Date: Wed, 24 Feb 2010 00:54:37 +0000 (UTC) From: Nathan Whitehorn <nwhitehorn@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/powerpc/aim mmu_oea64.c src/sys/powerpc/include pte.h Message-ID: <201002240054.o1O0suWe076194@repoman.freebsd.org>
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nwhitehorn 2010-02-24 00:54:37 UTC
FreeBSD src repository
Modified files:
sys/powerpc/aim mmu_oea64.c
sys/powerpc/include pte.h
Log:
SVN rev 204268 on 2010-02-24 00:54:37Z by nwhitehorn
Close a race involving the OEA64 scratchpage. When the scratch page's
physical address is changed, there is a brief window during which its PTE
is invalid. Since moea64_set_scratchpage_pa() does not and cannot hold
the page table lock, it was possible for another CPU to insert a new PTE
into the scratch page's PTEG slot during this interval, corrupting both
mappings.
Solve this by creating a new flag, LPTE_LOCKED, such that
moea64_pte_insert will avoid claiming locked PTEG slots even if they
are invalid. This change also incorporates some additional paranoia
added to solve things I thought might be this bug.
Reported by: linimon
Revision Changes Path
1.14 +14 -10 src/sys/powerpc/aim/mmu_oea64.c
1.10 +1 -0 src/sys/powerpc/include/pte.h
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