7 files changed, 15 insertions, 79 deletions

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a902a5c1c76a..951a517a1a0f 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -144,6 +144,8 @@ config PPC
         select GENERIC_KERNEL_THREAD
         select HAVE_MOD_ARCH_SPECIFIC
         select MODULES_USE_ELF_RELA
+        select GENERIC_KERNEL_EXECVE
+        select CLONE_BACKWARDS
 
 config EARLY_PRINTK
         bool
diff --git a/arch/powerpc/include/asm/signal.h b/arch/powerpc/include/asm/signal.h
index 189998bb61c4..a101637725a2 100644
--- a/arch/powerpc/include/asm/signal.h
+++ b/arch/powerpc/include/asm/signal.h
@@ -3,6 +3,4 @@
 
 #include <uapi/asm/signal.h>
 
-struct pt_regs;
-#define ptrace_signal_deliver(regs, cookie) do { } while (0)
 #endif /* _ASM_POWERPC_SIGNAL_H */
diff --git a/arch/powerpc/include/asm/syscalls.h b/arch/powerpc/include/asm/syscalls.h
index 329db4ec12ca..b5308d3e6d39 100644
--- a/arch/powerpc/include/asm/syscalls.h
+++ b/arch/powerpc/include/asm/syscalls.h
@@ -17,15 +17,6 @@ asmlinkage unsigned long sys_mmap(unsigned long addr, size_t len,
 asmlinkage unsigned long sys_mmap2(unsigned long addr, size_t len,
                 unsigned long prot, unsigned long flags,
                 unsigned long fd, unsigned long pgoff);
-asmlinkage int sys_clone(unsigned long clone_flags, unsigned long usp,
-                int __user *parent_tidp, void __user *child_threadptr,
-                int __user *child_tidp, int p6, struct pt_regs *regs);
-asmlinkage int sys_fork(unsigned long p1, unsigned long p2,
-                unsigned long p3, unsigned long p4, unsigned long p5,
-                unsigned long p6, struct pt_regs *regs);
-asmlinkage int sys_vfork(unsigned long p1, unsigned long p2,
-                unsigned long p3, unsigned long p4, unsigned long p5,
-                unsigned long p6, struct pt_regs *regs);
 asmlinkage long sys_pipe(int __user *fildes);
 asmlinkage long sys_pipe2(int __user *fildes, int flags);
 asmlinkage long sys_rt_sigaction(int sig,
diff --git a/arch/powerpc/include/asm/unistd.h b/arch/powerpc/include/asm/unistd.h
index 921dce6d8445..76fe846ec40e 100644
--- a/arch/powerpc/include/asm/unistd.h
+++ b/arch/powerpc/include/asm/unistd.h
@@ -56,7 +56,9 @@
 #define __ARCH_WANT_COMPAT_SYS_SENDFILE
 #endif
 #define __ARCH_WANT_SYS_EXECVE
-#define __ARCH_WANT_KERNEL_EXECVE
+#define __ARCH_WANT_SYS_FORK
+#define __ARCH_WANT_SYS_VFORK
+#define __ARCH_WANT_SYS_CLONE
 
 /*
  * "Conditional" syscalls
diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S
index 9499385676e7..d22e73e4618b 100644
--- a/arch/powerpc/kernel/entry_32.S
+++ b/arch/powerpc/kernel/entry_32.S
@@ -444,11 +444,6 @@ ret_from_kernel_thread:
         PPC440EP_ERR42
         blrl
         li      r3,0
-        b       do_exit         # no return
-
-        .globl  __ret_from_kernel_execve
-__ret_from_kernel_execve:
-        addi    r1,r3,-STACK_FRAME_OVERHEAD
         b       ret_from_syscall
 
 /* Traced system call support */
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 56e0ff0878b5..e9a906c27234 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -373,17 +373,11 @@ _GLOBAL(ret_from_fork)
 _GLOBAL(ret_from_kernel_thread)
         bl      .schedule_tail
         REST_NVGPRS(r1)
-        REST_GPR(2,r1)
+        ld      r14, 0(r14)
         mtlr    r14
         mr      r3,r15
         blrl
         li      r3,0
-        b       .do_exit        # no return
-
-_GLOBAL(__ret_from_kernel_execve)
-        addi    r1,r3,-STACK_FRAME_OVERHEAD
-        li      r10,1
-        std     r10,SOFTE(r1)
         b       syscall_exit
 
         .section        ".toc","aw"
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ba48233500f6..81430674e71c 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -733,8 +733,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */
 
 int copy_thread(unsigned long clone_flags, unsigned long usp,
-                unsigned long arg, struct task_struct *p,
-                struct pt_regs *regs)
+                unsigned long arg, struct task_struct *p)
 {
         struct pt_regs *childregs, *kregs;
         extern void ret_from_fork(void);
@@ -745,25 +744,25 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
         /* Copy registers */
         sp -= sizeof(struct pt_regs);
         childregs = (struct pt_regs *) sp;
-        if (!regs) {
-                /* for kernel thread, set `current' and stackptr in new task */
+        if (unlikely(p->flags & PF_KTHREAD)) {
+                struct thread_info *ti = (void *)task_stack_page(p);
                 memset(childregs, 0, sizeof(struct pt_regs));
                 childregs->gpr[1] = sp + sizeof(struct pt_regs);
+                childregs->gpr[14] = usp;       /* function */
 #ifdef CONFIG_PPC64
-                childregs->gpr[14] = *(unsigned long *)usp;
-                childregs->gpr[2] = ((unsigned long *)usp)[1],
                 clear_tsk_thread_flag(p, TIF_32BIT);
-#else
-                childregs->gpr[14] = usp;       /* function */
-                childregs->gpr[2] = (unsigned long) p;
+                childregs->softe = 1;
 #endif
                 childregs->gpr[15] = arg;
                 p->thread.regs = NULL;  /* no user register state */
+                ti->flags |= _TIF_RESTOREALL;
                 f = ret_from_kernel_thread;
         } else {
+                struct pt_regs *regs = current_pt_regs();
                 CHECK_FULL_REGS(regs);
                 *childregs = *regs;
-                childregs->gpr[1] = usp;
+                if (usp)
+                        childregs->gpr[1] = usp;
                 p->thread.regs = childregs;
                 childregs->gpr[3] = 0;  /* Result from fork() */
                 if (clone_flags & CLONE_SETTLS) {
@@ -1027,51 +1026,6 @@ int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
         return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
 }
 
-#define TRUNC_PTR(x)    ((typeof(x))(((unsigned long)(x)) & 0xffffffff))
-
-int sys_clone(unsigned long clone_flags, unsigned long usp,
-              int __user *parent_tidp, void __user *child_threadptr,
-              int __user *child_tidp, int p6,
-              struct pt_regs *regs)
-{
-        CHECK_FULL_REGS(regs);
-        if (usp == 0)
-                usp = regs->gpr[1];     /* stack pointer for child */
-#ifdef CONFIG_PPC64
-        if (is_32bit_task()) {
-                parent_tidp = TRUNC_PTR(parent_tidp);
-                child_tidp = TRUNC_PTR(child_tidp);
-        }
-#endif
-        return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
-}
-
-int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
-             unsigned long p4, unsigned long p5, unsigned long p6,
-             struct pt_regs *regs)
-{
-        CHECK_FULL_REGS(regs);
-        return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
-}
-
-int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
-              unsigned long p4, unsigned long p5, unsigned long p6,
-              struct pt_regs *regs)
-{
-        CHECK_FULL_REGS(regs);
-        return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
-                        regs, 0, NULL, NULL);
-}
-
-void __ret_from_kernel_execve(struct pt_regs *normal)
-__noreturn;
-
-void ret_from_kernel_execve(struct pt_regs *normal)
-{
-        set_thread_flag(TIF_RESTOREALL);
-        __ret_from_kernel_execve(normal);
-}
-
 static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
                                   unsigned long nbytes)
 {