1. 08 10月, 2016 1 次提交
    • D
      x86/pkeys: Make protection keys an "eager" feature · d4b05923
      Dave Hansen 提交于
      Our XSAVE features are divided into two categories: those that
      generate FPU exceptions, and those that do not.  MPX and pkeys do
      not generate FPU exceptions and thus can not be used lazily.  We
      disable them when lazy mode is forced on.
      
      We have a pair of masks to collect these two sets of features, but
      XFEATURE_MASK_PKRU was added to the wrong mask: XFEATURE_MASK_LAZY.
      Fix it by moving the feature to XFEATURE_MASK_EAGER.
      
      Note: this only causes problem if you boot with lazy FPU mode
      (eagerfpu=off) which is *not* the default.  It also only affects
      hardware which is not currently publicly available.  It looks like
      eager mode is going away, but we still need this patch applied
      to any kernel that has protection keys and lazy mode, which is 4.6
      through 4.8 at this point, and 4.9 if the lazy removal isn't sent
      to Linus for 4.9.
      
      Fixes: c8df4009 ("x86/fpu, x86/mm/pkeys: Add PKRU xsave fields and data structures")
      Signed-off-by: NDave Hansen <dave.hansen@intel.com>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: stable@vger.kernel.org
      Link: http://lkml.kernel.org/r/20161007162342.28A49813@viggo.jf.intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      d4b05923
  2. 10 8月, 2016 1 次提交
    • K
      x86: Apply more __ro_after_init and const · 404f6aac
      Kees Cook 提交于
      Guided by grsecurity's analogous __read_only markings in arch/x86,
      this applies several uses of __ro_after_init to structures that are
      only updated during __init, and const for some structures that are
      never updated.  Additionally extends __init markings to some functions
      that are only used during __init, and cleans up some missing C99 style
      static initializers.
      Signed-off-by: NKees Cook <keescook@chromium.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brad Spengler <spender@grsecurity.net>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: David Brown <david.brown@linaro.org>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Emese Revfy <re.emese@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mathias Krause <minipli@googlemail.com>
      Cc: Michael Ellerman <mpe@ellerman.id.au>
      Cc: PaX Team <pageexec@freemail.hu>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: kernel-hardening@lists.openwall.com
      Link: http://lkml.kernel.org/r/20160808232906.GA29731@www.outflux.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      404f6aac
  3. 10 7月, 2016 2 次提交
    • Y
      x86/fpu/xstate: Fix PTRACE frames for XSAVES · 91c3dba7
      Yu-cheng Yu 提交于
      XSAVES uses compacted format and is a kernel instruction. The kernel
      should use standard-format, non-supervisor state data for PTRACE.
      Signed-off-by: NYu-cheng Yu <yu-cheng.yu@intel.com>
      [ Edited away artificial linebreaks. ]
      Reviewed-by: NDave Hansen <dave.hansen@intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
      Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
      Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/de3d80949001305fe389799973b675cab055c457.1466179491.git.yu-cheng.yu@intel.com
      [ Made various readability edits. ]
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      91c3dba7
    • Y
      x86/fpu/xstate: Fix supervisor xstate component offset · 1499ce2d
      Yu-cheng Yu 提交于
      CPUID function 0x0d, sub function (i, i > 1) returns in ebx the offset of
      xstate component i. Zero is returned for a supervisor state. A supervisor
      state can only be saved by XSAVES and XSAVES uses a compacted format.
      There is no fixed offset for a supervisor state. This patch checks and
      makes sure a supervisor state offset is not recorded or mis-used. This has
      no effect in practice as we currently use no supervisor states, but it
      would be good to fix.
      Signed-off-by: NYu-cheng Yu <yu-cheng.yu@intel.com>
      Reviewed-by: NDave Hansen <dave.hansen@intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Josh Poimboeuf <jpoimboe@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
      Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
      Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/81b29e40d35d4cec9f2511a856fe769f34935a3f.1466179491.git.yu-cheng.yu@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      1499ce2d
  4. 18 6月, 2016 2 次提交
  5. 10 3月, 2016 1 次提交
    • Y
      x86/fpu: Revert ("x86/fpu: Disable AVX when eagerfpu is off") · a65050c6
      Yu-cheng Yu 提交于
      Leonid Shatz noticed that the SDM interpretation of the following
      recent commit:
      
        394db20c ("x86/fpu: Disable AVX when eagerfpu is off")
      
      ... is incorrect and that the original behavior of the FPU code was correct.
      
      Because AVX is not stated in CR0 TS bit description, it was mistakenly
      believed to be not supported for lazy context switch. This turns out
      to be false:
      
        Intel Software Developer's Manual Vol. 3A, Sec. 2.5 Control Registers:
      
         'TS Task Switched bit (bit 3 of CR0) -- Allows the saving of the x87 FPU/
          MMX/SSE/SSE2/SSE3/SSSE3/SSE4 context on a task switch to be delayed until
          an x87 FPU/MMX/SSE/SSE2/SSE3/SSSE3/SSE4 instruction is actually executed
          by the new task.'
      
        Intel Software Developer's Manual Vol. 2A, Sec. 2.4 Instruction Exception
        Specification:
      
         'AVX instructions refer to exceptions by classes that include #NM
          "Device Not Available" exception for lazy context switch.'
      
      So revert the commit.
      Reported-by: NLeonid Shatz <leonid.shatz@ravellosystems.com>
      Signed-off-by: NYu-cheng Yu <yu-cheng.yu@intel.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
      Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Link: http://lkml.kernel.org/r/1457569734-3785-1-git-send-email-yu-cheng.yu@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      a65050c6
  6. 16 2月, 2016 1 次提交
  7. 12 1月, 2016 1 次提交
    • Y
      x86/fpu: Disable AVX when eagerfpu is off · 394db20c
      yu-cheng yu 提交于
      When "eagerfpu=off" is given as a command-line input, the kernel
      should disable AVX support.
      
      The Task Switched bit used for lazy context switching does not
      support AVX. If AVX is enabled without eagerfpu context
      switching, one task's AVX state could become corrupted or leak
      to other tasks. This is a bug and has bad security implications.
      
      This only affects systems that have AVX/AVX2/AVX512 and this
      issue will be found only when one actually uses AVX/AVX2/AVX512
      _AND_ does eagerfpu=off.
      
      Reference: Intel Software Developer's Manual Vol. 3A
      
      Sec. 2.5 Control Registers:
      TS Task Switched bit (bit 3 of CR0) -- Allows the saving of the
      x87 FPU/ MMX/SSE/SSE2/SSE3/SSSE3/SSE4 context on a task switch
      to be delayed until an x87 FPU/MMX/SSE/SSE2/SSE3/SSSE3/SSE4
      instruction is actually executed by the new task.
      
      Sec. 13.4.1 Using the TS Flag to Control the Saving of the X87
      FPU and SSE State
      When the TS flag is set, the processor monitors the instruction
      stream for x87 FPU, MMX, SSE instructions. When the processor
      detects one of these instructions, it raises a
      device-not-available exeception (#NM) prior to executing the
      instruction.
      Signed-off-by: NYu-cheng Yu <yu-cheng.yu@intel.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
      Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
      Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: yu-cheng yu <yu-cheng.yu@intel.com>
      Link: http://lkml.kernel.org/r/1452119094-7252-5-git-send-email-yu-cheng.yu@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      394db20c
  8. 14 9月, 2015 2 次提交
    • D
      x86/fpu: Rename XSAVE macros · d91cab78
      Dave Hansen 提交于
      There are two concepts that have some confusing naming:
       1. Extended State Component numbers (currently called
          XFEATURE_BIT_*)
       2. Extended State Component masks (currently called XSTATE_*)
      
      The numbers are (currently) from 0-9.  State component 3 is the
      bounds registers for MPX, for instance.
      
      But when we want to enable "state component 3", we go set a bit
      in XCR0.  The bit we set is 1<<3.  We can check to see if a
      state component feature is enabled by looking at its bit.
      
      The current 'xfeature_bit's are at best xfeature bit _numbers_.
      Calling them bits is at best inconsistent with ending the enum
      list with 'XFEATURES_NR_MAX'.
      
      This patch renames the enum to be 'xfeature'.  These also
      happen to be what the Intel documentation calls a "state
      component".
      
      We also want to differentiate these from the "XSTATE_*" macros.
      The "XSTATE_*" macros are a mask, and we rename them to match.
      
      These macros are reasonably widely used so this patch is a
      wee bit big, but this really is just a rename.
      
      The only non-mechanical part of this is the
      
      	s/XSTATE_EXTEND_MASK/XFEATURE_MASK_EXTEND/
      
      We need a better name for it, but that's another patch.
      Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: dave@sr71.net
      Cc: linux-kernel@vger.kernel.org
      Link: http://lkml.kernel.org/r/20150902233126.38653250@viggo.jf.intel.com
      [ Ported to v4.3-rc1. ]
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      d91cab78
    • D
      x86/fpu: Move XSAVE-disabling code to a helper · 0a265375
      Dave Hansen 提交于
      When we want to _completely_ disable XSAVE support as far as
      the kernel is concerned, we have a big set of feature flags
      to clear.  We currently only do this in cases where the user
      asks for it to be disabled, but we are about to expand the
      places where we do it to handle errors too.
      
      Move the code in to xstate.c, and put it in the xstate.h
      header.  We will use it in the next patch too.
      Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Brian Gerst <brgerst@gmail.com>
      Cc: Denys Vlasenko <dvlasenk@redhat.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Tim Chen <tim.c.chen@linux.intel.com>
      Cc: dave@sr71.net
      Cc: linux-kernel@vger.kernel.org
      Link: http://lkml.kernel.org/r/20150902233124.EA9A70E5@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      0a265375
  9. 09 6月, 2015 1 次提交
    • D
      x86/fpu/xstate: Wrap get_xsave_addr() to make it safer · 04cd027b
      Dave Hansen 提交于
      The MPX code appears is calling a low-level FPU function
      (copy_fpregs_to_fpstate()).  This function is not able to
      be called in all contexts, although it is safe to call
      directly in some cases.
      
      Although probably correct, the current code is ugly and
      potentially error-prone.  So, add a wrapper that calls
      the (slightly) higher-level fpu__save() (which is preempt-
      safe) and also ensures that we even *have* an FPU context
      (in the case that this was called when in lazy FPU mode).
      
      Ingo had this to say about the details about when we need
      preemption disabled:
      
      > it's indeed generally unsafe to access/copy FPU registers with preemption enabled,
      > for two reasons:
      >
      >   - on older systems that use FSAVE the instruction destroys FPU register
      >     contents, which has to be handled carefully
      >
      >   - even on newer systems if we copy to FPU registers (which this code doesn't)
      >     then we don't want a context switch to occur in the middle of it, because a
      >     context switch will write to the fpstate, potentially overwriting our new data
      >     with old FPU state.
      >
      > But it's safe to access FPU registers with preemption enabled in a couple of
      > special cases:
      >
      >   - potentially destructively saving FPU registers: the signal handling code does
      >     this in copy_fpstate_to_sigframe(), because it can rely on the signal restore
      >     side to restore the original FPU state.
      >
      >   - reading FPU registers on modern systems: we don't do this anywhere at the
      >     moment, mostly to keep symmetry with older systems where FSAVE is
      >     destructive.
      >
      >   - initializing FPU registers on modern systems: fpu__clear() does this. Here
      >     it's safe because we don't copy from the fpstate.
      >
      >   - directly writing FPU registers from user-space memory (!). We do this in
      >     fpu__restore_sig(), and it's safe because neither context switches nor
      >     irq-handler FPU use can corrupt the source context of the copy (which is
      >     user-space memory).
      >
      > Note that the MPX code's current use of copy_fpregs_to_fpstate() was safe I think,
      > because:
      >
      >  - MPX is predicated on eagerfpu, so the destructive F[N]SAVE instruction won't be
      >    used.
      >
      >  - the code was only reading FPU registers, and was doing it only in places that
      >    guaranteed that an FPU state was already active (i.e. didn't do it in
      >    kthreads)
      Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave@sr71.net>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Suresh Siddha <sbsiddha@gmail.com>
      Cc: bp@alien8.de
      Link: http://lkml.kernel.org/r/20150607183700.AA881696@viggo.jf.intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
      04cd027b
  10. 25 5月, 2015 1 次提交
    • I
      x86/fpu: Move the xstate copying functions into fpu/internal.h · fd169b05
      Ingo Molnar 提交于
      All the other register<-> memory copying functions are defined
      in fpu/internal.h, so move the xstate variants there too.
      
      Beyond being more consistent, this also allows FPU debugging
      checks to be added to them. (Because they can now use the
      macros defined in fpu/internal.h.)
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      fd169b05
  11. 20 5月, 2015 1 次提交
    • I
      x86/fpu/xstate: Use explicit parameter in xstate_fault() · b11ca7fb
      Ingo Molnar 提交于
      While looking at xstate.h it took me some time to realize that
      'xstate_fault' uses 'err' as a silent parameter. This is not
      obvious at the call site, at all.
      
      Make it an explicit macro argument, so that the syntactic
      connection is easier to see. Also explain xstate_fault()
      a bit.
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      b11ca7fb
  12. 19 5月, 2015 19 次提交
    • I
      x86/fpu/xstate: Clean up setup_xstate_comp() call · 5fd402df
      Ingo Molnar 提交于
      So call setup_xstate_comp() from the xstate init code, not
      from the generic fpu__init_system() code.
      
      This allows us to remove the protytype from xstate.h as well.
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      5fd402df
    • I
      x86/fpu: Harmonize FPU register state types · c47ada30
      Ingo Molnar 提交于
      Use these consistent names:
      
          struct fregs_state           # was: i387_fsave_struct
          struct fxregs_state          # was: i387_fxsave_struct
          struct swregs_state          # was: i387_soft_struct
          struct xregs_state           # was: xsave_struct
          union  fpregs_state          # was: thread_xstate
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      c47ada30
    • I
      x86/fpu: Rename all the fpregs, xregs, fxregs and fregs handling functions · c6813144
      Ingo Molnar 提交于
      Standardize the naming of the various functions that copy register
      content in specific FPU context formats:
      
        copy_fxregs_to_kernel()         # was: fpu_fxsave()
        copy_xregs_to_kernel()          # was: xsave_state()
      
        copy_kernel_to_fregs()          # was: frstor_checking()
        copy_kernel_to_fxregs()         # was: fxrstor_checking()
        copy_kernel_to_xregs()          # was: fpu_xrstor_checking()
        copy_kernel_to_xregs_booting()  # was: xrstor_state_booting()
      
        copy_fregs_to_user()            # was: fsave_user()
        copy_fxregs_to_user()           # was: fxsave_user()
        copy_xregs_to_user()            # was: xsave_user()
      
        copy_user_to_fregs()            # was: frstor_user()
        copy_user_to_fxregs()           # was: fxrstor_user()
        copy_user_to_xregs()            # was: xrestore_user()
        copy_user_to_fpregs_zeroing()   # was: restore_user_xstate()
      
      Eliminate fpu_xrstor_checking(), because it was just a wrapper.
      
      No change in functionality.
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      c6813144
    • I
      x86/fpu: Generalize 'init_xstate_ctx' · 6f575023
      Ingo Molnar 提交于
      So the handling of init_xstate_ctx has a layering violation: both
      'struct xsave_struct' and 'union thread_xstate' have a
      'struct i387_fxsave_struct' member:
      
         xsave_struct::i387
         thread_xstate::fxsave
      
      The handling of init_xstate_ctx is generic, it is used on all
      CPUs, with or without XSAVE instruction. So it's confusing how
      the generic code passes around and handles an XSAVE specific
      format.
      
      What we really want is for init_xstate_ctx to be a proper
      fpstate and we use its ::fxsave and ::xsave members, as
      appropriate.
      
      Since the xsave_struct::i387 and thread_xstate::fxsave aliases
      each other this is not a functional problem.
      
      So implement this, and move init_xstate_ctx to the generic FPU
      code in the process.
      
      Also, since init_xstate_ctx is not XSAVE specific anymore,
      rename it to init_fpstate, and mark it __read_mostly,
      because it's only modified once during bootup, and used
      as a reference fpstate later on.
      
      There's no change in functionality.
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      6f575023
    • I
      x86/fpu: Factor out fpu/regset.h from fpu/internal.h · 59a36d16
      Ingo Molnar 提交于
      Only a few places use the regset definitions, so factor them out.
      
      Also fix related header dependency assumptions.
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      59a36d16
    • I
      x86/alternatives, x86/fpu: Add 'alternatives_patched' debug flag and use it in xsave_state() · 5e907bb0
      Ingo Molnar 提交于
      We'd like to use xsave_state() earlier, but its SYSTEM_BOOTING check
      is too imprecise.
      
      The real condition that xsave_state() would like to check is whether
      alternative XSAVE instructions were patched into the kernel image
      already.
      
      Add such a (read-mostly) debug flag and use it in xsave_state().
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      5e907bb0
    • I
      x86/fpu: Move xfeature type enumeration to fpu/types.h · 91969d69
      Ingo Molnar 提交于
      So xsave.h is an internal header that FPU using drivers commonly include,
      to get access to the xstate feature names, amongst other things.
      
      Move these type definitions to fpu/fpu.h to allow simplification
      of FPU using driver code.
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      91969d69
    • I
      x86/fpu: Enumerate xfeature bits · 677b98bd
      Ingo Molnar 提交于
      Transform the xstate masks into an enumerated list of xfeature bits.
      
      This removes the hard coding of XFEATURES_NR_MAX.
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      677b98bd
    • I
      x86/fpu: Rename fpu/xsave.h to fpu/xstate.h · 669ebabb
      Ingo Molnar 提交于
      'xsave' is an x86 instruction name to most people - but xsave.h is
      about a lot more than just the XSAVE instruction: it includes
      definitions and support, both internal and external, related to
      xstate and xfeatures support.
      
      As a first step in cleaning up the various xstate uses rename this
      header to 'fpu/xstate.h' to better reflect what this header file
      is about.
      
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      669ebabb
    • I
      x86/fpu: Simplify __save_fpu() · 72ee6f87
      Ingo Molnar 提交于
      __save_fpu() has this pattern:
      
      		if (unlikely(system_state == SYSTEM_BOOTING))
      			xsave_state_booting(&fpu->state.xsave);
      		else
      			xsave_state(&fpu->state.xsave);
      
      ... but it does not actually get called during system bootup.
      
      So remove the complication and always call xsave_state().
      
      To make sure this assumption is correct, add a WARN_ONCE()
      debug check to xsave_state().
      Reviewed-by: NBorislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      72ee6f87
    • I
      x86/fpu: Remove xsave_init() · c42103b2
      Ingo Molnar 提交于
      Expand fpu__init_system_xstate() and fpu__init_cpu_xstate() calls
      into xsave_init() calls.
      
      (This will allow us to call the proper versions in higher level FPU init code
      later on.)
      
      No change in functionality.
      Reviewed-by: NBorislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      c42103b2
    • I
      x86/fpu: Remove 'init_xstate_buf' bootmem allocation · 3e5e1267
      Ingo Molnar 提交于
      Make init_xstate_buf allocated statically at build time.
      
      This structure's maximum size is around 1KB - and it's allocated even on
      most modern embedded x86 CPUs which strive for FPU instruction set parity
      with desktop and server CPUs, so it's not like we can save much on smaller
      systems.
      
      This removes the last bootmem allocation from the FPU init path, allowing
      it to be called earlier in the boot sequence.
      Reviewed-by: NBorislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      3e5e1267
    • I
      x86/fpu: Remove xsave_init() bootmem allocations · 966ece61
      Ingo Molnar 提交于
      There's only 8 xstate bits at the moment, and it's not like we
      can support unknown bits - so put xstate_offsets[] and
      xstate_sizes[] into static allocation.
      
      This is in preparation to be able to call the FPU init code
      earlier, when there's no bootmem available yet.
      Reviewed-by: NBorislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      966ece61
    • I
      x86/fpu: Rename 'xsave_hdr' to 'header' · 3a54450b
      Ingo Molnar 提交于
      Code like:
      
                 fpu->state->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;
      
      is an eyesore, because not only is the words 'xsave' and 'state'
      are repeated twice times (!), but also because of the 'hdr' and 'bv'
      abbreviations that are pretty meaningless at a first glance.
      
      Start cleaning this up by renaming 'xsave_hdr' to 'header'.
      Reviewed-by: NBorislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      3a54450b
    • I
      x86/fpu: Rename 'pcntxt_mask' to 'xfeatures_mask' · 614df7fb
      Ingo Molnar 提交于
      So the 'pcntxt_mask' is a misnomer, it's essentially meaningless to anyone
      who doesn't know what it does exactly.
      
      Name it more descriptively as 'xfeatures_mask'.
      Reviewed-by: NBorislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      614df7fb
    • I
      x86/fpu: Move xsave.h to fpu/xsave.h · a137fb6b
      Ingo Molnar 提交于
      Move the xsave.h header file to the FPU directory as well.
      Reviewed-by: NBorislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      a137fb6b
    • I
      x86/fpu: Remove fpu_xsave() · 0afc4a94
      Ingo Molnar 提交于
      It's a pointless wrapper now - use xsave_state().
      Reviewed-by: NBorislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      0afc4a94
    • I
      x86/fpu: Simplify the xsave_state*() methods · 3e261c14
      Ingo Molnar 提交于
      These functions (xsave_state() and xsave_state_booting()) have a 'mask'
      argument that is always -1.
      
      Propagate this into the functions instead and eliminate the extra argument.
      
      Does not change the generated code, because these were inlined functions.
      Reviewed-by: NBorislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      3e261c14
    • I
      x86/fpu: Remove stale init_fpu() prototype · 68ad8b9f
      Ingo Molnar 提交于
      We are going to split init_fpu() so keep only a single prototype, in i387.h.
      Reviewed-by: NBorislav Petkov <bp@alien8.de>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      68ad8b9f
  13. 06 3月, 2015 1 次提交
    • Q
      x86/fpu/xsaves: Fix improper uses of __ex_table · 06c8173e
      Quentin Casasnovas 提交于
      Commit:
      
        f31a9f7c ("x86/xsaves: Use xsaves/xrstors to save and restore xsave area")
      
      introduced alternative instructions for XSAVES/XRSTORS and commit:
      
        adb9d526 ("x86/xsaves: Add xsaves and xrstors support for booting time")
      
      added support for the XSAVES/XRSTORS instructions at boot time.
      
      Unfortunately both failed to properly protect them against faulting:
      
      The 'xstate_fault' macro will use the closest label named '1'
      backward and that ends up in the .altinstr_replacement section
      rather than in .text. This means that the kernel will never find
      in the __ex_table the .text address where this instruction might
      fault, leading to serious problems if userspace manages to
      trigger the fault.
      Signed-off-by: NQuentin Casasnovas <quentin.casasnovas@oracle.com>
      Signed-off-by: NJamie Iles <jamie.iles@oracle.com>
      [ Improved the changelog, fixed some whitespace noise. ]
      Acked-by: NBorislav Petkov <bp@alien8.de>
      Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
      Cc: <stable@vger.kernel.org>
      Cc: Allan Xavier <mr.a.xavier@gmail.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Fixes: adb9d526 ("x86/xsaves: Add xsaves and xrstors support for booting time")
      Fixes: f31a9f7c ("x86/xsaves: Use xsaves/xrstors to save and restore xsave area")
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      06c8173e
  14. 03 11月, 2014 1 次提交
  15. 19 6月, 2014 1 次提交
  16. 30 5月, 2014 4 次提交