diff options
| author | Chris Redpath <chris.redpath@arm.com> | 2015-02-03 21:19:41 +0900 |
|---|---|---|
| committer | Seung-Woo Kim <sw0312.kim@samsung.com> | 2016-12-14 13:41:49 +0900 |
| commit | 8209016c92325719af3aab2b8e7de3c568ecdfb9 (patch) | |
| tree | ce8d901136f23d920df48af7760b732a29a03fa6 /kernel | |
| parent | 9b05ce6bf65f21ba34854b77833d9b9208b925f9 (diff) | |
hmp: Remove potential for task_struct access race
Accessing the task_struct can be racy in certain conditions, so
we need to only acquire the data when needed.
Signed-off-by: Chris Redpath <chris.redpath@arm.com>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Signed-off-by: Jon Medhurst <tixy@linaro.org>
[k.kozlowski: rebased on 4.1, no signed-off-by of previous committer]
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/fair.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index f4c732ae143f..10280438fcb1 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8784,6 +8784,7 @@ static int hmp_active_task_migration_cpu_stop(void *data) rcu_read_unlock(); double_unlock_balance(busiest_rq, target_rq); out_unlock: + put_task_struct(p); busiest_rq->active_balance = 0; raw_spin_unlock_irq(&busiest_rq->lock); return 0; @@ -8857,6 +8858,7 @@ static int hmp_idle_pull_cpu_stop(void *data) rcu_read_unlock(); double_unlock_balance(busiest_rq, target_rq); out_unlock: + put_task_struct(p); busiest_rq->active_balance = 0; raw_spin_unlock_irq(&busiest_rq->lock); return 0; @@ -8902,6 +8904,7 @@ static void hmp_force_up_migration(int this_cpu) p = task_of(curr); if (hmp_up_migration(cpu, &target_cpu, curr)) { if (!target->active_balance) { + get_task_struct(p); target->active_balance = 1; target->push_cpu = target_cpu; target->migrate_task = p; @@ -8917,8 +8920,10 @@ static void hmp_force_up_migration(int this_cpu) * require extensive book keeping. */ curr = hmp_get_lightest_task(orig, 1); + p = task_of(curr); target->push_cpu = hmp_offload_down(cpu, curr); if (target->push_cpu < NR_CPUS) { + get_task_struct(p); target->active_balance = 1; target->migrate_task = p; force = 1; @@ -8997,6 +9002,7 @@ static unsigned int hmp_idle_pull(int this_cpu) /* now we have a candidate */ raw_spin_lock_irqsave(&target->lock, flags); if (!target->active_balance && task_rq(p) == target) { + get_task_struct(p); target->active_balance = 1; target->push_cpu = this_cpu; target->migrate_task = p; |