score: switch to generic sigaltstack

Signed-off-by: Al Viro <[e-mail]>

arch/score/Kconfig

···
        select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_REL
 	select CLONE_BACKWARDS
+	select GENERIC_SIGALTSTACK
 
 choice
 	prompt "System type"

arch/score/include/asm/syscalls.h

···
 #ifndef _ASM_SCORE_SYSCALLS_H
 #define _ASM_SCORE_SYSCALLS_H
 
-asmlinkage long score_sigaltstack(struct pt_regs *regs);
 asmlinkage long score_rt_sigreturn(struct pt_regs *regs);
 
 #include <asm-generic/syscalls.h>

arch/score/kernel/entry.S

···
 	mv	r4, r0
 	la	r8, score_rt_sigreturn
 	br	r8
-
-ENTRY(sys_sigaltstack)
-	mv	r4, r0
-	la	r8, score_sigaltstack
-	br	r8

arch/score/kernel/signal.c

···
 }
 
 asmlinkage long
-score_sigaltstack(struct pt_regs *regs)
-{
-	const stack_t __user *uss = (const stack_t __user *) regs->regs[4];
-	stack_t __user *uoss = (stack_t __user *) regs->regs[5];
-	unsigned long usp = regs->regs[0];
-
-	return do_sigaltstack(uss, uoss, usp);
-}
-
-asmlinkage long
 score_rt_sigreturn(struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame;
···
 	else if (sig)
 		force_sig(sig, current);
 
-	/* It is more difficult to avoid calling this function than to
-	   call it and ignore errors.  */
-	if (do_sigaltstack(&frame->rs_uc.uc_stack, NULL, regs->regs[0]) == -EFAULT)
+	if (restore_altstack(&frame->rs_uc.uc_stack))
 		goto badframe;
 	regs->is_syscall = 0;
 
···
 	err |= copy_siginfo_to_user(&frame->rs_info, info);
 	err |= __put_user(0, &frame->rs_uc.uc_flags);
 	err |= __put_user(NULL, &frame->rs_uc.uc_link);
-	err |= __put_user((void __user *)current->sas_ss_sp,
-				&frame->rs_uc.uc_stack.ss_sp);
-	err |= __put_user(sas_ss_flags(regs->regs[0]),
-				&frame->rs_uc.uc_stack.ss_flags);
-	err |= __put_user(current->sas_ss_size,
-				&frame->rs_uc.uc_stack.ss_size);
+	err |= __save_altstack(&frame->rs_uc.uc_stack, regs->regs[0]);
 	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
 	err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));