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2014-06-02Merge tag 'pci-v3.16-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into next Pull PCI changes from Bjorn Helgaas: "Enumeration - Notify driver before and after device reset (Keith Busch) - Use reset notification in NVMe (Keith Busch) NUMA - Warn if we have to guess host bridge node information (Myron Stowe) - Work around AMD Fam15h BIOSes that fail to provide _PXM (Suravee Suthikulpanit) - Clean up and mark early_root_info_init() as deprecated (Suravee Suthikulpanit) Driver binding - Add "driver_override" for force specific binding (Alex Williamson) - Fail "new_id" addition for devices we already know about (Bandan Das) Resource management - Support BAR sizes up to 8GB (Nikhil Rao, Alan Cox) - Don't move IORESOURCE_PCI_FIXED resources (Bjorn Helgaas) - Mark SBx00 HPET BAR as IORESOURCE_PCI_FIXED (Bjorn Helgaas) - Fail safely if we can't handle BARs larger than 4GB (Bjorn Helgaas) - Reject BAR above 4GB if dma_addr_t is too small (Bjorn Helgaas) - Don't convert BAR address to resource if dma_addr_t is too small (Bjorn Helgaas) - Don't set BAR to zero if dma_addr_t is too small (Bjorn Helgaas) - Don't print anything while decoding is disabled (Bjorn Helgaas) - Don't add disabled subtractive decode bus resources (Bjorn Helgaas) - Add resource allocation comments (Bjorn Helgaas) - Restrict 64-bit prefetchable bridge windows to 64-bit resources (Yinghai Lu) - Assign i82875p_edac PCI resources before adding device (Yinghai Lu) PCI device hotplug - Remove unnecessary "dev->bus" test (Bjorn Helgaas) - Use PCI_EXP_SLTCAP_PSN define (Bjorn Helgaas) - Fix rphahp endianess issues (Laurent Dufour) - Acknowledge spurious "cmd completed" event (Rajat Jain) - Allow hotplug service drivers to operate in polling mode (Rajat Jain) - Fix cpqphp possible NULL dereference (Rickard Strandqvist) MSI - Replace pci_enable_msi_block() by pci_enable_msi_exact() (Alexander Gordeev) - Replace pci_enable_msix() by pci_enable_msix_exact() (Alexander Gordeev) - Simplify populate_msi_sysfs() (Jan Beulich) Virtualization - Add Intel Patsburg (X79) root port ACS quirk (Alex Williamson) - Mark RTL8110SC INTx masking as broken (Alex Williamson) Generic host bridge driver - Add generic PCI host controller driver (Will Deacon) Freescale i.MX6 - Use new clock names (Lucas Stach) - Drop old IRQ mapping (Lucas Stach) - Remove optional (and unused) IRQs (Lucas Stach) - Add support for MSI (Lucas Stach) - Fix imx6_add_pcie_port() section mismatch warning (Sachin Kamat) Renesas R-Car - Add gen2 device tree support (Ben Dooks) - Use new OF interrupt mapping when possible (Lucas Stach) - Add PCIe driver (Phil Edworthy) - Add PCIe MSI support (Phil Edworthy) - Add PCIe device tree bindings (Phil Edworthy) Samsung Exynos - Remove unnecessary OOM messages (Jingoo Han) - Fix add_pcie_port() section mismatch warning (Sachin Kamat) Synopsys DesignWare - Make MSI ISR shared IRQ aware (Lucas Stach) Miscellaneous - Check for broken config space aliasing (Alex Williamson) - Update email address (Ben Hutchings) - Fix Broadcom CNB20LE unintended sign extension (Bjorn Helgaas) - Fix incorrect vgaarb conditional in WARN_ON() (Bjorn Helgaas) - Remove unnecessary __ref annotations (Bjorn Helgaas) - Add arch/x86/kernel/quirks.c to MAINTAINERS PCI file patterns (Bjorn Helgaas) - Fix use of uninitialized MPS value (Bjorn Helgaas) - Tidy x86/gart messages (Bjorn Helgaas) - Fix return value from pci_user_{read,write}_config_*() (Gavin Shan) - Turn pcibios_penalize_isa_irq() into a weak function (Hanjun Guo) - Remove unused serial device IDs (Jean Delvare) - Use designated initialization in PCI_VDEVICE (Mark Rustad) - Fix powerpc NULL dereference in pci_root_buses traversal (Mike Qiu) - Configure MPS on ARM (Murali Karicheri) - Remove unnecessary includes of <linux/init.h> (Paul Gortmaker) - Move Open Firmware devspec attribute to PCI common code (Sebastian Ott) - Use pdev->dev.groups for attribute creation on s390 (Sebastian Ott) - Remove pcibios_add_platform_entries() (Sebastian Ott) - Add new ID for Intel GPU "spurious interrupt" quirk (Thomas Jarosch) - Rename pci_is_bridge() to pci_has_subordinate() (Yijing Wang) - Add and use new pci_is_bridge() interface (Yijing Wang) - Make pci_bus_add_device() void (Yijing Wang) DMA API - Clarify physical/bus address distinction in docs (Bjorn Helgaas) - Fix typos in docs (Emilio López) - Update dma_pool_create ()and dma_pool_alloc() descriptions (Gioh Kim) - Change dma_declare_coherent_memory() CPU address to phys_addr_t (Bjorn Helgaas) - Pass GAPSPCI_DMA_BASE CPU & bus address to dma_declare_coherent_memory() (Bjorn Helgaas)" * tag 'pci-v3.16-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (92 commits) MAINTAINERS: Add generic PCI host controller driver PCI: generic: Add generic PCI host controller driver PCI: imx6: Add support for MSI PCI: designware: Make MSI ISR shared IRQ aware PCI: imx6: Remove optional (and unused) IRQs PCI: imx6: Drop old IRQ mapping PCI: imx6: Use new clock names i82875p_edac: Assign PCI resources before adding device ARM/PCI: Call pcie_bus_configure_settings() to set MPS PCI: imx6: Fix imx6_add_pcie_port() section mismatch warning PCI: Make pci_bus_add_device() void PCI: exynos: Fix add_pcie_port() section mismatch warning PCI: Introduce new device binding path using pci_dev.driver_override PCI: rcar: Add gen2 device tree support PCI: cpqphp: Fix possible null pointer dereference PCI: rcar: Add R-Car PCIe device tree bindings PCI: rcar: Add MSI support for PCIe PCI: rcar: Add Renesas R-Car PCIe driver PCI: Fix return value from pci_user_{read,write}_config_*() PCI: exynos: Remove unnecessary OOM messages ...
2014-06-01Merge 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 fixlets, mostly related to the (root-only) SCHED_DEADLINE policy, but also a hotplug bug fix and a fix for a NR_CPUS related overallocation bug causing a suspend/resume regression" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix hotplug vs. set_cpus_allowed_ptr() sched/cpupri: Replace NR_CPUS arrays sched/deadline: Replace NR_CPUS arrays sched/deadline: Restrict user params max value to 2^63 ns sched/deadline: Change sched_getparam() behaviour vs SCHED_DEADLINE sched: Disallow sched_attr::sched_policy < 0 sched: Make sched_setattr() correctly return -EFBIG
2014-05-31Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core futex/rtmutex fixes from Thomas Gleixner: "Three fixlets for long standing issues in the futex/rtmutex code unearthed by Dave Jones syscall fuzzer: - Add missing early deadlock detection checks in the futex code - Prevent user space from attaching a futex to kernel threads - Make the deadlock detector of rtmutex work again Looks large, but is more comments than code change" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rtmutex: Fix deadlock detector for real futex: Prevent attaching to kernel threads futex: Add another early deadlock detection check
2014-05-28rtmutex: Fix deadlock detector for realThomas Gleixner
The current deadlock detection logic does not work reliably due to the following early exit path: /* * Drop out, when the task has no waiters. Note, * top_waiter can be NULL, when we are in the deboosting * mode! */ if (top_waiter && (!task_has_pi_waiters(task) || top_waiter != task_top_pi_waiter(task))) goto out_unlock_pi; So this not only exits when the task has no waiters, it also exits unconditionally when the current waiter is not the top priority waiter of the task. So in a nested locking scenario, it might abort the lock chain walk and therefor miss a potential deadlock. Simple fix: Continue the chain walk, when deadlock detection is enabled. We also avoid the whole enqueue, if we detect the deadlock right away (A-A). It's an optimization, but also prevents that another waiter who comes in after the detection and before the task has undone the damage observes the situation and detects the deadlock and returns -EDEADLOCK, which is wrong as the other task is not in a deadlock situation. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20140522031949.725272460@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-28Merge branch 'merge' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc Pull two powerpc fixes from Ben Herrenschmidt: "Here's a pair of powerpc fixes for 3.15 which are also going to stable. One's a fix for building with newer binutils (the problem currently only affects the BookE kernels but the affected macro might come back into use on BookS platforms at any time). Unfortunately, the binutils maintainer did a backward incompatible change to a construct that we use so we have to add Makefile check. The other one is a fix for CPUs getting stuck in kexec when running single threaded. Since we routinely use kexec on power (including in our newer bootloaders), I deemed that important enough" * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST mode powerpc: Fix 64 bit builds with binutils 2.24
2014-05-28powerpc, kexec: Fix "Processor X is stuck" issue during kexec from ST modeSrivatsa S. Bhat
If we try to perform a kexec when the machine is in ST (Single-Threaded) mode (ppc64_cpu --smt=off), the kexec operation doesn't succeed properly, and we get the following messages during boot: [ 0.089866] POWER8 performance monitor hardware support registered [ 0.089985] power8-pmu: PMAO restore workaround active. [ 5.095419] Processor 1 is stuck. [ 10.097933] Processor 2 is stuck. [ 15.100480] Processor 3 is stuck. [ 20.102982] Processor 4 is stuck. [ 25.105489] Processor 5 is stuck. [ 30.108005] Processor 6 is stuck. [ 35.110518] Processor 7 is stuck. [ 40.113369] Processor 9 is stuck. [ 45.115879] Processor 10 is stuck. [ 50.118389] Processor 11 is stuck. [ 55.120904] Processor 12 is stuck. [ 60.123425] Processor 13 is stuck. [ 65.125970] Processor 14 is stuck. [ 70.128495] Processor 15 is stuck. [ 75.131316] Processor 17 is stuck. Note that only the sibling threads are stuck, while the primary threads (0, 8, 16 etc) boot just fine. Looking closer at the previous step of kexec, we observe that kexec tries to wakeup (bring online) the sibling threads of all the cores, before performing kexec: [ 9464.131231] Starting new kernel [ 9464.148507] kexec: Waking offline cpu 1. [ 9464.148552] kexec: Waking offline cpu 2. [ 9464.148600] kexec: Waking offline cpu 3. [ 9464.148636] kexec: Waking offline cpu 4. [ 9464.148671] kexec: Waking offline cpu 5. [ 9464.148708] kexec: Waking offline cpu 6. [ 9464.148743] kexec: Waking offline cpu 7. [ 9464.148779] kexec: Waking offline cpu 9. [ 9464.148815] kexec: Waking offline cpu 10. [ 9464.148851] kexec: Waking offline cpu 11. [ 9464.148887] kexec: Waking offline cpu 12. [ 9464.148922] kexec: Waking offline cpu 13. [ 9464.148958] kexec: Waking offline cpu 14. [ 9464.148994] kexec: Waking offline cpu 15. [ 9464.149030] kexec: Waking offline cpu 17. Instrumenting this piece of code revealed that the cpu_up() operation actually fails with -EBUSY. Thus, only the primary threads of all the cores are online during kexec, and hence this is a sure-shot receipe for disaster, as explained in commit e8e5c2155b (powerpc/kexec: Fix orphaned offline CPUs across kexec), as well as in the comment above wake_offline_cpus(). It turns out that cpu_up() was returning -EBUSY because the variable 'cpu_hotplug_disabled' was set to 1; and this disabling of CPU hotplug was done by migrate_to_reboot_cpu() inside kernel_kexec(). Now, migrate_to_reboot_cpu() was originally written with the assumption that any further code will not need to perform CPU hotplug, since we are anyway in the reboot path. However, kexec is clearly not such a case, since we depend on onlining CPUs, atleast on powerpc. So re-enable cpu-hotplug after returning from migrate_to_reboot_cpu() in the kexec path, to fix this regression in kexec on powerpc. Also, wrap the cpu_up() in powerpc kexec code within a WARN_ON(), so that we can catch such issues more easily in the future. Fixes: c97102ba963 (kexec: migrate to reboot cpu) Cc: stable@vger.kernel.org Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-05-23Merge 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: "The biggest commit is an irqtime accounting loop latency fix, the rest are misc fixes all over the place: deadline scheduling, docs, numa, balancer and a bad to-idle latency fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/numa: Initialize newidle balance stats in sd_numa_init() sched: Fix updating rq->max_idle_balance_cost and rq->next_balance in idle_balance() sched: Skip double execution of pick_next_task_fair() sched: Use CPUPRI_NR_PRIORITIES instead of MAX_RT_PRIO in cpupri check sched/deadline: Fix memory leak sched/deadline: Fix sched_yield() behavior sched: Sanitize irq accounting madness sched/docbook: Fix 'make htmldocs' warnings caused by missing description
2014-05-23Merge 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: "The biggest changes are fixes for races that kept triggering Trinity crashes, plus liblockdep build fixes and smaller misc fixes. The liblockdep bits in perf/urgent are a pull mistake - they should have been in locking/urgent - but by the time I noticed other commits were added and testing was done :-/ Sorry about that" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix a race between ring_buffer_detach() and ring_buffer_attach() perf: Prevent false warning in perf_swevent_add perf: Limit perf_event_attr::sample_period to 63 bits tools/liblockdep: Remove all build files when doing make clean tools/liblockdep: Build liblockdep from tools/Makefile perf/x86/intel: Fix Silvermont's event constraints perf: Fix perf_event_init_context() perf: Fix race in removing an event
2014-05-23resources: Clarify sanity check messageBjorn Helgaas
The resource map sanity check message is a bit confusing. Change it to be more readable: -resource map sanity check conflict: 0xfed10000 0xfed15fff 0xfed10000 0xfed13fff pnp 00:01 +resource sanity check: requesting [mem 0xfed10000-0xfed15fff], which spans more than pnp 00:01 [mem 0xfed10000-0xfed13fff] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
2014-05-22sched: Fix hotplug vs. set_cpus_allowed_ptr()Lai Jiangshan
Lai found that: WARNING: CPU: 1 PID: 13 at arch/x86/kernel/smp.c:124 native_smp_send_reschedule+0x2d/0x4b() ... migration_cpu_stop+0x1d/0x22 was caused by set_cpus_allowed_ptr() assuming that cpu_active_mask is always a sub-set of cpu_online_mask. This isn't true since 5fbd036b552f ("sched: Cleanup cpu_active madness"). So set active and online at the same time to avoid this particular problem. Fixes: 5fbd036b552f ("sched: Cleanup cpu_active madness") Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Michael wang <wangyun@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Cc: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/53758B12.8060609@cn.fujitsu.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22sched/cpupri: Replace NR_CPUS arraysPeter Zijlstra
Tejun reported that his resume was failing due to order-3 allocations from sched_domain building. Replace the NR_CPUS arrays in there with a dynamically allocated array. Reported-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-7cysnkw1gik45r864t1nkudh@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22sched/deadline: Replace NR_CPUS arraysPeter Zijlstra
Tejun reported that his resume was failing due to order-3 allocations from sched_domain building. Replace the NR_CPUS arrays in there with a dynamically allocated array. Reported-by: Tejun Heo <tj@kernel.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-kat4gl1m5a6dwy6nzuqox45e@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22sched/deadline: Restrict user params max value to 2^63 nsJuri Lelli
Michael Kerrisk noticed that creating SCHED_DEADLINE reservations with certain parameters (e.g, a runtime of something near 2^64 ns) can cause a system freeze for some amount of time. The problem is that in the interface we have u64 sched_runtime; while internally we need to have a signed runtime (to cope with budget overruns) s64 runtime; At the time we setup a new dl_entity we copy the first value in the second. The cast turns out with negative values when sched_runtime is too big, and this causes the scheduler to go crazy right from the start. Moreover, considering how we deal with deadlines wraparound (s64)(a - b) < 0 we also have to restrict acceptable values for sched_{deadline,period}. This patch fixes the thing checking that user parameters are always below 2^63 ns (still large enough for everyone). It also rewrites other conditions that we check, since in __checkparam_dl we don't have to deal with deadline wraparounds and what we have now erroneously fails when the difference between values is too big. Reported-by: Michael Kerrisk <mtk.manpages@gmail.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Dario Faggioli<raistlin@linux.it> Cc: Dave Jones <davej@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140513141131.20d944f81633ee937f256385@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22sched/deadline: Change sched_getparam() behaviour vs SCHED_DEADLINEPeter Zijlstra
The way we read POSIX one should only call sched_getparam() when sched_getscheduler() returns either SCHED_FIFO or SCHED_RR. Given that we currently return sched_param::sched_priority=0 for all others, extend the same behaviour to SCHED_DEADLINE. Requested-by: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Dario Faggioli <raistlin@linux.it> Cc: linux-man <linux-man@vger.kernel.org> Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com> Cc: Juri Lelli <juri.lelli@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: <stable@vger.kernel.org> Link: http://lkml.kernel.org/r/20140512205034.GH13467@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22sched: Disallow sched_attr::sched_policy < 0Peter Zijlstra
The scheduler uses policy=-1 to preserve the current policy state to implement sys_sched_setparam(), this got exposed to userspace by accident through sys_sched_setattr(), cure this. Reported-by: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140509085311.GJ30445@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-22sched: Make sched_setattr() correctly return -EFBIGMichael Kerrisk
The documented[1] behavior of sched_attr() in the proposed man page text is: sched_attr::size must be set to the size of the structure, as in sizeof(struct sched_attr), if the provided structure is smaller than the kernel structure, any additional fields are assumed '0'. If the provided structure is larger than the kernel structure, the kernel verifies all additional fields are '0' if not the syscall will fail with -E2BIG. As currently implemented, sched_copy_attr() returns -EFBIG for for this case, but the logic in sys_sched_setattr() converts that error to -EFAULT. This patch fixes the behavior. [1] http://thread.gmane.org/gmane.linux.kernel/1615615/focus=1697760 Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/536CEC17.9070903@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-21Merge branch 'for-3.15-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull more cgroup fixes from Tejun Heo: "Three more patches to fix cgroup_freezer breakage due to the recent cgroup internal locking changes - an operation cgroup_freezer was using now requires sleepable context and cgroup_freezer was invoking that while holding a spin lock. cgroup_freezer was using an overly elaborate hierarchical locking scheme. While it's possible to convert the hierarchical spinlocks directly to mutexes, this patch simplifies the overall locking so that it uses a global mutex. This has the added benefit of avoiding iterating potentially huge number of tasks under a spinlock. While the patch is on the larger side in the devel cycle, the changes made are mostly straight-forward and the locking logic is a lot simpler afterwards" * 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix rcu_read_lock() leak in update_if_frozen() cgroup_freezer: replace freezer->lock with freezer_mutex cgroup: introduce task_css_is_root()
2014-05-20Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fix from Thomas Gleixner: "A single bug fix for a long standing issue: - Updating the expiry value of a relative timer _after_ letting the idle logic select a target cpu for the timer based on its stale expiry value is outright stupid. Thanks to Viresh for spotting the brainfart" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hrtimer: Set expiry time before switch_hrtimer_base()
2014-05-19perf: Fix a race between ring_buffer_detach() and ring_buffer_attach()Peter Zijlstra
Alexander noticed that we use RCU iteration on rb->event_list but do not use list_{add,del}_rcu() to add,remove entries to that list, nor do we observe proper grace periods when re-using the entries. Merge ring_buffer_detach() into ring_buffer_attach() such that attaching to the NULL buffer is detaching. Furthermore, ensure that between any 'detach' and 'attach' of the same event we observe the required grace period, but only when strictly required. In effect this means that only ioctl(.request = PERF_EVENT_IOC_SET_OUTPUT) will wait for a grace period, while the normal initial attach and final detach will not be delayed. This patch should, I think, do the right thing under all circumstances, the 'normal' cases all should never see the extra grace period, but the two cases: 1) PERF_EVENT_IOC_SET_OUTPUT on an event which already has a ring_buffer set, will now observe the required grace period between removing itself from the old and attaching itself to the new buffer. This case is 'simple' in that both buffers are present in perf_event_set_output() one could think an unconditional synchronize_rcu() would be sufficient; however... 2) an event that has a buffer attached, the buffer is destroyed (munmap) and then the event is attached to a new/different buffer using PERF_EVENT_IOC_SET_OUTPUT. This case is more complex because the buffer destruction does: ring_buffer_attach(.rb = NULL) followed by the ioctl() doing: ring_buffer_attach(.rb = foo); and we still need to observe the grace period between these two calls due to us reusing the event->rb_entry list_head. In order to make 2 happen we use Paul's latest cond_synchronize_rcu() call. Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Mike Galbraith <efault@gmx.de> Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140507123526.GD13658@twins.programming.kicks-ass.net Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-19perf: Prevent false warning in perf_swevent_addJiri Olsa
The perf cpu offline callback takes down all cpu context events and releases swhash->swevent_hlist. This could race with task context software event being just scheduled on this cpu via perf_swevent_add while cpu hotplug code already cleaned up event's data. The race happens in the gap between the cpu notifier code and the cpu being actually taken down. Note that only cpu ctx events are terminated in the perf cpu hotplug code. It's easily reproduced with: $ perf record -e faults perf bench sched pipe while putting one of the cpus offline: # echo 0 > /sys/devices/system/cpu/cpu1/online Console emits following warning: WARNING: CPU: 1 PID: 2845 at kernel/events/core.c:5672 perf_swevent_add+0x18d/0x1a0() Modules linked in: CPU: 1 PID: 2845 Comm: sched-pipe Tainted: G W 3.14.0+ #256 Hardware name: Intel Corporation Montevina platform/To be filled by O.E.M., BIOS AMVACRB1.86C.0066.B00.0805070703 05/07/2008 0000000000000009 ffff880077233ab8 ffffffff81665a23 0000000000200005 0000000000000000 ffff880077233af8 ffffffff8104732c 0000000000000046 ffff88007467c800 0000000000000002 ffff88007a9cf2a0 0000000000000001 Call Trace: [<ffffffff81665a23>] dump_stack+0x4f/0x7c [<ffffffff8104732c>] warn_slowpath_common+0x8c/0xc0 [<ffffffff8104737a>] warn_slowpath_null+0x1a/0x20 [<ffffffff8110fb3d>] perf_swevent_add+0x18d/0x1a0 [<ffffffff811162ae>] event_sched_in.isra.75+0x9e/0x1f0 [<ffffffff8111646a>] group_sched_in+0x6a/0x1f0 [<ffffffff81083dd5>] ? sched_clock_local+0x25/0xa0 [<ffffffff811167e6>] ctx_sched_in+0x1f6/0x450 [<ffffffff8111757b>] perf_event_sched_in+0x6b/0xa0 [<ffffffff81117a4b>] perf_event_context_sched_in+0x7b/0xc0 [<ffffffff81117ece>] __perf_event_task_sched_in+0x43e/0x460 [<ffffffff81096f1e>] ? put_lock_stats.isra.18+0xe/0x30 [<ffffffff8107b3c8>] finish_task_switch+0xb8/0x100 [<ffffffff8166a7de>] __schedule+0x30e/0xad0 [<ffffffff81172dd2>] ? pipe_read+0x3e2/0x560 [<ffffffff8166b45e>] ? preempt_schedule_irq+0x3e/0x70 [<ffffffff8166b45e>] ? preempt_schedule_irq+0x3e/0x70 [<ffffffff8166b464>] preempt_schedule_irq+0x44/0x70 [<ffffffff816707f0>] retint_kernel+0x20/0x30 [<ffffffff8109e60a>] ? lockdep_sys_exit+0x1a/0x90 [<ffffffff812a4234>] lockdep_sys_exit_thunk+0x35/0x67 [<ffffffff81679321>] ? sysret_check+0x5/0x56 Fixing this by tracking the cpu hotplug state and displaying the WARN only if current cpu is initialized properly. Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: stable@vger.kernel.org Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1396861448-10097-1-git-send-email-jolsa@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-19perf: Limit perf_event_attr::sample_period to 63 bitsPeter Zijlstra
Vince reported that using a large sample_period (one with bit 63 set) results in wreckage since while the sample_period is fundamentally unsigned (negative periods don't make sense) the way we implement things very much rely on signed logic. So limit sample_period to 63 bits to avoid tripping over this. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/n/tip-p25fhunibl4y3qi0zuqmyf4b@git.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-19futex: Prevent attaching to kernel threadsThomas Gleixner
We happily allow userspace to declare a random kernel thread to be the owner of a user space PI futex. Found while analysing the fallout of Dave Jones syscall fuzzer. We also should validate the thread group for private futexes and find some fast way to validate whether the "alleged" owner has RW access on the file which backs the SHM, but that's a separate issue. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Jones <davej@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <darren@dvhart.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Clark Williams <williams@redhat.com> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Carlos ODonell <carlos@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/20140512201701.194824402@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2014-05-19futex: Add another early deadlock detection checkThomas Gleixner
Dave Jones trinity syscall fuzzer exposed an issue in the deadlock detection code of rtmutex: http://lkml.kernel.org/r/20140429151655.GA14277@redhat.com That underlying issue has been fixed with a patch to the rtmutex code, but the futex code must not call into rtmutex in that case because - it can detect that issue early - it avoids a different and more complex fixup for backing out If the user space variable got manipulated to 0x80000000 which means no lock holder, but the waiters bit set and an active pi_state in the kernel is found we can figure out the recursive locking issue by looking at the pi_state owner. If that is the current task, then we can safely return -EDEADLK. The check should have been added in commit 59fa62451 (futex: Handle futex_pi OWNER_DIED take over correctly) already, but I did not see the above issue caused by user space manipulation back then. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Jones <davej@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <darren@dvhart.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Clark Williams <williams@redhat.com> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Carlos ODonell <carlos@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/20140512201701.097349971@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2014-05-13cgroup: fix rcu_read_lock() leak in update_if_frozen()Tejun Heo
While updating cgroup_freezer locking, 68fafb77d827 ("cgroup_freezer: replace freezer->lock with freezer_mutex") introduced a bug in update_if_frozen() where it returns with rcu_read_lock() held. Fix it by adding rcu_read_unlock() before returning. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: kbuild test robot <fengguang.wu@intel.com>
2014-05-13cgroup_freezer: replace freezer->lock with freezer_mutexTejun Heo
After 96d365e0b86e ("cgroup: make css_set_lock a rwsem and rename it to css_set_rwsem"), css task iterators requires sleepable context as it may block on css_set_rwsem. I missed that cgroup_freezer was iterating tasks under IRQ-safe spinlock freezer->lock. This leads to errors like the following on freezer state reads and transitions. BUG: sleeping function called from invalid context at /work /os/work/kernel/locking/rwsem.c:20 in_atomic(): 0, irqs_disabled(): 0, pid: 462, name: bash 5 locks held by bash/462: #0: (sb_writers#7){.+.+.+}, at: [<ffffffff811f0843>] vfs_write+0x1a3/0x1c0 #1: (&of->mutex){+.+.+.}, at: [<ffffffff8126d78b>] kernfs_fop_write+0xbb/0x170 #2: (s_active#70){.+.+.+}, at: [<ffffffff8126d793>] kernfs_fop_write+0xc3/0x170 #3: (freezer_mutex){+.+...}, at: [<ffffffff81135981>] freezer_write+0x61/0x1e0 #4: (rcu_read_lock){......}, at: [<ffffffff81135973>] freezer_write+0x53/0x1e0 Preemption disabled at:[<ffffffff81104404>] console_unlock+0x1e4/0x460 CPU: 3 PID: 462 Comm: bash Not tainted 3.15.0-rc1-work+ #10 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 ffff88000916a6d0 ffff88000e0a3da0 ffffffff81cf8c96 0000000000000000 ffff88000e0a3dc8 ffffffff810cf4f2 ffffffff82388040 ffff880013aaf740 0000000000000002 ffff88000e0a3de8 ffffffff81d05974 0000000000000246 Call Trace: [<ffffffff81cf8c96>] dump_stack+0x4e/0x7a [<ffffffff810cf4f2>] __might_sleep+0x162/0x260 [<ffffffff81d05974>] down_read+0x24/0x60 [<ffffffff81133e87>] css_task_iter_start+0x27/0x70 [<ffffffff8113584d>] freezer_apply_state+0x5d/0x130 [<ffffffff81135a16>] freezer_write+0xf6/0x1e0 [<ffffffff8112eb88>] cgroup_file_write+0xd8/0x230 [<ffffffff8126d7b7>] kernfs_fop_write+0xe7/0x170 [<ffffffff811f0756>] vfs_write+0xb6/0x1c0 [<ffffffff811f121d>] SyS_write+0x4d/0xc0 [<ffffffff81d08292>] system_call_fastpath+0x16/0x1b freezer->lock used to be used in hot paths but that time is long gone and there's no reason for the lock to be IRQ-safe spinlock or even per-cgroup. In fact, given the fact that a cgroup may contain large number of tasks, it's not a good idea to iterate over them while holding IRQ-safe spinlock. Let's simplify locking by replacing per-cgroup freezer->lock with global freezer_mutex. This also makes the comments explaining the intricacies of policy inheritance and the locking around it as the states are protected by a common mutex. The conversion is mostly straight-forward. The followings are worth mentioning. * freezer_css_online() no longer needs double locking. * freezer_attach() now performs propagation simply while holding freezer_mutex. update_if_frozen() race no longer exists and the comment is removed. * freezer_fork() now tests whether the task is in root cgroup using the new task_css_is_root() without doing rcu_read_lock/unlock(). If not, it grabs freezer_mutex and performs the operation. * freezer_read() and freezer_change_state() grab freezer_mutex across the whole operation and pin the css while iterating so that each descendant processing happens in sleepable context. Fixes: 96d365e0b86e ("cgroup: make css_set_lock a rwsem and rename it to css_set_rwsem") Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2014-05-13cgroup: introduce task_css_is_root()Tejun Heo
Determining the css of a task usually requires RCU read lock as that's the only thing which keeps the returned css accessible till its reference is acquired; however, testing whether a task belongs to the root can be performed without dereferencing the returned css by comparing the returned pointer against the root one in init_css_set[] which never changes. Implement task_css_is_root() which can be invoked in any context. This will be used by the scheduled cgroup_freezer change. v2: cgroup no longer supports modular controllers. No need to export init_css_set. Pointed out by Li. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
2014-05-13Merge branch 'for-3.15-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue fixes from Tejun Heo: "Fixes for two bugs in workqueue. One is exiting with internal mutex held in a failure path of wq_update_unbound_numa(). The other is a subtle and unlikely use-after-possible-last-put in the rescuer logic. Both have been around for quite some time now and are unlikely to have triggered noticeably often. All patches are marked for -stable backport" * 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: fix a possible race condition between rescuer and pwq-release workqueue: make rescuer_thread() empty wq->maydays list before exiting workqueue: fix bugs in wq_update_unbound_numa() failure path
2014-05-13Merge branch 'for-3.15-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "During recent restructuring, device_cgroup unified config input check and enforcement logic; unfortunately, it turned out to share too much. Aristeu's patches fix the breakage and marked for -stable backport. The other two patches are fallouts from kernfs conversion. The blkcg change is temporary and will go away once kernfs internal locking gets simplified (patches pending)" * 'for-3.15-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: blkcg: use trylock on blkcg_pol_mutex in blkcg_reset_stats() device_cgroup: check if exception removal is allowed device_cgroup: fix the comment format for recently added functions device_cgroup: rework device access check and exception checking cgroup: fix the retry path of cgroup_mount()
2014-05-12hrtimer: Set expiry time before switch_hrtimer_base()Viresh Kumar
switch_hrtimer_base() calls hrtimer_check_target() which ensures that we do not migrate a timer to a remote cpu if the timer expires before the current programmed expiry time on that remote cpu. But __hrtimer_start_range_ns() calls switch_hrtimer_base() before the new expiry time is set. So the sanity check in hrtimer_check_target() is operating on stale or even uninitialized data. Update expiry time before calling switch_hrtimer_base(). [ tglx: Rewrote changelog once again ] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: linaro-kernel@lists.linaro.org Cc: linaro-networking@linaro.org Cc: fweisbec@gmail.com Cc: arvind.chauhan@arm.com Link: http://lkml.kernel.org/r/81999e148745fc51bbcd0615823fbab9b2e87e23.1399882253.git.viresh.kumar@linaro.org Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-05-09Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Peter Anvin: "A somewhat unpleasantly large collection of small fixes. The big ones are the __visible tree sweep and a fix for 'earlyprintk=efi,keep'. It was using __init functions with predictably suboptimal results. Another key fix is a build fix which would produce output that simply would not decompress correctly in some configuration, due to the existing Makefiles picking up an unfortunate local label and mistaking it for the global symbol _end. Additional fixes include the handling of 64-bit numbers when setting the vdso data page (a latent bug which became manifest when i386 started exporting a vdso with time functions), a fix to the new MSR manipulation accessors which would cause features to not get properly unblocked, a build fix for 32-bit userland, and a few new platform quirks" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86, vdso, time: Cast tv_nsec to u64 for proper shifting in update_vsyscall() x86: Fix typo in MSR_IA32_MISC_ENABLE_LIMIT_CPUID macro x86: Fix typo preventing msr_set/clear_bit from having an effect x86/intel: Add quirk to disable HPET for the Baytrail platform x86/hpet: Make boot_hpet_disable extern x86-64, build: Fix stack protector Makefile breakage with 32-bit userland x86/reboot: Add reboot quirk for Certec BPC600 asmlinkage: Add explicit __visible to drivers/*, lib/*, kernel/* asmlinkage, x86: Add explicit __visible to arch/x86/* asmlinkage: Revert "lto: Make asmlinkage __visible" x86, build: Don't get confused by local symbols x86/efi: earlyprintk=efi,keep fix
2014-05-08Merge tag 'trace-fixes-v3.15-rc4-v2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "This contains two fixes. The first is a long standing bug that causes bogus data to show up in the refcnt field of the module_refcnt tracepoint. It was introduced by a merge conflict resolution back in 2.6.35-rc days. The result should be 'refcnt = incs - decs', but instead it did 'refcnt = incs + decs'. The second fix is to a bug that was introduced in this merge window that allowed for a tracepoint funcs pointer to be used after it was freed. Moving the location of where the probes are released solved the problem" * tag 'trace-fixes-v3.15-rc4-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracepoint: Fix use of tracepoint funcs after rcu free trace: module: Maintain a valid user count
2014-05-08tracepoint: Fix use of tracepoint funcs after rcu freeMathieu Desnoyers
Commit de7b2973903c "tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints" introduces a use after free by calling release_probes on the old struct tracepoint array before the newly allocated array is published with rcu_assign_pointer. There is a race window where tracepoints (RCU readers) can perform a "use-after-grace-period-after-free", which shows up as a GPF in stress-tests. Link: http://lkml.kernel.org/r/53698021.5020108@oracle.com Link: http://lkml.kernel.org/p/1399549669-25465-1-git-send-email-mathieu.desnoyers@efficios.com Reported-by: Sasha Levin <sasha.levin@oracle.com> CC: Oleg Nesterov <oleg@redhat.com> CC: Dave Jones <davej@redhat.com> Fixes: de7b2973903c "tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints" Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-07sched/numa: Initialize newidle balance stats in sd_numa_init()Jason Low
Also initialize the per-sd variables for newidle load balancing in sd_numa_init(). Signed-off-by: Jason Low <jason.low2@hp.com> Acked-by: morten.rasmussen@arm.com Cc: daniel.lezcano@linaro.org Cc: alex.shi@linaro.org Cc: preeti@linux.vnet.ibm.com Cc: efault@gmx.de Cc: vincent.guittot@linaro.org Cc: aswin@hp.com Cc: chegu_vinod@hp.com Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1398303035-18255-3-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07sched: Fix updating rq->max_idle_balance_cost and rq->next_balance in ↵Jason Low
idle_balance() The following commit: e5fc66119ec9 ("sched: Fix race in idle_balance()") can potentially cause rq->max_idle_balance_cost to not be updated, even when load_balance(NEWLY_IDLE) is attempted and the per-sd max cost value is updated. Preeti noticed a similar issue with updating rq->next_balance. In this patch, we fix this by making sure we still check/update those values even if a task gets enqueued while browsing the domains. Signed-off-by: Jason Low <jason.low2@hp.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: morten.rasmussen@arm.com Cc: aswin@hp.com Cc: daniel.lezcano@linaro.org Cc: alex.shi@linaro.org Cc: efault@gmx.de Cc: vincent.guittot@linaro.org Link: http://lkml.kernel.org/r/1398725155-7591-2-git-send-email-jason.low2@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07sched: Skip double execution of pick_next_task_fair()Peter Zijlstra
Tim wrote: "The current code will call pick_next_task_fair a second time in the slow path if we did not pull any task in our first try. This is really unnecessary as we already know no task can be pulled and it doubles the delay for the cpu to enter idle. We instrumented some network workloads and that saw that pick_next_task_fair is frequently called twice before a cpu enters idle. The call to pick_next_task_fair can add non trivial latency as it calls load_balance which runs find_busiest_group on an hierarchy of sched domains spanning the cpus for a large system. For some 4 socket systems, we saw almost 0.25 msec spent per call of pick_next_task_fair before a cpu can be idled." Optimize the second call away for the common case and document the dependency. Reported-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Len Brown <len.brown@intel.com> Link: http://lkml.kernel.org/r/20140424100047.GP11096@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07sched: Use CPUPRI_NR_PRIORITIES instead of MAX_RT_PRIO in cpupri checkSteven Rostedt (Red Hat)
The check at the beginning of cpupri_find() makes sure that the task_pri variable does not exceed the cp->pri_to_cpu array length. But that length is CPUPRI_NR_PRIORITIES not MAX_RT_PRIO, where it will miss the last two priorities in that array. As task_pri is computed from convert_prio() which should never be bigger than CPUPRI_NR_PRIORITIES, if the check should cause a panic if it is hit. Reported-by: Mike Galbraith <umgwanakikbuti@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1397015410.5212.13.camel@marge.simpson.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07sched/deadline: Fix memory leakLi Zefan
Free cpudl->free_cpus allocated in cpudl_init(). Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> # 3.14+ Link: http://lkml.kernel.org/r/534F36CE.2000409@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07sched/deadline: Fix sched_yield() behaviorJuri Lelli
yield_task_dl() is broken: o it forces current to be throttled setting its runtime to zero; o it sets current's dl_se->dl_new to one, expecting that dl_task_timer() will queue it back with proper parameters at replenish time. Unfortunately, dl_task_timer() has this check at the very beginning: if (!dl_task(p) || dl_se->dl_new) goto unlock; So, it just bails out and the task is never replenished. It actually yielded forever. To fix this, introduce a new flag indicating that the task properly yielded the CPU before its current runtime expired. While this is a little overdoing at the moment, the flag would be useful in the future to discriminate between "good" jobs (of which remaining runtime could be reclaimed, i.e. recycled) and "bad" jobs (for which dl_throttled task has been set) that needed to be stopped. Reported-by: yjay.kim <yjay.kim@lge.com> Signed-off-by: Juri Lelli <juri.lelli@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140429103953.e68eba1b2ac3309214e3dc5a@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07sched: Sanitize irq accounting madnessThomas Gleixner
Russell reported, that irqtime_account_idle_ticks() takes ages due to: for (i = 0; i < ticks; i++) irqtime_account_process_tick(current, 0, rq); It's sad, that this code was written way _AFTER_ the NOHZ idle functionality was available. I charge myself guitly for not paying attention when that crap got merged with commit abb74cefa ("sched: Export ns irqtimes through /proc/stat") So instead of looping nr_ticks times just apply the whole thing at once. As a side note: The whole cputime_t vs. u64 business in that context wants to be cleaned up as well. There is no point in having all these back and forth conversions. Lets standardise on u64 nsec for all kernel internal accounting and be done with it. Everything else does not make sense at all for fine grained accounting. Frederic, can you please take care of that? Reported-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Venkatesh Pallipadi <venki@google.com> Cc: Shaun Ruffell <sruffell@digium.com> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1405022307000.6261@ionos.tec.linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07perf: Fix perf_event_init_context()Peter Zijlstra
perf_pin_task_context() can return NULL but perf_event_init_context() assumes it will not, correct this. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Link: http://lkml.kernel.org/r/20140505171428.GU26782@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-07perf: Fix race in removing an eventPeter Zijlstra
When removing a (sibling) event we do: raw_spin_lock_irq(&ctx->lock); perf_group_detach(event); raw_spin_unlock_irq(&ctx->lock); <hole> perf_remove_from_context(event); raw_spin_lock_irq(&ctx->lock); ... raw_spin_unlock_irq(&ctx->lock); Now, assuming the event is a sibling, it will be 'unreachable' for things like ctx_sched_out() because that iterates the groups->siblings, and we just unhooked the sibling. So, if during <hole> we get ctx_sched_out(), it will miss the event and not call event_sched_out() on it, leaving it programmed on the PMU. The subsequent perf_remove_from_context() call will find the ctx is inactive and only call list_del_event() to remove the event from all other lists. Hereafter we can proceed to free the event; while still programmed! Close this hole by moving perf_group_detach() inside the same ctx->lock region(s) perf_remove_from_context() has. The condition on inherited events only in __perf_event_exit_task() is likely complete crap because non-inherited events are part of groups too and we're tearing down just the same. But leave that for another patch. Most-likely-Fixes: e03a9a55b4e ("perf: Change close() semantics for group events") Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Much-staring-at-traces-by: Vince Weaver <vincent.weaver@maine.edu> Much-staring-at-traces-by: Thomas Gleixner <tglx@linutronix.de> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20140505093124.GN17778@laptop.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-05asmlinkage: Add explicit __visible to drivers/*, lib/*, kernel/*Andi Kleen
As requested by Linus add explicit __visible to the asmlinkage users. This marks functions visible to assembler. Tree sweep for rest of tree. Signed-off-by: Andi Kleen <ak@linux.intel.com> Link: http://lkml.kernel.org/r/1398984278-29319-4-git-send-email-andi@firstfloor.org Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2014-05-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) e1000e computes header length incorrectly wrt vlans, fix from Vlad Yasevich. 2) ns_capable() check in sock_diag netlink code, from Andrew Lutomirski. 3) Fix invalid queue pairs handling in virtio_net, from Amos Kong. 4) Checksum offloading busted in sxgbe driver due to incorrect descriptor layout, fix from Byungho An. 5) Fix build failure with SMC_DEBUG set to 2 or larger, from Zi Shen Lim. 6) Fix uninitialized A and X registers in BPF interpreter, from Alexei Starovoitov. 7) Fix arch dependencies of candence driver. 8) Fix netlink capabilities checking tree-wide, from Eric W Biederman. 9) Don't dump IFLA_VF_PORTS if netlink request didn't ask for it in IFLA_EXT_MASK, from David Gibson. 10) IPV6 FIB dump restart doesn't handle table changes that happen meanwhile, causing the code to loop forever or emit dups, fix from Kumar Sandararajan. 11) Memory leak on VF removal in bnx2x, from Yuval Mintz. 12) Bug fixes for new Altera TSE driver from Vince Bridgers. 13) Fix route lookup key in SCTP, from Xugeng Zhang. 14) Use BH blocking spinlocks in SLIP, as per a similar fix to CAN/SLCAN driver. From Oliver Hartkopp. 15) TCP doesn't bump retransmit counters in some code paths, fix from Eric Dumazet. 16) Clamp delayed_ack in tcp_cubic to prevent theoretical divides by zero. Fix from Liu Yu. 17) Fix locking imbalance in error paths of HHF packet scheduler, from John Fastabend. 18) Properly reference the transport module when vsock_core_init() runs, from Andy King. 19) Fix buffer overflow in cdc_ncm driver, from Bjørn Mork. 20) IP_ECN_decapsulate() doesn't see a correct SKB network header in ip_tunnel_rcv(), fix from Ying Cai. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (132 commits) net: macb: Fix race between HW and driver net: macb: Remove 'unlikely' optimization net: macb: Re-enable RX interrupt only when RX is done net: macb: Clear interrupt flags net: macb: Pass same size to DMA_UNMAP as used for DMA_MAP ip_tunnel: Set network header properly for IP_ECN_decapsulate() e1000e: Restrict MDIO Slow Mode workaround to relevant parts e1000e: Fix issue with link flap on 82579 e1000e: Expand workaround for 10Mb HD throughput bug e1000e: Workaround for dropped packets in Gig/100 speeds on 82579 net/mlx4_core: Don't issue PCIe speed/width checks for VFs net/mlx4_core: Load the Eth driver first net/mlx4_core: Fix slave id computation for single port VF net/mlx4_core: Adjust port number in qp_attach wrapper when detaching net: cdc_ncm: fix buffer overflow Altera TSE: ALTERA_TSE should depend on HAS_DMA vsock: Make transport the proto owner net: sched: lock imbalance in hhf qdisc net: mvmdio: Check for a valid interrupt instead of an error net phy: Check for aneg completion before setting state to PHY_RUNNING ...
2014-05-03Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "This udpate delivers: - A fix for dynamic interrupt allocation on x86 which is required to exclude the GSI interrupts from the dynamic allocatable range. This was detected with the newfangled tablet SoCs which have GPIOs and therefor allocate a range of interrupts. The MSI allocations already excluded the GSI range, so we never noticed before. - The last missing set_irq_affinity() repair, which was delayed due to testing issues - A few bug fixes for the armada SoC interrupt controller - A memory allocation fix for the TI crossbar interrupt controller - A trivial kernel-doc warning fix" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip: irq-crossbar: Not allocating enough memory irqchip: armanda: Sanitize set_irq_affinity() genirq: x86: Ensure that dynamic irq allocation does not conflict linux/interrupt.h: fix new kernel-doc warnings irqchip: armada-370-xp: Fix releasing of MSIs irqchip: armada-370-xp: implement the ->check_device() msi_chip operation irqchip: armada-370-xp: fix invalid cast of signed value into unsigned variable
2014-05-03Merge 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: "This update brings along: - Two fixes for long standing bugs in the hrtimer code, one which prevents remote enqueuing and the other preventing arbitrary delays after a interrupt hang was detected - A fix in the timer wheel which prevents math overflow - A fix for a long standing issue with the architected ARM timer related to the C3STOP mechanism. - A trivial compile fix for nspire SoC clocksource" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: timer: Prevent overflow in apply_slack hrtimer: Prevent remote enqueue of leftmost timers hrtimer: Prevent all reprogramming if hang detected clocksource: nspire: Fix compiler warning clocksource: arch_arm_timer: Fix age-old arch timer C3STOP detection issue
2014-05-03Merge tag 'trace-fixes-v3.15-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fix from Steven Rostedt: "This is a small fix where the trigger code used the wrong rcu_dereference(). It required rcu_dereference_sched() instead of the normal rcu_dereference(). It produces a nasty RCU lockdep splat due to the incorrect rcu notation" Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> * tag 'trace-fixes-v3.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Use rcu_dereference_sched() for trace event triggers
2014-05-02tracing: Use rcu_dereference_sched() for trace event triggersSteven Rostedt (Red Hat)
As trace event triggers are now part of the mainline kernel, I added my trace event trigger tests to my test suite I run on all my kernels. Now these tests get run under different config options, and one of those options is CONFIG_PROVE_RCU, which checks under lockdep that the rcu locking primitives are being used correctly. This triggered the following splat: =============================== [ INFO: suspicious RCU usage. ] 3.15.0-rc2-test+ #11 Not tainted ------------------------------- kernel/trace/trace_events_trigger.c:80 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 4 locks held by swapper/1/0: #0: ((&(&j_cdbs->work)->timer)){..-...}, at: [<ffffffff8104d2cc>] call_timer_fn+0x5/0x1be #1: (&(&pool->lock)->rlock){-.-...}, at: [<ffffffff81059856>] __queue_work+0x140/0x283 #2: (&p->pi_lock){-.-.-.}, at: [<ffffffff8106e961>] try_to_wake_up+0x2e/0x1e8 #3: (&rq->lock){-.-.-.}, at: [<ffffffff8106ead3>] try_to_wake_up+0x1a0/0x1e8 stack backtrace: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.15.0-rc2-test+ #11 Hardware name: /DG965MQ, BIOS MQ96510J.86A.0372.2006.0605.1717 06/05/2006 0000000000000001 ffff88007e083b98 ffffffff819f53a5 0000000000000006 ffff88007b0942c0 ffff88007e083bc8 ffffffff81081307 ffff88007ad96d20 0000000000000000 ffff88007af2d840 ffff88007b2e701c ffff88007e083c18 Call Trace: <IRQ> [<ffffffff819f53a5>] dump_stack+0x4f/0x7c [<ffffffff81081307>] lockdep_rcu_suspicious+0x107/0x110 [<ffffffff810ee51c>] event_triggers_call+0x99/0x108 [<ffffffff810e8174>] ftrace_event_buffer_commit+0x42/0xa4 [<ffffffff8106aadc>] ftrace_raw_event_sched_wakeup_template+0x71/0x7c [<ffffffff8106bcbf>] ttwu_do_wakeup+0x7f/0xff [<ffffffff8106bd9b>] ttwu_do_activate.constprop.126+0x5c/0x61 [<ffffffff8106eadf>] try_to_wake_up+0x1ac/0x1e8 [<ffffffff8106eb77>] wake_up_process+0x36/0x3b [<ffffffff810575cc>] wake_up_worker+0x24/0x26 [<ffffffff810578bc>] insert_work+0x5c/0x65 [<ffffffff81059982>] __queue_work+0x26c/0x283 [<ffffffff81059999>] ? __queue_work+0x283/0x283 [<ffffffff810599b7>] delayed_work_timer_fn+0x1e/0x20 [<ffffffff8104d3a6>] call_timer_fn+0xdf/0x1be^M [<ffffffff8104d2cc>] ? call_timer_fn+0x5/0x1be [<ffffffff81059999>] ? __queue_work+0x283/0x283 [<ffffffff8104d823>] run_timer_softirq+0x1a4/0x22f^M [<ffffffff8104696d>] __do_softirq+0x17b/0x31b^M [<ffffffff81046d03>] irq_exit+0x42/0x97 [<ffffffff81a08db6>] smp_apic_timer_interrupt+0x37/0x44 [<ffffffff81a07a2f>] apic_timer_interrupt+0x6f/0x80 <EOI> [<ffffffff8100a5d8>] ? default_idle+0x21/0x32 [<ffffffff8100a5d6>] ? default_idle+0x1f/0x32 [<ffffffff8100ac10>] arch_cpu_idle+0xf/0x11 [<ffffffff8107b3a4>] cpu_startup_entry+0x1a3/0x213 [<ffffffff8102a23c>] start_secondary+0x212/0x219 The cause is that the triggers are protected by rcu_read_lock_sched() but the data is dereferenced with rcu_dereference() which expects it to be protected with rcu_read_lock(). The proper reference should be rcu_dereference_sched(). Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: stable@vger.kernel.org # 3.14+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-05-01Merge tag 'fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux Pull module fixes from Rusty Russell: "Fixed one missing place for the new taint flag, and remove a warning giving only false positives (now we finally figured out why)" * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: module: remove warning about waiting module removal. Fix: tracing: use 'E' instead of 'X' for unsigned module taint flag
2014-04-30timer: Prevent overflow in apply_slackJiri Bohac
On architectures with sizeof(int) < sizeof (long), the computation of mask inside apply_slack() can be undefined if the computed bit is > 32. E.g. with: expires = 0xffffe6f5 and slack = 25, we get: expires_limit = 0x20000000e bit = 33 mask = (1 << 33) - 1 /* undefined */ On x86, mask becomes 1 and and the slack is not applied properly. On s390, mask is -1, expires is set to 0 and the timer fires immediately. Use 1UL << bit to solve that issue. Suggested-by: Deborah Townsend <dstownse@us.ibm.com> Signed-off-by: Jiri Bohac <jbohac@suse.cz> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20140418152310.GA13654@midget.suse.cz Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-04-30hrtimer: Prevent remote enqueue of leftmost timersLeon Ma
If a cpu is idle and starts an hrtimer which is not pinned on that same cpu, the nohz code might target the timer to a different cpu. In the case that we switch the cpu base of the timer we already have a sanity check in place, which determines whether the timer is earlier than the current leftmost timer on the target cpu. In that case we enqueue the timer on the current cpu because we cannot reprogram the clock event device on the target. If the timers base is already the target CPU we do not have this sanity check in place so we enqueue the timer as the leftmost timer in the target cpus rb tree, but we cannot reprogram the clock event device on the target cpu. So the timer expires late and subsequently prevents the reprogramming of the target cpu clock event device until the previously programmed event fires or a timer with an earlier expiry time gets enqueued on the target cpu itself. Add the same target check as we have for the switch base case and start the timer on the current cpu if it would become the leftmost timer on the target. [ tglx: Rewrote subject and changelog ] Signed-off-by: Leon Ma <xindong.ma@intel.com> Link: http://lkml.kernel.org/r/1398847391-5994-1-git-send-email-xindong.ma@intel.com Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>