Date: Wed, 29 Sep 2004 19:20:40 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: src-committers@FreeBSD.org, cvs-src@FreeBSD.org, cvs-all@FreeBSD.org Subject: cvs commit: src/sys/amd64/amd64 pmap.c src/sys/amd64/include pmap.h src/sys/i386/i386 pmap.c src/sys/i386/include pmap.h Message-ID: <200409291920.i8TJKecC089719@repoman.freebsd.org>
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alc 2004-09-29 19:20:40 UTC
FreeBSD src repository
Modified files:
sys/amd64/amd64 pmap.c
sys/amd64/include pmap.h
sys/i386/i386 pmap.c
sys/i386/include pmap.h
Log:
Prevent the unexpected deallocation of a page table page while performing
pmap_copy(). This entails additional locking in pmap_copy() and the
addition of a "flags" parameter to the page table page allocator for
specifying whether it may sleep when memory is unavailable. (Already,
pmap_copy() checks the availability of memory, aborting if it is scarce.
In theory, another CPU could, however, allocate memory between
pmap_copy()'s check and the call to the page table page allocator,
causing the current thread to release its locks and sleep. This change
makes this scenario impossible.)
Reviewed by: tegge@
Revision Changes Path
1.503 +44 -21 src/sys/amd64/amd64/pmap.c
1.124 +1 -1 src/sys/amd64/include/pmap.h
1.509 +38 -18 src/sys/i386/i386/pmap.c
1.114 +1 -1 src/sys/i386/include/pmap.h
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