On 8/26/25 11:38 AM, Kuniyuki Iwashima wrote:
We will store a flag in sk->sk_memcg by bpf_setsockopt() during
socket() or before sk->sk_memcg is set in accept().
BPF_CGROUP_INET_SOCK_CREATE is invoked by __cgroup_bpf_run_filter_sk()
that passes a pointer to struct sock to the bpf prog as void *ctx.
But there are no bpf_func_proto for bpf_setsockopt() that receives
the ctx as a pointer to struct sock.
Let's add a new bpf_setsockopt() variant for BPF_CGROUP_INET_SOCK_CREATE.
Note that inet_create() is not under lock_sock().
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
---
v3: Remove bpf_func_proto for accept()
v2: Make 2 new bpf_func_proto static
---
net/core/filter.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/net/core/filter.c b/net/core/filter.c
index 63f3baee2daf..443d12b7d3b2 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5743,6 +5743,23 @@ static const struct bpf_func_proto bpf_sock_ops_setsockopt_proto = {
.arg5_type = ARG_CONST_SIZE,
};
+BPF_CALL_5(bpf_unlocked_sock_setsockopt, struct sock *, sk, int, level,
+ int, optname, char *, optval, int, optlen)
+{
+ return _bpf_setsockopt(sk, level, optname, optval, optlen);
The sock_owned_by_me() will warn.
From CI:
WARNING: CPU: 0 PID: 102 at include/net/sock.h:1756 bpf_unlocked_sock_setsockopt+0xc7/0x110
+}
+
+static const struct bpf_func_proto bpf_unlocked_sock_setsockopt_proto = {
+ .func = bpf_unlocked_sock_setsockopt,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+ .arg2_type = ARG_ANYTHING,
+ .arg3_type = ARG_ANYTHING,
+ .arg4_type = ARG_PTR_TO_MEM | MEM_RDONLY,
+ .arg5_type = ARG_CONST_SIZE,
+};
+
static int bpf_sock_ops_get_syn(struct bpf_sock_ops_kern *bpf_sock,
int optname, const u8 **start)
{
@@ -8051,6 +8068,13 @@ sock_filter_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sk_storage_get_cg_sock_proto;
case BPF_FUNC_ktime_get_coarse_ns:
return &bpf_ktime_get_coarse_ns_proto;
+ case BPF_FUNC_setsockopt:
+ switch (prog->expected_attach_type) {
+ case BPF_CGROUP_INET_SOCK_CREATE:
+ return &bpf_unlocked_sock_setsockopt_proto;
+ default:
+ return NULL;
+ }
default:
return bpf_base_func_proto(func_id, prog);
}
