In a few MPTCP selftest tools, gcc 12 complains that the 'sock' variable
might be used uninitialized. This is a false positive because the only
code path that could lead to uninitialized access is where getaddrinfo()
fails, but the local xgetaddrinfo() wrapper exits if such a failure
occurs.

Initialize the 'sock' variable anyway to allow the tools to build with
gcc 12.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
---
 tools/testing/selftests/net/mptcp/mptcp_connect.c | 2 +-
 tools/testing/selftests/net/mptcp/mptcp_inq.c     | 2 +-
 tools/testing/selftests/net/mptcp/mptcp_sockopt.c | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c b/tools/testing/selftests/net/mptcp/mptcp_connect.c
index 8628aa61b763..e2ea6c126c99 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_connect.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c
@@ -265,7 +265,7 @@ static void sock_test_tcpulp(int sock, int proto, unsigned int line)
 static int sock_listen_mptcp(const char * const listenaddr,
 			     const char * const port)
 {
-	int sock;
+	int sock = -1;
 	struct addrinfo hints = {
 		.ai_protocol = IPPROTO_TCP,
 		.ai_socktype = SOCK_STREAM,
diff --git a/tools/testing/selftests/net/mptcp/mptcp_inq.c b/tools/testing/selftests/net/mptcp/mptcp_inq.c
index 29f75e2a1116..8672d898f8cd 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_inq.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_inq.c
@@ -88,7 +88,7 @@ static void xgetaddrinfo(const char *node, const char *service,
 static int sock_listen_mptcp(const char * const listenaddr,
 			     const char * const port)
 {
-	int sock;
+	int sock = -1;
 	struct addrinfo hints = {
 		.ai_protocol = IPPROTO_TCP,
 		.ai_socktype = SOCK_STREAM,
diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
index ac9a4d9c1764..ae61f39556ca 100644
--- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
+++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
@@ -136,7 +136,7 @@ static void xgetaddrinfo(const char *node, const char *service,
 static int sock_listen_mptcp(const char * const listenaddr,
 			     const char * const port)
 {
-	int sock;
+	int sock = -1;
 	struct addrinfo hints = {
 		.ai_protocol = IPPROTO_TCP,
 		.ai_socktype = SOCK_STREAM,
-- 
2.36.1

Hi Mat, Paolo,

On 22/06/2022 02:18, Mat Martineau wrote:
> In a few MPTCP selftest tools, gcc 12 complains that the 'sock' variable
> might be used uninitialized. This is a false positive because the only
> code path that could lead to uninitialized access is where getaddrinfo()
> fails, but the local xgetaddrinfo() wrapper exits if such a failure
> occurs.
> 
> Initialize the 'sock' variable anyway to allow the tools to build with
> gcc 12.

Thank you for the patch and the review!

I just applied this patch in our tree (feat. for net-next but maybe it
could go in 'fix for -net' with a 'Fixes' tag, no?) with Paolo's ACK:

New patches for t/upstream:
- 5a3689ec11a3: selftests: mptcp: Initialize variables to quiet gcc 12
warnings
- Results: 8346c4604d29..cbb1cc653035 (export)

Builds and tests are now in progress:

https://cirrus-ci.com/github/multipath-tcp/mptcp_net-next/export/20220622T211129
https://github.com/multipath-tcp/mptcp_net-next/actions/workflows/build-validation.yml?query=branch:export

Cheers,
Matt
-- 
Tessares | Belgium | Hybrid Access Solutions
www.tessares.net

On Tue, 2022-06-21 at 17:18 -0700, Mat Martineau wrote:
> In a few MPTCP selftest tools, gcc 12 complains that the 'sock' variable
> might be used uninitialized. This is a false positive because the only
> code path that could lead to uninitialized access is where getaddrinfo()
> fails, but the local xgetaddrinfo() wrapper exits if such a failure
> occurs.
> 
> Initialize the 'sock' variable anyway to allow the tools to build with
> gcc 12.
> 
> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
> ---
>  tools/testing/selftests/net/mptcp/mptcp_connect.c | 2 +-
>  tools/testing/selftests/net/mptcp/mptcp_inq.c     | 2 +-
>  tools/testing/selftests/net/mptcp/mptcp_sockopt.c | 2 +-
>  3 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/testing/selftests/net/mptcp/mptcp_connect.c b/tools/testing/selftests/net/mptcp/mptcp_connect.c
> index 8628aa61b763..e2ea6c126c99 100644
> --- a/tools/testing/selftests/net/mptcp/mptcp_connect.c
> +++ b/tools/testing/selftests/net/mptcp/mptcp_connect.c
> @@ -265,7 +265,7 @@ static void sock_test_tcpulp(int sock, int proto, unsigned int line)
>  static int sock_listen_mptcp(const char * const listenaddr,
>  			     const char * const port)
>  {
> -	int sock;
> +	int sock = -1;
>  	struct addrinfo hints = {
>  		.ai_protocol = IPPROTO_TCP,
>  		.ai_socktype = SOCK_STREAM,
> diff --git a/tools/testing/selftests/net/mptcp/mptcp_inq.c b/tools/testing/selftests/net/mptcp/mptcp_inq.c
> index 29f75e2a1116..8672d898f8cd 100644
> --- a/tools/testing/selftests/net/mptcp/mptcp_inq.c
> +++ b/tools/testing/selftests/net/mptcp/mptcp_inq.c
> @@ -88,7 +88,7 @@ static void xgetaddrinfo(const char *node, const char *service,
>  static int sock_listen_mptcp(const char * const listenaddr,
>  			     const char * const port)
>  {
> -	int sock;
> +	int sock = -1;
>  	struct addrinfo hints = {
>  		.ai_protocol = IPPROTO_TCP,
>  		.ai_socktype = SOCK_STREAM,
> diff --git a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
> index ac9a4d9c1764..ae61f39556ca 100644
> --- a/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
> +++ b/tools/testing/selftests/net/mptcp/mptcp_sockopt.c
> @@ -136,7 +136,7 @@ static void xgetaddrinfo(const char *node, const char *service,
>  static int sock_listen_mptcp(const char * const listenaddr,
>  			     const char * const port)
>  {
> -	int sock;
> +	int sock = -1;
>  	struct addrinfo hints = {
>  		.ai_protocol = IPPROTO_TCP,
>  		.ai_socktype = SOCK_STREAM,

LGTM, thanks!

Acked-by: Paolo Abeni <pabeni@redhat.com>

Hi Mat,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal:
  - Success! ✅:
  - Task: https://cirrus-ci.com/task/6252603284652032
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/6252603284652032/summary/summary.txt

- KVM Validation: debug:
  - Unstable: 2 failed test(s): selftest_diag selftest_mptcp_join 🔴:
  - Task: https://cirrus-ci.com/task/4845228401098752
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/4845228401098752/summary/summary.txt

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/623b51ae3220


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-debug

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (Tessares)