diff options
| author | Wei Fang <wei.fang@nxp.com> | 2026-06-24 15:27:26 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-06-25 08:40:08 -0700 |
| commit | 5da65537792b68b6052ffcab65e04c27aea6dfe4 (patch) | |
| tree | 2dcef3e28d40d1442314ccf5edf84807d3ee4e9d | |
| parent | 14eb1d2c03b38ce3427f299967f7a4d97ebff4c2 (diff) | |
| download | ath-5da65537792b68b6052ffcab65e04c27aea6dfe4.tar.gz | |
net: enetc: fix potential divide-by-zero when num_vsi is zero
For i.MX94 series, all the standalone ENETCs do not support SR-IOV, so
pf->caps.num_vsi is zero. This leads to a divide-by-zero in
enetc4_default_rings_allocation() when distributing rings among PF and
VFs.
Division by zero is undefined behavior in C. On ARM64, the UDIV/SDIV
instructions silently return zero rather than raising an exception, so
the issue does not cause a visible crash. However, relying on this
behavior is incorrect and poses a cross-platform compatibility risk.
Add an explicit check for num_vsi == 0 and return early after the PF's
rings have been configured.
Fixes: 2d673b0e2f8d ("net: enetc: add standalone ENETC support for i.MX94")
Signed-off-by: Wei Fang <wei.fang@nxp.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260624072726.1238903-1-wei.fang@oss.nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/freescale/enetc/enetc4_pf.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/net/ethernet/freescale/enetc/enetc4_pf.c b/drivers/net/ethernet/freescale/enetc/enetc4_pf.c index 4e771f8523580..437a15bbb47ba 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc4_pf.c +++ b/drivers/net/ethernet/freescale/enetc/enetc4_pf.c @@ -322,6 +322,9 @@ static void enetc4_default_rings_allocation(struct enetc_pf *pf) val = enetc4_psicfgr0_val_construct(false, num_tx_bdr, num_rx_bdr); enetc_port_wr(hw, ENETC4_PSICFGR0(0), val); + if (!pf->caps.num_vsi) + return; + num_rx_bdr = pf->caps.num_rx_bdr - num_rx_bdr; rx_rem = num_rx_bdr % pf->caps.num_vsi; num_rx_bdr = num_rx_bdr / pf->caps.num_vsi; |