提交 c461ad6a 编写于 作者: M Mel Gorman 提交者: Linus Torvalds

mm, madvise: ensure poisoned pages are removed from per-cpu lists

Wendy Wang reported off-list that a RAS HWPOISON-SOFT test case failed
and bisected it to the commit 479f854a ("mm, page_alloc: defer
debugging checks of pages allocated from the PCP").

The problem is that a page that was poisoned with madvise() is reused.
The commit removed a check that would trigger if DEBUG_VM was enabled
but re-enabling the check only fixes the problem as a side-effect by
printing a bad_page warning and recovering.

The root of the problem is that an madvise() can leave a poisoned page
on the per-cpu list.  This patch drains all per-cpu lists after pages
are poisoned so that they will not be reused.  Wendy reports that the
test case in question passes with this patch applied.  While this could
be done in a targeted fashion, it is over-complicated for such a rare
operation.

Link: http://lkml.kernel.org/r/20170828133414.7qro57jbepdcyz5x@techsingularity.net
Fixes: 479f854a ("mm, page_alloc: defer debugging checks of pages allocated from the PCP")
Signed-off-by: NMel Gorman <mgorman@techsingularity.net>
Reported-by: NWang, Wendy <wendy.wang@intel.com>
Tested-by: NWang, Wendy <wendy.wang@intel.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: "Hansen, Dave" <dave.hansen@intel.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 355627f5
......@@ -613,6 +613,7 @@ static int madvise_inject_error(int behavior,
unsigned long start, unsigned long end)
{
struct page *page;
struct zone *zone;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
......@@ -646,6 +647,11 @@ static int madvise_inject_error(int behavior,
if (ret)
return ret;
}
/* Ensure that all poisoned pages are removed from per-cpu lists */
for_each_populated_zone(zone)
drain_all_pages(zone);
return 0;
}
#endif
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册