From: "Ahmed S. Darwish" a.darwish@linutronix.de
[ Upstream commit c7e261d81783387a0502878cd229327e7c54322e ]
The u64_stats mechanism uses sequence counters to protect against 64-bit values tearing on 32-bit architectures. Updating u64_stats is thus a sequence counter write side critical section where preemption must be disabled.
For mdiobus_stats_acct(), disable preemption upon the u64_stats update. It is called from process context through mdiobus_read() and mdiobus_write().
Reported-by: kernel test robot lkp@intel.com Signed-off-by: Ahmed S. Darwish a.darwish@linutronix.de Reviewed-by: Sebastian Andrzej Siewior bigeasy@linutronix.de Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/phy/mdio_bus.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c index 7a4eb3f2cb74..a1a4dee2a033 100644 --- a/drivers/net/phy/mdio_bus.c +++ b/drivers/net/phy/mdio_bus.c @@ -757,6 +757,7 @@ EXPORT_SYMBOL(mdiobus_scan);
static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret) { + preempt_disable(); u64_stats_update_begin(&stats->syncp);
u64_stats_inc(&stats->transfers); @@ -771,6 +772,7 @@ static void mdiobus_stats_acct(struct mdio_bus_stats *stats, bool op, int ret) u64_stats_inc(&stats->writes); out: u64_stats_update_end(&stats->syncp); + preempt_enable(); }
/**