From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-f66.google.com ([74.125.83.66]:32919 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752548AbeC3Ceo (ORCPT ); Thu, 29 Mar 2018 22:34:44 -0400 Received: by mail-pg0-f66.google.com with SMTP id i194so4266120pgd.0 for ; Thu, 29 Mar 2018 19:34:44 -0700 (PDT) From: Wei Yang To: akpm@linux-foundation.org, mhocko@suse.com, yinghai@kernel.org Cc: inux-mm@kvack.org, Wei Yang , "3 . 12" Subject: [PATCH] mm/memblock: fix potential issue in memblock_search_pfn_nid() Date: Fri, 30 Mar 2018 10:34:15 +0800 Message-Id: <20180330023415.20165-1-richard.weiyang@gmail.com> Sender: stable-owner@vger.kernel.org List-ID: 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 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