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| author | Iulia Manda <iulia.manda21@gmail.com> | 2014-03-11 15:22:28 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-04-29 08:43:45 -0700 |
| commit | 4fc5b75537d4f56577ad00355b4cd09627deb3c3 (patch) | |
| tree | 08b95f7d425cd0f610dd545fbe8fbea282a7f87f /kernel/rcu | |
| parent | 9b67122ae3da3018c966148233739116ed89502a (diff) | |
| download | blackbird-op-linux-4fc5b75537d4f56577ad00355b4cd09627deb3c3.tar.gz blackbird-op-linux-4fc5b75537d4f56577ad00355b4cd09627deb3c3.zip | |
rcu: Protect uses of jiffies_stall field with ACCESS_ONCE()
Some of the uses of the rcu_state structure's ->jiffies_stall field
do not use ACCESS_ONCE(), despite there being unprotected accesses.
This commit therefore uses the ACCESS_ONCE() macro to protect this field.
Signed-off-by: Iulia Manda <iulia.manda21@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 2cc39c781085..c624415f8386 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -865,7 +865,7 @@ static void record_gp_stall_check_time(struct rcu_state *rsp) rsp->gp_start = j; smp_wmb(); /* Record start time before stall time. */ j1 = rcu_jiffies_till_stall_check(); - rsp->jiffies_stall = j + j1; + ACCESS_ONCE(rsp->jiffies_stall) = j + j1; rsp->jiffies_resched = j + j1 / 2; } @@ -904,12 +904,12 @@ static void print_other_cpu_stall(struct rcu_state *rsp) /* Only let one CPU complain about others per time interval. */ raw_spin_lock_irqsave(&rnp->lock, flags); - delta = jiffies - rsp->jiffies_stall; + delta = jiffies - ACCESS_ONCE(rsp->jiffies_stall); if (delta < RCU_STALL_RAT_DELAY || !rcu_gp_in_progress(rsp)) { raw_spin_unlock_irqrestore(&rnp->lock, flags); return; } - rsp->jiffies_stall = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; + ACCESS_ONCE(rsp->jiffies_stall) = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; raw_spin_unlock_irqrestore(&rnp->lock, flags); /* @@ -992,8 +992,8 @@ static void print_cpu_stall(struct rcu_state *rsp) dump_stack(); raw_spin_lock_irqsave(&rnp->lock, flags); - if (ULONG_CMP_GE(jiffies, rsp->jiffies_stall)) - rsp->jiffies_stall = jiffies + + if (ULONG_CMP_GE(jiffies, ACCESS_ONCE(rsp->jiffies_stall))) + ACCESS_ONCE(rsp->jiffies_stall) = jiffies + 3 * rcu_jiffies_till_stall_check() + 3; raw_spin_unlock_irqrestore(&rnp->lock, flags); @@ -1077,7 +1077,7 @@ void rcu_cpu_stall_reset(void) struct rcu_state *rsp; for_each_rcu_flavor(rsp) - rsp->jiffies_stall = jiffies + ULONG_MAX / 2; + ACCESS_ONCE(rsp->jiffies_stall) = jiffies + ULONG_MAX / 2; } /* |
