mm: update ptep_modify_prot_commit to take old pte value as arg

Architectures like ppc64 require to do a conditional tlb flush based on
the old and new value of pte.  Enable that by passing old pte value as
the arg.

Link: http://lkml.kernel.org/r/20190116085035.29729-3-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 5 insertions, 3 deletions

diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 9c2ef731dd5f..beccb0b1d57c 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -948,10 +948,12 @@ static inline void clear_soft_dirty(struct vm_area_struct *vma,
         pte_t ptent = *pte;
 
         if (pte_present(ptent)) {
-                ptent = ptep_modify_prot_start(vma, addr, pte);
-                ptent = pte_wrprotect(ptent);
+                pte_t old_pte;
+
+                old_pte = ptep_modify_prot_start(vma, addr, pte);
+                ptent = pte_wrprotect(old_pte);
                 ptent = pte_clear_soft_dirty(ptent);
-                ptep_modify_prot_commit(vma, addr, pte, ptent);
+                ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
         } else if (is_swap_pte(ptent)) {
                 ptent = pte_swp_clear_soft_dirty(ptent);
                 set_pte_at(vma->vm_mm, addr, pte, ptent);