Merge tag 'for-6.7/io_uring-sockopt-2023-10-30' of git://git.kernel.dk/linux

Pull io_uring {get,set}sockopt support from Jens Axboe:
 "This adds support for using getsockopt and setsockopt via io_uring.

  The main use cases for this is to enable use of direct descriptors,
  rather than first instantiating a normal file descriptor, doing the
  option tweaking needed, then turning it into a direct descriptor. With
  this support, we can avoid needing a regular file descriptor
  completely.

  The net and bpf bits have been signed off on their side"

* tag 'for-6.7/io_uring-sockopt-2023-10-30' of git://git.kernel.dk/linux:
  selftests/bpf/sockopt: Add io_uring support
  io_uring/cmd: Introduce SOCKET_URING_OP_SETSOCKOPT
  io_uring/cmd: Introduce SOCKET_URING_OP_GETSOCKOPT
  io_uring/cmd: return -EOPNOTSUPP if net is disabled
  selftests/net: Extract uring helpers to be reusable
  tools headers: Grab copy of io_uring.h
  io_uring/cmd: Pass compat mode in issue_flags
  net/socket: Break down __sys_getsockopt
  net/socket: Break down __sys_setsockopt
  bpf: Add sockptr support for setsockopt
  bpf: Add sockptr support for getsockopt

1 files changed, 14 insertions, 11 deletions

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 74ad2215e1ba..491d20038cbe 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1800,7 +1800,7 @@ static bool sockopt_buf_allocated(struct bpf_sockopt_kern *ctx,
 }
 
 int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
-				       int *optname, char __user *optval,
+				       int *optname, sockptr_t optval,
 				       int *optlen, char **kernel_optval)
 {
 	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
@@ -1823,7 +1823,8 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
 
 	ctx.optlen = *optlen;
 
-	if (copy_from_user(ctx.optval, optval, min(*optlen, max_optlen)) != 0) {
+	if (copy_from_sockptr(ctx.optval, optval,
+			      min(*optlen, max_optlen))) {
 		ret = -EFAULT;
 		goto out;
 	}
@@ -1890,8 +1891,8 @@ out:
 }
 
 int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
-				       int optname, char __user *optval,
-				       int __user *optlen, int max_optlen,
+				       int optname, sockptr_t optval,
+				       sockptr_t optlen, int max_optlen,
 				       int retval)
 {
 	struct cgroup *cgrp = sock_cgroup_ptr(&sk->sk_cgrp_data);
@@ -1918,8 +1919,8 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
 		 * one that kernel returned as well to let
 		 * BPF programs inspect the value.
 		 */
-
-		if (get_user(ctx.optlen, optlen)) {
+		if (copy_from_sockptr(&ctx.optlen, optlen,
+				      sizeof(ctx.optlen))) {
 			ret = -EFAULT;
 			goto out;
 		}
@@ -1930,8 +1931,8 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
 		}
 		orig_optlen = ctx.optlen;
 
-		if (copy_from_user(ctx.optval, optval,
-				   min(ctx.optlen, max_optlen)) != 0) {
+		if (copy_from_sockptr(ctx.optval, optval,
+				      min(ctx.optlen, max_optlen))) {
 			ret = -EFAULT;
 			goto out;
 		}
@@ -1945,7 +1946,8 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
 	if (ret < 0)
 		goto out;
 
-	if (optval && (ctx.optlen > max_optlen || ctx.optlen < 0)) {
+	if (!sockptr_is_null(optval) &&
+	    (ctx.optlen > max_optlen || ctx.optlen < 0)) {
 		if (orig_optlen > PAGE_SIZE && ctx.optlen >= 0) {
 			pr_info_once("bpf getsockopt: ignoring program buffer with optlen=%d (max_optlen=%d)\n",
 				     ctx.optlen, max_optlen);
@@ -1957,11 +1959,12 @@ int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
 	}
 
 	if (ctx.optlen != 0) {
-		if (optval && copy_to_user(optval, ctx.optval, ctx.optlen)) {
+		if (!sockptr_is_null(optval) &&
+		    copy_to_sockptr(optval, ctx.optval, ctx.optlen)) {
 			ret = -EFAULT;
 			goto out;
 		}
-		if (put_user(ctx.optlen, optlen)) {
+		if (copy_to_sockptr(optlen, &ctx.optlen, sizeof(ctx.optlen))) {
 			ret = -EFAULT;
 			goto out;
 		}