[PATCH 04/11] x86/entry: move PUSH_AND_CLEAR_REGS out of error_entry

[Lai Jiangshan <jiangshanlai@xxxxxxxxx>]

From: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>

Moving PUSH_AND_CLEAR_REGS out of error_entry doesn't change any
functionality.  It will enlarge the size:

size arch/x86/entry/entry_64.o.before:
   text    data     bss     dec     hex filename
  17916     384       0   18300    477c arch/x86/entry/entry_64.o

size --format=SysV arch/x86/entry/entry_64.o.before:
.entry.text                      5528      0
.orc_unwind                      6456      0
.orc_unwind_ip                   4304      0

size arch/x86/entry/entry_64.o.after:
   text    data     bss     dec     hex filename
  26868     384       0   27252    6a74 arch/x86/entry/entry_64.o

size --format=SysV arch/x86/entry/entry_64.o.after:
.entry.text                      8200      0
.orc_unwind                     10224      0
.orc_unwind_ip                   6816      0

But .entry.text in x86_64 is 2M aligned, enlarging it to 8.2k doesn't
enlarge the final text size.

The tables .orc_unwind[_ip] are enlarged due to it adds many pushes.

It is prepared for not calling error_entry() from XENPV in later patch
and for future converting the whole error_entry into C code.

Signed-off-by: Lai Jiangshan <laijs@xxxxxxxxxxxxxxxxx>
---
 arch/x86/entry/entry_64.S | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 6baa7413f7eb..72ceb4b70822 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -322,6 +322,9 @@ SYM_CODE_END(ret_from_fork)
  */
 .macro idtentry_body cfunc has_error_code:req
 
+       PUSH_AND_CLEAR_REGS
+       ENCODE_FRAME_POINTER
+
        call    error_entry
        movq    %rax, %rsp                      /* switch stack settled by 
sync_regs() */
        ENCODE_FRAME_POINTER
@@ -969,8 +972,6 @@ SYM_CODE_END(paranoid_exit)
 SYM_CODE_START_LOCAL(error_entry)
        UNWIND_HINT_FUNC
        cld
-       PUSH_AND_CLEAR_REGS save_ret=1
-       ENCODE_FRAME_POINTER 8
        testb   $3, CS+8(%rsp)
        jz      .Lerror_kernelspace
 
-- 
2.19.1.6.gb485710b