[RFC][PATCH] arch: sh: use sign_extend64() for sign extension

[Martin Kepplinger]

Signed-off-by: Martin Kepplinger <martink@xxxxxxxxx>
---
 arch/sh/kernel/traps_64.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/sh/kernel/traps_64.c b/arch/sh/kernel/traps_64.c
index 112ea11..4e04261 100644
--- a/arch/sh/kernel/traps_64.c
+++ b/arch/sh/kernel/traps_64.c
@@ -25,6 +25,7 @@
 #include <linux/sysctl.h>
 #include <linux/module.h>
 #include <linux/perf_event.h>
+#include <linux/bitops.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 #include <asm/alignment.h>
@@ -101,7 +102,7 @@ static int generate_and_check_address(struct pt_regs *regs,
 	if (displacement_not_indexed) {
 		__s64 displacement;
 		displacement = (opcode >> 10) & 0x3ff;
-		displacement = ((displacement << 54) >> 54); /* sign extend */
+		displacement = sign_extend64(displacement, 9);
 		addr = (__u64)((__s64)base_address + (displacement << width_shift));
 	} else {
 		__u64 offset;
-- 
2.1.4

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