x86: split ret_from_fork
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 75fcad1..c993987 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -57,6 +57,7 @@
#include <asm/switch_to.h>
asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+asmlinkage void ret_from_kernel_thread(void) __asm__("ret_from_kernel_thread");
/*
* Return saved PC of a blocked thread.
@@ -127,23 +128,39 @@
}
int copy_thread(unsigned long clone_flags, unsigned long sp,
- unsigned long unused,
+ unsigned long arg,
struct task_struct *p, struct pt_regs *regs)
{
- struct pt_regs *childregs;
+ struct pt_regs *childregs = task_pt_regs(p);
struct task_struct *tsk;
int err;
- childregs = task_pt_regs(p);
- *childregs = *regs;
- childregs->ax = 0;
- childregs->sp = sp;
-
p->thread.sp = (unsigned long) childregs;
p->thread.sp0 = (unsigned long) (childregs+1);
- p->thread.ip = (unsigned long) ret_from_fork;
+ if (unlikely(!regs)) {
+ /* kernel thread */
+ memset(childregs, 0, sizeof(struct pt_regs));
+ p->thread.ip = (unsigned long) ret_from_kernel_thread;
+ task_user_gs(p) = __KERNEL_STACK_CANARY;
+ childregs->ds = __USER_DS;
+ childregs->es = __USER_DS;
+ childregs->fs = __KERNEL_PERCPU;
+ 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;
+ p->fpu_counter = 0;
+ p->thread.io_bitmap_ptr = NULL;
+ memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));
+ return 0;
+ }
+ *childregs = *regs;
+ childregs->ax = 0;
+ childregs->sp = sp;
+ p->thread.ip = (unsigned long) ret_from_fork;
task_user_gs(p) = get_user_gs(regs);
p->fpu_counter = 0;