linux.git/arch/x86/include/asm, branch v4.20

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

2018-12-21T17:22:24+00:00

Pull x86 fixes from Ingo Molnar:
 "The biggest part is a series of reverts for the macro based GCC
  inlining workarounds. It caused regressions in distro build and other
  kernel tooling environments, and the GCC project was very receptive to
  fixing the underlying inliner weaknesses - so as time ran out we
  decided to do a reasonably straightforward revert of the patches. The
  plan is to rely on the 'asm inline' GCC 9 feature, which might be
  backported to GCC 8 and could thus become reasonably widely available
  on modern distros.

  Other than those reverts, there's misc fixes from all around the
  place.

  I wish our final x86 pull request for v4.20 was smaller..."

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  Revert "kbuild/Makefile: Prepare for using macros in inline assembly code to work around asm() related GCC inlining bugs"
  Revert "x86/objtool: Use asm macros to work around GCC inlining bugs"
  Revert "x86/refcount: Work around GCC inlining bug"
  Revert "x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs"
  Revert "x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs"
  Revert "x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops"
  Revert "x86/extable: Macrofy inline assembly code to work around GCC inlining bugs"
  Revert "x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs"
  Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"
  x86/mtrr: Don't copy uninitialized gentry fields back to userspace
  x86/fsgsbase/64: Fix the base write helper functions
  x86/mm/cpa: Fix cpa_flush_array() TLB invalidation
  x86/vdso: Pass --eh-frame-hdr to the linker
  x86/mm: Fix decoy address handling vs 32-bit builds
  x86/intel_rdt: Ensure a CPU remains online for the region's pseudo-locking sequence
  x86/dump_pagetables: Fix LDT remap address marker
  x86/mm: Fix guard hole handling

Revert "x86/refcount: Work around GCC inlining bug"

2018-12-19T11:00:09+00:00

This reverts commit 9e1725b410594911cc5981b6c7b4cea4ec054ca8.

See this commit for details about the revert:

  e769742d3584 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"")

The conflict resolution for interaction with:

  288e4521f0f6: ("x86/asm: 'Simplify' GEN_*_RMWcc() macros")

was provided by Masahiro Yamada.

 Conflicts:
	arch/x86/include/asm/refcount.h

Reported-by: Masahiro Yamada 
Reviewed-by: Borislav Petkov 
Reviewed-by: Thomas Gleixner 
Cc: Juergen Gross 
Cc: Richard Biener 
Cc: Kees Cook 
Cc: Segher Boessenkool 
Cc: Ard Biesheuvel 
Cc: Peter Zijlstra 
Cc: Josh Poimboeuf 
Cc: Nadav Amit 
Cc: Linus Torvalds 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

Revert "x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs"

2018-12-19T11:00:04+00:00

This reverts commit 77f48ec28e4ccff94d2e5f4260a83ac27a7f3099.

See this commit for details about the revert:

  e769742d3584 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"")

Reported-by: Masahiro Yamada 
Reviewed-by: Borislav Petkov 
Reviewed-by: Thomas Gleixner 
Cc: Juergen Gross 
Cc: Richard Biener 
Cc: Kees Cook 
Cc: Segher Boessenkool 
Cc: Ard Biesheuvel 
Cc: Peter Zijlstra 
Cc: Josh Poimboeuf 
Cc: Nadav Amit 
Cc: Linus Torvalds 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

Revert "x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs"

2018-12-19T11:00:00+00:00

This reverts commit f81f8ad56fd1c7b99b2ed1c314527f7d9ac447c6.

See this commit for details about the revert:

  e769742d3584 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"")

Reported-by: Masahiro Yamada 
Reviewed-by: Borislav Petkov 
Reviewed-by: Thomas Gleixner 
Cc: Juergen Gross 
Cc: Richard Biener 
Cc: Kees Cook 
Cc: Segher Boessenkool 
Cc: Ard Biesheuvel 
Cc: Peter Zijlstra 
Cc: Josh Poimboeuf 
Cc: Nadav Amit 
Cc: Linus Torvalds 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

Revert "x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops"

2018-12-19T10:59:55+00:00

This reverts commit 494b5168f2de009eb80f198f668da374295098dd.

See this commit for details about the revert:

  e769742d3584 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"")

Reported-by: Masahiro Yamada 
Reviewed-by: Borislav Petkov 
Reviewed-by: Thomas Gleixner 
Cc: Juergen Gross 
Cc: Richard Biener 
Cc: Kees Cook 
Cc: Segher Boessenkool 
Cc: Ard Biesheuvel 
Cc: Peter Zijlstra 
Cc: Josh Poimboeuf 
Cc: Nadav Amit 
Cc: Linus Torvalds 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

Revert "x86/extable: Macrofy inline assembly code to work around GCC inlining bugs"

2018-12-19T10:59:47+00:00

This reverts commit 0474d5d9d2f7f3b11262f7bf87d0e7314ead9200.

See this commit for details about the revert:

  e769742d3584 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"")

Reported-by: Masahiro Yamada 
Reviewed-by: Borislav Petkov 
Reviewed-by: Thomas Gleixner 
Cc: Juergen Gross 
Cc: Richard Biener 
Cc: Kees Cook 
Cc: Segher Boessenkool 
Cc: Ard Biesheuvel 
Cc: Peter Zijlstra 
Cc: Josh Poimboeuf 
Cc: Nadav Amit 
Cc: Linus Torvalds 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

Revert "x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs"

2018-12-19T10:59:21+00:00

This reverts commit d5a581d84ae6b8a4a740464b80d8d9cf1e7947b2.

See this commit for details about the revert:

  e769742d3584 ("Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"")

Reported-by: Masahiro Yamada 
Reviewed-by: Borislav Petkov 
Reviewed-by: Thomas Gleixner 
Cc: Juergen Gross 
Cc: Richard Biener 
Cc: Kees Cook 
Cc: Segher Boessenkool 
Cc: Ard Biesheuvel 
Cc: Peter Zijlstra 
Cc: Josh Poimboeuf 
Cc: Nadav Amit 
Cc: Linus Torvalds 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

Revert "x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs"

2018-12-19T10:58:10+00:00

This reverts commit 5bdcd510c2ac9efaf55c4cbd8d46421d8e2320cd.

The macro based workarounds for GCC's inlining bugs caused regressions: distcc
and other distro build setups broke, and the fixes are not easy nor will they
solve regressions on already existing installations.

So we are reverting this patch and the 8 followup patches.

What makes this revert easier is that GCC9 will likely include the new 'asm inline'
syntax that makes inlining of assembly blocks a lot more robust.

This is a superior method to any macro based hackeries - and might even be
backported to GCC8, which would make all modern distros get the inlining
fixes as well.

Many thanks to Masahiro Yamada and others for helping sort out these problems.

Reported-by: Masahiro Yamada 
Reviewed-by: Borislav Petkov 
Reviewed-by: Thomas Gleixner 
Cc: Juergen Gross 
Cc: Richard Biener 
Cc: Kees Cook 
Cc: Segher Boessenkool 
Cc: Ard Biesheuvel 
Cc: Peter Zijlstra 
Cc: Josh Poimboeuf 
Cc: Nadav Amit 
Cc: Linus Torvalds 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

kvm: x86: Add AMD's EX_CFG to the list of ignored MSRs

2018-12-18T21:15:44+00:00

Some guests OSes (including Windows 10) write to MSR 0xc001102c
on some cases (possibly while trying to apply a CPU errata).
Make KVM ignore reads and writes to that MSR, so the guest won't
crash.

The MSR is documented as "Execution Unit Configuration (EX_CFG)",
at AMD's "BIOS and Kernel Developer's Guide (BKDG) for AMD Family
15h Models 00h-0Fh Processors".

Cc: stable@vger.kernel.org
Signed-off-by: Eduardo Habkost 
Signed-off-by: Paolo Bonzini

x86/fsgsbase/64: Fix the base write helper functions

2018-12-18T13:26:09+00:00

Andy spotted a regression in the fs/gs base helpers after the patch series
was committed. The helper functions which write fs/gs base are not just
writing the base, they are also changing the index. That's wrong and needs
to be separated because writing the base has not to modify the index.

While the regression is not causing any harm right now because the only
caller depends on that behaviour, it's a guarantee for subtle breakage down
the road.

Make the index explicitly changed from the caller, instead of including
the code in the helpers.

Subsequently, the task write helpers do not handle for the current task
anymore. The range check for a base value is also factored out, to minimize
code redundancy from the caller.

Fixes: b1378a561fd1 ("x86/fsgsbase/64: Introduce FS/GS base helper functions")
Suggested-by: Andy Lutomirski 
Signed-off-by: Chang S. Bae 
Signed-off-by: Thomas Gleixner 
Reviewed-by: Andy Lutomirski 
Cc: "H . Peter Anvin" 
Cc: Andi Kleen 
Cc: Dave Hansen 
Cc: Ravi Shankar 
Cc: H. Peter Anvin 
Link: https://lkml.kernel.org/r/20181126195524.32179-1-chang.seok.bae@intel.com