diff options
Diffstat (limited to 'arch/m68k/kernel/process.c')
| -rw-r--r-- | arch/m68k/kernel/process.c | 87 |
1 files changed, 32 insertions, 55 deletions
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c index c51bb172e14..d538694ad20 100644 --- a/arch/m68k/kernel/process.c +++ b/arch/m68k/kernel/process.c @@ -136,57 +136,35 @@ void flush_thread(void) } /* - * "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, 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) + unsigned long arg, struct task_struct *p) { - 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 @@ -194,25 +172,24 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, */ 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) { |