diff options
| author | Yang Shi <yang.shi@linaro.org> | 2016-06-03 14:55:38 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-24 08:32:25 +0100 |
| commit | e34e744f70a68f8f16f945a286802898c56a8b5a (patch) | |
| tree | 8f8d3bd244b194e9a3df7e988297436427783286 /mm/debug-pagealloc.c | |
| parent | 7b7a1c39e8394d4232714093882b733b3e435c67 (diff) | |
mm: check the return value of lookup_page_ext for all call sites
commit f86e4271978bd93db466d6a95dad4b0fdcdb04f6 upstream.
Per the discussion with Joonsoo Kim [1], we need check the return value
of lookup_page_ext() for all call sites since it might return NULL in
some cases, although it is unlikely, i.e. memory hotplug.
Tested with ltp with "page_owner=0".
[1] http://lkml.kernel.org/r/20160519002809.GA10245@js1304-P5Q-DELUXE
[akpm@linux-foundation.org: fix build-breaking typos]
[arnd@arndb.de: fix build problems from lookup_page_ext]
Link: http://lkml.kernel.org/r/6285269.2CksypHdYp@wuerfel
[akpm@linux-foundation.org: coding-style fixes]
Link: http://lkml.kernel.org/r/1464023768-31025-1-git-send-email-yang.shi@linaro.org
Signed-off-by: Yang Shi <yang.shi@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm/debug-pagealloc.c')
| -rw-r--r-- | mm/debug-pagealloc.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/mm/debug-pagealloc.c b/mm/debug-pagealloc.c index 5bf5906ce13b..fe1c61f7cf26 100644 --- a/mm/debug-pagealloc.c +++ b/mm/debug-pagealloc.c @@ -34,6 +34,8 @@ static inline void set_page_poison(struct page *page) struct page_ext *page_ext; page_ext = lookup_page_ext(page); + if (page_ext) + return; __set_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags); } @@ -42,6 +44,8 @@ static inline void clear_page_poison(struct page *page) struct page_ext *page_ext; page_ext = lookup_page_ext(page); + if (page_ext) + return; __clear_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags); } @@ -50,6 +54,8 @@ static inline bool page_poison(struct page *page) struct page_ext *page_ext; page_ext = lookup_page_ext(page); + if (page_ext) + return false; return test_bit(PAGE_EXT_DEBUG_POISON, &page_ext->flags); } |