arm64: cputype: Avoid overflow using MIDR_IMPLEMENTOR_MASK

Value of macro MIDR_IMPLEMENTOR_MASK exceeds the range of integer
and can lead to overflow. Currently there is no issue as it is used
in expressions implicitly casting it to u32. To avoid possible
problems, fix the macro.

Signed-off-by: Michal Orzel <michal.orzel@arm.com>
Link: https://lore.kernel.org/r/20220426070603.56031-1-michal.orzel@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index ff8f4511df71f73d671bbb57449e57ed94f3e7d9..92331c07c2d12fb64bb8acd80e7062636bc7564d 100644 (file)
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -36,7 +36,7 @@
 #define MIDR_VARIANT(midr)     \
        (((midr) & MIDR_VARIANT_MASK) >> MIDR_VARIANT_SHIFT)
 #define MIDR_IMPLEMENTOR_SHIFT 24
-#define MIDR_IMPLEMENTOR_MASK  (0xff << MIDR_IMPLEMENTOR_SHIFT)
+#define MIDR_IMPLEMENTOR_MASK  (0xffU << MIDR_IMPLEMENTOR_SHIFT)
 #define MIDR_IMPLEMENTOR(midr) \
        (((midr) & MIDR_IMPLEMENTOR_MASK) >> MIDR_IMPLEMENTOR_SHIFT)