linux-kernel - Re: [RFC PATCH] mm: memblock: fix wrong memmove size in memblock_merge

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Date:	Mon, 07 Jan 2013 09:31:29 +0800
From:	Lin Feng <linfeng@...fujitsu.com>
To:	Wanpeng Li <liwanp@...ux.vnet.ibm.com>
CC:	akpm@...ux-foundation.org, tj@...nel.org, mingo@...nel.org,
	yinghai@...nel.org, benh@...nel.crashing.org,
	tangchen@...fujitsu.com, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [RFC PATCH] mm: memblock: fix wrong memmove size in memblock_merge_regions()



On 01/05/2013 09:04 AM, Wanpeng Li wrote:
> On Fri, Jan 04, 2013 at 05:10:50PM +0800, Lin Feng wrote:
>> The memmove span covers from (next+1) to the end of the array, and the index
>> of next is (i+1), so the index of (next+1) is (i+2). So the size of remaining
>> array elements is (type->cnt - (i + 2)).
>>
> 
> Make sense.
Hi Wanpeng,

Thanks for your review. I will add it in next version.

thanks,
linfeng
> 
> Reviewed-by: Wanpeng Li <liwanp@...ux.vnet.ibm.com>
> 
>> PS. It seems that memblock_merge_regions() could be made some improvement:
>> we need't memmove the remaining array elements until we find a none-mergable
>> element, but now we memmove everytime we find a neighboring compatible region.
>> I'm not sure if the trial is worth though.
>>
>> Cc: Tejun Heo <tj@...nel.org>
>> Signed-off-by: Lin Feng <linfeng@...fujitsu.com>
>> ---
>> mm/memblock.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/mm/memblock.c b/mm/memblock.c
>> index 6259055..85ce056 100644
>> --- a/mm/memblock.c
>> +++ b/mm/memblock.c
>> @@ -314,7 +314,7 @@ static void __init_memblock memblock_merge_regions(struct memblock_type *type)
>> 		}
>>
>> 		this->size += next->size;
>> -		memmove(next, next + 1, (type->cnt - (i + 1)) * sizeof(*next));
>> +		memmove(next, next + 1, (type->cnt - (i + 2)) * sizeof(*next));
>> 		type->cnt--;
>> 	}
>> }
>> -- 
>> 1.7.11.7
> 
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/