Fix buffer underflow with HitPattern::getMuonStation()

[watson-ij]

PR description:

Fix underflow caused by GEM station 0 not being taken into account in HitPattern::getMuonStation()

Reported in issue #35283.

PR validation:

Trivial fix, I grepped through the file to see if there are other places that a similar thing could happen (similar constructions seem only to occur in the DT stations), but couldn't see any immediately. If there's a recipe to run the ASAN that I could try to check further, please let me know.

if this PR is a backport please specify the original PR and why you need to backport that PR:

Before submitting your pull requests, make sure you followed this checklist:

• verify that the PR is really intended for the chosen branch
• verify that changes follow CMS Naming, Coding, And Style Rules
• verify that the PR passes the basic test procedure suggested in the CMSSW PR instructions

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-35288/25291

• This PR adds an extra 24KB to repository

[cmsbuild]

A new Pull Request was created by @watson-ij (Ian J. Watson) for master.

It involves the following packages:

• DataFormats/TrackReco (reconstruction)

@jpata, @cmsbuild, @slava77 can you please review it and eventually sign? Thanks.
@JanFSchulte, @rovere, @VinInn, @gpetruc, @mmusich, @mtosi this is something you requested to watch as well.
@perrotta, @dpiparo, @qliphy you are the release manager for this.

cms-bot commands are listed here

[slava77]

If there's a recipe to run the ASAN that I could try to check further, please let me know.

the issue was reported in CMSSW_12_1_ASAN_X_2021-09-13-2300 in workflows 34834.21 and 34834.9921
you should be able to cmsrel CMSSW_12_1_ASAN_X_2021-09-13-2300 and then runTheMatrix.py -l 34834.21

[watson-ij]

If there's a recipe to run the ASAN that I could try to check further, please let me know.

the issue was reported in CMSSW_12_1_ASAN_X_2021-09-13-2300 in workflows 34834.21 and 34834.9921
you should be able to cmsrel CMSSW_12_1_ASAN_X_2021-09-13-2300 and then runTheMatrix.py -l 34834.21

Thanks, Slava. Sorry, its late night here, I was looking through it too quick, I thought it was an option that one could turn on. I can check it locally tomorrow if necessary.

[slava77]

@cmsbuild please test

[cmsbuild]

+1

Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-eb5ed8/18632/summary.html
COMMIT: 673103f
CMSSW: CMSSW_12_1_X_2021-09-14-1100/slc7_amd64_gcc900
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week0/cms-sw/cmssw/35288/18632/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• No significant changes to the logs found
• Reco comparison results: 2 differences found in the comparisons
• DQMHistoTests: Total files compared: 39
• DQMHistoTests: Total histograms compared: 3000833
• DQMHistoTests: Total failures: 6
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3000805
• DQMHistoTests: Total skipped: 22
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 38 files compared)
• Checked 165 log files, 37 edm output root files, 39 DQM output files
• TriggerResults: no differences found

[slava77]

+reconstruction

for #35288 673103f

• code changes are in line with the PR description and the notes in AddressSanitizer: stack-buffer-underflow reco::HitPattern::muonStations #35283
• jenkins tests pass and comparisons with the baseline show no differences (the random memory read would be present only in phase-2 M9 and later workflows and the random value would have had to be in coincidence to change the behavior of the OI muon seeding to be visible downstream)

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next master IBs (tests are also fine). This pull request will now be reviewed by the release team before it's merged. @perrotta, @dpiparo, @qliphy (and backports should be raised in the release meeting by the corresponding L2)

[qliphy]

+1