When building with clang, via:

    make LLVM=1 -C tools/testing/selftest

...clang warns about three variables that are not initialized in all
cases:

1) The opt_ipproto_off variable is used uninitialized if "testname" is
not "ip". Willem de Bruijn pointed out that this is an actual bug, and
suggested the fix that I'm using here (thanks!).

2) The addr_len is used uninitialized, but only in the assert case,
   which bails out, so this is harmless.

3) The family variable in add_listener() is only used uninitialized in
   the error case (neither IPv4 nor IPv6 is specified), so it's also
   harmless.

Fix by initializing each variable.

Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 tools/testing/selftests/net/gro.c                 | 3 +++
 tools/testing/selftests/net/ip_local_port_range.c | 2 +-
 tools/testing/selftests/net/mptcp/pm_nl_ctl.c     | 2 +-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/net/gro.c b/tools/testing/selftests/net/gro.c
index 353e1e867fbb..6038b96ecee8 100644
--- a/tools/testing/selftests/net/gro.c
+++ b/tools/testing/selftests/net/gro.c
@@ -119,6 +119,9 @@ static void setup_sock_filter(int fd)
 		next_off = offsetof(struct ipv6hdr, nexthdr);
 	ipproto_off = ETH_HLEN + next_off;
 
+	/* Overridden later if exthdrs are used: */
+	opt_ipproto_off = ipproto_off;
+
 	if (strcmp(testname, "ip") == 0) {
 		if (proto == PF_INET)
 			optlen = sizeof(struct ip_timestamp);
diff --git a/tools/testing/selftests/net/ip_local_port_range.c b/tools/testing/selftests/net/ip_local_port_range.c
index 193b82745fd8..29451d2244b7 100644
--- a/tools/testing/selftests/net/ip_local_port_range.c
+++ b/tools/testing/selftests/net/ip_local_port_range.c
@@ -359,7 +359,7 @@ TEST_F(ip_local_port_range, late_bind)
 		struct sockaddr_in v4;
 		struct sockaddr_in6 v6;
 	} addr;
-	socklen_t addr_len;
+	socklen_t addr_len = 0;
 	const int one = 1;
 	int fd, err;
 	__u32 range;
diff --git a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
index 7426a2cbd4a0..7ad5a59adff2 100644
--- a/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
+++ b/tools/testing/selftests/net/mptcp/pm_nl_ctl.c
@@ -1276,7 +1276,7 @@ int add_listener(int argc, char *argv[])
 	struct sockaddr_storage addr;
 	struct sockaddr_in6 *a6;
 	struct sockaddr_in *a4;
-	u_int16_t family;
+	u_int16_t family = AF_UNSPEC;
 	int enable = 1;
 	int sock;
 	int err;

base-commit: f462ae0edd3703edd6f22fe41d336369c38b884b
prerequisite-patch-id: b901ece2a5b78503e2fb5480f20e304d36a0ea27
prerequisite-patch-id: e81ae5ca6c427dde802acd4c1442c82e170c251a
-- 
2.45.0

On Mon, 6 May 2024, John Hubbard wrote:

> When building with clang, via:
>
>    make LLVM=1 -C tools/testing/selftest
>
> ...clang warns about three variables that are not initialized in all
> cases:
>
> 1) The opt_ipproto_off variable is used uninitialized if "testname" is
> not "ip". Willem de Bruijn pointed out that this is an actual bug, and
> suggested the fix that I'm using here (thanks!).
>
> 2) The addr_len is used uninitialized, but only in the assert case,
>   which bails out, so this is harmless.
>
> 3) The family variable in add_listener() is only used uninitialized in
>   the error case (neither IPv4 nor IPv6 is specified), so it's also
>   harmless.
>
> Fix by initializing each variable.
>
> Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>

Hi John -

MPTCP change looks good to me:

Acked-by: Mat Martineau <martineau@kernel.org>

Hi John,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal: Success! ✅
- KVM Validation: debug: Success! ✅
- KVM Validation: btf (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/8974532880

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/21cccbac5dd3
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=850921


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-normal

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 (NGI0 Core)

John Hubbard wrote:
> When building with clang, via:
> 
>     make LLVM=1 -C tools/testing/selftest
> 
> ...clang warns about three variables that are not initialized in all
> cases:
> 
> 1) The opt_ipproto_off variable is used uninitialized if "testname" is
> not "ip". Willem de Bruijn pointed out that this is an actual bug, and
> suggested the fix that I'm using here (thanks!).
> 
> 2) The addr_len is used uninitialized, but only in the assert case,
>    which bails out, so this is harmless.
> 
> 3) The family variable in add_listener() is only used uninitialized in
>    the error case (neither IPv4 nor IPv6 is specified), so it's also
>    harmless.
> 
> Fix by initializing each variable.
> 
> Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
> Signed-off-by: John Hubbard <jhubbard@nvidia.com>

Reviewed-by: Willem de Bruijn <willemb@google.com>

Thanks!