Fix an off-by-one in vm_map_pmap_enter().
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Authored by markj on Dec 4 2019, 5:31 PM.

Details

Reviewers

alc
kib
dougm

Commits

rS355399: Fix an off-by-one error in vm_map_pmap_enter().

Summary

The set of valid pindices in an object of size N is [0, N-1]. I
believe this bug is harmless: we would set psize = 0, causing the
remainder of vm_map_pmap_enter() to do nothing.

Submitted by: Wuyang Chung <wuyang.chung1@gmail.com>

Diff Detail

Repository

rS FreeBSD src repository - subversion

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Event Timeline

markj created this revision.Dec 4 2019, 5:31 PM

Harbormaster completed remote builds in B27946: Diff 65218.Dec 4 2019, 5:31 PM

markj added reviewers: alc, kib, dougm.Dec 4 2019, 5:31 PM

dougm accepted this revision.Dec 4 2019, 5:45 PM

This revision is now accepted and ready to land.Dec 4 2019, 5:45 PM

kib accepted this revision.Dec 4 2019, 5:50 PM

alc accepted this revision.Dec 4 2019, 6:54 PM

alc added inline comments.

sys/vm/vm_map.c
2459–2460 ↗	(On Diff #65218)	As an aside, I want to ask if we can't retire pmap_object_init_pt(). More precisely, hasn't vm_fault_populate() subsumed the essential point of pmap_object_init_pt(), to create superpage mappings for some devices, like frame buffers?