Madhavan Srinivasan <ma...@linux.vnet.ibm.com> writes: > On Monday 15 October 2018 04:38 PM, Michael Ellerman wrote: >> Madhavan Srinivasan <ma...@linux.vnet.ibm.com> writes: >> >>> On Saturday 13 October 2018 04:26 PM, Michael Ellerman wrote: ... >>>> At the moment they're still identical, and we check that at build >>>> time. That's because we have code (in ptrace etc.) that assumes that >>>> they are the same. We will fix that code in future patches, and then >>>> we can break the strict symmetry between the two structs. >>> Nice and awesome. But just trying to understand. What will >>> *regs will point to in the "struct sigcontext". >> >> It should always point to a user_pt_regs. ... >> >> I think it's not actually broken at the moment, because it's just a >> pointer, and we don't do anything based on the sizeof() the type. > > yes. This clarifies. But still perf/perf_regs.c needs changes. > Because perf support dumping user_space regs and interrupt regs. > Once again, we dont use any sizeof(), but need to handle the > user_pt_regs changes. > > I will have a look at that in the morning.
I did look at that and convinced myself that it was OK, but maybe I'm wrong :D My reasoning was that the regs we're using there are always the in-kernel regs for the process at the point it took the PMU interrupt. And the regs values aren't exported directly as a struct but rather via regs_get_register(). But we may still want to change it to make things clearer. cheers
