Re: [Bug fix PATCH] resource: Reusing a resource structure allocated by bootmem

[Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>]

Hi Rui,

Thank you for your review.

2013/04/16 17:17, Wang, Rui Y wrote:
>> -----Original Message-----
>> From: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>> Date: Mon, 15 Apr 2013 11:15:28 +0900
>> Subject: [Bug fix PATCH] resource: Reusing a resource structure allocated by
>> bootmem
>> To: akpm@linux-foundation.org
>> Cc: linux-kernel@vger.kernel.org, rientjes@google.com, linuxram@us.ibm.com,
>> toshi.kani@hp.com, Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
>> <<...>>
>> +	if (bootmem_resource.sibling) {
>> +		spin_lock(&bootmem_resource_lock);
>> +		res = bootmem_resource.sibling;
>> +		bootmem_resource.sibling = res->sibling;
>> +		spin_unlock(&bootmem_resource_lock);
>> +		memset(res, 0, sizeof(struct resource));
>> +	} else {
>> +		res = kzalloc(sizeof(struct resource), flags);
>> +	}
>

> bootmem_resource_lock does not protect the if() statement from accessing bootmem_resource.sibling.
>
> spin_lock(&bootmem_resource_lock);
> if (bootmem_resource.sibling) {

You are right. I'll update it.

Thanks,
Yasuaki Ishimatsu

> ...
>
> Rui
>