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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2011-05-03 08:40:04 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2011-05-06 08:16:59 +0200 |
| commit | bad6e1393cb505fe17747344a23666464daa3fa7 (patch) | |
| tree | 521dcada78d0f19400d14547381f0f3b2e38fea2 | |
| parent | rcu: optimize rcutiny (diff) | |
| download | linux-bad6e1393cb505fe17747344a23666464daa3fa7.tar.xz linux-bad6e1393cb505fe17747344a23666464daa3fa7.zip | |
rcu: get rid of signed overflow in check_cpu_stall()
Signed integer overflow is undefined by the C standard, so move
calculations to unsigned.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| -rw-r--r-- | kernel/rcutree.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/kernel/rcutree.c b/kernel/rcutree.c index 78923a50cdb2..b2fe2a273df2 100644 --- a/kernel/rcutree.c +++ b/kernel/rcutree.c @@ -581,21 +581,24 @@ static void print_cpu_stall(struct rcu_state *rsp) static void check_cpu_stall(struct rcu_state *rsp, struct rcu_data *rdp) { - long delta; + unsigned long j; + unsigned long js; struct rcu_node *rnp; if (rcu_cpu_stall_suppress) return; - delta = jiffies - ACCESS_ONCE(rsp->jiffies_stall); + j = ACCESS_ONCE(jiffies); + js = ACCESS_ONCE(rsp->jiffies_stall); rnp = rdp->mynode; - if ((ACCESS_ONCE(rnp->qsmask) & rdp->grpmask) && delta >= 0) { + if ((ACCESS_ONCE(rnp->qsmask) & rdp->grpmask) && ULONG_CMP_GE(j, js)) { /* We haven't checked in, so go dump stack. */ print_cpu_stall(rsp); - } else if (rcu_gp_in_progress(rsp) && delta >= RCU_STALL_RAT_DELAY) { + } else if (rcu_gp_in_progress(rsp) && + ULONG_CMP_GE(j, js + RCU_STALL_RAT_DELAY)) { - /* They had two time units to dump stack, so complain. */ + /* They had a few time units to dump stack, so complain. */ print_other_cpu_stall(rsp); } } |