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>

diff --git a/arch/Kconfig b/arch/Kconfig
index 366ec06..8d698fb 100644 (file)
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -341,4 +341,18 @@ config MODULES_USE_ELF_REL
          Modules only use ELF REL relocations.  Modules with ELF RELA
          relocations will give an error.
 
+#
+# ABI hall of shame
+#
+config CLONE_BACKWARDS
+       bool
+       help
+         Architecture has tls passed as the 4th argument of clone(2),
+         not the 5th one.
+
+config CLONE_BACKWARDS2
+       bool
+       help
+         Architecture has the first two arguments of clone(2) swapped.
+
 source "kernel/gcov/Kconfig"

diff --git a/include/asm-generic/syscalls.h b/include/asm-generic/syscalls.h
index d89dec8..7e4fdb6 100644 (file)
--- a/include/asm-generic/syscalls.h
+++ b/include/asm-generic/syscalls.h
@@ -10,16 +10,15 @@
  */
 #ifndef sys_clone
 asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp,
-                       void __user *parent_tid, void __user *child_tid,
-                       struct pt_regs *regs);
+                       void __user *parent_tid, void __user *child_tid);
 #endif
 
 #ifndef sys_fork
-asmlinkage long sys_fork(struct pt_regs *regs);
+asmlinkage long sys_fork(void);
 #endif
 
 #ifndef sys_vfork
-asmlinkage long sys_vfork(struct pt_regs *regs);
+asmlinkage long sys_vfork(void);
 #endif
 
 #ifndef sys_execve

diff --git a/kernel/fork.c b/kernel/fork.c
index 8b20ab7..27a3375 100644 (file)
--- 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