[S390] System call cleanup.

Remove system call glue for sys_clone, sys_fork, sys_vfork, sys_execve,
sys_sigreturn, sys_rt_sigreturn and sys_sigaltstack. Call do_execve from
kernel_execve directly, move pt_regs to the right place and branch to
sysc_return to start the user space program. This removes the last
in-kernel system call.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index 554f9cf7499c..3c41907799a1 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -102,9 +102,9 @@ sys_sigaction(int sig, const struct old_sigaction __user *act,
 }
 
 asmlinkage long
-sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
-                                        struct pt_regs *regs)
+sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss)
 {
+        struct pt_regs *regs = task_pt_regs(current);
         return do_sigaltstack(uss, uoss, regs->gprs[15]);
 }
 
@@ -163,8 +163,9 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
         return 0;
 }
 
-asmlinkage long sys_sigreturn(struct pt_regs *regs)
+asmlinkage long sys_sigreturn(void)
 {
+        struct pt_regs *regs = task_pt_regs(current);
         sigframe __user *frame = (sigframe __user *)regs->gprs[15];
         sigset_t set;
 
@@ -189,8 +190,9 @@ badframe:
         return 0;
 }
 
-asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+asmlinkage long sys_rt_sigreturn(void)
 {
+        struct pt_regs *regs = task_pt_regs(current);
         rt_sigframe __user *frame = (rt_sigframe __user *)regs->gprs[15];
         sigset_t set;