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mm: check the return value of lookup_page_ext for all call sites

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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>
This commit is contained in:
Yang Shi
2016-06-03 14:55:38 -07:00
committed by Linus Torvalds
parent d8bae33ddd
commit f86e427197
5 changed files with 77 additions and 8 deletions
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43
include/linux/page_idle.h
View File

@@ -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 */