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Message-ID: <e7a21ef8-6b72-46da-9a59-7e33394465f3@arm.com>
Date: Wed, 24 Jan 2024 12:42:04 +0000
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Subject: Re: [PATCH v9 02/10] mm: Non-pmd-mappable, large folios for
 folio_add_new_anon_rmap()
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To: Sven Schnelle <svens@linux.ibm.com>
Cc: Jiri Olsa <olsajiri@gmail.com>, David Hildenbrand <david@redhat.com>,
 Andrew Morton <akpm@linux-foundation.org>,
 Matthew Wilcox <willy@infradead.org>, Yin Fengwei <fengwei.yin@intel.com>,
 Yu Zhao <yuzhao@google.com>, Catalin Marinas <catalin.marinas@arm.com>,
 Anshuman Khandual <anshuman.khandual@arm.com>, Yang Shi
 <shy828301@gmail.com>, "Huang, Ying" <ying.huang@intel.com>,
 Zi Yan <ziy@nvidia.com>, Luis Chamberlain <mcgrof@kernel.org>,
 Itaru Kitayama <itaru.kitayama@gmail.com>,
 "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
 John Hubbard <jhubbard@nvidia.com>, David Rientjes <rientjes@google.com>,
 Vlastimil Babka <vbabka@suse.cz>, Hugh Dickins <hughd@google.com>,
 Kefeng Wang <wangkefeng.wang@huawei.com>, Barry Song <21cnbao@gmail.com>,
 Alistair Popple <apopple@nvidia.com>, linux-mm@kvack.org,
 linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
 Barry Song <v-songbaohua@oppo.com>, linux-s390@vger.kernel.org
References: <20231207161211.2374093-1-ryan.roberts@arm.com>
 <20231207161211.2374093-3-ryan.roberts@arm.com> <ZaMR2EWN-HvlCfUl@krava>
 <41dc7dff-1ea8-4894-a487-88d46ec2b2d8@redhat.com> <ZaRKMwKJIBmh8-lD@krava>
 <1188e67e-5c04-4bb5-b242-78d92c3fc85c@arm.com>
 <yt9d1qa7x9qv.fsf@linux.ibm.com> <ZbDyLzoIm0GdQzZA@krava>
 <6caaced7-a9d7-4fe4-823a-11b96be83e46@arm.com> <ZbD9YdCmZ3_uTj_k@krava>
 <edfade67-269e-4a49-8db6-40617131e283@arm.com>
 <yt9dcytqx6dv.fsf@linux.ibm.com>
From: Ryan Roberts <ryan.roberts@arm.com>
In-Reply-To: <yt9dcytqx6dv.fsf@linux.ibm.com>
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On 24/01/2024 12:28, Sven Schnelle wrote:
> Hi Ryan,
> 
> Ryan Roberts <ryan.roberts@arm.com> writes:
> 
>>>>>>>>>> I'm hitting this bug (console output below) with adding uprobe
>>>>>>>>>> on simple program like:
>>>>>>>>>>
>>>>>>>>>>    $ cat up.c
>>>>>>>>>>    int main(void)
>>>>>>>>>>    {
>>>>>>>>>>       return 0;
>>>>>>>>>>    }
>>>>>>>>>>
>>>>>>>>>>    # bpftrace -e 'uprobe:/home/jolsa/up:_start {}'
>>>>>>>>>>
>>>>>>>>>>    $ ./up
>>>>>>>>>>
>>>>>>>>>> it's on top of current linus tree master:
>>>>>>>>>>    052d534373b7 Merge tag 'exfat-for-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat
>>>>>>>>>>
>>>>>>>>>> before this patch it seems to work, I can send my .config if needed
>>>>>>>
>>>>>>> Thanks for the bug report!
>>>>>>
>>>>>> I just hit the same bug in our CI, but can't find the fix in -next. Is
>>>>>> this in the queue somewhere?
>>>>>
>>>>> we hit it as well, but I can see the fix in linux-next/master
>>>>>
>>>>>   4c137bc28064 uprobes: use pagesize-aligned virtual address when replacing pages
>>>>
>>>> Yes that's the one. Just to confirm: you are still hitting the VM_BUG_ON despite
>>>> having this change in your kernel? Could you please send over the full bug log?
>>>
>>> ah sorry.. I meant the change fixes the problem for us, it just did not
>>> yet propagate through the merge cycle into bpf trees.. but I can see it
>>> in linux-next tree, so it's probably just matter of time
>>
>> OK great! How about you, Sven? Do you have this change in your kernel? Hopefully
>> it should fix your problem.
> 
> Same here - the fix makes uprobes work again, i just didn't see it in
> torvalds-master and neither in todays linux-next. But Jiri is right,
> it's in linux-next/master. I just missed to find it there. So everything
> should be ok.

Great!