a regular IPI vector, but this vector is blocked when interrupts are disabled.
With "options KDB_STOP_NMI" and debug.kdb.stop_cpus_with_nmi set, KDB will
send an NMI to each CPU instead. The code also has a context-stuffing
feature which helps ddb extract the state of processes running on the
stopped CPUs.
KDB_STOP_NMI is only useful with SMP and complains if SMP is not defined.
This feature only applies to i386 and amd64 at the moment, but could be
used on other architectures with the appropriate MD bits.
Submitted by: ups
the trapframe via kdb_frame, but kdb_frame was not initialized until
after the call to kdb_cpu_trap(). Ergo: kdb_cpu_trap() was moved too
far up.
Pointy hat: marcel
attempt to IPI other cpus when entering the debugger in order to stop
them while in the debugger. The default remains to issue the stop;
however, that can result in a hang if another cpu has interrupts disabled
and is spinning, since the IPI won't be received and the KDB will wait
indefinitely. We probably need to add a timeout, but this is a useful
stopgap in the mean time.
Reviewed by: marcel
changing the backend from outside the KDB frontend. For example from
within a backend. Rewrite kdb_sysctl_current to make use of this
function as well.
name in the debug.kdb.current sysctl. All other dereferences are
properly guarded, but this one was overlooked.
Reported by: Morten Rodal (morten at rodal dot no)
in which multiple (presumably different) debugger backends can be
configured and which provides basic services to those backends.
Besides providing services to backends, it also serves as the single
point of contact for any and all code that wants to make use of the
debugger functions, such as entering the debugger or handling of the
alternate break sequence. For this purpose, the frontend has been
made non-optional.
All debugger requests are forwarded or handed over to the current
backend, if applicable. Selection of the current backend is done by
the debug.kdb.current sysctl. A list of configured backends can be
obtained with the debug.kdb.available sysctl. One can enter the
debugger by writing to the debug.kdb.enter sysctl.
