1. 31 Mar, 2017 1 commit
    • Borislav Petkov's avatar
      x86/boot/32: Flip the logic in test_wp_bit() · 952a6c2c
      Borislav Petkov authored
      ... to have a natural "likely()" in the code flow and thus have the
      success case with a branch 99.999% of the times non-taken and function
      return code following it instead of jumping to it each time.
      
      This puts the panic() call at the end of the function - it is going to
      be practically unreachable anyway.
      
      The C code is a bit more readable too.
      
      No functionality change.
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: boris.ostrovsky@oracle.com
      Cc: jgross@suse.com
      Cc: thgarnie@google.com
      Link: http://lkml.kernel.org/r/20170330080101.ywsf5rg6ilzu4itk@pd.tnicSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
      952a6c2c
  2. 30 Mar, 2017 3 commits
  3. 28 Mar, 2017 1 commit
  4. 27 Mar, 2017 6 commits
  5. 23 Mar, 2017 7 commits
  6. 21 Mar, 2017 2 commits
  7. 20 Mar, 2017 8 commits
    • Kyle Huey's avatar
      x86/arch_prctl: Add ARCH_[GET|SET]_CPUID · e9ea1e7f
      Kyle Huey authored
      Intel supports faulting on the CPUID instruction beginning with Ivy Bridge.
      When enabled, the processor will fault on attempts to execute the CPUID
      instruction with CPL>0. Exposing this feature to userspace will allow a
      ptracer to trap and emulate the CPUID instruction.
      
      When supported, this feature is controlled by toggling bit 0 of
      MSR_MISC_FEATURES_ENABLES. It is documented in detail in Section 2.3.2 of
      https://bugzilla.kernel.org/attachment.cgi?id=243991
      
      Implement a new pair of arch_prctls, available on both x86-32 and x86-64.
      
      ARCH_GET_CPUID: Returns the current CPUID state, either 0 if CPUID faulting
          is enabled (and thus the CPUID instruction is not available) or 1 if
          CPUID faulting is not enabled.
      
      ARCH_SET_CPUID: Set the CPUID state to the second argument. If
          cpuid_enabled is 0 CPUID faulting will be activated, otherwise it will
          be deactivated. Returns ENODEV if CPUID faulting is not supported on
          this system.
      
      The state of the CPUID faulting flag is propagated across forks, but reset
      upon exec.
      Signed-off-by: default avatarKyle Huey <khuey@kylehuey.com>
      Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
      Cc: kvm@vger.kernel.org
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: linux-kselftest@vger.kernel.org
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Robert O'Callahan <robert@ocallahan.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Len Brown <len.brown@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: user-mode-linux-devel@lists.sourceforge.net
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: user-mode-linux-user@lists.sourceforge.net
      Cc: David Matlack <dmatlack@google.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
      Cc: linux-fsdevel@vger.kernel.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Link: http://lkml.kernel.org/r/20170320081628.18952-9-khuey@kylehuey.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      e9ea1e7f
    • Kyle Huey's avatar
      x86/cpufeature: Detect CPUID faulting support · 90218ac7
      Kyle Huey authored
      Intel supports faulting on the CPUID instruction beginning with Ivy Bridge.
      When enabled, the processor will fault on attempts to execute the CPUID
      instruction with CPL>0. This will allow a ptracer to emulate the CPUID
      instruction.
      
      Bit 31 of MSR_PLATFORM_INFO advertises support for this feature. It is
      documented in detail in Section 2.3.2 of
      https://bugzilla.kernel.org/attachment.cgi?id=243991
      
      Detect support for this feature and expose it as X86_FEATURE_CPUID_FAULT.
      Signed-off-by: default avatarKyle Huey <khuey@kylehuey.com>
      Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
      Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
      Cc: kvm@vger.kernel.org
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: linux-kselftest@vger.kernel.org
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Robert O'Callahan <robert@ocallahan.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Len Brown <len.brown@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: user-mode-linux-devel@lists.sourceforge.net
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: user-mode-linux-user@lists.sourceforge.net
      Cc: David Matlack <dmatlack@google.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
      Cc: linux-fsdevel@vger.kernel.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Link: http://lkml.kernel.org/r/20170320081628.18952-8-khuey@kylehuey.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      90218ac7
    • Kyle Huey's avatar
      x86/syscalls/32: Wire up arch_prctl on x86-32 · 79170fda
      Kyle Huey authored
      Hook up arch_prctl to call do_arch_prctl() on x86-32, and in 32 bit compat
      mode on x86-64. This allows to have arch_prctls that are not specific to 64
      bits.
      
      On UML, simply stub out this syscall.
      Signed-off-by: default avatarKyle Huey <khuey@kylehuey.com>
      Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
      Cc: kvm@vger.kernel.org
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: linux-kselftest@vger.kernel.org
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Robert O'Callahan <robert@ocallahan.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Len Brown <len.brown@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: user-mode-linux-devel@lists.sourceforge.net
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: user-mode-linux-user@lists.sourceforge.net
      Cc: David Matlack <dmatlack@google.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
      Cc: linux-fsdevel@vger.kernel.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Link: http://lkml.kernel.org/r/20170320081628.18952-7-khuey@kylehuey.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      79170fda
    • Kyle Huey's avatar
      x86/arch_prctl: Add do_arch_prctl_common() · b0b9b014
      Kyle Huey authored
      Add do_arch_prctl_common() to handle arch_prctls that are not specific to 64
      bit mode. Call it from the syscall entry point, but not any of the other
      callsites in the kernel, which all want one of the existing 64 bit only
      arch_prctls.
      Signed-off-by: default avatarKyle Huey <khuey@kylehuey.com>
      Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
      Cc: kvm@vger.kernel.org
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: linux-kselftest@vger.kernel.org
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Robert O'Callahan <robert@ocallahan.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Len Brown <len.brown@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: user-mode-linux-devel@lists.sourceforge.net
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: user-mode-linux-user@lists.sourceforge.net
      Cc: David Matlack <dmatlack@google.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
      Cc: linux-fsdevel@vger.kernel.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Link: http://lkml.kernel.org/r/20170320081628.18952-6-khuey@kylehuey.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      b0b9b014
    • Kyle Huey's avatar
      x86/arch_prctl/64: Rename do_arch_prctl() to do_arch_prctl_64() · 17a6e1b8
      Kyle Huey authored
      In order to introduce new arch_prctls that are not 64 bit only, rename the
      existing 64 bit implementation to do_arch_prctl_64(). Also rename the
      second argument of that function from 'addr' to 'arg2', because it will no
      longer always be an address.
      Signed-off-by: default avatarKyle Huey <khuey@kylehuey.com>
      Reviewed-by: default avatarAndy Lutomirski <luto@kernel.org>
      Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
      Cc: kvm@vger.kernel.org
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: linux-kselftest@vger.kernel.org
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Robert O'Callahan <robert@ocallahan.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Len Brown <len.brown@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: user-mode-linux-devel@lists.sourceforge.net
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: user-mode-linux-user@lists.sourceforge.net
      Cc: David Matlack <dmatlack@google.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
      Cc: linux-fsdevel@vger.kernel.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Link: http://lkml.kernel.org/r/20170320081628.18952-5-khuey@kylehuey.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      17a6e1b8
    • Kyle Huey's avatar
      x86/arch_prctl/64: Use SYSCALL_DEFINE2 to define sys_arch_prctl() · ff3f097e
      Kyle Huey authored
      Use the SYSCALL_DEFINE2 macro instead of manually defining it.
      Signed-off-by: default avatarKyle Huey <khuey@kylehuey.com>
      Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
      Cc: kvm@vger.kernel.org
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: linux-kselftest@vger.kernel.org
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Robert O'Callahan <robert@ocallahan.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Len Brown <len.brown@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: user-mode-linux-devel@lists.sourceforge.net
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: user-mode-linux-user@lists.sourceforge.net
      Cc: David Matlack <dmatlack@google.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
      Cc: linux-fsdevel@vger.kernel.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Link: http://lkml.kernel.org/r/20170320081628.18952-4-khuey@kylehuey.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      ff3f097e
    • Kyle Huey's avatar
      x86/arch_prctl: Rename 'code' argument to 'option' · dd93938a
      Kyle Huey authored
      The x86 specific arch_prctl() arbitrarily changed prctl's 'option' to
      'code'. Before adding new options, rename it.
      Signed-off-by: default avatarKyle Huey <khuey@kylehuey.com>
      Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
      Cc: kvm@vger.kernel.org
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: linux-kselftest@vger.kernel.org
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Robert O'Callahan <robert@ocallahan.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Len Brown <len.brown@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: user-mode-linux-devel@lists.sourceforge.net
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: user-mode-linux-user@lists.sourceforge.net
      Cc: David Matlack <dmatlack@google.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
      Cc: linux-fsdevel@vger.kernel.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Link: http://lkml.kernel.org/r/20170320081628.18952-3-khuey@kylehuey.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      dd93938a
    • Kyle Huey's avatar
      x86/msr: Rename MISC_FEATURE_ENABLES to MISC_FEATURES_ENABLES · ab6d9468
      Kyle Huey authored
      This matches the only public Intel documentation of this MSR, in the
      "Virtualization Technology FlexMigration Application Note"
      (preserved at https://bugzilla.kernel.org/attachment.cgi?id=243991)
      Signed-off-by: default avatarKyle Huey <khuey@kylehuey.com>
      Cc: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
      Cc: kvm@vger.kernel.org
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Andi Kleen <andi@firstfloor.org>
      Cc: linux-kselftest@vger.kernel.org
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Robert O'Callahan <robert@ocallahan.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Len Brown <len.brown@intel.com>
      Cc: Shuah Khan <shuah@kernel.org>
      Cc: user-mode-linux-devel@lists.sourceforge.net
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: user-mode-linux-user@lists.sourceforge.net
      Cc: David Matlack <dmatlack@google.com>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Dmitry Safonov <dsafonov@virtuozzo.com>
      Cc: linux-fsdevel@vger.kernel.org
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Link: http://lkml.kernel.org/r/20170320081628.18952-2-khuey@kylehuey.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      ab6d9468
  8. 19 Mar, 2017 1 commit
    • Andy Lutomirski's avatar
      x86/tls: Forcibly set the accessed bit in TLS segments · 5b781c7e
      Andy Lutomirski authored
      For mysterious historical reasons, struct user_desc doesn't indicate
      whether segments are accessed.  set_thread_area() has always programmed
      segments as non-accessed, so the first write will set the accessed bit.
      This will fault if the GDT is read-only.
      
      Fix it by making TLS segments start out accessed.
      
      If this ends up breaking something, we could, in principle, leave TLS
      segments non-accessed and fix them up when we get the page fault.  I'd be
      surprised, though -- AFAIK all the nasty legacy segmented programs (DOSEMU,
      Wine, things that run on DOSEMU and Wine, etc.) do their nasty segmented
      things using the LDT and not the GDT.  I assume this is mainly because old
      OSes (Linux and otherwise) didn't historically provide APIs to do nasty
      things in the GDT.
      
      Fixes: 45fc8757 ("x86: Make the GDT remapping read-only on 64-bit")
      Signed-off-by: default avatarAndy Lutomirski <luto@kernel.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Thomas Garnier <thgarnie@google.com>
      Link: http://lkml.kernel.org/r/62b7748542df0164af7e0a5231283b9b13858c45.1489900519.git.luto@kernel.orgSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      5b781c7e
  9. 18 Mar, 2017 8 commits
  10. 17 Mar, 2017 1 commit
  11. 16 Mar, 2017 2 commits