score: switch to generic fork/vfork/clone

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/score/Kconfig

@@ -15,6 +15,7 @@ config SCORE
 	select MODULES_USE_ELF_REL
 	select GENERIC_KERNEL_THREAD
 	select GENERIC_KERNEL_EXECVE
+	select CLONE_BACKWARDS
 
 choice
 	prompt "System type"

arch/score/include/asm/syscalls.h

 #ifndef _ASM_SCORE_SYSCALLS_H
 #define _ASM_SCORE_SYSCALLS_H
 
-asmlinkage long score_clone(struct pt_regs *regs);
 asmlinkage long score_sigaltstack(struct pt_regs *regs);
 asmlinkage long score_rt_sigreturn(struct pt_regs *regs);
 

arch/score/include/asm/unistd.h

@@ -5,5 +5,8 @@
 #define __ARCH_WANT_SYSCALL_OFF_T
 #define __ARCH_WANT_SYSCALL_DEPRECATED
 #define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_SYS_CLONE
+#define __ARCH_WANT_SYS_FORK
+#define __ARCH_WANT_SYS_VFORK
 
 #include <asm-generic/unistd.h>

arch/score/kernel/entry.S

@@ -487,11 +487,6 @@ illegal_syscall:
 	sw	r9, [r0, PT_R7]
 	j	syscall_return
 
-ENTRY(sys_clone)
-	mv	r4, r0
-	la	r8, score_clone
-	br	r8
-
 ENTRY(sys_rt_sigreturn)
 	mv	r4, r0
 	la	r8, score_rt_sigreturn
@@ -501,16 +496,3 @@ ENTRY(sys_sigaltstack)
 	mv	r4, r0
 	la	r8, score_sigaltstack
 	br	r8
-
-#ifdef __ARCH_WANT_SYSCALL_DEPRECATED
-ENTRY(sys_fork)
-	mv	r4, r0
-	la	r8, score_fork
-	br	r8
-
-ENTRY(sys_vfork)
-	mv	r4, r0
-	la	r8, score_vfork
-	br	r8
-#endif /* __ARCH_WANT_SYSCALL_DEPRECATED */
-

arch/score/kernel/process.c

@@ -94,17 +94,17 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 	struct pt_regs *childregs = task_pt_regs(p);
 
 	p->thread.reg0 = (unsigned long) childregs;
-	if (unlikely(!regs)) {
+	if (unlikely(p->flags & PF_KTHREAD)) {
 		memset(childregs, 0, sizeof(struct pt_regs));
 		p->thread->reg12 = usp;
 		p->thread->reg13 = arg;
 		p->thread.reg3 = (unsigned long) ret_from_kernel_thread;
 	} else {
-		*childregs = *regs;
+		*childregs = *current_pt_regs();
 		childregs->regs[7] = 0;		/* Clear error flag */
 		childregs->regs[4] = 0;		/* Child gets zero as return value */
-		childregs->regs[0] = usp;	/* user fork */
-		regs->regs[4] = p->pid;		/* WTF? */
+		if (usp)
+			childregs->regs[0] = usp;	/* user fork */
 		p->thread.reg3 = (unsigned long) ret_from_fork;
 	}
 

arch/score/kernel/sys_score.c

@@ -48,38 +48,3 @@ sys_mmap(unsigned long addr, unsigned long len, unsigned long prot,
 		return -EINVAL;
 	return sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
 }
-
-asmlinkage long
-score_fork(struct pt_regs *regs)
-{
-	return do_fork(SIGCHLD, regs->regs[0], regs, 0, NULL, NULL);
-}
-
-/*
- * Clone a task - this clones the calling program thread.
- * This is called indirectly via a small wrapper
- */
-asmlinkage long
-score_clone(struct pt_regs *regs)
-{
-	unsigned long clone_flags;
-	unsigned long newsp;
-	int __user *parent_tidptr, *child_tidptr;
-
-	clone_flags = regs->regs[4];
-	newsp = regs->regs[5];
-	if (!newsp)
-		newsp = regs->regs[0];
-	parent_tidptr = (int __user *)regs->regs[6];
-	child_tidptr = (int __user *)regs->regs[8];
-
-	return do_fork(clone_flags, newsp, regs, 0,
-			parent_tidptr, child_tidptr);
-}
-
-asmlinkage long
-score_vfork(struct pt_regs *regs)
-{
-	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD,
-			regs->regs[0], regs, 0, NULL, NULL);
-}