Commit graph

196684 commits

Author SHA1 Message Date
Anton Blanchard
0644079410 powerpc/kdump: CPUs assume the context of the oopsing CPU
We wrap the crash_shutdown_handles[] calls with longjmp/setjmp, so if any
of them fault we can recover. The problem is we add a hook to the debugger
fault handler hook which calls longjmp unconditionally.

This first part of kdump is run before we marshall the other CPUs, so there
is a very good chance some CPU on the box is going to page fault. And when
it does it hits the longjmp code and assumes the context of the oopsing CPU.
The machine gets very confused when it has 10 CPUs all with the same stack,
all thinking they have the same CPU id. I get even more confused trying
to debug it.

The patch below adds crash_shutdown_cpu and uses it to specify which cpu is
in the protected region. Since it can only be -1 or the oopsing CPU, we don't
need to use memory barriers since it is only valid on the local CPU - no other
CPU will ever see a value that matches it's local CPU id.

Eventually we should switch the order and marshall all CPUs before doing the
crash_shutdown_handles[] calls, but that is a bigger fix.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:31:10 +10:00
Maxim Uvarov
426b6cb478 powerpc/crashdump: Do not fail on NULL pointer dereferencing
Signed-off-by: Maxim Uvarov <muvarov@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:31:09 +10:00
Anton Blanchard
ce47c1c45b powerpc/eeh: Fix oops when probing in early boot
If we take an EEH error early enough, we oops:

Call Trace:
[c000000010483770] [c000000000013ee4] .show_stack+0xd8/0x218 (unreliable)
[c000000010483850] [c000000000658940] .dump_stack+0x28/0x3c
[c0000000104838d0] [c000000000057a68] .eeh_dn_check_failure+0x2b8/0x304
[c000000010483990] [c0000000000259c8] .rtas_read_config+0x120/0x168
[c000000010483a40] [c000000000025af4] .rtas_pci_read_config+0xe4/0x124
[c000000010483af0] [c00000000037af18] .pci_bus_read_config_word+0xac/0x104
[c000000010483bc0] [c0000000008fec98] .pcibios_allocate_resources+0x7c/0x220
[c000000010483c90] [c0000000008feed8] .pcibios_resource_survey+0x9c/0x418
[c000000010483d80] [c0000000008fea10] .pcibios_init+0xbc/0xf4
[c000000010483e20] [c000000000009844] .do_one_initcall+0x98/0x1d8
[c000000010483ed0] [c0000000008f0560] .kernel_init+0x228/0x2e8
[c000000010483f90] [c000000000031a08] .kernel_thread+0x54/0x70
EEH: Detected PCI bus error on device <null>
EEH: This PCI device has failed 1 times in the last hour:
EEH: location=U78A5.001.WIH8464-P1 driver= pci addr=0001:00:01.0
EEH: of node=/pci@800000020000209/usb@1
EEH: PCI device/vendor: 00351033
EEH: PCI cmd/status register: 12100146

Unable to handle kernel paging request for data at address 0x00000468
Oops: Kernel access of bad area, sig: 11 [#1]
....
NIP [c000000000057610] .rtas_set_slot_reset+0x38/0x10c
LR [c000000000058724] .eeh_reset_device+0x5c/0x124
Call Trace:
[c00000000bc6bd00] [c00000000005a0e0] .pcibios_remove_pci_devices+0x7c/0xb0 (unreliable)
[c00000000bc6bd90] [c000000000058724] .eeh_reset_device+0x5c/0x124
[c00000000bc6be40] [c0000000000589c0] .handle_eeh_events+0x1d4/0x39c
[c00000000bc6bf00] [c000000000059124] .eeh_event_handler+0xf0/0x188
[c00000000bc6bf90] [c000000000031a08] .kernel_thread+0x54/0x70

We called rtas_set_slot_reset while scanning the bus and before the pci_dn
to pcidev mapping has been created. Since we only need the pcidev to work
out the type of reset and that only gets set after the module for the
device loads, lets just do a hot reset if the pcidev is NULL.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Linas Vepstas <linasvepstas@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:31:09 +10:00
Sonny Rao
5b339bdf16 powerpc/pci: Check devices status property when scanning OF tree
We ran into an issue where it looks like we're not properly ignoring a
pci device with a non-good status property when we walk the device tree
and instanciate the Linux side PCI devices.

However, the EEH init code does look for the property and disables EEH
on these devices. This leaves us in an inconsistent where we are poking
at a supposedly bad piece of hardware and RTAS will block our config
cycles because EEH isn't enabled anyway.

Signed-of-by: Sonny Rao <sonnyrao@linux.vnet.ibm.com>

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:31:09 +10:00
Brian King
a1263c7144 powerpc/vio: Switch VIO Bus PM to use generic helpers
Switch to use the generic power management helpers.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:31:09 +10:00
Paul Mackerras
e62cee42e6 powerpc: Avoid bad relocations in iSeries code
Subrata Modak reported that building a CONFIG_RELOCATABLE kernel with
CONFIG_ISERIES enabled gives the following warnings:

WARNING: 4 bad relocations
c00000000007216e R_PPC64_ADDR16_HIGHEST  __ksymtab+0x00000000009dcec8
c000000000072172 R_PPC64_ADDR16_HIGHER  __ksymtab+0x00000000009dcec8
c00000000007217a R_PPC64_ADDR16_HI  __ksymtab+0x00000000009dcec8
c00000000007217e R_PPC64_ADDR16_LO  __ksymtab+0x00000000009dcec8

The reason is that decrementer_iSeries_masked is using
LOAD_REG_IMMEDIATE to get the address of a kernel symbol, which
creates relocations that aren't handled by the kernel relocator code.

Instead of reading the tb_ticks_per_jiffy variable, we can just set
the decrementer to its maximum value (0x7fffffff) and that will work
just as well.  In fact timer_interrupt sets the decrementer to that
value initially anyway, and we are sure to get into timer_interrupt
once interrupts are reenabled because we store 1 to the decrementer
interrupt flag in the lppaca (LPPACADECRINT(r12) here).

Reported-by: Subrata Modak <subrata@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:31:08 +10:00
Milton Miller
abb17f9c3a powerpc: Use common cpu_die (fixes SMP+SUSPEND build)
Configuring a powerpc 32 bit kernel for both SMP and SUSPEND turns on
CPU_HOTPLUG to enable disable_nonboot_cpus to be called by the common
suspend code.  Previously the definition of cpu_die for ppc32 was in
the powermac platform code, causing it to be undefined if that platform
as not selected.

arch/powerpc/kernel/built-in.o: In function 'cpu_idle':
arch/powerpc/kernel/idle.c:98: undefined reference to 'cpu_die'

Move the code from setup_64 to smp.c and rename the power mac
versions to their specific names.

Note that this does not setup the cpu_die pointers in either
smp_ops (request a given cpu die) or ppc_md (make this cpu die),
for other platforms but there are generic versions in smp.c.

Reported-by: Matt Sealey <matt@genesi-usa.com>
Reported-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:31:08 +10:00
Andreas Schwab
ca5d0674c3 powerpc: Fix string library functions
The powerpc strncmp implementation does not correctly handle a zero
length, despite the claim in 0119536cd3
(Add hand-coded assembly strcmp).

Additionally, all the length arguments are size_t, not int, so use
PPC_LCMPI and eq instead of cmpwi and le throughout.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:31:08 +10:00
Michael Ellerman
7358650e9e powerpc/rtasd: Don't start event scan if scan rate is zero
There appear to be Pegasos systems which have the rtas-event-scan
RTAS tokens, but on which the event scan always fails. They also
have an event-scan-rate property containing 0, which means call
event scan 0 times per minute.

So interpret a scan rate of 0 to mean don't scan at all. This fixes
the problem on the Pegasos machines and makes sense as well.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:29:39 +10:00
Alex Deucher
b486787ee4 drm/radeon/kms/pm/r600: select the mid clock mode for single head low profile
This saves some more power at the expense of performance.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-05-21 15:47:40 +10:00
Dave Airlie
df696a6fe8 Merge remote branch 'nouveau/for-airlied' into drm-next
* nouveau/for-airlied:
  drm/nouveau: fix i2c-related init table handlers
  drm/nouveau: support init table i2c device identifier 0x81
  drm/nouveau: ensure we've parsed i2c table entry for INIT_*I2C* handlers
  drm/nouveau: display error message for any failed init table opcode
  drm/nouveau: fix init table handlers to return proper error codes
  drm/nv50: support fractional feedback divider on newer chips
  drm/nv50: fix monitor detection on certain chipsets
  drm/nv50: store full dcb i2c entry from vbios
  drm/nv50: fix suspend/resume with DP outputs
  drm/nv50: output calculated crtc pll when debugging on
  drm/nouveau: dump pll limits entries when debugging is on
  drm/nouveau: bios parser fixes for eDP boards
  drm/nouveau: fix a nouveau_bo dereference after it's been destroyed
  drm/nv40: remove some completed ctxprog TODOs
  drm/nv04: Implement missing nv04 PGRAPH methods in software.
  drm/nouveau: Use 0x5f instead of 0x9f as imageblit on original NV10.
2010-05-21 15:44:32 +10:00
Dave Airlie
5d9b7e2d2d drm/radeon: fix power supply kconfig interaction.
radeon needs power supply to get correct PM info so select it at the radeon
level not at the kms option.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-05-21 15:41:20 +10:00
Jerome Glisse
e865275335 drm/radeon/kms: record object that have been list reserved
list reservation was too optimistic about ttm object reservation
and could think that an object reserved by some other process
as reserved by the list reservation which was false. Thus when
unreserving the list it might unreserve object that it didn't
reserved in the list. Sorry if it's hard to follow but this
kind of things are just causing headheck.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-05-21 15:07:24 +10:00
Michel Dänzer
365048ff7f drm/radeon: AGP memory is only I/O if the aperture can be mapped by the CPU.
Fixes AGP initialization failure with Apple UniNorth bridges due to trying to
ioremap() normal RAM.

Signed-off-by: Michel Dänzer <daenzer@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-05-21 15:06:45 +10:00
Alex Deucher
45737447ed drm/radeon/kms: don't default display priority to high on rs4xx
Seems to cause issues with the sound hardware.  Fixes kernel
bug 15982:
https://bugzilla.kernel.org/show_bug.cgi?id=15982

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-05-21 15:06:06 +10:00
Alex Deucher
c43ae476a5 drm/edid: fix typo in 1600x1200@75 mode
Spotted by Scott Bertilson.
Fixes fdo bug 28146.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Reviewed-by: Mark Marshall <mark.marshall@csr.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2010-05-21 15:05:15 +10:00
Linus Torvalds
7a9b149212 Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6: (229 commits)
  USB: remove unused usb_buffer_alloc and usb_buffer_free macros
  usb: musb: update gfp/slab.h includes
  USB: ftdi_sio: fix legacy SIO-device header
  USB: kl5usb105: reimplement using generic framework
  USB: kl5usb105: minor clean ups
  USB: kl5usb105: fix memory leak
  USB: io_ti: use kfifo to implement write buffering
  USB: io_ti: remove unsused private counter
  USB: ti_usb: use kfifo to implement write buffering
  USB: ir-usb: fix incorrect write-buffer length
  USB: aircable: fix incorrect write-buffer length
  USB: safe_serial: straighten out read processing
  USB: safe_serial: reimplement read using generic framework
  USB: safe_serial: reimplement write using generic framework
  usb-storage: always print quirks
  USB: usb-storage: trivial debug improvements
  USB: oti6858: use port write fifo
  USB: oti6858: use kfifo to implement write buffering
  USB: cypress_m8: use kfifo to implement write buffering
  USB: cypress_m8: remove unused drain define
  ...

Fix up conflicts (due to usb_buffer_alloc/free renaming) in
	drivers/input/tablet/acecad.c
	drivers/input/tablet/kbtab.c
	drivers/input/tablet/wacom_sys.c
	drivers/media/video/gspca/gspca.c
	sound/usb/usbaudio.c
2010-05-20 21:26:12 -07:00
Stephen Rothwell
3d62e3fdce sound: fixup for usb_buffer_alloc/free rename
This is needed before the USB merge.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-20 21:15:18 -07:00
Linus Torvalds
f8965467f3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1674 commits)
  qlcnic: adding co maintainer
  ixgbe: add support for active DA cables
  ixgbe: dcb, do not tag tc_prio_control frames
  ixgbe: fix ixgbe_tx_is_paused logic
  ixgbe: always enable vlan strip/insert when DCB is enabled
  ixgbe: remove some redundant code in setting FCoE FIP filter
  ixgbe: fix wrong offset to fc_frame_header in ixgbe_fcoe_ddp
  ixgbe: fix header len when unsplit packet overflows to data buffer
  ipv6: Never schedule DAD timer on dead address
  ipv6: Use POSTDAD state
  ipv6: Use state_lock to protect ifa state
  ipv6: Replace inet6_ifaddr->dead with state
  cxgb4: notify upper drivers if the device is already up when they load
  cxgb4: keep interrupts available when the ports are brought down
  cxgb4: fix initial addition of MAC address
  cnic: Return SPQ credit to bnx2x after ring setup and shutdown.
  cnic: Convert cnic_local_flags to atomic ops.
  can: Fix SJA1000 command register writes on SMP systems
  bridge: fix build for CONFIG_SYSFS disabled
  ARCNET: Limit com20020 PCI ID matches for SOHARD cards
  ...

Fix up various conflicts with pcmcia tree drivers/net/
{pcmcia/3c589_cs.c, wireless/orinoco/orinoco_cs.c and
wireless/orinoco/spectrum_cs.c} and feature removal
(Documentation/feature-removal-schedule.txt).

Also fix a non-content conflict due to pm_qos_requirement getting
renamed in the PM tree (now pm_qos_request) in net/mac80211/scan.c
2010-05-20 21:04:44 -07:00
Jason Wessel
4fe1da4ebc echi-dbgp: Add kernel debugger support for the usb debug port
This patch adds the capability to use the usb debug port with the
kernel debugger.  It is also still possible to use this functionality
with or without the earlyprintk=dbgpX.  It is possible to use the
kgdbwait boot argument to debug very early in the kernel start up code.

There are two ways to use this driver extension with a kernel boot argument.

1) kgdbdbgp=#   -- Where # is the number of the usb debug controller

   You must use sysrq-g to break into the kernel debugger on another
   connection type other than the dbgp.

2) kgdbdbgp=#debugControlNum#,#Seconds#

   In this mode, the usb debug port is polled every #Seconds# for
   character input.  It is possible to use gdb or press control-c to
   break into the kernel debugger.

From the implementation perspective there are 3 high level changes.

1) Allow variable retries for the the hardware via dbgp_bulk_read().

   The amount of retries for the dbgp_bulk_read() needed to be
   variable instead of fixed.  We do not want to poll at all when the
   kernel is operating in interrupt driven mode.  The polling only
   occurs if the kernel was booted when specifying some number of
   seconds via the kgdbdbgp boot argument (IE kgdbdbgp=0,1).  In this
   case the loop count is reduced to 1 so as introduce the smallest
   amount of latency as possible.

2) Save the bulk IN endpoint address for use by the kgdb code.

3) The addition of the kgdb interface code.

   This consisted of adding in a character read function for the dbgp
   as well as a polling thread to allow the dbgp to interrupt the
   kernel execution.  The rest is the typical kgdb I/O api.

CC: Eric Biederman <ebiederm@xmission.com>
CC: Yinghai Lu <yhlu.kernel@gmail.com>
CC: linux-usb@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 21:04:31 -05:00
Jason Wessel
61eaf539b9 earlyprintk,vga,kdb: Fix \b and \r for earlyprintk=vga with kdb
Allow kdb to work properly with with earlyprintk=vga by interpreting
the backspace and carriage return output characters.  These
interpretation of these characters is used for simple line editing
provided in the kdb shell.

CC: Thomas Gleixner <tglx@linutronix.de>
CC: Ingo Molnar <mingo@redhat.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: x86@kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-05-20 21:04:31 -05:00
Jason Wessel
9731191f75 kgdboc: Add ekgdboc for early use of the kernel debugger
The ekgdboc= differs from kgdboc= in that you can begin debuggin as
soon as the exceptions are setup and the kgdb I/O driver is available,
instead of waiting until the tty subsystem is available.

CC: kgdb-bugreport@lists.sourceforge.net
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-05-20 21:04:30 -05:00
Jason Wessel
0bb9fef913 x86,early dr regs,kgdb: Allow kernel debugger early dr register access
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>
2010-05-20 21:04:30 -05:00
Jason Wessel
031acd8c42 x86,kgdb: Implement early hardware breakpoint debugging
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>
2010-05-20 21:04:30 -05:00
Jason Wessel
0b4b3827db x86, kgdb, init: Add early and late debug states
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>
2010-05-20 21:04:29 -05:00
Jan Kiszka
29c843912a x86, kgdb: early trap init for early debug
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>
2010-05-20 21:04:29 -05:00
Jason Wessel
4402c153cb kdb,debug_core: Allow the debug core to receive a panic notification
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>
2010-05-20 21:04:28 -05:00
Jason Wessel
5b778dadcd MAINTAINERS: update kgdb, kdb, and debug_core info
Update the maintained files sections.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-05-20 21:04:28 -05:00
Jason Wessel
6d90634076 debug_core,kdb: Allow the debug core to process a recursive debug entry
This allows kdb to debug a crash with in the kms code with a
single level recursive re-entry.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-05-20 21:04:27 -05:00
Jason Wessel
d37d39ae3b printk,kdb: capture printk() when in kdb shell
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>
2010-05-20 21:04:27 -05:00
Jason Wessel
efe2f29e32 kgdboc,kdb: Allow kdb to work on a non open console port
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>
2010-05-20 21:04:26 -05:00
Jason Wessel
1cee5e35f1 kgdb: Add the ability to schedule a breakpoint via a tasklet
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>
2010-05-20 21:04:26 -05:00
Jason Wessel
5dd11d5d47 mips,kgdb: kdb low level trap catch and stack trace
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>
2010-05-20 21:04:26 -05:00
Jason Wessel
ba797b2813 powerpc,kgdb: Introduce low level trap catching
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>
2010-05-20 21:04:25 -05:00
Jason Wessel
f503b5ae53 x86,kgdb: Add low level debug hook
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>
2010-05-20 21:04:25 -05:00
Jason Wessel
98ec1878ca kgdb: remove post_primary_code references
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>
2010-05-20 21:04:25 -05:00
Jason Wessel
84c08fd61e kgdb,docs: Update the kgdb docs to include kdb
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>
2010-05-20 21:04:24 -05:00
Jason Wessel
ada64e4c98 kgdboc,keyboard: Keyboard driver for kdb with kgdb
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>
2010-05-20 21:04:24 -05:00
Jason Wessel
a0de055cf6 kgdb: gdb "monitor" -> kdb passthrough
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>
2010-05-20 21:04:24 -05:00
Jason Wessel
6d45a1aed3 sparc,sunzilog: Add console polling support for sunzilog serial driver
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>
2010-05-20 21:04:23 -05:00
Jason Wessel
3f255eb37e sh,sh-sci: Use NO_POLL_CHAR in the SCIF polled console code
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>
2010-05-20 21:04:23 -05:00
Jason Wessel
f5316b4aea kgdb,8250,pl011: Return immediately from console poll
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>
2010-05-20 21:04:22 -05:00
Jason Wessel
dcc7871128 kgdb: core changes to support kdb
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>
2010-05-20 21:04:21 -05:00
Jason Wessel
67fc4e0cb9 kdb: core for kgdb back end (2 of 2)
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>
2010-05-20 21:04:21 -05:00
Jason Wessel
5d5314d679 kdb: core for kgdb back end (1 of 2)
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>
2010-05-20 21:04:20 -05:00
Jason Wessel
e8861129d3 kgdb,blackfin: Add in kgdb_arch_set_pc for blackfin
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>
2010-05-20 21:04:20 -05:00
Jason Wessel
489022cc86 kgdb,sh: update superh kgdb exception handling
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>
2010-05-20 21:04:20 -05:00
Jason Wessel
c75fbb05b5 kgdb,sparc: Add in kgdb_arch_set_pc for sparc
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>
2010-05-20 21:04:19 -05:00
Jason Wessel
4063eb5fa4 MAINTAINERS: update kgdb, and debug_core info
Update the kgdb section.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-05-20 21:04:19 -05:00
Jason Wessel
53197fc495 Separate the gdbstub from the debug core
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>
2010-05-20 21:04:19 -05:00