Re: + mm-kasan-switch-slub-to-stackdepot-enable-memory-quarantine-for-slub-fix-2.patch added to -mm tree

[Alexander Potapenko]

On Thu, Jul 21, 2016 at 10:48 AM, Andrey Ryabinin
<aryabinin@xxxxxxxxxxxxx> wrote:
>
>
> On 07/20/2016 09:43 PM, akpm@xxxxxxxxxxxxxxxxxxxx wrote:
>>
>> The patch titled
>>      Subject: mm-kasan-switch-slub-to-stackdepot-enable-memory-quarantine-for-slub-fix
>> has been added to the -mm tree.  Its filename is
>>      mm-kasan-switch-slub-to-stackdepot-enable-memory-quarantine-for-slub-fix-2.patch
>>
>> This patch should soon appear at
>>     http://ozlabs.org/~akpm/mmots/broken-out/mm-kasan-switch-slub-to-stackdepot-enable-memory-quarantine-for-slub-fix-2.patch
>> and later at
>>     http://ozlabs.org/~akpm/mmotm/broken-out/mm-kasan-switch-slub-to-stackdepot-enable-memory-quarantine-for-slub-fix-2.patch
>>
>> Before you just go and hit "reply", please:
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>>    c) Ideally: find the original patch on the mailing list and do a
>>       reply-to-all to that, adding suitable additional cc's
>>
>> *** Remember to use Documentation/SubmitChecklist when testing your code ***
>>
>> The -mm tree is included into linux-next and is updated
>> there every 3-4 working days
>>
>> ------------------------------------------------------
>> From: "Kirill A. Shutemov" <kirill@xxxxxxxxxxxxx>
>> Subject: mm-kasan-switch-slub-to-stackdepot-enable-memory-quarantine-for-slub-fix
>>
>
> This should be a separate patch. Stackdepot was added in cd11016e5f5212c13c0cec7384a525edc93b4921
> which is in v4.6.
Andrey, do you think we need this patch?
I've posted the link to
http://article.gmane.org/gmane.linux.kernel/2266971 in the discussion,
and my patch seems to have fixed the problem.
Adding __GFP_NOWARN will mask further problems of the similar nature,
so I think we'd better avoid it.

>> use __GFP_NOWARN for stack
>>
>> Link: http://lkml.kernel.org/r/20160720151905.GB19146@xxxxxxxxxxxxxxxxxx
>> Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
>> Cc: Alexander Potapenko <glider@xxxxxxxxxx>
>> Cc: Michal Hocko <mhocko@xxxxxxx>
>> Cc: Rik van Riel <riel@xxxxxxxxxx>
>> Cc: David Rientjes <rientjes@xxxxxxxxxx>
>> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
>> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>> ---
>>
>>  lib/stackdepot.c |    1 +
>>  1 file changed, 1 insertion(+)
>>
>> diff -puN lib/stackdepot.c~mm-kasan-switch-slub-to-stackdepot-enable-memory-quarantine-for-slub-fix-2 lib/stackdepot.c
>> --- a/lib/stackdepot.c~mm-kasan-switch-slub-to-stackdepot-enable-memory-quarantine-for-slub-fix-2
>> +++ a/lib/stackdepot.c
>> @@ -242,6 +242,7 @@ depot_stack_handle_t depot_save_stack(st
>>                */
>>               alloc_flags &= ~GFP_ZONEMASK;
>>               alloc_flags &= (GFP_ATOMIC | GFP_KERNEL);
>> +             alloc_flags |= __GFP_NOWARN;
>>               page = alloc_pages(alloc_flags, STACK_ALLOC_ORDER);
>>               if (page)
>>                       prealloc = page_address(page);
>> _
>>
>> Patches currently in -mm which might be from kirill@xxxxxxxxxxxxx are
>>
>> mm-kasan-switch-slub-to-stackdepot-enable-memory-quarantine-for-slub-fix-2.patch
>>



-- 
Alexander Potapenko
Software Engineer

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