Messages in this thread | | | Date | Mon, 18 Jan 2021 17:50:54 +0000 | From | Mark Rutland <> | Subject | Re: [PATCH v4] Documentation: livepatch: document reliable stacktrace |
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Hi Petr,
On Mon, Jan 18, 2021 at 03:02:31PM +0100, Petr Mladek wrote: > On Fri 2021-01-15 17:16:17, Mark Brown wrote: > > I've made a few assumptions about preferred behaviour, notably: > > > > * If you can reliably unwind through exceptions, you should (as x86_64 > > does).
IIRC this was confirmed as desireable, and the text already reflects this.
> > * It's fine to omit ftrace_return_to_handler and other return > > trampolines so long as these are not subject to patching and the > > original return address is reported. Most architectures do this for > > ftrace_return_handler, but not other return trampolines.
Likewise I think we agreed this was fine, given these were not themselves subkect to patching.
> > * For cases where link register unreliability could result in duplicate > > entries in the trace or an inverted trace, I've assumed this should be > > treated as unreliable. This specific case shouldn't matter to > > livepatching, but I assume that that we want a reliable trace to have > > the correct order.
I don't think we had any comments either way on this, but I think it's sane to say this for now and later relax it if we need to.
... so I reckon we can just delete all this as Josh suggests. Any acks for the patch itself tacitly agrees with these points. :)
Thanks, Mark.
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