user/sven/linux.git/kernel/timer.c, branch v3.4.78

timer: Fix jiffies wrap behavior of round_jiffies_common()

2013-07-22T01:19:01Z

commit 9e04d3804d3ac97d8c03a41d78d0f0674b5d01e1 upstream. Direct compare of jiffies related values does not work in the wrap around case. Replace it with time_is_after_jiffies(). Signed-off-by: Bart Van Assche Cc: Arjan van de Ven Cc: Stephen Rothwell Link: http://lkml.kernel.org/r/519BC066.5080600@acm.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

timer: Don't reinitialize the cpu base lock during CPU_UP_PREPARE

2013-05-19T17:54:39Z

commit 42a5cf46cd56f46267d2a9fcf2655f4078cd3042 upstream. An inactive timer's base can refer to a offline cpu's base. In the current code, cpu_base's lock is blindly reinitialized each time a CPU is brought up. If a CPU is brought online during the period that another thread is trying to modify an inactive timer on that CPU with holding its timer base lock, then the lock will be reinitialized under its feet. This leads to following SPIN_BUG(). <0> BUG: spinlock already unlocked on CPU#3, kworker/u:3/1466 <0> lock: 0xe3ebe000, .magic: dead4ead, .owner: kworker/u:3/1466, .owner_cpu: 1 <4> [] (unwind_backtrace+0x0/0x11c) from [] (do_raw_spin_unlock+0x40/0xcc) <4> [] (do_raw_spin_unlock+0x40/0xcc) from [] (_raw_spin_unlock+0x8/0x30) <4> [] (_raw_spin_unlock+0x8/0x30) from [] (mod_timer+0x294/0x310) <4> [] (mod_timer+0x294/0x310) from [] (queue_delayed_work_on+0x104/0x120) <4> [] (queue_delayed_work_on+0x104/0x120) from [] (sdhci_msm_bus_voting+0x88/0x9c) <4> [] (sdhci_msm_bus_voting+0x88/0x9c) from [] (sdhci_disable+0x40/0x48) <4> [] (sdhci_disable+0x40/0x48) from [] (mmc_release_host+0x4c/0xb0) <4> [] (mmc_release_host+0x4c/0xb0) from [] (mmc_sd_detect+0x90/0xfc) <4> [] (mmc_sd_detect+0x90/0xfc) from [] (mmc_rescan+0x7c/0x2c4) <4> [] (mmc_rescan+0x7c/0x2c4) from [] (process_one_work+0x27c/0x484) <4> [] (process_one_work+0x27c/0x484) from [] (worker_thread+0x210/0x3b0) <4> [] (worker_thread+0x210/0x3b0) from [] (kthread+0x80/0x8c) <4> [] (kthread+0x80/0x8c) from [] (kernel_thread_exit+0x0/0x8) As an example, this particular crash occurred when CPU #3 is executing mod_timer() on an inactive timer whose base is refered to offlined CPU #2. The code locked the timer_base corresponding to CPU #2. Before it could proceed, CPU #2 came online and reinitialized the spinlock corresponding to its base. Thus now CPU #3 held a lock which was reinitialized. When CPU #3 finally ended up unlocking the old cpu_base corresponding to CPU #2, we hit the above SPIN_BUG(). CPU #0 CPU #3 CPU #2 ------ ------- ------- ..... ...... mod_timer() lock_timer_base spin_lock_irqsave(&base->lock) cpu_up(2) ..... ...... init_timers_cpu() .... ..... spin_lock_init(&base->lock) ..... spin_unlock_irqrestore(&base->lock) ...... Allocation of per_cpu timer vector bases is done only once under "tvec_base_done[]" check. In the current code, spinlock_initialization of base->lock isn't under this check. When a CPU is up each time the base lock is reinitialized. Move base spinlock initialization under the check. Signed-off-by: Tirupathi Reddy Link: http://lkml.kernel.org/r/1368520142-4136-1-git-send-email-tirupath@codeaurora.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

timers: Fix endless looping between cascade() and internal_add_timer()

2012-10-21T16:27:59Z

commit 26cff4e2aa4d666dc6a120ea34336b5057e3e187 upstream. Adding two (or more) timers with large values for "expires" (they have to reside within tv5 in the same list) leads to endless looping between cascade() and internal_add_timer() in case CONFIG_BASE_SMALL is one and jiffies are crossing the value 1 << 18. The bug was introduced between 2.6.11 and 2.6.12 (and survived for quite some time). This patch ensures that when cascade() is called timers within tv5 are not added endlessly to their own list again, instead they are added to the next lower tv level tv4 (as expected). Signed-off-by: Christian Hildner Reviewed-by: Jan Kiszka Link: http://lkml.kernel.org/r/98673C87CB31274881CFFE0B65ECC87B0F5FC1963E@DEFTHW99EA4MSX.ww902.siemens.net Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

Merge branch 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2012-01-06T15:53:34Z

* 'core-debugobjects-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timer: Use debugobjects to catch deletion of uninitialized timers timer: Setup uninitialized timer with a stub callback debugobjects: Extend to assert that an object is initialized debugobjects: Be smarter about static objects

sys_getppid: add missing rcu_dereference

2011-12-09T15:50:29Z

In order to safely dereference current->real_parent inside an rcu_read_lock, we need an rcu_dereference. Signed-off-by: Mandeep Singh Baines Cc: Thomas Gleixner Cc: Pavel Emelyanov Cc: Oleg Nesterov Cc: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

timer: Use debugobjects to catch deletion of uninitialized timers

2011-11-23T17:49:23Z

del_timer_sync() calls debug_object_assert_init() to assert that a timer has been initialized before calling lock_timer_base(). lock_timer_base() would spin forever on a NULL(uninit-ed) base. The check is added to del_timer() to prevent silent failure, even though it would not get stuck in an infinite loop. [ sboyd@codeaurora.org: Remove WARN, intialize timer function] Signed-off-by: Christine Chan Signed-off-by: Stephen Boyd Cc: John Stultz Link: http://lkml.kernel.org/r/1320724108-20788-4-git-send-email-sboyd@codeaurora.org Signed-off-by: Andrew Morton Signed-off-by: Thomas Gleixner

timer: Setup uninitialized timer with a stub callback

2011-11-23T17:49:23Z

Remove the WARN_ON() in timer_fixup_activate() as we now get the debugobjects printout in the debugobjects activate check. We also assign a dummy timer callback so that if the timer is actually set to fire we don't oops. [ tglx@linutronix.de: Split out the debugobjects vs. the timer change ] Signed-off-by: Stephen Boyd Cc: Christine Chan Cc: John Stultz Signed-off-by: Andrew Morton Link: http://lkml.kernel.org/r/1320724108-20788-2-git-send-email-sboyd@codeaurora.org Signed-off-by: Thomas Gleixner

kernel: Map most files to use export.h instead of module.h

2011-10-31T13:20:12Z

The changed files were only including linux/module.h for the EXPORT_SYMBOL infrastructure, and nothing else. Revector them onto the isolated export header for faster compile times. Nothing to see here but a whole lot of instances of: -#include +#include This commit is only changing the kernel dir; next targets will probably be mm, fs, the arch dirs, etc. Signed-off-by: Paul Gortmaker

timers: Consider slack value in mod_timer()

2011-06-03T13:02:32Z

There is an optimization which does not update the timer if the timer was pending and the expiration time was unchanged. Since commit 3bbb9ec9 ("timers: Introduce the concept of timer slack for legacy timers") this optimization is no longer applied for timers where the expiration time got extended due to the slack value. So we need to check again after the expiration time might have been updated. [ tglx: Made it a single check by applying slack first and sorting out the slack = 0 value (all timeouts < 256 jiffies) early ] Signed-off-by: Sebastian Andrzej Siewior Link: http://lkml.kernel.org/r/20110521105828.GA29442@Chamillionaire.breakpoint.cc Signed-off-by: Thomas Gleixner

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2011-03-16T01:53:35Z

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (62 commits) posix-clocks: Check write permissions in posix syscalls hrtimer: Remove empty hrtimer_init_hres_timer() hrtimer: Update hrtimer->state documentation hrtimer: Update base[CLOCK_BOOTTIME].offset correctly timers: Export CLOCK_BOOTTIME via the posix timers interface timers: Add CLOCK_BOOTTIME hrtimer base time: Extend get_xtime_and_monotonic_offset() to also return sleep time: Introduce get_monotonic_boottime and ktime_get_boottime hrtimers: extend hrtimer base code to handle more then 2 clockids ntp: Remove redundant and incorrect parameter check mn10300: Switch do_timer() to xtimer_update() posix clocks: Introduce dynamic clocks posix-timers: Cleanup namespace posix-timers: Add support for fd based clocks x86: Add clock_adjtime for x86 posix-timers: Introduce a syscall for clock tuning. time: Splitout compat timex accessors ntp: Add ADJ_SETOFFSET mode bit time: Introduce timekeeping_inject_offset posix-timer: Update comment ... Fix up new system-call-related conflicts in arch/x86/ia32/ia32entry.S arch/x86/include/asm/unistd_32.h arch/x86/include/asm/unistd_64.h arch/x86/kernel/syscall_table_32.S (name_to_handle_at()/open_by_handle_at() vs clock_adjtime()), and some due to movement of get_jiffies_64() in: kernel/time.c