Subject: [PATCH v1 3/3] powerpc/mm/radix: Free PUD table when freeing pagetable

From: Bharata B Rao <[email-masked]>
Date: Tue, 23 Jun 2020 13:00:17 +0530

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

Signed-off-by: Bharata B Rao <[email-masked]>
---
 arch/powerpc/mm/book3s64/radix_pgtable.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index 58e42393d5e8..8ec2110eaa1a 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -782,6 +782,21 @@ static void free_pmd_table(pmd_t *pmd_start, pud_t *pud)
 	pud_clear(pud);
 }
 
+static void free_pud_table(pud_t *pud_start, p4d_t *p4d)
+{
+	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);
+	p4d_clear(p4d);
+}
+
 struct change_mapping_params {
 	pte_t *pte;
 	unsigned long start;
@@ -956,6 +971,7 @@ static void __meminit remove_pagetable(unsigned long start, unsigned long end)
 
 		pud_base = (pud_t *)p4d_page_vaddr(*p4d);
 		remove_pud_table(pud_base, addr, next);
+		free_pud_table(pud_base, p4d);
 	}
 
 	spin_unlock(&init_mm.page_table_lock);
-- 
2.21.3