Commit 2c5b6bf5 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: net: Avoid sk_getsockopt() taking sk lock when called from bpf 



Similar to the earlier commit that changed sk_setsockopt() to
use sockopt_{lock,release}_sock() such that it can avoid taking
lock when called from bpf.  This patch also changes sk_getsockopt()
to use sockopt_{lock,release}_sock() such that a latter patch can
make bpf_getsockopt(SOL_SOCKET) to reuse sk_getsockopt().

Only sk_get_filter() requires this change and it is used by
the optname SO_GET_FILTER.

The '.getname' implementations in sock->ops->getname() is not
changed also since bpf does not always have the sk->sk_socket
pointer and cannot support SO_PEERNAME.

Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002809.2888981-1-kafai@fb.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 4ff09db1

net/core/filter.c

+2 −2
Original line number Diff line number Diff line
@@ -10722,7 +10722,7 @@ int sk_get_filter(struct sock *sk, sockptr_t optval, unsigned int len) 
	struct sk_filter *filter;

	int ret = 0;



	lock_sock(sk);

	sockopt_lock_sock(sk);

	filter = rcu_dereference_protected(sk->sk_filter,

					   lockdep_sock_is_held(sk));

	if (!filter)
@@ -10755,7 +10755,7 @@ int sk_get_filter(struct sock *sk, sockptr_t optval, unsigned int len) 
	 */

	ret = fprog->len;

out:

	release_sock(sk);

	sockopt_release_sock(sk);

	return ret;

}