[Bug 269277] On 12.3, process-shared mutex may fail locking operations after usage of ANOTHER process-shared mutex.

From: <bugzilla-noreply_at_freebsd.org>
Date: Wed, 01 Feb 2023 15:38:08 UTC 
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=269277

            Bug ID: 269277
           Summary: On 12.3, process-shared mutex may fail locking
                    operations after usage of ANOTHER process-shared
                    mutex.
           Product: Base System
           Version: 12.3-RELEASE
          Hardware: amd64
                OS: Any
            Status: New
          Severity: Affects Some People
          Priority: ---
         Component: kern
          Assignee: bugs@FreeBSD.org
          Reporter: rau8344@gmail.com

Created attachment 239841
  --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=239841&action=edit
Minimal code to recreate issue

On FreeBSD 12.3 amd64, a process-shared mutex may fail locking operations after
usage of ANOTHER process-shared mutex. Original issue was seen running a
particular sequence of unit tests against a complex codebase; sometimes saw two
threads lock the same mutex at the same time, or fail on lock with EINVAL.
Issue recreated 

Recreated the EINVAL issue with a minimal example on a single thread (see
attached), both with gtest and without. Tested on two physical quad-core
machines (a Beckhoff 2040 and a Beckhoff 2042).

-- 
You are receiving this mail because:
You are the assignee for the bug.