From 6668ed271eaefaa63e686bdfbedaeb7b8e492722 Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Fri, 4 Sep 2026 10:43:19 +0200 Subject: selftests/bpf: Reject graph kptr use after RCU unlock 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 Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- Documentation/tools/unittest.rst | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 Documentation/tools/unittest.rst (limited to 'Documentation/tools/unittest.rst') diff --git a/Documentation/tools/unittest.rst b/Documentation/tools/unittest.rst new file mode 100644 index 000000000..0fa871674 --- /dev/null +++ b/Documentation/tools/unittest.rst @@ -0,0 +1,24 @@ +.. 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: -- cgit v1.3.1