From 9ce8853b4a735c8115f55ac0e9c2b27a4c8f80b5 Mon Sep 17 00:00:00 2001
From: Bharata B Rao <bharata@linux.ibm.com>
Date: Thu, 9 Jul 2020 18:49:23 +0530
Subject: [PATCH] powerpc/mm/radix: Free PUD table when freeing pagetable

References: bsc#1065729
Patch-mainline: v5.9-rc1
Git-commit: 9ce8853b4a735c8115f55ac0e9c2b27a4c8f80b5

remove_pagetable() isn't freeing PUD table. This causes memory
leak during memory unplug. Fix this.

Fixes: 4b5d62ca17a1 ("powerpc/mm: add radix__remove_section_mapping()")
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200709131925.922266-3-aneesh.kumar@linux.ibm.com
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 arch/powerpc/mm/pgtable-radix.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -707,6 +707,21 @@ static void free_pmd_table(pmd_t *pmd_start, pud_t *pud)
 	pud_clear(pud);
 }
 
+static void free_pud_table(pud_t *pud_start, pgd_t *pgd)
+{
+	pud_t *pud;
+	int i;
+
+	for (i = 0; i < PTRS_PER_PUD; i++) {
+		pud = pud_start + i;
+		if (!pud_none(*pud))
+			return;
+	}
+
+	pud_free(&init_mm, pud_start);
+	pgd_clear(pgd);
+}
+
 struct change_mapping_params {
 	pte_t *pte;
 	unsigned long start;
@@ -881,6 +896,7 @@ static void __meminit remove_pagetable(unsigned long start, unsigned long end)
 
 		pud_base = (pud_t *)pgd_page_vaddr(*pgd);
 		remove_pud_table(pud_base, addr, next);
+		free_pud_table(pud_base, pgd);
 	}
 
 	spin_unlock(&init_mm.page_table_lock);
-- 
2.31.1