clockcalib: Fix an overflow bug
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Authored by markj on Jan 19 2022, 10:49 PM.

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rGc3196306f092: clockcalib: Fix an overflow bug

Summary

tc_counter_mask is an unsigned int and in the TSC timecounter is equal
to UINT_MAX, so the addition tc->tc_counter_mask + 1 can overflow to 0,
resulting in a hang during boot.

Fixes: c2705ceaeb09 ("x86: Speed up clock calibration")

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rG FreeBSD src repository

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markj created this revision.Jan 19 2022, 10:49 PM

Herald added a subscriber: imp. · View Herald TranscriptJan 19 2022, 10:49 PM

markj requested review of this revision.Jan 19 2022, 10:49 PM

Harbormaster completed remote builds in B43996: Diff 101660.Jan 19 2022, 10:49 PM

Oops! Thanks for catching this.

This revision is now accepted and ready to land.Jan 20 2022, 5:49 AM

Closed by commit rGc3196306f092: clockcalib: Fix an overflow bug (authored by markj). · Explain WhyJan 20 2022, 2:59 PM

This revision was automatically updated to reflect the committed changes.

markj added a commit: rGc3196306f092: clockcalib: Fix an overflow bug.

@markj could it be possible to backport this fix to the FreeBSD 13.1 while there is still time?
My FreeBSD 13.1 VM (virtualbox) freezes randomly during boot and this commit fixes it.

In D33956#796309, @sebastien.bini_stormshield.eu wrote:

@markj could it be possible to backport this fix to the FreeBSD 13.1 while there is still time?
My FreeBSD 13.1 VM (virtualbox) freezes randomly during boot and this commit fixes it.

Oh. Ugh. I didn't realize that this was never backported. :(

And of course RC6 is already building. Ok, I'll see what I can do. Thanks for the report.

Thank you for the backport :) !

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sys/

kern/

subr_clockcalib.c

2 lines

Diff 101682

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sys/kern/subr_clockcalib.c

clockcalib: Fix an overflow bugClosedPublicActions