[PATCH v3 0/4] kdb: Fixes for btc

[Douglas Anderson]

This series has a few kdb fixes for back tracing on CPUs.  The
previous version[1] had only one patch, but while making v3 I found a
few cleanups that made sense to break into other pieces.

As with all things kdb / kgdb, this patch set tries to inch us towards
a better state of the world but doesn't attempt to solve all known
problems.

Please enjoy.

[1] https://lore.kernel.org/r/20190731183732.178134-1-dianders@xxxxxxxxxxxx

Changes in v3:
- Patch ("Remove unused DCPU_SSTEP definition") new for v3.
- Patch ("kdb: Remove unused "argcount" param from...") new for v3.
- Patch ("kdb: Fix "btc <cpu>" crash if the CPU...") new for v3.
- Use exception state instead of new dbg_slave_dumpstack_cpu var.
- Move horror to debug core, cleaning up control flow.
- Avoid need for timeout by only waiting for CPUs marked as slaves.

Changes in v2:
- Totally new approach; now arch agnostic.

Douglas Anderson (4):
  kgdb: Remove unused DCPU_SSTEP definition
  kdb: Remove unused "argcount" param from kdb_bt1(); make btaprompt
    bool
  kdb: Fix "btc <cpu>" crash if the CPU didn't round up
  kdb: Fix stack crawling on 'running' CPUs that aren't the master

 kernel/debug/debug_core.c | 34 ++++++++++++++
 kernel/debug/debug_core.h |  3 +-
 kernel/debug/kdb/kdb_bt.c | 94 +++++++++++++++++++--------------------
 3 files changed, 83 insertions(+), 48 deletions(-)

-- 
2.23.0.351.gc4317032e6-goog