atm: convert to getsockopt_iter

Convert the ATM SVC and PVC sockets, along with the shared
vcc_getsockopt() helper, to use the new getsockopt_iter callback with
sockopt_t.

Key changes:
- Replace (char __user *optval, int __user *optlen) with sockopt_t *opt
- Use opt->optlen for buffer length (input)
- Use copy_to_iter() instead of put_user()/copy_to_user()

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20260520-getsock_four-v3-2-b8c0b16b7780@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 22 insertions, 19 deletions

diff --git a/net/atm/common.c b/net/atm/common.c
index fe77f51f6ce1..60132de4eebe 100644
--- a/net/atm/common.c
+++ b/net/atm/common.c
@@ -23,6 +23,7 @@
 #include <net/sock.h>		/* struct sock */
 #include <linux/uaccess.h>
 #include <linux/poll.h>
+#include <linux/uio.h>
 
 #include <linux/atomic.h>
 
@@ -797,13 +798,13 @@ int vcc_setsockopt(struct socket *sock, int level, int optname,
 }
 
 int vcc_getsockopt(struct socket *sock, int level, int optname,
-		   char __user *optval, int __user *optlen)
+		   sockopt_t *opt)
 {
 	struct atm_vcc *vcc;
+	int val;
 	int len;
 
-	if (get_user(len, optlen))
-		return -EFAULT;
+	len = opt->optlen;
 	if (__SO_LEVEL_MATCH(optname, level) && len != __SO_SIZE(optname))
 		return -EINVAL;
 
@@ -812,11 +813,13 @@ int vcc_getsockopt(struct socket *sock, int level, int optname,
 	case SO_ATMQOS:
 		if (!test_bit(ATM_VF_HASQOS, &vcc->flags))
 			return -EINVAL;
-		return copy_to_user(optval, &vcc->qos, sizeof(vcc->qos))
+		return copy_to_iter(&vcc->qos, sizeof(vcc->qos),
+				    &opt->iter_out) != sizeof(vcc->qos)
 			? -EFAULT : 0;
 	case SO_SETCLP:
-		return put_user(vcc->atm_options & ATM_ATMOPT_CLP ? 1 : 0,
-				(unsigned long __user *)optval) ? -EFAULT : 0;
+		val = vcc->atm_options & ATM_ATMOPT_CLP ? 1 : 0;
+		return copy_to_iter(&val, sizeof(val), &opt->iter_out) !=
+		       sizeof(val) ? -EFAULT : 0;
 	case SO_ATMPVC:
 	{
 		struct sockaddr_atmpvc pvc;
@@ -828,7 +831,8 @@ int vcc_getsockopt(struct socket *sock, int level, int optname,
 		pvc.sap_addr.itf = vcc->dev->number;
 		pvc.sap_addr.vpi = vcc->vpi;
 		pvc.sap_addr.vci = vcc->vci;
-		return copy_to_user(optval, &pvc, sizeof(pvc)) ? -EFAULT : 0;
+		return copy_to_iter(&pvc, sizeof(pvc), &opt->iter_out) !=
+		       sizeof(pvc) ? -EFAULT : 0;
 	}
 	default:
 		return -EINVAL;
diff --git a/net/atm/common.h b/net/atm/common.h
index a1e56e8de698..ae4502abf028 100644
--- a/net/atm/common.h
+++ b/net/atm/common.h
@@ -23,7 +23,7 @@ int vcc_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
 int vcc_setsockopt(struct socket *sock, int level, int optname,
 		   sockptr_t optval, unsigned int optlen);
 int vcc_getsockopt(struct socket *sock, int level, int optname,
-		   char __user *optval, int __user *optlen);
+		   sockopt_t *opt);
 void vcc_process_recv_queue(struct atm_vcc *vcc);
 
 int atmpvc_init(void);
diff --git a/net/atm/pvc.c b/net/atm/pvc.c
index 8f5e76f5dd9e..8b2c3e515601 100644
--- a/net/atm/pvc.c
+++ b/net/atm/pvc.c
@@ -75,13 +75,13 @@ static int pvc_setsockopt(struct socket *sock, int level, int optname,
 }
 
 static int pvc_getsockopt(struct socket *sock, int level, int optname,
-			  char __user *optval, int __user *optlen)
+			  sockopt_t *opt)
 {
 	struct sock *sk = sock->sk;
 	int error;
 
 	lock_sock(sk);
-	error = vcc_getsockopt(sock, level, optname, optval, optlen);
+	error = vcc_getsockopt(sock, level, optname, opt);
 	release_sock(sk);
 	return error;
 }
@@ -122,7 +122,7 @@ static const struct proto_ops pvc_proto_ops = {
 	.listen =	sock_no_listen,
 	.shutdown =	pvc_shutdown,
 	.setsockopt =	pvc_setsockopt,
-	.getsockopt =	pvc_getsockopt,
+	.getsockopt_iter = pvc_getsockopt,
 	.sendmsg =	vcc_sendmsg,
 	.recvmsg =	vcc_recvmsg,
 	.mmap =		sock_no_mmap,
diff --git a/net/atm/svc.c b/net/atm/svc.c
index 005964250ecd..7c5559f50a99 100644
--- a/net/atm/svc.c
+++ b/net/atm/svc.c
@@ -21,6 +21,7 @@
 #include <linux/bitops.h>
 #include <net/sock.h>		/* for sock_no_* */
 #include <linux/uaccess.h>
+#include <linux/uio.h>
 #include <linux/export.h>
 
 #include "resources.h"
@@ -501,25 +502,23 @@ out:
 }
 
 static int svc_getsockopt(struct socket *sock, int level, int optname,
-			  char __user *optval, int __user *optlen)
+			  sockopt_t *opt)
 {
 	struct sock *sk = sock->sk;
 	int error = 0, len;
 
 	lock_sock(sk);
 	if (!__SO_LEVEL_MATCH(optname, level) || optname != SO_ATMSAP) {
-		error = vcc_getsockopt(sock, level, optname, optval, optlen);
-		goto out;
-	}
-	if (get_user(len, optlen)) {
-		error = -EFAULT;
+		error = vcc_getsockopt(sock, level, optname, opt);
 		goto out;
 	}
+	len = opt->optlen;
 	if (len != sizeof(struct atm_sap)) {
 		error = -EINVAL;
 		goto out;
 	}
-	if (copy_to_user(optval, &ATM_SD(sock)->sap, sizeof(struct atm_sap))) {
+	if (copy_to_iter(&ATM_SD(sock)->sap, sizeof(struct atm_sap),
+			 &opt->iter_out) != sizeof(struct atm_sap)) {
 		error = -EFAULT;
 		goto out;
 	}
@@ -650,7 +649,7 @@ static const struct proto_ops svc_proto_ops = {
 	.listen =	svc_listen,
 	.shutdown =	svc_shutdown,
 	.setsockopt =	svc_setsockopt,
-	.getsockopt =	svc_getsockopt,
+	.getsockopt_iter = svc_getsockopt,
 	.sendmsg =	vcc_sendmsg,
 	.recvmsg =	vcc_recvmsg,
 	.mmap =		sock_no_mmap,