[PATCHv3 00/50] Add log level to show_stack()

[Dmitry Safonov <dima@arista.com>]

Changes to v3:
- Collected more architectual Acks and Reviewed-by
- Fixed compilation on sparc64

Changes to v2:
- Removed excessive pr_cont("\n") (nits by Senozhatsky)
- Leave backtrace debugging messages with pr_debug()
  (noted by Russell King and Will Deacon)
- Correct microblaze_unwind_inner() declaration
  (Thanks to Michal Simek and kbuild test robot)
- Fix copy'n'paste typo in show_stack_loglvl() for sparc
  (kbuild robot)
- Fix backtrace output on xtensa
  (Thanks Max Filippov)
- Add loglevel to show_stack() on s390 (kbuild robot)
- Collected all Reviewed-by and Acked-by (thanks!)

v2: https://lore.kernel.org/linux-riscv/20200316143916.195608-1-dima@arista.com/
v1: https://lore.kernel.org/linux-riscv/20191106030542.868541-1-dima@arista.com/

Add log level argument to show_stack().
Done in three stages:
1. Introducing show_stack_loglvl() for every architecture
2. Migrating old users with an explicit log level
3. Renaming show_stack_loglvl() into show_stack()

Justification:
o It's a design mistake to move a business-logic decision
  into platform realization detail.
o I have currently two patches sets that would benefit from this work:
  Removing console_loglevel jumps in sysrq driver [1]
  Hung task warning before panic [2] - suggested by Tetsuo (but he
  probably didn't realise what it would involve).
o While doing (1), (2) the backtraces were adjusted to headers
  and other messages for each situation - so there won't be a situation
  when the backtrace is printed, but the headers are missing because
  they have lesser log level (or the reverse).
o As the result in (2) plays with console_loglevel for kdb are removed.

The least important for upstream, but maybe still worth to note that
every company I've worked in so far had an off-list patch to print
backtrace with the needed log level (but only for the architecture they
cared about).
If you have other ideas how you will benefit from show_stack() with
a log level - please, reply to this cover letter.

See also discussion on v1:
https://lore.kernel.org/linux-riscv/20191106083538.z5nlpuf64cigxigh@pathway.suse.cz/

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>

Thanks,
Dmitry

[1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u
[2]: https://lkml.kernel.org/r/41fd7652-df1f-26f6-aba0-b87ebae07db6@i-love.sakura.ne.jp

Dmitry Safonov (50):
  kallsyms/printk: Add loglvl to print_ip_sym()
  alpha: Add show_stack_loglvl()
  arc: Add show_stack_loglvl()
  arm/asm: Add loglvl to c_backtrace()
  arm: Add loglvl to unwind_backtrace()
  arm: Add loglvl to dump_backtrace()
  arm: Wire up dump_backtrace_{entry,stm}
  arm: Add show_stack_loglvl()
  arm64: Add loglvl to dump_backtrace()
  arm64: Add show_stack_loglvl()
  c6x: Add show_stack_loglvl()
  csky: Add show_stack_loglvl()
  h8300: Add show_stack_loglvl()
  hexagon: Add show_stack_loglvl()
  ia64: Pass log level as arg into ia64_do_show_stack()
  ia64: Add show_stack_loglvl()
  m68k: Add show_stack_loglvl()
  microblaze: Add loglvl to microblaze_unwind_inner()
  microblaze: Add loglvl to microblaze_unwind()
  microblaze: Add show_stack_loglvl()
  mips: Add show_stack_loglvl()
  nds32: Add show_stack_loglvl()
  nios2: Add show_stack_loglvl()
  openrisc: Add show_stack_loglvl()
  parisc: Add show_stack_loglvl()
  powerpc: Add show_stack_loglvl()
  riscv: Add show_stack_loglvl()
  s390: Add show_stack_loglvl()
  sh: Add loglvl to dump_mem()
  sh: Remove needless printk()
  sh: Add loglvl to printk_address()
  sh: Add loglvl to show_trace()
  sh: Add show_stack_loglvl()
  sparc: Add show_stack_loglvl()
  um/sysrq: Remove needless variable sp
  um: Add show_stack_loglvl()
  unicore32: Remove unused pmode argument in c_backtrace()
  unicore32: Add loglvl to c_backtrace()
  unicore32: Add show_stack_loglvl()
  x86: Add missing const qualifiers for log_lvl
  x86: Add show_stack_loglvl()
  xtensa: Add loglvl to show_trace()
  xtensa: Add show_stack_loglvl()
  sysrq: Use show_stack_loglvl()
  x86/amd_gart: Print stacktrace for a leak with KERN_ERR
  power: Use show_stack_loglvl()
  kdb: Don't play with console_loglevel
  sched: Print stack trace with KERN_INFO
  kernel: Use show_stack_loglvl()
  kernel: Rename show_stack_loglvl() => show_stack()

 arch/alpha/kernel/traps.c            | 22 +++++++--------
 arch/arc/include/asm/bug.h           |  3 ++-
 arch/arc/kernel/stacktrace.c         | 17 +++++++-----
 arch/arc/kernel/troubleshoot.c       |  2 +-
 arch/arm/include/asm/bug.h           |  3 ++-
 arch/arm/include/asm/traps.h         |  3 ++-
 arch/arm/include/asm/unwind.h        |  3 ++-
 arch/arm/kernel/traps.c              | 39 +++++++++++++++------------
 arch/arm/kernel/unwind.c             |  5 ++--
 arch/arm/lib/backtrace-clang.S       |  9 +++++--
 arch/arm/lib/backtrace.S             | 14 +++++++---
 arch/arm64/include/asm/stacktrace.h  |  3 ++-
 arch/arm64/kernel/process.c          |  2 +-
 arch/arm64/kernel/traps.c            | 17 ++++++------
 arch/c6x/kernel/traps.c              | 16 ++++++-----
 arch/csky/kernel/dumpstack.c         |  9 ++++---
 arch/csky/kernel/ptrace.c            |  4 +--
 arch/h8300/kernel/traps.c            | 12 ++++-----
 arch/hexagon/kernel/traps.c          | 25 ++++++++---------
 arch/ia64/include/asm/ptrace.h       |  1 -
 arch/ia64/kernel/mca.c               |  2 +-
 arch/ia64/kernel/process.c           | 17 ++++++------
 arch/m68k/kernel/traps.c             | 13 ++++-----
 arch/microblaze/include/asm/unwind.h |  3 ++-
 arch/microblaze/kernel/stacktrace.c  |  4 +--
 arch/microblaze/kernel/traps.c       | 12 ++++-----
 arch/microblaze/kernel/unwind.c      | 40 +++++++++++++++++-----------
 arch/mips/kernel/traps.c             | 35 ++++++++++++------------
 arch/nds32/kernel/traps.c            | 15 ++++++-----
 arch/nios2/kernel/traps.c            | 17 ++++++------
 arch/openrisc/kernel/traps.c         | 12 +++++----
 arch/parisc/kernel/traps.c           | 24 ++++++++---------
 arch/powerpc/kernel/process.c        | 15 ++++++-----
 arch/powerpc/kernel/stacktrace.c     |  2 +-
 arch/riscv/kernel/stacktrace.c       |  9 ++++---
 arch/s390/kernel/dumpstack.c         | 13 ++++-----
 arch/sh/include/asm/kdebug.h         |  6 +++--
 arch/sh/include/asm/processor_32.h   |  2 +-
 arch/sh/kernel/dumpstack.c           | 36 ++++++++++++-------------
 arch/sh/kernel/process_32.c          |  2 +-
 arch/sh/kernel/process_64.c          |  3 +--
 arch/sh/kernel/traps.c               |  4 +--
 arch/sh/mm/fault.c                   |  2 +-
 arch/sparc/kernel/process_32.c       | 10 +++----
 arch/sparc/kernel/process_64.c       |  2 +-
 arch/sparc/kernel/traps_64.c         |  9 ++++---
 arch/um/drivers/mconsole_kern.c      |  2 +-
 arch/um/kernel/sysrq.c               | 23 ++++++++--------
 arch/unicore32/kernel/setup.h        |  2 +-
 arch/unicore32/kernel/traps.c        | 34 +++++++++++------------
 arch/unicore32/lib/backtrace.S       | 24 +++++++++++------
 arch/x86/include/asm/stacktrace.h    |  2 +-
 arch/x86/kernel/amd_gart_64.c        |  2 +-
 arch/x86/kernel/dumpstack.c          |  9 ++++---
 arch/xtensa/kernel/traps.c           | 22 ++++++++-------
 drivers/base/power/main.c            |  2 +-
 drivers/tty/sysrq.c                  |  2 +-
 include/linux/kallsyms.h             |  4 +--
 include/linux/sched/debug.h          |  3 ++-
 kernel/debug/kdb/kdb_bt.c            | 15 ++++++-----
 kernel/locking/lockdep.c             |  4 +--
 kernel/locking/rtmutex-debug.c       |  2 +-
 kernel/sched/core.c                  |  8 +++---
 kernel/trace/ftrace.c                |  8 +++---
 lib/dump_stack.c                     |  2 +-
 tools/include/linux/kallsyms.h       |  2 +-
 66 files changed, 375 insertions(+), 315 deletions(-)

-- 
2.26.0