linux-kernel - Re: [v3 9/9] s390: teach platforms not to zero struct pages memory

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

Date:   Mon, 15 May 2017 20:33:29 -0400
From:   Pasha Tatashin <pasha.tatashin@...cle.com>
To:     Heiko Carstens <heiko.carstens@...ibm.com>
Cc:     linux-kernel@...r.kernel.org, sparclinux@...r.kernel.org,
        linux-mm@...ck.org, linuxppc-dev@...ts.ozlabs.org,
        linux-s390@...r.kernel.org, borntraeger@...ibm.com,
        davem@...emloft.net
Subject: Re: [v3 9/9] s390: teach platforms not to zero struct pages memory

Ah OK, I will include the change.

Thank you,
Pasha

On 05/15/2017 07:17 PM, Heiko Carstens wrote:
> Hello Pasha,
> 
>> Thank you for looking at this patch. I am worried to make the proposed
>> change, because, as I understand in this case we allocate memory not for
>> "struct page"s but for table that hold them. So, we will change the behavior
>> from the current one, where this table is allocated zeroed, but now it won't
>> be zeroed.
> 
> The page table, if needed, is allocated and populated a couple of lines
> above. See the vmem_pte_alloc() call. So my request to include the hunk
> below is still valid ;)
> 
>>> If you add the hunk below then this is
>>>
>>> Acked-by: Heiko Carstens <heiko.carstens@...ibm.com>
>>>
>>> diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
>>> index ffe9ba1aec8b..bf88a8b9c24d 100644
>>> --- a/arch/s390/mm/vmem.c
>>> +++ b/arch/s390/mm/vmem.c
>>> @@ -272,7 +272,7 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
>>>   		if (pte_none(*pt_dir)) {
>>>   			void *new_page;
>>> -			new_page = vmemmap_alloc_block(PAGE_SIZE, node, true);
>>> +			new_page = vmemmap_alloc_block(PAGE_SIZE, node, VMEMMAP_ZERO);
>>>   			if (!new_page)
>>>   				goto out;
>>>   			pte_val(*pt_dir) = __pa(new_page) | pgt_prot;
>>>
>>
> 
> --
> To unsubscribe, send a message with 'unsubscribe linux-mm' in
> the body to majordomo@...ck.org.  For more info on Linux MM,
> see: http://www.linux-mm.org/ .
> Don't email: <a href=mailto:"dont@...ck.org"> email@...ck.org </a>
>