From 0e2bec77ea62895416600c90588f593516572bca Mon Sep 17 00:00:00 2001 From: Florian Fainelli Date: Mon, 21 Sep 2026 15:00:17 -0700 Subject: [PATCH] net: bcmgenet: fix 64-bit RTNL stats reading in ethtool on 32-bit systems When bcmgenet was converted to 64-bit statistics, STAT_RTNL members were switched to point into struct rtnl_link_stats64, whose fields are 64-bit (__u64) regardless of architecture. However, bcmgenet_get_ethtool_stats() retained a legacy check: if (sizeof(unsigned long) != sizeof(u32) && s->stat_sizeof == sizeof(unsigned long)) On 32-bit systems, sizeof(unsigned long) == sizeof(u32), causing this condition to evaluate to false. As a result, 64-bit RTNL stats fields were read via *(u32 *)p. On 32-bit Big-Endian systems (such as MIPS BE), this reads the high 32 bits and returns 0 until the counter exceeds 4GB; on 32-bit Little-Endian systems (such as 32-bit ARM), the value is truncated to 32 bits. Fix this by checking if s->stat_sizeof == sizeof(u64) so 64-bit fields are always read as 64-bit values. Fixes: 59aa6e3072aa ("net: bcmgenet: switch to use 64bit statistics") Reviewed-by: Nicolai Buchwitz Signed-off-by: Florian Fainelli Link: https://patch.msgid.link/20260921220021.281418-2-florian.fainelli@broadcom.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/broadcom/genet/bcmgenet.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/broadcom/genet/bcmgenet.c b/drivers/net/ethernet/broadcom/genet/bcmgenet.c index ca62041efecd..47a6c073c8d9 100644 --- a/drivers/net/ethernet/broadcom/genet/bcmgenet.c +++ b/drivers/net/ethernet/broadcom/genet/bcmgenet.c @@ -1346,9 +1346,8 @@ static void bcmgenet_get_ethtool_stats(struct net_device *dev, p = (char *)&stats64; p += s->stat_offset; - if (sizeof(unsigned long) != sizeof(u32) && - s->stat_sizeof == sizeof(unsigned long)) - data[i] = *(unsigned long *)p; + if (s->stat_sizeof == sizeof(u64)) + data[i] = *(u64 *)p; else data[i] = *(u32 *)p; }