1. 31 5月, 2014 2 次提交
  2. 22 5月, 2014 2 次提交
  3. 21 5月, 2014 3 次提交
  4. 15 5月, 2014 1 次提交
    • L
      x86-64, modify_ldt: Make support for 16-bit segments a runtime option · fa81511b
      Linus Torvalds 提交于
      Checkin:
      
      b3b42ac2 x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels
      
      disabled 16-bit segments on 64-bit kernels due to an information
      leak.  However, it does seem that people are genuinely using Wine to
      run old 16-bit Windows programs on Linux.
      
      A proper fix for this ("espfix64") is coming in the upcoming merge
      window, but as a temporary fix, create a sysctl to allow the
      administrator to re-enable support for 16-bit segments.
      
      It adds a "/proc/sys/abi/ldt16" sysctl that defaults to zero (off). If
      you hit this issue and care about your old Windows program more than
      you care about a kernel stack address information leak, you can do
      
         echo 1 > /proc/sys/abi/ldt16
      
      as root (add it to your startup scripts), and you should be ok.
      
      The sysctl table is only added if you have COMPAT support enabled on
      x86-64, but I assume anybody who runs old windows binaries very much
      does that ;)
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      Link: http://lkml.kernel.org/r/CA%2B55aFw9BPoD10U1LfHbOMpHWZkvJTkMcfCs9s3urPr1YyWBxw@mail.gmail.com
      Cc: <stable@vger.kernel.org>
      fa81511b
  5. 14 5月, 2014 1 次提交
  6. 12 5月, 2014 1 次提交
  7. 09 5月, 2014 3 次提交
  8. 08 5月, 2014 3 次提交
  9. 07 5月, 2014 1 次提交
  10. 06 5月, 2014 9 次提交
  11. 05 5月, 2014 2 次提交
  12. 03 5月, 2014 2 次提交
    • D
      x86/efi: earlyprintk=efi,keep fix · 5f35eb0e
      Dave Young 提交于
      earlyprintk=efi,keep will cause kernel hangs while freeing initmem like
      below:
      
        VFS: Mounted root (ext4 filesystem) readonly on device 254:2.
        devtmpfs: mounted
        Freeing unused kernel memory: 880K (ffffffff817d4000 - ffffffff818b0000)
      
      It is caused by efi earlyprintk use __init function which will be freed
      later.  Such as early_efi_write is marked as __init, also it will use
      early_ioremap which is init function as well.
      
      To fix this issue, I added early initcall early_efi_map_fb which maps
      the whole efi fb for later use. OTOH, adding a wrapper function
      early_efi_map which calls early_ioremap before ioremap is available.
      
      With this patch applied efi boot ok with earlyprintk=efi,keep console=efi
      Signed-off-by: NDave Young <dyoung@redhat.com>
      Signed-off-by: NMatt Fleming <matt.fleming@intel.com>
      5f35eb0e
    • H
      x86, espfix: Fix broken header guard · 20b68535
      H. Peter Anvin 提交于
      Header guard is #ifndef, not #ifdef...
      Reported-by: NFengguang Wu <fengguang.wu@intel.com>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      20b68535
  13. 02 5月, 2014 1 次提交
  14. 01 5月, 2014 2 次提交
    • H
      x86-32, espfix: Remove filter for espfix32 due to race · 246f2d2e
      H. Peter Anvin 提交于
      It is not safe to use LAR to filter when to go down the espfix path,
      because the LDT is per-process (rather than per-thread) and another
      thread might change the descriptors behind our back.  Fortunately it
      is always *safe* (if a bit slow) to go down the espfix path, and a
      32-bit LDT stack segment is extremely rare.
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
      Cc: <stable@vger.kernel.org> # consider after upstream merge
      246f2d2e
    • H
      x86-64, espfix: Don't leak bits 31:16 of %esp returning to 16-bit stack · 3891a04a
      H. Peter Anvin 提交于
      The IRET instruction, when returning to a 16-bit segment, only
      restores the bottom 16 bits of the user space stack pointer.  This
      causes some 16-bit software to break, but it also leaks kernel state
      to user space.  We have a software workaround for that ("espfix") for
      the 32-bit kernel, but it relies on a nonzero stack segment base which
      is not available in 64-bit mode.
      
      In checkin:
      
          b3b42ac2 x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels
      
      we "solved" this by forbidding 16-bit segments on 64-bit kernels, with
      the logic that 16-bit support is crippled on 64-bit kernels anyway (no
      V86 support), but it turns out that people are doing stuff like
      running old Win16 binaries under Wine and expect it to work.
      
      This works around this by creating percpu "ministacks", each of which
      is mapped 2^16 times 64K apart.  When we detect that the return SS is
      on the LDT, we copy the IRET frame to the ministack and use the
      relevant alias to return to userspace.  The ministacks are mapped
      readonly, so if IRET faults we promote #GP to #DF which is an IST
      vector and thus has its own stack; we then do the fixup in the #DF
      handler.
      
      (Making #GP an IST exception would make the msr_safe functions unsafe
      in NMI/MC context, and quite possibly have other effects.)
      
      Special thanks to:
      
      - Andy Lutomirski, for the suggestion of using very small stack slots
        and copy (as opposed to map) the IRET frame there, and for the
        suggestion to mark them readonly and let the fault promote to #DF.
      - Konrad Wilk for paravirt fixup and testing.
      - Borislav Petkov for testing help and useful comments.
      Reported-by: NBrian Gerst <brgerst@gmail.com>
      Signed-off-by: NH. Peter Anvin <hpa@linux.intel.com>
      Link: http://lkml.kernel.org/r/1398816946-3351-1-git-send-email-hpa@linux.intel.com
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Andrew Lutomriski <amluto@gmail.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Dirk Hohndel <dirk@hohndel.org>
      Cc: Arjan van de Ven <arjan.van.de.ven@intel.com>
      Cc: comex <comexk@gmail.com>
      Cc: Alexander van Heukelum <heukelum@fastmail.fm>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: <stable@vger.kernel.org> # consider after upstream merge
      3891a04a
  15. 28 4月, 2014 3 次提交
    • T
      genirq: x86: Ensure that dynamic irq allocation does not conflict · 62a08ae2
      Thomas Gleixner 提交于
      On x86 the allocation of irq descriptors may allocate interrupts which
      are in the range of the GSI interrupts. That's wrong as those
      interrupts are hardwired and we don't have the irq domain translation
      like PPC. So one of these interrupts can be hooked up later to one of
      the devices which are hard wired to it and the io_apic init code for
      that particular interrupt line happily reuses that descriptor with a
      completely different configuration so hell breaks lose.
      
      Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs,
      except for a few usage sites which have not yet blown up in our face
      for whatever reason. But for drivers which need an irq range, like the
      GPIO drivers, we have no limit in place and we don't want to expose
      such a detail to a driver.
      
      To cure this introduce a function which an architecture can implement
      to impose a lower bound on the dynamic interrupt allocations.
      
      Implement it for x86 and set the lower bound to nr_gsi_irqs, which is
      the end of the hardwired interrupt space, so all dynamic allocations
      happen above.
      
      That not only allows the GPIO driver to work sanely, it also protects
      the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and
      htirq code. They need to be cleaned up as well, but that's a separate
      issue.
      Reported-by: NJin Yao <yao.jin@linux.intel.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Tested-by: NMika Westerberg <mika.westerberg@linux.intel.com>
      Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Grant Likely <grant.likely@linaro.org>
      Cc: H. Peter Anvin <hpa@linux.intel.com>
      Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
      Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
      Cc: Krogerus Heikki <heikki.krogerus@intel.com>
      Cc: Linus Walleij <linus.walleij@linaro.org>
      Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1404241617360.28206@ionos.tec.linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      62a08ae2
    • B
      KVM: x86: Check for host supported fields in shadow vmcs · fe2b201b
      Bandan Das 提交于
      We track shadow vmcs fields through two static lists,
      one for read only and another for r/w fields. However, with
      addition of new vmcs fields, not all fields may be supported on
      all hosts. If so, copy_vmcs12_to_shadow() trying to vmwrite on
      unsupported hosts will result in a vmwrite error. For example, commit
      36be0b9d introduced GUEST_BNDCFGS, which is not supported
      by all processors. Filter out host unsupported fields before
      letting guests use shadow vmcs
      Signed-off-by: NBandan Das <bsd@redhat.com>
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      fe2b201b
    • O
      x86/vsmp: Fix irq routing · 39025ba3
      Oren Twaig 提交于
      Correct IRQ routing in case a vSMP box is detected
      but the  Interrupt Routing Comply (IRC) value is set to
      "comply", which leads to incorrect IRQ routing.
      
      Before the patch:
      
      When a vSMP box was detected and IRC was set to "comply",
      users (and the kernel) couldn't effectively set the
      destination of the IRQs. This is because the hook inside
      vsmp_64.c always setup all CPUs as the IRQ destination using
      cpumask_setall() as the return value for IRQ allocation mask.
      Later, this "overrided" mask caused the kernel to set the IRQ
      destination to the lowest online CPU in the mask (CPU0 usually).
      
      After the patch:
      
      When the IRC is set to "comply", users (and the kernel) can control
      the destination of the IRQs as we will not be changing the
      default "apic->vector_allocation_domain".
      Signed-off-by: NOren Twaig <oren@scalemp.com>
      Acked-by: NShai Fultheim <shai@scalemp.com>
      Link: http://lkml.kernel.org/r/1398669697-2123-1-git-send-email-oren@scalemp.com
      [ Minor readability edits. ]
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      39025ba3
  16. 24 4月, 2014 1 次提交
  17. 22 4月, 2014 1 次提交
  18. 18 4月, 2014 1 次提交
  19. 17 4月, 2014 1 次提交
    • M
      kprobes/x86: Fix page-fault handling logic · 6381c24c
      Masami Hiramatsu 提交于
      Current kprobes in-kernel page fault handler doesn't
      expect that its single-stepping can be interrupted by
      an NMI handler which may cause a page fault(e.g. perf
      with callback tracing).
      
      In that case, the page-fault handled by kprobes and it
      misunderstands the page-fault has been caused by the
      single-stepping code and tries to recover IP address
      to probed address.
      
      But the truth is the page-fault has been caused by the
      NMI handler, and do_page_fault failes to handle real
      page fault because the IP address is modified and
      causes Kernel BUGs like below.
      
       ----
       [ 2264.726905] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
       [ 2264.727190] IP: [<ffffffff813c46e0>] copy_user_generic_string+0x0/0x40
      
      To handle this correctly, I fixed the kprobes fault
      handler to ensure the faulted ip address is its own
      single-step buffer instead of checking current kprobe
      state.
      Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
      Cc: Sandeepa Prabhu <sandeepa.prabhu@linaro.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: fche@redhat.com
      Cc: systemtap@sourceware.org
      Link: http://lkml.kernel.org/r/20140417081644.26341.52351.stgit@ltc230.yrl.intra.hitachi.co.jpSigned-off-by: NIngo Molnar <mingo@kernel.org>
      6381c24c