amd64: Add MD bits for KASAN
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Authored by markj on Mar 27 2021, 11:28 PM.

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Reviewers: None
Commits: rGf115c0612131: amd64: Add MD bits for KASAN

Summary

- Initialize KASAN before executing SYSINITs.
- Add a kernel config.
- Increase the kernel stack size if KASAN is enabled. Some of the
ASAN instrumentation increases stack usage and it's enough to
trigger stack overflows in ZFS.
- Mark the trapframe as valid in interrupt handlers if it is
assigned to td_intr_frame. Otherwise, an interrupt in a function
which creates a poisoned alloca region can trigger false positives.

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Repository

rG FreeBSD src repository

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Event Timeline

markj created this revision.Mar 27 2021, 11:28 PM

Herald added a subscriber: imp. · View Herald TranscriptMar 27 2021, 11:28 PM

markj requested review of this revision.Mar 27 2021, 11:28 PM

Harbormaster completed remote builds in B38126: Diff 86412.Mar 27 2021, 11:28 PM

emaste added a subscriber: emaste.Mar 28 2021, 1:30 AM

andrew added a subscriber: andrew.Mar 29 2021, 12:18 PM

andrew added inline comments.

sys/amd64/conf/GENERIC-KMSAN
7 ↗	(On Diff #86412)	`KMSAN`?
sys/amd64/include/param.h
138	Why do we need more pages for `KASAN`?

markj marked an inline comment as done.Mar 29 2021, 1:42 PM

markj added inline comments.

sys/amd64/conf/GENERIC-KMSAN
7 ↗	(On Diff #86412)	I have a WIP KMSAN port as well, just didn't split this commit properly.
sys/amd64/include/param.h
138	Some of the ASAN options seem to increase stack usage rather substantially. I was able to trigger a double fault with ZFS due to a stack overflow with 4 kstack pages.