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Go build IDs in ELF notes are stored as C strings with a trailing NUL terminator. The note header's valSize includes this terminator, so readBuildIDFromELF was returning build ID strings containing \x00. Consumers passing these through profile metadata (e.g. pprof mappings) end up with invalid cache paths during symbolization. Fixes parca-dev/parca-agent#3152 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
readBuildIDFromELFuses the note header'svalSizewhich includes this terminator, so the returned string contains\x00.Mapping.BuildID) end up with invalid cache paths during symbolization in Parca.strings.TrimRightthe NUL byte at the source inreadBuildIDFromELF.Fixes parca-dev/parca-agent#3152
Test plan
TestReadBuildID_GoNoteNulTrimmed— synthetic ELF with Go note containing trailing NUL, verifies it is strippedTestReadBuildID_GNUNoteUnchanged— synthetic ELF with GNU note, verifies hex-encoded build ID is unaffectedgo test ./...passes🤖 Generated with Claude Code