KVM: fix poison overwritten caused by using wrong xstate size
authorXiaotian Feng <dfeng@redhat.com>
Fri, 13 Aug 2010 07:19:11 +0000 (15:19 +0800)
committerAvi Kivity <avi@redhat.com>
Sun, 15 Aug 2010 11:10:15 +0000 (14:10 +0300)
commitf45755b8346f1a089ca7957dce5f4c3c6cb26e6f
treef0b34312371aeaf88fed462857af0630a2c19af8
parent3cfc2c42c1cbc8e238bb9c0612c0df4565e3a8b4
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>
arch/x86/kernel/i387.c
arch/x86/kvm/x86.c