1. 04 1月, 2018 1 次提交
  2. 17 12月, 2017 4 次提交
    • A
      x86/entry/64: Make cpu_entry_area.tss read-only · c482feef
      Andy Lutomirski 提交于
      The TSS is a fairly juicy target for exploits, and, now that the TSS
      is in the cpu_entry_area, it's no longer protected by kASLR.  Make it
      read-only on x86_64.
      
      On x86_32, it can't be RO because it's written by the CPU during task
      switches, and we use a task gate for double faults.  I'd also be
      nervous about errata if we tried to make it RO even on configurations
      without double fault handling.
      
      [ tglx: AMD confirmed that there is no problem on 64-bit with TSS RO.  So
        	it's probably safe to assume that it's a non issue, though Intel
        	might have been creative in that area. Still waiting for
        	confirmation. ]
      Signed-off-by: NAndy Lutomirski <luto@kernel.org>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NBorislav Petkov <bpetkov@suse.de>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Kees Cook <keescook@chromium.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Link: https://lkml.kernel.org/r/20171204150606.733700132@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      c482feef
    • A
      x86/entry/64: Remove the SYSENTER stack canary · 7fbbd5cb
      Andy Lutomirski 提交于
      Now that the SYSENTER stack has a guard page, there's no need for a canary
      to detect overflow after the fact.
      Signed-off-by: NAndy Lutomirski <luto@kernel.org>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NBorislav Petkov <bp@suse.de>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Borislav Petkov <bpetkov@suse.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Link: https://lkml.kernel.org/r/20171204150606.572577316@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      7fbbd5cb
    • A
      x86/entry/64: Separate cpu_current_top_of_stack from TSS.sp0 · 9aaefe7b
      Andy Lutomirski 提交于
      On 64-bit kernels, we used to assume that TSS.sp0 was the current
      top of stack.  With the addition of an entry trampoline, this will
      no longer be the case.  Store the current top of stack in TSS.sp1,
      which is otherwise unused but shares the same cacheline.
      Signed-off-by: NAndy Lutomirski <luto@kernel.org>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NBorislav Petkov <bp@suse.de>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Borislav Petkov <bpetkov@suse.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Link: https://lkml.kernel.org/r/20171204150606.050864668@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      9aaefe7b
    • A
      x86/entry/64: Allocate and enable the SYSENTER stack · 1a79797b
      Andy Lutomirski 提交于
      This will simplify future changes that want scratch variables early in
      the SYSENTER handler -- they'll be able to spill registers to the
      stack.  It also lets us get rid of a SWAPGS_UNSAFE_STACK user.
      
      This does not depend on CONFIG_IA32_EMULATION=y because we'll want the
      stack space even without IA32 emulation.
      
      As far as I can tell, the reason that this wasn't done from day 1 is
      that we use IST for #DB and #BP, which is IMO rather nasty and causes
      a lot more problems than it solves.  But, since #DB uses IST, we don't
      actually need a real stack for SYSENTER (because SYSENTER with TF set
      will invoke #DB on the IST stack rather than the SYSENTER stack).
      
      I want to remove IST usage from these vectors some day, and this patch
      is a prerequisite for that as well.
      Signed-off-by: NAndy Lutomirski <luto@kernel.org>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NBorislav Petkov <bp@suse.de>
      Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Borislav Petkov <bpetkov@suse.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: David Laight <David.Laight@aculab.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Eduardo Valentin <eduval@amazon.com>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Juergen Gross <jgross@suse.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: aliguori@amazon.com
      Cc: daniel.gruss@iaik.tugraz.at
      Cc: hughd@google.com
      Cc: keescook@google.com
      Link: https://lkml.kernel.org/r/20171204150605.312726423@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1a79797b
  3. 25 11月, 2017 1 次提交
    • N
      x86/tlb: Disable interrupts when changing CR4 · 9d0b6232
      Nadav Amit 提交于
      CR4 modifications are implemented as RMW operations which update a shadow
      variable and write the result to CR4. The RMW operation is protected by
      preemption disable, but there is no enforcement or debugging mechanism.
      
      CR4 modifications happen also in interrupt context via
      __native_flush_tlb_global(). This implementation does not affect a
      interrupted thread context CR4 operation, because the CR4 toggle restores
      the original content and does not modify the shadow variable.
      
      So the current situation seems to be safe, but a recent patch tried to add
      an actual RMW operation in interrupt context, which will cause subtle
      corruptions.
      
      To prevent that and make the CR4 handling future proof:
      
       - Add a lockdep assertion to __cr4_set() which will catch interrupt
         enabled invocations
      
       - Disable interrupts in the cr4 manipulator inlines
      
       - Rename cr4_toggle_bits() to cr4_toggle_bits_irqsoff(). This is called
         from __switch_to_xtra() where interrupts are already disabled and
         performance matters.
      
      All other call sites are not performance critical, so the extra overhead of
      an additional local_irq_save/restore() pair is not a problem. If new call
      sites care about performance then the necessary _irqsoff() variants can be
      added.
      
      [ tglx: Condensed the patch by moving the irq protection inside the
        	manipulator functions. Updated changelog ]
      Signed-off-by: NNadav Amit <namit@vmware.com>
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Luck <tony.luck@intel.com>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: nadav.amit@gmail.com
      Cc: linux-edac@vger.kernel.org
      Link: https://lkml.kernel.org/r/20171125032907.2241-3-namit@vmware.com
      9d0b6232
  4. 02 11月, 2017 2 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
    • A
      x86/entry/64: Stop initializing TSS.sp0 at boot · 20bb8344
      Andy Lutomirski 提交于
      In my quest to get rid of thread_struct::sp0, I want to clean up or
      remove all of its readers.  Two of them are in cpu_init() (32-bit and
      64-bit), and they aren't needed.  This is because we never enter
      userspace at all on the threads that CPUs are initialized in.
      
      Poison the initial TSS.sp0 and stop initializing it on CPU init.
      
      The comment text mostly comes from Dave Hansen.  Thanks!
      Signed-off-by: NAndy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bpetkov@suse.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/ee4a00540ad28c6cff475fbcc7769a4460acc861.1509609304.git.luto@kernel.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
      20bb8344
  5. 18 7月, 2017 1 次提交
    • T
      x86/mm, kexec: Allow kexec to be used with SME · bba4ed01
      Tom Lendacky 提交于
      Provide support so that kexec can be used to boot a kernel when SME is
      enabled.
      
      Support is needed to allocate pages for kexec without encryption.  This
      is needed in order to be able to reboot in the kernel in the same manner
      as originally booted.
      
      Additionally, when shutting down all of the CPUs we need to be sure to
      flush the caches and then halt. This is needed when booting from a state
      where SME was not active into a state where SME is active (or vice-versa).
      Without these steps, it is possible for cache lines to exist for the same
      physical location but tagged both with and without the encryption bit. This
      can cause random memory corruption when caches are flushed depending on
      which cacheline is written last.
      Signed-off-by: NTom Lendacky <thomas.lendacky@amd.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NBorislav Petkov <bp@suse.de>
      Cc: <kexec@lists.infradead.org>
      Cc: Alexander Potapenko <glider@google.com>
      Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brijesh Singh <brijesh.singh@amd.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: Dmitry Vyukov <dvyukov@google.com>
      Cc: Jonathan Corbet <corbet@lwn.net>
      Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
      Cc: Larry Woodman <lwoodman@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Matt Fleming <matt@codeblueprint.co.uk>
      Cc: Michael S. Tsirkin <mst@redhat.com>
      Cc: Paolo Bonzini <pbonzini@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Radim Krčmář <rkrcmar@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Toshimitsu Kani <toshi.kani@hpe.com>
      Cc: kasan-dev@googlegroups.com
      Cc: kvm@vger.kernel.org
      Cc: linux-arch@vger.kernel.org
      Cc: linux-doc@vger.kernel.org
      Cc: linux-efi@vger.kernel.org
      Cc: linux-mm@kvack.org
      Link: http://lkml.kernel.org/r/b95ff075db3e7cd545313f2fb609a49619a09625.1500319216.git.thomas.lendacky@amd.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      bba4ed01
  6. 29 6月, 2017 1 次提交
  7. 20 3月, 2017 2 次提交
    • K
      x86/arch_prctl: Add ARCH_[GET|SET]_CPUID · e9ea1e7f
      Kyle Huey 提交于
      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: NKyle 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: NThomas Gleixner <tglx@linutronix.de>
      e9ea1e7f
    • K
      x86/arch_prctl: Add do_arch_prctl_common() · b0b9b014
      Kyle Huey 提交于
      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: NKyle 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: NThomas Gleixner <tglx@linutronix.de>
      b0b9b014
  8. 11 3月, 2017 3 次提交
  9. 02 3月, 2017 5 次提交
  10. 21 2月, 2017 1 次提交
    • A
      x86/kvm/vmx: Defer TR reload after VM exit · b7ffc44d
      Andy Lutomirski 提交于
      Intel's VMX is daft and resets the hidden TSS limit register to 0x67
      on VMX reload, and the 0x67 is not configurable.  KVM currently
      reloads TR using the LTR instruction on every exit, but this is quite
      slow because LTR is serializing.
      
      The 0x67 limit is entirely harmless unless ioperm() is in use, so
      defer the reload until a task using ioperm() is actually running.
      
      Here's some poorly done benchmarking using kvm-unit-tests:
      
      Before:
      
      cpuid 1313
      vmcall 1195
      mov_from_cr8 11
      mov_to_cr8 17
      inl_from_pmtimer 6770
      inl_from_qemu 6856
      inl_from_kernel 2435
      outl_to_kernel 1402
      
      After:
      
      cpuid 1291
      vmcall 1181
      mov_from_cr8 11
      mov_to_cr8 16
      inl_from_pmtimer 6457
      inl_from_qemu 6209
      inl_from_kernel 2339
      outl_to_kernel 1391
      Signed-off-by: NAndy Lutomirski <luto@kernel.org>
      [Force-reload TR in invalidate_tss_limit. - Paolo]
      Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      b7ffc44d
  11. 25 12月, 2016 1 次提交
  12. 15 12月, 2016 1 次提交
  13. 10 12月, 2016 4 次提交
    • T
      x86: Remove empty idle.h header · 34bc3560
      Thomas Gleixner 提交于
      One include less is always a good thing(tm). Good riddance.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20161209182912.2726-6-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      34bc3560
    • B
      x86/amd: Simplify AMD E400 aware idle routine · 07c94a38
      Borislav Petkov 提交于
      Reorganize the E400 detection now that we have everything in place:
      switch the CPUs to broadcast mode after the LAPIC has been initialized
      and remove the facilities that were used previously on the idle path.
      
      Unfortunately static_cpu_has_bug() cannpt be used in the E400 idle routine
      because alternatives have been applied when the actual detection happens,
      so the static switching does not take effect and the test will stay
      false. Use boot_cpu_has_bug() instead which is definitely an improvement
      over the RDMSR and the cpumask handling.
      Suggested-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20161209182912.2726-5-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      07c94a38
    • T
      x86/amd: Check for the C1E bug post ACPI subsystem init · e7ff3a47
      Thomas Gleixner 提交于
      AMD CPUs affected by the E400 erratum suffer from the issue that the
      local APIC timer stops when the CPU goes into C1E. Unfortunately there
      is no way to detect the affected CPUs on early boot. It's only possible
      to determine the range of possibly affected CPUs from the family/model
      range.
      
      The actual decision whether to enter C1E and thus cause the bug is done
      by the firmware and we need to detect that case late, after ACPI has
      been initialized.
      
      The current solution is to check in the idle routine whether the CPU is
      affected by reading the MSR_K8_INT_PENDING_MSG MSR and checking for the
      K8_INTP_C1E_ACTIVE_MASK bits. If one of the bits is set then the CPU is
      affected and the system is switched into forced broadcast mode.
      
      This is ineffective and on non-affected CPUs every entry to idle does
      the extra RDMSR.
      
      After doing some research it turns out that the bits are visible on the
      boot CPU right after the ACPI subsystem is initialized in the early
      boot process. So instead of polling for the bits in the idle loop, add
      a detection function after acpi_subsystem_init() and check for the MSR
      bits. If set, then the X86_BUG_AMD_APIC_C1E is set on the boot CPU and
      the TSC is marked unstable when X86_FEATURE_NONSTOP_TSC is not set as it
      will stop in C1E state as well.
      
      The switch to broadcast mode cannot be done at this point because the
      boot CPU still uses HPET as a clockevent device and the local APIC timer
      is not yet calibrated and installed. The switch to broadcast mode on the
      affected CPUs needs to be done when the local APIC timer is actually set
      up.
      
      This allows to cleanup the amd_e400_idle() function in the next step.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20161209182912.2726-4-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      e7ff3a47
    • T
      x86/bugs: Separate AMD E400 erratum and C1E bug · 3344ed30
      Thomas Gleixner 提交于
      The workaround for the AMD Erratum E400 (Local APIC timer stops in C1E
      state) is a two step process:
      
       - Selection of the E400 aware idle routine
      
       - Detection whether the platform is affected
      
      The idle routine selection happens for possibly affected CPUs depending on
      family/model/stepping information. These range of CPUs is not necessarily
      affected as the decision whether to enable the C1E feature is made by the
      firmware. Unfortunately there is no way to query this at early boot.
      
      The current implementation polls a MSR in the E400 aware idle routine to
      detect whether the CPU is affected. This is inefficient on non affected
      CPUs because every idle entry has to do the MSR read.
      
      There is a better way to detect this before going idle for the first time
      which requires to seperate the bug flags:
      
        X86_BUG_AMD_E400 	- Selects the E400 aware idle routine and
        			  enables the detection
      			  
        X86_BUG_AMD_APIC_C1E  - Set when the platform is affected by E400
      
      Replace the current X86_BUG_AMD_APIC_C1E usage by the new X86_BUG_AMD_E400
      bug bit to select the idle routine which currently does an unconditional
      detection poll. X86_BUG_AMD_APIC_C1E is going to be used in later patches
      to remove the MSR polling and simplify the handling of this misfeature.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Link: http://lkml.kernel.org/r/20161209182912.2726-3-bp@alien8.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      3344ed30
  14. 30 11月, 2016 1 次提交
    • T
      x86/tsc: Verify TSC_ADJUST from idle · 1d0095fe
      Thomas Gleixner 提交于
      When entering idle, it's a good oportunity to verify that the TSC_ADJUST
      MSR has not been tampered with (BIOS hiding SMM cycles). If tampering is
      detected, emit a warning and restore it to the previous value.
      
      This is especially important for machines, which mark the TSC reliable
      because there is no watchdog clocksource available (SoCs).
      
      This is not sufficient for HPC (NOHZ_FULL) situations where a CPU never
      goes idle, but adding a timer to do the check periodically is not an option
      either. On a machine, which has this issue, the check triggeres right
      during boot, so there is a decent chance that the sysadmin will notice.
      
      Rate limit the check to once per second and warn only once per cpu.
      Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
      Reviewed-by: NIngo Molnar <mingo@kernel.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Link: http://lkml.kernel.org/r/20161119134017.732180441@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      1d0095fe
  15. 18 11月, 2016 3 次提交
  16. 12 10月, 2016 1 次提交
  17. 08 10月, 2016 1 次提交
  18. 16 9月, 2016 1 次提交
  19. 15 9月, 2016 1 次提交
  20. 24 8月, 2016 2 次提交
  21. 20 7月, 2016 1 次提交
  22. 14 7月, 2016 1 次提交
    • P
      x86/kernel: Audit and remove any unnecessary uses of module.h · 186f4360
      Paul Gortmaker 提交于
      Historically a lot of these existed because we did not have
      a distinction between what was modular code and what was providing
      support to modules via EXPORT_SYMBOL and friends.  That changed
      when we forked out support for the latter into the export.h file.
      
      This means we should be able to reduce the usage of module.h
      in code that is obj-y Makefile or bool Kconfig.  The advantage
      in doing so is that module.h itself sources about 15 other headers;
      adding significantly to what we feed cpp, and it can obscure what
      headers we are effectively using.
      
      Since module.h was the source for init.h (for __init) and for
      export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
      for the presence of either and replace as needed.  Build testing
      revealed some implicit header usage that was fixed up accordingly.
      
      Note that some bool/obj-y instances remain since module.h is
      the header for some exception table entry stuff, and for things
      like __init_or_module (code that is tossed when MODULES=n).
      Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/20160714001901.31603-4-paul.gortmaker@windriver.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      186f4360
  23. 21 5月, 2016 1 次提交
    • J
      exit_thread: accept a task parameter to be exited · e6464694
      Jiri Slaby 提交于
      We need to call exit_thread from copy_process in a fail path.  So make it
      accept task_struct as a parameter.
      
      [v2]
      * s390: exit_thread_runtime_instr doesn't make sense to be called for
        non-current tasks.
      * arm: fix the comment in vfp_thread_copy
      * change 'me' to 'tsk' for task_struct
      * now we can change only archs that actually have exit_thread
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NJiri Slaby <jslaby@suse.cz>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
      Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Chen Liqin <liqin.linux@gmail.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
      Cc: Hans-Christian Egtvedt <egtvedt@samfundet.no>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Helge Deller <deller@gmx.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: James Hogan <james.hogan@imgtec.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Jesper Nilsson <jesper.nilsson@axis.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Jonas Bonn <jonas@southpole.se>
      Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
      Cc: Lennox Wu <lennox.wu@gmail.com>
      Cc: Ley Foon Tan <lftan@altera.com>
      Cc: Mark Salter <msalter@redhat.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Matt Turner <mattst88@gmail.com>
      Cc: Max Filippov <jcmvbkbc@gmail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: Michal Simek <monstr@monstr.eu>
      Cc: Mikael Starvik <starvik@axis.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Rich Felker <dalias@libc.org>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Richard Kuo <rkuo@codeaurora.org>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Steven Miao <realmz6@gmail.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Vineet Gupta <vgupta@synopsys.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e6464694