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2016-12-12kernel/fork: use vfree_atomic() to free thread stackAndrey Ryabinin
vfree() is going to use sleeping lock. Thread stack freed in atomic context, therefore we must use vfree_atomic() here. Link: http://lkml.kernel.org/r/1479474236-4139-6-git-send-email-hch@lst.de Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Joel Fernandes <joelaf@google.com> Cc: Jisheng Zhang <jszhang@marvell.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: John Dias <joaodias@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12prctl: remove one-shot limitation for changing exe linkStanislav Kinsburskiy
This limitation came with the reason to remove "another way for malicious code to obscure a compromised program and masquerade as a benign process" by allowing "security-concious program can use this prctl once during its early initialization to ensure the prctl cannot later be abused for this purpose": http://marc.info/?l=linux-kernel&m=133160684517468&w=2 This explanation doesn't look sufficient. The only thing "exe" link is indicating is the file, used to execve, which is basically nothing and not reliable immediately after process has returned from execve system call. Moreover, to use this feture, all the mappings to previous exe file have to be unmapped and all the new exe file permissions must be satisfied. Which means, that changing exe link is very similar to calling execve on the binary. The need to remove this limitations comes from migration of NFS mount point, which is not accessible during restore and replaced by other file system. Because of this exe link has to be changed twice. [akpm@linux-foundation.org: fix up comment] Link: http://lkml.kernel.org/r/20160927153755.9337.69650.stgit@localhost.localdomain Signed-off-by: Stanislav Kinsburskiy <skinsbursky@virtuozzo.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: John Stultz <john.stultz@linaro.org> Cc: Matt Helsley <matthltc@us.ibm.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12kthread: add __printf attributesNicolas Iooss
When commit fbae2d44aa1d ("kthread: add kthread_create_worker*()") introduced some kthread_create_...() functions which were taking printf-like parametter, it introduced __printf attributes to some functions (e.g. kthread_create_worker()). Nevertheless some new functions were forgotten (they have been detected thanks to -Wmissing-format-attribute warning flag). Add the missing __printf attributes to the newly-introduced functions in order to detect formatting issues at build-time with -Wformat flag. Link: http://lkml.kernel.org/r/20161126193543.22672-1-nicolas.iooss_linux@m4x.org Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-12kprobes/trace: Fix kprobe selftest for newer gccMarcin Nowakowski
Commit 265a5b7ee3eb ("kprobes/trace: Fix kprobe selftest for gcc 4.6") has added __used attribute to kprobe_trace_selftest_target to ensure that the method is listed in kallsyms table. However, even though the method remains in the kernel image, the actual call is optimized away as there are no side effects and the return value is never checked. Add a return value check and a 'noinline' attribute to ensure that an inlined copy of the method is not used by the caller. Also add checks that verify that the kprobe was really hit, as at the moment the tests show positive results despite the test method being optimized away. Finally, add __init annotations to find_trace_probe_file() and kprobe_trace_selftest_target() as they are only called from within an __init method. Link: http://lkml.kernel.org/r/1481293178-3128-2-git-send-email-marcin.nowakowski@imgtec.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-12tracing/kprobes: Add a helper method to return number of probe hitsMarcin Nowakowski
The number of probe hits is stored in a percpu variable and therefore can't be read directly. Add a helper method trace_kprobe_nhit() that performs the required calculation. It will be used in a follow-up commit that changes kprobe selftests to verify the number of probe hits. Link: http://lkml.kernel.org/r/1481293178-3128-1-git-send-email-marcin.nowakowski@imgtec.com Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-12tracing/rb: Init the CPU mask on allocationSebastian Andrzej Siewior
Before commit b32614c03413 ("tracing/rb: Convert to hotplug state machine") the allocated cpumask was initialized to the mask of ONLINE or POSSIBLE CPUs. After the CPU hotplug changes the buffer initialisation moved to trace_rb_cpu_prepare() but I forgot to initially set the cpumask to zero. This is done now. Link: http://lkml.kernel.org/r/20161207133133.hzkcqfllxcdi3joz@linutronix.de Fixes: b32614c03413 ("tracing/rb: Convert to hotplug state machine") Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-12Merge 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 development cycle were: - a large number of call stack dumping/printing improvements: higher robustness, better cross-context dumping, improved output, etc. (Josh Poimboeuf) - vDSO getcpu() performance improvement for future Intel CPUs with the RDPID instruction (Andy Lutomirski) - add two new Intel AVX512 features and the CPUID support infrastructure for it: AVX512IFMA and AVX512VBMI. (Gayatri Kammela, He Chen) - more copy-user unification (Borislav Petkov) - entry code assembly macro simplifications (Alexander Kuleshov) - vDSO C/R support improvements (Dmitry Safonov) - misc fixes and cleanups (Borislav Petkov, Paul Bolle)" * 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) scripts/decode_stacktrace.sh: Fix address line detection on x86 x86/boot/64: Use defines for page size x86/dumpstack: Make stack name tags more comprehensible selftests/x86: Add test_vdso to test getcpu() x86/vdso: Use RDPID in preference to LSL when available x86/dumpstack: Handle NULL stack pointer in show_trace_log_lvl() x86/cpufeatures: Enable new AVX512 cpu features x86/cpuid: Provide get_scattered_cpuid_leaf() x86/cpuid: Cleanup cpuid_regs definitions x86/copy_user: Unify the code by removing the 64-bit asm _copy_*_user() variants x86/unwind: Ensure stack grows down x86/vdso: Set vDSO pointer only after success x86/prctl/uapi: Remove #ifdef for CHECKPOINT_RESTORE x86/unwind: Detect bad stack return address x86/dumpstack: Warn on stack recursion x86/unwind: Warn on bad frame pointer x86/decoder: Use stderr if insn sanity test fails x86/decoder: Use stdout if insn decoder test is successful mm/page_alloc: Remove kernel address exposure in free_reserved_area() x86/dumpstack: Remove raw stack dump ...
2016-12-12Merge branch 'smp-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull hotplug API fix from Ingo Molnar: "Late breaking fix from the v4.9 cycle: fix a hotplug register/ unregister notifier API asymmetry bug that can cause kernel warnings (and worse) with certain Kconfig combinations" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: hotplug: Make register and unregister notifier API symmetric
2016-12-12Merge 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 scheduler changes in this cycle were: - support Intel Turbo Boost Max Technology 3.0 (TBM3) by introducig a notion of 'better cores', which the scheduler will prefer to schedule single threaded workloads on. (Tim Chen, Srinivas Pandruvada) - enhance the handling of asymmetric capacity CPUs further (Morten Rasmussen) - improve/fix load handling when moving tasks between task groups (Vincent Guittot) - simplify and clean up the cputime code (Stanislaw Gruszka) - improve mass fork()ed task spread a.k.a. hackbench speedup (Vincent Guittot) - make struct kthread kmalloc()ed and related fixes (Oleg Nesterov) - add uaccess atomicity debugging (when using access_ok() in the wrong context), under CONFIG_DEBUG_ATOMIC_SLEEP=y (Peter Zijlstra) - implement various fixes, cleanups and other enhancements (Daniel Bristot de Oliveira, Martin Schwidefsky, Rafael J. Wysocki)" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits) sched/core: Use load_avg for selecting idlest group sched/core: Fix find_idlest_group() for fork kthread: Don't abuse kthread_create_on_cpu() in __kthread_create_worker() kthread: Don't use to_live_kthread() in kthread_[un]park() kthread: Don't use to_live_kthread() in kthread_stop() Revert "kthread: Pin the stack via try_get_task_stack()/put_task_stack() in to_live_kthread() function" kthread: Make struct kthread kmalloc'ed x86/uaccess, sched/preempt: Verify access_ok() context sched/x86: Make CONFIG_SCHED_MC_PRIO=y easier to enable sched/x86: Change CONFIG_SCHED_ITMT to CONFIG_SCHED_MC_PRIO x86/sched: Use #include <linux/mutex.h> instead of #include <asm/mutex.h> cpufreq/intel_pstate: Use CPPC to get max performance acpi/bus: Set _OSC for diverse core support acpi/bus: Enable HWP CPPC objects x86/sched: Add SD_ASYM_PACKING flags to x86 ITMT CPU x86/sysctl: Add sysctl for ITMT scheduling feature x86: Enable Intel Turbo Boost Max Technology 3.0 x86/topology: Define x86's arch_update_cpu_topology sched: Extend scheduler's asym packing sched/fair: Clean up the tunable parameter definitions ...
2016-12-12Merge branches 'pm-sleep' and 'powercap'Rafael J. Wysocki
* pm-sleep: PM / sleep: Print active wakeup sources when blocking on wakeup_count reads x86/suspend: fix false positive KASAN warning on suspend/resume PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag PM / sleep: System sleep state selection interface rework PM / hibernate: Verify the consistent of e820 memory map by md5 digest * powercap: powercap / RAPL: Add Knights Mill CPUID powercap/intel_rapl: fix and tidy up error handling powercap/intel_rapl: Track active CPUs internally powercap/intel_rapl: Cleanup duplicated init code powercap/intel rapl: Convert to hotplug state machine powercap/intel_rapl: Propagate error code when registration fails powercap/intel_rapl: Add missing domain data update on hotplug
2016-12-12Merge branch 'pm-cpuidle'Rafael J. Wysocki
* pm-cpuidle: cpuidle: Add a kerneldoc comment to cpuidle_use_deepest_state() cpuidle: fix improper return value on error intel_idle: Convert to hotplug state machine intel_idle: Remove superfluous SMP fuction call MAINTAINERS: Add Jacob Pan as a new intel_idle maintainer MAINTAINERS: Add bug tracking system location entries for cpuidle x86/intel_idle: Add Knights Mill CPUID x86/intel_idle: Add CPU model 0x4a (Atom Z34xx series) thermal/intel_powerclamp: stop sched tick in forced idle thermal/intel_powerclamp: Convert to CPU hotplug state thermal/intel_powerclamp: Convert the kthread to kthread worker API thermal/intel_powerclamp: Remove duplicated code that starts the kthread sched/idle: Add support for tasks that inject idle cpuidle: Allow enforcing deepest idle state selection cpuidle/powernv: staticise powernv_idle_driver cpuidle: dt: assign ->enter_freeze to same as ->enter callback function cpuidle: governors: Remove remaining old module code
2016-12-12Merge branch 'pm-cpufreq'Rafael J. Wysocki
* pm-cpufreq: (51 commits) Documentation: intel_pstate: Document HWP energy/performance hints cpufreq: intel_pstate: Support for energy performance hints with HWP cpufreq: intel_pstate: Add locking around HWP requests cpufreq: ondemand: Set MIN_FREQUENCY_UP_THRESHOLD to 1 cpufreq: intel_pstate: Add Knights Mill CPUID MAINTAINERS: Add bug tracking system location entry for cpufreq cpufreq: dt: Add support for zx296718 cpufreq: acpi-cpufreq: drop rdmsr_on_cpus() usage cpufreq: acpi-cpufreq: Convert to hotplug state machine cpufreq: intel_pstate: fix intel_pstate_exit_perf_limits() prototype cpufreq: intel_pstate: Set EPP/EPB to 0 in performance mode cpufreq: schedutil: Rectify comment in sugov_irq_work() function cpufreq: intel_pstate: increase precision of performance limits cpufreq: intel_pstate: round up min_perf limits cpufreq: Make cpufreq_update_policy() void ACPI / processor: Make acpi_processor_ppc_has_changed() void cpufreq: Avoid using inactive policies cpufreq: intel_pstate: Generic governors support cpufreq: intel_pstate: Request P-states control from SMM if needed cpufreq: dt: Add support for r8a7743 and r8a7745 ...
2016-12-12tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate resultsPavankumar Kondeti
The 's' flag is supposed to indicate that a softirq is running. This can be detected by testing the preempt_count with SOFTIRQ_OFFSET. The current code tests the preempt_count with SOFTIRQ_MASK, which would be true even when softirqs are disabled but not serving a softirq. Link: http://lkml.kernel.org/r/1481300417-3564-1-git-send-email-pkondeti@codeaurora.org Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-12Merge 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: "The tree got pretty big in this development cycle, but the net effect is pretty good: 115 files changed, 673 insertions(+), 1522 deletions(-) The main changes were: - Rework and generalize the mutex code to remove per arch mutex primitives. (Peter Zijlstra) - Add vCPU preemption support: add an interface to query the preemption status of vCPUs and use it in locking primitives - this optimizes paravirt performance. (Pan Xinhui, Juergen Gross, Christian Borntraeger) - Introduce cpu_relax_yield() and remov cpu_relax_lowlatency() to clean up and improve the s390 lock yielding machinery and its core kernel impact. (Christian Borntraeger) - Micro-optimize mutexes some more. (Waiman Long) - Reluctantly add the to-be-deprecated mutex_trylock_recursive() interface on a temporary basis, to give the DRM code more time to get rid of its locking hacks. Any other users will be NAK-ed on sight. (We turned off the deprecation warning for the time being to not pollute the build log.) (Peter Zijlstra) - Improve the rtmutex code a bit, in light of recent long lived bugs/races. (Thomas Gleixner) - Misc fixes, cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/paravirt: Fix bool return type for PVOP_CALL() x86/paravirt: Fix native_patch() locking/ww_mutex: Use relaxed atomics locking/rtmutex: Explain locking rules for rt_mutex_proxy_unlock()/init_proxy_locked() locking/rtmutex: Get rid of RT_MUTEX_OWNER_MASKALL x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted() locking/mutex: Break out of expensive busy-loop on {mutex,rwsem}_spin_on_owner() when owner vCPU is preempted locking/osq: Break out of spin-wait busy waiting loop for a preempted vCPU in osq_lock() Documentation/virtual/kvm: Support the vCPU preemption check x86/xen: Support the vCPU preemption check x86/kvm: Support the vCPU preemption check x86/kvm: Support the vCPU preemption check kvm: Introduce kvm_write_guest_offset_cached() locking/core, x86/paravirt: Implement vcpu_is_preempted(cpu) for KVM and Xen guests locking/spinlocks, s390: Implement vcpu_is_preempted(cpu) locking/core, powerpc: Implement vcpu_is_preempted(cpu) sched/core: Introduce the vcpu_is_preempted(cpu) interface sched/wake_q: Rename WAKE_Q to DEFINE_WAKE_Q locking/core: Provide common cpu_relax_yield() definition locking/mutex: Don't mark mutex_trylock_recursive() as deprecated, temporarily ...
2016-12-12Merge branch 'core-smp-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull SMP bootup updates from Ingo Molnar: "Three changes to unify/standardize some of the bootup message printing in kernel/smp.c between architectures" * 'core-smp-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: kernel/smp: Tell the user we're bringing up secondary CPUs kernel/smp: Make the SMP boot message common on all arches kernel/smp: Define pr_fmt() for smp.c
2016-12-12Merge 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 main RCU changes in this development cycle were: - Miscellaneous fixes, including a change to call_rcu()'s rcu_head alignment check. - Security-motivated list consistency checks, which are disabled by default behind DEBUG_LIST. - Torture-test updates. - Documentation updates, yet again just simple changes" * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: torture: Prevent jitter from delaying build-only runs torture: Remove obsolete files from rcutorture .gitignore rcu: Don't kick unless grace period or request rcu: Make expedited grace periods recheck dyntick idle state torture: Trace long read-side delays rcu: RCU_TRACE enables event tracing as well as debugfs rcu: Remove obsolete comment from __call_rcu() rcu: Remove obsolete rcu_check_callbacks() header comment rcu: Tighten up __call_rcu() rcu_head alignment check Documentation/RCU: Fix minor typo documentation: Present updated RCU guarantee bug: Avoid Kconfig warning for BUG_ON_DATA_CORRUPTION lib/Kconfig.debug: Fix typo in select statement lkdtm: Add tests for struct list corruption bug: Provide toggle for BUG on data corruption list: Split list_del() debug checking into separate function rculist: Consolidate DEBUG_LIST for list_add_rcu() list: Split list_add() debug checking into separate function
2016-12-11sched/core: Use load_avg for selecting idlest groupVincent Guittot
find_idlest_group() only compares the runnable_load_avg when looking for the least loaded group. But on fork intensive use case like hackbench where tasks blocked quickly after the fork, this can lead to selecting the same CPU instead of other CPUs, which have similar runnable load but a lower load_avg. When the runnable_load_avg of 2 CPUs are close, we now take into account the amount of blocked load as a 2nd selection factor. There is now 3 zones for the runnable_load of the rq: - [0 .. (runnable_load - imbalance)]: Select the new rq which has significantly less runnable_load - [(runnable_load - imbalance) .. (runnable_load + imbalance)]: The runnable loads are close so we use load_avg to chose between the 2 rq - [(runnable_load + imbalance) .. ULONG_MAX]: Keep the current rq which has significantly less runnable_load The scale factor that is currently used for comparing runnable_load, doesn't work well with small value. As an example, the use of a scaling factor fails as soon as this_runnable_load == 0 because we always select local rq even if min_runnable_load is only 1, which doesn't really make sense because they are just the same. So instead of scaling factor, we use an absolute margin for runnable_load to detect CPUs with similar runnable_load and we keep using scaling factor for blocked load. For use case like hackbench, this enable the scheduler to select different CPUs during the fork sequence and to spread tasks across the system. Tests have been done on a Hikey board (ARM based octo cores) for several kernel. The result below gives min, max, avg and stdev values of 18 runs with each configuration. The patches depend on the "no missing update_rq_clock()" work. hackbench -P -g 1 ea86cb4b7621 7dc603c9028e v4.8 v4.8+patches min 0.049 0.050 0.051 0,048 avg 0.057 0.057(0%) 0.057(0%) 0,055(+5%) max 0.066 0.068 0.070 0,063 stdev +/-9% +/-9% +/-8% +/-9% More performance numbers here: https://lkml.kernel.org/r/20161203214707.GI20785@codeblueprint.co.uk Tested-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Morten.Rasmussen@arm.com Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dietmar.eggemann@arm.com Cc: kernellwp@gmail.com Cc: umgwanakikbuti@gmail.com Cc: yuyang.du@intel.comc Link: http://lkml.kernel.org/r/1481216215-24651-3-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-11sched/core: Fix find_idlest_group() for forkVincent Guittot
During fork, the utilization of a task is init once the rq has been selected because the current utilization level of the rq is used to set the utilization of the fork task. As the task's utilization is still 0 at this step of the fork sequence, it doesn't make sense to look for some spare capacity that can fit the task's utilization. Furthermore, I can see perf regressions for the test: hackbench -P -g 1 because the least loaded policy is always bypassed and tasks are not spread during fork. With this patch and the fix below, we are back to same performances as for v4.8. The fix below is only a temporary one used for the test until a smarter solution is found because we can't simply remove the test which is useful for others benchmarks | @@ -5708,13 +5708,6 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t | | avg_cost = this_sd->avg_scan_cost; | | - /* | - * Due to large variance we need a large fuzz factor; hackbench in | - * particularly is sensitive here. | - */ | - if ((avg_idle / 512) < avg_cost) | - return -1; | - | time = local_clock(); | | for_each_cpu_wrap(cpu, sched_domain_span(sd), target, wrap) { Tested-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Morten Rasmussen <morten.rasmussen@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: dietmar.eggemann@arm.com Cc: kernellwp@gmail.com Cc: umgwanakikbuti@gmail.com Cc: yuyang.du@intel.comc Link: http://lkml.kernel.org/r/1481216215-24651-2-git-send-email-vincent.guittot@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-11Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-11Merge branch 'linus' into locking/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2016-12-09tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions tooSteven Rostedt (Red Hat)
Currently both the wakeup and irqsoff traces do not handle set_graph_notrace well. The ftrace infrastructure will ignore the return paths of all functions leaving them hanging without an end: # echo '*spin*' > set_graph_notrace # cat trace [...] _raw_spin_lock() { preempt_count_add() { do_raw_spin_lock() { update_rq_clock(); Where the '*spin*' functions should have looked like this: _raw_spin_lock() { preempt_count_add(); do_raw_spin_lock(); } update_rq_clock(); Instead, have the wakeup and irqsoff tracers ignore the functions that are set by the set_graph_notrace like the function_graph tracer does. Move the logic in the function_graph tracer into a header to allow wakeup and irqsoff tracers to use it as well. Cc: Namhyung Kim <namhyung.kim@lge.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-09fgraph: Handle a case where a tracer ignores set_graph_notraceSteven Rostedt (Red Hat)
Both the wakeup and irqsoff tracers can use the function graph tracer when the display-graph option is set. The problem is that they ignore the notrace file, and record the entry of functions that would be ignored by the function_graph tracer. This causes the trace->depth to be recorded into the ring buffer. The set_graph_notrace uses a trick by adding a large negative number to the trace->depth when a graph function is to be ignored. On trace output, the graph function uses the depth to record a stack of functions. But since the depth is negative, it accesses the array with a negative number and causes an out of bounds access that can cause a kernel oops or corrupt data. Have the print functions handle cases where a tracer still records functions even when they are in set_graph_notrace. Also add warnings if the depth is below zero before accessing the array. Note, the function graph logic will still prevent the return of these functions from being recorded, which means that they will be left hanging without a return. For example: # echo '*spin*' > set_graph_notrace # echo 1 > options/display-graph # echo wakeup > current_tracer # cat trace [...] _raw_spin_lock() { preempt_count_add() { do_raw_spin_lock() { update_rq_clock(); Where it should look like: _raw_spin_lock() { preempt_count_add(); do_raw_spin_lock(); } update_rq_clock(); Cc: stable@vger.kernel.org Cc: Namhyung Kim <namhyung.kim@lge.com> Fixes: 29ad23b00474 ("ftrace: Add set_graph_notrace filter") Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-09tracing: Replace kmap with copy_from_user() in trace_marker writingSteven Rostedt (Red Hat)
Instead of using get_user_pages_fast() and kmap_atomic() when writing to the trace_marker file, just allocate enough space on the ring buffer directly, and write into it via copy_from_user(). Writing into the trace_marker file use to allocate a temporary buffer to perform the copy_from_user(), as we didn't want to write into the ring buffer if the copy failed. But as a trace_marker write is suppose to be extremely fast, and allocating memory causes other tracepoints to trigger, Peter Zijlstra suggested using get_user_pages_fast() and kmap_atomic() to keep the user space pages in memory and reading it directly. But Henrik Austad had issues with this because it required taking the mm->mmap_sem and causing long delays with the write. Instead, just allocate the space in the ring buffer and use copy_from_user() directly. If it faults, return -EFAULT and write "<faulted>" into the ring buffer. Link: http://lkml.kernel.org/r/20161208124018.72dd0f86@gandalf.local.home Cc: Ingo Molnar <mingo@kernel.org> Cc: Henrik Austad <henrik@austad.us> Cc: Peter Zijlstra <peterz@infradead.org> Updates: d696b58ca2c3ca "tracing: Do not allocate buffer for trace_marker" Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-09tracing: Allow benchmark to be enabled at early_initcall()Steven Rostedt (Red Hat)
The trace event start up selftests fails when the trace benchmark is enabled, because it is disabled during boot. It really only needs to be disabled before scheduling is set up, as it creates a thread. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-09tracing: Have system enable return error if one of the events failSteven Rostedt (Red Hat)
If one of the events within a system fails to enable when "1" is written to the system "enable" file, it should return an error. Note, some events may still be enabled, but the user should know that something did go wrong. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-09tracing: Do not start benchmark on boot upSteven Rostedt (Red Hat)
Trace events are enabled very early on boot up via the boot command line parameter. The benchmark tool creates a new thread to perform the trace event benchmarking. But at start up, it is called before scheduling is set up and because it creates a new thread before the init thread is created, this crashes the kernel. Have the benchmark fail to register when started via the kernel command line. Also, since the registering of a tracepoint now can handle failure cases, return -ENOMEM instead of warning if the thread cannot be created. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-09tracing: Have the reg function allow to failSteven Rostedt (Red Hat)
Some tracepoints have a registration function that gets enabled when the tracepoint is enabled. There may be cases that the registraction function must fail (for example, can't allocate enough memory). In this case, the tracepoint should also fail to register, otherwise the user would not know why the tracepoint is not working. Cc: David Howells <dhowells@redhat.com> Cc: Seiji Aguchi <seiji.aguchi@hds.com> Cc: Anton Blanchard <anton@samba.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-12-09timekeeping: Use mul_u64_u32_shr() instead of open coding itThomas Gleixner
The resume code must deal with a clocksource delta which is potentially big enough to overflow the 64bit mult. Replace the open coded handling with the proper function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Parit Bhargava <prarit@redhat.com> Cc: Laurent Vivier <lvivier@redhat.com> Cc: "Christopher S. Hall" <christopher.s.hall@intel.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Liav Rehana <liavr@mellanox.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20161208204228.921674404@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-09timekeeping: Get rid of pointless typecastsThomas Gleixner
cycle_t is defined as u64, so casting it to u64 is a pointless and confusing exercise. cycle_t should simply go away and be replaced with a plain u64 to avoid further confusion. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Parit Bhargava <prarit@redhat.com> Cc: Laurent Vivier <lvivier@redhat.com> Cc: "Christopher S. Hall" <christopher.s.hall@intel.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Liav Rehana <liavr@mellanox.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20161208204228.844699737@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-09timekeeping: Make the conversion call chain consistently unsignedThomas Gleixner
Propagating a unsigned value through signed variables and functions makes absolutely no sense and is just prone to (re)introduce subtle signed vs. unsigned issues as happened recently. Clean it up. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Parit Bhargava <prarit@redhat.com> Cc: Laurent Vivier <lvivier@redhat.com> Cc: "Christopher S. Hall" <christopher.s.hall@intel.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Liav Rehana <liavr@mellanox.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/20161208204228.765843099@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-09timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversionThomas Gleixner
The clocksource delta to nanoseconds conversion is using signed math, but the delta is unsigned. This makes the conversion space smaller than necessary and in case of a multiplication overflow the conversion can become negative. The conversion is done with scaled math: s64 nsec_delta = ((s64)clkdelta * clk->mult) >> clk->shift; Shifting a signed integer right obvioulsy preserves the sign, which has interesting consequences: - Time jumps backwards - __iter_div_u64_rem() which is used in one of the calling code pathes will take forever to piecewise calculate the seconds/nanoseconds part. This has been reported by several people with different scenarios: David observed that when stopping a VM with a debugger: "It was essentially the stopped by debugger case. I forget exactly why, but the guest was being explicitly stopped from outside, it wasn't just scheduling lag. I think it was something in the vicinity of 10 minutes stopped." When lifting the stop the machine went dead. The stopped by debugger case is not really interesting, but nevertheless it would be a good thing not to die completely. But this was also observed on a live system by Liav: "When the OS is too overloaded, delta will get a high enough value for the msb of the sum delta * tkr->mult + tkr->xtime_nsec to be set, and so after the shift the nsec variable will gain a value similar to 0xffffffffff000000." Unfortunately this has been reintroduced recently with commit 6bd58f09e1d8 ("time: Add cycles to nanoseconds translation"). It had been fixed a year ago already in commit 35a4933a8959 ("time: Avoid signed overflow in timekeeping_get_ns()"). Though it's not surprising that the issue has been reintroduced because the function itself and the whole call chain uses s64 for the result and the propagation of it. The change in this recent commit is subtle: s64 nsec; - nsec = (d * m + n) >> s: + nsec = d * m + n; + nsec >>= s; d being type of cycle_t adds another level of obfuscation. This wouldn't have happened if the previous change to unsigned computation would have made the 'nsec' variable u64 right away and a follow up patch had cleaned up the whole call chain. There have been patches submitted which basically did a revert of the above patch leaving everything else unchanged as signed. Back to square one. This spawned a admittedly pointless discussion about potential users which rely on the unsigned behaviour until someone pointed out that it had been fixed before. The changelogs of said patches added further confusion as they made finally false claims about the consequences for eventual users which expect signed results. Despite delta being cycle_t, aka. u64, it's very well possible to hand in a signed negative value and the signed computation will happily return the correct result. But nobody actually sat down and analyzed the code which was added as user after the propably unintended signed conversion. Though in sensitive code like this it's better to analyze it proper and make sure that nothing relies on this than hunting the subtle wreckage half a year later. After analyzing all call chains it stands that no caller can hand in a negative value (which actually would work due to the s64 cast) and rely on the signed math to do the right thing. Change the conversion function to unsigned math. The conversion of all call chains is done in a follow up patch. This solves the starvation issue, which was caused by the negative result, but it does not solve the underlying problem. It merily procrastinates it. When the timekeeper update is deferred long enough that the unsigned multiplication overflows, then time going backwards is observable again. It does neither solve the issue of clocksources with a small counter width which will wrap around possibly several times and cause random time stamps to be generated. But those are usually not found on systems used for virtualization, so this is likely a non issue. I took the liberty to claim authorship for this simply because analyzing all callsites and writing the changelog took substantially more time than just making the simple s/s64/u64/ change and ignore the rest. Fixes: 6bd58f09e1d8 ("time: Add cycles to nanoseconds translation") Reported-by: David Gibson <david@gibson.dropbear.id.au> Reported-by: Liav Rehana <liavr@mellanox.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: David Gibson <david@gibson.dropbear.id.au> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Parit Bhargava <prarit@redhat.com> Cc: Laurent Vivier <lvivier@redhat.com> Cc: "Christopher S. Hall" <christopher.s.hall@intel.com> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: John Stultz <john.stultz@linaro.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/20161208204228.688545601@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-08bpf: xdp: Allow head adjustment in XDP progMartin KaFai Lau
This patch allows XDP prog to extend/remove the packet data at the head (like adding or removing header). It is done by adding a new XDP helper bpf_xdp_adjust_head(). It also renames bpf_helper_changes_skb_data() to bpf_helper_changes_pkt_data() to better reflect that XDP prog does not work on skb. This patch adds one "xdp_adjust_head" bit to bpf_prog for the XDP-capable driver to check if the XDP prog requires bpf_xdp_adjust_head() support. The driver can then decide to error out during XDP_SETUP_PROG. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Acked-by: John Fastabend <john.r.fastabend@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-08bpf: fix state equivalenceAlexei Starovoitov
Commmits 57a09bf0a416 ("bpf: Detect identical PTR_TO_MAP_VALUE_OR_NULL registers") and 484611357c19 ("bpf: allow access into map value arrays") by themselves are correct, but in combination they make state equivalence ignore 'id' field of the register state which can lead to accepting invalid program. Fixes: 57a09bf0a416 ("bpf: Detect identical PTR_TO_MAP_VALUE_OR_NULL registers") Fixes: 484611357c19 ("bpf: allow access into map value arrays") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-08kthread: Don't abuse kthread_create_on_cpu() in __kthread_create_worker()Oleg Nesterov
kthread_create_on_cpu() sets KTHREAD_IS_PER_CPU and kthread->cpu, this only makes sense if this kthread can be parked/unparked by cpuhp code. kthread workers never call kthread_parkme() so this has no effect. Change __kthread_create_worker() to simply call kthread_bind(task, cpu). The very fact that kthread_create_on_cpu() doesn't accept a generic fmt shows that it should not be used outside of smpboot.c. Now, the only reason we can not unexport this helper and move it into smpboot.c is that it sets kthread->cpu and struct kthread is not exported. And the only reason we can not kill kthread->cpu is that kthread_unpark() is used by drivers/gpu/drm/amd/scheduler/gpu_scheduler.c and thus we can not turn _unpark into kthread_unpark(struct smp_hotplug_thread *, cpu). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Tested-by: Petr Mladek <pmladek@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Chunming Zhou <David1.Zhou@amd.com> Cc: Roman Pen <roman.penyaev@profitbricks.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20161129175110.GA5342@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-08kthread: Don't use to_live_kthread() in kthread_[un]park()Oleg Nesterov
Now that to_kthread() is always validm change kthread_park() and kthread_unpark() to use it and kill to_live_kthread(). The conversion of kthread_unpark() is trivial. If KTHREAD_IS_PARKED is set then the task has called complete(&self->parked) and there the function cannot race against a concurrent kthread_stop() and exit. kthread_park() is more tricky, because its semantics are not well defined. It returns -ENOSYS if the thread exited but this can never happen and as Roman pointed out kthread_park() can obviously block forever if it would race with the exiting kthread. The usage of kthread_park() in cpuhp code (cpu.c, smpboot.c, stop_machine.c) is fine. It can never see an exiting/exited kthread, smpboot_destroy_threads() clears *ht->store, smpboot_park_thread() checks it is not NULL under the same smpboot_threads_lock. cpuhp_threads and cpu_stop_threads never exit, so other callers are fine too. But it has two more users: - watchdog_park_threads(): The code is actually correct, get_online_cpus() ensures that kthread_park() can't race with itself (note that kthread_park() can't handle this race correctly), but it should not use kthread_park() directly. - drivers/gpu/drm/amd/scheduler/gpu_scheduler.c should not use kthread_park() either. kthread_park() must not be called after amd_sched_fini() which does kthread_stop(), otherwise even to_live_kthread() is not safe because task_struct can be already freed and sched->thread can point to nowhere. The usage of kthread_park/unpark should either be restricted to core code which is properly protected against the exit race or made more robust so it is safe to use it in drivers. To catch eventual exit issues, add a WARN_ON(PF_EXITING) for now. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chunming Zhou <David1.Zhou@amd.com> Cc: Roman Pen <roman.penyaev@profitbricks.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20161129175107.GA5339@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-08kthread: Don't use to_live_kthread() in kthread_stop()Oleg Nesterov
kthread_stop() had to use to_live_kthread() simply because it was not possible to access kthread->exited after the exiting task clears task_struct->vfork_done. Now that to_kthread() is always valid, wake_up_process() + wait_for_completion() can be done ununconditionally. It's not an issue anymore if the task has already issued complete_vfork_done() or died. The exiting task can get the spurious wakeup after mm_release() but this is possible without this change too and is fine; do_task_dead() ensures that this can't make any harm. As a further enhancement this could be converted to task_work_add() later, so ->vfork_done can be avoided completely. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chunming Zhou <David1.Zhou@amd.com> Cc: Roman Pen <roman.penyaev@profitbricks.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20161129175103.GA5336@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-08Revert "kthread: Pin the stack via try_get_task_stack()/put_task_stack() in ↵Oleg Nesterov
to_live_kthread() function" This reverts commit 23196f2e5f5d810578a772785807dcdc2b9fdce9. Now that struct kthread is kmalloc'ed and not longer on the task stack there is no need anymore to pin the stack. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chunming Zhou <David1.Zhou@amd.com> Cc: Roman Pen <roman.penyaev@profitbricks.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20161129175100.GA5333@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-08kthread: Make struct kthread kmalloc'edOleg Nesterov
commit 23196f2e5f5d "kthread: Pin the stack via try_get_task_stack() / put_task_stack() in to_live_kthread() function" is a workaround for the fragile design of struct kthread being allocated on the task stack. struct kthread in its current form should be removed, but this needs cleanups outside of kthread.c. As a first step move struct kthread away from the task stack by making it kmalloc'ed. This allows to access kthread.exited without the magic of trying to pin task stack and the try logic in to_live_kthread(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chunming Zhou <David1.Zhou@amd.com> Cc: Roman Pen <roman.penyaev@profitbricks.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Alex Deucher <alexander.deucher@amd.com> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20161129175057.GA5330@redhat.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-08hotplug: Make register and unregister notifier API symmetricMichal Hocko
Yu Zhao has noticed that __unregister_cpu_notifier only unregisters its notifiers when HOTPLUG_CPU=y while the registration might succeed even when HOTPLUG_CPU=n if MODULE is enabled. This means that e.g. zswap might keep a stale notifier on the list on the manual clean up during the pool tear down and thus corrupt the list. Resulting in the following [ 144.964346] BUG: unable to handle kernel paging request at ffff880658a2be78 [ 144.971337] IP: [<ffffffffa290b00b>] raw_notifier_chain_register+0x1b/0x40 <snipped> [ 145.122628] Call Trace: [ 145.125086] [<ffffffffa28e5cf8>] __register_cpu_notifier+0x18/0x20 [ 145.131350] [<ffffffffa2a5dd73>] zswap_pool_create+0x273/0x400 [ 145.137268] [<ffffffffa2a5e0fc>] __zswap_param_set+0x1fc/0x300 [ 145.143188] [<ffffffffa2944c1d>] ? trace_hardirqs_on+0xd/0x10 [ 145.149018] [<ffffffffa2908798>] ? kernel_param_lock+0x28/0x30 [ 145.154940] [<ffffffffa2a3e8cf>] ? __might_fault+0x4f/0xa0 [ 145.160511] [<ffffffffa2a5e237>] zswap_compressor_param_set+0x17/0x20 [ 145.167035] [<ffffffffa2908d3c>] param_attr_store+0x5c/0xb0 [ 145.172694] [<ffffffffa290848d>] module_attr_store+0x1d/0x30 [ 145.178443] [<ffffffffa2b2b41f>] sysfs_kf_write+0x4f/0x70 [ 145.183925] [<ffffffffa2b2a5b9>] kernfs_fop_write+0x149/0x180 [ 145.189761] [<ffffffffa2a99248>] __vfs_write+0x18/0x40 [ 145.194982] [<ffffffffa2a9a412>] vfs_write+0xb2/0x1a0 [ 145.200122] [<ffffffffa2a9a732>] SyS_write+0x52/0xa0 [ 145.205177] [<ffffffffa2ff4d97>] entry_SYSCALL_64_fastpath+0x12/0x17 This can be even triggered manually by changing /sys/module/zswap/parameters/compressor multiple times. Fix this issue by making unregister APIs symmetric to the register so there are no surprises. Fixes: 47e627bc8c9a ("[PATCH] hotplug: Allow modules to use the cpu hotplug notifiers even if !CONFIG_HOTPLUG_CPU") Reported-and-tested-by: Yu Zhao <yuzhao@google.com> Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: linux-mm@kvack.org Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Streetman <ddstreet@ieee.org> Link: http://lkml.kernel.org/r/20161207135438.4310-1-mhocko@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-07kcov: add missing #include <linux/sched.h>Kefeng Wang
In __sanitizer_cov_trace_pc we use task_struct and fields within it, but as we haven't included <linux/sched.h>, it is not guaranteed to be defined. While we usually happen to acquire the definition through a transitive include, this is fragile (and hasn't been true in the past, causing issues with backports). Include <linux/sched.h> to avoid any fragility. [mark.rutland@arm.com: rewrote changelog] Link: http://lkml.kernel.org/r/1481007384-27529-1-git-send-email-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-07Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "An autogroup nice level adjustment bug fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/autogroup: Fix 64-bit kernel nice level adjustment
2016-12-07Merge 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: "A bogus warning fix, a counter width handling fix affecting certain machines, plus a oneliner hw-enablement patch for Knights Mill CPUs" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Remove invalid warning from list_update_cgroup_even()t perf/x86: Fix full width counter, counter overflow perf/x86/intel: Enable C-state residency events for Knights Mill
2016-12-07Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fixes from Ingo Molnar: "Two rtmutex race fixes (which miraculously never triggered, that we know of), plus two lockdep printk formatting regression fixes" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Fix report formatting locking/rtmutex: Use READ_ONCE() in rt_mutex_owner() locking/rtmutex: Prevent dequeue vs. unlock race locking/selftest: Fix output since KERN_CONT changes
2016-12-07bpf: fix loading of BPF_MAXINSNS sized programsDaniel Borkmann
General assumption is that single program can hold up to BPF_MAXINSNS, that is, 4096 number of instructions. It is the case with cBPF and that limit was carried over to eBPF. When recently testing digest, I noticed that it's actually not possible to feed 4096 instructions via bpf(2). The check for > BPF_MAXINSNS was added back then to bpf_check() in cbd357008604 ("bpf: verifier (add ability to receive verification log)"). However, 09756af46893 ("bpf: expand BPF syscall with program load/unload") added yet another check that comes before that into bpf_prog_load(), but this time bails out already in case of >= BPF_MAXINSNS. Fix it up and perform the check early in bpf_prog_load(), so we can drop the second one in bpf_check(). It makes sense, because also a 0 insn program is useless and we don't want to waste any resources doing work up to bpf_check() point. The existing bpf(2) man page documents E2BIG as the official error for such cases, so just stick with it as well. Fixes: 09756af46893 ("bpf: expand BPF syscall with program load/unload") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-07clocksource: export the clocks_calc_mult_shift to use by timestamp codeMurali Karicheri
The CPSW CPTS driver is capable of doing timestamping on tx/rx packets and requires to know mult and shift factors for timestamp conversion from raw value to nanoseconds (ptp clock). Now these mult and shift factors are calculated manually and provided through DT, which makes very hard to support of a lot number of platforms, especially if CPTS refclk is not the same for some kind of boards and depends on efuse settings (Keystone 2 platforms). Hence, export clocks_calc_mult_shift() to allow drivers like CPSW CPTS (and other ptp drivesr) to benefit from automaitc calculation of mult and shift factors. Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Murali Karicheri <m-karicheri2@ti.com> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-07tracing/rb: Init the CPU mask on allocationSebastian Andrzej Siewior
Before commit b32614c03413 ("tracing/rb: Convert to hotplug state machine") the allocated cpumask was initialized to the mask of online or possible CPUs. After the CPU hotplug changes the buffer initialization moved to trace_rb_cpu_prepare() but the cpumask is allocated with alloc_cpumask() and therefor has random content. As a consequence the cpu buffers are not initialized and a later access dereferences a NULL pointer. Use zalloc_cpumask() instead so trace_rb_cpu_prepare() initializes the buffers properly. Fixes: b32614c03413 ("tracing/rb: Convert to hotplug state machine") Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: rostedt@goodmis.org Link: http://lkml.kernel.org/r/20161207133133.hzkcqfllxcdi3joz@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-06lockdep: Fix report formattingDmitry Vyukov
Since commit: 4bcc595ccd80 ("printk: reinstate KERN_CONT for printing continuation lines") printk() requires KERN_CONT to continue log messages. Lots of printk() in lockdep.c and print_ip_sym() don't have it. As the result lockdep reports are completely messed up. Add missing KERN_CONT and inline print_ip_sym() where necessary. Example of a messed up report: 0-rc5+ #41 Not tainted ------------------------------------------------------- syz-executor0/5036 is trying to acquire lock: ( rtnl_mutex ){+.+.+.} , at: [<ffffffff86b3d6ac>] rtnl_lock+0x1c/0x20 but task is already holding lock: ( &net->packet.sklist_lock ){+.+...} , at: [<ffffffff873541a6>] packet_diag_dump+0x1a6/0x1920 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 ( &net->packet.sklist_lock +.+...} ... Without this patch all scripts that parse kernel bug reports are broken. Signed-off-by: Dmitry Vyukov <dvyukov@google.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> Cc: andreyknvl@google.com Cc: aryabinin@virtuozzo.com Cc: joe@perches.com Cc: syzkaller@googlegroups.com Link: http://lkml.kernel.org/r/1480343083-48731-1-git-send-email-dvyukov@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-06perf/core: Remove invalid warning from list_update_cgroup_even()tDavid Carrillo-Cisneros
The warning introduced in commit: 864c2357ca89 ("perf/core: Do not set cpuctx->cgrp for unscheduled cgroups") assumed that a cgroup switch always precedes list_del_event. This is not the case. Remove warning. Make sure that cpuctx->cgrp is NULL until a cgroup event is sched in or ctx->nr_cgroups == 0. Signed-off-by: David Carrillo-Cisneros <davidcc@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Kan Liang <kan.liang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Nilay Vaish <nilayvaish@gmail.com> Cc: Paul Turner <pjt@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vegard Nossum <vegard.nossum@gmail.com> Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1480841177-27299-1-git-send-email-davidcc@google.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-12-05audit_log_{name,link_denied}: constify struct pathAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>