linux.git/arch/x86/kernel/fpu, branch v4.11

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:36+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:35+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-02-20T23:03:51+00:00

Pull x86 fpu updates from Ingo Molnar:
 "The main changes relate to fixes between (lack of) CPUID and FPU
  detection that should only affect old or weird CPUs, by Andy
  Lutomirski"

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Fix the "Giving up, no FPU found" test
  x86/fpu: Fix CPUID-less FPU detection
  x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message
  x86/cpu: Re-apply forced caps every time CPU caps are re-read
  x86/cpu: Factor out application of forced CPU caps
  x86/cpu: Add X86_FEATURE_CPUID
  x86/fpu/xstate: Move XSAVES state init to a function

Merge branch 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2017-02-20T22:37:08+00:00

Pull x86 cpufeature updates from Ingo Molnar:
 "The main changes in this cycle were related to enable ring-3
  MONITOR/MWAIT instructions support on supported CPUs, by Grzegorz
  Andrejczuk and Piotr Luc"

* 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpufeature: Move RING3MWAIT feature to avoid conflicts
  x86/cpufeature: Enable RING3MWAIT for Knights Mill
  x86/cpufeature: Enable RING3MWAIT for Knights Landing
  x86/cpufeature: Add RING3MWAIT to CPU features
  x86/elf: Add HWCAP2 to expose ring 3 MONITOR/MWAIT
  x86/msr: Add MSR_MISC_FEATURE_ENABLES and RING3MWAIT bit
  x86/cpufeature: Add AVX512_VPOPCNTDQ feature

x86/fpu: Fix the "Giving up, no FPU found" test

2017-01-25T09:12:44+00:00

We would never print "Giving up, no FPU found" because
X86_FEATURE_FPU was in REQUIRED_MASK on non-FPU-emulating builds, so
the boot_cpu_has() test didn't do anything.

Signed-off-by: Andy Lutomirski 
Reviewed-by: Borislav Petkov 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Matthew Whitehead 
Cc: Oleg Nesterov 
Cc: One Thousand Gnomes 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Thomas Gleixner 
Cc: Yu-cheng Yu 
Link: http://lkml.kernel.org/r/1499077fa76f0f84b8ea28e37d3fa70beca4e310.1484705016.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/fpu: Fix CPUID-less FPU detection

2017-01-25T09:12:43+00:00

The old code didn't work at all because it adjusted the current caps
instead of the forced caps.  Anything it did would be undone later
during CPU identification.  Fix that and, while we're at it, improve
the logging and don't bother running it if CPUID is available.

Reported-by: Matthew Whitehead 
Signed-off-by: Andy Lutomirski 
Reviewed-by: Borislav Petkov 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: One Thousand Gnomes 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Thomas Gleixner 
Cc: Yu-cheng Yu 
Link: http://lkml.kernel.org/r/f1134e30cafa73c4e2e68119e9741793622cfd15.1484705016.git.luto@kernel.org
Signed-off-by: Ingo Molnar

x86/fpu: Fix "x86/fpu: Legacy x87 FPU detected" message

2017-01-25T09:12:42+00:00

That message isn't at all clear -- what does "Legacy x87" even mean?

Clarify it.  If there's no FPU, say:

  x86/fpu: No FPU detected

If there's an FPU that doesn't have XSAVE, say:

  x86/fpu: x87 FPU will use FSAVE|FXSAVE

Signed-off-by: Andy Lutomirski 
Reviewed-by: Borislav Petkov 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Matthew Whitehead 
Cc: Oleg Nesterov 
Cc: One Thousand Gnomes 
Cc: Peter Zijlstra 
Cc: Rik van Riel 
Cc: Thomas Gleixner 
Cc: Yu-cheng Yu 
Link: http://lkml.kernel.org/r/bb839385e18e27bca23fe8666dfdad8170473045.1484705016.git.luto@kernel.org
[ Small tweaks to the messages. ]
Signed-off-by: Ingo Molnar

x86/fpu/xstate: Move XSAVES state init to a function

2017-01-25T07:25:12+00:00

Make XSTATE init similar to existing code; move it to a separate function.
There is no functionality change.

Signed-off-by: Yu-cheng Yu 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Ravi V. Shankar 
Cc: Rik van Riel 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/1485282346-15437-1-git-send-email-yu-cheng.yu@intel.com
[ Minor cleanliness edits. ]
Signed-off-by: Ingo Molnar

x86/fpu/xstate: Fix xcomp_bv in XSAVES header

2017-01-24T08:04:48+00:00

The compacted-format XSAVES area is determined at boot time and
never changed after.  The field xsave.header.xcomp_bv indicates
which components are in the fixed XSAVES format.

In fpstate_init() we did not set xcomp_bv to reflect the XSAVES
format since at the time there is no valid data.

However, after we do copy_init_fpstate_to_fpregs() in fpu__clear(),
as in commit:

  b22cbe404a9c x86/fpu: Fix invalid FPU ptrace state after execve()

and when __fpu_restore_sig() does fpu__restore() for a COMPAT-mode
app, a #GP occurs.  This can be easily triggered by doing valgrind on
a COMPAT-mode "Hello World," as reported by Joakim Tjernlund and
others:

	https://bugzilla.kernel.org/show_bug.cgi?id=190061

Fix it by setting xcomp_bv correctly.

This patch also moves the xcomp_bv initialization to the proper
place, which was in copyin_to_xsaves() as of:

  4c833368f0bf x86/fpu: Set the xcomp_bv when we fake up a XSAVES area

which fixed the bug too, but it's more efficient and cleaner to
initialize things once per boot, not for every signal handling
operation.

Reported-by: Kevin Hao 
Reported-by: Joakim Tjernlund 
Signed-off-by: Yu-cheng Yu 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Fenghua Yu 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Ravi V. Shankar 
Cc: Thomas Gleixner 
Cc: haokexin@gmail.com
Link: http://lkml.kernel.org/r/1485212084-4418-1-git-send-email-yu-cheng.yu@intel.com
[ Combined it with 4c833368f0bf. ]
Signed-off-by: Ingo Molnar

x86/fpu: Set the xcomp_bv when we fake up a XSAVES area

2017-01-23T09:40:18+00:00

I got the following calltrace on a Apollo Lake SoC with 32-bit kernel:

  WARNING: CPU: 2 PID: 261 at arch/x86/include/asm/fpu/internal.h:363 fpu__restore+0x1f5/0x260
  [...]
  Hardware name: Intel Corp. Broxton P/NOTEBOOK, BIOS APLIRVPA.X64.0138.B35.1608091058 08/09/2016
  Call Trace:
   dump_stack()
   __warn()
   ? fpu__restore()
   warn_slowpath_null()
   fpu__restore()
   __fpu__restore_sig()
   fpu__restore_sig()
   restore_sigcontext.isra.9()
   sys_sigreturn()
   do_int80_syscall_32()
   entry_INT80_32()

The reason is that a #GP occurs when executing XRSTORS. The root cause
is that we forget to set the xcomp_bv when we fake up the XSAVES area
in the copyin_to_xsaves() function.

Signed-off-by: Kevin Hao 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Dave Hansen 
Cc: Denys Vlasenko 
Cc: Fenghua Yu 
Cc: H. Peter Anvin 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Oleg Nesterov 
Cc: Peter Zijlstra 
Cc: Quentin Casasnovas 
Cc: Rik van Riel 
Cc: Thomas Gleixner 
Cc: Yu-cheng Yu 
Link: http://lkml.kernel.org/r/1485075023-30161-1-git-send-email-haokexin@gmail.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner