[PATCH] kho: fix child node parsing for debugfs in/sub_fdts

[Pratyush Yadav]

On Sat, Mar 14 2026, Andrew Morton wrote:

> On Fri, 13 Mar 2026 10:02:06 +0000 Pratyush Yadav <pratyush at kernel.org> wrote:
>
>> On Mon, Mar 09 2026, ranxiaokai627 at 163.com wrote:
>> 
>> > From: Ran Xiaokai <ran.xiaokai at zte.com.cn>
>> >
>> > Commit e0c1731f5d57 ("kho: adopt radix tree for preserved memory tracking")
>> > changed KHO_FDT_SUB_TREE_PROP_NAME from "fdt" to "preserved-data". However,
>> > kho debugfs code still hard-coded the "fdt" string when parsing the
>> > device tree, causing the debugfs node /debugfs/kho/in/sub_fdts/
>> > fail to parse child nodes correctly.
>> >
>> > Fix this by including the header file and using KHO_FDT_SUB_TREE_PROP_NAME
>> > instead of the hard-coded string.
>> >
>> > Fixes: e0c1731f5d57 ("kho: adopt radix tree for preserved memory tracking")
>> > Signed-off-by: Ran Xiaokai <ran.xiaokai at zte.com.cn>
>> 
>> Breno's patch [0] also fixes this, but I'd rather have this go through
>> hotfixes and get backported to stable, and Breno's series to build on
>> top of this.
>> 
>> [0] https://lore.kernel.org/linux-mm/20260309-kho-v8-4-c3abcf4ac750@debian.org/
>
> Confused.  This patch (kho: fix child node parsing for debugfs
> in/sub_fdts) fixes the mm-unstable patch "kho: adopt radix tree for
> preserved memory tracking".
>
> So what are you suggesting be added to -stable?
>
> (Please lay it all out very clearly, idenfifying patches by name!)

Sorry, my bad for causing the confusion. I thought the radix tree
patches ("kho: adopt radix tree for preserved memory tracking") already
landed in mainline, but I went and checked and it seems that they
haven't. They are still in mm-unstable. So we should just meld this
patch ("kho: fix child node parsing for debugfs in/sub_fdts") into
("kho: adopt radix tree for preserved memory tracking").

There is nothing that needs to be added to -stable, and there is nothing
that needs to go to hotfixes.

Breno's patch ("kho: fix kho_in_debugfs_init() to handle non-FDT blobs")
also fixes this bug, but then also adds some other changes with it. So
Breno's patch will cause conflicts once applied on top of this patch,
but they should be simple enough to resolve I think.

-- 
Regards,
Pratyush Yadav