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196779b9b4
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> |
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| Makefile | ||
| README.openrisc | ||
| TODO.openrisc | ||
OpenRISC Linux
==============
This is a port of Linux to the OpenRISC class of microprocessors; the initial
target architecture, specifically, is the 32-bit OpenRISC 1000 family (or1k).
For information about OpenRISC processors and ongoing development:
website http://openrisc.net
For more information about Linux on OpenRISC, please contact South Pole AB.
email: info@southpole.se
website: http://southpole.se
http://southpoleconsulting.com
---------------------------------------------------------------------
Build instructions for OpenRISC toolchain and Linux
===================================================
In order to build and run Linux for OpenRISC, you'll need at least a basic
toolchain and, perhaps, the architectural simulator. Steps to get these bits
in place are outlined here.
1) The toolchain can be obtained from openrisc.net. Instructions for building
a toolchain can be found at:
http://openrisc.net/toolchain-build.html
2) or1ksim (optional)
or1ksim is the architectural simulator which will allow you to actually run
your OpenRISC Linux kernel if you don't have an OpenRISC processor at hand.
git clone git://openrisc.net/jonas/or1ksim-svn
cd or1ksim
./configure --prefix=$OPENRISC_PREFIX
make
make install
3) Linux kernel
Build the kernel as usual
make ARCH=openrisc defconfig
make ARCH=openrisc
4) Run in architectural simulator
Grab the or1ksim platform configuration file (from the or1ksim source) and
together with your freshly built vmlinux, run your kernel with the following
incantation:
sim -f arch/openrisc/or1ksim.cfg vmlinux
---------------------------------------------------------------------
Terminology
===========
In the code, the following particles are used on symbols to limit the scope
to more or less specific processor implementations:
openrisc: the OpenRISC class of processors
or1k: the OpenRISC 1000 family of processors
or1200: the OpenRISC 1200 processor
---------------------------------------------------------------------
History
========
18. 11. 2003 Matjaz Breskvar (phoenix@bsemi.com)
initial port of linux to OpenRISC/or32 architecture.
all the core stuff is implemented and seams usable.
08. 12. 2003 Matjaz Breskvar (phoenix@bsemi.com)
complete change of TLB miss handling.
rewrite of exceptions handling.
fully functional sash-3.6 in default initrd.
a much improved version with changes all around.
10. 04. 2004 Matjaz Breskvar (phoenix@bsemi.com)
alot of bugfixes all over.
ethernet support, functional http and telnet servers.
running many standard linux apps.
26. 06. 2004 Matjaz Breskvar (phoenix@bsemi.com)
port to 2.6.x
30. 11. 2004 Matjaz Breskvar (phoenix@bsemi.com)
lots of bugfixes and enhancments.
added opencores framebuffer driver.
09. 10. 2010 Jonas Bonn (jonas@southpole.se)
major rewrite to bring up to par with upstream Linux 2.6.36