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* kdb: Add support for external NMI handler to call KGDB/KDBMike Travis2013-10-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* kgdb/sysrq: fix inconstistent help message of sysrq keyzhangwei(Jovi)2013-04-30
| | | | | | | | | | | | | | | | | | | | | Currently help message of /proc/sysrq-trigger highlight its upper-case characters, like below: SysRq : HELP : loglevel(0-9) reBoot Crash terminate-all-tasks(E) memory-full-oom-kill(F) kill-all-tasks(I) ... this would confuse user trigger sysrq by upper-case character, which is inconsistent with the real lower-case character registed key. This inconsistent help message will also lead more confused when 26 upper-case letters put into use in future. This patch fix kgdb sysrq key: "debug(g)" Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> 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>
* Merge tag 'for_linux-3.9' of ↵Linus Torvalds2013-03-02
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb 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
| * kdb: Remove unhandled ssb commandVincent2013-03-02
| | | | | | | | | | | | | | | | 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>
| * kdb: Prevent kernel oops with kdb_defcmdJason Wessel2013-03-02
| | | | | | | | | | | | | | | | | | | | | | | | 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>
| * kdb: Remove the ll commandJason Wessel2013-03-02
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * kdb_main: fix help printJason Wessel2013-03-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * kdb: Fix overlap in buffers with strcpyJason Wessel2013-03-02
| | | | | | | | | | | | | | | | | | | | | | 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>
| * kdb: Setup basic kdb state before invoking commands via kgdbMatt Klein2013-03-02
| | | | | | | | | | | | | | | | | | | | 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>
| * kdb: use ARRAY_SIZE where possibleSasha Levin2013-03-02
| | | | | | | | | | Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
| * kdb: A fix for kdb command table expansionJohn Blackwood2013-03-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | kgdb: remove #include <linux/serial_8250.h> from kgdb.hGreg Kroah-Hartman2013-02-04
|/ | | | | | | | | There's no reason kgdb.h itself needs to include the 8250 serial port header file. So push it down to the _very_ limited number of individual drivers that need the values in that file, and fix up the places where people really wanted serial_core.h and platform_device.h. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* module: add new state MODULE_STATE_UNFORMED.Rusty Russell2013-01-11
| | | | | | | | | 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>
* Merge tag 'for_linus-3.7' of ↵Linus Torvalds2012-10-12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * kdb,vt_console: Fix missed data due to pager overrunsJason Wessel2012-10-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * kdb: Fix dmesg/bta scroll to quit with 'q'Jason Wessel2012-10-12
| | | | | | | | | | | | | | | | | | 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>
| * kgdb: Add module event hooksJason Wessel2012-10-12
| | | | | | | | | | | | | | | | Allow gdb to auto load kernel modules when it is attached, which makes it trivially easy to debug module init functions or pre-set breakpoints in a kernel module that has not loaded yet. Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
* | kdb: Implement disable_nmi commandAnton Vorontsov2012-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | kernel/debug: Mask KGDB NMI upon entryAnton Vorontsov2012-09-26
|/ | | | | | | | | | | | | | The new arch callback should manage NMIs that usually cause KGDB to enter. That is, not all NMIs should be enabled/disabled, but only those that issue kgdb_handle_exception(). We must mask it as serial-line interrupt can be used as an NMI, so if the original KGDB-entry cause was say a breakpoint, then every input to KDB console will cause KGDB to reenter, which we don't want. 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>
* kernel/debug: Make use of KGDB_REASON_NMIAnton Vorontsov2012-07-31
| | | | | | | | | | | | 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>
* kdb: Remove cpu from the more promptJason Wessel2012-07-31
| | | | | | | 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>
* kdb: Remove unused KDB_FLAG_ONLY_DO_DUMPJason Wessel2012-07-31
| | | | | | | | 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>
* kdb: Switch to nolock variants of kmsg_dump functionsAnton Vorontsov2012-07-21
| | | | | | | | 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>
* printk: Remove kdb_syslog_dataAnton Vorontsov2012-07-21
| | | | | | | 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>
* kdb: Revive dmesg commandAnton Vorontsov2012-07-21
| | | | | | | | | | | | | 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>
* Merge tag 'for_linus-3.4-rc2' of ↵Linus Torvalds2012-04-04
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * kgdb,debug_core: pass the breakpoint struct instead of address and memoryJason Wessel2012-03-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is extra state information that needs to be exposed in the kgdb_bpt structure for tracking how a breakpoint was installed. The debug_core only uses the the probe_kernel_write() to install breakpoints, but this is not enough for all the archs. Some arch such as x86 need to use text_poke() in order to install a breakpoint into a read only page. Passing the kgdb_bpt structure to kgdb_arch_set_breakpoint() and kgdb_arch_remove_breakpoint() allows other archs to set the type variable which indicates how the breakpoint was installed. Cc: stable@vger.kernel.org # >= 2.6.36 Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
| * kdb: Fix smatch warning on dbg_io_ops->is_consoleJason Wessel2012-03-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge tag 'split-asm_system_h-for-linus-20120328' of ↵Linus Torvalds2012-03-28
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