Fix bug in TPM 2.0 TIS driver.
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Authored by darrick.freebsd_gmail.com on Jan 8 2020, 2:37 AM.

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Reviewers

mw
cem
takawata
vangyzen

Commits

rS357386: tpm(4): Fix 'go ready' in TPM 2.0 TIS driver

Summary

tpmtis_go_ready() reads the value of the TPM_STS register and ORs TPM_STS_CMD_READY to the existing value and writes it back to the register. However, the TPM Profile (PTP) specification states that only one bit in the write request value may be set to 1, or else the entire write request is ignored.

Also removed call which clears the TPM_STS_CMD_READY flag in the same call. It was being ignored for the same reasons.

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rS FreeBSD src repository - subversion

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Event Timeline

darrick.freebsd_gmail.com created this revision.Jan 8 2020, 2:37 AM

Harbormaster completed remote builds in B28532: Diff 66474.Jan 8 2020, 2:37 AM

(I suspect all of these AND4/OR4 constructs are dubious and should be removed in favor of explicit AND/ORing as necessary, but that's a larger cleanup than fixing the bug.)

This revision is now accepted and ready to land.Jan 8 2020, 2:55 AM

cem added a reviewer: takawata.Jan 8 2020, 2:57 AM

vangyzen accepted this revision.Jan 10 2020, 8:00 PM

Closed by commit rS357386: tpm(4): Fix 'go ready' in TPM 2.0 TIS driver (authored by cem). · Explain WhyFeb 1 2020, 8:38 PM

This revision was automatically updated to reflect the committed changes.

cem added a commit: rS357386: tpm(4): Fix 'go ready' in TPM 2.0 TIS driver.

Herald added a subscriber: imp. · View Herald TranscriptFeb 1 2020, 8:38 PM