Details

Reviewers

alc
markj
jhb

Commits

rS338715: Use ifunc to resolve context switching mode on amd64.
rS338712: Calculate PTI, PCID and INVPCID modes earlier, before ifuncs are resolved.
rS338711: Make the PTI violation check to follow style of the SMAP check.
rS338699: Remove unneeded new line from the panic string.

Summary

Patch removes all checks for pti/pcid/invpcid from the context switch path. I verified this by looking at the generated code. The invpcid_works1 trick required inline attribute for pmap_activate_sw_pcid_pti() to work.

The change requires moving of the pti and pcid_enabled initialization before ifunc resolution.

Trap.c change is mostly unrelated and just puts the PTI trap check into the same style as the SMAP trap check, also removing excessive new line from the panic message.

Diff Detail

Repository

rS FreeBSD src repository - subversion

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Unit

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Build Status

Buildable 19608

Event Timeline

kib created this revision.Sep 16 2018, 2:33 PM

Herald added a subscriber: imp. · View Herald TranscriptSep 16 2018, 2:33 PM

Harbormaster completed remote builds in B19607: Diff 48081.Sep 16 2018, 2:33 PM

markj accepted this revision.Sep 16 2018, 3:28 PM

markj added inline comments.

sys/amd64/amd64/machdep.c
1583	I'd add a comment explaining why we do this here.
sys/amd64/amd64/pmap.c
7466	Perhaps make invpcid_works1 const as a further hint?
sys/amd64/amd64/trap.c
711	Missing newline.

This revision is now accepted and ready to land.Sep 16 2018, 3:28 PM

Handle Mark' notes.

This revision now requires review to proceed.Sep 16 2018, 3:39 PM

Harbormaster completed remote builds in B19608: Diff 48082.Sep 16 2018, 3:39 PM

markj accepted this revision.Sep 16 2018, 4:05 PM

This revision is now accepted and ready to land.Sep 16 2018, 4:05 PM

alc accepted this revision.Sep 16 2018, 6:23 PM

alc added inline comments.

sys/amd64/amd64/machdep.c
1585	Rather than the also's and and's below, I would say it all up front: "Check for pti, pcid, and invpcid before ..."
1586	"... select the implementation ..."
sys/amd64/amd64/pmap.c
7482	I would say, "Explicitly", instead of "Manually". Then, add the word "automatically" to the next sentence, i.e., "... flushed automatically by ..." This comment and the ones in the later functions have been deindented by a tab, so you might try reflowing the text.
7522	"... used to handle an invalidate_all ..."
7524	"The below sequence of operations has ..."
7526	"... but the curpmap value has not yet been updated."
7527	"... causes the invltlb ... handler, which is called between ..."
7528	"... as a NOP ..."
7534	"... and the IPI ..."
sys/amd64/amd64/trap.c
715	Please insert a space into `)==`.