Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/bluetooth/hidp/Kconfig b/net/bluetooth/hidp/Kconfig
index bc8610b..14100f3 100644
--- a/net/bluetooth/hidp/Kconfig
+++ b/net/bluetooth/hidp/Kconfig
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 config BT_HIDP
 	tristate "HIDP protocol support"
 	depends on BT_BREDR && INPUT
diff --git a/net/bluetooth/hidp/Makefile b/net/bluetooth/hidp/Makefile
index a9ee115..f41b0aa 100644
--- a/net/bluetooth/hidp/Makefile
+++ b/net/bluetooth/hidp/Makefile
@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Makefile for the Linux Bluetooth HIDP layer
 #
diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c
index 253975c..bef84b9 100644
--- a/net/bluetooth/hidp/core.c
+++ b/net/bluetooth/hidp/core.c
@@ -101,6 +101,7 @@
 {
 	struct sk_buff *skb;
 	struct sock *sk = sock->sk;
+	int ret;
 
 	BT_DBG("session %p data %p size %d", session, data, size);
 
@@ -114,13 +115,17 @@
 	}
 
 	skb_put_u8(skb, hdr);
-	if (data && size > 0)
+	if (data && size > 0) {
 		skb_put_data(skb, data, size);
+		ret = size;
+	} else {
+		ret = 0;
+	}
 
 	skb_queue_tail(transmit, skb);
 	wake_up_interruptible(sk_sleep(sk));
 
-	return 0;
+	return ret;
 }
 
 static int hidp_send_ctrl_message(struct hidp_session *session,
@@ -262,7 +267,7 @@
 	set_bit(HIDP_WAITING_FOR_RETURN, &session->flags);
 	data[0] = report_number;
 	ret = hidp_send_ctrl_message(session, report_type, data, 1);
-	if (ret)
+	if (ret < 0)
 		goto err;
 
 	/* Wait for the return of the report. The returned report
@@ -338,7 +343,7 @@
 	data[0] = reportnum;
 	set_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags);
 	ret = hidp_send_ctrl_message(session, report_type, data, count);
-	if (ret)
+	if (ret < 0)
 		goto err;
 
 	/* Wait for the ACK from the device. */
@@ -649,7 +654,7 @@
 }
 
 static int hidp_setup_input(struct hidp_session *session,
-				struct hidp_connadd_req *req)
+				const struct hidp_connadd_req *req)
 {
 	struct input_dev *input;
 	int i;
@@ -748,7 +753,7 @@
 /* This function sets up the hid device. It does not add it
    to the HID system. That is done in hidp_add_connection(). */
 static int hidp_setup_hid(struct hidp_session *session,
-				struct hidp_connadd_req *req)
+				const struct hidp_connadd_req *req)
 {
 	struct hid_device *hid;
 	int err;
@@ -775,7 +780,7 @@
 	hid->version = req->version;
 	hid->country = req->country;
 
-	strncpy(hid->name, req->name, sizeof(hid->name));
+	strscpy(hid->name, req->name, sizeof(hid->name));
 
 	snprintf(hid->phys, sizeof(hid->phys), "%pMR",
 		 &l2cap_pi(session->ctrl_sock->sk)->chan->src);
@@ -807,7 +812,7 @@
 
 /* initialize session devices */
 static int hidp_session_dev_init(struct hidp_session *session,
-				 struct hidp_connadd_req *req)
+				 const struct hidp_connadd_req *req)
 {
 	int ret;
 
@@ -906,7 +911,7 @@
 static int hidp_session_new(struct hidp_session **out, const bdaddr_t *bdaddr,
 			    struct socket *ctrl_sock,
 			    struct socket *intr_sock,
-			    struct hidp_connadd_req *req,
+			    const struct hidp_connadd_req *req,
 			    struct l2cap_conn *conn)
 {
 	struct hidp_session *session;
@@ -1074,6 +1079,10 @@
 static void hidp_session_terminate(struct hidp_session *session)
 {
 	atomic_inc(&session->terminate);
+	/*
+	 * See the comment preceding the call to wait_woken()
+	 * in hidp_session_run().
+	 */
 	wake_up_interruptible(&hidp_session_wq);
 }
 
@@ -1193,8 +1202,6 @@
 		 *    thread is woken up by ->sk_state_changed().
 		 */
 
-		/* Ensure session->terminate is updated */
-		smp_mb__before_atomic();
 		if (atomic_read(&session->terminate))
 			break;
 
@@ -1228,14 +1235,15 @@
 		hidp_process_transmit(session, &session->ctrl_transmit,
 				      session->ctrl_sock);
 
+		/*
+		 * wait_woken() performs the necessary memory barriers
+		 * for us; see the header comment for this primitive.
+		 */
 		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
 	}
 	remove_wait_queue(&hidp_session_wq, &wait);
 
 	atomic_inc(&session->terminate);
-
-	/* Ensure session->terminate is updated */
-	smp_mb__after_atomic();
 }
 
 static int hidp_session_wake_function(wait_queue_entry_t *wait,
@@ -1335,7 +1343,7 @@
 	return 0;
 }
 
-int hidp_connection_add(struct hidp_connadd_req *req,
+int hidp_connection_add(const struct hidp_connadd_req *req,
 			struct socket *ctrl_sock,
 			struct socket *intr_sock)
 {
diff --git a/net/bluetooth/hidp/hidp.h b/net/bluetooth/hidp/hidp.h
index 8798492..6ef88d0 100644
--- a/net/bluetooth/hidp/hidp.h
+++ b/net/bluetooth/hidp/hidp.h
@@ -122,7 +122,7 @@
 	struct hidp_conninfo __user *ci;
 };
 
-int hidp_connection_add(struct hidp_connadd_req *req, struct socket *ctrl_sock, struct socket *intr_sock);
+int hidp_connection_add(const struct hidp_connadd_req *req, struct socket *ctrl_sock, struct socket *intr_sock);
 int hidp_connection_del(struct hidp_conndel_req *req);
 int hidp_get_connlist(struct hidp_connlist_req *req);
 int hidp_get_conninfo(struct hidp_conninfo *ci);
diff --git a/net/bluetooth/hidp/sock.c b/net/bluetooth/hidp/sock.c
index 1eaac01..03be6a4 100644
--- a/net/bluetooth/hidp/sock.c
+++ b/net/bluetooth/hidp/sock.c
@@ -46,9 +46,8 @@
 	return 0;
 }
 
-static int hidp_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+static int do_hidp_sock_ioctl(struct socket *sock, unsigned int cmd, void __user *argp)
 {
-	void __user *argp = (void __user *) arg;
 	struct hidp_connadd_req ca;
 	struct hidp_conndel_req cd;
 	struct hidp_connlist_req cl;
@@ -57,7 +56,7 @@
 	struct socket *isock;
 	int err;
 
-	BT_DBG("cmd %x arg %lx", cmd, arg);
+	BT_DBG("cmd %x arg %p", cmd, argp);
 
 	switch (cmd) {
 	case HIDPCONNADD:
@@ -76,6 +75,7 @@
 			sockfd_put(csock);
 			return err;
 		}
+		ca.name[sizeof(ca.name)-1] = 0;
 
 		err = hidp_connection_add(&ca, csock, isock);
 		if (!err && copy_to_user(argp, &ca, sizeof(ca)))
@@ -122,6 +122,11 @@
 	return -EINVAL;
 }
 
+static int hidp_sock_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	return do_hidp_sock_ioctl(sock, cmd, (void __user *)arg);
+}
+
 #ifdef CONFIG_COMPAT
 struct compat_hidp_connadd_req {
 	int   ctrl_sock;	/* Connected control socket */
@@ -141,13 +146,15 @@
 
 static int hidp_sock_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 {
+	void __user *argp = compat_ptr(arg);
+	int err;
+
 	if (cmd == HIDPGETCONNLIST) {
 		struct hidp_connlist_req cl;
+		u32 __user *p = argp;
 		u32 uci;
-		int err;
 
-		if (get_user(cl.cnum, (u32 __user *) arg) ||
-				get_user(uci, (u32 __user *) (arg + 4)))
+		if (get_user(cl.cnum, p) || get_user(uci, p + 1))
 			return -EFAULT;
 
 		cl.ci = compat_ptr(uci);
@@ -157,39 +164,55 @@
 
 		err = hidp_get_connlist(&cl);
 
-		if (!err && put_user(cl.cnum, (u32 __user *) arg))
+		if (!err && put_user(cl.cnum, p))
 			err = -EFAULT;
 
 		return err;
 	} else if (cmd == HIDPCONNADD) {
-		struct compat_hidp_connadd_req ca;
-		struct hidp_connadd_req __user *uca;
+		struct compat_hidp_connadd_req ca32;
+		struct hidp_connadd_req ca;
+		struct socket *csock;
+		struct socket *isock;
 
-		uca = compat_alloc_user_space(sizeof(*uca));
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
 
-		if (copy_from_user(&ca, (void __user *) arg, sizeof(ca)))
+		if (copy_from_user(&ca32, (void __user *) arg, sizeof(ca32)))
 			return -EFAULT;
 
-		if (put_user(ca.ctrl_sock, &uca->ctrl_sock) ||
-				put_user(ca.intr_sock, &uca->intr_sock) ||
-				put_user(ca.parser, &uca->parser) ||
-				put_user(ca.rd_size, &uca->rd_size) ||
-				put_user(compat_ptr(ca.rd_data), &uca->rd_data) ||
-				put_user(ca.country, &uca->country) ||
-				put_user(ca.subclass, &uca->subclass) ||
-				put_user(ca.vendor, &uca->vendor) ||
-				put_user(ca.product, &uca->product) ||
-				put_user(ca.version, &uca->version) ||
-				put_user(ca.flags, &uca->flags) ||
-				put_user(ca.idle_to, &uca->idle_to) ||
-				copy_to_user(&uca->name[0], &ca.name[0], 128))
-			return -EFAULT;
+		ca.ctrl_sock = ca32.ctrl_sock;
+		ca.intr_sock = ca32.intr_sock;
+		ca.parser = ca32.parser;
+		ca.rd_size = ca32.rd_size;
+		ca.rd_data = compat_ptr(ca32.rd_data);
+		ca.country = ca32.country;
+		ca.subclass = ca32.subclass;
+		ca.vendor = ca32.vendor;
+		ca.product = ca32.product;
+		ca.version = ca32.version;
+		ca.flags = ca32.flags;
+		ca.idle_to = ca32.idle_to;
+		ca32.name[sizeof(ca32.name) - 1] = '\0';
+		memcpy(ca.name, ca32.name, 128);
 
-		arg = (unsigned long) uca;
+		csock = sockfd_lookup(ca.ctrl_sock, &err);
+		if (!csock)
+			return err;
 
-		/* Fall through. We don't actually write back any _changes_
-		   to the structure anyway, so there's no need to copy back
-		   into the original compat version */
+		isock = sockfd_lookup(ca.intr_sock, &err);
+		if (!isock) {
+			sockfd_put(csock);
+			return err;
+		}
+
+		err = hidp_connection_add(&ca, csock, isock);
+		if (!err && copy_to_user(argp, &ca32, sizeof(ca32)))
+			err = -EFAULT;
+
+		sockfd_put(csock);
+		sockfd_put(isock);
+
+		return err;
 	}
 
 	return hidp_sock_ioctl(sock, cmd, arg);