From: Anfei <anfei.zhou@gmail.com>
Date: Tue, 8 Jun 2010 14:16:49 +0000 (+0100)
Subject: ARM: 6166/1: Proper prefetch abort handling on pre-ARMv6
X-Git-Tag: firefly_0821_release~9833^2~1528^2~2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=5e27fb78df95e027723af2c90ecc9b4527ae59e9;p=firefly-linux-kernel-4.4.55.git

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>
---

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);
 
 	/*