From 90eed7d87b748f9c0d11b9bad64a4c41e31b78c4 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Tue, 24 Jul 2012 13:15:54 +0900 Subject: [PATCH] sh: Fix up recursive fault in oops with unset TTB. Presently the oops code looks for the pgd either from the mm context or the cached TTB value. There are presently cases where the TTB can be unset or otherwise cleared by hardware, which we weren't handling, resulting in recursive faults on the NULL pgd. In these cases we can simply reload from swapper_pg_dir and continue on as normal. Cc: stable@vger.kernel.org Signed-off-by: Paul Mundt --- arch/sh/mm/fault.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/sh/mm/fault.c b/arch/sh/mm/fault.c index 1fc25d85e515..3bdc1ad9a341 100644 --- a/arch/sh/mm/fault.c +++ b/arch/sh/mm/fault.c @@ -58,11 +58,15 @@ static void show_pte(struct mm_struct *mm, unsigned long addr) { pgd_t *pgd; - if (mm) + if (mm) { pgd = mm->pgd; - else + } else { pgd = get_TTB(); + if (unlikely(!pgd)) + pgd = swapper_pg_dir; + } + printk(KERN_ALERT "pgd = %p\n", pgd); pgd += pgd_index(addr); printk(KERN_ALERT "[%08lx] *pgd=%0*Lx", addr, -- 2.30.2