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

[Andrew Morton]

On Tue, 17 Mar 2026 09:09:36 +0000 Pratyush Yadav <pratyush at kernel.org> wrote:

> 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").

OK, that's how we presently have things:

kho-adopt-radix-tree-for-preserved-memory-tracking.patch
kho-adopt-radix-tree-for-preserved-memory-tracking-fix.patch <- "kho: fix child node..."
kho-remove-finalize-state-and-clients.patch

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

Great.

> 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.

OK, let's deal with that when the time comes.