Skip to contentSkip to conversation

regmap: shift wrapping bugs in 64 bit code

PATCH New Dan Carpenter 1 participant 1 message Dec 12, 2015

Subsystems (3)
Kernel janitors Driver core Register map abstraction
lore
Share & tools
lore

Dan Carpenter

author
#0 lore raw

PATCH 1/2 regmap: shift wrapping bugs in 64 bit code

We should cast these to 64bit so that we don't truncate away the high bits.

Fixes afcc00b91f18 ('regmap: add 64-bit mode support')
Signed-off-by Dan Carpenter <[email protected]>

---
Not tested.

drivers/base/regmap/regmap.c +3 -3
index 1791180..2d4cc70 100644
@@ -250,20 +250,20 @@ static void regmap_format_64_be(void *buf, unsigned int val, unsigned int shift)
 {
 	__be64 *b = buf;
 
-	b[0] = cpu_to_be64(val << shift);
+	b[0] = cpu_to_be64((u64)val << shift);
 }
 
 static void regmap_format_64_le(void *buf, unsigned int val, unsigned int shift)
 {
 	__le64 *b = buf;
 
-	b[0] = cpu_to_le64(val << shift);
+	b[0] = cpu_to_le64((u64)val << shift);
 }
 
 static void regmap_format_64_native(void *buf, unsigned int val,
 				    unsigned int shift)
 {
-	*(u64 *)buf = val << shift;
+	*(u64 *)buf = (u64)val << shift;
 }
 #endif