> >>         assert(ctx->uc_mcontext.gregs[REG_EFL] ==
> >>                ctx->uc_mcontext.gregs[REG_R11]);
> > On FRED systems, flags is 0x200a93 and r11 is 0xfeedfacedeadbeef here.
> 
> Is this under SIMICS, or elsewhere?  It's doubly weird that flags/%r11 match, but
> %rip/%rcx don't.

This is on Intel Simics, with FRED enabled.

Flags and %r11 don’t match on FRED, and %rip and %rcx also don't match.

I think it's expected.

Xin