Date: Sat, 27 Sep 2003 03:30:03 -0700 (PDT) From: Bruce Evans <bde@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/i386/isa cy.c Message-ID: <200309271030.h8RAU3Jb016193@repoman.freebsd.org>
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bde 2003/09/27 03:30:03 PDT
FreeBSD src repository
Modified files:
sys/i386/isa cy.c
Log:
Quick fix for bitrot in locking in the SMP case. cd_getreg() and
cd_setreg() were still using !(read_eflags() & PSL_I) as the condition
for the lock hidden by COM_LOCK() (if any) being held. This worked
when spin mutexes and/or critical_enter() used hard interrupt disablement,
but it has caused recursion on the non-recursive mutex com_mtx since
all relevant interrupt disablement became soft. The recursion is
harmless unless there are other bugs, but it breaks an invariant so
it is fatal if spinlocks are witnessed.
Revision Changes Path
1.133 +24 -4 src/sys/i386/isa/cy.c
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