Messages in this thread Patch in this message | | | Date | Tue, 2 Sep 2014 15:18:47 -0700 | From | tip-bot for Oleg Nesterov <> | Subject | [tip:x86/fpu] x86, fpu: __restore_xstate_sig()-> math_state_restore() needs preempt_disable() |
| |
Commit-ID: df24fb859a4e200d9324e2974229fbb7adf00aef Gitweb: http://git.kernel.org/tip/df24fb859a4e200d9324e2974229fbb7adf00aef Author: Oleg Nesterov <oleg@redhat.com> AuthorDate: Tue, 2 Sep 2014 19:57:17 +0200 Committer: H. Peter Anvin <hpa@linux.intel.com> CommitDate: Tue, 2 Sep 2014 14:51:15 -0700
x86, fpu: __restore_xstate_sig()->math_state_restore() needs preempt_disable()
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 Cc: <stable@vger.kernel.org> # v3.7+ Reviewed-by: Suresh Siddha <sbsiddha@gmail.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> --- arch/x86/kernel/xsave.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index cf0b830..4c540c4 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -400,8 +400,11 @@ int __restore_xstate_sig(void __user *buf, void __user *buf_fx, int size) set_used_math(); } - if (use_eager_fpu()) + if (use_eager_fpu()) { + preempt_disable(); math_state_restore(); + preempt_enable(); + } return err; } else {
| |