[PATCH v2 23/23] xtensa: add pte_unmap() to balance pte_offset_map()

From: Hugh Dickins
Date: Thu Jun 08 2023 - 15:38:03 EST


To keep balance in future, remember to pte_unmap() after a successful
pte_offset_map(). And act as if get_pte_for_vaddr() really needs a map
there, to read the pteval before "unmapping", to be sure page table is
not removed.

Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
---
arch/xtensa/mm/tlb.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/xtensa/mm/tlb.c b/arch/xtensa/mm/tlb.c
index 27a477dae232..0a11fc5f185b 100644
--- a/arch/xtensa/mm/tlb.c
+++ b/arch/xtensa/mm/tlb.c
@@ -179,6 +179,7 @@ static unsigned get_pte_for_vaddr(unsigned vaddr)
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
+ unsigned int pteval;

if (!mm)
mm = task->active_mm;
@@ -197,7 +198,9 @@ static unsigned get_pte_for_vaddr(unsigned vaddr)
pte = pte_offset_map(pmd, vaddr);
if (!pte)
return 0;
- return pte_val(*pte);
+ pteval = pte_val(*pte);
+ pte_unmap(pte);
+ return pteval;
}

enum {
--
2.35.3