fix(libsinsp): cache invalidation and potential use-after-free in state table api for plugins and sinsp

[jasondellaluce]

What type of PR is this?

/kind bug

/kind cleanup

Any specific area of the project related to this PR?

/area libsinsp

Does this PR require a change in the driver versions?

What this PR does / why we need it:

This is a follow up for the issues fixed in #2257. I discovered that due to how thread management works, there may be corner cases where the last cached thread ref or the cached fd tables pointer might become stale, thus potentially causing use after free issues.

Which issue(s) this PR fixes:

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

NONE

[github-actions]

Perf diff from master - unit tests

     0.01%    +18.09%  [.] sinsp_threadinfo::get_main_thread
     0.03%     +8.99%  [.] sinsp_thread_manager::create_thread_dependencies
     0.82%     +7.74%  [.] std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release
    12.93%     -5.19%  [.] sinsp::next
    10.02%     -3.19%  [.] sinsp_parser::reset
     7.48%     -2.34%  [.] sinsp_evt::get_type
     3.02%     -1.39%  [.] sinsp_thread_manager::get_thread_ref
     5.23%     -1.34%  [.] next_event_from_file
     3.64%     -1.23%  [.] gzfile_read
     3.52%     -0.97%  [.] sinsp_evt::load_params

Heap diff from master - unit tests

peak heap memory consumption: 0B
peak RSS (including heaptrack overhead): 0B
total memory leaked: 0B

Heap diff from master - scap file

peak heap memory consumption: 0B
peak RSS (including heaptrack overhead): 0B
total memory leaked: 0B

Benchmarks diff from master

Comparing gbench_data.json to /root/actions-runner/_work/libs/libs/build/gbench_data.json
Benchmark                                                         Time             CPU      Time Old      Time New       CPU Old       CPU New
----------------------------------------------------------------------------------------------------------------------------------------------
BM_sinsp_split_mean                                            +0.0351         +0.0350           144           149           144           149
BM_sinsp_split_median                                          +0.0358         +0.0358           144           149           144           149
BM_sinsp_split_stddev                                          +0.4513         +0.4532             1             1             1             1
BM_sinsp_split_cv                                              +0.4022         +0.4040             0             0             0             0
BM_sinsp_concatenate_paths_relative_path_mean                  +0.0045         +0.0045            57            57            57            57
BM_sinsp_concatenate_paths_relative_path_median                +0.0018         +0.0018            57            57            57            57
BM_sinsp_concatenate_paths_relative_path_stddev                +0.2679         +0.2676             0             0             0             0
BM_sinsp_concatenate_paths_relative_path_cv                    +0.2622         +0.2619             0             0             0             0
BM_sinsp_concatenate_paths_empty_path_mean                     -0.0029         -0.0029            25            25            25            25
BM_sinsp_concatenate_paths_empty_path_median                   -0.0071         -0.0070            25            25            25            25
BM_sinsp_concatenate_paths_empty_path_stddev                   +0.6453         +0.6520             0             0             0             0
BM_sinsp_concatenate_paths_empty_path_cv                       +0.6501         +0.6568             0             0             0             0
BM_sinsp_concatenate_paths_absolute_path_mean                  -0.0443         -0.0442            57            54            57            54
BM_sinsp_concatenate_paths_absolute_path_median                -0.0648         -0.0647            57            53            57            53
BM_sinsp_concatenate_paths_absolute_path_stddev                +2.9832         +2.9847             0             2             0             2
BM_sinsp_concatenate_paths_absolute_path_cv                    +3.1676         +3.1688             0             0             0             0
BM_sinsp_split_container_image_mean                            +0.0013         +0.0014           392           392           392           392
BM_sinsp_split_container_image_median                          -0.0002         -0.0001           392           392           392           392
BM_sinsp_split_container_image_stddev                          -0.3573         -0.3569             3             2             3             2
BM_sinsp_split_container_image_cv                              -0.3581         -0.3578             0             0             0             0

[codecov]

Codecov Report

Attention: Patch coverage is 82.85714% with 6 lines in your changes missing coverage. Please review.

Project coverage is 75.33%. Comparing base (5a0302c) to head (477f327).
Report is 13 commits behind head on master.

Files with missing lines	Patch %	Lines
userspace/libsinsp/state/table.cpp	33.33%	6 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #2266      +/-   ##
==========================================
- Coverage   75.34%   75.33%   -0.01%     
==========================================
  Files         279      279              
  Lines       34369    34394      +25     
  Branches     5874     5884      +10     
==========================================
+ Hits        25894    25910      +16     
- Misses       8475     8484       +9     

Flag	Coverage Δ
libsinsp	75.33% <82.85%> (-0.01%)	⬇️

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[FedeDP]

/milestone 0.21.0

[FedeDP]

/approve

[poiana]

LGTM label has been added.

Git tree hash: 1b899bae799e864197801f5898492291dec5848f

[FedeDP]

/approve

[poiana]

LGTM label has been added.

Git tree hash: 75c2a0eaf5d331c2e9057df6df080108e10b1de2

[poiana]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: FedeDP, jasondellaluce

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