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From:   Michal Simek <michal.simek@xilinx.com>
To:     linux-kernel@vger.kernel.org, monstr@monstr.eu,
        michal.simek@xilinx.com, git@xilinx.com
Cc:     Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Subject: [PATCH] microblaze: Prevent the overflow of the start
Date:   Tue, 14 Jan 2020 13:34:17 +0100
Message-Id: <e24752dd9ea739c86bca9cfe79f7f29b0afa0182.1579005255.git.michal.simek@xilinx.com>
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From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

In case the start + cache size is more than the max int the
start overflows.
Prevent the same.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
---

 arch/microblaze/kernel/cpu/cache.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/microblaze/kernel/cpu/cache.c b/arch/microblaze/kernel/cpu/cache.c
index 0bde47e4fa69..dcba53803fa5 100644
--- a/arch/microblaze/kernel/cpu/cache.c
+++ b/arch/microblaze/kernel/cpu/cache.c
@@ -92,7 +92,8 @@ static inline void __disable_dcache_nomsr(void)
 #define CACHE_LOOP_LIMITS(start, end, cache_line_length, cache_size)	\
 do {									\
 	int align = ~(cache_line_length - 1);				\
-	end = min(start + cache_size, end);				\
+	if (start <  UINT_MAX - cache_size)				\
+		end = min(start + cache_size, end);			\
 	start &= align;							\
 } while (0)
 
-- 
2.24.0