[PATCH mptcp-next] mptcp: return 0 instead of 'err' var

[PATCH mptcp-next] mptcp: return 0 instead of 'err' var

[Matthieu Baerts]

When 'err' is 0, it looks clearer to return '0' instead of the variable
called 'err'.

The behaviour is then not modified, just a clearer code.

By doing this, we can also avoid false positive smatch warnings like
this one:

  net/mptcp/pm_netlink.c:1169 mptcp_pm_parse_pm_addr_attr() warn: missing error code? 'err'

Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
---
 net/mptcp/pm_netlink.c | 4 ++--
 net/mptcp/sockopt.c    | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 39b0f054f39f..d20f1d969900 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1187,7 +1187,7 @@ static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
 
 	if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
 		if (!require_family)
-			return err;
+			return 0;
 
 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
 				    "missing family");
@@ -1221,7 +1221,7 @@ static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
 	if (tb[MPTCP_PM_ADDR_ATTR_PORT])
 		addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
 
-	return err;
+	return 0;
 }
 
 int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index a47423ebb33a..d4b1e6ec1b36 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -740,7 +740,7 @@ static int mptcp_setsockopt_v4_set_tos(struct mptcp_sock *msk, int optname,
 	}
 	release_sock(sk);
 
-	return err;
+	return 0;
 }
 
 static int mptcp_setsockopt_v4(struct mptcp_sock *msk, int optname,

base-commit: 9324c815f96dd77d23679e999edb875d9f4acd34
-- 
2.37.2

Re: mptcp: return 0 instead of 'err' var: Tests Results

[MPTCP CI]

Hi Matthieu,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join):
  - Success! ✅:
  - Task: https://cirrus-ci.com/task/6075817906667520
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/6075817906667520/summary/summary.txt

- KVM Validation: normal (only selftest_mptcp_join):
  - Success! ✅:
  - Task: https://cirrus-ci.com/task/5512867953246208
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/5512867953246208/summary/summary.txt

- KVM Validation: debug (only selftest_mptcp_join):
  - Success! ✅:
  - Task: https://cirrus-ci.com/task/4598074278936576
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/4598074278936576/summary/summary.txt

- KVM Validation: debug (except selftest_mptcp_join):
  - Critical: 1 Call Trace(s) ❌:
  - Task: https://cirrus-ci.com/task/6638767860088832
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/6638767860088832/summary/summary.txt

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/9fbf63562082


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)

Re: [PATCH mptcp-next] mptcp: return 0 instead of 'err' var

[Mat Martineau]

On Mon, 5 Dec 2022, Matthieu Baerts wrote:

> When 'err' is 0, it looks clearer to return '0' instead of the variable
> called 'err'.
>
> The behaviour is then not modified, just a clearer code.
>
> By doing this, we can also avoid false positive smatch warnings like
> this one:
>
>  net/mptcp/pm_netlink.c:1169 mptcp_pm_parse_pm_addr_attr() warn: missing error code? 'err'
>
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <error27@gmail.com>
> Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>

Thanks for the cleanup Matthieu. Looks good to me.

Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>


> ---
> net/mptcp/pm_netlink.c | 4 ++--
> net/mptcp/sockopt.c    | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
> index 39b0f054f39f..d20f1d969900 100644
> --- a/net/mptcp/pm_netlink.c
> +++ b/net/mptcp/pm_netlink.c
> @@ -1187,7 +1187,7 @@ static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
>
> 	if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
> 		if (!require_family)
> -			return err;
> +			return 0;
>
> 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
> 				    "missing family");
> @@ -1221,7 +1221,7 @@ static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
> 	if (tb[MPTCP_PM_ADDR_ATTR_PORT])
> 		addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
>
> -	return err;
> +	return 0;
> }
>
> int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
> diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
> index a47423ebb33a..d4b1e6ec1b36 100644
> --- a/net/mptcp/sockopt.c
> +++ b/net/mptcp/sockopt.c
> @@ -740,7 +740,7 @@ static int mptcp_setsockopt_v4_set_tos(struct mptcp_sock *msk, int optname,
> 	}
> 	release_sock(sk);
>
> -	return err;
> +	return 0;
> }
>
> static int mptcp_setsockopt_v4(struct mptcp_sock *msk, int optname,
>
> base-commit: 9324c815f96dd77d23679e999edb875d9f4acd34
> -- 
> 2.37.2
>
>

--
Mat Martineau
Intel

Re: [PATCH mptcp-next] mptcp: return 0 instead of 'err' var

[Matthieu Baerts]

Hi Mat,

On 05/12/2022 22:31, Mat Martineau wrote:
> On Mon, 5 Dec 2022, Matthieu Baerts wrote:
> 
>> When 'err' is 0, it looks clearer to return '0' instead of the variable
>> called 'err'.
>>
>> The behaviour is then not modified, just a clearer code.
>>
>> By doing this, we can also avoid false positive smatch warnings like
>> this one:
>>
>>  net/mptcp/pm_netlink.c:1169 mptcp_pm_parse_pm_addr_attr() warn:
>> missing error code? 'err'
>>
>> Reported-by: kernel test robot <lkp@intel.com>
>> Reported-by: Dan Carpenter <error27@gmail.com>
>> Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
>> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
> 
> Thanks for the cleanup Matthieu. Looks good to me.
> 
> Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>

Thank you for the review!

Now in our tree (feat. for net-next) with your RvB tag:

New patches for t/upstream:
- 1172127291d8: mptcp: return 0 instead of 'err' var
- Results: c7fdd02a4241..fb04e49223d2 (export)

Tests are now in progress:

https://cirrus-ci.com/github/multipath-tcp/mptcp_net-next/export/20221206T110210

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

Re: mptcp: return 0 instead of 'err' var: Tests Results

[MPTCP CI]

Hi Matthieu,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join):
  - Success! ✅:
  - Task: https://cirrus-ci.com/task/6314116181131264
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/6314116181131264/summary/summary.txt

- KVM Validation: debug (only selftest_mptcp_join):
  - Unstable: 1 failed test(s): selftest_mptcp_join 🔴:
  - Task: https://cirrus-ci.com/task/5469691250999296
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/5469691250999296/summary/summary.txt

- KVM Validation: debug (except selftest_mptcp_join):
  - Success! ✅:
  - Task: https://cirrus-ci.com/task/6032641204420608
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/6032641204420608/summary/summary.txt

- KVM Validation: normal (only selftest_mptcp_join):
  - Success! ✅:
  - Task: https://cirrus-ci.com/task/4906741297577984
  - Summary: https://api.cirrus-ci.com/v1/artifact/task/4906741297577984/summary/summary.txt

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/03d981012d68


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)