1. 29 10月, 2017 1 次提交
    • C
      genirq: Document vcpu_info usage for percpu_devid interrupts · 250a53d6
      Christoffer Dall 提交于
      It is currently unclear how to set the VCPU affinity for a percpu_devid
      interrupt , since the Linux irq_data structure describes the state for
      multiple interrupts, one for each physical CPU on the system.  Since
      each such interrupt can be associated with different VCPUs or none at
      all, associating a single VCPU state with such an interrupt does not
      capture the necessary semantics.
      
      The implementers of irq_set_affinity are the Intel and AMD IOMMUs, and
      the ARM GIC irqchip.  The Intel and AMD callers do not appear to use
      percpu_devid interrupts, and the ARM GIC implementation only checks the
      pointer against NULL vs. non-NULL.
      
      Therefore, simply update the function documentation to explain the
      expected use in the context of percpu_devid interrupts, allowing future
      changes or additions to irqchip implementers to do the right thing.
      Signed-off-by: NChristoffer Dall <cdall@linaro.org>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
      Cc: kvm@vger.kernel.org
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Eric Auger <eric.auger@redhat.com>
      Cc: kvmarm@lists.cs.columbia.edu
      Cc: linux-arm-kernel@lists.infradead.org
      Link: https://lkml.kernel.org/r/1509093281-15225-13-git-send-email-cdall@linaro.org
      250a53d6
  2. 19 10月, 2017 2 次提交
  3. 26 9月, 2017 12 次提交
    • T
      genirq/matrix: Add tracepoints · ec0f7cd2
      Thomas Gleixner 提交于
      Add tracepoints for the irq bitmap matrix allocator.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213153.279468022@linutronix.de
      ec0f7cd2
    • T
      genirq: Implement bitmap matrix allocator · 2f75d9e1
      Thomas Gleixner 提交于
      Implement the infrastructure for a simple bitmap based allocator, which
      will replace the x86 vector allocator. It's in the core code as other
      architectures might be able to reuse/extend it. For now it only implements
      allocations for single CPUs, but it's simple to add multi CPU allocation
      support if required.
      
      The concept is rather simple:
      
       Global information:
       	system_vector bitmap
      	global accounting
      
       PerCPU information:
       	allocation bitmap
      	managed allocation bitmap
      	local accounting
      
      The system vector bitmap is used to exclude vectors system wide from the
      allocation space.
      
      The allocation bitmap is used to keep track of per cpu used vectors.
      
      The managed allocation bitmap is used to reserve vectors for managed
      interrupts.
      
      When a regular (non managed) interrupt allocation happens then the
      following rule applies:
      
            tmpmap = system_map | alloc_map | managed_map
            find_zero_bit(tmpmap)
      
      Oring the bitmaps together gives the real available space. The same rule
      applies for reserving a managed interrupt vector. But contrary to the
      regular interrupts the reservation only marks the bit in the managed map
      and therefor excludes it from the regular allocations. The managed map is
      only cleaned out when the a managed interrupt is completely released and it
      stays alive accross CPU offline/online operations.
      
      For managed interrupt allocations the rule is:
      
            tmpmap = managed_map & ~alloc_map
            find_first_bit(tmpmap)
      
      This returns the first bit which is in the managed map, but not yet
      allocated in the allocation map. The allocation marks it in the allocation
      map and hands it back to the caller for use.
      
      The rest of the code are helper functions to handle the various
      requirements and the accounting which are necessary to replace the x86
      vector allocation code. The result is a single patch as the evolution of
      this infrastructure cannot be represented in bits and pieces.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213153.185437174@linutronix.de
      2f75d9e1
    • T
      genirq/irqdomain: Add force reactivation flag to irq domains · 22d0b12f
      Thomas Gleixner 提交于
      Allow irqdomains to tell the core code, that after early activation the
      interrupt needs to be reactivated at request_irq() time.
      
      This allows reservation of vectors at early activation time and actual
      vector assignment at request_irq() time.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213153.106242536@linutronix.de
      22d0b12f
    • T
      genirq/irqdomain: Propagate early activation · 42e1cc2d
      Thomas Gleixner 提交于
      Propagate the early activation mode to the irqdomain activate()
      callbacks. This is required for the upcoming reservation, late vector
      assignment scheme, so that the early activation call can act accordingly.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213153.028353660@linutronix.de
      42e1cc2d
    • T
      genirq/irqdomain: Allow irq_domain_activate_irq() to fail · bb9b428a
      Thomas Gleixner 提交于
      Allow irq_domain_activate_irq() to fail. This is required to support a
      reservation and late vector assignment scheme.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213152.933882227@linutronix.de
      bb9b428a
    • T
      genirq/irqdomain: Update irq_domain_ops.activate() signature · 72491643
      Thomas Gleixner 提交于
      The irq_domain_ops.activate() callback has no return value and no way to
      tell the function that the activation is early.
      
      The upcoming changes to support a reservation scheme which allows to assign
      interrupt vectors on x86 only when the interrupt is actually requested
      requires:
      
        - A return value, so activation can fail at request_irq() time
        
        - Information that the activate invocation is early, i.e. before
          request_irq().
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213152.848490816@linutronix.de
      72491643
    • T
      genirq: Separate activation and startup · c942cee4
      Thomas Gleixner 提交于
      Activation of an interrupt and startup are currently a combo
      functionlity. That works so far, but upcoming changes require a strict
      separation because the activation can fail in future.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213152.754334077@linutronix.de
      c942cee4
    • T
      genirq: Set managed shut down flag at init · 239306fe
      Thomas Gleixner 提交于
      Managed interrupts should start up in managed shutdown mode. Set the status
      flag when initialising the irq descriptor.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213152.669687742@linutronix.de
      239306fe
    • T
      genirq: Make state consistent for !IRQ_DOMAIN_HIERARCHY · 457f6d35
      Thomas Gleixner 提交于
      In the !IRQ_DOMAIN_HIERARCHY cas the activation stubs are not
      setting/clearing the activation status bits. This is not a problem at the
      moment, but upcoming changes require a correct status.
      
      Add the set/clear incovations to the stub functions and move them to the
      core internal header to avoid duplication and visibility outside the core.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213152.591985591@linutronix.de
      457f6d35
    • T
      irqdomain/debugfs: Provide domain specific debug callback · c3e7239a
      Thomas Gleixner 提交于
      Some interrupt domains like the X86 vector domain has special requirements
      for debugging, like showing the vector usage on the CPUs.
      
      Add a callback to the irqdomain ops which can be filled in by domains which
      require it and add conditional invocations to the irqdomain and the per irq
      debug files.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213152.512937505@linutronix.de
      c3e7239a
    • T
      genirq/msi: Capture device name for debugfs · 07557ccb
      Thomas Gleixner 提交于
      For debugging the allocation of unused or potentially leaked interrupt
      descriptor it's helpful to have some information about the site which
      allocated them. In case of MSI this is simple because the caller hands the
      device struct pointer into the domain allocation function.
      
      Duplicate the device name and show it in the debugfs entry of the interrupt
      descriptor.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213152.433038426@linutronix.de
      07557ccb
    • T
      genirq/debugfs: Show debug information for all irq descriptors · e0b47794
      Thomas Gleixner 提交于
      Currently the debugfs shows only information about actively used interrupts
      like /proc/irq/ does. That's fine for most cases, but not helpful when
      internals of allocated, but unused interrupt descriptors have to
      debugged. It's also useful to provide information about all descriptors so
      leaks can be debugged in a simpler way.
      
      Move the debugfs registration to the descriptor allocation code.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NJuergen Gross <jgross@suse.com>
      Tested-by: NYu Chen <yu.c.chen@intel.com>
      Acked-by: NJuergen Gross <jgross@suse.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: https://lkml.kernel.org/r/20170913213152.355525908@linutronix.de
      e0b47794
  4. 25 9月, 2017 1 次提交
  5. 21 9月, 2017 1 次提交
    • Y
      bpf: one perf event close won't free bpf program attached by another perf event · ec9dd352
      Yonghong Song 提交于
      This patch fixes a bug exhibited by the following scenario:
        1. fd1 = perf_event_open with attr.config = ID1
        2. attach bpf program prog1 to fd1
        3. fd2 = perf_event_open with attr.config = ID1
           <this will be successful>
        4. user program closes fd2 and prog1 is detached from the tracepoint.
        5. user program with fd1 does not work properly as tracepoint
           no output any more.
      
      The issue happens at step 4. Multiple perf_event_open can be called
      successfully, but only one bpf prog pointer in the tp_event. In the
      current logic, any fd release for the same tp_event will free
      the tp_event->prog.
      
      The fix is to free tp_event->prog only when the closing fd
      corresponds to the one which registered the program.
      Signed-off-by: NYonghong Song <yhs@fb.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ec9dd352
  6. 20 9月, 2017 5 次提交
    • D
      bpf: fix ri->map_owner pointer on bpf_prog_realloc · 7c300131
      Daniel Borkmann 提交于
      Commit 109980b8 ("bpf: don't select potentially stale
      ri->map from buggy xdp progs") passed the pointer to the prog
      itself to be loaded into r4 prior on bpf_redirect_map() helper
      call, so that we can store the owner into ri->map_owner out of
      the helper.
      
      Issue with that is that the actual address of the prog is still
      subject to change when subsequent rewrites occur that require
      slow path in bpf_prog_realloc() to alloc more memory, e.g. from
      patching inlining helper functions or constant blinding. Thus,
      we really need to take prog->aux as the address we're holding,
      which also works with prog clones as they share the same aux
      object.
      
      Instead of then fetching aux->prog during runtime, which could
      potentially incur cache misses due to false sharing, we are
      going to just use aux for comparison on the map owner. This
      will also keep the patchlet of the same size, and later check
      in xdp_map_invalid() only accesses read-only aux pointer from
      the prog, it's also in the same cacheline already from prior
      access when calling bpf_func.
      
      Fixes: 109980b8 ("bpf: don't select potentially stale ri->map from buggy xdp progs")
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7c300131
    • E
      bpf: do not disable/enable BH in bpf_map_free_id() · 930651a7
      Eric Dumazet 提交于
      syzkaller reported following splat [1]
      
      Since hard irq are disabled by the caller, bpf_map_free_id()
      should not try to enable/disable BH.
      
      Another solution would be to change htab_map_delete_elem() to
      defer the free_htab_elem() call after
      raw_spin_unlock_irqrestore(&b->lock, flags), but this might be not
      enough to cover other code paths.
      
      [1]
      WARNING: CPU: 1 PID: 8052 at kernel/softirq.c:161 __local_bh_enable_ip
      +0x1e/0x160 kernel/softirq.c:161
      Kernel panic - not syncing: panic_on_warn set ...
      
      CPU: 1 PID: 8052 Comm: syz-executor1 Not tainted 4.13.0-next-20170915+
      #23
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
      Google 01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:16 [inline]
       dump_stack+0x194/0x257 lib/dump_stack.c:52
       panic+0x1e4/0x417 kernel/panic.c:181
       __warn+0x1c4/0x1d9 kernel/panic.c:542
       report_bug+0x211/0x2d0 lib/bug.c:183
       fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178
       do_trap_no_signal arch/x86/kernel/traps.c:212 [inline]
       do_trap+0x260/0x390 arch/x86/kernel/traps.c:261
       do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298
       do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311
       invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
      RIP: 0010:__local_bh_enable_ip+0x1e/0x160 kernel/softirq.c:161
      RSP: 0018:ffff8801cdcd7748 EFLAGS: 00010046
      RAX: 0000000000000082 RBX: 0000000000000201 RCX: 0000000000000000
      RDX: 1ffffffff0b5933c RSI: 0000000000000201 RDI: ffffffff85ac99e0
      RBP: ffff8801cdcd7758 R08: ffffffff85b87158 R09: 1ffff10039b9aec6
      R10: ffff8801c99f24c0 R11: 0000000000000002 R12: ffffffff817b0b47
      R13: dffffc0000000000 R14: ffff8801cdcd77e8 R15: 0000000000000001
       __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline]
       _raw_spin_unlock_bh+0x30/0x40 kernel/locking/spinlock.c:207
       spin_unlock_bh include/linux/spinlock.h:361 [inline]
       bpf_map_free_id kernel/bpf/syscall.c:197 [inline]
       __bpf_map_put+0x267/0x320 kernel/bpf/syscall.c:227
       bpf_map_put+0x1a/0x20 kernel/bpf/syscall.c:235
       bpf_map_fd_put_ptr+0x15/0x20 kernel/bpf/map_in_map.c:96
       free_htab_elem+0xc3/0x1b0 kernel/bpf/hashtab.c:658
       htab_map_delete_elem+0x74d/0x970 kernel/bpf/hashtab.c:1063
       map_delete_elem kernel/bpf/syscall.c:633 [inline]
       SYSC_bpf kernel/bpf/syscall.c:1479 [inline]
       SyS_bpf+0x2188/0x46a0 kernel/bpf/syscall.c:1451
       entry_SYSCALL_64_fastpath+0x1f/0xbe
      
      Fixes: f3f1c054 ("bpf: Introduce bpf_map ID")
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Cc: Martin KaFai Lau <kafai@fb.com>
      Acked-by: NMartin KaFai Lau <kafai@fb.com>
      Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      930651a7
    • T
      tracing: Fix trace_pipe behavior for instance traces · 75df6e68
      Tahsin Erdogan 提交于
      When reading data from trace_pipe, tracing_wait_pipe() performs a
      check to see if tracing has been turned off after some data was read.
      Currently, this check always looks at global trace state, but it
      should be checking the trace instance where trace_pipe is located at.
      
      Because of this bug, cat instances/i1/trace_pipe in the following
      script will immediately exit instead of waiting for data:
      
      cd /sys/kernel/debug/tracing
      echo 0 > tracing_on
      mkdir -p instances/i1
      echo 1 > instances/i1/tracing_on
      echo 1 > instances/i1/events/sched/sched_process_exec/enable
      cat instances/i1/trace_pipe
      
      Link: http://lkml.kernel.org/r/20170917102348.1615-1-tahsin@google.com
      
      Cc: stable@vger.kernel.org
      Fixes: 10246fa3 ("tracing: give easy way to clear trace buffer")
      Signed-off-by: NTahsin Erdogan <tahsin@google.com>
      Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      75df6e68
    • Z
      tracing: Ignore mmiotrace from kernel commandline · c7b3ae0b
      Ziqian SUN (Zamir) 提交于
      The mmiotrace tracer cannot be enabled with ftrace=mmiotrace in kernel
      commandline. With this patch, noboot is added to the tracer struct,
      and when system boot with a tracer that has noboot=true, it will print
      out a warning message and continue booting.
      
      Link: http://lkml.kernel.org/r/1505111195-31942-1-git-send-email-zsun@redhat.comSigned-off-by: NZiqian SUN (Zamir) <zsun@redhat.com>
      Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      c7b3ae0b
    • B
      tracing: Erase irqsoff trace with empty write · 8dd33bcb
      Bo Yan 提交于
      One convenient way to erase trace is "echo > trace". However, this
      is currently broken if the current tracer is irqsoff tracer. This
      is because irqsoff tracer use max_buffer as the default trace
      buffer.
      
      Set the max_buffer as the one to be cleared when it's the trace
      buffer currently in use.
      
      Link: http://lkml.kernel.org/r/1505754215-29411-1-git-send-email-byan@nvidia.com
      
      Cc: <mingo@redhat.com>
      Cc: stable@vger.kernel.org
      Fixes: 4acd4d00 ("tracing: give easy way to clear trace buffer")
      Signed-off-by: NBo Yan <byan@nvidia.com>
      Signed-off-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
      8dd33bcb
  7. 19 9月, 2017 1 次提交
  8. 17 9月, 2017 1 次提交
    • T
      genirq: Fix cpumask check in __irq_startup_managed() · 9cb067ef
      Thomas Gleixner 提交于
      The result of cpumask_any_and() is invalid when result greater or equal
      nr_cpu_ids. The current check is checking for greater only. Fix it.
      
      Fixes: 761ea388 ("genirq: Handle managed irqs gracefully in irq_startup()")
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Chen Yu <yu.c.chen@intel.com>
      Cc: Marc Zyngier <marc.zyngier@arm.com>
      Cc: Alok Kataria <akataria@vmware.com>
      Cc: Joerg Roedel <joro@8bytes.org>
      Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: stable@vger.kernel.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Rui Zhang <rui.zhang@intel.com>
      Cc: "K. Y. Srinivasan" <kys@microsoft.com>
      Cc: Arjan van de Ven <arjan@linux.intel.com>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Len Brown <lenb@kernel.org>
      Link: http://lkml.kernel.org/r/20170913213152.272283444@linutronix.de
      9cb067ef
  9. 16 9月, 2017 1 次提交
  10. 15 9月, 2017 2 次提交
    • T
      sched/wait: Introduce wakeup boomark in wake_up_page_bit · 11a19c7b
      Tim Chen 提交于
      Now that we have added breaks in the wait queue scan and allow bookmark
      on scan position, we put this logic in the wake_up_page_bit function.
      
      We can have very long page wait list in large system where multiple
      pages share the same wait list. We break the wake up walk here to allow
      other cpus a chance to access the list, and not to disable the interrupts
      when traversing the list for too long.  This reduces the interrupt and
      rescheduling latency, and excessive page wait queue lock hold time.
      
      [ v2: Remove bookmark_wake_function ]
      Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      11a19c7b
    • T
      sched/wait: Break up long wake list walk · 2554db91
      Tim Chen 提交于
      We encountered workloads that have very long wake up list on large
      systems. A waker takes a long time to traverse the entire wake list and
      execute all the wake functions.
      
      We saw page wait list that are up to 3700+ entries long in tests of
      large 4 and 8 socket systems. It took 0.8 sec to traverse such list
      during wake up. Any other CPU that contends for the list spin lock will
      spin for a long time. It is a result of the numa balancing migration of
      hot pages that are shared by many threads.
      
      Multiple CPUs waking are queued up behind the lock, and the last one
      queued has to wait until all CPUs did all the wakeups.
      
      The page wait list is traversed with interrupt disabled, which caused
      various problems. This was the original cause that triggered the NMI
      watch dog timer in: https://patchwork.kernel.org/patch/9800303/ . Only
      extending the NMI watch dog timer there helped.
      
      This patch bookmarks the waker's scan position in wake list and break
      the wake up walk, to allow access to the list before the waker resume
      its walk down the rest of the wait list. It lowers the interrupt and
      rescheduling latency.
      
      This patch also provides a performance boost when combined with the next
      patch to break up page wakeup list walk. We saw 22% improvement in the
      will-it-scale file pread2 test on a Xeon Phi system running 256 threads.
      
      [ v2: Merged in Linus' changes to remove the bookmark_wake_function, and
        simply access to flags. ]
      Reported-by: NKan Liang <kan.liang@intel.com>
      Tested-by: NKan Liang <kan.liang@intel.com>
      Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2554db91
  11. 14 9月, 2017 1 次提交
    • M
      mm: treewide: remove GFP_TEMPORARY allocation flag · 0ee931c4
      Michal Hocko 提交于
      GFP_TEMPORARY was introduced by commit e12ba74d ("Group short-lived
      and reclaimable kernel allocations") along with __GFP_RECLAIMABLE.  It's
      primary motivation was to allow users to tell that an allocation is
      short lived and so the allocator can try to place such allocations close
      together and prevent long term fragmentation.  As much as this sounds
      like a reasonable semantic it becomes much less clear when to use the
      highlevel GFP_TEMPORARY allocation flag.  How long is temporary? Can the
      context holding that memory sleep? Can it take locks? It seems there is
      no good answer for those questions.
      
      The current implementation of GFP_TEMPORARY is basically GFP_KERNEL |
      __GFP_RECLAIMABLE which in itself is tricky because basically none of
      the existing caller provide a way to reclaim the allocated memory.  So
      this is rather misleading and hard to evaluate for any benefits.
      
      I have checked some random users and none of them has added the flag
      with a specific justification.  I suspect most of them just copied from
      other existing users and others just thought it might be a good idea to
      use without any measuring.  This suggests that GFP_TEMPORARY just
      motivates for cargo cult usage without any reasoning.
      
      I believe that our gfp flags are quite complex already and especially
      those with highlevel semantic should be clearly defined to prevent from
      confusion and abuse.  Therefore I propose dropping GFP_TEMPORARY and
      replace all existing users to simply use GFP_KERNEL.  Please note that
      SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and
      so they will be placed properly for memory fragmentation prevention.
      
      I can see reasons we might want some gfp flag to reflect shorterm
      allocations but I propose starting from a clear semantic definition and
      only then add users with proper justification.
      
      This was been brought up before LSF this year by Matthew [1] and it
      turned out that GFP_TEMPORARY really doesn't have a clear semantic.  It
      seems to be a heuristic without any measured advantage for most (if not
      all) its current users.  The follow up discussion has revealed that
      opinions on what might be temporary allocation differ a lot between
      developers.  So rather than trying to tweak existing users into a
      semantic which they haven't expected I propose to simply remove the flag
      and start from scratch if we really need a semantic for short term
      allocations.
      
      [1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org
      
      [akpm@linux-foundation.org: fix typo]
      [akpm@linux-foundation.org: coding-style fixes]
      [sfr@canb.auug.org.au: drm/i915: fix up]
        Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au
      Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
      Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
      Acked-by: NMel Gorman <mgorman@suse.de>
      Acked-by: NVlastimil Babka <vbabka@suse.cz>
      Cc: Matthew Wilcox <willy@infradead.org>
      Cc: Neil Brown <neilb@suse.de>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0ee931c4
  12. 12 9月, 2017 5 次提交
  13. 11 9月, 2017 1 次提交
  14. 09 9月, 2017 6 次提交
    • J
      bpf: devmap, use cond_resched instead of cpu_relax · 374fb014
      John Fastabend 提交于
      Be a bit more friendly about waiting for flush bits to complete.
      Replace the cpu_relax() with a cond_resched().
      Suggested-by: NDaniel Borkmann <daniel@iogearbox.net>
      Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      374fb014
    • J
      bpf: add support for sockmap detach programs · 5a67da2a
      John Fastabend 提交于
      The bpf map sockmap supports adding programs via attach commands. This
      patch adds the detach command to keep the API symmetric and allow
      users to remove previously added programs. Otherwise the user would
      have to delete the map and re-add it to get in this state.
      
      This also adds a series of additional tests to capture detach operation
      and also attaching/detaching invalid prog types.
      
      API note: socks will run (or not run) programs depending on the state
      of the map at the time the sock is added. We do not for example walk
      the map and remove programs from previously attached socks.
      Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5a67da2a
    • D
      bpf: don't select potentially stale ri->map from buggy xdp progs · 109980b8
      Daniel Borkmann 提交于
      We can potentially run into a couple of issues with the XDP
      bpf_redirect_map() helper. The ri->map in the per CPU storage
      can become stale in several ways, mostly due to misuse, where
      we can then trigger a use after free on the map:
      
      i) prog A is calling bpf_redirect_map(), returning XDP_REDIRECT
      and running on a driver not supporting XDP_REDIRECT yet. The
      ri->map on that CPU becomes stale when the XDP program is unloaded
      on the driver, and a prog B loaded on a different driver which
      supports XDP_REDIRECT return code. prog B would have to omit
      calling to bpf_redirect_map() and just return XDP_REDIRECT, which
      would then access the freed map in xdp_do_redirect() since not
      cleared for that CPU.
      
      ii) prog A is calling bpf_redirect_map(), returning a code other
      than XDP_REDIRECT. prog A is then detached, which triggers release
      of the map. prog B is attached which, similarly as in i), would
      just return XDP_REDIRECT without having called bpf_redirect_map()
      and thus be accessing the freed map in xdp_do_redirect() since
      not cleared for that CPU.
      
      iii) prog A is attached to generic XDP, calling the bpf_redirect_map()
      helper and returning XDP_REDIRECT. xdp_do_generic_redirect() is
      currently not handling ri->map (will be fixed by Jesper), so it's
      not being reset. Later loading a e.g. native prog B which would,
      say, call bpf_xdp_redirect() and then returns XDP_REDIRECT would
      find in xdp_do_redirect() that a map was set and uses that causing
      use after free on map access.
      
      Fix thus needs to avoid accessing stale ri->map pointers, naive
      way would be to call a BPF function from drivers that just resets
      it to NULL for all XDP return codes but XDP_REDIRECT and including
      XDP_REDIRECT for drivers not supporting it yet (and let ri->map
      being handled in xdp_do_generic_redirect()). There is a less
      intrusive way w/o letting drivers call a reset for each BPF run.
      
      The verifier knows we're calling into bpf_xdp_redirect_map()
      helper, so it can do a small insn rewrite transparent to the prog
      itself in the sense that it fills R4 with a pointer to the own
      bpf_prog. We have that pointer at verification time anyway and
      R4 is allowed to be used as per calling convention we scratch
      R0 to R5 anyway, so they become inaccessible and program cannot
      read them prior to a write. Then, the helper would store the prog
      pointer in the current CPUs struct redirect_info. Later in
      xdp_do_*_redirect() we check whether the redirect_info's prog
      pointer is the same as passed xdp_prog pointer, and if that's
      the case then all good, since the prog holds a ref on the map
      anyway, so it is always valid at that point in time and must
      have a reference count of at least 1. If in the unlikely case
      they are not equal, it means we got a stale pointer, so we clear
      and bail out right there. Also do reset map and the owning prog
      in bpf_xdp_redirect(), so that bpf_xdp_redirect_map() and
      bpf_xdp_redirect() won't get mixed up, only the last call should
      take precedence. A tc bpf_redirect() doesn't use map anywhere
      yet, so no need to clear it there since never accessed in that
      layer.
      
      Note that in case the prog is released, and thus the map as
      well we're still under RCU read critical section at that time
      and have preemption disabled as well. Once we commit with the
      __dev_map_insert_ctx() from xdp_do_redirect_map() and set the
      map to ri->map_to_flush, we still wait for a xdp_do_flush_map()
      to finish in devmap dismantle time once flush_needed bit is set,
      so that is fine.
      
      Fixes: 97f91a7c ("bpf: add bpf_redirect_map helper routine")
      Reported-by: NJesper Dangaard Brouer <brouer@redhat.com>
      Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
      Signed-off-by: NJohn Fastabend <john.fastabend@gmail.com>
      Acked-by: NAlexei Starovoitov <ast@kernel.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      109980b8
    • D
      kcov: support compat processes · 7483e5d4
      Dmitry Vyukov 提交于
      Support compat processes in KCOV by providing compat_ioctl callback.
      Compat mode uses the same ioctl callback: we have 2 commands that do not
      use the argument and 1 that already checks that the arg does not overflow
      INT_MAX.  This allows to use KCOV-guided fuzzing in compat processes.
      
      Link: http://lkml.kernel.org/r/20170823100553.55812-1-dvyukov@google.comSigned-off-by: NDmitry Vyukov <dvyukov@google.com>
      Cc: <syzkaller@googlegroups.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7483e5d4
    • R
      drivers/pps: aesthetic tweaks to PPS-related content · a2d81803
      Robert P. J. Day 提交于
      Collection of aesthetic adjustments to various PPS-related files,
      directories and Documentation, some quite minor just for the sake of
      consistency, including:
      
       * Updated example of pps device tree node (courtesy Rodolfo G.)
       * "PPS-API" -> "PPS API"
       * "pps_source_info_s" -> "pps_source_info"
       * "ktimer driver" -> "pps-ktimer driver"
       * "ppstest /dev/pps0" -> "ppstest /dev/pps1" to match example
       * Add missing PPS-related entries to MAINTAINERS file
       * Other trivialities
      
      Link: http://lkml.kernel.org/r/alpine.LFD.2.20.1708261048220.8106@localhost.localdomainSigned-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
      Acked-by: NRodolfo Giometti <giometti@enneenne.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a2d81803
    • L
      kmod: move #ifdef CONFIG_MODULES wrapper to Makefile · 0ce2c202
      Luis R. Rodriguez 提交于
      The entire file is now conditionally compiled only when CONFIG_MODULES is
      enabled, and this this is a bool.  Just move this conditional to the
      Makefile as its easier to read this way.
      
      Link: http://lkml.kernel.org/r/20170810180618.22457-5-mcgrof@kernel.orgSigned-off-by: NLuis R. Rodriguez <mcgrof@kernel.org>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
      Cc: Jessica Yu <jeyu@redhat.com>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Michal Marek <mmarek@suse.com>
      Cc: Petr Mladek <pmladek@suse.com>
      Cc: Miroslav Benes <mbenes@suse.cz>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Guenter Roeck <linux@roeck-us.net>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Matt Redfearn <matt.redfearn@imgtec.com>
      Cc: Dan Carpenter <dan.carpenter@oracle.com>
      Cc: Colin Ian King <colin.king@canonical.com>
      Cc: Daniel Mentz <danielmentz@google.com>
      Cc: David Binderman <dcb314@hotmail.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0ce2c202