generic sys_fork / sys_vfork / sys_clone

... and get rid of idiotic struct pt_regs * in asm-generic/syscalls.h
prototypes of the same, while we are at it.  Eventually we want those
in linux/syscalls.h, of course, but that'll have to wait a bit.

Note that there are *three* variants of sys_clone() order of arguments.
Braindamage galore...

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

1 files changed, 43 insertions, 0 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 8b20ab7d3aa2..27a337549dab 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1645,6 +1645,49 @@ pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
 }
 #endif
 
+#ifdef __ARCH_WANT_SYS_FORK
+SYSCALL_DEFINE0(fork)
+{
+#ifdef CONFIG_MMU
+        return do_fork(SIGCHLD, 0, current_pt_regs(), 0, NULL, NULL);
+#else
+        /* can not support in nommu mode */
+        return(-EINVAL);
+#endif
+}
+#endif
+
+#ifdef __ARCH_WANT_SYS_VFORK
+SYSCALL_DEFINE0(vfork)
+{
+        return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, 0, current_pt_regs(),
+                        0, NULL, NULL);
+}
+#endif
+
+#ifdef __ARCH_WANT_SYS_CLONE
+#ifdef CONFIG_CLONE_BACKWARDS
+SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
+                 int __user *, parent_tidptr,
+                 int, tls_val,
+                 int __user *, child_tidptr)
+#elif defined(CONFIG_CLONE_BACKWARDS2)
+SYSCALL_DEFINE5(clone, unsigned long, newsp, unsigned long, clone_flags,
+                 int __user *, parent_tidptr,
+                 int __user *, child_tidptr,
+                 int, tls_val)
+#else
+SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
+                 int __user *, parent_tidptr,
+                 int __user *, child_tidptr,
+                 int, tls_val)
+#endif
+{
+        return do_fork(clone_flags, newsp, current_pt_regs(), 0,
+                parent_tidptr, child_tidptr);
+}
+#endif
+
 #ifndef ARCH_MIN_MMSTRUCT_ALIGN
 #define ARCH_MIN_MMSTRUCT_ALIGN 0
 #endif