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authorYang Shi <yang.shi@linaro.org>2016-06-04 00:55:38 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-06-04 01:06:22 +0300
commitf86e4271978bd93db466d6a95dad4b0fdcdb04f6 (patch)
tree26ef29934495da598a11c3a177d0294a71c5eae8 /include
parentd8bae33dddc03dc652e1d8cfceebf4f753939de7 (diff)
downloadlinux-f86e4271978bd93db466d6a95dad4b0fdcdb04f6.tar.xz
mm: check the return value of lookup_page_ext for all call sites
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>
Diffstat (limited to 'include')
-rw-r--r--include/linux/page_idle.h43
1 files changed, 36 insertions, 7 deletions
diff --git a/include/linux/page_idle.h b/include/linux/page_idle.h
index bf268fa92c5b..fec40271339f 100644
--- a/include/linux/page_idle.h
+++ b/include/linux/page_idle.h
@@ -46,33 +46,62 @@ extern struct page_ext_operations page_idle_ops;
static inline bool page_is_young(struct page *page)
{
- return test_bit(PAGE_EXT_YOUNG, &lookup_page_ext(page)->flags);
+ struct page_ext *page_ext = lookup_page_ext(page);
+
+ if (unlikely(!page_ext))
+ return false;
+
+ return test_bit(PAGE_EXT_YOUNG, &page_ext->flags);
}
static inline void set_page_young(struct page *page)
{
- set_bit(PAGE_EXT_YOUNG, &lookup_page_ext(page)->flags);
+ struct page_ext *page_ext = lookup_page_ext(page);
+
+ if (unlikely(!page_ext))
+ return;
+
+ set_bit(PAGE_EXT_YOUNG, &page_ext->flags);
}
static inline bool test_and_clear_page_young(struct page *page)
{
- return test_and_clear_bit(PAGE_EXT_YOUNG,
- &lookup_page_ext(page)->flags);
+ struct page_ext *page_ext = lookup_page_ext(page);
+
+ if (unlikely(!page_ext))
+ return false;
+
+ return test_and_clear_bit(PAGE_EXT_YOUNG, &page_ext->flags);
}
static inline bool page_is_idle(struct page *page)
{
- return test_bit(PAGE_EXT_IDLE, &lookup_page_ext(page)->flags);
+ struct page_ext *page_ext = lookup_page_ext(page);
+
+ if (unlikely(!page_ext))
+ return false;
+
+ return test_bit(PAGE_EXT_IDLE, &page_ext->flags);
}
static inline void set_page_idle(struct page *page)
{
- set_bit(PAGE_EXT_IDLE, &lookup_page_ext(page)->flags);
+ struct page_ext *page_ext = lookup_page_ext(page);
+
+ if (unlikely(!page_ext))
+ return;
+
+ set_bit(PAGE_EXT_IDLE, &page_ext->flags);
}
static inline void clear_page_idle(struct page *page)
{
- clear_bit(PAGE_EXT_IDLE, &lookup_page_ext(page)->flags);
+ struct page_ext *page_ext = lookup_page_ext(page);
+
+ if (unlikely(!page_ext))
+ return;
+
+ clear_bit(PAGE_EXT_IDLE, &page_ext->flags);
}
#endif /* CONFIG_64BIT */