Change in coreboot[master]: cpu/x86: Align stack in SIPI handler

[Marshall Dawson (Code Review)]

Marshall Dawson has uploaded this change for review. ( https://review.coreboot.org/21768

Change subject: cpu/x86: Align stack in SIPI handler
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cpu/x86: Align stack in SIPI handler

Ensure the stack is properly aligned in the SIPI handler.

BUG=b:66003093
TEST=boot kahlee built with gcc 6.3

Change-Id: Ibdd8242494c6a2bc0c6ead7ac98be55149219d7c
Signed-off-by: Marshall Dawson 
---
M src/cpu/x86/sipi_vector.S
1 file changed, 4 insertions(+), 1 deletion(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/68/21768/1

diff --git a/src/cpu/x86/sipi_vector.S b/src/cpu/x86/sipi_vector.S
index b40ea76..bd60c65 100644
--- a/src/cpu/x86/sipi_vector.S
+++ b/src/cpu/x86/sipi_vector.S
@@ -114,6 +114,8 @@
    movl	stack_top, %edx
    subl	%eax, %edx
    mov	%edx, %esp
+	andl	$0xfffffff0, %esp /* ensure stack alignment */
+
    /* Save CPU number. */
    mov	%ecx, %esi

@@ -192,7 +194,8 @@
    mov	%eax, %cr4
 #endif

-	/* c_handler(cpu_num) */
+	/* c_handler(cpu_num), preserve proper stack alignment */
+	sub	$12, %esp
    push	%esi	/* cpu_num */
    mov	c_handler, %eax
    call	*%eax