Stepping off breakpoints in non-stop debugging mode

[Daniel Jacobowitz]

On Tue, Dec 11, 2007 at 10:24:44AM -0800, Jim Blandy wrote:
> As far as PTRACE_SINGLESTEP is concerned, isn't pushfl the only
> user instruction that can observe the state of TF anyway?

I can't answer that.  Maybe Paul could.  The focus of the kernel code
I was referring to is instructions which modify the state of TF;
you can observe changes by telling whether you get a trap, if
your debugger's signal handling is good enough.  The debugger can do
a software single step over the pushfl instruction if it cares about
accuracy enough to bother, and/or fix up the resulting stack value.

-- 
Daniel Jacobowitz
CodeSourcery