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authorKumar Kartikeya Dwivedi <memxor@gmail.com>2026-09-04 10:43:19 +0200
committerAlexei Starovoitov <ast@kernel.org>2026-09-04 07:58:36 -0700
commit6668ed271eaefaa63e686bdfbedaeb7b8e492722 (patch)
tree58e8288fead484f6755ad0815fc74c3742663761 /Documentation/tools/unittest.rst
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selftests/bpf: Reject graph kptr use after RCU unlockgrafted
Add a sleepable verifier test that loads a graph-node local kptr in an explicit RCU read-side critical section, then passes its node to bpf_rbtree_remove() after the section ends. Before the verifier fix, the stale NON_OWN_REF flag makes the node look like a live borrowed reference and the program is accepted. After the fix, the pointer is demoted without NON_OWN_REF and the graph kfunc argument is rejected. Also exercise a graph kptr loaded while a spin lock provides implicit RCU protection. The pointer must be invalidated when the lock is released, which guards the required ordering between non-owning-reference invalidation and RCU demotion. Update the existing fault-protected load test state description. The post-unlock pointer no longer carries NON_OWN_REF, but remains readable because the load is rewritten to use BPF_PROBE_MEM. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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+.. SPDX-License-Identifier: GPL-2.0
+
+===============
+Python unittest
+===============
+
+Checking consistency of python modules can be complex. Sometimes, it is
+useful to define a set of unit tests to help checking them.
+
+While the actual test implementation is usecase dependent, Python already
+provides a standard way to add unit tests by using ``import unittest``.
+
+Using such class, requires setting up a test suite. Also, the default format
+is a little bit awkward. To improve it and provide a more uniform way to
+report errors, some unittest classes and functions are defined.
+
+
+Unittest helper module
+======================
+
+.. automodule:: lib.python.unittest_helper
+ :members:
+ :show-inheritance:
+ :undoc-members: