nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

mm: check_new_page_bad() directly returns in __PG_HWPOISON case

Browse source 
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>
This commit is contained in:
Naoya Horiguchi 2016-05-20 16:58:50 -07:00 committed by Linus Torvalds
parent 29b52de182
commit e570f56ccc
1 changed files with 3 additions and 6 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

9
mm/page_alloc.c
View file

@ -522,12 +522,6 @@ static void bad_page(struct page *page, const char *reason,
static unsigned long nr_shown; static unsigned long nr_shown;
static unsigned long nr_unshown; 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; * Allow a burst of 60 reports, then keep quiet for that minute;
* or allow a steady drip of one report per second. * 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)) { if (unlikely(page->flags & __PG_HWPOISON)) {
bad_reason = "HWPoisoned (hardware-corrupted)"; bad_reason = "HWPoisoned (hardware-corrupted)";
bad_flags = __PG_HWPOISON; 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)) { if (unlikely(page->flags & PAGE_FLAGS_CHECK_AT_PREP)) {
bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set"; bad_reason = "PAGE_FLAGS_CHECK_AT_PREP flag set";