[PATCH, v2] Expect SI_KERNEL or TRAP_BRKPT si_code values for MIPS breakpoint traps

[Maciej W. Rozycki]

On Mon, 22 Feb 2016, Pedro Alves wrote:

> I'd like to have a short paragraph in linux-nat.h about MIPS's behavior,
> below the ppc comment.  If you look at the x86 table above, which cases get
> SI_KERNEL, and which don't?  Single-step is not applicable, since the
> MIPS doesn't handle single-stepping itself (IIRC), but do we also get
> SI_KERNEL hardware bps and watchpoints, for example?

 As I previously noted the MIPS Linux port currently does not support 
hardware breakpoints even though hardware may have them implemented 
(they're optional).  Only hardware watchpoints are supported right now.

 You are right in that there's no OS single-stepping support defined in 
the MIPS architecture and consequently Linux cannot support it on the MIPS 
target.  Only JTAG single-stepping is possible with MIPS hardware.

  Maciej