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>
This commit is contained in:
Robert Richter 2010-07-21 19:03:57 +02:00 committed by H. Peter Anvin
parent ad41a1e0ca
commit 1f999ab5a1

View File

@ -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;
} }