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path: root/drivers/tty/sysrq.c
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2017-01-11sysrq: attach sysrq handler correctly for 32-bit kernelAkinobu Mita
The sysrq input handler should be attached to the input device which has a left alt key. On 32-bit kernels, some input devices which has a left alt key cannot attach sysrq handler. Because the keybit bitmap in struct input_device_id for sysrq is not correctly initialized. KEY_LEFTALT is 56 which is greater than BITS_PER_LONG on 32-bit kernels. I found this problem when using a matrix keypad device which defines a KEY_LEFTALT (56) but doesn't have a KEY_O (24 == 56%32). Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-07-26mm: oom: add memcg to oom_controlVladimir Davydov
It's a part of oom context just like allocation order and nodemask, so let's move it to oom_control instead of passing it in the argument list. Link: http://lkml.kernel.org/r/40e03fd7aaf1f55c75d787128d6d17c5a71226c2.1464358556.git.vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-29sysrq: Fix warning in sysrq generated crash.Ani Sinha
Commit 984d74a72076a1 ("sysrq: rcu-ify __handle_sysrq") replaced spin_lock_irqsave() calls with rcu_read_lock() calls in sysrq. Since rcu_read_lock() does not disable preemption, faulthandler_disabled() in __do_page_fault() in x86/fault.c returns false. When the code later calls might_sleep() in the pagefault handler, we get the following warning: BUG: sleeping function called from invalid context at ../arch/x86/mm/fault.c:1187 in_atomic(): 0, irqs_disabled(): 0, pid: 4706, name: bash Preemption disabled at:[<ffffffff81484339>] printk+0x48/0x4a To fix this, we release the RCU read lock before we crash. Tested this patch on linux 3.18 by booting off one of our boards. Fixes: 984d74a72076a1 ("sysrq: rcu-ify __handle_sysrq") Signed-off-by: Ani Sinha <ani@arista.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-10-04drivers/tty: make sysrq.c slightly more explicitly non-modularPaul Gortmaker
The Kconfig currently controlling compilation of this code is: config.debug:config MAGIC_SYSRQ bool "Magic SysRq key" ...meaning that it currently is not being built as a module by anyone. Lets remove the traces of modularity we can so that when reading the driver there is less doubt it is builtin-only. Since module_init translates to device_initcall in the non-modular case, the init ordering remains unchanged with this commit. We don't delete the module.h include since other parts of the file are using content from there. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-08mm, oom: pass an oom order of -1 when triggered by sysrqDavid Rientjes
The force_kill member of struct oom_control isn't needed if an order of -1 is used instead. This is the same as order == -1 in struct compact_control which requires full memory compaction. This patch introduces no functional change. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08mm, oom: organize oom context into structDavid Rientjes
There are essential elements to an oom context that are passed around to multiple functions. Organize these elements into a new struct, struct oom_control, that specifies the context for an oom condition. This patch introduces no functional change. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-07-01Merge tag 'modules-next-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module updates from Rusty Russell: "Main excitement here is Peter Zijlstra's lockless rbtree optimization to speed module address lookup. He found some abusers of the module lock doing that too. A little bit of parameter work here too; including Dan Streetman's breaking up the big param mutex so writing a parameter can load another module (yeah, really). Unfortunately that broke the usual suspects, !CONFIG_MODULES and !CONFIG_SYSFS, so those fixes were appended too" * tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (26 commits) modules: only use mod->param_lock if CONFIG_MODULES param: fix module param locks when !CONFIG_SYSFS. rcu: merge fix for Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() module: add per-module param_lock module: make perm const params: suppress unused variable error, warn once just in case code changes. modules: clarify CONFIG_MODULE_COMPRESS help, suggest 'N'. kernel/module.c: avoid ifdefs for sig_enforce declaration kernel/workqueue.c: remove ifdefs over wq_power_efficient kernel/params.c: export param_ops_bool_enable_only kernel/params.c: generalize bool_enable_only kernel/module.c: use generic module param operaters for sig_enforce kernel/params: constify struct kernel_param_ops uses sysfs: tightened sysfs permission checks module: Rework module_addr_{min,max} module: Use __module_address() for module_address_lookup() module: Make the mod_tree stuff conditional on PERF_EVENTS || TRACING module: Optimize __module_address() using a latched RB-tree rbtree: Implement generic latch_tree seqlock: Introduce raw_read_seqcount_latch() ...
2015-06-27Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS updates from Ralf Baechle: - Improvements to the tlb_dump code - KVM fixes - Add support for appended DTB - Minor improvements to the R12000 support - Minor improvements to the R12000 support - Various platform improvments for BCM47xx - The usual pile of minor cleanups - A number of BPF fixes and improvments - Some improvments to the support for R3000 and DECstations - Some improvments to the ATH79 platform support - A major patchset for the JZ4740 SOC adding support for the CI20 platform - Add support for the Pistachio SOC - Minor BMIPS/BCM63xx platform support improvments. - Avoid "SYNC 0" as memory barrier when unlocking spinlocks - Add support for the XWR-1750 board. - Paul's __cpuinit/__cpuinitdata cleanups. - New Malta CPU board support large memory so enable ZONE_DMA32. * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (131 commits) MIPS: spinlock: Adjust arch_spin_lock back-off time MIPS: asmmacro: Ensure 64-bit FP registers are used with MSA MIPS: BCM47xx: Simplify handling SPROM revisions MIPS: Cobalt Don't use module_init in non-modular MTD registration. MIPS: BCM47xx: Move NVRAM driver to the drivers/firmware/ MIPS: use for_each_sg() MIPS: BCM47xx: Don't select BCMA_HOST_PCI MIPS: BCM47xx: Add helper variable for storing NVRAM length MIPS: IRQ/IP27: Move IRQ allocation API to platform code. MIPS: Replace smp_mb with release barrier function in unlocks. MIPS: i8259: DT support MIPS: Malta: Basic DT plumbing MIPS: include errno.h for ENODEV in mips-cm.h MIPS: Define GCR_GIC_STATUS register fields MIPS: BPF: Introduce BPF ASM helpers MIPS: BPF: Use BPF register names to describe the ABI MIPS: BPF: Move register definition to the BPF header MIPS: net: BPF: Replace RSIZE with SZREG MIPS: BPF: Free up some callee-saved registers MIPS: Xtalk: Update xwidget.h with known Xtalk device numbers ...
2015-06-24Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge first patchbomb from Andrew Morton: - a few misc things - ocfs2 udpates - kernel/watchdog.c feature work (took ages to get right) - most of MM. A few tricky bits are held up and probably won't make 4.2. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (91 commits) mm: kmemleak_alloc_percpu() should follow the gfp from per_alloc() mm, thp: respect MPOL_PREFERRED policy with non-local node tmpfs: truncate prealloc blocks past i_size mm/memory hotplug: print the last vmemmap region at the end of hot add memory mm/mmap.c: optimization of do_mmap_pgoff function mm: kmemleak: optimise kmemleak_lock acquiring during kmemleak_scan mm: kmemleak: avoid deadlock on the kmemleak object insertion error path mm: kmemleak: do not acquire scan_mutex in kmemleak_do_cleanup() mm: kmemleak: fix delete_object_*() race when called on the same memory block mm: kmemleak: allow safe memory scanning during kmemleak disabling memcg: convert mem_cgroup->under_oom from atomic_t to int memcg: remove unused mem_cgroup->oom_wakeups frontswap: allow multiple backends x86, mirror: x86 enabling - find mirrored memory ranges mm/memblock: allocate boot time data structures from mirrored memory mm/memblock: add extra "flags" to memblock to allow selection of memory based on attribute mm: do not ignore mapping_gfp_mask in page cache allocation paths mm/cma.c: fix typos in comments mm/oom_kill.c: print points as unsigned int mm/hugetlb: handle races in alloc_huge_page and hugetlb_reserve_pages ...
2015-06-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input subsystem updates from Dmitry Torokhov: "Thanks to Samuel Thibault input device (keyboard) LEDs are no longer hardwired within the input core but use LED subsystem and so allow use of different triggers; Hans de Goede did a large update for the ALPS touchpad driver; we have new TI drv2665 haptics driver and DA9063 OnKey driver, and host of other drivers got various fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (55 commits) Input: pixcir_i2c_ts - fix receive error MAINTAINERS: remove non existent input mt git tree Input: improve usage of gpiod API tty/vt/keyboard: define LED triggers for VT keyboard lock states tty/vt/keyboard: define LED triggers for VT LED states Input: export LEDs as class devices in sysfs Input: cyttsp4 - use swap() in cyttsp4_get_touch() Input: goodix - do not explicitly set evbits in input device Input: goodix - export id and version read from device Input: goodix - fix variable length array warning Input: goodix - fix alignment issues Input: add OnKey driver for DA9063 MFD part Input: elan_i2c - add product IDs FW names Input: elan_i2c - add support for multi IC type and iap format Input: focaltech - report finger width to userspace tty: remove platform_sysrq_reset_seq Input: synaptics_i2c - use proper boolean values Input: psmouse - use true instead of 1 for boolean values Input: cyapa - fix a few typos in comments Input: stmpe-ts - enforce device tree only mode ...
2015-06-24mm: oom_kill: simplify OOM killer lockingJohannes Weiner
The zonelist locking and the oom_sem are two overlapping locks that are used to serialize global OOM killing against different things. The historical zonelist locking serializes OOM kills from allocations with overlapping zonelists against each other to prevent killing more tasks than necessary in the same memory domain. Only when neither tasklists nor zonelists from two concurrent OOM kills overlap (tasks in separate memcgs bound to separate nodes) are OOM kills allowed to execute in parallel. The younger oom_sem is a read-write lock to serialize OOM killing against the PM code trying to disable the OOM killer altogether. However, the OOM killer is a fairly cold error path, there is really no reason to optimize for highly performant and concurrent OOM kills. And the oom_sem is just flat-out redundant. Replace both locking schemes with a single global mutex serializing OOM kills regardless of context. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-21MIPS: Add SysRq operation to dump TLBs on all CPUsJames Hogan
Add a MIPS specific SysRq operation to dump the TLB entries on all CPUs, using the 'x' trigger key. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/10072/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-06-02tty: remove platform_sysrq_reset_seqArnd Bergmann
The platform_sysrq_reset_seq code was intended as a way for an embedded platform to provide its own sysrq sequence at compile time. After over two years, nobody has started using it in an upstream kernel, and the platforms that were interested in it have moved on to devicetree, which can be used to configure the sequence without requiring kernel changes. The method is also incompatible with the way that most architectures build support for multiple platforms into a single kernel. Now the code is producing warnings when built with gcc-5.1: drivers/tty/sysrq.c: In function 'sysrq_init': drivers/tty/sysrq.c:959:33: warning: array subscript is above array bounds [-Warray-bounds] key = platform_sysrq_reset_seq[i]; We could fix this, but it seems unlikely that it will ever be used, so let's just remove the code instead. We still have the option to pass the sequence either in DT, using the kernel command line, or using the /sys/module/sysrq/parameters/reset_seq file. Fixes: 154b7a489a ("Input: sysrq - allow specifying alternate reset sequence") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2015-05-28kernel/params: constify struct kernel_param_ops usesLuis R. Rodriguez
Most code already uses consts for the struct kernel_param_ops, sweep the kernel for the last offending stragglers. Other than include/linux/moduleparam.h and kernel/params.c all other changes were generated with the following Coccinelle SmPL patch. Merge conflicts between trees can be handled with Coccinelle. In the future git could get Coccinelle merge support to deal with patch --> fail --> grammar --> Coccinelle --> new patch conflicts automatically for us on patches where the grammar is available and the patch is of high confidence. Consider this a feature request. Test compiled on x86_64 against: * allnoconfig * allmodconfig * allyesconfig @ const_found @ identifier ops; @@ const struct kernel_param_ops ops = { }; @ const_not_found depends on !const_found @ identifier ops; @@ -struct kernel_param_ops ops = { +const struct kernel_param_ops ops = { }; Generated-by: Coccinelle SmPL Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Junio C Hamano <gitster@pobox.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Kees Cook <keescook@chromium.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: cocci@systeme.lip6.fr Cc: linux-kernel@vger.kernel.org Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2015-03-09workqueue: dump workqueues on sysrq-tTejun Heo
Workqueues are used extensively throughout the kernel but sometimes it's difficult to debug stalls involving work items because visibility into its inner workings is fairly limited. Although sysrq-t task dump annotates each active worker task with the information on the work item being executed, it is challenging to find out which work items are pending or delayed on which queues and how pools are being managed. This patch implements show_workqueue_state() which dumps all busy workqueues and pools and is called from the sysrq-t handler. At the end of sysrq-t dump, something like the following is printed. Showing busy workqueues and worker pools: ... workqueue filler_wq: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=2/256 in-flight: 491:filler_workfn, 507:filler_workfn pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=2/256 in-flight: 501:filler_workfn pending: filler_workfn ... workqueue test_wq: flags=0x8 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=1/1 in-flight: 510(RESCUER):test_workfn BAR(69) BAR(500) delayed: test_workfn1 BAR(492), test_workfn2 ... pool 0: cpus=0 node=0 flags=0x0 nice=0 workers=2 manager: 137 pool 2: cpus=1 node=0 flags=0x0 nice=0 workers=3 manager: 469 pool 3: cpus=1 node=0 flags=0x0 nice=-20 workers=2 idle: 16 pool 8: cpus=0-3 flags=0x4 nice=0 workers=2 manager: 62 The above shows that test_wq is executing test_workfn() on pid 510 which is the rescuer and also that there are two tasks 69 and 500 waiting for the work item to finish in flush_work(). As test_wq has max_active of 1, there are two work items for test_workfn1() and test_workfn2() which are delayed till the current work item is finished. In addition, pid 492 is flushing test_workfn1(). The work item for test_workfn() is being executed on pwq of pool 2 which is the normal priority per-cpu pool for CPU 1. The pool has three workers, two of which are executing filler_workfn() for filler_wq and the last one is assuming the manager role trying to create more workers. This extra workqueue state dump will hopefully help chasing down hangs involving workqueues. v3: cpulist_pr_cont() replaced with "%*pbl" printf formatting. v2: As suggested by Andrew, minor formatting change in pr_cont_work(), printk()'s replaced with pr_info()'s, and cpumask printing now uses cpulist_pr_cont(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> CC: Ingo Molnar <mingo@redhat.com>
2015-02-11oom, PM: make OOM detection in the freezer path racelessMichal Hocko
Commit 5695be142e20 ("OOM, PM: OOM killed task shouldn't escape PM suspend") has left a race window when OOM killer manages to note_oom_kill after freeze_processes checks the counter. The race window is quite small and really unlikely and partial solution deemed sufficient at the time of submission. Tejun wasn't happy about this partial solution though and insisted on a full solution. That requires the full OOM and freezer's task freezing exclusion, though. This is done by this patch which introduces oom_sem RW lock and turns oom_killer_disable() into a full OOM barrier. oom_killer_disabled check is moved from the allocation path to the OOM level and we take oom_sem for reading for both the check and the whole OOM invocation. oom_killer_disable() takes oom_sem for writing so it waits for all currently running OOM killer invocations. Then it disable all the further OOMs by setting oom_killer_disabled and checks for any oom victims. Victims are counted via mark_tsk_oom_victim resp. unmark_oom_victim. The last victim wakes up all waiters enqueued by oom_killer_disable(). Therefore this function acts as the full OOM barrier. The page fault path is covered now as well although it was assumed to be safe before. As per Tejun, "We used to have freezing points deep in file system code which may be reacheable from page fault." so it would be better and more robust to not rely on freezing points here. Same applies to the memcg OOM killer. out_of_memory tells the caller whether the OOM was allowed to trigger and the callers are supposed to handle the situation. The page allocation path simply fails the allocation same as before. The page fault path will retry the fault (more on that later) and Sysrq OOM trigger will simply complain to the log. Normally there wouldn't be any unfrozen user tasks after try_to_freeze_tasks so the function will not block. But if there was an OOM killer racing with try_to_freeze_tasks and the OOM victim didn't finish yet then we have to wait for it. This should complete in a finite time, though, because - the victim cannot loop in the page fault handler (it would die on the way out from the exception) - it cannot loop in the page allocator because all the further allocation would fail and __GFP_NOFAIL allocations are not acceptable at this stage - it shouldn't be blocked on any locks held by frozen tasks (try_to_freeze expects lockless context) and kernel threads and work queues are not frozen yet Signed-off-by: Michal Hocko <mhocko@suse.cz> Suggested-by: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-11sysrq: convert printk to pr_* equivalentMichal Hocko
While touching this area let's convert printk to pr_*. This also makes the printing of continuation lines done properly. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06mm, oom: ensure memoryless node zonelist always includes zonesDavid Rientjes
With memoryless node support being worked on, it's possible that for optimizations that a node may not have a non-NULL zonelist. When CONFIG_NUMA is enabled and node 0 is memoryless, this means the zonelist for first_online_node may become NULL. The oom killer requires a zonelist that includes all memory zones for the sysrq trigger and pagefault out of memory handler. Ensure that a non-NULL zonelist is always passed to the oom killer. [akpm@linux-foundation.org: fix non-numa build] Signed-off-by: David Rientjes <rientjes@google.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06sysrq,rcu: suppress RCU stall warnings while sysrq runsRik van Riel
Some sysrq handlers can run for a long time, because they dump a lot of data onto a serial console. Having RCU stall warnings pop up in the middle of them only makes the problem worse. This patch temporarily disables RCU stall warnings while a sysrq request is handled. Signed-off-by: Rik van Riel <riel@redhat.com> Suggested-by: Paul McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Madper Xie <cxie@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Richard Weinberger <richard@nod.at> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06sysrq: rcu-ify __handle_sysrqRik van Riel
Echoing values into /proc/sysrq-trigger seems to be a popular way to get information out of the kernel. However, dumping information about thousands of processes, or hundreds of CPUs to serial console can result in IRQs being blocked for minutes, resulting in various kinds of cascade failures. The most common failure is due to interrupts being blocked for a very long time. This can lead to things like failed IO requests, and other things the system cannot easily recover from. This problem is easily fixable by making __handle_sysrq use RCU instead of spin_lock_irqsave. This leaves the warning that RCU grace periods have not elapsed for a long time, but the system will come back from that automatically. It also leaves sysrq-from-irq-context when the sysrq keys are pressed, but that is probably desired since people want that to work in situations where the system is already hosed. The callers of register_sysrq_key and unregister_sysrq_key appear to be capable of sleeping. Signed-off-by: Rik van Riel <riel@redhat.com> Reported-by: Madper Xie <cxie@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
2013-10-16sysrq: Allow magic SysRq key functions to be disabled through KconfigBen Hutchings
Turn the initial value of sysctl kernel.sysrq (SYSRQ_DEFAULT_ENABLE) into a Kconfig variable. Original version by Bastian Blank <waldi@debian.org>. Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-07Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input updates from Dmitry Torokhov: "A new driver for slidebar on Ideapad laptops and a bunch of assorted driver fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (32 commits) Input: add SYN_MAX and SYN_CNT constants Input: max11801_ts - convert to devm Input: egalax-ts - fix typo and improve text Input: MAINTAINERS - change maintainer for cyttsp driver Input: cyttsp4 - kill 'defined but not used' compiler warnings Input: add driver for slidebar on Lenovo IdeaPad laptops Input: omap-keypad - set up irq type from DT Input: omap-keypad - enable wakeup capability for keypad. Input: omap-keypad - clear interrupts on open Input: omap-keypad - convert to threaded IRQ Input: omap-keypad - use bitfiled instead of hardcoded values Input: cyttsp4 - remove useless NULL test from cyttsp4_watchdog_timer() Input: wacom - fix error return code in wacom_probe() Input: as5011 - fix error return code in as5011_probe() Input: keyboard, serio - simplify use of devm_ioremap_resource Input: tegra-kbc - simplify use of devm_ioremap_resource Input: htcpen - fix incorrect placement of __initdata Input: qt1070 - add power management ops Input: wistron_btns - add MODULE_DEVICE_TABLE Input: wistron_btns - mark the Medion MD96500 keymap as tested ...
2013-08-12Input: sysrq - DT binding for key sequenceMathieu J. Poirier
Adding a simple device tree binding for the specification of key sequences. Definition of the keys found in the sequence are located in 'include/uapi/linux/input.h'. For the sysrq driver, holding the sequence of keys down for a specific amount of time will reset the system. Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Acked-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2013-07-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input updates from Dmitry Torokhov: "First round of updates for the input subsystem. You will get a new touchsreen driver for Cypress 4th generation devices, a driver for a special controller implementing PS/2 protocol in OLPC devices, and a driver for power key for SiRFprimaII PWRC. HID and bcm5497 now support for the 2013 MacBook Air. EVIOCGKEY and the rest of evdev ioctls now flush events of matching type from the client's event queue so that clients can be sure any events received after issuing EVIOCG* ioctl are new events. And a host of cleanups and improvements in other drivers" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (87 commits) Input: cyttsp4 - kfree xfer_buf on error path in probe() Input: tps6507x-ts - select INPUT_POLLDEV Input: bcm5974 - add support for the 2013 MacBook Air HID: apple: Add support for the 2013 Macbook Air Input: cyttsp4 - leak on error path in probe() Input: cyttsp4 - silence NULL dereference warning Input: cyttsp4 - silence shift wrap warning Input: tps6507x-ts - convert to polled input device infrastructure ARM: davinci: da850-evm: remove vref from touchscreen platform data Input: cyttsp4 - SPI driver for Cypress TMA4XX touchscreen devices Input: cyttsp4 - I2C driver for Cypress TMA4XX touchscreen devices Input: cyttsp4 - add core driver for Cypress TMA4XX touchscreen devices Input: cyttsp - I2C driver split into two modules Input: add OLPC AP-SP driver Input: nspire-keypad - remove redundant dev_err call in nspire_keypad_probe() Input: tps6507x-ts - remove vref from platform data Input: tps6507x-ts - use bool for booleans Input: tps6507x-ts - remove bogus unreachable code Input: samsung-keypad - let device core setup the default pin configuration Input: wacom_i2c - implement hovering capability ...
2013-06-27Merge branch 'for-next' of git://github.com/rydberg/linux into nextDmitry Torokhov
Pull in changes from Henrik: "a trivial MT documentation fix".
2013-06-06Input: sysrq - request graceful shutdown for key resetMathieu J. Poirier
Attempt to reboot the system gracefully when a key combo is detected. If the reste combination is pressed the 2nd time we assume that graceful reboot failed and perform emergency reboot. This fucntionality is useful when UI is stuck but the system is otherwise working fine. Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2013-06-03tty: replace strict_strtoul() with kstrtoul()Jingoo Han
The usage of strict_strtoul() is not preferred, because strict_strtoul() is obsolete. Thus, kstrtoul() should be used. Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input updates from Dmitry Torokhov: "Assorted fixes and cleanups to the existing drivers plus a new driver for IMS Passenger Control Unit device they use for ther in-flight entertainment system." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (44 commits) Input: trackpoint - Optimize trackpoint init to use power-on reset Input: apbps2 - convert to devm_ioremap_resource() Input: ALPS - use %ph to print buffers ARM - shmobile: Armadillo800EVA: Move st1232 reset pin handling Input: st1232 - add reset pin handling Input: st1232 - convert to devm_* infrastructure Input: MT - handle semi-mt devices in core Input: adxl34x - use spi_get_drvdata() Input: ad7877 - use spi_get_drvdata() and spi_set_drvdata() Input: ads7846 - use spi_get_drvdata() and spi_set_drvdata() Input: ims-pcu - fix a memory leak on error Input: sysrq - supplement reset sequence with timeout functionality Input: tegra-kbc - support for defining row/columns based on SoC Input: imx_keypad - switch to using managed resources Input: arc_ps2 - add support for device tree Input: mma8450 - fix signed 12bits to 32bits conversion Input: eeti_ts - remove redundant null check Input: edt-ft5x06 - remove redundant null check before kfree Input: ad714x - add CONFIG_PM_SLEEP to suspend/resume functions Input: adxl34x - add CONFIG_PM_SLEEP to suspend/resume functions ...
2013-04-01Input: sysrq - supplement reset sequence with timeout functionalityMathieu J. Poirier
Some devices have too few buttons, which it makes it hard to have a reset combo that won't trigger automatically. As such a timeout functionality that requires the combination to be held for a given amount of time before triggering is introduced. If a key combo is recognized and held for a 'timeout' amount of time, the system triggers a reset. If the timeout value is omitted the driver simply ignores the functionality. Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2013-03-15sysrq: fix inconstistent help message of sysrq keyzhangwei(Jovi)
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 it. Thanks the comments from Andrew and Randy. Signed-off-by: zhangwei(Jovi) <jovi.zhangwei@huawei.com> Cc: Andrew Morton <akpm@linux-foundation.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-02-27sysrq: don't depend on weak undefined arrays to have an address that ↵Linus Torvalds
compares as NULL When taking an address of an extern array, gcc quite naturally should be able to say "an address of an object can never be NULL" and just optimize away the test entirely. However, the new alternate sysrq reset code (commit 154b7a489a5b: "Input: sysrq - allow specifying alternate reset sequence") did exactly that, and declared platform_sysrq_reset_seq[] as a weak array, and expecting that testing the address of the array would show whether it actually got linked against something or not. And that doesn't work with all gcc versions. Clearly it works with *some* versions of gcc, and maybe it's even supposed to work, but it really is a very fragile concept. So instead of testing the address of the weak variable, just create a weak instance of that array that is empty. If some platform then has a real platform_sysrq_reset_seq[] that overrides our weak one, the linker will switch to that one, and it all works without any run-time conditionals at all. Reported-by: Dave Airlie <airlied@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-20Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input updates from Dmitry Torokhov: "Two new touchpad drivers - Cypress APA I2C Trackpad and Cypress PS/2 touchpad and a big update to ALPS driver from Kevin Cernekee that adds support for "Rushmore" touchpads and paves way for adding support for "Dolphin" touchpads. There is also a new input driver for Goldfish emulator and also Android keyreset driver was folded into SysRq code. A few more drivers were updated with device tree bindings and others got some small cleanups and fixes." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (55 commits) Input: cyttsp-spi - remove duplicate MODULE_ALIAS() Input: tsc2005 - add MODULE_ALIAS Input: tegra-kbc - require CONFIG_OF, remove platform data Input: synaptics - initialize pointer emulation usage Input: MT - do not apply filtering on emulated events Input: bma150 - make some defines public and fix some comments Input: bma150 - fix checking pm_runtime_get_sync() return value Input: ALPS - enable trackstick on Rushmore touchpads Input: ALPS - add support for "Rushmore" touchpads Input: ALPS - make the V3 packet field decoder "pluggable" Input: ALPS - move pixel and bitmap info into alps_data struct Input: ALPS - fix command mode check Input: ALPS - rework detection of Pinnacle AGx touchpads Input: ALPS - move {addr,nibble}_command settings into alps_set_defaults() Input: ALPS - use function pointers for different protocol handlers Input: ALPS - rework detection sequence Input: ALPS - introduce helper function for repeated commands Input: ALPS - move alps_get_model() down below hw_init code Input: ALPS - copy "model" info into alps_data struct Input: ALPS - document the alps.h data structures ...
2013-02-07sched/rt: Move rt specific bits into new header fileClark Williams
Move rt scheduler definitions out of include/linux/sched.h into new file include/linux/sched/rt.h Signed-off-by: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20130207094707.7b9f825f@riff.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
2013-01-17Input: sysrq - allow specifying alternate reset sequenceMathieu Poirier
This patch adds keyreset functionality to the sysrq driver. It allows certain button/key combinations to be used in order to trigger emergency reboots. Redefining the '__weak platform_sysrq_reset_seq' variable is required to trigger the feature. Alternatively keys can be passed to the driver via a module parameter. This functionality comes from the keyreset driver submitted by Arve Hjønnevåg in the Android kernel. Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2012-11-15mm, oom: ensure sysrq+f always passes valid zonelistDavid Rientjes
With hotpluggable and memoryless nodes, it's possible that node 0 will not be online, so use the first online node's zonelist rather than hardcoding node 0 to pass a zonelist with all zones to the oom killer. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-16sparc64: Add global PMU register dumping via sysrq.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-05sysrq: use SEND_SIG_FORCED instead of force_sig()Anton Vorontsov
Change send_sig_all() to use do_send_sig_info(SEND_SIG_FORCED) instead of force_sig(SIGKILL). With the recent changes we do not need force_ to kill the CLONE_NEWPID tasks. And this is more correct. force_sig() can race with the exiting thread, while do_send_sig_info(group => true) kill the whole process. Some more notes from Oleg Nesterov: > Just one note. This change makes no difference for sysrq_handle_kill(). > But it obviously changes the behaviour sysrq_handle_term(). I think > this is fine, if you want to really kill the task which blocks/ignores > SIGTERM you can use sysrq_handle_kill(). > > Even ignoring the reasons why force_sig() is simply wrong here, > force_sig(SIGTERM) looks strange. The task won't be killed if it has > a handler, but SIG_IGN can't help. However if it has the handler > but blocks SIGTERM temporary (this is very common) it will be killed. Also, > force_sig() can't kill the process if the main thread has already > exited. IOW, it is trivial to create the process which can't be > killed by sysrq. So, this patch fixes the issue. Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-21mm, oom: force oom kill on sysrq+fDavid Rientjes
The oom killer chooses not to kill a thread if: - an eligible thread has already been oom killed and has yet to exit, and - an eligible thread is exiting but has yet to free all its memory and is not the thread attempting to currently allocate memory. SysRq+F manually invokes the global oom killer to kill a memory-hogging task. This is normally done as a last resort to free memory when no progress is being made or to test the oom killer itself. For both uses, we always want to kill a thread and never defer. This patch causes SysRq+F to always kill an eligible thread and can be used to force a kill even if another oom killed thread has failed to exit. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Pekka Enberg <penberg@kernel.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-08vt:tackle kbd_tableAlan Cox
Keyboard struct lifetime is easy, but the locking is not and is completely ignored by the existing code. Tackle this one head on - Make the kbd_table private so we can run down all direct users - Hoick the relevant ioctl handlers into the keyboard layer - Lock them with the keyboard lock so they don't change mid keypress - Add helpers for things like console stop/start so we isolate the poking around properly - Tweak the braille console so it still builds There are a couple of FIXME locking cases left for ioctls that are so hideous they should be addressed in a later patch. After this patch the kbd_table is private and all the keyboard jiggery pokery is in one place. This update fixes speakup and also a memory leak in the original. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-09sysrq: Properly check for kernel threadsAnton Vorontsov
There's a real possibility of killing kernel threads that might have issued use_mm(), so kthread's mm might become non-NULL. This patch fixes the issue by checking for PF_KTHREAD (just as get_task_mm()). Suggested-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-02-09sysrq: Fix possible race with exiting taskAnton Vorontsov
sysrq should grab the tasklist lock, otherwise calling force_sig() is not safe, as it might race with exiting task, which ->sighand might be set to NULL already. Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-03fs: move code out of buffer.cAl Viro
Move invalidate_bdev, block_sync_page into fs/block_dev.c. Export kill_bdev as well, so brd doesn't have to open code it. Reduce buffer_head.h requirement accordingly. Removed a rather large comment from invalidate_bdev, as it looked a bit obsolete to bother moving. The small comment replacing it says enough. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-24lib, arch: add filter argument to show_mem and fix private implementationsDavid Rientjes
Commit ddd588b5dd55 ("oom: suppress nodes that are not allowed from meminfo on oom kill") moved lib/show_mem.o out of lib/lib.a, which resulted in build warnings on all architectures that implement their own versions of show_mem(): lib/lib.a(show_mem.o): In function `show_mem': show_mem.c:(.text+0x1f4): multiple definition of `show_mem' arch/sparc/mm/built-in.o:(.text+0xd70): first defined here The fix is to remove __show_mem() and add its argument to show_mem() in all implementations to prevent this breakage. Architectures that implement their own show_mem() actually don't do anything with the argument yet, but they could be made to filter nodes that aren't allowed in the current context in the future just like the generic implementation. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-15Merge branch 'for-linus' of ↵Linus Torvalds
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: matrix_keypad - increase the limit of rows and columns Input: wacom - fix error path in wacom_probe() Input: ads7846 - check proper condition when freeing gpio Revert "Input: do not pass injected events back to the originating handler" Input: sysrq - rework re-inject logic Input: serio - clear pending rescans after sysfs driver rebind Input: rotary_encoder - use proper irqflags Input: wacom_w8001 - report resolution to userland
2011-01-26Merge branch 'for-linus' of ↵Linus Torvalds
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: wacom - pass touch resolution to clients through input_absinfo Input: wacom - add 2 Bamboo Pen and touch models Input: sysrq - ensure sysrq_enabled and __sysrq_enabled are consistent Input: sparse-keymap - fix KEY_VSW handling in sparse_keymap_setup Input: tegra-kbc - add tegra keyboard driver Input: gpio_keys - switch to using request_any_context_irq Input: serio - allow registered drivers to get status flag Input: ct82710c - return proper error code for ct82c710_open Input: bu21013_ts - added regulator support Input: bu21013_ts - remove duplicate resolution parameters Input: tnetv107x-ts - don't treat NULL clk as an error Input: tnetv107x-keypad - don't treat NULL clk as an error Fix up trivial conflicts in drivers/input/keyboard/Makefile due to additions of tc3589x/Tegra drivers
2010-11-19Merge branch 'for-linus' of ↵Linus Torvalds
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: fix typo in keycode validation supporting large scancodes Input: aiptek - tighten up permissions on sysfs attributes Input: sysrq - pass along lone Alt + SysRq
2010-11-05TTY: create drivers/tty and move the tty core files thereGreg Kroah-Hartman
The tty code should be in its own subdirectory and not in the char driver with all of the cruft that is currently there. Based on work done by Arnd Bergmann <arnd@arndb.de> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: Jiri Slaby <jslaby@suse.cz> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>