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Set the arm64 Execute-never bits in more places.
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Authored by andrew on Apr 13 2017, 10:33 AM.
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Details

Summary

We need to set the Execute-never bits when mapping device memory
as the hardware may perform speculative instruction fetches.

Set the Privileged Execute-ever bit on userspace memory to stop
the kernel if it is tricked into executing it.

Diff Detail

Repository
rS FreeBSD src repository - subversion
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Event Timeline

kib added inline comments.
sys/arm64/arm64/pmap.c
2731 ↗(On Diff #27401)

Why using such rude check, instead of VM_MAXUSER_ADDRESS ?

This revision is now accepted and ready to land.Apr 13 2017, 12:45 PM
sys/arm64/arm64/pmap.c
2731 ↗(On Diff #27401)

I'm not sure why I did that.

This revision was automatically updated to reflect the committed changes.