Commit 1f999ab5 authored Jul 21, 2010 by Robert Richter Committed by H. Peter Anvin Aug 12, 2010

x86, xsave: Disable xsave in i387 emulation mode



xsave is broken for (!HAVE_HWFP). This is the case if config
MATH_EMULATION is enabled, 'no387' kernel parameter is set and xsave
exists. xsave will not work because x86/math-emu and xsave share the
same memory. As this case can be treated as corner case we simply
disable xsave then.

Signed-off-by: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1279731838-1522-7-git-send-email-robert.richter@amd.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

parent ad41a1e0

arch/x86/kernel/i387.c

+6 −0

Original line number	Original line	Diff line number	Diff line
	@@ -67,6 +67,12 @@ static void __cpuinit init_thread_xstate(void)
	*/		*/

	if (!HAVE_HWFP) {		if (!HAVE_HWFP) {
			/*
			* Disable xsave as we do not support it if i387
			* emulation is enabled.
			*/
			setup_clear_cpu_cap(X86_FEATURE_XSAVE);
			setup_clear_cpu_cap(X86_FEATURE_XSAVEOPT);
	xstate_size = sizeof(struct i387_soft_struct);		xstate_size = sizeof(struct i387_soft_struct);
	return;		return;
	}		}