arm: switch to generic fork/vfork/clone

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

6 files changed, 13 insertions, 55 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ade7e924bef5..8918a2dd89b4 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -55,6 +55,7 @@ config ARM
         select SYS_SUPPORTS_APM_EMULATION
         select HAVE_MOD_ARCH_SPECIFIC if ARM_UNWIND
         select MODULES_USE_ELF_REL
+        select CLONE_BACKWARDS
         help
           The ARM series is a line of low-power-consumption RISC chip designs
           licensed by ARM Ltd and targeted at embedded applications and
diff --git a/arch/arm/include/asm/unistd.h b/arch/arm/include/asm/unistd.h
index 8f60b6e6bd41..7cd13cc62624 100644
--- a/arch/arm/include/asm/unistd.h
+++ b/arch/arm/include/asm/unistd.h
@@ -42,6 +42,9 @@
 #define __ARCH_WANT_SYS_SOCKETCALL
 #endif
 #define __ARCH_WANT_SYS_EXECVE
+#define __ARCH_WANT_SYS_FORK
+#define __ARCH_WANT_SYS_VFORK
+#define __ARCH_WANT_SYS_CLONE
 
 /*
  * "Conditional" syscalls
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index 831cd38c8d99..5935b6a02e6e 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -11,7 +11,7 @@
  */
 /* 0 */         CALL(sys_restart_syscall)
                 CALL(sys_exit)
-                CALL(sys_fork_wrapper)
+                CALL(sys_fork)
                 CALL(sys_read)
                 CALL(sys_write)
 /* 5 */         CALL(sys_open)
@@ -129,7 +129,7 @@
                 CALL(OBSOLETE(ABI(sys_ipc, sys_oabi_ipc)))
                 CALL(sys_fsync)
                 CALL(sys_sigreturn_wrapper)
-/* 120 */       CALL(sys_clone_wrapper)
+/* 120 */       CALL(sys_clone)
                 CALL(sys_setdomainname)
                 CALL(sys_newuname)
                 CALL(sys_ni_syscall)            /* modify_ldt */
@@ -199,7 +199,7 @@
                 CALL(sys_sendfile)
                 CALL(sys_ni_syscall)            /* getpmsg */
                 CALL(sys_ni_syscall)            /* putpmsg */
-/* 190 */       CALL(sys_vfork_wrapper)
+/* 190 */       CALL(sys_vfork)
                 CALL(sys_getrlimit)
                 CALL(sys_mmap2)
                 CALL(ABI(sys_truncate64, sys_oabi_truncate64))
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index 34711757ba59..88a07feaa05f 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -510,22 +510,6 @@ sys_syscall:
                 b       sys_ni_syscall
 ENDPROC(sys_syscall)
 
-sys_fork_wrapper:
-                add     r0, sp, #S_OFF
-                b       sys_fork
-ENDPROC(sys_fork_wrapper)
-
-sys_vfork_wrapper:
-                add     r0, sp, #S_OFF
-                b       sys_vfork
-ENDPROC(sys_vfork_wrapper)
-
-sys_clone_wrapper:
-                add     ip, sp, #S_OFF
-                str     ip, [sp, #4]
-                b       sys_clone
-ENDPROC(sys_clone_wrapper)
-
 sys_sigreturn_wrapper:
                 add     r0, sp, #S_OFF
                 mov     why, #0         @ prevent syscall restart handling
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 90084a6de35a..4ab80bbb6d95 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -376,17 +376,18 @@ asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
 int
 copy_thread(unsigned long clone_flags, unsigned long stack_start,
-            unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
+            unsigned long stk_sz, struct task_struct *p, struct pt_regs *unused)
 {
         struct thread_info *thread = task_thread_info(p);
         struct pt_regs *childregs = task_pt_regs(p);
 
         memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
 
-        if (likely(regs)) {
-                *childregs = *regs;
+        if (likely(!(p->flags & PF_KTHREAD))) {
+                *childregs = *current_pt_regs();
                 childregs->ARM_r0 = 0;
-                childregs->ARM_sp = stack_start;
+                if (stack_start)
+                        childregs->ARM_sp = stack_start;
         } else {
                 memset(childregs, 0, sizeof(struct pt_regs));
                 thread->cpu_context.r4 = stk_sz;
@@ -399,7 +400,7 @@ copy_thread(unsigned long clone_flags, unsigned long stack_start,
         clear_ptrace_hw_breakpoint(p);
 
         if (clone_flags & CLONE_SETTLS)
-                thread->tp_value = regs->ARM_r3;
+                thread->tp_value = childregs->ARM_r3;
 
         thread_notify(THREAD_NOTIFY_COPY, thread);
 
diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c
index c2a898aa57aa..3151f5623d0e 100644
--- a/arch/arm/kernel/sys_arm.c
+++ b/arch/arm/kernel/sys_arm.c
@@ -28,37 +28,6 @@
 #include <linux/uaccess.h>
 #include <linux/slab.h>
 
-/* Fork a new task - this creates a new program thread.
- * This is called indirectly via a small wrapper
- */
-asmlinkage int sys_fork(struct pt_regs *regs)
-{
-#ifdef CONFIG_MMU
-        return do_fork(SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
-#else
-        /* can not support in nommu mode */
-        return(-EINVAL);
-#endif
-}
-
-/* Clone a task - this clones the calling program thread.
- * This is called indirectly via a small wrapper
- */
-asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
-                         int __user *parent_tidptr, int tls_val,
-                         int __user *child_tidptr, struct pt_regs *regs)
-{
-        if (!newsp)
-                newsp = regs->ARM_sp;
-
-        return do_fork(clone_flags, newsp, regs, 0, parent_tidptr, child_tidptr);
-}
-
-asmlinkage int sys_vfork(struct pt_regs *regs)
-{
-        return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->ARM_sp, regs, 0, NULL, NULL);
-}
-
 /*
  * Since loff_t is a 64 bit type we avoid a lot of ABI hassle
  * with a different argument ordering.