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2015-02-19kdb: Const qualifier for kdb_getstr's prompt argumentDaniel Thompson
All current callers of kdb_getstr() can pass constant pointers via the prompt argument. This patch adds a const qualification to make explicit the fact that this is safe. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2015-02-19kdb: Provide forward search at more promptDaniel Thompson
Currently kdb allows the output of comamnds to be filtered using the | grep feature. This is useful but does not permit the output emitted shortly after a string match to be examined without wading through the entire unfiltered output of the command. Such a feature is particularly useful to navigate function traces because these traces often have a useful trigger string *before* the point of interest. This patch reuses the existing filtering logic to introduce a simple forward search to kdb that can be triggered from the more prompt. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2015-02-19kdb: Fix a prompt management bug when using | grepDaniel Thompson
Currently when the "| grep" feature is used to filter the output of a command then the prompt is not displayed for the subsequent command. Likewise any characters typed by the user are also not echoed to the display. This rather disconcerting problem eventually corrects itself when the user presses Enter and the kdb_grepping_flag is cleared as kdb_parse() tries to make sense of whatever they typed. This patch resolves the problem by moving the clearing of this flag from the middle of command processing to the beginning. Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2015-02-19kdb: Remove stack dump when entering kgdb due to NMIDaniel Thompson
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>
2015-02-19kdb: Avoid printing KERN_ levels to consolesDaniel Thompson
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 04d2c8c83d0e ("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>
2015-02-19kdb: Fix off by one error in kdb_cpu()Jason Wessel
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>
2015-02-19kdb: fix incorrect counts in KDB summary command outputJay Lan
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>
2015-01-23Merge tag 'fixes-for-linus' of ↵Linus Torvalds
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.
2015-01-22module: make module_refcount() a signed integer.Rusty Russell
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>
2014-11-11kgdb: timeout if secondary CPUs ignore the roundupDaniel Thompson
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>
2014-11-11kdb: Allow access to sensitive commands to be restricted by defaultDaniel Thompson
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>
2014-11-11kdb: Add enable mask for groups of commandsAnton Vorontsov
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>
2014-11-11kdb: Categorize kdb commands (similar to SysRq categorization)Daniel Thompson
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>
2014-11-11kdb: Remove KDB_REPEAT_NONE flagAnton Vorontsov
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>
2014-11-11kdb: Use KDB_REPEAT_* values as flagsAnton Vorontsov
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>
2014-11-11kdb: Rename kdb_register_repeat() to kdb_register_flags()Anton Vorontsov
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>
2014-11-11kdb: Rename kdb_repeat_t to kdb_cmdflags_t, cmd_repeat to cmd_flagsAnton Vorontsov
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>
2014-11-11kdb: Remove currently unused kdbtab_t->cmd_flagsAnton Vorontsov
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>
2014-10-14kdb: replace strnicmp with strncasecmpRasmus Villemoes
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>
2014-06-12kdb: Use ktime_get_ts()Thomas Gleixner
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>
2014-06-04kernel/printk: use symbolic defines for console loglevelsBorislav Petkov
... 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>
2013-10-03kdb: Add support for external NMI handler to call KGDB/KDBMike Travis
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>
2013-03-02kdb: Remove unhandled ssb commandVincent
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>
2013-03-02kdb: Prevent kernel oops with kdb_defcmdJason Wessel
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>
2013-03-02kdb: Remove the ll commandJason Wessel
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>
2013-03-02kdb_main: fix help printJason Wessel
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>
2013-03-02kdb: Fix overlap in buffers with strcpyJason Wessel
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>
2013-03-02kdb: Setup basic kdb state before invoking commands via kgdbMatt Klein
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>
2013-03-02kdb: use ARRAY_SIZE where possibleSasha Levin
Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2013-03-02kdb: A fix for kdb command table expansionJohn Blackwood
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>
2013-01-12module: add new state MODULE_STATE_UNFORMED.Rusty Russell
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>
2012-10-13Merge tag 'for_linus-3.7' of ↵Linus Torvalds
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
2012-10-12kdb,vt_console: Fix missed data due to pager overrunsJason Wessel
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>
2012-10-12kdb: Fix dmesg/bta scroll to quit with 'q'Jason Wessel
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>
2012-09-26kdb: Implement disable_nmi commandAnton Vorontsov
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>
2012-07-31kernel/debug: Make use of KGDB_REASON_NMIAnton Vorontsov
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>
2012-07-31kdb: Remove cpu from the more promptJason Wessel
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>
2012-07-31kdb: Remove unused KDB_FLAG_ONLY_DO_DUMPJason Wessel
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>
2012-07-21kdb: Switch to nolock variants of kmsg_dump functionsAnton Vorontsov
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>
2012-07-21printk: Remove kdb_syslog_dataAnton Vorontsov
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>
2012-07-21kdb: Revive dmesg commandAnton Vorontsov
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>
2012-04-04Merge tag 'for_linus-3.4-rc2' of ↵Linus Torvalds
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
2012-03-29kdb: Fix smatch warning on dbg_io_ops->is_consoleJason Wessel
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>
2012-03-28Merge tag 'split-asm_system_h-for-linus-20120328' of ↵Linus Torvalds
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 ...
2012-03-28Remove all #inclusions of asm/system.hDavid Howells
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>
2012-03-23Merge tag 'for_linus-3.4-rc1' of ↵Linus Torvalds
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
2012-03-22kdb: Add message about CONFIG_DEBUG_RODATA on failure to install breakpointJason Wessel
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>
2012-03-22kdb: Avoid using dbg_io_ops until it is initializedTim Bird
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>
2012-03-22KDB: Fix usability issues relating to the 'enter' key.Andrei Warkentin
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>
2012-03-20kdb: remove the second argument of k[un]map_atomic()Cong Wang
Signed-off-by: Cong Wang <amwang@redhat.com>