x86: split ret_from_fork
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 0a980c9..937f2af 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -146,29 +146,18 @@
}
int copy_thread(unsigned long clone_flags, unsigned long sp,
- unsigned long unused,
+ unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
int err;
struct pt_regs *childregs;
struct task_struct *me = current;
- childregs = ((struct pt_regs *)
- (THREAD_SIZE + task_stack_page(p))) - 1;
- *childregs = *regs;
-
- childregs->ax = 0;
- if (user_mode(regs))
- childregs->sp = sp;
- else
- childregs->sp = (unsigned long)childregs;
-
+ p->thread.sp0 = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+ childregs = task_pt_regs(p);
p->thread.sp = (unsigned long) childregs;
- p->thread.sp0 = (unsigned long) (childregs+1);
p->thread.usersp = me->thread.usersp;
-
set_tsk_thread_flag(p, TIF_FORK);
-
p->fpu_counter = 0;
p->thread.io_bitmap_ptr = NULL;
@@ -178,6 +167,24 @@
p->thread.fs = p->thread.fsindex ? 0 : me->thread.fs;
savesegment(es, p->thread.es);
savesegment(ds, p->thread.ds);
+ memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
+
+ if (unlikely(!regs)) {
+ /* kernel thread */
+ memset(childregs, 0, sizeof(struct pt_regs));
+ childregs->sp = (unsigned long)childregs;
+ childregs->ss = __KERNEL_DS;
+ childregs->bx = sp; /* function */
+ childregs->bp = arg;
+ childregs->orig_ax = -1;
+ childregs->cs = __KERNEL_CS | get_kernel_rpl();
+ childregs->flags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
+ return 0;
+ }
+ *childregs = *regs;
+
+ childregs->ax = 0;
+ childregs->sp = sp;
err = -ENOMEM;
memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));