Re: [Kgdb-bugreport] [KGDB][RFC] Send a fuller T packet

[Tom Rini <trini@kernel.crashing.org>]

On Tue, Mar 02, 2004 at 03:28:45PM -0800, George Anzinger wrote:

> Tom Rini wrote:
> >Hello.  Since a 'T' packet is allowed to send back information on an
> >arbitrary number of registers, and on PPC32 we've always been including
> >information on the stack pointer and program counter, I was wondering
> >what people thought of the following patch:
> >
> >diff -u linux-2.6.3/include/asm-x86_64/kgdb.h 
> >linux-2.6.3/include/asm-x86_64/kgdb.h
> >--- linux-2.6.3/include/asm-x86_64/kgdb.h	2004-02-27 
> >11:30:37.445782703 -0700
> >+++ linux-2.6.3/include/asm-x86_64/kgdb.h	2004-03-02 
> >14:42:47.854532793 -0700
> >@@ -48,6 +48,10 @@
> > /* Number of bytes of registers.  */
> > #define NUMREGBYTES (_LASTREG*8)
> > 
> >+#define PC_REGNUM	_PC	/* Program Counter */
> >+#define SP_REGNUM	_RSP	/* Stack Pointer */
> >+#define PTRACE_PC	rip	/* Program Counter, in ptrace regs. */
> 
> I would really like to keep this stuff out of kgdb.h since it may be 
> included by the user to pick up the BREAKPOINT() (which, by the way we 
> should standardize as I note that here it has () while not on the current 
> x86).

It's BREAKPOINT() everywhere:
$ grep BREAKPOINT include/asm-*/kgdb.h
include/asm-i386/kgdb.h:#define BREAKPOINT() asm("   int $3");
include/asm-ppc/kgdb.h:#define BREAKPOINT()             asm(".long 0x7d821008") /* twge r2, r2 */
include/asm-x86_64/kgdb.h:#define BREAKPOINT() asm("   int $3");

> Isn't there a kgdb_local.h which is used only by kdgd and friends?  We 
> really do want to keep the name space as clean as possible to prevent 
> possible conflicts.

The simple answer is you don't call BREAKPOINT() in your code anywhere.
You call breakpoint() or kgdb_schedule_breakpoint().
The split here is different in that <linux/kgdb.h> should be standalone
(it's not, _yet_).

But this is all an aside to my question. :)

-- 
Tom Rini
http://gate.crashing.org/~trini/