kernel/linux.git/tools/testing/selftests/net/lib/py/utils.py, branch v7.2-rc1

selftests: drv-net: add userns devmem RX test

2026-06-06T01:10:31+00:00

Add userns_devmem.py, which mirrors nk_devmem.py but places the netkit guest in a netns whose owning user_ns is non-init. ncdevmem is ran there via nsenter so the bind-rx call is issued with creds that hold CAP_NET_ADMIN only in the child user_ns. Without the preceding GENL_UNS_ADMIN_PERM patch the test fails at bind-rx with EPERM, but with the patch the transfer completes and tests pass. Signed-off-by: Bobby Eshleman Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20260602-nl-prov-v2-2-ad721142c641@meta.com Signed-off-by: Jakub Kicinski

selftests: net: py: add tc utility

2026-05-06T01:15:29+00:00

Add a wrapper similar to existing ip, ethtool, ... commands. Tc takes a slightly different syntax. Account for that. The first user is the next patch in this series, converting so_txtime to drv-net. Pacing offload is supported by selected qdiscs only. Signed-off-by: Willem de Bruijn Link: https://patch.msgid.link/20260504174056.565319-3-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski

selftests: net: py: support cmd verifying expected failure

2026-05-06T01:15:29+00:00

Support negative tests, where cmd raises an exception if the command succeeded. Add optional argument expect_fail to cmd and bkg. Where fail fails the test on unexpected error, expect_fail fails it on unexpected success. Both fail on negative return code. Python subprocess may set a negative return code on process crash or timeout. Those are never anticipated failures. Signed-off-by: Willem de Bruijn Link: https://patch.msgid.link/20260504174056.565319-2-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski

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