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* alarmtimer: Get rid of unused return valueThomas Gleixner2015-04-221-7/+4
| | | | | | | | | | | | | | | We want to get rid of the hrtimer_start() return value and the alarm timer return value is nowhere used. Remove it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20150414203503.243910615@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* hrtimer: Get rid of hrtimer_get_res()Thomas Gleixner2015-04-221-3/+3
| | | | | | | | | | | | | | | | | | The resolution is directly accessible now. So its simpler just to fill in the values of the timespec and be done with it. Text size reduction (combined with "hrtimer: Get rid of the resolution field in hrtimer_clock_base"): x8664 -61, i386 -221, ARM -60, power64 -48 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: http://lkml.kernel.org/r/20150414203500.879888080@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* all arches, signal: move restart_block to struct task_structAndy Lutomirski2015-02-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If an attacker can cause a controlled kernel stack overflow, overwriting the restart block is a very juicy exploit target. This is because the restart_block is held in the same memory allocation as the kernel stack. Moving the restart block to struct task_struct prevents this exploit by making the restart_block harder to locate. Note that there are other fields in thread_info that are also easy targets, at least on some architectures. It's also a decent simplification, since the restart code is more or less identical on all architectures. [james.hogan@imgtec.com: metag: align thread_info::supervisor_stack] Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: David Miller <davem@davemloft.net> Acked-by: Richard Weinberger <richard@nod.at> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Haavard Skinnemoen <hskinnemoen@gmail.com> Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no> Cc: Steven Miao <realmz6@gmail.com> Cc: Mark Salter <msalter@redhat.com> Cc: Aurelien Jacquiot <a-jacquiot@ti.com> Cc: Mikael Starvik <starvik@axis.com> Cc: Jesper Nilsson <jesper.nilsson@axis.com> Cc: David Howells <dhowells@redhat.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Michal Simek <monstr@monstr.eu> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Lennox Wu <lennox.wu@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Chris Zankel <chris@zankel.net> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: James Hogan <james.hogan@imgtec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* alarmtimer: Lock k_itimer during timer callbackRichard Larocque2014-09-121-2/+8
| | | | | | | | | | | | | | | | | | | Locks the k_itimer's it_lock member when handling the alarm timer's expiry callback. The regular posix timers defined in posix-timers.c have this lock held during timout processing because their callbacks are routed through posix_timer_fn(). The alarm timers follow a different path, so they ought to grab the lock somewhere else. Cc: stable@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Signed-off-by: Richard Larocque <rlarocque@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimer: Do not signal SIGEV_NONE timersRichard Larocque2014-09-121-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | Avoids sending a signal to alarm timers created with sigev_notify set to SIGEV_NONE by checking for that special case in the timeout callback. The regular posix timers avoid sending signals to SIGEV_NONE timers by not scheduling any callbacks for them in the first place. Although it would be possible to do something similar for alarm timers, it's simpler to handle this as a special case in the timeout. Prior to this patch, the alarm timer would ignore the sigev_notify value and try to deliver signals to the process anyway. Even worse, the sanity check for the value of sigev_signo is skipped when SIGEV_NONE was specified, so the signal number could be bogus. If sigev_signo was an unitialized value (as it often would be if SIGEV_NONE is used), then it's hard to predict which signal will be sent. Cc: stable@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Signed-off-by: Richard Larocque <rlarocque@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimer: Return relative times in timer_gettimeRichard Larocque2014-09-121-7/+11
| | | | | | | | | | | | | | | | | | | | | | Returns the time remaining for an alarm timer, rather than the time at which it is scheduled to expire. If the timer has already expired or it is not currently scheduled, the it_value's members are set to zero. This new behavior matches that of the other posix-timers and the POSIX specifications. This is a change in user-visible behavior, and may break existing applications. Hopefully, few users rely on the old incorrect behavior. Cc: stable@vger.kernel.org Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Signed-off-by: Richard Larocque <rlarocque@google.com> [jstultz: minor style tweak] Signed-off-by: John Stultz <john.stultz@linaro.org>
* Merge tag 'staging-3.17-rc1' of ↵Linus Torvalds2014-08-041-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging driver updates from Greg KH: "Here's the big pull request for the staging driver tree for 3.17-rc1. Lots of things in here, over 2000 patches, but the best part is this: 1480 files changed, 39070 insertions(+), 254659 deletions(-) Thanks to the great work of Kristina Martšenko, 14 different staging drivers have been removed from the tree as they were obsolete and no one was willing to work on cleaning them up. Other than the driver removals, loads of cleanups are in here (comedi, lustre, etc.) as well as the usual IIO driver updates and additions. All of this has been in the linux-next tree for a while" * tag 'staging-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (2199 commits) staging: comedi: addi_apci_1564: remove diagnostic interrupt support code staging: comedi: addi_apci_1564: add subdevice to check diagnostic status staging: wlan-ng: coding style problem fix staging: wlan-ng: fixing coding style problems staging: comedi: ii_pci20kc: request and ioremap memory staging: lustre: bitwise vs logical typo staging: dgnc: Remove unneeded dgnc_trace.c and dgnc_trace.h staging: dgnc: rephrase comment staging: comedi: ni_tio: remove some dead code staging: rtl8723au: Fix static symbol sparse warning staging: rtl8723au: usb_dvobj_init(): Remove unused variable 'pdev_desc' staging: rtl8723au: Do not duplicate kernel provided USB macros staging: rtl8723au: Remove never set struct pwrctrl_priv.bHWPowerdown staging: rtl8723au: Remove two never set variables staging: rtl8723au: RSSI_test is never set staging:r8190: coding style: Fixed checkpatch reported Error staging:r8180: coding style: Fixed too long lines staging:r8180: coding style: Fixed commenting style staging: lustre: ptlrpc: lproc_ptlrpc.c - fix dereferenceing user space buffer staging: lustre: ldlm: ldlm_resource.c - fix dereferenceing user space buffer ...
| * alarmtimer: Export symbols of alarmtimer_get_rtcdevPramod Gurav2014-06-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | Export symbol of alarmtimer_get_rtcdev so that it is used by any driver when built as module like, drivers/staging/android/alarm-dev.c. CC: John Stultz <john.stultz@linaro.org> CC: Marcus Gelderie <redmnic@gmail.com> Signed-off-by: Pramod Gurav <pramod.gurav.etc@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | alarmtimer: Fix bug where relative alarm timers were treated as absoluteJohn Stultz2014-07-081-2/+18
|/ | | | | | | | | | | | | | | | | | | | Sharvil noticed with the posix timer_settime interface, using the CLOCK_REALTIME_ALARM or CLOCK_BOOTTIME_ALARM clockid, if the users tried to specify a relative time timer, it would incorrectly be treated as absolute regardless of the state of the flags argument. This patch corrects this, properly checking the absolute/relative flag, as well as adds further error checking that no invalid flag bits are set. Reported-by: Sharvil Nanavati <sharvil@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Cc: stable <stable@vger.kernel.org> #3.0+ Link: http://lkml.kernel.org/r/1404767171-6902-1-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* alarmtimer: return EINVAL instead of ENOTSUPP if rtcdev doesn't existKOSAKI Motohiro2013-10-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fedora Ruby maintainer reported latest Ruby doesn't work on Fedora Rawhide on ARM. (http://bugs.ruby-lang.org/issues/9008) Because of, commit 1c6b39ad3f (alarmtimers: Return -ENOTSUPP if no RTC device is present) intruduced to return ENOTSUPP when clock_get{time,res} can't find a RTC device. However this is incorrect. First, ENOTSUPP isn't exported to userland (ENOTSUP or EOPNOTSUP are the closest userland equivlents). Second, Posix and Linux man pages agree that clock_gettime and clock_getres should return EINVAL if clk_id argument is invalid. While the arugment that the clockid is valid, but just not supported on this hardware could be made, this is just a technicality that doesn't help userspace applicaitons, and only complicates error handling. Thus, this patch changes the code to use EINVAL. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: stable <stable@vger.kernel.org> #3.0 and up Reported-by: Vit Ondruch <v.ondruch@tiscali.cz> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> [jstultz: Tweaks to commit message to include full rational] Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimer: Export symbols of functions declared in linux/alarmtimer.hMarcus Gelderie2013-06-121-1/+9
| | | | | | | | | | | Export symbols so they can be used by drivers/staging/android/alarm-dev.c if it is built as a module. So far alarm-dev is built-in but module support is planned (see drivers/staging/android/TODO). Signed-off-by: Marcus Gelderie <redmnic@gmail.com> [jstultz: tweaked commit message, also export newly added functions] Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimer: Add functions for timerfd supportTodd Poynor2013-05-291-1/+38
| | | | | | | | | | | | | | | | | | | Add functions needed for hooking up alarmtimer to timerfd: * alarm_restart: Similar to hrtimer_restart, restart an alarmtimer after the expires time has already been updated (as with alarm_forward). * alarm_forward_now: Similar to hrtimer_forward_now, move the expires time forward to an interval from the current time of the associated clock. * alarm_start_relative: Start an alarmtimer with an expires time relative to the current time of the associated clock. * alarm_expires_remaining: Similar to hrtimer_expires_remaining, return the amount of time remaining until alarm expiry. Signed-off-by: Todd Poynor <toddpoynor@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimer: Rename alarmtimer_remove to alarmtimer_dequeueJohn Stultz2012-09-241-4/+4
| | | | | | | | | | | Now that alarmtimer_remove has been simplified, change its name to _dequeue to better match its paired _enqueue function. Cc: Arve Hjønnevåg <arve@android.com> Cc: Colin Cross <ccross@android.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimer: Use hrtimer per-alarm instead of per-baseJohn Stultz2012-09-241-67/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Arve Hjønnevåg reported numerous crashes from the "BUG_ON(timer->state != HRTIMER_STATE_CALLBACK)" check in __run_hrtimer after it called alarmtimer_fired. It ends up the alarmtimer code was not properly handling possible failures of hrtimer_try_to_cancel, and because these faulres occur when the underlying base hrtimer is being run, this limits the ability to properly handle modifications to any alarmtimers on that base. Because much of the logic duplicates the hrtimer logic, it seems that we might as well have a per-alarmtimer hrtimer, and avoid the extra complextity of trying to multiplex many alarmtimers off of one hrtimer. Thus this patch moves the hrtimer to the alarm structure and simplifies the management logic. Changelog: v2: * Includes a fix for double alarm_start calls found by Arve Cc: Arve Hjønnevåg <arve@android.com> Cc: Colin Cross <ccross@android.com> Cc: Thomas Gleixner <tglx@linutronix.de> Reported-by: Arve Hjønnevåg <arve@android.com> Tested-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimer: Implement minimum alarm interval for allowing suspendTodd Poynor2012-09-241-5/+13
| | | | | | | | | | | | | | | | | | | alarmtimer suspend return -EBUSY if the next alarm will fire in less than 2 seconds. This allows one RTC seconds tick to occur subsequent to this check before the alarm wakeup time is set, ensuring the wakeup time is still in the future (assuming the RTC does not tick one more second prior to setting the alarm). If suspend is rejected due to an imminent alarm, hold a wakeup source for 2 seconds to process the alarm prior to reattempting suspend. If setting the alarm incurs an -ETIME for an alarm set in the past, or any other problem setting the alarm, abort suspend and hold a wakelock for 1 second while the alarm is allowed to be serviced or other hopefully transient conditions preventing the alarm clear up. Signed-off-by: Todd Poynor <toddpoynor@google.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimer: Provide accessor to alarmtimer rtc deviceJohn Stultz2012-04-201-2/+2
| | | | | | | | | | | | | | The Android alarm interface provides a settime call that sets both the alarmtimer RTC device and CLOCK_REALTIME to the same value. Since there may be multiple rtc devices, provide a hook to access the one the alarmtimer infrastructure is using. CC: Colin Cross <ccross@android.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Android Kernel Team <kernel-team@android.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* alarmtimer: Don't call rtc_timer_init() when CONFIG_RTC_CLASS=nThomas Gleixner2012-03-241-3/+8
| | | | | | | | | rtc_timer_init() is not available when CONFIG_RTC_CLASS=n. Provide a proper wrapper in the RTC section of alarmtimer.c Reported-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org>
* alarmtimer: Make sure we initialize the rtctimerJohn Stultz2012-03-231-1/+4
| | | | | | | | | | | jonghwan Choi reported seeing warnings with the alarmtimer code at suspend/resume time, and pointed out that the rtctimer isn't being properly initialized. This patch corrects this issue. Reported-by: jonghwan Choi <jhbird.choi@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Fix time comparisonThomas Gleixner2011-12-061-1/+1
| | | | | | | | | | | | The expiry function compares the timer against current time and does not expire the timer when the expiry time is >= now. That's wrong. If the timer is set for now, then it must expire. Make the condition expiry > now for breaking out the loop. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: John Stultz <john.stultz@linaro.org> Cc: stable@kernel.org
* alarmtimers: Fix error handlingThomas Gleixner2011-09-141-10/+31
| | | | | | | commit 8bc0daf (alarmtimers: Rework RTC device selection using class interface) did not implement required error checks. Add them. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* alarmtimers: Rework RTC device selection using class interfaceJohn Stultz2011-08-101-38/+40
| | | | | | | | This allows cleaner detection of the RTC device being registered, rather then probing any time someone calls alarmtimer_get_rtcdev. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Add try_to_cancel functionalityJohn Stultz2011-08-101-6/+37
| | | | | | | | | | There's a number of edge cases when cancelling a alarm, so to be sure we accurately do so, introduce try_to_cancel, which returns proper failure errors if it cannot. Also modify cancel to spin until the alarm is properly disabled. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Add more refined alarm state trackingJohn Stultz2011-08-101-7/+14
| | | | | | | | In order to allow for functionality like try_to_cancel, add more refined state tracking (similar to hrtimers). CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Remove period from alarm structureJohn Stultz2011-08-101-16/+14
| | | | | | | | | Now that periodic alarmtimers are managed by the handler function, remove the period value from the alarm structure and let the handlers manage the interval on their own. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Remove interval cap limit hackJohn Stultz2011-08-101-9/+0
| | | | | | | | Now that the alarmtimers code has been refactored, the interval cap limit can be removed. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Add alarm_forward functionalityJohn Stultz2011-08-101-1/+36
| | | | | | | | | | In order to avoid wasting time expiring and re-adding very high freq periodic alarmtimers, introduce alarm_forward() which is similar to hrtimer_forward and moves the timer to the next future expiration time and returns the number of overruns. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Push rearming peroidic timers down into alamrtimer handlerJohn Stultz2011-08-101-7/+13
| | | | | | | | This patch pushes the periodic alarmtimer re-arming down into the alarmtimer handler, mimicking how hrtimers handle this. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Change alarmtimer functions to return alarmtimer_restart valuesJohn Stultz2011-08-101-4/+9
| | | | | | | | | | | | | | In order to properly fix the denial of service issue with high freq periodic alarm timers, we need to push the re-arming logic into the alarm timer handler, much as the hrtimer code does. This patch introduces alarmtimer_restart enum and changes the alarmtimer handler declarations to use it as a return value. Further, to ease following changes, it extends the alarmtimer handler functions to also take the time at expiration. No logic is yet modified. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Avoid possible denial of service with high freq periodic timersJohn Stultz2011-08-101-0/+9
| | | | | | | | | | | | | Its possible to jam up the alarm timers by setting very small interval timers, which will cause the alarmtimer subsystem to spend all of its time firing and restarting timers. This can effectivly lock up a box. A deeper fix is needed, closely mimicking the hrtimer code, but for now just cap the interval to 100us to avoid userland hanging the system. CC: Thomas Gleixner <tglx@linutronix.de> CC: stable@kernel.org Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Memset itimerspec passed into alarm_timer_getJohn Stultz2011-08-101-0/+2
| | | | | | | | Following common_timer_get, zero out the itimerspec passed in. CC: Thomas Gleixner <tglx@linutronix.de> CC: stable@kernel.org Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Avoid possible null pointer traversalJohn Stultz2011-08-101-5/+2
| | | | | | | | | We don't check if old_setting is non null before assigning it, so correct this. CC: Thomas Gleixner <tglx@linutronix.de> CC: stable@kernel.org Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Return -ENOTSUPP if no RTC device is presentJohn Stultz2011-06-211-1/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Toralf Förster and Richard Weinberger noted that if there is no RTC device, the alarm timers core prints out an annoying "ALARM timers will not wake from suspend" message. This warning has been removed in a previous patch, however the issue still remains: The original idea was to support alarm timers even if there was no rtc device, as long as the system didn't go into suspend. However, after further consideration, communicating to the application that alarmtimers are not fully functional seems like the better solution. So this patch makes it so we return -ENOTSUPP to any posix _ALARM clockid calls if there is no backing RTC device on the system. Further this changes the behavior where when there is no rtc device we will check for one on clock_getres, clock_gettime, timer_create, and timer_nsleep instead of on suspend. CC: Toralf Förster <toralf.foerster@gmx.de> CC: Richard Weinberger <richard@nod.at CC: Peter Zijlstra <peterz@infradead.org> CC: Thomas Gleixner <tglx@linutronix.de> Reported-by: Toralf Förster <toralf.foerster@gmx.de> Reported by: Richard Weinberger <richard@nod.at> Signed-off-by: John Stultz <john.stultz@linaro.org>
* alarmtimers: Handle late rtc module loadingJohn Stultz2011-06-211-70/+67
| | | | | | | | | | | | | | | | The alarmtimers code currently picks a rtc device to use at late init time. However, if your rtc driver is loaded as a module, it may be registered after the alarmtimers late init code, leaving the alarmtimers nonfunctional. This patch moves the the rtcdevice selection to when we actually try to use it, allowing us to make use of rtc modules that may have been loaded at any point since bootup. CC: Thomas Gleixner <tglx@linutronix.de> CC: Meelis Roos <mroos@ut.ee> Reported-by: Meelis Roos <mroos@ut.ee> Signed-off-by: John Stultz <john.stultz@linaro.org>
* hrtimers: Avoid touching inactive timer basesThomas Gleixner2011-05-231-2/+2
| | | | | | | | Instead of iterating over all possible timer bases avoid it by marking the active bases in the cpu base. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Peter Zijlstra <peterz@infradead.org>
* alarmtimer: Drop device refcount after rtc_open()Thomas Gleixner2011-05-041-1/+7
| | | | | | | | class_find_device() takes a refcount on the rtc device. rtc_open() takes another one, so we can drop it after the rtc_open() call. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org>
* alarmtimer: Check return value of class_find_device()Thomas Gleixner2011-05-041-2/+4
| | | | | | | | | | | | | | | | | | | alarmtimer_late_init() uses class_find_device() to find a alarm capable rtc device. The match callback stores a pointer to the name in the char pointer handed in from the call site. alarmtimer_late_init() checks the char pointer for NULL, but the pointer is on the stack and not initialized to NULL before the call. So it can have random content when the match function did not identify a device, which leads to random access in the following rtc_open() call where the pointer is dereferenced Instead of relying on the char pointer, check the return value of class_find_device. If a device is found then the name pointer is valid as well. Reported-by: Ingo Molnar <mingo@elte.hu> Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* timers: Fix alarmtimer build issues when CONFIG_RTC_CLASS=nJohn Stultz2011-05-021-2/+18
| | | | | | | | | | Ingo pointed out that the alarmtimers won't build if CONFIG_RTC_CLASS=n. This patch adds proper ifdefs to the alarmtimer code to disable the rtc usage if it is not built in. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* timers: Remove delayed irqwork from alarmtimers implementationJohn Stultz2011-04-281-23/+9
| | | | | | | | | | | | | | | Thomas asked about the delayed irq work in the alarmtimers code, and I realized that it was a legacy from when the alarmtimer base lock was a mutex (due to concerns that we'd be interacting with the RTC device, which is protected by mutexes). Since the alarmtimer base is now protected by a spinlock, we can simply execute alarmtimer functions directly from the hrtimer callback. Should any future alarmtimer functions sleep, they can simply manage scheduling any delayed work themselves. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* timers: Improve alarmtimer comments and minor fixesJohn Stultz2011-04-281-40/+27
| | | | | | | | This patch addresses a number of minor comment improvements and other minor issues from Thomas' review of the alarmtimers code. CC: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* timers: Posix interface for alarm-timersJohn Stultz2011-04-261-0/+330
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch exposes alarm-timers to userland via the posix clock and timers interface, using two new clockids: CLOCK_REALTIME_ALARM and CLOCK_BOOTTIME_ALARM. Both clockids behave identically to CLOCK_REALTIME and CLOCK_BOOTTIME, respectively, but timers set against the _ALARM suffixed clockids will wake the system if it is suspended. Some background can be found here: https://lwn.net/Articles/429925/ The concept for Alarm-timers was inspired by the Android Alarm driver (by Arve Hjønnevåg) found in the Android kernel tree. See: http://android.git.kernel.org/?p=kernel/common.git;a=blob;f=drivers/rtc/alarm.c;h=1250edfbdf3302f5e4ea6194847c6ef4bb7beb1c;hb=android-2.6.36 While the in-kernel interface is pretty similar between alarm-timers and Android alarm driver, the user-space interface for the Android alarm driver is via ioctls to a new char device. As mentioned above, I've instead chosen to export this functionality via the posix interface, as it seemed a little simpler and avoids creating duplicate interfaces to things like CLOCK_REALTIME and CLOCK_MONOTONIC under alternate names (ie:ANDROID_ALARM_RTC and ANDROID_ALARM_SYSTEMTIME). The semantics of the Android alarm driver are different from what this posix interface provides. For instance, threads other then the thread waiting on the Android alarm driver are able to modify the alarm being waited on. Also this interface does not allow the same wakelock semantics that the Android driver provides (ie: kernel takes a wakelock on RTC alarm-interupt, and holds it through process wakeup, and while the process runs, until the process either closes the char device or calls back in to wait on a new alarm). One potential way to implement similar semantics may be via the timerfd infrastructure, but this needs more research. There may also need to be some sort of sysfs system level policy hooks that allow alarm timers to be disabled to keep them from firing at inappropriate times (ie: laptop in a well insulated bag, mid-flight). CC: Arve Hjønnevåg <arve@android.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
* timers: Introduce in-kernel alarm-timer interfaceJohn Stultz2011-04-261-0/+375
This provides the in kernel interface and infrastructure for alarm-timers. Alarm-timers are a hybrid style timer, similar to hrtimers, but when the system is suspended, the RTC device is set to fire and wake the system for when the soonest alarm-timer expires. The concept for Alarm-timers was inspired by the Android Alarm driver (by Arve Hjønnevåg) found in the Android kernel tree. See: http://android.git.kernel.org/?p=kernel/common.git;a=blob;f=drivers/rtc/alarm.c;h=1250edfbdf3302f5e4ea6194847c6ef4bb7beb1c;hb=android-2.6.36 This in-kernel interface should be fairly compatible with the Android alarm driver in-kernel interface, but has the advantage of utilizing the new RTC timerqueue code instead of doing direct RTC manipulation. CC: Arve Hjønnevåg <arve@android.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-17 09:22:58 +0000