Hi,

We use breakpoints on CRIU to stop a processes before calling
rt_sigreturn and we found that sometimes a process runs through a
break-point without stopping on it.

https://github.com/xemul/criu/issues/162


A small reproducer is attached. It forks a child, stops it, sets a
breakpoint, executes a child, waits when it stops on the breakpoint. I
execute it a few times concurrently and wait a few minutes.

https://asciinema.org/a/006l3u5v82ubbkfy9fto07agd

I know that it can be reproduced on:
AMD A10 Micro-6700T
Intel(R) Core(TM) i5-5200U CPU @ 2.20GHz
Intel(R) Core(TM) i7-4600U CPU @ 2.10GHz

so It doesn't look like a bug in a processor.

Thanks,
Andrew