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

Ryan Roberts
2024-01-24T12:42:10Z

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!