[PATCH v3 3/4] riscv/mm: fix missing destructor for hotplug PUD tables

[Muchun Song <songmuchun@bytedance.com>]

Commit 8472cc4503eb ("riscv: mm: call PUD/P4D ctor in special kernel
pgtable alloc") made alloc_pud_late() run the PUD page-table constructor.
However, free_pud_table() still frees non-reserved PUD tables directly
without decrementing NR_PAGETABLE.

Free PUD tables through the common free_pgtable_page() helper so that
constructor-backed tables run the matching destructor before being
freed.

Fixes: 8472cc4503eb ("riscv: mm: call PUD/P4D ctor in special kernel pgtable alloc")
Cc: stable@vger.kernel.org
Assisted-by: LLM
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Björn Töpel <bjorn@kernel.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
---
v3:
- Collect Reviewed-by from Björn Töpel and Kevin Brodsky

v2:
- Collect Acked-by from David Hildenbrand
---
 arch/riscv/mm/init.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index e111d25e18e1..f35fe4cda89c 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -1537,10 +1537,7 @@ static void __meminit free_pud_table(pud_t *pud_start, p4d_t *p4d)
 			return;
 	}
 
-	if (PageReserved(page))
-		free_reserved_page(page);
-	else
-		__free_pages(page, 0);
+	free_pgtable_page(page);
 	p4d_clear(p4d);
 }
 
-- 
2.54.0