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| author | Joe Lawrence <joe.lawrence@redhat.com> | 2022-06-02 16:32:33 -0400 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2022-06-15 10:29:10 +0200 |
| commit | 55eb9a6c8bf3e2099863118ef53e02d9f44f85a8 (patch) | |
| tree | 64a40e61665e62d2fa4c2d5b648611e34d6dd6fd /tools/perf/util/parse-events.h | |
| parent | 7c9e960c636306f632ccae623bf94b2b53d35cbd (diff) | |
| download | linux-55eb9a6c8bf3e2099863118ef53e02d9f44f85a8.tar.bz2 | |
selftests/livepatch: better synchronize test_klp_callbacks_busy
The test_klp_callbacks_busy module conditionally blocks a future
livepatch transition by busy waiting inside its workqueue function,
busymod_work_func(). After scheduling this work, a test livepatch is
loaded, introducing the transition under test.
Both events are marked in the kernel log for later verification, but
there is no synchronization to ensure that busymod_work_func() logs its
function entry message before subsequent selftest commands log their own
messages. This can lead to a rare test failure due to unexpected
ordering like:
--- expected
+++ result
@@ -1,7 +1,7 @@
% modprobe test_klp_callbacks_busy block_transition=Y
test_klp_callbacks_busy: test_klp_callbacks_busy_init
-test_klp_callbacks_busy: busymod_work_func enter
% modprobe test_klp_callbacks_demo
+test_klp_callbacks_busy: busymod_work_func enter
livepatch: enabling patch 'test_klp_callbacks_demo'
livepatch: 'test_klp_callbacks_demo': initializing patching transition
test_klp_callbacks_demo: pre_patch_callback: vmlinux
Force the module init function to wait until busymod_work_func() has
started (and logged its message), before exiting to the next selftest
steps.
Fixes: 547840bd5ae5 ("selftests/livepatch: simplify test-klp-callbacks busy target tests")
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220602203233.979681-1-joe.lawrence@redhat.com
Diffstat (limited to 'tools/perf/util/parse-events.h')
0 files changed, 0 insertions, 0 deletions