== Justification ==
When running the ftrace in ubunut_kernel_selftests, the "Kprobe event string type argument" test will fail on Bionic / Cosmic i386:
[22] Kprobe event string type argument [FAIL]
This is because the test was trying to probe a notrace function.
# grep create_trace_kprobe /sys/kernel/debug/tracing/available_filter_functions
== Fix ==
6fc7c411 (selftests/ftrace: Fix kprobe string testcase to not probe notrace function)
This will change the event to trace in the test, from
create_trace_kprobe to tracefs_create_dir
Patch can be cherry-picked for Cosmic.
For Bionic and Xenial, it can be cherry-picked after the commit 9855c462 for bug 1812809.
Although we don't run this ftrace test in Xenial, it will still be a plus to fix this.
It's already been applied in D.
This patch belongs to a patchset [1], in which further limits kprobe-events probing on notrace function. To address this issue for the testing tool this one will be suffice.
[1] https://lkml.org/lkml/2018/7/30/257
== Test ==
Patch tested with Bionic / Cosmic i386. Test passed as expected:
[22] Kprobe event string type argument [PASS]
== Regression potential ==
None.
This patch is just for the kernel testing tool.
== Original bug report ==
Failure spotted on Bionic / Cosmic i386 (node fozzie)
[22] Kprobe event string type argument [FAIL]
selftests: ftrace: ftracetest
========================================
=== Ftrace unit tests ===
[1] Basic trace file check [PASS]
[2] Basic test for tracers [PASS]
[3] Basic trace clock test [PASS]
[4] Basic event tracing check [PASS]
[5] Snapshot and tracing setting [PASS]
[6] event tracing - enable/disable with event level files [PASS]
[7] event tracing - restricts events based on pid [PASS]
[8] event tracing - enable/disable with subsystem level files [PASS]
[9] event tracing - enable/disable with top level files [PASS]
[10] ftrace - function graph filters with stack tracer [PASS]
[11] ftrace - function graph filters [PASS]
[12] ftrace - function pid filters [PASS]
[13] ftrace - test for function event triggers [PASS]
[14] ftrace - function profiler with function tracing [PASS]
[15] ftrace - test reading of set_ftrace_filter [PASS]
[16] ftrace - test for function traceon/off triggers [PASS]
[17] Test creation and deletion of trace instances while setting an event [PASS]
[18] Test creation and deletion of trace instances [PASS]
[19] Kprobe dynamic event - adding and removing [PASS]
[20] Kprobe dynamic event - busy event check [PASS]
[21] Kprobe dynamic event with arguments [PASS]
[22] Kprobe event string type argument [FAIL]
[23] Kprobe event argument syntax [PASS]
[24] Kprobes event arguments with types [PASS]
[25] Kprobe event auto/manual naming [PASS]
[26] Kprobe dynamic event with function tracer [PASS]
[27] Kretprobe dynamic event with arguments [PASS]
[28] Kretprobe dynamic event with maxactive [PASS]
[29] Register/unregister many kprobe events [PASS]
[30] event trigger - test extended error support [PASS]
[31] event trigger - test field variable support [PASS]
[32] event trigger - test multiple actions on hist trigger [PASS]
[33] event trigger - test inter-event histogram trigger onmatch action [PASS]
[34] event trigger - test inter-event histogram trigger onmatch-onmax action [PASS]
[35] event trigger - test inter-event histogram trigger onmax action [PASS]
[36] event trigger - test synthetic_events syntax parser [PASS]
[37] event trigger - test event enable/disable trigger [PASS]
[38] event trigger - test trigger filter [PASS]
[39] event trigger - test histogram modifiers [PASS]
[40] event trigger - test multiple histogram triggers [PASS]
[41] event trigger - test snapshot-trigger [PASS]
[42] event trigger - test stacktrace-trigger [PASS]
[43] trace_marker trigger - test snapshot trigger [PASS]
[44] trace_marker trigger - test histogram with synthetic event against kernel event [PASS]
[45] trace_marker trigger - test histogram with synthetic event [PASS]
[46] event trigger - test traceon/off trigger [PASS]
[47] (instance) Basic test for tracers [PASS]
[48] (instance) Basic trace clock test [PASS]
[49] (instance) Snapshot and tracing setting [PASS]
[50] (instance) event tracing - enable/disable with event level files [PASS]
[51] (instance) event tracing - restricts events based on pid [PASS]
[52] (instance) event tracing - enable/disable with subsystem level files [PASS]
[53] (instance) ftrace - test for function event triggers [PASS]
[54] (instance) ftrace - test for function traceon/off triggers [PASS]
[55] (instance) event trigger - test event enable/disable trigger [PASS]
[56] (instance) event trigger - test trigger filter [PASS]
[57] (instance) event trigger - test histogram modifiers [PASS]
[58] (instance) event trigger - test multiple histogram triggers [PASS]
[59] (instance) trace_marker trigger - test snapshot trigger [PASS]
# of passed: 58
# of failed: 1
# of unresolved: 0
# of untested: 0
# of unsupported: 0
# of xfailed: 0
# of undefined(test bug): 0
not ok 1..1 selftests: ftrace: ftracetest [FAIL]
This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:
apport-collect 1825780
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.