Created attachment 1698083 [details]
ABRT report of a pminfo crash

Description of problem:
This is something I can not reliably reproduce, however from time to time pminfo crashes (SIGSEGV) dumping a core file. Typically this happens during run of test-case #688 of the pcp-testsuite.

Version-Release number of selected component (if applicable):
pcp-5.1.1-1.el8 and pcp-5.1.1-2.el8

How reproducible:
Intermittently

Steps to Reproduce:
1. Install pcp-testsuite
# yum install - pcp-testsuite
2. Run testcase #688
# cd /var/lib/pcp/testsuite && ./check 688

Actual results:
Sometimes the test-case #688 fails with an output similar to this:

> ./688: line 57: 836475 Segmentation fault      (core dumped) pminfo -d -Dderive,appl0 qa > $tmp.out 2>&1
94,136c95
< expr node <addr-24> type=FILTERINST left=<addr-25> right=<addr-26> save_last=0
< expr node <addr-25> type=PATTERN pattern: \[1\]100/ type: regex used=0
< expr node <addr-26> type=NAME left=(nil) right=(nil) save_last=0 [sample.bin] master=1
< __dmgetpmid: metric "qa.a" -> PMID 511.0.3
< __dmbind: bind metric[2] qa.a
< __dmtraverse: name="qa" added "qa.a"
< __dmgetpmid: metric "qa.b" -> PMID 511.0.4
< __dmbind: bind metric[3] qa.b
< __dmtraverse: name="qa" added "qa.b"
< __dmgetpmid: metric "qa.c" -> PMID 511.0.5
< __dmbind: bind metric[4] qa.c
< __dmtraverse: name="qa" added "qa.c"
< __dmgetpmid: metric "qa.d" -> PMID 511.0.6
< __dmbind: bind metric[5] qa.d
< __dmtraverse: name="qa" added "qa.d"
< __dmgetpmid: metric "qa.e" -> PMID 511.0.7
< __dmbind: bind metric[6] qa.e
< __dmtraverse: name="qa" added "qa.e"
< __dmgetpmid: metric "qa.a" -> PMID 511.0.3
< __dmgetpmid: metric "qa.b" -> PMID 511.0.4
< __dmgetpmid: metric "qa.c" -> PMID 511.0.5
< __dmgetpmid: metric "qa.d" -> PMID 511.0.6
< __dmgetpmid: metric "qa.e" -> PMID 511.0.7
< 
< qa.a
<     Data Type: 32-bit int  InDom: 29.2 0x7400002
<     Semantics: instant  Units: none
< 
< qa.b
<     Data Type: 32-bit int  InDom: 29.2 0x7400002
<     Semantics: instant  Units: none
< 
< qa.c
<     Data Type: 32-bit int  InDom: 29.2 0x7400002
<     Semantics: instant  Units: none
< 
< qa.d
<     Data Type: 32-bit int  InDom: 29.2 0x7400002
<     Semantics: instant  Units: none
< 
< qa.e
<     Data Type: 32-bit int  InDom: 29.2 0x7400002
<     Semantics: instant  Units: none
---
> expr node <addr-24> type=FILTERINST left=0xaaaac2ffc830 right=0xaaaac2ffcbf0 save_last=0

Expected results:
pminfo does not crash and test-case #688 succeeds

Additional info:
There is no reliable reproducer, however I am attaching an ABRT report from a crash, on aarch64 architecture, showing the code where the crash happens.