From 377ffbcc536a5a6666dc077395163ab149c02610 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Fri, 24 Aug 2012 14:12:58 -0700 Subject: [PATCH] x86, fpu: remove unnecessary user_fpu_end() in save_xstate_sig() Few lines below we do drop_fpu() which is more safer. Remove the unnecessary user_fpu_end() in save_xstate_sig(), which allows the drop_fpu() to ignore any pending exceptions from the user-space and drop the current fpu. Signed-off-by: Suresh Siddha Link: http://lkml.kernel.org/r/1345842782-24175-3-git-send-email-suresh.b.siddha@intel.com Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/fpu-internal.h | 17 +++-------------- arch/x86/kernel/xsave.c | 1 - 2 files changed, 3 insertions(+), 15 deletions(-) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 78169d1..52202a6 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -412,22 +412,11 @@ static inline void __drop_fpu(struct task_struct *tsk) } /* - * The actual user_fpu_begin/end() functions - * need to be preemption-safe. + * Need to be preemption-safe. * - * NOTE! user_fpu_end() must be used only after you - * have saved the FP state, and user_fpu_begin() must - * be used only immediately before restoring it. - * These functions do not do any save/restore on - * their own. + * NOTE! user_fpu_begin() must be used only immediately before restoring + * it. This function does not do any save/restore on their own. */ -static inline void user_fpu_end(void) -{ - preempt_disable(); - __thread_fpu_end(current); - preempt_enable(); -} - static inline void user_fpu_begin(void) { preempt_disable(); diff --git a/arch/x86/kernel/xsave.c b/arch/x86/kernel/xsave.c index 07ddc87..4ac5f2e 100644 --- a/arch/x86/kernel/xsave.c +++ b/arch/x86/kernel/xsave.c @@ -255,7 +255,6 @@ int save_xstate_sig(void __user *buf, void __user *buf_fx, int size) /* Update the thread's fxstate to save the fsave header. */ if (ia32_fxstate) fpu_fxsave(&tsk->thread.fpu); - user_fpu_end(); } else { sanitize_i387_state(tsk); if (__copy_to_user(buf_fx, xsave, xstate_size)) -- 2.7.4