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

Message ID ab2581eb-daa6-894e-4aa6-97c81de3b8c@google.com (mailing list archive)
State Not Applicable
Headers show
Series arch: allow pte_offset_map[_lock]() to fail | expand

Commit Message

Hugh Dickins June 8, 2023, 7:37 p.m. UTC 
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@google.com>
---
 arch/xtensa/mm/tlb.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
diff mbox series

Patch

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 {