Date: Mon, 16 Sep 2013 10:34:44 +0000 (UTC) From: Zbigniew Bodek <zbb@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r255611 - head/sys/arm/arm Message-ID: <201309161034.r8GAYiuY078472@svn.freebsd.org>
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Author: zbb Date: Mon Sep 16 10:34:44 2013 New Revision: 255611 URL: http://svnweb.freebsd.org/changeset/base/255611 Log: Write protect base page after superpage demotion so that it may repromote When clearing the modification status of the superpage, one of the base pages produced during demotion should be marked as write disabled. The intention is that subsequent write access may repromote. In the current implementation this was done wrong as write permission was granted instead of forbidden. Approved by: cognet (mentor) Approved by: re Modified: head/sys/arm/arm/pmap-v6.c Modified: head/sys/arm/arm/pmap-v6.c ============================================================================== --- head/sys/arm/arm/pmap-v6.c Mon Sep 16 10:06:40 2013 (r255610) +++ head/sys/arm/arm/pmap-v6.c Mon Sep 16 10:34:44 2013 (r255611) @@ -987,7 +987,7 @@ pmap_clearbit(struct vm_page *m, u_int m ("pmap_clearbit: no PV " "entry for managed mapping")); pve->pv_flags &= ~PVF_WRITE; - *ptep &= ~L2_APX; + *ptep |= L2_APX; PTE_SYNC(ptep); } }
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