kernel/linux.git/tools/testing/selftests/net/lib/py/utils.py, branch v7.1-rc5

selftests: net: py: give bpftrace more time to start

2026-03-17T02:26:37+00:00

After commit under Fixes debug runners in the CI hit the following: # subprocess.TimeoutExpired: Command '['bpftrace', '-f', 'json', '-q', '-e', 'kprobe:netpoll_poll_dev { @hits = count(); } interval:s:10 { exit(); }']' timed out after 15 seconds # # Exception| net.lib.py.ksft.KsftFailEx: bpftrace failed to run!?: {} in netpoll_basic.py >10% of the time. Let's give bpftool more time to start, it can take a while on a debug kernel. Fixes: 82562972b854 ("selftests: net: pass bpftrace timeout to cmd()") Reviewed-by: Breno Leitao Reviewed-by: Petr Machata Reviewed-by: Nimrod Oren Link: https://patch.msgid.link/20260315160038.3187730-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

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

2026-03-12T02:11:40+00:00

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. Reviewed-by: Nimrod Oren Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20260310115803.2521050-3-gal@nvidia.com Signed-off-by: Jakub Kicinski

selftests: net: pass bpftrace timeout to cmd()

2026-03-12T02:11:36+00:00

The bpftrace() helper configures an interval based exit timer but does not propagate the timeout to the cmd object, which defaults to 5 seconds. Since the default BPFTRACE_TIMEOUT is 10 seconds, cmd.process() always raises a TimeoutExpired exception before bpftrace has a chance to exit gracefully. Pass timeout+5 to cmd() to allow bpftrace to complete gracefully. Note: this issue is masked by a bug in the way cmd() passes timeout, this is fixed in the next commit. Reviewed-by: Nimrod Oren Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20260310115803.2521050-2-gal@nvidia.com Signed-off-by: Jakub Kicinski

selftests: net: py: Add rand_ports helper method

2026-02-26T03:42:02+00:00

Certain tests need a unique set of ports. Successive calls to the existing rand_port method may return a duplicate port, resulting in test flakiness. The new helper keeps sockets open while building a list of ephemeral ports, thus the kernel enforces their uniqueness. Signed-off-by: Dimitri Daskalakis Link: https://patch.msgid.link/20260224224659.1507082-2-dimitri.daskalakis1@gmail.com Signed-off-by: Jakub Kicinski

selftests: net: py: add cmd info for ksft_wait failure

2026-02-25T02:25:29+00:00

Gal recently complained: When [ksft_wait failure] happens, the test fails with a cryptic message: # Exception| Exception: Did not receive ready message Let's try to include the stdout/stderr of the command we tried to start. E.g. for cmd("false", ksft_wait=True): # Exception| lib.py.utils.CmdInitFailure: Did not receive ready message # Exception| CMD: false # Exception| EXIT: 1 We need to factor out _process_terminate() otherwise the exit path may try to write to already disconnected self.ksft_term_fd. Reviewed-by: Petr Machata Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260223202633.4126087-4-kuba@kernel.org Signed-off-by: Jakub Kicinski

selftests: net: py: use repr(cmd) for failure exceptions

2026-02-25T02:25:29+00:00

Reuse repr(cmd) instead of manually formatting a similar string. Before: # Exception| lib.py.utils.CmdExitFailure: Command failed: false # Exception| STDOUT: b'' # Exception| STDERR: b'' After: # Exception| lib.py.utils.CmdExitFailure: Command failed # Exception| CMD: false # Exception| EXIT: 1 Reviewed-by: Petr Machata Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260223202633.4126087-3-kuba@kernel.org Signed-off-by: Jakub Kicinski

selftests: net: py: avoid masking exceptions in bkg() failures

2026-02-25T02:25:29+00:00

bkg() failures are currently quite hard to debug and spot. Often we have code along the lines of: with bkg("./cmd_rx_something -p PORT"): wait_port_listen(PORT) cmd("./cmd_tx_something", host=remote) When wait_port_listen() fails we don't get to see the exit status of bkg(). Even tho very often it's a failure in the bkg() command that's actually to blame. Try not to interfere with the bkg() command error checking. With: with bkg("false", exit_wait=True): time.sleep(0.01) # let the 'false' cmd run raise Exception("bla") Before: .. stack trace .. # Exception| Exception: bla After: .. stack trace .. # Exception| Exception: bla # Exception| # Exception| During handling of the above exception, another exception occurred: .. stack trace .. # Exception| lib.py.utils.CmdExitFailure: Command failed: false # Exception| STDOUT: b'' # Exception| STDERR: b'' Reviewed-by: Petr Machata Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260223202633.4126087-2-kuba@kernel.org Signed-off-by: Jakub Kicinski

selftests: net: fix wrong boolean evaluation in exit

2026-01-27T03:32:20+00:00

The __exit__ method receives ex_type as the exception class when an exception occurs. The previous code used implicit boolean evaluation: terminate = self.terminate or (self._exit_wait and ex_type) ^^^^^^^^^^^ In Python, the and operator can be used with non-boolean values, but it does not always return a boolean result. This is probably not what we want, because 'self._exit_wait and ex_type' could return the actual ex_type value (the exception class) rather than a boolean True when an exception occurs. Use explicit `ex_type is not None` check to properly evaluate whether an exception occurred, returning a boolean result. Reviewed-by: Nimrod Oren Signed-off-by: Gal Pressman Link: https://patch.msgid.link/20260125105524.773993-1-gal@nvidia.com Signed-off-by: Jakub Kicinski

selftests: net: py: teach cmd() how to print itself

2026-01-14T01:54:00+00:00

Teach cmd() how to print itself, to make debug prints easier. Example output (leading # due to ksft_pr()): # CMD: /root/ksft-net-drv/drivers/net/gro # EXIT: 1 # STDOUT: ipv6 with ext header does coalesce: # STDERR: Expected {200 }, Total 1 packets # Received {100 [!=200]100 [!=0]}, Total 2 packets. Reviewed-by: Petr Machata Link: https://patch.msgid.link/20260113000740.255360-3-kuba@kernel.org Signed-off-by: Jakub Kicinski

selftests: net: py: ensure defer() is only used within a test case

2026-01-10T23:11:59+00:00

I wasted a couple of hours recently after accidentally adding a defer() from within a function which itself was called as part of defer(). This leads to an infinite loop of defer(). Make sure this cannot happen and raise a helpful exception. I understand that the pair of _ksft_defer_arm() calls may not be the most Pythonic way to implement this, but it's easy enough to understand. Reviewed-by: Petr Machata Link: https://patch.msgid.link/20260108225257.2684238-2-kuba@kernel.org Signed-off-by: Jakub Kicinski

kernel/linux.git/tools/testing/selftests/net/lib/py/utils.py, branch v7.1-rc5

selftests: net: py: give bpftrace more time to start

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

selftests: net: pass bpftrace timeout to cmd()

selftests: net: py: Add rand_ports helper method

selftests: net: py: add cmd info for ksft_wait failure

selftests: net: py: use repr(cmd) for failure exceptions

selftests: net: py: avoid masking exceptions in bkg() failures

selftests: net: fix wrong boolean evaluation in __exit__

selftests: net: py: teach cmd() how to print itself

selftests: net: py: ensure defer() is only used within a test case

selftests: net: fix wrong boolean evaluation in exit