hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

net: mdiobus: Disable preemption upon u64_stats update 

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>
This commit is contained in:
Ahmed S. Darwish 2020-06-03 16:49:47 +02:00 committed by David S. Miller
parent 6501bf8760
commit c7e261d817
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/net/phy/mdio_bus.c
View File

@ -764,6 +764,7 @@ 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);
@ -778,6 +779,7 @@ 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();
}
/**