Page MenuHomeFreeBSD

Set the arm64 Execute-never bits in more places.
ClosedPublic

Authored by andrew on Apr 13 2017, 10:33 AM.
Tags
None
Referenced Files
Unknown Object (File)
Wed, Apr 23, 4:47 AM
Unknown Object (File)
Tue, Apr 22, 7:11 AM
Unknown Object (File)
Mon, Apr 21, 12:28 PM
Unknown Object (File)
Sat, Apr 19, 8:31 AM
Unknown Object (File)
Apr 1 2025, 6:58 PM
Unknown Object (File)
Mar 16 2025, 2:50 PM
Unknown Object (File)
Jan 28 2025, 11:44 PM
Unknown Object (File)
Jan 10 2025, 4:08 PM
Subscribers

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
Lint
Lint Not Applicable
Unit
Tests Not Applicable

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.