KLP for Clang LTO Kernel
summary
Clang LTO live patching runs on top of kpatch by comparing linker-produced pre-link objects instead of the full vmlinux, using clang’s lto object-pass dump to dumped ~2000 internal .o files and then running objtool and the usual diff flow; linking vmlinux.o directly takes >10 hours for vmlinux.o so the dump trick makes patch generation feasible. LTO adds special symbols and duplicated comment sections that kpatch must ignore; PG is in production 2+ years, LTO rollout hits ~50k nodes and sampled-LBR PGO so far underperforms instrumentation.
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chapters (6)
- 0:00Introduction to KLP with Clang LTO
- 2:55LTO workflow and KP integration
- 7:17KP changes for LTO and PGO support
- 12:47IBT challenges with live patching
- 18:17Future of KP and alternatives
- 20:45Q&A and next steps
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