1. 23 12月, 2015 19 次提交
  2. 20 12月, 2015 2 次提交
    • S
      rtc: da9063: fix access ordering error during RTC interrupt at system power on · 77535ace
      Steve Twiss 提交于
      This fix alters the ordering of the IRQ and device registrations in the RTC
      driver probe function. This change will apply to the RTC driver that supports
      both DA9063 and DA9062 PMICs.
      
      A problem could occur with the existing RTC driver if:
      
      A system is started from a cold boot using the PMIC RTC IRQ to initiate a
      power on operation. For instance, if an RTC alarm is used to start a
      platform from power off.
      The existing driver IRQ is requested before the device has been properly
      registered.
      i.e.
          ret = devm_request_threaded_irq()
      comes before
          rtc->rtc_dev = devm_rtc_device_register();
      
      In this case, the interrupt can be called before the device has been
      registered and the handler can be called immediately. The IRQ handler
      da9063_alarm_event() contains the function call
      
          rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
      
      which in turn tries to access the unavailable rtc->rtc_dev.
      
      The fix is to reorder the functions inside the RTC probe. The IRQ is
      requested after the RTC device resource has been registered so that
      get_irq_byname is the last thing to happen.
      Signed-off-by: NSteve Twiss <stwiss.opensource@diasemi.com>
      Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
      77535ace
    • J
      rtc: rk808: Compensate for Rockchip calendar deviation on November 31st · f076ef44
      Julius Werner 提交于
      In A.D. 1582 Pope Gregory XIII found that the existing Julian calendar
      insufficiently represented reality, and changed the rules about
      calculating leap years to account for this. Similarly, in A.D. 2013
      Rockchip hardware engineers found that the new Gregorian calendar still
      contained flaws, and that the month of November should be counted up to
      31 days instead. Unfortunately it takes a long time for calendar changes
      to gain widespread adoption, and just like more than 300 years went by
      before the last Protestant nation implemented Greg's proposal, we will
      have to wait a while until all religions and operating system kernels
      acknowledge the inherent advantages of the Rockchip system. Until then
      we need to translate dates read from (and written to) Rockchip hardware
      back to the Gregorian format.
      
      This patch works by defining Jan 1st, 2016 as the arbitrary anchor date
      on which Rockchip and Gregorian calendars are in sync. From that we can
      translate arbitrary later dates back and forth by counting the number
      of November/December transitons since the anchor date to determine the
      offset between the calendars. We choose this method (rather than trying
      to regularly "correct" the date stored in hardware) since it's the only
      way to ensure perfect time-keeping even if the system may be shut down
      for an unknown number of years. The drawback is that other software
      reading the same hardware (e.g. mainboard firmware) must use the same
      translation convention (including the same anchor date) to be able to
      read and write correct timestamps from/to the RTC.
      Signed-off-by: NJulius Werner <jwerner@chromium.org>
      Reviewed-by: NDouglas Anderson <dianders@chromium.org>
      Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
      f076ef44
  3. 19 12月, 2015 10 次提交
  4. 18 12月, 2015 9 次提交
    • K
      xen/pciback: Don't allow MSI-X ops if PCI_COMMAND_MEMORY is not set. · 408fb0e5
      Konrad Rzeszutek Wilk 提交于
      commit f598282f ("PCI: Fix the NIU MSI-X problem in a better way")
      teaches us that dealing with MSI-X can be troublesome.
      
      Further checks in the MSI-X architecture shows that if the
      PCI_COMMAND_MEMORY bit is turned of in the PCI_COMMAND we
      may not be able to access the BAR (since they are memory regions).
      
      Since the MSI-X tables are located in there.. that can lead
      to us causing PCIe errors. Inhibit us performing any
      operation on the MSI-X unless the MEMORY bit is set.
      
      Note that Xen hypervisor with:
      "x86/MSI-X: access MSI-X table only after having enabled MSI-X"
      will return:
      xen_pciback: 0000:0a:00.1: error -6 enabling MSI-X for guest 3!
      
      When the generic MSI code tries to setup the PIRQ without
      MEMORY bit set. Which means with later versions of Xen
      (4.6) this patch is not neccessary.
      
      This is part of XSA-157
      
      CC: stable@vger.kernel.org
      Reviewed-by: NJan Beulich <jbeulich@suse.com>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      408fb0e5
    • K
      xen/pciback: For XEN_PCI_OP_disable_msi[|x] only disable if device has MSI(X) enabled. · 7cfb905b
      Konrad Rzeszutek Wilk 提交于
      Otherwise just continue on, returning the same values as
      previously (return of 0, and op->result has the PIRQ value).
      
      This does not change the behavior of XEN_PCI_OP_disable_msi[|x].
      
      The pci_disable_msi or pci_disable_msix have the checks for
      msi_enabled or msix_enabled so they will error out immediately.
      
      However the guest can still call these operations and cause
      us to disable the 'ack_intr'. That means the backend IRQ handler
      for the legacy interrupt will not respond to interrupts anymore.
      
      This will lead to (if the device is causing an interrupt storm)
      for the Linux generic code to disable the interrupt line.
      
      Naturally this will only happen if the device in question
      is plugged in on the motherboard on shared level interrupt GSI.
      
      This is part of XSA-157
      
      CC: stable@vger.kernel.org
      Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      7cfb905b
    • K
      xen/pciback: Do not install an IRQ handler for MSI interrupts. · a396f3a2
      Konrad Rzeszutek Wilk 提交于
      Otherwise an guest can subvert the generic MSI code to trigger
      an BUG_ON condition during MSI interrupt freeing:
      
       for (i = 0; i < entry->nvec_used; i++)
              BUG_ON(irq_has_action(entry->irq + i));
      
      Xen PCI backed installs an IRQ handler (request_irq) for
      the dev->irq whenever the guest writes PCI_COMMAND_MEMORY
      (or PCI_COMMAND_IO) to the PCI_COMMAND register. This is
      done in case the device has legacy interrupts the GSI line
      is shared by the backend devices.
      
      To subvert the backend the guest needs to make the backend
      to change the dev->irq from the GSI to the MSI interrupt line,
      make the backend allocate an interrupt handler, and then command
      the backend to free the MSI interrupt and hit the BUG_ON.
      
      Since the backend only calls 'request_irq' when the guest
      writes to the PCI_COMMAND register the guest needs to call
      XEN_PCI_OP_enable_msi before any other operation. This will
      cause the generic MSI code to setup an MSI entry and
      populate dev->irq with the new PIRQ value.
      
      Then the guest can write to PCI_COMMAND PCI_COMMAND_MEMORY
      and cause the backend to setup an IRQ handler for dev->irq
      (which instead of the GSI value has the MSI pirq). See
      'xen_pcibk_control_isr'.
      
      Then the guest disables the MSI: XEN_PCI_OP_disable_msi
      which ends up triggering the BUG_ON condition in 'free_msi_irqs'
      as there is an IRQ handler for the entry->irq (dev->irq).
      
      Note that this cannot be done using MSI-X as the generic
      code does not over-write dev->irq with the MSI-X PIRQ values.
      
      The patch inhibits setting up the IRQ handler if MSI or
      MSI-X (for symmetry reasons) code had been called successfully.
      
      P.S.
      Xen PCIBack when it sets up the device for the guest consumption
      ends up writting 0 to the PCI_COMMAND (see xen_pcibk_reset_device).
      XSA-120 addendum patch removed that - however when upstreaming said
      addendum we found that it caused issues with qemu upstream. That
      has now been fixed in qemu upstream.
      
      This is part of XSA-157
      
      CC: stable@vger.kernel.org
      Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      a396f3a2
    • K
      xen/pciback: Return error on XEN_PCI_OP_enable_msix when device has MSI or MSI-X enabled · 5e0ce145
      Konrad Rzeszutek Wilk 提交于
      The guest sequence of:
      
        a) XEN_PCI_OP_enable_msix
        b) XEN_PCI_OP_enable_msix
      
      results in hitting an NULL pointer due to using freed pointers.
      
      The device passed in the guest MUST have MSI-X capability.
      
      The a) constructs and SysFS representation of MSI and MSI groups.
      The b) adds a second set of them but adding in to SysFS fails (duplicate entry).
      'populate_msi_sysfs' frees the newly allocated msi_irq_groups (note that
      in a) pdev->msi_irq_groups is still set) and also free's ALL of the
      MSI-X entries of the device (the ones allocated in step a) and b)).
      
      The unwind code: 'free_msi_irqs' deletes all the entries and tries to
      delete the pdev->msi_irq_groups (which hasn't been set to NULL).
      However the pointers in the SysFS are already freed and we hit an
      NULL pointer further on when 'strlen' is attempted on a freed pointer.
      
      The patch adds a simple check in the XEN_PCI_OP_enable_msix to guard
      against that. The check for msi_enabled is not stricly neccessary.
      
      This is part of XSA-157
      
      CC: stable@vger.kernel.org
      Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
      Reviewed-by: NJan Beulich <jbeulich@suse.com>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      5e0ce145
    • K
      xen/pciback: Return error on XEN_PCI_OP_enable_msi when device has MSI or MSI-X enabled · 56441f3c
      Konrad Rzeszutek Wilk 提交于
      The guest sequence of:
      
       a) XEN_PCI_OP_enable_msi
       b) XEN_PCI_OP_enable_msi
       c) XEN_PCI_OP_disable_msi
      
      results in hitting an BUG_ON condition in the msi.c code.
      
      The MSI code uses an dev->msi_list to which it adds MSI entries.
      Under the above conditions an BUG_ON() can be hit. The device
      passed in the guest MUST have MSI capability.
      
      The a) adds the entry to the dev->msi_list and sets msi_enabled.
      The b) adds a second entry but adding in to SysFS fails (duplicate entry)
      and deletes all of the entries from msi_list and returns (with msi_enabled
      is still set).  c) pci_disable_msi passes the msi_enabled checks and hits:
      
      BUG_ON(list_empty(dev_to_msi_list(&dev->dev)));
      
      and blows up.
      
      The patch adds a simple check in the XEN_PCI_OP_enable_msi to guard
      against that. The check for msix_enabled is not stricly neccessary.
      
      This is part of XSA-157.
      
      CC: stable@vger.kernel.org
      Reviewed-by: NDavid Vrabel <david.vrabel@citrix.com>
      Reviewed-by: NJan Beulich <jbeulich@suse.com>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      56441f3c
    • K
      xen/pciback: Save xen_pci_op commands before processing it · 8135cf8b
      Konrad Rzeszutek Wilk 提交于
      Double fetch vulnerabilities that happen when a variable is
      fetched twice from shared memory but a security check is only
      performed the first time.
      
      The xen_pcibk_do_op function performs a switch statements on the op->cmd
      value which is stored in shared memory. Interestingly this can result
      in a double fetch vulnerability depending on the performed compiler
      optimization.
      
      This patch fixes it by saving the xen_pci_op command before
      processing it. We also use 'barrier' to make sure that the
      compiler does not perform any optimization.
      
      This is part of XSA155.
      
      CC: stable@vger.kernel.org
      Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Signed-off-by: NJan Beulich <JBeulich@suse.com>
      Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      8135cf8b
    • D
      xen-scsiback: safely copy requests · be69746e
      David Vrabel 提交于
      The copy of the ring request was lacking a following barrier(),
      potentially allowing the compiler to optimize the copy away.
      
      Use RING_COPY_REQUEST() to ensure the request is copied to local
      memory.
      
      This is part of XSA155.
      
      CC: stable@vger.kernel.org
      Reviewed-by: NJuergen Gross <jgross@suse.com>
      Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      be69746e
    • R
      xen-blkback: read from indirect descriptors only once · 18779149
      Roger Pau Monné 提交于
      Since indirect descriptors are in memory shared with the frontend, the
      frontend could alter the first_sect and last_sect values after they have
      been validated but before they are recorded in the request.  This may
      result in I/O requests that overflow the foreign page, possibly
      overwriting local pages when the I/O request is executed.
      
      When parsing indirect descriptors, only read first_sect and last_sect
      once.
      
      This is part of XSA155.
      
      CC: stable@vger.kernel.org
      Signed-off-by: NRoger Pau Monné <roger.pau@citrix.com>
      Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      18779149
    • R
      xen-blkback: only read request operation from shared ring once · 1f13d75c
      Roger Pau Monné 提交于
      A compiler may load a switch statement value multiple times, which could
      be bad when the value is in memory shared with the frontend.
      
      When converting a non-native request to a native one, ensure that
      src->operation is only loaded once by using READ_ONCE().
      
      This is part of XSA155.
      
      CC: stable@vger.kernel.org
      Signed-off-by: NRoger Pau Monné <roger.pau@citrix.com>
      Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
      Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      1f13d75c