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| author | YASUAKI ISHIMATSU <yasu.isimatu@gmail.com> | 2017-10-04 01:16:29 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-10-04 02:54:25 +0200 |
| commit | 1dd2bfc86818ddbc95f98e312e7704350223fd7d (patch) | |
| tree | 394d0f26cd302875089057232dca4c13fd4c82de | |
| parent | kernel/kcmp.c: drop branch leftover typo (diff) | |
| download | linux-1dd2bfc86818ddbc95f98e312e7704350223fd7d.tar.xz linux-1dd2bfc86818ddbc95f98e312e7704350223fd7d.zip | |
mm/memory_hotplug: change pfn_to_section_nr/section_nr_to_pfn macro to inline function
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.
Fixes: 815121d2b5cd ("memory_hotplug: clear zone when removing the memory")
Link: http://lkml.kernel.org/r/e643a387-e573-6bbf-d418-c60c8ee3d15e@gmail.com
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/mmzone.h | 10 | ||||
| -rw-r--r-- | 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 356a814e7c8e..c8f89417740b 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1094,8 +1094,14 @@ 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 23d5bd968950..efd1ad37bb57 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -551,7 +551,7 @@ 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); |