[UBSAN][Math] Suppress signed-integer-overflow for approx_exp

[smuzaffar]

This PR suggests to suppress [a] UBSAN runtime errors. According to #11753 (comment) this overflow should be considered as feature. This change will suppress the signed-integer-overflow runtime error coming from unsafe_expf_impl() function.

Note that CMS_UNDEFINED_SANITIZER is cpp macro which is only set when we build UBSAN IBs.

FYI @VinInn, let me know if you have any better way to fix/suppress this error

Fixes #46396

[a]

136.821/step3:DataFormats/Math/interface/approx_exp.h:154:5: runtime error: signed integer overflow: -2147483648 - 1 cannot be represented in type 'int'
136.821/step3:DataFormats/Math/interface/approx_exp.h:162:32: runtime error: signed integer overflow: 2147483647 + 127 cannot be represented in type 'int'

[cmsbuild]

cms-bot internal usage

[cmsbuild]

-code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-46417/42271

Code check has found code style and quality issues which could be resolved by applying following patch(s)

• code-format:
  https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-46417/42271/code-format.patch
  e.g. curl -k https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-46417/42271/code-format.patch | patch -p1
  You can also run scram build code-format to apply code format directly

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-46417/42272

[smuzaffar]

please test

[cmsbuild]

A new Pull Request was created by @smuzaffar for master.

It involves the following packages:

• DataFormats/Math (reconstruction)

@jfernan2, @mandrenguyen can you please review it and eventually sign? Thanks.
@fabiocos, @felicepantaleo, @makortel, @missirol, @mmusich, @rovere this is something you requested to watch as well.
@antoniovilela, @mandrenguyen, @rappoccio, @sextonkennedy you are the release manager for this.

cms-bot commands are listed here

[VinInn]

just tell USBAN to not worry: we know better

[smuzaffar]

just tell USBAN to not worry: we know better

thanks @VinInn . I think this is what this PR is proposing (ignore the signed integer overflow for unsafe_expf_impl() function for UBSAN build)

[smuzaffar]

I will do the same for UBSAN vdt runtime error

vdt/sincos.h:214:6: runtime error: signed integer overflow: -2147483648 - 2 cannot be represented in type 'int'

[VinInn]

said that: in principle
x = std::min(std::max(x, zero_threshold_ftz), inf_threshold);
should avoid the overflow....

[smuzaffar]

Or we change https://github.com/cms-sw/cmssw/blob/master/DataFormats/Math/interface/approx_exp.h#L168

-#ifndef NO_APPROX_MATH
+#if !defined(NO_APPROX_MATH) && !defined(CMS_UNDEFINED_SANITIZER)

so that for ubsan we use std::exp(x);

[smuzaffar]

ah forget my #46417 (comment) , that will not work. UBSAN will still see the unsafe_expf_impl

[smuzaffar]

test parameters:

• workflow = 136.821

[smuzaffar]

please test for CMSSW_14_2_UBSAN_X

[cmsbuild]

+1

Size: This PR adds an extra 20KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-1e4dee/42254/summary.html
COMMIT: d85088f
CMSSW: CMSSW_14_2_X_2024-10-16-2300/el8_amd64_gcc12
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/46417/42254/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: 4 differences found in the comparisons
• DQMHistoTests: Total files compared: 44
• DQMHistoTests: Total histograms compared: 3335129
• DQMHistoTests: Total failures: 455
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3334654
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 43 files compared)
• Checked 193 log files, 163 edm output root files, 44 DQM output files
• TriggerResults: no differences found

[makortel]

Could we add comments explaining why this is done? (so that a curious reader would not have to do GitHub archaeology)

[cmsbuild]

+code-checks

Logs: https://cmssdt.cern.ch/SDT/code-checks/cms-sw-PR-46417/42287

[cmsbuild]

Pull request #46417 was updated. @cmsbuild, @jfernan2, @mandrenguyen can you please check and sign again.

[smuzaffar]

please test

[cmsbuild]

+1

Size: This PR adds an extra 24KB to repository
Summary: https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-1e4dee/42283/summary.html
COMMIT: d510b7b
CMSSW: CMSSW_14_2_X_2024-10-17-2300/el8_amd64_gcc12
User test area: For local testing, you can use /cvmfs/cms-ci.cern.ch/week1/cms-sw/cmssw/46417/42283/install.sh to create a dev area with all the needed externals and cmssw changes.

Comparison Summary

Summary:

• You potentially added 2 lines to the logs
• Reco comparison results: 2 differences found in the comparisons
• DQMHistoTests: Total files compared: 47
• DQMHistoTests: Total histograms compared: 3604451
• DQMHistoTests: Total failures: 415
• DQMHistoTests: Total nulls: 0
• DQMHistoTests: Total successes: 3604016
• DQMHistoTests: Total skipped: 20
• DQMHistoTests: Total Missing objects: 0
• DQMHistoSizes: Histogram memory added: 0.0 KiB( 46 files compared)
• Checked 205 log files, 174 edm output root files, 47 DQM output files
• TriggerResults: no differences found

[jfernan2]

+1

[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. @antoniovilela, @sextonkennedy, @mandrenguyen, @rappoccio (and backports should be raised in the release meeting by the corresponding L2)

[mandrenguyen]

+1