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

From: Muchun Song

Date: Thu Oct 08 2026 - 03:32:15 EST


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_pagetable() 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@xxxxxxxxxxxxxxx
Assisted-by: LLM
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
---
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 429a0b015ec1..62077539ee78 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -1540,10 +1540,7 @@ 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_pagetable(page);
p4d_clear(p4d);
}

--
2.54.0