x86, xsave: reorganization of signal save/restore fpstate code layout

move 64bit routines that saves/restores fpstate in/from user stack from
signal_64.c to xsave.c

restore_i387_xstate() now handles the condition when user passes
NULL fpstate.

Other misc changes for prepartion of xsave/xrstor sigcontext support.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 80 deletions

diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index 0deab8eff33f..ddf6123a55c8 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -54,69 +54,6 @@ sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
 }
 
 /*
- * Signal frame handlers.
- */
-
-static inline int save_i387(struct _fpstate __user *buf)
-{
-        struct task_struct *tsk = current;
-        int err = 0;
-
-        BUILD_BUG_ON(sizeof(struct user_i387_struct) !=
-                        sizeof(tsk->thread.xstate->fxsave));
-
-        if ((unsigned long)buf % 16)
-                printk("save_i387: bad fpstate %p\n", buf);
-
-        if (!used_math())
-                return 0;
-        clear_used_math(); /* trigger finit */
-        if (task_thread_info(tsk)->status & TS_USEDFPU) {
-                err = save_i387_checking((struct i387_fxsave_struct __user *)
-                                         buf);
-                if (err)
-                        return err;
-                task_thread_info(tsk)->status &= ~TS_USEDFPU;
-                stts();
-        } else {
-                if (__copy_to_user(buf, &tsk->thread.xstate->fxsave,
-                                   sizeof(struct i387_fxsave_struct)))
-                        return -1;
-        }
-        return 1;
-}
-
-/*
- * This restores directly out of user space. Exceptions are handled.
- */
-static inline int restore_i387(struct _fpstate __user *buf)
-{
-        struct task_struct *tsk = current;
-        int err;
-
-        if (!used_math()) {
-                err = init_fpu(tsk);
-                if (err)
-                        return err;
-        }
-
-        if (!(task_thread_info(current)->status & TS_USEDFPU)) {
-                clts();
-                task_thread_info(current)->status |= TS_USEDFPU;
-        }
-        err = restore_fpu_checking((__force struct i387_fxsave_struct *)buf);
-        if (unlikely(err)) {
-                /*
-                 * Encountered an error while doing the restore from the
-                 * user buffer, clear the fpu state.
-                 */
-                clear_fpu(tsk);
-                clear_used_math();
-        }
-        return err;
-}
-
-/*
  * Do a signal return; undo the signal stack.
  */
 static int
@@ -160,25 +97,11 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
         {
                 struct _fpstate __user * buf;
                 err |= __get_user(buf, &sc->fpstate);
-
-                if (buf) {
-                        if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))
-                                goto badframe;
-                        err |= restore_i387(buf);
-                } else {
-                        struct task_struct *me = current;
-                        if (used_math()) {
-                                clear_fpu(me);
-                                clear_used_math();
-                        }
-                }
+                err |= restore_i387_xstate(buf);
         }
 
         err |= __get_user(*pax, &sc->ax);
         return err;
-
-badframe:
-        return 1;
 }
 
 asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
@@ -276,7 +199,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                            sigset_t *set, struct pt_regs * regs)
 {
         struct rt_sigframe __user *frame;
-        struct _fpstate __user *fp = NULL; 
+        void __user *fp = NULL;
         int err = 0;
         struct task_struct *me = current;
 
@@ -288,7 +211,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
                 if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
                         goto give_sigsegv;
 
-                if (save_i387(fp) < 0) 
+                if (save_i387_xstate(fp) < 0)
                         err |= -1; 
         } else
                 frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;