From mboxrd@z Thu Jan  1 00:00:00 1970
From: Paul Gortmaker <paul.gortmaker@windriver.com>
Subject: [stable-3.4] possibly revert "KVM: X86 emulator: fix source operand
 decoding..."
Date: Wed, 4 Sep 2013 12:44:15 -0400
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Hi Greg,

The 3.4.44+ cherry pick:

  ----------------
  commit 5b5b30580218eae22609989546bac6e44d0eda6e
  Author: Gleb Natapov <gleb@redhat.com>
  Date:   Wed Apr 24 13:38:36 2013 +0300

    KVM: X86 emulator: fix source operand decoding for 8bit mov[zs]x in=
structions
   =20
    commit 660696d1d16a71e15549ce1bf74953be1592bcd3 upstream.
   =20
    Source operand for one byte mov[zs]x is decoded incorrectly if it i=
s in
    high byte register. Fix that.
   =20
    Signed-off-by: Gleb Natapov <gleb@redhat.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  ----------------

introduces the following:

arch/x86/kvm/emulate.c: In function =E2=80=98decode_operand=E2=80=99:
arch/x86/kvm/emulate.c:3974:4: warning: passing argument 1 of =E2=80=98=
decode_register=E2=80=99 makes integer from pointer without a cast [ena=
bled by default]
arch/x86/kvm/emulate.c:789:14: note: expected =E2=80=98u8=E2=80=99 but =
argument is of type =E2=80=98struct x86_emulate_ctxt *=E2=80=99
arch/x86/kvm/emulate.c:3974:4: warning: passing argument 2 of =E2=80=98=
decode_register=E2=80=99 makes pointer from integer without a cast [ena=
bled by default]
arch/x86/kvm/emulate.c:789:14: note: expected =E2=80=98long unsigned in=
t *=E2=80=99 but argument is of type =E2=80=98u8=E2=80=99

Based on the severity of the warnings above, I'm reasonably sure there =
will
be some kind of runtime regressions due to this, but I stopped to inves=
tigate
the warnings as soon as I saw them, before any run time testing.

It happens because mainline v3.7-rc1~113^2~40 (dd856efafe60) does this:

-static void *decode_register(u8 modrm_reg, unsigned long *regs,
+static void *decode_register(struct x86_emulate_ctxt *ctxt, u8 modrm_r=
eg,

Since 660696d1d16a71e1 was only applied to stable 3.4, 3.8, and 3.9 -- =
and
the prerequisite above is in 3.7+, the issue should be limited to 3.4.4=
4+

Thanks,
Paul.