[PATCH net] selftests: net: fix timeout passed as positional argument to communicate()

[PATCH net] selftests: net: fix timeout passed as positional argument to communicate()

[Gal Pressman]

The cited commit refactored the hardcoded timeout=5 into a parameter,
but dropped the keyword from the communicate() call.
Since Popen.communicate()'s first positional argument is 'input' (not
'timeout'), the timeout value is silently treated as stdin input and the
call never enforces a timeout.

Pass timeout as a keyword argument to restore the intended behavior.

Fixes: 1cf270424218 ("net: selftest: add test for netdev netlink queue-get API")
Reviewed-by: Nimrod Oren <noren@nvidia.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
---
 tools/testing/selftests/net/lib/py/utils.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/net/lib/py/utils.py b/tools/testing/selftests/net/lib/py/utils.py
index 106ee1f2df86..73b1b0460436 100644
--- a/tools/testing/selftests/net/lib/py/utils.py
+++ b/tools/testing/selftests/net/lib/py/utils.py
@@ -86,7 +86,7 @@ class cmd:
             os.write(self.ksft_term_fd, b"1")
         if terminate:
             self.proc.terminate()
-        stdout, stderr = self.proc.communicate(timeout)
+        stdout, stderr = self.proc.communicate(timeout=timeout)
         self.stdout = stdout.decode("utf-8")
         self.stderr = stderr.decode("utf-8")
         self.proc.stdout.close()
-- 
2.52.0

Re: [PATCH net] selftests: net: fix timeout passed as positional argument to communicate()

[Jakub Kicinski]

On Sun, 15 Feb 2026 14:51:49 +0200 Gal Pressman wrote:
> The cited commit refactored the hardcoded timeout=5 into a parameter,
> but dropped the keyword from the communicate() call.
> Since Popen.communicate()'s first positional argument is 'input' (not
> 'timeout'), the timeout value is silently treated as stdin input and the
> call never enforces a timeout.
> 
> Pass timeout as a keyword argument to restore the intended behavior.

Makes sense, but looks like
tools/testing/selftests/drivers/net/netpoll_basic.py
fails now:

https://netdev-ctrl.bots.linux.dev/logs/vmksft/net-drv/results/519460/3-netpoll-basic-py/stdout

I think bpftrace() needs to pass the timeout to cmd().
Probably something like the timeout param that it's passed + 5 sec?
-- 
pw-bot: cr