On Thu, Aug 12, 2021 at 02:06:02PM -0500, madvenka@linux.microsoft.com wrote: > + if (frame->need_reliable && !unwind_is_reliable(frame)) { > + /* Cannot unwind to the next frame reliably. */ > + frame->failed = true; > + return false; > + } This means we only collect reliability information in the case where we're specifically doing a reliable stacktrace. For example when printing stack traces on the console it might be useful to print a ? or something if the frame is unreliable as a hint to the reader that the information might be misleading. Could we therefore change the flag here to a reliability one and our need_reliable check so that we always run unwind_is_reliable()? I'm not sure if we need to abandon the trace on first error when doing a reliable trace but I can see it's a bit safer so perhaps better to do so. If we don't abandon then we don't require the need_reliable check at all.