[Xen-changelog] [xen master] x86emul: make _PRE_EFLAGS() tolerate first argument being 32-bit

[patchbot@xxxxxxx]

commit e510059a8bfc564407ed044639e607c8f5ab0d6f
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Jan 4 14:28:02 2017 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Jan 4 14:28:02 2017 +0100

    x86emul: make _PRE_EFLAGS() tolerate first argument being 32-bit
    
    While this may appear to introduce a truncation issue, the high 32 bits
    get zapped already anyway (early in _PRE_EFLAGS() as well as in
    _POST_EFLAGS()). Once a subsequent patch switches to use proper 32-bit
    EFLAGS operands, we'll in fact end up with more correct code, as that
    zeroing of the upper halves will then go away.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/x86_emulate/x86_emulate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/x86_emulate/x86_emulate.c 
b/xen/arch/x86/x86_emulate/x86_emulate.c
index 29e1f46..e200e61 100644
--- a/xen/arch/x86/x86_emulate/x86_emulate.c
+++ b/xen/arch/x86/x86_emulate/x86_emulate.c
@@ -530,7 +530,8 @@ typedef union {
 "pop  %"_tmp"; "                                                \
 "orl  %"_LO32 _tmp",("_STK"); "                                 \
 "popf; "                                                        \
-"pop  %"_sav"; "
+"pop  %"_tmp"; "                                                \
+"movl %"_LO32 _tmp",%"_LO32 _sav"; "
 
 /* After executing instruction: write-back necessary bits in EFLAGS. */
 #define _POST_EFLAGS(_sav, _msk, _tmp)          \
--
generated by git-patchbot for /home/xen/git/xen.git#master

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