Commit Graph

58 Commits

Author SHA1 Message Date
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
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
 
 iQIcBAABAgAGBQJQeB8KAAoJEIciOldedpOjpbIP/j+LXEkzXKKfi/3m79VQ87DB
 5iUmTS84t84pomHamXX175AC0gA/2mC0FbbcHpqjlhxF4awXcviCNIiTdtSOTbbu
 G102naLHY8i77X+XbHuN2utJeaRLw8rsfMMZGmjJnjfpc4LtsaH0YTkUzbt3qvba
 N6/QvknadzIrmoCJvHipdOdsSmL0YmTS22+koG4es9B5jvOqVH/W7jZs1qRlVw96
 VxG5Psx4LPB+RI+ZwF1WwbGxbtqKGwkVvkcGG1XIW7FQojHmjw+vUERQCjoFueJ5
 NkKfus98j85/+MvSTkWx3L1K46MHMCFbtJs9RWftJ8GtoNNnm7GDxasoIG2bJKyG
 HFD3IGPuKAokE/equF3eGTRHeEM0IUGwT3EnBqdKd73zud27WsHaSqC/1CPR+74v
 ojLQ2ft1QF+pEkGrhRTdQpLyVnvEmxu8q+j9z9n/HlGEVv8kZ6LGxDPjWB+um/Yi
 Cs0XAryYrL5gE5O+Vwna61luughtIYJwR7+DeVxnQYJ43x/0MtN/SoURnwvrCTEo
 9FeoMgZm1nLh6EW29ahIT/hMu4f0sM91Kiwrmc/zEWZgoB++wo1n470qQmUUrOx4
 CPD7zdmDrf6YxDG2QTHjCtVErO4aJ5zN4Dq0+YyodV545SZVn3t4qBDTVvKhq4Y6
 NIhZAxrv5RKABwtLcP9E
 =uf0L
 -----END PGP SIGNATURE-----

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
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
 
 iQIcBAABAgAGBQJPedocAAoJEIciOldedpOjn7EP/397Rh0zmRlG8oQwMEJcK3E5
 gaRyBNpkGoU3ekHXHx/nzgQ/CS9opzW7nBZDu8weWLjRKMT4RyHfuJcWyu525GvQ
 SnoiX2ZUzP315d8llCYwXmaCEYA7lHQi4T2bGMlDSn1J8kS235EQxllgEfhXDdEC
 DxRWgHABG2UR62C62sGKbPaMMDO9TcNcrAQK27LDLTS7pKLmYqBWBdZKgWzBM/Pr
 AF8vakqSgUw3Aq9qrLge+483uT7uhMoUJofxRppWtm1QgnDcTmri9LOagiazDotz
 RQliRGwVxj9hEo5mLEiQtI0N1kIGCAsK0+9aUJEZRXovRBR9kvqaqHT4c5xdhznr
 VKYvqqTcHBkKLIfNXFvQZnn2cXtNVNqve9CZZwdBJaFYEkaR7ZVQqE6f2xq8KAb2
 RmhvzlEUyLU+89YKkH66uSa22VLSazkeH+4b8AJ4JxYDEab3BHoBCe8axcBQrTsj
 7X5NOs7V3Oj+4J3bS1fbUbxq4t0dfpLLyg8e/lELWtT+Kq7nQRzA2XHRZAMTve8M
 T0cTdrwtUbgY9ZMTpywNB2KlPgTvhWOyfYbH6/Kcks7ecSXlkow3edXoiUbw79iE
 hP8vcMWbT2Rv3IbLkSMFZEQGAG9qL1YyGv4NDmLOoljO1c/Bi3WQIR5aI+di6asV
 Z5q5s/bmGa4+OhFFITSd
 =SW2N
 -----END PGP SIGNATURE-----

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
-----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.12 (GNU/Linux)
 
 iQIVAwUAT3NKzROxKuMESys7AQKElw/+JyDxJSlj+g+nymkx8IVVuU8CsEwNLgRk
 8KEnRfLhGtkXFLSJYWO6jzGo16F8Uqli1PdMFte/wagSv0285/HZaKlkkBVHdJ/m
 u40oSjgT013bBh6MQ0Oaf8pFezFUiQB5zPOA9QGaLVGDLXCmgqUgd7exaD5wRIwB
 ZmyItjZeAVnDfk1R+ZiNYytHAi8A5wSB+eFDCIQYgyulA1Igd1UnRtx+dRKbvc/m
 rWQ6KWbZHIdvP1ksd8wHHkrlUD2pEeJ8glJLsZUhMm/5oMf/8RmOCvmo8rvE/qwl
 eDQ1h4cGYlfjobxXZMHqAN9m7Jg2bI946HZjdb7/7oCeO6VW3FwPZ/Ic75p+wp45
 HXJTItufERYk6QxShiOKvA+QexnYwY0IT5oRP4DrhdVB/X9cl2MoaZHC+RbYLQy+
 /5VNZKi38iK4F9AbFamS7kd0i5QszA/ZzEzKZ6VMuOp3W/fagpn4ZJT1LIA3m4A9
 Q0cj24mqeyCfjysu0TMbPtaN+Yjeu1o1OFRvM8XffbZsp5bNzuTDEvviJ2NXw4vK
 4qUHulhYSEWcu9YgAZXvEWDEM78FXCkg2v/CrZXH5tyc95kUkMPcgG+QZBB5wElR
 FaOKpiC/BuNIGEf02IZQ4nfDxE90QwnDeoYeV+FvNj9UEOopJ5z5bMPoTHxm4cCD
 NypQthI85pc=
 =G9mT
 -----END PGP SIGNATURE-----

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
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.11 (GNU/Linux)
 
 iQIcBAABAgAGBQJPbJ17AAoJEIciOldedpOjQeIP/AkUxQFJ7O4aLrLYHl62EHnh
 spkgkd+nBzIzcKyV73alkrVBaR2WE2822aAPQmAPBP8/X283DZJJjqgDCUNVI1Mf
 CIZ7g8AQHRnS+bAZmof5Jss4malZn4byLvG/cfpOivrsye+4A8MdrAKKM3pYWNVy
 4xABkcEknVEEamdNEhHrcPd+xehretfw7+9mmU8hfjqHb/5cXFB7JwDcf4tF7ozT
 MDyN4xKtOn1W/ftQl0t6izksCUuPyqKzIfUyAy0j6AwTgsEavXu56S52T1UoB2ZI
 JcwLn/ZpN4eGCWVodY04R3jzaMtKFb6ImY40wsb5wl3CU3Ecy5syMU6z4fg3cvjH
 /KE6xWF61j4yiE5lzjeJVtKyxwalthzrr56qU2uEwrsEVmo3SOnW9sm0cwouqa7j
 /TAMlhZuGgbZGesFwdaUKI5OLGoki+pRQ0Gaq3TsbZwpPC5Bimkq0bIvruruKJCP
 QWVkEvb5TZgxCFS3AvniePOm7Hc2wD9zXB3OfN3o91pCom0ryDBIthcLlwhVeNCo
 Jd67pnJJNVULPF/1qVicZihKHxvG3DUb4E9pUcbgJplBke+isi+3eHOvnQrYFjIG
 iCamE9qvVbsQm/OFV8MOJ5mfPs9R+nb/jNzTO8JDmBc8AL7nRDV3AFGjW68x/KWT
 ERcqNEGJ4QuVAxfejq76
 =SXu9
 -----END PGP SIGNATURE-----

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