Add a few simple error checks to tlb dumper.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 14 insertions, 11 deletions

diff --git a/arch/mips/lib-32/dump_tlb.c b/arch/mips/lib-32/dump_tlb.c
index 9373a7740125..46519f4331eb 100644
--- a/arch/mips/lib-32/dump_tlb.c
+++ b/arch/mips/lib-32/dump_tlb.c
@@ -160,24 +160,27 @@ void dump_list_process(struct task_struct *t, void *address)
 
         if (addr > KSEG0)
                 page_dir = pgd_offset_k(0);
-        else
+        else if (t->mm) {
                 page_dir = pgd_offset(t->mm, 0);
-        printk("page_dir == %08x\n", (unsigned int) page_dir);
+                printk("page_dir == %08x\n", (unsigned int) page_dir);
+        } else
+                printk("Current thread has no mm\n");
 
         if (addr > KSEG0)
                 pgd = pgd_offset_k(addr);
-        else
+        else if (t->mm) {
                 pgd = pgd_offset(t->mm, addr);
-        printk("pgd == %08x, ", (unsigned int) pgd);
+                printk("pgd == %08x, ", (unsigned int) pgd);
+                pud = pud_offset(pgd, addr);
+                printk("pud == %08x, ", (unsigned int) pud);
 
-        pud = pud_offset(pgd, addr);
-        printk("pud == %08x, ", (unsigned int) pud);
-
-        pmd = pmd_offset(pud, addr);
-        printk("pmd == %08x, ", (unsigned int) pmd);
+                pmd = pmd_offset(pud, addr);
+                printk("pmd == %08x, ", (unsigned int) pmd);
 
-        pte = pte_offset(pmd, addr);
-        printk("pte == %08x, ", (unsigned int) pte);
+                pte = pte_offset(pmd, addr);
+                printk("pte == %08x, ", (unsigned int) pte);
+        } else
+                printk("Current thread has no mm\n");
 
         page = *pte;
 #ifdef CONFIG_64BIT_PHYS_ADDR