[PATCH] target/arm/tcg: fix potential integer overflow in iwmmxt_macuw()

[gerben@altlinux.org]

From: Denis Rastyogin <gerben@altlinux.org>

The function iwmmxt_macuw() could potentially cause an integer
overflow when summing up four 32-bit multiplications.
This occurs because the intermediate results may exceed the 32-bit
range before being cast to uint64_t. The fix ensures each
multiplication is explicitly cast to uint64_t prior to summation,
preventing potential issues and ensuring correctness.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Denis Sergeev <zeff@altlinux.org>
Signed-off-by: Denis Rastyogin <gerben@altlinux.org>
---
 target/arm/tcg/iwmmxt_helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/arm/tcg/iwmmxt_helper.c b/target/arm/tcg/iwmmxt_helper.c
index 610b1b2103..19c709655e 100644
--- a/target/arm/tcg/iwmmxt_helper.c
+++ b/target/arm/tcg/iwmmxt_helper.c
@@ -140,7 +140,7 @@ uint64_t HELPER(iwmmxt_macsw)(uint64_t a, uint64_t b)
 
 uint64_t HELPER(iwmmxt_macuw)(uint64_t a, uint64_t b)
 {
-#define MACU(SHR) ( \
+#define MACU(SHR) (uint64_t)( \
         (uint32_t) ((a >> SHR) & 0xffff) * \
         (uint32_t) ((b >> SHR) & 0xffff))
     return MACU(0) + MACU(16) + MACU(32) + MACU(48);
-- 
2.42.2