Currently kernel never set KGDB_REASON_NMI. We do now, when we enter
KGDB/KDB from an NMI.
This is not to be confused with kgdb_nmicallback(), NMI callback is
an entry for the slave CPUs during CPUs roundup, but REASON_NMI is the
entry for the master CPU.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Having the CPU in the more prompt is completely redundent vs the
standard kdb prompt, and it also wastes 32 bytes on the stack.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
This code cleanup was missed in the original kdb merge, and this code
is simply not used at all. The code that was previously used to set
the KDB_FLAG_ONLY_DO_DUMP was removed prior to the initial kdb merge.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The locked variants are prone to deadlocks (suppose we got to the
debugger w/ the logbuf lock held), so let's switch to nolock variants.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kgdb dmesg command is broken after the printk rework. The old logic
in kdb code makes no sense in terms of current printk/logging storage
format, and KDB simply hangs forever.
This patch revives the command by switching to kmsg_dumper iterator.
The code is now much more simpler and shorter.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull KGDB/KDB regression fixes from Jason Wessel:
- Fix a Smatch warning that appeared in the 3.4 merge window
- Fix kgdb test suite with SMP for all archs without HW single stepping
- Fix kgdb sw breakpoints with CONFIG_DEBUG_RODATA=y limitations on x86
- Fix oops on kgdb test suite with CONFIG_DEBUG_RODATA
- Fix kgdb test suite with SMP for all archs with HW single stepping
* tag 'for_linus-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
x86,kgdb: Fix DEBUG_RODATA limitation using text_poke()
kgdb,debug_core: pass the breakpoint struct instead of address and memory
kgdbts: (2 of 2) fix single step awareness to work correctly with SMP
kgdbts: (1 of 2) fix single step awareness to work correctly with SMP
kgdbts: Fix kernel oops with CONFIG_DEBUG_RODATA
kdb: Fix smatch warning on dbg_io_ops->is_console
There is extra state information that needs to be exposed in the
kgdb_bpt structure for tracking how a breakpoint was installed. The
debug_core only uses the the probe_kernel_write() to install
breakpoints, but this is not enough for all the archs. Some arch such
as x86 need to use text_poke() in order to install a breakpoint into a
read only page.
Passing the kgdb_bpt structure to kgdb_arch_set_breakpoint() and
kgdb_arch_remove_breakpoint() allows other archs to set the type
variable which indicates how the breakpoint was installed.
Cc: stable@vger.kernel.org # >= 2.6.36
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The Smatch tool warned that the change from commit b8adde8dd
(kdb: Avoid using dbg_io_ops until it is initialized) should
add another null check later in the kdb_printf().
It is worth noting that the second use of dbg_io_ops->is_console
is protected by the KDB_PAGER state variable which would only
get set when kdb is fully active and initialized. If we
ever encounter changes or defects in the KDB_PAGER state
we do not want to crash the kernel in a kdb_printf/printk.
CC: Tim Bird <tim.bird@am.sony.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Pull "Disintegrate and delete asm/system.h" from David Howells:
"Here are a bunch of patches to disintegrate asm/system.h into a set of
separate bits to relieve the problem of circular inclusion
dependencies.
I've built all the working defconfigs from all the arches that I can
and made sure that they don't break.
The reason for these patches is that I recently encountered a circular
dependency problem that came about when I produced some patches to
optimise get_order() by rewriting it to use ilog2().
This uses bitops - and on the SH arch asm/bitops.h drags in
asm-generic/get_order.h by a circuituous route involving asm/system.h.
The main difficulty seems to be asm/system.h. It holds a number of
low level bits with no/few dependencies that are commonly used (eg.
memory barriers) and a number of bits with more dependencies that
aren't used in many places (eg. switch_to()).
These patches break asm/system.h up into the following core pieces:
(1) asm/barrier.h
Move memory barriers here. This already done for MIPS and Alpha.
(2) asm/switch_to.h
Move switch_to() and related stuff here.
(3) asm/exec.h
Move arch_align_stack() here. Other process execution related bits
could perhaps go here from asm/processor.h.
(4) asm/cmpxchg.h
Move xchg() and cmpxchg() here as they're full word atomic ops and
frequently used by atomic_xchg() and atomic_cmpxchg().
(5) asm/bug.h
Move die() and related bits.
(6) asm/auxvec.h
Move AT_VECTOR_SIZE_ARCH here.
Other arch headers are created as needed on a per-arch basis."
Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that. We'll find out anything that got broken and fix it..
* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
Delete all instances of asm/system.h
Remove all #inclusions of asm/system.h
Add #includes needed to permit the removal of asm/system.h
Move all declarations of free_initmem() to linux/mm.h
Disintegrate asm/system.h for OpenRISC
Split arch_align_stack() out from asm-generic/system.h
Split the switch_to() wrapper out of asm-generic/system.h
Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
Create asm-generic/barrier.h
Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
Disintegrate asm/system.h for Xtensa
Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
Disintegrate asm/system.h for Tile
Disintegrate asm/system.h for Sparc
Disintegrate asm/system.h for SH
Disintegrate asm/system.h for Score
Disintegrate asm/system.h for S390
Disintegrate asm/system.h for PowerPC
Disintegrate asm/system.h for PA-RISC
Disintegrate asm/system.h for MN10300
...
Remove all #inclusions of asm/system.h preparatory to splitting and killing
it. Performed with the following command:
perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: David Howells <dhowells@redhat.com>
Pull KGDB/KDB updates from Jason Wessel:
"Fixes:
- Fix KDB keyboard repeat scan codes and leaked keyboard events
- Fix kernel crash with kdb_printf() for users who compile new
kdb_printf()'s in early code
- Return all segment registers to gdb on x86_64
Features:
- KDB/KGDB hook the reboot notifier and end user can control if it
stops, detaches or does nothing (updated docs as well)
- Notify users who use CONFIG_DEBUG_RODATA to use hw breakpoints"
* tag 'for_linus-3.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
kdb: Add message about CONFIG_DEBUG_RODATA on failure to install breakpoint
kdb: Avoid using dbg_io_ops until it is initialized
kgdb,debug_core: add the ability to control the reboot notifier
KDB: Fix usability issues relating to the 'enter' key.
kgdb,debug-core,gdbstub: Hook the reboot notifier for debugger detach
kgdb: Respect that flush op is optional
kgdb: x86: Return all segment registers also in 64-bit mode
On x86, if CONFIG_DEBUG_RODATA is set, one cannot set breakpoints
via KDB. Apparently this is a well-known problem, as at least one distribution
now ships with both KDB enabled and CONFIG_DEBUG_RODATA=y for security reasons.
This patch adds an printk message to the breakpoint failure case,
in order to provide suggestions about how to use the debugger.
Reported-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Tim Bird <tim.bird@am.sony.com>
This fixes a bug with setting a breakpoint during kdb initialization
(from kdb_cmds). Any call to kdb_printf() before the initialization
of the kgdboc serial console driver (which happens much later during
bootup than kdb_init), results in kernel panic due to the use of
dbg_io_ops before it is initialized.
Signed-off-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Sometimes it is desirable to stop the kernel debugger before allowing
a system to reboot either with kdb or kgdb. This patch adds the
ability to turn the reboot notifier on and off or enter the debugger
and stop kernel execution before rebooting.
It is possible to change the setting after booting the kernel with the
following:
echo 1 > /sys/module/debug_core/parameters/kgdbreboot
It is also possible to change this setting using kdb / kgdb to
manipulate the variable directly.
Using KDB:
mm kgdbreboot 1
Using gdb:
set kgdbreboot=1
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
This fixes the following problems:
1) Typematic-repeat of 'enter' gives warning message
and leaks make/break if KDB exits. Repeats
look something like 0x1c 0x1c .... 0x9c
2) Use of 'keypad enter' gives warning message and
leaks the ENTER break/make code out if KDB exits.
KP ENTER repeats look someting like 0xe0 0x1c
0xe0 0x1c ... 0xe0 0x9c.
3) Lag on the order of seconds between "break" and "make" when
expecting the enter "break" code. Seen under virtualized
environments such as VMware ESX.
The existing special enter handler tries to glob the enter break code,
but this fails if the other (KP) enter was used, or if there was a key
repeat. It also fails if you mashed some keys along with enter, and
you ended up with a non-enter make or non-enter break code coming
after the enter make code. So first, we modify the handler to handle
these cases. But performing these actions on every enter is annoying
since now you can't hold ENTER down to scroll <more>d messages in
KDB. Since this special behaviour is only necessary to handle the
exiting KDB ('g' + ENTER) without leaking scancodes to the OS. This
cleanup needs to get executed anytime the kdb_main loop exits.
Tested on QEMU. Set a bp on atkbd.c to verify no scan code was leaked.
Cc: Andrei Warkentin <andreiw@vmware.com>
[jason.wessel@windriver.com: move cleanup calls to kdb_main.c]
Signed-off-by: Andrei Warkentin <andrey.warkentin@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The gdbstub and kdb should get detached if the system is rebooting.
Calling gdbstub_exit() will set the proper debug core state and send a
message to any debugger that is connected to correctly detach.
An attached debugger will receive the exit code from
include/linux/reboot.h based on SYS_HALT, SYS_REBOOT, etc...
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Not all kgdb I/O drivers implement a flush operation. Adjust
gdbstub_exit accordingly.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
module_ref contains two "unsigned int" fields.
Thats now too small, since some machines can open more than 2^32 files.
Check commit 518de9b39e (fs: allow for more than 2^31 files) for
reference.
We can add an aligned(2 * sizeof(unsigned long)) attribute to force
alloc_percpu() allocating module_ref areas in single cache lines.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Rusty Russell <rusty@rustcorp.com.au>
CC: Tejun Heo <tj@kernel.org>
CC: Robin Holt <holt@sgi.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
Revert "tracing: Include module.h in define_trace.h"
irq: don't put module.h into irq.h for tracking irqgen modules.
bluetooth: macroize two small inlines to avoid module.h
ip_vs.h: fix implicit use of module_get/module_put from module.h
nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
include: replace linux/module.h with "struct module" wherever possible
include: convert various register fcns to macros to avoid include chaining
crypto.h: remove unused crypto_tfm_alg_modname() inline
uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
pm_runtime.h: explicitly requires notifier.h
linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
miscdevice.h: fix up implicit use of lists and types
stop_machine.h: fix implicit use of smp.h for smp_processor_id
of: fix implicit use of errno.h in include/linux/of.h
of_platform.h: delete needless include <linux/module.h>
acpi: remove module.h include from platform/aclinux.h
miscdevice.h: delete unnecessary inclusion of module.h
device_cgroup.h: delete needless include <linux/module.h>
net: sch_generic remove redundant use of <linux/module.h>
net: inet_timewait_sock doesnt need <linux/module.h>
...
Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in
- drivers/media/dvb/frontends/dibx000_common.c
- drivers/media/video/{mt9m111.c,ov6650.c}
- drivers/mfd/ab3550-core.c
- include/linux/dmaengine.h
These files were getting <linux/module.h> via an implicit non-obvious
path, but we want to crush those out of existence since they cost
time during compiles of processing thousands of lines of headers
for no reason. Give them the lightweight header that just contains
the EXPORT_SYMBOL infrastructure.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
kdb,kgdb: Allow arbitrary kgdb magic knock sequences
kdb: Remove all references to DOING_KGDB2
kdb,kgdb: Implement switch and pass buffer from kdb -> gdb
kdb: cleanup unused variables missed in the original kdb merge
