[PATCH AUTOSEL 4.14 02/27] hv_netvsc: Fix a warning of suspicious RCU usage

[PATCH AUTOSEL 4.14 02/27] hv_netvsc: Fix a warning of suspicious RCU usage

[Sasha Levin]

From: Dexuan Cui <decui@microsoft.com>

[ Upstream commit 6d0d779dca73cd5acb649c54f81401f93098b298 ]

This fixes a warning of "suspicious rcu_dereference_check() usage"
when nload runs.

Fixes: 776e726bfb34 ("netvsc: fix RCU warning in get_stats")
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/hyperv/netvsc_drv.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index eb92720dd1c4a..33c1f6548fb79 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1170,12 +1170,15 @@ static void netvsc_get_stats64(struct net_device *net,
 			       struct rtnl_link_stats64 *t)
 {
 	struct net_device_context *ndev_ctx = netdev_priv(net);
-	struct netvsc_device *nvdev = rcu_dereference_rtnl(ndev_ctx->nvdev);
+	struct netvsc_device *nvdev;
 	struct netvsc_vf_pcpu_stats vf_tot;
 	int i;
 
+	rcu_read_lock();
+
+	nvdev = rcu_dereference(ndev_ctx->nvdev);
 	if (!nvdev)
-		return;
+		goto out;
 
 	netdev_stats_to_stats64(t, &net->stats);
 
@@ -1214,6 +1217,8 @@ static void netvsc_get_stats64(struct net_device *net,
 		t->rx_packets	+= packets;
 		t->multicast	+= multicast;
 	}
+out:
+	rcu_read_unlock();
 }
 
 static int netvsc_set_mac_addr(struct net_device *ndev, void *p)
-- 
2.20.1

[PATCH AUTOSEL 4.14 21/27] Input: hyperv-keyboard: Use in-place iterator API in the channel callback

[Sasha Levin]

From: Dexuan Cui <decui@microsoft.com>

[ Upstream commit d09bc83640d524b8467a660db7b1d15e6562a1de ]

Simplify the ring buffer handling with the in-place API.

Also avoid the dynamic allocation and the memory leak in the channel
callback function.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/input/serio/hyperv-keyboard.c | 35 +++++----------------------
 1 file changed, 6 insertions(+), 29 deletions(-)

diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c
index 55288a026e4e2..c137ffa6fdec8 100644
--- a/drivers/input/serio/hyperv-keyboard.c
+++ b/drivers/input/serio/hyperv-keyboard.c
@@ -245,40 +245,17 @@ static void hv_kbd_handle_received_packet(struct hv_device *hv_dev,
 
 static void hv_kbd_on_channel_callback(void *context)
 {
+	struct vmpacket_descriptor *desc;
 	struct hv_device *hv_dev = context;
-	void *buffer;
-	int bufferlen = 0x100; /* Start with sensible size */
 	u32 bytes_recvd;
 	u64 req_id;
-	int error;
 
-	buffer = kmalloc(bufferlen, GFP_ATOMIC);
-	if (!buffer)
-		return;
-
-	while (1) {
-		error = vmbus_recvpacket_raw(hv_dev->channel, buffer, bufferlen,
-					     &bytes_recvd, &req_id);
-		switch (error) {
-		case 0:
-			if (bytes_recvd == 0) {
-				kfree(buffer);
-				return;
-			}
-
-			hv_kbd_handle_received_packet(hv_dev, buffer,
-						      bytes_recvd, req_id);
-			break;
+	foreach_vmbus_pkt(desc, hv_dev->channel) {
+		bytes_recvd = desc->len8 * 8;
+		req_id = desc->trans_id;
 
-		case -ENOBUFS:
-			kfree(buffer);
-			/* Handle large packet */
-			bufferlen = bytes_recvd;
-			buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
-			if (!buffer)
-				return;
-			break;
-		}
+		hv_kbd_handle_received_packet(hv_dev, desc, bytes_recvd,
+					      req_id);
 	}
 }
 
-- 
2.20.1

[PATCH AUTOSEL 4.14 22/27] Tools: hv: kvp: eliminate 'may be used uninitialized' warning

[Sasha Levin]

From: Vitaly Kuznetsov <vkuznets@redhat.com>

[ Upstream commit 89eb4d8d25722a0a0194cf7fa47ba602e32a6da7 ]

When building hv_kvp_daemon GCC-8.3 complains:

hv_kvp_daemon.c: In function ‘kvp_get_ip_info.constprop’:
hv_kvp_daemon.c:812:30: warning: ‘ip_buffer’ may be used uninitialized in this function [-Wmaybe-uninitialized]
  struct hv_kvp_ipaddr_value *ip_buffer;

this seems to be a false positive: we only use ip_buffer when
op == KVP_OP_GET_IP_INFO and it is only unset when op == KVP_OP_ENUMERATE.

Silence the warning by initializing ip_buffer to NULL.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 tools/hv/hv_kvp_daemon.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c
index 62c9a503ae052..bb245d4afc0cf 100644
--- a/tools/hv/hv_kvp_daemon.c
+++ b/tools/hv/hv_kvp_daemon.c
@@ -867,7 +867,7 @@ kvp_get_ip_info(int family, char *if_name, int op,
 	int sn_offset = 0;
 	int error = 0;
 	char *buffer;
-	struct hv_kvp_ipaddr_value *ip_buffer;
+	struct hv_kvp_ipaddr_value *ip_buffer = NULL;
 	char cidr_mask[5]; /* /xyz */
 	int weight;
 	int i;
-- 
2.20.1