Files
linux/include/linux
Naoya Horiguchi 25182f05ff mm,hwpoison: fix race with hugetlb page allocation
When hugetlb page fault (under overcommitting situation) and
memory_failure() race, VM_BUG_ON_PAGE() is triggered by the following
race:

    CPU0:                           CPU1:

                                    gather_surplus_pages()
                                      page = alloc_surplus_huge_page()
    memory_failure_hugetlb()
      get_hwpoison_page(page)
        __get_hwpoison_page(page)
          get_page_unless_zero(page)
                                      zero = put_page_testzero(page)
                                      VM_BUG_ON_PAGE(!zero, page)
                                      enqueue_huge_page(h, page)
      put_page(page)

__get_hwpoison_page() only checks the page refcount before taking an
additional one for memory error handling, which is not enough because
there's a time window where compound pages have non-zero refcount during
hugetlb page initialization.

So make __get_hwpoison_page() check page status a bit more for hugetlb
pages with get_hwpoison_huge_page().  Checking hugetlb-specific flags
under hugetlb_lock makes sure that the hugetlb page is not transitive.
It's notable that another new function, HWPoisonHandlable(), is helpful
to prevent a race against other transitive page states (like a generic
compound page just before PageHuge becomes true).

Link: https://lkml.kernel.org/r/20210603233632.2964832-2-nao.horiguchi@gmail.com
Fixes: ead07f6a86 ("mm/memory-failure: introduce get_hwpoison_page() for consistent refcount handling")
Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reported-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: <stable@vger.kernel.org>	[5.12+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-16 09:24:42 -07:00
..
2021-02-02 00:16:57 +01:00
2021-01-23 14:57:21 +01:00
2021-05-18 17:24:52 +01:00
2021-05-06 19:24:11 -07:00
2021-04-14 16:30:30 +03:00
2021-05-08 21:49:48 -06:00
2021-01-24 14:27:17 +01:00
2021-02-26 09:41:03 -08:00
2021-04-08 16:04:20 -07:00
2021-05-24 12:45:26 -04:00
2021-05-24 12:45:26 -04:00
2021-04-08 16:04:20 -07:00
2021-04-08 16:04:20 -07:00
2021-01-21 14:06:00 -07:00
2021-05-06 19:24:11 -07:00
2021-04-19 13:13:26 -04:00
2021-01-18 14:26:51 +01:00
2021-03-22 03:57:39 +01:00
2021-02-08 12:28:07 +01:00
2021-04-12 15:04:23 +02:00
2021-03-30 22:37:06 +02:00
2021-05-07 00:26:34 -07:00
2021-02-11 13:24:44 -08:00
2021-04-30 11:20:40 -07:00
2021-03-22 04:23:14 +01:00
2021-04-05 22:39:38 -04:00
2021-01-21 16:16:10 +00:00
2021-02-26 09:41:02 -08:00
2021-02-26 09:41:03 -08:00
2021-01-22 15:09:42 +01:00
2021-05-14 19:41:32 -07:00
2021-04-08 16:04:20 -07:00
2021-04-06 08:34:39 +02:00
2021-02-17 13:17:49 -08:00
2021-04-21 10:24:41 -05:00
2021-02-26 09:40:59 -08:00
2021-02-03 19:05:50 +01:00
2021-01-24 14:27:17 +01:00
2021-01-24 14:27:20 +01:00
2021-03-06 12:40:22 +01:00
2021-02-26 09:41:03 -08:00
2021-03-17 14:16:15 -05:00
2021-01-16 23:19:26 +01:00
2021-03-22 02:45:52 +01:00
2021-03-18 12:58:27 -04:00
2021-05-06 19:24:11 -07:00
2021-03-19 04:58:25 +00:00
2021-03-25 17:39:33 -07:00
2021-03-10 09:34:06 +01:00
2021-04-15 10:32:17 +02:00
2021-02-13 17:17:53 +01:00
2021-03-30 17:06:49 -07:00
2021-04-26 22:55:12 +01:00
2021-04-09 16:00:00 +02:00
2021-01-21 16:16:10 +00:00
2021-03-22 15:02:14 +01:00
2021-05-07 00:26:35 -07:00
2021-02-09 12:15:07 +01:00
2021-01-21 14:06:00 -07:00
2021-04-16 15:31:02 -07:00
2021-03-30 13:42:33 -04:00
2021-01-24 14:27:17 +01:00
2021-02-08 22:58:55 +01:00