}
/*
- * "m68k_fork()".. By the time we get here, the
- * non-volatile registers have also been saved on the
- * stack. We do some ugly pointer stuff here.. (see
- * also copy_thread)
+ * Why not generic sys_clone, you ask? m68k passes all arguments on stack.
+ * And we need all registers saved, which means a bunch of stuff pushed
+ * on top of pt_regs, which means that sys_clone() arguments would be
+ * buried. We could, of course, copy them, but it's too costly for no
+ * good reason - generic clone() would have to copy them *again* for
+ * do_fork() anyway. So in this case it's actually better to pass pt_regs *
+ * and extract arguments for do_fork() from there. Eventually we might
+ * go for calling do_fork() directly from the wrapper, but only after we
+ * are finished with do_fork() prototype conversion.
*/
-
-asmlinkage int m68k_fork(struct pt_regs *regs)
-{
-#ifdef CONFIG_MMU
- return do_fork(SIGCHLD, rdusp(), regs, 0, NULL, NULL);
-#else
- return -EINVAL;
-#endif
-}
-
-asmlinkage int m68k_vfork(struct pt_regs *regs)
-{
- return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, rdusp(), regs, 0,
- NULL, NULL);
-}
-
asmlinkage int m68k_clone(struct pt_regs *regs)
{
- unsigned long clone_flags;
- unsigned long newsp;
- int __user *parent_tidptr, *child_tidptr;
-
- /* syscall2 puts clone_flags in d1 and usp in d2 */
- clone_flags = regs->d1;
- newsp = regs->d2;
- parent_tidptr = (int __user *)regs->d3;
- child_tidptr = (int __user *)regs->d4;
- if (!newsp)
- newsp = rdusp();
- return do_fork(clone_flags, newsp, regs, 0,
- parent_tidptr, child_tidptr);
+ /* regs will be equal to current_pt_regs() */
+ return do_fork(regs->d1, regs->d2, regs, 0,
+ (int __user *)regs->d3, (int __user *)regs->d4);
}
int copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long arg,
- struct task_struct * p, struct pt_regs * regs)
+ struct task_struct * p, struct pt_regs * unused)
{
- struct pt_regs * childregs;
- struct switch_stack *childstack;
+ struct fork_frame {
+ struct switch_stack sw;
+ struct pt_regs regs;
+ } *frame;
- childregs = (struct pt_regs *) (task_stack_page(p) + THREAD_SIZE) - 1;
- childstack = ((struct switch_stack *) childregs) - 1;
+ frame = (struct fork_frame *) (task_stack_page(p) + THREAD_SIZE) - 1;
- p->thread.usp = usp;
- p->thread.ksp = (unsigned long)childstack;
- p->thread.esp0 = (unsigned long)childregs;
+ p->thread.ksp = (unsigned long)frame;
+ p->thread.esp0 = (unsigned long)&frame->regs;
/*
* Must save the current SFC/DFC value, NOT the value when
*/
p->thread.fs = get_fs().seg;
- if (unlikely(!regs)) {
+ if (unlikely(p->flags & PF_KTHREAD)) {
/* kernel thread */
- memset(childstack, 0,
- sizeof(struct switch_stack) + sizeof(struct pt_regs));
- childregs->sr = PS_S;
- childstack->a3 = usp; /* function */
- childstack->d7 = arg;
- childstack->retpc = (unsigned long)ret_from_kernel_thread;
+ memset(frame, 0, sizeof(struct fork_frame));
+ frame->regs.sr = PS_S;
+ frame->sw.a3 = usp; /* function */
+ frame->sw.d7 = arg;
+ frame->sw.retpc = (unsigned long)ret_from_kernel_thread;
p->thread.usp = 0;
return 0;
}
- *childregs = *regs;
- childregs->d0 = 0;
-
- *childstack = ((struct switch_stack *) regs)[-1];
- childstack->retpc = (unsigned long)ret_from_fork;
+ memcpy(frame, container_of(current_pt_regs(), struct fork_frame, regs),
+ sizeof(struct fork_frame));
+ frame->regs.d0 = 0;
+ frame->sw.retpc = (unsigned long)ret_from_fork;
+ p->thread.usp = usp ?: rdusp();
if (clone_flags & CLONE_SETTLS)
- task_thread_info(p)->tp_value = regs->d5;
+ task_thread_info(p)->tp_value = frame->regs.d5;
#ifdef CONFIG_FPU
if (!FPU_IS_EMU) {
projects / profile / ivi / kernel-adaptation-intel-automotive.git / commitdiff