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2014-11-11module: Remove stop_machine from module unloadingMasami Hiramatsu
Remove stop_machine from module unloading by adding new reference counting algorithm. This atomic refcounter works like a semaphore, it can get (be incremented) only when the counter is not 0. When loading a module, kmodule subsystem sets the counter MODULE_REF_BASE (= 1). And when unloading the module, it subtracts MODULE_REF_BASE from the counter. If no one refers the module, the refcounter becomes 0 and we can remove the module safely. If someone referes it, we try to recover the counter by adding MODULE_REF_BASE unless the counter becomes 0, because the referrer can put the module right before recovering. If the recovering is failed, we can get the 0 refcount and it never be incremented again, it can be removed safely too. Note that __module_get() forcibly gets the module refcounter, users should use try_module_get() instead of that. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11module: Replace module_ref with atomic_t refcntMasami Hiramatsu
Replace module_ref per-cpu complex reference counter with an atomic_t simple refcnt. This is for code simplification. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11lib/bug: Use RCU list ops for module_bug_listMasami Hiramatsu
Actually since module_bug_list should be used in BUG context, we may not need this. But for someone who want to use this from normal context, this makes module_bug_list an RCU list. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11module: Unlink module with RCU synchronizing instead of stop_machineMasami Hiramatsu
Unlink module from module list with RCU synchronizing instead of using stop_machine(). Since module list is already protected by rcu, we don't need stop_machine() anymore. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-11module: Wait for RCU synchronizing before releasing a moduleMasami Hiramatsu
Wait for RCU synchronizing on failure path of module loading before releasing struct module, because the memory of mod->list can still be accessed by list walkers (e.g. kallsyms). Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-11-10tracing: Do not risk busy looping in buffer spliceRabin Vincent
If the read loop in trace_buffers_splice_read() keeps failing due to memory allocation failures without reading even a single page then this function will keep busy looping. Remove the risk for that by exiting the function if memory allocation failures are seen. Link: http://lkml.kernel.org/r/1415309167-2373-2-git-send-email-rabin@rab.in Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-10tracing: Do not busy wait in buffer spliceRabin Vincent
On a !PREEMPT kernel, attempting to use trace-cmd results in a soft lockup: # trace-cmd record -e raw_syscalls:* -F false NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [trace-cmd:61] ... Call Trace: [<ffffffff8105b580>] ? __wake_up_common+0x90/0x90 [<ffffffff81092e25>] wait_on_pipe+0x35/0x40 [<ffffffff810936e3>] tracing_buffers_splice_read+0x2e3/0x3c0 [<ffffffff81093300>] ? tracing_stats_read+0x2a0/0x2a0 [<ffffffff812d10ab>] ? _raw_spin_unlock+0x2b/0x40 [<ffffffff810dc87b>] ? do_read_fault+0x21b/0x290 [<ffffffff810de56a>] ? handle_mm_fault+0x2ba/0xbd0 [<ffffffff81095c80>] ? trace_event_buffer_lock_reserve+0x40/0x80 [<ffffffff810951e2>] ? trace_buffer_lock_reserve+0x22/0x60 [<ffffffff81095c80>] ? trace_event_buffer_lock_reserve+0x40/0x80 [<ffffffff8112415d>] do_splice_to+0x6d/0x90 [<ffffffff81126971>] SyS_splice+0x7c1/0x800 [<ffffffff812d1edd>] tracesys_phase2+0xd3/0xd8 The problem is this: tracing_buffers_splice_read() calls ring_buffer_wait() to wait for data in the ring buffers. The buffers are not empty so ring_buffer_wait() returns immediately. But tracing_buffers_splice_read() calls ring_buffer_read_page() with full=1, meaning it only wants to read a full page. When the full page is not available, tracing_buffers_splice_read() tries to wait again with ring_buffer_wait(), which again returns immediately, and so on. Fix this by adding a "full" argument to ring_buffer_wait() which will make ring_buffer_wait() wait until the writer has left the reader's page, i.e. until full-page reads will succeed. Link: http://lkml.kernel.org/r/1415645194-25379-1-git-send-email-rabin@rab.in Cc: stable@vger.kernel.org # 3.16+ Fixes: b1169cc69ba9 ("tracing: Remove mock up poll wait function") Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-10sched/numa: Fix out of bounds read in sched_init_numa()Andrey Ryabinin
On latest mm + KASan patchset I've got this: ================================================================== BUG: AddressSanitizer: out of bounds access in sched_init_smp+0x3ba/0x62c at addr ffff88006d4bee6c ============================================================================= BUG kmalloc-8 (Not tainted): kasan error ----------------------------------------------------------------------------- Disabling lock debugging due to kernel taint INFO: Allocated in alloc_vfsmnt+0xb0/0x2c0 age=75 cpu=0 pid=0 __slab_alloc+0x4b4/0x4f0 __kmalloc_track_caller+0x15f/0x1e0 kstrdup+0x44/0x90 alloc_vfsmnt+0xb0/0x2c0 vfs_kern_mount+0x35/0x190 kern_mount_data+0x25/0x50 pid_ns_prepare_proc+0x19/0x50 alloc_pid+0x5e2/0x630 copy_process.part.41+0xdf5/0x2aa0 do_fork+0xf5/0x460 kernel_thread+0x21/0x30 rest_init+0x1e/0x90 start_kernel+0x522/0x531 x86_64_start_reservations+0x2a/0x2c x86_64_start_kernel+0x15b/0x16a INFO: Slab 0xffffea0001b52f80 objects=24 used=22 fp=0xffff88006d4befc0 flags=0x100000000004080 INFO: Object 0xffff88006d4bed20 @offset=3360 fp=0xffff88006d4bee70 Bytes b4 ffff88006d4bed10: 00 00 00 00 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a ........ZZZZZZZZ Object ffff88006d4bed20: 70 72 6f 63 00 6b 6b a5 proc.kk. Redzone ffff88006d4bed28: cc cc cc cc cc cc cc cc ........ Padding ffff88006d4bee68: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B 3.18.0-rc3-mm1+ #108 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 ffff88006d4be000 0000000000000000 ffff88006d4bed20 ffff88006c86fd18 ffffffff81cd0a59 0000000000000058 ffff88006d404240 ffff88006c86fd48 ffffffff811fa3a8 ffff88006d404240 ffffea0001b52f80 ffff88006d4bed20 Call Trace: dump_stack (lib/dump_stack.c:52) print_trailer (mm/slub.c:645) object_err (mm/slub.c:652) ? sched_init_smp (kernel/sched/core.c:6552 kernel/sched/core.c:7063) kasan_report_error (mm/kasan/report.c:102 mm/kasan/report.c:178) ? kasan_poison_shadow (mm/kasan/kasan.c:48) ? kasan_unpoison_shadow (mm/kasan/kasan.c:54) ? kasan_poison_shadow (mm/kasan/kasan.c:48) ? kasan_kmalloc (mm/kasan/kasan.c:311) __asan_load4 (mm/kasan/kasan.c:371) ? sched_init_smp (kernel/sched/core.c:6552 kernel/sched/core.c:7063) sched_init_smp (kernel/sched/core.c:6552 kernel/sched/core.c:7063) kernel_init_freeable (init/main.c:869 init/main.c:997) ? finish_task_switch (kernel/sched/sched.h:1036 kernel/sched/core.c:2248) ? rest_init (init/main.c:924) kernel_init (init/main.c:929) ? rest_init (init/main.c:924) ret_from_fork (arch/x86/kernel/entry_64.S:348) ? rest_init (init/main.c:924) Read of size 4 by task swapper/0: Memory state around the buggy address: ffff88006d4beb80: fc fc fc fc fc fc fc fc fc fc 00 fc fc fc fc fc ffff88006d4bec00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88006d4bec80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88006d4bed00: fc fc fc fc 00 fc fc fc fc fc fc fc fc fc fc fc ffff88006d4bed80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88006d4bee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc 04 fc ^ ffff88006d4bee80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88006d4bef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88006d4bef80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff88006d4bf000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88006d4bf080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Zero 'level' (e.g. on non-NUMA system) causing out of bounds access in this line: sched_max_numa_distance = sched_domains_numa_distance[level - 1]; Fix this by exiting from sched_init_numa() earlier. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Reviewed-by: Rik van Riel <riel@redhat.com> Fixes: 9942f79ba ("sched/numa: Export info needed for NUMA balancing on complex topologies") Cc: peterz@infradead.org Link: http://lkml.kernel.org/r/1415372020-1871-1-git-send-email-a.ryabinin@samsung.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-09genirq: Generic chip: Add big endian I/O accessorsKevin Cernekee
Use io{read,write}32be if the caller specified IRQ_GC_BE_IO when creating the irqchip. Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://lkml.kernel.org/r/1415342669-30640-5-git-send-email-cernekee@gmail.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-11-09genirq: Generic chip: Change irq_reg_{readl,writel} argumentsKevin Cernekee
Pass in the irq_chip_generic struct so we can use different readl/writel settings for each irqchip driver, when appropriate. Compute (gc->reg_base + reg_offset) in the helper function because this is pretty much what all callers want to do anyway. Compile-tested using the following configurations: at91_dt_defconfig (CONFIG_ATMEL_AIC_IRQ=y) sama5_defconfig (CONFIG_ATMEL_AIC5_IRQ=y) sunxi_defconfig (CONFIG_ARCH_SUNXI=y) tb10x (ARC) is untested. Signed-off-by: Kevin Cernekee <cernekee@gmail.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Acked-by: Arnd Bergmann <arnd@arndb.de> Link: https://lkml.kernel.org/r/1415342669-30640-3-git-send-email-cernekee@gmail.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-11-08PM / sleep: Fix entering suspend-to-IDLE if no freeze_oops is setDmitry Eremin-Solenikov
If no freeze_ops is set, trying to enter suspend-to-IDLE will cause a nice oops in platform_suspend_prepare_late(). Add respective checks to platform_suspend_prepare_late() and platform_resume_early() functions. Fixes: a8d46b9e4e48 (ACPI / sleep: Rework the handling of ACPI GPE wakeup ...) Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-05tty: Move session_of_pgrp() and make staticPeter Hurley
tiocspgrp() is the lone caller of session_of_pgrp(); relocate and limit to file scope. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Reviewed-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-05pstore: Honor dmesg_restrict sysctl on dmesg dumpsSebastian Schmidt
When the kernel.dmesg_restrict restriction is in place, only users with CAP_SYSLOG should be able to access crash dumps (like: attacker is trying to exploit a bug, watchdog reboots, attacker can happily read crash dumps and logs). This puts the restriction on console-* types as well as sensitive information could have been leaked there. Other log types are unaffected. Signed-off-by: Sebastian Schmidt <yath@yath.de> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tony Luck <tony.luck@intel.com>
2014-11-04sched: Refactor task_struct to use numa_faults instead of numa_* pointersIulia Manda
This patch simplifies task_struct by removing the four numa_* pointers in the same array and replacing them with the array pointer. By doing this, on x86_64, the size of task_struct is reduced by 3 ulong pointers (24 bytes on x86_64). A new parameter is added to the task_faults_idx function so that it can return an index to the correct offset, corresponding with the old precalculated pointers. All of the code in sched/ that depended on task_faults_idx and numa_* was changed in order to match the new logic. Signed-off-by: Iulia Manda <iulia.manda21@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: mgorman@suse.de Cc: dave@stgolabs.net Cc: riel@redhat.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20141031001331.GA30662@winterfell Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched/deadline: Don't check CONFIG_SMP in switched_from_dl()Wanpeng Li
There are both UP and SMP version of pull_dl_task(), so don't need to check CONFIG_SMP in switched_from_dl(); Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-6-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched/deadline: Reschedule from switched_from_dl() after a successful pullWanpeng Li
In switched_from_dl() we have to issue a resched if we successfully pulled some task from other cpus. This patch also aligns the behavior with -rt. Suggested-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-5-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched/deadline: Push task away if the deadline is equal to curr during wakeupWanpeng Li
This patch pushes task away if the dealine of the task is equal to current during wake up. The same behavior as rt class. Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-4-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched/deadline: Add deadline rq status printWanpeng Li
This patch add deadline rq status print. Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-3-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched/deadline: Fix artificial overrun introduced by yield_task_dl()Wanpeng Li
The yield semantic of deadline class is to reduce remaining runtime to zero, and then update_curr_dl() will stop it. However, comsumed bandwidth is reduced from the budget of yield task again even if it has already been set to zero which leads to artificial overrun. This patch fix it by make sure we don't steal some more time from the task that yielded in update_curr_dl(). Suggested-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-2-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched/rt: Clean up check_preempt_equal_prio()Wanpeng Li
This patch checks if current can be pushed/pulled somewhere else in advance to make logic clear, the same behavior as dl class. - If current can't be migrated, useless to reschedule, let's hope task can move out. - If task is migratable, so let's not schedule it and see if it can be pushed or pulled somewhere else. Signed-off-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@arm.com> Cc: Kirill Tkhai <ktkhai@parallels.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414708776-124078-1-git-send-email-wanpeng.li@linux.intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched/core: Use dl_bw_of() under rcu_read_lock_sched()Juri Lelli
As per commit f10e00f4bf36 ("sched/dl: Use dl_bw_of() under rcu_read_lock_sched()"), dl_bw_of() has to be protected by rcu_read_lock_sched(). Signed-off-by: Juri Lelli <juri.lelli@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414497286-28824-1-git-send-email-juri.lelli@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched: Check if we got a shallowest_idle_cpu before searching for ↵Yao Dongdong
least_loaded_cpu Idle cpu is idler than non-idle cpu, so we needn't search for least_loaded_cpu after we have found an idle cpu. Signed-off-by: Yao Dongdong <yaodongdong@huawei.com> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414469286-6023-1-git-send-email-yaodongdong@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched/deadline: Implement cancel_dl_timer() to use in switched_from_dl()Kirill Tkhai
Currently used hrtimer_try_to_cancel() is racy: raw_spin_lock(&rq->lock) ... dl_task_timer raw_spin_lock(&rq->lock) ... raw_spin_lock(&rq->lock) ... switched_from_dl() ... ... hrtimer_try_to_cancel() ... ... switched_to_fair() ... ... ... ... ... ... ... ... raw_spin_unlock(&rq->lock) ... (asquired) ... ... ... ... ... ... do_exit() ... ... schedule() ... ... raw_spin_lock(&rq->lock) ... raw_spin_unlock(&rq->lock) ... ... ... raw_spin_unlock(&rq->lock) ... raw_spin_lock(&rq->lock) ... ... (asquired) put_task_struct() ... ... free_task_struct() ... ... ... ... raw_spin_unlock(&rq->lock) ... (asquired) ... ... ... ... ... (use after free) ... So, let's implement 100% guaranteed way to cancel the timer and let's be sure we are safe even in very unlikely situations. rq unlocking does not limit the area of switched_from_dl() use, because this has already been possible in pull_dl_task() below. Let's consider the safety of of this unlocking. New code in the patch is working when hrtimer_try_to_cancel() fails. This means the callback is running. In this case hrtimer_cancel() is just waiting till the callback is finished. Two 1) Since we are in switched_from_dl(), new class is not dl_sched_class and new prio is not less MAX_DL_PRIO. So, the callback returns early; it's right after !dl_task() check. After that hrtimer_cancel() returns back too. The above is: raw_spin_lock(rq->lock); ... ... dl_task_timer() ... raw_spin_lock(rq->lock); switched_from_dl() ... hrtimer_try_to_cancel() ... raw_spin_unlock(rq->lock); ... hrtimer_cancel() ... ... raw_spin_unlock(rq->lock); ... return HRTIMER_NORESTART; ... ... raw_spin_lock(rq->lock); ... 2) But the below is also possible: dl_task_timer() raw_spin_lock(rq->lock); ... raw_spin_unlock(rq->lock); raw_spin_lock(rq->lock); ... switched_from_dl() ... hrtimer_try_to_cancel() ... ... return HRTIMER_NORESTART; raw_spin_unlock(rq->lock); ... hrtimer_cancel(); ... raw_spin_lock(rq->lock); ... In this case hrtimer_cancel() returns immediately. Very unlikely case, just to mention. Nobody can manipulate the task, because check_class_changed() is always called with pi_lock locked. Nobody can force the task to participate in (concurrent) priority inheritance schemes (the same reason). All concurrent task operations require pi_lock, which is held by us. No deadlocks with dl_task_timer() are possible, because it returns right after !dl_task() check (it does nothing). If we receive a new dl_task during the time of unlocked rq, we just don't have to do pull_dl_task() in switched_from_dl() further. Signed-off-by: Kirill Tkhai <ktkhai@parallels.com> [ Added comments] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414420852.19914.186.camel@tkhai Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched: Use WARN_ONCE for the might_sleep() TASK_RUNNING testPeter Zijlstra
In some cases this can trigger a true flood of output. Requested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04audit, sched/wait: Fixup kauditd_thread() wait loopPeter Zijlstra
The kauditd_thread wait loop is a bit iffy; it has a number of problems: - calls try_to_freeze() before schedule(); you typically want the thread to re-evaluate the sleep condition when unfreezing, also freeze_task() issues a wakeup. - it unconditionally does the {add,remove}_wait_queue(), even when the sleep condition is false. Use wait_event_freezable() that does the right thing. Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Eric Paris <eparis@redhat.com> Cc: oleg@redhat.com Cc: Eric Paris <eparis@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20141002102251.GA6324@worktop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched/wait: Fix a kthread race with wait_woken()Peter Zijlstra
There is a race between kthread_stop() and the new wait_woken() that can result in a lack of progress. CPU 0 | CPU 1 | rfcomm_run() | kthread_stop() ... | if (!test_bit(KTHREAD_SHOULD_STOP)) | | set_bit(KTHREAD_SHOULD_STOP) | wake_up_process() wait_woken() | wait_for_completion() set_current_state(INTERRUPTIBLE) | if (!WQ_FLAG_WOKEN) | schedule_timeout() | | After which both tasks will wait.. forever. Fix this by having wait_woken() check for kthread_should_stop() but only for kthreads (obviously). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-04sched: Remove lockdep check in sched_move_task()Kirill Tkhai
sched_move_task() is the only interface to change sched_task_group: cpu_cgrp_subsys methods and autogroup_move_group() use it. Everything is synchronized by task_rq_lock(), so cpu_cgroup_attach() is ordered with other users of sched_move_task(). This means we do no need RCU here: if we've dereferenced a tg here, the .attach method hasn't been called for it yet. Thus, we should pass "true" to task_css_check() to silence lockdep warnings. Fixes: eeb61e53ea19 ("sched: Fix race between task_group and sched_task_group") Reported-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Kirill Tkhai <ktkhai@parallels.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1414473874.8574.2.camel@tkhai Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-11-03rcutorture: Fix rcu_torture_cbflood() memory leakPaul E. McKenney
Commit 38706bc5a29a (rcutorture: Add callback-flood test) vmalloc()ed a bunch of RCU callbacks, but failed to free them. This commit fixes that oversight. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03rcutorture: Add early boot self testsPranith Kumar
Add early boot self tests for RCU under CONFIG_PROVE_RCU. Currently the only test is adding a dummy callback which increments a counter which we then later verify after calling rcu_barrier*(). Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2014-11-03cpu: Avoid puts_pending overflowPaul E. McKenney
A long string of get_online_cpus() with each followed by a put_online_cpu() that fails to acquire cpu_hotplug.lock can result in overflow of the cpu_hotplug.puts_pending counter. Although this is perhaps improbably, a system with absolutely no CPU-hotplug operations will have an arbitrarily long time in which this overflow could occur. This commit therefore adds overflow checks to get_online_cpus() and try_get_online_cpus(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03rcu: Remove "cpu" argument to rcu_cleanup_after_idle()Paul E. McKenney
The "cpu" argument to rcu_cleanup_after_idle() is always the current CPU, so drop it. This moves the smp_processor_id() from the caller to rcu_cleanup_after_idle(), saving argument-passing overhead. Again, the anticipated cross-CPU uses of these functions has been replaced by NO_HZ_FULL. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03rcu: Remove "cpu" argument to rcu_prepare_for_idle()Paul E. McKenney
The "cpu" argument to rcu_prepare_for_idle() is always the current CPU, so drop it. This in turn allows two of the uses of "cpu" in this function to be replaced with a this_cpu_ptr() and the third by smp_processor_id(), replacing that of the call to rcu_prepare_for_idle(). Again, the anticipated cross-CPU uses of these functions has been replaced by NO_HZ_FULL. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03rcu: Remove "cpu" argument to rcu_needs_cpu()Paul E. McKenney
The "cpu" argument to rcu_needs_cpu() is always the current CPU, so drop it. This in turn allows the "cpu" argument to rcu_cpu_has_callbacks() to be removed, which allows the uses of "cpu" in both functions to be replaced with a this_cpu_ptr(). Again, the anticipated cross-CPU uses of these functions has been replaced by NO_HZ_FULL. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03rcu: Remove "cpu" argument to rcu_note_context_switch()Paul E. McKenney
The "cpu" argument to rcu_note_context_switch() is always the current CPU, so drop it. This in turn allows the "cpu" argument to rcu_preempt_note_context_switch() to be removed, which allows the sole use of "cpu" in both functions to be replaced with a this_cpu_ptr(). Again, the anticipated cross-CPU uses of these functions has been replaced by NO_HZ_FULL. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03rcu: Remove "cpu" argument to rcu_preempt_check_callbacks()Paul E. McKenney
Because rcu_preempt_check_callbacks()'s argument is guaranteed to always be the current CPU, drop the argument and replace per_cpu() with __this_cpu_read(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03rcu: Remove "cpu" argument to rcu_pending()Paul E. McKenney
Because rcu_pending()'s argument is guaranteed to always be the current CPU, drop the argument and replace per_cpu_ptr() with this_cpu_ptr(). Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03rcu: Remove "cpu" argument to rcu_check_callbacks()Paul E. McKenney
The "cpu" argument was kept around on the off-chance that RCU might offload scheduler-clock interrupts. However, this offload approach has been replaced by NO_HZ_FULL, which offloads -all- RCU processing from qualifying CPUs. It is therefore time to remove the "cpu" argument to rcu_check_callbacks(), which this commit does. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03rcu: Use DEFINE_PER_CPU_SHARED_ALIGNED for rcu_dataPaul E. McKenney
The rcu_data per-CPU variable has a number of fields that are atomically manipulated, potentially by any CPU. This situation can result in false sharing with per-CPU variables that have the misfortune of being allocated adjacent to rcu_data in memory. This commit therefore changes the DEFINE_PER_CPU() to DEFINE_PER_CPU_SHARED_ALIGNED() in order to avoid this false sharing. Reported-by: Christoph Lameter <cl@linux.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Christoph Lameter <cl@linux.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03rcu: Remove rcu_dynticks * parameters when they are always ↵Christoph Lameter
this_cpu_ptr(&rcu_dynticks) For some functions in kernel/rcu/tree* the rdtp parameter is always this_cpu_ptr(rdtp). Remove the parameter if constant and calculate the pointer in function. This will have the advantage that it is obvious that the address are all per cpu offsets and thus it will enable the use of this_cpu_ops in the future. Signed-off-by: Christoph Lameter <cl@linux.com> [ paulmck: Forward-ported to rcu/dev, whitespace adjustment. ] Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Pranith Kumar <bobby.prani@gmail.com>
2014-11-03move d_rcu from overlapping d_child to overlapping d_aliasAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-03PM / Hibernate: Migrate to ktime_tTina Ruchandani
This patch migrates swsusp_show_speed and its callers to using ktime_t instead of 'struct timeval' which suffers from the y2038 problem. Changes to swsusp_show_speed: - use ktime_t for start and stop times - pass start and stop times by value Calling functions affected: - load_image - load_image_lzo - save_image - save_image_lzo - hibernate_preallocate_memory Design decisions: - use ktime_t to preserve same granularity of reporting as before - use centisecs logic as before to avoid 'div by zero' issues caused by using seconds and nanoseconds directly - use monotonic time (ktime_get()) since we only care about elapsed time. Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com> Suggested-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: drivers/net/phy/marvell.c Simple overlapping changes in drivers/net/phy/marvell.c Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-31Merge tag 'pm+acpi-3.18-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management fixes from Rafael Wysocki: "These are fixes received after my previous pull request plus one that has been in the works for quite a while, but its previous version caused problems to happen, so it's been deferred till now. Fixed are two recent regressions (MFD enumeration and cpufreq-dt), ACPI EC regression introduced in 3.17, system suspend error code path regression introduced in 3.15, an older bug related to recovery from failing resume from hibernation and a cpufreq-dt driver issue related to operation performance points. Specifics: - Fix a crash on r8a7791/koelsch during resume from system suspend caused by a recent cpufreq-dt commit (Geert Uytterhoeven). - Fix an MFD enumeration problem introduced by a recent commit adding ACPI support to the MFD subsystem that exposed a weakness in the ACPI core causing ACPI enumeration to be applied to all devices associated with one ACPI companion object, although it should be used for one of them only (Mika Westerberg). - Fix an ACPI EC regression introduced during the 3.17 cycle causing some Samsung laptops to misbehave as a result of a workaround targeted at some Acer machines. That includes a revert of a commit that went too far and a quirk for the Acer machines in question. From Lv Zheng. - Fix a regression in the system suspend error code path introduced during the 3.15 cycle that causes it to fail to take errors from asychronous execution of "late" suspend callbacks into account (Imre Deak). - Fix a long-standing bug in the hibernation resume error code path that fails to roll back everything correcty on "freeze" callback errors and leaves some devices in a "suspended" state causing more breakage to happen subsequently (Imre Deak). - Make the cpufreq-dt driver disable operation performance points that are not supported by the VR connected to the CPU voltage plane with acceptable tolerance instead of constantly failing voltage scaling later on (Lucas Stach)" * tag 'pm+acpi-3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / EC: Fix regression due to conflicting firmware behavior between Samsung and Acer. Revert "ACPI / EC: Add support to disallow QR_EC to be issued before completing previous QR_EC" cpufreq: cpufreq-dt: Restore default cpumask_setall(policy->cpus) PM / Sleep: fix recovery during resuming from hibernation PM / Sleep: fix async suspend_late/freeze_late error handling ACPI: Use ACPI companion to match only the first physical device cpufreq: cpufreq-dt: disable unsupported OPPs
2014-10-31Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: "A bit has accumulated, but it's been a week or so since my last batch of post-merge-window fixes, so... 1) Missing module license in netfilter reject module, from Pablo. Lots of people ran into this. 2) Off by one in mac80211 baserate calculation, from Karl Beldan. 3) Fix incorrect return value from ax88179_178a driver's set_mac_addr op, which broke use of it with bonding. From Ian Morgan. 4) Checking of skb_gso_segment()'s return value was not all encompassing, it can return an SKB pointer, a pointer error, or NULL. Fix from Florian Westphal. This is crummy, and longer term will be fixed to just return error pointers or a real SKB. 6) Encapsulation offloads not being handled by skb_gso_transport_seglen(). From Florian Westphal. 7) Fix deadlock in TIPC stack, from Ying Xue. 8) Fix performance regression from using rhashtable for netlink sockets. The problem was the synchronize_net() invoked for every socket destroy. From Thomas Graf. 9) Fix bug in eBPF verifier, and remove the strong dependency of BPF on NET. From Alexei Starovoitov. 10) In qdisc_create(), use the correct interface to allocate ->cpu_bstats, otherwise the u64_stats_sync member isn't initialized properly. From Sabrina Dubroca. 11) Off by one in ip_set_nfnl_get_byindex(), from Dan Carpenter. 12) nf_tables_newchain() was erroneously expecting error pointers from netdev_alloc_pcpu_stats(). It only returna a valid pointer or NULL. From Sabrina Dubroca. 13) Fix use-after-free in _decode_session6(), from Li RongQing. 14) When we set the TX flow hash on a socket, we mistakenly do so before we've nailed down the final source port. Move the setting deeper to fix this. From Sathya Perla. 15) NAPI budget accounting in amd-xgbe driver was counting descriptors instead of full packets, fix from Thomas Lendacky. 16) Fix total_data_buflen calculation in hyperv driver, from Haiyang Zhang. 17) Fix bcma driver build with OF_ADDRESS disabled, from Hauke Mehrtens. 18) Fix mis-use of per-cpu memory in TCP md5 code. The problem is that something that ends up being vmalloc memory can't be passed to the crypto hash routines via scatter-gather lists. From Eric Dumazet. 19) Fix regression in promiscuous mode enabling in cdc-ether, from Olivier Blin. 20) Bucket eviction and frag entry killing can race with eachother, causing an unlink of the object from the wrong list. Fix from Nikolay Aleksandrov. 21) Missing initialization of spinlock in cxgb4 driver, from Anish Bhatt. 22) Do not cache ipv4 routing failures, otherwise if the sysctl for forwarding is subsequently enabled this won't be seen. From Nicolas Cavallari" * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (131 commits) drivers: net: cpsw: Support ALLMULTI and fix IFF_PROMISC in switch mode drivers: net: cpsw: Fix broken loop condition in switch mode net: ethtool: Return -EOPNOTSUPP if user space tries to read EEPROM with lengh 0 stmmac: pci: set default of the filter bins net: smc91x: Fix gpios for device tree based booting mpls: Allow mpls_gso to be built as module mpls: Fix mpls_gso handler. r8152: stop submitting intr for -EPROTO netfilter: nft_reject_bridge: restrict reject to prerouting and input netfilter: nft_reject_bridge: don't use IP stack to reject traffic netfilter: nf_reject_ipv6: split nf_send_reset6() in smaller functions netfilter: nf_reject_ipv4: split nf_send_reset() in smaller functions netfilter: nf_tables_bridge: update hook_mask to allow {pre,post}routing drivers/net: macvtap and tun depend on INET drivers/net, ipv6: Select IPv6 fragment idents for virtio UFO packets drivers/net: Disable UFO through virtio net: skb_fclone_busy() needs to detect orphaned skb gre: Use inner mac length when computing tunnel length mlx4: Avoid leaking steering rules on flow creation error flow net/mlx4_en: Don't attempt to TX offload the outer UDP checksum for VXLAN ...
2014-10-31Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Various scheduler fixes all over the place: three SCHED_DL fixes, three sched/numa fixes, two generic race fixes and a comment fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/dl: Fix preemption checks sched: Update comments for CLONE_NEWNS sched: stop the unbound recursion in preempt_schedule_context() sched/fair: Fix division by zero sysctl_numa_balancing_scan_size sched/fair: Care divide error in update_task_scan_period() sched/numa: Fix unsafe get_task_struct() in task_numa_assign() sched/deadline: Fix races between rt_mutex_setprio() and dl_task_timer() sched/deadline: Don't replenish from a !SCHED_DEADLINE entity sched: Fix race between task_group and sched_task_group
2014-10-31Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Mostly tooling fixes, plus on the kernel side: - a revert for a newly introduced PMU driver which isn't complete yet and where we ran out of time with fixes (to be tried again in v3.19) - this makes up for a large chunk of the diffstat. - compilation warning fixes - a printk message fix - event_idx usage fixes/cleanups" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf probe: Trivial typo fix for --demangle perf tools: Fix report -F dso_from for data without branch info perf tools: Fix report -F dso_to for data without branch info perf tools: Fix report -F symbol_from for data without branch info perf tools: Fix report -F symbol_to for data without branch info perf tools: Fix report -F mispredict for data without branch info perf tools: Fix report -F in_tx for data without branch info perf tools: Fix report -F abort for data without branch info perf tools: Make CPUINFO_PROC an array to support different kernel versions perf callchain: Use global caching provided by libunwind perf/x86/intel: Revert incomplete and undocumented Broadwell client support perf/x86: Fix compile warnings for intel_uncore perf: Fix typos in sample code in the perf_event.h header perf: Fix and clean up initialization of pmu::event_idx perf: Fix bogus kernel printk perf diff: Add missing hists__init() call at tool start
2014-10-31Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull futex fixes from Ingo Molnar: "This contains two futex fixes: one fixes a race condition, the other clarifies shared/private futex comments" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Fix a race condition between REQUEUE_PI and task death futex: Mention key referencing differences between shared and private futexes
2014-10-31Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core fixes from Ingo Molnar: "The tree contains two RCU fixes and a compiler quirk comment fix" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rcu: Make rcu_barrier() understand about missing rcuo kthreads compiler/gcc4+: Remove inaccurate comment about 'asm goto' miscompiles rcu: More on deadlock between CPU hotplug and expedited grace periods
2014-10-31Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "As you requested in the rc2 release mail the timer department serves you a few real bug fixes: - Fix the probe logic of the architected arm/arm64 timer - Plug a stack info leak in posix-timers - Prevent a shift out of bounds issue in the clockevents core" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: ARM/ARM64: arch-timer: fix arch_timer_probed logic clockevents: Prevent shift out of bounds posix-timers: Fix stack info leak in timer_create()
2014-10-31Merge tag 'trace-fixes-v3.18-rc1-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fix from Steven Rostedt: "ARM has system calls outside the NR_syscalls range, and the generic tracing system does not support that and without checks, it can cause an oops to be reported. Rabin Vincent added checks in the return code on syscall events to make sure that the system call number is within the range that tracing knows about, and if not, simply ignores the system call. The system call tracing infrastructure needs to be rewritten to handle these cases better, but for now, to keep from oopsing, this patch will do" * tag 'trace-fixes-v3.18-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing/syscalls: Ignore numbers outside NR_syscalls' range