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>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 2cc4cfc..3b16f62 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2797,9 +2797,15 @@
* so it can wait
*/
bond_for_each_slave(bond, slave, i) {
+ unsigned long trans_start = dev_trans_start(slave->dev);
+
if (slave->link != BOND_LINK_UP) {
- if (time_before_eq(jiffies, dev_trans_start(slave->dev) + delta_in_ticks) &&
- time_before_eq(jiffies, slave->dev->last_rx + delta_in_ticks)) {
+ if (time_in_range(jiffies,
+ trans_start - delta_in_ticks,
+ trans_start + delta_in_ticks) &&
+ time_in_range(jiffies,
+ slave->dev->last_rx - delta_in_ticks,
+ slave->dev->last_rx + delta_in_ticks)) {
slave->link = BOND_LINK_UP;
slave->state = BOND_STATE_ACTIVE;
@@ -2827,8 +2833,12 @@
* when the source ip is 0, so don't take the link down
* if we don't know our ip yet
*/
- if (time_after_eq(jiffies, dev_trans_start(slave->dev) + 2*delta_in_ticks) ||
- (time_after_eq(jiffies, slave->dev->last_rx + 2*delta_in_ticks))) {
+ if (!time_in_range(jiffies,
+ trans_start - delta_in_ticks,
+ trans_start + 2 * delta_in_ticks) ||
+ !time_in_range(jiffies,
+ slave->dev->last_rx - delta_in_ticks,
+ slave->dev->last_rx + 2 * delta_in_ticks)) {
slave->link = BOND_LINK_DOWN;
slave->state = BOND_STATE_BACKUP;
@@ -2883,13 +2893,16 @@
{
struct slave *slave;
int i, commit = 0;
+ unsigned long trans_start;
bond_for_each_slave(bond, slave, i) {
slave->new_link = BOND_LINK_NOCHANGE;
if (slave->link != BOND_LINK_UP) {
- if (time_before_eq(jiffies, slave_last_rx(bond, slave) +
- delta_in_ticks)) {
+ if (time_in_range(jiffies,
+ slave_last_rx(bond, slave) - delta_in_ticks,
+ slave_last_rx(bond, slave) + delta_in_ticks)) {
+
slave->new_link = BOND_LINK_UP;
commit++;
}
@@ -2902,8 +2915,9 @@
* active. This avoids bouncing, as the last receive
* times need a full ARP monitor cycle to be updated.
*/
- if (!time_after_eq(jiffies, slave->jiffies +
- 2 * delta_in_ticks))
+ if (time_in_range(jiffies,
+ slave->jiffies - delta_in_ticks,
+ slave->jiffies + 2 * delta_in_ticks))
continue;
/*
@@ -2921,8 +2935,10 @@
*/
if (slave->state == BOND_STATE_BACKUP &&
!bond->current_arp_slave &&
- time_after(jiffies, slave_last_rx(bond, slave) +
- 3 * delta_in_ticks)) {
+ !time_in_range(jiffies,
+ slave_last_rx(bond, slave) - delta_in_ticks,
+ slave_last_rx(bond, slave) + 3 * delta_in_ticks)) {
+
slave->new_link = BOND_LINK_DOWN;
commit++;
}
@@ -2933,11 +2949,15 @@
* - (more than 2*delta since receive AND
* the bond has an IP address)
*/
+ trans_start = dev_trans_start(slave->dev);
if ((slave->state == BOND_STATE_ACTIVE) &&
- (time_after_eq(jiffies, dev_trans_start(slave->dev) +
- 2 * delta_in_ticks) ||
- (time_after_eq(jiffies, slave_last_rx(bond, slave)
- + 2 * delta_in_ticks)))) {
+ (!time_in_range(jiffies,
+ trans_start - delta_in_ticks,
+ trans_start + 2 * delta_in_ticks) ||
+ !time_in_range(jiffies,
+ slave_last_rx(bond, slave) - delta_in_ticks,
+ slave_last_rx(bond, slave) + 2 * delta_in_ticks))) {
+
slave->new_link = BOND_LINK_DOWN;
commit++;
}
@@ -2956,6 +2976,7 @@
{
struct slave *slave;
int i;
+ unsigned long trans_start;
bond_for_each_slave(bond, slave, i) {
switch (slave->new_link) {
@@ -2963,10 +2984,11 @@
continue;
case BOND_LINK_UP:
+ trans_start = dev_trans_start(slave->dev);
if ((!bond->curr_active_slave &&
- time_before_eq(jiffies,
- dev_trans_start(slave->dev) +
- delta_in_ticks)) ||
+ time_in_range(jiffies,
+ trans_start - delta_in_ticks,
+ trans_start + delta_in_ticks)) ||
bond->curr_active_slave != slave) {
slave->link = BOND_LINK_UP;
bond->current_arp_slave = NULL;