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| author | Weijie Yang <weijie.yang@samsung.com> | 2015-05-14 01:01:46 +0000 |
|---|---|---|
| committer | Johannes Weiner <hannes@cmpxchg.org> | 2015-05-14 01:01:46 +0000 |
| commit | efabcecae99c62c690a0c1f059e1cf25709bbe4f (patch) | |
| tree | 18e5b20935eb0111fa79008d12ed26049274b422 | |
| parent | f5aca264bf62831ec13aa6e1097256174072d7df (diff) | |
| download | mm-next-efabcecae99c62c690a0c1f059e1cf25709bbe4f.tar.gz | |
mm: page_isolation: check pfn validity before access
In the undo path of start_isolate_page_range(), we need to check the pfn
validity before accessing its page, or it will trigger an addressing
exception if there is hole in the zone.
This issue is found by code-review not a test-trigger. In
"CONFIG_HOLES_IN_ZONE" environment, there is a certain chance that it
would casue an addressing exception when start_isolate_page_range()
fails, this could affect CMA, hugepage and memory-hotplug function.
Signed-off-by: Weijie Yang <weijie.yang@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | mm/page_isolation.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c index 303c908790efca..0e69d259beb7c3 100644 --- a/mm/page_isolation.c +++ b/mm/page_isolation.c @@ -178,8 +178,11 @@ int start_isolate_page_range(unsigned long start_pfn, unsigned long end_pfn, undo: for (pfn = start_pfn; pfn < undo_pfn; - pfn += pageblock_nr_pages) - unset_migratetype_isolate(pfn_to_page(pfn), migratetype); + pfn += pageblock_nr_pages) { + page = __first_valid_page(pfn, pageblock_nr_pages); + if (page) + unset_migratetype_isolate(page, migratetype); + } return -EBUSY; } |