* [PATCH RESEND v2 1/2] nfc: llcp: widen getsockopt value locals to u32
2026-11-09 13:50 [PATCH RESEND v2 0/2] nfc: llcp: Move to .getsockopt_iter Breno Leitao
@ 2026-11-09 13:50 ` Breno Leitao
2026-11-09 13:50 ` [PATCH RESEND v2 2/2] nfc: llcp: convert to getsockopt_iter Breno Leitao
1 sibling, 0 replies; 3+ messages in thread
From: Breno Leitao @ 2026-11-09 13:50 UTC (permalink / raw)
To: David Heidelberg, David S. Miller, Jakub Kicinski, Paolo Abeni,
Simon Horman, Eric Dumazet, Eric Dumazet
Cc: oe-linux-nfc, netdev, linux-kernel, sdf.kernel, Breno Leitao,
kernel-team
nfc_llcp_getsockopt() returns each option as a u32 (written through a
(u32 __user *) cast), but the temporary variables are smaller than that,
and they are promoted at write side, example:
u8 rw;
put_user(rw, (u32 __user *) optval)
That is fine, but I want to widen the rw/miux/remote_miu locals from
u8/u16 to u32 so the following getsockopt_iter conversion can pass their
address to copy_to_iter(), which expects an object of the exact width.
No functional change.
PS: I am sending this as a separated patch to make sure this conversion
explicitly reviewable.
Signed-off-by: Breno Leitao <leitao@debian.org>
---
net/nfc/llcp_sock.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c
index 1e5ee4bcde684f..adb6e06229b4af 100644
--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -308,8 +308,7 @@ static int nfc_llcp_getsockopt(struct socket *sock, int level, int optname,
struct sock *sk = sock->sk;
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
int len, err = 0;
- u16 miux, remote_miu;
- u8 rw;
+ u32 miux, remote_miu, rw;
pr_debug("%p optname %d\n", sk, optname);
--
2.53.0-Meta
^ permalink raw reply [flat|nested] 3+ messages in thread* [PATCH RESEND v2 2/2] nfc: llcp: convert to getsockopt_iter
2026-11-09 13:50 [PATCH RESEND v2 0/2] nfc: llcp: Move to .getsockopt_iter Breno Leitao
2026-11-09 13:50 ` [PATCH RESEND v2 1/2] nfc: llcp: widen getsockopt value locals to u32 Breno Leitao
@ 2026-11-09 13:50 ` Breno Leitao
1 sibling, 0 replies; 3+ messages in thread
From: Breno Leitao @ 2026-11-09 13:50 UTC (permalink / raw)
To: David Heidelberg, David S. Miller, Jakub Kicinski, Paolo Abeni,
Simon Horman, Eric Dumazet, Eric Dumazet
Cc: oe-linux-nfc, netdev, linux-kernel, sdf.kernel, Breno Leitao,
kernel-team
Convert nfc_llcp_getsockopt() to the getsockopt_iter proto_ops callback.
It takes a sockopt_t and writes each value with copy_to_iter() instead of
a put_user() into optval; the socket layer builds the sockopt_t and copies
the length back. The socket lock and optlen validation are unchanged.
No functional change.
Signed-off-by: Breno Leitao <leitao@debian.org>
---
net/nfc/llcp_sock.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c
index adb6e06229b4af..8323a0e6a02ea3 100644
--- a/net/nfc/llcp_sock.c
+++ b/net/nfc/llcp_sock.c
@@ -302,21 +302,20 @@ static int nfc_llcp_setsockopt(struct socket *sock, int level, int optname,
}
static int nfc_llcp_getsockopt(struct socket *sock, int level, int optname,
- char __user *optval, int __user *optlen)
+ sockopt_t *opt)
{
struct nfc_llcp_local *local;
struct sock *sk = sock->sk;
struct nfc_llcp_sock *llcp_sock = nfc_llcp_sock(sk);
+ u32 miux, remote_miu, remote_lto, remote_rw, rw;
int len, err = 0;
- u32 miux, remote_miu, rw;
pr_debug("%p optname %d\n", sk, optname);
if (level != SOL_NFC)
return -ENOPROTOOPT;
- if (get_user(len, optlen))
- return -EFAULT;
+ len = opt->optlen;
if (len < 0)
return -EINVAL;
@@ -337,7 +336,7 @@ static int nfc_llcp_getsockopt(struct socket *sock, int level, int optname,
switch (optname) {
case NFC_LLCP_RW:
rw = llcp_sock->rw > LLCP_MAX_RW ? local->rw : llcp_sock->rw;
- if (put_user(rw, (u32 __user *) optval))
+ if (copy_to_iter(&rw, len, &opt->iter_out) != len)
err = -EFAULT;
break;
@@ -346,7 +345,7 @@ static int nfc_llcp_getsockopt(struct socket *sock, int level, int optname,
miux = be16_to_cpu(llcp_sock->miux) > LLCP_MAX_MIUX ?
be16_to_cpu(local->miux) : be16_to_cpu(llcp_sock->miux);
- if (put_user(miux, (u32 __user *) optval))
+ if (copy_to_iter(&miux, len, &opt->iter_out) != len)
err = -EFAULT;
break;
@@ -355,19 +354,21 @@ static int nfc_llcp_getsockopt(struct socket *sock, int level, int optname,
remote_miu = llcp_sock->remote_miu > LLCP_MAX_MIU ?
local->remote_miu : llcp_sock->remote_miu;
- if (put_user(remote_miu, (u32 __user *) optval))
+ if (copy_to_iter(&remote_miu, len, &opt->iter_out) != len)
err = -EFAULT;
break;
case NFC_LLCP_REMOTE_LTO:
- if (put_user(local->remote_lto / 10, (u32 __user *) optval))
+ remote_lto = local->remote_lto / 10;
+ if (copy_to_iter(&remote_lto, len, &opt->iter_out) != len)
err = -EFAULT;
break;
case NFC_LLCP_REMOTE_RW:
- if (put_user(llcp_sock->remote_rw, (u32 __user *) optval))
+ remote_rw = llcp_sock->remote_rw;
+ if (copy_to_iter(&remote_rw, len, &opt->iter_out) != len)
err = -EFAULT;
break;
@@ -379,8 +380,7 @@ static int nfc_llcp_getsockopt(struct socket *sock, int level, int optname,
release_sock(sk);
- if (put_user(len, optlen))
- return -EFAULT;
+ opt->optlen = len;
return err;
}
@@ -966,7 +966,7 @@ static const struct proto_ops llcp_sock_ops = {
.listen = llcp_sock_listen,
.shutdown = sock_no_shutdown,
.setsockopt = nfc_llcp_setsockopt,
- .getsockopt = nfc_llcp_getsockopt,
+ .getsockopt_iter = nfc_llcp_getsockopt,
.sendmsg = llcp_sock_sendmsg,
.recvmsg = llcp_sock_recvmsg,
.mmap = sock_no_mmap,
--
2.53.0-Meta
^ permalink raw reply [flat|nested] 3+ messages in thread