[PATCH net] net: phy: nxp-c45-tja11xx: fix unsigned long multiplication overflow

From: Radu Pirea (OSS)
Date: Thu Apr 06 2023 - 06:01:10 EST


Any multiplication between GENMASK(31, 0) and a number bigger than 1
will be truncated because of the overflow, if the size of unsigned long
is 32 bits.

Replaced GENMASK with GENMASK_ULL to make sure that multiplication will
be between 64 bits values.

Cc: <stable@xxxxxxxxxxxxxxx> # 5.15+
Fixes: 514def5dd339 ("phy: nxp-c45-tja11xx: add timestamping support")
Signed-off-by: Radu Pirea (OSS) <radu-nicolae.pirea@xxxxxxxxxxx>
---
drivers/net/phy/nxp-c45-tja11xx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/phy/nxp-c45-tja11xx.c b/drivers/net/phy/nxp-c45-tja11xx.c
index 27738d1ae9ea..029875a59ff8 100644
--- a/drivers/net/phy/nxp-c45-tja11xx.c
+++ b/drivers/net/phy/nxp-c45-tja11xx.c
@@ -191,7 +191,7 @@
#define MAX_ID_PS 2260U
#define DEFAULT_ID_PS 2000U

-#define PPM_TO_SUBNS_INC(ppb) div_u64(GENMASK(31, 0) * (ppb) * \
+#define PPM_TO_SUBNS_INC(ppb) div_u64(GENMASK_ULL(31, 0) * (ppb) * \
PTP_CLK_PERIOD_100BT1, NSEC_PER_SEC)

#define NXP_C45_SKB_CB(skb) ((struct nxp_c45_skb_cb *)(skb)->cb)
--
2.34.1