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2016-01-11Merge branch 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
Pull workqueue update from Tejun Heo: "Workqueue changes for v4.5. One cleanup patch and three to improve the debuggability. Workqueue now has a stall detector which dumps workqueue state if any worker pool hasn't made forward progress over a certain amount of time (30s by default) and also triggers a warning if a workqueue which can be used in memory reclaim path tries to wait on something which can't be. These should make workqueue hangs a lot easier to debug." * 'for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: simplify the apply_workqueue_attrs_locked() workqueue: implement lockup detector watchdog: introduce touch_softlockup_watchdog_sched() workqueue: warn if memory reclaim tries to flush !WQ_MEM_RECLAIM workqueue
2016-01-11Merge branch 'irq-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "The irq department provides: - Support for MSI to wire bridges and a first user of it - More ACPI support for ARM/GIC - A new TS-4800 interrupt controller driver - RCU based free of interrupt descriptors to support the upcoming Intel VMD technology without introducing a locking nightmare - The usual pile of fixes and updates to drivers and core code" * 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) irqchip/omap-intc: Add support for spurious irq handling irqchip/zevio: Use irq_data_get_chip_type() helper irqchip/omap-intc: Remove duplicate setup for IRQ chip type handler irqchip/ts4800: Add TS-4800 interrupt controller irqchip/ts4800: Add documentation for TS-4800 interrupt controller irq/platform-MSI: Increase the maximum MSIs the MSI framework can support irqchip/gicv2m: Miscellaneous fixes for v2m resources and SPI ranges irqchip/bcm2836: Make code more readable irqchip/bcm2836: Tolerate IRQs while no flag is set in ISR irqchip/bcm2836: Add SMP support for the 2836 irqchip/bcm2836: Fix initialization of the LOCAL_IRQ_CNT timers irqchip/gic-v2m: acpi: Introducing GICv2m ACPI support irqchip/gic-v2m: Refactor to prepare for ACPI support irqdomain: Introduce is_fwnode_irqchip helper acpi: pci: Setup MSI domain for ACPI based pci devices genirq/msi: Export functions to allow MSI domains in modules irqchip/mbigen: Implement the mbigen irq chip operation functions irqchip/mbigen: Create irq domain for each mbigen device irqchip/mgigen: Add platform device driver for mbigen device dt-bindings: Documents the mbigen bindings ...
2016-01-11Merge branches 'timers-core-for-linus' and 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates - and a leftover fix - from Thomas Gleixner: "A rather large (commit wise) update from the timer side: - A bulk update to make compile tests work in the clocksource drivers - An overhaul of the h8300 timers - Some more Y2038 work - A few overflow prevention checks in the timekeeping/ntp code - The usual pile of fixes and improvements to the various clocksource/clockevent drivers and core code" Also: "A single fix for the posix-clock poll code which did not make it into 4.4" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits) clocksource/drivers/acpi_pm: Convert to pr_* macros clocksource: Make clocksource validation work for all clocksources timekeeping: Cap adjustments so they don't exceed the maxadj value ntp: Fix second_overflow's input parameter type to be 64bits ntp: Change time_reftime to time64_t and utilize 64bit __ktime_get_real_seconds timekeeping: Provide internal function __ktime_get_real_seconds clocksource/drivers/h8300: Use ioread / iowrite clocksource/drivers/h8300: Initializer cleanup. clocksource/drivers/h8300: Simplify delta handling clocksource/drivers/h8300: Fix timer not overflow case clocksource/drivers/h8300: Change to overflow interrupt clocksource/drivers/lpc32: Correct pr_err() output format clocksource/drivers/arm_global_timer: Fix suspend resume clocksource/drivers/pistachio: Fix wrong calculated clocksource read value clockevents/drivers/arm_global_timer: Use writel_relaxed in gt_compare_set clocksource/drivers/dw_apb_timer: Inline apbt_readl and apbt_writel clocksource/drivers/dw_apb_timer: Use {readl|writel}_relaxed in critical path clocksource/drivers/dw_apb_timer: Fix apbt_readl return types clocksource/drivers/tango-xtal: Replace code by clocksource_mmio_init clocksource/drivers/h8300: Increase the compilation test coverage ... * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: posix-clock: Fix return code on the poll method's error path
2016-01-11Merge branch 'x86-asm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 asm updates from Ingo Molnar: "The main changes in this cycle were: - vDSO and asm entry improvements (Andy Lutomirski) - Xen paravirt entry enhancements (Boris Ostrovsky) - asm entry labels enhancement (Borislav Petkov) - and other misc changes (Thomas Gleixner, me)" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/vsdo: Fix build on PARAVIRT_CLOCK=y, KVM_GUEST=n Revert "x86/kvm: On KVM re-enable (e.g. after suspend), update clocks" x86/entry/64_compat: Make labels local x86/platform/uv: Include clocksource.h for clocksource_touch_watchdog() x86/vdso: Enable vdso pvclock access on all vdso variants x86/vdso: Remove pvclock fixmap machinery x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap x86, vdso, pvclock: Simplify and speed up the vdso pvclock reader x86/kvm: On KVM re-enable (e.g. after suspend), update clocks x86/entry/64: Bypass enter_from_user_mode on non-context-tracking boots x86/asm: Add asm macros for static keys/jump labels x86/asm: Error out if asm/jump_label.h is included inappropriately context_tracking: Switch to new static_branch API x86/entry, x86/paravirt: Remove the unused usergs_sysret32 PV op x86/paravirt: Remove the unused irq_enable_sysexit pv op x86/xen: Avoid fast syscall path for Xen PV guests
2016-01-11Merge branch 'x86-apic-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 apic updates from Ingo Molnar: "The main changes in this cycle were: - introduce optimized single IPI sending methods on modern APICs (Linus Torvalds, Thomas Gleixner) - kexec/crash APIC handling fixes and enhancements (Hidehiro Kawai) - extend lapic vector saving/restoring to the CMCI (MCE) vector as well (Juergen Gross) - various fixes and enhancements (Jake Oshins, Len Brown)" * 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/irq: Export functions to allow MSI domains in modules Documentation: Document kernel.panic_on_io_nmi sysctl x86/nmi: Save regs in crash dump on external NMI x86/apic: Introduce apic_extnmi command line parameter kexec: Fix race between panic() and crash_kexec() panic, x86: Allow CPUs to save registers even if looping in NMI context panic, x86: Fix re-entrance problem due to panic on NMI x86/apic: Fix the saving and restoring of lapic vectors during suspend/resume x86/smpboot: Re-enable init_udelay=0 by default on modern CPUs x86/smp: Remove single IPI wrapper x86/apic: Use default send single IPI wrapper x86/apic: Provide default send single IPI wrapper x86/apic: Implement single IPI for apic_noop x86/apic: Wire up single IPI for apic_numachip x86/apic: Wire up single IPI for x2apic_uv x86/apic: Implement single IPI for x2apic_phys x86/apic: Wire up single IPI for bigsmp_apic x86/apic: Remove pointless indirections from bigsmp_apic x86/apic: Wire up single IPI for apic_physflat x86/apic: Remove pointless indirections from apic_physflat ...
2016-01-11Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "The main changes in this cycle were: - tickless load average calculation enhancements (Byungchul Park) - vtime handling enhancements (Frederic Weisbecker) - scalability improvement via properly aligning a key structure field (Jiri Olsa) - various stop_machine() fixes (Oleg Nesterov) - sched/numa enhancement (Rik van Riel) - various fixes and improvements (Andi Kleen, Dietmar Eggemann, Geliang Tang, Hiroshi Shimamoto, Joonwoo Park, Peter Zijlstra, Waiman Long, Wanpeng Li, Yuyang Du)" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) sched/fair: Fix new task's load avg removed from source CPU in wake_up_new_task() sched/core: Move sched_entity::avg into separate cache line x86/fpu: Properly align size in CHECK_MEMBER_AT_END_OF() macro sched/deadline: Fix the earliest_dl.next logic sched/fair: Disable the task group load_avg update for the root_task_group sched/fair: Move the cache-hot 'load_avg' variable into its own cacheline sched/fair: Avoid redundant idle_cpu() call in update_sg_lb_stats() sched/core: Move the sched_to_prio[] arrays out of line sched/cputime: Convert vtime_seqlock to seqcount sched/cputime: Introduce vtime accounting check for readers sched/cputime: Rename vtime_accounting_enabled() to vtime_accounting_cpu_enabled() sched/cputime: Correctly handle task guest time on housekeepers sched/cputime: Clarify vtime symbols and document them sched/cputime: Remove extra cost in task_cputime() sched/fair: Make it possible to account fair load avg consistently sched/fair: Modify the comment about lock assumptions in migrate_task_rq_fair() stop_machine: Clean up the usage of the preemption counter in cpu_stopper_thread() stop_machine: Shift the 'done != NULL' check from cpu_stop_signal_done() to callers stop_machine: Kill cpu_stop_done->executed stop_machine: Change __stop_cpus() to rely on cpu_stop_queue_work() ...
2016-01-11Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Ingo Molnar: "Kernel side changes: - Intel Knights Landing support. (Harish Chegondi) - Intel Broadwell-EP uncore PMU support. (Kan Liang) - Core code improvements. (Peter Zijlstra.) - Event filter, LBR and PEBS fixes. (Stephane Eranian) - Enable cycles:pp on Intel Atom. (Stephane Eranian) - Add cycles:ppp support for Skylake. (Andi Kleen) - Various x86 NMI overhead optimizations. (Andi Kleen) - Intel PT enhancements. (Takao Indoh) - AMD cache events fix. (Vince Weaver) Tons of tooling changes: - Show random perf tool tips in the 'perf report' bottom line (Namhyung Kim) - perf report now defaults to --group if the perf.data file has grouped events, try it with: # perf record -e '{cycles,instructions}' -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 1.093 MB perf.data (1247 samples) ] # perf report # Samples: 1K of event 'anon group { cycles, instructions }' # Event count (approx.): 1955219195 # # Overhead Command Shared Object Symbol 2.86% 0.22% swapper [kernel.kallsyms] [k] intel_idle 1.05% 0.33% firefox libxul.so [.] js::SetObjectElement 1.05% 0.00% kworker/0:3 [kernel.kallsyms] [k] gen6_ring_get_seqno 0.88% 0.17% chrome chrome [.] 0x0000000000ee27ab 0.65% 0.86% firefox libxul.so [.] js::ValueToId<(js::AllowGC)1> 0.64% 0.23% JS Helper libxul.so [.] js::SplayTree<js::jit::LiveRange*, js::jit::LiveRange>::splay 0.62% 1.27% firefox libxul.so [.] js::GetIterator 0.61% 1.74% firefox libxul.so [.] js::NativeSetProperty 0.61% 0.31% firefox libxul.so [.] js::SetPropertyByDefining - Introduce the 'perf stat record/report' workflow: Generate perf.data files from 'perf stat', to tap into the scripting capabilities perf has instead of defining a 'perf stat' specific scripting support to calculate event ratios, etc. Simple example: $ perf stat record -e cycles usleep 1 Performance counter stats for 'usleep 1': 1,134,996 cycles 0.000670644 seconds time elapsed $ perf stat report Performance counter stats for '/home/acme/bin/perf stat record -e cycles usleep 1': 1,134,996 cycles 0.000670644 seconds time elapsed $ It generates PERF_RECORD_ userspace records to store the details: $ perf report -D | grep PERF_RECORD 0xf0 [0x28]: PERF_RECORD_THREAD_MAP nr: 1 thread: 27637 0x118 [0x12]: PERF_RECORD_CPU_MAP nr: 1 cpu: 65535 0x12a [0x40]: PERF_RECORD_STAT_CONFIG 0x16a [0x30]: PERF_RECORD_STAT -1 -1 0x19a [0x40]: PERF_RECORD_MMAP -1/0: [0xffffffff81000000(0x1f000000) @ 0xffffffff81000000]: x [kernel.kallsyms]_text 0x1da [0x18]: PERF_RECORD_STAT_ROUND [acme@ssdandy linux]$ An effort was made to make perf.data files generated like this to not generate cryptic messages when processed by older tools. The 'perf script' bits need rebasing, will go up later. - Make command line options always available, even when they depend on some feature being enabled, warning the user about use of such options (Wang Nan) - Support hw breakpoint events (mem:0xAddress) in the default output mode in 'perf script' (Wang Nan) - Fixes and improvements for supporting annotating ARM binaries, support ARM call and jump instructions, more work needed to have arch specific stuff separated into tools/perf/arch/*/annotate/ (Russell King) - Add initial 'perf config' command, for now just with a --list command to the contents of the configuration file in use and a basic man page describing its format, commands for doing edits and detailed documentation are being reviewed and proof-read. (Taeung Song) - Allows BPF scriptlets specify arguments to be fetched using DWARF info, using a prologue generated at compile/build time (He Kuang, Wang Nan) - Allow attaching BPF scriptlets to module symbols (Wang Nan) - Allow attaching BPF scriptlets to userspace code using uprobe (Wang Nan) - BPF programs now can specify 'perf probe' tunables via its section name, separating key=val values using semicolons (Wang Nan) Testing some of these new BPF features: Use case: get callchains when receiving SSL packets, filter then in the kernel, at arbitrary place. # cat ssl.bpf.c #define SEC(NAME) __attribute__((section(NAME), used)) struct pt_regs; SEC("func=__inet_lookup_established hnum") int func(struct pt_regs *ctx, int err, unsigned short port) { return err == 0 && port == 443; } char _license[] SEC("license") = "GPL"; int _version SEC("version") = LINUX_VERSION_CODE; # # perf record -a -g -e ssl.bpf.c ^C[ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.787 MB perf.data (3 samples) ] # perf script | head -30 swapper 0 [000] 58783.268118: perf_bpf_probe:func: (ffffffff816a0f60) hnum=0x1bb 8a0f61 __inet_lookup_established (/lib/modules/4.3.0+/build/vmlinux) 896def ip_rcv_finish (/lib/modules/4.3.0+/build/vmlinux) 8976c2 ip_rcv (/lib/modules/4.3.0+/build/vmlinux) 855eba __netif_receive_skb_core (/lib/modules/4.3.0+/build/vmlinux) 8565d8 __netif_receive_skb (/lib/modules/4.3.0+/build/vmlinux) 8572a8 process_backlog (/lib/modules/4.3.0+/build/vmlinux) 856b11 net_rx_action (/lib/modules/4.3.0+/build/vmlinux) 2a284b __do_softirq (/lib/modules/4.3.0+/build/vmlinux) 2a2ba3 irq_exit (/lib/modules/4.3.0+/build/vmlinux) 96b7a4 do_IRQ (/lib/modules/4.3.0+/build/vmlinux) 969807 ret_from_intr (/lib/modules/4.3.0+/build/vmlinux) 2dede5 cpu_startup_entry (/lib/modules/4.3.0+/build/vmlinux) 95d5bc rest_init (/lib/modules/4.3.0+/build/vmlinux) 1163ffa start_kernel ([kernel.vmlinux].init.text) 11634d7 x86_64_start_reservations ([kernel.vmlinux].init.text) 1163623 x86_64_start_kernel ([kernel.vmlinux].init.text) qemu-system-x86 9178 [003] 58785.792417: perf_bpf_probe:func: (ffffffff816a0f60) hnum=0x1bb 8a0f61 __inet_lookup_established (/lib/modules/4.3.0+/build/vmlinux) 896def ip_rcv_finish (/lib/modules/4.3.0+/build/vmlinux) 8976c2 ip_rcv (/lib/modules/4.3.0+/build/vmlinux) 855eba __netif_receive_skb_core (/lib/modules/4.3.0+/build/vmlinux) 8565d8 __netif_receive_skb (/lib/modules/4.3.0+/build/vmlinux) 856660 netif_receive_skb_internal (/lib/modules/4.3.0+/build/vmlinux) 8566ec netif_receive_skb_sk (/lib/modules/4.3.0+/build/vmlinux) 430a br_handle_frame_finish ([bridge]) 48bc br_handle_frame ([bridge]) 855f44 __netif_receive_skb_core (/lib/modules/4.3.0+/build/vmlinux) 8565d8 __netif_receive_skb (/lib/modules/4.3.0+/build/vmlinux) # - Use 'perf probe' various options to list functions, see what variables can be collected at any given point, experiment first collecting without a filter, then filter, use it together with 'perf trace', 'perf top', with or without callchains, if it explodes, please tell us! - Introduce a new callchain mode: "folded", that will list per line representations of all callchains for a give histogram entry, facilitating 'perf report' output processing by other tools, such as Brendan Gregg's flamegraph tools (Namhyung Kim) E.g: # perf report | grep -v ^# | head 18.37% 0.00% swapper [kernel.kallsyms] [k] cpu_startup_entry | ---cpu_startup_entry | |--12.07%--start_secondary | --6.30%--rest_init start_kernel x86_64_start_reservations x86_64_start_kernel # Becomes, in "folded" mode: # perf report -g folded | grep -v ^# | head -5 18.37% 0.00% swapper [kernel.kallsyms] [k] cpu_startup_entry 12.07% cpu_startup_entry;start_secondary 6.30% cpu_startup_entry;rest_init;start_kernel;x86_64_start_reservations;x86_64_start_kernel 16.90% 0.00% swapper [kernel.kallsyms] [k] call_cpuidle 11.23% call_cpuidle;cpu_startup_entry;start_secondary 5.67% call_cpuidle;cpu_startup_entry;rest_init;start_kernel;x86_64_start_reservations;x86_64_start_kernel 16.90% 0.00% swapper [kernel.kallsyms] [k] cpuidle_enter 11.23% cpuidle_enter;call_cpuidle;cpu_startup_entry;start_secondary 5.67% cpuidle_enter;call_cpuidle;cpu_startup_entry;rest_init;start_kernel;x86_64_start_reservations;x86_64_start_kernel 15.12% 0.00% swapper [kernel.kallsyms] [k] cpuidle_enter_state # The user can also select one of "count", "period" or "percent" as the first column. ... and lots of infrastructure enhancements, plus fixes and other changes, features I failed to list - see the shortlog and the git log for details" * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (271 commits) perf evlist: Add --trace-fields option to show trace fields perf record: Store data mmaps for dwarf unwind perf libdw: Check for mmaps also in MAP__VARIABLE tree perf unwind: Check for mmaps also in MAP__VARIABLE tree perf unwind: Use find_map function in access_dso_mem perf evlist: Remove perf_evlist__(enable|disable)_event functions perf evlist: Make perf_evlist__open() open evsels with their cpus and threads (like perf record does) perf report: Show random usage tip on the help line perf hists: Export a couple of hist functions perf diff: Use perf_hpp__register_sort_field interface perf tools: Add overhead/overhead_children keys defaults via string perf tools: Remove list entry from struct sort_entry perf tools: Include all tools/lib directory for tags/cscope/TAGS targets perf script: Align event name properly perf tools: Add missing headers in perf's MANIFEST perf tools: Do not show trace command if it's not compiled in perf report: Change default to use event group view perf top: Decay periods in callchains tools lib: Move bitmap.[ch] from tools/perf/ to tools/{lib,include}/ tools lib: Sync tools/lib/find_bit.c with the kernel ...
2016-01-11Merge branch 'locking-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "So we have a laundry list of locking subsystem changes: - continuing barrier API and code improvements - futex enhancements - atomics API improvements - pvqspinlock enhancements: in particular lock stealing and adaptive spinning - qspinlock micro-enhancements" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT op futex: Cleanup the goto confusion in requeue_pi() futex: Remove pointless put_pi_state calls in requeue() futex: Document pi_state refcounting in requeue code futex: Rename free_pi_state() to put_pi_state() futex: Drop refcount if requeue_pi() acquired the rtmutex locking/barriers, arch: Remove ambiguous statement in the smp_store_mb() documentation lcoking/barriers, arch: Use smp barriers in smp_store_release() locking/cmpxchg, arch: Remove tas() definitions locking/pvqspinlock: Queue node adaptive spinning locking/pvqspinlock: Allow limited lock stealing locking/pvqspinlock: Collect slowpath lock statistics sched/core, locking: Document Program-Order guarantees locking, sched: Introduce smp_cond_acquire() and use it locking/pvqspinlock, x86: Optimize the PV unlock code path locking/qspinlock: Avoid redundant read of next pointer locking/qspinlock: Prefetch the next node cacheline locking/qspinlock: Use _acquire/_release() versions of cmpxchg() & xchg() atomics: Add test for atomic operations with _relaxed variants
2016-01-11Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU updates from Ingo Molnar: "The changes in this cycle were: - Adding transitivity uniformly to rcu_node structure ->lock acquisitions. (This is implemented by the first two commits on top of v4.4-rc2 due to the pervasive nature of this change.) - Documentation updates, including RCU requirements. - Expedited grace-period changes. - Miscellaneous fixes. - Linked-list fixes, courtesy of KTSAN. - Torture-test updates. - Late-breaking fix to sysrq-generated crash. One thing I should note is that these pieces of documentation are fairly large files: .../RCU/Design/Requirements/Requirements.html | 2897 ++++++++++++++++++++ .../RCU/Design/Requirements/Requirements.htmlx | 2741 ++++++++++++++++++ and are written in HTML, not the usual .txt style. I hope they are fine" Paul McKenney explains the html docs: "For whatever it is worth, the reason for this unconventional choice was that attempts to do the diagrams in ASCII art failed miserably. And attempts to do ASCII art for the upcoming documentation of the data structures failed even more miserably" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits) sysrq: Fix warning in sysrq generated crash. list: Add lockless list traversal primitives rcu: Make rcu_gp_init() be bool rather than int rcu: Move wakeup out from under rnp->lock rcu: Fix comment for rcu_dereference_raw_notrace rcu: Don't redundantly disable irqs in rcu_irq_{enter,exit}() rcu: Make cpu_needs_another_gp() be bool rcu: Eliminate unused rcu_init_one() argument rcu: Remove TINY_RCU bloat from pointless boot parameters torture: Place console.log files correctly from the get-go torture: Abbreviate console error dump rcutorture: Print symbolic name for ->gp_state rcutorture: Print symbolic name for rcu_torture_writer_state rcutorture: Remove CONFIG_RCU_USER_QS from rcutorture selftest doc rcutorture: Default grace period to three minutes, allow override rcutorture: Dump stack when GP kthread stalls rcutorture: Flag nonexistent RCU GP kthread rcutorture: Add batch number to script printout Documentation/memory-barriers.txt: Fix ACCESS_ONCE thinko documentation: Update RCU requirements based on expedited changes ...
2016-01-08Merge 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: "Misc scheduler fixes" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Reset task's lockless wake-queues on fork() sched/core: Fix unserialized r-m-w scribbling stuff sched/core: Check tgid in is_global_init() sched/fair: Fix multiplication overflow on 32-bit systems
2016-01-08Merge 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: "Two core subsystem fixes, plus a handful of tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix race in swevent hash perf: Fix race in perf_event_exec() perf list: Robustify event printing routine perf list: Add support for PERF_COUNT_SW_BPF_OUT perf hists browser: Fix segfault if use symbol filter in cmdline perf hists browser: Reset selection when refresh perf hists browser: Add NULL pointer check to prevent crash perf buildid-list: Fix return value of perf buildid-list -k perf buildid-list: Show running kernel build id fix
2016-01-08Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fix from Ingo Molnar: "Fixes a core IRQ subsystem deadlock" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: genirq: Prevent chip buslock deadlock
2016-01-07Merge tag 'trace-v4.4-rc4-4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull ftrace fix from Steven Rostedt: "PeiyangX Qiu reported that if a module fails to load between calling ftrace_module_init() and do_init_module() that the allocations made in ftrace_module_init() will not be freed, resulting in a memory leak. The solution is to call ftrace_release_mod() on the failing module in the fail path befor do_init_module() is called. This will remove any allocations made for that module, and nothing if ftrace_module_init() wasn't called yet for that module. Note, once do_init_module() is called, the MODULE_GOING notifiers are called for the failed module, which calls into the ftrace code to do the proper clean up (basically calling ftrace_release_mod())" * tag 'trace-v4.4-rc4-4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace/module: Call clean up function when module init fails early
2016-01-07ftrace/module: Call clean up function when module init fails earlySteven Rostedt (Red Hat)
If the module init code fails after calling ftrace_module_init() and before calling do_init_module(), we can suffer from a memory leak. This is because ftrace_module_init() allocates pages to store the locations that ftrace hooks are placed in the module text. If do_init_module() fails, it still calls the MODULE_GOING notifiers which will tell ftrace to do a clean up of the pages it allocated for the module. But if load_module() fails before then, the pages allocated by ftrace_module_init() will never be freed. Call ftrace_release_mod() on the module if load_module() fails before getting to do_init_module(). Link: http://lkml.kernel.org/r/567CEA31.1070507@intel.com Reported-by: "Qiu, PeiyangX" <peiyangx.qiu@intel.com> Fixes: a949ae560a511 "ftrace/module: Hardcode ftrace_module_init() call into load_module()" Cc: stable@vger.kernel.org # v2.6.38+ Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-01-07workqueue: simplify the apply_workqueue_attrs_locked()wanghaibin
If the apply_wqattrs_prepare() returns NULL, it has already cleaned up the related resources, so it can return directly and avoid calling the clean up function again. This doesn't introduce any functional changes. Signed-off-by: wanghaibin <wanghaibin.wang@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-01-06Merge branch 'for-mingo' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu Pull RCU changes from Paul E. McKenney: - Adding transitivity uniformly to rcu_node structure ->lock acquisitions. (This is implemented by the first two commits on top of v4.4-rc2 due to the pervasive nature of this change.) - Documentation updates, including RCU requirements. - Expedited grace-period changes. - Miscellaneous fixes. - Linked-list fixes, courtesy of KTSAN. - Torture-test updates. - Late-breaking fix to sysrq-generated crash. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06perf/core: Collapse more IPI loopsPeter Zijlstra
This patch collapses the two 'hard' cases, which are perf_event_{dis,en}able(). I cannot seem to convince myself the current code is correct. So starting with perf_event_disable(); we don't strictly need to test for event->state == ACTIVE, ctx->is_active is enough. If the event is not scheduled while the ctx is, __perf_event_disable() still does the right thing. Its a little less efficient to IPI in that case, over-all simpler. For perf_event_enable(); the same goes, but I think that's actually broken in its current form. The current condition is: ctx->is_active && event->state == OFF, that means it doesn't do anything when !ctx->active && event->state == OFF. This is wrong, it should still mark the event INACTIVE in that case, otherwise we'll still not try and schedule the event once the context becomes active again. This patch implements the two function using the new event_function_call() and does away with the tricky event->state tests. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alexander Shishkin <alexander.shishkin@intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06Merge branch 'perf/urgent' into perf/core, to pick up fixes before applying ↵Ingo Molnar
new changes Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06sched/fair: Fix new task's load avg removed from source CPU in ↵Yuyang Du
wake_up_new_task() If a newly created task is selected to go to a different CPU in fork balance when it wakes up the first time, its load averages should not be removed from the source CPU since they are never added to it before. The same is also applicable to a never used group entity. Fix it in remove_entity_load_avg(): when entity's last_update_time is 0, simply return. This should precisely identify the case in question, because in other migrations, the last_update_time is set to 0 after remove_entity_load_avg(). Reported-by: Steve Muckle <steve.muckle@linaro.org> Signed-off-by: Yuyang Du <yuyang.du@intel.com> [peterz: cfs_rq_last_update_time] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Juri Lelli <Juri.Lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Patrick Bellasi <patrick.bellasi@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincent Guittot <vincent.guittot@linaro.org> Link: http://lkml.kernel.org/r/20151216233427.GJ28098@intel.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06sched/deadline: Fix the earliest_dl.next logicWanpeng Li
earliest_dl.next should cache deadline of the earliest ready task that is also enqueued in the pushable rbtree, as pull algorithm uses this information to find candidates for migration: if the earliest_dl.next deadline of source rq is earlier than the earliest_dl.curr deadline of destination rq, the task from the source rq can be pulled. However, current implementation only guarantees that earliest_dl.next is the deadline of the next ready task instead of the next pushable task; which will result in potentially holding both rqs' lock and find nothing to migrate because of affinity constraints. In addition, current logic doesn't update the next candidate for pushing in pick_next_task_dl(), even if the running task is never eligible. This patch fixes both problems by updating earliest_dl.next when pushable dl task is enqueued/dequeued, similar to what we already do for RT. Tested-by: Luca Abeni <luca.abeni@unitn.it> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Juri Lelli <juri.lelli@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1449135730-27202-1-git-send-email-wanpeng.li@hotmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06Merge branch 'sched/urgent' into sched/core, to pick up fixes before merging ↵Ingo Molnar
new patches Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06sched/core: Reset task's lockless wake-queues on fork()Sebastian Andrzej Siewior
In the following commit: 7675104990ed ("sched: Implement lockless wake-queues") we gained lockless wake-queues. The -RT kernel managed to lockup itself with those. There could be multiple attempts for task X to enqueue it for a wakeup _even_ if task X is already running. The reason is that task X could be runnable but not yet on CPU. The the task performing the wakeup did not leave the CPU it could performe multiple wakeups. With the proper timming task X could be running and enqueued for a wakeup. If this happens while X is performing a fork() then its its child will have a !NULL `wake_q` member copied. This is not a problem as long as the child task does not participate in lockless wakeups :) Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 7675104990ed ("sched: Implement lockless wake-queues") Link: http://lkml.kernel.org/r/20151221171710.GA5499@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06sched/fair: Fix multiplication overflow on 32-bit systemsAndrey Ryabinin
Make 'r' 64-bit type to avoid overflow in 'r * LOAD_AVG_MAX' on 32-bit systems: UBSAN: Undefined behaviour in kernel/sched/fair.c:2785:18 signed integer overflow: 87950 * 47742 cannot be represented in type 'int' The most likely effect of this bug are bad load average numbers resulting in weird scheduling. It's also likely that this can persist for a longer time - until the system goes idle for a long time so that all load avg numbers get reset. [ This is the CFS load average metric, not the procfs output, which is separate. ] Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 9d89c257dfb9 ("sched/fair: Rewrite runnable load and utilization average tracking") Link: http://lkml.kernel.org/r/1450097243-30137-1-git-send-email-aryabinin@virtuozzo.com [ Improved the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06perf: Fix race in swevent hashPeter Zijlstra
There's a race on CPU unplug where we free the swevent hash array while it can still have events on. This will result in a use-after-free which is BAD. Simply do not free the hash array on unplug. This leaves the thing around and no use-after-free takes place. When the last swevent dies, we do a for_each_possible_cpu() iteration anyway to clean these up, at which time we'll free it, so no leakage will occur. Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-06perf: Fix race in perf_event_exec()Peter Zijlstra
I managed to tickle this warning: [ 2338.884942] ------------[ cut here ]------------ [ 2338.890112] WARNING: CPU: 13 PID: 35162 at ../kernel/events/core.c:2702 task_ctx_sched_out+0x6b/0x80() [ 2338.900504] Modules linked in: [ 2338.903933] CPU: 13 PID: 35162 Comm: bash Not tainted 4.4.0-rc4-dirty #244 [ 2338.911610] Hardware name: Intel Corporation S2600GZ/S2600GZ, BIOS SE5C600.86B.02.02.0002.122320131210 12/23/2013 [ 2338.923071] ffffffff81f1468e ffff8807c6457cb8 ffffffff815c680c 0000000000000000 [ 2338.931382] ffff8807c6457cf0 ffffffff810c8a56 ffffe8ffff8c1bd0 ffff8808132ed400 [ 2338.939678] 0000000000000286 ffff880813170380 ffff8808132ed400 ffff8807c6457d00 [ 2338.947987] Call Trace: [ 2338.950726] [<ffffffff815c680c>] dump_stack+0x4e/0x82 [ 2338.956474] [<ffffffff810c8a56>] warn_slowpath_common+0x86/0xc0 [ 2338.963195] [<ffffffff810c8b4a>] warn_slowpath_null+0x1a/0x20 [ 2338.969720] [<ffffffff811a49cb>] task_ctx_sched_out+0x6b/0x80 [ 2338.976244] [<ffffffff811a62d2>] perf_event_exec+0xe2/0x180 [ 2338.982575] [<ffffffff8121fb6f>] setup_new_exec+0x6f/0x1b0 [ 2338.988810] [<ffffffff8126de83>] load_elf_binary+0x393/0x1660 [ 2338.995339] [<ffffffff811dc772>] ? get_user_pages+0x52/0x60 [ 2339.001669] [<ffffffff8121e297>] search_binary_handler+0x97/0x200 [ 2339.008581] [<ffffffff8121f8b3>] do_execveat_common.isra.33+0x543/0x6e0 [ 2339.016072] [<ffffffff8121fcea>] SyS_execve+0x3a/0x50 [ 2339.021819] [<ffffffff819fc165>] stub_execve+0x5/0x5 [ 2339.027469] [<ffffffff819fbeb2>] ? entry_SYSCALL_64_fastpath+0x12/0x71 [ 2339.034860] ---[ end trace ee1337c59a0ddeac ]--- Which is a WARN_ON_ONCE() indicating that cpuctx->task_ctx is not what we expected it to be. This is because context switches can swap the task_struct::perf_event_ctxp[] pointer around. Therefore you have to either disable preemption when looking at current, or hold ctx->lock. Fix perf_event_enable_on_exec(), it loads current->perf_event_ctxp[] before disabling interrupts, therefore a preemption in the right place can swap contexts around and we're using the wrong one. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Potapenko <glider@google.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: syzkaller <syzkaller@googlegroups.com> Link: http://lkml.kernel.org/r/20151210195740.GG6357@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-05Merge tag 'trace-v4.4-rc4-3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "Two more fixes: 1. The recordmcount change had an output that used sprintf() (incorrectly) when it should have been a fprintf() to stderr. 2. The printk_formats file could crash if someone added a trace_printk() in the core kernel, and also added one in a module. This does not affect production kernels. Only kernels where developers add trace_printk() for debugging can crash" * tag 'trace-v4.4-rc4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix setting of start_index in find_next() ftrace/scripts: Fix incorrect use of sprintf in recordmcount
2016-01-04tracing: Fix setting of start_index in find_next()Qiu Peiyang
When we do cat /sys/kernel/debug/tracing/printk_formats, we hit kernel panic at t_show. general protection fault: 0000 [#1] PREEMPT SMP CPU: 0 PID: 2957 Comm: sh Tainted: G W O 3.14.55-x86_64-01062-gd4acdc7 #2 RIP: 0010:[<ffffffff811375b2>] [<ffffffff811375b2>] t_show+0x22/0xe0 RSP: 0000:ffff88002b4ebe80 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000004 RDX: 0000000000000004 RSI: ffffffff81fd26a6 RDI: ffff880032f9f7b1 RBP: ffff88002b4ebe98 R08: 0000000000001000 R09: 000000000000ffec R10: 0000000000000000 R11: 000000000000000f R12: ffff880004d9b6c0 R13: 7365725f6d706400 R14: ffff880004d9b6c0 R15: ffffffff82020570 FS: 0000000000000000(0000) GS:ffff88003aa00000(0063) knlGS:00000000f776bc40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f6c02ff0 CR3: 000000002c2b3000 CR4: 00000000001007f0 Call Trace: [<ffffffff811dc076>] seq_read+0x2f6/0x3e0 [<ffffffff811b749b>] vfs_read+0x9b/0x160 [<ffffffff811b7f69>] SyS_read+0x49/0xb0 [<ffffffff81a3a4b9>] ia32_do_call+0x13/0x13 ---[ end trace 5bd9eb630614861e ]--- Kernel panic - not syncing: Fatal exception When the first time find_next calls find_next_mod_format, it should iterate the trace_bprintk_fmt_list to find the first print format of the module. However in current code, start_index is smaller than *pos at first, and code will not iterate the list. Latter container_of will get the wrong address with former v, which will cause mod_fmt be a meaningless object and so is the returned mod_fmt->fmt. This patch will fix it by correcting the start_index. After fixed, when the first time calls find_next_mod_format, start_index will be equal to *pos, and code will iterate the trace_bprintk_fmt_list to get the right module printk format, so is the returned mod_fmt->fmt. Link: http://lkml.kernel.org/r/5684B900.9000309@intel.com Cc: stable@vger.kernel.org # 3.12+ Fixes: 102c9323c35a8 "tracing: Add __tracepoint_string() to export string pointers" Signed-off-by: Qiu Peiyang <peiyangx.qiu@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-12-29posix-clock: Fix return code on the poll method's error pathRichard Cochran
The posix_clock_poll function is supposed to return a bit mask of POLLxxx values. However, in case the hardware has disappeared (due to hot plugging for example) this code returns -ENODEV in a futile attempt to throw an error at the file descriptor level. The kernel's file_operations interface does not accept such error codes from the poll method. Instead, this function aught to return POLLERR. The value -ENODEV does, in fact, contain the POLLERR bit (and almost all the other POLLxxx bits as well), but only by chance. This patch fixes code to return a proper bit mask. Credit goes to Markus Elfring for pointing out the suspicious signed/unsigned mismatch. Reported-by: Markus Elfring <elfring@users.sourceforge.net> igned-off-by: Richard Cochran <richardcochran@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Julia Lawall <julia.lawall@lip6.fr> Link: http://lkml.kernel.org/r/1450819198-17420-1-git-send-email-richardcochran@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-29Merge branch 'irq/gic-v2m-acpi' of ↵Thomas Gleixner
git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core Pull another round of GIC changes from Marc: ACPI support for GIV-v2m
2015-12-21irqdomain: Introduce is_fwnode_irqchip helperSuravee Suthikulpanit
Since there will be several places checking if fwnode.type is equal FWNODE_IRQCHIP, this patch adds a convenient function for this purpose. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-20futex: Allow FUTEX_CLOCK_REALTIME with FUTEX_WAIT opDarren Hart
While reviewing Michael Kerrisk's recent futex manpage update, I noticed that we allow the FUTEX_CLOCK_REALTIME flag for FUTEX_WAIT_BITSET but not for FUTEX_WAIT. FUTEX_WAIT is treated as a simple version for FUTEX_WAIT_BITSET internally (with a bitmask of FUTEX_BITSET_MATCH_ANY). As such, I cannot come up with a reason for this exclusion for FUTEX_WAIT. This change does modify the behavior of the futex syscall, changing a call with FUTEX_WAIT | FUTEX_CLOCK_REALTIME from returning -ENOSYS, to be equivalent to FUTEX_WAIT_BITSET | FUTEX_CLOCK_REALTIME with a bitset of FUTEX_BITSET_MATCH_ANY. Reported-by: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Darren Hart <dvhart@linux.intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Davidlohr Bueso <dave@stgolabs.net> Link: http://lkml.kernel.org/r/9f3bdc116d79d23f5ee72ceb9a2a857f5ff8fa29.1450474525.git.dvhart@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-20futex: Cleanup the goto confusion in requeue_pi()Thomas Gleixner
out_unlock: does not only drop the locks, it also drops the refcount on the pi_state. Really intuitive. Move the label after the put_pi_state() call and use 'break' in the error handling path of the requeue loop. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <darren@dvhart.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Bhuvanesh_Surachari@mentor.com Cc: Andy Lowe <Andy_Lowe@mentor.com> Link: http://lkml.kernel.org/r/20151219200607.526665141@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-20futex: Remove pointless put_pi_state calls in requeue()Thomas Gleixner
In the error handling cases we neither have pi_state nor a reference to it. Remove the pointless code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <darren@dvhart.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Bhuvanesh_Surachari@mentor.com Cc: Andy Lowe <Andy_Lowe@mentor.com> Link: http://lkml.kernel.org/r/20151219200607.432780944@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-20futex: Document pi_state refcounting in requeue codeThomas Gleixner
Documentation of the pi_state refcounting in the requeue code is non existent. Add it. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <darren@dvhart.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Bhuvanesh_Surachari@mentor.com Cc: Andy Lowe <Andy_Lowe@mentor.com> Link: http://lkml.kernel.org/r/20151219200607.335938312@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-20futex: Rename free_pi_state() to put_pi_state()Thomas Gleixner
free_pi_state() is confusing as it is in fact only freeing/caching the pi state when the last reference is gone. Rename it to put_pi_state() which reflects better what it is doing. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <darren@dvhart.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Bhuvanesh_Surachari@mentor.com Cc: Andy Lowe <Andy_Lowe@mentor.com> Link: http://lkml.kernel.org/r/20151219200607.259636467@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-20futex: Drop refcount if requeue_pi() acquired the rtmutexThomas Gleixner
If the proxy lock in the requeue loop acquires the rtmutex for a waiter then it acquired also refcount on the pi_state related to the futex, but the waiter side does not drop the reference count. Add the missing free_pi_state() call. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <darren@dvhart.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Bhuvanesh_Surachari@mentor.com Cc: Andy Lowe <Andy_Lowe@mentor.com> Link: http://lkml.kernel.org/r/20151219200607.178132067@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org
2015-12-20genirq/msi: Export functions to allow MSI domains in modulesJake Oshins
The Linux kernel already has the concept of IRQ domain, wherein a component can expose a set of IRQs which are managed by a particular interrupt controller chip or other subsystem. The PCI driver exposes the notion of an IRQ domain for Message-Signaled Interrupts (MSI) from PCI Express devices. This patch exposes the functions which are necessary for creating a MSI IRQ domain within a module. [ tglx: Split it into x86 and core irq parts ] Signed-off-by: Jake Oshins <jakeo@microsoft.com> Cc: gregkh@linuxfoundation.org Cc: kys@microsoft.com Cc: devel@linuxdriverproject.org Cc: olaf@aepfle.de Cc: apw@canonical.com Cc: vkuznets@redhat.com Cc: haiyangz@microsoft.com Cc: marc.zyngier@arm.com Cc: bhelgaas@google.com Link: http://lkml.kernel.org/r/1449769983-12948-4-git-send-email-jakeo@microsoft.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-19clocksource: Make clocksource validation work for all clocksourcesYang Yingliang
The clocksource validation which makes sure that the newly read value is not smaller than the last value only works if the clocksource mask is 64bit, i.e. the counter is 64bit wide. But we want to use that mechanism also for clocksources which are less than 64bit wide. So instead of checking whether bit 63 is set, we check whether the most significant bit of the clocksource mask is set in the delta result. If it is set, we return 0. [ tglx: Simplified the implementation, added a comment and massaged the commit message ] Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Cc: <linux-arm-kernel@lists.infradead.org> Link: http://lkml.kernel.org/r/56349607.6070708@huawei.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-19Merge branch 'irq/wire-msi-bridge' of ↵Thomas Gleixner
git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core Pull the MSI wire bridge implementation from Marc Zyngier along with the first user of it. This is infrastructure to support a wired interrupt to MSI interrupt brigde. The first user is mbigen found in Hisilicon ARM SoCs.
2015-12-19Merge branch 'fortglx/4.5/time' of ↵Thomas Gleixner
https://git.linaro.org/people/john.stultz/linux into timers/core Get the core time(keeping) updates from John Stultz - NTP robustness tweaks - Another signed overflow nailed down - More y2038 changes - Stop alarmtimer after resume - MAINTAINERS update - Selftest fixes
2015-12-19kexec: Fix race between panic() and crash_kexec()Hidehiro Kawai
Currently, panic() and crash_kexec() can be called at the same time. For example (x86 case): CPU 0: oops_end() crash_kexec() mutex_trylock() // acquired nmi_shootdown_cpus() // stop other CPUs CPU 1: panic() crash_kexec() mutex_trylock() // failed to acquire smp_send_stop() // stop other CPUs infinite loop If CPU 1 calls smp_send_stop() before nmi_shootdown_cpus(), kdump fails. In another case: CPU 0: oops_end() crash_kexec() mutex_trylock() // acquired <NMI> io_check_error() panic() crash_kexec() mutex_trylock() // failed to acquire infinite loop Clearly, this is an undesirable result. To fix this problem, this patch changes crash_kexec() to exclude others by using the panic_cpu atomic. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Baoquan He <bhe@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: kexec@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Minfei Huang <mnfhuang@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Seth Jennings <sjenning@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: x86-ml <x86@kernel.org> Link: http://lkml.kernel.org/r/20151210014630.25437.94161.stgit@softrs Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-19panic, x86: Allow CPUs to save registers even if looping in NMI contextHidehiro Kawai
Currently, kdump_nmi_shootdown_cpus(), a subroutine of crash_kexec(), sends an NMI IPI to CPUs which haven't called panic() to stop them, save their register information and do some cleanups for crash dumping. However, if such a CPU is infinitely looping in NMI context, we fail to save its register information into the crash dump. For example, this can happen when unknown NMIs are broadcast to all CPUs as follows: CPU 0 CPU 1 =========================== ========================== receive an unknown NMI unknown_nmi_error() panic() receive an unknown NMI spin_trylock(&panic_lock) unknown_nmi_error() crash_kexec() panic() spin_trylock(&panic_lock) panic_smp_self_stop() infinite loop kdump_nmi_shootdown_cpus() issue NMI IPI -----------> blocked until IRET infinite loop... Here, since CPU 1 is in NMI context, the second NMI from CPU 0 is blocked until CPU 1 executes IRET. However, CPU 1 never executes IRET, so the NMI is not handled and the callback function to save registers is never called. In practice, this can happen on some servers which broadcast NMIs to all CPUs when the NMI button is pushed. To save registers in this case, we need to: a) Return from NMI handler instead of looping infinitely or b) Call the callback function directly from the infinite loop Inherently, a) is risky because NMI is also used to prevent corrupted data from being propagated to devices. So, we chose b). This patch does the following: 1. Move the infinite looping of CPUs which haven't called panic() in NMI context (actually done by panic_smp_self_stop()) outside of panic() to enable us to refer pt_regs. Please note that panic_smp_self_stop() is still used for normal context. 2. Call a callback of kdump_nmi_shootdown_cpus() directly to save registers and do some cleanups after setting waiting_for_crash_ipi which is used for counting down the number of CPUs which handled the callback Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Dave Young <dyoung@redhat.com> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Gobinda Charan Maji <gobinda.cemk07@gmail.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Javi Merino <javi.merino@arm.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: kexec@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: lkml <linux-kernel@vger.kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Seth Jennings <sjenning@redhat.com> Cc: Stefan Lippers-Hollmann <s.l-h@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Link: http://lkml.kernel.org/r/20151210014628.25437.75256.stgit@softrs [ Cleanup comments, fixup formatting. ] Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-19panic, x86: Fix re-entrance problem due to panic on NMIHidehiro Kawai
If panic on NMI happens just after panic() on the same CPU, panic() is recursively called. Kernel stalls, as a result, after failing to acquire panic_lock. To avoid this problem, don't call panic() in NMI context if we've already entered panic(). For that, introduce nmi_panic() macro to reduce code duplication. In the case of panic on NMI, don't return from NMI handlers if another CPU already panicked. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Aaron Tomlin <atomlin@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: David Hildenbrand <dahi@linux.vnet.ibm.com> Cc: Don Zickus <dzickus@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Gobinda Charan Maji <gobinda.cemk07@gmail.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Javi Merino <javi.merino@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: kexec@lists.infradead.org Cc: linux-doc@vger.kernel.org Cc: lkml <linux-kernel@vger.kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Seth Jennings <sjenning@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Link: http://lkml.kernel.org/r/20151210014626.25437.13302.stgit@softrs [ Cleanup comments, fixup formatting. ] Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-17locking/osq: Fix ordering of node initialisation in osq_lockWill Deacon
The Cavium guys reported a soft lockup on their arm64 machine, caused by commit c55a6ffa6285 ("locking/osq: Relax atomic semantics"): mutex_optimistic_spin+0x9c/0x1d0 __mutex_lock_slowpath+0x44/0x158 mutex_lock+0x54/0x58 kernfs_iop_permission+0x38/0x70 __inode_permission+0x88/0xd8 inode_permission+0x30/0x6c link_path_walk+0x68/0x4d4 path_openat+0xb4/0x2bc do_filp_open+0x74/0xd0 do_sys_open+0x14c/0x228 SyS_openat+0x3c/0x48 el0_svc_naked+0x24/0x28 This is because in osq_lock we initialise the node for the current CPU: node->locked = 0; node->next = NULL; node->cpu = curr; and then publish the current CPU in the lock tail: old = atomic_xchg_acquire(&lock->tail, curr); Once the update to lock->tail is visible to another CPU, the node is then live and can be both read and updated by concurrent lockers. Unfortunately, the ACQUIRE semantics of the xchg operation mean that there is no guarantee the contents of the node will be visible before lock tail is updated. This can lead to lock corruption when, for example, a concurrent locker races to set the next field. Fixes: c55a6ffa6285 ("locking/osq: Relax atomic semantics"): Reported-by: David Daney <ddaney@caviumnetworks.com> Reported-by: Andrew Pinski <andrew.pinski@caviumnetworks.com> Tested-by: Andrew Pinski <andrew.pinski@caviumnetworks.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: http://lkml.kernel.org/r/1449856001-21177-1-git-send-email-will.deacon@arm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-12-16timekeeping: Cap adjustments so they don't exceed the maxadj valueJohn Stultz
Thus its been occasionally noted that users have seen confusing warnings like: Adjusting tsc more than 11% (5941981 vs 7759439) We try to limit the maximum total adjustment to 11% (10% tick adjustment + 0.5% frequency adjustment). But this is done by bounding the requested adjustment values, and the internal steering that is done by tracking the error from what was requested and what was applied, does not have any such limits. This is usually not problematic, but in some cases has a risk that an adjustment could cause the clocksource mult value to overflow, so its an indication things are outside of what is expected. It ends up most of the reports of this 11% warning are on systems using chrony, which utilizes the adjtimex() ADJ_TICK interface (which allows a +-10% adjustment). The original rational for ADJ_TICK unclear to me but my assumption it was originally added to allow broken systems to get a big constant correction at boot (see adjtimex userspace package for an example) which would allow the system to work w/ ntpd's 0.5% adjustment limit. Chrony uses ADJ_TICK to make very aggressive short term corrections (usually right at startup). Which push us close enough to the max bound that a few late ticks can cause the internal steering to push past the max adjust value (tripping the warning). Thus this patch adds some extra logic to enforce the max adjustment cap in the internal steering. Note: This has the potential to slow corrections when the ADJ_TICK value is furthest away from the default value. So it would be good to get some testing from folks using chrony, to make sure we don't cause any troubles there. Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Tested-by: Miroslav Lichvar <mlichvar@redhat.com> Reported-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-12-16ntp: Fix second_overflow's input parameter type to be 64bitsDengChao
The function "second_overflow" uses "unsign long" as its input parameter type which will overflow after year 2106 on 32bit systems. Thus this patch replaces it with time64_t type. While the 64-bit division is expensive, "next_ntp_leap_sec" has been calculated already, so we can just re-use it in the TIME_INS/DEL cases, allowing one expensive division per leapsecond instead of re-doing the divsion once a second after the leap flag has been set. Signed-off-by: DengChao <chao.deng@linaro.org> [jstultz: Tweaked commit message] Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-12-16ntp: Change time_reftime to time64_t and utilize 64bit __ktime_get_real_secondsDengChao
The type of static variant "time_reftime" and the call of get_seconds in ntp are both not y2038 safe. So change the type of time_reftime to time64_t and replace get_seconds with __ktime_get_real_seconds. The local variant "secs" in ntp_update_offset represents seconds between now and last ntp adjustment, it seems impossible that this time will last more than 68 years, so keep its type as "long". Reviewed-by: John Stultz <john.stultz@linaro.org> Signed-off-by: DengChao <chao.deng@linaro.org> [jstultz: Tweaked commit message] Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-12-16timekeeping: Provide internal function __ktime_get_real_secondsDengChao
In order to fix Y2038 issues in the ntp code we will need replace get_seconds() with ktime_get_real_seconds() but as the ntp code uses the timekeeping lock which is also used by ktime_get_real_seconds(), we need a version without locking. Add a new function __ktime_get_real_seconds() in timekeeping to do this. Reviewed-by: John Stultz <john.stultz@linaro.org> Signed-off-by: DengChao <chao.deng@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2015-12-16genirq/msi: Add msi_domain_populate_irqsMarc Zyngier
To be able to allocate interrupts from the MSI layer down, add a new msi_domain_populate_irqs entry point. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-16genirq/msi: Make the .prepare callback reusableMarc Zyngier
The .prepare callbacks are so far only called from msi_domain_alloc_irqs. In order to reuse that code, split that code and create a msi_domain_prepare_irqs function that the existing code can call into. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>