1. 11 Feb, 2016 1 commit
  2. 08 Feb, 2016 1 commit
    • Andre Przywara's avatar
      KVM: arm/arm64: Fix reference to uninitialised VGIC · b3aff6cc
      Andre Przywara authored
      Commit 4b4b4512 ("arm/arm64: KVM: Rework the arch timer to use
      level-triggered semantics") brought the virtual architected timer
      closer to the VGIC. There is one occasion were we don't properly
      check for the VGIC actually having been initialized before, but
      instead go on to check the active state of some IRQ number.
      If userland hasn't instantiated a virtual GIC, we end up with a
      kernel NULL pointer dereference:
      =========
      Unable to handle kernel NULL pointer dereference at virtual address 00000000
      pgd = ffffffc9745c5000
      [00000000] *pgd=00000009f631e003, *pud=00000009f631e003, *pmd=0000000000000000
      Internal error: Oops: 96000006 [#2] PREEMPT SMP
      Modules linked in:
      CPU: 0 PID: 2144 Comm: kvm_simplest-ar Tainted: G      D 4.5.0-rc2+ #1300
      Hardware name: ARM Juno development board (r1) (DT)
      task: ffffffc976da8000 ti: ffffffc976e28000 task.ti: ffffffc976e28000
      PC is at vgic_bitmap_get_irq_val+0x78/0x90
      LR is at kvm_vgic_map_is_active+0xac/0xc8
      pc : [<ffffffc0000b7e28>] lr : [<ffffffc0000b972c>] pstate: 20000145
      ....
      =========
      
      Fix this by bailing out early of kvm_timer_flush_hwstate() if we don't
      have a VGIC at all.
      Reported-by: default avatarCosmin Gorgovan <cosmin@linux-geek.org>
      Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarAndre Przywara <andre.przywara@arm.com>
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Cc: <stable@vger.kernel.org> # 4.4.x
      b3aff6cc
  3. 24 Jan, 2016 38 commits