diff options
| author | Hou Tao <houtao1@huawei.com> | 2022-10-14 19:39:46 +0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-10-18 10:27:02 -0700 |
| commit | 4835f9ee980c1867584018e69cbf1f62d7844cb3 (patch) | |
| tree | e2b8022025e270d1f39a04f592dbdd468be80f94 /kernel/bpf/core.c | |
| parent | d39d1445d37747032e2b26732fed6fe25161cd36 (diff) | |
| download | lwn-4835f9ee980c1867584018e69cbf1f62d7844cb3.tar.gz lwn-4835f9ee980c1867584018e69cbf1f62d7844cb3.zip | |
bpf: Use rcu_trace_implies_rcu_gp() for program array freeing
To support both sleepable and normal uprobe bpf program, the freeing of
trace program array chains a RCU-tasks-trace grace period and a normal
RCU grace period one after the other.
With the introduction of rcu_trace_implies_rcu_gp(),
__bpf_prog_array_free_sleepable_cb() can check whether or not a normal
RCU grace period has also passed after a RCU-tasks-trace grace period
has passed. If it is true, it is safe to invoke kfree() directly.
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20221014113946.965131-5-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf/core.c')
| -rw-r--r-- | kernel/bpf/core.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 711fd293b6de..4bc5f46d7030 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2251,8 +2251,14 @@ static void __bpf_prog_array_free_sleepable_cb(struct rcu_head *rcu) { struct bpf_prog_array *progs; + /* If RCU Tasks Trace grace period implies RCU grace period, there is + * no need to call kfree_rcu(), just call kfree() directly. + */ progs = container_of(rcu, struct bpf_prog_array, rcu); - kfree_rcu(progs, rcu); + if (rcu_trace_implies_rcu_gp()) + kfree(progs); + else + kfree_rcu(progs, rcu); } void bpf_prog_array_free_sleepable(struct bpf_prog_array *progs) |