In rare transient cases, not yet made possible, pte_offset_map() and
pte_offset_map_lock() may not find a page table: handle appropriately.

Signed-off-by: Hugh Dickins <hu...@google.com>
---
 arch/sparc/kernel/signal32.c | 2 ++
 arch/sparc/mm/fault_64.c     | 3 +++
 arch/sparc/mm/tlb.c          | 2 ++
 3 files changed, 7 insertions(+)

diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c
index dad38960d1a8..ca450c7bc53f 100644
--- a/arch/sparc/kernel/signal32.c
+++ b/arch/sparc/kernel/signal32.c
@@ -328,6 +328,8 @@ static void flush_signal_insns(unsigned long address)
                goto out_irqs_on;
 
        ptep = pte_offset_map(pmdp, address);
+       if (!ptep)
+               goto out_irqs_on;
        pte = *ptep;
        if (!pte_present(pte))
                goto out_unmap;
diff --git a/arch/sparc/mm/fault_64.c b/arch/sparc/mm/fault_64.c
index d91305de694c..d8a407fbe350 100644
--- a/arch/sparc/mm/fault_64.c
+++ b/arch/sparc/mm/fault_64.c
@@ -99,6 +99,7 @@ static unsigned int get_user_insn(unsigned long tpc)
        local_irq_disable();
 
        pmdp = pmd_offset(pudp, tpc);
+again:
        if (pmd_none(*pmdp) || unlikely(pmd_bad(*pmdp)))
                goto out_irq_enable;
 
@@ -115,6 +116,8 @@ static unsigned int get_user_insn(unsigned long tpc)
 #endif
        {
                ptep = pte_offset_map(pmdp, tpc);
+               if (!ptep)
+                       goto again;
                pte = *ptep;
                if (pte_present(pte)) {
                        pa  = (pte_pfn(pte) << PAGE_SHIFT);
diff --git a/arch/sparc/mm/tlb.c b/arch/sparc/mm/tlb.c
index 9a725547578e..7ecf8556947a 100644
--- a/arch/sparc/mm/tlb.c
+++ b/arch/sparc/mm/tlb.c
@@ -149,6 +149,8 @@ static void tlb_batch_pmd_scan(struct mm_struct *mm, 
unsigned long vaddr,
        pte_t *pte;
 
        pte = pte_offset_map(&pmd, vaddr);
+       if (!pte)
+               return;
        end = vaddr + HPAGE_SIZE;
        while (vaddr < end) {
                if (pte_val(*pte) & _PAGE_VALID) {
-- 
2.35.3

Reply via email to