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  1. Nov 02, 2013
  2. Oct 28, 2013
  3. Oct 04, 2013
  4. Sep 30, 2013
    • Bart Kuivenhoven's avatar
      x86 efi: bugfix interrupt disabling sequence · 0ce6cda2
      Bart Kuivenhoven authored
      
      The problem in efi_main was that the idt was cleared before the
      interrupts were disabled.
      
      The UEFI spec states that interrupts aren't used so this shouldn't be
      too much of a problem. Peripherals however don't necessarily know about
      this and thus might cause interrupts to happen anyway. Even if
      ExitBootServices() has been called.
      
      This means there is a risk of an interrupt being triggered while the IDT
      register is nullified and the interrupt bit hasn't been cleared,
      allowing for a triple fault.
      
      This patch disables the interrupt flag, while leaving the existing IDT
      in place. The CPU won't care about the IDT at all as long as the
      interrupt bit is off, so it's safe to leave it in place as nothing will
      ever happen to it.
      
      [ Removed the now unused 'idt' variable - Matt ]
      
      Signed-off-by: default avatarBart Kuivenhoven <bemk@redhat.com>
      Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
      0ce6cda2
    • Linn Crosetto's avatar
      x86: EFI stub support for large memory maps · d2078d5a
      Linn Crosetto authored
      
      This patch fixes a problem with EFI memory maps larger than 128 entries
      when booting using the EFI stub, which results in overflowing e820_map
      in boot_params and an eventual halt when checking the map size in
      sanitize_e820_map().
      
      If the number of map entries is greater than what can fit in e820_map,
      add the extra entries to the setup_data list using type SETUP_E820_EXT.
      These extra entries are then picked up when the setup_data list is
      parsed in parse_e820_ext().
      
      Signed-off-by: default avatarLinn Crosetto <linn@hp.com>
      Signed-off-by: default avatarMatt Fleming <matt.fleming@intel.com>
      d2078d5a
  5. Sep 25, 2013
  6. Sep 05, 2013
  7. Aug 29, 2013
  8. Aug 27, 2013
    • Paul Mackerras's avatar
      powerpc: Work around gcc miscompilation of __pa() on 64-bit · bdbc29c1
      Paul Mackerras authored
      
      On 64-bit, __pa(&static_var) gets miscompiled by recent versions of
      gcc as something like:
      
              addis 3,2,.LANCHOR1+4611686018427387904@toc@ha
              addi 3,3,.LANCHOR1+4611686018427387904@toc@l
      
      This ends up effectively ignoring the offset, since its bottom 32 bits
      are zero, and means that the result of __pa() still has 0xC in the top
      nibble.  This happens with gcc 4.8.1, at least.
      
      To work around this, for 64-bit we make __pa() use an AND operator,
      and for symmetry, we make __va() use an OR operator.  Using an AND
      operator rather than a subtraction ends up with slightly shorter code
      since it can be done with a single clrldi instruction, whereas it
      takes three instructions to form the constant (-PAGE_OFFSET) and add
      it on.  (Note that MEMORY_START is always 0 on 64-bit.)
      
      CC: <stable@vger.kernel.org>
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      bdbc29c1
    • Benjamin Herrenschmidt's avatar
      powerpc: Don't Oops when accessing /proc/powerpc/lparcfg without hypervisor · f5f6cbb6
      Benjamin Herrenschmidt authored
      
      /proc/powerpc/lparcfg is an ancient facility (though still actively used)
      which allows access to some informations relative to the partition when
      running underneath a PAPR compliant hypervisor.
      
      It makes no sense on non-pseries machines. However, currently, not only
      can it be created on these if the kernel has pseries support, but accessing
      it on such a machine will crash due to trying to do hypervisor calls.
      
      In fact, it should also not do HV calls on older pseries that didn't have
      an hypervisor either.
      
      Finally, it has the plumbing to be a module but is a "bool" Kconfig option.
      
      This fixes the whole lot by turning it into a machine_device_initcall
      that is only created on pseries, and adding the necessary hypervisor
      check before calling the H_GET_EM_PARMS hypercall
      
      CC: <stable@vger.kernel.org>
      Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
      f5f6cbb6
  9. Aug 24, 2013
  10. Aug 22, 2013
    • Radu Caragea's avatar
      x86 get_unmapped_area: Access mmap_legacy_base through mm_struct member · 41aacc1e
      Radu Caragea authored
      
      This is the updated version of df54d6fa ("x86 get_unmapped_area():
      use proper mmap base for bottom-up direction") that only randomizes the
      mmap base address once.
      
      Signed-off-by: default avatarRadu Caragea <sinaelgl@gmail.com>
      Reported-and-tested-by: default avatarJeff Shorey <shoreyjeff@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Michel Lespinasse <walken@google.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Adrian Sendroiu <molecula2788@gmail.com>
      Cc: Greg KH <greg@kroah.com>
      Cc: Kamal Mostafa <kamal@canonical.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      41aacc1e
    • Linus Torvalds's avatar
      Revert "x86 get_unmapped_area(): use proper mmap base for bottom-up direction" · 5ea80f76
      Linus Torvalds authored
      This reverts commit df54d6fa.
      
      The commit isn't necessarily wrong, but because it recalculates the
      random mmap_base every time, it seems to confuse user memory allocators
      that expect contiguous mmap allocations even when the mmap address isn't
      specified.
      
      In particular, the MATLAB Java runtime seems to be unhappy. See
      
        https://bugzilla.kernel.org/show_bug.cgi?id=60774
      
      
      
      So we'll want to apply the random offset only once, and Radu has a patch
      for that.  Revert this older commit in order to apply the other one.
      
      Reported-by: default avatarJeff Shorey <shoreyjeff@gmail.com>
      Cc: Radu Caragea <sinaelgl@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      5ea80f76
    • Stephen Warren's avatar
      ARM: tegra: always enable USB VBUS regulators · 30ca2226
      Stephen Warren authored
      
      This fixes a regression exposed during the merge window by commit
      9f310ded "ARM: tegra: fix VBUS regulator GPIO polarity in DT"; namely that
      USB VBUS doesn't get turned on, so USB devices are not detected. This
      affects the internal USB port on TrimSlice (i.e. the USB->SATA bridge, to
      which the SSD is connected) and the external port(s) on Seaboard/
      Springbank and Whistler.
      
      The Tegra DT as written in v3.11 allows two paths to enable USB VBUS:
      
      1) Via the legacy DT binding for the USB controller; it can directly
         acquire a VBUS GPIO and activate it.
      
      2) Via a regulator for VBUS, which is referenced by the new DT binding
         for the USB controller.
      
      Those two methods both use the same GPIO, and hence whichever of the
      USB controller and regulator gets probed first ends up owning the GPIO.
      In practice, the USB driver only supports path (1) above, since the
      patches to support the new USB binding are not present until v3.12:-(
      
      In practice, the regulator ends up being probed first and owning the
      GPIO. Since nothing enables the regulator (the USB driver code is not
      yet present), the regulator ends up being turned off. This originally
      caused no problem, because the polarity in the regulator definition was
      incorrect, so attempting to turn off the regulator actually turned it
      on, and everything worked:-(
      
      However, when testing the new USB driver code in v3.12, I noticed the
      incorrect polarity and fixed it in commit 9f310ded "ARM: tegra: fix VBUS
      regulator GPIO polarity in DT". In the context of v3.11, this patch then
      caused the USB VBUS to actually turn off, which broke USB ports with VBUS
      control. I got this patch included in v3.11-rc1 since it fixed a bug in
      device tree (incorrect polarity specification), and hence was suitable to
      be included early in the rc series. I evidently did not test the patch at
      all, or correctly, in the context of v3.11, and hence did not notice the
      issue that I have explained above:-(
      
      Fix this by making the USB VBUS regulators always enabled. This way, if
      the regulator owns the GPIO, it will always be turned on, even if there
      is no USB driver code to request the regulator be turned on. Even
      ignoring this bug, this is a reasonable way to configure the HW anyway.
      
      If this patch is applied to v3.11, it will cause a couple pretty trivial
      conflicts in tegra20-{trimslice,seaboard}.dts when creating v3.12, since
      the context right above the added lines changed in patches destined for
      v3.12.
      
      Reported-by: default avatarKyle McMartin <kmcmarti@redhat.com>
      Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
      Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
      30ca2226
  11. Aug 20, 2013
    • David Daney's avatar
      MIPS: Handle OCTEON BBIT instructions in FPU emulator. · c26d4219
      David Daney authored
      
      The branch emulation needs to handle the OCTEON BBIT instructions,
      otherwise we get SIGILL instead of emulation.
      
      Signed-off-by: default avatarDavid Daney <david.daney@cavium.com>
      Cc: linux-mips@linux-mips.org
      Patchwork: https://patchwork.linux-mips.org/patch/5726/
      
      
      Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
      c26d4219
    • Chuck Anderson's avatar
      xen/smp: initialize IPI vectors before marking CPU online · fc78d343
      Chuck Anderson authored
      
      An older PVHVM guest (v3.0 based) crashed during vCPU hot-plug with:
      
      	kernel BUG at drivers/xen/events.c:1328!
      
      RCU has detected that a CPU has not entered a quiescent state within the
      grace period.  It needs to send the CPU a reschedule IPI if it is not
      offline.  rcu_implicit_offline_qs() does this check:
      
      	/*
      	 * If the CPU is offline, it is in a quiescent state.  We can
      	 * trust its state not to change because interrupts are disabled.
      	 */
      	if (cpu_is_offline(rdp->cpu)) {
      		rdp->offline_fqs++;
      		return 1;
      	}
      
      	Else the CPU is online.  Send it a reschedule IPI.
      
      The CPU is in the middle of being hot-plugged and has been marked online
      (!cpu_is_offline()).  See start_secondary():
      
      	set_cpu_online(smp_processor_id(), true);
      	...
      	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
      
      start_secondary() then waits for the CPU bringing up the hot-plugged CPU to
      mark it as active:
      
      	/*
      	 * Wait until the cpu which brought this one up marked it
      	 * online before enabling interrupts. If we don't do that then
      	 * we can end up waking up the softirq thread before this cpu
      	 * reached the active state, which makes the scheduler unhappy
      	 * and schedule the softirq thread on the wrong cpu. This is
      	 * only observable with forced threaded interrupts, but in
      	 * theory it could also happen w/o them. It's just way harder
      	 * to achieve.
      	 */
      	while (!cpumask_test_cpu(smp_processor_id(), cpu_active_mask))
      		cpu_relax();
      
      	/* enable local interrupts */
      	local_irq_enable();
      
      The CPU being hot-plugged will be marked active after it has been fully
      initialized by the CPU managing the hot-plug.  In the Xen PVHVM case
      xen_smp_intr_init() is called to set up the hot-plugged vCPU's
      XEN_RESCHEDULE_VECTOR.
      
      The hot-plugging CPU is marked online, not marked active and does not have
      its IPI vectors set up.  rcu_implicit_offline_qs() sees the hot-plugging
      cpu is !cpu_is_offline() and tries to send it a reschedule IPI:
      This will lead to:
      
      	kernel BUG at drivers/xen/events.c:1328!
      
      	xen_send_IPI_one()
      	xen_smp_send_reschedule()
      	rcu_implicit_offline_qs()
      	rcu_implicit_dynticks_qs()
      	force_qs_rnp()
      	force_quiescent_state()
      	__rcu_process_callbacks()
      	rcu_process_callbacks()
      	__do_softirq()
      	call_softirq()
      	do_softirq()
      	irq_exit()
      	xen_evtchn_do_upcall()
      
      because xen_send_IPI_one() will attempt to use an uninitialized IRQ for
      the XEN_RESCHEDULE_VECTOR.
      
      There is at least one other place that has caused the same crash:
      
      	xen_smp_send_reschedule()
      	wake_up_idle_cpu()
      	add_timer_on()
      	clocksource_watchdog()
      	call_timer_fn()
      	run_timer_softirq()
      	__do_softirq()
      	call_softirq()
      	do_softirq()
      	irq_exit()
      	xen_evtchn_do_upcall()
      	xen_hvm_callback_vector()
      
      clocksource_watchdog() uses cpu_online_mask to pick the next CPU to handle
      a watchdog timer:
      
      	/*
      	 * Cycle through CPUs to check if the CPUs stay synchronized
      	 * to each other.
      	 */
      	next_cpu = cpumask_next(raw_smp_processor_id(), cpu_online_mask);
      	if (next_cpu >= nr_cpu_ids)
      		next_cpu = cpumask_first(cpu_online_mask);
      	watchdog_timer.expires += WATCHDOG_INTERVAL;
      	add_timer_on(&watchdog_timer, next_cpu);
      
      This resulted in an attempt to send an IPI to a hot-plugging CPU that
      had not initialized its reschedule vector. One option would be to make
      the RCU code check to not check for CPU offline but for CPU active.
      As becoming active is done after a CPU is online (in older kernels).
      
      But Srivatsa pointed out that "the cpu_active vs cpu_online ordering has been
      completely reworked - in the online path, cpu_active is set *before* cpu_online,
      and also, in the cpu offline path, the cpu_active bit is reset in the CPU_DYING
      notification instead of CPU_DOWN_PREPARE." Drilling in this the bring-up
      path: "[brought up CPU].. send out a CPU_STARTING notification, and in response
      to that, the scheduler sets the CPU in the cpu_active_mask. Again, this mask
      is better left to the scheduler alone, since it has the intelligence to use it
      judiciously."
      
      The conclusion was that:
      "
      1. At the IPI sender side:
      
         It is incorrect to send an IPI to an offline CPU (cpu not present in
         the cpu_online_mask). There are numerous places where we check this
         and warn/complain.
      
      2. At the IPI receiver side:
      
         It is incorrect to let the world know of our presence (by setting
         ourselves in global bitmasks) until our initialization steps are complete
         to such an extent that we can handle the consequences (such as
         receiving interrupts without crashing the sender etc.)
      " (from Srivatsa)
      
      As the native code enables the interrupts at some point we need to be
      able to service them. In other words a CPU must have valid IPI vectors
      if it has been marked online.
      
      It doesn't need to handle the IPI (interrupts may be disabled) but needs
      to have valid IPI vectors because another CPU may find it in cpu_online_mask
      and attempt to send it an IPI.
      
      This patch will change the order of the Xen vCPU bring-up functions so that
      Xen vectors have been set up before start_secondary() is called.
      It also will not continue to bring up a Xen vCPU if xen_smp_intr_init() fails
      to initialize it.
      
      Orabug 13823853
      Signed-off-by Chuck Anderson <chuck.anderson@oracle.com>
      Acked-by: default avatarSrivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
      Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      fc78d343
    • David Vrabel's avatar
      x86/xen: do not identity map UNUSABLE regions in the machine E820 · 3bc38cbc
      David Vrabel authored
      
      If there are UNUSABLE regions in the machine memory map, dom0 will
      attempt to map them 1:1 which is not permitted by Xen and the kernel
      will crash.
      
      There isn't anything interesting in the UNUSABLE region that the dom0
      kernel needs access to so we can avoid making the 1:1 mapping and
      treat it as RAM.
      
      We only do this for dom0, as that is where tboot case shows up.
      A PV domU could have an UNUSABLE region in its pseudo-physical map
      and would need to be handled in another patch.
      
      This fixes a boot failure on hosts with tboot.
      
      tboot marks a region in the e820 map as unusable and the dom0 kernel
      would attempt to map this region and Xen does not permit unusable
      regions to be mapped by guests.
      
        (XEN)  0000000000000000 - 0000000000060000 (usable)
        (XEN)  0000000000060000 - 0000000000068000 (reserved)
        (XEN)  0000000000068000 - 000000000009e000 (usable)
        (XEN)  0000000000100000 - 0000000000800000 (usable)
        (XEN)  0000000000800000 - 0000000000972000 (unusable)
      
      tboot marked this region as unusable.
      
        (XEN)  0000000000972000 - 00000000cf200000 (usable)
        (XEN)  00000000cf200000 - 00000000cf38f000 (reserved)
        (XEN)  00000000cf38f000 - 00000000cf3ce000 (ACPI data)
        (XEN)  00000000cf3ce000 - 00000000d0000000 (reserved)
        (XEN)  00000000e0000000 - 00000000f0000000 (reserved)
        (XEN)  00000000fe000000 - 0000000100000000 (reserved)
        (XEN)  0000000100000000 - 0000000630000000 (usable)
      
      Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
      [v1: Altered the patch and description with domU's with UNUSABLE regions]
      Signed-off-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      3bc38cbc
    • Will Deacon's avatar
      arm64: perf: fix event validation for software group leaders · ee7538a0
      Will Deacon authored
      
      This is a port of c95eb318 ("ARM: 7809/1: perf: fix event validation
      for software group leaders") to arm64, which fixes a panic in the arm64
      perf backend found as a result of Vince's fuzzing tool.
      
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      ee7538a0
    • Will Deacon's avatar
      arm64: perf: fix array out of bounds access in armpmu_map_hw_event() · 868f6fea
      Will Deacon authored
      
      This is a port of d9f96635 ("ARM: 7810/1: perf: Fix array out of
      bounds access in armpmu_map_hw_event()") to arm64, which fixes an oops
      in the arm64 perf backend found as a result of Vince's fuzzing tool.
      
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      868f6fea
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