[v7,02/11] bpf: Add sockptr support for setsockopt

Message ID 20231016134750.1381153-3-leitao@debian.org
State New
Headers
Series io_uring: Initial support for {s,g}etsockopt commands |

Commit Message

Breno Leitao Oct. 16, 2023, 1:47 p.m. UTC
  The whole network stack uses sockptr, and while it doesn't move to
something more modern, let's use sockptr in setsockptr BPF hooks, so, it
could be used by other callers.

The main motivation for this change is to use it in the io_uring
{g,s}etsockopt(), which will use a userspace pointer for *optval, but, a
kernel value for optlen.

Link: https://lore.kernel.org/all/ZSArfLaaGcfd8LH8@gmail.com/

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 include/linux/bpf-cgroup.h | 2 +-
 kernel/bpf/cgroup.c        | 5 +++--
 net/socket.c               | 2 +-
 3 files changed, 5 insertions(+), 4 deletions(-)
  

Comments

Martin KaFai Lau Oct. 19, 2023, 7:32 p.m. UTC | #1
On 10/16/23 6:47 AM, Breno Leitao wrote:
> The whole network stack uses sockptr, and while it doesn't move to
> something more modern, let's use sockptr in setsockptr BPF hooks, so, it
> could be used by other callers.
> 
> The main motivation for this change is to use it in the io_uring
> {g,s}etsockopt(), which will use a userspace pointer for *optval, but, a
> kernel value for optlen.

Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
  

Patch

diff --git a/include/linux/bpf-cgroup.h b/include/linux/bpf-cgroup.h
index 7b55844f6ba7..2912dce9144e 100644
--- a/include/linux/bpf-cgroup.h
+++ b/include/linux/bpf-cgroup.h
@@ -143,7 +143,7 @@  int __cgroup_bpf_run_filter_sysctl(struct ctl_table_header *head,
 				   enum cgroup_bpf_attach_type atype);
 
 int __cgroup_bpf_run_filter_setsockopt(struct sock *sock, int *level,
-				       int *optname, char __user *optval,
+				       int *optname, sockptr_t optval,
 				       int *optlen, char **kernel_optval);
 
 int __cgroup_bpf_run_filter_getsockopt(struct sock *sk, int level,
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 97745f67ac15..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;
 	}
diff --git a/net/socket.c b/net/socket.c
index 6b47dd499218..28d3eb339514 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2305,7 +2305,7 @@  int __sys_setsockopt(int fd, int level, int optname, char __user *user_optval,
 
 	if (!in_compat_syscall())
 		err = BPF_CGROUP_RUN_PROG_SETSOCKOPT(sock->sk, &level, &optname,
-						     user_optval, &optlen,
+						     optval, &optlen,
 						     &kernel_optval);
 	if (err < 0)
 		goto out_put;