Messages in this thread | | | Date | Wed, 29 Oct 2008 12:55:30 -0500 | From | Nathan Fontenot <> | Subject | Re: [PATCH] Use correct page frame number to grab page zone lock |
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Disregard. It appears that Gerald Schaefer submitted a patch to fix this already.
http://lkml.org/lkml/2008/10/29/142
-Nathan
Nathan Fontenot wrote: > There are situations in which the 'pfn' variable used to calculate the > page zone can be invalid. One case is in the hotplug memory remove path > where we are trying to remove memory the last valid page frame for the > system. Passing an invalid page frame number to the pfn_to_page() macro > will cause the system to oops. > > Additionally I think this also solves an issue where we may be grabbing > the wrong zone->lock. This would occur when 'pfn' refers to a page > frame beyond what we are examining and lies in a different zone. > > Using the starting page frame number passed in appears to resolve > both of these issues. This patch also removes the redundant > initialization of 'pfn', it is set explicitly and then again in the for > loop. > > > Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> > --- > > Index: linux-2.6/mm/page_isolation.c > =================================================================== > --- linux-2.6.orig/mm/page_isolation.c 2008-10-13 12:00:46.000000000 > -0500 > +++ linux-2.6/mm/page_isolation.c 2008-10-29 11:18:39.000000000 -0500 > @@ -119,7 +119,6 @@ > struct zone *zone; > int ret; > > - pfn = start_pfn; > /* > * Note: pageblock_nr_page != MAX_ORDER. Then, chunks of free page > * is not aligned to pageblock_nr_pages. > @@ -133,7 +132,7 @@ > if (pfn < end_pfn) > return -EBUSY; > /* Check all pages are free or Marked as ISOLATED */ > - zone = page_zone(pfn_to_page(pfn)); > + zone = page_zone(pfn_to_page(start_pfn)); > spin_lock_irqsave(&zone->lock, flags); > ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn); > spin_unlock_irqrestore(&zone->lock, flags); > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/
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