Fix attaching to multiple USDT probes using the same wildcard #2456
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jonas-kaufmann
requested review from
ajor,
viktormalik,
danobi,
fbs and
BurntBrunch
as code owners
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Hi, thanks for the PR!
I've couple of comments in the code, plus one general question: what will happen if we don't give a wildcard but still attach to a probe with multiple locations (usdt:./testprogs/usdt_multiple_locations:tracetest:testprobe)?
Also I'd prefer all the commits squashed into one since the changes (in the code and in the tests) are coupled together.
Attaching to multiple USDT probes with different number of locations by the same wildcard can produce the error 'code not generated for probe'. The reason is that a single AttachPoint has multiple matching probes in this case but we only store the USDT information for a single probe in AttachPoint. Later, the number of locations from the USDT information stored in AttachPoint is used to look up the generated code for every probe to attach to, which can differ between the USDT probes and cause the above mentioned error. Add test for attaching with single wildcard to multiple USDT probes with different number of locations USDT test multiple files: update expected number of attached probes Update CHANGELOG Fix attaching to multiple USDT probes using the same wildcard
In that case everything works as expected. An The issue I am fixing only arises when a single |
Right, thanks for confirmation! |
Hi,
this is my first pull request in a public repository. Let me know what I can improve :)
Short description of the issue:
Attaching to multiple USDT probes with different number of locations by the same wildcard can produce the error 'code not generated for probe'. The reason is that a single AttachPoint has multiple matching probes in this case but we only store the USDT information for a single probe in AttachPoint. Later, the number of locations from the USDT information stored in AttachPoint is used to look up the generated code for every probe to attach to, which can differ between the USDT probes and cause the above mentioned error.
Checklist
man/adoc/bpftrace.adocand if needed indocs/reference_guide.mdCHANGELOG.md