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path: root/drivers/tty/sysrq.c
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2013-02-27sysrq: don't depend on weak undefined arrays to have an address that ↵Linus Torvalds1-8/+7
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 Torvalds1-74/+202
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 Williams1-0/+1
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 Poirier1-74/+202
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>
2012-11-16mm, oom: ensure sysrq+f always passes valid zonelistDavid Rientjes1-1/+2
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. Miller1-0/+1
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-06sysrq: use SEND_SIG_FORCED instead of force_sig()Anton Vorontsov1-1/+1
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>
2012-03-22mm, oom: force oom kill on sysrq+fDavid Rientjes1-1/+1
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 Cox1-4/+2
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 Vorontsov1-3/+6
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 Vorontsov1-0/+2
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>
2012-01-04fs: move code out of buffer.cAl Viro1-1/+1
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>
2011-03-25lib, arch: add filter argument to show_mem and fix private implementationsDavid Rientjes1-1/+1
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 Torvalds1-1/+16
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 Torvalds1-1/+1
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 Torvalds1-45/+124
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-Hartman1-0/+811
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>