On Mon, Mar 09, 2020 at 09:05:05PM +0000, Mark Brown wrote:

On Fri, Mar 06, 2020 at 10:27:29AM +0000, Catalin Marinas wrote:

quoted

Does this series affect uprobes in any way? I.e. can you probe a landing
pad?

You can't probe a landing pad, uprobes on landing pads will be silently
ignored so the program isn't disrupted, you just don't get the expected
trace from those uprobes.  This isn't new with the BTI support since
the landing pads are generally pointer auth instructions, these already
can't be probed regardless of what's going on with this series.  It's
already on the list to get sorted.

Sorry, I realized thanks to Amit's off-list prompting that I was testing
that I was verifying with the wrong kernel binary here (user error since
it took me a while to sort out uprobes) so this isn't quite right - you
can probe the landing pads with or without this series.