Re: [PATCH v16 08/13] selftests: tracing: Add a basic testcase for wprobe

[Masami Hiramatsu (Google) <mhiramat@kernel.org>]

On Mon, 14 Sep 2026 14:30:11 +0000
sashiko-bot@kernel.org wrote:

> Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
> - [Medium] Unhandled error from `echo 1 > enable` causes false test failure under `set -e` when hardware watchpoints are unsupported.
> --
> 
> commit 70eb02867fbc0203498e0161a5c4b437b562d025
> Author: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> 
> selftests: tracing: Add a basic testcase for wprobe
> 
> Add 'add_remove_wprobe.tc' testcase for testing wprobe event that
> tests adding and removing operations of the wprobe event.
> 
> > diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_wprobe.tc b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_wprobe.tc
> > new file mode 100644
> > index 0000000000000..647c37d5e4c84
> > --- /dev/null
> > +++ b/tools/testing/selftests/ftrace/test.d/dynevent/add_remove_wprobe.tc
> 
> [ ... ]
> 
> > +if [ ! -d events/wprobes/my_wprobe ]; then
> > +    echo "Failed to create wprobe event directory"
> > +    exit_fail
> > +fi
> > +
> > +echo 1 > events/wprobes/my_wprobe/enable
> 
> [Severity: Medium]
> Will this script falsely report a failure if hardware watchpoints are
> exhausted or unsupported on the platform?
> 
> Writing to the enable file triggers enable_trace_wprobe() and eventually
> register_wide_hw_breakpoint(), which allocates physical hardware debug
> registers. If this allocation fails (e.g., returning -ENOSPC or -EOPNOTSUPP),
> the echo command will return a non-zero exit status.
> 
> Because ftracetest runs test scripts with 'set -e' (errexit) active, this
> error will abort the script immediately and fail the test instead of safely
> skipping it.
> 
> Should this write be guarded with something like "|| exit_unsupported" to
> handle expected hardware limitations?

Hmm, this is not unsupported, but unresolved (environmental test
failure case).

Thanks,


-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>