Re: FAILED: patch "[PATCH] memblock: use kfree() to release kmalloced memblock regions" failed to apply to 5.15-stable tree

[Mike Rapoport <rppt@linux.ibm.com>]

On Mon, Feb 28, 2022 at 09:58:43AM +0100, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 5.15-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

This version applies to 5.15 and should apply to older version as well.

From d4895990ebea634715d2dcf54121c5ae5a6612bc Mon Sep 17 00:00:00 2001
From: Miaohe Lin <linmiaohe@huawei.com>
Date: Thu, 17 Feb 2022 22:53:27 +0800
Subject: [PATCH] memblock: use kfree() to release kmalloced memblock regions

memblock.{reserved,memory}.regions may be allocated using kmalloc() in
memblock_double_array(). Use kfree() to release these kmalloced regions
indicated by memblock_{reserved,memory}_in_slab.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Fixes: 3010f876500f ("mm: discard memblock data later")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
---
 mm/memblock.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/mm/memblock.c b/mm/memblock.c
index 5096500b2647..2b7397781c99 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -366,14 +366,20 @@ void __init memblock_discard(void)
 		addr = __pa(memblock.reserved.regions);
 		size = PAGE_ALIGN(sizeof(struct memblock_region) *
 				  memblock.reserved.max);
-		__memblock_free_late(addr, size);
+		if (memblock_reserved_in_slab)
+			kfree(memblock.reserved.regions);
+		else
+			__memblock_free_late(addr, size);
 	}
 
 	if (memblock.memory.regions != memblock_memory_init_regions) {
 		addr = __pa(memblock.memory.regions);
 		size = PAGE_ALIGN(sizeof(struct memblock_region) *
 				  memblock.memory.max);
-		__memblock_free_late(addr, size);
+		if (memblock_memory_in_slab)
+			kfree(memblock.memory.regions);
+		else
+			__memblock_free_late(addr, size);
 	}
 
 	memblock_memory = NULL;
-- 
2.28.0

> thanks,
> 
> greg k-h

--
Sincerely yours,
Mike.