Re: [PATCH v2 0/4] kasan: Fix ordering between MTE tag colouring and page->flags

["Qun-wei Lin (林群崴)" <Qun-wei.Lin@mediatek.com>]

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On Fri, 2023-02-03 at 18:51 +0100, Andrey Konovalov wrote:
> On Fri, Feb 3, 2023 at 4:41 AM Kuan-Ying Lee (李冠穎)
> <Kuan-Ying.Lee@mediatek.com> wrote:
> > 
> > > Hi Kuan-Ying,
> > > 
> > > There recently was a similar crash due to incorrectly implemented
> > > sampling.
> > > 
> > > Do you have the following patch in your tree?
> > > 
> > > 
> > 
> > 
https://urldefense.com/v3/__https://android.googlesource.com/kernel/common/*/9f7f5a25f335e6e1484695da9180281a728db7e2__;Kw!!CTRNKA9wMg0ARbw!hUjRlXirPMSusdIWe0RIPt0PNqIHYDCJyd7GSd4o-TgLMP0CKRUkjElH-jcvtaz42-sgE2U58964rCCbuNTJE5Jx$
> > > 
> > > 
> > > If not, please sync your 6.1 tree with the Android common kernel.
> > > Hopefully this will fix the issue.
> > > 
> > > Thanks!
> > 
> > Hi Andrey,
> > 
> > Thanks for your advice.
> > 
> > I saw this patch is to fix ("kasan: allow sampling page_alloc
> > allocations for HW_TAGS").
> > 
> > But our 6.1 tree doesn't have following two commits now.
> > ("FROMGIT: kasan: allow sampling page_alloc allocations for
> > HW_TAGS")
> > (FROMLIST: kasan: reset page tags properly with sampling)
> 
> Hi Kuan-Ying,
> 

Hi Andrey,
I'll stand in for Kuan-Ying as he's out of office.
Thanks for your help!

> Just to clarify: these two patches were applied twice: once here on
> Jan 13:
> 
> 
https://urldefense.com/v3/__https://android.googlesource.com/kernel/common/*/a2a9e34d164e90fc08d35fd097a164b9101d72ef__;Kw!!CTRNKA9wMg0ARbw!kE1XiSmunRcQb9rTpKGkFc1EFJA57qr1cj7v9EZAjUBzXcSzMl-ofCI2mdtEQsxn3J4n7Lkgxb0_G745_3oO-3k$ 
>  
> 
https://urldefense.com/v3/__https://android.googlesource.com/kernel/common/*/435e2a6a6c8ba8d0eb55f9aaade53e7a3957322b__;Kw!!CTRNKA9wMg0ARbw!kE1XiSmunRcQb9rTpKGkFc1EFJA57qr1cj7v9EZAjUBzXcSzMl-ofCI2mdtEQsxn3J4n7Lkgxb0_G745sDEOYWY$ 
>  
> 

Our codebase does not contain these two patches.

> but then reverted here on Jan 20:
> 
> 
https://urldefense.com/v3/__https://android.googlesource.com/kernel/common/*/5503dbe454478fe54b9cac3fc52d4477f52efdc9__;Kw!!CTRNKA9wMg0ARbw!kE1XiSmunRcQb9rTpKGkFc1EFJA57qr1cj7v9EZAjUBzXcSzMl-ofCI2mdtEQsxn3J4n7Lkgxb0_G745Bl77dFY$ 
>  
> 
https://urldefense.com/v3/__https://android.googlesource.com/kernel/common/*/4573a3cf7e18735a477845426238d46d96426bb6__;Kw!!CTRNKA9wMg0ARbw!kE1XiSmunRcQb9rTpKGkFc1EFJA57qr1cj7v9EZAjUBzXcSzMl-ofCI2mdtEQsxn3J4n7Lkgxb0_G745K-J8O-w$ 
>  
> 
> And then once again via the link I sent before together with a fix on
> Jan 25.
> 
> It might be that you still have to former two patches in your tree if
> you synced it before the revert.
> 
> However, if this is not the case:
> 
> Which 6.1 commit is your tree based on?


https://android.googlesource.com/kernel/common/+/53b3a7721b7aec74d8fa2ee55c2480044cc7c1b8
(53b3a77 Merge 6.1.1 into android14-6.1) is the latest commit in our
tree.

> Do you have any private MTE-related changes in the kernel?

No, all the MTE-related code is the same as Android Common Kernel.

> Do you have userspace MTE enabled?

Yes, we have enabled MTE for both EL1 and EL0.

> 
> Thanks!