Re: Register fudging (CRISv32)

[Orjan Friberg <orjan.friberg@axis.com>]

Daniel Jacobowitz wrote:
> 

Daniel, thanks for you answers.

> Up to you.  I think doing it in the kernel stub and kernel ptrace
> support is a better strategy, esp. if you have additional information
> confirming that a breakpoint was hit.

In the kernel I know for sure it was a breakpoint (or, more 
specifically, a certain break instruction was executed, which is how 
ordinary breakpoints are implemented).

> There's arguments both ways for this.  For instance, I think it would
> be reasonable to do this in the kernel.

Except for the fact that the "PC" doesn't exist in the kernel - it's a 
made up register, which is set either from the exception return pointer 
register (+ possibly delay slot adjustment), or from the single-step PC 
(when we're single-stepping that is).  Or are you suggesting that the 
pseudo-PC *should be* in the kernel (if not part of the pt_regs struct, 
then at least accessible by ptrace)?

> Not sure what you mean by this.

For example, in case of a PTRACE_CONT I set the single-step PC to 0 to 
disable single-stepping (similar to what the m68k does).

-- 
Orjan Friberg
Axis Communications