[PATCH net] hv_sock: Suppress bogus "may be used uninitialized" warnings

[PATCH net] hv_sock: Suppress bogus "may be used uninitialized" warnings

[Dexuan Cui]

gcc 8.2.0 may report these bogus warnings under some condition:

warning: ‘vnew’ may be used uninitialized in this function
warning: ‘hvs_new’ may be used uninitialized in this function

Actually, the 2 pointers are only initialized and used if the variable
"conn_from_host" is true. The code is not buggy here.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
---
 net/vmw_vsock/hyperv_transport.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index 8d1ea9eda8a2..cd3f47f54fa7 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -329,8 +329,8 @@ static void hvs_open_connection(struct vmbus_channel *chan)
 
 	struct sockaddr_vm addr;
 	struct sock *sk, *new = NULL;
-	struct vsock_sock *vnew;
-	struct hvsock *hvs, *hvs_new;
+	struct vsock_sock *vnew = NULL;
+	struct hvsock *hvs, *hvs_new = NULL;
 	int ret;
 
 	if_type = &chan->offermsg.offer.if_type;
-- 
2.19.1

RE: [PATCH net] hv_sock: Suppress bogus "may be used uninitialized" warnings

[Sunil Muthuswamy]

> -----Original Message-----
> From: linux-hyperv-owner@vger.kernel.org <linux-hyperv-owner@vger.kernel.org> On Behalf Of Dexuan Cui
> Sent: Friday, June 14, 2019 10:01 PM
> To: netdev@vger.kernel.org; davem@davemloft.net; Michael Kelley <mikelley@microsoft.com>
> Cc: linux-hyperv@vger.kernel.org; linux-kernel@vger.kernel.org; KY Srinivasan <kys@microsoft.com>; Stephen Hemminger
> <sthemmin@microsoft.com>; Haiyang Zhang <haiyangz@microsoft.com>; Sasha Levin <Alexander.Levin@microsoft.com>;
> olaf@aepfle.de; apw@canonical.com; jasowang@redhat.com; vkuznets <vkuznets@redhat.com>; marcelo.cerri@canonical.com;
> Dexuan Cui <decui@microsoft.com>
> Subject: [PATCH net] hv_sock: Suppress bogus "may be used uninitialized" warnings
> 
> gcc 8.2.0 may report these bogus warnings under some condition:
> 
> warning: ‘vnew’ may be used uninitialized in this function
> warning: ‘hvs_new’ may be used uninitialized in this function
> 
> Actually, the 2 pointers are only initialized and used if the variable
> "conn_from_host" is true. The code is not buggy here.
> 
> Signed-off-by: Dexuan Cui <decui@microsoft.com>
> ---
>  net/vmw_vsock/hyperv_transport.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
> index 8d1ea9eda8a2..cd3f47f54fa7 100644
> --- a/net/vmw_vsock/hyperv_transport.c
> +++ b/net/vmw_vsock/hyperv_transport.c
> @@ -329,8 +329,8 @@ static void hvs_open_connection(struct vmbus_channel *chan)
> 
>  	struct sockaddr_vm addr;
>  	struct sock *sk, *new = NULL;
> -	struct vsock_sock *vnew;
> -	struct hvsock *hvs, *hvs_new;
> +	struct vsock_sock *vnew = NULL;
> +	struct hvsock *hvs, *hvs_new = NULL;
>  	int ret;
> 
These are all already fixed under 
https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/commit/?id=ac383f58f3c98de37fa67452acc5bd677396e9f3 
Its just that that commit hasn't merged with the 'net' branch yet.
>  	if_type = &chan->offermsg.offer.if_type;
> --
> 2.19.1

Re: [PATCH net] hv_sock: Suppress bogus "may be used uninitialized" warnings

[David Miller]

From: Dexuan Cui <decui@microsoft.com>
Date: Sat, 15 Jun 2019 05:00:57 +0000

> gcc 8.2.0 may report these bogus warnings under some condition:
> 
> warning: ‘vnew’ may be used uninitialized in this function
> warning: ‘hvs_new’ may be used uninitialized in this function
> 
> Actually, the 2 pointers are only initialized and used if the variable
> "conn_from_host" is true. The code is not buggy here.
> 
> Signed-off-by: Dexuan Cui <decui@microsoft.com>

Applied.