ARM: 6166/1: Proper prefetch abort handling on pre-ARMv6

Instruction faults on pre-ARMv6 CPUs are interpreted as
a 'translation fault', but do_translation_fault doesn't
handle well if user mode trying to run instruction above
TASK_SIZE, and result in the infinite retry of that
instruction.

CC: <stable@kernel.org>
Signed-off-by: Anfei Zhou <anfei.zhou@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/arm/mm/fault.c b/arch/arm/mm/fault.c
index 92f5801f99c1..cbfb2edcf7d1 100644
--- a/arch/arm/mm/fault.c
+++ b/arch/arm/mm/fault.c
@@ -393,6 +393,9 @@ do_translation_fault(unsigned long addr, unsigned int fsr,
         if (addr < TASK_SIZE)
                 return do_page_fault(addr, fsr, regs);
 
+        if (user_mode(regs))
+                goto bad_area;
+
         index = pgd_index(addr);
 
         /*