x86, fpu: __restore_xstate_sig()->math_state_restore() needs preempt_disable()
authorOleg Nesterov <oleg@redhat.com>
Tue, 2 Sep 2014 17:57:17 +0000 (19:57 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 14 Nov 2014 16:47:54 +0000 (08:47 -0800)
commitb888e3d442069e3107d9b4a43c1321e4d555b6cd
treebfbba55a4bc78ff064e34efb811b4825d8d7e7d1
parent6507b92a66c9551b0555edc5a92e27027c3b990e
x86, fpu: __restore_xstate_sig()->math_state_restore() needs preempt_disable()

commit df24fb859a4e200d9324e2974229fbb7adf00aef upstream.

Add preempt_disable() + preempt_enable() around math_state_restore() in
__restore_xstate_sig(). Otherwise __switch_to() after __thread_fpu_begin()
can overwrite fpu->state we are going to restore.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20140902175717.GA21649@redhat.com
Reviewed-by: Suresh Siddha <sbsiddha@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arch/x86/kernel/xsave.c