x86: signal: intrroduce get_sigframe() and replace get_sigstack()

Impact: cleanup

Introduce get_sigframe() like 32-bit to replace get_sigstack().
Move the i387 stuff into get_sigframe().

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 19 insertions, 13 deletions

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index e89eaf417e55..82d37c77b0fb 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -392,10 +392,13 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
  * Determine which stack to use..
  */
 static void __user *
-get_stack(struct k_sigaction *ka, unsigned long sp, unsigned long size)
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
+             void __user **fpstate)
 {
-        /* Default to using normal stack - redzone*/
-        sp -= 128;
+        unsigned long sp;
+
+        /* Default to using normal stack - redzone */
+        sp = regs->sp - 128;
 
         /* This is the X/Open sanctioned signal stack switching.  */
         if (ka->sa.sa_flags & SA_ONSTACK) {
@@ -403,7 +406,18 @@ get_stack(struct k_sigaction *ka, unsigned long sp, unsigned long size)
                         sp = current->sas_ss_sp + current->sas_ss_size;
         }
 
-        return (void __user *)round_down(sp - size, 64);
+        if (used_math()) {
+                sp -= sig_xstate_size;
+                *fpstate = (void __user *)round_down(sp, 64);
+                if (save_i387_xstate(*fpstate) < 0)
+                        return (void __user *) -1L;
+
+                sp -= frame_size;
+                return (void __user *)round_down(sp, 16) - 8;
+        }
+
+        sp -= frame_size;
+        return (void __user *)round_down(sp, 64) - 8;
 }
 
 static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
@@ -414,15 +428,7 @@ static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
         int err = 0;
         struct task_struct *me = current;
 
-        if (used_math()) {
-                fp = get_stack(ka, regs->sp, sig_xstate_size);
-                frame = (void __user *)round_down(
-                        (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
-
-                if (save_i387_xstate(fp) < 0)
-                        return -EFAULT;
-        } else
-                frame = get_stack(ka, regs->sp, sizeof(struct rt_sigframe)) - 8;
+        frame = get_sigframe(ka, regs, sizeof(struct rt_sigframe), &fp);
 
         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
                 return -EFAULT;