From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: linux-kernel@vger.kernel.org
Cc: mingo@kernel.org, jiangshanlai@gmail.com, dipankar@in.ibm.com,
akpm@linux-foundation.org, mathieu.desnoyers@efficios.com,
josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org,
rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com,
dvhart@linux.intel.com, fweisbec@gmail.com, oleg@redhat.com,
bobby.prani@gmail.com,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Subject: [PATCH tip/core/rcu 09/16] rcu: Force boolean subscript for expedited stall warnings
Date: Tue, 12 Apr 2016 08:29:28 -0700 [thread overview]
Message-ID: <1460474975-24560-9-git-send-email-paulmck@linux.vnet.ibm.com> (raw)
In-Reply-To: <20160412152906.GA23395@linux.vnet.ibm.com>
The cpu_online() function can return values other than 0 and 1, which
can result in subscript overflow when applied to a two-element array.
This commit allows for this behavior by using "!!" on the return value
from cpu_online() when used as a subscript.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/rcu/tree.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 62e73e0a929f..64c2e3288551 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3808,7 +3808,7 @@ static void synchronize_sched_expedited_wait(struct rcu_state *rsp)
ndetected++;
rdp = per_cpu_ptr(rsp->rda, cpu);
pr_cont(" %d-%c%c%c", cpu,
- "O."[cpu_online(cpu)],
+ "O."[!!cpu_online(cpu)],
"o."[!!(rdp->grpmask & rnp->expmaskinit)],
"N."[!!(rdp->grpmask & rnp->expmaskinitnext)]);
}
--
2.5.2
next prev parent reply other threads:[~2016-04-12 15:29 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-12 15:29 [PATCH tip/core/rcu 0/16] Expedited grace-period changes for 4.7 Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 01/16] rcu: Make expedited RCU-sched grace period immediately detect idle Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 02/16] rcu: Make expedited RCU-preempt stall warnings count accurately Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 03/16] rcu: Make cond_resched_rcu_qs() supply RCU-sched expedited QS Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 04/16] rcu: Fix synchronize_rcu_expedited() header comment Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 05/16] rcu: Add event tracing definitions for expedited grace periods Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 06/16] rcu: Add funnel-locking tracing " Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 07/16] rcu: Add expedited-grace-period event tracing Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 08/16] rcu: Remove expedited GP funnel-lock bypass Paul E. McKenney
2016-04-12 15:29 ` Paul E. McKenney [this message]
2016-04-12 15:29 ` [PATCH tip/core/rcu 10/16] rcu: Shorten expedited_workdone* to exp_workdone* Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 11/16] rcu: Enforce expedited-GP fairness via funnel wait queue Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 12/16] rcu: Add exp_funnel_lock() fastpath Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 13/16] rcu: Consolidate expedited GP code into rcu_exp_wait_wake() Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 14/16] rcu: Consolidate expedited GP tracing into rcu_exp_gp_seq_snap() Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 15/16] rcu: Consolidate expedited GP code into exp_funnel_lock() Paul E. McKenney
2016-04-12 15:29 ` [PATCH tip/core/rcu 16/16] rcu: Overlap wakeups with next expedited grace period Paul E. McKenney
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