24 May, 2016

1 commit

  • With VT=n, the kernel build fails with:

    drivers/built-in.o: In function `kgdboc_pre_exp_handler':
    kgdboc.c:(.text+0x7b5aa): undefined reference to `fg_console'
    kgdboc.c:(.text+0x7b5ce): undefined reference to `vc_cons'
    kgdboc.c:(.text+0x7b5d5): undefined reference to `vc_cons'

    kgdboc.o is built when KGDB_SERIAL_CONSOLE is set. So make
    KGDB_SERIAL_CONSOLE depend on HW_CONSOLE which includes those symbols.

    Link: http://lkml.kernel.org/r/1459412955-4696-1-git-send-email-jslaby@suse.cz
    Signed-off-by: Jiri Slaby
    Reported-by: "Jim Davis"
    Acked-by: Jason Wessel
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Jiri Slaby
     

11 Nov, 2014

1 commit


18 Jun, 2013

1 commit


03 Mar, 2013

1 commit

  • Pull KGDB/KDB fixes and cleanups from Jason Wessel:
    "For a change we removed more code than we added. If people aren't
    using it we shouldn't be carrying it. :-)

    Cleanups:
    - Remove kdb ssb command - there is no in kernel disassembler to
    support it

    - Remove kdb ll command - Always caused a kernel oops and there were
    no bug reports so no one was using this command

    - Use kernel ARRAY_SIZE macro instead of array computations

    Fixes:
    - Stop oops in kdb if user executes kdb_defcmd with args

    - kdb help command truncated text

    - ppc64 support for kgdbts

    - Add missing kconfig option from original kdb port for dealing with
    catastrophic kernel crashes such that you can reboot automatically
    on continue from kdb"

    * tag 'for_linux-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
    kdb: Remove unhandled ssb command
    kdb: Prevent kernel oops with kdb_defcmd
    kdb: Remove the ll command
    kdb_main: fix help print
    kdb: Fix overlap in buffers with strcpy
    Fixed dead ifdef block by adding missing Kconfig option.
    kdb: Setup basic kdb state before invoking commands via kgdb
    kdb: use ARRAY_SIZE where possible
    kgdb/kgdbts: support ppc64
    kdb: A fix for kdb command table expansion

    Linus Torvalds
     

02 Mar, 2013

1 commit

  • Added missing Kconfig option KDB_CONTINUE_CATASTROPHIC which lead to a dead
    ifdef block in kernel/debug/kdb/kdb_main.c:73-75.

    The code using KDB_CONTINUE_CATASTROPHIC was originally introduced in
    commit '5d5314d6795f3c1c0f415348ff8c51f7de042b77' by Jason Wessel.
    This patchset ("kdb: core for kgdb back end (1 of 2)")
    added platform independent part of kdb to the linux kernel.

    The Kernel option however, even though it had the same options and
    behaviour on all supported architectures, was part of the x86 and
    ia64 patchset of KDB and therefore not pulled into the mainline kernel tree.

    I actually took the originally written Kconfig by
    Keith Owens (2003-06-20 according to KDB changelog)
    and changed it to reflect the correct behaviour,
    as the KDUMP patchset is not part of the kernel and the expected
    functionality is missing from it.

    Signed-off-by: Robert Obermeier
    Signed-off-by: Jason Wessel

    Robert Obermeier
     

22 Feb, 2013

1 commit

  • Pull tty/serial patches from Greg Kroah-Hartman:
    "Here's the big tty/serial driver patches for 3.9-rc1.

    More tty port rework and fixes from Jiri here, as well as lots of
    individual serial driver updates and fixes.

    All of these have been in the linux-next tree for a while."

    * tag 'tty-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (140 commits)
    tty: mxser: improve error handling in mxser_probe() and mxser_module_init()
    serial: imx: fix uninitialized variable warning
    serial: tegra: assume CONFIG_OF
    TTY: do not update atime/mtime on read/write
    lguest: select CONFIG_TTY to build properly.
    ARM defconfigs: add missing inclusions of linux/platform_device.h
    fb/exynos: include platform_device.h
    ARM: sa1100/assabet: include platform_device.h directly
    serial: imx: Fix recursive locking bug
    pps: Fix build breakage from decoupling pps from tty
    tty: Remove ancient hardpps()
    pps: Additional cleanups in uart_handle_dcd_change
    pps: Move timestamp read into PPS code proper
    pps: Don't crash the machine when exiting will do
    pps: Fix a use-after free bug when unregistering a source.
    pps: Use pps_lookup_dev to reduce ldisc coupling
    pps: Add pps_lookup_dev() function
    tty: serial: uartlite: Support uartlite on big and little endian systems
    tty: serial: uartlite: Fix sparse and checkpatch warnings
    serial/arc-uart: Miscll DT related updates (Grant's review comments)
    ...

    Fix up trivial conflicts, mostly just due to the TTY config option
    clashing with the EXPERIMENTAL removal.

    Linus Torvalds
     

19 Jan, 2013

1 commit

  • The option allows you to remove TTY and compile without errors. This
    saves space on systems that won't support TTY interfaces anyway.
    bloat-o-meter output is below.

    The bulk of this patch consists of Kconfig changes adding "depends on
    TTY" to various serial devices and similar drivers that require the TTY
    layer. Ideally, these dependencies would occur on a common intermediate
    symbol such as SERIO, but most drivers "select SERIO" rather than
    "depends on SERIO", and "select" does not respect dependencies.

    bloat-o-meter output comparing our previous minimal to new minimal by
    removing TTY. The list is filtered to not show removed entries with awk
    '$3 != "-"' as the list was very long.

    add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
    function old new delta
    chr_dev_init 166 170 +4
    allow_signal 80 82 +2
    static.__warned 143 142 -1
    disallow_signal 63 62 -1
    __set_special_pids 95 94 -1
    unregister_console 126 121 -5
    start_kernel 546 541 -5
    register_console 593 588 -5
    copy_from_user 45 40 -5
    sys_setsid 128 120 -8
    sys_vhangup 32 19 -13
    do_exit 1543 1526 -17
    bitmap_zero 60 40 -20
    arch_local_irq_save 137 117 -20
    release_task 674 652 -22
    static.spin_unlock_irqrestore 308 260 -48

    Signed-off-by: Joe Millenbach
    Reviewed-by: Jamey Sharp
    Reviewed-by: Josh Triplett
    Signed-off-by: Greg Kroah-Hartman

    Joe Millenbach
     

18 Jan, 2013

1 commit

  • The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
    while now and is almost always enabled by default. As agreed during the
    Linux kernel summit, remove it from any "depends on" lines in Kconfigs.

    CC: Andrew Morton
    Acked-by: Paul E. McKenney
    CC: Dmitry Kasatkin
    CC: James Morris
    CC: "Michael S. Tsirkin"
    CC: Akinobu Mita
    CC: Ingo Molnar
    Cc: Greg Kroah-Hartman
    Signed-off-by: Kees Cook
    Acked-by: Catalin Marinas
    Signed-off-by: Greg Kroah-Hartman

    Kees Cook
     

21 May, 2010

4 commits

  • The only way the debugger can handle a trap in inside rcu_lock,
    notify_die, or atomic_notifier_call_chain without a recursive fault is
    to have a low level "first opportunity handler" do_trap_or_bp() handler.

    Generally this will be something the vast majority of folks will not
    need, but for those who need it, it is added as a kernel .config
    option called KGDB_LOW_LEVEL_TRAP.

    Also added was a die notification for oops such that kdb can catch an
    oops for analysis.

    There appeared to be no obvious way to pass the struct pt_regs from
    the original exception back to the stack back tracer, so a special
    case was added to show_stack() for when kdb is active because you
    generally desire to generally look at the back trace of the original
    exception.

    Signed-off-by: Jason Wessel
    Acked-by: Ralf Baechle

    Jason Wessel
     
  • The only way the debugger can handle a trap in inside rcu_lock,
    notify_die, or atomic_notifier_call_chain without a triple fault is
    to have a low level "first opportunity handler" in the int3 exception
    handler.

    Generally this will be something the vast majority of folks will not
    need, but for those who need it, it is added as a kernel .config
    option called KGDB_LOW_LEVEL_TRAP.

    CC: Ingo Molnar
    CC: Thomas Gleixner
    CC: H. Peter Anvin
    CC: x86@kernel.org
    Signed-off-by: Jason Wessel

    Jason Wessel
     
  • 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
    Reviewed-by: Dmitry Torokhov

    Jason Wessel
     
  • These are the minimum changes to the kgdb core in order to enable an
    API to connect a new front end (kdb) to the debug core.

    This patch introduces the dbg_kdb_mode variable controls where the
    user level I/O is routed. It will be routed to the gdbstub (kgdb) or
    to the kdb front end which is a simple shell available over the kgdboc
    connection.

    You can switch back and forth between kdb or the gdb stub mode of
    operation dynamically. From gdb stub mode you can blindly type
    "$3#33", or from the kdb mode you can enter "kgdb" to switch to the
    gdb stub.

    The logic in the debug core depends on kdb to look for the typical gdb
    connection sequences and return immediately with KGDB_PASS_EVENT if a
    gdb serial command sequence is detected. That should allow a
    reasonably seamless transition between kdb -> gdb without leaving the
    kernel exception state. The two gdb serial queries that kdb is
    responsible for detecting are the "?" and "qSupported" packets.

    CC: Ingo Molnar
    Signed-off-by: Jason Wessel
    Acked-by: Martin Hicks

    Jason Wessel
     

01 Aug, 2008

1 commit


24 Jul, 2008

1 commit


05 May, 2008

1 commit


18 Apr, 2008

3 commits

  • This patch adds in the ability to compile the kgdb internal test
    string into the kernel so as to run the tests at boot without changing
    the kernel boot arguments. This patch also changes all the error
    paths to invoke WARN_ON(1) which will emit the line number of the file
    and dump the kernel stack when an error occurs.

    You can disable the tests in a kernel that is built this way
    using "kgdbts="

    Signed-off-by: Jason Wessel
    Signed-off-by: Ingo Molnar

    Jason Wessel
     
  • This patch adds regression tests for testing the kgdb core and arch
    specific implementation.

    The kgdb test suite is designed to be built into the kernel and not as
    a module because it uses a number of low level kernel and kgdb
    primitives which should not be exported externally.

    The kgdb test suite is designed as a KGDB I/O module which
    simulates the communications that a debugger would have with kgdb.
    The tests are broken up in to a line by line and referenced here as
    a "get" which is kgdb requesting input and "put" which is kgdb
    sending a response.

    The kgdb suite can be invoked from the kernel command line
    arguments system or executed dynamically at run time. The test
    suite uses the variable "kgdbts" to obtain the information about
    which tests to run and to configure the verbosity level. The
    following are the various characters you can use with the kgdbts=
    line:

    When using the "kgdbts=" you only choose one of the following core
    test types:
    A = Run all the core tests silently
    V1 = Run all the core tests with minimal output
    V2 = Run all the core tests in debug mode

    You can also specify optional tests:
    N## = Go to sleep with interrupts of for ## seconds
    to test the HW NMI watchdog
    F## = Break at do_fork for ## iterations
    S## = Break at sys_open for ## iterations

    NOTE: that the do_fork and sys_open tests are mutually exclusive.

    To invoke the kgdb test suite from boot you use a kernel start
    argument as follows:
    kgdbts=V1 kgdbwait
    Or if you wanted to perform the NMI test for 6 seconds and do_fork
    test for 100 forks, you could use:
    kgdbts=V1N6F100 kgdbwait

    The test suite can also be invoked at run time with:
    echo kgdbts=V1N6F100 > /sys/module/kgdbts/parameters/kgdbts
    Or as another example:
    echo kgdbts=V2 > /sys/module/kgdbts/parameters/kgdbts

    When developing a new kgdb arch specific implementation or
    using these tests for the purpose of regression testing,
    several invocations are required.

    1) Boot with the test suite enabled by using the kernel arguments
    "kgdbts=V1F100 kgdbwait"
    ## If kgdb arch specific implementation has NMI use
    "kgdbts=V1N6F100

    2) After the system boot run the basic test.
    echo kgdbts=V1 > /sys/module/kgdbts/parameters/kgdbts

    3) Run the concurrency tests. It is best to use n+1
    while loops where n is the number of cpus you have
    in your system. The example below uses only two
    loops.

    ## This tests break points on sys_open
    while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
    while [ 1 ] ; do find / > /dev/null 2>&1 ; done &
    echo kgdbts=V1S10000 > /sys/module/kgdbts/parameters/kgdbts
    fg # and hit control-c
    fg # and hit control-c
    ## This tests break points on do_fork
    while [ 1 ] ; do date > /dev/null ; done &
    while [ 1 ] ; do date > /dev/null ; done &
    echo kgdbts=V1F1000 > /sys/module/kgdbts/parameters/kgdbts
    fg # and hit control-c

    Signed-off-by: Jason Wessel
    Signed-off-by: Ingo Molnar

    Jason Wessel
     
  • kgdb core code. Handles the protocol and the arch details.

    [ mingo@elte.hu: heavily modified, simplified and cleaned up. ]
    [ xemul@openvz.org: use find_task_by_pid_ns ]

    Signed-off-by: Jason Wessel
    Signed-off-by: Ingo Molnar
    Signed-off-by: Jan Kiszka
    Reviewed-by: Thomas Gleixner

    Jason Wessel