Messages in this thread | | | Date | Thu, 21 Apr 2016 16:44:54 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH] mm/memory-failure: fix race with compound page split/merge |
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On Mon, 18 Apr 2016 23:15:52 +0000 Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> wrote:
> # CCed Andrew,
Thanks.
> On Mon, Apr 18, 2016 at 02:43:45PM +0300, Konstantin Khlebnikov wrote: > > Get_hwpoison_page() must recheck relation between head and tail pages. > > > > Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> > > Looks good to me. Without this recheck, the race causes kernel to pin > an irrelevant page, and finally makes kernel crash for refcount mismcach...
Thanks. I'll add the above (important!) info to the changelog and cc:stable.
> > - return get_page_unless_zero(head); > > + if (get_page_unless_zero(head)) { > > + if (head == compound_head(page)) > > + return 1; > > + > > + pr_info("MCE: %#lx cannot catch tail\n", page_to_pfn(page)); > > Recently Chen Yucong replaced the label "MCE:" with "Memory failure:", > but the resolution is trivial, I think.
Yup, that patch is in my (large) backlog. Away at conferences for seven days, receiving 100 actionable emails per day. Give me a few days ;)
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