aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorXiaotian Feng <dfeng@redhat.com>2010-08-13 15:19:11 +0800
committerAvi Kivity <avi@redhat.com>2010-08-15 14:10:15 +0300
commitf45755b8346f1a089ca7957dce5f4c3c6cb26e6f (patch)
treef0b34312371aeaf88fed462857af0630a2c19af8
parent3cfc2c42c1cbc8e238bb9c0612c0df4565e3a8b4 (diff)
downloadmrst-s0i3-test-f45755b8346f1a089ca7957dce5f4c3c6cb26e6f.tar.gz
mrst-s0i3-test-f45755b8346f1a089ca7957dce5f4c3c6cb26e6f.tar.xz
mrst-s0i3-test-f45755b8346f1a089ca7957dce5f4c3c6cb26e6f.zip
KVM: fix poison overwritten caused by using wrong xstate size
fpu.state is allocated from task_xstate_cachep, the size of task_xstate_cachep is xstate_size. xstate_size is set from cpuid instruction, which is often smaller than sizeof(struct xsave_struct). kvm is using sizeof(struct xsave_struct) to fill in/out fpu.state.xsave, as what we allocated for fpu.state is xstate_size, kernel will write out of memory and caused poison/redzone/padding overwritten warnings. Signed-off-by: Xiaotian Feng <dfeng@redhat.com> Reviewed-by: Sheng Yang <sheng@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Avi Kivity <avi@redhat.com> Cc: Robert Richter <robert.richter@amd.com> Cc: Sheng Yang <sheng@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Jan Kiszka <jan.kiszka@siemens.com> Signed-off-by: Avi Kivity <avi@redhat.com>
-rw-r--r--arch/x86/kernel/i387.c1
-rw-r--r--arch/x86/kvm/x86.c4
2 files changed, 3 insertions, 2 deletions
diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c
index c4444bce846..f855658d278 100644
--- a/arch/x86/kernel/i387.c
+++ b/arch/x86/kernel/i387.c
@@ -40,6 +40,7 @@
static unsigned int mxcsr_feature_mask __read_mostly = 0xffffffffu;
unsigned int xstate_size;
+EXPORT_SYMBOL_GPL(xstate_size);
unsigned int sig_xstate_ia32_size = sizeof(struct _fpstate_ia32);
static struct i387_fxsave_struct fx_scratch __cpuinitdata;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 97aab036dab..bb2347a69c0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2387,7 +2387,7 @@ static void kvm_vcpu_ioctl_x86_get_xsave(struct kvm_vcpu *vcpu,
if (cpu_has_xsave)
memcpy(guest_xsave->region,
&vcpu->arch.guest_fpu.state->xsave,
- sizeof(struct xsave_struct));
+ xstate_size);
else {
memcpy(guest_xsave->region,
&vcpu->arch.guest_fpu.state->fxsave,
@@ -2405,7 +2405,7 @@ static int kvm_vcpu_ioctl_x86_set_xsave(struct kvm_vcpu *vcpu,
if (cpu_has_xsave)
memcpy(&vcpu->arch.guest_fpu.state->xsave,
- guest_xsave->region, sizeof(struct xsave_struct));
+ guest_xsave->region, xstate_size);
else {
if (xstate_bv & ~XSTATE_FPSSE)
return -EINVAL;