[S390] cleanup trap handling

Move the program interruption code and the translation exception identifier
to the pt_regs structure as 'int_code' and 'int_parm_long' and make the
first level interrupt handler in entry[64].S store the two values. That
makes it possible to drop 'prot_addr' and 'trap_no' from the thread_struct
and to reduce the number of arguments to a lot of functions. Finally
un-inline do_trap. Overall this saves 5812 bytes in the .text section of
the 64 bit kernel.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 12 insertions, 8 deletions

diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index 7f6f9f354545..a8ba840294ff 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -302,9 +302,13 @@ static int setup_frame(int sig, struct k_sigaction *ka,
 
         /* We forgot to include these in the sigcontext.
            To avoid breaking binary compatibility, they are passed as args. */
-        regs->gprs[4] = current->thread.trap_no;
-        regs->gprs[5] = current->thread.prot_addr;
-        regs->gprs[6] = task_thread_info(current)->last_break;
+        if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
+            sig == SIGTRAP || sig == SIGFPE) {
+                /* set extra registers only for synchronous signals */
+                regs->gprs[4] = regs->int_code & 127;
+                regs->gprs[5] = regs->int_parm_long;
+                regs->gprs[6] = task_thread_info(current)->last_break;
+        }
 
         /* Place signal number on stack to allow backtrace from handler.  */
         if (__put_user(regs->gprs[2], (int __user *) &frame->signo))
@@ -434,13 +438,13 @@ void do_signal(struct pt_regs *regs)
          * call information.
          */
         current_thread_info()->system_call =
-                test_thread_flag(TIF_SYSCALL) ? regs->svc_code : 0;
+                test_thread_flag(TIF_SYSCALL) ? regs->int_code : 0;
         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
 
         if (signr > 0) {
                 /* Whee!  Actually deliver the signal.  */
                 if (current_thread_info()->system_call) {
-                        regs->svc_code = current_thread_info()->system_call;
+                        regs->int_code = current_thread_info()->system_call;
                         /* Check for system call restarting. */
                         switch (regs->gprs[2]) {
                         case -ERESTART_RESTARTBLOCK:
@@ -457,7 +461,7 @@ void do_signal(struct pt_regs *regs)
                                 regs->gprs[2] = regs->orig_gpr2;
                                 regs->psw.addr =
                                         __rewind_psw(regs->psw,
-                                                     regs->svc_code >> 16);
+                                                     regs->int_code >> 16);
                                 break;
                         }
                 }
@@ -488,11 +492,11 @@ void do_signal(struct pt_regs *regs)
         /* No handlers present - check for system call restart */
         clear_thread_flag(TIF_SYSCALL);
         if (current_thread_info()->system_call) {
-                regs->svc_code = current_thread_info()->system_call;
+                regs->int_code = current_thread_info()->system_call;
                 switch (regs->gprs[2]) {
                 case -ERESTART_RESTARTBLOCK:
                         /* Restart with sys_restart_syscall */
-                        regs->svc_code = __NR_restart_syscall;
+                        regs->int_code = __NR_restart_syscall;
                 /* fallthrough */
                 case -ERESTARTNOHAND:
                 case -ERESTARTSYS: