* Frédéric Weisbecker <fweisbec@xxxxxxxxx> wrote: > > All the above functionality is almost what we need. The only thing > > left, which I forgot to mention, is possibility to log also functions > > return value on exit. This is what TRACE_EXIT_RES() in SCST does. Is > > it possible to add those? > > I want to add that on the function graph tracer. That can be done pretty > easily. The only problem comes with the type of the return value. Would > this tracer be supposed to always return a 64 bits value regardless of > the real typ of the value? There would be some pointless bytes on most > return values. I don't know how to proceed for this problem. Things like mov ...,%eax are zero-extend so they'll zap the high 32 bits. The real problem are byte return values generated via things like: movb $1, %al those wont zero-extend, so you could get garbage in the output. One approach would be to try a quick hack just to see how common a problem this is. We could extract the return type from the debuginfo, hash it in a read-mostly table and then look it up, but that seems complex both in terms of build overhead and in terms of runtime overhead. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
