---

yaml
---
r: 299873
b: refs/heads/master
c: ff9a184
h: refs/heads/master
i:
  299871: 283fc4a
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2498814fcb3068f19b82b1519b4038721f61af43
+refs/heads/master: ff9a184cfb6542bef98aff1789481284e122a4b3

trunk/arch/arm/vfp/vfpmodule.c

@@ -564,6 +564,21 @@ int vfp_preserve_user_clear_hwstate(struct user_vfp __user *ufp,
 
 	if (err)
 		return -EFAULT;
+
+	/* Ensure that VFP is disabled. */
+	vfp_flush_hwstate(thread);
+
+	/*
+	 * As per the PCS, clear the length and stride bits for function
+	 * entry.
+	 */
+	hwstate->fpscr &= ~(FPSCR_LENGTH_MASK | FPSCR_STRIDE_MASK);
+
+	/*
+	 * Disable VFP in the hwstate so that we can detect if it gets
+	 * used.
+	 */
+	hwstate->fpexc &= ~FPEXC_EN;
 	return 0;
 }
 
@@ -576,7 +591,12 @@ int vfp_restore_user_hwstate(struct user_vfp __user *ufp,
 	unsigned long fpexc;
 	int err = 0;
 
-	vfp_flush_hwstate(thread);
+	/*
+	 * If VFP has been used, then disable it to avoid corrupting
+	 * the new thread state.
+	 */
+	if (hwstate->fpexc & FPEXC_EN)
+		vfp_flush_hwstate(thread);
 
 	/*
 	 * Copy the floating point registers. There can be unused