linux-kernel - Re: [PATCH v2 1/2] mm/userfaultfd: don't place zeropages when zeropages are disallowed

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: Thu, 11 Apr 2024 14:30:34 +0200
From: David Hildenbrand <david@...hat.com>
To: Alexander Gordeev <agordeev@...ux.ibm.com>
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org,
 Christian Borntraeger <borntraeger@...ux.ibm.com>,
 Janosch Frank <frankja@...ux.ibm.com>,
 Claudio Imbrenda <imbrenda@...ux.ibm.com>, Heiko Carstens
 <hca@...ux.ibm.com>, Vasily Gorbik <gor@...ux.ibm.com>,
 Andrew Morton <akpm@...ux-foundation.org>, Peter Xu <peterx@...hat.com>,
 Sven Schnelle <svens@...ux.ibm.com>,
 Gerald Schaefer <gerald.schaefer@...ux.ibm.com>,
 Andrea Arcangeli <aarcange@...hat.com>, kvm@...r.kernel.org,
 linux-s390@...r.kernel.org
Subject: Re: [PATCH v2 1/2] mm/userfaultfd: don't place zeropages when
 zeropages are disallowed

On 11.04.24 14:26, Alexander Gordeev wrote:
> On Wed, Mar 27, 2024 at 06:17:36PM +0100, David Hildenbrand wrote:
> 
> Hi David,
> ...
>>   static int mfill_atomic_pte_zeropage(pmd_t *dst_pmd,
>>   				     struct vm_area_struct *dst_vma,
>>   				     unsigned long dst_addr)
>> @@ -324,6 +355,9 @@ static int mfill_atomic_pte_zeropage(pmd_t *dst_pmd,
>>   	spinlock_t *ptl;
>>   	int ret;
>>   
>> +	if (mm_forbids_zeropage(dst_vma->mm))
> 
> I assume, you were going to pass dst_vma->vm_mm here?
> This patch does not compile otherwise.

Ah, I compiled it only on x86, where the parameter is ignored ... and 
for testing the code path I forced mm_forbids_zeropage to be 1 on x86.

Yes, this must be dst_vma->vm_mm.

Thanks!

-- 
Cheers,

David / dhildenb