x86, xsave: Check cpuid level for XSTATE_CPUID (0x0d)
The patch introduces the XSTATE_CPUID macro and adds a check that
tests if XSTATE_CPUID exists.
Signed-off-by: Robert Richter <robert.richter@amd.com>
LKML-Reference: <1279731838-1522-4-git-send-email-robert.richter@amd.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c
index 2322f58..5adb7fb 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -379,7 +379,7 @@
xstate_sizes = alloc_bootmem(xstate_features * sizeof(int));
do {
- cpuid_count(0xd, leaf, &eax, &ebx, &ecx, &edx);
+ cpuid_count(XSTATE_CPUID, leaf, &eax, &ebx, &ecx, &edx);
if (eax == 0)
break;
@@ -425,7 +425,12 @@
{
unsigned int eax, ebx, ecx, edx;
- cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx);
+ if (boot_cpu_data.cpuid_level < XSTATE_CPUID) {
+ WARN(1, KERN_ERR "XSTATE_CPUID missing\n");
+ return;
+ }
+
+ cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
pcntxt_mask = eax + ((u64)edx << 32);
if ((pcntxt_mask & XSTATE_FPSSE) != XSTATE_FPSSE) {
@@ -444,7 +449,7 @@
/*
* Recompute the context size for enabled features
*/
- cpuid_count(0xd, 0, &eax, &ebx, &ecx, &edx);
+ cpuid_count(XSTATE_CPUID, 0, &eax, &ebx, &ecx, &edx);
xstate_size = ebx;
update_regset_xstate_info(xstate_size, pcntxt_mask);