x86: signal: move macros out from restore_sigcontext()

move macros, COPY, COPY_SEG*, GET_SEG, out from restore_sigcontext().
x86_64: introduce COPY_SEG_STRICT for cs.

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

1 files changed, 11 insertions, 7 deletions

diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index 53f86d95985b..feff4a91d095 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -52,6 +52,16 @@ sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
         return do_sigaltstack(uss, uoss, regs->sp);
 }
 
+#define COPY(x)                 {               \
+        err |= __get_user(regs->x, &sc->x);     \
+}
+
+#define COPY_SEG_STRICT(seg)    {                       \
+                unsigned short tmp;                     \
+                err |= __get_user(tmp, &sc->seg);       \
+                regs->seg = tmp | 3;                    \
+}
+
 /*
  * Do a signal return; undo the signal stack.
  */
@@ -64,8 +74,6 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
         /* Always make any pending restarted system calls return -EINTR */
         current_thread_info()->restart_block.fn = do_no_restart_syscall;
 
-#define COPY(x)         (err |= __get_user(regs->x, &sc->x))
-
         COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
         COPY(dx); COPY(cx); COPY(ip);
         COPY(r8);
@@ -80,11 +88,7 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
         /* Kernel saves and restores only the CS segment register on signals,
          * which is the bare minimum needed to allow mixed 32/64-bit code.
          * App's signal handler can save/restore other segments if needed. */
-        {
-                unsigned cs;
-                err |= __get_user(cs, &sc->cs);
-                regs->cs = cs | 3;      /* Force into user mode */
-        }
+        COPY_SEG_STRICT(cs);
 
         {
                 unsigned int tmpflags;