Re: [PATCH] s390/mm: Add missing vm_start <= addr check to do_secure_storage_access()

[Christian Borntraeger <borntraeger@linux.ibm.com>]

Am 24.07.26 um 14:48 schrieb Heiko Carstens:
> On Fri, Jul 24, 2026 at 02:09:32PM +0200, Alexander Gordeev wrote:
>> On Fri, Jul 17, 2026 at 03:14:07PM +0200, Heiko Carstens wrote:
>>> diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
>>> index 028aeb9c48d6..d6c58d78edc5 100644
>>> --- a/arch/s390/mm/fault.c
>>> +++ b/arch/s390/mm/fault.c
>>> @@ -456,10 +456,9 @@ void do_secure_storage_access(struct pt_regs *regs)
>>>   		if (faulthandler_disabled())
>>>   			return handle_fault_error_nolock(regs, 0);
>>>   		mm = current->mm;
>>> -		mmap_read_lock(mm);
>>> -		vma = find_vma(mm, addr);
>>> +		vma = lock_mm_and_find_vma(mm, addr, regs);
>>>   		if (!vma)
>>> -			return handle_fault_error(regs, SEGV_MAPERR);
>>> +			return handle_fault_error_nolock(regs, SEGV_MAPERR);
>>>   		folio = folio_walk_start(&fw, vma, addr, 0);
>>>   		if (!folio) {
>>>   			mmap_read_unlock(mm);
>>
>> The Sashiko feedback looks like a false positive to me.
>>
>> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
> 
> This has been integrated into the "[PATCH v4 0/8] s390: Reintroduce
> support for DCACHE_WORD_ACCESS" series. First I thought of keeping
> things separate, but decided then to address all of Sashiko reports
> and make the code look quite similar to do_exception().
> 
> So v4 is the only series that matters, everything else can be ignored.
> 
> What is still missing is kmemleak handling for which Christian posted
> a patch, but that appears to be incomplete. Or least my thinking is
> that there will be a subsequent patch.
> 
> Christian?

Yes, its on my todo list to extend the initial patch to also take care of
the other storage areas. Still doing other things first.....