Commit Graph

186 Commits

Author SHA1 Message Date
Daniel Thompson
5454388113 kdb: Remove stack dump when entering kgdb due to NMI
Issuing a stack dump feels ergonomically wrong when entering due to NMI.

Entering due to NMI is normally a reaction to a user request, either the
NMI button on a server or a "magic knock" on a UART. Therefore the
backtrace behaviour on entry due to NMI should be like SysRq-g (no stack
dump) rather than like oops.

Note also that the stack dump does not offer any information that
cannot be trivial retrieved using the 'bt' command.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2015-02-19 12:39:02 -06:00
Daniel Thompson
f7d4ca8bbf kdb: Avoid printing KERN_ levels to consoles
Currently when kdb traps printk messages then the raw log level prefix
(consisting of '\001' followed by a numeral) does not get stripped off
before the message is issued to the various I/O handlers supported by
kdb. This causes annoying visual noise as well as causing problems
grepping for ^. It is also a change of behaviour compared to normal usage
of printk() usage. For example <SysRq>-h ends up with different output to
that of kdb's "sr h".

This patch addresses the problem by stripping log levels from messages
before they are issued to the I/O handlers. printk() which can also
act as an i/o handler in some cases is special cased; if the caller
provided a log level then the prefix will be preserved when sent to
printk().

The addition of non-printable characters to the output of kdb commands is a
regression, albeit and extremely elderly one, introduced by commit
04d2c8c83d ("printk: convert the format for KERN_<LEVEL> to a 2 byte
pattern"). Note also that this patch does *not* restore the original
behaviour from v3.5. Instead it makes printk() from within a kdb command
display the message without any prefix (i.e. like printk() normally does).

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Joe Perches <joe@perches.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2015-02-19 12:39:02 -06:00
Jason Wessel
df0036d117 kdb: Fix off by one error in kdb_cpu()
There was a follow on replacement patch against the prior
"kgdb: Timeout if secondary CPUs ignore the roundup".

See: https://lkml.org/lkml/2015/1/7/442

This patch is the delta vs the patch that was committed upstream:
  * Fix an off-by-one error in kdb_cpu().
  * Replace NR_CPUS with CONFIG_NR_CPUS to tell checkpatch that we
    really want a static limit.
  * Removed the "KGDB: " prefix from the pr_crit() in debug_core.c
    (kgdb-next contains a patch which introduced pr_fmt() to this file
    to the tag will now be applied automatically).

Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2015-02-19 12:39:02 -06:00
Jay Lan
1467559232 kdb: fix incorrect counts in KDB summary command output
The output of KDB 'summary' command should report MemTotal, MemFree
and Buffers output in kB. Current codes report in unit of pages.

A define of K(x) as
is defined in the code, but not used.

This patch would apply the define to convert the values to kB.
Please include me on Cc on replies. I do not subscribe to linux-kernel.

Signed-off-by: Jay Lan <jlan@sgi.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2015-02-19 12:39:02 -06:00
Linus Torvalds
193934123c Surprising number of fixes this merge window :(
First two are minor fallout from the param rework which went in this merge
 window.
 
 Next three are a series which fixes a longstanding (but never previously
 reported and unlikely , so no CC stable) race between kallsyms and freeing
 the init section.
 
 Finally, a minor cleanup as our module refcount will now be -1 during
 unload.
 
 Thanks,
 Rusty.
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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull module and param fixes from Rusty Russell:
 "Surprising number of fixes this merge window :(

  The first two are minor fallout from the param rework which went in
  this merge window.

  The next three are a series which fixes a longstanding (but never
  previously reported and unlikely , so no CC stable) race between
  kallsyms and freeing the init section.

  Finally, a minor cleanup as our module refcount will now be -1 during
  unload"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
  module: make module_refcount() a signed integer.
  module: fix race in kallsyms resolution during module load success.
  module: remove mod arg from module_free, rename module_memfree().
  module_arch_freeing_init(): new hook for archs before module->module_init freed.
  param: fix uninitialized read with CONFIG_DEBUG_LOCK_ALLOC
  param: initialize store function to NULL if not available.
2015-01-23 06:40:36 +12:00
Rusty Russell
d5db139ab3 module: make module_refcount() a signed integer.
James Bottomley points out that it will be -1 during unload.  It's
only used for diagnostics, so let's not hide that as it could be a
clue as to what's gone wrong.

Cc: Jason Wessel <jason.wessel@windriver.com>
Acked-and-documention-added-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: Masami Hiramatsu <maasami.hiramatsu.pt@hitachi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-01-22 11:15:54 +10:30
Daniel Thompson
a1465d2f39 kgdb: timeout if secondary CPUs ignore the roundup
Currently if an active CPU fails to respond to a roundup request the CPU
that requested the roundup will become stuck.  This needlessly reduces the
robustness of the debugger.

This patch introduces a timeout allowing the system state to be examined
even when the system contains unresponsive processors.  It also modifies
kdb's cpu command to make it censor attempts to switch to unresponsive
processors and to report their state as (D)ead.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2014-11-11 09:31:53 -06:00
Daniel Thompson
b8017177cd kdb: Allow access to sensitive commands to be restricted by default
Currently kiosk mode must be explicitly requested by the bootloader or
userspace. It is convenient to be able to change the default value in a
similar manner to CONFIG_MAGIC_SYSRQ_DEFAULT_MASK.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2014-11-11 09:31:52 -06:00
Anton Vorontsov
420c2b1b0d kdb: Add enable mask for groups of commands
Currently all kdb commands are enabled whenever kdb is deployed. This
makes it difficult to deploy kdb to help debug certain types of
systems.

Android phones provide one example; the FIQ debugger found on some
Android devices has a deliberately weak set of commands to allow the
debugger to enabled very late in the production cycle.

Certain kiosk environments offer another interesting case where an
engineer might wish to probe the system state using passive inspection
commands without providing sufficient power for a passer by to root it.

Without any restrictions, obtaining the root rights via KDB is a matter of
a few commands, and works everywhere. For example, log in as a normal
user:

cbou:~$ id
uid=1001(cbou) gid=1001(cbou) groups=1001(cbou)

Now enter KDB (for example via sysrq):

Entering kdb (current=0xffff8800065bc740, pid 920) due to Keyboard Entry
kdb> ps
23 sleeping system daemon (state M) processes suppressed,
use 'ps A' to see all.
Task Addr               Pid   Parent [*] cpu State Thread             Command
0xffff8800065bc740      920      919  1    0   R  0xffff8800065bca20 *bash

0xffff880007078000        1        0  0    0   S  0xffff8800070782e0  init
[...snip...]
0xffff8800065be3c0      918        1  0    0   S  0xffff8800065be6a0  getty
0xffff8800065b9c80      919        1  0    0   S  0xffff8800065b9f60  login
0xffff8800065bc740      920      919  1    0   R  0xffff8800065bca20 *bash

All we need is the offset of cred pointers. We can look up the offset in
the distro's kernel source, but it is unnecessary. We can just start
dumping init's task_struct, until we see the process name:

kdb> md 0xffff880007078000
0xffff880007078000 0000000000000001 ffff88000703c000   ................
0xffff880007078010 0040210000000002 0000000000000000   .....!@.........
[...snip...]
0xffff8800070782b0 ffff8800073e0580 ffff8800073e0580   ..>.......>.....
0xffff8800070782c0 0000000074696e69 0000000000000000   init............

^ Here, 'init'. Creds are just above it, so the offset is 0x02b0.

Now we set up init's creds for our non-privileged shell:

kdb> mm 0xffff8800065bc740+0x02b0 0xffff8800073e0580
0xffff8800065bc9f0 = 0xffff8800073e0580
kdb> mm 0xffff8800065bc740+0x02b8 0xffff8800073e0580
0xffff8800065bc9f8 = 0xffff8800073e0580

And thus gaining the root:

kdb> go
cbou:~$ id
uid=0(root) gid=0(root) groups=0(root)
cbou:~$ bash
root:~#

p.s. No distro enables kdb by default (although, with a nice KDB-over-KMS
feature availability, I would expect at least some would enable it), so
it's not actually some kind of a major issue.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2014-11-11 09:31:52 -06:00
Daniel Thompson
9452e977ac kdb: Categorize kdb commands (similar to SysRq categorization)
This patch introduces several new flags to collect kdb commands into
groups (later allowing them to be optionally disabled).

This follows similar prior art to enable/disable magic sysrq
commands.

The commands have been categorized as follows:

Always on:  go (w/o args), env, set, help, ?, cpu (w/o args), sr,
            dmesg, disable_nmi, defcmd, summary, grephelp
Mem read:   md, mdr, mdp, mds, ef, bt (with args), per_cpu
Mem write:  mm
Reg read:   rd
Reg write:  go (with args), rm
Inspect:    bt (w/o args), btp, bta, btc, btt, ps, pid, lsmod
Flow ctrl:  bp, bl, bph, bc, be, bd, ss
Signal:     kill
Reboot:     reboot
All:        cpu, kgdb, (and all of the above), nmi_console

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2014-11-11 09:31:52 -06:00
Anton Vorontsov
e8ab24d9b0 kdb: Remove KDB_REPEAT_NONE flag
Since we now treat KDB_REPEAT_* as flags, there is no need to
pass KDB_REPEAT_NONE. It's just the default behaviour when no
flags are specified.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2014-11-11 09:31:52 -06:00
Anton Vorontsov
04bb171e7a kdb: Use KDB_REPEAT_* values as flags
The actual values of KDB_REPEAT_* enum values and overall logic stayed
the same, but we now treat the values as flags.

This makes it possible to add other flags and combine them, plus makes
the code a lot simpler and shorter. But functionality-wise, there should
be no changes.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2014-11-11 09:31:51 -06:00
Anton Vorontsov
42c884c10b kdb: Rename kdb_register_repeat() to kdb_register_flags()
We're about to add more options for commands behaviour, so let's give
a more generic name to the low-level kdb command registration function.

There are just various renames, no functional changes.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2014-11-11 09:31:51 -06:00
Anton Vorontsov
15a42a9bc9 kdb: Rename kdb_repeat_t to kdb_cmdflags_t, cmd_repeat to cmd_flags
We're about to add more options for command behaviour, so let's expand
the meaning of kdb_repeat_t.

So far we just do various renames, there should be no functional changes.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2014-11-11 09:31:51 -06:00
Anton Vorontsov
a2e5d188aa kdb: Remove currently unused kdbtab_t->cmd_flags
The struct member is never used in the code, so we can remove it.

We will introduce real flags soon by renaming cmd_repeat to cmd_flags.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2014-11-11 09:31:51 -06:00
Rasmus Villemoes
f9f2bac27c kdb: replace strnicmp with strncasecmp
The kernel used to contain two functions for length-delimited,
case-insensitive string comparison, strnicmp with correct semantics and
a slightly buggy strncasecmp.  The latter is the POSIX name, so strnicmp
was renamed to strncasecmp, and strnicmp made into a wrapper for the new
strncasecmp to avoid breaking existing users.

To allow the compat wrapper strnicmp to be removed at some point in the
future, and to avoid the extra indirection cost, do
s/strnicmp/strncasecmp/g.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-10-14 02:18:25 +02:00
Thomas Gleixner
a9821c741c kdb: Use ktime_get_ts()
do_posix_clock_monotonic_gettime() is a leftover from the initial
posix timer implementation which maps to ktime_get_ts().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Link: http://lkml.kernel.org/r/20140611234607.261629142@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-06-12 16:18:45 +02:00
Borislav Petkov
a8fe19ebfb kernel/printk: use symbolic defines for console loglevels
... instead of naked numbers.

Stuff in sysrq.c used to set it to 8 which is supposed to mean above
default level so set it to DEBUG instead as we're terminating/killing all
tasks and we want to be verbose there.

Also, correct the check in x86_64_start_kernel which should be >= as
we're clearly issuing the string there for all debug levels, not only
the magical 10.

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Joe Perches <joe@perches.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:54:17 -07:00
Mike Travis
8daaa5f826 kdb: Add support for external NMI handler to call KGDB/KDB
This patch adds a kgdb_nmicallin() interface that can be used by
external NMI handlers to call the KGDB/KDB handler.  The primary
need for this is for those types of NMI interrupts where all the
CPUs have already received the NMI signal.  Therefore no
send_IPI(NMI) is required, and in fact it will cause a 2nd
unhandled NMI to occur. This generates the "Dazed and Confuzed"
messages.

Since all the CPUs are getting the NMI at roughly the same time,
it's not guaranteed that the first CPU that hits the NMI handler
will manage to enter KGDB and set the dbg_master_lock before the
slaves start entering. The new argument "send_ready" was added
for KGDB to signal the NMI handler to release the slave CPUs for
entry into KGDB.

Signed-off-by: Mike Travis <travis@sgi.com>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Hedi Berriche <hedi@sgi.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20131002151417.928886849@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-10-03 18:47:54 +02:00
Vincent
36dfea42cc kdb: Remove unhandled ssb command
The 'ssb' command can only be handled when we have a disassembler, to check for
branches, so remove the 'ssb' command for now.

Signed-off-by: Vincent Stehlé <vincent.stehle@laposte.net>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2013-03-02 08:52:20 -06:00
Jason Wessel
a37372f6c3 kdb: Prevent kernel oops with kdb_defcmd
The kdb_defcmd can only be used to display the available command aliases
while using the kernel debug shell.  If you try to define a new macro
while the kernel debugger is active it will oops.  The debug shell
macros must use pre-allocated memory set aside at the time kdb_init()
is run, and the kdb_defcmd is restricted to only working at the time
that the kdb_init sequence is being run, which only occurs if you
actually activate the kernel debugger.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2013-03-02 08:52:19 -06:00
Jason Wessel
1b2caa2dcb kdb: Remove the ll command
Recently some code inspection was done after fixing a problem with
kmalloc used while in the kernel debugger context (which is not
legal), and it turned up the fact that kdb ll command will oops the
kernel.

Given that there have been zero bug reports on the command combined
with the fact it will oops the kernel it is clearly not being used.
Instead of fixing it, it will be removed.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2013-03-02 08:52:19 -06:00
Jason Wessel
074604af21 kdb_main: fix help print
The help command was chopping all the usage instructions such that
they were not readable.

Example:

bta             [D|R|S|T|C|Z|E|U|I| Backtrace all processes matching state flag
per_cpu         <sym> [<bytes>] [<c Display per_cpu variables

Where as it should look like:

bta             [D|R|S|T|C|Z|E|U|I|M|A]
                                    Backtrace all processes matching state flag
per_cpu         <sym> [<bytes>] [<cpu>]
                                    Display per_cpu variables

All that is needed is to check the how long the cmd_usage is and jump
to the next line when appropriate.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2013-03-02 08:52:18 -06:00
Jason Wessel
4eb7a66d94 kdb: Fix overlap in buffers with strcpy
Maxime reported that strcpy(s->usage, s->usage+1) has no definitive
guarantee that it will work on all archs the same way when you have
overlapping memory.  The fix is simple for the kdb code because we
still have the original string memory in the function scope, so we
just have to use that as the argument instead.

Reported-by: Maxime Villard <rustyBSD@gmx.fr>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2013-03-02 08:52:18 -06:00
Matt Klein
00370b8f8d kdb: Setup basic kdb state before invoking commands via kgdb
Although invasive kdb commands are not supported via kgdb, some useful
non-invasive commands like bt* require basic kdb state to be setup before
calling into the kdb code. Factor out some of this code and call it before
and after executing kdb commands via kgdb.

Signed-off-by: Matt Klein <mklein@twitter.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2013-03-02 08:52:17 -06:00
Sasha Levin
5f784f798c kdb: use ARRAY_SIZE where possible
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2013-03-02 08:52:17 -06:00
John Blackwood
f7c82d5a3c kdb: A fix for kdb command table expansion
When locally adding in some additional kdb commands, I stumbled
across an issue with the dynamic expansion of the kdb command table.
When the number of kdb commands exceeds the size of the statically
allocated kdb_base_commands[] array, additional space is allocated in
the kdb_register_repeat() routine.

The unused portion of the newly allocated array was not being initialized
to zero properly and this would result in segfaults when help '?' was
executed or when a search for a non-existing command would traverse the
command table beyond the end of valid command entries and then attempt
to use the non-zeroed area as actual command entries.

Signed-off-by: John Blackwood <john.blackwood@ccur.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2013-03-02 08:52:16 -06:00
Rusty Russell
0d21b0e347 module: add new state MODULE_STATE_UNFORMED.
You should never look at such a module, so it's excised from all paths
which traverse the modules list.

We add the state at the end, to avoid gratuitous ABI break (ksplice).

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-01-12 13:27:05 +10:30
Linus Torvalds
6c536a17fa KGDB/KDB fixes and cleanups
Cleanups
    Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c
    Add module event hooks for simplified debugging with gdb
  Fixes
    Fix kdb to stop paging with 'q' on bta and dmesg
    Fix for data that scrolls off the vga console due to line wrapping
      when using the kdb pager
  New
    The debug core registers for kernel module events which allows a
      kernel aware gdb to automatically load symbols and break on entry
      to a kernel module
    Allow kgdboc=kdb to setup kdb on the vga console
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Merge tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb

Pull KGDB/KDB fixes and cleanups from Jason Wessel:
 "Cleanups
   - Clean up compile warnings in kgdboc.c and x86/kernel/kgdb.c
   - Add module event hooks for simplified debugging with gdb
 Fixes
   - Fix kdb to stop paging with 'q' on bta and dmesg
   - Fix for data that scrolls off the vga console due to line wrapping
     when using the kdb pager
 New
   - The debug core registers for kernel module events which allows a
     kernel aware gdb to automatically load symbols and break on entry
     to a kernel module
   - Allow kgdboc=kdb to setup kdb on the vga console"

* tag 'for_linus-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  tty/console: fix warnings in drivers/tty/serial/kgdboc.c
  kdb,vt_console: Fix missed data due to pager overruns
  kdb: Fix dmesg/bta scroll to quit with 'q'
  kgdboc: Accept either kbd or kdb to activate the vga + keyboard kdb shell
  kgdb,x86: fix warning about unused variable
  mips,kgdb: fix recursive page fault with CONFIG_KPROBES
  kgdb: Add module event hooks
2012-10-13 11:16:58 +09:00
Jason Wessel
17b572e820 kdb,vt_console: Fix missed data due to pager overruns
It is possible to miss data when using the kdb pager.  The kdb pager
does not pay attention to the maximum column constraint of the screen
or serial terminal.  This result is not incrementing the shown lines
correctly and the pager will print more lines that fit on the screen.
Obviously that is less than useful when using a VGA console where you
cannot scroll back.

The pager will now look at the kdb_buffer string to see how many
characters are printed.  It might not be perfect considering you can
output ASCII that might move the cursor position, but it is a
substantially better approximation for viewing dmesg and trace logs.

This also means that the vt screen needs to set the kdb COLUMNS
variable.

Cc: <stable@vger.kernel.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2012-10-12 06:37:35 -05:00
Jason Wessel
d1871b38fc kdb: Fix dmesg/bta scroll to quit with 'q'
If you press 'q' the pager should exit instead of printing everything
from dmesg which can really bog down a 9600 baud serial link.

The same is true for the bta command.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2012-10-12 06:37:35 -05:00
Anton Vorontsov
ad394f66fa kdb: Implement disable_nmi command
This command disables NMI-entry. If NMI source has been previously shared
with a serial console ("debug port"), this effectively releases the port
from KDB exclusive use, and makes the console available for normal use.

Of course, NMI can be reenabled, enable_nmi modparam is used for that:

	echo 1 > /sys/module/kdb/parameters/enable_nmi

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-09-26 13:42:25 -07:00
Anton Vorontsov
b10d22d6e8 kernel/debug: Make use of KGDB_REASON_NMI
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>
2012-07-31 08:16:43 -05:00
Jason Wessel
07cd27bbd4 kdb: Remove cpu from the more prompt
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>
2012-07-31 08:16:43 -05:00
Jason Wessel
0f26d0e0a7 kdb: Remove unused KDB_FLAG_ONLY_DO_DUMP
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>
2012-07-31 08:16:42 -05:00
Anton Vorontsov
c064da4714 kdb: Switch to nolock variants of kmsg_dump functions
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>
2012-07-21 10:34:00 -07:00
Anton Vorontsov
1b499d05ee printk: Remove kdb_syslog_data
The function is no longer needed, so remove it.

Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-07-21 10:34:00 -07:00
Anton Vorontsov
bc792e612e kdb: Revive dmesg command
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>
2012-07-21 10:34:00 -07:00
Linus Torvalds
6c216ec636 KGDB/KDB regression fixes
3.4: Fix an an Smatch warning that appeared in the 3.4 merge window
    3.0: Fix kgdb test suite with SMP for all archs without HW single stepping
 2.6.36: Fix kgdb sw breakpoints with CONFIG_DEBUG_RODATA=y limitations on x86
 2.6.26: Fix oops on kgdb test suite with CONFIG_DEBUG_RODATA
         Fix kgdb test suite with SMP for all archs with HW single stepping
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Merge tag 'for_linus-3.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb

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
2012-04-04 17:26:08 -07:00
Jason Wessel
78724b8ef8 kdb: Fix smatch warning on dbg_io_ops->is_console
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>
2012-03-29 17:41:23 -05:00
Linus Torvalds
0195c00244 Disintegrate and delete asm/system.h
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Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

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
  ...
2012-03-28 15:58:21 -07:00
David Howells
9ffc93f203 Remove all #inclusions of asm/system.h
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>
2012-03-28 18:30:03 +01:00
Linus Torvalds
a20ae85aba 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
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Merge tag 'for_linus-3.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb

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
2012-03-23 09:29:44 -07:00
Jason Wessel
1ba0c1720e kdb: Add message about CONFIG_DEBUG_RODATA on failure to install breakpoint
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>
2012-03-22 15:07:16 -05:00
Tim Bird
b8adde8dde kdb: Avoid using dbg_io_ops until it is initialized
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>
2012-03-22 15:07:16 -05:00
Andrei Warkentin
8f30d41176 KDB: Fix usability issues relating to the 'enter' key.
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>
2012-03-22 15:07:15 -05:00
Cong Wang
d762a50b5b kdb: remove the second argument of k[un]map_atomic()
Signed-off-by: Cong Wang <amwang@redhat.com>
2012-03-20 21:48:26 +08:00
Eric Dumazet
bd77c04772 module: struct module_ref should contains long fields
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>
2012-01-13 09:32:14 +10:30
Paul E. McKenney
7fc20c5cbd kdb: Make KDB use the new is_idle_task() API
Change from direct comparison of ->pid with zero to is_idle_task().

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2011-12-11 10:31:52 -08:00
Paul Gortmaker
6e5fdeedca kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructure
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>
2011-10-31 19:30:05 -04:00
Jason Wessel
37f86b469d kdb,kgdb: Allow arbitrary kgdb magic knock sequences
The first packet that gdb sends when the kernel is in kdb mode seems
to change with every release of gdb.  Instead of continuing to add
many different gdb packets, change kdb to automatically look for any
thing that looks like a gdb packet.

Example 1 cold start test:
echo g > /proc/sysrq-trigger
$D#44+

Example 2 cold start test:
echo g > /proc/sysrq-trigger
$3#33

The second one should re-enter kdb's shell right away and is purely a
test.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2011-08-01 13:23:59 -05:00
Jason Wessel
d613d828e8 kdb: Remove all references to DOING_KGDB2
The DOING_KGDB2 was originally a state variable for one of the two
ways to automatically transition from kdb to kgdb.  Purge all these
variables and just use one single state for the transition.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2011-08-01 13:23:59 -05:00
Jason Wessel
f679c4985b kdb,kgdb: Implement switch and pass buffer from kdb -> gdb
When switching from kdb mode to kgdb mode packets were getting lost
depending on the size of the fifo queue of the serial chip.  When gdb
initially connects if it is in kdb mode it should entirely send any
character buffer over to the gdbstub when switching connections.

Previously kdb was zero'ing out the character buffer and this could
lead to gdb failing to connect at all, or a lengthy pause could occur
on the initial connect.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2011-08-01 13:23:59 -05:00
Jason Wessel
3bdb65ec95 kdb: cleanup unused variables missed in the original kdb merge
The BTARGS and BTSYMARG variables do not have any function in the
mainline version of kdb.

Reported-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2011-08-01 13:23:58 -05:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Namhyung Kim
0d3db28dae kdb: add usage string of 'per_cpu' command
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2011-03-25 16:37:31 -05:00
Jovi Zhang
27029c339b kdb: code cleanup to use macro instead of value
It's better to use macro KDB_BASE_CMD_MAX instead of 50

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2011-03-25 16:37:30 -05:00
Jiri Kosina
4b7bd36470 Merge branch 'master' into for-next
Conflicts:
	MAINTAINERS
	arch/arm/mach-omap2/pm24xx.c
	drivers/scsi/bfa/bfa_fcpim.c

Needed to update to apply fixes for which the old branch was too
outdated.
2010-12-22 18:57:02 +01:00
Jovi Zhang
5450d90405 kdb: fix crash when KDB_BASE_CMD_MAX is exceeded
When the number of dyanmic kdb commands exceeds KDB_BASE_CMD_MAX, the
kernel will fault.

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-11-17 13:54:57 -06:00
Jovi Zhang
85e76ab50a kdb: fix memory leak in kdb_main.c
Call kfree in the error path as well as the success path in kdb_ll().

Signed-off-by: Jovi Zhang <bookjovi@gmail.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-11-17 13:54:57 -06:00
Uwe Kleine-König
b595076a18 tree-wide: fix comment/printk typos
"gadget", "through", "command", "maintain", "maintain", "controller", "address",
"between", "initiali[zs]e", "instead", "function", "select", "already",
"equal", "access", "management", "hierarchy", "registration", "interest",
"relative", "memory", "offset", "already",

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-11-01 15:38:34 -04:00
Jason Wessel
578bd4dfcd kdb: Fix early debugging crash regression
The kdb_current legally be equal to NULL in the early boot of the x86
arch.  The problem pcan be observed by booting with the kernel arguments:

    earlyprintk=vga ekgdboc=kbd kgdbwait

The kdb shell will oops on entry and recursively fault because it
cannot get past the final stage of shell initialization.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-29 13:14:41 -05:00
Jason Wessel
931ea24819 kdb: fix per_cpu command to remove supress mask
Rusty pointed out that the per_cpu command uses up lots of space on
the stack and the cpu supress mask is probably not needed.

This patch removes the need for the supress mask as well as fixing up
the following problems with the kdb per_cpu command:
  * The per_cpu command should allow an address as an argument
  * When you have more data than can be displayed on one screen allow
    the user to break out of the print loop.

Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-29 13:14:40 -05:00
Jason Wessel
495363d380 kdb,debug_core: adjust master cpu switch logic against new debug_core locking
The kdb shell needs to enforce switching back to the original CPU that
took the exception before restoring normal kernel execution.  Resuming
from a different CPU than what took the original exception will cause
problems with spin locks that are freed from the a different processor
than had taken the lock.

The special logic in dbg_cpu_switch() can go away entirely with
because the state of what cpus want to be masters or slaves will
remain unchanged between entry and exit of the debug_core exception
context.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:13 -05:00
Jason Wessel
91b152aa85 kdb,kgdb: fix sparse fixups
Fix the following sparse warnings:

kdb_main.c:328:5: warning: symbol 'kdbgetu64arg' was not declared. Should it be static?
kgdboc.c:246:12: warning: symbol 'kgdboc_early_init' was not declared. Should it be static?
kgdb.c:652:26: warning: incorrect type in argument 1 (different address spaces)
kgdb.c:652:26:    expected void const *ptr
kgdb.c:652:26:    got struct perf_event *[noderef] <asn:3>*pev

The one in kgdb.c required the (void * __force) because of the return
code from register_wide_hw_breakpoint looking like:

        return (void __percpu __force *)ERR_PTR(err);

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:12 -05:00
Jason Wessel
75d14edee5 kdb: Fix oops in kdb_unregister
Nothing should try to use kdb_commands directly as sometimes it is
null.  Instead, use the for_each_kdbcmd() iterator.

This particular problem dates back to the initial kdb merge (2.6.35),
but at that point nothing was dynamically unregistering commands from
the kdb shell.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:12 -05:00
Jason Wessel
f7030bbc44 kdb: Allow kernel loadable modules to add kdb shell functions
In order to allow kernel modules to dynamically add a command to the
kdb shell the kdb_register, kdb_register_repeat, kdb_unregister, and
kdb_printf need to be exported as GPL symbols.

Any kernel module that adds a dynamic kdb shell function should only
need to include linux/kdb.h.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-10-22 15:34:11 -05:00
Linus Torvalds
79637a41e4 Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  gcc-4.6: kernel/*: Fix unused but set warnings
  mutex: Fix annotations to include it in kernel-locking docbook
  pid: make setpgid() system call use RCU read-side critical section
  MAINTAINERS: Add RCU's public git tree
2010-09-08 11:13:42 -07:00
Andi Kleen
b3bd3de66f gcc-4.6: kernel/*: Fix unused but set warnings
No real bugs I believe, just some dead code.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: andi@firstfloor.org
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-05 14:36:58 +02:00
Linus Torvalds
2637d139fb Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
  Input: pxa27x_keypad - remove input_free_device() in pxa27x_keypad_remove()
  Input: mousedev - fix regression of inverting axes
  Input: uinput - add devname alias to allow module on-demand load
  Input: hil_kbd - fix compile error
  USB: drop tty argument from usb_serial_handle_sysrq_char()
  Input: sysrq - drop tty argument form handle_sysrq()
  Input: sysrq - drop tty argument from sysrq ops handlers
2010-08-28 13:55:31 -07:00
Dmitry Torokhov
f335397d17 Input: sysrq - drop tty argument form handle_sysrq()
Sysrq operations do not accept tty argument anymore so no need to pass
it to us.

[Stephen Rothwell <sfr@canb.auug.org.au>: fix build breakage in drm code
 caused by sysrq using bool but not including linux/types.h]

[Sachin Sant <sachinp@in.ibm.com>: fix build breakage in s390 keyboadr
 driver]

Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2010-08-21 00:34:45 -07:00
Jason Wessel
b590cddfa6 kdb: fix compile error without CONFIG_KALLSYMS
If CONFIG_KGDB_KDB is set and CONFIG_KALLSYMS is not set the kernel
will fail to build with the error:

kernel/built-in.o: In function `kallsyms_symbol_next':
kernel/debug/kdb/kdb_support.c:237: undefined reference to `kdb_walk_kallsyms'
kernel/built-in.o: In function `kallsyms_symbol_complete':
kernel/debug/kdb/kdb_support.c:193: undefined reference to `kdb_walk_kallsyms'

The kdb_walk_kallsyms needs a #ifdef proper header to match the C
implementation.  This patch also fixes the compiler warnings in
kdb_support.c when compiling without CONFIG_KALLSYMS set.  The
compiler warnings are a result of the kallsyms_lookup() macro not
initializing the two of the pass by reference variables.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Reported-by: Michal Simek <monstr@monstr.eu>
2010-08-16 15:58:29 -05:00
Linus Torvalds
b62ad9ab18 Merge branch 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  um: Fix read_persistent_clock fallout
  kgdb: Do not access xtime directly
  powerpc: Clean up obsolete code relating to decrementer and timebase
  powerpc: Rework VDSO gettimeofday to prevent time going backwards
  clocksource: Add __clocksource_updatefreq_hz/khz methods
  x86: Convert common clocksources to use clocksource_register_hz/khz
  timekeeping: Make xtime and wall_to_monotonic static
  hrtimer: Cleanup direct access to wall_to_monotonic
  um: Convert to use read_persistent_clock
  timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset
  powerpc: Cleanup xtime usage
  powerpc: Simplify update_vsyscall
  time: Kill off CONFIG_GENERIC_TIME
  time: Implement timespec_add
  x86: Fix vtime/file timestamp inconsistencies

Trivial conflicts in Documentation/feature-removal-schedule.txt

Much less trivial conflicts in arch/powerpc/kernel/time.c resolved as
per Thomas' earlier merge commit 47916be4e2 ("Merge branch
'powerpc.cherry-picks' into timers/clocksource")
2010-08-06 13:18:29 -07:00
Jason Wessel
81d4450732 vt,console,kdb: automatically set kdb LINES variable
The kernel console interface stores the number of lines it is
configured to use. The kdb debugger can greatly benefit by knowing how
many lines there are on the console for the pager functionality
without having the end user compile in the setting or have to
repeatedly change it at run time.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
CC: David Airlie <airlied@linux.ie>
CC: Andrew Morton <akpm@linux-foundation.org>
2010-08-05 09:22:30 -05:00
Jason Wessel
534af10823 kgdb,kdb: individual register set and and get API
The kdb shell specification includes the ability to get and set
architecture specific registers by name.

For the time being individual register get and set will be implemented
on a per architecture basis.  If an architecture defines
DBG_MAX_REG_NUM > 0 then kdb and the gdbstub will use the capability
for individually getting and setting architecture specific registers.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-08-05 09:22:20 -05:00
Thomas Gleixner
157b1a2385 kgdb: Do not access xtime directly
The xtime cleanup missed the kgdb access to xtime. Fix it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-29 10:29:39 +02:00
Jason Wessel
edd63cb6b9 sysrq,kdb: Use __handle_sysrq() for kdb's sysrq function
The kdb code should not toggle the sysrq state in case an end user
wants to try and resume the normal kernel execution.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2010-07-21 19:27:07 -05:00
Jason Wessel
9e8b624fca Fix merge regression from external kdb to upstream kdb
In the process of merging kdb to the mainline, the kdb lsmod command
stopped printing the base load address of kernel modules.  This is
needed for using kdb in conjunction with external tools such as gdb.

Simply restore the functionality by adding a kdb_printf for the base
load address of the kernel modules.

Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-07-21 19:27:06 -05:00
Martin Hicks
1396a21ba0 kdb: break out of kdb_ll() when command is terminated
Without this patch the "ll" linked-list traversal command won't
terminate when you hit q/Q.

Signed-off-by: Martin Hicks <mort@sgi.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2010-07-21 19:27:05 -05:00
Rusty Russell
c8e21ced08 module: fix kdb's illicit use of struct module_use.
Linus changed the structure, and luckily this didn't compile any more.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Martin Hicks <mort@sgi.com>
2010-06-05 11:17:36 +09:30
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
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
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
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