bonding: Fix jiffies overflow problems (again)
The time_before_eq()/time_after_eq() functions operate on unsigned
long and only work if the difference between the two compared values
is smaller than half the range of unsigned long (31 bits on i386).
Some of the variables (slave->jiffies, dev->trans_start, dev->last_rx)
used by bonding store a copy of jiffies and may not be updated for a
long time. With HZ=1000, time_before_eq()/time_after_eq() will start
giving bad results after ~25 days.
jiffies will never be before slave->jiffies, dev->trans_start,
dev->last_rx by more than possibly a couple ticks caused by preemption
of this code. This allows us to detect/prevent these overflows by
replacing time_before_eq()/time_after_eq() with time_in_range().
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed