Add a few simple error checks to tlb dumper.

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

diff --git a/arch/mips/lib-32/dump_tlb.c b/arch/mips/lib-32/dump_tlb.c
index 9373a77..46519f4 100644 (file)
--- 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