commit 6152e4b1c99a3689fc318d092cd144597f7dbd14
author H. Peter Anvin <hpa@zytor.com> Tue Jul 29 17:23:16 2008 -0700
committer Ingo Molnar <mingo@elte.hu> Wed Jul 30 19:50:35 2008 +0200
tree 8d0590b7ea931da237d037db1bbff5aa0bf1ef34
parent b4a091a62c8e91d6077e575600363cff73fa02ef

x86, xsave: keep the XSAVE feature mask as an u64

The XSAVE feature mask is a 64-bit number; keep it that way, in order
to avoid the mistake done with rdmsr/wrmsr.  Use the xsetbv() function
provided in the previous patch.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/i387.c

diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index e0ed59f..45723f1 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -552,18 +552,17 @@
 		(struct i387_fxsave_struct __user *) &fx_user->_fxsr_env[0];
 	struct xsave_hdr_struct *xsave_hdr =
 				&current->thread.xstate->xsave.xsave_hdr;
-	unsigned int lmask, hmask;
+	u64 mask;
 	int err;
 
 	if (check_for_xstate(fx, buf, &fx_sw_user))
 		goto fx_only;
 
-	lmask = fx_sw_user.xstate_bv;
-	hmask = fx_sw_user.xstate_bv >> 32;
+	mask = fx_sw_user.xstate_bv;
 
 	err = restore_i387_fxsave(buf, fx_sw_user.xstate_size);
 
-	xsave_hdr->xstate_bv &=  (pcntxt_lmask | (((u64) pcntxt_hmask) << 32));
+	xsave_hdr->xstate_bv &= pcntxt_mask;
 	/*
 	 * These bits must be zero.
 	 */
@@ -573,9 +572,8 @@
 	 * Init the state that is not present in the memory layout
 	 * and enabled by the OS.
 	 */
-	lmask = ~(pcntxt_lmask & ~lmask);
-	hmask = ~(pcntxt_hmask & ~hmask);
-	xsave_hdr->xstate_bv &=  (lmask | (((u64) hmask) << 32));
+	mask = ~(pcntxt_mask & ~mask);
+	xsave_hdr->xstate_bv &= mask;
 
 	return err;
 fx_only: