From: Ralf Baechle <ralf@linux-mips.org>
Date: Tue, 18 Nov 2014 17:47:13 +0000 (+0100)
Subject: MIPS: Zero variable read by get_user / __get_user in case of an error.
X-Git-Tag: v3.16.43~6
X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4c125b48deacb51dbe5618ba5c1cfec9bcc41e6e;p=linux

MIPS: Zero variable read by get_user / __get_user in case of an error.

commit 640465bda58c7078725201be7430c31a349121e9 upstream.

This wasn't happening in all cases.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
---

diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index cb4a3ee31983..a752de97840f 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -302,7 +302,8 @@ do {									\
 			__get_kernel_common((x), size, __gu_ptr);	\
 		else							\
 			__get_user_common((x), size, __gu_ptr);		\
-	}								\
+	} else								\
+		(x) = 0;						\
 									\
 	__gu_err;							\
 })
@@ -317,6 +318,7 @@ do {									\
 	"	.insn						\n"	\
 	"	.section .fixup,\"ax\"				\n"	\
 	"3:	li	%0, %4					\n"	\
+	"	move	%1, $0					\n"	\
 	"	j	2b					\n"	\
 	"	.previous					\n"	\
 	"	.section __ex_table,\"a\"			\n"	\
@@ -631,6 +633,7 @@ do {									\
 	"	.insn						\n"	\
 	"	.section .fixup,\"ax\"				\n"	\
 	"3:	li	%0, %4					\n"	\
+	"	move	%1, $0					\n"	\
 	"	j	2b					\n"	\
 	"	.previous					\n"	\
 	"	.section __ex_table,\"a\"			\n"	\