From: Julien Grall <julien.grall@linaro.org>
Date: Thu, 10 Apr 2014 11:43:57 +0000 (+0100)
Subject: xen/arm64: Correctly align VFP regs
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~5206
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=9b4e96724eeb916f2cd311d9133f00c216caa321;p=xen.git

xen/arm64: Correctly align VFP regs

On arm64, VFP instructions requires vfpregs to be 128-byte aligned.

By chance, the field is already correctly aligned. In the case if someone
decides to add a new field before, Xen will receive a data abort as soon as
it saves/restores VFP.

We are safe on arm32 as the only constraint is to be 32-byte aligned.

Reported-by: Chen Baozi <baozich@gmail.com>
Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---

diff --git a/xen/include/asm-arm/arm64/vfp.h b/xen/include/asm-arm/arm64/vfp.h
index 373f156b2e..6ab5d36c6c 100644
--- a/xen/include/asm-arm/arm64/vfp.h
+++ b/xen/include/asm-arm/arm64/vfp.h
@@ -1,9 +1,12 @@
 #ifndef _ARM_ARM64_VFP_H
 #define _ARM_ARM64_VFP_H
 
+/* ARM64 VFP instruction requires fpregs address to be 128-byte aligned */
+#define __vfp_aligned __attribute__((aligned(16)))
+
 struct vfp_state
 {
-    uint64_t fpregs[64];
+    uint64_t fpregs[64] __vfp_aligned;
     uint32_t fpcr;
     uint32_t fpexc32_el2;
     uint32_t fpsr;