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| author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2016-05-21 01:58:50 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-21 02:58:30 +0200 |
| commit | e570f56cccd215db68e50870ee74b7d9c0022109 (patch) | |
| tree | 0db14373c0f65bcc7360995920b8ed0e46a0d5de /mm | |
| parent | mm, kasan: fix to call kasan_free_pages() after poisoning page (diff) | |
| download | linux-e570f56cccd215db68e50870ee74b7d9c0022109.tar.xz linux-e570f56cccd215db68e50870ee74b7d9c0022109.zip | |
mm: check_new_page_bad() directly returns in __PG_HWPOISON case
Currently we check page->flags twice for "HWPoisoned" case of
check_new_page_bad(), which can cause a race with unpoisoning.
This race unnecessarily taints kernel with "BUG: Bad page state".
check_new_page_bad() is the only caller of bad_page() which is
interested in __PG_HWPOISON, so let's move the hwpoison related code in
bad_page() to it.
Link: http://lkml.kernel.org/r/20160518100949.GA17299@hori1.linux.bs1.fc.nec.co.jp
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/page_alloc.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 383b14b4f61d..f8f3bfc435ee 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -522,12 +522,6 @@ static void bad_page(struct page *page, const char *reason, static unsigned long nr_shown; static unsigned long nr_unshown; - /* Don't complain about poisoned pages */ - if (PageHWPoison(page)) { - page_mapcount_reset(page); /* remove PageBuddy */ - return; - } - /* * Allow a burst of 60 reports, then keep quiet for that minute; * or allow a steady drip of one report per second. @@ -1654,6 +1648,9 @@ static void check_new_page_bad(struct page *page) if (unlikely(page->flags & __PG_HWPOISON)) { bad_reason = "HWPoisoned (hardware-corrupted)"; bad_flags = __PG_HWPOISON; + /* Don't complain about hwpoisoned pages */ + page_mapcount_reset(page); /* remove PageBuddy */ + return; } if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) { bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; |