[PATCH net-next v2 0/5] net: convert four more protocols to getsockopt_iter

[PATCH net-next v2 0/5] net: convert four more protocols to getsockopt_iter

[Breno Leitao]

Continue the work to convert protocols to the new getsockopt_iter API.

Convert four additional getsockopt implementations to the new
sockopt_t/getsockopt_iter callback:

  - MCTP
  - LLC
  - X.25
  - KCM

These are mechanical, ABI-preserving conversions following the same
pattern as the previously converted protocols (af_packet, can/raw,
af_netlink, af_vsock): the (char __user *optval, int __user *optlen)
pair is replaced with a single sockopt_t *opt that carries the buffer
length on input and the returned size on output, and exposes an iov_iter
for the copy-out path. put_user()/copy_to_user() pairs are replaced with
a single copy_to_iter() per option, and the wrapper in
do_sock_getsockopt() handles writing optlen back to userspace.

I picked these four because each is small and self-contained.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
Changes in v2:
- Fix kdoc as suggested by Jakub.
- Drop the CAN patches; they will be sent separately through the
  linux-can tree.
- Add X.25 and KCM conversions, keeping the series at four protocols.
- Link to v1: https://patch.msgid.link/20260505-getsock_two-v1-0-4cb0738950e0@debian.org

---
Breno Leitao (5):
      mctp: convert to getsockopt_iter
      llc: convert to getsockopt_iter
      x25: convert to getsockopt_iter
      kcm: convert to getsockopt_iter
      selftests: net: getsockopt_iter: cleanup

 net/kcm/kcmsock.c                             |  16 ++--
 net/llc/af_llc.c                              |  18 ++---
 net/mctp/af_mctp.c                            |  10 +--
 net/x25/af_x25.c                              |  16 ++--
 tools/testing/selftests/net/getsockopt_iter.c | 109 +++++++++++++++++++++++---
 5 files changed, 124 insertions(+), 45 deletions(-)
---
base-commit: c1e5127b577c6b88fa48e532616932ae978528d5
change-id: 20260505-getsock_two-abad19643336

Best regards,
--  
Breno Leitao <leitao@debian.org>

[PATCH net-next v2 1/5] mctp: convert to getsockopt_iter

[Breno Leitao]

Convert MCTP socket's getsockopt implementation 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 copy_to_user()
- Add linux/uio.h for copy_to_iter()

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 net/mctp/af_mctp.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c
index 209a963112e3a..8af5e2b3c8d12 100644
--- a/net/mctp/af_mctp.c
+++ b/net/mctp/af_mctp.c
@@ -12,6 +12,7 @@
 #include <linux/mctp.h>
 #include <linux/module.h>
 #include <linux/socket.h>
+#include <linux/uio.h>
 
 #include <net/mctp.h>
 #include <net/mctpdevice.h>
@@ -405,7 +406,7 @@ static int mctp_setsockopt(struct socket *sock, int level, int optname,
 }
 
 static int mctp_getsockopt(struct socket *sock, int level, int optname,
-			   char __user *optval, int __user *optlen)
+			   sockopt_t *opt)
 {
 	struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
 	int len, val;
@@ -413,14 +414,13 @@ static int mctp_getsockopt(struct socket *sock, int level, int optname,
 	if (level != SOL_MCTP)
 		return -EINVAL;
 
-	if (get_user(len, optlen))
-		return -EFAULT;
+	len = opt->optlen;
 
 	if (optname == MCTP_OPT_ADDR_EXT) {
 		if (len != sizeof(int))
 			return -EINVAL;
 		val = !!msk->addr_ext;
-		if (copy_to_user(optval, &val, len))
+		if (copy_to_iter(&val, len, &opt->iter_out) != len)
 			return -EFAULT;
 		return 0;
 	}
@@ -639,7 +639,7 @@ static const struct proto_ops mctp_dgram_ops = {
 	.listen		= sock_no_listen,
 	.shutdown	= sock_no_shutdown,
 	.setsockopt	= mctp_setsockopt,
-	.getsockopt	= mctp_getsockopt,
+	.getsockopt_iter = mctp_getsockopt,
 	.sendmsg	= mctp_sendmsg,
 	.recvmsg	= mctp_recvmsg,
 	.mmap		= sock_no_mmap,

-- 
2.52.0

[PATCH net-next v2 2/5] llc: convert to getsockopt_iter

[Breno Leitao]

Convert LLC socket's getsockopt implementation 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) and returned size (output)
- Use copy_to_iter() instead of put_user()/copy_to_user()
- Add linux/uio.h for copy_to_iter()

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 net/llc/af_llc.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c
index 1b210db3119e8..35278c519a305 100644
--- a/net/llc/af_llc.c
+++ b/net/llc/af_llc.c
@@ -27,6 +27,7 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/sched/signal.h>
+#include <linux/uio.h>
 
 #include <net/llc.h>
 #include <net/llc_sap.h>
@@ -1166,25 +1167,21 @@ static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
  *	@sock: Socket to get information from.
  *	@level: Socket level user is requesting operations on.
  *	@optname: Operation name.
- *	@optval: Variable to return operation data in.
- *	@optlen: Length of optval.
+ *	@opt: sockopt context with iterator and length for returning data.
  *
  *	Get connection specific socket information.
  */
 static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
-			     char __user *optval, int __user *optlen)
+			     sockopt_t *opt)
 {
 	struct sock *sk = sock->sk;
 	struct llc_sock *llc = llc_sk(sk);
-	int val = 0, len = 0, rc = -EINVAL;
+	int val = 0, len, rc = -EINVAL;
 
 	lock_sock(sk);
 	if (unlikely(level != SOL_LLC))
 		goto out;
-	rc = get_user(len, optlen);
-	if (rc)
-		goto out;
-	rc = -EINVAL;
+	len = opt->optlen;
 	if (len != sizeof(int))
 		goto out;
 	switch (optname) {
@@ -1212,7 +1209,8 @@ static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
 		goto out;
 	}
 	rc = 0;
-	if (put_user(len, optlen) || copy_to_user(optval, &val, len))
+	opt->optlen = len;
+	if (copy_to_iter(&val, len, &opt->iter_out) != len)
 		rc = -EFAULT;
 out:
 	release_sock(sk);
@@ -1239,7 +1237,7 @@ static const struct proto_ops llc_ui_ops = {
 	.listen      = llc_ui_listen,
 	.shutdown    = llc_ui_shutdown,
 	.setsockopt  = llc_ui_setsockopt,
-	.getsockopt  = llc_ui_getsockopt,
+	.getsockopt_iter = llc_ui_getsockopt,
 	.sendmsg     = llc_ui_sendmsg,
 	.recvmsg     = llc_ui_recvmsg,
 	.mmap	     = sock_no_mmap,

-- 
2.52.0

[PATCH net-next v2 3/5] x25: convert to getsockopt_iter

[Breno Leitao]

Convert X.25 socket's getsockopt implementation 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) and returned size (output)
- Use copy_to_iter() instead of put_user()/copy_to_user()
- Add linux/uio.h for copy_to_iter()

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 net/x25/af_x25.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index af8762b24039d..c31d2af5dd223 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -53,6 +53,7 @@
 #include <linux/init.h>
 #include <linux/compat.h>
 #include <linux/ctype.h>
+#include <linux/uio.h>
 
 #include <net/x25.h>
 #include <net/compat.h>
@@ -448,7 +449,7 @@ static int x25_setsockopt(struct socket *sock, int level, int optname,
 }
 
 static int x25_getsockopt(struct socket *sock, int level, int optname,
-			  char __user *optval, int __user *optlen)
+			  sockopt_t *opt)
 {
 	struct sock *sk = sock->sk;
 	int val, len, rc = -ENOPROTOOPT;
@@ -456,22 +457,17 @@ static int x25_getsockopt(struct socket *sock, int level, int optname,
 	if (level != SOL_X25 || optname != X25_QBITINCL)
 		goto out;
 
-	rc = -EFAULT;
-	if (get_user(len, optlen))
-		goto out;
+	len = opt->optlen;
 
 	rc = -EINVAL;
 	if (len < 0)
 		goto out;
 
 	len = min_t(unsigned int, len, sizeof(int));
-
-	rc = -EFAULT;
-	if (put_user(len, optlen))
-		goto out;
+	opt->optlen = len;
 
 	val = test_bit(X25_Q_BIT_FLAG, &x25_sk(sk)->flags);
-	rc = copy_to_user(optval, &val, len) ? -EFAULT : 0;
+	rc = copy_to_iter(&val, len, &opt->iter_out) != len ? -EFAULT : 0;
 out:
 	return rc;
 }
@@ -1753,7 +1749,7 @@ static const struct proto_ops x25_proto_ops = {
 	.listen =	x25_listen,
 	.shutdown =	sock_no_shutdown,
 	.setsockopt =	x25_setsockopt,
-	.getsockopt =	x25_getsockopt,
+	.getsockopt_iter = x25_getsockopt,
 	.sendmsg =	x25_sendmsg,
 	.recvmsg =	x25_recvmsg,
 	.mmap =		sock_no_mmap,

-- 
2.52.0

[PATCH net-next v2 4/5] kcm: convert to getsockopt_iter

[Breno Leitao]

Convert KCM socket's getsockopt implementation 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) and returned size (output)
- Use copy_to_iter() instead of put_user()/copy_to_user()
- Add linux/uio.h for copy_to_iter()

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 net/kcm/kcmsock.c | 16 +++++++---------
 1 file changed, 7 insertions(+), 9 deletions(-)

diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c
index 3912e75079f5e..b273213cc68d1 100644
--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -24,6 +24,7 @@
 #include <linux/workqueue.h>
 #include <linux/syscalls.h>
 #include <linux/sched/signal.h>
+#include <linux/uio.h>
 
 #include <net/kcm.h>
 #include <net/netns/generic.h>
@@ -1167,7 +1168,7 @@ static int kcm_setsockopt(struct socket *sock, int level, int optname,
 }
 
 static int kcm_getsockopt(struct socket *sock, int level, int optname,
-			  char __user *optval, int __user *optlen)
+			  sockopt_t *opt)
 {
 	struct kcm_sock *kcm = kcm_sk(sock->sk);
 	int val, len;
@@ -1175,9 +1176,7 @@ static int kcm_getsockopt(struct socket *sock, int level, int optname,
 	if (level != SOL_KCM)
 		return -ENOPROTOOPT;
 
-	if (get_user(len, optlen))
-		return -EFAULT;
-
+	len = opt->optlen;
 	if (len < 0)
 		return -EINVAL;
 
@@ -1191,9 +1190,8 @@ static int kcm_getsockopt(struct socket *sock, int level, int optname,
 		return -ENOPROTOOPT;
 	}
 
-	if (put_user(len, optlen))
-		return -EFAULT;
-	if (copy_to_user(optval, &val, len))
+	opt->optlen = len;
+	if (copy_to_iter(&val, len, &opt->iter_out) != len)
 		return -EFAULT;
 	return 0;
 }
@@ -1755,7 +1753,7 @@ static const struct proto_ops kcm_dgram_ops = {
 	.listen =	sock_no_listen,
 	.shutdown =	sock_no_shutdown,
 	.setsockopt =	kcm_setsockopt,
-	.getsockopt =	kcm_getsockopt,
+	.getsockopt_iter = kcm_getsockopt,
 	.sendmsg =	kcm_sendmsg,
 	.recvmsg =	kcm_recvmsg,
 	.mmap =		sock_no_mmap,
@@ -1776,7 +1774,7 @@ static const struct proto_ops kcm_seqpacket_ops = {
 	.listen =	sock_no_listen,
 	.shutdown =	sock_no_shutdown,
 	.setsockopt =	kcm_setsockopt,
-	.getsockopt =	kcm_getsockopt,
+	.getsockopt_iter = kcm_getsockopt,
 	.sendmsg =	kcm_sendmsg,
 	.recvmsg =	kcm_recvmsg,
 	.mmap =		sock_no_mmap,

-- 
2.52.0

[PATCH net-next v2 5/5] selftests: net: getsockopt_iter: cleanup

[Breno Leitao]

Apply two cleanups suggested by Stanislav and bobby on the original
selftest series:

- Reorder local variable declarations into reverse christmas-tree
  order (longest line first). Because that ordering puts socklen_t
  optlen before the variable whose size it stores, the
  "optlen = sizeof(...)" initializer is moved out of the declaration
  to a plain assignment in the test body, as Stanislav suggested.

- Add ASSERT_EQ(optlen, ...) on every error path so the value the
  kernel writes back to the userspace optlen is pinned down even
  when the syscall returns -1. With do_sock_getsockopt() now writing
  opt->optlen back to userspace unconditionally, asserting that the
  netlink/vsock error paths leave the original input length untouched
  guards against future regressions.

Bobby Eshleman pointed out that
SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW/OLD return a sock_timeval-shaped
payload (16 bytes on 64-bit), which is wider than the u64 case
already covered. Add four tests that exercise this path:

- connect_timeout_new_exact         exact-size buffer
- connect_timeout_new_oversize_clamped  oversize buffer, clamped
- connect_timeout_new_undersize     undersize -> -EINVAL, optlen
                                    untouched
- connect_timeout_old_exact         exact-size buffer for OLD optname

Suggested-by: Stanislav Fomichev <sdf@fomichev.me>
Suggested-by: Bobby Eshleman <bobbyeshleman@meta.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
---
 tools/testing/selftests/net/getsockopt_iter.c | 109 +++++++++++++++++++++++---
 1 file changed, 98 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/net/getsockopt_iter.c b/tools/testing/selftests/net/getsockopt_iter.c
index 179f9e84926fd..209569354d0e3 100644
--- a/tools/testing/selftests/net/getsockopt_iter.c
+++ b/tools/testing/selftests/net/getsockopt_iter.c
@@ -22,6 +22,7 @@
 #include <unistd.h>
 #include <linux/netlink.h>
 #include <linux/rtnetlink.h>
+#include <linux/time_types.h>
 #include <linux/vm_sockets.h>
 #include <sys/socket.h>
 #include "kselftest_harness.h"
@@ -61,8 +62,10 @@ FIXTURE_TEARDOWN(netlink)
 
 TEST_F(netlink, pktinfo_exact)
 {
+	socklen_t optlen;
 	int val = -1;
-	socklen_t optlen = sizeof(val);
+
+	optlen = sizeof(val);
 
 	ASSERT_EQ(0, getsockopt(self->fd, SOL_NETLINK, NETLINK_PKTINFO,
 				&val, &optlen));
@@ -73,7 +76,9 @@ TEST_F(netlink, pktinfo_exact)
 TEST_F(netlink, pktinfo_oversize_clamped)
 {
 	char buf[16] = {};
-	socklen_t optlen = sizeof(buf);
+	socklen_t optlen;
+
+	optlen = sizeof(buf);
 
 	ASSERT_EQ(0, getsockopt(self->fd, SOL_NETLINK, NETLINK_PKTINFO,
 				buf, &optlen));
@@ -83,11 +88,14 @@ TEST_F(netlink, pktinfo_oversize_clamped)
 TEST_F(netlink, pktinfo_undersize)
 {
 	char buf[2] = {};
-	socklen_t optlen = sizeof(buf);
+	socklen_t optlen;
+
+	optlen = sizeof(buf);
 
 	ASSERT_EQ(-1, getsockopt(self->fd, SOL_NETLINK, NETLINK_PKTINFO,
 				 buf, &optlen));
 	ASSERT_EQ(EINVAL, errno);
+	ASSERT_EQ(sizeof(buf), optlen);
 }
 
 TEST_F(netlink, list_memberships_size_discovery)
@@ -105,7 +113,9 @@ TEST_F(netlink, list_memberships_size_discovery)
 TEST_F(netlink, list_memberships_full_read)
 {
 	__u32 buf[64] = {};
-	socklen_t optlen = sizeof(buf);
+	socklen_t optlen;
+
+	optlen = sizeof(buf);
 
 	ASSERT_EQ(0, getsockopt(self->fd, SOL_NETLINK,
 				NETLINK_LIST_MEMBERSHIPS,
@@ -117,22 +127,28 @@ TEST_F(netlink, list_memberships_full_read)
 
 TEST_F(netlink, bad_level)
 {
+	socklen_t optlen;
 	int val;
-	socklen_t optlen = sizeof(val);
+
+	optlen = sizeof(val);
 
 	ASSERT_EQ(-1, getsockopt(self->fd, SOL_SOCKET + 1, NETLINK_PKTINFO,
 				 &val, &optlen));
 	ASSERT_EQ(ENOPROTOOPT, errno);
+	ASSERT_EQ(sizeof(val), optlen);
 }
 
 TEST_F(netlink, bad_optname)
 {
+	socklen_t optlen;
 	int val;
-	socklen_t optlen = sizeof(val);
+
+	optlen = sizeof(val);
 
 	ASSERT_EQ(-1, getsockopt(self->fd, SOL_NETLINK, 0x7fff,
 				 &val, &optlen));
 	ASSERT_EQ(ENOPROTOOPT, errno);
+	ASSERT_EQ(sizeof(val), optlen);
 }
 
 /* ---------- vsock ---------- */
@@ -157,8 +173,10 @@ FIXTURE_TEARDOWN(vsock)
 
 TEST_F(vsock, buffer_size_exact)
 {
+	socklen_t optlen;
 	uint64_t val = 0;
-	socklen_t optlen = sizeof(val);
+
+	optlen = sizeof(val);
 
 	ASSERT_EQ(0, getsockopt(self->fd, AF_VSOCK,
 				SO_VM_SOCKETS_BUFFER_SIZE,
@@ -170,7 +188,9 @@ TEST_F(vsock, buffer_size_exact)
 TEST_F(vsock, buffer_size_oversize_clamped)
 {
 	char buf[16] = {};
-	socklen_t optlen = sizeof(buf);
+	socklen_t optlen;
+
+	optlen = sizeof(buf);
 
 	ASSERT_EQ(0, getsockopt(self->fd, AF_VSOCK,
 				SO_VM_SOCKETS_BUFFER_SIZE,
@@ -181,33 +201,100 @@ TEST_F(vsock, buffer_size_oversize_clamped)
 TEST_F(vsock, buffer_size_undersize)
 {
 	char buf[4] = {};
-	socklen_t optlen = sizeof(buf);
+	socklen_t optlen;
+
+	optlen = sizeof(buf);
 
 	ASSERT_EQ(-1, getsockopt(self->fd, AF_VSOCK,
 				 SO_VM_SOCKETS_BUFFER_SIZE,
 				 buf, &optlen));
 	ASSERT_EQ(EINVAL, errno);
+	ASSERT_EQ(sizeof(buf), optlen);
 }
 
 TEST_F(vsock, bad_level)
 {
+	socklen_t optlen;
 	uint64_t val;
-	socklen_t optlen = sizeof(val);
+
+	optlen = sizeof(val);
 
 	ASSERT_EQ(-1, getsockopt(self->fd, SOL_SOCKET + 1,
 				 SO_VM_SOCKETS_BUFFER_SIZE,
 				 &val, &optlen));
 	ASSERT_EQ(ENOPROTOOPT, errno);
+	ASSERT_EQ(sizeof(val), optlen);
 }
 
 TEST_F(vsock, bad_optname)
 {
+	socklen_t optlen;
 	uint64_t val;
-	socklen_t optlen = sizeof(val);
+
+	optlen = sizeof(val);
 
 	ASSERT_EQ(-1, getsockopt(self->fd, AF_VSOCK, 0x7fff,
 				 &val, &optlen));
 	ASSERT_EQ(ENOPROTOOPT, errno);
+	ASSERT_EQ(sizeof(val), optlen);
+}
+
+/* SO_VM_SOCKETS_CONNECT_TIMEOUT_{NEW,OLD} return a sock_timeval-shaped
+ * payload, which is wider than u64 on 64-bit. They exercise the path
+ * where the protocol's reported lv (16 bytes) is larger than the
+ * common 8-byte u64 case covered above.
+ */
+TEST_F(vsock, connect_timeout_new_exact)
+{
+	struct __kernel_sock_timeval tv = {};
+	socklen_t optlen;
+
+	optlen = sizeof(tv);
+
+	ASSERT_EQ(0, getsockopt(self->fd, AF_VSOCK,
+				SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW,
+				&tv, &optlen));
+	ASSERT_EQ(sizeof(tv), optlen);
+}
+
+TEST_F(vsock, connect_timeout_new_oversize_clamped)
+{
+	char buf[sizeof(struct __kernel_sock_timeval) * 2] = {};
+	socklen_t optlen;
+
+	optlen = sizeof(buf);
+
+	ASSERT_EQ(0, getsockopt(self->fd, AF_VSOCK,
+				SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW,
+				buf, &optlen));
+	ASSERT_EQ(sizeof(struct __kernel_sock_timeval), optlen);
+}
+
+TEST_F(vsock, connect_timeout_new_undersize)
+{
+	socklen_t optlen;
+	uint64_t val;
+
+	optlen = sizeof(val);
+
+	ASSERT_EQ(-1, getsockopt(self->fd, AF_VSOCK,
+				 SO_VM_SOCKETS_CONNECT_TIMEOUT_NEW,
+				 &val, &optlen));
+	ASSERT_EQ(EINVAL, errno);
+	ASSERT_EQ(sizeof(val), optlen);
+}
+
+TEST_F(vsock, connect_timeout_old_exact)
+{
+	struct __kernel_old_timeval tv = {};
+	socklen_t optlen;
+
+	optlen = sizeof(tv);
+
+	ASSERT_EQ(0, getsockopt(self->fd, AF_VSOCK,
+				SO_VM_SOCKETS_CONNECT_TIMEOUT_OLD,
+				&tv, &optlen));
+	ASSERT_EQ(sizeof(tv), optlen);
 }
 
 TEST_HARNESS_MAIN

-- 
2.52.0

Re: [PATCH net-next v2 1/5] mctp: convert to getsockopt_iter

[Adam Young]

Why is this 1/5 and where are the other 4?

On 5/7/26 06:57, Breno Leitao wrote:
> Convert MCTP socket's getsockopt implementation 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 copy_to_user()
> - Add linux/uio.h for copy_to_iter()
>
> Signed-off-by: Breno Leitao <leitao@debian.org>
> ---
>   net/mctp/af_mctp.c | 10 +++++-----
>   1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c
> index 209a963112e3a..8af5e2b3c8d12 100644
> --- a/net/mctp/af_mctp.c
> +++ b/net/mctp/af_mctp.c
> @@ -12,6 +12,7 @@
>   #include <linux/mctp.h>
>   #include <linux/module.h>
>   #include <linux/socket.h>
> +#include <linux/uio.h>
>   
>   #include <net/mctp.h>
>   #include <net/mctpdevice.h>
> @@ -405,7 +406,7 @@ static int mctp_setsockopt(struct socket *sock, int level, int optname,
>   }
>   
>   static int mctp_getsockopt(struct socket *sock, int level, int optname,
> -			   char __user *optval, int __user *optlen)
> +			   sockopt_t *opt)
>   {
>   	struct mctp_sock *msk = container_of(sock->sk, struct mctp_sock, sk);
>   	int len, val;
> @@ -413,14 +414,13 @@ static int mctp_getsockopt(struct socket *sock, int level, int optname,
>   	if (level != SOL_MCTP)
>   		return -EINVAL;
>   
> -	if (get_user(len, optlen))
> -		return -EFAULT;
> +	len = opt->optlen;
>   
>   	if (optname == MCTP_OPT_ADDR_EXT) {
>   		if (len != sizeof(int))
>   			return -EINVAL;
>   		val = !!msk->addr_ext;
> -		if (copy_to_user(optval, &val, len))
> +		if (copy_to_iter(&val, len, &opt->iter_out) != len)
>   			return -EFAULT;
>   		return 0;
>   	}
> @@ -639,7 +639,7 @@ static const struct proto_ops mctp_dgram_ops = {
>   	.listen		= sock_no_listen,
>   	.shutdown	= sock_no_shutdown,
>   	.setsockopt	= mctp_setsockopt,
> -	.getsockopt	= mctp_getsockopt,
> +	.getsockopt_iter = mctp_getsockopt,
>   	.sendmsg	= mctp_sendmsg,
>   	.recvmsg	= mctp_recvmsg,
>   	.mmap		= sock_no_mmap,
>

Re: [PATCH net-next v2 1/5] mctp: convert to getsockopt_iter

[Breno Leitao]

Hello Adam,

On Thu, May 07, 2026 at 04:10:36PM -0400, Adam Young wrote:
> Why is this 1/5 and where are the other 4?

The entire series was sent as one submission, and I've verified that all
recipients received the complete patchset. Did you not receive the other
patches?

You can find the full patchset here on lore:
https://lore.kernel.org/all/20260507-getsock_two-v2-0-5873111d9c12@debian.org/

Re: [PATCH net-next v2 0/5] net: convert four more protocols to getsockopt_iter

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 07 May 2026 03:57:49 -0700 you wrote:
> Continue the work to convert protocols to the new getsockopt_iter API.
> 
> Convert four additional getsockopt implementations to the new
> sockopt_t/getsockopt_iter callback:
> 
>   - MCTP
>   - LLC
>   - X.25
>   - KCM
> 
> [...]

Here is the summary with links:
  - [net-next,v2,1/5] mctp: convert to getsockopt_iter
    https://git.kernel.org/netdev/net-next/c/85f22f66f303
  - [net-next,v2,2/5] llc: convert to getsockopt_iter
    https://git.kernel.org/netdev/net-next/c/e0a917bca147
  - [net-next,v2,3/5] x25: convert to getsockopt_iter
    https://git.kernel.org/netdev/net-next/c/447edcb0e4be
  - [net-next,v2,4/5] kcm: convert to getsockopt_iter
    https://git.kernel.org/netdev/net-next/c/8aaaa32a7965
  - [net-next,v2,5/5] selftests: net: getsockopt_iter: cleanup
    https://git.kernel.org/netdev/net-next/c/c8c2bd2bcf67

You are awesome, thank you!
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