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authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2016-05-20 16:58:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-20 17:58:30 -0700
commite570f56cccd215db68e50870ee74b7d9c0022109 (patch)
tree0db14373c0f65bcc7360995920b8ed0e46a0d5de
parent29b52de182acf50f85a8284ad39104d84c9bbf57 (diff)
downloadlinux-e570f56cccd215db68e50870ee74b7d9c0022109.tar.bz2
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>
-rw-r--r--mm/page_alloc.c9
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";