Commit Graph

17 Commits

Author SHA1 Message Date
John Baldwin
091e8307d0 Add stoppcbs[] arrays on Alpha and sparc64 and have each CPU save its
current context in the IPI_STOP handler so that we can get accurate stack
traces of threads on other CPUs on these two archs like we do now on i386
and amd64.

Tested on:	alpha, sparc64
2005-11-03 21:08:20 +00:00
Peter Wemm
40c9966a37 Commit something we found useful at work at one point. Add sysctls for
debug.kdb.panic and debug.kdb.trap alongside the existing debug.kdb.enter
sysctl.  'panic' causes a panic, and 'trap' causes a page fault.  We used
these to ensure that crash dumps succeed from those two common failure
modes.  This avoids the need for creating a 'panic' kld module.
2005-10-26 22:40:07 +00:00
John Baldwin
58553b9925 Rename the KDB_STOP_NMI kernel option to STOP_NMI and make it apply to all
IPI_STOP IPIs.
- Change the i386 and amd64 MD IPI code to send an NMI if STOP_NMI is
  enabled if an attempt is made to send an IPI_STOP IPI.  If the kernel
  option is enabled, there is also a sysctl to change the behavior at
  runtime (debug.stop_cpus_with_nmi which defaults to enabled).  This
  includes removing stop_cpus_nmi() and making ipi_nmi_selected() a
  private function for i386 and amd64.
- Fix ipi_all(), ipi_all_but_self(), and ipi_self() on i386 and amd64 to
  properly handle bitmapped IPIs as well as IPI_STOP IPIs when STOP_NMI is
  enabled.
- Fix ipi_nmi_handler() to execute the restart function on the first CPU
  that is restarted making use of atomic_readandclear() rather than
  assuming that the BSP is always included in the set of restarted CPUs.
  Also, the NMI handler didn't clear the function pointer meaning that
  subsequent stop and restarts could execute the function again.
- Define a new macro HAVE_STOPPEDPCBS on i386 and amd64 to control the use
  of stoppedpcbs[] and always enable it for i386 and amd64 instead of
  being dependent on KDB_STOP_NMI.  It works fine in both the NMI and
  non-NMI cases.
2005-10-24 21:04:19 +00:00
John Baldwin
6b1e0d75b0 - Various small whitespace and style nits.
- Use PCPU_GET(cpumask) in preference to 1 << PCPU_GET(cpuid) in a few
  places.
2005-10-24 20:31:04 +00:00
Robert Watson
667285c4e3 If KDB_STOP_NMI is compiled into the kernel, default
debug.kdb.stop_cpus_with_nmi to 1 rather than 0.

MFC after:	3 days
2005-09-27 21:12:05 +00:00
Peter Wemm
f0c6706de9 Move the KDB_STOP_NMI option from opt_global.h to opt_kdb.h
Approved by:	re
2005-06-29 23:23:16 +00:00
Doug White
fdc9713bf7 Implement an alternate method to stop CPUs when entering DDB. Normally we use
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
2005-04-30 20:01:00 +00:00
Warner Losh
9454b2d864 /* -> /*- for copyright notices, minor format tweaks as necessary 2005-01-06 23:35:40 +00:00
Stephan Uphoff
f742a1edcd Zero terminate empty sting in kdb_sysctl_available.
Approved by:    sam (mentor)
MFC after: 1 week
2004-10-21 01:11:25 +00:00
Marcel Moolenaar
e6aa723212 Fix a bug introduced in the previous commit: kdb_cpu_trap() gets to
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
2004-09-26 06:48:59 +00:00
Marcel Moolenaar
ddf4122592 Move makectx() after kdb_cpu_trap(), so the PCB will have possible MD
corrections made to the trapframe. This is more logical.
2004-09-17 22:27:23 +00:00
Robert Watson
d963815baf Make debug.kdb.stop_cpus also a TUNABLE() so it can be set prior to boot
to help debug early nasty hangs.
2004-08-22 15:10:52 +00:00
Robert Watson
d8939d82cb Add a new sysctl, debug.kdb.stop_cpus, which controls whether or not we
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
2004-08-15 02:06:27 +00:00
Marcel Moolenaar
3d4f313695 Add kdb_thr_from_pid(), which given a PID returns the first thread
in the process. This is useful when working from or with a process.
2004-07-21 04:49:48 +00:00
Marcel Moolenaar
3bcd2440db Make kdb_dbbe_select() available as an interface function. This allows
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.
2004-07-12 01:15:55 +00:00
Marcel Moolenaar
a8bfba1a27 Fix braino: Make sure there is a current backend before we return its
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)
2004-07-11 15:22:43 +00:00
Marcel Moolenaar
cbc174356c Introduce the KDB debugger frontend. The frontend provides a framework
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.
2004-07-10 18:40:12 +00:00