[PATCH 5.5 384/399] microblaze: Prevent the overflow of the start

Greg Kroah-Hartman
2020-02-21T08:00:24Z

From: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>

[ Upstream commit 061d2c1d593076424c910cb1b64ecdb5c9a6923f ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 0bde47e4fa694..dcba53803fa5f 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)

--
2.20.1