diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/cpumap.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index 04171fbc39cb..32b43cb9061b 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -29,6 +29,7 @@ #include <linux/sched.h> #include <linux/workqueue.h> #include <linux/kthread.h> +#include <linux/local_lock.h> #include <linux/completion.h> #include <trace/events/xdp.h> #include <linux/btf_ids.h> @@ -52,6 +53,7 @@ struct xdp_bulk_queue { struct list_head flush_node; struct bpf_cpu_map_entry *obj; unsigned int count; + local_lock_t bq_lock; }; /* Struct for every remote "destination" CPU in map */ @@ -451,6 +453,7 @@ __cpu_map_entry_alloc(struct bpf_map *map, struct bpf_cpumap_val *value, for_each_possible_cpu(i) { bq = per_cpu_ptr(rcpu->bulkq, i); bq->obj = rcpu; + local_lock_init(&bq->bq_lock); } /* Alloc queue */ @@ -722,6 +725,8 @@ static void bq_flush_to_queue(struct xdp_bulk_queue *bq) struct ptr_ring *q; int i; + lockdep_assert_held(&bq->bq_lock); + if (unlikely(!bq->count)) return; @@ -749,11 +754,15 @@ static void bq_flush_to_queue(struct xdp_bulk_queue *bq) } /* Runs under RCU-read-side, plus in softirq under NAPI protection. - * Thus, safe percpu variable access. + * Thus, safe percpu variable access. PREEMPT_RT relies on + * local_lock_nested_bh() to serialise access to the per-CPU bq. */ static void bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf) { - struct xdp_bulk_queue *bq = this_cpu_ptr(rcpu->bulkq); + struct xdp_bulk_queue *bq; + + local_lock_nested_bh(&rcpu->bulkq->bq_lock); + bq = this_cpu_ptr(rcpu->bulkq); if (unlikely(bq->count == CPU_MAP_BULK_SIZE)) bq_flush_to_queue(bq); @@ -774,6 +783,8 @@ static void bq_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf) list_add(&bq->flush_node, flush_list); } + + local_unlock_nested_bh(&rcpu->bulkq->bq_lock); } int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_frame *xdpf, @@ -810,7 +821,9 @@ void __cpu_map_flush(struct list_head *flush_list) struct xdp_bulk_queue *bq, *tmp; list_for_each_entry_safe(bq, tmp, flush_list, flush_node) { + local_lock_nested_bh(&bq->obj->bulkq->bq_lock); bq_flush_to_queue(bq); + local_unlock_nested_bh(&bq->obj->bulkq->bq_lock); /* If already running, costs spin_lock_irqsave + smb_mb */ wake_up_process(bq->obj->kthread); |