Fix memguard(9) when INVARIANTS is enabled.
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Authored by markj on May 25 2016, 7:09 PM.

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Reviewers

jmg
glebius

Commits

rS301176: Fix memguard(9) in kernels with INVARIANTS enabled.

Summary

With r284861, zones use the trash ctor and dtor by default. This is
incompatible with memguard. Modify the UMA debug functions to be
no-ops if the item was allocated from memguard. This also fixes ctors
such as mb_ctor_pack(), which invokes the trash ctor in addition to
performing some initialization.

Test Plan

Added a sysctl-controlled use-after-free to the filedesc0 zone and verified that memguard caught it when enabled, and that the trash ctor caught it otherwise.

Diff Detail

Repository

rS FreeBSD src repository - subversion

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Tests Not Applicable

Event Timeline

markj updated this revision to Diff 16869.May 25 2016, 7:09 PM

markj retitled this revision from to Fix memguard(9) when INVARIANTS is enabled..

markj edited the test plan for this revision. (Show Details)

markj updated this object.

Herald added a subscriber: imp. · View Herald TranscriptMay 25 2016, 7:09 PM

markj edited the test plan for this revision. (Show Details)May 25 2016, 7:14 PM

markj added a reviewer: glebius.

ping?

I missed the r284861. I don't like it, since it creates extra CPU cycles for non-INVARIANTS kernel. First I'd like to see that addressed, and then get bug to MEMGUARD issue.

glebius added a reviewer: jmg.Jun 1 2016, 4:10 PM

Of course my previous comment was wrong. I need to spend more time reviewing before commenting. Sorry.

In D6562#140851, @glebius wrote:

I missed the r284861. I don't like it, since it creates extra CPU cycles for non-INVARIANTS kernel. First I'd like to see that addressed, and then get bug to MEMGUARD issue.

How does it affect a non-INVARIANTS kernel?

glebius accepted this revision.Jun 1 2016, 6:04 PM

glebius edited edge metadata.

This revision is now accepted and ready to land.Jun 1 2016, 6:04 PM

Closed by commit rS301176: Fix memguard(9) in kernels with INVARIANTS enabled. (authored by markj). · Explain WhyJun 1 2016, 10:31 PM

This revision was automatically updated to reflect the committed changes.