diff options
| author | Kirill Tkhai <ktkhai@parallels.com> | 2014-09-22 22:36:24 +0400 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2014-11-17 14:11:38 +0000 |
| commit | 49bef5ac78f9fcebbe87942e867cef864c1147cd (patch) | |
| tree | f8cdb62e1b2531f09a1c95915988fe8261d8f2cf /kernel | |
| parent | 427ee2fadbd2d6da087c6a03bd5c45e89ae76035 (diff) | |
sched: Use dl_bw_of() under RCU read lock
commit 66339c31bc3978d5fff9c4b4cb590a861def4db2 upstream.
dl_bw_of() dereferences rq->rd which has to have RCU read lock held.
Probability of use-after-free isn't zero here.
Also add lockdep assert into dl_bw_cpus().
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20140922183624.11015.71558.stgit@localhost
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 0acf96b790c5..169720f46c30 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1969,6 +1969,8 @@ unsigned long to_ratio(u64 period, u64 runtime) #ifdef CONFIG_SMP inline struct dl_bw *dl_bw_of(int i) { + rcu_lockdep_assert(rcu_read_lock_sched_held(), + "sched RCU must be held"); return &cpu_rq(i)->rd->dl_bw; } @@ -1977,6 +1979,8 @@ static inline int dl_bw_cpus(int i) struct root_domain *rd = cpu_rq(i)->rd; int cpus = 0; + rcu_lockdep_assert(rcu_read_lock_sched_held(), + "sched RCU must be held"); for_each_cpu_and(i, rd->span, cpu_active_mask) cpus++; @@ -7541,6 +7545,8 @@ static int sched_dl_global_constraints(void) int cpu, ret = 0; unsigned long flags; + rcu_read_lock(); + /* * Here we want to check the bandwidth not being set to some * value smaller than the currently allocated bandwidth in @@ -7562,6 +7568,8 @@ static int sched_dl_global_constraints(void) break; } + rcu_read_unlock(); + return ret; } @@ -7577,6 +7585,7 @@ static void sched_dl_do_global(void) if (global_rt_runtime() != RUNTIME_INF) new_bw = to_ratio(global_rt_period(), global_rt_runtime()); + rcu_read_lock(); /* * FIXME: As above... */ @@ -7587,6 +7596,7 @@ static void sched_dl_do_global(void) dl_b->bw = new_bw; raw_spin_unlock_irqrestore(&dl_b->lock, flags); } + rcu_read_unlock(); } static int sched_rt_global_validate(void) |