NO_ALARM")

field(B7OSV, "NO_ALARM")

     field(B8ST, "Oven status (OCXO)")  field(B8ZSV, "NO_ALARM")

field(B8OSV, "NO_ALARM")

     field(B9ST, "Main synthesizer")    field(B9ZSV, "NO_ALARM")

field(B9OSV, "MAJOR")

     field(BAST, "VHF synthesizer")     field(BAZSV, "NO_ALARM")

field(BAOSV, "MAJOR")

     field(BBST, "Fine synthesizer")    field(BBZSV, "NO_ALARM")

field(BBOSV, "MAJOR")

     field(BCST, "DBLR-Status (SSX-3)") field(BCZSV, "NO_ALARM")

field(BCOSV, "MAJOR")

     field(BDST, "Summarized alarm")    field(BDZSV, "NO_ALARM")

field(BDOSV, "MAJOR")

     field(BEST, "Reference-PLL")       field(BEZSV, "NO_ALARM")

field(BEOSV, "MAJOR")

     field(BFST, "MW PLL")              field(BFZSV, "NO_ALARM")

field(BFOSV, "MAJOR")

}

Sorry for any misinformation, all our findings were the result of

comparing between the two EPICS bases and the two synApps collections.

Attached is the record's source code stream device interface files.

Best Regards,

Abdalla Ahmad

Control Engineer

SESAME

Allan, Jordan.

Tel: (+962-5) 3511348 , ext. 265

Fax: (+962-5) 3511423

Mob: (+962-7)88183296

www.sesame.org.jo <http://www.sesame.org.jo/>

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System