Commit 1985320c authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: net: Avoid do_ip_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 do_ip_getsockopt()
to use sockopt_{lock,release}_sock() such that a latter patch can
make bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt().

Signed-off-by: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002834.2891514-1-kafai@fb.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 728f064c

net/ipv4/ip_sockglue.c

+8 −8
Original line number Diff line number Diff line
@@ -1545,7 +1545,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, 


	if (needs_rtnl)

		rtnl_lock();

	lock_sock(sk);

	sockopt_lock_sock(sk);



	switch (optname) {

	case IP_OPTIONS:
@@ -1561,7 +1561,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, 
			memcpy(optbuf, &inet_opt->opt,

			       sizeof(struct ip_options) +

			       inet_opt->opt.optlen);

		release_sock(sk);

		sockopt_release_sock(sk);



		if (opt->optlen == 0) {

			len = 0;
@@ -1637,7 +1637,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, 
			dst_release(dst);

		}

		if (!val) {

			release_sock(sk);

			sockopt_release_sock(sk);

			return -ENOTCONN;

		}

		break;
@@ -1662,7 +1662,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, 
		struct in_addr addr;

		len = min_t(unsigned int, len, sizeof(struct in_addr));

		addr.s_addr = inet->mc_addr;

		release_sock(sk);

		sockopt_release_sock(sk);



		if (copy_to_sockptr(optlen, &len, sizeof(int)))

			return -EFAULT;
@@ -1699,7 +1699,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, 
	{

		struct msghdr msg;



		release_sock(sk);

		sockopt_release_sock(sk);



		if (sk->sk_type != SOCK_STREAM)

			return -ENOPROTOOPT;
@@ -1743,10 +1743,10 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, 
		val = inet->min_ttl;

		break;

	default:

		release_sock(sk);

		sockopt_release_sock(sk);

		return -ENOPROTOOPT;

	}

	release_sock(sk);

	sockopt_release_sock(sk);



	if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) {

		unsigned char ucval = (unsigned char)val;
@@ -1765,7 +1765,7 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, 
	return 0;



out:

	release_sock(sk);

	sockopt_release_sock(sk);

	if (needs_rtnl)

		rtnl_unlock();

	return err;