memblock_search_pfn_nid() returns the nid and the [start|end]_pfn of the memory region where pfn sits in. While the calculation of start_pfn has potential issue when the regions base is not page aligned. For example, we assume PAGE_SHIFT is 12 and base is 0x1234. Current implementation would return 1 while this is not correct. This patch fixes this by using PFN_UP(). The original commit is commit e76b63f80d93 ("memblock, numa: binary search node id") and merged in v3.12. Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> Cc: 3.12+ <stable@xxxxxxxxxxxxxxx> --- * add He Jia in cc * fix the mm mail list address * Cc: 3.12+ --- mm/memblock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memblock.c b/mm/memblock.c index b6ba6b7adadc..de768307696d 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1673,7 +1673,7 @@ int __init_memblock memblock_search_pfn_nid(unsigned long pfn, if (mid == -1) return -1; - *start_pfn = PFN_DOWN(type->regions[mid].base); + *start_pfn = PFN_UP(type->regions[mid].base); *end_pfn = PFN_DOWN(type->regions[mid].base + type->regions[mid].size); return type->regions[mid].nid; -- 2.15.1