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riscv: Fix pmap_fault_fixup for L3 pages
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Authored by jrtc27 on Apr 6 2020, 8:41 PM.
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Details

Summary

The parentheses being in the wrong place means that, for L3 pages,
oldpte has all bits except PTE_V cleared, and so all the subsequent
checks against oldpte will fail, causing us to bail out and not retry
the faulting instruction after an SFENCE.VMA. This causes a WITNESS +
INVARIANTS kernel to fault on the "Chisel P3" (BOOM-based) DARPA SSITH
GFE SoC in pmap_init when writing to pv_table and, being a nofault
entry, subsequently panic with:

panic: vm_fault_lookup: fault on nofault entry, addr: 0xffffffc004e00000

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rS FreeBSD src repository - subversion
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