linux/arch/h8300
Tejun Heo 196779b9b4 dump_stack: consolidate dump_stack() implementations and unify their behaviors
Both dump_stack() and show_stack() are currently implemented by each
architecture.  show_stack(NULL, NULL) dumps the backtrace for the
current task as does dump_stack().  On some archs, dump_stack() prints
extra information - pid, utsname and so on - in addition to the
backtrace while the two are identical on other archs.

The usages in arch-independent code of the two functions indicate
show_stack(NULL, NULL) should print out bare backtrace while
dump_stack() is used for debugging purposes when something went wrong,
so it does make sense to print additional information on the task which
triggered dump_stack().

There's no reason to require archs to implement two separate but mostly
identical functions.  It leads to unnecessary subtle information.

This patch expands the dummy fallback dump_stack() implementation in
lib/dump_stack.c such that it prints out debug information (taken from
x86) and invokes show_stack(NULL, NULL) and drops arch-specific
dump_stack() implementations in all archs except blackfin.  Blackfin's
dump_stack() does something wonky that I don't understand.

Debug information can be printed separately by calling
dump_stack_print_info() so that arch-specific dump_stack()
implementation can still emit the same debug information.  This is used
in blackfin.

This patch brings the following behavior changes.

* On some archs, an extra level in backtrace for show_stack() could be
  printed.  This is because the top frame was determined in
  dump_stack() on those archs while generic dump_stack() can't do that
  reliably.  It can be compensated by inlining dump_stack() but not
  sure whether that'd be necessary.

* Most archs didn't use to print debug info on dump_stack().  They do
  now.

An example WARN dump follows.

 WARNING: at kernel/workqueue.c:4841 init_workqueues+0x35/0x505()
 Hardware name: empty
 Modules linked in:
 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.9.0-rc1-work+ #9
  0000000000000009 ffff88007c861e08 ffffffff81c614dc ffff88007c861e48
  ffffffff8108f50f ffffffff82228240 0000000000000040 ffffffff8234a03c
  0000000000000000 0000000000000000 0000000000000000 ffff88007c861e58
 Call Trace:
  [<ffffffff81c614dc>] dump_stack+0x19/0x1b
  [<ffffffff8108f50f>] warn_slowpath_common+0x7f/0xc0
  [<ffffffff8108f56a>] warn_slowpath_null+0x1a/0x20
  [<ffffffff8234a071>] init_workqueues+0x35/0x505
  ...

v2: CPU number added to the generic debug info as requested by s390
    folks and dropped the s390 specific dump_stack().  This loses %ksp
    from the debug message which the maintainers think isn't important
    enough to keep the s390-specific dump_stack() implementation.

    dump_stack_print_info() is moved to kernel/printk.c from
    lib/dump_stack.c.  Because linkage is per objecct file,
    dump_stack_print_info() living in the same lib file as generic
    dump_stack() means that archs which implement custom dump_stack()
    - at this point, only blackfin - can't use dump_stack_print_info()
    as that will bring in the generic version of dump_stack() too.  v1
    The v1 patch broke build on blackfin due to this issue.  The build
    breakage was reported by Fengguang Wu.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>	[s390 bits]
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Richard Kuo <rkuo@codeaurora.org>		[hexagon bits]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:02 -07:00
..
boot h8300: change to new flag variable 2011-03-17 14:02:55 +01:00
include Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-02-26 20:16:07 -08:00
kernel dump_stack: consolidate dump_stack() implementations and unify their behaviors 2013-04-30 17:04:02 -07:00
lib
mm mm/h8300: use common help functions to free reserved pages 2013-04-29 15:54:29 -07:00
platform sections: fix section conflicts in arch/h8300 2012-10-06 03:04:38 +09:00
defconfig kconfig: rename CONFIG_EMBEDDED to CONFIG_EXPERT 2011-01-20 17:02:05 -08:00
Kconfig idle: Remove GENERIC_IDLE_LOOP config switch 2013-04-17 10:39:38 +02:00
Kconfig.cpu timers: Fixup the Kconfig consolidation fallout 2012-05-21 23:43:46 +02:00
Kconfig.debug tree-wide: fix comment/printk typos 2010-11-01 15:38:34 -04:00
Kconfig.ide
Makefile
README h8300: Fix home page URL in h8300/README 2013-01-04 10:56:04 +01:00

linux-2.6 for H8/300 README
Yoshinori Sato <ysato@users.sourceforge.jp>

* Supported CPU
H8/300H and H8S

* Supported Target
1.simulator of GDB
  require patches.

2.AE 3068/AE 3069
  more information 
  MICROTRONIQUE <http://www.microtronique.com/>
  Akizuki Denshi Tsusho Ltd. <http://akizukidenshi.com/> (Japanese Only)

3.H8MAX 
  see http://ip-sol.jp/h8max/ (Japanese Only)

4.EDOSK2674
  see http://www.eu.renesas.com/products/mpumcu/tool/edk/support/edosk2674.html
      http://www.uclinux.org/pub/uClinux/ports/h8/HITACHI-EDOSK2674-HOWTO
      http://www.azpower.com/H8-uClinux/

* Toolchain Version
gcc-3.1 or higher and patch
see arch/h8300/tools_patch/README
binutils-2.12 or higher
gdb-5.2 or higher
The environment that can compile a h8300-elf binary is necessary.

* Userland Develop environment
used h8300-elf toolchains.
see http://www.uclinux.org/pub/uClinux/ports/h8/

* A few words of thanks
Porting to H8/300 serieses is support of Information-technology Promotion Agency, Japan.
I thank support.
and All developer/user.