diff options
| author |   Alexis Lothoré <alexis.lothore@bootlin.com> | 2025-05-29 11:07:23 +0200 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2025-05-30 19:33:28 -0700 |
| commit | 030ce919e114a111e83b7976ecb3597cefd33f26 (patch) | |
| tree | 8e9589d7956adc27a3dcd569172e702421636a4c /drivers | |
| parent | hv_netvsc: fix potential deadlock in netvsc_vf_setxdp() (diff) | |
| download | wireguard-linux-030ce919e114a111e83b7976ecb3597cefd33f26.tar.xz wireguard-linux-030ce919e114a111e83b7976ecb3597cefd33f26.zip | |
net: stmmac: make sure that ptp_rate is not 0 before configuring timestamping
The stmmac platform drivers that do not open-code the clk_ptp_rate value
after having retrieved the default one from the device-tree can end up
with 0 in clk_ptp_rate (as clk_get_rate can return 0). It will
eventually propagate up to PTP initialization when bringing up the
interface, leading to a divide by 0:
Division by zero in kernel.
CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.30-00001-g48313bd5768a #22
Hardware name: STM32 (Device Tree Support)
Call trace:
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x6c/0x8c
dump_stack_lvl from Ldiv0_64+0x8/0x18
Ldiv0_64 from stmmac_init_tstamp_counter+0x190/0x1a4
stmmac_init_tstamp_counter from stmmac_hw_setup+0xc1c/0x111c
stmmac_hw_setup from __stmmac_open+0x18c/0x434
__stmmac_open from stmmac_open+0x3c/0xbc
stmmac_open from __dev_open+0xf4/0x1ac
__dev_open from __dev_change_flags+0x1cc/0x224
__dev_change_flags from dev_change_flags+0x24/0x60
dev_change_flags from ip_auto_config+0x2e8/0x11a0
ip_auto_config from do_one_initcall+0x84/0x33c
do_one_initcall from kernel_init_freeable+0x1b8/0x214
kernel_init_freeable from kernel_init+0x24/0x140
kernel_init from ret_from_fork+0x14/0x28
Exception stack(0xe0815fb0 to 0xe0815ff8)
Prevent this division by 0 by adding an explicit check and error log
about the actual issue. While at it, remove the same check from
stmmac_ptp_register, which then becomes duplicate
Fixes: 19d857c9038e ("stmmac: Fix calculations for ptp counters when clock input = 50Mhz.")
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Reviewed-by: Yanteng Si <si.yanteng@linux.dev>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20250529-stmmac_tstamp_div-v4-1-d73340a794d5@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 5 | ||||
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c | 2 |
2 files changed, 6 insertions, 1 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 085c09039af4..1369fa70bc58 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -805,6 +805,11 @@ int stmmac_init_tstamp_counter(struct stmmac_priv *priv, u32 systime_flags) if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp)) return -EOPNOTSUPP; + if (!priv->plat->clk_ptp_rate) { + netdev_err(priv->dev, "Invalid PTP clock rate"); + return -EINVAL; + } + stmmac_config_hw_tstamping(priv, priv->ptpaddr, systime_flags); priv->systime_flags = systime_flags; diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c index 429b2d357813..3767ba495e78 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c @@ -317,7 +317,7 @@ void stmmac_ptp_register(struct stmmac_priv *priv) /* Calculate the clock domain crossing (CDC) error if necessary */ priv->plat->cdc_error_adj = 0; - if (priv->plat->has_gmac4 && priv->plat->clk_ptp_rate) + if (priv->plat->has_gmac4) priv->plat->cdc_error_adj = (2 * NSEC_PER_SEC) / priv->plat->clk_ptp_rate; /* Update the ptp clock parameters based on feature discovery, when |