bpf: hash map, avoid deadlock with suitable hash mask

[linux-2.6-microblaze.git] / kernel / bpf / hashtab.c

diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 5aa2b55..66bded1 100644 (file)
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -152,7 +152,7 @@ static inline int htab_lock_bucket(const struct bpf_htab *htab,
 {
        unsigned long flags;
 
-       hash = hash & HASHTAB_MAP_LOCK_MASK;
+       hash = hash & min_t(u32, HASHTAB_MAP_LOCK_MASK, htab->n_buckets - 1);
 
        preempt_disable();
        if (unlikely(__this_cpu_inc_return(*(htab->map_locked[hash])) != 1)) {
@@ -171,7 +171,7 @@ static inline void htab_unlock_bucket(const struct bpf_htab *htab,
                                      struct bucket *b, u32 hash,
                                      unsigned long flags)
 {
-       hash = hash & HASHTAB_MAP_LOCK_MASK;
+       hash = hash & min_t(u32, HASHTAB_MAP_LOCK_MASK, htab->n_buckets - 1);
        raw_spin_unlock_irqrestore(&b->raw_lock, flags);
        __this_cpu_dec(*(htab->map_locked[hash]));
        preempt_enable();