diff options
| -rw-r--r-- | include/linux/bpf.h | 6 | ||||
| -rw-r--r-- | kernel/bpf/arraymap.c | 4 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 19 |
3 files changed, 25 insertions, 4 deletions
diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 8821b9a..5f520f5 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -123,7 +123,10 @@ struct bpf_prog_aux { const struct bpf_verifier_ops *ops; struct bpf_map **used_maps; struct bpf_prog *prog; - struct work_struct work; + union { + struct work_struct work; + struct rcu_head rcu; + }; }; struct bpf_array { @@ -153,6 +156,7 @@ void bpf_register_map_type(struct bpf_map_type_list *tl); struct bpf_prog *bpf_prog_get(u32 ufd); void bpf_prog_put(struct bpf_prog *prog); +void bpf_prog_put_rcu(struct bpf_prog *prog); struct bpf_map *bpf_map_get(struct fd f); void bpf_map_put(struct bpf_map *map); diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 614bcd4..cb31229 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -202,7 +202,7 @@ static int prog_array_map_update_elem(struct bpf_map *map, void *key, old_prog = xchg(array->prog + index, prog); if (old_prog) - bpf_prog_put(old_prog); + bpf_prog_put_rcu(old_prog); return 0; } @@ -218,7 +218,7 @@ static int prog_array_map_delete_elem(struct bpf_map *map, void *key) old_prog = xchg(array->prog + index, NULL); if (old_prog) { - bpf_prog_put(old_prog); + bpf_prog_put_rcu(old_prog); return 0; } else { return -ENOENT; diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 98a69bd..a1b14d1 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -432,6 +432,23 @@ static void free_used_maps(struct bpf_prog_aux *aux) kfree(aux->used_maps); } +static void __prog_put_rcu(struct rcu_head *rcu) +{ + struct bpf_prog_aux *aux = container_of(rcu, struct bpf_prog_aux, rcu); + + free_used_maps(aux); + bpf_prog_free(aux->prog); +} + +/* version of bpf_prog_put() that is called after a grace period */ +void bpf_prog_put_rcu(struct bpf_prog *prog) +{ + if (atomic_dec_and_test(&prog->aux->refcnt)) { + prog->aux->prog = prog; + call_rcu(&prog->aux->rcu, __prog_put_rcu); + } +} + void bpf_prog_put(struct bpf_prog *prog) { if (atomic_dec_and_test(&prog->aux->refcnt)) { @@ -445,7 +462,7 @@ static int bpf_prog_release(struct inode *inode, struct file *filp) { struct bpf_prog *prog = filp->private_data; - bpf_prog_put(prog); + bpf_prog_put_rcu(prog); return 0; } |