On Thu, 13 Feb 2003 15:59:45 +0800,
"Zhang, Sonic" <sonic.zhang@xxxxxxxxx> wrote:
> Current implementation in kdb-v3.0-2.4.20 sees a local breakpoint as
>an equivalence of a global breakpoint. All CPUs share the same data
>structure for hardware debug registers. And each CPU sets its debug register
>for a hardware breakpoint, no matter whether it is a local one of the other
>CPUs.
Where do you get that from? kdb_bp_install_local() is
void
kdb_bp_install_local(struct pt_regs *regs)
{
int i;
for(i=0; i<KDB_MAXBPT; i++) {
if (KDB_DEBUG(BP)) {
kdb_printf("kdb_bp_install_local bp %d bp_enabled %d
bp_global %d cpu %d bp_cpu %d\n",
i, kdb_breakpoints[i].bp_enabled,
kdb_breakpoints[i].bp_global,
smp_processor_id(), kdb_breakpoints[i].bp_cpu);
}
if (kdb_breakpoints[i].bp_enabled
&& kdb_breakpoints[i].bp_cpu == smp_processor_id()
&& !kdb_breakpoints[i].bp_global){
kdba_installbp(regs, &kdb_breakpoints[i]);
}
}
}
That function is called for each cpu as it leaves kdb. It only
installs local breakpoints for the current cpu.
kdb_bp() has
if (hardware && !global) {
bp->bp_global = 0;
bp->bp_cpu = smp_processor_id();
}
marking local breakpoints by their cpu number.
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