lkml.org 
[lkml]   [2022]   [Apr]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] arm64: cputype: Avoid overflow using MIDR_IMPLEMENTOR_MASK
Date
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>
---
Should we also add a U suffix to ARM_CPU_IMP_* macros that are also shifted
by MIDR_IMPLEMENTOR_SHIFT? None of them has bit 7 set but we could take some
precaution steps.
---
arch/arm64/include/asm/cputype.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index ff8f4511df71..92331c07c2d1 100644
--- 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)

--
2.25.1
\
 
 \ /
  Last update: 2022-04-26 09:09    [W:0.050 / U:0.976 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site