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path: root/drivers/char/sysrq.c
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2007-05-08header cleaning: don't include smp_lock.h when not usedRandy Dunlap
Remove includes of <linux/smp_lock.h> where it is not used/needed. Suggested by Al Viro. Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc, sparc64, and arm (all 59 defconfigs). Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16[PATCH] Add SysRq-Q to print timer_list debug infoIngo Molnar
Add SysRq-Q to print pending timers and other timer info. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: john stultz <johnstul@us.ibm.com> Cc: Roman Zippel <zippel@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-13[PATCH] Fix SAK_work workqueue initialization.Eric W. Biederman
Somewhere in the rewrite of the work queues my cleanup of SAK handling got broken. Maybe I didn't retest it properly or possibly the API was changing so fast I missed something. Regardless currently triggering a SAK now generates an ugly BUG_ON and kills the kernel. Thanks to Alexey Dobriyan <adobriyan@openvz.org> for spotting this. This modifies the use of SAK_work to initialize it when the data structure it resides in is initialized, and to simply call schedule_work when we need to generate a SAK. I update both data structures that have a SAK_work member for consistency. All of the old PREPARE_WORK calls that are now gone. If we call schedule_work again before it has processed it has generated the first SAK it will simply ignore the duplicate schedule_work request. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-11[PATCH] vt: refactor console SAK processingEric W. Biederman
This does several things. - It moves looking up of the current foreground console into process context where we can safely take the semaphore that protects this operation. - It uses the new flavor of work queue processing. - This generates a factor of do_SAK, __do_SAK that runs immediately. - This calls __do_SAK with the console semaphore held ensuring nothing else happens to the console while we process the SAK operation. - With the console SAK processing moved into process context this patch removes the xchg operations that I used to attempt to attomically update struct pid, because of the strange locking used in the SAK processing. With SAK using the normal console semaphore nothing special is needed. Cc: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-01[PATCH] sysrq: showBlockedTasks is sysrq-WRandy Dunlap
Change SysRq showBlockedTasks from sysrq-X to sysrq-W and show that in the Help message. It was previously done via X, but X is already used for Xmon on ppc & powerpc platforms and this collision needs to be avoided. All callers of register_sysrq_key() are now marked in the sysrq op/key table. I didn't mark 'h' as Help because Help is just printed for any unknown key, such as '?'. Added some omitted sysrq key entries in the sysrq.txt file. Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2006-12-13[PATCH] debug: add sysrq_always_enabled boot optionIngo Molnar
Most distributions enable sysrq support but set it to 0 by default. Add a sysrq_always_enabled boot option to always-enable sysrq keys. Useful for debugging - without having to modify the disribution's config files (which might not be possible if the kernel is on a live CD, etc.). Also, while at it, clean up the sysrq interfaces. [bunk@stusta.de: make sysrq_always_enabled_setup() static] Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-12-07[PATCH] SysRq-X: show blocked tasksIngo Molnar
Add SysRq-X support: show blocked (TASK_UNINTERRUPTIBLE) tasks only. Useful for debugging IO stalls. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-11-22WorkStruct: Pass the work_struct pointer instead of context dataDavid Howells
Pass the work_struct pointer to the work function rather than context data. The work function can use container_of() to work out the data. For the cases where the container of the work_struct may go away the moment the pending bit is cleared, it is made possible to defer the release of the structure by deferring the clearing of the pending bit. To make this work, an extra flag is introduced into the management side of the work_struct. This governs auto-release of the structure upon execution. Ordinarily, the work queue executor would release the work_struct for further scheduling or deallocation by clearing the pending bit prior to jumping to the work function. This means that, unless the driver makes some guarantee itself that the work_struct won't go away, the work function may not access anything else in the work_struct or its container lest they be deallocated.. This is a problem if the auxiliary data is taken away (as done by the last patch). However, if the pending bit is *not* cleared before jumping to the work function, then the work function *may* access the work_struct and its container with no problems. But then the work function must itself release the work_struct by calling work_release(). In most cases, automatic release is fine, so this is the default. Special initiators exist for the non-auto-release case (ending in _NAR). Signed-Off-By: David Howells <dhowells@redhat.com>
2006-10-06[PATCH] sysrq: irq change build fix.Heiko Carstens
drivers/char/sysrq.c: In function `sysrq_handle_crashdump': drivers/char/sysrq.c:98: warning: implicit declaration of function `get_irq_regs' Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2006-10-05IRQ: Maintain regs pointer globally rather than passing to IRQ handlersDavid Howells
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-01[PATCH] sysrq: disable lockdep on rebootPeter Zijlstra
SysRq : Emergency Sync Emergency Sync complete SysRq : Emergency Remount R/O Emergency Remount complete SysRq : Resetting BUG: warning at kernel/lockdep.c:1816/trace_hardirqs_on() (Not tainted) Call Trace: [<ffffffff8026d56d>] show_trace+0xae/0x319 [<ffffffff8026d7ed>] dump_stack+0x15/0x17 [<ffffffff802a68d1>] trace_hardirqs_on+0xbc/0x13d [<ffffffff803a8eec>] sysrq_handle_reboot+0x9/0x11 [<ffffffff803a8f8d>] __handle_sysrq+0x99/0x130 [<ffffffff803a903b>] handle_sysrq+0x17/0x19 [<ffffffff803a36ee>] kbd_event+0x32e/0x57d [<ffffffff80401e35>] input_event+0x42d/0x45b [<ffffffff804063eb>] atkbd_interrupt+0x44d/0x53d [<ffffffff803fe5c5>] serio_interrupt+0x49/0x86 [<ffffffff803ff2a4>] i8042_interrupt+0x202/0x21a [<ffffffff80210cf0>] handle_IRQ_event+0x2c/0x64 [<ffffffff802bfd8b>] __do_IRQ+0xaf/0x114 [<ffffffff8026ea24>] do_IRQ+0xf8/0x107 [<ffffffff8025f886>] ret_from_intr+0x0/0xf DWARF2 unwinder stuck at ret_from_intr+0x0/0xf Leftover inexact backtrace: <IRQ> <EOI> [<ffffffff80258e36>] mwait_idle+0x3f/0x54 [<ffffffff8024a33a>] cpu_idle+0xa2/0xc5 [<ffffffff8026c34e>] rest_init+0x2b/0x2d [<ffffffff809708bc>] start_kernel+0x24a/0x24c [<ffffffff8097028b>] _sinittext+0x28b/0x292 Since we're shutting down anyway, don't bother being smart, just turn the thing off. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-09-29[PATCH] pidspace: is_init()Sukadev Bhattiprolu
This is an updated version of Eric Biederman's is_init() patch. (http://lkml.org/lkml/2006/2/6/280). It applies cleanly to 2.6.18-rc3 and replaces a few more instances of ->pid == 1 with is_init(). Further, is_init() checks pid and thus removes dependency on Eric's other patches for now. Eric's original description: There are a lot of places in the kernel where we test for init because we give it special properties. Most significantly init must not die. This results in code all over the kernel test ->pid == 1. Introduce is_init to capture this case. With multiple pid spaces for all of the cases affected we are looking for only the first process on the system, not some other process that has pid == 1. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com> Cc: Dave Hansen <haveblue@us.ibm.com> Cc: Serge Hallyn <serue@us.ibm.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: <lxc-devel@lists.sourceforge.net> Acked-by: Paul Mackerras <paulus@samba.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] lockdep: print all lock classes on SysRQ-DIngo Molnar
Print all lock-classes on SysRq-D. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-03[PATCH] lockdep: better lock debuggingIngo Molnar
Generic lock debugging: - generalized lock debugging framework. For example, a bug in one lock subsystem turns off debugging in all lock subsystems. - got rid of the caller address passing (__IP__/__IP_DECL__/etc.) from the mutex/rtmutex debugging code: it caused way too much prototype hackery, and lockdep will give the same information anyway. - ability to do silent tests - check lock freeing in vfree too. - more finegrained debugging options, to allow distributions to turn off more expensive debugging features. There's no separate 'held mutexes' list anymore - but there's a 'held locks' stack within lockdep, which unifies deadlock detection across all lock classes. (this is independent of the lockdep validation stuff - lockdep first checks whether we are holding a lock already) Here are the current debugging options: CONFIG_DEBUG_MUTEXES=y CONFIG_DEBUG_LOCK_ALLOC=y which do: config DEBUG_MUTEXES bool "Mutex debugging, basic checks" config DEBUG_LOCK_ALLOC bool "Detect incorrect freeing of live mutexes" Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-03-25[PATCH] sysrq cleanupAndrew Morton
sysrq.c is fairly revolting. Fix. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-02-20[PATCH] Terminate process that fails on a constrained allocationChristoph Lameter
Some allocations are restricted to a limited set of nodes (due to memory policies or cpuset constraints). If the page allocator is not able to find enough memory then that does not mean that overall system memory is low. In particular going postal and more or less randomly shooting at processes is not likely going to help the situation but may just lead to suicide (the whole system coming down). It is better to signal to the process that no memory exists given the constraints that the process (or the configuration of the process) has placed on the allocation behavior. The process may be killed but then the sysadmin or developer can investigate the situation. The solution is similar to what we do when running out of hugepages. This patch adds a check before we kill processes. At that point performance considerations do not matter much so we just scan the zonelist and reconstruct a list of nodes. If the list of nodes does not contain all online nodes then this is a constrained allocation and we should kill the current process. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Andi Kleen <ak@muc.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-09[PATCH] mutex subsystem, more debugging codeIngo Molnar
more mutex debugging: check for held locks during memory freeing, task exit, enable sysrq printouts, etc. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjan@infradead.org>
2005-11-09[PATCH] drivers/char/sysrq.c: make two functions staticAdrian Bunk
This patch makes two needlessly global functions static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-26[PATCH] Update sysrq-B to use emergency_restart()Eric W. Biederman
sysrq calls into the reboot path from an interrupt handler we can either push the code do into process context and call kernel_restart and get a clean reboot or we can simply reboot the machine, and increase our chances of actually rebooting. emergency_reboot() seems like the closest match to what we have previously done, and what we want. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-07[PATCH] print order information when OOM killingMarcelo Tosatti
Dump the current allocation order when OOM killing. Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25[PATCH] kdump: Use real pt_regs from exceptionAlexander Nyberg
Makes kexec_crashdump() take a pt_regs * as an argument. This allows to get exact register state at the point of the crash. If we come from direct panic assertion NULL will be passed and the current registers saved before crashdump. This hooks into two places: die(): check the conditions under which we will panic when calling do_exit and go there directly with the pt_regs that caused the fatal fault. die_nmi(): If we receive an NMI lockup while in the kernel use the pt_regs and go directly to crash_kexec(). We're probably nested up badly at this point so this might be the only chance to escape with proper information. Signed-off-by: Alexander Nyberg <alexn@telia.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25[PATCH] kdump: sysrq trigger mechanism for kexec based crashdumpsHariprasad Nellitheertha
Add a sysrq-trigger mechanism for kexec based crashdumps. Alt-Sysrq-c triggers a kexec based crashdump. Signed-off-by: Hariprasad Nellitheertha <hari@in.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!