If the kernel debugger was configured, attached and started with
kgdbwait, the hardware breakpoint registers should get restored by the
kgdb code which is managing the dr registers.
CC: x86@kernel.org
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
It is not possible to use the hw_breakpoint.c API prior to mm_init(),
but it is possible to use hardware breakpoints with the kernel
debugger.
Prior to smp_init() it is possible to simply write to the dr registers
of the boot cpu directly. This can be used up until the
kgdb_arch_late() is invoked, at which point the standard hw_breakpoint.c
API will get used.
CC: Frederic Weisbecker <fweisbec@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The kernel debugger can operate well before mm_init(), but the x86
hardware breakpoint code which uses the perf api requires that the
kernel allocators are initialized.
This means the kernel debug core needs to provide an optional arch
specific call back to allow the initialization functions to run after
the kernel has been further initialized.
The kdb shell already had a similar restriction with an early
initialization and late initialization. The kdb_init() was moved into
the debug core's version of the late init which is called
dbg_late_init();
CC: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Allow the x86 arch to have early exception processing for the purpose
of debugging via the kgdb.
Signed-off-by: Jan Kiszka <jan.kiszka@web.de>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
It is highly desirable to trap into kdb on panic. The debug core will
attempt to register as the first in line for the panic notifier.
CC: Ingo Molnar <mingo@elte.hu>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Certain calls from the kdb shell will call out to printk(), and any of
these calls should get vectored back to the kdb_printf() so that the
kdb pager and processing can be used, as well as to properly channel
I/O to the polled I/O devices.
CC: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
If kdb is open on a serial port that is not actually a console make
sure to call the poll routines to emit and receive characters.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Martin Hicks <mort@sgi.com>
Some kgdb I/O modules require the ability to create a breakpoint
tasklet, such as kgdboc and external modules such as kgdboe. The
breakpoint tasklet is used as an asynchronous entry point into the
debugger which will have a different function scope than the current
execution path where it might not be safe to have an inline
breakpoint. This is true of some of the kgdb I/O drivers which share
code with kgdb and rest of the kernel users.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
The only way the debugger can handle a trap in inside rcu_lock,
notify_die, or atomic_notifier_call_chain without a recursive fault is
to have a low level "first opportunity handler" do_trap_or_bp() handler.
Generally this will be something the vast majority of folks will not
need, but for those who need it, it is added as a kernel .config
option called KGDB_LOW_LEVEL_TRAP.
Also added was a die notification for oops such that kdb can catch an
oops for analysis.
There appeared to be no obvious way to pass the struct pt_regs from
the original exception back to the stack back tracer, so a special
case was added to show_stack() for when kdb is active because you
generally desire to generally look at the back trace of the original
exception.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
The only way the debugger can handle a trap in inside rcu_lock,
notify_die, or atomic_notifier_call_chain without a recursive fault is
to allow the kernel debugger to handle the exception first in
program_check_exception().
The other change here is to make sure that kgdb_handle_exception() is
called with correct parameters when catching an oops, because kdb
needs to know if the entry was an oops, single step, or breakpoint
exception.
[benh@kernel.crashing.org: move debugger_bpt instead of #ifdef]
CC: Paul Mackerras <paulus@samba.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The only way the debugger can handle a trap in inside rcu_lock,
notify_die, or atomic_notifier_call_chain without a triple fault is
to have a low level "first opportunity handler" in the int3 exception
handler.
Generally this will be something the vast majority of folks will not
need, but for those who need it, it is added as a kernel .config
option called KGDB_LOW_LEVEL_TRAP.
CC: Ingo Molnar <mingo@elte.hu>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: H. Peter Anvin <hpa@zytor.com>
CC: x86@kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Remove all the references to the kgdb_post_primary_code. This
function serves no useful purpose because you can obtain the same
information from the "struct kgdb_state *ks" from with in the
debugger, if for some reason you want the data.
Also remove the unintentional duplicate assignment for ks->ex_vector.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Update the kgdb docs to reflect the new directory structure and API.
Merge in the kdb shell information.
[Randy Dunlap <rdunlap@xenotime.net>: grammatical corrections]
CC: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
This patch adds in the kdb PS/2 keyboard driver. This was mostly a
direct port from the original kdb where I cleaned up the code against
checkpatch.pl and added the glue to stitch it into kgdb.
This patch also enables early kdb debug via kgdbwait and the keyboard.
All the access to configure kdb using either a serial console or the
keyboard is done via kgdboc.
If you want to use only the keyboard and want to break in early you
would add to your kernel command arguments:
kgdboc=kbd kgdbwait
If you wanted serial and or the keyboard access you could use:
kgdboc=kbd,ttyS0
You can also configure kgdboc as a kernel module or at run time with
the sysfs where you can activate and deactivate kgdb.
Turn it on:
echo kbd,ttyS0 > /sys/module/kgdboc/parameters/kgdboc
Turn it off:
echo "" > /sys/module/kgdboc/parameters/kgdboc
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
One of the driving forces behind integrating another front end (kdb)
to the debug core is to allow front end commands to be accessible via
gdb's monitor command. It is true that you could write gdb macros to
get certain data, but you may want to just use gdb to access the
commands that are available in the kdb front end.
This patch implements the Rcmd gdb stub packet. In gdb you access
this with the "monitor" command. For instance you could type "monitor
help", "monitor lsmod" or "monitor ps A" etc...
There is no error checking or command restrictions on what you can and
cannot access at this point. Doing something like trying to set
breakpoints with the monitor command is going to cause nothing but
problems. Perhaps in the future only the commands that are actually
known to work with the gdb monitor command will be available.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Allow kgdboc to work on sparc hardware with the Zilog serial chips.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: David S. Miller <davem@davemloft.net>
The sci_poll_get_char() needs to return immediately if there is no
input from the chip to process, and must return a value of
NO_POLL_CHAR.
This allows kgdboc to process multiple polled devices while kgdb is
active.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
The design of the kdb shell requires that every device that can
provide input to kdb have a polling routine that exits immediately if
there is no character available. This is required in order to get the
page scrolling mechanism working.
Changing the kernel debugger I/O API to require all polling character
routines to exit immediately if there is no data allows the kernel
debugger to process multiple input channels.
NO_POLL_CHAR will be the return code to the polling routine when ever
there is no character available.
CC: linux-serial@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
These are the minimum changes to the kgdb core in order to enable an
API to connect a new front end (kdb) to the debug core.
This patch introduces the dbg_kdb_mode variable controls where the
user level I/O is routed. It will be routed to the gdbstub (kgdb) or
to the kdb front end which is a simple shell available over the kgdboc
connection.
You can switch back and forth between kdb or the gdb stub mode of
operation dynamically. From gdb stub mode you can blindly type
"$3#33", or from the kdb mode you can enter "kgdb" to switch to the
gdb stub.
The logic in the debug core depends on kdb to look for the typical gdb
connection sequences and return immediately with KGDB_PASS_EVENT if a
gdb serial command sequence is detected. That should allow a
reasonably seamless transition between kdb -> gdb without leaving the
kernel exception state. The two gdb serial queries that kdb is
responsible for detecting are the "?" and "qSupported" packets.
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Martin Hicks <mort@sgi.com>
This patch contains the hooks and instrumentation into kernel which
live outside the kernel/debug directory, which the kdb core
will call to run commands like lsmod, dmesg, bt etc...
CC: linux-arch@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Martin Hicks <mort@sgi.com>
This patch contains only the kdb core. Because the change set was
large, it was split. The next patch in the series includes the
instrumentation into the core kernel which are mainly helper functions
for kdb.
This work is directly derived from kdb v4.4 found at:
ftp://oss.sgi.com/projects/kdb/download/v4.4/
The kdb internals have been re-organized to make them mostly platform
independent and to connect everything to the debug core which is used by
gdbstub (which has long been known as kgdb).
The original version of kdb was 58,000 lines worth of changes to
support x86. From that implementation only the kdb shell, and basic
commands for memory access, runcontrol, lsmod, and dmesg where carried
forward.
This is a generic implementation which aims to cover all the current
architectures using the kgdb core: ppc, arm, x86, mips, sparc, sh and
blackfin. More archictectures can be added by implementing the
architecture specific kgdb functions.
[mort@sgi.com: Compile fix with hugepages enabled]
[mort@sgi.com: Clean breakpoint code renaming kdba_ -> kdb_]
[mort@sgi.com: fix new line after printing registers]
[mort@sgi.com: Remove the concept of global vs. local breakpoints]
[mort@sgi.com: Rework kdb_si_swapinfo to use more generic name]
[mort@sgi.com: fix the information dump macros, remove 'arch' from the names]
[sfr@canb.auug.org.au: include fixup to include linux/slab.h]
CC: linux-arch@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Martin Hicks <mort@sgi.com>
The new debug core api requires all architectures that use to debug
core to implement a function to set the program counter.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Sonic Zhang <sonic.zhang@analog.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Implement kgdb_arch_pc() which adjusts the pc if it needs to be
adjusted after a software breakpoint trap.
Implement kgdb_arch_set_pc() which is a new required function in the
kgdb debug core.
When processing a single step return zero in the error exception field
so that the debug core can distinguish between a single step trap and
a breakpoint trap generically.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
The new debug core api requires all architectures that use to debug
core to implement a function to set the program counter.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: David S. Miller <davem@davemloft.net>
Split the former kernel/kgdb.c into debug_core.c which contains the
kernel debugger exception logic and to the gdbstub.c which contains
the logic for allowing gdb to talk to the debug core.
This also created a private include file called debug_core.h which
contains all the definitions to glue the debug_core to any other
debugger connections.
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Move kgdb.c in preparation to separate the gdbstub from the debug
core and exception handling.
CC: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
* 'acpica' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (22 commits)
ACPI: fix early DSDT dmi check warnings on ia64
ACPICA: Update version to 20100428.
ACPICA: Update/clarify some parameter names associated with acpi_handle
ACPICA: Rename acpi_ex_system_do_suspend->acpi_ex_system_do_sleep
ACPICA: Prevent possible allocation overrun during object copy
ACPICA: Split large file, evgpeblk
ACPICA: Add GPE support for dynamically loaded ACPI tables
ACPICA: Clarify/rename some root table descriptor fields
ACPICA: Update version to 20100331.
ACPICA: Minimize the differences between linux GPE code and ACPICA code base
ACPI: add boot option acpi=copy_dsdt to fix corrupt DSDT
ACPICA: Update DSDT copy/detection.
ACPICA: Add subsystem option to force copy of DSDT to local memory
ACPICA: Add detection of corrupted/replaced DSDT
ACPICA: Add write support for DataTable operation regions
ACPICA: Fix for acpi_reallocate_root_table for incorrect root table copy
ACPICA: Update comments/headers, no functional change
ACPICA: Update version to 20100304
ACPICA: Fix for possible fault in acpi_ex_release_mutex
ACPICA: Standardize integer output for ACPICA warnings/errors
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6: (250 commits)
ALSA: hda: Storage class should be before const qualifier
ASoC: tpa6130a2: Remove CPVSS and HPVdd supplies
ASoC: tpa6130a2: Define output pins with SND_SOC_DAPM_OUTPUT
ASoC: sdp4430 - add sdp4430 pcm ops to DAI.
ASoC: TWL6040: Enable earphone path in codec
ASoC: SDP4430: Add support for Earphone speaker
ASoC: SDP4430: Add sdp4430 machine driver
ASoC: tlv320dac33: Avoid powering off while in BIAS_OFF
ASoC: tlv320dac33: Use dev_dbg in dac33_hard_power function
ALSA: sound/pci/asihpi: Use kzalloc
ALSA: hdmi - dont fail on extra nodes
ALSA: intelhdmi - add id for the CougarPoint chipset
ALSA: intelhdmi - user friendly codec name
ALSA: intelhdmi - add dependency on SND_DYNAMIC_MINORS
ALSA: asihpi: incorrect range check
ALSA: asihpi: testing the wrong variable
ALSA: es1688: add pedantic range checks
ARM: McBSP: Add support for omap4 in McBSP driver
ARM: McBSP: Fix request for irq in OMAP4
OMAP: McBSP: Add 32-bit mode support
...
* 'for-linus/i2c-2635' of git://git.fluff.org/bjdooks/linux: (21 commits)
i2c-highlander: remover superflous variable
i2c-ibm-iic: drop NO_IRQ
i2c-cpm: drop NO_IRQ
i2c-mpc: drop NO_IRQ
MAINTAINERS: add i2c tree for embedded platforms
i2c-pxa: only define 'blue_murder'-function if DEBUG is #defined
i2c-pxa: remove unused macro
i2c-nomadik: fix operator precedence warning
i2c-nomadik: release region when removed
OMAP3: I2C: Clean up Errata 1p153 handling
OMAP2/3: I2C: Errata ID i207: Clear wrong RDR interrupt
omap: i2c: add a timeout to the busy waiting
omap: i2c: make errata 1.153 workaround a separate function
i2c-omap: add mpu wake up latency constraint in i2c
omap: i2c: Add i2c support on omap4 platform
i2c-bfin-twi: return completion in interrupt for smbus quick transfers
i2c-bfin-twi: remove redundant retry
i2c-bfin-twi: fix lost interrupts at high speeds
i2c-bfin-twi: add debug output for error status
i2c-bfin-twi: integrate timeout timer with completion interface
...
* 'v4l_for_2.6.35' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6: (534 commits)
V4L/DVB (13554a): v4l: Use the video_drvdata function in drivers
V4L/DVB: vivi and mem2mem_testdev need slab.h to build
V4L/DVB: tm6000: bugfix image position
V4L/DVB: IR/imon: remove dead IMON_KEY_RELEASE_OFFSET
V4L/DVB: tm6000: README - add vbi
V4L/DVB: Fix unlock logic at medusa_video_init
V4L/DVB: fix dvb frontend lockup
V4L/DVB: s2255drv: remove dead code
V4L/DVB: s2255drv: return if vdev not found
V4L/DVB: ov511: cleanup: remove unneeded null check
V4L/DVB: media/mem2mem: dereferencing free memory
V4L/DVB: media/IR: Add missing include file to rc-map.c
V4L/DVB: dvb/stv6110x: cleanup error handling
V4L/DVB: ngene: Add lgdt3303 and mt2131 deps to Kconfig
V4L/DVB: ngene: start separating out DVB functions into separate file
V4L/DVB: ngene: split out card specific code into a separate file
V4L/DVB: ngene: split out i2c code into a separate file
V4L/DVB: ngene: add initial support for digital side of Avermedia m780
V4L/DVB: ngene: properly support boards where channel 0 isn't a TS input
V4L-DVB: ngene: make sure that tuner headers are included
...
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev: (49 commits)
libata-sff: separate out BMDMA qc_issue
libata-sff: prd is BMDMA specific
libata-sff: ata_sff_[dumb_]qc_prep are BMDMA specific
libata-sff: separate out BMDMA EH
libata-sff: port_task is SFF specific
libata-sff: ap->[last_]ctl are SFF specific
libata-sff: rename ap->ops->drain_fifo() to sff_drain_fifo()
libata-sff: introduce ata_sff_init/exit() and ata_sff_port_init()
libata-sff: clean up BMDMA initialization
libata-sff: clean up inheritance in several drivers
libata-sff: reorder SFF/BMDMA functions
sata_inic162x: kill PORT_PRD_ADDR initialization
libata: kill ATA_FLAG_DISABLED
libata-sff: kill unused prototype and make ata_dev_select() static
libata-sff: update bmdma host bus error handling
sata_mv: remove unnecessary initialization
sata_inic162x: inic162x is not dependent on CONFIG_ATA_SFF
pata_sch: use ata_pci_sff_init_one()
pata_sil680: Do our own exec_command posting
libata: Remove excess delay in the tf_load path
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (44 commits)
vlynq: make whole Kconfig-menu dependant on architecture
add descriptive comment for TIF_MEMDIE task flag declaration.
EEPROM: max6875: Header file cleanup
EEPROM: 93cx6: Header file cleanup
EEPROM: Header file cleanup
agp: use NULL instead of 0 when pointer is needed
rtc-v3020: make bitfield unsigned
PCI: make bitfield unsigned
jbd2: use NULL instead of 0 when pointer is needed
cciss: fix shadows sparse warning
doc: inode uses a mutex instead of a semaphore.
uml: i386: Avoid redefinition of NR_syscalls
fix "seperate" typos in comments
cocbalt_lcdfb: correct sections
doc: Change urls for sparse
Powerpc: wii: Fix typo in comment
i2o: cleanup some exit paths
Documentation/: it's -> its where appropriate
UML: Fix compiler warning due to missing task_struct declaration
UML: add kernel.h include to signal.c
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: change cancel_work_sync() to clear work->data
workqueue: warn about flush_scheduled_work()
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
ia64: add sparse annotation to __ia64_per_cpu_var()
percpu: implement kernel memory based chunk allocation
percpu: move vmalloc based chunk management into percpu-vm.c
percpu: misc preparations for nommu support
percpu: reorganize chunk creation and destruction
percpu: factor out pcpu_addr_in_first/reserved_chunk() and update per_cpu_ptr_to_phys()
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
IB/core: Use kmemdup() instead of kmalloc()+memcpy()
IB/iser: Fix error flow in iser_create_ib_conn_res()
IB/iser: Enhance disconnection logic for multi-pathing
IB/iser: Remove buggy back-pointer setting
IB/iser: Add asynchronous event handler
MAINTAINERS: Add cxgb4 and iw_cxgb4 entries
RDMA/cxgb3: Shrink .text with compile-time init of handlers arrays
IPoIB: Allow disabling/enabling TSO on the fly through ethtool
IB/mlx4: Add support for masked atomic operations
IB/core: Add support for masked atomic operations
RDMA/cma: Randomize local port allocation
RDMA/nes: Make unnecessarily global functions static
RDMA/nes: Make nesadapter->phy_lock usage consistent
RDMA/cxgb4: Add driver for Chelsio T4 RNIC
IB/mthca: Use the dma state API instead of pci equivalents
RDMA/amso1100: Use the dma state API instead of pci equivalents
RDMA/cxgb3: Don't free skbs on NET_XMIT_* indications from LLD
RDMA/cxgb3: Use the dma state API instead of pci equivalents
IB: Explicitly rule out llseek to avoid BKL in default_llseek()
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (61 commits)
KEYS: Return more accurate error codes
LSM: Add __init to fixup function.
TOMOYO: Add pathname grouping support.
ima: remove ACPI dependency
TPM: ACPI/PNP dependency removal
security/selinux/ss: Use kstrdup
TOMOYO: Use stack memory for pending entry.
Revert "ima: remove ACPI dependency"
Revert "TPM: ACPI/PNP dependency removal"
KEYS: Do preallocation for __key_link()
TOMOYO: Use mutex_lock_interruptible.
KEYS: Better handling of errors from construct_alloc_key()
KEYS: keyring_serialise_link_sem is only needed for keyring->keyring links
TOMOYO: Use GFP_NOFS rather than GFP_KERNEL.
ima: remove ACPI dependency
TPM: ACPI/PNP dependency removal
selinux: generalize disabling of execmem for plt-in-heap archs
LSM Audit: rename LSM_AUDIT_NO_AUDIT to LSM_AUDIT_DATA_NONE
CRED: Holding a spinlock does not imply the holding of RCU read lock
SMACK: Don't #include Ext2 headers
...
The C99 specification states in section 6.11.5:
The placement of a storage-class specifier other than at the beginning
of the declaration specifiers in a declaration is an obsolescent
feature.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
