Messages in this thread Patch in this message | | | Subject | [PATCH 1/2] mm/memory_hotplug: Change pfn_to_section_nr/section_nr_to_pfn macro to inline function | From | YASUAKI ISHIMATSU <> | Date | Fri, 15 Sep 2017 22:52:20 -0400 |
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pfn_to_section_nr() and section_nr_to_pfn() are defined as macro. pfn_to_section_nr() has no issue even if it is defined as macro. But section_nr_to_pfn() has overflow issue if sec is defined as int.
section_nr_to_pfn() just shifts sec by PFN_SECTION_SHIFT. If sec is defined as unsigned long, section_nr_to_pfn() returns pfn as 64 bit value. But if sec is defined as int, section_nr_to_pfn() returns pfn as 32 bit value.
__remove_section() calculates start_pfn using section_nr_to_pfn() and scn_nr defined as int. So if hot-removed memory address is over 16TB, overflow issue occurs and section_nr_to_pfn() does not calculate correct pfn.
To make callers use proper arg, the patch changes the macros to inline functions.
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> --- include/linux/mmzone.h | 10 ++++++++-- mm/memory_hotplug.c | 2 +- 2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index ef6a13b..6ae12b2 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1073,8 +1073,14 @@ static inline unsigned long early_pfn_to_nid(unsigned long pfn) #error Allocator MAX_ORDER exceeds SECTION_SIZE #endif
-#define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT) -#define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT) +static inline unsigned long pfn_to_section_nr(unsigned long pfn) +{ + return pfn >> PFN_SECTION_SHIFT; +} +static inline unsigned long section_nr_to_pfn(unsigned long sec) +{ + return sec << PFN_SECTION_SHIFT; +}
#define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index b63d7d1..38c3c37 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -798,7 +798,7 @@ static int __remove_section(struct zone *zone, struct mem_section *ms, return ret;
scn_nr = __section_nr(ms); - start_pfn = section_nr_to_pfn(scn_nr); + start_pfn = section_nr_to_pfn((unsigned long)scn_nr); __remove_zone(zone, start_pfn);
sparse_remove_one_section(zone, ms, map_offset); -- 1.8.3.1
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