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2015-10-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Conflicts: net/dsa/slave.c net/dsa/slave.c simply had overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-30Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU fixes from Ingo Molnar: "Two RCU fixes: - work around bug with recent GCC versions. - fix false positive lockdep splat" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rcu: Suppress lockdep false positive for rcp->exp_funnel_mutex rcu: Change _wait_rcu_gp() to work around GCC bug 67055
2015-09-29irq: Export per-cpu irq allocation and de-allocation functionsMaxime Ripard
Some drivers might use the per-cpu interrupts and still might be built as a module. Export request_percpu_irq an free_percpu_irq to these user, which also make it consistent with enable/disable_percpu_irq that were exported. Reported-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-29genirq: Fix the documentation of request_percpu_irqMaxime Ripard
The documentation of request_percpu_irq is confusing and suggest that the interrupt is not enabled at all, while it is actually enabled on the local CPU. Clarify that. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-09-28Merge branch 'for-mingo' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent Pull RCU fixes from Paul E. McKenney, for two regressions introduced in this merge window: - Fix bug with recent GCCs. - Fix false positive lockdep splat. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-27Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Thomas Gleixner: "Another pile of fixes for perf: - Plug overflows and races in the core code - Sanitize the flow of the perf syscall so we error out before handling the more complex and hard to undo setups - Improve and fix Broadwell and Skylake hardware support - Revert a fix which broke what it tried to fix in perf tools - A couple of smaller fixes in various places of perf tools" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf tools: Fix copying of /proc/kcore perf intel-pt: Remove no_force_psb from documentation perf probe: Use existing routine to look for a kernel module by dso->short_name perf/x86: Change test_aperfmperf() and test_intel() to static tools lib traceevent: Fix string handling in heterogeneous arch environments perf record: Avoid infinite loop at buildid processing with no samples perf: Fix races in computing the header sizes perf: Fix u16 overflows perf: Restructure perf syscall point of no return perf/x86/intel: Fix Skylake FRONTEND MSR extrareg mask perf/x86/intel/pebs: Add PEBS frontend profiling for Skylake perf/x86/intel: Make the CYCLE_ACTIVITY.* constraint on Broadwell more specific perf tools: Bool functions shouldn't return -1 tools build: Add test for presence of __get_cpuid() gcc builtin tools build: Add test for presence of numa_num_possible_cpus() in libnuma Revert "perf symbols: Fix mismatched declarations for elf_getphdrnum" perf stat: Fix per-pkg event reporting bug
2015-09-27Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Thomas Gleixner: "A single bug fix for the scheduler to prevent dequeueing of the idle task when setting the cpus allowed mask" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Fix crash trying to dequeue/enqueue the idle thread
2015-09-27Merge branch 'locking-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking fix from Thomas Gleixner: "A single bugfix for lockdep to preserve the pinning counter when rebuilding the lock stack" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/lockdep: Fix hlock->pin_count reset on lock stack rebuilds
2015-09-23locking/lockdep: Fix hlock->pin_count reset on lock stack rebuildsPeter Zijlstra
Various people reported hitting the "unpinning an unpinned lock" warning. As it turns out there are 2 places where we take a lock out of the middle of a stack, and in those cases it would fail to preserve the pin_count when rebuilding the lock stack. Reported-by: Sasha Levin <sasha.levin@oracle.com> Reported-by: Tim Spriggs <tspriggs@apple.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davej@codemonkey.org.uk Link: http://lkml.kernel.org/r/20150916141040.GA11639@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-22userfaultfd: revert "userfaultfd: waitqueue: add nr wake parameter to ↵Andrea Arcangeli
__wake_up_locked_key" This reverts commit 51360155eccb907ff8635bd10fc7de876408c2e0 and adapts fs/userfaultfd.c to use the old version of that function. It didn't look robust to call __wake_up_common with "nr == 1" when we absolutely require wakeall semantics, but we've full control of what we insert in the two waitqueue heads of the blocked userfaults. No exclusive waitqueue risks to be inserted into those two waitqueue heads so we can as well stick to "nr == 1" of the old code and we can rely purely on the fact no waitqueue inserted in one of the two waitqueue heads we must enforce as wakeall, has wait->flags WQ_FLAG_EXCLUSIVE set. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Shuah Khan <shuahkh@osg.samsung.com> Cc: Thierry Reding <treding@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-22Merge branch 'for-4.3-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "The threadgroup locking changes which went in during 4.2 devel cycle added write locking of a percpu_rwsem in cgroup task migration path; unfortunately, that involved expedited rcu syncing which turned out to be too slow and heavy for certain workloads. The patchset which is dependent on this one didn't get committed during that devel cycle, so these two patches can be reverted safely. Oleg reworked percpu_rwsem for 4.4 so that the writer path is a lot lighter. The reported issue goes away with Oleg's reworked percpu_rwsem and I'll reapply these patches on the for-4.4 branch so that they can land together with Oleg's changes" * 'for-4.3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: Revert "sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem" Revert "cgroup: simplify threadgroup locking"
2015-09-21rcu: Suppress lockdep false positive for rcp->exp_funnel_mutexPaul E. McKenney
In kernels built with CONFIG_PREEMPT=y, synchronize_rcu_expedited() invokes synchronize_sched_expedited() while holding RCU-preempt's root rcu_node structure's ->exp_funnel_mutex, which is acquired after the rcu_data structure's ->exp_funnel_mutex. The first thing that synchronize_sched_expedited() will do is acquire RCU-sched's rcu_data structure's ->exp_funnel_mutex. There is no danger of an actual deadlock because the locking order is always from RCU-preempt's expedited mutexes to those of RCU-sched. Unfortunately, lockdep considers both rcu_data structures' ->exp_funnel_mutex to be in the same lock class and therefore reports a deadlock cycle. This commit silences this false positive by placing RCU-sched's rcu_data structures' ->exp_funnel_mutex locks into their own lock class. Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2015-09-18Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM fixes from Paolo Bonzini: "Mostly stable material, a lot of ARM fixes" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (22 commits) sched: access local runqueue directly in single_task_running arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS' arm64: KVM: Remove all traces of the ThumbEE registers arm: KVM: Disable virtual timer even if the guest is not using it arm64: KVM: Disable virtual timer even if the guest is not using it arm/arm64: KVM: vgic: Check for !irqchip_in_kernel() when mapping resources KVM: s390: Replace incorrect atomic_or with atomic_andnot arm: KVM: Fix incorrect device to IPA mapping arm64: KVM: Fix user access for debug registers KVM: vmx: fix VPID is 0000H in non-root operation KVM: add halt_attempted_poll to VCPU stats kvm: fix zero length mmio searching kvm: fix double free for fast mmio eventfd kvm: factor out core eventfd assign/deassign logic kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd KVM: make the declaration of functions within 80 characters KVM: arm64: add workaround for Cortex-A57 erratum #852523 KVM: fix polling for guest halt continued even if disable it arm/arm64: KVM: Fix PSCI affinity info return value for non valid cores arm64: KVM: set {v,}TCR_EL2 RES1 bits ...
2015-09-18Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq updates from Thomas Gleixner: "This is a rather large update post rc1 due to the final steps of cleanups and API changes which had to wait for the preparatory patches to hit your tree. - Regression fixes for ARM GIC irqchips - Regression fixes and lockdep anotations for renesas irq chips - The leftovers of the cleanup and preparatory patches which have been ignored by maintainers - Final conversions of the newly merged users of obsolete APIs - Final removal of obsolete APIs - Final removal of ARM artifacts which had been introduced during the conversion of ARM to the generic interrupt code. - Final split of the irq_data into chip specific and common data to reflect the needs of hierarchical irq domains. - Treewide removal of the first argument of interrupt flow handlers, i.e. the irq number, which is not used by the majority of handlers and simple to retrieve from the other argument the irq descriptor. - A few comment updates and build warning fixes" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) arm64: Remove ununsed set_irq_flags ARM: Remove ununsed set_irq_flags sh: Kill off set_irq_flags usage irqchip: Kill off set_irq_flags usage gpu/drm: Kill off set_irq_flags usage genirq: Remove irq argument from irq flow handlers genirq: Move field 'msi_desc' from irq_data into irq_common_data genirq: Move field 'affinity' from irq_data into irq_common_data genirq: Move field 'handler_data' from irq_data into irq_common_data genirq: Move field 'node' from irq_data into irq_common_data irqchip/gic-v3: Use IRQD_FORWARDED_TO_VCPU flag irqchip/gic: Use IRQD_FORWARDED_TO_VCPU flag genirq: Provide IRQD_FORWARDED_TO_VCPU status flag genirq: Simplify irq_data_to_desc() genirq: Remove __irq_set_handler_locked() pinctrl/pistachio: Use irq_set_handler_locked gpio: vf610: Use irq_set_handler_locked powerpc/mpc8xx: Use irq_set_handler_locked() powerpc/ipic: Use irq_set_handler_locked() powerpc/cpm2: Use irq_set_handler_locked() ...
2015-09-18sched: access local runqueue directly in single_task_runningDominik Dingel
Commit 2ee507c47293 ("sched: Add function single_task_running to let a task check if it is the only task running on a cpu") referenced the current runqueue with the smp_processor_id. When CONFIG_DEBUG_PREEMPT is enabled, that is only allowed if preemption is disabled or the currrent task is bound to the local cpu (e.g. kernel worker). With commit f78195129963 ("kvm: add halt_poll_ns module parameter") KVM calls single_task_running. If CONFIG_DEBUG_PREEMPT is enabled that generates a lot of kernel messages. To avoid adding preemption in that cases, as it would limit the usefulness, we change single_task_running to access directly the cpu local runqueue. Cc: Tim Chen <tim.c.chen@linux.intel.com> Suggested-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Fixes: 2ee507c472939db4b146d545352b8a7c79ef47f8 Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-09-18perf: Fix races in computing the header sizesPeter Zijlstra
There are two races with the current code: - Another event can join the group and compute a larger header_size concurrently, if the smaller store wins we'll have an incorrect header_size set. - We compute the header_size after the event becomes active, therefore its possible to use the size before its computed. Remedy the first by moving the computation inside the ctx::mutex lock, and the second by placing it _before_ perf_install_in_context(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-18perf: Fix u16 overflowsPeter Zijlstra
Vince reported that its possible to overflow the various size fields and get weird stuff if you stick too many events in a group. Put a lid on this by requiring the fixed record size not exceed 16k. This is still a fair amount of events (silly amount really) and leaves plenty room for callchains and stack dwarves while also avoiding overflowing the u16 variables. Reported-by: Vince Weaver <vincent.weaver@maine.edu> 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: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-18perf: Restructure perf syscall point of no returnPeter Zijlstra
The exclusive_event_installable() stuff only works because its exclusive with the grouping bits. Rework the code such that there is a sane place to error out before we go do things we cannot undo. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-18sched: Fix crash trying to dequeue/enqueue the idle threadPeter Zijlstra
Sasha reports that his virtual machine tries to schedule the idle thread since commit 6c37067e2786 ("sched: Change the sched_class::set_cpus_allowed() calling context"). Hit trace shows this happening from idle_thread_get()->init_idle(), which is the _second_ init_idle() invocation on that task_struct, the first being done through idle_init()->fork_idle(). (this code is insane...) Because we call init_idle() twice in a row, its ->sched_class == &idle_sched_class and ->on_rq = TASK_ON_RQ_QUEUED. This means do_set_cpus_allowed() think we're queued and will call dequeue_task(), which is implemented with BUG() for the idle class, seeing how dequeueing the idle task is a daft thing. Aside of the whole insanity of calling init_idle() _twice_, change the code to call set_cpus_allowed_common() instead as this is 'obviously' before the idle task gets ran etc.. 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: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 6c37067e2786 ("sched: Change the sched_class::set_cpus_allowed() calling context") Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-17Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: "A fix for an abs()/abs64() bug that caused too slow NTP convergence on 32-bit kernels, plus a removal of an obsolete clockevents driver facility after all users got converted during the merge window" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clockevents: Remove unused set_mode() callback time: Fix timekeeping_freqadjust()'s incorrect use of abs() instead of abs64()
2015-09-17Merge 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: "A migrate_tasks() locking fix, and a late-coming nohz change plus a nohz debug check" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: 'Annotate' migrate_tasks() nohz: Assert existing housekeepers when nohz full enabled nohz: Affine unpinned timers to housekeepers
2015-09-17Merge 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: "Spinlock performance regression fix, plus documentation fixes" * 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/static_keys: Fix up the static keys documentation locking/qspinlock/x86: Only emit the test-and-set fallback when building guest support locking/qspinlock/x86: Fix performance regression under unaccelerated VMs locking/static_keys: Fix a silly typo
2015-09-16Revert "sched, cgroup: replace signal_struct->group_rwsem with a global ↵Tejun Heo
percpu_rwsem" This reverts commit d59cfc09c32a2ae31f1c3bc2983a0cd79afb3f14. d59cfc09c32a ("sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem") and b5ba75b5fc0e ("cgroup: simplify threadgroup locking") changed how cgroup synchronizes against task fork and exits so that it uses global percpu_rwsem instead of per-process rwsem; unfortunately, the write [un]lock paths of percpu_rwsem always involve synchronize_rcu_expedited() which turned out to be too expensive. Improvements for percpu_rwsem are scheduled to be merged in the coming v4.4-rc1 merge window which alleviates this issue. For now, revert the two commits to restore per-process rwsem. They will be re-applied for the v4.4-rc1 merge window. Signed-off-by: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/g/55F8097A.7000206@de.ibm.com Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org # v4.2+
2015-09-16Revert "cgroup: simplify threadgroup locking"Tejun Heo
This reverts commit b5ba75b5fc0e8404e2c50cb68f39bb6a53fc916f. d59cfc09c32a ("sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem") and b5ba75b5fc0e ("cgroup: simplify threadgroup locking") changed how cgroup synchronizes against task fork and exits so that it uses global percpu_rwsem instead of per-process rwsem; unfortunately, the write [un]lock paths of percpu_rwsem always involve synchronize_rcu_expedited() which turned out to be too expensive. Improvements for percpu_rwsem are scheduled to be merged in the coming v4.4-rc1 merge window which alleviates this issue. For now, revert the two commits to restore per-process rwsem. They will be re-applied for the v4.4-rc1 merge window. Signed-off-by: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/g/55F8097A.7000206@de.ibm.com Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: stable@vger.kernel.org # v4.2+
2015-09-16genirq: Remove irq argument from irq flow handlersThomas Gleixner
Most interrupt flow handlers do not use the irq argument. Those few which use it can retrieve the irq number from the irq descriptor. Remove the argument. Search and replace was done with coccinelle and some extra helper scripts around it. Thanks to Julia for her help! Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Jiang Liu <jiang.liu@linux.intel.com>
2015-09-16genirq: Move field 'msi_desc' from irq_data into irq_common_dataJiang Liu
MSI descriptors are per-irq instead of per irqchip, so move it into struct irq_common_data. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/1433145945-789-35-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16genirq: Move field 'affinity' from irq_data into irq_common_dataJiang Liu
Irq affinity mask is per-irq instead of per irqchip, so move it into struct irq_common_data. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/1433303281-27688-1-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16genirq: Move field 'handler_data' from irq_data into irq_common_dataJiang Liu
Handler data (handler_data) is per-irq instead of per irqchip, so move it into struct irq_common_data. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marc Zyngier <marc.zyngier@arm.com> Link: http://lkml.kernel.org/r/1433145945-789-13-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-16genirq: Move field 'node' from irq_data into irq_common_dataJiang Liu
NUMA node information is per-irq instead of per-irqchip, so move it into struct irq_common_data. Also use CONFIG_NUMA to guard irq_common_data.node. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Link: http://lkml.kernel.org/r/1433145945-789-8-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-09-14clockevents: Remove unused set_mode() callbackViresh Kumar
All users are migrated to the per-state callbacks, get rid of the unused interface and the core support code. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: linaro-kernel@lists.linaro.org Cc: John Stultz <john.stultz@linaro.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/fd60de14cf6d125489c031207567bb255ad946f6.1441943991.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-13time: Fix timekeeping_freqadjust()'s incorrect use of abs() instead of abs64()John Stultz
The internal clocksteering done for fine-grained error correction uses a logarithmic approximation, so any time adjtimex() adjusts the clock steering, timekeeping_freqadjust() quickly approximates the correct clock frequency over a series of ticks. Unfortunately, the logic in timekeeping_freqadjust(), introduced in commit: dc491596f639 ("timekeeping: Rework frequency adjustments to work better w/ nohz") used the abs() function with a s64 error value to calculate the size of the approximated adjustment to be made. Per include/linux/kernel.h: "abs() should not be used for 64-bit types (s64, u64, long long) - use abs64()". Thus on 32-bit platforms, this resulted in the clocksteering to take a quite dampended random walk trying to converge on the proper frequency, which caused the adjustments to be made much slower then intended (most easily observed when large adjustments are made). This patch fixes the issue by using abs64() instead. Reported-by: Nuno Gonçalves <nunojpg@gmail.com> Tested-by: Nuno Goncalves <nunojpg@gmail.com> Signed-off-by: John Stultz <john.stultz@linaro.org> Cc: <stable@vger.kernel.org> # v3.17+ Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1441840051-20244-1-git-send-email-john.stultz@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-12Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge fourth patch-bomb from Andrew Morton: - sys_membarier syscall - seq_file interface changes - a few misc fixups * emailed patches from Andrew Morton <akpm@linux-foundation.org>: revert "ocfs2/dlm: use list_for_each_entry instead of list_for_each" mm/early_ioremap: add explicit #include of asm/early_ioremap.h fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void selftests: enhance membarrier syscall test selftests: add membarrier syscall test sys_membarrier(): system-wide memory barrier (generic, x86) MODSIGN: fix a compilation warning in extract-cert
2015-09-12Merge tag 'pm+acpi-4.3-rc1-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management and ACPI updates from Rafael Wysocki: "These are mostly fixes and cleanups on top of the previous PM+ACPI pull request (cpufreq core and drivers, cpuidle, generic power domains framework). Some of them didn't make to that pull request and some fix issues introduced by it. The only really new thing is the support for suspend frequency in the cpufreq-dt driver, but it is needed to fix an issue with Exynos platforms. Specifics: - build fix for the new Mediatek MT8173 cpufreq driver (Guenter Roeck). - generic power domains framework fixes (power on error code path, subdomain removal) and cleanup of a deprecated API user (Geert Uytterhoeven, Jon Hunter, Ulf Hansson). - cpufreq-dt driver fixes including two fixes for bugs related to the new Operating Performance Points Device Tree bindings introduced recently (Viresh Kumar). - suspend frequency support for the cpufreq-dt driver (Bartlomiej Zolnierkiewicz, Viresh Kumar). - cpufreq core cleanups (Viresh Kumar). - intel_pstate driver fixes (Chen Yu, Kristen Carlson Accardi). - additional sanity check in the cpuidle core (Xunlei Pang). - fix for a comment related to CPU power management (Lina Iyer)" * tag 'pm+acpi-4.3-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: intel_pstate: fix PCT_TO_HWP macro intel_pstate: Fix user input of min/max to legal policy region PM / OPP: Return suspend_opp only if it is enabled cpufreq-dt: add suspend frequency support cpufreq: allow cpufreq_generic_suspend() to work without suspend frequency PM / OPP: add dev_pm_opp_get_suspend_opp() helper staging: board: Migrate away from __pm_genpd_name_add_device() cpufreq: Use __func__ to print function's name cpufreq: staticize cpufreq_cpu_get_raw() PM / Domains: Ensure subdomain is not in use before removing cpufreq: Add ARM_MT8173_CPUFREQ dependency on THERMAL cpuidle/coupled: Add sanity check for safe_state_index PM / Domains: Try power off masters in error path of __pm_genpd_poweron() cpufreq: dt: Tolerance applies on both sides of target voltage cpufreq: dt: Print error on failing to mark OPPs as shared cpufreq: dt: Check OPP count before marking them shared kernel/cpu_pm: fix cpu_cluster_pm_exit comment
2015-09-11sys_membarrier(): system-wide memory barrier (generic, x86)Mathieu Desnoyers
Here is an implementation of a new system call, sys_membarrier(), which executes a memory barrier on all threads running on the system. It is implemented by calling synchronize_sched(). It can be used to distribute the cost of user-space memory barriers asymmetrically by transforming pairs of memory barriers into pairs consisting of sys_membarrier() and a compiler barrier. For synchronization primitives that distinguish between read-side and write-side (e.g. userspace RCU [1], rwlocks), the read-side can be accelerated significantly by moving the bulk of the memory barrier overhead to the write-side. The existing applications of which I am aware that would be improved by this system call are as follows: * Through Userspace RCU library (http://urcu.so) - DNS server (Knot DNS) https://www.knot-dns.cz/ - Network sniffer (http://netsniff-ng.org/) - Distributed object storage (https://sheepdog.github.io/sheepdog/) - User-space tracing (http://lttng.org) - Network storage system (https://www.gluster.org/) - Virtual routers (https://events.linuxfoundation.org/sites/events/files/slides/DPDK_RCU_0MQ.pdf) - Financial software (https://lkml.org/lkml/2015/3/23/189) Those projects use RCU in userspace to increase read-side speed and scalability compared to locking. Especially in the case of RCU used by libraries, sys_membarrier can speed up the read-side by moving the bulk of the memory barrier cost to synchronize_rcu(). * Direct users of sys_membarrier - core dotnet garbage collector (https://github.com/dotnet/coreclr/issues/198) Microsoft core dotnet GC developers are planning to use the mprotect() side-effect of issuing memory barriers through IPIs as a way to implement Windows FlushProcessWriteBuffers() on Linux. They are referring to sys_membarrier in their github thread, specifically stating that sys_membarrier() is what they are looking for. To explain the benefit of this scheme, let's introduce two example threads: Thread A (non-frequent, e.g. executing liburcu synchronize_rcu()) Thread B (frequent, e.g. executing liburcu rcu_read_lock()/rcu_read_unlock()) In a scheme where all smp_mb() in thread A are ordering memory accesses with respect to smp_mb() present in Thread B, we can change each smp_mb() within Thread A into calls to sys_membarrier() and each smp_mb() within Thread B into compiler barriers "barrier()". Before the change, we had, for each smp_mb() pairs: Thread A Thread B previous mem accesses previous mem accesses smp_mb() smp_mb() following mem accesses following mem accesses After the change, these pairs become: Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses As we can see, there are two possible scenarios: either Thread B memory accesses do not happen concurrently with Thread A accesses (1), or they do (2). 1) Non-concurrent Thread A vs Thread B accesses: Thread A Thread B prev mem accesses sys_membarrier() follow mem accesses prev mem accesses barrier() follow mem accesses In this case, thread B accesses will be weakly ordered. This is OK, because at that point, thread A is not particularly interested in ordering them with respect to its own accesses. 2) Concurrent Thread A vs Thread B accesses Thread A Thread B prev mem accesses prev mem accesses sys_membarrier() barrier() follow mem accesses follow mem accesses In this case, thread B accesses, which are ensured to be in program order thanks to the compiler barrier, will be "upgraded" to full smp_mb() by synchronize_sched(). * Benchmarks On Intel Xeon E5405 (8 cores) (one thread is calling sys_membarrier, the other 7 threads are busy looping) 1000 non-expedited sys_membarrier calls in 33s =3D 33 milliseconds/call. * User-space user of this system call: Userspace RCU library Both the signal-based and the sys_membarrier userspace RCU schemes permit us to remove the memory barrier from the userspace RCU rcu_read_lock() and rcu_read_unlock() primitives, thus significantly accelerating them. These memory barriers are replaced by compiler barriers on the read-side, and all matching memory barriers on the write-side are turned into an invocation of a memory barrier on all active threads in the process. By letting the kernel perform this synchronization rather than dumbly sending a signal to every process threads (as we currently do), we diminish the number of unnecessary wake ups and only issue the memory barriers on active threads. Non-running threads do not need to execute such barrier anyway, because these are implied by the scheduler context switches. Results in liburcu: Operations in 10s, 6 readers, 2 writers: memory barriers in reader: 1701557485 reads, 2202847 writes signal-based scheme: 9830061167 reads, 6700 writes sys_membarrier: 9952759104 reads, 425 writes sys_membarrier (dyn. check): 7970328887 reads, 425 writes The dynamic sys_membarrier availability check adds some overhead to the read-side compared to the signal-based scheme, but besides that, sys_membarrier slightly outperforms the signal-based scheme. However, this non-expedited sys_membarrier implementation has a much slower grace period than signal and memory barrier schemes. Besides diminishing the number of wake-ups, one major advantage of the membarrier system call over the signal-based scheme is that it does not need to reserve a signal. This plays much more nicely with libraries, and with processes injected into for tracing purposes, for which we cannot expect that signals will be unused by the application. An expedited version of this system call can be added later on to speed up the grace period. Its implementation will likely depend on reading the cpu_curr()->mm without holding each CPU's rq lock. This patch adds the system call to x86 and to asm-generic. [1] http://urcu.so membarrier(2) man page: MEMBARRIER(2) Linux Programmer's Manual MEMBARRIER(2) NAME membarrier - issue memory barriers on a set of threads SYNOPSIS #include <linux/membarrier.h> int membarrier(int cmd, int flags); DESCRIPTION The cmd argument is one of the following: MEMBARRIER_CMD_QUERY Query the set of supported commands. It returns a bitmask of supported commands. MEMBARRIER_CMD_SHARED Execute a memory barrier on all threads running on the system. Upon return from system call, the caller thread is ensured that all running threads have passed through a state where all memory accesses to user-space addresses match program order between entry to and return from the system call (non-running threads are de facto in such a state). This covers threads from all pro=E2=80=90 cesses running on the system. This command returns 0. The flags argument needs to be 0. For future extensions. All memory accesses performed in program order from each targeted thread is guaranteed to be ordered with respect to sys_membarrier(). If we use the semantic "barrier()" to represent a compiler barrier forcing memory accesses to be performed in program order across the barrier, and smp_mb() to represent explicit memory barriers forcing full memory ordering across the barrier, we have the following ordering table for each pair of barrier(), sys_membarrier() and smp_mb(): The pair ordering is detailed as (O: ordered, X: not ordered): barrier() smp_mb() sys_membarrier() barrier() X X O smp_mb() X O O sys_membarrier() O O O RETURN VALUE On success, these system calls return zero. On error, -1 is returned, and errno is set appropriately. For a given command, with flags argument set to 0, this system call is guaranteed to always return the same value until reboot. ERRORS ENOSYS System call is not implemented. EINVAL Invalid arguments. Linux 2015-04-15 MEMBARRIER(2) Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Nicholas Miell <nmiell@comcast.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Stephen Hemminger <stephen@networkplumber.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: David Howells <dhowells@redhat.com> Cc: Pranith Kumar <bobby.prani@gmail.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Shuah Khan <shuahkh@osg.samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-11Merge branches 'pm-cpu', 'pm-cpuidle' and 'pm-domains'Rafael J. Wysocki
* pm-cpu: kernel/cpu_pm: fix cpu_cluster_pm_exit comment * pm-cpuidle: cpuidle/coupled: Add sanity check for safe_state_index * pm-domains: staging: board: Migrate away from __pm_genpd_name_add_device() PM / Domains: Ensure subdomain is not in use before removing PM / Domains: Try power off masters in error path of __pm_genpd_poweron()
2015-09-11sched: 'Annotate' migrate_tasks()Wanpeng Li
Kernel testing triggered this warning: | WARNING: CPU: 0 PID: 13 at kernel/sched/core.c:1156 do_set_cpus_allowed+0x7e/0x80() | Modules linked in: | CPU: 0 PID: 13 Comm: migration/0 Not tainted 4.2.0-rc1-00049-g25834c7 #2 | Call Trace: | dump_stack+0x4b/0x75 | warn_slowpath_common+0x8b/0xc0 | warn_slowpath_null+0x22/0x30 | do_set_cpus_allowed+0x7e/0x80 | cpuset_cpus_allowed_fallback+0x7c/0x170 | select_fallback_rq+0x221/0x280 | migration_call+0xe3/0x250 | notifier_call_chain+0x53/0x70 | __raw_notifier_call_chain+0x1e/0x30 | cpu_notify+0x28/0x50 | take_cpu_down+0x22/0x40 | multi_cpu_stop+0xd5/0x140 | cpu_stopper_thread+0xbc/0x170 | smpboot_thread_fn+0x174/0x2f0 | kthread+0xc4/0xe0 | ret_from_kernel_thread+0x21/0x30 As Peterz pointed out: | So the normal rules for changing task_struct::cpus_allowed are holding | both pi_lock and rq->lock, such that holding either stabilizes the mask. | | This is so that wakeup can happen without rq->lock and load-balance | without pi_lock. | | From this we already get the relaxation that we can omit acquiring | rq->lock if the task is not on the rq, because in that case | load-balancing will not apply to it. | | ** these are the rules currently tested in do_set_cpus_allowed() ** | | Now, since __set_cpus_allowed_ptr() uses task_rq_lock() which | unconditionally acquires both locks, we could get away with holding just | rq->lock when on_rq for modification because that'd still exclude | __set_cpus_allowed_ptr(), it would also work against | __kthread_bind_mask() because that assumes !on_rq. | | That said, this is all somewhat fragile. | | Now, I don't think dropping rq->lock is quite as disastrous as it | usually is because !cpu_active at this point, which means load-balance | will not interfere, but that too is somewhat fragile. | | So we end up with a choice of two fragile.. This patch fixes it by following the rules for changing task_struct::cpus_allowed with both pi_lock and rq->lock held. Reported-by: kernel test robot <ying.huang@intel.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> [ Modified changelog and patch. ] 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> Link: http://lkml.kernel.org/r/BLU436-SMTP1660820490DE202E3934ED3806E0@phx.gbl Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-11locking/qspinlock/x86: Fix performance regression under unaccelerated VMsPeter Zijlstra
Dave ran into horrible performance on a VM without PARAVIRT_SPINLOCKS set and Linus noted that the test-and-set implementation was retarded. One should spin on the variable with a load, not a RMW. While there, remove 'queued' from the name, as the lock isn't queued at all, but a simple test-and-set. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reported-by: Dave Chinner <david@fromorbit.com> Tested-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <Waiman.Long@hp.com> Cc: stable@vger.kernel.org # v4.2+ Link: http://lkml.kernel.org/r/20150904152523.GR18673@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-09-11Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge third patch-bomb from Andrew Morton: - even more of the rest of MM - lib/ updates - checkpatch updates - small changes to a few scruffy filesystems - kmod fixes/cleanups - kexec updates - a dma-mapping cleanup series from hch * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (81 commits) dma-mapping: consolidate dma_set_mask dma-mapping: consolidate dma_supported dma-mapping: cosolidate dma_mapping_error dma-mapping: consolidate dma_{alloc,free}_noncoherent dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent} mm: use vma_is_anonymous() in create_huge_pmd() and wp_huge_pmd() mm: make sure all file VMAs have ->vm_ops set mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff() mm: mark most vm_operations_struct const namei: fix warning while make xmldocs caused by namei.c ipc: convert invalid scenarios to use WARN_ON zlib_deflate/deftree: remove bi_reverse() lib/decompress_unlzma: Do a NULL check for pointer lib/decompressors: use real out buf size for gunzip with kernel fs/affs: make root lookup from blkdev logical size sysctl: fix int -> unsigned long assignments in INT_MIN case kexec: export KERNEL_IMAGE_SIZE to vmcoreinfo kexec: align crash_notes allocation to make it be inside one physical page kexec: remove unnecessary test in kimage_alloc_crash_control_pages() kexec: split kexec_load syscall from kexec core code ...
2015-09-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull networking fixes from David Miller: 1) Fix out-of-bounds array access in netfilter ipset, from Jozsef Kadlecsik. 2) Use correct free operation on netfilter conntrack templates, from Daniel Borkmann. 3) Fix route leak in SCTP, from Marcelo Ricardo Leitner. 4) Fix sizeof(pointer) in mac80211, from Thierry Reding. 5) Fix cache pointer comparison in ip6mr leading to missed unlock of mrt_lock. From Richard Laing. 6) rds_conn_lookup() needs to consider network namespace in key comparison, from Sowmini Varadhan. 7) Fix deadlock in TIPC code wrt broadcast link wakeups, from Kolmakov Dmitriy. 8) Fix fd leaks in bpf syscall, from Daniel Borkmann. 9) Fix error recovery when installing ipv6 multipath routes, we would delete the old route before we would know if we could fully commit to the new set of nexthops. Fix from Roopa Prabhu. 10) Fix run-time suspend problems in r8152, from Hayes Wang. 11) In fec, don't program the MAC address into the chip when the clocks are gated off. From Fugang Duan. 12) Fix poll behavior for netlink sockets when using rx ring mmap, from Daniel Borkmann. 13) Don't allocate memory with GFP_KERNEL from get_stats64 in r8169 driver, from Corinna Vinschen. 14) In TCP Cubic congestion control, handle idle periods better where we are application limited, in order to keep cwnd from growing out of control. From Eric Dumzet. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits) tcp_cubic: better follow cubic curve after idle period tcp: generate CA_EVENT_TX_START on data frames xen-netfront: respect user provided max_queues xen-netback: respect user provided max_queues r8169: Fix sleeping function called during get_stats64, v2 ether: add IEEE 1722 ethertype - TSN netlink, mmap: fix edge-case leakages in nf queue zero-copy netlink, mmap: don't walk rx ring on poll if receive queue non-empty cxgb4: changes for new firmware 1.14.4.0 net: fec: add netif status check before set mac address r8152: fix the runtime suspend issues r8152: split DRIVER_VERSION ipv6: fix ifnullfree.cocci warnings add microchip LAN88xx phy driver stmmac: fix check for phydev being open net: qlcnic: delete redundant memsets net: mv643xx_eth: use kzalloc net: jme: use kzalloc() instead of kmalloc+memset net: cavium: liquidio: use kzalloc in setup_glist() net: ipv6: use common fib_default_rule_pref ...
2015-09-10sysctl: fix int -> unsigned long assignments in INT_MIN caseIlya Dryomov
The following if (val < 0) *lvalp = (unsigned long)-val; is incorrect because the compiler is free to assume -val to be positive and use a sign-extend instruction for extending the bit pattern. This is a problem if val == INT_MIN: # echo -2147483648 >/proc/sys/dev/scsi/logging_level # cat /proc/sys/dev/scsi/logging_level -18446744071562067968 Cast to unsigned long before negation - that way we first sign-extend and then negate an unsigned, which is well defined. With this: # cat /proc/sys/dev/scsi/logging_level -2147483648 Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Cc: Mikulas Patocka <mikulas@twibright.com> Cc: Robert Xiao <nneonneo@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kexec: export KERNEL_IMAGE_SIZE to vmcoreinfoBaoquan He
In x86_64, since v2.6.26 the KERNEL_IMAGE_SIZE is changed to 512M, and accordingly the MODULES_VADDR is changed to 0xffffffffa0000000. However, in v3.12 Kees Cook introduced kaslr to randomise the location of kernel. And the kernel text mapping addr space is enlarged from 512M to 1G. That means now KERNEL_IMAGE_SIZE is variable, its value is 512M when kaslr support is not compiled in and 1G when kaslr support is compiled in. Accordingly the MODULES_VADDR is changed too to be: #define MODULES_VADDR (__START_KERNEL_map + KERNEL_IMAGE_SIZE) So when kaslr is compiled in and enabled, the kernel text mapping addr space and modules vaddr space need be adjusted. Otherwise makedumpfile will collapse since the addr for some symbols is not correct. Hence KERNEL_IMAGE_SIZE need be exported to vmcoreinfo and got in makedumpfile to help calculate MODULES_VADDR. Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kexec: align crash_notes allocation to make it be inside one physical pageBaoquan He
People reported that crash_notes in /proc/vmcore were corrupted and this cause crash kdump failure. With code debugging and log we got the root cause. This is because percpu variable crash_notes are allocated in 2 vmalloc pages. Currently percpu is based on vmalloc by default. Vmalloc can't guarantee 2 continuous vmalloc pages are also on 2 continuous physical pages. So when 1st kernel exports the starting address and size of crash_notes through sysfs like below: /sys/devices/system/cpu/cpux/crash_notes /sys/devices/system/cpu/cpux/crash_notes_size kdump kernel use them to get the content of crash_notes. However the 2nd part may not be in the next neighbouring physical page as we expected if crash_notes are allocated accross 2 vmalloc pages. That's why nhdr_ptr->n_namesz or nhdr_ptr->n_descsz could be very huge in update_note_header_size_elf64() and cause note header merging failure or some warnings. In this patch change to call __alloc_percpu() to passed in the align value by rounding crash_notes_size up to the nearest power of two. This makes sure the crash_notes is allocated inside one physical page since sizeof(note_buf_t) in all ARCHS is smaller than PAGE_SIZE. Meanwhile add a BUILD_BUG_ON to break compile if size is bigger than PAGE_SIZE since crash_notes definitely will be in 2 pages. That need be avoided, and need be reported if it's unavoidable. [akpm@linux-foundation.org: use correct comment layout] Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kexec: remove unnecessary test in kimage_alloc_crash_control_pages()Minfei Huang
Transforming PFN(Page Frame Number) to struct page is never failure, so we can simplify the code logic to do the image->control_page assignment directly in the loop, and remove the unnecessary conditional judgement. Signed-off-by: Minfei Huang <mnfhuang@gmail.com> Acked-by: Dave Young <dyoung@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Simon Horman <horms@verge.net.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kexec: split kexec_load syscall from kexec core codeDave Young
There are two kexec load syscalls, kexec_load another and kexec_file_load. kexec_file_load has been splited as kernel/kexec_file.c. In this patch I split kexec_load syscall code to kernel/kexec.c. And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and use kexec_file_load only, or vice verse. The original requirement is from Ted Ts'o, he want kexec kernel signature being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use kexec_load syscall can bypass the checking. Vivek Goyal proposed to create a common kconfig option so user can compile in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects KEXEC_CORE so that old config files still work. Because there's general code need CONFIG_KEXEC_CORE, so I updated all the architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects KEXEC_CORE in arch Kconfig. Also updated general kernel code with to kexec_load syscall. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Dave Young <dyoung@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Josh Boyer <jwboyer@fedoraproject.org> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kexec: split kexec_file syscall code to kexec_file.cDave Young
Split kexec_file syscall related code to another file kernel/kexec_file.c so that the #ifdef CONFIG_KEXEC_FILE in kexec.c can be dropped. Sharing variables and functions are moved to kernel/kexec_internal.h per suggestion from Vivek and Petr. [akpm@linux-foundation.org: fix bisectability] [akpm@linux-foundation.org: declare the various arch_kexec functions] [akpm@linux-foundation.org: fix build] Signed-off-by: Dave Young <dyoung@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Josh Boyer <jwboyer@fedoraproject.org> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kmod: handle UMH_WAIT_PROC from system unbound workqueueFrederic Weisbecker
The UMH_WAIT_PROC handler runs in its own thread in order to make sure that waiting for the exec kernel thread completion won't block other usermodehelper queued jobs. On older workqueue implementations, worklets couldn't sleep without blocking the rest of the queue. But now the workqueue subsystem handles that. Khelper still had the older limitation due to its singlethread properties but we replaced it to system unbound workqueues. Those are affine to the current node and can block up to some number of instances. They are a good candidate to handle UMH_WAIT_PROC assuming that we have enough system unbound workers to handle lots of parallel usermodehelper jobs. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kmod: use system_unbound_wq instead of khelperFrederic Weisbecker
We need to launch the usermodehelper kernel threads with the widest affinity and this is partly why we use khelper. This workqueue has unbound properties and thus a wide affinity inherited by all its children. Now khelper also has special properties that we aren't much interested in: ordered and singlethread. There is really no need about ordering as all we do is creating kernel threads. This can be done concurrently. And singlethread is a useless limitation as well. The workqueue engine already proposes generic unbound workqueues that don't share these useless properties and handle well parallel jobs. The only worrysome specific is their affinity to the node of the current CPU. It's fine for creating the usermodehelper kernel threads but those inherit this affinity for longer jobs such as requesting modules. This patch proposes to use these node affine unbound workqueues assuming that a node is sufficient to handle several parallel usermodehelper requests. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kmod: add up-to-date explanations on the purpose of each asynchronous levelsFrederic Weisbecker
There seem to be quite some confusions on the comments, likely due to changes that came after them. Now since it's very non obvious why we have 3 levels of asynchronous code to implement usermodehelpers, it's important to comment in detail the reason of this layout. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kmod: remove unecessary explicit wide CPU affinity settingFrederic Weisbecker
Khelper is affine to all CPUs. Now since it creates the call_usermodehelper_exec_[a]sync() kernel threads, those inherit the wide affinity. As such explicitly forcing a wide affinity from those kernel threads is like a no-op. Just remove it. It's needless and it breaks CPU isolation users who rely on workqueue affinity tuning. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kmod: bunch of internal functions renamesFrederic Weisbecker
This patchset does a bunch of cleanups and converts khelper to use system unbound workqueues. The 3 first patches should be uncontroversial. The last 2 patches are debatable. Kmod creates kernel threads that perform userspace jobs and we want those to have a large affinity in order not to contend busy CPUs. This is (partly) why we use khelper which has a wide affinity that the kernel threads it create can inherit from. Now khelper is a dedicated workqueue that has singlethread properties which we aren't interested in. Hence those two debatable changes: _ We would like to use generic workqueues. System unbound workqueues are a very good candidate but they are not wide affine, only node affine. Now probably a node is enough to perform many parallel kmod jobs. _ We would like to remove the wait_for_helper kernel thread (UMH_WAIT_PROC handler) to use the workqueue. It means that if the workqueue blocks, and no other worker can take pending kmod request, we can be screwed. Now if we have 512 threads, this should be enough. This patch (of 5): Underscores on function names aren't much verbose to explain the purpose of a function. And kmod has interesting such flavours. Lets rename the following functions: * __call_usermodehelper -> call_usermodehelper_exec_work * ____call_usermodehelper -> call_usermodehelper_exec_async * wait_for_helper -> call_usermodehelper_exec_sync Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>