x86, fpu: drop_fpu() before restoring new state from sigframe
No need to save the state with unlazy_fpu(), that is about to get overwritten
by the state from the signal frame. Instead use drop_fpu() and continue
to restore the new state.
Also fold the stop_fpu_preload() into drop_fpu().
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Link: http://lkml.kernel.org/r/1345842782-24175-2-git-send-email-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 0923d27..07ddc87 100644
--- a/arch/x86/kernel/xsave.c
+++ b/arch/x86/kernel/xsave.c
@@ -382,16 +382,14 @@
struct xsave_struct *xsave = &tsk->thread.fpu.state->xsave;
struct user_i387_ia32_struct env;
- stop_fpu_preload(tsk);
- unlazy_fpu(tsk);
+ drop_fpu(tsk);
if (__copy_from_user(xsave, buf_fx, state_size) ||
- __copy_from_user(&env, buf, sizeof(env))) {
- drop_fpu(tsk);
+ __copy_from_user(&env, buf, sizeof(env)))
return -1;
- }
sanitize_restored_xstate(tsk, &env, xstate_bv, fx_only);
+ set_used_math();
} else {
/*
* For 64-bit frames and 32-bit fsave frames, restore the user