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2019-01-29timekeeping/debug: No need to check return value of debugfs_create functionsGreg Kroah-Hartman
When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: John Stultz <john.stultz@linaro.org> Cc: Stephen Boyd <sboyd@kernel.org> Link: https://lkml.kernel.org/r/20190122152151.16139-43-gregkh@linuxfoundation.org
2018-12-11timekeeping: Convert to DEFINE_SHOW_ATTRIBUTEYangtao Li
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: john.stultz@linaro.org Cc: sboyd@kernel.org Link: https://lkml.kernel.org/r/20181211163744.22133-1-tiny.windzz@gmail.com
2018-11-23time/debug: Remove license boilerplateThomas Gleixner
The SPDX identifier is enough. Remove the license boilerplate. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Corey Minyard <cminyard@mvista.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Peter Anvin <hpa@zytor.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Richard Cochran <richardcochran@gmail.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: David Riley <davidriley@chromium.org> Cc: Colin Cross <ccross@android.com> Cc: Mark Brown <broonie@kernel.org> Link: https://lkml.kernel.org/r/20181031182253.047449481@linutronix.de
2018-11-23time: Add SPDX license identifiersThomas Gleixner
Update the time(r) core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Philippe Ombredanne, Kate Stewart and myself. The data has been created with two independent license scanners and manual inspection. The following files do not contain any direct license information and have been omitted from the big initial SPDX changes: timeconst.bc: The .bc files were not touched time.c, timer.c, timekeeping.c: Licence was deduced from EXPORT_SYMBOL_GPL As those files do not contain direct license references they fall under the project license, i.e. GPL V2 only. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: John Stultz <john.stultz@linaro.org> Acked-by: Corey Minyard <cminyard@mvista.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Russell King <rmk+kernel@armlinux.org.uk> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Nicolas Pitre <nicolas.pitre@linaro.org> Cc: David Riley <davidriley@chromium.org> Cc: Colin Cross <ccross@android.com> Cc: Mark Brown <broonie@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: https://lkml.kernel.org/r/20181031182252.879109557@linutronix.de
2018-07-19timekeeping/ntp: Constify some function argumentsOndrej Mosnacek
Add 'const' to some function arguments and variables to make it easier to read the code. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Stephen Boyd <sboyd@kernel.org> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> [jstultz: Also fixup pre-existing checkpatch warnings for prototype arguments with no variable name] Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-07-23PM / timekeeping: Print debug messages when requestedRafael J. Wysocki
The messages printed by tk_debug_account_sleep_time() are basically useful for system sleep debugging, so print them only when the other debug messages from the core suspend/hibernate code are enabled. While at it, make it clear that the messages from tk_debug_account_sleep_time() are about timekeeping suspend duration, because in general timekeeping may be suspeded and resumed for multiple times during one system suspend-resume cycle. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-02-15timekeeping: Use deferred printk() in debug codeSergey Senozhatsky
We cannot do printk() from tk_debug_account_sleep_time(), because tk_debug_account_sleep_time() is called under tk_core seq lock. The reason why printk() is unsafe there is that console_sem may invoke scheduler (up()->wake_up_process()->activate_task()), which, in turn, can return back to timekeeping code, for instance, via get_time()->ktime_get(), deadlocking the system on tk_core seq lock. [ 48.950592] ====================================================== [ 48.950622] [ INFO: possible circular locking dependency detected ] [ 48.950622] 4.10.0-rc7-next-20170213+ #101 Not tainted [ 48.950622] ------------------------------------------------------- [ 48.950622] kworker/0:0/3 is trying to acquire lock: [ 48.950653] (tk_core){----..}, at: [<c01cc624>] retrigger_next_event+0x4c/0x90 [ 48.950683] but task is already holding lock: [ 48.950683] (hrtimer_bases.lock){-.-...}, at: [<c01cc610>] retrigger_next_event+0x38/0x90 [ 48.950714] which lock already depends on the new lock. [ 48.950714] the existing dependency chain (in reverse order) is: [ 48.950714] -> #5 (hrtimer_bases.lock){-.-...}: [ 48.950744] _raw_spin_lock_irqsave+0x50/0x64 [ 48.950775] lock_hrtimer_base+0x28/0x58 [ 48.950775] hrtimer_start_range_ns+0x20/0x5c8 [ 48.950775] __enqueue_rt_entity+0x320/0x360 [ 48.950805] enqueue_rt_entity+0x2c/0x44 [ 48.950805] enqueue_task_rt+0x24/0x94 [ 48.950836] ttwu_do_activate+0x54/0xc0 [ 48.950836] try_to_wake_up+0x248/0x5c8 [ 48.950836] __setup_irq+0x420/0x5f0 [ 48.950836] request_threaded_irq+0xdc/0x184 [ 48.950866] devm_request_threaded_irq+0x58/0xa4 [ 48.950866] omap_i2c_probe+0x530/0x6a0 [ 48.950897] platform_drv_probe+0x50/0xb0 [ 48.950897] driver_probe_device+0x1f8/0x2cc [ 48.950897] __driver_attach+0xc0/0xc4 [ 48.950927] bus_for_each_dev+0x6c/0xa0 [ 48.950927] bus_add_driver+0x100/0x210 [ 48.950927] driver_register+0x78/0xf4 [ 48.950958] do_one_initcall+0x3c/0x16c [ 48.950958] kernel_init_freeable+0x20c/0x2d8 [ 48.950958] kernel_init+0x8/0x110 [ 48.950988] ret_from_fork+0x14/0x24 [ 48.950988] -> #4 (&rt_b->rt_runtime_lock){-.-...}: [ 48.951019] _raw_spin_lock+0x40/0x50 [ 48.951019] rq_offline_rt+0x9c/0x2bc [ 48.951019] set_rq_offline.part.2+0x2c/0x58 [ 48.951049] rq_attach_root+0x134/0x144 [ 48.951049] cpu_attach_domain+0x18c/0x6f4 [ 48.951049] build_sched_domains+0xba4/0xd80 [ 48.951080] sched_init_smp+0x68/0x10c [ 48.951080] kernel_init_freeable+0x160/0x2d8 [ 48.951080] kernel_init+0x8/0x110 [ 48.951080] ret_from_fork+0x14/0x24 [ 48.951110] -> #3 (&rq->lock){-.-.-.}: [ 48.951110] _raw_spin_lock+0x40/0x50 [ 48.951141] task_fork_fair+0x30/0x124 [ 48.951141] sched_fork+0x194/0x2e0 [ 48.951141] copy_process.part.5+0x448/0x1a20 [ 48.951171] _do_fork+0x98/0x7e8 [ 48.951171] kernel_thread+0x2c/0x34 [ 48.951171] rest_init+0x1c/0x18c [ 48.951202] start_kernel+0x35c/0x3d4 [ 48.951202] 0x8000807c [ 48.951202] -> #2 (&p->pi_lock){-.-.-.}: [ 48.951232] _raw_spin_lock_irqsave+0x50/0x64 [ 48.951232] try_to_wake_up+0x30/0x5c8 [ 48.951232] up+0x4c/0x60 [ 48.951263] __up_console_sem+0x2c/0x58 [ 48.951263] console_unlock+0x3b4/0x650 [ 48.951263] vprintk_emit+0x270/0x474 [ 48.951293] vprintk_default+0x20/0x28 [ 48.951293] printk+0x20/0x30 [ 48.951324] kauditd_hold_skb+0x94/0xb8 [ 48.951324] kauditd_thread+0x1a4/0x56c [ 48.951324] kthread+0x104/0x148 [ 48.951354] ret_from_fork+0x14/0x24 [ 48.951354] -> #1 ((console_sem).lock){-.....}: [ 48.951385] _raw_spin_lock_irqsave+0x50/0x64 [ 48.951385] down_trylock+0xc/0x2c [ 48.951385] __down_trylock_console_sem+0x24/0x80 [ 48.951385] console_trylock+0x10/0x8c [ 48.951416] vprintk_emit+0x264/0x474 [ 48.951416] vprintk_default+0x20/0x28 [ 48.951416] printk+0x20/0x30 [ 48.951446] tk_debug_account_sleep_time+0x5c/0x70 [ 48.951446] __timekeeping_inject_sleeptime.constprop.3+0x170/0x1a0 [ 48.951446] timekeeping_resume+0x218/0x23c [ 48.951477] syscore_resume+0x94/0x42c [ 48.951477] suspend_enter+0x554/0x9b4 [ 48.951477] suspend_devices_and_enter+0xd8/0x4b4 [ 48.951507] enter_state+0x934/0xbd4 [ 48.951507] pm_suspend+0x14/0x70 [ 48.951507] state_store+0x68/0xc8 [ 48.951538] kernfs_fop_write+0xf4/0x1f8 [ 48.951538] __vfs_write+0x1c/0x114 [ 48.951538] vfs_write+0xa0/0x168 [ 48.951568] SyS_write+0x3c/0x90 [ 48.951568] __sys_trace_return+0x0/0x10 [ 48.951568] -> #0 (tk_core){----..}: [ 48.951599] lock_acquire+0xe0/0x294 [ 48.951599] ktime_get_update_offsets_now+0x5c/0x1d4 [ 48.951629] retrigger_next_event+0x4c/0x90 [ 48.951629] on_each_cpu+0x40/0x7c [ 48.951629] clock_was_set_work+0x14/0x20 [ 48.951660] process_one_work+0x2b4/0x808 [ 48.951660] worker_thread+0x3c/0x550 [ 48.951660] kthread+0x104/0x148 [ 48.951690] ret_from_fork+0x14/0x24 [ 48.951690] other info that might help us debug this: [ 48.951690] Chain exists of: tk_core --> &rt_b->rt_runtime_lock --> hrtimer_bases.lock [ 48.951721] Possible unsafe locking scenario: [ 48.951721] CPU0 CPU1 [ 48.951721] ---- ---- [ 48.951721] lock(hrtimer_bases.lock); [ 48.951751] lock(&rt_b->rt_runtime_lock); [ 48.951751] lock(hrtimer_bases.lock); [ 48.951751] lock(tk_core); [ 48.951782] *** DEADLOCK *** [ 48.951782] 3 locks held by kworker/0:0/3: [ 48.951782] #0: ("events"){.+.+.+}, at: [<c0156590>] process_one_work+0x1f8/0x808 [ 48.951812] #1: (hrtimer_work){+.+...}, at: [<c0156590>] process_one_work+0x1f8/0x808 [ 48.951843] #2: (hrtimer_bases.lock){-.-...}, at: [<c01cc610>] retrigger_next_event+0x38/0x90 [ 48.951843] stack backtrace: [ 48.951873] CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.10.0-rc7-next-20170213+ [ 48.951904] Workqueue: events clock_was_set_work [ 48.951904] [<c0110208>] (unwind_backtrace) from [<c010c224>] (show_stack+0x10/0x14) [ 48.951934] [<c010c224>] (show_stack) from [<c04ca6c0>] (dump_stack+0xac/0xe0) [ 48.951934] [<c04ca6c0>] (dump_stack) from [<c019b5cc>] (print_circular_bug+0x1d0/0x308) [ 48.951965] [<c019b5cc>] (print_circular_bug) from [<c019d2a8>] (validate_chain+0xf50/0x1324) [ 48.951965] [<c019d2a8>] (validate_chain) from [<c019ec18>] (__lock_acquire+0x468/0x7e8) [ 48.951995] [<c019ec18>] (__lock_acquire) from [<c019f634>] (lock_acquire+0xe0/0x294) [ 48.951995] [<c019f634>] (lock_acquire) from [<c01d0ea0>] (ktime_get_update_offsets_now+0x5c/0x1d4) [ 48.952026] [<c01d0ea0>] (ktime_get_update_offsets_now) from [<c01cc624>] (retrigger_next_event+0x4c/0x90) [ 48.952026] [<c01cc624>] (retrigger_next_event) from [<c01e4e24>] (on_each_cpu+0x40/0x7c) [ 48.952056] [<c01e4e24>] (on_each_cpu) from [<c01cafc4>] (clock_was_set_work+0x14/0x20) [ 48.952056] [<c01cafc4>] (clock_was_set_work) from [<c015664c>] (process_one_work+0x2b4/0x808) [ 48.952087] [<c015664c>] (process_one_work) from [<c0157774>] (worker_thread+0x3c/0x550) [ 48.952087] [<c0157774>] (worker_thread) from [<c015d644>] (kthread+0x104/0x148) [ 48.952087] [<c015d644>] (kthread) from [<c0107830>] (ret_from_fork+0x14/0x24) Replace printk() with printk_deferred(), which does not call into the scheduler. Fixes: 0bf43f15db85 ("timekeeping: Prints the amounts of time spent during suspend") Reported-and-tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J . Wysocki" <rjw@rjwysocki.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: John Stultz <john.stultz@linaro.org> Cc: "[4.9+]" <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20170215044332.30449-1-sergey.senozhatsky@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-08-31timekeeping: Prints the amounts of time spent during suspendRuchi Kandoi
In addition to keeping a histogram of suspend times, also print out the time spent in suspend to dmesg. This helps to keep track of suspend time while debugging using kernel logs. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com> [jstultz: Tweaked commit message] Signed-off-by: John Stultz <john.stultz@linaro.org>
2016-08-24timekeeping: Cap array access in timekeeping_debugJohn Stultz
It was reported that hibernation could fail on the 2nd attempt, where the system hangs at hibernate() -> syscore_resume() -> i8237A_resume() -> claim_dma_lock(), because the lock has already been taken. However there is actually no other process would like to grab this lock on that problematic platform. Further investigation showed that the problem is triggered by setting /sys/power/pm_trace to 1 before the 1st hibernation. Since once pm_trace is enabled, the rtc becomes unmeaningful after suspend, and meanwhile some BIOSes would like to adjust the 'invalid' RTC (e.g, smaller than 1970) to the release date of that motherboard during POST stage, thus after resumed, it may seem that the system had a significant long sleep time which is a completely meaningless value. Then in timekeeping_resume -> tk_debug_account_sleep_time, if the bit31 of the sleep time happened to be set to 1, fls() returns 32 and we add 1 to sleep_time_bin[32], which causes an out of bounds array access and therefor memory being overwritten. As depicted by System.map: 0xffffffff81c9d080 b sleep_time_bin 0xffffffff81c9d100 B dma_spin_lock the dma_spin_lock.val is set to 1, which caused this problem. This patch adds a sanity check in tk_debug_account_sleep_time() to ensure we don't index past the sleep_time_bin array. [jstultz: Problem diagnosed and original patch by Chen Yu, I've solved the issue slightly differently, but borrowed his excelent explanation of the issue here.] Fixes: 5c83545f24ab "power: Add option to log time spent in suspend" Reported-by: Janek Kozicki <cosurgi@gmail.com> Reported-by: Chen Yu <yu.c.chen@intel.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: linux-pm@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Xunlei Pang <xpang@redhat.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: stable <stable@vger.kernel.org> Cc: Zhang Rui <rui.zhang@intel.com> Link: http://lkml.kernel.org/r/1471993702-29148-3-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-07-23timekeeping: Convert timekeeping core to use timespec64sJohn Stultz
Convert the core timekeeping logic to use timespec64s. This moves the 2038 issues out of the core logic and into all of the accessor functions. Future changes will need to push the timespec64s out to all timekeeping users, but that can be done interface by interface. Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Stultz <john.stultz@linaro.org>
2014-03-02kernel: Include appropriate header file in time/timekeeping_debug.cRashika Kheria
Include appropriate header file kernel/time/timekeeping_internal.h in kernel/time/timekeeping_debug.c because it has prototype declaration of function defined in kernel/time/timekeeping_debug.c. This eliminates the following warning in kernel/time/timekeeping_debug.c: kernel/time/timekeeping_debug.c:68:6: warning: no previous prototype for ‘tk_debug_account_sleep_time’ [-Wmissing-prototypes] Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-05-29power: Add option to log time spent in suspendColin Cross
Below is a patch from android kernel that maintains a histogram of suspend times. Please review and provide feedback. Statistices on the time spent in suspend are kept in /sys/kernel/debug/sleep_time. Cc: Android Kernel Team <kernel-team@android.com> Cc: Colin Cross <ccross@android.com> Cc: Todd Poynor <toddpoynor@google.com> Cc: San Mehat <san@google.com> Cc: Benoit Goby <benoit@android.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Colin Cross <ccross@android.com> Signed-off-by: Todd Poynor <toddpoynor@google.com> [zoran.markovic@linaro.org: Re-formatted suspend time table to better fit expected values. Moved accounting of suspend time into timekeeping core. Removed CONFIG_SUSPEND_TIME flag and made the feature conditional on CONFIG_DEBUG_FS. Changed the file name to sleep_time to better fit terminology in timekeeping core. Changed seq_printf to seq_puts. Tweaked commit message] Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>