Re: [PATCH v9 02/10] mm: Non-pmd-mappable, large folios for folio_add_new_anon_rmap()

From: Ryan Roberts <ryan.roberts@arm.com>
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
Subject: Re: [PATCH v9 02/10] mm: Non-pmd-mappable, large folios for folio_add_new_anon_rmap()
Date: Wed, 24 Jan 2024 12:42:04 +0000	[thread overview]
Message-ID: <e7a21ef8-6b72-46da-9a59-7e33394465f3@arm.com> (raw)
In-Reply-To: <yt9dcytqx6dv.fsf@linux.ibm.com>

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!